bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and characterization of a novel composite based on hyperbranched polysilane and fullerene
Authors: Yu Jiang , Zhang Zhenghua , Ni Yu , Lu Yanbing , Xiong Yuanqin , Xu Weijian 
Published: April 2007

AbstractConjugated polymers doped with fullerenes have shown promising application in photovoltaic cells, in which photoinduced charge transfer takes place. Here, we report a novel composite that was prepared by in situ polymerization of σ‐conjugated hyperbranched polysilane in the presence of fullerene. Both of the hyperbranched polysilane and fullerene have 3D structures, which are propitious to preparing materials with interpenetrating structure. The resulting composite has good solubility in common organic solvents and the UV spectrum edge suggests a low bandgap. Photoluminescence quenching in the composite is shown by the PL spectra and is also observed from the fluorescence microscopy images, which may be ascribed to the PCT from the hyperbranched polysilane to the fullerene. The composite was also characterized by GPC, FTIR, NMR, XRD, and TGA. Through further discussion, there may be π‐π stacking between hyperbranched polysilane and fullerene, which enhances the photoinduced charge transfer. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Melting and degradation of nylon‐11 particles during HVOF combustion spraying
Authors: Ivosevic Milan , Cairncross Richard A. , Knight Richard 
Published: April 2007

AbstractNumerical predictions and experimental observations have been correlated to improve the qualitative understanding of the degree of thermal degradation occurring during the HVOF spray deposition of nylon‐11. Particle residence time (∼ 1 ms) in the HVOF jet was insufficient for significant decomposition of the nylon‐11, but was sufficient for noticeable discoloration (yellowing) of the particles of a powder with a mean particle size of 30 μm. Experimental observation showed this to be the case even though numerical predictions indicated that the temperature of a 30 μm diameter particle should be considerably higher than the upper degradation limit of nylon‐11. Initial thermal oxidation of nylon‐11 promotes the formation of carbon–carbon double bonds that strongly absorb in the visible spectrum even at concentrations of parts per million causing discoloration of the nylon. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Proton conductivity and methanol permeability of sulfonated poly(vinyl alcohol) membranes modified by using sulfoacetic acid and poly(acrylic acid)
Authors: Seeponkai N. , Wootthikanokkhan J. 
Published: April 2007

AbstractSulfonated poly(vinyl alcohol) (PVA) for use as a proton conductive membrane in a direct methanol fuel cell (DMFC) was prepared by reacting the PVA with sulfoacetic acid and poly(acrylic acid). The effects of the amount of sulfoacetic acid and poly(acrylic acid) on proton conductivity, methanol permeability, water uptake, and ion exchange capacity (IEC) of the sulfonated PVA membranes were investigated by using impedance analysis, gas chromatography, gravimetric analysis, and titration techniques, respectively. The water uptake of the membranes decreased with the amount of the sulfoacetic acid and the amount of poly(acrylic acid) used. The proton conductivity and the IEC values of the membranes initially increased and then decreased with the amount of the sulfoacetic acid. The methanol permeability of the sulfonated PVA membranes decreased continuously with the amount of the sulfoacetic acid. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Thermal oxidation of metallocene‐catalyzed poly(ethylene octene) by a rheological method
Authors: Yang Kai , Yu Wei , Zhou Chixing 
Published: April 2007

AbstractThe thermal oxidation of a metallocene‐catalyzed poly(ethylene octene) (POE) melt was studied by a dynamic rheological method. Furthermore, to prove the effect of oxygen on the thermal oxidation of POE, cyclic samples, which consisted of virgin POE in the outer circle and POE with antioxidant inside, were made. The results showed that a thermal‐oxidation‐induced crosslinking reaction occurred in the POE melt at a high temperature. The amount of the antioxidant determined the thermal oxidation of POE when the antioxidant was added, and the diffusion of oxygen controlled the thermal oxidation of POE without the antioxidant. In addition, Fourier transform infrared and gel content characterization confirmed that the crosslinking occurred and that carbonyl groups formed in the reaction. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Fluoroquinolon‐type antibiotic treatment of PAN and cationic‐dyeable PET fibers for infection resistant materials
Authors: Choi Hyung‐Min 
Published: April 2007

