bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of neonatal dexamethasone treatment on hippocampal synaptic function
Authors: Lin Hsiao‐Ju , Huang Chiung‐Chun , Hsu Kuei‐Sen 
Published: May 2006

AbstractObjectiveSynthetic glucocorticoid dexamethasone (DEX) is frequently used as a therapeutic agent to lessen the morbidity of chronic lung disease in premature infants. Surprisingly, little is known about the long‐term neurodevelopmental outcomes of this therapy.MethodsUsing a schedule of tapering doses of DEX similar to that used in premature infants, we examined the consequences of neonatal DEX treatment on hippocampal synaptic plasticity of infants and associative memory later in their lives.ResultsNeonatal DEX treatment changed the direction of synaptic plasticity, favoring low‐frequency, stimulation‐induced, long‐term depression and opposing the induction of long‐term potentiation by high‐frequency stimulation in adolescent (5‐week‐old) rats, but these alterations disappeared in young adult (8‐week‐old) rats. The effects of DEX on long‐term depression and long‐term potentiation were found to correlate with an increase in the autophosphorylation of Ca2+/calmodulin‐dependent protein kinase II and a decrease in the protein phosphatase 1 activity. Neonatal DEX treatment also disrupted memory retention in 5‐week‐old (but not 8‐week‐old) rats subjected to passive avoidance learning tasks.Interpretation:These results suggest that neonatal DEX treatment alters hippocampal synaptic plasticity and contextual fear memory formation in later life, but these impairments apparently are not permanent. Ann Neurol 2006;59:939‐951
B lineage cells in the inflammatory central nervous system environment: Migration, maintenance, local antibody production, and therapeutic modulation
Authors: Meinl Edgar , Krumbholz Markus , Hohlfeld Reinhard 
Published: May 2006

AbstractB cells have long played an enigmatic role in the scenario of multiple sclerosis pathogenesis. This review summarizes recent progress in our understanding of B‐cell trafficking, survival, and differentiation in the central nervous system (CNS). We propose four possible routes of intrathecal immunoglobulin‐producing cells. The inflammatory CNS provides a unique, B‐cell–friendly environment, in which B lineage cells, notably long‐lived plasma cells, can survive for many years, perhaps even for a lifetime. These new findings offer a plausible explanation for the notorious persistence and stability of cerebrospinal fluid oligoclonal bands. Furthermore, we highlight similarities and differences of intrathecal immunoglobulin production in multiple sclerosis patients and patients with other CNS inflammatory conditions. Finally, we outline the possibly double‐edged effects of B cells and immunoglobulin in the CNS and discuss various therapeutic strategies for targeting the B‐cell response. Ann Neurol 2006;59:880‐892
Nanogels prepared by self‐assembly of oppositely charged globular proteins
Authors: Yu Shaoyong , Yao Ping , Jiang Ming , Zhang Guangzhao 
Published: May 2006

AbstractOvalbumin and lysozyme are two main proteins in hen egg white with the isoelectric points of 4.8 and 11, respectively. Herein we report the manufacture of stable, narrowly distributed nanogels (hydrodynamic radius about 100 nm) using a novel and convenient method: ovalbumin and lysozyme solutions were mixed at pH 5.3, the mixture solution was adjusted to pH 10.3, then subsequently stirred and heated. The nanogels were characterized using a combination of techniques. The nanogels have spherical shape and core‐shell structure. The core is mainly composed of lysozyme and the shell is mainly composed of ovalbumin. The proteins in the nanogels are in denatured states and they are bound by intermolecular hydrophobic interactions, hydrogen bonds, and disulfide bonds. The charges of the nanogels can be modulated by the pH of the medium. The electrostatic repulsion of ovalbumin molecules on the nanogel surface stabilizes the nanogels in aqueous solution. The formation mechanism of the nanogels is discussed. © 2006 Wiley Periodicals, Inc. Biopolymers 83: 148–158, 2006This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Engineering Escherichia coli to improve culture performance and reduce formation of by‐products during recombinant protein production under transient intermittent anaerobic conditions
Authors: Lara Alvaro R. , Vazquez‐Limón Consuelo , Gosset Guillermo , Bolívar Francisco , López‐Munguía Agustín , Ramírez Octavio T. 
Published: May 2006

