bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication of Supercapacitors using Carbon Microspheres Synthesized from Resorcinol–Formaldehyde Resin
Authors: Ren Suzhen , Wang Meng , Jia Cuiying , Hao Ce , Wang Xuzhen
Published: May 2013

A versatile procedure is investigated for the synthesis of carbon microspheres from resorcinol–formaldehyde (RF) resin and various catalysts, such as boric acid (H3BO3), hydrochloric acid (HCl), sulfuric acid (H2SO4), nitric acid (HNO3), ammonia (NH3⋅H2O), and sodium hydroxide (NaOH). Among the catalysts investigated in this work, ammonia is the most efficient for precisely controlling the size and morphology of the RF‐resin microspheres. Furthermore, the carbon microspheres (CRF‐6) derived from the RF‐6 resin microspheres that were synthesized by using the ammonia catalyst result in a high surface area: SBET of 473 m2 g−1 and Vtotal of 0.287 cm3 g−1. As a supercapacitor electrode material, they present a low resistance value (R) of 0.5 Ω in 6 mol L−1 KOH electrolyte. The maximum specific capacitance of the electrode measured by using cyclic voltammetry reaches 175.9 F g−1 at a scan rate of 1 mV s−1 and 139.5 F g−1 at a current density of 1 A g−1 from galvanostatic charge–discharge measurements. The specific capacitance only decays 5.6 % after 500 cycles, which indicates that the sample possesses excellent cycle durability. The present study shows that the carbon microspheres synthesized using RF resin are electrically conductive materials with reduced mass‐transport resistance and improved supercapacitor performance reliability.
Network‐coding‐based multisource multirelay LDPC‐coded cooperative MIMO
Authors: Zhang Shunwai , Yang Fengfan , Tang Lei
Published: May 2013

This paper investigates a network‐coding‐based multisource multirelay low‐density parity‐check coded cooperative multiple‐input multiple‐output scheme, where multiple receiving antennas are applied in the destination. Each relay cooperates with multiple sources via network coding. A joint iterative decoding is effectively carried out in the destination. The decoding algorithm agrees with the introduced equivalent joint Tanner graph that can be used to fully characterise low‐density parity‐check codes employed by the sources and relays. The outage probability of the network‐coding‐based coded cooperative multiple‐input multiple‐output scheme over Rayleigh fading channels is analysed, when maximal‐ratio combining is adopted in the destination. Theoretical analysis and numerical simulations show that the investigated scheme can well combine cooperation diversity, multireceive diversity and channel coding gains, and clearly outperforms the coded noncooperation scheme under the same conditions. Copyright © 2013 John Wiley & Sons, Ltd.
An attempt to improve accuracy of higher‐order statistics and spectra in direct numerical simulation of incompressible wall turbulence by using the compact schemes for viscous terms
Authors: Suzuki H. , Nagata K. , Sakai Y. , Hayase T. , Hasegawa Y. , Ushijima T.
Published: May 2013

We attempt to improve accuracy in the high‐wavenumber region in DNS of incompressible wall turbulence such as found in fully developed turbulent channel flow. In particular, it is shown that the improvement of accuracy of viscous terms in the Navier–Stokes equations leads to the improvement of accuracy of higher‐order statistics and various spectra. It is emphasized that increase in required computational cost will not be crucial when incompressible flow is simulated, because the introduction of a higher‐order scheme into the viscous terms does not increase computational cost for solving the Poisson equation. We introduced fourth‐order and eighth‐order central compact schemes for discretizing the viscous terms in DNS of a fully developed turbulent channel flow. The results are compared with those using second‐order and fourth‐order central‐difference schemes applied to the viscous terms and those obtained by the spectral method. The results show that accuracy improvement of the viscous terms improve accuracy of higher‐order statistics (i.e., skewness and flatness factors of streamwise velocity fluctuation) and various spectra of velocity and pressure fluctuations in the high‐wavenumber region. Copyright © 2013 John Wiley & Sons, Ltd.
THEMIS observations of the magnetopause electron diffusion region: Large amplitude waves and heated electrons
Authors: Tang Xiangwei , Cattell Cynthia , Dombeck John , Dai Lei , Wilson Lynn B. , Breneman Aaron , Hupach Adam
Published: May 2013

We present the first observations of large amplitude waves in a well‐defined electron diffusion region based on the criteria described by Scudder et al. [2012] at the subsolar magnetopause using data from one Time History of Events and Macroscale Interactions during Substorms (THEMIS) satellite. These waves identified as whistler mode waves, electrostatic solitary waves, lower hybrid waves, and electrostatic electron cyclotron waves, are observed in the same 12 s waveform capture and in association with signatures of active magnetic reconnection. The large amplitude waves in the electron diffusion region are coincident with abrupt increases in electron parallel temperature suggesting strong wave heating. The whistler mode waves, which are at the electron scale and which enable us to probe electron dynamics in the diffusion region were analyzed in detail. The energetic electrons (~30 keV) within the electron diffusion region have anisotropic distributions with Te ⊥/Te ∥ > 1 that may provide the free energy for the whistler mode waves. The energetic anisotropic electrons may be produced during the reconnection process. The whistler mode waves propagate away from the center of the “X‐line” along magnetic field lines, suggesting that the electron diffusion region is a possible source region of the whistler mode waves.
Do diurnal aerosol changes affect daily average radiative forcing?
Authors: Kassianov Evgueni , Barnard James , Pekour Mikhail , Berg Larry K. , Michalsky Joseph , Lantz Kathy , Hodges Gary
Published: May 2013

