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Spectral‐converting study of Ba9–3(m+n)/2ErmYbnY2Si6O24 (m = 0.005 – 0.2, n = 0 – 0.3) orthosilicate phosphors 下载免费PDF全文
Optical materials composed of Ba9–3(m+n)/2ErmYbnY2Si6O24 (m = 0.005–0.2, n = 0–0.3) were prepared using a solid‐state reaction. The X‐ray diffraction patterns of the obtained phosphors were examined to index the peak positions. The photoluminescence (PL) excitation and emission spectra of the Er3+‐activated phosphors and the critical emission quenching as a function of Er3+ content in the Ba9–3m/2ErmY2Si6O24 structure were monitored. The spectral conversion properties of Er3+ and Er3+–Yb3+ ions doped in Ba9Y2Si6O24 phosphors were elucidated under diode‐laser irradiation at 980 nm. Up‐conversion emission spectra and the dependence of the emission intensity on pump power for the Ba8.55Er0.1Yb0.2Y2Si6O24 phosphor were investigated. The desired up‐conversion of the emitted light, which passed through the green, yellow, orange and red regions of the spectrum, was achieved through the use of appropriate Er3+ and/or Yb3+ concentrations in the host structure and 980 nm excitation light. The up‐conversion mechanism in the phosphors is described by an energy‐level schematic. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Garrick Hitchcock 《The Australian journal of anthropology》2004,15(1):107-108
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Les Hiatt 《The Australian journal of anthropology》2003,14(3):402-404
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D. N. Rana R. V. Persad M. Desai D. M. Perera H. El Teraifi J. Marshall 《Cytopathology》2003,14(Z1):5-5
Aims Table 1. . The outcome status of these women
Table 2 shows the outcome of women with borderline and mild dyskaryosis smears with or without koilocytosis. Table 2. The outcome of women with borderline and mild dyskaryosis smears with or without koilocytosis
Table 3 shows the proportion of borderline and mild dyskaryosis cervical smears with or without koilocytosis. Table 3. The proportion of borderline and mild dyskaryosis cervical smears with or without koilocytosis
Conclusions
- 1 To identify the outcome status of women with borderline and mild dyskaryosis smears.
- 2 To determine whether the presence or absence of koilocytosis influences the outcome status.
- 3 To identify the proportion of women with borderline smears showing koilocytosis.
Cytology | Outcome status | ||
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Negative (%) | Low‐grade (%) | High‐grade (%) | |
Borderline | 68 | 19 | 13 |
Mild dyskaryosis | 46 | 26 | 28 |
Koilocytosis | Outcome status | ||
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Negative (%) | Low‐grade (%) | High‐grade (%) | |
Present | 58 | 22 | 20 |
Absent | 61 | 21 | 18 |
Cytology | Koilocytosis present (%) | Koilocytosis absent (%) |
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Borderline | 24 | 76 |
Mild dyskaryosis | 34 | 66 |
- 1 Sixty‐eight per cent of women with a borderline cervical smear had a normal outcome.
- 2 Thirteen per cent of women with a borderline cervical smear developed a high‐grade lesion.
- 3 The presence or absence of koilocytosis in borderline and mild dyskaryosis cervical smears does not appear to affect the outcome status of these women.
- 4 Twenty‐four per cent of smears showing borderline nuclear changes were found to have koilocytosis.
