104 research outputs found

    BECCS potential in Brazil: Achieving negative emissions in ethanol and electricity production based on sugar cane bagasse and other residues

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    Stabilization at concentrations consistent with keeping global warming below 2 °C above the pre-industrial level will require drastic cuts in Greenhouse Gas (GHG) emissions during the first half of the century; net negative emissions approaching 2100 are required in the vast majority of current emission scenarios. For negative emissions, the focus has been on bioenergy with carbon capture and storage (BECCS), where carbon-neutral bioenergy would be combined with additional carbon capture thus yielding emissions lower than zero. Different BECCS technologies are considered around the world and one option that deserves special attention applies CCS to ethanol production. It is currently possible to eliminate 27.7 million tonnes (Mt) of CO2 emissions per year through capture and storage of CO2 released during fermentation, which is part of sugar cane-based ethanol production in Brazil. Thus, BECCS could reduce the country’s emissions from energy production by roughly 5%. Such emissions are additional to those due to the substitution of biomass-based electricity for fossil-fueled power plants. This paper assesses the potential and cost effectiveness of negative emissions in the joint production system of ethanol and electricity based on sugar cane, bagasse, and other residues in Brazil. An important benefit is that CO2 can be captured twice along the proposed BECCS supply chain (once during fermentation and once during electricity generation). This study only considers BECCS from fermentation because capturing such CO2 is straightforward, thus potentially representing a cost-effective mitigation option for Brazil compared to other alternatives. The assessment shows that fuel prices would increase by less than 3.5% due to the adoption of BECCS from fermentation, while increasing investors’ revenues are sufficient to compensate for the investment required. With appropriate government subsidies, or by sharing BECCS costs between all car fuels and all electricity supplied by hydro and bioelectricity, the increment in ethanol and electricity prices could be less than 1% for the final consumer. Meanwhile it would supply 77.3% of all cars’ fuel (private cars) and 17.9% of all electricity in Brazil

    Hepatopulmonary syndrome in patients with chronic liver disease: role of pulse oximetry

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    BACKGROUND: Hepatopulmonary syndrome (HPS) is a rare complication of liver diseases of different etiologies and may indicate a poor prognosis. Therefore, a simple non-invasive screening method to detect HPS would be highly desirable. In this study pulse oximetry was evaluated to identify patients with HPS. METHODS: In 316 consecutive patients with liver cirrhosis (n = 245), chronic hepatitis (n = 69) or non-cirrhotic portal hypertension (n = 2) arterial oxygen saturation (SaO(2)) was determined using a pulse oximeter. In patients with SaO(2 )≤92% in supine position and/or a decrease of ≥4% after change from supine to upright position further diagnostic procedures were performed, including contrast-enhanced echocardiography and perfusion lung scan. RESULTS: Seventeen patients (5.4%) had a pathological SaO(2). Four patients (1.3%) had HPS. HPS patients had a significant lower mean SaO(2 )in supine (89.7%, SD 5.4 vs. 96.0%, SD 2.3; p = 0.003) and upright position (84.3%, SD 5.0 vs. 96.0%, SD 2.4; p = 0.001) and had a lower mean PaO(2 )(56.2 mm Hg, SD 15.2 vs. 71.2 mm Hg, SD 20.2; p = 0.02) as compared to patients without HPS. The mean ΔSaO(2 )(difference between supine and upright position) was 5.50 (SD 7) in HPS patients compared to non-HPS patients who showed no change (p = 0.001). There was a strong correlation between shunt volume and the SaO(2 )values (R = -0.94). CONCLUSION: Arterial SaO(2 )determination in supine and upright position is a useful non-invasive screening test for HPS and correlates well with the intrapulmonary shunt volume

    Organometallic Complex Strongly Impairs Chikungunya Virus Entry to the Host Cells

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    Chikungunya fever is a disease caused by the Chikungunya virus (CHIKV) that is transmitted by the bite of the female of Aedes sp. mosquito. The symptoms include fever, muscle aches, skin rash, and severe joint pains. The disease may develop into a chronic condition and joint pain for months or years. Currently, there is no effective antiviral treatment against CHIKV infection. Treatments based on natural compounds have been widely studied, as many drugs were produced by using natural molecules and their derivatives. Alpha-phellandrene (α-Phe) is a naturally occurring organic compound that is a ligand for ruthenium, forming the organometallic complex [Ru2Cl4(p-cymene)2] (RcP). Organometallic complexes have shown promising as candidate molecules to a new generation of compounds that presented relevant biological properties, however, there is a lack of knowledge concerning the anti-CHIKV activity of these complexes. The present work evaluated the effects of the RcP and its precursors, the hydrate ruthenium(III) chloride salt (RuCl3⋅xH2O) (Ru) and α-Phe, on CHIKV infection in vitro. To this, BHK-21 cells were infected with CHIKV-nanoluciferase (CHIKV-nanoluc), a viral construct harboring the nanoluciferase reporter gene, at the presence or absence of the compounds for 16 h. Cytotoxicity and impact on infectivity were analyzed. The results demonstrated that RcP exhibited a strong therapeutic potential judged by the selective index > 40. Antiviral effects of RcP on different stages of the CHIKV replicative cycle were investigated; the results showed that it affected early stages of virus infection reducing virus replication by 77% at non-cytotoxic concentrations. Further assays demonstrated the virucidal activity of the compound that completely blocked virus infectivity. In silico molecular docking calculations suggested different binding interactions between aromatic rings of RcP and the loop of amino acids of the E2 envelope CHIKV glycoprotein mainly through hydrophobic interactions. Additionally, infrared spectroscopy spectral analysis indicated interactions of RcP with CHIKV glycoproteins. These data suggest that RcP may act on CHIKV particles, disrupting virus entry to the host cells. Therefore, RcP may represent a strong candidate for the development of anti-CHIKV drugs

    Using population surveys and models to reassess the conservation status of an endemic Amazonian titi monkey in a deforestation hotspot

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    Assessing the conservation status of species is essential for implementing appropriate conservation measures. A lack of evidence of threats, rather than showing an absence of impacts, could reflect a lack of studies on how human activities could result in species population declines. The range of Prince Bernhard's titi monkey Plecturocebus bernhardi is restricted to the Arc of Deforestation, a deforestation hotspot in south-eastern Amazonia. Despite this, it is categorized as Least Concern on the IUCN Red List. To reassess the conservation status of P. bernhardi, we carried out surveys during 2015–2017 to delimit the geographical distribution of the species and estimate its population density and abundance. We then used spatial predictive modelling to examine future habitat and population loss within its range. Plecturocebus bernhardi occurs over an area of 131,295 km2. Its mean group size was 2.8 individuals/group and its density 10.8 individuals/km2 and 3.8 groups/km2. Habitat loss was estimated to be 58,365 km2 (44.5% of its current range) over the next 24 years (three P. bernhardi generations) under a conservative governance model of deforestation and 105,289 km2 (80.2%) under a business-as-usual model. These numbers indicate that P. bernhardi is threatened and should be categorized as Vulnerable, at least, using the IUCN Red List criteria. We recommend the reassessment of other Least Concern primate species from the Arc of Deforestation using a similar approach
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