bluuebunny/crossref_metadata_2025 huggingface dataset:
MicroRNA–194 Is A Target of Transcription Factor 1 (Tcf1, HNF1α) in Adult Liver and Controls Expression of Frizzled–6
Authors: Krützfeldt Jan , Rösch Nora , Hausser Jean , Manoharan Muthiah , Zavolan Mihaela , Stoffel Markus
Published: September 2011

Transcription factor 1 (Tcf1; hepatocyte nuclear factor 1α [HNF1α]) is critical for hepatocyte development and function. Whether Tcf1 also regulates hepatic microRNAs (miRNAs) has not been investigated yet. Here we analyzed Tcf1–dependent miRNA expression in adult mice in which this transcription factor had been genetically deleted (

Tcf1

−/−) using miRNA microarray analysis. The miR–192/–194 cluster was markedly down–regulated in liver of

Tcf1

−/− mice. MiR–192/–194 levels were also decreased in two other tissues that express Tcf1, kidney and small intestine, although to a lesser extent than in liver. In order to identify targets of miR–192/–194

in vivo

we combined Affymetrix gene analysis of liver in which miR–192/–194 had been silenced or overexpressed, respectively, and tested regulated messenger RNAs (mRNAs) with multiple binding sites for these miRNAs. This approach revealed frizzled–6 (Fzd6) as a robust endogenous target of miR–194. MiR–194 also targets human FZD6 and expression of miR–194 and Fzd6 are inversely correlated in a mouse model of hepatocellular carcinoma (Dgcr8flox/flox p53flox/flox × Alb–Cre).

Conclusion

: Our results support a role of miR–194 in liver tumorigenesis through its endogenous target Fzd6. These results may have important implications for Tcf1–mediated liver proliferation. (Hepatology 2012;55:98–107)
Evaluation of a probabilistic approach to simulation of alkalinity and electrical conductivity at a river bank filtration site
Authors: Thakur A. K. , Singh V. P. , Ojha C. S. P.
Published: September 2011

In river bank filtration, impurities present in the river water travel with the bank filtrate towards the pumping well. During this passage, certain types of impurities, such as turbidity, total coliform, and so forth, may get attenuated; however, it is interesting to note that some of the instant raw river water quality parameters, such as alkalinity and electrical conductivity, increase after the passage of water through the porous medium. This occurs because water, when passing through the soil pores, absorbs many of the solutes that cause an increase in alkalinity and electrical conductivity. Measurements at a river bank filtration site for a year showed that alkalinity of 116–32 mg l−1 in river water increased to 222.4–159.9 mg l−1 in the river bank filtered water. Likewise, the electrical conductivity increased from 280–131 μS cm−1 to 462–409.6 μS cm−1. This study uses a probabilistic approach for investigating the variation of alkalinity and electrical conductivity of source water that varies with the natural logarithm of the concentration of influent water. The probabilistic approach has the potential of being used in simulating the variation of alkalinity and electrical conductivity in river bank filtrate. Copyright © 2011 John Wiley & Sons, Ltd.
Groundwater–surface water interactions in a lowland watershed: source contribution to stream flow
Authors: Guinn Garrett C. , Vulava Vijay M. , Callahan Timothy J. , Jones Martin L.
Published: September 2011

The lower coastal plain of the Southeast USA is undergoing rapid urbanisation as a result of population growth. Land use change has been shown to affect watershed hydrology by altering stream flow and, ultimately, impairing water quality and ecologic health. However, because few long‐term studies have focused on groundwater–surface water interactions in lowland watersheds, it is difficult to establish what the effect of development might be in the coastal plain region. The objective of this study was to use an innovative improvement to end‐member mixing analysis (EMMA) to identify time sequences of hydrologic processes affecting storm flow. Hydrologic and major ion chemical data from groundwater, soil water, precipitation and stream sites were collected over a 2‐year period at a watershed located in USDA Forest Service's Santee Experimental Forest near Charleston, South Carolina, USA. Stream flow was ephemeral and highly dependent on evapotranspiration rates and rainfall amount and intensity. Hydrograph separation for a series of storm events using EMMA allowed us to identify precipitation, riparian groundwater and streambed groundwater as main sources to stream flow, although source contribution varied as a function of antecedent soil moisture condition. Precipitation, as runoff, dominated stream flow during all storm events while riparian and streambed groundwater contributions varied and were mainly dependent on antecedent soil moisture condition. Sensitivity analyses examined the influence of 10% and 50% increases in analyte concentration on EMMA calculations and found that contribution estimates were very sensitive to changes in chemistry. This study has implications on the type of methodology used in traditional forms of EMMA research, particularly in the recognition and use of median end‐member water chemistry in hydrograph separation techniques. Potential effects of urban development on important hydrologic processes (groundwater recharge, interflow, runoff, etc.) that influence stream flow in these lowland watersheds were qualitatively examined. Copyright © 2011 John Wiley & Sons, Ltd.
Investigation of karstic hydrological processes of Niangziguan Springs (North China) using wavelet analysis
Authors: Hao Yonghong , Liu Guoliang , Li Huamin , Li Zhongtang , Zhao Jiaojuan , J. Yeh Tian‐Chyi
Published: September 2011

