Enhanced Visible Light Photoelectrochemical Performances with Nitrogen Doped TiO_2 Nanowire Arrays

成功制备了氮掺杂锐钛矿TiO2纳米线,并研究了它的光电化学性质.结果表明,与商用P25 TiO2纳米粒子和未掺杂TiO2纳米线相比,氮掺杂TiO2纳米线作为光阳极明显地提高了光电转换效率(IPCE%),在可见光区有明显光吸收;在100 mW/cm2可见光光照下,氮掺杂TiO2纳米线具有最大的光电流密度和能量转换效率.例如,当电压为0.09 V(vs.Ag/AgC l)时最大能量转换效率为0.52%,均高于未掺杂TiO2纳米线和商用P25 TiO2纳米粒子的,充分表现出它优越的光响应和光电化学性能,在光电化学池、太阳能制氢等方面具有广泛的应用前景.Self-organized anodic anatase TiO2nanowire arrays doped with nitrogen have been successfully fabri-cated and their photoelectrochemical(PEC) properties have been characterized and found to be substantially im-proved compared to undoped nanowires or commercial P25 nanoparticles.Photocurrent measured with monochro-matic incident light showed that the incident photon-to-current efficiency(IPCE,%) values of nanowire arrayelectrodes with or without N-doping were obviously higher than that of commercial P25 nanoparticle electrodes,and nitrogen-doped TiO2nanowire arrays(NTNA) had noticeable absorption in the visible region.The NTNAelectrodes showed the highest photocurrent density and power conversion efficiency under 100 mW/cm2visiblelight illumination.A maximumolphotoconversion efficiency of 0.52% was achieved for the NTNA sample at anapplied potential of 0.09 V versus Ag/AgCl(saturated KCl) electrode under visible illumination,much higherthan that of the undoped nanowire and commercial P25 nanoparticle electrodes.These results demonstrate thatNTNA thin films are promising for enhancing the photoresponse and effectively improving PEC performances ofnanostructured TiO2in the visible region for different applications including solar hydrogen generation.作者联系地址：清华大学化学系;美国加利福尼亚大学Santa Cruz分校化学与生物化学系;Author's Address: 1.Department ofChemistry,Tsinghua University,Beijing100084,China;2.Department ofChemistry and Biochemistry,University ofCalifornia,Santa Cruz,California95064,US

CCCCC pentadentate chelates with planar Möbius aromaticity and unique properties

本课题充分发挥了厦门大学多学科协同研究优势，通讯作者为夏海平教授（合成、表征）、刘刚教授（生物医学应用）和吕鑫教授（理论计算）。合成实验和结构表征由朱从青（第一作者，目前在麻省理工学院、2005年诺贝尔化学奖得主Richard Schrock教授课题组从事博士后研究）完成；生物医学应用由杨彩霞（共同第一作者）、林凎、杨宇惠、王晓勇合作完成；理论计算由朱军、王永恒、朱从青完成。美国NIH的陈小元教授参与了生物医学应用的讨论。该研究工作得到国家自然科学基金委、科技部项目的支持。The coordinating atoms in polydentate chelates are primarily heteroatoms. We present the first examples of pentadentate chelates with all binding atoms of the chelating agent being carbon atoms, denoted as CCCCC chelates. Having up to five metal-carbon bonds in the equatorial plane has not been previously observed in transition metal chemistry. Density functional theory calculations showed that the planar metallacycle has extended Craig-Möbius aromaticity arising from 12-center–12-electron dπ-pπ π-conjugation. These planar chelates have broad absorption in the ultraviolet-visible–near-infrared region and, thus, notable photothermal performance upon irradiation by an 808-nm laser, indicating that these chelates have potential applications in photothermal therapy. The combination of facile synthesis, high stability, and broad absorption of these complexes could make the polydentate carbon chain a novel building block in coordination chemistry.the National Basic Research Program of China (nos. 2012CB821600 and 2014CB744503) , the National Science Foundation of China (nos. 21332002, 81422023, 51273165, 21490573, and 21573179)

Stabilization of anti-aromatic and strained five-membered rings with a transition metal

