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71.
This study presents the characterization of myo-inositol (MI) uptake in rat intestine as evaluated by use of purified membrane preparations. Three secondary active MI cotransporters have been identified; two are Na(+) coupled (SMIT1 and SMIT2) and one is H(+) coupled (HMIT). Through inhibition studies using selective substrates such as d-chiro-inositol (DCI, specific for SMIT2) and l-fucose (specific for SMIT1), we show that SMIT2 is exclusively responsible for apical MI transport in rat intestine; rabbit intestine appears to lack apical transport of MI. Other sugar transport systems known to be present in apical membranes, such as SGLT1 or GLUT5, lacked any significant contribution to MI uptake. Functional analysis of rat SMIT2 activity, via electrophysiological studies in Xenopus oocytes, demonstrated similarities to the activities of SMIT2 from other species (rabbit and human) displaying high affinities for MI (0.150 +/- 0.040 mM), DCI (0.31 +/- 0.06 mM), and phlorizin (Pz; 0.016 +/- 0.007 mM); low affinity for glucose (36 +/- 7 mM); and no affinity for l-fucose. Although these functional characteristics essentially confirmed those found in rat intestinal apical membranes, a unique discrepancy was seen between the two systems studied in that the affinity constant for glucose was approximately 40-fold lower in vesicles (K(i) = 0.94 +/- 0.35 mM) than in oocytes. Finally, the transport system responsible for the basolateral efflux transporter of glucose in intestine, GLUT2, did not mediate any significant radiolabeled MI uptake in oocytes, indicating that this transport system does not participate in the basolateral exit of MI from small intestine.  相似文献   
72.
The effect of salt concentration (NaCl) on growth, fluorescence, photosynthetic activities and pigment content of the cyanobacterium Arthrospira platensis has been investigated over 15 days. It has been observed that high NaCl concentration induces an increase of the growth, photosynthetic efficiency (α), phycobilin/chlorophyll ratio and a slight decrease of dark respiration and compensation points. Moreover, high NaCl concentration enhances photosystem II (PSII) activity compared to photosystem I (PSI). Results show that the phycobilin-PSII energy transfer compared to the chlorophyll-PSII (F695,600/F695,440) increases. However, data obtained about the maximal efficiency of PSII photochemistry are controversial. Indeed, the Fv/Fm ratio decreases in salt adapted cultures, while at the same time the trapping flux per PSII reaction center (TR0/RC) and the probability of electron transport beyond QA (0) remain unchanged at the level of the donor and the acceptor sites of PSII. This effect can be attributed to the interference of phycobilin fluorescence with Chl a when performing polyphasic transient measurements.  相似文献   
73.
The present study aimed to investigate the diurnal variation of postural stability, attentional capacities, and oral temperature in 5–6-year-old tennis players. A total of 24 young children were divided into two groups: Twelve tennis players with 2 years of training experience and twelve sedentary children without previous experience in any type of sport. They were asked to maintain an upright bipedal stance on a static force platform with eyes open (EO) and eyes closed (EC) at 07:00, 10:00, 14:00, and 18:00 h. Postural stability was evaluated by the center of pressure (CoP), surface area (CoPArea), CoP mean velocity (CoPVm), and Romberg’s index (RI). Oral temperature and simple reaction time (SRT) were also recorded at the beginning of each test session. Postural stability in 5–6-year-old tennis players was low at 07:00 h and improved at 10:00 h (p < 0.001); then, it worsened at 14:00 h (p < 0.001) and improved again at 18:00 h (p < 0.001) as found in sedentary children. This rhythm was also close to that of SRT in both groups. Body temperature increased significantly (p < 0.001) from the morning to the afternoon in both groups. However, the peak of postural performance, the peak of attentional capacities, and the greatest vision contribution to maintain balance observed at 18:00 h were only found in the trained group. Moreover, young tennis players were more stable (p < 0.001) and more attentive (p < 0.01) than sedentary ones at 18:00 h. The amplitude of the diurnal rhythm of CoP parameters was significantly larger (p < 0.01) in trained children compared to sedentary ones (43.1 ± 8.5 vs 31.7 ± 8.3 for the CoPArea; 27.5 ± 7.4 vs 17.7 ± 8.2 for the CoPVm). Therefore, time-of-day has a significant effect on static postural stability and attentional capacities in young tennis players with better performances in the late afternoon (habitual hour of training). Thus, we recommend planning some training sessions at 07:00 and/or 14:00 h to optimize postural stability at the time of its batyphase and to reduce the incidence of fall-related injury risks during this critical age in athletic environments.  相似文献   
74.
Media optimisation was attempted for β-glucuronidase production from a newly and locally isolated (Oxfordshire, UK) fungal strain of Ganoderma applanatum. Both fungal growth and β-glucuronidase activity were found to be greatly affected by varying the carbon or the nitrogen source with gum arabic and yeast extracts being the best carbon and nitrogen sources, respectively. Their concentrations were optimised at 8 g L−1 for the former and 2 g L−1 for the latter.

