9,776 research outputs found
Mean Field Effects In The Quark-Gluon Plasma
A transport model based on the mean free path approach for an interacting
meson system at finite temperatures is discussed. A transition to a quark gluon
plasma is included within the framework of the MIT bag model. The results
obtained compare very well with Lattice QCD calculations when we include a mean
field in the QGP phase due to the Debye color screening. In particular the
cross over to the QGP at about 175 MeV temperature is nicely reproduced. We
also discuss a possible scenario for hadronization which is especially
important for temperatures below the QGP phase transition
Dynamic reliability analysis of corroded pipeline using Bayesian Network
Funding Information: The authors would like to express appreciation for the support of the sponsor Universiti Malaysia Pahang Internal Grant [RDU1703169].Peer reviewedPublisher PD
Cardiovascular magnetic resonance reference ranges for the heart and aorta in Chinese at 3T.
Cardiovascular magnetic resonance (CMR) reference ranges have not been well established in Chinese. Here we determined normal cardiac and aortic reference ranges in healthy Singaporean Chinese and investigated how these data might affect clinical interpretation of CMR scans.In 180 healthy Singaporean Chinese (20 to 69 years old; males, n = 91), comprehensive cardiac assessment was performed using the steady state free precision technique (3T Ingenia, Philips) and images were analysed by two independent observers (CMR42, Circle Cardiovascular Imaging). Measurements were internally validated using standardized approaches: left ventricular mass (LVM) was measured in diastole and systole (with and without papillary muscles) and stroke volumes were compared in both ventricles. All reference ranges were stratified by sex and age; and indeterminate/borderline regions were defined statistically at the limits of the normal reference ranges. Results were compared with clinical measurements reported in the same individuals.LVM was equivalent in both phases (mean difference 3.0 ± 2.5 g; P = 0.22) and stroke volumes were not significantly different in the left and right ventricles (P = 0.91). Compared to females, males had larger left and right ventricular volumes (P 0.05 for all measures). In both sexes, age correlated negatively with left and right ventricular volumes; and positively with aortic sinus and sinotubular junction diameters (P < 0.0001 for all). There was excellent agreement in indexed stroke volumes in the left and right ventricles (0.1±5.7 mL/m2, 0.7±6.2 mL/m2, respectively), LVM (0.6±6.4 g/m2), atrial sizes and aortic root dimensions between values reported in clinical reports and our measured reference ranges.Comprehensive sex and age-corrected CMR reference ranges at 3T have been established in Singaporean Chinese. This is an important step for clinical practice and research studies of the heart and aorta in Asia
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Mechanical properties of zeolitic metal-organic frameworks: Mechanically flexible topologies and stabilization against structural collapse
We report the low elastic modulus of a zeolitic MOF, along with stabilization against structural collapse by filling with solvent.This is the author-accepted manuscript. It is under embargo for 12 months after publication. The final version of this article is published by RSC in CrystEngComm and can be found here: http://dx.doi.org/10.1039/c4ce02145
Cytoprotective and antioxidant effects of the methanol extract of Eremomastax Speciosa in rats
Background: Ethno-botanical information shows that Eremomastax speciosa is used in the traditional management of various stomach complaints including gastro-duodenal ulcers.Materials and Methods: In this study, we tested the cytoprotective potential of the whole plant methanol extract (100-200 mg/kg, p.o), against HCl/ethanol, absolute ethanol, cold/restraint stress rats, and pylorus legated rats pre-treated with indomethacin. The effects of the extract on gastric lesion inhibition, the volume of gastric juice, gastric pH, gastric acid output, mucus production and gastric peptic activity were recorded. Oxidative stress parameters were measured in blood and gastric tissue samples obtained from the animals in all the models tested.Results: The extract significantly (p<0.05), reduced the formation of cold/restraint ulcers by (31-60%, inhibition), completely inhibited (100%) the formation of lesions induced by HCl/ethanol at the highest dose, but was less effective against absolute ethanol (22-46% inhibition). The extract (200 mg/kg), significantly reduced lesion formation (P<0.01), gastric acidity (P<0.01), and volume of gastric secretions (P<0.05), in the indomethacin/pylorus ligation model, and did not affect the activity of pepsin in gastric juice. Blood concentrations of antioxidant enzymes (catalase, SOD and GSH), increased significantly and MDA concentrations decreased in all models tested.Conclusion: Cytoprotection by E. speciosa methanol extract was attributed to its ability to reduce acid secretion, and to enhance mucosal defence and in vivo antioxidant status.Key words: Eremomastax speciosa, cytoprotection, gastric ulcers, antioxidant statu
Microbial predation accelerates granulation and modulates microbial community composition.
