Abstract Over the past few decades, nanoparticles of noble metals such as silver exhibited significantly distinct physical, chemical and biological properties from their bulk counterparts. Nano-size particles of less than 100 nm in diameter are currently attracting increasing attention for the wide range of new applications in various fields of industry. Such powders can exhibit properties that differ substantially from those of bulk materials, as a result of small particle dimension, high surface area, quantum confinement and other effects. Most of the unique properties of nanoparticles require not only the particles to be of nano-sized, but also the particles be dispersed without agglomeration. Discoveries in the past decade have clearly demonstrated that the electromagnetic, optical and catalytic properties of silver nanoparticles are strongly influenced by shape, size and size distribution, which are often varied by varying the synthetic methods, reducing agents and stabilizers. Accordingly, this review presents different methods of preparation silver nanoparticles and application of these nanoparticles in different fields.
Near-infrared (NIR) spectroscopy has come of age and is now prominent among major analytical technologies after the NIR region was discovered in 1800, revived and developed in the early 1950s and put into practice in the 1970s. Since its first use in the cereal industry, it has become the quality control method of choice for many more applications due to the advancement in instrumentation, computing power and multivariate data analysis. NIR spectroscopy is also increasingly used during basic research performed to better understand complex biological systems, e.g. by means of studying characteristic water absorption bands. The shorter NIR wavelengths (800-2500 nm), compared to those in the mid-infrared (MIR) range (2500-15 000 nm) enable increased penetration depth and subsequent non-destructive, non-invasive, chemical-free, rapid analysis possibilities for a wide range of biological materials. A disadvantage of NIR spectroscopy is its reliance on reference methods and model development using chemometrics. NIR measurements and predictions are, however, considered more reproducible than the usually more accurate and precise reference methods. The advantages of NIR spectroscopy contribute to it now often being favoured over other spectroscopic (colourimetry and MIR) and analytical methods, using chemicals and producing chemical waste, such as gas chromatography (GC) and high performance liquid chromatography (HPLC). This tutorial review intends to provide a brief overview of the basic theoretical principles and most investigated applications of NIR spectroscopy. In addition, it considers the recent development, principles and applications of NIR hyperspectral imaging. NIR hyperspectral imaging provides NIR spectral data as a set of images, each representing a narrow wavelength range or spectral band. The advantage compared to NIR spectroscopy is that, due to the additional spatial dimension provided by this technology, the images can be analysed and visualised as chemical images providing identification as well as localisation of chemical compounds in non-homogenous samples.
Abstract Red mud is a solid waste produced during the bauxite refining of alumina. In recent years, environmental problems caused by the accumulation of red mud have become increasingly serious. In order to understand the status of red mud recovery in recent years, this article uses a comprehensive literature database to classify and statistically analyze red mud-related publications from 2010 to 2019. The results show that research on the comprehensive utilization of red mud is mainly found in three fields: the construction and chemical industry, the environmental protection and agriculture industry, and the valuable elements extraction industry. A brief report is also made on the related research of red mud in the fields of cement, concrete, glass, ceramics, adsorbents, geopolymers, catalysts, composite materials, sewage treatment, waste gas treatment, soil improvement, and valuable element recovery. The current industrial consumption of red mud in China is measured, and some suggestions for solving the red mud problem are put forward.
Synthetic innovation in drug development Chemical synthesis plays a key role in pharmaceutical research and development. Campos et al. review some of the advantages that have come from recent innovations in synthetic methods. In particular, they highlight small-molecule catalysts stimulated by visible light, enzymes engineered for versatility beyond their intrinsic function, and bio-orthogonal reactions to selectively modify proteins for conjugation. High-throughput techniques are also poised to accelerate methods optimization from small-scale discovery to large-scale production, and complementary machine-learning approaches are just coming into focus. Science, this issue p. eaat0805 BACKGROUND Over the past century, innovations in synthetic chemistry have greatly enabled the discovery and development of important life-changing medicines, improving the health of patients worldwide. In recent years, many pharmaceutical companies have chosen to reduce their R&D investment in chemistry, viewing synthetic chemistry more as a mature technology and less as a driver of innovation in drug discovery. Contrary to this opinion, we believe that excellence and innovation in synthetic chemistry continue to be critical to success in all phases of drug discovery and development. Moreover, recent developments in new synthetic methods, biocatalysis, chemoinformatics, and reaction miniaturization have the power to accelerate the pace and improve the quality of products in pharmaceutical research. Indeed, the application of new synthetic methods is rapidly expanding the realm of accessible chemical matter for modulating a broader array of biological targets, and there is a growing recognition that innovations in synthetic chemistry are changing the practice of drug discovery. We identify some of the most enabling recent advances in synthetic chemistry as well as opportunities that we believe are poised to transform the practice of drug discovery and development in the coming years. ADVANCES Over the past century, innovations in synthetic methods have changed the way scientists think about designing and