973 resultados para 420200 Literature Studies


Relevância:

30.00% 30.00%

Publicador:

Resumo:

The principal components, isoflavonoids and astragalosides, in the extract of Radix Astragali were detected by a high-performance liquid chromatography Couple to electrospray ionization ion trap multiple-stage tandem mass spectrometry (HPLC-ESI-IT-MSn) method. By comparing the retention time (t(R)) of HPLC, the ESI-MSn data and the structures of analyzed Compounds with the data of reference compounds and in the literature, 17 isoflavonoids and 12 astragalosides have been identified or tentatively deduced. By Virtue of the extracted ion chromatogram (EIC) mode, simultaneous determination of isoflavonoids and astragalosides could be achieved when the different components formed overlapped peaks. And this method has been utilized to analyze the constituents in extracts of Radix Astragali from Helong City and of different growth years. Then the antioxidant activity of different samples has been Successfully investigated by HPLC-ESI-MS method in multiple selected ion monitoring(MIM) mode, applying the spin trapping technology, and the Ferric Reducing Antioxidant Power (FRAP) assay was applied to support the result.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

A reversed-phase high-performance liquid chromatography-diode array detector-electrospray ionization multiple-stage tandem mass spectrometry (RP-HPLC-DAD-ESl-MSn) method has been developed for the detection and analysis of lignan constituents in the methanol extract from the fruits of Schisandra chinensis (Turcz.) Baill. RP-HPLC-DAD-ESI-MSn and electrospray ionization Fourier transform ion cyclotron resonance multiple-stage tandem mass spectrometry (ESI-FT-TCR-MSn) have been applied to investigate the characteristic product ions of four lignan reference compounds. Then, the logical fragmentation pathways of the lignans have been proposed. By comparing the retention time (t(R)) of HPLC, the ESI-MSn data and the structures of analyzed compounds with the data of reference compounds and in the literature, 11 peaks in HPLC have been unambiguously identified and another 5 peaks have been tentatively identified or deduced. Also, in the present paper, the extracted ion chromatograms (EIC) have been used to analyze the lignan isomers. The experimental results demonstrate that RP-HPLC-DAD-ESI-MSn is a specific and useful method for the identification of the lignan constituents and their isomers.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Ultra high molar mass polyethylene (UHPE) powder as polymerized in a slurry process has been studied, in its nascent state, after recrystallization on rapid cooling from the melt and after hot compression molding to a film, by DSC, effect of annealing the recrystallized specimen at 120 similar to 130 degreesC, morphology by polarizing optical microscopy and small angle X-ray scattering. Based on the experimental results obtained the macromolecular condensed state of the nascent UHPE powder is a rare case of a multi-chain condensed state of non-interpenetrating chains, involving interlaced extended chain crystalline layers and relaxed parallel chain amorphous layers. On melting, a nematic rubbery state of nanometer size domain resulted. The nematic-isotropic transition temperature was judged from literature data to be at least 220 degreesC, possibly higher than 300 degreesC, the exact temperature is however not sue because of chain degradation at such high temperatures. The recrystallization process from the melt is a crystallization from a nematic rubbery state. The drop of remelting peak temperature by 10 K of the specimen recrystallized from its melt as compared to the nascent state has its origin in the decrease both of the crystalline chain stem length and of the degree of crystallinity. The remelting peak temperature could be returned close to that of the nascent state by annealing at 120 similar to 130 degreesC.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This paper summarizes the progress of large-scale air-sea interaction studies that has been achieved in China in the four-year period from July 1998 to July 2002, including seven aspects in the area of the air-sea interaction, namely air-sea interaction related to the tropical Pacific Ocean, monsoon-related air-sea interaction, air-sea interaction in the north Pacific Ocean, air-sea interaction in the Indian Ocean, air-sea interactions in the global oceans, field experiments, and oceanic cruise surveys. However more attention has been paid to the first and the second aspects because a large number of papers in the reference literature for preparing and organizing this paper are concentrated in the tropical Pacific Ocean, such as the ENSO process with its climatic effects and dynamics, and the monsoon-related air-sea interaction. The literature also involves various phenomena with their different time and spatial scales such as intraseasonal, annual, interannual, and interdecadal variabilities in the atmosphere/ocean interaction system, reflecting the contemporary themes in the four-year period at the beginning of an era from the post-TOGA to CLIVAR studies. Apparently, it is a difficult task to summarize the great progress in this area, as it is extracted from a large quantity of literature, although the authors tried very hard.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Cryotherapy is widely used in rehabilitation; however, its effectiveness after anterior cruciate ligament (ACL) reconstruction remains uncertain. To investigate the effectiveness and safety of cryotherapy following ACL reconstruction through a systematic review, randomized and quasi-randomized clinical trials were searched in the databases: MEDLINE, EMBASE, CENTRAL PEDro, SportDiscus, CINAHL, LILACS (June 2013). the primary outcomes measures were pain, edema and adverse events; the secondary outcomes were knee function, analgesic medication use, range of motion, blood loss, hospital stay, quality of life and patient satisfaction. the methodological quality of studies was evaluated using the Cochrane Collaboration risk-of-bias tool. Ten trials (a total of 573 patients) were included. Results of meta-analysis showed that the use of cold compression devices produced a significant reduction in pain scores 48 h after surgery (p < 0.00001), compared to no cryotherapy. the risk for adverse events did not differ between patients receiving cryotherapy versus no treatment (p = 1.00). the limited evidence currently available is insufficient to draw definitive conclusions on the effectiveness of cryotherapy for other outcomes. There is a need for well designed, good quality randomized trials to answer other questions related to this intervention and increase the precision of future systematic reviews. (C) 2014 Elsevier B.V. All rights reserved.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Barry, L., Tedd, L.A. (2008). Local studies collections online: an investigation in Irish public libraries. Program: electronic library and information systems, 42(2), 163-186.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Koven, M. (2003). Folklore Studies and Popular Film and Television: A Necessary Critical Survey. Journal of American Folklore. 116(460), pp.176-195. RAE2008

