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Now showing items 129 - 144 of 207

  • Down-regulation of ghrelin receptors in the small intestine delays small intestinal transit in vagotomized rats.

    Yang, Cheng-Guang   Qiu, Wen-Cai   Wang, Zhi-Gang   Yu, Song   Yan, Jun   Zheng, Qi  

    Vagal nerve injury may occur in esophageal and gastric surgeries. The aim of this study was to observe the effects of ghrelin on small intestinal motility upon vagal nerve injury and the possible co-relationship between changes in ghrelin receptor expression in the small intestine and delayed small intestinal transit after vagotomy. The effects of intraperitoneal administration of ghrelin (20, 40 and 80 g/kg) and the ghrelin receptor antagonist [D-Lys3]-GHRP-6 (1.5 mol/kg) on small intestinal transit were studied in control and vagotomized rats in vivo. The effects of ghrelin (0.01, 0.1, 0.5, 1.0 and 2.0 mol/l) on the contraction force of smooth muscle strips from the jejunum were studied in the presence or absence of carbachol (50 nmol/l) and [D-Lys3]-GHRP-6 (10 mol/l) in vitro. Ghrelin receptor expression was assessed in intestinal muscle layers by means of Western blotting. The results indicated that ghrelin dose-dependently increased small intestinal transit in the control and model rats. In addition, ghrelin enhanced smooth muscle strip contraction induced by carbachol. Ghrelin receptor antagonist [D-Lys3]-GHRP-6 blocked the effect of ghrelin. Ghrelin receptor expression in the small intestinal muscle layers was down-regulated in the vagotomized rats. Down-regulation of growth hormone secretagogue receptor 1a in small intestinal muscle layers, which affected the function of ghrelin, may be one of the mechanisms behind delayed small intestinal transit after vagotomy.
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  • Contribution of interspecific interactions and phosphorus application to sustainable and productive intercropping systems

    Xia, Hai-Yong   Wang, Zhi-Gang   Zhao, Jian-Hua   Sun, Jian-Hao   Bao, Xing-Guo   Christie, Peter   Zhang, Fu-Suo   Li, Long  

    Rational soil/rhizosphere-plant phosphorus (P) management strategies in intercropping systems are poorly understood. Three years of field experiments with different rates of P fertilizer (0, 40 and 80 kg ha(-1)) as main effects and maize (Zea mays L) intercropping with oilseed rape (Brassica napus L.), turnip (Brassica campestris L), faba bean (Vicia faba L.), chickpea (Cicer arietinum L) and soybean (Glycine max L.) with the respective monocultures as subplot effects were carried out to study the influence of fertilizer P application on productivity, shoot P content, apparent recovery of fertilizer P and soil Olsen-P in intercrops and monocultures. Average total grain yields and shoot P contents of maize/turnip, maize/faba bean, maize/chickpea and maize/soybean intercropping increased by 30.7%, 24.8%, 24.4%, and 25.3% and by 44.6%, 30.7%, 39.1%, and 28.6%, respectively, compared with the weighted means of the corresponding monocultures, and were highest at 40 kg Pha(-1). Moreover, the average apparent recovery of fertilizer P of the intercropping systems increased from 6.1% to 30.6% at 40 kg Pha(-1) and from 4.8% to 14.5% at 80 kg Pha(-1) compared with overall monoculture systems on average over three years. The results indicate that intercropping and a rational P application rate (e.g. 40 kg Pha(-1)) maintained maximum total grain production and shoot P content, P balance of inputs/outputs and soil Olsen-P at an appropriate level (21.3 mg kg(-1)), and maximum apparent recovery of fertilizer P (30.6%) through exploitation of the biological potential for efficient acquisition of P and other resources by interspecific interactions toward a sustainable and productive agricultural system. (C) 2013 Elsevier B.V. All rights reserved.
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  • Boundedness of Toeplitz-type operator associated to general integral operator on L-p spaces with variable exponent

