Facet-switching of rate-determining step on copper in CO2-to-ethylene electroreduction.

Reduction of carbon dioxide (CO2) by renewable electricity to produce multicarbon chemicals, such as ethylene (C2H4), continues to be a challenge because of insufficient Faradaic efficiency, low production rates, and complex mechanistic pathways. Here, we report that the rate-determining steps (RDS) on common copper (Cu) surfaces diverge in CO2 electroreduction, leading to distinct catalytic performances. Through a combination of experimental and computational studies, we reveal that C─C bond-making is the RDS on Cu(100), whereas the protonation of *CO with adsorbed water becomes rate-limiting on Cu(111) with a higher energy barrier. On an oxide-derived Cu(100)-dominant Cu catalyst, we reach a high C2H4 Faradaic efficiency of 72%, partial current density of 359 mA cm-2, and long-term stability exceeding 100 h at 500 mA cm-2, greatly outperforming its Cu(111)-rich counterpart. We further demonstrate constant C2H4 selectivity of >60% over 70 h in a membrane electrode assembly electrolyzer with a full-cell energy efficiency of 23.4%.

Meta-Analysis of Efficacy of Platelet-Rich Plasma Combined with Minoxidil for Androgenetic Alopecia.

BACKGROUND: Androgenetic alopecia (AGA) is a prevalent type of hair loss that impacts individuals of both genders. Platelet-rich plasma (PRP) and minoxidil have been employed as therapeutic interventions for AGA, yet the efficacy of their concurrent use remains ambiguous. OBJECTIVE: To perform a comprehensive review and meta-analysis aimed at evaluating the effectiveness of platelet-rich plasma (PRP) in combination with minoxidil for the treatment of androgenetic alopecia (AGA). METHODS: We conducted a comprehensive search of the databases PubMed, Embase, Web of Science, and Cochrane Library, encompassing their complete records up until December 2023. Eligible studies were randomized controlled trials that compared the combination of PRP and minoxidil with minoxidil or PRP alone in patients with AGA. The primary outcome measure was the change in hair growth as assessed by the hair density or hair thickness. Secondary outcome measures included patient satisfaction, and global photographic assessment. RESULTS: A total of 6 studies involving 343 participants were included in this meta-analysis. The results showed that PRP combined with minoxidil significantly improved hair growth compared to minoxidil or PRP alone. The pooled analysis demonstrated a significant increase in hair density (weighted mean difference [WMD] = 9.14; 95% confidence interval [CI]: 6.57-11.70) and hair diameter (WMD = 4.72; 95% CI 3.21-6.23) in the PRP combined with minoxidil group. Moreover, patients receiving PRP combined with minoxidil reported higher satisfaction rates compared to those using minoxidil or PRP alone. CONCLUSIONS: This meta-analysis suggests that PRP combined with minoxidil is an effective treatment for AGA, providing significant improvement in hair growth and patient satisfaction. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Unraveling Stoichiometry Effect in Nickel-Tungsten Alloys for Efficient Hydrogen Oxidation Catalysis in Alkaline Electrolytes.

Anion-exchange membrane fuel cells provide the possibility to use platinum group metal-free catalysts, but the anodic hydrogen oxidation reaction (HOR) suffers from sluggish kinetics and its source is still debated. Here, over nickel-tungsten (Ni-W) alloy catalysts, we show that the Ni : W ratio greatly governs the HOR performance in alkaline electrolyte. Experimental and theoretical studies unravel that alloying with W can tune the unpaired electrons in Ni, tailoring the potential of zero charge and the catalytic surface to favor hydroxyl adsorption (OHad). The OHad species coordinately interact with potassium (K+) ions, which break the K+ solvation sheath to leave free water molecules, yielding an improved connectivity of hydrogen-bond networks. Consequently, the optimal Ni17W3 alloy exhibits alkaline HOR activity superior to the state-of-the-art platinum on carbon (Pt/C) catalyst and operates steadily with negligible decay after 10,000 cycles. Our findings offer new understandings of alloyed HOR catalysts and will guide rational design of next-generation catalysts for fuel cells.

Efficient NH3-Tolerant Nickel-Based Hydrogen Oxidation Catalyst for Anion Exchange Membrane Fuel Cells.

