bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biophysical characterization of polymyxin b interaction with LPS aggregates and membrane model systems
Authors: Domingues Marco M. , Inácio Rita G. , Raimundo José M. , Martins Miguel , Castanho Miguel A. R. B. , Santos Nuno C. 
Published: May 2012

AbstractAntibiotic resistance is an increasingly severe health problem. Antimicrobial peptides (AMPs) are being developed in order to overcome this problem, due to their lower bacterial resistance. Polymyxin B is an AMP with bactericidal effect on Gram‐negative bacteria due to its high affinity for lipopolysaccharide (LPS). The objective of this work was to unravel the polymyxin B mechanisms of LPS neutralization and bactericidal activity. Using dynamic light scattering, it was observed that polymyxin B induces LPS aggregation in a concentration‐dependent manner. The peptide increases the surface charge of LPS and membrane model systems, as revealed by zeta‐potential measurements. The higher zeta‐potential variations were detected in the presence of the negatively charged POPG membranes. This higher interaction with negatively charged membranes, made of POPG, was followed at higher peptide concentration by membrane permeabilization. Also, for zwitterionic POPC membranes a higher membrane leakage was detected. The peptide promotion of LPS aggregation may be related with the clearance of LPS from the bloodstream, eventually by facilitating macrophage phagocytosis and/or blocking the binding of LPS to its receptor. Our data indicate that polymyxin B mechanism of action at the molecular level involves a first step of electrostatic approach toward LPS; then, it may be internalized and bind to the bacterial phosphatidylglycerol‐rich membrane leaflets, inducing leakage at higher peptide concentrations. © 2012 Wiley Periodicals, Inc.Biopolymers (Pept Sci) 98: 338‐344, 2012.
Purification of recombinant protein by cold‐coacervation of fusion constructs incorporating resilin‐inspired polypeptides
Authors: Lyons Russell E. , Elvin Christopher M. , Taylor Karin , Lekieffre Nicolas , Ramshaw John A.M. 
Published: May 2012

AbstractPolypeptides containing between 4 and 32 repeats of a resilin‐inspired sequence AQTPSSYGAP, derived from the mosquito Anopheles gambiae, have been used as tags on recombinant fusion proteins. These repeating polypeptides were inspired by the repeating structures that are found in resilins and sequence‐related proteins from various insects. Unexpectedly, an aqueous solution of a recombinant resilin protein displays an upper critical solution temperature (cold‐coacervation) when held on ice, leading to a separation into a protein rich phase, typically exceeding 200 mg/mL, and a protein‐poor phase. We show that purification of recombinant proteins by cold‐coacervation can be performed when engineered as a fusion partner to a resilin‐inspired repeat sequence. In this study, we demonstrate the process by the recombinant expression and purification of enhanced Green fluorescent protein (EGFP) in E. coli. This facile purification system can produce high purity, concentrated protein solutions without the need for affinity chromatography or other time‐consuming or expensive purification steps, and that it can be used with other bulk purification steps such as low concentration ammonium sulfate precipitation. Protein purification by cold‐coacervation also minimizes the exposure of the target protein to enhanced proteolysis at higher temperature. Biotechnol. Bioeng. 2012; 109: 2947–2954. © 2012 Wiley Periodicals, Inc.
Spouting characteristics of spf wood pellets
Authors: Haddou J. V. H. , Ellis N. , Bi X. , Epstein N. 
Published: May 2012

AbstractThe spouting characteristics with ambient air of cylindrical wood pellets, 6.5 mm in diameter and 11.1 ± 4.1 mm long, were investigated using a transparent 152.4‐mm diameter semi‐circular cone‐based cylindrical column. Despite the previously unexplored shape of the pellets in the spouted bed mode, the measured minimum spouting velocities at different bed heights, the maximum spoutable bed height and the mean spout diameter above the conical base were all well represented by equations from the literature developed mainly for more rounded particles. Pellet attrition was found to be severe, so that the possible torrefaction of the pellets by the spouting technique without sacrifice of their integrity appears to be unlikely. © 2012 Canadian Society for Chemical Engineering
Numerical simulation of a pitched‐blade turbine stirred tank with mirror fluid method
Authors: Wang Tao , Cheng Jingcai , Li Xiangyang , Yang Chao , Mao Zai‐Sha 
Published: May 2012

