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Wu Z, Zhang ZZ, Chang K, Peeters FM. Quantum tunneling through graphene nanorings. NANOTECHNOLOGY 2010; 21:185201. [PMID: 20388970 DOI: 10.1088/0957-4484/21/18/185201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We investigate theoretically quantum transport through graphene nanorings in the presence of a perpendicular magnetic field. Our theoretical results demonstrate that the graphene nanorings behave like a resonant tunneling device, contrary to the Aharonov-Bohm oscillations found in conventional semiconductor rings. The resonant tunneling can be tuned by the Fermi energy, the size of the central part of the graphene nanorings and the external magnetic field.
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Su SC, Lu YM, Zhang ZZ, Shan CX, Li BH, Shen DZ, Yao B, Zhang JY, Zhao DX, Fan XW. Optical properties of ZnMgO nanowalls grown by plasma-assisted molecular beam epitaxy. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2010; 10:1681-1684. [PMID: 20355557 DOI: 10.1166/jnn.2010.2112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
ZnMgO nanowalls were prepared by plasma-assisted molecular beam epitaxy without a catalyst on c-Al2O3 substrate. The obtained nanowalls have preferred orientation along c axis. The nanowalls are about 10 to 20 nm in thickness and about 50 nm in height. Only Zn, Mg, O and Al signals are detected in the nanowalls from the energy dispersive spectroscopy (EDS). The Mg content is about 3% in ZnMgO nanowalls. The room temperature photoluminescence (PL) spectra shows the emission peak of the ZnMgO nanowalls at 3.346 eV. The origin of the ultraviolet emission is discussed with the help of temperature-dependent PL spectra. The ultraviolet emission band is free exiton recombination observed in the low temperature PL spectra (at 81 K). We also observe the free-to-acceptor (FA) emission of the ZnMgO nanowalls. The acceptor binding energy obtained from photoluminescence studies is about 123 meV. The results show that Mg doping leads to an increase of the acceptor binding energy. The possible growth mechanism of the ZnMgO nanowall networks was discussed.
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Zhang ZZ, Wu ZH, Chang K, Peeters FM. Resonant tunneling through S- and U-shaped graphene nanoribbons. NANOTECHNOLOGY 2009; 20:415203. [PMID: 19755722 DOI: 10.1088/0957-4484/20/41/415203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We theoretically investigate resonant tunneling through S- and U-shaped nanostructured graphene nanoribbons. A rich structure of resonant tunneling peaks is found emanating from different quasi-bound states in the middle region. The tunneling current can be turned on and off by varying the Fermi energy. Tunability of resonant tunneling is realized by changing the width of the left and/or right leads and without the use of any external gates.
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Zhang ZZ, Su SM, Luo YJ, Lu M. Improvement of natural microbial remediation of petroleum-polluted soil using graminaceous plants. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2009; 59:1025-1035. [PMID: 19273903 DOI: 10.2166/wst.2009.081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A 150-day pot experiment was conducted with graminaceous plants grown in natural soil contaminated with petroleum. The relationships among microbial activity, dehydrogenase activity, catalase activity, soil moisture, and the petroleum degradation rate were analyzed. All three plants accelerated the degradation of petroleum compared with unplanted soil. Plant roots improved the soil moisture by about 5% (from 15% in unplanted soil to 20% in soil containing plant roots), and the number of microorganisms in the rhizosphere increased by more than three orders of magnitude. The induction of the rhizosphere environment and the intimidation of the petroleum changed the abundance and activity of the microorganisms. Dehydrogenase activity in the rhizosphere was 1.54 to 1.87 times the value in the unplanted soil, but catalase activity was 0.90 to 0.93 times the value in unplanted soil. The petroleum degradation rates in the rhizosphere were 2.33 to 3.19 times higher than in the unplanted soil. The effect of rhizosphere degradation clearly changed the hydrocarbon composition, increasing the degradation of alkane hydrocarbons with low and moderate carbon contents. The rhizosphere environment promoted degradation of the high-carbon-content hydrocarbons into low-carbon-content hydrocarbons. At the same time, the Pr/nC(17), Ph/nC(18), and Pr/Ph values increased by 0.99 and 2.69 units, and decreased by 1.25 units, respectively, compared with the undegraded oil. The plants also accelerated the isomerization of alkane hydrocarbons.
