bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of peptides from human pathogens able to cross‐activate an HIV‐1‐gag‐specific CD4+ T cell clone
Authors: Venturini Sara , Allicotti Gina , Zhao Yindong , Simon Richard , Burton Dennis R. , Pinilla Clemencia , Poignard Pascal
Published: December 2005

Antigen recognition by T cells is degenerate both at the MHC and the TCR level. In this study, we analyzed the cross‐reactivity of a human HIV‐1 gag p24‐specific CD4+ T cell clone obtained from an HIV‐1‐seronegative donor using a positional scanning synthetic combinatorial peptide library (PS‐SCL)‐based biometrical analysis. A number of decapeptides able to activate the HIV‐1 gag‐specific clone were identified and shown to correspond to sequences found in other human pathogens. Two of these peptides activated the T cell clone with the same stimulatory potency as the original HIV‐1 gag p24 peptide. These findings show that an HIV‐1‐specific human T helper clone can react efficiently with peptides from other pathogens and suggest that cellular immune responses identified as being specific for one human pathogen (HIV‐1) could arise from exposure to other pathogens.
Nickel potentiates the genotoxic effect of benzo[a]pyrene in Chinese hamster lung V79 cells
Authors: Deng Cheng Z. , Fons Michael P. , Rosenblatt Judah , El‐Zein Randa A. , Abdel‐Rahman Sherif Z. , Albrecht Thomas
Published: December 2005

The modulating effect of acute exposure to NiCl2 on the induction of chromosome aberrations by a model carcinogen, benzo[a]pyrene (B[a]P), was examined in Chinese hamster V79 lung cells. At concentrations up to 20 μg/ml (84.2 μM), NiCl2 did not significantly increase the frequency of chromosome aberrations in V79 cells when the cells were exposed concomitantly to 0.5 μg/ml B[a]P. Addition of the S15 liver microsomal fraction together with the B[a]P did not alter the results. Addition of NiCl2 2 hr before treatment of cells with 0.5 μg/ml B[a]P also did not result in a significant elevation of the frequency of chromosome aberrations, even at NiCl2 concentrations as high as 20 μg/ml. Contrasting sharply with these findings, when V79 cells were treated with NiCl2 immediately after B[a]P exposure, a significant increase in the frequency of chromosome damage was observed at NiCl2 concentrations as low as 5 μg/ml (21.1 μM). NiCl2‐mediated enhancement of chromosome damage was also observed when V79 cells were exposed to the reactive B[a]P intermediate, benzo[a]pyrene–r−7,t−8‐dihydrodiol‐t−9,10‐epoxide (BPDE). In the BPDE‐treated cells, the level of NiCl2‐mediated enhancement was similar to that observed with the tumor promoter 12‐o‐tetradecanoylphorbol‐13‐acetate (TPA, 100 ng/ml). These results are consistent with the view that the effect of nickel (II) on B[a]P‐induced genetic damage is dependent on the relative times of exposure to Ni2+ and B[a]P. NiCl2 did not enhance the frequency of chromosome aberrations induced by Chromium (VI), regardless of the order of addition of the chemicals to the V79 cells. These results suggest that nickel may act as a promoter of chemically‐induced genetic damage through induction of error‐prone repair. Environ. Mol. Mutagen., 2006. © 2005 Wiley‐Liss, Inc.
Application of the multidimensional positive definite advection transport algorithm (MPDATA) to environmental modelling on adaptive unstructured grids
Authors: Ahmad Nash'at N. , Bacon David P. , Hall Mary S. , Sarma Ananthakrishna
Published: December 2005

Twenty years ago, the multidimensional, positive definite, advection transport algorithm was introduced by Smolarkiewicz. Over the two decades since, it has been applied countless times to numerous problems, however almost always on rectilinear grids. One of the few exceptions is the Operational Multiscale Environment model with Grid Adaptivity (OMEGA), an atmospheric simulation system originally designed to simulate atmospheric dispersion in the planetary boundary layer, but since then used for both mesoscale (from meso‐α to meso‐γ) dispersion and weather forecasting. One of the unique aspects of OMEGA is the triangular unstructured grid geometry which leads in a natural way to the creation of a global grid with continuously variable resolution from roughly 100 km over the oceans to less than 10 km over regions of interest. Another unique aspect is the concept of dynamically adapting grid resolution—sometimes also called solution‐adaptive grid resolution. A central element of the modelling system, however, is its advection solver—MPDATA. This paper presents the implementation of MPDATA on an unstructured grid and demonstrates its accuracy and efficiency using analytic and idealized test cases. Copyright © 2005 John Wiley & Sons, Ltd.
A systematic review of the clinical effectiveness of donepezil, rivastigmine and galantamine on cognition, quality of life and adverse events in Alzheimer's disease
Authors: Takeda A. , Loveman E. , Clegg A. , Kirby J. , Picot J. , Payne E. , Green C.
Published: December 2005

Background

The use of cholinesterase inhibiors for Alzheimer's disease (AD) is currently being appraised by the National Institute for Clintical Evidence (NICE). This article provides the latest evidence that NICE will be using as part of this appraisal process.

Objective

To provide a systematic review of the best quality evidence of the effects of donepezil, rivastigmine and galantamine on cognition, quality of life and adverse events in people with mild to moderately‐severe AD.

Design

Electronic databases were searched, references of all retrieved articles were checked, and experts were contacted for advice, peer review and to identify additional references. Randomised controlled trials (RCTs) were included if they fulfilled pre‐specified criteria. Data were synthesised through a narrative review.

