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1.
V Nathanson 《Canadian Metallurgical Quarterly》1998,316(7137):1082-1086
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Epinephrine increased outflow facility and cyclic AMP in the in vitro perfused human anterior segment with a maximal facility increase of 44% occurring at approximately 2 x 10(-5) M. Cyclic AMP measured in the perfusate from anterior segments increased by 12-14 fold after administration of 10(-5) M epinephrine. Both the facility increase and cyclic AMP rise were blocked by the beta-2 selective antagonist, ICI118,551. While there was a correlation between the facility increase and elevation in cyclic AMP levels, the rise in cyclic AMP preceded the facility increase by about 1 hour, suggesting that the ultimate effect of epinephrine involved a rather slow event such as synthesis and release of prostaglandins or protein synthesis. Subsequent perfusion studies showed that very large concentrations of indomethacin were necessary to block the outflow facility effect of epinephrine, suggesting that prostaglandin synthesis did not underlie the facility effect in this system. However, 5 x 10(-5) M cyclohexamide blocked the effect on outflow facility of both epinephrine and forskolin, but did not block the rise in cyclic AMP. These studies suggest that protein synthesis may play a role in the epinephrine-induced facility increase at some point beyond the second messenger level. 相似文献
4.
We present an efficient method for learning part-based object class models from unsegmented images represented as sets of
salient features. A model includes parts’ appearance, as well as location and scale relations between parts. The object class
is generatively modeled using a simple Bayesian network with a central hidden node containing location and scale information,
and nodes describing object parts. The model’s parameters, however, are optimized to reduce a loss function of the training
error, as in discriminative methods. We show how boosting techniques can be extended to optimize the relational model proposed,
with complexity linear in the number of parts and the number of features per image. This efficiency allows our method to learn
relational models with many parts and features. The method has an advantage over purely generative and purely discriminative
approaches for learning from sets of salient features, since generative method often use a small number of parts and features,
while discriminative methods tend to ignore geometrical relations between parts. Experimental results are described, using
some bench-mark data sets and three sets of newly collected data, showing the relative merits of our method in recognition
and localization tasks. 相似文献
5.
P Gennis L Miller EJ Gallagher J Giglio W Carter N Nathanson 《Canadian Metallurgical Quarterly》1996,3(6):568-573
Thirty-five male patients, aged 34-79 yr, with definite rheumatoid arthritis (RA) were recruited from out-patient clinics and randomized to receive monthly injections of testosterone enanthate 250 mg or placebo as an adjunct therapy for 9 months. Endpoints included disease activity parameters and bone mineral density (BMD). At baseline, there were negative correlations between the ESR and serum testosterone (r = -0.42, P < 0.01) and BMD (hip, r = -0.65, P < 0.01). A total of 29.6% of all patients had at least one vertebral fracture, most having multiple fractures. Back pain, however, was not more prevalent in fracture patients (55% vs 50%). Disease activity was significantly higher in the fracture group (joint score P < 0.05, rheumatoid factor P < 0.01). Thirty patients completed the trial, 15 receiving testosterone and 15 receiving placebo. There were significant rises in serum testosterone, dihydrotestosterone and oestradiol in the treatment group. There was no significant effect of treatment on disease activity overall, five patients receiving testosterone underwent a "flare'. Differences in mean BMD following testosterone or placebo were non-significant (spine: +1.2% vs -1.1%; femur: -0.3% vs +0.3%). There was no suggestion of a positive effect of testosterone on disease activity in men with RA. 相似文献
6.
Nitsa Ne'eman Daphna Marbach Limor Chen-Konak Keren Kaufman-Francis Merav Berkovich Shulamit Levenberg Noah Lotan Sarit Sivan 《Israel journal of chemistry》2013,53(9-10):821-828
Biodegradable constructs, providing both mechanical support to growing tissues and timed release of biological agents, are highly desired in tissue engineering. This study aimed to develop a platform technology that responds to these challenges. Accordingly, we report herein on model systems in which microspheres of poly(suberic anhydride), containing all-trans retinoic acid (atRA), and poly(d,l -lactic acid-co-glycolic acid), containing bovine serum albumin (BSA), were co-sintered at room temperature, using a solvent/nonsolvent mixture. These scaffolds release about 60% of atRA and negligible amounts of BSA within the first five days, followed by slower and steady release of BSA. They have pores of 150–500 μm and a compressive modulus of 200 kPa. Myoblasts and fibroblasts were seeded on the loaded scaffolds and both showed enhanced proliferation rates. Based on sound thermodynamic principles of polymer science, this technology demonstrates an as yet unachieved degree of versatility. It allows for the tailoring of “intelligent” scaffolds that preserve the integrity of the incorporated agents and of advanced modalities to release various drugs in a scheduled manner. 相似文献
7.
