bluuebunny/crossref_metadata_2025 huggingface dataset:
Rapid capillary electrophoresis time‐of‐flight mass spectrometry separations of peptides and proteins using a monoquaternarized piperazine compound (M7C4I) for capillary coatings
Authors: Elhamili Anisa , Wetterhall Magnus , Arvidsson Björn , Sebastiano Roberto , Righetti Pier Giorgio , Bergquist Jonas
Published: March 2008

A monoquaternarized piperazine, 1‐(4‐iodobutyl) 4‐aza‐1‐azoniabicyclo[2,2,2] octane iodide (M7C4I), has been evaluated as a surface derivatization reagent for CE in combination with TOF MS for the analysis of proteins, peptides, and protein digests. The M7C4I piperazine, at alkaline pH, forms a covalent bond via alkylation of the ionized silanols producing a cationic surface with a highly stable and reversed EOF. The obtained surface yields rapid separations (less than 5 min) of peptides and proteins at acidic pH with high separation efficiencies (up to 1.1×106 plates/m for peptides and up to 1.8×106 plates/m for proteins) and no observed bleeding of the coating reagent into the mass spectrometer. The simplicity of the coating procedure also enables fast (2 min) regeneration of the surface, if necessary. This is useful in the analysis of complex samples in order to prevent possible memory effects. The potential of using M7C4I‐coated capillaries for MS analysis of complex samples is demonstrated by the separation of peptides, proteins, and protein digests. Even more, the spectacular thing in which large intact proteins with molecular masses over 0.5 MDa could be separated. The coating showed good ability to handle these large proteins with high efficiency and retained peak shape as demonstrated by separation of IgG1 (150 kDa) and thyroglobulin (669 kDa).
Capillary electrophoresis of boron cluster compounds in aqueous and nonaqueous solvents
Authors: Valeri Anna Lucia , Kremser Leopold , Raggi Maria Augusta , Grüner Bohumir , Vespalec Radim , Kenndler Ernst
Published: March 2008

The electrophoretic properties of boron cluster compounds were determined in water, methanol and ACN as solvents of the BGE and discussed based on the principles of ion migration. Two types of boron cluster compounds were investigated. One type consisted of derivatives of the nido‐7,8‐dicarbaundecaborate cluster, the other types are derivatized cobalt bis(dicarbollide) ions (COSANs) whose central cobalt atom is sandwiched by two 7,8‐dicarbaundecaborate clusters. The BGE in all solvents was acetate/acetic acid buffer with pH 4.75 in water, 9.7 in methanol and 22.3 in ACN, respectively, at different ionic strength between 5 and 30 mM. The dependence of the mobility on ionic strength could not be explained by the theory of Debye, Hückel and Onsager, but good agreement was found upon considering an ion size parameter. Limiting mobilities were derived by curve fitting, and by the aid of the solvent viscosities the hydrodynamic radii of the analyte anions were calculated. They are between 0.25 and 0.48 nm, and were nearly independent of the solvent. Electrophoresis of the analytes in a BGE consisting of 6 mM perchloric acid in ACN allows the conclusion that the present boron cluster compounds behave as stronger acids than perchloric acid.
Combined effects of carbon, nitrogen and phosphorus substrates on D‐ribose production via transketolase deficient strain of Bacillus pumilus
Authors: Srivastava Rajesh K , Wangikar Pramod P
Published: March 2008

BACKGROUND: D‐ribose, a five carbon sugar, can be produced via mutant strains with impairment in the non‐oxidative part of the pentose phosphate pathway (PPP). D‐ribose is an important intermediate in the pharmaceutical industry. This work focuses on the effect of various substrates on D‐ribose production with a transketolase deficient strain of Bacillus pumilus IFO13322.

RESULT: D‐ribose titer is found to increase with a concomitant decrease in the yield (on a g product g−1 substrate basis) with increasing glucose concentration. Likewise, higher concentration of ammonium sulfate led to lower product yield while glucose and corn steep liquor concentrations were kept unaltered. Among the complex nitrogen substrates, cas amino acids showed better product yield than corn steep liquor. When tested for supplements of defined amino acids, media supplemented with tyrosine, phenylalanine, tryptophan and histidine gave better yields and higher biomass growth. This is possibly due to the fact that mutant strain is an aromatic amino acids auxotroph owing to impairment in aromatic amino acid biosynthesis. Further, higher phosphate concentrations in the media led to greater biomass formation and lower D‐ribose yield.

CONCLUSIONS: At higher glucose or ammonium sulfate concentrations, a greater proportion of the carbon was channeled toward byproducts such as acetate, and acetoin and biomass formation. Thus, the relative rates of PPP and in turn the D‐ribose yield were dependent on not only the carbon substrate concentration but also the nitrogen and phosphorus substrates. Copyright © 2008 Society of Chemical Industry
Study of the bio‐production of carotenoids by Sporidiobolus salmonicolor (CBS 2636) using pre‐treated agro‐industrial substrates
Authors: Valduga Eunice , Valério Alexsandra , Treichel Helen , Di Luccio Marco , Furigo Júnior Agenor
Published: March 2008

BACKGROUND: The increasing industrial demand for carotenoids has aroused interest in their bio‐production, and the need to reduce production costs has encouraged the use of low cost industrial substrates, such as agro‐industrial residues. Thus the objective of this research was the bio‐production of carotenoids by Sporidiobolus salmonicolor using agro‐industrial substrates (corn steep liquor and sugarcane molasses), pre‐treated with acids (sulphuric and phosphoric).