Results

Twenty‐six RCTs that compared any one of the cholinesterase inhibitors with either a control group or with another cholinesterase inhibitor were included. The quality of reporting and methodology was varied. Treatment with donepezil, rivastigmine or galantamine resulted in significantly better cognitive performance using the ADAS‐cog scale when compared with placebo. These findings were generally supported using the MMSE scale. Results from head to head comparisons were limited by the low number of studies and the study quality; generally showing no robust support for any one drug. Few studies evaluated quality of life. Adverse events were generally related to the gastrointestinal system, with a tendency for these to be more common in the treatment arms.

Conclusions

The cholinesterase inhibitors donepezil, rivastigmine, and galantamine can delay cognitive impairment in patients with mild to moderately‐severe AD for at least 6 months duration. Copyright © 2005 John Wiley & Sons, Ltd.
Prognosis of late life depression: a three‐year cohort study of outcome and potential predictors
Authors: Baldwin Robert C. , Gallagley Andrew , Gourlay Mhairi , Jackson Alan , Burns Alistair
Published: December 2005

Background

Late‐onset depression (LOD) has a poor prognosis which may be worsened by the presence of cerebrovascular disease. Few studies have explored prospectively the influence of vascular risk factors on longer term prognosis.

Methods

The original study involved 50 patients with LOD and 35 healthy age matched controls. Follow‐up was at three years. Baseline measures included clinical, neuroradiological and neuropsychological variables. Outcome was assessed by mortality, progression to dementia and clinical course of depressive disorder.

Results

Sixty‐two (73%) of the original cohort agreed to be re‐interviewed. Seven participants had died (all from the depressed group) and six developed dementia, all but one from the depressed group. Vascular dementia predominated (although not significantly so) among those with dementia at follow‐up. For 28 depressed patients with complete follow‐up data (56% of the original sample), poor outcome was predicted by lower High Density Lipoprotein (HDL), raised Erythrocyte Sedimentation Rate (ESR) and a higher score on the Hachinski Index scale and one test of immediate memory. Initial response to treatment was not associated with later outcome.

Conclusion

Late‐onset depressive disorder is associated with a high rate of mortality and possibly dementia. Biochemical and inflammatory markers may be important in prognosis and their role should be confirmed in future studies. Copyright © 2005 John Wiley & Sons, Ltd.
A community study on emotional distress among Arab and Jewish Israelis over the age of 60
Authors: Shemesh Annarosa Anat , Kohn Robert , Blumstein Tzvia , Geraisy Nabil , Novikov Ilya , Levav Itzhak
Published: December 2005

Background

The elderly constitute a vulnerable group for psychopathology, yet research on their mental health among both Arab and Jews in Israel remains limited. The same is the case in Arab countries. This paper reports on the contrasting distribution of the mean emotional distress (ED) scores and rates of suspected clinical cases, and their related risk factors, among community residents over the age of 60.

Methods

Several national agencies conducted a survey on 5,055 elderly individuals to investigate their health status, including ED. The interview included socio‐demographic and behavioral health items, as well as a modified 12 item‐GHQ as a measure of ED. Total ED scores and prevalence rates for suspected psychopathology were calculated. Their respective risk factors were examined using univariate and multivariate methods.

Results

The ED scores were highest among Muslim Arabs (4.9), followed by Christian Arabs (4.2), Jews (3.1) and Druzes (2.8). Their estimated prevalence rates were 43.4%, 37.0%, 21.4%, and 17.0%, respectively. The gradient of these results remained unchanged in the multivariate analysis for ED scores adjusting for confounding variables. In contrast, logistic regression analysis controlling for confounding variables did not find a differential risk for suspected psychopathology between Arabs and Jews.

Conclusion

Conceivably, the higher demoralization scores among elderly Arabs are associated with their minority status affiliation, as well as with the rapid social changes that have taken place in their midst. A cultural response style may be entertained as a possible explanation. However, these factors do not impact the risk for suspected psychopathology where no differential risk was noted after adjustments for confounders. Copyright © 2005 John Wiley & Sons, Ltd.
Long‐term serotonin administration leads to higher bone mineral density, affects bone architecture, and leads to higher femoral bone stiffness in rats
Authors: Gustafsson Björn I. , Westbroek Irene , Waarsing Jan H. , Waldum Helge , Solligård Erik , Brunsvik Anders , Dimmen Sigbjørn , van Leeuwen Johannes P.T.M. , Weinans Harrie , Syversen Unni
Published: December 2005

New evidence suggests a control of bone mass by the central nervous system. We have previously shown that functional serotonin receptors are present in bone cells and that serotonin stimulates proliferation of osteoblast precursor cells in vitro. In the present study we investigated the effects of serotonin on bone tissue in vivo. Ten, 2‐month‐old female Sprague–Dawley rats were injected with serotonin subcutaneously (s.c.) (5 mg/kg) once daily for 3 months, controls received saline. Using microdialysis and HPLC, free circulating serotonin levels were measured. DXA scans were made after 3 months of serotonin administration. Bone architecture and mechanical properties were investigated by micro‐computed tomography (µCT), histomorphometry, and mechanical testing. A long‐lasting hyperserotoninemia with a >10‐fold increase in serotonin appeared. Total body BMD was significantly higher (0.1976 ± 0.0015 vs. 0.1913 ± 0.0012 g/cm2) in rats receiving serotonin. Cortical thickness (Ct.Th) measured by µCT analysis was also higher, whereas trabecular bone volume (BV) was lower. Interestingly, the perimeter and cross‐sectional moment of inertia (MOI), a proxy for geometrical bone strength, were the same in both groups. These data suggest that serotonin reduces resorption or/and increases apposition of endosteal bone. Mechanical testing showed that femoral stiffness was higher in serotonin‐dosed animals. The energy absorption also seemed slightly, but not significantly higher. In conclusion, hyperserotoninemia led to a higher BMD, altered bone architecture and higher femural bone stiffness in growing rats, demonstrating that serotonin may have important effects on bone in vivo. J. Cell. Biochem. 97: 1283–1291, 2006. © 2005 Wiley‐Liss, Inc.
Retinoic acid‐induced CD38 expression in HL‐60 myeloblastic leukemia cells regulates cell differentiation or viability depending on expression levels
Authors: Lamkin Thomas J. , Chin Vivian , Varvayanis Susi , Smith James L. , Sramkoski R. Michael , Jacobberger James W. , Yen Andrew
Published: December 2005

