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Search Results: 1 - 10 of 80940 matches for " Baosheng Liu "
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Thermo-Mechanical Treatment on Microstructure and Mechanical Properties of Mg-5.0Sn-1.0Mn-0.4Zr Alloy  [PDF]
Xiaoping Luo, Daqing Fang, Baosheng Liu
Advances in Materials Physics and Chemistry (AMPC) , 2018, DOI: 10.4236/ampc.2018.81004
Abstract: The mechanical properties and microstructure of an as-cast Mg-5.0Sn-1.0Mn-0.4Zr alloy were investigated during thermo mechanical treatments consisting of hot extrusion, rolling, and ageing at 200°C. The results indicate that only Mg2Sn phases formed in the Mg matrix, Mn and Zr do not cause the formation of any new phases. The average grain size, tensile strength and elongation were 22 μm, 285 MPa, and 14.5%, respectively, after extrusion + rolling + ageing treatment (ERA). The mechanical properties of ERA alloys with a peak hardness of 81 HV and 6.7% are improved compared with those of EA (extrusion + ageing treatment) samples; these changes are attributed to grain refinement and solid solution strengthening, age hardening, and precipitation strengthening.
Highly sensitive tunable diode laser absorption spectroscopy of CO2 around 1.53 μm
Yong LIU,Baosheng LI,Yufeng ZHAI,An WANG
Optica Applicata , 2006,
Abstract: The absolute absorption spectrum intensities of carbon dioxide sample have been recorded with a tunable diode laser spectrometer in the spectral range 6506–6520 cm–1, which is suitable for the in situ sensing of carbon dioxide in the lower stratosphere, and were studied using a commercial telecommunication-type diode laser. The intensity of the weakest line we detected in this experiment is 9.116×10–27 cm–1/(molecule·cm–2) at a pressure of 0.35 torr, and the corresponding absorption is 1.96×10–6 with SNR of 2.67.
Investigation on the Competition Interaction of Synthetic Food Colorants and Ciprofloxacin Hydrochloride with Bovine Serum Albumin by Fluorescence Spectroscopy
Baosheng Liu,Chao Yang,Jing Wang,Chunli Xue,Yunkai Lü
Journal of Thermodynamics , 2011, DOI: 10.1155/2011/137531
Abstract: The effects of synthetic food colorants like tartrazine (TTZ), sunset yellow (SY), and erythrosine (ETS) on the binding reaction between ciprofloxacin hydrochloride (CPFX) and bovine serum albumin (BSA) were investigated by fluorescence spectroscopy in the aqueous solution of pH = 7.40. Results showed that CPFX caused the fluorescence quenching of BSA through a static quenching procedure and the primary binding site was located at subdomain IIA of BSA (site I). According to the calculated thermodynamic parameters, it confirmed that CPFX bound to BSA by electrostatic interaction. In addition, the colorants affected the formation of BSA-CPFX complex. This resulted in an increase of the free, biological active fraction of CPFX. The binding distance of BSA-CPFX systems was evaluated according to Förster's theory. Results suggested that the binding distance were increased in the presence of synthetic food colorants.
