[Identification of HBV infection-associated genes in first trimester human fetal hepatocytes with suppression subtractive hybridization].
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Adult↗
Biomedical subjects
Rui Zhang
Publications and source records attributed to Rui Zhang.
[Profile of the study of methods for detecting selenium].
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Animals↗
[The structural characteristics, alternative splicing and genetic experession analysis of ADP-ribosylation-factor 1 (arf1) in cotton].
The full-length cDNA,DNA and promoter of ADP-ribosylation-factor 1 (arf1) was isolated from Gossypium hirsutum Y18 by means of isocaudarner inverse PCR (II-PCR) and rapid isolating cDNA 5' unknown sequence and promoter (RICUP) established in our lab. Results indicated that the gene is 4 360 bp in size, including seven exons and six introns. Interestingly, alterative splicing occurs at intron I. Differential processing of intron 1 yields three different transcripts with 1 026 bp, 1103 bp and 1 544 bp in sizes, respectively. Arf1 encodes 181 amino acids. Sequence analysis indicated that sequence upstream transcription initiation site of arf1 includes typical initiator, TATA box, CCAAT box, GC box and several forward and reverse repeat sequences. And typical promoter structures, such as AT-rich sequence and palindrome structure have been detected in the sequence downstream transcription initiation site. Southern blot analysis indicated that the gene has two copies in the genome of cotton. Northern blot confirmed the predominate expression of arf1 in reproductive organs of cotton, including bud, flower, fiber and boll. Also, the feature and character of arf1 and its promoter have been studied. This study will lay foundation for the other research on function of arf1 in the development of reproductive organs in cotton.
ADP-Ribosylation Factor 1↗
Surfactants, polymers and their nanoparticles for personal care applications.
A "touch me not" plant folding up rapidly upon being attacked or microbes depositing on teeth or ocean vessels even under hostile conditions are examples in nature that provide inspiration for developing new classes of personal care release or deposition systems. In this paper, development of such systems based on polymer/surfactant colloid chemistry is explored for achieving transport and release of cosmetic and pharmaceutical molecules at desired rates at desired sites. The successful development of products depends upon understanding and utilizing key interactions among surfactants, polymers and hybrid polymers that are relevant to personal care products. Thus, the absorbed layers or tethers on the particulates can be manipulated for desired dispersion of actives or depositions on substrate under any and all conditions. New hybrid polymers and nanogels have been synthesized for tuning up nanodomains that can extract and deliver at will cosmetics/drugs/toxins by perturbing pH, temperature or ionic strength of the system. Particularly, hydrophobically modified polymers have features of both polymers and surfactants and due to the associative nature of the hydrophobic groups, such polymers can form intramolecular nanodomains for performing carrier functions. Nanogels developed recently include that of polyacrylamide, poly(acrylic acid) and starch nanogels modified for extraction and subsequent slow release of fragrances and overdosed toxic drugs. Binding and release processes were investigated using surface plasmon resonance and fluorescence spectroscopies, powerful techniques for monitoring short term and long term changes.
Cosmetics↗
[Expression of Vitreoscilla hemoglobin and nitrilase in the yeast Pichia pastoris].
The expression of the vgb gene in vivo could improve the fermentation density and then contribute the extracellular secretion of the product of bxn gene. Constructed the recombination plasmid pPIC9K-vgbbxn and transformed into Pichia pastoris GS115. The results of PCR and SDS-PAGE indicate that the vgb gene and bxn gene had integrated into the genome of Pichia pastoris GS115 and expressed in efficient level. Also, the protein activity of their products had been verified respectively. Shake flask fermentation experiments showed that the presence of VHb in yeast Pichia pastoris efficiently enhanced cell growth and secretive expression of bxn gene under hypoxic habitats.
Aminohydrolases↗
Methyl side-chain dynamics in proteins using selective enrichment with a single isotopomer.