Strong diurnal variability of aerosol has been observed frequently for many urban/industrial regions. How this variability may alter the direct aerosol radiative forcing (DARF), however, is largely unknown. To quantify changes in the time‐averaged DARF, we perform an assessment of 29 days of high temporal resolution ground‐based data collected during the Two‐Column Aerosol Project on Cape Cod, which is downwind of metropolitan areas. We demonstrate that strong diurnal changes of aerosol loading (about 20% on average) have a negligible impact on the 24‐h average DARF when daily averaged optical properties are used to find this quantity. However, when there is a sparse temporal sampling of aerosol properties, which may preclude the calculation of daily averaged optical properties, large errors (up to 100%) in the computed DARF may occur. We describe a simple way of reducing these errors, which suggests the minimal temporal sampling needed to accurately find the forcing.
Is land subsidence increasing the exposure to sea level rise in Alexandria, Egypt?
Authors: Wöppelmann Guy , Le Cozannet Gonéri , de Michele Marcello , Raucoules Daniel , Cazenave Anny , Garcin Manuel , Hanson Susan , Marcos Marta , Santamaría‐Gómez Alvaro
Published: May 2013

Delta margins are subject to relatively high rates of land subsidence and have the potential to significantly exacerbate future changes in sea levels predicted by global warming models used in impact studies. Through a combined analysis of GPS and persistent scatterer interferometry data, we determine that most of the coastline of Alexandria has been subject to moderate land subsidence over the past decade (0.4 mm/yr on average and up to 2 mm/yr locally). This contrasts to previous studies that suggested subsidence in excess of 3 mm/yr. Based on our findings, we infer that on multi‐century to millennia timescales, land subsidence in the area of Alexandria is dominated by tectonic setting and earthquakes or gravitational collapse episodes of a growth fault, whereas on shorter interseismic decadal to century timescales, subsidence rates are likely steady and moderate, in agreement with natural compaction and dewatering of the observed Holocene sediment layer.
Primary sclerosing cholangitis, autoimmune hepatitis, and overlap in utah children: Epidemiology and natural history
Authors: Deneau Mark , Jensen Kyle M. , Holmen John , Williams Marc S. , Book Linda S. , Guthery Stephen L.
Published: May 2013

The epidemiology and natural history of pediatric primary sclerosing cholangitis (PSC), autoimmune sclerosing cholangitis (ASC), and autoimmune hepatitis (AIH) are not well characterized. Using multiple, overlapping search strategies followed by a detailed records review, we identified all cases of pediatric PSC, ASC, AIH, and inflammatory bowel disease (IBD) in a geographically isolated region of the United States. We identified 607 cases of IBD, 29 cases of PSC, 12 cases of ASC, and 44 cases of AIH. The mean age at diagnosis was 13.0 years for PSC, 11.3 years for ASC, and 9.8 years for AIH. The incidence and prevalence of PSC, ASC, and AIH were 0.2 and 1.5 cases, 0.1 and 0.6 cases, and 0.4 and 3.0 cases per 100,000 children, respectively. The mean duration of follow-up was 5.9 years. The probability of developing complicated liver disease within 5 years of the diagnosis of liver disease was 37% [95% confidence interval (CI) = 21%-58%] for PSC, 25% (95% CI = 7%-70%) for ASC, and 15% (95% CI = 7%-33%) for AIH. The 5-year survival rates with the native liver were 78% (95% CI = 54%-91%) for PSC, 90% (95% CI = 47%-99%) for ASC, and 87% (95% CI = 71%-95%) for AIH. Cholangiocarcinoma developed in 2 of the 29 PSC patients (6.9%). PSC occurred in 9.9% of patients with ulcerative colitis (UC) and in 0.6% of patients with Crohn's disease (CD). ASC occurred in 2.3% of UC patients and 0.9% of CD patients. AIH occurred in 0.4% of UC patients and in 0.3% of CD patients. Liver disease occurred in 39 of 607 IBD patients (6.4%) overall.

Conclusion

: Immune-mediated liver diseases are important sources of morbidity in children. Using a population-based design, this study quantifies the burden and natural history of immune-mediated liver disease in children. (Hepatology 2013;58:1392–1400)
Clinical and histological determinants of nonalcoholic steatohepatitis and advanced fibrosis in elderly patients
Authors: Noureddin Mazen , Yates Katherine P. , Vaughn Ivana A. , Neuschwander-Tetri Brent A. , Sanyal Arun J. , McCullough Arthur , Merriman Raphael , Hameed Bilal , Doo Edward , Kleiner David E. , Behling Cynthia , Loomba Rohit
Published: May 2013

The characteristics of nonalcoholic fatty liver disease (NAFLD) in elderly patients are unknown. Therefore, we aimed to examine the differences between elderly and nonelderly patients with NAFLD and to identify determinants of nonalcoholic steatohepatitis (NASH) and advanced fibrosis (bridging fibrosis or cirrhosis) in elderly patients. This is a cross-sectional analysis of adult participants who were prospectively enrolled in the NASH Clinical Research Network studies. Participants were included based on availability of the centrally reviewed liver histology data within 1 year of enrollment, resulting in 61 elderly (age ≥65 years) and 735 nonelderly (18-64 years) participants. The main outcomes were the presence of NASH and advanced fibrosis. Compared to nonelderly patients with NAFLD, elderly patients had a higher prevalence of NASH (56% versus 72%,

P

= 0.02), and advanced fibrosis (25% versus 44%,

P

= 0.002). Compared to nonelderly patients with NASH, elderly patients with NASH had higher rates of advanced fibrosis (35% versus 52%,

P

= 0.03), as well as other features of severe liver disease including the presence of ballooning degeneration, acidophil bodies, megamitochondria, and Mallory-Denk bodies (

P

≤ 0.05 for each). In multiple logistic regression analyses, independent determinants of NASH in elderly patients included higher aspartate aminotransferase (AST) (odds ratio [OR] = 1.12,

P

= 0.007) and lower platelets (OR = 0.98,

P

= 0.02); and independent determinants of advanced fibrosis included higher AST (OR = 1.08,

P

= 0.007), lower alanine aminotransferase value (OR = 0.91,

P

= 0.002), and an increased odds of having low high-density lipoprotein (OR = 8.35,

P

= 0.02).

