The ionization mechanism in dopant-assisted atmospheric pressure photoionization and the effect of solvent on the ionization efficiency was studied using 7 naphthalenes and 13 different solvent ...systems. The ionization efficiency was 1−2 orders of magnitude higher with dopant than without, indicating that the photoionization of the dopant initiates the ionization process. In positive ion mode, the analytes were ionized either by charge exchange or by proton transfer. Charge exchange was favored for low proton affinity solvents (water, hexane, chloroform), whereas the addition of methanol or acetonitrile to the solvent initiated proton transfer. In negative ion mode, the compounds with high electron affinity were ionized by electron capture or by charge exchange and the compounds with high gas-phase acidity were ionized by proton transfer. In addition, some oxidation reactions were observed. All the reactions leading to ionization of analytes in negative ion mode are initiated by thermal electrons formed in photoionization of toluene. The testing of different solvents showed that addition of buffers such as ammonium acetate, ammonium hydroxide, or acetic acid may suppress ionization in APPI. The reactions are discussed in detail in light of thermodynamic data.
The quality of the micromechanical retention between the enamel prisms exposed through acid etching and adhesive system can be influenced by the relationship between the angle of the exposed enamel ...prisms and the external surface/restorative material. Therefore, the aim of the present study was to determine the influence of the enamel cavosurface beveling in different cavity sizes on the angle relation between enamel prisms and the restorative material. For this research, 30 human permanent molars were used and divided into three groups according the isthmus aperture of class I cavities (1/4, 1/3, and 1/2 of the intercuspal distance). Cavosurface angle beveling was performed in each tooth buccal or palatal/lingual side, and a resin composite restoration was placed. Each restored tooth was sectioned in buccal/palatal direction followed by analysis in scanning electron microscope. Means of the angles observed between enamel prisms and the restorative material were registered and statistically analyzed by Kruskal‐Wallis test. Results showed higher mean angle values for beveled groups when comparing with the values observed in the unbeveled margins (p < .05) regardless of the isthmus aperture, being 1/4 (beveled = 48.36°; unbeveled = 20.71°), 1/3 (beveled = 39.75°; unbeveled = 29.15°), and 1/2 (beveled = 37.02°; unbeveled = 26.34°). It was also observed that in some unbeveled cavities, there were the presence of laterally exposed enamel prisms (0°), mainly in more conservative cavities. It was concluded that the presence of higher angles values occurred in the samples with beveled margins, without presence of laterally exposed enamel prisms.
Different cavity preparations result in different relationship between enamel prisms orientation and the restorative surfaces. Since a parallel disposition can result in a jeopardized adhesive interface, which may lead to a short‐term restoration failure, the beveling of the cavosurface angle improved prisms angle of exposure and could be a contributing factor for longer lasting restorations.
Extracts from grape pomace, including the wine, show many biological effects such as antioxidant and anti-inflammatory activities. Unfortunately, winemakers discard the bagasse, so the waste is not ...exploited, although it contains bioactive compounds with antioxidant and anti-inflammatory properties. The work aims to analyze the hydroethanolic extract of peels from
agro-industrial waste and to evaluate its antinociceptive and anti-inflammatory properties. This study is relevant for reusing a residue and adding value to the grape economic chain.
A representative sample of pomace was obtained and the peels were used to produce the extract. The phenolic compounds were determined by mass spectrometry in multiple reaction monitoring mode and Folin-Ciocalteu colorimetric method, using gallic acid as standard. The biological analyses were carried out using mice orally treated with crude extract at doses of 30, 100 and 300 mg/kg. We evaluated mechanical hyperalgesia by the von Frey method, thermal heat hyperalgesia using a hot plate at 55 °C, paw edema using a pachymeter, and neutrophil recruitment by measurement of myeloperoxidase activity. The nephrotoxicity and hepatotoxicity were evaluated by biochemical analyses using blood samples that were collected after the
administration.
