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This paper deals with some new arguments corroborating the absence of carbonyl moieties [1] in the chemical structure of hypercrosslinked polystyrenes in spite of the high intensity of the absorption band around 1700 cm super(-1) in their FTIR spectra. Three additional facts testify to the benefit of this conclusion. First is the appearance of the absorbance band at 1700 cm super(-1) in a computer-simulated IR spectrum of a rigid highly crosslinked model network that contains no C=O groups. Second, thermal degradation of the hypercrosslinked network with a formal 500% crosslinking density results in emergence in its mass-spectrum of benzene, alkylbenzenes and hydrogen chloride, only. Third, testing the above hypercrosslinked polystyrene as a stationary phase in a GC column shows the polymer to retain aliphatic hydrocarbons, alcohols and ketones largely by dispersion interactions, thus revealing no polar oxygen-containing groups on its surface.

Special attention is given to the pharmacological treatment of combined medication of Carvedilol and hydrochlorothiazide which is the most effective and the most beneficial therapy for hypertensive patients with diabetes and various metabolic comorbidities. This work represents spectrophotometric platform scenarios based on factorized spectrum (FS) using interpoint data difference resolution scenarios (IDDRS) coupled with spectrum subtraction method (SS) for the concurrent quantification of carvedilol (CAR) and hydrochlorothiazide (HCT) when present together in a combination without the need for any initial physical separation steps. This IDD resolution scenario based on manipulating the zero-order spectra (D 0 ) of both drugs in the mixture with various spectral features at different wavelength regions (200–400 nm), region I (220–250 nm), region II (240–300 nm) and region III (270–320 nm) via absorbance resolution (AR) and induced absorbance resolution (IAR) methods coupled with corresponding spectrum subtraction (SS). The calibration curves were established across the linearity ranges of 2.0–12.0 µg/mL at 242.50 nm and 4.0–40.0 µg/mL at 285.5 nm for CAR and 1.0–11.0 µg/mL at 226.10 nm and 2.0–20.0 µg/mL at 270.5 nm for HCT. Moreover, methods’ validation was confirmed via ICH guidelines. A Multicenter comparison between sensitivity, specificity in respect resolution sequence were applied using different wavelength regions with various concentration ranges was applied and finally spectral resolution recommendation is issued and cumulative validation score (CVS) is calculated as an indicator in the risk analysis. In quality control laboratories, the studied approaches are applicable for conducting analysis on the mentioned drugs. In addition, the selection of spectrophotometry aligns with the principles of green analytical chemistry, an approach that resonates with the overarching theme of minimizing environmental impact. Via four metric tools named: analytical greenness (AGREE), green analytical procedure index (GAPI), analytical eco-scale, and national environmental method index (NEMI), methods’ greenness profile was guaranteed.

Fast and accurate determination of the protein content of a sample is an important and non-trivial task of many biochemical, biomedical, food chemical, pharmaceutical, and environmental research activities. Different methods of total protein determination are used for a wide range of proteins with highly variable properties in complex matrices. These methods usually work reasonably well for proteins under controlled conditions, but the results for non-standard and complex samples are often questionable. Here, we compare new and well-established methods, including traditional amino acid analysis (AAA), aromatic amino acid analysis (AAAA) based on the amino acids phenylalanine and tyrosine, reversed-phase liquid chromatography of intact proteins with UV absorbance measurements at 220 and 280 nm (LC-220, LC-280), and colorimetric assays like Coomassie Blue G-250 dye-binding assay (Bradford) and bicinchoninic acid (BCA) assay. We investigated different samples, including proteins with challenging properties, chemical modifications, mixtures, and complex matrices like air particulate matter and pollen extracts. All methods yielded accurate and precise results for the protein and matrix used for calibration. AAA, AAAA with fluorescence detection, and the LC-220 method yielded robust results even under more challenging conditions (variable analytes and matrices). These methods turned out to be well-suited for reliable determination of the protein content in a wide range of samples, such as air particulate matter and pollen.

Activation of PKC signaling induces Mg super(2+) accumulation in liver cells. To test the hypothesis that PKC induces Mg super(2+) accumulation via MAPKs activation, hepatocytes were incubated in the presence of PD98059 and SB202190 as specific inhibitors of ERK1/2 and p38, respectively, and stimulated for Mg super(2+) accumulation by addition of PMA or OAG. Accumulation of Mg super(2+) within the cells was measured by atomic absorbance spectrophotometry in the acid extract of cell pellet. The presence of either inhibitor completely abolished Mg super(2+) accumulation irrespective of the dose of agonist utilized while having no discernible effect on b -adrenoceptor mediated Mg super(2+) extrusion. A partial inhibition on a sub(1)-adrenoceptor mediated Mg super(2+) extrusion was observed only in cells treated with PD98059. To confirm the inhibitory effect of PD98509 and SB202190, total and basolateral liver plasma membrane vesicles were purified in the presence of either MAPK inhibitor during the isolation procedure. Consistent with the data obtained in intact cells, liver plasma membrane vesicles purified in the presence of PD98509 or SB202190 lost the ability to accumulate Mg super(2+)in exchange for intra-vesicular entrapped Na super(+) while retaining the ability to extrude entrapped Mg super(2+) in exchange for extra-vesicular Na super(+). These data indicate that ERK1/2 and p38 are involved in mediating Mg super(2+) accumulation in liver cells following activation of PKC signaling. The absence of a detectable effect of either inhibitor on b -adrenoceptor induced, Na super(+)-dependent Mg super(2+) extrusion in intact cells and in purified plasma membrane vesicles further support the hypothesis that Mg super(2+) extrusion and accumulation occur through distinct and differently regulated transport mechanisms.