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Zhang ZZ, Liang YH, Quan C, Gao M, Xiao FL, Yang S, Zhang XJ, Zhou FS, Li W, Fang QY, Shen YJ, Du WH, Mu YZ, Sui WC, Zhou L. Three novel ATP2C1 mutations in Chinese patients with Hailey-Hailey disease. Br J Dermatol 2008; 158:831-3. [PMID: 18205868 DOI: 10.1111/j.1365-2133.2007.08400.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Shan CX, Liu Z, Zhang ZZ, Shen DZ, Hark SK. A Simple Route to Porous ZnO and ZnCdO Nanowires. J Phys Chem B 2006; 110:11176-9. [PMID: 16771380 DOI: 10.1021/jp0600514] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Porous ZnO nanowires were obtained in an inexpensive and simple way by thermally oxidizing ZnSe nanowires in air. The morphologies of the precursor and resulted nanowires are almost identical. X-ray diffraction and energy-dispersive X-ray spectroscopy reveal that the zinc blende ZnSe nanowires were transformed into wurtzite ZnO nanowires after oxidation. Transmission electron microscope measurements indicate that the ZnO nanowires are polycrystalline and are composed of nanoparticles and nanopores. ZnCdO nanowires, which were seldom reported previously, have also been prepared in this way. Just like the ZnO nanowires, the ZnCdO nanowires also show the porous structure. Photoluminescence studies on both ZnO and ZnCdO nanowires show intense near-band edge emissions at room temperature. The transition from one kind of nanowires to another by simple thermal oxidization described in this paper may be applicable to some other compound semiconductors and may open a practical route to yield nanowires.
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Lin F, Xue SL, Zhang ZZ, Zhang CQ, Kong ZX, Yao GQ, Tian DG, Zhu HL, Li CJ, Cao Y, Wei JB, Luo QY, Ma ZQ. Mapping QTL associated with resistance to Fusarium head blight in the Nanda2419 x Wangshuibai population. II: type I resistance. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2006; 109:1504-11. [PMID: 16328229 DOI: 10.1007/s00122-004-1772-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2004] [Accepted: 07/06/2004] [Indexed: 05/20/2023]
Abstract
Fusarium head blight (FHB) is a serious disease in wheat and barley affecting both yield and quality. To identify genes for resistance to infection, the RIL population derived from 'Nanda2419' x 'Wangshuibai' and the parents were evaluated for percentage of infected spikes (PIS) in four different environments. Using a 2,960 cM marker framework map constructed for this population, ten chromosome regions were detected for their association with type I resistance through interval mapping with Mapmaker/QTL, among which QTLs mapped in the intervals of Xwmc349--Xgwm149 on chromosome 4B, of Xwmc96--Xgwm304 on chromosome 5A and of Xgwm408--Xbarc140 on chromosome 5B were revealed in at least three environments and have Wangshuibai as the source of resistance alleles. Qfhi.nau-4B and Qfhi.nau-5A had larger effects and explained up to 17.5 and 27.0% of the phenotypic variance, respectively. To detect epistasis QTLs, two-locus interactions were examined by whole genome scan. Interactions of five locus pairs were found to have significant effects on type I resistance with the LOD score ranging 3.8-6.5 and four of them conferred resistance in parental phase. The one with the most significant effect was Xcfd42--Xgwm469 (6D)/Xwmc390-2--Xbd04 (2A) pair. No QTL x E interaction was detected for PIS. It was found that flowering time did not have significant effects on PIS in this population. Our studies indicated that Wangshuibai is useful for breeding for both type I and type II scab resistance and the markers associated with the QTLs could be used in marker-assisted selection and isolation of scab-resistance QTLs.
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Lin F, Xue SL, Zhang ZZ, Zhang CQ, Kong ZX, Yao GQ, Tian DG, Zhu HL, Li CJ, Cao Y, Wei JB, Luo QY, Ma ZQ. Mapping QTL associated with resistance to Fusarium head blight in the Nanda2419 x Wangshuibai population. II: type I resistance. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2006; 112:528-35. [PMID: 16328229 DOI: 10.1007/s00122-005-0156-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2005] [Accepted: 11/13/2005] [Indexed: 05/05/2023]
Abstract
Fusarium head blight (FHB) is a serious disease in wheat and barley affecting both yield and quality. To identify genes for resistance to infection, the RIL population derived from 'Nanda2419' x 'Wangshuibai' and the parents were evaluated for percentage of infected spikes (PIS) in four different environments. Using a 2,960 cM marker framework map constructed for this population, ten chromosome regions were detected for their association with type I resistance through interval mapping with Mapmaker/QTL, among which QTLs mapped in the intervals of Xwmc349--Xgwm149 on chromosome 4B, of Xwmc96--Xgwm304 on chromosome 5A and of Xgwm408--Xbarc140 on chromosome 5B were revealed in at least three environments and have Wangshuibai as the source of resistance alleles. Qfhi.nau-4B and Qfhi.nau-5A had larger effects and explained up to 17.5 and 27.0% of the phenotypic variance, respectively. To detect epistasis QTLs, two-locus interactions were examined by whole genome scan. Interactions of five locus pairs were found to have significant effects on type I resistance with the LOD score ranging 3.8-6.5 and four of them conferred resistance in parental phase. The one with the most significant effect was Xcfd42--Xgwm469 (6D)/Xwmc390-2--Xbd04 (2A) pair. No QTL x E interaction was detected for PIS. It was found that flowering time did not have significant effects on PIS in this population. Our studies indicated that Wangshuibai is useful for breeding for both type I and type II scab resistance and the markers associated with the QTLs could be used in marker-assisted selection and isolation of scab-resistance QTLs.
