Unveiling the dance of evolution: Pla-mediated cleavage of Ymt modulates the virulence dynamics of Yersinia pestis.

Yersinia pestis has recently evolved into a highly lethal flea-borne pathogen through the pseudogenization of extensive genes and the acquisition of exogenous plasmids. Particularly noteworthy are the newly acquired pPCP1 and pMT1 plasmids, which encode the virulence determinants Pla and Yersinia murine toxin (Ymt), crucial for subcutaneous infection and survival within flea vector of Y. pestis, respectively. This study reveals that Pla can cleave Ymt at K299 both in vivo and in vitro. Y. pestis expressing YmtK299A displays enhanced in vitro biofilm formation and increased blood survival, indicating significant roles of Pla-mediated Ymt cleavage in these phenotypes. Intriguingly, although both the ancestral form of Pla and the prevalent Pla-I259T variant in modern Y. pestis strains are capable of cleaving Ymt at K299, the cleavage efficiency of Pla-I259T is only half that of the ancestral variant. In subcutaneous infection, mice infected with Δymt::ymt-K299A show significantly prolonged survival compared to those infected with Δymt::ymt. Similarly, infection with Δpla::pla-I259T also results in extended survival compared to Δpla::pla infection. These data demonstrate that the I259T substitution of Pla mitigates the enhanced virulence of Y. pestis in mice caused by Pla-mediated Ymt cleavage, thereby prolonging the survival period of infected animals and potentially conferring advantages on the transmission of Y. pestis to the next host. These findings deepen our understanding of the intricate interplay between two newly acquired plasmids and shed light on the positive selection of the Pla-I259T mutation, providing new insights into the virulence dynamics and transmission mechanisms of Y. pestis. IMPORTANCE: The emergence of Y. pestis as a highly lethal pathogen is driven by extensive gene pseudogenization and acquisition of exogenous plasmids pPCP1 and pMT1. However, the interplay between these two plasmids during evolution remains largely unexplored. Our study reveals intricate interactions between Ymt and Pla, two crucial virulence determinants encoded on these plasmids. Pla-mediated cleavage of Ymt significantly decreases Y. pestis survival in mouse blood and enhances its virulence in mice. The prevalent Pla-I259T variant in modern strains displays reduced Ymt cleavage, thereby extending the survival of infected animals and potentially increasing strain transmissibility. Our findings shed light on the nuanced evolution of Y. pestis, wherein reduced cleavage efficiency is a positive selection force, shaping the pathogen's natural trajectory.

Toxicity assessment of Cucurbita pepo cv Dayangua and its effects on gut microbiota in mice.

BACKGROUND: Cucurbita pepo cv Dayangua (CPD) is an edible plant with diverse pharmacological properties. The current research on CPD has primarily focused on initial investigations of its chemical composition and pharmacological effects, and no comprehensive toxicity assessment has been conducted to date. METHODS: In the present study, the toxicity of CPD was evaluated through both acute and sub-chronic oral toxicity tests in mice. 16S rDNA sequencing was used to analyze the composition of the gut microbiota of mice at different time points to observe the effect of CPD on these microbial communities. RESULTS: In the acute toxicity test, CPD exhibited low toxicity, with a median lethal dose (LD50) > 2000 mg/kg. The sub-chronic toxicity test indicated that CPD administration at doses of 200, 400, and 600 mg/kg did not cause mortality or significant organ damage in mice. Furthermore, analysis of the gut microbiota after gavage administration of CPD at 400 and 600 mg/kg revealed an improved abundance of some beneficial gut bacteria. CONCLUSIONS: In summary, no acute or sub-chronic toxic effects were observed in mice following the oral administration of CPD. CPD did not affect the structure and diversity of the gut microbiota and may contribute to an increase in the number of beneficial gut bacteria.

Superconductivity in Quasi-One-Dimensional Ferromagnet CrSbSe3 under High Pressure.

