bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of imidazolium room temperature ionic liquids on the fluorescent properties of norfloxacin
Authors: Zou Yujie , Wang Huili , Wang Wenwei , Ma Meiping , Wang Ping , Wang Chengjun , Wang Xuedong
Published: December 2011

The effects of 12 imidazolium room temperature ionic liquids (RTILs), including [Cnmim]BF4, [Cnmim]PF6, and [Cnmim]Br (n = 4, 6, 8, 10), on the fluorescent properties of norfloxacin were examined. The fluorescence intensity of norfloxacin at 0.1 mg/L in methanol significantly increased with the addition of [Cnmim]BF4 and [Cnmim]PF6 into the solvent at 0.1–15.0%. The sensitizing effect may result from the higher viscosity of the RTILs–methanol mixture solvent than that of the methanol itself. However, the quenching effect on fluorescence of norfloxacin was observed in [Cnmim]Br–methanol solvent. The fluorescence intensities of norfloxacin decreased with an increase in the alkyl chain length of the alkyl substituents of the imidazolium ring of RTILs. The main interaction between the RTILs and norfloxacin is not by hydrogen bonding. The fact, that some RTILs can significantly sensitize fluorescence of norfloxacin, indicates that RTILs could be a group of promising solvents for development of sensitive spectrofluorimetric methods for determination of norfloxacin at ultra‐trace levels in environmental samples. Copyright © 2011 John Wiley & Sons, Ltd.
Systematic screening and characterization of the major bioactive components of Poria cocos and their metabolites in rats by LC‐ESI‐MSn
Authors: Ling Yun , Chen Mingcang , Wang Ke , Sun Zhaolin , Li Zhixiong , Wu Bin , Huang Chenggang
Published: December 2011

Poria cocos is a well‐known medicinal plant widely used in China and other East Asian countries owing to its various therapeutic effects. However, the bioactive constituents responsible for the pharmacological effects of Poria cocos and their metabolites in vivo are still unclear to date. The aim of the present study was to develop a practical method based on the combined use of the liquid chromatography coupled with electrospray ionization multistage tandem mass spectrometry (LC‐ESI‐MSn) for the comprehensive and systematic separation and characterization of the bioactive constituents of Poria cocos extract and their metabolites in rats. Based on the proposed strategy, a total of 34 compounds were characterized from the extract of Poria cocos. Among them, eight were unambiguously identified by comparing their retention times and mass spectra with those of reference standards, and 26 were tentatively identified on the basis of their MSn fragmentation behaviors and molecular weight information from literatures. In vivo, seven compounds were successfully detected in rat urine whereas one was found in rat plasma. This study proposed a series of potential bioactive components and provided helpful chemical information for further research on the action mechanism of traditional Chinese medicine. Copyright © 2011 John Wiley & Sons, Ltd.
Development and validation of a rapid LC‐MS/MS method for the determination of JCC76, a novel antitumor agent for breast cancer, in rat plasma and its application to a pharmacokinetics study
Authors: Cai Xiaohan , Zhong Bo , Su Bin , Xu Songlin , Guo Baochuan
Published: December 2011

JCC76 is a novel nimesulide analog that selectively inhibits the human epidermal growth factor receptor 2 (HER2) overexpressing breast cancer cell proliferation and tumor progression. To support further pharmacological and toxicological studies of JCC76, a novel and rapid method using liquid chromatography and electrospray ionization tandem mass spectrometry (LC‐ESI‐MS/MS) has been developed and validated for the quantification of the compound in rat plasma. A C18 column was used for chromatographic separation, and the mobile phase was aqueous ammonium formate (pH 3.7; 5 mm)–methanol (1:9, v/v) with an isocratic elution. With a simple liquid–liquid extraction procedure using the mixture of methyl tert‐butyl ether–hexane (1:2, v/v), the mean extraction efficiency of JCC76 in rat plasma was determined as 89.5–97.3% and no obvious matrix effect was observed. This method demonstrated a linear calibration range from 0.3 to 100 ng/mL for JCC76 in rat plasma and a small volume of sample consumption. The intra‐ and inter‐assay accuracy and precision were within ±10%. The pharmacokinetics of JCC76 was also profiled using this validated method in rats. In conclusion, this rapid and sensitive method has been proven to effectively quantify JCC76 for pharmacokinetics study. Copyright © 2011 John Wiley & Sons, Ltd.
Rhodium‐Catalyzed Asymmetric Hydrogenation of Olefins with PhthalaPhos, a New Class of Chiral Supramolecular Ligands
Authors: Pignataro Luca , Boghi Michele , Civera Monica , Carboni Stefano , Piarulli Umberto , Gennari Cesare
Published: December 2011

A library of 19 binol‐derived chiral monophosphites that contain a phthalic acid diamide group (PhthalaPhos) has been designed and synthesized in four steps. These new ligands were screened in the rhodium‐catalyzed enantioselective hydrogenation of prochiral dehydroamino esters and enamides. Several members of the library showed excellent enantioselectivity with methyl 2‐acetamido acrylate (6 ligands gave >97 % ee), methyl (Z)‐2‐acetamido cinnamate (6 ligands gave >94 % ee), and N‐(1‐phenylvinyl)acetamide (9 ligands gave >95 % ee), whilst only a few representatives afforded high enantioselectivities for challenging and industrially relevant substrates N‐(3,4‐dihydronaphthalen‐1‐yl)‐acetamide (96 % ee in one case) and methyl (E)‐2‐(acetamidomethyl)‐3‐phenylacrylate (99 % ee in one case). In most cases, the new ligands were more active and more stereoselective than their structurally related monodentate phosphites (which are devoid of functional groups that are capable of hydrogen‐bonding interactions). Control experiments and kinetic studies were carried out that allowed us to demonstrate that hydrogen‐bonding interactions involving the diamide group of the PhthalaPhos ligands strongly contribute to their outstanding catalytic properties. Computational studies carried out on a rhodium precatalyst and on a conceivable intermediate in the hydrogenation catalytic cycle shed some light on the role played by hydrogen bonding, which is likely to act in a substrate‐orientation effect.
An automated analysis of highly complex flow cytometry‐based proteomic data
Authors: Stuchlý Jan , Kanderová Veronika , Fišer Karel , Černá Daniela , Holm Anders , Wu Weiwei , Hrušák Ondřej , Lund‐Johansen Fridtjof , Kalina Tomáš
Published: December 2011

