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1.
This paper proposes a new “twisted” 3D microfluidic mixer fabricated by a laser writing/microfabrication technique. Effective and efficient mixing using the twisted micromixers can be obtained by combining two general chaotic mixing mechanisms: splitting/recombining and chaotic advection. The lamination of mixer units provides the splitting and recombination mechanism when the quadrant of circles is arranged in a two-layered serial arrangement of mixing units. The overall 3D path of the microchannel introduces the advection. An experimental investigation using chemical solutions revealed that these novel 3D passive microfluidic mixers were stable and could be operated at a wide range of flow rates. This micromixer finds application in the manipulation of tiny volumes of liquids that are crucial in diagnostics. The mixing performance was evaluated by dye visualization, and using a pH test that determined the chemical reaction of the solutions. A comparison of the tornado-mixer with this twisted micromixer was made to evaluate the efficiency of mixing. The efficiency of mixing was calculated within the channel by acquiring intensities using ImageJ software. Results suggested that efficient mixing can be obtained when more than 3 units were consecutively placed. The geometry of the device, which has a length of 30 mm, enables the device to be integrated with micro total analysis systems and other lab-on-chip devices.  相似文献   
2.
Research in Higher Education - Computing career opportunities are increasing across all sectors of the U.S. economy, yet there remains a serious shortage of college graduates to fill these jobs....  相似文献   
3.
This study examined the kinetic and temporal differences between countermovement jumps (CMJs) and eccentrically loaded CMJs. A survey of 109 coaches and athlete showed that 87% of respondents regularly used jumps with added mass within training. Sixteen male and thirteen female track and field athletes from sprinting, hurdling and jumping events performed 5 bodyweight CMJs 5 jumps wearing a weighted jacket and 5 eccentrically loaded dumbbell (LDB) jumps trials in a randomised order. Peak force (PF), peak power (PP), flight time (FT), concentric time (CON-T), eccentric time (ECT), total time (TIME) and eccentric/concentric ratio (E/C-Ratio) were obtained from force plate data. Statistically significant differences (p < 0.05) with moderate to large magnitude effect sizes were found between men and women in FT, PP and PF but not in any of the temporal variables. The results indicated that the WJ decreased FT in men (↓9%) and women (↓10%) but LDB jumps had similar FT to CMJ. Overall, the results showed that LDB increased the E/C Ratio (↑50% and ↑42%) and decreased CON-T (↓37% and ↓25%) compared with WJ and CMJ respectively. LDB jumping is not recommended as a training modality as it tends to disrupt the relative timing of the jump action.  相似文献   
4.
Type 2 diabetes mellitus (DM) is a multifactorial disease where both genetic and environmental factors contribute to its pathogenesis. Estrogen plays an important role in type 2 DM pathogenesis. A number of polymorphisms have been reported in the estrogen receptor (ESR1), including the XbaI and PvuII restriction enzyme polymorphisms of ESR1,which may be involved in disease pathogenesis. Metallothioneins (MT) act as potent antioxidants against various oxidative damages. Very few studies have indicated the association between Estrogen Receptor-α, MT1 gene polymorphisms with type2 DM. A total of 100 type 2 diabetic women and 100 age, sex matched controls were recruited. Using the PCR based RFLP method, the PvuII and XbaI polymorphisms of ESR1 and in MT1A (rs8052394 and rs11076161) gene polymorphisms were analysed. The genotype distribution and frequency of mutated allele showed no significant differences between diabetic and non-diabetic groups in PvuII (χ2 = 2.443; P = 0.1181) or XbaI (χ2 = 1.789; P = 0.1812) and rs8052394 (χ2 = 1.154; P = 0.2840) or rs11076161 (χ2 = 0.4141; P = 0.5199), polymorphisms. This is the first Indian study to conclude that ESR1 and MT1 gene polymorphisms are not associated with increased susceptibility to type 2 diabetes in Indian women.  相似文献   
5.
Noting that interactivity is often defined but seldom theorized in the literature, this article provides some pointers for developing theories about effects of interactivity, particularly as it applies to Web-based mass communication. It first makes the case that interactivity is an attribute of the technology and not that of the user. It exposes the tautology of studying the effects of perceived interactivity and calls for the consideration of ontological aspects that constitute interactivity while specifying its social and psychological effects. Theoretical explorations may be categorized in terms of three classes of outcome measures—behavioral, attitudinal, and cognitive—as we investigate the role played by interactivity in initiating action, changing attitudes, and altering the nature of information processing. These would result in theories about technology rather than psychology in that they help us specify direct and combination effects of interactivity, modality, navigability, and other technological attributes of the Web medium.  相似文献   
6.