Converting hydrogen chemical energy into electrical energy by fuel cells offers high efficiencies and environmental advantages, but ultrapure hydrogen (over 99.97%) is required; otherwise, the electrode catalysts, typically platinum on carbon (Pt/C), will be poisoned by impurity gases such as ammonia (NH3). Here we demonstrate remarkable NH3 resistivity over a nickel-molybdenum alloy (MoNi4) modulated by chromium (Cr) dopants. The resultant Cr-MoNi4 exhibits high activity toward alkaline hydrogen oxidation and can undergo 10,000 cycles without apparent activity decay in the presence of 2 ppm of NH3. Furthermore, a fuel cell assembled with this catalyst retains 95% of the initial peak power density even when NH3 (10 ppm)/H2 was fed, whereas the power output reduces to 61% of the initial value for the Pt/C catalyst. Experimental and theoretical studies reveal that the Cr modifier not only creates electron-rich states that restrain lone-pair electron donation but also downshifts the d-band center to suppress d-electron back-donation, synergistically weakening NH3 adsorption.

Solubility, Crystallization, and Characterization of Cytidine Sulfate.

Cytidine is an important kind of nucleoside that can be applied to drug development and food industry. Cytidine sulfate is one of its popular forms, which is promising as a medicinal intermediate, especially in antiviral and antitumor drugs. Product refining is the key point of industrial development, and crystallization is a significant way of refining. In this work, the solubility of cytidine sulfate in pure water from 278.15 to 328.15 K and in water-ethanol binary solvents at 298.15 K was measured by the UV spectroscopic method. The solubility data were correlated with temperature and solvent composition using the modified Apelblat, van't Hoff, and CNIBS/R-K equations. On this basis, we investigated and compared three crystallization processes, and the coupling method was developed to prepare crystals with a large particle size, concentrated distribution, and high yield and packing density. In addition, the structure and stability of the products were characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and dynamic vapor sorption analysis. It was found that cytidine sulfate has only one crystal form in our research process, and the product of coupling crystallization is stable and favorable for industrial development.

Speciation, bioaccessibility and human health risk assessment of chromium in solid wastes from an ultra-low emission coal-fired power plant, China.

Chromium (Cr) in solid wastes from ultra-low emission (ULE) coal-fired power plants (CFPPs) could engender adverse effects on environment and human health. Hence, solid waste samples containing bottom ash, fly ash, gypsum and sludge were collected from a typical ULE CFPP in China to study the distribution, speciation, bioaccessibility and human health risk of Cr. The results showed that Cr was depleted in gypsum, whereas significantly enriched in bottom ash, fly ash and sludge comparing with feed coal. The ratios of Cr(VI) to total Cr in solid wastes were relatively low, but the increase of flow fractions in Cr chemical binding forms implied the deterioration of environmental stability. Based on the in vitro simulated digestion methods of solubility bioavailability research consortium (SBRC) and physiologically based extraction test (PBET), the bioaccessibility of Cr in the gastric and intestinal phases reached the highest values in either gypsum or sludge. After incorporating bioaccessibility in human health risk assessment, the carcinogenic risk (CR) within acceptable limits of Cr in solid wastes to adults and children was concluded, with the non-carcinogenic hazard quotient (HQ) was all within the safety threshold. The Monte Carlo model was applied to evaluate the uncertainty analysis of human health risk assessment at 5% and 95% confidence interval, and the fitting results were consistent with the calculation results of the carcinogenic and non-carcinogenic risk for adults and children. This study is expected to provide insights for the integration of bioaccessibility into the health risk assessment of Cr in solid wastes from ULE CFPPs, thus is conducive to the disposal of solid wastes and human health protection.

Screening of antibacterial compounds with novel structure from the FDA approved drugs using machine learning methods.

Bacterial infection is one of the most important factors affecting the human life span. Elderly people are more harmed by bacterial infections due to their deficits in immunity. Because of the lack of new antibiotics in recent years, bacterial resistance has increasingly become a serious problem globally. In this study, an antibacterial compound predictor was constructed using the support vector machines and random forest methods and the data of the active and inactive antibacterial compounds from the ChEMBL database. The results showed that both models have excellent prediction performance (mean accuracy >0.9 and mean AUC >0.9 for the two models). We used the predictor to screen potential antibacterial compounds from FDA-approved drugs in the DrugBank database. The screening results showed that 1087 small-molecule drugs have potential antibacterial activity and 154 of them are FDA-approved antibacterial drugs, which accounts for 76.2% of the approved antibacterial drugs collected in this study. Through molecular fingerprint similarity analysis and common substructure analysis, we screened 8 predicted antibacterial small-molecule compounds with novel structures compared with known antibacterial drugs, and 5 of them are widely used in the treatment of various tumors. This study provides a new insight for predicting antibacterial compounds by using approved drugs, the predicted compounds might be used to treat bacterial infections and extend lifespan.

The genome of medicinal leech (Whitmania pigra) and comparative genomic study for exploration of bioactive ingredients.

