Prussian-Blue-Analogue-Derived Ultrathin Co2P-Fe2P Nanosheets for Universal-pH Overall Water Splitting.

The great interest in large-scale electrochemical water splitting toward clean hydrogen has spurred large numbers of studies on developing cost-efficient and high-performance bifunctional electrocatalysts. Here, a Prussian-blue-analogue-derived method is proposed to prepare honeycomb-like ultrathin and heterogeneous Co2P-Fe2P nanosheets on nickel foam, showing low overpotentials of 0.080, 0.088, and 0.109 V for the hydrogen evolution reaction (HER) at 10 mA cm-2 as well as 0.290, 0.370, and 0.730 V for the oxygen evolution reaction (OER) at 50 mA cm-2 in alkaline, acidic, and neutral electrolytes, respectively. When directly applied for universal-pH water electrolysis, excellent performances are achieved especially at ultralow voltages of 1.45 V at 10 mA cm-2, 1.66 V at 100 mA cm-2, and 1.79 V at 500 mA cm-2 under alkaline conditions. In situ Raman spectroscopy measurements demonstrate that the excellent HER performance can be attributed to heterogeneous Co2P-Fe2P while the ultrahigh alkaline OER performance originates from reconstruction-induced oxyhydroxides.

Efficacy and safety comparison between axillary lymph node dissection with no axillary surgery in patients with sentinel node-positive breast cancer: a systematic review and meta-analysis.

BACKGROUND: This systematic review and meta-analysis aimed to study the evidence on the efficacy and safety of omitting axillary lymph node dissection (ALND) for patients with clinically node-negative but sentinel lymph node (SLN)-positive breast cancer using all the available evidence. METHODS: The Embase, Medline, and Cochrane Library databases were searched through February 25, 2023. Original trials that compared only the sentinel lymph node biopsy (SLNB) with ALND as the control group for patients with clinically node-negative but SLN-positive breast cancer were included. The primary outcomes were axillary recurrence rate, total recurrence rate, disease-free survival (DFS), and overall survival (OS). Meta-analyses were performed to compare the odds ratio (OR) in rates and the hazard ratios (HR) in time-to-event outcomes between both interventions. Based on different study designs, tools in the revised Cochrane risk of bias tool were used for randomized trials and the risk of bias in nonrandomized studies of interventions to assess the risk of bias for each included article. Funnel plots and Egger's test were used for the publication's bias assessment. RESULTS: In total, 30 reports from 26 studies were included in the systematic review (9 reports of RCTs, 21 reports of retrospective cohort studies). According to our analysis, omitting ALND in patients with clinically node-negative but SLN-positive breast cancer had a similar axillary recurrence rate (OR = 0.95, 95% confidence interval (CI): 0.76-1.20), DFS (HR = 1.02, 95% CI: 0.89-1.16), and OS (HR = 0.97, 95% CI: 0.92-1.03), but caused a significantly lower incidence of adverse events and benefited in locoregional recurrence rate (OR = 0.76, 95% CI: 0.59-0.97) compared with ALND. CONCLUSION: For patients with clinically node-negative but SLN-positive breast cancer (no matter the number of the positive SLN), this review showed that SLNB alone had a similar axillary recurrence rate, DFS, and OS, but caused a significantly lower incidence of adverse events and showed a benefit for the locoregional recurrence compared with ALND. An OS benefit was found in the Macro subset that used SLNB alone versus complete ALND. Therefore, omitting ALND is feasible in this setting. TRIAL REGISTRATION: CRD 42023397963.

Fads2b Plays a Dominant Role in ∆6/∆5 Desaturation Activities Compared with Fads2a in Common Carp (Cyprinus carpio).