The combination of color‐coded microspheres as carriers and flow cytometry as a detection platform provides new opportunities for multiplexed measurement of biomolecules. Here, we developed a software tool capable of automated gating of color‐coded microspheres, automatic extraction of statistics from all subsets and validation, normalization, and cross‐sample analysis. The approach presented in this article enabled us to harness the power of high‐content cellular proteomics. In size exclusion chromatography‐resolved microsphere‐based affinity proteomics (Size‐MAP), antibody‐coupled microspheres are used to measure biotinylated proteins that have been separated by size exclusion chromatography. The captured proteins are labeled with streptavidin phycoerythrin and detected by multicolor flow cytometry. When the results from multiple size exclusion chromatography fractions are combined, binding is detected as discrete reactivity peaks (entities). The information obtained might be approximated to a multiplexed western blot. We used a microsphere set with >1,000 subsets, presenting an approach to extract biologically relevant information. The R‐project environment was used to sequentially recognize subsets in two‐dimensional space and gate them. The aim was to extract the median streptavidin phycoerythrin fluorescence intensity for all 1,000+ microsphere subsets from a series of 96 measured samples. The resulting text files were subjected to algorithms that identified entities across the 24 fractions. Thus, the original 24 data points for each antibody were compressed to 1–4 integrated values representing the areas of individual antibody reactivity peaks. Finally, we provide experimental data on cellular protein changes induced by treatment of leukemia cells with imatinib mesylate. The approach presented here exemplifies how large‐scale flow cytometry data analysis can be efficiently processed to employ flow cytometry as a high‐content proteomics method. © 2011 International Society for Advancement of Cytometry
Phenanthroline‐ and Terpyridine‐Substituted Tetralactam Macrocycles: A Facile Route to Rigid Di‐ and Trivalent Receptors and Interlocked Molecules
Authors: Dzyuba Egor V. , Baytekin Bilge , Sattler Dominik , Schalley Christoph A.
Published: December 2011

Bromo‐substituted Hunter/Vögtle‐type tetralactam macrocycles (TLMs) represent key intermediates for the attachment of terpyridyl and phenanthroline metal binding sites through cross‐coupling reactions. From these monovalent precursors, metal complexes can easily be obtained that present the macrocycles in a multivalent fashion. Depending on the nature of the metal ion, the properties of the complexes can be tuned with respect to valency (e.g., phen‐TLM + CuI: divalent, phen‐TLM + FeII: trivalent) and lability against TLM ligand exchange (e.g., CuI: slow, but reversible exchange, RuIICl2: kinetically inert).
Evaluation of the performance of a micro gas turbine cogeneration system in a sewage treatment facility: Optimized configuration of a cogeneration system
Authors: Basrawi Firdaus , Yamada Takanobu , Nakanishi Kimio
Published: December 2011

In this study, efficient configuration of a biogas‐fuelled cogeneration system (CGS) in a sewage treatment facility was investigated. The efficient configuration of the CGS was clarified on the basis of the relationship between exhaust heat recovery efficiency (ηehr) of the CGS and the ratio of yearly average heat demand to yearly average biogas production of the facility (Qh.d/Qb.p). The CGS was assumed to be used under Qh.d/Qb.p<ηehr,Qh.d/Qb.p≈ηehr, and Qh.d/Qb.p>ηehr conditions. It was found that although the CGS was able to cover total heat demand of the facility by only consuming biogas produced, from the point of view of energy utilization, reduction of unutilized biogas and reduction of electricity demand efficiencies, the most efficient CGS was obtained under the Qh.d/Qb.p≈ηehr condition. Under the Qh.d/Qb.p≈ηehr condition, energy utilization, reduction of unutilized biogas, and reduction of electrical demand efficiencies were 0.64, 0.99, and 0.32, respectively, whereas under the Qh.d/Qb.p<ηehr and Qh.d/Qb.p>ηehr conditions, energy utilization, reduction of unutilized biogas, and reduction of electrical demand efficiencies were in ranges of 0.56–0.64, 0.43–0.99, and 0.16–0.20, respectively. A more efficient system can be obtained if a CGS with lower ηehr such as a fuel cell is used under the Qh.d/Qb.p<ηehr condition and if a CGS with higher ηehr such as a steam turbine is used under the Qh.d/Qb.p>ηehr condition. © 2011 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.20389
Promyelocytic leukemia nuclear bodies support a late step in DNA double‐strand break repair by homologous recombination
Authors: Yeung Percy Luk , Denissova Natalia G. , Nasello Cara , Hakhverdyan Zhanna , Chen J. Don , Brenneman Mark A.
Published: December 2011