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Yan YQ, Chen ZP, Yang XM, Liu H, Zhang JX, Zhong W, Yao W, Zhao JK, Zhang ZZ, Hua JL, Li JS, Yu XQ, Wang FR. Attention to the hiding iodine deficiency in pregnant and lactating women after universal salt iodization: A multi-community study in China. J Endocrinol Invest 2005; 28:547-53. [PMID: 16117197 DOI: 10.1007/bf03347244] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Monitoring of iodine nutrition depends chiefly on the urinary iodine concentration in representative samples from the population. International groups have recommended school-age children as a convenient group for surveys, because of their accessibility and young age, but the relevance of this group to others, especially pregnant women, is not well established. OBJECTIVE The purpose was to compare different approaches to assessing iodine nutrition within communities, especially for pregnant and lactating women. DESIGN In an urban and a rural site from each of the 11 Chinese provinces, covering a wide geographic and socioeconomic range, we measured the iodine content of household salt and drinking water, the thyroid volume in school children, and the urinary iodine concentration in five population subsets; in some sites we also assessed iodine in breast milk and thyroid size in adult women. RESULTS The median urinary iodine concentrations for pregnant and lactating women were well below those of the schoolchildren from the same community in most study sites, the difference between medians, at overall level, being about 50 microg/l for the pregnant and 40 microg/l for the lactating, respectively. When ranked by median urinary iodine concentrations at overall level, the order of the groups was: all infants, schoolchildren, women of childbearing age, lactating women and pregnant women in both urban and rural sites. This relative distribution was constant among the study sites. From it, we derived a relationship to predict the median values for other groups, based on the data of schoolchildren. The median iodine content of salt was 30.9 ppm in urban sites and 31.3 ppm in rural sites, respectively, close to the nationally mandated 35 mg/kg. Water had low iodine content (3.7 microg/l) in both urban and rural sites except in a rural site from Tianjin. Ultrasonography showed that 6.5% of 1329 children in urban sites and 5.3% of 1431 children in rural sites had thyroid enlargement. Breast milk had a median iodine content of 135.9 microg/l in the urban and 157.5 microg/l in the rural. The goiter prevalence by palpation was low (2.0%) among all women examined (3367), but higher in pregnant women (2.7%) than in lactating women or other adult women. CONCLUSIONS An effective iodized salt program has brought iodine sufficiency to most of China, but pregnant women in some areas may still risk deficiency and need further supplements. We suggest other countries and international agencies pay more attention to pregnancy, where iodine deficiency has its worst consequences.
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Song HB, Zhang ZZ, Mak TC. 2,6-Bis(diphenylphosphino)pyridine-bridged hetero-polynuclear complexes consolidated by Fe-->M (M = Ag, Hg) dative bonding. Inorg Chem 2001; 40:5928-33. [PMID: 11681907 DOI: 10.1021/ic010426u] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The bridging phosphine ligand 2,6-bis(diphenylphosphino)pyridine (L) was used to synthesize a new, neutral organometallic ligand [Fe(CO)(4)](2)(micro-L) 1, which exhibits eclipsed and staggered conformations in two crystalline forms. This Fe,N,Fe-tridentate ligand reacts with silver perchlorate to form the hetero-trinuclear complex [[Fe(CO)(4)](2)Ag(micro-L)](ClO(4)) 2, in which the central silver(I) atom bridges a pair of iron(0) atoms at Fe-Ag distances of 2.627(3) and 2.652(3) A; the Fe-Ag-Fe angle is 170.98(9) degrees. The reaction of 1 with mercury(II) chloride gives [Fe(CO)(4)](2)Hg(2)Cl(4)(micro-L), 3. The ligand also reacts with mercury(II) acetate to form a hetero-octanuclear complex [[Fe(CO)(3)Hg](2)(micro-L)](2) 4 and a novel hetero-heptanuclear complex Fe(3)(CO)(8)Hg(4)(micro-L)(2)(MeCO(2))(2) 5. Complex 4 displays a square metallic core in which the iron and mercury atoms occupy the corners and the centers of the edges, respectively. The metal atoms in 5 are linked to form a kinky line with bends at the iron atoms.
