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1.
By using LKB-2277 Bioactivity Monitoring System, the heat effect changes in the process of inhibitory action of clarithromycin
and erythromycin onEscherichia coli at 37°C were determined. Quantitative analysis showed that relationship between antibiotic concentrationc and rate contantk ofEscherichia coli growth, and half inhibitory ratio concentration IC50: clarithromycin:k=0. 030 03–1. 1736×10−3
c, 8. 45 mg ·L−1; erythromycin:k=0.031 08–8.4657×10−4
c, 14. 45 mg·L−1. As a result of the microcalorimetry experiments, it not only indicated that antibacterial activity of clarithromycin was
stronger than that of erythromycin, but also reported the changeable features of thermodynamics of the bacterial cell in biological,
biochemical and metabolic process under different drug action.
Foundation item: Supported by Natinal Natural Science Fundation of China (29973030), Natural Science Fundation of Hubei Province
(98J052) and Post-doctoral Science Fundation of China
Biography, SHEN Xue-song (1956-), Associate professor Research direction: biothermochemistry. 相似文献
2.
The electroanalytical method of ferriheme was studied by linear sweep voltammetry in medium of 0.05 mol/L Tris+0.05 mol/L
NH3−NH4Cl buffer at hang mercury drop electrodes (HMDE). Heme exhibits two pair reversible redox peaks and one irreversible peak.
The cathodic peak potentials are−;0.236 V, −0.422 V and −1.408 V respectively. The first and the third peaks can be used for
directly quantitative determination of heme concentrations. The peak currents are good linear relationship with heme concentration
in ranges of 3×10−6–6×10−5 mol/L and 3×10−7–1.5×10−5 mol/L respectively.
Supported by the National Natural Science Foundation of China
Lju Huihong: born in 1965, Lecturer. Visiting scholar from Xiangyang Teacher’s College, Hubei, 441053 相似文献
3.
The state of Tb3+ is investigated in liposome. When the concentration of PC is below CMC (critical micell concentration), most of Tb3+ is associated with PC, the binding constant is about 3.35×103 L/mol. When the concentration of PC is beyond CMC, most of Tb3+ is dimerized, the dimerization constant is about 3.92×104L/mol. In PC−CH−H2O system, the binding constant of Tb3+−CH complex 2.93×104L/mol is obtained.
Biography:Mu Xiao-jing (1974-), female, MS. 相似文献
4.
A novel spectrofluorimetric method for the determination of L-ascorbic acid is proposed. It is based on the inhibition of
L-ascorbic acid on the formation of 2,3-diaminophenazine, which is an oxidation product ofo-phenylenediamine catalyzed by laccase. The fluorescence (at λcx/λcm=464 nm /530 nnm) was enhanced strongly in the presence of organic media. The mechanism ofo-phenylenediamine oxidation reaction catalyzed by laccase in the presence of L-ascorbic acid is discussed. L-ascorbic acid
is determined in the ethanol, 1,4-dioxane and acetone over the linear range of 4.0×10−7≈1.2×10−4 mol/L, 4.0×10−7≈8.0×10−5 mol/L and 4.0×10−7≈1.0×10−4 mol/L with a detection limit of 1.20×10−5 mol/L, 1.19×10−5 mol/L and 1.24×10−8 mol/L, respectively. The method has been successfully applied to the simple and rapid determination of L-ascorbic acid in
pharmaceuticals and milk powder.
Supported by National Natural Science Foundation of China and the Special Funds of State Education Committe for Doctorate
Research
Huang Zuyun: born in Aug. 1963. Ph.D 相似文献
5.
Wu Feng-wu Ai Xin-ping Yan Chen-nong He Zhi-ke Meng Hui Zeng Yun-e 《武汉大学学报:自然科学英文版》2002,7(3):341-344
The light emission produced by thiourea in oxidation process by permanganate in acidic solution in the presence of Ru(phen)
2
3
+ is used to determine 1.0×10−5 −1.0×10−5 mol/L thiourea. The limit of detection is 9.8×10−9 mol/L and the relative standard deviation is 1.1% for a 1.0×10−5 mol/L thiourea solution (n=10). The method was applied satisfactorily to the determination of thiourea.
Foundation item, Support by Ministry of Education, Wuhan University and Alumni Association of it
Biography: Wu Feng-wu(1963-), Male, Ph. D, research direction: analytical chemistry. 相似文献
6.
