长江经济带人口-耕地-粮食复合系统协调性时空演变

运用耦合协调度模型,对长江经济带人口、耕地和粮食三者间的关系进行了研究。研究表明:(1)长江经济带的整体耦合协调度不高。2003年耦合协调度最低,之后快速上升,2013年达到勉强协调类型;(2)长江经济带各地区三者的协调性存在显著的时间差异。长江经济带各省市的人口-耕地-粮食的协调性随着时间而逐步演变;(3)长江经济带各地区三者的协调性存在显著的空间差异。各省市当年的协调类型呈现着显著的空间分布特征,长江经济带较高协调性的地区呈现西移的趋势。基于研究结论,为促进长江经济带人口、耕地和粮食三者的协调发展,提出加强耕地保护、推动农业集约化以及加强长江经济带的区域合作等政策建议。更多还原     

Iodine-catalyzed coupling of β-hydroxyketones with aromatic amines to form β-aminoketones and Benzo[h]quinolones

An iodine-catalyzed coupling of β-hydroxyketones with aromatic amines to yield β-aminoketones and benzo[h]quinolones had been developed. Noble metallic catalysts, oxidants, α, β-unsaturated ketone intermediates and aza-Michael addition were not involved in this coupling reaction which made it unique when compared to other reactions reported in literature. Inexpensive iodine catalyst, easy accessible raw materials, mild reaction conditions, good functional group tolerance and excellent selectivity made this coupling reaction be a practical method. This reaction can also be scaled up.     

In Vitro Fabrication and Biocompatibility Assay of a Biomimetic Osteoblastic Niche

Applied Biochemistry and Biotechnology - A novel HAp-CS/Gel biomimetic osteoblastic niche was fabricated by freeze-drying, and its mechanical strength and biocompatibility were characterized....     

Bifunctional Catalysts Containing Zn(II) and Imidazolium Salt Ionic Liquids for Chemical Fixation of Carbon Dioxide

Zn(II) can efficiently promote the catalytic performance of imidazolium salt ionic liquids (imi-ILs) for the chemical fixation of CO₂ into epoxides. To obtain sustainability, immobilized bifunctional catalysts containing both imi-ILs and Zn(II) were prepared using bimodal mesoporous silica (BMMs) as carrier, through grafting of Zn(OAc)₂ and 1-(trimethoxysilyl)propyl-3-methylimidazolium chloride (Si-imi) separately in the nanopores. The catalysts, named as BMMs−Zn&ILs, were identified as efficient catalysts for cycloaddition reaction of CO₂ into epoxides under solvent-free conditions. BMMs−Zn&ILs showed good catalytic activity, which increased with the increase of the molar ratio of Zn(II) to Si-imi. As a comparison, different catalytic systems including homogeneous imi-IL, BMMs-ILs and BMMs−Zn were studied to demonstrate different cooperation behaviors. Furthermore, the kinetics studies of homogeneous and heterogeneous bifunctional catalysts were employed to confirm the differences, as well as to support the proposed cooperative catalysis mechanism in the nanopores.     

随机光学重构超高分辨显微镜的使用研究与共享管理

随机光学重构超高分辨成像技术(STORM)采用基于光控荧光分子的单分子定位算法,横向和轴向分辨率分别达到~20 nm和~50 nm。本文结合使用和管理经验,对超高分辨STORM显微镜的原理、软硬件组成和技术参数、样品制备方法、超高分辨图像采集的常用操作流程、环境要求、日常维护、共享平台管理、STORM显微镜的应用等方面加以介绍,并对进一步提高STORM时空分辨率进行展望。     

Effects of Compound Elicitors on the Biosynthesis of Triterpenoids and Activity of Defense Enzymes from Inonotus hispidus (Basidiomycetes)

Inonotus hispidus has various health-promoting activities, such as anticancer effects and immune-stimulating activity. The commercialization of valuable plant triterpenoids faces major challenges, including low abundance in natural hosts and costly downstream purification procedures. In this work, orthogonal design was used to compound methyl jasmonate (MeJA), salicylic acid (SA), oleic acid, and Cu²⁺, and the effects of combinations on the total triterpenes biosynthesized were studied. The optimal combination was screened out and its effect on the activity of PAL, CAT, and SOD was studied. The optimal concentration of oleic acid was 2% when MeJA was 100 mol/L, and the total triterpenoid content and mycelia production were 3.918 g and 85.17 mg/g, respectively. MeJA treatment induced oxidative stress, and at the same time increased the activity of related defense enzymes. Oleic acid is thought to regulate cell permeability by recombining cell membranes. It promotes the material exchange process between cells and the environment without affecting cell growth. When oleic acid was used in combination with MeJA, a synergistic effect on triterpene production was observed. In conclusion, our findings provide a strategy for triterpenoid enrichment of I. hispidus.     

