排序方式: 共有43条查询结果,搜索用时 443 毫秒
11.
Brönstrup G Leiterer C Jahr N Gutsche C Lysov A Regolin I Prost W Tegude FJ Fritzsche W Christiansen S 《Nanotechnology》2011,22(38):385201
Electrical and optical properties of semiconducting nanowires (NWs) strongly depend on their diameters. Therefore, a precise knowledge of their diameters is essential for any kind of device integration. Here, we present an optical method based on dark field optical microscopy to easily determine the diameters of individual NWs with an accuracy of a few nanometers and thus a relative error of less than 10%. The underlying physical principle of this method is that strong Mie resonances dominate the optical scattering spectra of most semiconducting NWs and can thus be exploited. The feasibility of this method is demonstrated using GaAs NWs but it should be applicable to most types of semiconducting NWs as well. Dark field optical microscopy shows that even slight tapering of the NWs, i.e. diameter variations of a few nanometers, can be detected by a visible color change. Abrupt diameter changes of a few nanometers, as they occur for example when growth conditions vary, can be determined as well. In addition a profound analysis of the elastic scattering properties of individual GaAs NWs is presented theoretically using Mie calculations as well as experimentally by dark field microscopy. This method has the advantage that no vacuum technique is needed, a fast and reliable analysis is possible based on cheap standard hardware. 相似文献
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TS Lian JA Bellan JS Jahr RH Holton BD Nossaman PJ Kadowitz 《Canadian Metallurgical Quarterly》1996,27(1-2):73-87
Desmopressin is a synthetic analog of vasopressin used to promote hemostasis and reduce postoperative blood loss. Recent studies have shown that desmopressin decreases arterial blood pressure in the anesthetized rat and relaxes isolated segments of aorta and pulmonary artery. Responses to a clinical preparation of desmopressin were investigated in the hindquarters vascular bed of the cat under constant flow conditions so that changes in perfusion pressure directly reflect changes in vascular resistance. Responses to desmopressin and its vehicle, and the effect of receptor antagonists, inhibitors of prostaglandin, and nitric oxide synthesis inhibitors, were investigated. 相似文献
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Asynchronous release of synaptic vesicles determines the time course of the AMPA receptor-mediated EPSC 总被引:1,自引:0,他引:1
The contribution of intersynaptic transmitter diffusion to the AMPA receptor EPSC time course was studied in cultured CA1 hippocampal neurons. Reducing release probability 20-fold with cadmium did not affect the time course of the averaged AMPA receptor EPSC, even when receptor desensitization was blocked by cyclothiazide, suggesting that individual synapses contribute independently to the AMPA receptor-mediated EPSC. Deconvolution of the averaged miniature EPSC from the evoked EPSC showed that release probability decays only slightly faster than the EPSC, suggesting that the AMPA receptor EPSC time course is determined primarily by the asynchrony of vesicle release. Further experiments demonstrated that cyclothiazide, previously thought to affect only AMPA receptor kinetics, also enhances synaptic release. 相似文献
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Rhode Heyns G. Weiss Schwaibold Steingroever Hans Müller Kanitz H. J. Steinbeck K. Felix K. Höll P. de Fremery Edward Hofmann Konrad Lang O. Windhausen Trendtel W. Leithe W. Schulze Ilse Gaede v. Noël Jesser H. Elsner Pieper W. Schreiber Rudolf Abderhalden Renate Teske Hanson I. Stahn Krzywanek Fr. Bartschat Lars Erlandsen Ad. Hanak W. Bartels Kluge E. -E. Bauke Karl Bernhard G. Steinhoff W. Hämmerle C. I. Kruisheer Brüning Reichard K. J. Demeter M. Gordienko Flössner Jahr Diemair H. Mohler 《European Food Research and Technology》1939,78(1):48-112
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Re-Wen Wu Wei-Shiung Lian Yu-Shan Chen Jih-Yang Ko Shao-Yu Wang Holger Jahr Feng-Sheng Wang 《International journal of molecular sciences》2021,22(17)
Biophysical stimulation alters bone-forming cell activity, bone formation and remodeling. The effect of piezoelectric microvibration stimulation (PMVS) intervention on osteoporosis development remains uncertain. We investigated whether 60 Hz, 120 Hz, and 180 Hz PMVS (0.05 g, 20 min/stimulation, 3 stimulations/week for 4 consecutive weeks) intervention affected bone integrity in ovariectomized (OVX) mice or osteoblastic activity. PMVS (120 Hz)-treated OVX mice developed fewer osteoporosis conditions, including bone mineral density loss and trabecular microstructure deterioration together with decreased serum resorption marker CTX-1 levels, as compared to control OVX animals. The biomechanical strength of skeletal tissue was improved upon 120 Hz PMVS intervention. This intervention compromised OVX-induced sparse trabecular bone morphology, osteoblast loss, osteoclast overburden, and osteoclast-promoting cytokine RANKL immunostaining and reversed osteoclast inhibitor OPG immunoreactivity. Osteoblasts in OVX mice upon PMVS intervention showed strong Wnt3a immunoreaction and weak Wnt inhibitor Dkk1 immunostaining. In vitro, PMVS reversed OVX-induced loss in von Kossa-stained mineralized nodule formation, Runx2, and osteocalcin expression in primary bone-marrow stromal cells. PMVS also promoted mechanoreceptor Piezo1 expression together with increased microRNA-29a and Wnt3a expression, whereas Dkk1 rather than SOST expression was repressed in MC3T3-E1 osteoblasts. Taken together, PMVS intervention promoted Piezo1, miR-29a, and Wnt signaling to upregulate osteogenic activity and repressed osteoclastic bone resorption, delaying estrogen deficiency-induced loss in bone mass and microstructure. This study highlights a new biophysical remedy for osteoporosis. 相似文献
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H. Jahr 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1930,59(2-3):285-288
Ohne ZusammenfassungMitteilung aus dem Chemischen Laboratorium des Reichsgesundheitsamtes.bedeutet mit Abbildungen. 相似文献
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Griebel J. Großfeld Schwaibold E. Dinslage Schormüller Kanitz W. Ludorff W. Schreiber O. Windhausen Beckel M. Gordienko K. Höll G. Steinhoff Konrad Lang J. J. van Eck Diemair W. Sutthoff H. Mohler Rudolf Abderhalden Bäurle H. J. Steinbeck G. Steinhoff Pawletta Damm W. Hämmerle Lars Erlandsen W. Bartels Brüning Jesser Bames Kluge Rob Jungkunz W. Preiß C. Pyriki K. Müller Fr. Bartschat Jahr und A. Hanak 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1939,77(5):493-560
Ohne Zusammenfassung 相似文献
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