bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phospholipid Bilayers Supported on Thiolate‐Covered Nanostructured Gold: In Situ Raman Spectroscopy and Electrochemistry of Redox Species
Authors: Daza Millone M. Antonieta , Vela María E. , Salvarezza Roberto C. , Creczynski‐Pasa Tânia B. , Tognalli Nicolás G. , Fainstein Alejandro 
Published: July 2009

AbstractThiol‐covered nanostructured gold has been tested as a platform for the preparation of high‐area phospholipid bilayer systems suitable for optical and electrochemical sensing. In situ and ex situ Raman spectroscopy and electrochemical measurements are made to study methylene blue (MB) and flavin‐adenine dinucleotide (FAD) incorporation into dimyristoylphosphatidylcholine (DMPC) bilayers prepared by vesicle fusion on dithiothreitol (DTT)‐covered nanostructured gold. Results show that lipophilic positively charged MB molecules are incorporated in the bilayer reaching the DTT‐gold interface. On the other hand, the negatively charged FAD molecules are immobilized at the outer part of the phospholipid bilayer and cannot be electrochemically detected. Our results demonstrate that DTT‐covered nanostructured gold provides a suitable high‐area platform for phospholipid membranes that are able to separate and sense different kinds of molecules and biomolecules.
QASI, an international quality management system for CD4 T‐cell enumeration focused to make a global difference
Authors: Bergeron Michèle , Ding Tao , Houle Guy , Arès Linda , Chabot Christian , Soucy Nadia , Seely Peggy , Sherring Alice , Bogdanovic Dragica , Faucher Sylvie , Summers Randy , Somorjai Ray , Sandstrom Paul 
Published: July 2009

AbstractBackground:A significant worldwide mobilization effort to treat people with HIV disease began in 2003. Most guidelines for initiating antiretroviral therapy require reliable and reproducible CD4 T‐cell counting. Therefore, any effort that improves global availability of quality managed assessment schemes for CD4 T‐cell enumeration is a positive achievement for the clinical management of AIDS on a worldwide scale.Methods:The Canadian QASI‐Quality Management System (QMS) has been in operation for over a decade. More recently, QMS has fine‐tuned its strategy to optimize its global impact in the fight against the HIV/AIDS pandemic. Three modifications were implemented: (1) introduction of skills and knowledge transfer workshops pertaining to the initiation of national quality management programs for CD4 counting, (2) introduction of a road map to establish domestic EQAP for countries that are ready, and (3) introduction of a statistical analysis package which permits continuous monitoring of global impact of the QASI‐QMS.Results:Based on QASI‐QMS distribution of specimens over four consecutive participation cycles, there was decreased interlaboratory variation for both low and medium CD4 T‐cell levels. After three cycles of consecutive participation, there is an average of 38 and 26% error reduction reported for the mid and low CD4 levels, respectively.Conclusion:The program improvements mentioned earlier appear to have had a profound effect with regard to enhancing the performance of laboratories participating in the QASI‐QMS. Specifically, there is a significant reduction in interlaboratory variability of CD4 T‐cell counts resulting from continuous participation in the QASI‐QMS. © 2009 Clinical Cytometry Society
Synthesis and evaluation of micellar properties and antimicrobial activities of imidazole‐based surfactants
Authors: Kanjilal Sanjit , Sunitha Sadula , Reddy Paidimarla S. , Kumar Koochana P. , Murty Upadyayula S. N. , Prasad Rachapudi B. N. 
Published: July 2009

AbstractThe synthesis of two types of imidazole‐based surfactants, [(ROCOCH2MIm)Br] and [(RNHCOCH2MIm)Br], of varying chain lengths (C10, C12 and C16), was conducted in the present work. The synthesis involves an initial reaction of bromoacetic acid with fatty alcohols or fatty amines, followed by quaternization with N‐methyl imidazole. The micellar properties of all the synthesized compounds were determined using surface tensiometry and compared with [(RMIm)Br], a well‐studied alkyl‐substituted imidazole‐based surfactant. Within the same homologous series, a decrease in critical micelle concentration (cmc) was observed with increasing alkyl chain length in all three types of cationic surfactants. Introduction of an ester [(ROCOCH2MIm)Br] or an amide group [(RNHCOCH2MIm)Br] in the alkyl chain lowers the cmc when compared to a cationic surfactant without functional group, [(RMIm)Br]. The synthesized surfactants were also assayed for antimicrobial activities and found to possess good activities against selected strains.
Mutagen structure and transcriptional response: Induction of distinct transcriptional profiles in Salmonella TA100 by the drinking‐water mutagen MX and its homologues
Authors: Ward William O. , Swartz Carol D. , Hanley Nancy M. , Whitaker John W. , Franzén Robert , DeMarini David M. 
Published: July 2009

