bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microbial response to environmental gradients in a ceramic‐based diffusion system
Authors: Wolfaardt G.M. , Hendry M.J. , Birkham T. , Bressel A. , Gardner M.N. , Sousa A.J. , Korber D.R. , Pilaski M. 
Published: January 2008

AbstractA solid, porous matrix was used to establish steady‐state concentration profiles upon which microbial responses to concentration gradients of nutrients or antimicrobial agents could be quantified. This technique relies on the development of spatially defined concentration gradients across a ceramic plate resulting from the diffusion of solutes through the porous ceramic matrix. A two‐dimensional, finite‐element numerical transport model was used to predict the establishment of concentration profiles, after which concentration profiles of conservative tracers were quantified fluorometrically and chemically at the solid–liquid interface to verify the simulated profiles. Microbial growth responses to nutrient, hypochloride, and antimicrobial concentration gradients were then quantified using epifluorescent or scanning confocal laser microscopy. The observed microbial response verified the establishment and maintenance of stable concentration gradients along the solid–liquid interface. These results indicate the ceramic diffusion system has potential for the isolation of heterogeneous microbial communities as well as for testing the efficacy of antimicrobial agents. In addition, the durability of the solid matrix allowed long‐term investigations, making this approach preferable to conventional gel‐stabilized systems that are impeded by erosion as well as expansion or shrinkage of the gel. Biotechnol. Bioeng. 2008;100: 141–149. © 2008 Wiley Periodicals, Inc.
Systematic review and meta-analysis of randomized controlled trials comparing stapled haemorrhoidopexy with conventional haemorrhoidectomy
Authors: Shao W-J , Li G-C H , Zhang Z H-K , Yang B-L , Sun G-D , Chen Y-Q 
Published: January 2008

Abstract

Background
This paper compares stapled haemorrhoidopexy with conventional haemorrhoidectomy for the treatment of haemorrhoids.

Methods
An electronic literature search was undertaken to identify primary studies and systematic reviews. Results on efficacy and safety were analysed. A meta-analysis was conducted to examine long-term outcomes.

Results
Twenty-nine randomized clinical trials recruiting 2056 patients were identified. Meta-analysis showed that stapled haemorrhoidopexy was less painful than conventional haemorrhoidectomy. Stapled haemorrhoidopexy required a shorter inpatient stay (weighted mean difference (WMD) − 0·95 (95 per cent confidence interval (c.i.) − 1·32 to − 0·59) days; P &lt; 0·001) and operating time (WMD − 11·42 (95 per cent c.i. − 18·26 to − 4·59) min; P = 0·001). It was also associated with a faster return to normal activities (WMD − 11·75 (95 per cent c.i. − 21·42 to − 2·08) days; P = 0·017). No significant difference was noted between the two techniques in terms of the total incidence of complications. Stapled haemorrhoidopexy was associated with a higher rate of recurrent disease (relative risk 2·29 (95 per cent c.i. 1·57 to 3·33); P &lt; 0·001).

Conclusion
Stapled haemorrhoidopexy offers some short-term benefits over conventional operation but the total complication rates are similar for both techniques. Stapled haemorrhoidopexy is associated with a higher rate of recurrent disease.
Monomer Formation and Function of p‐Hydroxybenzoate Hydroxylase in Reverse Micelles and in Dimethylsulfoxide/Water Mixtures
Authors: Kudryashova Elena V. , Visser Antonie J. W. G. , van Berkel Willem J. H. 
Published: January 2008

AbstractIt has previously been postulated that the dimeric form of the flavoprotein p‐hydroxybenzoate hydroxylase (PHBH) is important for catalysis. Here it is demonstrated that the monomeric form of PHBH is active. In a water/AOT/isooctane reverse micellar system, the function of the monomeric and dimeric forms of PHBH could be observed separately by varying the size of the micelles. A considerable decrease in the KM value for p‐hydroxybenzoate (POHB) was found for monomeric PHBH, accompanied by a 1.5‐fold decrease in enzymatic activity. The same tendency was observed when monomers of PHBH were formed by adding DMSO to the buffer. The FAD in PHBH and PHBH labeled with the fluorescence dye Alexa488 was investigated by time‐resolved fluorescence anisotropy to observe monomer formation in water/DMSO mixtures. Monomer formation of PHBH occurred gradually with increasing DMSO content in the mixture. Pure PHBH monomers were detected at DMSO concentrations of 30 % (v/v) and higher.
A guide to characterizing heat release rate measurement uncertainty for full‐scale fire tests
Authors: Bryant Rodney A. , Mulholland George W. 
Published: January 2008

