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151.
Fluorescence polarization is one of the most commonly used homogeneous assay principles in drug discovery for screening of potential lead compounds. In this article, the fluorescence polarization technique is combined with 2-photon excitation of fluorescence. Theoretically, the use of 2-photon excitation of fluorescence increases the volumetric sensitivity and polarization contrast of fluorescence polarization assays. The work in this report demonstrates these predictions for an estrogen receptor ligand binding assay.  相似文献   
152.
Reindeer Rangifer tarandus L. grazing shapes forest vegetation, microclimate, and soil respiration in Lapland, especially due to grazing on lichens (Cladina). We studied how these changes and their magnitude affect ground‐dwelling species of beetle families Carabidae (predators) and Curculionidae (herbivores), by using pitfall traps to collect invertebrates from pairs of grazed and ungrazed study plots over a wide range of site types. Changes in abundance, composition, richness and diversity of beetle assemblage were tested in relation to magnitude of the impacts on vegetation. The species compositions of Carabidae and Curculionidae differed between grazed and ungrazed plots in all sites. The relative difference between grazed and ungrazed plots in the number of individuals increased linearly with the impact of reindeer on vegetation cover. Carabid beetles, as a family, were more common in grazed plots in all sites. Curculionid beetles were more common in ungrazed plots in the birch dominated sites. This difference was mainly due to the species that feeds on deciduous leaves. In the pine dominated sites with high Cladina cover and more changes in ground vegetation, the number of curculionids feeding on conifers was higher in grazed plots. Species richness and diversity (H’) of both families were higher in grazed plots. Of the total 27 species, 11 were found only in grazed plots, while not a single species was found only in ungrazed plots. The relative difference between plots in diversity and evennes (H’/H'max) had humped response to the difference in Cladina cover. The diversity values were greater in grazed plots at the intermediate levels of grazing impact, and only in sites with very low or extremely high Cladina cover difference was the diversity higher in ungrazed plots. The response of beetle diversity resembled the hypotheses suggested for the relationship between grazing and vegetation diversity: greatest positive effect at intermediate grazing intensity and negative effects at unproductive sites.  相似文献   
153.
Trichoderma reesei strains were constructed for production of elevated amounts of endoglucanase II (EGII) with or without cellobiohydrolase I (CBHI). The endoglucanase activity produced by the EGII transformants correlated with the copy number of the egl2 expression cassette. One copy of the egl2 expression cassette in which the egl2 was under the cbh1 promoter increased production of endoglucanase activity 2.3-fold, and two copies increased production about 3-fold above that of the parent strain. When the enzyme with elevated EGII content was used, an improved stonewashing effect on denim fabric was achieved. A T. reesei strain producing high amounts of EGI and -II activities without CBHI and -II was constructed by replacing the cbh2 locus with the coding region of the egl2 gene in the EGI-overproducing CBHI-negative strain. Production of endoglucanase activity by the EG-transformant strain was increased fourfold above that of the host strain. The filter paper-degrading activity of the endoglucanase-overproducing strain was lowered to below detection, presumably because of the lack of cellobiohydrolases.  相似文献   
154.
Anterolateral thigh flap for postmastectomy breast reconstruction   总被引:4,自引:0,他引:4  
Most postmastectomy defects are reconstructed by use of lower abdominal-wall tissue either as a pedicled or free flap. However, there are some contraindications for using lower abdominal flaps in breast reconstruction, such as inadequate soft-tissue volume, previous abdominoplasty, lower paramedian or multiple abdominal scars, and plans for future pregnancy. In such situations, a gluteal flap has often been the second choice. However, the quality of the adipose tissue of gluteal flaps is inferior to that of lower abdominal flaps, the pedicle is short, and a two-team approach is not possible because creation of the gluteal flap requires that the patient's position be changed during the operation. In 2000, five cases of breast reconstructions were performed with anterolateral thigh flaps in the authors' institution. Two of them were secondary and three were immediate unilateral breast reconstructions. The mean weight of the specimen removed was 350 g in the three patients who underwent immediate reconstruction, and the mean weight of the entire anterolateral thigh flap was 410 g. Skin islands ranged in size from 4 x 8 cm to 7 x 22 cm, with the underlying fat pad ranging in size from 10 x 12 cm to 14 x 22 cm. The mean pedicle length was 11 cm (range, 7 to 15 cm). All flaps were completely successful, except for one that involved some fat necrosis. The quality of the skin and underlying fat and the pliability of the anterolateral thigh flap are much superior to those of gluteal flaps and are similar to those of lower abdominal flaps. In thin patients, more subcutaneous fat can be harvested by extending the flap under the skin. Use of a thigh flap allows a two-team approach with the patient in a supine position, and no change of patient position is required during the operation. However, the position of the scar may not be acceptable to some patients. Therefore, when an abdominal flap is unavailable or contraindicated, the creation of an anterolateral thigh flap for primary and secondary breast reconstruction is an alternative to the use of lower abdominal and gluteal tissues.  相似文献   
155.
We experimentally studied the role of local adaptation and the co-evolutionary relationship between an annual, endangered root hemiparasite Euphrasia rostkoviana and its main host Agrostis capillaris. According to our hypothesis, the existence of local adaptation in hemiparasites should be observable in better hemiparasite performance when attached to A. capillaris hosts originating From Euphrasia populations. After one month of growth, the height and the number of leaves of hemiparasites were not affected by the origin of their hosts. The differences in growth were due to between population effects. The situation remained constant after three months. Hemiparasite biomass was not affected by the origin of the hosts. The percentage of hemiparasites surviving after one. two and three months was not affected by the origin of the hosts although there was a weak tendency towards better survival of hemiparasites with familiar hosts than with unfamiliar hosts. All variables used to measure hemiparasite performance during its complete life-cycle gave only limited support for the local adaptation hypothesis. Nevertheless, the familiar hosts suffered less from parasitism as indicated by their higher biomass after the experiment. This suggests that there may be some interactions between hemiparasites and their hosts based on their spatial population structure and common history as competitors.  相似文献   
156.

