273 research outputs found

    An Imidazolium-Based Supramolecular Gelator Enhancing Interlayer Adhesion in 3D Printed Dual Network Hydrogels

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    The variety of UV-curable monomers for 3D printing is limited by a requirement for rapid curing aftereach sweep depositing a layer. This study proposes to trigger supramolecular self-assembly during theprocess by a gemini imidazolium-based low-molecular-weight gelator, allowing printing of certainmonomers. The as-printed hydrogel structures were supported by a gelator network immobilising monomer:water solutions. A thixotropic hydrogel was formed with a recovery time of 8.1 kPa and yield stress = 18 Pa, processable using material extrusion 3D printing. Material extrusion 3Dprinted objects are usually highly anisotropic, but in this case the gelator network improved the isotropyby subverting the usual layer-by-layer curing strategy. The monomer in all printed layers was curedsimultaneously during post-processing to form a continuous polymeric network. The two networks thenphysically interpenetrate to enhance mechanical performance. The double network hydrogels fabricatedwith layers cured simultaneously showed 62–147% increases in tensile properties compared to layer-bylayercured hydrogels. The results demonstrated excellent inter- and intra-layered coalescence.</p

    3D-Printed Ergonomic Tool Handles

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    Although hand tools serve as an instrument for extending one’s capabilities through the use of hands, the comfort it brings is important especially since the welfare of the user is at stake. Aside from using the hand tools repetitively and with an awkward posture, the tool handle compositions and design also contribute to accumulating some work-related musculoskeletal disorders that require further attention in the long run. To provide a long-term solution, 3D-printed new designs of six commonly used hand tools that fit the average hand measurements of Filipinos have been developed. The hand tools are printed using two filaments namely; thermoplastic polyurethane (TPU) which was found to be skin-friendly and polylactic acid (PLA) which is proven to be more functional, both are used on the outer and inner layer of the handle, respectively. The 3D-printed tool handles were evaluated through the use of a comfort questionnaire for hand tools distributed to 10 respondents per tool handle testing, results show that 3D-printed tool handles are found to be more comfortable and convenient rather than the commercial ones. Meanwhile, the researchers note that the adequate length of tool handles may also vary according to functions and not rely alone on the average hand measurements

    The initial U.S. experience with the Tempo active fixation temporary pacing lead in structural heart interventions

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    ObjectivesThis multicenter retrospective study of the initial U.S. experience evaluated the safety and efficacy of temporary cardiac pacing with the Tempo® Temporary Pacing Lead.BackgroundDespite increasing use of temporary cardiac pacing with the rapid growth of structural heart procedures, temporary pacing leads have not significantly improved. The Tempo lead is a new temporary pacing lead with a soft tip intended to minimize the risk of perforation and a novel active fixation mechanism designed to enhance lead stability.MethodsData from 269 consecutive structural heart procedures were collected. Outcomes included device safety (absence of clinically significant cardiac perforation, new pericardial effusion, or sustained ventricular arrhythmia) and efficacy (clinically acceptable pacing thresholds with successful pace capture throughout the index procedure). Postprocedure practices and sustained lead performance were also analyzed.ResultsThe Tempo lead was successfully positioned in the right ventricle and achieved pacing in 264 of 269 patients (98.1%). Two patients (0.8%) experienced loss of pace capture. Procedural mean pace capture threshold (PCT) was 0.7 ± 0.8 mA. There were no clinically significant perforations, pericardial effusions, or sustained device‐related arrhythmias. The Tempo lead was left in place postprocedure in 189 patients (71.6%) for mean duration of 43.3 ± 0.7 hr (range 2.5–221.3 hr) with final PCT of 0.84 ± 1.04 mA (n = 80). Of these patients, 84.1% mobilized out of bed with no lead dislodgment.ConclusionThe Tempo lead is safe and effective for temporary cardiac pacing for structural heart procedures, provides stable peri and postprocedural pacing and allows mobilization of patients who require temporary pacing leads.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154941/1/ccd28476.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154941/2/ccd28476_am.pd

    Differential (2+1) Jet Event Rates and Determination of alpha_s in Deep Inelastic Scattering at HERA

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    Events with a (2+1) jet topology in deep-inelastic scattering at HERA are studied in the kinematic range 200 < Q^2< 10,000 GeV^2. The rate of (2+1) jet events has been determined with the modified JADE jet algorithm as a function of the jet resolution parameter and is compared with the predictions of Monte Carlo models. In addition, the event rate is corrected for both hadronization and detector effects and is compared with next-to-leading order QCD calculations. A value of the strong coupling constant of alpha_s(M_Z^2)= 0.118+- 0.002 (stat.)^(+0.007)_(-0.008) (syst.)^(+0.007)_(-0.006) (theory) is extracted. The systematic error includes uncertainties in the calorimeter energy calibration, in the description of the data by current Monte Carlo models, and in the knowledge of the parton densities. The theoretical error is dominated by the renormalization scale ambiguity.Comment: 25 pages, 6 figures, 3 tables, submitted to Eur. Phys.

