Oxyanion Engineering on RuO2 for Efficient Proton Exchange Membrane Water Electrolysis.

In proton exchange membrane water electrolysis (PEMWE), the anode oxygen evolution reaction (OER) catalysts rely heavily on the expensive and scarce iridium-based materials. Ruthenium dioxide (RuO2) with lower price and higher OER activity, has been explored for the similar task, but has been restricted by the poor stability. Herein, we developed an anion modification strategy to improve the OER performance of RuO2 in acidic media. The designed multicomponent catalyst based on sulfate anchored on RuO2/MoO3 displays a low overpotential of 190 mV at 10 mA cm-2 and stably operates for 500 hours with a very low degradation rate of 20 µV h-1. When assembled in a PEMWE cell, this catalyst as an anode shows an excellent stability at 500 mA cm-2 for 150 h. Experimental and theoretical results revealed that MoO3 could stabilize sulfate anion on RuO2 surface to suppress its leaching during OER. Such MoO3-anchored sulfate not only reduces the formation energy of *OOH intermediate on RuO2, but also impedes both the surface Ru and lattice oxygen loss, thereby achieving the high OER activity and exceptional durability.

Intramolecular CH⋯π attraction mediated conformational polymorphism of constrained helical peptides.

In nature, biochemical processes depend on polymorphism, a phenomenon by which discrete biomolecules can adopt specific conformations based on their environment. However, it is often difficult to explore the generation mechanism and achieve polymorphic control in artificial supramolecular assembly systems. In this work, we propose a feasible thought for exploring the transformation mechanism of polymorphism in peptide assembly from the perspective of thermodynamic regulation, which enables polymorphic composition to be limited by switchable intramolecular CH⋯π attraction within a certain temperature range. Combined with the density functional theory calculations, we obtained thermodynamic theoretical data supporting the conformation transition and the underlying polymorphism formation principle. Afterward, we properly designed the peptide to alter the probability of CH⋯π attraction occurring. Then, we selectively obtained a homogeneous morphological form with corresponding molecular conformation, which further demonstrated the important role of molecular conformational manipulation in polymorphism selection. This unique template-based strategy developed in this study may provide scientists with an additional line of thought to guide assembly paths in other polymorphic systems.

Prognostic Impact of Neoadjuvant Chemotherapy in Localized or Locoregionally Advanced Gallbladder Cancer: A Population-Based and Propensity Score Matched SEER Analysis.

BACKGROUND: The effect of neoadjuvant chemotherapy (NACT) in gallbladder cancer (GBC) patients remains controversial. The aim of this study was to assess the impact of NACT on overall survival (OS) and cancer specific survival (CSS) in patients with localized or locoregionally advanced GBC, and to explore possible protective predictors for prognosis. METHODS: Data for patients with localized or locoregionally advanced GBC (i.e., categories cTx-cT4, cN0-2, and cM0) from 2004 to 2020 were collected from the Surveillance, Epidemiology, and End Results (SEER) database. Patients in the NACT and non-NACT groups were propensity score matched (PSM) 1:3, and the Kaplan-Meier method and log-rank test were performed to analyze the impact of NACT on OS and CSS. Univariable and multivariable Cox regression models were applied to identify the possible prognostic factors. Subgroup analysis was conducted to identify patients who would benefit from NACT. RESULTS: Of the 2676 cases included, 78 NACT and 234 non-NACT patients remained after PSM. In localized or locoregionally advanced GBC patients, the median OS of the NACT and non-NACT was 31 and 16 months (log-rank P < 0.01), and the median CSS of NACT and non-NACT was 32 and 17 months (log-rank P < 0.01), respectively. Longer median OS (31 vs 17 months, log-rank P < 0.01) and CSS (32 vs 20 months, log-rank P < 0.01) was associated with NACT compared with surgery alone. Multivariable Cox regression analysis showed that NACT, stage, and surgery type were prognostic factors for OS and CSS in GBC patients. Subgroup analysis revealed that the survival hazard ratios (HRs) of NACT vs non-NACT for localized or locoregionally advanced GBC patients were significant in most subgroups. CONCLUSIONS: NACT may provide therapeutic benefits for localized or locoregionally advanced GBC patients, especially for those with advanced stage, node-positive, poorly differentiated or undifferentiated disease. NACT combined with radical surgery was associated with a survival advantage. Therefore, NACT combined with surgery may provide a better treatment option for resectable GBC patients.

Efficient Synthesis of Cyanohydrin Esters: P(NMe2)3 Mediated Direct Deoxygenation of Acyl Cyanides with Carboxylic Acids.