Highly unsaturated fatty acids (HUFAs) are essential for mammalian health, development and growth. However, most mammals, including humans, are incapable of synthesizing n-6 and n-3 HUFAs. Fish can convert C18 unsaturated fatty acids into n-6 and n-3 HUFAs via fatty acid desaturase (Fads), in which Fads2 is a key enzyme in HUFA biosynthesis. The allo-tetraploid common carp theoretically encode two duplicated fads2 genes. The expression patterns and desaturase functions of these two homologous genes are still unknown. In this study, the full length of the fads2a and fads2b were identified in common carp (Cyprinus carpio). Expression analyses indicate that both genes were mainly expressed in the liver and the expression of fads2b is higher than fads2a at different developmental stages in carp embryos. Heterogenous expression and 3D docking analyses suggested that Fads2b demonstrated stronger ∆6 and ∆5 desaturase activities than Fads2a. The core promotor regions of fads2a and fads2b were characterized and found to have different potential transcriptional binding sites. These results revealed the same desaturase functions, but different activities of two homologues of fasd2 genes in common carp. The data showed that fads2b played a more important role in HUFA synthesis through both expression and functional analyses.

[Effect of total flavonoids of buckwheat flower and leaf on myocardial cell apoptosis and Wnt/ß-catenin/PPARγ pathway in arrhythmic rats].

This paper aimed to investigate the effect of total flavonoids of buckwheat flower and leaf on myocardial cell apoptosis and Wnt/ß-catenin/peroxisome proliferator-activated receptor γ(PPARγ) pathway in arrhythmic rats. SD rats were randomly divided into a control group, a model group, a low-dose(20 mg·kg~(-1)) group of total flavonoids of buckwheat flower and leaf, a medium-dose(40 mg·kg~(-1)) group of total flavonoids of buckwheat flower and leaf, a high-dose(80 mg·kg~(-1)) group of total flavonoids of buckwheat flower and leaf, a propranolol hydrochloride(2 mg·kg~(-1)) group, with 12 rats in each group. Except the control group, rats in other groups were prepared as models of arrhythmia by sublingual injection of 1 mL·kg~(-1) of 0.002% aconitine. After grouping and intervention with drugs, the arrhythmia, myocardial cells apoptosis, myocardial tissue glutathione peroxidase(GSH-Px), catalase(CAT), malondialdehyde(MDA), serum interleukin-6(IL-6), prostaglandin E2(PGE2) levels, myocardial tissue apoptosis, and Wnt/ß-catenin/PPARγ pathway-related protein expression of rats in each group were measured. As compared with the control group, the arrhythmia score, the number of ventricular premature beats, ventricular fibrillation duration, myocardial cell apoptosis rate, MDA levels in myocardial tissues, serum IL-6 and PGE2 levels, Bax in myocardial tissues, and Wnt1 and ß-catenin protein expression levels increased significantly in the model group, whereas the GSH-Px and CAT levels, and Bcl-2 and PPARγ protein expression levels in myocardial tissues reduced significantly. As compared with the model group, the arrhythmia score, the number of ventricular premature beats, ventricular fibrillation duration, myocardial cell apoptosis rate, MDA leve in myocardial tissues, serum IL-6 and PGE2 levels, Bax in myocardial tissues, and Wnt1 and ß-catenin protein expression levels reduced in the drug intervention groups, whereas the GSH-Px and CAT levels and Bcl-2 and PPARγ protein expression levels in myocardial tissues increased. The groups of total flavonoids of buckwheat flower and leaf were in a dose-dependent manner. There was no significant difference in the levels of each index in rats between the propranolol hydrochloride group and the high-dose group of total flavonoids of buckwheat flower and leaf. The total flavonoids of buckwheat flower and leaf inhibit the activation of Wnt/ß-catenin pathway, up-regulate the expression of PPARγ, reduce oxidative stress and inflammatory damage in myocardial tissues of arrhythmic rats, reduce myocardial cell apoptosis, and improve the symptoms of arrhythmia in rats.

Highly Dispersive Cerium Atoms on Carbon Nanowires as Oxygen Reduction Reaction Electrocatalysts for Zn-Air Batteries.

