171 research outputs found
Phonitons as a sound-based analogue of cavity quantum electrodynamics
A quantum mechanical superposition of a long-lived, localized phonon and a
matter excitation is described. We identify a realization in strained silicon:
a low-lying donor transition (P or Li) driven solely by acoustic phonons at
wavelengths where high-Q phonon cavities can be built. This phonon-matter
resonance is shown to enter the strongly coupled regime where the "vacuum" Rabi
frequency exceeds the spontaneous phonon emission into non-cavity modes, phonon
leakage from the cavity, and phonon anharmonicity and scattering. We introduce
a micropillar distributed Bragg reflector Si/Ge cavity, where Q=10^5-10^6 and
mode volumes V<=25*lambda^3 are reachable. These results indicate that single
or many-body devices based on these systems are experimentally realizable.Comment: Published PRL version. Note that the previous arXiv version has more
commentary, figures, etc. Also see http://research.tahan.com
Time course of collagen peak in bile duct-ligated rats
<p>Abstract</p> <p>Background</p> <p>One of the most useful experimental fibrogenesis models is the "bile duct-ligated rats". Our aim was to investigate the quantitative hepatic collagen content by two different methods during the different stages of hepatic fibrosis in bile duct-ligated rats on a weekly basis. We questioned whether the 1-wk or 4-wk bile duct-ligated model is suitable in animal fibrogenesis trials.</p> <p>Methods</p> <p>Of the 53 male Wistar rats, 8 (Group 0) were used as a healthy control group. Bile duct ligation (BDL) had been performed in the rest. Bile duct-ligated rates were sacrificed 7 days later in group 1 (10 rats), 14 days later in group 2 (9 rats), 21 days later in group 3(9 rats) and 28 days later in group 4 (9 rats). Eight rats underwent sham-operation (Sham). Hepatic collagen measurements as well as serum levels of liver enzymes and function tests were all analysed.</p> <p>Results</p> <p>The peak level of collagen was observed biochemically and histomorphometricly at the end of third week (P < 0.001 and P < 0.05). Suprisingly, collagen levels had decreased with the course of time such as at the end of fourth week (P < 0.01 and P < 0.05).</p> <p>Conclusion</p> <p>We have shown that fibrosis in bile duct-ligated rats is transient, i.e. reverses spontaneously after 3 weeks. This contrasts any situation in patients where hepatic fibrosis is progressive and irreversible as countless studies performed by many investigators in the same animal model.</p
Coulomb Blockade in a Silicon/Silicon-Germanium Two-Dimensional Electron Gas Quantum Dot
We report the fabrication and electrical characterization of a single
electron transistor in a modulation doped silicon/silicon-germanium
heterostructure. The quantum dot is fabricated by electron beam lithography and
subsequent reactive ion etching. The dot potential and electron density are
modified by laterally defined side gates in the plane of the dot. Low
temperature measurements show Coulomb blockade with a single electron charging
energy of 3.2 meV.Comment: Typos corrected; to appear in Appl. Phys. Let
Case management in oncology rehabilitation (CAMON): The effect of case management on the quality of life in patients with cancer after one year of ambulant rehabilitation. A study protocol for a randomized controlled clinical trial in oncology rehabilitation
Background Cancer diseases and their therapies have negative effects on the quality of life. The aim of this study is to assess the effectiveness of case management in a sample of oncological outpatients with the intent of rehabilitation after cancer treatment. Case management wants to support the complex information needs of the patients in addition to the segmented structure of the health care system. Emphasis is put on support for self-management in order to enhance health - conscious behaviour, learning to deal with the burden of the illness and providing the opportunity for regular contacts with care providers. We present a study protocol to investigate the efficacy of a case management in patients following oncology rehabilitation after cancer treatment. Methods The trial is a multicentre, two-arm randomised controlled study. Patients are randomised parallel in either 'usual care' plus case management or 'usual care' alone. Patients with all types of cancer can be included in the study, if they have completed the therapy with chemo- and/or radiotherapy/surgery with curative intention and are expected to have a survival time >1 year. To determine the health-related quality of life the general questionnaire FACT G is used. The direct correlation between self-management and perceived self-efficacy is measured with the Jerusalem & Schwarzer questionnaire. Patients satisfaction with the care received is measured using the Patient Assessment of Chronic Illness Care 5 As (PACIC-5A). Data are collected at the beginning of the trial and after 3, 6 and 12 months. The power analysis revealed a sample size of 102 patients. The recruitment of the centres began in 2009. The inclusion of patients began in May 2010. Discussion Case management has proved to be effective regarding quality of life of patients with chronic diseases. When it comes to oncology, case management is mainly used in cancer treatment, but it is not yet common in the rehabilitation of cancer patients. Case management in oncology rehabilitation is not well-established in Switzerland. A major challenge of the study will therefore probably be the recruitment of the patients due to the physicians' and patients' scarcely existing awareness of this issue
AGRIFIS - simulador de prospecção de cenários e avaliação de projetos de produção de sementes, óleo in natura e biodiesel de mamona.
