Article
Polymer Science
Xu Chen, Changzhu Lv, Yahui Li, Zishuo Wu, Renkuan Cao, Weihang Fei, Jin Lv, Wei Chen
Summary: The complicated chemical structure and acetalization mechanism of poly(vinyl butyral) (PVB) were revealed using multidimensional NMR with 13C labeling. Isotope enrichment helped determine the sequence distribution of vinyl butyral (VB) and vinyl alcohol (VA) monomers in the PVB backbone, while NMR experiments identified primary, secondary, and tertiary carbons. Various 2D-NMR experiments established coupling through chemical bond or space correlation. The resolved information from 1H and 13C NMR spectra provided insights into the acetalization reaction mechanism.
Article
Biochemistry & Molecular Biology
Elianta Kora, Panagiotis C. Tsaousis, Konstantinos S. Andrikopoulos, Christos T. Chasapis, George A. Voyiatzis, Ioanna Ntaikou, Gerasimos Lyberatos
Summary: In this study, a mixed microbial culture (MMC) of polyhydroxyalkanoates (PHAs) producers was developed under nutrient stress for the production of PHAs from fermented discarded fruit juices (DFJ). The efficiency of PHAs production was optimized by altering various factors, and different fermentation mixtures of acidified DFJ were assessed as substrates. The properties of the recovered PHAs were analyzed, showing their potential as bio-based and biodegradable plastics for a circular economy.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2023)
Article
Polymer Science
Neha Tiwari, Manohar Virupax Badiger, Pattuparambil Ramanpillai Rajamohanan, Sapna Ravindranathan
Summary: A reversible sol-gel transition was achieved by grafting a block copolymer onto poly(acrylic acid), and the influence of various physicochemical parameters on thermoresponsive behavior was investigated. The mechanism and structural changes during thermally induced gelation were analyzed using NMR and rheology studies.
POLYMER INTERNATIONAL
(2022)
Article
Neurosciences
Claire Kelly, Thijs Dhollander, Ian H. Harding, Wasim Khan, Richard Beare, Jeanie L. Y. Cheong, Lex W. Doyle, Marc Seal, Deanne K. Thompson, Terrie E. Inder, Peter J. Anderson
Summary: The microstructure and free-water content of the brain in children born very preterm are associated with adverse neurodevelopmental outcomes, and these changes can persist up to thirteen years of age.
Article
Chemistry, Analytical
Taylor F. Nelson, Collin P. Ward
Summary: This study develops a diffusion-ordered spectroscopy (DOSY) method for determining the molecular weight (MW) of polymers, specifically focusing on consumer plastics. The DOSY method demonstrates high-throughput, accurate, and precise measures of polymer MW, as well as the ability to track the evolution of polymer MW during environmental degradation processes. The study also compares DOSY with gel permeation chromatography (GPC) and discusses future developments and potential applications of DOSY.
ANALYTICAL CHEMISTRY
(2023)
Article
Multidisciplinary Sciences
Jonathan Gropp, Qusheng Jin, Itay Halevy
Summary: This paper develops a metabolic-isotopic model of methanogenesis and explains multiple isotopic patterns in laboratory and natural settings. It also provides predictions for the biomass-specific methanogenesis rates.
Article
Mining & Mineral Processing
He Li, Wuche Liu, Jiexin Lu, Yi Lu, Shiliang Shi, Zheng Wang, Qing Ye, Zhenzhen Jia
Summary: Microwave heating can facilitate coal fracturing and gas desorption, but it has issues such as low penetration depth, local overheating, and fracture closure. Acid treatment of coal has advantages in unblocking and permeability improvement, but it struggles to enter microcracks. Microwave-assisted acidification may provide an alternative solution.
INTERNATIONAL JOURNAL OF MINING SCIENCE AND TECHNOLOGY
(2023)
Article
Chemistry, Applied
Takahiro Ohkubo, Akio Yamazaki, Yuta Fukatsu, Yukio Tachi
Summary: This study investigated pore distributions in water-saturated Ca-montmorillonite under various dry densities and porewater salinity conditions using H-1 nuclear magnetic resonance measurements. It was found that density is the main factor affecting pore distribution in compacted Ca and Na-montmorillonite, while the effect of porewater salinity and interlayer cations is relatively smaller. The established method based on NMR relaxometry is expected to provide structural parameters for realistic modeling of mass transport in water-saturated compacted clay.
