2,781 research outputs found

    Sensing Hydrocarbons With Interband Cascade Lasers And Substrate-integrated Hollow Waveguides

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    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Tunable diode laser absorption spectroscopy (TDLAS) is an excellent analytical technique for gas sensing applications. In situ sensing of relevant hydrocarbon gases is of substantial interest for a variety of in-field scenarios including environmental monitoring and process analysis, ideally providing accurate, molecule specific, and rapid information with minimal sampling requirements. Substrate-integrated hollow waveguides (iHWGs) have demonstrated superior properties for gas sensing applications owing to minimal sample volumes required while simultaneously serving as efficient photon conduits. Interband cascade lasers (ICLs) are recently emerging as mid-infrared light sources operating at room temperature, with low power consumption, and providing excellent potential for integration. Thereby, portable and handheld mid-infrared sensing devices are facilitated. Methane (CH4) is among the most frequently occurring, and thus, highly relevant hydrocarbons requiring in situ emission monitoring by taking advantage of its distinct molecular absorption around 3 mu m. Here, an efficient combination of iHWGs with ICLs is presented providing a methane sensor calibrated in the range of 100 to 2000 ppm(v) with a limit of detection at 38 ppmv at the current stage of development. Furthermore, a measurement precision of 0.62 ppb(v) during only 1 s of averaging time has been demonstrated, thereby rendering this sensor concept useful for in-line and on-site emission monitoring and process control applications.14144324437project APOSEMA - German BMBF/VDI within the M-Era.net programCNPq [407170/2013-8]CNPq (OSTEMPA-Optical Sensor Technologies for Environmental, Medical, and Process Analytics)INCTAA (CNPq) [573894/2008-6]INCTAA (FAPESP) [2008/57808-1]U.S. Department of Energy by Lawrence Livermore National Laboratory (LLNL) [DE-AC52-07NA27344]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Leishmania amazonensis Arginase Compartmentalization in the Glycosome Is Important for Parasite Infectivity

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    In Leishmania, de novo polyamine synthesis is initiated by the cleavage of L-arginine to urea and L-ornithine by the action of arginase (ARG, E.C. 3.5.3.1). Previous studies in L. major and L. mexicana showed that ARG is essential for in vitro growth in the absence of polyamines and needed for full infectivity in animal infections. The ARG protein is normally found within the parasite glycosome, and here we examined whether this localization is required for survival and infectivity. First, the localization of L. amazonensis ARG in the glycosome was confirmed in both the promastigote and amastigote stages. As in other species, arg− L. amazonensis required putrescine for growth and presented an attenuated infectivity. Restoration of a wild type ARG to the arg− mutant restored ARG expression, growth and infectivity. In contrast, restoration of a cytosol-targeted ARG lacking the glycosomal SKL targeting sequence (argΔSKL) restored growth but failed to restore infectivity. Further study showed that the ARGΔSKL protein was found in the cytosol as expected, but at very low levels. Our results indicate that the proper compartmentalization of L. amazonensis arginase in the glycosome is important for enzyme activity and optimal infectivity. Our conjecture is that parasite arginase participates in a complex equilibrium that defines the fate of L-arginine and that its proper subcellular location may be essential for this physiological orchestration

    Allergic reaction related to ramipril use: a case report

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    <p>Abstract</p> <p>Background</p> <p>Angiotensin-converting enzyme (ACE) inhibitors are widely prescribed for patients with diabetes as a nephroprotector drug or to treat hypertension. Generally they are safe for clinical practice, but the relationship between these drugs and angioedema is known. The exact mechanism for ACE inhibitors-induced angioedema is not clear and it is still a matter of discussion.</p> <p>Case Report</p> <p>We reported a case of a 23-year-old black female with an 11 year history of type 1 diabetes, regularly monitored in the department of diabetes, in use of 0,98 UI/kg/day of human insulin, which presented an allergic reaction 24 h after ramipril use. The drug had been prescribed to treat diabetic nephropathy. There was no previous history of drug induced or alimentary allergy. The patient was instructed to discontinue the use of ramipril and oral antihistaminic drug and topical corticosteroid were prescribed. Skin biopsies were performed and confirmed the clinical hypothesis of pharmacodermy. The evaluation of ACE polymorphism identified <it>DD </it>genotype. Six months after the withdrawal of ramipril the patient was prescribed the angiotensin-II receptor blocker (ARB) losartan as nephroprotector. She remained well without adverse reactions.</p> <p>Conclusions</p> <p>ACE inhibitors-induced angioedema is uncommon and the clinical presentation is variable with lips, tongue, oropharinge, and larynge as the most common locations. The presence of angioedema during treatment requires the immediate cessation of treatment due to the risk of possible severe complications. The case reported presented moderate symptoms, with the development of early onset edema in uncommon regions. ACE <it>DD </it>genotype had been associated with angioedema-ACE inhibitors induced. In patients who have experienced ACE inhibitor-related angioedema, ARB should be used cautiously used. However in the case of our patient, the prescription of losartan as nefroprotector did not result in any recurrent adverse effect.</p

    Rapid viral metagenomics using SMART-9N amplification and nanopore sequencing [version 2; peer review: 2 approved]

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    Emerging and re-emerging viruses are a global health concern. Genome sequencing as an approach for monitoring circulating viruses is currently hampered by complex and expensive methods. Untargeted, metagenomic nanopore sequencing can provide genomic information to identify pathogens, prepare for or even prevent outbreaks. SMART (Switching Mechanism at the 5' end of RNA Template) is a popular approach for RNA-Seq but most current methods rely on oligo-dT priming to target polyadenylated mRNA molecules. We have developed two random primed SMART-Seq approaches, a sequencing agnostic approach 'SMART-9N' and a version compatible rapid adapters  available from Oxford Nanopore Technologies 'Rapid SMART-9N'. The methods were developed using viral isolates, clinical samples, and compared to a gold-standard amplicon-based method. From a Zika virus isolate the SMART-9N approach recovered 10kb of the 10.8kb RNA genome in a single nanopore read. We also obtained full genome coverage at a high depth coverage using the Rapid SMART-9N, which takes only 10 minutes and costs up to 45% less than other methods. We found the limits of detection of these methods to be 6 focus forming units (FFU)/mL with 99.02% and 87.58% genome coverage for SMART-9N and Rapid SMART-9N respectively. Yellow fever virus plasma samples and SARS-CoV-2 nasopharyngeal samples previously confirmed by RT-qPCR with a broad range of Ct-values were selected for validation. Both methods produced greater genome coverage when compared to the multiplex PCR approach and we obtained the longest single read of this study (18.5 kb) with a SARS-CoV-2 clinical sample, 60% of the virus genome using the Rapid SMART-9N method. This work demonstrates that SMART-9N and Rapid SMART-9N are sensitive, low input, and long-read compatible alternatives for RNA virus detection and genome sequencing and Rapid SMART-9N improves the cost, time, and complexity of laboratory work
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