微/纳米多孔低介电聚酰亚胺薄膜的研究进展

聚酰亚胺(PI)作为高性能聚合物,已成为5G通信的重要原材料之一。传统PI薄膜的介电常数处于3.0~3.4之间,随着电路集成度越来越高,已无法满足高速发展的微电子工业的要求,因此,开发综合性能优异的低介电PI薄膜已成为研究热点。向PI薄膜中引入微/纳米级的分散孔隙,可以有效降低介电常数,同时保留薄膜优异的综合性能。文中从物理和化学制备方法入手,综述了近年来国内外微/纳米多孔低介电PI薄膜(M/N-PLD-PI)的制备工艺,阐明了引入微/纳米级的分散孔隙对降低PI薄膜介电常数的贡献,并对多孔低介电PI薄膜的发展进行了展望。

Subsurface banding of blended controlled-release urea can optimize rice yields while minimizing yield-scaled greenhouse gas emissions

Controlled-release urea(CRU)is widely reported to supply crop nitrogen(N)demand with one basal application,thus effectively replacing split applications of urea without diminishing grain yield and N use efficiency(NUE).However,its use for replacement for high-yield split applications of urea(CK)for rice is untested.In addition,the degree to which greenhouse gas(GHG)emissions in rice systems are affected when CRU is substituted for CK remains unclear.During 2017 and 2018,we sampled plant growth and gas emissions in a rice paddy field treated with three CRU types(sulfur-coated urea[SCU],polymer-coated urea[PCU],and bulk blended CRU[BBU])applied via two methods(surface broadcasting on the soil and subsurface banding at 5 cm depth),with CK as a control.The three CRUs led to different soil NH_(4)^(+)-N dynamics,and the N supply pattern under BBU was more beneficial for rice seedling establishment than under SCU and PCU,resulting in grain yield and NUE comparable to those under CK.CRU type showed no significant effect on either CH_(4) emissions or N_(2)O emissions,and broadcast CRUs exhibited significantly higher total GHG emissions than CK.However,banded CRUs significantly reduced the total GHG emissions in comparison with broadcast CRUs,by 9.2%averaged across the two years.Reduced CH_(4) emissions,particularly during the period prior to the middle drainage,contributed largely to the GHG difference.With comparably high grain yield and low total GHG emissions,banded BBU showed a low yield-scaled GHG(GHG emissions divided by grain yield)comparable to that under CK in both years.Overall,our study suggested that N management synchronized with rice demand and contributing to a high NUE tended to minimize yield-scaled GHG.Broadcast CRU can hardly substitute for CK in terms of either grain yield or GHG emissions,but banded BBU is a promising N management strategy for sustaining rice production while minimizing environmental impacts.

仙灵骨葆胶囊联合阿霉素局部注射治疗骨性膝关节炎疼痛的临床价值

目的评价阿霉素局部注射联合仙灵骨葆胶囊治疗骨性膝关节炎疼痛的有效性及对血清炎症因子的影响。方法选取2015年9月-2016年9月我院收治的106例骨性膝关节炎合并顽固性疼痛患者,采用随机数字表法分为对照组及研究组,每组各53例,对照组采用仙灵骨葆胶囊治疗,研究组采用仙灵骨葆胶囊和阿霉素局部刺激注射治疗,比较两组患者治疗前后临床症状改善、临床疗效,治疗前后血清白介素-8(IL-8)、肿瘤坏死因子-α(TNF-α)因子变化。结果治疗前,两组患者疼痛、肿胀及活动障碍评分比较无明显差异(P>0.05);治疗后,两组患者疼痛、肿胀及活动障碍评分较之治疗前均显著降低,且研究组降低幅度较之对照组更显著(P<0.05)。研究组患者治疗总有效率96.22%,明显高于对照组(79.25%)(P<0.05)。治疗前,两组患者血清IL-8、TNF-α水平比较差异无统计学意义(P>0.05);治疗后,研究组患者的血清IL-8、TNF-α水平均明显低于对照组(P<0.05)。两组不良反应发生率比较无明显差异(P>0.05)。结论阿霉素局部注射联合仙灵骨葆胶囊治疗骨性膝关节炎疼痛疗效显著,可有效改善患者临床症状,降低炎症因子表达水平,不良反应少,值得应用及推广。

