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排序方式: 共有356条查询结果,搜索用时 15 毫秒
41.
Total body bone mineral content (TBBM) is a highly discriminating determinant of bone mass. We correlated TBBM with pelvis bone mineral content (PBMC) and pelvis bone mineral density (PBMD) in 179 normal men, in order to observe whether the pelvis is an adequate region of bone mass evaluation. There was a good correlation between PBMC and TBBM (r = 927, p less than 0.001), and significant correlations between PBMD and TBBM (r = 818, p less than 0.001) and between PBMC and PBMD (r = 0.902, p less than 0.001). As the pelvis does not undergo the densitometric changes so often observed in the spine, we believe that the pelvis is appropriate as anatomic region for bone mass evaluation studies. 相似文献
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Y Revilla A Ferreira M L Villar A Bootello P Gonzalez-Porqué 《The Journal of biological chemistry》1986,261(14):6486-6491
The effect of temperature, urea, guanidine HCl, ionic and nonionic detergents, organic solvents, chaotropic salts, pH, and divalent cations has been investigated on purified human histocompatibility antigens solubilized by papain (HLApap) or solubilized by sodium cholate (HLAchol). HLApap and HLAchol are fairly stable proteins to agents acting predominantly on hydrogen bonds (temperature, urea) or hydrophobic forces (ionic and nonionic detergents). However, agents which affect ionic interactions (pH, salts, divalent cations) dissociate the molecules into subunits. A single binding site for beta 2-microglobulin with an affinity constant of 1.0 X 10(7) M-1 was found for the alpha chain of HLAchol. The dissociated subunits can be separated by affinity chromatography on Sepharose-rabbit IgG anti-human beta 2-microglobulin and reassociate in vitro when incubated under the appropriate conditions. The results point toward an important role of ionic interactions between subunits in the stabilization of the quaternary structure of HLA. 相似文献
44.
Eloy Montero Eugenia J. Olguín Roberto De Philippis Frédérique Reverchon 《Journal of applied phycology》2018,30(5):2847-2857
A number of business opportunities may arise from microalgae and wastewater treatment becoming an integrated system, as biofuels and high-added value products could be obtained simultaneously. This study, performed under controlled and non-controlled conditions, aimed at cultivating Chlorococcum sp. using a digestate from pig manure as culture medium and assessing its growth and biochemical composition for further applications. Under controlled conditions, cultures of Chlorococcum sp. were established testing various digestate dilutions (v/v). It was found that all tested dilutions (up to 8% v/v) promoted a higher biomass density, compared to the control culture in modified Bold’s Basal Medium (modified BBM). Under non-controlled conditions, it was found that the biomass productivity using the digestate diluted 5.6% v/v (23.4 mg L?1 day?1) was statistically similar to the one obtained using modified BBM (26.4 mg L?1 day?1). The volatile fatty acids contained in the digestate might have allowed mixotrophic growth for Chlorococcum sp. The intracellular lipid content in Chlorococcum sp. remained constant throughout the experiments in both, treatment and control cultures, while carbohydrates increased from 20 to 45% of the cell dry weight in the treatment and from 20 to 42% in the control one. It was concluded that conditions of nitrogen starvation and fluctuating irradiance and temperature benefit carbohydrate accumulation in this strain, since intracellular carbohydrate content increased nearly two-fold during this period. Additionally, the obtained biomass has the potential to be used as feedstock for bioethanol production. This system can meet the concept of a microalgae-based biorefinery, in which biofuels and high-added value products are produced from microalgae and wastewater. 相似文献
45.
