Electronic structure engineering of transition metal dichalcogenides for boosting hydrogen energy conversion electrocatalysts

Electrocatalytic water splitting for hydrogen production is an appealing strategy to reduce carbon emissions and generate renewable fuels.This promising process,however,is limited by its sluggish reaction kinetics and high-cost catalysts.The two-dimensional(2D)transition metal dichalcogenides(TMDCs)have presented great potential as electrocatalytic materials due to their tunable bandgaps,abundant defective active sites,and good chemical stability.Consequently,phase engineering,defect engineering and interface engineering have been adopted to manipulate the electronic structure of TMDCs for boosting their exceptional catalytic performance.Particularly,it is essential to clarify the local structure of catalytically active sites of TMDCs and their structural evolution in catalytic reactions using atomic resolution electron microscopy and the booming in situ technologies,which is beneficial for exploring the underlying reaction mechanism.In this review,the growth regulation,characterization,particularly atomic configurations of active sites in TMDCs are summarized.The significant role of electron microscopy in the understanding of the growth mechanism,the controlled synthesis and functional optimization of 2D TMDCs are discussed.This review will shed light on the design and synthesis of novel electrocatalysts with high performance,as well as prompt the application of advanced electron microscopy in the research of materials science.

Prepartion and identification of activity of anti-HPV-6b/11E1 universal ribozyme——Rz1198 in vitro

Aim: To study the preparation and cleavage activity of Rz1196 directed against HPV-6bE1 and HPV-11E1 (HPV-6b/11E1) transcripts in vitro. Methods: HPV-6b/11E1 gene fragments were cloned into T-vector under the control ofT7 promoter, ～(32)P-labeted HPV-6b/11E1 transcripts as target-RNAs were transcribed in vitro and purified by PAGE.Rz1198 gene designed as a universal ribozyme for both HPV-6b/11E1 transcripts was cloned into vector p1.5 between5'-cis-Rz and 3'-cis-Rz. a2P-labeled Rzl198 transcript was gel-purified, incubated with target-RNAs at different condi-tions and autoradiographed after denaturing gel-electrophoresis. Results: Rz1198 was active at 37℃. The optimaltemperature was 50℃. For HPV-6bE1, k_m = 12.2 nmol/L, k_cat = 0.18 min～(-1); For HPV-11E1, k_m= 14.7 nmol/L,k_cat =0.14 min～(-1). All these revealed that the design of Rz1198 was correct. It could be a universal ribozyme for thetwo substrates--HPV-6bE1 and HPV-11E1 transcripts. Conclusion: Rz1198 prepared in vitro possesses the perfectspecific catalytic cleavage activity. It leads to the expectation that, in the future, it will be possible to develop a newnucleic acid drug from Rz1198 which can efficiently inhibit the replication of HPV-6b/11 DNA in vivo. (Asian J An-drol 1999 Dec; 1: 195-201)

PREPARATION,IDENTIFICATION AND INTERFACIAL ACTIVITIES OF PETROLEUM CARBOXYLATE AS SURFACTANT FOR CHEMICAL FLOODING

Petroleum carboxylate that may be suitable for tertiary oil recovery have been produced inexpensively from the fractions of Daqing crude oil by a two step process.The feed stock was first oxidized in the vapor phase,followed by reaction of the oxidized products with sodium hydroxide.Dilute solutions of sodium carboxylates were produced and show ultralow(10^(-2)mN/m)interfacial tensions(IFTs)against a variety of hydrocarbons with a wide range of ACN(Alkane Carbon Number).Infrared spectroscopy was used to identify the functional groups in the oxidized and the saponified products.

TRANSFORMING ACTIVITY OF DNA FROM HUMAN ESOPHAGEAL CANCER AND THE IDENTIFICATION OF THE TRANSFORMING GENE

Rat-1 cells were transfected with DNA from human esophageal cancer 2K, 4K, 6K, 7K. 8K. The transforming foci were obtained and the transforming cell lines were established. The cell lines can form larger colony in soft agar. Those nude mice injected subcutaneously with the cells suffered from larger fibrous sarcoma. This indicates that the cell lines have carcinogenicity. The experimental results suggest that human DNA sequence and human Ha-ras special 616Kb (BamHI) band are present in the DNA of the transforming cells. The over-expression of ras gene products P21 were found in the tissues of exophageal cancer, the tissues adjacent to tumor and the transforming cells.