AbstractThe relationship between chemical structure and biological activity has been examined for various compounds and endpoints for decades. To explore this question relative to global gene expression, we performed microarray analysis of Salmonella TA100 after treatment under conditions of mutagenesis by the drinking‐water mutagen MX and two of its structural homologues, BA‐1, and BA‐4. Approximately 50% of the genes expressed differentially following MX treatment were unique to MX; the corresponding percentages for BA‐1 and BA‐4 were 91 and 80, respectively. Among these mutagens, there was no overlap of altered Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways or RegulonDB regulons. Among the 25 Comprehensive Microbial Resource functions altered by these mutagens, only four were altered by more than one mutagen. Thus, the three structural homologues produced distinctly different transcriptional profiles, with none having a single altered KEGG pathway in common. We tested whether structural similarity between a xenobiotic and endogenous metabolites could explain transcriptional changes. For the 830 intracellular metabolites in Salmonella that we examined, BA‐1 had a high degree of structural similarity to 2‐isopropylmaleate, which is the substrate for isopropylmalate isomerase. The transcription of the gene for this enzyme was suppressed twofold in BA‐1‐treated cells. Finally, the distinct transcriptional responses of the three structural homologues were not predicted by a set of phenotypic anchors, including mutagenic potency, cytotoxicity, mutation spectra, and physicochemical properties. Ultimately, explanations for varying transcriptional responses induced by compounds with similar structures await an improved understanding of the interactions between small molecules and the cellular machinery. Environ. Mol. Mutagen., 2010. Published 2009 Wiley‐Liss, Inc.
Basement controls on Acadian thrusting and fault reactivation along the southern margin of the Welsh Basin
Authors: Schofield D. I. , Aspden J. A. , Kemp S. J. , Merriman R. J. , Wilby P. R. 
Published: July 2009

AbstractInversion of the Lower Palaeozoic Welsh Basin during the Early to Mid‐Devonian is generally thought to have been achieved by a combination of approximately co‐axial shortening and transcurrent movement along major faults to produce a strongly partitioned transpressional strain. However, new field observations from Rhydwilym in southwest Wales reveal superimposed deformations which indicate that thrust tectonics operated within the Welsh Borderland Fault System (WBFS) along this segment of the basin margin. An increasing regional magnetic response towards the south suggests that contrasting depth to magnetic basement across the WBFS may have buttressed basin shortening and provided the focus for thrusting and late‐Caledonian or proto‐Variscan reactivation. British Geological Survey © Nerc 2009. All rights reserved.
Coffee intake is associated with lower rates of liver disease progression in chronic hepatitis C # ∥ ‡
Authors: Freedman Neal D. , Everhart James E. , Lindsay Karen L. , Ghany Marc G. , Curto Teresa M. , Shiffman Mitchell L. , Lee William M. , Lok Anna S. , Di Bisceglie Adrian M. , Bonkovsky Herbert L. , Hoefs John C. , Dienstag Jules L. , Morishima Chihiro , Abnet Christian C. , Sinha Rashmi 
Published: July 2009