Work then proceeded to enhance the yield of β-glucuronidase in a controlled environment. Control, batch and fed-batch cultivations were performed in 2-L bioreactors using the optimised medium supplemented with cellobiuronic acid as inducer. Time profiles of biomass dry weight, carbohydrate consumption and β-glucuronidase production were obtained and the results showed that production of β-glucuronidase was noticeably increased by the addition of cellobiuronic acid in both batch and fed-batch fermentations. Although the addition did not produce a variation in the pattern of growth seen between control, and induced fermenters, higher levels of the enzyme were attained when adopting a fed-batch process with 1.09 U mL−1 of culture, corresponding to a 5-fold enhancement in β-glucuronidase production rate compared with batch fermentation.  相似文献   

75.
An extracellular bleach stable protease producing strain was isolated from marine water sample and identified as Bacillus mojavensis A21 on the basis of the 16S rRNA gene sequencing and biochemical properties. The A21 alkaline protease was purified from the culture supernatant to homogeneity using acetone precipitation, Sephadex G-75 gel filtration and CM-Sepharose ion exchange chromatography, with a 6.43-fold increase in specific activity and 16.56% recovery. The molecular weight of the purified enzyme was estimated to be 20 kDa by SDS-PAGE and gel filtration. The enzyme was highly active over a wide range of pH from 7.0 to 13.0, with an optimum at pH 8.5. The relative activities at pH 11.0 and 12.0 were about 80 and 71.7% of that obtained at pH 8.5. The enzyme was extremely stable in the pH range of 7.0–12.0. It exhibited maximal activity at 60 °C. The thermostability of the enzyme was significantly increased by the addition of CaCl2. The activity of the enzyme was totally lost in the presence of PMSF, suggesting that the purified enzyme is a serine protease.The N-terminal amino acid sequence of the first 20 amino acids of the purified protease was DINGGGATLPQKLYQTSGVL. B. mojavensis A21 protease showed low homology with bacterial peptidases, suggesting that the enzyme is a new protease.The alkaline protease showed high stability towards anionic (0.1% SDS) and non-ionic (1 and 5% Tween 80 and 1% Triton X-100) surfactants. In addition, the enzyme was relatively stable towards oxidizing agents, retaining more than 79 and 70% of its initial activity after 1 h incubation in the presence of 1% H2O2 and 0.1% sodium perborate, respectively. The enzyme showed excellent stability with a wide range of commercial solid and liquid detergents at 30 and 40 °C. Considering its promising properties, B. mojavensis A21 may find potential application in laundry detergents.  相似文献   
76.
A novel fibrinolytic enzyme, subtilisin BSF1, from a newly isolated Bacillus subtilis A26 was purified, characterized and the gene was isolated and sequenced. The subtilisin BSF1 was purified to homogeneity by five-step procedure with a 4.97-fold increase in specific activity and 6.28% recovery. The molecular weight of the purified enzyme was estimated to be 28 kDa by SDS-PAGE and gel filtration. The purified enzyme exhibited high fibrinolytic activity on fibrin agar plates.Interestingly, the enzyme was highly active over a wide range of pH from 7.0 to 12.0, with an optimum at pH 9.0. The relative activities at pH 10.0 and 11.0 were 97.8% and 85.2% of that at pH 9.0. The optimum temperature for enzyme activity was 60 °C. The activity of subtilisin BSF1 was totally lost in the presence of PMSF, suggesting that the purified enzyme is a serine protease. The N-terminal amino acid sequence of the first 11 amino acids (aa) of the purified fibrinolytic enzyme was AQSVPYGISQI.The bsf1 gene encoding the subtilisin BSF1 was isolated and its DNA sequence was determined. The bsf1 gene consisted of 1146 bp encoding a pre-pro-protein of 381 amino acids organized into a signal peptide (29 aa), a pro-peptide (77 aa) and a mature domain (275 aa). The deduced amino acids sequence of the mature enzyme (BSF1) differs from those of nattokinase from B. subtilis natto and subtilisin DFE from Bacillus amyloliquefaciens DC-4 by 5 and 39 amino acids, respectively.  相似文献   
77.
The Homez gene encodes a protein with three atypical homeodomains and two leucine zipper motifs of unknown function. Here we show that during neurula stages, Xenopus Homez is broadly expressed throughout the neural plate, the strongest expression being detected in the domains where primary neurons arise. At later stages, Homez is maintained throughout the central nervous system in differentiating progenitors. In accordance with this expression, Homez is positively regulated by neural inducers and by Ngnr1 and negatively by Notch signaling. Interference with Homez function in embryos by injection of an antisense morpholino oligonucleotide results in the specific disruption of the expression of late neuronal markers, without affecting the expression of earlier neuronal and early neurectodermal markers. Consistent with this finding, Homez inhibition also interferes with the expression of late neuronal markers in Ngnr1 overexpressing animal cap explants and in Notch inhibited embryos. In gain of function experiments, Homez inhibits the expression of late neuronal markers but has no effect on earlier ones. These data suggest a role for Homez in neuronal development downstream of proneural/neurogenic genes.  相似文献   
