bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of two phase flow in liquid oxygen hybrid journal bearings for rocket engine turbopumps
Authors: Guoyuan Zhang , Xiu-Tian Yan 
Published: February 2014

Purpose– A hybrid bearing of advanced cryogenic rocket engine turbopump is designed. For cryogenic fluid propellants (such as liquid oxygen) as the lubrication of bearing, bearings operating close to liquid-vapor region (near the critical point or slightly sub-cooled) are likely to develop a two phase flow region. The paper aims to discuss these issues.Design/methodology/approach– In this paper, an all liquid, liquid-vapor mixture, and all vapor, i.e. a continuous vaporization bulk flow model of density and viscosity for mixture fluid, is presented, and the general Reynolds equation and energy equation with two phase flow as lubricants is solved. The static and dynamic performance of a 50-mm-radius hybrid bearing are obtained under 20,000 rpm speed and 10 MPa supply pressure.Findings– The results show that the variations of performance of bearing operating under cryogenic liquid oxygen are not bounded by the all liquid and all vapor cases in the liquid-vapor mixture range. There behaviours are attributed to the large change in the compressibility character of the flow.Research limitations/implications– For validating the correctness of analytical model, an experimental study on the liquid-vapor nitrogen mixture lubricated hybrid journal bearings is being carried out where low-viscosity nitrogen was selected as the lubricant for the sake of safety. Soon after, the authors will discuss the results and publish them in the new papers.Originality/value– An all liquid, liquid-vapor mixture, and all vapor, i.e. a continuous vaporization bulk flow model of density and viscosity for mixture fluid, is presented. The static and dynamic performance of hybrid bearings with two phase flow as lubricants are obtained.
Predictors of malaria infection in a wild bird population: landscape‐level analyses reveal climatic and anthropogenic factors
Authors: Gonzalez‐Quevedo Catalina , Davies Richard G. , Richardson David S. 
Published: February 2014

SummaryHow the environment influences the transmission and prevalence of disease in a population of hosts is a key aspect of disease ecology. The role that environmental factors play in host–pathogen systems has been well studied at large scales, that is, differences in pathogen pressures among separate populations of hosts or across land masses. However, despite considerable understanding of how environmental conditions vary at fine spatial scales, the effect of these parameters on host–pathogen dynamics at such scales has been largely overlooked.Here, we used a combination of molecular screening andGIS‐based analysis to investigate how environmental factors determine the distribution of malaria across the landscape in a population of Berthelot's pipit (Anthus berthelotii, Bolle 1862) on the island of Tenerife (Canary Islands, Spain) using spatially explicit models that account for spatial autocorrelation.Minimum temperature of the coldest month was found to be the most important predictor of malaria infection at the landscape scale across this population. Additionally, anthropogenic factors such as distance to artificial water reservoirs and distance to poultry farms were important predictors of malaria. A model including these factors, and the interaction between distance to artificial water reservoirs and minimum temperature, best explained the distribution of malaria infection in this system.These results suggest that levels of malaria infection in this endemic species may be artificially elevated by the impact of humans.Studies such as the one described here improve our understanding of how environmental factors, and their heterogeneity, affect the distribution of pathogens within wild populations. The results demonstrate the importance of measuring fine‐scale variation – and not just regional effects – to understand how environmental variation can influence wildlife diseases. Such understanding is important for predicting the future spread and impact of disease and may help inform disease management programmes as well as the conservation of specific host species.
The long‐term dynamics of Campylobacter colonizing a free‐range broiler breeder flock: an observational study
Authors: Colles Frances M. , McCarthy Noel D. , Bliss Carly M. , Layton Ruth , Maiden Martin C. J. 
Published: February 2014

SummaryA free‐range broiler breeder flock was studied in order to determine the natural patterns of Campylobacter colonization over a period of 63 weeks. Campylobacter sequence types (STs) were not mutually exclusive and on average colonized only 17.7% of the birds tested at any time. Campylobacter STs typically reached a peak in prevalence upon initial detection in the flock before tailing off, although the ST and antigenic flaA short variable region in combination were stable over a number of months. There was evidence that, with a couple of exceptions, the ecology of C. jejuni and C. coli differed, with the latter forming a more stable population. Despite being free range, no newly colonizing STs were detected over a 6‐week period in autumn and a 10‐week period in winter, towards the end of the study. There was limited evidence that those STs identified among broiler chicken flocks on the same farm site were likely to colonize the breeder flock earlier (R2 0.16, P 0.01). These results suggest that there is natural control of Campylobacter dynamics within a flock which could potentially be exploited in designing new intervention strategies, and that the two different species should perhaps be considered separately.
Elucidation of sevadicin, a novel non‐ribosomal peptide secondary metabolite produced by the honey bee pathogenic bacterium Paenibacillus larvae
Authors: Garcia‐Gonzalez Eva , Müller Sebastian , Ensle Paul , Süssmuth Roderich D. , Genersch Elke 
Published: February 2014

