bluuebunny/crossref_metadata_2025_split huggingface dataset:
Forced splitting of fractions in CE
Authors: Zalewski Dawid R. , Schlautmann Stefan , Gardeniers Han J. G. E. 
Published: January 2009

AbstractIn order to increase the electrophoretic separation between fractions of analytes on a microfluidic chip, without the need for a longer separation channel, we propose and demonstrate a preparative electrokinetic procedure by which overlapping or closely spaced fractions are automatically split. The method involves an extra T‐junction at the end of a separation channel and detector‐triggered reconfiguration of voltages at channel outlets. Forced splitting of a separated four‐component mixture is demonstrated, and possible sources of errors leading to contamination of split fractions are also discussed in detail and illustrated both by computational fluid dynamics and experiments. The splitting method can be applied in preparative CE‐on‐a‐chip systems, for which it greatly simplifies downstream fraction manipulation and helps in reducing cross‐contamination between collected fractions.
Enhancing price‐responsiveness of end‐use customers' loads: dynamically administered critical peak pricing
Authors: Joo Jhi‐Young , Ahn Sang‐Ho , Yoon Yong Tae 
Published: January 2009

AbstractThe purpose of this paper is to examine the economic and technical perspectives of dynamically administered critical peak pricing (DA‐CPP) program as an active demand response (DR) program. To implement a good DR program, there are three perspectives to be considered: regulatory, economic, and technical perspectives. We propose a special DA‐CPP program as an effective DR program, which is administered by an energy service provider (ESP). ESP has control on when to call critical peaks on this program. This gives both the administrator and the end‐use customers incentives to reduce loads on critical moments. We will assume that the regulatory perspective of DR is determined as a DA‐CPP program and examine the other two. The economic perspective of DA‐CPP program is the incentive of the program administrator, or the profit of an ESP. The technical perspective is a method to maximize the incentive of DA‐CPP program, or an ESP's profit. An ESP should decide when to call critical peaks within certain constraints to maximize her profit. This is done by predicting the market prices and following a similar method as evaluating a swing option. The numerical example will show the optimal critical peak decisions. Copyright © 2008 John Wiley & Sons, Ltd.
The effect of the programs for demand response incentives in competitive electricity markets
Authors: Bompard Ettore , Napoli Roberto , Wan Bo 
Published: January 2009

AbstractThe special features of electricity such as non‐storability and lack of good substitutes, the network related market power and the demand inelasticity result in high volatile electricity prices in pool markets, especially during peak hours. Demand response (DR) programs with the aid of distributed energy resources (DER) provide the means to increase demand elasticity and, as a consequence, to counteract the effect of market power.This paper aims to assess the effectiveness of DR programs and try to answer to what extend DR programs will increase the demand elasticity and to what degree it will reduce the market power. Two DR programs, that is, time of use (TOU) rate and economic load response program (ELRP) are considered in this paper and the possible price responsiveness of load is modeled as linearly correlated to the difference of day and night TOU rate and the compensation price of load curtailment in order to determine the demand elasticity frontier. Game theory is employed to model the strategic bidding of generation companies (GenCos) and the Lerner index is used to quantify the market power. The proposed model is applied in Italian electricity market for numerical study. Copyright © 2008 John Wiley & Sons, Ltd.
Tagebuch eines Tausendsassas
Authors: Unterstell Rembert 
Published: January 2009

AbstractKaiserreich, Republik, Diktatur: Harry Graf Kessler war der Chronist seiner Epoche. Am Deutschen Literaturarchiv Marbach wird sein Jahrhundertprotokoll mit großer Akribie ediert – Seite für Seite ein faszinierendes Bild des „alten Europas”︁
A comparison of alternative approaches for determining the downside risk of hedge fund strategies
Authors: Giamouridis Daniel , Ntoula Ioanna 
Published: January 2009

AbstractIn this study, we compare a number of different approaches for determining the Value at Risk (VaR) and Expected Shortfall (ES) of hedge fund investment strategies. We compute VaR and ES through both model‐free and mean/variance and distribution model‐based methods. Certain specifications of the models that we considered can technically address the typical characteristics of hedge fund returns such as autocorrelation, asymmetry, fat tails, and time‐varying variances. We find that conditional mean/variance models coupled with appropriate assumptions on the empirical distribution can improve the prediction accuracy of VaR. In particular, we observed the highest prediction accuracy for the predictions of 1% VaR. We also find that the goodness of ES prediction models is primarily influenced by the distribution model rather than the mean/variance specification. © 2009 Wiley Periodicals, Inc. Jrl Fut Mark 29:244–269, 2009
Orienting neurite growth in electrospun fibrous neural conduits
Authors: Yao Li , O'Brien Norah , Windebank Anthony , Pandit Abhay 
Published: January 2009