Interaction of Avelox with Bovine Serum Albumin and Effect of the Coexistent Drugs on the Reaction
Baosheng Liu,Chao Yang,Xiaona Yan,Jing Wang,Yunkai Lv
International Journal of Analytical Chemistry , 2012, DOI: 10.1155/2012/408057
Abstract: The interaction between Avelox and bovine serum albumin (BSA) was investigated at different temperatures by fluorescence spectroscopy. Results showed that Avelox could quench the intrinsic fluorescence of BSA strongly, and the quenching mechanism was a static quenching process with F?rester spectroscopy energy transfer. The electrostatic force played an important role on the conjugation reaction between BSA and Avelox. The order of magnitude of binding constants ( ) was 104, and the number of binding site ( ) in the binary system was approximately equal to 1. The binding distance ( ) was less than 3?nm and the primary binding site for Avelox was located in subdomain IIA of BSA. Synchronous fluorescence spectra clearly revealed that the microenvironment of amino acid residues and the conformation of BSA were changed during the binding reaction. In addition, the effect of some antibiotics on the binding constant of Avelox with BSA was also studied. 1. Introduction Most drugs are able to bind to plasma protein when they entrance in blood plasma system of organism, and serum albumin is the most abundant protein in blood plasma and serves as a depot protein and transport protein for numerous endogenous and exogenous compounds [1]. Generally speaking, drugs could bind with serum albumin mostly through the formation of noncovalent complexes reversibly. The drug-protein complex can be regarded as a form of drug in the biology temporary storage, it can effectively avoid drug elimination from metabolism so quickly that it can maintain the total concentration and effective concentrations of blood medicine in plasma. In addition, binding of drugs to plasma proteins controls their free, active concentrations and provides a reservoir for a longer action, the binding of drugs is responsible for the protective role of albumin. Therefore, interaction of a drug with, and competition for, the binding sites on plasma proteins might strongly affect its distribution, elimination, as well as its pharmacodynamics and toxic properties [2]. Competition between two drugs for their binding to plasma protein can strongly affect the drug disposition of both drugs, with possible serious physiological consequences. Binding parameters are indeed fundamental factors in determining the overall pharmacological activity of a drug, and in this context the determination of the binding parameters of drugs to albumin has become essential to understand their pharmacokinetic, pharmacodynamic, and toxicological profile. Avelox is a new generation of fluoroquinolone antibacterial agents, which is
Designer Amphiphilic Short Peptides Enhance Thermal Stability of Isolated Photosystem-I
Baosheng Ge,Feng Yang,Daoyong Yu,Shuang Liu,Hai Xu
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0010233
Abstract: Stability of membrane protein is crucial during protein purification and crystallization as well as in the fabrication of protein-based devices. Several recent studies have examined how various surfactants can stabilize membrane proteins out of their native membrane environment. However, there is still no single surfactant that can be universally employed for all membrane proteins. Because of the lack of knowledge on the interaction between surfactants and membrane proteins, the choice of a surfactant for a specific membrane protein remains purely empirical. Here we report that a group of short amphiphilic peptides improve the thermal stability of the multi-domain protein complex photosystem-I (PS-I) in aqueous solution and that the peptide surfactants have obvious advantages over other commonly used alkyl chain based surfactants. Of all the short peptides studied, Ac-I5K2-CONH2 (I5K2) showed the best stabilizing effect by enhancing the melting temperature of PS-I from 48.0°C to 53.0°C at concentration of 0.65 mM and extending the half life of isolated PS-I significantly. AFM experiments showed that PS-I/I5K2/Triton X-100 formed large and stable vesicles and thus provide interfacial environment mimicking that of native membranes, which may partly explain why I5K2 enhanced the thermal stability of PS-I. Hydrophobic and hydrophilic group length of IxKy had an important influence on the stabilization of PS-I. Our results showed that longer hydrophobic group was more effective in stabilizing PS-I. These simple short peptides therefore exhibit significant potential for applications in membrane protein studies.