The PML protein and PML nuclear bodies (PML‐NB) are implicated in multiple cellular functions relevant to tumor suppression, including DNA damage response. In most cases of acute promyelocytic leukemia, the PML and retinoic acid receptor alpha (RARA) genes are translocated, resulting in expression of oncogenic PML‐RARα fusion proteins. PML‐NB fail to form normally, and promyelocytes remain in an undifferentiated, abnormally proliferative state. We examined the involvement of PML protein and PML‐NB in homologous recombinational repair (HRR) of chromosomal DNA double‐strand breaks. Transient overexpression of wild‐type PML protein isoforms produced hugely enlarged or aggregated PML‐NB and reduced HRR by ∼2‐fold, suggesting that HRR depends to some extent upon normal PML‐NB structure. Knockdown of PML by RNA interference sharply attenuated formation of PML‐NB and reduced HRR by up to 20‐fold. However, PML‐knockdown cells showed apparently normal induction of H2AX phosphorylation and RAD51 foci after DNA damage by ionizing radiation. These findings indicate that early steps in HRR, including recognition of DNA double‐strand breaks, initial processing of ends, and assembly of single‐stranded DNA/RAD51 nucleoprotein filaments, do not depend upon PML‐NB. The HRR deficit in PML‐depleted cells thus reflects inhibition of later steps in the repair pathway. Expression of PML‐RARα fusion proteins disrupted PML‐NB structure and reduced HRR by up to 10‐fold, raising the possibility that defective HRR and resulting genomic instability may figure in the pathogenesis, progression and relapse of acute promyelocytic leukemia. J. Cell. Biochem. 113: 1787–1799, 2012. © 2011 Wiley Periodicals, Inc.
Tolfenamic acid inhibits neuroblastoma cell proliferation and induces apoptosis: A novel therapeutic agent for neuroblastoma
Authors: Eslin Don , Sankpal Umesh T. , Lee Chris , Sutphin Robert M. , Maliakal Pius , Currier Erika , Sholler Giselle , Khan Moeez , Basha Riyaz
Published: December 2011

Current therapeutic options for recurrent neuroblastoma have poor outcomes that warrant the development of novel therapeutic strategies. Specificity protein (Sp) transcription factors regulate several genes involved in cell proliferation, survival, and angiogenesis. Sp1 regulates genes believed to be important determinants of the biological behavior of neuroblastoma. Tolfenamic acid (TA), a non‐steroidal anti‐inflammatory drug, is known to induce the degradation of Sp proteins and may serve as a novel anti‐cancer agent. The objective of this investigation was to examine the anti‐cancer activity of TA using established human neuroblastoma cell lines. We tested the anti‐proliferative effect of TA using SH‐SY5Y, CHLA90, LA1 55n, SHEP, Be2c, CMP 13Y, and SMS KCNR cell lines. Cells were treated with TA (0/25/50/100 µM) and cell viability was measured at 24, 48, and 72 h post‐treatment. Selected neuroblastoma cell lines were treated with 50 µM TA for 24 and 48 h and tested for cell apoptosis using Annexin‐V staining. Caspase activity was measured with caspase 3/7 Glo kit. Cell lysates were prepared and the expression of Sp1, survivin, and c‐PARP were evaluated through Western blot analysis. TA significantly inhibited the growth of neuroblastoma cells in a dose/time‐dependent manner and significantly decreased Sp1 and survivin expression. Apart from cell cycle (G0/G1) arrest, TA caused significant increase in the apoptotic cell population, caspase 3/7 activity, and c‐PARP expression. These results show that TA effectively inhibits neuroblastoma cell growth potentially through suppressing mitosis, Sp1, and survivin expression, and inducing apoptosis. These results show TA as a novel therapeutic agent for neuroblastoma. © 2011 Wiley Periodicals, Inc.
Polymorphisms in GSTM1 and XPD genes predict clinical outcome in advanced oral cancer patients treated with postoperative radiotherapy
Authors: Mahimkar Manoj B. , Samant Tanuja A. , Kannan Sadhana , Tulsulkar Jatin , Pai Prathamesh S. , Anantharaman Devasena
Published: December 2011

Polymorphisms in metabolic and DNA repair genes may alter protein function, consequently affecting patients' response to chemo/radiotherapy. We retrospectively assessed whether polymorphisms of glutathione‐S‐transferase genes GSTM1 (deletion), GSTT1 (deletion), GSTP1 (Ile105Val, rs1695), and DNA repair genes hOGG1 (Ser326Cys, rs1052133), XRCC1 (Arg194Trp, rs1799782, and Arg399Gln, rs25487), XPD (Asp312Asn, rs1799793, and Lys751Gln, rs13181) can predict clinical outcome in 187 oral squamous cell carcinoma patients treated with postoperative radiotherapy. The Cox proportional hazards model was used to evaluate the role of polymorphic genotypes on relapse‐free (RFS) and disease‐specific (DSS) survival. Deletion polymorphism of GSTM1 gene was significantly associated with DSS. The rs1799793 variant allele showed significant protection in both DSS and RFS. Significant increase in RFS but not in DSS was observed with polymorphic rs13181. The combined analysis of GSTM1 and XPD polymorphisms revealed favorable effect on survival. GSTM1 and XPD variant alleles, independently as well as in combination may serve as important predictors of clinical outcome in radiotherapy‐treated OSCC patients. © 2011 Wiley Periodicals, Inc.
Implementation and assessment of diffusion‐weighted partial Fourier readout‐segmented echo‐planar imaging
Authors: Frost Robert , Porter David A. , Miller Karla L. , Jezzard Peter
Published: December 2011