13C relaxation studies on side-chain methyl groups in proteins typically involve measurements on (13)CHD(2) isotopomers, where the (13)C relaxation mechanism is particularly straightforward in the presence of a single proton. While such isotopomers can be obtained in proteins overexpressed in bacteria by use of (13)C enriched and fractionally deuterated media, invariably all possible (2)H isotopomers are obtained. This results in a loss of both resolution and sensitivity, which becomes particularly severe for larger proteins. We describe an approach that overcomes this problem by chemical synthesis of amino acids containing a pure (13)CHD(2) isotopomer. We illustrate the benefits of this approach in (13)C side-chain relaxation measurements on the mouse major urinary protein selectively enriched with [gamma(1),gamma(2)-(13)C(2),alpha,beta,gamma(1),gamma(1),gamma(2),gamma(2)-(2)H(6)] valine. Relaxation measurements in the absence and presence of pyrazine-derived ligands suggest that valine side-chain dynamics do not contribute significantly to binding entropy.
Animals↗
Analysis of self-assembled monolayer interfaces by electrospray mass spectrometry: a gentle approach.
A general mass spectrometry technique for the characterization of alkanethiol-modified surfaces is presented. Alkanethiol self-assembled onto a gold surface (in this case, peptides were attached to the gold surface via a thiolate bond) was reductively desorbed in 0.05 M KOH in the presence of octadecyl-derivatized silica gel. The peptide adsorbed onto the silica gel, whereupon it could be filtered, washed to remove any salts, and then eluted using a mixture of 4:1 v/v methanol/water. The eluant containing the peptide was injected into a Fourier transform ion-cyclotron resonance mass spectrometer (FTICR/MS) via electrospray ionization. The spectrum showed no fragmentation of the peptide, demonstrating the gentleness of the technique. This simple procedure is not limited to FTICR/MS and could be adapted to other mass spectrometers.
Gold↗
Chiral hydroperoxides as oxygen source in the catalytic stereoselective epoxidation of allylic alcohols by sandwich-type polyoxometalates: control of enantioselectivity through a metal-coordinated template.
The epoxidation of allylic alcohols is shown to be efficiently and selectively catalyzed by the oxidatively resistant sandwich-type polyoxometalates, POMs, namely [WZnM(2)(ZnW(9)O(34))(2)](q)(-) [M = OV(IV), Mn(II), Ru(III), Fe(III), Pd(II), Pt(II), Zn(II); q = 10-12], with organic hydroperoxides as oxygen source. Conspicuous is the fact that the nature of the transition metal M in the central ring of polyoxometalate affects significantly the reactivity, chemoselectivity, regioselectivity, and stereoselectivity of the allylic alcohol epoxidation. For the first time, it is demonstrated that the oxovanadium(IV)-substituted POM, namely [ZnW(VO)(2)(ZnW(9)O(34))(2)](12-), is a highly chemoselective, regioselective, and also stereoselective catalyst for the clean epoxidation of allylic alcohols. A high enantioselectivity (er values up to 95:5) has been achieved with [ZnW(VO)(2)(ZnW(9)O(34))(2)](12)(-) and the sterically demanding TADOOL-derived hydroperoxide TADOOH as regenerative chiral oxygen source. Thus, a POM-catalyzed asymmetric epoxidation of excellent catalytic efficiency (up to 42 000 TON) has been made available for the development of sustainable oxidation processes. The high reactivity and selectivity of this unprecedented oxygen-transfer process are mechanistically rationalized in terms of a peroxy-type vanadium(V) template.
Journal Article↗
Laser flash photolysis formation and direct kinetic studies of manganese(V)-oxo porphyrin intermediates.
