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Oligo(ethylene glycol)-terminated monolayers on silicon surfaces and their nanopatterning with a conductive atomic force microscope

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Science China chemistry 2010年第1期53卷 36-44页

作者： QIN GuoTing & CAI ChengZhi department of chemistry,university of Houston,Houston,texas 77204,usa 1. department of chemistry University of Houston Houston Texas 77204 USA

Functionalization of silicon substrate surfaces with a stable monolayer for resisting non-specific adsorption of proteins has attracted great interest,since it is directly relevant to the development of miniature,silicon-based biosensors and implantable microdevices,such as silicon-neuron *** brief review summarizes our contribution to the development of robust monolayers grown by surface hydrosilylation on atomically flat,hydrogen-terminated silicon *** review also outlines our strategy and progress on the fabrication of single molecule patterns on such monolayer platforms.

关键词： protein-resistant monolayers surface hydrosilylation conductive atomic force microscope nanopatterning

The Synthesis of a New Macrocyclic Dinucleating Ligand,3,6,9,17,20,23-Hexaaza-29,30-Dihydroxy-13,27-Dimethyl-Tricyclo[23,3,1,1^(11,15)]Triaconta-1(28),11,13, 15(30),25,26-Hexaene

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Chinese Chemical Letters 2000年第7期11卷 573-576页

作者： Guo Qiang SHANGGUAN Arthur E. MARTELL Zhong Ren ZHANG (department of chemistry, Jining Medical College, Jining 272013department of chemistry, texas A&M university, College Station, texas 77842 usa) Jining Med Coll Dept Chem Jining 272013 Peoples R China texas A&M Univ Dept Chem College Stn TX 77842 USA

A new dinucleating 24-membered hexaazadiphenol macrocyclic ligand, 3,6,9,17,20, 23-hexaaza-29,30- dihydroxy-13,27-dimethyl-tricycl [23, 3, 1, 1 11,15] triaconta -1(28), 11,13,15(30),25, 26-hexaene, BDBPH, was synthesized by the NaBH4 reduction of the Schiff-base obtained from the [2+2] condensation between diethylenetriamine and diformyl -p-cresol. The structure was characterized by elemental analysis, 1HNMR and FAB-MS. The synthetic method was also discussed.

关键词： Macrocyclic ligand synthesis

The Crystal and Molecular Structure of a New Macrocyclic Ligand, (H_6BDBPH)Br_6·4H_2O

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Chinese Journal of Structural chemistry 2000年第5期19卷 334-337页

作者： SHANGGUAN Guo\|Qiang (department of chemistry, Jining Medical College, Jining 272013) [WT4”BZ]Arthur E. Martell Zhongren Zhang Joseph Reibenspies (department of chemistry, texas A&M university, College Station, texas 77842, usa) department of chemistry Jining Medical College Jining 272013 China department of chemistry Texas A and M University College Station TX 77842 United States

The hexahydro\|bromide salt of a new 24\|membered hexaaza diphenol macrocyclic ligand, （H6BDBPH）Br6·4H2O （C 26H 56N6O6Br6, Mr= 1028.23）, crystallizes in the monoclinic system, space group P21/c, with cell parameters: a=14.441（5）, b=11.482（4）, c=12.090（6）, β=96.92°, V= 1990 （1）3, Z=2, Dc=1.716 g/cm3; F（000） =1024. MoKα radiation, λ= 0.71013), R = 0.0643 and wR = 0.1356 for 3507 independent reflections with I>2σ（I）. The macrocyclic ligand adapts chair form, and the crystallographic inversion center is located in the macrocyclic cavity, and the six bromide ions and four water molecules are situated symmetrically outside the macrocyclic cavity.

关键词： macrocyclic ligand synthesis crystal structure

The combination of benzamides/NCS as nitrogen/halogen sources for aminohalogenation of β-nitrostyrenes resulting in dichlorinated haloamides

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Science China chemistry 2010年第9期53卷 1946-1952页

作者： ZHI SanJun1,2,MEI HaiBo1,ZHANG GuangQian1,SUN Hao1,HAN JianLin1,LI GuiGen4 & PAN Yi1,3 1 School of chemistry and Chemical Engineering,Nanjing university,Nanjing 210093,China 2 School of chemistry and Chemical Engineering,Huaiyin Normal university,Huai’an 221003,China 3 State Key Laboratory of Coordination chemistry,Nanjing university,Nanjing 210093,China 4.department of chemistry and biochemistry,texas tech university,texas 794.9-1061,usa 1. School of chemistry and Chemical Engineering Nanjing University Nanjing 210093 China2. School of Chemistry and Chemical Engineering Huaiyin Normal University Huai’an 221003 China4. Department of Chemistry and Biochemistry Texas Tech University Texas 79409-1061 USA3. State Key Laboratory of Coordination Chemistry Nanjing University Nanjing 210093 China

The combination of benzamide and NCS was found to be an efficient nitrogen/halogen source for aminohalogenation of β-*** reaction was convenient to carry out by using 4-dimethylaminopyridine as the catalyst,resulting in vicinal dichlorinated haloamino nitroalkanes with opposite regiochemistry to that generated from other electron-deficient olefins observed *** reaction proceeded smoothly at room temperature with good yields and excellent regioselectivities.A mechanism involving a chloronium intermediate was proposed to explain the resulting *** current system explored a new type of nitrogen sources for aminohalogenation of functionalized olefins.

