Fast and accurate measurement of diffusion coefficient by Taylor’s dispersion analysis

This investigation aimed at improving the performance of Taylor's dispersion analysis for the fast and accurate measurement of diffusion coefficient of a minute solute in various solvents. The investigation was carried out on a capillary electrophoresis instrument by monitoring the UV absorption peak of a solute pulse and calculating the diffusion coefficient by peak efficiency. With L-phenylalanine as a main testing solute, some key factors were afterward disclosed including especially the capillary size, carrier flow velocity, injection volume and capillary conditioning. Peak tailing, large volume of sample injection and slow migration were found to underestimate the diffusion coefficient while very fast migration and high sample concentration caused overestimation. At a moderate flow velocity of 0.1―1 cm/s with a capillary of 72.44 μm I.D.×60 cm (50 cm effective) maintained at 25℃, the diffusion coefficient of aqueous L-phenylalanine was determined, giving a value of 7.02×10-6 cm2/s with error＜2% and relative standard deviation＜0.2% (n=3). The method was shown to be applicable to the measurement of various samples such as aqueous phenylalanine, acetone, phenol, toluene and benzene, and nonaqueous benzene (in ethanol or 1-butanol).     

Analysis of Male Sterility-Related Proteins of Young Panicle in Rice （Oryza sativa L. ） by Two-Dimensional Electrophoresis

For searching out male sterility-related proteins (polypeptides) in rice (Oryza sativa L.), we examined the difference of panicle protein (polypeptides) between hybrid rice (Wujin2A/R168, Wujin5A/R988) and their parents (male-sterile line Wujin2A, Wujin5A, and restorer line R168, R988) at the formation stage of pollen mother cell by two-dimensional electrophoresis (2-DE). The results revealed that the 2-DE polypeptide maps were similar among these experimental materials. A small group of polypeptides were disappeared in 2-DE polypeptide maps of male-sterile line (Wujin2A, Wujin5A) by comparing to restorer line (R168, R988) and the first filial (F₁) generation (Wujin2A/R168, Wujin5A/R988). The isoelectric points of these polypeptides were pI 5.8–6.5 molecular, weight 42.7×10³−66.2×10³. Foundation item: Supported by the National Natural Science Foundation of China (30340079) and the Science and Technology Key Research Foundation of the Education Ministry of China (03109) Biography: HU Yao-jun (1960-), male Ph. D candidate, research direction: molecular cytogenetics.     

Purification and Characterization of an Antibacterial Protein from the Cultured Mycelia of Cordyceps sinensis

0 IntroductionAlnattie mdicfrroobmiala p wriodteei nvsar iheatdy boefe linv ifnogun odr gaanndis ismos--Bacteria[1], fungi[2 ,3], plants[4]and ani mals[5].Those proteins displayed a wide spectrumof anti mi-crobial activity against different species of viruses ,bacteria andfungi .Over the past few years ,several anti microbialpeptides and proteins were foundinfungus ,such asAFP fromAspergillus giganteus[6], Anafp fromAspergillus niger[7], Zygocin fromthe yeastZy-gosaccharomyces bailii[8],an…     

Spectrofluorimetric determination of magnesium (II) with 7-(8-Hydroxy-3, 6-disulfonaphthylazo)-8-hydroxyquinoline-5-sulfonic acid

A new fluorescent reagent, 7-(8-hydroxy-3, 6-disulfonaphthylazo)-8-hydroxyquinoline-5-sulfonic acid (HDNHQ) for the determination of magnesium has been developed. It reacted with magnesium to form a 1∶1 fluorescent complex withλ _ex/λ _em immediately at room temperature in ammonia-ammonium chloride buffer (pH 10.7). A linear relationship was obtained in the magnesium concentration range of 0–160 ng·mL⁻¹ with the detection limit of 0.04 ng·mL⁻¹. The proposed method was simple, rapid and sensitive. It has been successfully applied to the determination of trace magnesium in blood serum with recoveries of 103.75% and 98.16%, respectively. Foundation item: Supported by the Zi-Qiang Foundation of Wuhan University Biography: Zhang Xian (1975-), female, Ph. D candidant, research direction: organic reagent synthesis and analysis.     

