Showing papers by "Qian Zhang published in 2009"
TL;DR: The results provide a foundation for future research of OsHsfs function and no significant correlation, however, was found between the heat-shock responses of genes and their cis-elements.
Abstract: Heat stress transcription factors (Hsfs) are the central regulators of defense response to heat stress. We identified a total of 25 rice Hsf genes by genome-wide analysis of rice (Oryza sativa L.) genome, including the subspecies of O. japonica and O. indica. Proteins encoded by OsHsfs were divided into three classes according to their structures. Digital Northern analysis showed that OsHsfs were expressed constitutively. The expressions of these OsHsfs in response to heat stress and oxidative stress differed among the members of the gene family. Promoter analysis identified a number of stress-related cis-elements in the promoter regions of these OsHsfs. No significant correlation, however, was found between the heat-shock responses of genes and their cis-elements. Overall, our results provide a foundation for future research of OsHsfs function.
56 citations
24 Feb 2009
TL;DR: In this article, a high ZT of approximately 1.5 has been obtained in both Bi2Te3-Sb2Te 3 and GeTe-AgSbTe2 nanocomposites.
Abstract: Bulk thermoelectric materials are of interest for commercial application in both power generation and Peltier refrigeration. Various synthesis approaches have been developed by our group for high performance bulk thermoelectric materials, such as solvo- or hydrothermal synthesis for nanopowders, hot-pressing, and spark plasma sintering for nanostructured bulk materials, and rapid solidification for metal silicides. In this article we report some of our recent results in the development of high ZT thermoelectric materials, including Bi2Te3-Sb2Te3 nanocomposites and CoSb3 micro/nanocomposites prepared by a powder blending route, and GeTe-AgSbTe2 and Mg2Si-Mg2Sn nanocomposites prepared by an in situ route. The results show various possibilities for improved microstructures and therefore enhanced properties of bulk thermoelectric materials through optimization of the preparation processing based on simple synthesis routes. A high ZT of approximately 1.5 has been obtained in both Bi2Te3-Sb2Te3 and GeTe-AgSbTe2 nanocomposites. Further ZT enhancement of the materials should be possible through the control of the nanopowder morphology during synthesis and the hindering of␣grain growth during sintering, as well as through the optimization of composition and doping.
37 citations
TL;DR: In this article, the magnetic properties and magnetocaloric effect of the ferrimagnetic compounds Gd(4)Co(3) and (Gd(0.9)Dy (0.1))(4, Co(3), have been studied and shown that the successive magnetic transitions could enlarge the temperature interval, which makes this type of material meaningful for magnetic refrigeration in wider temperature regions than conventional materials.
Abstract: Magnetic properties and magnetocaloric effect of the ferrimagnetic compounds Gd(4)Co(3) and (Gd(0.9)Dy(0.1))(4)Co(3) have been studied. In Gd(4)Co(3), two successive magnetic-entropy changes occur due to a spin-reorientation transition at T(SR)=163 K and a ferrimagnetic-magnetic ordering transition at T(C)=220 K. For a field change from 0 to 5 T, -Delta S(M)(max) at T(C) is 5.74 J/kg K, the full width at half maximum (delta T(FWHM)) of the -Delta S(M) versus T curve has a high value of 131 K, and the refrigerant capacity is as high as 575 J/kg. T(C) can easily be tuned by Dy substitution for Gd and the magnetic-entropy change is increased simultaneously. -Delta S(M)(max) of (Gd(0.9)Dy(0.1))(4)Co(3) at T(C)=145 K for the same field change has increased to 8.47 J/kg K. Our studies suggest that the successive magnetic transitions could enlarge the temperature interval, which makes this type of material meaningful for magnetic refrigeration in wider temperature regions than conventional materials.
31 citations
Journal Article•
TL;DR: Strain 08H101032 was a potential new species of the genus Fransicella with a typical characteristic of L-cysteine growth stimulating activity, distinguishingly to Legionella with L-cycline growth dependent activity.
Abstract: OBJECTIVE To identify and characterize the strain 08H101032 was isolated from air condition systems in the routine investigations of Legionella in Guangzhou, China, in 2008. METHODS We adopted several phenotypic and genotypical methods, such as the growth status on various media, morphological, physical and biochemical characteristics, animal test, antibiotic susceptivities, PCR identification, sequence analysis of 16S RNA and RNA polymerase beta-subunit (ropB) gene etc, to determinate the phylogenetic position and outline the basic biological characteristics. RESULTS Strain 08H101032 was Gram-negative with polymorphic short rods or coccobacillus; with no flagella; devoid of spores; well growth on buffered charcoal yeast extraction (BCYE) agar and BCYE supplemented with glycine (3 g/L), polymyxin B sulfate (80000 iu/L), vancomycin (1 mg/L) and cycloheximide (80 mg/L) (GVPC medium) within 2 days, but delayed growth on ordinary sheep blood agar untill 5 - 7 days; catalase positive; oxidase negative; no reduction of nitrate; no hydrolysis of urea; delayed fermention of glucose to produce acid; which was primarily considered as Legionella. It was lastly identified to the genus Fransicella, characterized by a variety of biochemical and molecular phylogenetic tests, which shared the highest similarities to F. Philomiragia with 95.3% to 16S rRNA gene of 1377 oligo nucleotides and 87.3% to ropB gene of 367 oligo nucleotides (GenBank accession number: FJ591095, FJ939309). Growth were observed after a treatment for 10 minutes with the KCl-HCl buffer of pH 2.2, 20 degrees C, and at 25 degrees C, 37 degrees C (optimum 25 degrees C - 28 degrees C), but not at 42 degrees C. The cells had capsule-like construction by transmission electron microscopy, however no virulence found to mice. CONCLUSIONS Strain 08H101032 was a potential new species of the genus Fransicella with a typical characteristic of L-cysteine growth stimulating activity, distinguishingly to Legionella with L-cysteine growth dependent activity.
