Prediction of long‐term mechanical properties of PVDF/BaTiO3 nanocomposite

Low elastic modulus of polyvinylidene fluoride (PVDF) is a major drawback that can be compensated by adding nanoparticles. This work reports the long‐term mechanical behavior of PVDF nanocomposite containing BaTiO₃ nanoparticle that is evaluated by creep test. The nanocomposite morphology was characterized by scanning and transmission electron microscopy techniques. The dynamic mechanical analysis (DMA) was employed to study the viscoelastic behavior of nanocomposite in a wide range of temperatures and frequencies. According to the creep tests, nanocomposite reduced the rate of the creep compliance at different temperatures. Moreover, the creep compliance for the nanocomposite sample decreased slightly in comparison with neat PVDF. Comparing the Burger's model and experimental results, the elastic and viscous parameters revealed the exactly opposite behavior with increasing temperature. The effect of frequencies on storage moduli of samples was investigated based on time–temperature superposition (TTS) method. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40596.     

Survey of the natural occurrence of zearalenone in maize from northern Iran by thin-layer chromatography densitometry

During September 2000, forty samples of preharvest maize from the province of Mazandaran, north Iran, were randomly collected. Samples were analysed for zearalenone (ZEA) by a thin-layer chromatograpy (TLC) method (AOAC Official Method). ZEA was extracted with chloroform, purified through a chromatographic column containing silica gel, separated on a TLC plate and quantified by densitometry. The analytical method was validated and was adequately reliable and sensitive. The mean recovery rate of ZEA from spiked samples was 92%. The absolute amount of ZEA standard detectable on a TLC plate was 20 ng, giving a limit of detection (LOD) of 100 ng g^-1. In some samples, it was shown that aflatoxins interfere with ZEA. Therefore, to remove this interference, the TLC mobile phase was changed. Data revealed that three of 40 (7.5%) maize samples contained ZEA in the range 100-212 ng g^-1, with a mean of 141 ±51 ng g^-1. This study, which is the first report of ZEA occurrence in Iranian maize, showed that the ZEA level in maize of Mazandaran province was lower than maximum limit for this mycotoxin in Iran.     

Effect of external magnetic field on the deposition of BaFe12O19

The contribution of an external magnetic field on the deposition of BaFe₁₂O₁₉ thin film was investigated. For this purpose, two (one with applied field and another without field) thin films of BaFe₁₂O₁₉ were deposited on the C-plane oriented sapphire (Al₂O₃) substrate employing pulsed laser deposition technique. Crystallographic orientation and texture were determined using an X-ray diffractometer. The magnetic parameters were deduced from a vibrating sample magnetometer (VSM). A spectrometer was used to study the optical properties of the films. The structural results reveal the film to be predominantly single phase with C-plane orientation in both the cases. The film deposited with field, however, has bigger grain size and more perfection in crystallinity. The magnetic parameters show that the film deposited with the field has more remanence magnetization and higher coercive field. The diffuse reflectance of the film deposited with field is much higher due to the increased grain size and roughness.     

Mouse Liver Compensates Loss of Sgpl1 by Secretion of Sphingolipids into Blood and Bile

Sphingosine 1 phosphate (S1P) lyase (Sgpl1) catalyses the irreversible cleavage of S1P and thereby the last step of sphingolipid degradation. Loss of Sgpl1 in humans and mice leads to accumulation of sphingolipids and multiple organ injuries. Here, we addressed the role of hepatocyte Sgpl1 for regulation of sphingolipid homoeostasis by generating mice with hepatocyte-specific deletion of Sgpl1 (Sgpl1^HepKO mice). Sgpl1^HepKO mice had normal body weight, liver weight, liver structure and liver enzymes both at the age of 8 weeks and 8 months. S1P, sphingosine and ceramides, but not glucosylceramides or sphingomyelin, were elevated by ~1.5–2-fold in liver, and this phenotype did not progress with age. Several ceramides were elevated in plasma, while plasma S1P was normal. Interestingly, S1P and glucosylceramides, but not ceramides, were elevated in bile of Sgpl1^HepKO mice. Furthermore, liver cholesterol was elevated, while LDL cholesterol decreased in 8-month-old mice. In agreement, the LDL receptor was upregulated, suggesting enhanced uptake of LDL cholesterol. Expression of peroxisome proliferator-activated receptor-γ, liver X receptor and fatty acid synthase was unaltered. These data show that mouse hepatocytes largely compensate the loss of Sgpl1 by secretion of accumulating sphingolipids in a specific manner into blood and bile, so that they can be excreted or degraded elsewhere.     

Plastic properties determination using virtual dynamic spherical indentation test and machine learning algorithms

Journal of Mechanical Science and Technology - Nondestructive experiments are widely employed for determining mechanical properties. In this work, a spherical impact test is virtually performed to...     

