Reversible Photochromic Phenomenon of Plasmonic Metal/Semiconductor Heterostructures via Photoinduced Electron Storage.

The transfer and migration process of the photogenerated charge carriers in plasmonic metal/semiconductor heterostructures not only affects their photocatalytic performance but also triggers some captivating phenomena. Here, a reversible photochromic behavior is observed on the Au/CdS heterostructures when they are investigated as photocatalysts for hydrogen production. The photochromism takes place upon excitation of the CdS component, in which the photogenerated holes are rapidly consumed by ethanol, while the electrons are transferred and stored on the Au cores, resulting in the blue shift of their localized surface plasmon resonance. The colloidal solution can restore its initial color after pumping with air, and the photochromic behavior can be cycled five times without obvious degradation. The finding represents great progress toward the photochromic mechanism of metal/semiconductor heterostructures and also reveals the importance of understanding the dynamic process of the photogenerated charge carriers in these heterostructures.

p-d Orbital Hybridization-Engineered PdSn Nanozymes for a Sensitive Immunoassay.

Nanozymes with peroxidase-like activity have been extensively studied for colorimetric biosensing. However, their catalytic activity and specificity still lag far behind those of natural enzymes, which significantly affects the accuracy and sensitivity of colorimetric biosensing. To address this issue, we design PdSn nanozymes with selectively enhanced peroxidase-like activity, which improves the sensitivity and accuracy of a colorimetric immunoassay. The peroxidase-like activity of PdSn nanozymes is significantly higher than that of Pd nanozymes. Theoretical calculations reveal that the p-d orbital hybridization of Pd and Sn not only results in an upward shift of the d-band center to enhance hydrogen peroxide (H2O2) adsorption but also regulates the O-O bonding strength of H2O2 to achieve selective H2O2 activation. Ultimately, the nanozyme-linked immunosorbent assay has been successfully developed to sensitively and accurately detect the prostate-specific antigen (PSA), achieving a low detection limit of 1.696 pg mL-1. This work demonstrates a promising approach for detecting PSA in a clinical diagnosis.

Catalase-like Fe Nanoparticles and Single Atoms Catalysts with Boosted Activity and Stability of Oxygen Reduction for Pesticide Detection.

Although oxygen reduction reaction (ORR) as an effective signal amplification strategy has been extensively investigated for the improvement of sensitivity of electrochemical sensors, their activity and stability are still a great challenge. Herein, single-atom Fe (FeSA) and Fe nanoparticles (FeNP) on nitrogen-doped carbon (FeSA/FeNP) catalysts demonstrate a highly active and stable ORR performance, thus achieving the sensitive and stable electrochemical sensing of organophosphorus pesticides (OPs). Experimental investigations indicate that FeNP in FeSA/FeNP can improve the ORR activity by adjusting the electronic structure of FeSA active sites. Besides, owing to the excellent catalase-like activity, FeSA/FeNP can rapidly consume in situ generated H2O2 in the ORR process and avoid the leakage of active sites, thereby improving the stability of ORR. Utilizing the excellent ORR performance of FeSA/FeNP, an electrochemical sensor for OPs is established based on the thiocholine-induced poison of the active sites, demonstrating satisfactory sensitivity and stability. This work provides new insight into the design of high performance ORR catalysts for sensitive and stable electrochemical sensing.

Biomimetic Electronic Communication of Iodine Doped Single-Atom Fe Site for Highly Active and Stable Dopamine Oxidation.

Rational design of highly active and stable catalysts for dopamine oxidation is still a great challenge. Herein, inspired by the catalytic pocket of natural enzymes, an iodine (I)-doped single Fe-site catalyst (I/FeSANC) is synthesized to mimic the catalytic center of heme enzymes in both geometrical and electronic structures, aiming to enhance dopamine (DA) oxidation. Experimental studies and theoretical calculations show that electronic communication between I and FeN5 effectively modulates the electronic structure of the active site, greatly optimizing the overlap of Fe 3d and O 2p orbitals, thereby enhancing OH adsorption. In addition, the electronic communication induced by iodine doping attenuates the attack of proton hydrogen on the active center, thereby enhancing the stability of I/FeSANC. This work provides new insights into the design of highly active and stable single-atom catalysts and enhances the understanding of catalytic mechanisms for DA oxidation at the atomic scale.

