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.     

ROS-Ca is associated with mitochondria permeability transition pore involved in surfactin-induced MCF-7 cells apoptosis

The surfactin can inhibit proliferation and induce apoptosis in cancer cells. Moreover, surfactin can induce cell death in human breast cancer MCF-7 cells through mitochondrial pathway. However, the molecular mechanism involved in this pathway remains to be elucidated. Here, the reactive oxygen species (ROS) and Ca²⁺ on mitochondria permeability transition pore (MPTP) activity, and MCF-7 cell apoptosis which induced by surfactin were investigated. It is found that surfactin evoked mitochondrial ROS generation, and the surfactin-induced cell death was prevented by N-acetylcysteine (NAC, an inhibitor of ROS). An increasing cytoplasmic Ca²⁺ concentration was detected in surfactin-induced MCF-7 apoptosis, which was inhibited by 1,2-bis (2-aminophenoxy) ethane-N,N,N′,N′-tetraacetic acid (BAPTA-AM, a chelator of calcium). In addition, the relationship between ROS generation and the increase of cytoplasm Ca²⁺ was determined. The results showed that surfactin initially induced the ROS formation, leading to the MPTP opening accompanied with the collapse of mitochondrial membrane potential (ΔΨ_m). Then the cytoplasmic Ca²⁺ concentration increased in virtue of the changes of mitochondrial permeability, which was prevented by BAPTA-AM. Besides, cytochrome c (cyt c) was released from mitochondria to cytoplasm through the MPTP and activated caspase-9, eventually induced apoptosis. In summary, surfactin has notable anti-tumor effect on MCF-7 cells, however, there was no obvious cytotoxicity on normal cells.     

应用随机PCR方法鉴定一株真养产碱杆菌

采用随机引物PCR技术从新建细胞培养室空气中获得一段长414bp的片段,通过克隆测序及序列分析,结果表明所测序列与真养产碱杆菌主要参考菌株的同源性分别高达79%-83%,由其推导的氨基酸序列与真养产碱杆菌主要参考菌株的同源性高达86.4%-89.1%,从而确定所分离菌株为真养产碱杆菌。     

力竭性运动后大鼠血清CK、CK-MB活性和心肌组织形态学的动态改变

目的：探讨一次和反复力竭性运动后不同时相大鼠血清肌酸激酶（CK）、肌酸激酶同工酶（CK-MB）与心肌损伤的变化规律。方法：通过力竭性游泳制备运动性心肌损伤模型,分别于运动后即刻和3 h6、h、12 h2、4 h4、8 h、96 h检测血清CK、CK-MB活性,并观察心肌组织形态学的动态变化。结果：大鼠一次力竭运动后0~12 h,CK和CK-MB活性明显增加,6 h达高峰;心肌炎细胞浸润灶逐渐增多,胞质嗜酸性增强,损伤高峰在12 h左右。反复力竭运动后0~12 h和48 h9、6 h CK和CK-MB活性皆明显增加,分别于运动后即刻和96 h达高峰;心肌细胞均有不同程度的损伤,48 h最严重。结论：过度运动和/或力竭性运动皆引起运动性心肌损伤,同时存在延迟性心肌损伤。     

番茄LeHsp110/ClpB基因的分子克隆及其对植物耐热性的影响

HSP100ClpB是Clp蛋白家族的一员,具有分子伴侣功能,与细胞“获得耐热性(acquiredthermotolerance)”相关。从番茄cDNA文库中筛选到长度达3144bp的cDNA,依据最长的开放读码框推导出的多肽含980个氨基酸残基,分子进化分析结果表明该蛋白属于HSP100ClpB家族,因其计算分子量为110kD,所以命名为LeHSP110ClpB。实验证明,LeHsp110ClpB在番茄叶片中没有组成型表达,为热诱导型基因,其编码蛋白定位于叶绿体基质。利用农杆菌介导法,将CaMV35S驱动的反义LeHsp110ClpBcDNA片段导入番茄,高温下转反义基因的番茄株系中LeHsp110ClpBmRNA水平明显低于对照,转基因株系的PSⅡ对高温胁迫更加敏感,说明HSP110ClpB在植物耐热性方面起重要作用。     

Purification and properties of alkaline phosphatase of silkworm Bombyx mori

Alkaline phosphatase(AKP),from the succus entericus of silkworm,was purified using 10%-50% ammonium sulfate fractions,ion exchange chromatography Of DEAE-Sepharose,and size exclusion chromatography of Sephacryl S-200.The purification fold was 464 times and specified activity was 3936 U/mg.Optimum pH value of the phosphatase was 10.5,and was stable between pH 7.5 and 11.The optimum temperature of the phosphatase was 40℃ and it was unstable over 50℃.Km value of the phosphatase was 1.25 mmol/L.In a given condition,the phosphatase was selectively modified by PCMB,NBS,PMSE TNBS,SUAN,DTT,BrAc,and IAc,the results indicate that PMSF,SUA,BrAc,IAc,and TNBS could Obviously inhibit the activity of the phosphatase,and the degree of inhibition depended on the concentration of these reagents.There was little effect on the activity of phosphatase after treatment by PMSF,DTT,and NBT.We primarily conclude that mercapto and imidazole are essential for AKP from silkworm.Also,Lys residue and disulfide bands are necessary to protect the catalysis of the AKP.     

米槠与杉木细根凋落物是否在自身群落中分解得更快?

本研究应用网袋法对福建省万木林自然保护区米槠（Castanopsis carlesii）、杉木（Cunninghamia lanceolata）细根在米槠林群落和杉木林群落交叉分解进行了为期2年的研究。结果表明,0-1mm、1-2mm米槠细根在米槠群落比在杉木群落分解速率快,而相同径级杉木细根在两群落分解差异较大。0—1mm杉木细根在杉木群落的分解速率高于米槠群落,而1—2mm杉木细根在杉木群落的分解速率只及米槠群落的48％。米槠、杉木细根在两群落分解的差异表明,群落立地条件对细根分解存在较大的影响。     

蚕豆叶绿体atpE基因的克隆,测序和表达

蚕豆叶绿体的ａｔｐＥ和ａｔｐＢ基因在叶绿体ＤＮＡ ＫｐｎＩ酶切的第九条（约４．０ｋｂ）片段上,此片段被克隆到载体ｐＵＣ１８中,构成重组质粒ｐＵＫ１。用玉米叶绿体ａｔｐＥ基因作探针对ｐＵＫ１的ＣｌａＩ、ＥｃｏＲＩ等的酶切产物进行杂交,确定了蚕豆叶绿体的ａｔｐＥ在ＣｌａＩ酶切的约０．９ｋｂ的片段上。根据ｐＢｕｌｅｓｃｒｉｐｔ ＫＳ（＋）ＤＮＡ多聚接头Ｆ引物和Ｒ引物测序,得到ε亚基基因的完整核苷酸序列。     

固氮树种在混交林中的作用研究Ⅲ.固氮树种凋落物分解及N的释放

研究了１１种固氮和非固氮树种凋落物分解及可利用态Ｎ的释放．结果表明,固氮树木凋落物中Ｎ的生物分解系数、落叶分解过程中干重的损失率及有效态氮的释放分别比非固氮树种高出１．３、１．５和８．２倍．