Single‐shot echo‐planar imaging has been used widely in diffusion magnetic resonance imaging due to the difficulties in correcting motion‐induced phase corruption in multishot data. Readout‐segmented EPI has addressed the multishot problem by introducing a two‐dimensional nonlinear navigator correction with online reacquisition of uncorrectable data to enable acquisition of high‐resolution diffusion data with reduced susceptibility artifact and T*2 blurring. The primary shortcoming of readout‐segmented EPI in its current form is its long acquisition time (longer than similar resolution single‐shot echo‐planar imaging protocols by approximately the number of readout segments), which limits the number of diffusion directions. By omitting readout segments at one side of k‐space and using partial Fourier reconstruction, readout‐segmented EPI imaging times could be reduced. In this study, the effects of homodyne and projection onto convex sets reconstructions on estimates of the fractional anisotropy, mean diffusivity, and diffusion orientation in fiber tracts and raw T2‐ and trace‐weighted signal are compared, along with signal‐to‐noise ratio results. It is found that projections onto convex sets reconstruction with 3/5 segments in a 2 mm isotropic diffusion tensor image acquisition and 9/13 segments in a 0.9 × 0.9 × 4.0 mm3 diffusion‐weighted image acquisition provide good fidelity relative to the full k‐space parameters. This allows application of readout‐segmented EPI to tractography studies, and clinical stroke and oncology protocols. Magn Reson Med, 2012. © 2011 Wiley‐Liss, Inc.
Denoising sparse images from GRAPPA using the nullspace method
Authors: Weller Daniel S. , Polimeni Jonathan R. , Grady Leo , Wald Lawrence L. , Adalsteinsson Elfar , Goyal Vivek K.
Published: December 2011

To accelerate magnetic resonance imaging using uniformly undersampled (nonrandom) parallel imaging beyond what is achievable with generalized autocalibrating partially parallel acquisitions (GRAPPA) alone, the DEnoising of Sparse Images from GRAPPA using the Nullspace method is developed. The trade‐off between denoising and smoothing the GRAPPA solution is studied for different levels of acceleration. Several brain images reconstructed from uniformly undersampled k‐space data using DEnoising of Sparse Images from GRAPPA using the Nullspace method are compared against reconstructions using existing methods in terms of difference images (a qualitative measure), peak‐signal‐to‐noise ratio, and noise amplification (g‐factors) as measured using the pseudo‐multiple replica method. Effects of smoothing, including contrast loss, are studied in synthetic phantom data. In the experiments presented, the contrast loss and spatial resolution are competitive with existing methods. Results for several brain images demonstrate significant improvements over GRAPPA at high acceleration factors in denoising performance with limited blurring or smoothing artifacts. In addition, the measured g‐factors suggest that DEnoising of Sparse Images from GRAPPA using the Nullspace method mitigates noise amplification better than both GRAPPA and L1 iterative self‐consistent parallel imaging reconstruction (the latter limited here by uniform undersampling). Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
Recommendations for mass spectrometry data quality metrics for open access data (corollary to the Amsterdam principles)
Authors: Kinsinger Christopher R. , Apffel James , Baker Mark , Bian Xiaopeng , Borchers Christoph H. , Bradshaw Ralph , Brusniak Mi‐Youn , Chan Daniel W. , Deutsch Eric W. , Domon Bruno , Gorman Jeff , Grimm Rudolf , Hancock William , Hermjakob Henning , Horn David , Hunter Christie , Kolar Patrik , Kraus Hans‐Joachim , Langen Hanno , Linding Rune , Moritz Robert L. , Omenn Gilbert S. , Orlando Ron , Pandey Akhilesh , Ping Peipei , Rahbar Amir , Rivers Robert , Seymour Sean L. , Simpson Richard J. , Slotta Douglas , Smith Richard D. , Stein Stephen E. , Tabb David L. , Tagle Danilo , Yates John R. , Rodriguez Henry
Published: December 2011

Policies supporting the rapid and open sharing of proteomic data are being implemented by the leading journals in the field. The proteomics community is taking steps to ensure that data are made publicly accessible and are of high quality, a challenging task that requires the development and deployment of methods for measuring and documenting data quality metrics. On September 18, 2010, the U.S. National Cancer Institute (NCI) convened the “International Workshop on Proteomic Data Quality Metrics” in Sydney, Australia, to identify and address issues facing the development and use of such methods for open access proteomics data. The stakeholders at the workshop enumerated the key principles underlying a framework for data quality assessment in mass spectrometry data that will meet the needs of the research community, journals, funding agencies, and data repositories. Attendees discussed and agreed up on two primary needs for the wide use of quality metrics: (i) an evolving list of comprehensive quality metrics and (ii) standards accompanied by software analytics. Attendees stressed the importance of increased education and training programs to promote reliable protocols in proteomics. This workshop report explores the historic precedents, key discussions, and necessary next steps to enhance the quality of open access data. By agreement, this article is published simultaneously in Proteomics, Proteomics Clinical Applications, Journal of Proteome Research, and Molecular and Cellular Proteomics, as a public service to the research community. The peer review process was a coordinated effort conducted by a panel of referees selected by the journals.
Effect of SiC/nano‐CeO2 on wear resistance and microstructures of Ti3Al/γ‐Ni matrix laser‐cladded composite coating on Ti–6Al–4V alloy
Authors: Li Jianing , Chen Chuanzhong , Hu Junhua
Published: December 2011