AbstractMirror fluid method [Yang and Mao, Phys. Rev. 2005; E 71:036704] combined with local grid refinement is proposed to deal with the numerical simulation of turbulent flow in a pitched‐blade turbine stirred tank. By such a novel method, the domain occupied by the impeller is assigned suitable flow parameters explicitly by the mirror relation, so that the correct shear and normal forces on the fluid side of an interface segment is eventually guaranteed. Satisfactory agreement between our predictions and the reported experimental data is achieved both in single‐phase baffled or unbaffled stirred tanks and solid–liquid two‐phase systems. © 2012 Canadian Society for Chemical Engineering
Effect of particle size of magnesium silicate filler on physical properties of paper
Authors: Chauhan Vipul Singh , Bhardwaj Nishi Kant , Chakrabarti Swapan Kumar 
Published: May 2012

AbstractFillers are essential component of printing papers to increase the opacity, brightness, and to improve formation and printing properties. As a very little work has been reported so far on magnesium silicate (talc), the study was conducted with the filler of different particle size for papermaking. The sheets were made in the laboratory with refined mixed hardwood chemical pulp with five grades of talc, ground calcium carbonate (GCC) and precipitated calcium carbonate (PCC) fillers with 15–24% ash level. Apparent density along with tensile, burst, tear index, Z‐direction tensile strength (ZDTS) and bending stiffness index were evaluated for talc filled sheets, and compared with GCC and PCC. Physical strength properties of talc filled sheets were decreased at a faster rate on increasing filler loading in paper and decreasing the particle size of the filler. With same type of filler its particle size determines the physical properties of paper. The postulate was not found to be valid for all the three varieties of fillers viz., talc, PCC and GCC. Shape and geometry of the PCC and GCC fillers determine the individual property. © 2012 Canadian Society for Chemical Engineering
Birth of neural progenitors during the embryonic period of sexual differentiation in the Japanese quail brain
Authors: Bardet Sylvia M. , Mouriec Karen , Balthazart Jacques 
Published: May 2012

AbstractSeveral brain areas in the diencephalon are involved in the activation and expression of sexual behavior, including in quail the medial preoptic nucleus (POM). However, the ontogeny of these diencephalic brain nuclei has not to this date been examined in detail. We investigated the ontogeny of POM and other steroid‐sensitive brain regions by injecting quail eggs with 5‐bromo‐2‐deoxyuridine (BrdU) at various stages between embryonic day (E)3 and E16 and killing animals at postnatal (PN) days 3 or 56. In the POM, large numbers of BrdU‐positive cells were observed in subjects injected from E3–E10, the numbers of these cells was intermediate in birds injected on E12, and most cells were postmitotic in both sexes on E14–E16. Injections on E3–E4 labeled large numbers of Hu‐positive cells in POM. In contrast, injections performed at a later stage labeled cells that do not express aromatase nor neuronal markers such as Hu or NeuN in the POM and other steroid‐sensitive nuclei and thus do not have a neuronal phenotype in these locations, contrary to what is observed in the telencephalon and cerebellum. No evidence could also be collected to demonstrate that these cells have a glial nature. Converging data, including the facts that these cells divide in the brain mantle and express proliferating cell nuclear antigen (PCNA), a cell cycling marker, indicate that cells labeled by BrdU during the second half of embryonic life are slow‐cycling progenitors born and residing in the brain mantle. Future research should now identify their functional significance. J. Comp. Neurol. 520:4226–4253, 2012. © 2012 Wiley Periodicals, Inc.
Cogset: a high performance MapReduce engine
Authors: Valvåg S.V. , Johansen Dag , Kvalnes Åge 
Published: May 2012

SUMMARYCogset is a generic and efficient engine for reliable storage and parallel processing of distributed data sets. It supports a number of high‐level programming interfaces, including a MapReduce interface compatible with Hadoop. In this paper, we present Cogset's architecture and evaluate its performance as a MapReduce engine, comparing it with Hadoop. Our results show that Cogset generally outperforms Hadoop by a significant margin. We investigate the underlying causes of this difference in performance and demonstrate some relatively minor modifications that markedly improve Hadoop's performance, closing some of the gap. Copyright © 2012 John Wiley & Sons, Ltd.
Solid‐State Electrochemiluminescence of F‐doped SnO2 Nanocrystals and Its Sensing Application
Authors: Gao Bu‐Hong , Ding Shou‐Nian , Li Qian‐Qian , Shan Dan , Sun Yue‐Ming , Cosnier Serge 
Published: May 2012

