bluuebunny/crossref_metadata_2025_split huggingface dataset:
Natural (−)‐Vasicine as a Novel Source of Optically Pure 1‐Benzylpyrrolidin‐3‐ol
Authors: Aga Mushtaq A. , Kumar Brijesh , Rouf Abdul , Shah Bhahwal A. , Andotra Samar S. , Taneja Subhash C. 
Published: May 2013

AbstractA facile and scalable methodology for the preparation of optically active (3S)‐1‐benzylpyrrolidin‐3‐ol (3), an important drug precursor, is reported. Starting from the naturally occurring alkaloid (−)‐vasicine (1), a major alkaloid of the plant Adhatoda vasica, 3 was obtained in 84% overall yield (Scheme 3).
Thermoresponsive biodegradable PEG‐PCL‐PEG based injectable hydrogel for pulsatile insulin delivery
Authors: Payyappilly Sanal , Dhara Santanu , Chattopadhyay Santanu 
Published: May 2013

AbstractAn injectable biodegradable hydrogel was prepared for temperature‐responsive pulsatile release of insulin. Triblock copolymer of poly(ethylene glycol)‐poly(ε‐caprolactone)‐poly(ethylene glycol) (PEG‐PCL‐PEG, PECE) was prepared by ring opening bulk copolymerization and characterized using FT‐IR, 1HNMR, and gel permeation chromatography. Aqueous solution of PECE formed an injectable hydrogel, which was solution at room temperature and transformed into gel at 37°C. The temperature‐responsive sol–gel transition and crystallinity of PECE hydrogel was studied and compared with pluronic, a well‐studied nonbiodegradable injectable hydrogel. In vitro release study revealed that insulin release profile of PECE was similar to pluronic, and its viscosity was 1/30th of pluronic sol at 10,000 s−1 shear rate. Release behavior of insulin from PECE hydrogels followed Fickian diffusion of first order. Insulin retained its secondary structure after release as confirmed by circular dichroism spectrum. A threefold increase in Fickian diffusion coefficient was evidenced when temperature was increased from 34 to 40°C because of crystalline melting of PCL part of PECE. Pulsatile release of insulin showed a correlation coefficient of 0.90 with the change of temperature. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1500–1509, 2014.
Improved neural progenitor cell proliferation and differentiation on poly(lactide‐co‐glycolide) scaffolds coated with elastin‐like polypeptide
Authors: Choi Seong‐Kyoon , Park Jin‐Kyu , Lee Kyeong‐Min , Lee Soo‐Keun , Jeon Won Bae 
Published: May 2013

AbstractPoly(lactide‐co‐glycolide) (PLGA) and elastin‐like polypeptide (ELP) have been widely used as a biodegradable scaffold and thermoresponsive matrix, respectively. However, little attention has focused on the combinatorial use of these biomaterials for tissue engineering applications. An ELP matrix TGPG[VGRGD(VGVPG)6]20WPC (referred to as REP) contains multiple Arg‐Gly‐Asp motifs. This study fabricated porous PLGA scaffolds coated with various concentration of matrix via thermally induced phase transition to improve adhesion‐mediated proliferation and differentiation of neural progenitor cells. Matrix‐coated scaffolds were characterized by FTIR, SEM, and hematoxylin and eosin staining with respect to coating efficiency, porosity, and pore size and shape. On the matrix‐coated scaffolds, cells grew as a single cell or associated each other to form a multicellular layer or cluster. In biological evaluations, cell adhesion and proliferation were significantly promoted in a matrix concentration‐dependent manner. More importantly, in combination with retinoic acid, the differentiation of progenitor cells into neuronal and astroglial lineages was highly stimulated in the cells cultured on matrix‐coated scaffolds than on untreated controls. Taken together, our results indicated that the REP matrix‐functionalized PLGA scaffolds are suitable for improving neuronal cell functions, and thus applicable for neural tissue engineering. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 101B: 1329–1339, 2013.
Orbital wall repair in canines with beta‐tricalcium phosphate and induced bone marrow stromal cells
Authors: Zhou Huifang , Deng Yuan , Bi Xiaoping , Xiao Caiwen , Wang Yefei , Sun Jing , Gu Ping , Fan Xianqun 
Published: May 2013

