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Materials for Nuclear Waste Immobilization

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ISBN: 9783039218462 9783039218479 Year: Pages: 220 DOI: 10.3390/books978-3-03921-847-9 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: General and Civil Engineering --- Technology (General)
Added to DOAB on : 2020-01-30 16:39:46
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The book outlines recent advances in nuclear wasteform materials including glasses, ceramics and cements and spent nuclear fuel. It focuses on durability aspects and contains data on performance of nuclear wasteforms as well as expected behavior in a disposal environment.

Asymmetric and Selective Biocatalysis

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ISBN: 9783038978466 9783038978473 Year: Pages: 154 DOI: 10.3390/books978-3-03897-847-3 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Chemistry (General)
Added to DOAB on : 2019-06-26 09:16:44
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This Issue contains one communication, six articles, and two reviews. The communication from Paola Vitale et al. represents a work where whole cells were used as biocatalysts for the reduction of optically active chloroalkyl arylketones followed by a chemical cyclization to give the desired heterocycles. Among the various whole cells screened (baker’s yeast, Kluyveromyces marxianus CBS 6556, Saccharomyces cerevisiae CBS 7336, Lactobacillus reuteri DSM 20016), baker’s yeast provided the best yields and the highest enantiomeric ratios (95:5) in the bioreduction of the above ketones. In this respect, valuable chiral non-racemic functionalized oxygen-containing heterocycles (e.g., (S)-styrene oxide, (S)-2-phenyloxetane, (S)-2-phenyltetrahydrofuran), amenable to be further elaborated on, can be smoothly and successfully generated from their prochiral precursors. Studies about pure biocatalysts with mechanistical studies, application in different reactions, and new immobilization methods for improving their stability were reported in five different articles. The article by Su-Yan Wang et al. describes the cloning, expression, purification, and characterization of an N-acetylglucosamine 2-epimerase from Pedobacter heparinus (PhGn2E). For this, several N-acylated glucosamine derivatives were chemically synthesized and used to test the substrate specificity of the enzyme. The mechanism of the enzyme was studied by hydrogen/deuterium NMR. The study at the anomeric hydroxyl group and C-2 position of the substrate in the reaction mixture confirmed the epimerization reaction via ring-opening/enolate formation. Site-directed mutagenesis was also used to confirm the proposed mechanism of this interesting enzyme. The article by Forest H. Andrews et al. studies two enzymes, benzoylformate decarboxylase (BFDC) and pyruvate decarboxylase (PDC), which catalyze the non-oxidative decarboxylation of 2-keto acids with different specificity. BFDC from Pseudomonas putida exhibited very limited activity with pyruvate, whereas the PDCs from S. cerevisiae or from Zymomonas mobilis showed virtually no activity with benzoylformate (phenylglyoxylate). After studies using saturation mutagenesis, the BFDC T377L/A460Y variant was obtained, with 10,000-fold increase in pyruvate/benzoylformate. The change was attributed to an improvement in the Km value for pyruvate and a decrease in the kcat value for benzoylformate. The characterization of the new catalyst was performed, providing context for the observed changes in the specificity. The article by Xin Wang et al. compares two types of biocatalysts to produce D-lysine L-lysine in a cascade process catalyzed by two enzymes: racemase from microorganisms that racemize L-lysine to give D,L-lysine and decarboxylase that can be in cells, permeabilized cells, and the isolated enzyme. The comparison between the different forms demonstrated that the isolated enzyme showed the higher decarboxylase activity. Under optimal conditions, 750.7 mmol/L D-lysine was finally obtained from 1710 mmol/L L-lysine after 1 h of racemization reaction and 0.5 h of decarboxylation reaction. D-lysine yield could reach 48.8% with enantiomeric excess (ee) of 99%. In the article by Rivero and Palomo, lipase from Candida rugosa (CRL) was highly stabilized at alkaline pH in the presence of PEG, which permitted its immobilization for the first time by multipoint covalent attachment on different aldehyde-activated matrices. Different covalent immobilized preparation of the enzyme was successfully obtained. The thermal and solvent stability was highly increased by this treatment, and the novel catalysts showed high regioselectivity in the deprotection of per-O-acetylated nucleosides. The article by Robson Carlos Alnoch et al. describes the protocol and use of a new generation of tailor-made bifunctional supports activated with alkyl groups that allow the immobilization of proteins through the most hydrophobic region of the protein surface and aldehyde groups that allows the covalent immobilization of the previously adsorbed proteins. These supports were especially used in the case of lipase immobilization. The immobilization of a new metagenomic lipase (LipC12) yielded a biocatalyst 3.5-fold more active and 5000-fold more stable than the soluble enzyme. The PEGylated immobilized lipase showed high regioselectivity, producing high yields of the C-3 monodeacetylated product at pH 5.0 and 4 °C. Hybrid catalysts composed of an enzyme and metallic complex are also treated in this Special Issue. The article by Christian Herrero et al. describes the development of the Mn(TpCPP)-Xln10A artificial metalloenzyme, obtained by non-covalent insertion of Mn(III)-meso-tetrakis(p-carboxyphenyl)porphyrin [Mn(TpCPP), 1-Mn] into xylanase 10A from Streptomyces lividans (Xln10A). The complex was found able to catalyze the selective photo-induced oxidation of organic substrates in the presence of [RuII(bpy)3]2+ as a photosensitizer and [CoIII(NH3)5Cl]2+ as a sacrificial electron acceptor, using water as oxygen atom source. The two published reviews describe different subjects with interest in the fields of biocatalysis and mix metallic-biocatalysis, respectively. The review by Anika Scholtissek et al. describes the state-of-the-art regarding ene-reductases from the old yellow enzyme family (OYEs) to catalyze the asymmetric hydrogenation of activated alkenes to produce chiral products with industrial interest. The dependence of OYEs on pyridine nucleotide coenzyme can be avoided by using nicotinamide coenzyme mimetics. In the review, three main classes of OYEs are described and characterized. The review by Yajie Wang and Huimin Zhao highlights some of the recent examples in the past three years that combine transition metal catalysis with enzymatic catalysis. With recent advances in protein engineering, catalyst synthesis, artificial metalloenzymes, and supramolecular assembly, there is great potential to develop more sophisticated tandem chemoenzymatic processes for the synthesis of structurally complex chemicals. In conclusion, these nine publications give an overview of the possibilities of different catalysts, both traditional biocatalysts and hybrids with metals or organometallic complexes to be used in different processes—particularly in synthetic reactions—under very mild reaction conditions.

