1,117 research outputs found
Disentangling unclear nuclear breakup channels of beryllium-9 using the three-axis Dalitz plot
The three-axis Dalitz plot has been applied to the breakup of a nucleus into unequal mass fragments for the first time. The Dalitz plot allows clear identification of the various breakup channels of 9Be → 2α + n process. The method has allowed the branching ratio for the 6.38 MeV level in9Be to be provisionally calculated when examining the 9Be(4He, α)ααn reaction. The effects of non-uniform angular distributions on the Dalitz plot must still be properly investigated along with the effects of contaminant reaction channels. It is proposed that this method could be used to determine the breakup branching ratio of a newly-measured level in this nucleus
Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
Measurement of the t¯tZ and t¯tW cross sections in proton-proton collisions at √s=13 TeV with the ATLAS detector
A measurement of the associated production of a top-quark pair (t¯t) with a vector boson (W, Z) in proton-proton collisions at a center-of-mass energy of 13 TeV is presented, using 36.1 fb−1 of integrated luminosity collected by the ATLAS detector at the Large Hadron Collider. Events are selected in channels with two same- or opposite-sign leptons (electrons or muons), three leptons or four leptons, and each channel is further divided into multiple regions to maximize the sensitivity of the measurement. The t¯tZ and t¯tW production cross sections are simultaneously measured using a combined fit to all regions. The best-fit values of the production cross sections are σt¯tZ=0.95±0.08stat±0.10syst pb and σt¯tW=0.87±0.13stat±0.14syst pb in agreement with the Standard Model predictions. The measurement of the t¯tZ cross section is used to set constraints on effective field theory operators which modify the t¯tZ vertex
Excited states of <sup>12</sup>C above the alpha-decay threshold
The excitation energy spectrum of 12C is important for both structural and astrophysical reasons; here we present evidence for a new state in 12C. The two reactions 12C(4He, 4He+4He+4He)4He and 9Be(4He,4He+4He+4He)n were measured using an array of four double sided strip detectors. Excited states in 12C were reconstructed filtered by the condition that the alpha-decay proceeded via the 8Be ground-state. In both measurements evidence was found for a new state at 13.3(0.2) MeV with a width 1.7(0.2) MeV. Angular correlation measurements from the 12C(4He, 4He+4He+4He)4He reaction indicates that the state may have Jpi =4+. © Published under licence by IOP Publishing Ltd.</p
The Impact of miRNA Target Sites in Coding Sequences and in 3′UTRs
Animal miRNAs are a large class of small regulatory RNAs that are known to directly and negatively regulate the expression of a large fraction of all protein encoding genes. The identification and characterization of miRNA targets is thus a fundamental problem in biology. miRNAs regulate target genes by binding to 3′ untranslated regions (3′UTRs) of target mRNAs, and multiple binding sites for the same miRNA in 3′UTRs can strongly enhance the degree of regulation. Recent experiments have demonstrated that a large fraction of miRNA binding sites reside in coding sequences. Overall, miRNA binding sites in coding regions were shown to mediate smaller regulation than 3′UTR binding. However, possible interactions between target sites in coding sequences and 3′UTRs have not been studied. Using transcriptomics and proteomics data of ten miRNA mis-expression experiments as well as transcriptome-wide experimentally identified miRNA target sites, we found that mRNA and protein expression of genes containing target sites both in coding regions and 3′UTRs were in general mildly but significantly more regulated than those containing target sites in 3′UTRs only. These effects were stronger for conserved target sites of length 7–8 nt in coding regions compared to non-conserved sites. Combined with our other finding that miRNA target sites in coding regions are under negative selection, our results shed light on the functional importance of miRNA targeting in coding regions
Higher Post-Acute Health Care Costs Following SARS-CoV-2 Infection Among Adults in Ontario, Canada