The chemiluminescence (CL) of luminol-Cu (II) was applied to HPLC determination of ascorbic acid, which was separated by a
C18 reverse-phase column with a mobile phase of 0.25 mol/L HAc. The eluted ascorbic acid was mixed with 0.3 mmol/L luminol and
0.05 mol/L CuSO4. The light emission from the reaction of Cu(II) oxidized ascorbic acid and luminol was detected by a modified luminometer.
The detection limit was 3.6×10−6 mol/L for ascorbic acid at aS/N ratio of 3, and the linear calibration range was 2×10−4–2×10−3 mol/L. The relative standard deviation for 5 replicate injections of 1×10−3 mol/L ascorbic acid was calculated as 4.3%. The method was successfully applied to determination of ascorbic acid in juice
beverage.
Foundation item: National Natural Science Foundation of China (29605001)
Biography: Wu Feng-wu(1963-), male, research direction: analytical chemistry. 相似文献
7.
A new chemiluminescence (CL) method for the determination of tetracycline and oxytetracycline is developed, based on the CL
reaction of tetracycline and oxytetracycline with Ru (bipy)3
2+ and Ce (IV). In sulfuric acid medium, the CL emission is generated upon continuous oxidtion of Ru(bipy)3
2+ by cerium (IV). The emission intensity is greatly enhanced when tetracycline and oxytetracycline are introduced into the
reaction system after acid degradation. Under the optimum conditions, the calibration curves are linear over the range of
8.0×10−8∼4.0×10−6 mol/L for tetracycline and of 2.0×10−7∼4.0×10−5 mol/L for oxytetracycline, with the detection limits are 4.2×10−8 mol/L for tetracycline and 1.5×10−7 mol/L for oxytetracycline, respectively. The proposed method was used for the determination of tetracycline and oxytetracycline
in pharmaceutical formulations with good results.
Foundation item: Supported by the National Natural Science Foundation of China and the Natural Science Foundation of Hubei
Province.
Biography: HAH He-you (1962), male, Associate profeddor, Ph.D graduate candidate. Present address, Department of Chemistry,
Huainan Teacher's College, Huainan. 相似文献
8.
CHEN Lihua~ ZHANG Yongkang~ YIN Hong~ LIU Liuzhan~ YANG Zhaoxia~ SHEN Hanxi~ . College of Chemistry Chemical Engineering Jishou University Jishou Hunan China . College of Chemistry Nankai University Tianjin China 《武汉大学学报:自然科学英文版》2006,11(3):704-708
0 IntroductionMaalnadria siusb atr ompajicosr .he aAltrthe pmrisoibnlienmi (n qtihneghtraoopsiucs,QHS,Fig.1) is a sesquiterpene endoperoxide isola-ted fromArtemisia annuaL., an ancient Chineseherbal medicine usedfor treatment of fever and ma-laria.Studies of the structure and activity relation-ship have shownthat endoperoxide groupis essentialfor anti malarial activity of QHS and absence of thismoiety lead to completely loss in activity of thedrug. Many techniques have been developed to de… 相似文献
9.
Determination of isocarbophos by cathodically sweeping oscilliopolarography is described. In a 1.0×10−5 mol/L sodium dodecylbenzene sulfonate (SDS)+0.1 mol/L HAC-NaAC (pH=4.0) buffer medium, isocarbophos and its alkaline hydrolysate
exhibited sensitive second derivative wave at −0.50 V and −0.48 V respectively. The peak current was linearly proportional
to the concentration of isocarbophos in the range of 5.40×10−6−1.05×10−4 mol/L by detecting isocarbophos directly. The detection limit was 3.60×10−6 mol/L with the relative standard derivation (RSD) of 7.3%. By employing an alkaline hydrolysis, the peak current was linearly
proportional to the concentration of isocarbophos in the range from 7.70×10−7 mol/L to 1.24×10−4 mol/L, and the detection limit was 5.80×10−7 mol/L with RSD of 3.1%. The hydrolysis procedure and the electrode reaction were studied by voltammetry.
Foundation item: Supported by the Foundation of Chinese-France Cooperation Program on Advanced Research
Biography: ZHANG Wu-ming (1929-), female, Professor. 相似文献
10.