Investigation on the Competition Interaction of Synthetic Food Colorants and Ciprofloxacin Hydrochloride with Bovine Serum Albumin by Fluorescence Spectroscopy
Baosheng Liu,Chao Yang,Jing Wang,Chunli Xue,Yunkai Lü
Journal of Thermodynamics , 2011, DOI: 10.1155/2011/137531
Abstract: The effects of synthetic food colorants like tartrazine (TTZ), sunset yellow (SY), and erythrosine (ETS) on the binding reaction between ciprofloxacin hydrochloride (CPFX) and bovine serum albumin (BSA) were investigated by fluorescence spectroscopy in the aqueous solution of pH = 7.40. Results showed that CPFX caused the fluorescence quenching of BSA through a static quenching procedure and the primary binding site was located at subdomain IIA of BSA (site I). According to the calculated thermodynamic parameters, it confirmed that CPFX bound to BSA by electrostatic interaction. In addition, the colorants affected the formation of BSA-CPFX complex. This resulted in an increase of the free, biological active fraction of CPFX. The binding distance of BSA-CPFX systems was evaluated according to F?rster's theory. Results suggested that the binding distance were increased in the presence of synthetic food colorants. 1. Introduction When drugs are absorbed, they enter the circulatory system and bind to serum albumin extensively and reversibly [1]. The effectiveness of drugs depends on their combination abilities. Binding of drugs to serum albumin has significance in pharmacology, since it controls their free concentrations and, as a consequence to the degree and time of action in the body, affects duration and intensity of their effects [2–4]. In other words, binding to serum albumin will significantly affect the distribution, metabolism, and excretion of drugs. Drugs are subjected to the influences of many factors in vivo, among which dietary habits cannot be ignored. Interactions between diet and drugs reflect the change of pharmacodynamics and the incompatibilities. There are various researches about the influences of sugar, wine, and tea on the efficacy of a medicine [5, 6]. However, researches about the effects of synthetic food colorants on medication have not been reported. Ciprofloxacin hydrochloride (CPFX, the structure is shown in Figure 1) which belongs to the third-generation synthetics of quinolones shows striking potency against enteric Gram-negative bacilli, lesser activity against nonenteric Gram-negative bacilli and staphylococci, and generally marginal activity against streptococci and anaerobes [7, 8]. It has received much attention because of its broad-spectrum pharmacological activities and extensive biological effects. Tartrazine (TTZ), sunset yellow (SY), and erythrosine (ETS, structures are shown in Figure 1) are common synthetic food colorants, which are widely used in food like drinks, candies, and in sugar-coated capsules for
Polyploid evolution in Oryza officinalis complex of the genus Oryza
Baosheng Wang, Zhuoya Ding, Wei Liu, Jin Pan, Changbao Li, Song Ge, Daming Zhang
BMC Evolutionary Biology , 2009, DOI: 10.1186/1471-2148-9-250
Abstract: Tracing the C-genome evolutionary history in Oryza officinalis complex, this study revealed the genomic relationships, polyploid forming and diverging times, and diploidization process, based on phylogeny, molecular-clock analyses and fluorescent in situ hybridization using genome-specific probes. Results showed that C-genome split with B-genome at ca. 4.8 Mya, followed by a series of speciation of C-genome diploids (ca. 1.8-0.9 Mya), which then partook in successive polyploidization events, forming CCDD tetraploids in ca. 0.9 Mya, and stepwise forming BBCC tetraploids between ca. 0.3-0.6 Mya. Inter-genomic translocations between B- and C-genomes were identified in BBCC tetraploid, O. punctata. Distinct FISH (fluorescent in situ hybridization) patterns among three CCDD species were visualized by C-genome-specific probes. B-genome was modified before forming the BBCC tetraploid, O. malampuzhaensis.C-genome, shared by all polyploid species in the complex, had experienced different evolutionary history particularly after polyploidization, e.g., inter-genomic exchange in BBCC and genomic invasion in CCDD tetraploids. It diverged from B-genome at 4.8 Mya, then participated in the tetraploid formation spanning from 0.9 to 0.3 Mya, and spread into tropics of the disjunct