Showing papers by "Southwest University published in 2006"

Comparative genomics and evolution of the HSP90 family of genes across all kingdoms of organisms

Abstract: HSP90 proteins are essential molecular chaperones involved in signal transduction, cell cycle control, stress management, and folding, degradation, and transport of proteins. HSP90 proteins have been found in a variety of organisms suggesting that they are ancient and conserved. In this study we investigate the nuclear genomes of 32 species across all kingdoms of organisms, and all sequences available in GenBank, and address the diversity, evolution, gene structure, conservation and nomenclature of the HSP90 family of genes across all organisms. Twelve new genes and a new type HSP90C2 were identified. The chromosomal location, exon splicing, and prediction of whether they are functional copies were documented, as well as the amino acid length and molecular mass of their polypeptides. The conserved regions across all protein sequences, and signature sequences in each subfamily were determined, and a standardized nomenclature system for this gene family is presented. The proeukaryote HSP90 homologue, HTPG, exists in most Bacteria species but not in Archaea, and it evolved into three lineages (Groups A, B and C) via two gene duplication events. None of the organellar-localized HSP90s were derived from endosymbionts of early eukaryotes. Mitochondrial TRAP and endoplasmic reticulum HSP90B separately originated from the ancestors of HTPG Group A in Firmicutes-like organisms very early in the formation of the eukaryotic cell. TRAP is monophyletic and present in all Animalia and some Protista species, while HSP90B is paraphyletic and present in all eukaryotes with the exception of some Fungi species, which appear to have lost it. Both HSP90C (chloroplast HSP90C1 and location-undetermined SP90C2) and cytosolic HSP90A are monophyletic, and originated from HSP90B by independent gene duplications. HSP90C exists only in Plantae, and was duplicated into HSP90C1 and HSP90C2 isoforms in higher plants. HSP90A occurs across all eukaryotes, and duplicated into HSP90AA and HSP90AB in vertebrates. Diplomonadida was identified as the most basal organism in the eukaryote lineage. The present study presents the first comparative genomic study and evolutionary analysis of the HSP90 family of genes across all kingdoms of organisms. HSP90 family members underwent multiple duplications and also subsequent losses during their evolution. This study established an overall framework of information for the family of genes, which may facilitate and stimulate the study of this gene family across all organisms.

Magnetic core-shell Fe3O4@Ag nanoparticles coated carbon paste interface for studies of carcinoembryonic antigen in clinical immunoassay.

Abstract: This study demonstrates a novel approach toward development of advanced immunosensors based on chemically functionalized core−shell Fe3O4@Ag magnetic nanoparticles, and the preparation, characterization, and measurement of relevant properties of the immunosensor useful for the detection of carcinoembryonic antigen (CEA) in clinical immunoassay. The immunosensor based on the combination of a magnetic nanocore and an Ag metallic shell shows good adsorption properties for the attachment of the CEA antibody selective to CEA. The core−shell nanostructure presents good magnetic properties to facilitate and modulate the way it was integrated into a carbon paste. Under optimal conditions, the resulting composite presents good electrochemical response for the detection of CEA, and allows detection of CEA at a concentration as low as 0.5 ng·mL-1. Importantly, the proposed methodology could be extended to the detection of other antigens or biocompounds.

Visual Detection of Sudan Dyes Based on the Plasmon Resonance Light Scattering Signals of Silver Nanoparticles

Abstract: A visual light scattering detection method of Sudan dyes is reported in food products based on the formation of silver nanoparticles (NPs) . Sudan dyes including I, II, III and IV have reducibility due to the nitrogen−nitrogen double bond and phenol group in their molecular structure, and a redox reaction could occur with AgNO3. Owing to the formation of silver NPs as a result of the redox reaction, color changes could be observed by eye from the red of Sudan to the brown of silver NPs, resulting in strong plasmon resonance light scattering (PRLS) signals characterized at 452 nm, which could be measured using a common spectrofluorometer. It was found that the PRLS intensities were proportional to the dye concentrations over the range of 0.2−2.4 μM Sudan I, 0.1−2.4 μM Sudan II, 0.1−2.4 μM Sudan III, and 0.2−3.0 μM Sudan IV, with the corresponding limits of determination (3σ) of 3.2, 3.0, 3.2, and 2.9 nM, respectively. Using hot chili as a model sample, detection could be made with the recovery of 90.8−103....