AbstractThree E. coli strains, named VAL22, VAL23, and VAL24, were engineered at the level of mixed‐acid fermentation pathways to improve culture performance under transient anaerobic conditions. VAL22 is a single mutant with an inactivated poxB gene that codes for pyruvate oxidase which converts pyruvate to acetate. VAL23 is a double mutant unable to produce lactate and formate due to deletions of the ldhA and pflB genes that code for lactate dehydrogenase and pyruvate‐formate lyase, respectively. VAL24 is a triple mutant with ldhA and pflB deleted and poxB inactivated. Engineered strains were cultured under oscillating dissolved oxygen tension (DOT) in a scale‐down system, to simulate gradients occurring in large‐scale bioreactors. Kinetic and stoichiometric parameters of constant (10%) and oscillating DOT cultures of the engineered strains were compared with those of the parental strain, W3110. All strains expressed recombinant green fluorescent protein (GFP) as a protein model. Mutant strains showed improved specific growth rate, reduced by‐product formation, and reduced specific glucose uptake rate compared to the parental strain, when cultured under oscillating DOT. In particular, lactate and formate production was abolished and acetate accumulation was reduced by 9–12%s. VAL24 showed the best performance, as specific growth and GFP production rates, and maximum GFP concentration were not affected by DOT gradients and were at least twofold higher than those of W3110 under constant DOT. Under oscillating DOT, VAL24 wasted about 40% less carbon into fermentation by‐products than W3110. It was demonstrated that, although E. coli responds rapidly to DOT fluctuations by deviating to fermentative metabolism, such pathways can be eliminated as they are not necessary for bacterial survival during the short circulation times typical of large‐scale cultures. The approach shown here opens new possibilities for designing metabolically engineered strains, with reduced sensitivity to DOT gradients and improved performance under typical conditions of large‐scale cultures. © 2006 Wiley Periodicals, Inc.
Performance of Nozzle/Diffuser Micro‐Pumps Subject to Parallel and Series Combinations
Authors: Yang K.‐S. , Chen I.‐Y. , Wang C.‐C. 
Published: May 2006

AbstractThis study numerically examines the performance of micro nozzle/diffuser pumps subject to parallel and series combinations. For a single‐chamber micro nozzle/diffuser micro‐pump, four stages are identified. For dual micro‐pumps in a parallel combination, the flow field in each chamber is symmetrical about the center line of the arrangement. For in‐phase operation, the maximum flowrate is about two times higher than that of the single‐chamber. For micro‐pumps in a series combination, it is found that the overall performance is strongly related to the phase angle. The effective flowrate can be significantly increased, decreased, or even reversed. This indicates that the flowrate can be controlled within a wide span by changing the phase angles. At a phase angle of 90°, an eight‐fold increase of effective flowrate is seen relative to that of a single‐chamber operation. The significant increase of flowrate is attributed to two effects; the first effect is due to the “active valve” effect that increases the efficiency during pump mode. The second influence is attributed to the increased pressure difference that brings in more fluid during supply mode.
An Innovative Pulsed Column Applied to Solid‐Liquid Contacting the BPC Column
Authors: Brunet L. , Prat L. , Casamatta G. , Carvin P. 
Published: May 2006

AbstractThe innovative process presented is a novel type of pulsed column (BPC column) used as a solid‐liquid contactor. An evolution in the design of the interior and in the shape of the pulsation has been attained. The initial objectives were to achieve a reactor of greatly increased solid residence time, independent of the liquid phase. Phase contacting is carried out in a column 1.5 m in height. The liquid and solid are flowing countercurrently. The solid is fed in at the bottom of the column and flows upwardly, irrespective of the density difference between the two phases. The behavior of solid and liquid phases was investigated through the analysis of residence time distributions. The range of working conditions has been determined. Consequently, it was found that an optimal tuning of the operating conditions (pulsation parameters, flow control) may minimize the influence of the size and density of the particles as well as uncoupling the residence time of both phases. The column has been manufactured, in order to handle a large range of solid‐liquid systems (solid treatment, purification or reaction, raw materials, floating or dense particles, polydispersed particles). On the basis of the model calculations and design considerations, preliminary data is presented on the technical and economical feasibility of the various applications mentioned above. The final aim of this study is to prove that, for a fixed production rate and product quality, the new column can satisfy the specifications required and possibly even exceed them.
A Hybrid Genetic Algorithm for the Estimation of Polyesterification Kinetic Parameters
Authors: Feng G. , Li F. , Li H. , Qu H. , Cui Y. 
Published: May 2006

