Polyethylene oxide (PEO) complexed with molecular iodine (
I
2
) forming PEO/
I
2
complex composites stand‐free films were investigated using dielectric relaxation, X-ray photoelectron spectroscopy ...(XPS), UV–Vis spectrophotometry, structural and morphological techniques. Scanning electron microscopy was used to monitor the variation in the surface morphology and the related roughness. 2D Energy-dispersive X-ray spectroscopy (EDX) measurements enabled to observe the distribution of iodine on the film surface. High resolution XPS measurements were used to define the iodine anion types and the metallic iodine existence, as well as the relevant concentrations based on the binding energies. The dielectric relaxation measurements were carried out over the frequency range from 0.1 to 10
7
Hz and temperature range from 155 to 330 K. Dielectric loss (ε′′) curves were fitted to the Havriliak–Negami (HN) model for one and/or two relaxation peaks (α and β), with and without the electrical conductivity contribution term, in order to deduce the relaxation time (τ) and the dielectric strengths (Δ
ε
), in addition to the electrical conductivities (
σ
). The temperature-dependent data of β- and σ- relaxations follow the law of Arrhenius thermal activation indicating the presence of typical glass-forming polymers. Δ
ε
of α-relaxation obeys the curvature pattern of Vogel-Tammann-Fulcher (VTF) thermal activation law. The electrical conductivity of the system increases 6000 folds by doping PEO with 5 wt% of iodine at the same temperature (293 K).
This study aims to measure entrance surface doses during routine chest and abdomen x-ray examinations of adult and child patients. Radiation dose measurements were performed using thermoluminescent ...dosimeters TLD-100s in three major public hospitals in northern Jordan on a total of 100 patients. Wide variations in entrance surface doses were observed within and between hospitals, which might be attributed to significant variations of the selected exposure parameters. For adult patients, the results have shown that the majority of entrance surface dose values from both chest and abdomen examinations were within recommended values of diagnostic reference levels. For child patients, the mean entrance surface dose from chest examinations in three age groups were 0.131 mGy (0-1 y), 0.136 mGy (1-5 y), and 0.191 mGy (5-10 y). These values were considered relatively high compared to the European reference levels and published results in the literature. However, for abdomen examinations, entrance surface dose values were relatively lower than European reference levels. Patient effective doses were estimated using a PCXMC 2.0 Monte Carlo program. The results for both adults and children were found to be relatively lower than the values reported by international publications. Due to the wide variations of entrance surface dose and the higher radiation doses delivered to child patients, this study recommends implementing a quality assurance program in such hospitals to achieve optimization between good image quality and minimum dose according to the as low as reasonably achievable principle. Moreover, the results of this work will provide a useful base for establishing local diagnostic reference levels for chest and abdomen examinations in Jordan.
Background/Objective/Methods: Capsaicin micelles were prepared by the direct dissolution using the amphiphilic copolymer Pluronic P123 and advanced for substantially novel submicro-nanocytotoxicity. ...Results: Superior cytotoxicity of capsaicin loaded nanomicelles vs. both the raw capsaicin and reference cisplatin in pancreatic PANC1, breast MCF7, colorectal resistant CACO2, skin A375, lung A549 and prostate PC3 cancer cell lines were delineated. Nicotinic acid (NA) derivative 39 (2-Amino IsoNA) had antiinflammatory potential but consistently lacked antiproliferation in MCF7, PANC1 and CACO2. Besides NA derivatives 8 (5-MethylNA) and 44 (6-AminoNA) exhibited lack of antiinflammation but had comparable antitumorigenesis potency to cisplatin in PANC1 cells. Though capsaicin loaded nanomicelles exerted pronounced antiinflammation (with IC50 value of 510 nM vs. Indomethacin's) in lipopolysacchride-induced inflammation of RAW247.6 macrophages; they lacked DPPH scavenging propensities. Free capsaicin proved more efficacious vs. its loaded nanocarriers to chemosensitize cytotoxicity of combinations with NAs 1(6-Hexyloxy Nicotinic Acid), 5(6-OctyloxyNA), 8(5-MethylNA), 12(6-Thien-2yl-NA), 13(5,6-DichloroNA) and 44(6-AminoNA) in CACO2, PANC1 and prostate PC3. Conclusion: Capsaicin loaded nanomicelles proved more efficacious vs. free capsaicin to chemo-sensitize antiproliferation of cotreatments with NA derivatives, 1, 5, 8, 12, 13 and 44 (in skin A375), 1, 5, 8 and 12 (in breast MCF7), and 1, 5, 12 and 44 (in lung A549).
