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Electrochemically reducing CO2 to valuable fuels or feedstocks is recognized as a promising strategy to simultaneously tackle the crises of fossil fuel shortage and carbon emission. Sn-based catalysts have been widely studied for electrochemical CO2 reduction reaction (CO2 RR) to make formic acid/formate, which unfortunately still suffer from low activity, selectivity and stability. In this work, halogen (F, Cl, Br or I) was introduced into the Sn catalyst by a facile hydrolysis method. The presence of halogen was confirmed by a collection of ex situ and in situ characterizations, which rendered a more positive valence state of Sn in halogen-incorporated Sn catalyst as compared to unmodified Sn under cathodic potentials in CO2 RR and therefore tuned the adsorption strength of the key intermediate (*OCHO) toward formate formation. As a result, the halogen-incorporated Sn catalyst exhibited greatly enhanced catalytic performance in electrochemical CO2 RR to produce formate. Agency for Science, Technology and Research (A*STAR) Ministry of Education (MOE) This work was supported by the fund from NUS Green Energy Program (WBS:A-0005323-05-00), FRC MOE T1 (WBS:A-0009184-00-00), A*STAR LCERFI Project (Award ID: U2102d2011),Ministry of Education of Singapore (Tier 1: RG4/20, RG2/21 and Tier 2: MOET2EP10120-0002), Agency for Science, Technology and Research (AME IRG: A20E5c0080),the National Natural Science Foundation of China (Grant No. 22075195), and Photon Science Research Center for Carbon Dioxide.

Infectious microbes that spread easily in healthcare facilities remain as the severe threat for the public health, especially among immunocompromised populations. Given the intricate problem of dramatic increase in resistance to common biocides, the development of safe and efficient biocide formulated agents to alleviate drug resistance is highly demanding. In this study, Schiff-base ligands were successfully formed on natural biopolymer of epsilon-poly-L-lysine (e-PL) decorated aldehyde functionalized mesoporous silica SBA-15 (CHO-SBA-15) for the selective coordination of silver ions, which was affirmed by various physicochemical methods. Besides the identified broad-spectrum antibacterial activities, the as-prepared Schiff-base silver nanocomplex (CHO-SBA-15/e-PL/Ag, CLA-1) exhibited an improved inhibitory effect on infectious pathogen growth typified by Escherichia coli and Staphylococcus aureus in comparison with two control silver complexes without Schiff-base conjugates, SBA-15/e-PL/Ag and CHO-SBA-15/Ag, respectively. In addition, CLA-1 remarkably inhibited the growth of Mycobacterium tuberculosis due to the excellent antimicrobial activity of silver species. Significantly, CLA-1 kills Candida albicans cells, inhibits biofilm formation, and eliminates preformed biofilms, with no development of resistance during continuous serial passaging. The antifungal activity is connected to disruption of bacterial cell membranes and increased levels of intracellular reactive oxygen species. In mouse models of multidrug-resistant C. albicans infection, CLA-1 exhibited efficient in vivo fungicidal efficacy superior to two antifungal drugs, amphotericin B and fluconazole. Moreover, CLA-1 treatment induces negligible toxicity against normal tissues with safety. Therefore, this study reveals the pivotal role of the molecular design of Schiff-base silver nanocomplex formation on biopolymer surface-functionalized silica mesopores as a green and efficient nanoplatform to tackle infectious microbes.

The morbidity and mortality of colorectal cancer (CRC) ranks fourth worldwide, moreover, the tumor microenvironment (TME) of CRC is quite complex, and is one of the necessary factors affecting promotion of tumor metastasis. PTPN2 is a tumor suppressor which plays an important role in cancer-related downstream molecular pathway. FSP-1 is highly-expressed in multiple types of tumor tissues and is a biomarker of stromal fibroblasts. To examine the function of PTPN2 in the metastasis of CRC, the study evaluated the co-expression level of PTPN2 and FSP-1 in CRC tissues by double staining, and demonstrated the relationship with clinical information about each patient. The roles of PTPN2 and FSP-1 were detected in vitro by proliferation and transwell assay through knockdown of expression level of PTPN2. Lower PTPN2 with higher FSP-1 expression was correlated with poor survival outcomes in CRC. TAFs contribute to the migration function of PTPN2 in CRC in vitro through inducing changes in the level of TGF-β1. Western blot and qRT-PCR assays were used to detect the mechanism of PTPN2 regulation of migration with TAFs in the JAK/STAT signaling pathway, moreover, TAFs contributed the function of PTPN2 in colorectal carcinogenesis in vivo. In summary, the study shed light on the effect of TAFs contributes the function of PTPN2 in colorectal carcinogenesis through activating JAK/STAT signaling pathway. In addition, double-staining assay could give us a unique perspective from which to study TME in CRC.

