bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enantioselectivity of Candida rugosa lipases (Lip1, Lip3, and Lip4) towards 2‐bromo phenylacetic acid octyl esters controlled by a single amino acid
Authors: Piamtongkam Rungtiwa , Duquesne Sophie , Bordes Florence , Barbe Sophie , André Isabelle , Marty Alain , Chulalaksananukul Warawut 
Published: March 2011

AbstractEnantiomer discrimination by enzymes is a very accurate mechanism, which often involves few amino acids located at the active site. Lipase isoforms from Candida rugosa are very good enzymatic models to study this phenomenon as they display high sequence homology (>80%) and their enantioselectivity is often pointed out. In the present work, we investigated three lipases from C. rugosa (Lip1, Lip3, and Lip4, respectively) towards the resolution of 2‐bromo‐arylacetic acid esters, an important class of chemical intermediates in the pharmaceutical industry. All exhibited a high enantioselectivity, with Lip4 preferring the R‐enantiomer (E‐value = 15), while Lip1 and Lip3 showed an S‐enantioselectivity >200. A combination of sequence and structure analysis of the three C. rugosa lipases suggested that position 296 could play a role in S‐ or R‐enantiomer preference of C. rugosa lipases. This led to the construction by site‐directed mutagenesis of Lip1 and Lip4 variants in which position 296 was, respectively, exchanged by a Gly, Ala, Leu, or Phe amino acid. Screening of these variants for their enantioselectivity toward 2‐bromo phenyl acetic acid octyl esters revealed that steric hindrance of the amino acid residue introduced at position 296 controls both the enantiopreference and the enantioselectivity value of the lipase: bulkier is the amino acid at position 296, larger is the selectivity towards the S‐enantiomer. To investigate further these observations at an atomic level, we carried out a preliminary modeling study of the tetrahedral intermediates formed by Lip1 and Lip4 with the (R, S)‐2‐bromo‐phenylacetic acid octyl ester enantiomers that provides some insight regarding the determinants responsible for lipase enantiodiscrimination. Biotechnol. Bioeng. 2011; 108:1749–1756. © 2011 Wiley Periodicals, Inc.
Self‐assembled dextrin nanogel as protein carrier: Controlled release and biological activity of IL‐10
Authors: Carvalho Vera , Castanheira Pedro , Madureira Pedro , Ferreira Sílvia A. , Costa Carla , Teixeira João P. , Faro Carlos , Vilanova Manuel , Gama Miguel 
Published: March 2011

AbstractInterleukin‐10 (IL‐10) is an anti‐inflammatory cytokine, which active form is a non‐covalent homodimer. Given the potential of IL‐10 for application in various medical conditions, it is essential to develop systems for its effective delivery. In previous work, it has been shown that a dextrin nanogel effectively incorporated and stabilized rIL‐10, enabling its release over time. In this work, the delivery system based on dextrin nanogels was further analyzed. The biocompatibility of the nanogel was comprehensively analyzed, through cytotoxicity (lactate dehydrogenase (LDH) release, MTS, Live, and Dead) and genotoxicity (comet) assays. The release profile of rIL‐10 and its biological activity were evaluated in vivo, using C57BL/6 mice. Although able to maintain a stable concentration of IL‐10 for at least 4 h in mice serum, the amount of protein released was rather low. Despite this, the amount of rIL‐10 released from the complex was biologically active inhibiting TNF‐α production, in vivo, by LPS‐challenged mice. In spite of the significant stabilization achieved using the nanogel, rIL‐10 still denatures rather quickly. An additional effort is thus necessary to develop an effective delivery system for this cytokine, able to release active protein over longer periods of time. Nevertheless, the good biocompatibility, the protein stabilization effect and the ability to perform as a carrier with controlled release suggest that self‐assembled dextrin nanogels may be useful protein delivery systems. Biotechnol. Bioeng. 2011; 108:1977–1986. © 2011 Wiley Periodicals, Inc.
Cell to aperture interaction in patch‐clamp chips visualized by fluorescence microscopy and focused‐ion beam sections
Authors: Py Christophe , Salim Danish , Monette Robert , Comas Tanya , Fraser Jeffrey , Martinez Dolores , Martina Marzia , Mealing Geoffrey 
Published: March 2011

