Cobalt oxide nanoparticles were prepared via green chemistry route and fully characterized by Field Emission Scanning Electron Microscope (FESEM), Energy-dispersive X-ray spectroscopy (EDAX), X-ray diffraction (XRD), High-resolution transmission electron microscopy (HRTEM) and Transmission electron microscopy (TEM) analyses; the CoO and Co3O4 nanoparticles, in sheet-shaped cobalt oxide form, ensued simultaneously in one step. The varying concentrations of NPs were analyzed via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test on the cancer cell line (U87) which revealed that with increasing concentration of cobalt oxide nanoparticles, the survival rate of U87 tumor cells decreases; IC50 of nanoparticles being ~ 55 µg/ml-1.
- MeSH
- Anti-Bacterial Agents chemistry MeSH
- X-Ray Diffraction MeSH
- Inhibitory Concentration 50 MeSH
- Cobalt chemistry MeSH
- Hydrogen-Ion Concentration MeSH
- Metal Nanoparticles chemistry MeSH
- Humans MeSH
- Magnetics MeSH
- Microbial Sensitivity Tests MeSH
- Cell Line, Tumor MeSH
- Nanomedicine methods MeSH
- Nanotechnology methods MeSH
- Oxides chemistry MeSH
- Surface-Active Agents MeSH
- Antineoplastic Agents pharmacology MeSH
- Plant Extracts MeSH
- Rosmarinus MeSH
- Solubility MeSH
- Spectroscopy, Fourier Transform Infrared MeSH
- Green Chemistry Technology methods MeSH
- Temperature MeSH
- Tetrazolium Salts chemistry MeSH
- Thiazoles chemistry MeSH
- Microscopy, Electron, Transmission MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
In this study, a GC-MS method was developed for the quantification of saccharides in complex mixtures such as bio-oils and bio-oil aqueous phases produced by ablative pyrolysis of lignocellulosic biomass. The samples were first treated using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and the trimethylsilylated (more volatile) derivatives were analyzed by GC-MS. The method offers advantages of great separation capability and simultaneous identification of unknown peaks by comparison of the mass spectra and retention indices with extensive libraries available online. However, even with these tools at hand, the identification of several saccharide-resembling compounds can be challenging especially in such highly complex samples as pyrolysis bio-oils. For this reason, we devised a novel procedure, which eliminates certain saccharides depending on their specific chemical properties before subjecting the samples to the GC-MS analysis. The procedure was based on the combination of aniline treatment (elimination of reducing aldoses), and hydrolysis (elimination of anhydrosugars, glycosides, disaccharides and oligosaccharides). Based on the differences in chromatograms before and after the procedure, the unknown compounds were assigned into groups based on their susceptibility to each treatment. The combination of all methods above has allowed more accurate identification and quantification of saccharides, some of which were not as of today found in bio-oils.
Ecdysteroids (ECs) are steroid hormones originally found in the animal kingdom where they function as insect molting hormones. Interestingly, a relatively high number of these substances can also be formed in plant cells. Moreover, ECs have certain regulatory effects on plant physiology, but their role in plants still requires further study. One of the main aims of the present study was to verify a hypothesis that fenarimol, an inhibitor of the biosynthesis of ECs in the animal kingdom, also affects the content of endogenous ECs in plants using winter wheat Triticum aestivum L. as a model plant. The levels of endogenous ECs in winter wheat, including the estimation of their changes during a course of different temperature treatments, have been determined using a sensitive analytical method based on UHPLC-MS/MS. Under our experimental conditions, four substances of EC character were detected in the tissue of interest in amounts ranging from less than 1 to over 200 pg·g-1 FW: 20-hydroxyecdysone, polypodine B, turkesterone, and isovitexirone. Among them, turkesterone was observed to be the most abundant EC and accumulated mainly in the crowns and leaves of wheat. Importantly, the level of ECs was observed to be dependent on the age of the plants, as well as on growth conditions (especially temperature). Fenarimol, an inhibitor of a cytochrome P450 monooxygenase, was shown to significantly decrease the level of naturally occurring ECs in experimental plants, which may indicate its potential use in studies related to the biosynthesis and physiological function of these substances in plants.
