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1.
Int J Emerg Med ; 17(1): 119, 2024 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-39251897

RESUMEN

BACKGROUND: As with many countries worldwide, Singapore is experiencing a rapidly ageing population. Presentation of older persons for urgent but non-emergent conditions to the Emergency Department (ED) represents a growing group of patients utilising public healthcare emergency services and puts a strain on current ED resources. The medical conditions vary, and resources used has been poorly characterized. METHODS: This is a single-center cross-sectional observational study of patients aged 55 to 75 years old who visited the ED with urgent conditions, Patient Acuity Category Scale (PACS) P2 or P3, who were subsequently discharged. The patients visited a public hospital in Singapore on four randomly selected weekdays in April 2023. The utilisation of hospital resources and manpower was studied. A formulated criteria was used to determine the appropriate site of care, such as an Urgent Care Centre (UCC), Primary Care Providers (PCP) clinic or the ED. RESULTS: There were 235 eligible patients during the study period, with a mean age of 65.1 years of which a majority, 183 (77.9%) were allocated to patient acuity category scale P2. Most of the patients were walk-in patients with no referrals (169 (71.9%)). Based on the criteria, the majority of 187 (79.6%) of these patient may be safely managed at an outpatient setting; 71 (30.2%) patients by PCP, 116 (49.4%) patients may be managed by an UCC, with the remaining 48 (20.4%) requiring ED care. CONCLUSION: Our findings indicate that a significant portion of discharged older ED adults with urgent but non-emergent conditions may be adequately managed at outpatient medical services that are appropriately resourced. More research is needed on healthcare initiatives aimed at developing the capabilities of outpatient medical services to manage mild to moderate acute conditions to optimise ED resource allocation.

4.
BMJ Open Qual ; 13(3)2024 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-39084697

RESUMEN

In New York State, the Health Care Proxy Law allows patients to designate a person they trust to make medical decisions on their behalf should they lose the capacity to do so. In an Intensive Care Unit (ICU) setting, identification of a health care proxy (HCP) is especially important as patients are at heightened risk of losing decision-making capacity during their clinical course. While our hospital has guidelines to solicit and correctly document the patient's HCP information, it is not routinely done. Missing or incomplete HCP documentation is a prevalent issue, with lack of patient education, physical document issues, and time and workflow constraints commonly cited as barriers. We describe the implementation of a small-scale quality improvement project to increase the percentage of completed HCP documentation in our ICU through multi-faceted interventions targeting education, workflow, access, and technology.


Asunto(s)
Documentación , Unidades de Cuidados Intensivos , Apoderado , Mejoramiento de la Calidad , Humanos , Unidades de Cuidados Intensivos/organización & administración , Unidades de Cuidados Intensivos/estadística & datos numéricos , Documentación/métodos , Documentación/normas , Documentación/estadística & datos numéricos , Apoderado/estadística & datos numéricos , New York , Toma de Decisiones
5.
J Environ Manage ; 359: 120988, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38701587

RESUMEN

Microalgae demonstrate significant potential as a source of liquid-based biofuels. However, increasing biomass productivity in existing cultivation systems is a critical prerequisite for their successful integration into large-scale operations. Thus, the current work aimed to accelerate the growth of C. vulgaris via exogenous supplementation of biostimulant derived from onion peel waste. Under the optimal growth conditions, which entailed a biostimulant dosage of 37.5% v/v, a pH of 3, an air flow rate of 0.4 L/min, and a 2% v/v inoculum harvested during the mid-log phase, yielded a maximum biomass concentration of 1.865 g/L. Under the arbitrarily optimized parameters, a comparable growth pattern was evident in the upscaled cultivation of C. vulgaris, underscoring the potential commercial viability of the biostimulant. The biostimulant, characterized through gas chromatography-mass spectrometry (GC-MS) analysis, revealed a composition rich in polyphenolic and organo-sulphur compounds, notably including allyl trisulfide (28.13%), methyl allyl trisulfide (23.04%), and allyl disulfide (20.78%), showcasing potent antioxidant properties. Additionally, microalgae treated with the biostimulant consistently retained their lipid content at 18.44% without any significant reduction. Furthermore, a significant rise in saturated fatty acid (SFA) content was observed, with C16:0 and C18:1 dominating both bench-scale (44.08% and 14.01%) and upscaled (51.12% and 13.07%) microalgae cultures, in contrast to the control group where C18:2 was prevalent. Consequently, SFA contents reached 54.35% and 65.43% in bench-scale and upscaled samples respectively, compared to 33.73% in the control culture. These compositional characteristics align well with the requirements for producing high-quality crude biodiesel.


