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Primary ovarian insufficiency (POI) is a clinical syndrome of ovarian dysfunction characterized by premature exhaustion of primordial follicles. POI causes infertility, severe daily life disturbances and long-term health risks. However, the underlying mechanism remains largely unknown. We previously identified a Basonuclin 1 (BNC1) mutation from a large Chinese POI pedigree and found that mice with targeted Bnc1 mutation exhibit symptoms of POI. In this study, we found that BNC1 plays key roles in ovarian reserve and maintaining lipid metabolism and redox homeostasis in oocytes during follicle development. Deficiency of BNC1 results in premature follicular activation and excessive follicular atresia. Mechanistically, BNC1 deficiency triggers oocyte ferroptosis via the NF2-YAP pathway. We demonstrated that pharmacologic inhibition of YAP signaling or ferroptosis significantly rescues Bnc1 mutation-induced POI. These findings uncover a pathologic mechanism of POI based on BNC1 deficiency and suggest YAP and ferroptosis inhibitors as potential therapeutic targets for POI. Primary ovarian insufficiency (POI) is a clinical syndrome of ovarian dysfunction that results in infertility. Here they show that BCN1 mutation results in premature ovarian follicle activation and atresia through dysregulation of ferroptosis. [ABSTRACT FROM AUTHOR]

Renewable energy-based electrocatalytic hydrogenation of acetylene to ethylene (E-HAE) under mild conditions is an attractive substitution to the conventional energy-intensive industrial process, but is challenging due to its low Faradaic efficiency caused by competitive hydrogen evolution reaction. Herein, we report a highly efficient and selective E-HAE process at room temperature and ambient pressure over the Cu catalyst. A high Faradaic efficiency of 83.2% for ethylene with a current density of 29 mA cm−2 is reached at −0.6 V vs. the reversible hydrogen electrode. In-situ spectroscopic characterizations combined with first-principles calculations reveal that electron transfer from the Cu surface to adsorbed acetylene induces preferential adsorption and hydrogenation of the acetylene over hydrogen formation, thus enabling a highly selective E-HAE process through the electron-coupled proton transfer mechanism. This work presents a feasible route for high-efficiency ethylene production from E-HAE. This work achieves highly active and selective electrocatalytic hydrogenation of acetylene to ethylene (HAE) under mild conditions over Cu catalyst to replace the classic thermocatalytic HAE route requiring harsh conditions and costly H2. [ABSTRACT FROM AUTHOR]

Aristolochic acids (AAs) are a family of natural compounds with AA I and AA II being known carcinogens, whose bioactivation causes DNA adducts formation. However, other congeners have rarely been investigated. This study aimed to investigate genotoxicity of AA IVa, which differs from AA I by a hydroxyl group, abundant in Aristolochiaceae plants. AA IVa reacted with 2'-deoxyadenosine (dA) and 2'-deoxyguanosine (dG) to form three dA and five dG adducts as identified by high-resolution mass spectrometry, among which two dA and three dG adducts were detected in reactions of AA IVa with calf thymus DNA (CT DNA). However, no DNA adducts were detected in the kidney, liver, and forestomach of orally dosed mice at 40 mg/kg/day for 2 days, and bone marrow micronucleus assay also yielded negative results. Pharmacokinetic analyses of metabolites in plasma indicated that AA IVa was mainly O-demethylated to produce a metabolite with two hydroxyl groups, probably facilitating its excretion. Meanwhile, no reduced metabolites were detected. The competitive reaction of AA I and AA IVa with CT DNA, with adducts levels varying with pH of reaction revealed that AA IVa was significantly less reactive than AA I, probably by hydroxyl deprotonation of AA IVa, which was explained by theoretical calculations for reaction barriers, energy levels of the molecular orbits, and charges at the reaction sites. In brief, although it could form DNA adducts in vitro, AA IVa was non-genotoxic in vivo, which was attributed to its low reactivity and biotransformation into an easily excreted metabolite rather than bioactivation. [ABSTRACT FROM AUTHOR]

