Mo改性Pd/NaY催化剂用于甲醇间接氧化羰基化合成碳酸二甲酯

碳酸二甲酯(DMC)因具有较好的溶解性、生物降解性和低毒性,而被认为是一种绿色化学品.其用途广泛,不仅用于合成聚碳酸酯,还是锂离子电池电解液、燃料添加剂以及羰基化和甲基化反应的重要试剂.在众多合成方法中,CH_(3)OH间接氧化羰基化合成DMC,具有无爆炸风险、反应条件温和以及原子经济性高等优点,因而展现出广阔的应用前景.然而,这一过程中使用的无氯Pd/NaY催化剂存在以下问题:Pd2+活性物种容易被反应物CO还原成Pd0物种,导致Pd烧结和催化剂失活.因此,如何在催化过程中保持Pd2+物种的稳定,是当前面临的一个重要挑战.本文采用“自上而下”的方法,制备了Mo改性的Pd/NaY催化剂(Pd-Mo/NaY).该催化剂在保持贵金属Pd氧化态的同时,增强了对反应物CO的吸附能力,进而提高了催化剂的稳定性.在CH_(3)OH间接氧化羰基化制DMC反应中,Pd-Mo/NaY表现出比Pd/NaY催化剂更高的催化活性和稳定性.在30 h的反应过程中,Pd-Mo/NaY催化剂上的CO转化率稳定维持在约97%,而Pd/NaY催化剂上的CO转化率则从94%逐渐下降至70%.此外,Pd-Mo/NaY催化剂的本征活性(TOF)为0.019 s^(-1),也明显高于Pd/NaY催化剂的0.005 s^(-1).X射线衍射、物理吸附和扫描电镜结果表明,Mo改性未显著改变Pd/NaY的物相结构、孔结构性质与微观形貌.透射电镜与扫描电镜能谱结果表明,两个催化剂的Pd聚集状态存在显著差异.Pd/NaY催化剂中Pd物种发生了明显聚集,Pd颗粒平均尺寸达到10.2 nm;而Pd-Mo/NaY催化剂中,大部分Pd物种仍保持高度分散的状态,仅有少量聚集的Pd颗粒,其平均尺寸仅为2.3 nm.通过羟基红外、吡啶红外与氨气程序升温脱附表征技术进一步研究了催化性能与Pd聚集状态差异的原因.结果表明,Mo的引入有效减少了因Pd离子交换过程引入的桥式羟基,从而降低了Pd-Mo/NaY催化剂的酸性.此外,氢气程序升温还原与X射线光电子能谱结果进一步揭示,Pd与Mo之间的相互作用调变了Pd-Mo/NaY的活性位结构,阻碍了活性Pd^(2+)物种被反应物CO还原为Pd0物种,从而有效缓解了Pd物种的聚集.CO漫反射红外与CO低温透射红外研究则表明,Pd-Mo之间的相互作用以及Pd2+活性位点的增加,显著增强了催化剂对反应物CO的吸附能力.通过原位漫反射红外(DRIFTS)实验捕获了COOCH_(3)*关键反应中间体,并发现无论是Pd/NaY催化剂还是Mo改性的Pd-Mo/NaY催化剂,均遵循相似的反应路径,并具有相同的决速步骤.综上,本文通过Mo对Pd/NaY催化剂进行改性,有效抑制了反应过程中贵金属Pd的烧结,从而显著提高Pd-Mo/NaY催化剂的稳定性.通过这一改性方法,实现了活性Pd2+物种的高度稳定,为甲醇间接氧化羰基化制DMC催化剂的研发提供了新思路.

BoMyrosinase plays an essential role in sulforaphane accumulation in response to selenite treatment in broccoli