MICROPOROUS AND MESOPOROUS MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Fan Fang, Qifeng Jiang, Rebekka S. Klausen
Summary: This study reports the influence of skeletal connectivity on the conformation-dependent optical properties of cyclosilane homo- and copolymers. The connectivity of cyclosilanes affects their conformation and absorption spectra, and computational studies reveal the role of skeletal connectivity in controlling the optoelectronic properties.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Agriculture, Multidisciplinary
Paola Bambina, Alberto Spinella, Giuseppe Lo Papa, Delia Francesca Chillura Martino, Paolo Lo Meo, Onofrio Corona, Luciano Cinquanta, Pellegrino Conte
Summary: The soil effect on the micro-component composition of Nero d'Avola wines obtained from different locations was investigated using 1H NMR-based metabolomics. The study found that the differences among wines were not only due to the concentrations of various analytes but also to the characteristics of the H-bond network. Furthermore, the H-bond network was found to be related to the soil properties.
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Jiwon Kim, Uyen Thi Do, Joo Won Kim, Donghyuk Jo, Quy Son Luu, Jihye Jung, Youngbok Lee
Summary: This study introduces a robust synthetic method for fabricating biodegradable microcapsules composed mainly of natural sugar polymers, evaluating their initial biodegradation processes using an enzymatic method. The results show that the enzymatic breakdown of ester bonds in the microcapsules leads to the destruction of their structures. Furthermore, sorbitol molecules are released from the microcapsules, supporting their biodegradation properties.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2021)
Article
Engineering, Environmental
Ana Silva, Raquel V. Barrulas, Marta C. Corvo, Marcileia Zanatta
Summary: Ionic liquids and poly(ionic liquid)s are promising materials for CO2 capture, but their industrial application has been delayed due to economic and technical issues. This study focuses on the synthesis and characterization of imidazolium and pyrrolidinium-derived ILs and PILs with basic anions, and evaluates their CO2 sorption capacity. The results show great potential for CO2 capture and recycling.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Chemistry, Applied
Yicong Li, Shuangxi Fan, Anjun Li, Guoying Liu, Wei Lu, Bo Yang, Fengxian Wang, Xin Zhang, Xiaojuan Gao, Zhiyuan Lu, Ning Su, Guanghao Wang, Yinuo Liu, Xin Ji, Peng Xin, Guohui Li, Daobing Wang, Fuping Lu, Qiding Zhong
Summary: This study utilized NMR and GC analysis combined with multivariate statistical analysis to establish a model for validating the vintage authenticity of Chinese Baijiu, providing important evidence for distinguishing actual storage vintages.
Article
Biochemical Research Methods
Rosachiara A. Salvino, Christie Aroulanda, Giovanni De Filpo, Giorgio Celebre, Giuseppina De Luca
Summary: In this study, the metabolic composition of pure bergamot essential oil (BEO) was investigated using NMR spectroscopy. The results showed that NMR technique is capable of quantifying the main components of BEO and detecting potential adulteration with cheaper oils. This research has significant implications in the quality control of BEO.
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Svenja Wesp, Kai Wolf, Stefan Immel, Michael Reggelin
Summary: Lyotropic liquid crystalline (LLC) phases of amino acid derived polyarylisocyanides were used as chiral alignment media for measuring residual dipolar couplings (RDCs) of small chiral organic molecules. The LLC phases exhibited excellent orienting properties for a wide range of analytes with different functional groups, allowing for accurate extraction of RDCs within the range of +/- 40 Hertz. Additionally, the chiral environment had a significant differential order effect on ketones and alcohols.
Article
Chemistry, Applied
J. E. Castanheiro, J. Vital, I. M. Fonseca, A. M. Ramos
Summary: The acetalization of glycerol with hexanal was studied using sulfonic acid-functionalized mesoporous silica, showing optimal activity when the amount of sulfonic acid groups was moderate. Activity increased with the number of sulfonic acid groups until reaching a maximum, after which a decrease was observed. The catalytic stability of the [SO3H](3)-SBA-15 catalyst was evaluated through consecutive batch runs, demonstrating good stability.
