构筑开放锡位点实现酸性增强的二甲醚羰基化丝光沸石催化剂设计

Due to their tunable acidity,shape selectivity,and excellent stability,zeolites are of great importance as solid acid materials in industrial catalysis.Tuning the properties of the acid sites in zeolites allows for the rational design and fabrication of catalysts for target reactions.Dimethyl ether(DME)carbonylation,a critical chain-growth reaction for C1 resource utilization,is selectively catalyzed by the Brønsted acid sites within the eight-membered rings(8-MRs)of mordenite(MOR).It is anticipated that strengthening the Brønsted acidity—particularly in 8-MRs—will improve the catalytic performance of MOR.In this work,density functional theory(DFT)calculations are first employed and the results used to design a modified MOR with stannum(Sn)and to predict the corresponding changes in acidity.Guided by the theoretical studies,a series of Sn-modified MOR are synthesized via a defect-engineering and subsequent heteroatom-substitution strategy.After partial desilication,isolated tetrahedral Sn species in an open configuration are successfully synthesized for the first time,within which tetrahedrally coordinated Al sites are preserved.An acidic characterization is used to confirm that the acidity of the Brønsted acid sites is enhanced by the introduction of the Sn species;as a result,the sample exhibits excellent activity in DME carbonylation reaction.Kinetic and DFT studies reveal that this strengthened acidity facilitates the adsorption of DME and reduces the activation barriers of DME dissociation and acetyl formation,accounting for the improved activity.The work demonstrates mechanistic insights into the promoting effects of strong acidity on DME carbonylation and offers a promising strategy to precisely control the acidic strength of zeolites.

Effect of Jianpi Shengxue Tablet on Iron Metabolism and Nutritional Status in Patients with Renal Anemia:A Prospective,Randomized,Open,Parallel Controlled and Multicenter Clinical Study

Objective This study aimed to analyze the clinical efficacy of the Jianpi Shengxue tablet for treating renal anemia.Methods A total of 200 patients with renal anemia from December 2020 to December 2022 were enrolled and randomly divided into two groups.Patients in the control group were treated with polysaccharide-iron complex,and those in the experimental group were administered Jianpi Shengxue tablet.After 8 weeks of continuous treatment,the therapeutic outcomes regarding anemia were compared between the two groups.Results After treatment,the red blood cell(RBC)count,hematocrit(HCT),reticulocyte percentage(RET),ferritin(SF),serum iron(SI),transferrin saturation(TSAT),and serum albumin(ALB)all increased(P<0.01),and the clinical symptom score and total iron binding capacity decreased(P<0.01)in the experimental group.Moreover,the improvements in RBC,HCT,RET,SF,SI,TAST,ALB,and clinical symptoms(fatigue,anorexia,dull skin complexion,numbness of hands and feet)in the experimental group were significantly greater than those in the control group(P<0.05).The total effective rate for treating renal anemia was significantly higher in the experimental group than in the control group(P<0.01).Conclusion The Jianpi Shengxue tablet demonstrates efficacy in treating renal anemia,leading to significant improvements in the laboratory examination results and clinical symptoms of patients with renal anemia.

Mechanisms of tumor immunosuppressive microenvironment formation in esophageal cancer

As a highly invasive malignancy,esophageal cancer(EC)is a global health issue,and was the eighth most prevalent cancer and the sixth leading cause of cancerrelated death worldwide in 2020.Due to its highly immunogenic nature,emerging immunotherapy approaches,such as immune checkpoint blockade,have demonstrated promising efficacy in treating EC;however,certain limitations and challenges still exist.In addition,tumors may exhibit primary or acquired resistance to immunotherapy in the tumor immune microenvironment(TIME);thus,understanding the TIME is urgent and crucial,especially given the importance of an immunosuppressive microenvironment in tumor progression.The aim of this review was to better elucidate the mechanisms of the suppressive TIME,including cell infiltration,immune cell subsets,cytokines and signaling pathways in the tumor microenvironment of EC patients,as well as the downregulated expression of major histocompatibility complex molecules in tumor cells,to obtain a better understanding of the differences in EC patient responses to immunotherapeutic strategies and accurately predict the efficacy of immunotherapies.Therefore,personalized treatments could be developed to maximize the advantages of immunotherapy.