AbstractAccurate heat release rate measurements provide essential information to defining the fire safety characteristics of products. The size, complexity, and cost of full‐scale fire tests make achieving accurate and quantitative results a serious challenge. A detailed uncertainty analysis of a large‐scale heat release rate measurement facility is presented as a guide to the process of estimating the uncertainty of similar facilities. Quantitative heat release rate measurements of full‐scale fires up to 2.7 MW were conducted using the principle of oxygen consumption calorimetry. Uncertainty estimates were also computed for the heat input measurements from a well‐controlled natural gas burner. The measurements of heat input and heat release rate were performed independently, and the discrepancy between the two was well within the uncertainty limits. The propagation of uncertainty was performed at the level of voltage and temperature measurements, which avoided using mutually dependent measurement parameters. Reasons for the significant contribution to the combined uncertainty from the oxygen concentration and exhaust flow measurements are demonstrated. Also presented is a first‐order effort to account for the uncertainty due to factors in full‐scale fire tests such as operator error and environmental influences that are not modeled by the heat release rate equation. Published in 2008 by John Wiley & Sons, Ltd.
A better bound for the cop number of general graphs
Authors: Chiniforooshan Ehsan 
Published: January 2008

AbstractIn this note, we prove that the cop number of any n‐vertex graph G, denoted by ${{c}}({{G}})$, is at most ${{O}}\big({{{n}}\over {{\rm lg}} {{n}}}\big)$. Meyniel conjectured ${{c}}({{G}})={{O}}(\sqrt{{{n}}})$. It appears that the best previously known sublinear upper‐bound is due to Frankl, who proved ${{c}}({{G}})\leq ({{1}}+ {{o}}({{1}})){{{n}}{{\rm lg}}{{\rm lg}} {{n}}\over {{\rm lg}} {{n}}}$. © 2008 Wiley Periodicals, Inc. J Graph Theory 58: 45–48, 2008
Activated K‐RAS increases polyamine uptake in human colon cancer cells through modulation of caveolar endocytosis
Authors: Roy Upal K. Basu , Rial Nathaniel S. , Kachel Karen L. , Gerner Eugene W. 
Published: January 2008

AbstractEndocytic pathways have been implicated in polyamine transport in mammalian cells, but specific mechanisms have not been described. We have shown that expression of a dominant negative (DN) form of the GTPase Dynamin, but not Eps15, diminished polyamine uptake in colon cancer cells indicating a caveolar and nonclathrin uptake mode. Polyamines co‐sediment with lipid raft/caveolin‐1 rich fractions, of the plasma membrane in a sucrose density gradient. Knock down of caveolin‐1 significantly increased polyamine uptake. Conversely, ectopic expression of this protein resulted in diminished polyamine uptake. We also found that presence of an activated K‐RAS oncogene significantly increased polyamine uptake by colon cancer cells. This effect is through an increase in caveolin‐1 phosphorylation at tyrosine residue 14. Caveolin‐1 is a negative regulator of caveolar endocytosis and phosphorylation in a K‐RAS dependent manner leads to an increase in caveolar endocytosis. In cells expressing wild type K‐RAS, addition of exogenous uPA was sufficient to stimulate caveolar endocytosis of polyamines. This effect was abrogated by the addition of a SRC kinase inhibitor. These data indicate that polyamine transport follows a dynamin‐dependent and clathrin‐independent endocytic uptake route, and this route is positively regulated by the oncogenic expression of K‐RAS in a caveolin‐1 dependent manner. © 2008 Wiley‐Liss, Inc.
Security and privacy for the next wireless generation
Authors: Urien Pascal , Pujolle Guy 
Published: January 2008

AbstractThis paper presents research performed during the last 4 years (2003–2007), in order to design applications (usually referred asEAP smart cards) which enhance security and privacy in emerging WLAN infrastructures. It introduces smart cards ensuring strong authentication in IP networks, according to the extensible authentication protocol (EAP). An open software implementation has been released for Java cards. These devices may be deployed on clients' terminals (such as IEEE 802.1X supplicants) or in RADIUS servers. Experimental results, observed with platforms including win32 computers, Wi‐Fi access points and smart card enabled RADIUS servers, demonstrate that this approach is realistic, even with today's smart cards. Copyright © 2008 John Wiley & Sons, Ltd.
Surfactant‐free synthesis of amphiphilic copolymer of poly(styrene‐co‐acrylamide) in aqueous emulsion with the assistance of ultrasound
Authors: Yan Lifeng , Ji Jing , Xie Dinghai , Li Wan , Zhang Guangzhao 
Published: January 2008

