bluuebunny/crossref_metadata_2025 huggingface dataset:
Practicing IEF‐PAGE of EPO: The impact of detergents and sample application methods on analytical performance in doping control
Authors: Reichel Christian
Published: December 2010

Electrophoretic techniques, namely isoelectric focusing polyacrylamide gel electrophoresis (IEF‐PAGE) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) are key techniques used for confirming the doping‐related abuse of recombinant erythropoietins and analogs. IEF‐PAGE is performed on horizontal slab‐gels with samples applied to the surface of the gel. Different sample application techniques can be employed, but application pieces and applicator strips are most frequently used. However, defective application pieces cause lane streaking during IEF of erythropoietin (EPO), which is especially pronounced in the acidic region of the gel. The effect is due to an incompatibility of the substance used for enhancing the wettability of the cellulose‐based commercial product and is batch‐dependant. A detailed mass spectrometric study was performed, which revealed that defective sample application pieces (bought between 2007 and 2010) contained a complex mixture of alcohol ethoxylates, alcohol ethoxysulfates, and alkyl sulfates (e.g. SDS). Anionic detergents, like the sulfates contained in these application pieces, are in general incompatible with IEF. Alternative application techniques proved partly useful. While homemade pieces made of blotting paper are a good alternative, the usage of applicator strips or shims is hampered by the risk of leaking wells, which lead to laterally diffused samples. Casting IEF‐gels with wells appears to be the best solution, since sustained release of retained proteins from the application pieces can be avoided. Edge effects do not occur if wells are correctly filled with the samples. The evaluation of EPO‐profiles with defects is prohibited by the technical document on EPO‐analytics (TD2009EPO) of the World Anti‐Doping Agency (WADA). Copyright © 2010 John Wiley & Sons, Ltd.
On the use of Kinetex™‐C18 core‐shell 2.6 µm stationary phase to the multiclass determination of antibiotics
Authors: Samanidou Victoria F. , Karageorgou Eftichia G.
Published: December 2010

Fast and accurate analysis is a prerequisite in all analytical fields especially in food, biological, pharmaceutical, and environmental samples. The new trend of ultra performance liquid chromatography (LC) has the main drawback of expensive instrumentation, which can't be easily found in low‐budget analytical laboratories. The evolution of core shell technology has contributed to this direction, since ultra high efficiency can be achieved on common LC instrument platforms.

Herein the novel core shell analytical column, KINETEX ™2.6 µm, (150 mm × 4.6 mm) was comparatively studied against two conventional reversed‐phase silica‐based and one monolithic column. Eight antimicrobial agents representing two different classes: penicillins and amphenicols, were separated using a typical 400 bar high performance liquid chromatography (HPLC) equipment.

Comparison of column performance was carried out by calculation of the number of theoretical plates N, the tailing factor Tf, the relative retention time RRT, the retention factor k, the resolution factor Rs, and the precision of the retention time and peak area.

Optimal chromatographic conditions were used to validate the method. Its applicability was proven by the analysis of veterinary drug formulations. The examined antibiotics were well resolved within 17 min. Limit of quantitation values were 25.9 ng for amoxicillin, 14.1 ng for ampicillin, 41.6 ng for thiamphenicol, 9.6 ng for oxacillin, 23.5 ng for florfenicol, 26.7 for cloxacillin, 23.5 ng for chloramphenicol and 42.3 ng for dicloxacillin for 20 µL injection volume. The developed method can be easily and readily transferred to any laboratory. Copyright © 2010 John Wiley & Sons, Ltd.
Microwave‐accelerated preparation and analytical characterization of 5‐ethoxy‐N,N‐dialkyl‐[α,α,β,β‐H4]‐ and [α,α,β,β‐D4]‐tryptamines
Authors: Tearavarich Ruchanok , Hahnvajanawong Viwat , Dempster Nicola , Daley Paul F. , Cozzi Nicholas V. , Brandt Simon D.
Published: December 2010

The increased interest inN,N‐dialkyl tryptamines is a reflection of their diverse range of biologically active properties. Deuterated derivatives are of interest for use as internal standards in bioanalytical or pharmacological assays. The present study reports on the synthesis of twelve novel 5‐ethoxy‐N,N‐dialkyl‐[α,α,β,β‐H4]‐tryptamines and their [α,α,β,β‐D4]‐counterparts following the Speeter and Anthony procedure. The normally time‐consuming reduction step was carried out in 5 min under microwave‐accelerated conditions. Good yields were obtained using tetrahydrofuran as the solvent at 150 °C. The resulting 24 tryptamines have been characterized by 1D/2D nuclear magnetic resonance spectroscopy and gas chromatography ion trap mass spectrometry. Differential fragmentation of side‐chain‐related iminium ions has been observed as a key principle. Because manyN,N‐dialkyltryptamines are available outside of traditional pharmaceutical supply chains as so‐called ‘research chemicals’, the availability, as standards, of these newN,N‐dialkyltryptamines will aid in identifiying novel tryptamines arising from these other souces. They should therefore be of immediate value within forensic, research, and public health contexts. Copyright © 2010 John Wiley & Sons, Ltd.
Ultra‐performance liquid chromatography electrospray ionization–tandem mass spectrometry method for the estimation of miglitol in human plasma using metformin as the internal standard
Authors: Jain Rajeev , Lukram Ojitkumar , Dwivedi Ashish
Published: December 2010