Background

The relationship between work-related stress and alcohol intake is uncertain. In order to add to the thus far inconsistent evidence from relatively small studies, we conducted individual-participant meta-analyses of the association between work-related stress (operationalised as self-reported job strain) and alcohol intake.

Methodology and Principal Findings

We analysed cross-sectional data from 12 European studies (n = 142 140) and longitudinal data from four studies (n = 48 646). Job strain and alcohol intake were self-reported. Job strain was analysed as a binary variable (strain vs. no strain). Alcohol intake was harmonised into the following categories: none, moderate (women: 1–14, men: 1–21 drinks/week), intermediate (women: 15–20, men: 22–27 drinks/week) and heavy (women: >20, men: >27 drinks/week). Cross-sectional associations were modelled using logistic regression and the results pooled in random effects meta-analyses. Longitudinal associations were examined using mixed effects logistic and modified Poisson regression. Compared to moderate drinkers, non-drinkers and (random effects odds ratio (OR): 1.10, 95% CI: 1.05, 1.14) and heavy drinkers (OR: 1.12, 95% CI: 1.00, 1.26) had higher odds of job strain. Intermediate drinkers, on the other hand, had lower odds of job strain (OR: 0.92, 95% CI: 0.86, 0.99). We found no clear evidence for longitudinal associations between job strain and alcohol intake.

Conclusions

Our findings suggest that compared to moderate drinkers, non-drinkers and heavy drinkers are more likely and intermediate drinkers less likely to report work-related stress.  相似文献   
157.
The main function of lysosomal proteins is to degrade cellular macromolecules. We purified a novel lysosomal protein to homogeneity from bovine kidneys. By gene annotation, this protein is defined as a bovine phospholipase B‐like protein 1 (bPLBD1) and, to better understand its biological function, we solved its structure at 1.9 Å resolution. We showed that bPLBD1 has uniform noncomplex‐type N‐glycosylation and that it localized to the lysosome. The first step in lysosomal protein transport, the initiation of mannose‐6‐phosphorylation by a N‐acetylglucosamine‐1‐phosphotransferase, requires recognition of at least two distinct lysines on the protein surface. We identified candidate lysines by analyzing the structural and sequentially conserved N‐glycosylation sites and lysines in bPLBD1 and in the homologous mouse PLBD2. Our model suggests that N408 is the primarily phosphorylated glycan, and K358 a key residue for N‐acetylglucosamine‐1‐phosphotransferase recognition. Two other lysines, K334 and K342, provide the required second site for N‐acetylglucosamine‐1‐phosphotransferase recognition. bPLBD1 is an N‐terminal nucleophile (Ntn) hydrolase. By comparison with other Ntn‐hydrolases, we conclude that the acyl moiety of PLBD1 substrate must be small to fit the putative binding pocket, whereas the space for the rest of the substrate is a large open cleft. Finally, as all the known substrates of Ntn‐hydrolases have amide bonds, we suggest that bPLBD1 may be an amidase or peptidase instead of lipase, explaining the difficulty in finding a good substrate for any members of the PLBD family. Proteins 2014; 82:300–311. © 2013 Wiley Periodicals, Inc.  相似文献   
158.
1. The activities of l-ornithine decarboxylase (EC 4.1.1.17) and S-adenosyl-l-methionine decarboxylase (EC 4.1.1.50) were dramatically enhanced in both the ventral prostate and the seminal vesicle of castrated rats in response to androgenic stimulation. The time course of the stimulation of ornithine decarboxylase together with the quantitatively different response of adenosylmethionine decarboxylase to testosterone treatment in the prostate gland and seminal vesicle indicated that the enhancement in polyamine synthesis in the ventral prostate may reflect both cellular proliferation and the restoration of the secretory functions of the organ. In the seminal vesicle, however, the stimulation of the polyamine-biosynthetic pathway more closely resembled the pattern found in other rat tissues, such as regenerating liver, undergoing compensatory growth. 2. Ornithine decarboxylase activity in the ventral prostate and especially in the seminal vesicle of sexually mature rat was diminished in vivo by various short-chain diamines such as 1,2-diaminoethane, 1,3-diaminopropane and putrescine (1,4-diaminobutane). These diamines had no direct effect on the enzyme activity in vitro. 3. In contrast with the marginal decrease in ornithine decarboxylase activity produced by diaminoethane in the ventral prostate of non-castrated animals, repeated injections of the latter amine completely prevented the intense stimulation of the enzyme activity in the ventral prostate and seminal vesicle of castrated rats at 24h after the commencement of testosterone treatment. 4. The decrease in ornithine decarboxylase activity observed after injections of diamines (putrescine) in the ventral prostate was apparently associated with a similar decrease in the amount of immunoreactive protein as revealed by immunotitration of the enzyme with antiserum to rat ornithine decarboxylase.  相似文献   
159.
160.
Summary Endo-1,4--glucanase and xylanase were produced by Trichoderma reesei immobilized on polyurethane foam using lactose as the main carbon source. The most porous carrier was found to be the best of those tested. The nitrogen source and KH2PO4 concentration of the production medium had a marked effect on culture pH during the course of fermentation and, consequently, on xylanase activity. An increase in lactose concentration from 7 to 27 g/l resulted in an increase in endoglucanase activity (max. 730 U/ml), xylanase activity (max. 3350 U/ml) and filter paper activity (max. 3.0 FPU/ml).  相似文献   
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