Positive temperature coefficient of resistivity effects of semiconducting (Bi1/2Na1/2) TiO3-CaTiO3-BaTiO3 ceramics sintered in air atmosphere

Y3+-doped (Bi1/2Na1/2)TiO3-CaTiO3-BaTiO3 (BNCBT) positive temperature coefficient of resistivity (PTCR) ceramics sintered in air atmosphere were investigated in this study. (Bi1/2Na1/2) TiO3 (BNT) component can remarkably increase the onset temperature Tc of PTCR ceramics with the expensive of the resistivity R25 increase. CaTiO3 (9-27 mol%) component can decrease the resistivity, and adjust the effects of BNT phase on the Tc point. For the sample containing 3 mol% CaTiO3, the Tc raises from 122° to 153° when only 0.6 mol% BNT added, while for the ones with higher CaTiO3 content (9-27 mol%), Tc is only increased by a rate of 8-9°/1.0 mol% BNT. The effects of BNT and CaTiO3 components on Rmln (negative temperature coefficient effect) are also discussed.     

Berbamine induces apoptosis in human hepatoma cell line SMMC7721 by loss in mitochondrial transmembrane potential and caspase activation

Objective： To investigate the effect ofberbamine on human hepatoma cell line SMMC7721. Methods： The effects of 24 h and 48 h incubation with different concentrations （0-64 μg/ml） of the berbamine on SMMC7721 cells were evaluated using 3-4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide （MTT） assay. Hoechst 33258 staining was conducted to distinguish the apoptotic cell, and the appearance of sub-G1 stage was determined by PI （propidium iodide） staining, the percentage of apoptotic cell was determined by flow cytometry following annexin V/PI staining. Flow cytometry was performed to analyze the cell cycle distribution and the mitochondrial membrane potential （△ψm）, the expression of activated caspase3 and caspase9 was analyzed by Western-blot. Results： The proliferation of SMMC7721 was decreased after treatment with berbamine in a dose- and time-dependent manner. Berbamine could induce apoptosis in SMMC7721 cells and could cause cell cycle arrest in G0/G1 phase, to induce loss of mitochondrial membrane potential （AVm） and activate caspase3 and caspase9. Berbamine-induced apoptosis could be blocked by the broad caspase inhibitor z-VAD-fmk. Conclusion： Berbamine exerts antiproliferative effects on human hepatocellular carcinoma SMMC7721 cells. The anticancer activity of berbamine could be attributed partly to its inhibition of cell proliferation and induction of apoptosis in cancer cells through loss in mitochondrial transmembrane potential and caspase activation.     

Molecular pathogenesis of acetaminophen-induced liver injury and its treatment options

Acetaminophen, also known as N-acetyl-p-aminophenol (APAP), is commonly used as an antipyretic and analgesic agent. APAP overdose can induce hepatic toxicity, known as acetaminophen-induced liver injury (AILI). However, therapeutic doses of APAP can also induce AILI in patients with excessive alcohol intake or who are fasting. Hence, there is a need to understand the potential pathological mechanisms underlying AILI. In this review, we summarize three main mechanisms involved in the pathogenesis of AILI: hepatocyte necrosis, sterile inflammation, and hepatocyte regeneration. The relevant factors are elucidated and discussed. For instance, N-acetyl-p-benzoquinone imine (NAPQI) protein adducts trigger mitochondrial oxidative/nitrosative stress during hepatocyte necrosis, danger-associated molecular patterns (DAMPs) are released to elicit sterile inflammation, and certain growth factors contribute to liver regeneration. Finally, we describe the current potential treatment options for AILI patients and promising novel strategies available to researchers and pharmacists. This review provides a clearer understanding of AILI-related mechanisms to guide drug screening and selection for the clinical treatment of AILI patients in the future.