    University Educator and Staff Well-being and Common Mental Health Symptoms during the COVID-19 Pandemic in the Philippines

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    Educators and staff adapted to work-from-home setup amidst the covid-19 pandemic.  The transition to full-online classes and services leads to poor mental health. The current study explored the association of educator and staff personal characteristics, well-being, and mental health.  326 university employees completed the demographic profile, mental health, and well-being scales. Various hierarchical regression was conducted to determine if personal characteristics and well-being predict common mental health symptoms (depression, anxiety, and stress). Series of multivariate analyses of variance (MANOVA) was conducted to determine the difference between the levels of mental health symptoms according to mental health category, and personal characteristics. The results support the hypothesis with psychological and emotional well-being inversely predicting depression, anxiety, and stress. However, social well-being failed to serve as a significant determinant of common mental health symptoms. MANOVA obtained a significant difference with common mental health symptoms and mental health category and personal characteristics

    Single-nucleotide polymorphism associations with preterm delivery: a case-control replication study and meta-analysis

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    BackgroundThe aim of this study was to replicate single-nucleotide polymorphism (SNP) associations with preterm birth (PTB; birth at MethodsSpontaneous PTB cases and controls were selected from an existing cohort. Candidate SNPs were taken from an existing genotype panel. A systematic review was conducted for each SNP in the panel to determine suitability as a PTB candidate. Those with significant associations previously reported in Caucasians were selected for replication. Candidate SNPs were already genotyped in cases and controls and clinical data were accessed from state perinatal and cerebral palsy databases. Association analysis was conducted between each SNP and PTB, and meta-analysis was conducted if there were ≥ 3 studies in the literature. Maternal and fetal SNPs were considered as separate candidates.ResultsA cohort of 170 cases and 583 controls was formed. Eight SNPs from the original panel of genotyped SNPs were selected as PTB candidates and for replication on the basis of systematic literature review results. In our cohort, fetal factor V Leiden (FVL) was significantly associated with PTB (odds ratio (OR): 2.6, 95% confidence interval (CI): 1.31-5.17), and meta-analysis confirmed this association (OR: 2.71, 95% CI: 1.15-6.4).ConclusionReplication and meta-analysis support an increased risk of PTB in Caucasians with the fetal FVL mutation.Michael E. O’Callaghan, Alastair H. MacLennan, Gai L. McMichael, Eric A. Haan and Gustaaf A. Dekke

    Early pregnancy peripheral blood gene expression and risk of preterm delivery: a nested case control study

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    <p>Abstract</p> <p>Background</p> <p>Preterm delivery (PTD) is a significant public health problem associated with greater risk of mortality and morbidity in infants and mothers. Pathophysiologic processes that may lead to PTD start early in pregnancy. We investigated early pregnancy peripheral blood global gene expression and PTD risk.</p> <p>Methods</p> <p>As part of a prospective study, ribonucleic acid was extracted from blood samples (collected at 16 weeks gestational age) from 14 women who had PTD (cases) and 16 women who delivered at term (controls). Gene expressions were measured using the GeneChip<sup>® </sup>Human Genome U133 Plus 2.0 Array. Student's T-test and fold change analysis were used to identify differentially expressed genes. We used hierarchical clustering and principle components analysis to characterize signature gene expression patterns among cases and controls. Pathway and promoter sequence analyses were used to investigate functions and functional relationships as well as regulatory regions of differentially expressed genes.</p> <p>Results</p> <p>A total of 209 genes, including potential candidate genes (e.g. PTGDS, prostaglandin D2 synthase 21 kDa), were differentially expressed. A set of these genes achieved accurate pre-diagnostic separation of cases and controls. These genes participate in functions related to immune system and inflammation, organ development, metabolism (lipid, carbohydrate and amino acid) and cell signaling. Binding sites of putative transcription factors such as EGR1 (early growth response 1), TFAP2A (transcription factor AP2A), Sp1 (specificity protein 1) and Sp3 (specificity protein 3) were over represented in promoter regions of differentially expressed genes. Real-time PCR confirmed microarray expression measurements of selected genes.</p> <p>Conclusions</p> <p>PTD is associated with maternal early pregnancy peripheral blood gene expression changes. Maternal early pregnancy peripheral blood gene expression patterns may be useful for better understanding of PTD pathophysiology and PTD risk prediction.</p
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