Synthesis and comparative molecular field analysis (CoMFA) of antitumor 3-arylisoquinoline derivatives

In this study a series of 3-arylisoquinoline derivatives were synthesized and cytotoxicity against human melanoma tumor cell evaluated, and a three dimensional quantitative structure-activity relationship was investigated using the comparative molecular field analysis (CoMFA). The results suggested that the electrostatic, steric and hydrophobic factors of 3-arylisoquinolines were strongly correlated with the antitumor activity. Considerable predictive ability (cross-validated r2 as high as 0.721) was obtained through CoMFA.     

New one-week, low-dose triple therapy for the treatment of duodenal ulcer with Helicobacter pylori infection

BACKGROUND: Antimicrobial therapy is the recommended treatment for duodenal ulcer associated with Helicobacter pylori infection. The eradication of bismuth-based triple therapy with bismuth subcitrate, metronidazole and amoxicillin is limited by low compliance, drug resistance and side-effects. Two-week proton pump inhibitor (PPI)-based triple therapy has a higher eradication rate but is costly. This study was designed to compare the efficacy, patient compliance and cost of short-term PPI-based triple therapy with those of bismuth-based triple therapy. METHODS: Ninety patients with active duodenal ulcer disease and H pylori infection, proven with the 13C-urea breath test and CLO test (Campylobacter-like organism test) were treated randomly in three therapeutic groups: Group A, DeNol 120 mg, amoxicillin 500 mg and metronidazole 250 mg four times a day orally for 14 days; Group B, omeprazole 20 mg plus clarithromycin 500 mg twice a day and amoxicillin 500 mg four times a day for 14 days; Group C, omeprazole 20 mg, clarithromycin 250 mg and metronidazole 500 mg twice a day for seven days. Nizatidine 150 mg twice a day was given continuously following the end of anti-H pylori therapy for each group. Two months later, endoscopy, the CLO test and 13C-urea breath test were repeated to assess the eradication rate of H pylori and the ulcer-healing rate. Drug tolerance was evaluated by patients themselves by daily recording of any side-effects. RESULTS: Eighty-four patients completed the entire course of therapy and evaluation for H pylori infection. The H pylori eradication rates in Groups A, B and C were 75% (21/28), 93% (26/28) and 89% (25/28), respectively (p = 0.466). The ulcer healing rate was 86% (24/28) in Group A and 89% (25/28) in Groups B and C (p = 0.764). A total of 74 patients (88%) were free from symptoms at the end of the triple therapy. Symptom relief was faster in patients with PPI-based triple therapy (Groups B and C) (days 3 and 4) than for patients with bismuth-based triple therapy (day 5). The cost of Group C therapy was lower than that for Groups A and B. There were no major side-effects in any of the patients. CONCLUSIONS: One-week triple therapy with omeprazole, clarithromycin and metronidazole is highly effected for the eradication of H pylori. A therapeutic regime of one week's duration with lower cost, good compliance and mild side-effects may offer a good choice for treatment of duodenal ulcer associated with H pylori infection in clinical practice.     

影响晶体管功放音质的因素与对策

可变的时延影响功放的动态稳定。降低电路对进入非线性的敏感度,是降低TIM的一种有效方法。提高晶体管功放动态余量,是改善其音质的良好途径。设计不合理的过流保护电路,限制了功放在复合性阻抗负载下的输出功率。本文分析了以上原因,给出了解决方法。     

光盘的出错率分析和研究

本文通过对光存储系统出错特性的分析，研究了一些描述出错特性的主要参数，并且给出了描述出错特性的Ｇｉｌｂｅｒｔ模型及其改进型模型。     

动态毛吸法测定纤维表面能

本文用浸润测定仪对玻璃纤维和Kevlar-49芳纶纤维进行了表面能测定,讨论了纤维束柱末端沾湿量的影响,提出了浸润仪测试数据的正确处理方法,求得了Kevlar-49纤维的表面能并对其色散分量和非色散分量进行了解析.     

The simplified two-pipette technique is more efficient than the conventional three-pipette method for blastomere biopsy in human embryos

Kell and Kx are two quantitatively minor proteins from the human erythrocyte membrane which carry blood groups antigens and are thought to be a metalloprotease and a membrane transporter, respectively. In the red cell membrane, these proteins form a complex stabilized by disulfide bond(s). Phosphorylation status of these proteins was studied, in the presence or absence of effectors of several kinases, either on intact cells incubated with [32P]-orthophosphate or on ghosts incubated with [gamma-32P]ATP. Purification of Kell-Kx complex, by immunochromatography on an immobilized human monoclonal antibody of Kell blood group specificity allowed to establish that (i) neither protein is phosphorylated on tyrosine; (ii) the Kell protein is a putative substrate for Casein Kinase II (CKII) and Casein Kinase I (CKI) but not for protein kinase C (PKC), whereas Kx protein is phosphorylated by CKII and PKC but not by CKI; (iii) Protein Kinase A neither phosphorylates the Kell nor the Kx proteins.     

螺旋挤压机设计的改进

介绍了热压型焦工艺设备螺旋挤压机设计改进情况。     

An optimal instruction scheduler for superscalar processor

Performance in superscalar processing strongly depends on the compiler's ability to generate codes that can be executed by hardware in an optimal or near optimal order. Generating optimal code is an NP-complete problem. However, there is a need for highly optimized code, such as in superscalar or real-time systems. In this paper, an instruction scheduling scheme for optimizing a program trace is proposed. Optimized code can be arrived at without much redundant work, if some important features in code are well explored and utilized in scheduling. To formalize the task, two abstract models, one for a superscalar processor and the other for a program trace, are given. These two models reflect most of the characteristics of the scheduling problem. The interrelations between instructions and partial schedules are thoroughly studied, and dominance and equivalence relations on them are defined. These relations are then used to reduce the solution space and eventually help to produce optimal schedules. The results of experiments that show the promise of the proposed scheme are also presented