AbstractA simple genetic algorithm (SGA) has been improved in this paper. The resulting hybrid genetic algorithm (HGA) was used to estimate the kinetic parameters of polyesterification between dimer fatty acid and ethylene glycol. The acid values of product predicted by the kinetic model match well with experimental data at different material proportions and conversion ratios. The kinetic model was proven to be effective. The hybrid genetic algorithm was compared with the simple genetic algorithm, and the result indicated that the improved genetic algorithm has higher efficiency, stronger ability on local searches, better precision, and a wider search range.
Transient Cooling of Heat‐Generating Materials with Thermoelectric Coolers
Authors: Makino Y. , Maruyama T. 
Published: May 2006

AbstractThe transient cooling of heat‐generating materials contacted with a thermoelectric microcooler was discussed, and the operation of a fixed electric current was proposed as an alternative to the conventional operation of a variable electric current to obtain the maximum heat flux of cooling. The changes in temperature of the materials cooled by the thermoelectric cooler were obtained by numerical calculation of the unsteady one‐dimensional energy equation. The proposed operation of a fixed current was found to be a useful alternative to the conventional operation. An approximate analysis was made on the basis of the results of the numerical calculation. The results showed that the transient response of cooling of material without heat generation could be expressed by the first‐order delay. Comparisons with the numerical calculation indicated that the expression by the first‐order delay is also applicable to the cooling of material with heat generation and that the time constant decreases with increasing rate of heat generation from the material.
Formation and Growth of Crystal Bridges in Bulk Solids
Authors: Bröckel U. , Wahl M. , Kirsch R. , Feise H. J. 
Published: May 2006

AbstractSolidification and caking of bulk solids often occurs during storage or while being transported to the customer. To investigate the formation and growth of solid bridges between two discrete particles, the modification of the contact region between these two particles stored in a climatic chamber is examined. The effect of load, temperature, relative humidity, and storage time on the formation of a bridge is analyzed. The objective is to describe the behavior of crystalline or salt‐like granules under real storage conditions.
Caking of Urea Prills
Authors: Wahl M. , Kirsch R. , Bröckel U. , Trapp S. , Bottlinger M. 
Published: May 2006

AbstractTo investigate the formation and growth of solid bridges between urea particles, the changes in the contact region between two discrete particles are measured. The work is carried out using a Double‐Particle‐System (DPS). The DPS was stored in a climatic chamber. The effect of load, temperature, relative humidity, and storage time on the formation of a bridge between these particles was analyzed. The objective was to describe the geometrical changes in the contact region and to measure the strength of the resulting interparticle bridge.
Development of an Uniaxial Caking Tester
Authors: Röck M. , Ostendorf M. , Schwedes J. 
Published: May 2006

AbstractIn a collaborative research project “Consumer Oriented Solid Transport Technology” (COSTT) funded by the European Union caking properties were measured. Several partners from industry and academia were involved in this project. The caking properties of the selected bulk solids coming from the industrial partners strongly depend on consolidation stress, consolidation time, temperature, and humidity. The consolidation of the samples to be tested was carried out in a climatic chamber, where the rapid attainment of equilibrium regarding temperature and humidity was an essential prerequisite. For testing, the principle of an uniaxial tester was chosen.
Analysis of electric field induced by ELF magnetic field utilizing generalized equivalent multipole‐moment method
Authors: Hamada Shoji , Yamamoto Osamu , Kobayashi Tetsuo 
Published: May 2006