    Yuan, Xin-Sheng   Wang, Zhi-Gang  

    In this paper, the boundedness for some Toeplitz-type operator related to some general integral operator on L-p spaces with variable exponent is obtained by using a sharp estimate of the operator. The operator includes Littlewood-Paley operator, Marcinkiewicz operator and Bochner-Riesz operator.
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  • Chronic lipopolysaccharide exposure induces cognitive dysfunction without affecting BDNF expression in the rat hippocampus

    Zhu, Bin   Wang, Zhi-Gang   Ding, Jie   Liu, Ning   Wang, Da-Ming   Ding, Liang-Cai  

    Previous studies have shown that lipopolysaccharide (LPS) has the potential to cause cognitive dysfunction. However, the underlying pathogenesis has yet to be fully elucidated. Increasing attention is being focused on infection in the central nervous system. Therefore, the present study aimed to investigate the behavioral performance of rats receiving intraperitoneal injections of LPS and to determine the expression levels of amyloid- (A), brain-derived neurotrophic factor (BDNF) and pro-inflammatory cytokines in the hippocampus. In total, 30 male Wistar rats were randomly divided into 3 groups (each n=10): Control and 3 and 7 day LPS administration groups. The rats were intraperitoneally injected with saline or LPS for 3 or 7 days. Following this, rats performed the Morris water maze test, in which the latency to the platform and proportion of time spent in the target quadrant were recorded. Rats were then sacrificed and the hippocampi were harvested for determination of interleukin (IL)-1, IL-6, tumor necrosis factor- (TNF-), A and BDNF expression levels. LPS administration for 3 and 7 days significantly increased the latency to the platform and decreased the proportion of time spent in the target quadrant compared with those in the control group, (P<0.05). Administration of LPS for 3 and 7 days induced statistically significant increases in the expression levels of IL-1, IL-6 and TNF- in the hippocampus, compared with those in the control group (P<0.05). Additionally, the administration of LPS for 7 days induced a statistically significant increase in the expression level of A in the hippocampus, compared with that in the control group (P<0.05). However, the administration of LPS did not elicit a statistically significant change in the expression level of BDNF in the hippocampus, compared with that in the control group (P>0.05). The results indicate that LPS induces cognitive dysfunction, which is associated with increased expression levels of pro-inflammatory cytokines and A, but does not affect the expression of BDNF in the hippocampus.
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  • Insights into microstructural formation of pulse plasma semisolid to liquid processing of Al2O3-ZrO2 eutectic ceramics

    Wang, Zhi-Gang   Ouyang, Jia-Hu   Ma, Yong-Hui   Wang, Yu-Jin   Liu, Zhan-Guo   Henniche, Abdelkhalek   Xie, Ling-Yun  

    This present work concentrated on a novel one-step pulse discharge plasma melting method, directly from a powder mixture of nano-sized Al2O3-ZrO2(Y2O3) to insitu fabricate Al2O3-ZrO2 binary eutectic in a short processing time. A continuous transition from submicro-sized polycrystalline to non-equilibrium eutectic was traced based on pulse discharge plasma semisolid to liquid processing. The uniform colony microstructure with an average inter-lamellar or inter-rod spacing of similar to 200nm was obtained at a growth rate of similar to 275m/s, and the inter-lamellar or inter-rod spacing was a good fit for the inverse-square-root dependence of the growth rate as (a)=3D3.32xv(-1/2).
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  • Analysis of the axial vector B c -like tetraquark states with the QCD sum rules

    Wang, Zhi-Gang  

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  • Lamellar Formation and Relaxation in Simple Sheared Poly(ethylene terephthalate) by Small-Angle X-ray Scattering

    Wang, Zhi-Gang   Xia, Zhi-Yong   Yu, Zhen-Qiang   Chen, Er-Qiang   Sue, Hung-Jue   Han, Charles C.   Hsiao, Benjamin S.  

