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1.
Chemosphere ; 263: 128038, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33297055

RESUMO

Zinc (Zn2+) and cadmium (Cd2+) in water pose serious threats to human health and the environment. In search for a more effective treatment technology, we prepared a type of carboxymethyl cellulose (CMC) bridged chlorapatite (CMC-CAP) nanoparticles and tested the material for removal of Zn2+ and Cd2+ from water. CMC macromolecules were attached to CAP by bidentate bridging and hydrogen bonding, preserving the high adsorption capacity of CAP nanoparticles while allowing for easy gravity-separation of the nanoparticles. CMC-CAP showed rapid adsorption kinetics and 22.8% and 11.2% higher equilibrium uptake for Zn2+ and Cd2+, respectively, than pristine CAP. An extended dual-mode isotherm model, which takes into account both sorption and chemical precipitation, provided the best fits to the sorption isotherms, giving a maximum Langmuir sorption capacity of 141.1 mg g-1 for Zn2+ and 150.2 mg g-1 for Cd2+ by CMC-CAP. Na+ at up to 5 mM showed modest effects on the uptake of the heavy metals, while 2-5 mM of Ca2+ exerted notable inhibitive effects. Dissolved organic matter (up to 5 mg L-1 as TOC) inhibited the Zn2+ uptake by 16.5% but enhanced the Cd2+ removal by 8.6%. Material characterizations and surface binding analyses revealed that ion exchange, surface precipitation, and surface complexation were the removal mechanisms for the heavy metals. This study demonstrates stabilizer bridging may serve as a convenient strategy to facilitate water treatment uses of nanoparticles.


Assuntos
Metais Pesados , Nanopartículas , Poluentes Químicos da Água , Purificação da Água , Adsorção , Apatitas , Cádmio/análise , Carboximetilcelulose Sódica , Humanos , Água , Poluentes Químicos da Água/análise , Zinco/análise
2.
Bioresour Technol ; 320(Pt B): 124373, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33190094

RESUMO

A novel multiple active sites sponge was fabricated from carboxymethyl cellulose (CMC) and genipin crosslinked carboxyalkyl-chitosan (GCC) combined with sulfonated graphene oxide (CMC/SGO-GCC) and used as a material for adsorbing sulfonamide antibiotics. The GO contains a variety of carboxyl and hydroxyl groups, which can interact with the hydroxyl groups of chitosan and CMC to form strong hydrogen bonds. This adsorption process is spontaneous and pH dependent, and shows high sulfamethoxazole (SMX) and sulfapyridine (SPD). Removal efficiency from aqueous solutions. Equilibrium adsorption studies showed that the maximum adsorption capacities of SMX and SPD decreased from 312.28 to 272.83 mg/g and 161.89 to 146.56 mg/g, respectively, as the temperature increased from 298 to 318 K. Reusability experiments indicated that CMC/SGO-GCC maintained a high adsorption capacity for SMX and SPD upon its reuse. This study shows that CMC/SGO-GCC is an ideal material for adsorbing SMX and SPD.


Assuntos
Quitosana , Grafite , Poluentes Químicos da Água , Adsorção , Carboximetilcelulose Sódica , Concentração de Íons de Hidrogênio , Sulfonamidas , Poluentes Químicos da Água/análise
3.
Chemosphere ; 262: 127733, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32763574

RESUMO

In this study, carboxymethyl cellulose (CMC) was employed to stabilize zero-valent iron nanoparticles (CMC-nFe0) to improve their dispersity and antioxidation for enhanced hexavalent chromium (Cr(VI)) removal. Scanning electron microscope (SEM) observation revealed that the nFe0 agglomerated in clusters, while the CMC-nFe0 connected as chains and presented higher dispersity. Therefore, compared with 54% of the nFe0, the Cr(VI) removal rate of the CMC-nFe0 increased by 0.8 time, reaching 97%. Besides, the nFe0 precipitated in 1 d and was obviously oxidized within 7 d under anoxic condition, leading to a rapid decease of Cr(VI) removal efficiency from 54% to 3% in 56 d. In contrast, the CMC-nFe0 showed no obvious subsidence and oxidized phenomenon within 14 d, which retained a relatively high Cr(VI) removal efficiency of 63% in 56 d, contributing to effective blockage of dissolved oxygen infiltrating from solution to nFe0 particles in presence of CMC. After reaction, the valence state distribution of Cr between solution and material surface indicated that Cr(VI) reduction was dominant comparing to physical adsorption to particles in the remediation process conducted by CMC-nFe0. In addition, lower initial pH and higher iron dosage facilitated Cr(VI) removal. Those results indicated that the dispersive and antioxidative characteristics of CMC-nFe0 were significantly superior to those of nFe0, and CMC stabilization thereafter can be a promising method to promote Cr(VI) elimination by nFe0.