Sulforaphane, a naturally specialized metabolite, plays significant roles in human disease prevention and plant defense. Myrosinase(MY) is a key gene responsible for the catalysis of sulforaphane formation, but the molecular mechanisms through which MY regulates sulforaphane biosynthesis in plants remains largely unknown. Here, we discovered that the change of sulforaphane content in broccoli sprouts caused by exogenous selenite treatments is positively related to BoMY expression. BoMY overexpression in the Arabidopsis thaliana tgg1 mutants could dramatically increase myrosinase activity and sulforaphane content in the rosette leaves of 35S::BoMY/tgg1 and rescue its phenotypes.Moreover, an obvious increase of myrosinase activity and sulforaphane content was displayed in transgenic BoMY-overexpressed broccoli lines.In addition, a 2 033 bp promoter fragment of BoMY was isolated. Yeast one-hybrid(Y1H) library screening experiment uncovered that one bHLH transcription factor, BoFAMA, could directly bind to BoMY promoter to activate its expression, which was further evidenced by Y1H assay and dual-luciferase reporter assay. BoFAMA is a selenite-responsive transcription factor that is highly expressed in broccoli leaves;its protein is solely localized to nucleus. Additionally, genetic evidence suggested that the knockdown of FAMA gene in Arabidopsis thaliana could significantly decrease sulforaphane yield by inhibiting the expression of myrosinase genes. Interestingly, exogenous selenite supply could partially restore the low level of sulforaphane content in transgenic Arabidopsis FAMA-silencing plants. Our findings uncover a novel function of FAMAMY module in the regulation of selenite-mediated sulforaphane synthesis and provide a new insights into the molecular mechanism by which selenite regulates the accumulation of sulforaphane in plants.

LncRNA IDH1-AS1 sponges miR-518c-5p to suppress proliferation of epithelial ovarian cancer cell by targeting RMB47

Long noncoding RNA(lncRNA)IDH1 antisense RNA 1(IDH1-AS1)is involved in the progression of multiple cancers,but its role in epithelial ovarian cancer(EOC)is unknown.Therefore,we investigated the expression levels of IDH1-AS1 in EOC cells and normal ovarian epithelial cells by quantitative real-time PCR(qPCR).We first evaluated the effects of IDH1-AS1 on the proliferation,migration,and invasion of EOC cells through cell counting kit-8,colony formation,EdU,transwell,wound-healing,and xenograft assays.We then explored the downstream targets of IDH1-AS1 and verified the results by a dual-luciferase reporter,qPCR,rescue experiments,and Western blotting.We found that the expression levels of IDH1-AS1 were lower in EOC cells than in normal ovarian epithelial cells.High IDH1-AS1 expression of EOC patients from the Gene Expression Profiling Interactive Analysis database indicated a favorable prognosis,because IDH1-AS1 inhibited cell proliferation and xenograft tumor growth of EOC.IDH1-AS1 sponged miR-518c-5p whose overexpression promoted EOC cell proliferation.The miR-518c-5p mimic also reversed the proliferation-inhibiting effect induced by IDH1-AS1 overexpression.Furthermore,we found that RNA binding motif protein 47(RBM47)was the downstream target of miR-518c-5p,that upregulation of RBM47 inhibited EOC cell proliferation,and that RBM47 overexpressing plasmid counteracted the proliferation-promoting effect caused by the IDH1-AS1 knockdown.Taken together,IDH1-AS1 may suppress EOC cell proliferation and tumor growth via the miR-518c-5p/RBM47 axis.

Allocation patterns of nonstructural carbohydrates in response to CO_(2)elevation and nitrogen deposition in Cunninghamia lanceolata saplings

Stored nonstructural carbohydrates(NSC)indicate a balance between photosynthetic carbon(C)assimilation and growth investment or loss through respiration and root exudation.They play an important role in plant function and whole-plant level C cycling.CO_(2)elevation and nitrogen(N)deposition,which are two major environmental issues worldwide,aff ect plant photosynthetic C assimilation and C release in forest ecosystems.However,information regarding the eff ect of CO_(2)elevation and N deposition on NSC storage in diff erent organs remains limited,especially regarding the trade-off between growth and NSC reserves.Therefore,here we analyzed the variations in the NSC storage in diff erent organs of Chinese fi r(Cunninghamia lanceolata)under CO_(2)elevation and N addition and found that NSC concentrations and contents in all organs of Chinese fi r saplings increased remarkably under CO_(2)elevation.However,N addition induced diff erential accumulation of NSC among various organs.Specifi cally,N addition decreased the NSC concentrations of needles,branches,stems,and fi ne roots,but increased the NSC contents of branches and coarse roots.The increase in the NSC contents of roots was more pronounced than that in the NSC content of aboveground organs under CO_(2)elevation.The role of N addition in the increase in the structural biomass of aboveground organs was greater than that in the increase in the structural biomass of roots.This result indicated that a diff erent tradeoff between growth and NSC storage occurred to alleviate resource limitations under CO_(2)elevation and N addition and highlights the importance of separating biomass into structural biomass and NSC reserves when investigating the eff ects of environmental change on biomass allocation.