- MeSH
- Biological Products chemistry metabolism MeSH
- Chromatography, Liquid methods MeSH
- Ecdysteroids biosynthesis chemistry MeSH
- Plant Leaves drug effects metabolism MeSH
- Molecular Structure MeSH
- Fungicides, Industrial pharmacology MeSH
- Triticum growth & development metabolism MeSH
- Pyrimidines pharmacology MeSH
- Tandem Mass Spectrometry methods MeSH
- Temperature MeSH
- Publication type
- Journal Article MeSH
Plant survival in temperate zones requires efficient cold acclimation, which is strongly affected by light and temperature signal crosstalk, which converge in modulation of hormonal responses. Cold under low light conditions affected Arabidopsis responses predominantly in apices, possibly because energy supplies were too limited for requirements of these meristematic tissues, despite a relatively high steady-state quantum yield. Comparing cold responses at optimal light intensity and low light, we found activation of similar defence mechanisms-apart from CBF1-3 and CRF3-4 pathways, also transient stimulation of cytokinin type-A response regulators, accompanied by fast transient increase of trans-zeatin in roots. Upregulated expression of components of strigolactone (and karrikin) signalling pathway indicated involvement of these phytohormones in cold responses. Impaired response of phyA, phyB, cry1 and cry2 mutants reflected participation of these photoreceptors in acquiring freezing tolerance (especially cryptochrome CRY1 at optimal light intensity and phytochrome PHYA at low light). Efficient cold acclimation at optimal light was associated with upregulation of trans-zeatin in leaves and roots, while at low light, cytokinin (except cis-zeatin) content remained diminished. Cold stresses induced elevation of jasmonic acid and salicylic acid (in roots). Low light at optimal conditions resulted in strong suppression of cytokinins, jasmonic and salicylic acid.
Diazirine-tagged d- and l-adrenaline derivatives formed abundant noncovalent gas-phase ion complexes with peptides N-Ac-SSIVSFY-NH2 (peptide S) and N-Ac-VYILLNWIGY-NH2 (peptide V) upon electrospray ionization. These peptide sequences represent the binding motifs in the β2-adrenoreceptor. The structures of the gas-phase complexes were investigated by selective laser photodissociation of the diazirine chromophore at 354 nm, which resulted in a loss of N2 and formation of a transient carbene intermediate in the adrenaline ligand without causing its expulsion. The photolyzed complexes were analyzed by collision-induced dissociation (CID-MS3 and CID-MS4) in an attempt to detect cross-links and establish the binding sites. However, no cross-linking was detected in the complexes regardless of the peptide and d- or l-configuration in adrenaline. Cyclic ion mobility measurements were used to obtain collision cross sections (CCS) in N2 for the peptide S complexes. These showed identical values, 334 ± 0.9 Å2, for complexes of the l- and d-adrenaline derivatives, respectively. Identical CCS were also obtained for peptide S complexes with natural l- and d-adrenaline, 317 ± 1.2 Å2, respectively. Born-Oppenheimer molecular dynamics (BOMD) in combination with full geometry optimization by density functional theory calculations provided structures for the complexes that were used to calculate theoretical CCS with the ion trajectory method. A close match (337 Å2) was found for a single low Gibbs energy structure that displayed a binding pocket with Ser 2 and Ser 5 residues forming hydrogen bonds to the adrenaline catechol hydroxyls. Analysis of the BOMD trajectories revealed a small number of contacts between the incipient carbene carbon atom in the ligand and X-H bonds in the peptide, which was consistent with the lack of cross-linking. Temperature dependence of the internal dynamics of peptide S-adrenaline complexes as well as the specifics of the adrenaline carbene reactions are discussed. In particular, peptide amide hydrogen transfer to the carbene carbon atom was calculated to require crossing a potential energy barrier, which may hamper cross-linking in competition with carbene internal rearrangements.
