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Orthorhombic crystal structure of an insulin mutant B9Asp at 0.20 nm resolution

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Progress in Natural Science:Materials International 2000年第6期 42-47页

作者：刘新奇,金雷,张英,jan Markussen,王大成 Institute of Biophysics Chinese Academy of Sciences Beijing 100101 China Institute of Biophysics Chinese Academy of Sciences Beijing 100101 China Institute of Biophysics Chinese Academy of Sciences Beijing 100101 China Novo Reaserch Institute Novo Alle Denmark. Institute of Biophysics Chinese Academy of Sciences Beijing 100101 China

Human B9(Ser→Asp) insulin, a fast-absorption insulin analogue, was obtained by site-directed mutagenesis at B9 position. The orthorhombic crystal structure of B9Asp insulin was analyzed by crystallography at 0.20 nm resolution. Although no significant change of its overall conformation was observed, the local conformation flanking B9 site differed greatly from native T6 human insulin. The substitution of serine at B9 position by aspartic acid resulted in obvious alteration of local hydrophobic and hydrophilic interactions. As a result, the insulin dimer became unstable and the capability of the hexamer formation was diminished extensively. All these properties contribute to the fast-absorption of B9Asp. In addition, the open state of N-terminus of B-chain, which differs from T- or R- state, might suggest a new conformational state in the monomer or dimer insulin.

关键词： crystal structure insulin mutant fast-absorption B9Asp analogue.

Nanoscopic Tip Sensors Fabricated by Gas Phase Etching of Optical Glass Fibers

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Photonic Sensors 2012年第4期2卷 331-339页

作者： Jorg BIERLICH Jens KOBELKE David BRAND Konstantin KIRSCH jan DELLITH Hartmut BARTELT IPHT Institute of Photonic Technology Albert-Einstein-Sir. 9 07745 Jena Germany EAH University of Applied Sciences Carl-Zeiss-Promenade 2 07745 Jena Germany

Silica-based fiber tips are used in a variety of spectroscopic, micro- or nano-scopic optical sensor applications and photonic micro-devices. The miniaturization of optical sensor systems and the technical implementation using optical fibers can provide new sensor designs with improved properties and functionality for new applications. The selective-etching of specifically doped silica fibers is a promising method in order to form complex photonic micro structures at the end or within fibers such as tips and cavities in various shapes useful for the all-fiber sensor and imaging applications. In the present study, we investigated the preparation of geometrically predefined, nanoscaled fiber tips by taking advantage of the dopant concentration profiles of highly doped step-index fibers. For this purpose, a gas phase etching process using hydrofluoric acid （HF） vapor was applied. The shaping of the fiber tips was based on very different etching rates as a result of the doping characteristics of specific optical fibers. Technological studies on the influence of the etching gas atmosphere on the temporal tip shaping and the final geometry were performed using undoped and doped silica fibers. The influence of the doping characteristics was investigated in phosphorus-, germanium-, fluorine- and boron-doped glass fibers. Narrow exposed as well as protected internal fiber tips in various shapes and tip radiuses down to less than 15 nm were achieved and characterized geometrically and topologically. For investigations into surface plasmon resonance effects, the fiber tips were coated with nanometer-sized silver layers by means of vapour deposition and finally subjected to an annealing treatment.

关键词： Optical fiber tips nanoprobes gas phase etching doping tip shaping metal coating

Sensitive Spectrofluorimetric Method for Determination of Fluoroquinolones through Charge-Transfer Complex Formation

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American Journal of Analytical Chemistry 2013年第10期4卷 521-530页

作者： Jasmin Shah M. Rasul jan Inayat Ullah Sultan Shah Institute of Chemical Sciences University of Peshawar Peshawar Pakistan

A sensitive spectrofluorimetric method was developed for determination of ciprofloxacin (CPFX), levofloxacin (LEV), gatifloxacin (GAT) and moxifloxacin (MOX) in pure, commercial formulations, human urine and plasma. The method is based on charge-transfer (CT) complex with chloranilic acid. Fluorescence intensity of the complexes was measured at emission wavelength ranging from 445-492 nm with excitation wavelengths from 285-330 nm. At optimum experimental conditions, a linear calibration plot was obtained in the concentration range of 20-1000 ng·mL-1, 60-320 ng·mL-1, 20-800 ng·mL-1 and 20 -00 ng·mL-1 for CPFX, LEV, MOX and GAT, respectively with good correlation coefficient in the range of 0.9929-1.0 in methanolic medium. The limit of detection and limit of quantification were found to be 5 ng·mL-1 and 18 ng·mL-1 for CPFX, 12 ng·mL-1 and 40 ng·mL-1 for LEV, 8 ng·mL-1 and 19 ng·mL-1 for MOX, 6 ng·mL-1 and 19 ng·mL-1 for GAT, respectively. The method was found free of interferences from excipients used as additive in pharmaceutical preparations, some common cations and compounds present in urine and plasma as well as co-administered analgesic, vitamins and other drugs. The method was successfully applied for quantification of selected fluoroquinolones in commercial formulations and also in spiked human urine and plasma samples with percent recoveries of 100.0 ± 1.56 and 100.2 ± 1.29 respectively.

