Kinetic analysis of papaya proteinase omega

Papaya proteinase omega (pp omega) has been purified from dried latex both by immunoaffinity and traditional methods. Kinetic analysis revealed that (1), the pp omega-catalysed hydrolysis of N-benzoyl-L-arginine p-nitroanilide (BApNA) has a lower specificity (kcat/Km) than the same reaction catalysed by papain; (2), the pp omega-catalysed hydrolysis of a tripeptide substrate having phenylalanine at the second position (S2-site) showed a more similar specificity to that catalysed by papain; (3), the significant difference between the two enzymes is that steady state kinetics with both L-BApNA and a tripeptide enables the identification in pp omega of other ionizations affecting binding. The active sites of papain and pp omega can therefore be distinguished by pH-dependence of kcat/Km.     

Holocaust survivors and escapees: Their strengths.

The conclusions clinicians have drawn about Holocaust survivors over the last 50 yrs differ sharply from researchers' findings. It is important to evaluate these discrepancies since different perceptions of survivors affect treatment approaches. The researchers' view, stressing the survivor's resilience and resourcefulness, contrasts with clinical impressions centering on a survivor syndrome involving deep emotional disturbances as residues of the Holocaust experience. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Determination of the radiation sensitivity of the stromal cells in the murine long-term bone marrow culture by measuring the induction and rejoining of interphase chromosome breaks

PURPOSE: To determine the radiosensitivity of bone marrow stromal cells, the rate of interphase chromosome breakage and rejoining of stromal cells in the murine long term bone marrow culture and of human skin fibroblasts were compared. METHODS AND MATERIALS: The cells were irradiated with doses up to 6 Gy and repair times up to 6 hr were investigated. After induction of premature chromosome condensation by fusing the cells with mitotic HeLa cells, the number of interphase chromosome fragments was counted. RESULTS: The number of radiation induced breaks was found to be not significantly different for both cell types with 6.16 +/- 0.26 breaks per Gray for the fibroblasts and 5.96 +/- 0.20 breaks per Gray for the stromal cells. A significant difference was observed in the repair rate. The fibroblasts rejoined 39.6% of the breaks induced initially during the first hour after irradiation and 5.6 +/- 1.84 breaks remained unrejoined after 6 hr, while the stromal cells were able to rejoin 63.2% in 1 hr and had 2.05 +/- 0.07 breaks unrejoined after 6 hr. CONCLUSION: If the well substantiated assumption is made, that the capacity to repair DNA double strand breaks or interphase chromosome breaks is correlated with the cellular radiosensitivity, this finding indicate, that murine bone marrow stromal cells are more radioresistant than human skin fibroblasts.     

Preparation of the international employee: Career and consultation needs.

Studied how 26 senior managers and 47 senior professional technical staff (recently repatriated) of 4 US owned multinational organizations viewed their international posting, specifically with respect to career path satisfaction. Results of satisfaction scales indicate that many Ss felt under-prepared for their international assignment. It is suggested that a comprehensive international employee development program should assess, provide feedback, and coach individuals on career path, culture shock and adjustment, and performance issues prior, during, and on return from the expatriate assignment. Results suggest that opportunities exist for individual and organizational intervention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reliability and validity of the measurement of position sense in women with osteoarthritis of the knee

OBJECTIVE: We examined the test-retest reliability and the construct validity of the measurement of knee position sense for describing the functional weightbearing performance of women with osteoarthritis (OA) of the knee. METHODS: For the purpose of this study, position sense was defined as the error occurring when subjects attempted to reproduce a criterion angle in standing with visual cues eliminated. Five such tests were recorded photographically on 3 different occasions. On each occasion the 10 subjects also completed a self-paced walking test over a 13 m indoor walkway. RESULTS: The photographic measurements were reproducible (r = 0.90) and there was no change in positioning accuracy across sessions. There was a significant (p < 0.05) inverse correlation of 0.70 between the standard deviation of the mean individual measurements of position sense (precision of the test) and those of walking speed. CONCLUSION: Our study demonstrates good measurement reliability and a comparable mean angular error with repeated tests. It also suggests the amplitude of the variability of this error is a strong determinant of an individual OA patient's functional performance in walking.     

聚氧乙烯油酸酯的合成与物性

论述了合成聚氧乙烯油酸酯的较佳反应条件,探讨了不同EO加成数的聚氧乙烯油酸脂的表面物性规律。     

STRONG METAL-CERAMIC JOINTS

In this paper the technology for joining metals to ceramics is reviewed. The technologies of metal powder sintering, liquid phase joining with activated brazing alloys and with ceramic frit, solid-state joining, friction welding and mechanical fixation are described. In order to put some perspective on the mechanical data given in the literature, some evaluating remarks on mechanical testing are made.     

Mechanism for self-synchronization of femtosecond pulses in atwo-color Ti:sapphire laser

An experimental and theoretical analysis of the nonlinear coupling mechanism between the two solitary pulses circulating in a two-color femtosecond laser is presented. Two operation regimes; synchronized; and nonsynchronized; and a hysteresis of the transition between the two regimes are clearly observed; while independent modelocking and tunability of the output pulse trains is found in both regimes. Pulses in the range from 15 to 100 fs are synchronized with a timing jitter below 2 fs. The combined effects of cross-phase modulation and negative group velocity dispersion are shown to be responsible for the strong pulse correlation in the synchronized regime. Our experimental observations are in agreement with numerical simulations, thus confirming the theoretical model