Variants of endothelial nitric oxide synthase gene are associated with components of metabolic syndrome in an Arab population

Genetics plays a crucial role in the development of metabolic syndrome (MetS). Here we examined the association between endothelial nitric oxide synthase (eNOS) gene polymorphisms and MetS in a Saudi Arabian cohort to extend the understanding of the genetic basis of MetS in diverse ethnic populations. Anthropometric, clinical and biochemical parameters as well as genotyping for 894G>T, -786T>C variants of eNOS gene by PCR-RFLP and 4a/b by direct PCR were performed in 886 Saudi Arabians (477 MetS and 409 Non-MetS). The genotype distribution (TT, p=0.001; TC, p=0.001; TC+CC, p=0.001) and allele (T, p=0.007; C, p=0.007) frequency of the -786T>C SNP were significantly different between Non-MetS and MetS subjects which remained significant after Bonferroni correction. Moreover: 1) the GT and GT+TT genotypes of the 894G>T SNP were associated with elevated blood pressure (p=0.017, and p=0.022, respectively); 2) the ab variant of 4a/b polymorphism was associated with decreased HDL levels (p= 0.044); and 3) the TC+CC genotype and C allele of the -786T>C SNP were associated with increased fasting glucose levels (p=0.039, and p=0.028, respectively). Also, G-a-C was identified as the risk haplotype for MetS susceptibility (p=0.034). The results suggest a significant association of 894G>T, 4a/b and -786T>C polymorphisms with MetS and its components is present in an Arab population. A genetic predisposition to develop abnormal metabolic phenotypes, consistent with an increased prevalence of metabolic phenotypes can be detected in this ethnic group.     

Effect of nickel ion doping in MnO2/reduced graphene oxide nanocomposites for lithium adsorption and recovery from aqueous media

Novel and effective reduced graphene oxide–nickel (Ni) doped manganese oxide (RGO/Ni-MnO₂) adsorbents were fabricated via a hydrothermal approach. The reduction of graphite to graphene oxide (GO), formation of α-MnO₂, and decoration of Ni-MnO₂ onto the surface of reduced graphene oxide (RGO) were independently carried out by a hydrothermal technique. The physical and morphological properties of the as-synthesized adsorbents were analyzed. Batch adsorption experiments were performed to identify the lithium uptake capacities of adsorbents. The optimized parameters for Li⁺ adsorption investigated were pH = 12, dose loading = 0.1 g, Li⁺ initial concentration = 50 mg L⁻¹, in 10 h at 25 °C. It is noticeable that the highest adsorption of Li⁺ at optimized parameters are in the following order: RGO/Ni3-MnO₂ (63 mg g⁻¹) > RGO/Ni2-MnO₂ (56 mg g⁻¹) > RGO/Ni1-MnO₂ (52 mg g⁻¹). A Kinetic study revealed that the experimental data were best designated pseudo-second order for each adsorbent. Li⁺ desorption experiments were performed using HCl as an extracting agent. Furthermore, all adsorbents exhibit efficient regeneration ability and to some extent satisfying selectivity for Li⁺ recovery. Briefly, it can be concluded that among the fabricated adsorbents, the RGO/Ni3-MnO₂ exhibited the greatest potential for Li⁺ uptake from aqueous solutions as compared to others.

Novel and effective reduced graphene oxide–nickel (Ni) doped manganese oxide (RGO/Ni-MnO₂) adsorbents were fabricated via a hydrothermal approach for lithium adsorption and recovery from aqueous media.     