关键词： Fluoroquinolones Chloranilic Acid Charge-Transfer Complex Spectrofluorimetry Pharmaceutical Formulations Biological Samples

Quantitative Determination of Fluoxetine in Pharmaceuticals and Plasma Samples Using Bromatometric Method

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American Journal of Analytical Chemistry 2012年第12期3卷 828-835页

作者： Jasmin Shah Muhammad Rasul jan Muhammad Naeem Khan Sadaf Durrani Institute of Chemical Sciences University of Peshawar Peshawar Pakistan

Asensitive and simple spectrophotometric method has been developed for quantitative determination of fluoxetine using bromatometric method. The method is based on the addition of measured excess amount of bromate-bromide mixture to fluoxetine in hydrochloric acid medium. The residual bromine was determined by reacting with a fixed amount ofmethyl orange and absorbance was measured at 505 nm. The amount of bromine reacted corresponds to the amount of fluoxetine. Linear relationship between absorbance and fluoxetine concentration was found and Beer’s law was obeyed in the concentration range of 0.4 - 12 μg·mL–1. The molar absorptivity was found to be 3.8 × 104 L·mol–1·cm–1. The limit of detection and limit of quantification was calculated and found to be 0.32 μg·mL–1 and 1.0 μg·mL–1respectively. The common excipients were investigated for their interferences effect in the assay. The validity of the developed method was checked through recoveries studies and successfully applied to the determination of fluoxetine in bulk powder, pharmaceutical formulations and spiked human plasma samples. The percent recoveries were found to be in the range of 97.0% - 101.0% for pharmaceutical formulations and from 97.0% - 99.0% for spiked human plasma.

关键词： Fluoxetine Bromatometric Method Methyl Orange Spectrophotometry

Chiral Resolution,Further Modification and Biological Evaluation of CH（OH）-DAPYs as Potent HIV-1 NNRTIs

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Chiral Resolution,Further Modification and Biological Evalua...

Observing charge separation in nanoantennas via ultrafast point-projection electron microscopy

2011年全国药物化学学术会议——药物的源头创新

作者： Erik De Clercq jan Balzarini Christophe Pannecouque Rega Institute for Medical Research Katholieke Universiteit Leuven10 Minderbroedersstraat3000 Leuven Belgium

＜正＞The CH（OH）-DAPY analogues（R）-（+）-9a and（S）-（-）-9a were prepared from racemate 9a by the chiral technique of supercritical fluid chromatography（SCF） with ee%＞99%and purity＞99%,and assigned unequivocally for their absolute configuration by experimental ECD spectrum and simulated ECD spectra calculated by time-dependent density functional theory （TDDFT）.（R）-（+）-9a dispalyed the high potency with an EC50 of 5.3 nm against WT HIV-1,which was 12.3-fold more potent that（S）-（-）-***,（S）-（-）-9a showed more potency than （R）-（+）-9a against double HIV-1 RT mutant（K103N+Y181C） as well as HIV-2（strain ROD）.On the other hand,the wingⅡ（pheny） of CH（OH）-DAPYs was replaced with naphthyl to get Naph-CH（OH）-DAPYs（10a-d） with an improved activity,which might be explained by the enhancedπ-πinteractions between the inhibitors with aromatic amino acid residues Tyr188,Tyr181 and Trp229 within *** modeling results for（R）-（+）-9a and（S）-（-）-9a were also discussed.

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Light(Science & Applications) 2018年第1期7卷 532-539页

作者： jan Vogelsang Germann Hergert Dong Wang Petra Groß Christoph Lienau Carl von Ossietzky Universität Institut für Physik and Center of Interface Science26129 OldenburgNiedersachsenGermany TU Ilmenau Institut für Werkstofftechnik und Institut für Mikro-und Nanotechnologien98693 IlmenauThüringenGermany Carl von Ossietzky Universität Forschungszentrum Neurosensorik26129 OldenburgNiedersachsenGermany Department of Physics Lund UniversityBox 11822100 LundSweden

Observing the motion of electrons on their natural nanometer length and femtosecond time scales is a fundamental goal of and an open challenge for contemporary ultrafast science1–*** present,optical techniques and electron microscopy mostly provide either ultrahigh temporal or spatial resolution,and microscopy techniques with combined space-time resolution require further development6–*** this study,we create an ultrafast electron source via plasmon nanofocusing on a sharp gold taper and implement this source in an ultrafast point-projection electron *** source is used in an optical pump—electron probe experiment to study ultrafast photoemissions from a nanometer-sized plasmonic antenna12–*** probe the real space motion of the photoemitted electrons with a 20-nm spatial resolution and a 25-fs time resolution and reveal the deflection of probe electrons by residual holes in the *** is a step toward time-resolved microscopy of electronic motion in nanostructures.