Retinoic acid‐induced expression of the CD38 ectoenzyme receptor in HL‐60 human myeloblastic leukemia cells is regulated by RARα and RXR, and enhanced or prevented cell differentiation depending on the level of expression per cell. RARα activation caused CD38 expression, as did RXR activation but not as effectively. Inhibition of MAPK signaling through MEK inhibition diminished the induced expression by both RARs and RXRs. Expression of CD38 enhanced retinoic acid‐induced myeloid differentiation and G0 cell cycle arrest, but at higher expression levels, induced differentiation was blocked and retinoic acid induced a loss of cell viability instead. In the case of 1,25‐dihydroxyvitamin D3, induced monocytic differentiation was also enhanced by CD38 and not enhanced by higher expression levels, but without induced loss of viability. Expression levels of CD38 thus regulated the cellular response to retinoic acid, either propelling cell differentiation or loss of viability. The cellular effects of CD38 thus depend on its expression level. J. Cell. Biochem. 97: 1328–1338, 2006. © 2005 Wiley‐Liss, Inc.
Improved R2* measurements in myocardial iron overload
Authors: Ghugre Nilesh R. , Enriquez Cathleen M. , Coates Thomas D. , Nelson Marvin D. , Wood John C.
Published: December 2005

Purpose

To optimize R2*(1/T2*) measurements for cardiac iron detection in sickle cell and thalassemia patients.

Materials and Methods

We studied 31 patients with transfusion‐dependent sickle cell disease and 48 patients with thalassemia major; myocardial R2* was assessed in a single midpapillary slice using a gated gradient‐echo pulse sequence. Pixel‐wise maps were coregistered among the patients to determine systematic spatial fluctuations in R2*. The contributions of minimum TE, echo spacing, signal‐decay model, and region‐of‐interest (ROI) choice were compared in synthetic and acquired images.

Results

Cardiac relaxivity demonstrated characteristic circumferential variations regardless of the degree of iron overload. Within the interventricular septum, a gradient in R2* from right to left ventricle was noted at high values. Pixel‐wise and ROI techniques yielded nearly identical values. Signal decay was exponential but a constant offset or second exponential term was necessary to avoid underestimation at high iron concentration. Systematic underestimation of R2* was observed for higher minimum TE, limiting the range of iron concentrations that can be profiled. Fat‐water oscillations, although detectable, represented only 1% of the total signal.

Conclusion

Clinical cardiac R2* measurements should be restricted to the interventricular septum and should have a minimum TE ≤ 2 msec. ROI analysis techniques are accurate; however, offset‐correction is essential. J. Magn. Reson. Imaging 2006. © 2005 Wiley‐Liss, Inc.
Sorption of ethyl acetate and d‐limonene in poly(lactide) polymers
Authors: Auras Rafael , Harte Bruce , Selke Susan
Published: December 2005

Poly(lactide) (PLA) polymers have garnered increased attention in the last few years as food packaging materials because they are environmentally friendly polymers. As the production of PLA increases and price per pound drops, PLA is becoming a growing alternative as a green food packaging material. In this research, the organic vapor barrier properties of commercially available PLA polymers were studied. Gravimetric sorption tests in PLA films were carried out, and the diffusion (D), solubility (S) and permeability (P) coefficients for ethyl acetate and d‐limonene in PLA were determined. For ethyl acetate, values of P = 1.22 × 10−17 kg m m−2 s−1 Pa−1, D = 2.63 × 10−15 m2 s−1, and S = 4.62 × 10−3 kg m−3 Pa−1) at 45 °C and a partial pressure of 12 654 Pa were obtained. For d‐limonene, no trace was detected after 21 days of testing at 45 °C and 258 Pa, which indicates a permeability coefficient lower than 9.96 × 10−21 kg m m−2 s−1 Pa−1. Poly(lactide) polymers demonstrated good aroma barrier to ethyl acetate and d‐limonene, and will most likely be good aroma barriers. PLA is not likely to promote flavor loss by either permeation or scalping. Copyright © 2005 Society of Chemical Industry
Solution structures and behavior of trans‐RuH(η1‐BH4) (binap)(1,2‐diamine) complexes
Authors: Sandoval Christian A. , Yamaguchi Yoshiki , Ohkuma Takeshi , Kato Koichi , Noyori Ryoji
Published: December 2005

