ABSTRACT
Herein, refined LaxCa0.89-xSr0.11MnO3 (LCSMO, x = 0.65, 0.68, 0.71 and 0.74) films were prepared through the sol-gel spin-coating. The influence of La3+ content on the structural properties of LCSMO films was investigated by X-ray diffraction and Atomic force microscope, demonstrating that LCSMO films can grow well on SrTiO3 (00l) substrate. Besides, X-ray photoemission spectroscopy verified the double exchange (DE) effect was weakened with La3+ dopant. The La3+ doping and interconnected grains boundaries (GBs) led to the weakening DE effect and GBs scattering, respectively. Due to superior GBs connectivity, the resistivity of LCSMO films was less than 7.1 x 10(-4) Omega.cm at low temperature of 100 K. Importantly, it is an effective control method to keep the temperature (T-k) corresponding to temperature coefficient of resistivity (TCR) at room temperature with Sr2+ content as constant in LCSMO films. At x = 0.71, the peak TCR value was found to be 8.84%/K and corresponding T-k was 283.15 K. These results are beneficial for advanced application of uncooling infrared bolometer.
ABSTRACT
Real-time monitoring of changes in skin temperature with smart thermochromic fabrics that act as sensors is extremely important in the early diagnosis of febrile diseases such as the COVID-19 epidemic that endanger public health. In this context, the study aims to detect fever, which is the immune response of the body, as a symptom in the diagnosis of various diseases and to prepare a thermochromic functional fabric by coating method to reduce the risk of contamination. For this purpose, a composition containing green pigment and zinc acetate dihydrate as the starting material was prepared using the sol-gel method. The prepared composition was applied to calico and alpaca fabric, and it was provided to show transformation at 37.5 °C with the effect of the pigment, which had a color change feature at 33 °C. The samples were analyzed using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) characterization methods. The results showed that it was possible to change the active conversion temperature of the pigment from 33 °C to 37.5 °C, depending on the composition. The use of the compositions developed in this study in alpaca fabric coating provides an area of use as an indicator if the human body temperature reaches 37.5 °C, which is considered the concept of fever.
ABSTRACT
A fast procedure obtained by the combination of fabric phase extraction (FPSE) with high performance liquid chromatography (HPLC) has been developed and validated for the quantification of favipiravir (FVP) in human plasma and breast milk. A sol-gel polycaprolactone-block-polydimethylsiloxane-block-polycaprolactone (sol-gel PCAP-PDMS-PCAP) coated on 100% cellose cotton fabric was selected as the most efficient membrane for FPSE in human plasma and breast milk samples. HPLC-UV analysis were performed using a RP C18 column under isocratic conditions. Under these optimezed settings, the overall chromatographic analysis time was limited to only 5 min without encountering any observable matrix interferences. Following the method validation procedure, the herein assay shows a linear calibration curve over the range of 0.2–50 µg/mL and 0.5–25 µg/mL for plasma and breast milk, respectively. The method sensitivities in terms of limit of detection (LOD) and limit of quantification (LOQ), validated in both the matrices, have been found to be 0.06 and 0.2 µg/mL for plasma and 0.15 and 0.5 µg/mL for milk, respectively. Intraday and interday precision and trueness, accordingly to the International Guidelines, were validated and were below 3.61% for both the matrices. The herein method was further tested on real samples in order to highlight the applicability and the advantage for therapeutic drug monitoring (TDM) applications. To the best of our knowledge, this is the first validated FPSE-HPLC-UV method in human plasma and breast milk for TDM purposes applied on real samples. The validated method provides fast, simple, cost reduced, and sensitive assay for the direct quantification of favipiravir in real biological matrices, also appliyng a well-known rugged and cheap instrument configuration. © 2022 Elsevier B.V.
ABSTRACT
Layered double hydroxide nanomaterials (LDH NMs) have been dragging the researchers' attention toward biomedical applications owing to their physiochemical properties, biocompatibility, environmental sensitivity and good cellular uptake mechanisms. Various synthetic methods have been presented in brief. This paper draws attention toward the modification and functionalization of LDH nanostructures for biomedical applications in targeted and controlled drug release, anticancer, bioimaging, bone therapy and regeneration, gene delivery, ophthalmic and antitumor activities. Further, it explains the properties of conjugated LDH NMs which put forward their possibilities to be used in synthesizing the most demanding vaccine for COVID-19 pandemic. Current scenario, challenges and future perspective of LDH NMs have also been discussed.
ABSTRACT
The rediscovery of the medical uses of silver provides another noticeable example, this time at the interface of chemistry and medicine, of the real (and nonlinear) progress of scientific research. Several new silver-based antimicrobial products have thus been commercialized in the last two decades. Next-generation antibacterials and antivirals of broad scope, low toxicity and affordable cost, we argue in this study, will be based on microencapsulated Ag nanoparticles.