Assuntos
Antioxidantes/química , Cromo/isolamento & purificação , Ferro/química , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Carboximetilcelulose Sódica/química , Cromo/química , Concentração de Íons de Hidrogênio , Nanopartículas Metálicas/química , Microscopia Eletrônica de Varredura , Oxirredução , Oxigênio , Poluentes Químicos da Água/química
4.
Food Chem ; 340: 127950, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32896780

RESUMO

This study aimed to prepare anthocyanin-rich microcapsules by spray and freeze-drying complex coacervated double emulsion using gelatin-acacia gum (GE-AG) and chitosan-carboxymethylcellulose (CS-CMC) and to investigate their properties and in vitro release kinetics. Microencapsulation efficiency (MEE) of the microcapsules varied from 84.9% to 94.7%. CS-CMS microcapsules showed significantly higher MEEs than those of GE-AG microcapsules. A significant higher MEE and lower moisture content and hygroscopicity was observed in spray-dried double emulsion (SDE) microcapsules. Freeze-dried double emulsion (FDE) microcapsules possessed higher total anthocyanin and total phenolic contents. The best fit for release kinetics was achieved using first-order and Higuchi models for SDE and FDE microcapsules, respectively. Diffusion-controlled release in the simulated gastric fluid was found for SDE microcapsules, while erosion-controlled release in simulated gastric and intestinal fluids predominated for FDE microcapsules. These findings suggest that the microcapsules can be applied for loading anthocyanins as a nutraceutical with controllable release requirement.


Assuntos
Antocianinas/química , Cápsulas , Carboximetilcelulose Sódica/química , Quitosana/química , Liberação Controlada de Fármacos , Emulsões , Liofilização , Goma Arábica/química , Cinética , Fenóis/química
5.
Eye Contact Lens ; 46(6): e66-e68, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33044373

RESUMO

We report a rare case of dematiaceous fungus colonization in the therapeutic bandage contact lens (BCL), in an eye with peripheral ulcerative keratitis. Bandage contact lens removal and appropriate treatment resulted in improvement of the visual acuity and prevented the spread of fungus to the underlying ocular structures. Microbiological evaluation of the BCL showed dematiaceous fungal filaments, and the fungus was identified as Bipolaris species. In patients with pigmented plaque-like lesions, with BCL in situ, dematiaceous fungus on the undersurface of the BCL should be kept in mind. Patient education regarding the importance of frequent BCL replacement, proper ocular hygiene, and timely follow-up should be emphasized.


Assuntos
Ascomicetos/isolamento & purificação , Betacoronavirus , Lentes de Contato/microbiologia , Úlcera da Córnea/microbiologia , Infecções por Coronavirus/epidemiologia , Infecções Oculares Fúngicas/microbiologia , Micoses/microbiologia , Pneumonia Viral/epidemiologia , Idoso , Antifúngicos/uso terapêutico , Bandagens , Carboximetilcelulose Sódica/uso terapêutico , Úlcera da Córnea/diagnóstico , Úlcera da Córnea/tratamento farmacológico , Infecções Oculares Fúngicas/diagnóstico , Infecções Oculares Fúngicas/tratamento farmacológico , Humanos , Perda de Seguimento , Masculino , Micoses/diagnóstico , Micoses/tratamento farmacológico , Natamicina/uso terapêutico , Pandemias , Tomografia de Coerência Óptica , Acuidade Visual
6.
Chemosphere ; 261: 128123, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33113646

RESUMO

A pot experiment was carried out to evaluate the efficiency of six types of non-stabilised and Na-carboxymethylcellulose (CMC)-stabilised iron oxide nanoparticles (α-FeOOH, α-Fe2O3, and Fe3O4) on the immobilisation of cobalt (Co) in a soil spiked with different concentrations of it (5, 25, 65, 125, 185 mg kg-1). Amendments were added to soil samples at the rate of 0.5%, and the samples incubated for 60-days. The addition of amendments significantly decreased the concentrations of DTPA-Co and MgCl2-Co, compared with the unamended control. The highest decrease in concentration of DTPA-Co and MgCl2-Co was obtained by the application of CMC-stabilised Fe3O4 (MC) when the concentration of soil total Co was low (5 and 25 mg kg-1) and by the use of CMC-stabilised α-FeOOH (GC) when the concentration of soil total Co was high (65, 125, and 185 mg kg-1), as compared to the control. CMC-stabilised iron oxide nanoparticles were more effective than non-stabilised nanoparticles in the immobilisation of Co. To investigate the effectiveness of iron oxide amendments on the chemical species of Co in the soil spiked with 65 mg kg-1 of this metal, sequential extraction was performed. The concentration of EXCH (exchangeable) and CARB (carbonate) bound fractions decreased significantly after treatment by different amendments. In particular, GC reduced the concentration of EXCH and CARB bound fractions by 20.87, and 17.52%, respectively, compared with the control. Also amendments significantly increased the concentration of FeMn-OX (Fe-Mn oxides), and OM (organic matter) bound, and RES (residual) fractions.