Thermal-to-Electrical Conversion Based on Salinity Gradient Driven by Evaporation.

Constructing concentration differences between anions and cations at the ends of an ionic conductor is an effective strategy in electricity generation for powering wearable devices. Temperature gradient or salinity gradient is the driving force behind such devices. But their corresponding power generation devices are greatly limited in actual application due to their complex structure and harsh application conditions. In this study, a novel ionic concentration gradient electric generator based on the evaporation difference of the electrolyte is proposed. The device can be constructed without the need for semipermeable membranes, and operation does not need to build a temperature difference. As a demonstration, a PVA-Na ionic hydrogel is prepared as an electrolyte for the device and achieved a thermovoltage of more than 200 mV and an energy density of 77.94 J m-2 at 323 K. Besides, the device exhibits the capability to sustain a continuous voltage output for a duration exceeding 1500 min, as well as enabling charging and discharging cycles for 100 iterations. For practical applications, a module comprising 16 sub-cells is constructed and successfully utilized to directly power a light-emitting diode. Wearable devices and their corresponding cell modules are also developed to recycle body heat.

Visible-Light-Driven Selective Hydrogenation of Nitrostyrene over Layered Ternary Sulfide Nanostructures.

Selective hydrogenation of nitrostyrenes is a great challenge due to the competitive activation of the nitro groups (─NO2 ) and carbon-carbon (C═C) double bonds. Photocatalysis has emerged as an alternative to thermocatalysis for the selective hydrogenation reaction, bypassing the precious metal costs and harsh conditions. Herein, two crystalline phases of layered ternary sulfide Cu2 WS4 , that is, body-centered tetragonal I-Cu2 WS4 nanosheets and primitive tetragonal P-Cu2 WS4 nanoflowers, are controlled synthesized by adjusting the capping agents. Remarkably, these nanostructures show visible-light-driven photocatalytic performance for selective hydrogenation of 3-nitrostyrene under mild conditions. In detail, the I-Cu2 WS4 nanosheets show excellent conversion of 3-nitrostyrene (99.9%) and high selectivity for 3-vinylaniline (98.7%) with the assistance of Na2 S as a hole scavenger. They also can achieve good hydrogenation selectivity to 3-ethylnitrobenzene (88.5%) with conversion as high as 96.3% by using N2 H4 as a proton source. Mechanism studies reveal that the photogenerated electrons and in situ generated protons from water participate in the former hydrogenation pathway, while the latter requires the photogenerated holes and in situ generated reactive oxygen species to activate the N2 H4 to form cis-N2 H2 for further reduction. The present work expands the rational synthesis of ternary sulfide nanostructures and their potential application for solar-energy-driven organic transformations.

A Robust n-n Heterojunction: CuN and BN Boosting for Ambient Electrocatalytic Nitrogen Reduction to Ammonia.

An n-n type heterojunction comprising with CuN and BN dual active sites is synthesized via in situ growth of a conductive metal-organic framework (MOF) [Cu3 (HITP)2 ] (HITP = 2,3,6,7,10,11-hexaiminotriphenylene) on hexagonal boron nitride (h-BN) nanosheets (hereafter denoted as Cu3 (HITP)2 @h-BN) for the electrocatalytic nitrogen reduction reaction (eNRR). The optimized Cu3 (HITP)2 @h-BN shows the outstanding eNRR performance with the NH3 production of 146.2 µg h-1 mgcat -1 and the Faraday efficiency of 42.5% due to high porosity, abundant oxygen vacancies, and CuN/BN dual active sites. The construction of the n-n heterojunction efficiently modulates the state density of active metal sites toward the Fermi level, facilitating the charge transfer at the interface between the catalyst and reactant intermediates. Additionally, the pathway of NH3 production catalyzed by the Cu3 (HITP)2 @h-BN heterojunction is illustrated by in situ FT-IR spectroscopy and density functional theory calculation. This work presents an alternative approach to design advanced electrocatalysts based on conductive MOFs.

Biomimetic Synthesis of an Antiviral Cinnamoylphloroglucinol Collection from Cleistocalyx operculatus: A Synthetic Strategy Based on Biogenetic Building Blocks.