Latest insights into the global epidemiological features,screening,early diagnosis and prognosis prediction of esophageal squamous cell carcinoma

As a highly invasive carcinoma,esophageal cancer(EC)was the eighth most prevalent malignancy and the sixth leading cause of cancer-related death worldwide in 2020.Esophageal squamous cell carcinoma(ESCC)is the major histological subtype of EC,and its incidence and mortality rates are decreasing globally.Due to the lack of specific early symptoms,ESCC patients are usually diagnosed with advanced-stage disease with a poor prognosis,and the incidence and mortality rates are still high in many countries,especially in China.Therefore,enormous challenges still exist in the management of ESCC,and novel strategies are urgently needed to further decrease the incidence and mortality rates of ESCC.Although the key molecular mechanisms underlying ESCC pathogenesis have not been fully elucidated,certain promising biomarkers are being investigated to facilitate clinical decision-making.With the advent and advancement of highthroughput technologies,such as genomics,proteomics and metabolomics,valuable biomarkers with high sensitivity,specificity and stability could be identified for ESCC.Herein,we aimed to determine the epidemiological features of ESCC in different regions of the world,especially in China,and focused on novel molecular biomarkers associated with ESCC screening,early diagnosis and prognosis prediction.

Updates on global epidemiology,risk and prognostic factors of gastric cancer

Gastric cancer(GC)is defined as the primary epithelial malignancy derived from the stomach,and it is a complicated and heterogeneous disease with multiple risk factors.Despite its overall declining trend of incidence and mortality in various countries over the past few decades,GC remains the fifth most common malignancy and the fourth leading cause of cancer-related death globally.Although the global burden of GC has shown a significant downward trend,it remains severe in certain areas,such as Asia.GC ranks third in incidence and mortality among all cancer types in China,and it accounts for nearly 44.0%and 48.6%of new GC cases and GC-related deaths in the world,respectively.The regional differences in GC incidence and mortality are obvious,and annual new cases and deaths are increasing rapidly in some developing regions.Therefore,early preventive and screening strategies for GC are urgently needed.The clinical efficacies of conventional treatments for GC are limited,and the developing understanding of GC pathogenesis has increased the demand for new therapeutic regimens,including immune checkpoint inhibitors,cell immunotherapy and cancer vaccines.The present review describes the epidemiology of GC worldwide,especially in China,summarizes its risk and prognostic factors,and focuses on novel immunotherapies to develop therapeutic strategies for the management of GC patients.

Rapamycin reverses ferroptosis by increasing autophagy in MPTP/MPP+-induced models of Parkinson's disease

Parkinson’s disease is a neurodegenerative disorder,and fe rroptosis plays a significant role in the pathological mechanism underlying Parkinson’s disease.Rapamycin,an autophagy inducer,has been shown to have neuroprotective effects in Parkinson’s disease.However,the link between rapamycin and ferroptosis in Parkinson’s disease is not entirely clear.In this study,rapamycin was administe red to a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Parkinson’s disease mouse model and a 1-methyl-4-phenylpyridinium-induced Parkinson’s disease PC12 cell model.The results showed that rapamycin improved the behavioral symptoms of Parkinson’s disease model mice,reduced the loss of dopamine neurons in the substantia nigra pars compacta,and reduced the expression of ferroptosis-related indicators(glutathione peroxidase 4,recombinant solute carrier family 7,member 11,glutathione,malondialdehyde,and reactive oxygen species).In the Parkinson’s disease cell model,rapamycin improved cell viability and reduced ferro ptosis.The neuroprotective effect of rapamycin was attenuated by a ferroptosis inducer(methyl(1S,3R)-2-(2-chloroacetyl)-1-(4-methoxycarbonylphenyl)-1,3,4,9-tetrahyyridoindole-3-carboxylate)and an autophagy inhibitor(3-methyladenine).Inhibiting ferro ptosis by activating autophagy may be an important mechanism by which rapamycin exerts its neuroprotective effects.Therefo re,the regulation of ferroptosis and autophagy may provide a therapeutic target for drug treatments in Parkinson’s disease.