A rapid and sensitive method for the determination of miglitol in human plasma was developed using ultra‐performance liquid chromatographic separation with tandem mass spectrometry detection. The preparation of samples required a deproteinization step with acetonitrile. Chromatography was performed on a 5 µ (50 mm × 4.6 mm, ID.) C18 inertsil column, with the mobile phase consisting of acetonitrile 2 mM and ammonium acetate (pH 3.5) with formic acid. Detection was performed using an Applied Biosystems Sciex API 2000 mass spectrometer set at unit resolution in the multiple reaction monitoring mode. Electrospray ionization was used for ion production. The mean recovery of miglitol was 88.9%, with the lower limit of quantification set at 150 ng/mL. Linearity was established for concentrations in the range of 150–4000 ng/mL, with a coefficient of determination (r2) of 0.9981. This assay method makes use of the increased sensitivity and selectivity of tandem mass spectrometric detection, resulting in high‐throughput analysis of miglitol for bioequivalence studies. Copyright © 2010 John Wiley & Sons, Ltd.
The detection of doping by means of chromatographic methods
Authors: Donike Manfred
Published: December 2010

This article was first published in German inDer Sportarzt, 1966,2,81–84as Der Dopingnachweis mit Hilfe chromatographischer Methoden. Translated and republished with permission.

Doping has become an issue in elite sport and necessitates sensitive detection assays that enable the identification of organic compounds on a microscale level in urine. In agreement with modern toxicological methods, sports drug testing approaches can utilize paper, thin layer or gas chromatographic methods to reveal the presence of prohibited substances such as strychnine, pervitine, captagone, benzedrine etc. in doping control specimens. Basic principles of these strategies are summarized and considerations for future applications discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Current Awareness in Drug Testing and Analysis
Authors:   John Wiley & Sons, Ltd.
Published: December 2010

In order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of drug testing and analysis. Each bibliography is divided into 18 sections: 1 Reviews; 2 Sports doping ‐ General; 3 Steroids; 4 Peptides; 5 Diuretics; 6 CNS agents; 7 Equine; 8 Recreational drugs ‐ General; 9 Stimulants; 10 Hallucinogens; 11 Narcotics; 12 Forensics; 13 Alcohol; 14 Tobacco; 15 Homeland security; 16 Workplace; 17 Product authenticity; 18 Techniques. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.
Spatial and seasonal variability of peatland stream ecosystems
Authors: Ramchunder Sorain J. , Brown Lee E. , Holden Joseph , Langton Rebecca
Published: December 2010

Headwater stream ecosystems draining blanket peat‐dominated catchments occur in many high‐latitude river systems. These systems are thought to be very sensitive to threats from climate change, and land‐use modification including artificial drainage, overgrazing, afforestation and vegetation burning. This study examined ten peatland streams in the headwaters of the River Tees to examine spatial and seasonal patterns of instream physicochemical variables and benthic macroinvertebrate communities across the stream network. Principle component analysis revealed significant positive relationships between catchment size and electrical conductivity, sulfate concentration, pH and median bed sediment size, and negative relationships with suspended sediment and aluminium concentrations. Seasonal variability was particularly evident in stream water temperature, benthic particulate organic matter and nitrate and chloride concentrations. Macroinvertebrate community abundance and diversity were typically similar across streams, but redundancy analysis demonstrated turnover of macroinvertebrate assemblages with increases in stream size. In particular, first‐ and second‐order streams hosted small‐sized stoneflies such asAmphinemura standfussiandNemoura cambrica, while larger streams (third‐ and fourth‐order) supported more mayflies and larger predatory stoneflies (e.g.Dinocras cephalotesandPerla bipunctata). Many environmental drivers of ecological patterns appear to work in synergy in peatland headwater streams, and controlled experiments may be necessary to disentangle some of the variables to guide effective conservation and management strategies in impacted peatland river systems. Copyright © 2010 John Wiley & Sons, Ltd.
Molybdenum Nitrosyl Complexes and Their Application in Catalytic Imine Hydrogenation Reactions
Authors: Dybov Alexander , Blacque Olivier , Berke Heinz
Published: December 2010

The reaction between [Mo(CO)4(NO)(ClAlCl3)] and the sterically hindered diphosphanes (P∩P) 1,3‐bis(diisopropylphosphanyl)propane (dippp, a), 1,2‐bis(diisopropylphosphanyl)ethane (dippe, b), 1,1′‐bis(diisopropylphosphanyl)ferrocene (dippf, c) and 1,2‐bis(dicyclohexylphosphanyl)ethane (dcype, d) produced the chlorides [Mo(P∩P)(CO)2(NO)Cl] (1a–1d), which were transformed into the corresponding hydrides [Mo(P∩P)(CO)2(NO)H] (2a–2d) by reaction with LiBH4 in Et3N at room temperature. The molybdenum–THF complex [Mo(dippp)(CO)2(NO)(THF)][BArF4] [3a; ArF = 3,5‐(CF3)2C6H3], obtained by the reaction of 2a with [H(Et2O)2][BArF4], was exemplarily tested in the hydrogenation of the imine PhCH=N(α‐naphthyl). Replacement of the [BArF4]– counterion by the more stable [B(C6F5)4]– anion greatly increased the catalytic activity. The use of in situ mixtures of the hydrides 2a–2d and [H(Et2O)2][B(C6F5)4] improved the hydrogenation activity. The hydride 2b in combination with [H(Et2O)2][B(C6F5)4] exhibited the highest TOF value of 123 h–1 in the reduction of PhCH=N(α‐naphthyl). The hydrogenation of the imines PhCH=NPh, p‐ClC6H4CH=NPh, p‐ClC6H4CH=N‐p‐C6H4Cl, PhCH=NCH(Ph)2 and PhCH=NMes showed TOF values of 34, 74, 41, 18 and 84 h–1 at room temperatureand a H2 pressure of 30 bar. A mechanism for the ionic hydrogenation with “proton‐before‐hydride transfer” is anticipated.
Spectroscopic and Photophysical Studies of Charge‐Transfer in a Cd8 Thiolate Cluster Complex Containing a Coordinated N‐Methyl‐4,4′‐bipyridinium Ligand
Authors: Fu Ming‐Lai , Adams Richard D. , Cristancho Dahiyana , Leon‐Plata Paola , Seminario Jorge M.
Published: December 2010