1981年诺贝尔化学奖获得者、美国康奈尔大学RoaldHoffmann教授评价该项工作说：'The　paper is an excellent one--it's　quite a mazing that the parent Os　system,molecule 1,chooses to give the osmapentalyne'。德国化学家Uwe Rosenthal教授等在同期《自然—化学》杂志的《News and Views》栏目以《Breaking the rules》为题撰文评述了这一研究成果。全文地址：http://www.nature.com/nchem/journal/vaop/ncurrent/pdf/nchem.1702.pdfAnti-aromatic compounds, as well as small cyclic alkynes or carbynes, are particularly challenging synthetic goals. The combination of their destabilizing features hinders attempts to prepare molecules such as pentalyne, an 8π-electron anti-aromatic bicycle with extremely high ring strain. Here we describe the facile synthesis of osmapentalyne derivatives that are thermally viable, despite containing the smallest angles observed so far at a carbyne carbon. The compounds are characterized using X-ray crystallography, and their computed energies and magnetic properties reveal aromatic character. Hence, the incorporation of the osmium centre not only reduces the ring strain of the parent pentalyne, but also converts its Hückel anti-aromaticity into Craig-type Möbius aromaticity in the metallapentalynes. The concept of aromaticity is thus extended to five-membered rings containing a metal–carbon triple bond. Moreover, these metal–aromatic compounds exhibit unusual optical effects such as near-infrared photoluminescence with particularly large Stokes shifts, long lifetimes and aggregation enhancement

Design a chemically defined/medically approved medium for microencapsulated cells

Design a chemically defined/medically approved medium for microencapsulated cells Purpose of study: Implantation of microencapsulation of recombinant cells has great potential for gene therapy where therapeutic protein can be sustained and long-term delivered by microencapsulated cells [1]. However, once cells are encapsulated in microcapsules, they need to be cultured or preserved in serum free medium or chemical defined additives that are medically approved to maintain the cell viability before implantation. Based on the metabolic characteristics of microencapsulated cells, the purpose of this study is to develop a simple, low protein, microcapsules suited and medically approved chemically defined medium for microencapsulated cell culture. Methods: Firstly, the metabolic characteristics of amino acid were assayed for non-encapsulated cells and encapsulated cells. According to this result, the optimum amino acid supplements were adjusted to the base medium. Secondly, orthogonal test design was applied to select a suitable chemically defined medium for microencapsulated cells. Finally, the effects of the optimized medium on the microencapsulated cells viability, therapeutic protein production and long-term in vitro stability of APA microcapsules were evaluated. Results and Conclusions: The results show that the optimized medium significantly enhances cell survival and, particularly, endostatin secretion of encapsulated CHO cells over a time period of 8 weeks. Furthermore, long-term in vitro stability of Alginate-poly-lysine-alginate (APA) microcapsules underwent no changes, which indicated that this optimized medium might be feasible to maintain high viability of microencapsulated cell for short periods of time before implantation

一种胰蛋白酶抑制剂及其应用

本发明涉及一种胰蛋白酶抑制剂，其特征在于所述的胰蛋白酶抑制剂主要成分为海藻酸盐或其衍生物；与传统胰蛋白酶抑制剂相比，本发明优势在于抑酶效率高，成本低，原料丰富，制备简单，无毒副作用，生物稳定性好，更适合作为蛋白质与多肽类药物制剂中的抗酶解辅料

一种脂质载体与难溶性药物组合物及其制备方法

本发明提供一种脂质载体与难溶性药物组合物及其制备方法，该组合物包括两种：自微乳难溶性药物组合物和固体脂质纳米粒载体与难溶性药物组合物。所述自微乳难溶性药物组合物由难溶性药物0.05-10wt%，液态脂质5-60wt%,表面活性剂20-50wt%，助表面活性剂10-35wt%组成；所述固体脂质纳米粒载体与难溶性药物组合物由难溶性药物0.05-5wt%,固态脂质40-69wt%，表面活性剂30-59wt%组成。上述脂质载体与难溶性药物组合物通过改变脂质的种类和比例可以控制脂肪酶对其水解程度在3-90%之间。由于难溶性药物在脂质载体中的释放速率与脂质载体的水解相关，进而通过控制脂质载体的水解速率实现改变难溶性药物药代动力学的目的

微囊化重组CHO细胞制备和培养条件的优化

微囊化重组基因细胞移植治疗肿瘤是一种新兴的肿瘤基因治疗方法,然而由于目前微囊化细胞规模化制备和培养技术还不成熟,阻碍了其在临床治疗中的推广与应用。以重组CHO细胞为模型,考察了不同的微囊制备和培养条件对微囊化细胞生长和内皮抑素表达的影响。实验表明,种子细胞所处的生长阶段和细胞接种密度对微囊化细胞生长和内皮抑素表达的影响较大,对数生长期的细胞进行包囊并且细胞接种密度为1×106~2×106cells/mL微囊时微囊内细胞生长良好、内皮抑素表达量高。微囊制备时间对细胞活性和内皮抑素表达也有较大的影响,制备时间延长对细胞的损伤增大,因此制备时间应控制在5h以内。生物微胶囊在制备过程中会造成细胞损伤,而体外培养是恢复细胞活性的良好方法,在培养过程中微囊接种量为5%时对细胞生长和内皮抑素表达有利