Quality and Quantity Assessment of the Water Repellent Properties of Functional Clothing Materials after Washing.

The aim of the research was to evaluate the changes in the surface properties of five functional clothing materials with water-repellent finishes (including PFC-free finish) after 1, 5, and 10 washes with three detergents. A new approach to the interpretation of the water-repellent properties of textile materials is presented, based on two techniques, i.e., the spray test method and contact angle measurements. The results showed that washing materials with hydrophobic finishes can cause significant changes in their properties, which are mainly dependent on the composition and structure of the material, as well as the type of hydrophobic finish. The PFC-free finish is the least resistant to washing. For all materials with PFC finishes, the water repellency depends on the fluorine content on the surface and fabric topography. It was also found that increasing washing frequency resulted in a gradual decrease in water repellency. The loss of water repellency below an acceptable level (Grade 3) occurred after the fifth washing for all materials. Significant differences in the interpretation of the results of the spray test and contact angle measurements were observed. Using these methods separately provides information on the changes in the surface properties of the tested materials; however, their parallel application allows for obtaining complementary data, which is important for the proper interpretation of results.

The Effect of Dry Carbon Dioxide Bathing on Peripheral Blood Circulation Measured by Thermal Imaging among Patients with Risk Factors of PAD.

Peripheral artery disease (PAD) is becoming a serious health problem of present times. It appears crucial to explore therapies that might help to restore blood flow or increase tissue oxygenation. The most effective methods of detecting early-stage changes in blood circulation in the extremities need to be identified. The aim of this study was to identify the effect of carbon dioxide (CO2) bathing on peripheral blood circulation measured by thermal imaging among patients with risk factors of PAD and ankle-brachial index (ABI) in the normal range or ABI indicating some or moderate arterial disease (ABI > 0.5). The correlation between surface temperature change and PAD-relevant characteristics was also examined. Forty-six patients who were over 65 years old who had a minimum of two additional PAD risk factors were recruited. A series of ten dry CO2 baths was performed. Thermal images were taken before and after the intervention. The CO2 therapy caused a significant change in the body surface temperature of many body areas. Numerous moderate correlations between temperature change and health-related characteristics were identified. Therefore, patients with PAD risk factors could benefit from CO2 therapy. Improvements in blood flow change the body surface temperature, and these changes could be successfully detected by thermal imaging.

Influence of the Elastoplastic Strain on Fatigue Durability Determined with the Use of the Spectral Method.

The paper presents experimental static and fatigue tests results under random loading conditions for the bending of 0H18N9 steel. The experimental results were used in performing calculations, according to the theoretical assumptions of the spectral method of fatigue life assessment, including elastoplastic deformations. The presented solution extends the use of the spectral method for material fatigue life assessment, in terms of loading conditions, above Hooke's law theorem. The work includes computational verification of the proposal to extend the applicability of the spectral method of determining fatigue life for the range of elastoplastic deformations. One of the aims of the proposed modification was to supplement the stress amplitudes used to calculate the probability density function of the power spectral density of the signal with correction, due to the plastic deformation and its use for notched elements. The authors have tested the method using four of the most popular probability density functions used in commercial software. The obtained results of comparisons between the experimental and calculation results show that the proposed algorithm, tested using the Dirlik, Benasciutti-Tovo, Lalanne, and Zhao-Baker models, does not overestimate fatigue life, which means that the calculations are on the safe side. The obtained results prove that the elastoplastic deformations can be applied within the frequency domain for fatigue life calculations.

Behavior of Caenorhabditis elegans in a nicotine gradient modulated by food.

Nicotine decreases food intake, and smokers often report that they smoke to control their weight. To see whether similar phenomena could be observed in the model organism Caenorhabditis elegans, we challenged drug-naïve nematodes with a chronic low (0.01 mM) and high (1 mM) nicotine concentration for 55 h (from hatching to adulthood). After that, we recorded changes in their behavior in a nicotine gradient, where they could choose a desired nicotine concentration. By using a combination of behavioral and morphometric methods, we found that both nicotine and food modulate worm behavior. In the presence of food (E. coli OP50) the nematodes adapted to the low nicotine concentration, when placed in the gradient, chose a similar nicotine concentration like C. elegans adapted to the high nicotine concentration. However, in the absence of food, the nematodes adapted to the low nicotine concentration, when placed in the gradient of this alkaloid, chose a similar nicotine concentration like naïve worms. The nematodes growing up in the presence of high concentrations of nicotine had a statistically smaller body size, compared to the control condition, and the presence of food did not cause any enhanced slowing movement. These results provide a platform for more detailed molecular and cellular studies of nicotine addiction and food intake in this model organism.

Concentration- and time-dependent behavioral changes in Caenorhabditis elegans after exposure to nicotine.

Nicotine induces profound behavioral responses in the model organism Caenorhabditis elegans. We tested the effect of a broad range of concentrations of nicotine (from 0.001 mM to 30 mM in nematode growth medium) on C. elegans locomotor behavior. We also followed the time-course influence on the sensitivity of C. elegans to nicotine (from 0 min to 300 min). A low concentration (0.001 mM) of this alkaloid causes a reduction of the speed of movement. By contrast, moderate concentrations (0.01 and 0.1 mM) induced acceleration of the mean speed of locomotion of C. elegans. High doses of nicotine (above 1 mM) induced slowing down of the movements and, finally, paralysis. Time-dependent analysis revealed that the stimulating effect of nicotine abolished the slowing down of C. elegans in control experiments after 30 min in the presence of 0.001, 0.1 and 10 mM nicotine. In the presence of 0.1 mM nicotine, the stimulation phase lasted up to 70 min. The evidence indicates that nicotine can have dual effects on the speed of locomotion, which is dependent on differences in its dosage and treatment time.