AbstractCommercial poly(acrylonitrile) (PAN) and cationic‐dyeable poly(ethylene terephthalate) (PET) were dyed with a fluoroquinolon‐type antibiotic, ciprofloxacin (Cipro), to develop infection resistant biomedical materials. Regular PET fiber was also treated as a comparison purpose. Experimental parameters examined were different dyeing temperatures, times, and pHs. To investigate effect of hydrolysis on Cipro sorption, the fibers were hydrolyzed by 1% NaOH for 1 or 2 h at 85°C and 100°C. Regardless of pH conditions, both PAN fibers (Orlon and Acrilan) sorbed high level of Cipro at 100°C for 3.5 h, but zone of inhibition (ZOI) value reached zero at 4 h of wash time. Contrarily, the presence of additional functional groups in PAN and cationic‐dyeable PET obtained by hydrolysis not only considerably enhanced sorption of Cipro but also provided much better sustained release, indicated by high ZOI value at 24 h of wash time. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Effect of cationization reagents on the matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrum of Chinese gallotannins
Authors: Xiang Ping , Lin Yiming , Lin Peng , Xiang Cheng , Yang Zhiwei , Lu Zhongmin 
Published: April 2007

AbstractIn this study, Chinese gallotannins were characterized by MALDI‐TOF MS, and effects of cationization reagents on the quality of spectra were investigated. The trideca‐ and tetradeca‐galloyl glucoses were observed in Chinese gallotannins, which could not be detected in earlier studies. When Cs+ was used as the cationization reagent, Chinese gallotannins gave a relatively simple MALDI‐TOF spectrum, three series of quasimolecular ions [M + Cs]+, [M + 2Cs–H]+, and [M + 3Cs–2H]+ and a series of metastable ion peaks with minimum abundance were detected. Selection of Na+ as the cationization reagent, additional three series of ion peaks including two patterns from the fragmentation and complex 2M adducts [2M + Na]+ can be distinguished. In the case of no deionization or addition of cationization reagent to the analyte/matrix, naturally abundant Na+ and K+ as the cationization reagent, [M + Na]+ and [M + K]+ molecular ions both appeared in the complicated spectrum. Therefore, we conclude that cationization reagents affect the MALDI‐TOF MS spectrum of Chinese gallotannins significantly. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
In VitroandIn Vivopharmacokinetic studies of bulaquine (analogue of primaquine), a novel antirelapse antimalarial, in rat, rabbit and monkey—highlighting species similarities and differences
Authors: Mehrotra Nitin , Lal Jawahar , Puri Sunil Kumar , Madhusudanan Kunnath P. , Gupta Ram Chandra 
Published: April 2007

AbstractBulaquine (BQ) is a potent antirelapse antimalarial developed by CDRI, India. Bulaquine was rapidly absorbed in rats and rabbits with no distinct absorption phase while in monkeys a variable irregular absorption profile was observed. BQ was extensively converted to primaquine (PQ) after oral administration and the conversion was maximum in rats and minimum in rabbits, which is possibly due to the species difference. Clearance was higher in rats (3.2 l/h/kg) than in rabbits and monkeys (1.2 l/h/kg) and it was found be negligibly excreted in rat urine and feces. The elimination half‐life in rats and rabbits was comparable after both oral and i.v. administration (∼1.2 h). In all three species, PQ was resident in the body for a period longer than BQ. PQ, being the major active metabolite of BQ, might be responsible for the extended therapeutic effect of BQ. The oral bioavailability of BQ was 3.12%, 5.3% and 12% in rats, rabbits and monkeys, respectively, which could be mainly due to the high instability of BQ at acidic pH as demonstrated from a simulated gastric fluid stability study. Protein binding in various species was in the range 50–65% while the partition coefficient between RBCs and plasma (Krbc/pl) was between 0.75 and 1, indicating significant RBC uptake. Copyright © 2007 John Wiley & Sons, Ltd.
Unpacking perceived control in risk perception: the mediating role of anticipated regret
Authors: Nordgren Loran F. , van der Pligt Joop , van Harreveld Frenk 
Published: April 2007