The Ti–6Al–4V alloy is an important aviation material, but has a poor resistance to slide wear. Laser cladding of the Al3Ti + Ni/Cr/C + TiB2/Al2O3 + SiC/nano‐CeO2 preplaced powders on the Ti–6Al–4V alloy can form the Ti3Al/γ‐Ni matrix composite coating, which improves the wear resistance of the substrate. In this study, the Al3Ti + Ni/Cr/C + TiB2/Al2O3 + SiC/nano‐CeO2 laser‐cladded coating was researched by means of X‐ray diffraction, scanning electron microscopy, and energy dispersive spectrometry. The experimental results indicate that under the action of SiC/nano‐CeO2, this composite coating exhibited a fine microstructure. Furthermore, the proper content of nano‐CeO2 decreased the crack tendency. The results above indicated that, it is feasible to improve the tribological property of the Al3Ti + Ni/Cr/C + TiB2/Al2O3 laser‐cladded coating by adding of SiC/nano‐CeO2. Copyright © 2011 John Wiley & Sons, Ltd.
Analysis the microscopic solid‐based wear process in the chemical mechanical planarization
Authors: Han Xuesong , Gan Yong X.
Published: December 2011

Chemical mechanical planarization (CMP), being the important technique of realizing the surface planarization, has already been widely applied in the microelectronic and computer industry. The abrasive size employed in the CMP, far less than that employed in the conventional grinding and material removal during CMP, is on the order of atoms or clusters of atoms and molecules. Classical continuum mechanics cannot give a reasonable explanation about the phenomenon in the CMP. Large‐scale classical molecular dynamics simulation of tribology interaction among nanoparticles and materials surface has been carried out to investigate the physical essence of surface planarization. The results show that simultaneous impact of several abrasive particles or the repeated impact of abrasive particles leads to material failure. For individual asperity contact in the CMP, non‐obvious Archard adhesive wear or abrasive wear is observed. The contact area is not entirely dependent upon the external pressure but also closely related to the relative position because of lateral motion between the particles and the substrate. The results also justify that no single wear mechanism dominates all operating conditions; different wear mechanisms operate with their relative importance changing as the sliding conditions change. As the slurry particles slide relative to the wafer surface, the atomic groups experience three stages, namely, interlock, elastic–plastic deformation and finally slip process; the surface planarization is mainly accomplished in the last two stages. Copyright © 2011 John Wiley & Sons, Ltd.
Probing Access Resistance of Solid‐State Nanopores with a Scanning‐Probe Microscope Tip
Authors: Hyun Changbae , Rollings Ryan , Li Jiali
Published: December 2011

An apparatus that integrates solid‐state nanopore ionic current measurement with a scanning‐probe microscope is developed. When a micrometer‐scale scanning‐probe tip is near a voltage‐biased nanometer‐scale pore (10–100 nm), the tip partially blocks the flow of ions to the pore and increases the pore access resistance. The apparatus records the current blockage caused by the probe tip and the location of the tip simultaneously. By measuring the current blockage map near a nanopore as a function of the tip position in 3D space in salt solution, the relative pore resistance increases due to the tip and ΔR/R0is estimated as a function of the tip location, nanopore geometry, and salt concentration. The amplitude of ΔR/R0also depends on the ratio of the pore length to its radius as Ohm's law predicts. When the tip is very close to the pore surface, ≈10 nm, experiments show that ΔR/R0depends on salt concentration as predicted by the Poisson and Nernst–Planck equations. Furthermore, the measurements show that ΔR/R0goes to zero when the tip is about five times the pore diameter away from the center of the pore entrance. The results in this work not only demonstrate a way to probe the access resistance of nanopores experimentally; they also provide a way to locate the nanopore in salt solution, and open the door to future nanopore experiments for detecting single biomolecules attached to a probe tip.
Adolescent female rats exhibiting activity‐based anorexia express elevated levels of GABAA receptor α4 and δ subunits at the plasma membrane of hippocampal CA1 spines
Authors: Aoki Chiye , Sabaliauskas Nicole , Chowdhury Tara , Min Jung‐Yun , Colacino Anna Rita , Laurino Kevin , Barbarich‐Marsteller Nicole C.
Published: December 2011

Activity‐based anorexia (ABA) is an animal model for anorexia nervosa that has revealed genetic links to anxiety traits and neurochemical characteristics within the hypothalamus. However, few studies have used this animal model to investigate the biological basis for vulnerability of pubertal and adolescent females to ABA, even though the great majority of the anorexia nervosa cases are females exhibiting the first symptoms during puberty. GABAergic inhibition of the hippocampus strongly regulates anxiety as well as plasticity throughout life. We recently showed that the hippocampal CA1 of female mice undergo a dramatic change at puberty onset—from expressing virtually none of the nonsynaptic α4βδ GABAA receptors (GABARs) prepubertally to expressing these GABARs at ∼7% of the CA1 dendritic spine membranes at puberty onset. Furthermore, we showed that this change underlies the enhanced modulation of anxiety, neuronal excitability, and NMDA receptor‐dependent synaptic plasticity in the hippocampus by the stress neurosteroid, THP (3α‐OH‐5α[β]‐pregnan‐20‐one or [allo]pregnanolone). Here, we used quantitative electron microscopy to determine whether ABA induction in female rats during adolescence also elevates the expression of α4 and δ subunits of α4βδ GABARs, as was observed at puberty onset for mice. Our analysis revealed that rats also exhibit a rise of α4 and δ subunits of α4βδ GABARs at puberty onset, in that these subunits are detectable at ∼6% of the dendritic spine membranes of CA1 pyramidal cells at puberty onset (postnatal day 32–36; P32–36) but this drops to about 2% by P40–P44. The levels of α4 and δ subunits at the CA1 spines remained low following exposure of females to either of the two environmental factors needed to generate ABA—food restriction and access to a running wheel for 4 days—from P40 to P44. This pattern contrasted greatly from those of ABA animals, for which the two environmental factors were combined. Within the hippocampus of ABA animals, 12% of the spine profiles were labeled for α4, reflecting a sixfold increase, relative to hippocampi of age‐matched (P44) control females (p < 0.005). Concurrently, 7% of the spine profiles were labeled for δ, reflecting a 130% increase from the control values of 3% (p = 0.01). No measurable change was detected for spine size. The observed magnitude of increase in the α4 and δ subunits at spines is sufficient to increase both tonic inhibition of hippocampus and anxiety during stress, thereby likely to exacerbate hyperactivity and weight loss. Synapse, 2012. © 2011 Wiley Periodicals, Inc.
Effect of transient blockade of N‐methyl‐D‐aspartate receptors at neonatal stage on stress‐induced lactate metabolism in the medial prefrontal cortex of adult rats: Role of 5‐HT1A receptor agonism
Authors: Uehara Takashi , Itoh Hiroko , Matsuoka Tadasu , Rujescu Dan , Genius Just , Seo Tomonori , Sumiyoshi Tomiki
Published: December 2011