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This paper presents a systematic review of the literature pertaining to orphans and vulnerable children in sub-Saharan Africa, with a particular focus on research in countries heavily impacted by HIV/AIDS. Despite study and data limitations, the literature provides evidence of growing orphan-based disparities, difficulties within households providing care, and insufficient capacity among social services. Still, additional research is urgently needed, including better OVC surveillance methods, qualitative data than answers persisting questions, the inclusion of more useful indicators in national household surveys, and longitudinal studies to determine the mechanisms by which parental HIV status and death impacts children, caregiving impacts households, and the orphan epidemic impacts communities and social systems.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The impacts of antiretroviral therapy on quality of life, mental health, labor productivity, and economic wellbeing for people living with HIV/AIDS in developing countries are only beginning to be measured. We conducted a systematic literature review to analyze the effect of antiretroviral therapy (ART) on these non-clinical indicators in developing countries and assess the state of research on these topics. Both qualitative and quantitative studies were included, as were peer-reviewed articles, gray literature, and conference abstracts and presentations. Findings are reported from 12 full-length articles, 7 abstracts, and 1 presentation (representing 16 studies). Compared to HIV-positive patients not yet on treatment, patients on ART reported significant improvements in physical, emotional and mental health and daily function. Work performance improved and absenteeism decreased, with the most dramatic changes occurring in the first three months of treatment and then leveling off. Little research has been done on the impact of ART on household wellbeing, with modest changes in child and family wellbeing within households where adults are receiving ART reported so far. Studies from developing countries have not yet assessed non-clinical outcomes of therapy beyond the first year; therefore, longitudinal outcomes are still unknown. As ART roll out extends throughout high HIV prevalence, low-resource countries and is sustained over years and decades, both positive and adverse non-clinical outcomes need to be empirically measured and qualitatively explored in order to support patient adherence and maximize treatment benefits.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Supported housing for individuals with severe mental illness strives to provide the services necessary to place and keep individuals in independent housing that is integrated into the community and in which the consumer has choice and control over his or her services and supports. Supported housing can be contrasted to an earlier model called the “linear residential approach” in which individuals are moved from the most restrictive settings (e.g., inpatient settings) through a series of more independent settings (e.g., group homes, supervised apartments) and then finally to independent housing. This approach has been criticized as punishing the client due to frequent moves, and as being less likely to result in independent housing. In the supported housing model (Anthony & Blanch, 1988) consumers have choice and control over their living environment, their treatment, and supports (e.g., case management, mental health and substance abuse services). Supports are flexible and faded in and out depending on needs. Results of this systematic review of supported housing suggest that there are several well-controlled studies of supported housing and several studies conducted with less rigorous designs. Overall, our synthesis suggests that supported housing can improve the living situation of individuals who are psychiatrically disabled, homeless and with substance abuse problems. Results show that supported housing can help people stay in apartments or homes up to about 80% of the time over an extended period. These results are contrary to concerns expressed by proponents of the linear residential model and housing models that espoused more restrictive environments. Results also show that housing subsidies or vouchers are helpful in getting and keeping individuals housed. Housing services appear to be cost effective and to reduce the costs of other social and clinical services. In order to be most effective, intensive case management services (rather than traditional case management) are needed and will generally lead to better housing outcomes. Having access to affordable housing and having a service system that is well-integrated is also important. Providing a person with supported housing reduces the likelihood that they will be re-hospitalized, although supported housing does not always lead to reduced psychiatric symptoms. Supported housing can improve clients’ quality of life and satisfaction with their living situation. Providing supported housing options that are of decent quality is important in order to keep people housed and satisfied with their housing. In addition, rapid entry into housing, with the provision of choices is critical. Program and clinical supports may be able to mitigate the social isolation that has sometimes been associated with supported housing.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