Nearly a decade has passed since the discovery of superconductivity in CrAs, but until now, the discovered structure types of chromium-based superconductors are still scanty. It is urgent to expand this family to decipher the interplay between magnetism and superconductivity penetratingly. Here, we report the observation of superconductivity in ferromagnet CrSbSe3 with a quasi-one-dimensional structure under high pressure. Under compression, CrSbSe3 undergoes an insulator-to-metal transition and sequential isostructural phase transitions accompanied by volume collapse. Superconductivity emerges at 32.8 GPa concomitant with metallization in CrSbSe3. A maximum superconducting transition temperature Tc of 7.7 K is achieved at 57.9 GPa benefiting from both the phonon softening and the enhanced p-d hybridization between Se and Cr in CrSbSe3. The discovery of superconductivity in CrSbSe3 expands the existing chromium-based superconductor family and sheds light on the search for concealed superconductivity in low-dimensional van der Waals materials.

Superconductivity in the High-Entropy Ceramics Ti0.2 Zr0.2 Nb0.2 Mo0.2 Ta0.2 Cx with Possible Nontrivial Band Topology.

Topological superconductors have drawn significant interest from the scientific community due to the accompanying Majorana fermions. Here, the discovery of electronic structure and superconductivity (SC) in high-entropy ceramics Ti0.2 Zr0.2 Nb0.2 Mo0.2 Ta0.2 Cx (x = 1 and 0.8) combined with experiments and first-principles calculations is reported. The Ti0.2 Zr0.2 Nb0.2 Mo0.2 Ta0.2 Cx high-entropy ceramics show bulk type-II SC with Tc ≈ 4.00 K (x = 1) and 2.65 K (x = 0.8), respectively. The specific heat jump (∆C/γTc ) is equal to 1.45 (x = 1) and 1.52 (x = 0.8), close to the expected value of 1.43 for the BCS superconductor in the weak coupling limit. The high-pressure resistance measurements show a robust SC against high physical pressure in Ti0.2 Zr0.2 Nb0.2 Mo0.2 Ta0.2 C, with a slight Tc variation of 0.3 K within 82.5 GPa. Furthermore, the first-principles calculations indicate that the Dirac-like point exists in the electronic band structures of Ti0.2 Zr0.2 Nb0.2 Mo0.2 Ta0.2 C, which is potentially a topological superconductor. The Dirac-like point is mainly contributed by the d orbitals of transition metals M and the p orbitals of C. The high-entropy ceramics provide an excellent platform for the fabrication of novel quantum devices, and the study may spark significant future physics investigations in this intriguing material.

Role of the Metal Precursor in Preparing Dual-Atom Catalysts for the Oxygen Reduction Reaction.

Dual-atom catalysts (DACs) have arisen as a novel type of heterogeneous catalyst that extends from single-atom catalysts (SACs) by incorporating two kinds of metals. These materials have demonstrated enhanced performance when compared to SACs. The choice of metal precursors plays an important role in the synthesis of DACs. Here, we choose Fe and Co as DAC models and study types, contents, molar ratios of two precursors, and oxygen reduction reaction (ORR) activity. The Fe,Co DACs were synthesized by an adsorption-annealing approach, using nitrogen-doped graphitic carbon (NC) as the support. As a result, the adsorption ability of metal precursors on the support determines the metal loadings in Fe and Co DACs, leading to differences in ORR performance. The Fe precursors win the adsorption competitions in most cases, resulting in a much higher loading than that of Co precursors. Importantly, it is difficult to increase the precursor content by simply increasing the initial amount. Choosing the right combination of metal precursors, such as ferrocene and cobalt chloride, can yield Fe,Co DACs with enhanced ORR performance..

Heck Migratory Insertion Catalyzed by a Single Pt Atom Site.

Single-atom catalysts (SACs) have generated excitement for their potential to downsize metal particles to the atomic limit with engineerable local environments and improved catalytic reactivities and selectivities. However, successes have been limited to small-molecule transformations with little progress toward targeting complex-building reactions, such as metal-catalyzed cross-coupling. Using a supercritical carbon-dioxide-assisted protocol, we report a heterogeneous single-atom Pt-catalyzed Heck reaction, which provides the first C-C bond-forming migratory insertion on SACs. Our quantum mechanical computations establish the reaction mechanism to involve a novel C-rich coordination site (i.e., PtC4) that demonstrates an unexpected base effect. Notably, the base was found to transiently modulate the coordination environment to allow migratory insertion into an M-C species, a process with a high steric impediment with no previous example on SACs. The studies showcase how SACs can introduce coordination structures that have remained underexplored in catalyst design. These findings offer immense potential for transferring the vast and highly versatile reaction manifold of migratory-insertion-based bond-forming protocols to heterogeneous SACs.

