418 results match your criteria naoh urea

Enhanced nail delivery of voriconazole-loaded nanomicelles by thioglycolic acid pretreatment: A study of protein dynamics and disulfide bond rupture.

Int J Pharm 2021 Apr 20;602:120597. Epub 2021 Apr 20.

Laboratory of Nanosystems and Drug Delivery Devices (NanoSYS), School of Pharmacy, Universidade Federal de Goiás (UFG), Rua 240, esq. com 5ª Avenida, Setor Leste Universitário, 74605-170 Goiânia, GO, Brazil. Electronic address:

This work aimed to select an effective penetration enhancer (PE) for nail pretreatment, develop voriconazole (VOR)-loaded nanomicelles, and evaluate their ability to deliver VOR to the nail. A complete analysis of nail protein dynamics, bond rupture, and microstructure was performed. Alternative methods as electron paramagnetic resonance (EPR) and the Ellman's reagent (DTNB) assay were also evaluated. Read More

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Regeneration of PEG slide for multiple rounds of single-molecule measurements.

Biophys J 2021 May 4;120(9):1788-1799. Epub 2021 Mar 4.

Department of Biophysics, Johns Hopkins University, Baltimore, Maryland; Physics Frontier Center (Center for Physics of Living Cells), University of Illinois, Urbana, Illinois. Electronic address:

Single-molecule fluorescence detection of protein and other biomolecules requires a polyethylene glycol (PEG)-passivated surface. Individual channels on a PEG-passivated slide are typically used only a few times, limiting the number of experiments per slide. Here, we report several strategies for regenerating PEG surfaces for multiple rounds of experiments. Read More

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Neutron total scattering investigation on the dissolution mechanism of trehalose in NaOH/urea aqueous solution.

Struct Dyn 2021 Jan 10;8(1):014901. Epub 2021 Feb 10.

Institute for Advanced Study, Shenzhen University, Shenzhen 508060, China.

Trehalose is chosen as a model molecule to investigate the dissolution mechanism of cellulose in NaOH/urea aqueous solution. The combination of neutron total scattering and empirical potential structure refinement yields the most probable all-atom positions in the complex fluid and reveals the cooperative dynamic effects of NaOH, urea, and water molecules in the dissolution process. NaOH directly interacts with glucose rings by breaking the inter- and intra-molecular hydrogen bonding. Read More

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January 2021

Thermo-mechanical properties of pretreated coir fiber and fibrous chips reinforced multilayered composites.

Sci Rep 2021 Feb 11;11(1):3618. Epub 2021 Feb 11.

Simonyi Károly Faculty of Engineering, University of Sopron, Sopron, Hungary.

Coir is one of the most important natural fibers having significant potentiality in structural biocomposites production. The long coir fiber (LCF) and short fibrous chips (CFC) were extracted from the husk of coconut. The dimensions of the CFC were within 1. Read More

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February 2021

Sustainable green strategy for recovery of glucose from end-of-life euro banknotes.

Waste Manag 2021 Mar 4;123:23-32. Epub 2021 Feb 4.

Department of Biochemistry, Vytautas Magnus University, Kaunas, Lithuania.

Usually, Euro banknotes are made from cotton substrates and their waste is disposed of in landfill or is incinerated. In order to valorize the end-of-life euro banknotes (ELEBs), the substrates were used in this research for cellulase production via submerged fungal fermentation (SFF), and the resultant fungal cellulase w s used in ELEBs hydrolysis process for extraction of glucose. The experiments were started by exposing the ELEBs to different types of pretreatments, including milling process, alkali (NaOH/urea solution), and acid leaching to remove any contamination (e. Read More

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Preparation of 6-carboxyl chitin and its effects on cell proliferation in vitro.

Carbohydr Polym 2021 Apr 16;257:117638. Epub 2021 Jan 16.

Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China. Electronic address:

This study concerns the performance evaluation of 6-carboxyl chitin for its wound healing application. 6-Carboxyl chitins were prepared by the oxidation of chitin at C-6 with NaClO/TEMPO/NaBr after α-chitin was pretreated in NaOH/urea solution. The products with different molecular weights were obtained by changing reaction conditions. Read More

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Sustainable cultivation of Navicula incerta using cellulose-based scaffold incorporated with nanoparticles in air-liquid interface cultivation system.

Chemosphere 2021 Jun 18;273:129657. Epub 2021 Jan 18.

