电催化硝酸根还原合成氨:关于铁/铜基催化剂的研究展望

氨(NH_(3))是现代工业的重要化工原料之一,因其具有较高的能量密度、便于运输和储存的特点而被认为是一种非常有前景的储氢材料和可再生能源载体.电催化硝酸根还原(NO_(3)RR)是一种理想的绿色合成氨策略,同时可应用于废水中硝酸根(NO_(3)−)污染的去除.然而,NO_(3)RR涉及多个电子和质子转移过程,且存在析氢反应(HER)等竞争反应,导致NO_(3)RR的法拉第效率(FE)和选择性较低.近年来,精准构筑NO_(3)RR电催化剂,实现高效合成氨逐步成为电催化领域的研究热点.其中,铁/铜基催化剂因其优异的催化性能和经济可行性而备受关注.因此,对近年来具有代表性的铁/铜基催化剂的研究进展进行总结是非常必要的.本文首先简述了电化学NO_(3)RR合成氨可能发生的反应路径,主要围绕铁/铜基电催化剂在NO_(3)RR中可能涉及的反应历程和相应的中间体.在此基础上,针对不同的反应机理系统归纳了三种催化剂设计策略,包括单原子催化剂策略、双金属催化剂策略以及仿生催化剂策略等.随后,重点评析和讨论了原位实时表征技术,如原位电化学质谱、原位X射线吸收光谱和原位红外/拉曼等,在电催化NO_(3)RR合成氨研究领域中的代表性应用案例,并阐明了原位表征技术的发展和联用对于揭示NO_(3)RR本征活性位和动态机理的关键作用.最后,系统总结了当前NO_(3)RR所面临的核心挑战并对其未来的研究机遇和发展方向进行了展望,包括高效催化剂的关键描述符和设计策略,探究固-液界面的前沿原位表征技术开发,以及将NO_(3)RR与绿色反应(如二氧化碳转化和生物质转化等)高效耦联制备高值化学品.综上所述,尽管电催化NO_(3)RR合成氨目前仍面临诸多挑战,随着实验方案、科学理论和原位表征技术的不断发展,未来将会出现更多高效且稳定的NO_(3)RR催化剂.本文旨在为高效电催化剂的理性开发,深入理解其动态反应机理与催化剂构效关系提供参考.

Expert consensus on endodontic therapy for patients withsystemic conditions

The overall health condition of patients significantly affects the diagnosis, treatment, and prognosis of endodontic diseases. Asystemic consideration of the patient’s overall health along with oral conditions holds the utmost importance in determining thenecessity and feasibility of endodontic therapy, as well as selecting appropriate therapeutic approaches. This expert consensus is acollaborative effort by specialists from endodontics and clinical physicians across the nation based on the current clinical evidence,aiming to provide general guidance on clinical procedures, improve patient safety and enhance clinical outcomes of endodontictherapy in patients with compromised overall health.

The osteoclastic activity in apical distal region of molar mesial roots affects orthodontic tooth movement and root resorption in rats

The utilization of optimal orthodontic force is crucial to prevent undesirable side effects and ensure efficient tooth movement during orthodontic treatment.However,the sensitivity of existing detection techniques is not sufficient,and the criteria for evaluating optimal force have not been yet established.Here,by employing 3D finite element analysis methodology,we found that the apical distal region(A-D region)of mesial roots is particularly sensitive to orthodontic force in rats.Tartrate-resistant acidic phosphatase(TRAP)-positive osteoclasts began accumulating in the A-D region under the force of 40 grams(g),leading to alveolar bone resorption and tooth movement.When the force reached 80 g,TRAP-positive osteoclasts started appearing on the root surface in the A-D region.Additionally,micro-computed tomography revealed a significant root resorption at 80 g.Notably,the A-D region was identified as a major contributor to whole root resorption.It was determined that 40 g is the minimum effective force for tooth movement with minimal side effects according to the analysis of tooth movement,inclination,and hyalinization.These findings suggest that the A-D region with its changes on the root surface is an important consideration and sensitive indicator when evaluating orthodontic forces for a rat model.Collectively,our investigations into this region would aid in offering valuable implications for preventing and minimizing root resorption during patients’orthodontic treatment.

