bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of direct current dielectrophoresis on the trajectory of a non‐conducting colloidal sphere in a bent pore
Authors: House Dustin L. , Luo Haoxiang 
Published: October 2011

AbstractDielectrophoresis has shown a wide range of applications in microfluidic devices. Force approximations utilizing the point‐dipole method in dielectrophoresis have provided convenient predictions for particle motion by neglecting interactions between the particle and its surrounding electric and flow fields. The validity of this approach, however, is unclear when the particle size is comparable to the characteristic length of the channel and when the particle is in close proximity to the channel wall. To address this issue, we apply an accurate numerical approach based on the boundary‐element method (BEM) to solve the coupled electric field, flow, and particle motion. This method can handle much closer particle–wall distances than the other numerical approaches such as the finite‐element method. Using the BEM and integrating the Maxwell stress tensor, we simulate an electrokinetic, spherical particle moving within a bent cylindrical pore to investigate how the dielectrophoretic force affects the particle's trajectory. In the simulation, both the particle and the channel wall are non‐conducting, and the electric double layers adjacent to the solid surfaces are assumed to be thin with respect to the particle radius and particle–wall gap. The results show that as the particle comes close to the wall, its finite size has an increasingly important effect on its own transient motion and the point‐dipole approximation may lead to significant error.
Screening and characterization of microorganisms capable of converting iminodiacetonitrile to iminodiacetic acid
Authors: Zhang Jin‐Feng , Liu Zhi‐Qiang , Zheng Yu‐Guo , Shen Yin‐Chu 
Published: October 2011

AbstractFor screening and isolation of microorganisms harboring nitrile‐hydrolyzing enzymes that mediate the hydrolysis of iminodiacetonitrile (IDAN) to iminodiacetic acid (IDA), a sensitive and specific high‐throughput screening model was established. This model integrated a solid screen‐selective culture medium plate with bromcresol purple as the pH indicator coupled to Cu‐IDA complex spectrophotometry. Four strains were selected to perform the biotransformation to IDA, which were isolated and identified as Alcaligenes faecalis, Pseudomonas chlororaphis, Pseudomonas putida and Klebsiella pneumoniae, on the basis of 16S rDNA sequence analysis in combination with physiological and biochemical characterization. Moreover, the maximum specific enzyme activity was 73.4 U/g dry cell weight obtained by A. faecalis ZJUTBX11 after optimization of the medium conditions for enzyme production. The results show that the proposed model is a suitable method for screening microorganisms with nitrile‐hydrolyzing enzymes. We suggest the A. faecalis ZJUTBX11 strain to be used for large‐scale bioconversion of IDAN to IDA, because of its excellent performance in the production of IDA.
Serum free light chains in myeloma patients with an intact M protein by immunofixation: potential roles for response assessment and prognosis during induction therapy with novel agents
Authors: Mori Sherry , Crawford Brooke S , Roddy Julianna VF , Phillips Gary , Elder Pat , Hofmeister Craig C , Efebera Yvonne , Benson Don M 
Published: October 2011

AbstractThe ascertainment of serum free light chain (sFLC) levels has been shown to be valuable in screening for the presence of plasma cell dyscrasia as well as for baseline prognosis in newly diagnosed patients. For patients with amyloidosis and those with oligo‐secretory or non‐secretory multiple myeloma (MM), serial measurement of sFLC has also been shown to be valuable in monitoring disease status. However, in patients with a measureable, intact monoclonal protein by immunofixation (M protein), the serial measurement of sFLC remains undefined and is currently not recommended in professional guidelines. Herein, we provide data comparing sFLC with M protein as biomarkers of response in newly diagnosed patients with MM undergoing induction therapy with the novel agents thalidomide, lenalidomide and/or bortezomib. We show that although M protein appears to outperform sFLC comparatively over the course of induction therapy, the addition of FLC to M protein further informs the characterization of residual disease status post‐induction. Moreover, sFLC at the time of stem cell mobilization appears to hold prognostic power for survival endpoints following high‐dose chemotherapy/autologous stem cell transplant (HDC/SCT). These findings suggest potentially novel roles for sFLC in patients with MM with an intact M protein receiving novel agent‐based induction strategies followed by HDC/SCT. Copyright © 2011 John Wiley & Sons, Ltd.
Selenoglutathione‐Mediated Rescue of Kinetically Trapped Intermediates in Oxidative Protein Folding
Authors: Metanis Norman , Foletti Carlotta , Beld Joris , Hilvert Donald 
Published: October 2011