Irradiation of porphyrin-manganese(III) perchlorate complexes in acetonitrile with 355 nm laser light gave MnV-oxo intermediates that were characterized by their UV-vis spectra and reactivities. The MnV-oxo species of tetrakis(pentafluorophenyl)porphyrin (2), tetraphenylporphyrin (4), and tetra-(4-(N-methylpyridiniumyl))porphyrin (6) were generated. Second-order rate constants for reactions of 2 with substrates were as follows: 6.1 x 105 M-1 s-1 (cis-stilbene), 1.3 x 105 M-1 s-1 (diphenylmethane), 1.3 x 105 M-1 s-1 (ethylbenzene), and 0.55 x 105 M-1 s-1 (ethylbenzene-d10). In oxidations of cis-stilbene and diphenylmethane, the order of reactivity of the MnV-oxo species was 2 > 6 > 4.
Kinetics↗
[The variation of T-cell clonal repertoire in patients with systemic lupus erythematosus (SLE) following autologous peripheral blood hematopoietic stem cell transplantation].
OBJECTIVE: Analyze the variation of T cell receptor(beta) (TCRbeta) CDR3 gene expressing repertoire in systemic lupus erythematosus (SLE) patients before and after autologous peripheral blood hematopoietic stem cell transplantation (APBSCT), to search the pathogenesis of SLE and characteristics of T cell reconstitute immune after APBSCT. METHODS: Reverse transcriptase - polymerase chain reaction (RT-PCR) amplified 25 subfamily genes of TCRbeta prom peripheral blood lymphocytes (PBLs) of SLE patient with APBSCT and run denaturation polyacrylamide sequencing gel electrophoresis, set up a map of TCRbetaCDR3 gene expressing repertoire. The bands of TCRbeta gene repertoire in the electrophoresis gel can be used to analyze the variety of T cell clones which expanded and disappeared in cases of SLE. Cut the bands and sequencing. Compare sequences of TCRbetagenes in normal and abnormal T cell clones to understand the relationship between TCRbeta gene and autoimmune diseases. RESULTS: In the normal control group, TCRbeta gene repertoires show more than 10 bands in each of 25 TCRbetaV families, characterized as Gaussian distribution. TCRbeta gene repertoire in the 8 patients with SLE were abnormally. Four patients expressed TCRbetaV13.1 gene preferentially. Three patients had TCRbetaV8, TCRbetaV9 and TCRbetaV18 genes over expressed. These over expressive genes represented the oligoclonal expansion of T cell populations. After APBSCT the TCRbeta gene repertoires regained CDR3 polymorphism in 5 patients, some of them recovered to normal completely. The sequencing analyse show dense and strong band in map of TCRbeta gene repertoires were T cell monoclonal or oligoclonal expansion frequently. In a case of SLE an amino acid sequence of TCRbetaV8 CDR3 was same to a sequence of disease correlative T cell clone with ankylosing spondylitis that had been reported in a literature before. CONCLUSION: SLE patients have oligoclonal expansion of T cell that related with the pathogenesis of autoimmune disease. After APBSCT, T cell clones recover to normal distribution. T cell clones that related with disease have been suppressed during immunological reconstitution. It may be a main reason the SLE get remission after transplantation.
Adolescent↗
Automated gain control and internal calibration with external ion accumulation capillary liquid chromatography-electrospray ionization Fourier transform ion cyclotron resonance.
When combined with capillary LC separations, electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR MS) has demonstrated capabilities for advanced characterization of proteomes based upon analyses of proteolytic digests. Incorporation of external (to the ICR cell) multipole devices with FTICR for ion selection and ion accumulation has enhanced the dynamic range, sensitivity, and duty cycle of measurements. However, the highly variable ion production rate from an LC separation can result in "overfilling" of the external trap during the elution of major peaks and result in m/z discrimination and fragmentation of peptide ions. Excessive space charge trapped in the ICR cell also causes significant shifts in the detected ion cyclotron frequencies, reducing the achievable mass measurement accuracy (MMA) and making protein identification less effective. To eliminate m/z discrimination in the external ion trap, further increase duty cycle, and improve MMA, we have developed the capability for data-dependent adjustment of ion accumulation times in the course of an LC separation, referred to as automated gain control (AGC). This development has been implemented in combination with low kinetic energy gated ion trapping and internal calibration using a dual-channel electrodynamic ion funnel. The overall system was initially evaluated in the analysis of a tryptic digest of bovine serum albumin. In conjunction with internal calibration, the capillary LC-ESI-AGC-FTICR instrumentation provided a approximately 10-fold increase in the number of identified tryptic peptides compared to that obtained using a fixed ion accumulation time and external calibration methods.
