Shrink-film microfluidic education modules: Complete devices within minutes

As advances in microfluidics continue to make contributions to diagnostics and life sciences, broader awareness of this expanding field becomes necessary. By leveraging low-cost microfabrication techniques that require no capital equipment or infrastructure, simple, accessible, and effective educational modules can be made available for a broad range of educational needs from middle school demonstrations to college laboratory classes. These modules demonstrate key microfluidic concepts such as diffusion and separation as well as "laboratory on-chip" applications including chemical reactions and biological assays. These modules are intended to provide an interdisciplinary hands-on experience, including chip design, fabrication of functional devices, and experiments at the microscale. Consequently, students will be able to conceptualize physics at small scales, gain experience in computer-aided design and microfabrication, and perform experiments-all in the context of addressing real-world challenges by making their own lab-on-chip devices.     

新生代员工核心自我评价与工作投入的关系:有调节的中介模型

采用核心自我评价量表、工作投入量表、心理授权量表和不匹配感知量表对16家企业447名新生代员工进行调查,通过层级回归分析新生代员工核心自我评价与工作投入的关系,以及考察心理授权与过度教育在此关系中发挥的作用。结果表明:(1)新生代员工核心自我评价对工作投入有显著正向影响;(2)心理授权在核心自我评价和工作投入关系中有着部分中介效应;(3)过度教育对心理授权中介效应的调节作用成立,对过度教育的高感知不仅削弱了核心自我评价与心理授权的正向关系,也进而弱化了心理授权对工作投入的积极作用。     

Serum total PSA and free PSA in breast tumors

Now a days measurement of molecular forms of PSA has gained importance in clinical practice. Several studies have demonstrated the production of PSA in female tissues, such as breast. The present piece of work has been undertaken with an objective to estimate the relative proportion of the molecular forms of PSA in serum along with serum testosterone in benign and malignant breast tumor cases and to analyze their association with the severity of the disease process 34 malignant and 26 benign breast disease cases along with 33 healthy controls of same age group were enrolled in this study for evaluation. Serum testosterone was measured by ELISA, whereas serum total PSA (TPSA) and free PSA (FPSA) were estimated by electrochemiluminescence immunoassay. A significant rise of fasting plasma glucose along with prominent dyslipidemia was observed in breast tumor cases. Marked rise in serum testosterone as well as TPSA and FPSA was documented in both benign and malignant breast tumor cases. Serum testosterone revealed a significant positive association with both TPSA and FPSA pointing towards an etiological association between them. However, surgical removal of tumor mass resulted in a marked decline of presurgical value of both TPSA and FPSA with a non-significant fall in serum testosterone revealing tumor tissue as the source of FPSA and TPSA. Thus, estimation of PSA provides prognostic information that may assist in future treatment.     

改良大脑真的好吗?

人类有能力测定和操纵基因,这一革命激起了各种各样的伦理争议.同样具有深远意义的脑科学革命,引起的注意却少得让人吃惊.     

The influence of exercise intensity on frontal electroencephalographic asymmetry and self-reported affect

The "feel better" effect of exercise has been well established, but the optimal intensity needed to elicit a positive affective response is controversial. In addition, the mechanisms underlying such a response are unclear To clarify these issues, female undergraduate students were monitored for electroencephalographic (EEG) and self-reported affective responses during the recovery period following rest, low, moderate, and high intensities of treadmill running, each lasting 30 min. Frontal EEG asymmetry and self-reported vigor scores following exercise at all three intensities were significantly elevated compared to those observed following rest. The results suggest that steady-state aerobic exercise bouts executed at varying intensities induce a similar affective response during the recovery period when assessed at both the behavioral and psychophysiological levels.     

地球有幾歲了

我們的行星存在已有多少年呢?甚麽時候在地面構成了山嶽和海洋呢?這些問题從古以來就引起科學家的興趣,但是就是今天的科學,也不能作出完全正確的答案,這是不足怪的,因為它們是非常複雜的問題。怎樣來確定地球的年齡呢?最早,人們企圖利用沉積物在海洋底沉積的速度來計算,後來又試圖用溶融液態的地球冷却到現在狀態所需要的時間來测定。不同的方法就得到不同的結果:由八千萬到十萬萬年。當時的人們還没有考     

Effects of muscle-tendon length on joint moment and power during sprint starts

The aim of this study was to examine the effects of muscle-tendon length on joint moment and power during maximal sprint starts. Nine male sprinters performed maximal sprint starts from the blocks that were adjusted either to 40 degrees or 65 degrees to the horizontal. Ground reaction forces were recorded at 833 Hz using a force platform and kinematic data were recorded at 200 Hz with a film camera. Joint moments and powers were analysed using kinematic and kinetic data. Muscle - tendon lengths of the medial gastrocnemius, soleus, vastus medialis, rectus femoris and biceps femoris were calculated from the set position to the end of the first single leg contact. The results indicated that block velocity (the horizontal velocity of centre of mass at the end of the block phase) was greater (P < 0.01) in the 40 degrees than in the 65 degrees block angle condition (3.39 +/- 0.23 vs. 3.30 +/- 0.21 m . s(-1)). Similarly, the initial lengths of the gastrocnemius and soleus of the front leg in the block at the beginning of force production until half way through the block phase were longer (P < 0.001) in the 40 degrees than in the 65 degrees block angle condition. The initial length and the length in the middle of the block phase were also longer in the 40 degrees than in the 65 degrees block angle condition both for both the gastrocnemius (P < 0.01) and soleus (P < 0.01-0.05) of the rear leg. In contrast, the initial lengths of the rectus femoris and vastus medialis of the front leg were longer (P < 0.05) in the 65 degrees than in the 40 degrees block angle condition. All differences gradually disappeared during the later block phase. The peak ankle joint moment (P < 0.01) and power (P < 0.05) during the block phase were greater in the 40 degrees than in the 65 degrees block angle condition for the rear leg. The peak ankle joint moment during the block phase was greater (P < 0.05) in the 40 degrees block angle for the front leg, whereas the peak knee joint moment of the rear leg was greater (P < 0.01) in the 65 degrees block angle condition. The results suggest that the longer initial muscle-tendon lengths of the gastrocnemius and soleus in the block phase at the beginning of force production contribute to the greater peak ankle joint moment and power and consequently the greater block velocity during the sprint start.     

善有善报,恶有恶报

<正>一个女人为家人烤面包并额外拿出一个送给饥饿的路人。她把额外的面包放在窗台上,无论谁都可以拿走。每天当女人向窗台上放面包时,她总是为她出远门寻找财富的儿子做一次祈祷。多少个月了,她一直没有他的消息。她祈祷他平安回家。每天都有一个驼背的人来把面包拿走,