Human immunodeficiency virus Env-independent infection of human CD4(-) cells

CD4(-) epithelial cells covering mucosal surfaces serve as the primary barrier to prevent human immunodeficiency virus type 1 (HIV-1) infection. We used HIV-1 vectors carrying the enhanced green fluorescent protein gene as a reporter gene to demonstrate that HIV-1 can infect some CD4(-) human epithelial cell lines with low but significant efficiencies. Importantly, HIV-1 infection of these cell lines is independent of HIV-1 envelope proteins. The Env-independent infection of CD4(-) cells by HIV-1 suggests an alternative pathway for HIV-1 transmission. Even on virions bearing Env, a neutralizing antibody directed against gp120 is incapable of neutralizing the infection of these cells, thus raising potential implications for HIV-1 vaccine development.     

Involvement of Ca2+ in 1-Aminocyclopropane-1-Carboxylic Acid-Stimulated Pollen Germination

The role of 1-aminocyclopropane-1-carboxylic acid (ACC) in pollen germination was investigated in several plant species. It was found that ACC stimulated in vitro pollen germination in all five species of plants tested. EGTA and phenothiazine inhibited the increase in the germination rate induced by ACC. Free Ca²⁺ levels in the cytosol ([Ca²⁺]_cyt) in ungerminated and germinated pollen were 136 and 287 nm, respectively. Adding 0.25 mm ACC to the germination medium increased the [Ca²⁺]_cyt in germinated pollen up to 450 nm. When pollen was treated with both 0.25 mm ACC and 3.6 μm inositol 1,4,5-trisphosphate, the [Ca²⁺]_cyt increased to 850 nm, and pollen germination was also stimulated. In the presence of Li⁺, an inhibitor of inositol monophosphatase, the [Ca²⁺]_cyt was reduced to 155 nm, and the ACC-stimulated pollen germination was inhibited. The data provided evidence for the involvement of Ca²⁺ as a messenger in the stimulative effect of ACC on pollen germination. Received December 1, 1995; accepted February 18, 1998     

疼痛患者脊髓脑脊液中强啡肽含量的分析

本文观察了疼痛患者脊髓脑脊液中强啡肽含量的变化。共收集３１例急性疼痛患者和１４例慢性疼痛患者的脊髓脑脊液,测定其中的强啡肽含量,与２７例无痛患者的结果进行比较,并结合被测者的性别、年龄、体重、血压、脉搏、体温等一般情况进行分析。结果表明,慢性痛患者脑脊液中强啡肽含量显著升高,而急性痛患者则略有降低。判别分析表明,急性痛患者的强啡肽含量及其他临床资料有明显的特点（判别准确率８２％）;慢性痛患者未见明显特征。作者认为,在更广泛地收集临床资料和检验结果的基础上,进一步研究不同病因的疼痛患者的临床特征,可能有助于对疼痛疾病进行鉴别诊断     

美国蓝浆果的引种

１９８８年由美国引入１２个兔眼蓝浆果（ＶａｃｉｎｉｕｍａｓｈｅｉＲｅａｄｅ）品种,在江苏南京和溧水两地试种。１０年来生长结果正常,产量和品质与原产地无显著差异,引种获得成功,证明兔眼蓝浆果能适应本地区自然条件。单株产量平均７．５１ｋｇ,品种间差异显著,最高９．８６ｋｇ,最低１３４ｋｇ。单位投影面积产量３．１０ｋｇ／ｍ２,最高４．０６ｋｇ／ｍ２,最低１．１３ｋｇ／ｍ２。高于或至少不低于原产区产量记录。据此预测,栽植距离适宜时,在本地区亩产量可达１５００～２０００ｋｇ以上。大多数品种果实糖酸比很高,鲜食风味好,氨基酸含量中等,矿质元素Ｚｎ和Ｓｅ含量高。兔眼蓝浆果可在江苏南部丘陵地区发展;此外,还应将试验扩大到南方红黄壤地区;并对本国野生资源开展研究和利用。     

水稻(Oryza sativa)原生质体经钝化后诱导融合再生可育体细胞杂种

本研究在初步实现水稻原生质体培养的程序化后,选用普通栽培稻P339和特种稻苏御糯选的原生质体为融合亲本,利用碘乙酸(IA)和罗丹明-6G(R-6G)这两个代谢互补抑制剂钝化处理亲本原生质体,确定了合适的抑制条件。P339用0.25mmol/L IA,苏御糯选用50μg/ml R-6G分别经30min钝化处理,通过PEG和高Ca~(2 )、高pH法诱导融合,异源融合体具有代谢互补效应,经培养得到愈伤组织17块,并进一步分化获得不同形态的再生植株12棵。移栽存活的再生植株成熟后可育,通过对这些植株的形态以及酯酶和过氧化物酶同工酶电泳的分析表明是融合后的体细胞杂种植株。     

An instrumented wheel for kinetic analysis of wheelchair propulsion.

