Adults with obesity and type 2 diabetes mellitus (T2DM) related to obesity are at increased risk of heart failure with preserved ejection fraction (HFpEF). Whether left ventricular (LV) diastolic ...function abnormalities related to obesity and T2DM start in adolescence and early adulthood is unknown. We non-invasively evaluated the differences seen in LV diastolic and left atrial (LA) function in adolescents and young adults with obesity and T2DM.
We analyzed echocardiographic measures of LV diastolic function in patients with structurally normal hearts which were divided into 3 groups (normal weight, obese, and T2DM). Spectral and tissue Doppler and 2-D speckle tracking measurements of diastolic function were obtained. Logistic regression was performed to compare the prevalence of abnormalities in diastolic function based on the worst 25th percentile for each measure to determine the prevalence of diastolic and LA function abnormalities in obese and T2DM patients.
331 teenagers and young adults (median age 22.1 years) were analyzed (101 normal weight, 114 obese, 116 T2DM). Obese and T2DM group had lower E/A and higher E/e'. Obese and T2DM patients had significantly lower atrial reservoir, conduit, and booster strain and worse reservoir and conduit strain rate compared to normal patients (p < 0.001 for all measures). All patients had normal LA volumes. On multivariable analysis, conduit strain and reservoir and conduit strain rate were independently associated with having below the 25th percentile e'. Conduit strain rate was independently associated with having below the 25th percentile for mitral E/A ratio on multivariable analysis.
Abnormal indices of LV diastolic function are detected in adolescents and young adults with obesity and T2DM. LA function and strain analysis were able to detect evidence of decreased reservoir, conduit, and booster strain in these patients although LA volume was normal. The use of LA function strain may increase our ability to detect early diastolic function abnormalities in this population.
The effect of oxygen plasma treatment on multi-walled carbon nanotubes (MWCNTs) surfaces towards controlled tuning of their electrodonor properties (gauged by the work function) was investigated ...experimentally (X-ray diffraction, Raman spectroscopy, thermogravimetry, transmission electron microscopy, X-ray photoelectron spectroscopy) and by molecular modeling (Density Functional Theory). The nanotubes were treated with oxygen plasma (0.2 mbar) at varied generator power (20–60 W) and exposure time (0.1–30 min). It was found that the work function changes nonmonotonously upon plasma treatment: after significant increase (from 4.5 eV to 5.9 eV) and passing through maximum the work function decreases and finally reaches a plateau. The experimental results supported by DFT calculations allowed to propose a molecular model explaining the changes in carbon nanotube surface induced by oxygen plasma. Two different oxygen adatom locations: out-of-plane (Csurf–Oadatom) and in-plane (Csurf–Osurf–Csurf) were identified, leading to formation of surface dipoles (formation of negative potential barrier, work function increase) and incorporation of oxygen into the carbon structure (cancellation of the potential barrier, work function decrease), respectively. The critical regions of plasma parameters for oxygen surface decoration and amorphization were identified providing guidelines for rational designing and tuning of MWCNT electrodonor properties.
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In this paper comparative studies on the structural, mechanical and corrosion properties of Nb2O5 thin film and Nb2O5+Graphene, Nb2O5+CuO and Nb2O5+CuO+Graphene composite thin films on Ti6Al4V ...titanium alloy have been investigated. The layers on which the Nb2O5 and Nb2O5+CuO were deposited by the magnetron sputtering method were crack free and exhibited good adherence to the substrate, and the surface morphology was homogeneous. The graphene transferred on to the Nb2O5 as a single layer without defects. The hardness of the Nb2O5 was approx. 4.78GPa while the Nb2O5+CuO had a hardness of 9.19GPa. The graphene coating had no effect on surface hardness but it decreased the electrochemical activity. The best corrosion resistance was displayed by the Ti6Al4V sample with an Nb2O5+Graphene thin film.
•The icorr for Nb2O5+Graphene on the surface of the Ti6Al4V decreased to 0.01μA/cm2.•Composite films caused decrease in the electrochemical activity of the Ti alloy surface.•The composite films modified the surface hardness of titanium alloy from 5.58GPa to 9.19GPa.•A graphene monolayer has no effect on Nb2O5 thin film hardness.