78.
This study reports on the polymorphism of 15 allozyme loci in Ruditapes decussatus clams collected from 11 locations along the Tunisian coasts. We concentrated our sampling effort around the Siculo-Tunisian region to verify if any population structuring exists in this region and to identify the factors that have shaped this structure. Measurements of genetic diversity were quantified both within and between populations, and the geographic variability of gene frequencies was analyzed. Our study shows that the Siculo-Tunisian Strait is an important genetic boundary between eastern and western regions, which agrees with findings for a variety of other species. We suggest that vicariance is a predominant factor shaping the current distribution of genetic diversity of R. decussatus, and the mixing of divergent gene pools from the eastern and western regions still seems to be limited by some physical and/or biological factors.  相似文献   
79.
OBJECTIVE: Delphi technique is a structured process commonly used to developed healthcare quality indicators, but there is a little recommendation for researchers who wish to use it. This study aimed 1) to describe reporting of the Delphi method to develop quality indicators, 2) to discuss specific methodological skills for quality indicators selection 3) to give guidance about this practice. METHODOLOGY AND MAIN FINDING: Three electronic data bases were searched over a 30 years period (1978-2009). All articles that used the Delphi method to select quality indicators were identified. A standardized data extraction form was developed. Four domains (questionnaire preparation, expert panel, progress of the survey and Delphi results) were assessed. Of 80 included studies, quality of reporting varied significantly between items (9% for year's number of experience of the experts to 98% for the type of Delphi used). Reporting of methodological aspects needed to evaluate the reliability of the survey was insufficient: only 39% (31/80) of studies reported response rates for all rounds, 60% (48/80) that feedback was given between rounds, 77% (62/80) the method used to achieve consensus and 57% (48/80) listed quality indicators selected at the end of the survey. A modified Delphi procedure was used in 49/78 (63%) with a physical meeting of the panel members, usually between Delphi rounds. Median number of panel members was 17(Q1:11; Q3:31). In 40/70 (57%) studies, the panel included multiple stakeholders, who were healthcare professionals in 95% (38/40) of cases. Among 75 studies describing criteria to select quality indicators, 28 (37%) used validity and 17(23%) feasibility. CONCLUSION: The use and reporting of the Delphi method for quality indicators selection need to be improved. We provide some guidance to the investigators to improve the using and reporting of the method in future surveys.  相似文献   
80.

Objective

Measuring the quality of inpatient obstetrical care using quality indicators is becoming increasingly important for both patients and healthcare providers. However, there is no consensus about which measures are optimal. We describe a modified Delphi method to identify a set of indicators for continuously monitoring the quality of maternity care by healthcare professionals.

Methodology and Main Findings

An international French-speaking multidisciplinary panel comprising 22 obstetricians-gynaecologists, 12 midwives, and 1 paediatrician assessed potential indicators extracted from a medical literature search, using a two-round Delphi procedure followed by a physical meeting. Each panellist rated each indicator based on validity and feasibility. In the first round, 35 panellists from 5 countries and 20 maternity units evaluated 26 indicators including 15 related to the management of the overall population of pregnant women, 3 to the management of women followed from the first trimester of pregnancy, 2 to the management of low-risk pregnant women, and 6 to the management of neonates. 25 quality indicators were kept for next step. In the second round, 27 (27/35: 77%) panellists selected 17 indicators; the remaining 8 indicators were discussed during a physical meeting. The final set comprised 18 indicators.

Conclusion

A multidisciplinary panel selected indicators that reflect the quality of obstetrical care. This set of indicators could be used to assess and monitor obstetrical care, with the goal of improving the quality of care in maternity units.  相似文献   
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