Abstract
Higher coffee consumption has been associated inversely with the incidence of chronic liver disease in population studies. We examined the relationship of coffee consumption with liver disease progression in individuals with advanced hepatitis C–related liver disease. Baseline coffee and tea intake were assessed in 766 participants of the Hepatitis C Antiviral Long-Term Treatment against Cirrhosis (HALT-C) trial who had hepatitis C–related bridging fibrosis or cirrhosis on liver biopsy and failed to achieve a sustained virological response to peginterferon plus ribavirin treatment. Participants were followed for 3.8 years for clinical outcomes and, for those without cirrhosis, a 2-point increase in Ishak fibrosis score on protocol biopsies. At baseline, higher coffee consumption was associated with less severe steatosis on biopsy, lower serum aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio, alpha-fetoprotein, insulin, and homeostatic model assessment (HOMA2) score, and higher albumin (P < 0.05 for all). Two hundred thirty patients had outcomes. Outcome rates declined with increasing coffee intake: 11.1/100 person-years for none, 12.1 for less than 1 cup/day, 8.2 for 1 to fewer than 3 cups/day, and 6.3 for 3 or more cups/day (P-trend = 0.0011). Relative risks (95% confidence intervals) were 1.11 (0.76-1.61) for less than 1 cup/day; 0.70 (0.48-1.02) for 1 to fewer than 3 cups/day; and 0.47 (0.27-0.85) for 3 or more cups/day (P-trend = 0.0003) versus not drinking. Risk estimates did not vary by treatment assignment or cirrhosis status at baseline. Tea intake was not associated with outcomes. Conclusion: In a large prospective study of participants with advanced hepatitis C–related liver disease, regular coffee consumption was associated with lower rates of disease progression. (Hepatology 2009.)
Identification of androgen response elements in the enhancer I of hepatitis B virus: A mechanism for sex disparity in chronic hepatitis B #
Authors: Wang Sheng-Han , Yeh Shiou-Hwei , Lin Wei-Hsiang , Wang Hurng-Yi , Chen Ding-Shinn , Chen Pei-Jer 
Published: July 2009

Abstract
Hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) occurs more often in men than in women. Male HBV carriers usually have higher viral loads, which is a well-known risk factor for HCC. Whether and how the male androgen axis regulates HBV transcription and replication is investigated here. We used HBV transgenic mice to evaluate any sex disparity of serum hepatitis B surface antigen and HBV titers as well as the castration effect on this disparity. Compared to females, HBV transgenic male mice showed higher hepatitis B surface antigen and viral titers, which were lessened by castration of the males. In a cell culture system, HepG2 cells transfected with HBV and androgen receptor (AR) constructs were used to study the effect of the androgen pathway on viral transcription and replication. We found the ligand-stimulated AR could increase the transcription of HBV RNAs through its transcription activation domain. A genomic region within HBV enhancer I was identified that is responsible for the transcriptional activation of AR. The results from chromatin immunoprecipitation and in vitro binding assays further demonstrated a direct binding of AR to this region, in a ligand-dependent manner. Two androgen-responsive element motifs in this region were identified, and their mutations can significantly abolish the AR effects. Conclusion: This study demonstrated that the androgen pathway can increase the transcription of HBV through direct binding to the androgen-responsive element sites in viral enhancer I. This may explain a higher HBV titer in male carriers and an increased risk of HCC. (Hepatology 2009.)
Clinical optical coherence tomography combined with multiphoton tomography of patients with skin diseases
Authors: König Karsten , Speicher Marco , Bückle Rainer , Reckfort Julia , McKenzie Gordon , Welzel Julia , Koehler Martin J. , Elsner Peter , Kaatz Martin 
Published: July 2009

AbstractWe report on the first clinical study based on optical coherence tomography (OCT) in combination with multiphoton tomography (MPT) and dermoscopy. 47 patients with a variety of skin diseases and disorders such as skin cancer, psoriasis, hemangioma, connective tissue diseases, pigmented lesions, and autoimmune bullous skin diseases have been investigated with (i) state‐of‐the‐art OCT systems for dermatology including multibeam swept source OCT, (ii) the femtosecond laser multiphoton tomograph, and (iii) dermoscopes. Dermoscopy provides two‐dimensional color images of the skin surface. OCT images reflect modifications of the intratissue refractive index whereas MPT is based on nonlinear excitation of endogenous fluorophores and second harmonic generation. A stack of cross‐sectional OCT “wide field” images with a typical field of view of 5 × 2 mm2 gave fast information on the depth and the volume of the lesion. Multiphoton tomography provided 0.36 × 0.36 mm2 horizontal/diagonal optical sections within seconds of a particular region of interest with superior submicron resolution down to a tissue depth of 200 μm. The combination of OCT and MPT provides a unique powerful optical imaging modality for early detection of skin cancer and other skin diseases as well as for the evaluation of the efficiency of treatments. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Using electronic polarization from the internal continuum (EPIC) for intermolecular interactions
Authors: Truchon Jean‐François , Nicholl's Anthony , Grant J. Andrew , Iftimie Radu I. , Roux Benoît , Bayly Christopher I. 
Published: July 2009