The hybrid cluster complex Cd8S(SPh)15(MeQ)·CH3CN (1) (MeQ+ = N‐methyl‐4,4′‐bipyridinium) was synthesized and characterized structurally by single‐crystal X‐ray diffraction analysis. The MeQ+ ion is coordinated to one of the cadmium atoms of the cluster by the nitrogen atom of its pyridine group. The reflectance absorption and emission spectra of complex 1 and it's parent complex [NEt4]2[Cd8S(SPh)16] (2) have been recorded and compared. DFT calculations reveal low energy cluster to ligand charge‐transfer processes involving the MeQ+ ligand.
Valuing the regulatory services provided by marine ecosystems
Authors: Mangi Stephen C. , Davis Clare E. , Payne Laura A. , Austen Melanie C. , Simmonds Dave , Beaumont Nicola J. , Smyth Tim
Published: December 2010

It is widely accepted that mankind derives benefits from ecosystem services provided by the marine environment. It is less clear how these benefits can be quantified in order to make objective and responsible environmental management decisions. Providing an economic quantification of these benefits is one approach that can help. While it is relatively simple to derive monetary values for benefits accruing from activities with an economic basis, such as food provision and tourism, different approaches must be taken to provide economic values for services with less obvious links to economic activity. Here we demonstrate how a range of approaches may be used to derive economic values for three very different ecosystem services provided by marine environments, namely the bioremediation of waste by marine biota, the fixation of carbon dioxide by photosynthetic marine organisms, and the sea defence role provided by wetlands in coastal areas of the UK. Copyright © 2010 John Wiley & Sons, Ltd.
Older adults' own reasoning for their alcohol consumption
Authors: Immonen Sirpa , Valvanne Jaakko , Pitkälä Kaisu H
Published: December 2010

Objective

The aim of the study was to investigate what the older adults themselves consider to be the reasons for their alcohol consumption.

Methods

The data were collected with a postal questionnaire from a random sample of 2100 elderly people (≥65 years) living in the medium‐sized city of Espoo, Finland. The response rate was 71.6% from the community‐dwelling sample. Altogether 868 persons responded that they use alcohol. Of them, 831 gave reasons for their drinking. We defined “at‐risk users” as consuming >7 drinks per week, or ≥5 drinks on a typical drinking day, or using ≥3 drinks several times per week.

Results

Main reasons given for alcohol consumption were “having fun or celebration” (58.7%), “for social reasons” (54.2%), “using alcohol for medicinal purposes” (20.1%), and “with meals” (13.8%). Younger age groups reported more often than the older age groups that they use alcohol for “having fun or celebration” and “for social reasons.” The older age groups used more often “alcohol for medicinal purposes”. Men used alcohol more often than women “as pastime” or “as sauna drink”. Those defined as “at‐risk users” reported using alcohol because of “meaningless life,” for “relieving depression,” “relieving anxiety,” and “relieving loneliness.”

Conclusions

Older adults have diverse alcohol consumption habits like people in other age groups. The oldest olds reported that they use alcohol for medicinal purposes. The “at‐risk users” admit they use alcohol because of meaningless life, and relieving depression, anxiety, and loneliness. Copyright © 2010 John Wiley & Sons, Ltd.
Trauma‐induced alterations in cognition and Arc expression are reduced by previous exposure to 56Fe irradiation
Authors: Rosi Susanna , Belarbi Karim , Ferguson Ryan A. , Fishman Kelly , Obenaus Andre , Raber Jacob , Fike John R.
Published: December 2010

Exposure to ionizing irradiation may affect brain functions directly, but may also change tissue sensitivity to a secondary insult such as trauma, stroke, or degenerative disease. To determine if a low dose of particulate irradiation sensitizes the brain to a subsequent injury, C56BL6 mice were exposed to brain only irradiation with 0.5 Gy of 56Fe ions. Two months later, unilateral traumatic brain injury was induced using a controlled cortical impact system. Three weeks after trauma, animals received multiple BrdU injections and 30 days later were tested for cognitive performance in the Morris water maze. All animals were able to locate the visible and hidden platform during training; however, treatment effects were seen when spatial memory retention was assessed in the probe trial (no platform). Although sham and irradiated animals showed spatial memory retention, mice that received trauma alone did not. When trauma was preceded by irradiation, performance in the water maze was not different from sham‐treated animals, suggesting that low‐dose irradiation had a protective effect in the context of a subsequent traumatic injury. Measures of hippocampal neurogenesis showed that combined injury did not induce any changes greater that those seen after trauma or radiation alone. After trauma, there was a significant decrease in the percentage of neurons expressing the behaviorally induced immediate early gene Arc in both hemispheres, without associated neuronal loss. After combined injury there were no differences relative to sham‐treated mice. Our results suggest that combined injury resulted in decreased alterations of our endpoints compared to trauma alone. Although the underlying mechanisms are not yet known, these results resemble a preconditioning, adaptive, or inducible‐like protective response, where a sublethal or potentially injurious stimulus (i.e., irradiation) induces tolerance to a subsequent and potentially more damaging insult (trauma). © 2010 Wiley Periodicals, Inc.
Icariin is more potent than genistein in promoting osteoblast differentiation and mineralization in vitro
Authors: Ma Hui‐Ping , Ming Lei‐Guo , Ge Bao‐Feng , Zhai Yuan‐Kun , Song Peng , Xian Cory J. , Chen Ke‐Ming
Published: December 2010