AbstractPerception of control has been a fundamental construct in research on risk‐taking behavior. It has been shown, for example, that people tend to underestimate risks that are under their control. Despite its importance, surprisingly, little attention has been paid to what is actually meant by control. In three studies, we argue that the common conceptualization of perceived control is too broad as it fails to distinguish between two distinct aspects of control ‘command over exposure to the risk itself (volition)’ and ‘command over the outcome (control)’. Thus, whether the risk is imposed or freely chosen likely differs from, and has different consequences for, the ability to exert influence over a risky behavior, once it has been initiated. Using a wide variety of risk behaviors (e.g., ecstasy use, unsafe sex), we demonstrate that volition and control exert opposing influence on risk perception: control decreases perceived risk while volition increases perceived risk. This latter prediction is counterintuitive and is explained in terms of the mediating role of anticipated regret: voluntary appraisals elicit anticipated regret, which, in turn, increases perceived risk. This work highlights the dynamic relationship between risk characteristics and anticipated emotion in guiding the perception of risk. Copyright © 2007 John Wiley & Sons, Ltd.
Stoichiometry of biological nitrogen transformations in wetlands and other ecosystems
Authors: Zhou Shaoqi 
Published: April 2007

AbstractThe stoichiometric equations of ammonification, nitrification and denitrification have demonstrated that the nitrogen cycle in nature is rather complicated. The mechanisms of biological nitrogen transformations are very important for analysis, design, operation and optimal control of natural ecosystems or engineered systems for nitrogen removal, and accurate stoichiometric equations can help in the maintenance of these environments. In this study, the new stoichiometric equations of intermediate nitrification, and heterotrophic and autotrophic denitrification with sulfur as the electron donor have been developed and discussed. The parameter values of fs (the fraction of electron donor coupled to cell synthesis) in stoichiometric equations of nitrification and denitrification are calculated according to experimental results implied in previously reported stoichiometric equations. Some new stoichiometric relationships of nitrification and denitrification, such as the O2 demand for nitrifications, chemical oxygen demand/N ratios and the yield coefficients for denitrifications have been established. The pathway steps of nitrification and denitrification have been discussed.
Putting microbes to work: Dairy fermentation, cell factories and bioactive peptides. Part II: Bioactive peptide functions
Authors: Hayes Maria , Stanton Catherine , Fitzgerald Gerald F. , Ross R. Paul 
Published: April 2007

AbstractA variety of milk‐derived biologically active peptides have been shown to exert both functional and physiological roles in vitro and in vivo, and because of this are of particular interest for food science and nutrition applications. Biological activities associated with such peptides include immunomodulatory, antibacterial, anti‐hypertensive and opioid‐like properties. Milk proteins are recognized as a primary source of bioactive peptides, which can be encrypted within the amino acid sequence of dairy proteins, requiring proteolysis for release and activation. Fermentation of milk proteins using the proteolytic systems of lactic acid bacteria is an attractive approach for generation of functional foods enriched in bioactive peptides given the low cost and positive nutritional image associated with fermented milk drinks and yoghurt. In Part II of this review, we focus on examples of milk‐derived bioactive peptides and their associated health benefits, to illustrate the potential of this area for the design and improvement of future functional foods.
Insulin structure and function
Authors: Mayer John P. , Zhang Faming , DiMarchi Richard D. 
Published: April 2007