In Situ Synthesis of Fluorescent Mesoporous Silica–Carbon Dot Nanohybrids Featuring Folate Receptor-Overexpressing Cancer Cell Targeting and Drug Delivery

Multifunctional nanocarrier-based theranostics is supposed to overcome some key problems in cancer treatment.In this work,a novel method for the preparation of a fluorescent mesoporous silica–carbon dot nanohybrid was developed.Carbon dots(CDs),from folic acid as the raw material,were prepared in situ and anchored on the surface of amino-modified mesoporous silica nanoparticles(MSNs–NH2) via a microwave-assisted solvothermal reaction.The as-prepared nanohybrid(designated MSNs–CDs) not only exhibited strong and stable yellow emission but also preserved the unique features of MSNs(e.g.,mesoporous structure,large specific surface area,and good biocompatibility),demonstrating a potential capability for fluorescence imagingguided drug delivery.More interestingly,the MSNs–CDs nanohybrid was able to selectively target folate receptor-overexpressing cancer cells(e.g.,HeLa),indicating that folic acid still retained its function even after undergoing the solvothermal reaction.Benefited by these excellent properties,the fluorescent MSNs–CDs nanohybrid can be employed as a fluorescence-guided nanocarrier for the targeted deliveryof anticancer drugs(e.g.,doxorubicin),thereby enhancing chemotherapeutic efficacy and reducing side effects.Our studies may provide a facile strategy for the fabrication of multifunctional MSN-based theranostic platforms,which is beneficial in the diagnosis and therapy of cancers in future.

Molecularly tagged genes and quantitative trait loci in cucumber with recommendations for QTL nomenclature

Cucumber,Cucumis sativus L.(2n=2x=14),is an important vegetable crop worldwide.It was the first specialty crop with a publicly available draft genome.Its relatively small,diploid genome,short life cycle,and selfcompatible mating system offers advantages for genetic studies.In recent years,significant progress has been made in molecular mapping,and identification of genes and QTL responsible for key phenotypic traits,but a systematic review of the work is lacking.Here,we conducted an extensive literature review on mutants,genes and QTL that have been molecularly mapped or characterized in cucumber.We documented 81 simply inherited trait genes or major-effect QTL that have been cloned or fine mapped.For each gene,detailed information was compiled including chromosome locations,allelic variants and associated polymorphisms,predicted functions,and diagnostic markers that could be used for marker-assisted selection in cucumber breeding.We also documented 322 QTL for 42 quantitative traits,including 109 for disease resistances against seven pathogens.By alignment of these QTL on the latest version of cucumber draft genomes,consensus QTL across multiple studies were inferred,which provided insights into heritable correlations among different traits.Through collaborative efforts among public and private cucumber researchers,we identified 130 quantitative traits and developed a set of recommendations for QTL nomenclature in cucumber.This is the first attempt to systematically summarize,analyze and inventory cucumber mutants,cloned or mapped genes and QTL,which should be a useful resource for the cucurbit research community.

Constraints of molybdenite Re-Os and scheelite Sm-Nd ages on mineralization time of the Kukaazi Pb-Zn-Cu-W deposit, Western Kunlun, NW China

