Abstract
Background
The role of vitamin D status in COVID-19 patients is a matter of debate.
Objectives
To assess serum 25-hydroxyvitamin D (25OHD) levels in hospitalized patients with COVID-19 and ...to analyze the possible influence of vitamin D status on disease severity.
Methods
Retrospective case–control study of 216 COVID-19 patients and 197 population-based controls. Serum 25OHD levels were measured in both groups. The association of serum 25OHD levels with COVID-19 severity (admission to the intensive care unit, requirements for mechanical ventilation, or mortality) was also evaluated.
Results
Of the 216 patients, 19 were on vitamin D supplements and were analyzed separately. In COVID-19 patients, mean ± standard deviation 25OHD levels were 13.8 ± 7.2 ng/mL, compared with 20.9 ± 7.4 ng/mL in controls (P < .0001). 25OHD values were lower in men than in women. Vitamin D deficiency was found in 82.2% of COVID-19 cases and 47.2% of population-based controls (P < .0001). 25OHD inversely correlates with serum ferritin (P = .013) and D-dimer levels (P = .027). Vitamin D-deficient COVID-19 patients had a greater prevalence of hypertension and cardiovascular diseases, raised serum ferritin and troponin levels, as well as a longer length of hospital stay than those with serum 25OHD levels ≥20 ng/mL. No causal relationship was found between vitamin D deficiency and COVID-19 severity as a combined endpoint or as its separate components.
Conclusions
25OHD levels are lower in hospitalized COVID-19 patients than in population-based controls and these patients had a higher prevalence of deficiency. We did not find any relationship between vitamin D concentrations or vitamin deficiency and the severity of the disease.
The present work investigates the quality and the chemical effects of dehydration, using a novel dehydration system based on an electromagnetic induction and low pressures technique, comparing it ...with the thermo-solar drying system. High oleic sunflower seeds, which are an important oil seed crop, were used due to the fact that they have a special place in the food industry. The seed samples were exposed to electromagnetic induction and low pressures by 0.5 and 1 h, then several chemical characterizations were carried out, in the electrophoresis study, it was found that most proteins in the hull were degraded or denatured, some of them were lost during the time in the thermosolar dryer while in kernel keeps 94.9% of the concentration in control proteins. Otherwise, the electromagnetic induction dryer did not lose the most of proteins in the kernel keeping 99.1% in 0.5 h and 98.4% in 1 h, just degrading its concentration. Germination viability results did not show changes after 0.5 h in the electromagnetic fields, but they decreased in 1 h from 66 to 40% until the thermosolar method fell to 24% in 4 h, both analysis results change proportionally with the treatment time and moisture content and the amount of the oxygen.
Polymer composites of polylactic acid (PLA) reinforced with rachis obtained from chicken feathers (0.5-1.0 wt %, 5-10 wt%) were developed by extrusion and additive manufacturing. Rachis was ...incorporated into the polymer after milling, and it was also milled and modified with sodium hydroxide (NaOH). Thermomechanical properties evaluated by dynamical mechanical analysis revealed significant increments with treated ground rachis at 1 wt%, which produced the greatest increase in E´ with respect to PLA (195%). The scanning electron microscopy images show a clear difference between the fracture surface of the compounds obtained by 3D printing according to the type and concentration of reinforcement used. In addition, the 3D printing composites show different thermal conductivities than PLA with the addition of keratin. Thus, natural composites obtained by 3D printing technology with very low concentrations of keratin show significant changes in thermal and thermomechanical properties of PLA matrix.
•We describe a detailed design methodology for ORC radial turbo expanders.•Toluene is selected as the working fluid for diesel engine waste energy recovery.•A first turbine of 15.5kW is designed but ...yields too small inlet blade heights.•A second turbine for minimum power generates 34.1kW with 51.5% efficiency.•A third turbine for maximum efficiency produces 45.6kW at 56.1% efficiency.
Future vehicles for clean transport will require new powertrain technologies to further reduce CO2 emissions. Mobile organic Rankine cycle systems target the recovery of waste heat in internal combustion engines, with the exhaust system identified as a prime source. This article presents a design methodology and working fluid selection for radial turbo expanders in a heavy-duty off-road diesel engine application. Siloxanes and Toluene are explored as the candidate working fluids, with the latter identified as the preferred option, before describing three radial turbine designs in detail. A small 15.5kW turbine design leads to impractical blade geometry, but a medium 34.1kW turbine, designed for minimum power, is predicted to achieve an isentropic efficiency of 51.5% at a rotational speed of 91.7kmin-1. A similar 45.6kW turbine designed for maximum efficiency yields 56.1% at 71.5kmin-1. This emphasizes the main design trade-off – efficiency decreases and rotational speed increases as the power requirement falls – but shows reasonable radial turbine efficiencies and thus practical turbo expanders for mobile organic Rankine cycle applications are realizable, even considering the compromised flow geometry and high speeds imposed at such small scales.
