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1.
Environ Res ; 223: 115429, 2023 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-36746207

RESUMEN

Cellulose is the most abundant polysaccharide on earth. It has a large number of desirable properties. Its low toxicity makes it more useful for a variety of applications. Nowadays, its composites are used in most engineering fields. Composite consists of a polymer matrix and use as a reinforcing material. By reducing the cost of traditional fibers, it has an increasing demand for environment-friendly purposes. The use of these types of composites is inherent in moisture absorption with hindered natural fibers. This determines the reduction of polymer composite material. By appropriate chemical surface treatment of cellulose composite materials, the effect could be diminished. The most modern and advanced techniques and methods for the preparation of cellulose and polymer composites are discussed here. Cellulosic composites show a reinforcing effect on the polymer matrix as pointed out by mechanical characterization. Researchers tried their hard work to study different ways of converting various agricultural by-products into useful eco-friendly polymer composites for sustainable production. Cellulose plays building blocks, that are critical for polymer products and their engineering applications. The most common method used to prepare composites is in-situ polymerization. This help to increase the yields of cellulosic composites with a significant enhancement in thermal stability and mechanical properties. Recently, cellulose composites used as enhancing the incorporation of inorganic materials in multi-functional properties. Furthermore, we have summarized in this review the potential applications of cellulose composites in different fields like packaging, aerogels, hydrogels, and fibers.


Asunto(s)
Celulosa , Polímeros , Celulosa/química , Estudios Prospectivos
2.
Environ Res ; 219: 115091, 2023 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-36529323

RESUMEN

Textile and printing industries play a vital role in the economy of any country. But the effluents of these industries, which contain toxic Methylene Blue (MB) dye when mixed with fresh water, make it unfit for human health and aquatic life. For the removal of MB, different adsorbents were used, but they were expensive, non-biodegradable or less effective. In this research, novel carboxymethyl starch grafted poly 2-carboxyethyl acrylate (CM-St-g-P2CEtA) was synthesized by reacting carboxymethyl starch with 2-carboxyethyl acrylate. The reaction followed a free radical polymerization mechanism. The structure and properties of CM-St-g-P2CEtA were investigated by advanced analytical techniques. The CM-St-g-P2CEtA was employed for the remediation of Methylene Blue (MB) dye from wastewater. The removal percentage (%R) of MB was checked under different parameters, like different pH levels, different initial concentrations of dye, different adsorbent doses, and different contact times. The results obtained during the experiment were subjected to different adsorption and kinetic models. In the kinetic investigation, the experimental results were best represented by the pseudo-second-order kinetic model due to its high R2 value of 0.999. Similarly, with a regression coefficient (R2) value of 0.947, the Langmuir adsorption isotherm was best represented by the experimental results. The Langmuir adsorption model showed that MB dye was adsorbed on the surface of CM-St-g-P2CEtA in a monolayer pattern. The pseudo 2nd order kinetic model suggested that the adsorption process favored chemisorption mechanism. The CM-St-g-P2CEtA showed maximum percentage removal efficiency (%R) of 99.3% for MB dye.


Asunto(s)
Aguas Residuales , Contaminantes Químicos del Agua , Humanos , Azul de Metileno/química , Contaminantes Químicos del Agua/química , Concentración de Iones de Hidrógeno , Adsorción , Cinética
3.
Environ Res ; 222: 115253, 2023 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-36702191

RESUMEN

Epoxy resins are important thermosetting polymers. They are widely used in many applications i.e., adhesives, plastics, coatings and sealers. Epoxy molding compounds have attained dominance among common materials due to their excellent mechanical properties. The sol-gel simple method was applied to distinguish the impact on the colloidal time. The properties were obtained with silica-based fillers to enable their mechanical and thermal improvement. The work which we have done here on epoxy-based nanocomposites was successfully modified. The purpose of this research was to look into the effects of cellulose nanocrystals (CNCs) on various properties and applications. CNCs have recently attracted a lot of interest in a variety of industries due to their high aspect ratio, and low density which makes them perfect candidates. Adding different amounts of silica-based nanocomposites to the epoxy system. Analyzed with different techniques such as Fourier-transformed infrared spectroscope (FTIR), thermogravimetric analysis (TGA) and scanning electronic microscopic (SEM) to investigate the morphological properties of modified composites. The various %-age of silica composite was prepared in the epoxy system. The 20% of silica was shown greater enhancement and improvement. They show a better result than D-400 epoxy. Increasing the silica, the transparency of the films decreased, because clustering appears. This shows that the broad use of CNCs in environmental engineering applications is possible, particularly for surface modification, which was evaluated for qualities such as absorption and chemical resistant behavior.


