2,970 research outputs found

    Multiple Broken Symmetries in Striped La2x_{2-x}Bax_{x}CuO4_{4} detected by the Field Symmetric Nernst Effect

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    We report on a thermoelectric investigation of the stripe and superconducting phases of the cuprate La2x_{2-x}Bax_{x}CuO4_{4} near the x=1/8x=1/8 doping known to host stable stripes. We use the doping and magnetic field dependence of field-symmetric Nernst effect features to delineate the phenomenology of these phases. Our measurements are consistent with prior reports of time-reversal symmetry breaking signatures above the superconducting TcT_{{\rm c}}, and crucially detect a sharp, robust, field-invariant peak at the stripe charge order temperature, TCOT_{{\rm {\scriptscriptstyle CO}}}. Our observations suggest the onset of a nontrivial charge ordered phase at TCOT_{{\rm {\scriptscriptstyle CO}}}, and the subsequent presence of spontaneously generated vortices over a broad temperature range before the emergence of bulk superconductivity in LBCO

    An Ultra-High-Vacuum Rotating Sample Manipulator with Cryogenic Cooling

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    We report a homebuilt ultra-high-vacuum (UHV) rotating sample manipulator with cryogenic cooling. The sample holder is thermally anchored to a built-in cryogenic cold head through flexible copper beryllium strips, permitting continuous sample rotation. A similar contact mechanism is implemented for the electrical wiring to the sample holder for thermometry. The apparatus thus enables continuous sample rotation at regulated cryogenic temperatures in a UHV environment. We discuss the potential applications of this apparatus for cryogenic sputtering.Comment: Cryogenics, ultra-high vacuum, sample manipulato

    Penetration depth study of LaOs4_4Sb12_{12}: Multiband s-wave superconductivity

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    We measured the magnetic penetration depth λ(T)\lambda(T) in single crystals of LaOs4_{4}Sb12_{12} (TcT_c=0.74 K) down to 85 mK using a tunnel diode oscillator technique. The observed low-temperature exponential dependence indicates a s-wave gap. Fitting the low temperature data to BCS s-wave expression gives the zero temperature gap value Δ(0)=(1.34±0.07)kBTc\Delta (0)= (1.34 \pm 0.07) k_B T_c which is significantly smaller than the BCS value of 1.76kBTck_B T_c. In addition, the normalized superfluid density ρ(T)\rho(T) shows an unusually long suppression near TcT_c, and are best fit by a two-band s-wave model.Comment: 5 pages, 2 figure

    ‘Pseudopneumothorax’—Hold that chest tube!

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    We report a case of herniation of abdominal contents into the left hemithorax in a patient with a history of vague left-sided thoracoabdominal trauma 18 days previous to admission and who also had a recent 1-week history of upper respiratory symptoms, including cough, and then presented with dyspnoea and fever for 3 days. There was no preceding cardiorespiratory pathology of note. We also discuss the epidemiology, pathogenesis and management of blunt-traumatic diaphragmatic rupture

    Effects of Escherichia coli vaccination in gilts on piglet performance in a farm in Perak

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    This study aimed to observe the effects of Escherichia coli (Neocoliporvaccine – Merial) vaccination on diarrhoea percentages, growth parameters (average weight per piglet and average daily gain) and mortality rate in new-born piglets. A field trial was conducted in 35 litters of piglets from gilts selected from a farm in Perak. They were randomly allocated into Treatment (16 litters from E. coli vaccinated gilts) and Control (19 litters) groups respectively. Body weights of the piglets were measured at days 1, 7, 14 and 21 of age and the episodes of diarrhoea and piglet mortality were monitored daily for each pen. The Treatment group had significantly lower Day 1 neonatal diarrhoea percentage (p 0.05)in the overall diarrhoea percentages (1 - 14 days) and weekly growth parameters between both groups. Environmental stress and inevitable routine treatment of diarrhoea with antimicrobials within the farm may have affected the significance of the diarrhoea percentages and growth parameters in this study. In conclusion, E. coli vaccination in gilts was shown to significantly reduce piglet mortality from Day 1 to Day 7 and neonatal diarrhoeal percentageson1-day-old piglets under typical farm conditions in this pilot study in Malaysia

    Tapered microchannel for multi-particles passive separation based on hydrodynamic resistance

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    Researches on separation of multi-particles utilizing microfluidic have been flourishing in recent years with the aid from advancements in microfabrication design and technology. Generally, separation is beneficial for biomedical application especially involving heterogeneous samples. Due to inherent problems of samples isolation, a simple and efficient separation device is required. Here, we present a passive tapered microchannel for multi-particles separation using hydrodynamic principle. Our emphasis is on the effect of hydrodynamic resistance coupled with tapered microchannel design. In the experiment, successful multi-particles samples separation was observed. The results were further analyzed and were in agreement with the proposed concept. This method opens the route toward robust, low-cost and high-throughput, thus it may holds potential to be integrated as one functional module in Micro Total Analysis System (µTAS)