An efficient synthesis of cyanohydrin esters via a P(NMe2)3 mediated direct deoxygenation process has been exploited, circumventing the release or transformation of the CN─ anion during the reaction. This approach possesses a broad scope and acts as a powerful supplement for the construction of diverse cyanohydrin esters. It offers advantages such as mild conditions, straightforward operations, and excellent scalability, affirming the feasibility and versatility of this approach and highlighting its potential in practical synthesis.

Clinical Guidelines on Compression Therapy in Venous Diseases.

BACKGROUND: In recent years, compression therapy has attracted gradually increasing clinical attention in lower extremity venous diseases. However, basic concepts and clear nomenclature, standard treatment methods, and consistent product standards for pressure equipment are lacking. Therefore, developing clinical guidelines for compression therapy is essential to improving the treatment of venous diseases. METHODS: Our panel generated strong (grade I), moderate (grade IIa and IIb), and weak (grade III) recommendations based on high-quality (class A), moderate-quality (class B), and low-quality (class C) evidence, using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach and the European Society of Cardiology (ESC) grading system. RESULTS: The panels made 30 recommendations from current evidence, focusing on 7 fields of lower extremity venous disease (venous thromboembolism, post-thrombotic syndrome (PTS), chronic venous insufficiency (CVI), varicose veins, hemangioma and vascular malformations, lymphedema, and venous ulcers) and 18 topics. CONCLUSIONS: Of the 30 recommendations made across the 18 topics, 7 were strong (grade I) and 17 were based on high-quality (class A) evidence, highlighting the need for further research of the use of compression therapy.

Phagocytic Plasma Cells in Teleost Fish Provide Insights into the Origin and Evolution of B Cells in Vertebrates.

Teleost IgM+ B cells can phagocytose, like mammalian B1 cells, and secrete Ag-specific IgM, like mammalian B2 cells. Therefore, teleost IgM+ B cells may have the functions of both mammalian B1 and B2 cells. To support this view, we initially found that grass carp (Ctenopharyngodon idella) IgM+ plasma cells (PCs) exhibit robust phagocytic ability, akin to IgM+ naive B cells. Subsequently, we sorted grass carp IgM+ PCs into two subpopulations: nonphagocytic (Pha-IgM+ PCs) and phagocytic IgM+ PCs (Pha+IgM+ PCs), both of which demonstrated the capacity to secrete natural IgM with LPS and peptidoglycan binding capacity. Remarkably, following immunization of grass carp with an Ag, we observed that both Pha-IgM+ PCs and Pha+IgM+ PCs could secrete Ag-specific IgM. Furthermore, in vitro concatenated phagocytosis experiments in which Pha-IgM+ PCs from an initial phagocytosis experiment were sorted and exposed again to beads confirmed that these cells also have phagocytic capabilities, thereby suggesting that all teleost IgM+ B cells have phagocytic potential. Additionally, we found that grass carp IgM+ PCs display classical phenotypic features of macrophages, providing support for the hypothesis that vertebrate B cells evolved from ancient phagocytes. These findings together reveal that teleost B cells are a primitive B cell type with functions reminiscent of both mammalian B1 and B2 cells, providing insights into the origin and evolution of B cells in vertebrates.

Recyclable Polythioesters and Poly(thioester-co-peptoid)s via Ring-Opening Cascade Polymerization of Amino Acid N-Carboxyanhydrides.

Polythioesters (PTEs) are emerging sustainable polymers for their degradability and recyclability. However, low polymerizability of monomers and extensive side reactions often hampered the polymerization process. Moreover, copolymers containing both thioester and other types of functional groups in the backbone are highly desirable but rarely accomplished owing to several synthetic challenges. Here, we report the ring-opening cascade polymerization (ROCAP) of N-(2-(acetylthio)ethyl)-glycine N-carboxyanhydrides (TE-NCA) to afford recyclable PTEs and unprecedented poly(thioester-co-peptoid)s (P(TE-co-PP)s) in a controlled manner. By developing appropriated carboxylic acid-tertiary amine dual catalysts, intramolecular S-to-N acyl shift is coupled into the ROCAP process of TE-NA to yield products with dispersity below 1.10, molecular weight (Mn) up to 84.5 kDa, and precisely controlled ratio of thioester to peptoids. Random copolymerization of sarcosine NCA (Sar-NCA) and TE-NCA gives thioester-embedded polysarcosine with facile backbone degradation while maintaining the water solubility. This work represents a paradigm shift for the ROP of NCAs, enriches the realm of cascade polymerizations, and provides a powerful synthetic approach to functional PTEs and P(TE-co-PP)s that are otherwise difficult or impossible to make.