Highly efficient noble-metal-free electrocatalysts for oxygen reduction reaction (ORR) are essential to reduce the costs of fuel cells and metal-air batteries. Herein, a single-atom Ce-N-C catalyst, constructed of atomically dispersed Ce anchored on N-doped porous carbon nanowires, is proposed to boost the ORR. This catalyst has a high Ce content of 8.55 wt % and a high activity with ORR half-wave potentials of 0.88 V in alkaline media and 0.75 V in acidic electrolytes, which are comparable to widely studied Fe-N-C catalysts. A Zn-air battery based on this material shows excellent performance and durability. Density functional theory calculations reveal that atomically dispersed Ce with adsorbed hydroxyl species (OH) can significantly reduce the energy barrier of the rate-determining step resulting in an improved ORR activity.

Dominant Elongase Activity of Elovl5a but Higher Expression of Elovl5b in Common Carp (Cyprinus carpio).

Most diploid freshwater and marine fish encode one elovl5 elongase, having substrate specificity and activities towards C18, C20 and C22 polyunsaturated fatty acids (PUFAs). The allo-tetraploid common carp is hypothesized to encode two duplicated elovl5 genes. How these two elovl5 genes adapt to coordinate the PUFA biosynthesis through elongase function and expression divergence requires elucidation. In this study, we obtained the full-length cDNA sequences of two elovl5 genes in common carp, named as elovl5a and elovl5b. Functional characterization showed that both enzymes had elongase activity towards C18, C20 and C22 PUFAs. Especially, the activities of these two enzymes towards C22 PUFAs ranged from 3.87% to 8.24%, higher than those in most freshwater and marine fish. The Elovl5a had higher elongase activities than Elovl5b towards seven substrates. The spatial-temporal expression showed that both genes co-transcribed in all tissues and development stages. However, the expression levels of elovl5b were significantly higher than those of elovl5a in all examined conditions, suggesting that elovl5b would be the dominantly expressed gene. These two genes had different potential transcriptional binding sites. These results revealed the complicated roles of elovl5 on PUFA synthesis in common carp. The data also increased the knowledge of co-ordination between two homoeologs of the polyploid fish through function and expression divergence.

Single-Atomic Site Catalyst with Heme Enzymes-Like Active Sites for Electrochemical Sensing of Hydrogen Peroxide.

Heme enzymes, with the pentacoordinate heme iron active sites, possess high catalytic activity and selectivity in biosensing applications. However, they are still subject to limited catalytic stability in the complex environment and high cost for broad applications in electrochemical sensing. It is meaningful to develop a novel substitute that has a similar structure to some heme enzymes and mimics their enzyme activities. One emerging strategy is to design the Fe-N-C based single-atomic site catalysts (SASCs). The obtained atomically dispersed Fe-Nx active sites can mimic the active sites of heme enzymes effectively. In this work, a SASC (Fe-SASC/NW) is synthesized by doping single iron atoms in polypyrrole (PPy) derived carbon nanowire via a zinc-atom-assisted method. The proposed Fe-SASC/NW shows high heme enzyme-like catalytic performance for hydrogen peroxide (H2 O2 ) with a specific activity of 42.8 U mg-1 . An electrochemical sensor based on Fe-SASC/NW is developed for the detection of H2 O2 . This sensor exhibits a wide detection concentration range from 5.0 × 10-10 m to 0.5 m and an excellent limit of detection (LOD) of 46.35 × 10-9 m. Such excellent catalytic activity and electrochemical sensing sensitivity are attributed to the isolated Fe-Nx active sites and their structural similarity with natural metalloproteases.

An Ion-Imprinting Derived Strategy to Synthesize Single-Atom Iron Electrocatalysts for Oxygen Reduction.

Carbon-based single-atom catalysts (CSACs) have recently received extensive attention in catalysis research. However, the preparation process of CSACs involves a high-temperature treatment, during which metal atoms are mobile and aggregated into nanoparticles, detrimental to the catalytic performance. Herein, an ion-imprinting derived strategy is proposed to synthesize CSACs, in which isolated metal-nitrogen-carbon (Me-N4 -Cx ) moiety covalently binds oxygen atoms in Si-based molecular sieve frameworks. Such a feature makes Me-N4 -Cx moiety well protected/confined during the heat treatment, resulting in the final material enriched with single-atom metal active sites. As a proof of concept, a single-atom Fe-N-C catalyst is synthesized by using this ion-imprinting derived strategy. Experimental results and theoretical calculations demonstrate high concentration of single FeN4 active sites distributed in this catalyst, resulting in an outstanding oxygen reduction reaction (ORR) performance with a half-wave potential of 0.908 V in alkaline media.