The solution structures of a number of trans‐RuH(η1‐BH4)[(S)‐tolbinap](1,2‐diamine) precatalysts [TolBINAP = 2,2′‐bis(di‐4‐tolylphosphino)‐1,1′‐binaphthyl; 1,2‐diamine(S,S)‐ or (R,R)‐1,2‐diphenylethylenediamine (DPEN), ethylenediamine (EN), and (S)‐1,1‐di(4‐anisyl)‐2‐isopropylethylenediamine (DAIPEN)] have been determined using 2D NMR (1H1H DQF‐COSY, 1H13C HMQC, 1H31P HSQC, and 1H15N HSQC), and a double‐pulsed field‐gradient spin‐echo (DPFGSE) NOE technique. All the octahedral Ru complexes adopt a trans configuration with respect to the BH4 and hydride ligands. Amine protons of trans‐RuH(η1‐BH4)[(S)‐tolbinap](1,2‐diamine) complexes undergo H/D exchange in (CD3)2CDOD. This inherent high acidity, coupled with the lability and chemical properties of the BH4 ligand, allows for precatalyst activation without the need for an added base, in contrast to trans‐RuCl2[(S)‐tolbinap](1,2‐diamine) precatalysts, which require a strong base for generation of a catalytic species. The H/BH4 complex in a 2‐propanol solution is converted to catalytically active [trans‐RuH{(S)‐tolbinap}{(S,S)‐dpen}(ROH)]+ [(RO)(ROH)n]− (R = (CH3)2CH), a loosely associated ion pair of the discrete (solvated) cationic fragment and anionic species. Copyright © 2006 John Wiley & Sons, Ltd.
The design of a multi‐dimensional LC‐SPE‐NMR system (LC2‐SPE‐NMR) for complex mixture analysis
Authors: Alexander A. J. , Xu F. , Bernard C.
Published: December 2005

In this communication, we describe the design of an online multi‐chromatographic approach to the routine NMR analyses of low‐level components (∼0.1%) in complex mixtures. The technique, termed LC2‐SPE‐NMR, optimally combines multi‐dimensional liquid chromatography with SPE technology for isolating, enriching and delivering trace analytes to the NMR probe. The fully automated LC2‐SPE‐NMR system allows for maximal loading capacity (in the first, preparative LC dimension), close to optimal peak resolution (in the second, analytical LC dimension) and enhanced sample concentration (through SPE). Using this system, it is feasible to conveniently conduct a wide range of NMR experiments on, for example, drug impurities at the low microgram per milliliter level, even for components poorly resolved in the first dimension. Such a sensitivity gain significantly elevates the analytical power of online NMR technology in terms of the level at which substances of pharmaceutical significance can be structurally characterized. Copyright © 2006 John Wiley & Sons, Ltd.
Multiscale approach to investigate the radiochemical degradation of epoxy resins under high‐energy electron‐beam irradiation
Authors: Longiéras N. , Sebban M. , Palmas P. , Rivaton A. , Gardette J. L.
Published: December 2005

A multiscale investigation of the degradation mechanism of two epoxy systems exposed to electron‐beam irradiation under a helium atmosphere was carried out with a variety of analytical methods, including high‐resolution solution‐ and solid‐state NMR spectroscopy, NMR relaxometry, infrared spectroscopy, sterical exclusion chromatography, and differential scanning calorimetry. As a first step, we studied a linear phenoxy polymer, poly(2‐hydroxyether of bisphenol A), which provided a basis for the investigation of the degradation of a more complex, insoluble epoxy–amine network, diglycidyl ether of bisphenol A/triethylene tetramine. Among different structural modifications, the main degradation process was shown to produce in both cases a chain scission. For the phenoxy resin, the hydroxypropylidene moiety was identified as the fragile site leading to the formation of two phenolic chain ends and acetone and isopropyl alcohol as low‐molecular‐weight products. All methods, ranging from molecular to supramolecular scales, were shown to correlate both qualitatively and quantitatively. Experimental results obtained with diglycidyl ether of bisphenol A/triethylene tetramine evidenced a different degradation scheme occurring at the ethylene amine part and producing a dangling vinyl amine as the major degradation product. A selective increase in the molecular mobility at this site was confirmed by a two‐dimensional, local‐field wide‐line separation experiment. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 865–887, 2006
Copper‐based supported catalysts for the atom transfer radical polymerization of methyl methacrylate: How can activity and control be tuned up?
Authors: Duquesne Emmanuel , Labruyère Céline , Habimana Jean , Degée Philippe , Dubois Philippe
Published: December 2005

This article is aimed at revisiting the synthesis of copper‐based catalysts immobilized onto crosslinked polystyrene (PS) resins carrying pyridinimine groups (PS–pyridinimine/CuBr). These supported catalytic systems were used for promoting the atom transfer radical polymerization of methyl methacrylate as initiated by ethyl‐2‐bromoisobutyrate. It was evidenced that the control over the polymerization reaction was strongly influenced by the coordination ability and extent of the transition‐metal salt on the supported pyridinimine ligands. For instance, increasing the ligand‐to‐catalyst molar ratio allowed for increasing the polymerization rate and improving the control over the molecular parameters of the synthesized poly(methyl)methacrylate (PMMA) in terms of the molar masses and molecular weight distributions. The PS–pyridinimine/CuBr supported catalyst was recycled and reused for further polymerization reactions. After two recycling steps, the reaction activity appeared to be preserved, and the control was improved in terms of the initiation efficiency. However, a slight increase in the polydispersity indices was observed. Interestingly, the introduction of a flexible polydimethylsiloxane spacer between the PS support and the catalytic sites led to some more improvement of the control over the molecular parameters of PMMA chains, which displayed narrower molecular weight distributions. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 744–756, 2006
Reversible addition–fragmentation chain transfer graft copolymerization of styrene and m‐isopropenyl‐α,α′‐dimethylbenzyl isocyanate from polypropylene lanterns: Solid phases for scavenging applications
Authors: Barner Leonie , Perera Senake , Sandanayake Sam , Davis Thomas P.
Published: December 2005