Recent Advances in Biocatalysis and Metabolic Engineering for Biomanufacturing

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ISBN: 9783039215744 9783039215751 Year: Pages: 278 DOI: 10.3390/books978-3-03921-575-1 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Technology (General) --- Biotechnology
Added to DOAB on : 2019-12-09 11:49:15
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The use of biocatalysts, including enzymes and metabolically engineered cells, has attracted a great deal of attention in the chemical and bio-industry, because biocatalytic reactions can be conducted under environmentally-benign conditions and in more sustainable ways. The catalytic efficiency and chemo-, regio-, and stereo-selectivity of enzymes can be enhanced and modulated using protein engineering. Metabolic engineering seeks to enhance cellular biosynthetic productivity of target metabolites via controlling and redesigning metabolic pathways using multi-omics analysis, genome-scale modeling, metabolic flux control, and reconstruction of novel pathways. The aim of this book is to cover the recent advances in biocatalysis and metabolic engineering for biomanufacturing of biofuels, chemicals, biomaterials, and pharmaceuticals. Reviews and original research articles on the development of new strategies to improve the catalytic efficiency of enzymes, biosynthetic capability of cell factories, and their applications in production of various bioproducts and chemicals are included.

Keywords

artificial self-sufficient P450 --- bioplastics --- dodecanoic acid --- Nylon 12 --- ?-aminododecanoic acid --- immobilization --- fluorescein diacetate --- polyurethane foam --- biofilm --- total enzymatic activity --- biocatalysis --- Combi-CLEAs --- cascade reactions --- immobilization --- Myceliophthora --- glyoxal oxidase --- 5-hydroxymethylfurfural --- aerobic methane bioconversion --- bioreactor --- string film reactor --- mass transfer performance --- cross-linked enzyme aggregate --- amyloglucosidase --- magnetic nanoparticles --- bovine serum albumin --- polyethyleneimine --- starch hydrolysis --- Eversa --- interfacial activation --- lipase immobilization --- enzyme stabilization --- enzyme modulation --- metabolic engineering --- synthetic biology --- 3-hydroxypropionic acid --- microbial production --- fatty acid synthesis --- acetate --- redox enzymes --- FTIR spectroscopy --- small molecules --- Corynebacterium glutamicum --- Pvgb --- tunable expression system --- expression vectors --- synthetic biology --- Vitreoscilla --- vgb --- biocatalysts --- biocatalytic reaction --- Methylosinus sporium strain 5 --- soluble methane monooxygenase --- C–H activation --- O2 activation --- synthetic biology --- metabolic engineering --- microbial cell factory --- synthetic metabolic pathways --- mannose --- magnetic nanoparticles --- immobilization --- whole cell --- specific recognition --- 12-hydroxydodecanoic acid --- dodecanoic acid --- CYP153A --- whole-cell biotransformation --- Candida antarctica Lipase B --- transesterification --- polymer functionalization --- tetraethylene glycol --- poly(ethylene glycol) --- hydrogenase --- bio-hydrogen --- chemicals addition --- review --- (?)-?-bisabolol --- mevalonate (MVA) --- mevalonate kinase 1 --- Methanosarcina mazei --- fed-batch fermentation --- monoterpene --- prokaryotic microbial factory --- metabolic engineering --- MEP pathway --- MEV pathway --- n/a