A synthetic strategy based on biogenetic building blocks for the collective and divergent biomimetic synthesis of cleistoperlones A-F, a cinnamoylphloroglucinol collection discovered from Cleistocalyx operculatus, has been developed. These syntheses proceeded successfully in only six to seven steps starting from commercially available 1,3,5-benzenetriol and involving oxidative activation of stable biogenetic building blocks as a crucial step. Key features of the syntheses include a unique Michael addition/ketalization/1,6-addition/enol-keto tautomerism cascade reaction for the construction of the dihydropyrano[3,2-d]xanthene tetracyclic core of cleistoperlones A and B, and a rare inverse-electron-demand hetero-Diels-Alder cycloaddition for the establishment of benzopyran ring in cleistoperlones D-F. Moreover, cleistoperlone A exhibited significant antiviral activity against acyclovir-resistant strains of herpes simplex virus type 1 (HSV-1/Blue and HSV-1/153).

The transcription factor CCAAT/enhancer-binding protein ß in spinal microglia contributes to pre-operative stress-induced prolongation of postsurgical pain.

Prolongation of postsurgical pain caused by pre-operative stress is a clinically significant problem, although the mechanisms are not fully understood. Stress can promote the pro-inflammatory activation of microglia, and the transcription factor CCAAT/enhancer-binding protein (C/EBP) ß regulates pro-inflammatory gene expression in microglia. Therefore, we speculated that C/EBPß in spinal microglia may have critical roles in the development of chronic postsurgical pain. Accordingly, in this study, we used a single prolonged stress (SPS) procedure and plantar incisions to evaluate the roles of C/EBPß in postsurgical pain. Our experiments showed that SPS exposure prolonged mechanical allodynia, increased the expression of C/EBPß and pro-inflammatory cytokines, and potentiated the activation of spinal microglia. Subsequently, microinjection of C/EBPß siRNA attenuated the duration of SPS-prolonged postoperative mechanical allodynia and inhibited microglial activation in the spinal cord. Conversely, mimicking this increase in C/EBPß promoted microglial activation via pretreatment with a pre-injection of AAV5-C/EBPß, leading to prolongation of postsurgical pain. Overall, these results suggested that spinal microglia may play key roles in prolongation of postsurgical pain induced by pre-operative stress and that C/EBPß may be a potential target for disease treatment.

Discovery and Biomimetic Synthesis of a Polycyclic Polymethylated Phloroglucinol Collection from Rhodomyrtus tomentosa.

Inspired by a previously reported biomimetic synthesis study, four new naturally occurring phloroglucinol trimers 1-4 with unusual 6/5/5/6/6/6-fused hexacyclic ring systems, along with two known analogues (5 and 6) and two known biogenetically related dimers (10 and 11), were isolated from Rhodomyrtus tomentosa. Their structures and absolute configurations were unambiguously elucidated by spectroscopic analysis, X-ray diffraction, and electronic circular dichroism calculation. By mimicking two potentially alternative biosynthetic pathways, the first asymmetric syntheses of 1-4 and the racemic syntheses of 5 and 6 were achieved in only five to six steps without the need for protecting groups. Furthermore, phloroglucinol dimers 10 and 11 exhibited significant in vitro antiviral activity against the respiratory syncytial virus.

Activating transcription factor 4 aggravates angiotensin II-induced cell dysfunction in human vascular aortic smooth muscle cells via transcriptionally activating fibroblast growth factor 21.

Abdominal aortic aneurysm (AAA) is a life-threatening disorder worldwide. Fibroblast growth factor 21 (FGF21) was shown to display a high level in the plasma of patients with AAA; however, its detailed functions underlying AAA pathogenesis are unclear. An in vitro AAA model was established in human aortic vascular smooth muscle cells (HASMCs) by angiotensin II (Ang-II) stimulation. Cell counting kit-8, wound healing, and Transwell assays were utilized for measuring cell proliferation and migration. RT-qPCR was used for detecting mRNA expression of FGF21 and activating transcription factor 4 (ATF4). Western blotting was utilized for assessing protein levels of FGF21, ATF4, and markers for the contractile phenotype of HASMCs. ChIP and luciferase reporter assays were implemented for identifying the binding relation between AFT4 and FGF21 promoters. FGF21 and ATF4 were both upregulated in Ang-II-treated HASMCs. Knocking down FGF21 attenuated Ang-II-induced proliferation, migration, and phenotype switch of HASMCs. ATF4 activated FGF21 transcription by binding to its promoter. FGF21 overexpression reversed AFT4 silencing-mediated inhibition of cell proliferation, migration, and phenotype switch. ATF4 transcriptionally upregulates FGF21 to promote the proliferation, migration, and phenotype switch of Ang-II-treated HASMCs.

