Extraction of DNA,RNA, and glycogen from oysters

The macromolecules DNA, RNA, and glycogen (CHO)_N were extracted with phenol from eggs, sperm, and the combined gill, mantle, and digestive gland tissues of oysters, using methods effective for the HeLa cells. From the eggs, most of the (CHO)_N and RNA coprecipitated in 20% ethanol whereas the DNA precipitated from 50% ethanol solutions. From the combined tissues all three macromolecules precipitated in 20% ethanol whereas from sperm they precipitated from 50% ethanol solutions. The DNA preparation from sperm was viscous and white but contained mostly (CHO)_N and some RNA. However, the DNA-(CHO)_N-RNA preparation was rendered insoluble in saline by CaPO₄ treatment and was not toxic for mammalian kidney cells in tissue culture. Thus, the methods do not yield pure nucleic acids but appear suitable for attempts to extract infectious DNA from oysters.     

Development of a multienzyme reactor for dopamine synthesis: I. enzymology and kinetics

The enzymology and kinetics of tyrosine phenol lyase (TPL) from Erwinia herbicola, and tyrosine decarboxylase (TDC) from Streptococcus faecalis have been investigated for potential use in a coimmobilized multienzyme biocatalytic system for the production of dopamine. In this multienzyme biotransformation using whole cells optimized for each of the respective enzymes, TPL catalyzes the production of 3,4-dihydroxyphenyl-L-alanine (L-dopa) from catechol, pyruvate, and ammonium, and this is subsequently decarboxylated by TDC to produce dopamine. Performing the reactions simultaneously, thereby removing L-dopa, is one option for overcoming the TPL equilibrium constraints. The enzymes have different optimal pH values, so the reaction kinetics at a compromise pH of 7.1, where both enzymes could be operated simultaneously, were investigated. For the concentration range investigated, TPL followed pseudo-first-order kinetics with respect to catechol, pyruvate, and ammonium. TDC exhibited significant product inhibition as well as inhibition by combinations of catechol and pyruvate.     

热环境下劳动时的水补充

给暴露于热环境下的家兔不同次数灌注等渗的NaCl溶液可以提高其耐热能力,在受热45分钟内,肛温增加值比对照低0.35—0.46℃,血浆渗透压在整个受热期也稳定在正常水平。热环境下的活存时间也有明显延长。热环境下(DB37—40℃,RH47—65％)做中等强度劳动(4.63卡/分)的人多次饮用含多种电解质及维生素C,蔗糖等的等渗饮料,可提高饮水量,减少失水量,其肛温增加值,心率分别比饮白开水的低0.2℃和8.7次/分(p<0.05),血浆容量的减少也比饮白水的少4.2％(p<0.05)。文中提出在热环境下劳动时,为防止热损伤发生及提高耐热能力的补水方案。     

Biodegradation of aromatic compounds and TCE by a filamentous bacteria-dominated consortium

The Michaelis-Menten biodegradation kinetics (k and Ks) of aromatic compounds and trichloroethene (TCE) by an aerobic enrichment culture grown on phenol and dominated by a unique filamentous bacterium were measured. The average k and Ks values for phenol, benzene (B), toluene (T), ethylbenzene (E), o-xylene (oX), p-xylene (pX), naphthalene and TCE in g per g VSS-d and mg L-1 were 5.72 and 0.34, 1.20 and 0.51, 2.09 and 0.47, 0.77 and 0.23, 0.61 and 0.16, 0.73 and 0.23, 0.17 and 0.18, and 0.16 and 0.18, respectively. Significant variability in these measured kinetics was noted between tests conducted over the 5-month period during which the fed-batch culture with a 5-day solids retention time was maintained; the coefficient of variation of the k and Ks values ranged from 11–43% and 4–50%, respectively. This variation was significantly greater than the method measurement error on a given date. Degradation of BTEoXpX mixtures could be described by a basic competitive inhibition model.Batch tests during which the culture was fed individual BTEX compounds showed the culture grew poorly on the xylenes and had poor subsequent xylene degradation rates. This work indicates the potential to simultaneously treat a mixture of volatile organic compounds using this consortium, and the ability to predict the mixture biodegradation rates on the basis of the individual compound biodegradation kinetics.     

Biodegradation kinetics of a mixture containing a primary substrate (phenol) and an inhibitory co-metabolite (4-chlorophenol)

Batch experiments on the simultaneous utilization of phenol (primary substrate) and 4-chlorophenol (cometabolic secondary substrate) demonstrated two critical substrate interactions. First, the cometabolic degradation of 4-chlorophenol was proportional to the rate of phenol oxidation, which provided the electrons for the initial monooxygenase reaction. Second, 4-chlorophenol inhibited the oxidation of the primary substrate, phenol. Modeling analyses of the degradation of phenol alone and of phenol and 4-chlorophenol together showed that the proportionality between phenol and 4-chlorophenol degradation rates averaged 0.1 mg 4-CP/mg phenol, which corresponds to 0.5% of the electrons generated by phenol oxidation being used as a cosubstrate for the monooxygenase reaction of 4-chlorophenol. In addition, modeling analyses suggest that 4-chlorophenol was a noncompetitive inhibitor of phenol oxidation for high phenol concentrations, but a competitive inhibitor for low phenol concentrations.Abbreviations GC gas chromatography - FID flame-ionization detector - DO dissolved oxygen - 4-CP 4-chlorophenol - Ph phenol - RLS relative least squares criterion - NAD nicotinamide adenine dinucleotide - NADP nicotinamide adenine dinucleotide phosphate     

