Precise regulation of pyrrole-type single-atom Mn-N4 sites for superior pH-universal oxygen reduction

The study of atomically dispersed metal-nitrogen electrocatalysts is still limited in terms of understanding their catalytic mechanism because of the inability to precisely regulate the coordination number and type of N in combination with the metal elements.Inspired by the high catalytic activity and selectivity of natural enzymes,herein,we have designed and fabricated ultrathin carbon nanosheet-supported Mn single-atom catalysts(SACs)with a precise pyrrole-type Mn-N4(PT-MnN4)configuration using a bio-mimicking strategy.The PT-MnN4 SACs display outstanding oxygen reduction reaction(ORR)activity,with a half-wave potential(E_(1/2))of 0.88 V(vs.revisible hydrogen electrode[RHE])and extremely high stability in alkaline media.Moreover,superior ORR activities are also obtained,E_(1/2) of 0.73 V and 0.63 V in acid and neutral electrolytes,respectively,indicating the efficient pH-universal ORR performances.The assembled zinc-air battery using the PT-MnN4 SACs as air cathodes exhibits a high peak power density(175 mW cm^(−2))and long-term stability up to 150 h,implying its promising application in metal-air batteries.This study has paved the way toward the rational design and precise regulation of single-atom electrocatalysts.

Abnormal expression of VEGF and its gene transcription status as diagnostic indicators in patients with non-small cell lung cancer

Objective Angiogenesis is known to be essential for the survival,growth,invasion,and metastasis of lung cancer cells. Vascular endothelial growth factor(VEGF) is an important factor regulating angiogenesis of non-small cell lung cancer(NSCLC); however,its pathologic features and significance are unclear. In this study,the tissue VEGF expression levels and its gene transcriptional status,as well as circulating VEGF levels,were investigated in patients with lung disease. Methods VEGF protein and m RNA expression levels in 38 lung tissue samples were analyzed by immunohistochemistry and reverse transcription-polymerase chain reaction(RT-PCR),respectively. Circulating VEGF levels were detected quantitatively by an enzyme linked immuno-sorbent assay. Results The level of VEGF expression was significantly higher in lung cancer tissue than in the corresponding paracancerous or non-cancerous tissues. The average level of VEGF-positive staining was 76% in tissue samples from NSCLC patients; the levels were 89% in tissue samples from stage III patients and 92% in stage IV patients. High VEGF expression was also evident in cases with lymph node metastasis(84%),distant metastasis(90%),and lower differentiation degree(89%). VEGF m RNA in cancerous tissues was represented predominantly by the VEGF121 and VEGF165 isoforms. Circulating VEGF levels were significantly higher in NSCLC patients [(840 ± 324) pg/m L] than in patients with benign lung diseases [(308 ± 96) pg/m L] or in healthy individuals serving as controls [(252 ± 108) pg/m L]. Conclusion The over-expression of lung VEGF and its gene transcription status should be useful molecular indicators for NSCLC diagnosis.

Visible photoluminescence of polyoxoniobates in aqueous solution and their high electrocatalytic activities for water oxidation

The photoluminescence of four polyoxoniobates [Nb6O19]8-, [Nb10O28]6-, [Ti2Nb8O28]8- and [H2Si4Nb16O56]14- was observed, and its origin was revealed in the view of molecular orbital by means of the computational method. The photoluminescence is originated from singlet transitions, and the calculated values agree well with the experimental data. The results indicate that the size of clusters and the foreigner atoms can affect the fluorescent properties of PONbs. The absorption and emission of these PONbs are originated molecular orbitals contributed mainly by μ2-O and Nb atoms according to NBO analysis. These PONbs were also found as electrochemical catalysts with high performance for water oxidation, which can effectively split water into oxygen under basic condition with a high catalytic current, and pH values have remarkable influence on the electrocatalytic activities of these PONbs for water oxidation.

Research Progress on the <i>Actinomyces arthrobacter</i>

The genus Arthrobacter was established in 1947 by Conn & Dimmick. So far, more than 70 recognized?species of the genus Arthrobacter have been certified. Its special functions have been widely known by researchers, such as, in agricultural, in medical, in industrial, and in environmental areas, etc. What deserves to be mentioned is that some species of genus Arthrobacter have showed the function of degrading pesticides, fixing nitrogen, producing beneficial enzyme, treating sewage, and so on. Recently, the applications of the genus Arthrobacter, especially the VBNC?(viable but non-culturable) bacteria of this genus in the field of contaminated environment repair attract people’s attention and some related research results have also been obtained. The functions that we have known are waiting for us to study about mechanism, deeply. And, we can look forward to discovering more potential functions and applications of this genus in ecological environment. In the meantime, these discoveries must bring more new changes and knowledge.