The γ‐initiated reversible addition–fragmentation chain transfer mediated free‐radical graft copolymerization of styrene and m‐isopropenyl‐α,α′‐dimethylbenzyl isocyanate (TMI) from a polypropylene (PP) solid phase was performed with cumyl phenyldithioacetate (CPDA) as the chain‐transfer agent. The initial CPDA concentration was 8 × 10−3 mol L−1. Polymerizations were performed with a dose rate of 0.18 kGy h−1 at the ambient temperature. Initial comonomer mixtures with 15, 30, and 50 mol % TMI were used. Depending on the amount of TMI in the initial comonomer mixture, the plot of the grafting ratio versus the time showed two grafting regimes (for 15 and 50 mol % TMI) or one (for 30 mol % TMI). Scavenger lanterns with 15 and 50 mol % TMI featured two isocyanate loading regimes, the second with higher loading capacities. The scavenger lanterns with 30 mol % TMI showed a linear loading capacity over the full grafting ratio. A maximum loading capacity of 110 μmol per scavenger lantern was achieved with 50 mol % TMI at a grafting ratio of approximately 60 wt %. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 857–864, 2006
Free energy surfaces of miniproteins with a ββα motif: Replica exchange molecular dynamics simulation with an implicit solvation model
Authors: Jang Soonmin , Kim Eunae , Pak Youngshang
Published: December 2005

Designed miniproteins with a ββα motif, such as BBA5, 1FSD, and 1PSV can serve as a benchmark set to test the validity of all‐atom force fields with computer simulation, because they contain all the basic structural elements in protein folding. Unfortunately, it was found that the standard all‐atom force fields with the generalized Born (GB) implicit solvation model tend to produce distorted free energy surfaces for the ββα proteins, not only because energetically those proteins need to be described by more balanced weights of the α‐ and β‐strands, but also because the GB implicit solvation model suffers from overestimated salt bridge effects. In an attempt to resolve these problems, we have modified one of the standard all‐atom force fields in conjunction with the GB model, such that each native state of the ββα proteins is in its free energy minimum state with reasonable energy barriers separating local minima. With this modified energy model, the free energy contour map in each protein was constructed from the replica exchange molecular dynamics REMD simulation. The resulting free energy surfaces are significantly improved in comparison with previous simulation results and consistent with general views on small protein folding behaviors with realistic topology and energetics of all three proteins. Proteins 2006. © 2005 Wiley‐Liss, Inc.
Magnetic and superconducting correlations in the two‐dimensional Hubbard model
Authors: Metzner W. , Reiss J. , Rohe D.
Published: December 2005

The interplay and competition of magnetic and superconducting correlations in the weakly interacting two‐dimensional Hubbard Model is investigated by means of the functional renormalization group. At zero temperature the flow of interactions in one‐loop approximation evolves into a strong coupling regime at low energy scales, signalling the possible onset of spontaneous symmetry breaking. This is further analyzed by a mean‐field treatment of the strong renormalized interactions which takes into account magnetic and superconducting order simultaneously. The effect of strong correlations on single‐particle properties in the normal phase is studied by calculating the flow of the self‐energy. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transport energy in disordered organic materials
Authors: Novikov Sergey V. , Malliaras George G.
Published: December 2005

Applicability of the concept of the transport energy to charge carrier transport in disordered organic materials has been reexamined. We showed that because of a strong spatial correlation in the distribution of the site energies in organic materials the transport energy does not exist. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Fragment‐weighted Key‐based Similarity Measure for Use in Structural Clustering and Virtual Screening
Authors: Munk Jørgensen Anne Marie , Langgård Morten , Gundertofte Klaus , Pedersen Jan Torleif
Published: December 2005

A new similarity measure and structural clustering method has been developed in which each structure is fragmented into ring systems, linkers, and side chains, and where the similarity between structures forms a weighted sum of the similarities between each set of fragments. We have applied the MACCS keys as molecular descriptors and identified a number of ways in which to improve the use of these keys for structural clustering and virtual screening. The method has been optimized to reproduce scaffold‐biased clustering commonly used in medicinal chemistry.
Multiple Linear Regression and Principal Component Analysis‐Based Prediction of the Anti‐Tuberculosis Activity of Some 2‐aryl‐1,3,4‐Thiadiazole Derivatives
Authors: Hemmateenejad B. , Miri R. , Jafarpour M. , Tabarzad M. , Foroumadi A.
Published: December 2005

The search for novel antibacterial agents active against Mycobacterium tuberculosis and other atypical Mycobacterium is urgent due to the lack of effectiveness of known anti‐tuberculosis agents against opportunistic pathogens as a consequence of rapidly emerging resistance. In this study, QSAR analysis was conducted on the anti‐tuberculosis activity of some newly synthesized 2‐aryl‐1,3,4‐Thiadiazole derivatives. Different set of molecular descriptors were calculated to predict the anti‐tuberculosis activity of a set of 27 thiadiazole derivatives using the multiple linear regression (MLR), Free‐Wilson analysis (FWA) and principal component analysis (PCA) methods. Successful MLR equations were obtained from a pool of topological, constitutional, quantum chemical and entire set of descriptors. They could predict the activity of all of the molecules, except one derivative, accurately. The equations obtained from the functional groups and chemical descriptors had lower accuracy and produced two and three outliers, respectively. In the PCA, different patterns of distributions were obtained by plotting the first three scores of the descriptors data matrices against each other. Better classification patterns were obtained when PCA was performed on the subset of descriptors in relative to all of the calculated descriptors. In this case, the active and inactive molecules were classified into distinct clusters with exception one active molecules, which classified as inactive.
Effects of weathering on in situ portable X‐ray fluorescence analyses of geological outcrops: dolerite and rhyolite outcrops from the Preseli Mountains, South Wales
Authors: Potts P. J. , Bernardini F. , Jones M. C. , Williams‐Thorpe O. , Webb P. C.
Published: December 2005