    Semicrystalline poly(ethylene terephthalate) (PET) was oriented with an equal channel angular extrusion (ECAE) process at room temperature, which applied simple shear deformation and generated unique asymmetric lamellar texture. In-situ small-angle X-ray scattering (SAXS) measurements were utilized to study the changes of lamellar structure during heating in samples with and without experiencing the simple shear deformation. The total scattered intensity, fractions of isotropic and anisotropic scattered intensities, orientation factors, and long periods along different shear directions were determined from 2-dimensional SAXS patterns. Orientation-stable a-lamellae with their normal perpendicular to the shear plane exhibited a larger long period after shear and a rapid decrease in long period upon heating, while less orientation-stable beta-lamellae with their normal perpendicular to the flow direction exhibited a smaller long period after shear but only a slight decrease in long period upon heating. The thermally induced lamellar misorientaton could be attributed to the processes of lamellar relaxation and recrystallization of the amorphous phase. The possible molecular mechanisms for lamellar formation during simple shear are also discussed.
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  • PA/US dual-modality imaging to guide VEGFR-2 targeted photothermal therapy using ZnPc-/PFH-loaded polymeric nanoparticles.

    Chen, Yu-Li   Liu, Feng-Qiu   Guo, Yuan   Cheng, Juan   Yang, Lu   Lu, Min   Li, Pan   Xu, Jie   Yu, Tao   Wang, Zhi-Gang   Cao, Yang   Ran, Hai-Tao  

    Angiogenesis is a common pathological characteristic of many solid tumors and vulnerable atherosclerotic plaques. Photothermal therapy (PTT) is a promising method to reduce neovascularization. To increase the targeting ability and efficiency of PTT, a novel polymeric nanosystem that encapsulates phthalocyanine zinc (ZnPc) and perfluorohexane (PFH) was developed to target the new blood vessels of breast tumors. After being conjugated to the anti-VEGFR-2 antibody, the polymeric nanoparticles (NPs) targeted vascular endothelial cells efficiently. The photosensitizer (PS) in the NPs could convert laser energy into heat, generating local high temperatures to kill the surrounding cells under laser irradiation. In addition, the liquid-gas phase transition of PFH was induced, and an enhanced ultrasound (US) and photoacoustic (PA) image could be obtained. US/PA imaging enables visualization of the location of NPs, and laser irradiation position can be guided to the optimal location, resulting in fewer side effects than those from traditional treatments with a high targeting ability and an efficient synergistic effect from the PTT.=20
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  • Reanalysis of the Y(3940), Y(4140), Z(c)(4020), Z(c)(4025), and Z(b)(10650) as molecular states with QCD sum rules

    Wang, Zhi-Gang  

    In this article, we calculate the contributions of the vacuum condensates up to dimension 10 in the operator product expansion, and study the , , , , , molecular states with the QCD sum rules. In the calculations, we use the formula to determine the energy scales of the QCD spectral densities. The numerical results favor assigning the and to the , or molecular states, the to the molecular state, the to the molecular state, and they disfavor assigning the to the () molecular state. The present predictions can be confronted with the experimental data in the future.
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  • Design,synthesis,crystal structure and bioactivity evaluation of novel diethyl (arylfuranyl)(arylpyrazolylamino)methanephosphonates

    Chen, Fu-li   Wang, Xin-lin   Wang, Zhi-gang   Han, Zhen-yu   Fu, Xiao-huan   Jiang, Peng   Wan, Rong  