Journal Article↗
Synthesis of the novel liqustrazine derivatives and Their protective effect on injured vascular endothelial cell damaged by hydrogen peroxide.
A series of novel 2-acyloxymethyl-3,5,6-trimethylpyrazine derivatives was designed and synthesized. Most compounds were found to be 1.5-4.5-fold higher potency than tetramethylpyrazine (TMP) in stimulating the proliferation of normal vascular endothelial cells and in protecting against hyperoxic acute injury. The most active one is the 2-nicotinoyl ester 5a exhibiting the maximum proliferation rate (P(max)) of 88.57% at the concentration of 0.1 mmol L(-1). Structure-activity relationships of these compounds were discussed.
Antioxidants↗
Organic reactions and nanoparticle preparation in CO(2)-induced water/P104/p-xylene microemulsions.
Nanometer-sized gold particles are synthesized by the reduction of HAuCl(4) with KBH(4) in the CO(2)-induced microemulsion of (EO)(27)(PO)(61)(EO)(27) (P104; EO=ethylene oxide, PO=propylene oxide)/p-xylene/CO(2)/H(2)O. The recovery of gold particles from the microemulsion can be easily accomplished by the venting of CO(2), while the surfactant remains in the organic phase. The effect of the molar ratio of the reductant to HAuCl(4), the concentration of the reactants, and the molar ratio of water to EO segments (W(0)) in the reverse micelles on the size of the gold particles is studied. The hydrolysis of benzoyl chloride (BzCl) and p-nitrophenyl chloroformate (NPhCl) has also been carried out in the microemulsion. The results show that the observed rate constants k(obs) of both substrates increase significantly with W(0), and that W(0) has a larger influence on the hydrolysis of BzCl. The different extents of the influence of W(0) on the two reactions can be ascribed to the different reaction mechanisms and the expected changes in nucleophilicity and polarity of water in the reverse micelles.
Journal Article↗
Cold-active serine alkaline protease from the psychrophilic bacterium Pseudomonas strain DY-A: enzyme purification and characterization.
An extracellular protease was purified from a deep-sea psychrophilic bacterium strain DY-A which was identified as a Pseudomonas species. The optimal growth and protease-producing temperatures of the strain were all 10 degrees C, and the protease was secreted only at temperatures under 20 degrees C. The enzyme was most active at 40 degrees C and at pH 10.0. It was inhibited by phenylmethyl sulfonylfluoride and diisopropyl fluorophosphate, indicating that it is a serine protease. Chelators such as EDTA, EGTA, 1,10-phenanthroline and 2,2'-bipyridyl produced a decrease of activity. The enzyme was sensitive to denaturing agents such as SDS, urea, and guanidine HCl and resistant to thiol-containing reducing agents such as dithiotreitol. The enzyme was active towards N-succinyl-Ala-Ala-Pro-Phe- p-nitroanilide and N-succinyl-Ala-Ala-Pro-Leu- p-nitroanilide. The native molecular mass of the enzyme determined by native PAGE and SDS-PAGE was 25 kDa.
Chromatography, DEAE-Cellulose↗
A highly chemoselective, diastereoselective, and regioselective epoxidation of chiral allylic alcohols with hydrogen peroxide, catalyzed by sandwich-type polyoxometalates: enhancement of reactivity and control of selectivity by the hydroxy group through metal-alcoholate bonding.