Laboratory experiments were undertaken to investigate the effect of weathering on dolerite and rhyolite samples from the Preseli Mountains, South Wales, an area of archaeological significance for the provenancing of archaeological artefacts. Portable XRF (PXRF) analysis was used to construct a depth profile of elemental concentrations through the weathering layer of suitable rock samples. These measurements were made by sequentially grinding away successive layers, each time measuring the newly exposed surface by PXRF. The elements studied included K, Ca, Ti, Mn, Fe, Ba, Nb, Pb, Sr, Y and Zr. In dolerite samples, Ca, Fe and Y were generally depleted in heavily weathered surface layers, whereas K and Pb were enhanced, the latter element significantly so, probably as a result of anthropogenic activities (emissions from leaded automobile fuel). Element behaviour in rhyolites was less consistent. A correction factor was derived for each element based on the ratio of the weathered surface concentration to the corresponding steady‐state (fresh rock) concentration beneath the altered layer. This correction factor was evaluated as a possible means of compensating for elemental discrepancies when measuring weathered surfaces. Improved data were obtained for a significant number of elements, but further work is required to evaluate this procedure fully. Copyright © 2005 John Wiley & Sons, Ltd.
Peroperative ketamine and morphine for postoperative pain control after lumbar disk surgery
Authors: Aveline Christophe , Le Hetet Hubert , Vautier Pierre , Gautier Jean François , Bonnet Francis
Published: December 2005

Background Ketamine, a N‐methyl‐d‐aspartate receptor antagonist, may reduce postoperative opioid demand and improve postoperative analgesia.

Methods Sixty‐nine patients scheduled for lumbar disk surgery under general anaesthesia were enrolled in a randomised, double‐blind study comparing three analgesic combinations that were started before surgical incision: morphine 0.1 mg kg−1 alone (group M; n = 23); ketamine 0.15 mg kg−1 alone (group K; n = 22); and a combination of morphine 0.1 mg kg−1 with ketamine 0.15 mg kg−1 (group KM; n = 23). Postoperatively patient‐controlled analgesia was provided with intravenous morphine. Morphine consumption was assessed during 24 H, and pain scores were measured using a visual analogue scale (VAS) at rest and on mobilisation, during the first two postoperative days.

Results In group KM, less i.v. morphine was administered in the post anaesthesia care unit than in group M (median [range]: 0 mg [0–2] vs. 7 mg [6–9], P = 0.009). Cumulative 24 H morphine consumption was reduced by 57% in group KM vs. group M, and by 48% in group KM vs. group K. Postoperative VAS scores were lower in group KM vs. groups K and M. Maximal VAS score on mobilization was reduced in group KM compared to groups K and M (38 mm [35–45] vs. 52 mm [48–59] and vs. 59 mm [55–64], in groups KM, K and M, respectively, P = 0.05 and P = 0.002). The incidence of postoperative nausea and vomiting was decreased in group KM compared to group M (21.7% vs. 43.5%, P = 0.001).

Conclusion Ketamine small‐dose, combined with morphine improves postoperative analgesia and reduces opioid‐related side effects in lumbar disk surgery.
Cleavage mechanism of ATP‐dependent Lon protease toward ribosomal S2 protein
Authors: Nishii Wataru , Suzuki Taichiro , Nakada Mayumi , Kim Yong-Tae , Muramatsu Tomonari , Takahashi Kenji
Published: December 2005

The Escherichia coli ATP‐dependent protease Lon degrades ribosomal S2 protein in the presence of inorganic polyphosphate (polyP). In this study, the process of the degradation was investigated in detail. During the degradation, 68 peptides with various sizes (4–29 residues) were produced in a processive fashion. Cleavage occurred at 45 sites, whose P1 and P3 positions were dominantly occupied by hydrophobic residues. These cleavage sites were located preferentially at the regions with rigid secondary structures and the P1 residues of the major cleavage sites appeared to be concealed from the surface of the substrate molecule. Furthermore, polyP changed not only the substrate preference but also the oligomeric structure of the enzyme.
Modeling the highly specific ribotoxin recognition of ribosomes
Authors: García-Mayoral Flor , García-Ortega Lucía , Álvarez-García Elisa , Bruix Marta , Gavilanes José G. , Martínez del Pozo Álvaro
Published: December 2005

The three‐dimensional structures of the α‐sarcin ribotoxin and its Δ(7–22) deletion mutant, both complexed with a 20‐mer oligonucleotide mimicking the sarcin/ricin loop (SRL) of the ribosome, have been docked into the structure of the Halobacterium marismortui ribosome by fitting the nucleotide atomic coordinates into those of the ribosomal SRL. This study has revealed that two regions of the ribotoxin, residues 11–16 and 84–85, contact the ribosomal proteins L14 (residues 99–105) and L6 (residues 88–92), respectively. The first of these two ribotoxin regions appears to be crucial for its specific ribosome recognition.
Ethanol rapidly causes activation of JNK associated with ER stress under inhibition of ADH
Authors: Nishitani Yoko , Matsumoto Hiroshi
Published: December 2005