AbstractThis paper presents a generalized equivalent multipole‐moment method for calculating three‐dimensional Laplacian fields in a multispherical system. Greengard and Rokhlin's M2M, M2L, and L2L formulas enable the multipole‐moment method to calculate the fields in general arrangement of multispheres, which involve exclusive and multilayered spherical arrangement. We applied this method to electric field calculation in biological structures induced by ELF magnetic fields. The induced electric fields in a system of three eccentric and exclusive spheres, which models the human head with two eyeballs, are calculated under the application of homogeneous and magnetic‐dipole fields. The validity of this method is successfully confirmed by comparing the calculated fields with those by the fast‐multipole surface‐charge‐simulation method. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 156(2): 1–14, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20342
A Highly Efficient and Stereocontrolled Synthesis of 2‐Deoxy‐1,5‐thioanhydro‐L‐hexitols from D‐Glycals in a Tandem Nucleophilic Displacement Reaction
Authors: Passacantilli Pietro , Centore Clara , Ciliberti Elena , Leonelli Francesca , Piancatelli Giovanni 
Published: May 2006

Abstract2‐Deoxy‐1,5‐thioanhydro‐L‐hexitols have been synthesized in a concise sequence that includes: i) ring opening of glycals with aqueous mercury(II) acetate/sodium borohydride; ii) mesylation of the free hydroxy groups of the multifunctionalized open intermediates; and iii) S‐heterocyclization by treatment with sodium sulfide. The thiosugar derivatives are obtained with a 60–80 % yield. Thus, D‐glucal and D‐galactal can be converted into the corresponding 2‐deoxy‐1,5‐thioanhydro‐L‐hexitols, while L‐rhamnal gives 3,4‐di‐O‐benzyl‐2,6‐dideoxy‐1,5‐thioanhydro‐D‐xylo‐hexitol. This straightforward chemistry is shown to be useful for the synthesis of glycosyl derivatives of 2‐deoxy‐1,5‐thioanhydro‐L‐hexitol, starting from glycosyl glycals such as D‐lactal, D‐cellobial, D‐maltal, D‐melibial and D‐gentiobial, thus avoiding the usually lengthy glycosylation procedures. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
3‐Bromopropenyl Methylcarbonate in Organic Synthesis: A Straightforward Approach to 4,5‐Disubstituted 5‐Vinyl‐1,3‐dioxolan‐2‐ones
Authors: Lombardo Marco , Pasi Filippo , Trombini Claudio 
Published: May 2006

AbstractThe reaction of 3‐bromopropenyl methylcarbonate (2) with aliphatic or aromatic aldehydes, in the presence of indium metal in N,N‐dimethylformamide, affords cis and trans 4,5‐disubstituted 5‐vinyl‐1,3‐dioxolan‐2‐ones 4 in very high isolated yields. Reactions may be run by adopting either one‐pot Barbier conditions or a two‐step Grignard protocol. The cis‐4/trans‐4 ratio is controlled by the nature of the carbonyl compound: saturated aldehydes mainly afford cis‐4, whereas conjugated aldehydes favor the formation of trans‐4. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Micellar electrokinetic capillary chromatographic method for the quantitative analysis of uricosuric and antigout drugs in pharmaceutical preparations
Authors: Kou Hwang‐Shang , Lin Tsai‐Pei , Chung Tang‐Chia , Wu Hsin‐Lung 
Published: May 2006

AbstractA simple MEKC method is described for the separation and quantification of seven widely used uricosuric and antigout drugs, including allopurinol (AP), benzbromarone (BZB), colchicine (COL), orotic acid (OA), oxypurinol (OP), probenecid (PB), and sulfinpyrazone (SPZ). The drugs were separated in a BGE of borate buffer (45 mM; pH 9.00) with SDS (20 mM) as the micellar source and the separated drugs were directly monitored with a UV detector (214 nm). Several parameters affecting the separation and analysis of the drugs were studied. Based on the normalized peak‐area ratios of the drugs to an internal standard versus the concentration of the drugs, the method is applicable to quantify BZB, COL, and SPZ (each 5–200 μM), AP, OA, OP, and PB (each 10–200 μM) with detection limits (S/N = 3, 0.5 psi, 5 s injection) in the range of 0.6–4.0 μM. The precision (RSD; n = 5) and accuracy (relative error; n = 5) of the method for intraday and interday analyses of the analytes at three levels (30, 120, and 180 μM) are below 4% (n = 3). The method was demonstrated to be suitable for the analysis of AP and COL in commercial tablets with speed and simplicity.
Development and validation of a capillary electrophoresis method with laser‐induced fluorescence detection for the determination of captopril in human urine and pharmaceutical preparations
Authors: Pérez‐Ruiz Tomás , Martínez‐Lozano Carmen , Galera Raquel 
Published: May 2006