     

砷剂对K_(562)细胞凋亡作用的基础研究

[目的]研究三氧化二砷对K562细胞凋亡的诱导.[方法]采用人红白血病细胞株K562细胞常规培养,给不同浓度的三氧化二砷,在不同的时间收获细胞,用台盼蓝排染法,DNA荧光染料Hoechst33342荧光染色法,及碘化丙啶(PI)与Hoechst33342共染计数坏死细胞的PI阳性率等方法,检测其对K562细胞的影响.[结果]三氧化二砷能够诱导K562细胞凋亡.并且呈现浓度依赖性和时间依赖性.[结论]三氧化二砷主要以诱导肿瘤细胞凋亡而表现其毒性作用.     

Investigation on apoptosis of neuronal cells induced by Amyloid beta-Protein

Objective: To construct a PC12 cell strain with neuronal differentiation, and observe the apoptosis and pro-liferation activity effects induced these cells by Amyloid beta-Protein (Aβ-43). Methods: 1) PC12 cells in logarithmicgrowth phase were subcultured for 24 h. After the culture fluid was changed, the cells were treated with Rat-β-NGF andcultured for 9 days. 2) Neuronal differentiation of PC12 cells in logarithmic growth phase were divided into four groups:control group (0), experimental group (1), experimental group (2) and experimental group (3). The concentrations of Aβ inthe four groups were 0 μmol/L, 1.25 μ mol/L, 2.5 μ mol/L and 5 μmol/L, respectively. The cells were harvested at 24, 48 and72 h later and stained with AnnexinV-FITC/PI after centrifugation and washing. Then flow cytometry was conducted toexamine the apoptosis percentage. 3) NGF-induced PC12 cells were selected and Aβ with different concentrations wasadded. The final concentrations of Aβ were 0 μmol/L, 1.25 μmol/L, 2.5 μmol/L and 5 μ mol/L, respectively. After the cellswere incubated in an atmosphere of 5% CO2 at 37 ℃ in an incubator for 72 h, the OD values were examined. Results: 1)Neuronal differentiated PC 12 cell lines were successfully established. 2) Flow cytometric examination indicated that Aβ(1.25, 2.5, and 5.0 μmol/L) could effectively induce apoptosis of neuronal-differented cells at the 24 h, 48 h and 72 h timepoints. 3) Aβ (0-5.00 μ mol/L) had no obvious effect on proliferation or restraining of the neuronal differentiation of thePC 12 cells after a 72 h interacting process. Conclusion: This investigation revealed successful neuronal differentiation of thePC12 cell strain. The induction of apoptosis of the neurocytes by various concentrations of Aβ was observed and the in-fluence of Aβ on induced proliferation of PC 12 cells by Rat-β-NGF was revealed. This study -05 provide basis for futureresearch on the molecular cure of AD and interdiction of AD evolution.     

New developments in small molecular compounds for anti-hepatitis C virus (HCV) therapy

Infection with hepatitis C virus (HCV) affects approximately 170 million people worldwide. However, no vaccine or immunoglobulin is currently available for the prevention of HCV infection. The standard of care (SOC) involving pegylated interferon-α (PEG-IFN α) plus ribavirin (RBV) for 48 weeks results in a sustained virologic response in less than 50% of patients with chronic hepatitis C genotype 1, the most prevalent type of HCV in North America and Europe. Recently, reliable in vitro culture systems have been developed for accelerating antiviral therapy research, and many new specifically targeted antiviral therapies for hepatitis C (STAT-C) and treatment strategies are being evaluated in clinical trials. These new antiviral agents are expected to improve present treatment significantly and may potentially shorten treatment duration. The aim of this review is to summarize the current developments in new anti-HCV drugs.     