AbstractThe hydrophilic monomer acrylamide (AM) and hydrophobic monomer styrene (St) have been directly copolymerized in a surfactant‐free aqueous emulsion with the assistance of powerful ultrasound. Fourier Transform Infrared spectrocopy (FT‐IR), nuclear magnetic resonance (NMR), and differential scanning calorimetry (DSC) measurements revealed that copolymers of AM and St were obtained. Elemental analysis was used to calculate the composition of the copolymer. Size exclusion chromatography (SEC) measurement showed that the molecular weight (Mw) of the copolymer is 1.86 × 105 g/mol and the polydispersity index (PDI( = 2.31. The self‐assembly behavior in different solvents was investigated utilizing laser light scattering (LLS), atomic force microscopy (AFM), and transmission electron microscopy (TEM); the copolymer film showed amphiphilicity, as measured by contact angle goniometry. Copyright © 2008 John Wiley & Sons, Ltd.
Preparation of new membranes based on sulfonated aromatic copolyimides
Authors: Rabiee Ahmad , Mehdipour‐Ataei Shahram , Banihashemi Ahmad , Yeganeh Hamid 
Published: January 2008

AbstractNew sulfonated aromatic copolyimides with controlled degree of sulfonation were prepared via polycondensation reactions of a sulfonated diamine and two unsulfonated diamines with 1,4,5,8‐naphthalene tetracarboxylic dianhydride (NDA). The sulfonated diamine 3,3′‐disulfonic acid‐ bis[4‐(5‐amino‐1‐naphthoxy)phenyl]sulfone (DANPS) was synthesized through nucleophilic substitution reaction of 5‐amino‐1‐naphthol with disodium‐3,3′‐disulfonate‐4,4′‐dichlorodiphenysulfone (SDCDPS) and subsequent acidification. Two unsulfonated diamines 4,4′‐(5‐amino‐1‐naphthoxy)diphenylsulfone (ANDS) and 4,4′‐(4‐aminophenoxy)diphenylsulfone (APDS) were prepared by nucleophilic reaction of 5‐amino‐1‐naphthol and 4‐aminophenol with 4,4′‐dichlorodiphenylsulfone in the presence of potassium carbonate, respectively. After characterization of the monomers and polymers with common methods, the physical properties of the polymers including thermal behavior and stability, viscosity, molecular weight, and ion exchange capacity (IEC) were studied. The polymers showed high thermal stability and ion exchange capacity which were the basic requirements for application as fuel cell membranes. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis and characterization of fluorescent starch using fluorescein as fluorophore: potential polymeric temperature/pH indicators
Authors: Guan Xiaolin , Su Zhixing 
Published: January 2008

AbstractA convenient method for attaching fluorescein (via its epoxy derivate) to natural starch and its temperature/pH‐sensitive qualities of fluorescence were investigated. 3‐epoxypropoxy fluorescein (EPF) was first synthesized through the reaction between fluorescein and epichlorohydrin, and starch‐bearing fluorescein (ST‐EPF) was prepared via ring‐opening reaction with EPF in dimethyl sulfoxide (DMSO) solution, in the presence of NaH as a catalyst. Both of them were characterized by the methods of 1H NMR, MS, IR, XRD, UV–Vis, and luminescence spectra, respectively. The chemiluminescent and photophysical behaviors of the dye fluorescein derivative and the polymer‐containing fluorescein were studied. The results indicated that ST‐EPF could still provide temperature and pH sensitivity similar to that of fluorescein and could achieve better long‐term stability and fast equilibrium response. ST‐EPF had an excellent linear response between relative fluorescence intensity and temperature in the range of 0–60°C and a nonlinear relationship between relative fluorescence intensity and pH in the wide range of 0.0–12.0, and so it has promise as an optical transducer for temperature and pH value determinations. Copyright © 2008 John Wiley & Sons, Ltd.
Thermal properties and combustion behaviors of UV‐cured phosphate triacrylate/star poly(urethane acrylate) oligomer blends
Authors: Chen Xilei , Hu Yuan , Song Lei , Xing Weiyi 
Published: January 2008