Decreased activity of the medial prefrontal cortex (mPFC) has been considered a basis for core symptoms of schizophrenia, an illness associated with a neurodevelopmental origin. Evidence from preclinical and clinical studies indicates that serotonin (5‐HT)1A receptors play a crucial role in the energy metabolism of the mPFC. This study was undertaken to determine (1) if transient blockade of N‐methyl‐D‐aspartate receptors during the neonatal stage inhibit energy demands in response to stress, as measured by extracellular lactate concentrations, in the mPFC at the young adult stage, and (2) if tandospirone, a 5‐HT1A partial agonist, reverses the effect of the neonatal insult on energy metabolism. Male pups received MK‐801 (0.20 mg/kg) on postnatal days (PDs) 7–10. On PD 63, footshock stress‐induced lactate levels were measured using in vivo microdialysis technique. Tandospirone (0.1, 1.0, and 5.0 mg/kg) was administered once daily for 14 days before the measurement of lactate levels. Neonatal MK‐801 treatment suppressed footshock stress‐induced lactate production in the mPFC, but not caudate‐putamen, whereas basal lactate levels were not significantly changed in either brain region. The MK‐801‐induced suppression of footshock stress‐induced lactate production in the mPFC was attenuated by tandospirone at 1.0mg/kg/day, but not 0.1 or 5.0 mg/kg/day, which is an effect antagonized by coadministration of WAY‐100635, a selective 5‐HT1A antagonist. These results suggest a role for impaired lactate metabolism in some of the core symptoms of schizophrenia, for example, negative symptoms and cognitive deficits. The implications for the ability of 5‐HT1A agonism to ameliorate impaired lactate production in the mPFC of this animal model are discussed. Synapse, 2012. © 2011 Wiley Periodicals, Inc.
Impact of Clinical and Pathohistological Characteristics on the Incidence of Recurrence and Survival in Elderly Patients with Gastric Cancer
Authors: Dittmar Yves , Rauchfuss Falk , Götz Max , Scheuerlein Hubert , Jandt Karin , Settmacher Utz
Published: December 2011

Background

Gastric cancer is one of the most frequent malignant tumors worldwide. Despite improvements in diagnostic procedures, as well as the introduction of multimodal treatment strategies, the overall prognosis remains poor. The role of gastric resection in elderly patients with gastric cancer has not been clearly defined as yet. The goal of the present study was to assess whether specific pathohistological features result in different outcomes for younger patients and elderly patients.

Methods

A total of 272 patients with advanced gastric cancer treated surgically in our hospital between 1998 and 2009 were included in the study. Data were analyzed from a prospectively maintained database.

Results

Median overall survival was 84 months in the younger subgroup and 37 months in the elderly subgroup (P = 0.038), whereas local recurrence occurred more frequently in younger patients (33% vs. 23%). We identified positive lymph nodes at the contralateral curvature, perilymphonodular tumor cells, and positive lymph node conglomerates as strong negative prognostic factors. There were few pathohistological characteristics that affected survival and the incidence of tumor recurrence differently in elderly and younger patients. Although only a few elderly patients underwent chemotherapy plus gastric resection (7% vs. 28% of the younger patients), there was a trend toward longer survival for those who received multimodal treatment.

Conclusions

Our results suggest that there is no tumor‐related prognostic difference between young and elderly patients that would preclude radical surgery in elderly patients, as long as they are generally fit for surgery.
Personality and Skin Conductance Responses to Reward and Punishment
Authors: Mardaga Solange , Hansenne Michel
Published: December 2011

For several years now, the somatic aspect of emotions has been regarded as a major factor in the decision-making process. A large body of literature has investigated this issue, within the somatic marker hypothesis perspective, using the classical Iowa Gambling Task (IGT). Many studies reported an influence of clinical and differential factors, including personality, on IGT performance. On the other hand, personality appears to modulate the emotional responses as a function of valence (i.e., responses to rewards vs. punishments). The present study investigated whether the influence of personality on the decision-making process might be mediated by differential emotional responsiveness. Skin conductance levels were recorded in 32 subjects while performing the IGT. The results showed that novelty seeking (NS) modulated the skin conductance responses to feedback, and both NS and harm avoidance (HA) influenced anticipative response development. We also found that NS tended to modulate the final score, beyond the influence of beneficial anticipative autonomic responses. The present data partially support the hypothesis that personality-related differential emotional responsiveness may modulate somatic marker development in a decision-making situation. On the other hand, personality influence on the performance was not entirely explained by these emotional differences.
Sex Differences in Time Production Revisited
Authors: Glicksohn Joseph , Hadad Yamit
Published: December 2011

