text:
About Exercise Science
Skidmore is one of a very few liberal arts colleges that offers an exercise science major. Our courses and research emphasize an understanding of the effects of exercise on human function, health, and the physiological and biochemical mechanisms underlying responses to exercise—in other words, the "science of health." The major provides you with a foundation for advanced studies in fields such as exercise physiology, bioenergetics, nutrition, sports medicine, biomechanics, and kinesiology, as well as careers in medicine and allied health fields including physical therapy, chiropractic medicine, nursing, occupational therapy, and physician-assistant work. Many of our graduates go on to masters- and doctorate-degree programs, and report that their hands-on research experiences at Skidmore prepared them for success.
Interesting Classes I Might Take
- Introduction to Exercise Science
- Sports and Social Issues
- Human Anatomy and Physiology I & II
- Introduction to Public Health
- Exercise Testing and Prescription
- Principles of Nutrition for Health and Performance
- Research Design
Beyond the Classroom
Recent faculty-student research projects:
- Is the deleterious effect of a high-fat diet on vascular health mediated through vascular mitochondrial dysfunction?
- Succininc acid as a potential treatment for type-2 diabetes
- MnTBAP reduces adiposity and increases bio-markers for mitochondrial biogenesis
- Effects of dietary-induced obesity, exercise training, and aging on hepatic cide expression
Recent internships with…
- athletic trainer for pro hockey team, Adirondack Flames (Glens Falls, N.Y.)
- orthopedic surgeon with OrthoNY (Saratoga Springs, N.Y.)
- occupational therapist in a public school (Saratoga Springs, N.Y.)
- Clinton Foundation Global Initiative health team (NYC)
- Project Healthcare, Bellevue Hospital (NYC)
Popular study abroad progams: University of Queensland (Australia) and University of Auckland (New Zealand)
Recent senior theses:
- Acute effects of tobacco use on arterial stiffness and platelet function in users
- Effect of six sessions of barefoot running on the flexibility of the foot and ankle complex in respect to the risk factors of plantar fasciitis
- Comparison of two raw juices with a commercially available drink on athletic performance and post-recovery measures
- Effects of a high-protein, low-calorie, intermittent-fast diet on plasma toxins and oxidative stress following weight loss
Success After Skidmore
Careers: A sampler of what our alumni do
- Registered nurse:
-Albany Medical Center, Albany, N.Y.
-Central Vermont Medical Center
-North Shore-LIJ Health System, Bay Shore, N.Y.
-Thomas Jefferson University Hospital, Philadelphia, Pa.
-University of Pittsburgh Medical Center, Pittsburgh, Pa.
- Athletic director, Ashland High School, Ashland, Mass.
- Fitness services manager, Boston Sports Club-Wellesley, Wellesley, Mass.
- Physical therapist:
-Braintree Rehabilitation Hospital, Braintree, Mass.
-Physical Therapy of Harlem, Harlem, N.Y.
-Thomas Nicolla Physical Therapy, Troy, N.Y.
-University of Connecticut Health Center, Farmington, Conn.
-Vermont Sports Medicine Center, Brandon, Vt.
- Kessler Institute for Rehabilitation, Saddle Brook, N.J.
- Firefighter/EMT, Burlington Fire Department, Burlington, Vt.
- Public health nurse, City of Newburyport, Newburyport, Mass.
- Anesthesiology research fellow, Columbia University/St. Luke's Hospital, NYC
- Orthopedic resident, Einstein Healthcare Network, Philadelphia, Pa.
- Chiropractor:
-Enhanced Chiropractic Solutions, NYC
-Chiropractic Wellness Connection, Cottleville, Mo.
-Owner, White Plains Chiropractic and Sports Center, White Plains, N.Y.
- Operations manager, Fitcorp, Boston, Mass.
- Clinical research manager, Florida State University, Tallahassee, Fla.
- Population health specialist and project manager, Harbor Health Services, Boston, Mass.
- Health educator/research associate, Harvard Pilgrim Health Care Institute, Boston, Mass.
- Nurse practitioner/internal medicine, Harvard Vanguard Medical Assoc., Boston, Mass.
- Exercise physiologist/strength and conditioning, Holy Redeemer Hospital, Meadowbrook, Pa.
- Director of sport psychology, Kansas State University, Manhattan, Kan.
- Physician assistant:
-Landmark Medical Center, Woonsocket, R.I.
-New York Presbyterian/Cornell Medical Hospital, NYC
-Orlin & Cohen Orthopedic Associates, Long Island, N.Y.
-Saint Vincent Hospital, Harvard, Mass.
-Schenectady Family Health Services, Schenectady, N.Y.
- Executive director, Department of Medicine, Massachusetts General Hospital, Boston, Mass.
- Post-bacalaureate IRTA fellow, National Institutes of Health, Boston, Mass.
- Nutritionist and registered dietitian, North Jersey Nutrition, Teaneck, N.J.
- Human capital management/wellness communications director, Plus One Health Management at Goldman Sachs, NYC
- Registered dietitian, wellness coach, sports nutritionist, RG Nutrition and Wellness, Stoneham, Mass.
- Product developer/footwear, Saucony, Lexington, Mass.
- Director of account management, SCIO Health Analytics, Boston, Mass.
- Clinical project manager, Sirtris Pharmaceuticals, Cambridge, Mass.
- Culinary director for nutrition in the nitchen, Blum Center for Health, Rye, N.Y.
- Athletic trainer, Sage Colleges, Troy, N.Y.
- Athletic trainer, Valley Hospital, Ridgewood, N.J.
- Multisport education manager, USA Triathlon, Colorado Springs, Colo.
- Member services coordinator, USRowing, Princeton, N.J.
- Owner, Virtuoso Fitness, Pittsburgh, Pa.
- Head coach and strength/conditioning coach, Wesleyan College Athletics, Macon, Ga.
- Field hockey coach, Westfield State University, Westfield, Mass.
- Pediatric nurse practitioner, Yale University Children's Diabetes Program, New Haven, Conn.