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Song HB, Wang QM, Zhang ZZ, Mak TC. A novel luminescent copper(I) complex containing an acetylenediide-bridged, butterfly-shaped tetranuclear core. Chem Commun (Camb) 2001:1658-9. [PMID: 12240430 DOI: 10.1039/b102717b] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel luminescent acetylenediide-bridged tetranuclear copper(I) complex [Cu4(mu-Ph2Ppypz)4(mu 4-eta 1,eta 2-C identical to C)]-(ClO4)2 [Ph2Ppypz = 2-(diphenylphosphino-6-pyrazol-1-yl)pyridine] has been synthesized and structurally characterized by X-ray crystallography.
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Zhang ZZ, Liang XM, Zhang Q, Lu PZ. [Characterization and recognition key components in Astragalus membranaceus]. YAO XUE XUE BAO = ACTA PHARMACEUTICA SINICA 2001; 36:523-7. [PMID: 12585085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
AIM To separate, identify and quantify multi-components in complex traditional Chinese medicine (TCM) Astragalus membranaceus by unified analysis for systematic study of its relative contents. METHODS The analytical method was reverse-phase HPLC/photodiode array detector. Based on the comparison of UV spectra, software of UV database to assist recognition has been established. Key components have been found and recognized in two reference Astragalus membranaceus and three samples from different sources. With the unified analytical project, relative peak heights of key components were recognized and contrasted. RESULTS The water-soluble components can be separated by solvent system A, a gradient program with mobile phase of methanol-water. The liposoluble components can be separated with the solvent system B, a gradient program of mobile phase of 2-propanol-acetonitrile-water. UV detection wavelength was set at 202 nm and the flow rate was 1 mL.min-1 on a Hypersil ODS column. Twenty-nine components in the four Astragalus membranaceus were recognized using characteristic parameters of chromatography and UV spectroscopy. All of the 29 key components in two reference samples and three samples from different sources were shown in their chromatograms to be the same. The concentrations of some the key components in different samples were similar while those of the others were different. The chromatographic peaks of the reference Astragalus membranaceus and two samples were matched with each other. Many different fingerprints were found and differences were shown on their chromatograms. Not only there were differences among three samples from different source, but also there were differences in the two reference samples. CONCLUSION To find out the key components and recognize them are the basis of quantitative recognition and are very useful when standards are not available. The method of multi-component quantitative recognition in Astragalus membranaceus was developed. The method is convenient and reproducible. It can be widely used for the quality control of the Astragalus membranaceus.
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Zhang ZZ, Liang XM, Zhang Q, Lu PZ. [Study of unified analytical method of compatibleness for traditional Chinese medicines. II. The quantitation of curve fitting]. Se Pu 2001; 19:326-8. [PMID: 12545491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023] Open
Abstract
To introduce method of compatibleness analysis for traditional Chinese medicines, we select a part of the results from the study of astragalus root(A.), Chinese angelica root(Ca.) and their complex prescription (Danggui Buxue Tang, DBT) with an analytical mode of reversed-phase HPLC-photodiode array detector as an example of the quantitation of curve fitting. A new quantitative method, the concentration variation of components as the changing of single prescription dosage in complex prescriptions is discussed. This is the second part of the method of compatibleness analysis for traditional Chinese medicines.
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Zhang ZZ, Liang XM, Zhang Q, Lu PZ. [Study of unified analytical method of compatibleness for traditional Chinese medicines. I. Separation, recognition of characteristic components and fingerprint analysis for single and complex medicines]. Se Pu 2001; 19:239-42. [PMID: 12541806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023] Open
Abstract
It is difficult to separate, identify and quantify multi-component in complex traditional Chinese medicines (TCM). Many analytical methods for TCM have been established, but only a few components can be separated and quantified. For analyzing the multi-component and finding new method of compatibility analysis, a strategy--the multi-mode and multi-column chromatographic system and unified analytical method has been proposed by us. A part of the results from the study of astragalus root(A), Chinese angelica root(Ca.) and their complex prescription (Danggui Buxue Tang, DBT) with the analytical mode of reversed-phase HPLC/photodiode array detector as an example of the method for unified separation and recognition of characteristic components and fingerprint analysis was introduced. This is the first part of the results of compatibleness analysis for TCM.