AbstractIn cases where direct suture of two nerve stumps is not feasible, generally a scaffold is required to bridge the gap and guide nerve regeneration. The scaffold used in nerve tissue engineering applications requires optimal guidance effect, mechanical strength, and cellular compatibility. A number of studies suggest that fibrous scaffolds can potentially be used for nerve regeneration, as the aligned fibers can provide the guidance effect for axonal growth and the fibrous structure mimics the nerve microenvironment. A practical method to fabricate the fibrous nerve conduit with structural guidance cue for neurite growth will improve its potential application in neural tissue engineering. In this study, fibrous tubular scaffolds were fabricated using an electrospinning technique. The fibrous conduit was composed of aligned fibers in the interior layer and randomly oriented fibers in the exterior layer. In order to investigate the fiber diameter on neurite extension and directional growth, fibers with different diameter in the subcellular size range were fabricated and the neurite growth on these fibers was investigated. We observed that PC12 cells' neurites showed similar parallel growth on the aligned fibers irrespective of fiber diameter. Neurite length on aligned fibers, with fiber diameters of 3.7 ± 0.5 μm and 5.9 ± 0.9 μm, was significantly longer than neurite length on randomly oriented fibers. This study showed that electrospinning provides a practical solution to fabricate fibrous nerve conduit by controlling the conduit inner diameter and fiber alignment and, hence, potentially improves the application of the conduit in neural regeneration. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Exploring the reactivity of framework vanadium, niobium, and tantalum sites in zeolitic materials using DFT reactivity descriptors
Authors: Tielens Frederik 
Published: January 2009

AbstractThe acid‐base properties of zeolites with group 5 transition metal framework sites are investigated, and a first step into the understanding of their acid/base and redox properties is undertaken using DFT reactivity descriptors. It is evidenced, using sodalite as model system, that zeolites with vanadium framework sites are more nucleophilic than zeolites with niobium and tantalum framework sites. It is predicted that the formation of carbonates would be favorable in zeolites with Ta framework sites compared with V framework sites, whereas the basicity of the bridging oxygens is predicted to interact preferentially with a soft nucleophile. In this context, the poisoning of the deNOx catalysts in the presence of SO2 is discussed. © 2009 Wiley Periodicals, Inc. J Comput Chem 2009
Multiple sequence alignment algorithm based on a dispersion graph and ant colony algorithm
Authors: Chen Weiyang , Liao Bo , Zhu Wen , Xiang Xuyu 
Published: January 2009

AbstractIn this article, we describe a representation for the processes of multiple sequences alignment (MSA) and used it to solve the problem of MSA. By this representation, we took every possible aligning result into account by defining the representation of gap insertion, the value of heuristic information in every optional path and scoring rule. On the basis of the proposed multidimensional graph, we used the ant colony algorithm to find the better path that denotes a better aligning result. In our article, we proposed the instance of three‐dimensional graph and four‐dimensional graph and advanced a special ichnographic representation to analyze MSA. It is yet only an experimental software, and we gave an example for finding the best aligning result by three‐dimensional graph and ant colony algorithm. Experimental results show that our method can improve the solution quality on MSA benchmarks. © 2009 Wiley Periodicals, Inc. J Comput Chem 2009
Molecular mechanisms of nitric oxide‐dependent inhibition of TPA‐induced matrix metalloproteinase‐9 (MMP‐9) in MCF‐7 cells
Authors: Jespersen Christine , Doller Anke , Akool El‐Sayed , Bachmann Malte , Müller Roswitha , Gutwein Paul , Mühl Heiko , Pfeilschifter Josef , Eberhardt Wolfgang 
Published: January 2009