不同吻合位置在胸腹腔镜食管癌切除术中的应用

目的探讨不同吻合位置在胸腹腔镜联合食管癌(EC)切除手术中的应用效果及并发症发生情况。方法回顾性分析2012年3月-2017年4月该院336例EC手术患者,根据术中管状胃吻合口的位置分为前壁组、后壁组及侧壁组(胃底大弯侧)。总结3组术后吻合口瘘、吻合口狭窄及短期并发症发生率等,分析不同吻合位置对EC切除术后并发症的影响。结果 3组的吻合口狭窄、反流性食管炎比较,差异无统计学意义(P>0.05);侧壁组的吻合口瘘、残端或胸胃瘘及切口感染发生率低于前壁组和后壁组(P<0.05)。前壁组死亡5例(4.24%),后壁组死亡4例(3.77%),侧壁组死亡1例(0.89%);3组比较差异有统计学意义(P<0.05)。结论选择管状胃侧壁吻合有利于降低吻合口并发症的发生率,该技术能有效保证吻合口的安全性,特别是术后吻合口瘘、残端或胸胃瘘等,具有很好的推广应用价值。

Alteration of the esophageal microbiota in Barrett's esophagus and esophageal adenocarcinoma

The incidence of esophageal adenocarcinoma(EAC) has increased in recent decades, and its 5-year survival rate is less than 20%. As a well-established precursor, patients with Barrett's esophagus(BE) have a persistent risk of progression to EAC. Many researchers have already identified some factors that may contribute to the development of BE and EAC, and the identified risks include gastroesophageal reflux(GER), male sex, older age, central obesity,tobacco smoking, Helicobacter pylori(H. pylori) eradication, and the administration of proton pump inhibitors(PPIs) and antibiotics. The human gut harbors trillions of microorganisms, the majority of which are bacteria. These microorganisms benefit the human host in many ways, such as helping in digestion, assisting in the synthesis of certain vitamins, promoting the development of the gastrointestinal immune system, regulating metabolism and preventing invasion by specific pathogens. In contrast, microbial dysbiosis may play important roles in various diseases, such as inflammation and cancers. The composition of the microbiota located in the normal esophagus is relatively conserved without distinct microbial preferences in the upper, middle and lower esophagus. Six major phyla constitute the esophageal microbiota, including Firmicutes,Bacteroides, Actinobacteria, Proteobacteria, Fusobacteria and TM7, similar to the oral microbiota. Streptococcus dominates the esophageal microbiota. However, the microbiota varies in different esophageal diseases compared to that in the healthy esophagus. The type Ⅰ microbiota, which is primarily composed of gram-positive bacteria, is closely associated with the normal esophagus, while type Ⅱ microbiota has enriched gram-negative bacteria and is mainly associated with the abnormal esophagus. These increased gram-negative anaerobes/microaerophiles include Veillonella, Prevotella, Haemophilus, Neisseria, Granulicatella and Fusobacterium, many of which are associated with BE. The microbial diversity in the esophagus is decreased in EAC patients, and Lactobacillus fermentum is enriched compared to that in controls and BE patients. Furthermore, the microbiota may be associated with BE and EAC by interacting with their risk factors, including central obesity, GER, H. pylori, administration of PPIs and antibiotics. Therefore, a large gap in research must be bridged to elucidate the associations among these factors. Some studies have already proposed several potential mechanisms by which the microbiota participates in human carcinogenesis by complicated interactions with the human host immune system and signaling pathways. The activation of the LPS-TLR4-NF-κB pathway may contribute to inflammation and malignant transformation. This exciting field of gastrointestinal microbiota allows us to unravel the mystery of carcinogenesis from another perspective. Further studies are needed to explore whether the microbiota changes before or after disease onset, to improve our understanding of the pathogenesis, and to find novel targets for prevention, diagnosis and therapy, which could offer more cost-effective and relatively safe choices.