Selective laser melted AZ91D magnesium alloy with superior balance of strength and ductility

In the context of global carbon neutrality, the application of lightweight magnesium alloys is becoming increasingly attractive. In this study, selective laser melting(SLM) was employed to achieve nearly full dense and crack-free AZ91D components with fine equiaxed grain structure. The formation mechanism of typical pore defects(gas pore, lack-of-fusion pore and keyhole pore) and melting modes(keyhole mode and conduction mode) were systematically studied by varying the laser power and scanning speed. The morphology and volume fraction of the pores under different processing conditions were characterized. A criterion based on the depth-to-width ratio of the melt pool was established to identify different melting modes. The strength and ductility(tensile strength up to 340 MPa and uniform elongation of 8.9%)of the as deposited AZ91D are far superior to those of the casting components and are comparable to those of its wrought counterparts.The superior balance of strength and ductility of SLMed AZ91D, as well as the negligible anisotropic properties are mainly ascribed to the extremely fine equiaxed grain structure(with average grain size of ~1.2 μm), as well as the discontinuous distribution of β-Al_(12)Mg_(17) phases. It thus provides an alternative way to fabricate high-strength magnesium alloys with complex geometry.

Impact of Water Quality Sampling Process on Environmental Monitoring Results

The sampling of environmental water should ensure the representativeness and integrity of the sampled water body,which has an important impact on the monitoring results.The sampling of different water bodies sampling will result in different monitoring results.Based on the study on the problems and influencing factors in the sampling process of environmental water quality,improvement measures during the sampling process were elaborated in the paper,with the aim to strengthen on-site control of water sampling,and reduce adverse effects on monitoring results.

Induction of the LRP16 gene by estrogen promotes the invasive growth of Ishikawa human endometrial cancer cells through the downregulation of E-cadherin

LRP16 以前在乳癌房间作为导致雌激素的基因被识别。到在子宫内膜的癌症(EC ) 的雌激素和它的功能的效果的 LRP16 的应答的海角房间仍然是不清楚的。这里，我们证明 LRP16 基因的信使 rna 水平和倡导者活动被 17beta-estradiol (E2 ) 显著地在雌激素受体高山增加哈(嗯高山哈)-positiveIshikawa 人 EC 房间。尽管 Ishikawa 细胞的生长率没被 LRP16 的宫外的表示显然影响， Transwell 试金的结果显示出 LRP16-overexpressing 细胞的侵略能力的近似 one-thirdincrease。由于分子的屏蔽，我们观察到 E-cadherin 的表示，与肿瘤转移联系的一个必要粘附分子，被 LRP16 镇压。进一步的倡导者分析以一种剂量依赖者方式表明了那 LRP16 inhibitedE-cadherin transactivation。然而，抑制被雌激素剥夺废除，显示由 LRP16requires 的 E-cadherin 抄写的 down 规定嗯高山哈调停。染色质免疫降水分析表明到 E-cadherin 倡导者的 ERalpha 的绑定被 LRP16 反对，建议那 LRP16 能防碍嗯调停 alpha 的抄写。这些结果建议起来由雌激素的 LRP16 的规定能被在人的 EC 调整 E-cadherin 的 down 涉及侵略生长。

Haplotype-resolved genome of diploid ginger (Zingiber officinale) and its unique gingerol biosynthetic pathway

