648 research outputs found

    Detection of organic compound signatures in infra-red, limb emission spectra observed by the MIPAS-B2 instrument

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    International audienceOrganic compounds play a central role in troposphere chemistry and increasingly are a viable target for remote sensing observations. In this paper, infra-red spectral features of three organic compounds are investigated in thermal emission spectra recorded by a balloon-borne instrument, MIPAS-B2, operating at high spectral resolution. It is demonstrated, for the first time, that PAN and acetone can be detected in infra-red remote sensing spectra of the upper troposphere; detection results are presented at tangent altitudes of 10.4 km and 7.5 km (not acetone). In addition, the results provide the first observation of spectral features of formic acid in thermal emission, as opposed to solar occultation, and confirm that concentrations of this gas are likely to be measurable in the free troposphere, given accurate spectroscopic data. For PAN, two bands are observed centred at 794 cm?1 and 1163 cm?1. For acetone and formic acid, one band has been detected for each so far with band centres at 1218 cm?1 and 1105 cm?1 respectively. Mixing ratios inferred at 10.4 km tangent altitude are 180 pptv and 530 pptv for PAN and acetone respectively, and 200 pptv for formic acid with HITRAN 2000 spectroscopy. Accuracies are on the order of 30 to 50%. The detection technique applied here is verified by examining weak but known signatures of CFC-12 and HCFC-22 in the same spectral regions as those of the organic compounds, with results confirming the quality of both the instrument and the radiative transfer model. The results suggest the possibility of global sensing of the organic compounds studied here which would be a major step forward in verifying and interpreting global tropospheric model calculations

    Protein phosphatase 5 regulates titin phosphorylation and function at a sarcomere-associated mechanosensor complex in cardiomyocytes.

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    Serine/threonine protein phosphatase 5 (PP5) is ubiquitously expressed in eukaryotic cells; however, its function in cardiomyocytes is unknown. Under basal conditions, PP5 is autoinhibited, but enzymatic activity rises upon binding of specific factors, such as the chaperone Hsp90. Here we show that PP5 binds and dephosphorylates the elastic N2B-unique sequence (N2Bus) of titin in cardiomyocytes. Using various binding and phosphorylation tests, cell-culture manipulation, and transgenic mouse hearts, we demonstrate that PP5 associates with N2Bus in vitro and in sarcomeres and is antagonistic to several protein kinases, which phosphorylate N2Bus and lower titin-based passive tension. PP5 is pathologically elevated and likely contributes to hypo-phosphorylation of N2Bus in failing human hearts. Furthermore, Hsp90-activated PP5 interacts with components of a sarcomeric, N2Bus-associated, mechanosensor complex, and blocks mitogen-activated protein-kinase signaling in this complex. Our work establishes PP5 as a compartmentalized, well-controlled phosphatase in cardiomyocytes, which regulates titin properties and kinase signaling at the myofilaments

    Factors associated with drug-related harms related to policing in Tijuana, Mexico

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    <p>Abstract</p> <p>Objective</p> <p>To assess factors associated with drug-related harms related to policing among injection drug users (IDUs) in Tijuana, Mexico.</p> <p>Methods</p> <p>IDUs who were over 18 years old and had injected drugs within the last six months were recruited via respondent-driven sampling and underwent questionnaires and testing for HIV (human immunodeficiency virus), syphilis and TB (tuberculosis). Random effects logistic regression was used to simultaneously model factors associated with five drug-related harms related to policing practices in the prior six months (i.e., police led them to rush injections; affected where they bought drugs; affected locations where they used drugs; feared that police will interfere with their drug use; receptive syringe sharing).</p> <p>Results</p> <p>Of 727 IDUs, 85% were male; median age was 38 years. Within the last 6 months, 231 (32%) of IDUs reported that police had led them to rush injections, affected where they bought or used drugs or were very afraid police would interfere with their drug use, or shared syringes. Factors independently associated with drug-related harms related to policing within the last six months included: recent arrest, homelessness, higher frequencies of drug injection, use of methamphetamine, using the local needle exchange program and perceiving a decrease in the purity of at least one drug.</p> <p>Conclusions</p> <p>IDUs who experienced drug-related harms related to policing were those who were most affected by other micro and macro influences in the physical risk environment. Police education programs are needed to ensure that policing practices do not exacerbate risky behaviors or discourage protective behaviors such as needle exchange program use, which undermines the right to health for people who inject drugs.</p

    Exploiting the potential of bioactive molecules extracted by ultrasounds from avocado peelsfood and nutraceutical applications