A Randomised Controlled PhaseⅡTrial of the Combination of XELOX with Thalidomide for the First-line Treatment of Metastatic Colorectal Cancer

Objective To evaluate the efficacy and safety of the combination of XELOX regimen(oxaliplatin plus capecitabine) with thalidomide for the first-line treatment of metastatic colorectal cancer(MCRC). Methods All of the 89 patients with MCRC who fulfilled eligibility criteria were randomly assigned to treatment group(n=44) and control group(n=45).The treatment group received a combination of XELOX with thalidomide and the control group received XELOX alone.Each patient received at least 2 cycles of treatment(1 cycle=21 d).The primary endpoint was progression-free survival(PFS) and the secondary endpoints were objective response rate(ORR) as well as disease control rate(DCR).Drug safety and quality of life were also assessed. Results The median PFS of the treatment and control groups were 5.6 and 5.2 months,respectively.The difference did not have a statistical significance(P=0.307).The ORRs of the two groups also had no statistical difference(34.1%vs.26.7%,P=0.446).The addition of thalidomide to XELOX significantly improved the DCR(63.6%vs.42.2%,P=0.043).Among 24 patients with hepatic metastasis in the treatment group,2 patients satisfied the surgical criteria after treatment but none of 23 patients in the control group did.Grade 3 or 4 constipation in patients treated with thalidomide was significantly increased(20.5%) vs.4.4%,P=0.022) but didn’t result in treatment interruption.The rate of lethargy was increased but the difference between the two groups had no statistical significance(13.6%vs. 4.4%,P=0.130).The quality of life had no statistical difference between the two groups. Conclusions The combination of XELOX with thalidomide for the first-line treatment of MCRC was well tolerated.Statistically significant improvement was achieved for the DCR but not for PFS.

Investigation of relationships among gastroesophageal reflux disease subtypes using narrow band imaging magnifying endoscopy

AIM:To investigate the relationships among subtypes of gastroesophageal reflux disease(GERD)using narrow band imaging(NBI)magnifying endoscopy.METHODS:A reflux disease questionnaire was used to screen 120 patients representing the three subtypes of GERD(n=40 for each subtypes):nonerosive reflux disease(NERD),reflux esophagitis(RE)and Barrett’s esophagus(BE).NBI magnifying endoscopic procedure was performed on the patients as well as on 40 healthy controls.The demographic and clinical characteristics,and NBI magnifying endoscopic features,were recorded and compared among the groups.Targeted biopsy and histopathological examination were conducted if there were any abnormalities.SPSS 18.0 software was used for all statistical analysis.RESULTS:Compared with healthy controls,a significantly higher proportion of GERD patients had increased number of intrapapillary capillary loops(IPCLs)(78.3%vs 20%,P<0.05),presence of microerosions(41.7%vs 0%,P<0.05),and a non-round pit pattern below the squamocolumnar junction(88.3%vs 30%,P<0.05).The maximum(228±4.8 vs 144±4.7,P<0.05),minimum(171±3.8 vs 103±4.4,P<0.05),and average(199±3.9 vs 119±3.9,P<0.05)numbers of IPCLs/field were also significantly greater in GERD patients.However,comparison among groups of the three subtypes showed no significant differences or any linear trend,except that microerosions were present in 60%of the RE patients,but in only 35%and 30%of the NERD and BE patients,respectively(P<0.05).CONCLUSION:Patients with GERD,irrespective of subtype,have similar micro changes in the distal esophagus.The three forms of the disease are probably independent of each other.

Bioinformatics analyses of differentially expressed genes associated with spinal cord injury:a microarray-based analysis in a mouse model

