RESUMO

L-histidinium hydrogen oxalate (L-HisH)(HC2O4) crystal is formed from amino acid. L-histidine with oxalic acid whose vibrational high pressures behavior have not yet been investigated in the literature. Here we synthesized (L-HisH)(HC2O4) crystal by slow solvent evaporation method in a 1:1 ratio of L-histidine and oxalic acid. In addition, a vibrational study of (L-HisH)(HC2O4) crystal as a function of pressure was performed via Raman spectroscopy in the pressure range of 0.0-7.3 GPa. From analysis of the behavior of the bands within 1.5-2.8 GPa, characterized by the disappearance of lattice modes, the occurrence of a conformational phase transition was noted. A second phase transition, now from structural type, close to 5.1 GPa was observed due to the incidence of considerable changes in lattice and internal modes, mainly in vibrational modes related to imidazole ring motions.

RESUMO

Aiming of self-sustainable production, the search for biodegradable and biocompatible materials has brought with it the need to know the physicochemical and dielectric characteristics of polysaccharide-based composite structures, which can be used as important and promising raw materials for biotechnology and electronic industries. Galactomannans are polysaccharides, extracted from seeds and microbiological sources, consisting of mannose and galactose. In this context, this work aimed to extract, purify and characterize by XRD, FTIR and impedance spectroscopy galactomannan obtained from seeds of Adenanthera pavonina L. The purification process was made with ethyl alcohol at concentrations of 70, 80 and 90 %. Polymeric films were prepared by solvent slow evaporation at low temperatures. XRD measurements revealed that Galactomannan from Adenanthera pavonina L., after purification, has a semi-crystalline structure due to the identification of two peaks the first between 5.849° and 6.118° and the second between 20.011° and 20.247°. FTIR spectra showed the functional groups associated with monosaccharides of the galactomannan from Adenanthera pavonina L. seeds, as well as the typical polysaccharide bands and peaks, confirmed by literature data. The impedance results give an increment on the state-of-the-art of this biomaterial by showing the existence of dielectric relaxations, independent of the degree of purification, using the dielectric modulus formalism. The permittivity analysis reveals the presence of water in the structure of the film, whose dipoles contribute to the relatively high value of the dielectric constant. From the results obtained, it can be concluded that purified galactomannan has the potential for possible applications in the electronics industry as a green and eco-friendly dielectric material.

Assuntos

RESUMO

The association between exposure to air pollutants and respiratory diseases is well known. This study aimed to identify the association between this exposure and hospitalizations for COVID-19 in São José dos Campos, SP, a medium-sized city, between April 2020 and April 2021. Hospitalization data, concerning code B34.2, was supplied by DATASUS, and data concerning pollutants and climate variables were supplied by CETESB. Cases were quantified by sex, age, length of hospital stay in days, and type of discharge, whether hospital discharge or death. The negative binomial regression model was chosen. Estimates were produced for the relative risk (RR) of significant exposure to pollutants (P≤0.05) with a 10 µg/m3 increase of pollutant, as well as for excess hospitalizations. There were 1873 hospitalizations, with a daily average of 4.7 (±3.8), ranging from zero to 21: 716 deaths (38.2%) were recorded, 1065 admissions were men, and women were less susceptible (OR=0.82). The average age of women was higher than that of men; in cases of death, men were older than women; discharged patients were younger. All the above variables were significant. The risk of ozone exposure was higher and more significant in Lag 2, and the risk of nitrogen dioxide exposure was high in Lag 3, which was the period of the highest increase in hospitalizations, at 11.3%. The findings of this study, the first conducted in Brazil, corroborate the results of studies conducted in other centers.