Conclusion:

Elderly patients are more likely to have NASH and advanced fibrosis than nonelderly patients with NAFLD. Liver biopsy may be considered in elderly patients and treatment should be initiated in those with NASH and advanced fibrosis. (Hepatology 2013;58:1644–1654)
Adjuvant Gemcitabine Therapy Improves Survival in A Locally Induced, R0-Resectable Model of Metastatic Intrahepatic Cholangiocarcinoma
Authors: Gürlevik Engin , Fleischmann-Mundt Bettina , Armbrecht Nina , Longerich Thomas , Woller Norman , Kloos Arnold , Hoffmann Dirk , Schambach Axel , Wirth Thomas C. , Manns Michael P. , Zender Lars , Kubicka Stefan , Kühnel Florian
Published: May 2013

Complete surgical tumor resection (R0) for treatment of intrahepatic cholangiocarcinoma (ICC) is potentially curative, but the prognosis remains dismal due to frequent tumor recurrence and metastasis after surgery. Adjuvant therapies may improve the outcome, but clinical studies for an adjuvant approach are difficult and time-consuming for rare tumor entities. Therefore, animal models reflecting the clinical situation are urgently needed to investigate novel adjuvant therapies. To establish a mouse model of resectable cholangiocarcinoma including the most frequent genetic alterations of human ICC, we electroporated Sleeping Beauty-based oncogenic transposon plasmids into the left liver lobe of mice. KRas-activation in combination with p53-knockout in hepatocytes resulted in formation of a single ICC nodule within 3-5 weeks. Lineage tracing analyses confirmed the development of ICC by transdifferentiation of hepatocytes. Histologic examination demonstrated that no extrahepatic metastases were detectable during primary tumor progression. However, formation of tumor satellites close to the primary tumor and vascular invasion were observed, indicating early invasion into normal tissue adjacent to the tumor. After R0-resection of the primary tumor, we were able to prolong median survival, thereby observing tumor stage-dependent local recurrence, peritoneal carcinomatosis, and lung metastasis. Adjuvant gemcitabine chemotherapy after R0-resection significantly improved median survival of treated animals. Conclusion: We have developed a murine model of single, R0-resectable ICC with favorable characteristics for the study of recurrence patterns and mechanisms of metastasis after resection. This model holds great promise for preclinical evaluation of novel multimodal or adjuvant therapies to prevent recurrence and metastasis after R0-resection. (Hepatology 2013;53:1031–1041)
Adipose Tissue-Derived Stem Cells As A Regenerative Therapy for A Mouse Steatohepatitis-Induced Cirrhosis Model
Authors: Seki Akihiro , Sakai Yoshio , Komura Takuya , Nasti Alessandro , Yoshida Keiko , Higashimoto Mami , Honda Masao , Usui Soichiro , Takamura Masayuki , Takamura Toshinari , Ochiya Takahiro , Furuichi Kengo , Wada Takashi , Kaneko Shuichi
Published: May 2013

Cirrhosis is a chronic liver disease that impairs hepatic function and causes advanced fibrosis. Mesenchymal stem cells have gained recent popularity as a regenerative therapy since they possess immunomodulatory functions. We found that injected adipose tissue-derived stem cells (ADSCs) reside in the liver. Injection of ADSCs also restores albumin expression in hepatic parenchymal cells and ameliorates fibrosis in a nonalcoholic steatohepatitis model of cirrhosis in mice. Gene expression analysis of the liver identifies up- and down-regulation of genes, indicating regeneration/repair and anti-inflammatory processes following ADSC injection. ADSC treatment also decreases the number of intrahepatic infiltrating CD11b+ and Gr-1+ cells and reduces the ratio of CD8+/CD4+ cells in hepatic inflammatory cells. This is consistent with down-regulation of genes in hepatic inflammatory cells related to antigen presentation and helper T-cell activation. Conclusion: These results suggest that ADSC therapy is beneficial in cirrhosis, as it can repair and restore the function of the impaired liver. (Hepatology 2013;53:1133–1142)
Invariant NKT cell activation induces neutrophil accumulation and hepatitis: Opposite regulation by IL-4 and IFN-γ
Authors: Wang Hua , Feng Dechun , Park Ogyi , Yin Shi , Gao Bin
Published: May 2013

Alpha-Galactosylceramide (α-Galcer), a specific agonist for invariant natural killer T (iNKT) cells, is being evaluated in clinical trials for the treatment of viral hepatitis and liver cancer. However, the results from α-Galcer treatment are mixed, partially because of the variety of cytokines produced by activated iNKT cells that have an unknown synergistic effect on the progression of liver disease. It is well documented that injection of α-Galcer induces mild hepatitis with a rapid elevation in the levels of interleukin (IL)−4 and a delayed elevation in the levels of interferon-gamma (IFN-γ), and both of these cytokines are thought to mediate many functions of iNKT cells. Surprisingly, genetic deletion of both IL-4 and IFN-γ aggravated, rather than abolished, α-Galcer-induced iNKT hepatitis. Moreover, genetic ablation of IL-4, the IL-4 receptor, or its downstream signaling molecule signal transducer and activator of transcription (STAT)6 ameliorated α-Galcer-induced neutrophil infiltration, liver injury, and hepatitis. In contrast, genetic deletion of IFN-γ, the IFN-γ receptor, or its downstream signaling molecule STAT1 enhanced liver neutrophil accumulation, thereby exacerbating liver injury and hepatitis. Moreover, depletion of neutrophils eradicated α-Galcer-induced liver injury in wild-type, STAT1 knockout, and IFN-γ knockout mice.

