In this paper, novel mixed Tutton salts with the chemical formulas K2Mn0.03Ni0.97(SO4)2(H2O)6 and K2Mn0.18Cu0.82(SO4)2(H2O)6 were synthesized and studied as compounds for thermochemical heat storage ...potential. The crystallographic structures of single crystals were determined by X-ray diffraction. Additionally, a comprehensive computational study, based on density functional theory (DFT) calculations and Hirshfeld surface analysis, was performed to calculate structural, electronic, and thermodynamic properties of the coordination complexes MII(H2O)62+ (MII = Mn, Ni, and Cu), as well as to investigate intermolecular interactions and voids in the framework. The axial compressions relative to octahedral coordination geometry observed in the crystal structures were correlated and elucidated using DFT investigations regarding Jahn–Teller effects arising from complexes with different spin multiplicities. The spatial distributions of the frontier molecular orbital and spin densities, as well as energy gaps, provided further insights into the stability of these complexes. Thermogravimetry, differential thermal analysis, and differential scanning calorimetry techniques were also applied to identify the thermal stability and physicochemical properties of the mixed crystals. Values of dehydration enthalpy and storage energy density per volume were also estimated. The two mixed sulfate hydrates reported here have low dehydration temperatures and high energy densities. Both have promising thermal properties for residential heat storage systems, superior to the Tutton salts previously reported.
Saturated monocarboxylic fatty acids with long carbon chains are organic compounds widely used in several applied fields, such as energy production, thermal energy storage, antibactericidal, ...antimicrobial, among others. In this research, a new polymorphic phase of arachidic acid (AA) crystal was synthesized and its structural and vibrational properties were studied by single-crystal X-ray diffraction (XRD) and polarized Raman scattering. The new structure of AA was solved at two different temperature conditions (100 and 300 K). XRD analysis indicated that this polymorph belongs to the monoclinic space group
P
2
1
/
c
(
C
2h
5
), with four molecules per unit cell (
Z
= 4). All molecules in the crystal lattice adopt a
gauche
configuration, exhibiting a
R
2
2
(8) hydrogen bond pattern. Consequently, this new polymorphic phase, labeled as B form, is a polytype belonging to the monoclinic symmetry,
i.e
., B
m
form. Complementarily, Hirshfeld's surfaces were employed to analyze the intermolecular interactions within the crystal lattice of this polymorph at temperatures of 100 and 300 K. Additionally, density functional theory (DFT) calculations were performed to assign all intramolecular vibration modes related to experimental Raman-active bands, which were properly calculated using a dimer model, considering a pair of AA molecules in the
gauche
configuration, according to the solved-crystal structure.
A new polymorphic phase of arachidic acid crystal, and its structure, intermolecular interactions, and vibrational properties.
The September 6–10, 2017 two-step magnetic storm was caused by an X9 solar flare followed by a CME. The SSC that occurred at 23:43 UT on day 06 when Sym-H reached about 50 nT, was due to a sudden ...increase in solar wind. The first step of the storm was caused by a
B
z
southward incursion on day 07. The magnetic index
K
p
reached 08, and the Sym-H magnetic index reached a minimum value of − 146 nT on day 08 at 01:08 UT, ending the main phase. On day 07, the solar wind intensified once again and the auroral index AE reached 2500 nT. During the recovery phase of this first storm, there was another
B
z
southward incursion on day 08 at 13:56 UT when Sym-H reached − 115 nT, and
K
p
reached a value of 08.33, marking the second step of the storm. In this work, the ionospheric irregularity over São Luís (02.5°S, 44.3°W, dip lat − 04.67°) was studied using data from the VHF, Digisonde and GPS receivers. Electron density data from the satellite SWARM-A were also analyzed for those orbits close to São Luís, and they presented large fluctuations during the storm night of 07/08. To analyze the latitudinal effects of the storm on the plasma irregularities, GPS data from 6 Novatel receivers were used. The vertical plasma drifts during daytime hours were determined using magnetometer data and during the evening using ionogram data. Compared to the ‘quiet’ days of September 2017, the VHF and GPS S4 amplitude scintillation indices increased substantially during the night of 07/08 when there was a strong intensification in the vertical plasma drift due to a prompt penetration under shielding magnetospheric electric field of eastward polarity. On the other hand, on the night of 08/09 the ionospheric scintillation was completely inhibited due to the disturbance dynamo electric field of westward polarity associated with the first and second storms. The irregularity zonal drifts measured by a VHF receiver around 24 UT (21 LT) were eastward on the nights of 05/06 and 06/07; however, during the night of 07/08, it reversed to westward.