Serum albumin guided plasmonic nanoassemblies with opposite chiralities.

Chiral assemblies by combining natural biomolecules with plasmonic nanostructures hold great promise for plasmonic enhanced sensing, imaging, and catalytic applications. Herein, we demonstrate that human serum albumin (HSA) and porcine serum albumin (PSA) can guide the chiral assembly of gold nanorods (GNRs) with left-handed chiroptical responses opposite to those by a series of other homologous animal serum albumins (SAs) due to the difference of their surface charge distributions. Under physiological pH conditions, the assembly of HSA or PSA with GNRs yielded left-handed twisted aggregates, while bovine serum albumin (BSA), sheep serum albumin, and equine serum albumin behaved on the contrary. The driving force for the chiral assembly is mainly attributed to electrostatic interaction. The opposite chiroptical signals acquired are correlated with the chiral surface charge distributions of the tertiary structures of SAs. Moreover, the chirality of the assembly induced by both HSA and BSA can be enhanced or reversed by adjusting the pH values. This work provides new insights into the modulation of protein-induced chiral assemblies and promotes their applications.

α-Selective C(sp3)-H Thio/Selenocyanation of Ketones with Elemental Chalcogen.

A facile method is disclosed for the synthesis of α-thio/selenocyanato ketones through regioselective C-H thio/selenocyanation of ketones. The advantages include the use of easily available starting materials, high efficiency, simple operation, and easy scale-up. Control experiments provide evidence that the reaction proceeded via a radical way, while kinetic isotope effect experiments reveal that the cleavage of the C-H bond serves as the rate-limiting step.

Single-Atom Nanozyme Based on Nanoengineered Fe-N-C Catalyst with Superior Peroxidase-Like Activity for Ultrasensitive Bioassays.

Single-atom catalysts are becoming a hot research topic owing to their unique characteristics of maximum specific activity and atomic utilization. Herein, a new single-atom nanozyme (SAN) based on single Fe atoms anchored on N-doped carbons supported on carbon nanotube (CNT/FeNC) is proposed. The CNT/FeNC with robust atomic Fe-Nx moieties is synthesised, showing superior peroxidase-like activity. Furthermore, the CNT/FeNC is used as the signal element in a series of paper-based bioassays for ultrasensitive detection of H2 O2 , glucose, and ascorbic acid. The SAN provides a new type of signal element for developing various biosensing techniques.

Heteroatom-Doped Carbon Nanotube and Graphene-Based Electrocatalysts for Oxygen Reduction Reaction.

Oxygen reduction reaction (ORR) is a key step that determines the performance of a variety of energy storage and conversion devices, such as fuel cells and metal-air batteries. Heteroatom-doped carbon nanotubes (CNTs) and graphenes have attracted increasing interest and hold great promise as efficient ORR catalysts to replace noble-metal-based catalysts, owing to their unique structure characteristics, excellent physicochemical properties, low cost, and rich resources. In this review, recent progress on the design, fabrication, and performance of heteroatom-doped CNT- and graphene-based catalysts is summarized, aiming to provide insights into the working mechanism of these heteroatom-doped nanocarbons in ORR. The advantages, challenges that remain, and possible solutions of these nanocarbon-based electrocatalysts are discussed. Finally, future developing trends of the CNT- and graphene-based ORR catalysts are proposed.

[Effect of Aralia echinocaulis containing serum on Wnt/ß-catenin signaling pathway of primary osteoblast].

