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排序方式: 共有41条查询结果,搜索用时 15 毫秒
1.
S Knecht M Deppe EB Ringelstein M Wirtz H Lohmann B Dr?ger T Huber H Henningsen 《Canadian Metallurgical Quarterly》1998,29(6):1155-1159
BACKGROUND AND PURPOSE: Since functional transcranial Doppler ultrasonography (fTCD) allows convenient and fully automated quantification of language lateralization, it seems ideal for longitudinal studies of perfusion changes during deterioration as well as recovery of language functions. However, during serial examinations, the technical, stochastic, and physiological variabilities of cerebral blood flow velocities (CBFV) have to be considered. Therefore, before fTCD is accepted as a tool for evaluation of changes in lateralization in the diseased state, its reliability in healthy subjects needs to be determined. METHODS: We performed fTCD during a word generation task based on a previously validated technique with automated calculation of the averaged CBFV differences in the middle cerebral arteries providing an index of lateralization (LI). RESULTS: (1) The accuracy of the LI as assessed by the confidence interval was better than 1% of the mean hemispheric difference. (2) On repeated examination, LIs obtained from 10 subjects showed a high test-retest reproducibility (Pearson product moment correlation coefficient r = 0.95, P < 0.0001). (3) On 10 repeated assessments of LI in the same subject, no practice effects were detected. CONCLUSIONS: Functional TCD is a suitable and very robust tool for the longitudinal quantitative measurement of cerebral language lateralization. 相似文献
2.
J. O. Henningsen 《Journal of Infrared, Millimeter and Terahertz Waves》1986,7(10):1605-1629
Using a quasi-CW CO2 oscillator-amplifier combination with peak power 300 Watt, we have generated FIR laser emission in weak absorption bands of CH3OH. 40 new lines are reported, and their wavelengths are measured with a relative accuracy of 5×10?5. A total of 72 lines are assigned. 34 of these involve torsional n=1, 2, and 3 states of the CO stretch and the vibrational ground state. The remaining lines are associated with the CH3-rock, OH-bend, and CH3-deformation modes. The latter are located 1460 cm?1 above the ground state, and are pumped by simultaneous vibrational excitation and torsional deexcitation. 相似文献
3.
Effect of preventive maintenance intervals on reliability and maintenance costs of wind turbine gearboxes
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As many of the installed wind turbines (WTs) get older or approach their design life, there will be a drive to keep extending the lives of the main components especially the gearbox. The challenge of operations and maintenance will potentially be even more as there will be a need to keep the cost to a minimum. Similarly, as years of experience of operating WTs accumulate, knowledge about the behaviour and failure of subsystems is gained as well. Also with good documentation and repository of historical operational, performance and failure data, future decisions of operations and maintenance can be taken on the basis of insights from past experience. This paper presents an approach for implementing preventive maintenance (PM) by using historical failure data to determine the optimal PM interval required to maintain desired reliability of a typical module or subassembly. This paper builds upon previous research in the area of WT gearbox reliability analysis and prediction, taking it further by examining the relationships between the frequency of a PM task and the reliability, availability and maintenance costs. The approach presented demonstrates how historical in‐service failure data can be used in PM task selection based on the minimum maintenance cost and maximum availability. Available historical field failure data of the high speed module of a Vestas 2MW WT gearbox is used to validate the approach and show its practicality. The results of this study are then presented—indicating that choosing the right PM interval based on the minimum unit maintenance cost and maximum availability also improves WT gearbox reliability. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
4.
M Grummt G Woehlke U Henningsen S Fuchs M Schleicher M Schliwa 《Canadian Metallurgical Quarterly》1998,17(19):5536-5542
Conventional kinesin is a molecular motor consisting of an N-terminal catalytic motor domain, an extended stalk and a small globular C-terminus. Whereas the structure and function of the catalytic motor domain has been investigated, little is known about the function of domains outside the globular head. A short coiled-coil region adjacent to the motor domain, termed the neck, is known to be important for dimerization and may be required for kinesin processivity. We now provide evidence that a helix-disrupting hinge region (hinge 1) that separates the neck from the first extended coiled-coil of the stalk plays an essential role in basic motor activity. A fast fungal kinesin from Syncephalastrum racemosum was used for these studies. Deletion, substitution by a coiled-coil and truncation of the hinge 1 region all reduce motor speed and uncouple ATP turnover from gliding velocity. Insertion of hinge 1 regions from two conventional kinesins, Nkin and DmKHC, fully restores motor activity, whereas insertion of putative flexible linkers of other proteins does not, suggesting that hinge 1 regions of conventional kinesins can functionally replace each other. We suggest that this region is essential for kinesin movement in its promotion of chemo-mechanical coupling of the two heads and therefore the functional motor domain should be redefined to include not only the catalytic head but also the adjacent neck and hinge 1 domains. 相似文献
5.
Henningsen J. Inguscio M. Moretti A. Strumia F. 《Quantum Electronics, IEEE Journal of》1982,18(6):1004-1008
Four new FIR laser lines at 62.98, 48.77, 224.53, and 190.65 μm are reported from CH3 OH, optically pumped by the 10R34 and 9R10 lines of a waveguide CO2 laser. Measurements performed by several techniques confirm that the pump offsets are outside the tuning range of conventional CO2 lasers. Two of the lines are assigned as highJ transitions within the torsional ground state of the CO stretch. 相似文献
6.
