Molecular Dynamics of Steroidal Rotors Probed by Theoretical, Spectroscopic and Dielectric Methods

Our study focuses on molecular rotors with fast-moving rotators and their potential applications in the development of new amphidynamic crystals. Steroidal molecular rotors with a dipolar fluorine-substituted phenyl group as the rotator were synthesized and characterized. Three different rotors were investigated with varying numbers of fluorine atoms. A comprehensive analysis was performed using vibrational spectroscopy (Raman, FT-IR), electronic circular dichroism (ECD), and dielectric response to understand the behavior of the investigated model rotors. The results were supported by theoretical calculations using Density Functional Theory (DFT) methods. The angle-dependent polarized Raman spectra confirmed the crystallinity of the samples. Nearly frequency and temperature-independent permittivity suggest low-frequency librational motion of stators. An in-depth analysis of ECD spectra revealed high conformational flexibility in solution, resulting in low ECD effects, while in the solid-state with restricted rotation, significant ECD effects were observed. These findings shed light on the conformational behavior and potential applications of the studied steroidal molecular rotors.

Unfavorable effects of sodium-glucose cotransporter 2 (SGLT2) inhibitors on the skeletal system of nondiabetic rats

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a new class of antidiabetic drugs, acting by inhibiting the reabsorption of glucose in the kidneys. They turned out to improve cardiovascular and renal outcomes not only in patients with type 2 diabetes but also in nondiabetic patients. At present, they are more and more widely used in patients without diabetes. Since there were concerns that SGLT2 inhibitors may increase fracture risk in diabetes, the aim of the study was to examine the effect of dapagliflozin and canagliflozin on the musculoskeletal system of nondiabetic, healthy rats. The experiments were carried out on mature female rats, divided into the control rats and rats treated with dapagliflozin (1.4 mg/kg p.o.) or canagliflozin (4.2 mg/kg p.o.) for 4 weeks. Serum bone turnover markers, skeletal muscle strength and mass, bone mass, density, histomorphometric parameters and mechanical properties were determined. Administration of the drugs did not affect the skeletal muscle mass and strength. There was no effect on serum bone turnover markers, and bone mass and composition. However, administration of both drugs resulted in disorders of cancellous bone microarchitecture and worsening of bone mechanical properties. In conclusion, both SGLT2 inhibitors unfavorably affected the skeletal system of healthy rats.

Użycie Księgi Koheleta w Ewangelii wg św. Łukasza

W Łk można wskazać osiem fragmentów, w których widoczne są odniesienia do Koh (2,40.52; 8,5–8a; 8,25.35; 11,42; 12,2–3; 12,19; 12,20; 12,25). Najczęściej w passusach trzeciej ewangelii można widzieć echo słów zapisanych przez Eklezjastesa. Nie jest to jednak jedyny rodzaj związku zachodzący pomiędzy tymi tekstami. W Koh 1,16 bohater przedstawiony jako Salomon może być typem Jezusa pokazanego w Łk 2,40.52. W Łk 12,19 można widzieć natomiast prawdopodobną aluzję do Koh 8,15. Użycie typologii, aluzji i ech w zaprezentowanych powyżej fragmentach wpisuje się w badanie zależności intertekstualnych pomiędzy tekstami. Autor trzeciej ewangelii poprzez użycie Koh dokonuje jego reinterpretacji.

Steroidal Molecular Rotors with 1,4-Diethynylphenylene Rotators: Experimental and Theoretical Investigations Toward Seeking Efficient Properties