A Note on the Multifractal Decomposition of Directed Graph Self Similar Sets

We investigated the directed graph self similar sets under some weak overlapping condition. We get the multifractal decomposition formulas for these sets, i. e.,dim Ku^a DimKu^a =f(a), where fis the multifractal spectral function of the directed graph self similar measure. Especially, the results improve that of Edgar and Mauldin to the case which allows certain overlapping.     

A tumor suppressor genefhit prokaryotic expression and identification

The recombinant expression vector pGEMD-fhit which contains full encoding region offhit gene was constructed. The recombinant was introduced into the BL21 (DE3) strain ofE. coli and induced by 1 mmol/L IPTG to express a 29×10³ polypeptide offhit fusion protein. And the 29×10³ protein was sensitive and specific in reaction with anti-fhit antibody in Western blot. Foundation item: Supported by the National Natural Science Foundation of China (39770373) Biography: SUN Yan (1975−), female, Master of science, Research direction: gene engineering     

Fast cholesky factorization algorithm for s. p. d block-Toeplitz matrices

A fast Cholesky factorization algorithm based on the classical Schur algorithm for themp×mp symmetric positive definite (s. p. d) block-Toeplitz matrices is presented. The relation between the generator and the Schur complement of the matrices is explored. Besides, by applying the hyperbolic Householder transformations, we can reach an improved algorithm whose computational complexity is2p ²m³−4pm³+3/2m³+O(pm). Foundation item: Supported by the Natural Science Foundation of Hubei province Biography: ZHANG Li(1973-), Female, MS, Research interests is in numerical algebra.     

Bis(7)-tacrine ameliorates cognitive impairment caused by cerebral hypoperfusion in rats

The effects ofbis(7)-tacrine, a novel acetylcholinesterase inhibitor, on cognitive impairment and neuronal degeneration induced by permanent ligation of bilateral common carotid arteries (2VO) were investigated using the Morris water maze in rats. Once daily oral administration ofbis(7)-tacrine (0.025, 0.05 and 0.1 mg·kg⁻¹) was started 14 days after 2VO operation. Over a three-week treatmentbis(7)-tacrine effectively reversed 2VO-induced spatial memory deficits in a dose-dependent fashion. Furthermore, histological observation showedbis(7)-tacrine decreased the neuropathological changes in the 2VO rats brain. These results suggest thatbis(7)-tacrine has therapeutic potential for the treatment of dementia caused by chronic cerebral hypoperfusion. Foundation item: Supported by the National Natural Science Foundation of China (No: 30170335) Biography: Peng Feng-fang(1966-), female Master, research direction: Alzheimer's disease and ischemia     

Investigation of performances and mechanism of fluoride removal by Fe (III)-loaded ligand exchange cotton cellulose adsorbent

Novel adsorbent, Fe(III)-loaded ligand exchange cotton cellulose adsorbent [Fe(III)LECCA], was used to investigate the adsorption performances and mechanism of fluoride removal from aqueous solutions. The adsorbent was found to adsorb fluoride rapidly and effectively. The fluoride removal was influenced by pH. Adsorption model followed first-order reaction at different temperature, theapparent adsorption activated energyE, was 6.37 kJ·mol⁻¹, and adsorption enthalpy ΔH was 5.35 kJ·mol⁻¹. The adsorption capacity of fluoride on adsorbent was 3.2 mmol·g⁻¹ (dry weight). The maximal integer coordination ratio of fluoride with Fe(III) LECCA was 3∶1. The ligand exchange mechanism of adsorption was elucidated through chemical methods and IR spectral analysis. Foundation item: Supported by the National Natural Science Foundation of China (29977010) and Shanghai Priority Academic Discipline Biography: ZHAO Ya-ping (1974-), female, Ph.D., research direction: water and wastewater treatment.     