An instrumented wheel system for three-dimensional kinetic analysis of upper extremity during wheelchair propulsion has been designed and validated. This system allows the direct measurements of three-dimensional dynamic forces and moments on the handrim during wheelchair propulsion in a laboratory setting as well as in the field. Static loading tests showed a high linearity and little drift (coefficient of determination, r2 > 0.999). Under dynamic loading, the instrumented wheel provided the well-matched measurement forces and moments with the predicted values from the inverse dynamic method using video-based kinematic data (correlation coefficient, p > 0.97). The three-dimensional handrim forces and moments during wheelchair propulsion by a non-disabled subject were demonstrated.     

Nanoflake‐Assembled Hierarchical Na3V2(PO4)3/C Microflowers: Superior Li Storage Performance and Insertion/Extraction Mechanism

Na₃V₂(PO₄)₃ (NVP) has excellent electrochemical stability and fast ion diffusion coefficient due to the 3D Na⁺ ion superionic conductor framework, which make it an attractive cathode material for lithium ion batteries (LIBs). However, the electrochemical performance of NVP needs to be further improved for applications in electric vehicles and hybrid electric vehicles. Here, nanoflake‐assembled hierarchical NVP/C microflowers are synthesized using a facile method. The structure of as‐synthesized materials enhances the electrochemical performance by improving the electron conductivity, increasing electrode–electrolyte contact area, and shortening the diffusion distance. The as‐synthesized material exhibits a high capacity (230 mAh g^?1), excellent cycling stability (83.6% of the initial capacity is retained after 5000 cycles), and remarkable rate performance (91 C) in hybrid LIBs. Meanwhile, the hybrid LIBs with the structure of NVP || 1 m LiPF₆/EC (ethylene carbonate) + DMC (dimethyl carbonate) || NVP and Li₄Ti₅O₁₂ || 1 m LiPF₆/EC + DMC || NVP are assembled and display capacities of 79 and 73 mAh g^?1, respectively. The insertion/extraction mechanism of NVP is systematically investigated, based on in situ X‐ray diffraction. The superior electrochemical performance, the design of hybrid LIBs, and the insertion/extraction mechanism investigation will have profound implications for developing safe and stable, high‐energy, and high‐power LIBs.     

基因重组TNFα衍生物TRSP10的高效制备及其对DU145细胞抑制作用研究

利用基因工程技术表达能够促使肿瘤细胞DU145凋亡的肿瘤坏死因子α(TNFα)的衍生物TRSP10,并在体外研究其对DU145细胞的抑制效应。以重叠延伸PCR方法合成TRSP10基因序列,并插入高效表达的质粒载体p KYB-MCS的NdeⅠ和SapⅠ酶切位点之间,优化融合蛋白诱导表达的条件,建立了从载体构建到重组菌表达、制备的工艺技术条件。MTT法检测TRSP10对前列腺癌细胞DU145增殖的抑制作用。实验结果表明:重组菌ER2566诱导表达可溶性融合蛋白的最佳条件是诱导剂IPTG浓度为0.8 mmol/L、诱导表达温度37℃、诱导表达时间8h。利用IMPACT系统及HPLC技术纯化制备TRSP10,得到产物纯度达到96%,质谱鉴定确定其分子质量为3.59k Da,与理论值相符;体外细胞学研究结果表明,TRSP10对前列腺癌细胞DU145有明显的抑制作用,在5,10,20,40μmol/L TRSP10及10μmol/L TNFα阳性对照处理后48h抑制率分别达到11.40%,22.97%,33.26%,48.35%及42.50%。     

Mutation of Oryza sativa CORONATINE INSENSITIVE 1b (OsCOI1b) delays leaf senescence

Jasmonic acid (JA) functions in plant development, including senescence and immunity. Arabidopsis thaliana CORONATINE INSENSITIVE 1 encodes a JA receptor and functions in the JA‐responsive signaling pathway. The Arabidopsis genome harbors a single COI gene, but the rice (Oryza sativa) genome harbors three COI homologs, OsCOI1a, OsCOI1b, and OsCOI2. Thus, it remains unclear whether each OsCOI has distinct, additive, synergistic, or redundant functions in development. Here, we use the oscoi1b‐1 knockout mutants to show that OsCOI1b mainly affects leaf senescence under senescence‐promoting conditions. oscoi1b‐1 mutants stayed green during dark‐induced and natural senescence, with substantial retention of chlorophylls and photosynthetic capacity. Furthermore, several senescence‐associated genes were downregulated in oscoi1b‐1 mutants, including homologs of Arabidopsis thaliana ETHYLENE INSENSITIVE 3 and ORESARA 1, important regulators of leaf senescence. These results suggest that crosstalk between JA signaling and ethylene signaling affects leaf senescence. The Arabidopsis coi1‐1 plants containing 35S:OsCOI1a or 35S:OsCOI1b rescued the delayed leaf senescence during dark incubation, suggesting that both OsCOI1a and OsCOI1b are required for promoting leaf senescence in rice. oscoi1b‐1 mutants showed significant decreases in spikelet fertility and grain weight, leading to severe reduction of grain yield, indicating that OsCOI1‐mediated JA signaling affects spikelet fertility and grain filling.