Spectrometric study of the interaction between Alpinetin and bovine serum albumin using chemometrics approaches

The binding interaction of Alpinetin (APT) with bovine serum albumin (BSA) was studied by fluorescence, UV-visible and synchronous fluorescence spectroscopy (SFS) under simulated physiological conditions. The measured complex spectra were resolved by multivariate curve resolution-alternating least squares (MCR-ALS), yielding a host of data and information, which otherwise would have been impossible to obtain. The extracted profiles corresponded to the spectra of the single species in the APT/BSA mixture. In addition, the presence of the APT-BSA complex was demonstrated, and it was shown that the associated quenching of the fluorescence from the BSA protein resulted from the formation of APT-BSA complex via a static mechanism. The binding constant (K_a(ave) = 2.34 × 10⁶ L mol⁻¹) and the number of sites (n = 1) were obtained by fluorescence methods as were the thermodynamic parameters (ΔH⁰, ΔS⁰ and ΔG⁰). This work suggested that the principal binding between APT to BSA was facilitated by hydrophobic interactions. The thermodynamic parameters for APT were compared to those from the structurally similar Chrysin and Wogonin molecules. It appeared that the entropy parameters were relatively more affected by the small structural changes. SFS from the interaction of BSA and APT showed that the ligand affected the conformation of BSA. The competitive interaction of APT and site makers with BSA indicated site I as the binding area of APT in BSA.     

Synthesis,crystal structures,and antitumor activity of three new organotin carboxylates

Three new organotin(IV) carboxylates of composition [(R)₂Sn(O₂CC₆H₄C‐OC₆H₄CH₃)₂] 1 , [(R)₂Sn(O₂CC₆H₄COC₆H₄‐C₂H₅)₂]₂ 2 , and R₃SnO₂ CC₆H₄COC₆H₄CH₃ 3 , were obtained by reactions of (R)₂SnO [R = o‐tolyl] with 2‐(4‐methyl benzoyl) benzoic acid and 2‐(4‐ethyl benzoyl) benzoic acid, and reaction of Cy₃SnOH [Cy = cyclohexyl] with 2‐(4‐methyl benzoyl) benzoic acid, respectively. The complexes 1 , 2 and 3 have been characterized by elemental analysis, infrared (IR), ¹HNMR, and X‐ray crystallography diffraction analyses. The complex 1 has two folded symmetrical structure; the tin atom in 1 is found to adopt a distorted toward skew‐trapezoidal bipyramidal geometry. Molecular structure of the complex 2 is centrosymmetric, and the internal tin atom is five‐coordinated and is in distorted trigonal bipyramidal geometry. The crystal structure of the complex 3 is found to exhibit distorted tetrahedral geometry. Pilot studies have indicated that the complexes 1 and 2 have shown good antitumor activities. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:304–313, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20614     

Polyol Solvation Effect on Tuning the Universal Growth of Binary Metal Oxide Nanodots@Graphene Oxide Heterostructures for Electrochemical Applications

Tuning the uniformity and size of binary metal oxide nanodots on graphene oxide (BMO NDs@GO) is significant but full of challenges in wet-chemistry, owing to the difficulties of controlling the complicated cation/anion co-adsorption, heterogeneous nucleation, and overgrowth processes. Herein, the aim is to tune these processes by understanding the functions of various alcohol solvents for NDs growth on GO. It is found that the polyol solvation effect is beneficial for obtaining highly uniform BMO NDs@GO. Polyol shell capped metal ions exhibit stronger hydrogen-bond interactions with the GO surface, leading to a uniform cation/anion co-adsorption and followed heterogeneous nucleation. The polyol-solvated ions with large diffusion energy barrier drastically limit the ion diffusion kinetics in liquids and at the solid/liquid interface, resulting in a slow and controllable growth. Moreover, the synthesis in polyol systems is highly controllable and universal, thus eleven BMO and polynary metal oxide NDs@GO are obtained by this method. The synthetic strategy provides improved prospects for the manufacture of inorganic NDs and their expanding electrochemical applications.     

Facile one‐pot/one‐step technique for preparation of side‐chain functionalized polymers: Combination of SET‐RAFT polymerization of azide vinyl monomer and click chemistry

An azido‐containing functional monomer, 11‐azido‐undecanoyl methacrylate, was successfully polymerized via ambient temperature single electron transfer initiation and propagation through the reversible addition–fragmentation chain transfer (SET‐RAFT) method. The polymerization behavior possessed the characteristics of “living”/controlled radical polymerization. The kinetic plot was first order, and the molecular weight of the polymer increased linearly with the monomer conversion while keeping the relatively narrow molecular weight distribution (M_w/M_n ≤ 1.22). The complete retention of azido group of the resulting polymer was confirmed by ¹H NMR and FTIR analysis. Retention of chain functionality was confirmed by chain extension with methyl methacrylate to yield a diblock copolymer. Furthermore, the side‐chain functionalized polymer could be prepared by one‐pot/one‐step technique, which is combination of SET‐RAFT and “click chemistry” methods. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012