Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Language
      Language
      Clear All
      Language
  • Subject
      Subject
      Clear All
      Subject
  • Item Type
      Item Type
      Clear All
      Item Type
  • Discipline
      Discipline
      Clear All
      Discipline
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
5,279 result(s) for "Xu, Z W"
Sort by:
A comparison of eddy-covariance and large aperture scintillometer measurements with respect to the energy balance closure problem
We analyzed the seasonal variations of energy balance components over three different surfaces: irrigated cropland (Yingke, YK), alpine meadow (A'rou, AR), and spruce forest (Guantan, GT). The energy balance components were measured using eddy covariance (EC) systems and a large aperture scintillometer (LAS) in the Heihe River Basin, China, in 2008 and 2009. We also determined the source areas of the EC and LAS measurements with a footprint model for each site and discussed the differences between the sensible heat fluxes measured with EC and LAS at AR. The results show that the main EC source areas were within a radius of 250 m at all of the sites. The main source area for the LAS (with a path length of 2390 m) stretched along a path line approximately 2000 m long and 700 m wide. The surface characteristics in the source areas changed with the season at each site, and there were characteristic seasonal variations in the energy balance components at all of the sites. The sensible heat flux was the main term of the energy budget during the dormant season. During the growing season, however, the latent heat flux dominated the energy budget, and an obvious \"oasis effect\" was observed at YK. The sensible heat fluxes measured by LAS at AR were larger than those measured by EC at the same site. This difference seems to be caused by the so-called energy imbalance phenomenon, the heterogeneity of the underlying surfaces, and the difference between the source areas of the LAS and EC measurements.
Dislocations with edge components in nanocrystalline bcc Mo
We report high-resolution transmission electron microscopy (HRTEM) observation of a high density of dislocations with edge components (∼1016 m−2) in nanocrystalline (NC) body-centered cubic (bcc) Mo prepared by high-pressure torsion. We also observed for the first time of the ½ and pure edge dislocations in NC Mo. Crystallographic analysis and image simulations reveal that the best way using HRTEM to study dislocations with edge components in bcc systems is to take images along zone axis, from which it is possible to identify ½ pure edge dislocations, and edge components of ½ and mixed dislocations. The pure edge dislocations can only be identified from zone axis. The high density of dislocations with edge components is believed to play a major role in the reduction of strain rate sensitivity in NC bcc metals and alloys.
Impacts of ambient temperature on the burden of bacillary dysentery in urban and rural Hefei, China
Bacillary dysentery continues to be a major health issue in developing countries and ambient temperature is a possible environmental determinant. However, evidence about the risk of bacillary dysentery attributable to ambient temperature under climate change scenarios is scarce. We examined the attributable fraction (AF) of temperature-related bacillary dysentery in urban and rural Hefei, China during 2006–2012 and projected its shifting pattern under climate change scenarios using a distributed lag non-linear model. The risk of bacillary dysentery increased with the temperature rise above a threshold (18·4 °C), and the temperature effects appeared to be acute. The proportion of bacillary dysentery attributable to hot temperatures was 18·74% (95 empirical confidence interval (eCI): 8·36–27·44%). Apparent difference of AF was observed between urban and rural areas, with AF varying from 26·87% (95% eCI 16·21–36·68%) in urban area to −1·90% (95 eCI −25·03 to 16·05%) in rural area. Under the climate change scenarios alone (1–4 °C rise), the AF from extreme hot temperatures (>31·2 °C) would rise greatly accompanied by the relatively stable AF from moderate hot temperatures (18·4–31·2 °C). If climate change proceeds, urban area may be more likely to suffer from rapidly increasing burden of disease from extreme hot temperatures in the absence of effective mitigation and adaptation strategies.