The tethering dynamics of PyridoPyrrole Quinoxaline (PPQ) anticancer with gold nanoparticles (AuNPs) forming the PPQ/AuNPs complex were investigated. PPQ was synthesized from various substituted ...nitro-fluoroquinolone and the resulting chemical structure was validated using high-resolution
1
H- and
13
C-NMR. The tethering in PPQ/AuNPs was activated by irradiating the samples with light at λ ~ 525 nm (surface plasmon resonance (SPR) of AuNPs) and simultaneously with electrical pulsing applied to the electrical electrodes. FTIR and UV–Vis spectroscopy as well as Density Functional Theory (DFT) modeling were used to obtain results on the PPQ/AuNPs with different PPQ concentrations. The results elucidate the formed intermolecular bonding between AuNPs with PPQ on the sites of fluorine atoms or/and hydrogen in the hydroxyl group. The absorbance spectra of PPQ/AuNPs revealed appearing new peaks at 300 nm, 386 nm, and 711 nm. FTIR spectrum was calculated using a DFT model based on tethered a single gold nanoparticle with four PPQ molecules in the fluorine sides where the optimized structure was a distorted tetrahedral geometry of bounded four PPQ molecules with AuNP as a center. The calculated FTIR spectrum was in excellent matching with the experimental FTIR spectrum. The calculated complexation energy was equal to − 3975.5 kcal/mole which is less than the sum of the energy of the PPQ (− 959.5 kcal/mol) and the AuNP (− 135.4 kcal/mol) indicating that tethering led to a stable complex. The binding energy of the PPQ/AuNPs complex deduced from the DFT calculations proved that the highest tethering stability which leads to the minimum energy is at the site of the fluorine atoms.
Purpose
To assess the transverse relaxation time T
2
and diffusion coefficient
D
before and following exercise in the tibialis anterior muscle and determine whether T
2
and
D
values were correlated.
...Methods
Measurements of T
2
and
D
were performed at 3 T within axial slices through the calf muscles of six healthy volunteers at 95 s intervals before and for 10–12 min after a dorsiflexion exercise to exhaustion.
Results
The mean ± standard deviation (SD) of T
2
and
D
before exercise were 32 ± 1.55 ms and 1.52 ± 0.15 μm
2
/ms, and after exercise were 43 ± 2.5 ms and 1.72 ± 0.13 μm
2
/ms, respectively. The mean ± SD inter-individual recovery times of the % change in T
2
and
D
after exercise were 7.9 ± 4.2 and 10.9 ± 7.0 min, respectively. The T
2
and
D
values showed a significant correlation throughout the experiments (
r
2
= 0.45).
Conclusions
The increase in T
2
of skeletal muscle after exercise is correlated with the increase of the diffusion coefficient D and the recovery times appear similar, indicating that any model used to explain T
2
increases with exercise must also account for increased diffusion coefficients.
The mechanical and thermodynamical features of LiBH4 and LiAlH4 complex hydrides in the α, β and γ phases are evaluated using density functional theory. To our knowledge, thermal parameters such as, ...the Grüneisen parameter γ, the heat capacity, and thermal expansion coefficient of LiXH4 (X = B, Al) complex hydrides in α, β and γ phases are computed for the first time. The parameters are determined in terms of pressure (0–6 GPa) and temperature (0–600) K using the quasi-harmonic Debye model. The computed stress–strain relationships effectively yield the elastic constants of a single crystal. The estimated elastic constants of α-LiBH4 compound are noticeably higher than those of several closely similar ABH4 (A = Na, K, Rb, and Cs) borohydrides. In the β-LiAlH4 tetragonal structure, the 001 direction is readily compressible as compared to the 100 direction. The compressibility modulus of the LiBH4 compound is greater than that of the LiAlH4. However, the distance between B and H is less than the distance between Al and H. This might be explained by the presence of covalent bonds in BH4 and AlH4 in LiXH4 (X = B, Al). The melting temperatures of LiXH4 (X = B, Al) are used to predict the temperatures of hydrogen decomposition. The obtained melting temperature of α-LiBH4 is higher than that of β-LiAlH4. Thus, LiAlH4's decomposition temperature at which hydrogen is emitted from a fuel cell is anticipated to be lower than that of the LiBH4 compound. The bonding behavior of α-LiBH4 is more directed than that of β-LiAlH4. All the LiXH4 (X = B, Al) are found to be ductile except α-LiAlH4 which is found to be fragile. LiBH4 experiences greater volume change during uniaxial deformation than LiAlH4 and both are centrally strong solids. Our PBE calculations yield the linear compressibility and Young's modulus orientation dependent. The orthorhombic LiBH4 and tetragonal LiAlH4 are isotropic in bulk and anisotropic in Young's modulus.