RESULTS: Bio‐production was carried out in an orbital shaker using a 10% (v/v) inoculum, incubation at 25 °C, and agitation at 180 rpm for 120 h in a non‐illuminated environment. The carotenoids were recovered using liquid N2 combined with dimethylsulphoxide for cell rupture, and an acetone/methanol mixture (7:3 v/v) for extraction.

CONCLUSION: The complete second‐order design allowed for optimisation of the carotenoid concentration obtained from industrial substrates pre‐treated with acids (sulphuric and phosphoric), obtaining a total carotenoid content of 541.5 µg L−1 using 10 g L−1 sugarcane molasses, 5 g L−1 corn steep liquor and 5 g L−1 yeast hydrolysate at 25 °C, with agitation at 180 rpm and an initial pH of 4.0. Copyright © 2008 Society of Chemical Industry
Recognition of the Helix‐Loop‐Helix domain of the Id proteins by an artificial luminescent metal complex receptor
Authors: Kiewitz Sebastian D. , Kruppa Michael , Riechers Alexander , König Burkhard , Cabrele Chiara
Published: March 2008

Synthetic agents specifically interacting with a protein interface are important not only for the better understanding of protein dimer or complex formation but also for medical applications. Here we describe the recognition of the helix‐loop‐helix (HLH) dimerization domain of the Id proteins by an artificial luminescent receptor containing two binding sites for a Lewis acid and a Lewis base, respectively. The Id proteins are inhibitors of bHLH transcription factors and play key roles during development of cancer. We show that a receptor/Id‐HLH‐domain complex was formed cooperatively (K0.5 ∼2 µM under physiological conditions) and with moderate specificity, as compared to the related MyoD and Max HLH domains. Accordingly, a preferred receptor binding motif, CYSR(K), was identified within the Id HLH domains. These results are promising and may be exploited to design highly selective synthetic receptors for the Id HLH domain. Copyright © 2008 John Wiley & Sons, Ltd.
Conformational flexibility and kinetic complexity in antibody–antigen interactions
Authors: Kourentzi Katerina , Srinivasan Mohan , Smith‐Gill Sandra J. , Willson Richard C.
Published: March 2008

The kinetics of dissociation of three structurally characterized anti‐hen egg white lysozyme antibodies (H8, H10, and H26), with hen egg white lysozyme (HEL) and the avian variant Japanese quail lysozyme (JQL) were examined. These antibodies share over 90% sequence identity and recognize the same epitope, but differ in their degree of cross‐reactivity and predicted combining site rigidity. Competitive dissociation induced by the addition of excess unlabeled HEL after varied periods of antibody–antigen association was followed in real time using fluorescence anisotropy. Dissociation was in many cases non‐single‐exponential, and the observed off‐rates became slower as the complex age increased, suggesting multi‐step association kinetics consistent with an encounter‐docking view of protein–protein interactions. The fully docked fraction of the complexes just prior to inducing dissociation was high for the HEL complexes but was dramatically reduced for JQL complexes, that is final docking was antigen‐sensitive. Variations among the systems can be understood in terms of the complexes' differing conformational flexibilities, based on the encounter‐docking model of protein–protein associations. Copyright © 2008 John Wiley & Sons, Ltd.
A simple and convenient approach for evaluation of the parameters of ligand–receptor interaction. Receptor blocking index and its application
Authors: Bobrovnik S. A.
Published: March 2008

A new approach for determination of the parameters for ligand‐receptor interaction, which is based on so‐called dilution coordinates, was developed earlier. Equations that allow evaluation of not only the affinity of ligand‐receptor interaction but also of the amount of free (or occupied by corresponding ligand) receptors were suggested. The most important advantage of this approach as compared with well‐known methods is the ability to determine the binding parameters for ligand‐receptor interaction even for the cases in which ligand and receptor are already present in a mixture and separation of counterparts from each other is technically difficult or even impossible. Due to this reason, the proposed approach can be especially useful for studying interactions between highly‐labile biological receptors and corresponding ligands as found in vivo. In the present paper I continue to consider how to determine the binding parameters for a given ligand‐receptor interaction if the value of receptor blocking index is determined experimentally. Copyright © 2008 John Wiley & Sons, Ltd.
Design, synthesis and screening of antisense peptide based combinatorial peptide libraries towards an aromatic region of SARS‐CoV
Authors: Huang Yanyan , Zhao Rui , Luo Jia , Xiong Shaoxiang , Shangguan Dihua , Zhang Hongwu , Liu Guoquan , Chen Yi
Published: March 2008

A combination of high‐performance affinity chromatography and antisense peptide based combinatorial peptide libraries was used to screen a potential inhibitor for SARS‐CoV. An aromatic‐amino acid‐rich region within the transmembrane domain at the C terminal of spike (S) protein identified as a membrane‐active region was chosen as the target sense peptide (SP) and immobilized as affinity ligand. Four antisense peptides were designed based on the degeneracy of genetic codes. One of them was screened as the lead peptide to construct the extended peptide libraries (EPL). The library screening was carried out at pH 5.5 so as to mimic the low‐pH milieu required by virus fusion. After five cycles of screening, a dodecapeptide KKKKYRNIRRPG (DP) was identified to possess the highest binding affinity to the immobilized sense peptide. The dissociation constant of the complex between the DP and the SP was 5.64 × 10−7 M in a physiological condition. The recognition between the DP and recombinant SARS S protein was demonstrated by ELISA assay to be in a saturable way. The competitive inhibition of the sense peptide in the competitive ELISA reveals the affinity binding between the DP and SARS S protein is specific and directed towards the target SP of the S protein. The results indicate this preferred polypeptide can be used as a lead compound of potent inhibitor of SARS‐CoV. The mechanism study suggests the specific recognition between the DP and the target peptide was due to sequence‐dependent and multi‐modal affinity interaction. Copyright © 2008 John Wiley & Sons, Ltd.
Sensitivity of knee replacement contact calculations to kinematic measurement errors
Authors: Fregly Benjamin J. , Banks Scott A. , D'Lima Darryl D. , Colwell Clifford W.
Published: March 2008

