Behavioral plasticity is the most striking trait in locust phase transition. However, the genetic basis for behavioral plasticity in locusts is largely unknown. To unravel the molecular mechanisms underlying the behavioral phase change in the migratory locust Locusta migratoria, the gene expression patterns over the time courses of solitarization and gregarization were compared by oligonucleotide microarray analysis.
View Article and Find Full Text PDFBiomaterials
November 2010
Block co-polymers PCTBVs (M(n) of 36,300-65,300 g/mol, T(m) of 39-40 and 142 degrees C) containing hyperbranched three-arm poly(epsilon-caprolactone) (PCL) as switching segment and microbial polyester PHBV as crystallizable hard segment were designed as biodegradable shape-memory polymer (SMP) for fast self-expandable stent and synthesized in 96% yield by the reaction of three-arm PCL-triol (M(n) of 4200 g/mol, T(m) of 47 degrees C) with methylene diphenyl 4,4'-diisocyanate isocynate (MDI) to form the hyperbrached MDI-linked PCL (PTCM; M(n) of 25,400 g/mol and a T(m) of 38 degrees C), followed by further polymerization with PHBV-diol (M(n) of 2200 g/mol, T(m) of 137 and 148 degrees C). The polymers were characterized by (1)H NMR, GPC, DSC, tensile test, and cyclic thermomechanical tensile test. PCTBVs showed desired thermal properties, mechanical properties, and ductile nature.
View Article and Find Full Text PDFBackground: Pancreas transplantation is the only established treatment to achieve long-term normoglycemia and insulin independence in patients with insulin-dependent diabetes mellitus. However, many complications both during and post-transplantation have limited the progress of pancreas transplantation. Mice are the widely used laboratory animals that have been used to establish pancreas transplant models.
View Article and Find Full Text PDFThermodynamic studies on the interactions between intercalator-neomycin conjugates and a DNA polynucleotide triplex [poly(dA).2poly(dT)] were conducted. To draw a complete picture of such interactions, naphthalene diimide-neomycin (3) and anthraquinone-neomycin (4) conjugates were synthesized and used together with two other analogues, previously synthesized pyrene-neomycin (1) and BQQ-neomycin (2) conjugates, in our investigations.
View Article and Find Full Text PDFWei Sheng Wu Xue Bao
February 2010
Objective: Most of microbial extracellular polysaccharide (EPS) has the favorable functionality and peculiarity, but little research has been done about EPS that were synthesized by yeasts. Screening of EPS-producing yeasts and studies on the optimal culture composition are the main purpose of this study.
Methods: Yeasts were obtained by screening from natural samples using spread-plate method, Yield of EPS synthesized by yeasts was estimated by phenolsulfate acid method, Based on 5.
Guang Pu Xue Yu Guang Pu Fen Xi
January 2010
Preprocess method of multiplicative scatter correction (MSC) was used to reject noises in the original spectra produced by the environmental physical factor effectively, then the principal components of near-infrared spectroscopy were calculated by nonlinear iterative partial least squares (NIPALS) before building the back propagation artificial neural networks method (BP-ANN), and the numbers of principal components were calculated by the method of cross validation. The calculated principal components were used as the inputs of the artificial neural networks model, and the artificial neural networks model was used to find the relation between chlorophyll in winter wheat and reflective spectrum, which can predict the content of chlorophyll in winter wheat. The correlation coefficient (r) of calibration set was 0.
View Article and Find Full Text PDFIt has been demonstrated that stromal cell precursors exist in human umbilical cord blood. After being cultured in vitro, these cells are called human umbilical cord blood-derived stromal cells (hUCBDSCs). However, the role of hUCBDSCs in hematopoiesis is still unclear.
View Article and Find Full Text PDFPurpose: There is mounting evidence demonstrating that stromal cell derived factor-1 (SDF-1) plays an important role in homing of hematopoietic progenitor cells to bone marrow. This study was aimed to assess whether bone marrow mesenchymal stem cells overexpressing exogenous SDF-1 could synergistically promote the homing of CD34(+) (Cluster of Differentiation [CD]) cells to bone marrow of lethally irradiated severe combined immunodeficiency (SCID) mice.
Methods: Human SDF-1 complementary Deoxyribonucleic acid (cDNA) was transfected into bone marrow-derived mesenchymal stem cells with recombinant lentiviral vector.
Enzyme-catalyzed polycondensation for the synthesis of block copolymers was reported for the first time. Thermoplastic block copolyesters containing poly[(R)-3-hydroxybutyrate] (PHB) and poly[(R)-3-hydroxyoctanoate] (PHO) blocks were enzymatically prepared by one- or two-step lipase-catalyzed polycondensation. Novozym 435-catalyzed reaction of PHB-diol (M(n) of 3100 g/mol, GPC), PHO-diol (M(n) of 3200 g/mol, GPC), and divinyl adipate gave block poly(HB-co-HO) (M(n) of 9800 g/mol, GPC) with randomly arranged blocks in 55% yield.
View Article and Find Full Text PDFMicroRNAs (miRNAs) are endogenous RNAs of about 20-25 nucleotides that play important roles in gene regulation. Based on miRNA backbones, artificial miRNAs, amiRNAs, can be constructed and expressed exogenously. AmiRNAs can function as natural miRNAs or siRNAs.