AbstractBone tissue engineering is a new approach for the repair of orbital defects. The aim of the present study was to evaluate prefabricated beta‐tricalcium phosphate (β‐TCP) combined with autologous bone marrow stromal cells (BMSCs) to repair orbital wall defect in canine models. Defects measuring 10 mm in diameter were created in the orbital medial walls of 12 dogs. The orbits were randomly divided into five groups: group 1, repaired with osteogenesis‐induced BMSCs/TCP constructs; group 2, repaired with noninduced BMSCs/TCP constructs; group 3, repaired with β‐TCP scaffolds only; group 4, normal group; group 5, negative control (bone defect without treatment). Computed tomography (CT) scanning, gross observation, bone density measurements, micro–CT, and histological observations were performed. In group 1, new bone was observed with only a small amount of residual material, and bony union was achieved 3 months after surgery. In contrast, the constructs showed slow degradation with minimal bone formation in groups 2 and 3. Furthermore, the appearance and bone density of the constructs in group 1 were similar to that of normal bone: the constructs were covered with complete mucosa, and new alveolate plate grew into the ethmoidal sinuses. A large bone defect remained in group 5. This study demonstrated that biologic scaffolds composed of β‐TCP and osteogenesis‐induced BMSCs have been successfully used to restore bone functionality in animal models, which may provide a potential clinical approach for orbital wall repair and bone regeneration in humans. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 101B: 1340–1349, 2013.
A novel bidirectional continuous perfusion bioreactor for the culture of large‐sized bone tissue‐engineered constructs
Authors: Gardel Leandro S. , Correia‐Gomes Carla , Serra Luís A. , Gomes Manuela E. , Reis Rui L. 
Published: May 2013

AbstractThis works reports the development and preliminary assessment of a new bioreactor for culturing large‐sized three‐dimensional constructs in bone tissue engineering. The bidirectional continuous perfusion bioreactor (BCPB) promotes mechanical stimulation of cells through the creation of shear forces induced by flow perfusion. The main innovation consists in the possibility of culturing scaffolds of large dimensions that can be suitable for the regeneration of critical sized defects. The functionality of BCPB was preliminarily evaluated by culturing starch–polycaprolactone scaffolds/goat bone marrow stromal cells for 14 and 21 days. Cylindrical blocks were stacked (42 mm thick). Static culture was used as controls. The samples were collected for DNA, alkaline phosphatase (ALP), scanning electron microscopy (SEM), and histological analysis. The results showed higher ALP levels in the bioreactor cultures than those obtained under static conditions. The number of cells in constructs cultured in the bioreactor showed lower values compared to static cultures, suggesting that static conditions tend to privilege the metabolic path way for cellular proliferation while dynamic conditions tend to privilege the metabolic path for osteogenic differentiation. SEM observations show that, the migration and cell distribution was observed in the bioreactor. These results demonstrate the feasibility and the benefit of culturing constructs in BCPB. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 101B: 1377–1386, 2013.
Electrochemical Behavior and Determination of Phenylephrine at Silicate Nanotubes Modified Electrode
Authors: Qu Song , Pei Supeng , Zhang Shuping 
Published: May 2013

AbstractA novel Silicate nanotubes (SNTs) modified glass carbon (GC) electrode was prepared and used to study the electrochemcial behavior of phenylephrine (PHE) and determine it. The enhanced electrochemical response of PHE at SNTs modified electrode was observed as compared with bare GC electrode. This proposed method displayed a broad linear range and a lower detection limit for PHE. The linear range was from 8 × 10−8 M to 2 × 10−5 M with the detection limit of 1 × 10−8 M. The electrode could be easily regenerated and exhibited high stability and good selectivity. This method was successfully applied to the determination of PHE in drug samples with satisfactory result. The strategy presented here opens a new way for the development of nanoelectronic devices or electrochemical sensors based on SNTs.
Convenient Synthesis of 14‐Aryl‐14‐H‐dibenzo[a,j]xanthenes Catalyzed by Acyclic Brønsted Acidic Ionic Liquid [H—NMP]+[HSO4]− under Microwave Irradiation
Authors: Naeimi Hossein , Nazifi Zahra Sadat 
Published: May 2013