Temporal variations and chemical characteristics of marine PM2.5 at Dongsha Islands, South China Sea: Three-year measurement.

The study of long-range transport effects on marine fine particles (PM2.5), particularly in remote sites such as the Dongsha Islands, is pivotal for advancing our understanding of air pollution dynamics on a regional scale and for formulating effective environmental policies. PM2.5 concentrations were examined over three consecutive years and grouped based on their transport routes. The backward trajectory simulation revealed that high PM2.5 concentrations were observed in the West Channel, originating from North and Central China, the Korean Peninsula, and the Japanese Islands, opposed to the East Channel. High PM2.5 concentrations, commonly observed in winter and spring, were mainly attributed to the Asian Northeastern Monsoons. Water-soluble inorganic ions constituted the major components, accounting for 37.8-48.7% of PM2.5, and followed by metal elements (15.5-20.0%), carbons (7.5-13.3%), levoglucosan (0.01-0.17%), and organic aerosols (0.2-2.2%). Secondary inorganic aerosols as the dominant source accounted for 8.3-24.7% of PM2.5, while sea salts were the secondary major contributor. High levoglucosan contribution (3.8-7.2%) in winter and spring was attributed to biomass burning, mainly from the Indochina Peninsula. Chemical mass balance receptor modeling resolved that major sources of PM2.5 were secondary sulfate, sea salts, fugitive dust, and industrial boilers. This study concluded that the long-range transport of PM2.5 gradually increased since fall, contributing 52.1-74.3%, highlighting its substantial impact on PM2.5 in all seasons except summer.

Novel STAT3 oligonucleotide compounds suppress tumor growth and overcome the acquired resistance to sorafenib in hepatocellular carcinoma.

Signal transducer and activator of transcription 3 (STAT3) plays an important role in the occurrence and progression of tumors, leading to resistance and poor prognosis. Activation of STAT3 signaling is frequently detected in hepatocellular carcinoma (HCC), but potent and less toxic STAT3 inhibitors have not been discovered. Here, based on antisense technology, we designed a series of stabilized modified antisense oligonucleotides targeting STAT3 mRNA (STAT3 ASOs). Treatment with STAT3 ASOs decreased the STAT3 mRNA and protein levels in HCC cells. STAT3 ASOs significantly inhibited the proliferation, survival, migration, and invasion of cancer cells by specifically perturbing STAT3 signaling. Treatment with STAT3 ASOs decreased the tumor burden in an HCC xenograft model. Moreover, aberrant STAT3 signaling activation is one of multiple signaling pathways involved in sorafenib resistance in HCC. STAT3 ASOs effectively sensitized resistant HCC cell lines to sorafenib in vitro and improved the inhibitory potency of sorafenib in a resistant HCC xenograft model. The developed STAT3 ASOs enrich the tools capable of targeting STAT3 and modulating STAT3 activity, serve as a promising strategy for treating HCC and other STAT3-addicted tumors, and alleviate the acquired resistance to sorafenib in HCC patients. A series of novel STAT3 antisense oligonucleotide were designed and showed potent anti-cancer efficacy in hepatocellular carcinoma in vitro and in vivo by targeting STAT3 signaling. Moreover, the selected STAT3 ASOs enhance sorafenib sensitivity in resistant cell model and xenograft model.

Risk assessment of imported malaria in China: a machine learning perspective.

BACKGROUND: Following China's official designation as malaria-free country by WHO, the imported malaria has emerged as a significant determinant impacting the malaria reestablishment within China. The objective of this study is to explore the application prospects of machine learning algorithms in imported malaria risk assessment of China. METHODS: The data of imported malaria cases in China from 2011 to 2019 was provided by China CDC; historical epidemic data of malaria endemic country was obtained from World Malaria Report, and the other data used in this study are open access data. All the data processing and model construction based on R, and map visualization used ArcGIS software. RESULTS: A total of 27,088 malaria cases imported into China from 85 countries between 2011 and 2019. After data preprocessing and classification, clean dataset has 765 rows (85 * 9) and 11 cols. Six machine learning models was constructed based on the training set, and Random Forest model demonstrated the best performance in model evaluation. According to RF, the highest feature importance were the number of malaria deaths and Indigenous malaria cases. The RF model demonstrated high accuracy in forecasting risk for the year 2019, achieving commendable accuracy rate of 95.3%. This result aligns well with the observed outcomes, indicating the model's reliability in predicting risk levels. CONCLUSIONS: Machine learning algorithms have reliable application prospects in risk assessment of imported malaria in China. This study provides a new methodological reference for the risk assessment and control strategies adjusting of imported malaria in China.