Role of iron-based catalysts in reducing NO_(x) emissions from coal combustion

Nitrogen oxide(NO_(x))pollutants emitted from coal combustion are attracting growing public concern.While the traditional technologies of reducing NO_(x) were mainly focused on terminal treatment,and the research on source treatment is limited.This paper proposes a new coal combustion strategy that significantly reduces NO_(x) emissions during coal combustion.This strategy has two important advantages in reducing NO_(x) emissions.First,by introducing iron-based catalyst at the source,which will catalyze the conversion of coke nitrogen to volatile nitrogen during the pyrolysis process,thereby greatly reducing the coke nitrogen content.The second is de-NO_(x) process by a redox reaction between NO_(x) and reducing agents(coke,HCN,NH_(3),etc.)that occurred during coke combustion.Compared to direct combustion of coal,coke prepared by adding iron-based catalyst has 46.1% reduction in NO_(x) emissions.To determine the effect of iron-based additives on de-NO_(x) performance,demineralized coal(de-coal)was prepared to eliminate the effect of iron-based minerals in coal ash.The effects of iron compounds,additive dosages,and combustion temperatures on de-NO_(x) efficiency are systematically studied.The results revealed that the NO_(x) emission of the coke generated by pyrolysis of de-coal loaded with 3%(mass)Fe_(2)O_(3) decreases to 27.3% at combustion temperature of 900℃.Two main reasons for lower NO_(x) emissions were deduced:(1)During the catalytic coal pyrolysis stage,the nitrogen content in the coke decreases with the release of volatile nitrogen.(2)Part of the NO_(x) emitted during the coke combustion was converted into N_(2) for the catalytic effect of the Fe-based catalysts.It is of great practical value and scientific significance to the comprehensive treatment and the clean utilization process of coal.

A Universal Real-Time Fluorescence qPCR Method for Identifying Epidemic Strains of African Swine Fever Virus

Objective Establishing a highly sensitive real-time fluorescence quantitative PCR (qPCR) method for universal testing of epidemic African swine fever virus (ASFV) strains. Methods The ASFV p72 gene was targeted to design primer probes covering 24 p72 genotypes. The optimal amount of dimethylsulphoxide (DMSO) for qPCR amplification was determined, Various sensitivity and limit of detection (LOD) tests were performed, and clinical samples from China and imported goods were tested. Results The optimal primer-probe combination could specifically detect ASFV, 1.5% DMSO was optimal for qPCR, and LOD reached 3.2 copies/μL with good reproducibility (n = 20, p = 0.369). The method was employed to test 142 clinically suspected samples, of which 30 pig blood and 37 pig tissue samples were ASFV-positive. Moreover, the positive testing rate for ASFV was higher than for the standard qPCR method recommended by the Office International Des Epizooties (OIE), and for the commercially available kit. Thus, our method is superior for testing weakly positive samples with low virus titre, and epidemic strains present in imported goods. Conclusion Our method could be employed for universal testing of epidemic ASFV strains worldwide, ensuring wider coverage of hosts and ASFV strains/endemic strains, reducing false negatives, and benefitting early diagnosis.

Porphyromonas gingivalis disrupts vascular endothelial homeostasis in a TLR-NF-κB axis dependent manner

Cardiovascular disease is still the leading cause of mortality worldwide.Vascular endothelial dysfunction is viewed as the initial step of most cardiovascular diseases.Many studies have indicated that periodontal pathogens,especially Porphyromonas gingivalis,are closely correlated with vascular endothelial homeostasis,but the function of P.gingivalis and the underlying mechanisms are still elusive.To illuminate the effects and elucidate the mechanisms of P.gingivalis on endothelial structural integrity,we developed P.gingivalis infection models in vivo and in vitro.Endothelial cell proliferation,differentiation and apoptosis were detected.Here,we showed that P.gingivalis can impair endothelial integrity by inhibiting cell proliferation and inducing endothelial mesenchymal transformation and apoptosis of endothelial cells,which reduce the cell levels and cause the endothelium to lose its ability to repair itself.A mechanistic analysis showed that TLR antagonist or NF-κB signalling inhibitor can largely rescue the damaged integrity of the endothelium caused by P.gingivalis,suggesting that TLR-NF-κB signalling plays a vital role in vascular endothelial homeostasis destroyed by P.gingivalis.These results suggest a potential intervention method for the prevention and treatment of cardiovascular disease.