Niangziguan Spring complex is the largest karst spring in North China. We investigate the karst hydrological processes by using Morlet wavelet transform analysis and cross wavelet analysis based on monthly precipitation from 1958 to 2010 and spring discharge from 1958 to 2009. From Morlet wavelet transform coefficients of precipitation and the spring discharge in Niangziguan Springs Basin, we find that the precipitation and discharge are characterized by the multi‐scale features in the time domain, and the energy distribution of the signal is highly irregular across scales. Although precipitation eventually becomes spring discharge by infiltrating and propagating through karst formations, the signals are attenuated. The results also show that the precipitation of Niangziguan Springs Basin has the main periodic components of 1‐, 5‐, 12‐, and 17‐year periods with alternating wet–drought cycle. Similarly, the spring discharge of Niangziguan Springs has the main components of 17‐year periods, but the 1‐, 5‐, and 12‐year periodicity of precipitation are not reflected in spring discharge, which is filtered by the aquifers. The results of cross wavelet analysis reveal that the precipitation and spring discharge share the common periodicity of 17 years. This means that those signals with high energy and long timescales can penetrate through the aquifer and be reflected in spring discharge, whereas other signals are filtered and modified. Copyright © 2011 John Wiley & Sons, Ltd.
Raindrop‐induced saltation and the enrichment of sediment discharged from sheet and interrill erosion areas
Authors: Kinnell P. I. A.
Published: September 2011

Sheet and interrill erosion areas are sources of soil material rich in nutrients and pollutants. The loss of soil, nutrients and other chemicals from these areas is a matter of concern both in terms of maintaining soil productivity and the health of offsite environments. Many experiments on rainfall erosion have shown enrichment of fine material, nutrients and other chemicals in the sediment discharged for sheet and interrill erosion areas, but often these results were obtained over short periods of time. A qualitative mechanistic model of raindrop‐induced saltation is used to illustrate how this transport mechanism influences the composition of sediment discharged by rain‐impacted flow. Initially, fast moving particles are enriched in the sediment discharge but, over time, during a rainfall event, slower moving particles become more represented. Raindrop‐induced saltation promotes the storage of material on the soil surface with a coarser composition than the original soil. Winnowing of material from this storage by the development of flow‐driven saltation during high‐intensity events can modify the composition of the sediment discharged later by raindrop‐induced saltation. Given stable soil particles, the composition of the sediment discharged at the steady state is the same as the original soil. Enrichment is a non‐steady‐state phenomenon and failure to recognize the transient nature of enrichment may lead to inappropriate interpretation of the implications of the results from short‐term experiments. Copyright © 2011 John Wiley & Sons, Ltd.
Effects of spatial aggregation of soil spatial information on watershed hydrological modelling
Authors: Li Runkui , Zhu A‐Xing , Song Xianfeng , Li Baolin , Pei Tao , Qin Chengzhi
Published: September 2011

Many researchers have examined the impact of detailed soil spatial information on hydrological modelling due to the fact that such information serves as important input to hydrological modelling, yet is difficult and expensive to obtain. Most research has focused on the effects at single scales; however, the effects in the context of spatial aggregation across different scales are largely missing. This paper examines such effects by comparing the simulated runoffs across scales from watershed models based on two different levels of soil spatial information: the 10‐m‐resolution soil data derived from the Soil‐Land Inference Model (SoLIM) and the 1:24000 scale Soil Survey Geographic (SSURGO) database in the United States. The study was conducted at three different spatial scales: two at different watershed size levels (referred to as full watershed and sub‐basin, respectively) and one at the model minimum simulation unit level. A fully distributed hydrologic model (WetSpa) and a semi‐distributed model (SWAT) were used to assess the effects. The results show that at the minimum simulation unit level the differences in simulated runoff are large, but the differences gradually decrease as the spatial scale of the simulation units increases. For sub‐basins larger than 10 km2 in the study area, stream flows simulated by spatially detailed SoLIM soil data do not significantly vary from those by SSURGO. The effects of spatial scale are shown to correlate with aggregation effect of the watershed routing process. The unique findings of this paper provide an important and unified perspective on the different views reported in the literature concerning how spatial detail of soil data affects watershed modelling. Different views result from different scales at which those studies were conducted. In addition, the findings offer a potentially useful basis for selecting details of soil spatial information appropriate for watershed modelling at a given scale. Copyright © 2011 John Wiley & Sons, Ltd.
Cost‐effectiveness of KRAS testing in metastatic colorectal cancer patients in the United States and Germany
Authors: Vijayaraghavan Arthi , Efrusy Molly B. , Göke Burkhard , Kirchner Thomas , Santas Christopher C. , Goldberg Richard M.
Published: September 2011

The objective of this study was to determine the cost‐effectiveness of testing for KRAS mutations before administering EGFR inhibitors such as cetuximab and panitumumab for patients with advanced metastatic colorectal cancer (mCRC) in the United States and Germany. We developed a lifetime Markov model of costs and survival associated with treating mCRC patients to assess the impact of KRAS testing before administering EGFR inhibitor‐containing chemotherapy regimens. Overall, combination therapies involving cetuximab plus irinotecan/FOLFIRI had a better life expectancy (25.83 weeks) than cetuximab or panitumumab alone. Use of KRAS testing (assuming KRAS mutant patients receive only irinotecan) was equally effective and saved $12,428 per patient in the United States. When KRAS mutant patients received best supportive care, the life expectancy decreased slightly (24.26 weeksvs. 25.83 weeks) and the costs decreased by $13,501 in the United States and €9,560 in Germany. For patients treated with cetuximab alone, use of KRAS testing to identify mutations lowered costs by $8,040 per patient in the U.S. analysis and €3,856 per patient in the German analysis. For patients treated with panitumumab alone, use of KRAS testing to identify mutations lowered costs by $7,546 per patient in the U.S. analysis and €4,612 per patient in the German analysis. Model results were sensitive to the cost of chemotherapy regimens and the prevalence of KRAS mutations in the population. Under most scenarios, using KRAS testing to select patients for EGFR inhibitor therapy saved $7,500–$12,400 per patient in the United States and €3,900–€9,600 per patient in Germany with equivalent clinical outcomes.
δ‐Mercaptolysine Assisted Ubiquitination
Authors: Kumar K. S. Ajish , Brik Ashraf
Published: September 2011