A series of experimental methods including 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) test, alkaline
phosphatase (ALP) activity measurement, mineralized function, Oil Red O stain and measurement were employed to assess the
effect of Dy3+ on the osteogenic and adipogenic differentiation of mouse primary bone marrow stromal cells (BMSCs) and the adipogenic trans-differentiation
of mouse primary osteoblasts (OBs). The results showed that Dy3+ had no effect on BMSC proliferation at concentrations of 1×10−8 and 1×10−5 mol/L, but inhibited BMSC proliferation at other concentrations. Dy3+ had no effect on OB proliferation at concentrations of 1×10−10 and 1×10−9 mol/L, but inhibited OB proliferation at other concentrations. Dy3+ had no effect on the osteogenic differentiation of BMSCs at concentrations of 1×10−9 and 1×10−7 mol/L, and promoted osteogenic differentiation of BMSCs at other concentrations at the 7th day. The osteogenic differentiation
of BMSCs was inhibited by Dy3+ at concentration of 1×10−5 mol/L at the 14th day, but promoted osteogenic differentiation of BMSCs at concentrations of 1×10−9, 1×10−8, 1×10−7 and 1×10−6 mol/L with the maximal effect at concentration of 10−6 mol/L. Dy3+ promoted mineralized function of BMSCs at any concentration. Dy3+ had no effect on adipogenic differentiation of BMSCs at concentration of 1×10−7 mol/L, but inhibited adipogenic differentiation of BMSCs at other concentrations. Dy3+ inhibited adipocytic trans-differentiation of OBs at any concentration, suggesting that Dy3+ had protective effect on bone and the protective effect on bone may be mediated by modulating differentiation of BMSCs away
from the adipocyte and inhibiting adipocytic trans-differentiation of OBs which may promote differentiation and mineralization
of OBs. These results may be valuable for better understanding the mechanism of the effect of Dy3+ on pathogenesis of osteoporosis.
Supported by the Foundation for Key Program of Ministry of Education of China (Grant No. 208018) 相似文献
11.
Photosynthetic inorganic carbon utilization was investigated in two cyanobacteria Microcystis aeruginosa and Synechocystis PCC6803 grown in standing culture. Photosynthetic rates for the two algae reached about 10 times the theoretical CO2 supply rate at low dissolved inorganic carbon (DIC) of 100 μmol/L, and the rates were unaffected by the addition of 20 mmol/L Na+, indicating that the two algae possessed Na+-independent HCO-3 utilization for photosynthesis under low DIC. Their photo- synthetic rates at low DIC were inhibited by higher Cl- and the degrees of inhibition were increased with the rise of CI- concentration, and in the presence of Diphenylamine-2-carboxylate (DPC), a reported Cl- channel inhibitor, the rates decreased by 74%-82%, implying that putative DPC-sensitive Cl- channels participate in Na+-independent HCO3- uptake for photosynthesis. The experiment of intracellular 14C-DIC accumulation for photosynthesis showed that internal DIC pools decreased by about 80% with 200 μmol/L DPC and by 64%-70% with 100 mmol/L Cl-. The experiment of chlorophyll a fluorescence quenching showed that initial rates and extents of fluorescence quenching obviously decreased with 200 μmol/L DPC or 100 mmol/L Cl-. The two experiments gave further evidence that putative DPC-sen- sitive Cl- channels participate in Na+-independent HCO-3 uptake for photosynthesis in the two algae grown in standing culture. 相似文献
12.
Electrochemical behavior of a carbon paste electrode (CPE) modified with nickel(II)-5, 11, 17, 23-tetra-tert-butyl-25, 27-bis(diethylcarbamoylmethoxy)
calix[4]arene (Ni (II)-L) complex and its electrocatalytic activity towards the oxidation of hydrogen peroxide were investigated
by cyclic voltammetric technique in a 5.0×10−2 mol/L NaClO4+1.0×10−3 mol/L NaOH solution. It was found that Ni(II)-L acts as an effective catalyst for the oxidation of hydrogen peroxide. The
modified electrode exhibited a linear response over a hydrogen peroxide concentrations in the range of 2.0×10−5−1.0×10−4 mol/L with a detection limit as low as 1.0×10−6 mol/L. The relative standard deviation was 3.5% for 5 successive determinations of H2O2 at 1.0×10−5 mol/L. The modified electrode was used successfully in rainwater analysis.
Foundation item: Supported by the Natural Science Foundation of Hubei Province (98J040).
Biography: Li Chun ya(1972-), Ph. D. candidate, research direction: electroanalysis and electrosynthesis. 相似文献
13.