There has been a strong interest in searching for natural therapies for osteoporosis. Genistein, an isoflavone abundant in soy, and icariin, a prenylated flavonol glycoside isolated from Epimedium Herb, have both been identified to exert beneficial effects in preventing postmenopausal bone loss. However, the relative potency in osteogenesis between the individual phytoestrogen flavonoids remains unknown. The present study compared ability of genistein and icariin in enhancing differentiation and mineralization of cultured rat calvarial osteoblasts in vitro. Dose‐dependent studies in osteoblast differentiation measuring alkaline phosphatase (ALP) activity revealed optimal concentrations of genistein and icarrin for stimulating osteogenesis to be both at 10−5 M. Time course studies comparing the two compounds both at 10−5 M demonstrated that icariin treatment always produced higher ALP activity, more and larger areas of CFU‐FALP colonies and mineralized nodules, more osteocalcin secretion, and calcium deposition, and a higher level of mRNA expression of osteogenesis‐related genes COL1α2, BMP‐2, OSX, and RUNX‐2. However, they inhibited the proliferation of osteoblasts to a similar degree. In conclusion, although future in vivo studies are required to investigate whether icariin is more efficient in improving bone mass and/or preventing bone loss, our in vitro studies have demonstrated that icariin has a stronger osteogenic activity than genistein. In addition, while the prenyl group on C‐8 of icariin could be the active group that takes part in osteoblastic differentiation and explains its greater potency in osteogenesis, mechanisms of action, and reasons for the relative potency of icariin versus genistein need to be further studied. J. Cell. Biochem. 112: 916–923, 2011. © 2010 Wiley‐Liss, Inc.
The anandamide effect on NO/cGMP pathway in human platelets
Authors: Signorello Maria Grazia , Giacobbe Enrica , Passalacqua Mario , Leoncini Giuliana
Published: December 2010

In this study the effect of the endocannabinoid anandamide on platelet nitric oxide (NO)/cGMP pathway was investigated. Data report that anandamide in a dose‐and time‐dependent manner increased NO and cGMP levels and stimulated endothelial nitric oxide synthase (eNOS) activity. These parameters were significantly reduced by LY294002, selective inhibitor of PI3K and by MK2206, specific inhibitor of AKT. Moreover anandamide stimulated both eNOSser1177 and AKTser473 phosphorylation. Finally the anandamide effect on NO and cGMP levels, eNOS and AKT phosphorylation/activation were inhibited by SR141716, specific cannabinoid receptor 1 antagonist, supporting the involvement of anandamide binding to this receptor. Overall data of this report indicate that low concentrations of anandamide, through PI3K/AKT pathway activation, stimulates eNOS activity and increases NO levels in human platelets. In such way anandamide contributes to extend platelet survival. J. Cell. Biochem. 112: 924–932, 2011. © 2010 Wiley‐Liss, Inc.
Homogeneous deuteriodeiodination of iodinated tyrosine in angiotensin‐I using synthesized triethyl[2H]silane and Pd(0)
Authors: Pedersen Martin Holst Friborg , Martiny Lars
Published: December 2010

In our efforts to develop new reactions for the efficient labelling of peptides and proteins with tritium, we now report the use of silane hydrides together with homogenous Pd(0) catalysis for the protio‐ and deuteriodeiodination of an o‐iodo‐tyrosine containing peptide (angiotensin‐I) performed at room temperature. Copyright © 2010 John Wiley & Sons, Ltd.
Deuterated batracylin: deuterium–hydrogen exchange during synthesis and mass spectral analysis
Authors: Seltzman Herbert H. , Fix Scott E. , Risbood Prabhakar
Published: December 2010

Deuterium‐labeled analogs of the topoisomerase inhibitor batracylin were prepared for metabolism studies to further its evaluation as an antitumor agent. Established syntheses of unlabeled batracylin were adapted for the preparation of deuterated batracylin that was trideuterated in the quinazoline ring (d3‐batracylin 5), tetradeuterated in the isoindolo ring (d4‐batracylin 11), and heptadeuterated in both rings (d7‐batracylin 12). Extensive exchange of deuterium or hydrogen in the quinazoline ring was observed from an intermediate in the final concentrated sulfuric acid promoted deblocking/cyclodehydration step of the synthesis. Introduction of deuterated concentrated sulfuric acid in the final step both retained the label in the quinazoline‐labeled product and enabled extended labeling of a more exhaustively deuterated analog. Batracylin itself did not readily exchange aromatic protons under the reaction conditions but did loose and scramble deuterium atoms during mass spectral analysis leading to an under calculation of the deuterium content in the quinazoline ring. These results identify a chemical exchange process that can either undo, maintain, or facilitate the labeling process and also mass spectral analyses issues that must be taken into account to characterize and utilize these analogs and, more broadly, that can be recognized as potentially applicable to other classes of compounds. Copyright © 2010 John Wiley & Sons, Ltd.
Pigmented villonodular synovitis of joints
Authors: Mankin Henry , Trahan Carol , Hornicek Francis
Published: December 2010

Objectives

The objective of this study is to present two series of cases of pigmented villonodular disease of joints (PVNS) treated at different periods. The 215 cases from our hospital are current (1972–2009) and those 62 from the Jaffe collection from 1920 to 1968.