Candace D McNaughton,1– 4 Peter C Austin,1,2,4 Zhiyin Li,1 Atul Sivaswamy,1 Jiming Fang,1 Husam Abdel-Qadir,1,3– 5 Jacob A Udell,1,5 Walter P Wodchis,1,4,6 Douglas S Lee,1,3,4,7 Ivona Mostarac,2 Clare L Atzema1– 4 1ICES (Formerly, the Institute for Clinical Evaluative Sciences), Toronto, Ontario, Canada; 2Sunnybrook Research Institute, Toronto, Ontario, Canada; 3Department of Medicine, University of Toronto, Toronto, Ontario, Canada; 4Institute of Health Policy, Management and Evaluation, Toronto, ON, Canada; 5Division of Cardiology, Women’s College Hospital, Toronto, Ontario, Canada; 6Institute for Better Health, Trillium Health Partners, Mississauga, ON, Canada; 7Ted Rogers Centre for Heart Research, Toronto, Ontario, CanadaCorrespondence: Candace D McNaughton, Email [email protected] and Introduction: Growing evidence suggests SARS-CoV-2 infection increases the risk of long term cardiovascular, neurological, and other effects. However, post-acute health care costs following SARS-CoV-2 infection are not known.Patients and Statistical Methods: Beginning 56 days following SARS-CoV-2 polymerase chain reaction (PCR) testing, we compared person-specific total and component health care costs (2020 CAD$) for the first year of follow-up at the mean and 99th percentiles of health care costs for matched test-positive and test-negative adults in Ontario, Canada, between January 1, 2020, and March 31, 2021. Matching included demographics, baseline clinical characteristics, and two-week time blocks.Results: For 531,182 people, mean person-specific total health care costs were $513.83 (95% CI $387.37-$638.40) higher for test-positive females and $459.10 (95% CI $304.60-$615.32) higher for test-positive males, which were driven by hospitalization, long-term care, and complex continuing care costs. At the 99th percentile of each subgroup, person-specific health care costs were $12,533.00 (95% CI $9008.50-$16,473.00) higher for test-positive females and $14,604.00 (95% CI $9565.50-$19,506.50) for test-positive males, driven by hospitalization, specialist (males), and homecare costs (females). Cancer costs were lower. Six-month and 1-year cost differences were similar.Conclusion: Post-acute health care costs after a positive SARS-CoV-2 PCR test were significantly higher than matched test-negative individuals, and these increased costs persisted for at least one year. The largest increases health care costs came from hospitalizations, long-term care, complex continuing care, followed by outpatient specialists (for males) and homecare costs (for women). Given the magnitude of ongoing viral spread, policymakers, clinicians, and patients should be aware of higher post-acute health care costs following SARS-CoV-2 infection.Plain Language Summary: We examined differences in health care costs for people who had a positive PCR for SARS-CoV-2 in Ontario, Canada, starting 56 days after the positive test at looking forward at least 1 year, matched by > 20 characteristics to people with a negative PCR within two weeks. During the study, the average health care costs per person were approximately $4800 (2020 CAD$). We found that on average, health care costs were $513.83 higher (2020 CAD$; +11% higher than average health care costs) for women who had a positive PCR test and $459.10 higher (+10% higher than average health care costs) for men who had a positive PCR test. Most of the increased costs were due to hospitalization, long-term care, and complex continuing care costs.When we looked at people who had the highest health care costs (the 99th percentile), health care costs for women with a positive PCR test were $12,533.00 higher (+261% higher than average health care costs) and $14,604.00 higher for men (+304% higher than average health care costs), with higher costs driven by hospitalization, specialist (males), and homecare costs (females). Cancer costs were lower for people with a positive test. In summary, post-acute health care costs were higher for people who had a positive SARS-CoV-2 PCR test, after accounting for multiple patient-level factors. Higher costs persisted for a least one year of follow-up.Keywords: long COVID, health policy, sex difference
Generation of subject-specific, dynamic, multisegment ankle and foot models to improve orthotic design: a feasibility study
ABSTRACT: BACKGROUND: Currently, custom foot and ankle orthosis prescription and design tend to be based on traditional techniques, which can result in devices which vary greatly between clinicians and repeat prescription. The use of computational models of the foot may give further insight in the biomechanical effects of these devices and allow a more standardised approach to be taken to their design, however due to the complexity of the foot the models must be highly detailed and dynamic. METHODS: Functional and anatomical datasets will be collected in a multicentre study from 10 healthy participants and 15 patients requiring orthotic devices. The patient group will include individuals with metarsalgia, flexible flat foot and drop foot. Each participant will undergo a clinical foot function assessment, 3D surface scans of the foot under different loading conditions, and detailed gait analysis