AbstractSelenoglutathione has been shown to have considerable potential as a catalyst of oxidative protein folding. Here we examine how this reagent modulates the folding pathway of bovine pancreatic trypsin inhibitor (BPTI) and show that the diselenide increases the efficiency of this process primarily by accelerating the conversion of a kinetically trapped folding intermediate.
Many routes to a micro RNA
Authors: Yeo Janet H. C. , Chong Mark M. W. 
Published: October 2011

AbstractMicro RNAs (miRNAs) are ∼22 nt small RNAs that function as posttranscriptional negative regulators of gene expression. Thousands of these molecules have so far been identified across the metazoan and plant kingdoms. Although most miRNAs share the same biogenesis pathway, numerous noncanonical miRNAs and other small RNAs have also been identified. In this review, we will discuss these alternate small RNA biogenesis pathways as well as recent discoveries of non‐miRNA functions of the miRNA biogenesis machinery. This review will focus only on metazoan pathways. © 2011 IUBMB IUBMB Life, 63(11): 972–978, 2011
Insight into the role of a unique SSEHA motif in the activity and stability of Helicobacter pylori arginase
Authors: Srivastava Abhishek , Dwivedi Nidhi , Samanta Uttamkumar , Sau Apurba Kumar 
Published: October 2011

AbstractArginase is a binuclear Mn2+‐metalloenzyme of urea cycle that hydrolyzes arginine to ornithine and urea. Unlike other arginases, the Helicobacter pylori enzyme is selective for Co2+ and has all conserved motifs except 88SSEHA92 (instead of GGDHS). To examine the role of this motif in the activity and stability, steady‐state kinetics, mutational analysis, thermal denaturation, and homology modeling were carried out. With a series of single and double mutants, we show that mutations of Ser88 and Ala92 to its analogous residues in other arginases individually enhance the catalytic activity. This is supported by the modeling studies, where the motif plays a role in alteration at the active site structure compared to other arginases. Mutational analysis further shows that both Glu90 and His91 are important for the activity, as their mutations lead to significant decrease in the catalytic efficiency but they appear to act in two different ways; Glu90 has a more catalytic role as its mutant displays binding of the two metal ions per monomer of the protein, but His91 plays a critical role in retaining the metal ion at the active site as its mutation exhibits a loss of one metal ion. Thermal denaturation studies demonstrated that Ser88 and His91 both play crucial roles in the stability of the protein as their mutants showed a decrease in the Tm by ∼10–11°. Unlike wild type, the metal ions have larger role in providing the stability to the mutant proteins. Thus, our data demonstrate that the motif not only plays an important role in the activity but also critical in the stability of the protein. © 2011 IUBMB IUBMB Life, 63(11): 1027–1036, 2011
A new function for the calcineurin b subunit: Antiplatelet aggregation and anticoagulation
Authors: Su Zhenyi , Xin Shuai , Li Jing , Guo Junxia , Long Xianlian , Cheng Jinbo , Wei Qun 
Published: October 2011

AbstractCalcineurin is the only Ca2+/calmodulin‐dependent serine/threonine protein phosphatase. The roles of the cytosolic calcineurin have been well researched; however, the roles of the serum calcineurin remain unknown. Here, we report that the recombinant human calcineurin B subunit (CnB) can bind to rabbit platelets and show an antiplatelet aggregation activity. Furthermore, CnB exerts an anticoagulant effect by prolonging the activated partial thromboplastin time and thrombin time and reducing the plasma fibrinogen concentration in a dose‐dependent manner. We further reveal that the functional domain associated with the anticoagulant activity of CnB is located in the C‐terminus. Hemolysis test and intravenous stimulation study show that the recombinant CnB does not cause obvious hemolysis and is safe for intravenous injection. These results reveal a new function of calcineurin B subunit. They also give an explanation for the roles of calcineurin B subunit in serum and point to a possible implication in antithrombotic therapy. © 2011 IUBMB IUBMB Life, 63(11): 1037–1044, 2011
EUCLIDEAN REVEALED PREFERENCES: TESTING THE SPATIAL VOTING MODEL
Authors: Henry Marc , Mourifié Ismael 
Published: October 2011