Assuntos

RESUMO

Constitutional genomic imbalances are known to cause malformations, disabilities, neurodevelopmental delay, and dysmorphia and can lead to dysfunctions in the cell cycle. In extremely rare genetic conditions such as small supernumerary marker chromosomes (sSMC), it is important to understand the cellular consequences of this extra marker, as well the factors that contribute to their maintenance or elimination through successive cell cycles and phenotypic impact. The study of chromosomal mosaicism provides a natural model to characterize the effect of aneuploidy on genome stability and compare cells with the same genetic background and environment exposure, but differing in the presence of sSMC. Here, we report the functional characterization of different cell lines from two familial patients with mosaic sSMC derived from chromosome 12. We performed studies of proliferation dynamics, stability, and variability of these cells using fluorescent in situ hybridization (FISH), sister chromatid exchanges (SCE), and conventional staining. We also quantified the telomere-related genomic instability of sSMC cells using 3D telomeric profile analysis by quantitative-FISH. sSMC cells exhibited differences in the cell cycle dynamics compared to normal cells. First, the sSMC cells exhibited lower proliferation index and higher frequency of SCE than normal cells, associated with a higher level of chromosomal instability. Second, sSMC cells exhibited more telomeric-related genomic instability. Lastly, the differences of sSMC cells distribution among tissues could explain different phenotypic repercussions observed in patients. These results will help in our understanding of the sSMC stability, maintenance during cell cycle, and the cell cycle variables involved in the different phenotypic manifestations.

Assuntos

RESUMO

Raman spectroscopy and synchrotron radiation X-ray diffraction have been used to study the effect of pressure on 2-(-α-methylbenzylamino)-5-dinitropyridine (MBANP). Several changes are observed with increasing pressure in the Raman spectra of this system, such as splitting of various bands and disappearance of bands. Discontinuous shifts in wavenumber vs pressure plot indicate that a conformational phase transition takes place around 0.5 GPa. The behavior of the Raman spectra indicates that MBANP molecules present conformational phase transition at high-pressure. X-ray diffraction, performed with synchrotron radiation, confirms the conformational changes observed by Raman experiments around 0.5 GPa. The pressure provokes a rotational movement of the benzene ring which can be associated with the conformational phase transition.

Assuntos

RESUMO

Tris(glycinato)chromium(III) monohydrate [Cr(C2H4NO2)3·H2O] crystals were grown through the slow solvent evaporation method. The crystals were studied by Fourier transform infrared (FTIR) and Raman spectroscopy at room temperature. The assignments of vibration modes were performed using the Density Functional Theory (DFT). Thermal analyses (TGA, DTA, and DSC), X-ray diffraction (XRD), and Raman were used to study the phase changes on the crystals under high- and low-temperature conditions. Temperature-dependent XRPD measurements were carried out in the interval of 473-12 K. Several changes were observed in the patterns, like the appearance of new peaks and the disappearance of peaks occurring within 373-393 K due to water loss. In addition, the Raman measurements were performed in the 423-10 K interval. Several changes on the inter and intramolecular vibration bands during the cooling, such as decreasing bands' intensities, the appearance of vibration modes, and discontinuities on the modes' behavior, were observed. These spectral modifications occurred at about 370 K and within 120-220 K, thus, confirming that the crystals undergo two phase changes, one being structural and the other one conformational, respectively, at high- temperature and low-temperature conditions. Finally, thermal investigations corroborated the structural and vibrational results under high temperatures.

RESUMO

Chloro(glycinato-N,O)(1,10-phenanthroline-N,N')­copper(II) trihydrate complex was synthesized through the slow evaporation method. The crystal's structural, thermal, magnetic, and vibrational properties were obtained by X-ray powder diffraction (XRPD), thermal analyses, magnetization, Raman, and Fourier-transform infrared (FT-IR) spectroscopy. XRPD results showed that the crystalline complex belongs to a monoclinic system (P21/n). Thermal analyses revealed that around 333 K, the material undergoes a thermodynamically irreversible process. Magnetic data showed a paramagnetic behavior with weak ferromagnetic interactions. Moreover, all the Raman- and infrared-active bands were assigned from computational calculations based on the density functional theory (DFT) to analyze intra-molecular vibrational modes. In addition, the cytotoxic assay on colorectal cancer cells was performed to evaluate the antitumor activity of this ternary compound. Therefore, the antineoplastic activity of [Cu(1,10-phenanthroline)(glycine)Cl]•3H2O complex in HCT-116 cells was confirmed, showing a potent cytotoxic effect.