The ability to measure in vivo knee kinematics accurately makes it tempting to calculate in vivo contact forces, pressures, and areas directly from kinematic data. However, the sensitivity of contact calculations to kinematic measurement errors has not been adequately investigated. To address this issue, we developed a series of sensitivity analyses derived from a validated in vivo computational simulation of gait. The simulation used an elastic foundation contact model to reproduce in vivo contact force, center of pressure, and fluoroscopic motion data collected from an instrumented knee replacement. Treating each degree of freedom (DOF) in the simulation as motion controlled, we first quantified how errors in measured relative pose of the implant components affected contact calculations. Pose variations of ±0.1 mm or degree over the entire gait cycle changed maximum contact force, pressure, and area by 204, 100, and 117%, respectively. Larger variations of ±0.5 mm or degree changed these same quantities by 1157, 108, and 578%, respectively. In both cases, the largest sensitivities were to errors in superior‐inferior translation and varus‐valgus rotation, with loss of contact occurring on one or both sides. We then quantified how switching the sensitive DOFs from motion to load control affected the sensitivity results. Pose variations of ±0.5 mm or degree in the remaining DOFs changed maximum contact quantities by at most 3%. These results suggest that accuracy on the order of microns and milliradians is needed to estimate contact forces, pressures, and areas directly from in vivo kinematic measurements, and that use of load rather than motion control for the sensitive DOFs may improve the accuracy of in vivo contact calculations. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1173–1179, 2008
Gender differences in passive knee biomechanical properties in tibial rotation
Authors: Park Hyung‐Soon , Wilson Nicole A. , Zhang Li‐Qun
Published: March 2008

The anterior cruciate ligament (ACL) is the most commonly injured knee ligament with the highest incidence of injury in female athletes who participate in pivoting sports. Noncontact ACL injuries commonly occur with both internal and external tibial rotation. ACL impingement against the lateral wall of the intercondylar notch during tibial external rotation and abduction has been proposed as an injury mechanism, but few studies have evaluated in vivo gender‐specific differences in laxity and stiffness in external and internal tibial rotations. The purpose of this study was to evaluate these differences. The knees of 10 male and 10 female healthy subjects were rotated between internal and external tibial rotation with the knee at 60° of flexion. Joint laxity, stiffness, and energy loss were compared between male and female subjects. Women had higher laxity (p = 0.01), lower stiffness (p = 0.038), and higher energy loss (p = 0.008) in external tibial rotation than did men. The results suggest that women may be at greater risk of ACL injury resulting from impingement against the lateral wall of the intercondylar notch, which has been shown to be associated with external tibial rotation and abduction. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:937–944, 2008
Effect of wrist posture on carpal tunnel pressure while typing
Authors: Rempel David M. , Keir Peter J. , Bach Joel M.
Published: March 2008

Long weekly hours of keyboard use may lead to or aggravate carpal tunnel syndrome. The effects of typing on fluid pressure in the carpal tunnel, a possible mediator of carpal tunnel syndrome, are unknown. Twenty healthy subjects participated in a laboratory study to investigate the effects of typing at different wrist postures on carpal tunnel pressure of the right hand. Changes in wrist flexion/extension angle (p = 0.01) and radial/ulnar deviation angle (p = 0.03) independently altered carpal tunnel pressure; wrist deviations in extension or radial deviation were associated with an increase in pressure. The activity of typing independently elevated carpal tunnel pressure (p = 0.001) relative to the static hand held in the same posture. This information can guide the design and use of keyboards and workstations in order to minimize carpal tunnel pressure while typing. The findings may also be useful to clinicians and ergonomists in the management of patients with carpal tunnel syndrome who use a keyboard. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1269–1273, 2008
Models of tibial fracture healing in normal and Nf1‐deficient mice
Authors: Schindeler Aaron , Morse Alyson , Harry Lorraine , Godfrey Craig , Mikulec Kathy , McDonald Michelle , Gasser Jürg A. , Little David G.
Published: March 2008

