Simple synthesis of photoluminescent carbon dots from a marine polysaccharide found in shark cartilage

BACKGROUND: For more than a decade, water-soluble, eco-friendly, biocompatible, and low-toxicity fluorescent nanomaterials have received considerable attention for their numerous in vivo and in vitro applications in biomedical imaging, disease diagnostics, and environmental monitoring. Owing to their tunable photoluminescence properties, carbon-based luminescent nanomaterials have shown great potential in bioimaging, photocatalysis, and biosensing among other applications. RESULTS: Marine environments provide excellent resources for the fabrication of these nanomaterials, because many marine organisms contain interesting trigger organic compounds that can be used as precursors. Herein, we synthesize multi-color emissive carbon dots (CDs) with an intrinsic photoluminescence quantum yield of 20.46%. These nanostructures were achieved through the one-step hydrothermal treatment of marine polysaccharide chondroitin sulfate, obtained from shark cartilage, in aqueous solution. CONCLUSIONS: We successfully demonstrate the low toxicity of our marine resource-derived CDs in zebrafish, and provide an initial assessment of their possible use as a bioimaging agent. Notably, the newly synthesized CDs localize in the intestines of zebrafish larvae, thereby indicating their biocompatibility and potential use as in vivo dyes.

Carbon pollution increases health inequities: lessons in resilience from the most vulnerable / La contaminación por carbono empeora las inequidades sanitarias: enseñanzas de los más vulnerables sobre la capacidad de recuperación

ABSTRACT Climate change is a social justice as well as an environmental issue. The magnitude and pattern of changes in weather and climate variables are creating differential exposures, vulnerabilities, and health risks that increase stress on health systems while exacerbating existing and creating new health inequities. Examples from national and local health adaptation projects highlight that developing partnerships across sectors and levels are critical for building climate-resilient health systems and communities. Strengthening current and implementing new health interventions, such as using environmental information to develop early warning systems, can be effective in protecting the most vulnerable. However, not all projected risks of climate change can be avoided by climate policies and programs, so health system strengthening is also critical. Applying a health inequity lens can reduce current vulnerabilities while building resilience to longer-term climate change. Taking inequities into account is critical if societies are to effectively prepare for and manage the challenges ahead.

RESUMEN El cambio climático es un asunto no solo ambiental, sino también de justicia social. La magnitud y naturaleza de los cambios observados en las variables de tiempo meteorológico y clima están llevando a exposiciones, vulnerabilidades y riesgos de salud diferenciales que incrementan la sobrecarga de los sistemas de salud y exacerban las inequidades sanitarias existentes, a la vez que generan nuevas inequidades. Los proyectos nacionales y locales de adaptación al cambio climático para proteger la salud humana ponen de manifiesto que la creación de alianzas entre diferentes sectores y en distintos niveles es fundamental para lograr que haya sistemas de salud y comunidades capaces de recuperarse de los efectos del clima. El fortalecimiento de las intervenciones de salud en curso y la aplicación de nuevas intervenciones, tales como el uso de información de tipo ambiental para crear sistemas de alerta temprana, pueden ser eficaces para proteger a los grupos más vulnerables. Sin embargo, no todos los riesgos previstos en relación con el cambio climático pueden evitarse por medio de políticas y programas climáticos, de manera que el fortalecimiento de los sistemas de salud también es fundamental. La aplicación de una óptica de inequidad sanitaria puede reducir las vulnerabilidades actuales y al mismo tiempo crear capacidad de recuperación frente a los efectos del cambio climático a más largo plazo. Si las sociedades han de prepararse para los retos que se avecinan y hacerles frente de una manera eficaz, es imprescindible que se tengan en cuenta las inequidades.

Emissões atmosféricas e implicações potenciais sobre a biota terrestre devido as atividades antrôpicas na Baía do Almirantado/Ilha Rei George - Antártica / Atmospheric emissions and potential implications on the terrestrial biota due to anthropogenic activities in Admiralty Bay/King George Island - Antarctica

