Medical genetics: a marker for Stevens-Johnson syndrome

Stevens-Johnson syndrome and the related disease toxic epidermal necrolysis are life-threatening reactions of the skin to particular types of medication. Here we show that there is a strong association in Han Chinese between a genetic marker, the human leukocyte antigen HLA-B*1502, and Stevens-Johnson syndrome induced by carbamazepine, a drug commonly prescribed for the treatment of seizures. It should be possible to exploit this association in a highly reliable test to predict severe adverse reaction, as well as for investigation of the pathogenesis of Stevens-Johnson syndrome.     

SOVA解码的有效中止判据

Turbo解码的迭代解码的循环次数越多，误码性能就越能得到改善。但是SOVA解码的循环次数有一个限度，超过这一限度，改善程度有限，只会增加计算量和解码迟滞。为了减少不必要的计算量和解码迟滞，需要更有效率的迭代解码中止判据。提出为了SOVA（Soft out put Viterbi algorithm）解码的高效率的迭代解码中止判据，通过模拟，比较、分析了其性能。     

A disk of dust and molecular gas around a high-mass protostar

The processes leading to the birth of low-mass stars such as our Sun have been well studied, but the formation of high-mass (over eight times the Sun's mass, M(o)) stars remains poorly understood. Recent studies suggest that high-mass stars may form through accretion of material from a circumstellar disk, in essentially the same way as low-mass stars form, rather than through the merging of several low-mass stars. There is as yet, however, no conclusive evidence. Here we report the presence of a flattened disk-like structure around a massive 15M(o) protostar in the Cepheus A region, based on observations of continuum emission from the dust and line emission from the molecular gas. The disk has a radius of about 330 astronomical units (Au) and a mass of 1 to 8 M(o). It is oriented perpendicular to, and spatially coincident with, the central embedded powerful bipolar radio jet, just as is the case with low-mass stars, from which we conclude that high-mass stars can form through accretion.     

Recognition of bacterial glycosphingolipids by natural killer T cells

Natural killer T (NKT) cells constitute a highly conserved T lymphocyte subpopulation that has the potential to regulate many types of immune responses through the rapid secretion of cytokines. NKT cells recognize glycolipids presented by CD1d, a class I-like antigen-presenting molecule. They have an invariant T-cell antigen receptor (TCR) alpha-chain, but whether this invariant TCR recognizes microbial antigens is still controversial. Here we show that most mouse and human NKT cells recognize glycosphingolipids from Sphingomonas, Gram-negative bacteria that do not contain lipopolysaccharide. NKT cells are activated in vivo after exposure to these bacterial antigens or bacteria, and mice that lack NKT cells have a marked defect in the clearance of Sphingomonas from the liver. These data suggest that NKT cells are T lymphocytes that provide an innate-type immune response to certain microorganisms through recognition by their antigen receptor, and that they might be useful in providing protection from bacteria that cannot be detected by pattern recognition receptors such as Toll-like receptor 4.     

《庚辛玉册》：中国炼丹术在历史上的最后一部巨著

《庚辛玉册》是朱权（１３７８－１４４８年）的一部有关炼丹术的著作。西方学者琼克尔（Ｄ．Ｒ．Ｊｏｎｋｅｒ）认为这部书已经失佚。明代李时珍在《本划纲目》中多次引述此书。另外，有一些片段也散载在某些类书中。文章英译了多年来所辑得的引自此书的条文，并试从这点蛛丝马迹中探讨这部书。自从１９５８年和李约瑟博士合作研究中国炼丹术史以来，他们两人就一直注意这部书。作者数十年来访问海外学术机构多处，顺便查访此书，但还没有发现整本的《庚辛玉册》。１９９０年访问北京期间，薄树人陪作者和中山茂到北京图书馆查询此书，也无收获。今竟然读到１９９３年姚品文著《朱权研究》中有“北京图书馆有藏本”一句话。希望将来学者们能够对这部典籍做更全面的研究。     

低糖型金耳饮料口感调配研究初探

以金耳发酵液为主要原料，用木糖醇和低聚异麦芽糖作甜味剂，柠檬酸为酸味剂制成低糖型金耳饮料并进行口感调配。经正交试验，当添加木糖醇5．0％、低聚异麦芽糖3．5％、柠檬酸0．10％时产品口感较佳。且还原糖含量仅为0．52％。     

封闭空间电缆群散热的实验研究

采用循环夹层水套模拟电缆地沟的侧壁和底面，用６根带有内热源的镀铬抛光铜管（发热棒）模拟电缆群，模型采用全封闭，轴向的两端和顶盖用泡沫塑料板封口。改变发热棒在空腔中的位置，在１．７×１０５＜Ｒａ＜３．５×１０５范围内得出了换热系数随发热棒位置改变的变化规律，为电缆沟中电缆的优化放置提供依据。