Overexpression of an Arabidopsis magnesium transport gene, AtMGT1, in Nicotiana benthamiana confers Al tolerance

Abstract: Aluminium (Al) toxicity is the most important limiting factor for crop production in acid soil environments worldwide. In some plant species, application of magnesium (Mg 2+ ) can alleviate Al toxicity. However, it remains unknown whether overexpression of magnesium transport proteins can improve Al tolerance. Here, the role ofAtMGT1, a member of the Arabidopsis magnesium transport family involved in Mg 2+ transport, played in Al tolerance in higher plants was investigated. Expression of 35S::AtMGT1 led to various phenotypic alterations in Nicotiana benthamiana plants. Transgenic plants harbouring 35S::AtMGT1 exhibited tolerance to Mg 2+ deficiency. Element assay showed that the contents of Mg, Mn, and Fe in 35S::AtMGT1 plants increased compared with wild-type plants. Root growth experiment revealed that 100 mM AlCl3 caused a reduction in root elongation by 47% in transgenic lines, whereas root growth in wild-type plants was inhibited completely. Upon Al treatment, representative transgenic lines also showed a much lower callose deposition, an indicator of increased Al tolerance, than wild-type plants. Taken together, the results have demonstrated that overexpression of ATMGT1 encoding a magnesium transport protein can improve tolerance to Al in higher plants.

Direct electrochemistry of horseradish peroxidase immobilized on gold colloid/cysteine/nafion-modified platinum disk electrode

Abstract: Direct electron transfer process of immobilized horseradish peroxidase (HRP) on a gold colloid-cysteine-nafion membrane, and its application as a biosensor were investigated by using electrochemical methods. The electrochemical characteristics of the biosensor were studied by cyclic voltammetry, linear sweep voltammetry and chronoamperometry. The modified process was characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The sensor displayed an excellent electrocatalytic response to the reduction of H 2 O 2 without the aid of an electron transfer mediator. Analytical parameters such as pH and temperature were also studied. Linear calibration for H 2 O 2 was obtained in the range 3.50 × 10 −7 to 5.87 × 10 −3 M under the optimized conditions. The sensor was highly sensitive to H 2 O 2 with a detection limit of 1.05 × 10 −7 M ( S / N = 3), and the sensor achieved 95% of the steady-state current within 10 s. The sensor exhibited high sensitivity, selectivity and stability.

A new adaptive well-chosen inertia weight strategy to automatically harmonize global and local search ability in particle swarm optimization

Abstract: The global search ability and local search ability are two highly important components of particle swarm optimizer, which are inconsistent each other in many cases, we proposed a novel inertia weight strategy that can adaptively select a preferable inertia weight decline curve for a particle swarm form curves of the constructed function according to the fitness value of swarm, and to automatically harmonize global and local search ability, quicken convergence speed, avoid premature problem, and obtain global optimum Experimental results on several benchmark functions show that the algorithm can rapidly converge at very high quality solutions

The Challenges for the Adoption of M-Health

Abstract: The potential benefit of mobile and wireless information technology for healthcare service delivery, improving patient safety and reducing cost is increasingly recognized and emphasized. To contributing to the knowledge about critical factors determining the success of mobile health (m-Health) solutions, this study researched the driving force for the advancement of m-health solutions. The current advancement of m-health was reviewed. The challenges for developing and deploying m-health applications were addressed. The paper concluded in suggesting the most critical factor for the success of m-health. The method used for the study was literature research, market scan and analysis.

