Unveiling the pressure-driven metal–semiconductor–metal transition in the doped TiS_(2)

Conventional theories expect that materials under pressure exhibit expanded valence and conduction bands,leading to increased electrical conductivity.Here,we report the electrical properties of the doped 1T-TiS_(2) under high pressure by electrical resistance investigations,synchrotron x-ray diffraction,Raman scattering and theoretical calculations.Up to 70 GPa,an unusual metal-semiconductor-metal transition occurs.Our first-principles calculations suggest that the observed anti-Wilson transition from metal to semiconductor at 17 GPa is due to the electron localization induced by the intercalated Ti atoms.This electron localization is attributed to the strengthened coupling between the doped Ti atoms and S atoms,and the Anderson localization arising from the disordered intercalation.At pressures exceeding 30.5 GPa,the doped TiS_(2) undergoes a re-metallization transition initiated by a crystal structure phase transition.We assign the most probable space group as P2_12_12_1.Our findings suggest that materials probably will eventually undergo the Wilson transition when subjected to sufficient pressure.

Therapeutic Effect of Intragastric Administration of Jiangtang Shuxin Recipe Suspension on Diabetic Heart Failure in Rats and Its Mechanism

[Objectives]To observe the therapeutic effect of intragastric administration of Jiangtang Shuxin recipe on diabetic heart failure(DHF)in rats and to explore its mechanism.[Methods]Fifty SD rats were randomly divided into five groups,with 10 rats in each group.DHF models were prepared in the low-dose group,high-dose group,Western medicine group,and model group except the control group.Rats in the low-dose and high-dose groups were given 1.0 and 1.5 g/(kg·d)Jiangtang Shuxin recipe suspension by gavage,respectively.Rats in the Western medicine group were given gliquidone and benazepril by gavage for 2 months,and were fed with high-fat diet.Rats in the control group were fed with ordinary diet.Fasting blood glucose(FBG),serum triglyceride(TG),low-density lipoprotein cholesterol(LDL-C),high-density lipoprotein cholesterol(HDL-C),C-reactive protein(CRP),interleukin-6(IL-6),tumor necrosis factor-α(TNF-α),creatine kinase isoenzyme(CK-MB),lactate dehydrogenase(LDH),pathological morphology of myocardial tissue,NF-κB p65 protein and IκBαprotein were compared among groups.[Results]Compared with the control group,the levels of FBG,serum TG,LDL-C,CRP,IL-6,TNF-α,CK-MB and LDH increased,while the level of serum HDL-C decreased.The myocardial tissue was seriously damaged,and the expression of NF-κB p65 protein increased,while the expression of IκBαprotein decreased in the other four gruops(all P<0.05).Compared with the model group,the levels of FBG,serum TG,LDL-C,CRP,IL-6,TNF-α,CK-MB and LDH decreased,while the serum HDL-C level increased.The myocardial tissue damage was alleviated,and the expression of NF-κB p65 protein decreased,while the expression of IκBαprotein increased in the low-dose group,high-dose group and Western medicine group(all P<0.05).Compared with the Western medicine group,the levels of FBG,serum TG,LDL-C,CRP,IL-6,TNF-α,CK-MB and LDH decreased,and the level of serum HDL-C increased in the high-dose group(all P<0.05).[Conclusions]Jiangtang Shuxin recipe has a therapeutic effect on DHF in rats,with the best effect in the high-dose group.It can not only alleviate high glucose and high fat state,but also reduce myocardial injury and inflammation,and improve the pathological morphology of myocardial cells.The mechanism may be related to its inhibition of NF-кB signaling pathway.

Integrating UHPLC-MS/MS quantitative analysis and exogenous purine supplementation to elucidate the antidepressant mechanism of Chaigui granules by regulating purine metabolism