Article
Polymer Science
Silvia Baptista, Cristiana A. V. Torres, Chantal Sevrin, Christian Grandfils, Maria A. M. Reis, Filomena Freitas
Summary: In this study, membrane-based methods were evaluated for the recovery of fucose-rich exopolysaccharide (EPS) secreted by Enterobacter A47. The optimized method showed a reduction in water consumption and extraction time, and an increase in product recovery and purity. The changes also improved the emulsion-forming capacity and rheological properties of the biopolymer, which are important for its application in cosmetics, pharmaceuticals, and food products.
Article
Green & Sustainable Science & Technology
Joao M. Carvalho, Bruno C. Marreiros, Maria A. M. Reis
Summary: This study investigated the production of PHA by mixed microbial cultures under high salt concentration and found that high HV content PHA can be produced under these conditions.
Article
Microbiology
Juliana R. Almeida, Joana C. Fradinho, Gilda Carvalho, Adrian Oehmen, Maria A. M. Reis
Summary: This work evaluates the influence of different operational conditions on the bacterial communities reported in phototrophic mixed culture (PMC) systems with polyhydroxyalkanoates (PHA) production capabilities. Chromatiaceae members were identified as the main phototrophic PHA producers, favored under high carbon concentrations and the permanent feast regime. Increasing the organic loading rate in systems fed with fermented wastewater enriched for other bacteria responsible for PHA storage. High-sugar feedstock impaired PHA production under the permanent feast conditions, but not under feast and famine conditions.
Article
Biology
Ines Farinha, Silvia Baptista, Maria A. M. Reis, Filomena Freitas
Summary: This study evaluated the impact of dissolved oxygen levels on the production of polysaccharides and mannans in P. pastoris. The results showed that decreasing the dissolved oxygen level improved substrate conversion into biomass and increased the productivity of polysaccharides and mannans.
Article
Polymer Science
Catia Gil, Ana Teresa Rebocho, Asiyah Esmail, Chantal Sevrin, Christian Grandfils, Cristiana A. Torres, Maria A. M. Reis, Filomena Freitas
Summary: Biosurfactants synthesized by microorganisms are safe and sustainable alternatives to synthetic surfactants. This study characterizes a biopolymer secreted by Burkholderia thailandensis, highlighting its potential as a biosurfactant. The biopolymer is a glycolipopeptide with carbohydrate and protein contents of 33.1% and 23.0%, respectively. It displays good emulsion-stabilizing capacity and can form stable emulsions with hydrophobic compounds.
Article
Polymer Science
Ana Marta Rodrigues, Rita Dias Guardao Franca, Madalena Dionisio, Chantal Sevrin, Christian Grandfils, Maria A. M. Reis, Nidia Dana Lourenco
Summary: Polyhydroxyalkanoates (PHA) are potential substitutes for conventional oil-based plastics, but high production costs are a limiting factor. This study investigated the extraction of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) using sodium hydroxide or sodium hypochlorite as digestion agents. The optimized conditions resulted in high purity and recovery rates for PHA.
Article
Energy & Fuels
J. E. Castanheiro, P. A. Moura, I. Cansado, J. Vital, I. M. Fonseca, A. M. Ramos
Summary: The study found that phosphotungstic acid encapsulated on NaY catalysts could effectively catalyze the reaction between glycerol and cinnamaldehyde at 100℃, and the activity increased with an increasing amount of phosphotungstic acid. The NaY-PW4 material showed the highest conversion rate and catalytic stability.
CHEMICAL ENGINEERING AND PROCESSING-PROCESS INTENSIFICATION
(2022)
Article
Biochemistry & Molecular Biology
Porkodi Kadhirvel, Manuel Azenha, Galya Ivanova, Carlos Pereira, Antonio F. Silva
Summary: A novel, straightforward, and environmentally friendly direct coupling procedure to immobilize carbohydrates on solid supports is presented. The study demonstrates the adjustability of surface load and the integrity of the cyclic conformation of the linked sugar unit using this method.