Gene spectrum analysis has shown that gene expression and signaling pathways change dramatically after spinal cord injury,which may affect the microenvironment of the damaged site.Microarray analysis provides a new opportunity for investigating diagnosis,treatment,and prognosis of spinal cord injury.However,differentially expressed genes are not consistent among studies,and many key genes and signaling pathways have not yet been accurately studied.GSE5296 was retrieved from the Gene Expression Omnibus DataSet.Differentially expressed genes were obtained using R/Bioconductor software(expression changed at least two-fold;P < 0.05).Database for Annotation,Visualization and Integrated Discovery was used for functional annotation of differentially expressed genes and Animal Transcription Factor Database for predicting potential transcription factors.The resulting transcription regulatory protein interaction network was mapped to screen representative genes and investigate their diagnostic and therapeutic value for disease.In total,this study identified 109 genes that were upregulated and 30 that were downregulated at 0.5,4,and 24 hours,and 3,7,and 28 days after spinal cord injury.The number of downregulated genes was smaller than the number of upregulated genes at each time point.Database for Annotation,Visualization and Integrated Discovery analysis found that many inflammation-related pathways were upregulated in injured spinal cord.Additionally,expression levels of these inflammation-related genes were maintained for at least 28 days.Moreover,399 regulation modes and 77 nodes were shown in the protein-protein interaction network of upregulated differentially expressed genes.Among the 10 upregulated differentially expressed genes with the highest degrees of distribution,six genes were transcription factors.Among these transcription factors,ATF3 showed the greatest change.ATF3 was upregulated within 30 minutes,and its expression levels remained high at28 days after spinal cord injury.These key genes screened by bioinformatics tools can be used as biological markers to diagnose diseases and provide a reference for identifying therapeutic targets.

Biomarker identification and trans-regulatory network analyses in esophageal adenocarcinoma and Barrett's esophagus

BACKGROUND Esophageal adenocarcinoma(EAC) is an aggressive disease with high mortality and an overall 5-year survival rate of less than 20%. Barrett's esophagus(BE) is the only known precursor of EAC, and patients with BE have a persistent and excessive risk of EAC over time. Individuals with BE are up to 30-125 times more likely to develop EAC than the general population. Thus, early detection of EAC and BE could significantly improve the 5-year survival rate of EAC. Due to the limitations of endoscopic surveillance and the lack of clinical risk stratification strategies, molecular biomarkers should be considered and thoroughly investigated.AIM To explore the transcriptome changes in the progression from normal esophagus(NE) to BE and EAC.METHODS Two datasets from the Gene Expression Omnibus(GEO) in NCBI Database(https://www.ncbi.nlm.nih.gov/geo/) were retrieved and used as a training and a test dataset separately, since NE, BE, and EAC samples were included and the sample sizes were adequate. This study identified differentially expressed genes(DEGs) using the R/Bioconductor project and constructed trans-regulatory networks based on the Transcriptional Regulatory Element Database and Cytoscape software. Enrichment of Kyoto Encyclopedia of Genes and Genomes(KEGG) and Gene Ontology(GO) terms was identified using the Database for Annotation, Visualization, and Integrated Discovery(DAVID) Bioinformatics Resources. The diagnostic potential of certain DEGs was assessed in both datasets.RESULTS In the GSE1420 dataset, the number of up-regulated DEGs was larger than that of down-regulated DEGs when comparing EAC vs NE and BE vs NE. Among these DEGs, five differentially expressed transcription factors(DETFs) displayed the same trend in expression across all the comparison groups. Of these five DETFs,E2 F3, FOXA2, and HOXB7 were up-regulated, while PAX9 and TFAP2 C were down-regulated. Additionally, the majority of the DEGs in trans-regulatory networks were up-regulated. The intersection of these potential DEGs displayed the same direction of changes in expression when comparing the DEGs in the GSE26886 dataset to the DEGs in trans-regulatory networks above. The receiver operating characteristic curve analysis was performed for both datasets and found that TIMP1 and COL1 A1 could discriminate EAC from NE tissue, while REG1 A, MMP1, and CA2 could distinguish BE from NE tissue. DAVID annotation indicated that COL1 A1 and MMP1 could be potent biomarkers for EAC and BE, respectively, since they participate in the majority of the enriched KEGG and GO terms that are important for inflammation and cancer.CONCLUSION After the construction and analyses of the trans-regulatory networks in EAC and BE, the results indicate that COL1 A1 and MMP1 could be potential biomarkers for EAC and BE, respectively.

