综合化学实验设计:氧桥三核铁(Ⅲ)配合物的便捷制备与表征

目前本科化学实验教学内容在配合物制备实验方面主要涵盖了单核配合物,而对配合物家族中占有重要地位的多核配合物却很少涉及。基于此,我们依据科研成果设计了一个关于三核铁(Ⅲ)配合物的综合化学实验,以期通过该实验加深学生对配合物有关知识的理解和运用。本设计以廉价易得的九水合硝酸铁与三水合乙酸钠为原料,通过水浴加热反应、冷却结晶等步骤制备了一种氧桥三核铁(Ⅲ)配合物[Fe_(3)O(CH_(3)COO)_(6)(H_(2)O)_(3)]NO_(3)·4H_(2)O,通过配位滴定法测定了其铁元素含量,并对其进行了红外、热重、粉末X射线衍射和电子顺磁共振等表征测试。该实验制备方法简单快捷,易于操作,环保无污染。实验内容蕴含思政元素,目标配合物结构新颖,富有对称美,实验教学时亦可培养学生的审美意识,使其领略化学之美。本设计科教融合,有助于培养学生分析解决问题的能力,为本科生的综合化学实验教学提供了一个可行案例。

Extracellular and intracellular infection of Botryosphaeria dothidea and resistance mechanism in apple cells

Apple ring rot,which is caused by Botryosphaeria dothidea,severely affects apple production.The mechanisms employed in apple cells against B.dothidea remain unknown.In this research,the pathogen infection mode and the relationship between cell death and disease resistance in‘Fuji’/B.dothidea interaction pathosystem were investigated.By using transmission electron microscopy(TEM),our research showed that the pathogen infects apple cells both intracellularly and extracellularly.However,compared with that in immature fruit,the incidence of hyphae in the interior of mature apple fruit cells increased dramatically,suggesting that cell wall-mediated penetration resistance could be important in apple resistance against B.dothidea.TEM ultrastructural characterization identified the nuclear morphology of programmed cell death induction in both apple fruit and callus cells under B.dothidea infection.Overexpression of MdVDAC2(MDP0000271281),which encodes an outer-membrane localized anion channel protein in mitochondria,significantly promoted cell death under B.dothidea infection and simultaneously inhibited pathogen infection,suggesting that cell death represents a disease resistance mechanism in apple against B.dothidea infection.Furthermore,BdCatalase(KAF4307763),a cytochromeP450 family protein BdCYP52A4(KAF4300696),and subtilisin-domain containing proteinswere identified fromB.dothidea-secreted proteins,which suggested the potential involvement of active oxygen species and phytoalexins in combating B.dothidea infection and triggering or dampening apple resistance.Collectively,our research suggested that cell wall-mediated penetration resistance,programmed cell death machinery and microbial effector-interrelated signaling were among strategies recruited in apple to combat B.dothidea.The current research laid the foundation for further investigations into resistance mechanisms in apple.

The ABA-induced NAC transcription factor MdNAC1 interacts with a bZIP-type transcription factor to promote anthocyanin synthesis in red-fleshed apples

Anthocyanins are valuable compounds in red-fleshed apples.The MdMYB10 transcription factor is an important regulator of the anthocyanin synthesis pathway.However,other transcription factors are key components of the complex network controlling anthocyanin synthesis and should be more thoroughly characterized.In this study,we used a yeast-based screening technology to identify MdNAC1 as a transcription factor that positively regulates anthocyanin synthesis.The overexpression of MdNAC1 in apple fruits and calli significantly promoted the accumulation of anthocyanins.In binding experiments,we demonstrated that MdNAC1 combines with the bZIP-type transcription factor MdbZIP23 to activate the transcription of MdMYB10 and MdUFGT.Our analyses also indicated that the expression of MdNAC1 is strongly induced by ABA because of the presence of an ABRE cis-acting element in its promoter.Additionally,the accumulation of anthocyanins in apple calli co-transformed with MdNAC1 and MdbZIP23 increased in the presence of ABA.Therefore,we revealed a novel anthocyanin synthesis mechanism involving the ABA-induced transcription factor MdNAC1 in red-fleshed apples.