Acute ethanol loading causes oxidative stress to activate cell‐death signaling via c‐Jun NH2‐terminal kinase (JNK) in livers. JNK are stimulated under conditions of endoplasmic reticulum (ER) stress which causes programmed cell death. However, no remarked cell death was observed in acute ethanol intoxication. Akt, one of the cell survival protein kinases, may be activated under ethanol loading. The aim of this study was to estimate activation of JNK and ER stress, role of ethanol metabolism on the activation, and association of JNK with Akt under acute ethanol loading using the perfused rat liver system. Activation of JNK or Akt and association of JNK and Akt with JNK interacting protein 1 were estimated by immunoprecipitation and immunoblotting. Expression of 78 kDa glucose‐regulated protein (GRP78) mRNA, a biomarker of ER stress, was detected by quantitative real‐time RT‐PCR. Activations of JNK and Akt were enhanced by co‐treatment with ethanol and a classical inhibitor of alcohol dehydrogenase (ADH). Addition of an antioxidant reduced the activation of JNK. Ethanol loading with ADH inhibition causes down‐regulation of GRP78 mRNA levels. Therefore, these findings suggest first revelation that inhibition of ethanol metabolism complicates oxidative and ER stresses produced by ethanol.
Carbonylation of cornified envelopes in the stratum corneum
Authors: Hirao Tetsuji , Takahashi Motoji
Published: December 2005

Stratum corneum (SC), the outermost layer of the skin, is continuously exposed to oxidative stress via sunlight, lipid peroxidation, and is subsequently accompanied by oxidative modification. Previous studies have shown that major oxidative target proteins in the SC are keratins. However, it remains unclear to date whether cornified envelopes (CEs), protein envelopes of the corneocytes (cornified cells), would be oxidized. In this study, we first revealed oxidative modification of CEs using labeled hydrazide derivatives to detect carbonyl moieties. Carbonylation of CEs was confirmed by reaction with monoclonal antibodies against aldehyde‐bound proteins, including anti‐acrolein, anti‐crotonaldehyde, anti‐4‐hydroxy‐2‐nonenal. The extent of carbonylation is stronger in CEs from the face, a sun‐exposed area, than those from the inside of upper arm, an unexposed area. Carbonylation of CEs did not depend on their maturity, as evaluated by loss of involucrin antigenicity during maturation process, suggesting that CEs are carbonylated regardless of their maturation stage.
Pinpointing phosphotyrosine‐dependent interactions downstream of the collagen receptor DDR1
Authors: Koo Diana H.H. , McFadden Catherine , Huang Yun , Abdulhussein Rahim , Friese-Hamim Manja , Vogel Wolfgang F.
Published: December 2005

Using phosphopeptide mapping and site‐directed mutagenesis, we here identified multiple tyrosine phosphorylation sites within DDR1. We found that Nck2 and Shp‐2, two SH2 domain‐containing proteins, bind to DDR1 in a collagen‐dependent manner. The binding site of Shp‐2 was mapped to tyrosine‐740 of DDR1 within an ITIM‐consensus sequence. Lastly, ablation of DDR1 in the mouse mammary gland resulted in delocalized expression of Nck2, suggesting that defects observed during alveologenesis are caused by the lack of the DDR1–Nck2 interaction.
Different properties of SV channels in root vacuoles from near isogenic Al‐tolerant and Al‐sensitive wheat cultivars
Authors: Wherrett Tim , Shabala Sergey , Pottosin Igor
Published: December 2005

Patch‐clamp experiments revealed that near isogenic ET8 (Al‐tolerant) and ES8 (Al‐sensitive) wheat cultivars differed significantly in slow vacuolar channel properties. Under control conditions, whole vacuole currents displayed faster deactivation in ES8. Application of 1.4 μM vacuolar Al3+ caused a 20 mV increase in the activation threshold and slowed activation kinetics in ET8 but not in ES8. Channel density was about 30% higher in ES8 than ET8, and was not altered by 24 h aluminium pre‐treatment. However, the activation threshold was reduced in Al‐pre‐treated ES8. Overall, our data suggests that Alt1 locus may control more than the plasma membrane malate channel in wheat.
Nitric oxide regulates the proliferation of chick embryo retina cells by a cyclic GMP‐independent mechanism
Authors: Magalhães Cristiane R. , Socodato Renato E.S. , Paes‐de‐Carvalho Roberto
Published: December 2005

Nitric oxide (NO) is an intercellular messenger involved in many physiological and pathological processes of vertebrate and invertebrate animal tissues. In the embryonic chick retina, nitric oxide synthase (NOS) activity and a system for l‐arginine transport between neurons and glial cells were described, supporting the idea that nitric oxide is a critical molecule during retinal development. In the present work we show that nitric oxide is a modulator of cell proliferation in chick embryo retina. Mixed cultures of retinal neurons and glial cells were submitted to [3H]‐thymidine incorporation after drug treatment. Incubation for 24 h with the NO donors S‐nitroso‐N‐acetyl‐penicillamine (SNAP) or Spermine nitric oxide (SpNO) complex promoted a decrease of approximately 70% of [3H]‐thymidine incorporation in a dose‐dependent manner. SNAP did not increase Lactate dehydrogenase release and its effect was not mimicked by 8‐bromo cyclic GMP, or blocked by the guanylate cyclase inhibitor 1H‐[1,2,4]oxadiazole[4,3‐a]quinoxalin‐1‐one (ODQ), indicating that the effect was not due to cell death or mediated by increases of cyclic GMP levels. The inhibition was completely prevented by dithiotreitol (DTT), strongly indicating the participation of an S‐nitrosylation mechanism. SNAP blocked the increase of [3H]‐thymidine incorporation induced by ATP. Using purified cultures of glial cells we showed that the NO donor SNAP produced an inhibition of 50% in cell proliferation and did stimulate ERK1/2 phosphorylation, indicating that the inhibition of this pathway was not involved in its cytostatic effect. [3H]‐Thymidine autoradiography of mixed cultures showed labeling of oval nuclei of glial flat cells. The injection of eggs with SNAP also did promote an intense inhibition of [3H]‐thymidine incorporation in retinas from 9‐day‐old embryos. These data suggest that nitric oxide affects the proliferation of chick embryo retina glial cells in culture or “in vivo” through cyclic GMP and ERK‐independent pathways.
Unusual histiocytic disease in a Somali cat
Authors: Reed Nicola , Begara-McGorum Isabel M. , Else Roderick W. , Gunn-Moore Danièlle A.
Published: December 2005