Precision Synthesis of Polysarcosine via Controlled Ring-Opening Polymerization of N-Carboxyanhydride: Fast Kinetics, Ultrahigh Molecular Weight, and Mechanistic Insights.

The rapid and controlled synthesis of high-molecular-weight (HMW) polysarcosine (pSar), a potential polyethylene glycol (PEG) alternative, via the ring-opening polymerization (ROP) of N-carboxyanhydride (NCA) is rare and challenging. Here, we report the well-controlled ROP of sarcosine NCA (Sar-NCA) that is catalyzed by various carboxylic acids, which accelerate the polymerization rate up to 50 times, and enables the robust synthesis of pSar with an unprecedented ultrahigh molecular weight (UHMW) up to 586 kDa (DP ∼ 8200) and exceptionally narrow dispersity (D̵) below 1.05. Mechanistic experiments and density functional theory calculations together elucidate the role of carboxylic acid as a bifunctional catalyst that significantly facilitates proton transfer processes and avoids charge separation and suggest the ring opening of NCA, rather than decarboxylation, as the rate-determining step. UHMW pSar demonstrates improved thermal and mechanical properties over the low-molecular-weight counterparts. This work provides a simple yet highly efficient approach to UHMW pSar and generates a new fundamental understanding useful not only for the ROP of Sar-NCA but also for other NCAs.

P(NMe2)3-Mediated Regioselective N-Alkylation of 2-Pyridones via Direct Deoxygenation of α-Keto Esters.

A practical and regioselective direct N-alkylation of 2-pyridones is enabled by use of α-keto esters in the P(NMe2)3-mediated deoxygenation process. The reaction proceeds under mild conditions to produce N-alkylated 2-pyridones with high selectivity and generality, and the protocol is shown to be applicable for the scale-up synthesis, which makes it promising for practical applications.

Emerging Xene-Based Single-Atom Catalysts: Theory, Synthesis, and Catalytic Applications.

In recent years, the emergence of novel 2D monoelemental materials (Xenes), e.g., graphdiyne, borophene, phosphorene, antimonene, bismuthene, and stanene, has exhibited unprecedented potentials for their versatile applications as well as addressing new discoveries in fundamental science. Owing to their unique physicochemical, optical, and electronic properties, emerging Xenes have been regarded as promising candidates in the community of single-atom catalysts (SACs) as single-atom active sites or support matrixes for significant improvement in intrinsic activity and selectivity. In order to comprehensively understand the relationships between the structure and property of Xene-based SACs, this review represents a comprehensive summary from theoretical predictions to experimental investigations. Firstly, theoretical calculations regarding both the anchoring of Xene-based single-atom active sites on versatile support matrixes and doping/substituting heteroatoms at Xene-based support matrixes are briefly summarized. Secondly, controlled synthesis and precise characterization are presented for Xene-based SACs. Finally, current challenges and future opportunities for the development of Xene-based SACs are highlighted.

Base Metal-Controlled Chemodivergent Cyclization of Propargylamines for the Atom-Economic Synthesis of Nitrogen Heterocycles.

Herein, a base metal-enabled chemodivergent cyclization of propargylamines for the atom-economic construction of nitrogen heterocycles has been developed. Due to the different modes of activation of metal to propargylamine, copper-catalyzed 6-endo-dig cyclization generates functionalized 2-substitued quinoline-4-carboxylates, while iron-promoted cascade amino Claisen rearrangement, aromatization, and aza-Michael addition afford diverse 2-substituted indole-3-carboxylate derivatives. Excellent selectivity, broad functional group tolerance, mild conditions, and flexible late-stage functionalization illustrate the high efficiency and synthetic utility of this chemodivergent reaction.

Sequential In Situ-Formed Kukhtin-Ramirez Adduct and P(NMe2)3-Catalyzed O-Phosphination of α-Dicarbonyls with P(O)-H.

O-Phosphination of α-dicarbonyls via sequential in situ formation of a Kukhtin-Ramirez adduct and a P(NMe2)3-catalyzed process has been exploited for the synthesis of α-phosphoryloxy carbonyls. A range of P(O)-H derivatives, including diarylphosphine oxides, arylphosphinates, and phosphinates, are competent candidates to be introduced into the α-dicarbonyls in this transformation, and various α-phosphoryloxy carbonyls are obtained. This approach possesses advantages of mild conditions, simple operations, atom economy, high efficiency, and gram-scale synthesis, which make it promising in the synthesis toolbox.