Delayed union and nonunion are common complications associated with tibial fractures, particularly in the distal tibia. Existing mouse tibial fracture models are typically closed and middiaphyseal, and thus poorly recapitulate the prevailing conditions following surgery on a human open distal tibial fracture. This report describes our development of two open tibial fracture models in the mouse, where the bone is broken either in the tibial midshaft (mid‐diaphysis) or in the distal tibia. Fractures in the distal tibial model showed delayed repair compared to fractures in the tibial midshaft. These tibial fracture models were applied to both wild‐type and Nf1‐deficient (Nf1+/−) mice. Bone repair has been reported to be exceptionally problematic in human NF1 patients, and these patients can also spontaneously develop tibial nonunions (known as congenital pseudarthrosis of the tibia), which are recalcitrant to even vigorous intervention. pQCT analysis confirmed no fundamental differences in cortical or cancellous bone in Nf1‐deficient mouse tibiae compared to wild‐type mice. Although no difference in bone healing was seen in the tibial midshaft fracture model, the healing of distal tibial fractures was found to be impaired in Nf1+/− mice. The histological features associated with nonunited Nf1+/− fractures were variable, but included delayed cartilage removal, disproportionate fibrous invasion, insufficient new bone anabolism, and excessive catabolism. These findings imply that the pathology of tibial pseudarthrosis in human NF1 is complex and likely to be multifactorial. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1053–1060, 2008
Polarized Raman scattering and lattice eigenmodes of antiferromagnetic NdFeO3
Authors: Singh Manoj K. , Jang Hyun M. , Gupta H. C. , Katiyar Ram S.
Published: March 2008

The first‐ and second‐order Raman‐active phonons in the orthorhombic Pbnm NdFeO3 single crystals were studied by means of polarized Raman scattering and lattice dynamics computations (LDC). The zone‐center phonons of Ag symmetry were distinguished from the B1g eigenmodes by performing polarized Raman scattering experiments using two parallel polarization configurations, X′(ZZ)X′ and Z(X′X′)Z. With the help of LDC, we were able to assign most of the observed Raman‐active modes, including phonons of B2g and B3g symmetry. The LDC results indicated that among the 16 force constants employed, the one corresponding to the stretching vibration between the central Fe cation and the axial oxygen atom in a FeO6 octahedron unit had the largest value. This suggests that the B‐site Fe cation is more tightly bound to the axial O1 ion than the other two equatorial O2 ions. It was further shown that at higher wavenumbers, the displacement of oxygen atoms contributed dominantly to the zone‐center vibrations. Copyright © 2008 John Wiley & Sons, Ltd.
Macromol. Chem. Phys. 6/2008
Authors: Bormashenko Edward , Malkin Alexander , Musin Albina , Bormashenko Yelena , Whyman Gene , Litvak Natalya , Barkay Zahava , Machavariani Vladimir
Published: March 2008

Cover: The cover shows an SEM image of the honeycomb pattern obtained with evaporated polystyrene solution (upper right corner) along with 3D SEM picture of the same sample. Poly(ethylene glycol) and polyorganosilanes/‐siloxanes promote the formation of ordered structures. Further details can be found in the article by E. Bormashenko,* A. Malkin, A. Musin, Y. Bormashenko, G. Whyman, N. Litvak, Z. Barkay, and V. Machavariani on page 567.
Fragile X syndrome associated with tic disorders
Authors: Schneider Susanne A. , Robertson Mary M. , Rizzo Renata , Turk Jeremy , Bhatia Kailash P. , Orth Michael
Published: March 2008

Movement disorders other than late onset tremor‐ataxia in association with fragile X syndrome, the most common identifiable cause of inherited mental retardation, seem to be rare. Here we describe five male patients from three unrelated families with fragile X syndrome that presented with motor and phonic tics. Clinically, 4 patients fulfilled diagnostic criteria for Gilles de la Tourette syndrome (GTS) while 1 patient would have been diagnosed with an adult onset tic disorder. However, in all patients onset of tics was considerably later than in typical GTS. Three patients had atypical tics and two patients reported waxing and waning of tic intensity over time. Four of the 5 patients showed clinical signs typical of fragile X syndrome, in particular dysmorphic features, learning difficulties and speech and language problems that required special treatment. All patients had co‐morbidities common to both GTS and fragile X syndrome. We suggest considering fragile X syndrome in GTS complicated by co‐morbidity with late onset of atypical tics, in particular when learning disability and dysmorphic features are present. © 2008 Movement Disorder Society
Synthesis of a novel series of polymerizable surfactants and application in emulsion polymerization
Authors: Sun Yingli , Qiao Weihong , Liu Hongzhu
Published: March 2008

A series of polymerization surfactants (surfmers) was synthesized, whose structures combined the characteristics of polyoxyethylene as nonionic group and quaternary ammonium a as cationic group. The structures of the product were confirmed by MS, and the content of cationic‐activity matter was determined by two‐phase titration. The surfmers were then used with constant addition profiles in semicontinuous polymerization of vinyl acetate–butyl acrylate–Veova 10–hexafluorobutyl methacrylate, and the polydispersity indexes (PDI) were lower than 0.1. The particle size, amount of coagulum, and stability against electrolyte and freeze/thaw were evaluated. As a reference, an unreactive surfactant cetyl trimethyl ammonium bromide (CTAB) was also used for the polymerization. Compared to CTAB, the surfmers behaved much better. Not only stabilities to electrolyte and water resistance were improved, but also freeze/thaw stability got a superior performance. Copyright © 2008 John Wiley & Sons, Ltd.
Glioblastoma stem cells produce vascular endothelial growth factor by activation of a G‐protein coupled formylpeptide receptor FPR
Authors: Yao X‐H , Ping Y‐F , Chen J‐H , Xu C‐P , Chen D‐L , Zhang R , Wang JM , Bian X‐W
Published: March 2008