关键词： projection separation sized

紫外分光光度法测定PAN纤维中的DMSO含量(英文)

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合成纤维工业 2006年第3期29卷 40-41页

作者：曾小梅 jan Ellinger 张幼维赵炯心潘鼎东华大学纤维材料改性国家重点实验室上海200051

用蒸馏水为萃取剂萃取出聚丙烯腈纤维中的DMSO,然后用紫外分光光度法测定其含量。测定的最佳线性浓度为:4．5× 10-10～1．6×10-9mol／L,DMSO最大吸收波长为208 nm, 检测限为1．9×10-9 mol/L,相关系数为0．999 8,相对标准偏差小于0．5... 详细信息

用蒸馏水为萃取剂萃取出聚丙烯腈纤维中的DMSO,然后用紫外分光光度法测定其含量。测定的最佳线性浓度为:4．5× 10-10～1．6×10-9mol／L,DMSO最大吸收波长为208 nm, 检测限为1．9×10-9 mol/L,相关系数为0．999 8,相对标准偏差小于0．5％;与其它常用的测定方法相比,解决了从纤维中分离DMSO的难题,具有简便、快速、准确和低成本的特点。

关键词：聚丙烯腈纤维紫外分光光度法二甲基亚砜测试

Novel mutations in PDE6A and CDHR1 cause retinitis pigmentosa in Pakistani families

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International Journal of Ophthalmology(English edition) 2021年第12期14卷 1843-1851页

作者： Muhammad Dawood Siying Lin Taj Ud Din Irfan Ullah Shah Niamat Khan Abid jan Muhammad Marwan Komal Sultan Maha Nowshid Raheel Tahir Asif Naveed Ahmed Muhammad Yasin Emma LBaple Andrew HCrosby Shamim Saleha Department of Biotechnology and Genetic Engineering Kohat University of Science and Technology(KUST)Kohat 26000Khyber PakhtunkhwaPakistan Medical Research RILD Wellcome Wolfson Centre(Level 4)Royal Devon and Exeter NHS Foundation TrustExeterDevon EX25DWUK Department of Ophthalmology KMU Institute of Medical Sciences(KIMS)Kohat 26000Khyber PakhtunkhwaPakistan

AIM:To investigate the genetic basis of autosomal recessive retinitis pigmentosa(arRP)in two consanguineous/endogamous Pakistani ***:Whole exome sequencing(WES)was performed on genomic DNA samples of patients with arRP to identify disease causing *** sequencing was performed to confirm familial segregation of identified mutations,and potential pathogenicity was determined by predictions of the mutations’***:A novel homozygous frameshift mutation[nm_000440.2:c.1054delG,p.(Gln352Argfs*4);Chr5:g.149286886del(GRCh37)]in the PDE6A gene in an endogamous family and a novel homozygous splice site mutation[nm_033100.3:c.1168-1G>A,Chr10:g.85968484G>A(GRCh37)]in the CDHR1 gene in a consanguineous family were *** PDE6A variant p.(Gln352Argfs*4)was predicted to be deleterious or pathogenic,whilst the CDHR1 variant c.1168-1G>A was predicted to result in potential alteration of ***:This study expands the spectrum of genetic variants for arRP in Pakistani families.

关键词： autosomal recessive retinitis pigmentosa PDE6A CDHR1 variants Pakistani families

Design, Modelling and Characterization of Transmission Lines for mm-Wave Silicon ICs

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Journal of Electrical Engineering 2016年第1期4卷 1-10页

作者： jan Dirk Leuiker David Fritsche Gregor Tretter Mahdi Khafaji Corrado Carta Frank Ellinger Chair for Circuit Design and Network Theory Technische Universitaet Dresden Dresden 01062 Germany

This article describes the design, modelling and characterization of transmission lines for millimetre wave silicon integrated circuits up to 65 GHz. The simulation results of three different EM （electro-magnetic） simulators for a selected hybrid coplanar layout structure are presented. Two different deembedding methods are investigated and compared with respect to sensitivity to typical measurement errors. Finally both methods are applied to the measurement results of the fabricated test structures in a 250 nm BiCMOS technology showing good agreement to EM simulations and predicted sensitivity to measurement errors.

关键词： Transmission line microstrip coplanar waveguide millimetre wave integrated circuits EM simulation deembedding.