Graduate Schools: A sampler of where our alumni go
- Athletic Training: Plymouth State University, Bridgewater State University
- Chiropractic Medicine: New York Chiropractic College
- Dental School: Tufts University
- Exercise Science/Physiology: Springfield College, Florida State University, University of Massachusetts-Amherst, Syracuse University
- Human Genetics: Johns Hopkins University
- Medicine: University of Pennsylvania
- Nutrition: Boston University, New York University
- Nursing: New York University, University of Connecticut, Regis College
- Osteopathic Medicine: Touro University, British College of Osteopathic Medicine
- Physician Assistant: Mass College of Pharmacy & Health Sciences, Daeman College, Pace University
- Physical Therapy: Elon University, Massachusetts General Hospital, Nova Southeastern University
- Public Health: University of Delaware, University of Michigan
- Veterinary School: Cornell University


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2017-07-24 07:29:07.000STARKVILLE, Miss. -- The man who helped take down Ole Miss football coach Hugh Freeze is a lifelong Mississippi State fan who attended his first Bulldogs game 37 years ago and has the university's logo tattooed on his left hand. But he insi
2017-07-24 07:23:16.637A roundup of the past week's notable boxing results from around the world: Sunday at Tokyo Hiroto Kyoguchi W12 Jose Argumedo Wins a strawweight title Scores: 116-111 (twice), 115-112 Records: Kyoguchi (8-0, 6 KOs); Argumedo (20-4-1, 12 KOs)
2017-07-23 17:59:40.523INDIANAPOLIS -- Kasey Kahne earned a career-defining victory as the sun set at Indianapolis Motor Speedway. That was appropriate, because the sun could end up setting on his NASCAR career over the next six months. An 18-time winner in the Cup Series,
2017-07-23 07:58:25.703SOUTHPORT, England -- Spectators sneaked inside the ropes, scurrying along the 18th fairway at Royal Birkdale, shrieking as Jordan Spieth headed toward the final green to a loud ovation from the packed grandstands and the coronation everyone expected
2017-07-17 10:23:06.447SOUTHPORT, England -- It was supposed to be plain sailing, a cakewalk, a stroll in the dunes. Instead we witnessed a day of drama. Who deserves the plaudits and who needs homework before the year's final major, the PGA Championship at Quail Hollow
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2017-07-23 06:28:43.740SOUTHPORT, England -- Don't compare Jordan Spieth to anyone else. Just don't do it. That's a challenging assignment, considering what he just accomplished in winning the 146th Open Championship. Spieth's great escape with bogey on a 13th-hole expedit
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2017-07-22 05:47:20.153SOUTHPORT, England -- The very first time Jordan Spieth had the chance to sleep on a share of the lead at a major championship, it was Saturday night at the Masters in 2014, and he was 20 years old. He lay awake, well after midnight, mulling the enor
2017-07-22 05:34:04.893SOUTHPORT, England -- Jordan Spieth stood dead center in the middle of Royal Birkdale's 18th fairway Saturday afternoon, some 40 yards ahead of Matt Kuchar. Spieth watched his playing partner take aim at the flagstick and nearly hole his approach for
2017-07-22 05:48:57.923SOUTHPORT, England -- Royal Birkdale Golf Club's assistant professional Gregg Pettersen received the call at 10 o'clock Friday night: "Do you want to play in The Open?" OK, in truth he was only marking for South Africa's Shaun Norris, but the galleri
2017-07-12 12:42:50.897All times are Eastern. For British Standard Time, add five hours. For Johannesburg, add six hours. For India, add 9.5 hours. For Australia, add 14 hours. For New Zealand, add 17 hours. (a) denotes amateur Round 4 Open tee times 2:55 a.m.: Danny W
2017-07-22 05:46:08.703SOUTHPORT, England -- Rory McIlroy arrived at Royal Birkdale a week ago, head down, ready to go to work. He had missed consecutive cuts on the European Tour, including the Irish Open, the tournament that benefits his own foundation. And he was starin
2017-07-22 05:39:20.697SOUTHPORT, England -- Jordan Spieth, 23, heads into the final round of the 146th Open holding a 3-shot lead, which is nothing new. The Texan has sat atop the leaderboard an astonishing 14 different times after a round in his young career. If he can
2017-07-22 05:35:05.587SOUTHPORT, England -- In majors, just like in the NFL, defense wins championships. But every now and then, when conditions are right, you gotta let the offense loose. Consider a caddie an on-field head coach. Saturday, Royal Birkdale was defenseless
2017-07-22 05:31:25.643SOUTHPORT, England -- Two years ago, Jack Nicklaus was asked about golf's greatest scoring barrier. At the time, there were 26 rounds of 63 at a major -- five more have since been added -- but never a 62. The most accomplished player in the game's hi

subset: commoncrawl


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Let us know when your receive great advice so we can thank our lawyers and point others with similar questions in the right direction.Got it!
My boss's trademark is being questioned . He did an intent to use application and another party filed a cancellation based on him lacking a bona fide intent . Evidence I could provide are the conversations with developers prior to filing the application which discuss the plans for the products . However , there is a very casual relationship with me and my subcontractors . I don't want to submit copies to anyone of our chat logs because I don't want to tarnish their names with them participating in such vulgar conversations . Quotes may leaked onto the web somehow during the proceedings with the opposing party citing dialogue . Can we edit out the obscenities and submit documents with a bunch of black marks through them ? Or , can I just have them sign a document swearing to the pertinent facts ?
Your question makes it seem like you are an attorney asking. Ill assume that unless you tell me otherwise.
The alternative to the actual statements would be an affidavit, or sworn statemt, as you suggest.
The testimony or an affidavit from your boss would also be good, and from anyone else who knew of your bosses intent to use the mark.
If you are not a trademark attorney and you are trying to defend the itu in a cancellation proceeding, I would highly recommend working with a trademark attorney to ensure that the best options are examined, and so that nothing is missed.
Good luck
I am not your lawyer and this comment does not create an attorney-client relationship. Plus, it is not a good idea to base legal decisions solely on comments posted to an open forum board. However, I hope that you will seek the advice of an attorney if you feel that your situation requires such expertise.Ask a similar question
Agreed, an affidavit is one way around this, but be cautious in your wording of the affidavits because depending on the wording, if swearing the discussed the intent in a recorded chat log could open up the possibility of the logs themselves being requested by opposing counsel.
My disclaimer is simply that Avvo already has an adequate disclaimer.Ask a similar question
An affidavit is ok, but it's not quite the same as an affidavit backed up by documentary evidence. Is there other documentary evidence that you could use? Are there internal company emails discussing plans to use the trademark? Is there a business plan? If all you've got are the vendor emails, I would be inclined to redact out the obscenities -- they're completely irrelevant -- and submit redacted copies. Good luck.Ask a similar question
I agree with Attorney Lewis -- the supporting documents that purport to establish your company's bona fide intent to use the mark must be produced. Those documents will be responsive to the other side's Request for Production of Documents. Which means that you MUST produce them or else face a sanction -- which could be a negative inference that you have no such supporting documents. At which point the declarations from your subcontractors become suspect, lose evidentiary weight and could be deemed inadmissible.
The default TTAB Protective Order [availble via the link below] automatically applies in all cases unless the parties craft their own version and get it approved by the TTAB. The default Protective Order has a "Highly Confidential" designation that shields documents so designated from public disclosure. You and your own trademark attorney need to decide how best, if at all, to shield the subcontractor's emails from disclosure [not at all, redaction, or protection order]. I would strongly suggest not at all. By virtue of being your subcontractors they need something from you: work and money. In exchange they can withstand some very remote possibility of embarassment over their spicy language.
You need a trademark attorney. Good luck.
The above is general information ONLY and is not legal advice, does not form an attorney-client relationship, and should NOT be relied upon to take or refrain from taking any action. I am not your attorney. You should seek the advice of competent counsel before taking any action related to your inquiry.Ask a similar question
I totally agree. It's inconceivable that these won't be responsive to a request for production of documents. The question then becomes whether to seek to redact, produce as is or seek a protective order. You definitely need a trademark attorney, and it looks like there's a good one in Sacramento! Good luck. Brett
How do you seek to redact? Can I just give them the documents with black lines in them?
Thank you.
No, you may not simply black out the offensive language. Your own attorney will explain how it's done -- IF that is what the two of you decide to do. If your company's potential trademark registration is valuable then it will invest in hiring an attorney. It's apparent choice not to means that the registration is either not valuable [so you're wasting everyone's time] or it does not have the $30K or so to hire an attorney to handle the matter [so you're working for a company teetering on failure]. Good luck.
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(The Hosting News) – Software provider Citrix announced two new SaaS tools on Thursday, providing new cloud computing platforms to IT clients.
"Netscaler Cloud Gateway" allows users to manage SaaS delivery to users while "Netscaler Cloud Bridge" helps IT clients connect their data centers to external clouds.
In a press release commenting on Netscaler Cloud Gateway, Citrix stated the software "is a powerful solution that collapses and eliminates application silos, providing a unified entrance for seamless access and management of apps delivered from private or public clouds."
Among other things, the platform provides deployment abilities to IT administrators, while giving users functions such as allocation, provisioning, unified licensing distribution and sign-on security measures.
In a press release concerning Netscaler Cloud Bridge, the company said the platform helps make "the cloud a seamless extension of the enterprise network."
Citrix also recently announced that it added multi-touch support to its Receiver software, providing functionality with mobile devices and tablets.
Citrix, started in 1989, provides services such as virtualization, cloud computing and SaaS to clients in the IT industry. For more information on the company, visit: http://www.citrix.com


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Join Couchsurfing to see Sergio's full profile. It's free!
About Me
To fulfill my dream of working as a Freelancer while traveling around the world
I'm a very easy going person and tend to talk a lot. I love to meet new people anytime I can, learn about their culture and everything.
I prefer to travel to natural places rather than cities, but I don't mind going anywhere.
Since 2014, I've been traveling around the world while taking pictures for my blog: The Arcae Project (https://www.facebook.com/TheArcaeProject) Check it out!
I've been able to work on the road in order to keep traveling and it has given me the best experiences of my life.
"What we think, we become." - Buddha
Archaeology, music, design, internet, technology, books, culture
Music, Movies, and Books
My all-time favorite book is The Little Prince.