Properly designed molecular rotors with sizable stators and a fast-moving rotator could provide efficient building blocks for amphidynamic crystals. Herein, we report the synthesis of steroidal compounds 1, 2, and 3 and their deuterated analogues 1D, 2D, and 3D envisioned to work as molecular rotors. The obtained compounds were characterized by attenuated total reflection-infrared, Raman, and circular dichroism (CD) spectroscopy measurements. The interpretation of spectra was supported by theoretical calculations using density functional theory methods. The analysis of the most characteristic bands confirmed different molecular dynamics of the rotors investigated. Angle-dependent polarized Raman spectra showed the crystallinity of some samples. Electronic CD (ECD) spectra of compounds 1–3 and their relevant deuterated analogues 1D–3D are identical. The increase of the band intensity with lowering the temperature shows that the equilibrium is shifted to the thermodynamically most stable conformer. ECD spectra simulated at the TDFFT level of theory for compound 3 were compared with experimental results. It was proved that conformer 3a, with a torsion angle of +50°, exhibits the best agreement with the experimental results. Simulated vibrational CD and IR spectra for conformer 3a and its deuterated analogue 3Da also display good agreement with experimental results. In light of our comprehensive investigations, we evidenced that steroidal compounds 1, 2, and 3 can work as molecular rotors.

Vibrational spectroscopic characterization of cyclic and acyclic molecular rotors with 1,4-diethynylphenylene-d4 rotators

The synthesis and characterization of acyclic and cyclic molecular rotors with 1,4-diethynylphenylene-d₄ rotators are described. The ATR-FTIR and Raman spectra of acyclic rotor 3 and cyclic rotor 5E were measured and interpreted. A feature of ATR-FTIR spectrum of rotor 5E is a strong two-component band around 1730cm^-1 attributed to symmetric and asymmetric stretching vibration of the carbonyl group, while this is not observed in rotor 3. Raman investigation in the wide temperature range of 350 - 10K was carried out. The splitting of Raman bands in the region of stretching vibration of CC double and triple bonds at 170 and 260K for rotor 5E is observed. The splitting of bands is due to changes in molecular structure.

Thermal stability of the elastomeric anti-trauma pad

The elastomeric anti-trauma pad (EA-TP) based on shear thickening fluid (STF) has been developed. Dynamic oscillatory shear experiment was conducted at constant strain amplitude of 5%. STF composed of 25% of volume fraction of 7 nm Fumed Silica, dispersed in polypropylene glycol with molar mass 400 gmol−1 shows elastic properties in entire investigated range of the frequency. Ballistic tests of EA-TP with 7.62 mm × 39 mm PS bullets were performed according to the PN-V-87000:2011 standard. The studies revealed about 60% reduction of the average backface signature depth (BSD) for the EA-TP, when compared to the nowadays commonly used soft insert. The ATR-FTIR analysis confirmed slight impact of the elevated temperature and air (oxygen) on the chemical degradation of the EA-TP surface. The UV-VIS spectroscopy has allowed to notice colour deviation of the aged samples towards green and yellow, as well as lack of dye resistance to accelerated aging process. Thermographic analysis has shown no visible changes of the EA-TP surface and sub-surface during accelerated aging process. The aforementioned small changes on the surface of EA-TP did not affect the ballistic properties of composite armour. EA-TP insert maintains ballistic properties after accelerated aging process which was simulating the period of 6 years according to ASTM F1980 – 07:2002 standard.

Coatings manufactured using magnetron sputtering technology to protect against infrared radiation for use in firefighter helmets

The aim of this study was to test the usefulness of magnetron sputtering technology to produce coatings on selected elements of a firefighter’s helmet to protect against infrared radiation (PN-EN 171 standard). The scope of research includes testing the deposition produced via magnetron sputtering of metallic and ceramic coatings on plastics, which are used to manufacture the components comprising the personal protection equipment used by firefighters. The UV-VIS, NIR used to research the permeation coefficients and reflections for light and infrared light and the emission spectrometry with ICP-AES used for the quantitative analysis of elements in metallic and ceramic coatings. Microstructural and micro-analytical testing of the coatings were performed using scanning electron microscopy (SEM). Measurements of the chemical compositions were conducted using energy-dispersive X-ray spectroscopy (EDS). The hardnesss of the coatings were tested using a indentation method, and the coating thicknesses were tested using a ellipsometry method.

[Early age at menarche - relationship with socioeconomic status and selected factors connected with health status]

INTRODUCTION

Current research from around the world indicates a trend toward younger ages at the first menstruation. At the same time more and more studies point out the negative consequences of early puberty. Early age at menarche is significantly correlated with the risk of metabolic syndrome, breast cancer and female reproductive system cancer, as well as illnesses such asthma and bulimia. The aim of the study was to examine the relationship between age at menarche and socioeconomic status and selected factors connected with biological conditions.