AbstractMatrix metalloproteinase‐9 (MMP‐9) is implicated in the invasion and metastasis of breast cancer cells. We investigated the modulatory effects of nitric oxide (NO) on the 12‐O‐tetradecanoylphorbol 13‐acetate (TPA)‐induced MMP‐9 expression in MCF‐7 cells. Different chemical NO donors inhibited the extracellular content of TPA‐induced MMP‐9 protein and MMP‐9 activity as assessed by gelatin‐zymography and ELISA, respectively. Concomitant with the reduction in the extracellular MMP‐9 content NO strongly decreased the steady‐state levels of MMP‐9 mRNA which in turn leads to a lower recruitment of MMP‐9 transcripts to polysomes and to a diminished MMP‐9 translation. Reporter gene assays revealed that the inhibition in MMP‐9 expression by NO is mainly attributed to a 0.67 kb fragment of the 5′‐promoter region of the MMP‐9 gene but independent of the 3′untranslated region thus indicating that MMP‐9 suppression by NO mainly results from transcriptional events. Electrophoretic mobility shift assays (EMSA), showed that NO specifically interferes with the TPA‐induced DNA binding affinity of c‐Jun and c‐Fos without affecting the TPA‐induced increase in the levels of the transcription factors. Using pharmacological inhibitors and small interfering (si)RNA we found that PKCδ is indispensably involved in the TPA‐triggered MMP‐9 expression. Concomitantly, the TPA‐evoked increase in total PKC activity was strongly attenuated in the lysates from NO‐treated MCF‐7 cells, thus suggesting that NO attenuates TPA‐triggered MMP‐9 mainly through a direct inhibition of PKCδ. Modulation of MMP‐9 by NO highlights the complex roles of NO in the regulation of MMP‐9 in breast cancer cells. J. Cell. Physiol. 219: 276–287, 2009. © 2009 Wiley‐Liss, Inc.
Localization and role of galanin in the thyroid gland of Podarcis sicula lizard (reptilia, lacertide)
Authors: Sciarrillo Rosaria , Capaldo Anna , Valiante Salvatore , Laforgia Vincenza , De Falco Maria 
Published: January 2009

AbstractGalanin (GAL) is a 29‐amino acid residue neuropeptide, which was initially isolated from porcine intestine extracts and since then, widely found in a variety of vertebrate organs, in correlation with multiple neuro‐hormonal actions exerted and so receiving a constantly growing attention. Moreover, although the studies undertaken so far suggest a local intrathyroidal peptidergic regulatory action, the exact role of GAL on thyroid gland remains to be established. The aim of this study was to determine in the lizard, Podarcis sicula, (1) the presence of GAL immunoreactivity in the thyroid gland and (2) the short‐ and long‐term effects of in vivo GAL administration by intraperitoneal injection on thyroid gland physiology. First of all, the presence of GAL in the thyroid gland of P. sicula was demonstrated by immunohistochemical technique (avidin–biotin–peroxidase complex—ABC method). Second, the role of GAL in the control of thyroid gland activity was studied in vivo using light microscopy (LM) technique coupled to a specific radioimmunoassay for thyroid‐stimulating hormone (TSH) and thyroid hormones (T4 and T3). Prolonged GAL administration [(0.4 mg/100 g body wt)/day] increased T4 and T3 release, but decreased the plasma concentration of TSH. In addition, using LM clear signs of stimulation of the thyroid gland were observed. These findings suggest that systemic administration of GAL was able to stimulate the thyroid gland of the lizard both at morphological and physiological level. J. Exp. Zool. 311A:199–206, 2009. © 2009 Wiley‐Liss, Inc.
Spatial variability of topsoils and vegetation in a grazed steppe ecosystem in Inner Mongolia (PR China)
Authors: Steffens Markus , Kölbl Angelika , Giese Marcus , Hoffmann Carsten , Totsche Kai Uwe , Breuer Lutz , Kögel‐Knabner Ingrid 
Published: January 2009

AbstractIt is not clear from the literature how the spatial distribution of topsoil and vegetation properties is affected by grazing cessation. Thus, the objective of this study was to elucidate if long‐term grazing exclosure increases spatial heterogeneity of topsoil and vegetation properties in a steppe ecosystem in NE China. Variograms and crossvariograms were calculated for bulk density, organic carbon (OC), total N, and total S concentration, δ13C, pH, Ah horizon thickness, vegetation cover, and aboveground biomass. Five sites with different grazing intensities (ungrazed since 1979, ungrazed since 1999, winter grazing, continuously grazed, heavily grazed) were sampled with two different grid sizes, allowing the exploration of scale effects. Small grids (15 m spacing, 5 m nested sampling) exhibited a different spatial structure compared to large grids (50 m spacing, 10 m nested sampling). Spatial distribution in small grids changed with grazing intensity. Generally, heterogeneity of topsoil properties increased with decreasing grazing intensity from a homogeneous to a patchy distribution. We attribute this to vegetation recovery/succession and deposition of windblown material in ungrazed areas. The plot ungrazed since 1999 showed different spatial dependencies than continuously and heavily grazed plots, but has not yet reached the high variability of the plot which was ungrazed since 1979. Large grid sampling did not detect small‐scale variability or grazing impacts, but showed spatial dependencies that were attributed to topography or soil erosion/deposition. Low OC concentration and low Ah thickness were associated with hilltop and shoulder positions, resulting in lower OC stocks at these topographic units.
A Progressive Laser Joining Method
Authors: Horn Wolfgang 
Published: January 2009