AbstractPatch‐clamp is an important method to monitor the electrophysiological activity of cells and the role of pharmacological compounds on specific ion channel proteins. In recent years, planar patch‐clamp chips have been developed as a higher throughput approach to the established glass‐pipette method. However, proper conditions to optimize the high resistance cell‐to‐probe seals required to measure the small currents resulting from ion channel activity are still the subject of conjecture. Here, we report on the design of multiple‐aperture (sieve) chips to rapidly facilitate assessment of cell‐to‐aperture interactions in statistically significant numbers. We propose a method to pre‐screen the quality of seals based on a dye loading protocol through apertures in the chip and subsequent evaluation with fluorescence confocal microscopy. We also show the first scanning electron micrograph of a focused ion beam section of a cell in a patch‐clamp chip aperture. Biotechnol. Bioeng. 2011; 108:1936–1941. © 2011 Wiley Periodicals, Inc.
Synchronous fluorescence spectroscopy as a novel tool to enable PAT applications in bioprocesses
Authors: Teixeira Ana P. , Duarte Tiago M. , Carrondo M.J.T. , Alves Paula M. 
Published: March 2011

AbstractIn this work, synchronous fluorescence spectroscopy (SFS) is evaluated as a new tool for real‐time bioprocess monitoring of animal cell cultures. This technique presents several advantages over the traditional two‐dimensional (2D) fluorometry since it provides data on various fluorescent compounds in a single spectrum, showing improved peak resolution and recording speed. Bioreactor cultures of three monoclonal antibody‐producing CHO cell lines were followed in situ by both 2D and synchronous fluorometry techniques. The time profiles of the main spectral features in each data type present some differences, but principal component analysis indicated both as containing enough information to distinguish the cultures. Partial least squares regression models were then independently developed for viable cell density and antibody levels on the basis of the different fluorescence signals recorded, hiding half of the dataset for subsequent validation purposes. Regardless of the signal used, model predictions fit very well the off‐line measurements; still, the synchronous spectra collected at a wavelength difference of 20 nm allowed comparable and superior performances for cell density and antibody titer, respectively, with validation accuracies higher than 91%. Therefore, SFS compares favorably with the traditional 2D approach, becoming an improved, faster option for real‐time monitoring of cells and product titer over culture time. The readiness in data acquisition facilitates the design of process control strategies meeting the requirements of a PAT application. Biotechnol. Bioeng. 2011; 108:1852–1861. © 2011 Wiley Periodicals, Inc.
Simultaneous determination of N‐benzylpiperazine and 1‐(3‐trifluoromethylphenyl)piperazine in rat plasma by HPLC‐fluorescence detection and its application to monitoring of these drugs
Authors: Wada Mitsuhiro , Yamahara Kozue , Ikeda Rie , Kikura‐Hanajiri Ruri , Kuroda Naotaka , Nakashima Kenichiro 
Published: March 2011

ABSTRACTAn HPLC‐fluorescence detection method for simultaneous determination of N‐benzylpiperazine (BZP) and 1‐(3‐trifluoromethylphenyl)piperazine (TFMPP) labeled with 4‐(4,5‐diphenyl‐1 H‐imidazol‐2‐yl)benzoyl chloride (DIB‐Cl) was described. DIB‐BZP and ‐TFMPP were well separated within 13 min without interference of peaks from plasma components. The lower detection limits of BZP and TFMPP at a signal‐to‐noise ratio of 3 were 0.9 and 4.6 ng/mL, respectively. Precisions of the proposed method for intra‐ and inter‐day assays were less than 4.8 and 9.1% as %RSD (n = 5). Furthermore, the method could be successfully applied to monitor both compounds in plasma after their sole or co‐administration to rats (each dose, 2 mg/kg). Clearance of TFMPP was significantly different under the conditions (P = 0.047). Copyright © 2011 John Wiley & Sons, Ltd.
Comparison of fluorescence reagents for simultaneous determination of hydroxylated phenylalanine and nitrated tyrosine by high‐performance liquid chromatography with fluorescence detection
Authors: Iwasaki Yusuke , Mochizuki Keisuke , Nakano Yuki , Maruya Natsumi , Goto Masato , Maruyama Yosuke , Ito Rie , Saito Koichi , Nakazawa Hiroyuki 
Published: March 2011

