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1.
From Supramolecular Hydrogels to Multifunctional Carriers for Biologically Active Substances.
Skopinska-Wisniewska, J, De la Flor, S, Kozlowska, J
International journal of molecular sciences. 2021;(14)
Abstract
Supramolecular hydrogels are 3D, elastic, water-swelled materials that are held together by reversible, non-covalent interactions, such as hydrogen bonds, hydrophobic, ionic, host-guest interactions, and metal-ligand coordination. These interactions determine the hydrogels' unique properties: mechanical strength; stretchability; injectability; ability to self-heal; shear-thinning; and sensitivity to stimuli, e.g., pH, temperature, the presence of ions, and other chemical substances. For this reason, supramolecular hydrogels have attracted considerable attention as carriers for active substance delivery systems. In this paper, we focused on the various types of non-covalent interactions. The hydrogen bonds, hydrophobic, ionic, coordination, and host-guest interactions between hydrogel components have been described. We also provided an overview of the recent studies on supramolecular hydrogel applications, such as cancer therapy, anti-inflammatory gels, antimicrobial activity, controlled gene drug delivery, and tissue engineering.
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2.
A review on Borassus flabellifer lignocellulose fiber reinforced polymer composites.
Singh, JK, Rout, AK, Kumari, K
Carbohydrate polymers. 2021;:117929
Abstract
Natural fiber composites play an important role for developing high performance engineering materials due to its facile availability, recyclability and eco-friendly nature. Borassus flabellifer products are significant and economical for urban and rural areas, and its fruit, leaf stalk and leaves are used in domestic purposes and some of them are disposed as waste. This waste part of Borassus flabellifer serves as a potential resource for natural fibers and utilized as raw material for reinforced polymer composites. The aim of this article narrates a comprehensive overview of Borassus fibers and its composites. Alkali treatment techniques, different fabrication methods, preparation of different matrices reinforced with bio-fibers and chemical, mechanical, thermal, morphological properties of Borassus fibers and its composites have been studied. Overall, this review article highlights, investigates and identifies gaps of the earlier research work, and provides the resourceful data for future work in various streams with Borassus fiber as reinforcement.
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3.
Recent advances of thermal properties of sugar palm lignocellulosic fibre reinforced polymer composites.
Asyraf, MRM, Ishak, MR, Norrrahim, MNF, Nurazzi, NM, Shazleen, SS, Ilyas, RA, Rafidah, M, Razman, MR
International journal of biological macromolecules. 2021;(Pt B):1587-1599
Abstract
Biocomposites are materials that are easy to manufacture and environmentally friendly. Sugar palm fibre (SPF) is considered to be an emerging reinforcement candidate that could provide improved mechanical stiffness and strength to the biocomposites. Numerous studies have been recently conducted on sugar palm biocomposites to evaluate their physical, mechanical and thermal properties in various conditions. Sugar palm biocomposites are currently limited to the applications of traditional household products despite their good thermal stability as a prospective substitute candidate for synthetic fibres. Thus, thermal analysis methods such as TGA and DTG are functioned to determine the thermal properties of single fibre sugar palm composites (SPCs) in thermoset and thermoplastic matrix as well as hybrid SPCs. The biocomposites showed a remarkable change considering thermal stability by varying the individual fibre compositions and surface treatments and adding fillers and coupling agents. However, literature that summarises the thermal properties of sugar palm biocomposites is unavailable. Particularly, this comprehensive review paper aims to guide all composite engineers, designers, manufacturers and users on the selection of suitable biopolymers for sugar palm biocomposites for thermal applications, such as heat shields and engine components.
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4.
Current methods and prospects of coronavirus detection.
Bu, J, Deng, Z, Liu, H, Li, J, Wang, D, Yang, Y, Zhong, S
Talanta. 2021;:121977
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Abstract
SARS-COV-2 is a novel coronavirus discovered in Wuhan in December 30, 2019, and is a family of SARS-COV (severe acute respiratory syndrome coronavirus), that is, coronavirus family. After infection with SARS-COV-2, patients often experience fever, cough, gas prostration, dyspnea and other symptoms, which can lead to severe acute respiratory syndrome (SARS), kidney failure and even death. The SARS-COV-2 virus is particularly infectious and has led to a global infection crisis, with an explosion in the number of infections. Therefore, rapid and accurate detection of the virus plays a vital role. At present, many detection methods are limited in their wide application due to their defects such as high preparation cost, poor stability and complex operation process. Moreover, some methods need to be operated by professional medical staff, which can easily lead to infection. In order to overcome these problems, a Surface molecular imprinting technology (SM-MIT) is proposed for the first time to detect SARS-COV-2 virus. For this SM-MIT method, this review provides detailed detection principles and steps. In addition, this method not only has the advantages of low cost, high stability and good specificity, but also can detect whether it is infected at designated points. Therefore, we think SM-MIT may have great potential in the detection of SARS-COV-2 virus.