including kinematic, kinetic, muscle activity and plantar pressure measurements in both barefoot and shod conditions. Following this each participant will undergo computed tomography (CT) imaging of their foot and ankle under a range of loads and positions while plantar pressures are recorded. A further subgroup of participants will undergo magnetic resonance imaging (MRI) of the foot and ankle. Imaging data will be segmented to derive the size of bones and orientation of the joint axes. Insertion points of muscles and ligaments will be determined from the MRI and CT-scans and soft tissue material properties computed from the loaded CT data in combination with the plantar pressure measurements. Gait analysis data will be used to drive the models and in combination with the 3D surface scans for scaling purposes. Predicted plantar pressures and muscle activation patterns predicted from the models will be compared to determine the validity of the models. DISCUSSION: This protocol will lead to the generation of unique datasets which will be used to develop linked inverse dynamic and forward dynamic biomechanical foot models. These models may be beneficial in predicting the effect of and thus improving the efficacy of orthotic devices for the foot and ankle
Cross Priming Amplification: Mechanism and Optimization for Isothermal DNA Amplification
CPA is a class of isothermal amplification reactions that is carried out by a strand displacement DNA polymerase and does not require an initial denaturation step or the addition of a nicking enzyme. At the assay temperature of 63°C, the formation of a primer-template hybrid at transient, spontaneous denaturation bubbles in the DNA template is favored over re-annealing of the template strands by the high concentration of primer relative to template DNA. Strand displacement is encouraged by the annealing of cross primers with 5′ ends that are not complementary to the template strand and the binding of a displacement primer upstream of the crossing primer. The resulting exponential amplification of target DNA is highly specific and highly sensitive, producing amplicons from as few as four bacterial cells. Here we report on the basic CPA mechanism – single crossing CPA – and provide details on alternative mechanisms
A Simple and Accurate Two-Step Long DNA Sequences Synthesis Strategy to Improve Heterologous Gene Expression in Pichia
In vitro gene chemical synthesis is a powerful tool to improve the expression of gene in heterologous system. In this study, a two-step gene synthesis strategy that combines an assembly PCR and an overlap extension PCR (AOE) was developed. In this strategy, the chemically synthesized oligonucleotides were assembled into several 200–500 bp fragments with 20–25 bp overlap at each end by assembly PCR, and then an overlap extension PCR was conducted to assemble all these fragments into a full length DNA sequence. Using this method, we de novo designed and optimized the codon of Rhizopus oryzae lipase gene ROL (810 bp) and Aspergillus niger phytase gene phyA (1404 bp). Compared with the original ROL gene and phyA gene, the codon-optimized genes expressed at a significantly higher level in yeasts after methanol induction. We believe this AOE method to be of special interest as it is simple, accurate and has no limitation with respect to the size of the gene to be synthesized. Combined with de novo design, this method allows the rapid synthesis of a gene optimized for expression in the system of choice and production of sufficient biological material for molecular characterization and biotechnological application
Synthesis of compact ZSM-5 zeolite membrane by adding the promoter NaCl
The compact ZSM-5 membranes was synthesized on porous alumina substrates by pre-coating narrosized ZSM-5 seeds and then employing the twice hydrothermal synthesis with adding the promoter NaCl. Effect of Na+ concentration on the formation of membrane was investigated in this work, indicating that adding a certain mount of NaCl can boost the growth of zeolite crystals on the substrates, thus forming the compact membrane consisted of highly intergrown crystals. The separating performance of zeolite membranes indicated that using a mixture with a composition of Al2O3: 84SiO(2): 10Na(2)O: 100NaCl: 15TPABr: 3500H(2)O as synthesis gel, the ideal selectivity of H-2/C3H8 could reach a maximum value of 23.7 at room temperature and pressure difference of 0.1 MPa, and the permselectivity decreased to 9.4 at testing temperature of 200 degreesC, which is still higher than the corresponding Knudsen diffusion value (4.69), suggesting that the membrane synthesized by this method was defect-free
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