Search

Regions around Dabie Mountain (DBM) in the Yangtze River basin (YRB) are the source of a mesoscale vortex: the Dabie vortex (DBV). Based on a 14-yr statistical study, 11 long-lived heavy-rain-producing DBVs were composited for convection-permitting semi-idealized simulations. A control simulation, initialized 12 h before the composite vortex formation, successfully reproduced a DBV, with all the salient characteristics of the 11 events. Sensitivity experiments were designed to understand the impacts of large-scale environmental conditions, regional topography, and latent heating on DBV formation. The main results were as follows: (i) Supposition of a 500-hPa shortwave trough with an east–west-oriented lower-level transversal trough around the DBM is crucial for the formation of vortices. A nocturnal lower-level jet on the southern side of the transversal trough accelerates DBV formation by enhancing convergence, triggering/sustaining convection, and producing cyclonic vorticity. (ii) During the simulation period, the topography east of the second-step mountain ranges, including the DBM, significantly affects nearby precipitation and convective activity, whereas this is not crucial for DBV formation. (iii) Latent heating is not required for generating DBVs, but it enhances the intensity, longevity, and eastward progression of these vortices along the shear line associated with the transversal trough. (iv) The vorticity budget suggests the convergence-related (horizontal) shrinking and vertical transport dominate the cyclonic-vorticity increase associated with DBVs, whereas tilting and horizontal transport mainly act in the opposite manner. [ABSTRACT FROM AUTHOR]

Low optical efficiency is a drawback of a dual-view integral imaging display based on a pinhole array. Therefore, we propose a high optical-efficiency dual-view integral imaging display. It is composed of a display panel and a non-uniform pinhole array. The left-view and right-view sub-elemental images are alternatively aligned in horizontal direction. The horizontal aperture widths of the pinholes are identical. The horizontal light rays from the left-view and right-view sub-elemental images are modulated into different directions. The vertical aperture widths of the pinholes are enlarged from upper and lower edges to center. Therefore, the vertical light rays from the sub-elemental images are not parallel. The vertical viewing angle is related to the vertical aperture width of the first row pinhole, whereas the optical efficiency is related to the vertical aperture widths of all pinholes. The optical efficiency is improved by optimizing the vertical aperture widths of the pinholes. A prototype is developed, and the experimental results prove the hypothesis. [ABSTRACT FROM AUTHOR]

The present work provides a novel method for calculating vertical velocity based on continuity equations in a pressure coordinate system. The method overcomes the disadvantage of accumulation of calculating errors of horizontal divergence in current kinematics methods during the integration for calculating vertical velocity, and consequently avoids its subsequent correction. In addition, through modifications of the continuity equations, it shows that the vorticity of the vertical shear vector (VVSV) is proportional to -ω, the vertical velocity inp coordinates. Furthermore, if the change of ω in the horizontal direction is neglected, the vorticity of the horizontal vorticity vector is proportional to -ω. When ω is under a fluctuating state in the vertical direction, the updraft occurs when the vector of horizontal vorticity rotates counterclockwise; the downdraft occurs when rotating clockwise. The validation result indicates that the present method is generally better than the vertical velocity calculated by the ω equation using the wet Q-vector divergence as a forcing term, and the vertical velocity calculated by utilizing the kinematics method is followed by the O'Brien method for correction. The plus-minus sign of the vertical velocity obtained with this method is not correlated with the intensity of dBZ, but the absolute error increases when dBZ is >=40. This method demonstrates that it is a good reflection of the direction of the vertical velocity. [ABSTRACT FROM AUTHOR]

Objective: To study the effect of ultrafiltration-membrane extracts of Radix Rehmanniae Praeparata (UMERRP) on theproliferation and genetic stability of bone marrow-derived mesenchymal stem cells (BMSCs) induced by cadmium chloride (CdCl2)., Methods: Protective effects on the proliferation, micronuclear rates, chromosome aberration rates, and apoptosis rates were observed by micronuclei test, karyotype analysis, and flow cytometry., Results: Compared with the CdCl2 group, UMERRP with different molecular weights at 0. 8 g/L could obviously promote the proliferation (P <0. 05). Compared with the control group, micronuclear rates, chromosome aberration rates, and apoptosis rates were obviously enhanced in the CdCl2 group (P <0. 05). Compared with the CdCl2 group, UMERRP with different molecular weights could obviously decreased CdCl2 induced micronuclear rates, chromosome aberration rates, and apoptosis rates (P <0. 05). Of them, BMSC micronuclear rates and chromosome aberration rates decreased most obvious in UMERRP groups with molecular weight below 10 000 (P <0. 05). The apoptosis rate decreased most obviously in UMERRP groups with molecular weight ranging 100 000 and 200 000 (P <0. 05)., Conclusion: UMERRP could reduce CdCl2 induced micronuclear rates, chromosome aberration rates, and apoptosis rates.