关键词： aminohalogenation benzamide β-nitrostyrenes DMAP haloamides

Total synthesis of(+)-lentiginosine via a key Au catalysis

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Science China chemistry 2010年第1期53卷 113-118页

作者： CUI Li & ZHANG LiMing department of chemistry & biochemistry,university of California,Santa Barbara,CA 93106,usa 1. department of chemistry & biochemistry University of California Santa Barbara CA 93106 USA

Total syntheses of(+)-lentiginosine and its 8a-epimer using a gold-catalyzed oxidative cyclization as the key step were *** gold chemistry,reported previously in a 4+2 synthesis of piperidin-4-ones,tolerates functiona... 详细信息

关键词： gold total synthesis cyclization oxidation alkaloid

Adaptive Control of Lower-Limb Exoskeletons for Walking Assistance Based on Inter-Joint Coordination

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Journal of Bionic Engineering 2024年第4期21卷 1775-1787页

作者： Chaoyang Li Lincong Luo Zhi Liu Tianchi Chen Songxiang Liu Ye He Xiaoan Chen Lei Li Wei tech Ang School of Mechanical Engineering Chongqing UniversityChongqing400044China Rehabilitation Research Institute of Singapore Singapore308232Singapore department of Orthopedics Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China School of Mechanical and Aerospace Engineering Nanyang Technological UniversitySingapore639798Singapore

Unilateral motor impairment can disrupt the coordination between the joints,impeding the patient’s normal *** assist such patients to walk normally and naturally,an adaptive control algorithm based on inter-joint coordination was proposed in this work for lower-limb *** control strategy can generate the reference trajectory of the affected leg in real time based on a motion coordination model between the joints,and adopt an adaptive controller with virtual windows to track the reference *** Short-Term Memory(LSTM)network was also adopted to establish the coordination model between the joints of both lower limbs,which was optimized by preprocessing angle information and adding gait phase *** the adaptive controller,the virtual windows were symmetrically distributed around the reference trajectory,and its width was adjusted according to the gait phase of the auxiliary *** addition,the impedance parameters of the controller were updated online to match the motion capacity of the affected leg based on the spatiotemporal symmetry factors between the bilateral *** LSTM coordination model demonstrated good accuracy and generality in the gait database of seven individuals,with an average root mean square error of 3.5 and 4.1 for the hip and knee joint angle estimation,*** further evaluate the control algorithm,four healthy subjects walked wearing the exoskeleton while additional weights were added around the ankle joint to simulate an asymmetric *** the experimental results,it was shown that the algorithm improved the gait symmetry of the subjects to a normal level while exhibiting great adaptability to different subjects.

关键词： Lower-limb exoskeleton Adaptive control Gait symmetry Inter-joint coordination Motion estimation

Mitral valve mechanics and function

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医用生物力学 2010年第S1期25卷 47-48页

作者： Zhaoming He(department of Mechanical Engineering texas tech university,lubbock,TX 794.9,usa)

Introduction Progress in valve repair techniques is improving the quality of life of patients with mitral valve regurgitation and make valve repair preferred over valve replacement. However,the major hurdle of valve r... 详细信息

关键词： length

Complex role of matrix metalloproteinases in angiogenesis

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Cell Research 1998年第3期8卷 171-177页

作者： SANG QING XIANG AMY(biochemistry Division, department of chemistry, Florida State university, Tallahassee, Florida 32306-4390, usa) biochemistry Division Department of Chemistry Florida State University Tallahassee USA

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMP) play a significant role in regulating angiogenesis, the process of new blood vessel formation. Interstitial collagenase (MMP-1), 72 kDa gelatinase A/type IV collagenase (MMP-2), and 92 kDa gelatinase B/type IV collagenase (MMP-9) dissolve extracellular matrix (ECM) and may initiate and Promote angiogenesis. TIMP-1, TIMP-2, TIMP-3, and possibly,TIMP-4 inhibit neovascularisation. A new paradigm is emerging that matrilysin (MMP-7), MMP-9, and metalloelastase (MMP-12) may block angiogehesis by converting plasndnogen to angiostatin, which is one of the most potent angiogenesis antagonists. MMPs and TIMPs play a complex role in regulating angiogenesis. An understanding of the biochemical and cellular pathways and mechanisms of angiogenesis will provide importal information to allow the control of angiogenesis, e.g. the stimulation of angiogenesis for coronary collateral circulation formation; while the inhibition for treating arthritis and cancer.

关键词： Collagenases tissue inhibitors of metalloproteinases neovascularization plasminogen angiostatin converting enzymes extracellular matrix

Levels of toxic metal in Achatina achatina from parts of Akwa Ibom State, Nigeria

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Journal of Environmental Sciences 2000年第1期12卷 70-76页

作者： Essien D. Udosen (department of chemistry and biochemistry, university of Uyo,Nigeria) university of Uyo 尼日利亚

Tropical land snail (Achatina achatina) were collected from three areas *** Ibom Local Government Area (NTB), Nsit Ubium Local Government Area (NTU) and Uyo Municipality (UYM), all in Akwa Ibom State to determine the levels of Ni, Pb, Zn and Cr in their shells and muscles. Generally, the levels of all the metals in the muscles were comparatively higher than that in the shells. Correspondingly, the metals appear to have been more stable in the muscles with comparatively lower coefficients of variation than in the shells. Moreover while there was no significant correlation between the levels of all the metals in shells and muscles of NTU samples, Pb and Zn in NTB correlated very significantly. The correlation between levels of Cr in NTB samples and of Zn in UYM samples in shells and muscles were equally significant. On the whole, the levels of these metals were found to be much lower in both shells and muscles of NTU samples obtained from the “enclosed and restricted” environment than in NTB and UYM samples collected randomly from “open and unrestricted” environments.

关键词： levels of toxic Achatina achatina Nigeria CLC number: X75 Document code: A