AbstractEfficient method for direct preparation of 14‐aryl‐14‐H‐dibenzo[a,j]xanthenes through condensation of β‐naphthol with various aromatic aldehydes in the presence of the catalytic amount of [H—NMP]+[HSO4]− under microwave irradiation was described. This method has the advantages such as; very easy reaction workup, absolute separation of catalyst from the reaction mixture and smooth recyclability of catalyst. In this reaction 14‐aryl‐14‐H‐dibenzo[a,j]xanthenes were obtained as desired products in excellent yields and short reaction times via green and one‐pot procedure.
Observed effects of solar proton events and sudden stratospheric warmings on odd nitrogen and ozone in the polar middle atmosphere
Authors: Päivärinta S.‐M. , Seppälä A. , Andersson M. E. , Verronen P. T. , Thölix L. , Kyrölä E. 
Published: May 2013

AbstractHere we use satellite observations from the ACE‐FTS, MLS/Aura and SABER/TIMED to study the effects of solar proton events (SPEs) and strong sudden stratospheric warmings (SSWs) on the middle atmospheric odd nitrogen (NOx) and ozone levels in the Northern Hemispheric polar region. Three winters (January–March) are considered: (1) 2005 (SPE), (2) 2009 (SSW), and (3) 2012 (SPEs and SSW). These different cases provide a good opportunity to study the roles that transport from the mesosphere‐lower thermosphere region and in situ production due to particle precipitation have on stratospheric NOx levels and the consequent effects on the middle atmospheric ozone. The observations show increases in NOx after both the SPEs (days to weeks) and SSWs (weeks to months) by up to a factor of 25 between 40 and 90 km. The largest mesospheric NOx increases are observed following the SSW in late January 2009, but the most substantial effects in the upper stratosphere are seen when both an SSW and in situ production by SPEs take place (2012), even though the in situ NOx production in 2012 was relatively weak in magnitude compared to periods of much higher solar activity. In 2012, both short‐term (days, due to SPEs and odd hydrogen) depletion and longer‐term (months, due to several drivers) depletion of ozone of up to 90% are observed in the mesosphere and upper stratosphere, coinciding with the enhanced amounts of NOx.
Probing into the impact of 3DVAR assimilation of surface PM10 observations over China using process analysis
Authors: Jiang Ziqiang , Liu Zhiquan , Wang Tijian , Schwartz Craig S. , Lin Hui‐Chuan , Jiang Fei 
Published: May 2013

AbstractThe capability of assimilating surface PM10 (particulate matter with diameters less than 10 µm) observations has been developed within the National Centers for Environmental Prediction Gridpoint Statistical Interpolation three‐dimensional variational (3DVAR) data assimilation (DA) system. It provides aerosol analyses for the Goddard Chemistry Aerosol Radiation and Transport aerosol scheme within the Weather Research and Forecasting/Chemistry model. Control and assimilation experiments were performed for June 2011 over China to explore in detail the impact of assimilating surface PM10. In the assimilation experiment, analyses were produced every 6 h to adjust the mass concentrations of different aerosol species. The statistical results from two parallel experiments demonstrate that the assimilation of surface PM10 observations can significantly reduce the uncertainty of initial aerosol fields and effectively improve the subsequent aerosol forecasts for at least 12 h. However, the benefit from the assimilation of PM10 diminishes rapidly with forecast range. Process analysis for PM10 formation indicates that the rapidly diminishing DA impact on aerosol forecasts, especially in early forecast hours, was dominated by vertical mixing with an additional contribution from advection. Both processes were mainly related to unbalanced aerosol fields in the horizontal and vertical after assimilating surface observations. These findings illustrate the importance of adjusting aerosol emission rates and the initial aerosol vertical profile.
Quantification of the glucosamine content in the filamentous fungus Monascus ruber cultured on solid surfaces
Authors: Chysirichote Teerin , Reiji Takahashi , Asami Kazuhiro , Ohtaguchi Kazuhisa 
Published: May 2013