Exploring a Linear Combination Feature for Predicting the Conductance of Parallel Molecular Circuits.

An accurate rule for predicting conductance is the cornerstone of developing molecular circuits and provides a promising solution for miniaturizing electric circuits. The successful prediction of series molecular circuits has proven the possibility of establishing a rule for molecular circuits under quantum mechanics. However, the quantitatively accurate prediction has not been validated by experiments for parallel molecular circuits. Here we used 1,3-dihydrobenzothiophene (DBT) to build the parallel molecular circuits. The theoretical simulation and single-molecule conductance measurements demonstrated that the conductance of the molecule containing one DBT is the unprecedented linear combination of the conductance of the two individual channels with respective contribution weights of 0.37 and 0.63. With these weights, the conductance of the molecule containing two DBTs is predicted as 1.81 nS, matching perfectly with the measured conductance (1.82 nS). This feature offers a potential rule for quantitatively predicting the conductance of parallel molecular circuits.

Construction of Reinforced Self-Cleaning and Efficient Photothermal PDMS@GDY@Cu Sponges toward Anticorrosion and Antibacterial Applications.

Copper (Cu)-based materials are widely used in many fields from industry to life, including marine, medical apparatus and instruments, and microelectronic devices owing to their superior thermal, electrical, and mechanical properties. However, the interaction of copper with aggressive and fouling liquids under normal circumstances easily brings about severe bacterial accumulation, resulting in undesirable functionality degeneration and bacterial infections. In this contribution, we reported a novel copper-based sponge, polydimethylsiloxane (PDMS)@graphdiyne (GDY)@Cu, constructed by in situ synthesis of GDY on a commercial Cu sponge, followed by the modification of PDMS. The as-fabricated PDMS@GDY@Cu sponge not only possesses excellent self-cleaning activity against the pollution of daily drinks and dirt due to an improved static contact angle (~136°), but also display a remarkably enhanced anticorrosion performance, attributed to intimate coverage of chemically stable GDY and PDMS on the Cu sponge. Based on high photothermal effect of GDY, the PDMS@GDY@Cu sponge also displays significantly improved antibacterial activities under irradiation. In addition, due to excellent chemical stability of PDMS and GDY, self-cleaning behavior and photothermal-assisted antibacterial performance are well maintained after long-term attack of bacteria. These results demonstrate that GDY-based functional coatings hold great promises in the protection of copper devices under harsh conditions.

Rh-Catalyzed [4 + 1] Reaction of Cyclopropyl-Capped Dienes (but not Common Dienes) and Carbon Monoxide: Reaction Development and Mechanistic Study.

Transition-metal-catalyzed [4 + 1] reaction of dienes and carbon monoxide (CO) is the most straightforward and easily envisioned cyclization for the synthesis of five-membered carbocycles, which are ubiquitously found in natural products and functional molecules. Unfortunately, no test of this reaction was reported, and consequently, chemists do not know whether such kind of reaction works or not. Herein, we report that the [4 + 1] reaction of common dienes and CO cannot work, at least under the catalysis of [Rh(cod)Cl]2. However, using cyclopropyl-capped dienes (also named allylidenecyclopropanes) as substrates, the corresponding [4 + 1] reaction with CO proceeds smoothly in the presence of [Rh(cod)Cl]2. This [4 + 1] reaction, with a broad scope, provides efficient access to five-membered carbocyclic compounds of spiro[2.4]hept-6-en-4-ones. The [4 + 1] cycloadducts can be further transformed into other molecules by using the unique chemistry of cyclopropyl groups present in these molecules. The mechanism of this [4 + 1] reaction has been investigated by quantum chemical calculations, uncovering that cyclopropyl-capped dienes are strained dienes and the oxidative cyclization step in the [4 + 1] catalytic cycle can release this (angular) strain both kinetically and thermodynamically. The strain release in this step then propagates to all followed CO coordination/CO insertion/reductive elimination steps in the [4 + 1] catalytic cycle, helping the realization of this cycloaddition reaction. In contrast, common dienes (including cyclobutyl-capped dienes) do not have such advantages and their [4 + 1] reaction suffers from energy penalty in all steps involved in the [4 + 1] catalytic cycle. The reactivity of ene-allenes for the [4 + 1] reaction with CO is also discussed.