MATERIAL AND METHODS

The data were obtained from 671 female university students. Height, weight, waist and hip circumference were measured, and BMI, WHR, WHtR were calculated. A questionnaire form was used to assess the age at menarche, biological conditions and socioeconomic status of the surveyed students.

RESULTS

There were no significant differences in the number of the early, average and late maturing students between the socioeconomic groups. The early maturing girls were characterized by higher values of waist circumference, BMI, WHR and WHtR. The prevalence of obesity and abdominal obesity was highest among the early maturing girls. The analysis did not show statistically significant relationships between age at menarche and selected factors connected with biological conditions.

CONCLUSION

Early maturation increases the risk of obesity and central adiposity distribution.

Muscle mitochondrial density after exhaustive exercise in dogs: prolonged restricted activity and retraining

The effect of exhaustive treadmill exercise on mitochondrial density (MD) and ultrastructural changes in quadriceps femoris muscle was studied in 7 normal, healthy, male mongrel dogs (2-4 years, 15-20 kg) before and after restricted activity (RA) (2 months for 5 dogs, 5 months for 2 dogs), and following a subsequent 2-month exercise retraining period (2-months group). Mean (+/- S.E.) time to exhaustion in the 2-month group decreased from 177 +/- 11 min before to 90 +/- 16 min (delta = -49%, p < 0.05) after RA; retraining increased tolerance to 219 +/- 36 min (delta = +24%, p < 0.05) above the pre-RA and 143% (p < 0.05) above the post-RA time. Post-RA exhaustion time in the 5-months group was 25 and 45 min (35 +/- 10 min). Muscle samples taken after RA showed abnormalities indicative of degeneration, which were reversed by retraining. Resting MD decreased (p < 0.05) from a control level of 27.8% to 14.7% (2 months) and 16.3% (5 months), and was restored to 27.1% (NS) after retraining. Exhaustive exercise caused an increase in MD under control conditions and after RA, but not following retraining. Disruption of mitochondria after exercise was evident after 5-months confinement. Factors causing mitochondrial changes and eventually their disruption during exercise after restricted activity are not related as much to the state of fatigue as to the pre-exercise quality of the muscle modified by disease or training.

Craviten effect on the metabolism of stored platelets

Craviten effect on platelets suspended in their own plasma was investigated by two methods of incubation with the drug: the fresh platelets were incubated for 18 h at 4 degrees C with Craviten added to plasma and platelets stored for 18 h at 4 degrees C without Craviten were incubated with Craviten at 37 degrees C for 1 h. For evaluation of the metabolic activity and function of the platelets, the levels of high-energy compounds ATP and ADP, the activity of hexokinase and pyruvate kinase and the amount of adenyl nucleotides released by the platelets after thrombin addition were measured, and the spontaneous aggregation of platelets and c-AMP were determined. The experiments demonstrated that Craviten prevented the fall of ATP level of the stored platelets, raised the activity of hexokinase and pyruvate kinase in the platelets, increased the amount of nucleotides released by the platelets in the release reaction. Craviten inhibited also increased spontaneous aggregation of stored platelets and raised c-AMP level.

[Effect of cytostatic agents on the metabolism and ultrastructure of blood platelets in man]

The effect of cytostatic drugs used in the treatment of haemopoietic system diseases: cerubidin, hydroxyurea. cytosine arabinoside and their combinations on the platelet count, platelet ultrastructure, metabolic activity and participation in the processes of haemostasis was investigated. The experiments were done using two concentrations of the drugs: clinical corresponding to the maximal single dose and a fivefold as high concentration, It was found that the investigated cytostatic agents and their cominations in the first concentration had no effect of the platelet count, level of free nucleotides, activity of glucose-6-phosphate dehydrogenase and lactic dehydrogenase, and on the reaction of adenine nucleotides release from the platelets induced with thrombin. Using the higher concentration of the drugs it was observed that cerubidin and the combination of cytostatic agents tested changed the shape and ultrastructure of the platelets.