负载聚集诱导发光光敏剂纳米纤维膜的制备及其抗菌性能

为解决光动力抗菌纤维活性氧(ROS)产率低、光敏剂易泄露等问题,以聚集诱导发光(AIE)分子(TPE-TCF)为光敏剂,与聚丙烯腈(PAN)、聚乙烯吡咯烷酮(PVP)共混,通过静电纺丝制备TPE-TCF@PAN/PVP纳米纤维膜,表征其化学结构、微观形貌和表面亲水性,并探究其ROS产率和抗菌效果。结果表明:TPE-TCF@PAN/PVP膜(TPE-TCF质量分数为0.4%)具有高亲水性、优异的光敏剂负载稳定性和高ROS产率,超低功率白光照射20 min后,可实现对金黄色葡萄球菌(抑菌率大于96.2%)和大肠杆菌(抑菌率大于99.9%)的高效灭菌。该研究结果可为高效广谱抗菌的医用防护材料的制备和应用提供参考。

分子聚集的变化:聚集诱导发光

随着科学技术的高速发展,不断取得科技创新和科学进步新成果,中学化学教学应及时更新教学素材。在高中化学晶体结构与性质中引导学生认识固态物质,特别是建立晶体的结构决定性质,这一认识模型。中国科学家发现并引领的前沿热点课题聚集诱导发光,主要涉及分子在固态时新奇的发光行为。因此,本文从高中化学晶体结构与性质延伸到科研前沿领域聚集诱导发光,介绍了聚集诱导发光现象的发现、机理与应用研究,以及其与高中化学教学和化学核心素养的联系。为化学前沿热点课题引入到中学化学教学和科技创新中提供素材和思路。

开发区的“硅谷”梦

节约集约用地的榜样力量是,全省开发区园区以约占全省3‰的土地,吸纳了全省1/3左右的外资,创造了全省约2/5的外贸出口额、1/5的工业增加值,1/12的城镇就业岗位,一个"寸土寸金"的硅谷之梦正圆。

Familial aggregation in inflammatory bowel disease:Is it genes or environment?

Inflammatory bowel disease (IBD) develops in genetically susceptible individuals due to the influence of environmental factors, leading to an abnormal recognition of microbiota antigens by the innate immune system which triggers an exaggerated immune response and subsequent bowel tissue damage. IBD has been more frequently found in families, an observation that could be due to either genetic, environmental or both types of factors present in these families. In addition to expanding our knowledge on IBD pathogenesis, defining the specific contribution to familial IBD of each one of these factors might have also clinical usefulness. We review the available evidence on familial IBD pathogenesis.

Study on Agglomeration and Fluctuation Situation and Development Countermeasures of Economic Crop Production in Hunan Province

[Objective] This paper aimed to investigate the agglomeration and fluctuation situation of economic crop production in Hunan Province and to propose related development countermeasures. [Method] With agglomeration index and fluctuation index as main indicators, the agglomeration and fluctuation situation of the production of seven major economic crops in Hunan Province in recent decade was studied. [Result] The agglomeration index of sown area and yield of seven major economic crops in Hunan Province showed decreasing orders of ramie 〉 cotton 〉 tobacco 〉 rape〉 citrus 〉 tea 〉 vegetables, ramie 〉 cotton 〉 tobacco 〉 tea 〉 rape 〉 citrus 〉 vegetables, respectively; the fluctuation index of sown area and yield showed decreasing orders of ramie 〉 citrus 〉 vegetables 〉 cotton 〉 tea 〉 rape 〉 tobacco, citrus 〉 ramie 〉 tea 〉 cotton 〉 rape 〉 tobacco 〉 vegetables, respectively. In addition, stable regions, relatively stabte regions and fluctuation regions of sown area and yield in various main producing areas were identified, and corresponding development countermeasures were proposed. [Cenclusion] The key to accelerate the development of major economic crop production in Hunan Province is further improving the agglomeration level of vegetable, citrus, rape and tea production and focusing on maintaining the stability of citrus, ramie and cotton production in main producing areas.