American Gods, Lamb, The Expanse Series, The Silo Saga, Sand, The shadow of the wind, Everything is illuminated, The painter of battles and 100 years of solitude are other books that I've enjoyed.
Give me good Science Fiction!
I love indie music, rock, folk, house, dubstep and almost everything that can make my feet move.
One Amazing Thing I've Done
Making an online business and traveling around the world since 2014, while taking pictures for my blog: The Arcae Project (https://www.facebook.com/TheArcaeProject)
Teach, Learn, Share
I'd be happy to teach you how to curse like a real Mexican.
What I Can Share with Hosts
Lots of stories, tons of laughs, beautiful pictures and a handful of beers!
Countries I've Visited
Armenia, Austria, Belize, Bulgaria, Cambodia, Canada, China, Czech Republic, El Salvador, Georgia, Germany, Guatemala, Honduras, Hungary, India, Israel, Laos, Malaysia, Mexico, Nepal, Peru, Poland, Serbia, Slovakia, South Korea, Thailand, Turkey, United States, Viet Nam
Countries I've Lived In
Honduras, Mexico, Viet Nam


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|Message view
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|Bill Stoddard <b...@wstoddard.com>
|Re: Potential memory leak in /modules/cache/mod_mem_cache.c
|Fri, 04 Nov 2005 13:23:33 GMT
Xuekun Hu wrote: > So, same reason. Also in file mod_mem_cache.c around line 786, there > is a malloc(mobj->m_len), and a few lines later, another > malloc(obj->count) is performed. > > If the second malloc fails, I think also should add something like > free(mobj->m); > mobj->m = NULL; > > reasonable? No. Once a cache object is allocated, it will be cleaned up by cleanup_cache_object when the reference count drops to 0. To understand how this works, find this line of code. apr_pool_cleanup_register(r->pool, obj, decrement_refcount, apr_pool_cleanup_null); When r->pool is cleaned up, decrement_refcount is called. decrement_refcount will call cleanup_cache_onject when the refcount goes to 0. Bill
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Tuesday, August 21, 2007
Back to School with Grand Rounds!
This week's Grand Rounds is up, with a "Back to School" theme. I'm delighted to be included, even though I'm not close to being ready to go back to school myself next week!
And don't forget that I'm hosting Grand Rounds next week (preaching Sunday, school starts Monday, hosting GR on Tuesday: what was I thinking?). Here's my call for submissions.
Happy reading!
Posted by Susan Palwick at 8:25 AM
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|Publication number
|Publication type
|Application number
|Publication date
|Dec 30, 2003
|Filing date
|Jan 4, 2001
|Priority date
|Jan 5, 2000
|Fee status
|Also published as
|Publication number
|Troy D. Wood, E. Peter Maziarz, III, Sarah A. Lorenz, Thomas P. White
|Original Assignee
|The Research Foundation Of State University Of New York
|Export Citation
|BiBTeX, EndNote, RefMan
|Patent Citations (28), Referenced by (52), Classifications (20), Legal Events (6)
|External Links: USPTO, USPTO Assignment, Espacenet
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/174,548 filed Jan. 5, 2000, which is hereby incorporated by reference in its entirety.
The present invention generally relates to nano-electrospray emitters, nano-electrospray devices containing such emitters, methods of making such emitters, and use thereof.
Electrospray ionization ("ESI") (Whitehouse et al., 1985; Meng et al., 1988) has revolutionized the use of mass spectrometry in bioanalytical chemistry because of its ability to transfer large macromolecules from solution into the gas-phase as intact multiply-charged molecular ions. A special advantage of ESI is the ease with which it may be coupled to liquid chromatography ("LC") (Banks, 1995), capillary electrophoresis ("CE") (Smith et al., 1993), and capillary electrochromatography ("CEC") (Schmeer et al., 1994). In the last five years, a number of research groups have developed methods for decreased sample consumption in ESI by using much lower flow rates (nL/min) than with conventional ESI (μL/min) (Emmett and Caprioli, 1994; Kriger et al., 1995; Valaskovic et al., 1995a; Kelly et al., 1997; Wilm and Mann, 1996). Of these low flow ESI methods, the flow rate is controlled by some type of pump in microspray (Emmett and Caprioli, 1994), whereas in nanospray the flow rate is controlled by the potential difference between the emitter and counter-electrode (Wilm and Mann, 1996). Typically, nanospray has been accomplished by pulling silica or glass substrates under heat to produce tapered emitters with small inner diameters, e.g., a few μm. Attomole level sample consumption has been achieved using nanospray (Valaskovic et al., 1995a; Valaskovic et al., 1996a).
While nanospray provides an avenue to achieve low-level detection limits with MS using only a few μL of sample, even at high salt and/or buffer concentrations, most nanoliter-flow ESI emitters suffer from short operating lifetimes, poor durability, and/or low reproducibility. For example, metallized coatings have been applied to emitter substrates to provide electrical contact at the ESI outlet, but such emitters are highly susceptible to deterioration by electrical discharge (Valaskovic et al., 1995a).
To overcome this serious limitation, methods to increase metallized emitter lifetime in nanospray have been developed. These include chemical derivatization of an organofunctional silane on the emitter substrate prior to metallization (Kriger et al., 1995), by depositing a SiOx overcoating atop the metallized layer (Valaskovic et al., 1996b), or by controlled electrochemical deposition of metal film onto the emitter substrate (Kelly et al., 1997). Though these multi-layer and electrolysis methods have shown improvement in emitter durability for low flow ESI, they are tedious and time-consuming. Alternatively, nonmetallized emitters have been employed with low flow ESI by remotely coupling the ESI voltage to the emitters (Emmett et al., 1998; Hannis and Muddiman, 1998). A disadvantage of this approach, however, is that it relies on the conductive properties of the solution used, rather than the conductive properties of the emitter itself. Solution conditions may vary widely for both LC and capillary separations, and such emitters may exhibit wide differences in performance depending upon the mobile phase conditions used in the separation. Placing a metal wire into the tip for electrical contact has proved beneficial for durability (Kelleher et al., 1997; Cao and Moini, 1997; Fong and Chan, 1999), however it would be preferable to avoid the need to regulate the insertion, removal, or adjustment of an independent metal wire.
As stated by Lausecker et al., a good, long-acting and stable electrical contact on the CZE capillary terminus remains the main challenge (Lausecker et al., 1998) in performing MS coupled to capillary separations. Thus, to fully exploit the advantages of nanospray-MS with CE for the purposes of molecular species identification of analytes in biological fluids (i.e., at sub-picomole levels), a stable and/or reproducible type of nanospray emitter must be developed.
For nanospray ESI-MS emitters to be useful in coupling to either CE or CEC, the emitters must remain stable throughout the separation process. Failure of the emitter during the course of the separation is not acceptable. For quantification in particular, if calibration curves of multiple analytes at multiple concentration levels are to be constructed, single emitters with longer lifetimes or multiple emitters showing reproducible performance and ionization efficiency are needed.
The present invention is directed to overcoming these deficiencies in the art.
One aspect of the present invention relates to a nanospray emitter including an emitter body which includes a fluid inlet, an outlet orifice, and a passage communicating between the fluid inlet and outlet orifice; and an electrically conductive polymer coating on at least a portion of the emitter body.
A further aspect of the present invention relates to a nano-electrospray device including a counter-electrode and a nanospray emitter of the present invention whose inlet is capable of fluid communication with a fluid source including a fluid containing one or more analytes. Either the counter-electrode or the nanospray emitter can be either coupled to a power supply, with the other being grounded, for development of a suitable electrical potential between the counter-electrode and the nanospray emitter, which causes the fluid to be drawn through the passage of the nanospray emitter for discharge from the outlet orifice.
Yet another aspect of the present invention relates to a method for making a durable nanospray emitter. This method includes the steps of providing a nanospray emitter body comprising a fluid inlet, an outlet orifice, and a passage communicating between the fluid inlet and outlet orifice; and casting a thin film of an electrically conductive polymer coating onto at least a portion of the nanospray emitter body.
A still further aspect of the present invention relates to a method of forming a nanospray of a solution which includes passing a solution including an analyte through a nanospray emitter of the present invention under conditions effective to electrically charge the solution in a manner to emit the solution from the emitter in the form of a nanospray.