The structure of one type of non-abelian group

By the property of the solvable group and the extending theorem of group, the authors acquired the structure of one type of Non-Abelian group. And we proved that when order is 10p ⁿ (p#2,5) and the sylowp-subgroup is cyclic, the group has twenty types. Whenp#3, it has 12 types and whenp=3, it has 8 types. Foundation item: Supported by the Natural Science Foundation of Hubei Province (No. 99J165) Biography: Huang Ben-wen (1948-), male, Professor, research direction: theory of groups.     

Cloning and Characterization of the fecC Gene Necessary for Optimal Growth under Iron-Deficiency Conditions in the Cyanobacterium Anabaena sp. PCC 7120

The fecC gene encoding a putative iron (Ⅲ) dicitrate transporte rwas cloned from nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120, and inactivated. The mutant grows normally in medium with NO3^- , NH1^- or without combined nitrogen. But in iron-deficient medium, the mutant grows slowly. Photosynthetic properties were compared between the mutant and the wildtype strain, the content of photosynthetic pigments in the mutant is lower than that of the wild-type. The results of RT-PCR experiments show that the fecC gene is expressed under iron-deficient conditions, but is not expressed under iron-replete conditions. These results revealed that fecC gene product is required for optimal growth under iron-deficient conditions in Anabaena sp. PCC 7120.     

Studies on the utilization potentiality of the nucleo-cytoplasmic hybrid in wheat

A series of comparative studies was carried out on the genetic effects of 25 alien cytoplasms of wheat on the growth potential, heading stage, fertility, resistance against diseases, important agronomic traits and its heterosis of 125 nuclei-cytoplasmic hybrids of wheat. The results indicated that there were clearly effects of alien cytoplasms on some characteristics, but the nucleus still exerted main effect on other characteristics. The effect of interactions between nucleus and cytoplasm was comparative obvious in some combination. Consequently, when we utilize the effects of alien cytoplasms, we should pay full attention to the facts such as the characteristic to be improved, the effects of cytoplasm, nucleus, the nucleus-cytoplasm interactions on that characteristics. From the preliminary studies, we believed that the cytoplasmic types of M⁰, S¹, S^v, D², D and B, and the nucleo-cytoplasmic hybrids of (Ae. sharonensis)-B174, (Ae. squarrosa)-352-35 (Ae. cylindrica)-352-35, (Ae. cylindria)-E EN-1, (Ae. cylindrica)-NPFP, and (Ae. speltoides)-352-35 would have some utilization potentiality in cultivar improvement. Foundation item: supported by the Foundation of National 8th Five-year-plan of China Biography: CHEN Jun-ying, (1964-), male, lecturer, and now worked in Henan Agricultural University, Zhengzhou 450002, China     

Purification and inhibition fungal growth of chitinases from<Emphasis Type="Italic">Vibrio pacini</Emphasis>

Vibrio pacini synthesizes multiple chitinases, of which three have been purified in this study by ammonium sulphate fractionation, chitin affinity chromatography and gel chromatography. Molecular weights of the three chitinases, Chi1, Chi2 and Chi3 are 27×10³, 39×10³ and 46×10³ respectively, as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The purified enzymes have optimal activity at pH 7–8, and retain 50% enzymatic activity pH 4–9. The activities of chitinases are inhibited by Pb²⁺, Fe³⁺ and Cu²⁺, and increased by Ca²⁺, Mg²⁺ and Mn²⁺. Chi3 is found to inhibit the growth of six species of fungi. Such characters of chitinase are different from those of any other chitinase that were reported before. Foundation item: Supported by the Key Technologies Research and Development Programme of the Tenth Five-Year Plan of the Nation Scientific and Technological Development (2001 BA708B04-07) Biography: HAN Bao-qin (1963-), female, Professor.     

