A potential toxicological risk assessment of heavy metals and pesticides in irrigated rice cultivars near industrial areas of Dhaka, Bangladesh.

Rice intake represents a significant pathway through which humans accumulate heavy metals. This study presents a comprehensive analysis of heavy metal and pesticide contamination in rice cultivars irrigated with industrial wastewater near Dhaka, Bangladesh, a region heavily influenced by industrial activities. This study employed a unique methodology that not only quantified the concentrations of heavy metals and pesticide residues in rice grains but also extended to evaluating the physicochemical properties of rice stems, husks, soil, and irrigation water. The findings revealed alarmingly high levels of heavy metals such as lead, cadmium, chromium, nickel, and mercury in the soil and irrigation water, with concentrations in some cases exceeding the World Health Organization safety thresholds by 2 to 15 times. Notably, the rice grains also exhibited significant contamination, including substantial amounts of diazinon and fenitrothion pesticides, exceeding the established safety limits. The study employed hazard quotients (HQs) and cancer risk (CR) assessments to evaluate the potential health risks associated with the consumption of contaminated rice. The results indicated HQ values were greater than 1 for rice grains across the sampled fields, suggesting a considerable non-carcinogenic health risk, particularly from lead exposure, which was found at levels twice the standard limit in all the sampling fields. Moreover, the CR values for As, Pb, Cd, Co, and Mn highlighted a significant carcinogenic risk in several instances.

Bio-Inspired Nanomaterials for Micro/Nanodevices: A New Era in Biomedical Applications.

Exploring bio-inspired nanomaterials (BINMs) and incorporating them into micro/nanodevices represent a significant development in biomedical applications. Nanomaterials, engineered to imitate biological structures and processes, exhibit distinctive attributes such as exceptional biocompatibility, multifunctionality, and unparalleled versatility. The utilization of BINMs demonstrates significant potential in diverse domains of biomedical micro/nanodevices, encompassing biosensors, targeted drug delivery systems, and advanced tissue engineering constructs. This article thoroughly examines the development and distinctive attributes of various BINMs, including those originating from proteins, DNA, and biomimetic polymers. Significant attention is directed toward incorporating these entities into micro/nanodevices and the subsequent biomedical ramifications that arise. This review explores biomimicry's structure-function correlations. Synthesis mosaics include bioprocesses, biomolecules, and natural structures. These nanomaterials' interfaces use biomimetic functionalization and geometric adaptations, transforming drug delivery, nanobiosensing, bio-inspired organ-on-chip systems, cancer-on-chip models, wound healing dressing mats, and antimicrobial surfaces. It provides an in-depth analysis of the existing challenges and proposes prospective strategies to improve the efficiency, performance, and reliability of these devices. Furthermore, this study offers a forward-thinking viewpoint highlighting potential avenues for future exploration and advancement. The objective is to effectively utilize and maximize the application of BINMs in the progression of biomedical micro/nanodevices, thereby propelling this rapidly developing field toward its promising future.

Effect of sizes of vinyl modified narrow-dispersed silica cross-linker on the mechanical properties of acrylamide based hydrogel.

Polymeric hydrogel with the incorporation of nano to submicro-meter sized materials forms an exhilarating new generation of composite hydrogels. Most of the applications of hydrogels are in aqueous environments in which they swell to a very high degree. This emanates from low density of the polymer chains, making them highly inferior in terms of physical strength and their prospective applications. In order to address the weak mechanical properties, hydrogels have successfully prepared with high tensile strength and toughness by reinforcing the acrylamide (AAm) network with 3-methacryloxypropyltrimethoxysilane (MPTS) modified silica particles (MSiO2) as chemical cross-linker. The MSiO2 cross-linkers are prepared from narrow-dispersed silica particles (SiO2) of 100 nm, 200 nm, and 300 nm diameters to investigate the effect of cross-linker sizes on the mechanical strengths of hydrogels. The presence of MSiO2 remarkably increases the stretching ability and toughness of hydrogels compared to conventional hydrogels. The tensile strength, toughness, and Young's modulus of the hydrogel decrease from 30 to 11 kPa, 409 to 231 kJ/m3, and 0.16 to 0.11 kPa, respectively, while the SiO2 particle size increase from 100 to 300 nm and the concentration of AAm and MSiO2 (%) are kept constant. The compressive strength and toughness of the hydrogel decrease from 34 to 18 kPa and 6 to 4 kJ/m3, respectively, but the Young's modulus increases from 0.11 to 0.19 kPa. This work is excellent proof of regulating mechanical strength of hydrogel by adjusting the particle size of MSiO2 cross-linkers.

Green Polymer Nanocomposites in Automotive and Packaging Industries.

