786 research outputs found
Ising-like dynamical signatures and the end-point of the QCD transition line
An increase in the size of coherent domains in the one component
field theory under the influence of a uniformly changing external magnetic
field near the critical end-point was proposed
recently as an estimate also for the variation of the chiral correlation length
of QCD near its respective hypothetical end point in the
plane. The present detailed numerical investigation of the effective model
suggests that passing by the critical QCD end point with realistic rate of
temperature change will trigger large amplitude oscillations in the temporal
variation of the chiral correlation length. A simple mechanism for producing
this phenomenon is suggested.Comment: 10 pages, RevTeX, 5 figures. Version accepted for publication in PR
Dynamic breakage and fragmentation of brittle single particle of various sizes and strength
2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Specific subsystems of the inferior parietal lobule are associated with hand dysfunction following stroke: A cross-sectional resting-state fMRI study
Aim
The inferior parietal lobule (IPL) plays important roles in reaching and grasping during hand movements, but how reorganizations of IPL subsystems underlie the paretic hand remains unclear. We aimed to explore whether specific IPL subsystems were disrupted and associated with hand performance after chronic stroke.
Methods
In this cross-sectional study, we recruited 65 patients who had chronic subcortical strokes and 40 healthy controls from China. Each participant underwent the Fugl-Meyer Assessment of Hand and Wrist and resting-state fMRI at baseline. We mainly explored the group differences in resting-state effective connectivity (EC) patterns for six IPL subregions in each hemisphere, and we correlated these EC patterns with paretic hand performance across the whole stroke group and stroke subgroups. Moreover, we used receiver operating characteristic curve analysis to distinguish the stroke subgroups with partially (PPH) and completely (CPH) paretic hands.
Results
Stroke patients exhibited abnormal EC patterns with ipsilesional PFt and bilateral PGa, and five sensorimotor-parietal/two parietal–temporal subsystems were positively or negatively correlated with hand performance. Compared with CPH patients, PPH patients exhibited abnormal EC patterns with the contralesional PFop. The PPH patients had one motor-parietal subsystem, while the CPH patients had one sensorimotor-parietal and three parietal-occipital subsystems that were associated with hand performance. Notably, the EC strength from the contralesional PFop to the ipsilesional superior frontal gyrus could distinguish patients with PPH from patients with CPH.
Conclusions
The IPL subsystems manifest specific functional reorganization and are associated with hand dysfunction following chronic stroke.Natural Science Foundation of Zhejiang Province, Grant/Award Number: LGF19H270001; Shanghai Sailing Program, Grant/Award Number: 20YF144510
Oosorption in the Endoparasitoid, Pteromalus puparum
Oosorption is the resorption of oocytes in the ovaries, and is usually induced by environmental stress. It has been demonstrated in some insect species, but overall the mechanisms of oosorption are poorly understood. In this study, the oosorption in the endoparasitic wasp, Pteromalus puparum L. (Hymenoptera: Pteromalidae), was observed in response to starvation. To explore the details of oosorption in P. puparum, both levels of hemolymph vitellogenin and ovarian vitellin were determined using sandwich ELISA. The results indicated that both levels of vitellin and total protein in the ovaries were significantly decreased 48 h after eclosion in starved P. puparum, while those of vitellogenin and total protein in the hemolymph were increased. In addition, observation of the ultrastructure of mature oocytes in the ovarioles revealed changes in yolk protein content. Those protein yolk spheres and lipid yolk spheres that had accumulated in the oocytes, were transferred out of the oocytes of starved females. It was assumed that once oosorption was induced in P. puparum, vitellin in the oocytes was transported outside and released into the hemolymph. This information helps to elucidate a mechanism of oosorption in insects
Finding multiple target optimal intervention in disease-related molecular network
Drugs against multiple targets may overcome the many limitations of single targets and achieve a more effective and safer control of the disease. Numerous high-throughput experiments have been performed in this emerging field. However, systematic identification of multiple drug targets and their best intervention requires knowledge of the underlying disease network and calls for innovative computational methods that exploit the network structure and dynamics. Here, we develop a robust computational algorithm for finding multiple target optimal intervention (MTOI) solutions in a disease network. MTOI identifies potential drug targets and suggests optimal combinations of the target intervention that best restore the network to a normal state, which can be customer designed. We applied MTOI to an inflammation-related network. The well-known side effects of the traditional non-steriodal anti-inflammatory drugs and the recently recalled Vioxx were correctly accounted for in our network model. A number of promising MTOI solutions were found to be both effective and safer
EVIDENCE OF AGB POLLUTION IN GALACTIC GLOBULAR CLUSTERS FROM THE Mg-Al ANTICORRELATIONS OBSERVED BY THE APOGEE SURVEY
We study the formation of multiple populations in globular clusters (GC),
under the hypothesis that stars in the second generation formed from the winds
of intermediate-mass stars, ejected during the asymptotic giant branch (AGB)