The Kukaazi Pb-Zn-Cu-W polymetallic deposit, located in the Western Kunlun orogenic belt, is a newly discovered skarn-type deposit. Ore bodies mainly occur in the forms of lenses and veins along beddings of the Mesoproterozoic metamorphic rocks. Three ore blocks, KⅠ,KⅡ, and KⅢ, have been outlined in different parts of the Kukaazi deposit in terms of mineral assemblages. The KⅠ ore block is mainly composed of chalcopyrite, scheelite,pyrrhotite, sphalerite, galena and minor pyrite, arsenopyrite,and molybdenite, whereas the other two ore blocks are made up of galena, sphalerite, magnetite and minor arsenopyrite and pyrite. In this study, we obtained a molybdenite isochron Re–Os age of 450.5 ± 6.4 Ma(2σ,MSWD = 0.057) and a scheelite Sm–Nd isochron age of 426 ± 59 Ma(2σ, MSWD = 0.49) for the KⅠ ore block.They are broadly comparable to the ages of granitoid in the region. Scheelite grains from the KⅠ ore block contain high abundances of rare earth elements(REE, 42.0–95.7 ppm)and are enriched in light REE compared to heavy REE, with negative Eu anomalies(δEu = 0.13–0.55). They display similar REE patterns and Sm/Nd ratios to those of the coeval granitoids in the region. Moreover, they also have similar Sr and Nd isotopes [ ^(87)Sr/ ^(86)Sr = 0.7107–0.7118;ε_(Nd)(t) =-4.1 to-4.0] to those of such granitoids, implying that the tungsten-bearing fluids in the Kukaazi deposit probably originate from the granitic magmas. Our results first defined that the Early Paleozoic granitoids could lead to economic Mo–W–(Cu) mineralization at some favorable districts in the Western Kunlun orogenic belt and could be prospecting exploration targets.

Inhibitory effects of lidocaine on cerebral vasospasm in a rabbit model of subarachnoid hemorrhage

Following subarachnoid hemorrhage, vasoconstrictor substances, cellular apoptosis, blood coagulation, and vascular cell proliferation affect the onset of cerebral vasospasm. Previous studies from our laboratory have revealed that injection of lidocaine （2 mg） into the cisterna magna reduces cerebral vasospasm and nerve functional impairment in an animal model of subarachnoid hemorrhage. The present study determined the optimal lidocaine dose for vasospasm and brain injury by injecting different doses of lidocaine into the cisterna magna in a rabbit model of subarachnoid hemorrhage. Results showed that endothelin, tumor necrosis factor-a, and interleukin-6 levels significantly increased in plasma, and calcitonin gene-related peptide levels significantly decreased in plasma （P 〈 0.05）. The number of neurons was decreased, the number of cells expressing c-Fos increased in the hippocampus, and cross-sections and diameters of basilar arteries were reduced （P 〈 0.05）. These changes significantly improved following injection of lidocaine （1,2, 4, and 6 mg） into the cisterna magna. A dose of 6 mg lidocaine into the cisterna magna resulted in optimal effects on cerebral vasospasm and brain injury following subarachnoid hemorrhage.

Winning Probability Estimation Based on Improved Bradley-Terry Model and Bayesian Network for Aircraft Carrier Battle

To provide a decision-making aid for aircraft carrier battle,the winning probability estimation based on Bradley-Terry model and Bayesian network is presented. Firstly,the armed forces units of aircraft carrier are classified into three types,which are aircraft,ship and submarine. Then,the attack ability value and defense ability value for each type of armed forces are estimated by using BP neural network,whose training results of sample data are consistent with the estimation results. Next,compared the assessment values through an improved Bradley-Terry model and constructed a Bayesian network to do the global assessment,the winning probabilities of both combat sides are obtained. Finally,the winning probability estimation for a navy battle is given to illustrate the validity of the proposed scheme.

