Reaction Processes of the Titanium Matrix Composites Fabricated from Ti-Al-B2O3 System

Titanium matrix composites reinforced with a-Al2O3 and TiB2 particles were fabricated by in situ synthesis from a Ti-Al-B2O3 system. The reaction processes and microstructure were analyzed by using differential scanning calorimetry（DSC）, scanning electron microscopy（SEM） and X-ray diffraction（XRD）. The results showed that the reactions in the Ti-Al-B2O3 system can occur spontaneously and consist of three steps： 1） 15 Al ＋ 7B2O3 → 7α-Al2O3 ＋ AlB12 ＋ 2B; 2） 14 B ＋ 2Al → AlB12 ＋ AlB2 and 3） 7Ti ＋ AlB（12） ＋ AlB2 → 7TiB2 ＋ 2Al. The final reinforcements were composed of α-Al2O3 and TiB2 particles, which were uniformly distributed in the titanium matrix.

Identification of differentially expressed genes in dorsal root ganglion in early diabetic rats

Objective To screen and identify differentially expressed genes in the dorsal root ganglion （DRG） in early experimental diabetic rats. Methods Diabetic model rats were induced by single intraperitoneal injection of streptozotocin （STZ）. At the second week after STZ injection, the sensory nerve conduction velocities （SNCV） of sciatic nerve were measured as an indicator of neuropathy. The technique of silver-staining mRNA differential display polymerase chain reaction （DD-PCR） was used to detect the levels of differentially expressed genes in rat DRG. The cDNA fragments that displayed differentially were identified by reverse-hybridization, cloned and sequenced subsequently, and then confirmed by Northern blot. Results The SNCV in the diabetic model group [n = 9, （45.25±10.38） m/s] reduced obviously compared with the control group [n = 8, （60.10± 11.92） m/s] （P 〈 0.05）. Seven distinct cDNA clones, one was up-regulated gene and the others were downregulated ones, were isolated by silver-staining mRNA differential display method and confirmed by Northern blot. According to the results of sequence alignment with GenBank data, majority of the clones had no significant sequence similarity to previously reported genes except only one that showed high homology to 6-pyruvoyl-tetrahydropterin synthase mRNA （accession No., BC059140）, which had not been reported to relate to diabetic neuropathy. Conclusion These differentially expressed genes in the diabetic DRG may contribute to the pathogenesis of diabetic peripheral neuropathy.

Stereodynamics of O（^3P）＋H2 at Scattering Energies of 0.5, 0.75, and 1.0 eV

Quasiclassical trajectory calculation of the title reaction O（^3P）＋H2→OH＋H at three different scattering energies of 0.5, 0.75, and 1.0 eV on the lowest electronic potential energy surface 1^3A＂ has been done. Distribution P（θr） of polar angles between the relative velocityk of the reactant and rotational angular momentum vector j＇ of the product, distribution P（φr） of the azimuthal as well as dihedral angles correlating k-k＇-j＇, 3-dimensional distri-bution, and polarization-dependent differential cross sections （PDDCSs）dependent upon the scattering angle of the product molecule OH between the relative velocity k of the reactant and k＇ of the product at different scattering energies of 0.5, 0.75, and 1.0 eV are presented and discussed.

Novel flutamide regulated genes in the rat veritral prostate： differential modulation of their expression by castration and flutamide treatments

Aim： To identify flutamide regulated genes in the rat ventral prostate. Methods： Total RNA from ventral prostates of control and flutamide treated rats were isolated. Differentially expressed transcripts were identified using differential display reverse transcriptase polymerase chain reaction. The effect of castration on the expression of flutamideregulated transcripts was studied. Results： We have identified β2-microglobulin, cytoplasmic FMR1 interacting protein 2 and pumilio 1 as flutamide induced and spermine binding protein and ribophorin Ⅱ as flutamide repressed targets in the rat ventral prostate. Although flutamide treatment caused an induction of pumilio 1 rnRNA, castration had no effect. Conclusion： Castration and flutamide treatments exert differential effects on gene expression. Flutamide might also have direct AR independent effects, which might have implications in the emergence of androgen independent prostate cancer and the failure of flutamide therapy.

