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1.
Forty-three lines of barley, including ancestral (wild), landraces, Middle Eastern lines, and modern cultivars, were grown under two different sets of environmental conditions. Hordenine production in barley roots was determined at the one-leaf stage by HPLC analysis and, in two lines only, over a period of 35 days. Forty-two of the 43 lines produced significant amounts of hordenine, although there was no variation among groups. Middle Eastern lines had the highest production with 327 µg/g on a dry weight basis. Production was, however, determined more by environmental conditions during growth than by genetic factors. Hordenine production was up to seven times higher in plants grown under lower light intensities. 相似文献
2.
W. Kulisch C. Popov H. Rauscher L. Sirghi T. Sasaki S. Bliznakov F. Rossi 《Diamond and Related Materials》2008,17(7-10):1116-1121
Nucleation and growth, but especially the development of the morphology of nanocrystalline diamond/amorphous carbon (NCD/a-C) nanocomposite films have been investigated by systematic variation of three important parameters, namely the deposition time, the growth rate, and the substrate pre-treatment used to enhance the nucleation density. The films have been characterized, among others, by scanning electron microscopy, atomic force microscopy, and Fourier transform infrared spectroscopy. It is shown that, by successive addition of ultradispersive diamond powder to the suspension of nanocrystalline diamond powder in n-pentane used for the ultrasonic pre-treatment, the nucleation density can be enhanced by two orders of magnitude from 1 · 108 cm− 2 to > 1 · 1010 cm− 2. This reduces the thickness required to achieve closed films from 1 µm to 100 nm. However, once coalescence of the individual nodules emerging from the nucleation sites has taken place the films loose “memory” of the nucleation step and start to develop the typical NCD morphology consisting of larger features with diameters of some hundreds of nm which are in turn composed of much smaller features. Irrespective of the feature size and of the parameters used, the films of this investigation possess AFM rms roughnesses of 9–13 nm, indicating that rms values are not sufficient to characterize NCD surfaces. 相似文献
3.
Administration of highly concentrated, highly potent, and therefore highly dangerous drugs with syringe pumps is common in modern anaesthesia as well as in intensive care and emergency medicine. Because of their exact flow rates down to < 1 ml/h, these pumps are predestined for delivery of drugs with short half-lives, such as catecholamines and vasodilators. But intravenous application of drugs with syringe pumps is not without problems. While it is well known that syringes not fixed correctly into the pump can empty themselves by the influence of gravity, it seems not to be known that hydrostatic pressure can influence the flow rate of a correctly connected system even during continuous infusion. In this situation a change of height of the syringe pump in relation to the patient's position can have tremendous effects on hemodynamics due to unintended acceleration or deceleration of the flow rate. This case report demonstrates that the elevation of a connected epinephrine pump while moving a cardiac surgery patient after ACB operation from the operation table into his bed led to critical increases of heart rate, blood pressure and left atrial pressure. In order to quantify the problem we repeated the situation experimentally. It could be demonstrated that the elevation of the syringe pump by 80-100 cm delivers an additional bolus of 4-5 drops as the central venous catheter outlet. Lowering the pump consecutively leads to the opposite effect. In the case reported, the accidentally administered bolus of epinephrine was 12-15 micrograms (we use a concentration of 60 micrograms/ml epinephrine for continuous infusion with syringe pumps). From this accidental observation the following conclusion can be drawn: The change of height, in relation to the patient's position, of a running syringe pump during continuous infusion of highly concentrated cardiovascular drugs may cause considerable, even life-threatening hemodynamic disorders. Even in a closed infusion system (syringe-extension-central venous catheter), hydrostatic pressure influences infusion rate. Elevation of the pump leads to unintended bolus administration, and lowering of the pump is followed by an interruption of the infusion. In the knowledge of this phenomenon, unexpected hemodynamic reactions during transport of critically ill patients cannot always be interpreted as a result of inadequate anesthesia or volume load, but may be a consequence of incorrect handling of the syringe pumps as described in this report. 相似文献
4.
Wolfram Witte Daniel Abou‐Ras Karsten Albe Gottfried H. Bauer Frank Bertram Christian Boit Rudolf Brüggemann Jürgen Christen Jens Dietrich Axel Eicke Dimitrios Hariskos Matthias Maiberg Roland Mainz Max Meessen Mathias Müller Oliver Neumann Thomas Orgis Stefan Paetel Johan Pohl Humberto Rodriguez‐Alvarez Roland Scheer Hans‐Werner Schock Thomas Unold Alfons Weber Michael Powalla 《Progress in Photovoltaics: Research and Applications》2015,23(6):717-733
The gallium gradient in Cu(In,Ga)Se2 (CIGS) layers, which forms during the two industrially relevant deposition routes, the sequential and co‐evaporation processes, plays a key role in the device performance of CIGS thin‐film modules. In this contribution, we present a comprehensive study on the formation, nature, and consequences of gallium gradients in CIGS solar cells. The formation of gallium gradients is analyzed in real time during a rapid selenization process by in situ X‐ray measurements. In addition, the gallium grading of a CIGS layer grown with an in‐line co‐evaporation process is analyzed by means of depth profiling with mass spectrometry. This gallium gradient of a real solar cell served as input data for device simulations. Depth‐dependent occurrence of lateral inhomogeneities on the µm scale in CIGS deposited by the co‐evaporation process was investigated by highly spatially resolved luminescence measurements on etched CIGS samples, which revealed a dependence of the optical bandgap, the quasi‐Fermi level splitting, transition levels, and the vertical gallium gradient. Transmission electron microscopy analyses of CIGS cross‐sections point to a difference in gallium content in the near surface region of neighboring grains. Migration barriers for a copper‐vacancy‐mediated indium and gallium diffusion in CuInSe2 and CuGaSe2 were calculated using density functional theory. The migration barrier for the InCu antisite in CuGaSe2 is significantly lower compared with the GaCu antisite in CuInSe2, which is in accordance with the experimentally observed Ga gradients in CIGS layers grown by co‐evaporation and selenization processes. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
5.
