乙酰胆碱对人胃粘膜上皮细胞和胃腺癌细胞内Ca2+、Mg2+浓度的影响

目的:探讨乙酰胆碱对人胃粘膜上皮细胞和胃腺癌细胞内Ca2 、Mg2 浓度的影响。方法:利用大型生化分析仪,检测了乙酰胆碱作用后培养的人胃粘膜上皮细胞和胃腺癌细胞内Ca2 、Mg2 的浓度。结果:与正常胃粘膜上皮细胞比较,胃腺癌细胞内Ca2 、Mg2 浓度偏低(P>0 01)。在乙酰胆碱作用下,胃粘膜上皮细胞内Ca2 浓度升高(P<0 01),Mg2 浓度降低(P<0 01);胃腺癌细胞仅有Ca2 浓度升高(P<0 05),Mg2 浓度无变化。阿托品能阻断乙酰胆碱的作用(P<0 05)。结论:乙酰胆碱对胃粘膜上皮细胞和胃腺癌细胞的作用是通过毒蕈碱受体实现的。     

弱相互作用下原子的玻色-爱因斯坦凝聚

从理论上分析提出了弱相互作用下Bose体系的BEC理论，并由此来解释液^4He的超流性。通过深入对比理想Bose气体和弱相互作用下Bose体系发生BEC性质的不同，分析得出了凝聚体系粒子间相互作用的有无是导致二者性质不同的主要原因。     

YBa2Cu3Oz超导体的低温稳定相

基于8点长方集团变分模型,并引入各向同性最近邻相互作用,以及各向异性次近邻相互作用,计算了YBa₂Cu₃O_z两Ba层间铜氧平面上□—O系统的有序—无序相变图,不仅在z=7.0附近得到具有超导电性的正交相,并且在z=6.5附近得到具有两倍晶格长度的另一种正交相(正交相Ⅱ)。 关键词：     

Formation of a two-dimensional periodic structure of local melting regions on a silicon surface upon pulsed light irradiation

The first results regarding the formation of a two-dimensional periodic structure of local melting regions on a silicon surface upon pulsed light irradiation are presented. The conditions are established, and the mechanism of the formation of such structures is discussed. Zh. Tekh. Fiz. 67, 97–99 (December 1997)     

5-[5-R-furfurylidene]-2,2-dimethyl-1,3-dioxane-4,6-diones 5. Nucleophilic replacement of halogen in the furan ring

Halogen in positions 3 and 5 of the furan ring in ftirfurylidenedioxanediones is readily replaced by dithiocarbonate, dithiocarbatnate, dithiophosphate, thiocyanate, and azide anions, and by thiourea, and secondary and tertiary amines. The conformation of the initial halogen derivative is retained in the substitution products.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 327–334, March, 1994.     

Mass spectra of pseudoguaianolides related to carpesiolin

The main directions of fragmentation and the EI of six pseudoguaianolides related to carpesiolin have been studied. It has been established that acylation of the OH group at C-6 suppresses the selective breakdown of the guaiane skeleton, while the simultaneous presence of AcO groups at C-2 and C-4 favors the formation of a number of characteristic ions. The hydrogenation of the exomethylene group has no appreciable influence on direction of fragmentation.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 530–535, July–August, 1993.     

Isolation of phospholipase A2 from the venom of the green toadBufo viridis

Phospholipase A₂ has been isolated fromthe venom of he Central Asian green toad Bufo viridis in the electroophoretically homogeneous state for the first time by biospecific absorption chromatography. The affinity sorbent used was Affi-Gel 10 with covalently bound phosphatidylserine (PDS). The chemical inertness of the bound PDS to the hydrolytic action of phospholipase A2 and its high tendency to form biospecific complexes have been shown. Some biochemical characteristics of the enzyme isolated have been studied: influence of the pH and of the Ca²⁺ concentration and dependence of activity on substrate concentration.A. S. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax 627071. Tashkent State University, fax 462472. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 105–109, January–February, 1994.     

电磁感应探测的灵敏度研究

本文讨论了电磁感应探测传感线圈的匝数与探测灵敏度的关系,论证了在探距确定的条件下,探测传感线圈直径的最优值。