楚雄州人民政府关于推进农村安居工程示范村建设的指导意见

楚政发[2012]14号各县市人民政府,州直有关部门:提高民居建筑档次,改善农村居住条件,是统筹城乡发展,加快社会主义新农村建设的重要内容,也是已经解决了温饱问题、正向小康目标奋进的农民群众的迫切愿望和要求。进入新世纪以来,中央和省、州党委政府在加大"三农"

Aggregation-Induced Emission with Large Redshift in 2,7-Diphenylfluorenone:Reality or Artifact?

The luminescence property of 2,7-diphenyl-fluorenone(DPFO)was previously reported to be very unusual with a large aggregationinduced effect associated with a fluorescence redshift of 150 nm.The phenomenon is reexamined in this work.It is found that the abnormal observations are caused by the presence of a trace amount of impurity 2,7-diphenyl-fluorene(DPF)in the as-synthesized DPFO.The pure DPFO molecule does have an intense fluorescence(FL)in solid(528 nm),about 4−5 times larger than in its dilute dichloromethane solutions(542 nm),but with a blueshifted rather than redshifted FL wavelength in solid.The enormous FL enhancement and redshifted FL wavelength of the as-synthesized DPFO solid are due to the presence of impurity DPF.The FL of DPF is much stronger than that of DPFO in dilute solutions and it also has shorter FL wavelengths.In a dilute solution of DPFO with a trace amount of DPF(∼1%),the dominant FL peaks are from DPF.Because the electronic absorption peaks of DPF overlaps with DPFO,the electronic energy of DPF can transfer to DPFO.The energy transfer is faster with the increase of concentration because DPF and surrounding DPFO molecules become closer,which quenches the FL of DPF(356 and 372 nm)and enhances the FL of DPFO(542 nm in solution and 528 nm in solid).Therefore,at high concentrations or in solids,only peak at about 542 or 528 nm shows up,and peaks at 356 and 372 nm disappear.

Click-Formed Polymer Gels with Aggregation-Induced Emission and Dual Stimuli-Responsive Behaviors

Stimuli-responsive polymer gels have recently attracted great attention due to their heat/solvent resistance,dimensional stability,and unique sensitivity to external stimuli.In this work,we synthesized thiol-functionalized tetraphenylethylene(TPE)and constructed polymer gels through thiol-ene click reaction.The synthetic process of the polymer gels could be monitored by fluorescence emission of TPE moieties based on aggregation-induced emission mechanism.In addition,due to the dual redox-and acid responsiveness of the polymer gels,in the presence of dithiothreitol and trifluoroacetic acid,fluorescence quenching of the polymer gels can be observed.This stimuli-responsive characteristics endows the polymer gels with potential applications in fluorescent sensing and imaging,cancer diagnosis and selfhealing materials.

Intracellular Self-assembly of TPE-biotin Nanoparticles Enables Aggregation-Induced Emission Fluorescence for Cancer-Targeted Imaging

Fluorogens with aggregation-induced emission (AIE) characteristics have recently been widely applied for studying biological events, and fluorogens with “smart” properties are especially desirable. Herein, we rationally designed and synthesized a biotinylated and reduction-activatable probe (Cys(StBu)-Lys(biotin)-Lys(TPE)-CBT (1)) with AIE properties for cancer-targeted imaging. The biotinylated probe 1 can be actively uptaken by the biotin receptor-overexpressing cancer cells, and then “smartly” self-assemble into nanoparticles inside cells and turn the fluorescence “On”. Employing this “smart” strategy, we successfully applied probe 1 for cancer-targeted imaging. We envision that this biotinylated intelligent probe 1 might be further developed for cancer-targeted imaging in routine clinical studies in the near future.