School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, Nibong Tebal, Pulau Pinang, 14300, Malaysia. Electronic address:

Microalgae cultivation using open cultivation systems requires large area and it is susceptible to contamination as well as weather changes. Meanwhile, the closed systems require large capital investment, and they are susceptible to the build-up of dissolved oxygen. Air-liquid interface culture systems with low water-footprint, but high packing density can be used for microalgae cultivation if low-cost culture scaffolds are available. Read More

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Silicon oxide-protected nickel nanoparticles as biomass-derived catalysts for urea electro-oxidation.

J Colloid Interface Sci 2021 May 31;589:56-64. Epub 2020 Dec 31.

School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225009, Jiangsu, PR China. Electronic address: https://www.x-mol.com/groups/panghuan.

The urea electro-oxidation reaction (UOR) is explored as a new technique for energy conversion and the removal of urea via electrochemical means in wastewater. Nickel (Ni) nanoparticles grown on nanosheets were prepared by a facile hydrothermal reaction and a subsequent calcination process of silicon oxide/nitrogen-doped carbon (SiO/NC) as the precursor, in which SiO/NC with a natural three-dimensional (3D) interconnected structure was obtained from bamboo leaves. The nickel/silicon oxide/nitrogen-doped carbon (Ni/SiO/NC, denoted as Y) obtained at 900 °C (Y3), exhibits the most optimal catalytic properties for the UOR with a low potential of 1. Read More

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Bifunctional Regenerated Cellulose/Polyaniline/Nanosilver Fibers as a Catalyst/Bactericide for Water Decontamination.

ACS Appl Mater Interfaces 2021 Jan 13;13(3):4410-4418. Epub 2021 Jan 13.

School of Textile Materials and Engineering, Wuyi University, Jiangmen 529020, China.

For antagonizing urgent water pollution and increasing environmental consciousness, the integration of renewable resources and nanotechnologies has become a trend to improve water quality in the ecosystem. Here, we designed a green route to fabricate regenerated cellulose fibers (CFs) with 3D micro- and nanoporous structures in NaOH/urea aqueous solvent systems via a scalable wet-spinning procedure as support materials for nanoparticles (NPs). Modification of CFs with polyaniline@Ag nanocomposites through in situ reduction of the silver ion with aqueous aniline led to enhanced pollutant removal efficiency of functional cellulose-based fibers (FCFs), demonstrating both rapid hydrogenation catalytic performance for the reduction of -nitrophenol and high antibacterial properties for in-flow water purification. Read More

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January 2021

Liquid-Exfoliated Mesostructured Collagen from the Bovine Achilles Tendon as Building Blocks of Collagen Membranes.

ACS Appl Mater Interfaces 2021 Jan 5;13(2):3186-3198. Epub 2021 Jan 5.

Department of Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, United States.

Mesoscaled assemblies are organized in native collagen tissues to achieve remarkable and diverse performance and functions. In this work, a facile, low-cost, and controllable liquid exfoliation method was applied to directly extract these collagen mesostructures from bovine Achilles tendons using a sodium hydroxide (NaOH)/urea aqueous system with freeze-thaw cycles and sonication. A series of collagen fibrils with diameters of 26-230 nm were harvested using this process, and in situ observations under polarizing microscopy (POM) and using molecular dynamics simulations revealed the influence of the NaOH/urea system on the tendon collagen. Read More

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January 2021

Exogenic production of bioactive filamentous biopolymer by monogonant rotifers.

Ecotoxicol Environ Saf 2021 Jan 21;208:111666. Epub 2020 Nov 21.

Department of Psychiatry, Faculty of Medicine, University of Szeged, Vasas Szent Peter u. 1-3, H-6724 Szeged, Hungary.

The chemical ecology of rotifers has been little studied. A yet unknown property is presented within some monogonant rotifers, namely the ability to produce an exogenic filamentous biopolymer, named 'Rotimer'. This rotifer-specific viscoelastic fiber was observed in six different freshwater monogonants (Euchlanis dilatata, Lecane bulla, Lepadella patella, Itura aurita, Colurella adriatica and Trichocerca iernis) in exception of four species. Read More

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January 2021

An innovative method for improving dyeing yield of the cellulosic substrate using additives in NaOH-water eutectic mixture.

Int J Biol Macromol 2021 Feb 29;170:561-571. Epub 2020 Dec 29.

Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran.. Electronic address:

A novel method has been investigated to remove the conventional mercerizing drawbacks in an attempt to reduce sodium hydroxide consumption along with introducing an environmentally friendly feasible method to improve the dyeing and related properties. It was found that a binary and tertiary mixture of urea, thiourea, and sodium hydroxide could potentially fulfill this purpose. Experiments were carried out under different treatment time, temperature, and concentration of each component in the mixture. Read More

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February 2021

Preparation of Alkaline Polyelectrolyte Membrane Based on Quaternary Ammonium Salt-Modified Cellulose and Its Application in Zn-Air Flexible Battery.

