One new triterpene glycoside from Cyclocarya paliurus.

One previously undescribed triterpene glycoside (1) and two known compounds were isolated from the leaves of Cyclocarya paliurus (2-3). Their structures were elucidated based on methods of spectroscopic analysis and NMR data comparison with those in the literature. Compound 1 showed a moderate inhibitory effect on melanogenesis with an IC50 value of 282.3 µM, with the positive drug arbutin showing an IC50 value of 168.5 µM.

Organocatalytic Atroposelective Construction of Pentatomic Heterobiaryl Diamines through Arylation of 5-Aminoisoxazoles with Azonaphthalenes.

An efficient catalytic asymmetric Michael-type reaction of azonaphthalenes with 5-aminoisoxazoles has been developed. The reaction was based on the utilization of a chiral phosphoric acid as the catalyst, delivering a large panel of axially chiral heterobiaryl diamines in generally good yields with excellent enantioselectivities. The gram-scale reaction and postmodification of the chiral product demonstrated their potentials in the synthesis of chiral catalysts and ligands. This approach not only provides a useful method for the construction of pentatomic heterobiaryl scaffolds but also offers new members to the axially chiral diamine family with promising applications in synthetic and medicinal chemistry.

Structuring Cu Membrane Electrode for Maximizing Ethylene Yield from CO2 Electroreduction.

Electrocatalytic ethylene (C2H4) evolution from CO2 reduction is an intriguing route to mitigate both the energy and environmental crises; however, to acquire industrially relevant high productivity and selectivity at low energy cost remains to be challenging. Membrane assembly electrode has shown great prospect and tailoring its architecture for maximizing C2H4 yield at minimum voltage with long-term stability becomes critical. Here a freestanding Cu membrane cathode is designed and constructed by electrochemically depositing mesoporous Cu film on Cu foam to simultaneously manage CO2, electron, water, and product transport, which shows an extraordinary C2H4 Faradaic efficiency of 85.6% with a full cell power conversion efficiency of 33% at a current density of 368 mA cm-2, heading the techno-economic viability for electrocatalytic C2H4 production.

Adverse childhood experiences affect the health of middle-aged and older people in China: The multiple mediating roles of sleep duration and life satisfaction.

Background: Although a significant amount of literature has examined the association between childhood adversity and adverse health outcomes, which may be affected by sleep duration and life satisfaction. However, this relationship has not been researched in the Chinese population. This study aimed to assess the association between childhood adversity and health outcomes, with sleep duration and life satisfaction as mediators. Methods: A total of 14,693 subjects aged 45 and over from the 2018 China Health and Retirement Longitudinal Study (CHARLS) were included. Taking childhood adversity as the independent variable, the health level of middle-aged and older individuals as the dependent variable, and sleep time and satisfaction as the mediating factors, Mplus 8.0 software was used to establish a structural equation model (SEM) to analyze the link between childhood adversity and health level and to explore the mediating effect of target mediators between childhood adversity and health level. Results: In this study, childhood adversity was positively associated with depression symptoms, activities of daily living (ADL), and the number of chronic diseases (r = 0.116, 0.026 and 0.050, respectively, P < 0.001). Associations between adverse childhood experiences (ACEs) and depressive symptoms, ADL, and number of chronic diseases were mediated by sleep duration and life satisfaction, respectively. Conclusion: Adversity experienced in childhood can affect the health status of middle-aged and older people. By ensuring adequate sleep and improving life satisfaction, health outcomes can be improved, and the negative effects of childhood adversity can be reduced.

Safety, pharmacokinetics, and pharmacodynamics of TG103, a novel long-acting GLP-1/Fc fusion protein after a single ascending dose in Chinese healthy subjects.