AbstractElectrochemiluminescence (ECL) behaviors and mechanisms of fluorine‐doped tin oxide (F‐SnO2) semiconductor nanocrystals (NCs) were firstly investigated in both of nonaqueous and aqueous solutions via potential scanning or pulsing. Furthermore, the ECL of F‐SnO2 was applied successfully to detect dopamine based on the quenching effect.
Rapid GC‐FID quantification technique without authentic samples using predicted response factors
Authors: Tissot E. , Rochat S. , Debonneville C. , Chaintreau A. 
Published: May 2012

ABSTRACTBecause a flame ionization detector (FID) is based on the combustion of analytes, we have previously shown that a good correlation exists between the relative response factors (RRFs) and the combustion enthalpies. The latter can themselves be predicted by ab initio calculation, or directly from the molecular formula. As a consequence, the RRFs can be simulated with good accuracy for all volatile constituents of flavours and fragrances. The technique is exemplified here with several applications in the field of flavours and fragrances. The composition of complex mixtures by full internal standardization is very time consuming. This task can be greatly shortened with satisfactory accuracy if predicted RRFs are used instead of the inaccurate semi‐quantification (all RRFs = 1). Non‐commercially available compounds normally require re‐synthesis to determine their RRFs. This time‐consuming step can be avoided and the compounds well quantified by using predicted RRFs. In addition, with unstable standards, measuring their RRFs or purities is impossible, whereas this issue is overcome with the present technique. We herein report the successful testing of the predicted RRFs in comprehensive GC×GC‐FID. Copyright © 2012 John Wiley & Sons, Ltd.
Difference infiltrometer: a method to measure temporally variable infiltration rates during rainstorms
Authors: Moody John A. , Ebel Brian A. 
Published: May 2012

AbstractWe developed a difference infiltrometer to measure time series of non‐steady infiltration rates during rainstorms at the point scale. The infiltrometer uses two, tipping bucket rain gages. One gage measures rainfall onto, and the other measures runoff from, a small circular plot about 0.5‐m in diameter. The small size allows the infiltration rate to be computed as the difference of the cumulative rainfall and cumulative runoff without having to route water through a large plot. Difference infiltrometers were deployed in an area burned by the 2010 Fourmile Canyon Fire near Boulder, Colorado, USA, and data were collected during the summer of 2011. The difference infiltrometer demonstrated the capability to capture different magnitudes of infiltration rates and temporal variability associated with convective (high intensity, short duration) and cyclonic (low intensity, long duration) rainstorms. Data from the difference infiltrometer were used to estimate saturated hydraulic conductivity of soil affected by the heat from a wildfire. The difference infiltrometer is portable and can be deployed in rugged, steep terrain and does not require the transport of water, as many rainfall simulators require, because it uses natural rainfall. It can be used to assess infiltration models, determine runoff coefficients, identify rainfall depth or rainfall intensity thresholds to initiate runoff, estimate parameters for infiltration models, and compare remediation treatments on disturbed landscapes. The difference infiltrometer can be linked with other types of soil monitoring equipment in long‐term studies for detecting temporal and spatial variability at multiple time scales and in nested designs where it can be linked to hillslope and basin‐scale runoff responses. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.
Saracatinib (AZD0530) is a potent modulator of ABCB1‐mediated multidrug resistance in vitro and in vivo
Authors: Liu Ke‐Jun , He Jie‐Hua , Su Xiao‐Dong , Sim Hong‐May , Xie Jing‐Dun , Chen Xing‐Gui , Wang Fang , Liang Yong‐Ju , Singh Satyakam , Sodani Kamlesh , Talele Tanaji T. , Ambudkar Suresh V. , Chen Zhe‐Sheng , Wu Hai‐Ying , Fu Li‐Wu 
Published: May 2012