To describe the characteristics of large vestibular aqueduct syndrome (LVAS) in wideband acoustic immittance (WAI) and to explore whether inner ear deformity has an impact on WAI results. Subjects with typical LVAS (LVAS group) and control subjects with a normal anatomical structure of the inner ear (control group) were screened from pediatric patients with cochlear implants using thin-slice computed tomography (CT) images of the temporal bone. With inflammation of the auditory canal and middle ear excluded by routine ear examination and 226 Hz acoustic immittance, WAI data were acquired. Then, the maximum absorbance as the major observation indicator on the mean tympanogram was compared between the LVAS group and control group, and a descriptive comparison of the mean tympanogram and frequency-absorbance curve at peak pressure was performed between the two groups. The LVAS group included 21 cases (38 ears), and the control group included 27 cases (45 ears). All LVAS subjects met the Valvassori criteria, and the VA at the horizontal semicircular canal displayed flared expansion. On the mean tympanogram, the maximum absorbance in the LVAS group (0.542 ± 0.087) was significantly higher than that in the control group (0.455 ± 0.087) ( < 0.001). The tympanogram in the LVAS group showed an overall elevation, and the absorbance at all pressure sampling points was significantly higher than that in the control group ( < 0.001). The frequency-absorbance curve at peak pressure first increased and then decreased in both groups, and the LVAS group showed higher absorbance than the control group in the frequency range below 2,828 Hz. The absorbance at 343-1,124 Hz was significantly different between the two groups ( < 0.001), and 343-1,124 Hz was the major frequency range at which the maximum absorbance on the mean tympanogram increased in the LVAS group. Large vestibular aqueduct syndrome (LVAS) shows increased absorbance in low and medium frequency ranges in WAI. The maximum absorbance on the mean tympanogram can serve as a reliable evaluation indicator. Inner ear factors must be considered when middle ear lesions are analyzed by WAI.

This is the first time we report that simply air plasma treatment can also enhances the optical absorbance and absorption region of titanium oxide (TiO 2 ) films, while keeping them transparent. TiO 2 thin films having moderate doping of Fe and Co exhibit significant enhancement in the aforementioned optical properties upon air plasma treatment. The moderate doping could facilitate the formation of charge trap centers or avoid the formation of charge recombination centers. Variation in surface species viz. Ti 3+ , Ti 4+ , O 2− , oxygen vacancies, OH group and optical properties was studied using X-ray photon spectroscopy (XPS) and UV-Vis spectroscopy. The air plasma treatment caused enhanced optical absorbance and optical absorption region as revealed by the formation of Ti 3+ and oxygen vacancies in the band gap of TiO 2 films. The samples were treated in plasma with varying treatment time from 0 to 60 seconds. With the increasing treatment time, Ti 3+ and oxygen vacancies increased in the Fe and Co doped TiO 2 films leading to increased absorbance; however, the increase in optical absorption region/red shift (from 3.22 to 3.00 eV) was observed in Fe doped TiO 2 films, on the contrary Co doped TiO 2 films exhibited blue shift (from 3.36 to 3.62 eV) due to Burstein Moss shift.

Bark from trees is considered a worthless raw material. However, this resource could be economically beneficial if utilized efficiently due to its rich chemical compounds. In this study, an ethanol toluene-soluble extractive, alpha-cellulose and lignin obtained from Leucaena leucocephala bark were characterized to determine their chemical functional groups. Based on FTIR spectral analysis, the results indicated that the bands of the functional groups of the extractive from the original bark remain unchanged; however, the absorbance intensity was found to be weaker in the group frequency and fingerprint regions. Removal of extractive, pectin, hemicellulose and lignin from the bark indirectly increased the strong absorbance intensity of cellulose. Broad peaks of OH stretching found in all spectra were assigned to the presence of phenolic OH and aliphatic structures for extractive and aromatic structures of lignin. It was revealed that aromatic functional groups were mainly found in the extractive, while water, carbonyl and ether were the dominant groups in cellulose, and methyl, methylene, carbonyl and carboxyl groups were enriched in lignin. Graphic abstract

Technology for rapid, non-invasive and accurate determination of fruit maturity is increasingly sought after in horticultural industries. This study investigated the ability to predict fruit maturity of yellow peach cultivars using a prototype non-destructive fluorescence spectrometer. Collected spectra were analysed to predict flesh firmness (FF), soluble solids concentration (SSC), index of absorbance difference (IAD), skin and flesh colour attributes (i.e., a* and H°) and maturity classes (immature, harvest-ready and mature) in four yellow peach cultivars—‘August Flame’, ‘O’Henry’, ‘Redhaven’ and ‘September Sun’. The cultivars provided a diverse range of maturity indices. The fluorescence spectrometer consistently predicted IAD and skin colour in all the cultivars under study with high accuracy (Lin’s concordance correlation coefficient > 0.85), whereas flesh colour’s estimation was always accurate apart from ‘Redhaven’. Except for ‘September Sun’, good prediction of FF and SSC was observed. Fruit maturity classes were reliably predicted with a high likelihood (F1-score = 0.85) when samples from the four cultivars were pooled together. Further studies are needed to assess the performance of the fluorescence spectrometer on other fruit crops. Work is underway to develop a handheld version of the fluorescence spectrometer to improve the utility and adoption by fruit growers, packhouses and supply chain managers.