The purity of drinking water is an important issue of the human life quality. Water disinfection has saved millions people from the diseases spread with water. However, that procedure has a certain ...drawback due to formation of toxic organic disinfection products. Establishing the structures of these products and the mechanisms of their formation and diminishing their levels in drinking water represent an important task for chemistry and medicine, while mass spectrometry is the most efficient tool for the corresponding studies. The current review throws light upon natural and anthropogenic sources of the formation of disinfection by-products (DBPs) and the mechanisms of their formation related to the structural peculiarities and the presence of functional groups. In addition to chlorination, bromination is discussed since it is used quite often as an alternative method of disinfection, particularly, for the purification of swimming pool water. The benefits of the contemporary GC/MS and LC/MS methods for the elucidation of DBP structures and study of the mechanisms of their formation are discussed. The reactions characteristic for various functional groups and directions of transformation of certain classes of organic compounds in conditions of aqueous chlorination/bromination are also covered in the review.
Faced with sudden environmental changes, animals must either adapt to novel environments or go extinct. Thus, study of the mechanisms underlying rapid adaptation is crucial not only for the ...understanding of natural evolutionary processes but also for the understanding of human-induced evolutionary change, which is an increasingly important problem 1–8. In the present study, we demonstrate that the frequency of completely plated threespine stickleback fish (Gasterosteus aculeatus) has increased in an urban freshwater lake (Lake Washington, Seattle, Washington) within the last 40 years. This is a dramatic example of “reverse evolution,”9 because the general evolutionary trajectory is toward armor-plate reduction in freshwater sticklebacks 10. On the basis of our genetic studies and simulations, we propose that the most likely cause of reverse evolution is increased selection for the completely plated morph, which we suggest could result from higher levels of trout predation after a sudden increase in water transparency during the early 1970s. Rapid evolution was facilitated by the existence of standing allelic variation in Ectodysplasin (Eda), the gene that underlies the major plate-morph locus 11. The Lake Washington stickleback thus provides a novel example of reverse evolution, which is probably caused by a change in allele frequency at the major plate locus in response to a changing predation regime.
Postkidney transplant hyperparathyroidism is a significant problem. Vitamin D receptor agonists are known to suppress parathyroid hormone (PTH) secretion. We examined the effect of oral paricalcitol ...on posttransplant secondary hyperparathyroidism by conducting an open label randomized trial in which 100 incident kidney transplant recipients were randomized 1:1 to receive oral paricalcitol, 2 μg per day, for the first year posttransplant or no additional therapy. Serial measurements of serum PTH, calcium and bone alkaline phosphatase, 24‐h urine calcium and bone density were performed. The primary endpoint was the frequency of hyperparathyroidism 1‐year posttransplant. Eighty‐seven patients completed the trial. One‐year posttransplant, 29% of paricalcitol‐treated subjects had hyperparathyroidism compared with 63% of untreated patients (p = 0.0005). Calcium supplementation was discontinued in two control and 15 treatment patients due to mild hypercalcemia or hypercalcuria. Paricalcitol was discontinued in four patients due to hypercalcuria/hypercalcemia and in one for preference. Two subjects required decreasing the dose of paricalcitol to 1 μg daily. Hypercalcemia was asymptomatic and reversible. Incidence of acute rejection, BK nephropathy and renal function at 1 year were similar between groups. Moderate renal allograft fibrosis was reduced in treated patients. Oral paricalcitol is effective in decreasing posttransplant hyperparathyroidism and may have beneficial effects on renal allograft histology.
Paricalcitol decreases the prevalence of post‐kidney transplant hyperparathyroidism and may have beneficial effects on renal allograft histology.
Articular cartilage has a limited capacity to heal itself and thus focal defects often result in the development of osteoarthritis. Current cartilage tissue engineering strategies seek to regenerate ...injured tissue by creating scaffolds that aim to mimic the unique structure and composition of native articular cartilage. Decellularization is a novel strategy that aims to preserve the bioactive factors and 3D biophysical environment of the native extracellular matrix while removing potentially immunogenic factors. The purpose of this study was to develop a procedure that can enable decellularization and recellularization of intact articular cartilage matrix. Full-thickness porcine articular cartilage plugs were decellularized with a series of freeze-thaw cycles and 0.1% (w/v) sodium dodecyl sulfate detergent cycles. Chondroitinase ABC (ChABC) was applied before the detergent cycles to digest glycosaminoglycans in order to enhance donor chondrocyte removal and seeded cell migration. Porcine synovium-derived mesenchymal stem cells were seeded onto the decellularized cartilage scaffolds and cultured for up to 28 days. The optimized decellularization protocol removed 94% of native DNA per sample wet weight, while collagen content and alignment were preserved. Glycosaminoglycan depletion prior to the detergent cycles increased removal of nuclear material. Seeded cells infiltrated up to 100 μm into the cartilage deep zone after 28 days in culture. ChABC treatment enhances decellularization of the relatively dense, impermeable articular cartilage by reducing glycosaminoglycan content. ChABC treatment did not appear to affect cell migration during recellularization under static, in vitro culture, highlighting the need for more dynamic seeding methods.