AbstractSaracatinib, a highly selective, dual Src/Abl kinase inhibitor, is currently in a Phase II clinical trial for the treatment of ovarian cancer. In our study, we investigated the effect of saracatinib on the reversal of multidrug resistance (MDR) induced by ATP‐binding cassette (ABC) transporters in vitro and in vivo. Our results showed that saracatinib significantly enhanced the cytotoxicity of ABCB1 substrate drugs in ABCB1 overexpressing HeLa/v200, MCF‐7/adr and HEK293/ABCB1 cells, an effect that was stronger than that of gefitinib, whereas it had no effect on the cytotoxicity of the substrates in ABCC1 overexpressing HL‐60/adr cells and its parental sensitive cells. Additionally, saracatinib significantly increased the doxorubicin (Dox) and Rho 123 accumulation in HeLa/v200 and MCF‐7/adr cells, whereas it had no effect on HeLa and MCF‐7 cells. Furthermore, saracatinib stimulated the ATPase activity and inhibited photolabeling of ABCB1 with [125I]‐iodoarylazidoprazosin in a concentration‐dependent manner. In addition, the homology modeling predicted the binding conformation of saracatinib within the large hydrophobic drug‐binding cavity of human ABCB1. However, neither the expression level of ABCB1 nor the phosphorylation level of Akt was altered at the reversal concentrations of saracatinib. Importantly, saracatinib significantly enhanced the effect of paclitaxel against ABCB1‐overexpressing HeLa/v200 cancer cell xenografts in nude mice. In conclusion, saracatinib reverses ABCB1‐mediated MDR in vitro and in vivo by directly inhibiting ABCB1 transport function, without altering ABCB1 expression or AKT phosphorylation. These findings may be helpful to attenuate the effect of MDR by combining saracatinib with other chemotherapeutic drugs in the clinic.
EUROGIN 2011 roadmap on prevention and treatment of HPV‐related disease
Authors: Arbyn Marc , de Sanjosé Silvia , Saraiya Mona , Sideri Mario , Palefsky Joel , Lacey Charles , Gillison Maura , Bruni Laia , Ronco Guglielmo , Wentzensen Nicolas , Brotherton Julia , Qiao You‐Lin , Denny Lynnette , Bornstein Jacob , Abramowitz Laurent , Giuliano Anna , Tommasino Massimo , Monsonego Joseph 
Published: May 2012

AbstractThe EUROGIN 2011 roadmap reviews the current burden of human papillomavirus (HPV)‐related morbidity, as well as the evidence and potential practice recommendations regarding primary and secondary prevention and treatment of cancers and other disease associated with HPV infection. HPV infection causes ∼600,000 cases of cancer of the cervix, vulva, vagina, anus and oropharynx annually, as well as benign diseases such as genital warts and recurrent respiratory papillomatosis. Whereas the incidence of cervical cancer has been decreasing over recent decades, the incidence of anal and oropharyngeal carcinoma, for which there are no effective screening programs, has been rising over the last couple of decades. Randomized trials have demonstrated improved efficacy of HPV‐based compared to cytology‐based cervical cancer screening. Defining the best algorithms to triage HPV‐positive women, age ranges and screening intervals are priorities for pooled analyses and further research, whereas feasibility questions can be addressed through screening programs. HPV vaccination will reduce the burden of cervical precancer and probably also of invasive cervical and other HPV‐related disease in women. Recent trials demonstrated that prophylactic vaccination also protects against anogenital HPV infection, anogenital intraepithelial lesions and warts associated with vaccine types, in males; and anal HPV infection and anal intraepithelial neoplasia in MSM. HPV‐related oropharyngeal cancer could be treated less aggressively because of better survival compared to cancers of the oropharynx unrelated to HPV. Key findings in the field of cervical cancer prevention should now be translated in cost‐effective strategies, following an organized approach integrating primary and secondary prevention, according to scientific evidence but adapted to the local situation with particular attention to regions with the highest burden of disease.
Paclitaxel‐induced neuropathic pain is age dependent and devolves on glial response
Authors: Ruiz‐Medina J. , Baulies A. , Bura S.A. , Valverde O. 
Published: May 2012