Assuntos
Carboximetilcelulose Sódica/química , Cobalto/análise , Recuperação e Remediação Ambiental/métodos , Compostos Férricos/química , Nanopartículas/química , Poluentes do Solo/análise , Solo/química
7.
PLoS One ; 15(9): e0238284, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32966294

RESUMO

PURPOSE: Restricted shoulder mobility is a major upper extremity dysfunction associated with lower quality of life and disability after breast cancer surgery. We hypothesized that a poloxamer and sodium alginate mixture (Guardix-SG®) applied after axillary lymph node dissection (ALND) would significantly improve shoulder range of motion (ROM) in patients with breast cancer. METHODS: We conducted a double-blind, randomized, prospective study to evaluate the clinical efficacy and safety of Guardix-SG® for the prevention of upper extremity dysfunction after ALND. The primary outcome measure was shoulder ROM at baseline (T0) and 3 (T1), 6 (T2), and 12 months (T3) after surgery. Secondary outcome measures were the Disabilities of the Arm, Shoulder, and Hand score(DASH), pain associated with movement, which was assessed using a numeric rating scale, and lymphedema assessed using body composition analyzer. RESULTS: A total of 83 women with breast cancer were randomly assigned to either the Guardix-SG® group or the control group. In the Guardix-SG® group (n = 37), Guardix-SG® was applied to the axillary region after ALND. In the control group (n = 46), ALND was performed without using Guardix-SG®. Comparing ROM for shoulder flexion before surgery (178.2°) and 12 months after surgery (172.3°), that was restored 12 months after surgery in the Guardix-SG® group, and there was no statistically significant difference between that at before surgery and 12 months after surgery (p = 0.182). No adverse effect was observed in either group. CONCLUSIONS: The results of this study have shown that Guardix-SG® help improve shoulder ROM without causing adverse effects in patients who underwent breast cancer surgery. However, there was no statistically significant difference from the control group. A further large-scale study is needed to obtain a more conclusive conclusion. TRIAL REGISTRATION: CRISKCT0003386; https://cris.nih.go.kr (20181207).


Assuntos
Neoplasias da Mama/cirurgia , Carboximetilcelulose Sódica/administração & dosagem , Ácido Hialurônico/administração & dosagem , Excisão de Linfonodo/efeitos adversos , Mastectomia/efeitos adversos , Poloxâmero/administração & dosagem , Amplitude de Movimento Articular/efeitos dos fármacos , Ombro/patologia , Axila , Neoplasias da Mama/patologia , Estudos de Casos e Controles , Método Duplo-Cego , Combinação de Medicamentos , Feminino , Seguimentos , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Projetos Piloto , Prognóstico , Estudos Prospectivos , Tensoativos/administração & dosagem
8.
Artigo em Inglês | MEDLINE | ID: mdl-32825647

RESUMO

A novel composite of montmorillonite-supported carboxymethyl cellulose-stabilized nanoscale iron sulfide (CMC@MMT-FeS), prepared using the co-precipitation method, was applied to remediate hexavalent chromium (Cr(VI))-contaminated soil. Cr(VI)-removal capacity increased with increasing FeS-particle loading. We tested the efficacy of CMC@MMT-FeS at three concentrations of FeS: 0.2, 0.5, and 1 mmol/g, hereafter referred to as 0.2 CMC@MMT-FeS, 0.5 CMC@MMT-FeS, and 1.0 CMC@MMT-FeS, respectively. The soil Cr(VI) concentration decreased by 90.7% (from an initial concentration of 424.6 mg/kg to 39.4 mg/kg) after 30 days, following addition of 5% (composite-soil mass proportion) 1.0 CMC@MMT-FeS. When 2% 0.5 CMC@MMT-FeS was added to Cr(VI)-contaminated soil, the Cr(VI) removal efficiency, as measured in the leaching solution using the toxicity characteristic leaching procedure, was 90.3%, meeting the environmental protection standard for hazardous waste (5 mg/kg). The European Community Bureau of Reference (BCR) test confirmed that the main Cr fractions in the soil samples changed from acid-exchangeable fractions to oxidable fractions and residual fractions after 30 days of soil remediation by the composite. Moreover, the main complex formed during remediation was Fe(III)-Cr(III), based on BCR and X-ray photoelectron spectroscopy analyses. Biotoxicity of the remediated soils, using Vicia faba and Eisenia foetida, was analyzed and evaluated. Our results indicate that CMC@MMT-FeS effectively immobilizes Cr(VI), with widespread potential application in Cr(VI)-contaminated soil remediation.