In all wet winemaking residues peel mass fraction was 75%, and in dry residues 59%. We identified nine anthocyanins (3-
-glucosides: peonidin, delphinidin, petunidin and malvidin; 3-
-coumaroyl-glucosides: cyanidin, peonidin, petunidin and malvidin, and malvidin-3,5-diglucoside), five flavonoids (apigenin-7-glucoside, luteolin-7-glucoside, quercetin-3-galactoside, isorhamnetin-3-glucoside and myricetin-3-rutinoside), and mass fraction of phenolic compounds, expressed as gallic acid equivalents, was 26.62 mg/g.
assays showed that
extract at mass fractions 100 and 300 mg/kg reduced carrageenan-induced mechanical and thermal hyperalgesia, 50% of the paw edema, and neutrophil recruitment. In addition, there were no indications of nephrotoxicity and hepatotoxicity. Our extract obtained from winemaking residue has analgesic and anti-inflammatory properties, related at least in part to the presence of phenolic compounds, and it is not toxic to renal and hepatic tissues.
This bio-product can be used as an alternative to synthetic anti-inflammatory agents with the same pharmacological potential and fewer side effects. We demonstrated that
winemaking waste can be used for the production of antinociceptive and anti-inflammatory products (nutraceutical, pharmaceutical and cosmetics) without toxicity, contributing to the environmental economy.
This study aims to analyze the spatial distributions of several metals in sediments from five sites in Ribeira Bay, Brazil. Ribeira Bay is a very important area to the local community, due to its ...artisan fishery, and it also has a biological relevance for many marine species that use mangroves as nursery and feeding sites. According to the results, the area was not considered a metal polluted area. Despite not having a significant source of metals inside the Bay nowadays, Ilha Grande Bay harbors a shipyard, an oil terminal, and a commercial port, as well as two thermonuclear power plants (Angra I e II), all of which indirectly influence the study area.
A simple, sensitive and specific liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for the quantification of memantine (
I) in human plasma is presented. Sample preparation consisted ...of the addition of amantadine (
II) as internal standard (IS), liquid–liquid extraction in basic conditions using a mixture of diethyl ether–chloroform (7:3, v/v) as extracting solvent, followed by centrifugation, solvent evaporation and sample reconstitution in methanol. Both
I and
II (internal standard) were analyzed using a C18 column and a mobile phase composed of methanol–water–formic acid (80:20:0.1, v/v/v). Eluted compounds were monitored using positive mode electrospray (ES) tandem mass spectrometry. The analyses were carried out by selected reaction monitoring (SRM) using the parent to daughter combinations of
m/
z 180
>
163 (memantine) and
m/
z 152
>
135 (amantadine). The peak areas from the analyte and IS were used for quantification of
I. The achieved limit of quantification (LOQ) was 0.1
ng/mL; the assay exhibited a linear dynamic range of 0.1–50.0
ng/mL with a determination coefficient (
r
2) of at least 0.98. Validation results on linearity, specificity, accuracy, precision and stability, as well as on application to the analysis of samples taken up to 320
h after oral administration of 20
mg (two 10
mg capsules) of
I in healthy volunteers demonstrated the applicability to bioequivalence studies.
We describe a liquid chromatography–tandem mass spectrometric method (LC–MS/MS) for levocetirizine quantification (I) in human plasma. Sample preparation was made using a fexofenadine (II) addition ...as internal standard (IS), liquid–liquid extraction using cold dichloromethane, and dissolving the final extract in acetonitrile. I and II (IS) were injected in a C18 column and the mobile phase composed of acetonitrile:water:formic acid (80.00:19.90:0.10, v/v/v) and monitored using positive electrospray source with tandem mass spectrometry analyses. The selected reaction monitoring (SRM) was set using precursor ion and product ion combinations of
m/z 389
>
201 for I and
m/z 502
>
467 for II. The limit of quantification and the dynamic range achieved were 0.5
ng/mL and 0.5–500.0
ng/mL. Validation results on linearity, specificity, accuracy, precision and stability, as well as its application to the analysis of plasma samples taken up to 48
h after oral administration of 5
mg of levocetirizine dichloridrate in healthy volunteers demonstrate its applicability to bioavailability studies.
Immune Response Resetting in Ongoing Sepsis Nowill, Alexandre E; Fornazin, Márcia C; Spago, Maria C ...