Chaigui granules(CG)are a compound composed of six herbal medicines with significant antidepressant effects.However,the antidepressant mechanism of CG remains unclear.In the present study,we attempted to elucidate the antidepressant mechanism of CG by regulating purine metabolism and purinergic signaling.First,the regulatory effect of CG on purine metabolites in the prefrontal cortex(PFC)of chronic unpredictable mild stress(CUMS)rats was analyzed by ultra high-performance liquid chromatography tandem mass spectrometry(UHPLC-MS/MS)targeted quantitative analysis.Meanwhile,purinergic receptors(P2X7 receptor(P2X7R),A1 receptor(A1R)and A2A receptor(A2AR))and signaling pathways(nod-like receptor protein 3(NLRP3)inflammasome pathway and cyclic adenosine monophosphate(cAMP)-protein kinase A(PKA)pathway)associated with purine metabolism were analyzed by western blotting and enzyme-linked immunosorbent assay(ELISA).Besides,antidepressant mechanism of CG by modulating purine metabolites to activate purinergic receptors and related signaling pathways was dissected by exogenous supplementation of purine metabolites and antagonism of purinergic receptors in vitro.An in vivo study showed that the decrease in xanthine and the increase in four purine nucleosides were closely related to the antidepressant effects of CG.Additionally,purinergic receptors(P2X7R,A1R and A2AR)and related signaling pathways(NLRP3 inflammasome pathway and cAMP-PKA pathway)were also significantly regulated by CG.The results of exogenous supplementation of purine metabolites and antagonism of purinergic receptors showed that excessive accumulation of xanthine led to activation of the P2X7R-NLRP3 inflammasome pathway,and the reduction of adenosine and inosine inhibited the A1R-cAMP-PKA pathway,which was significantly ameliorated by CG.Overall,CG could promote neuroprotection and ultimately play an antidepressant role by inhibiting the xanthine-P2X7R-NLRP3 inflammasome pathway and activating the adenosine/inosine-A1R-cAMP-PKA pathway.

Seamlessly Merging the Capacity of P into Sb at Same Voltage with Maintained Superior Cycle Stability and Low-temperature Performance for Li-ion Batteries

Among the alloying-type anodes,elemental Sb possesses the suitable yet safe plateau,simple lithiation pathway,small voltage polarization,high conductivity,and superior cycle stability.However,challenge is that its intrinsic capacity is rather low(660 mAh g^(-1)),<1/6 of silicon.Herein,we propose a seamless integration strategy by merging the voltage and capacity of phosphorus and antimony into a solid solution alloy.Interestingly,the enlistment of P is found greatly enlarge the capacity from 660 to 993 mAh g^(-1) for such Sb_(30)P_(30) solid solution,while maintaining a single and stable discharge plateau(~0.79 V)similar to elemental Sb.Various experimental characterizations including XPS,PDF,Raman,and EDS mapping reveal that in such a material the P and Sb atoms have interacted with each other to form a homogenous solid solution alloy,rather than a simple mixing of the two substances.Thus,the Sb_(30)P_(30) exhibits superior rate performances(807 mAh g^(-1) at 5000 mA g^(-1))and cyclability(821 mAh g^(-1) remained after 300 cycles).Furthermore,such Sb_(60-x)P_(x) alloys can even deliver 621 mAh g^(-1) at
30℃,which can be served as the alternative anode materials for high-energy and low-temperature batteries.This unique seamless integration strategy based on solid solution chemistry can be easily leveraged to manipulate the capacity of other electrode materials at similar voltage.

A New Partial Task Offloading Method in a Cooperation Mode under Multi-Constraints for Multi-UE

In Multi-access Edge Computing(MEC),to deal with multiple user equipment(UE)’s task offloading problem of parallel relationships under the multi-constraints,this paper proposes a cooperation partial task offloading method(named CPMM),aiming to reduce UE’s energy and computation consumption,while meeting the task completion delay as much as possible.CPMM first studies the task offloading of single-UE and then considers the task offloading ofmulti-UE based on single-UE task offloading.CPMMuses the critical path algorithmto divide the modules into key and non-key modules.According to some constraints of UE-self when offloading tasks,it gives priority to non-key modules for offloading and uses the evaluation decision method to select some appropriate key modules for offloading.Based on fully considering the competition between multiple UEs for communication resources and MEC service resources,CPMM uses the weighted queuing method to alleviate the competition for communication resources and uses the branch decision algorithm to determine the location of module offloading by BS according to the MEC servers’resources.It achieves its goal by selecting reasonable modules to offload and using the cooperation ofUE,MEC,andCloudCenter to determine the execution location of themodules.Extensive experiments demonstrate that CPMM obtains superior performances in task computation consumption reducing around 6%on average,task completion delay reducing around 5%on average,and better task execution success rate than other similar methods.