Treatment Methods for Wine-Related and Distillery Wastewaters: A Review

A large and increasing volume of wastewater is produced globally by the winery and distillery industries. These wastewaters are generally acidic, high in chemical oxygen demand (COD) and color, and may contain phenolic compounds that can inhibit biological treatment systems. Treatment of distillery and phenolic compound–rich wastewaters by physicochemical, aerobic biological systems and hybrid treatment methods are discussed, as well as products derived from fungal treatment. White-rot fungi have been shown to exhibit unique biodegradation capabilities, primarily due to their production of extracellular and broad substrate range enzymes that are capable of mineralizing lignin, a recalcitrant biopolymer. One of these enzymes, laccase, catalyses the oxidation of various organic compounds with the subsequent reduction of molecular oxygen to water. Laccase synthesis, induction, and inhibition are discussed with the utilization of waste residues for laccase production and the enzyme's potential industrial applications. Distillery wastewaters offer a unique, presterilized, potential growth substrate for the production of lignolytic enzymes such as laccase. Compounds may be utilized for enzyme and biomass production resulting in remediation by the growing fungus.     

Steroids interfere with human carbonic anhydrase activity by using alternative binding mechanisms

Bile acids have been shown to inhibit human (h) carbonic anhydrases (CA, EC 4.2.1.1) along the gastrointestinal tract, including hCA II. The elucidation of the hormonal inhibition mechanism of the bile acid cholate to hCA II was provided in 2014 by X-ray crystallography. Herein, we extend the inhibition study to a wealth of steroids against four relevant hCA isoforms. Steroids displaying pendants and functional groups of the carboxylate, phenolic or sulfonate types appended at the tetracyclic ring were shown to inhibit the cytosolic CA II and the tumor-associated, transmembrane CA IX in a medium micromolar range (38.9–89.9?µM). Docking studies displayed the different chemotypes CA inhibition mechanisms. Molecular dynamics (MD) gave insights on the stability over time of hyocholic acid binding to CA II.     

Strong Visible‐Light Absorption and Hot‐Carrier Injection in TiO2/SrRuO3 Heterostructures

Correlated electron oxides prove a diverse landscape of exotic materials' phenomena and properties. One example of such a correlated oxide material is strontium ruthenate (SrRuO₃) which is known to be a metallic itinerant ferromagnet and for its widespread utility as a conducting electrode in oxide heterostructures. We observe that the complex electronic structure of SrRuO₃ is also responsible for unexpected optical properties including high absorption across the visible spectrum (commensurate with a low band gap semiconductor) and remarkably low reflection compared to traditional metals. By coupling this material to a wide band gap semiconductor (TiO₂) we demonstrate dramatically enhanced visible light absorption and large photocatalytic activities. The devices function by photo‐excited hot‐carrier injection from the SrRuO₃ to the TiO₂ and the effect is enhanced in thin films due to electronic structure changes. This observation provides an exciting new approach to the challenge of designing visible‐light photosensitive materials.     

Induced resistance against Alternaria brassicae blight of mustard through plant extracts

An experiment was conducted to study the effect of plant extracts on soluble sugar, soluble phenol and defence-related enzymes response against Alternaria blight in mustard crop. The efficacy of six selected plant extracts (5 and 10%) used as foliar sprays at 60 and 70 days after sowing and mustard leaves was used for investigation. The results indicate that soluble phenol and sugar content in mustard leaves significantly increases in response to spraying of Azadirachta indica seed kernel, Calotropis procera and A. indica leaf extracts. The soluble protein, viz. peroxidase, polyphenol oxidase and phenylalanine ammonia lyase content, was higher in mustard leaves sprayed with C. procera leaves extract, A. indica seed kernel and Allium sativum bulb extract.     

Simple, sensitive and on-line fluorescence monitoring of photodegradation of phenol and 2-naphthol.

A simple molecular fluorescence spectrometer based on a hand-held CCD spectrometer was constructed for on-line monitoring of the photodegradation of pollutants. A high-pressure Hg vapour lamp was used for the UV photodegradation and simultaneously for the fluorescence excitation. Phenol and 2-naphthol were selected as the targets for this preliminary study. Using peak fluorescence, figures of merit for monitoring these two hydroxybenzene were obtained. Degradation efficiencies with different homogeneous photocatalyst systems were investigated, including UV only, UV/H(2)O(2) and UV/Fe(3+) degradation systems. The kinetics modelling showed that their photodegradation fitted the Langmuir-Hinshelwood model. Results showed that the proposed method is potentially applicable to both on-line real-time monitoring and field analysis.