The field of chemical biology of ubiquitin is gaining significant interest in recent years due to the diversity and complexity of the ubiquitin signal in numerous biological functions in eukaryotes. The inability of biological methods to prepare ubiquitinated peptides and proteins with full control over the ubiquitination sites, types, and lengths of the ubiquitin chains is one of the main challenges in the ongoing efforts to fully understand the ubiquitin signal at the molecular level. This has been a major driving force for the development of chemical tools to complement biological methods in preparing ubiquitin bioconjugates for various biochemical and structural studies. This review deals with the recent advances in developing chemical methods for the synthesis of ubiquitinated peptides and proteins assisted by δ‐mercaptolysine, which enable isopeptide formation in a highly efficient and chemoselective manner.
Light‐guided lumpectomy: first clinical experience
Authors: Dayton Amanda , Soot Laurel , Wolf Ronald , Gougoutas‐Fox Christina , Prahl Scott
Published: September 2011

Despite numerous advances, lumpectomy remains a challenging procedure. We report on the early use of light‐guided lumpectomy. Eight patients with non‐palpable breast cancer undergoing lumpectomy for biopsy‐proven and radiographically identifiable cancer were enrolled in the study. An optical wire was designed that incorporated a standard hook‐wire with an optical fiber. The optical wire was placed in the same manner as a standard hook‐wire. During light‐guided lumpectomy, an eye‐safe laser illuminated the optical wire and created a sphere of light surrounding the cancer. The light was visible at the beginning of each surgery and facilitated approaching the cancer without using the wire. Dissection around the sphere of light kept the wire tip within the surgical specimen. Three of eight initial surgical specimens had focally positive margins. Additional cavity shaves were performed during five lumpectomies and resulted in negative margins in seven of eight patients. Light‐guided lumpectomy is a minor change to breast conserving surgery that can be easily incorporated into clinical practice. Further investigation into the clinical benefit of light‐guided lumpectomy is warranted. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Assessment of decellularized porcine diaphragm conjugated with gold nanomaterials as a tissue scaffold for wound healing
Authors: Cozad Matthew J. , Bachman Sharon L. , Grant Sheila A.
Published: September 2011

One million Americans suffer from chronic wounds every year with diabetics and older populations representing the majority. Mechanisms that may be responsible for the reduced healing response in these patients include reduction in growth factors or vascularization and an increase in free radical levels. The focus of this study was to develop a biocompatible gold/porcine diaphragm scaffold capable of sustaining fibroblast attachment and proliferation which was measured using viability and dsDNA assays. The free radical scavenging properties, as measured by ROS assays, were also investigated as a mechanism for improving the wound environment. Results indicated 69–89% viability for gold nanoparticle (AuNP) scaffolds and 51–74% for gold nanorod (AuNR) scaffolds as compared to 100% for decellularized scaffolds and 77% for crosslinked scaffolds. All scaffolds exhibited good cell attachment while AuNP‐1X scaffolds showed the greatest cell proliferation with a 74% increase in dsDNA content from Day 3 to 7. AuNP‐2X and AuNP‐4X scaffolds generated higher levels of free radicals with AuNP‐4X generating over twice as much as decellularized scaffolds. This study suggests the capability for gold/porcine diaphragm scaffolds to enhance cell proliferation while the modification of free radical generation appears to be dependent on nanomaterial shape and concentration. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.
Effects of dialdehyde starch on calcification of collagen matrix
Authors: Liu Yi , Acharya Gayathri , Lee Chi H.
Published: September 2011

Dialdehyde starch (DAS), a polymeric aldehyde derived from naturally occurring polysaccharide, was used as an additive to the collagen (COL) matrix in an effort to improve its physical and biological properties. The effects of DAS on the thermal stability of COL were characterized by differential scanning calorimetry. The conformational changes in COL were characterized by resistance to protease degradation assay, residual amine analysis, and Fourier‐transform infrared spectroscopy. To assess biocompatibility enhancement, the calcium content in porcine aortic valve interstitial cells (PAVICs) on exposure to cardiovascular stents coated with DAS‐stabilized COL was examined using atomic absorption spectroscopy. Thermal stability of DAS‐stabilized COL was affected by DAS in a concentration dependent manner, reaching maximum at the saturation concentration (DAS:COL = 1:120) and decreasing the thermal stability at the concentrations above saturation. In the long‐term exposure condition (21 days), stents coated with DAS at the lowest concentration significantly reduced the calcification rate of PAVIC, when compared with bare stent (p= 0.001). DAS appears to be an efficient additive to the COL matrix in improving its physical and biological properties. Further optimization process is needed for the suitable crosslinking conditions of DAS, which subsequently enhances thermal strength and anticalcification activities of COL matrix. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.
Breastfeeding protects against hip fracture in postmenopausal women: The Tromsø study
Authors: Bjørnerem Åshild , Ahmed Luai A , Jørgensen Lone , Størmer Jan , Joakimsen Ragnar M
Published: September 2011

