140 research outputs found
Experimental modelling of evaporation and boiling processes in a two-phase thermosyphon
A model of a closed two-phase thermosyphon was developed to study thermo-physical processes in a thermosyphon thermal condition systems of energy-saturated equipment. This model differs from the known by reasoned choice of thermocouples installation providing sealing the device during operation. In addition, the program VI (Virtual Instrument) was created in graphical environment Labview for registration of the temperatures and pressure in the thermosyphon
The effect of non-ablative thermomechanical skin treatment (Tixel®) on dry eye disease: A prospective two centre open-label trial
Purpose: To determine the effects of a thermo-mechanical action-based peri-orbital fractional skin treatment (Tixel®) on dry eye disease. Methods: This prospective, controlled, open labelled study was conducted at two study centres: Midland Eye, Solihull, UK, and Vallmedic Vision, Andorra. Participants were screened at the baseline visit (visit-1), received three Tixel® treatments at 2-weeks intervals including further assessment (visits 2, 3 and 4). Participants were followed up for three months post-treatment (visit 5). Vision, intraocular pressure (IOP), dry eye symptomatology were assessed, including the Ocular Surface Disease Index (OSDI) questionnaire, non-invasive tear break-up time (NIBUT) and tear osmolarity as well as detailed ophthalmic assessments. Results: Seventy-four participants (41 in Birmingham and 33 in Andorra) with periorbital wrinkles and moderate to severe dry eye disease (DED) were enrolled. The mean age was 59.3 ± 13.3 years and 57 were females. No adverse events, no change in vision (p = 0.310) or IOP (p = 0.419) were observed. Tixel treatment was associated with clinically and statistically significant improvement in the DED symptoms, which was supported by a reduction of 21.40 ± 15.08 (P < 0.001) of the OSDI index. Non-invasive tear break-up time improved by 2.10 ± 0.91 s (p < 0.001) in the Birmingham cohort and 6.60 ± 2.13 s (p < 0.001) in the Andorra cohort. Tear osmolarity reduced from 299.8 ± 13.3 mOsm/L to 298.8 ± 15.6 mOsm/L following the Tixel treatment (p = 0.271). Conclusions: Thermo-mechanical action-based peri-orbital fractional skin treatment Tixel® could be an attractive, safe and effective treatment for DED. This treatment is associated with high clinical and statistically significant improvement in DED signs and symptoms with no adverse events
Hypoxia-inducible factor-1 (HIF-1) pathway activation by quercetin in human lens epithelial cells
Quercetin is a dietary bioflavonoid which has been shown to inhibit lens opacification in a number of models of cataract. The objectives of this study were to determine gene expression changes in human lens epithelial cells in response to quercetin and to investigate in detail the mechanisms underlying the responses. FHL-124 cells were treated with quercetin (10 µM) and changes in gene expression were measured by microarray. It was found that 65% of the genes with increased expression were regulated by the hypoxia-inducible factor-1 (HIF-1) pathway. Quercetin (10 and 30 µM) induced a time-dependent increase in HIF-1a protein levels. Quercetin (30 µM) was also responsible for a rapid and long-lasting translocation of HIF-1a from the cytoplasm to the nucleus. Activation of HIF-1 signaling by quercetin was confirmed by qRT–PCR which showed upregulation of the HIF-1 regulated genes EPO, VEGF, PGK1 and BNIP3. Analysis of medium taken from FHL-124 cells showed a sustained dose-dependent increase in VEGF secretion following quercetin treatment. The quercetin-induced increase and nuclear translocation of HIF-1a was reversed by addition of excess iron (100 µM). These results demonstrate that quercetin activates the HIF-1 signaling pathway in human lens epithelial cells
Electrical detection of magnetic skyrmions by non-collinear magnetoresistance
Magnetic skyrmions are localised non-collinear spin textures with high
potential for future spintronic applications. Skyrmion phases have been
discovered in a number of materials and a focus of current research is the
preparation, detection, and manipulation of individual skyrmions for an
implementation in devices. Local experimental characterization of skyrmions has
been performed by, e.g., Lorentz microscopy or atomic-scale tunnel
magnetoresistance measurements using spin-polarised scanning tunneling
microscopy. Here, we report on a drastic change of the differential tunnel
conductance for magnetic skyrmions arising from their non-collinearity: mixing
between the spin channels locally alters the electronic structure, making a
skyrmion electronically distinct from its ferromagnetic environment. We propose
