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981.
Mario Frahm Thorsten von Drathen Lisa Marie Gronbach Alice Voss Felix Lorenz Jonas Bresien Alexander Villinger Frank Hoffmann Prof. Dr. Malte Brasholz 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(30):12550-12554
Tetrahydrocarbazoles and perhydrocyclohepta[b]indoles undergo a catalytic cascade singlet oxygenation in alkaline medium, which leads to chiral tricyclic perhydropyrido- and perhydroazepino[1,2-a]indoles in a single operation. These photooxygenation products are new synthetic equivalents of uncommon C,N-diacyliminium ions and can be functionalized with the aid of phosphoric acid organocatalysis. 相似文献
982.
Gregory B. Kharas Lisa M. Gennett Yolondria L. Harvey Elizabeth R. Jennings Denny Petropoulos Ovie C. Smith 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(3):163-167
Novel trisubstituted ethylenes, chlorine ring-substituted 2-cyano-3-phenyl-2-propenamides, RC6H3CH?C(CN)CONH2 (where R is 2,3-dichloro, 2,4-dichloro, 2,6-dichloro, 3,4-dichloro, 2-chloro-5-nitro, 4-chloro-3-nitro, 5-chloro-2-nitro) were synthesized by potassium hydroxide catalyzed Knoevenagel condensation of ring-substituted benzaldehydes and cyanoacetamide and characterized by CHN elemental analysis, IR, 1H- and 13C-NMR. Novel copolymers of the ethylenes and styrene were prepared at equimolar monomer feed composition by solution in the presence of a radical initiation (AIBN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1H- and 13C-NMR, GPC, DSC, and TGA. Thus, the order of relative reactivity (1/r1) and the tendency toward alternation of monomer units in the copolymer for the monomers is 2-Cl-5-NO2 (3.09) > 5-Cl-2-NO2 (1.88) > 4-Cl-3-NO2 (0.97) > 2,6-Cl2 (0.93) > 3,4-Cl2 (0.31) > 2,4-Cl2 (0.30) > 2,3-Cl2 (0.22). High Tg of the copolymers in comparison with that of polystyrene indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 200–500°C range with residue (3.5–5.0 wt%), which then decomposed in the 500–800°C range. 相似文献
983.
984.
Lisa C. Shriver-Lake Joel Golden Laura Bracaglia Frances S. Ligler 《Analytical and bioanalytical chemistry》2013,405(16):5611-5614
Bacterial infection and intoxication can present with common symptoms. The ability to identify a bacteria or toxin rapidly in clinical samples is critical for administering the appropriate treatment. The microflow cytometer has previously demonstrated the ability to test for six bacteria and toxins simultaneously in buffer. In this study, the number of bacteria and toxins analyzed was increased to ten, positive and negative controls were incorporated in all assays, and most importantly, multiplexed immunoassays were demonstrated in clinical matrices. The multiplexed assays using the microflow cytometer demonstrated detection limits similar to or better than other reported antibody-based methods for pathogen detection (ELISA, lateral flow, array biosensors). In most cases, detection from complex clinical matrices (serum and nasal wash) achieved limits of detection equivalent to those for spiked buffer samples. Clinical samples spiked with bacteria and/or toxins were also analyzed successfully in blind trials. 相似文献
985.
986.
We study the phase diagram of two-flavor QCD at imaginary chemical potentials in the chiral limit. To this end we compute order parameters for chiral symmetry breaking and quark confinement. The interrelation of quark confinement and chiral symmetry breaking is analyzed with a new order parameter for the confinement phase transition. We show that it is directly related to both the quark density as well as the Polyakov loop expectation value. Our analytical and numerical results suggest a close relation between the chiral and the confinement phase transition. 相似文献
987.
Matthew Andrews Julia Chuzhoy Venkatesan Guruswami Sanjeev Khanna Kunal Talwar Lisa Zhang 《Combinatorica》2010,30(5):485-520
In the undirected Edge-Disjoint Paths problem with Congestion (EDPwC), we are given an undirected graph with V nodes, a set of terminal pairs and an integer c. The objective is to route as many terminal pairs as possible, subject to the constraint that at most c demands can be routed through any edge in the graph. When c = 1, the problem is simply referred to as the Edge-Disjoint Paths (EDP) problem. In this paper, we study the hardness of
EDPwC in undirected graphs. 相似文献
988.
Max Diem Melissa Romeo Christian Matthus Milos Miljkovic Lisa Miller Peter Lasch 《Infrared Physics & Technology》2004,45(5-6):331-338
The ability of infrared (IR) spectroscopy to distinguish and map cancerous and non-cancerous tissue has opened the question of the origin of spectral differences between normal and cancerous cells. Given the size of human cells (about 12–50 μm in diameter), IR micro-spectroscopy (IR-MSP) is an ideal tool for studying individual cells, or fractions thereof. In this contribution, the methodology for collecting IR spectra of individual cells will be explored using spectrometers that employ either synchrotron or conventional (thermal) light sources. Although synchrotron-based measurements are superior to those of conventional instruments, particularly at apertures approaching the diffraction limit, the difference in spectral quality and data acquisition time has been reduced drastically for a new generation of conventional instruments. 相似文献
989.
Fluorine-doped silica glass is an optical material with high transmission in the vacuum ultraviolet region, specifically at 157 nm. This feature, along with low thermal expansion and ease of polishing make it the material of choice for the photomask substrate for the 157 nm lithography node. We report the synthesis of fluorine-doped silica glass using various dopants. Characterization of the glasses was achieved by measuring vacuum UV and IR spectra and by refractive index measurements. Transmission and refractive index are both found to depend on fluorine concentration. 相似文献
990.