Relationship Between Social Economic Agglomeration and Labor Productivity of Core Cities in Northeast China

Dalian, Shenyang, Changchun and Harbin are the four core cities which play an essential role in terms of promoting the economic development in Northeast China. In this paper, the impact of urban agglomeration on labor productivity is explored by making comparisons among these four cities. The model used for analysis is a classical model derived from previous studies. Some indicators, such as population density and economic density, were selected to examine the impact of urban agglomeration on the labor productivity based on the time-series data for the four cities from 1990 to 2007. The four main conclusions are： l） The promotion from the growth rate of population density on the growth rate of labor productivity is limited. 2） The negative relationship exists between the growth rate of employment density and the growth rate of labor productivity. 3） Agglomeration effect exists in the four cities, the highest one is Dalian, Shenyang takes the second place, followed by Changchun and Harbin, and the predominant promotion exerted on the labor productivity is the output density.

Effects of Intermolecular Interactions on Luminescence Property in Organic Molecules

The organic solid-state lightemitting materials have attracted more and more attention owing to their promising applications in displays,lasers and optical communications.In contrast to isolated molecule,there are various weak intermolecular interactions in organic solids that sometimes have a large impact on the excited-state properties and energy dissipation pathways,resulting in strong fluorescence/phosphorescence.It is increasingly necessary to reveal the luminescence mechanism of organic solids.Here,we briefly review how intermolecular interactions induce strong normal fluorescence,thermally activate delayed fluorescence and room-temperature phosphorescence in organic solids by examining changes in geometry,electronic structures,electron-vibration coupling and energy dissipation dynamics of the excited states from isolated to aggregated molecules.We hope that the review will contribute to an in-depth understanding of the excited state properties of organic solids and to the design of excellent solid-state light-emitting materials.

Effect of Gravity on Collective Excitations of a Quasi Two-Dimensional Bose Einstein Condensate in an Anharmonic Trap

Abstract Using variational method, the wave function of a quasi two-dimensional Bose-Einstein Condensate in an anharmonic trap is analyzed and the influence of gravity on the eollective excitations is studied. It is found that the effect of gravity on the condensate has got crucial dependence on the anharmonieity of the trap.

Economic Agglomeration Should Not Be Blamed for Widening Income Gaps in China

Agglomeration of economic activities is a common phenomenon across the world. Theoretical and empirical studies have shown that agglomeration promotes dynamic efficiency, which in turn is conducive to the long-term prosperity of a country＇s economy. Compared with most countries, in China is very low, and Chinese cities the spatial concentration of various industries are relatively small and equal-sized. Thus, it is unnecessary to contain the agglomeration of economic activities in China. Widening regional gaps since pro-market reforms and opening-up in China should be ascribed to institutional barriers rather than agglomeration. Therefore, China should refrain from containing agglomeration and instead focus on integrating product and factor markets and improving education and health care in less developed areas.

Incidence of pocket hematoma after electrophysiological device placement：dual antiplatelet therapy versus low-molecular-weight heparin regimen

Background Given the increasing number of patients who require dual antiplatelet （DAP） therapy and electrophysiological device （EPD） placement, perioperative antiplatelet management is a current challenge. In this study, we investigated the incidence of pocket hema-toma formation after EPD placement in patients undergoing DAP therapy or an alternative low-molecular-weight heparin （LMWH） regimen. Methods This clinical observational study was performed from July 2010 to July 2012. In total, 171 patients were enrolled in the analysis after meeting the inclusion criteria. These patients were divided into two groups： 86 patients were treated with DAP therapy at the time of device implantation, and the DAP therapy was discontinued for 5 to 7 days and replaced with enoxaparin before device implantation in the other 85 patients. Adenosine phosphate （ADP）-mediated platelet aggregation and arachidonic acid-induced platelet aggregation were tested preoperatively. We compared the incidence of pocket hematoma between the two groups and the association of pocket hematoma develop-ment with ADP-mediated platelet aggregation and arachidonic acid-induced platelet aggregation.Results The incidence of pocket hema-toma in the patients who continued DAP was lower than that in the patients who replaced the dual antiplatelet regimen with LMWH （3.49%vs. 16.47%, respectively;X2 = 6.66,P 〈 0.01）. Among the patients who continued DAP therapies, the rate of ADP-mediated platelet aggre-gation inhibition in patients with pocket hematomas was higher than that in patients without pocket hematomas. None of the patients under-going DAP or enoxaparin therapy developed pocket infection, thromboembolic events, or other serious complications. Multiple logistic re-gression analysis revealed that LMWH therapy was an independent risk factor for the development of pocket hematoma （RR = 0.054, 95%CI = 0.012-0.251）. Furthermore, patients undergoing LMWH therapy were 5.1-fold more likely to develop pocket hematomas than were DAP-treated individuals.Conclusion Continuance of DAP therapy does not increase the risk of pocket hematoma formation after EPD placement.

