An animal model of cerebral palsy induced by prenatal exposure to lipopolysaccharide and hypoxia

BACKGROUND： Neonatal cerebral palsy is mainly caused by prenatal factors. At present, an animal model of prenatal infection and early postnatal hypoxia does not exist. OBJECTIVE： To observe morphology and motor performance following prenatal infection and hypoxic insult-induced brain damage of neonatal rats to verify the feasibility to establish a model of cerebral palsy. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Laboratories of Xinjiang Center for Disease Control and Prevention from September 2007 to June 2008. MATERIALS： The hypoxic incubator was purchased from Shanghai Pediatric Medical Institute, China. Lipopolysaccharide （LPS, Escherichia coil, 055： B5） was purchased from Sigma-Aldrich （St. Louis, MO, USA）. METHODS： A total of 27 Wistar rats, aged 7 days, were randomly assigned to sham-surgery group （n = 15） with no carotid artery incision or hypoxia treatment, hypoxia/ischemia （H/I） group （n = 12） undergoing ligature of the right common carotid artery followed by exposure to hypoxia at postnatal day 7 （P7）, and LPS/H group （n = 19）, in which pregnant rats were exposed in utero to LPS followed by prenatal hypoxia at embryonic day 16. MAIN OUTCOME MEASURES： Behavior, compound muscle action potential, and pathological changes were observed in 28-day-old rats. RESULTS： The footprint repeat space showed that left limb footprint repeatability in the H/I and LPS/H groups was lower than in the sham-surgery group （P 〈 0.05）. The space between the footprints was larger and unstable. Hind limb quadricep compound muscle action potential in the H/I and LPS/H groups showed lower wave amplitude compared with the sham-surgery group （P〈 0.05） Hematoxylin and eosin staining showed irregular cells around the ventricle, as well as periventricular leukomalacia. CONCLUSION： An animal model of cerebral palsy was established, which simulated the human condition most likely associated with occurrence of this disease. This model could be used for experimental studies related to cerebral palsy.

Regulating adsorption ability toward polysulfides in a porous carbon/Cu_(3)P hybrid for an ultrastable high-temperature lithium-sulfur battery

Lithium-sulfur batteries(LSBs)can work at high temperatures,but they suffer from poor cycle life stability due to the“shuttle effect”of polysulfides.In this study,pollen-derived porous carbon/cuprous phosphide(PC/Cu_(3)P)hybrids were rationally synthesized using a one-step carbonization method using pollen as the source material,acting as the sulfur host for LSBs.In the hybrid,polar Cu_(3)P can markedly inhibit the“shuttle effect”by regulating the adsorption ability toward polysulfides,as confirmed by theoretical calculations and experimental tests.As an example,the camellia pollen porous carbon(CPC)/Cu_(3)P/S electrode shows a high capacity of 1205.6 mAh g^(−1) at 0.1 C,an ultralow capacity decay rate of 0.038%per cycle after 1000 cycles at 1 C,and a rather high initial Coulombic efficiency of 98.5%.The CPC/Cu_(3)P LSBs can work well at high temperatures,having a high capacity of 545.9 mAh g^(−1) at 1 C even at 150℃.The strategy of the PC/Cu_(3)P hybrid proposed in this study is expected to be an ideal cathode for ultrastable high-temperature LSBs.We believe that this strategy is universal and worthy of in-depth development for the next generation energy storage devices.

