Asymmetric Flow Field-Flow Fractionation: Current Status,Possibilities, Analytical Limitations and Future Trends

Chromatographia - The development and applications of asymmetric flow field-flow fractionation (AF4) are outlined in comparison with the older and better-known size exclusion chromatography. Recent...     

Correction to: Asymmetric Flow Field-Flow Fractionation: Current Status,Possibilities, Analytical Limitations and Future Trends

Chromatographia - A correction to this paper has been published: https://doi.org/10.1007/s10337-021-04054-7     

Melanoma Chemoprevention: Current Status and Future Prospects

The incidence of skin cancers, both nonmelanoma and melanoma, is increasing in the United States. The ultraviolet radiation, mainly from sun, is considered the major cause for these neoplasms. While nonmelanoma skin cancers are far more numerous, melanoma remains the most challenging. This is because melanoma can become extremely aggressive and its incidence is increasing worldwide due to lack of effective early detection, as well as disease recurrence, following both surgery and chemotherapy. Therefore, in addition to better treatment options, newer means are required to prevent melanomas from developing. Chemoprevention is a reasonable cost‐effective approach to prevent carcinogenesis by inhibiting the processes of tumor initiation, promotion and progression. Melanoma is a progressive disease, which makes it very suitable for chemopreventive interventions, by targeting the processes and molecular pathways involved in the progression of melanoma. This review discusses the roles of various chemopreventive agents such as NSAIDs, statins, vitamins and dietary agents in melanoma and highlights current advancements and our perspective on future of melanoma chemoprevention. Although considerable preclinical data suggest that melanoma may be prevented or delayed by a numerous chemopreventive agents, we realize there are insufficient clinical studies evaluating their efficacy and long‐term safety for human use.     

聚合物功能梯度材料的研究现状与展望

功能梯度材料(FGM)是一种全新的非均质复合材料.聚合物梯度材料(PGM)是基体材料为高分子材料的一类功能梯度材料,因其独特的形态结构、奇特的功能和潜在的应用价值,已逐渐引起了人们的高度重视.本文综述了国内外聚合物功能梯度材料的研究现状,介绍了PGM的概念、分类、制备方法、表征方法及应用等,并对PGM未来的研究进行了展望.     

Controlled Drug Delivery Systems: Current Status and Future Directions

The drug delivery system enables the release of the active pharmaceutical ingredient to achieve a desired therapeutic response. Conventional drug delivery systems (tablets, capsules, syrups, ointments, etc.) suffer from poor bioavailability and fluctuations in plasma drug level and are unable to achieve sustained release. Without an efficient delivery mechanism, the whole therapeutic process can be rendered useless. Moreover, the drug has to be delivered at a specified controlled rate and at the target site as precisely as possible to achieve maximum efficacy and safety. Controlled drug delivery systems are developed to combat the problems associated with conventional drug delivery. There has been a tremendous evolution in controlled drug delivery systems from the past two decades ranging from macro scale and nano scale to intelligent targeted delivery. The initial part of this review provides a basic understanding of drug delivery systems with an emphasis on the pharmacokinetics of the drug. It also discusses the conventional drug delivery systems and their limitations. Further, controlled drug delivery systems are discussed in detail with the design considerations, classifications and drawings. In addition, nano-drug delivery, targeted and smart drug delivery using stimuli-responsive and intelligent biomaterials is discussed with recent key findings. The paper concludes with the challenges faced and future directions in controlled drug delivery.     

Radiation Chemistry and Radiation Technology at the Boundary of the Centuries: The Current Status and Prospects for Development

A brief review of the current status of radiation chemistry and radiation technology is presented. Particular attention is focused on the results of studies performed in the last five to six years of the 20th century. Data on the most important branches and the most considerable advances in modern radiation chemistry are given. Recent achievements in radiation technology are summarized. A forecast of the development of radiation chemistry and radiation technology technology for the next few decades is made.     

Panax quinquefolius (North American Ginseng) Polysaccharides as Immunomodulators: Current Research Status and Future Directions

Panax quinquefolius (North American ginseng, NAG) is a popular medicinal plant used widely in traditional medicine. NAG products are currently available in various forms such as roots, extracts, nutraceuticals, dietary supplements, energy drinks, etc. NAG polysaccharides are recognized as one of the major bioactive ingredients. However, most NAG reviews are focused on ginsenosides with little information on polysaccharides. NAG polysaccharides have demonstrated a therapeutic activity in numerous studies, in which many of the bioactivities involve regulation of the immune response. The purpose of this review is to summarize the structural features and the immunomodulatory properties of crude, partially purified, and pure polysaccharides isolated from NAG. Receptors of the innate immune system that potentially bind to NAG polysaccharides and the respective signal transduction pathways initiated by these compounds are discussed. Major challenges, recent innovations, and future directions in NAG polysaccharide research are also summarized.     