Polymers (Basel) 2020 Dec 22;13(1). Epub 2020 Dec 22.

Advanced Materials Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China.

In this study, a type of alkaline solid polyelectrolyte (ASPE) membrane was developed via the introduction of microcrystalline cellulose (MCC) and its modified product (QMCC) into the polyvinyl alcohol (PVA) matrix. In this process, green NaOH/urea-based solvent was used to achieve a good dispersion of MCC in the PVA matrix; meanwhile, the OH groups in the NaOH/urea-based solvent provided an alkaline environment for good ion conductivity. Compared to the MCC-incorporated ASPE, further improved conductivity was achieved when the MCC was modified with quantitative quaternary ammonium salt. Read More

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December 2020

Preparation and characterization of various chitin-glucan complexes derived from white button mushroom using a deep eutectic solvent-based ecofriendly method.

Int J Biol Macromol 2021 Feb 14;169:122-129. Epub 2020 Dec 14.

School of Pharmacy, Sungkyunkwan University, Suwon, Gyeonggi 16419, Republic of Korea. Electronic address:

Deep eutectic solvents (DESs) have gained great interests as ecofriendly and safe solvents in diverse areas. Herein, various chitin-glucan complexes (CGCs) were prepared from white button mushroom (Agaricus bisporus) using DESs. Ultrasonication of mushroom in five DESs yielded two types of CGCs from each DES, one from the DES-insoluble residue (DES_P) and another from the DES-soluble extract (DES_S). Read More

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February 2021

Preparation and characterization of curdlan/nanocellulose blended film and its application to chilled meat preservation.

Chemosphere 2021 Mar 13;266:128948. Epub 2020 Nov 13.

School of Energy and Chemical Engineering, Xiamen University Malaysia, Jalan Sunsuria, Bandar Sunsuria, 43900, Sepang, Selangor Darul Ehsan, Malaysia; College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, China. Electronic address:

In this study, to improve the mechanical and thermal properties of curdlan film, a curdlan/nanocellulose (NC) blended film was prepared and characterized for the first time. NC was successfully prepared from microcrystalline cellulose (MCC) with NaOH/urea treatment. The particle size of NC was observed to be 70-140 nm by cryo-electron microscope (cryo-EM). Read More

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Continuous adsorptive removal of glimepiride using multi-walled carbon nanotubes in fixed-bed column.

Environ Sci Pollut Res Int 2021 Mar 20;28(12):14694-14706. Epub 2020 Nov 20.

Department of Pharmacy, An-Najah National University, P.O. Box 7, Nablus, Palestine.

Water pollution by emerging pollutants such as pharmaceutical and personal care products is one of today's biggest challenges. The presence of these emerging contaminants in water has raised increasing concern due to their frequent appearance and persistence in the aquatic ecosystem and threat to health and safety. The antidiabetic drug glimepiride, GPD, is among these compounds, and it possesses adverse effects on human health if not carefully administered. Read More

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High-strength, blood-compatible, and high-capacity bilirubin adsorbent based on cellulose-assisted high-quality dispersion of carbon nanotubes.

J Chromatogr A 2020 Dec 29;1634:461659. Epub 2020 Oct 29.

Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, No.24 South Section 1, Yihuan Road, Chengdu 610065, PR China. Electronic address:

Excess bilirubin can accumulate in body organs and has serious effects on human health. In this work, a simple engineering strategy, based on cellulose-assisted high-quality dispersion of carbon nanotubes (CNTs), is proposed to produce high-performance bilirubin adsorbents. By dispersing cellulose and CNTs in NaOH/thiourea aqueous solution, a homogeneous and stable cellulose/CNTs solution is achieved. Read More

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December 2020

On the interference of urea with CO/CO chemistry of cellulose model solutions in NaOH(aq).

Carbohydr Polym 2021 Jan 11;251:117059. Epub 2020 Sep 11.

Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden; Wallenberg Wood Science Center, The Royal Institute of Technology, Chalmers University of Technology, SE-100 44, Stockholm, Sweden. Electronic address:

The CO/CO chemistry of the cellulose/NaOH(aq) solutions has been recently reported to comprise a CO incorporation through formation of a transient cellulose carbonate intermediate along with cellulose - CO interactions. This work explores on molecular interactions arising when this chemistry is brought together with urea, the most common stabiliser of these solutions. H, C and steady-state heteronuclear Overhauser effect NMR studies on the cellulose analogues (methyl-β-glucopyranoside (β-MeO-Glcp) and microcrystalline cellulose), combined with pH and ATR-FTIR measurements, reveal concurrent interactions of urea with both CO and CO- leading to increased uptake of CO and a buffering effect. Read More

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January 2021

A two-year incubation study of transformations of crop residues into soil organic matter (SOM) and a procedure for the sequential isolation and the fractionation of components of SOM.

Sci Total Environ 2021 Apr 20;763:143034. Epub 2020 Oct 20.

Embrapa Soils, Rua Jardim Botânico, 1024 CEP 22460-000 Rio de Janeiro, RJ, Brazil.

Maize (Zea mays) stover, with its natural C abundance, was incubated for two years in a gravelly brown earth sandy loam soil that had been under long term cultivation to wheat (Triticum aestivum) for more than 30 years. The relative abundances of C in the maize amendment allowed the contributions of the stover to be traced in the components of soil organic matter (SOM) isolated and fractionated using a sequential exhaustive extraction (SEE) process that gave 16 distinct fractions. These were caracterised using elemental, δC, FTIR, and C NMR analyses. Read More

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From the bottom of an old jar: A fluorometric method for the determination of creatinine in human serum.

Anal Chim Acta 2020 Oct 2;1135:116-122. Epub 2020 Sep 2.

University of Warsaw, Faculty of Chemistry, Pasteura 1, 02-093, Warsaw, Poland.

In this paper we have investigated and optimized a non-enzymatic fluorometric creatinine assay. The method was originally described by Blass in the 90s, but we found that besides the reagents mentioned in the paper, an addition of hydrogen peroxide is required to obtain a fluorescent compound. The excitation and emission maxima of the fluorophore are 405 nm and 475 nm, respectively. Read More

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October 2020

Synergistic Effects of Anaerobic Co-Digestion of Pretreated Corn Stover with Chicken Manure and Its Kinetics.

Appl Biochem Biotechnol 2021 Feb 9;193(2):515-532. Epub 2020 Oct 9.

Biomass Energy Engineering Research Centre, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China.

The pretreatment effects and synergistic effects of anaerobic co-digestion of pretreated corn stover (CS) with chicken manure (CM) were studied. Results showed that the NaOH-HO pretreatment effect on CS was better than urea pretreatment in terms of anaerobic digestion promotion. The highest cumulative methane yield of 332. Read More

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February 2021

Processed false yam seed meals in broiler chicken diets: effects on feed preference and apparent nutrient digestibility.

Trop Anim Health Prod 2020 Nov 18;52(6):3621-3629. Epub 2020 Sep 18.

University of Kassel and Georg-August-Universität Göttingen, Animal Husbandry in the Tropics and Subtropics, Steinstr. 19, 37213, Witzenhausen, Germany.

This study evaluated feed preference and apparent nutrient digestibility of a maize-based diet and modified diets containing treated false yam seed meals (TFYSM). False yam seeds were sun-dried (Un_T), or first soaked in water and treated with one of the following: urea (Urea_T), sodium chloride (NaCl_T), sodium hydroxide (NaOH_T), or potassium hydroxide (KOH_T) and blanched. The TFYSM replaced maize (wt/wt) in experimental diets at 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50%, respectively in a feed preference test (experiment 1). Read More

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November 2020

Probing the structure-holding interactions in cheeses by dissociating agents - A review and an experimental evaluation with emmental cheese.

Curr Res Food Sci 2020 Nov 18;3:201-206. Epub 2020 Jul 18.

Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Rua Diogo Botelho 1327, 4169-005, Porto, Portugal.

Interactions holding protein structure in cheese has been a subject of considerable investigation, with conclusions varying among studies. We present a review on this topic, covering fresh curds, ripened cheeses, and processed cheeses. We discuss the usual chemicals and conditions used to probe different types of interactions. Read More

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November 2020

Molecular Dispersion of Starch as a Crucial Parameter during Size-Exclusion Chromatography.

Foods 2020 Sep 1;9(9). Epub 2020 Sep 1.

Department of Biotechnology and Food Microbiology, Poznań University of Life Sciences, 60-627 Poznań, Poland.