Objective: To observe the changes in anxiety-like behavior among rats in the recovery stage after hypoxic-ischemic brain damage (HIBD) during the perinatal period and to investigate the effect of insulin-like growth factor 1 (IGF-1) on the long-term anxiety-like behavior and its action mechanism among rats with HIBD., Methods: Ninety neonatal rats (7 days old) were randomly and equally divided into normal control, HIBD, and HIBD+IGF-1 groups. A neonatal rat model of HIBD was established by Rice method in the HIBD and HIBD+IGF-1 groups. The rats in the HIBD+IGF-1 group were intraperitoneally injected with IGF-1 (0.2 mg/kg) immediately after HIBD, and the other two groups were intraperitoneally injected with an equal volume of normal saline. The anxiety-like behavior was evaluated by elevated plus-maze test on postnatal days 21 and 28. The expression of tyrosine hydroxylase (TH) in the substantia nigra was measured by immunohistochemistry on postnatal days 14, 21, and 28., Results: On postnatal days 21 and 28, the open-arm time (OAT) and percentage of OAT for the HIBD and HIBD+IGF-1 groups were significantly lower than those for the normal control group (P<0.05), but there were no significant differences between the HIBD and HIBD+IGF-1 groups (P>0.05); the percentage of open arm entry showed no significant difference between the three groups (P>0.05). On postnatal day 14, there were no significant differences in percentage of TH immunostaining-positive area between the three groups (P>0.05). On postnatal days 21 and 28, the HIBD and HIBD+IGF-1 groups had significantly lower percentages of TH immunostaining-positive area than the normal control group (P<0.05), but there was no significant difference between the HIBD and HIBD+IGF-1 groups (P>0.05)., Conclusions: HIBD in the perinatal period may cause the changes in anxiety-like behavior in adolescent rats, which may be related to decreased expression of TH in the substantia nigra. Neonatally given IGF-1 cannot improve the long-term anxiety-like behavior in rats after HIBD, and it does not affect TH expression in the substantia nigra. IGF-1 may not regulate the changes in long-term anxiety-like behavior in adolescent rats.

Purpose: Any association between the CYP1B1 C4326G polymorphism and endometrial cancer risk remains inconclusive. In order to provide a more precise estimate, we performed the present meta-analysis., Methods: We used fixed effect or random effect models to estimate pooled odds ratios (ORs) with 95% confidence intervals (CIs) for endometrial cancer risk, with the Chi-square-based Q-test used to test for heterogeneity. Begg's and Egger's tests were adopted to check publication bias., Results: Six published case-control studies of association between the CYP1B1 C4326G polymorphism and endometrial cancer risk covering 6,577 subjects were included in the meta-analysis, but the results indicated no significant correlation with allele contrast and genotype comparisons (G vs C: OR 1.01, 95% CI 0.93-1.09; GG vs CC: OR 1.04, 95% CI 0.88-1.23; CG + GG vs CC: OR 1.08, 95% CI 0.97-1.21; GG vs CC + CG: OR 1.01, 95% CI 0.87-1.17). Heterogeneity hypothesis test did not reveal any heterogeneity and Begg's and Egger's tests did not detect obvious publication bias., Conclusions: There is no association between the CYP1B1 C4326G polymorphism and endometrial cancer risk.

Background: Defective contractile motility of the gallbladder is an important factor for gallstone formation. Estrogen might increase the risk of gallstones and cholecystitis, and estradiol inhibits the contractile activity of isolated strips of guinea pig gallbladder. The potential risks associated with hormone replacement therapy (HRT) include symptomatic gallstones. Phytoestrogen have been used to treat menopause syndromes by replacing traditional estrogen. This experiment aimed to determine the effects of the phytoestrogen genistein on the contractile response of smooth muscle strips isolated from guinea pig gallbladder and its possible mechanism of action., Methods: Guinea pigs were sacrificed to remove the whole gallbladder. Two or three smooth muscle strips were cut longitudinally. Each strip was suspended in a tissue chamber containing Krebs solution. After 2 hours of equilibration, contractile response indexes were recorded. Different concentrations of genistein were added to the chamber and the contractile responses were measured. Each antagonist was added 2 minutes before genistein to study possible mechanisms. The effect of genistein on calcium-dependent contraction curves and biphasic contraction in calcium-free Krebs solution were measured., Results: Genistein decreased the resting tension dose-dependently, and reduced the mean contractile amplitude and frequency in gallbladder strips. Ranitidine partly inhibited the effect of genistein, but methylene blue, Nomega-nitro-L-arginine, and propranolol hydrochloride did not influence this action. Genistein had no significant effects on calcium-dependent contraction. Genistein reduced the first contraction induced by acetylcholine chloride, but did not affect the second contraction caused by CaCl2., Conclusions: Genistein relaxed smooth muscle isolated from the gallbladder of guinea pigs and this might contribute to the formation of gallstones. The inhibitory action might be related to H2 receptors and the release of intracellular Ca2+ from sarcoplasmic reticulum. Replacing traditional estrogen with phytoestrogen to treat menopause syndromes may increase the risk of gallstone formation.