Another aspect of the present invention relates to a method of analyzing a solution for an analyte in the solution. This method includes passing a solution including an analyte through a nanospray emitter of the present invention under conditions effective to electrically charge the solution in a manner to emit the solution from the emitter in the form of a nanospray, and then analyzing the nanospray emission in a manner suitable to detect an analyte present in the solution.
The conductive polymer coatings on emitters of the present invention are a significant departure from previously existing nanospray emitter coatings, all of which are based on metals. The conductive polymer-coated nanospray emitters of the present invention overcome the most problematic limitations of metallized emitters: they provide long-term durability while being simple to coat. With respect to a preferred embodiment, polyaniline ("PANI") coated emitters are desirable because the PANI coating is resistant to corrosion (Wessling and Posdorfer, 1999) while maintaining high mechanical stability and antistatic properties (Triveldi and Dhawan, 1992). No PANI contamination is observed in the ESI spectra. Moreover, in its conductive form PANI is optically transparent (green), allowing for direct viewing of the ESI sample, and possesses outstanding adherence to glass properties (Manohar et al., 1991). PANI-coated nanospray emitters are relatively simple to produce and are highly resistant to electrical discharge. The sensitivity enhancement of PANI-coated nanospray emitters is similar to that of gold-coated emitters vs. normal ESI for tested analytes. Because of the significantly greater durability for the PANI coated emitters of the present invention, the emitters are available for use in analyzing, e.g., via CE-MS, highly complex biological matrices including, without limitation, drugs and their metabolites, neuropeptides, neurotransmitters, and biomolecules from complex biological fluids and tissues.
FIGS. 1A-B illustrate a PANI-coated nanospray emitter of the present invention. FIG. 1A is a longitudinal cross-sectional view of the PANI-coated nanospray emitter, illustrating the relationship between the emitter body and the PANI coating thereon. The PANI coating is adjacent to the outlet orifice of the emitter body. FIG. 1B is an image, prepared by photomicrograph, which illustrates the optical transparency of a water-soluble PANI-coated emitter of the present invention.
FIG. 2 is a longitudinal cross-sectional view of another embodiment of a PANI-coated nanospray emitter of the present invention. The emitter includes a PANI coating adjacent the inlet to the emitter body.
FIG. 3 is a longitudinal cross-sectional view of another embodiment of a PANI-coated nanospray emitter of the present invention. The PANI coating covers substantially the entire length of the emitter body (i.e., from the inlet to the outlet orifice).
FIG. 4 illustrates an nano-electrospray device, including a counter-electrode coupled to a power supply and a grounded nanospray emitter whose inlet is in fluid communication with a fluid supply (i.e., containing a solution to be analyzed by MS).
FIG. 5 is a nanospray ESI-Fourier transform mass spectrum ("FTMS") of the polymer mixture PEG-1000/PDMS-1250/methyl-terminated PEG 2000. The symbols that follow represent various polymer species: (Δ) singly-sodiated PEG-1000, (▴) doubly-sodiated PEG-1000, (★) doubly-sodiated PEG-2000, (⋆) triply-sodiated PEG-2000, and () singly-sodiated PDMS-1250. Top inset: expansion of m/z region 910-1030.
FIG. 6 is a nanospray FTMS spectrum of vasoactive intestinal peptide using PANI from xylene dispersions as the coating. Total peptide consumed: 5 femtomoles.
FIGS. 7A-C are nanospray ESI-FT mass spectra of equine cytochrome c (30 μM). FIG. 7A is a normal ESI-FT mass spectrum, sum of 10 scans. Total sample consumed=17 pmol. FIG. 7B is a nanospray ESI-FT mass spectrum using gold-coated emitters, sum of 10 scans. Total sample consumed=1.3 pmol. FIG. 7C is a nanospray ESI-FT mass spectrum using xylene-soluble PANI dispersions coated onto the emitters, sum of 10 scans. Total sample consumed=680 fmol.
FIGS. 8A-B are aligned nanospray-FTMS of 29.2 μM myoglobin (49/49/2 methanol/water/glacial acetic acid, v/v/v) using a nanospray emitter that was coated with water-soluble PANI. Qualitatively, the same charge states are observed at both 5 min (top, FIG. 6A) or 160 min (bottom, FIG. 6B) after the initiation of nanospray, with slightly improved S/N observed at 160 min.
One aspect of the present invention relates to a nanospray emitter which overcomes the previously mentioned deficiencies in the art. The nanospray emitter of the present invention includes an emitter body which includes a fluid inlet, an outlet orifice, and a passage communicating between the fluid inlet and outlet orifice; and an electrically conductive polymer coating on at least a portion of the emitter body.
The emitter body can be formed of any material suitable for use in nanospray emitters, preferably a glass or glass ceramic material. Suitable materials include, without limitation borosilicate glasses and glass ceramics, aluminosilicate glasses and glass ceramics, and fused silica glasses.
Emitter bodies can be pulled from glass or glass ceramic capillary tubes, forming a tapered (e.g., conical) portion of the body which has the outlet orifice at the tip thereof (see Wilm and Mann, 1994). The emitter pulling technique can be performed using a fiber-pulling device (Sutter Instruments) equipped with either a resistance heating element or a CO2 laser. Instruments equipped with a CO2 laser are better adapted for use with more substrates (than those equipped with resistance heating elements); only the CO2 laser is capable of heating fused silica for subsequent pulling. It has been shown that this method exhibits reproducible emitter production with respect to taper geometry and orifice inner diameters (Valaskovic et al., 1995b).
To open the emitter orifice, if necessary or desired, a number of techniques may be used. According to a first approach, HF etching can be performed according to known techniques (Valaskovic et al., 1995b). According to another approach, which is perhaps safer to the operator and, therefore, preferred, a micro-pipette beveler (Sutter Instruments, model BV-10) can be employed to grind the emitter ends in a controlled fashion. Both approaches enable tailoring of the orifice inner diameter. The orifice preferably has an inner diameter of less than about 20 μm, more preferably between about 1 μm to about 5 μm, even more preferably about 3 μm to about 5 μm.
Alternatively, suitable emitter bodies of the type described above can be purchased (in a pre-pulled shape) from various commercial suppliers, including New Objective (Cambridge, Mass.).
The electrically conductive polymer coating can be any suitable polymer coating which (i) has a conductivity of at least about 1.0�10−3 S/cm (at 25� C.) and (ii) will resist electrical discharge (i.e., and remain electrically conductive) under electrospray conditions for a duration of at least about 1 hour.
The conductivity of the electrically conductive polymer is preferably between about 1.0�10−3 to about 5 S/cm (at 25� C.).
The durability of the electrically conductive polymer is dependent upon its longevity under normal electrospray conditions. Preferably, the electrically conductive polymer will resist electrical discharge for at least about 3 to 6 hours, more preferably at least about 24 hours, even more preferably several days or more.
Without being bound by theory, it is believed that suitable electrically conductive polymer coatings of the present invention additionally exhibit electrostatic adherence to the glass or glass ceramic substrate. For example, it is believed that PANI coatings possess positively charged sites within the polymer that interact with negatively charged sites on the glass or glass ceramic substrate.
Although not critical, it is desirable for the thickness of the electrically conductive polymer to be substantially uniform over the entire portion of the emitter body which is coated with the polymer. The thickness of the electrically conductive polymer coating is preferably less than about 10 μm, more preferably between about 2 μm to about 4 μm.
The electrically conductive polymer coating can be applied to any portion of the emitter body which will allow for electrical charge to be conveyed to the solution passing through the emitter body. For example, the electrically conductive polymer coating can be applied to a portion of the emitter body adjacent to the inlet thereof (distal end), a portion of the emitter body adjacent to the outlet orifice thereof (proximal end), or substantially the entire emitter body. Depending on the placement of the coating (proximal vs. distal end), the shape of the nanospray plume can be affected. For example, coating at the proximal end typically yields a narrower nanospray plume whereas coating at the distal end typically yields a broader nanospray plume. Under most circumstances, a narrower plume will be desirable to capture (via the inlet of an analytical device such as a mass spectrometer) a greater volume of the nanospray emission.