building molecules, enabling access to more expansive chemical space and to molecules possessing the essential biological activity needed in future investigational drugs. In order for the pharmaceutical industry to continue to produce breakthrough therapies that address global health needs, there remains a critical need for invention of synthetic transformations that can continue to drive new drug discovery. Toward this end, investment in research directed toward synthetic methods innovation, furthering the nexus of synthetic chemistry and biomolecules, and developing new technologies to accelerate methods discovery is essential. One powerful example of an emerging, transformative synthetic method is the recent discovery of photoredox catalysis, which allows one to harness the energy of visible light to accomplish synthetic transformations on drug-like molecules that were previously unachievable. Furthermore, recent breakthroughs in molecular biology, bioinformatics, and protein engineering are driving rapid identification of biocatalysts that possess desirable stability, unique activity, and exquisite selectivity needed to accelerate drug discovery. Recent developments in the merging fields of synthetic and biosynthetic chemistry have sought to harness these molecules in three distinct ways: as biocatalysts for novel and selective transformations, as conjugates through innovative bio-orthogonal chemistry, and in the development of improved therapeutic modalities. The development of high-throughput experimentation and analytical tools for chemistry has made it possible to execute more than 1500 simultaneous experiments at microgram scale in 1 day, enabling the rapid identification of suitable reaction conditions to explore chemical space and accelerate drug discovery. Finally, advances in computational chemistry and machine learning in the past decade are delivering real impact in areas such as new catalyst design, reaction prediction, and even new reaction discovery. OUTLOOK These advances position synthetic chemistry to continue to have an impact on the discovery and development of the next generation of medicines. Key unsolved problems in synthetic chemistry with potential implications for drug discovery include selective saturation and functionalization of heteroaromatics; concise synthesis of highly functionalized, constrained bicyclic amines; and C-H functionalization for the synthesis of α,α,α-trisubstituted amines. Other areas, such as site-selective modification of biomolecules and synthesis of noncanonical nucleosides, are emerging as opportunities of high potential impact. The concept of molecular editing, whereby one could selectively insert, delete, or exchange atoms in highly elaborated molecules, is an area of emerging interest. Continued investment in synthetic chemistry and chemical technologies through partnerships between the pharmaceutical industry and leading academic groups holds great promise to advance the field closer to a state where exploration of chemical space is unconstrained by synthetic complexity and only limited by the imagination of the chemist, enabling the discovery of the optimal chemical matter to treat disease faster than ever before. Evolution of synthesis as a driver of innovation in drug discovery. Past, present, and future advances in synthetic chemistry are poised to transform the practice of drug discovery and development. Innovations in synthetic chemistry have enabled the discovery of many breakthrough therapies that have improved human health over the past century. In the face of increasing challenges in the pharmaceutical sector, continued innovation in chemistry is required to drive the discovery of the next wave of medicines. Novel synthetic methods not only unlock access to previously unattainable chemical matter, but also inspire new concepts as to how we design and build chemical matter. We identify some of the most important recent advances in synthetic chemistry as well as opportunities at the interface with partner disciplines that are poised to transform the practice of drug discovery and development.
Ismaël Amghizar, Laurien A. Vandewalle, K. V. Geem
et al.
Abstract Most olefins (e.g., ethylene and propylene) will continue to be produced through steam cracking (SC) of hydrocarbons in the coming decade. In an uncertain commodity market, the chemical industry is investing very little in alternative technologies and feedstocks because of their current lack of economic viability, despite decreasing crude oil reserves and the recognition of global warming. In this perspective, some of the most promising alternatives are compared with the conventional SC process, and the major bottlenecks of each of the competing processes are highlighted. These technologies emerge especially from the abundance of cheap propane, ethane, and methane from shale gas and stranded gas. From an economic point of view, methane is an interesting starting material, if chemicals can be produced from it. The huge availability of crude oil and the expected substantial decline in the demand for fuels imply that the future for proven technologies such as Fischer-Tropsch synthesis (FTS) or methanol to gasoline is not bright. The abundance of cheap ethane and the large availability of crude oil, on the other hand, have caused the SC industry to shift to these two extremes, making room for the on-purpose production of light olefins, such as by the catalytic dehydrogenation of propane.
Targeted protein degradation (TPD) has emerged as an exciting new era in chemical biology and drug discovery. PROteolysis TArgeting Chimera (PROTAC) technology targets cellular proteins for degradation by co-opting the ubiquitin-proteasome system. Over the last 5 years, numerous studies have expanded our understanding of the unique mode of action and advantages of PROTACs, which has in turn spurred interest in both academia and industry to explore PROTACs as a novel therapeutic strategy. In this review, we first highlight the key advantages of PROTACs and then discuss the spatiotemporal regulation of protein degradation. Next, we explore current chemically tractable E3 ligases focusing on expanding the existing repertoire with novel E3 ligases to uncover the full potential of TPD. Collectively, these studies are guiding the development of the PROTAC technology as it emerges as a new modality in precision medicine.