The thermoelectric properties of Y-doped (1000 ppm, 2000 ppm, 3000 ppm) MgSi fabricated using field-activated pressure-assisted synthesis (FAPAS) have been characterized using measurements of electrical resistivity ( ρ), Seebeck coefficient ( S), and thermal conductivity ( κ) at temperatures ranging from 285 K to 810 K. The Y-doped MgSi samples were n-type in the measured temperature range. A first-principles calculation revealed that the Y atoms were expected to be primarily located at Mg sites. In sample doped with 2000 ppm Y, which exhibited the best electrical and thermal conductivity, the absolute value of the Seebeck coefficient increased in the temperature range of 320 K to 680 K, being higher than that of undoped MgSi. Moreover, this sample exhibited a higher level of electrical conductivity and a higher power factor. In addition, introduction of Y decreased the thermal conductivity appreciably, indicating that Y dopants are favorable for improving the properties of MgSi. [ABSTRACT FROM AUTHOR]

Field-activated pressure-assisted sintering (FAPAS) was applied to sinter BiSbTe thermoelectric materials under different conditions, including no-current sintering (NCS), low-density current sintering (LCS), and high-density current sintering (HCS). The effect of the current density on the final thermoelectric performance of the products was investigated. Applying a higher-density electric current and shorter dwell time can improve the thermoelectric performance of the sample by increasing its electric conductivity and decreasing its thermal conductivity. The maximum figure of merit ZT values of the NCS, LCS, and HCS samples were 0.46, 0.48, and 0.57, respectively. Therefore, applying a high-density electric current in the sintering process may be an effective way to obtain BiSbTe thermoelectric material with high ZT value. [ABSTRACT FROM AUTHOR]

(TiC-TiB)Ni composite ceramics was prepared by field-activated pressure-assisted synthesis (FAPAS) starting from Ti, BC and Ni powders. The friction and wear properties of ceramics were evaluated by sliding against GCr15 steel from room temperature to 400 °C in air. The worn morphology and phase component of the worn surfaces were analyzed by means of SEM and XRD. It is revealed that TiC and TiB particulates are fine and homogeneously distributed in the nickel matrix. The synthesized composite ceramics has lower coefficient of friction and wear rate at elevated temperature. Wear mechanisms of (TiC-TiB)Ni ceramics depend mainly upon testing conditions. The oxide films of FeO, TiO and BO formed during friction process play an important role in lubrication. Oxidized products greatly reduce the coefficient of friction of (TiC-TiB)Ni ceramics at 400 °C or above. [ABSTRACT FROM AUTHOR]

Field-activated pressure-assisted synthesis (FAPAS) was used to prepare TiB-TiC-Ni/TiAl/Ti functionally gradient materials. Interfacial microstructure and bonding strength of materials were mainly investigated. The microstructure, phase composition and distribution of elements of interface were analyzed by SEM, XRD and EDS. The shear strength and micro-hardness were also tested. The results show that the particles of TiB-TiC composite ceramics prepared by FAPAS are fine and homogeneous disperse. Closely metallurgical bonding forms between layers by mutual diffusion of different elements across the interfaces. The maximum shear strength of joint reaches 85.878 MPa and the fracture occurs at the interface of cermet and TiAl. The micro-hardness of the sample changes gradually from titanium substrate to the cermet with a maximum hardness of 2760HV in the cermet. [ABSTRACT FROM AUTHOR]

Traditional water-gas shift reaction provides one primary route for industrial production of clean-energy hydrogen. However, this process operates at high temperatures and pressures, and requires additional separation of H2 from products containing CO2, CH4 and residual CO. Herein, we report a room-temperature electrochemical water-gas shift process for direct production of high purity hydrogen (over 99.99%) with a faradaic efficiency of approximately 100%. Through rational design of anode structure to facilitate CO diffusion and PtCu catalyst to optimize CO adsorption, the anodic onset potential is lowered to almost 0 volts versus the reversible hydrogen electrode at room temperature and atmospheric pressure. The optimized PtCu catalyst achieves a current density of 70.0 mA cm−2 at 0.6 volts which is over 12 times that of commercial Pt/C (40 wt.%) catalyst, and remains stable for even more than 475 h. This study opens a new and promising route of producing high purity hydrogen. Traditional water-gas shift reaction process is hindered by harsh reaction conditions and extra steps for hydrogen separation and purification. Here, the authors report a room temperature electrochemical water-gas shift process for direct production of high purity hydrogen with a faradaic efficiency of approximately 100%. [ABSTRACT FROM AUTHOR]