全无机钙钛矿太阳电池: 现状与未来

近年来,基于ABX₃结构的有机无机杂化钙钛矿材料因其具有优良的光电特性和廉价的制作成本得到了全世界的广泛关注,但体系中的有机组分容易受到光、热、湿等外界条件的影响而分解,导致器件的PCE发生严重的下降,极大地限制了PSCs(Perovskite solar cells, PSCs)的产业化进程。利用纯无机阳离子完全取代ABX₃结构中的A位有机阳离子制备出全无机钙钛矿材料,因其优异的热稳定性和环境稳定性而得到了快速的发展。现阶段,基于全无机钙钛矿材料的全无机钙钛矿太阳能电池(I-PSCs)的效率已超过19%,应用前景广阔。本文回顾了近年来全无机钙钛矿材料的研究进展,对不同类型的全无机钙钛矿材料进行了综述和讨论,从成膜工艺、掺杂工程、后处理工程等方面论述了如何提升器件的稳定性。最后,对I-PSCs的大面积制备及其柔性应用进行了介绍,揭示了I-PSCs面临的挑战,并对该领域进行了展望。     

Speciation and Bioavailability:Present Status and Future Trend

Speciation analysis is nowadays performed routinely in environmental chemistry to control the quality of the environment and to study the behavior of inorganic speciation and organometallic compounds.     

Future Trends in Rubber Processing: The Chemistry of Rubber Processing

Abstract

Future trends in rubber processing are discussed with special emphasis on the chemical aspects that might be used to develop new and improved properties of rubber materials. They include optimization of such properties as resiliency and “softness,” of reinforcement and the control of crosslinking, and of the crosslink densities of rubbers during vulcanization.     

Single Chain Folding of Synthetic Polymers by Covalent and Non‐Covalent Interactions: Current Status and Future Perspectives

The present feature article highlights the preparation of polymeric nanoparticles and initial attempts towards mimicking the structure of natural biomacromolecules by single chain folding of well‐defined linear polymers through covalent and non‐covalent interactions. Initially, the discussion focuses on the synthesis and characterization of single chain self‐folded structures by non‐covalent interactions. The second part of the article summarizes the folding of single chain polymers by means of covalent interactions into nanoparticle systems. The current state of the art in the field of single chain folding indicates that covalent‐bond‐driven nanoparticle preparation is well advanced, while the first encouraging steps towards building reversible single chain folding systems by the use of mutually orthogonal hydrogen‐bonding motifs have been made.     

Nanotherapeutic Anti-influenza Solutions: Current Knowledge and Future Challenges

Nanotechnology has impacted every aspect of human life and the environment. The raising concern against influenza outbreaks is an ongoing issue. With the current drugs and natural remedies, some amount of resolution has been reached. Yet, nothing conclusive has been achieved. With every resource tapped, it is now time to combine strategies. This review highlights the low enthusiasm in this area, where not much has been probed into employing nanomaterials into influenza research. The achievements made through the intervention of nanotechnology into anti influenza research, has been surveyed in this review. Except for a few, not much progress was evidenced. Although significant progress has been achieved with nano inputs, yet nothing much has been done in this direction. This review emphasizes the need to combine strategies and find new remedies against influenza virus using nano platforms. New directions and future perspectives for accessing the nano inputs for combating the influenza issues have been discussed.     

Sol-Gel Science and Technology: Current State and Future Prospects

This paper addresses the current state and future prospects of sol-gel processing. It summarizes responses to a questionnaire received from more than four dozen leaders of the sol-gel community. Overall, the respondents remain quite sanguine about the future prospects for the field, and with numerous areas where sol-gel processing can provide unique capabilities and novel materials. The present authors acknowledge this potential, but argue that its achievement will depend upon greatly increased involvement of the sol-gel community with applications, and carrying out a much larger fraction of sol-gel research in the context of applications.     

生命元素与营养、健康的研究现状、问题分析及其展望

综述了生命元素与人类营养和健康的研究现状，并对生命元素研究的局限性和产生问题的原因进行了多角度的探讨。作者认为，今后对生命元素的研究应注重生物有机体中生命元素生态系统的整体性、系统性和元素整体的比例平衡及其互作关系。     

Current Status,Distribution, and Future Directions of Natural Products against Colorectal Cancer in Indonesia: A Systematic Review

In 2020, an estimated 19.3 million new cancer cases and nearly 10 million cancer deaths have occurred worldwide, with colorectal cancer ranking as the third most frequently diagnosed (10.0%). Several attempts have been conducted against cancer, including surgery, radiation, monoclonal antibodies, and chemotherapy. Many people choose natural products as alternatives against cancer. These products will not only help in human life preservation but also work as a source of up-to-date information, leading people away from incorrect information. We discuss the current status, distribution, and future implications of protecting populations with natural products as an alternative against colorectal cancer in Indonesia. Thirty-eight studies were included in this review for data extraction. The distribution of natural products in Indonesia that have potential activity against colorectal cancer cells was predominated by terpenoids, followed by phytosterols, phenolics, alkaloids, and polyisoprenoids. The type of cell line utilized in the cytotoxic activity analysis of natural products was the WiDr cell line, followed by HT-29 cells and HCT-116 cells. This review showed that MTT in vitro assay is a general method used to analyze the cytotoxic activity of a natural product against colorectal cancer cells, followed by other in vitro and in vivo methods. The systematic review provided predictions for several secondary metabolites to be utilized as an alternative treatment against colorectal cancer in Indonesia. It also might be a candidate for a future co-chemotherapy agent in safety, quality, and standardization. In addition, computational methods are being developed to predict the drug-likeness of compounds, thus, drug discovery is already on the road towards electronic research and development.     