Assuntos
Cromo , Recuperação e Remediação Ambiental , Poluentes do Solo , Bentonita , Carboximetilcelulose Sódica , Cromo/análise , Cromo/química , Compostos Férricos , Compostos Ferrosos , Imobilização , Solo , Poluentes do Solo/análise
9.
J Environ Manage ; 276: 111245, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32862116

RESUMO

Chromium (Cr) contamination poses serious threats to the environment and human health. Thus, batch and column experiments were performed to investigate hexavalent chromium [Cr (VI)] removal from solution and porous media using nanoscale zerovalent iron nanoparticles (NZVI) stabilized by sodium carboxymethyl cellulose (CMC). Batch experiments indicated that the mass ratio of Fe/CMC = 1, the presence of 150-200 mg L-1 CMC and lower ionic strength led to optimum Cr (VI) removal in aqueous solution. Column experiments demonstrated that Cr (VI) removal was enhanced with decreasing solution pH and increasing CMC-NZVI concentration. The presence of CMC can increase Cr (VI) removal by NZVI in both aqueous solution and porous media by complexation precipitation of Cr (VI) compounds and better dispersion of NZVI. X-ray photoelectron spectroscopy (XPS) analysis revealed that an appropriate amount of CMC supported the redox reaction of Cr (VI) and NZVI. The removal of Cr (VI) through columns was 20.8% and 88.5% under no additional CMC and optimized CMC content, respectively. However, Cr (VI) removal decreased to 64.6% under excessive CMC content. The CMC modified NZVI nanoparticles were characterized by XRD, XPS and TEM techniques. These findings imply that CMC can be used as an effective stabilizer on NZVI which can in turn be applied for the efficient removal of Cr (VI) from industrial wastewater and groundwater.


Assuntos
Água Subterrânea , Nanopartículas , Poluentes Químicos da Água , Adsorção , Carboximetilcelulose Sódica , Cromo/análise , Ferro , Sódio , Poluentes Químicos da Água/análise
10.
Environ Sci Pollut Res Int ; 27(35): 44089-44105, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32761344

RESUMO

Carboxymethyl cellulose/poly(acrylic acid) (CMC-cl-pAA) hydrogel and its magnetic hydrogel nanocomposite (CMC-cl-pAA/Fe3O4-C30B) were prepared via a free radical polymerization method and used as adsorbents for adsorption of methylene blue (MB) dye. The samples were characterized using Fourier transform infrared, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy coupled with energy-dispersive X-ray spectrometer, high-resolution transmission electron microscope, and dynamic mechanical analysis. The adsorption performance of the prepared adsorbents was studied in a batch mode. Adsorption kinetics and isotherm models were applied in the experimental data to evaluate the nature as well as the mechanism of adsorption processes. It was deduced that the adsorption followed the pseudo-second-order rate equation and Langmuir isotherm models. The maximum adsorption capacities were found to be 1109.55 and 1081.60 mg/g for CMC-cl-pAA hydrogel and CMC-cl-pAA/Fe3O4-C30B hydrogel nanocomposite, respectively. The adsorption thermodynamic studies suggested that the adsorption process was spontaneous and endothermic for CMC-cl-pAA/Fe3O4-C30B hydrogel nanocomposite. The homogeneous dispersion of the Fe3O4-C30B nanocomposite in the CMC-cl-pAA hydrogel significantly improved the thermal stability, mechanical strength, and excellent regeneration stability. This study demonstrates the application potential of the fascinating properties of CMC-cl-pAA/Fe3O4-C30B hydrogel nanocomposite as a highly efficient adsorbent in the removal of organic dyes from aqueous solution.


Assuntos
Nanocompostos , Poluentes Químicos da Água , Purificação da Água , Acrilatos , Adsorção , Carboximetilcelulose Sódica , Argila , Hidrogéis , Cinética , Fenômenos Magnéticos , Azul de Metileno
11.
AAPS PharmSciTech ; 21(6): 213, 2020 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-32737624

RESUMO

The acceptability and palatability of a dosage form are extremely important to improve patient compliance. Mixing oral solid dosage forms with food carriers is often necessary to ease swallowing and provide the taste-masking effect. The present research investigated how a liquid or semisolid carrier influences the disintegration time and drug dissolution rate of pellets and minitablets with diazepam. The disintegration of pellets and minitablets in liquid carriers (water, milk and apple juice) was determined using a texture analyser. Dissolution tests were performed for the dosage forms dispersed in gel vehicles (2% carmellose and 0.5% carbomer gels) or applesauce. The disintegration of minitablets in water and apple juice was fast (1 min), but it slowed to 3 and 5 min in milk and gel vehicles, respectively. The pellets disintegrated in liquid carriers within 3 min. The drug dissolution rate in 0.1 M HCl depended on the gel viscosity in this medium. The preserved high viscosity of a carmellose gel inhibited the dissolution of diazepam. On the other hand, the viscosity of the carbomer gel decreased rapidly, and in effect, the dissolution rate of diazepam from the incorporated pellets or minitablets was comparable to the dissolution from loose pellets or minitablets. Graphical abstract.