Jatropha neopauciflora Pax is an endemic species to Mexico, and its latex is used in traditional medicine to treat mouth infections when there are loose teeth and to heal wounds. In this research, we ...evaluated the antimicrobial activity, wound healing efficacy and chemical characterization of J. neopauciflora latex in a murine model.
The antibacterial activity was determined using Gram positive and negative strains, the antifungal activity was determined using yeast and filamentous fungi, and the wound healing efficacy of the latex was determined using the tensiometric method. The anti-inflammatory activity was evaluated using the plantar oedema model in rats, administering the latex orally and topically. Cytotoxic activity was determined in vitro in two different cell lines. Antioxidant capacity, total phenolics, total flavonoids, reducing carbohydrates and latex proteins were quantified. The latex analysis was performed by High Performance Liquid Chromatography (HPLC). Finally, molecular exclusion chromatography was performed.
The latex demonstrated antibacterial activity. The most sensitive strains were Gram positive bacteria, particularly S. aureus (MIC=2mg/mL), and the latex had bacteriostatic activity. The latex did not show antifungal activity. The latex demonstrated a wound-healing efficacy, even the positive control (Recoveron). The orally administered latex demonstrated the best anti-inflammatory activity and was not toxic to either of the 2 cell lines. The latex had a high antioxidant capacity (SA50=5.4µg/mL), directly related to the total phenolic (6.9mg GAE/mL) and flavonoid (12.53µg QE/mL) concentration. The carbohydrate concentration was 18.52µg/mL, and fructose was the most abundantly expressed carbohydrate in the latex (14.63µg/mL, 79.03%). Additionally, the latex contained proteins (7.62µg/mL) in its chemical constitution. As secondary metabolites, the HPLC analysis indicated the presence of phenols and flavonoids.
The J. neopauciflora latex promotes the wound healing process by avoiding microorganism infections, inhibiting inflammation and acting as an antioxidant.
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An alternative method called pulsed-DC powder-pack boriding process (PDCPB) is presented in this study. The main components of the PDCPB consisted of a metal box containing the specimen embedded in a ...powder mixture, and placed between two electrodes, which were connected to a DC power supply, and a programmable electronic control device producing the polarity changes during the process. A set of boriding conditions were carried out on the surfaces of AISI 316 L stainless steel and Inconel 718 superalloy using a constant current input of 5 A with polarity inversion cycles of 10 s. After the PDCPB, the boride layers were characterized by optical microscopy, X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy.
The growth kinetics of the boride layers was established using a diffusion model that considered the mass balance equations at the growth interfaces, in which the boron diffusion coefficients in the layers were expressed as a function of the boriding temperatures to estimate the boron activation energies in the borided materials. The change of polarity in the electrodes allowed a uniform flux of boron during the process, obtaining similar layer thicknesses on the surfaces of the material exposed to the pulsed-DC field. Finally, the results showed that the growth rate of the layers was increased by the effect of the pulsed-DC field, whilst the boron activation energies, in the borided materials, decreased drastically compared to those obtained for the conventional powder-pack boriding process.
•A novel method denominated pulsed-DC powder-pack boriding is presented in this work.•Uniform boron fluxes were produced on the surfaces exposed to pulsed-DC field.•Pulsed-DC field developed similar layer thicknesses at the material surface.•Pulsed-DC field increased the growth kinetics of boride layer in treated materials.
Doxycycline (Doxy) is an antibiotic, which has exhibited anti-inflammatory activity and glucose metabolism improvement. The present study was proposed to evaluate its effects on glucose metabolism ...and other associated processes, such as lipemia and adipogenesis, as well as, to evaluate its effects on the liver, pancreas, and aorta in subjects fed with an occidental high-fat diet (HFD). The trial followed three groups of BALB/c mice for 6 months: (1) Standard diet (SD); (2) HFD-placebo (saline solution); and (3) HFD-Doxy (10 mg/kg/day). Intrahepatic fat accumulation (steatohepatosis) and the epididymal fat pad, as well as the hepatic inflammatory infiltrate and ALT serum levels were higher in both groups with the HFD (with/without doxycycline) in comparison with the SD group. The thickness of the aorta (preclinic atherosclerosis) was significantly elevated in the HFD group with respect to the HFD + Doxy and SD group, these two being similar groups to each other. The HFD-Doxy group had pancreatic morphological parameters very similar to those of the SD group; on the contrary, the HFD group reduced the number of pancreatic islets and the number of β cells per mm
, in addition to losing large islets. The index of β cell function (∆Insulin0-30/∆Glucose0-30 ratio) was significantly higher in the HFD + Doxy group, compared to the rest of the groups.
