177 research outputs found

    Graphene Based Sensors for Air Quality Monitoring - Preliminary Development Evaluation

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    Indoor air pollution can induce adverse health effects on building occupants and pose a significant role in health worldwide. To avoid such effects, it is extremely important to monitor and control common indoor pollutants such as CO2, VOCs and relative humidity. Therefore, this work focuses on recent advances in the field of graphene-based gas sensors, emphasizing the use of modified graphene that broadly expands the range of nanomaterials sensors. Graphene films were grown on copper by chemical vapor deposition (CVD) and transferred to arbitrary substrates. After synthesis, the samples were functionalized with Al2O3 by ALD and characterized by a large set of experimental techniques such as XPS, Raman and SEM. The results demonstrated that graphene was successfully synthesized and transferred to SiO2, glass and polymer. As a proof-of-concept, ALD of Al2O3 was performed on the graphene surface to produce a graphene/metal oxide nanostructure towards the development of nanocomposites for gas sensing. From this perspective, a laboratory prototype device based in measuring the electrical properties of the graphene sample as a function of the gas absorption is under development

    A Cost-Effective Way To Expressively Increase the Blood-Stage Antimalarial Activity of Primaquine

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    Funding Information: The authors thank Fundação para a CiĂȘncia e Tecnologia (FCT, Portugal), for funding Research Units LAQV‐REQUIMTE (UIDB/50006/2020), CIQUP (UIDB/00081/2020), and GHTM (UID/Multi/04413/2013), and for project grant PTDC/BTM‐SAL/29786/2017. ATS thanks FCT and Sociedade Portuguesa de QuĂ­mica (SPQ, Portugal) for her doctoral grant SFRH/BD/150649/2020 Publisher Copyright: © 2021 Wiley-VCH GmbHInspired by previous disclosure of room-temperature ionic liquids derived from primaquine and cinnamic acids, which displayed slightly enhanced blood-stage activity compared to the parent drug, we have now combined this emblematic antimalarial with natural fatty acids. This affords surface-active ionic liquids whose liver-stage antiplasmodial activity is either retained or slightly enhanced, while revealing blood-stage antiplasmodial activity at least one order of magnitude higher than that of the parent compound. These findings open new perspectives towards the cost-effective recycling of classical drugs that are either shelved or in decline, and which is not limited to antimalarial agents.publishersversionpublishe

    Drug-Derived Surface-Active Ionic Liquids: A Cost-Effective Way To Expressively Increase the Blood-Stage Antimalarial Activity of Primaquine (ChemMedChem, (2022), 17, 5, 10.1002/cmdc.202100650)

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    Scheme 1 and Figure 1 in this article were incorrect. The correct ones, and their respective captions, follow: 1 Scheme (Figure presented.) Synthesis route to PQ-derived organic salts 3a–g. (i) 1a (1 molar equivalent, eq), 2a–g (1 eq), methanol (MeOH), room temperature (RT), 30 min. 1 Figure (Figure presented.) Surface tension plots and cmc determination, at 25 °C, of aqueous CTAB/SAIL mixtures: A) surface tension vs. the logarithm of total CTAB+SAIL concentration, expressed in molality; the cmc values are obtained from the intersection points of the linear fit in each system; B) cmc vs. molar fraction of 3c in mixtures with CTAB, showing the marked effect of 3c in reducing cmc.publishersversionpublishe

    Surtos de enfermidades transmitidas por alimentos causados por Salmonella Enteritidis