Interface bond degradation and damage characteristics of full-length grouted rock bolt in tunnels with high temperature

Full-length grouted bolts play a crucial role in geotechnical engineering thanks to their excellent stability.However,few studies have been concerned with the degrading performance of grouted rock bolts caused by extensive and continuous heat conduction from surrounding rocks in high-geothermal tunnels buried more than 100 m(temperature from 28C to 100C).To investigate the damage mechanism,we examined the time-varying behaviors of grouted rock bolts in both constant and variable temperature curing environments and their damage due to the coupling effects of high temperature and humidity through mechanical and micro-feature tests,including uniaxial compression test,pull-out test,computed tomography(CT)scans,X-ray diffraction(XRD)test,thermogravimetric analysis(TGA),etc.,and further analyzed the relationship between grout properties and anchorage capability.In order to facilitate a rapid assessment and control of the anchorage performance of anchors in different conditions,results of the interface bond degradation tests were correlated to environment parameters based on the damage model of interfacial bond stress proposed.Accordingly,a thermal hazard classification criterion for anchorage design in high-geothermal tunnels was suggested.Based on the reported results,although high temperature accelerated the early-stage hydration reaction of grouting materials,it affected the distribution and quantity of hydration products by inhibiting hydration degree,thus causing mechanical damage to the anchorage system.There was a significant positive correlation between the strength of the grouting material and the anchoring force.Influenced by the changes in grout properties,three failure patterns of rock bolts typically existed.Applying a hot-wet curing regime results in less reduction in anchorage force compared to the hot-dry curing conditions.The findings of this study would contribute to the design and investigations of grouted rock bolts in high-geothermal tunnels.

MdGSTF6,activated by MdMYB1,plays an essential role in anthocyanin accumulation in apple

Anthocyanins are biosynthesized on the cytosolic surface of the endoplasmic reticulum and then transported into the vacuole for storage.Glutathione S-transferases(GSTs)are considered to be responsible for the transport of anthocyanins into the vacuole.However,the regulatory mechanisms of GSTs in plants are still unclear.Here,we performed a genome-wide analysis and identified 69 GST genes in apple.The expression of MdGSTF6 was positively correlated with the anthocyanin content(r=0.949)during‘Yanfu 8’fruit development.The overexpression of MdGSTF6 in the Arabidopsis thaliana tt19 mutant resulted in seedlings of 35S::MdGSTF6-GFP/tt19 that could accumulate anthocyanin and rescue its phenotype,suggesting that MdGSTF6 was an anthocyanin transporter.The silencing of MdGSTF6 affected anthocyanin accumulation in apple fruit.Moreover,the knockdown of MdGSTF6 by RNA interference in cultured‘Gala’seedlings inhibited anthocyanin accumulation.The interaction experiments showed that MdMYB1 could bind directly to the MdGSTF6 promoter to transcriptionally activate its expression.Collectively,our results demonstrate that MdGSTF6 encodes an important GST transporter of anthocyanins in apple fruit and provide evidence for the associated regulatory mechanisms.Therefore,MdMYB1 can not only regulate anthocyanin synthesis,but also control the transport of anthocyanin in apples.This information may be useful for further clarifying the regulation of anthocyanin transport in apple.

Malus sieversii: the origin, flavonoid synthesis mechanism, and breeding of red-skinned and red-fleshed apples

Flavonoids play essential roles in human health.Apple(Malus domestica Borkh.),one of the most widely produced and economically important fruit crops in temperate regions,is a significant source of flavonoids in the human diet and is among the top nutritionally rated and most widely consumed fruits worldwide.Epidemiological studies have shown that the consumption of apples,which are rich in a variety of free and easily absorbable flavonoids,is associated with a decreased risk of various diseases.However,apple production is challenged by serious inbreeding problems.The narrowing of the hereditary base has resulted in apples with poor nutritional quality and low flavonoid contents.Recently,there have been advances in our understanding of the roles that Malus sieversii(Ledeb.)M.Roem has played in the process of apple domestication and breeding.In this study,we review the origin of cultivated apples and red-fleshed apples,and discuss the genetic diversity and construction of the core collections of M.sieversii.We also discuss current research progress and breeding programs on red-skinned and red-fleshed apples and summarize the exploitation and utilization of M.sieversii in the breeding of high-flavonoid,and red-fleshed apples.This study highlights a valuable pattern of horticultural crop breeding using wild germplasm resources.The future challenges and directions of research on the molecular mechanisms of flavonoid accumulation and high-flavonoid apple breeding are discussed.