    Hydrodynamics of Intravitreal Injections into Liquid Vitreous Substitutes

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    Intravitreal injections have become the cornerstone of retinal care and one of the most commonly performed procedures across all medical specialties. The impact of hydrodynamic forces of intravitreal solutions when injected into vitreous or vitreous substitutes has not been well described. While computational models do exist, they tend to underestimate the starting surface area of an injected bolus of a drug. Here, we report the dispersion profile of a dye bolus (50 µL) injected into different vitreous substitutes of varying viscosities, surface tensions, and volumetric densities. A novel 3D printed in vitro model of the vitreous cavity of the eye was designed to visualize the dispersion profile of solutions when injected into the following vitreous substitutes-balanced salt solution (BSS), sodium hyaluronate (HA), and silicone oils (SO)-using a 30G needle with a Reynolds number (Re) for injection ranging from approximately 189 to 677. Larger bolus surface areas were associated with faster injection speeds, lower viscosity of vitreous substitutes, and smaller difference in interfacial surface tensions. Boluses exhibited buoyancy when injected into standard S1000. The hydrodynamic properties of liquid vitreous substitutes influence the initial injected bolus dispersion profile and should be taken into account when simulating drug dispersion following intravitreal injection at a preclinical stage of development, to better inform formulations and performance

    Mendelian randomization study of B-type natriuretic peptide and type 2 diabetes: evidence of causal association from population studies

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    <p>Background: Genetic and epidemiological evidence suggests an inverse association between B-type natriuretic peptide (BNP) levels in blood and risk of type 2 diabetes (T2D), but the prospective association of BNP with T2D is uncertain, and it is unclear whether the association is confounded.</p> <p>Methods and Findings: We analysed the association between levels of the N-terminal fragment of pro-BNP (NT-pro-BNP) in blood and risk of incident T2D in a prospective case-cohort study and genotyped the variant rs198389 within the BNP locus in three T2D case-control studies. We combined our results with existing data in a meta-analysis of 11 case-control studies. Using a Mendelian randomization approach, we compared the observed association between rs198389 and T2D to that expected from the NT-pro-BNP level to T2D association and the NT-pro-BNP difference per C allele of rs198389. In participants of our case-cohort study who were free of T2D and cardiovascular disease at baseline, we observed a 21% (95% CI 3%-36%) decreased risk of incident T2D per one standard deviation (SD) higher log-transformed NT-pro-BNP levels in analysis adjusted for age, sex, body mass index, systolic blood pressure, smoking, family history of T2D, history of hypertension, and levels of triglycerides, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol. The association between rs198389 and T2D observed in case-control studies (odds ratio = 0.94 per C allele, 95% CI 0.91-0.97) was similar to that expected (0.96, 0.93-0.98) based on the pooled estimate for the log-NT-pro-BNP level to T2D association derived from a meta-analysis of our study and published data (hazard ratio = 0.82 per SD, 0.74-0.90) and the difference in NT-pro-BNP levels (0.22 SD, 0.15-0.29) per C allele of rs198389. No significant associations were observed between the rs198389 genotype and potential confounders.</p> <p>Conclusions: Our results provide evidence for a potential causal role of the BNP system in the aetiology of T2D. Further studies are needed to investigate the mechanisms underlying this association and possibilities for preventive interventions.</p&gt

    JMJD6 is a tumorigenic factor and therapeutic target in neuroblastoma

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    Chromosome 17q21-ter is commonly gained in neuroblastoma, but it is unclear which gene in the region is important for tumorigenesis. The JMJD6 gene at 17q21-ter activates gene transcription. Here we show that JMJD6 forms protein complexes with N-Myc and BRD4, and is important for E2F2, N-Myc and c-Myc transcription. Knocking down JMJD6 reduces neuroblastoma cell proliferation and survival in vitro and tumor progression in mice, and high levels of JMJD6 expression in human neuroblastoma tissues independently predict poor patient prognosis. In addition, JMJD6 gene is associated with transcriptional super-enhancers. Combination therapy with the CDK7/super-enhancer inhibitor THZ1 and the histone deacetylase inhibitor panobinostat synergistically reduces JMJD6, E2F2, N-Myc, c-Myc expression, induces apoptosis in vitro and leads to neuroblastoma tumor regression in mice, which are significantly reversed by forced JMJD6 over-expression. Our findings therefore identify JMJD6 as a neuroblastoma tumorigenesis factor, and the combination therapy as a treatment strategy
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