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    OBJETIVO: SĂŁo descritos surtos de salmonelose notificados no perĂ­odo de julho de 1993 a junho de 1997 na regiĂŁo Noroeste do Estado de SĂŁo Paulo, Brasil, tendo em vista os vĂĄrios surtos de veiculação alimentar ocasionados por Salmonella nessa regiĂŁo. MÉTODO: Foram obtidos 19 inquĂ©ritos epidemiolĂłgicos para anĂĄlise de dados, 87 amostras de fezes e 38 amostras de alimentos, incluindo 12 de ovos para anĂĄlise microbiolĂłgica. Cepas de Salmonella foram submetidas a sorotipagem, fagotipagem e teste de sensibilidade a 13 agentes antimicrobianos. RESULTADOS: Foram acometidas 906 pessoas com 295 hospitalizaçÔes. Cepas de Salmonella Enteritidis Fagotipo 4 foram isoladas de 80,5% das coproculturas, de todas amostras de alimentose de 41,7% dos ovos. Em 22 (95,7%) surtos os a salmonela foi veiculada por alimentos contendo ovos crus ou semicrus. Os testes de sensibilidade a antimicrobianos revelaram sensibilidade Ă  maioria das cepas. CONCLUSÕES: Considerando os resultados obtidos, torna-se necessĂĄria a implantação e intensificação de medidas de controle na produção e armazenamento dos ovos, alĂ©m da orientação Ă  população quanto aos riscos no consumo inadequado desse alimento.OBJECTIVE: It is to describe outbreaks of salmonellosis reported from July 1993 through June 1997 in the Northwest region of S. Paulo State, Brazil, one of the areas where several foodborne outbreaks of salmonellosis have been recently detected. METHOD: Data of 19 epidemiological investigations were analysed; 87 stool specimens and 38 food samples (including 12 of shell eggs) were processed for microbiological analysis. Salmonella strains were identified by serotyping, phagetyping and antimicrobial susceptibility testing. RESULTS: There were 906 ill persons including 295 hospitalized patients. Phage type 4 (PT 4) Salmonella Enteritidis strains were isolated from 80.5% of stool samples, from all food samples and from 41.7% of eggs. Of the outbreaks, 95.7% were associated with the consumption of food containing raw or undercooked eggs. All strains were susceptible to the 13 antimicrobials, except the strains from the nosocomial outbreak. CONCLUSIONS: The results obtained show the need for the implementation of control measures regarding egg procdution and storage, as well as for guidance to the public as to the risks involved in the consumption of inadequately prepared eggs

    Pengaruh lama penyimpanan bubuk beluntas (Pluchea indica Less.) dalam tea bag terhadap perubahan sifat fisikokimia air seduhan

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    Daun beluntas merupakan tanaman perdu yang sering digunakan sebagai obat tradisional. Pemanfaatan daun beluntas sebagai minuman seduhan teh beluntas menjadi salah satu inovasi. Pengolahan beluntas yang dikemas dalam tea bag akan lebih efisien dan juga lebih praktis. Produk bubuk sangat sensitif dan mudah mengalami perubahan selama penyimpanan. Berdasarkan hal tersebut maka lama penyimpanan bubuk beluntas dalam tea bag diduga berpengaruh pada sifat fisikokimia seperti kekeruhan, total asam dan pH dari minuman seduhan teh beluntas. Tujuan penelitian yang dilakukan adalah untuk mengetahui pengaruh lama penyimpanan bubuk daun beluntas dalam tea bag terhadap perubahan sifat fisikokimia meliputi kekeruhan, pH, dan total asam pada air seduhan teh beluntas. Rancangan penelitian yang digunakan yaitu rancangan acak kelompok (RAK) dengan satu faktor yaitu lama penyimpanan bubuk beluntas dalam tea bag yang terdiri dari 9 taraf perlakuan yaitu P1 (0 minggu), P2 (2 minggu), P3 (4 minggu), P4 (6 minggu), P5 (10 minggu), P6 (14 minggu), P7 (18 minggu), P8 (22 minggu) dan P9 (26 minggu) dengan ulangan sebanyak tiga kali. Parameter utama yang diuji yaitu sifat fisikokimia meliputi kadar air, pH, kekeruhan dan total asam. Data yang diperoleh dilakukan analisa varian (ANOVA) pada α=5% dan dilanjutkan analisa regresi linear untuk menentukan model trendline dan melihat kecenderungan kurva. Hasil penelitian menunjukkan bahwa lama penyimpanan bubuk daun beluntas berpengaruh terhadap sifat fisikokimia air seduhan. Kadar air, kekeruhan, derajat keasaman (pH) dan total asam masing-masing sebesar 8,88%-8,37% (db), 5,68-15,90 NTU; 6,85-8,10 dan 0,43-0,95 mg asam klorogenat/100g bahan. Kinetika degradasi kadar air mengikuti orde 0 dengan perkiraan umur simpan 148 hari

    In silico ADMET prediction, evaluation of cytotoxicity in mouse splenocytes and preliminary evaluation of in vitro antimalarial activity of 4-(4-chlorophenyl)thiazole compounds