BackgroundBacterial communities are responsible for biological nutrient removal and flocculation in engineered systems such as activated floccular sludge. Predators such as bacteriophage and protozoa exert significant predation pressure and cause bacterial mortality within these communities. However, the roles of bacteriophage and protozoan predation in impacting granulation process remain limited. Recent studies hypothesised that protozoa, particularly sessile ciliates, could have an important role in granulation as these ciliates were often observed in high abundance on surfaces of granules. Bacteriophages were hypothesized to contribute to granular stability through bacteriophage-mediated extracellular DNA release by lysing bacterial cells. This current study investigated the bacteriophage and protozoan communities throughout the granulation process. In addition, the importance of protozoan predation during granulation was also determined through chemical killing of protozoa in the floccular sludge.ResultsFour independent bioreactors seeded with activated floccular sludge were operated for aerobic granulation for 11 weeks. Changes in the phage, protozoa and bacterial communities were characterized throughout the granulation process. The filamentous phage, Inoviridae, increased in abundance at the initiation phase of granulation. However, the abundance shifted towards lytic phages during the maturation phase. In contrast, the abundance and diversity of protozoa decreased initially, possibly due to the reduction in settling time and subsequent washout. Upon the formation of granules, ciliated protozoa from the class Oligohymenophorea were the dominant group of protozoa based on metacommunity analysis. These protozoa had a strong, positive-correlation with the initial formation of compact aggregates prior to granule development. Furthermore, chemical inhibition of these ciliates in the floccular sludge delayed the initiation of granule formation. Analysis of the bacterial communities in the thiram treated sludge demonstrated that the recovery of 'Candidatus Accumulibacter' was positively correlated with the formation of compact aggregates and granules.ConclusionPredation by bacteriophage and protozoa were positively correlated with the formation of aerobic granules. Increases in Inoviridae abundance suggested that filamentous phages may promote the structural formation of granules. Initiation of granules formation was delayed due to an absence of protozoa after chemical treatment. The presence of 'Candidatus Accumulibacter' was necessary for the formation of granules in the absence of protozoa
The usage of sexual internet media and sexual behaviour among sexually experienced adolescents in Malaysia: Sexual intention as a mediator
© 2018 Universiti Putra Malaysia Press. This study examines the relationships between the use of sexually explicit material, sexual intention, and sexual behaviour in a sample of 189 sexually experienced adolescents (aged 16-17) in Malaysia. Additionally, this study investigates the mediating role of sexual intention on the relationship between the use of Sexual Explicit Internet Media (SEIM) and sexual behaviour. A self-administered questionnaire focusing on the use of SEIM scale, Youth Pre-coital and Sexual Intentions Scale, and Sexual Behaviour Assessment measured adolescents' use of SEIM, sexual intention, and sexual behaviour. The results demonstrate that the use of SEIM positively correlates with adolescents' sexual intention and sexual behaviour. Increasing engagements in sexually-related behaviour reveal an increase in sexual intentions. Findings also denote that higher exposure to SEIM promotes sexual intention, which in turn increases engagement in sexually-related behaviour. In the attempt to control sexual arousal among adolescents, prevention and intervention programmes which deal with sexuality should consider the role of Internet media and the development of healthy cognitive processes
Engineering a light-responsive, quorum quenching biofilm to mitigate biofouling on water purification membranes
Copyright © 2018 The Authors. Quorum quenching (QQ) has been reported to be a promising approach for membrane biofouling control. Entrapment of QQ bacteria in porous matrices is required to retain them in continuously operated membrane processes and to prevent uncontrollable biofilm formation by the QQ bacteria on membrane surfaces. It would be more desirable if the formation and dispersal of biofilms by QQ bacteria could be controlled so that the QQ bacterial cells are self-immobilized, but the QQ biofilm itself still does not compromise membrane performance. In this study, we engineered a QQ bacterial biofilm whose growth and dispersal can be modulated by light through a dichromatic, optogenetic c-di-GMP gene circuit in which the bacterial cells sense near-infrared (NIR) light and blue light to adjust its biofilm formation by regulating the c-di-GMP level. We also demonstrated the potential application of the engineered light-responsive QQ biofilm in mitigating biofouling of water purification forward osmosis membranes. The c-di-GMP–targeted optogenetic approach for controllable biofilm development we have demonstrated here should prove widely applicable for designing other controllable biofilm-enabled applications such as biofilm-based biocatalysis
Kinetic description of hadron-hadron collisions
A transport model based on the mean free path approach to describe pp
collisions is proposed. We assume that hadrons can be treated as bags of
partons similarly to the MIT bag model. When the energy density in the
collision is higher than a critical value, the bags break and partons are
liberated. The partons expand and can make coalescence to form new hadrons. The
results obtained compare very well with available data and some prediction for
higher energies collisions are discussed. Based on the model we suggest that a
QGP could already be formed in the pp collisions at high energies
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