Glioma stem cells (GSCs), or stem cell‐like glioma cells, isolated from malignant glioma cell lines, were capable of producing vascular endothelial growth factor (VEGF). However, the exact role of such tumour cells in angiogenesis remains unknown. In this study, we isolated a small proportion of CD133+ GSCs from the human glioblastoma cell line U87 and found that these GSCs possessed multipotent differentiation potential and released high levels of VEGF as compared with CD133− tumour cells. The CD133+ GSCs also formed larger xenograft tumours that contained higher VEGF immunoreactivity and denser microvessels. Moreover, GSCs expressed a functional G protein‐coupled formylpeptide receptor FPR, which was activated by a chemotactic peptide ligand, N‐formylmethionyl‐leucyl‐phenylalanine (fMLF), to mediate calcium flux and the production of VEGF by GSCs. Our results indicate that FPR expressed by human GSCs may play an important role in glioma angiogenesis. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Current awareness: Pharmacoepidemiology and drug safety
Authors:   John Wiley & Sons, Ltd.
Published: March 2008

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 pharmacoepidemiology and drug safety. Each bibliography is divided into 20 sections: 1 Reviews; 2 General; 3 Anti‐infective Agents; 4 Cardiovascular System Agents; 5 CNS Depressive Agents; 6 Non‐steroidal Anti‐inflammatory Agents; 7 CNS Agents; 8 Anti‐neoplastic Agents; 9 Haematological Agents; 10 Neuroregulator‐Blocking Agents; 11 Dermatological Agents; 12 Immunosuppressive Agents; 13 Autonomic Agents; 14 Respiratory System Agents; 15 Neuromuscular Agents; 16 Reproductive System Agents; 17 Gastrointestinal System Agents; 18 Anti‐inflammatory Agents ‐ Steroidal; 19 Teratogens/fetal exposure; 20 Others. 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.
The association between substance use co‐morbidity in adolescence and adult criminal behaviour
Authors: Kjelsberg Ellen
Published: March 2008

The impact of substance use co‐morbidity in adolescence on criminal behaviour in adulthood was investigated in a long‐term follow‐up study of former adolescent psychiatric in‐patients. A nationwide representative sample of 1  095 adolescents (46% females) was followed up 15‐33 years after admission to the National Centre for Child and Adolescent Psychiatry, Oslo, Norway. At index hospitalisation in adolescence, 32% fulfilled the DSM‐IV criteria for a co‐morbid substance use disorder (SUD). At follow‐up, 63% of all males and 39% of all females had received a court conviction. SUD in adolescence seemed to be a sine qua non for later registered overall criminality in females but not in males. The association between substance use co‐morbidity and later violent offending was strong in both genders. Substance use was closely associated with life‐course‐persistent criminality and more serious criminal careers in both genders. Substance use was also associated with increased mortality. Analysing secular trends in criminal activity during the last several decades, we found that substance use co‐morbidity remained an independent predictor for violent and drug related offences in both genders after controlling for cohort membership. The findings could help identify high‐risk populations in need of preventive interventions. Copyright © 2008 John Wiley & Sons, Ltd.
Profiling the metabolic proteome of bovine mammary tissue
Authors: Beddek Amanda J. , Rawson Pisana , Peng Lifeng , Snell Russell , Lehnert Klaus , Ward Hamish E. , Jordan T. William
Published: March 2008

2‐DE and MALDI mass fingerprinting were used to analyse mammary tissue from lactating Friesian cows. The goal was detection of enzymes in metabolic pathways for synthesis of milk molecules including fatty acids and lactose. Of 418 protein spots analysed by PMF, 328 were matched to database sequences, resulting in 215 unique proteins. We detected 11 out of the 15 enzymes in the direct pathways for conversion of glucose to fatty acids, two of the pentose phosphate pathway enzymes and two of the enzymes for lactose synthesis from glucose. We did not detect enzymes that catalyse the first three reactions of glycolysis. Our results are typical of enzyme detection using 2‐DE of mammalian tissues. We therefore advocate caution when relating enzyme abundances measured by 2‐DE to metabolic output as not all relevant proteins are detected. 2‐D DIGE was used to measure interindividual variation in enzyme abundance from eight animals. We extracted relative protein abundances from 2‐D DIGE data and used a logratio transformation that is appropriate for compositional data of the kind represented in many proteomics experiments. Coefficients of variation for abundances of detected enzymes were 3–8%. We recommend use of this transformation for DIGE and other compositional data.
Characterizing the dynamic nature of the Yersinia pestis periplasmic proteome in response to nutrient exhaustion and temperature change
Authors: Pieper Rembert , Huang Shih‐Ting , Clark David J. , Robinson Jeffrey M. , Parmar Prashanth P. , Alami Hamid , Bunai Christine L. , Perry Robert D. , Fleischmann Robert D. , Peterson Scott N.
Published: March 2008

The periplasmic proteome of Yersinia pestis strain KIM6+ was characterized using differential 2‐DE display of proteins isolated from several subcellular fractions. Circa 160 proteins were designated as periplasmic, including 62 (putative) solute‐binding proteins of ATP‐binding cassette (ABC) transporters (SBPs) and 46 (putative) metabolic enzymes. More than 30 SBPs were significantly increased in abundance during stationary phase cell growth, compared to the exponential phase. The data suggest that nutrient exhaustion in the stationary phase triggers cellular responses resulting in the induced expression of numerous ABC transporters, which are responsible for the import of solutes/nutrients. Limited availability of inorganic phosphate (Pi) also caused dramatic proteomic changes. Nine proteins were functionally linked to the mobilization and import of three small molecules (Pi, phosphonate and glycerol‐3‐phosphate) and accounted for nearly half of the total protein mass in the periplasm of Pi‐starved cells. When cells were grown at 26°C versus 37°C, corresponding to ambient temperatures in the flea vector and mammalian hosts, respectively, several periplasmic proteins with no known roles in the Y. pestis life cycle were strongly altered in abundance. This included a putative nitrate/sulfonate/bicarbonate‐specific SBP (Y1004), encoded by the virulence‐associated plasmid pMT1 and increased in abundance at 37°C.
Treatment of missing values for multivariate statistical analysis of gel‐based proteomics data
Authors: Pedreschi Romina , Hertog Maarten L. A. T. M. , Carpentier Sebastien C. , Lammertyn Jeroen , Robben Johan , Noben Jean‐Paul , Panis Bart , Swennen Rony , Nicolaï Bart M.
Published: March 2008