This paper was aimed to investigate the effect of Aralia echinocaulis containing serum on expression of ß-catenin, Wnt-1, Frizzed-2, TCF and Axin in Wnt/ß-catenin signaling pathway of primary osteoblasts. SD healthy female rats (n=80) were used to make A. echinocaulis containing serum by gastric perfusion for seven days with distilled water, A. echinocaulis decoction high dosage, middle dosage, and low dosage. In vitro, primary osteoblasts were cultured and identified. The third generation primary osteoblasts were taken and cultured for 48 h, then cells were treated with the different drug serums for 10 days and calcified nodules were counted by alizarin red staining. The cells were collected after treatment for 48 h and the expression levels of ß-catenin, Wnt-1, Frizzled-2, TCF and Axin were detected by Real-time PCR and Western blot. The results suggested that the in vitro cells were primary osteoblasts; and after treatment, various doses groups could promote the mineralization ability of primary osteoblasts, up-regulate the mRNA and protein expression levels of ß-catenin, Wnt-1, Frizzled-2, and TCF, and down-regulate the mRNA and protein expression levels of Axin. These findings indicated that A. echinocaulis containing serum can enhance the differentiation and proliferation of osteoblasts by regulating the expression levels of ß-catenin, Wnt-1, Frizzled-2, TCF and Axin in Wnt/ß-catenin signaling pathway of primary osteoblasts.

Adequate nutrient intake mitigate the toxic effects of bromate on the rotifer Brachionus calyciflorus.

Bromate is receiving increased attention as a typical disinfection by-product in aquatic environments, but bromate toxicity tests on invertebrate such as Brachionus calyciflorus rotifer are inadequate. In the present study, the long-term toxicity tests on B. calyciflorus were performed during 21 days under the exposure of different bromate concentrations and two algal density conditions. Furthermore, we evaluated the feeding behaviors of the rotifers under the impact of bromate. The maximum population density of rotifers was significantly reduced at 100 and 200 mg/L bromate exposure at the two algal density conditions. However, we observed that the maximum population density and population growth rate of rotifers were higher at 3.0 × 106 cells/mL algal density than those at 1.0 × 106 cells/mL under the same conditions of bromate exposure. These results suggest that higher food density may have alleviated the negative effects of bromate on rotifers. Meanwhile, the ingestion rate at an algal density of 3.0 × 106 cells/mL was higher than that at 1.0 × 106 cells/mL. The present study provides a basic reference to comprehensively evaluate the toxic effects of bromate on aquatic organisms.

Multiscale nanoengineering fabrication of air electrode catalysts in rechargeable Zn-air batteries.

The development of cost-effective, high-activity and stable catalysts to accelerate the sluggish kinetics of cathodic oxygen reduction/evolution reactions (ORR/OER) plays a critical part in commercialization application of rechargeable Zn-air batteries (RZABs). Herein, a multiscale nanoengineering strategy is developed to simultaneously stabilize Co-doped Fe nanoparticles originated from metal-organic framework-derived approach and atomic Fe/Co sites derived from metal nanoparticle-atomized way on N-doped hierarchically tubular porous carbon substrate. Thereinto, metal nanoparticles and single atoms are respectively used to expedite the OER and ORR. Consequently, the final material is acted as an oxygen electrode catalyst, displaying 0.684 V of OER/ORR potential gap, 260 mW cm-2 of peak power density for liquid-state RZAB, 110 mW cm-2 of peak power density for solid-state RZAB, and 1000 charge-discharge cycles without decay, which confirms great potential for energy storage and conversion applications.

Effect of Phosphorus Modulation in Iron Single-Atom Catalysts for Peroxidase Mimicking.

Fe-N-C single-atom catalysts (SACs) exhibit excellent peroxidase (POD)-like catalytic activity, owing to their well-defined isolated iron active sites on the carbon substrate, which effectively mimic the structure of natural peroxidase's active center. To further meet the requirements of diverse biosensing applications, SAC POD-like activity still needs to be continuously enhanced. Herein, a phosphorus (P) heteroatom is introduced to boost the POD-like activity of Fe-N-C SACs. A 1D carbon nanowire (FeNCP/NW) catalyst with enriched Fe-N4 active sites is designed and synthesized, and P atoms are doped in the carbon matrix to affect the Fe center through long-range interaction. The experimental results show that the P-doping process can boost the POD-like activity more than the non-P-doped one, with excellent selectivity and stability. The mechanism analysis results show that the introduction of P into SAC can greatly enhance POD-like activity initially, but its effect becomes insignificant with increasing amount of P. As a proof of concept, FeNCP/NW is employed in an enzyme cascade platform for highly sensitive colorimetric detection of the neurotransmitter acetylcholine.