BACKGROUND AND OBJECTIVE: TG103 is a novel GLP-1/Fc fusion protein, developed for the treatment of type 2 diabetes and obesity. This trial was designed to assess the safety and tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) profiles after single ascending dose of TG103 in healthy Chinese subjects. METHOD: In this double-blind, randomized, placebo-controlled phase I study, Chinese healthy subjects were admitted consecutively to TG103 3 mg, 7.5 mg, 15 mg, and 22.5 mg group with 8 subjects per group and randomized in a 3:1 ratio to receive TG103 treatment or placebo. Following a single subcutaneous(s.c.) injections of TG103, safety and tolerability were evaluated and blood samples were collected for PK and PD analysis at the specified time-points. RESULT: Overall, 32 healthy subjects were enrolled and completed the study. During the study, a total of 84 adverse effects (AEs) were reported in 25 subjects, all were mild or moderate and resolved spontaneously without intervention. The most common treatment related AEs in TG103 group were decreased appetite (41.7%), nausea, flatulence, elevated urinary ß2-microglobulin, increased serum total bile acid (20.8% each), decreased high-density lipoprotein (16.7%), abdominal distension (12.5%). After a single s.c. administration of TG103 3-22.5 mg, the median Tmax was 36∼48 h, and mean t1/2 was about 147.16∼184.72 h. The mean Cmax for each group was 94.35±52.19, 337.67±56.71, 757.67±206.99, 1236.33±666.25 ng/mL, with AUC0-t of 14.93±7.67, 59.15±7.39, 91.79±20.41, 163.61±55.99 µg·h/mL, respectively. It showed a linear pharmacokinetic profile in the single dose of TG103 3 mg to 22.5 mg. Compared with placebo, fasting blood glucose decreased in all dose groups, most notably in the 15 mg group, which was consistent with the changes in blood glucose during OGTT, while 2-hour postprandial glucose decreased in all dose groups except 3 mg group. CONCLUSION: TG103 offers a potential option for hypoglycemic therapy with good tolerability and safety. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT03990090; registered 18 June 2019.

An optimal load indirect matching method without parameter identification and system efficiency optimization.

In some wireless charging applications where the coil spacing varies in real time, such as UAV, electric boat and tram, etc., the traditional direct impedance matching method is difficult to identify the mutual inductance timely and accurately, thus affecting the efficiency optimization effect of the system. In this paper, an indirect impedance matching method without parameter identification is proposed, this method is based on the characteristic that the optimal voltage gain of the resonator is only related to its inherent parameters, and impedance matching can be achieved by controlling the voltage gain in real time. To further improve the efficiency of the system, a single-sided detuning design method is used to achieve soft switching of the inverter. Based on the optimal voltage gain expression derived by using both the indirect impedance matching method and the single-sided detuning design method, a compound control strategy for a series-series-compensated topology with dual-side power control is proposed to improve efficiency and stabilize the output voltage. A hardware prototype is built and a peak DC-to-DC efficiency with the optimal output resistance RL at about 28.9 Ω is 91.58%. When the output resistance RL is 100 Ω, the efficiency improved by 7% after using the proposed strategy.

Room-Temperature Spin Transport in Metal Nanocluster-Based Spin Valves.

As a new type of inorganic-organic hybrid semiconductor, quantum-confined atomically precise metal nanoclusters (MNCs) have been widely applied in the fields of chemical sensing, optical imaging, biomedicine and catalysis. Herein, we successfully design and fabricate the first example of MNC-based spin valves (SVs) that exhibit remarkable magnetoresistance (MR) value up to 1.6 % even at room temperature (300 K). The concomitant photoresponse of MNC-based SVs unambiguously confirms that the spin-polarized electron transmission takes place across the MNC interlayer. Furthermore, the spin-dependent transport property of MNC-based SVs is largely varied by changing the atomic structure of MNCs. Both experimental proofs and quantum chemistry calculations reveal that the atomic structure-discriminative spin transport behavior is attributed to the distinct spin-orbit coupling (SOC) effect of MNCs.

Elevating Photooxidation of Methane to Formaldehyde via TiO2 Crystal Phase Engineering.

Photocatalytic conversion of methane to value-added products under mild conditions, which represents a long sought-after goal for industrial sustainable production, remains extremely challenging to afford high production and selectivity using cheap catalysts. Herein, we present the crystal phase engineering of commercially available anatase TiO2 via simple thermal annealing to optimize the structure-property correlation. A biphase catalyst with anatase (90%) and rutile (10%) TiO2 with the optimal phase interface concentration exhibits exceptional performance in the oxidation of methane to formaldehyde under the reaction conditions of water solvent, oxygen atmosphere, and full-spectrum light irradiation. An unprecedented production of 24.27 mmol gcat-1 with an excellent selectivity of 97.4% toward formaldehyde is acquired at room temperature after a 3 h reaction. Both experimental results and theoretical calculations disclose that the crystal phase engineering of TiO2 lengthens the lifetime of photogenerated carriers and favors the formation of intermediate methanol species, thus maximizing the efficiency and selectivity in the aerobic oxidation of methane to formaldehyde. More importantly, the feasibility of the scale-up production of formaldehyde is demonstrated by inventing a "pause-flow" reactor. This work opens the avenue toward industrial methane transformation in a sustainable and economical way.

Correction: Single atomic Fe-N4 active sites and neighboring graphitic nitrogen for efficient and stable electrochemical CO2 reduction.