The presence of missing values in gel‐based proteomics data represents a real challenge if an objective statistical analysis is pursued. Different methods to handle missing values were evaluated and their influence is discussed on the selection of important proteins through multivariate techniques. The evaluated methods consisted of directly dealing with them during the multivariate analysis with the nonlinear estimation by iterative partial least squares (NIPALS) algorithm or imputing them by using either k‐nearest neighbor or Bayesian principal component analysis (BPCA) before carrying out the multivariate analysis. These techniques were applied to data obtained from gels stained with classical postrunning dyes and from DIGE gels. Before applying the multivariate techniques, the normality and homoscedasticity assumptions on which parametric tests are based on were tested in order to perform a sound statistical analysis. From the three tested methods to handle missing values in our datasets, BPCA imputation of missing values showed to be the most consistent method.
Functionalization of multiwalled carbon nanotube via surface reversible addition fragmentation chain transfer polymerization and as lubricant additives
Authors: Pei Xiaowei , Liu Weimin , Hao Jingcheng
Published: March 2008

Polymer‐grafted multiwalled carbon nanotube (MWCNT) hybrid composite which possess a hard backbone of MWCNT and a soft shell of brush‐like polystyrene (PSt) were synthesized. The reversible addition fragmentation chain transfer (RAFT) agents were successfully immobilized onto the surface of MWCNT first, and PSt chains were subsequently grafted from sidewall of MWCNT via RAFT polymerization. Chemical structure of resulting product and the quantities of grafted polymer were determined by Fourier transform infrared, thermal gravimetric analysis, nuclear magnetic resonance, and X‐ray photoelectron spectra. Transmission electron microscopy and field emission scanning electron microscopy images clearly indicate that the nanotubes were coated with a polymer layer. Furthermore, the functionalized MWCNT as additives was added to base lubricant and the tribological property of resultant MWCNT lubricant was investigated with four‐ball machines. The results indicate that the functionalization led to an improvement in the dispersion of MWCNT and as additives it amended the tribological property of base lubricant. The mechanism of the significant improvements on the tribological properties of the functionalized MWCNT as additives was discussed. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3014–3023, 2008
Synthesis and characterization of amphiphilic fluorinated pentablock copolymers based on Pluronic F127
Authors: He Jinlin , Ni Peihong , Liu Cuicui
Published: March 2008

The synthesis and self‐assembly behavior of pentablock copolymers consisting of Pluronic F127 (PEO100‐PPO65‐PEO100) and poly(2, 2, 3, 3, 4, 4, 5, 5‐octafluoropentyl methacrylate) (POFPMA) is herein described. Using the difunctional potassium alcoholate of F127, K+O–‐(PEO100‐PPO65‐PEO100)‐O–K+, as the macroinitiator, the POFPMA‐F127‐POFPMA pentablock copolymers were synthesized via oxyanion‐initiated polymerization. The chain length of POFPMA can be controlled by the original molar ratio of macroinitiator to OFPMA monomer, that is, F‐monomer. The composition and chemical structure of POFPMA‐F127‐POFPMA pentablock copolymers have been characterized by FTIR, 1HNMR, and 19F NMR spectroscopy, and gel permeation chromatography techniques. The solution behavior of POFPMA‐F127‐POFPMA copolymers was investigated by the methods of surface tension, cloud point, transmission electron microscopy, and high performance particle sizer (HPPS). The results indicate that these Pluronic F127‐based block copolymers modified with fluorinated segments possess relatively high surface activity and low cloud points, depending on various factors, such as the length of fluorinated block, the concentration of the copolymers in aqueous solution, and the adscititious inorganic salt. TEM measurements showed that the pentablock copolymers can self‐assemble in aqueous solution to form various micellar morphologies. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3029–3041, 2008
Germanes as efficient coinitiators in radical and cationic photopolymerizations
Authors: Lalevée Jacques , Dirani Ali , El‐Roz Mohamad , Allonas Xavier , Fouassier Jean Pierre
Published: March 2008

In this article, germanes are presented as new coinitiators for both radical and cationic photopolymerization processes. For the free radical polymerization process, the newly proposed structures are characterized by efficiencies similar or better than the reference amine. Germyl radicals are also found to be excellent initiators for free radical promoted cationic photopolymerization (FRPCP) of an epoxy resin. The associated reactivity is even better under air. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3042–3047, 2008
Thermal conductivity of porous copper manufactured by the lost carbonate sintering process
Authors: Thewsey D. J. , Zhao Y. Y.
Published: March 2008