One preferred electrically conductive polymer is a polyaniline ("PANI") coating. PANI is unique amongst electroactive polymers in that its conductive state is achieved by protonation of N in the polymer backbone, as opposed to p-doping and partial oxidation of the polymer π system (Genies et al., 1990). The analytically pure base form of PANI is given in structure (I) below, where the fully reduced state "leucoemeraldine" corresponds to Y=1 and the fully oxidized state "pernigraniline" corresponds to Y=0. When Y=0.5, PANI is said to be in its "emeraldine" oxidation state. Treatment of the "emeraldine" oxidation state of PANI with high acid concentrations (˜1 M HCl) leads to the formation of the "emeraldine salt", in which the oxidized repeat units in structure (I) are converted to hydrochloride salt functionalities. It is the emeraldine salt form of PANI that is conductive (MacDiarmid et al., 1987).
The PANI coating is characterized by the following properties: high resistance to electrical discharge, with coatings lasting for several days or more under electrospray conditions; a conductivity of about 5 S/cm at 25� C. and 1 M HCl (MacDiarmid et al., 1987); resistance to corrosion (Wessling and Posdorfer, 1999) while maintaining high mechanical stability and antistatic properties (Triveldi and Dhawan, 1992); optical transparency (green), allowing for direct viewing of the ESI sample; and outstanding adherence to glass properties (Manohar et al., 1991).
One embodiment of the nanospray emitter of the present invention is illustrated in FIG. 1A. The emitter 10 includes a tapered (i.e., conical) body 12 having a fluid inlet 14, an outlet orifice 16, and a passage 18 communicating between the fluid inlet and outlet orifice. Adhered to a portion of the exterior of the body 12 is a PANI coating 19, which extends to the proximal end containing the outlet orifice 16. As shown in FIG. 1B, a nanospray emitter of the present invention, which is coated with a water-soluble PANI coating, is translucent. A translucent emitter enables visual examination of the fluid passing through the passage 18.
A second embodiment of the nanospray emitter of the present invention is illustrated in FIG. 2. The emitter 20 includes a tapered (i.e., conical) body 22 having a fluid inlet 24, an outlet orifice 26, and a passage 28 communicating between the fluid inlet and outlet orifice. Adhered to a portion of the exterior of the body 22 is a PANI coating 29, which extends to the distal end containing the inlet 24.
A third embodiment of the nanospray emitter of the present invention is illustrated in FIG. 3. The emitter 30 includes a tapered (i.e., conical) body 32 having a fluid inlet 34, an outlet orifice 36, and a passage 38 communicating between the fluid inlet and outlet orifice. Adhered to substantially the entire exterior of the body 32 is a PANI coating 39, which extends from the proximal end containing the outlet orifice 36 to the distal end containing the inlet 24.
A further aspect of the present invention relates to a method of making a nanospray emitter of the present invention. Basically, the method is carried out by providing a nanospray emitter body which includes a fluid inlet, an outlet orifice, and a passage communicating between the fluid inlet and outlet orifice; and then casting a thin film of an electrically conductive polymer coating onto at least a portion of the nanospray emitter body.
The process step of casting can be achieved by a number of procedures.
According to a first approach, application of the conductive polymer coating can be carried out by dipping the portion of the emitter body into a soluble suspension which includes the conductive polymer. The soluble suspension can be either an aqueous suspension or in an organic solvent. After dipping, the solvent is allowed to evaporate, leaving behind the PANI coating on the portion of the emitter body dipped into the suspension.
When aqueous suspensions are employed, the PANI is preferably derivatized to ensure its solubility in water. A water soluble PANI derivative (Chen and Hwang, 1995) is commercially available from Monsanto (St. Louis, Mo.). Although PANI films cast from aqueous suspensions are susceptible to dissolution by some protic solvents, such PANI films are still functional for nanospray.
When organic suspensions are employed, a suitable organic solvent should be selected on the basis of its ability to form a soluble suspension of PANI without degradation of the quality of PANI film produced upon evaporation of the solvent. Suitable organic solvents include, without limitation, xylene and a mixture of xylene and a diacetone alcohol (e.g., 4-hydroxy-4-methyl-2-pentanone), typically in an approximate 1:1 ratio. Unlike PANI films cast from aqueous solutions, PANI films cast from xylene solutions are not susceptible to degradation by exposure to protic solvents. To preclude tackiness of the resulting PANI film, not more than about 5% by weight of PANI should be suspended in an organic solvent.
To ensure that the film resulting from the dipping process does not interfere with the outlet orifice, this first approach may also include the step of passing a fluid through the passage of the emitter body during the dipping step and, optionally, during the curing step. The fluid is preferably a gas, such as air, or a non-reactive gas, such as nitrogen.
To control the rate of deposition of the conductive polymer onto the emitter body (and, thus, control the thickness of the conductive polymer and its uniformity along the length of the emitter body), it may be desirable to utilize a device (e.g., a lab jack) which can be used to lower and raise the emitter body into the suspension containing the conductive polymer at a suitable rate. For PANI suspensions, the device can be used to withdraw the emitter body from the suspension at a rate of about 5 mm/s. This should achieve a PANI coating of suitable thickness.
According to a second approach, the step of casting can be carried out by polymerizing the conductive polymer onto the portion of the emitter body in an acidic solution by oxidation. By way of example, oxidative polymerization of aniline (0.10 M) can be carried out in aqueous solution by (NH4)2S2O8 (ammonium peroxydisulfate 0.1 M) treatment at ˜0-5� C. in 1 M aqueous HCl, as described in earlier protocols (Chiang et al., 1986; MacDiarmid, 1987). Preferably, a vanadium oxide catalyst is utilized to afford consistent results from the polymerized films (MacDiarmid, 1987). A portion of the emitter body is dipped into the catalyzed solution to polymerize the film on the portion in the solution. The time length in which the emitter body is present in the catalyzed solution will affect the thickness of the resulting polymerized film. Typically, a time length of about 5 to about 60 minutes is sufficient, more preferably about 15 to about 20 minutes. The thicknesses of the electrically conductive film should be as set forth above.
Upon removal of the emitter body from the catalyzed solution, polymerization can be quenched by washing the emitters with aqueous NH4OH (Chiang et al., 1986; Fong and Schlenoff, 1995) Afterward, the emitters can be washed with 1 M HCl to ensure the film is in its conductive state, as indicated visually (for PANI, by a green film).
As noted above, a gas can be blown through the passage of the emitter body to prevent clogging of the outlet orifice by the polymer.
According to a third approach, the step of casting can be carried out by coating the portion of the emitter body in a solution containing a non-conductive base form of the conductive polymer, and then doping the coated emitter to produce a conductive polymer coating. By way of example, PANI film can be formed out of N-methyl-2-pyrrolidinone solution using commercially available PANI (Polysciences, Inc., Warrington, Pa.). Conductive PANI is immersed into basic solution (pH ˜8) for several hours to produce the non-conductive emeraldine base form (structure I), which is soluble in N-methyl-2-pyrrolidinone. The N-methyl-2-pyrrolidinone is then doped with 1.0 M HCl (pH ˜0) to produce the conductive form of PANI, or "emeraldine salt." The emitter substrate is dipped into the doped solution, then removed and dried. This coating procedure produces optically transparent PANI films that conduct electricity.
As noted above, a gas can be blown through the passage of the emitter body to prevent clogging of the outlet orifice by the polymer.
According to a fourth approach, the step of casting can be carried out by introducing the emitter body, or portion thereof, into an RF discharge chamber and then exposing the emitter body, or portion thereof, to aniline monomers under conditions effective to coat the portion of the emitter body with polyaniline.
By way of example, the emitter body can be introduced into an RF discharge chamber (Vargo et al., 1989; Vargo et al., 1991) along with aniline vapor (a few tenths of a torr) and exposed to RF discharge (about 50-100 kHz RF discharge frequency at about 10-50W) to deposit an electrically conductive PANI film on the surface of the emitter body (Bhat and Joshi, 1994; Cruz et al., 1997; Gong et al., 1998). Interestingly, Gong et al. showed that the physical and chemical properties of PANI films could be changed by altering the rf-plasma discharge conditions (Gong et al., 1998). With increasing discharge duration and rf-discharge power, the relative percentage of quinoid groups (relative to benzenoid) was increased, as was the degree of aliphatic cross-linking (Gong et al., 1998). However, the relative percentage of free radicals was found to be higher when lower rf-plasma powers were employed. Optionally, to enhance conductivity, the reaction chamber can be doped with iodine vapor (Bhat and Joshi, 1994) or the relative humidity can be increased (Cruz et al., 1997).