A detailed series of simulation chamber experiments has been performed on the atmospheric degradation pathways of the primary air pollutant naphthalene and two of its photooxidation products, phthaldialdehyde and 1-nitronaphthalene. The measured yields of secondary organic aerosol (SOA) arising from the photooxidation of naphthalene varied from 6-20%, depending on the concentrations of naphthalene and nitrogen oxides as well as relative humidity. A range of carbonyls, nitro-compounds, phenols and carboxylic acids were identified among the gas- and particle-phase products. On-line analysis of the chemical composition of naphthalene SOA was performed using aerosol time-of-flight mass spectrometry (ATOFMS) for the first time. The results indicate that enhanced formation of carboxylic acids may contribute to the observed increase in SOA yields at higher relative humidity. The photolysis of phthaldialdehyde and 1-nitronaphthalene was investigated using natural light at the European Photoreactor (EUPHORE) in Valencia, Spain. The photolysis rate coefficients were measured directly and used to confirm that photolysis is the major atmospheric loss process for these compounds. For phthaldialdehyde, the main gas-phase products were phthalide and phthalic anhydride. SOA yields in the range 2-11% were observed, with phthalic acid and dihydroxyphthalic acid identified among the particle phase products. The photolysis of 1-nitronaphthalene yielded nitric oxide and a naphthoxy radical which reacted to form several products. SOA yields in the range 57-71% were observed, with 1,4-naphthoquinone, 1-naphthol and 1,4-naphthalenediol identified in the particle phase. On-line analysis of the SOA generated in an indoor chamber using ATOFMS provided evidence for the formation of high-molecular-weight products. Further investigations revealed that these products are oxygenated polycyclic compounds most likely produced from the dimerization of naphthoxy radicals. These results of this work indicate that naphthalene is a potentially large source of SOA in urban areas and should be included in atmospheric models. The kinetic and mechanistic information could be combined with existing literature data to produce an overall degradation mechanism for naphthalene suitable for inclusion in photochemical models that are used to predict the effect of emissions on air quality.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Based on the experience that today's students find it more difficult than students of previous decades to relate to literature and appreciate its high cultural value, this paper argues that too little is known about the actual teaching and learning processes which take place in literature courses and that, in order to ensure the survival of literary studies in German curricula, future research needs to elucidate for students, the wider public and, most importantly, educational policy makers, why the study of literature should continue to have an important place in modern language curricula. Contending that students' willingness to engage with literature will, in the future, depend to a great extent on the use of imaginative methodology on the part of the teacher, we give a detailed account of an action research project carried out at University College Cork from October to December 2002 which set out to explore the potential of a drama in education approach to the teaching and learning of foreign language literature. We give concrete examples of how this approach works in practice, situate our approach within the subject debate surrounding Drama and the Language Arts and evaluate in detail the learning processes which are typical of performance-based literature learning. Based on converging evidence from different data sources and overall very positive feedback from students, we conclude by recommending that modern language departments introduce courses which offer a hands-on experience of literature that is different from that encountered in lectures and teacher-directed seminars.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In this short paper, we have gone through some key results of monetary policy research applied for the Vietnamese economy, over the past 20 years after Doi Moi, together with a few caveats when putting these results in use. We look at different research themes, and suggest that future research make better and more diverse choice of analytic framework, and also put macro and micro-setting connection at work, which appear to likely bring about better and more insightful results for the monetary economics literature in Vietnam.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The potential of the violoncello as a solo instrument was recognized and supported by cellists such as Luigi Boccherini (1743-1805), Luis Duport (1749-1819), Auguste Franchomme (1808-1884), and Alfredo Piatti (1822-1901). These pioneers composed technically demanding etudes, exercises, and caprices for the cello that were comparable to those already present in the violin literature. Even so, in the late nineteenth century and early twentieth century, considerably fewer substantial works were brought forth for the cello as compared with the violin. Consequently, many cellists such as Luigi Silva (1903-1961), Gregor Piatigorsky (1903-1976), Pierre Fournier (1906-1986), and Janos Starker (b. 1924) selected notable pieces from the violin repertoire and transcribed these for the cello. Some composers themselves actually adapted for the cello their own works originally written for the violin. Johannes Brahms with his Violin Sonata Op. 78, Igor Stravinsky with his Suite Italienne, and Béla Bartók with his First Rhapsody all belong to this category. Adaptations such as these further raised awareness among composers and performers of the possibilities of the cello as an independent and expressive instrument. Thus, many composers from the early 1900s to the present were encouraged to write increasing numbers of more soloistic and demanding works for cello. Herein, I explore the repertoire of cello transcriptions in order to analyze the differences between the original and transcribed versions and the challenges found therein. The performer may attempt to recreate the effect originally intended for the violin or, more daringly, may strive to search for alternate presentations of the music more suitable and expressive of the cello's own character. The project includes two recitals of the following transcribed works presented at the University of Maryland College Park, School of Music: Sonata in A by César Franck, transcribed by Jules Delsart, Variations on a Theme from Rossini by Nicolo Paganini, transcribed by Fournier, Suite Italienne by Igor Stravinsky, transcribed with the help of Piatigorsky, Sonatina Op. 137, No. 1 by Franz Schubert, transcribed by Starker, First Rhapsody by Béla Bartók and Sonata, Op. 108 by Johannes Brahms, transcribed by Hsiao-mei Sun.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

