An evaluation of the differences in human evoked cortical potentials to visual stimuli

Saccharomyces cerevisiae nuclei possess a polyphosphatase activity which is insensitive to a number of inhibitors of ATPase and pyrophosphatase (PPase) activities of the same organelle. Heparin, an effective inhibitor of the nuclear polyphosphatase activity, does not alter either the ATPase and PPase activity. The nuclear polyphosphatase activity is optimal at pH 7.5. Bivalent metal cations stimulate this activity in the following order: Co2+ > Mg2+ > Zn2+ > Mn2+. However, the magnitude of the stimulating effect is much lower than that for the polyphosphatase activities from other organelles of the same yeast. The polyphosphatase activity is nearly the same for polyphosphates ranging from [symbol: see text] = 9 to [symbol: see text] = 208, but is 1.5 times higher for tripolyphosphate. The K(m) values for the hydrolysis of polyphosphates with chain lengths [symbol: see text] = 3, 15 and 208 are 100, 5 and 4.1 microM, respectively. The polyphosphatase activity differs in some properties from that of the cell envelope, cytosol and vacuoles of the same S. cerevisiae strain.     

真丝织物抗皱辐射接枝单体的选择

分别采用丙烯酰胺、硅氧烷、甲基丙烯酸羟乙酯、丙烯腈、Ｎ,Ｎ’－亚甲基双丙烯酰胺作为辐照接枝单体,对比实验结果表明,丙烯酰胺以及丙烯腈处理后的真丝织物颜色发黄;甲工丙烯酸羟乙酯处理过的织物颜色微红;而经Ｎ,Ｎ’－亚甲基双丙烯酰胺及硅氧烷处理后的织物,颜色接近织物的本色;Ｎ－Ｎ’－亚甲基丙烯酰胺,接枝转化率最高,接枝后织物急缓弹性增加最大。     

Genetic control of Drosophila virilis tyrosine decarboxylase activity

Tyrosine decarboxylase (TDC) activity was studied in flies of two Drosophila virilis lines having contrasting response to stress. Lines 101 and 147 exhibited different TDC activity. Genetic analysis of these differences was performed. TDC activity was shown to be controlled by one gene or a block of tightly linked genes. The gene controlling TDC activity was mapped to one autosome but not to chromosome 2. In line 101, short-term heat stress (38 degrees C, 60 min) resulted in reduction in TDC activity, whereas, in line 147, this activity remained unchanged.     

Differences in the stimulation of NO synthesis during heat shock in genetically different rats]

OBJECTIVES: In certain younger patients with congestive heart failure (CHF), Doppler/echocardiography has identified a "restrictive" pattern of early diastolic ventricular filling characterized by very rapid early filling and a steep deceleration slope. We asked whether a similar restrictive pattern can be identified in very old patients with CHF, and if so, what are its clinical correlates and prognostic implications. DESIGN: Retrospective cohort with prospective follow-up. SETTING: Academic long-term care facility. PARTICIPANTS: Thirty-nine residents with clinical CHF (age 89 +/- 5 (SD) years) MEASUREMENTS: Transmitral Doppler flow, clinical characteristics, recurrent CHF episodes, hospitalizations, and mortality were measured. RESULTS: Fifteen (38%) of the subjects had restrictive filling patterns, characterized by a ratio of early to late flow (E/A) > 1.00 and 24 (62%) had nonrestrictive patterns. The restrictive pattern was associated with a longer duration of CHF, more angina, and higher rate of symptomatic recurrences of CHF. CONCLUSION: A restrictive diastolic filling pattern may represent a late stage in the evolution of congestive heart failure when left ventricular filling pressure is markedly increased. The treatment of CHF in older patients may need to account for different patterns of diastolic filling.