6.
Y el-Shabrawi C Livir-Rallatos W Christen S Baltatzis CS Foster 《Canadian Metallurgical Quarterly》1998,105(9):1659-1663
OBJECTIVE: This study aimed to investigate the role of interleukin-12 (IL-12) and interleukin-10 (IL-10) in initiation and maintenance of intraocular inflammation. DESIGN: Case series. PARTICIPANTS: Aqueous humor and vitreous levels of IL-12 and IL-10 were measured in 22 patients with uveitis undergoing cataract surgery, paracentesis of the anterior chamber, and/or vitrectomy for diagnostic reasons, and in 4 patients with cataract only. INTERVENTION: Aqueous humor and vitreous levels of IL-12 and IL-10 were measured with specific enzyme-linked immunosorbent assays. MAIN OUTCOME MEASURES: Disease activity was correlated to IL-12 levels in the aqueous humor and the vitreous of patients with uveitis. RESULTS: Cytokine levels found in the anterior chamber and the vitreous are presented in picogram/milliliter (medium; range). The highest IL-12 levels were found in patients with active uveitis (108.5 pg/ml; 72-293 pg/ml). Interleukin-12 in patients with moderate uveitis or with their disease in remission was lower (32 pg/ml; 15-94 pg/ml) than in patients with active disease (P > 0.001) but higher than in the control group (10.5 pg/ml; 9-14 pg/ml). Interleukin-10 was detectable in only 3 of 22 patients with uveitis (12 pg/ml; 9-23 pg/ml). CONCLUSION: The authors found statistically significant differences of IL-12 levels in the various patient groups (active vs. inactive vs. control). These results support the idea that these uveitis cases represent type 1 (Th1)-T lymphocyte-mediated diseases in which IL-12 plays a pivotal role in the initiation and maintenance of the intraocular inflammation. The high levels of IL-12 in the vitreous and/or aqueous humor of the patients with uveitis suggest that susceptibility or resistance to ocular autoimmunity may be connected to a genetic predisposition to an elevated Th1 response. 相似文献
7.
JW Herms J Behnke M Bergmann HJ Christen R Kolb M Wilkening E Markakis F Hanefeld HA Kretzschmar 《Canadian Metallurgical Quarterly》1997,19(6):510-515
PURPOSE: The expression of the c-erbB-2 oncogene was studied in childhood medulloblastoma to evaluate its prognostic value, which has been claimed previously. PATIENTS AND METHODS: Tumor material from 45 patients < 15 years old at diagnosis was studied using 3 monoclonal antibodies against the internal and external domains of the c-erbB-2 oncogene product. RESULTS: Six of the 45 (13%) tumor specimens were found to be positive. C-erbB-2 expression was found more often in patients < 3 years old at diagnosis (4 of 15 patients, 27%) than in older patients (2 of 30, 6.6%). During the follow-up period (5.8 +/- 2.8 years) all patients with c-erbB-2 expression died of disease (after 1.2 +/- 0.7 years). Kaplan-Meier estimation revealed a highly significant correlation of c-erbB-2 expression and survival (p = 0.002). A further study of the expression of synaptophysin and the glial fibrillary acidic protein (GFAP) in the 45 tumors revealed a negative correlation of the expression of c-erbB-2 and these proteins. CONCLUSION: C-erbB-2, which may be predominantly expressed by less differentiated tumors, was found to delineate a poorer prognostic subgroup, especially when diagnosed in patients < 3 years old. 相似文献
8.
Thomas Diemant Zhong Zhao Hubert Rauscher Joachim Bansmann R. Jürgen Behm 《Topics in Catalysis》2007,44(1-2):83-93
The interaction of CO with structurally well-defined, planar Au/TiO2 model catalysts at elevated pressures (up to 50 mbar) was studied in-situ by polarization-modulated infrared reflection absorption spectroscopy and ex-situ by X-ray photoelectron spectroscopy performed before and after CO exposure. The results indicate a CO-induced partial reduction
of the oxide surface, which is evidenced by a low frequency C–O vibration at 2060 cm−1, combined with a spreading of the Au nanoparticles due to a modification of the Au-oxide interface energy. In a 2:1 CO:O2 atmosphere, TiO2 support reduction was not observed, and a pre-reduced surface was re-oxidized. The consequences of these results for the
understanding of the CO oxidation mechanism on Au/TiO2 (model) catalysts are discussed. 相似文献
9.
Abbas Mohamed A. Christen Roland Jahns Thomas M. 《Industry Applications, IEEE Transactions on》1984,(5):1251-1259
A six-phase six-step voltage-fed induction motor is presented. The inverter is a transistorized six-step voltage source inverter, while the motor is a modified standard three-phase squirrel-cage motor. The stator is rewound with two three-phase winding sets displaced from each other by 30 electrical degrees. A model for the system is developed to simulate the drive and predict its performance. The simulation results for steady-state conditions and experimental measurements show very good correlation. It is shown that this winding configuration results in the elimination of all air-gap flux time harmonics of the order (6v ±1, v = 1,3,5,...). Consequently, all rotor copper losses produced by these harmonics as well as all torque harmonics of the order (6v, v = 1,3,5,...) are eliminated. A comparison between-the measured instantaneous torque of both three-phase and six-phase six-step voltage-fed induction machines shows the advantage of the six-phase system over the three-phase system in eliminating the sixth harmonic dominant torque ripple. 相似文献
10.
Christen K 《Environmental science & technology》2002,36(15):309A-310A