Este trabalho propõe um modelo de prospecção de cenários e avaliação de projetos de atividades econômicas de produção agrícola de mamona caracterizada como agricultura familiar, extração de óleo vegetal in natura de sementes de mamona e produção de biodiesel (transesterificação), na forma de cadeia produtiva integrada. O modelo utiliza indicadores de avaliação econômico-flnanceiro, ambiental e social, como por exemplo, VPL, TIR, PBS, PBD, custo de produção, renda familiar, número de famílias assentadas e funcionários empregados, e outros, para identificar o desempenho de cada proposta de projeto. Para tanto, foi desenvolvido um ambiente computacional "AGRIFIS" para abrigar o modelo proposto nesse trabalho, que é uma ferramenta de apoio à tomada de decisão para investimentos em cadeia produtiva de mamona, pois se pode estimar o fluxo de caixa futuro de uma determinada proposta de projeto, incluindo as lucratividades, as despesas, a rentabilidade das famílias assentadas para determinadas condições pré-estabelecidas
Proposta de desenvolvimento regional sustentável no semi-árido promovido por agente do setor elétrico.
Este trabalho sugere uma proposta de desenvolvimento regional sustentável no semiárido nordestino brasileiro promovido por termelétricas convencionais já instaladas e operando atualmente com combustíveis não-renováveis (diesel ou óleo mineral pesada). A proposta está formatada num modelo de cadeia produtiva de oleaginosa composta por processo seqüencial de produção agrícola caracterizada com agricultura familiar, extração de óleo vegetal in natura das sementes de mamona e conversão em biodiesel e, finalmente, aplicação de misturas de óleos de origem vegetal adlcloaados aos atuais combustíveis de termelétricas para geração de eletricidade. Os resultados dessa aplicação são geradores tornando-se agentes de desenvolvimento sustentável sobre os aspectos econômicos, sociais e ambientais, como: estímulo da economia local; a promoção de geração de emprego e renda para a comunidade local; fixação do homem no campo; minimização de emissão de gás de efeito estufa, geração de energia limpa e renovável e etc
Developmenrt of EST-SSR and genomic-SSR markers to assess genetic diversity in Jatropha Curcas L.
<p>Abstract</p> <p>Background</p> <p><it>Jatropha curcas L. </it>has attracted a great deal of attention worldwide, regarding its potential as a new biodiesel crop. However, the understanding of this crop remains very limited and little genomic research has been done. We used simple sequence repeat (SSR) markers that could be transferred from <it>Manihot esculenta </it>(cassava) to analyze the genetic relationships among 45 accessions of <it>J. curcas </it>from our germplasm collection.</p> <p>Results</p> <p>In total, 187 out of 419 expressed sequence tag (EST)-SSR and 54 out of 182 genomic (G)-SSR markers from cassava were polymorphic among the <it>J. curcas </it>accessions. The EST-SSR markers comprised 26.20% dinucleotide repeats, 57.75% trinucleotide repeats, 7.49% tetranucleotide repeats, and 8.56% pentanucleotide repeats, whereas the majority of the G-SSR markers were dinucleotide repeats (62.96%). The 187 EST-SSRs resided in genes that are involved mainly in biological and metabolic processes. Thirty-six EST-SSRs and 20 G-SSRs were chosen to analyze the genetic diversity among 45 <it>J. curcas </it>accessions. A total of 183 polymorphic alleles were detected. On the basis of the distribution of these polymorphic alleles, the 45 accessions were classified into six groups, in which the genotype showed a correlation with geographic origin. The estimated mean genetic diversity index was 0.5572, which suggests that our <it>J. curcas </it>germplasm collection has a high level of genetic diversity. This should facilitate subsequent studies on genetic mapping and molecular breeding.</p> <p>Conclusion</p> <p>We identified 241 novel EST-SSR and G-SSR markers in <it>J. curcas</it>, which should be useful for genetic mapping and quantitative trait loci analysis of important agronomic traits. By using these markers, we found that the intergroup gene diversity of <it>J. curcas </it>was greater than the intragroup diversity, and that the domestication of the species probably occurred partly in America and partly in Hainan, China.</p
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