SummaryAmerican foulbrood (AFB) caused by the bee pathogenic bacterium Paenibacillus larvae is the most devastating bacterial disease of honey bees worldwide. From AFB‐dead larvae, pure cultures of P. larvae can normally be cultivated indicating that P. larvae is able to defend its niche against all other bacteria present. Recently, comparative genome analysis within the species P. larvae suggested the presence of gene clusters coding for multi‐enzyme complexes, such as non‐ribosomal peptide synthetases (NRPSs). The products of these enzyme complexes are known to have a wide range of biological activities including antibacterial activities. We here present our results on antibacterial activity exhibited by vegetative P. larvae and the identification and analysis of a novel antibacterially active P. larvae tripeptide (called sevadicin; Sev) produced by a NRPS encoded by a gene cluster found in the genome of P. larvae. Identification of Sev was ultimately achieved by comparing the secretome of wild‐type P. larvae with knockout mutants of P. larvae lacking production of Sev. Subsequent mass spectrometric studies, enantiomer analytics and chemical synthesis revealed the sequence and configuration of the tripeptide, D‐Phe‐D‐ALa‐Trp, which was shown to have antibacterial activity. The relevance of our findings is discussed in respect to host–pathogen interactions.
The Yersinia pestis HmsCDE regulatory system is essential for blockage of the oriental rat flea (Xenopsylla cheopis), a classic plague vector
Authors: Bobrov Alexander G. , Kirillina Olga , Vadyvaloo Viveka , Koestler Benjamin J. , Hinz Angela K. , Mack Dietrich , Waters Christopher M. , Perry Robert D. 
Published: February 2014

SummaryThe second messenger molecule cyclic diguanylate is essential for Yersinia pestis biofilm formation that is important for blockage‐dependent plague transmission from fleas to mammals. Two diguanylate cyclases (DGCs) HmsT and Y3730 (HmsD) are responsible for biofilm formation in vitro and biofilm‐dependent blockage in the oriental rat flea Xenopsylla cheopis respectively. Here, we have identified a tripartite signalling system encoded by the y3729‐y3731 operon that is responsible for regulation of biofilm formation in different environments. We present genetic evidence that a putative inner membrane‐anchored protein with a large periplasmic domain Y3729 (HmsC) inhibits HmsD DGC activity in vitro while an outer membrane Pal‐like putative lipoprotein Y3731 (HmsE) counteracts HmsC to activate HmsD in the gut of X. cheopis. We propose that HmsE is a critical element in the transduction of environmental signal(s) required for HmsD‐dependent biofilm formation.
Quorum sensing positively regulates flagellar motility in pathogenic Vibrio harveyi
Authors: Yang Qian , Defoirdt Tom 
Published: February 2014

SummaryVibrios belonging to the Harveyi clade are among the major pathogens of aquatic organisms. Quorum sensing (QS) is essential for virulence of V. harveyi towards different hosts. However, most virulence factors reported to be controlled by QS to date are negatively regulated by QS, therefore suggesting that their impact on virulence is limited. In this study, we report that QS positively regulates flagellar motility. We found that autoinducer synthase mutants showed significantly lower swimming motility than the wild type, and the swimming motility could be restored by adding synthetic signal molecules. Further, motility of a luxO mutant with inactive QS (LuxO D47E) was significantly lower than that of the wild type and of a luxO mutant with constitutively maximal QS activity (LuxO D47A). Furthermore, we found that the expression of flagellar genes (both early, middle and late genes) was significantly lower in the luxO mutant with inactive QS when compared with wild type and the luxO mutant with maximal QS activity. Motility assays and gene expression also revealed the involvement of the quorum‐sensing master regulator LuxR in the QS regulation of motility. Finally, the motility inhibitor phenamil significantly decreased the virulence of V. harveyi towards gnotobiotic brine shrimp larvae.
Trichodesmium's strategies to alleviate phosphorus limitation in the future acidified oceans
Authors: Spungin Dina , Berman‐Frank Ilana , Levitan Orly 
Published: February 2014