Despite reported bone loss during pregnancy and lactation, no study has shown deleterious long-term effects of parity or breastfeeding. Studies have shown higher bone mineral density and reduced risk for fracture in parous than in nulliparous women or no effect of parity and breastfeeding, so long-term effects are uncertain. We studied the effect of parity and breastfeeding on risk for hip, wrist and non-vertebral fragility fractures (hip, wrist, or proximal humerus) in 4681 postmenopausal women aged 50 to 94 years in the Tromsø Study from 1994–95 to 2010, using Cox's proportional hazard models. During 51 906 person-years, and a median of 14.5 years follow-up, 442, 621, and 1105 of 4681 women suffered incident hip, wrist, and fragility fractures, and the fracture rates were 7.8, 11.4, and 21.3 per 1000 person-years, respectively. The risk for hip, wrist, and fragility fracture did not differ between parous (n = 4230, 90.4%) and nulliparous women (n = 451, 9.6%). Compared with women who did not breast-feed after birth (n = 184, 4.9%), those who breastfed (n = 3564, 95.1%) had 50% lower risk for hip fracture (HR 0.50; 95% CI 0.32 to 0.78), and 27% lower risk for fragility fracture (HR 0.73; 95% CI 0.54 to 0.99), but similar risk for wrist fracture, after adjustment for age, BMI, height, physical activity, smoking, a history of diabetes, previous fracture of hip or wrist, use of hormone replacement therapy, and length of education. Each 10 months longer total duration of breastfeeding reduced the age-adjusted risk for hip fracture by 12% (HR 0.88; 95% CI 0.78 to 0.99, p for trend = 0.03) before, and marginally after, adjustment for BMI and other covariates (HR 0.91; 95% CI 0.80 to 1.04). In conclusion, this data indicates that pregnancy and breastfeeding has no long-term deleterious effect on bone fragility and fractures, and that breastfeeding may contribute to a reduced risk for hip fracture after menopause. © 2011 American Society for Bone and Mineral Research
Predicting fractures in an international cohort using risk factor algorithms without BMD
Authors: Sambrook Philip N , Flahive Julie , Hooven Fred H , Boonen Steven , Chapurlat Roland , Lindsay Robert , Nguyen Tuan V , Díez-Perez Adolfo , Pfeilschifter Johannes , Greenspan Susan L , Hosmer David , Netelenbos J Coen , Adachi Jonathan D , Watts Nelson B , Cooper Cyrus , Roux Christian , Rossini Maurizio , Siris Ethel S , Silverman Stuart , Saag Kenneth G , Compston Juliet E , LaCroix Andrea , Gehlbach Stephen
Published: September 2011

Clinical risk factors are associated with increased probability of fracture in postmenopausal women. We sought to compare prediction models using self-reported clinical risk factors, excluding BMD, to predict incident fracture among postmenopausal women. The GLOW study enrolled women aged 55 years or older from 723 primary-care practices in 10 countries. The population comprised 19,586 women aged 60 years or older who were not receiving antiosteoporosis medication and were followed annually for 2 years. Self-administered questionnaires were used to collect data on characteristics, fracture risk factors, previous fractures, and health status. The main outcome measure compares the C index for models using the WHO Fracture Risk (FRAX), the Garvan Fracture Risk Calculator (FRC), and a simple model using age and prior fracture. Over 2 years, 880 women reported incident fractures including 69 hip fractures, 468 “major fractures” (as defined by FRAX), and 583 “osteoporotic fractures” (as defined by FRC). Using baseline clinical risk factors, both FRAX and FRC showed a moderate ability to correctly order hip fracture times (C index for hip fracture 0.78 and 0.76, respectively). C indices for “major” and “osteoporotic” fractures showed lower values, at 0.61 and 0.64. Neither algorithm was better than the model based on age + fracture history alone (C index for hip fracture 0.78). In conclusion, estimation of fracture risk in an international primary-care population of postmenopausal women can be made using clinical risk factors alone without BMD. However, more sophisticated models incorporating multiple clinical risk factors including falls were not superior to more parsimonious models in predicting future fracture in this population. © 2011 American Society for Bone and Mineral Research
Therapeutic apheresis instrumentation
Authors: Wehrli Gay
Published: September 2011

This article provides a concise overview of therapeutic apheresis medicine instrumentation. Three instrument modalities are discussed: (1) centrifugation‐based instruments, (2) extracorporeal photopheresis instruments (a subset of centrifugation‐based instruments), and (3) column‐based instruments. © 2011 Wiley‐Liss, Inc.
Fast and accurate computation schemes for evaluating vibrational entropy of proteins
Authors: Xu Beisi , Shen Hujun , Zhu Xiao , Li Guohui
Published: September 2011

Standard normal mode analysis (NMA) method is able to calculate vibrational entropy of proteins, but it is computationally intensive, especially for large proteins. To evaluate vibrational entropy efficiently and accurately, we, here, propose computation schemes based on coarse‐grained NMA methods. This can be achieved by rescaling coarse‐grained results with a specific factor that is derived on the basis of the linear correlation of protein vibrational entropy between standard NMA and coarse‐grained NMA. Our coarse‐grained NMA computation schemes can repeat correctly and efficiently the results of standard NMA for large proteins. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Interactions between free radicals and a graphene fragment: Physical versus chemical bonding, charge transfer, and deformation
Authors: Wang Fengting T. , Chen Lei , Tian Chuanjin J. , Meng Yan , Wang Zhigang G. , Zhang Ruiqin Q. , Jin Mingxing X. , Zhang Ping , Ding Dajun J.
Published: September 2011

