连接光异构化非天然氨基酸的RGD肽抑制细胞的附着

利用固相肽合成方法 ,将带有光敏基团偶氮苯的非天然氨基酸———苯基偶氮苯基苯丙氨酸与RGD肽连接 ,得到具有光敏功能的RGD肽 .非天然氨基酸连接在C端的RGD肽与HeLa细胞表面的整合素有很强的结合能力 .RGD侧链上的光敏基团的光致异构化对RGD肽与HeLa细胞表面的整合素的结合有一定的影响     

The internet and Japanese conception of privacy

It is sometimes suggested thatthere is no conception of privacy in Japan orthat, if there is, it is completely differentfrom Western conceptions of privacy. If thiswere so, finding common ground between Japanand the West on which to establish privacypolicies for the internet would be extremelydifficult if not impossible. In this paper wedelineate some of the distinctive differencesin privacy practices in Japan, but we maintainthat these differences do not prevent theestablishment of sound, shared, ethicalinformation privacy policies. We distinguishbetween a minimal conception of privacy that webelieve is shared by Japan and other societiesand richer conceptions of privacy that oftenreflect patterns of behavior distinctive ofparticular cultures. Although Japan and othersocieties share at least a minimal sense ofprivacy, a base on which to build, robustprivacy protection will not exist on theinternet until an internationally accepted richsense of privacy is developed.     

Early effects of oral administration of omeprazole and roxatidine on intragastric pH

Objective

The ideal medication for the treatment of acid-related diseases, e.g., peptic ulcers, stress-related gastric bleeding, functional dyspepsia, and gastroesophageal reflux disease, should have a rapid onset of action to promote hemostasis and relieve the symptoms. The aim of our study was to investigate the inhibitory effects on gastric acid secretion of a single oral administration of a proton pump inhibitor, omeprazole 20 mg, and an H₂-receptor antagonist, roxatidine 75 mg.

Methods

Ten Helicobacter pylori-negative male subjects participated in this randomized, two-way crossover study. Intragastric pH was monitored continuously for 6 h after single oral administration of omeprazole 20 mg and roxatidine 75 mg. Each administration was separated by a 7-d washout period.

Results

During the 6-h study period, the average pH after administration of roxatidine was higher than that after administration of omeprazole (median: 4.45 vs. 2.65; P=0.0367). Also during the 6-h study period, a longer duration of maintenance at pH above 2, 5, and 6 was observed after administration of roxatidine 75 mg than after administration of omeprazole 20 mg (median: 90.6% vs. 55.2%, P=0.0284; 43.7% vs. 10.6%, P=0.0125; 40.3% vs. 3.3%, P=0.0125; respectively).

Conclusions

In Helicobacter pylori-negative healthy male subjects, oral administration of roxatidine 75 mg increased the intragastric pH more rapidly than that of omeprazole 20 mg.     

Growth mechanism of a preferentially oriented mordenite membrane

INTRODUCTION Zeolite membranes have been investigated formany years due to their promising applications inseparations (Tavolaro and Drioli, 1999) and mem-brane reactors (Coronas and Santamaria, 1999). Oneof the challenges in the preparation of zeolite mem-branes is the control of the crystal orientation, espe-cially for zeolites that have an anisotropic porestructure (Caro et al., 2000). An ideal case is that thechannels in the zeolite crystals are perpendicular tothe support surfa…