45 research outputs found

    Interactive flow behaviour and heat transfer enhancement in a microchannel with cross flow synthetic jet

    Get PDF
    This paper examines the effectiveness in combining a pulsating fluid jet for thermal enhancement in microchannel heat sinks. The proposed arrangement utilises an oscillating diaphragm to induce a high-frequency periodic fluid jet with zero net mass output at the jet orifice hence, termed "synthetic jet". The pulsed jet interacts with the fluid flow through microchannel passages altering their flow characteristics. The present study develops a 2-dimensional finite volume numerical simulation based on unsteady Reynolds-averaged Navier-Stokes equations for examining the microchannel-synthetic jet flow interaction. For a range of parametric conditions, the behaviour of this periodic flow with its special features is identified and the associated convective heat transfer rates are predicted. The results indicate that the pulsating jet leads to outstanding thermal performance in microchannel flow increasing its heat dissipation rate by about 4.3 times compared to a microchannel without jet interaction within the tested parametric range. The degree of thermal enhancement is seen to grow continuously to reach a steady value in the absence of fluid compressibility. The proposed strategy has an intrinsic ability for outstanding thermal characteristics without causing pressure drop increases in microchannel fluid passages, which is identified as a unique feature of the technique.The study also examines and presents the effects of fluid compressibility on the heat removal capacity of this arrangement. The technique is envisaged to have application potential in miniature electronic devices where localised cooling is desired over a base heat dissipation load

    Impact of H1N1 on Socially Disadvantaged Populations: Systematic Review

    Get PDF
    The burden of H1N1 among socially disadvantaged populations is unclear. We aimed to synthesize hospitalization, severe illness, and mortality data associated with pandemic A/H1N1/2009 among socially disadvantaged populations.Studies were identified through searching MEDLINE, EMBASE, scanning reference lists, and contacting experts. Studies reporting hospitalization, severe illness, and mortality attributable to laboratory-confirmed 2009 H1N1 pandemic among socially disadvantaged populations (e.g., ethnic minorities, low-income or lower-middle-income economy countries [LIC/LMIC]) were included. Two independent reviewers conducted screening, data abstraction, and quality appraisal (Newcastle Ottawa Scale). Random effects meta-analysis was conducted using SAS and Review Manager.Sixty-two studies including 44,777 patients were included after screening 787 citations and 164 full-text articles. The prevalence of hospitalization for H1N1 ranged from 17-87% in high-income economy countries (HIC) and 11-45% in LIC/LMIC. Of those hospitalized, the prevalence of intensive care unit (ICU) admission and mortality was 6-76% and 1-25% in HIC; and 30% and 8-15%, in LIC/LMIC, respectively. There were significantly more hospitalizations among ethnic minorities versus non-ethnic minorities in two studies conducted in North America (1,313 patients, OR 2.26 [95% CI: 1.53-3.32]). There were no differences in ICU admissions (n = 8 studies, 15,352 patients, OR 0.84 [0.69-1.02]) or deaths (n = 6 studies, 14,757 patients, OR 0.85 [95% CI: 0.73-1.01]) among hospitalized patients in HIC. Sub-group analysis indicated that the meta-analysis results were not likely affected by confounding. Overall, the prevalence of hospitalization, severe illness, and mortality due to H1N1 was high for ethnic minorities in HIC and individuals from LIC/LMIC. However, our results suggest that there were little differences in the proportion of hospitalization, severe illness, and mortality between ethnic minorities and non-ethnic minorities living in HIC

    Interaction of Co, Mn, Mg and Al with d(GCGTACGC): a spectroscopic study

    No full text
    Spectroscopic study on the interactions of trace elements Co, Mn, Mg and Al with d(GCGTACGC) indicated the following: Al and Mg did not alter Tm values. Mn enhanced Tm at lower concentration and decreased it at higher concentrations. Interestingly Co at higher concentration elevated the Tm. These studies also showed lower concentrations of Mn displaced EtBr, whereas Al could displace it at higher ionic strength. Mg and Co displaced EtBr fluorescence at moderate concentrations. The binding constant values and CD spectra clearly indicated strong binding of these elements to DNA