Neste trabalho foi realizado um estudo sobre o impacto sobre a atmosfera e a biota terrestre devido às emissões antrópicas na Baia do Almirantado/Ilha Rei George – Antártica. Foram monitoradas as emissões dos compostos orgânicos voláteis e semi-voláteis, tanto nas fontes emissoras como no entorno da Estação Antártica Comandante Ferraz e estimadas as emissões dos navios, dos geradores a diesel e da incineração de lixo. Na avaliação do entorno, coletaram-se amostras de ar, neve e penas de aves. Com os resultados das emissões, do estudo topográfico e da meteorologia, realizou-se uma modelagem de plumas gaussiana para avaliar os impactos. Quatro cenários foram avaliados: dois com a presença dos navios NApOc Ary Rongel e Maximiano apresentaram concentrações máximas de até 356 µg m-3 de COV e 18 µg m-3 de material particulado, enquanto os demais, sem a presença dos navios, apenas considerando as estações de pesquisa EACF e Arctowski, apresentaram concentrações máximas de até 2,5 µg m-3 de COV e 1,3 µg m-3 de material particulado. Amostras de COV coletadas foram compatíveis com o cenário mais crítico. O estudo de correlação para carbonilas e HPA atmosférico e Carbono elementar e HPA, depositados em neve, apontaram a EACF como a principal fonte de emissão. As concentrações de levoglucosano detectadas a aproximadamente 2 km da EACF apontaram para a prática de incineração de lixo da EACF. Todas as áreas de interesse biológicos, anteriormente mapeados, dentro da AAEG, são vulneráveis às emissões antrópicas, como sugeriu o modelo de dispersão e a sobreposição dos resultados encontrados.

In this study it was conducted a study on the impact on the atmosphere and terrestrial biota due to anthropogenic emissions in Admiralty Bay / King George Island - Antarctica. It was monitored the emissions of volatile organic compounds and semi-volatile, both in emission sources and in the surrounding of Antarctic Station Comandante Ferraz, and estimated emissions from ships, diesel generators and waste incineration. In assessing the environment, it were collected air, snow and feathers samples. With the emissions results, meteorology database and topographical study, it was used a Gaussian plume modeling to assess impacts. Four scenarios were evaluated: the presence of two ships NApOca Ary Rongel and Maximiano had concentrations up to 356 mg m-3 for VOCs and 18 mg m-3 for particulate matter, while the other, without the presence of the vessels, only considering research stations EACF Arctowski showed concentrations of up to 2.5 mg m-3 for VOC and 1.3 mg m-3 for particulate matter. VOC samples collected were consistent with the most critical scenario. The correlation study for atmospheric carbonyls and HPA and HPA and Black Carbon, deposited on snow, EACF pointed to be the main emissions source. The levoglucosan concentrations found approximately 2 km from EACF pointed to the practice of waste incineration at EACF. All areas of biological interest, previously mapped within the AAEG are vulnerable to anthropogenic emissions, as suggested by the dispersion model and the overlap of results.

The harmful effects of air pollutants around the Yenikoy thermal power plant on architecture of Calabrian pine (Pinus brutia Ten.) needles.

The influence of air pollutants on the architecture of Calabrian pine (Pinus brutia Ten.) needles was examined in polluted and control forest sites around the Yeniköy thermal power plant (YTPP) in Muğla, Turkey. The aim of this research was to test the hypothesis that air pollutants emitted from the YTPP cause the dilation of resin canal diameter on the cross-sections of Calabrian pine needles. For this, the anatomical and morphological anomalies on the cross-sections of Calabrian pine needles were examined. It was determined that the air pollutants caused resin canal dilation and epidermis/hypodermis layers slimming on the cross-sections of Calabrian pine needles. It was also observed that the endodermis layer, the transfusion tissue cells had deformed, and the intra-cellular material had disappeared in the inner side of the cells. At the end of the land researches carried out around the YTPP, visible injury was observed and the ends of needles had withered, so the two and three-year old needles fell very early. Leak of resin on the surface of the needles especially in extensive dusty areas appeared. 0.217-0.423 mg/cm(2) fly ash on the needle surfaces in these areas were obtained. By means of the elemental analysis, it was found out that fly ash had some toxic elements on plants.

Effect of fly ash inhalation on biochemical and histomorphological changes in rat lungs.

Effect of respirable fly ash particles inhalation on lungs of rats was investigated by exposing them to respirable aerosols of size classified power plant fly ash at average concentrations of up to 14.4 +/- 1.77 mg/m3 for 4 hr/day for 28 consecutive days. A remarkable increase was found in blood eosinophil counts of fly ash exposed animals. Biochemical indicators of pulmonary damage viz. lactate dehydrogenase (cytoplasmic enzyme used as a measure of cell injury), gamma-glutamyl transferase (Clara cell damage) and alkaline phosphatase (potential measure of Type 11 cell secretions) in broncho alveolar lavage fluid (BALF) of fly ash exposed group showed significant elevation. Clumping of fly ash particles in the lungs was observed as evidenced by fly ash ladened macrophage accumulation in the alveolar region. The results suggest a damage, local inflammation and remodelling of lung as indicated by hypertrophy and hyperplasia. These changes reflect the toxic effects of the fly ash inhalation.