Study on synthesis and biological activities of novel water-soluble metalloporphyrins

The synthesis and characterization of a series of metal porphyrins, M^II(Por), {Por=dianionic of 5, 10, 15, 20-tetrakis [4-(4′-bromobutyloxy) phenyl]porphyrinato and 5, 10, 15, 20-tetrakis [4-(4′-butyloxypyridine bromide)phenyl]porphyrinato, M=Zn, Cu, Mn, Co, Ni, Ru-CO} were described. The complexes 3a-3e were prepared from the reactions of compound 2 with metal acetates in chloroform, and the treatment of 3a-3f with excess of pyridine gave corresponding complexes 4a-4f. These new compounds were identified by absorption spectroscopies,¹H-NMR and elemental analyses. The results of biological activity testing for 4a-4f revealed that 4a and 4c had stronger inhibiting action on the growth metabolism ofEsche richia coli. Foundation item: Supported by the National Natural Science Foundation of China (No: 29972035) and the Zi-Qiang Science Foundation of Wuhan University, 2000 Biography: Li Zao-ying (1949-), famale, Professor, research interests, study on synthesis and biological activities of metalloprphrins.     

Cloning,expression of<Emphasis Type="Italic">Crocus sativus</Emphasis> phytoene desaturase gene and preparation of antiserum against it

A 2 149 bp full length phytoene desaturase (PDS) cDNA was first cloned from saffron (Crocus sativus L.) stigma using RT-PCR technique and a rapid amplification of cDNA end (RACE) strategy. The cDNA has an open reading frame of 1 697 bp, which encodes a polypeptide of 565 amino acids. The coding region of the cDNA was inserted into a prokaryotic expression vector pET-21a(+) and over-expressed inE. coli BL21 (DE3). The fusion proteins were found largely in an insoluble inclusion bodies. The purified fusion protein was used to immunize rabbits to obtain polyclonal antiserum with titer of 1×10⁵. Western blot analysis by using this particular antiserum showed that the higher expression level of PDS in mature stigma than in leaves and stamen, and the higher expression level of PDS in mature stigma than in young stigma. Foundation item: Supported by the Doctoral Foundation of the Ministry of Education, P. R. China and the Young Science Foundation of Sichuan University (Grant 0020405505012) Biography: Bai Jie (1968-), female, Ph. D candidate, research direction: plant developmental biology and reproductive engineering.     

Fluorescence Determination of Artemisinin Using Hemoglobin as Catalyst and Pyronine B as Substrate

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…     

On the Family of Thue Equation ｜x^3 ＋ mx^2y-（ m ＋ 3）xy^2 ＋ y^3｜= k

The family of cubic Thue equation which depend on two parameters ｜ x^3 ＋ mx^2 y-（m＋3） xy^2＋y^3｜=k is studied. Using rational approximation, we give a smaller upper bound of the solution of the equation, that is quite better than the present result. Moreover, we study two inequalities ｜ x^3 ＋ mx^2y-（m ＋ 3） xy^2＋y^3 ｜ =k≤2m＋3 and ｜x^3 ＋mx^2y- （m＋3）xy^2 ＋ y^3｜ = k≤ （2m＋3）^2 separately. Our result of upper bound make it easy to solve those inequalities by simple method of continuous fraction expansion.     

HPLC determination of ascorbic acid using luminol-Cu (II) chemiluminescence-application to the analysis of Juice beverage

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.     

The discharge and charge behavior of the Pb-Birnessite in LiOH aqueous solution

0　IntroductionManganeseoxideshavebeenwidelystudiedasbatterycathodesbecauseofitslowcostandlowtoxicity .Muchefforthasbeenfocusedonthespinelphase ,γ MnO2 andse verallayeredmanganeseoxidesinaqueousandnon aqueous .Sothereismuchinterestinmanganeseoxidesforuseascathodematerialsforadvancedlithiumbatteriestoreplacetheexpensivelithiumcobaltornickelsystem .ButthespinelLixMn2 O4hasthelowerratecapabilityandlowertheoreti calcapacityandγ MnO2 hasunsatisfactoryreversibilityinaqueous,thereby ,theiradvant…     

Statistical Characteristics of the Complexity for Prime-Periodic Sequences

Using the fact that the factorization of x^N-1 over GF(2) is especially explicit, we completely establish the distributions and the expected values of the linear complexity and the k-error linear complexity of the N-periodic sequences respectively, where N is an odd prime and 2 is a primitive root modulo N. The results show that there are a large percentage of sequences with both the linear complexity and the k-error linear complexity not less than N, quite close to their maximum possible values.