continents by transcontinentally long-distance dispersal, instead of vicariance, as proposed by this study, given that the continental splitting was much earlier than the C-genome species radiation. We also find reliable evidence indicated that an extinct BB diploid species in Asia was presumptively the direct genomic donor of their sympatric tetraploids.Polyploidization is a prominent process in the evolution of high plants. Between 50% and 70% of angiosperm species were identified as polyploids by intensive screening, while recent studies estimated that up to 100% of angiosperms underwent genome duplication at least once in their evolutionary history [1,2]. The commonity of polyploidy suggests a potentia
PCR-based generation of shRNA libraries from cDNAs
Cheng Du, Baosheng Ge, Zhongfeng Liu, Kai Fu, Wing C Chan, Timothy W McKeithan
BMC Biotechnology , 2006, DOI: 10.1186/1472-6750-6-28
Abstract: We report here an improved method for constructing genome-wide shRNA libraries enzymatically. The method includes steps of cDNA fragmentation and endonuclease MmeI digestion to generate 19-bp fragments, capping the 19-bp cDNA fragments with a hairpin oligonucleotide, and amplification of the hairpin structures by PCR. The PCR step converts hairpins into double-stranded DNAs that contain head-to-head cDNA fragments that can be cloned into a vector downstream of a Pol III promoter.This method can readily be used to generate shRNA libraries from a small amount of mRNA and thus can be used to create cell- or tissue-specific libraries.RNA interference (RNAi) provides a powerful tool for silencing gene expression. Large-scale phenotypic or pathway-driven screens of siRNA libraries may help to identify novel genes that may be targets for therapy in cancer and other diseases. Two different methods have been used to construct genome-wide siRNA libraries. One is to chemically synthesize oligonucleotides based on siRNA design algorithms (for reviews, see [1,2]). Typically, the oligonucleotides are synthesized in the form of double-stranded DNA molecules containing short hairpin RNA (shRNA) templates and are cloned into a Pol III-driven expression vector. Libraries constructed with this method and targeting more than 10,000 different human genes have been successfully used for screening [3,4]. The other method is to convert collections of cDNAs into shRNA templates. Three groups have developed protocols to produce genome-wide shRNA libraries [5-7]. These protocols share several common features, and all "measure" the appropriate length of the hairpin using the type IIS restriction endonuclease MmeI, which cuts 20/18 nt from its recognition site. The common steps, with minor variations, include (1) generating random cDNA fragments; (2) ligating the cDNA fragments with a double-stranded oligonucleotide that contains an MmeI site; (3) restriction digestion with MmeI; (4) ligating a
Degradation of PVA by supercritical water oxidation
聚乙烯醇在超临界水氧化中降解

Wang Shiqin,Ma Yugang,Liu Baosheng,
王世琴
,马玉刚,刘宝生

环境工程学报 , 2012,
Abstract: The degradation of polyvinyl alcohol(PVA)using H2O2 as the oxidant in a batch tube reactor was studied.The influences of temperature,pressure,time and excess oxygen on the COD removal rate were investigated and the process conditions were optimized through orthogonal tests.The chief liquid products were characterized by GC/MS.The results showed that PVA could be degraded completely in supercritical water.When the reaction temperature was 440℃,the pressure was 28 MPa,oxygen excess was 4,and the reaction time was 40 min,the COD removal rate could achieve 99.03% and COD of the effluent was 89.09 mg/L.The liquid products were alkene,enol,mellow,organic acids,straight chain alkane,and so on.
Factors affecting the electrical conductivity of rice hull coke
稻壳焦炭导电特性的影响因素

XIAO Gang,JIN Baosheng,LIU Jichi,WANG Qiang,
肖刚
,金保升,刘继驰,王强

环境科学学报 , 2009,
Abstract: 为开发生物质焦炭电磁屏蔽材料,研究了各种因素对稻壳焦炭导电特性的影响规律.利用自制的高温炭化试验装置,考察了炭化终温、升温速率、终温下的保留时间、粒径大小、催化剂种类及配比等因素对焦炭电阻率的影响规律.研究结果表明:炭化终温对稻壳焦炭电阻率影响较大,特别是在1000℃以下,提高炭化终温可将焦炭电阻率从106 Ω·cm以上降低到2Ω·cm左右;而当炭化终温从1000℃提高到1400℃时,电阻率仅从2Ω·cm左右降低到1.5Ω·cm左右.提高升温速率会降低焦炭产率,但对电阻率的影响不大.延长炭化终温时间对降低电阻率有一定作用,但当物料粒径较小时其作用几乎可以忽略.Fe2O3和NiO可作为炭化催化剂降低焦炭电阻率,两者催化效果相当,稻壳与催化剂的最佳质量配比在50:1左右.当炭化终温>1000℃、升温速率为20℃·min-1、保留时间为30min、稻壳粒径为0.1~0.3mm、稻壳:催化剂=50:1时,所获焦炭电阻率为0.2~1.0Ω·cm.
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