Asunto(s)
Celulosa , Nanopartículas , Celulosa/química , Celulosa/ultraestructura , Porosidad , Agua/química , Dióxido de Silicio/química , Nanopartículas/química
4.
Pak J Med Sci ; 39(3): 795-798, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37250575

RESUMEN

Objective: To evaluate the efficacy of hematological parameters to predict severity of COVID-19 patients. Method: This was a cross-sectional comparative study conducted at Central Park Teaching Hospital, Lahore in COVID ward and COVID ICU between April 23, 2021 to June 23, 2021. Patients of all ages and both genders with positive PCR admitted in the COVID ward and ICU during this time span of two months were included in the study. Data was collected retrospectively. Results: This study included 50 patients with male to female ratio of 1.38:1. Though males are more affected by COVID-19 but the difference is not statistically significant. The mean age of the study population was 56.21 and the patients in the severe disease group have higher age. It was observed that in severe/critical group the mean values of total leukocyte count 21.76×103 µI (p-value= 0.002), absolute neutrophil count 71.37% (p-value=0.045), neutrophil lymphocyte ratio (NLR) 12.80 (p-value=0.00) and PT 11.9 seconds (p-value=0.034) and the difference was statistically significant. While in severe/critical group, the mean values of hemoglobin 12.03g/dl (p-value=0.075), lymphocyte count 28.41% (p-value=0.8), platelet count 226×103 µI (p-value=0.67) and APTT 30.7 (p-value=0.081) and the difference was not significantly different between groups. Conclusion: It can be concluded from the study that total leucocyte count, absolute neutrophil count and neutrophil lymphocyte ratio can predict in-hospital mortality and morbidity in COVID-19 patients.

5.
Environ Res ; 215(Pt 1): 114241, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36100100

RESUMEN

This study is based on the removal of methylene blue (MB) from aqueous solution by cost effective and biodegradable adsorbent carboxymethyl starch grafted polyvinyl pyrolidone (Car-St-g-PVP). The Car-St-g-PVP was synthesized by grafting vinyl pyrolidone onto carboxymethyl starch by free radical polymerization reaction. The structure and different properties of Car-St-g-PVP were determined by 1H NMR, FT-IR, XRD, TGA and SEM. A series of batch experiments were conducted for the removal of MB, The adsorption affecting factors such as temperature, contact time, initial concentration of MB dye, dose of Car-St-g-PVP and pH were studied in detail. The other parameters like the thermodynamic study, kinetics and isothermal models were fitted to the experimental data. The results showed that pseudo 2nd order kinetics and Langmuir's adsorption isotherms were best fitted to experimental data with regression coefficient R2 viz. 0.99 and 0.97. The kinetic study showed that the adsorption mechanism favored chemisorption. The Gibbs free energy (ΔG°) for the adsorption process was found to be -7.31 kJ/mol, -8.23 kJ/mol, -9.00 kJ/mol and -10.10 kJ/mol at 25 °C, 35 °C, 45 °C and 55 °C respectively. The negative values of ΔG° suggested the spontaneous nature of the adsorption process. Similarly, the positive values of entropy (ΔS°) and enthalpy (ΔH°) 91.27 J/k.mol and 19.90 kJ/mol showed the increasing randomness and endothermic nature of the adsorption process. The value of separation factor (RL) was found to be less than one (RL < 1), which supported the feasibility of the adsorption process. The maximum MB removal percentage (% R) was found to be 98.6%. So, these findings show that Car-St-g-PVP can be meritoriously used for the treatment of MB from wastewater.


Asunto(s)
Azul de Metileno , Contaminantes Químicos del Agua , Adsorción , Ácidos Carboxílicos , Concentración de Iones de Hidrógeno , Cinética , Azul de Metileno/química , Polivinilos , Povidona , Espectroscopía Infrarroja por Transformada de Fourier , Almidón , Termodinámica , Aguas Residuales
6.
Molecules ; 27(18)2022 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-36144579

RESUMEN

In this research, a new biodegradable and eco-friendly adsorbent, starch-grafted polymethyl methacrylate (St-g-PMMA) was synthesized. The St-g-PMMA was synthesized by a free radical polymerization reaction in which methyl methacrylate (MMA) was grafted onto a starch polymer chain. The reaction was performed in water in the presence of a potassium persulfate (KPS) initiator. The structure and different properties of the St-g-PMMA was explored by FT-IR, 1H NMR, TGA, SEM and XRD. After characterization, the St-g-PMMA was used for the removal of MB dye. Different adsorption parameters, such as effect of adsorbent dose, effect of pH, effect of initial concentration of dye solution, effect of contact time and comparative adsorption study were investigated. The St-g-PMMA showed a maximum removal percentage (R%) of 97% towards MB. The other parameters, such as the isothermal and kinetic models, were fitted to the experimental data. The results showed that the Langmuir adsorption and pseudo second order kinetic models were best fitted to experimental data with a regression coefficient of R2 = 0.93 and 0.99, respectively.