Industrial Agglomeration Externalities, City Size, and Regional Economic Development： Empirical Research Based on Dynamic Panel Data of 283 Cities and GMM Method

Local governments have long been ardently pursuing the industrial specialization effect(MAR externalities) and industrial diversification effect(Jacobs externalities). Such a pursuit has resulted in severe distortion of resource allocation and negative effect on sustainability of local economic development. Regarding the effect from both MAR and Jacobs externalities on local economic development existing literature records notable disputes. Therefore, for local economic development, one important issue is which externality(MAR or Jacobs) can better bring the effect into play. By studying a panel data of 283 Chinese cities from 2003 to 2012 and applying dynamic plane data GMM method, this paper conducted a regression analysis of the relationship among industrial agglomeration externalities, city size, and regional economic development. The result indicates that with regard to the whole nation, MAR externalities are conducive to regional economy development whereas Jacobs externalities will, to an extent, restrain regional economic development. As regards eastern, middle, and western regions, MAR externalities are conducive only to the economic development of the eastern region; their effects on middle and western regions are insignificant. Moreover, the interaction item between MAR externalities and city size has a significant negative synergistic effect on national economic development and a certain acceleration effect on eastern region as well as a strong negative synergistic effect on the middle region and an insignificant effect on the western region. The interaction item between Jacobs externalities and city size has a positive synergistic effect on only the middle region and has an insignificant synergistic effect on both eastern and western regions. Capital stock and labor input have significant accelerating effects on GDP growth per capita of Chinese cities, whereas material capital and labor input remain primary driving forces for Chinese local economic development. Furthermore, human capital contributes to accelerating urban economic development, whereas government intervention restrains urban economic development.

Analysis on Micro Creative Space Development from the Perspective of New Urbanization View Field——Taking Micro Creative Garden of Gongshu District as an Example

With the rapid developmem of new urbanization, a number of micro creative space has emerged in China. The micro creative space of Gongshu District in Hangzhou has experienced a rapid and mixed development. Considering the existing problems of those space, the following measures can help those space realize an organic urban growth： arranging the layout comprehensively, optimizing industrial agglomeration, improving the planning management quality and optimizing public platform serx, ice support. The good development of micro creative garden can promote the full flow of creative element, so as to accelerate city economic structure transformation, increase city space efficiency and promote the city innovation development.

An Efficient Approach to Narrow the Emission Band of Pyrene-Based Emitters

The construction of high color purity and high resolution organic light-emitting diodes(OLEDs)is facilitated by the development of highly-efficient organic luminescent materials with narrow-band emission.Herein,in order to address the problem of broad emission spectra of organic luminescent materials,an effective molecular design strategy is presented to reduce the full width at half maximum(FWHM)of emission by integrating the steric hindrance effect in the pyrene system.As the bulky group was introduced into the 2-position,compounds 5 not only show a relative high quantum yield(>0.31)in the solid state,but also can suppress the molecular rotation of triphenylamine(TPA)at the 3-position to narrow the FWHM in the solid state compared to that in solution.Compound 5c containing biphenyl units exhibits a maximum emission peak at 484 nm with a quantum yield of 0.38 and FWHM value of 49 nm in the solid state.