Conclusion

: Our results propose a model in which activated iNKT cells rapidly release IL-4, which promotes neutrophil survival and hepatitis but also sequentially produce IFN-γ, which acts in a negative feedback loop to ameliorate iNKT hepatitis by inducing neutrophil apoptosis. Thus, modification of iNKT production of IL-4 and IFN-γ may have the potential to improve the efficacy of α-Galcer in the treatment of liver disease. (Hepatology 2013;58:1474–1485)
Bevacizumab: Finding its niche in the treatment of heart failure secondary to liver vascular malformations in hereditary hemorrhagic telangiectasia
Authors: Young Lawrence H. , Henderson Katharine J. , White Robert I. , Garcia-Tsao Guadalupe
Published: May 2013

Abstract

Context: The only treatment available to restore normal cardiac output in patients with hereditary hemorrhagic telangiectasia (HHT) and cardiac failure is liver transplant. Anti-vascular endothelial growth factor treatments such as bevacizumab may be an effective treatment. Objectives: To test the efficacy of bevacizumab in reducing high cardiac output in severe hepatic forms of HHT and to assess improvement in epistaxis duration and quality of life. Design, Setting, and Patients: Single-center, phase 2 trial with national recruitment from the French HHT Network. Patients were 18 to 70 years old and had confirmed HHT, severe liver involvement, and a high cardiac index related to HHT. Intervention: Bevacizumab, 5 mg per kg, every 14 days for a total of 6 injections. The total duration of the treatment was 2.5 months; patients were followed up for 6 months after the beginning of the treatment. Main Outcome Measure: Decrease in cardiac output at 3 months after the first injection, evaluated by echocardiography. Results: A total of 25 patients were included between March 2009 and November 2010. Of the 24 patients who had echocardiograms available for reread, there was a response in 20 of 24 patients with normalization of cardiac index (complete response [CR]) in 3 of 24, partial response (PR) in 17 of 24, and no response in 4 cases. Median cardiac index at beginning of the treatment was 5.05 L/min/m2 (range, 4.1-6.2) and significantly decreased at 3 months after the beginning of the treatment with a median cardiac index of 4.2 L/min/m2 (range, 2.9-5.2; P = .001). Median cardiac index at 6 months was significantly lower than before treatment (4.1 L/min/m2; range, 3.0-5.1). Among 23 patients with available data at 6 months, we observed CR in 5 cases, PR in 15 cases, and no response in 3 cases. Mean duration of epistaxis, which was 221 minutes per month (range, 0-947) at inclusion, had significantly decreased at 3 months (134 minutes; range, 0-656) and 6 months (43 minutes; range, 0-310) (P = .008). Quality of life had significantly improved. The most severe adverse events were 2 cases of grade 3 systemic hypertension, which were successfully treated. Conclusion: In this preliminary study of patients with HHT associated with severe hepatic vascular malformations and high cardiac output, administration of bevacizumab was associated with a decrease in cardiac output and reduced duration and number of episodes of epistaxis.
Synthesis of Functionalized H‐[1]Benzopyrano[2,3‐b]pyridines by the Friedländer Approach: Antimycobacterial and Antimicrobial Profile
Authors: Haveliwala Dhaval D. , Kamdar Nimesh R. , Mistry Prashant T. , Patel Saurabh K.
Published: May 2013

A series of functionalized H‐[1]benzopyrano[2,3‐b]pyridine derivatives were synthesized by the Friedländer reaction of 2‐amino‐4‐oxo‐4H‐chromene‐3‐carbonitriles 1 with malononitrile, ethyl cyanoacetate, or acetophenone (Scheme). The synthesized compounds 2–4 were screened for their in vitro activity against antitubercular, antibacterial, and antifungal species (Fig., Table). Among the synthesized compounds, 3c and 4f were the most active with 99% inhibition against Mycobacterium tuberculosis H37Rv, while compounds 2f, 3f, and 4d exhibited 69%, 63%, and 61% inhibition, respectively. The 4‐amino‐7,9‐dibromo‐1,5‐dihydro‐2,5‐dioxo‐2H‐chromeno[2,3‐b]pyridine‐3‐carbonitrile (3b) showed the most potent antibacterial activity against Escherichia coli and Pseudomonas aeruginosa. Several chromeno[2,3‐b]pyridine derivatives showed equal or more potency against Staphylococcus aureus and Candida albicans.
Dicyano(7‐methyl‐6‐oxo‐6H‐dibenzo[b,d]pyran‐9‐yl)methanide Salts via a Multicomponent Reaction
Authors: Khoobi Mehdi , Ramazani Ali , Foroumadi Alireza , Souldozi Ali , Ślepokura Katarzyna , Lis Tadeusz , Mahyari Amir , Shafiee Abbas , Joo Sang Woo
Published: May 2013

