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Microfabricated fountain pens for high-density DNA arrays   总被引:1,自引:0,他引:1       下载免费PDF全文
We used photolithographic microfabrication techniques to create very small stainless steel fountain pens that were installed in place of conventional pens on a microarray spotter. Because of the small feature size produced by the microfabricated pens, we were able to print arrays with up to 25,000 spots/cm2, significantly higher than can be achieved by other deposition methods. This feature density is sufficiently large that a standard microscope slide can contain multiple replicates of every gene in a complex organism such as a mouse or human. We tested carryover during array printing with dye solution, labeled DNA, and hybridized DNA, and we found it to be indistinguishable from background. Hybridization also showed good sequence specificity to printed oligonucleotides. In addition to improved slide capacity, the microfabrication process offers the possibility of low-cost mass-produced pens and the flexibility to include novel pen features that cannot be machined with conventional techniques.  相似文献   

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There is a paucity of research into the importance of performing strength training exercises in postures specific to the movements they are attempting to facilitate. In addressing this question, 27 previously trained subjects were randomly allocated into heavy weight training and control groups. The weight training group performed 4–6 sets of 6–10 repetitions of the squat and bench press lifts twice a week for 8 weeks. Prior to and after the training period the following tests were conducted: bench press throw at 30% of maximal load, vertical jump, maximal squat and bench press lifts, push-up test performed over a force platform, 40-m sprint, 6-s cycle, and isokinetic tests assessing upper and lower body musculature in varying actions. The results supported the concept that posture is important in training as those exercises conducted in similar postures to the training recorded the greatest improvement in performance. For example, after completion of the training the weight training subjects significantly increased by approximately 12% the maximal load lifted in the bench press exercise and the peak torque in the isokinetic bench press test. However, performance in the isokinetic horizontal arm adduction test was not significantly changed. We speculate that the phenomenon of posture specificity may, at least in part, be caused by the differing postures altering the neural input to the musculature. The results stress the importance of selecting exercises in which the posture closely resembles that of the movements they are attempting to facilitate.  相似文献   

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It has been previously reported that carbohydrate (CHO) mouth rinse can improve exercise performance. The proposed mechanism involves increased activation of brain regions believed to be responsible for reward/motivation and motor control. Since strength-related performance is affected by central drive to the muscles, it seems reasonable to hypothesize that the positive CNS response to oral CHO sensing may counteract the inhibitory input from the muscle afferent pathways minimizing the drop in the central drive. The purpose of the current study was to test if CHO mouth rinse affects maximum strength and strength endurance performance. Twelve recreationally strength-trained healthy males (age 24.08 ± 2.99 years; height 178.09 ± 6.70 cm; weight 78.67 ± 8.17 kg) took part in the study. All of the tests were performed in the morning, after an 8 h overnight fasting. Subjects were submitted to a maximum strength test (1-RM) and a strength endurance test (six sets until failure at 70% of 1-RM), in separate days under three different experimental conditions (CHO mouth rinse, placebo—PLA mouth rinse and control—CON) in a randomized crossover design. The CHO mouth rinse (25 ml) occurred before every attempt in the 1-RM test, and before every set in the endurance strength test. Blood glucose and lactate were measured immediately before and 5 min post-tests. There were no significant differences in 1-RM between experimental conditions (CHO 101 ± 7.2 kg; PLA 101 ± 7.4 kg; CON 101 ± 7.2 kg; p = 0.98). Furthermore, there were no significance between trial differences in the number of repetitions performed in each set (p = 0.99) or the total exercise volume (number of repetitions × load lifted [kg]) (p = 0.98). A main effect for time (p < 0.0001) in blood lactate concentration was observed in both tests (1-RM and strength endurance). Blood glucose concentration did not differ between conditions. In conclusion, CHO mouth rinse does not affect maximum strength or strength endurance performance.  相似文献   

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Background

A suitable definition of primary care to capture the variety of prevailing international organisation and service-delivery models is lacking.

Aim

Evaluation of strength of primary care in Europe.

Design and setting

International comparative cross-sectional study performed in 2009–2010, involving 27 EU member states, plus Iceland, Norway, Switzerland, and Turkey.

Method

Outcome measures covered three dimensions of primary care structure: primary care governance, economic conditions of primary care, and primary care workforce development; and four dimensions of primary care service-delivery process: accessibility, comprehensiveness, continuity, and coordination of primary care. The primary care dimensions were operationalised by a total of 77 indicators for which data were collected in 31 countries. Data sources included national and international literature, governmental publications, statistical databases, and experts’ consultations.

Results

Countries with relatively strong primary care are Belgium, Denmark, Estonia, Finland, Lithuania, the Netherlands, Portugal, Slovenia, Spain, and the UK. Countries either have many primary care policies and regulations in place, combined with good financial coverage and resources, and adequate primary care workforce conditions, or have consistently only few of these primary care structures in place. There is no correlation between the access, continuity, coordination, and comprehensiveness of primary care of countries.