Short Report： Cyclic patterns of incidence rate for skin malignant melanoma： association with heliogeophysical activity

Background: Our previous studies revealed cyclicity in the incidence rate of skin malignant melanoma (SMM; ICD9, Dx: 172) in the Czech Republic (period T=7.50～7.63 years), UK (T=11.00 years) and Bulgaria (T=12.20 years). Incidences com-pared with the sunspot index Rz (lag-period dT= 2, 4, 6, 10 or 12 years) have indicated that maximal rates are most likely to appear on descending slopes of the 11-year solar cycle, i.e., out of phase. We summarized and explored more deeply these cyclic variations and discussed their possible associations with heliogeophysical activity (HGA) components exhibiting similar cyclicity. Methods: Annual incidences of SMM from 5 countries (Czech Republic, UK, Bulgaria, USA and Canada) over various time spans during the years 1964～1992 were analyzed and their correlations with cyclic Rz (sunspot number) and aa (planetary geomagnetic activity) indices were summarized. Periodogram regression analysis with trigonometric approximation and phase-correlation analysis were applied. Results: Previous findings on SMM for the Czech Republic, UK and Bulgaria have been validated, and cyclic patterns have been revealed for USA (T=8.63 years, P<0.05) and Canada (Ontario, T=9.91 years, P<0.10). Also, various 'hypercycles' were established (T=45.5, 42.0, 48.25, 34.5 and 26.5 years, respectively) describing long-term cyclic incidence patterns. The association of SMM for USA and Canada with Rz (dT= 6 and 7 years, respectively) and aa (dT=-10 and 9 years, respectively) was described. Possible interactions of cyclic non-photic influences (UV irradiation, Schumann resonance signal, low-frequency geomagnetic fluctuations) with brain waves absorbance, neuronal calcium dynamics, neuro-endocrine axis modulation, melatonin/serotonin disbalance and skin neuro-immunity impairment as likely causal pathways in melanoma appearance, were also discussed. Conclusion: The above findings on cyclicity and temporal association of SMM with cyclic environmental factors could not only allow for better forecasting models but also lead to a better understanding of melanoma aetiology.     

金属表面自组装成膜的机理研究——苯硫醇在Au（100）表面的吸附

通过分子力学和分子动力学模拟,对我们已发表的苯硫醇在Au（100）上吸附的扫描隧道显微镜结果进行了模拟.根据STM结果,苯硫醇在Au（100）表面形成（√2×√5）的结构,最小重复单元为Au（100）-（√2×√5）的-1BT.分子模拟结果表明,BT分子之间存在相互作用,导致邻近的BT分子方向发生变化.如果考虑分子方向的变化,得到的最小重复单元应该是Au（100）-（√2×3√2）-2BT.（√2×√5）的结构是一个平行四边形,相邻两边的夹角为75°或105°;（√2×3√2）结构是一个矩形,相邻两边的夹角为90°.在重复单元Au（100）-（√2×√5）的-1BT和Au（100）-（√2×3√2）-2BT中,苯硫醇的覆盖度都是0.33.通过分子模拟结果与STM实验结果的比较,证明分子模拟结果可以作为实验的一种重要补充,有助于进一步揭示金属表面缓蚀功能膜自组装的机理.     

Edaravone protects PC12 cells from ischemic-like injury via attenuating the damage to mitochondria

Background： Edaravone had been validated to effectively protect against ischemic injuries. In this study, we investigated the protective effect of edaravone by observing the effects on anti-apoptosis, regulation of Bcl-2/Bax protein expression and recovering from damage to mitochondria after OGD （oxygen-glucose deprivation）-reperfusion. Methods： Viability of PC 12 cells which were injured at different time of OGD injury, was quantified by measuring MTT （2-（4,5-dimethylthia-zol-2-yl）-2,5-diphenyltetrazolium bromide） staining. In addition, PC 12 cells＇ viability was also quantified after their preincubation in different concentration of edaravone for 30 min followed by （OGD）. Furthermore, apoptotic population of PC 12 cells that reinsulted from OGD-reperfusion with or without preincubation with edaravone was determined by flow cytometer analysis, electron microscope and Hoechst/Pl staining. Finally, change of Bcl-2/Bax protein expression was detected by Western blot. Results： （1） The viability of PC12 cells decreased with time （1-12 h） after OGD. We regarded the model of OGD 2 h, then replacing DMEM （Dulbecco＇s Modified Eagle＇s Medium） for another 24 h as an OGD-reperfusion in this research. Furthermore, most PC 12 cells were in the state of apoptosis after OGD-reperfusion. （2） The viability of PC 12 cells preincubated with edaravone at high concentrations （1, 0.1, 0.01 μmol/L） increased significantly with edaravone protecting PC 12 cells from apoptosis after OGD-reperfusion injury. （3） Furthermore, edaravone attenuates the damage of OGD-reperfusion on mitochondria and regulated Bcl-2/Bax protein imbalance expression after OGD-reperfusion. Conclusion： Neuroprotective effects of edaravone on ischemic or other brain injuries may be partly mediated through inhibition of Bcl-2/Bax apoptotic pathways by recovering from the damage of mitochondria.     