SummaryGlobal warming may exacerbate inorganic nutrient limitation, including phosphorus (P), in the surface‐waters of tropical oceans that are home to extensive blooms of the marine diazotrophic cyanobacterium,Trichodesmium. We examined the combined effects ofPlimitation andpCO2, forecast under ocean acidification scenarios, onTrichodesmium erythraeum IMS101 cultures. We measured nitrogen acquisition, glutamine synthetase activity,Cuptake rates, intracellular Adenosine Triphosphate (ATP) concentration and the pool sizes of related key proteins. Here, we present data supporting the idea that cellular energy re‐allocation enables the higher growth andN2fixation rates detected inTrichodesmiumcultured under highpCO2. This is reflected in altered protein abundance and metabolic pools. Also modified are particulate organic carbon and nitrogen production rates, enzymatic activities, and cellularATPconcentrations. We suggest that adjusting these cellular pathways to changing environmental conditions enablesTrichodesmiumto compensate for lowPavailability and to thrive in acidified oceans. Moreover, elevatedpCO2could provideTrichodesmiumwith a competitive dominance that would extend its niche, particularly inP‐limited regions of the tropical and subtropical oceans.
The fibre‐associated cellulolytic bacterial community in the hindgut of wood‐feeding higher termites (Nasutitermes spp.)
Authors: Mikaelyan Aram , Strassert Jürgen F. H. , Tokuda Gaku , Brune Andreas 
Published: February 2014

SummaryTermites digest lignocellulose with the help of their symbiotic gut microbiota. In the hindgut of evolutionary lower termites, a dense community of cellulolytic flagellates sequesters wood particles from the hindgut content into their digestive vacuoles. In higher termites (family Termitidae), which possess an entirely prokaryotic microbiota, the wood particles are available for bacterial colonization. Substantial particle‐associated cellulase activities have been detected in the hindgut of Nasutitermes species, but the microorganisms responsible for these activities and their potential association with the wood fibres remain to be studied. Here, we used density‐gradient centrifugation to separate wood fibres and adherent bacterial cells from cells freely suspended in the hindgut fluid. In Nasutitermes corniger, the fibre fraction contained 28% of the DNA and 45% of the cellulase activity in the luminal contents (P3 region). Community fingerprinting (terminal restriction fragment length polymorphism) and pyrotag sequencing analysis of the bacterial 16S rRNA genes demonstrated that the wood fibres in the hindgut of both N. corniger and N. takasagoensis are specifically colonized by members of Fibrobacteres, the TG3 phylum, and certain lineages of Spirochaetes characteristic of the gut microbiota of wood‐feeding higher termites. We propose that the loss of flagellates in higher termites provided a new niche for fibre‐associated cellulolytic bacteria.
A Polydrug Intoxication Involving Methoxetamine in a Drugs and Driving Case
Authors: Elian Albert A. , Hackett Jeffery 
Published: February 2014

AbstractMethoxetamine ((RS)2‐(3‐methoxyphenyl)‐2‐(ethylamino)cyclohexanone)) is becoming a drug of interest among practitioners of forensic toxicology. In this case report, we describe the case background, standard field sobriety tests, sampling, and analysis of this drug in a whole blood sample as well as screening methods and analysis from a driver operating under the influence of intoxicating substances. Methoxetamine was isolated from the blood sample using mixed mode solid phase extraction. After elution and evaporation, the residue was dissolved in mobile phase (consisting of acetonitrile and aqueous formic acid) for analysis by liquid chromatography–tandem mass spectrometry (LC–MS/MS) and gas chromatography–mass spectrometry (GC–MS). The case sample was found to contain clonazepam, 7‐aminoclonazepam, carboxy‐THC, Ddphenhydramine, and MDMA. The case sample was found to contain 10 ng/mL of the drug (methoxetamine) in whole blood. The results of this drug analysis and previous analyses are discussed in terms of this driver operating under the influence of drugs.
Endoscopic balloon dilatation for benign esophageal stricture after endoscopic submucosal dissection for early esophageal neoplasms
Authors: Lian Jing Jing , Ma Li Li , Hu Jian Wei , Chen Shi Yao , Qin Wen Zheng , Xu Mei Dong , Zhou Ping Hong , Yao Li Qing 
Published: February 2014

