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71.
Ramzi A.A. Mothana Sidgi S. Hasson Wulf Schultze Annette Mowitz Ulrike Lindequist 《Food chemistry》2011
The chemical composition of three essential oils obtained from the barks of three endemic Boswellia species namely, Boswellia dioscorides, Boswellia elongata and Boswellia socotrana which were collected from the Soqotra Island (Yemen), was investigated. In parallel to that evaluation of their antimicrobial and antioxidant activities was also carried out. The investigation led to the identification of 72, 70 and 67 constituents for B.dioscorides, B. elongata, and B. socotrana, respectively. The B. dioscorides oil was found to have a high content of monoterpene hydrocarbons (32.8%) with α-thujene (9.3%) and α-pinene (8.3%) as main components. Whereas, the essential oil of B. elongata was characterised by high diterpene content (31.7%), in which incensol (14.8%) was found to be the major constituent. On the other hand, the oil obtained from the B. socotrana was found to be predominated of monoterpene hydrocarbons (26.4%) and oxygenated monoterpenes (30.7%) with p-cymene (13.0%), 2-hydroxy-5-methoxy-acetophenone (16.3%) and camphor (11.6%). All essential oils possessed antimicrobial activity especially against Gram-positive bacteria with MIC-values between 1.8 and 17.2 mg/ml. Furthermore, the DPPH-radical scavenging assay exhibited only weak antioxidant activities (28%) at 1.0 mg/ml. 相似文献
72.
It has been shown that cocaine-induced convulsions and lethality appear to be mediated by serotonin and dopamine neurotransmission, respectively. However, many antidepressants considered for treatment of cocaine addiction target these monoamine systems and may thus amplify these toxic effects during relapse. In this study, the authors assessed whether pretreatment with antidepressants influences cocaine-induced toxicity in mice as well as the potency of these medications at cocaine-binding sites previously shown to be associated with cocaine toxicity. Overall, selective serotonin reuptake inhibitors (SSRIs) facilitated cocaine-induced convulsions but not lethality. Dopamine uptake inhibition facilitated cocaine-induced lethality, but not convulsion. The SSRI sertraline enhanced neither convulsions nor lethality and may be unique due to its high affinity for sigma receptors. These results have important implications for safe and effective addiction treatments. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
73.
Industrial product development requires continuous improvements in work procedures as a result of constantly changing demands.
Support tools have proven to be an oft chosen way to meet new demands; however, few research efforts have been made in how to implement new tools. This article is a contribution to knowledge on carrying out the implementation of support tools. The basis consists
of four field studies performed during 1994–1999, containing 78 qualitative research interviews and focusing on the implementation
and use of different support tools. A re-analysis has been performed of selected interviews from the field studies, in total
30 interviews. This resulted in recommendations for an implementation framework, consisting of an Implementation Cycle, Organizational Change Field and Managerial Consistence, and five implementation keys: Goal setting, Kowledge Development, Anchoring at All Levels, Suitable Resources and Focus on the Individual. 相似文献
74.
75.
Whereas the contribution from renewable energies in the electrical power market is increasing rapidly, similar progress in the heat market is yet to be made. A prerequisite for progress is the development of innovative support instruments that transcend the usual support through public subsidies or tax reductions. We present an overview of the various classes of possible instruments. Some particularly interesting instruments will be selected and evaluated, comparing them qualitatively and quantitatively for the case of Germany. The most favourable model is found to be a new, allocation-financed1 model known as the Bonus Model. This model will be described in more detail. 相似文献
76.