Methods

By use of our computerized tumor data system we were able to define age, gender, site, treatment, complications, and outcome. Examination of the material from the Jaffe collection included all of the above primary data but none on treatment and outcome.

Results

The data for the two systems studied were remarkably similar. The average ages were in mid years and the disorder was more frequent in females. The largest numbers of cases for both series were in the knee and foot and less commonly in hip, shoulder, and hand. The treatments were mostly surgical excision with the exception of the hip which required total hip replacement. The results show only a small number of recurrences, no metastatic disease and no deaths.

Conclusion

Pigmented villonodular disease of joints is a rare entity, mostly occurring in the knee and foot. The principal treatment is surgical excision which is most often successful in these sites but leads to problems at other locations, especially the hip. J. Surg. Oncol. 2011; 103:386–389. © 2010 Wiley‐Liss, Inc.
Erbium‐doped integrated waveguide amplifiers and lasers
Authors: Bradley J.D.B. , Pollnau M.
Published: December 2010

Erbium‐doped fiber devices have been extraordinarily successful due to their broad optical gain around 1.5–1.6 µm. Er‐doped fiber amplifiers enable efficient, stable amplification of high‐speed, wavelength‐division‐multiplexed signals, thus continue to dominate as part of the backbone of longhaul telecommunications networks. At the same time, Er‐doped fiber lasers see many applications in telecommunications as well as in biomedical and sensing environments. Over the last 20 years significant efforts have been made to bring these advantages to the chip level. Device integration decreases the overall size and cost and potentially allows for the combination of many functions on a single tiny chip. Besides technological issues connected to the shorter device lengths and correspondingly higher Er concentrations required for high gain, the choice of appropriate host material as well as many design issues come into play in such devices. In this contribution the important developments in the field of Er‐doped integrated waveguide amplifiers and lasers are reviewed and current and future potential applications are explored. The vision of integrating such Er‐doped gain devices with other, passive materials platforms, such as silicon photonics, is discussed.
Synthesis of new linear perfluoroalkyl polyethers starting from diols and tetrafluoroethylene
Authors: Howell Jon L. , Shtarov Alexander B. , Thrasher Joseph S. , Waterfeld Alfred , Murata Koichi , Friesen Chadron M. , Pérez Erik W.
Published: December 2010

New linear perfluoropolyalkylethers (PFPEs) with regularly sequenced repeat units are prepared by a four‐step synthesis starting from simple glycols and tetrafluoroethylene. The synthesis includes: (i) the reaction of glycols with tetrafluoroethylene to give bis(tetrafluoroethyl)alkyl ethers, (ii) the dehydrofluorination of the adduct with butyllithium to obtain bis(trifluorovinyl)alkyl ethers, (iii) the polymerisation of the trifluorovinyl ethers with glycols in the presence of base to make polyfluoroalkyl polyethers, and (iv) finally the fluorination of the polymers to provide PFPEs. The repeat units of the final PFPEs are altered by the variation of diols used in steps 1 and 3. Copyright © 2010 John Wiley & Sons, Ltd.
Facile Synthesis of Aqueous‐dispersible Nano‐PEDOT:PSS‐co‐MA Core/Shell Colloids Through Spray Emulsion Polymerization
Authors: Han Yu‐Kai , Yih Jenq‐Nan , Chang Mei‐Ying , Huang Wen‐Yao , Ho Ko‐Shan , Hsieh Tar‐Hwa , Lou Jhih‐Gong
Published: December 2010

This paper describes a novel spray emulsion polymerization technique for the preparation of aqueous‐dispersible nanoscale core/shell poly(3,4‐ethylenedioxythiophene) (n‐PEDOT) colloids doped with poly[(4‐styrenesulfonic acid)‐co‐(maleic acid)] (PSS‐co‐MA). Scanning electron microscopy and transmission electron microscopy images revealed that these n‐PEDOT:PSS‐co‐MA colloids possessed sharp core/shell morphologies. X‐ray diffraction and Raman spectroscopy measurements revealed semi‐crystalline morphologies and quinoid‐dominated structures for these n‐PEDOT:PSS‐co‐MA colloids. The conductivities of n‐PEDOT and n‐PEDOT:PSS‐co‐MA pellets were ca. 3.2 and 0.29 S · cm−1, respectively, suggesting that PSS‐co‐MA acted as a shell that blocked the hopping of charges from the n‐PEDOT core to neighboring latexes. The work functions of pristine n‐PEDOT and n‐PEDOT:PSS‐co‐MA, measured using photoelectron spectroscopy, were ca. 4.7 and 5.05 eV, respectively; thus, they are close to that of indium tin oxide. The PSS‐co‐MA used in this study featured two different types of interactive functional groups, which acted as oxidative sites, dopants, and core/shell stabilizers during polymerization.