AbstractRecently, the vacuum‐phase molecular polarizability tensor of various molecules has been accurately modeled (Truchon et al., J Chem Theory Comput 2008, 4, 1480) with an intramolecular continuum dielectric model. This preliminary study showed that electronic polarization can be accurately modeled when combined with appropriate dielectric constants and atomic radii. In this article, using the parameters developed to reproduce ab initio quantum mechanical (QM) molecular polarizability tensors, we extend the application of the “electronic polarization from internal continuu” (EPIC) approach to intermolecular interactions. We first derive a dielectric‐adapted least‐square‐fit procedure similar to RESP, called DRESP, to generate atomic partial charges based on a fit to a QM abinitio electrostatic potential (ESP). We also outline a procedure to adapt any existing charge model to EPIC. The ability of this to reproduce local polarization, as opposed to uniform polarization, is also examined leading to an induced ESP relative root mean square deviation of 1%, relative to ab initio, when averaged over 37 molecules including aromatics and alkanes. The advantage of using a continuum model as opposed to an atom‐centered polarizable potential is illustrated with a symmetrically perturbed atom and benzene. We apply EPIC to a cation‐π binding system formed by an atomic cation and benzene and show that the EPIC approach can accurately account for the induction energy. Finally, this article shows that the ab initio electrostatic component in the difficult case of the H‐bonded 4‐pyridone dimer, a highly polar and polarized interaction, is well reproduced without adjusting the vacuum‐phase parameters. © 2009 Wiley Periodicals, Inc. J Comput Chem 2010
Screening tests for the evaluation of nanoparticle titania photocatalysts
Authors: Thompson Kathryn , Goodall Josephine , Kellici Suela , Mattinson John A. , Egerton Terry A. , Rehman Ihtesham , Darr Jawwad A. 
Published: July 2009

AbstractBACKGROUND: Nano‐sized titanium dioxide has potential as a photocatalyst, and doped variants may have different photocatalytic properties. Nano‐titanias with a wide range of dopants and compositions can be prepared using continuous hydrothermal flow synthesis (CHFS), but when many samples are made, a large‐scale screening test is required to investigate their properties. A range of doped nano‐titanias were prepared using a CHFS route, and investigated as powders using a range of photocatalytic test methods. These tests included decolourization of methylene blue (in the presence of oxygen), partial oxidation of a simple alcohol (propan‐2‐ol) and the degradation of aqueous solutions of dichloroacetic acid. The practicality of the tests for large‐scale screening was considered, and the test results were cross‐correlated to see if any of them gave similar ranking for activity of the photocatalysts.RESULTS: Two of the tests, namely DCA degradation and propan‐2‐ol, gave similar rank ordering for the nanopowders, while the MB decolourization results did not suggest a strong correlation with any other test. The addition of metal dopants was observed to produce varying results between different dopants and tests.CONCLUSIONS: Two of the tests, DCA degradation and MB decolourization in visible light, were recommended for further use as screening tests. Copyright © 2009 Society of Chemical Industry
Effects of larval density on hematological stress indices in salamanders
Authors: Davis Andrew K. , Maerz John C. 
Published: July 2009

AbstractIn animals with complex life cycles, the quality of juvenile environments is important in shaping the longer‐term fitness of individuals. Larval density is a major factor governing quality of larval environments in amphibians, with high densities leading to reduced growth rates, smaller size at metamorphosis, and potentially long‐lasting postmetamorphic effects. A little‐studied effect of larval density is its impact on physiological stress of postmetamorphic individuals. We used a hematological approach, involving counts of specific white blood cells types (neutrophils and lymphocytes) that covary with corticosterone, to estimate stress levels in recently metamorphosed spotted salamanders (Ambystoma maculatum) that were reared in three different larval densities in outdoor mesocosms. In replicated treatments consisting of 12, 25, or 50 larvae, survival was, as expected, lowest and size at metamorphosis smallest in the highest density mesocosms. In addition, surviving salamanders from high‐density treatments had significantly higher neutrophil to lymphocyte ratios, indicative of high levels of stress hormones (corticosterone). This trend was not a result of density‐related differences in body condition as these did not vary with density. Further, estimated stress levels were similar regardless of whether the salamanders metamorphosed early or late, suggesting that the density effect on stress is long‐lasting even once realized density has been reduced through mortality or early metamorphosis. These results may be important in understanding amphibian population dynamics, since research on other vertebrate taxa demonstrates that high hematological stress indicators lead to reduced growth, survival, and increased disease susceptibility in vertebrate animals. J. Exp. Zool. 311A: 697–704, 2009. © 2009 Wiley‐Liss, Inc.
Rac‐ and R‐(+)‐[4,4′,5,5′‐2H4]‐2‐(1′‐[2′′,6′′‐dichlorophenoxy]‐ethyl)‐Δ2‐imidazoline (lofexidine)
Authors: Vartak Ashish P. , Sonar Vijayakumar , Crooks Peter A. 
Published: July 2009