SUMMARYIn the spatial model of voting, voters choose the candidate closest to them in the ideological space. Recent work by Degan and Merlo in 2009 shows that it is falsifiable on the basis of individual voting data in multiple elections. We show how to tackle the fact that the model only partially identifies the distribution of voting profiles and we give a formal revealed preference test of the spatial voting model in three national elections in the USA, and strongly reject the spatial model in all cases. We also construct confidence regions for partially identified voter characteristics in an augmented model with unobserved valence dimension, and identify the amount of voter heterogeneity necessary to reconcile the data with spatial preferences. Copyright © 2011 John Wiley & Sons, Ltd.
Differential biodistribution of oncolytic poxvirus administered systemically in an autochthonous model of hepatocellular carcinoma
Authors: Baril Patrick , Touchefeu Yann , Cany Jeannette , Cherel Yan , Thorne Steve H. , Tran Lucile , Conchon Sophie , Vassaux Georges 
Published: October 2011

AbstractBackgroundPreclinical studies have demonstrated that, unlike oncolytic adenoviruses, oncolytic vaccinia viruses can reach implanted tumors upon systemic injection. However, the biodistribution of this oncolytic agent in in situ autochthonous tumor models remains poorly characterized. In the present study, we assessed this biodistribution in a model of mouse hepatocellular carcinoma (HCC) obtained after injection of the carcinogen diethylnitrosamine (DEN).MethodsTwelve months after DEN administration, histology, quantitative reverse transcription‐polymerase chain reaction, in situ hybridization and viral titration were used to characterize tumors, as well as to assess the viral load of the livers upon either intravenous or intraperitoineal injection.ResultsThe results obtained showed that the architecture of the liver was lost, with a noticeable absence of sinusoids, as well as the presence of steatosis and α‐fetoprotein‐positive HCC tumor nodules. Bioluminescence imaging and measures of the infective virus load demonstrated that intravenous injection of 108 plaque‐forming units of the recombinant vaccinia virus led to a predominant transduction of the liver, whereas intraperitoneal injection resulted in a lower level of liver transduction accompanied by an increased infection of the lungs, spleen, kidneys and bowels. Immunohistochemical analysis of liver sections of animals injected intravenously with the virus revealed a preferential localization of vaccinia‐specific immunoreactivity in the tumors.ConclusionsThe findings of the present study emphasize the importance of the route of administration of the vector and highlight the relevance of systemic injection of oncolytic vaccinia virus in the context of hepatocellular carcinoma. Copyright © 2011 John Wiley & Sons, Ltd.
Differences in designations of observation care in US freestanding children's hospitals: Are they virtual or real?
Authors: Macy Michelle L. , Hall Matthew , Shah Samir S. , Hronek Carla , Del Beccaro Mark A. , Hain Paul D. , Alpern Elizabeth R. 
Published: October 2011

AbstractOBJECTIVE:To characterize practices related to observation care and to examine the current models of pediatric observation medicine in US children's hospitals.DESIGN:We utilized 2 web‐based surveys to examine observation care in the 42 hospitals participating in the Pediatric Health Information System database. We obtained information regarding the designation of observation status, including the criteria used to admit patients into observation. From hospitals reporting the use of observation status, we requested specific details relating to the structures of observation care and the processes of care for observation patients following emergency department treatment.RESULTS:A total of 37 hospitals responded to Survey 1, and 20 hospitals responded to Survey 2. Designated observation units were present in only 12 of 31 (39%) hospitals that report observation patient data to the Pediatric Health Information System. Observation status was variably defined in terms of duration of treatment and prespecified criteria. Observation periods were limited to <48 hours in 24 of 31 (77%) hospitals. Hospitals reported that various standards were used by different payers to determine observation status reimbursement. Observation care was delivered in a variety of settings. Most hospitals indicated that there were no differences in the clinical care delivered to virtual observation status patients when compared with other inpatients.CONCLUSIONS:Observation is a variably applied patient status, defined differently by individual hospitals. Consistency in the designation of patients under observation status among hospitals and payers may be necessary to compare quality outcomes and costs, as well as optimize models of pediatric observation care.Journal of Hospital Medicine 2012;. © 2011 Society of Hospital Medicine.
Automatic lumen and outer wall segmentation of the carotid artery using deformable three‐dimensional models in MR angiography and vessel wall images
Authors: van 't Klooster Ronald , de Koning Patrick J.H. , Dehnavi Reza Alizadeh , Tamsma Jouke T. , de Roos Albert , Reiber Johan H.C. , van der Geest Rob J. 
Published: October 2011

