A DIFFERENTIAL SCANNING CALORIMETRY STUDY OF PLASMA IRRADIATION GRAFTING OF NASCENT POLYETHYLENE REACTOR POWDER

The melting behavior of poly(methyl methacrylate)-grafted nascent polyethylene reactor powder by plasma irradiation was studied by differential scanning calorimetry (DSC). The grafting yield ranged hom 11 to 190%. Grafting was found to lower both melting point and heat of fusion during the first run of DSC determination. The heat of fusion was used to calculate the apparent grafting yield of the samples. There was little strain induced by plasma-irradiated grafting on the surface of the polyethylene crystals. A method to determine the covalent grafting yield in the graft copolymer systems was developed. (C) 1995 John Wiley & Sons, Inc.

THE APPLICATION OF THE MPB4 THEORY TO THE INTERFACE BETWEEN 2 IMMISCIBLE ELECTROLYTE-SOLUTIONS .1. THE DIFFERENTIAL CAPACITANCE OF THE WATER NITROBENZENE INTERFACE

We use the MPB4 theory to calculate the differential capacitance of the interface between NaBr + water and tetrabutylammoniumtetraphenyl borate (TBATPB) + nitrobenzene at electrolyte concentrations of 0.01 M, 0.02 M and 0.05 M. In addition to the effects

CRYSTALLINITY OF UNIFORM OLIGO(OXYETHYLENE) MONO-N-ALKYL ETHERS STUDIED BY X-RAY-DIFFRACTION AND DIFFERENTIAL SCANNING CALORIMETRY

The crystallinity of two series of uniform oligo(oxyethylene) mono-n-alkyl ethers has been investigated: alpha-alkyl,omega-hydroxyoligo(oxyethylene)s, H(CH2)n(OCH2CH2)mOH, and alpha-alkyl,omega-methoxyoligo(oxyethylene)s, H(CH2)n(OCH2CH2)mOCH3. The hydroxy-ended oligomers formed bilayer crystals, and the methoxy-ended oligomers formed monolayer crystals. The helical oxyethylene blocks were oriented normal to the layer-crystal end-group plane, whilst the trans-planar alkyl blocks were generally tilted at an angle delta = 60-degrees. The melting temperature and enthalpy of fusion were higher for hydroxy-ended oligomers than for corresponding methoxy-ended oligomers.

Differential regulation of Sciaenops ocellatus viperin expression by intracellular and extracellular bacterial pathogens

Viperin is an antiviral protein that has been found to exist in diverse vertebrate organisms and is involved in innate immunity against the infection of a wide range of viruses. However, it is largely unclear as to the potential role played by viperin in bacterial infection. In this study, we identified the red drum Sciaenops ocellatus viperin gene (SoVip) and analyzed its expression in relation to bacterial challenge. The complete gene of SoVip is 2570 bp in length and contains six exons and five introns. The open reading frame of SoVip is 1065 bp, which is flanked by a 5'-untranslated region (UTR) of 34 bp and a 3'-UTR of 350 bp. The deduced amino acid sequence of SoVip shares extensive identities with the viperins of several fish species and possesses the conserved domain of the radical S-adenosylmethionine superfamily proteins. Expressional analysis showed that constitutive expression of SoVip was relatively high in blood, muscle, brain, spleen, and liver, and low in kidney, gill, and heart. Experimental challenges with poly(I:C) and bacterial pathogens indicated that SoVip expression in liver was significantly upregulated by poly(I:C) and the fish pathogen Edwardsiella tarda but down-regulated by the fish pathogens Listonella anguillarum and Streptococcus iniae. Similar differential induction patterns were also observed at cellular level with primary hepatocytes challenged with E. tarda, L anguillarum, and S. iniae. Infection study showed that all three bacterial pathogens could attach to cultured primary hepatocytes but only E. tarda was able to invade into and survive in hepatocytes. Together these results indicate that SoVip is involved in host immune response during bacterial infection and is differentially regulated at transcription level by different bacterial pathogens. (C) 2010 Elsevier Ltd. All rights reserved.

