Primary electron donors for Azotobacter chroococcum nitrogenase

Augmentation mammaplasty by the transaxillary approach seems to be a safe and anatomically sound procedure which produces consistent results with a low complication rate. Our experiences with this procedure and our modifications in the technique are described. Two instruments which were designed to facilitate the procedure are reported. An anatomical justification for the transaxillary method is made.     

The ultrastructural and functional expression of the hepatocyte genome under conditions of prolonged inhibition of protein biosynthesis by cycloheximide. V]

A review of 76 Southampton children with Henoch-Sch?nlein purpura has confirmed that there is no evidence of a streptococcal aetiology in the majority of cases of this disease. Among these patients the frequency of preceding respiratory infection of all kinds was only 7 percent greater than that in controls. Data on month of admission in four areas of England and Scotland show that the incidence of the disease is lowest in the June-August period. Contrary to previous findings there is no marked peak of incidence in any single month.     

Chemical modification of genetic damage from continuous irradiation in mice

It has been demonstrated that Adeturon (S-2-aminoethyl-iso-thiuronium adenosine triphosphate) showed a marked protective effect against translocations induction in mice germ cells after chronic gamma-or neutron-irradiation.     

工业CT断层图像自动生成STL文件的方法

为了使工业CT（computed tomography）扫描获得的工件断层图像格式转换为快速原型设备所接受的数据格式,研究了工业CT断层图像数据格式自动生成STL（Stereolithography）文件格式的方法,并用VC^＋＋开发了软件,实验结果表明,效果较好。     

FPGA在超声气体温度测量中的应用

现场可编程门阵列FPGA(Field Programmable Gate Array)是新一代可编程ASIC器件,它综合了分立器件和大规模集成芯片的优点,在数字电路设计中应用极其广泛.在超声温度测量系统中,应用数字移相技术,结合现场可编程门阵列器件(FPGA)设计了一个高速计数器,实现燃烧气体温度的快速、准确测量.     

Solvents for growing Al2(WO4)3 single crystals from high-temperature solutions

The crystallization conditions of Al₂(WO₄)₃ from Li₂O–WO₃ solvents (molar ratio 30.0:70.0, 32.5:67.5, 35.0:65.0, 45.0:55.0 and 55.0:45.0) as well as from Na₂O–WO₃ solvents (molar ratio 25.0:75.0, 27.5:72.5, 30.0:70.0 and 32.5:67.5) have been investigated. The concentration and temperature regions of crystallization of Al₂(WO₄)₃ and the density, viscosity as well as the solution losses due to evaporation have been established. On the basis of the data obtained it has been concluded that the most suitable solvent for growing Al₂(WO₄)₃ single crystals is Na₂O–WO₃ with a molar ratio of 27.5:72.5.     

Deletion analysis of the starch-binding domain of Aspergillus glucoamylase

The large form of glucoamylase (GAI) from Aspergillus awamori(EC 3.2.1.3 [EC] ) binds strongly to native granular starch, whereasa truncated form (GAII) which lacks 103 C-terminal residues,does not. This C-terminal region, conserved among fungal glucoamylasesand other starch-degrading enzymes, is part of an independentstarch-binding domain (SBD). To investigate the SBD boundariesand the function of conserved residues in two putative substrate-bindingsites, five gluco-amylase mutants were constructed with extensivedeletions in this region for expression in Saccharomyces cerevisiae.Progressive loss of both starch-binding and starch-hydrolyticactivity occurred upon removal of eight and 25 C-terminal aminoacid residues, or 21 and 52 residues close to the N-terminus,confirming the requirement for the entire region in formationof a functional SBD. C-terminal deletions strongly impairedSBD function, suggesting a more important role for one of theputative binding sites. A GAII phenocopy showed a nearly completeloss of starch-binding and starch-hydrolytic activity. The deletionsdid not affect enzyme activity on soluble starch or thermo-stabilityof the enzyme, confirming the independence of the catalyticdomain from the SBD.     

A combination of Ag/alumina and Ag modified ZSM-5 to remove NOx and CO during lean conditions

Single and bi-metallic silver modified ZSM-5 catalysts were synthesized using different methods of preparation, characterized by several techniques and tested in simulated diesel conditions. Additionally the catalytic behaviour of the most active catalyst, containing 5 wt.% Ag and prepared by impregnation (5Ag(Imp)-H-ZSM-5), was studied over a broad temperature range with two reducing agents (octane and propene). To correlate the catalytic activity of the prepared catalysts with preparation parameters the materials were characterized by XRD, SEM, N₂-physisorption, octane/propene-TPD, EPR and ICP techniques. A dual bed system consisting of Ag/alumina and the most active zeolitic material (5Ag(Imp)-H-ZSM-5) was shown not only to substantially enhance the activity of Ag/alumina in the low temperature region, but also to completely oxidize the CO and unburned hydrocarbons.     

Protein structure alignment by incremental combinatorial extension (CE) of the optimal path

A new algorithm is reported which builds an alignment between two proteinstructures. The algorithm involves a combinatorial extension (CE) of analignment path defined by aligned fragment pairs (AFPs) rather than themore conventional techniques using dynamic programming and Monte Carlooptimization. AFPs, as the name suggests, are pairs of fragments, one fromeach protein, which confer structure similarity. AFPs are based on localgeometry, rather than global features such as orientation of secondarystructures and overall topology. Combinations of AFPs that representpossible continuous alignment paths are selectively extended or discardedthereby leading to a single optimal alignment. The algorithm is fast andaccurate in finding an optimal structure alignment and hence suitable fordatabase scanning and detailed analysis of large protein families. Themethod has been tested and compared with results from Dali and VAST using arepresentative sample of similar structures. Several new structuralsimilarities not detected by these other methods are reported. Specificone-on-one alignments and searches against all structures as found in theProtein Data Bank (PDB) can be performed via the Web athttp://cl.sdsc.edu/ce.html.