中国新诊断胶质母细胞瘤患者实际治疗方案与Stupp方案的一致性比较

目的评估中国新诊断胶质母细胞瘤(glioblastoma multiforme,GBM)患者实际接受的治疗方案与指南推荐的Stupp方案的一致性。方法纳入202例新诊断GBM患者,评估实际接受的治疗方案与Stupp方案一致的患者比例,以及不符合Stupp方案的原因。结果研究发现,仅15.8%的GBM患者接受了与Stupp方案一致的治疗。治疗方案的不一致主要是由于同步放化疗阶段替莫唑胺剂量>75 mg/m^(2)(58/120;48.3%)和治疗持续时间<42 d(84/120;70.0%),以及辅助治疗阶段替莫唑胺剂量<150 mg/m^(2)(89/101;88.1%)。接受符合Stupp方案治疗的患者的中位总生存期(27.09 vs 18.21个月)和无进展生存期(14.27 vs 12.10个月)更长。结论需要提高中国GBM患者实际接受的治疗方案与Stupp方案的一致性。

减毒沙门氏菌介导的NK4基因对HepG2细胞致癌作用的影响(英文)

Objective:The aim of the study was to construct a stable strain of recombined attenuated Salmonella typhimurium expressing NK4 gene,and observe the effect of the strain on the metastatic potentiality of HepG2 cells.Methods:The NK4 cDNA was isolated from PCAGGS/hNK4 plasmid by PCR,and subcloned into eukaryotic expression vector pcDNA4.The recombinant plasmid was electro-transferred into attenuated Salmonella typhimurium Ty21a to obtain the recombinant strain encoding NK4 gene(TPN).Simultaneously,the recombinant attenuated Salmonella typhimurium carrying GFP gene(TPG) was also constructed.After the TPG and TPN were transferred into HepG2 cells,the transfection rate and the expression level of NK4 protein were detected by flow cytometry and ELISA,and the effects of expression product on the proliferation and migration of HepG2 and angiogenesis were observed.Results:The TPN and TPG were successfully constructed.Fortyeight hours after transfection with TPG,the infection rate was 82.58% ± 1.74%,and the expression level of NK4 protein in supernatant was(181.5 ± 11.7) ng/6 × 105 cells.The supernatant had obviously depressant effect on the proliferative activity of HepG2 cells(P < 0.05),and could obviously restrain the hepatocyte growth factor-mediated migration of tumor cells(P < 0.01).The inhibitory effect of the expression product on the tumor angiopoiesis was obviously observed(P < 0.05),without a dosage-effect relation.Conclusion:The TPN could effectively transfer tumor cells in vitro and express interest NK4 protein.The expression product could effectively inhibit the proliferation and migration of hepatocellular carcinoma cells and the tumor angiopoiesis.

Review of flexible microelectromechanical system sensors and devices

Today,the vast majority of microelectromechanical system(MEMS)sensors are mechanically rigid and therefore suffer from disadvantages when used in intimately wearable or bio-integrated applications.By applying new engineering strategies,mechanically bendable and stretchable MEMS devices have been successfully demonstrated.This article reviews recent progress in this area,focusing on high-performance flexible devices based on inorganic thin films.We start with the common design and fabrication strategies for flexibility and stretchability,summarize the recent application-oriented flexible devices,and conclude with criteria and opportunities for the future development of flexible MEMS sensors.

Elastic buckling analysis and optimization of thin-walled bamboo-like pipe beam subjected to pure bending

In this paper,a stiffening design imitating the bamboo node is proposed for weight reduction of the long composite pipe beam subjected to bending load.The distribution of bamboo nodes can efficiently suppress the ovalization of the section,thus significantly improving the bending resistance of the bamboo.Based on this principle,ring stiffeners are proposed to be fixed to the pipe beam,making the long beam equivalent to the combination of a series of short pipes that suffered less section ovalization.A database of the optimal laminate orientations for different normalized lengths is obtained through optimizations,where the discreteness of the ply count is considered.Based on this database,weight optimizations are conducted,and the optimal designs of beams with and without stiffeners are obtained and compared.The comparison results show that the proposed bamboo-like stiffened beam not only regains a near-linear load–displacement relationship,but also reduces the weight by up to 16%under the same buckling load.In addition,it is found that for the pipe beams with radius-to-thickness ratios of more than 18,increasing the radius leads to a decrease in elastic buckling resistance when the weight remains a constant,which is opposite to the design for strength and stiffness.The model and database developed in this paper can provide a reference for weight reduction design and weight estimation for composite pipe beams.