Asunto(s)
Azul de Metileno , Contaminantes Químicos del Agua , Adsorción , Radicales Libres , Gentamicinas , Concentración de Iones de Hidrógeno , Cinética , Metacrilatos , Metilmetacrilatos , Polimerizacion , Polimetil Metacrilato , Espectroscopía Infrarroja por Transformada de Fourier , Almidón/química , Agua , Contaminantes Químicos del Agua/química
7.
Trials ; 24(1): 448, 2023 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-37424031

RESUMEN

BACKGROUND: Hypertension is a highly relevant public health challenge. Digital interventions may support improving adherence to anti-hypertensive medications and alter health behavior. Therefore, this protocol describes a study that aims to assess the effectiveness of mHealth and educational support through peer counseling (Ed-counselling) to control blood pressure in hypertensive patients when compared to standard care. METHODS: We chose a double-blinded pragmatic randomized-controlled with factorial design for this investigation. The trial is going to recruit 1648 hypertensive patients with coronary artery disease at the age of 21 to 70 years. All participants will already be on anti-hypertensive medication and own a smartphone. They will be randomized into four groups with each having 412 participants. The first group will only receive standard care; while the second group, in addition to standard care, will receive monthly Ed-counselling (educational booklets with animated infographics and peer counseling); the third group will receive daily written and voice reminders and an education-led video once weekly together with standard care; while the fourth one gets both interventions given to second and third groups respectively. All groups will be followed-up for 1 year (0, 6, and 12 months). The primary outcome will be the change in systolic blood pressure while secondary outcomes include health-related quality of life and changes in medication adherence. For measuring changes in systolic blood pressure (SBP) and adherence scores difference at 0, 6, and 12 months between and within the group, parametric (ANOVA/repeated measure ANOVA) and non-parametric tests (Kruskal-Wallis test/Friedman test) will be used. By using the general estimating equation (GEE) with negative binomial regression, at 12 months, the covariates affecting primary and secondary outcomes will be determined and controlled. The analysis will be intention-to-treat. All the outcomes will be analyzed at 0, 6, and 12 months; however, the final analysis will be at 12 months from baseline. DISCUSSION: Besides adding up to existing evidence in the literature on the subject, our designed modules using mHealth technology can help in reducing hypertension-related morbidity and mortality in developing countries.


Asunto(s)
Enfermedad de la Arteria Coronaria , Hipertensión , Telemedicina , Humanos , Adulto Joven , Adulto , Persona de Mediana Edad , Anciano , Enfermedad de la Arteria Coronaria/terapia , Enfermedad de la Arteria Coronaria/tratamiento farmacológico , Antihipertensivos/efectos adversos , Calidad de Vida , Pakistán , Hipertensión/diagnóstico , Hipertensión/tratamiento farmacológico , Cumplimiento de la Medicación , Consejo , Telemedicina/métodos , Ensayos Clínicos Controlados Aleatorios como Asunto
8.
Chemosphere ; 321: 138000, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36724851

RESUMEN

In this research article, novel starch phosphate grafted polyvinyl imidazole (StP-g-PIMDZs) was synthesized. Firstly, a phosphate group was attached to starch polymer via a phosphorylation reaction. Next, 1-vinyl imidazole (VIMDZ) was grafted on the backbone of starch phosphate (StP) through a free radical polymerization reaction. The synthesis of these modified starches was confirmed by 1H NMR, 31P NMR and FT-IR techniques. The grafting of vinyl imidazole onto StP diminished the crystallinity. Due to the insertion of the aromatic imidazole ring, the StP-g-PIMDZs demonstrated greater thermal stability. The StP and StP-g-PIMDZs were used as sorbents for the adsorption of methylene blue dye (MBD) from the model solution. The maximum removal percentage for starch, StP, StP-g-PIMDZ 1, StP-g-PIMDZ 2 and StP-g-PIMDZ 3 was found to be 60.6%, 66.7%, 74.2%, 85.3 and 95.4%, respectively. The Pseudo second order kinetic model and Langmuir adsorption isotherm were best suited to the experimental data with R2 = 0.999 and 0.99, respectively. Additionally, the thermodynamic parameters showed that the adsorption process was feasible, spontaneous, endothermic and favored chemi-sorption mechanism.