Individual differences in time production should indicate differences in the rate of functioning of an internal clock, assuming the existence of such a clock. And sex differences in time production should reflect a difference in the rate of functioning of that clock between men and women. One way of approaching the data is to compute individual regressions of produced duration (P) on target duration (T), after log transformation, and to derive estimates for the intercept and the slope. One could investigate a sex difference by comparing these estimates for men and women; one could also contrast them by looking at mean log(P). Using such indices, we found a sex difference in time production, female participants having a relatively faster internal clock, making shorter time productions, and having a smaller exponent. The question is whether a sex difference in time production would be found using other methods for analyzing the data: (1) the P/T ratio; (2) an absolute discrepancy (|P-T|) score; and (3) an absolute error (|P-T|/T) score. For the P/T ratio, female participants have a lower mean ratio in comparison to the male participants. In contrast, the |P-T| and |P-T|/T indices seem to be seriously compromised by wide individual differences.
Tropical cyclones and the ecohydrology of Australia's recent continental‐scale drought
Authors: McGrath Gavan S. , Sadler Rohan , Fleming Kevin , Tregoning Paul , Hinz Christoph , Veneklaas Erik J.
Published: December 2011

The Big Dry, a recent drought over southeast Australia, began around 1997 and continued until 2011. We show that between 2002–2010, instead of a localized drought, there was a continent‐wide reduction in water storage, vegetation and rainfall, spanning the northwest to the southeast of Australia. Trends in water storage and vegetation were assessed using Gravity Recovery and Climate Experiment (GRACE) and Normalized Difference Vegetation Index (NDVI) data. Water storage and NDVI are shown to be significantly correlated across the continent and the greatest losses of water storage occurred over northwest Australia. The frequency of tropical cyclones over northwest Australia peaked just prior to the launch of the GRACE mission in 2002. Indeed, since 1981, decade‐scale fluctuations in tropical cyclone numbers coincide with similar variation in rainfall and vegetation over northwest Australia. Rainfall and vegetation in southeast Australia trended oppositely to the northwest prior to 2001. Despite differences between the northwest and southeast droughts, there is reason to believe that continental droughts may occur when the respective climate drivers align.
Mineral, Virginia, earthquake illustrates seismicity of a passive‐aggressive margin
Authors: Wolin Emily , Stein Seth , Pazzaglia Frank , Meltzer Anne , Kafka Alan , Berti Claudio
Published: December 2011

The August 2011 M 5.8 Mineral, Virginia, earthquake that shook much of the northeastern U.S. dramatically demonstrated that passive continental margins sometimes have large earthquakes. We illustrate some general aspects of such earthquakes and outline some of the many unresolved questions about them. They occur both offshore and onshore, reaching magnitude 7, and are thought to reflect reactivation of favorably‐oriented, generally margin‐parallel, faults created during one or more Wilson cycles by the modern stress field. They pose both tsunami and shaking hazards. However, their specific geologic setting and causes are unclear because large magnitude events occur infrequently, microseismicity is not well recorded, and there is little, if any, surface expression of repeated ruptures. Thus presently active seismic zones may be areas associated with higher seismicity over the long term, the present loci of activity that migrates, or aftershock zones of large prehistoric earthquakes. The stresses causing the earthquakes may result from platewide driving forces, glacial isostatic adjustment, localized margin stresses, and/or dynamic topography. The resulting uncertainties make developing cost‐effective mitigation strategies a major challenge. Progress on these issues requires integrating seismic, geodetic, and geological techniques.
Quasi real‐time fault model estimation for near‐field tsunami forecasting based on RTK‐GPS analysis: Application to the 2011 Tohoku‐Oki earthquake (Mw 9.0)
Authors: Ohta Yusaku , Kobayashi Tatsuya , Tsushima Hiroaki , Miura Satoshi , Hino Ryota , Takasu Tomoji , Fujimoto Hiromi , Iinuma Takeshi , Tachibana Kenji , Demachi Tomotsugu , Sato Toshiya , Ohzono Mako , Umino Norihito
Published: December 2011

Real‐time crustal deformation monitoring is extremely important for achieving rapid understanding of actual earthquake scales, because the measured permanent displacement directly gives the true earthquake size (seismic moment, Mw) information, which in turn, provides tsunami forecasting. We have developed an algorithm to detect/estimate static ground displacements due to earthquake faulting from real‐time kinematic GPS (RTK‐GPS) time series. The new algorithm identifies permanent displacements by monitoring the difference of a short‐term average (STA) to a long‐term average (LTA) of the GPS time series. We assessed the noise property and precision of the RTK‐GPS time series with various baseline length conditions and orbits and discerned that the real‐time ephemerides based on the International GNSS Service (IGS) are sufficient for crustal deformation monitoring with long baselines up to ∼1,000 km. We applied the algorithm to data obtained in the 2011 off the Pacific coast of Tohoku earthquake (Mw 9.0) to test the possibility of coseismic displacement detections, and further, we inverted the obtained displacement fields for a fault model; the inversion estimated a fault model with Mw 8.7, which is close to the actual Mw of 9.0, within five minutes from the origin time. Once the fault model is estimated, tsunami waveforms can be immediately synthesized using pre‐computed tsunami Green's functions. The calculated waveforms showed good agreement with the actual tsunami observations both in arrival times and wave heights, suggesting that the RTK‐GPS data by our algorithm can provide reliable rapid tsunami forecasting that can complement existing tsunami forecasting systems based on seismic observations.
Theoretical characterization of intermolecular vibrational states through the multi-configuration time dependent Hartree approach: The He2,3ICl clusters
Authors: Valdés Álvaro , Prosmiti Rita , Villarreal Pablo , Delgado-Barrio Gerardo
Published: December 2011