Establishment of a rat model with diet-induced coronary atherosclerosis

Coronary atherosclerotic disease is a serious disease in humans,but no suitable animal model is available currently for further studies.We used apolipoprotein E gene knockout（ApoE KO） rats to induce hypercholesterolemia through a special high cholesterol/bile salt diet（Paigen diet）,then analyzed aortic and coronaiy atherosclerosis lesions and the myocardial injury in order to establish a novel small animal model of coronary atherosclerosis.Plasma cholesterol of ApoE KO rats increased 7.6-fold compared with wild-type rats after 8 weeks on the Paigen diet.After 10 to 12 weeks of subsisting on the Paigen diet,ApoE KO rats developed mild aortic atherosclerosis with severe coronary atherosclerosis.Hematoxilyn and eosin staining showed that 11 out of 12 ApoE KO male rats had right coronary artery atherosclerosis,7 of them were〉70%occluded.Oil Red O（Lipid Stain）,Mac2 immuno-staining and Masson＇s tnchrome staining demonstrated substantial amounts of lipid,macrophages and collagen fibers in coronary atherosclerosis plaques.In addition,ApoE KO male rats had severe myocardial focal lesions with cholesterol ester as the main component in the lesions.In conclusion,ApoE KO rats developed severe hypercholesterolemia,coronary atherosclerosis and myocardial cholesterol ester deposition after subsisting on the Paigen diet and can be used as a novel animal model for studies on cholesterol metabolism and coronary atherosclerotic disease.

Gynoecy instability in cucumber(Cucumis sativus L.)is due to unequal crossover at the copy number variation-dependent Femaleness(F)locus

Cucumber,Cucumis sativus is an important vegetable crop,and gynoecy has played a critical role in yield increase of hybrid cucumber production.Cucumber has a unique genetic system for gynoecious sex expression,which is determined by the copy number variation(CNV)-based,dominant,and dosage-dependent femaleness(F)locus.However,this gynoecy expression system seems unstable since monecious plants could often be found in Fdependent gynoecious cucumber inbreds.We hypothesized that gynoecy instability(gynoecy loss)may be due to unequal crossing over(UCO)during meiosis among repeat units of the CNV.In this study,using high throughput genome resequencing,fiber-FISH and genomic qPCR analyses,we first confirmed and refined the structure of the F locus,which was a CNV of a 30.2-kb tandem repeat.Gynoecious plants contained three genes:CsACS1,CsACS1G,and CsMYB,of which CsACS1G is a duplication of CsACS1 but with a recombinant distal promoter that may contribute to gynoecy sex expression.In two large populations from self-pollinated gynoecious inbred lines,‘gynoecy loss’mutants were identified with similar mutation rates(~0.12%).We show that these monecious mutants have lost CsACS1G.In addition,we identified gynoecious lines in natural populations that carry two copies of CSACS1G.We proposed a model to explain gynoecy instability in F-dependent cucumbers,which is caused by UCO among CSACS1/G units during meiosis.The findings present a convincing case that the phenotypic variation of an economically important trait is associated with the dynamic changes of copy numbers at the F locus.This work also has important implications in cucumber breeding.

Status of Vitamin B12 Deficiency in the Elderly Chinese Community People

This study was aimed to investigate the vitamin B12 deficiency prevalence and symptoms in elderly people lived in a community of Shanghai, China. A total number of 962 elderly people resided in Shanghai community were recruited in the present study. They were 60 years and older, and the average age was 76.38 ± 13.68 years old. Information on previous and present diseases, currently prescribed and over-the-counter medication, and the presence or absence of symptoms relating to vitamin B12 deficiency were obtained by questionnaire. The levels of serum vitamin B12, folate and homocysteine (Hcy) were estimated. The patients with vitamin B12 deficiency were screened. The results of symptoms and positive signs of neurological examination were compared between subjects with or without vitamin B12 deficiency. The results showed that vitamin B12 deficiency was found in 130 persons (13.53% of the total subjects), with an increase in incidence with aging, only 10% of the vitamin B12 deficient subjects had megaloblastic anemia. The reported symptoms of vitamin B12 deficient subjects included fatigue, memory decline, dizziness, unsteadily walking in the darkness and hypopallesthesia. In conclusion, vitamin B12 deficiency was remarkably common in Chinese elderly people, with various and atypical clinical manifestations, and the neurological symptoms were more common than those of megaloblastic anemia.