AbstractBackgroundPaclitaxel is an antimitotic antitumour drug highly effective against a broad range of cancers considered refractory to conventional chemotherapy. One of the main serious side effects of paclitaxel treatment is the induction of peripheral neuropathic pain that often diminishes the patient's quality of life. In this study, we evaluated the severity of the neuropathy induced by paclitaxel and the inflammatory reaction in the dorsal horn of the spinal cord in young, adult and aged male CD1 mice.MethodHyperalgesia to noxious thermal stimulus and allodynia to non‐noxious mechanical stimulus were evaluated using the plantar test and the von Frey filament model, respectively. Spinal cord microglia and astrocytes expression was assessed using Iba1 and glial fibrillary acidic protein immunofluorescence staining, respectively.ResultsAll groups of mice showed a higher nociceptive reaction to thermal noxious (hyperalgesia) and mechanical non‐noxious (allodynia) stimuli after paclitaxel treatment. However, these signs of neuropathy were enhanced in young mice followed by aged animals. Additionally, paclitaxel evoked a marked microglial and astrocytic response in the spinal cord of young and aged mice, whereas this enhanced reactivity was less important in adult mice. Indeed, the most severe glial activation observed in juvenile animals correlated well with major signs of neuropathy in this group of age.ConclusionOur results demonstrate that paclitaxel‐induced neuropathy in mice is an age‐dependent phenomenon whose severity devolves on glial response.
Mass transfer trends occurring in engineered ex vivo tissue scaffolds
Authors: Moore Marc , Sarntinoranont Malisa , McFetridge Peter 
Published: May 2012

AbstractIn vivo the vasculature provides an effective delivery system for cellular nutrients; however, artificial scaffolds have no such mechanism, and the ensuing limitations in mass transfer result in limited regeneration. In these investigations, the regional mass transfer properties that occur through a model scaffold derived from the human umbilical vein (HUV) were assessed. Our aim was to define the heterogeneous behavior associated with these regional variations, and to establish if different decellularization technologies can modulate transport conditions to improve microenvironmental conditions that enhance cell integration. The effect of three decellularization methods [Triton X‐100 (TX100), sodium dodecyl sulfate (SDS), and acetone/ethanol (ACE/EtOH)] on mass transfer, cellular migration, proliferation, and metabolic activity were assessed. Results show that regional variation in tissue structure and composition significantly affects both mass transfer and cell function. ACE/EtOH decellularization was shown to increase albumin mass flux through the intima and proximate‐medial region (0–250 μm) when compared with sections decellularized with TX100 or SDS; although, mass flux remained constant over all regions of the full tissue thickness when using TX100. Scaffolds decellularized with TX100 were shown to promote cell migration up to 146% further relative to SDS decellularized samples. These results show that depending on scaffold derivation and expectations for cellular integration, specificities of the decellularization chemistry affect the scaffold molecular architecture resulting in variable effects on mass transfer and cellular response. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Endothelial cell attachment and shear response on biomimetic polymer‐coated vascular grafts
Authors: Dudash Lynn A. , Kligman Faina , Sarett Samantha M. , Kottke‐Marchant Kandice , Marchant Roger E. 
Published: May 2012

AbstractEndothelial cell (EC) adhesion, shear retention, morphology, and hemostatic gene expression on fibronectin (FN) and RGD fluorosurfactant polymer (FSP)‐coated expanded polytetrafluoroethylene grafts were investigated using an in vitro perfusion system. ECs were sodded on both types of grafts and exposed to 8 dyn/cm2 of shear stress. After 24 h, the EC retention on RGD‐FSP‐coated grafts was 59 ± 14%, which is statistically higher than the 36 ± 11% retention measured on FN grafts (p < 0.02). Additionally, ECs on RGD‐FSP exhibited a more spread morphology and oriented in the direction of shear stress, as demonstrated by actin fiber staining. This spread morphology has been observed earlier in cells that are adapting to shear stress. Real‐time PCR for vascular cell adhesion molecule 1, tissue factor, tissue plasminogen activator, and inducible nitric oxide synthase indicated that the RGD‐FSP material did not activate the cells and that shear stress appears to induce a more vasoprotective phenotype, as shown by a significant decrease in VCAM‐1 expression, compared with sodded grafts. RGD‐FSP‐coating allows for a cell layer that is more resistant to physiological shear stress, as shown by the increased cell retention over FN. This shear stable EC layer is necessary for in vivo endothelialization of the graft material, which shows promise to increase the patency of synthetic small diameter vascular grafts. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.