Aggregation-Induced Emission(AIE)Active Fluoroboronated Pyridylhydrazinyl Aldehyde Hydrozone Dyes:Synthesis,Crystal Structure and Optical Properties

A new family of fluoroboronated pyridylhydrazinyl aldehyde hydrozone fluorophores named BOPAHs were developed via a simple one-pot two-step reaction from chloro-2-hydrazinylpyridine and aromatic aldehyde derivatives.They were well characterized by NMR,HRMS,and X-ray crystal structures.They exhibit main absorption from 400 nm to 600 nm and emission bands from 500 nm to 700 nm.The absorption/emission bands redshift with increased polarity of solvents indicate a distinct intramolecular charge transfer characteristic,further confirmed by density functional theory(DFT)calculations.These BOPAHs display weak fluorescence in solutions,but they exhibit obvious aggregation-induced emission properties,possibly resulting from weak intermolecular interactions by fixing the molecular conformations in aggregate states.

Construction of Type I Aggregation-Induced Emission Photosensitizers for Photodynamic Therapy via Photoinduced Electron Transfer Mechanism

Photodynamic therapy(PDT)as a non-invasive anticancer modality has received increasing attention due to its advantages of noninvasiveness,high temporospatial selectivity,simple and controllable operation,etc.PDT mainly relies on the generation of toxic reactive oxygen species(ROS)by photosensitizers(PSs)under the light irradiation to cause cancer cell apoptosis and death.However,solid tumors usually exhibit an inherent hypoxic microenvironment,which greatly limits the PDT efficacy of these high oxygen-dependent conventional type II PSs.Therefore,it is of great importance to design and develop efficient type I PSs that are less oxygen-dependent for the treatment of hypoxic tumors.Herein,a new strategy for the preparation of efficient type I PSs by introducing the photoinduced electron transfer(PET)mechanism is reported.DR-NO_(2) is obtained by introducing 4-nitrobenzyl to(Z)-2-(5-(4-(diethylamino)-2-hydroxybenzylidene)-4-oxo-3-phenylthiazolidin-2-ylidene)malononitrile(DR-OH)with aggregation-induced emission(AIE)feature.The AIE feature ensures their high ROS generation efficiency in aggregate,and the PET process leads to fluorescence quenching of DR-NO_(2) to promote triplet state formation,which also promotes intramolecular charge separation and electron transfer that is conducive for type I ROS particularly superoxide radicals generation.In addition,DR-NO_(2) nanoparticles are prepared by nanoprecipitation to possess nanoscaled sizes,high cancer cell uptake,and excellent type I ROS generation ability,which results in an excellent performance in PDT ablation of MCF-7 cancer cells.This PET strategy for the development of type I PSs possesses great potential for PDT applications against hypoxic tumors.

Tetraphenylethylene-BODIPY aggregation-induced emission luminogens for near-infrared polymer light-emitting diodes

The aggregation-induced emission(AIE) phenomenon provides a new direction for the development of organic light-emitting devices. Here, we present a new class of emitters based on 4,4-difluoro-4-bora-3 a,4 a-diaza-s-indacene(BODIPY), functionalized at different positions with tetraphenylethylene(TPE), which is one of the most famous AIE luminogens. Thanks to this modification, we were able to tune the photoluminescence of the BODIPY moiety from the green to the near-infrared(NIR)spectral range and achieve PL efficiencies of ~50% in the solid state. Remarkably, we observed an enhancement of the AIE and up to ~100% photoluminescence efficiencies by blending the TPE-substituted BODIPY fluorophores with a poly[(9,9-di-noctylfluorene-2,7-diyl)-alt-(benzo[2,1,3]thiadiazol-4,7-diyl)](F8 BT) matrix. By incorporating these blends in organic lightemitting diodes(OLEDs), we obtained electroluminescence peaked in the range 650–700 nm with up to 1.8% external quantum efficiency and ~2 m W/cm2 radiance, a remarkable result for red/NIR emitting and solution-processed OLEDs.