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Carolina Giudice Badari Luis Eduardo Bernardini Danilo R. A. de Almeida Pedro H. S. Brancalion Ricardo G. Csar Victoria Gutierrez Robin L. Chazdon Haroldo B. Gomes Ricardo A. G. Viani 《Restoration Ecology》2020,28(5):1135-1144
Large‐scale forest restoration relies on approaches that are cost‐effective and economically attractive to farmers, and in this context agroforestry systems may be a valuable option. Here, we compared ecological outcomes among (1) 12–15‐year‐old coffee agroforests established with several native shade trees, (2) 12–15‐year‐old high‐diversity restoration plantations, and (3) reference old‐growth forests, within a landscape restoration project in the Pontal do Paranapanema region, in the Atlantic Forest of southeastern Brazil. We compared the aboveground biomass, canopy cover, and abundance, richness, and composition of trees, and the regenerating saplings in the three forest types. In addition, we investigated the landscape drivers of natural regeneration in the restoration plantations and coffee agroforests. Reference forests had a higher abundance of trees and regenerating saplings, but had similar levels of species richness compared to coffee agroforests. High‐diversity agroforests and restoration plantations did not differ in tree abundance. However, compared to restoration plantations, agroforests showed higher abundance and species richness of regenerating saplings, a higher proportion of animal‐dispersed species, and higher canopy cover. The abundance of regenerating saplings declined with increasing density of coffee plants, thus indicating a potential trade‐off between productivity and ecological benefits. High‐diversity coffee agroforests provide a cost‐effective and ecologically viable alternative to high‐diversity native tree plantations for large‐scale forest restoration within agricultural landscapes managed by local communities, and should be included as part of the portfolio of reforestation options used to promote the global agenda on forest and landscape restoration. 相似文献
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Health system reforms have been taken in Armenia during a time of dramatic economic and fiscal distress. It is important to assess trends in health indicators and ascertain if the changes in socio-economic systems affected the health status of infants as the most vulnerable part of the population. We find that infant mortality has fallen during the period c. 1992-2003 in spite of the difficult economic circumstances because of health-care procedures that were introduced. Particular attention is paid to the underreporting of infants' death cases in the state registration system as well as to estimating the role of different factors influencing infant mortality in Armenia. 相似文献
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Yuliang Dong Wenjuan Ding Changli Sun Xiaoqi Ji Chunyao Ling Zhenbin Zhou Zhiyun Chen Xuehong Chen Jianhua Ju 《化学与生物多样性》2020,17(4)
Two julichrome monomers, julichromes Q11 ( 1 ) and Q12 ( 2 ), along with five known julichromes (Q10, Q3 ? 5, Q3 ? 3, Q6 ? 6, Q6, 3 – 7 ) and four known anthraquinones (chrysophanol, 4‐acetylchrysophanol, islandicin, huanglongmycin A, 8 – 11 ), were isolated from the marine gastropod mollusk Batillaria zonalis‐associated Streptomyces sampsonii SCSIO 054. This is the first report of julichromes isolated from a marine source. Extensive dissection of 1D and 2D NMR datasets combined with X‐ray crystallography enabled rigorous elucidation of the previously reported configurations of julichrome Q3 ? 5 ( 4 ) and related julichrome Q3 ? 3 ( 5 ); both of the configuration at C(9) needs to be revised. In addition, julichrome Q12 ( 2 ) was found to display antibacterial activity against Micrococcus luteus and Bacillus subtilis with MICs of 2.0 and 8.0 μg mL?1; four compounds ( 1 , 3 , 6 , 7 ) also showed inhibitory activities against an array of methicillin‐resistant Staphylococcus aureus, S. aureus and S. simulans AKA1 with MIC values ranging from 8 to 64 μg mL?1. 相似文献
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The year 2010 marks the 175th anniversary of Charles Darwin’s visit to the Galapagos Islands. A recent paper by J. C. Briggs, ‘Darwin’s biogeography’ (Journal of Biogeography, 2009, 36 , 1011–1017), summarizes Darwin’s contributions to the field of biogeography, stressing the importance of his natural history specimens. Here, we illustrate how a plant collected by Darwin during his visit to Floreana and not collected since can provide insights into dispersal to oceanic islands as well as extinction of island plants, based on ancient DNA from Darwin’s herbarium specimen. 相似文献
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Martin Eisenacher Lennart Martens Harald Barsnes Tanja Hardt Michael Kohl Jari Häkkinen Rolf Apweiler Helmut E. Meyer Christian Stephan 《Proteomics》2009,9(14):3626-3629