Henningsen David Dryden; Cruz Michael G.; Miller Mary Lynn 《Canadian Metallurgical Quarterly》2000,4(2):168
The relationship between social loafing and decision making was examined in an individual predeliberation thinking task. Participants (N?=?189) were asked to read information and make decisions ostensibly in order to make a future individual or group decision. Decision type (intellective or judgmental) and anticipated group size (individuals or 4 or 8 members) were manipulated to examine their effect on information recall. Individuals who anticipated working alone or who believed they were making intellective decisions recalled more information than did those who anticipated working in groups or who believed they were making judgmental decisions. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
7.
Ming Yan Philip Hartjen Martin Gosau Tobias Vollkommer Audrey Laure Cline Grust Sandra Fuest Lan Kluwe Simon Burg Ralf Smeets Anders Henningsen 《International journal of molecular sciences》2022,23(1)
Cold plasma treatment increases the hydrophilicity of the surfaces of implants and may enhance their integration with the surrounding tissues. The implaPrep prototype device from Relyon Plasma generates cold atmospheric plasma via dielectric barrier discharge (DBD). In this study, titanium surfaces were treated with the implaPrep device for 20 s and assessed as a cell culture surface for fibroblasts. One day after seeding, significantly more cells were counted on the surfaces treated with cold plasma than on the untreated control titanium surface. Additionally, the viability assay revealed significantly higher viability on the treated surfaces. Morphological observation of the cells showed certain differences between the treated and untreated titanium surfaces. While conventional plasma devices require compressed gas, such as oxygen or argon, the implaPrep device uses atmospheric air as the gas source. It is, therefore, compact in size and simple to handle, and may provide a safe and convenient tool for treating the surfaces of dental implants, which may further improve the implantation outcome. 相似文献
8.
Within a period of four years 35 patients with metastatic breast cancer were treated with tamoxifen. One third had objective remissions, average duration of complete remission being 30.6 months and of partial remission 13.7 months. Mean survival time from start of tamoxifen treatment in five patients with complete remission was 30.6 months while in seven with partial remission it was 20.4 months. Nine patients with unresponsive metastases had a mean survival time of 24.3 months, the remaining 14 patients who deteriorated surviving for 11.7 months. Ten of the 12 patients who responded well were over 60 years old. Lymph-node and lung or pleural metastases were significantly reduced by treatment in four of eight and six of 15 cases, respectively. Satisfactory regression of bony metastases was never seen. Because of this, combined tamoxifen (10 mg twice daily) and methandrostenolone (1 mg twice daily) was given to an additional five patients, with one of them responding. Side effects included thrombocytopenia and hypercalcaemia. 相似文献
9.
Jonas Lagergren Tarras Wanheim Woijtech Precz Poul Henningsen Mogens Arentoft Nils‐Gran Jonsson 《国际钢铁研究》2006,77(6):430-438
The only way to establish the true rolling pressure and the true friction condition in cold rolling is to conduct measurements in the roll bite. A new transducer design is therefore proposed, in order to overcome problems in previous measurements in the past 70 years. The new idea is to increase the contact surface of the transducer, to be larger than the arc of contact. This is in contrast to the smaller and smaller contact pin design that has been prevailing. The measurements were conducted during cold dry rolling of both copper strips and stainless steel strips in a pilot mill. The recordings were selected from a steady state with no disturbance from the material flow. The transducer was able to simultaneously measure both the normal pressure and the friction stress. An estimation of the coefficient of friction was accordingly performed. The new transducer works very well, it was seen to be robust and able to avoid signal disturbance. The pressure and friction stress distribution results was as expected by the authors and showed good reproducibility, together with a proven agreement between recorded and simulated signals. 相似文献
10.
RK Reinscheid J Higelin RA Henningsen FJ Monsma O Civelli 《Canadian Metallurgical Quarterly》1998,273(3):1490-1495
A genetic polymorphism in the metabolism of the anticonvulsant drug S-mephenytoin has been attributed to defective CYP2C19 alleles. This genetic polymorphism displays large interracial differences with the poor metabolizer (PM) phenotype representing 2-5% of Caucasian and 13-23% of Oriental populations. In the present study, we identified two new mutations in CYP2C19 in a single Swiss Caucasian PM outlier (JOB 1) whose apparent genotype (CYP2C19*1/CYP2C19*2) did not agree with his PM phenotype. These mutations consisted of a single base pair mutation (G395A) in exon 3 resulting in an Arg132-->Gln coding change and a (G276C) mutation in exon 2 resulting in a coding change Glu92-->Asp. However, the G276C mutation and the G395A mutation resided on separate alleles. Genotyping tests of a family study of JOB1 showed that the exon 2 change occurred on the CYP2C19*2 allele, which also contained the known splice mutation in exon 5 (this variant is termed CYP2C19*2B to distinguish it from the original splice variant now termed CYP2C19*2A). The exon 3 mutation resided on a separate allele (termed CYP2C19*6). In all other respects this allele was identical to one of two wild-type alleles, CYP2C19*1B. The incidence of CYP2C19*6 in a European Caucasian population phenotyped for mephenytoin metabolism was 0/344 (99% confidence limits of 0 to 0.9%). Seven of 46 Caucasian CYP2C19*2 alleles were CYP2C19*2B(15%) and 85% were CYP2C19*2A. The Arg132Gln mutation was produced by site-directed mutatgenesis and the recombinant protein expressed in a bacterial cDNA expression system. Recombinant CYP2C19 6 had negligible catalytic activity toward S-mephenytoin compared with CYP2C19 1B, which is consistent with the conclusion that CYP2C19*6 represents a PM allele. Thus, the new CYP2C19*6 allele contributes to the PM phenotype in Caucasians. 相似文献