Universal Sublimation Strategy to Stabilize Single-Metal Sites on Flexible Single-Wall Carbon-Nanotube Films with Strain-Enhanced Activities for Zinc-Air Batteries and Water Splitting.

Single-metal-site catalysts have recently aroused extensive research in electrochemical energy fields such as zinc-air batteries and water splitting, but their preparation is still a huge challenge, especially in flexible catalyst films. Herein, we propose a sublimation strategy in which metal phthalocyanine molecules with defined isolated metal-N4 sites are gasified by sublimation and then deposited on flexible single-wall carbon nanotube (SWCNT) films by means of π-π coupling interactions. Specifically, iron phthalocyanine anchored on the SWCNT film prepared was directly used to boost the cathodic oxygen reduction reaction of the zinc-air battery, showing a high peak power density of 247 mW cm-2. Nickel phthalocyanine and cobalt phthalocyanine were, respectively, stabilized on SWCNT films as the anodic and cathodic electrocatalysts for water splitting, showing a low potential of 1.655 V at 10 mA cm-2. In situ Raman spectra and theoretical studies demonstrate that highly efficient activities originate from strain-induced metal phthalocyanine on SWCNTs. This work provides a universal preparation method for single-metal-site catalysts and innovative insights for electrocatalytic mechanisms.

Development of sandwich ELISA and lateral flow assay for the detection of Bungarus multicinctus venom.

Snakebite envenoming adversely affects human health and life worldwide. Presently, no suitable diagnostic tools for snakebite envenoming are available in China. Therefore, we sought to develop reliable diagnostic tests for snakebite management. We conducted affinity purification experiments to prepare species-specific antivenom antibody (SSAb). In brief, affinity chromatography with an antibody purification column (Protein A) was conducted to purify immunoglobulin G from Bungarus multicinctus (BM) venom hyperimmunized rabbit serum. The cross-reactive antibodies were removed from commercial BM antivenin by immune adsorption on the affinity chromatography columns of the other three venoms, Bungarus Fasciatus (FS), Naja atra (NA), and O. hannah (OH), generating SSAb. The results of western blot analysis and enzyme-linked immunosorbent assay (ELISA) showed the high specificity of the prepared SSAb. The obtained antibodies were then applied to ELISA and lateral flow assay (LFA) to detect BM venom. The resulting ELISA and LFA could specifically and rapidly detect BM venom in various samples with the limits of quantification as 0.1 and 1 ng/ml, respectively. This method could effectively detect snake venom in experimentally envenomed rats (simulating human envenomation), which could distinguish positive and negative samples within 10-15 min. This method also showed promise in serving as a highly useful tool for a rapid clinical distinguishing of BM bites and rational use of antivenom in emergency centers. The study also revealed cross-reactivity between BM and heterogenous venoms, suggesting that they shared common epitopes, which is of great significance for developing detection methods for venoms of the snakes belonging to the same family.

Effect of Several Naja atra Antivenom Injection Methods on the Rabbit Model of Naja naja atra Bite Poisoning.

Snakebite is a global public health concern, which often occurs in tropical and subtropical underdeveloped areas, but it is often neglected. In the southern China, Naja naja atra (Chinese cobra) is a common venomous snake that causes swelling and necrosis of local tissues, even amputation and death. Currently, the main therapy is the administration of Naja atra antivenom, which greatly reduces mortality. However, the antivenom is not particularly effective in the improvement of local tissue necrosis. Clinically, antivenom is mainly administered intravenously. We speculated that the method of injection influences the efficacy of antivenom. In this study, the rabbit model was used to explore the effects of different antivenom injection methods on systemic and local poisoning symptoms. If topical injection of antivenom contributes to ameliorate tissue necrosis, then we need to reconsider the use of Naja atra antivenom.