A Uniform Parcel Delivery System Based on IoT

Nowadays, many different kinds of delivery companies transport their own kinds of parcels and offer their own services, which have caused a lot waste of resources. In addition, the volume of parcels in all cities that need to be delivered has been grown dramatically. To cope with these problems, a uniform parcel delivery system in a smart city which can offer service to all kinds of customers in the city including manufactures, department stores, restaurants, individual people and so forth was designed. This system uses IoT (Internet of Things) and RFID technology, combining computer network technology, wireless communication and cloud computing. With this system, the whole package delivery process including classification of packages, vehicle scheduling, path planning, transportation monitoring can be intellectualized as well as managed automatically, and the use of both material resources and manpower resources can be reduced accordingly.

A mutation in CsKTN1 for the Katanin p60 protein results in miniature plant in cucumber,Cucumis sativus L.

Katanin,a microtubule shearing protein,plays an important role in plant architecture formation.However,little is known about its mechanisms in regulating plant architecture in cucumber.In the present study,through EMS mutagenesis,we identified a novel micro-plant(mp)mutant in the North China type inbred line CCMC that may be of value for cucumber breeding.The size and number of stem cells were altered in the mp mutant.Through bulked segregant analysis(BSA)sequencing approach combined with genetic mapping,the mp locus was delimited to an interval of 130.9-kb.Multiple lines of evidence suggested that the mp mutation is due to a single nucleotide polymorphism in Csa7G435510 that is predicted to encode the Katanin p60 subunit protein(CsKTN1).The expression levels of CsKTN1 decreased significantly in all tissues except the tendril of mp mutant.Subcellular localization showed that both wild-type and mutant CsKTN1 proteins were located in cell membrane,cytoplasm and nucleus of tobacco leaf cells.The mutant protein lost part of its ability to bind and shear microtubule in vitro.These findings provide new insight into the regulatory function of microtubule-shearing protein,Katanin p60,in plant architecture of cucumber.

高效光催化二氧化碳还原钻单原子催化剂的多尺度结构工程

人工光合作用将二氧化碳转化为增值化学品和燃料,在克服全球环境能源危机方面具有巨大潜力.然而,由于CO_(2)的热力学稳定性和动力学滞后性,开发高效的CO_(2)RR光催化剂是一个巨大的挑战.本文在微介孔氮掺杂碳(0.8-Co-ISAS/MMNC-900)上制备了一种具有高度分散Co单原子位的分级多孔钴单原子光催化剂,该催化剂显著促进了CO_(2)-to-CO的光还原.0.8-Co-ISAS/MMNC-900催化剂的CO生成速率高达7261μmol g^(-1)h^(-1),CO选择性高达90.1%,并且在四次循环测试中表现出良好的稳定性.实验数据和理论结果表明,分层多孔结构可以促进电荷分离引起的外部局部电场的形成,Co隔离的单原子位和微介孔构型协同作用,促进光激发电子积累、CO_(2)吸附活化和*COOH中间体的形成.本研究通过多尺度多孔结构工程,提出了一种合成CO_(2)还原光催化剂的新策略.

Effects of in-situZrB_2 nanoparticles and scandium on microstructure and mechanical property of 7N01 aluminum alloy

In this study, the in-situ synthesized ZrB_(2) nanoparticles and rare earth Sc were introduced to enhance the strength and ductility of 7N01 aluminum alloy, via the generation of high-melting and uniform nanodispersoids. The microstructure and mechanical property evolution of the prepared composites and the interaction between ZrB_(2) and Sc were studied in detail. The microstructure investigation shows that the introduction of rare earth scandium(Sc) can promote the distribution of ZrB_(2) nanoparticles, by improving their wettability to the Al melt. Meanwhile, the addition of rare earth Sc also modifies the coarse Al Zn Mg Mn Fe precipitated phases, refines the matrix grains and generates high-melting Al_3(Sc,Zr)/Al_3Sc nanodispersoids. Tensile tests of the composites show that with the combinatorial introduction of ZrB_(2) and Sc, the strength and ductility of the composites are improved simultaneously compared with the corresponding 7N01 alloy, ZrB_(2) /7N01 composite and Sc/7N01 alloy. And the optimum contents of ZrB_(2) and Sc are 3 wt% and 0.2 wt% in this study. The yield strength, ultimate strength and elongation of(3 wt% ZrB_(2) +0.2 wt% Sc)/7N01 composite are 477 MPa, 506 MPa and 9.8%, increased about 18.1%, 12.2%and 38% compared to 7N01 alloy. Furthermore, the cooperation strengthening mechanisms of ZrB_(2) and Sc are also discussed.