AbstractWe evaluated whether the glucosamine content in the filamentous fungus Monascus ruber NBRC 32318, cultured on a solid surface (agar) containing different carbon and nitrogen sources, could be used as a measure of biomass. The relationship between the amounts of glucosamine and biomass was independent of the cultivation period, but was dependent on the carbon source (D‐glucose, D‐fructose, maltose, sucrose, or rice starch) and the nitrogen source (ammonium chloride, sodium nitrate, monosodium glutamate, or yeast extract) in the agar; it was also dependent on the culture method (solid‐surface culture or submerged culture). We concluded that the amount of glucosamine extracted from M. ruber is a useful index for the fungal biomass when the relationship between M. ruber biomass and glucosamine content has previously been calibrated for the carbon and nitrogen sources used. Examination of microphotographs of M. ruber hyphae in conjunction with quantification of the glucosamine and biomass contents indicated that the variation in the glucosamine content per unit biomass affects the hyphal morphology of the fungus, and especially the hyphal diameter.
Cultivable actinomycetes from rhizosphere of birch (Betula pendula) growing on a coal mine dump in Silets, Ukraine
Authors: Ostash Bohdan , Gren Tetiana , Hrubskyy Yaroslav , Tistechok Stepan , Beshley Stepan , Baranov Volodymyr , Fedorenko Victor 
Published: May 2013

AbstractFive actinomycete strains were isolated from the rhizosphere of birch, one of a few native tree forms capable of thriving on the upper level of a coal mine dump near the village of Silets (Lvivska region, Ukraine). No such strains were isolated from surrounding gangue, or from nearby grass Calamagrostis epigeios. Using 16S rDNA sequencing and analysis of cell wall aminoacids, four of these strains were shown to belong to genus Streptomyces and one to be Amycolatopsis. The isolates were able to produce siderophores and antibacterial compounds. In comparison to the reference strain Streptomyces coelicolor M145, certain rhizospheric isolates displayed somewhat increased survival in the presence of copper, iron(III), or chromium(VI) salts. The Amycolatopsis isolate was also shown to accumulate significant quantities of heavy metals from waste extracts. Possible roles of the described strains in coal mine dump ecology are discussed.
Fog and low stratus over the Swiss Plateau − a climatological study
Authors: Scherrer Simon C. , Appenzeller Christof 
Published: May 2013

ABSTRACTThe occurrence of fog and low stratus (FLS) clouds is a common phenomenon over the Swiss plateau during the winter half years. Classical fog observations using horizontal visibility are of limited use for climatological analyses of persistent FLS situations. We present a simple method for determining long climatological series of days with FLS lasting at least a half or a full daylight day. The method relies solely on high quality relative sunshine duration measurements at two stations, a Plateau station below or within the FLS layer (e.g. Zürich/Fluntern) and a nearby peak station above the FLS layer (e.g. Säntis). The analysis for the period 1901–2012 shows that full day FLS are a typical phenomenon of the months November to January, whereas the half day FLS also often occur in October and February. There is substantial interannual and decadal variability. The total number of Zürich full FLS days varies between 4 and 31 d (mean: 17 d) and between 10 and 49 d (mean: 28 d) for at least a half FLS days in the September to March period. The foggiest decade in the 1901–2012 record was 1984–1993; the least foggy decade was 1999–2008 with roughly 40–45% less FLS occurrence than only 15 years before. In the most recent years a return towards the climatological mean can be observed. The long term data series does not show any significant long‐term trends for the occurrence of full nor for half day FLS events. The reconstructed FLS occurrence is well correlated with the number of days with cold air pooling. They show very similar decadal variability and long term trends. © 2013 Royal Meteorological Society
Assessing scale effects for statistically downscaling precipitation with GPCC model
Authors: Chen Jie , Zhang Xunchang J. , Brissette François P. 
Published: May 2013

AbstractThe resolution of general circulation models (GCMs) is too coarse to assess the site‐specific impacts of climate change. Downscaling approaches have been developed to meet this requirement. As the resolution of climate model increases, it is imperative to know whether the finer resolution of regional climate models (RCMs) would result in any improvement of statistical downscaling quality at the station scale for particular downscaling methods. The objective of this study is to assess the effects of climate model resolutions on statistical downscaling quality of precipitation using the generator for point climate change (GPCC) model. The downscaling is conducted across three scales, from GCM, and mid‐ and high‐resolution RCMs to a station scale for two Canadian stations in the Quebec province. Observed precipitation gridded to the corresponding scales is also studied in parallel, totalling six downscaling experiments. The results show that the statistics of downscaled precipitation are somewhat overestimated for the Sept‐Iles station for all six downscaling experiments with the relative error of mean daily, monthly, and annual precipitation ranging between 1.1 and 5.0%, between 2.7 and 5.9% and between 0.5 and 6.2%, respectively, but underestimated for the Bonnard station with the relative error ranging between −4.1 and −10.2%, between −3.2 and −13.3%, and between −2.6 and −12.0%, respectively. The number of wet days per year is well preserved with the difference between observed and downscaled data ranging between −2.9 and 6 d across all downscaling experiments and two stations. The quality of downscaled precipitation is similar between using gridded observations and model‐simulated data for both stations. Furthermore, there is no noteworthy scale effect on downscaling quality when downscaling climate model output with GPCC, indicating that for regions without RCM projections, high‐quality daily series at stations can be derived directly from GCM projections with this particular downscaling model. © 2013 Royal Meteorological Society
Characterization of the spatial and temporal expression of the OsSSII‐3 gene encoding a key soluble starch synthase in rice
Authors: Li Qian‐Feng , Sun Samuel S‐M , Liu Qiao‐Quan 
Published: May 2013