This article describes an experimental investigation on the thermal conductivity of open‐celled porous copper manufactured by the Lost Carbonate Sintering process. The thermal conductivity was either measured directly using Corsan's method or calculated from electrical conductivity values using the Wiedemann–Franz law. The relationship between thermal conductivity and relative density followed the power law, with the exponents being 2.05 for the former and 2.96 for the latter method. The thermal conductivity measured by Corsan's method was higher than that calculated from electrical conductivity, mainly because the sintering defects in the cell walls made contributions to thermal conduction but not to electrical conduction. The pore size had no significant effect on the thermal conductivity. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical characterization of AlGaN/GaN on AlN substrates
Authors: Mitchel W. C. , Elhamri S. , Landis G. , Gaska R. , Schujman S. B. , Schowalter L. J.
Published: March 2008

The results of an electrical transport study of an AlGaN/GaN heterostructure grown on a bulk AlN substrate are presented. Temperature dependent Hall effect and magnetoresistance measurements were made on an MOCVD grown heterostructure. The temperature dependences of the carrier concentration and mobility are characteristic of a two‐dimensional electron gas (2DEG). The carrier concentration was 1.19x1013 cm–2 at room temperature and 1.02x1013 cm–2 at 77 K while the mobility was 1100 cm2/Vs at room temperature and 5280 cm2/Vs at 77 K. The magnetoresistance measurements revealed the presence of Shubnikov – de Haas (SdH) oscillations. Illumination of the sample resulted in a persistent photocurrent, and an enhanced SdH oscillation amplitude with an increased quantum scattering time. The ratio of the classical to quantum scattering times, τc/τq, was 4.3, which is similar to values for AlGaN/GaN structures on other substrates. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Enhancement of (AlGaIn)N near‐UV LED efficiency using freestanding GaN substrate
Authors: Maier M. , Köhler K. , Kunzer M. , Wiegert J. , Liu S. , Kaufmann U. , Wagner J.
Published: March 2008

The effect of freestanding GaN‐substrates with low defect density (DD) on the electroluminescence (EL) characteristics of near UV‐LEDs has been investigated. Three series of LED‐structures with wavelengths between 377 nm and 435 nm are compared, one grown on freestanding HVPE GaN‐substrates, one grown on low dislocation GaN templates on sapphire (ULD), and one grown directly on sapphire substrates with conventional low temperature nucleation. The reduction in DD results in an enhancement of the EL intensity over the whole wavelength range, which is particularly pronounced for wavelengths shorter than 390 nm. Comparing the output power of LEDs on these three different substrates special attention has to be paid to differences in light extraction efficiency. Though band‐to‐band absorption limits the use of freestanding GaN to wavelengths exceeding 380 nm, it offers the possibility to enhance the light extraction via simple backside surface texturing by a factor of at least 2. This way we fabricated a LED‐structure on freestanding GaN with an output power measured on‐wafer of 13 mW at 395 nm and 40 mA injection current, i.e. an enhancement in EL intensity of 270% over the same LED structure grown on sapphire. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimization of underlying layer and the device structure for group‐III‐nitride‐based UV emitters on sapphire
Authors: Iida K. , Watanabe H. , Takeda K. , Mori F. , Tsuzuki H. , Yamashita Y. , Iwaya M. , Kamiyama S. , Amano H. , Akasaki I. , Maruyama H. , Takagi T. , Bandoh A.
Published: March 2008

Epitaxial lateral overgrowth (ELO) was applied for the growth of AlGaN on a sapphire substrate by metalorganic vapor phase epitaxy. Among several processes, the ELO of AlGaN on grooved AlGaN showed the best surface morphology and the lowest dark‐spot density of 1×108 cm–2 as measured using cathodoluminescence. The light output power of a UV LED fabricated on ELO‐Al0.25Ga0.75N on grooved Al0.25Ga0.75N was the strongest among several UV LEDs fabricated by different processes. The effect of the Al composition in the electron‐blocking (EB) layer on the performance of UV LEDs was investigated. The UV LED with a low‐Al‐content EB layer showed high output power under a low‐injection condition, while the output power of a UV LED with a high‐Al‐content EB layer did not saturate even under a high‐injection condition. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
AlN MSM and Schottky photodetectors
Authors: Dahal R. , Li J. , Fan Z. Y. , Nakarmi M. L. , Tahtamouni T. M. Al , Lin J. Y. , Jiang H. X.
Published: March 2008

Deep ultraviolet (DUV) AlN Metal‐Semiconductor‐Metal (MSM) and Schottky barrier photodetectors have been demonstrated by exploiting the epitaxial growth of high quality AlN epilayer on sapphire and n‐SiC substrates, respectively. The fabricated photodetectors exhibited peak responsivity at 200 nm with very sharp cut‐off wavelength at 207 nm along with extremely low dark current, very high breakdown voltages, high responsivity and high DUV to UV/visible rejection ratio. AlN Schottky barrier detectors show high zero bias responsivity and very high thermal energy limited detectivity at zero bias. These outstanding features are direct attributes of the fundamental material properties and high quality of AlN epilayers. These results demonstrated that AlN could be an excellent candidate as an active material for next generation DUV opto‐electronic device applications. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
GaN thin films on z‐ and x ‐cut LiNbO3 substrates by MOVPE
Authors: Ougazzaden A. , Moudakir T. , Aggerstam T. , Orsal G. , Salvestrini J. P. , Gautier S. , Sirenko A. A.
Published: March 2008