Terpenoids as Human Neutrophil Elastase (HNE) Inhibitors: A Comprehensive Review of Natural Anti-inflammatory Isoprenoids

Human neutrophil elastase (HNE) is an enzyme that plays a key role in the body‘s inflammatory response. It has been linked to several diseases such as chronic obstructive pulmonary disease (COPD), emphysema, and cystic fibrosis. As potential treatments for these diseases, HNE inhibitors are of great interest. Metabolites derived from plants, particularly terpenoids such as β-caryophyllene found in black pepper and other plants, and geraniol present in several essential oils, are recognized as significant sources of inhibitors for HNE. Because of their ability to inhibit HNE, terpenoids are considered promising candidates for developing novel therapies to treat inflammatory conditions such as COPD and emphysema. Furthermore, nature can serve as an excellent designer, and it may offer a safer drug candidate for inhibiting HNE production and activity in the future. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses were searched to get relevant and up-to-date literature on terpenoids as human neutrophil elastase inhibitors. This review focuses on the isolation, chemical diversity, and inhibition of human neutrophil elastase (HNE) of various terpenoids reported from natural sources up to 2022. A total of 251 compounds from various terpenoids classes have been reported. Further, it also provides a summary of HNE inhibitors and includes a thorough discussion on the structure-activity relationship.     

Effects of repeated frying on physicochemical characteristics,oxidative stress,and free radical scavenging potential of canola oil and ghee

The repeated use of cooking oils and ghee for the deep frying of food materials may affect their nutritional quality. The present study evaluated the effect of repeated frying on the physicochemical characteristics and antiradical potential of canola oil and ghee. The oil and ghee were used for frying of fish and chicken for 2, 4, 6, 8, and 10 frying cycles followed by the analysis of physicochemical, oxidative stress, and antiradical parameters. Regression analysis of the data showed a frying cycle-dependent significant linear increase in saponification (R² = 0.9507–0.9748), peroxide and acid values (R² = 0.956–0.9915), and malondialdehyde (MDA) production (R² = 0.9058–0.9557) of canola oil and ghee subjected to fish and chicken frying but exponential increase in saponification value (R² = 0.9778) and MDA production (R² = 0.7407) of canola oil and ghee used for fish frying. The increase in the number of frying cycles linearly decreased the iodine value (R² = 0.9781–0.9924), and 1, 1-diphenyl-2-picrylhydrazyl, hydroxyl, and 2, 2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging potential (R² = 0.9089–0.9979) of canola oil and ghee. Repeated frying in cooking oil and ghee increases oxidative stress and decreases their physicochemical and antioxidant qualities. Canola oil was comparatively more oxidative resistant than canola ghee. The regression equations derived from regression analysis will guide researchers to conduct similar types of univariate studies.     

Fragility assessment of an outrigger structure system based on energy method

Fragility curves development in structures has always been a focus of research interest among structural and earthquake engineers for which the maximum story drift is usually considered as the engineering demand parameter (EDP) known as the conventional approach. This paper aims at calculating the fragility curves of a tall building with outrigger braced system by considering the plastic strain energy as the EDP and compare it with the conventional approach. In addition, the effect of optimizing the position of outriggers on the exceedance probability of the structure under near- and far-fault seismic loadings is investigated in this paper. Fragility curves of this structure in four performance levels including immediate occupancy (IO), life safety (LS), collapse prevention (CP), and instability is extracted based on the conventional method. The fragility curves for the aforementioned performance levels are also extracted based on the plastic strain energy and compared with the conventional approach. The results have demonstrated that optimizing the location of the bracing system would lower the exceedance probability of the structure. Moreover, the exceedance probability of the investigated building with outrigger braced system under far-fault records in various levels is more than that of near-fault records. It is also concluded that the conventional approach would lead to more conservative results compared with the energy approach.     

Low-Cost Customized Color-Blind Contact Lenses using 3D Printed Molds

Prominence of color perception in our day-to-day routine is unequivocally pronounced, yet visual ramifications due to color vision deficiency (CVD) or color blindness impede carriers of this disorder from functioning normally. To circumvent this deficiency, patients opt for tinted glasses/contact lenses to complement their color distinction capabilities. Red-green color blindness, the most prevalent form of CVD, can be alleviated using such glasses/lenses that filter out problematic wavelengths (540–580 nm). Nonetheless, nearly all contact lenses established by companies and developed by researchers are tinted throughout their entire surface, causing patients discomfort and needless attention as people can easily note their deficiency. Ideally, the tint within the lens should only cover the eye's pupil as it is responsible for perceiving light. Hence herein, CVD contact lenses are fabricated by solely tinting the midportion of commercial lenses utilizing two additively manufactured molds with 4 and 8 mm-diameter holes to emulate the humans’ average pupil size. The tinted lenses filter light effectively at 530–590 nm with their transmission dip being at 558 nm. The contact lenses show excellent wettability and water retention capabilities along with demonstrating superior wavelength-filtering properties to most of the commercial and research-based CVD wearables.     

Zinc-based metal-organic frameworks: synthesis and recent progress in biomedical application

Journal of Inorganic and Organometallic Polymers and Materials - This review based on Zn-based MOF is summarized on new insights for targeted drug delivery of medicinal compounds and developed for...