Age-related changes and nutritional regulation of myosin heavy-chain composition in longissimus dorsi of commercial pigs
The objective of this study is to investigate the age-related changes of and the effects of dietary conjugated linoleic acid (CLA) on muscle-fibre types in commercial pigs. We divided 25 crossbred male pigs into five age groups (7, 30, 60, 100 and 180 days) and 30 finishing pigs into two dietary groups (one fed a CLA-enriched diet and the other fed a control diet for 30 days). We analysed the composition (%) of myosin heavy-chain (MyHC) mRNA according to the absolute copies of each MyHC (I, IIa, IIb and IIx) mRNA, and the activities of succinate dehydrogenase (SDH) and malate dehydrogenase (MDH) in the longissimus muscle. From days 7 to 180, the MyHC I mRNA abundance and SDH and MDH activities presented a decreasing trend, the MyHC IIb mRNA abundance presented a steady trend and the MyHC IIa and IIx mRNA abundances presented an increasing trend. On day 30, MyHC I and IIb mRNA abundances were at their lowest (P < 0.05), and the MyHC IIa and IIx mRNA abundances were at their highest (P < 0.05). In the CLA group, the MyHC I mRNA abundance and the activities of SDH and MDH were improved in the longissimus muscle, whereas pressure loss, drip loss and average back fat depth significantly decreased (P < 0.01) and shear force significantly increased (P < 0.01). Loin eye area, feed conversion rate and meat colour showed some tendency to be improved. These results indicated that more oxidative fibres might convert to glycolytic fibres with increasing age or weight, and that the early developmental stage might be a key stage for this conversion. During the finishing stage, the proportion of oxidative fibres might be increased by dietary CLA supplementation, which may contribute to the water-holding capacity of meat. The results would provide an important basis for the application of muscle-fibre types in the improvement of pork quality.
Impact of metabolic syndrome on myocardial injury and clinical outcome after percutaneous coronary intervention
Aims This study tested the associations between metabolic syndrome, postprocedural myocardial injury, and clinical outcome after percutaneous coronary intervention. Patients and methods We evaluated 204 patients who fulfilled the study criteria and were scheduled for elective percutaneous coronary intervention. The patients were divided into a metabolic syndrome group and a control group according to the definition of metabolic syndrome. Creatine kinase-MB and troponin I levels were measured at baseline, at 8 h, and 24 h after the procedure, while clinical outcomes were followed up for 1 year. Results The incidence of postprocedural myocardial injury was significantly higher in the metabolic syndrome group than in the control group as indicated by either blood creatine kinase-MB elevation (32.9 % vs. 17.2 %, p = 0.010) or troponin I elevation (34.2 % vs. 17.2 %, p = 0.006). Postprocedural peak values of creatine kinase-MB (5.724 ± 7.678 ng/ml vs. 3.097 ± 5.317 ng/ml, p < 0.001) and troponin I (0.066 ± 0.093 ng/ml vs. 0.038 ± 0.079 ng/ml, p < 0.001) were also significantly higher in the metabolic syndrome group than in the control group. On multiple regression analysis, metabolic syndrome was independently associated with troponin I elevation (odds ratio 2.24, 95 % confidence interval, CI, 1.04–4.80, p = 0.039). During the 1-year follow-up, cardiac events occurred in 28.9 % of patients with metabolic syndrome and 17.9 % of controls, and there was a trend toward increased adverse outcomes in the metabolic syndrome group (hazard ratio 1.67, 95 % CI 0.93–3.00, p = 0.071, log rank test). Conclusion The results of this study demonstrate that metabolic syndrome is associated with postprocedural myocardial injury and with increased cardiac events.
