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991.
Lee K Kim C Young Yang J Lee H Ahn B Xu L Yoon Kang J Oh KW 《Biomicrofluidics》2012,6(1):14114-141147
We propose a simple method for forming massive and uniform three-dimensional (3-D) cell spheroids in a multi-level structured microfluidic device by gravitational force. The concept of orienting the device vertically has allowed spheroid formation, long-term perfusion, and retrieval of the cultured spheroids by user-friendly standard pipetting. We have successfully formed, perfused, and retrieved uniform, size-controllable, well-conditioned spheroids of human embryonic kidney 293 cells (HEK 293) in the gravity-oriented microfluidic device. We expect the proposed method will be a useful tool to study in-vitro 3-D cell models for the proliferation, differentiation, and metabolism of embryoid bodies or tumours. 相似文献
992.
Currently, there is a lack of appropriate skill assessments available for use in golf. The aim of this study was to examine the discriminative validity and the test-retest reliability of the newly developed "Nine-Ball Skills Test". Participants of two ability levels (elite, n = 14; high-level amateur, n = 16) each hit nine golf shots of differing combinations of trajectory (straight, fade, draw) and height (normal, high, low) at an individually determined target area. Each shot was scored on its percent error index from the target and whether it achieved the maximum height as required. Participants completed the test twice using a 5-iron club. The elite group scored significantly higher (P < 0.05) than the amateur group for both the first and second rounds of the test as well as the combined scores. The between-round test-retest reliability was deemed to be not acceptable, thus we propose that the test's protocol should include use of the two rounds as standard. Due to the importance of ball striking and flight control to performance in golf, the Nine-Ball Skills Test is appropriate for providing a measure of this skill component in elite and high-level amateur golfers. 相似文献
993.
The purpose of this study was to compare changes in aerobic condition, strength, and muscular endurance following 8 weeks of endurance rowing alone or in combination with weight-training. Twenty-two elite rowers were assigned to (1) rowing (n = 10, 250-270 km · week?1) or (2) rowing (n = 12, 190-210 km · week?1) plus four weight-training sessions each week. Pre and post mean and standardized effect-size (ES) differences in aerobic condition (watts at 4 mmol · L?1) and strength (isometric pull, N), prone bench-pull (6-repetition maximum, 6-RM), 5- and 30-repetition leg-press and 60-repetition seated-arm-pull (J, performed on a dynamometer) normalized by body mass and log-transformed were analysed, after adjusting for gender. The standardized differences between groups were trivial for aerobic condition (ES [±90% CI] = 0.15; ±0.28, P = 0.37) and prone bench-pull (ES = 0.27; ±0.33, P = 0.18), although a moderate positive benefit in favour of rowing only was observed for the seated-arm-pull (ES = 0.42; ±0.4, P = 0.08). Only the weight-training group improved isometric pull (12.4 ± 8.9%, P < 0.01), 5-repetition (4.0 ± 5.7%, P < 0.01) and 30-repetition (2.4 ± 5.4%, P < 0.01) leg-press. In conclusion, while gains in aerobic condition and upper-body strength were comparable to extensive endurance rowing, weight-training led to moderately greater lower-body muscular-endurance and strength gains. 相似文献
994.
The aims of this study were to establish whether anthropometry, muscle strength and endurance accounted for differences between junior and senior elite rowing ergometer performance, and to determine annual development rates for juniors associated with training. Twenty-six junior (8 females, age 18.0 ± 0.3 years and 18 males, age 17.9 ± 0.2 years) and 30 senior (12 females, 23.7 ± 3.0 years and 18 males, 24.0 ± 3.9 years) heavyweight rowers, were assessed anthropometrically, performed a 2000-m ergometer time-trial, and completed various muscular strength and endurance tests. There were no anthropometrical differences between males; however after controlling for body-fat and standing-height, senior females were of greater body-mass (70.5 ± 4.6 kg and 77.2 ± 5.9 kg, P = 0.01) and sitting-height (89.8 ± 2.2 cm and 92.2 ± 6.1 cm, P = 0.04) than juniors. Moderate to very large standardised differences in all strength and endurance tests were observed between juniors and seniors (effect size (ES) range 0.9-1.9). Greater development rates (5.0% to 6.0%) and adjusted 2000-m performance was associated with upper-body strength (males) and endurance (females). In conclusion, after identification of desirable anthropometry, the 2000-m ergometer potential of juniors may be accounted for by upper-body strength and endurance. 相似文献
995.