Relationship between differential retention of Escherichia coli and Enterococcus faecalis and variations in enzyme activity in the scallop Patinopecten yessoensis

Uptake of Escherichia coli and Enterococcus faecalis and variations of trypsin amylase activity acid phosphatase and superoxide dismutase in tissue of the scallop Patinopecten yessoensis were detected. The results showed that P. yessoensis accumulated E. faecalis in larger numbers and more rapidly than E. coli, both with the highest concentration in the digestive tract and lowest in hemolymph. Compared to E. coil, all scallops exposed to E. faecalis showed significantly higher trypsin and AMS activity. SOD activity in hemocytes and ACP activity in hemolymph was significantly higher in the treatments with 5 log(10)CFU/ml E. colt than with E. faecalis. But no significant differences in ACP activity of P. yessoensis exposed to a 3 log(10)CFU/ml inoculum of both bacteria were recorded. In conclusion, the mass retention of gut microflora in P. yessoensis is positively correlated with digestive enzymes activity and negatively correlated with ACP activity in the hemocyte. (C) 2010 Published by Elsevier Ltd.

A semi-analytical theory of coastal upwelling and jet

The general forms of the conservation of momentum, temperature and potential vorticity of coastal ocean are obtained in the x-z plane for the nonlinear ocean circulation of Boussinesq fluid, and a elliptic type partial differential equations of second order are derived. Solution of the partial differential equations are obtained under the conditions that the fluid moves along the topography. The numerical results show that there exist both upwelling and downwelling along coastline that mainly depends on the large scale ocean condition. Numerically results of the upwelling (downwelling), coastal jet and temperature front zone are favorable to the observations.

Relationships between nitrogen and phosphorus forms and ratios and the development of dinoflagellate blooms in the East China Sea

During late spring and early summer of 2005, large-scale (> 15 000 km(2)), mixed dinoflagellate blooms developed along the the coast of the East China Sea. Karenia mikimotoi was the dominant harmful algal bloom species in the first stage of the bloom (late May) and was succeeded by Prorocentrum donghaiense approximately 2 wk later. Samples were collected from different stations along both north-south and west-east transects, from the Changjiang River estuary to the south Zhejiang coast, during 3 cruises of the Chinese Ecology and Oceanography of Harmful Algal Blooms Program, before and during the bloom progression. Nitrogen isotope tracer techniques were used to measure rates of NO3-, NH4+, urea, and glycine uptake during the blooms. High inorganic nitrogen (N), but low phosphorus (P) loading from the Changjiang River led to high dissolved inorganic N:dissolved inorganic P ratios in the sampling area and indicate the development of P limitation. The rates of N-15-uptake experiments enriched with PO43- were enhanced compared to unamended samples, suggesting P limitation of the N-uptake rates. The bloom progression was related to the change in availability of both organic and inorganic N and P. Reduced N forms, especially NH4+, were preferentially taken up during the blooms, but different bloom species had different rates of uptake of organic N substrates. K mikimotoi had higher rates of urea uptake, while P. donghaiense had higher rates of glycine uptake. Changes in the availability of reduced N and the ratios of N:P in inorganic and organic forms were suggested to be important in the bloom succession. Nutrient ratios and specific uptake rates of urea were similar when compared to analogous blooms on the West Florida Shelf.

Forms and functions of inorganic carbon in the Jiaozhou Bay sediments

Inorganic carbon forms and their influencing factors, mutual transformation and contribution to carbon cycling in the Jiaozhou Bay sediments were discussed. The results show that inorganic carbon in sediments could be divided into five forms: NaCl form, NH3 center dot H2O form, NaOH form, NH2OH center dot HCl form and HCl form. Thereinto, NH2OH center dot HCl form and HCl form account for more than 70% of total inorganic carbon. There was close relationship among every form of inorganic carbon and their correlativity was clearly different with different sedimentary environment except the similar strong positive correlation among NH2OH center dot HCl form, HCl form and total inorganic carbon in all regions of the Jiaozhou Bay. All forms of inorganic carbon were influenced by organic carbon, pH, Eh, Es, nitrogen and phosphorus in sediments, but their influence had different characteristics in different regions. Every farm of inorganic carbon transformed into each other continuously during early diagenesis of sediments and the common phenomenon was that NaCl form, NH3 center dot H2O form, NaOH form and NH2OH center dot HCl form might transform into steady HCl form. NaCl form, NH3 center dot H2O form, NaOH form and NH2OH center dot HCl form could participate in carbon recycle and they are potential carbon source; HCl form may be buried for a long time in sediments, and it may be one of the final resting places of atmospheric CO2. Inorganic carbon which entered into sediments was about 4.98 x 10(10) g in the Jiaozhou Bay every year, in which about 1.47x10(10) g of inorganic carbon might be buried for a long time and about 3.51. x 10(10) g of inorganic carbon might return into seawater and take part in carbon recycling.