Correction for 'Single atomic Fe-N4 active sites and neighboring graphitic nitrogen for efficient and stable electrochemical CO2 reduction' by Leta Takele Menisa et al., Nanoscale Horiz., 2022, https://doi.org/10.1039/D2NH00143H.

Single atomic Fe-N4 active sites and neighboring graphitic nitrogen for efficient and stable electrochemical CO2 reduction.

Single atomic Fe-Nx moieties have shown great performance in CO2-to-CO conversion. However, understanding the structural descriptors that determine the activity of Fe-Nx remains vague, and promising strategies to enhance their catalytic activity are still not clear. Herein, we used a high-temperature pyrolysis strategy and post-synthesis acid treatment for the direct growth of a single Fe-Nx site adjacent to graphitic nitrogen for the electrochemical CO2 reduction reaction. This strategy could significantly reduce the amount of pyridinic and pyrrolic N atoms, while graphitic N surrounding the Fe-Nx site predominantly increases. An experimental study combined with density functional theory revealed that the increase in the neighboring graphitic N decreases the number of electrons transferred between CO and the catalyst for FeN4-2N-3 and FeN4-4N-3, which results in the decrease of the adsorption strength of CO and the energy barrier for desorbing CO*. The as-synthesized Fe-Nx neighbored by graphitic nitrogen exhibited maximum faradaic efficiency of 91% at a lower overpotential of 390 mV. Due to the increase in the graphitic N, the catalysts perform efficiently for 35 h without any drop in current density.

Sodium Ions Affect Pyrraline Formation in the Maillard Reaction With Lys-Containing Dipeptides and Tripeptides.

Advanced glycation end products (AGEs) are potentially-hazardous chemical compounds, produced by the Maillard reaction between reducing sugars and Lysine side-chain amino groups in proteins. AGEs are strongly associated with diabetes, Alzheimer's disease and atherosclerosis. Pyrraline, a sugar derivative of Lysine, is a major AGE and an established marker for the presence of dietary AGEs. In this study, the effects of NaCl and different dipeptide and tripeptide structures were compared on the formation of pyrraline-containing peptides and the glucose derivative 3-deoxyglucosone in the presence of glucose and at different NaCl concentrations. The physicochemical properties (polarizability, dipole moment, molecular volume and dissociation constant) and the thermodynamic properties of the peptides were determined. The amount of the pyrraline decreased significantly in the following order of peptides (at the same concentrations): Lys-Phe > Lys-Ala > Lys-Gly; Lys-Gly-Phe > Lys-Gly-Ala > Lys-Gly-Gly. The highest levels of both pyrraline and 3-deoxyglucosone occurred at 0.2 mol/L Na+. Sodium ions appear to alter the intramolecular electron density and charge distribution of the peptides and facilitate the reaction by stabilizing some of the intermediates in the reaction sequence.

Applications of Nanomaterials in Asymmetric Photocatalysis: Recent Progress, Challenges, and Opportunities.

Asymmetric catalysis is one of the most attractive strategies to obtain important enantiomerically pure chemicals with high quality and production. In addition, thanks to the abundant and sustainable advantages of solar energy, photocatalysis possesses great potential in environmentally benign reactions. Undoubtedly, asymmetric photocatalysis meets the strict demand of modern chemistry: environmentally friendly and energy-sustainable alternatives. Compared with homogeneous asymmetric photocatalysis, heterogeneous catalysis has features of easy separation, recovery, and reuse merits, thus being cost- and time-effective. Herein, the state-of-the-art progress in asymmetric photocatalysis by heterogeneous nanomaterials is addressed. The discussion comprises two sections based on the type of nanomaterials: typical inorganic semiconductors like TiO2 and quantum dots and emerging porous materials including metal-organic frameworks, porous organic polymers, and organic cages. Finally, the challenges and future developments of heterogeneous asymmetric photocatalysis are proposed.

Insight into atomically dispersed porous M-N-C single-site catalysts for electrochemical CO2 reduction.

Transition metal single-site catalysts have unique activities for electrochemical CO2 reduction. However, the exact active center and reaction mechanism remain unclear due to a number of challenges in the controllable synthesis of single-atom catalysts (SACs) and defects in metal supports. Here we combine both experimental and theoretical calculations to systematically explore the mechanistic reaction path of selected transition metal single sites on nitrogen-doped porous carbon. Facile pyrolysis was employed to prepare a fullerene type carbon with 0.35 nm interlayer distances to support the family of M-N-C (M = Ni, Fe, Co and Cu). Experimentally, Ni and Fe outperform the other metals with high faradaic efficiency up to >97% and 86.8%, respectively. The theoretical calculations reveal that Ni-N-C exhibits optimum activity for CO2 reduction to CO at a higher overpotential because of the moderate *CO binding energy at the Ni site, which accommodates *COOH formation and *CO desorption. Furthermore, the strong binding energy of *CO on the Fe site enables the catalyst to reduce CO2 beyond CO. A remarkable current density of 17.6 mA cm-2 has been achieved with the Ni-N-C catalyst and a record of 5.74 s-1 TOF has been realized at -0.8 V vs. RHE for the Ni-N-C catalyst.

