Search

Owing to the Pt‐like electrocatalytic capability and moderate price, Ru‐based catalysts are considered as the Pt alternatives for electrochemical water splitting. However, they demonstrate limited catalytic performance under industrial‐level current densities. Herein, a novel electrocatalyst with an extremely low amount (0.85 wt.%) of Ru nanoclusters anchored on Cr‐doped Fe‐metal–organic frameworks (Ru@Cr─FeMOF) through a robust Cr─O─Ru bond is presented. The study unveils that such an architecture facilitates fast electron transfer and manipulates the highest occupied d orbital and d‐band centers of Ru sites, favoring both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) catalysis. The as‐prepared catalyst performs excellent reaction activity of 21 mV@10 mA cm−2 for HER and 230 mV@50 mA cm−2 for OER in alkaline solution, and realizes excellent water‐splitting performance at industrial‐level current densities (1.72 V@1000 mA cm−2), surpassing the state‐of‐the‐art literatures. [ABSTRACT FROM AUTHOR]

Design of non‐noble metal electrocatalysts with high catalytic activity and stability to replace commercial Pt/C is crucial in the commercialization development of Zn‐air batteries (ZABs). In this work, Co catalyst nanoparticles coupled with nitrogen‐doped hollow carbon nanoboxes were well designed through zeolite‐imidazole framework (ZIF‐67) carbonization. As a result, the 3D hollow nanoboxes reduced the charge transport resistance, and the Co nanoparticles loaded on nitrogen‐doped carbon supports exhibited excellent electrocatalytic performance for oxygen reduction reaction (ORR, E1/2=0.823 V vs. RHE), similar to that of commercial Pt/C. Moreover, the designed catalysts showed an excellent peak density of 142 mW cm−2 when applied on ZABs. This work provides a promising strategy for the rational design of non‐noble electrocatalysts with high performance for ZABs and fuel cells. [ABSTRACT FROM AUTHOR]

Calf thymus polypeptide (CTP), with a molecular mass of <10 kDa, is prepared from the thymus of less than 30-day-old newborn cattle. In the present study, the inhibitory function of CTP in colorectal cancer (CRC) was investigated in B6/JGpt- Apc em1Cin(MinC) /Gpt (Apc Min/+) mice. CTP hampered tumor development and enhanced the ratio of CD3e−NK1.1+ cells by 113.0% and CD3e+CD28+ cells by 84.7% in the peripheral blood of Apc Min/+ mice. CTP improved the richness, diversity, and evenness of the intestinal microbiota of Apc Min/+ mice, particularly by regulating the abundance of immune-related microorganisms. CTP effectively regulated the expression of immune-related cytokines, such as interleukin (IL)-2 (15.19% increment), IL-12 (17.47% increment), and transforming growth factor (TGF)-β (11.19% reduction). Additionally, it enhanced the levels of CD4 and CD8, as well as the ratio of helper T lymphocytes (Th)1/Th2 in the spleen and tumors of Apc Min/+ mice. In CTP-treated mice, reduced levels of programmed death-1 (PD-1), programmed cell death-ligand 1 (PD-L1), cytotoxic T lymphocyte-associated antigen 4 (CTLA4), activated nuclear factor of activated T cells 1 (NFAT1), and nuclear factor κB (NF-κB) p65 signaling were noted. Collectively, the anti-CRC effect of CTP is related to the modulation of intestinal microbiota-mediated immune function, which provides a reference for CTP as a therapeutic drug or a combination drug used in CRC treatment in a clinical setting. [ABSTRACT FROM AUTHOR]

We compared the physiological performance of two sub-strains of coccolithophore Gephyrocapsa oceanica NIES-1318, the originally well-calcified strain, and its low-calcified counterpart that significantly decreased the capacity to calcify under present (400 µatm, LC) and elevated pCO2 (1000 µatm, HC) conditions. There were no significant differences in the growth rates between the two sub-strains under LC condition. The growth rates of both sub-strains reduced under HC conditions and the decrease was significantly higher in the high-calcified cells than the low-calcified ones. The low-calcified cultures exhibited reduced production rates of particulate organic carbon (POC) and particulate organic nitrogen (PON), irrespective of CO2 conditions. The decrease in the PON production rates was considerably higher than that in the POC production rates. Compared with the high-calcified cells, a slight decrease was observed in cellular POC contents in the low-calcified cells, whereas cellular PON contents decreased more prominently. The POC/PON ratio showed no significant difference between the two pCO2 treatments in the high-calcified cultures, whereas elevated CO2 increased the rates in the low-calcified cells. We believe that the nitrogen acquisition by low-calcified cells was more susceptible to ocean acidification, probably due to a lack of stabilized microenvironment provided by coccoliths. Our results demonstrate that the calcification level can affect the biochemical responses of G. oceanica to ocean acidification, with likely consequences for marine biogeochemical cycling. [ABSTRACT FROM AUTHOR]

Acyclic ketone‐derived oxocarbenium ions are involved as intermediates in numerous reactions that provide valuable products, however, they have thus far eluded efforts aimed at asymmetric catalysis. We report that a readily accessible chiral carboxylic acid catalyst exerts control over asymmetric cyclizations of acyclic ketone‐derived trisubstituted oxocarbenium ions, thereby providing access to highly enantioenriched dihydropyran products containing a tetrasubstituted stereogenic center. The high acidity of the carboxylic acid catalyst, which exceeds that of the well‐known chiral phosphoric acid catalyst TRIP, is largely derived from stabilization of the carboxylate conjugate base through intramolecular anion‐binding to a thiourea site. [ABSTRACT FROM AUTHOR]

A three component reaction of aldehydes, cyclic secondary amines, and terminal alkynes is developed to prepare enantioenriched propargylamines. [ABSTRACT FROM AUTHOR]