Having prepared an emitter of the present invention, it is intended to be used in a nano-electrospray device for creation of low sample volume nanosprays. Therefore, a further aspect of the present invention relates to a nano-electrospray device which includes a nanospray emitter of the present invention, as described above. The nano-electrospray device 40, illustrated in FIG. 4, includes a grounded emitter 10 of the present invention and a counter-electrode 42 connected to a power supply 44. The emitter 10 is supported by an emitter mount 44 such that the emitter can be coupled in fluid communication with a fluid source 50, which holds a fluid (containing one or more analytes) to be examined. During use of the nano-electrospray device, the solution delivered to the tip of the emitter body experiences the electric field associated with the maintenance of the tip at high potential. Assuming a positive potential, for example, positive ions in solution (i.e., in a condensed phase) will accumulate at the surface, which is drawn out in a downfield direction to establish a Taylor cone. At a high enough imposed electric field, the cone is drawn to a filament which produces positively charged droplets via a budding process when the surface tension is exceeded by the applied electrostatic force. As solution at the tip is dispersed into a gas phase (of the nanospray), additional fluid is drawn to the tip via capillary action. Thus, development of a suitable electrical potential between the counter-electrode 42 and the emitter 10 (i.e., through the electrically conductive polymeric coating on the emitter) causes the fluid to be drawn through the passage of the emitter for discharge from the outlet orifice by establishing an electrical field force which exceeds the surface tension of the fluid.
Although FIG. 4 shows the emitter being grounded and the counter-electrode connected to the power supply, it should be appreciated by one of skill in the art that a suitable electrical potential can also be activated by grounding the counter-electrode and coupling the emitter to the power supply.
The nano-electrospray device 40 is intended to be used in conjunction with any one of the following devices: a mass spectrometer, whose inlet can be coupled to receive the nanospray from the outlet orifice of the nano-electrospray device 40; liquid chromatography columns, whose outlet can be coupled to the inlet of the emitter on the nano-electrospray device 40; capillary electrophoresis columns, whose outlet can be coupled to the inlet of the emitter on the nano-electrospray device 40; and capillary electrochromatography columns, whose outlet can be coupled to the inlet of the emitter on the nano-electrospray device 40. One of skill in the art may readily appreciate that other equipment can readily be coupled to the nano-electrospray device 40 to introduce a fluid to be analyzed into the inlet thereof or to receive a nanospray from the outlet orifice thereof.
Thus, a further aspect of the present invention relates to a method of analyzing a solution for an analyte in the solution. This method is carried out by passing a solution including an analyte through a nanospray emitter of the present invention under conditions effective to electrically charge the solution in a manner to emit the solution from the emitter in the form of a nanospray, and then analyzing the nanospray emission in a manner suitable to detect an analyte present in the solution. Basically, the nanospray emission can be analyzed using now known or hereafter developed devices which are suitable for the intended analysis to be performed. For example, without being limited thereby, a mass spectrometer can receive the nanospray emission to identify one or more analytes in the nanospray emission.
With the use of a nano-electrospray device of the present invention, it is possible to determine the pharmacokinetic behavior of pharmaceutical agents, the behavior of endogenous biochemicals (e.g., neuropeptides, neurotransmitters, nucleic acids, proteins, other intercellular signaling molecules, etc.), or the interaction of pharmaceutical agents with endogenous biochemicals in the formation of drug complexes (e.g., drug-protein complexes).
The following examples are intended to be illustrative of the present invention, but are no means intended to the limit the scope thereof.
The following materials were used in the Examples provided below:
water-soluble conductive PANI dispersions (5% aqueous, conductive form) was obtained from Monsanto (St. Louis, Mo.), where the water-soluble PANI is functionalized with proprietary tethers and is otherwise commercially available from Monsanto as PANAQUA (without the tethers, PANI is not soluble in water (Chen, 1995));
xylene-soluble conductive PANI dispersions (Mw 117,000 Da, 48.16% xylenes, 12.62% butyl cellosolve, the remainder solid PANI) was obtained from Monsanto (St. Louis, Mo.);
polyethylene(glycol) (Mn 1000, PEG-1000), poly(dimethylsiloxane) (Mn 1250, PDMS-1250), and equine cytochrome c were obtained from Sigma; and
methyl-terminated polyethylene(glycol) (Mn 2000, ME PEG-2000) was obtained from Aldrich (Milwaukee, Wis.).
Electrospray ionization-mass spectra analysis were performed using the following instrumentation:
All ESI mass spectra were acquired using a 3 tesla Bruker Daltonics BioApex 30es (Billerica, Mass.) Fourier transform mass spectrometer equipped with an Analytica of Branford (Branford, Conn.) nanospray source. A metal cap (250 μm) was fitted over the capillary inlet to the mass spectrometer to reduce the diameter of the opening and to decrease the probability of electrical discharge stripping the conductive coating off the mass spectrometer's inlet capillary, making it functionally useless. PANI-coated nanospray emitters were inserted into the emitter mount (FIG. 4) and loaded with sample by the following means. A gas-tight Hamilton syringe containing the sample was connected to a union inlet by 1.5 cm length of fluorinated ethylene polymer (FEP) tubing ({fraction (1/16)}″ OD, 0.03″ ID). A 3 cm segment of Polymicro Technologies (Phoenix, Ariz.) fused silica tubing (186 μm OD, 50 μm ID) connected to the outlet. The silica tubing was then inserted into the PANI-coated emitter to its taper, and sample was slowly injected using the syringe. In this way, the liquid analyte forms a plug without bubbles in the emitter tip. The PANI-coated emitter was held at ground and positioned to ˜0.5-2 mm distance from the metal-capped capillary inlet to the mass spectrometer (as viewed from a microscope mounted on the nanospray source) using the micrometer on the nanospray source. The onset of nanospray was initiated with the counter-electrode at ˜−650 V, and spray was conducted typically at −650 to −1200 V. Ions were accumulated in the external hexapole (Lau et al., 1997) and electrostatically injected into the Infinity cell (Caravatti and Allemann, 1991) (2.0 V trapping potential) using Sidekick (U.S. Pat. No. 4,924,089 to Caravatti). Frequency-sweep excitation from m/z 294 to 2400 was applied at an amplitude of ˜30 Vpp. Detection was in direct mode (bandwidth 0-156250 Hz). The data sets were apodized with a Gaussian function, Fourier transformed, and displayed in magnitude mode using XMASS 4.0.2 on a Silicon Graphics (Mountain View, Calif.) RPC 4600 INDY data station.
Gold-coated and uncoated borosilicate glass emitters (1.2 mm OD, 0.69 mm ID) pulled to tapers for the ESI outlet with 4�1 μm ID were purchased directly from New Objective (Cambridge, Mass.). The uncoated emitters were gently swiped using the sealed end of a melting tube upon which aqueous conductive PANI had been applied while the emitter was rotated manually. Though this application method does not provide a PANI coating of uniform thickness, it is easy to confirm by visual inspection whether or not the ESI outlet is covered by a transparent green coating of PANI. A very low flow of air could be (but was not always) run through the emitter to prevent clogging of the emitter orifice during application of water-soluble PANI. The PANI-coated emitter was then allowed to air dry. Within three minutes, the PANI coating was sufficiently adherent to the substrate such that the emitter was usable for nanospray.
Photomicrographs (FIG. 1B) were obtained using a Nikon Optiphot confocal microscope in the Confocal Microscopy and 3-D Imaging Lab in the School of Medicine and Biomedical Sciences at SUNY-Buffalo.
