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361.
Julie Charpentier Francis Voirol Felix Flachsmann Silvia Tanner Natalie Aeberli Gerhard Brunner Andreas Goeke 《Helvetica chimica acta》2020,103(12):e2000175
A low-valent cobalt(I) complex, formed from the reduction of CoBr2(dppe) with zinc, acts as catalyst for the efficient [2+4] cycloaddition of β-alkyl, cycloalkyl and aryl substituted propiolates to dienes. This transformation yields synthetically relevant 1,4-cyclohexadiene carboxylates in good to excellent yields. Furthermore, the target compounds are novel lead structures for the discovery of fragrance ingredients from the fruity, floral and spicy odor family. 相似文献
362.
Laura Beth J. McIntire Natalie Landman Min Suk Kang Gina M. Finan Jeremy C. Hwang Ann Z. Moore Lydia S. Park Chyuan-Sheng Lin Tae-Wan Kim 《Chemistry & biology》2013,20(7):956-967
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363.
Arto Heiskanen Vasile Coman Natalie Kostesha David Sabourin Nick Haslett Keith Baronian Lo Gorton Martin Dufva Jenny Emnéus 《Analytical and bioanalytical chemistry》2013,405(11):3847-3858
Conventionally, microbial bioelectrochemical assays have been conducted using immobilized cells on an electrode that is placed in an electrochemical batch cell. In this paper, we describe a developed microfluidic platform with integrated microelectrode arrays for automated bioelectrochemical assays utilizing a new double mediator system to map redox metabolism and screen for genetic modifications in Saccharomyces cerevisiae cells. The function of this new double mediator system based on menadione and osmium redox polymer (PVI-Os) is demonstrated. “Wiring” of S. cerevisiae cells using PVI-Os shows a significant improvement of bioelectrochemical monitoring in a microfluidic environment and functions as an effective immobilization matrix for cells that are not strongly adherent. The function of the developed microfluidic platform is demonstrated using two strains of S. cerevisiae, ENY.WA and its deletion mutant EBY44, which lacks the enzyme phosphoglucose isomerase. The cellular responses to introduced glucose and fructose were recorded for the two S. cerevisiae strains, and the obtained results are compared with previously published work when using an electrochemical batch cell, indicating that microfluidic bioelectrochemical assays employing the menadione–PVI-Os double mediator system provides an effective means to conduct automated microbial assays. Figure
Microfluidic platform for bioelectrochemical assays using osmium redox polymer “wired” living yeast cells 相似文献
364.
Paquin F Latini G Sakowicz M Karsenti PL Wang L Beljonne D Stingelin N Silva C 《Physical review letters》2011,106(19):197401
We probe charge photogeneration and subsequent recombination dynamics in neat regioregular poly(3-hexylthiophene) films over six decades in time by means of time-resolved photoluminescence spectroscopy. Exciton dissociation at 10 K occurs extrinsically at interfaces between molecularly ordered and disordered domains. Polaron pairs thus produced recombine by tunneling with distributed rates governed by the distribution of electron-hole radii. Quantum-chemical calculations suggest that hot-exciton dissociation at such interfaces results from a high charge-transfer character. 相似文献
365.
366.
V. Gomer B. Ueberholz S. Knappe F. Strauch D. Frese D. Meschede 《Applied physics. B, Lasers and optics》1998,67(6):689-697
Received: 4 September 1998 相似文献
367.
Optical data communication will play an important role in future high speed data links. Especially in Datacom applications data rates in Gbps area will be desired. An overall low cost approach is needed on both sides, for the opto-electronic integration and for the passive optical interconnects. Opto-electronic integration will be reached through the use of one- or bidirectional transceivers for Datacom based - in future - on surface emitting lasers (VCSEL), instead of LEDs used today, and economically favorable silicon detectors. This additionally requires passive optical interconnects using beam shaped low-cost micro-optical components such as, microlenses for in- and out-coupling which are more and more popular in recently developed opto-electronic devices.Ideally, micro-optical components can be integrated in passive optical interconnects and replicated in polymer materials for the cost reducing. Hence, the increase of data rate depends on the quality of the optical surfaces. In this paper the micromechanical manufacturing technologies of microcomponents with optical surfaces are discussed. Furthermore, polymer based components are presented which can be used for coupling and routing of optical signals, e.g. a passive optical interconnect for the passive coupling into photodiode or from VCSEL and optical N × M star couplers. The polymer based interconnect module has been realized in different polymers (polymethyl methacrylate, PMMA, and cycloolefin copolymer, COC). Total loses and data rates achieved are 3.3 dB and 2 Gbps, respectively. Average total loss an e.g., polymer based 16 × 16 optical star coupler is better than 17 dB per channel with a uniformity of 3 dB. For replication of polymer substrates of these components hot embossing tools have been produced by combination of deep lithography, ultra-precise milling and micro-machining. 相似文献
368.
369.
A relatively fast, simple and very selective liquid chromatography-tandem mass spectrometry (LC-MS-MS) method for the detection of flunixin, its 5-hydroxymetabolite and ketoprofen in raw milk has been developed and validated. After a simple extraction with acetonitrile and partial evaporation of the organic phase, the extract was filtered and directly injected into the LC-MS-MS system on a Symmetry C18 column. The parent ions were selected for further fragmentation with argon. The method developed was partially validated according to Commission Decision 2002/657/EC [Commission Decision 2002/657/EC implementing Council Directive 96/23/EC concerning the performance of analytical methods and the interpretation of results]. The validation parameters were linearity, specificity, repeatability, recovery and decision limit (CCα). CCα varied from 0.5 μg kg−1 for flunixin and 5-hydroxyflunixin to 1 μg kg−1 for ketoprofen.Holstein-Friesian cows were given either Ketofen® or Finadyne® via an intravenous injection at the maximum dose as written in the instructions. Cows were milked twice a day and all samples were analysed by the method described. The highest concentrations found for ketoprofen, flunixin and 5-hydroxyflunixin were 2.5, 6.7 and 590 μg l−1, respectively. The concentration of 5-hydroxyflunixin declined rapidly to concentrations below the MRL value of 40 μg l−1. It can be concluded that the withdrawal time proposed by the pharmaceutical companies, 12 h after the last dosing, is acceptable for both compounds. 相似文献
370.
Hitoshi Sato Anurag Tyagi Hong Zhong Natalie Fellows Roy B. Chung Makoto Saito Kenji Fujito James S. Speck Steven P. DenBaars Shuji Nakamura 《固体物理学:研究快报》2007,1(4):162-164
We demonstrate a high power green InGaN/GaN multiple‐quantum‐well (MQW) light emitting diode (LED) with a peak emission wavelength of 516 nm grown on low extended defect density semipolar (11 2) bulk GaN substrate by metal organic chemical vapor deposition. The output power and external quantum efficiency (EQE) at drive currents of 20 and 100 mA under direct current (DC) operation were 5.0 mW, 10.5% and 15.6 mW, 6.3%, respectively. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献