Starch, α-polyglucan consisting of a large number of anhydroglucose units joined by α-1,4- and α-1,6-glycosidic bonds, seems to be characterized by a simple structure when compared to other natural polymers. Nevertheless, starches of various botanical origins have different physicochemical properties that are related to the differences in molecular and supramolecular structure of this polymer. In terms of the functional value of starch, the behavior of its macromolecules in solution is the most important result of its structural features. Read More

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September 2020

Aerogels Based on Reduced Graphene Oxide/Cellulose Composites: Preparation and Vapour Sensing Abilities.

Nanomaterials (Basel) 2020 Aug 31;10(9). Epub 2020 Aug 31.

State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China.

This paper reports on the preparation of cellulose/reduced graphene oxide (rGO) aerogels for use as chemical vapour sensors. Cellulose/rGO composite aerogels were prepared by dissolving cellulose and dispersing graphene oxide (GO) in aqueous NaOH/urea solution, followed by an in-situ reduction of GO to reduced GO (rGO) and lyophilisation. The vapour sensing properties of cellulose/rGO composite aerogels were investigated by measuring the change in electrical resistance during cyclic exposure to vapours with varying solubility parameters, namely water, methanol, ethanol, acetone, toluene, tetrahydrofuran (THF), and chloroform. Read More

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Ultrasound-assisted alkali-urea pre-treatment of Miscanthus × giganteus for enhanced extraction of cellulose fiber.

Carbohydr Polym 2020 Nov 12;247:116758. Epub 2020 Jul 12.

School of Engineering, University of Guelph, Guelph, Ontario, Canada. Electronic address:

Ultrasound-assisted-alkali-urea (UAAU) pre-treatment of miscanthus biomass was investigated for enhanced delignification and extraction of cellulose fiber. The effects of pre-treatment conditions investigated were: sonication time (10.0, 15. Read More

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November 2020

Facilitating microplastic quantification through the introduction of a cellulose dissolution step prior to oxidation: Proof-of-concept and demonstration using diverse samples from the Inner Oslofjord, Norway.

Mar Environ Res 2020 Oct 22;161:105080. Epub 2020 Jul 22.

Norwegian Geotechnical Institute (NGI), P.O. Box 3930 Ullevål Stadion, N-0806, Oslo, Norway; Norwegian University of Science and Technology (NTNU), NO-7491, Trondheim, Norway. Electronic address:

Identifying and quantifying microplastic in marine samples can be facilitated by removing natural organic matter (NOM). Cellulosic material, like chitin, however, are a type of NOM that is resistant to chemical digestion, and difficult to eliminate from samples. To address this, a two-step digestion method was developed to remove or reduce cellulosic materials in diverse marine media. Read More

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October 2020

Modification of Lignocellulosic Materials with a Mixture of -DMDHEU/Choline Chloride to Remove CrO, NO, and HAsO in Aqueous Solution.

ACS Omega 2020 Jul 15;5(29):18313-18320. Epub 2020 Jul 15.

Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT), 268 Ly Thuong Kiet Street, Ward 14, District 10, Ho Chi Minh City 700000, Vietnam.

A new denaturation agent is the mixture of 4,5-dihydroxy-1,3-bis(methoxymethyl)imidazolidin-2-one (-DMDHEU)/choline chloride (CC) introduced to modify three kinds of lignocellulosic materials containing different lignin contents in the following order: cotton used in medicine < sawdust from wood < powder from the coconut shell. The modification process is carried out through two main steps: 0.2 N NaOH solution with 70% v/v ethanol and 30% v/v water was applied to remove lignin and activate the initial raw materials, and then delignified materials were modified with -DMDHEU/CC by using a parched heat supply method after chemical impregnation. Read More

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Evaluation of a novel pretreatment of NaOH/Urea at outdoor cold-winter conditions for enhanced enzymatic conversion and hythane production from rice straw.

Sci Total Environ 2020 Nov 15;744:140900. Epub 2020 Jul 15.

State Key Laboratory of Urban Water Resources and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.

A novel pretreatment using NaOH/Urea (NU) solution at outdoor cold-winter conditions was developed to enhance the enzymatic saccharification and hythane production from rice straw (RS). Results revealed that the reducing sugar conversion of RS reached 90.02% after NU pretreatment at outdoor freezing temperature. Read More

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November 2020

A novel integrated process to convert cellulose and hemicellulose in rice straw to biobutanol.

Environ Res 2020 07 28;186:109580. Epub 2020 Apr 28.

State Key Laboratory of Urban Water Resources and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China. Electronic address:

A novel integrated process was established in this study to produce butanol from rice straw. In the first pretreatment, an alternative NaOH/Urea preatment operated at -12 C efficiently removed 10.9 g lignin and preserved 91. Read More

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