Assuntos
Ansiolíticos/administração & dosagem , Diazepam/administração & dosagem , Excipientes/administração & dosagem , Comprimidos , Administração Oral , Carboximetilcelulose Sódica , Formas de Dosagem , Humanos , Solubilidade , Viscosidade
12.
Environ Sci Pollut Res Int ; 27(34): 42960-42968, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32725559

RESUMO

Copper carboxymethyl cellulose nanoparticles were prepared and characterized by FT-IR, XRD, SEM, TEM, and EDX techniques. Removal of tetracycline was obtained at 90% with optimized parameters of 500 µg/L concentration, 40 min contact time, 7.5 pH, 1.5 g/L dose, and 298 K temp. The adsorption followed Freundlich model very well in comparison to Langmuir. Tempkin model described good interactions between tetracycline and nanoparticles. Dubinin-Radushkevich isotherm confirmed the chemical nature of adsorption. The adsorption was pseudo-second order with a liquid film diffusion kinetics mechanism. The adsorption was endothermic and spontaneous as suggested by thermodynamics results. The supramolecular mechanism was developed for the process. Interestingly, the process was suitable at 7.5 pH with low contact time. These features of the adsorption made this process applicable at natural water conditions, making the process eco-friendly and feasible. Therefore, it may be an excellent method for the removal of tetracycline in any water system.


Assuntos
Nanopartículas , Poluentes Químicos da Água , Adsorção , Antibacterianos , Carboximetilcelulose Sódica , Cobre , Concentração de Íons de Hidrogênio , Cinética , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica , Água , Poluentes Químicos da Água/análise
13.
Cochrane Database Syst Rev ; 7: CD008058, 2020 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-32725896