We report epitaxial growth of GaN layers on z ‐ and x ‐cut LiNbO3 substrates using MOVPE. GaN layers with the thickness of 450 nm were characterized using X‐ray diffraction. For both, z‐ and x‐ cut orientations of LiNbO3 substrates, the GaN layers have c‐axis orientation normal to the substrate plane and the in‐plane lattice orientation of GaN layers coincides with the primary axes of LiNbO3 substrates. Although GaN layers exhibit almost complete strain relaxation, the residual compressive strain determined with respect to a free‐standing GaN is of the order of +0.37% and +0.2% for z ‐ and x ‐cut substrates, respectively. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Processing efficiency of elastic emission machining for low‐thermal‐expansion material
Authors: Kanaoka Masahiko , Liu Changling , Nomura Kazushi , Ando Manabu , Takino Hideo , Fukuda Yasuaki , Mori Yuzo , Mimura Hidekazu , Yamauchi Kazuto
Published: March 2008

Extreme ultraviolet (EUV) lithography is currently being developed as a next‐generation lithography system. In this system, light at a wavelength of 13.4 nm is used, allowing the patterning of lines with dimensions of less than 40 nm. To focus the light, high‐precision optical mirrors are required with a surface roughness of 0.1 nm. In addition, mirror substrates must be low‐thermal‐expansion materials because EUV light is easily absorbed in matter, accordingly converted to heat. ULE (Corning Inc.) and Zerodur (SCHOTT AG) are well‐known examples of such materials. To achieve these requirements for EUV lithography, a high‐performance machining method is needed. In previous studies, the machining performance of elastic emission machining (EEM) for the above materials was examined from the viewpoint of roughness improvement. As a result, we considered that EEM has sufficient figuring and smoothing capability for the fabrication of EUV optics. We next evaluate the processing efficiency of EEM. In this study, the processing efficiency of EEM for a low‐thermal‐expansion material was examined from the viewpoint of the removal rate. As a result of this investigation, the conditions under which the efficiency of EEM is increased were clarified. We analyzed and discussed these conditions. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of change in number of conduction electrons on the spin configuration in transition metal oxides
Authors: Minamitani Emi , Roleda Robert , Diño Wilson Agerico , Kishi Tomoya , Nakanishi Hiroshi , Kasai Hideaki
Published: March 2008

We study the correlation between the spin configuration and the average number of conduction electrons, based on the Kondo lattice type Hamiltonian. We found that a change in the average number of conduction electrons causes a change in the spin configuration. This results from the competition among the strong Coulomb repulsion, Hund's coupling, and antiferromagnetic interaction. A change in spin configuration from an antiferromagnetic ordering to a spin spiral state can be initiated by slightly doping holes into the half‐filled state. We also found that the spin spiral state exhibits a correspondingly larger conductance than the antiferromagnetic state. On the basis of these results, we suggest that it is possible to alter the conductance (transport property) of transition metal oxides by inducing a change in the spin configuration through the application of an external voltage. Copyright © 2008 John Wiley & Sons, Ltd.
Observing copper chloride during dioxin formation using dispersive XAFS
Authors: Fujimori Takashi , Takaoka Masaki , Kato Kazuo , Oshita Kazuyuki , Takeda Nobuo
Published: March 2008

The incineration of municipal solid waste generates dioxins. To control dioxins, it is necessary to determine the mechanism of their formation. Because copper chloride (CuCl2) is one of the strongest catalysts of dioxin formation in fly ash, it is important to study the chemical changes of this compound. To determine the chemical changes of copper, Cu‐K x‐ray absorption near edge structure (XANES) spectra were examined during the heating of model fly ash using a time‐resolved dispersive x‐ray absorption fine structure (DXAFS) technique. The change in the absorption edge of the Cu‐K XANES spectrum revealed a change in the valence of copper and the temperature dependence of the reduction and oxidation of CuCl2. From room temperature to 270 °C, CuCl2 was reduced, and from > 270 to 300 °C, copper was reoxidized in the presence of 10% oxygen. At a constant temperature of 210 or 300 °C, copper was dynamically reduced and oxidized. In experiments using different gas streams, HCl gas had no effect on the reaction of copper, while oxygen gas was essential for the reoxidation of copper. Our results suggest that dioxin formation in fly ash occurs via the chlorination of carbon with the reduction of CuCl2 and carbon gasification catalyzed by copper oxides. Copyright © 2008 John Wiley & Sons, Ltd.
Mental health of patients from different cultures in Germany
Authors: Wittig U. , Lindert J. , Merbach M. , Brähler E.
Published: March 2008

Background

Empirical studies on migration and mental health of migrants are still rare. In Germany they are often characterised by low sample sizes and are limited to certain diseases and geographical areas (old federal states). The comparability of their results is limited. Nonetheless, the assessment of migrants’ health is necessary for adequate medical and psychosocial care for this target group.

Aim

To provide data on mental health of migrants from Poland and from Vietnam in Germany. Methods: We have assessed a random sample of migrants from Poland (n=140) and from Vietnam (n=88) using the Giessen Subjective Complaints List – 24 (GSCL-24) and the Hospital Anxiety and Depression Scale (HADS). Additionally we asked migrants about their knowledge of health care institutions in case of psychosocial problems, their demands and the existing barriers to health care utilisation.

Results

Migrants from Poland and Vietnam have a higher general score of complaints of physical ill-health and higher anxiety and depression values than Germans. Psychosocial and medical institutions are visited less.

Conclusion

Further analytical studies are needed to clarify health differences between these groups. Migrants are a heterogeneous group and only group-specific investigations will clarify associations between countries of origin, health status and use of health care institutions.