Characterization of the follicular fluid microbiota based on culturomics and sequencing analysis.

Introduction. The human oocyte microenvironment is follicular fluid, which is important for follicle growth, ovulation and maturation of the oocyte. The micro-organisms present in follicular fluid could be a predictor of in vitro fertilization outcomes.Hypothesis/Gap Statement. Women with follicular fluid colonized with micro-organisms can be asymptomatic, but the presence of some genera in the follicular fluid correlates with in vitro fertilization.Aim. To confirm the existence of micro-organisms in follicular fluid, and to profile the micro-organisms present in follicular fluid sampled from women undergoing in vitro fertilization with different outcomes.Methodology. Women undergoing in vitro fertilization (n=163) were divided into different subgroups according to their in vitro fertilization outcomes. Their follicular fluid samples were collected, and among them, 157 samples were analysed by 16S rDNA sequencing, and 19 samples were analysed using culturomics.Results. The culturomics results suggested that the 19 follicular fluid samples were not sterile. The isolation rates for Streptococcus, Finegoldia and Peptoniphilus were >50 % in the 19 samples. Linear discriminant analysis effect size analysis showed differential bacteria abundance according to the pregnancy rate, the rate of normal fertilization, the rate of high-quality embryos and the rate of available oocytes. The sequencing results showed that micro-organisms could be detected in all 157 samples. Pseudomonas, Lactobacillus, Comamonas, Streptococcus and Acinetobacter were detected in all of the samples, but with a wide range of relative abundance. Pseudomonas, Lactobacillus, Ralstonia and Vibrio constituted a notable fraction of the microbiota.Conclusions. Follicular fluid is not sterile. Micro-organisms in follicular fluid could be a predictor of in vitro fertilization outcomes.

Comparative Lysine Acetylome Analysis of Y. pestis YfiQ/CobB Mutants Reveals that Acetylation of SlyA Lys73 Significantly Promotes Biofilm Formation of Y. pestis.

Increasing evidence shows that protein lysine acetylation is involved in almost every aspect of cellular physiology in bacteria. Yersinia pestis is a flea-borne pathogen responsible for millions of human deaths in three global pandemics. However, the functional role of lysine acetylation in this pathogen remains unclear. Here, we found more acetylated proteins and a higher degree of acetylation in Y. pestis grown under mammalian host (Mh) conditions than under flea vector (Fv) conditions, suggesting that protein acetylation could significantly change during fleabite transmission. Comparative acetylome analysis of mutants of YfiQ and CobB, the major acetyltransferase and deacetylase of Y. pestis, respectively, identified 23 YfiQ-dependent and 315 CobB-dependent acetylated proteins. Further results demonstrated that acetylation of Lys73 of the SlyA protein, a MarR-family transcriptional regulator, inhibits its binding to the promoter of target genes, including hmsT that encodes diguanylate cyclase responsible for the synthesis of c-di-GMP, and significantly enhances biofilm formation of Y. pestis. Our study presents the first extensive acetylome data of Y. pestis and a critical resource for the functional study of lysine acetylation in this pathogen. IMPORTANCE Yersinia pestis is the etiological agent of plague, historically responsible for three global pandemics. The 2017 plague epidemic in Madagascar was a reminder that Y. pestis remains a real threat in many parts of the world. Plague is a zoonotic disease that primarily infects rodents via fleabite, and transmission of Y. pestis from infected fleas to mammals requires rapid adaptive responses to adverse host environments to establish infection. Our study provides the first global profiling of lysine acetylation derived from mass spectrometry analysis in Y. pestis. Our data set can serve as a critical resource for the functional study of lysine acetylation in Y. pestis and provides new molecular insight into the physiological role of lysine acetylation in proteins. More importantly, we found that acetylation of Lys73 of SlyA significantly promotes biofilm formation of Y. pestis, indicating that bacteria can use lysine acetylation to fine-tune the expression of genes to improve adaptation.