AbstractThroughout much of the last century insulin served a central role in the advancement of peptide chemistry, pharmacology, cell signaling and structural biology. These discoveries have provided a steadily improved quantity and quality of life for those afflicted with diabetes. The collective work serves as a foundation for the development of insulin analogs and mimetics capable of providing more tailored therapy. Advancements in patient care have been paced by breakthroughs in core technologies, such as semisynthesis, high performance chromatography, rDNA‐biosynthesis and formulation sciences. How the structural and conformational dynamics of this endocrine hormone elicit its biological response remains a vigorous area of study. Numerous insulin analogs have served to coordinate structural biology and biochemical signaling to provide a first level understanding of insulin action. The introduction of broad chemical diversity to the study of insulin has been limited by the inefficiency in total chemical synthesis, and the inherent limitations in rDNA‐biosynthesis and semisynthetic approaches. The goals of continued investigation remain the delivery of insulin therapy where glycemic control is more precise and hypoglycemic liability is minimized. Additional objectives for medicinal chemists are the identification of superagonists and insulins more suitable for non‐injectable delivery. The historical advancements in the synthesis of insulin analogs by multiple methods is reviewed with the specific structural elements of critical importance being highlighted. The functional refinement of this hormone as directed to improved patient care with insulin analogs of more precise pharmacology is reported. © 2007 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 88: 687–713, 2007.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Facile production of mono‐substituted urea side chains in solid phase peptide synthesis
Authors: Diss Maria L. , Kennan Alan J. 
Published: April 2007

AbstractA method is reported for the straightforward generation of urea‐containing peptides during Boc solid phase peptide synthesis. Primary amine side chains are converted to mono‐alkyl ureas in two steps via an intermediate p‐nitrophenyl carbamate. Use of p‐methoxybenzyl amine as an ammonia equivalent affords mono‐alkyl final products from standard resin cleavage methods, without the need for additional steps. The reaction is highly efficient and applicable to variable length side chains and peptides. © 2007 Wiley Periodicals, Inc. Biopolymers 86: 276–281, 2007.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Strip-track revascularization after stripping of the great saphenous vein
Authors: Munasinghe A , Smith C , Kianifard B , Price B A , Holdstock J M , Whiteley M S 
Published: April 2007

Abstract

Background
Varicose veins that recur after standard high tie and strip are often associated with venous reflux in the thigh, as shown by duplex ultrasonography. The aim of this study was to look for evidence of revascularization in the strip track after great saphenous vein (GSV) stripping.

Methods
A consecutive series of patients with duplex-proven great saphenous varicose veins underwent saphenofemoral ligation with intraoperative confirmation of successful stripping. Duplex ultrasonography was performed 1 week and 1 year after surgery. The presence and extent of haematoma was noted, as was any venous reflux within the strip track.

Results
At 1 year, four (6 per cent) of 70 patients had complete revascularization of the strip track and 12 (17 per cent) had partial revascularization, all with duplex-proven reflux. Partial revascularization was in the distal third of the track in six legs (9 per cent of the 70 patients), in the distal half in five (7 per cent) and was almost complete in one leg (1 per cent). All patients with revascularization had a significant strip-track haematoma at 1 week after surgery.

Conclusion
Revascularization of the GSV strip track after stripping was found in 23 per cent of patients after 1 year; all of these had a postoperative haematoma in the track.
Desmoid tumours in patients with familial adenomatous polyposis and desmoid region adenomatous polyposis coli mutations
Authors: Speake D , Evans D G , Lalloo F , Scott N A , Hill J 
Published: April 2007

Abstract

Background
The aim of this study was to determine the proportion of patients with familial adenomatous polyposis (FAP) who had mutations in the desmoid region of the adenomatous polyposis coli (APC) gene that phenotypically expresses desmoid disease, and to determine the role for surgery in these patients.

Methods
Data from the North West Region FAP database and case notes were analysed retrospectively.

Results
Of 363 patients with FAP, 47 from ten families had APC mutations in the desmoid region 3′ to codon 1399. Of 22 patients undergoing surgery, 16 developed desmoids, and of these 12 had mesenteric desmoid disease. Complications from mesenteric desmoids were death (two patients), enterectomy (three), local resection (three), fistula (one), cholangitis and local resection (one), bowel obstruction (one) and bowel and ureteric obstruction (one). Preoperative polyp burden ranged from 0 to 100 in eight patients (median age 24·5 (range 16–39) years) and more than 100 in seven (median age 39 (range 31–64) years). One patient had no record of polyp burden.