Cancer incidence and mortality in Gansu province,2012

Objective： Population-based cancer registration data in 2012 from all available cancer registries in Gansu province were collected by the Central Cancer Registry of Gansu. The numbers of new cancer cases and cancer deaths in Gansu province with compiled cancer incidence and mortality rates were estimated. Methods： In 2015, data from 7 registries in Gansu province were qualified. The pooled data were stratified by area （urban/rural）, gender, age group （0, 1-4, 5-9, 10-14, ..., 85＋） and cancer type. New cancer cases and deaths were estimated using age-specific rates and corresponding population of Gansu province in 2012. The Chinese census data in 2000 and Segi＇s population were applied for age-standardized rates. All the rates were expressed per 100,000 person-years. Results： Qualified 7 cancer registries （3 urban and 4 rural registries） covered 2,956,560 populations of Gansu province in 2012. The percentage of cases morphologically verified （MV%） and death certificate-only cases （DCO%） were 72.41% and 1.65%, respectively, and the mortality to incidence rate ratio （M/I） was 0.63. It was estimated that there were 575,600 new cancer cases and 331,300 cancer deaths in Gansu province in 2012. The incidence rate was 223.29/100,000 （244.14/100,000 in males and 201.50/100,000 in females）, the age-standardized incidence rates by Chinese standard population （ASIRC） and by world standard population （ASIRVv＇） were 208.95/100,000 and 206.41/100,000 with the cumulative incidence rate （0-74 years old） of 22.49%. The crude incidence rate in urban areas was equal to that in rural areas. However, after adjusted by age, the cancer incidence rate in urban was the same as that of rural areas. The crude mortality in Gansu province was 128.54/100,000 （135.04/100,000 in males and 124.43/100,000 in females）, the age-standardized mortality rates by Chinese standard population （ASMRC） and by world standard population （ASMRW） were 109.54/100,000 and 108.44/100,000, respectively, and the cumulative mortality rate （0-74 years old） was 12.91%. The crude cancer mortality rate in urban areas was higher than that of rural areas. However, the age- standardized rate in urban areas was the same as that of rural areas. Cancers of stomach, liver, lung, esophagus, female breast, colorectum, cervix, brain, pancreas and ovary were the most common cancers, accounting for about 83.56% of all cancer new cases. Stomach cancer, liver cancer, lung cancer, esophageal cancer, female breast cancer, colorectal cancer, brain cancer, lymphoma, pancreatic cancer and cervix cancer were the leading causes of cancer death, accounting for about 85.58% of all cancer deaths. The burden between urban and rural, males and females was different. Conclusions： Registration data of Gansu province were qualified to provide basic information on population-based cancer incidence, mortality for cancer prevention and control. The digestive tract cancer burden in Gansu province, especially for males in rural areas, was higher. The incidence rate of female breast cancer was higher in urban areas. Targeted prevention, early detection and treatment programs should be carried out by health department to control the cancer burden.

Low intensity near-infrared light promotes bone regeneration via circadian clock protein cryptochrome 1

Bone regeneration remains a great clinical challenge. Low intensity near-infrared(NIR) light showed strong potential to promote tissue regeneration, offering a promising strategy for bone defect regeneration. However, the effect and underlying mechanism of NIR on bone regeneration remain unclear. We demonstrated that bone regeneration in the rat skull defect model was significantly accelerated with low-intensity NIR stimulation. In vitro studies showed that NIR stimulation could promote the osteoblast differentiation in bone mesenchymal stem cells(BMSCs) and MC3T3-E1 cells, which was associated with increased ubiquitination of the core circadian clock protein Cryptochrome 1(CRY1) in the nucleus. We found that the reduction of CRY1 induced by NIR light activated the bone morphogenetic protein(BMP) signaling pathways, promoting SMAD1/5/9 phosphorylation and increasing the expression levels of Runx2 and Osterix. NIR light treatment may act through sodium voltage-gated channel Scn4a, which may be a potential responder of NIR light to accelerate bone regeneration. Together, these findings suggest that low-intensity NIR light may promote in situ bone regeneration in a CRY1-dependent manner, providing a novel, efficient and non-invasive strategy to promote bone regeneration for clinical bone defects.