Crystal structure and negative thermal expansion of solid solution Lu<Subscript>2</Subscript>W<Subscript>3−<Emphasis Type="Italic">x</Emphasis></Subscript>Mo<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>O<Subscript>12</Subscript>
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Jie Peng Xin-zhi Liu Fu-li Guo Song-bai Han Yun-tao Liu Dong-feng Chen Zhong-bo Hu 《矿物冶金与材料学报》2010,17(6):786-790
A new series of solid solutions Lu2W3−x
Mo
x
O12 (0.5≤x≤2.5) were successfully synthesized by the solid-state method. Their crystal structure and negative thermal expansion properties
were studied using high-temperature X-ray powder diffraction and the Rietveld method. All samples of rare-earth tungstates
and molybdates are found to crystallize in the same orthorhombic structure with space group Pnca and show the negative thermal expansion phenomena related to transverse vibration of bridging oxygen atoms in the structure.
Thermal expansion coefficients (TEC) of Lu2W3−x
Mo
x
O12 are determined as −20.0×10−6 K−1 for x=0.5 and −16.1×10−6 K−1 for x=2.5 but -18.6×10−6 and −16.9×10−6 K−1 for unsubstituted Lu2W3O12 and Lu2Mo3O12 in the identical temperature range of 200 to 800°C. High-temperature X-ray diffraction (XRD) data and bond length analysis
suggest that the difference between W-O and Mo-O bond is responsible for the change of TECs after the element substitution
in this series of solid solutions. 相似文献
14.
Zhenrong Sun Shenyi Wang Yanping Huang Jiyun Lin Liangen Ding Zugeng Wang 《科学通报(英文版)》1998,43(5):399-402
The nonlinear refractive indexesn
2 for the ethanol solutions of 1, 10-phenanthroline (2.0 × 10−3 mol · L−1), [bis(l, 10-phenanthroline) lanthanum (III)] nitrate (1.0 × 10−3 mol · L−1), and [nitrato-fluoracil-bis (1, 10-phenanthroline) lanthanum (III) ] nitrate (1.0 × 10−3 mol · L−1) are first measured, the third-order nonlinear optical susceptibilities χ(3) and 〈γ〉 are calculated, and the mechanisms of the third-order optical nonlinearities enhanced by lanthanum (III) are discussed
preliminarily. 相似文献
15.
SHI Bo’an~ ZENG Danyun~ JI Xinghu~ XI Juan~ AI Xinping~ HE Zhike~ . College of Chemistry Molecular Sciences Wuhan University Wuhan Hubei China . Department of Chemistry Chemical Engineering Hubei Institute for Nationalities Enshi Hubei China 《武汉大学学报:自然科学英文版》2006,11(3):672-676
0 IntroductionThbiep ycroidmipnlee)xru ctahteinoinu mof(Ⅱ r)u t(he Rniuu(mbip,y m)3ai2n +ly) atrnids- t(r2is -,(21’ -,10-phenanthroline)ruthenium(Ⅱ) (Ru(phen)32 +) ,is a kindof sensitive analytical reagent for electrogenerated chemilumi-nescence(ECL) and chemiluminescence(CL) ,on which a par-ticular review has been presented[1]. The earliest publicationon the synthesis of Ru(bipy)32 +appeared in 1936[2], andduringthefollowing30 years ,theinvestigations relatedtothissubstance were only in… 相似文献
16.
A second derivative polarographic wave of naphthalene is observed in 50% N, N-dimethylformamide and ammonia-ammonium chloride
medium. The peak potential is about −1.05 V (vs. SCE). The concentration of naphthalene is linear with peak current in the
range of 5.00×10−6 mol/L to 5.00×10−4 mol/L, The detection limit is 2.00×10−6 mol/L. This method can be used to determine naphthalene content of the sample such as coal, mothball and asphaltic bitumen.
The relative standard deviation (RSD) are in the range of 0.38%≈1.30%. The determined recoveries by adding known amounts of
naphthalene to sample solution are in the range of 92%≈101%. This paper also study on the polarographic behavior of naphthalene.
Biography: ZHANG Li-hua (1974-), female, Master. 相似文献
17.