AbstractPurpose:To develop and validate an automated segmentation technique for the detection of the lumen and outer wall boundaries in MR vessel wall studies of the common carotid artery.Materials and Methods:A new segmentation method was developed using a three‐dimensional (3D) deformable vessel model requiring only one single user interaction by combining 3D MR angiography (MRA) and 2D vessel wall images. This vessel model is a 3D cylindrical Non‐Uniform Rational B‐Spline (NURBS) surface which can be deformed to fit the underlying image data. Image data of 45 subjects was used to validate the method by comparing manual and automatic segmentations. Vessel wall thickness and volume measurements obtained by both methods were compared.Results:Substantial agreement was observed between manual and automatic segmentation; over 85% of the vessel wall contours were segmented successfully. The interclass correlation was 0.690 for the vessel wall thickness and 0.793 for the vessel wall volume. Compared with manual image analysis, the automated method demonstrated improved interobserver agreement and inter‐scan reproducibility. Additionally, the proposed automated image analysis approach was substantially faster.Conclusion:This new automated method can reduce analysis time and enhance reproducibility of the quantification of vessel wall dimensions in clinical studies. J. Magn. Reson. Imaging 2012;35:156‐165. © 2011 Wiley Periodicals, Inc.
Ultrahigh‐field DCE‐MRI of angiogenesis in a novel angiogenesis mouse model
Authors: Wittenborn Thomas , Nielsen Thomas , Nygaard Jens V. , Larsen Esben K.U. , Thim Troels , Rydtoft Louise M. , Vorup‐Jensen Thomas , Kjems Jørgen , Nielsen Niels Chr. , Horsman Michael R. , Falk Erling 
Published: October 2011

AbstractPurpose:To be able to screen and identify potential candidate agents for noninvasive imaging of diseases involving angiogenesis, a standardized in vivo angiogenesis model is needed. Angiogenesis is a common feature of many pathological conditions and has become an important target for diagnosis and treatment, with many noninvasive imaging agents emerging.Materials and Methods:Uniform scaffolds consisting of porous and flexible polycaprolactone were implanted subcutaneously in mice and studied after 1 to 6 weeks to describe the time course of angiogenesis. The model was characterized by histology and dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI).Results:Microscopic examination revealed progressive ingrowth of new vessels from the periphery, leading to a fully vascularized scaffold within 6 weeks. Blood flow through the new vessels, assessed by DCE‐MRI, revealed peripheral vascularization corresponding to 12.3% (SD 6.1%) of scaffold area at week 1 and a more uniform and complete distribution of vessels corresponding to 84.1% (SD 16.2%) of scaffold area at week 4.Conclusion:In agreement with microscopic examination, noninvasive DCE‐MRI visualized progressive development of new vessels in a novel and standardized murine angiogenesis model, making this model suitable for screening angiogenesis‐related drugs and contrast agents. J. Magn. Reson. Imaging 2012;35:703‐710. © 2011 Wiley Periodicals, Inc.
Novel unbreakable solid‐phase microextraction fiber by electrodeposition of silica sol–gel on gold
Authors: Bagheri Habib , Sistani Habiballah , Ayazi Zahra 
Published: October 2011