An 8-year-old Somali cat presented with a 9-month history of inappetence, vomiting and weight loss. The disease progressed to involve neurological signs associated with a mass lesion at the level of the first lumbar vertebra. Histopathology identified the condition as malignant histiocytosis affecting the lungs, stomach, mesenteric lymph nodes, liver, spleen, brain and spinal cord. However, the presentation of this case differs from previously reported cases of malignant histiocytosis, and may therefore represent a variant form of histiocytic disease.
CORE GROUPS AND THE TRANSMISSION OF HIV: LEARNING FROM MALE SEX WORKERS
Authors: PARKER MELISSA
Published: December 2005

A growing and substantial body of research suggests that female sex workers play a disproportionately large role in the transmission of HIV in many parts of the world, and they are often referred to as core groups by epidemiologists, mathematical modellers, clinicians and policymakers. Male sex workers, by contrast, have received little attention and it is not known whether it is helpful to conceptualize them as a core group. This paper draws upon ethnographic research documenting social and sexual networks in London and looks at the position of five male sex workers within a network comprising 193 men and seven women (as well as 1378 anonymous sexual contacts and 780 commercial contacts). In so doing, it suggests that there is no evidence to show that male sex workers are more or less likely to acquire or transmit HIV in the course of commercial sex compared with other types of sexual relationships. In addition, men engaging in non-commercial sex all reported having unprotected sex in a variety of contexts and relationships and there is no evidence to suggest that men who are not sex workers play less of a role in the transmission of HIV. In short, these data suggest that it would be inappropriate to conceptualize male sex workers as a core group. This is not to suggest that public policy should continue to overlook male sex workers. New and inventive approaches are required to reach out to a vulnerable but diverse group of men, selling sex for a variety of reasons; even if these men are no more vulnerable to acquiring and/or transmitting HIV than other men and women that form part of their network.
Energetic spanwise modes in the logarithmic layer of a turbulent boundary layer
Authors: TOMKINS C. D. , ADRIAN R. J.
Published: December 2005

The influence of large-scale outer-region motions on the properties and processes of the inner layer remains an open issue in wall turbulence research. In the present work, two-dimensional power spectra of the streamwise component are measured in streamwise-spanwise planes throughout the logarithmic region of smooth flat-plate turbulent boundary layers at $Re_\theta\,{=}\,1015$ and 7705. The spectra are based on PIV measurements with a wide spanwise view ($z/\delta\,{>}\, 2.5$), and the spanwise energy distribution is emphasized. The spectra reveal that the mode associated with the spacing of the low-speed streaks near the wall, $\lambda_z^+ \,{\approx}\, 100$, contains surprisingly little energy relative to modes in the range $\lambda_z^+ \,{\approx}\,$200–400 at $y^+ \,{=}\, 21$. This result is consistent with measurements in a channel flow (Liu et al. 1996) at a similar height. Further from the wall, large-scale structures that scale with outer variables organize with spacing $\lambda_z/\delta\,{=}\,$0.75–0.9, and these motions dominate the spanwise distribution of streamwise energy throughout the logarithmic region. The large spanwise modes are associated with the large streamwise modes on average, as the median energetic spanwise mode increases roughly linearly with increasing streamwise mode up to approximately $\lambda_{z,\mathrm{med}}/\delta \,{\approx}\, 0.8$, and then remains roughly constant for larger streamwise modes. The aspect ratio $\lambda_x / \lambda_{z,\mathrm{med}}$ decreases with increasing distance from the wall, suggesting that the most streaky structures remain buried near the wall.
Linear and nonlinear convection in solidifying ternary alloys
Authors: ANDERSON D. M. , SCHULZE T. P.
Published: December 2005

In this paper we consider buoyancy-driven flow and directional solidification of a ternary alloy in two dimensions. A steady flow can be established by forcing liquid downward at an average rate V through a temperature gradient that is fixed in the laboratory frame of reference and spans both the eutectic and liquidus temperature of the material being solidified. Our results include both a linear stability analysis and numerical solution of the governing equations for finite-amplitude steady states. The ternary system is characterized by two distinct mushy zones – a primary layer with dendrites composed of a single species and, beneath the primary layer, a secondary layer with a dendritic region composed of two species. The two layers have independent effective Rayleigh numbers, which allows for a variety of convection scenarios.
Magnetohydrodynamic damping of oscillations in low-Prandtl-number convection
Authors: HOF B. , JUEL A. , MULLIN T.
Published: December 2005

We present the results of an experimental investigation of the effect of a magnetic field on the stability of convection in a liquid metal. A rectangular container of gallium is subjected to a horizontal temperature gradient and a uniform magnetic field is applied separately in three directions. The magnetic field suppresses the oscillation most effectively when it is applied in the vertical direction and is least efficient when applied in the direction of the temperature gradient. The critical temperature difference required for the onset of oscillations is found to scale exponentially with the magnitude of the magnetic field for all three orientations. Comparisons are made with available theory and qualitative differences are discussed.