AbstractA newly designed galvo scanner combines the advantages of closed‐loop temperature control by integrated onaxis pyrometer and fast beam deflection. It is used in quasi‐simultaneous polymer welding as well as in selective reflow soldering where several solder joints have to be processed within the working area without using mechanical positioning. The temperature controlled processes are characterized by robustness and increased stability.
Blendable Peptide‐Polymer Nanofibers to Modulate Mechanical Properties of Polymers
Authors: Hentschel Jens , Börner Hans G. 
Published: January 2009

AbstractThe self‐assembly kinetics of a peptide‐block‐poly(n‐butyl acrylate) copolymer (pnBA‐$(TV)_{\rm 5}^{{\rm switch}} n{\rm FG}$ conjugate) in solution and the blend behavior of the resulting fibrillar nanoobjects are investigated. By using a switch peptide segment with temporarily suppressed aggregation behavior, the solution self‐assembly of the peptide‐polymer conjugate can be triggered via a small change in the pHapp.. This results in a controlled assembly of the peptide segments and thus the organization of the bioconjugate. The process was followed by time dependent determination of the dynamic viscosity of the aggregation solution and by AFM that allows visualization of the corresponding structures. The obtained anisotropic nanofibers are characterized in solution and in bulk by SAXS, showing a worm‐like characteristic. Blend behavior is investigated, proving the homogeneous dispersibility of the nanofibers in poly(acrylate)s. It could be demonstrated that the nanofibers are modulating the mechanical properties of pnBA by mechanisms of molecular reinforcement, having a distinct stiffening effect.magnified image
Carbonate Couplers and Functional Cyclic Carbonates from Amino Acids and Glucosamine
Authors: Fricke Nicole , Keul Helmut , Möller Martin 
Published: January 2009

AbstractOn the basis of glycerol carbonate, four coupling reagents 3a‐d were prepared. Their synthesis and characterisation, starting from glycerol carbonate 2, is described. To evaluate the differences in reactivity these couplers were reacted with valine methyl ester and the results were compared with the already known coupler 3a. Reaction conditions influenced the conversion of the couplers 3a‐d containing phenyl, 4‐nitrophenyl, imidazolyl and acetone oxime leaving groups; highest conversion and fastest reaction rates were obtained with 3b. The coupling reagents 3a and b were used for the synthesis of functional carbonate building blocks from amino acid methyl esters and glucosamine.magnified image
Encapsulation of a Single Metal Nanoparticle with Tunable Size in a Monodisperse Polymer Microcapsule
Authors: Li Haiqing , Ha Chang‐Sik , Kim Il 
Published: January 2009

AbstractA versatile approach to fabricate monodisperse poly[styrene‐co‐(divinyl benzene)] (PS‐co‐DVB) microcapsules that contain a single gold nanoparticle (AuNP) has been demonstrated. Using the PS‐co‐DVB microcapsule as a microreactor, aqueous HAuCl4 and NaBH4 solutions are subsequently infiltrated. The size of the resulting AuNP inside of the PS‐co‐DVB microcapsules is easily tunable by controlling the repeated infiltration cycles of aqueous HAuCl4 and NaBH4. PS‐co‐DVB microcapsules that contain a single silver and palladium nanoparticle are also obtained by following a similar protocol.magnified image
Superelectrophilic Activation of N‐Substituted Isatins: Implications for Polymer Synthesis, a Theoretical Study
Authors: Nieto Daniel Romero , Fomine Serguei , Zolotukhin Mikhail G. , Fomina Lioudmila , Hernandez Maria del Carmen Gutiérrez 
Published: January 2009

AbstractThe stability and reactivity of mono‐ and multi‐protonatred N‐substituted isatin derivatives were studied at PBE0/aug‐cc‐pvtz//PBE0/6‐31+G** level of theory in triflic acid (TFSA) solution. Calculations showed that the monocationic intermediates are the principal reactive species in the reaction of hydroxyalkylation of isatin derivatives in TFSA media. Electron‐withdrawing substituents on the nitrogen atom increase the reactivity of isatin‐containing electrophiles towards aromatic hydrocarbons, in accordance with their expected electronic influence. Steric factors also play an important role in the reactivity of isatin‐containing electrophiles, especially in the second reaction step, due to their more sterically hindered reactive center.magnified image
Predicting Short‐Term Urinary Retention After Vaginal Prolapse Surgery
Authors: Hakvoort Robert A. , Dijkgraaf Marcel G. , Burger Matthe P. , Emanuel Mark H. , Roovers Jan Paul W.R. 
Published: January 2009