- MeSH
- Epinephrine metabolism MeSH
- Amino Acid Motifs MeSH
- Receptors, Adrenergic, beta-2 metabolism MeSH
- Photochemistry MeSH
- Ion Mobility Spectrometry methods MeSH
- Humans MeSH
- Methane analogs & derivatives MeSH
- Molecular Structure MeSH
- Peptide Fragments metabolism radiation effects MeSH
- Gases MeSH
- Cross-Linking Reagents MeSH
- Stereoisomerism MeSH
- Density Functional Theory MeSH
- Temperature MeSH
- Protein Binding MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Comparative Study MeSH
Knowledge of the active pharmaceutical ingredient (API) solubility in a polymer is imperative for successful amorphous solid dispersion design and formulation but acquiring this information at storage temperature is challenging. Various solubility determination methods have been established, which utilize differential scanning calorimetry (DSC). In this work, three commonly used DSC-based protocols [i.e., melting point depression (MPD), recrystallization, and zero-enthalpy extrapolation (Z-EE)] and a method that we have developed called "step-wise dissolution" (S-WD) were analyzed. For temperature-composition phase diagram construction, two glass-transition temperature equations (i.e., those of Gordon-Taylor and Kwei) and three solid-liquid equilibrium curve modeling approaches [i.e., the Flory-Huggins model, an empirical equation, and the perturbed-chain statistical associating fluid theory (PC-SAFT) equation of state (EOS)] were considered. Indomethacin (IND) and Kollidon 12 PF (PVP K12) were selected as the API and polymer, respectively. An annealing time investigation revealed that the IND-PVP K12 dissolution process was remarkably faster than demixing, which contradicted previously published statements. Thus, the recrystallization method overestimated the solubility of IND in PVP K12 when a 2-h time of annealing was set as the benchmark. Likewise, the MPD and Z-EE methods overestimated the API solubility because of unreliable IND melting endotherm evaluation at lower API loadings and a relatively slow heating rate, respectively. When the experimental results obtained using the S-WD method (in conjunction with the Kwei equation) were applied to the PC-SAFT EOS, which was regarded as the most reliable combination, the predicted IND solubility in PVP K12 at T = 25 °C was approximately 40 wt %. When applicable, the S-WD method offers the advantage of using a limited number of DSC sample pans and API-polymer physical mixture compositions, which is both cost- and time-effective.
- MeSH
- Models, Chemical MeSH
- Calorimetry, Differential Scanning MeSH
- Chemistry, Pharmaceutical methods MeSH
- Crystallization MeSH
- Polymers chemistry MeSH
- Excipients chemistry MeSH
- Solubility MeSH
- Transition Temperature MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Comparative Study MeSH
The interactions of epoxiconazole and prothioconazole with human serum albumin and bovine serum albumin were investigated using spectroscopic methods complemented with molecular modeling. Spectroscopic techniques showed the formation of pesticide/serum albumin complexes with the static type as the dominant mechanism. The association constants ranged from 3.80 × 104-6.45 × 105 L/mol depending on the pesticide molecule (epoxiconazole, prothioconazole) and albumin type (human or bovine serum albumin). The calculated thermodynamic parameters revealed that the binding of pesticides into serum albumin macromolecules mainly depended on hydrogen bonds and van der Waals interactions. Synchronous fluorescence spectroscopy and the competitive experiments method showed that pesticides bind to subdomain IIA, near tryptophan; in the case of bovine serum albumin also on the macromolecule surface. Concerning prothioconazole, we observed the existence of an additional binding site at the junction of domains I and III of serum albumin macromolecules. These observations were corroborated well by molecular modeling predictions. The conformation changes in secondary structure were characterized by circular dichroism, three-dimensional fluorescence, and UV/VIS absorption methods.
- MeSH
- Circular Dichroism methods MeSH
- Epoxy Compounds chemistry MeSH
- Spectrometry, Fluorescence methods MeSH
- Hydrophobic and Hydrophilic Interactions MeSH
- Humans MeSH
- Serum Albumin, Human chemistry MeSH
- Pesticides chemistry MeSH
- Protein Structure, Secondary MeSH
- Serum Albumin, Bovine chemistry MeSH
- Molecular Docking Simulation methods MeSH
- Cattle MeSH
- Static Electricity MeSH
- Temperature MeSH
- Triazoles chemistry MeSH
- Protein Binding MeSH
- Binding Sites MeSH
- Hydrogen Bonding MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Cattle MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
BACKGROUND: The numbers of coronavirus disease 2019 (COVID-19) deaths per million people differ widely across countries. Often, the causal effects of interventions taken by authorities are unjustifiably concluded based on the comparison of pure mortalities in countries where interventions consisting different strategies have been taken. Moreover, the possible effects of other factors are only rarely considered. METHODS: We used data from open databases (European Centre for Disease Prevention and Control, World Bank Open Data, The BCG World Atlas) and publications to develop a model that could largely explain the differences in cumulative mortality between countries using non-interventional (mostly socio-demographic) factors. RESULTS: Statistically significant associations with the logarithmic COVID-19 mortality were found with the following: proportion of people aged 80 years and above, population density, proportion of urban population, gross domestic product, number of hospital beds per population, average temperature in March and incidence of tuberculosis. The final model could explain 67% of the variability. This finding could also be interpreted as follows: less than a third of the variability in logarithmic mortality differences could be modified by diverse non-pharmaceutical interventions ranging from case isolation to comprehensive measures, constituting case isolation, social distancing of the entire population and closure of schools and borders. CONCLUSIONS: In particular countries, the number of people who will die from COVID-19 is largely given by factors that cannot be drastically changed as an immediate reaction to the pandemic and authorities should focus on modifiable variables, e.g. the number of hospital beds.