this non-collinear magnetoresistance (NCMR) as a reliable all-electrical
detection scheme for skyrmions with an easy implementation into device
architectures
<i>CYLD</i> mutations differentially affect splicing and mRNA decay in Brooke-Spiegler syndrome
Regional and scale-specific effects of land use on amphibian diversity [poster]
Background/Question/Methods
Habitat loss and degradation influence amphibian distributions and are important drivers of population declines. Our previous research demonstrated that road disturbance, development and wetland area consistently influence amphibian richness across regions of the U.S. Here, we examined the relative importance of these factors in different regions and at multiple spatial scales. Understanding the scales at which habitat disturbance may be affecting amphibian distributions is important for conservation planning. Specifically, we asked: 1) Over what spatial scales do distinct landscape features affect amphibian richness? and 2) Do road types (non-rural and rural) have similar effects on amphibian richness? This is the second year of a collaborative, nationwide project involving 11 U.S. colleges integrated within undergraduate biology curricula. We summarized North American Amphibian Monitoring Program data in 13 Eastern and Central U.S states and used geographic information systems to extract landscape data for 471 survey locations. We developed models to quantify the influence of landscape variables on amphibian species richness and site occupancy across five concentric buffers ranging from 300m to 10,000m.
Results/Conclusions
Across spatial scales, development, road density and agriculture were the best predictors of amphibian richness and site occupancy by individual species. Across regions, we found that scale did not exert a large influence on how landscape features influenced amphibian richness as effects were largely comparable across buffers. However, development and percent impervious surface had stronger influence on richness at smaller spatial scales. Richness was lower at survey locations with higher densities of non-rural and rural roads, and non-rural road density had a larger negative effect at smaller scales. Within regions, landscape features driving patterns of species richness varied. The scales at which these factors were associated with richness were highly variable within regions, suggesting the scale effects may be region specific. Our project demonstrates that networks of undergraduate students can collaborate to compile and analyze large ecological data sets, while engaging students in authentic and inquiry-based learning in landscape-scale ecology
Pars plana vitrectomy for diabetic macular edema. Internal limiting membrane delamination vs posterior hyaloid removal. A prospective randomized trial
To access publisher full text version of this article. Please click on the hyperlink in Additional Links field.BACKGROUND: Diabetes mellitus, as well as subsequent ocular complications such as cystoid macular edema (CME), are of fundametal socio-economic relevance. Therefore, we evaluated the influence of internal limiting membrane (ILM) removal on longterm morphological and functional outcome in patients with diabetes mellitus (DM) type 2 and chronic CME without evident vitreomacular traction. METHOD: Forty eyes with attached posterior hyaloid were included in this prospective trial and randomized intraoperatively. Prior focal (n = 31) or panretinal (n = 25) laser coagulation was permitted. Group I (n = 19 patients) underwent surgical induction of posterior vitreous detachment (PVD), group II (n = 20 patients) PVD and removal of the ILM. Eleven patients with detached posterior hyaloid (group III) were not randomized, and ILM removal was performed. One eye had to be excluded from further analysis. Examinations included ETDRS best-corrected visual acuity (BCVA), fluorescein angiography (FLA) and OCT at baseline, 3 and 6 months postoperatively. Main outcome measure was BCVA at 6 months, secondary was foveal thickness. RESULTS: Mean BCVA over 6 months remained unchanged in 85% of patients of group II, and decreased in 53% of patients of group I. Results were not statistically significant different [group I: mean decrease log MAR 95% CI (0.06; 0.32), group II: (-0.02; 0.11)]. OCT revealed a significantly greater reduction of foveal thickness following PVD with ILM removal [group I: mean change: 95% CI (-208.95 μm; -78.05 μm), group II: (-80.90 μm: +59.17 μm)]. CONCLUSION: Vitrectomy, PVD with or without ILM removal does not improve vision in patients with DM type 2 and cystoid diabetic macular edema without evident vitreoretinal traction. ILM delamination shows improved morphological results, and appears to be beneficial in eyes with preexisting PVD
