Search

Heavy metals ions as metallic pollutants are a growing global issue due to their adverse effects on the aquatic ecosystem, and human health. Unfortunately, conventional detection methods such as atomic absorption spectrometry exhibit a relatively low limit of detection and hold numerous disadvantages, and therefore, the development of an efficient method for in-situ and real-time detection of heavy metal residues is of great importance. The aptamer-based sensors offer distinct advantages over antibodies and emerged as a robust sensing platform against various heavy metals due to their high sensitivity, ease of production, simple operations, excellent specificity, better stability, low immunogenicity, and cost-effectiveness. The nucleic acid aptamers in conjugation with nanomaterials can bind to the metal ions with good specificity/selectivity and can be used for on-site monitoring of metal ion residues. This review aimed to provide background information about nanomaterials-based aptasensor, recent advancements in aptamer conjunction on nanomaterials surface, the role of nanomaterials in improving signal transduction, recent progress of nanomaterials-based aptasening procedures (from 2010 to 2022), and future perspectives toward the practical applications of nanomaterials-based aptasensors against hazardous metal ions for food safety and environmental monitoring. [ABSTRACT FROM AUTHOR]

In view of ever-increasing environmental pollution, there is an immediate requirement to promote cheap, multiplexed, sensitive and fast biosensing systems to monitor these pollutants or contaminants. Aptamers have shown numerous advantages in being used as molecular recognition elements in various biosensing devices. Graphene and graphene-based materials/nanohybrids combined with several detection methods exhibit great potential owing to their exceptional optical, electronic and physicochemical properties which can be employed extensively to monitor environmental contaminants. For environmental monitoring applications, aptamers have been successfully combined with graphene-based nanohybrids to produce a wide range of innovative methodologies. Aptamers are immobilized at the surface of graphene based nanohybrids via covalent and non-covalent strategies. This review highlights the design, working principle, recent developmental advances and applications of graphene based nanohybrid aptasensors (GNH-Apts) (since January 2014 to September 2021) with a special emphasis on two major signal-transduction methods, i.e., optical and electrochemical for the monitoring of pesticides, heavy metals, bacteria, antibiotics, and organic compounds from different environmental samples (e.g., water, soil and related). Lastly, the challenges confronted by scientists and the possible future outlook have also been addressed. It is expected that high-performance graphene-based nanohybrid aptasensors would find broad applications in the field of environmental monitoring. [ABSTRACT FROM AUTHOR]

Approximate computing (AxC) provides the scope for achieving disproportionate gains in a system's power, performance, and area (PPA) metrics by leveraging an application's inherent error-resilient behavior (BEHAV). Trading computational accuracy for performance gains makes AxC an attractive proposition for implementing computationally complex AI/ML-based applications on resource-constrained embedded systems. The growing diversity of application domains using AI/ML has also led to the increasing usage of FPGA-based embedded systems. However, implementing AxC for FPGAs has primarily been limited to the post-processing of ASIC-optimized approximate operators (AxOs). This approach usually involves selecting from a set of AxOs that have been optimized for a gate-based implementation in an ASIC. While such an approach does allow leveraging existing knowledge of ASIC-based AxO design, it limits the scope for considering the challenges and opportunities associated with FPGA's LUT-based computation structures. Similarly, the few works considering the LUT-based computing for AxO design use generic optimization approaches that do not allow integrating problem-specific prior knowledge--empirical and/or statistical. To this end, we propose a novel tree search-based approach to AxO synthesis for FPGAs. Specifically, we present a design methodology using Monte Carlo Tree Search (MCTS)-based search tree traversal that allows the designer to integrate statistical data, such as correlation, into the AxOs optimization. With the proposed methods, we report improvements over standard MCTS algorithm-based results as well as improved hypervolume for both operator-level and application-specific DSE, compared to state-of-the-art design methodologies. [ABSTRACT FROM AUTHOR]

Fabricating an organic–inorganic nanocomposite hydrogel platform with antibacterial, anti-inflammatory, and osteoinductive properties that mimic bone extracellular matrix composition is decisive for guiding bone development in orthopedic practice. Despite significant progress in developing hydrogels for tissue repair, little attention has been paid to replicating the natural bone ECM microenvironments and addressing the importance of anti-inflammatory agents during osteogenesis. Herein, we developed ciprofloxacin and dexamethasone loaded strontium (Sr) and/or iron (Fe) substituted hydroxyapatite (HAp) nanomaterials precipitated in collagen (Col) to construct a multifunctional bioactive nanocomposite hydrogel platform to prevent inflammation and bacterial adhesion, leading to augmenting bone development in the defect site. The fabricated nanocomposite hydrogels (Sr:HAp-Col, Fe:HAp-Col, and Sr/Fe:HAp-Col) were physicochemically characterized and demonstrated high loading and prolonged drug release, and excellent antibacterial activity against Gram-positive and Gram-negative bacteria. In in vitro experiments, the Sr/Fe:HAp-Col sample exhibited enhanced bioactivity against the preosteoblast MC3T3-E1 cell line, with high alkaline phosphatase and bone-like inorganic calcium deposition, as well as increased gene expression of osteogenesis-related differentiation markers, including OPN, OCN, and RUNX2. Furthermore, in vivo experiments revealed that the Sr/Fe:HAp-Col matrix degraded over time by controlling the release of ions into the body, without causing acute inflammation at the implanted site or in the blood serum, or in the internal organs, including the heart, lungs, liver, and kidney of the Sprague–Dawley rat model. The micro-CT scan and histological examination showed high bone mineral density and more mature bone formation at the nanocomposite hydrogel implanted site associated with the ColMA hydrogel in the femur defect of the rat model. The strategy of applying collagen hydrogel supplemented with HAp to bone regeneration is promising due to its ability to mimic the natural bone ECM. Overall, the developed bioactive nanocomposite hydrogel may have great potential not only in bone regeneration but also in repairing nonunion-infected defects of other tissues. [ABSTRACT FROM AUTHOR]