Characteristics of nitrogen forms in the southern Huanghai Sea surface sediments

The distributions of different forms of nitrogen in the surface sediments of the southern Huanghai Sea are different and affected by various factors. The contents of IEF-N, SOEF-N and TN gradually decrease eastward, and those of SAEF-N northward, while those of WAEF-N westward. Around the seaport of the old Huanghe (Yellow) River, the contents of both SOEF-N and TN are the highest. Among all the factors, the content of fine sediment is the predominant factor to affect the distributions of different forms of nitrogen. The contents of IEF-N, SOEF-N, and TN have visibly positive correlation with the content of fine sediments, and the correlative coefficient is 0.68, 0.58 and 0.71 respectively, showing that the contents of the three forms of nitrogen increase with those of fine sediments. The content of WAEF-N is related to that of fine sediments to a certain extent, with a correlative coefficient of 0.35; while the content of SAEF-N is not related to that of fine sediments, showing that the content of SAEF-N is not controlled by fine grain-size fractions of sediments. In addition, the distributions of different forms of nitrogen are also interacted one another, and the contents of IEF-N and SOEF-N are obviously affected by TN, while those of inorganic nitrogen (WAEF-N, SAEF-N and IEF-N) are not affected by SOEF-N and TN obviously, although they are interacted each other.

Characteristics of nitrogen forms in the surface sediments of southwestern Nansha Trough, South China Sea

The area of the southwestern Nansha Trough is one of the most productive areas of the southern South China Sea. It is a typical semi-deep sea area of transition from shoal to abyssal zone. To understand distributions and roles of nitrogen forms involved in biogeochemical cycling in this area, contents of nitrogen in four extractable forms: nitrogen in ion exchangeable form (IEF-N), nitrogen in weak acid extractable form (WAEF-N), nitrogen in strong alkali extractable form (SAEF-N) and nitrogen in strong oxidation extractable form (SOEF-N), as well as in total nitrogen content (TN) in surface sediments were determined from samples collected from the cruise in April-May 1999. The study area was divided into three regions (A, B and C) in terms of clay sediment (< 4 mu m) content at < 40%, 40%-60% and > 60%, respectively. Generally, region C was the richest in the nitrogen of all forms and region A the poorest, indicating that the finer the grain size is, the richer the contents of various nitrogen are. The burial efficiency of total nitrogen in surface sediments was 28.79%, indicating that more than 70% of nitrogen had been released and participated in biogeochemical recycling through sediment-water interface.

吗啡相关情境线索的形成及效应表达的神经基础——海马与基底外侧杏仁核在其中的作用

Drug-associated cue-induced relapse to drug seeking causes most difficulties of therapy for drug addiction. Addicts are exposed to two forms of environmental stimuli during drug-taking: contextual stimuli (e.g. a house in which the drug is consumed) and discrete stimuli (DS, e.g. a crack pipe or a syringe for drug). These stimuli become contextual cues and discrete cues, respectively. The incentive value of contextual cues plays a great role in opiates relapse. Compared with drug self-administration model, conditioned place preference (CPP) reflects the approach behavior for drug cues, not concerned with acquisition of operant behaviors. The present study aimed to investigate the role of basolateral amygdala (BLA) and hippocampus in the effect of opiates-related contextual cues using CPP model. Establishing DS-dependent or contextual cues-dependent CPP, the effect of BLA or hippocampus inactivation prior to training phase on acquisition of contextual cues-opiates association was evaluated. Inactivation prior to test phase was used to evaluate roles of BLA and hippocampus in expression of contextual cues-dependent morphine CPP. The main results were as follows: Inactivation of BLA or dorsal hippocampus selectively impaired acquisition of contextual cue-dependent CPP, but inactivation of ventral hippocampus had no impact on acquisition of either DS-dependent or contextual cue-dependent morphine CPP. Inactivation of BLA selectively inhibited expression of contextual cue-depended CPP. Inactivation of ventral hippocampus inhibited expression of both DS-dependent and contextual cue-dependent morphine CPP. These results suggest that BLA and dorsal hippocampus contribute to contextual cue association with opiates but not DS-opiates association. BLA and ventral hippocampus play important roles in incentive value of contextual cues. The present study provides more information for the neurological substrates underlying contextual cues associated with opiates.