Synthetic poly-dioxolane as universal solid electrolyte interphase for stable lithium metal anodes

Lithium (Li) metal is a promising anode for the next generation high-energy–density batteries. However, the growth of Li dendrites, low coulombic efficiency and dramatic volume change limit its development. Here, we report a new synthetic poly-dioxolane (PDOL) approach to constructing an artificial 'elastic' SEI to stabilize the Li/electrolyte interface and the Li deposition/dissolution behavior in a variety of electrolytes. By coating PDOL with optimized molecular weights and synthetic routes on Li metal anode, the 'elastic' SEI layer could be maintained on top of the Li metal anode to accommodate the Li deposition/dissolution. No dendrite formation was observed during the cycling process, and the interfacial side reactions were reduced significantly. Consequently, we successfully achieved 330 cycles with a CE of 98.4% in ether electrolytes and 90 cycles with a CE of 94.3% in carbonate electrolytes. Simultaneously, the Li-metal batteries with LiFePO_(4) as cathodes also exhibited improved cycling performance. This strategy could promote the development of dendrite-free metal anodes toward high-performance Li-metal batteries.

The molecular conformation of silk fibroin regulates osteogenic cell behavior by modulating the stability of the adsorbed protein-material interface

Silk fibroin(SF)can be used to construct various stiff material interfaces to support bone formation.An essential preparatory step is to partially transform SF molecules from random coils toβ-sheets to render the material water insoluble.However,the influence of the SF conformation on osteogenic cell behavior at the material interface remains unknown.Herein,three stiff SF substrates were prepared by varying theβ-sheet content(high,medium,and low).The substrates had a comparable chemical composition,surface topography,and wettability.When adsorbed fibronectin was used as a model cellular adhesive protein,the stability of the adsorbed protein-material interface,in terms of the surface stability of the SF substrates and the accompanying fibronectin detachment resistance,increased with the increasingβ-sheet content of the SF substrates.Furthermore,(i)larger areas of cytoskeleton-associated focal adhesions,(ii)higher orders of cytoskeletal organization and(iii)more elongated cell spreading were observed for bone marrow-derived mesenchymal stromal cells(BMSCs)cultured on SF substrates with high vs.lowβ-sheet contents,along with enhanced nuclear translocation and activation of YAP/TAZ and RUNX2.Consequently,osteogenic differentiation of BMSCs was stimulated on highβ-sheet substrates.These results indicated that theβ-sheet content influences osteogenic differentiation of BMSCs on SF materials in vitro by modulating the stability of the adsorbed protein-material interface,which proceeds via protein-focal adhesion-cytoskeleton links and subsequent intracellular mechanotransduction.Our findings emphasize the role of the stability of the adsorbed protein-material interface in cellular mechanotransduction and the perception of stiff SF substrates with differentβ-sheet contents,which should not be overlooked when engineering stiff biomaterials.

Comparison of the Roles of Lymphatic Vessels and Blood Vessels in the Recurrence of Pterygia: A Retrospective Study

Purpose: Increased conjunctival arteries and lymphangions accelerate the cellular immune response in recurrent pterygium, however, which plays a more important role warrants further investigation. The aim of the study is to compare the roles of lymphatic and blood vessels in pterygium recurrence. Methods: Histological sections from 48 excised recurrent pterygia (including 14 Grade 1, 20 Grade 2, and 14 Grade 3 tissues) were examined. Histological sections from seven nasal epibulbar conjunctival segments served as normal controls. Blood and lymphatic vessels were evaluated and compared according to blood microvessel density (BMD), blood vascular area (BVA), lymphatic microvessel density (LMD), and lymph-vascular area (LVA). Furthermore, the following relationships were analyzed: LMD and pterygium recurrence time (RT), LVA and RT, BMD and RT, BVA and RT. Results: Compared to LVA, LMD, BVA, and BVD values in normal control tissues, these values were markedly enhanced in recurrent pterygia tissues. The LMD/BMD and LVA/BVA ratios were significant increased in Grade 2 and 3 recurrent pterygia, suggesting that development of conjunctival lymphangions was not proportional to blood vessel growth. LMD, LVA and BVA were significantly correlated with RT for all grades of pterygia, while BMD was the only factor correlated with RT in Grade 1 pterygia. Moreover, no significant correlation was found between BMD and RT in Grade 2 and 3 pterygia. Conclusion: Compared to blood vessels, lymphangions might have a greater impact on pterygium recurrence.