22 citations
TL;DR: Water-withholding for 5 to 7 weeks and subsequent re-watering were made on potted plants of two epiphytic and two terrestrial fern species, which were collected from a seasonal tropical rainforest and had been grown in a screenhouse with 5 % irradiance for 4 months.
Abstract: Water-withholding for 5 to 7 weeks and subsequent re-watering were made on potted plants of two epiphytic (E) and two terrestrial (T) fern species, which were collected from a seasonal tropical rainforest and had been grown in a screenhouse with 5 % irradiance for 4 months. During the water stress, the two E species completely closed stomata when frond relative water content (RWC) reached about 70 % with fairly constant maximum photochemistry efficiency (Fv/Fm), while the two T species kept partial stomata opening until RWC reached 45 % and reduction in Fv/Fm at the late stage. Also, chlorophyll content as indicated by a spectral reflectance index was gradually reduced in three species. Physiological recovery was completed after 3-d re-watering for the E species, which was more rapid than for the T species. The gas exchange measurements and regression analyses indicated higher photosynthetic water use efficiency in the E species than in the T species.
21 citations
TL;DR: The analysis of the transgenic P-985/UTRΔ/GUS plants showed that both the exon1 sequence and the leading intron within the 5′ UTR region were responsible for the regulation of gene expression.
Abstract: Genome-wide analyses have identified a set of TIR-NBS-encoding genes in plants. However, the molecular mechanism underlying the expression of these genes is still unknown. In this study, we presented a TIR-NBS-encoding gene, PtDrl02, that displayed a low level of tissue-specific expression in a triploid white poplar [(Populus tomentosa × P. bolleana) × P. tomentosa], and analyzed the effects of the 5′ untranslated region (UTR) on gene expression. The 5′ UTR sequence repressed the reporter activity of β-glucuronidase (GUS) gene under PtDrl02 promoter by 113.5-fold with a staining ratio of 2.97% in the transgenic tobacco plants. Quantitative RT-PCR assays revealed that the 5′ UTR sequence decreased the transcript level of the GUS reporter gene by 13.3-fold, implying a regulatory role of 5′ UTR in transcription and/or mRNA destabilization. The comparison of GUS activity with the transcript abundance indicated that the 5′ UTR sequence decreased the translation efficiency of target gene by 88.3%. Additionally, the analysis of the transgenic P-985/UTRΔ/GUS plants showed that both the exon1 sequence and the leading intron within the 5′ UTR region were responsible for the regulation of gene expression. Our results suggested a negative effect of the 5′ UTR of PtDrl02 gene on gene expression.
17 citations
TL;DR: It is concluded that the taurine-supplemented diet has a beneficial effect on immune responses and performance in growing Japanese quail.
15 citations
TL;DR: In this article, the electrical conductivity of open-cell Fe-Ni alloy foams over a range of relative density from 2.3% to 12.8% is investigated.
10 citations
TL;DR: In this paper, a facile and practical method for the stereospecific synthesis of α-oxoketene O,S-acetals in water has been developed.
Abstract: A facile and practical method for the stereospecific synthesis ofa-oxoketene O,S-acetals in water has been developed. Catalyzed by tetrabutylammonium bromide at room temperature, the one-pot reaction of various p-dicarbonyl compounds, 2-bromoethanol, and carbon disulfide, in the presence of potassium carbonate, leads to the corresponding α-oxoketene O,S-acetals stereospecifically in good to excellent yields. The catalyst in the aqueous phase can be recycled after the separation of the organic products.
2 citations
TL;DR: In order to investigate the protein features of an NBS gene (PtDRG01, EF157840), the full-length open reading frame was fused into a prokaryotic expression vector pGEX-KG and IPTG treatment successfully induced the expression of a fusion protein of about 79 kD, which was consistent with the predicted value.
Abstract: In order to investigate the protein features of an NBS gene (PtDRG01, EF157840) isolated from Populus tomentosa Carr., the full-length open reading frame was fused into a prokaryotic expression vector pGEX-KG. PCR analysis and double endonuclease digestion showed that the recombinant vector was successfully constructed and transferred into an expression host E. coli strain XA90. It was indicated by SDS-PAGE analysis that IPTG treatment successfully induced the expression of a fusion protein of about 79 kD, which was consistent with the predicted value. In addition, the prokaryotic expression system was also optimized. The result suggests that 1 mmol/L IPTG treatment for 4 h at 37°C was most effective, and the product was predominately soluble and not extra-cellular secreting. Moreover, the fusion protein was purified with an affinity chromatography column using Glutathione Sepharose 4B. This work will lay a foundation for further studies on biological functions of the PtDRG01 gene.
1 citations
TL;DR: In this article, a facile and practical method for the stereospecific synthesis of a-oxoketene O,S-acetals in water has been developed.
Abstract: SYNTHESIS 2009, No. 5, pp 0824–0828xx.xx.2009 Advanced online publication: 27.01.2009 DOI: 10.1055/s-0028-1083333; Art ID: F20608SS © Georg Thieme Verlag Stuttgart · New York Abstract: A facile and practical method for the stereospecific synthesis of a-oxoketene O,S-acetals in water has been developed. Catalyzed by tetrabutylammonium bromide at room temperature, the one-pot reaction of various b-dicarbonyl compounds, 2-bromoethanol, and carbon disulfide, in the presence of potassium carbonate, leads to the corresponding a-oxoketene O,S-acetals stereospecifically in good to excellent yields. The catalyst in the aqueous phase can be recycled after the separation of the organic products.