Asunto(s)
Biocombustibles , Biomasa , Microalgas , Cebollas , Microalgas/crecimiento & desarrollo , Cebollas/crecimiento & desarrollo , Cromatografía de Gases y Espectrometría de Masas
6.
Chron Respir Dis ; 21: 14799731241242490, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38545901

RESUMEN

OBJECTIVES: We aimed to evaluate the utility of an Observation Unit (OU) in management of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) and to identify the clinical characteristics of patients readmitted within 30-days for AECOPD following index admission to the OU or inpatient floor from the OU. METHODS: This is a retrospective observational study of patients admitted from January to December 2017 for AECOPD to an OU in an urban-based tertiary care hospital. Primary outcome was rate of 30-day readmission after admission for AECOPD for patients discharged from the OU versus inpatient service after failing OU management. Regression analyses were used to define risk factors. RESULTS: 163 OU encounters from 92 unique patients were included. There was a lower readmission rate (33%) for patients converted from OU to inpatient care versus patients readmitted after direct discharge from the OU (44%). Patients with 30-day readmissions were more likely to be undomiciled, with history of congestive heart failure (CHF), pulmonary embolism (PE), or had previous admissions for AECOPD. Patients with >6 annual OU visits for AECOPD had higher rates of substance abuse, psychiatric diagnosis, and prior PE; when these patients were excluded, the 30-day readmission rate decreased to 13.5%. CONCLUSION: Patients admitted for AECOPD with a history of PE, CHF, prior AECOPD admissions, and socioeconomic deprivation are at higher risk of readmission and should be prioritized for direct inpatient admission. Further prospective studies should be conducted to determine the clinical impact of this approach on readmission rates.


Asunto(s)
Readmisión del Paciente , Enfermedad Pulmonar Obstructiva Crónica , Humanos , Unidades de Observación Clínica , Pacientes Internos , Enfermedad Pulmonar Obstructiva Crónica/epidemiología , Enfermedad Pulmonar Obstructiva Crónica/terapia , Enfermedad Pulmonar Obstructiva Crónica/diagnóstico , Estudios Retrospectivos
7.
Nat Commun ; 15(1): 899, 2024 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-38321013

RESUMEN

Antigen-specific regulatory T cells (Tregs) suppress pathogenic autoreactivity and are potential therapeutic candidates for autoimmune diseases such as systemic lupus erythematosus (SLE). Lupus nephritis is associated with autoreactivity to the Smith (Sm) autoantigen and the human leucocyte antigen (HLA)-DR15 haplotype; hence, we investigated the potential of Sm-specific Tregs (Sm-Tregs) to suppress disease. Here we identify a HLA-DR15 restricted immunodominant Sm T cell epitope using biophysical affinity binding assays, then identify high-affinity Sm-specific T cell receptors (TCRs) using high-throughput single-cell sequencing. Using lentiviral vectors, we transduce our lead Sm-specific TCR into Tregs derived from patients with SLE who are anti-Sm and HLA-DR15 positive. Compared with polyclonal mock-transduced Tregs, Sm-Tregs potently suppress Sm-specific pro-inflammatory responses in vitro and suppress disease progression in a humanized mouse model of lupus nephritis. These results show that Sm-Tregs are a promising therapy for SLE.