AbstractReactive oxygen species (ROS) and reactive nitrogen species (RNS) are well‐known and important contributors to oxidative and nitrosative stress in several diseases. Hydroxylated phenylalanine and nitrated tyrosine products appear to be particularly susceptible targets of oxidative and nitrosative stress. We compared fluorescence reagents for their potential use in the analysis of hydroxylated phenylalanine and nitrated tyrosine products with a high‐sensitivity and high‐specificity HPLC‐UV‐FL technique. The analytes were extracted from serum via solid‐phase extraction on Waters Oasis MCX cartridges. Chromatographic separation was achieved on an ODS column (Capcell Pak MG II; 150 × 2.0 mm) using a gradient mobile phase consisting of 20 mm sodium phosphate buffer (adjusted to pH 3.0) and acetonitrile. The method quantification limit for 4‐nitrophenylalanine, m‐tyrosine, and 3‐nitrotyrosine was 0.1 μm. The relative standard deviation of the precision and accuracy was acceptable at the spiked concentration of 0.1 μm for 4‐nitrophenylalanine, m‐tyrosine and 3‐nitrotyrosine. The method could be used for the in vitro analysis of serum samples. Copyright © 2011 John Wiley & Sons, Ltd.
Net Present Value Analysis of Modular Chemical Production Plants
Authors: Lier S. , Grünewald M. 
Published: March 2011

AbstractModular plants consist of modules that autonomously operate parts of the plant. These modules are technically and organizationally limited areas of the plant that fulfill defined tasks. Starting with these modules, companies can create capacity either by equaling up modules from general structures or by numbering up equipment. Here, the economics of a modular chemical plant are compared with those of a traditional large‐scale plant by investigating the net present value. The modular plant presents a more efficient concept for fast growing products or products with volatile demands. This is because the market impact during operation is more important than the preceding influence of the investment. In those cases, the effects of flexibility surpass the effects of scale.
Numerical simulation of underground coal gasification using the CRIP method
Authors: Seifi Mojtaba , Chen Zhangxin , Abedi Jalal 
Published: March 2011

AbstractA three‐dimensional simulation of the Underground coal gasification (UCG) process is studied in terms of the heat and mass transport phenomena and chemical kinetics in a coal seam during coal combustion by applying the controlled retracting injection point technique. The STARS module of the Computer Modelling Group software is used in this study. The gas species flow rate, cavity shapes, and temperature profile in the coal seam during gasification are investigated. The main motivation behind this study is to provide a simulation methodology by using a comprehensive porous media flow approach to understand the critical aspects of the UCG process.
Hydromagnetic non‐Darcy flow, heat and mass transfer over a stretching sheet in the presence of thermal radiation and Ohmic dissipation
Authors: Shateyi S. , Motsa S. S. 
Published: March 2011

AbstractA numerical analysis has been carried out to study magnetohydrodynamic boundary layer flow, heat and mass transfer characteristics on steady two‐dimensional flow of an electrically conducting fluid over a stretching sheet embedded in a non‐Darcy porous medium in the presence of thermal radiation and viscous dissipation. The governing partial differential equations are convected into a system of nonlinear ordinary differential equations by similarity transformation and are solved numerically by using the Successive linearisation method, together with the Chebyshev pseudo‐spectral collocation method. The effects of various parameters on the velocity, temperature, and concentration fields as well as on the skin‐friction coefficient are presented graphically and in tabular forms.
Subunit interactions within the Chlamydomonas flagellar spokehead
Authors: Kohno Takahiro , Wakabayashi Ken‐ichi , Diener Dennis R. , Rosenbaum Joel L. , Kamiya Ritsu 
Published: March 2011