The mechanism of astragaloside Ⅳ promoting sciatic nerve regeneration

3-O-beta-D-xylopyranosyl-6-O-beta-D-glucopyranosyl-cycloastragenol （astragaloside IV）, the main active component of the traditional Chinese medicine astragalus membranaceus, has been shown to be neuroprotective. This study investigated whether astragaloside IV could promote the repair of injured sciatic nerve. Denervated sciatic nerve of mice was subjected to anastomosis. The mice were intraperitoneally injected with 10, 5, 2.5 mg/kg astragaloside IV per day for 8 consecutive days Western blot assay and real-time PCR results demonstrated that growth-associated protein-43 ex- pression was upregulated in mouse spinal cord segments L4-6 after intervention with 10, 5, 2.5 mg/kg astragaloside IV per day in a dose-dependent manner. Luxol fast blue staining and elec- trophysiological detection suggested that astragaloside IV elevated the number and diameter of myelinated nerve fibers, and simultaneously increased motor nerve conduction velocity and action potential amplitude in the sciatic nerve of mice. These results indicated that astragaloside IV con- tributed to sciatic nerve regeneration and functional recovery in mice. The mechanism underlying this effect may be associated with the upregulation of growth-associated protein-43 expression.

Use of acupuncture to treat cerebral infarction in the last 10 years A Scopus-based literature analysis

OBJECTIVE： To identify global research trends in the use of acupuncture to treat cerebral infarction. DATA RETRIEVAL： We performed a bibliometric analysis of studies on the use of acupuncture to treat cerebral infarction published during 2002-2011, retrieved from Scopus, using the key words of acupuncture and cerebral infarction or ischemic stroke. SELECTION CRITERIA： Inclusion criteria： peer-reviewed articles on the use of acupuncture to treat cerebral infarction indexed in Scopus and published between 2002 and 2011; types of publications were original research articles, reviews, meeting abstracts, proceedings papers, book chapters, editorial material, and news items. Exclusion criteria： articles that required manual searching or telephone access; documents that were not published in the public domain; and corrected papers. MAIN OUTCOME MEASURES： （a） Annual publication output; （b） language of publication; （c） type of publication; （d） key words of publication; （e） publication by research field; （f） publication by journal （g） publication by country and institution; （h） publication by author; （i） most-cited papers between 2002 and 2006; and （j） most-cited papers between 2007 and 2011. RESULTS： A total of 160 publications on the use of acupuncture to treat cerebral infarction from 2002-2011 were retrieved from Scopus. The number of publications increased gradually over the 10-year study period; most were written in Chinese or English. Articles and reviews constituted the major types. The most frequent key word used was acupuncture. The most prolific journals in this area were Zhongguo 7hen Jiu and the Chinese Journal of Clinical Rehabilitation. Of the 160 publications retrieved, half came from Chinese authors and institutions. Tianjin University of Traditional Chinese Medicine was the most prolific research institute. Two papers were cited 30 times; they were published in 2002 and 2009, respectively. CONCLUSION： In the field of neuroscience, there is little literature on acupuncture for cerebral infarction. The most-cited papers were cited 30 times in the past 3 years. We believe that, with advances in the study of mechanisms in neurobiology, research on acupuncture will also advance and will become the concern of more scholars.

Ursolic acid induces neural regeneration after sciatic nerve injury

In this study, we aimed to explore the role of ursolic acid in the neural regeneration of the injured sciatic nerve. BALB/c mice were used to establish models of sciatic nerve injury through unilateral sciatic nerve complete transection and microscopic anastomosis at 0.5 cm below the ischial tuber-osity. The successful y generated model mice were treated with 10, 5, or 2.5 mg/kg ursolic acid via intraperitoneal injection. Enzyme-linked immunosorbent assay results showed that serum S100 protein expression level gradual y increased at 1-4 weeks after sciatic nerve injury, and significantly decreased at 8 weeks. As such, ursolic acid has the capacity to significantly increase S100 protein expression levels. Real-time quantitative PCR showed that S100 mRNA expression in the L 4-6 segments on the injury side was increased after ursolic acid treatment. In addition, the muscular mass index in the soleus muscle was also increased in mice treated with ursolic acid. Toluidine blue staining revealed that the quantity and average diameter of myelinated nerve fibers in the injured sciatic nerve were significantly increased after treatment with ursolic acid. 10 and 5 mg/kg of ursolic acid produced stronger effects than 2.5 mg/kg of ursolic acid. Our findings indicate that ursolic acid can dose-dependently increase S100 expression and promote neural regeneration in BALB/c mice fol owing sciatic nerve injury.