Genes encoding small heat shock proteins of the silkworm, Bombyx mori

Abstract: Small heat shock protein (sHSP) is a family of ubiquitous polypeptides involved in a variety of physiological phenomena. From the silkworm, Bombyx mori, we isolated and sequenced the following cDNAs encoding sHSPs: shsp19.9, shsp20.1, shsp20.4, shsp20.8, shsp21.4, and shsp23.7. shsp21.4 was nearly twice as large in size as other shsps. The deduced amino acid sequence of sHSP21.4 was similar to that of Drosophila melanogaster CG14207-PA. Other sHSPs were highly similar to each other and, in a phylogenetic tree, formed a cluster including Plodia interpunctella αCP25. It was speculated that shsp21.4 has at least one intron in genome while other shsps do not. The transcripts of all shsps were subtle, but were constitutively detected in various tissues. Heat shock triggered a substantial increase in the transcripts other than shsp21.4. The B. mori sHSPs are perhaps classified into at least two groups: sHSP21.4 and others.

Novel molecular and mechanical properties of egg case silk from wasp spider, Argiope bruennichi.

Abstract: Araneoid spiders use specialized abdominal glands to produce up to seven different protein-based silks/glues that have various mechanical properties. To date, the fibroin sequences encoding egg case fibers have not been fully determined. To gain further understanding of a recently reported spider silk protein gene family, several novel strategies were utilized in this study to isolate two full-length cDNAs of egg case silk proteins, cylindrical silk protein 1 (CySp1, 9.1 kb) and cylindrical silk protein 2 (CySp2, 9.8 kb), from the wasp spider, Argiope bruennichi. Northern blotting analysis demonstrated that CySp1 and CySp2 are selectively expressed in the cylindrical glands. The amino acid composition of raw egg case silk was closely consistent with the deduced amino acid composition based on the sequences of CySp1 and CySp2, which supports the assertion that CySp1 and CySp2 represent two major components of egg case silk. CySp1 and CySp2 are primarily composed of remarkable homogeneous assemble repeats that are 180 residues in length and consist of several complex subrepeats, and they contain highly homologous C-termini and markedly different N-termini. Our results suggest a possible link between CySp1 and CySp2. In addition, comparisons of stress/strain curves for dragline and egg case silk from Argiope bruennichi showed obvious differences in ultimate strength and extensibility, and similarities in toughness.

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Abstract: Based on a previous longitudinal study, multiple methods were used to investigate the development of a Chinese gifted child, with the emphasis on her college stage. Results showed that she had grown up into a healthy, rounded, and stable gifted young adult, and had developed compound and specialized talents. Some factors were discussed to explore the pattern and condition of her development.

Effects of Cry1Ab Toxin on Propylea japonica (Thunberg) (Coleoptera: Coccinellidae) Through Its Prey, Nilaparvata lugens Stål (Homoptera: Delphacidae), Feeding on Transgenic Bt Rice

Abstract: Laboratory feeding experiments using rice plants containing a synthetic cry1Ab gene derived from Bacillus thuringiensis Berliner (Bt) were carried out to study the effects of Bt rice-fed prey on the predator Propylea japonica (Thunberg). Plants were obtained from two homozygous transgenic Bt-cry1Ab expressing rice lines, Kemingdao 1 (KMD1) and Kemingdao 2 (KMD2), and their untransformed parental variety Xiushui 11 (XS11). The herbivorous prey species tested was the brown planthopper, Nilaparvata lugens Stal, one of most serious insect pests of rice and not targeted by KMD1 or KMD2. The concentrations of Cry1Ab toxin expressed in KMD1 and KMD2 plants and that of the toxin transferred to N. lugens feeding on these plants were determined by enzyme immunosorbent assay technique. Development parameters of P. japonica reared on KMD1- or KMD2-fed N. lugens were assessed in the laboratory. The results showed that the concentration of Cry1Ab in rice leaves and stems significantly increased from the bootin...

Amperometric Hydrogen Peroxide Biosensor Based on the Immobilization of Horseradish Peroxidase (HRP) on the Layer‐by‐Layer Assembly Films of Gold Colloidal Nanoparticles and Toluidine Blue

Abstract: The precursor film was first formed on the Au electrode surface based on the self-assembly of L-cysteine and the adsorption of gold colloidal nanoparticles (nano-Au). Layer-by-layer (LBL) assembly films of toluidine blue (TB) and nano-Au were fabricated by alternately immersing the electrode with precursor film into the solution of toluidine blue and gold colloid. Cyclic voltammetry (CV) and quartz crystal microbalance (QCM) were adopted to monitor the regular growth of {TB/Au} bilayer films. The successful assembly of {TB/Au}n films brings a new strategy for electrochemical devices to construct layer-by-layer assembly films of nanomaterials and low molecular weight materials. In this article, {TB/Au}n films were used as model films to fabricate a mediated H2O2 biosensor based on horseradish peroxidase, which responded rapidly to H2O2 in the linear range from 1.5×10−7 mol/L to 8.6×10−3 mol/L with a detection limit of 7.0×10−8 mol/L. Morphologies of the final assembly films were characterized with scanning probe microscopy (SPM).