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•PLA, chitosan and keratin can be used to make scaffolds by extrusion and 3D printing.•Particles as reinforcement have a better performance compared to fibers.•Chitosan and keratin ...promote important increase of cell growth in a PLA matrix.•Alpha and beta keratin structures have a similar performance in cell growth.•3D printing proved be able to make composite scaffolds applied in tissue engineering.
We have used polylactic acid (PLA), keratin and chitosan to manufacture 3D printable polymer composite scaffolds. The effect of two different keratin reinforcements types, i.e., keratin in fibers and particles form are studied, and the size reduction in chitosan material. Specifically, the behaviour of two different keratin configurations i.e., α-helix (from hair) and predominantly β-sheet (from chicken feathers) are used. The 3D printed composites are analysed by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and dynamic mechanical analysis (DMA). Finally, cytotoxicity assays and swelling tests are performed to analyse the possible application in tissue engineering. Different keratin and chitosan sizes and shapes analyses revealed that morphology is of paramount importance for thermomechanical and cellular growth. Achieving the best results with particle-like shaped rather than with fibre-like, and chitosan materials before of size reduction. For example, the storage modulus increases around 80–85% and the cell growth results increase approximately 81–85%. In addition, swelling tests in distilled water and simulated body fluid (SBF) reveal, particle size is also important to avoid excessive swelling in the composites. Thus, the results presented evidence about the impact of reinforcement size in the studied properties the feasibility of developing biodegradable polymer composites of completely natural sources and their application for bio-scaffolds supported by the versatility of additive manufacturing.
Bladder cancer (BC) is one of the top 10 most common tumours worldwide; however, no molecular markers are currently available for tumour management and follow-up. BC could benefit from molecular ...biomarkers in environmental disease, which provide mechanistic understanding of individual susceptibility to exposure-related cancers and allow characterizing genetic alterations in the molecular pathway for malignancy. This case-control study performed a molecular analysis in 99 BC and 125 controls. Buccal swabs were collected to assess SNPs in eleven genes coding for xenobiotic detoxification enzymes, cellular antioxidant defences, and hormone synthesis and signalling (NAT2 (rs1801280), GPX1 (rs1050450 and rs17650792), TXNRD1 (rs7310505), PRDX3 (rs3740562), PON1 (rs662), SOD1 (rs10432782), SOD2 (rs4880), CAT (rs1001179), CYP17A1 (rs743572) and ESR1 (rs746432)). A structured questionnaire was administered to study participants to assess environmental and dietary chemical exposures. Several miRNAs associated with BC and detoxification/antioxidant pathways were analysed in a subsample of the study population, including miR-93-5p, miR-221-3p, miR-126, miR-27a-3p, miR-193b, and miR-193a-5p. Levels of selected environmental pollutants (polycyclic aromatic hydrocarbons and endocrine disrupting chemicals) were determined in urine from a subsample of BC cases and controls. We found that CYP17A1, CAT, SOD1, ESR1, PON1, and GPX1 (rs17650792) were associated with BC risk. Furthermore, exposure to smoke and/or dust, and alcohol intake were identified as risk factors for BC. Increased urinary levels of benzoapyrene and bisphenol A were observed in BC patients relative to controls, along with an increased expression of miR-193b, miR-27a and miR-93-5p in BC. Nevertheless, further studies with a larger sample size are warranted to confirm these exploratory results. This study also shows that the combination of genetic markers (PON1 and CYP17A1) and miRNA (miR-221-3p and miR-93-5p) open a new scenario in the use of non-invasive biomarkers in the stratification of BC to guide personalized medicine, which is extremely urged in the current clinical setting.
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•Genetic variants of CYP17A1, CAT and SOD1 were associated with bladder cancer (BC).•A different set of genetic variants studied were associated with BC aggressiveness.•Exposure to smoke, dust and alcohol intake were risk factors associated with BC.•Urine levels of BaP and BPA were associated with bladder cancer.•Higher expression of miRNA-93-5p, miRNA-193b and miRNA-27a increased BC risk.
A
bstract
A model-independent expression for the Dalitz plot of the semileptonic decays of a neutral kaon
K
μ
3
0
, including radiative corrections to order
O
(
α/π
)(
q/M
1
), where
q
is the ...four-momentum transfer and
M
1
is the mass of the decaying kaon, is presented. In this paper the emitted muon is considered to be polarized so the analysis is centered on numerically evaluating the radiative corrections to the longitudinal, transverse, and normal polarization muon components. The model dependence of radiative corrections is kept in general form within this approximation, which is useful for model-independent experimental analyses. The final expressions, with the triple integration of the bremsstrahlung photon variables are ready to be evaluated numerically, they are free of the infrared divergence or ultraviolet cutoff. The radiative corrections to the components of the muon polarization are found to be very small compared to their respective uncorrected values.
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