Conclusion

Variation is shown in the strength of primary care across Europe, indicating a discrepancy in the responsibility given to primary care in national and international policy initiatives and the needed investments in primary care to solve, for example, future shortages of workforce. Countries are consistent in their primary care focus on all important structure dimensions. Countries need to improve their primary care information infrastructure to facilitate primary care performance management.  相似文献   

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This study examined the role of high forces versus metabolic cost in the adaptations following strength training. Ten young, healthy male and female subjects trained one leg using concentric (CL) and the other using eccentric (EL) contractions of the quadriceps muscle for 20 weeks. EL used weights which were 35% higher than those used for CL. Isometric strength, and the length: tension and force: velocity relationship of the muscle were measured before and after training. Muscle cross-sectional area (CSA) was measured near the knee and hip using computed tomography. Increases in isometric strength were greater for CL compared to EL, the difference being significant with the knee at 1.57 rad (90°) [mean (SD), 43.7 (19.6)% vs 22.9 (9.8)%, respectively; P = 0.01]. Increases in isokinetic strength tended to be larger for EL, although the differences were not significant. Significant increases in CSA occurred near the hip for both EL and CL. These results suggest that metabolic cost, and not high forces alone, are involved in the stimuli for muscle hypertrophy and strength gains following high-resistance training.  相似文献   

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Although the Barron Ego Strength Scale (BESS) often has been shown to differentiate between the presence or absence of psychopathology, the exact construct measured as Ego Strength is little understood. This study related the BESS to the 15 personality needs of the Edwards Personal Preference Schedule, the Tolerance Scale of the California Psychological Inventory, and the Practical Outlook Scale of the Omnibus Personality Inventory. Ss were 80 normal adult women, recruited individually from the community. Results showed significant correlations (p <.05) only between Ego Strength and Abasement (-.44), Dominance (.19), Tolerance (.69), and Practical Outlook (-.32). This suggests that rather than distinguishing among specific personality profiles, the BESS relates to an underlying belief in self-adequacy, along with tolerant, balanced attitudes.  相似文献   

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The effects of strength training on sarcopenia.   总被引:2,自引:0,他引:2  
In the past decade strength training has been investigated extensively as a means of reversing the muscle mass loss that occurs with aging (sarcopenia). High intensity resistance training (HIRT) has led to increased protein synthesis, along with muscle hypertrophy measured at the whole body, whole muscle, and muscle fibre levels, in older adults. Typically, the strength increments associated with HIRT have been much larger than the hypertrophic response. However, most HIRT periods have been quite short. Less is known about the long-term hypertrophic response to HIRT in older adults. In order to lessen the effects of sarcopenia, HIRT should continue over the long term in older adults, to improve functional performance and health.  相似文献   

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Two studies were conducted in an attempt to replicate an earlier finding of self-esteem deficits in adolescent girls with early onset of insulin-dependent diabetes mellitus (IDDM). Participants in Study 1 were 139 adolescents with IDDM who completed the Perceived Competence Scale for Children (Harter, 1979). A 2 (gender) X 2 (group: age of IDDM onset: early vs. late) multivariate analysis of variance (MANOVA) did not reveal a significant interaction effect. Study 2 included 136 adolescents (104 adolescents with IDDM and 32 physically healthy adolescents) who completed the Self-Perception Profile for Children (Harter, 1985). A 2 (gender) X 3 (early IDDM onset, late IDDM onset, physically healthy control) MANCOVA, controlling for the effects of social class and adolescent age, also indicated no significant interaction effect. Thus, we found no differences in self-esteem based on age at disease onset and gender in two independent samples of youths with IDDM. In Study 2, significant gender and group effects were revealed, but when these findings are compared with normative data and data from our physically healthy sample, the results suggest that the youths with IDDM were functioning within the normal range on self-esteem. The importance of these findings in regard to the deficit versus adaptation models of chronic illness is discussed.  相似文献   