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    Abstract In this work, an in silico study and evaluation of the cytotoxicity of 4-(4-chlorophenyl)thiazole compounds against mouse splenocytes and the chloroquine-sensitive Plasmodium falciparum 3D7 strain are reported. The in silico results showed that the compounds have important pharmacokinetic properties for compounds with potential drug candidates. Regarding cytotoxicity assays against splenocytes, the compounds have low cytotoxicity. In addition, they were able to promote activation of these cells by increasing nitric oxide production without promoting cell death. Finally, they were able to promote cell proliferation. Regarding the in vitro anti-P. falciparum activity assays, it was observed that the compounds were able to inhibit the parasite’s growth, presenting IC50 values ranging from 0.79 to greater than 10 ”M. These results are promising when compared to chloroquine. Therefore, this study showed that 4-(4-chlorophenyl)thiazole compounds are promising candidates for antimalarials

    The ELIXIR Human Copy Number Variations Community:building bioinformatics infrastructure for research

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    Copy number variations (CNVs) are major causative contributors both in the genesis of genetic diseases and human neoplasias. While 'High-Throughput' sequencing technologies are increasingly becoming the primary choice for genomic screening analysis, their ability to efficiently detect CNVs is still heterogeneous and remains to be developed. The aim of this white paper is to provide a guiding framework for the future contributions of ELIXIR's recently established h uman CNV Community, with implications beyond human disease diagnostics and population genomics. This white paper is the direct result of a strategy meeting that took place in September 2018 in Hinxton (UK) and involved representatives of 11 ELIXIR Nodes. The meeting led to the definition of priority objectives and tasks, to address a wide range of CNV-related challenges ranging from detection and interpretation to sharing and training. Here, we provide suggestions on how to align these tasks within the ELIXIR Platforms strategy, and on how to frame the activities of this new ELIXIR Community in the international context

    Active Nuclear Receptors Exhibit Highly Correlated AF-2 Domain Motions

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    Nuclear receptor ligand binding domains (LBDs) convert ligand binding events into changes in gene expression by recruiting transcriptional coregulators to a conserved activation function-2 (AF-2) surface. While most nuclear receptor LBDs form homo- or heterodimers, the human nuclear receptor pregnane X receptor (PXR) forms a unique and essential homodimer and is proposed to assemble into a functional heterotetramer with the retinoid X receptor (RXR). How the homodimer interface, which is located 30 Å from the AF-2, would affect function at this critical surface has remained unclear. By using 20- to 30-ns molecular dynamics simulations on PXR in various oligomerization states, we observed a remarkably high degree of correlated motion in the PXR–RXR heterotetramer, most notably in the four helices that create the AF-2 domain. The function of such correlation may be to create “active-capable” receptor complexes that are ready to bind to transcriptional coactivators. Indeed, we found in additional simulations that active-capable receptor complexes involving other orphan or steroid nuclear receptors also exhibit highly correlated AF-2 domain motions. We further propose a mechanism for the transmission of long-range motions through the nuclear receptor LBD to the AF-2 surface. Taken together, our findings indicate that long-range motions within the LBD scaffold are critical to nuclear receptor function by promoting a mobile AF-2 state ready to bind coactivators

    A Mycobacterium leprae Hsp65 Mutant as a Candidate for Mitigating Lupus Aggravation in Mice

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    Hsp60 is an abundant and highly conserved family of intracellular molecules. Increased levels of this family of proteins have been observed in the extracellular compartment in chronic inflammation. Administration of M. leprae Hsp65 [WT] in [NZBxNZW]F1 mice accelerates the Systemic Lupus Erythematosus [SLE] progression whereas the point mutated K409A Hsp65 protein delays the disease. Here, the biological effects of M. leprae Hsp65 Leader pep and K409A pep synthetic peptides, which cover residues 352–371, are presented. Peptides had immunomodulatory effects similar to that observed with their respective proteins on survival and the combined administration of K409A+Leader pep or K409A pep+WT showed that the mutant forms were able to inhibit the deleterious effect of WT on mortality, indicating the neutralizing potential of the mutant molecules in SLE progression. Molecular modeling showed that replacing Lysine by Alanine affects the electrostatic potential of the 352–371 region. The number of interactions observed for WT is much higher than for Hsp65 K409A and mouse Hsp60. The immunomodulatory effects of the point-mutated protein and peptide occurred regardless of the catalytic activity. These findings may be related to the lack of effect on survival when F1 mice were inoculated with Hsp60 or K409A pep. Our findings indicate the use of point-mutated Hsp65 molecules, such as the K409A protein and its corresponding peptide, that may minimize or delay the onset of SLE, representing a new approach to the treatment of autoimmune diseases
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