In vitro study on ribozyme against hepatitis C virus

Objective: To determine the effective nucleotide sites of ribozymes against HCV, and obtain a highly effective, nontoxic and inexpensive antisense ribozyme specific for HCV. Methods: Two effective ribozymes, targeted to HCV 5’NC region and C region, were designed and synthesized. Eukaryotic expression vectors, pSV2-gpt. CD-SR (, containing either HCRZNC or HCRZC were constructued and transfected into MT-2 cells, which had been infected by HCV. Quantitative PCR and hydridization were used to determine the effect of inhibition of HCV by ribozymes. Results: HCRZNC and HCRZC suppressed the replication of HCV by 54.7% and 62.1%, respectively. Furthermore, when both ribozymes were cotransfected into cells, they suppressed replication by 78.8%. Conclusion: Two specific antisense ribozymes have strong inhibitory effects on the replication of HCV in cultured cells, and have better effect when used together.     

高校双语教学现状分析及建议

通过对重庆高校双语教学现状的分析,双语教学的重要性凸显出来,主要体现在三个方面：为国家培养21世纪新型复合型人才;为学生今后出国继续深造做好准备,使其更具国际竞争力;让教、学双方及时了解学科领域最前沿的理论和最新的学术成果。在此基础上,提出了四点建议。     

慢性肝炎病毒感染致病机制相关新基因克隆化研究策略

乙型肝炎病毒(HBV)和丙型肝炎病毒(HCV)的慢性感染,与慢性病毒性肝炎、肝硬化、肝细胞癌(HCC)的发病密切相关,其发病机理涉及到很多基因的共同参与.病毒基因的复制和表达受到肝细胞中蛋白质因子的调节,肝炎病毒基因编码的蛋白与肝细胞中的蛋白能够结合,肝炎病毒蛋白在肝细胞中的表达对于肝细胞的基因表达谱产生影响,也可能是病毒性肝炎、肝硬化、肝细胞癌发病机制的重要机制.酵母单杂交技术、酵母双杂交技术、基因芯片技术、抑制性消减杂交技术、噬菌体展示技术、蛋白质分离纯化与基因克隆化的反向遗传学技术等,在肝炎病毒基因调控、肝炎病毒蛋白结合蛋白的研究、肝炎病毒蛋白反式激活靶基因的研究中都有重要的应用,是促进慢性病毒性肝炎发病机理研究,探索病毒性肝炎新型治疗技术和治疗方法的有效途径.     

Chlorella vulgaris triggers apoptosis in hepatocarcinogenesis-induced rats

Chlorella vulgaris (CV) has been reported to have antioxidant and anticancer properties. We evaluated the effect of CV on apoptotic regulator protein expression in liver cancer-induced rats. Male Wistar rats (200-250 g) were divided into eight groups: control group (normal diet), CDE group (choline deficient diet supplemented with ethionine in drinking water to induce hepatocarcinogenesis), CV groups with three different doses of CV (50, 150, and 300 mg/kg body weight), and CDE groups treated with different doses of CV (50, 150, and 300 mg/kg body weight). Rats were sacrificed at various weeks and liver tissues were embedded in paraffin blocks for immunohistochemistry studies. CV, at increasing doses, decreased the expression of anti-apoptotic protein, Bcl-2, but increased the expression of pro-apoptotic protein, caspase 8, in CDE rats, which was correlated with decreased hepatoctyes proliferation and increased apoptosis as determined by bromodeoxy-uridine (BrdU) labeling and terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) assay, respectively. Our study shows that CV has definite chemopreventive effect by inducing apoptosis via decreasing the expression of Bcl-2 and increasing the expression of caspase 8 in hepatocarcinogenesis-induced rats.     