AbstractThe radial spoke (RS)/central pair (CP) system in cilia and flagella plays an essential role in the regulation of force generation by dynein, the motor protein that drives cilia/flagella movements. Mechanical and mechanochemicl interactions between the CP and the distal part of the RS, the spokehead, should be crucial for this control; however, the details of interaction are totally unknown. As an initial step toward an understanding of the RS‐CP interaction, we examined the protein–protein interactions between the five spokehead proteins (radial spoke protein (RSP)1, RSP4, RSP6, RSP9, and RSP10) and three spoke stalk proteins (RSP2, RSP5, and RSP23), all expressed as recombinant proteins. Three of them were shown to have physiological activities by electroporation‐mediated protein delivery into mutants deficient in the respective proteins. Glutathione S‐transferase pulldown assays in vitro detected interactions in 10 out of 64 pairs of recombinants. In addition, chemical crosslinking of axonemes using five reagents detected seven kinds of interactions between the RS subunits in situ. Finally, in the mixture of the recombinant spokehead subunits, RSP1, RSP4, RSP6, and RSP9 formed a 7–10S complex as detected by sucrose density gradient centrifugation. It may represent a partial assembly of the spokehead. From these results, we propose a model of interactions taking place between the spokehead subunits. © 2011 Wiley‐Liss, Inc.
TLR2 signaling improves immunoregulation to prevent type 1 diabetes
Authors: Filippi Christophe M. , Ehrhardt Katrin , Estes Elizabeth A. , Larsson Par , Oldham Janine E. , von Herrath Matthias G. 
Published: March 2011

AbstractSignaling through TLR2 promotes inflammation and modulates CD4+CD25+ Tregs. We assessed mechanistically how this molecule would alter immunoregulation in type 1 diabetes (T1D). We also asked whether TLR2 may be involved in our recent discovery that viral infection can protect from autoimmune diabetes by expanding and invigorating Tregs. Treatment of prediabetic mice with a synthetic TLR2 agonist diminished T1D and increased the number and function of CD4+CD25+ Tregs, also conferring DCs with tolerogenic properties. TLR2 ligation also promoted the expansion of Tregs upon culture with DCs and ameliorated their capacity to prevent the disease. Protection from T1D by lymphocytic choriomeningitis virus (LCMV) infection depended on TLR2. LCMV increased the frequency of CD4+CD25+ Tregs and their production of TGF‐β more significantly in WT than TLR2‐deficient mice. Furthermore, LCMV infection in vivo or LCMV‐infected DCs in vitro rendered, via TLR2, CD4+CD25+ Tregs capable of diminishing T1D. We identify novel mechanisms by which TLR2 promotes immunoregulation and controls autoimmune diabetes in naïve or infected hosts. This work should help understand T1D etiology and develop novel immune‐based therapeutic interventions.
Carborane‐Derivatized Low‐Melting Salts with Ether‐Functionalized Cations – Preparation and Properties
Authors: Liu Shimin , Chen Zhengjian , Zhang Qinghua , Zhang Shiguo , Li Zuopeng , Shi Feng , Ma Xiangyuan , Deng Youquan 
Published: March 2011

AbstractA new series of low‐melting ammonium salts based on the [nido‐7,8‐C2B9H12]– anion have been synthesized and characterized, and their physicochemical properties including spectroscopic properties, thermal properties, surface properties, solubility, density, viscosity, electrochemical properties, and tribological properties have been studied in detail. In comparison with previously reported carborane‐derivatized imidazolium or pyridinium salts, these diether‐functionalized ammonium salts display lower phase transition temperatures (Tg = –76 to –57 °C), and four exist as liquids at room temperature due to their flexible alkoxy chains. TGA analysis revealed that the weight loss rates of these carborane‐derivatized low‐melting salts were ca. 30–80 wt.‐% after thermal decomposition, which is different from the traditional RTILs. SEM images showed that the resulting residue had hollow reticular shell morphology, and XPS and XRD analyses indicate that the main components of the skeleton are B2O3 and amorphous carbon. This provides a new strategy for preparing new inorganic porous materials by thermal decomposition of these low‐melting salts.
Gold Catalysis: Products and Intermediates Obtained from N‐Propargylcarboxamides Bearing Additional Substituents on Nitrogen
Authors: Hashmi A. Stephen K. , Molinari Lise , Rominger Frank , Oeser Thomas 
Published: March 2011