phase, possibly diluted with pristine gas, sharing the same chemical
composition of first-generation stars. To this aim, we use the recent APOGEE
data, which provide the surface chemistry of a large sample of giant stars,
belonging to clusters that span a wide metallicity range. The APOGEE data set
is particularly suitable to discriminate among the various pollution scenarios
proposed so far, as it provides the surface abundances of Mg and Al, the two
elements involved in a nuclear channel extremely sensitive to the temperature,
hence to the metallicity of the polluters. The present analysis shows a
remarkable agreement between the observations and the theoretical yields from
massive AGB stars. In particular, the observed extension of the depletion of Mg
and O and the increase in Al is well reproduced by the models and the trend
with the metallicity is also fully accounted for. This study further supports
the idea that AGB stars were the key players in the pollution of the
intra-cluster medium, from which additional generations of stars formed in GC.Comment: Accepted on ApJ letter
Factors associated with health-seeking behavior among migrant workers in Beijing, China
<p>Abstract</p> <p>Background</p> <p>Migrant workers are a unique phenomenon in the process of China's economic transformation. The household registration system classifies them as temporary residents in cities, putting them in a vulnerable state with an unfair share of urban infrastructure and social public welfare. The amount of pressure inflicted by migrant workers in Beijing, as one of the major migration destinations, is currently at a threshold. This study was designed to assess the factors associated with health-seeking behavior and to explore feasible solutions to the obstacles migrant workers in China faced with when accessing health-care.</p> <p>Methods</p> <p>A sample of 2,478 migrant workers in Beijing was chosen by the multi-stage stratified cluster sampling method. A structured questionnaire survey was conducted via face-to-face interviews between investigators and subjects. The multilevel methodology (MLM) was used to demonstrate the independent effects of the explanatory variables on health seeking behavior in migrant workers.</p> <p>Results</p> <p>The medical visitation rate of migrant workers within the past two weeks was 4.8%, which only accounted for 36.4% of those who were ill. Nearly one-third of the migrant workers chose self-medication (33.3%) or no measures (30.3%) while ill within the past two weeks. 19.7% of the sick migrants who should have been hospitalized failed to receive medical treatment within the past year. According to self-reported reasons, the high cost of health service was a significant obstacle to health-care access for 40.5% of the migrant workers who became sick. However, 94.0% of the migrant workers didn't have any insurance coverage in Beijing. The multilevel model analysis indicates that health-seeking behavior among migrants is significantly associated with their insurance coverage. Meanwhile, such factors as household monthly income per capita and working hours per day also affect the medical visitation rate of the migrant workers in Beijing.</p> <p>Conclusion</p> <p>This study assesses the influence of socio-demographic characteristics on the migrant workers' decision to seek health care services when they fall ill, and it also indicates that the current health service system discourages migrant workers from seeking appropriate care of good quality. Relevant policies of public medical insurance and assistance program should be vigorously implemented for providing affordable health care services to the migrants. Feasible measures need to be taken to reduce the health risks associated with current hygiene practices and equity should be assured in access to health care services among migrant workers.</p
Functional characterization of cellulases identified from the cow rumen fungus Neocallimastix patriciarum W5 by transcriptomic and secretomic analyses
<p>Abstract</p> <p>Background</p> <p><it>Neocallimastix patriciarum</it> is one of the common anaerobic fungi in the digestive tracts of ruminants that can actively digest cellulosic materials, and its cellulases have great potential for hydrolyzing cellulosic feedstocks. Due to the difficulty in culture and lack of a genome database, it is not easy to gain a global understanding of the glycosyl hydrolases (<it>GHs</it>) produced by this anaerobic fungus.</p> <p>Results</p> <p>We have developed an efficient platform that uses a combination of transcriptomic and proteomic approaches to <it>N. patriciarum </it>to accelerate gene identification, enzyme classification and application in rice straw degradation. By conducting complementary studies of transcriptome (Roche 454 GS and Illumina GA IIx) and secretome (ESI-Trap LC-MS/MS), we identified 219 putative <it>GH </it>contigs and classified them into 25 <it>GH</it> families. The secretome analysis identified four major enzymes involved in rice straw degradation: β-glucosidase, endo-1,4-β-xylanase, xylanase B and Cel48A exoglucanase. From the sequences of assembled contigs, we cloned 19 putative cellulase genes, including the <it>GH1</it>, <it>GH3</it>, <it>GH5</it>, <it>GH6</it>, <it>GH9</it>, <it>GH18</it>, <it>GH43 </it>and <it>GH48 </it>gene families, which were highly expressed in <it>N. patriciarum </it>cultures grown on different feedstocks.</p> <p>Conclusions</p> <p>These <it>GH </it>genes were expressed in Pichia pastoris and/or Saccharomyces cerevisiae for functional characterization. At least five novel cellulases displayed cellulytic activity for glucose production. One β-glucosidase (W5-16143) and one exocellulase (W5-CAT26) showed strong activities and could potentially be developed into commercial enzymes.</p
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