AbstractThis study describes the development of a CE method for the analysis of the antihypertensive drug captopril using LIF detection. The method is based on the derivatization of captopril with the fluorescent label 5‐iodoacetamidofluorescein. The optimization of the electrophoretic electrolyte composition together with other variables, such as applied voltage and injection time, resulted in a solution of 20 mM phosphate buffer adjusted to pH 12.0. The calibration curve for the fluorescent captopril derivative was linear in the concentration range 3.5–6000 ng/mL with a detection limit of 0.5 ng/mL. Intra‐ and interday precision (at a concentration of about 100 times the LOD) were less than 0.86 and 1.16%, respectively, both expressed as RSD. The assay was successfully used for quantification of captopril in some marketed pharmaceutical preparations and urine samples.
Determination of phenothiazines in pharmaceutical formulations and human urine using capillary electrophoresis with chemiluminescence detection
Authors: Lara Francisco J. , García‐Campaña Ana M. , Gámiz‐Gracia Laura , Bosque‐Sendra Juan M. , Alés‐Barrero Fermín 
Published: May 2006

AbstractA CE instrument coupled with chemiluminescence (CL) detection was designed for the determination of promethazine hydrochloride (PTH) and promazine hydrochloride (PMH) in real samples. An important enhancement of the CL emission of luminol with potassium ferricyanide was observed in the presence of these phenothiazines; so this system was selected for their detection after CE separation. Parameters affecting the electrophoretic separation were optimized in a univariate way, while those affecting CL detection were optimized by means of a multivariate approach based on the use of experimental designs. Chemometrics was also employed for the study of the robustness of the factors influencing the postcolumn CL detection. The method allows the separation of the phenothiazines in less than 4 min, achieving LODs of 80 ng/mL for PMH and 334 ng/mL for PTH, using sample injection by gravity. Electrokinetic injection was used to obtain lower LODs for the determination of the compounds in biological samples. The applicability of the CE‐CL method was illustrated in the determination of PTH in pharmaceutical formulations and in the analysis of PMH in human urine, using a previous SPE procedure, achieving an LOD of 1 ng/mL and recoveries higher than 85%.
Neural basis of first and second language processing of sentence‐level linguistic prosody
Authors: Gandour Jackson , Tong Yunxia , Talavage Thomas , Wong Donald , Dzemidzic Mario , Xu Yisheng , Li Xiaojian , Lowe Mark 
Published: May 2006

AbstractA fundamental question in multilingualism is whether the neural substrates are shared or segregated for the two or more languages spoken by polyglots. This study employs functional MRI to investigate the neural substrates underlying the perception of two sentence‐level prosodic phenomena that occur in both Mandarin Chinese (L1) and English (L2): sentence focus (sentence‐initial vs. ‐final position of contrastive stress) and sentence type (declarative vs. interrogative modality). Late‐onset, medium proficiency Chinese‐English bilinguals were asked to selectively attend to either sentence focus or sentence type in paired three‐word sentences in both L1 and L2 and make speeded‐response discrimination judgments. L1 and L2 elicited highly overlapping activations in frontal, temporal, and parietal lobes. Furthermore, region of interest analyses revealed that for both languages the sentence focus task elicited a leftward asymmetry in the supramarginal gyrus; both tasks elicited a rightward asymmetry in the mid‐portion of the middle frontal gyrus. A direct comparison between L1 and L2 did not show any difference in brain activation in the sentence type task. In the sentence focus task, however, greater activation for L2 than L1 occurred in the bilateral anterior insula and superior frontal sulcus. The sentence focus task also elicited a leftward asymmetry in the posterior middle temporal gyrus for L1 only. Differential activation patterns are attributed primarily to disparities between L1 and L2 in the phonetic manifestation of sentence focus. Such phonetic divergences lead to increased computational demands for processing L2. These findings support the view that L1 and L2 are mediated by a unitary neural system despite late age of acquisition, although additional neural resources may be required in task‐specific circumstances for unequal bilinguals. Hum. Brain Mapp, 2007. © 2006 Wiley‐Liss, Inc.