Twisted Diindeno-Fused Dibenzo[a,h]anthracene Derivatives and their Dianions.

We report a facile synthesis of diindeno-fused dibenzo[a,h]anthracene derivatives (DIDBA-2Cl, DIDBA-2Ph, and DIDBA-2H) with different degrees of non-planarity using three substituents (chloro, phenyl, and hydrogen) of various sizes. The planarization of their cores, as evidenced by the decreased end-to-end torsional angles, was confirmed by X-ray crystallography. Their enhanced energy gaps with twisting were investigated by a combination of spectroscopic and electrochemical methods with density functional theory, which showed a transition from singlet open-shell to closed-shell configuration. Moreover, their doubly reduced states, DIDBA-2Ph2- and DIDBA-2H2- , were achieved by chemical reduction. The structures of dianions were identified by X-ray crystallographic analysis, which elucidated that the electron charging further distorted the backbones. The electronic structure of the dianions was demonstrated by experimental and theoretical approaches, suggesting decreased energy gaps with larger non-planarity, different from the neutral species.

The breakdown of both strange metal and superconducting states at a pressure-induced quantum critical point in iron-pnictide superconductors.

Here we report the first observation of the concurrent breakdown of the strange metal (SM) normal state and superconductivity at a pressure-induced quantum critical point in Ca10(Pt4As8)((Fe0.97Pt0.03)2As2)5 superconductor. We find that, upon suppressing the superconducting state, the power exponent (α) changes from 1 to 2, and the slope of the temperature-linear resistivity per FeAs layer (A□) gradually diminishes. At a critical pressure, A□ and superconducting transition temperature (Tc) go to zero concurrently, where a quantum phase transition from a superconducting state with a SM normal state to a non-superconducting Fermi liquid state occurs. Scaling analysis reveals that the change of A□ with Tc obeys the relation of Tc ~ (A□)0.5, similar to what is seen in other chemically doped unconventional superconductors. These results suggest that there is a simple but powerful organizational principle of connecting the SM normal state with the high-Tc superconductivity.

Boosting Oxygen Electrocatalytic Activity of Fe-N-C Catalysts by Phosphorus Incorporation.

Nitrogen-doped graphitic carbon materials hosting single-atom iron (Fe-N-C) are major non-precious metal catalysts for the oxygen reduction reaction (ORR). The nitrogen-coordinated Fe sites are described as the first coordination sphere. As opposed to the good performance in ORR, that in the oxygen evolution reaction (OER) is extremely poor due to the sluggish O-O coupling process, thus hampering the practical applications of rechargeable zinc (Zn)-air batteries. Herein, we succeed in boosting the OER activity of Fe-N-C by additionally incorporating phosphorus atoms into the second coordination sphere, here denoted as P/Fe-N-C. The resulting material exhibits excellent OER activity in 0.1 M KOH with an overpotential as low as 304 mV at a current density of 10 mA cm-2. Even more importantly, they exhibit a remarkably small ORR/OER potential gap of 0.63 V. Theoretical calculations using first-principles density functional theory suggest that the phosphorus enhances the electrocatalytic activity by balancing the *OOH/*O adsorption at the FeN4 sites. When used as an air cathode in a rechargeable Zn-air battery, P/Fe-N-C delivers a charge-discharge performance with a high peak power density of 269 mW cm-2, highlighting its role as the state-of-the-art bifunctional oxygen electrocatalyst.

Subversion of GBP-mediated host defense by E3 ligases acquired during Yersinia pestis evolution.

