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Now showing items 161-170 of 216
Gain optimization in electrically pumped AlGaAs quantum cascade lasers
(Optical Soc Amer, Washington, 2002)
The design of the active region of a current-pumped quantum-cascade laser to achieve maximal gain is proposed. Starting with an arbitrary smooth potential, a family of isospectral Hamiltonians with a predefined energy ...
Tunneling times in complex potentials
(Elsevier, Amsterdam, 2008)
Tunneling times in absorptive media, described by complex potentials, are investigated. A general expression relating relevant tunneling times is extended by introducing a new term tau(a). For both single Dirac delta ...
Influence of nonparabolicity on tunneling times in semiconductor structures
(Elsevier Science Bv, Amsterdam, 2007)
Tunneling of a particle with energy-dependent effective mass through one-dimensional potential barrier is considered. For an arbitrary potential shape we find general relations between phase, group and dwell times, and ...
Semi-interpenetrating polymer networks composed of poly(N-isopropyl acrylamide) and polyacrylamide hydrogels
(John Wiley and Sons Inc., 2004)
Three series of semi-interpenetrating polymer networks, baaed on crosslinked poly(N-isopropyl acrylamide) (PNIPA) and 1 wt % nonionic or ionic (cationic and anionic) linear polyacrylamide (PAAm), were synthesized to improve ...
The effect of segment length on some properties of thermoplastic poly(ester-siloxane)s
(John Wiley and Sons Ltd, 2003)
A series of novel thermoplastic elastomers, based on poly(dimethylsiloxane) (PDMS) as the soft segment and poly(butylene terephthalate) (PBT) as the hard segment, were synthesized by catalyzed two-step, melt transesterification ...
Development and application of the human intestinal tract chip, a phylogenetic microarray: analysis of universally conserved phylotypes in the abundant microbiota of young and elderly adults
(Wiley-Blackwell Publishing, Inc, Malden, 2009)
P gt In this paper we present the in silico assessment of the diversity of variable regions of the small subunit ribosomal RNA (SSU rRNA) gene based on an ecosystem-specific curated database, describe a probe design procedure ...
Linking phylogenetic identities of bacteria to starch fermentation in an in vitro model of the large intestine by RNA-based stable isotope probing
(Wiley-Blackwell, Malden, 2009)
Carbohydrates, including starches, are an important energy source for humans, and are known for their interactions with the microbiota in the digestive tract. Largely, those interactions are thought to promote human health. ...
Diversity of the human gastrointestinal tract microbiota revisited
(Wiley, Hoboken, 2007)
Since the early days of microbiology, more than a century ago, representatives of over 400 different microbial species have been isolated and fully characterized from human gastrointestinal samples. However, during the ...
Clinical trial: multispecies probiotic supplementation alleviates the symptoms of irritable bowel syndrome and stabilizes intestinal microbiota
(Wiley, Hoboken, 2008)
Background Irritable bowel syndrome is the most common diagnosis in gastroenterology. Trials suggest certain probiotics to be beneficial. Aim To investigate the effects of multispecies probiotic supplementation (Lactobacillus ...
Oxidative modifications of cellulose in the periodate system - Reduction and beta-elimination reactions
(Walter de Gruyter & Co, Berlin, 2009)
The conversion of cellulose to dialdehyde cellulose (DAC) by treatment with aqueous periodate was studied by the CCOA method, which is a combination of gel permeation chromatography and carbonyl-selective fluorescence ...