The adsorption of six free radicals (FRs) respectively on a graphene fragment was studied using a density functional tight‐binding method with the inclusion of an empirical dispersion term in total energy. The results indicate that the different interaction paths between the FRs and the graphene lead to different forms of physical (PA) or chemical adsorptions (CA). The CA appears only in the condition where some of the nonhydrogen atoms are closer to the graphene, with the deformation occurring in the latter. The charge transfer increases with the increase in adsorption energy in every FR‐graphene system. Although the deformation in the graphene is negligible in all PA cases, the FR is closer to the graphene and the graphene deformation is clearer in all CA cases, with all atomic displacements being larger than 0.1 Å. Our findings are useful not only for FR scavenging but also for studying the interaction between general molecules and material surfaces. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
A semiempirical long‐range corrected exchange correlation functional including a short‐range Gaussian attenuation (LCgau‐B97)
Authors: Song Jong‐Won , Peng Daoling , Hirao Kimihiko
Published: September 2011

We applied an improved long‐range correction scheme including a short‐range Gaussian attenuation (LCgau) to the Becke97 (B97) exchange correlation functional. In the optimization of LCgau‐B97 functional, the linear parameters are determined by least squares fitting. Optimizing μ parameter (0.2) that controls long‐range portion of Hartree‐Fock (HF) exchange to excitation energies of large molecules (Chai and Head‐Gordon, J Chem Phys 2008, 128, 084106) and additional short‐range Gaussian parameters (a = 0.15 and k = 0.9) that controls HF exchange inclusion ranging from short‐range to mid‐range (0.5–3 Å) to ground state properties achieved high performances of LCgau‐B97 simultaneously on both ground state and excited state properties, which is better than other tested semiempirical density functional theory (DFT) functionals, such as ωB97, ωB97X, BMK, and M0x‐family. We also found that while a small μ value (∼0.2) in LC‐DFT is appropriate to the local excitation and intramolecular charge‐transfer excitation energies, a larger μ value (0.42) is desirable in the Rydberg excitation‐energy calculations. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
A theoretical study of CO adsorption on gold by Hückel theory and density functional theory calculations
Authors: Sun Keju , Kohyama Masanori , Tanaka Shingo , Takeda Seiji
Published: September 2011

It is crucial to understand the nature of CO adsorption on gold so as to elucidate the mechanism of low‐temperature CO oxidation on nanogold catalysts. We performed theoretical analysis of CO adsorption on gold by using Hückel theory and density functional theory (DFT) calculations. Hückel theory indicates that CO adsorption on gold is dominated by the electron distribution at the Au atom, which is greatly affected by neighboring Au atoms, coadsorbed or doping species. The increase of σ‐bonding electrons should weaken the CO adsorption, while the increase of π‐electrons should strengthen the adsorption. DFT calculations proved this prediction quantitatively for various systems, including CO adsorption on a Au(100)‐hex surface with locally varying subsurface configurations and CO coadsorption with acceptor or donor species. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
A finite field method for calculating molecular polarizability tensors for arbitrary multipole rank
Authors: Elking Dennis M. , Perera Lalith , Duke Robert , Darden Thomas , Pedersen Lee G.
Published: September 2011

A finite field method for calculating spherical tensor molecular polarizability tensors αlm;l′m′ = ∂Δlm/∂ϕl′m′* by numerical derivatives of induced molecular multipole Δlm with respect to gradients of electrostatic potential ϕl′m′* is described for arbitrary multipole ranks l and l′. Interconversion formulae for transforming multipole moments and polarizability tensors between spherical and traceless Cartesian tensor conventions are derived. As an example, molecular polarizability tensors up to the hexadecapole–hexadecapole level are calculated for water using the following ab initio methods: Hartree–Fock (HF), Becke three‐parameter Lee‐Yang‐Parr exchange‐correlation functional (B3LYP), Møller–Plesset perturbation theory up to second order (MP2), and Coupled Cluster theory with single and double excitations (CCSD). In addition, intermolecular electrostatic and polarization energies calculated by molecular multipoles and polarizability tensors are compared with ab initio reference values calculated by the Reduced Variation Space method for several randomly oriented small molecule dimers separated by a large distance. It is discussed how higher order molecular polarizability tensors can be used as a tool for testing and developing new polarization models for future force fields. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Interplay between halogen bond and lithium bond in MCN‐LiCN‐XCCH (M = H, Li, and Na; X = Cl, Br, and I) complex: The enhancement of halogen bond by a lithium bond
Authors: Li Qingzhong , Li Ran , Liu Zhenbo , Li Wenzuo , Cheng Jianbo
Published: September 2011

Quantum chemical calculations have been performed to study the complex of MCN‐LiCN‐XCCH (M = H, Li, and Na; X = Cl, Br, and I). The aim is to study the cooperative effect between halogen bond and lithium bond. The alkali metal has an enhancing effect on the lithium bond, making it increased by 77 and 94% for the Li and Na, respectively. There is the cooperativity between the lithium bond and halogen bond. The former has a larger enhancing effect on the latter, being in a range of 11.7–29.4%. The effect of cooperativity on the halogen bond is dependent on the type of metal and halogen atoms. The enhancing mechanism has been analyzed in views with the orbital interaction, charge transfer, dipole moment, polarizability, atom charges, and electrostatic potentials. The results show that the electrostatic interaction plays an important role in the enhancement of halogen bond. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Theoretical insights on the electron doping and Curie temperature in La‐doped Sr2CrWO6
Authors: Wang Jing , Meng Jian , Wu Zhijian
Published: September 2011