996.
Shaul SHALVI Matthijs BAAS Michel J. J. HANDGRAAF Carsten K.W. DE DREU 《Learned Publishing》2010,23(2):117-123
At a top psychology journal, Psychological Science (PS), submissions peak during the summer months. We tested whether this seasonal submission bias decreases the likelihood of a paper being accepted in that period. Month of submission data was obtained for all 575 publications in PS for the period 2003–2006. Whereas submissions to PS were higher in the summer, there was no evidence that most accepted publications were originally submitted in the summer. Thus, contributors submit to PS when the likelihood of acceptance is the lowest – creating their own entrance barrier. A similar seasonal pattern was not identified for Personality and Social Psychology Bulletin, another top psychology journal. Using the Web of Knowledge database, we further assessed whether overcoming the seasonal entrance barrier influences the number of citations a paper receives in subsequent years. We discuss the possibility that the different rejections policies in the two journals, employing desk rejections or not, may explain this discrepancy, and explore a range of alternative hypotheses. 相似文献
997.
998.
Habib M Hussain I Fang WH Rajput ZI Yang ZZ Irshad H 《Journal of Zhejiang University. Science. B》2006,7(4):320-323
In this experiment conducted to study the inactivation dynamics of infectious bursal disease virus (IBDV) by binary ethylenimine (BEI) in comparison with formalin, IBDV was isolated from the bursa of infected chickens and its confirmation was done by agar gel precipitation test. Viral suspensions were subjected to inactivation with BEI and formalin for pre-set time in- tervals. BEI was employed at concentrations of 0.001 and 0.002 mol/L while formalin was used at 0.1% and 0.2%. Sampling was done at 6, 12, 24, 36 and 48 h of incubation and samples were tested for their inactivation status in 9-day-old embryonated eggs and 3-week-old broiler chickens. IBDV was completely inactivated by 0.001 and 0.002 mol/L BEI after 36 h of incubation at 37℃, whereas formalin at 0. 1% and 0.2% concentrations inactivated IBDV in 24 h. 相似文献
999.
A group of non-native, early signing deaf children between the ages of 7 and 11 years were tested on a referential communication task. A group of hearing children matched for sex and mental and chronological age were also included in the study. The aim was to study the deaf children's ability to take another persons perspective in a task that resembled a real-life communicative situation to a higher extent than the standard theory of mind (ToM) tasks. A further aim was to investigate the possible importance of a number of background variables such as mental and chronological age, working memory, and false-belief attribution. Results show that the hearing children outperformed the deaf children on the referential communication task and that results were highly correlated with both chronological and mental age, as well as with working memory. There was a positive, but not significant, correlation between false belief and success on the referential communication task. This is an indication that the two tasks tap different abilities and that false belief might be necessary, but not sufficient in order to be skilled in the art of referential communication. The possible role of working memory in the referential communication task is also discussed. The results support the hypothesis of the importance of early talk about mental states for the later development of ToM abilities. 相似文献
1000.
In this article, themost relevant literature on cognitive aging and instructional design is merged to formulate recommendations for designing computer-based training material aimed at elderly learners. The core message is that researchers and instructional designers do not need to develop special computerized instruction for older adults. Rather, existing principles of general instructional and multimedia design can be evaluated and used to accommodate the needs of elderly learners. Particular attention is given to John Sweller’s Cognitive Load Theory (CLT) and Richard Mayer’s Cognitive Theory of Multimedia Learning (CTML). It is argued that these instructional theories bear important benefits for older learners because they support an efficient use of available cognitive resources. New research directions are suggested to test the implications of these theories for learning in old age.
相似文献
Pascal W. M. Van GervenEmail: |