BACKGROUND: Leeches are classic annelids that have a huge diversity and are closely related to people, especially medicinal leeches. Medicinal leeches have been widely utilized in medicine based on the pharmacological activities of their bioactive ingredients. Comparative genomic study of these leeches enables us to understand the difference among medicinal leeches and other leeches and facilitates the discovery of bioactive ingredients. RESULTS: In this study, we reported the genome of Whitmania pigra and compared it with Hirudo medicinalis and Helobdella robusta. The assembled genome size of W. pigra is 177 Mbp, close to the estimated genome size. Approximately about 23% of the genome was repetitive. A total of 26,743 protein-coding genes were subsequently predicted. W. pigra have 12346 (46%) and 10295 (38%) orthologous genes with H. medicinalis and H. robusta, respectively. About 20 and 24% genes in W. pigra showed syntenic arrangement with H. medicinalis and H. robusta, respectively, revealed by gene synteny analysis. Furthermore, W. pigra, H. medicinalis and H. robusta expanded different gene families enriched in different biological processes. By inspecting genome distribution and gene structure of hirudin, we identified a new hirudin gene g17108 (hirudin_2) with different cysteine patterns. Finally, we systematically explored and compared the active substances in the genomes of three leech species. The results showed that W. pigra and H. medicinalis exceed H. robusta in both kinds and gene number of active molecules. CONCLUSIONS: This study reported the genome of W. pigra and compared it with other two leeches, which provides an important genome resource and new insight into the exploration and development of bioactive molecules of medicinal leeches.

Ternary nickel-tungsten-copper alloy rivals platinum for catalyzing alkaline hydrogen oxidation.

Operating fuel cells in alkaline environments permits the use of platinum-group-metal-free (PGM-free) catalysts and inexpensive bipolar plates, leading to significant cost reduction. Of the PGM-free catalysts explored, however, only a few nickel-based materials are active for catalyzing the hydrogen oxidation reaction (HOR) in alkali; moreover, these catalysts deactivate rapidly at high anode potentials owing to nickel hydroxide formation. Here we describe that a nickel-tungsten-copper (Ni5.2WCu2.2) ternary alloy showing HOR activity rivals Pt/C benchmark in alkaline electrolyte. Importantly, we achieved a high anode potential up to 0.3 V versus reversible hydrogen electrode on this catalyst with good operational stability over 20 h. The catalyst also displays excellent CO-tolerant ability that Pt/C catalyst lacks. Experimental and theoretical studies uncover that nickel, tungsten, and copper play in synergy to create a favorable alloying surface for optimized hydrogen and hydroxyl bindings, as well as for the improved oxidation resistance, which result in the HOR enhancement.

Chimeric contribution of human extended pluripotent stem cells to monkey embryos ex vivo.

Interspecies chimera formation with human pluripotent stem cells (hPSCs) represents a necessary alternative to evaluate hPSC pluripotency in vivo and might constitute a promising strategy for various regenerative medicine applications, including the generation of organs and tissues for transplantation. Studies using mouse and pig embryos suggest that hPSCs do not robustly contribute to chimera formation in species evolutionarily distant to humans. We studied the chimeric competency of human extended pluripotent stem cells (hEPSCs) in cynomolgus monkey (Macaca fascicularis) embryos cultured ex vivo. We demonstrate that hEPSCs survived, proliferated, and generated several peri- and early post-implantation cell lineages inside monkey embryos. We also uncovered signaling events underlying interspecific crosstalk that may help shape the unique developmental trajectories of human and monkey cells within chimeric embryos. These results may help to better understand early human development and primate evolution and develop strategies to improve human chimerism in evolutionarily distant species.

Mass transfer process and separation mechanism of four 5'-ribonucleotides on a strong acid cation exchange resin.

5'-ribonucleotides including adenosine 5'-monophosphate (AMP), cytidine 5'-monophsphate (CMP), guanosine 5'-monophosphate (GMP) and uridine 5'-monophosphate (UMP) have been widely used in the food and pharmaceutical industries. This work focused on the assessment of mass transfer process and separation mechanism of four 5'-ribonucleotides and counter-ion Na+ on the strong cation exchange resin NH-1. The intraparticle diffusion was determined as the rate-limiting step for the mass transfer of AMP, CMP, GMP, and Na+ on the resin NH-1 through the Boyd model. Meanwhile, a homogeneous surface diffusion model (HSDM) combing ion exchange and physical adsorption was proposed and tested against adsorption kinetic data in the batch adsorption systems. The fixed-bed film-surface diffusion model based on the HSDM was then developed and successfully predicted the concentration profiles of 5'-ribonucleotides and the change of pH at the outlet of the fixed-bed in the dynamic adsorption and separation process. Finally, the separation mechanism of 5'-ribonucleotides was presented combining model prediction and experimental results. The separation of UMP, GMP and CMP were mainly based on their differences in isoelectric points, while that of AMP and CMP were lied with the discrepancy of their physical adsorption binding capacity with the resin NH-1.