Sandwich-type polyoxometalates (POMs), namely [WZnM2(ZnW9O34)2]q- [M = Mn(II), Ru(III), Fe(III), Pd(II), Pt(II), Zn(II); q = 10-12], are shown to catalyze selectively the epoxidation of chiral allylic alcohols with 30% hydrogen peroxide under mild conditions (ca. 20 degrees C) in an aqueous/organic biphasic system. The transition metals M in the central ring of polyoxometalate do not affect the reactivity, chemoselectivity, or stereoselectivity of the allylic alcohol epoxidation by hydrogen peroxide. Similar selectivities, albeit in significantly lower product yields, are observed for the lacunary Keggin POM [PW11O39]7-, in which a peroxotungstate complex has been shown to be the active oxidizing species. All these features support a tungsten peroxo complex rather than a high-valent transition-metal oxo species operates as the key intermediate in the sandwich-type POM-catalyzed epoxidations. On capping of the hydroxy functionality through acetylation or methylation, no reactivity of these hydroxy-protected substrates [1a(Ac) and 1a(Me)] is observed by these POMs. A template is proposed to account for the marked enhancement of reactivity and selectivity, in which the allylic alcohol is ligated through metal-alcoholate bonding, and the H2O2 oxygen source is activated in the form of a peroxotungsten complex. 1,3-Allylic strain promotes a high preference for the threo diastereomer and 1,2-allylic strain a high preference for the erythro diastereomer, whereas tungsten-alcoholate bonding furnishes high regioselectivity for the epoxidation of the allylic double bond. The estimated dihedral angle alpha of 50-70degrees for the metal-alcoholate-bonded template of the POM/H2O2 system provides the best compromise between 1,2A and 1,3A strain during the oxygen transfer. In contrast to acyclic allylic alcohols 1, the M-POM-catalyzed oxidation of the cyclic allylic alcohols 4 by H2O2 gives significant amounts of enone.
Journal Article↗
Highly efficient catalytic asymmetric epoxidation of allylic alcohols by an oxovanadium-substituted polyoxometalate with a regenerative TADDOL-derived hydroperoxide.
The oxovanadium(IV) sandwich-type POM catalyzes the chemo-, regio-, and stereoselective epoxidation of allylic alcohols by chiral hydroperoxides with very high catalytic efficiency (up to 42 000 TON), a potentially valuable oxidation for the development of sustainable processes. By using the sterically demanding, TADDOL-derived hydroperoxide TADOOH as the chiral oxygen source, enantiomeric ratios (er) of up to 95:5 have been achieved.
Journal Article↗
Characterization of piezoelectric materials with large piezoelectric and electromechanical coupling coefficients.
The relaxor based ferroelectric (1-x)Pb(Zn(1/3)Nb(2/3))O(3)-xPbTiO(3) and (1-x)Pb(Mg(1/3)Nb(2/3))O(3)-xPbTiO(3) single crystals provided new challenges in property characterization because their extraordinarily large piezoelectric coefficients and electromechanical coupling coefficients. Large errors may occur in some of the derived material constants using conventional characterization techniques. This paper will analyze the inadequacy of the traditional characterization methods and provide some basic guidelines for properly characterizing piezoelectric materials with extremely high piezoelectric and electromechanical coupling coefficients.
Crystallography↗
Detection of known mutations in hypertrophic cardiomyopathy using oligonucleotide microarrays assisted by improved base stacking hybridization.
With the assistance of improved base stacking hybridization, a low-density microarray, containing 12 capture probes, was used to identify 7 known hypertrophic cardiomyopathy-related mutations in the gene of MYH7 (beta-myosia heavy chain). The hybridization targets, amplified from 11 plasmids containing wild type or mutation sequences of MYH7 and healthy genomic DNA, were prepared by single-step fluorescence labeled asymmetric PCR. Six single base substitutions and a trinucleotide deletion were identified unambiguously, and the average discrimination ratio (Qmut) for artificial heterozygous samples was as high as 16.2.
Base Sequence↗