AbstractThe reaction of several propargylamide substrates with additional substituents on the nitrogen atom was investigated. Under aqueous conditions acyloxy‐substituted allylammonium salts could selectively be obtained. Monitoring of the reactions by 1H NMR spectroscopy indicated the presence of an intermediate. Then switching to anhydrous reaction conditions allowed the isolation and characterization of these intermediates, oxazoliniminium species. Workup of the allylammonium salts under basic conditions led to an acyl transfer from the oxygen atom to the nitrogen atom, which proves that these products are not formed by a direct gold‐catalysed hydration of the triple bond only, and at the same time nicely explains the selective monohydration of only one out of two triple bonds.
Determination of fluoroacetate and fluoride in blood serum by capillary zone electrophoresis using capacitively coupled contactless conductivity detection
Authors: Vidal Denis Tadeu Rajh , Augelli Marcio Antonio , Hotta Guilherme Minoru , Lopes Fernando Silva , do Lago Claudimir Lucio 
Published: March 2011

AbstractFluoroacetate is a highly toxic species naturally found in plants and in commercial products (compound 1080) for population control of several undesirable animal species. However, it is non‐selective and toxic to many other animals including humans, and thus its detection is very important for forensic purposes. This paper presents a sensitive and fast method for the determination of fluoroacetate in blood serum using capillary electrophoresis with capacitively coupled contactless conductivity detection. Serum blood samples were treated with ethanol to remove proteins. The samples were analyzed in BGE containing 15 mmol/L histidine and 30 mmol/L gluconic acid (pH 3.85). The calibration curve was linear up to 75 μmol/L (R2=0.9995 for N=12). The detection limit in the blood serum was 0.15 mg/kg, which is smaller than the lethal dose for humans and other animals. Fluoride, a metabolite of the fluoroacetate defluorination, could also be detected for levels greater than 20 μmol/L, when polybrene was used for reversion of the EOF. CTAB and didecyldimethylammonium bromide are not useful for this task because of the severe reduction of the fluoride level. However, no interference was observed for fluoroacetate.
Divide and conquer: the genetic basis of molecular subclassification of breast cancer
Authors: Kristensen Vessela N. 
Published: March 2011

AbstractSince the luminal B tumours are associated with poor recurrence‐free and disease‐specific survivals in all adjuvant systemic treatment categories including hormone therapy, the identification of specific signalling pathways driving luminal B biology is paramount to improve treatment. Sircoulomb et al. and Holland et al. have independently identified the ZNF703 gene, located in chromosomal region 8p12, as preferentially amplified in luminal B tumours.See related articles in EMBO Mol Med (Holland et al. (2011) EMBO Mol Med 3: 167‐180 and Sircoulomb et al. (2011) EMBO Mol Med 3: 153‐166)
What Patients with Anorexia Nervosa Should Wear When They Are Being Weighed: Report of Two Pilot Surveys
Authors: Jaffa Tony , Davies Sarah , Sardesai Anagha 
Published: March 2011

AbstractAimWeighing patients with anorexia nervosa tends to be an integral part of their treatment, yet there is variability in the detail of how this is conducted. The aim of this study was to carry out preliminary exploration of one aspect of this, namely what patients wear when being weighed.MethodTwo Web‐based surveys were conducted accessing the views of ex‐patients (20 respondents) and professionals (98 respondents).ResultsResponses confirmed the variability in arrangements for weighing patients. Both patients and professionals were more concerned with accuracy than with privacy, and the patients stated a preference for being weighed in underwear. Between 30 and 57% of patients reported having falsified their weight during treatment.DiscussionThese surveys provide a reminder of the high frequency of falsification of weight and some support for a policy of weighing in underwear. The strength of the findings is limited by the methodology with small number of ex‐patients all of whom had been through the same treatment programme. Given the paucity of literature on this clinically relevant topic, this does seem to be an area that warrants further investigation. Copyright © 2011 John Wiley & Sons, Ltd and Eating Disorders Association.
Linear combination‐based energy detection algorithm in low signal‐to‐noise ratio for cognitive radios
Authors: Zhang Shibing , Bao Zhihua 
Published: March 2011

AbstractThis paper considers the spectrum sensing technique for cognitive radio‐based on energy detection. It proposes an improved spectrum sensing algorithm by linearly combining the criteria of the probability of detection and the probability of false alarm. Then, the optimal decision threshold is derived for energy detection in the proposed linear combination (LC) algorithm. The performance of primal user detection is significantly improved by using the proposed LC algorithm, especially under low signal‐to‐noise ratios. Simulation results verify the effectiveness of the proposed algorithm with different kinds of primary user signals. Copyright © 2011 John Wiley & Sons, Ltd.