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Zhang ZZ, Liang XM, Lu PZ, Zhang Q, Xue XY. [Recognition and quantitative contrast characteristic components for root of Chinese angelica]. Se Pu 2001; 19:157-60. [PMID: 12541663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023] Open
Abstract
A method of multi-component quantitative analysis in root of Chinese Angelica has been developed. The analytical mode was reversed-phase HPLC with photodiode array detector. Based on comparison of UV spectra, a software of UV spectra database to assist recognition has been established. The solvent system, a gradient program of mobile phase with 2-propanol/acetonitrile/water can separate a lot of liposoluble components in root of Chinese Angelica. UV detection wavelength was set at 202 nm and the flow rate was 1 mL/min on a Hypersil ODS column. Twenty-three components in two roots of Chinese Angelica were recognized using characteristic parameters of chromatography and UV spectroscopy. It is the base of quantitative contrast to recognize many characteristic components without standard components in root of Chinese Angelica. For two samples of root of Chinese Angelica both have 23 characteristic components and the concentrations of some components were similar and those of others were different. The method is convenient and reproducible. It can be used for the quality control of the root of Chinese Angelica without the use of standards.
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Zhang ZZ, Nirasawa S, Nakajima Y, Yoshida M, Kusakabe I, Hayashi K. Characterization of the pro-aminopeptidase from Aeromonas caviae T-64. Biosci Biotechnol Biochem 2001; 65:420-3. [PMID: 11302179 DOI: 10.1271/bbb.65.420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The pro-aminopeptidase from Aeromonas caviae T-64 (pro-apAC) had maximal activity at 60 degrees C and was more stable than mature apAC at temperature up to 65 degrees C for 1 hour. The pH stability of pro-apAC ranged from 4.0 to 8.0, which is broader than the range for the mature apAC. The kcat/Km of pro-apAC was 1.4% to 24% of that of mature apAC.
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Zhang Q, Zou HF, Chen XM, Wang HL, Ni JY, Zhang ZZ, Yao PJ. [The effect of temperature on the enantiomeric resolutions on albumin and beta-cyclodextrin chiral stationary phases]. Se Pu 2001; 19:9-12. [PMID: 12541837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023] Open
Abstract
The effect of column temperature on enantiomeric resolutions of tryptophan, warfarin and ketoprofen was investigated on bovine and human serum albumin (BSA and HSA) stationary phases, which were synthesized with s-triazine as the activator. It was observed that the entropy change made a great contribution to the separation of those enantiomers on albumin chiral stationary phases. The column temperature for the maximal resolution of tryptophan on the BSA stationary phase prepared by this method was about 35 degrees C, which was not 24 degrees C as reported for the BSA stationary phase synthesized with glutaric dialdehyde as the activator. This results may come from the different conformation of the immobilized BSA and HSA due to the different coupling methods used. On the other hand, it was indicated that the resolution of enantiomers on beta-CD chiral stationary phase was mainly contributed from the change of enthalpy, which means the resolution of chiral solutes on albumin and beta-CD stationary phases has different thermodynamic behaviors.
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Zhang ZZ, Nirasawa S, Nakajima Y, Yoshida M, Hayashi K. Function of the N-terminal propeptide of an aminopeptidase from Vibrio proteolyticus. Biochem J 2000; 350 Pt 3:671-6. [PMID: 10970778 PMCID: PMC1221296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
An aminopeptidase from Vibrio proteolyticus was translated as a preproprotein consisting of four domains: a signal peptide, an N-terminal propeptide, a mature region and a C-terminal propeptide. Protein expression and analysis of the activity results demonstrated that the N-terminal propeptide was essential to the formation of the active enzyme in Escherichia coli. Urea dissolution of inclusion bodies and dialysis indicated that the N-terminal propeptide could facilitate the correct folding of the enzyme in vitro. Using L-Leu-p-nitroanilide as the substrate, the kinetic parameters (k(cat) and K(m)) of the pro-aminopeptidase and processed aminopeptidases were analysed. The results suggested that the N-terminal propeptide inhibited enzyme activity of the mature region. In contrast, the C-terminal propeptide did not show evidence of forming an active enzyme, of correctly folding in vitro or of inhibiting the active region.
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Yamamoto K, Zhang ZZ, Kobayashi S. Cycloamylose (cyclodextrin) glucanotransferase degrades intact granules of potato raw starch. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2000; 48:962-966. [PMID: 10725182 DOI: 10.1021/jf9905018] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Cycloamylose (cyclodextrin) glucanotransferase (EC 2.4.1.19, CGTase) originated from Bacillus macerans degraded intact granules of potato raw starch and converted them into cyclodextrins (CDs). The degradation required sufficient stirring of starch-CGTase suspension. The morphology of the degraded starch granules was unique; that is, the inner part of the granules was observed by scanning electron microscope to be more susceptible to CGTase than the outer part. Effects of pH, temperature, starch concentration, and enzyme amount on CD production were studied.