ZHENG Qi~ CAO Qihua~ LIU Zhihong~ CAI Ruxiu~ . College of Chemistry Environmental Engineering Jianghan University Wuhan Hubei China . College of Chemistry Molecular Sciences Wuhan University Wuhan Hubei China 《武汉大学学报:自然科学英文版》2006,11(3):677-681
0 IntroductionSltougdiiceasl csoynstceermnsin gharveeac btieveen o txhyeg ei nm psopretcaienst ( oRbjOecSt) iinn bbiioo--medicine and analytical chemistry in recent years[1-4]. Manyi mportant life phenomena and diseases are relatedtotheinter-mediates of ROS[5-7].ROS have beeni mplicated as ani mpor-tant causative factor in cell damage,including apoptosis andnecrosis . Their proposed actions comprise lipid peroxidation,DNAdamage,the mitochondrial respiratory chain destructionand protein mo… 相似文献
18.
Zengzu Lai Dongsheng Xiong Dongmei Fan Yuanfu Xu Hanzhi Liu Hui Peng Zhenping Zhu Chunzheng Yang 《科学通报(英文版)》2001,46(14):1182-1186
The variable domain of heavy chain (VH) and light chain (VL) genes of anti-CD20 monoclonal antibody HI47 were cloned from anti-CD20 ScFv expression vector pCANBTEcd20 by PCR and ligated into vector pYZF to construct chimeric anti-CD20
Fab’ fragment expression vector pYZFcd20. Chimeric anti-CD20 Fab’ fragment was expressed inE. coli 16C9 and purified by protein G affinity chromatography. Competitive inhibition assay showed that anti-CD20 Fab’ fragment
inhibited binding of HI47 to CD20 on the surface of Daudi cells. Results from MTT assay indicated that chimeric anti-CD20 Fab’ fragment inhibited the
proliferation of Daudi cells, IC50 = 69 μg/mL. Affinity of chimeric anti-CD20 Fab’ fragment was determined, Ka was about 8.9×108 (mol/L)−1. 相似文献
19.
A new selenium source, Nano red elemental selenium (Nano-Se) was used to study the effect on the GPx activity of broiler chick
kidney cells (BCKC)in vitro, Sodium selenite (Na2SeO3) and seleno-1-methionine (Se-Met) were used as the controls. The results showed that the effects of three kinds of Se forms
on the GPx activity of BCKC were accordant (p>0.05) compared with each other at 0.01. 0.05 and 0.10 μmol/L Se concentrations treatments. In the range of 0.00–0.10 μmol/L
Se concentrations, the GPx activity increased with elevation of Se concentrations in medium. For the three kinds of Se forms,
the GPx activity reached the climax at 0.10 μmol/L Se concentration. At 0.20 and 0.30 μmol/L Se concentrations, the influnces
of three kinds of Se forms were not accordant with one another. For Nano-Se, the GPx activity at 0.20 and 0.30 μmoi/L Se concentrations
remained the same as that at 0.10 μmol/L Se concentration treatment. For Se-Met, the GPx activity at 0.20 μmol/L Se concentration
treatment remained the same with 0.10 μmol/L treatment; the GPx activity at 0.30 μmol/L Se concentration treatment was declined
significantly (p<0.05) compared with 0.10 or 0.20 μmol/L treatment. For Na2SeO3, the GPx activity falled gradually with Se concentration increasing from 0.10 μmol/L to 0.30 μmol/L, and at 0.30 μmol/L Se
concentration treatment, the GPx activity was less than the original of BCKC. The results implicated, on the GPx activity
of BCKCin vitro, the ranking of width range of the most suitable Se concentration for nutrition curve of the three Se formes is Nano-Se>Se-Met>Na2SeO3.
Foundation item: Supported by the Key Item of the Science and Technology Bureau of Zhejiang Province (021122680)
Biography: Xu Bao-hua (1966-), male, Associate professor, Ph. D. research direction: nanobiology and animal nutrition. 相似文献
20.
3-benzidino-5-methyl-6-phenylpyridazine (BMP) inhibited electric eel acetylcholinesterase (AChE), with IC50 being 0.58 μmol·L-1. As an AChE inhibitor, the effects of BMP on delayed rectifier potassium current (IK(DR)) and transient outward potassium current (IK(A)) in acutely isolated rat hippocampal pyramidal neurons were studied using the whole cell patch-clamp technique. BMP (0.1―50 μmol·L-1) inhibited IK(DR) and IK(A) in a concentration-dependent and voltage-independent manner. The IC50 value for the bl... 相似文献