茶树中咖啡酰辅酶A氧甲基转移酶的基因克隆及其催化活性研究(英文)

目的:从茶树中克隆一种可以催化表没食子儿茶素没食子酸酯(EGCG)生成甲基化EGCG的酶——咖啡酰辅酶A氧甲基转移酶(CCo AOMT),实现甲基化EGCG的酶学合成,为甲基化EGCG的进一步开发利用提供理论依据和技术指导。创新点:本研究首次从茶树中克隆了一条CCo AOMT基因组序列;分析了CCo AOMT基因在不同茶树品种和不同成熟度茶鲜叶中的基因表达规律;证明了CCo AOMT具有催化合成甲基化EGCG的生物活性。方法:采用聚合酶链式反应(PCR)和序列分析获得CCo AOMT的编码序列和基因组序列;采用高效液相色谱-四级杆-飞行时间串联质谱技术(HPLC-QTOF-MS)分析酶促反应生成的甲基化EGCG产物(图4);采用实时荧光定量PCR分析CCo AOMT基因的表达差异(图5)。结论:本研究从茶树中克隆了CCo AOMT基因的编码序列(738 bp)和基因组序列(2678 bp),明确了该基因具有4个内含子和5个外显子;揭示了CCo AOMT可以催化EGCG生成EGCG4"Me、EGCG3"Me和EGCG3’Me等多种甲基化产物;证明了CCo AOMT具有催化生成甲基化EGCG的活性;并发现该基因的表达量高低与茶鲜叶的成熟度呈正相关关系。     

The impact of childhood foster care and other out-of-home placement on homeless women and their children

OBJECTIVE: This study compares homeless women who had childhood histories of foster care or other out-of-home placement to those who have not. METHOD: A countywide probability sample of homeless women (n = 179) received structured interviews. RESULTS: One-third of homeless women reported being raised apart from their parents. Among women with children under age 18, most (61.5%) had children who had lived in foster care or other out-of-home placements. Variables associated with homeless mothers' children living in foster care or other out-of-home placements were: Child was school-age, mother was age 35 or older, mother had a current alcohol or drug use disorder, mother experienced childhood sexual abuse, and mother ran away from home (when under age 18). CONCLUSIONS: Parenting is difficult for homeless mothers who may need to place their children with others to facilitate school attendance. Parent-child interaction may be problematic in family shelters where privacy is rare. Thus, programs promoting family preservation for homeless mothers should provide parenting support as well as permanent housing.     

Resident perceptions of anatomy education: a survey of medical school alumni from two different anatomy curricula and multiple medical specialties

In 2004, the University of Michigan Medical School reduced its gross anatomy curriculum. To determine the effect of this reduction on resident perceptions of their clinical preparedness, we surveyed alumni that included residents from the original and new shortened curricula. A Likert-scale survey was sent to four classes of alumni. Respondents were compared in old curriculum (OC) and new curriculum (NC) groups, surgical specialty (SS) and nonsurgical specialty (NS) groups, and subgroups of SS and NS were compared for differences between OC and NC. Mean response scores were compared using independent samples T-tests. As a single population (n = 110), respondents felt their anatomy education prepared them well for residency, that a more robust anatomy curriculum would be helpful, that dissection was important to their residency preparation, and that a 4th year anatomy elective was effective in expanding their anatomy education and preparing them for residency. No significant difference existed between OC and NC groups, neither as a whole nor as SS and NS subgroups. The SS group felt dissection was more important to their residency preparation than the NS group (P = 0.001) and that a more robust anatomy curriculum would have better prepared them for residency (P = 0.001). Thirty percent of SS respondents who did not take a 4th year elective commented that they wish they had. Fourth year anatomy electives were highly valued by residents, and respondents felt that they should be offered to students as a way of revisiting anatomy following the 1st year of clinical training.     