Performance Analysis of Multiband Impulse Radio UWB Communication System Based on PSWF

To improve the data transmission rate and use spectrum flexibly, a new spectrum allocation method for Multiband Impulse Radio UWB (MB-IR-UWB) is proposed in this paper based on the band-limited and orthogonal characteristics of Prolate Spheroidal Wave Function (PSWF). The system model is built and the bit error rate (BER) formula is deprived by binary time hopping pulse position modulation under additive white Gaussian noise. Moreover, the system performance is analyzed via MATLB simulation. The results indicate that MB-IR-UWB system performance of BER is the same with single-band UWB. However, in the proposed scheme the data can be transmitted in multiple parallel bands, which enjoys much higher transmission rate. In addition, PSWF pulse duration affects the BER performance.

Post-surgery multiple-site sampling procedure for the precise detection of microvascular invasion of hepatocellular carcinoma

Objective:Microvascular invasion(MVI)is an important risk factor for early recurrence after hepatectomy for hepatocellular carcinoma(HCC).However,it lacks the systemic evidence of the tissue sampling protocol for efficient MVI detection.This study aims to explore the relationship between the number of sampling sites(NuSS)crossing the tumor interface,the paracancerous parenchyma,and the positive rate of MVI.

Enlightenment of Cultural Innovation in the Park of China from the Park Development of U.S.A. and Singapore

This text combines authors＇ visits and examinations on the spot of Silicon Valley of U.S.A. and Park of Singapore, after analyzing the Park development experience of U.S.A. and Singapore, elucidates ＂three culture effects＂ of Park development in terms of cultural system emphatically, then proposes some suggestions of cultural innovation in the Park of China.

Fractionation and structural identification of antibiotic activity substances from <i>Streptomyces herbaricolor</i>HNS2-2

Four groups of antibiotic activity compounds were separated and purified from the ethyl acetate fraction of a broth culture of Streptomyces herbaricolor HNS2-2.Trace analyses were performed and anti-microbial activities were determined. The antibiotic activity compounds were identified as quercetin dehydrate ①, p-hydroxyphenyl ②, 4’-hydroxyflavanone ③, and 3-hydroxyflavone ④ based on spectroscopic data. Compounds 1-4 showed significant antimicrobial activities against Staphylococcus aureus and the tobacco mosaic virus in vitro, suggesting their potential agricultural and medical applications.

Relationship between FHIT Expression and HPV Status in Vulvar Squamous Cell Carcinomas

OBJECTIVE To investigate the relationship between fragilehistidine triad (FHIT) depletion and human papillomavirus (HPV)status in the vulvar squamous cell carcinomas (VSCC).METHODS Immunohistochemical method was used to detectthe expression of FHIT protein in 42 cases of VSCC and 10 casesof normal vulvar tissues. PCR was used to detect HPV infectionstatus. We analyzed the relationship of the expression of FHITprotein between the 2 groups: HPV positive and HPV negative, aswell as the clinically pathological characteristics.RESULTS The expression of FHIT was positive in all normal vul-var tissues, and 71.4% was depletion in VSCC (P < 0.01). Abnormalexpression of FHIT was significantly correlated with pathologicalgrade (P < 0.05). There was a significant difference between FHITdepletion and HPV infection based on the statistial analysis (P <0.05).CONCLUSION The FHIT depletion is related to occurrenceand development of VSCC, and the abnormal expression of FHITsignificantly correlates with HPV infection.

Diagnosis on the Problem of the Human Resources Management of State-owned Enterprises

With the reform of the state-owned enterprises, the level of the human resources management of a lot of state-owned enterprises has been gradually improved. However, because of the macroscopic system, history, culture and their own reasons, there are still a series of problems in the human resources management of state-owned enterprises. In order to promote the reform of state-owned enterprises and to improve the competitiveness of enterprises, we should critically research these urgent problems. The paper will take an example of one company which was investigated by state-owned enterprises will be listed and analysed. the author, and the common problems which exist in most state-owned enterprises will be listed and analysed.