Asunto(s)
Lupus Eritematoso Sistémico , Nefritis Lúpica , Ratones , Animales , Humanos , Linfocitos T Reguladores , Autoantígenos/metabolismo
8.
Biotechnol Adv ; 70: 108280, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37944570

RESUMEN

Microalgae showcase an extraordinary capacity for synthesizing high-value phytochemicals (HVPCs), offering substantial potential for diverse applications across various industries. Emerging research suggests that subjecting microalgae to abiotic stress during cultivation and the harvesting stages can further enhance the accumulation of valuable metabolites within their cells, including carotenoids, antioxidants, and vitamins. This study delves into the pivotal impacts of manipulating abiotic stress on microalgae yields, with a particular focus on biomass and selected HVPCs that have received limited attention in the existing literature. Moreover, approaches to utilising abiotic stress to increase HVPCs production while minimising adverse effects on biomass productivity were discussed. The present study also encompasses a techno-economic assessment (TEA) aimed at pinpointing significant bottlenecks in the conversion of microalgae biomass into high-value products and evaluating the desirability of various conversion pathways. The TEA methodology serves as a valuable tool for both researchers and practitioners in the quest to identify sustainable strategies for transforming microalgae biomass into high-value products and goods. Overall, this comprehensive review sheds light on the pivotal role of abiotic stress in microalgae cultivation, promising insights that could lead to more efficient and sustainable approaches for HVPCs production.


Asunto(s)
Microalgas , Microalgas/metabolismo , Estrés Fisiológico , Carotenoides/metabolismo , Biomasa , Biocombustibles
9.
PLOS Glob Public Health ; 3(12): e0002598, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38100392

RESUMEN

Dengue is the most rapidly emerging mosquito-borne infection and, due to climate change and unplanned urbanization, it is predicted that the global burden of dengue will rise further as the infection spreads to new geographical locations. Dengue-endemic countries are often unable to cope with such increases, with health care facilities becoming overwhelmed during each dengue season. Furthermore, although dengue has been predominantly a childhood illness in the past, it currently mostly affects adults in many countries, with higher incidence of severe disease and mortality rates in pregnant women and in those with comorbidities. As there is currently no specific treatment for dengue and no early biomarker to identify those who will progress to develop vascular leakage, all individuals with dengue are closely monitored in case they need fluid management. Furthermore, diagnosing patients with acute dengue is challenging due to the similarity of clinical symptoms during early illness and poor sensitivity and specificity of point-of-care diagnostic tests. Novel vector control methods, such as the release of Wolbachia-infected mosquitoes, have shown promising results by reducing vector density and dengue incidence in clinical trial settings. A new dengue vaccine, TAK-003, had an efficacy of 61.2% against virologically confirmed dengue, 84.1% efficacy against hospitalizations and a 70% efficacy against development of dengue haemorrhagic fever (DHF) at 54 months. While vaccines and mosquito control methods are welcome, they alone are unlikely to fully reduce the burden of dengue, and a treatment for dengue is therefore essential. Several novel antiviral drugs are currently being evaluated along with drugs that inhibit host mediators, such as mast cell products. Although viral proteins such as NS1 contribute to the vascular leak observed in severe dengue, the host immune response to the viral infection also plays a significant role in progression to severe disease. There is an urgent need to discover safe and effective treatments for dengue to prevent disease progression.

10.
Bioresour Technol ; 386: 129531, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37473787

RESUMEN

This study performs the comparative advantage analysis of oxidative torrefaction of corn stalks to investigate the advantages of oxidative torrefaction for biochar fuel property upgrading. The obtained results indicate that oxidative torrefaction is more efficient in realizing mass loss and energy density improvement, as well as elemental carbon accumulation and surface functional groups removal, and thus leads to a better fuel property. The maximum values of relative mass loss, higher heating value, enhancement factor, and energy yield are 3.00, 1.10, 1.03, and 0.87, respectively. The relative elemental carbon, hydrogen, and oxygen content ranges are 1.30-3.10, 1.50-3.30, and 2.00-6.80, respectively. In addition, an excellent linear distribution is obtained between the comprehensive pyrolysis index and torrefaction severity index, with elemental carbon and oxygen component variation stemming from pyrolysis performance correlating to the elemental component and valance.


