Publications by authors named "Nayara Dos Santos"

Forensic chemistry literature has grown exponentially, with many analytical techniques being used to provide valuable information to help solve criminal cases. Among them, matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS), particularly MALDI MS imaging (MALDI MSI), has shown much potential in forensic applications. Due to its high specificity, MALDI MSI can analyze a wide variety of compounds in complex samples without extensive sample preparation, providing chemical profiles and spatial distributions of given analyte(s).

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In the fullerene cone HIV-1 capsid, the central channels of the hexameric and pentameric capsomers each contain a ring of arginine (Arg18) residues that perform essential roles in capsid assembly and function. In both the hexamer and pentamer, the Arg18 rings coordinate inositol hexakisphosphate, an assembly and stability factor for the capsid. Previously, it was shown that amino-acid substitutions of Arg18 can promote pentamer incorporation into capsid-like particles (CLPs) that spontaneously assemble in vitro under high-salt conditions.

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Article Synopsis
  • A series of 19 novel eugenol derivatives featuring a 1,2,3-triazole structure were synthesized using a copper(I)-catalyzed reaction, aimed at enhancing antifungal activity.
  • Several triazole compounds were tested for their effectiveness against the fungus causing papaya anthracnose, with four compounds showing significant reductions in mycelial growth by over 80%.
  • Molecular docking studies revealed how these derivatives bind to the CYP51 enzyme, suggesting that their antifungal properties may stem from blocking substrate access, paving the way for environmentally friendly antifungal agents.
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The area of forensic chemistry has been growing and developing as a line of research due to the high demands of public safety that require increasingly reliable results due to their importance in criminalistics. In this way, the development of new technologies that help this area, whether in the identification and quantification of drugs or the fight against fraud, becomes promising. In this context, the present work explored the production of reference standards from the purification of cocaine/crack samples seized by the Civil Police of the State of Espírito Santo.

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The HIV-1 capsid is a fullerene cone made of quasi-equivalent hexamers and pentamers of the viral CA protein. Typically, quasi-equivalent assembly of viral capsid subunits is controlled by a molecular switch. Here, we identify a Thr-Val-Gly-Gly motif that modulates CA hexamer/pentamer switching by folding into a 3 helix in the pentamer and random coil in the hexamer.

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Background: In recent years, several studies have demonstrated that bacterial ABC transporters present relevant antigen targets for the development of vaccines against bacteria such as Streptococcus pneumoniae and Enterococcus faecalis. In Streptococcus mutans, the glutamate transporter operon (glnH), encoding an ABC transporter, is associated with acid tolerance and represents an important virulence-associated factor for the development of dental caries.

Results: In this study, we generated a recombinant form of the S.

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We estimated the losses caused by gastrointestinal nematode (GIN) infections in young Nellore cattle born in three consecutive calving seasons (Cycles I, II and III). Three groups of animals: Group 1 - free from GIN using 2.5 mg/kg of albendazole sulfoxide; Group II - free from Oesophagosomum radiatum using 0.

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Article Synopsis
  • MALDI IMS is a technique used to identify and map the distribution of molecules in samples while keeping their natural structure intact, but its application on the spatial distribution of alkaloids in coca leaves is not well-studied.
  • This research utilized MALDI(+)FT-ICR IMS to identify and analyze alkaloids on coca leaf surfaces, testing different matrices and finding that 2,5-dihydroxybenzoic acid (DHB) was the most effective at a concentration of 2 mg·mL.
  • The study also examined the inner leaf tissue, revealing the presence of alkaloids and flavonoids, while washing the leaves with various organic solvents did not enhance ionization efficiency.
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The concentrations of lead (Pb), barium (Ba), and antimony (Sb), characteristic of GSR, were determined in soil sediments and immature (larvae) of cadaveric flies of the family Calliphoridae, by inductively coupled plasma mass spectrometry (ICP-MS). This research refers to a case study from two real crime scenes in which the corpses were in an advanced state of decomposition. In case 1, the victim had holes similar to gunshot wounds, and in case 2, there was no evidence of perforations in the corpse.

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The consumption of design drugs, frequently known as new psychoactive substances (NPS), has increased considerably worldwide, becoming a severe issue for the responsible governmental agencies. These illicit substances can be defined as synthetic compounds produced in clandestine laboratories in order to act as analogs of schedule drugs mimetizing its chemical structure and improving its pharmacological effects while hampering the control and making regulation more complicated. In this way, the development of new methodologies for chemical analysis of NPS drugs is indispensable to determine a novel class of drugs arising from the underground market.

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Streptococcus agalactiae or group B Streptococcus (GBS) is a Gram-positive bacterium divided into ten distinct serotypes that colonizes the vaginal and rectal tracts of approximately 30% of women worldwide. GBS is the leading cause of invasive infection in newborns, causing sepsis, pneumoniae and meningitis. The main strategy to prevent GSB infection in newborns includes the use of intrapartum antibiotic therapy, which does not prevent late-onset diseases and may select resistant bacterial strains.

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Rationale: Ambient mass spectrometry techniques are much required in forensic chemistry to evaluate evidence with low analytical interference, high confidence, and accuracy. However, traditional methodologies, such as paper spray ionization, have been shown to present low sensitivity in the analysis of illicit drugs from biological matrices.

Methods: Fiber spray ionization mass spectrometry (FSI-MS) was developed using a capillary polypropylene (PP) hollow fiber.

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Brazilian data for maternal GBS colonization shows different prevalence rates. This conflicting data may be related to the absence of an official recommendation from the Federal Brazilian Health Authorities describing guidelines and protocols to perform GBS screening in pregnant women, in both public and private clinics. In the present review, we evaluated published reports addressing the prevalence of GBS in different regions of the country, methods used, and, when available, information regarding antibiotic resistance and serological typing of clinical isolates.

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Background And Purpose: The incidence of stroke is on the rise in young adults in high-income countries. However, there is a gap of knowledge about trends in stroke incidence in young adults from low- and middle-income countries. We aimed to measure trends in incidence of ischemic stroke (IS) and intracerebral hemorrhage (IH) in young people from 2005 to 2015 in Joinville, Brazil.

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