A home-based, post-discharge early intervention program promotes motor development and physical growth in the early preterm infants: a prospective, randomized controlled trial.

BACKGROUND: The implementation of early intervention (EI) in medical settings is time-consuming and resource-intensive, which limits its extensive use. In 2018, the Chinese Eugenics Association developed a home-based, post-discharge EI program. This study aims at evaluating the impact of this EI program on neurodevelopment and physical growth of early preterm infants. METHODS: This study was a prospective, partially blinded, randomized controlled trial (RCT), followed by an open phase. A total of 73 infants born at 28+ 0 ~ 31+ 6 weeks' gestation who were admitted to the Children's Hospital of Chongqing Medical University between December 1, 2019, and June 31, 2020, were enrolled. Another 33 infants were retrospectively recruited as the reference group. Thirty-seven infants randomized in the first early intervention, then standard care (EI-SC) group performed a 30-day EI during RCT period, while 36 infants allocated to SC-EI group were given EI in the following open phase. The test of infant motor performance (TIMP), development quotient (DQ), and anthropometric measures (length, weight, head circumference) were measured at the baseline (T0), termination of the RCT (T1), and termination of the open phase (T2). Repeated measures analysis was performed for comparison among groups. RESULTS: From T0 to T1, both groups had significant improvements in all outcome measures (all p < 0.001). A 30-day EI program was more effective in improving TIMP than standard care (from 53.12 ± 8.79 to 83.50 ± 11.85 in EI-SC group vs from 50.52 ± 8.64 to 75.97 ± 13.44 in SC-EI group, F = 4.232, p = 0.044). EI-SC group also had greater improvements in length, weight, and head circumference than SC-EI group (all p < 0.05). From T0 to T2, there was no significant difference regarding the improvements in all outcomes between the groups (all p > 0.05). At the endpoint of T2, the EI-SC and SC-EI group had similar TIMP and anthropometric measures, but much higher than the reference group (all p < 0.05). CONCLUSIONS: These findings demonstrated that a home-based, post-discharge EI program in this study was a practical approach to promote motor development and physical growth in early preterm infants. TRIAL REGISTRATION: CHICTR, CTR1900028330, registered December 19, 2019, https:// http://www.chictr.org.cn/showproj.aspx?proj=45706.

Effectiveness of photobiomodulation in the treatment of primary burning mouth syndrome-a systematic review and meta-analysis.

To evaluate the effectiveness of photobiomodulation (PBM) on primary burning mouth syndrome (pBMS). We searched Chinese and English studies published before February 10, 2020. The databases used include PubMed, EMBASE, the Cochrane Library, Web of Science, Wanfang Database, and China National Knowledge Infrastructure (CNKI). Randomized controlled clinical trials (RCTs) that used the PBM to treat pBMS and reported specific treatment outcomes were considered for inclusion. We eventually included 12 RCTs, and 574 samples were included in these studies. The primary outcomes investigated were pain reduction and life quality improvement. A meta-analysis performed on 9 groups in 5 trials showed that PBM was effective in reducing pain compared with placebo (MD - 1.86, 95% CI - 2.59 to - 1.13, Z = 4.99, P < 0.00001). Meta-analysis was also performed on 7 groups in 4 trials and showed that PBM was effective in improving life quality compared with placebo (MD - 3.43, 95% CI - 5.11 to - 1.75, Z = 4.00, P < 0.0001). Qualitative analysis of the included RCTs found that PBM might also play a role in the decrease of TNF-α and IL-6 in saliva. Three studies that compared PBM with medications were evaluated by descriptive analysis. None of the treatment-related adverse event was reported. Up to date, PBM appears to have an effect on pain reduction and life quality improvement in pBMS patients. However, more evidence is still required to warrant its efficacy and safety in treating pBMS.