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Morphology and properties of natural rubber with nanomatrix of non‐rubber components
Authors: Kawahara Seiichi , Chaikumpollert Oraphin , Akabori Keiichi , Yamamoto Yoshimasa
Published: December 2010

The morphology of natural rubber was observed by transmission electron microscopy. Nanomatrix of non‐rubber components such as proteins and phospholipids was found to be inherently formed in natural rubber, in which natural rubber particles of about 0.5 µm in average diameter were dispersed. The nanomatrix of non‐rubber components disappeared after deproteinization of natural rubber with urea. Stress at break of serum rubber was higher than that of deproteinized natural rubber, while strain at break did not change. When the amount of the non‐rubber components increased, the stress at break became significantly dependent upon the amount of non‐rubber components. Viscoelastic properties of natural rubber were also dependent upon the nanomatrix of non‐rubber components. Storage modulus of natural rubber increased significantly, when the amount of the non‐rubber components increased. Copyright © 2010 John Wiley & Sons, Ltd.
Biomedical applications of nanofibers
Authors: Leung Victor , Ko Frank
Published: December 2010

Nanofiber technology is an exciting area attracting the attention of many researchers as a potential solution to the current challenges in the biomedical field such as burn and wound care, organ repair, and treatment for osteoporosis and various diseases. Nanofibers are attractive in this field for several reasons. First, surface area on nanofibers is much higher compared to bulk materials, which allows for enhanced adhesion of cells, proteins, and drugs. Second, nanofibers can be fabricated into sophisticated macro‐scale structures. The ability to fabricate nanofibers allows renewed efforts in developing hierarchical structures that mimic those in animals and human. On top of that, a wide range of polymers can be fabricated into nanofibers to suit different applications. Nanofibers are most commonly fabricated through electrospinning, which is a low cost method that allows control over fiber morphology and is capable of being scaled‐up for mass production. This review explored two popular areas of biomedical nanofiber development: tissue regeneration and drug delivery, and included discussions on the basic principles for how nanofibers promote tissue regeneration and drug delivery, the parameters that affect nanofiber performance and the recent progress in these areas. The recent work on biomedical nanofibers showed that the large surface area on nanofibers could be translated into enhanced cell activities, drug encapsulation, and drug release rate control. Furthermore, by optimizing the electrospinning process via adjusting the material choices and fiber orientation, for example, further enhancement in cell differentiation and drug release control could be achieved. Copyright © 2010 John Wiley & Sons, Ltd.
The crystallization of polypropylene in multiwall carbon nanotube‐based composites
Authors: Marco Carlos , Naffakh Mohammed , Gómez Marián A. , Santoro Gonzalo , Ellis Gary
Published: December 2010

The crystallization process of isotactic polypropylene (iPP) was studied under both dynamic and isothermal conditions for a series of multiwall carbon nanotube (MWCNT) composites with nanotube concentrations between 0.1 and 1.0% by weight. The nucleation activity of the nanofillers was confirmed for both dynamic and isothermal crystallization, and was shown to be composition dependent. The effect of the nanofiller on the crystallization of iPP was discussed using the temperature coefficients obtained to determine the interfacial free energy and free energy of nucleation. The basal interfacial free energy decreased with respect to that of neat iPP by up to 15% for as little as 0.1% MWCNT, subsequently decreasing linearly with increasing nanotube concentration. This behavior is in line with the crystallization behavior of iPP with conventional nucleating agents. POLYM. COMPOS., 2011. © 2010 Society of Plastics Engineers
Enhanced electroluminescence from ZnO‐based heterojunction light‐emitting diodes by hydrogen plasma treatment
Authors: Zhang S. G. , Zhang X. W. , Wang J. X. , You J. B. , Yin Z. G. , Dong J. J. , Cui B. , Wowchak A. M. , Dabiran A. M. , Chow P. P.
Published: December 2010

The effects of H‐plasma treatment on the electroluminescence (EL) of ZnO‐based light‐emitting diodes have been investigated systematically. After H‐plasma treatment, the EL intensity of the n‐ZnO/AlN/p‐GaN device is observed to be three times stronger than its as‐grown counterpart under the same injection current, and the threshold voltage of the device is significantly reduced simultaneously. The increases in electron concentration and mobility of the ZnO layer resulting from the incorporation of hydrogen atoms into ZnO are considered to be responsible for the improved performance of the ZnO‐based light‐emitting diodes. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A new non‐parametric CUSUM mean chart
Authors: Yang Su‐Fen , Cheng Smiley W.
Published: December 2010

Not all data in practice came from a process with normal distribution. When the process distribution is non‐normal or unknown, the commonly used Shewhart control charts are not suitable. In this paper, a new non‐parametric CUSUM Mean Chart is proposed to monitor the possible small mean shifts in the process. The sampling properties of the new monitoring statistics are examined and the average run lengths of the proposed chart are examined. Two numerical examples are used to illustrate the proposed chart and compare with the two existing charts, assuming normality and Beta distribution, respectively. The CUSUM Mean Chart showed better detection ability than those two charts in monitoring and detecting small process mean shifts. Copyright © 2010 John Wiley & Sons, Ltd.
Wind speed parameter estimation from one‐month sample via Bayesian approach
Authors: Erto Pasquale , Lanzotti Antonio , Lepore Antonio
Published: December 2010