以急诊重症监护病房为救治平台的省级创伤中心建设模式探讨

不同医院采取适合于自身的创伤中心模式有助于建设高效的创伤救治体系。笔者结合本院省级创伤中心建设情况,从创伤中心建设的背景和模式、以急诊和EICU为创伤救治平台的优势、创伤中心建设中的团队培养、信息化发展、创伤救治质量持续改进等方面进行总结和探讨,为创伤中心的发展提供借鉴。

床旁超声指导下控制性液体复苏在创伤失血性休克中的应用

创伤失血性休克(traumatic hemorrhagic shock,HTS)在创伤患者死亡中占据主要因素,而HTS的基础治疗就是液体复苏。如何正确且及时地进行液体复苏,最大限度降低并发症的发生就是关键。近年来,床旁超声由于具有无创检查、快速直观、可靠且便于操作的特性,在临床HTS患者救治中被越来越多的采用。通过床旁超声评估HTS患者的容量及容量反应性、心功能及肺水肿的情况,来指导患者的液体复苏治疗,针对HTS的不同时期,根据患者的自身情况制定个性化的液体治疗方案,以此减少创伤后液体复苏过程中并发症的发生,缩短住院时间及改善预后。

Biochar-based materials and their applications in removal of organic contaminants from wastewater:state-of-the-art review

As a class of famous carbon materials,biochars(BCs)and their derivative materials with excellent physicochemical properties and diversified functionalities present great potential in wastewater treatment fields.This review focuses on the latest development in reported biochar-based materials as superior adsorbents or catalysts for removing harmful organic contaminants from wastewater.The construction and properties of biochar-based materials are briefly introduced at the beginning.As one of the major factors affecting the properties of BCs,the wide diversity of feedstocks,such as agricultural and forest residues,industrial by-products as well as municipal wastes,endows BCs different chemical compositions and structures.Woody and herbaceous BCs usually have higher carbon contents,larger surface areas and strong aromaticity,which is in favor of the organic contaminant removal.Driven by the desire of more cost-effective materials,several types of biochar-based hybrid materials,such as magnetic BC composites(MBC),nanometal/nanometallic oxides/hydroxide BC composites and layered nanomaterial-coated BCs,as well as physically/chemically activated BCs,have also been developed.With the help of foreign materials,these types of hybrid BCs have excellent capacities to remove a wide range of organic contaminants,including organic dyestuff,phenols and chemical intermediates,as well as pharmaceutically active compounds,from aquatic solutions.Depending on the different types of biochar-based materials,organic contaminants can be removed by different mechanisms,such as physical adsorption,electrostatic interaction,π-πinteraction and Fenton process,as well as photocatalytic degradation.In summary,the low cost,tunable surface chemistry and excellent physical-chemical properties of BCs allow it to be a potential material in organic contaminant removal.The combination of BCs with foreign materials endows BCs more functionalities and broader development opportunities.Considering the urgent demand of practical wastewater treatment,we hope more researches will focus on the applications and commercialization of biochar-based materials.

Application of biochar-based photocatalysts for adsorption-(photo)degradation/reduction of environmental contaminants:mechanism,challenges and perspective

The fast increase of population results in the quick development of industry and agriculture.Large amounts of contaminants such as metal ions and organic contaminants are released into the natural environment,posing a risk to human health and causing environment ecosystem problems.The efficient elimination of contaminants from aqueous solutions,photocatalytic degradation of organic pollutants or the in-situ solidification/immobilization of heavy metal ions in solid phases are the most suitable strategies to decontaminate the pollution.Biochar and biochar-based composites have attracted multidisciplinary interests especially in environmental pollution management because of their porous structures,large amounts of functional groups,high adsorption capacities and photocatalysis performance.In this review,the application of biochar and biochar-based composites as adsorbents and/or catalysts for the adsorption of different contaminants,adsorption-photodegradation of organic pollutants,and adsorption-(photo)reduction of metal ions are summarized,and the mechanism was discussed from advanced spectroscopy analysis and DFT calculation in detail.The doping of metal or metal oxides is the main strategy to narrow the band gap,to increase the generation and separation of photogenerated e−-h+pairs,to produce more superoxide radicals(·O_(2)^(−))and hydroxyl radicals(·OH),to enhance the visible light absorption and to increase photocatalysis performance,which dominate the photocatalytic degradation of organic pollutants and(photo)reduction of high valent metals to low valent metals.The biochar-based composites are environmentally friendly materials,which are promising candidates in environmental pollution cleanup.The challenge and perspective for biochar-based catalysts are provided in the end.

A simplex method for the orbit determination of maneuvering satellites

simplex method;;orbit determination;;electric propulsion;;orbit