Benchmark, full-dimensional calculations on the ground and excited vibrational states for the tetra-, and penta-atomic weakly bound He2,3ICl complexes are reported. The representation of the potential energy surfaces includes three-body HeICl potentials parameterized to coupled-cluster singles, doubles, and perturbative triples ab initio data. These terms are important in accurately describing the interactions of such highly floppy systems. The corresponding 6D/9D computations are performed with the multi-configuration time dependent Hartree method, using natural potential fits, and a mode combination scheme to optimize the computational effort in the improved relaxation calculations. For these complexes several low-lying vibrational states are computed, and their binding energies and radial/angular probability density distributions are obtained. We found various isomers which are assigned to different structural models related with combinations of the triatomic isomers, like linear, T-shaped, and antilinear ones. Comparison of these results with recent experimental data is presented, and the quantitative deviations found with respect to the experiment are discussed.
Sound wave propagation in armchair single walled carbon nanotubes under thermal environment
Authors: Naceri Mokhtar , Zidour Mohamed , Semmah Abdelwahed , Houari Mohammed Sid Ahmed , Benzair Abdelnour , Tounsi Abdelouahed
Published: December 2011

This paper develops a model that analyzes the wave propagation in armchair single-walled carbon nanotubes (SWCNTs) under thermal environment. The effect of a small length scale is incorporated in the formulations using nonlocal Levinson beam model. Unlike Timoshenko beam theory, Levinson beam theory satisfies zero traction boundary conditions on the upper and lower surface of the structures, so there is no need to use a shear correction factor. The equivalent Young’s modulus and shear modulus for armchair SWCNT are derived using an energy-equivalent model. Results indicate significant dependence of natural frequencies on the temperature change as well as the chirality of armchair carbon nanotube. These findings are important in mechanical design considerations of devices that use carbon nanotubes.
Effect of temperature and strain on the optical polarization of (In)(Al)GaN ultraviolet light emitting diodes
Authors: Kolbe Tim , Knauer Arne , Chua Chris , Yang Zhihong , Kueller Viola , Einfeldt Sven , Vogt Patrick , Johnson Noble M. , Weyers Markus , Kneissl Michael
Published: December 2011

The temperature and strain dependence of the polarization of the in-plane electroluminescence of (0001) orientated (In)(Al)GaN multiple quantum well light emitting diodes in the ultraviolet spectral range has been investigated. For light emitting diodes with emission wavelength shorter than 300 nm the transversal-electric polarized emission intensity increases relative to the transversal-magnetic emission with increasing temperature, whereas it decreases for ultraviolet light emitting diodes with longer emission wavelength. This effect can be attributed to occupation of deeper valence bands with increasing temperature. In addition, strain also strongly influence the in-plane light polarization of near ultraviolet light emitting diodes. The transversal-magnetic polarized emission becomes more dominant with decreasing in-plane tensile strain of the InGaN/(In)(Al)GaN multiple quantum well active region.
Origin of charge separation in III-nitride nanowires under strain
Authors: Wu Yelong , Chen Guangde , Wei Su-Huai , Al-Jassim Mowafak M. , Yan Yanfa
Published: December 2011

The structural and electronic properties of BN, AlN, and GaN nanowires (NWs) under different strain condition are investigated using first-principles calculations. We found an anomaly of band gap change with respect to the applied external uniaxial strain. We show that this is due to the band crossing caused by the crystal field splitting at the top of the valance band. Due to the difference of the atomic relaxation at the core and surface regions of the NW, we show that electron and hole separation can be achieved when the compressive uniaxial strain exceeds the critical value |εc|.
UV - visible spectroscopic properties of dissolved fulvic acids extracted from salined fluvo-aquic soils in the Hetao Irrigation District, China
Authors: Jiang Jinyuan , Yu Huibin , Xi Beidou , Meng Fansheng , Zhou Yuexi , Liu Hongliang
Published: December 2011

The elemental composition and the UV–visible spectroscopic properties of dissolved fulvic acids (FA) extracted from salined fluvo-aquic soils in the Hetao Irrigation District were examined to evaluate the humification degree of FA and salinisation processes of soils. Composite soil samples of different depths (0–20, 20–40, 40–60, 60–80 cm) were collected from four native halophyte soils [communities Salicornia europaea (CSE), Suaeda glauca (CSG), Kalidium foliatum (CKF), Sophora alopecuroides (CSA)] and two furrow-irrigated fields [corn (CFD), wheat (WFD)] along a saline impact gradient. Seven humification indices (HIXs: C/N, SUVA, E2/E3, E2/E4, S275–295, S350–400, and S250–400), deduced from elemental analysis and UV–visible spectroscopy of FAs, were used to evaluate the humification degree. The humification degree of FA from the WFD soil was the highest, followed by CFD, CSA, CKF, CSG, and CSE. There were significant relationships between the seven HIXs (P < 0.05). The exchangeable sodium percentage (ESP) exhibited close correlations with the seven HIXs, and the humification degree increased with decreasing ESP. The HIX can not only indicate the humification degree of soil organic matter but also characterise the salinisation processes of soils.