Novel Membrane Technologies for Traditional Industrial Processes

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ISBN: 9783038977902 9783038977919 Year: Pages: 196 DOI: 10.3390/books978-3-03897-791-9 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Physics (General)
Added to DOAB on : 2019-08-28 11:21:27
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Through reading this book, you will obtain information on: (1) the main problems in air separation and natural gas treatment by membrane separation and how to solve them; (2) processes involving membranes and new membrane materials for the more economical utilization of bio-resources; (3) energy selection and membrane development for more expedient and stable harnessing of the natural osmosis phenomenon; (4) many excellent contributions about catalytic membrane bioreactors; (5) how to fine-tune the arrangement of aquaporins (i.e., proteins identified in biological cells) to achieve superior water treatment efficiency.

Enzyme-Mediated Stereoselective Synthesis

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ISBN: 9783039219360 9783039219377 Year: Pages: 116 DOI: 10.3390/books978-3-03921-937-7 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Chemistry (General) --- Inorganic Chemistry
Added to DOAB on : 2020-01-07 09:08:26
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This book is a collection of studies focused on the exploitation of enzyme stereoselectivity for the synthesis of relevant chemicals, such as innovative materials, chiral building blocks, natural products, and flavor and fragrance compounds. Different catalytic approaches are reported. The first study describes a resolution-based process for the stereoselective synthesis of the enantiomeric forms of the flavor compound linaloyl oxide, whereas other enantiomeric enriched aroma compounds were obtained through a novel microbial approach based on solid-state fermentation. Two relevant works exploit the potential of the biocatalyzed reduction reactions. The first of these contributions describes the enantioselective synthesis of ?-nitroalcohols by enzyme-mediated reduction of ?-nitroketones, whereas a second contribution reports the preparation of chiral 1,4-diaryl-1,4-diols through ADH-catalyzed bioreduction of the corresponding diketones. Concerning enantioenriched alcohol derivatives, natural hydroxy fatty acids are prepared by means of the biocatalytic hydration reaction of natural fatty acids using the probiotic bacterium Lactobacillus rhamnosus as a whole-cell biocatalyst. Further studies describe the use of modified pullulan polysaccharide for lipase immobilization and the recent advances in synthetic applications of ?-transaminases for the production of chiral amines.

Magnetic Nanoparticles

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ISBN: 9783039282685 9783039282692 Year: Pages: 406 DOI: 10.3390/books978-3-03928-269-2 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Technology (General)
Added to DOAB on : 2020-04-07 23:07:08
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The present book covers all research areas related to magnetic nanoparticles, magnetic nanorods, and other magnetic nanospecies, their preparation, characterization, and various applications, specifically emphasizing biomedical applications. The chapters written by the leading experts cover different subareas of the science and technology related to various magnetic nanospecies—providing broad coverage of this multifaceted area and its applications. The different topics addressed in this book will be of great interest to the interdisciplinary community active in the area of nanoscience and nanotechnology. It is hoped that this collection and its various chapters will be important and beneficial for researchers and students working in various areas related to bionanotechnology, materials science, biosensor applications, medicine, and many others. Furthermore, this book is aimed at attracting young scientists and introducing them to this field, in addition to providing newcomers with an enormous collection of literature references.