Nanospray was initiated with PANI-coated emitters when the counter-electrode voltage was between −600 and −1200 V. Because of the transparent green PANI coating over the emitter substrate (FIG. 1B), one could determine whether any air bubbles were present that might interfere with nanospray using a microscope. An example of nanospray (˜40 nL/min flow rate) using the water-soluble PANI-coated emitters is shown in FIG. 5, which is a mixture of three synthetic polymers dissolved in methanol:2-propanol:10 mM NaOH (49:49:2, v/v/v): methyl-terminated PDMS (Mn 1250), PEG (Mn 1000), and methyl-terminated PEG (Mn 2000). The NaOH was added to provide a cation source for creating PDMS ions. Singly- and doubly-charged oligomer ions of PEG-1000 and doubly- and triply-charged oligomer ions of methyl-terminated PEG-2000 are observed, as are singly-sodiated oligomer ions of PDMS. Similar results were obtained when xylene-soluble PANI was used.
Interestingly, normal flow ESI (i.e., no nanospray) of this same mixture reveals only the PEG distributions, and the PDMS is absent. In distinguishing it from nanospray, normal flow ESI is defined here as being performed with a metal needle, (grounded relative to counter-electrode held at −3 kV), 50 μm i.d., at 1 μL/min flow rate. Perhaps the higher surface area-to-liquid volume ratio of nanospray vs. normal ESI enables ionization and detection of the more hydrophobic PDMS. No evidence for any ion derived from PANI is found in the spectrum. Thus, PANI-coated nanospray emitters can be used without the worry of possible contamination from the PANI. In spite of the spectral complexity of the data for the three polymers in FIG. 5, the high mass resolving power of FTMS allows for easy identification of charge state (top inset) (Henry, 1991), while the ionic species' identities can be confirmed by high mass accuracy (Maziarz et al., 1999).
The PANI-coated emitter used for the sample in FIG. 5 maintained continuous spray for 40+ minutes before sample was exhausted. Inspection of this emitter under a microscope did not indicate any clear signs of degradation. This was actually somewhat surprising, since it was observed that PANI cast from water-soluble dispersions will dissolve in protic solvents (methanol, ethanol, and water), though such films are exceedingly stable in the presence of 2-propanol and acetonitrile. Of course, the fluid never comes in direct contact with the PANI film (save perhaps at the very edge of the tip). Thus, while some dissolution of the film might be expected if a protic solvent comes into direct contact with PANI cast from water-soluble dispersions, this has not yet prevented the tips from being durable.
A 50/50 mixture of methanol and 2-proponal was injected into the emitter and spray was reinitiated to rinse the emitter tip. The next day, this same emitter was used to collect nanospray mass spectra for numerous samples, with rinsing in-between. Even after running multiple samples over two days through the same PANI-coated emitter, stable signal could be obtained without electrical discharge and the emitter continued to be functional. Indeed, with rinsing in between sample loadings, the PANI-coated emitters can be reused many times. While such capability may not be needed for general sample analysis, the availability of stable emitters for coupling to sheathless CE-MS is still an analytical challenge (Lausecker et al., 1998). Thus, the current PANI-coated emitters may prove useful in coupling nanospray to CE-MS.
The emitters are extraordinarily stable to electrical discharge. Under normal operating conditions, no evidence of electrical arcing was observed (either by destruction of the PANI coating or from direct observation of the PANI tip). Arcing could only be induced when the counter-electrode voltage was set above −3 kV and when the tip was placed within 0.2 mm of the counter-electrode (indeed, arcing could only be guaranteed if the tip was inserted directly into the inlet hole in the counter-electrode). Gold-coated tips could be induced to arc at much lower voltages (˜−1 kV) even 2 mm away from the counter-electrode.
Gold-coated and uncoated borosilicate glass emitters (1.2 mm OD, 0.69 mm ID) pulled to tapers for the ESI outlet with 4�1 μm ID were purchased directly from New Objective (Cambridge, Mass.). The uncoated emitters were gently swiped using the sealed end of a melting tube upon which xylene conductive PANI had been applied while the emitter was rotated manually. The xylene conductive PANI suspension obtained from Monsanto (St. Louis, Mo.) was modified to reduce the PANI concentration to not more than about 5% by weight. Though this application method does not provide a PANI coating of uniform thickness, it is easy to confirm by visual inspection whether or not the ESI outlet is covered by a transparent green coating of PANI. A very low flow of air could be (but was not always) run through the emitter to prevent clogging of the emitter orifice during application of xylene-soluble PANI. The PANI-coated emitter was then allowed to air dry. Within three minutes, the PANI coating was sufficiently adherent to the substrate such that the emitter was usable for nanospray.
As noted previously, PANI has high mechanical stability and anti-static properties (Trivedi and Dhawan, 1992). Part of the stability imparted by the PANI coating may be due to its thickness. PANI films cast from xylene-soluble dispersions, however, are insensitive to degradation by protic solvents.
An example of the routine low detection limits achievable with PANI-coated nanospray emitters using an FTMS detector is shown in FIG. 6. Here, vasoactive intestinal peptide (VIP) (1 ng/μL in methanol/water/acetic acid 49/49/2) was electrosprayed at ˜40 nL/min over 25 sec using a borosilicate nanospray emitter coated with a xylene-soluble dispersion of PANI. Thus, ˜17 nL sample volume, or 17 picograms (5 femtomoles) of total peptide were used to acquire the ESI-FTMS spectrum in FIG. 6. Flow rate was determined by injecting 5 μL of sample and waiting until tip stops producing signal; for the tip used in FIG. 6, ˜120 min.
Use of PANI films cast from xylene-soluble dispersions with nanospray is shown in FIG. 7. FIG. 7a is an ESI-FT mass spectrum of equine cytochrome c (30 μM, 50/50 v/v methanol/water) using conventional ESI (flow rate=1 μL/min). The spectrum shown in FIG. 7b is nanospray of an identical cytochrome c solution using instead gold-coated nanospray emitters (flow rate ˜100 nL/min). Using nanospray emitters coated with xylene-soluble PANI, the same sample (flow rate ˜40 nL/min) generates the spectrum observed in FIG. 7c. The normal ESI spectrum reveals a multiplicity of charge states from 6+ to 15+, while the nanospray spectra reveal charge states over the range 6+ to 11+.
The discrepancy between charge state distributions for cytochrome c using conventional ESI and nanospray is not inherently obvious. One possibility is that ions are desolvated more quickly in nanospray than in ESI, thus ions spend more time in the "gas-phase" if formed from nanospray. Perhaps this results in increased charge stripping. Of course, another possibility is that conformational effects may limit charging of a protein, though it is not immediately clear why conformation should be any different for ions produced by nanospray vs. ESI.
One of the key attributes of low flow ESI that has been noted is its high sensitivity (Emmett and Caprioli, 1994; Kriger et al., 1995; Valaskovic et al., 1995a; Kelly et al., 1997; Wilm and Mann, 1996; Valaskovic et al., 1996a). The total amount of cytochrome c consumed to acquire the spectrum in FIG. 7a was 17 pmol, while only 1.3 pmol was required to obtain the spectrum in FIG. 7b (using gold-coated nanospray emitters) and 680 fmol to obtain the spectrum in FIG. 7c (using PANI-coated nanospray emitters). Thus, PANI-coated nanospray emitters show improved sensitivity (as do gold-coated emitters) vs. normal flow ESI. While the total signal and signal-to-noise ratios are superior with the PANI-coated emitter in FIG. 7c vs. the gold-coated emitter in FIG. 7b, it is likely this is due to the flow rate differences used to acquire the two spectra.
The durability of the PANI films for nanospray is also made evident in FIG. 8. Here, the same nanospray emitter is used to acquire nanospray-FT mass spectra of myoglobin over 160 minutes. In comparison to convention gold-coated emitters, the PANI coated emitters of the present invention were useful after far longer than the typical 15-30 minutes survival on the ESI-FTMS equipment utilized herein (which is consistent with their reported survival, Valaskovic et al., 1995a). Thus, this demonstration illustrates that nanospray emitters with PANI coatings have similar sensitivity yet superior durability to gold-coated emitters.
In addition, several types of cast PANI films exhibit solvent stability. As shown in Table 1 below, in general PANI films cast from water-soluble dispersions have much lower stability in protic solvents than those cast from xylene-soluble films. While degradation of the films by the naked eye is often difficult to detect, inspection via microscopy shows that solvent exposure can, in fact, dissolve PANI coatings at the emitter orifice in most cases. However, even when PANI films do dissolve upon solvent exposure, the PANI-coated nanospray emitters were still operable over a period of days, and could be reused many times. Films produced from PANI dispersions in xylene (Monsanto, Inc.) show stability to protic solvents, but prove to be very sticky at concentrations above 5% PANI by weight.
