Indirect Flow Injection Chemiluminescence Method for the Determination of Tetracycfines Using Cu（]I） as a Probe Ion

This paper reported an indirect flow injection chemiluminescence （FI-CL） method for the determination of the drugs tetracycline （TC）, chlortetracycline （CTC） and oxytetracycline（OTC） using Cu（ Ⅱ ） as a probe ion. The CL reaction was induced on-line and after injection of the sample the negative peaks appeared as a result of complexation. The method was applied to the determination of TCs in pharmaceuticals and human urine with recoveries in the range95-105%.     

Crystal Structure and Spectra Characters of 2-Benzoly-3-(4-(1,2,4-triazole)-5-anilino-thiophene and 2-(4-Methyl-benzoly)-3-(4- chlrolphenyl)-3-(1,2,4-triazole)-5-anilino-thiophene

Triazole derivatives are widely studied, because they represent the largest group of modern fungicides and are widely used both in human and veterinary therapy and in agriculture. We synthesized the title compound in which the thiophene ring was substituted by a 1,2,4-triazole group, a phenacyl group, a phenylaminol group and a benzene ring.     

When and where rivers meet the sea

River mouth areas provide one of the most desired locations for human habitation. Although occupying only a small portion of the total length of the world's shoreline, river mouths are dynamic and complex with highly variable physical and chemical characteristics.The size, shape, and position of a river's mouth are dependent on its geologic and hydrologic history. Further, the processes that operate in a river's mouth are affected by the sea and its currents, tides, and salinity; the river and its discharge and sediment characteristics; and wind generated waves and storm surges. Present-day locations are, geologically speaking, of recent origin because of the rise in sea level that accompanied deglaciation and the sedimentation that followed drowning.     

Etoposide Induces Mitochondria-Associated Apoptotic Cell Death in Human Gastric Carcinoma Cells

Recent observations indicate that the resistance of apoptosis is an important process of tumor metastasis and metastases are the cause of 90% of human cancer death. Etoposide, a semisynthetic derivative of the podophyllotoxins, is a clinically used anti-cancer reagent, but the effects of it on metastatic gastric carcinoma cells are totally unknown. In this study, etoposide induced apoptotic cell death in human gastric adenocarcinoma cell line SGC-7901, derived from metastatic lymph nodes, as evidenced by the analysis of DNA fragmentation, apoptotic body formation, caspase activation, and apoptosis specific changes in cell morphology is demonstrated. The depolarization of mitochondrial membrane and the release of cytochrome c were most early events in etoposide treated SGC-7901 cells, and were followed by caspase-3 activation and PARP cleavage. Caspase-8 activation was not detected under the same condition. Thus, it was proposed that etoposide induces caspase-associated apoptotic cell death in human metastatic gastric carcinoma, which is initiated by mitochondrial cytochrome c release.     

Novel Analogues of a-Terthienyl, Thienyl 1, 3, 4-Thia(oxa)diazoles as Potential Photoactivated Insecticides: Synthesis and Bioactivity

a-Terthienyl (aT) is a phototoxic compound originated from the marigold Tagetes eretra1. The aT and its analogues have been widely used for photodynamic killing of insects, in photodynamic therapy for dermatophytes, and in human immunodeficiency virus (HIV)2. The phototoxicity of aT and its derivatives are attributed to their triplet states that easily generate a reactive oxygen species (ROS). Many of the biomolecules and enzymes are targets of these ROS, such as DNA in vitro and in v…     

Preface to Special Issue on Catalysis in Organic Synthesis

<正>Organic synthesis plays a central role in chemistry. The cre-ation of compounds with new properties and functions both distinguishes synthetic chemistry from other sciences and also emphasizes chemistry’s central place in science. In principle, the possibilities for atomic and molecular manipulation are unlimited, which provides a firm molecular basis for biosci-ence, materials science and medical science. Man-made chemi-cals have entered many research fields where they play im-portant roles. Synthesis is changing all aspects of human socie-ty and improving the quality of our life. Catalysts are the     

Progress of estuarme research in China over last 50 years

It is well known that the estuarine research in China has got great achievements since the past 50 years. The development of estuarine research in China and progress in fundamental study are presented firstly in this paper. Especially in the aspect of theoretic studies, a distinctive feature is the combination studies of dynamics, sedimentology and geomorphology, which obtain a series of achievements, such as estuarine diluted water, estuarine fronts, turbidity maximum, sediment movement, formation of mouth bar, estuarine discontinuity phenomena, estuarine development, etc. Then some successful applications are introduced taking the Qiantang River Estuary and Yangtze Estuary as examples. Finally, main directions of estuarine research are discussed on fundamental study, the impacts of human activities on estuaries, estuarine material flux, sediment movement, prediction of estuarine erosion and accretion, estuarine discontinuity, artificial estuaries, land reclamation and wetland protection.     