AbstractBackgroundStarch, the major component of rice grain, consists of amylose and amylopectin. SSIIa, a key soluble starch synthase involved in the biosynthesis of rice amylopectin, is a major factor that controls the gelatinization temperature of rice grain. Extensive work has been done and impressive progress has been made in elaborating the function of the gene encoding SSIIa (OsSSII‐3). However, the systematic expression analysis of OsSSII‐3 is still rare.ResultsIn the present study, we performed a comprehensive expression analysis of OsSSII‐3 in both the developing seeds and other tissues of indica rice 9311 by using quantitative real‐time PCR. The results showed that the gene was dominantly expressed in the developing seeds. In addition, the promoter sequence of OsSSII‐3 was cloned and fused with the GUS reporter gene and its expression was carefully monitored in the transgenic rice. The data from both histochemical and fluorometric analyses showed that the OsSSII‐3 promoter was capable of driving the target gene to have an endosperm‐specific expression, which may be due to the existing of several endosperm‐specific motifs in the promoter, including the −300 elements, AACA motifs and GCN4 motifs. This result was quite consistent with that of the endogenous transcription analysis of OsSSII‐3.ConclusionThis study not only advanced our understanding of the spatial and temporal expression characteristics of OsSSII‐3, but also provided a valuable promoter for future application in generating elite rice varieties with high nutritional or medicinal value. © 2013 Society of Chemical Industry
Synthesis and Characterization of End‐Functionalized Poly(3‐butylthiophene) with Semifluoroalkyl Chains
Authors: Ma Jusha , Geng Yanfang , Hashimoto Kazuhito , Tajima Keisuke 
Published: May 2013

AbstractA new poly(3‐butylthiophene) derivative with one terminus functionalized with a 1H,1H,2H,2H,3H,3H‐perfluoroundecyl group (P3BT‐F17) is synthesized by Ni‐catalyzed quasi‐living polymerization and the subsequent quenching of living ends by allyl‐Grignard reagent and the attachment of a fluoroalkyl chain. The quantitative introduction of fluoroalkyl chain ends is confirmed by matrix‐assisted laser desorption/ionization time‐of‐flight–mass spectrometry (MALDI‐TOF‐MS), gel‐permeation chromatography (GPC), 1H NMR spectroscopy, and X‐ray photoelectron spectroscopy (XPS). The electronic properties of P3BT‐F17 in solution and its crystalline structure in the solid state are investigated by UV–vis spectroscopy and cyclic voltammetry (CV), and by DSC and X‐ray diffraction (XRD) analyses.magnified image
Water Plasticizes Only a Small Part of the Amorphous Phase in Nylon‐6
Authors: Reuvers Nicolaas , Huinink Hendrik , Adan Olaf 
Published: May 2013

AbstractIt is known that Polyamide 6 absorbs water in its amorphous phase. The exact composition of the amorphous phase will determine the uptake process. The heterogeneity in the amorphous phase with respect to plasticization by water uptake is quantified in this paper using NMR relaxometry. It is shown that water occupies and plasticizes only a small part (∼6%) of the nylon matrix. This part is located in between the crystalline domains where polymer chain mobility is higher. At low moisture content (<4%) water molecules are tightly bound to the polymer and have the same dynamics. A highly mobile pool of guest‐hydrogen nuclei is detected starting at a moisture content of 4%. Here, water is absorbed in clusters and the interaction between the polymer chains and water molecules decreases, leading to decoupling of the dynamics of water and polymer.magnified image