RESUMO

BACKGROUND: Burn injuries are an important health problem. They occur frequently in the head and neck region. The face is the area central to a person's identity that provides our most expressive means of communication. Topical interventions are currently the cornerstone of treatment of burns to the face. OBJECTIVES: To assess the effects of topical interventions on wound healing in people with facial burns of any depth. SEARCH METHODS: In December 2019 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting. SELECTION CRITERIA: Randomised controlled trials (RCTs) that evaluated the effects of topical treatment for facial burns were eligible for inclusion in this review. DATA COLLECTION AND ANALYSIS: Two review authors independently performed study selection, data extraction, risk of bias assessment and GRADE assessment of the certainty of the evidence. MAIN RESULTS: In this first update, we included 12 RCTs, comprising 507 participants. Most trials included adults admitted to specialised burn centres after recent burn injuries. Topical agents included antimicrobial agents (silver sulphadiazine (SSD), Aquacel-Ag, cerium-sulphadiazine, gentamicin cream, mafenide acetate cream, bacitracin), non-antimicrobial agents (Moist Exposed Burn Ointment (MEBO), saline-soaked dressings, skin substitutes (including bioengineered skin substitute (TransCyte), allograft, and xenograft (porcine Xenoderm), and miscellaneous treatments (growth hormone therapy, recombinant human granulocyte-macrophage colony-stimulating factor hydrogel (rhGMCS)), enzymatic debridement, and cream with Helix Aspersa extract). Almost all the evidence included in this review was assessed as low or very low-certainty, often because of high risk of bias due to unclear randomisation procedures (i.e. sequence generation and allocation concealment); lack of blinding of participants, providers and sometimes outcome assessors; and imprecision resulting from few participants, low event rates or both, often in single studies. Topical antimicrobial agents versus topical non-antimicrobial agents There is moderate-certainty evidence that there is probably little or no difference between antimicrobial agents and non-antimicrobial agents (SSD and MEBO) in time to complete wound healing (hazard ratio (HR) 0.84 (95% confidence interval (CI) 0.78 to 1.85, 1 study, 39 participants). Topical antimicrobial agents may make little or no difference to the proportion of wounds completely healed compared with topical non-antimicrobial agents (comparison SSD and MEBO, risk ratio (RR) 0.94, 95% CI 0.68 to 1.29; 1 study, 39 participants; low-certainty evidence). We are uncertain whether there is a difference in wound infection (comparison topical antimicrobial agent (Aquacel-Ag) and MEBO; RR 0.38, 95% CI 0.12 to 1.21; 1 study, 40 participants; very low-certainty evidence). No trials reported change in wound surface area over time or partial wound healing. There is low-certainty evidence for the secondary outcomes scar quality and patient satisfaction. Two studies assessed pain but it was incompletely reported. Topical antimicrobial agents versus other topical antimicrobial agents It is uncertain whether topical antimicrobial agents make any difference in effects as the evidence is low to very low-certainty. For primary outcomes, there is low-certainty evidence for time to partial (i.e. greater than 90%) wound healing (comparison SSD versus cerium SSD: mean difference (MD) -7.10 days, 95% CI -16.43 to 2.23; 1 study, 142 participants). There is very low-certainty evidence regarding whether topical antimicrobial agents make a difference to wound infection (RR 0.73, 95% CI 0.46 to 1.17; 1 study, 15 participants). There is low to very low-certainty evidence for the proportion of facial burns requiring surgery, pain, scar quality, adverse effects and length of hospital stay. Skin substitutes versus topical antimicrobial agents There is low-certainty evidence that a skin substitute may slightly reduce time to partial (i.e. greater than 90%) wound healing, compared with a non-specified antibacterial agent (MD -6.00 days, 95% CI -8.69 to -3.31; 1 study, 34 participants). We are uncertain whether skin substitutes in general make any other difference in effects as the evidence is very low certainty. Outcomes included wound infection, pain, scar quality, adverse effects of treatment and length of hospital stay. Single studies showed contrasting low-certainty evidence. A bioengineered skin substitute may slightly reduce procedural pain (MD -4.00, 95% CI -5.05 to -2.95; 34 participants) and background pain (MD -2.00, 95% CI -3.05 to -0.95; 34 participants) compared with an unspecified antimicrobial agent. In contrast, a biological dressing (porcine Xenoderm) might slightly increase pain in superficial burns (MD 1.20, 95% CI 0.65 to 1.75; 15 participants (30 wounds)) as well as deep partial thickness burns (MD 3.00, 95% CI 2.34 to 3.66; 10 participants (20 wounds)), compared with antimicrobial agents (Physiotulle Ag (Coloplast)). Miscellaneous treatments versus miscellaneous treatments Single studies show low to very low-certainty effects of interventions. Low-certainty evidence shows that MEBO may slightly reduce time to complete wound healing compared with saline soaked dressing (MD -1.7 days, 95% CI -3.32 to -0.08; 40 participants). In addition, a cream containing Helix Aspersa may slightly increase the proportion of wounds completely healed at 14 days compared with MEBO (RR 4.77, 95% CI 1.87 to 12.15; 43 participants). We are uncertain whether any miscellaneous treatment in the included studies makes a difference in effects for the outcomes wound infection, scar quality, pain and patient satisfaction as the evidence is low to very low-certainty. AUTHORS' CONCLUSIONS: There is mainly low to very low-certainty evidence on the effects of any topical intervention on wound healing in people with facial burns. The number of RCTs in burn care is growing, but the body of evidence is still hampered due to an insufficient number of studies that follow appropriate evidence-based standards of conducting and reporting RCTs.


Assuntos
Anti-Infecciosos/uso terapêutico , Queimaduras/terapia , Traumatismos Faciais/terapia , Pele Artificial , Administração Tópica , Anti-Infecciosos/administração & dosagem , Viés , Carboximetilcelulose Sódica/administração & dosagem , Carboximetilcelulose Sódica/uso terapêutico , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Cicatrização/efeitos dos fármacos
14.
Environ Sci Pollut Res Int ; 27(32): 40346-40354, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32666450

RESUMO

In this study, La(OH)3-modified magnetic sodium carboxymethyl cellulose (La-MC) was prepared as adsorbents for phosphate, which exhibited excellent adsorption performance up to 62.98 mg P/g and magnetic property for easy recovery. The recovered adsorbents after phosphate sorption were subsequently used for photocatalytic reduction of Cr(VI) and possessed good photocatalytic activity. This work provided an excellent reference for developing a new way of extending life cycle of adsorbents by combining phosphate adsorption with photocatalysis for sequential removal of pollutants from water in the future.


Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Adsorção , Carboximetilcelulose Sódica , Cromo , Cinética , Fenômenos Magnéticos , Fosfatos , Sódio , Poluentes Químicos da Água/análise
15.
Chemosphere ; 255: 127052, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32679636

RESUMO

In this study, polypyrrole/carboxymethyl cellulose nanocomposite particles (PPy/CMC NPs) were synthesized and applied for removal of reactive red 56 (RR56)and reactive blue 160 (RB160) as highly toxic dyes. The amount of CMC was found significantly effective on the surface adsorption efficiency. Different optimization methods including the genetic programming, response surface methodology, and artificial neural network (ANN) were used to optimize the effect of different parameters including pH, adsorption time, initial dye concentration and adsorbent dose. The maximum adsorption of RR56 and RB160 were found under the following optimum conditions: pH of 4 and 5, adsorption time of 55 min and 52 min for RR56 and RB160, respectively, initial dye concentration of 100 mg/L and adsorbent dose of 0.09 g for both dyes. were obtained for RR56 and RB160, respectively. Also, the results indicated that ANN method could predict the experimental adsorption data with higher accuracy than other methods. The analysis of ANN results indicated that the adsorbent dose is the main factor in RR56 removal, followed by time, pH and initial concentration, respectively. However, initial concentration mostly determines the RB160 removal process. The isotherm data for both dyes followed the Langmuir isotherm model with a maximum adsorption capacity of 104.9 mg/g and 120.7 mg/g for RR56 and RB160, respectively. In addition, thermodynamic studies indicated the endothermic adsorption process for both studied dyes. Moreover, DFT calculations were carried out to obtain more insight into the interactions between the dyes and adsorbent. The results showed that the hydrogen bondings and Van der Waals interactions are dominant forces between the two studied dyes and PPy/CMC composite. Furthermore, the interaction energies calculated by DFT confirmed the experimental adsorption data, where PPy/CMC resulted in higher removal of both dyes compared to PPy. The developed nanocomposite showed considerable reusability up to 3 cylces of the batch adsorption process.


Assuntos
Carboximetilcelulose Sódica/química , Corantes/química , Nanocompostos/química , Adsorção , Compostos Azo , Benzenossulfonatos , Teoria da Densidade Funcional , Cinética , Nanopartículas , Polímeros , Pirróis , Termodinâmica , Poluentes Químicos da Água
16.
PLoS One ; 15(6): e0233952, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32498075

RESUMO

This study aimed to produce cellulose-based conductive fabrics with electrical conductivity and flexibility. Bacterial cellulose (BC) and three chemical cellulose (CC), namely methyl cellulose (MC), hydroxypropyl cellulose (HPMC) and carboxymethyl cellulose (CMC) were in situ polymerized with aniline and the four conductive cellulose fabrics were compared and evaluated. Matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy analysis confirmed that three CC-PANI composites displayed longer and more stable polymerization pattern than BC-PANI because of the different polymerization method: bulk polymerization for BC-PANI and emulsion polymerization for CC-PANI, respectively. The electrical conductivity of BC-PANI and CC-PANI were ranging from 0.962 × 10-2 S/cm to 2.840 × 10-2 S/cm. MC-PANI showed the highest electrical conductivity among the four conductive cellulose fabrics. The flexibility and crease recovery results showed that MC-PANI had the highest flexibility compared to BC-PANI, HPMC-PANI, and CMC-PANI. These results have confirmed that the electrical conductivity and flexibility were influenced by the type of cellulose, and MC-PANI was found to have the best performance in the electrical conductivity and flexibility.


Assuntos
Carboximetilcelulose Sódica/química , Celulose/análogos & derivados , Metilcelulose/química , Polissacarídeos Bacterianos/química , Têxteis , Compostos de Anilina/química , Celulose/química , Elasticidade , Condutividade Elétrica , Nanocompostos/química , Polimerização , Têxteis/análise , Dispositivos Eletrônicos Vestíveis
17.
Phys Chem Chem Phys ; 22(26): 14579-14590, 2020 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-32597442

RESUMO

The formation of strongly elastic physical gels based on poly(alkylene oxide)-grafted hyaluronan or carboxymethylcellulose, exhibiting both shear-thickening and strain-hardening have been studied using rheometry and explained using a slightly different interpretation of the transient network theory. The graft copolymers were prepared by a quantitative coupling reaction. Their aqueous solutions displayed a thermoreversible continuous transition from Newtonian fluid to viscoelastic solid which could be controlled by the reaction conditions. The evolution of all material properties of the gel could be categorized into two distinct temperature regimes with a fast evolution at low temperatures followed by a slow evolution at high temperatures. The activation energy of the zero shear viscosity and the relaxation time of the graft inside the interconnecting microdomains were almost identical to each other in both temperature regimes. This suggests that the number of microdomains remained approximately constant whereas the aggregation number inside the microdomains increased according to the binodal curve of the thermosensitive graft.