Novel Method for Preparing a Carbon Nanotube-Supported Cobalt Catalyst for Fischer–Tropsch Synthesis:Hydrogen Dielectric-Barrier Discharge Plasma

Hydrogen dielectric-barrier discharge(H_2-DBD)plasma was successfully used to prepare carbon nanotubes(CNTs)-supported cobalt(Co) catalyst.The H_2-DBD plasma treatment simultaneously decomposed and reduced the cobalt precursor at a lower temperature and in a shorter time than the conventional method(calcination and hydrogen reduction).It is considered that the H_2-DBD plasma method can remarkably decrease the amount of energy input compared to traditional methods used to prepare the Co-based catalyst in Fischer-Tropsch synthesis(FTS).Results showed that the Co catalyst prepared by H_2-DBD plasma had an equivalent catalytic performance for FTS as that prepared using the conventional method in calcination and hydrogen reduction,thereby determining that H_2-DBD plasma was an effective alternative treatment for preparing the Co/CNTs catalyst for FTS.This technology will provide a new strategy for preparing catalysts in other catalysis processes.

Highly dispersed nickel boosts catalysis by Cu/SiO_(2) in the hydrogenation of CO_(2)-derived ethylene carbonate to methanol and ethylene glycol

The efficient hydrogenation of CO_(2)-derived ethylene carbonate(EC)to yield methanol(MeOH)and ethylene glycol(EG)is a key process for indirect conversion of CO_(2)to MeOH.However,a high H_(2)/EC molar ratio during the hydrogenation process(usually as 180-300)is generally required to achieve good catalytic performance,resulting in high cost and energy consumption for H_(2)circulation in the promising industrial application.Here,we prepared a series of Ni-modified Cu/SiO_(2)catalysts and explored the effects of synthesis methods and Ni contents on catalytic performance under different H_(2)/EC molar ratios.The Cu/SiO_(2)catalyst with 0.2%(mass)Ni loading prepared by co-ammonia evaporation method exhibited above 99%conversion of EC,91%and 98%selectivity to MeOH and EG respectively at H_(2)/EC ratio of 60.And no significant deactivation was observed within 140 h at a lower H_(2)/EC of 40.It is demonstrated that a few of Ni addition could not only promote Cu dispersion and increase surface Cu^(+) species due to the strong interaction between Cu and Ni species,but also form uniformly-dispersed CuNi alloy species and thus enhance the adsorption and dissociation of H_(2).But the excess Ni species would aggregate and segregate to cover partial surface of Cu nanoparticles,leading to a significantly drop of catalytic performance in EC hydrogenation.These insights may provide guidance for further design of catalysts for the ester hydrogenation reactions.

Controllable synthesis of core-shell Co@C@SiO2 catalysts for enhancing product selectivity in Fischer-Tropsch synthesis by tuning the mass transfer resistance

Fischer-Tropsch synthesis(FTS) is the key step in converting syngas into clean fuels. Traditional supported catalysts for FTS are problematic because the active metal crystalline size is positively related to metal loading. Therefore, increasing active metal loading may reduce the cobalt time yield(CTY) since a high CTY is usually obtained when the Co size is 8 nm. Here, a ZIF-67(Zeolitic imidazolate framework-67) with a MOF(Metal organic framework) structure is used as a precursor to prepare the Co@C catalyst with not only high cobalt loading(55.6 wt%) but also with a small cobalt crystal size(as small as 8.6 nm). Coreshell Co@C@SiO2-X catalysts with different SiO2 shell thicknesses were successfully prepared by coating different amounts of TEOS on the outer surface of Co@C to modify product selectivity. Compared with40 wt% Co/SiO2 catalyst, core-shell Co@C@SiO2-X catalysts exhibited improved FTS performance. Furthermore, different gaseous hourly space velocities(GHSVs) were used to obtain CO conversion at similar levels to compare CTY and the turnover frequency(TOF). Among the catalysts, the Co@C@SiO2-1 catalyst, with its better mass transfer ability and suitable hydrophilic property, presented the highest TOF(9.75 × 10-3 s-1) and lowest CH4 selectivity(9.75%). In addition, heavy hydrocarbons were effectively suppressed with the increase in shell thickness due to the increased mass transfer resistance.

