Sex-specific association of serum dehydroepiandrosterone and its sulfate levels with osteoporosis in type 2 diabetes.

INTRODUCTION: This study is to investigate the relation between serum dehydroepiandrosterone (DHEA) and its sulfate (DHEAS) levels and the risk of osteoporosis in patients with T2DM. MATERIALS AND METHODS: This cross-sectional study involved 938 hospitalized patients with T2DM. Linear regression models were used to explore the relationship between DHEA and DHEAS and the BMD at different skeletal sites. Multinominal logistic regression models and the restricted cubic spline (RCS) were used to evaluate the associations of DHEA and DHEAS with the risks of osteopenia and/or osteoporosis. RESULTS: In postmenopausal women with T2DM, after adjustment for confounders including testosterone and estradiol, DHEA showed a significant positive correlation with lumbar spine BMD (P = 0.013). Moreover, DHEAS exhibited significant positive correlations with BMD at three skeletal sites: including femoral neck, total hip, and lumbar spine (all P < 0.05). Low DHEA and DHEAS levels were associated with increased risk of osteopenia and/or osteoporosis (all P < 0.05) and the risk of osteoporosis gradually decreased with increasing DHEAS levels (P overall = 0.018, P-nonlinear = 0.559). However, DHEA and DHEAS levels in men over the age of 50 with T2DM were not associated with any of above outcomes. CONCLUSION: In patients with T2DM, independent of testosterone and estradiol, higher DHEA and DHEAS levels are associated with higher BMD and lower risk of osteopenia/osteoporosis in postmenopausal women but not men over the age of 50.

Enhanced NH3 Synthesis from Air in a Plasma Tandem-Electrocatalysis System Using Plasma-Engraved N-Doped Defective MoS2.

We have developed a sustainable method to produce NH3 directly from air using a plasma tandem-electrocatalysis system that operates via the N2-NOx-NH3 pathway. To efficiently reduce NO2- to NH3, we propose a novel electrocatalyst consisting of defective N-doped molybdenum sulfide nanosheets on vertical graphene arrays (N-MoS2/VGs). We used a plasma engraving process to form the metallic 1T phase, N doping, and S vacancies in the electrocatalyst simultaneously. Our system exhibited a remarkable NH3 production rate of 7.3 mg h-1 cm-2 at -0.53 V vs RHE, which is almost 100 times higher than the state-of-the-art electrochemical nitrogen reduction reaction and more than double that of other hybrid systems. Moreover, a low energy consumption of only 2.4 MJ molNH3-1 was achieved in this study. Density functional theory calculations revealed that S vacancies and doped N atoms play a dominant role in the selective reduction of NO2- to NH3. This study opens up new avenues for efficient NH3 production using cascade systems.