JOURNAL OF CARBOHYDRATE CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Hileia K. S. Souza, Mariana Matos, Maria A. M. Reis, Jose A. Covas, Loic Hilliou
Summary: Wet biomass mastication before solvent extraction can improve the purity and thermal stability of PHA, as well as its melt rheology, thus recovering the viscoelasticity of PHA extracted from dried biomass.
Article
Biochemistry & Molecular Biology
Sara S. Felix, Douglas V. Laurents, Javier Oroz, Eurico J. Cabrita
Summary: This study investigates the effect of metabolites on full-length (FL) FUS liquid-liquid phase separation (LLPS) and explores the behavior of the folded domains. It is found that FL FUS LLPS is maximal at low concentrations of glucose and glutamate, moderate concentrations of NaCl, Zn2+, and Ca2+, and at the isoelectric pH. The FUS RNA recognition motif (RRM) and zinc-finger (ZnF) domains undergo cold denaturation, exposing buried nonpolar residues that can participate in LLPS-promoting hydrophobic interactions.
Article
Chemistry, Multidisciplinary
Tiago Santos, Micael Silva, Lionel Imbert, Maria P. C. Campello, Antonio Paulo, Samir Amrane, Gilmar F. F. Salgado, Carla Cruz, Eurico J. J. Cabrita
Summary: The interaction between the G-quadruplex (G4) motif in precursor miRNA 149 (rG4) and the G4 ligand stabilizer C-8, as well as the protein nucleolin, was studied using Nuclear Magnetic Resonance (NMR) spectroscopy. The results showed a strong stabilizing interaction between the C-8 ligand and the rG4 structure. Different interaction patterns were observed between nucleolin and rG4, as well as nucleolin and rG4/C-8 complex. However, the location of binding between nucleolin and rG4 or rG4/C-8 complex was found to be the same. This study provides a new framework for investigating rG4/ligand/nucleolin complexes that may impact the biogenesis of miRNA 149.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Eliana C. Guarda, Eunice Costa, Catia Gil, Catarina L. Amorim, Claudia F. Galinha, Anouk F. Duque, Paula M. L. Castro, Maria A. M. Reis
Summary: Traditional tools for controlling and monitoring biological systems are often offline and time-consuming, leading to ineffective and delayed responses. This study evaluated the feasibility of using two-dimensional fluorescence spectroscopy as a real-time and non-destructive procedure to monitor acidogenic fermentation in a granular sludge reactor. The results showed that fluorescence spectroscopy combined with mathematical analysis could accurately predict fermentation products and soluble protein concentrations in the effluent.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Biochemistry & Molecular Biology
Kayo Santana Barros, Monica Carvalheira, Bruno Costa Marreiros, Maria Ascensao M. Reis, Joao Goulao Crespo, Valentin Perez-Herranz, Svetlozar Velizarov
Summary: For the production of polyhydroxyalkanoates (PHA) using nitrogen-rich feedstocks, the typical strategy of restricting cell growth by nitrogen limitation is not applicable. In this study, Donnan dialysis was evaluated as an alternative method to remove excess nitrogen ions by separating ammonium ions from volatile fatty acids in the media. The use of Fumasep and Ralex membranes showed better performance in terms of ammonium extraction compared to Ionsep.
Article
Biotechnology & Applied Microbiology
Andre Oliveira, Silvia Petronilho, Luisa S. Serafim
Summary: This study explores the use of food industry waste and wastewater for acidogenic fermentation to produce non-competing food carbohydrates and mixed microbial cultures (MMCs), aiming to produce short-chain organic acids (SCOAs) for polyhydroxyalkanoates (PHAs) production. The results show that spent frying oil (SFO) can be used as a substrate for SCOA production via MMCs, with the highest SCOA concentration and diverse SCOAs profile achieved using MMCs collected from an aerobic tank of a municipal wastewater treatment plant at a specific F/M ratio. The odd and even SCOAs produced have potential applications in PHAs production.
FERMENTATION-BASEL
(2023)