Dialkylammonium dicyano(7‐methyl‐6‐oxo‐6H‐dibenzo[b,d]pyran‐9‐yl)methanides 4a–4j are obtained in good yields via a simple reaction between 3‐acetylcoumarins (=3‐acetyl‐2H‐1‐benzopyran‐2‐ones) 1 and malononitrile (2) in EtOH (Table 1). In this reaction, a charge‐separated zwitterionic salt is formed.
Stereoconvergent Generation of a Contrasteric syn‐Bicyclopropylidene (=syn‐Cyclopropylidenecyclopropane) by Stille‐Like Coupling
Authors: Güney Murat , Eşsiz Selçuk , Daştan Arif , Balci Metin , De Lucchi Ottorino , Şahin Ertan , Fabris Fabrizio
Published: May 2013

Stereoisomerically pure endo‐ and exo‐7‐halo‐7‐(trimethylstannyl)benzonorcar‐3‐enes (=endo‐ and exo‐(1‐halo‐1a,2,7,7a‐tetrahydro‐1H‐cyclopropa[b]naphthalen‐1‐yl)trimethylstannane) 4 and 6 were selectively obtained by lithiumtin or magnesiumtin transmetalation in good yields (Scheme 2 and 3). The reaction of these compounds with copper(I) thiophene‐2‐carboxylate (CuTC) produced in both cases the corresponding CS‐symmetric bicyclopropylidene (=cyclopropylidenecyclopropane) syn‐1, a single diastereoisomer (Schemes 5 and 6). The structure of syn‐1 was undoubtedly elucidated by X‐ray single crystal diffraction. The coupling mechanism of the carbenoid cyclopropane is discussed (Scheme 7).
Two New Bis‐alkaloids from the Aerial Part of Piper flaviflorum
Authors: Wu Yu , Zheng Cheng‐Jian , Deng Xue‐Hong , Qin Lu‐Ping
Published: May 2013

Two new bis‐alkaloids, flavifloramides A (1) and B (2), as well as two known alkaloids, N‐trans‐feruloyltyramine (3) and paprazine (4), were isolated from the aerial part of Piper flaviflorum. The structures of the new compounds were elucidated by spectroscopic analyses, including 2D‐NMR techniques.
Organic Stereochemistry. Part 5
Authors: Testa Bernard , Vistoli Giulio , Pedretti Alessandro , Caldwell John
Published: May 2013

This review continues a general presentation of the principles of stereochemistry with special reference to the medicinal sciences. Here, we discuss and illustrate molecular and clinical phenomena of stereoselectivity in pharmacological effects, namely activity differences between stereoisomers, principally enantiomers. The review begins with didactic models of chiral recognition, with a main focus on the early model ofEassonandStedman.There follows a Molecular Modeling (MM) and Molecular Dynamics (MD) depiction of the differential interaction of the enantiomers of hyoscyamine with cholinergic muscarinic receptors. The next section is devoted to various rationalizations in stereoselective pharmacological activity,e.g., the influence of optical purity on enantioselectivity,Pfeiffer's rule, and eudismic analysis. The review ends with selected examples taken from various fields of preclinical and clinical pharmacology, of differences between stereoisomers in terms of drug absorption, distribution, and excretion. The influence of conformational factor in molecular pharmacology will be discussed inPart 6, while stereoselective aspects of xenobiotic metabolism will be reviewed inParts 7and8.
Statistical corrections of spatially interpolated missing precipitation data estimates
Authors: Teegavarapu Ramesh S. V.
Published: May 2013

Spatial interpolation methods used for estimation of missing precipitation data generally under and overestimate the high and low extremes, respectively. This is a major limitation that plagues all spatial interpolation methods as observations from different sites are used in local or global variants of these methods for estimation of missing data. This study proposes bias‐correction methods similar to those used in climate change studies for correcting missing precipitation estimates provided by an optimal spatial interpolation method. The methods are applied to post‐interpolation estimates using quantile mapping, a variant of equi‐distant quantile matching and a new optimal single best estimator (SBE) scheme. The SBE is developed using a mixed‐integer nonlinear programming formulation. K‐fold cross validation of estimation and correction methods is carried out using 15 rain gauges in a temperate climatic region of the U.S. Exhaustive evaluation of bias‐corrected estimates is carried out using several statistical, error, performance and skill score measures. The differences among the bias‐correction methods, the effectiveness of the methods and their limitations are examined. The bias‐correction method based on a variant of equi‐distant quantile matching is recommended. Post‐interpolation bias corrections have preserved the site‐specific summary statistics with minor changes in the magnitudes of error and performance measures. The changes were found to be statistically insignificant based on parametric and nonparametric hypothesis tests. The correction methods provided improved skill scores with minimal changes in magnitudes of several extreme precipitation indices. The bias corrections of estimated data also brought site‐specific serial autocorrelations at different lags and transition states (dry‐to‐dry, dry‐to‐wet, wet‐to‐wet and wet‐to‐dry) close to those from the observed series. Bias corrections of missing data estimates provide better serially complete precipitation time series useful for climate change and variability studies in comparison to uncorrected filled data series. Copyright © 2013 John Wiley & Sons, Ltd.
Assessment of evaporation and water fluxes in a column of dry saline soil subject to different water table levels
Authors: Hernández‐López María Fernanda , Gironás Jorge , Braud Isabelle , Suárez Francisco , Muñoz José Francisco
Published: May 2013