MdMYB6 regulates anthocyanin formation in apple both through direct inhibition of the biosynthesis pathway and through substrate removal

Anthocyanin biosynthesis and sugar metabolism are important processes during plant growth,but the molecular interactions underlying these pathways are still unclear.In this work,we analyzed the anthocyanin and soluble sugar contents,as well as the transcript levels of transcription factors that are known to be related to the biosynthesis of anthocyanin in‘Hongcui 1’apple flesh during fruit development.Overexpression of MdMYB6 in red-fleshed calli was found to reduce anthocyanin content and result in downregulated expression of the MdANS and MdGSTF12 proteins.Yeast one-hybrid and electrophoretic mobility shift analyses showed that MdMYB6 could directly bind to the promoters of MdANS and MdGSTF12,indicating that MdMYB6 could inhibit anthocyanin biosynthesis by regulating MdANS and MdGSTF12.Overexpression of MdTMT1 in the Arabidopsis tmt1 mutant restored the glucose and fructose contents to the wild-type levels,while overexpression of MdTMT1 in red-fleshed calli increased the contents of glucose and fructose but reduced the contents of UDP-glucose,UDP-galactose,and anthocyanin.Using a GUS reporter system,yeast one-hybrid,chromatin immunoprecipitation-PCR and electrophoretic mobility shift analyses,we found that MdMYB6 could bind to the promoter of MdTMT1,resulting in increased promoter activity.Overexpression of MdMYB6 in calli overexpressing MdTMT1 increased the expression of MdTMT1,which led to reduced contents of UDP-glucose and UDP-galactose and decreased anthocyanin content compared to those of the calli that overexpressed MdTMT1.This finding suggested that MdMYB6 could also inhibit anthocyanin biosynthesis by regulating MdTMT1 to decrease the contents of UDP-glucose and UDP-galactose.Taken together,these results showed that MdMYB6 and MdTMT1 play key roles in both anthocyanin biosynthesis and sugar transport.

On the Ecological Restoration Mode of Urban Water Revetment Landscape

Urban waterfront revetment is a special zone between water and land,with high ecological,economic and aesthetic value. Waterfront revetment landscape is not only an important part of urban water and land ecosystems,but also an integral part of the city. Based on the current situation of ecological environment of waterfront revetment landscape,we come up with different ecological restoration modes for different types of revetment,to achieve the organic integration of waterfront revetment landscape and ecology.

Comparison of temperature extremes between Zhongshan Station and Great Wall Station in Antarctica

Although temperature extremes have led to more and more disasters, there are as yet few studies on the extremes and many disagreements on temperature changes in Antarctica. Based on daily minimum, maximum, and mean air temperatures(Tmin, Tmax, Tmean) at Great Wall Station(GW) and Zhongshan Station(ZS), we compared the temperature extremes and revealed a strong warming trend in Tmin, a slight warming trend in Tmean, cooling in Tmax, a decreasing trend in the daily temperature range, and the typical characteristic of coreless winter temperature. There are different seasonal variabilities, with the least in summer. The continentality index and seasonality show that the marine air mass has more effect on GW than ZS. Following the terminology of the Fifth Assessment Report of the Intergovernmental Panel on Climate Change(IPCC AR5), we defined nine indices of temperature extremes, based on the Antarctic geographical environment. Extreme-warm days have decreased, while extreme-warm nights have shown a nonsignificant trend. The number of melting days has increased at GW, while little change at ZS. More importantly, we have found inverse variations in temperature patterns between the two stations, which need further investigation into the dynamics of climate change in Antarctica.

Advances in Research on Anti-tumor Active Components of Labiatae Plants

In recent years, the antibacterial and anti-inflammatory effects of the Labiatae plants have been widely recognized, and have been used in clinical practice, and their anti-tumor effects are also very significant, and receiving more and more attention. At present, malignant tumors are still the first killer threatening human health. Because of the long-term use of chemical anti-tumor drugs with certain drug resistance and obvious side effects, finding high-efficiency anti-tumor active ingredients from natural plants and Chinese herbal medicines has become a hot spot in the field of pharmacy. Literature survey indicates that the active ingredients in Labiatae plants have anti-tumor effects. Therefore, this paper summarized and discussed the anti-tumor types, mechanisms and active components of the Labiatae plants, so as to provide a basis and reference for the development of new anti-tumor drugs or preparations.

Research Progress of Main Pests in Sweetsop ( Annona squamosa L. ) and Its Insecticide Activity

The research progress on pests and insecticide activity of Annona squamosa L. is summarized in the paper, including symptom, occurrence regularity and control methods. Furthermore, the comprehensive technique for controlling pests of A. squamosa in the future is preliminarily discussed.