INTRODUCTION: Accessing new knowledge as the evidence base for hospice and palliative care grows has specific challenges for the discipline. This study aimed to describe conversion rates of palliative and hospice care conference abstracts to journal articles and to highlight that some palliative care literature may not be retrievable because it is not indexed on bibliographic databases. METHODS: Substudy A tracked the journal publication of conference abstracts selected for inclusion in a gray literature database on www.caresearch.com.au . Abstracts were included in the gray literature database following handsearching of proceedings of over 100 Australian conferences likely to have some hospice or palliative care content that were held between 1980 and 1999. Substudy B looked at indexing from first publication until 2001 of three international hospice and palliative care journals in four widely available bibliographic databases through systematic tracing of all original papers in the journals. RESULTS: Substudy A showed that for the 1338 abstracts identified only 15.9% were published (compared to an average in health of 45%). Published abstracts were found in 78 different journals. Multiauthor abstracts and oral presentations had higher rates of conversion. Substudy B demonstrated lag time between first publication and bibliographic indexing. Even after listing, idiosyncratic noninclusions were identified. DISCUSSION: There are limitations to retrieval of all possible literature through electronic searching of bibliographic databases. Encouraging publication in indexed journals of studies presented at conferences, promoting selection of palliative care journals for database indexing, and searching more than one bibliographic database will improve the accessibility of existing and new knowledge in hospice and palliative care.