ObjectiveThe aim of this study was to evaluate the safety and efficacy of endoscopic balloon dilatation (EBD) for benign esophageal strictures after ESD for early esophageal neoplasms.MethodsData of 335 patients who were treated with ESD for early esophageal neoplasms from October 2006 to August 2012 were retrospectively reviewed. The characteristics of the patients who underwent EBD for post‐ESD stricture were analyzed.ResultsA total of 117 dilatation procedures were performed in 29 patients with post‐ESD esophageal stricture. The mean number of EBD sessions was 4.0 (range 1–15) and no complications occurred during the procedures. The median follow‐up period for the 29 patients since their last session of EBD was 20 months (range 1–48 months). Of the 28 patients who were followed up for more than 3 months after achieving dysphagia relief, two had recurrent dysphasia and EBD was reintroduced. The treatment success rate was 92.9% (26/28).ConclusionEBD is a safe and effective modality for the treatment of benign esophageal stricture after ESD for early esophageal neoplasms.
Lung function and metabolic syndrome: Findings of National Health and Nutrition Examination Survey 2007–2010 肺功能与代谢综合征：2007–2010全国健康与营养调查研究结果
Authors: Ford Earl S. , Cunningham Timothy J. , Mercado Carla I. 
Published: February 2014

AbstractBackgroundConsiderable uncertainty remains about obstructive lung function (OLF) in adults with metabolic syndrome (MetS). The aim of the present study was to examine pulmonary function status in adults with and without MetS.MethodsWe used data from 3109 participants aged ≥20 years of the National Health and Nutrition Examination Survey 2007–2010. Subjects' MetS status was established on the basis of the 2009 harmonizing definition. Participants received spirometry.ResultsAfter age adjustment, 79.3% (SE 1.1) of participants with MetS had normal lung function, 8.7% (0.9) had restrictive lung function (RLF), 7.1% (0.8) had mild OLF, and 4.8% (0.6) had moderate OLF or worse. Among participants without MetS, these estimates were 78.7% (1.2), 3.9% (0.6), 10.9% (1.1), and 6.4% (0.8), respectively. After multiple adjustment, participants with MetS were more likely to have RLF (adjusted prevalence ratio [aPR] 2.20; 95% confidence interval [CI] 1.67, 2.90) and less likely to have any OLF (aPR 0.73; 95% CI 0.62, 0.86) than those without MetS. Furthermore, participants with MetS had lower mean levels of forced expiratory volume in one second (FEV1), FEV1 % predicted, forced vital capacity (FVC), and FVC % predicted, but a higher FEV1/FVC ratio than participants without MetS. Mean levels of FEV1, FEV1 % predicted, FVC, and FVC % predicted declined significantly, but not the FEV1/FVC ratio, as the number of components increased.ConclusionsCompared with adults without MetS, spirometry is more likely to show a restrictive pattern and less likely to show an obstructive pattern among adults with MetS.
Association between sleep architecture and glucose tolerance in children and adolescents 儿童及青少年的睡眠结构与糖耐量的关系
Authors: Zhu Yin , Li Albert Martin , Au Chun Ting , Kong Alice Pik Shan , Zhang Jihui , Wong Chun Kwok , Chan Juliana Chung Ngor , Wing Yun Kwok 
Published: February 2014

AbstractBackgroundShort sleep duration is a contributing factor for decreased insulin sensitivity and hyperglycemia. Sleep architecture represents a cyclical pattern of sleep that shifts between sleep Stages N1, N2, N3 (slow wave sleep) and Stage R (rapid eye movement sleep). The aim of the present study was to examine the association between sleep architecture and glucose and insulin metabolism in both normal weight and overweight/obese children and adolescents.MethodsA total of 118 subjects participated in the study. Subjects underwent overnight polysomnography (PSG) when the percentage of total sleep time (% TST) spent at each sleep stage was recorded and an oral glucose tolerance test together was performed the next morning. We assessed glucose tolerance, insulin sensitivity and pancreatic β‐cell function using 2‐h glucose levels, the Matsuda index (ISOGTT), and insulin secretion‐sensitivity index‐2 (ISSI‐2), respectively.ResultsAfter adjustment for age, gender, body mass index z‐score, pubertal status, and obstructive apnea hypopnea index, Stage N3 (% TST) was positively associated with ISOGTT, whereas Stage N1 (%TST) exerted an opposite effect on ISOGTT. Higher sleep efficiency and longer TST were independently associated with lower 2‐h glucose levels, higher ISSI‐2 and/or higher ISOGTT.ConclusionsStage N3, sleep efficiency and TST were protective factors in maintaining glucose and insulin homeostasis; however, Stage N1 functioned in the opposite direction.
Stereoscopy in diagnostic radiology and procedure planning: Does stereoscopic assessment of volume‐rendered CT angiograms lead to more accurate characterisation of cerebral aneurysms compared with traditional monoscopic viewing?
Authors: Stewart Nikolas , Lock Gregory , Hopcraft Anthony , Kanesarajah Jeeva , Coucher John 
Published: February 2014