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Objective. Although increasing evidence shows the importance of habits in explaining health behaviour, many studies still rely solely on predictors that emphasize the role of conscious intentions. The present study was designed to test the importance of habit strength in explaining unhealthy snacking behaviour in a large representative community sample (N= 1,103). To test our hypothesis that habits are crucial when explaining unhealthy snacking behaviour, their role was compared to the 'Power of Food', a related construct that addresses sensitivity to food cues in the environment. Moreover, the relation between Power of Food and unhealthy snacking habits was assessed. Design and Methods. A prospective design was used to determine the impact of habits in relation to intention, Power of Food and a number of demographic variables. One month after filling out the questionnaire, including measures of habit strength and Power of Food, participants reported their unhealthy snacking behaviour by means of a 7-day snack diary. Results. Results showed that habit strength was the most important predictor, outperforming all other variables in explaining unhealthy snack intake. Conclusions. The findings demonstrate that snacking habits provide a unique contribution in explaining unhealthy snacking behaviour, stressing the importance of addressing habit strength in further research and interventions concerning unhealthy snacking behaviour. STATEMENT OF CONTRIBUTION: WHAT IS ALREADY KNOWN ON THIS SUBJECT?: Although increasing evidence shows the importance of habits in predicting a variety of behaviours (e.g., Aarts, Verplanken, & Van Knippenberg, 1998), including health behaviours (e.g., De Bruijn, 2010), with regard to unhealthy snacking behaviour, only one study demonstrated that habit strength is the most important predictor of unhealthy snacking behaviour (Verplanken, 2006). However, as this study was conducted among a student sample, the role of habits in unhealthy snacking behaviour has as of yet not been examined in a community sample. In addition, the role of habits has not yet been compared to the 'Power of Food', a related construct that addresses sensitivity to food cues in the environment. WHAT DOES THIS STUDY ADD?: The present study was the first to examine unhealthy snacking behaviour among a large representative community sample (N = 1103), showing that the importance of habits in unhealthy snacking behaviour can be extended to the general population. In addition, the present study included the intention to eat more healthily, habit strength and the Power of Food, and demonstrated that habit strength is the most important predictor of unhealthy snacking behaviour, stressing the importance of addressing habits in further research and interventions concerning unhealthy snacking behaviour.  相似文献   

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The diametral tensile strength (DTS) and compressive strength (CS) of a calcium phosphate cement comprised of tetracalcium phosphate and dicalcium phosphate anhydrous were studied. Cement powder and water were mixed at a powder/liquid ratio of 4.0. The resulting cement pastes were placed in molds and a pressure ranging from 0-2.8 MPa was applied for various lengths of time (0.5-24 h). DTS and CS measurements were conducted on 24-h wet samples. The strength was found to be significantly (p<0.05) affected by the pressure but not by the time. Samples prepared under a pressure of 0.7 MPa had a mean DTS value of 10.8+/-1.0 MPa (n = 5), which is comparable to the values reported in the literature for the same cement prepared under similar conditions. In contrast, the mean CS value obtained in the present study, 66.1+/-5.0 MPa (n = 5), was significantly higher than the value (51+/-4.5 MPa) previously reported. The higher CS may be attributed to an improved mold design that may reduce sample damage during demolding, and to the use of a loading device that applied a constant pressure to the sample during setting. The average standard deviation of the mean for the 19 DTS sample groups (n = 5 in each group) was 1.1 MPa, corresponding to 9.6% of the mean DTS value. The average standard deviation of the 7 CS sample groups (n = 5 in each group) was 4.5 MPa, corresponding to 7.1% of the mean CS value. Published 2000 John Wiley & Sons, Inc.  相似文献   

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人体寰椎横韧带拉伸性能的实验研究   总被引:4,自引:1,他引:4  
目的:研究人体寰椎横韧带的拉伸性能。方法:新鲜寰椎标本8例,制备成拉伸试件,进行定速率单向拉伸至横韧带断裂。结果:寰椎横韧带平均最大载荷为311.6N,最大变形量为6.0mm,刚度为72.9N/mm。结论:寰椎侧块间的分离超过6.0mm,就可存在横韧带断裂。  相似文献   

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Summary The central changes associated with a period of strength training have been investigated in a group of 32 young healthy volunteers. Subjects participated in one of three 12 week training programmes, which required different degrees of skill and coordination. Study 1 consisted of unilateral isometric training of the quadriceps with the contralateral leg acting as a control, the apparatus providing firm back support and a lap strap. In Study 2 training consisted of unilateral concentric leg-extension with back support and hand-grips. In Study 3 subjects performed bilateral leg-extension with no back support. Measurements of maximum voluntary isometric strength were made at 2–3 week intervals and a continual record was kept of the weights lifted in Studies 2 and 3. The largest increase in isometric force was seen for the trained leg in Study 1 (approximately 40%). There was no significant change in strength in the contralateral untrained leg. In Studies 2 and 3 there was a large increase in training weights (about 200%) associated with smaller increase in isometric force (15–20%). It is concluded that a large part of the improvement in the ability to lift weights was due to an increased ability to coordinate other muscle groups involved in the movement such as those used to stabilise the body. The importance of these findings for athletic training and rehabilitation is discussed.  相似文献   

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金属正畸托槽粘结强度的研究   总被引:1,自引:0,他引:1  
目的 体外评价金属网底托槽与牙面间的粘结强度,研究其影响因素。方法 以国内外两种金属网底托槽为研究对象,进行体外粘结强度测试,观察托槽底面结构状态,采用显微硬度测试技术进行硬度测试,采用能谱分析对托槽进行组成元素分析。结果 (1)两种托槽的体外粘结强度值相差较大;(2)样品底面结构有明显差异;(3)两样品硬度值基本接近;(4)两种托槽的组成元素及相对含量基本相同。结论 网底托槽的底面结构对其粘结强度有较大的影响。  相似文献   

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The effect of repeated muscular exertion on muscle strength   总被引:4,自引:0,他引:4  
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