The structure and electronic and magnetic properties of LaxSr2–xCrWO6 (x = 0.0, 0.5, 1.0, 1.5, 2.0) were investigated by using the density functional theory. With the increase of La doping, the extra electrons are injected into W 5d orbitals, which makes the spin moments of W increase. In addition, the calculated Curie temperature and total magnetic moments decrease with the increase of the electron doping, in agreement with the experimental observation. This also means that the decrease of Curie temperature with the electron doping is intrinsic. Half metallic properties are obtained for x = 0.0, 0.5, 1.5, and 2.0, whereas for x = 1.0, the compound is semiconducting. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
The complete (k, 3)‐arcs of PG(2,q),q≤13
Authors: Coolsaet K. , Sticker H.
Published: September 2011

We have classified by computer the projectively distinct complete (k,3)‐arcs inPG(2,q),q≤13. The algorithm used is an application of isomorph‐free backtracking using canonical augmentation, an adaptation of our earlier algorithms for the generation of (k,2)‐arcs. We describe those parts of the algorithms which are specific to the particular problem of (k,3)‐arcs. For each of these arcs we have also determined the automorphism group. The results are summarized in tables where the arcs are listed according to size and automorphism group. For the arcs with the larger automorphism groups, explicit descriptions are given. Part of the computer results can be generalized to other values ofq: we describe constructions of arcs havingS4as a group of automorphisms, arcs containing the union of three “half conics” and arcs constructed from parts of cubic curves. Copyright © 2011 Wiley Periodicals, Inc. J Combin Designs 20:89‐111, 2012
Comments on 3‐blocked designs
Authors: Ward Harold N.
Published: September 2011

This note provides a correction and some additions to a 1999 article by Luigia Berardi and Fulvio Zuanni on blocking 3‐sets in designs. © 2012 Wiley Periodicals, Inc. J. Combin. Designs 20: 328–331, 2012
Biembedding Abelian groups with mates having transversals
Authors: Grannell M. J. , Knor M.
Published: September 2011

A certain recursive construction for biembeddings of Latin squares has played a substantial role in generating large numbers of nonisomorphic triangular embeddings of complete graphs. In this article, we prove that, except for the groups and C4, each Latin square formed from the Cayley table of an Abelian group appears in a biembedding in which the second Latin square has a transversal. Such biembeddings may then be freely used as ingredients in the recursive construction. Copyright © 2011 Wiley Periodicals, Inc. J Combin Designs 20:81‐88, 2012
CD73‐generated adenosine promotes osteoblast differentiation
Authors: Takedachi Masahide , Oohara Hiroyuki , Smith Brenda J. , Iyama Mitsuyoshi , Kobashi Mariko , Maeda Kenichiro , Long Courtney L. , Humphrey Mary B. , Stoecker Barbara J. , Toyosawa Satoru , Thompson Linda F. , Murakami Shinya
Published: September 2011

CD731 is a GPI‐anchored cell surface protein with ecto‐5′‐nucleotidase enzyme activity that plays a crucial role in adenosine production. While the roles of adenosine receptors (AR) on osteoblasts and osteoclasts have been unveiled to some extent, the roles of CD73 and CD73‐generated adenosine in bone tissue are largely unknown. To address this issue, we first analyzed the bone phenotype of CD73‐deficient (cd73−/−) mice. The mutant male mice showed osteopenia, with significant decreases of osteoblastic markers. Levels of osteoclastic markers were, however, comparable to those of wild‐type mice. A series of in vitro studies revealed that CD73 deficiency resulted in impairment in osteoblast differentiation but not in the number of osteoblast progenitors. In addition, over expression of CD73 on MC3T3‐E1 cells resulted in enhanced osteoblastic differentiation. Moreover, MC3T3‐E1 cells expressed adenosine A2A receptors (A2AAR) and A2B receptors (A2BAR) and expression of these receptors increased with osteoblastic differentiation. Enhanced expression of osteocalcin (OC) and bone sialoprotein (BSP) observed in MC3T3‐E1 cells over expressing CD73 were suppressed by treatment with an A2BAR antagonist but not with an A2AAR antagonist. Collectively, our results indicate that CD73 generated adenosine positively regulates osteoblast differentiation via A2BAR signaling. J. Cell. Physiol. 227: 2622–2631, 2012. © 2011 Wiley Periodicals, Inc.
Experimental studies on the effect of inert gases on diffusion distillation of ethanol–water mixtures
Authors: Singh Neetu , Prasad Ram
Published: September 2011

BACKGROUND: Diffusion distillation of ethanol–water mixtures in the presence of air as an inert gas has been used to produce fuel grade ethanol, and studies on the effect of vaporization temperature and feed composition on the selectivity and total molar flux have been presented recently. This paper describes the separation of ethanol–water mixtures by diffusion distillation in the presence of light and heavy inert gases such as helium and argon and reports the changes in selectivity and total molar flux in comparison with those in air.

RESULTS: Total molar flux in the presence of light inert gases like helium increases rapidly with vaporization temperature but at the cost of reduced selectivity. The use of heavy inert gases like argon results in increased selectivity but total molar flux decreases. Compared with helium and air at a constant temperature, the quantity Saz(N2/N1) is found to be higher for argon.