Discovery of Neuritogenic Securinega Alkaloids from Flueggea suffruticosa by a Building Blocks-Based Molecular Network Strategy.

A combined strategy of building blocks recognition and molecular network construction, termed the building blocks-based molecular network (BBMN), was first presented to facilitate the efficient discovery of novel natural products. By mapping the BBMN of the total alkaloid fraction of Flueggea suffruticosa, three Securinega alkaloids (SEAs) with unusual chemical architectures, suffranidines A-C (1-3), were discovered and isolated. Compound 1 characterizes an unprecedented 8/5/6/5/6/6/6/6-fused octacyclic scaffold with a unique cage-shaped 3-azatricyclo[6.4.0.03,11 ]dodecane core. Compounds 2 and 3 are highly modified SEA dimers that incorporate additional C6 motifs. A hypothetical biosynthetic pathway for 1-3 was proposed. In addition, 1 significantly induced neuronal differentiation and neurite extension by upregulating eukaryotic elongation factor 2 (eEF2)-mediated protein synthesis.

Discovery and Biomimetic Synthesis of a Phloroglucinol-Terpene Adduct Collection from Baeckea frutescens and Its Biogenetic Origin Insight.

A phloroglucinol-terpene adduct (PTA) collection consisting of twenty-four molecules featuring three skeletons was discovered from Baeckea frutescens. Inspired by its biosynthetic hypothesis, we synthesized this PTA collection by reductive activation of stable phloroglucinol precursors into highly reactive ortho-quinone methide (o-QM) intermediates and subsequently Diels-Alder cycloaddition. We also demonstrated, for the first time, the generation process of the active o-QM by performing dynamic NMR and HPLC-MS monitoring experiments. Moreover, the PTA collection showed significant antifeedant effect toward the Plutella xylostella larvae.

ZLY032, the first-in-class dual FFA1/PPARδ agonist, improves glucolipid metabolism and alleviates hepatic fibrosis.

The free fatty acid receptor 1 (FFA1) and peroxisome proliferator-activated receptor δ (PPARδ) are considered as anti-diabetic targets based on their role in improving insulin secretion and resistance. Based on their synergetic mechanisms, we have previously identified the first-in-class dual FFA1/PPARδ agonist ZLY032. After long-term treatment, ZLY032 significantly improved glucolipid metabolism and alleviated fatty liver in ob/ob mice and methionine choline-deficient diet-fed db/db mice, mainly by regulating triglyceride metabolism, fatty acid ß-oxidation, lipid synthesis, inflammation, oxidative stress and mitochondrial function. Notably, ZLY032 exhibited greater advantages on lipid metabolism, insulin sensitivity and pancreatic ß-cell function than TAK-875, the most advanced candidate of FFA1 agonists. Moreover, ZLY032 prevented CCl4-induced liver fibrosis by reducing the expressions of genes involved in inflammation and fibrosis development. These results suggest that the dual FFA1/PPARδ agonists such as ZLY032 may be useful for the treatment of metabolic disorders.

A novel FFA1 agonist, CPU025, improves glucose-lipid metabolism and alleviates fatty liver in obese-diabetic (ob/ob) mice.

In the effort to identify anti-diabetic drug, we discovered a novel free fatty acid receptor 1 (FFA1) agonist CPU025, which is structurally different from previously reported FFA1 agonists. The present study revealed CPU025 is a potent FFA1 agonist (EC50 = 38.7 nM) with moderate agonistic activity on PPARδ (EC50 = 625.6 nM), and promotes insulin secretion at a glucose-dependent manner. Modeling study also illuminated CPU025 forms interaction with key residues closely related to the agonistic effects of FFA1 and PPARδ. Long-term treatment of CPU025 exerted better glycemic control and lipid profile than TAK-875, the most advanced FFA1 partial agonist in this field. Moreover, CPU025 improved ß-cell function and alleviated fatty liver in ob/ob mice. Further study suggested CPU025 could alleviate fatty liver through regulating the expression of genes involved in fatty acid ß-oxidation, lipoprotein lipolysis, lipid synthesis, oxidative stress and mitochondrial function. These results indicate that long-term treatment of CPU025 improves glucose and lipid metabolism, and may be useful for the treatment of diabetes mellitus and fatty liver.