    Interaction of Co, Mn, Mg and Al with d(GCCCATGGC) and d(CCGGGCCCGG): a spectroscopic study

    No full text
    Spectroscopic study of the interactions of metal ions, Co, Mn, Mg and Al with d(GCCCATGGGC) and d(CCGGGCCCGG) revealed the following. Metal ions Mn, Al and Mg at the lowest concentrations enhanced the t m of oligomers, whereas Mn and Mg at higher concentrations decreased the t m . Co enhanced the t m of oligomers at higher concentrations. The studies have also indicated that Mn at lower concentrations displaced EtBr fluorescence, Mg and Co at moderate concentrations and Al only at higher concentrations. Addition of Co, Mn, Mg and Al altered the bands of the circulars dichroism (CD) spectra of the oligomers in a concentration-dependent manner. The CD spectra of d(GCCCATGGGC) and d(CCGGGCCCGG) indicated B and Z forms of DNA, respectively, in contrast to the A form observed in the crystal structures. Mg and Co at different ionic strength induced Z–B transition in d(CCGGGCCCGG), while Al at higher concentrations induced a Z–A transition. Mn did not induce any transition. This is the first report to show that Al causes structural transitions in sequence-specific oligomers and has strong binding ability with GC-rich euchromatin oligomers

    Hoof size, shape, and balance as possible risk factors for catastrophic musculoskeletal injury of Thoroughbred racehorses

    No full text
    abstract: 95 Thoroughbred racehorses that died between 1994 and 1996 examined through the California Horse Racing Board Postmortem Program were used in this investigation. 38 quantitative measures of hoof size, shape and balance were obtained from orthogonal digital images of the hoof and were compared between case horses with forelimb catastrophic musculoskeletal injuries (CMI, 70 animals), suspensory apparatus failure (SAF, 43), and cannon bone condylar fracture (CDY, 10) injuries and control horses whose death was unrelated to the musculoskeletal system (non-CMI, 25). Comparison of group means between cases and controls was done using ANOVA and multivariable logistic regression was used to estimate odds ratios. Odds of CMI were 0.62 times lower for a 5-mm increase in ground surface width difference and 0.49 times lower for a 100-mm² increase in sole area difference. Odds of SAF were 6.75 times greater with a 10° increase in toe-heel angle difference and 0.58 times lower with a 100-mm² increase in sole area difference. Odds of CDY were 0.26 times lower with a 3° increase in toe angle, 0.15 times lower with a 5-mm increase in lateral ground surface width, and 0.35 times lower with a 100-mm² increase in sole area difference. It is suggested that decreasing the difference between toe and heel angles should decrease risk of SAF for Thoroughbred racehorses and should be considered in addition to increasing toe angle alone to help prevent catastrophic injury. It is added that trimming the hoof to perfect mediolateral symmetry may not be a sound approach to avoiding injury

    Expanded palette of RNA base editors for comprehensive RBP-RNA interactome studies

    No full text
    Abstract RNA binding proteins (RBPs) are key regulators of RNA processing and cellular function. Technologies to discover RNA targets of RBPs such as TRIBE (targets of RNA binding proteins identified by editing) and STAMP (surveying targets by APOBEC1 mediated profiling) utilize fusions of RNA base-editors (rBEs) to RBPs to circumvent the limitations of immunoprecipitation (CLIP)-based methods that require enzymatic digestion and large amounts of input material. To broaden the repertoire of rBEs suitable for editing-based RBP-RNA interaction studies, we have devised experimental and computational assays in a framework called PRINTER (protein-RNA interaction-based triaging of enzymes that edit RNA) to assess over thirty A-to-I and C-to-U rBEs, allowing us to identify rBEs that expand the characterization of binding patterns for both sequence-specific and broad-binding RBPs. We also propose specific rBEs suitable for dual-RBP applications. We show that the choice between single or multiple rBEs to fuse with a given RBP or pair of RBPs hinges on the editing biases of the rBEs and the binding preferences of the RBPs themselves. We believe our study streamlines and enhances the selection of rBEs for the next generation of RBP-RNA target discovery
    corecore