Plague has caused three worldwide pandemics in history, including the Black Death in medieval ages. Yersinia pestis, the etiological agent of plague, has evolved a powerful arsenal to disrupt host immune defenses during evolution from enteropathogenic Y. pseudotuberculosis. Here, we find that two functionally redundant E3 ligase of Y. pestis, YspE1 and YspE2, can be delivered via type III secretion injectisome into host cytosol where they ubiquitinate multiple guanylate-binding proteins (GBPs) for proteasomal degradation. However, Y. pseudotuberculosis has no such capability due to lacking functional YspE1/2 homologs. YspE1/2-mediated GBP degradations significantly promote the survival of Y. pestis in macrophages and strongly inhibit inflammasome activation. By contrast, Gbpchr3-/-, chr5-/- macrophages exhibit much lowered inflammasome activation independent of YspE1/2, accompanied with an enhanced replication of Y. pestis. Accordingly, Gbpchr3-/-, chr5-/- mice are more susceptible to Y. pestis. We demonstrate that Y. pestis utilizes E3 ligases to subvert GBP-mediated host defense, which appears to be newly acquired by Y. pestis during evolution.

Yersinia pestis-Induced Mitophagy That Balances Mitochondrial Homeostasis and mROS-Mediated Bactericidal Activity.

Manipulating mitochondrial homeostasis is essential for host defense against infection and pathogen survival in cells. This study reports for the first time that Y. pestis infection caused mitochondria damage that subsequently leads to the activation of Pink1/Parkin-independent mitophagy in macrophage, and the effector YopH from the type III secretion system was required for these effects. The generation of mitochondrial reactive oxygen species (mROS) by damaged mitochondria enhances the antibacterial activity of macrophages against Y. pestis and promotes apoptosis of the infected cells. Therefore, Y. pestis-induced mitophagy was employed to eliminate dysfunctional mitochondria and relieve the mROS accumulation. This study reveals a novel role for YopH of Y. pestis in damaging host macrophage mitochondria during plague infection and underlines the vital role of mitophagy in maintaining mitochondrial homeostasis by clearing bacteria-damaged mitochondria. The results show that mitophagy or mitochondrial fission manipulation could be used as a new strategy to treat plague. IMPORTANCE Y. pestis, the pathogen of plague, also known as the "Black Death," has caused millions of deaths throughout history. This study reports that Y. pestis infection induces mitochondrial fragmentation and abnormal mROS accumulation, and releases mitochondrial contents into the cytoplasm in macrophages. mROS promotes the antibacterial activity of macrophages against Y. pestis and increases apoptosis of the infected cells. PINK-Parkin-independent mitophagy is activated to balance mitochondrial homeostasis and mROS-induced bactericidal activity in Y. pestis-infected macrophages. These findings deepen the understanding of Y. pestis pathogenesis on mitochondria damage to disturb the host cellular immune elimination. Manipulating mitophagic activity or mitochondrial fission may be a novel therapeutic approach to treat plague.

Sulfur doped FeNC catalysts derived from Dual-Ligand zeolitic imidazolate framework for the oxygen reduction reaction.

Iron-nitrogen-carbon (FeNC) catalysts derived from zeolitic-imidazolate frameworks (ZIFs) are worldwide accepted to be the most promising candidates for the oxygen reduction reaction (ORR), but the insufficient stability, the low FeNx exposure and poor density restrict their ORR activity. Here, we demonstrate a strategy to synthesize FeNx sites embedded in a micro/mesoporous N, S co-doped graphitic carbon (FeNC/MUS) by tuning the ligand linkers via the addition of 2-undecylimidazole as a co-ligand in ZIF precursors, and optimizing the electronic structure of Fe center by an in-situ addition of thiourea molecules as sulfur (S) source. 2-undecylimidazole offered an open porous structure to incorporate more FeNx, while the S-doping increased the density of FeNx. Besides, 2-undeclyimidazole cooperatively with S-doping caused favorable changes into the catalyst structure, particularly improved the exposure and density of FeNx sites and doubled the Brunauer-Emmetter-Teller surface area to 1132 m2 g-1 contrasted to the pristine FeNC/M (544 m2 g-1). FeNC/MUS displayed an accelerated ORR activity with a higher half-wave potential of 0.86 V (vs. reversible hydrogen electrode (RHE)) than that of Pt/C (0.84 V) in addition of a longer durability with a 11 % of activity decay after 30000 s in alkaline media. This work offers a new insight to design optimal ZIFs precursor and a facile electron withdrawing S-doping strategy for efficient electrocatalysis.