    Aseries of novel arylpyrazole derivatives containing aminomethanephosphonate and phenylfuran moieties were designed, synthesized and characterized by H-1 NMR, P-31 NMR and IR spectroscopy and elemental analyses. The single crystal structure of diethyl [5-(4-chlorophenyl)furan-2-yl][3-cyano-1-(2,3,4-trifluorophenyl)1H-pyrazol-5-ylamino] methanephosphonate (4l) was determined by X-ray diffraction. Preliminary bioassays showed that these phosphonates exhibit satisfactory insecticidal activities against Culexpipiens and Musca domestica at 0.1%. In particular, compound 4l exhibited a most promising KT50 value, which is superior to that of Dextraltetramethrin (R) and similar to Prallehtrin (R). The structure-activity relationship was also preliminarily investigated.
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  • Analysis of the Possible $D{\bar{D}}_{s0}^{* }(2317)$ and ${D}^{* }{\bar{D}}_{s1}^{* }(2460)$ Molecules with QCD Sum Rules

    Di, Zun-Yan   Wang, Zhi-Gang   Yu, Guo-Liang  

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  • Intercropping maintains soil fertility in terms of chemical properties and enzyme activities on a timescale of one decade

    Wang, Zhi-gang   Bao, Xing-guo   Li, Xiao-fei   Jin, Xin   Zhao, Jian-hua   Sun, Jian-hao   Christie, Peter   Li, Long  

    Background Overyielding (i.e., mixtures of crops yielding higher than expected when compared with monocultures) and increased nutrient acquisition have been found in many intercropping systems. However, there are very few published studies on long-term changes in soil chemical and biological properties in intercropping systems compared to sole cropping. Methods A field experiment was established in 2003 in Gansu province, northwest China. The treatments comprised three intercropping systems (either continuous or rotational wheat/maize, wheat/faba bean, maize/faba bean intercropping), rotational cropping (wheat-maize, wheat-faba bean, faba bean-maize, and wheat-maize-faba bean rotations), and monocropping (sole wheat, faba bean and maize) systems. In 2011 (ninth year of the experiment) and 2012 (tenth year) the yields and some soil chemical and biological properties were examined after all crop species were harvested. Results There was overyielding by 6.6 % and 32.4 % in wheat/maize intercropping in 2011 and 2012, respectively. Faba bean/maize intercropping was enhanced by 34.7 % and 28.6 %, respectively but not wheat/faba bean intercropping. Soil organic matter, total nitrogen, Olsen P, exchangeable K and cation exchange capacity in all intercropping systems did not differ from the monocultures except for soil pH in wheat/maize and faba bean/maize intercropping in 2011 and soil exchangeable K and cation exchange capacity (CEC) in 2012. Soil pH in wheat/maize and faba bean/maize intercropping was significantly reduced by 3.2 % and 1.9 %, respectively. Soil exchangeable K in wheat/maize, faba bean/maize and wheat/faba bean intercropping declined markedly by 15 %, 21.7 % and 12.1 %, respectively. Soil cation exchange capacity in wheat/maize, faba bean/maize and wheat/faba bean intercropping was notably lower than the corresponding monocultures by 17.5 %, 23.3 % and 18.3 %, respectively. Soil enzyme activities after 9 and 10 years of intercropping differed little from monocultures or rotations. Conclusions The results indicate that intercropping overyielded compared with monocropping or rotational cropping and also maintained the stability of most of the soil chemical and enzyme activities relative to rotations and monocropping in the relatively fertile soil studied.
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  • Superelastic Cage Implantation A New Technique for Treating Osteonecrosis of the Femoral Head with Mid-Term Follow-ups

    Wang, Yan   Chai, Wei   Wang, Zhi-Gang   Zhou, Yong-Gang   Zhang, Guo-Qiang   Chen, Ji-Ying  

    We developed a device for the treatment of Ficat and Arlet stage II and III osteonecrosis of the femoral head. This device, which we named the "super-elastic cage," was designed to provide mechanical support for the necrotic weight-bearing area of the femoral head to prevent its collapse. The cage was used in combination with surgical removal of necrotic bone, insertion of vascularized pedical bone graft, or impacted autologous cancellous bone graft. A total of 93 hips in 62 patients at Ficat stage II to III were included in a 8-year Study. implantations were performed by 2 different approaches: Smith-Peterson approach and minimal invasive approach by the lateral side of great trochanter. The follow-up period was between 72 and 107 months. of the femoral heads in this study, 82.7% survived. The superelastic cage implantation technique may offer an alternative treatment to the early and middle stages of osteonecrosis of the femoral head.
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  • Analysis of the strong coupling constant GDs*Ds&phi and the decay width of Ds* -> Ds gamma with QCD sum rules