CONCLUSIONS: Experimental results demonstrate that a high degree of separation can be achieved by using heavy inert gases. The higher value of the quantity Saz(N2/N1) for argon indicates that the heavy inert gas results in enhanced separation. The light inert gas can be used if high transfer rates are required at low vaporization temperature. The quantity Saz(N2/N1) can be used not only for vaporization temperature optimization but also for selecting the appropriate inert gas for the process. Copyright © 2011 Society of Chemical Industry
Every 4‐Colorable Graph With Maximum Degree 4 Has an Equitable 4‐Coloring
Authors: Kierstead H. A. , Kostochka A. V.
Published: September 2011

Chen et al., conjectured that for r≥3, the only connected graphs with maximum degree at most r that are not equitably r‐colorable are Kr, r (for odd r) and Kr + 1. If true, this would be a joint strengthening of the Hajnal–Szemerédi theorem and Brooks' theorem. Chen et al., proved that their conjecture holds for r = 3. In this article we study properties of the hypothetical minimum counter‐examples to this conjecture and the structure of “optimal” colorings of such graphs. Using these properties and structure, we show that the Chen–Lih–Wu Conjecture holds for r≤4. © 2011 Wiley Periodicals, Inc. J Graph Theory 71:31–48, 2012
POVERTY AND WELFARE OF THE POOR IN A HIGH‐INCOME COUNTRY: EVIDENCE FROM TRINIDAD AND TOBAGO
Authors: Kedir Abbi M. , Sookram Sandra
Published: September 2011

Trinidad and Tobago has a non‐negligible proportion of its population in poverty. After constructing a household consumption aggregate adjusted for price and household composition differentials, we measured the rate of poverty and examined the determinants of poverty and household welfare on the basis of the Survey of Living Conditions 2005 data set. Relevant econometric techniques were adopted to identify the probability of being poor for all households and household welfare for a sample of only poor households. Our findings indicate that the poverty rate is higher than the existing estimates and socioeconomic and demographic characteristics play significant roles in poverty and household welfare. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis of 2H‐ and 14C‐labeled fexinidazole and its primary metabolites labeled with 2H
Authors: Fontana E. , Pignatti Alberto , Venegoni Serena , Bray Michael A.
Published: September 2011

The preparation of deuterium labeled fexinidazole, a 5‐nitroimidazole drug candidate for the treatment of Human African Trypanosomiasis, and its two main metabolites (fexinidazole sulfoxide and fexinidazole sulfone) for use as internal standards for liquid chromatography‐mass spectrometry are reported. Additionally, the synthesis of a 14 C‐labeled version of fexinidazole for absorption, distribution, metabolism, and excretion studies is also described via a five‐step procedure starting from commercially available potassium [14 C]cyanide. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis of potent lymphocyte function‐associated antigen‐1 inhibitors labeled with carbon‐14 and deuterium, part 1
Authors: Latli Bachir , Byrne Denis , Nummy Larry , Krishnamurthy Dhileepkumar , Senanayake Chris H.
Published: September 2011

The lymphocyte function‐associated antigen‐1 (LFA‐1) is an essential component in normal immune system function and is a target for drug discovery for its broad therapeutic potential in treating inflammatory diseases. Here, we report the synthesis of three potent antagonists of LFA‐1 labeled with carbon‐14 and deuterium to support drug metabolism and pharmacokinetics studies. Carbon‐14 labeled (R)‐1‐acetyl‐5‐(4‐bromobenzyl)‐3‐(3,5‐dichlorophenyl)‐5‐methyl‐imidazolidine‐2,4‐dione (1) was prepared in 27% radiochemical yield in two steps and with a specific activity of 2.1 GBq/mmol by using [14C]‐phosgene. Carbon‐14 labeled 5‐bromopyrimidine was used to prepare (R)‐5‐(1‐piperazinylsulfonyl)‐1‐(3,5‐dichlorophenyl)‐3‐[4‐(5‐pyrimidinyl)benzyl]‐3‐methyl‐1‐H‐imidazo[1,2a]imidazol‐2‐one (2) and (R)‐1‐[7‐(3,5‐dichlorophenyl)‐5‐methyl‐6‐oxo‐5‐(4‐pyrimidin‐5‐yl‐benzyl)‐6,7‐dihydro‐5H‐imidazo[1,2‐a]imidazole‐3‐sulfonyl]piperidin‐4‐carboxylic acid amide (3) via a Suzuki reaction with the corresponding boronic acid esters in 42% and 67% radiochemical yield and specific activities of 1.85 GBq/mmol and 1.95 GBq/mmol, respectively. Deuterium labeled piperazine was reacted with the sulfonyl chloride derivative (7), followed by a Suzuki coupling to the pyrimidine boronic ester to give deuterium labeled (2) in 47% yield. Deuterium labeled isonipecotamide was reacted in a similar way with the sulfonyl chloride derivative (14) to furnish deuterium labeled (3) in one step and in 94% yield. Copyright © 2011 John Wiley & Sons, Ltd.
Proline substitutions and threonine pseudophosphorylation of the SH3 ligand of 18.5‐kDa myelin basic protein decrease its affinity for the Fyn‐SH3 domain and alter process development and protein localization in oligodendrocytes
Authors: Smith Graham S.T. , De Avila Miguel , Paez Pablo M. , Spreuer Vilma , Wills Melanie K.B. , Jones Nina , Boggs Joan M. , Harauz George
Published: September 2011