Perspectives in application of biosensors for the modernization of traditional Chinese medicine

Biosensor is an instrument which is sensitive to biological material and converts its concentration into electrical signals.Organisms such as enzymes, antibodies, tissues, cells and so on can selectively identify specific substances. Thesemolecular recognition functions can be combined with the target, such as the binding of antibodies and antigens, and thebinding of enzymes to the substrate through the recognition process. Biosensor has the advantages of high specificity,high sensitivity, fast reaction speed, low cost and easy operation. It has wide application prospect in food, pharmacy,chemical industry, clinical examination, biomedicine, environmental monitoring and so on, especially as a newtechnology means, in the field of modern herbal medicine research influence. Studies have demonstrated that thebiosensing technology has been applied to, traditional Chinese medicine （TCM） targets, isolation and purification ofTCM, the mechanism of TCM, quality control of TCM, the active ingredients detection of TCM and other basicresearches. Biosensor technology has made an important contribution to the research of modern herbal medicine, and hasbecome a Hot-spot in future research.

Process Management in Insurance Companies

The importance of insurance activity is constantly growing, generating new problems and setting new challenges. One of these challenges is to meet the growing requirements and expectations of customers. This requires the efficient management of insurance companies. This means the necessity of applying modern management concepts, first and foremost, the concept of process management and instruments related to this process. This article describes the results of research on process management in insurance companies operating in Poland that was conducted by the Faculty of Management at the Warsaw University of Technology and presents the concept of the identification of processes carried out in insurance companies encompassing management, basic and auxiliary processes, as well as the objectives of the processes and the relationships between the basic processes and other processes carried out in insurance companies.

Activity identification of anti-caspase-3 mRNA hammerhead ribozyme in both cell-free condition and BRL-3A cells

Objective To study the transcription effects and cleavage activities of rat caspase-3 specific hammerhead ribozyme (Rz107) in both cell-free conditions and BRL-3A cells. Methods Rat caspase-3 gene fragment was cloned into the pGEM-T EASY vector under the T7 promoter control. The 32 P-labeled caspase-3 transcript was the target-RNA. Rz107 genes designed against caspase-3 mRNA were cloned into vector p1.5 between 5'-cis-Rz and 3'-cis-Rz. 32 P-labeled ribozyme transcripts were incubated with target-RNAs at different conditions and autoradiographed after denaturing gel-electrophoresis. Rz107 was electroporated into BRL-3A cells and the Rz107 expression was analyzed by RT-PCR. Results In cell-free conditions, Rz107 was active at 37℃. The optimal temperature was 50℃. The Km and kcat were 14.13?nmol/L and 2.31*min-1 respectively. Intracellular cleavage efficiency of Rz107 was 37%, as analyzed by RT-PCR. This indicated that the design of Rz107 was correct, and Rz107 had the activity of common enzymes.Conclusions Rz107 in cell-free conditions possessed perfect specific catalytic cleavage activity, and it can also cleave the target RNA successfully in cells. The results illustrate the feasibility of ribozyme therapy as a potential alternative approach for treating liver disease caused by apoptosis.

Antitumor Compound Identification from Zanthoxylum bungeanum Essential Oil Based on Composition-activity Relationship

The chemical composition of Zanthoxylum bungeanum（Z bungeanum） essential oi1（39 batches） was analyzed by gas chromatography-mass spectrometry（GC-MS） analysis（23 ingredients）, and the antitumor activity against HeLa cells was detected via the MTT[3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide] assay. Two composition-activity relationship（CAR） models, generalized regression neural network（GRNN） and support vector regression（SVR） were respectively used to calculate the mean impact value（MIV） so as to identify bioactive com- pounds. Among them 9 ingredients（peaks 4, 15, 7, 8, 13, 3, 16, 9 and 11） were selected due to their high absolute MIVs. All of them have been confirmed with potential antitumor activity by previous researches. The CAR model combined with MIV was expected to be a credible tool for the active compound identification from herbs.