Site‐specific wind potential assessment shows difficulties mainly because it needs very long on‐site anemometric monitoring. This paper proposes to reduce the long‐term monitoring by exploiting other initial information about parameters to be estimated via MCMC (Markov chain Monte Carlo). The proposed Bayesian approach allows the integration of prior information (e.g. obtained from atlases, databases and/or fluid‐dynamic assessment) with sampling data, and furnishes effective and timely posterior information about Weibull parameters of the wind speed distribution. Real sampling data, collected from a southern Italian site, are analysed in order to illustrate the main features of the methodology. Moreover, the effectiveness of both the filtering strategy adopted to deal with the high correlation that usually characterizes the anemometric data, and the seasonal adjustment proposed to obtain a sample unbiased by seasonal effect is highlighted. The results of the application show that the proposed methodology fits the applicative needs very well. A bootstrap simulation remarks that the attained precision of the Bayesian estimates carried out from a one‐month sample is comparable to the maximum likelihood estimates obtained from an actual one‐year sample. Copyright © 2010 John Wiley & Sons, Ltd.
Role of 2‐oxo and 2‐thioxo modifications on the fragmentation reactions of the histidine radical cation
Authors: Lam Adrian K. Y. , Hutton Craig A. , O'Hair Richard A. J.
Published: December 2010

The fragmentation reactions of the radical cations, M.+, of histidine, 2‐oxo‐histidine and 2‐thioxo‐histidine were examined using a combination of experiments performed on a linear ion trap and density functional theory (DFT) calculations at the UB3‐LYP/6‐311++G(d,p) level of theory. Low‐energy collision‐induced dissociation (CID) on [CuII(terpy)(M)]2+ complexes, formed via electrospray ionisation, produced the radical cations in sufficient yield to examine their unimolecular chemistry via an additional stage of CID. The CID spectrum of the radical cation of histidine is dominated by loss of water with the next most abundant ion arising from the combined loss of H2O and CO. In contrast, the CID spectra of the radical cations of 2‐oxo‐histidine and 2‐thioxo‐histidine are dominated by the combined loss of CO2 and NHCH2. The observed differences are rationalised via DFT calculations which reveal that the barrier associated with loss of CO2 from the histidine radical cation is higher than that for loss of H2O. In contrast, the introduction of an oxygen or sulfur atom into the side chain of histidine results in a reversal of the order of these barrier heights, thus making CO2 loss the preferred pathway. Copyright © 2010 John Wiley & Sons, Ltd.
Identification of carbadox metabolites formed by liver microsomes from rats, pigs and chickens using high‐performance liquid chromatography combined with hybrid ion trap/time‐of‐flight mass spectrometry
Authors: Liu Zhao‐Ying , Tao Yan‐Fei , Chen Dong‐Mei , Wang Xu , Yuan Zong‐Hui
Published: December 2010

Carbadox (methyl‐3‐(2‐quinoxalinylmethylene)‐carbazate‐N1,N4‐dioxide) is a chemotherapeutic growth promoter added to feed for starter pigs. In this work, the metabolism of carbadox in rat, pig and chicken liver microsomes has been studied firstly. The incubation mixtures were then processed and analyzed for metabolites with a sensitive and reliable method based on high‐performance liquid chromatography combined with hybrid ion trap/time‐of‐flight mass spectrometry (LC/MS‐IT‐TOF). With the help of chromatographic behavior and accurate mass measurements, it is possible to rapidly and reliably characterize the metabolites of carbadox. The structural elucidations of these metabolites were performed by comparing the changes in the accurate molecular masses and fragment ions generated from precursor ions with those of parent drug. The present results showed that the metabolism of carbadox in liver microsomes had qualitative species‐difference. A total of seven metabolites were identified in rat liver microsomes. Five metabolites (Cb1–Cb3, Cb5, Cb7) were observed in pig and chicken liver microsomes. In addition, metabolite Cb6 was also detected in chicken liver microsomes. The peak areas of the metabolites in the three species are different. For the formations of Cb1, Cb2, Cb5 and Cb6, the rank order was rat>chicken>pig; Cb3; pig∼chicken>rat. Cb1, Cb2 and Cb3 have been previously reported, whereas the other four metabolites were novel. The N→O group reduction and hydroxylation followed by N→O group reduction were the main metabolic pathways for carbadox in the three species. Copyright © 2010 John Wiley & Sons, Ltd.
Robotic palliation for unresectable pancreatic cancer and distal cholangiocarcinoma
Authors: Buchs Nicolas C. , Addeo Pietro , Bianco Francesco M. , Elli Enrique F. , Ayloo Subhashini , Giulianotti Pier C.
Published: December 2010

Background

Optimizing quality of life is a major goal for patients with unresectable pancreatic cancer and distal cholangiocarcinoma. The aim of this study was to assess the value of robotic surgery for palliation in these patients.

Methods

Between May 2007 and January 2010, nine patients who presented with unresectable pancreatic cancer or distal cholangiocarcinoma at exploratory laparoscopy were included in this retrospective study.

Results

Eight hepaticojejunostomies, one choledochoduodenostomy and five gastrojejunostomies were performed robotically. Mean operative time was 236 ± 25 min. Median length of stay was 6 (range 4–10) days. There was no perioperative mortality. The morbidity rate was 22.2%. After a median follow‐up of 265 days, there were no other readmissions for problems related to the operation.