Helicobacter pylori is a major global pathogen and has been implicated in gastritis, peptic ulcer, and gastric carcinoma. The efficacy of the extensive therapy of H. pylori infection with antibiotics is compromised by the development of drug resistance and toxicity toward human gut microbiota, which urgently demands novel and selective antibacterial strategies. The present study was mainly performed to assess the in vitro and in vivo effects of a natural herbal compound, dihydrotanshinone I (DHT), against standard and clinical H. pylori strains. DHT demonstrated effective antibacterial activity against H. pylori in vitro (MIC50/90, 0.25/0.5 μg/ml), with no development of resistance during continuous serial passaging. Time-kill curves showed strong time-dependent bactericidal activity for DHT. Also, DHT eliminated preformed biofilms and killed biofilm-encased H. pylori cells more efficiently than the conventional antibiotic metronidazole. In mouse models of multidrug-resistant H. pylori infection, dual therapy with DHT and omeprazole showed in vivo killing efficacy superior to that of the standard triple-therapy approach. Moreover, DHT treatment induces negligible toxicity against normal tissues and exhibits a relatively good safety index. These results suggest that DHT could be suitable for use as an anti-H. pylori agent in combination with a proton pump inhibitor to eradicate multidrug-resistant H. pylori.

Antibiotic resistance in Helicobacter pylori has been growing worldwide with current treatment regimens. Development of new compounds for treatment of H. pylori infections is urgently required to achieve a successful eradication therapy in the future. Armeniaspirols, a novel class of natural products isolated from Streptomyces armeniacus, have been previously identified as antibacterial agents against Gram-positive pathogens. In this study, we found that armeniaspirol A (ARM1) exhibited potent antibacterial activity against H. pylori, including multidrug-resistant strains, with MIC range values of 4-16 μg ml-1 . The underlying mechanism of action of ARM1 against H. pylori involved the disruption of bacterial cell membranes. Also, ARM1 inhibited biofilm formation, eliminated preformed biofilms and killed biofilm-encased H. pylori in a dose-dependent manner. In a mouse model of multidrug-resistant H. pylori infection, dual therapy with ARM1 and omeprazole showed efficient in vivo killing efficacy comparable to the standard triple therapy, and induced negligible toxicity against normal tissues. Moreover, at acidic pH 2.5, ARM1 exhibited a much more potent anti-H. pylori activity than metronidazole. Thus, these findings demonstrated that ARM1 is a novel potent anti-H. pylori agent, which can be developed as a promising drug lead for treatment of H. pylori infections.

Atomically dispersed single-atom catalysts are among the most attractive electrocatalysts for the CO2 reduction reaction (CRR). To elucidate the origin of the exceptional activity of atomically dispersed Fe-N-C catalyst in CRR, we have performed operando 57Fe Mössbauer spectroscopic studies on a model single-Fe-atom catalyst with a well-defined N coordination environment. Combining with operando X-ray absorption spectroscopy, the in situ-generated four pyrrolic nitrogen atom-coordinated low-spin Fe(I) (LS FeIN4) featuring monovalent iron is identified as the reactive center for the conversion of CO2 to CO. Furthermore, density functional theory calculations reveal that the optimal binding strength of CO2 to the LS FeIN4 site, with strong orbital interactions between the singly occupied dz2 orbital of the Fe(I) site and the singly occupied π∗ orbital of [COOH] fragment, is the key factor for the excellent CRR performance. Agency for Science, Technology and Research (A*STAR) Ministry of Education (MOE) This work was supported by the National Key Projects for Fundamental Research and Development of China (2016YFA0202804), the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB36030200), the National Natural Science Foundation of China (21925803, 22033005, and 22038002), the Ministry of Education of Singapore (AcRF Tier 1 RG4/20 and RG115/18 and AcRF Tier 2 T2EP10120-0009), and Agency for Science, Technol-ogy, and Research (A*Star AME IRG A20E5c0080). This work was partially sponsored by the Guangdong Provincial Key Laboratory of Catalysis (no. 2020B121201002).

Helicobacter pylori is a major global pathogen, and its infection represents a key factor in the etiology of various gastric diseases, including gastritis, peptic ulcers, and gastric carcinoma. The efficacy of current standard treatment for H. pylori infection including two broad-spectrum antibiotics is compromised by toxicity toward the gut microbiota and the development of drug resistance, which will likely only be resolved through novel and selective antibacterial strategies. Here, we synthesized a small molecule, zinc linolenate (ZnLla), and investigated its therapeutic potential for the treatment of H. pylori infection. ZnLla showed effective antibacterial activity against standard strains and drug-resistant clinical isolates of H. pylori in vitro with no development of resistance during continuous serial passaging. The mechanisms of ZnLla action against H. pylori involved the disruption of bacterial cell membranes and generation of reactive oxygen species. In mouse models of multidrug-resistant H. pylori infection, ZnLla showed in vivo killing efficacy comparable and superior to the triple therapy approach when use as a monotherapy and a combined therapy with omeprazole, respectively. Moreover, ZnLla treatment induces negligible toxicity against normal tissues and causes minimal effects on both the diversity and composition of the murine gut microbiota. Thus, the high degree of selectivity of ZnLla for H. pylori provides an attractive candidate for novel targeted anti-H. pylori treatment.