IL-33 deficiency protects mice from DSS-induced experimental colitis by suppressing ILC2 and Th17 cell responses.

BACKGROUND: Recently, IL-33-driven ILC2 response has been shown to participate in a variety of diseases. However, IL-33-driven ILC2 immunity has not been extensively characterized in the context of colitis yet. MATERIALS AND SUBJECTS: The RAG-2- and IL-33-deficient mice were used to investigate the role and underlying mechanisms of IL-33-driven ILC2 response in the DSS-induced experimental colitis. Body weight, length of colon, and histological analysis were monitored to evaluate the severity of colitis. Proportions of immune cells were examined by flow cytometry. Levels of cytokines were analyzed by ELISA and q-PCR. RESULTS: Administration of exogenous IL-33 aggravated the DSS-induced colitis, which revealed that IL-33 promoted the generation of ILC2 cells to mediate the inflammation of colon. Consistently, this effect was confirmed in RAG-2-deficient mice without T, B cells. Furthermore, IL-33-deficient mice were used to examine the role of endogenous IL-33 on the pathogenesis of DSS-induced colitis. Interestingly, lack of endogenous IL-33 protected the mice from the DSS-induced colitis. The protective effect is associated with impairments of development of ILC2 as well as Th17 cells. Analysis of their cytokine production profiles revealed that IL-33 deficiency resulted in the reduction of cytokines IL-6 and IL-1ß as well as IL-10. These results suggest that IL-33/ILC2 axis is a potential therapeutic target for human colitis. CONCLUSION: Our findings demonstrate that IL-33 deficiency protects mice from DSS-induced colitis. The protective effect is associated with impairments of ILC2 and Th17 cell development as well as reduction of inflammatory cytokines IL-6 and IL-1ß.

A reconstructed porous copper surface promotes selectivity and efficiency toward C2 products by electrocatalytic CO2 reduction.

Electrocatalytic synthesis of multicarbon (C2+) products from CO2 reduction suffers from poor selectivity and low energy efficiency. Herein, a facile oxidation-reduction cycling method is adopted to reconstruct the Cu electrode surface with the help of halide anions. The surface composed of entangled Cu nanowires with hierarchical pores is synthesized in the presence of I-, exhibiting a C2 faradaic efficiency (FE) of 80% at -1.09 V vs. RHE. A partial current density of 21 mA cm-2 is achieved with a C2 half-cell power conversion efficiency (PCE) of 39% on this electrode. Such high selective C2 production is found to mainly originate from CO intermediate enrichment inside hierarchical pores rather than the surface lattice effect of the Cu electrode.

Hydrolytic dehydrogenation of NH3BH3 catalyzed by ruthenium nanoparticles supported on magnesium-aluminum layered double-hydroxides.

Ammonia borane (AB, NH3BH3) with extremely high hydrogen content (19.6 wt%) is considered to be one of the most promising chemical hydrides for storing hydrogen. According to the starting materials of AB and H2O, a hydrogen capacity of 7.8 wt% is achieved for the AB hydrolytic dehydrogenation system with the presence of a highly efficient catalyst. In this work, ruthenium nanoparticles supported on magnesium-aluminum layered double hydroxides (Ru/MgAl-LDHs) were successfully synthesized via a simple method, i.e., chemical reduction. The effect of Mg/Al molar ratios in MgAl-LDHs on the catalytic performance for AB hydrolytic dehydrogenation was systematically investigated. Catalyzed by the as-synthesized Ru/Mg1Al1-LDHs catalyst, it took about 130 s at room temperature to complete the hydrolysis reaction of AB, which achieved a rate of hydrogen production of about 740 ml s-1 g-1. Furthermore, a relatively high activity (TOF = 137.1 molH2 molRu -1 min-1), low activation energy (E a = 30.8 kJ mol-1) and fairly good recyclability of the Ru/Mg1Al1-LDHs catalyst in ten cycles were achieved toward AB hydrolysis for hydrogen generation. More importantly, the mechanism of AB hydrolysis catalyzed by Ru/MgAl-LDHs was simulated via density functional theory. The facile preparation and high catalytic performance of Ru/MgAl-LDHs make it an efficient catalyst for hydrolytic dehydrogenation of AB.

