学困儿童和学优儿童的手书特点比较

取小学生55名,其中25名为学困生,30名为学优生,使用数码写字板测试二者在横线自然手书状态下的速度、加速度、压力、波动和断续5个指标的变化特点。研究结果表明,学困生横线手书的速度超过学优生,特别是中间速度,差异显著。学困生的加速度增长比较快,在短期内维持在高速状态,然后快速下降,学优生增长速度比较慢,但是在很长的时间内保持在高速状态,最后加速度的递减明显比学困生慢,差异显著。学困生的加速度曲线形态趋势类似于一个倒U形,而学优生的曲线形态类似于梯形。学困生和学优生的压力变化呈现开始递增、然后保持在较高的压力状态的态势,但是二者之间没有显著差异。二者的波动都出现于书写的开始阶段,但是波动次数没有显著差异。在书写过程,二者都没有出现断续。     

血液透析患者在线血流量与Kt／V及尿素清除率因果关系分析

通过测定维持性透析患者血管通路血流量、Kt/V及尿素清除率(URR),利用自然辨证法中因果关系的复杂性探讨血流量与透析充分性之间的因果关系。选择维持性血液透析患者80例。设定血液透析开始后在线血流量,根据血流量不同分为三组,I组血流量300ml/min,Ⅱ组血流量250ml/min,Ⅲ组血流量200ml/min,计算各组Kt/V值与尿素减少率,观察血流量与Kt/V及尿素减少率之间的相关关系。三组之间Kt/V、URR比较P<0.001,差异均具有显著性;血流量与Kt/V、URR之间呈正相关(r1=0.448,P<0.001;r2=0.413,P<0.001;)随着血流量从300ml/min降到200ml/min,Kt/V、URR分别从1.33±0.33、(68.19±8.86)%降到0.99±0.31、(58.59±13.19)%。血液透析患者的血流量与Kt/V、URR密切相关,两者之间存在因果关系,较高的在线血流量是保证透析充分性的一项重要指标。     

哈维启示录——纪念哈维发现血液循环390周年

哈维的杰出贡献是开创了血液循环理论。他通过思想观念的革新,对心脏和血液的性质、功能及运动规律提出了一套与传统观点不同的理论和框架,进而科学揭示了血液循环的奥秘。他在研究方法上堪称先驱:体现了“观察渗透理论”,更为注重运用数学方法进行推演论证,抓紧一切时间研究前人的相关著作,善于学习借鉴正确的哲学理念,深入思考血液在体内循环的机理,对于当时不具备观察条件的问题则借助想象提出假说。     

Flow at Work: Evidence for an Upward Spiral of Personal and Organizational Resources*

The present 2-wave study among 258 secondary school teachers investigates the relationship between personal and organizational resources on the one hand, and work-related flow on the other hand. On the basis of Hobfoll’s (1988) conservation of resources theory, Bandura’ social cognitive theory (1997; 2001), and Fredrickson’s (1998) “broaden-and-build” theory of positive emotions, we formulated two hypotheses: (1) personal resources (i.e., self-efficacy beliefs) and organizational resources (including social support climate and clear goals) facilitate work-related flow (work absorption, work enjoyment, and intrinsic work motivation); and (2) work-related flow has a positive influence on personal and organizational resources. The results of a series of structural equation modeling analyses offer clear support for both hypotheses. The theoretical and practical implications of these findings are discussed. *This research was supported by a grant from the Bancaixa Foundation (#11232.01/1) and the Spanish Ministry of Science & Technology (CICYT #SEC2000-1031).     

脑动静脉畸形手术前后血流灌注的TCD研究

对脑AVM患者手术前后进行TCD检查以及激光多普勒监测,以探讨脑AVM患者血流动力学指标与手术后局部脑皮层血流量指标变化的相关性,从而为预测正常灌注压突破综合征提供依据。结果显示AVM患者高流量组与低流量组之间手术后rCBF值存在显著差异(P0.05),并且不同流量AVM供血动脉的血流动力学指标差异性于手术后消失。因此,通过对AVM患者手术前后TCD监测,有助于为预测术后局部脑皮层血流量变化提供依据。     

定量组织速度成像评价酒精性心肌损害左室功能的价值

为了评估定量组织速度成像(QTVI)在评价大量饮酒后心肌损害左室功能改变方面的价值,我们对饮酒量符合酒精性心肌病诊断标准患者21例(B组,每日饮白酒≥150g或啤酒4瓶,每周6天~7天,10年以上),30例健康志愿者(A组,正常对照组)进行常规超声参数及QTVI参数测定,包括:二尖瓣环收缩期峰值速度(Vs)、舒张早期运动速度(Ve)、舒张晚期运动速度(Va)等。结果显示,B组常规各超声参数与A组比较差异有显著性统计学意义(P0.01)。QTVI参数与A组比较Va减低(P0.05),Vs、Ve、Ve/Va显著减低(P0.01)。提示QTVI技术能够有效地评估酒精性心肌损害病左室功能的改变。     

Internet-based contingency management to improve adherence with blood glucose testing recommendations for teens with type 1 diabetes

The current study used Internet-based contingency management (CM) to increase adherence with blood glucose testing to at least 4 times daily. Four teens diagnosed with Type 1 diabetes earned vouchers for submitting blood glucose testing videos over a Web site. Participants submitted a mean of 1.7 and 3.1 blood glucose tests per day during the 2 baseline conditions, respectively, compared to 5.7 tests per day during the intervention. Participants and their guardians rated the program favorably on a number of dimensions. The results suggest that Internet-based CM is feasible, acceptable, and effective to increase self-monitoring of blood glucose in teens.     

Detection and discrimination of optical flow components

Observers viewed animation sequences consisting of random dots, some of which moved coherently in a given direction (signal dots) and the rest of which moved randomly (noise dots). Using forced-choice procedures, detectability of weak signals within noise was measured for translation, rotation, and expansion/contraction. Sensitivity to all motion types was approximately equal, with practiced observers reliably detecting coherent motion at signal levels as low as 4%. Observers were able to identify the motion structure presented on a given trial at signal levels corresponding to the detection threshold, implying that the neural signals supporting detection are labeled for motion type. Results are discussed in the context of hierarchical analysis of optic flow in which all motion types are registered as patterns of activity among neurons comprising a single mechanism.     

Teamwork and flow proneness mitigate the negative effect of excess challenge on flow state

Flow theory postulates that flow experience is the most intense under high-challenge/high-skill conditions, whereas an excess of challenge is aversive. This study explores potential moderators that may offset the negative impact of overly high challenge on flow state. The literature suggests that a situational factor, teamwork, and a dispositional factor, flow proneness, may moderate the relationship between challenge and flow state. We tested these moderators with Hong Kong Chinese students whose optimal condition for experiencing flow was biased toward low-challenge/high-skill. A total of 128 participants played puzzles in three challenge levels both alone and in pairs. Although challenge level was negatively associated with flow state, dyadic (team) game (compared with solitary game) and flow proneness mitigated the negative relationship between challenge and flow state. These findings shed light on factors that promote enjoyment in challenging activities even among people in cultures that are prudent about challenges.