Amy I. Nathanson Molly L. Sharp Fashina Aladé Eric E. Rasmussen Katheryn Christy 《The Journal of communication》2013,63(6):1088-1108
This study explored the relation between preschoolers' television exposure and one important indicator of cognitive processing called theory of mind (ToM). A total of 107 preschoolers and their parents provided data on the preschoolers' television exposure (including both intentional viewing and exposure via background television), parent–child discussion of television, and preschoolers' ToM. The results indicated that preschoolers who were exposed to more background television and who had a television in their bedroom performed more poorly on ToM assessments compared with other children. Parent–child discussion of television was positively related to ToM performance, however. These results have implications for how we understand the effects of television on preschoolers. 相似文献
8.
OBJECTIVE: Prospectively evaluate the effect on the nutritional status of a glucose polymer as energy supplementation alone in chronic hemodialysis patients with moderate and severe malnutrition. MATERIAL AND METHODS: The nutritional status of 55 hemodialysis patients was assessed by using a score that included Iron binding capacity, albumin, cholesterol, body mass index, mid brachial circumference, arm muscle area, triceps skinfold, and clinical impression. Twenty-two of 27 patients (14 men and 8 women, mean age 43 +/- 15 years, time on dialysis 65 +/- 49 months) were classified as moderately or severely malnourished and were supplemented for 6 months with 100 g of glucose polymers per day (equivalent to 380 kcal or 1590 kJ) added to the usual food intake. The patients were reevaluated at 3 and 6 months. RESULTS: Only body weight, body mass index, triceps skinfold, and brachial circumference and clinical impression increased significantly at the end of the third month (P < .05) in the 22 patients. These results were confirmed at 6 months in 18 patients that completed the study. Mean body weight increase was 2.4 kg (range, .2 to 6.3 kg). The nutritional status, evaluated through the score, improved in only 4 patients at the end of the study. Few gastrointestinal side effects were observed. Triglycerides increased from 136 +/- 40 mg/dL to 235 +/- 120 mg/dL. Follow-up of the patients showed that fat mass (assessed by anthropometry) was maintained for 6 months after supplementation was discontinued. CONCLUSION: Energy supplementation alone in patients with moderate and severe malnutrition on chronic hemodialysis resulted in an increase in body weight, owing to an increase in body fat, but the nutritional status did not improve. 相似文献
9.
Implications of cultural accommodation–hybridization were explored within the framework of individualism–collectivism. Individualism highlights the personal and centralizes individuals as the unit of analyses, whereas collectivism highlights the social and contextualizes individuals as parts of connected social units. In 2 experiments, the ways in which individualism, collectivism, and identity salience influence social obligation to diverse others was explored. The authors varied the personal goal interrupted (achievement–pleasure), the target (individual–group), and focus (in-group–larger society) of social obligation within subjects. The authors hypothesized that collectivism would increase obligation to the in-group when identity was made salient; that individualism alone would dampen social obligation; and that cultural accommodation–hybridization (being high in both individualism and collectivism) would increase obligation to larger society. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
10.
The large retarding field in an exponentially retrograded photodiode is shown to significantly reduce the base-generated photocurrent at low reverse-bias voltages. Increasing the reverse voltage on the diode reduces the length over which this retarding field is effective, thereby increasing the Photo-Transmission Coefficient of the diode. From avalanche breakdown considerations, the largest ratio of change in photocurrent caused by this effect is shown to be only a function of the resistivity and bulk-lifetime in the base of the diode. This voltage-controlled collection effect is observable only in diodes with high background resistivity (i.e. silicon > 25 Ω cm.). It is theoretically possible to obtain voltage-controlled collection ratios of better than 50:1 in, typically, a 10 V junction swing.
Experimental results compare well with theoretical models. 相似文献