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41.
Summary [2 m+ and [2m°] yeast were transformed to stable leucine prototrophy with the hybrid yeast — E. coli plasmid, pJDB219. This plasmid contains the entire sequence of the endogenous 2 m yeast DNA plasmid in addition to the yeast nuclear LEU2
+ gene and the Co1E1 derivative, pMB9. In the [2 m+] transformants, a new wholly yeast LEU2
+ plasmid, pYX, was generated, probably by a recombination event between pJDB219 and 2 m DNA. The plamid, pYX, in the absence of 2 m DNA, was found to exist in equimolar amounts of two forms, A and B, which probably arise by intramolecular recombination across the inverted repeat sequences of the 2 m DNA portion of the plasmid. pJDB219 was found to require the presence of 2 m DNA to undergo this intramolecular recombination. The results suggest that 2, m DNA and pYX code for a gene product required in this recombination event which pJDB219 cannot produce. 相似文献
42.
A common ancestor for COCH related cochleovestibular (DFNA9) patients in Belgium and The Netherlands bearing the P51S mutation 总被引:6,自引:0,他引:6 下载免费PDF全文
43.
Molecular profiling of giant cell tumor of bone and the osteoclastic localization of ligand for receptor activator of nuclear factor kappaB 总被引:1,自引:0,他引:1 下载免费PDF全文
44.
Soy isoflavones, body composition, and physical performance 总被引:2,自引:0,他引:2
OBJECTIVES: Physiologic changes, occurring during the process of aging, can have serious health consequences, such as increased risk of chronic disease and disability. Decline in estradiol levels after menopause is hypothesized to contribute to this risk. Thus, hormone therapy (HT) might prevent or delay those changes. However, HT has serious side effects and alternative approaches are needed. METHODS: We performed a 12-month double-blind randomized trial comparing soy protein containing 99mg isoflavones (aglycone weights) with milk protein (placebo) daily in 202 postmenopausal women aged 60-75 years. Endpoints were body composition, and physical performance. Randomization resulted in reasonable well-balanced groups, 153 (76%) women completed the trial. Compliance was good (plasma genistein levels 55 +/- 101 and 1259 +/- 1610 nmol/L for placebo and soy group, respectively). The changes in the endpoints during the intervention period among the two intervention groups were analyzed. RESULTS: Body mass index (BMI) and waist-to-hip ratio did not change during intervention. Handgrip strength at the final visit was slightly worse in the soy group compared to the placebo group (-0.45 kg (95% C.I.: -2.5, 1.6 kg; p = 0.7), but this difference was not statistically significant. Self-reported functional status, mobility and physical performance, all slightly improved during intervention but there were no differences between the groups. CONCLUSIONS: The results of the present trial do not support the view that soy isoflavones have favorable effects on body composition and physical performance in postmenopausal women. 相似文献
45.
Immobilization of acetylcholinesterase and choline oxidase in/on pHEMA membrane for biosensor construction 总被引:1,自引:0,他引:1
In this study, acetylcholinesterase (AChE) and choline oxidase (ChO) were co-immobilized on poly(2-hydroxyethyl methacrylate) (pHEMA) membranes with the aim of using them in biosensor construction. pHEMA membranes were prepared with the addition of different salts in different HEMA: aqueous solution ratios and characterized in terms of porosity, thickness. permeability, and mechanical properties. Membranes prepared in the presence of SnCl4 were found to be superior in terms of porosity and permeability and were chosen as the immobilization matrix. Immobilization of the enzymes was achieved both by entrapment and surface attachment via epichlorohydrin (Epi) and Cibacron Blue F36A (CB) activation. The effect of immobilization on enzyme activity was evaluated by the comparison of Km and Vmax values for the free and immobilized bi-enzyme systems. The increase in Km was negligible (1.08-fold) for the bi-enzyme system upon immobilization on surface but was 2.12-fold upon entrapment. Specific activity of the free enzyme system was found to be 0.306 mV s(-1) microg(-1) ChO while it was 0.069 (4.43-fold decrease) for entrapped and 0.198 (1.54 fold decrease) for CB-Epi immobilized enzymes. The performance of immobilized enzymes in different buffer types, pH, and temperature conditions were evaluated. The best enzyme activity was obtained at pH 9.0. Activity of the enzymes was found to increase with increasing temperature (in the range 25-40 degrees C). 相似文献
46.