Asunto(s)
Biocombustibles , Carbono , Biomasa , Temperatura , Oxígeno , Estrés Oxidativo
11.
Appl Microbiol Biotechnol ; 107(15): 4789-4801, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37314456

RESUMEN

Conventional techniques to remove Fe impurities in kaolin typically involve high environmental impact and cost. Alternative methods have been focused on the use of bioleaching where Fe in kaolin is reduced with microorganisms. Early results established a noticeable effect of the bacteria on the redox state of Fe, but knowledge gaps persist such as details on the bacterial-kaolin interactions during attachment of bacteria onto kaolin surface, the metabolites produced by bacteria, and changes in Fe(II)/Fe(III) ion equilibria in solution. To bridge these gaps, this study was conducted to determine the detailed physicochemical changes in bacteria and kaolin during bioleaching through surface, structural, and chemical analysis. Bioleaching experiments were conducted for 10 days where each of the three Bacillus sp. was put in contact (at 9 × 108 CFU) with 20 g of kaolin powder using 200 mL of 10 g/L glucose solution. All samples treated with bacteria showed increasing trends in Fe(III) reduction up until day 6 or 8 followed by a slight decrease towards the end of the ten-day period. Examination of scanning electron microscope (SEM) images suggests that bacterial activity damaged the edges of kaolin particles during bioleaching. Ion chromatography (IC) results showed that during bioleaching, Bacillus sp. produced organic acids such as lactic acid, formic acid, malic acid, acetic acid, and succinic acid. EDS analysis of kaolin before and after bioleaching showed Fe removal efficiencies of up to 65.3%. Analyses of color properties of kaolin before and after bioleaching showed an improvement in whiteness index of up to 13.6%. KEY POINTS: • Dissolution of iron oxides by Bacillus species proven with phenanthroline analysis. • Organic acid type and concentration unique to species detected during bioleaching. • Whiteness index of kaolin is improved after bioleaching.


Asunto(s)
Bacillus , Bacillus/metabolismo , Compuestos Férricos/metabolismo , Hierro/metabolismo , Caolín/metabolismo , Bacterias/metabolismo
12.
Singapore Med J ; 2023 05 12.
Artículo en Inglés | MEDLINE | ID: mdl-37171447

RESUMEN

It is crucial that policy makers, healthcare providers and relevant stakeholders understand how integrated care may be improved at our emergency departments (EDs) and what benefits that would bring. The potential that exists for right-siting care of special patient groups who could be managed in an ambulatory setting with the integration of a variety of hospital-based and community-based clinical support services is tremendous. This review describes the best practice and value of integrated care at the EDs. Local evidence is cited and compared with findings from overseas. The opportunities of care transition interventions among discharged patients are outlined, including that for paediatric patients, palliative care patients and patients with chronic diseases. This review also suggests ways to move forward to meet the aim of providing holistic care at EDs through integrated care programmes, innovation and research.