Dry saline soils are common in the arid and hyper‐arid basins located in the Chilean Altiplano, where evaporation from shallow groundwater is typically the major component of the water balance. Thus, a good understanding of evaporation processes is necessary for improving water resource planning and management in these regions. In this study, we conducted laboratory experiments with a natural saline soil column to estimate evaporation rates and assess the liquid and water vapor fluxes under different water table levels. Water content, electrical conductivity and temperature at different depths were utilized to assess the liquid and water vapor fluxes in the soil column. We observed movement of water that dissolves salts from the soil and transports them to areas in the column where they accumulate. Isothermal liquid flux was predominant, while thermal and isothermal liquid and thermal water vapor fluxes were negligible, except for deep water table levels where isothermal and thermal water vapor fluxes had similar magnitude but opposite directions. Differences observed in total fluxes for all water table levels were due to different upward and downward fluxes, which depend on changes in water content and temperature within the soil profile. Both the vapor flux magnitude and direction were found to be very sensitive to the choice of empirical parameters used in flux quantification, such as tortuosity and the enhancement factor for local temperature gradients in the air phase within the column. Copyright © 2013 John Wiley & Sons, Ltd.
Understanding the Molecular Basis of RNA Polymerase II Transcription
Authors: Zhang Su , Wang Dong
Published: May 2013

Synthetic nucleic acid analogues have profoundly advanced our knowledge of DNA and RNA, as well as the complex biological processes that involve nucleic acids. As a pivotal enzyme, eukaryotic RNA polymerase II (Pol II) is responsible for transcribing DNA into messenger RNA, which then serves as a template to direct protein synthesis. Chemically modified nucleic acid analogues have greatly facilitated the structural elucidation of the RNA Pol II elongation complex and our understanding of the key chemical interactions governing RNA Pol II transcriptional fidelity. This review addresses major progress in RNA polymerase II mechanistic studies using modified nucleic acid analogues in recent years.
The Evolution and Practice of Institutional Research
Authors: Taylor John , Hanlon Martin , Yorke Mantz
Published: May 2013

Although institutional research has been a significant feature of U.S. higher education for more than 50 years, it is not so well understood in other parts of the world. As higher education around the world faces increasingly challenging times in responding to pressures of massification and globalization, increasing forms of accountability and competition, new stakeholder expectations, and rapidly changing technologies, IR will inevitably evolve to become a stronger force. The authors discuss available models that describe organizational maturity and propose a comprehensive maturity model for IR.
Preparation of electrospun fiber mats using siloxane‐containing vaterite and biodegradable polymer hybrids for bone regeneration
Authors: Fujikura Kie , Lin Sen , Nakamura Jin , Obata Akiko , Kasuga Toshihiro
Published: May 2013

An electrospun fiber mat using a new composite consisting of siloxane‐containing vaterite (SiV) and poly(lactic‐co‐glycolic acid) (PLGA) (denoted by SiPLGVH) was prepared with the aim of applying it as a membrane for use in a guided bone regeneration (GBR) system. Another electrospun fiber mat using a previously described composite consisting of SiV and poly(L‐lactic acid) (denoted by SiPVH) was also prepared as a comparative sample. SiPLGVH fiber mats showed superior results in terms of mechanical tensile properties and cellular behavior. Their elongation before failure was about eight times higher than that of SiPVH. The numbers of osteoblast‐like cells that proliferated on the SiPLGVH fiber mats, regardless of the hydroxyapatite coating, were comparable to that of SiPVH. The cells spread more, two dimensionally, on the SiPLGVH fiber mats, since the pores between fibers were narrowed down because of swelling of the PLGA matrix during cell culture. This two‐dimensional cellular proliferation quality on the SiPLGVH fiber mats is expected to be suitable for materials used in GBR, leading to control of infiltration of the soft tissue and great tissue integration with the surrounding tissue. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 101B: 1350–1358, 2013.
Multilayer scaffold of electrospun PLA–PCL–collagen nanofibers as a dural substitute
Authors: Wang Yu‐fei , Guo Hong‐feng , Ying Da‐jun
Published: May 2013

Dural closure after the neurosurgery can prevent postoperative complications. Although many types of dural substitute have been developed, most of them lack functional and structural characteristics compared with the natural dura mater. In this study, we used electrospinning method to fabricate a multilayer scaffold to promote dural repair. The inner layer of the scaffold that faces the brain tissue is composed of poly‐lactic acid (PLA) to reduce tissue adhesion. The middle layer of the scaffold is composed of poly‐ɛ‐caprolactone and PLA, which provides a watertight seal. The outer layer of the scaffold contains a large amount of collagen to promote cell attachment and proliferation. The results from in vitro study and an animal model have shown that this multilayer fibrous scaffold has sufficient mechanic strength and biochemical properties to enhance dural repair. Therefore, fabrication of scaffold with multiple functional and structural layers may provide a novel approach for tissue engineering. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 101B: 1359–1366, 2013.
Circulating endothelial cell kinetics and their potential predictive value during mobilization procedure
Authors: Szmigielska‐Kapłon Anna , Krawczyńska Anna , Czemerska Magdalena , Pluta Agnieszka , Cebula‐Obrzut Barbara , Szmigielska Katarzyna , Smolewski Piotr , Robak Tadeusz , Wierzbowska Agnieszka
Published: May 2013