Determining Free‐Radical Propagation Rate Coefficients with High‐Frequency Lasers: Current Status and Future Perspectives

Detailed knowledge of the polymerization mechanisms and kinetics of academically and industrially relevant monomers is mandatory for the precision synthesis of tailor‐made polymers. The IUPAC‐recommended pulsed‐laser polymerization–size exclusion chromatography (PLP–SEC) approach is the method of choice for the determination of propagation rate coefficients and the associated Arrhenius parameters for free radical polymerization processes. With regard to specific monomer classes—such as acrylate‐type monomers, which are very important from a materials point of view—high laser frequencies of up to 500 Hz are mandatory to prevent the formation of mid‐chain radicals and the occurrence of chain‐breaking events by chain transfer, if industrially relevant temperatures are to be reached and wide temperature ranges are to be explored (up to 70 °C). Herein the progress and state‐of‐the‐art of high‐frequency PLP–SEC with pulse repetition rates of 500 Hz is reported, with a critical collection of to‐date investigated 500 Hz data as well as future perspectives for the field.

     

PET Oncological Radiopharmaceuticals: Current Status and Perspectives

Molecular imaging is the visual representation of biological processes that take place at the cellular or molecular level in living organisms. To date, molecular imaging plays an important role in the transition from conventional medical practice to precision medicine. Among all imaging modalities, positron emission tomography (PET) has great advantages in sensitivity and the ability to obtain absolute imaging quantification after corrections for photon attenuation and scattering. Due to the ability to label a host of unique molecules of biological interest, including endogenous, naturally occurring substrates and drug-like compounds, the role of PET has been well established in the field of molecular imaging. In this article, we provide an overview of the recent advances in the development of PET radiopharmaceuticals and their clinical applications in oncology.     

RNAi for Insect Control: Current Perspective and Future Challenges

The research on the RNA interference (RNAi) for the control of insect pests has made significant growth in recent years. The availability of the genomic sequences of insects has further widened the horizons for the testing of this technology to various insect groups. Different modes of application of double-stranded RNA (dsRNA) have been tested; however, the practicability of delivery of dsRNA in insects still remains the biggest challenge. Till date, the oral delivery of dsRNA in insects is one of the efficient approaches for the practical application of this technique. The uptake of dsRNA from the insect gut is mediated either by SID-1/SID-2 transmembrane proteins or by endocytosis; however, the systemic RNAi machinery still remains to be revealed in insect species. The RNAi-mediated gene knockdown has shown striking results in different insect groups, pointing it to be the upcoming technique for insect control. However, before the successful application of this technique for insect control, some potential issues need to be resolved. This review presents the account of prospects and challenges for the use of this technology for insect control.     

A Mechanistic Overview of the Current Status and Future Challenges in Air Cathode for Aluminum Air Batteries

Aluminum air batteries (AABs) are a desirable option for portable electronic devices and electric vehicles (EVs) due to their high theoretical energy density (8100 Wh K⁻¹), low cost, and high safety compared to state-of-the-art lithium-ion batteries (LIBs). However, numerous unresolved technological and scientific issues are preventing AABs from expanding further. One of the key issues is the catalytic reaction kinetics of the air cathode as the fuel (oxygen) for AAB is reduced there. Additionally, the performance and price of an AAB are directly influenced by an air electrode integrated with an oxygen electrocatalyst, which is thought to be the most crucial element. In this study, we covered the oxygen chemistry of the air cathode as well as a brief discussion of the mechanistic insights of active catalysts and how they catalyze and enhance oxygen chemistry reactions. There is also extensive discussion of research into electrocatalytic materials that outperform Pt/C such as nonprecious metal catalysts, metal oxide, perovskites, metal-organic framework, carbonaceous materials, and their composites. Finally, we provide an overview of the present state, and possible future direction for air cathodes in AABs.     

A Mechanistic Overview of the Current Status and Future Challenges of Aluminum Anode and Electrolyte in Aluminum-Air Batteries

Aluminum-air batteries (AABs) are regarded as attractive candidates for usage as an electric vehicle power source due to their high theoretical energy density (8100 Wh kg⁻¹), which is considerably higher than that of lithium-ion batteries. However, AABs have several issues with commercial applications. In this review, we outline the difficulties and most recent developments in AABs technology, including electrolytes and aluminum anodes, as well as their mechanistic understanding. First, the impact of the Al anode and alloying on battery performance is discussed. Then we focus on the impact of electrolytes on battery performances. The possibility of enhancing electrochemical performances by adding inhibitors to electrolytes is also investigated. Additionally, the use of aqueous and non-aqueous electrolytes in AABs is also discussed. Finally, the challenges and potential future research areas for the advancement of AABs are suggested.