Conclusion
In individuals with 3′ APC mutations, abdominal surgery is associated with a 65 per cent risk of developing mesenteric desmoids. An alternative strategy might be to attempt to manage the polyps endoscopically.
Antioxidants modulate the IL‐6 induced inhibition of negative acute‐phase protein secretion in HepG2 cells
Authors: El‐Saadany Mohamed A. , Rawel Harshadrai M. , Raila Jens , El‐Dashloty Mohamed S. , Schweigert Florian J. 
Published: April 2007

AbstractDespite increasing evidence on the potential of dietary antioxidants in modulating the etiology of certain chronic diseases such as cancer and cardiovascular diseases, little is known about their beneficial role in acute‐phase responses and inflammatory diseases. From this viewpoint the aim of this study was to investigate the effect of selected dietary antioxidants in modulating the secretion of negative acute‐phase proteins caused by interleukin‐6 (IL‐6) in HepG2 cells. Cells were first stimulated with a fixed dose of IL‐6 for 24 h then incubated for a further 8 h with varying concentrations of eight antioxidants, α‐lipoic acid (LA), (−)‐epicatechin (EC), (−)‐epicatechin gallate (ECG), (−)‐epigallocatechin (EGC), (−)‐epigallocatechin gallate (EGCG), α‐tocopherol (TOC), ascorbic acid (AA) and N‐acetylcysteine (NAC). The culture supernatants were assayed for transthyretin (TTR) and retinol binding protein (RBP) using ELISA. The data revealed that IL‐6 significantly reduced TTR and RBP secretion compared with the basal production. All tested antioxidants attenuate the reduction in TTR and RPB levels. The strongest effects were achieved with the highest concentration of each antioxidant. The order of effect were LA > EGCG > ECG > TOC > EGC > EC > NAC > AA. In conclusion, these results provide evidence that the dietary antioxidants can play a fundamental role in inflammatory processes. Copyright © 2007 John Wiley & Sons, Ltd.
Establishment of association of an Mg2+‐dependent endonuclease with the rat liver nuclear matrix in cryonecrosis
Authors: Grdović Nevena , Mihailović Mirjana , Vidaković Melita , Dinić Svetlana , Uskoković Aleksandra , Martinović Vesna , Arambašić Jelena , Grigorov Ilijana , Ivanović‐Matić Svetlana , Bogojević Desanka , Petrović Miodrag , Poznanović Goran 
Published: April 2007

AbstractPreviously, we characterized the endonucleolytic activity of the nuclear matrix prepared from rat liver cryopreserved in liquid nitrogen. The enzymic activity was attributed to a 23 kDa, Mg2+‐dependent and sequence non‐specific endonuclease (p23) stably associated with the nuclear matrix. Here we show that p23 was absent from the nuclear matrix prepared from fresh liver. Instead, both ex vivo (cryopreservation), as well as in vivo‐induced necrosis by repeated freezing/thawing of liver tissue in an anaesthetized rat, promoted the activation and translocation of p23 to the nuclear matrix. Considering that ex vivo and in vivo freezing/thawing of the liver were accompanied by morphological (nuclear compaction) and biochemical events (increased LDH activity, disorderly genomic DNA degradation, absence of lamin proteolysis, appearance of 62 and 50 kDa necrotic cleavage products of PARP‐1) commonly observed during necrosis, and because the association of p23 with the nuclear matrix was saturable, reflecting the existence of a limited number of distinct high affinity sites on the nuclear matrix for p23, we concluded that the activation of the nuclear matrix‐associated endonuclease p23 is a feature of liver cryonecrosis. Although cryonecrosis represents a typical example of acute cell damage, our results suggest that it is realized by ordered molecular events. Copyright © 2007 John Wiley & Sons, Ltd.