Objective: Circulating endothelial cells (CECs) in patients with hematological malignancies are assessed as a noninvasive marker of angiogenesis. The aim of this study was to evaluate the numbers of CECs and their subsets during mobilization of hematopoietic stem cells. Patients and methods: Thirty‐eight patients were enrolled to the study (19 females and 19 males) at median age of 56.5 years. The group consisted of patients with multiple myeloma (26), lymphoma (10), and acute myeloid leukemia (2). Blood samples were collected before chemotherapy (0), 1 day after chemotherapy (Cht+1), on the day G‐CSF commenced (G0), after 1 day of G‐CSF (G+1), and on the day of the first apheresis. CECs were evaluated by four‐color flow cytometry. Circulating progenitor cells were defined as CD45−/CD34+/CD31+/CD133+. Apoptotic CECs (ApoCECs) were defined as CD146+/AnnexinV+. Results: Median (Me) CECs number was 10.5/µl and it decreased after chemotherapy (Me = 8.3/µl, P < 0.001 when compared with baseline). Based on the number of aphereses needed to obtain 2 × 106/kg CD34+ cells, patients were divided into “highly efficient” (one apheresis) and “poorly efficient” mobilizers (two or more aphereses). Median ApoCEC at Day G+1 was lower in highly efficient than in poorly efficient mobilizers (Me = 3.1/µl vs. Me = 5.1/µl, P = 0.02). ApoCEC at Day G+1 correlated with the number of aphereses (r = 0.48, P = 0.03). In multivariate analysis, ApoCEC at Day G+1 was an independent factor for successful mobilization during one apheresis. Conclusions: CECs and their subsets change significantly during mobilization of HSCs. ApoCECs measured at the time of G‐CSF commencement can predict the efficacy of HSC collection. J. Clin. Apheresis 28:341–348, 2013. © 2013 Wiley Periodicals, Inc.
Embedding Partial k‐Star Designs
Authors: Hoffman D. G. , Roberts Dan
Published: May 2013

A k‐star is the complete bipartite graph . Let G and H be graphs, and let be a partial H‐decomposition of G. A partial H‐decomposition, , of another graph is called an embedding of provided that and G is a subgraph of . We find an embedding of a partial k‐star decomposition of into a k‐star decomposition of , where s is at most if k is odd, and if k is even.
Identification of Daqingye and Banlangen including crude drugs and decoction dregs from three plant species by normal light and fluorescence microscopy
Authors: Xiaojing Wan , Liang Zhitao , Chen Hu-biao , Zhao Zhongzhen , Li Ping
Published: May 2013

Daqingye and Banlangen are commonly used Chinese medicinal materials derived from the leaves and roots of Isatis indigotica Fort., respectively, which clinical effects have been confirmed by many studies in recent years. However, many problems have arisen concerning the quality and identity of materials sold in the market under these two names. Thus, the identification of Daqingye and Banlangen has drawn public attention. In this work, transverse sections of Daqingye and Banlangen from I. indigotica Fort. and two easily confused species, namely Baphicacanthus cusia (Nees) Bremek. and Clerodendrum cyrtophyllum Turcz., were investigated with normal light and fluorescence microscopy. The distinguishing features were 7–9 vascular bundles, cystoliths and nonglandular hairs in the leaves of I. indigotica, B. cusia, and C. cyrtophyllum, respectively. The Banlangen could be distinguished according to the characteristics of parenchymous cells, cystoliths, and stone cells. Moreover, the fluorescence features of Daqingye and Banlangen investigated in this study can provide direct points for differentiating those samples. Importantly, whether the crude drugs were decocted could be easily identified by their different fluorescence features, which can ensure their quality in clinical application. This is the first report to distinguish the three species that are commonly found in the market sold as Daqingye and Banlangen by normal light and fluorescence microscopy. This work indicates that the combination of normal light and fluorescence microscopy could be powerful, convenient, and economical for authenticating Daqingye and Banlangen from the three species, including crude drugs and decoction dregs. Microsc. Res. Tech. 76:774–782, 2013. © 2013 Wiley Periodicals, Inc.
A place for ultrastructural analysis of platelets in cerebral ischemic research
Authors: Van Der Spuy Wendy Jeannette , Pretorius Etheresia
Published: May 2013

It is well known that estrogen is neuroprotective through various mechanisms which suggest that sex hormone levels, thrombotic mechanisms, and inflammatory processes are strongly interconnected in predicting the outcome and consequences of cerebral ischemia. Because platelet ultrastructure is altered in conditions like thrombosis and associated with stroke, the question arises whether ultrastructural analyses of platelet morphology may provide further insight into the role of estrogen during ischemic insult. In the current study, a hyperglycemic modification to the two‐vessel occlusion model for inducing experimental cerebral ischemia was employed, in order to correlate neural tissue integrity levels between three experimental groups to corresponding platelet ultrastructure so as to determine whether there is an association between cerebral ischemia and the presence of inflammatory or necrotic platelet ultrastructure. It is apparent in the results that under the influence of estrogen in cyclic or intact females, there is lesser neural tissue damage as well as a reduced degree of inflammation evident in platelet activation morphology when compared to males and acyclic or ovariectomized females. It is unmistakable that neural injury is closely shadowed, if not preceded, by inflammatory changes in the coagulation system, particularly manifested in platelet ultrastructure. It is therefore suggested that platelets may indeed be used successfully to follow the progression of events of cerebral ischemia and possibly assist in the assessment of treatment strategies and their effects on hemostasis. Microsc. Res. Tech. 76:795–802, 2013. © 2013 Wiley Periodicals, Inc.
Physical and biogeochemical properties in landfast sea ice (Barrow, Alaska): Insights on brine and gas dynamics across seasons
Authors: Zhou Jiayun , Delille Bruno , Eicken Hajo , Vancoppenolle Martin , Brabant Frédéric , Carnat Gauthier , Geilfus Nicolas‐Xavier , Papakyriakou Tim , Heinesch Bernard , Tison Jean‐Louis
Published: May 2013