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Nirasawa S, Nakajima Y, Zhang ZZ, Yoshida M, Hayashi K. Intramolecular chaperone and inhibitor activities of a propeptide from a bacterial zinc aminopeptidase. Biochem J 1999; 341 ( Pt 1):25-31. [PMID: 10377241 PMCID: PMC1220326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
An aminopeptidase from Aeromonas caviae T-64 was translated as a preproprotein consisting of three domains; a signal peptide (19 amino acid residues), an N-terminal propeptide (101 residues) and a mature region (273 residues). We demonstrated that a proteinase, which was isolated from the culture filtrate of A. caviae T-64, activated the recombinant pro-aminopeptidase by removal of the majority of the propeptide. Using L-Leu-p-nitroanilide as a substrate, the processed aminopeptidase showed a large increase in kcat when compared with the unprocessed enzyme, whereas the Km value remained relatively unchanged. The similar Km values for the pro-aminopeptidase and the mature aminopeptidase indicated that the N-terminal propeptide of the pro-aminopeptidase did not influence the formation of the enzyme-substrate complex, suggesting the absence of marked conformational changes in the active domain. In contrast, the marked difference in kcat suggests a significant decrease in the energy of one or more of the transition states of the enzyme-substrate reaction coordinate. Moreover, we showed that the activity of the urea-denatured pro-aminopeptidase could be recovered by dialysis, whereas the activity of the urea-denatured mature aminopeptidase, which lacked the propeptide, could not. Further to this, the propeptide-deleted aminopeptidase formed an inclusion body in the cytoplasmic space in Escherichia coli and was not secreted at all. These results suggested that the propeptide of the pro-aminopeptidase acted as an intramolecular chaperone that was involved with the correct folding of the enzyme in vitro and was required for extracellular secretion in E. coli.
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Kleanthous H, Myers GA, Georgakopoulos KM, Tibbitts TJ, Ingrassia JW, Gray HL, Ding R, Zhang ZZ, Lei W, Nichols R, Lee CK, Ermak TH, Monath TP. Rectal and intranasal immunizations with recombinant urease induce distinct local and serum immune responses in mice and protect against Helicobacter pylori infection. Infect Immun 1998; 66:2879-86. [PMID: 9596763 PMCID: PMC108285 DOI: 10.1128/iai.66.6.2879-2886.1998] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/1997] [Accepted: 03/12/1998] [Indexed: 02/07/2023] Open
Abstract
To determine the optimal inductive sites for immunization against Helicobacter pylori infection, the protective efficacy of recombinant urease (rUre) was assessed for mice given the vaccine by either the oral (p.o.), intranasal (i.n.), or rectal route. When mice were immunized with rUre (25 microg p.o. or rectally or 10 microg i.n.) plus heat-labile toxin from Escherichia coli as the mucosal adjuvant, all routes afforded protection against challenge with H. pylori, as indicated by a significant reduction in gastric urease activity (P < 0.0005) compared to that of sham-immunized controls. Quantitative H. pylori culture of stomach tissue demonstrated a >97% reduction in bacterial burden in mice immunized by all routes (P < 0.05). Induction of antiurease immunoglobulin A (IgA) levels in gastric luminal secretions after p.o. immunization was greater than after i.n. administration (means, 6.0 and 1.02 ng/ml, respectively) and was dependent upon challenge with H. pylori. However, immunization by the rectal route resulted in the generation of the highest levels of gastric antiurease IgA (mean, 40. 89 ng/ml), which was detectable prior to challenge with H. pylori. Immunohistochemical staining of stomach tissue for cells secreting urease-specific antibody and CD4(+) T cells showed levels of recruitment to be dependent upon challenge with H. pylori and equivalent for all routes. These results identify both the rectum and nasal passages as suitable inductive sites for urease immunization.