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    Natural bioactive compounds from food waste have fomented interest in food and pharmaceutical industries for the past decade. In this work, it purposed the recovery of bioactive avocado peel extract using an environmentally friendly technique: the ultrasound assisted extraction. The response surface methodology was applied in order to optimize the conditions of the extraction, ethanol-water mixtures and time. The optimized extracts (ethanol 38.46%, 44.06 min, and 50 °C) were chemically characterized by HPLC-ESI-MS and FTIR. Its antioxidant ability, as well as, its effect on cell metabolic activity of normal (L929) and cancer (Caco-2, A549 and HeLa) cell lines were assessed. Aqueous ethanol extracts presented a high content in bioactive compounds with high antioxidant potential. The most representative class of the phenolic compounds found in the avocado peel extract were phenolic acids, such as hydroxybenzoic and hydroxycinnamic acids. Another important chemical group detected were the flavonoids, such as flavanols, flavanonols, flavones, flavanones and chalcone, phenylethanoids and lignans. In terms of its influence on the metabolic activity of normal and cancer cell lines, the extract does not significantly affect normal cells. On the other hand, it can negatively affect cancer cells, particularly HeLa cells. These results clearly demonstrated that ultrasound is a sustainable extraction technique, resulting in extracts with low toxicity in normal cells and with potential application in food, pharmaceutical or nutraceutical sectors.The authors acknowledge the financial support received from “Xunta de Galicia” (GRC ED431C 2017/62-GRC, and Project ED431F 2020/03). These projects are partially funded by the FEDER Program of the European Union (“Unha maneira de facer Europa”). This research was also funded by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit. Beatriz Gullón would like to express her gratitude to the Spanish Ministry of Economy and Competitiveness for her postdoctoral grant (Reference RYC2018-026177-I).info:eu-repo/semantics/publishedVersio

    Optimization of ultrasound-assisted extraction of phenolic compoundsfrom avocado peels

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    Avocado (Persea americana Mill.), a fruit native to Central America and Mexico, is one of the most consumed fruits in the world, with a global production of approximately 6.3 million tonnes in 2018. Its industrial processing generates significant amounts of by-products, mainly peels, seeds, or exhausted pulp, which disposal causes important environmental and economic problems. Nevertheless, these by-products present a high content of bioactive molecules with many human health benefits, which could be used for the formulation of functional foods or cosmetic products (Del Castillo-Llamosas et al., 2021; Rodríguez-Martínez et al., 2021). One of the important challenges for the recovery of added-value molecules from agro-industrial wastes is the selection of extraction technologies leading to high extraction efficiency and helping to preserve the quality of the recovered molecules. In this framework, ultrasound-assisted extraction (UAE) has been considered a green technology for the isolation of bioactive compounds from several natural sources. The purpose of the present study was to optimize the extraction of antioxidants from avocado peel (AP) using ultrasounds. The influence of ethanol/water ratio and time was evaluated using response Surface methodology (RSM). Under selected operational conditions (38.46% ethanol and 44.06 min), the response values were 45.34 mg GAE/g dried AP and 87.56 mg RE/g dried AP for TPC and TFC, respectively, with antioxidant levels of 73.25, 160.34 and 44.65 mg TE/g dried AP as determined by the DPPH, ABTS and FRAP methods, respectively. In addition, the optimized extracts were chemically characterized by HPLC-ESI-MS and FTIR. The main the phenolic compounds found in the avocado peel extract were phenolic acids, such as hydroxybenzoic and hydroxycinnamic acids.The authors acknowledge the financial support received from “Xunta de Galicia” (GRC ED431C 2017/62-GRC, and Project ED431F 2020/03). These projects are partially funded by the FEDER Program of the European Union (“Unha maneira de facer Europa”). Beatriz Gullón would like to express her gratitude to the Spanish Ministry of Economy and Competitiveness for her postdoctoral grant (Reference RYC2018-026177-I).info:eu-repo/semantics/publishedVersio

    A qualitative assessment of stakeholder perceptions and socio-cultural influences on the acceptability of harm reduction programs in Tijuana, Mexico

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    <p>Abstract</p> <p>Background</p> <p>The Mexico-U.S. border region is experiencing rising rates of blood-borne infections among injection drug users (IDUs), emphasizing the need for harm reduction interventions.</p> <p>Methods</p> <p>We assessed the religious and cultural factors affecting the acceptability and feasibility of three harm reduction interventions – Needle exchange programs (NEPs), syringe vending machines, and safer injection facilities (SIFs) – in Tijuana, Mexico. In-depth qualitative interviews were conducted with 40 community stakeholders to explore cultural and societal-related themes.</p> <p>Results</p> <p>Themes that emerged included Tijuana's location as a border city, family values, and culture as a mediator of social stigma and empathy towards IDUs. Perception of low levels of both awareness and socio-cultural readiness for harm reduction interventions was noted. Religious culture emerged as a theme, highlighting the important role religious leaders play in determining community responses to harm reduction and rehabilitation strategies for IDUs. The influence of religious culture on stakeholders' opinions concerning harm reduction interventions was evidenced by discussions of family and social values, stigma, and resulting policies.</p> <p>Conclusion</p> <p>Religion and politics were described as both a perceived benefit and deterrent, highlighting the need to further explore the overall influences of culture on the acceptability and implementation of harm reduction programs for drug users.</p
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