S Ritz A Turzynski HW Schütz A Hollmann G Rochholz 《Canadian Metallurgical Quarterly》1996,77(1-2):13-26
Age at death determination based on aspartic acid racemization in dentin has been applied successfully in forensic odontology for several years now. An age-dependent accumulation of D-aspartic acid has also recently been demonstrated in bone osteocalcin, one of the most abundant noncollagenous proteins of the organic bone matrix. Evaluation of these initial data on in vivo racemization of aspartic acid in bone osteocalcin was taken a step further. After purification of osteocalcin from 53 skull bone specimens, the extent of aspartic acid racemization in this peptide was determined. The D-aspartic acid content of purified bone osteocalcin exhibited a very close relationship to age at death. This confirmed identification of bone osteocalcin as a permanent, 'aging' peptide of the organic bone matrix. Its D-aspartic acid content may be used as a measure of its age and hence that of the entire organism. The new biochemical approach to determination of age at death by analyzing bone is complex and demanding from a methodologic point of view, but appears to be superior in precision and reproducibility to most other methods applicable to bone. 相似文献
77.
It has been claimed that anticipation occurs in ADPKD, i.e. endstage renal failure at progressively earlier age in successive generations. This observation might possibly point to unstable DNA as the molecular basis of ADPKD. We analysed 74 parent-offspring pairs of 148 families in Germany and Austria in whom (i) ADPKD was verified by appropriate imaging procedures and (ii) age at renal death was accurately known. The median difference for age at renal death between parent and offspring was 0 years, range -26.3 to +27.2 years. There was no deviation from normal (Gaussian) distribution according to the Shapiro-Wilk test (P = 0.75). We conclude that systematic anticipation cannot be demonstrated with this sample which had sufficient size for meaningful biostatistical analysis. 相似文献
78.
BR Ritz 《Canadian Metallurgical Quarterly》1995,21(6):478-486
OBJECTIVES: In this cross-sectional study 290 male employees of the public gas- and waterworks of Hamburg, Germany, were examined for symptoms of epicondylitis. Forty-one workers were diagnosed with symptoms of lateral or medial epicondylitis. The effect of employment in different job categories on the prevalence of epicondylitis was explored. METHODS: The diagnosis of epicondylitis was based on the study's own criteria and compared with criteria used in former studies. Jobs were categorized into high, moderate, and no exposure groups according to tasks regarded as strenuous for the elbow. The data were analyzed with the help of multivariate logistic regression. RESULTS: With the study's diagnostic criteria, the prevalence odds ratio (OR) for 10 years of high exposure to elbow straining work was 1.7 [95% confidence interval (95% CI) 1.04-2.68] for currently held jobs and 2.16 (95% CI 1.08-4.32) for formerly held jobs. For workers regarded as moderately exposed in current jobs the odds ratio for 10 years was 1.4 (95% CI 1.00-1.93). Very similar results were obtained for current exposure when stricter diagnostic criteria were employed. CONCLUSIONS: The results suggest a cumulative exposure effect with length of employment. Workers with high exposure in former jobs compared with employees with high exposure in their current job exhibited more residual or slight epicondylitis symptoms upon examination. 相似文献
79.
Fabian Sander Ulrike Fluch Jens Peter Hermes Marcel Mayor 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(2):349-359
The controlled assembly of gold nanoparticles in terms of the spatial arrangement and number of particles is essential for many future applications like electronic devices, sensors and labeling. Here an approach is presented to build up oligomers of mono functionalized gold nanoparticles by the use of 1,3‐bipolar azide alkyne cycloaddition click chemistry. The gold nanoparticles of 1.3 nm diameter are stabilized by one dendritic thioether ligand comprising an alkyne function. Together with di‐, tri‐ and tetra‐azide linker molecules the gold nanoparticle can be covalently coupled by a wet chemical protocol. The reaction is tracked with IR and UV–vis spectroscopy and the yielded organic‐inorganic hybrid structures are analyzed by transmission electron microscopy. To evaluate the success of this click chemistry reaction statistical analysis of the formed oligomers is performed. The geometric and spatial arrangements of the found oligomers match perfectly the calculated values for the used linker molecules. Dimers, trimers and tetramers could be identified after the reaction with the corresponding linker molecule. The results of this model reaction suggest that the used click chemistry protocol is working well with mono functionalized gold nanoparticles. 相似文献
80.