973 research outputs found

    The tensor renormalization group study of the general spin-S Blume-Capel model

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    We focus on the special situation of D=2JD=2J of the general spin-S Blume-Capel model on the square lattice. Under the infinitesimal external magnetic field, the phase transition behaviors due to the thermal fluctuations are discussed by the newly developed tensor renormalization group method. For the case of the integer spin-S, the system will undergo SS first-order phase transitions with the successive symmetry breaking with the magnetization M=S,S−1,...0M=S,S-1,...0. For the half-integer spin-S, there are similar S−1/2S-1/2 first order phase transition with M=S,S−1,...1/2M=S,S-1,...1/2 stepwise structure, in addition, there is a continuous phase transition due to the spin-flip Z2Z_2 symmetry breaking. In the low temperature regions, all first-order phase transitions are accompanied by the successive disappearance of the optional spin-component pairs(s,−ss,-s), furthermore, the critical temperature for the nth first-order phase transition is the same, independent of the value of the spin-S. In the absence of the magnetic field, the visualization parameter characterizing the intrinsic degeneracy of the different phases clearly demonstrates the phase transition process.Comment: 6 pages, 7 figure

    Effect of low intensity white light irradiation on the retinas of mice

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    AIM: To investigate the effect of low intensity white light irradiation on the retinas of mice.<p>METHODS: Thirty C57BL/6J mice were randomly divided into two groups. The number of the mice in each group was 15. The mice in experimental group received dark adaptation from 5:00p.m. to 6:00p.m.,and then exposed to LED white light from 6:00p.m. to 7:00p.m. everyday for a month. At 1, 3, 7, 14 and 30d after the beginning, we examed the histology of mice retinas, calculated the thickness of outer nuclear layer(ONL),inner nuclear layer(INL)and analyzed electrophysiology of mice.<p>RESULTS:One month after experiment, compared to the control group, the latency of Rod-R a wave of the mice in experimental group significantly prolonged, the amplitude of Cone-R b wave of the mice in experimental group significantly decreased and the latency of b wave of the mice in experimental group significantly prolonged(<i>P</i><0.05).There are no significant difference in the histology of retina, ONL and INL thicknesses.<p>CONCLUSION: 100lux low intensity white light could give rise to the impairment of the retinal functions in dark-adapted mice

    A STUDY ON THE EFFECT OF RESVERATROL ON LIPID METABOLISM IN HYPERLIPIDEMIC MICE

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    Background: The content of resveratrol is relatively high in Polygonum cuspidatum Sieb. et Zucc., and the resveratrol has the effect of blood vessel dilating, microcirculation improving, platelet aggregation inhibiting and anti-cancer. The objective of this paper was to study the effect of resveratrol on lipid metabolism in hyperlipidemia mice. Materials and Methods: Through the establishment of an experimental mouse model of hyperlipidemia, the effect of resveratrol on change in total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-c), and low-density lipoprotein cholesterol (LDL-c) levels in mouse serum were determined. Results: Resveratrol group can apparently reduce TC, TG, LDL-c and AI of hyperlipidemic mice in a dose effect manner. Conclusion: We concluded that resveratrol can effectively reduce blood lipid levels of hyperlipidemic mice

    Symbiosis-stimulated chitinase isoenzymes of soybean (Glycine max (L.) Merr.)

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    Isoforms of endochitinase in soybean were studied in relation to root symbiosis. Five selected cultivars differing in their nodulation potential were inoculated with two strains of Bradyrhizobium japonicum, the broad host-range Rhizobium sp. NGR234, and with the mycorrhizal fungus Glomus mosseae. Total chitinase activity in nodules was up to 7-fold higher than in uninoculated roots and in mycorrhizal roots. The chitinase activity in nodules varied depending on the strain-cultivar combination. On semi-native polyacrylamide gels, four acidic isoforms were identified. Two isoforms (CH 2 and CH 4) were constitutively present in all analysed tissues. The other two isoforms (CH 1 and CH 3) were strongly induced in nodules and were stimulated in mycorrhizal roots as compared to uninoculated roots. The induction of CH 1 varied in nodules depending on the soybean cultivar. This isoform was also stimulated in uninfected roots when they were treated with tri-iodobenzoic acid, rhizobial lipochitooligosaccharides (Nod factors) and chitotetraose. CH 3 was not affected by these stimuli indicating that this isoform could represent a marker for enzymes induced in later stages of the symbiotic interaction

    Excitatory and inhibitory effects of prolactin release activated by nerve stimulation in rat anterior pituitary

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    <p>Abstract</p> <p>Background</p> <p>A series of studies showed the presence of substantial amount of nerve fibers and their close relationship with the anterior pituitary gland cells. Our previous studies have suggested that aside from the classical theory of humoral regulation, the rat anterior pituitary has direct neural regulation on adrenocorticotropic hormone release. In rat anterior pituitary, typical synapses are found on every type of the hormone-secreting cells, many on lactotrophs. The present study was aimed at investigating the physiological significance of this synaptic relationship on prolactin release.</p> <p>Methods</p> <p>The anterior pituitary of rat was sliced and stimulated with electrical field in a self-designed perfusion chamber. The perfusate was continuously collected in aliquots and measured by radioimmunoassay for prolactin levels. After statistic analysis, differences of prolactin concentrations within and between groups were outlined.</p> <p>Results</p> <p>The results showed that stimulation at frequency of 2 Hz caused a quick enhancement of prolactin release, when stimulated at 10 Hz, prolactin release was found to be inhibited which came slower and lasted longer. The effect of nerve stimulation on prolactin release is diphasic and frequency dependent.</p> <p>Conclusions</p> <p>The present in vitro study offers the first physiological evidence that stimulation of nerve fibers can affect prolactin release in rat anterior pituitary. Low frequency stimulation enhances prolactin release and high frequency mainly inhibits it.</p