Fast and Selective Semihydrogenation of Alkynes by Palladium Nanoparticles Sandwiched in Metal-Organic Frameworks.

The semihydrogenation of alkynes into alkenes rather than alkanes is of great importance in the chemical industry. Unfortunately, state-of-the-art heterogeneous catalysts hardly achieve high turnover frequencies (TOFs) simultaneously with almost full conversion, excellent selectivity, and good stability. Here, we used metal-organic frameworks (MOFs) containing Zr metal nodes ("UiO") with tunable wettability and electron-withdrawing ability as activity accelerators for the semihydrogenation of alkynes catalyzed by sandwiched palladium nanoparticles (Pd NPs). Impressively, the porous hydrophobic UiO support not only leads to an enrichment of phenylacetylene around the Pd NPs but also renders the Pd surfaces more electron-deficient, which leads to a remarkable catalysis performance, including an exceptionally high TOF of 13835 h-1 , 100 % phenylacetylene conversion 93.1 % selectivity towards styrene, and no activity decay after successive catalytic cycles. The strategy of using molecularly tailored supports is universal for boosting the selective semihydrogenation of various terminal and internal alkynes.

Zero-Dimensional-g-CNQD-Coordinated Two-Dimensional Porphyrin MOF Hybrids for Boosting Photocatalytic CO2 Reduction.

It is urgent yet challenging to develop photocatalysts for visible-light-driven CO2 reduction with high efficiency and selectivity. Here, we report a novel hybrid catalyst by coordinating zero-dimensional (0D) carbon nitride quantum dots (g-CNQDs) with two-dimensional (2D) ultrathin porphyrin MOF (PMOF). Different from previously reported hybrid catalysts combined through physical or electrostatic interactions, in our prepared g-CNQDs/PMOF hybrids, g-CNQDs are coordinated with Co active sites in PMOF, which significantly shortens the migrating pathway of both photogenerated charge carriers and gaseous substrates from g-CNQDs to Co active centers. The resulting efficient electron-hole pair separation and long-lived trapped electrons at Co centers not only boost the photocatalytic CO2 reduction activity but also improve its selectivity for the eight-electron reduced product CH4. To our knowledge, this is the first example of a hybrid catalyst combined through coordination interaction. Remarkably, the prepared hybrid catalyst exhibits a 2.34-fold enhancement in the CO generation rate (16.10 µmol g-1 h-1) and a 6.02-fold enhancement in the CH4 evolution rate (6.86 µmol g-1 h-1) compared to the bare PMOF.

Reordering d Orbital Energies of Single-Site Catalysts for CO2 Electroreduction.

The single-site catalyst (SSC) characteristic of atomically dispersed active centers will not only maximize the catalytic activity, but also provide a promising platform for establishing the structure-activity relationship. However, arbitrary arrangements of active sites in the existed SSCs make it difficult for mechanism understanding and performance optimization. Now, a well-defined ultrathin SSC is fabricated by assembly of metal-porphyrin molecules, which enables the precise identification of the active sites for d-orbital energy engineering. The activity of as-assembled products for electrocatalytic CO2 reduction is significantly promoted via lifting up the energy level of metal d z 2 orbitals, exhibiting a remarkable Faradaic efficiency of 96 % at the overpotential of 500 mV. Furthermore, a turnover frequency of 4.21 s-1 is achieved with negligible decay over 48 h.

Distinct Excitonic Circular Dichroism between Wurtzite and Zincblende CdSe Nanoplatelets.

Nanocrystals (NCs) with identical components and sizes but different crystal structures could not be distinguished by conventional absorption and emission spectra. Herein, we find that circular dichroism (CD) spectroscopy can easily distinguish the CdSe nanoplatelets (NPLs) with different crystal structures of wurtzite (WZ) and zincblende (ZB) with the help of chiral l- or d-cysteine ligands. In particular, the CD signs of the first excitonic transitions in WZ and ZB NPLs capped by the same chiral cysteine are opposite. Theoretic calculation supports the viewpoint of different crystal structures and surfaces arrangements between WZ and ZB NPLs contributing to this significant phenomenon. The CD peaks appearing at the first excitonic transition band of WZ or ZB CdSe NPLs are clearly assigned to the different transition polarizations along 4p( x,y,z),Se → 5sCd or 4p( x,y),Se → 5sCd. This work not only provides a deep insight into the origin of the optical activity inside chiral semiconductor nanomaterials but also proposes the design principle of chiral semiconductor nanocrystals with high optic activity.