47.
Strategic control and medial frontal negativity: beyond errors and response conflict 总被引:6,自引:0,他引:6
Errors in timed choice tasks typically produce an error-related negativity (ERN) in the event-related potential (ERP). The error specificity of the ERN has been challenged by studies showing a correct response negativity (CRN). Forty-five participants engaged in a flanker task in which both compatibility between flankers and target and the probability of compatible flankers were manipulated. Correct responses elicited a CRN, the amplitude of which increased with the degree of mismatch between the presence of conflict and conflict probability, even on low-conflict (compatible) trials. The fronto-central N2 component was larger on high-conflict (incompatible) correct response trials. However, in contrast to some recent accounts, this N2 was largest for highly probable stimuli. These findings suggest revision to models of the effects of conflict on response-related negativity to account for strategic adjustments made in preparation for the response. 相似文献
48.
Karin Ellen Veldkamp Kok P. M. Van Kessel Jan Verhoef Jos A. G. Van Strijp 《Inflammation》1997,21(5):541-551
Phagocytes play a major role in host defense against staphylococci as well as in the pathophysiology of Gram-positive septic shock. In Gram negative sepsis, the main mediator, LPS exerts its effects as easily suspendable mediator. In Gram positive sepsis the main mediator is still not found, therefore we studied the interaction of soluble staphylococcal products with phagocytes. Staphylococcus aureus supernates (SaS) were harvested from several laboratory and clinical strains that were grown to late-log phase. These supernates upregulated CD11b/CD18 expression on human neutrophils even in a 100-fold dilution. SaS also induced the release of TNF- and IL-1 by human monocytes. Control experiments excluded peptidoglycan, lipoteichoic acid, and toxin, leucocidin, TSST-1 and all enterotoxins as sole mediators. Endotoxin contamination was also excluded. SaS was heat-stable; incubation for 45 minutes at 100°C did not affect its activity. Compared to purified peptidoglycan and intact bacteria per bacterium, SaS had a higher potency in stimulating phagocytes. We hypothesize that there are more—yet unknown—soluble staphylococcal products which are very important in phagocyte stimulation. 相似文献
49.
Apffel JA Van Der Louw J Lammers KR Kok WT Brinkman UA Frei RW Burgess C 《Journal of pharmaceutical and biomedical analysis》1985,3(3):259-267
The analysis of the antibiotics neomycins A, B and C was investigated. The separation of the components was studied using reversed-phase and reversed-phase ion-pair chromatography. The optimum separation was obtained utilizing a Lichrosorb RP-2 column with a mobile phase consisting of 75 mg/l sodium dodecyl sulphate, 0.5M Na2SO4 and 0.015 M sodium acetate buffer at pH 7.0. Using this mobile phase, baseline separation was obtained for all three compounds in approximately 20 min. Detection was via post-column derivatization of the analytes with ortho-phthalaldehyde in the presence of mercaptoethanol to form fluorescent iso-indole products. This system is applied to the analysis of a number of formulated products containing neomycin. 相似文献
50.
Irina Maljkovic Berry Melanie C. Melendrez Simon Pollett Katherine Figueroa Darunee Buddhari Chonticha Klungthong Ananda Nisalak Michael Panciera Butsaya Thaisomboonsuk Tao Li Tyghe G. Vallard Louis Macareo In-Kyu Yoon Stephen J. Thomas Timothy Endy Richard G. Jarman 《Emerging infectious diseases》2021,27(6):1637
Dengue control approaches are best informed by granular spatial epidemiology of these viruses, yet reconstruction of inter- and intra-household transmissions is limited when analyzing case count, serologic, or genomic consensus sequence data. To determine viral spread on a finer spatial scale, we extended phylogenomic discrete trait analyses to reconstructions of house-to-house transmissions within a prospective cluster study in Kamphaeng Phet, Thailand. For additional resolution and transmission confirmation, we mapped dengue intra-host single nucleotide variants on the taxa of these time-scaled phylogenies. This approach confirmed 19 household transmissions and revealed that dengue disperses an average of 70 m per day between households in these communities. We describe an evolutionary biology framework for the resolution of dengue transmissions that cannot be differentiated based on epidemiologic and consensus genome data alone. This framework can be used as a public health tool to inform control approaches and enable precise tracing of dengue transmissions. 相似文献