    Expression of Toll-Like Receptor 4, Tumor Necrosis Factor- Alpha, Matrix Metalloproteinase-9 and Effects of Benazepril in Patients with Acute Coronary Syndromes

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    Objectives The study aims to explore the relationship between expressions of toll-like receptor 4 (TLR4) on peripheral blood monocytes, serum tumor necrosis factor-alpha (TNF-α) and matrix metalloproteinase-9 (MMP-9) in patients with acute coronary syndromes(ACS), and to investigate the possible mechanisms of Benazepril stabilizing atherosclerosis plaques. Methods 70 patients selected were randomly divided into Benazepril treatment group (35 patients) and regular treatment group (35 patients). Meanwhile, Stable angina pectoris (SAP) group of 32 patients and control group of 22 patients were also set up. With the help of flow-cytometry, expressions of TLR4 on peripheral blood monocytes of the four groups were analyzed and compared to show differences, correlations and changes of the above mentioned indicators. The concentration of TNF-α and MMP-9 in serum were measured by enzyme linked immunosorbent assay (ELISA). Results (1) Expressions of TLR4, levels of TNF-α and MMP-9 were increased and the rate was rising from the control group, to SAP group and then to ACS group. All these indicators in ACS group are significantly higher than those in other groups ( P 0.05) while they all fell after treatment ( P < 0.05). In addition, all the indicators decreased more greatly than the regular treatment group. Conclusions TLR4 on peripheral blood monocytes and serum TNF-α and MMP-9 in patients with coronary arteriosclerosis disease may be effective markers of the vulnerable plaque. Benazepril can inhibit over-expression of TLR4 and reduce serum levels of TNF-α and MMP-9, thus stabilize the vulnerable plaques and improve the condition of the patients with ACS

    Ophiopogon japonicas (Linn. f.) Ker-Gawl. extract ameliorates chronic heart failure in rats

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    Purpose: To investigate the effect of Ophiopogon japonicas (Linn. f.) Ker-Gawl. extract (OJKE) on oxidative stress and hemodynamics in chronic congestive heart failure (CHF) rats. Methods: The rats were modelled to congestive heart failure (except normal group) , and then randomly divided into normal control group, model (untreated) group, captopril group, high-dose, middle-dose and low-dose of OJKE groups. They were treated for 4 weeks as appropriate for each group. At the end of treatment, the hemodynamic function, whole heart weight index, and blood creatinine kinase (CK), as well as superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO), nitricoxide synthase (NOS) were determined. Results: Compared with the normal control group, arterial systolic pressure (SBP), diastolic pressure (DBP), mean arterial pressure (MAP), heart rate (HR), left ventricular systolic peak (LVSP), and left ventricular pressure change rate (dp/dt max) significantly decreased (p &lt; 0.05), while left ventricular end diastolic pressure (LVEDP), whole heart weight index, blood CK, MDA, NO, NOS significantly increased in the untreated group (p &lt; 0.05). A high dose of OJKE significantly improved hemodynamic function, lowered MDA (8.33 ± 2.12 nmol/mL) and NO (20.58 ± 3.53 umol/L) levels (p &lt; 0.05), and also decreased CK (0.53±0.37 U/mL) and NOS (22.46±3.29 U/mL) in CHF rats (p &lt; 0.05). Conclusion: OJKE improved adriamycin-induced chronic congestive heart failure in rats significantly

    Visualizing the dynamic behavior of poliovirus plus-strand RNA in living host cells

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    Dynamic analysis of viral nucleic acids in host cells is important for understanding virus–host interaction. By labeling endogenous RNA with molecular beacon, we have realized the direct visualization of viral nucleic acids in living host cells and have studied the dynamic behavior of poliovirus plus-strand RNA. Poliovirus plus-strand RNA was observed to display different distribution patterns in living Vero cells at different post-infection time points. Real-time imaging suggested that the translocation of poliovirus plus-strand RNA is a characteristic rearrangement process requiring intact microtubule network of host cells. Confocal-FRAP measurements showed that 49.4 ± 3.2% of the poliovirus plus-strand RNA molecules diffused freely (with a D-value of 9.6 ± 1.6 × 10(−10) cm(2)/s) within their distribution region, while the remaining (50.5 ± 2.9%) were almost immobile and moved very slowly only with change of the RNA distribution region. Under the electron microscope, it was found that virus-induced membrane rearrangement is microtubule-associated in poliovirus-infected Vero cells. These results reveal an entrapment and diffusion mechanism for the movement of poliovirus plus-strand RNA in living mammalian cells, and demonstrate that the mechanism is mainly associated with microtubules and virus-induced membrane structures

    Human Bocavirus Infection, People’s Republic of China

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    A newly identified parvovirus, human bocavirus (HBoV), was found in 21 (8.3%) of 252 nasopharyngeal aspirates from hospitalized children with lower respiratory tract infection in Hunan Province, People’s Republic of China. Viral loads were 104 to 1010 copies/mL. Phylogenetic analysis of the VP1 gene showed a single genetic lineage of HBoV worldwide
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