Facilitating the acidic oxygen reduction of Fe-N-C catalysts by fluorine-doping.

As the alternatives to expensive Pt-based materials for the oxygen reduction reaction (ORR), iron/nitrogen co-doped carbon catalysts (FeNC) with dense FeNx active sites are promising candidates to promote the commercialization of proton exchange membrane fuel cells. Herein, we report a synthetic approach using perfluorotetradecanoic acid (PFTA)-modified metal-organic frameworks as precursors for the synthesis of fluorine-doped FeNC (F-FeNC) with improved ORR performance. The utilization of PFTA surfactants causes profound changes of the catalyst structure including F-doping into graphitic carbon, increased micropore surface area and Brunauer-Emmett-Teller (BET) surface area (up to 1085 m2 g-1), as well as dense FeNx sites. The F-FeNC catalyst exhibits an improved ORR activity with a high E1/2 of 0.83 V (VS. RHE) compared to the pristine FeNC material (E1/2 = 0.80 V). A fast decay occurs in the first 10 000 potential cycles for the F-FeNC catalyst, but high durability is still maintained up to another 50 000 cycles. Density functional theory calculations reveal that the strongly withdrawing fluorine atoms doped on the graphitic carbon can optimize the electronic structure of the FeNx active center and decrease the adsorption energy of ORR intermediates.

Band Engineering and Morphology Control of Oxygen-Incorporated Graphitic Carbon Nitride Porous Nanosheets for Highly Efficient Photocatalytic Hydrogen Evolution.

Graphitic carbon nitride (g-C3N4)-based photocatalysts have shown great potential in the splitting of water. However, the intrinsic drawbacks of g-C3N4, such as low surface area, poor diffusion, and charge separation efficiency, remain as the bottleneck to achieve highly efficient hydrogen evolution. Here, a hollow oxygen-incorporated g-C3N4 nanosheet (OCN) with an improved surface area of 148.5 m2 g-1 is fabricated by the multiple thermal treatments under the N2/O2 atmosphere, wherein the C-O bonds are formed through two ways of physical adsorption and doping. The physical characterization and theoretical calculation indicate that the O-adsorption can promote the generation of defects, leading to the formation of hollow morphology, while the O-doping results in reduced band gap of g-C3N4. The optimized OCN shows an excellent photocatalytic hydrogen evolution activity of 3519.6 µmol g-1 h-1 for ~ 20 h, which is over four times higher than that of g-C3N4 (850.1 µmol g-1 h-1) and outperforms most of the reported g-C3N4 catalysts.

Efficacy and safety of electroacupuncture in treatment of cervical spondylosis: A protocol of randomized controlled trial.

BACKGROUND: Cervical Spondylotic radiculopathy (CSR) is the most common spinal degenerative disease. Its clinical manifestations are pain and numbness in the neck and arm and limitation of neck movement, which greatly affects the life and work of patients. Acupuncture and electroacupuncture are commonly used in China, the efficacy of acupuncture has been confirmed. Existing evidence shows that electroacupuncture seems to be better than acupuncture, but there is a lack of clinical research to directly compare the two. METHODS: This is a prospective randomized controlled trial to compare the efficacy of electroacupuncture and acupuncture in the treatment of CSR and to explore the safety and potential mechanism of electroacupuncture in the treatment of CSR. Approved by the Clinical Research Ethics Committee of our hospital, the patients are randomly divided into an experimental group (electroacupuncture group) or control group (acupuncture group). The patients are followed up for 30 days after 4 weeks of treatment. Observation indexes included VAS score, Neck Disability Index, Yasuhisa Tanaka 20 Score Scale, adverse reactions and so on. Finally, the data will be analyzed by SPSS 18.0 software. DISCUSSION: This study will directly compare the advantages and disadvantages of electroacupuncture and acupuncture in the treatment of CSR. The results of this study will help to guide patients with CSR to choose appropriate treatment. TRIAL REGISTRATION: OSF Registration number: DOI 10.17605/OSF.IO/9MKPN.