Zhichan powder regulates nigrostriatal dopamine synthesis and metabolism in Parkinson's disease rats

In this study, rat models of Parkinson＇s disease induced by substantia nigra injection of 6-hydroxy-dopamine were intragastrically administered Zhichan powder daily for 50 days. Reverse transcription PCR results showed that tyrosine hydroxylase mRNA expression in the rat substantia nigra was significantly increased, while monoamine oxidase B mRNA expression was significantly decreased in the Zhichan powder group, compared with the model group. In addition, the levels of striatal dopamine and homovanillic acid, the ratio of dopamine to homovanillic acid, and the activity of blood superoxide dismutase were all higher in the Zhichan powder group than in the model group but the content of malondialdehyde in blood was lower. Our experimental findings indicate that Zhichan powder has an antioxidant effect, it can regulate the expression of monoamine oxidase B and tyrosine hydroxylase in the substantia nigra of Parkinson＇s disease rats, and it can facilitate the secretion of striatal dopamine and its metabolite homovanillic acid.

Stem cell transplantation for treating stroke:status,trends and development

The developing approaches of thrombolytic therapy, endovascular treatment, neuroprotective therapy, and stem cell therapy have enabled breakthroughs in stroke treatment. In this study, we summarize and analyze trends and progress in stem cell transplantation for stroke treatment by retrieval of literature from Thomson Reuters Web of Science database, the NIH Clinical Trial Planning Grant Program, and Clinical Trials Registration Center in North America. In the last 10 years, there has been an increasing number of published articles on stem cell transplantation for stroke treatment. In particular, research from the USA and China has focused on stem cell transplantation. A total of 2,167 articles addressing stem cell transplantation for stroke treatment from 2004 to 2013 were retrieved from the Thomson Reuters Web of Science database. The ma- jority of these articles were from the USA （854, 39.4%）, with the journal Stroke publishing the most articles （145, 6.7%）. Of the published articles, 143 were funded by the National Institutes of Health （accounting for 6.6% of total publications）, and 91 by the National Natural Science Foundation of China. Between 2013 and 2014, the National Institutes of Health provided finan- cial support （$130 million subsidy） for 329 research projects on stroke therapy using stem cell transplantation. In 2014, 215 new projects were approved, receiving grants of up to $70,440,000. Ninety clinical trials focusing on stem cell transplantation for stroke were registered in the Clinical Trial Registration Center in North America, with 40 trials registered in the USA （ranked first place）. China had the maximum number of registered research or clinical trials （10 projects）.

Effects of Zhichan powder on signal transduction and apoptosis-associated gene expression in the substantia nigra of Parkinson's disease rats

Previous studies have shown that Zhichan powder elevated immunity and suppressed oxidation in mice. Rat models of Parkinson＇s disease were induced by stereotaxically injecting 6-hydroxydopamine into the substantia nigra. The rat models were intragastrically treated with Zhichan powder, which is composed of milkvetch root, ginseng, bunge swallowwort root, himalayan teasel root. Magnolia officinalis, Ligustrum lucidum Ait. and szechwan Iovage rhizome. Immunohistochemistry and reverse transcription-PCR results demonstrated that mRNA and protein expression of tumor necrosis factor receptor 1, Fas, caspase-8, cvtochrome C, Bax, casDase-3, and p53 significantly increased, but Bcl-2 expression significantly decreased in the substantia nigra of rats with Parkinson＇s disease. Following Zhichan powder administration, mRNA and protein expression of tumor necrosis factor receptor 1, Fas, caspase-8, cytochrome C, Bax, caspase-3, and p53 diminished, but Bcl-2 expression increased in the rat substantia nigra. These results indicate that Zhichan powder regulates signal transduction protein expression, inhibits apoptosis, and exerts therapeutic effects on Parkinson＇s disease.

Matrix-based method for solving decision domains of neighbourhood multigranulation decision-theoretic rough sets

It is more and more important to analyse and process complex data for gaining more valuable knowledge and making more accurate decisions.The multigranulation decision theory based on conditional probability and cost loss has the advantage of processing decision-making problems from multi-levels and multi-angles,and the neighbourhood rough set model(NRS)can facilitate the analysis and processing of numerical or mixed type data,and can address the limitation of multigranulation decision-theoretic rough sets(MG-DTRS),which is not easy to cope with complex data.Based on the in-depth study of hybrid-valued decision systems and MG-DTRS models,this study analysed neigh-bourhood MG-DTRS(NMG-DTRS)deeply by fusing MG-DTRS and NRS;a matrix-based approach for approximation sets of NMG-DTRS model was proposed on the basis of the matrix representations of concepts;the positive,boundary and negative domains were constructed from the matrix perspective,and the concept of positive decision recognition rate was introduced.Furthermore,the authors explored the related properties of NMG-DTRS model,and designed and described the corresponding solving algorithms in detail.Finally,some experimental results that were employed not only verified the effectiveness and feasibility of the proposed algorithm,but also showed the relationship between the decision recognition rate and the granularity and threshold.

