Repetitive Transcranial Magnetic Stimulation Applications Normalized Prefrontal Dysfunctions and Cognitive-Related Metabolic Profiling in Aged Mice

Chronic high-frequency repetitive transcranial magnetic stimulation (rTMS) is a noninvasive brain stimulation technique that has recently received increasing interests as a therapeutic procedure for neurodegenerative diseases. To identify the metabolism mechanism underlying the improving effects of rTMS, we observed that high frequency (25Hz) rTMS for 14 days could reverse the decline of the performance of the passive avoidance task in aged mice. We further investigated the metabolite profiles in the prefrontal cortex (PFC) in those mice and found that rTMS could also reverse the metabolic abnormalities of gamma-aminobutyric acid, N-acetyl aspartic, and cholesterol levels to the degree similar to the young mice. These data suggested that the rTMS could ameliorate the age-related cognitive impairment and improving the metabolic profiles in PFC, and potentially can be used to improve cognitive decline in the elderly.     

不同诱导子对枇杷悬浮细胞生长及熊果酸、齐墩果酸含量的影响

在已建立的稳定枇杷细胞悬浮培养系的试验中,研究加入诱导子水杨酸（SA）、茉莉酸甲酯（MJ）、水解酪蛋白（CH）和酵母提取物（YE）对枇杷悬浮细胞生长及次生代谢产物熊果酸（UA）、齐墩果酸（OA）含量的影响。结果表明,从细胞生长、UA及OA含量三方面综合考虑,以MJ为100.0 mg.L^-1时培养最佳,此时细胞生长、UA及OA含量分别为对照的1.081、2.540及2.590倍。     

化学突变具有底物结合部位的单克隆抗体制备含硒抗体酶

开发了一种制备抗体酶的新方法。用二硝基氯苯（ＤＮＣＢ）专一地与谷胱甘肽（ＧＳＨ）的巯基反应,合成出半抗原ＧＳＨ－Ｓ－ＤＮＰ。用戊二醛将半抗原偶联到牛血清白蛋白（ＢＳＡ）上,制成全抗原。再用标准的单抗制备法获得具有ＧＳＨ结合部位的单抗（４Ａ４ＩｇＧ）。用苯甲基磺酞氟（ＰＭＳＦ）和Ｈ２Ｓｅ相继处理该单抗,则将单拉结合部位上的丝氨酸（Ｓｅｒ）突变成硒代半胱氨酸（ＳｅＣｙｓ,因而在单抗结合部位上引入了谷胱甘肽过氧化物酶（ＧＰＸ）的催化基团。突变后的单抗具有ＧＰＸ活性,其活力已达到天然ＧＰＸ的数量级水平。动力学行为也与天然ＧＰＸ类似。这种新的含硒抗体酶有优于ＧＰＸ的一些特点。     

Plant ERD2-like proteins function as endoplasmic reticulum luminal protein receptors and participate in programmed cell death during innate immunity

Plant secondary metabolites, such as those derived from the phenylpropanoid pathway, have a beneficial effect on human health. Manipulation of metabolic flux in the phenylpropanoid pathway is important for achieving enhanced production of compounds such as anthocyanins, flavonoids and isoflavonoids. Here, we describe the development of a high-throughput molecular evolution approach that can be used for catalytic improvement of at least four key phenylpropanoid pathway enzymes, within the context of the metabolic pathway. This method uses yeast cells that express plant phenylpropanoid pathway enzymes, leading to formation of a colored intermediate that can be used as a readout in high-throughput screening. Here we report the identification of improved tomato peel 4-coumarate:CoA ligase variants using this approach. We found that the wild-type enzyme is strongly allosterically inhibited by naringenin, a downstream product of the pathway. Surprisingly, at least two of the improved variants are completely insensitive to feedback inhibition by naringenin. We suggest that this inhibition is exerted through a unique and previously unrecognized allosteric domain.     

基于液泡膜质子泵的硝态氮再利用研究进展

全面掌握洛川果园的土壤水分环境特征,不仅可为苹果的园址选择、砧穗组合和改进土壤水分管理措施提供理论依据,而且对我国苹果产区果园提质增效具有借鉴价值.采用定点土壤水分连续监测法,对洛川苹果园的总体土壤水分环境以及不同生长年限、不同立地类型和乔、矮化果园的土壤水分分异特征进行分析.结果表明： 苹果树根际区 (0～200 cm)土壤水分普遍亏欠,且0～60 cm土层的水分亏欠小于60～200 cm土层;生长季0～60 cm土层贮水量与降水量的变化一致,土壤相对含水量大多<60%,季节性旱象严重;果园剖面土壤含水量变异系数随土壤深度加深而递减;随果园生长年限的增大,土壤剖面贮水量下降;在栽培密度一致的条件下,矮化果园5 m土层土壤含水量均高于乔化果园,而栽培密度大的矮化果园的土壤贮水量低于栽培密度小的乔化果园;塬地成龄果园的土壤水分含量最高,川地次之,台地相对较低.密度对果园土壤水分含量有很大影响,在栽培密度一致的条件下,采用矮化栽培能减少土壤水分消耗,显著提高果园土壤含水量;挖株降低栽培密度是维持苹果园土壤水分平衡、实现可持续发展的有效途径.     