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72
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Zhang ZF, Zhang ZZ, Yu SZ, Marshall JR, Zielezny MA, Graham SL, Chen YX, Yang XZ. Geographical distribution of risk factors and incidence of invasive cervical cancer in south east China. J Epidemiol Community Health 1996; 50:104-5. [PMID: 8762364 PMCID: PMC1060214 DOI: 10.1136/jech.50.1.104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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73
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Ma GY, Zhang ZZ, Chen ZH. [Effect of protopine on rabbit platelet function]. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1994; 15:367-371. [PMID: 7801784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Protopine (Pro) inhibited dose-dependently rabbit platelet aggregation induced by ADP, arachidonic acid (AA), collagen, or aggregoserpentin of Trimeresurus mucrosquamatus venom (TMVA) in vitro. Their IC50 were 25.3, 30.5, 46.9, 33.4 mumol.L-1, respectively. Pro 10, 20 mg.kg-1 iv also inhibited the platelet aggregation induced by these inducers. The effects (maximal at 5 min) lasted 1 h. By using fluorophotometry and RIA, it was seen that Pro suppressed the release of 5-HT from platelets during aggregation induced by collagen, AA, or TMVM in vitro. Pro did not block the formation of thromboxane A2 during aggregation induced by AA and did not increase the content of cAMP in rabbit platelet, but increased the content of cGMP in rabbit platelets. The antiplatelet effect of Pro may be related to an increase cGMP in rabbit platelets and the suppression of the release of the active substances from platelets.
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74
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Zhang ZZ, Liu L. [Effects of ethanol and norepinephrine injected into nucleus hypoglossus on the genioglossal muscle activities]. SHENG LI XUE BAO : [ACTA PHYSIOLOGICA SINICA] 1993; 45:317-24. [PMID: 8296205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Integrated genioglossal and phrenic muscle activities were recorded on 87 urethane anesthetized, vagotomized rabbits to study the effect of ethanol and norepinephrine (NA) injected into nucleus hypoglossus on the potentiating effects of integrated genioglossal and phrenic muscle activities (PIMA). It was found that ethanol could inhibit PIMA of genioglossal muscle. Peak amplitude of PIMA (PAMP) was reduced with the latency of PIMA (LAT) prolonged and recovery time (RT) shortened. Norepinephrine facilitated PIMA, which could be blocked by Tolazolin. Local administration of ethanol (2 mol/L 1 microliter) to the caudal part of the 4th ventricle floor produced statistically significant reduction in genioglossal muscle activities (P < 0.01) in resting respiration. The present results suggest that ethanol exerts inhibitory effect on genioglossal muscle activity which may be associated with the inhibition of nucleus hypoglossus per se or caudal part of the 4th ventricle floor. The excitatory activity of genioglossal muscle may be mediated by noradrenergic receptors in the nucleus hypoglossus.
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75
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Zhang ZZ. [Transplantation of thin pedicle skin flap: a new method in the treatment of skin defect of hand (a report of 54 cases)]. ZHONGHUA ZHENG XING SHAO SHANG WAI KE ZA ZHI = ZHONGHUA ZHENG XING SHAO SHANG WAIKF [I.E. WAIKE] ZAZHI = CHINESE JOURNAL OF PLASTIC SURGERY AND BURNS 1992; 8:123-4, 165. [PMID: 1446287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We used the transplantation of the thin pedicle skin flap to repair the skin defect on the hand and claw hand due to scar contracture in 54 patients. The results were improved. The size of the skin flaps was 16-8 cm x 6-4 cm. The average time of division of the pedicle was 10.5 days. In comparison with the free skin graft with a preserved subcutaneous vascular network, the whole thickness free skin graft, the random pattern skin flap (local flap, fascio cutaneous flap and traditional skin flap), the axial pattern skin flap (including island skin flap and myocutaneous flap), showed that the thin pedicle skin flap was superior over them. The indications, blood circulation and the points for attention in the operation were discussed.
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Lin B, Zhang ZZ, Hu B. Multifractal characterization of random resistor and random superconductor networks. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1991; 44:960-967. [PMID: 9906044 DOI: 10.1103/physreva.44.960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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77
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Huang YH, Zhang ZZ, Jiang JX. [Relaxant effects of protopine on smooth muscles]. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1991; 12:16-9. [PMID: 1683090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The relaxant effects of protopine (Pro) on smooth muscles were studied by recording isotonic contraction and radioimmunoassay. Pro relaxed the contraction of rabbit thoracic aorta, mesenteric artery, portal vein and guinea pig ileum and taenia colon induced by high K+ (70 mmol.L-1). Pro also inhibited the contraction of rabbit thoracic aorta, mesenteric artery, portal vein induced by NE (0.3 mumol.L-1) and guinea pig taenia colon induced by BaCl2 (1 mmol.L-1). Pro inhibited the intracellular Ca2+ release, but did not inhibit Ca2+ influx induced by NE. These results suggested that the smooth muscle relaxant mechanism of action of Pro may be the inhibition of intracellular Ca2+ release.