Prescription Design and Preparation Process of Paeonol Bead Popping Gum with Hypoglycemic Effect

[Objectives]To develop a paeonol bead popping gum with hypoglycemic effect.[Methods]The paeonol bead popping gum was prepared by the"two-step method",that is,the pill core was prepared by the guttate pill method,and then the coating was cured by sodium alginate solution and CaCl_(2) solution.The single factor method was used to determine the effects of PEG-4000:paeonol dosage ratio,dropper diameter,condensation time,dropping distance,melting temperature on the comprehensive score of paeonol guttate pill,and the effects of sodium alginate solution concentration,CaCl_(2) solution concentration,number of coating layers,drying time on the comprehensive score of popping gum.Finally,the optimal process was determined and verified by orthogonal experiment method.[Results]When the dosage ratio of PEG-4000:paeonol was 4∶1,the dropper diameter was 4 mm,the condensation time was 5 min,the dropping distance was 6 cm,and the melting temperature was 90℃,the quality of the prepared guttate pill was the optimal.When the concentration of sodium alginate solution was 0.02 g/mL,the concentration of CaCl_(2) solution was 0.25 g/mL,the number of coating layers was 3,and the drying time was 25 min,the appearance and comprehensive score of the obtained popping beads were the optimal.[Conclusions]This study is expected to provide some reference and basis for the development and utilization of hypoglycemic products of traditional Chinese medicine.

A critical review on lead migration, transformation and emission control in Chinese coal-fired power plants

Coal is widely utilized as an important energy source,but coal-fired power plant was considered to be an important anthropogenic lead emission source.In the present study,the distribution characteristics of lead in coal and combustion by-products are reviewed.Specifically,lead is mainly transferred to ash particles and the formation and migration mechanisms of particulate lead are summarized.Also,targeted measures are proposed to control the formation of fine particulate lead as well as to increase the removal efficiency during the low-temperature flue gas clean process.In detail,interactions between gaseous lead and some coal-bearing minerals or added adsorbents could obviously suppress the formation of fine particulate lead.On the other hand,some efforts(including promoting capture of fine particles,reducing resistivity of particles and strengthening the gas-liquid contact)could be made to improve the fine particulate lead removal capacity.Notably,the formation mechanism of fine particulate lead is still unclear due to the limitations of research methods.Some differences in the removal principles of fine particles and particulate lead make the lead emission precisely control a great challenge.Finally,the environmental potential risk of lead emission from flue gas and ash residues is addressed and further discussed.

鄂尔多斯盆地东缘二叠系山_(2)^(3)亚段海陆过渡相页岩岩相类型与储层发育特征

中国海陆过渡相页岩气的开发正处于起步阶段,而开展页岩岩相划分及储层特征的研究则有利于页岩气的进一步勘探开发。通过薄片鉴定、X-射线全岩衍射、扫描电镜等一系列方法对鄂尔多斯盆地东缘山_(2)^(3)亚段海陆过渡相页岩进行精细研究。结合矿物成分、TOC含量将山_(2)^(3)亚段页岩划分为8种不同的岩相,其中主要发育4种岩相:富有机质黏土质硅质页岩(Ⅰ_(2));富有机质含钙黏土质硅质页岩(Ⅰ_(3));富有机质含钙硅质黏土页岩(Ⅱ_(3));富有机质含钙含硅黏土页岩(Ⅱ_(4))。不同岩相储层品质具有较大差异,富有机质含钙硅质黏土页岩(Ⅱ_(3))TOC含量最高,孔隙之间连通性好,孔比表面积最大,相对应赋存的吸附气含量也较高,发育有良好的纹层状构造,易于压裂形成渗流通道,为最优页岩相;富有机质黏土质硅质页岩(Ⅰ_(2))发育层状构造,易于压裂,孔体积最大,相对应的游离气的聚集含量就越高,为次优页岩相;富有机质含钙黏土质硅质页岩(Ⅰ_(3))及富有机质含钙含硅黏土页岩(Ⅱ_(4))纹层发育情况一般,储层发育程度均低于另外2种岩相,为中等页岩相,不利于勘探开发。

Autophagy receptor CCDC50 tunes the STING-mediated interferon response in viral infections and autoimmune diseases

DNA sensing and timely activation of interferon(IFN)-mediated innate immunity are crucial for the defense against DNA virus infections and the clearance of abnormal cells.However,overactivation of immune responses may lead to tissue damage and autoimmune diseases;therefore,these processes must be intricately regulated.STING is the key adaptor protein,which is activated by cyclic GMP-AMP,the second messenger derived from cGAS-mediated DNA sensing.Here,we report that CCDC50,a newly identified autophagy receptor,tunes STING-directed type I IFN signaling activity by delivering K63-polyubiquitinated STING to autolysosomes for degradation.Knockout of CCDC50 significantly increases herpes simplex virus 1(HSV-1)-or DNA ligand-induced production of type I IFN and proinflammatory cytokines.Ccdc50-deficient mice show increased production of IFN,decreased viral replication,reduced cell infiltration,and improved survival rates compared with their wild-type littermates when challenged with HSV-1.Remarkably,the expression of CCDC50 is downregulated in systemic lupus erythematosus(SLE),a chronic autoimmune disease.CCDC50 levels are negatively correlated with IFN signaling pathway activation and disease severity in human SLE patients.CCDC50 deficiency potentiates the cGAS-STING-mediated immune response triggered by SLE serum.Thus,our findings reveal the critical role of CCDC50 in the immune regulation of viral infections and autoimmune diseases and provide insights into the therapeutic implications of CCDC50 manipulation.