南方菟丝子对加拿大一枝黄花的寄生控制效应

以安全性较高的本土植物南方菟丝子和重要的外来入侵植物加拿大一枝黄花为材料,于温室中采用盆栽试验在湿润和半湿润条件下用南方菟丝子寄生不同生长阶段(幼苗阶段、过渡阶段和成株阶段)的加拿大一枝黄花植株,考察加拿大一枝黄花植株被寄生后的营养生长、光合生理、逆境生理等指标,探索适宜南方菟丝子寄生加拿大一枝黄花的最佳条件阈值。结果显示:(1)寄生处理与对照之间,加拿大一枝黄花株高、基径、生物量、叶绿素含量、光合速率、可溶性糖、丙二醛、脯氨酸等指标差异均显著;(2)幼苗组、过渡组被寄生加拿大一枝黄花的株高增量、基径增量、生物量、叶绿素含量、净光合速率均显著低于相应对照组,而其可溶性糖、丙二醛、脯氨酸含量均显著高于相应对照组;(3)在半湿润条件下,加拿大一枝黄花的株高、基径增量均小于湿润条件下植株,其净光合速率、叶绿素含量在幼苗组和过渡组均小于湿润条件下植株,而可溶性糖、丙二醛、脯氨酸含量在在幼苗组和过渡组均大于湿润条件下相应指标;(4)幼苗组、过渡组加拿大一枝黄花被寄生后无法正常开花结实,寄生幼苗组加拿大一枝黄花的南方菟丝子亦无法正常开花结实。研究表明,在湿润与半湿润地区,南方菟丝子可以寄生各生长阶段的加拿大一枝黄花,并对株高1.2 m以下的植株产生较强的寄生胁迫;寄生的最佳时间段为每年的4月到8月。     

Sulfur‐Impregnated,Sandwich‐Type,Hybrid Carbon Nanosheets with Hierarchical Porous Structure for High‐Performance Lithium‐Sulfur Batteries

Sandwich‐type hybrid carbon nanosheets (SCNMM) consisting of graphene and micro/mesoporous carbon layer are fabricated via a double template method using graphene oxide as the shape‐directing agent and SiO₂ nanoparticles as the mesoporous guide. The polypyrrole synthesized in situ on the graphene oxide sheets is used as a carbon precursor. The micro/mesoporous strcutures of the SCNMM are created by a carbonization process followed by HF solution etching and KOH treatment. Sulfur is impregnated into the hybrid carbon nanosheets to generate S@SCNMM composites for the cathode materials in Li‐S secondary batteries. The microstructures and electrochemical performance of the as‐prepared samples are investigated in detail. The hybrid carbon nanosheets, which have a thickness of about 10–25 nm, high surface area of 1588 m² g^?1, and broad pore size distribution of 0.8–6.0 nm, are highly interconnected to form a 3D hierarchical structure. The S@SCNMM sample with the sulfur content of 74 wt% exhibits excellent electrochemical performance, including large reversible capacity, good cycling stability and coulombic efficiency, and good rate capability, which is believed to be due to the structure of hybrid carbon materials with hierarchical porous structure, which have large specific surface area and pore volume.     

广东省曲江县发现鳄蜥

报道了首次发现于广东的鳄蜥的形态结构特征,并将它与广西的鳄蜥进行了比较。     

低氧提高肿瘤细胞反义VEGF165基因表达

为了探讨反义VEGF1 65基因对食管癌的抑制作用 ,并初步探讨利用肿瘤低氧微环境改善基因治疗的效果 ,采用PCR技术和DNA重组技术构建了含低氧反应元件的真核表达载体 ,并用此载体构建了含荧光素酶报告基因和反义VEGF1 65基因的重组载体。用脂质体将重组载体导入食管癌细胞 ,体外用化学发光光度计测定低氧对报告基因表达的调节和ELISA法间接测定低氧对反义VEGF基因表达的调节作用。体内利用裸鼠皮下移植实验研究低氧对反义VEGF1 65基因抑瘤作用的影响。体外实验表明 ,用带低氧反应元件的重组真核表达载体转染食管癌细胞 ,在低氧培养下可以使报告基因的表达提高 3 780 % ,并可以显著提高反义VEGF1 65基因的表达 ,体内用带低氧反应元件的载体将反义VEGF1 65基因导入食管癌细胞中 ,其抑瘤效果显著优于不含该元件的载体 ,抑瘤率分别为 71 .7%和 5 6 .1 %。反义VEGF1 65基因能显著抑制食管癌的生长 ;利用肿瘤低氧可以实现治疗基因的自主调节 ,改善基因治疗的效果     

T-DNA插入水稻群体中卷叶突变体R1-A2的遗传分析

在根癌农杆菌介导的T-DNA(携带有除草剂Basta抗性基因bar和Ds因子)转化中花11水稻群体中,获得了一个叶片发生明显内卷的突变体R1-A。经过连续三代的分离鉴定,获得突变体的纯合株(R1-A2),并与中花11号进行杂交,在调查的36个F_1植株中,全部表现为卷叶,并对Basta除草剂都表现为抗性。在852个F_2单株中,卷叶为645株,正常叶207株,卷叶和正常叶的比例为3:1,其中,卷叶株均对Basta表现抗性,正常叶株均对Basta表现敏感,表明卷叶性状和Basta抗性存在着共分离关系。用扩增Ds因子的引物,对F_2中45个卷叶抗性株进行PCR鉴定,都获得预期长度的Ds因子片段,进一步表明在这些卷叶的植株中都有T-DNA的插入;而30个正常叶敏感株都不能检测到Ds的特征片段。在以卷叶突变(R1-A2)为回交亲本的F_1B_1植株中,全部植株表现卷叶;在以中花11号为回交亲本的F_1B_1植株中,卷叶和正常叶植株的分离比为1:1。上述结果表明该卷叶突变是个显性突变,受一个基因所控制,且该基因的突变与T-DNA的插入有关。