The Proteomics Data Collection (ProDaC) consortium, a “Coordination Action” funded by the 6th EU Framework Programme, started in October 2006. Its aim was to facilitate the collection and distribution of proteomics data and the public availability of data sets from proteomics experiments. Within the consortium standard formats are created and tools are developed to allow extensive data collection within the proteomics community. An important part of ProDaC is the organization of workshops twice a year to inform about the consortium's progress and to stimulate communication between the ProDaC partners and between partners and interested members of the proteomics community. ProDaC ends on March 31, 2009. The most recent (and final) workshop was the 5th ProDaC workshop held on March 4, 2009 in Kolympari, Crete, Greece. The progress since the last meeting and an overall summary was presented by the work package coordinators and partners. Four external speakers presented talks about their work in relation to ProDaC. 相似文献
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This investigation was undertaken because biological studies to evaluate the effects of intermediate frequency magnetic fields are insufficient. White Leghorn fertile eggs (60/group) were either exposed to a 20 kHz, 1.1 mT(rms) sinusoidal magnetic field or sham‐exposed during the first 2, 7, or 11 days of embryogenesis. Lower dose exposures at 0.011 and 0.11 mT(rms) for 2 days were also conducted to elucidate possible dose–response relationships. Additional eggs given all‐trans‐retinoic acid, a teratogen, were exposed to the 1.1 mT(rms) magnetic field for the same periods to investigate the modification of embryotoxicity. After exposure, embryos were examined for mortality and developmental abnormalities. Developmental stage, number of somite pairs, and other developmental endpoints were also evaluated. Experiments were triplicated and conducted in a blind fashion. No exposure‐related changes were found in any of the endpoints in intact embryos exposed to1.1 mT(rms) or to the lower doses of 0.11 and 0.011 mT(rms) magnetic fields. Retinoic acid administration produced embryotoxic responses, which were embryonic death and developmental abnormalities, in 40–60% of embryos in the sham‐exposed groups. The magnitude of these responses was not changed significantly by the magnetic field exposures. Under the present experimental conditions, exposure to 20 kHz magnetic field up to 1.1 mT(rms) was not embryotoxic in the chick and did not potentiate the embryotoxic action of retinoic acid. Bioelectromagnetics 30:573–582, 2009. © 2009 Wiley‐Liss, Inc. 相似文献
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Pedro Luis Perez Manrique Julien Brun Ana Citlalic González‐Martínez Mariana Walter Joan Martínez‐Alier 《Journal of Industrial Ecology》2013,17(4):590-604
The biophysical features of the Argentinean economy are examined using a social metabolism approach. A material flow analysis (MFA) for this economy was conducted for the period 1970–2009. Results show that Argentina follows a resource‐intensive and export‐oriented development model with a persistent physical trade deficit. Also, Argentina's terms of trade (the average weight in tonnes of imports that can be purchased through the sale of 1 tonne of exports) show a declining trend in the period of study. Argentina's economy shows a pattern typical of countries whose economies are based primarily on exports. Comparisons between Argentina's metabolic profile and the metabolic profile of other countries in Latin America and of Australia and Spain show that the Argentinean economy presents the same pattern as other Latin American exporting economies, and its terms of trade are opposite to those of industrialized economies. 相似文献
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M. Busconi D. Rossi C. Lorenzoni G. Baldi C. Fogher 《Plant biology (Stuttgart, Germany)》2012,14(5):751-759
The weedy relative of cultivated rice, red rice, can invade and severely infest rice fields, as reported by rice farmers throughout the world. Because of its close genetic relationship to commercial rice, red rice has proven difficult to control. Clearfield (Cl) varieties, which are resistant to the inhibiting herbicides in the chemical group AHAS (acetohydroxyacid synthase), provide a highly efficient opportunity to control red rice infestations. In order to reduce the risk of herbicide resistance spreading from cultivated rice to red rice, stewardship guidelines are regularly released. In Italy, the cultivation of Cl cultivars started in 2006. In 2010, surveillance of the possible escape of herbicide resistance was carried out; 168 red rice plants were sampled in 16 fields from six locations containing Cl and traditional cultivars. A first subsample of 119 plants was analysed after herbicide treatment and the resistance was found in 62 plants. Of these 119 plants, 78 plants were randomly selected and analysed at the level of the AHAS gene to search for the Cl mutation determining the resistant genotype: the Cl mutation was present in all the resistant plants. Nuclear and chloroplast microsatellite markers revealed a high correlation between genetic similarity and herbicide resistance. The results clearly show that Cl herbicide‐resistant red rice plants are present in the field, having genetic relationships with the Cl variety. Finding plants homozygous for the mutation suggests that the crossing event occurred relatively recently and that these plants are in the F2 or later generations. These observations raise the possibility that Cl red rice is already within the cultivated rice seed supply. 相似文献