Keywords

cellulase immobilization --- magnetic nanoparticles --- stability --- functionalized nanoparticles --- green chemistry --- magnetic nanoparticles --- enzyme immobilization --- controlled drug delivery --- supporting materials --- iron oxide nanoclusters --- superparticles --- magnetically responsive photonic crystals --- collective behaviors --- magnetic separation --- bioimaging --- magnetic Janus particles --- (bio)sensing --- static --- self-propelled --- magnetic nanoparticles --- iron oxide --- pharmaceutics --- magnetism --- therapy --- development --- nanotechnology --- magnetic nanoparticles (MNPs) --- cancer biomarkers --- MNPs synthesis --- MNPs functionalization --- sensors --- cancer detection --- cancer treatment --- cancer screening --- magnetic/targeted drug delivery --- optical sensor --- magnetic nanoparticle --- imaging --- surface plasmon resonance --- surface-enhanced Raman spectroscopy --- fluorescence spectroscopy --- near infrared spectroscopy --- extracellular vesicles --- superparamagnetic iron oxide nanoparticles --- magnetic resonance imaging (MRI) --- magnetic nanoparticles --- magnetic nanowires --- magnetic nanotubes --- core-shell composition --- biosensors --- Magnetic bead --- marine toxin --- toxin capture --- toxin detection --- antibody --- aptamer --- immunoassay --- immunosensor --- electrochemical biosensor --- magnetic nanoparticles --- surface functionalization --- immobilization support --- separation probe --- analytical platform --- food safety --- magnetic particles --- sensor --- biomarkers --- cells/cancer cells --- food analytes --- pathogens --- pharmaceuticals --- real sample matrices --- optical --- electrochemical --- surface sensitive methods --- NiCu magnetic nanoparticles --- physical and chemical methods --- surface modification --- biomedicine --- magnetic hyperthermia --- curie temperature --- magnetic hyperthermia --- cancer --- nanoparticles --- magnetic relaxation --- magnetic anisotropy --- heat generation --- multifunctional nanoparticles --- graphene oxide --- photothermal therapy --- magnetic nanoparticle systems --- bio-ferrofluids --- nanomedicine --- single core --- multi-core --- synthesis --- functional coating --- physical-chemical properties --- structural characterization --- magnetorheology --- magnetic nanoparticles --- nanocarriers --- controlled drug delivery --- high-resolution medical imaging --- cancer biomarkers --- circulating cancer cells --- fluorescent probes --- magnetite --- superparamagnetism --- biodetection --- magnetofection --- imaging --- therapy --- tissue engineering --- n/a

Environmental Fate of Emerging Organic Micro-Contaminants

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ISBN: 9783039213672 9783039213689 Year: Pages: 128 DOI: 10.3390/books978-3-03921-368-9 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Environmental Sciences
Added to DOAB on : 2019-12-09 11:49:15
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The toxicity and fate of pharmaceuticals and other emerging micro-organic contaminants in the natural and built environments have been the focus of much research over the last twenty years. Particular focus has recently centred on the fate of antimicrobial chemicals, including antibiotics and antifungals. The occurrence of such chemicals in the environment is thought to contribute to the selection of resistance in exposed microorganisms.This Special Issue (SI) brings together a broad range of recent advances in the field of emerging micro-organic contaminants, ranging from medicinal contaminants to industrial chemicals in the environment. Notably, these range from chemical extraction and large-scale analysis to adverse effects on non-target aquatic organisms and potential risk to humans via contaminated foodstuffs. Additionally, this Special Issue also presents novel contaminant treatment/degradation methods of both physical and biological nature.

Multifunctional Oxide-Based Materials: From Synthesis to Application

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ISBN: 9783039213979 9783039213986 Year: Pages: 202 DOI: 10.3390/books978-3-03921-398-6 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Chemistry (General)
Added to DOAB on : 2019-12-09 11:49:15
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Green Synthesis of Nanomaterials

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ISBN: 9783039217861 9783039217878 Year: Pages: 224 DOI: 10.3390/books978-3-03921-787-8 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Biology --- Microbiology
Added to DOAB on : 2019-12-09 16:10:12
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Nanomaterials possess astonishing physical and chemical properties. They play a key role in the development of novel and effective drugs, catalysts, sensors, and pesticides, to cite just a few examples. Notably, the synthesis of nanomaterials is usually achieved with chemical and physical methods needing the use of extremely toxic chemicals or high-energy inputs. To move towards more eco-friendly processes, researchers have recently focused on so-called “green synthesis”, where microbial, animal-, and plant-borne compounds can be used as cheap reducing and stabilizing agents to fabricate nanomaterials. Green synthesis routes are cheap, environmentally sustainable, and can lead to the fabrication of nano-objects with controlled sizes and shapes—two key features determining their bioactivity.

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