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Zhang ZZ, Zhong SZ, Sun B, Ho GT. Blood supply of the flexor digital tendon in the hand and its clinical significance. Surg Radiol Anat 1990; 12:113-7. [PMID: 2396176 DOI: 10.1007/bf01623335] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
An anatomical study on the blood sources and vascularity of the flexor digital tendon was conducted in the upper extremities of fresh cadavers by means of arterial injection and meticulous dissection of the transparent tendon under the microscope. According to whether or not synovial membrane surrounded the tendon, the flexor digital tendon can be divided into 2 regions: non-synovial and synovial. The major intrinsic blood supply of the digital tendon was in the form of longitudinal vascular bundles, while the transverse anastomotic branches were short and sparse. The non-synovial region of the tendon was covered by paratenon and the vascular distribution of this region was uniform. In the synovial sheath, the blood vessels distributed only on the dorsal side, while the volar side was devoid of vessels. The profundus and superficialis tendons had an avascular zone at the proximal interphalangeal and metacarpophalangeal joints respectively. It was considered that the difference of the vascular architecture might be related to the mechanical force to which the tendon was subjected. The nutrition of tendon was discussed and the selection of tendon graft at operation was suggested.
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Zhang ZZ, Fan CS, Huang AH. [A study on the quality of fruits of Citrus aurantium L. (zhishi and Zhiqiao) produced in Jiangxi]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1989; 14:520-2, 573. [PMID: 2511867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Through a study on the quality of different commercial fruits of Citrus aurantium (Zhishi and Zhiqiao) produced in Jiangxi, it has been found that the quality of Eyan Zhishi is good and Jiang Zhishi and Jiang Zhiqiao are the best varieties.
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80
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Zhang ZZ. [Applied anatomic observation on the synovial membrane of the digital sheath]. ZHONGHUA WAI KE ZA ZHI [CHINESE JOURNAL OF SURGERY] 1989; 27:209-10, 253. [PMID: 2805988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The synovial membrane of various parts of flexor tendons and sheaths was examined with the aid of light and scanning electron microscopes. The results show that on the compressed sites such as the volar aspect of the tendon and the inner aspect of the pulley, no continuous synovial cell layer and blood vessel existed, indicating that these areas may not closely related to the secretion of synovial fluid. Alternatively, on the areas of lesser burden such as the reflexion of the synovial capsule, the short vincula and the small cul-de-sacs at either end of each pulley, the synovial membrane became thicker and the number of synovial cells greatly increased, and there were exuberant capillary networks underneath the synovial membrane. All these add up to a concept that these areas are closely associated with the secretion of synovial fluid, and should certainly be preserved during operation.
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81
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Zhang ZZ, Zeng XG, Guo JT, Sun ML, Zhang XL. [In vitro transformation of Syrian hamster embryo cells by four chemicals]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1989; 20:96-8. [PMID: 2793154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In this paper, the early passage diploid Syrian hamster embryo (SHE) cells were used as the source of target. Four chemicals were appraised in SHE transformation test to determine whether they were carcinogens or not. They were (1) 2-benzoyl-hydrazono-1,3-diethiolane(BHD) (technical product); (2) isoprothiolane (pure product); (3) isoprothiolane (technical product); (4) benzene-abstracts from coal smoke of coke oven (benzene-abstracts). The results showed that morphological transformation was not observed when cells were not treated or treated with dimethyl sulfoxide, BHD, pure isoprothiolane and the technical product of isoprothiolane. The highest concentration had considerable cytotoxicity. In the groups of positive control (1.0 microgram/ml 3-methyl-cholanthrene, 10.0 micrograms/ml benzo (a) pyrene) and benzene-abstracts, we could observe colonies with random or criss-cross orientation and dense piling-up of cells. According to well known positive criteria, the benzene-abstracts can induce SHE cells morphological transformation. The other three chemicals can not induce SHE cells transformation.
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Li HL, Su Q, Xiang JM, Zhang ZZ, Mo YQ. [Antispasmodic effect of acetagastrodine on vascular smooth muscle]. YAO XUE XUE BAO = ACTA PHARMACEUTICA SINICA 1986; 21:539-41. [PMID: 3811945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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83
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Zhang ZZ. [Experimental study on "18 against compatibilities" of Chinese traditional medicine--acute toxicity of Aconitum carmichaeli and Pinellia ternate]. ZHONG YAO TONG BAO (BEIJING, CHINA : 1981) 1983; 8:33-4. [PMID: 6226427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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84
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Chen ZH, Zhang ZX, Wang MD, Wang DC, Zhang ZZ. [Spasmolytic effects of isocorydine on isolated vascular strips]. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1982; 3:240-2. [PMID: 6219539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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85
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Han F, Liu RC, Zhong TL, Zhang ZZ. Echinococcosis alveolaris in Qinghai Province. Chin Med J (Engl) 1981; 94:391-5. [PMID: 6788482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
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