Determination of trace amounts of morphine in human plasma by anodic adsorptive stripping differential pulse voltammetry

New adsorptive anodic differential pulse stripping voltammetry method for the direct determination of morphine at trace levels in human plasma of addicts is proposed.The procedure involves an adsorptive accumulation of morphine on a HMDE,followed by oxidation of adsorbed morphine by voltammetry scan using differential pulse modulation.The optimum conditions for the analysis of morphine are pH 10.5,Eacc of -100 mV（vs.Ag/AgCl）,and tacc of 120 s.The peak current is proportional to the concentration of morphine,and a Linear calibration graph is obtained at 0.01-3.10μg mL^-1.A relative standard deviation of 1.06%（n=5）was obtained,and the limit of detection was 3 ng mL^-1.The capabiLity of the method for the analysis of real samples was evaluated by the determination of morphine in spiked human plasma and addicts human plasma with satisfactory results.     

Intestinal Transport and Biotransformation of Resibufogenin and Cinobufagin in Chan Su via HPLC/APCI-MS~n

In vitro models of human colon carcinoma cell line(Caco-2 cell monolayer) and human intestinal bacteria were used to investigate the intestinal transport and biotransformation of resibufogenin and cinobufagin in Chan Su by HPLC/APCI-MSn. The experimental results of Caco-2 cell monolayer demonstrate that the apparent permeability coefficients(Papp) of resibufogenin and cinobufagin are higher than 10-6 cm/s, which indicates that both resibufogenin and cinobufagin have a good absorption in the small intestine....     

LIQUID AND SOLID TWO-PHASE RADIOIMMUNOASSAY——SIMULTANEOUS MEASUREMENT OF LEVELS OF TRIIODOTHYRONINE AND THYROXINE OF HUMAN SERUM IN A SINGLE SPECIMEN

The principle of the liquid and solid two-phase radioimmunoassay and its application to measuringthe concentrations of triiodothyronine and thyroxine of human serum in a single sample at the sametime are described in this paper. Rabbit anti-triiodothyronine antiserum was immobilized on the innersurface of a plastic tube as solid-phase radioimmunoassay system of testing triiodothyronine and donkeyanti-rabbit gamma globulin antiserum was used to separate immunocomplex in liquid-phase radioim-munoassay system of thyroxine reaction. In both systems, radioiodine-125-labelled antigens were usedas tracer. Through simple calculation, we can ger the results of serum concentrations of triiodothyro-nine and thyroxine in a single sample. Compared with classical single-component radioimmunoassay oftriiodothyronine and thyroxine and by methodological appraisal of two-phase radioimmunoassay itself,this method has the advantages of very high efficiency, reliability and also has the same specificityand precision.     

Education for sustainable development

Education is a very important factor in human development,Human development does not start with the possession of goods,as this is one measure of development.It begins with people and their education.There are ,of course,other human development resouces that are of importance,However,without education all other resources remain as latent potentials to support human development.     

Dynamics of excited m-dichlorobenzene

Dichlorobenzene is a precursor molecule of di-oxins, which are some of the most toxic chemicals and are suspected of being mutagenic with the structure of benzene rings containing different numbers of chlorine atoms. They are seriously harmful to the health of human. Therefore, it is necessary to study these aryl chemicals especially dichlorobenzene molecules in great detail. In recent years, a number of groups have investi-gated the molecules of aryl halide. The near ultraviolet absorption sp…     

Antibodies as Tailor-Made Chiral Selectors: an Interdisciplinary Approach to Enantiomer Separation and Detection

 It has long been known that the configurational isomers of biologically active compounds, e.g., nutrients, pesticides, and drugs, may exhibit different activities in a chiral environment such as the human body. Although the majority of drugs presently in development are chiral, analytical and preparative methods for the quantitative determination and purification of stereoisomers still lag behind. One reason is that commonly used chiral selectors for the direct resolution of enantiomers are not tailor-made for a specific analyte. The identification of suitable selectors for a particular pair of enantiomers still requires considerable experimentation and is generally demanding with regard to material, time and labor. The rational design of chiral host molecules, therefore, represents a challenge in facilitating enantiomer analysis. In this article, we describe how a combination of techniques ranging from organic synthesis to molecular biology yields antibodies of predetermined specificity and stereoselectivity that can be used as tailor-made chiral selectors for the chromatographic separation of enantiomers and their sensitive detection in immunosensors.     

MALIGNANT TRANSFORMATION OF HUMAN FETAL LUNG FIBROBLASTS INDUCED BY NITROSAMINE COMPOUNDS IN VITRO

This report, for the first time, demonstrates that diethyl-nitrosamine (NDEA) and a new nitrosamine compound-N-l-methylacetonyl-N-3-methylbutyl-nitrosamine (MAMBNA), which are suspicious carcinogens of esophageal cancer (EC) in Linxian, Henan Province, are able to cause the malignant transformation (altered morphology, extended life span, anchorage independent growth, invasiveness, tumorigenicity, etc.) of normal diploid fibroblasts derived from human fetal lung. Besides, the preselection for clonogenic cells, which seem to be more readily to be transformed, in soft agar before carcinogen treatment, could be considered as one of the useful ways in establishment of a model system of malignant transformation of human fibroblasts in vitro.     