Ginger(Zingiber officinale),the type species of Zingiberaceae,is one of the most widespread medicinal plants and spices.Here,we report a high-quality,chromosome-scale reference genome of ginger‘Zhugen’,a traditionally cultivated ginger in Southwest China used as a fresh vegetable,assembled from PacBio long reads,Illumina short reads,and high-throughput chromosome conformation capture(Hi-C)reads.The ginger genome was phased into two haplotypes,haplotype 1(1.53 Gb with a contig N50 of 4.68 M)and haplotype 0(1.51 Gb with a contig N50 of 5.28 M).Homologous ginger chromosomes maintained excellent gene pair collinearity.In 17,226 pairs of allelic genes,11.9%exhibited differential expression between alleles.Based on the results of ginger genome sequencing,transcriptome analysis,and metabolomic analysis,we proposed a backbone biosynthetic pathway of gingerol analogs,which consists of 12 enzymatic gene families,PAL,C4H,4CL,CST,C3’H,C3OMT,CCOMT,CSE,PKS,AOR,DHN,and DHT.These analyses also identified the likely transcription factor networks that regulate the synthesis of gingerol analogs.Overall,this study serves as an excellent resource for further research on ginger biology and breeding,lays a foundation for a better understanding of ginger evolution,and presents an intact biosynthetic pathway for species-specific gingerol biosynthesis.

Selective adsorption of SF_(6) in covalent-and metal-organic frameworks

Sulfur hexafluoride(SF_(6))is an extremely severe greenhouse gas.It is an urgently important mission to find excellent candidates for selective adsorption of SF_(6),in order to reduce the emission of SF_(6) facilities.Here,we adopt the molecular simulation method to systematically explore the selective adsorption of SF_(6) in 22 kinds of representative covalent-and metal-organic frameworks.Results indicate that COF-6 is a promising candidate for the SF_(6) adsorption at low pressure P<20 kPa because of its small pore size,while MOF-180 and PAF-302 are excellent candidates at high pressure P=2×10^(3) kPa due to their large Brunauer-Emmett-Teller specific surface area(BET SSA)and pore volumes.For the two cases of the power industry(X_(SF_(6))=0.1)and the semiconductor industry(X_(SF_(6))=0.002)environments,COF-6 and ZIF-8 are fairly promising candidates for selective adsorption of SF_(6) from the SF_(6)/N_(2) mixtures,because they not only present the high selectivity,but also the large adsorption capacity at ambient environment,which can be considered as potential adsorbents for selective adsorption of SF_(6) at ambient conditions.

Carbon storage dynamics of subtropical forests estimated with multi-period forest inventories at a regional scale:the case of Jiangxi forests

Temperate and high-latitude forests are carbon sinks and play pivotal roles in offsetting greenhouse gas emissions of CO2.However,uncertainty still exists for subtropical forests,especially in monsoon-prevalent eastern Asia.Earlier studies have depended on remote sensing,ecosystem modeling,carbon fluxes,or single period forest surveys to estimate carbon sequestration capacities,and the results vary significantly.This study was designed to utilize multi-period forest survey data to explore spatial-dynamics of biomass storage in subtropical forests of China.Jiangxi province,a region with over 60%subtropical forest cover,was selected as the case study site and is located in central east China.Based on forest inventory data 1984-2013,and the stock-difference and biomass expansion factor methods,the carbon storage and density,of arboreal forests,economic forests,bamboo forests,woodlands and shrubberies were estimated.The results show that carbon storage increased from 159.1 Tg C in 1988 to 276.1 TgC in 2013,making up 3.1-3.8%of carbon stored throughout China.Among the four types of forests,the amount of carbon stored was as follows:arboreal forest>economic forest>bamboo forest>woodland and shrubbery.Arboreal forests accounted for 64.0-79.4%of the total.Forest carbon density increased from 21.2 Mg C ha-1 in 1984 to26.2 Mg C ha-1 in 2013,equal to 61.2-70.2%of the average carbon density of China’s forests in the same period.Forest carbon storage in Jiangxi will reach 355.5 Tg C and 535.8 Tg C in 2020 and 2030,respectively,and forest carbon density is predicted to be 31.9 Mg C ha-1and 46.4 Mg C ha-1,respectively.As one of the few studies using multi-period data tracking biomass dynamics in Jiangxi province,the findings of this study may be used as a reference for other research.Using Jiangxi as a case study underlies the fact that subtropical forests in China have great carbon sequestration potential and have fundamental significance to offset global environmental change effects.