The present work reports the antitumor activity and a comprehensive study of the Cu(II) complex with 1,10-phenanthroline and
l
-tyrosine, synthesized by slow solvent evaporation method. X-ray powder ...diffraction (XRPD) showed that the complex crystallizes in a monoclinic structure with
P
2
1
/c
-space group. All IR- and Raman-active bands were assigned and vibrational properties were evaluated under solvation effects from quantum chemical calculations using density functional theory (DFT). Additionally, optimized geometry, electrostatic potential surface, spatial distribution, and energies of molecular orbitals HOMO and LUMO, as well as chemical reactivity indexes, were obtained using PBE1PBE theoretical level. Antitumor activity of the complex was evaluated through cytotoxic tests in vitro in tumor cell lines PC3 and SNB-19, presenting IC
50
equal to 1.5 μM and 2.9 μM, respectively. Additionally, ADME parameters were evaluated to study the drug-like properties of the synthesized complex. Therefore, our findings suggest that the complex presents a promising antitumor activity, with the potential to be used in cancer chemotherapy treatment.
Evaluate current recommendation for the use of noninvasive ventilation (Bi-level positive airway pressure- BiPAP modality) in hypoxemic acute respiratory failure, excluding chronic obstructive ...pulmonary disease.
Electronic searches in MEDLINE, Web of Science, Clinical Trials, and The Cochrane Central Register of Controlled Clinical Trials. We searched for randomized controlled trials comparing BiPAP to a control group in patients with hypoxemic acute respiratory failure. Endotracheal intubation and death were the assessed outcomes.
Of the 563 studies found, nine met the inclusion criteria for this systematic review. The pooled RR (95% CI) for intubation in patients with acute pulmonary edema (APE)/community acquired pneumonia (CAP) and in immunosuppressed patients (cancer and transplants) were 0.61 (0.39–0.84) and 0.77 (0.60–0.93), respectively. For Intensive Care Units (ICU) mortality, the RR (95% CI) in patients with APE/CAP was 0.51 (0.22–0.79). The heterogeneity was low in all comparisons.
NIV showed a significant protective effect for intubation in immunosuppressed patients (cancer and transplants) and in patients with APE/CAP. However, the benefits of NIV for other etiologies are not clear and more trials are needed to prove these effects.
•Noninvasive ventilation reduces the risk of intubation in subgroups of acute hypoxemic patients.•Immunosuppressed, acute pulmonary edema and pneumonia patients may benefit most from NIV.•Well designed randomized clinical trials are required to address the benefit in other populations.
Folk medicine suggests that pomegranate (peels, seeds and leaves) has anti-inflammatory properties; however, the precise mechanisms by which this plant affects the inflammatory process remain ...unclear. Herein, we analyzed the anti-inflammatory properties of a hydroalcoholic extract prepared from pomegranate leaves using a rat model of lipopolysaccharide-induced acute peritonitis. Male Wistar rats were treated with either the hydroalcoholic extract, sodium diclofenac, or saline, and 1 h later received an intraperitoneal injection of lipopolysaccharides. Saline-injected animals (i. p.) were used as controls. Animals were culled 4 h after peritonitis induction, and peritoneal lavage and peripheral blood samples were collected. Serum and peritoneal lavage levels of TNF-
as well as TNF-
mRNA expression in peritoneal lavage leukocytes were quantified. Total and differential leukocyte populations were analyzed in peritoneal lavage samples. Lipopolysaccharide-induced increases of both TNF-
mRNA and protein levels were diminished by treatment with either pomegranate leaf hydroalcoholic extract (57 % and 48 % mean reduction, respectively) or sodium diclofenac (41 % and 33 % reduction, respectively). Additionally, the numbers of peritoneal leukocytes, especially neutrophils, were markedly reduced in hydroalcoholic extract-treated rats with acute peritonitis. These results demonstrate that pomegranate leaf extract may be used as an anti-inflammatory drug which suppresses the levels of TNF-
in acute inflammation.
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•5-methyluridine hemihydrate (5 mU) crystals were obtained by slow evaporation method.•Properties and vibrational spectra calculated by DFT presented good results in comparison with ...experimental data.•5 mU crystal suffers a change from orthorhombic to triclinic system due to the exit of water from the crystalline structure.•Anhydrous system undergoes a phase change from triclinic to monoclinic system.