The impacts of the seasonal evolution of sea‐ice physical properties on ice‐ocean biogeochemical exchanges were investigated in landfast ice at Barrow (Alaska) from January through June 2009. Three stages of brine dynamics across the annual cycle have been identified based on brine salinity, brine volume fraction, and porous medium Rayleigh number (Ra). These are sea‐ice bottom‐layer convection, full‐depth convection, and brine stratification. We further discuss the impact of brine dynamics on biogeochemical compounds in sea ice: stable isotopes of water (δD, δ18O), nutrients (NO3−, PO43−, NH4+), microalgae (chlorophyll‐a), and inert gas (argon). In general, full‐depth convection events favor exchanges between sea ice and seawater, while brine stratification limits these exchanges. However, argon responds differently to brine dynamics than the other biogeochemical compounds analyzed in this study. This contrast is attributed to the impact of bubble nucleation on inert gas transport compared to the other biogeochemical compounds. We present a scenario for argon bubble formation and evolution in sea ice and suggest that a brine volume fraction approaching 7.5–10% is required for inert gas bubbles to escape from sea ice to the atmosphere.
Seasonal variability of light absorption properties and water optical constituents in Hudson Bay, Canada
Authors: Xi Hongyan , Larouche Pierre , Tang Shilin , Michel Christine
Published: May 2013

Previous studies have shown that the properties of optically significant water constituents (phytoplankton, suspended matter, and colored dissolved organic matter (CDOM)) in Hudson Bay are different from other Arctic regions. A new bio‐optical data set collected in summer 2010 shows that this region also presents seasonal variability of the light absorption coefficients by the different constituents, with a higher relative proportion of CDOM absorption in summer than in the fall as a result of decreased phytoplankton absorption in summer. The slope of the exponential function describing nonalgal particles and CDOM spectral absorption shows little variability between fall and summer. Seasonal variability of light absorption coefficients and water optical constituents is more pronounced near the coast, while less variability is observed in the central part of the bay. Very low summertime chlorophyll‐specific absorption coefficients by phytoplankton, among the lowest reported in the literature, are attributed to the high proportion of large size phytoplankton (microphytoplankton) and important packaging effect. There is also a smaller contribution of accessory pigments to total pigments in the summer than in the fall, resulting in a lower blue‐to‐red phytoplankton absorption ratio. These results emphasize that it is necessary to take into account the seasonal variability of light absorption properties in bio‐optical models for further remote sensing applications in Hudson Bay.
The lightning activity associated with the dry and moist convections in the Himalayan Regions
Authors: Penki R. K. , Kamra A. K.
Published: May 2013

Lightning activity in the dry environment of northwest India and Pakistan (NW) and in the moist environment of northeast India (NE) has been examined from the Optical Transient Detector and Lightning Imaging Sensor data obtained from the Tropical Rainfall Measuring Mission satellite during 1995–2010. In the NW region, seasonal variation of flash rate is annual with a maximum in July but is semi‐annual with a primary maximum in April and a secondary maximum in September, in the NE region. On diurnal scale, flash rate is the maximum in the afternoons, in both the NE and NW regions. The correlation of flash rate with convective parameters, viz. surface temperature, convective available potential energy (CAPE) and outgoing long‐wave radiation is better with convective activity in the NW than in the NE region. Mean value of aerosol optical depth at 550 nm is ~ 26% higher and is highly correlated with flash rate in NW as compared to that in NE. Results indicate that CAPE is ~ 120 times more efficient in NW than in the NE region for production of lightning. The empirical orthogonal function analysis of flash rate, surface temperature, and CAPE shows that variance of lightning activity in these regions cannot be fully explained by the variance in the surface temperature and CAPE alone, and that some other factors, such as orographic lifting, precipitation, topography, etc., may also contribute to this variance in these mountainous regions. Further, the increase in CAPE due to orographic lifting in the Himalayan foothills in the NE region may contribute to ~ 7.5% increase in lightning activity. Relative roles of the thermally induced and moisture‐induced changes in CAPE are examined in these regions. This study merely raises the questions, and that additional research is required for explaining the fundamental reasons for the reported observations here.
The Average Degree of Minimally Contraction‐Critically 5‐Connected Graphs
Authors: Ando Kiyoshi , Egawa Yoshimi , Kriesell Matthias
Published: May 2013

An edge of a 5‐connected graph is said to be 5‐removable (resp. 5‐contractible) if the removal (resp. the contraction) of the edge results in a 5‐connected graph. A 5‐connected graph with neither 5‐removable edges nor 5‐contractible edges is said to be minimally contraction‐critically 5‐connected. We show the average degree of every minimally contraction‐critically 5‐connected graph is less than . This bound is sharp in the sense that for any positive real number ε, there is a minimally contraction‐critically 5‐connected graph whose average degree is greater than .
Genetic and functional diversity of fluorescent Pseudomonas from rhizospheric soils of wheat crop
Authors: Yadav Subhash , Yadav Shivani , Kaushik Rajeev , Saxena Anil K. , Arora Dilip K.
Published: May 2013

Wheat rhizospheric soils were collected from different part of northern and eastern Indo‐Gangetic plains, which is being irrigated from water of Ganga River. Isolation of fluorescent Pseudomonas species was carried out from the soil samples collected. The percentage of isolates positive for indolic compound, P‐solubilisation, siderophore production and ACC deaminase activity were 64.0, 38.6, 63.5, and 19.7, respectively. A total of 543 isolates were randomly selected for studies based on the genus specific confirmation by the Pseudomonas specific primer. Among the 543 isolates, 26 different clusters were formed from 16S rDNA‐RFLP whereas 27 clusters were generated by the rpoB‐RFLP with similarity percent ranging from 3 to 100%. 16S rDNA sequencing showed 9 different species of Pseudomonas whereas, rpoB sequencing showed 13 different species of Pseudomonas. Phylogenetic analysis based on 16S rDNA gene sequences generated 15 branches showing the more than 70% of boot strap value, whereas 18 branches in the rpoB based phylogenetic tree were supported by bootstrap values above 70%. Diversity indices based on rpoB were higher than the ribosomal RNA gene.