Bi-doping improves the magnetic properties of zinc oxide nanowires

Room-temperature ferromagnetism in the large and direct bandgap diluted magnetic semiconductor zinc oxide (ZnO) is attributed to the intrinsic defects and p-orbital–p-orbital (p–p) coupling interaction. However, due to oxidation, the ferromagnetism induced by defects is unstable. In the present work, the solution process synthesis route was utilized to grow pristine and bismuth-doped, highly crystalline ZnO nanowire (ZnO NW)-based samples. The FE-SEM images showed that the grown ZnO NWs have a preferred orientation along the c-axis in the (001) direction due to the anisotropic crystal nature of ZnO. X-ray photoelectron spectroscopy (XPS) confirmed the presence of Bi, and at a higher doping content, the bismuth oxide phase appeared. The XRD patterns showed the wurtzite crystal structure, and the large intensity of the (002) peak suggests that most of the reflection was from the top hexagonal face of the NWs, and thus, the wires are predominantly aligned along the c-axis. The TEM analysis further confirmed the crystal growth direction along the (001) direction. The UV-Visible absorption and PL measurements also showed a decrease in the bandgap with an increase in doping concentration, which may be associated with the sp–d exchange interaction between the localized d-electrons and band electrons of the Bi ions. Bi-doping tended to increase the PL intensity in the visible region. The magnetic properties measured by SQUID at 4 and 300 K showed ferromagnetic behaviour for both the pristine and Bi-doped samples. However, the saturation magnetization for the Bi-doped samples was higher compared to that of the pristine ZnO samples until the threshold doping value. The obtained results demonstrated that Bi-doping can be used to tune both the optical and magnetic properties of ZnO NWs, hence paving the way for future spintronics and spin-polarized optoelectronics applications.

Room-temperature ferromagnetism in the large and direct bandgap diluted magnetic semiconductor zinc oxide (ZnO) is attributed to the intrinsic defects and p-orbital–p-orbital (p–p) coupling interaction.     

Randomized Trial of Empagliflozin in Nondiabetic Patients With Heart Failure and Reduced Ejection Fraction

BackgroundLarge clinical trials established the benefits of sodium-glucose cotransporter 2 inhibitors in patients with diabetes and with heart failure with reduced ejection fraction (HFrEF). The early and significant improvement in clinical outcomes is likely explained by effects beyond a reduction in hyperglycemia.ObjectivesThe purpose of this study was to assess the effect of empagliflozin on left ventricular (LV) function and volumes, functional capacity, and quality of life (QoL) in nondiabetic HFrEF patients.MethodsIn this double-blind, placebo-controlled trial, nondiabetic HFrEF patients (n = 84) were randomized to empagliflozin 10 mg daily or placebo for 6 months. The primary endpoint was change in LV end-diastolic and -systolic volume assessed by cardiac magnetic resonance. Secondary endpoints included changes in LV mass, LV ejection fraction, peak oxygen consumption in the cardiopulmonary exercise test, 6-min walk test, and quality of life.ResultsEmpagliflozin was associated with a significant reduction of LV end-diastolic volume (?25.1 ± 26.0 ml vs. ?1.5 ± 25.4 ml for empagliflozin vs. placebo, respectively; p < 0.001) and LV end-systolic volume (?26.6 ± 20.5 ml vs. ?0.5 ± 21.9 ml for empagliflozin vs. placebo; p < 0.001). Empagliflozin was associated with reductions in LV mass (?17.8 ± 31.9 g vs. 4.1 ± 13.4 g, for empagliflozin vs. placebo, respectively; p < 0.001) and LV sphericity, and improvements in LV ejection fraction (6.0 ± 4.2 vs. ?0.1 ± 3.9; p < 0.001). Patients who received empagliflozin had significant improvements in peak O₂ consumption (1.1 ± 2.6 ml/min/kg vs. ?0.5 ± 1.9 ml/min/kg for empagliflozin vs. placebo, respectively; p = 0.017), oxygen uptake efficiency slope (111 ± 267 vs. ?145 ± 318; p < 0.001), as well as in 6-min walk test (81 ± 64 m vs. ?35 ± 68 m; p < 0.001) and quality of life (Kansas City Cardiomyopathy Questionnaire-12: 21 ± 18 vs. 2 ± 15; p < 0.001).ConclusionsEmpagliflozin administration to nondiabetic HFrEF patients significantly improves LV volumes, LV mass, LV systolic function, functional capacity, and quality of life when compared with placebo. Our observations strongly support a role for sodium-glucose cotransporter 2 inhibitors in the treatment of HFrEF patients independently of their glycemic status. (Are the “Cardiac Benefits” of Empagliflozin Independent of Its Hypoglycemic Activity? [ATRU-4] [EMPA-TROPISM]; NCT03485222)