AbstractA series of UV‐curable intumescent flame retardant resins was obtained by blending phosphate triacrylate (TAEP) in certain ratios with star poly(urethane acrylate) (SPUA) oligomer. The flammability of the cured films was characterized by limited oxygen index (LOI), UL 94, and the cone calorimeter. The results showed that the cured TAEP/SPUA samples greatly expanded while burning. A distinct synergistic effect was found between TAEP and SPUA. TAEP2 sample showed the highest LOI value (41) among all resins. The cone calorimeter results showed that the peak heat release rates and carbon monoxide yield decreased to the approximate level. The degradation was monitored by thermogravimetric analysis and real‐time Fourier transform infrared spectroscopy. A degradation mechanism is suggested in which the phosphate group in TAEP first degraded to form poly(phosphoric acid)s, which further catalyzed the degradation of the material to form char with emission of carbon dioxide and nitrogen volatiles from SPUA, leading to the formation of expanding char. The morphologic structures of crusts of the formed chars were observed by scanning electron microscopy, demonstrating the synergistic effect between TAEP and SPUA. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis of melamine‐formaldehyde polycondensates as the thermal stabilizer of polyoxymethylene through ultrasonic irradiation
Authors: Zhao Xiaowen , Ye Lin , Hu Youliang 
Published: January 2008

AbstractMelamine (MA), as the formaldehyde (FA) absorbent of polyoxymethylene (POM), was polymerically modified by a condensation reaction with FA to form the melamine‐formaldehyde (MF) polycondensates with high molecular weight and comparatively high processing thermal stability. Ultrasonic irradiation was used for the synthesis, and ultrafine, crosslinked, and thermally stable MF polycondensates were obtained. The synthetic technique was discussed, and the thermal stabilization and nucleation effects of MF on POM were studied by the measurements of isothermal weight loss, balance torque, analysis of the formaldehyde emission amounts (FEAs), multiple extrusions, polarized light microscopy (PLM), isothermal and non‐isothermal differential scanning calorimetry (DSC), and scanning electron microscopy (SEM), which indicated that the thermal stability and the crystallization performance of POM was greatly enhanced by using MF as a thermal stabilizer and nucleation agent. The MF prepared using ultrasonic irradiation can improve the mechanical properties of POM more effectively compared with that prepared with normal mechanical stirring. Copyright © 2008 John Wiley & Sons, Ltd.
Preparation and adsorption of novel cellulosic fibers modified by β‐cyclodextrin
Authors: Xia Youyi , Wan Junmin 
Published: January 2008

AbstractNovel cellulosic fibers modified by β‐cyclodextrin (CFEC) were prepared for adsorption for heavy metal ions like copper (II) and organic dye like neutral red from their aqueous solutions. The modified cellulosic fibers gave higher copper ion adsorption, and showed copper ion uptake values of 6.24 mg/g at 293°C, as against no adsorption for unmodified cellulosic fibers. Adsorption isotherm model indicated the adsorption of the novel modified fibers for heavy metal ions best fitted for Langmiur model. The adsorption was an exothermic reaction, and the reaction caloric was 6.295 kJ/mol. Copper ions could form a 7:4 complex with β‐cyclodextrin (β‐CD). The novel modified cellulosic fibers could also form inclusion complexes with neutral red via β‐CD molecules. In addition, it was found that the novel modified cellulosic fibers had nearly the same mechanical and thermal properties as the unmodified cellulosic fibers because the modification did not destroy the main chain of cellulose molecules. Copyright © 2008 John Wiley & Sons, Ltd.
Are protein complexes made of cores, modules and attachments?
Authors: Pang Chi Nam Ignatius , Krycer James Robert , Lek Angela , Wilkins Marc Ronald 
Published: January 2008

AbstractIt has recently been proposed by Gavin et al. (Nature 2006, 440, 631–636) that protein complexes in the cell exist in different forms. The proteins within each complex were proposed to exist as three different classes, being core, module or attachment proteins. This study investigates whether the core–module–attachment classification of proteins within each complex is supported by other high‐throughput protein data. Core proteins were found to have lower abundance, and shorter half‐life as compared to attachment proteins, whilst the abundance and half‐life of core and module proteins were similar. When the cell was perturbed, core proteins had smaller changes in abundance as compared to module and attachment proteins. Comparisons between six different pairwise interaction types of core, module and attachment proteins within a complex showed interaction types involving core or module proteins were more likely to be mediated by domain–domain interactions (DDIs) than interaction types involving attachment proteins. Interaction types that involve attachment proteins had a relatively higher ratio of abundance and ratio of half‐life. So we conclude that, the core, module and attachment model of protein complexes is supported by data from these proteomic scale datasets, and describe a model for a typical protein complex that considers the above results.
Modelling the light induced metastable effects in amorphous silicon
Authors: Munyeme G. , Chinyama G. K. , Zeman M. , Schropp R. I. , van der Weg W. F. 
Published: January 2008