AbstractThe synthesis of the d4‐forms of rac‐ and R‐lofexidine was accomplished. Two methods are described; one method is a two‐step synthesis of rac‐d4‐lofexidine from 2‐chloropropionitrile, the second method is a three‐step preparation of R‐d4‐lofexidine in absolute enantiomeric purity from S‐methyl lactate. The commercial availability of R‐methyl lactate makes this latter enantioselective synthesis applicable also to the synthesis of S‐d4‐ lofexidine. These procedures also conserve the utilization of the relatively expensive [1,1′,2,2′‐2H4]ethylene diamine precursor. The availability of S‐ and R‐d4‐lofexidines will enable pharmacokinetic studies to be carried out to determine if differential in vivo metabolism of the two enantiomers of lofexidine occurs. Copyright © 2009 John Wiley & Sons, Ltd.
Mass defect filter technique and its applications to drug metabolite identification by high‐resolution mass spectrometry
Authors: Zhang Haiying , Zhang Donglu , Ray Kenneth , Zhu Mingshe 
Published: July 2009

AbstractIdentification of drug metabolites by liquid chromatography/mass spectrometry (LC/MS) involves metabolite detection in biological matrixes and structural characterization based on product ion spectra. Traditionally, metabolite detection is accomplished primarily on the basis of predicted molecular masses or fragmentation patterns of metabolites using triple‐quadrupole and ion trap mass spectrometers. Recently, a novel mass defect filter (MDF) technique has been developed, which enables high‐resolution mass spectrometers to be utilized for detecting both predicted and unexpected drug metabolites based on narrow, well‐defined mass defect ranges for these metabolites. This is a new approach that is completely different from, but complementary to, traditional molecular mass‐ or MS/MS fragmentation‐based LC/MS approaches. This article reviews the mass defect patterns of various classes of drug metabolites and the basic principles of the MDF approach. Examples are given on the applications of the MDF technique to the detection of stable and chemically reactive metabolites in vitro and in vivo. Advantages, limitations, and future applications are also discussed on MDF and its combinations with other data mining techniques for the detection and identification of drug metabolites. Copyright © 2009 John Wiley & Sons, Ltd.
Inactivation of fibroblast growth factor receptor signaling in myelinating glial cells results in significant loss of adult spiral ganglion neurons accompanied by age‐related hearing impairment
Authors: Wang S.J. , Furusho M. , D'Sa C. , Kuwada S. , Conti L. , Morest D.K. , Bansal R. 
Published: July 2009

AbstractHearing loss has been attributed to many factors, including degeneration of sensory neurons in the auditory pathway and demyelination along the cochlear nerve. Fibroblast growth factors (FGFs), which signal through four receptors (Fgfrs), are produced by auditory neurons and play a key role in embryonic development of the cochlea and in neuroprotection against sound‐induced injury. However, the role of FGF signaling in the maintenance of normal auditory function in adult and aging mice remains to be elucidated. Furthermore, the contribution of glial cells, which myelinate the cochlear nerves, is poorly understood. To address these questions, we generated transgenic mice in which Fgfr1 and Fgfr2 were specifically inactivated in Schwann cells and oligodendrocytes but not in neurons. Adult mutant mice exhibited late onset of hearing impairment, which progressed markedly with age. The hearing impairment was accompanied by significant loss of myelinated spiral ganglion neurons. The pathology extended into the cochlear nucleus, without apparent loss of myelin or of the deletion‐bearing glial cells themselves. This suggests that perturbation of FGF receptor‐mediated glial function leads to the attenuation of glial support of neurons, leading to their loss and impairment of auditory functions. Thus, FGF/FGF receptor signaling provides a potentially novel mechanism of maintaining reciprocal interactions between neurons and glia in adult and aging animals. Dysfunction of glial cells and FGF receptor signaling may therefore be implicated in neurodegenerative hearing loss associated with normal aging. © 2009 Wiley‐Liss, Inc.