The Journal of immunology (1950),
09/2019, Volume:
203, Issue:
5
Journal Article
Peer reviewed
Open access
Cure of severe infections, sepsis, and septic shock with antimicrobial drugs is a challenge because morbidity and mortality in these conditions are essentially caused by improper immune response. We ...have tested the hypothesis that repeated reactivation of established memory to pathogens may reset unfavorable immune responses. We have chosen for this purpose a highly stringent mouse model of polymicrobial sepsis by cecum ligation and puncture. Five weeks after priming with a diverse Ag pool, high-grade sepsis was induced in C57BL/6j mice that was lethal in 24 h if left untreated. Antimicrobial drug (imipenem) alone rescued 9.7% of the animals from death, but >5-fold higher cure rate could be achieved by combining imipenem and two rechallenges with the Ag pool (
< 0.0001). Antigenic stimulation fine-tuned the immune response in sepsis by contracting the total CD3
T cell compartment in the spleen and disengaging the hyperactivation state in the memory T subsets, most notably CD8
T cells, while preserving the recovery of naive subsets. Quantitative proteomics/lipidomics analyses revealed that the combined treatment reverted the molecular signature of sepsis for cytokine storm, and deregulated inflammatory reaction and proapoptotic environment, as well as the lysophosphatidylcholine/phosphatidylcholine ratio. Our results showed the feasibility of resetting uncontrolled hyperinflammatory reactions into ordered hypoinflammatory responses by memory reactivation, thereby reducing morbidity and mortality in antibiotic-treated sepsis. This beneficial effect was not dependent on the generation of a pathogen-driven immune response itself but rather on the reactivation of memory to a diverse Ag pool that modulates the ongoing response.
The High Elevation Auger Telescopes (HEAT) are three tiltable fluorescence telescopes which represent a low energy enhancement of the fluorescence telescope system of the southern site of the Pierre ...Auger Observatory in Argentina. The Pierre Auger Observatory is a hybrid cosmic ray detector consisting of 24 fluorescence telescopes to measure the fluorescence light of extensive air showers complemented by 1600 water Cherenkov detectors to determine the particle densities at ground. In this configuration air showers with a primary energy of 10 18 eV and above are investigated. By lowering the energy threshold by approximately one order of magnitude down to a primary energy of 1017 eV, HEAT provides the possibility to study the cosmic ray energy spectrum and mass composition in a very interesting energy range, where the transition from galactic to extragalactic cosmic rays is expected to happen. The installation of HEAT was finished in 2009 and data have been taken continuously since September 2009. Within these proceedings the HEAT concept is presented. First data already demonstrate the excellent complement of the standard Auger fluorescence telescopes by HEAT.
Cotyledonary node transformation efficiency was evaluated using a sonication assisted Agrobacterium-mediated transformation (SAAT) protocol, three dissimilar A. tumefaciens strains, and explants ...derived from 28 diverse cultivars and/or genotypes of soybean Glycine max (L.) Merr.. The explants were evaluated at 10 and 45 days after co-cultivation for transformation with a binary vector containing both a GUS-intron gene and an NPTII selectable marker. The best overall strain of A. tumefaciens was determined to be KYRT1 based on stable GUS transformation of soybean cotyledonary node explants measured at the terminal 45 day evaluation point. SAAT did not increase stable transformation at 45 days post co-cultivation. SAAT was determined to significantly decrease shoot proliferation of some genotypes, but it is unclear what effect this may have on the recovery of transformed shoots. Significant differences were also detected between genotypes for transformation and shoot proliferation frequency.
We describe a fast (5 min) liquid chromatography tandem mass spectrometry method (LC–MS/MS) based on a 46 Da neutral loss of formic acid (H2O and CO) to identify tri‐ and dipeptides (DIPEP) in whey ...protein and porcine liver protein hydrolysates and confirmed by further de novo sequencing. Sample solutions were acidified to favor dipep + H+ ions, and a m/z range of 50–300 was used to improve sensitivity. All dipeptide candidates were selected based on all possibilities of the 20 amino acid combinations, and their collision‐induced dissociation fragments were screened via de novo sequencing. To determine their biological activities, sequenced dipeptides were compared with the Biopep database and other data from literature. Altogether, 18 dipeptides and 7 tripeptides were identified from the whey protein hydrolysate; they seemed to be broadly active, and peptides were identified as active dipeptidyl peptidase IV inhibitors and active angiotensin‐converting enzyme (ACE), according to available information. Porcine liver hydrolysate showed 14 dipeptides which exhibit similar biological activities to whey protein hydrolysate.
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