The OsBZR1-OsSPX1/2 module fine-tunes the growth-immunity trade-off in adaptation to phosphate availability in rice

The growth-promoting hormones brassinosteroids(BRs)and their key signaling component BZR1 play a vital role in balancing normal growth and defense reactions.Here,we discovered that BRs and OsBZR1 up-regulated sakuranetin accumulation and conferred basal defense against Magnaporthe oryzae infection under normal conditions.Resource shortages,including phosphate(Pi)deficiency,potentially disrupt this growth-defense balance.OsSPX1 and OsSPX2 have been reported to sense Pi concentration and interact with the Pi signal mediator OsPHR2,thus regulating Pi starvation responses.In this study,we discovered that OsSPX1/2 interacts with OsBZR1 in both Pi-sufficient and Pi-deficient conditions,inhibit-ing BR-responsive genes.When Pi is sufficient,OsSPX1/2 is captured by OsPHR2,enabling most of OsBzR1 to promote plant growth and maintain basal resistance.In response to Pi starvation,more OsSPX1/2 is released from OsPHR2 to inhibit OsBZR1 activity,resulting in slower growth.Collectively,our study reveals that the OsBZR1-SPX1/2 module balances the plant growth-immunity trade-off in responsetoPiavailability.He Y.,Zhao Y.,Hu J.,Wang L.,Li L.,Zhang X.,Zhou Z.,Chen L.,Wang H.,Wang J.,and Hong G.(2024).The OsBZR1-OsSPX1/2 module fine-tunes the growth-immunity trade-off in adaptation to phosphate availability in esponse to Pi availability.

Bioceramic scaffolds with two-step internal/external modification of copper-containing polydopamine enhance antibacterial and alveolar bone regeneration capability

Magnesium-doped calcium silicate(CS)bioceramic scaffolds have unique advantages in mandibular defect repair;however,they lack antibacterial properties to cope with the complex oral microbiome.Herein,for the first time,the CS scaffold was functionally modified with a novel copper-containing polydopamine(PDA(Cu^(2+)))rapid deposition method,to construct internally modified(*P),externally modified(@PDA),and dually modified(*P@PDA)scaffolds.The morphology,degradation behavior,and mechanical properties of the obtained scaffolds were evaluated in vitro.The results showed that the CS*P@PDA had a unique micro-/nano-structural surface and appreciable mechanical resistance.During the prolonged immersion stage,the release of copper ions from the CS*P@PDA scaffolds was rapid in the early stage and exhibited long-term sustained release.The in vitro evaluation revealed that the release behavior of copper ions ascribed an excellent antibacterial effect to the CS*P@PDA,while the scaffolds retained good cytocompatibility with improved osteogenesis and angiogenesis effects.Finally,the PDA(Cu^(2+))-modified scaffolds showed effective early bone regeneration in a critical-size rabbit mandibular defect model.Overall,it was indicated that considerable antibacterial property along with the enhancement of alveolar bone regeneration can be imparted to the scaffold by the two-step PDA(Cu^(2+))modification,and the convenience and wide applicability of this technique make it a promising strategy to avoid bacterial infections on implants.

Traceless photodegradable polymer cocoons for universal protein delivery and light-controlled gene editing

Polymer conjugation was found highly valuable in clinic to improve the bioavailability of protein therapeutics.However,it is still a tremendous challenge to achieve a complete release of original proteins from the conjugated hybrid under external stimulus to recover active proteins in the targeted tissue.Herein,we report a general light-controlled protein delivery methodology by weaving a photodegradable polymer cocoon around proteins,which could reliably protect them from degradation in the dark while efficiently releasing them under illumination without any residual atoms.The surface charge of the polymer shell is easily tunable to facilitate efficient cell uptake.The versatility of this strategy is demonstrated by the delivery of the Cas9/sg RNA complex that realized light-controlled gene editing both in vitro and in vivo,and such repertoire is of particular value in regard to minimizing the off-target toxicity of CRISPR-Cas9-based gene therapy.