Conclusions

Robotic palliation in cases of unresectable pancreatic cancer or distal cholangiocarcinoma is feasible and effective. The use of robotics in palliative surgery offers low morbidity, short hospital stay and minimal readmissions. Copyright © 2010 John Wiley & Sons, Ltd.
Formation and tribological properties of two‐component ultrathin ionic liquid films on Si
Authors: Pu Jibin , Liu Xiufang , Wang Liping , Xue Qunji
Published: December 2010

Several single‐component and two‐component imidazolium ionic liquids (ILs) ultrathin films were formed on Si substrates by a dip‐coating and heat treatment process. The formation and surface properties of the films were analyzed by means of ellipsometric thickness measurement, X‐ray photoelectron spectra and atomic force microscope. The adhesive and nanotribological behaviors of the films were evaluated by a homemade colloidal probe. A ball‐on‐plate tribometer was used to test the microtribological performances of these films. As a result, the two‐component ILs ultrathin film containing 80% solid‐like ILs phase shows more homogenous surface morphologies and optimal micro/nano‐tribological properties as compared to single‐component ILs films, which is ascribed to a synergic effect between the steady solid‐like ILs phase as the backbone and the proper amount of flowable liquid‐like ILs phase. By studying the influence of various solid/liquid ILs ratios on tribological properties of the two‐component ILs films, we might find the way to design ILs films with excellent comprehensive tribological properties. Copyright © 2010 John Wiley & Sons, Ltd.
Experimental determination of the electron elastic backscattering probability and the surface excitation parameter for Si, Ni, Cu and Ag at 0.5 and 1 keV energies
Authors: Gergely G. , Gurban S. , Menyhard M. , Jablonski A. , Zemek J. , Goto K.
Published: December 2010

Electron spectra are generally presented in arbitrary units. The experimental elastic peak intensity Iespec(E) is determined by the elastic backscattering probability Ie(E) of electrons backscattered elastically within the solid angle of the spectrometer. The experimental elastic peak Iespec(E) is converted to Ie(E) backscattering probability using our new procedure based on the Goto ie(E) elastic backscattering current database. The elastic backscattering probability Ic(E) was calculated applying the EPESWIN software of Jablonski. Ie(E) < Ic(E) due to the surface losses of electrons, characterized by the surface excitation parameter Pse (SEP). Pse(E) was determined experimentally using the Goto database and the relationship of Tanuma. Our new procedure is applied to angular‐resolved (AREPES) spectra of Jablonski and Zemek presented in arbitrary units. In their AREPES experiments, the experimental elastic peak intensity Iespec = Ie(E, αd, ΔΩ) was measured at αd angle of detection (35–74°) with a small HSA, with ΔΩ solid angle. The experimental value at 42° $I_{e}(E, {\it{42}}\deg{\hbox{}}, {\Delta}\Omega)$ was converted to probability with the Goto database. It was corrected with a SEP parameter Pse, determined by trial and error method for Si, Ni, Cu and Ag for E = 0.5 and 1 keV primary energies. Copyright © 2010 John Wiley & Sons, Ltd.
Interfacial Studies for improving the adhesion of Cr/Al films on composites
Authors: Zhao Dong‐Cai , Xiao Geng‐Jie , Ren Ni , Ma Zhan‐Ji , Wu Sheng‐Hu
Published: December 2010

The composites, such as CFRP and GFRP, have been widely applied in spaceflight, for their low specific gravity, low cost, and additional structural stability. However, the high resistivity of the composites severely inhibits their further applications. Therefore, Cr/Al films with low resistivity and high adhesion were deposited on composites by cathodic arc technique. The films were characterized by pull test, Dektak 8 Stylus Profilometer, SEM, XPS, XRD and Z‐82 standard four probes. Results show that the aluminum film of fcc structure is compact and uniform, with resistivity as low as bulk Al. The adhesion between Cr buffer layer and composite substrate was greatly enhanced because of the formation of the chemical bonds, such as CrC, CrO and CrN, at the Cr/composite interface. Copyright © 2011 John Wiley & Sons, Ltd.
Patterned Polymer Carpets
Authors: Amin Ihsan , Steenackers Marin , Zhang Ning , Schubel René , Beyer André , Gölzhäuser Armin , Jordan Rainer
Published: December 2010

For the development of polymer carpets as active devices for micro‐ and nanotechnology, a control of the polymer carpet morphology and especially control of the stimulus responsive polymer brush is needed. Here, we report on the first example for the fabrication of patterned polymer carpets. On a two‐dimensional framework of fully crosslinked and chemically patterned nanosheets, polymer brushes of styrene and 4‐vinyl pyridine were grafted by self‐initiated surface photopolymerization and photografting (SIPGP). It was found that polymer grafting by SIPGP occurred over the entire nanosheets but with a preferred grafting on the amino functionalized nanosheet areas. This results in continuous polymer carpets with an intact nanosheet framework but with amplification of the chemical patterning into a three dimensional topography of the grafted polymer brush. In the case of negative patterned nanosheets, the patterned carpet could be prepared as freestanding ultrathin membranes. Furthermore, swelling experiments with poly(4‐vinyl pyridine) carpets showed that the patterns induces a directional buckling of the flexible polymer carpet. This may open the possibility of the development of micro‐ or nanoactuator devices with anisotropic responds upon environmental changes.
SubCollaboration: large‐scale group management in collaborative learning
Authors: Pardo Abelardo , Kloos Carlos Delgado
Published: December 2010

Computer‐supported collaborative learning is a paradigm that uses technology to support collaborative methods of instruction. When combining collaborative learning with the need to exchange documents between students and the teaching staff in a blended learning scenario, version control systems (VCSs) greatly simplify this collaboration. Furthermore, these tools need to be adopted in regular classes as they are used in industrial environments. But deploying a collaborative environment in which version control is used does not scale for large classes. This paper presents SubCollaboration, a platform that uses the VCS Subversion to manage a large number of work spaces in a collaborative learning environment. The tool maintains a reference workspace where teaching staff introduces new material that is then synchronized with the team repositories. Two case studies are presented showing that students easily learn the use of version control and its deployment in large classes is feasible. Copyright © 2010 John Wiley & Sons, Ltd.