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5.
Cutaneous Polymer-Coating Embolism After Endovascular Procedures: Report of Two Cases and a Literature Review.
Berríos-Hernández, M, Abou-Jokh Casas, C, Sainz-Gaspar, L, Ginarte-Val, J, Fernández Redondo, V, López-Otero, D, Aliste, C, Suárez-Peñaranda, JM
The American Journal of dermatopathology. 2021;(9):662-666
Abstract
Different hydrophilic and hydrophobic polymers are used as lubricious coatings to reduce vascular traumas in minimally invasive percutaneous procedures. Although they are usually very safe, there is still a risk of serious complications in patients undergoing such procedures, mostly derived from the devices' coating detachment and systemic embolization. The lungs are the most common organ involved, followed by the central nervous system. Yet, cutaneous embolization is unusual, and only 19 cases are available in the literature. Most commonly, they present as asymptomatic retiform purpura on the lower legs, which tends to involve spontaneously. Correct clinical diagnosis is not suspected in most cases, being cholesterol emboly or vasculitis the preferred options. Time interval since surgical procedure and appearance of lesions vary widely but they generally start in the first few days. Histopathological identification of the embolus as bluish, amorphous intraluminal material in dermal vessels is diagnostic, but vasculitic signs are not present. We report 2 cases of skin lesions as the main manifestation of polymer embolization after endovascular surgical procedures. In both cases, biopsy allowed identification of embolized foreign material and lesions resolved without specific treatment.
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6.
Did Cyclic Metaphosphates Have a Role in the Origin of Life?
Glonek, T
Origins of life and evolution of the biosphere : the journal of the International Society for the Study of the Origin of Life. 2021;(1):1-60
Abstract
How life began still eludes science life, the initial progenote in the context presented herein, being a chemical aggregate of primordial inorganic and organic molecules capable of self-replication and evolution into ever increasingly complex forms and functions.Presented is a hypothesis that a mineral scaffold generated by geological processes and containing polymerized phosphate units was present in primordial seas that provided the initiating factor responsible for the sequestration and organization of primordial life's constituents. Unlike previous hypotheses proposing phosphates as the essential initiating factor, the key phosphate described here is not a polynucleotide or just any condensed phosphate but a large (in the range of at least 1 kilo-phosphate subunits), water soluble, cyclic metaphosphate, which is a closed loop chain of polymerized inorganic phosphate residues containing only phosphate middle groups. The chain forms an intrinsic 4-phosphate helix analogous to its structure in Na Kurrol's salt, and as with DNA, very large metaphosphates may fold into hairpin structures. Using a Holliday-junction-like scrambling mechanism, also analogous to DNA, rings may be manipulated (increased, decreased, exchanged) easily with little to no need for additional energy, the reaction being essentially an isomerization.A literature review is presented describing findings that support the above hypothesis. Reviewed is condensed phosphate inorganic chemistry including its geological origins, biological occurrence, enzymes and their genetics through eukaryotes, polyphosphate functions, circular polynucleotides and the role of the Holliday junction, previous biogenesis hypotheses, and an Eoarchean Era timeline.
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7.
Metal Sulfide Semiconductor Nanomaterials and Polymer Microgels for Biomedical Applications.