- MeSH
- COVID-19 mortality MeSH
- Adult MeSH
- HIV Infections epidemiology MeSH
- Gross Domestic Product MeSH
- Population Density MeSH
- Incidence MeSH
- Comorbidity MeSH
- Smoking epidemiology MeSH
- Middle Aged MeSH
- Humans MeSH
- Urban Population statistics & numerical data MeSH
- Adolescent MeSH
- Overweight epidemiology MeSH
- Bed Occupancy MeSH
- Pandemics prevention & control MeSH
- Delivery of Health Care organization & administration MeSH
- Prevalence MeSH
- SARS-CoV-2 * MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Socioeconomic Factors MeSH
- Temperature MeSH
- Tuberculosis epidemiology MeSH
- Age Distribution MeSH
- Public Health MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Adolescent MeSH
- Male MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Europe MeSH
Accurate identification and analysis of signs of trauma on human bone is one of the mainstays of forensic pathology. However, when a forensic pathologist has to deal with charred remains, the task become extremely difficult, because tissues are subjected to severe morphological alterations and their assessment can be critically distorted. We analyzed 38 individuals with peri-mortem skull fractures due to falls from height (17 cases), traffic accidents (16 cases), gunshots wounds (5 cases), of which we had the demographic and clinical data and the autopsy report with the description and photographic records of the fracture lines. After autopsy, the bodies were cremated in gas furnaces and the analysis of cremated cranial remains was conducted in order to verify if it was possible to reconstruct the original peri-mortem fractures and verify differences between known peri-mortem and post-mortem fractures. After 90 min and exposure to temperatures up to 1280 °C, in less than a third of cases (11-29%) the original peri-mortem fracture pattern could be found and reconstructed. The edges and the surface of the fractures can preserve their proper morphology, or they can be affected by post-mortem heat-induced fractures and deformations. Interestingly whenever peri-mortem fracture margins showed the evidence of yellow/brownish colouration, a matte appearance was observed, much different from post-mortem fractures, which may provide further food for thought for the identification of peri-mortem fractures after the cremation process.
- MeSH
- Skull Fractures etiology pathology MeSH
- Cremation * MeSH
- Humans MeSH
- Autopsy MeSH
- Postmortem Changes * MeSH
- Forensic Pathology methods MeSH
- Body Remains pathology MeSH
- Hot Temperature * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
The risks of depletion of energy reserves and encountering lethally low temperatures are considered as two important mortality factors that may limit winter survival of mosquito, Culex pipiens f. pipiens populations. Here we show that the autumn females carry lipid reserves, which are safely sufficient for at least two overwintering periods, provided the females diapausing at temperatures typical for underground spaces (0 °C - 8 °C) would continuously rest at a standard metabolic rate (SMR). The overwintering females, however, switch from SMR to much higher metabolic rate during flight, either seeking for optimal microhabitat within the shelter or in response to disturbances by air current or predator attack. These behaviors result in fast oxidation of lipid reserves and, therefore, the autumn load of energy reserves may actually limit winter survival under specific circumstances. Next, we show that the level of females' cold hardiness is physiologically set relatively weak for overwintering in open field, above-ground habitats, but is ecologically entirely sufficient for overwintering in most underground spaces. The characteristics of suitable overwintering shelters are: no or limited risk of contact with ice crystals, no or limited air movements, winter temperatures relatively stable between +2 and + 6 °C, winter minimum does not drop below -4 °C for longer than one week, or below -8 °C for longer than 1 day.
- MeSH
- Culex metabolism physiology MeSH
- Diapause MeSH
- Energy Metabolism * MeSH
- Lipid Metabolism MeSH
- Cold Temperature * MeSH
- Seasons * MeSH
- Animals MeSH
- Check Tag
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