In this paper the comparative studies on structural, mechanical and corrosion properties of Nb2O5/Ti–Al–V and graphene/Ti–Al–V alloy systems have been investigated. We show that the hardness of pure ...niobium pentoxide was ca. 8.64GPa and graphene deposited on titanium alloy surface was equal 5.63GPa. However, the graphene monolayer has no effect on surface hardness of titanium alloy and can be easily removed from the surface. On the other hand, the sample with graphene coating has much better corrosion resistance.
Our results suggest, that the use of combined layers of niobium pentoxide and graphene, in the hybrid multilayer system can greatly improve the mechanical and corrosion properties of the titanium alloy surface. Such hybrid system can be used in the future, as protection coating for Ti alloy, in biomedical application and in other applications, where Ti alloys work in an aggressive corrosive environment and in engineering applications where friction is involved.
•Corrosion properties of Nb2O5/TiAlV and graphene/TiAlV systems were investigated.•Nb2O5 thin film improves titanium alloy surface hardness from 5.64GPa to 8.64GPa.•Nb2O5 thin film improves corrosion resistance of Ti6Al4V in aggressive environment.•icorr for graphene monolayer deposited on Ti6Al4V surface decreases to 0.01μA/cm2.•Graphene monolayer caused decrease in the electrochemical activity of the Ti surface.
The best way to understand the environmental status of a certain region involves thorough non-target analysis, which will result in a list of pollutants under concern. Arkhangelsk (64° 32′ N 40° 32′ ...E, pop. ~ 344,000) is the largest city in the world to the north of the 60
th
parallel. Several industrial enterprises and the “cold finger” effect represent the major sources of air contamination in the city. Analysis of snow with comprehensive two-dimensional gas chromatography–high-resolution mass spectrometry allows detecting and quantifying the most hazardous volatile and semivolatile anthropogenic pollutants and estimating long-term air pollution. Target analysis, suspect screening, and non-target analysis of snow samples collected from ten sites within the city revealed the presence of several hundreds of organic compounds including 18 species from the US EPA list of priority pollutants. Fortunately, the levels of these compounds appeared to be much lower than the safe levels established in Russia. Phenol and dioctylphthalate could be considered as the pollutants of concern because their levels were about 20% of the safe thresholds. ChromaTOF® Tile, MetaboAnalyst software platform, and open-source software protocols were applied to process the obtained data. The obtained clusterization results of the samples were generally similar for various tools; however, each of them had certain peculiarities. Bis(2-ethylhexyl) hexanedioate, benzyl alcohol, phthalates, aniline, dinitrotoluenes, and fluoranthene showed the strongest influence on the clusterization of the studied samples. Possible sources of the major pollutants were proposed: car traffic and pulp and paper mills.
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Most parthenogenetic weevil species are postulated to have originated via hybridization, but Wolbachia has also been speculated to play a role via the induction of parthenogenesis. Here, we examine ...the molecular diversity of Wolbachia and parthenogenetic host genomes. The host species studied here, Eusomus ovulum, is known to be exclusively parthenogenetic and triploid. The E. ovulum populations that we examined had a low genetic diversity of mitochondrial (cytochrome oxidase I gene) and nuclear markers (internal transcribed spacer 2 and elongation factor 1‐α gene), and they all were infected by only single bacteria strains (genotyped for five genes according to the multilocus sequence typing system). We found significant signs of linkage disequilibrium and a lack of recombination amongst all of the examined genomes (bacteria and host), which strongly indicates a selective sweep. The lack of heterozygosity in host nuclear genes, missing bisexual populations and selective sweep between the parthenogenetic host and bacteria genomes suggest that parthenogenesis in this species could have originated as a result of infection rather than hybridization. However, the finding that highly similar Wolbachia strains are also present in other parthenogenetic weevils from the same habitat suggests the opposite scenario: bacteria may have infected the already parthenogenetic lineage and taken advantage of the host's unisexual reproduction.
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