Hepatic steatosis is associated with abnormal hepatic enzymes, visceral adiposity, altered myocardial glucose uptake measured by 18F-FDG PET/CT.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is a multisystem disease that affects the liver and a variety of extra-hepatic organ systems. This study aimed to investigate the relationship between hepatic steatosis and glucose metabolism in liver and extra-hepatic tissues and organs. METHODS: The whole body 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) images of 191 asymptomatic tumor screening patients were retrospectively analyzed. Patients with the ratio of spleen/liver CT densities > 1.1 were defined to have NAFLD, and their clinical symptoms, laboratory markers, FDG uptake in a variety of tissues and organs including heart, mediastinal blood pool, liver, spleen, pancreas, and skeletal muscle, as well as abdominal adipose tissue volumes including visceral adipose tissue (VAT) volume and subcutaneous adipose tissue (SAT) volume were compared with those of the non-NAFLD patients and used to analyze the independent correlation factors of NAFLD. RESULTS: Among the 191 patients, 33 (17.3%) were NAFLD, and 158 (82.7%) were non-NAFLD. There was no significant correlation between the mean standardized uptake value (SUVmean) and CT density of liver as well as the ratio of spleen/liver CT densities. Hepatic steatosis, but not FDG intake, was more significant in NAFLD patients with abnormal liver function than those with normal liver function. Compared with the non-NAFLD patients, NAFLD patients had significantly reduced myocardial glucose metabolism, but significantly increased mediastinal blood pool, spleen SUVmean and abdominal adipose tissue volumes (including VAT and SAT volumes) (P < 0.05). Multivariate regression analysis showed that elevated serum ALT, increased abdominal VAT volume, and decreased myocardial FDG uptake were independent correlation factors for NAFLD. Further studies showed that hepatic steatosis and myocardial FDG uptake were mildly linearly correlated (r = 0.366 with hepatic CT density and - 0.236 with the ratio of spleen/liver CT densities, P < 0.05). CONCLUSIONS: NAFLD is a systemic disease that can lead to the change of glucose metabolism in some extra-hepatic tissues and organs, especially the myocardium.

Unprecedented Quassinoids from Eurycoma longifolia: Biogenetic Evidence and Antifeedant Effects.

Six new quassinoids (1-6) were isolated from the roots of Eurycoma longifolia, and their structures with absolute configurations were determined unambiguously by spectroscopic analyses and single-crystal X-ray crystallographic experiments. Compounds 1 and 2 are the first members of a new class of quassinoids with an unusual C26 carbon skeleton. Compound 6 features a C20 cage-like scaffold with an unprecedented densely functionalized 2,5-dioxatricyclo[5.2.2.04,8]undecane core. The discovery of the two C26 quassinoids 1 and 2 has provided firm evidence for the better understanding the biogenetic process from C30 triterpenoid precursors to quassinoids. Compound 5 exhibited significant antifeedant activity on the diamondback moth (DBM) larvae and excellent systemic absorption and accumulated properties in Brassica chinensis.

Design, synthesis, and biological evaluation of novel dual PPARα/δ agonists for the treatment of T2DM.

Dual PPARα/δ agonists have been considered as potential therapeutics for the treatment of type 2 diabetes mellitus. After comprehensive structure-activity relationship study based on GFT505, a novel dual PPARα/δ agonist compound 6 was identified with highly activities on PPARα/δ and higher selectivity against PPARγ than that of GFT505. The modeling study revealed that compound 6 binds well to the binding pockets of PPARα and PPARδ, which formed multiple hydrogen bonds with key residues related to the activation of PPARα and PPARδ. Moreover, oral glucose tolerance test exhibited that compound 6 exerts dose-dependent anti-diabetic effects in ob/ob mice and reveals similar potency to that of GFT505, the most advanced candidate in this field. These findings suggested that compound 6 is a promising candidate for further researches, and the extended chemical space might help us to explore better PPARα/δ agonist.