AbstractWe present results of computer simulations of the light induced degradation of amorphous silicon solar cells. It is now well established that when amorphous silicon is illuminated the density of dangling bond states increases. Dangling bond states produce amphoteric electronic mid‐gap states which act as efficient charge trapping and recombination centres. The increase in dangling bond states causes a decrease in the performance of amorphous silicon solar cells. To show this effect, a modelling approach has been developed which uses the density of localised states with exponentially increasing band‐tails and dangling bond defect states distribution chosen according to the defect pool model. The calculation of the evolution of dangling bond state density during illumination has been achieved through a dynamic scaling relation derived from a defect creation model. The approach considers the amphoteric nature of the dangling bond state and thus accounts for the contributions of the different charge states of the dangling bond during the degradation process. This paper attempts to describe the simulation approach which calculates the defect density as a function of energy, position in the solar cell and illumination time. In excellent agreement with other workers, our simulation results show that the increase in the density of neutral dangling bond states during illumination is higher than of the charged states. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electron transport properties of indium oxide – indium nitride metal‐oxide‐semiconductor heterostructures
Authors: Lebedev V. , Wang Ch. Y. , Hauguth S. , Polyakov V. , Schwierz F. , Cimalla V. , Kups T. , Morales F. M. , Lozano J. G. , González D. , Himmerlich M. , Schaefer J. A. , Krischok S. , Ambacher O. 
Published: January 2008

AbstractThe structural, chemical and electron transport properties of In2O3/InN heterostructures and oxidized InN epilayers are reported. It is shown that the accumulation of electrons at the InN surface can be manipulated by the formation of a thin surface oxide layer. The epitaxial In2O3/InN heterojunctions show an increase in the electron concentration due to the increasing band banding at the heterointerface. The oxidation of InN results in improved transport properties and in a reduction of the sheet carrier concentration of the InN epilayer very likely caused by a passivation of surface donors. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Below bandgap emission with intensity higher than band‐to‐band transition in GaAsN
Authors: Sentosa D. , Xiaohong Tang , Chua S. J. , Yin Zongyou 
Published: January 2008

AbstractThe existence of energy level inside the band gap energy of GaAsN was discussed in this paper. The photoluminescence (PL) spectrum of the GaAsN epilayers grown by metal‐organic chemical vapor deposition (MOCVD) consists of two distinguished peaks separated by 0.2 eV energy difference. First peak belongs to the energy band gap transition emission, while the second peak resides at longer wavelength with intensity more than ten times stronger than that of the band‐to‐band emission. The activation energy of this second emission peak is found to be 113 meV. The peak shows a characterization of a defect in the epilayer where its PL intensity decreases when the GaAsN epilayer was exposed to rapid thermal annealing (RTA). This type of defect related emission is the first reported in as‐grown GaAsN epilayer. This defect emission peak can be overcome with optimization of V/III ratio during the MOCVD growth combined with post‐growth RTA annealing. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Contactless electroreflectance spectroscopy of inter‐ and intersub‐band transitions in AlInN/GaInN quantum wells
Authors: Kudrawiec R. , Motyka M. , Cywin’︁ski G. , Siekacz M. , Skierbiszewski C. , Nevou L. , Doyennette L. , Tchernycheva M. , Julien F. H. , Misiewicz J. 
Published: January 2008

AbstractContactless electroreflectance (CER) spectroscopy has been applied to study inter‐ and intesub‐band transitions in AlInN/GaInN multi quantum wells (MQWs). Due to strong built‐in electric field, which is typical of III‐nitrides, interband transitions between all QW subbands have been clearly observed. The energy difference between electron subbands has been found analyzing the 1H1C and 1H2C transitions (or 2H1C and 2H2C transitions), where k Hl C denotes a transition between the k th valence and the l th conduction subbands. In addition, an intersubband transition between the first and the second electron subbands has been observed in CER spectrum at 0.8 eV. It has been observed that the energy difference between electron subbands, which is extracted from interband transitions, is consistent with this one which is obtained from direct measurements of intersubband transitions by CER and photo induced absorption. It shows that CER is very promising technique to study both the inter‐ and intersub‐band transitions in Al(In)N/Ga(In)N QWs. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)