Objective: To investigate the pathogen of children with acute respiratory infection (ARI) in Suzhou and to provide some evidences for clinical diagnosis and treatment., Methods: The nasopharyngeal secretion samples from 2492 inpatient children with ARI, during the period of November 2005 to May 2007, were investigated for respiratory syncycial virus (RSV), influenza virus A and B, parainfluenza virus type 1, 2, 3 and adenovirus by both the indirect immunofluorescence assay and virus isolation. Human metapneumovirus (hMPV) were examined by reverse-transcription polymerase chain reaction (RT-PCR) at the same time., Results: Of 2492 samples tested, 961 (38.6%) were positive. The total positive rate of virus pathogens in children with ARI was found related to age, season and respiratory disease. The detection rates by age were: 50.0% (412/824), 43.4% (190/438), 30.5% (207/679)and 27.6% (152/551), chi(2) = 96.5002, P < 0.01; the detection rates by season were : 46.7% (366/784), 13.8% (66/478), 13.8% (59/428) and 58.6% (470/802), chi(2) = 392.3279, P < 0.01; the detection rates by disease were (acute upper respiratory infection, acute laryngitis, throat-trachea-bronchitis, bronchial pneumonia, pneumonia genuine, bronchiolitis, bronchial asthma): 21.4% (30/140), 73.7% (14/19), 32.0% (8/25), 36.9% (598/1620), 13.1% (8/61), 66.1% (216/327) and 29.0% (87/300), chi(2) = 162.1276, P < 0.01. There was no association between the total positive rate and sex. The detection rates by sex were: 39.0% (588/1508) for male and 37.9% (373/984) for female, chi(2) = 0.2962, P > 0.05. The peak of RSV appeared from December to March. There was the highest RSV detection rate 50.2% (164/327) with bronchiolitis. The hMPV can be detected all year around. The peak of hMPV appeared in winter and the detection rate was 13.2% (106/802)., Conclusion: RSV and hMPV are the main respiratory viral pathogens in Suzhou. Detection of viral pathogens in children with respiratory infection could give fast, accurate diagnostic evidence, and help avoid antibiotics abuse.

Aim: To study the effects of rhubarb (dried root of Rheum officinale Baill.) on contractile activity of isolated gastric muscle strips of guinea pigs and its possible mechanism., Methods: A total of 48 guinea pigs were killed to remove the whole stomach. Then, the stomach was opened and the mucosal layer was removed. Parallel to the circular fibers, muscle strips were cut from the body. Each isolated gastric muscle strip was suspended in a tissue chamber containing 5 mL Krebs solution, constantly warmed by water jacket at 37 degrees and bubbled continuously with a mixed gas of 950 mL/L O2 and 50 mL/L CO2. After being incubated for 1 h with 1 g tension, rhubarb of varied concentrations (1%, 2%, 7%, 20% and 70%) was added cumulatively into the tissue chamber at intervals of 2 min. Atropine (10(-6) mol/L) or isoptin (5 x 10(-8) mol/L) or hexamethonium (10(-5) mol/L) was given 2 min before the administration of rhubarb. The isometrical response was measured with an ink-writing recorder., Results: Rhubarb dose dependently increased the resting tension of gastric body circular muscle (CM) (r = 0.726, P<0.05). Atropine (r = 0.829, P<0.05), isoptin (r = 0.764, P<0.05) and hexamethonium (r = 0.797, P<0.05) did not affect its action in a dose-related manner. Atropine apparently reduced the increasing action of 1%, 3%, 10%, 30% and 100% rhubarb on the resting tension of gastric body CM. Isoptin inhibited the effect of 10%, 30% and 100% rhubarb on the resting tension of gastric body CM. Hexamethonium reduced the increasing action of 1%, 10%, 30% and 100% rhubarb on the resting tension of gastric body CM. Rhubarb increased the contractile frequency of CM of body. While atropine, isoptin and hexamethonium did not inhibit the contractile frequency of gastric body CM in comparison with rhubarb at the same concentration, rhubarb at the highest concentration (100%) decreased the mean contractile amplitude of gastric body CM. Atropine, isoptin and hexamethonium did not affect the mean contractile amplitude of gastric body CM compared to rhubarb at the same concentration., Conclusion: Rhubarb has exciting actions on isolated gastric smooth muscle strips of guinea pig. The exciting action of rhubarb is partly mediated via cholinergic M receptor, cholinergic N receptor and L-type calcium channel.