Solvent Stabilities of PANI Films
Water-soluble PANI
Xylene-soluble PANI
dissolves immediately
stable over 24 h.
Stable for 10 min., slightly
Slow dissolution,
soluble after 20 h.
complete within 24 h.
Forms suspension in minutes,
Stable over 24 h.
complete dissolution after 20 h.
forms suspension in minutes
Stable over 24 h.
Stable over 20 h.
Stable over 24 h.
glacial acetic
Stable for 10 min., but dissolves
Stable over 24 h.
completely within 20 h.
nitric acid
dissolves immediately
Slight dissolution
within 24 h.
PANI film turns blue, dissolves
stable after 24 h.,
slowly, and will not produce stable
no color change
ESI even if emitter is removed
from solvent before dissolution
dissolves immediately
Stable over 24 h.
ESI-LC/MS has proved valuable for drug development because of its ability to provide structural information and quantify the drug and its metabolites with lower detection limits than UV spectroscopy (Lee et al., 1997). For example, paclitaxel (taxol) is an alkaloid that has received considerable attention because of its efficacy in treating ovarian tumors (Suffness, 1995). Paclitaxel promotes tubulin polymerization and inhibits depolymerization, thereby inhibiting cell division in cancer cells (Parness et al., 1982). A sharpened picture of the mechanistic and metabolic pathways of paclitaxel may lead to improvements in its clinical efficacy (Dorr, 1997). Thus, in spite of FDA approval, further review of paclitaxel's biotransformation is still needed.
An HPLC assay of paclitaxel in mouse plasma using UV detection was developed by Sharma et al. (Sharma et al., 1994). This method can quantify paclitaxel for up to 4-8 h after I.V. injection. Adequate description of the pharmacokinetics requires quantification over a 24-36 h period. Such information from test subjects is currently unavailable. Information of this type would prove useful in determining dosage requirements and treatment frequency for cancer patients using paclitaxel in clinical trials.
ESI-MS and ionspray-MS have been used for structural characterization of paclitaxel and its metabolites (Poon et al., 1996; Volk et al., 1997; Lee et al., 1997; Kerns et al., 1995; Blay et al., 1993; Bitsch et al., 1993). The following ESI-MS protocol shall be used to analyze paclitaxel in mouse plasma samples. Paclitaxel is ESI stable in an 80% acetonitrile:20% ammonium acetate buffer solution at pH 3-7 (pH adjusted by adding acetic acid), and the presence of both monomeric and dimeric species has been noted. In fact, the paclitaxel dimer has also been observed under 95% water/5% acetonitrile conditions, which are much more like the in vivo conditions which would be found in patients. Indeed, the dimer may play a role in the bioactivity of paclitaxel (Balasubramanian et al., 1994).
By extending this work to nanospray, it is expected to lower these detection limits significantly so that paclitaxel can be detected over the entire course of a 24-36 h blood plasma pharmacokinetics study. Thus, the nanospray emitters described here may be used to detect in vivo levels of paclitaxel and its metabolites. This is especially important because, to date, no determination has been achieved on the presence of in vivo levels of the paclitaxel dimer, which may play a significant role in the polymerization of tubulin proteins to form microtubules. In addition, since sodiated paclitaxel dimer is the dominant dimeric species, nanospray can be used to examine whether high (mM) levels of sodium salts further enhance dimerization. Such studies would be virtually impossible with ESI since high salt concentrations make ESI virtually unusable; however, nanospray is much more tolerant of such high salt concentrations.
Each of the references cited above and listed below is hereby incorporated by reference in its entirety.
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Although the invention has been described in detail for the purposes of illustration, it is understood that such detail is solely for that purpose, and variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention which is defined by the following claims.
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Owner name: RESEARCH FOUNDATION OF STATE UNIVERSITY OF NEW YOR
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text:
This article lists Jakko's gear in his Silesia Sound Studios, including this one.more
When the Rockman first came out it was a must have for late night practice; then Zoom came along not long after. The Zoom gave you a wider pallet of tone with amps, effects. The forefather of amp modeling. The size alone makes this one a keeper and nostalgic like a Atari game system.


text:
McCall's 7461; ©1981; Misses' and Women's Jacket and Skirt: Jacket has tucked fronts, shoulder pads and top-stitch trim; long or short sleeves with shaped hemline can be turned up. Jacket may be worn with purchased belt. Four-gore, flared skirt has left side zipper.
Links to reviews/blog postsEdit
- SheilaDeesSewVintage Size 40 Size 42
- WhiletheCatNaps
- PurplePlaidPenguin Bust 44
- SimplySewing Size 38, Uncut/FF


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|[jira] Updated: (LUCENE-1001) Add Payload retrieval to Spans
|Fri, 21 Nov 2008 02:38:44 GMT
[ https://issues.apache.org/jira/browse/LUCENE-1001?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Mark Miller updated LUCENE-1001: -------------------------------- Attachment: LUCENE-1001-fix.patch Okay, I still understand like 2% of spans, but I think I have fixed the bug. After finding a match, but before finding a min match, we were pulling the payload - works fine when the match is the min match, but otherwise we actually have to wait to get the payload until we have crunched in on the min match. I had an idea of this before, and the code before I touched it tried to grab the payloads at this point - the problem is, in finding the min match, you've often advanced passed the term position of interest to find out there was no such min match. So you have to save the possible payload ahead of time, and either find a new one or use the possible saved one. Sucks to have to add extra loading, but at the moment I don't see how to do it differently (I admittedly can't see much in spans). Thats all partly a guess, partly probably true. Non the less, this patch handles the previous test cases, plus the bug case reported above. I have also added a modified version of the given test for the bug to the span battery of tests. Thanks Jonathan! > Add Payload retrieval to Spans > ------------------------------ > > Key: LUCENE-1001 > URL: https://issues.apache.org/jira/browse/LUCENE-1001 > Project: Lucene - Java > Issue Type: New Feature > Components: Search > Reporter: Grant Ingersoll > Assignee: Grant Ingersoll > Priority: Minor > Fix For: 2.4 > > Attachments: LUCENE-1001-fix.patch, LUCENE-1001.patch, LUCENE-1001.patch, LUCENE-1001.patch, LUCENE-1001.patch, LUCENE-1001.patch, LUCENE-1001.patch, LUCENE-1001.patch, LUCENE-1001.patch > > > It will be nice to have access to payloads when doing SpanQuerys. > See http://www.gossamer-threads.com/lists/lucene/java-dev/52270 and http://www.gossamer-threads.com/lists/lucene/java-dev/51134 > Current API, added to Spans.java is below. I will try to post a patch as soon as I can figure out how to make it work for unordered spans (I believe I have all the other cases working). > {noformat} > /** > * Returns the payload data for the current span. > * This is invalid until {@link #next()} is called for > * the first time. > * This method must not be called more than once after each call > * of {@link #next()}. However, payloads are loaded lazily, > * so if the payload data for the current position is not needed, > * this method may not be called at all for performance reasons.
 > *
 > *
 > * WARNING: The status of the Payloads feature is experimental. > * The APIs introduced here might change in the future and will not be > * supported anymore in such a case. > * > * @return a List of byte arrays containing the data of this payload > * @throws IOException > */ > // TODO: Remove warning after API has been finalized > List/*<byte[]>*/ getPayload() throws IOException; > /** > * Checks if a payload can be loaded at this position. > *
 > * Payloads can only be loaded once per call to > * {@link #next()}. > *
 > *
 > * WARNING: The status of the Payloads feature is experimental. > * The APIs introduced here might change in the future and will not be > * supported anymore in such a case. > * > * @return true if there is a payload available at this position that can be loaded > */ > // TODO: Remove warning after API has been finalized > public boolean isPayloadAvailable(); > {noformat} -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online. --------------------------------------------------------------------- To unsubscribe, e-mail: firstname.lastname@example.com For additional commands, e-mail: email@example.com
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