213 research outputs found

    Cortical Cataract and Refractive Error

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    Purpose: To evaluate the relationship between the presence of cortical cataract and accommodation effort, using refractive error as a proxy. Methods: Patients between 50 and 90 years, scheduled for cataract surgery, were selected with the help of a photographic database. Nuclear and cortical cataract were graded and patients grouped having no cataract, pure cortical, mixed or pure nuclear cataract. Refraction data at the time of the photograph was converted to estimated spherical equivalent refractive error each patient would have had at the age of 45 years. Results: From the initial 239 eyes from 239 patients, cases with myopia below –6.5 dpt and hyperopia above 6.5 dpt were excluded, resulting in 199 cases for final analysis. Eyes with no cataract showed the lowest median refractive error (–3.65 dpt), followed by the pure nuclear group (–2.69 dpt). The median refractive error for pure cortical (–0.23 dpt) and mixed cataracts (–0.87 dpt) were close to emmetropia. Cortical cataracts were found in 37% of myopes, 82% of emmetropes, and 85% of hyperopes. Conclusion: Emmetropes and hyperopes tend to develop more cortical cataract than myopes. These cortical cataracts might be caused by shear stress inside the crystalline lens due to accommodation efforts at the time of onset of presbyopia

    The effect of thermal treatment on structure and surface composition of PtCo electro-catalysts for application in PEMFCs operating under automotive conditions

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    Ontem, como aqui escrevi, JosÊ Eduardo Moniz, Director-Geral da TVI, fez uma conferência intitulada A Televisão num Mundo Audiovisual em Mudança na UCP. No vídeo, Moniz fala de seis assuntos: 1) televisão generalista e novas plataformas, 2) perfil de oferta para o telespectador, 3) surgimento do quinto canal, 4) três canais de notícias, 5) programação de qualidade, e 6) blocos informativos

    Protecting Important Sites for Biodiversity Contributes to Meeting Global Conservation Targets

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    Abstract Protected areas (PAs) are a cornerstone of conservation efforts and now cover nearly 13% of the world's land surface, with the world's governments committed to expand this to 17%. However, as biodiversity continues to decline, the effectiveness of PAs in reducing the extinction risk of species remains largely untested. We analyzed PA coverage and trends in species' extinction risk at globally significant sites for conserving birds (10,993 Important Bird Areas, IBAs) and highly threatened vertebrates and conifers (588 Alliance for Zero Extinction sites, AZEs) (referred to collectively hereafter as 'important sites'). Species occurring in important sites with greater PA coverage experienced smaller increases in extinction risk over recent decades: the increase was half as large for bird species with.50% of the IBAs at which they occur completely covered by PAs, and a third lower for birds, mammals and amphibians restricted to protected AZEs (compared with unprotected or partially protected sites). Globally, half of the important sites for biodiversity conservation remain unprotected (49% of IBAs, 51% of AZEs). While PA coverage of important sites has increased over time, the proportion of PA area covering important sites, as opposed to less important land, has declined (by 0.45-1.14% annually since 1950 for IBAs and 0.79-1.49% annually for AZEs). Thus, while appropriately located PAs may slow the rate at which species are driven towards extinction, recent PA network expansion has under-represented important sites. We conclude that better targeted expansion of PA networks would help to improve biodiversity trends

    Protecting Important Sites for Biodiversity Contributes to Meeting Global Conservation Targets

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    Abstract Protected areas (PAs) are a cornerstone of conservation efforts and now cover nearly 13% of the world's land surface, with the world's governments committed to expand this to 17%. However, as biodiversity continues to decline, the effectiveness of PAs in reducing the extinction risk of species remains largely untested. We analyzed PA coverage and trends in species' extinction risk at globally significant sites for conserving birds (10,993 Important Bird Areas, IBAs) and highly threatened vertebrates and conifers (588 Alliance for Zero Extinction sites, AZEs) (referred to collectively hereafter as 'important sites'). Species occurring in important sites with greater PA coverage experienced smaller increases in extinction risk over recent decades: the increase was half as large for bird species with.50% of the IBAs at which they occur completely covered by PAs, and a third lower for birds, mammals and amphibians restricted to protected AZEs (compared with unprotected or partially protected sites). Globally, half of the important sites for biodiversity conservation remain unprotected (49% of IBAs, 51% of AZEs). While PA coverage of important sites has increased over time, the proportion of PA area covering important sites, as opposed to less important land, has declined (by 0.45-1.14% annually since 1950 for IBAs and 0.79-1.49% annually for AZEs). Thus, while appropriately located PAs may slow the rate at which species are driven towards extinction, recent PA network expansion has under-represented important sites. We conclude that better targeted expansion of PA networks would help to improve biodiversity trends