Efficacy and safety of Biqi capsule in the treatment of knee osteoarthritis: A protocol of a randomized controlled trial.

BACKGROUND: Knee osteoarthritis (KOA) is a chronic and degenerative bone and joint disease, with KOA, cartilage degeneration, destruction and subchondral bone remodeling as the main pathological features. Its clinical symptoms are knee pain, swelling, limited activity, and long course of disease can cause joint deformities. At present, the early treatment of Western medicine is mainly the use of nonsteroidal drugs for anti-inflammation and removing pain, but because the efficacy of these drugs is unstable, the disease is easy to repeat after treatment, and the clinical effect is not good. Although Biqi capsule has advantages in the treatment of KOA, there is a lack of standard clinical studies to verify it, so the purpose of this randomized controlled study is to evaluate the efficacy and safety of Biqi capsule in the treatment of KOA. METHODS: This is a prospective randomized controlled trial to study the efficacy and safety of Biqi capsule in the treatment of KOA. The patients were randomly divided into a treatment group and a control group according to 1:1. Among them, treatment group: Biqi capsule combined with diclofenac sodium sustained release tablets; Control group: Diclofenac sodium sustained-release tablets alone. Both groups were treated with standard treatment for 2 weeks and were followed up for 30 days to pay attention to the efficacy and safety indexes. Observation indicators included: the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Hospital for Special Surgery Knee Score (HSS), liver and kidney function, adverse reactions, and so on. SPSS 25.0 software is used for data analysis. DISCUSSION: This study will evaluate the efficacy and safety of Biqi capsule in the treatment of KOA, and the results of this experiment will provide a clinical basis for Biqi capsule in the treatment of KOA. TRIAL REGISTRATION: OSF Registration number: DOI 10.17605/OSF.IO/6HB9D.

Multilayer stabilization for fabricating high-loading single-atom catalysts.

Metal single-atom catalysts (M-SACs) have emerged as an attractive concept for promoting heterogeneous reactions, but the synthesis of high-loading M-SACs remains a challenge. Here, we report a multilayer stabilization strategy for constructing M-SACs in nitrogen-, sulfur- and fluorine-co-doped graphitized carbons (M = Fe, Co, Ru, Ir and Pt). Metal precursors are embedded into perfluorotetradecanoic acid multilayers and are further coated with polypyrrole prior to pyrolysis. Aggregation of the metals is thus efficiently inhibited to achieve M-SACs with a high metal loading (~16 wt%). Fe-SAC serves as an efficient oxygen reduction catalyst with half-wave potentials of 0.91 and 0.82 V (versus reversible hydrogen electrode) in alkaline and acid solutions, respectively. Moreover, as an air electrode in zinc-air batteries, Fe-SAC demonstrates a large peak power density of 247.7 mW cm-2 and superior long-term stability. Our versatile method paves an effective way to develop high-loading M-SACs for various applications.

A 3D nitrogen-doped graphene aerogel for enhanced visible-light photocatalytic pollutant degradation and hydrogen evolution.

Three-dimensional (3D) graphene-based aerogels have attracted widespread interest as promising photocatalysts for dye degradation and hydrogen production. Herein, we have developed a 3D nitrogen-doped graphene aerogel (3DNG) from graphitic carbon nitride combined with graphene oxide (GO). The nitrogen dopant in the 3D aerogel was achieved via a thermal treatment at 1000 °C, and the 3D aerogel catalyst could retain its 3D porous structure after the thermal treatment. The 3DNG was characterized via FTIR, Raman, TEM, UV-vis, XPS spectroscopies and BET analysis, and the results indicated that this 3DNG with a large surface area of 536 m2 g-1 and a band gap of 2.42 eV demonstrated a high adsorption capacity and enhanced methylene blue degradation and hydrogen production under visible light irradiation. Characterization also identified that the porous 3D structure with hydrogen bonding and π-π interactions and better charge transfer resulting from the nitrogen doping are the major reasons for the enhanced photocatalytic performance over this 3DNG catalyst.