•The computed stress–strain relationships effectively yield the elastic constants of a single crystal.•The compressibility modulus of the LiBH4 compound is greater than that of the LiAlH4.•The orthorhombic LiBH4 and tetragonal LiAlH4 are isotropic in bulk and anisotropic in Young's modulus.•These materials could be useful for storage of hydrogen application.
Bis(8-hydroxyquinoline) zinc (
ZnQ
2
) and tris-(8-hydroxyquinoline) aluminum (
AlQ
3
) organometallics have been synthesized and incorporated into poly(methyl methacrylate) (PMMA) films for ...potential use in green-emitting OLED applications. The
ZnQ
2
and
AlQ
3
organometallics were prepared using an acid–base co-precipitation technique. Fourier-transform infrared spectroscopy and x-ray diffraction patterns were utilized to confirm the formation of
ZnQ
2
,
AlQ
3
, and ZnQ
2
–AlQ
3
compounds. UV–Vis spectroscopy analysis revealed that
PMMA
/
ZnQ
2
,
PMMA
/
AlQ
3
, and PMMA/(ZnQ
2
–AlQ
3
) composite solutions exhibited two primary transition bands in the range of approximately 330 nm and 380 nm, corresponding to the
π
–
π
*
and
n
–
π
*
transition bands, respectively. The average electrical conductivity of the
PMMA
/
ZnQ
2
composite film was measured as 1.19
μ
S/cm, while the
PMMA
/
AlQ
3
composite film displayed a conductivity of 1.56
μ
S/cm, indicating that the intra-ligand charge-transfer of electrons in
AlQ
3
was higher than that in Znq_2. Additionally, photoluminescence (PL) emission peaks for the
PMMA
/
ZnQ
2
,
PMMA
/
AlQ
3
, and PMMA/(ZnQ
2
–AlQ
3
) composite solutions were observed at wavelengths of 522 nm, 505 nm, and 509 nm, respectively, confirming their potential suitability for use in green-emitting OLEDs.
•Ofloxacin antibiotics and silver nanoparticles (AgNPs) to create a synergistic antibiotic compound.•1HNMR chemical shifts with increasing AgNPs content confirms the intermolecular tethering ...primarily via fluorine atoms.•The most common coordination mode is bidentate, with one oxygen atom from the deprotonated carboxylic group.
The escalating demand for novel antibacterial agents has arisen due to the emergence of antibiotic-resistant strains among various pathogenic bacteria. This study investigates the molecular tethering of ofloxacin antibiotics and silver nanoparticles (AgNPs) to create a synergistic antibiotic compound known as ofloxacin−AgNPs. In solution, AgNPs form intramolecular bonds with the 9-fluorine atom and/or hydrogen in the 7-oxo-6-hydroxylic acid group of the ofloxacin molecule. Exploring the physicochemical and biomedical properties of ofloxacin−AgNPs, including viscosity, molecular dynamics, and molecular relaxations, is crucial for comprehending their efficacy as medical drugs. Furthermore, the ofloxacin−AgNPs system was subjected to 1H-NMR and 19F-NMR spectroscopic analyses, as well as an investigation of the spin-lattice relaxation time (T1). The T1 results indicate that the primary intramolecular bonding involves fluorine atoms, particularly those neighboring the proton and nitrogen atoms. Notably, the antimicrobial activity does not exhibit a linear correlation with the concentration of AgNPs, highlighting the substantial influence of physicochemical bonding on this activity.