不同配方益生菌在高脂饮食诱导小鼠肥胖发生中的差异化作用

【目的】基于肠道微生物与宿主代谢的相互关系,研究不同配方的益生菌对小鼠肥胖的影响。【方法】50只C57BL/6J雄性小鼠随机平均分成10组,分别给予正常饲料、高脂饲料以及高脂饲料加8种不同配方的益生菌产品(50亿CFU/只),所有动物连续喂养9周,每周测量小鼠体重1次。最后一周测定空腹血糖、葡萄糖耐量试验(glucose tolerance test,GTT)、血脂相关指标,称取内脏重量,并留取小鼠盲肠内容物,提取小鼠肠道菌群总DNA,利用16S rDNA测序检测相关细菌含量。【结果】部分益生菌可引起小鼠体重增速加快,而部分益生菌可减缓小鼠肥胖和降低内脏脂肪重量,同时缓解高血脂症。丹尼斯克品牌益生菌配方组小鼠肠道中厚壁菌/拟杆菌比例(F/B)是正常饮食组的22.8倍,Akkermansia muciniphila(Akkermansia)细菌含量几乎为0;而菌拉丁品牌益生菌配方组小鼠F/B比例与正常饲料饮食组类似,Akkermansia含量为0.5%,为正常饮食对照组小鼠的一半左右。【结论】益生菌可影响小鼠体重和代谢,但不同配方的益生菌效果截然相反。特定的益生菌配方对肥胖和高血脂的改善可能是由于其选用的菌株本身的特性以及菌株之间的相互配比能够降低小鼠肠道中F/B比例以及升高Akkermansia的含量所带来的。此研究为进一步开发可改善代谢的益生菌产品提供了参考。

Generation of 84-fs pulses from a mode-locked Tm：CNNGG disordered garnet crystal laser

A mode-locked laser based on a Tm:CNNGG disordered crystal as an active medium and a single-walled carbon nanotube saturable absorber is demonstrated, operating at a central wavelength of 2018 nm. Transformlimited 84 fs pulses are generated with an average output power of 22 mW at a repetition rate of ~90 MHz.A maximum output power of 98 mW is obtained at a slightly longer pulse duration of 114 fs.

Energetics of Boreal Wintertime Blocking Highs around the Ural Mountains

Based on the daily Japanese 55-yr reanalysis data,this study analyzes the maintenance mechanism for 53 boreal winter blocking highs around the Ural Mountains(UBHs)during 1958-2018 based on the atmospheric energy budget equations.After decomposing the circulation into background flow,low-frequency anomalies,and high-frequency eddies,it was found that the interaction between the background flow and low-frequency anomalies is conducive to the maintenance of the UBHs.Due to the southwestward gradient in the climatological mean air temperature over the Eurasian continent,it is easy for the air temperature anomalies as well as the wind velocity anomalies in the middle and lower troposphere induced by the UBHs to facilitate the positive conversion of baroclinic energy associated with the background flow into the UBHs.Likewise,the conversion of barotropic energy associated with the background flow is also evident in the upper troposphere,in which the climatological mean westerlies have evident southward gradient to the northwest of Lake Baikal and southwestward gradient over Barents Sea.Note that the conversion of baroclinic energy associated with the background flow is dominant throughout the lifecycle of UBHs,acting as the major contributor to the maintenance of the UBHs.Although transient eddies facilitate maintenance of the UBHs via positive conversion of barotropic energy in the middle and upper troposphere,they hinder the maintenance of UBHs via negative conversion of baroclinic energy in the lower troposphere.The diabatic heating anomalies tend to counteract the local air temperature anomalies in the middle and lower troposphere,which damps the available potential energy of UBHs and acts as a negative contributor to the UBHs.

Correction: Autophagy receptor CCDC50 modulates STING-mediated interferon response in viral infection and autoimmune disease

Correction to:Cellular&Molecular Immunology https://doi.org/10.1038/s41423-021-00758-w In the version of this article initially published,one unintended error was made during manuscript editing.The title of the article was not in accordance with that of the original manuscript,and the correct statement is“Autophagy receptor CCDC50 modulates STING-mediated interferon response in viral infection and autoimmune disease”.The results and conclusions are not affected.