Four-wing attractors: from pseudo to real

Abstract: Some basic dynamical behaviors and the compound structure of a new four-dimensional autonomous chaotic system with cubic nonlinearities are investigated. A four-wing chaotic attractor is observed n...

Ligand‐functionalized core/shell Ag@Au nanoparticles label‐free amperometric immun‐biosensor

Abstract: A novel label-free electrochemical immunoassay based on core/shell Ag@Au nanoparticles monolayer as sensing interface has been developed for probing IgG. Several coupling techniques, such as Ag nanoparticles, Au nanoparticles, and the core/shell Ag@Au nanoparticles with L-Cysteine (Cys) cross-linking, were investigated for the determination of IgG and a very good result was obtained with the core/shell Ag@Au nanoparticles coupling. With the core/shell Ag@Au nanoparticles coupling method, the effects of the incubation time and pH on amperometric responses of the immunoassay were studied. The strong attachment of the cross-linked complex to the core/shell Ag@Au nanoparticles surface resulted in an excellent storage lifetime of 33 days. A dynamic concentration range of 2.3 to 960 ng/mL with a detection limit of 10 ng/mL was observed. Analytical results of 30 human serum samples obtained using the developing technique are in satisfactory agreement with those given by ELISA. In addition, it presents some superior advantages over the traditional sandwich format in that the analyzing performances are direct, rapid, and simple without multiple separation and labeling steps. © 2006 Wiley Periodicals, Inc.

Amperometric enzyme immunosensors based on layer-by-layer assembly of gold nanoparticles and thionine on Nafion modified electrode surface for α-1-fetoprotein determinations

Abstract: A novel amperometric enzyme immunosensor with amplified sensitivity has been developed for the detection of α-1-fetoprotein (AFP) based on layer-by-layer (LBL) assembly of gold nanoparticles (nano-Au) and thionine (Thi) on Nafion (Nf) modified electrode surface by electrostatic adsorption. The stepwise layer-by-layer adsorption interface morphology was further characterized by means of electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The enzyme, horseradish peroxidase (HRP), was employed to block the possible remaining active sites of the nano-Au monolayer, avoid the non-specific adsorption instead of bovine serum albumin (BSA) and amplify the response of the antigen–antibody reaction. The performance and factors influencing the performance of the resulting immunosensors were studied in detail. Tests performed with this immunosensor showed good linearity and specificity when it was evaluated on several standard serum samples and the working range for the system was 1 to 250 ng/ml with a detection limit of 0.56 ng/ml. In addition, the prepared immunosensor could be regenerated 8 times with 4 M urea solution. When the immunosensor was stored at 4 °C and measured intermittently (every 3–5 days), no apparent change was found over 3 months, it yielded a 6.5% R.S.D.

Stories We Love by Conceptions of Love Among Couples From the People's Republic of China and the United States

Abstract: This research examines conceptions of love among dating and married couples from China and the United States. Sixty-one dating and 81 married American couples and 46 dating and 94 married Chinese couples completed portions of Sternberg’s (1998) Love Stories Scale and measures of demographics, stress, and relationship satisfaction. Factor analyses revealed several love story components (objectification-threat, devotion-caring, pragmatism, pornography) common to both cultures, albeit there were subtle differences in their specific elements. Culturally unique components included “love as war” and “love as fairy tale” for the Americans and “love as current tending” and "incomprehensibility of lover” for the Chinese. Devotion– care was the strongest predictor of relationship satisfaction within each culture, independent of demographics and perceived stress. In sum, the research suggests that although Chinese and American views of love overlap somewhat, subtle cultural differences and culturally unique metaphors are also apparent.