DNA Nanotechnology-based Biocomputing

With silicon-based microelectronic technology pushed to its limit,scientists hunt to exploit biomolecules to power the bio-computer as substitutes.As a typical biomolecule,DNA now has been employed as a tool to create computing systems because of its superior parallel computing ability and outstanding data storage capability.However,the key challenges in this area lie in the human intervention during the computation process and the lack of platforms for central processor.DNA nanotechnology has created hundreds of complex and hierarchical DNA nanostructures with highly controllable motions by exploiting the unparalleled self-recognition properties of DNA molecule.These DNA nanostructures can provide platforms for central processor and reduce the human intervention during the computation process,which can offer unprecedented opportunities for biocomputing.In this review,recent advances in DNA nanotechnology are briefly summarized and the newly emerging concept of biocomputing with DNA nanostructures is introduced.     

An eco-friendly water mediated synthesis of 1,2,3-triazolyl-2- aminopyrimidine hybrids as highly potent anti-bacterial agents

An elegant and efficient synthesis of novel 1,2,3-triazole fused 2-aminopyrimidine hybrids has been accomplished for the first time in the green solvent viz. water. The hybrid molecules exhibit significant anti-bacterial activity when screened against three human pathogens viz. Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella pneumoniae. In comparison to the commercially marketed drug tetracycline, some of them are equally potent and a few are more potent.     

Isolation, Mapping, DNA Sequence and RFLPs Studies of Random Single-Copy DNA Segments on Human X Chromosome

Using the total human/mouse DNA as the probe, screening has been carried out three times with in situ plaque hybridization to obtain the single-copy DNA sequence from the human X chromosome genomic library. The effective rate of screening is 1. 45%. DNAs from clones containing single-copy inserts have been analyzed by a panel of hybrid cells with or without human X chromosome. Three segments, designated by DXFD52,73,75, are mapped to the X chromosome. DXFD52 has been precisely localized on Xq12-q13 with in situ chromosomal hybridization. DXFD52 has been partially sequenced. The results indicate that DXFD52 is a new isolated single-copy segment on the X chromosome. Great progress in the RFLPs study with DXFD52 has been achieved in the population of Chongqing, Sichuan Province. The results show that the DXFD52 can be used to detect the RFLP with Hind Ⅲ, Bgl Ⅱ, and Hinf Ⅰ. DXFD52 will be a potential "landmark" for the construction of the complete linkage map of human genome and the analysis of genomic s     

EXPRESSION OF A PARTIAL SYNTHETIC HUMAN TNF cDNA IN E. coli

A recombinant human tumour necrosis factor (rhTNF) cDNA was constructed. The TNF gene was isolated from a human genomic gene library. There are four exons in the TNF gene. The fourth exou codes for 140 amino acids of the TNF matured protein which is composed of 157 amino acids. A major portion of the fourth exon was isolated and then ligated to a synthesized DNA fragment coding for the remaining amino acids. The partial synthetic hTNF (rhTNF) cDNA thus generated was subcloned into a vector and successfully expressed in E. coli. 5-1 fer1entator was used to produce rhTNF. About 20g (wet weight) of bacterial pellet per liter medium and 106—10~7 units of cytotoxicity to L929 cells per milliliter medium were obtained. rhTNF was purified by HPLC and dried with a freeze dryer, rhTNF with a purity of about 95% in the form of white powder was obtained. The sequence of ten amino acids at the amino terminus of the rhTNF was determined. The result showed that it was identical with that of the natural human TNF.     

QSAR Study and VolSurf Characterization of Human Intestinal Absorption of Druge

The prediction of human intestinal absorption is a major goal in the design,optimization,and selection of candidates for the develoment of oral drugs.In this study,a computerized method(VolSurf with GRID) was used as a novel tool for predicting human intestinal absorption of test compound,and for determining the critical molecular properties needed for human intestinal absorption.The tested molecules consisted of 20 diverse drug-like compounds.Partial least squares(PLS) discriminant analysis was used to correlate the experimental data with the theoretical molecular properties of human intestinal absorption.A good correlation(r^2=0.95,q^2=0.86) between the molecular modeling results and the experimental data demonstrated that human intestinal absorption could be predicted from the three-dimensional(3D) molecular structure of a compound .Favorable structureal properties identified for the potent intestinal absorption of drugs included strong imbalance between the center of mass of a molecule and the barycentre of its hydrophilic and hydrophobic regions and a definitive hydrophobic region as well as less hydrogen bonding donors and acceptors in the molecule.     

Construction of high stability indium gallium zinc oxide transistor biosensors for reliable detection of bladder cancer-associated microRNA

Bladder cancer is the most common malignant tumours with high morbidity, mortality and recurrence.However, currently developed detection methods for bladder cancer-associated urine biomarkers are hindered by their extremely low abundance. Hence, the exploration of a highly sensitive and selective approach for the detection of trace bladder cancer-associated biomarkers in human urine is of vital importance for the diagnosis of bladder cancer. Herein, we developed a highly reliable indium gallium ...