Fano Resonance Enabled Infrared Nano-Imaging of Local Strain in Bilayer Graphene

Detection of local strain at the nanometer scale with high sensitivity remains challenging.Here we report near-field infrared nano-imaging of local strains in bilayer graphene by probing strain-induced shifts of phonon frequency.As a non-polar crystal,intrinsic bilayer graphene possesses little infrared response at its transverse optical phonon frequency.The reported optical detection of local strain is enabled by applying a vertical electrical field that breaks the symmetry of the two graphene layers and introduces finite electrical dipole moment to graphene phonon.The activated phonon further interacts with continuum electronic transitions,and generates a strong Fano resonance.The resulted Fano resonance features a very sharp near-field infrared scattering peak,which leads to an extraordinary sensitivity of-0.002%for the strain detection.Our results demonstrate the first nano-scale near-field Fano resonance,provide a new way to probe local strains with high sensitivity in non-polar crystals,and open exciting possibilities for studying strain-induced rich phenomena.

A plastic stabilizer dibutyltin dilaurate induces subchronic neurotoxicity in rats

Dibutyltin dilaurate functions as a stabilizer for polyvinyl chloride. In this study, experimental rats were intragastrically administered 5, 10, or 20 mg/kg dibutyltin dilaurate to model sub-chronic poisoning. After exposure, our results showed the activities of superoxide dismutase and glutathione peroxidase decreased in rat brain tissue, while the malondialdehyde and nitric oxide content, as well as nitric oxide synthase activity in rat brain tissue increased. The cell cycle in the right parietal cortex was disordered and the rate of apoptosis increased. DNA damage was aggravated in the cerebral cortex, and the ultrastructure of the right parietal cortex tissues was altered. The above changes became more apparent with exposure to increasing doses of dibutyltin dilaurate. Our experimental findings confirmed the neurotoxicity of dibutyltin dilaurate in rat brain tissues, and demonstrated that the poisoning was dose-dependent.

Near-Field Optical Identification of Metallic and Semiconducting Single-Walled Carbon Nanotubes

Single-walled carbon nanotubes(SWCNTs),due to their outstanding electrical and optical properties,are expected to have extensive applications,such as in transparent conductive fims and ultra-small field-effect transistors(FETs).However,those applications can only be best realized with pure metallic or pure semiconducting SWCNTs.Hence,identifying and separating metallic from semiconducting SWCNTs in as-grown samples are crucial.In addition,knowledge of the type of an SWCNT is also important for further exploring its new properties in fundamental science.Here we report employing scanning near-field optical microscopy(SNOM)as a direct and simple method to identify metallic and semiconducting SWCNTs on SiO2/Si substrates.Metallic and semiconducting SWCNTs show distinct near-field optical responses because the metallic tubes support plasmons whereas the semiconducting tubes do not.The reliability of this method is verified using FET testing and Rayleigh scattering spectroscopy.Our result demonstrates that the SNOM technique provides a reliable,simple,noninvasive and in situ method to distinguish between metallic and semiconducting SWCNTs.

Metal Uptake by Plants from Soil Contaminated by Thin-Film Solar Panel Material

Various metals, including zinc (Zn), nickel (Ni), aluminum (Al), chromium (Cr), gallium (Ga), lead (Pb), copper (Cu) and indium (In), may be released and cause contamination when scrapped end-of-life (EoL) Cu(InGa)Se2 thin-film solar panel (CIGS TFSP) is buried in the soil. In this study, we grew Brassica parachinensis L. H. Bariley (VegBrassica) in three different types of soils, namely, a commercial soil, a Mollisol, and an Oxisol, which had been contaminated by CIGS TFSP to various extents. The concentrations of contaminants in these soils were positively correlated with both the amount of CIGS TFSP added and the burial period. Plants grew well in commercial soil and Mollisol, but those in Oxisol showed prominent signs of chlorosis and died after 30 days. The bioaccumulation factor (BF) and concentration of Zn in VegBrassica grown in commercial soil with 10% of CIGS TFSP added were 3.61 and 296 mg/kg, respectively, while the BF and concentration of In of VegBrassica grown in Mollisol were 3.80 and 13.72 mg/kg, respectively. The results showed that soils were contaminated by metals released from CIGS TFSP, and different adsorption patterns were observed for VegBrassica?depending on which types of metals associated with the soil properties.