A comprehensive review on surface modifications of black phosphorus using biological macromolecules

Black phosphorus(BP),a novel two dimensional material,exhibits remarkable photoelectric characteristics,ultrahigh photothermal conversion efficiency,substantial specific surface area,high carrier mobility,and tunable band gap properties.These attributes have positioned it as a promising candidate in domains such as energy,medicine,and the environment.Nonetheless,its vulnerability to light,oxygen,and water can lead to rapid degradation and loss of crystallinity,thereby limiting its synthesis,preservation,and application.Moreover,BP has demonstrated cytotoxic tendencies,substantially constraining its viability in the realm of biomedicine.Consequently,the imperative for surface modification arises to bolster its stability and biocompatibility,while concurrently expanding its utility spectrum.Biological macromolecules,integral components of living organisms,proffer innate advantages over chemical agents and polymers for the purpose of the BP modifications.This review comprehensively surveys the advancements in utilizing biological macromolecules for the modifications of BP.In doing so,it aims to pave the way for enhanced stability,biocompatibility,and diversified applications of this material.

A single-nucleotide substitution in the leucinerich-repeat-only gene CsLRR1 confers powdery mildew resistance in cucumber

Dear Editor,A variant with single substitution in the LRR-only protein CsLRR1,which regulates cucumber resistance to powdery mildew through a salicylic-acid-mediated pathway,provides a major source of resistance for cucumber breeding.Cucumber powdery mildew(PM),mainly caused by the biotrophic pathogen Podosphaera xanthii(synonym Podosphaera fusca),poses a serious threat to cucumber crops globally,leading to substantial reductions in fruit yield and quality(Martinez-Cruz et al.,2017).

Gene expression profiles contribute to robustly predicting prognosis in hepatocellular carcinoma

Hepatocellular carcinoma(HCC)is characterized by both inter-and intra-tumor heterogeneity and has distinct clinical outcomes.1 A promising clinical tool to perform patient stratification,prognosis evaluation,and treatment recommendations is indispensable.Here,we enrolled a total of 1595 tumor patients from 13 independent cohorts,including seven cohorts with survival data,four cohorts with immunotherapy information,and two cohorts with transcatheter arterial chemoembolization(TACE)and Sorafenib information,respectively(Table S1).Using 96 algorithms combinations derived from 10 popular machinelearning approaches,a novel framework was constructed and described in Figure S1.Firstly,a total of 26 stable consensus prognostic genes were screened in seven cohorts harboring complete survival information via univariate Cox regression analysis(Fig.S2A).

碳点基水相室温磷光复合材料研究进展

室温磷光(RTP)凭借较长的发光寿命和强烈的环境敏感特性,在化学/生物传感、生物成像、高级光学防伪与信息加密等诸多领域表现出广阔的应用前景。近些年,具有制备简单、化学惰性、低毒性、易功能化等优势的固态非金属室温磷光碳点获得了研究者的青睐。然而,其磷光发射易受水环境中溶解氧和水分子影响而淬灭,导致其应用局限于固态基质(如防伪油墨)。因而,如何稳定水相下碳点的激发三重态是实现其RTP发射与应用的关键。本文依据近年来碳点基水相RTP复合材料的最新研究进展,归纳总结了其构建策略及在传感、成像及防伪等方面的应用,并探讨了其面临的挑战及未来的发展方向。