View Article and Find Full Text PDFAim: To explore immunological properties of human umbilical cord blood-derived stromal cells (hUCBDSC) and their effect on xenogeneic immune cells in vitro.
Methods: Immunological phenotype of freshly isolated and cryopreserved hUCBDSCs was evaluated by flow cytometry. Xenogeneic splenic T-cells were stimulated by phytohemaglutinin A (PHA) or dendritic cells in the absence or presence of hUCBDSCs.
Eight accessory proteins have been identified in severe acute respiratory syndrome-associated coronavirus (SARS-CoV). They are believed to play roles in the viral life cycle and may contribute to the pathogenesis and virulence. ORF9b as one of these accessory proteins is located in subgenomic mRNA9 and encodes a 98 amino acid protein.
View Article and Find Full Text PDFZhongguo Shi Yan Xue Ye Xue Za Zhi
April 2009
In order to investigate the effect of stromal cell derived factor-1 (SDF-1)/CXCR4 on the proliferation of megakaryocytic line-HEL cells co-cultured with human umbilical cord blood-derived stromal cells (hUCBSCs) and to further elucidate the mechanism of SDF-1/CXCR4-mediated functions, the HEL cells were co-cultured with hUCBSCs or human bone marrow stromal cells (hBMSCs), the suspended HEL was used as control. The concentrations of SDF-1 in supernatant of hUCBSCs and hBMSCs were detected by ELISA assay. The expression of CXCR4 membrane-bound protein of HEL cells was detected by laser confocal scanning microscopy and flow cytometry, and the expression of CXCR4 mRNA was detected by RT-PCR.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
April 2009
In this paper, we got the implementation of the electronic neuron based on the Morris-Lecar model, and use the circuit to analysis the bifurcation of the Morris-Lecor model. Based on the results of the bifurcation analysis, we get bursting neurons by introducing a slow driving current. Furthermore, based on the implementation of a single electronic neuron, the electronic neurons are coupled through inhibiting chemical synapses which is one of the most important connections.
View Article and Find Full Text PDFZhongguo Shi Yan Xue Ye Xue Za Zhi
December 2008
In order to study the influence of different gelatin concentrations, and lymphocyte isolation liquid on primary culture of umbilical cord blood-derived adhesive cells (hCBACs), the red blood cells of umbilical cord blood was separated by 3% and 6 % gelatin for detecting the effectiveness of sedimentation, then the adhesion rate at 48 hours, the day of initial expansion and the rate of culture success were detected for hCBACs cultured with CD34(+) cells after the mononuclear cells were separated by 6% gelatin followed by Ficoll and Percoll, and the morphological characteristics and growth status were observed by invert microscopy. Cytochemistry stain for nonspecific esterase stain (NSE), peroxidase (POX), periodic acid Schiff reaction (PAS) and alkali phosphatase (ALP) and immunocytochemistry labeling for CD31, CD45, CD68 and fibronectin (Fn) were detected. The results showed that 6 % gelatin was better than that 3% gelatin for red blood sedimentation.
View Article and Find Full Text PDFIn this paper, an integrated MEMS gyroscope array method composed of two levels of optimal filtering was designed to improve the accuracy of gyroscopes. In the firstlevel filtering, several identical gyroscopes were combined through Kalman filtering into a single effective device, whose performance could surpass that of any individual sensor. The key of the performance improving lies in the optimal estimation of the random noise sources such as rate random walk and angular random walk for compensating the measurement values.
View Article and Find Full Text PDFTwo oxyethylene/oxybutylene block copolymers (E(40)B(79) and E(47)B(62)), which exhibit body-centered cubic sphere (bcc) and hexagonally packed cylindrical (hex) melt morphologies in bulk, respectively, were blended with nanoclay of montmorillonite (MMT). The effects of MMT on the morphology and crystallization of E(40)B(79) and E(47)B(62) were studied with small-angle x-ray scattering, wide-angle x-ray diffraction, and differential scanning calorimeter. It is found that the E block in the block copolymers can intercalate into the galleries of MMT, leading to a larger layer spacing than that of neat MMT.
View Article and Find Full Text PDFZhongguo Shi Yan Xue Ye Xue Za Zhi
February 2008
This study was aimed to investigate the expression of SDF-1 mRNA in SDF-1 cDNA-modified human bone marrow mesenchymal stem cells (hBMSCs) before and after transfection. The hBMSCs were isolated, cultured and identified, the SDF-1-pIRES2-EGFP eukaryotic expressing vector was constructed, and then the hBMSCs were transfected with the vector encapsulated by lipofectamine 2000. The transfection efficiency was measured by observing the expression of green fluorescence protein and detecting the mRNA by RT-PCR.
View Article and Find Full Text PDFThere are four LhcII genes of Dunaliella salina have been submitted to the database of GenBank. However, little is known about Lhca genes of this green alga, although this knowledge might be available to study the composition and phylogenesis of Lhc gene family. Recently, one Lhca gene was been cloned from the green alga D.
View Article and Find Full Text PDFDunaliella salina is a useful model for studying the respective roles of each LHCII protein at the molecular level in extreme environmental conditions. However, information about the LhcII genes in D. salina is very limited.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
October 2006
The supported Wacker catalysts were pretreated with two different methods. Then copper and palladium were determined by inductively coupled plasma atomic emission spectrometry(ICP-AES). The results showed that the best pretreatment method is burning-acid dissolving.
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