    Yu, Guo-Liang   Li, Zhen-Yu   Wang, Zhi-Gang  

    In this article, we calculate the form factors and the coupling constant of the vertex D-s*D-s phi using the three-point QCD sum rules. We consider the contributions of the vacuum condensates up to dimension 7 in the operator product expansion. And all possible off-shell cases are considered, phi, D-s and D-s*, resulting in three different form factors. Then we fit the form factors into analytical functions and extrapolate them into time-like regions, which giving the coupling constant for the process. Our analysis indicates that the coupling constant for this vertex is G(Ds*Ds phi) =3D 4.12 +/- 0.70 GeV-1. The results of this work are very useful in the other phenomenological analysis. As an application, we calculate the coupling constant for the decay channel D-s* -> D-s gamma and analyze the width of this decay with the assumption of the vector meson dominance of the intermediate phi(1020). Our final result about the decay width of this decay channel is Gamma =3D 0.59 +/- 0.15 keV.
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  • Effect of POE-g-GMA on mechanical,rheological and thermal properties of poly(lactic acid)/poly(propylene carbonate) blends

    Zhou, Ye   Wang, Jiao   Cai, Shen-Yang   Wang, Zhi-Gang   Zhang, Nai-Wen   Ren, Jie  

    Glycidyl methacrylate (GMA) functionalized polyolefin elastomers (POE) (POE-g-GMA), which was a reactive processing agent, was melt-blended with poly(lactic acid) (PLA) and poly(propylene carbonate) (PPC) by twin-screw extrusion. The mechanical property results showed that with the addition of POE-g-GMA, the elongation at break and impact toughness of PLA/PPC blends increased while the tensile strength decreased. Dynamic thermomechanical analysis (DMA) and scanning electron microscope (SEM) results indicated that PLA/POE-g-GMA/PPC blends were partly miscible and the addition of POE-g-GMA improved the compatibility of blends. The higher T-cs and lower T-ms of PLA/POE-g-GMA/PPC blends showed a depressed crystalline ability of PLA caused by the decreased chain mobility according to the differential scanning calorimetry results and the thermal stability of PLA/POE-g-GMA/PPC blends was enhanced. Rheological results revealed that the addition of POE-g-GMA made the storage modulus (G'), loss modulus (G '') and complex viscosity of the blends increase, the melt strength also improved. These findings contributed to the biodegradable materials application for designing and manufacturing PLA film.
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  • Analysis of the vector form factors f(K pi)(+)(Q(2)) and f(K pi)(-)(Q(2)) with light-cone QCD sum rules

    Wang, Zhi-Gang   Wan, Shao-Long  

    In this article, we calculate the vector form factors f(K pi)(+)(Q(2)) and f(K pi)(-)(Q(2)) within the framework of the light-cone QCD sum rule approach. The numerical values of f(K pi)(+)(Q(2)) are compatible with existing theoretical calculations, and the central value of f(K pi)(+)(0) (f(K pi)(+)(0) = 0.97) is in excellent agreement with the values from chiral perturbation theory and lattice QCD. The values of vertical bar f(K pi)(-)(0)vertical bar are very large compared to the theoretical calculations and experimental data, and they cannot give any reliable prediction. At large momentumtransfer with Q(2) > 5GeV(2), the form factors f(K pi)(+)(Q(2)) and vertical bar f(K pi)(-)(Q(2))vertical bar can either show the asymptotic behavior of 1/Q(2) or decrease more quickly than 1/Q(2); more experimental data are needed to select the ideal sum rules.
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