Kinetics Modeling of Calcium Formate Synthesis by Calcium Hydroxide Carbonylation

The synthesis of calcium formate by Ca(OH)_2 carbonylation was studied in a semi-batch stirred tank.The reaction mechanism was analyzed theoretically and the rate of each step was compared.The influence ofreaction conditions on the formation of calcium formate was investigated.The results indicate that the rate-controlling step is the reaction between dissolved CO and dissolved Ca(OH)_2,and the gaseous diffusion resistance can be eliminated when the stirring speed reached 1000 r/min.Furthermore,the reaction kinetics was studied at a stirring speed of 1000 r/min,temperature of 423–453 K,pressure of 2.0–3.5 MPa and different initial concentrations of Ca(OH)_2.An effective method was proposed to measure the reaction rate of CO.A mathematical model was developed using the dual-film theory,and the parameters were obtained using regression of experimental data.The reaction rates calculated using the kinetics model were compared with experimental data.The results show that the deviations are within ±10%,proving that the established model is valid and can provide a basis for industrial amplification.

Bilayer tellurene-metal interfaces

Tellurene, an emerging two-dimensional chain-like semiconductor, stands out for its high switch ratio, carrier mobility and excellent stability in air. Directly contacting the 2D semiconductor materials with metal electrodes is a feasible doping means to inject carriers. However, Schottky barrier often arises at the metal–semiconductors interface, impeding the transport of carriers. Herein, we investigate the interfacial properties of BL tellurene by contacting with various metals including graphene by using ab initio calculations and quantum transport simulations. Vertical Schottky barriers take place in Ag, Al, Au and Cu electrodes according to the maintenance of the noncontact tellurene layer band structure. Besides, a p-type vertical Schottky contact is formed due to the van der Waals interaction for graphene electrode. As for the lateral direction, p-type Schottky contacts take shape for bulk metal electrodes(hole Schottky barrier heights(SBHs) ranging from 0.19 to 0.35 eV). Strong Fermi level pinning takes place with a pinning factor of 0.02. Notably, a desirable p-type quasi-Ohmic contact is developed for graphene electrode with a hole SBH of 0.08 eV. Our work sheds light on the interfacial properties of BL tellurene based transistors and could guide the experimental selections on electrodes.

Pt-modulated Cu/SiO_(2) catalysts for efficient hydrogenation of CO_(2)-derived ethylene carbonate to methanol and ethylene glycol

Copper-based catalysts were widely used in the heterogeneous selective hydrogenation of ethylene carbonate(EC),a key step in the indirect conversion of CO_(2) to methanol.However,a high H_(2)/EC molar ratio in feed is required to achieve favorable activity and the methanol selectivity still needs to be improved.Herein,we fabricated a series of Pt-modulated Cu/SiO_(2) catalysts and investigated their catalytic performance for hydrogenation of EC in a fixed bed reactor.By modulating the Pt amount,the optimal 0.2Pt-Cu/SiO_(2) catalyst exhibited the highest catalytic performance with99%EC conversion,over 98%selectivity to ethylene glycol and 95.8%selectivity to methanol at the H_(2)/EC ratio as low as 60 in feed.In addition,0.2Pt-Cu/SiO_(2) catalyst showed excellent stability for 150 h on stream over different H_(2)/EC ratios of 180-40.It is demonstrated a proper amount of Pt could significantly lower the H_(2)/EC molar ratio,promote the reducibility and dispersion of copper,and also enhance surface density of Cu+species.This could be due to the strong interaction of Cu and Pt induced by formation of alloyed Pt single atoms on the Cu lattice.Meanwhile,a relatively higher amount of Pt would deteriorate the catalytic activity,which could be due to the surface coverage and aggregation of active species.These findings may enlighten some fundamental insights for further design of Cu-based catalysts for the hydrogenation of carbon–oxygen bonds.