13.
Ann Acad Med Singap ; 52(4): 182-189, 2023 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-38904531

RESUMEN

Introduction: Transitional care strategies (TCS) initiated for elderly patients prior to emergency department (ED) discharge are important for ensuring effective transition to other care settings. Such strategies have been shown to reduce avoidable acute admissions. This first nationwide study is targeted at public acute hospital EDs in Singapore, and aims to characterise TCS for ED-discharged elderly patients and understand the experiences of healthcare staff in the delivery of TCS. Method: Seven key informants (KIs), one per ED, completed an online structured questionnaire and semi-structured video conference interview from 8 May to 31 August 2021. The KIs were ED specialists and an ED-trained senior staff nurse who were knowledgeable in geriatric emergency care and had contributed to at least one elder-related TCS. Field notes were compiled, transcribed, anonymised and analysed using thematic analysis. Results: All 7 EDs have TCS as "usual care" available during office hours, at no extra cost to patients. Common components of TCS include screening, evaluation with comprehensive geriatric assessment, health education and follow-up telecare. TCS implementation was facilitated by organisational support in terms of established protocols and communication platforms, training and collaboration of a multidisciplinary team, and caregiver involvement. Obstacles faced include fragmented communication between personnel, limited resources, and poor buy-in from stakeholders. Conclusion: Understanding the heterogeneous characteristics of ED-TCS at various hospitals will aid the development of service typology and identify service opportunities. Provider experiences grouped into themes help to inform future strategies for TCS implementation. More research is needed to evaluate patient outcomes and cost-effectiveness of TCS.


Asunto(s)
Servicio de Urgencia en Hospital , Cuidado de Transición , Humanos , Singapur , Anciano , Cuidado de Transición/organización & administración , Alta del Paciente , Masculino , Femenino , Evaluación Geriátrica/métodos , Encuestas y Cuestionarios , Telemedicina
14.
Polymers (Basel) ; 14(23)2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-36501638

RESUMEN

Biomass-derived cellulose hybrid composite materials are promising for application in the field of photocatalysis due to their excellent properties. The excellent properties between biomass-derived cellulose and photocatalyst materials was induced by biocompatibility and high hydrophilicity of the cellulose components. Biomass-derived cellulose exhibited huge amount of electron-rich hydroxyl group which could promote superior interaction with the photocatalyst. Hence, the original sources and types of cellulose, synthesizing methods, and fabrication cellulose composites together with applications are reviewed in this paper. Different types of biomasses such as biochar, activated carbon (AC), cellulose, chitosan, and chitin were discussed. Cellulose is categorized as plant cellulose, bacterial cellulose, algae cellulose, and tunicate cellulose. The extraction and purification steps of cellulose were explained in detail. Next, the common photocatalyst nanomaterials including titanium dioxide (TiO2), zinc oxide (ZnO), graphitic carbon nitride (g-C3N4), and graphene, were introduced based on their distinct structures, advantages, and limitations in water treatment applications. The synthesizing method of TiO2-based photocatalyst includes hydrothermal synthesis, sol-gel synthesis, and chemical vapor deposition synthesis. Different synthesizing methods contribute toward different TiO2 forms in terms of structural phases and surface morphology. The fabrication and performance of cellulose composite catalysts give readers a better understanding of the incorporation of cellulose in the development of sustainable and robust photocatalysts. The modifications including metal doping, non-metal doping, and metal-organic frameworks (MOFs) showed improvements on the degradation performance of cellulose composite catalysts. The information and evidence on the fabrication techniques of biomass-derived cellulose hybrid photocatalyst and its recent application in the field of water treatment were reviewed thoroughly in this review paper.

15.
Artículo en Inglés | MEDLINE | ID: mdl-36417069

RESUMEN

Together with the rapid growth of technology, the discharge of wastewater from industry into environment had become a hot topic among society nowadays. More attention had been given to the development of water treatment techniques. In this study, sonocatalysis was proposed to degrade the organic pollutants using silver-doped zinc oxide (Ag-ZnO) nanoparticles which were synthesized via green synthesis process using Clitoria ternatea Linn (Asian Pigeonwings flower). The characterization results revealed that the incorporation of Ag into the ZnO lattice decreased the crystallite size and increased the specific surface area of ZnO nanoparticles. It is noteworthy that about 98% of sonocatalytic degradation efficiency of malachite green (MG) was successfully achieved within 30 min in the presence of 5 wt.% Ag-ZnO with 1.0 g/L of catalyst loading under 500 mg/L of initial dye concentration, 80 W of ultrasonic power, 45 kHz of ultrasound frequency, and 2.0 mM of oxidant concentration. The kinetic study showed that the sonocatalytic degradation of organic dye was fitted well into second-order kinetic model with high R2 value (0.9531). In the thermodynamic study, negative value of standard Gibbs free energy and low value of activation energy (+ 24.43 kJ/mol) were obtained in the sonocatalytic degradation of MG using the green-synthesized Ag-ZnO sample. HIGHLIGHTS: • Facile synthesis of silver-doped zinc oxide nanoparticles using plant extract which act as reducing and stabilizing agents • Optical, physical, and chemical characterization of green-synthesized nanomaterials were performed • Evaluation of sonocatalytic degradation of organic dye using green-synthesized nanomaterials • Sonocatalytic behavior, kinetic and thermodynamic studies of sonocatalytic reaction.