On the vertical drift of ionospheric F layer during disturbance time: Results from ionosondes
The morphology of low‐latitude ionosphere is greatly affected by the zonal electric field, especially at disturbance time. In this study, historical data from two low‐latitude ionosondes located at Haikou and Chongqing, China, are used to study the disturbance vertical drift properties of ionospheric F layer during the initial and main phases of 50 intense storms. The disturbance drift from an empirical model is used as an indicator to denote the E × B disturbance magnitude. It is found that the drifts both at the base and at the peak height are increased in magnitude when the disturbance becomes stronger. For the same disturbance, ionospheric vertical drifts at the base height are comparable with those at the peak height over Haikou, but they are larger than the latter over Chongqing, both drifts being smaller than those at the magnetic equator. The drifts are larger in daytime than in nighttime, but no rule is found on their seasonal dependence. This indicates that low‐latitude storm time ionospheric vertical drift of the ionospheric layer exhibits both consistent and individual properties at different locations. Key Points The drift is strengthened versus stronger disturbance The drift exhibits both holistic and individual properties versus locations The drift shows much local time dependence but little seasonal dependence
Change of nitric oxide in experimental colitis and its inhibition by melatonin in vivo and in vitro
Aim: To investigate the change of nitric oxide (NO) in rat colitis and its inhibition by melatonin in vivo and in vitro. Methods: In vivo, rat colitis was established intracolonically with trinitrobenzenesulphonic acid (TNBS) and ethanol. The animals were randomised into five groups: control group, model group, melatonin group (2.5, 5.0, 10.0 mg/kg), and treated intracolonically with saline, saline and melatonin respectively (once a day, from day 7 after colitis was established to day 28). After the end of the experiment, the mucosal damage index (CMDI) and histology score (HS) were evaluated and the level of myeloperoxidase (MPO) and malondiadehyde (MDA) and NO in the colon tissue were measured. In vitro, the co-culture model of the inflamed colon mucosa (from the colitis) with lipopolysaccharide (LPS), and the colonocytes oxidative injury model by hydroxyl radical, were designed respectively to elucidate the inhibition of NO by melatonin. Results: After treated with TNBS/ethanol, the extent of CMDI and HS, the levels of MPO, MDA, and NO in the model group, were higher than that in the control group; melatonin ameliorated these parameters effectively. The stimulation of LPS increased the level of NO and MPO and MDA in the co-culture model of inflamed colon mucosa, and melatonin significantly reduced the level of MPO, MDA, and NO. In the coloncyte oxidative injury model by hydroxyl radical, the contents of LDH, MDA, and NO were increased; melatonin reversed this oxidative injury considerably. Conclusion: This study showed that TNBS/ethanol induced colitis was pharmacologically controlled by melatonin in vivo and in vitro.
Porcine glucagon-like peptide-2 microspheres ameliorate inflammation in lipopolysaccharide-challenged weaning piglets
This study aimed to investigate the effects of porcine [gly2] glucagon-like peptide-2 (p[gly2]GLP-2) microspheres on lipopolysaccharide-challenged piglets and to evaluate efficacy of microspheres for administration compared with more conventional administration. Eighteen 21-d-old Duroc female piglets were randomly assigned into 3 groups: the control group (intraperitoneal injection with 3 mL saline solution daily), the glucagon-like peptide-2 (GLP-2) group (intraperitoneal injection with 3 mL p[gly2]GLP-2 at 20 nmol/kg BW daily), and the microsphere (MS) group (intraperitoneal injection with 100 mg p[gly2]GLP-2 microsphere suspension at Day 1). On Day 8, all piglets were injected with 100 μg lipopolysaccharide/kg BW. Results showed that administration of p[gly2]GLP-2 microspheres decreased the -lactic acid and methane dicarboxylic aldehyde content of the serum and increased the villus height and villus crypt ratio in the duodenum and ileum. Inducible nitric oxide synthase activity in the duodenum and ileum decreased, whereas enzyme activity for sucrose and Na-K adenosine triphosphatase in the ileum increased with treatment of p[gly2]GLP-2 microspheres. In the MS group, we observed downregulation of IL-8, TNF-α, IFN-γ, and GLP-2R mRNA expression in the ileum, upregulation of positive cell expression in the duodenum and positive cell expression in the ileum, and downregulation of GLP-2 receptor positive cell expression in the ileum. One injection of p[gly2]GLP-2 microspheres was as effective as p[gly2]GLP-2 administered for 7 d. Results suggested that p[gly2]GLP-2 can be a candidate agent for ameliorating weaning stress in piglets and that the use of microspheres is an ideal delivery system for GLP-2.