Green polymer nanocomposites referred to as completely biodegradable, renewable, environmentally friendly, and benign materials, have received a surge of attention to promote sustainable development. Polymer nanocomposites, where nanomaterials are used for reinforcement, possess a large interfacial area per volume, and the intervals between the filler nanoparticles and polymer matrix are significantly short. Molecular interactions between the filler particles and the matrix, therefore, provide polymer nanocomposites with novel characteristics that ordinary polymers or conventional macrocomposites do not possess. However, nanoparticles, nanotubes, nanofilms, nanofibers, nanoflakes, etc., in the form of nanocomposites may cause serious health hazards and pollute the environment severely. While the number of review articles on fundamental and applied research work of polymer nanocomposites is noteworthy, this review focuses more in depth on the applications of safe and green polymer nanocomposites in the automotive and packaging industries. The particular focus has been to examine and investigate in detail the initial and contemporaneous trends, status, and perspectives of green and safe polymer nanocomposites in the automotive and packaging industries. Background characteristics, strengths, weaknesses, potentiality, prospects, and opportunities of green polymer nanocomposites suitable for automotive and packaging industries have been addressed. The ultimate goal is to have a profound understanding of the structure-property relationship of green polymer nanocomposites to overcome existing limitations for automotive and packaging applications.

Rapid diagnosis of COVID-19 via nano-biosensor-implemented biomedical utilization: a systematic review.

The novel human coronavirus pandemic is one of the most significant occurrences in human civilization. The rapid proliferation and mutation of Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2) have created an exceedingly challenging situation throughout the world's healthcare systems ranging from underdeveloped countries to super-developed countries. The disease is generally recognized as coronavirus disease 2019 (COVID-19), and it is caused by a new human CoV, which has put mankind in jeopardy. COVID-19 is death-dealing and affects people of all ages, including the elderly and middle-aged people, children, infants, persons with co-morbidities, and immunocompromised patients. Moreover, multiple SARS-CoV-2 variants have evolved as a result of genetic alteration. Some variants cause severe symptoms in patients, while others cause an unusually high infection rate, and yet others cause extremely severe symptoms as well as a high infection rate. Contrasting with a previous epidemic, COVID-19 is more contagious since the spike protein of SARS-CoV-2 demonstrates profuse affection to angiotensin-converting enzyme II (ACE2) that is copiously expressed on the surface of human lung cells. Since the estimation and tracking of viral loads are essential for determining the infection stage and recovery duration, a quick, accurate, easy, cheap, and versatile diagnostic tool is critical for managing COVID-19, as well as for outbreak control. Currently, Reverse Transcription Polymerase Chain Reaction (RT-PCR) testing is the most often utilized approach for COVID-19 diagnosis, while Computed Tomography (CT) scans of the chest are used to assess the disease's stages. However, the RT-PCR method is non-portable, tedious, and laborious, and the latter is not capable of detecting the preliminary stage of infection. In these circumstances, nano-biosensors can play an important role to deliver point-of-care diagnosis for a variety of disorders including a wide variety of viral infections rapidly, economically, precisely, and accurately. New technologies are being developed to overcome the drawbacks of the current methods. Nano-biosensors comprise bioreceptors with electrochemical, optical, or FET-based transduction for the specific detection of biomarkers. Different types of organic-inorganic nanomaterials have been incorporated for designing, fabricating, and improving the performance and analytical ability of sensors by increasing sensitivity, adsorption, and biocompatibility. The particular focus of this review is to carry out a systematic study of the status and perspectives of synthetic routes for nano-biosensors, including their background, composition, fabrication processes, and prospective applications in the diagnosis of COVID-19.

Structurally coloured secondary particles composed of black and white colloidal particles.

This study investigated the colourful secondary particles formed by controlling the aggregation states of colloidal silica particles and the enhancement of the structural colouration of the secondary particles caused by adding black particles. We obtained glossy, partially structurally coloured secondary particles in the absence of NaCl, but matte, whitish secondary particles were obtained in the presence of NaCl. When a small amount of carbon black was incorporated into both types of secondary particles, the incoherent multiple scattering of light from the amorphous region was considerably reduced. However, the peak intensities in the reflection spectra, caused by Bragg reflection and by coherent single wavelength scattering, were only slightly decreased. Consequently, a brighter structural colour of these secondary particles was observed with the naked eye. Furthermore, when magnetite was added as a black particle, the coloured secondary particles could be moved and collected by applying an external magnetic field.

Structural colored gels for tunable soft photonic crystals.

A periodically ordered interconnecting porous structure can be embodied in chemical gels by using closest-packed colloidal crystals as templates. The interconnecting porosity not only provides a quick response but also endows the porous gels with structural color arising from coherent Bragg optical diffraction. The structural colors revealed by porous gels can be regulated by several techniques, and thus, it is feasible to obtain desirable, smart, soft materials. A well-known thermosensitive monomer, N-isopropylacrylamide (NIPA), and other minor monomers were used to fabricate various structural colored gels. The selection of minor monomers depended on the targeted properties. This review focuses on the synthesis of templates, structural colored porous gels, and the applications of structural colored gel as smart soft materials for tunable photonic crystals.