含颗粒铝合金再结晶的择优取向晶粒数量密度的关联性（英文）

采用EBSD技术研究Al-(Mn)-Fe-Si合金等温退火后的再结晶晶粒结构。统计研究表明,在无沉淀反应条件下,在大于临界直径(约1.1μm)的颗粒相周围形成P取向({011}?566?)晶粒的频率约为2%。晶粒总数量密度与P、立方取向({001}?100?)晶粒的数量成线性关系。再结晶晶粒的总数量密度及典型取向(P、ND旋转立方{001}?310?、立方)晶粒的数量密度随轧制应变量增加而增加,并服从指数规律。

Correction:Haplotype-resolved genome of diploid ginger (Zingiber officinale)and its unique gingerol biosynthetic pathway

After online publication of the article 1,the authors noticed the affiliation“College of Landscape Architecture and Life Science/Institute of Special Plants,Chongqing University of Arts and Sciences,Yongchuan,Chongqing,China”for author Yiqing Liu was missing.

Sustainable wildlife protection on the Qingzang Plateau

Besides its ecological services to China and even Asia,the Qingzang Plateau(QP)hosts a rich variety of wildlife species.During the last century,wildlife population decreased quickly on the QP,driven by human interventions.Recently,wildlife has witnessed rapid recovery mainly propelled by a series of wildlife conservation policies.However,some cautions merit attentions to sustain wildlife restoration and conservation on the QP.This paper casted an overview of environmental and social-economic changes on the QP affecting wildlife subsistence.Re-sults show that QP has been warming,which can benefit wildlife recovery by easing extreme low temperature stresses.The fast growing social economy across the QP lays a solid economic foundation for investing on wildlife protection.Measures such as establishing conservation areas,constructing wildlife pathway corridors,and en-couraging herdsman moving out from wildlife rich regions,have boosted wildlife recovery.However,wildlife recovery is constrained by the limited carrying capacity of the ecosystem,left by domestic livestock.Additionally,fences intended to delineate conservation areas or to separate each type of grassland use,have brought about profound side effects on wildlife through fragmentation of their habitats.It is recommended to set up the fence in a more ecological way,which can be achieved by bypassing the wildlife frequent pathway and using mate-rials devoid of steel barb.Only considering both opportunities and problems simultaneously,can the wildlife protection on the QP be sustained.

Strategy Research on Parent-Child Communication between Family Educations in Network Era

Internet technology is the greatest scientific and technological achievement of mankind in the 20th century.It has brought mankind into the information age and greatly changed people's way of learning,education,work,leisure and entertainment,family education and so on.In the Internet age,underage children spend a considerable amount of time online,and they spend less time talking and communicating with their parents?Therefore,the development of network technology has posed a new challenge not only to school education and social education,but also to the traditional family education[6].So,under the impact and challenge of the network era,what countermeasures do family education apply to communicate well with children?This is the center of this research.

Challenges Brought by College Students’Selforganization of Network and Measures in the Era of We-Media

In the era of We-Media,the rapid development of college students’self-organization of network has a great impact on the college students and also brought new challenges to the educational management in colleges.Colleges should actively respond to challenges and explore practical measures to promote the healthy and benign development of college students’self-organization of network:First,innovate teaching concepts,upgrade new media technologies,and build a modern teaching team;Second,actively occupy the online platforms,impart high-quality resources,and develop flexible,guiding education with clear classification;Third,develop reasonable rules and regulations,related management departments and teams,and carry out efficient and comprehensive management.

Microstructure Recrystallization and Mechanical Properties of a Cold-Rolled TiNbZrTaHf Refractory High-Entropy Alloy

The equiatomic TiNbZrTaHf alloy was successfully rolled at room temperature with the reduction of ~ 85%. The microstructure and tensile properties were investigated after cold working and annealing. It was determined that the recrystallization temperature of the TiNbZrTaHf alloy between 850 and 900 ℃. Complete recrystallization and normal grain growth occurred, the high stability of single phase was maintained after annealing at 1000, 1200, and 1400 ℃. But the precipitated phase appeared after long term annealing, as seen after 500 h at 1000 ℃. After cold working, the tensile strength and the elongation of TiNbZrTaHf were 1137 MPa and 25.1%, respectively. The annealed alloy has a high tensile strength (σ_(b )= 863 MPa) and ductility (ε_(e )= 28.5%). Moreover, the oxidation of TiNbZrTaHf alloy at elevated temperatures has a significant impact on its mechanical properties. The poor oxidation resistance of TiNbZrTaHf can accelerate tensile failure by inducing fractures at grain boundaries.