16.
Biomass Convers Biorefin ; : 1-37, 2022 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-35316983

RESUMEN

The extensive growth of energy and plastic demand has raised concerns over the depletion of fossil fuels. Moreover, the environmental conundrums worldwide integrated with global warming and improper plastic waste management have led to the development of sustainable and environmentally friendly biofuel (bioethanol) and biopolymer (lactic acid, LA) derived from biomass for fossil fuels replacement and biodegradable plastic production, respectively. However, the high production cost of bioethanol and LA had limited its industrial-scale production. This paper has comprehensively reviewed the potential and development of third-generation feedstock for bioethanol and LA production, including significant technological barriers to be overcome for potential commercialization purposes. Then, an insight into the state-of-the-art hydrolysis and fermentation technologies using macroalgae as feedstock is also deliberated in detail. Lastly, the sustainability aspect and perspective of macroalgae biomass are evaluated economically and environmentally using a developed cascading system associated with techno-economic analysis and life cycle assessment, which represent the highlights of this review paper. Furthermore, this review provides a conceivable picture of macroalgae-based bioethanol and lactic acid biorefinery and future research directions that can be served as an important guideline for scientists, policymakers, and industrial players.

18.
JAMA Intern Med ; 182(4): 426-435, 2022 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-35179551

RESUMEN

Importance: Ivermectin, an inexpensive and widely available antiparasitic drug, is prescribed to treat COVID-19. Evidence-based data to recommend either for or against the use of ivermectin are needed. Objective: To determine the efficacy of ivermectin in preventing progression to severe disease among high-risk patients with COVID-19. Design, Setting, and Participants: The Ivermectin Treatment Efficacy in COVID-19 High-Risk Patients (I-TECH) study was an open-label randomized clinical trial conducted at 20 public hospitals and a COVID-19 quarantine center in Malaysia between May 31 and October 25, 2021. Within the first week of patients' symptom onset, the study enrolled patients 50 years and older with laboratory-confirmed COVID-19, comorbidities, and mild to moderate disease. Interventions: Patients were randomized in a 1:1 ratio to receive either oral ivermectin, 0.4 mg/kg body weight daily for 5 days, plus standard of care (n = 241) or standard of care alone (n = 249). The standard of care consisted of symptomatic therapy and monitoring for signs of early deterioration based on clinical findings, laboratory test results, and chest imaging. Main Outcomes and Measures: The primary outcome was the proportion of patients who progressed to severe disease, defined as the hypoxic stage requiring supplemental oxygen to maintain pulse oximetry oxygen saturation of 95% or higher. Secondary outcomes of the trial included the rates of mechanical ventilation, intensive care unit admission, 28-day in-hospital mortality, and adverse events. Results: Among 490 patients included in the primary analysis (mean [SD] age, 62.5 [8.7] years; 267 women [54.5%]), 52 of 241 patients (21.6%) in the ivermectin group and 43 of 249 patients (17.3%) in the control group progressed to severe disease (relative risk [RR], 1.25; 95% CI, 0.87-1.80; P = .25). For all prespecified secondary outcomes, there were no significant differences between groups. Mechanical ventilation occurred in 4 (1.7%) vs 10 (4.0%) (RR, 0.41; 95% CI, 0.13-1.30; P = .17), intensive care unit admission in 6 (2.4%) vs 8 (3.2%) (RR, 0.78; 95% CI, 0.27-2.20; P = .79), and 28-day in-hospital death in 3 (1.2%) vs 10 (4.0%) (RR, 0.31; 95% CI, 0.09-1.11; P = .09). The most common adverse event reported was diarrhea (14 [5.8%] in the ivermectin group and 4 [1.6%] in the control group). Conclusions and Relevance: In this randomized clinical trial of high-risk patients with mild to moderate COVID-19, ivermectin treatment during early illness did not prevent progression to severe disease. The study findings do not support the use of ivermectin for patients with COVID-19. Trial Registration: ClinicalTrials.gov Identifier: NCT04920942.


