Enantioseparation of atropisomeric 1,1'-binaphthyl-2,2'-diyl hydrogen phosphate in capillary electrophoresis by using di- and oligosaccharides as chiral selectors: di- and oligosaccharide chiral selectors in capillary electrophoresis

Twelve different disaccharides and a series of noncyclic malto- and cello-oligosaccharides were used as chiral selectors in capillary electrophoresis (CE). Most saccharides resolved the enantiomers of atropisomeric 1,1'-binaphthyl-2,2'-diyl hydrogen phosphate (BDHP) depending on the type (alpha or beta) and position of the linkage between monosaccharides. The effect of chain length of malto- and cello-oligosaccharides on enantioseparation of BDHP was also investigated. The nature of cations in background electrolytes affected significantly the separation of BDHP enantiomers.     

Effect of transient cyclic AMP elevation on DNA synthesis in rat hepatocytes at G1 phase

Maintaining high levels of intracellular cyclic AMP (cAMP) is known to inhibit the growth of various proliferating cells including hepatocytes. We show here that transient (30 min) elevations of cAMP induced by addition of 8-bromo-cAMP (1 mmol/L) to rat hepatocytes in primary culture at three time points (12 h, 16 h and 20 h) after seeding stimulated DNA synthesis. Sustained levels of cAMP stimulated DNA synthesis to a lesser degree at a lower concentration (1 mumol/L), but inhibited it at concentrations higher than 100 mumol/L. We also determined cyclin-dependent kinase 2 (cdk2) activity in the hepatocytes during this incubation period. The transient addition of 8-bromo-cAMP at the late G1 phase increased cdk2 activity. This suggests that transient cAMP elevation in hepatocytes at the late G1 phase has a growth stimulation effect. Up-regulation of cdk2 activity may have a role in this process.     

聚铝无机高分子盐基度对成膜的影响

以市售普通陶瓷板为基膜,不同盐基度的聚铝液为浸渍液,采用原位造粒法制备微孔γ-Al2O3陶瓷膜.测定所制得的各种γ-Al2O3陶瓷膜的最大孔径、孔径分布曲线及最可几孔径.采用扫描电镜观察膜的形貌,研究聚铝无机高分子盐基度对成膜的影响.实验表明,采用高盐基度(66.7%以上)的聚铝浸渍液,才能制备成膜性能良好的超薄微孔陶瓷膜.     

Bioelectrical impedance analysis of body composition in patients with pulmonary emphysema

In this study we utilized bioelectrical impedance analysis (BIA) to compare the body composition of 36 stable pulmonary emphysema (PE) patients with 19 healthy controls. We compared the PE patients and healthy controls in terms of fat-free mass (FFM) and body fat (BF) as percentages of ideal body weight (FFM/IBW, BF/IBW). FFM/IBW and BF/IBW were significantly lower in the PE patients than in the controls (75.0 +/- 9.8% vs. 85.2 +/- 7.3%, p < 0.001 and 11.8 +/- 6.4% vs. 16.7 +/- 7.7%, p < 0.05, respectively). We divided the PE patients into two subgroups according to FFM, then investigated the relationships between FFM and skeletal muscle strength, and between FFM and respiratory muscle strength. In patients with reduced FFM (FFM < 43.5 kg) grip strength as an index of skeletal muscle strength was significantly lower than in patients without reduced FFM (FFM > or = 43.5 kg) (25.7 +/- 7.8 kg vs. 36.2 +/- 7.2 kg, p < 0.005). As indexes of respiratory muscle strength, maximal expiratory pressure (PEmax) and maximal inspiratory pressure (PImax) were lower in the patients with reduced of FFM, but not to a statistically significant degree (49.6 +/- 20.8 cm H2O vs. 58.7 +/- 23.9 cm H2O and 40.5 +/- 19.2 cm H2O vs. 50.2 +/- 22.1 cm H2O, respectively). In the PE patients, FFM correlated closely with vital capacity (r = 0.528, p < 0.001), forced vital capacity (FVC) (r = 0.531, p < 0.001), FEV1.0 (r = 0.554, p < 0.001), FEV1.0/FVC (r = 0.467, p < 0.005), RV/TLC (r = -0.395, p < 0.05), DLco (r = 0.770, p < 0.001), and DLco/VA (r = 0.622, p < 0.001). However no correlation was observed between BF and any of the measures of lung function. The findings of our study suggest that FFM correlates with skeletal muscle strength, respiratory muscle strength and some measures of lung function in patients with PE, and that assessments of body composition are valuable to their clinical management.     

Chondroitin sulfate proteoglycans protect cultured rat's cortical and hippocampal neurons from delayed cell death induced by excitatory amino acids

Protective effects of chondroitin sulfate proteoglycans (CSPGs) from rat's brain against delayed cell death induced by excitatory amino acids were examined in cultured neurons of the rat. CSPGs reduced delayed neuronal death induced by 10 min exposure to glutamate at a concentration between 100 microM and 1 mM when lactate dehydrogenase activity of culture medium was assayed 24 h after the exposure. CSPGs also protected neuronal death induced by 200 microM N-methyl-D-aspartate (NMDA), kainate or 100 microM alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA). CSPGs reduced death of cortical and hippocampal neurons even when they were administered at 2 h, but not 6 and 12 h, after the exposure to glutamate. These results indicate that CSPGs may have a neuroprotective action against acute noxious conditions in the brain.     

Photoresponses of MOS-FET

Photocurrent of a p-channel MOS-FET was measured as a function of illuminating position, gate voltage, and drain voltage after illumination by a light beam on its gate. Two different processes for photo-carrier excitation in a MOS structure are elucidated: one is an electron-hole pair excitation across the band gap of silicon in the depletion layer of the field-induced junction and another is an electron excitation through interface states at the silicon-silicon dioxide interface. The interface states concerned in the photo-carrier excitation are related to the levels caused by hydroxyl groups frozen at the interface. The levels are situated at 0·16 eV above the valence band of silicon.