He—Ne激光诱导HL-60细胞凋亡

探讨He—Ne激光幅照诱导肿瘤细胞凋亡而抑制肿瘤的生长。采用He—Ne激光处理HL-60细胞,流式细胞仪检测DNA含量及细胞凋亡百分率。发现在57．24J／cm^2的He—Ne激光作用下,HL-60细胞的凋亡百分率为12．83％。同时细胞周期发生改变,G1期减少,S期降低,G2期增加。结果表明在一定剂量He—Ne激光照射下,导致细胞DNA断裂,诱导HL-60细胞凋亡并抑制肿瘤细胞生长。     

IN VITRO STUDY ON RIBOZYME AGAINST HEPATITIS C VIRUS

ＩＮＴＲＯＤＵＣＴＩＯＮＲｉｂｏｚｙｍｅｗａｓｆｉｒｓｔｄｅｓｃｒｉｂｅｄｂｙＣｅｃｈａｎｄＡｌｔｍａｎｉｎ 1 981 .ＴｈｉｓｆｏｒｍｏｆＲＮＡｈａｄｈｉｇｈｌｙｓｐｅｃｉｆｉｃｅｎｄｏｎｕｃｌｅａｓｅａｃｔｉｖｉｔｉｅｓｔｏＲＮＡ (Ｋｒｕｇｅｒｅｔａｌ.,1 982 ) .Ｒｉｂｏｚｙｍｅｓｈａｖｅｔｈｒｅｅｓｔｒｕｃｔｕｒｅｓ:ｈａｍｍｅｒｈｅａｄ ,ｈａｉｒｐｉｎａｎｄａｘｅｒｉｂｏｚｙｍｅｓ.Ａｍｏｎｇｔｈｅｍ ,ｔｈｅｈａｍｍｅｒｈｅａｄｒｉｂｏｚｙｍｅｈａｓａｓｉｍｐｌｅｒｓｅｃｏｎｄａｒｙｓｔｒｕｃ…     

肺康饮含药血清诱导肺癌细胞凋亡的实验研究

目的:探讨肺康饮含药血清对人肺癌细胞(NC-H446)的作用。方法:采用血清药理学方法,以细胞增殖抑制率及凋亡率为观察指标,对实验结果进行分析。结果:肺康饮含药血清培养24h、48h,均对NC-H446细胞株增殖具有抑制作用,且对NC-H446细胞株增殖的抑制作用具有一定的量效及时效关系,实验组与对照组间差异有统计学意义(P<0.01)。各实验组含药血清均可诱导NC-H446细胞株发生凋亡,且该作用具有一定的量效及时效关系,实验组与对照组间差异有统计学意义(P<0.01)。结论:肺康饮含药血清可明显抑制NC-H446细胞株的增殖,抑制作用具有一定的量效及时效关系。肺康饮含药血清也可诱导NC-H446细胞株发生凋亡,作用具有一定的量效及时效关系。     

OP-ED The 'academic problem'

Hamlet : The time is out of joint; O cursed spite That ever I was born to set it right! Nay, come; let's go together (Hamlet, Act I, scene v, lines 189-191).     

丙型肝炎病毒包膜蛋白的研究近况

丙型病毒性肝炎由丙型肝炎病毒感染所致。HCV感染呈全球性分布,我国是高流行地区,其所具有较高的慢性化程度使之成为威胁人类健康的重要疾病。近年来,报道了很多丙型肝炎病毒的相关研究,本文主要讨论HCV包膜蛋白的结构、免疫状况及疫苗研究实验模型的相关研究。