VALUE OF POLYMERASE CHAIN REACTION ASSAY IN DIAGNOSIS OF INTESTINAL TUBERCULOSIS AND DIFFERENTIATION FROM CROHN'S DISEASE

It is difficult to make a precise diagnosis of intestinal tuberculosis and to differentiate it from Crohn's disease. For evaluating Polymerase Chain Reaction (PCR) assay in these two aspects, 36 specimens of intestinal tuberculosis from surgical resections and endoscopic biopsies and 26 Crohn's disease samples were subjected to PCR assay. 21 specimens of normal colon tissue surrounding cancer were used as the control. Oligonucleotides derived from the IS 6110 sequence, which is repeated in M. tuberculosis chromosome and highly specific for the M. tuberculosis complex, were used as a primer. The amplified PCR products were detected by examination of ethidium-bromide-stained polyacrylamide gels. The specificity of PCR products was confirmed by digestion with Sal 1 restrictive endonuclease and southern blot hybridization using digoxigenin-labeled probe. The results showed that the M. tuberculosis DNA was identified in 27 / 36 intestinal tuberculosis, but none of 26 Crohn's disease. Acid fast bacilli were only found in 16 / 36 intestinal tuberculosis. In conclusion, as a rapid, sensitive, and specific pathogenic method in diagnosis of intestinal tuberculosis, PCR assay has been developed in this study, and is considered valuable in the differentiation between intestinal tuberculosis and Crohn's disease.

Down-Regulation of OsGRF1 Gene in Rice rhdl Mutant Results in Reduced Heading Date

Abstract: A rice mutant with reduced heading date (designated rhd1) found in a transgenic line of cultivar Teqing 2 (Oryza sativa L. ssp. indica) was used to identify the genes related to rice heading and thereby to study its molecular mechanism. Genetic analysis showed that rhd1 was a dominant mutation and did not result from T-DNA insertion. By using the differential display polymerase chain reaction (DD-PCR) technique, differential gene expression between rhd1 and Teqing 2 was compared and a rhd1-down-regulated c DNA fragment was identified. Sequence analysis showed that this fragment shared 99% similarity to the OsGRF1 (O. sativa growth-regulating factor 1) gene. The OsGRF1 gene encodes a putative transcription factor, which contains two conserved regions: the QLQ (Gln, Leu, Gln) and WRC (Trp, Arg, Cys) domains. Southern analysis indicates that OsGRF1 may be encoded by single copy gene in the rice genome. RNA interference results revealed that transgenic lines with reduced OsGRF1 transcript displayed delayed growth and development, developed small leaves, and had delayed heading. The extent of the phenotypes developed was well-correlated with the OsGRF1 gene transcript. Our results clearly demonstrate that the OsGRF1 gene is not only involved in regulating growth at the juvenile stage, but that it may also be involved in the regulation of heading in rice.

Isolation of genes related to blood glucose-control in rat skeletal muscle

Obejctive To isolate genes related to blood glucose control using Sprague Dawley (SD) rat skeletal muscle Methods Differential gene expression between glucose stimulated and non glucose stimulated SD rat skeletal muscle was obtained by the differential display (DD) method, Slot blotting hybridization and Northern blot hybridization Results Several new genes that are differentially expressed in glucose stimulated and non glucose stimulated SD rat skeletal muscle were isolated 74 were verified by slot analysis from 181 gene tags isolated Of them, 33 were cloned and sequenced, and homologous analysis and application for GenBank Access Number were carried out 21 expressed sequence tag (EST) representing novel genes was confirmed by Northern blot analysis A total of 9 novel genes showed significant differential expression patterns Conclusions Using improvements and modifications of the differential display technique, a labor and cost saving route was used to identify new genes related to blood glucose control We investigated differentially expressed genes at the whole body level instead of the culture cell level, to ensure experimental results closer to the normal physiological state This technique may be valid in wide spread application to other related research