AbstractA new technique for preparation of an unbreakable solid‐phase microextraction (SPME) fiber, using sol–gel technology is developed. Primarily, an ultrathin two‐dimensional intermediate film was prepared by hydrolysis of 3‐(trimethoxysilyl)‐1‐propanthiol self‐assembled monolayer grafted onto gold, then a stationary phase by electrodeposition of 3‐(trimethoxysilyl)propylmethacrylate as a precursor, tetramethyl orthosilicate and polyethylene glycol as a coating polymer was produced. The scanning electron microscopy images revealed that the new fiber exhibits a rather porous and homogenous surface. The thermal stability of the fabricated fiber was investigated by thermogravimetric analysis. The applicability of the prepared fiber coating in conjunction with gas chromatography‐mass spectrometry was examined by SPME of polycyclic aromatic hydrocarbons, as model analytes, from aquatic media. An extraction time of 20 min at 50°C gave maximum peak areas when NaCl, 15% was added to the aqueous samples. Limits of detection were in the range of 0.01–0.02 ng/mL and relative standard deviation values were in the range of 4–16% at 1 ng/mL. The developed method was successfully applied for the analysis of real water samples while the relative recovery percentage was in the range of 102–118%.
Method development for fingerprinting of biodiesel blends by solid‐phase extraction and gas chromatography–mass spectrometry
Authors: Yang Zeyu , Hollebone Bruce P. , Wang Zhendi , Yang Chun , Landriault Mike 
Published: October 2011

AbstractA method based on the combination of solid‐phase extraction (SPE) with gas chromatography–mass spectrometry (GC/MS) for detailed chemical fingerprinting of biodiesel/petrodiesel blends was developed in the present study. Forensic identification, commonly referred to as chemical fingerprinting, is based on the relative distributions of individual aliphatic hydrocarbons, aromatic hydrocarbons, fatty acid alkyl esters, and free sterols. Fractionation of fuel samples is optimized for the separation of fatty acid esters and free sterols from petroleum hydrocarbons into four fractions: aliphatic, aromatic, fatty acid ester, and polar components. The final recoveries of aliphatic and aromatic hydrocarbons were determined to be in the range of 65–103%, 73–105% for FAMEs, and 78–103% for free sterols in the polar fraction. Excellent separation with negligible crossover of components with different polarities between fractions was observed. Quantitative analysis of blend levels and individual chemical distribution were achieved. The method has great potential for the identification of biodiesel in diesel fuel blends and could form the basis of a method for characterization of biodiesel‐contaminated environmental samples.
Fast dynamic contrast‐enhanced lung MR imaging using k–t BLAST: A spatiotemporal perspective
Authors: Hsu Jia‐Shuo , Tsai Shang‐Yuei , Wu Ming‐Ting , Chung Hsiao‐Wen , Lin Yi‐Ru 
Published: October 2011

AbstractDynamic contrast‐enhanced MR imaging has long been an attractive alternative to measure pulmonary perfusion as it offers simultaneous acquisition of high‐resolution anatomical images and various functional information without exposing to ionizing radiation. As higher temporal resolution in addition to simultaneous acquisition of more slices from different positions favors more precise diagnosis, rapid acquisition of multiple images during bolus contrast administration remains essential to pulmonary perfusion imaging. Nevertheless, the branching morphology together with asynchronization of contrast‐enhanced pulmonary perfusion scattered among distinct blood vessels imposes difficulties to faster imaging. This work demonstrates that k–t broad‐use linear acquisition speed‐up technique (k–t BLAST), having substantial performance on accelerating cardiac cine imaging, can be applied to accelerate dynamic contrast‐enhanced lung imaging up to a factor of 5 with errors less than 6% on five healthy subjects and less than 10% on 13 patients, respectively, in the overall signal intensity. Perfusion parameter estimates show somewhat less errors than those in overall signal intensity. Results from healthy subjects and two groups of patients with various diseases show high consistency between fully sampled datasets and their accelerated counterparts. These suggest feasibility of accelerated contrast‐enhanced lung images in clinical examinations and potential of extending k–t BLAST into related applications. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
Numerical integration of a pressure‐dependent, non‐linear kinematic hardening constitutive model for large strain cyclic plasticity of metals
Authors: Panteghini Andrea , Genna Francesco 
Published: October 2011

SUMMARYA Gurson‐based constitutive model is presented, which includes non‐linear mixed isotropic–kinematic hardening and creep, and allows the analysis of problems involving arbitrarily large plastic strains. This model was developed with the main objective of allowing, on the basis of a single set of material parameters, the numerical simulation of all the main features of cold metal forming processes, which usually imply severe loading–unloading cycles with very large plastic strains, difficult to be correctly reproduced numerically. A suitable integration scheme of the rate equations is described and implemented into a finite element code. The results obtained are compared with some reference experimental ones; an application of the model for the simulation of wire drawing processes is also presented. Copyright © 2011 John Wiley & Sons, Ltd.