Isolation of endophytic diazotrophic bacteria from wetland rice 总被引:16,自引:3,他引:13
Endophytic nitrogen-fixing bacteria are believed to contribute substantial amounts of N to certain gramineous crops. We have been interested to find (a) a diazotroph(s) in rice which can aggressively and stably persist and fix nitrogen in interior tissues and (b) unique rice-diazotrophic endophyte combinations. To achieve these objectives, it has been essential to find an efficient method to surface sterilize rice tissues. The method described here consists of exposing tissues to 1% Chloramine T for 15 min followed by shaking with glass beads. It has proven very efficient since (a) surface bacterial populations on the root and culm were found to be reduced by more than 90%, (b) the number of the internal colonizers was found to be significantly higher than the number of surface bacteria, and (c) colonization of root but not subepidermal tissue by gusA-marked Herbaspirillum seropedicae Z67 bacteria was found to be virtually eliminated. Nitrogen-fixing putative endophytic populations (MPN g dry wt) in the root (7.94 × 10) and culm (2.57 × 10) on field-grown IR72 plants grown in the absence of N fertilizer was found to be significantly higher near heading stage. The corresponding total putative endophyte populations in the tissues of 25 highly diverse genotypes of rice and their relatives was found to range from 10–10and 10–10, in the roots and culms, respectively. Generally, the resident bacteria were found to be non-diazotrophic, although in isolated cases diazotrophs were found, for example in the roots and culm of IR72 rice plants, or the culm of Zizaniopsis villanensis plants. The size of populations of diazotrophic bacteria in different rice genotypes was found to be 10–10 for the roots and 10–10 for the culms, respectively. The rice genera-related plants Potamophila pariffora and Rhynchoryza subulata showed the highest levels. 相似文献
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In this paper we describe a computer application that allows users from all over the world to perform chronobiological analyses with popular Internet browsers. Our application is based on the client-server philosophy, and it has been designed so as to minimize the network resources and connections to be used. Presently, our application includes several well-known data analysis techniques, mainly, that known as the cosinor method and those related. All the problems concerning security restrictions are solved, so that the user can have a real interactive chronobiological application. 相似文献
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Ian W. Pray Francesco Pizzitutti Gabrielle Bonnet Eloy Gonzales-Gustavson Wayne Wakeland William K. Pan William E. Lambert Armando E. Gonzalez Hector H. Garcia Seth E. ONeal for the Cysticercosis Working Group in Peru. 《PLoS neglected tropical diseases》2021,15(10)
BackgroundThe pork tapeworm (Taenia solium) is a parasitic helminth that imposes a major health and economic burden on poor rural populations around the world. As recognized by the World Health Organization, a key barrier for achieving control of T. solium is the lack of an accurate and validated simulation model with which to study transmission and evaluate available control and elimination strategies. CystiAgent is a spatially-explicit agent based model for T. solium that is unique among T. solium models in its ability to represent key spatial and environmental features of transmission and simulate spatially targeted interventions, such as ring strategy.Methods/Principal findingsWe validated CystiAgent against results from the Ring Strategy Trial (RST)–a large cluster-randomized trial conducted in northern Peru that evaluated six unique interventions for T. solium control in 23 villages. For the validation, each intervention strategy was replicated in CystiAgent, and the simulated prevalences of human taeniasis, porcine cysticercosis, and porcine seroincidence were compared against prevalence estimates from the trial. Results showed that CystiAgent produced declines in transmission in response to each of the six intervention strategies, but overestimated the effect of interventions in the majority of villages; simulated prevalences for human taenasis and porcine cysticercosis at the end of the trial were a median of 0.53 and 5.0 percentages points less than prevalence observed at the end of the trial, respectively.Conclusions/SignificanceThe validation of CystiAgent represented an important step towards developing an accurate and reliable T. solium transmission model that can be deployed to fill critical gaps in our understanding of T. solium transmission and control. To improve model accuracy, future versions would benefit from improved data on pig immunity and resistance, field effectiveness of anti-helminthic treatment, and factors driving spatial clustering of T. solium infections including dispersion and contact with T. solium eggs in the environment. 相似文献
50.
Brigitte Gouesnard Sandra Negro Amélie Laffray Jeff Glaubitz Albrecht Melchinger Pedro Revilla Jesus Moreno-Gonzalez Delphine Madur Valérie Combes Christine Tollon-Cordet Jacques Laborde Dominique Kermarrec Cyril Bauland Laurence Moreau Alain Charcosset Stéphane Nicolas 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2017,130(10):2165-2189