1.Remarkable rate acceleration of SmI3-mediated iodination of acetates of Baylis-Hillman adducts in ionic liquid: facile synthesis of (Z)-allyl iodides.
Yun-kui LIU ; Hui ZHENG ; Dan-qian XU ; Zhen-yuan XU ; Yong-min ZHANG
Journal of Zhejiang University. Science. B 2006;7(3):193-197
Stereoselective transformation of Baylis-Hillman acetates 1 into corresponding (Z)-allyl iodides 2 has been achieved by treatment of 1 with samarium triiodide in THF. Remarkable rate acceleration of samarium triiodide-mediated iodination of 1 was found when ionic liquid 1-n-butyl-3-methyl-imidazolium tetrafluroborate ([bmim]BF(4)) was used as reaction media in stead of THF. This novel approach proceeds readily at 50 degrees C within a few minutes to afford (Z)-allyl iodides 2 in excellent yields. A mechanism involving stereoselective iodination of the acetates of Baylis-Hillman adducts by samarium triiodide is described, in which a six-membered ring transition state played a key role in the stereoselective formation of 2.
Acetates
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chemistry
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Iodides
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chemical synthesis
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Ions
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Kinetics
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Samarium
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chemistry
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Solutions
2.Characterization of a bioflocculant from a newly isolated Vagococcus sp. W31.
Jie GAO ; Hua-ying BAO ; Ming-xiu XIN ; Yuan-xia LIU ; Qian LI ; Yan-fen ZHANG
Journal of Zhejiang University. Science. B 2006;7(3):186-192
Screening of microorganisms producing flocculating substances was carried out. A strain secreting a large amount of bioflocculant was isolated from wastewater samples collected from the Little Moon River in Beijing. Based on the morphological properties and 16S rDNA sequence analysis, the isolate (designated W31) was classified as Vagococcus sp. A bioflocculant (named MBFW31) produced by W31 was extracted from the culture broth by ethanol precipitation and purified by gel chromatography. MBFW31 was heat-stable and had strong flocculating activity in a wide range of pH with relatively low dosage requirement. MBFW31 was identified as a polysaccharide with molecular weight over 2 x 10(6). It contained neutral sugar and uronic acid as its major and minor components, respectively. Infrared spectra showed the presence of hydroxyl, carboxyl and methoxyl group in its molecules. The present results suggested that MBFW31 had potential application in wastewater treatment.
Carbohydrates
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analysis
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chemistry
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Enterococcus
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genetics
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isolation & purification
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metabolism
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Flocculation
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Species Specificity
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Waste Disposal, Fluid
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methods
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Water Microbiology
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Water Pollutants
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isolation & purification
3.Influence of temperature fluctuation on thermophilic anaerobic digestion of municipal organic solid waste.
Man-chang WU ; Ke-wei SUN ; Yong ZHANG
Journal of Zhejiang University. Science. B 2006;7(3):180-185
A laboratory-scale experiment was carried out to assess the influence of temperature fluctuation on thermophilic anaerobic digestion of municipal organic solid waste (MOSW). Heating failure was simulated by decreasing temperature suddenly from 55 degrees C to 20 degrees C suddenly; 2 h time is needed for temperature decrease and recovery. Under the conditions of 8.0 g/(L.d) and 15 d respectively for MOSW load and retention time, following results were noted: (1) biogas production almost stopped and VFA (volatile fatty acid) accumulated rapidly, accompanied by pH decrease; (2) with low temperature (20 degrees C) duration of 1, 5, 12 and 24 h, it took 3, 11, 56 and 72 h for the thermophilic anaerobic digestion system to reproduce methane after temperature fluctuation; (3) the longer the low temperature interval lasted, the more the methanogenic bacteria would decay; hydrolysis, acidification and methanogenesis were all influenced by temperature fluctuation; (4) the thermophilic microorganisms were highly resilient to temperature fluctuation.
Archaea
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cytology
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physiology
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Bacteria, Anaerobic
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cytology
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physiology
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Biodegradation, Environmental
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Cell Survival
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Cities
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Fatty Acids, Volatile
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metabolism
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Hydrogen-Ion Concentration
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Methane
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metabolism
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Refuse Disposal
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methods
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Sewage
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microbiology
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Temperature
4.Study of removal effect on Mesocyclops leukarti with oxidants.
Jin-long ZUO ; Fu-yi CUI ; Tao LIN
Journal of Zhejiang University. Science. B 2006;7(3):171-179
Cyclops of zooplankton propagates prolifically in eutrophic waterbody and it cannot be exterminated by conventional disinfection process. The mutagenicity of Mesocyclops leukarti and its extermination with oxidants in a drinking waterworks in China were studied. Among five oxidants for use in bench-scale, chlorine dioxide is the most effective and the potassium permanganate is the weakest against Mesocyclops leukarti under the same conditions. Full-scale results showed that Mesocyclops leukarti could be effectively removed from water by 1.0 mg/L chlorine dioxide preoxidation combined with conventional removal physical process. After filtration, chlorite, a by-product of prechlorine dioxide, is stable at 0.45 mg/L, which is lower than the critical value of the USEPA. GC-MS examination and Ames test further showed that the quantity of organic substance and the mutagenicity in water treated by chlorine dioxide preoxidation are obviously less than those of prechlorination.