Assuntos

RESUMO

Constitutional genomic imbalances are known to cause malformations, disabilities, neurodevelopmental delay, and dysmorphia and can lead to dysfunctions in the cell cycle. In extremely rare genetic conditions such as small supernumerary marker chromosomes (sSMC), it is important to understand the cellular consequences of this extra marker, as well the factors that contribute to their maintenance or elimination through successive cell cycles and phenotypic impact. The study of chromosomal mosaicism provides a natural model to characterize the effect of aneuploidy on genome stability and compare cells with the same genetic background and environment exposure, but differing in the presence of sSMC. Here, we report the functional characterization of different cell lines from two familial patients with mosaic sSMC derived from chromosome 12. We performed studies of proliferation dynamics, stability, and variability of these cells using fluorescent in situ hybridization (FISH), sister chromatid exchanges (SCE), and conventional staining. We also quantified the telomere-related genomic instability of sSMC cells using 3D telomeric profile analysis by quantitative-FISH. sSMC cells exhibited differences in the cell cycle dynamics compared to normal cells. First, the sSMC cells exhibited lower proliferation index and higher frequency of SCE than normal cells, associated with a higher level of chromosomal instability. Second, sSMC cells exhibited more telomeric-related genomic instability. Lastly, the differences of sSMC cells distribution among tissues could explain different phenotypic repercussions observed in patients. These results will help in our understanding of the sSMC stability, maintenance during cell cycle, and the cell cycle variables involved in the different phenotypic manifestations.

RESUMO

The association between exposure to air pollutants and respiratory diseases is well known. This study aimed to identify the association between this exposure and hospitalizations for COVID-19 in São José dos Campos, SP, a medium-sized city, between April 2020 and April 2021. Hospitalization data, concerning code B34.2, was supplied by DATASUS, and data concerning pollutants and climate variables were supplied by CETESB. Cases were quantified by sex, age, length of hospital stay in days, and type of discharge, whether hospital discharge or death. The negative binomial regression model was chosen. Estimates were produced for the relative risk (RR) of significant exposure to pollutants (P≤0.05) with a 10 µg/m3 increase of pollutant, as well as for excess hospitalizations. There were 1873 hospitalizations, with a daily average of 4.7 (±3.8), ranging from zero to 21: 716 deaths (38.2%) were recorded, 1065 admissions were men, and women were less susceptible (OR=0.82). The average age of women was higher than that of men; in cases of death, men were older than women; discharged patients were younger. All the above variables were significant. The risk of ozone exposure was higher and more significant in Lag 2, and the risk of nitrogen dioxide exposure was high in Lag 3, which was the period of the highest increase in hospitalizations, at 11.3%. The findings of this study, the first conducted in Brazil, corroborate the results of studies conducted in other centers.

RESUMO

A patient was referred, after neoadjuvant chemotherapy, for pre-surgical evaluation of urothelial bladder carcinoma (single lesion). Two thickenings in the left ureter wall identified on the CT scan were equivocal for malignancy. 18F-FDG PET/CT with delayed pelvic images, hyperhydration, and furosemide showed hypermetabolic ureteral metastases and multifocal bladder tumors. There were no lymph nodes or distant metastases. These 18F-FDG PET/CT findings completely altered the surgical treatment. The patient underwent left nephroureterectomy, radical cystoprostatectomy, and lymphadenectomy, followed by a urinary transit reconstruction. Histopathology confirmed multifocal high-grade urothelial carcinoma in the bladder walls and left ureter and benign lymph nodes.