5-methyluridine hemihydrate (5 mU) single crystals were synthesized by the slow solvent evaporation method. The physicochemical properties, such as frontier molecular orbitals, global reactivity indices and vibrational were computationally studied through density functional theory (DFT). In addition, structural, vibrational, and thermal properties were obtained by powder X-ray diffraction (PXRD), Raman spectroscopy, thermogravimetric (TG) analysis and differential scanning calorimetry (DSC). PXRD evaluated the structural behavior of 5 mU crystal in the temperature range of 300–460 K. The high-temperature PXRD results suggested that the crystal undergoes two dehydration processes, being a first occurring from the orthorhombic structure (P21212) to triclinic (P1), in which the water losses occurred around 380 K. A second dehydration triggers the change from the triclinic structure to monoclinic (P21) within the 420–435 K temperature range. Furthermore, after this temperature, the anhydrous 5 mU suffers a melting process near 460 K, which is remarkably characterized as an irreversible process. Raman spectroscopy was carried out to identify the vibrational modes linked to the water molecule and the noticeable changes in these bands due to high-temperature effects around 380 K and 410 K. Indeed, changes on Raman bands, such as intensity inversion, the disappearance of bands associated with the hydrogen bonds formed from the water molecules and uracil group, and the ribose group were observed. Finally, this study provided details on the structural and vibrational changes caused by the dehydration of 5 mU crystals and the importance of hydrogen bonds for understanding the intermolecular interactions of the 5 mU, a methylated nucleoside with important biological functions.
In this study, X‐ray diffraction confirms the crystallization of aqua(1,10‐phenanthroline)(L‐serinato)copper(II) nitrate in the triclinic system (P‐1). Density functional theory calculations are used ...to assign the vibration bands of Cu2+ ion and phenanthroline (phen) and L‐serine (L‐ser) ligands obtained by Raman and Fourier‐transform infrared spectroscopy. Physical and analytical properties, evaluated by computational study utilizing CrystalExplorer software, show the prevalence of H···O/O···H interaction. Thermal analyses show that the complex is stable in the temperature interval of 300–390 K. For temperatures above 390 K, the elimination of coordinated water molecules (380–430 K), mass loss of serine (440–660 K), and material decomposition process above 660 K. The solubility of the complex in water reaches 21.4 mg mL−1 at 35 °C. Parameters of drug‐likeness and assessment of absorption, distribution, metabolism, and excretion (ADME) properties are calculated. The in vitro cytotoxic assays against the cancer cell line of the HCT‐116 type (human colorectal carcinoma) exhibits toxicity (IC50 = 1.88 µm and selectivity index of 2.17) for the complex. The results highlight the potential of ternary copper complexes such as Cu(phen)(L‐ser)(H2O)NO3 for anticancer drug development as attractive, efficient, and low‐cost materials.
Structural, spectroscopy, physical, and analytical properties of aqua(1,10‐phenanthroline)(L‐serinato)copper(II) nitrate complex are investigated by full Density Functional Theory‐based calculation. Vibration modes indicate the complexation of material with the prevalence of H···O/O···H interaction. The complex remains stable from 300 to 390 K. In vitro, cytotoxicity against HCT‐116 cancer cells shows an IC50 of 1.88 µm and a selectivity index of 2.17.
•L-threonine crystals with Ce3+ impurity.•Structural, vibrational, thermal and optical properties.•Ce3+ ions promote a slight expansion in the unit cell volume.•UV-Vis revealed three Ce3+ ...characteristic bands due to the 4f-5d transitions.•L-ThrCe crystal showed light emission into the ultraviolet region around 350 nm.
In this study, L-threonine (L-Thr) crystal containing Ce3+ (L-ThrCe) impurity was grown through the slow solvent evaporation method. The structural data obtained by X-ray diffraction and Rietveld's refinement revealed that the L-ThrCe crystal crystallizes in the orthorhombic structure with P212121-space group and that the Ce3+ ions probably occupy interstitial spaces within the crystal, promoting a slight expansion on the crystal unit cell volume and a slight strain increase. Fourier-transform infrared and Raman spectroscopy showed that the Ce3+ ion slightly affects the crystalline lattice. Thermal analyses indicated that the L-ThrCe crystal has stability from 300 K up to 483 K. In addition, the L-ThrCe sample showed three bands into the UV-Vis region (240, 253, and 299 nm) characteristic of Ce3+ ions due to the 4f-5d transition. From photoluminescence, it was possible to observe emission broadband with a maximum around 350 nm when excited at 255 nm, corresponding to 2D → 2F7/2, 2F5/2 transitions of the Ce3+ ion. The present study demonstrated that the L-ThrCe crystal has light emission in the ultraviolet region, and it expands the range of potential materials for optical applications.
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