Copepoda
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drug effects
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physiology
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Dose-Response Relationship, Drug
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Filtration
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methods
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Oxidants
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toxicity
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Survival Rate
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Water Pollutants
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isolation & purification
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Water Pollution
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prevention & control
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Water Purification
;
methods
5.Pharmacogenetics, pharmacogenomics and ecogenetics.
Journal of Zhejiang University. Science. B 2006;7(2):169-170
Pharmacogenetics and pharmacogenomics deal with the role of genetic factors in drug effectiveness and adverse drug reactions. The promise of a personalized medicine is beginning to be explored but requires much more clinical and translational research. Specific DNA abnormalities in some cancers already have led to effective targeted treatments. Racially determined frequency differences in pharmacogenetic traits may affect choice of treatment requiring specific testing rather than basing treatments according to racial designation. The role of genes in variable responses to foreign chemicals (xenobiotics) has been termed ecogenetics or toxicogenetics raising problems in public health and occupational medicine. Nutrigenetics refers to genetic variation in response to nutrients and may affect nutritional requirements and predisposition to chronic disease.
DNA
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analysis
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Drug-Related Side Effects and Adverse Reactions
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Ecology
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Genetic Variation
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Genome, Human
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Genotype
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Humans
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Nutritional Physiological Phenomena
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Pharmaceutical Preparations
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Pharmacogenetics
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methods
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Phenotype
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Xenobiotics
6.Genetics of complex diseases.
Journal of Zhejiang University. Science. B 2006;7(2):167-168
Approaches to the study of the genetic basis of common complex diseases and their clinical applications are considered. Monogenic Mendelian inheritance in such conditions is infrequent but its elucidation may help to detect pathogenic mechanisms in the more common variety of complex diseases. Involvement by multiple genes in complex diseases usually occurs but the isolation and identification of specific genes so far has been exceptional. The role of common polymorphisms as indicators of disease risk in various studies is discussed.
Genetic Diseases, Inborn
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genetics
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Genetic Predisposition to Disease
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Genetic Techniques
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Humans
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Inheritance Patterns
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Linkage Disequilibrium
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Models, Genetic
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Polymorphism, Genetic
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Risk Factors
7.Human biochemical genetics: an insight into inborn errors of metabolism.
Journal of Zhejiang University. Science. B 2006;7(2):165-166
Inborn errors of metabolism (IEM) include a broad spectrum of defects of various gene products that affect intermediary metabolism in the body. Studying the molecular and biochemical mechanisms of those inherited disorder, systematically summarizing the disease phenotype and natural history, providing diagnostic rationale and methodology and treatment strategy comprise the context of human biochemical genetics. This session focused on: (1) manifestations of representative metabolic disorders; (2) the emergent technology and application of newborn screening of metabolic disorders using tandem mass spectrometry; (3) principles of managing IEM; (4) the concept of carrier testing aiming prevention. Early detection of patients with IEM allows early intervention and more options for treatment.
Humans
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Infant, Newborn
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Metabolism, Inborn Errors
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diagnosis
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genetics
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Neonatal Screening
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Phenotype
8.Human cancer genetics.
Journal of Zhejiang University. Science. B 2006;7(2):164-164
The short report will be focused on the genetic basis and possible mechanisms of tumorigenesis, common types of cancer, the importance of genetic diagnosis of cancer, and the methodology of cancer genetic diagnosis. They will also review presymptomatic testing of hereditary cancers, and the application of expression profiling to identify patients likely to benefit from particular therapeutic approaches.
Genes, Tumor Suppressor
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Genetic Techniques
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Genetics, Medical
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Humans
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Neoplasms
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diagnosis
;
genetics
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Nucleic Acid Hybridization
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Sequence Analysis, DNA
9.Clinical cytogenetics and molecular cytogenetics.
Journal of Zhejiang University. Science. B 2006;7(2):162-163
The short report will be focused on helping our students to understand commonly used conventional and cutting edge cytogenetic techniques and their clinical applications, the advances and drawbacks of each technique, and how to pick the right test(s) for a specific patient in order to achieve a proper diagnosis efficiently and economically.
Chromosomes
;
ultrastructure
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Cytogenetic Analysis
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Cytogenetics
;
methods
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Genetic Techniques
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Humans
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In Situ Hybridization, Fluorescence
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Molecular Diagnostic Techniques
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Nucleic Acid Hybridization
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Oligonucleotide Array Sequence Analysis
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Translocation, Genetic
10.Genomics and world health: hopes and realities.
Journal of Zhejiang University. Science. B 2006;7(2):161-161
Due to lack of appreciation of the complexities of the interactions between nature and nurture, claims for the rapid improvements in medical care following the human genome project have been exaggerated. Although some progress has been made in certain fields, the full scope of genomic medicine may not be realised for many years.
Genetics, Medical
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Genomics
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Global Health
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Human Genome Project
;
Humans
;
Metaphysics