Paca, AM, Ajibade, PA
International journal of molecular sciences. 2021;(22)
Abstract
The development of nanomaterials with therapeutic and/or diagnostic properties has been an active area of research in biomedical sciences over the past decade. Nanomaterials have been identified as significant medical tools with potential therapeutic and diagnostic capabilities that are practically impossible to accomplish using larger molecules or bulk materials. Fabrication of nanomaterials is the most effective platform to engineer therapeutic agents and delivery systems for the treatment of cancer. This is mostly due to the high selectivity of nanomaterials for cancerous cells, which is attributable to the porous morphology of tumour cells which allows nanomaterials to accumulate more in tumour cells more than in normal cells. Nanomaterials can be used as potential drug delivery systems since they exist in similar scale as proteins. The unique properties of nanomaterials have drawn a lot of interest from researchers in search of new chemotherapeutic treatment for cancer. Metal sulfide nanomaterials have emerged as the most used frameworks in the past decade, but they tend to aggregate because of their high surface energy which triggers the thermodynamically favoured interaction. Stabilizing agents such as polymer and microgels have been utilized to inhibit the particles from any aggregations. In this review, we explore the development of metal sulfide polymer/microgel nanocomposites as therapeutic agents against cancerous cells.
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8.
How Can a Polymeric Formula Induce Remission in Crohn's Disease Patients?
Boumessid, K, Barreau, F, Mas, E
International journal of molecular sciences. 2021;(8)
Abstract
Crohn's disease is an inflammatory bowel disease whose prevalence is increasing worldwide. Among medical strategies, dietary therapy with exclusive enteral nutrition is recommended as a first-line option, at least for children, because it induces clinical remission and mucosal healing. Modulen®, a polymeric TGF-β2 enriched formula, has good palatability and is widely used. For the first time in the literature, this review outlines and discusses the clinical outcomes obtained with this therapy, as well as the potential mechanisms of action of its compounds. It can be explained by its TGF-β2 content, but also by its protein and lipid composition. Further well-designed studies are required to improve our knowledge and to optimize therapeutic strategies.
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9.
Phenols and Melanoidins as Natural Antioxidants in Beer. Structure, Reactivity and Antioxidant Activity.
Martinez-Gomez, A, Caballero, I, Blanco, CA
Biomolecules. 2020;(3)
Abstract
Beer is one of the most consumed drinks around the world, containing a variety of compounds that offer both appreciated sensorial characteristics and health advantages. Important healthy compounds in beer are those with antioxidant properties that attenuate the content of free radicals produced as by-products in the human metabolism, exerting an appreciable effect against cancers or cardiovascular diseases. This work details a study of antioxidant compounds present in beer, focusing on the two main groups: phenols (including polyphenolic forms) and melanoidins, formed specifically during brewing as Maillard products. The fundaments of the most important methods to evaluate beer antioxidant activity, the main antioxidant compounds present in beer-especially those with healthy properties-and the new trends to increase beer antioxidant activity are also discussed.
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10.
The Hot Spring Hypothesis for an Origin of Life.
Damer, B, Deamer, D
Astrobiology. 2020;(4):429-452
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Abstract
We present a testable hypothesis related to an origin of life on land in which fluctuating volcanic hot spring pools play a central role. The hypothesis is based on experimental evidence that lipid-encapsulated polymers can be synthesized by cycles of hydration and dehydration to form protocells. Drawing on metaphors from the bootstrapping of a simple computer operating system, we show how protocells cycling through wet, dry, and moist phases will subject polymers to combinatorial selection and draw structural and catalytic functions out of initially random sequences, including structural stabilization, pore formation, and primitive metabolic activity. We propose that protocells aggregating into a hydrogel in the intermediate moist phase of wet-dry cycles represent a primitive progenote system. Progenote populations can undergo selection and distribution, construct niches in new environments, and enable a sharing network effect that can collectively evolve them into the first microbial communities. Laboratory and field experiments testing the first steps of the scenario are summarized. The scenario is then placed in a geological setting on the early Earth to suggest a plausible pathway from life's origin in chemically optimal freshwater hot spring pools to the emergence of microbial communities tolerant to more extreme conditions in dilute lakes and salty conditions in marine environments. A continuity is observed for biogenesis beginning with simple protocell aggregates, through the transitional form of the progenote, to robust microbial mats that leave the fossil imprints of stromatolites so representative in the rock record. A roadmap to future testing of the hypothesis is presented. We compare the oceanic vent with land-based pool scenarios for an origin of life and explore their implications for subsequent evolution to multicellular life such as plants. We conclude by utilizing the hypothesis to posit where life might also have emerged in habitats such as Mars or Saturn's icy moon Enceladus. "To postulate one fortuitously catalyzed reaction, perhaps catalyzed by a metal ion, might be reasonable, but to postulate a suite of them is to appeal to magic." -Leslie Orgel.