    A Comparative Environmental Assessment for the Synthesis of 1,3-Oxazin-2-one by Metrics: Greenness Evaluation and Blind Spots

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    Alternative syntheses for the production of 3-benzyl-1,3-oxazinan-2-one are compared and evaluated employing green metrics. An environmental assessment has been performed using the algorithm recently developed by Andraos that takes into account the mass flows and the software EATOS that considers mass flows, environmental impacts of the substances involved, and waste produced. Strengths and critical spots of the environmental tools employed are also discussed. Data collected showed that the synthesis employing diethyl carbonate is the most promising one, having the lowest environmental impact

    Chemical Behavior and Reaction Kinetics of Sulfur and Nitrogen Half-Mustard and Iprit Carbonate Analogues

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    Sulfur and nitrogen mustards are very toxic, yet versatile organic molecules with numerous applications. Herein, we report on a synthesis of a new class of green compounds, i.e., half-mustard and iprit carbonates, that result in new, unexplored, and safe molecules. Their chemical behavior with several nucleophiles and their reaction kinetics have been investigated

    One-step hydrothermal synthesis of graphene decorated V2O5 nanobelts for enhanced electrochemical energy storage

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    Graphene-decorated V2O5 nanobelts (GVNBs) were synthesized via a low-temperature hydrothermal method in a single step. V2O5 nanobelts (VNBs) were formed in the presence of graphene oxide, a mild oxidant, which also enhanced the conductivity of GVNBs. From the electron energy loss spectroscopy analysis, the reduced graphene oxide (rGO) are inserted into the layered crystal structure of V2O5 nanobelts, which further confirmed the enhanced conductivity of the nanobelts. The electrochemical energy-storage capacity of GVNBs was investigated for supercapacitor applications. The specific capacitance of GVNBs was evaluated using cyclic voltammetry (CV) and charge/discharge (CD) studies. The GVNBs having V2O5-rich composite, namely, V(3)G(1) (VO/GO = 3:1), showed superior specific capacitance in comparison to the other composites (V(1)G(1) and V(1)G(3)) and the pure materials. Moreover, the V(3)G(1) composite showed excellent cyclic stability and the capacitance retention of about 82% was observed even after 5000 cycles.open

    Protecting Important Sites for Biodiversity Contributes to Meeting Global Conservation Targets

    Get PDF
    Protected areas (PAs) are a cornerstone of conservation efforts and now cover nearly 13% of the world's land surface, with the world's governments committed to expand this to 17%. However, as biodiversity continues to decline, the effectiveness of PAs in reducing the extinction risk of species remains largely untested. We analyzed PA coverage and trends in species' extinction risk at globally significant sites for conserving birds (10,993 Important Bird Areas, IBAs) and highly threatened vertebrates and conifers (588 Alliance for Zero Extinction sites, AZEs) (referred to collectively hereafter as ‘important sites’). Species occurring in important sites with greater PA coverage experienced smaller increases in extinction risk over recent decades: the increase was half as large for bird species with>50% of the IBAs at which they occur completely covered by PAs, and a third lower for birds, mammals and amphibians restricted to protected AZEs (compared with unprotected or partially protected sites). Globally, half of the important sites for biodiversity conservation remain unprotected (49% of IBAs, 51% of AZEs). While PA coverage of important sites has increased over time, the proportion of PA area covering important sites, as opposed to less important land, has declined (by 0.45–1.14% annually since 1950 for IBAs and 0.79–1.49% annually for AZEs). Thus, while appropriately located PAs may slow the rate at which species are driven towards extinction, recent PA network expansion has under-represented important sites. We conclude that better targeted expansion of PA networks would help to improve biodiversity trends

    VLPs and particle strategies for cancer vaccines

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