The developmentally regulated myelin basic proteins (MBPs), which arise from the golli (gene of oligodendrocyte lineage) complex, are highly positively charged, intrinsically disordered, multifunctional proteins having several alternatively spliced isoforms and posttranslational modifications, and they play key roles in myelin compaction. The classic 18.5‐kDa MBP isoform has a proline‐rich region comprising amino acids 92–99 (murine sequence –T92PRTPPPS99–) that contains a minimal SH3 ligand domain. We have previously shown that 18.5‐kDa MBP binds to several SH3 domains, including that of Fyn, a member of the Src family of tyrosine kinases involved in a number of signaling pathways during CNS development. To determine the physiological role of this binding as well as the role of phosphorylation of Thr92 and Thr95, in the current study we have produced several MBP variants specifically targeting phosphorylation sites and key structural regions of MBP's SH3 ligand domain. Using isothermal titration calorimetry, we have demonstrated that, compared with the wild‐type protein, these variants have lower affinity for the SH3 domain of Fyn. Moreover, overexpression of N‐terminal‐tagged GFP versions in immortalized oligodendroglial N19 and N20.1 cell cultures results in aberrant elongation of membrane processes and increased branching complexity and inhibits the ability of MBP to decrease Ca2+ influx. Phosphorylation of Thr92 can also cause MBP to traffic to the nucleus, where it may participate in additional protein–protein interactions. Coexpression of MBP with a constitutively active form of Fyn kinase resulted in membrane process elaboration, a phenomenon that was abolished by point amino acid substitutions in MBP's SH3 ligand domain. These results suggest that MBP's SH3 ligand domain plays a key role in intracellular protein interactions in vivo and may be required for proper membrane elaboration of developing oligodendrocytes and, further, that phosphorylation of Thr92 and Thr95 can regulate this function. © 2011 Wiley Periodicals, Inc.
Cloning and extracellular expression of inulin fructotransferase from Arthrobacter aurescens SK 8.001 in E. coli
Authors: Zhao Meng , Mu Wanmeng , Jiang Bo , Hang Hua , Zhou Liuming , Zhang Tao
Published: September 2011

BACKGROUND: Difructose anhydride (DFA) III is a natural and low‐calorie sweetener. It stimulates the absorption of calcium and other minerals. Inulin fructotransferase (IFTase; EC 4.2.2.18), catalysing inulin hydrolysis to DFA III, is considered to be the most promising enzyme for the production of DFA III.

RESULTS: IFTase gene from Arthrobacter aurescens SK 8.001 was cloned and sequenced. Transformant with native IFTase signal peptide was a useful system for extracellular over‐expression of IFTase, and its extracellular IFTase activity reached 81.0 U mL−1. This value was 4.1‐fold of that obtained with A. aurescens SK 8.001 for IFTase production. The recombinant IFTase was purified to electrophoretical homogeneity and characterized. The enzyme showed maximum activity at pH 6.0 and 55 °C, and retained 81.3% of its initial activity after incubation at 60 °C for 4 h.

CONCLUSION: IFTase gene from A. aurescens SK 8.001 was cloned, sequenced and over‐expressed in E. coli. IFTase was reported for the first time to be over‐expressed extracellularly. The recombinant IFTase was purified and characterized, and shown to be a good candidate for potential application in DFA III production. Copyright © 2011 Society of Chemical Industry
Prognostic significance of high podoplanin expression after chemoradiotherapy in esophageal squamous cell carcinoma patients
Authors: Chao Yin‐Kai , Chuang Wen‐Yu , Yeh Chi‐Ju , Wu Yi‐Cheng , Liu Yun‐Hen , Hsieh Ming‐Ju , Cheng Ann‐Joy , Hsueh Chuen , Liu Hui‐Ping
Published: September 2011

Background

The correlation between high tumor podoplanin (PP) immunoreactivity and poor outcome in patients with non‐chemoradiotherapy(CRT) pretreated upper aerodigestive tract squamous cell carcinoma (SCC) has been reported recently. Little is known about the implication of PP expression after CRT. Therefore, we conducted this study.

Methods

We evaluated the PP immunoreactivity in ypT3N0 esophageal SCC patients by using immunohistochemistry. The impact of PP expression intensity in tumors on patient survival was judged in combination with clinical and pathological descriptors.

Results

Our study included 109 males and 4 females (mean age, 57.6 years; range, 38–79 years). PP immunoreactivity was expressed in tumors in 95% of patients and 38% of patients had high PP expression. High PP expression tumors had positive association with lymphovascular invasion (LVI). Multivariate analyses revealed tumor PP immunoreactivity and circumferential resection margin (CRM) status as independent prognostic factors. Patients with positive CRM and high PP expression had shortest survival followed by those with either positive CRM or high PP expression, and then by patients with neither positive CRM nor high PP expression (5‐year disease‐specific survival: 5%, 20%, 40%, P < 0.001).

Conclusion

Tumor PP immunoreactivity in conjunction with CRM status are useful markers to identify aggressive post‐CRT treated ypT3N0 stage esophageal SCC. J. Surg. Oncol. 2012; 105:183–188. © 2011 Wiley Periodicals, Inc.
Gastric cancer: Biology and clinical manifestations in Israel
Authors: Dreznik Ayelet , Purim Ofer , Idelevich Efraim , Kundel Yulia , Sulkes Jaqueline , Sulkes Aaron , Brenner Baruch
Published: September 2011

Background

Gastric cancer (GC) in Israel remains incompletely characterized. The aim of this study was to define the clinical and pathological characteristics of GC in Israel and to compare them to the general Western population.

Patients and Methods

This is a retrospective analysis of 461 consecutive GC patients treated at a single institution between 1995 and 2007. Epidemiological and clinical‐pathological data were retrieved from the patients' medical files and the institutional electronic database and analyzed using standard statistical methods.

Results

Epidemiology, clinical manifestations, histopathological findings, clinical course, and prognostic factors for disease outcome were all similar to those reported in the Western literature. Findings unique to the Israeli population included: (1) rarity of GC‐associated risk factors; (2) increased GC incidence in Ashkenazi Jews; (3) high incidence of second primary malignancy and family history of cancer; and (4) no dominancy of proximal GCs.

Conclusion

There do not appear to be any major differences in the biology or clinical manifestations of GC in Israel. Western recommendations for diagnosis and treatment of GC may therefore be applied to the Israeli patient population. J. Surg. Oncol. 2012; 105:316–322. © 2011 Wiley Periodicals, Inc.