Real-time Risk-averse Dispatch of an Integrated Electricity and Natural Gas System via Condi-tional Value-at-risk-based Lookup-table Ap-proximate Dynamic Programming

The real-time risk-averse dispatch problem of an integrated electricity and natural gas system(IEGS)is studied in this paper.It is formulated as a real-time conditional value-at-risk(CVaR)-based risk-averse dis-patch model in the Markov decision process framework.Because of its stochasticity,nonconvexity and nonlinearity,the model is difficult to analyze by traditional algorithms in an acceptable time.To address this non-deterministic polynomial-hard problem,a CVaR-based lookup-table approximate dynamic programming(CVaR-ADP)algo-rithm is proposed,and the risk-averse dispatch problem is decoupled into a series of tractable subproblems.The line pack is used as the state variable to describe the impact of one period’s decision on the future.This facilitates the reduction of load shedding and wind power curtailment.Through the proposed method,real-time decisions can be made according to the current information,while the value functions can be used to overview the whole opti-mization horizon to balance the current cost and future risk loss.Numerical simulations indicate that the pro-posed method can effectively measure and control the risk costs in extreme scenarios.Moreover,the decisions can be made within 10 s,which meets the requirement of the real-time dispatch of an IEGS.Index Terms—Integrated electricity and natural gas system,approximate dynamic programming,real-time dispatch,risk-averse,conditional value-at-risk.

鹦鹉热衣原体肺炎的临床和CT影像特征

该研究回顾性分析2021年6月至2022年2月在浙江省丽水市中心医院采用宏基因组二代测序技术(mNGS)诊断为15例鹦鹉热衣原体肺炎患者的临床及CT影像资料。15例患者均有禽类接触史, 均以发热就诊, 病情进展快, 实验室检查中C反应蛋白(CRP)及中性粒细胞比例升高者15例(15/15), 其中CRP最大值超过200 mg/L者8例(8/15), 白细胞计数正常10例(10/15)、升高5例(5/15)。早期CT表现主要为肺部局限性结节或斑片状实变影, 可出现"晕征", 2~5 d快速进展为大叶性实变影, 以胸膜下分布为主, 病灶实变影周边常见"细网格征", 常伴有胸腔积液。该研究提示鹦鹉热衣原体肺炎的临床及CT表现具有一定的特征, 但仅依靠CT表现诊断困难, 对于高热患者, 临床提示CRP、中性粒细胞比例升高而白细胞计数不升高时, 且具有鸟类或禽类接触史, 需考虑该病的可能, 尽早行mNGS检测病原体, 使患者及时得到精准治疗。

Genetic improvement toward nitrogen-use efficiency in rice: Lessons and perspectives

The indispensable role of nitrogen fertilizer in ensuring world food security together with the severe threats it poses to the ecosystem makes the usage of nitrogen fertilizer a major challenge for sustainable agriculture.Genetic improvement of crops with high nitrogen-use efficiency(NUE)is one of the most feasible solutions for tackling this challenge.In the last two decades,extensive efforts toward dissecting the variation of NUE-related traits and the underlying genetic basis in different germplasms have been made,and a series of achievements have been obtained in crops,especially in rice.Here,we summarize the approaches used for genetic dissection of NUE and the functions of the causal genes in modulating NUE as well as their applications in NUE improvement in rice.Strategies for exploring the variants controlling NUE and breeding future crops with“less-input-more-output”for sustainable agriculture are also proposed.

C_(19)-二萜生物碱官能化A/E双环的不对称合成

C_(19)-二萜生物碱是一类具有重要生物活性的天然产物,在结构上以复杂的笼状骨架和稠密的取代基团为特点.相似的A/E氮杂桥环体系普遍存在于C_(19)-二萜生物碱中,其高效制备是合成相应天然产物的重要基础.本研究从非手性前体出发,通过去对称化、立体选择性烯丙基化、Aldol羟甲基化及还原胺化反应等关键步骤,完成了C_(19)-二萜生物碱官能化A/E双环的不对称合成.