Development and validation of a novel non-invasive test for diagnosing nonalcoholic fatty liver disease in Chinese children

With the exploding prevalence of obesity,many children are at risk of developing nonalcoholic fatty liver disease.Using anthropometric and laboratory parameters,our study aimed to develop a model to quantitatively evaluate liver fat content(LFC)in children with obesity.Methods A well-characterized cohort of 181 children between 5 and 16 years of age were recruited to the study in the Endocrinology Department as the derivation cohort.The external validation cohort comprised 77 children.The assessment of liver fat content was performed using proton magnetic resonance spectroscopy.Anthropometry and laboratory metrics were measured in all subjects.B-ultrasound examination was carried out in the external validation cohort.The Kruskal-Wallis test,Spearman bivariate correlation analyses,univariable linear regressions and multivariable linear regression were used to build the optimal predictive model.Results The model was based on indicators including alanine aminotransferase,homeostasis model assessment of insulin resistance,triglycerides,waist circumference and Tanner stage.The adjusted R^(2)of the model was 0.589,which presented high sensitivity and specificity both in internal[sensitivity of 0.824,specificity of 0.900,area under curve(AUC)of 0.900 with a 95%confidence interval:0.783–1.000]and external validation(sensitivity of 0.918 and specificity of 0.821,AUC of 0.901 with a 95%confidence interval:0.818–0.984).Conclusions Our model based on five clinical indicators was simple,non-invasive,and inexpensive;it had high sensitivity and specificity in predicting LFC in children.Thus,it may be useful for identifying children with obesity who are at risk for developing nonalcoholic fatty liver disease.

The Combined Effects of High Temperatures and Ozone Pollution on Medical Emergency Calls—Jinan City,Shandong Province,China,2013–2019

What is already known about this topic?Studies have extensively documented the separate and independent effects of extreme temperature and ozone on morbidity and mortality associated with respiratory and circulatory diseases.What is added by this report?The study revealed a significant association between elevated temperature,ozone pollution,and the combined effect of high temperature and ozone pollution with an increased risk of all-cause medical emergency calls(MECs)and MECs specifically related to neurological diseases.What are the implications for public health practice?Interventional measures should be implemented to mitigate exposure to high temperatures and ozone levels.Specifically,during the warm season,it is crucial for relevant authorities to focus on disseminating scientific information regarding the health impacts of elevated temperatures and ozone pollution.Additionally,timely public health advisories should be issued to alert the public effectively.

Generation of tooth-like structures from integration-free human urine induced pluripotent stem cells

Background:Tooth is vital not only for a good smile,but also good health.Yet,we lose tooth regularly due to accidents or diseases.An ideal solution to this problem is to regenerate tooth with patients’own cells.Here we describe the generation of tooth-like structures from integration-free human urine induced pluripotent stem cells(ifhU-iPSCs).Results:We first differentiated ifhU-iPSCs to epithelial sheets,which were then recombined with E14.5 mouse dental mesenchymes.Tooth-like structures were recovered from these recombinants in 3 weeks with success rate up to 30%for 8 different iPSC lines,comparable to H1 hESC.We further detected that ifhU-iPSC derived epithelial sheets differentiated into enamel-secreting ameloblasts in the tooth-like structures,possessing physical properties such as elastic modulus and hardness found in the regular human tooth.Conclusion:Our results demonstrate that ifhU-iPSCs can be used to regenerate patient specific dental tissues or even tooth for further drug screening or regenerative therapies.

Rhinitis may be a clinical symptom of primary pulmonary lymphoepithelioma-like carcinoma,an incidental finding during the COVID-19 pandemic

To the Editor:Primary pulmonary lymphoepithelioma-like carcinoma(PPLELC)is considered to be a rare type of lung cancer and is caused by long-term Epstein-Barr virus infection with clinical symptoms similar to most lung cancers.During the COVID-19 pandemic,we treated a seemingly asymptomatic patient with PPLELC comorbidity who was admitted to the hospital for an acute attack of chronic rhinitis.The chest computed tomography(CT)scans showed an abnormal mass in the patient's lung.Based on this clinical case,we propose that there is a positive correlation between chronic Epstein-Barr virus-related rhinitis and PPLELC.In addition,we recommend that patients with rhinitis who are infected by the Epstein-Barr virus receive continuous antiviral therapy with regular monitoring of the viral concentration and CT scans.