Asunto(s)
COVID-19 , Ivermectina , Adulto , Progresión de la Enfermedad , Femenino , Mortalidad Hospitalaria , Humanos , Ivermectina/efectos adversos , Ivermectina/uso terapéutico , Persona de Mediana Edad , SARS-CoV-2 , Resultado del Tratamiento
19.
Polymers (Basel) ; 14(4)2022 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-35215577

RESUMEN

Petroleum-based plastics are associated with environmental pollution problems owing to their non-biodegradable and toxic properties. In this context, renewable and biodegradable bioplastics possess great potential to replace petroleum-based plastics in mitigating these environmental issues. Fabrication of bioplastic films involves a delicate mixture of the film-forming agent, plasticizer and suitable solvent. The role of the plasticizer is to improve film flexibility, whereas the filler serves as a reinforcement medium. In recent years, much research attention has been shifted toward devising diverse methods for enhancing the performance of bioplastics, particularly in the utilization of environmentally benign nanoparticles to displace the conventional hazardous chemicals. Along this line, this paper presents the emergence of nanofillers and plasticizers utilized in bioplastic fabrication with a focus on starch-based bioplastics. This review paper not only highlights the influencing factors that affect the optical, mechanical and barrier properties of bioplastics, but also revolves around the proposed mechanism of starch-based bioplastic formation, which has rarely been reviewed in the current literature. To complete the review, prospects and challenges in bioplastic fabrication are also highlighted in order to align with the concept of the circular bioplastic economy and the United Nations' Sustainable Development Goals.

20.
Polymers (Basel) ; 14(2)2022 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-35054685

RESUMEN

Bioplastic has been perceived as a promising candidate to replace petroleum-based plastics due to its environment-friendly and biodegradable characteristics. This study presents the chitosan reinforced starch-based bioplastic film prepared by the solution casting and evaporation method. The effects of processing parameters, i.e., starch concentration, glycerol loading, process temperature and chitosan loading on mechanical properties were examined. Optimum tensile strength of 5.19 MPa and elongation at break of 44.6% were obtained under the combined reaction conditions of 5 wt.% starch concentration, 40 wt.% glycerol loading, 20 wt.% chitosan loading and at a process temperature of 70 °C. From the artificial neural network (ANN) modeling, the coefficient of determination (R2) for tensile strength and elongation at break were found to be 0.9955 and 0.9859, respectively, which proved the model had good fit with the experimental data. Interaction and miscibility between starch and chitosan were proven through the peaks shifting to a lower wavenumber in FTIR and a reduction of crystallinity in XRD. TGA results suggested the chitosan-reinforced starch-based bioplastic possessed reasonable thermal stability under 290 °C. Enhancement in water resistance of chitosan-incorporated starch-based bioplastic film was evidenced with a water uptake of 251% as compared to a 302% registered by the pure starch-based bioplastic film. In addition, the fact that the chitosan-reinforced starch-based bioplastic film degraded to 52.1% of its initial weight after 28 days suggests it is a more sustainable alternative than the petroleum-based plastics.

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