Обновленные рекомендации EULAR/ERA–EDTA 2019 г. по терапии волчаночного нефрита. Комментарии экспертов. Часть II
The paper presents the main provisions of the updated 2019 EULAR/ERA-EDTA guidelines for the lupus nephritis (LN) therapy, which have been prepared by an international group of rheumatologists, nephrologists, morphologists, and pediatricians. Part 2 of the article discusses additional therapy, monitoring, and prognosis for LN, and the management of patients with end-stage renal failure and antiphospholipid syndrome. Attention is paid to the problem of LN and pregnancy, as well as to the management of pediatric patients with kidney damage.Представлены основные положения обновленных рекомендаций EULAR/ERA–EDTA 2019 г. по терапии волчаночного нефрита (ВН), подготовленных международной группой ревматологов, нефрологов, морфологов и педиатров. Во второй части статьи обсуждаются дополнительная терапия, мониторинг и прогноз при ВН, вопросы ведения пациентов с терминальной почечной недостаточностью, антифосфолипидным синдромом. Уделено внимание проблеме ВН и беременности, а также тактике ведения пациентов детского возраста с поражением почек
Six Novel Susceptibility Loci for Early-Onset Androgenetic Alopecia and Their Unexpected Association with Common Diseases
Androgenetic alopecia (AGA) is a highly heritable condition and the most common form of hair loss in humans. Susceptibility loci have been described on the X chromosome and chromosome 20, but these loci explain a minority of its heritable variance. We conducted a large-scale meta-analysis of seven genome-wide association studies for early-onset AGA in 12,806 individuals of European ancestry. While replicating the two AGA loci on the X chromosome and chromosome 20, six novel susceptibility loci reached genome-wide significance (p = 2.62×10−9–1.01×10−12). Unexpectedly, we identified a risk allele at 17q21.31 that was recently associated with Parkinson's disease (PD) at a genome-wide significant level. We then tested the association between early-onset AGA and the risk of PD in a cross-sectional analysis of 568 PD cases and 7,664 controls. Early-onset AGA cases had significantly increased odds of subsequent PD (OR = 1.28, 95% confidence interval: 1.06–1.55, p = 8.9×10−3). Further, the AGA susceptibility alleles at the 17q21.31 locus are on the H1 haplotype, which is under negative selection in Europeans and has been linked to decreased fertility. Combining the risk alleles of six novel and two established susceptibility loci, we created a genotype risk score and tested its association with AGA in an additional sample. Individuals in the highest risk quartile of a genotype score had an approximately six-fold increased risk of early-onset AGA [odds ratio (OR) = 5.78, p = 1.4×10−88]. Our results highlight unexpected associations between early-onset AGA, Parkinson's disease, and decreased fertility, providing important insights into the pathophysiology of these conditions
Neural protection by naturopathic compounds—an example of tetramethylpyrazine from retina to brain
Given the advantages of being stable in the ambient environment, being permeable to the blood–brain and/or blood–eye barriers and being convenient for administration, naturopathic compounds have growingly become promising therapeutic candidates for neural protection. Extracted from one of the most common Chinese herbal medicines, tetramethylpyrazine (TMP), also designated as ligustrazine, has been suggested to be neuroprotective in the central nervous system as well as the peripheral nerve network. Although the detailed molecular mechanisms of its efficacy for neural protection are understood limitedly, accumulating evidence suggests that antioxidative stress, antagonism for calcium, and suppression of pro-inflammatory factors contribute significantly to its neuroprotection. In animal studies, systemic administration of TMP (subcutaneous injection, 50 mg/kg) significantly blocked neuronal degeneration in hippocampus as well as the other vulnerable regions in brains of Sprague–Dawley rats following kainate-induced prolonged seizures. Results from us and others also demonstrated potent neuroprotective efficacy of TMP for retinal cells and robust benefits for brain in Alzheimer’s disease or other brain injury. These results suggest a promising prospect for TMP to be used as a treatment of specific neurodegenerative diseases. Given the assessment of the distribution, metabolism, excretion, and toxicity information that is already available on most neuroprotective naturopathic compounds such as TMP, it would not take much preclinical data to justify bringing such therapeutic compounds to clinical trials in humans
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