Subject-specific computer simulation model for determining elbow loading in one-handed tennis backhand groundstrokes

A subject-specific angle-driven computer model of a tennis player, combined with a forward dynamics, equipment-specific computer model of tennis ball-racket impacts, was developed to determine the effect of ball-racket impacts on loading at the elbow for one-handed backhand groundstrokes. Matching subject-specific computer simulations of a typical topspin/slice one-handed backhand groundstroke performed by an elite tennis player were done with root mean square differences between performance and matching simulations of < 0.5 degrees over a 50 ms period starting from ball impact. Simulation results suggest that for similar ball-racket impact conditions, the difference in elbow loading for a topspin and slice one-handed backhand groundstroke is relatively small. In this study, the relatively small differences in elbow loading may be due to comparable angle-time histories at the wrist and elbow joints with the major kinematic differences occurring at the shoulder. Using a subject-specific angle-driven computer model combined with a forward dynamics, equipment-specific computer model of tennis ball-racket impacts allows peak internal loading, net impulse, and shock due to ball-racket impact to be calculated which would not otherwise be possible without impractical invasive techniques. This study provides a basis for further investigation of the factors that may increase elbow loading during tennis strokes.     

Superconductivity in One-atomic-layer Metal Films

Superconductivity is a peculiar quantum phenomenon which originates from the pairing of conduction electrons, followed by phase coherent condensation. Since the discovery by K. Onnes in 1911, superconductivity has been one of the hottest topics in physics for an entire century, and still attracts people’s great interest. One of the intriguing issues is how     

Internal and external focus of attention in a novice form sport

In the current experiment, we examined optimal focus for novices during a movement sequence in which performance was measured on accurate movement form/technique. A novel gymnastics routine was practiced under either an internal skill-relevant, internal skill-irrelevant, external, or no attention focus. Retention and transfer tests were then completed. During acquisition, adopting an internal irrelevant focus significantly improved performance, whereas an external focus degraded performance. There were no significant group differences in the retention and transfer tests. This suggests that learning of movement form/technique did not benefit from a specific focus of attention. The results are interpreted via an attentional capacity viewpoint and the notion that form tasks do not always contain obvious movement effects central to common coding and the constrained action hypothesis.     

Coaching competency and satisfaction with the coach: a multi-level structural equation model

The purpose of this initial predictive validity study was to determine the ability of measures derived from the Athletes' Perceptions of Coaching Competency Scale II?-?High School Teams (APCCS II-HST) to predict satisfaction with the head coach. Specification of the statistical model was informed by the mediational model of coach-athlete interactions. The technical quality of the satisfaction measure was evaluated before testing the predictive validity of the coaching competency measures. Data were collected from athletes of seven sports. Athlete observations (N?=?748) were clustered within teams (G?=?74). Multi-group confirmatory factor analyses (CFA) provided evidence for factorial invariance of a reduced version of the satisfaction measure by athlete gender. Multi-level CFA provided evidence of model-data consistency for a reduced version of the satisfaction measure. Multi-level structural equation modelling provided evidence for the ability of latent coaching competency to positively predict latent satisfaction at both the athlete level (technique competency and motivation competency) and the team level (coaching competency) and for close model-data fit. Implications of this study include: that the APCCS II-HST should be viewed as a replacement for the Coaching Competency Scale when the intended population is appropriate; a preliminary multi-level measurement model for satisfaction with one's coach that should be considered as a potential starting point in subsequent studies; and empirical support for a key relationship proposed in the mediational model of coach-athlete interactions.     

Aroma changes of black tea prepared from methyl jasmonate treated tea plants

研究目的：为茉莉酸甲酯诱导来提高茶叶香气品质提供理论依据,为新型花香红茶的研制提供技术支持。创新要点：首次将茉莉酸甲酯应用于诱导茶叶香气品质提高,初步验证了茶叶香气品质提高的本质原因：相关酶活性提高,基因表达上调。研究方法：采用顶空固相微萃取法（HS-SPME）对红茶香气进行富集,气相色谱-质谱联用仪（GC-MS）进行解吸附分析,实时定量多聚酶链式反应（qRT-PCR）分析茶鲜叶中香气相关酶基因表达。重要结论：茉莉酸甲酯诱导后的茶鲜叶中多酚氧化酶（PPO）活性上升,β-葡萄糖苷酶活性下降;PPO和β-樱草糖苷酶基因表达上调,β-葡萄糖苷酶基因表达下调。茉莉酸甲酯诱导后的茶鲜叶能明显提高由其制成的红茶香气品质,且萜烯醇类和萜烯类含量明显提高。