Hypertension causes complications such as coronary atherosclerosis and thrombosis wherein inflammatory factors play significant role. In the present study inflammatory molecules such as cell adhesion molecules (CAMs); endothelial (E)-selectin, platelet (P)-selectin, intercellular CAM-1 (ICAM-1), vascular CAM-1 (VCAM-1) and platelet endothelial CAM-1 (PECAM-1) were analysed in subjects newly diagnosed with hypertension with no secondary cause against normotensive healthy individuals. In each group 57 subjects were recruited and soluble (s) levels of CAMs were analysed by ELISA. As compared to controls median of sE-selectin (49.2%, P=0.001), sP-selectin (54.3%, P=0.001), and sICAM-1 (18.9%, P=0.012) were significantly elevated in hypertensive subjects. Significant negative correlation was observed of sP-selectin (spearman rank correlation coefficient (rs) =−0.345, p=0.027) and sPECAM-1 (rs =−0.446, p=0.003) with age in hypertension group. Hypertension may increase expression of certain CAMs while younger hypertensives in addition are also at increased risk of atherothrombosis.  相似文献   
7.
Ocimum sanctum Linn. (also known as Tulsi) is a sacred Indian plant, the beneficial role of which, in obesity and diabetes is described traditionally. This is a randomized, parallel group, open label pilot study to investigate the effect of O. sanctum on metabolic and biochemical parameters in thirty overweight/obese subjects, divided into two groups A and B. Group A (n = 16) received one 250 mg capsule of Tulsi (O. sanctum) extract twice daily in empty stomach for 8 weeks and group B (n = 14) received no intervention. Statistically significant improvements in the values of serum triglycerides (p = 0.019); low density lipoprotein (p = 0.001); high density lipoprotein (p = 0.001); very low density lipoprotein (p = 0.019); Body Mass Index, BMI (p = 0.005); plasma insulin (p = 0.021) and insulin resistance (p = 0.049) were observed after 8 weeks in the O. sanctum intervention group. The improvement in HDL-C in the intervention group when compared to the control group was also statistically significant (p = 0.037). There was no significant alteration of the liver enzymes SGOT and SGPT in both the intervention (p = 0.141; p = 0.074) and control arms (p = 0.102; p = 0.055) respectively. These observations clearly indicate the beneficial effects of O. sanctum on various biochemical parameters in young overweight/obese subjects.  相似文献   
8.
‘Professional Ethics’ has been offered as a compulsory course to undergraduate engineering students in a premier engineering institution of India. It was noticed that students’ perceptions and attitudes were frivolous and ornamental towards this course. Course instructors and institution authorities were motivated to find out the factors contributing to this awkwardness. For this purpose, a questionnaire was prepared and administrated to 336 students registered for the July–November 2014 semester. The study found two factors contributing to students’ indifference towards the Professional Ethics course. First, most of the students did not have self-interest to join the engineering programme, and while pursuing their study, they decided to switch to a different field upon completion of their engineering study. Second, students who desired to be engineers in their future believed that engineering code of ethics is not really referred to in most of the engineering jobs, and therefore Professional Ethics course is only meant for classroom discussions.  相似文献   
9.
Vascular endothelial growth factor (VEGF) plays an important role in the development of Breast Cancer. The aim of this study was to investigate the association of polymorphisms in the VEGF gene on prognosis of Breast Cancer patients. This study comprised 200 patients with histologically confirmed cases of Breast cancer and 200 controls. Genotyping of the VEGF gene polymorphisms at +405G>C,−1154G>A, were performed by PCR-RFLP analysis. Preoperative plasma VEGF levels were determined by ELISA. Amongst both cases and controls, the genotypic distribution of the individual SNPs were all in Hardy–Weinberg equilibrium. Mean VEGF level was significantly elevated in cases compared to controls (t = 8.248; P < 0.001). No significant association was found between +405G>C,−1154G>A VEGF polymorphism and Breast Cancer. Logistic regression analysis revealed that 405GG & 1154GG were associated with higher levels of VEGF.  相似文献   
10.
Spherical and non-spherical wax microparticles are generated by employing a facile two-step droplet microfluidic process which consists of the formation of molten wax microdroplets in a flow-focusing microchannel and their subsequent off-chip crystallization and deformation via microdroplet impingement on an immiscible liquid interface. Key parameters on the formation of molten wax microdroplets in a microfluidic channel are the viscosity of the molten wax and the interfacial tension between the dispersed and continuous fluids. A cursory phase diagram of wax morphology transition is depicted depending on the Capillary number and the Stefan number during the impact process. A combination of numerical simulation and analytical modeling is carried out to understand the physics underlying the deformation and crystallization process of the molten wax. The deformation of wax microdroplets is dominated by the viscous and thermal effects rather than the gravitational and buoyancy effects. Non-isothermal crystallization kinetics of the wax illustrates the time dependent thermal effects on the droplet deformation and crystallization. The work presented here will benefit those interested in the design and production criteria of soft non-spherical particles (i.e., alginate gels, wax, and polymer particles) with the aid of time and temperature mediated solidification and off-chip crosslinking.  相似文献   
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