Forecasting the local ionospheric foF2 parameter 1 hour ahead during disturbed geomagnetic conditions
Using the support vector machine (SVM), an empirical local ionospheric forecasting model over Lanzhou (ELIFMOL) has been developed to predict the critical frequency of the F2 layer (foF2) during disturbed geomagnetic conditions. This study focuses on the reliable prediction of foF2 during geomagnetic storms, which is important for practical applications as well as for further understanding of the storm dynamics. In this paper, we investigate whether foF2 during disturbed geomagnetic conditions at a single station can be well predicted one hour ahead by using some inputs to an SVM network, such as the latest foF2 observations, hourly quiet time foF2 (foF2QT), time, and the hourly time‐weighted accumulation series derived from the geomagnetic index (ap(τ)). The input observation data cover the period of January 1958 to December 2000 at Lanzhou (36.1°N, 104.0°E) in China. The foF2 forecasted by the ELIFMOL are compared with the monthly median values and with those by the STORMMEDIAN model, the persistence model, and the STORMfoF2QT model during geomagnetic storms occurring from 2001 to 2006. As for the data sets used in this paper, the results show that the performance of ELIFMOL is better than that of the latter models.
Is vertebroplasty a risk factor for subsequent vertebral fracture, meta-analysis of published evidence?
Summary In our paper, we systemically retrieved the eligible study evaluating whether increased incidence of subsequent vertebral fracture is associated with vertebroplasty. Main effect sizes were vertebral fracture rates reported in terms of hazard ratio (HR) for time-to-event data or relative risk (RR) for dichotomous outcome. Our results do not support the hypothesis that vertebroplasty contributes to increased risk of subsequent vertebral fracture, neither adjacent nor total vertebral fracture. Introduction Vertebroplasty has been implicated in significant changes in vertebral strength, vertebral shape, and consequently increased risk for subsequent vertebral fracture, especially the adjacent level. Here, we further tested the hypothesis whether new-onset vertebral fracture is a natural result of osteoporosis or consequence of cement augmentation. Methods Relevant literatures were retrieved using PubMed, Web of Knowledge, and Cochrane Central Register of Controlled Trials (CENTRAL), supplemented by a hand-search of the reference lists of selected articles. Eligible studies assessed whether increased morbidity of subsequent vertebral fracture is associated with vertebroplasty. Main effect sizes were vertebral fracture rates reported in terms of hazard ratio (HR) for time-to-event data or relative risk (RR) for dichotomous outcome. Random-effects model was used to account for clinical or methodological heterogeneity across studies. Results Thirteen studies with a number of 2,551 individuals (1,631 in vertebroplasty group and 920 in control group) were suitable for this meta-analysis. In trials that reported adjacent vertebral fracture as time-to-event data (two trials, n  = 328), we found a similar incidence of vertebral fracture in percutaneous vertebroplasty (PVP) group compared to conservative therapy (HR 0.60, 95 % confidence interval 0.29 to 1.26; P  = 0.18). In trials that reported overall vertebral fracture as time-to-event data (three trials, n  = 704), vertebroplasty was associated with a slightly increased but non-significant risk for vertebral fracture (HR 1.14, 95 % confidence interval 0.65 to 2.00; P  = 0.65). The outcome was further confirmed in the secondary meta-analysis of studies that reported vertebral fracture as dichotomous data. Subgroup analysis according to study design revealed no difference either. Conclusions Our results do not support the hypothesis that vertebroplasty contributes to increased risk of subsequent vertebral fracture, neither adjacent nor total vertebral fracture. However, adequately designed randomized controlled trials are warranted to confirm the present findings.