Srivathsan Poyyapakkam Sundar, Vibin Abraham, Bo Peng
et al.
Progress towards quantum utility in chemistry requires not only algorithmic advances, but also the identification of chemically meaningful problems whose electronic structure fundamentally challenges classical methods. Here, we introduce a curated hierarchy of chemically decisive benchmark systems designed to probe distinct regimes of electronic correlation relevant to molecular, bioinorganic, and heavy-element chemistry. Moving beyond minimal toy models, our benchmark set spans multireference bond breaking (N$_2$), high-spin transition-metal chemistry (FeS), biologically relevant iron-sulfur clusters ([2Fe-2S]), and actinide-actinide bonding (U$_2$), which exhibits extreme sensitivity to active-space choice, relativistic treatment, and correlation hierarchy even within advanced multireference frameworks. As a concrete realization, we benchmark a recently developed automated and adaptive quantum algorithm based on generator-coordinate-inspired subspace expansion,ADAPT-GCIM, using a black-box workflow that integrates entropy-based active-space selection via the ActiveSpaceFinder tool. Across this chemically diverse problem set, ADAPT-GCIM achieves high accuracy in challenging correlation regimes. Equally importantly, these benchmarks expose general failure modes and design constraints-independent of any specific algorithm-highlighting the necessity of problem-aware and correlation-specific strategies for treating strongly correlated chemistry on quantum computers. To support systematic benchmarking and reproducible comparisons, the Hamiltonians for all systems studied are made openly available.
Adnan, Seham M. Al-Mekhlafi, Mutasem Z. Bani-Fwaz
et al.
Abstract Use of nanomaterials for improved thermal applications is a vibrant research area. These applications frequently occur in mechanical, thermal, chemical, and paint industries. Selection of individual nanomaterial characteristics is important to achieve fine results. Thus, the current work aims to study a problem by utilizing the unique structural properties of CNTs nanomaterials and (C2H6O2-H2O) 50:50% with key focus on the diameter and length factors involves in the thermal conductivity. The problem is then formulated for entropy and heat transfer through the use of similarity transforms and induction of controls like radiations, dissipation, mixed convection and convective heat condition effects. The bvp4c scheme is adopted for the entropy and heat results with multiple ranges. Dissipation, radiations and convective effects provided considerable increase in the temperature due to transfer of heat energy in the fluid. The temperature is examined very high near the surface due to convective factor. The mixed convection action over magnetically conducted nanofluid help to reduce the temperature and beneficial for engineering purpose with low heat transfer requirements. The Biot and Brinkman number boosted the entropy while declines for radiations and angle variations. Moreover, the Eckert number maintain the system at high entropy. The skin friction enhanced from 1.054470 to 1.6544 for against string Lorentz forces, 0.968471 to 0.987829 for $$\:\lambda\:$$ , and 105.447% to 165.44%. Use of Kyamada−Ota characteristics positively contributed in the thermal and entropy results which enhance applicability of the model.
The lifetime of Si bond coats in environmental barrier coatings (EBCs) is constrained by phase transition-induced cracking at the SiO₂ scale. In this study, reactive self-consumption and lattice solid solution strategies are employed to address this limitation via Si–Yb₄Al₂O₉ composite coatings. The formation of an Yb₂Si₂O₇ layer, through the consumption of the thermally grown SiO₂ scale and Yb₄Al₂O₉, reduces the SiO₂ thickness and significantly lowers the cracking driving force. Furthermore, the incorporation of Al into the SiO₂ lattice stabilizes high-temperature β-SiO₂, preventing phase transition-induced cracking. The proposed coating demonstrated an oxidation lifetime 20 times longer than that of pure Si at 1370 °C, highlighting its potential as an EBC bond coating.
Debarshi Banerjee, Khatereh Azizi, Colin K. Egan
et al.
The use of computer simulations to study the properties of aqueous systems is, today more than ever, an active area of research. In this context, during the last decade there has been a tremendous growth in the use of data-driven approaches to develop more accurate potentials for water as well as to characterize its complexity in chemical and biological contexts. We highlight the progress, giving a historical context, on the path to the development of many-body and reactive potentials to model aqueous chemistry, including the role of machine learning strategies. We focus specifically on conceptual and methodological challenges along the way in performing simulations that seek to tackle problems in modeling the chemistry of aqueous solutions. In conclusion, we summarize our perspectives on the use and integration of advanced data-science techniques to provide chemical insights in physical chemistry and how this will influence computer simulations of aqueous systems in the future.