脉冲填料萃取塔的研究

一、绪 言 最近原子能工业中的一些分离过程,例如铀的精制以及反应堆的核分裂生成物之分离与回收都需要高效率的萃取设备。 冲萃取塔是一种操作简便,容易控制而且效率较高的设备。过去十几年来,关于这种脉冲塔的流动机理与传质过程国内外曾经进行过研究。[1-6];[8-11] 本研究系在一瓷环填料塔中.以苯──醋酸──水系统为物料.进行脉冲萃取塔的性能试验;测定几种脉冲条件对液泛速度以及萃取容量系数的影响。在本实验范围内确定萃取效率最高时的脉冲条件。 二、宴 验 设 哥 本丈所用的雯验设各如第IN所示,萃取塔力一内泾36.5%米的硬质玻璃管…     

Mutations in SEC63 cause autosomal dominant polycystic liver disease

Mutations in PRKCSH, encoding the beta-subunit of glucosidase II, an N-linked glycan-processing enzyme in the endoplasmic reticulum (ER), cause autosomal dominant polycystic liver disease. We found that mutations in SEC63, encoding a component of the protein translocation machinery in the ER, also cause this disease. These findings are suggestive of a role for cotranslational protein-processing pathways in maintaining epithelial luminal structure and implicate noncilial ER proteins in human polycystic disease.     

ARSACS, a spastic ataxia common in northeastern Québec, is caused by mutations in a new gene encoding an 11.5-kb ORF

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS or SACS) is an early onset neurodegenerative disease with high prevalence (carrier frequency 1/22) in the Charlevoix-Saguenay-Lac-Saint-Jean (CSLSJ) region of Quebec. We previously mapped the gene responsible for ARSACS to chromosome 13q11 and identified two ancestral haplotypes. Here we report the cloning of this gene, SACS, which encodes the protein sacsin. The ORF of SACS is 11,487 bp and is encoded by a single gigantic exon spanning 12,794 bp. This exon is the largest to be identified in any vertebrate organism. The ORF is conserved in human and mouse. The putative protein contains three large segments with sequence similarity to each other and to the predicted protein of an Arabidopsis thaliana ORF. The presence of heat-shock domains suggests a function for sacsin in chaperone-mediated protein folding. SACS is expressed in a variety of tissues, including the central nervous system. We identified two SACSmutations in ARSACS families that lead to protein truncation, consistent with haplotype analysis.     

基本物理理论的要求

《基本物理理论的要求》一文,是当代伟大的物理学家狄拉克逝世前两年的一篇讲演记录二文章将作者豹重正化不是量子理论的完整形式和经典观念必须彻底抛弃等一贯思想表述得更为清晰和强烈.它将滋励物理学家们去建立更完美的量子理论.     

Pneumococcal genome sequencing tracks a vaccine escape variant formed through a multi-fragment recombination event

Streptococcus pneumoniae ('pneumococcus') causes an estimated 14.5 million cases of serious disease and 826,000 deaths annually in children under 5 years of age(1). The highly effective introduction of the PCV7 pneumococcal vaccine in 2000 in the United States(2,3) provided an unprecedented opportunity to investigate the response of an important pathogen to widespread, vaccine-induced selective pressure. Here, we use array-based sequencing of 62 isolates from a US national monitoring program to study five independent instances of vaccine escape recombination(4), showing the simultaneous transfer of multiple and often large (up to at least 44 kb) DNA fragments. We show that one such new strain quickly became established, spreading from east to west across the United States. These observations clarify the roles of recombination and selection in the population genomics of pneumococcus and provide proof of principle of the considerable value of combining genomic and epidemiological information in the surveillance and enhanced understanding of infectious diseases.