AbstractIntroductionStereoscopic vision is a critical part of the human visual system, conveying more information than two‐dimensional, monoscopic observation alone. This study aimed to quantify the contribution of stereoscopy in assessment of radiographic data, using widely available three‐dimensional (3D)‐capable display monitors by assessing whether stereoscopic viewing improved the characterisation of cerebral aneurysms.MethodsNine radiology registrars were shown 40 different volume‐rendered (VR) models of cerebral computed tomography angiograms (CTAs), each in both monoscopic and stereoscopic format and then asked to record aneurysm characteristics on short multiple‐choice answer sheets. The monitor used was a current model commercially available 3D television. Responses were marked against a gold standard of assessments made by a consultant radiologist, using the original CT planar images on a diagnostic radiology computer workstation.ResultsThe participants' results were fairly homogenous, with most showing no difference in diagnosis using stereoscopic VR models. One participant performed better on the monoscopic VR models. On average, monoscopic VRs achieved a slightly better diagnosis by 2.0%.ConclusionsStereoscopy has a long history, but it has only recently become technically feasible for stored cross‐sectional data to be adequately reformatted and displayed in this format. Scant literature exists to quantify the technology's possible contribution to medical imaging – this study attempts to build on this limited knowledge base and promote discussion within the field. Stereoscopic viewing of images should be further investigated and may well eventually find a permanent place in procedural and diagnostic medical imaging.
Inhibition of Coagulation Factor Xa Improves Myocardial Function During CVB3‐Induced Myocarditis
Authors: Malz Ronny , Weithauser Alice , Tschöpe Carsten , Schultheiss Heinz‐Peter , Rauch Ursula 
Published: February 2014

SummaryIntroductionMyocarditis is induced by coxsackievirus B3 (CVB3). Myocardial inflammation is tied to the activation of coagulation. Coagulation factor (F) Xa, a central player in coagulation, activates matrix metalloproteinases (MMP), which modulate the remodeling.AimsIn this study, we investigated the effects of pharmacological FXa inhibition on myocardial function, inflammation, and remodeling during a CVB3‐induced myocarditis.Methods and ResultsImmune cells and matrix proteins were detected by immunohistochemistry. The expression of cytokines was measured by real‐time PCR and the activity of MMP‐2 by zymography. Left ventricular function was analyzed using microconductance pressure catheter. Treatment with the FXa inhibitor fondaparinux led to an improved left ventricular function in CVB3‐induced mice compared to saline‐treated controls (dPdtmax: fondaparinux 4632 ± 499.6 vs. saline 3131 ± 374.0 [mmHg/s], P = 0.0503; SV: fondaparinux 33.19 ± 4.893 vs. saline 19.32 ± 2.236 [μL], P < 0.118; CO: fondaparinux 15124 ± 2183 vs. saline 8088 ± 1035 [μL/min], P < 0.05). Therapy with fondaparinux reduced the activity of MMP‐2 (fondaparinux 1.208 ± 0.1247 vs. saline 1.565 ± 0.05476, P < 0.05). The collagen type I/III ratio as well as the expression of TIMP‐1 was comparable in both infection groups postinfectionem (p.i.), despite an increased infiltration of macrophages into the hearts of mice treated with fondaparinux 8 days p.i. (CD68+: fondaparinux 494.2 ± 64.73 vs. saline 306.9 ± 43.73 [cells/mm2], P < 0.05). Anti‐inflammatory CD206‐positive M2‐type macrophages were increased in the infected hearts after fondaparinux treatment (CD206+: fondaparinux 182.1 ± 18.18 vs. saline 111.6 ± 21.07 [cells/mm2], P < 0.05), whereas CD80‐positive M1‐type macrophages were comparable in both groups.ConclusionIn conclusion, selective inhibition of FXa improves the left ventricular function during CVB3‐induced myocarditis and seems to be associated with an improved myocardial remodeling.