AbstractAimsIdentification of risk factors for urinary retention after vaginal prolapse surgery.MethodsThe medical records of 345 women undergoing surgical correction for symptomatic pelvic organ prolapse were analyzed. Independent risk factors for the development of post‐operative urinary retention were identified by performing univariate and multivariate logistic regression analysis. Variables included in the analysis were age, parity, body mass index, previous prolapse surgery, previous hysterectomy, menopausal status, degree of prolapse, type of anesthesia, type and technique of surgery, operation time, intra‐operative blood loss, preoperative urinary stress‐incontinence, and other co‐morbidities. Main outcome measure was the occurrence of urinary retention defined as a residual volume after voiding higher than 200 ml as measured by bladder scan.ResultsHigh grade cystocele (OR 2.5, CI 1.3–4.7), performing levator plication (OR 4.3, CI 2.0–9.3), performing Kelly plication (OR 5.1, CI 1.7–15.5) and amount of intra‐operative blood loss (OR 1.4 per 100 ml, CI 1.1–1.8) were identified as independent risk factors for the occurrence of urinary retention after vaginal prolapse surgery.ConclusionsUrinary retention after vaginal prolapse surgery occurs more frequently in women with larger cystoceles, severe intra‐operative blood loss and the application of levator plication and Kelly plication. Neurourol. Urodynam. 28:225–228, 2009. © 2008 Wiley‐Liss, Inc.
Selective precipitation of plasmid with a water‐soluble cationic surfactant
Authors: Ataci Nese , Correia Isabell , Arisan Inci , Marcos João Carlos 
Published: January 2009

AbstractThe aim of the present study was the selective precipitation of plasmid directly from alkaline lysate produced from bacterial culture with the cationic detergent, N, N', N'‐polyethylene (10)‐N tallow‐1, 3‐di amine propane. Polyethylene groups of peg‐10 tallow were functionalized with tertiary amine groups and long alkyl chain. The functional groups of cationic detergent were determined by means of 1H nuclear magnetic resonance (NMR) spectroscopy. A simple and efficient process for plasmid purification by cationic detergent was found to be dependent on acid concentration. The structure of peg‐10 tallow cationic detergent after adding acid solution was characterized using Fourier transform infrared (FT‐IR) spectroscopy. Inorganic acid such as HCl was introduced into the solution of peg‐10 tallow. Controlling pH of precipitation system by the addition of different concentrations of HCl acid solutions on peg‐10 tallow improved the partial separation of RNA from plasmid DNA (pDNA). However, different lysate masses were applied to observe the effect of 7.5% acid solution on the separation of RNA from pDNA with a peg‐10 tallow cationic surfactant. The results were realized by 1% agarose gel analysis. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis and characterization of fluorene‐based rod–coil liquid crystal polymers
Authors: Yang Gui‐Zhong , Chen Xiao‐Lei , Wang Lu‐Min , Shi Jian‐Gao , Li Chun‐Zhong , Liu Tianxi 
Published: January 2009

AbstractA series of fluorene‐based rod–coil liquid crystal polymers with different lengths of the coil segments on backbones were designed and synthesized by a palladium‐catalyzed Suzuki coupling‐reaction. The thermal stability, the UV–Vis absorption and fluorescence spectra in chloroform solution and thin film, the electrochemical properties, thermal behavior, and morphology of these rod–coil polymers were investigated. The thermal stability of these polymers steadily decreased on increasing the length of the coil segments on the backbone; their optical and electrochemical properties did not exhibit noticeable dependence on the weight fraction of the coil segments. However, the shoulder emission and the full width at the half‐maximum (FWHM) in PL spectra of the films increased, whereas the oxidation onset potentials and the corresponding HOMO energy levels decreased with the increase in the weight fraction of the coil segments, which was assigned to microphase separation and formation of folded chain conformation as the weight fraction of the coil segments increased. These polymers displayed a characteristic liquid crystalline texture. The variation of the weight fraction of the coil segments obviously affected the thermal behavior and morphology of these rod–coil polymers. Copyright © 2008 John Wiley & Sons, Ltd.