Flame-retarding battery cathode materials based on reversible multi-electron redox chemistry of phenothiazine-based polymer

Polymeric organic battery materials are promising alternatives to the transition-metal-based ones owing to their enriched chemistries. However, the flammability of organic compounds brings in serious concern on battery safety. In addition to use flame-retarding electrolyte/electrolyte additives or battery separators,flame retardancy can readily be achieved through the integration of flame-retarding unit into the polymer backbone, imparting the flame retardancy permanently. The as-designed polymer based on phenothiazine shows significantly shortened self-extinguished time without deteriorating its intrinsic thermodynamic and electrochemical properties. Moreover, two electron per phenothiazine molecule is realized for the first time in a highly reversible manner with discharge voltages of 3.52 V and 4.16 V versus Li+/Li and an average capacity of ca. 120 mAh g-1 at a current rate of 2 C. The origin of the reversibility is investigated through density functional theory(DFT) calculations. These findings address the importance of molecular design for safer and more stable organic materials for batteries.

Associations of gut microbiota with dyslipidemia based on sex differences in subjects from Northwestern China

BACKGROUND The gut microbiota(GM)has been proven to play a role in the regulation of host lipid metabolism,which provides a new theory about the pathogenesis of dyslipidemia.However,the associations of GM with dyslipidemia based on sex differences remain unclear and warrant elucidation.AIM To investigate the associations of GM features with serum lipid profiles based on sex differences in a Chinese population.METHODS This study ultimately recruited 142 participants(73 females and 69 males)at Honghui Hospital,Xi’an Jiaotong University.The anthropometric and blood metabolic parameters of all participants were measured.According to their serum lipid levels,female and male participants were classified into a high triglyceride(H_TG)group,a high total cholesterol(H_CHO)group,a low high-density lipoprotein cholesterol(L_HDL-C)group,and a control(CON)group with normal serum lipid levels.Fresh fecal samples were collected for 16S rRNA gene sequencing.UPARSE software,QIIME software,the RDP classifier and the FAPROTAX database were used for sequencing analyses.RESULTS The GM composition at the phylum level included Firmicutes and Bacteroidetes as the core GM.Different GM features were identified between females and males,and the associations between GM and serum lipid profiles were different in females and males.The GM features in different dyslipidemia subgroups changed in both female patients and male patients.Proteobacteria,Lactobacillaceae,Lactobacillus and Lactobacillus_salivarius were enriched in H_CHO females compared with CON females,while Coriobacteriia were enriched in L_HDL-C females.In the comparison among the three dyslipidemia subgroups in females,Lactobacillus_salivarius were enriched in H_CHO females,and Prevotellaceae were enriched in L_HDL-C females.Compared with CON or H_TG males,Prevotellaceae,unidentified_Ruminococcaceae,Roseburia and Roseburia_inulinivorans were decreased in L_HDL-C males(P value<0.05),and linear discriminant analysis effect size analysis indicated an enrichment of the above GM taxa in H_TG males compared with other male subgroups.Additionally,Roseburia_inulinivorans abundance was positively correlated with serum TG and total cholesterol levels,and Roseburia were positively correlated with serum TG level.Furthermore,Proteobacteria(0.724,95%CI:0.567-0.849),Lactobacillaceae(0.703,95%CI:0.544-0.832),Lactobacillus(0.705,95%CI:0.547-0.834)and Lactobacillus_salivarius(0.706,95%CI:0.548-0.835)could distinguish H_CHO females from CON females,while Coriobacteriia(0.710,95%CI:0.547-0.841),Coriobacteriales(0.710,95%CI:0.547-0.841),Prevotellaceae(0.697,95%CI:0.534-0.830),Roseburia(0.697,95%CI:0.534-0.830)and Roseburia_inulinivorans(0.684,95%CI:0.520-0.820)could discriminate H_TG males from CON males.Based on the predictions of GM metabolic capabilities with the FAPROTAX database,a total of 51 functional assignments were obtained in females,while 38 were obtained in males.This functional prediction suggested that cellulolysis increased in L_HDL-C females compared with CON females,but decreased in L_HDL-C males compared with CON males.CONCLUSION This study indicates associations of GM with serum lipid profiles,supporting the notion that GM dysbiosis may participate in the pathogenesis of dyslipidemia,and sex differences should be considered.