喀斯特自然土壤中AM真菌对先锋植物根系的影响

【目的】研究丛枝菌根(Arbuscular mycorrhiza，AM)真菌在喀斯特自然土壤条件下对喀斯特先锋草本植物根系的影响。【方法】通过自然土接种AM真菌(N)、灭菌土接种AM真菌(M)及灭菌土壤对照(S)共3种土壤处理，种植喀斯特先锋植物狗尾草(Setaria viridis)、荩草(Arthraxon hispidus)、鬼针草(Bidens pilosa)及狼杷草(Bidens tripartita)，并测定它们的根系生物量、根长、根表面积、根体积、根平均直径、根尖数及根分枝数。【结果】荩草、鬼针草及狼杷草在N处理及M处理下具有较高的菌根侵染率，狗尾草的菌根侵染率较低。与S处理相比，M处理下AM真菌明显提高了荩草、鬼针草及狼杷草的根系生物量、根长、根表面积、根体积、根尖数、根分枝数及组织密度，降低了根平均直径、比根长、比根面积及比根体积；与M处理相比，N处理明显降低了荩草、鬼针草及狼杷草的根系生物量、根长、根表面积、根体积、根尖数、根分枝数及组织密度，提高了比根长、比根面积及比根体积，但对根平均直径无明显影响。【结论】荩草、鬼针草及狼杷草具有较高菌根侵染率，能与AM真菌共生获得更加发达的根系，而自然土壤削弱了AM真菌对荩草、鬼针草及狼杷草根系生长的促进作用。     

Disruption of P2RY5, an orphan G protein-coupled receptor, underlies autosomal recessive woolly hair

The genetic determinants of hair texture in humans are largely unknown. Several human syndromes exist in which woolly hair comprises a part of the phenotype; however, simple autosomal recessive inheritance of isolated woolly hair has only rarely been reported. To identify a gene involved in controlling hair texture, we performed genetic linkage analysis in six families of Pakistani origin with autosomal recessive woolly hair (ARWH; OMIM 278150). All six families showed linkage to chromosome 13q14.2-14.3 (Z = 17.97). In all cases, we discovered pathogenic mutations in P2RY5, which encodes a G protein-coupled receptor and is a nested gene residing within intron 17 of the retinoblastoma 1 (RB1) gene. P2RY5 is expressed in both Henle's and Huxley's layers of the inner root sheath of the hair follicle. Our findings indicate that disruption of P2RY5 underlies ARWH and, more broadly, uncover a new gene involved in determining hair texture in humans.     

基于并行工程的产品开发过程管理的研究

并行工程采用集成化与并行化的思想来开发产品,强调在信息集成基础上的过程集成,运用工作流管理技术能够很好地达到此目的。在分析工作流管理技术的基础上,以冲压模具的开发过程为例来说明用工作流管理技术实现产品开发过程管理的     

The gene encoding R-spondin 4 (RSPO4), a secreted protein implicated in Wnt signaling, is mutated in inherited anonychia

Anonychia and hyponychia congenita (OMIM 206800) are rare autosomal recessive conditions in which the only presenting phenotype is the absence or severe hypoplasia of all fingernails and toenails. After determining linkage to chromosome 20p13, we identified homozygous or compound heterozygous mutations in the gene encoding R-spondin 4 (RSPO4), a secreted protein implicated in Wnt signaling, in eight affected families. Rspo4 expression was specifically localized to developing mouse nail mesenchyme at embryonic day 15.5, suggesting a crucial role in nail morphogenesis.     

GH220合金中碳化物相变规律

研究了合金中M_6C,M_(23)C_6及MC的晶体结构、化学组成、形态、分布及数量,它们的溶解析出规律及互相转化。