Assuntos
Carboximetilcelulose Sódica/química , Ácido Hialurônico/química , Hidrogéis/química , Polímeros/química , Temperatura Baixa , Temperatura Alta , Transição de Fase , Reologia , Substâncias Viscoelásticas/química , Viscosidade
18.
Carbohydr Polym ; 239: 116217, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32414428

RESUMO

Formaldehyde was detected in dialdehyde carboxymethyl cellulose (DCMC) tanning agent prepared through periodate oxidation of sodium carboxymethyl cellulose (CMC). Formaldehyde was then introduced into leather through DCMC tanning, which poses a potential risk to human health. The formation mechanism of formaldehyde in DCMC was investigated by composition analysis and intermediate identification of DCMC with different polymerization degrees and sugar unit structures. Formaldehyde was derived from the overoxidation of C-6 on the reducing glucose residue of CMC. Moreover, glucose was produced from the concomitant degradation of CMC during oxidation, and then oxidized to liberate formaldehyde. The low degradation degree and high degree of substitution of CMC reduced the possibility of the formation of reducing glucose residue and glucose during oxidation, thereby resulting in low formaldehyde content in DCMC and DCMC-tanned leather. These findings serve as a foundation for the minimization of formaldehyde in DCMC and the development of ecological tanning approach.


Assuntos
Carboximetilcelulose Sódica/química , Celulose/análogos & derivados , Formaldeído/síntese química , Curtume , Configuração de Carboidratos , Celulose/química , Formaldeído/química , Oxirredução
19.
Artigo em Inglês | MEDLINE | ID: mdl-32348199

RESUMO

The aim of this study was to investigate the effects of carboxymethyl celluloses (CMC) with different structures (viscosity and degree of substitution) on the stability of tartrates as well as the growth mechanism of potassium bitartrate (KHT) crystals. Six CMC samples with different viscosity and degree of substitution were investigated by GPC, XRD and SEM to establish their molecular weight, crystal structure, particle size and molecular morphology. As oenological additives, they were studied in model solution and in Cabernet Sauvignon wine. The tartaric stability and inhibitory efficiency were evaluated by conductivity via mini-contact test and compared with metatartaric acid and mannoproteins commercial additives. The results suggest that under the same degree of substitution (DS), with an increase of viscosity, CMC molecular chains agglomerate and fold, the solubility in the wine decreases, thus the effect of stabilising tartrate deteriorates. Whilst at the same viscosity, with an increase of DS, the charge density of CMC molecules increases and the binding ability of ions increases and thus the stabilising tartrate has an obvious effect. The negative charge on the -COO- groups extended from CMC polymer tends to repulse the HT- group in solution while attracting K+ ions to produce a concentration gradient at the crystal surface. In addition, CMC complexes with K+ ions in solution, reducing the number of K+ ions able to diffuse to the adsorption layer. Generally, CMC-6 with a higher the degree of substitution and lower viscosity had best application effect on tartrate stabilisation, and from the price and application performance, CMC was found to be superior to commercial additives like metatartaric acid and mannoproteins.


Assuntos
Tartaratos/análise , Vinho/análise , Carboximetilcelulose Sódica/química , Estrutura Molecular , Peso Molecular , Tamanho da Partícula , Propriedades de Superfície , Viscosidade
20.
Artigo em Inglês | MEDLINE | ID: mdl-32183048

RESUMO

A typical sodium activated calcium bentonite (SACaB) was treated with carboxymethyl cellulose (CMC) polymer, called CMC-treated SACaB (CMC-SACaB), and it was investigated for its hydraulic conductivity and enhanced chemical compatibility. Index property and hydraulic conductivity tests were conducted on CMC-SACaB and SACaB with deionized water (DIW), heavy metals-laden water, and actual landfill leachate. Lead-zinc mixed (Pb-Zn) solution and hexavalent chromium (Cr(VI)) solution were selected as target heavy metals-laden water, and calcium (Ca) solution was tested for comparison purposes. The hydraulic conductivity (kMFL) was determined via the modified fluid loss (MFL) test. Liquid limit and swell index in DIW, heavy metal-laden water, and Ca solution increased with increasing CMC content. CMC treatment effectively decreased the kMFL of SACaB when exposed to Pb-Zn solutions with a metal concentration of 1 to 20 mmol/L and landfill leachate. An insignificant change in kMFL of CMC-SACaB occurred with exposure to Pb-Zn solutions with metal concentrations of 1 to 10 mmol/L, Cr(VI) and Ca solutions with metal concentration of 1 to 20 mmol/L, and landfill leachate. A slight increase in kMFL of CMC-SACaB was observed when Pb-Zn concentration increased to 20 mmol/L, and such an increment was more noticeable when the CMC content was lower than 10%. In the DIW, the measured kMFL values of CMC-SACaB and SACaB with a given range of void ratio were consistent with those obtained from the flexible-wall permeameter test.


Assuntos
Bentonita , Metais Pesados , Poluentes Químicos da Água , Cálcio , Carboximetilcelulose Sódica , Sódio
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