Asunto(s)
Azul de Metileno , Contaminantes Químicos del Agua , Azul de Metileno/química , Espectroscopía Infrarroja por Transformada de Fourier , Contaminantes Químicos del Agua/química , Concentración de Iones de Hidrógeno , Termodinámica , Adsorción , Cinética , Almidón
9.
Chemosphere ; 321: 137999, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36724850

RESUMEN

Green and efficient removal of polluted materials are essential for the sustainability of a clean and green environment. Nanomaterials, particularly cellulose nanocrystals (CNCs), are abundant in nature and can be extracted from various sources, including cotton, rice, wheat, and plants. CNCs are renewable biomass materials with a high concentration of polar functional groups. This study used succinic anhydride to modify the surface of native cellulose nanocrystals (NCNCs). Succinic anhydride has been frequently used in adhesives and sealant chemicals for a long time, and here, it is evaluated for dye removal performance. The morphology and modification of CNCs studied using FTIR, TGA & DTG, XRD, SEM, AFM, and TEM. The ability of modified cellulose nanocrystals (MCNCs) to adsorb cationic golden yellow dye and methylene blue dye was investigated. The MCNCs exhibited high adsorption affinity for the two different cationic dyes. The maximum adsorption efficiency of NCNCs and MCNCs towards the cationic dye was 0.009 and 0.156 wt%. The investigation for adhesive properties is based on the strength and toughness of MCNCs. MCNCs demonstrated improved tensile strength (2350 MPa) and modulus (13.9 MPa) using E-51 epoxy system and a curing agent compared to 3 wt% composites. This research lays the groundwork for environmentally friendly fabrication and consumption in the industrial sector.


Asunto(s)
Colorantes , Nanopartículas , Colorantes/química , Anhídridos Succínicos , Adsorción , Celulosa/química , Nanopartículas/química , Cationes
10.
Chemosphere ; 339: 139637, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37499806

RESUMEN

The presence of dyes in contaminated water poses substantial dangers to the health of both humans and aquatic life. A process called precipitation polymerization was used to create unique cross-linked hexa-chlorocyclotriphosphazene-co-phenolphthalein (Hex-CCP-co-PPT) microspheres for the purpose of this research. Advanced methods such as X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential thermogravimetry (DTG) were used to characterise these microspheres. In a simulated solution, the performance of Hex-CCP-co-PPTs as a sorbent for removing MB dye was investigated, and the results showed an unprecedentedly high removal rate of 88.4% for MB. Temperature of 25 °C, a Hex-CCP-co-PPTs dose of 40 mg, an MB concentration of 20 ppm, an MB solution volume of 20 mL, a contact time of 40 min, and a pH of 9 were found to be the optimal experimental conditions. According to the results of the kinetic and adsorption analyses, the PSO and Langmuir adsorption models are the best ones to use. These models favour the chemi-sorption nature and mono-layered adsorption of MB in comparison to Hex-CCP-co-PPTs. Importantly, the thermodynamic analysis demonstrated that the process of removing MB by utilizing Hex-CCP-co-PPTs was endothermic and occurred spontaneously. These findings highlight the potential application of Hex-CCP-co-PPT microspheres in Algal Membrane Bioreactors (AMBRs) for the efficient and sustainable removal of dye from wastewater. This would contribute to the protection of ecosystems as well as the public's health.


Asunto(s)
Aguas Residuales , Contaminantes Químicos del Agua , Humanos , Colorantes/química , Microesferas , Ecosistema , Azul de Metileno/química , Contaminantes Químicos del Agua/química , Termodinámica , Adsorción , Cinética , Concentración de Iones de Hidrógeno , Espectroscopía Infrarroja por Transformada de Fourier
11.
Chemosphere ; 338: 139621, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37487973

RESUMEN

The earth's nitrogen cycle relies on the effective conversion of nitrogen (N2) to ammonia (NH3). As a result, the research and development of catalysts that are earth-abundant, inexpensive, and highly efficient but do not need precious metals is of the utmost significance. In this investigation, we present a controlled synthesis technique to the fabrication of an iron oxide (Fe2O3) nanosheet array by annealing at temperatures ranging from 350 to 550 °C. This array will be used for the electrochemical reduction of atmospheric N2 to NH3 in electrolytes. The Fe2O3 nanosheet array that was produced as a result displays outstanding electrochemical performance as well as remarkable stability. When compared to a hydrogen electrode working under normal temperature and pressure conditions, the Fe2O3 nanosheet array produces an impressive NH3 production rate of 18.04 g per hour per mg of catalytically active material in 0.1 M KOH electrolyte, exhibiting an enhanced Faradaic efficiency (FE) of 13.5% at -0.35 V. This is accomplished by exhibiting an enhanced Faradaic efficiency (FE) of 0.1 M KOH electrolyte. The results of experiments and electrochemical studies reveal that the existence of cation defects in the Fe2O3 nanosheets plays an essential part in the enhancement of the electrocatalytic activity that takes place during nitrogen reduction reactions (NRR). This study not only contributes to the expanding family of transition-metal-based catalysts with increased electrocatalytic activity for NRR, but it also represents a substantial breakthrough in the design of catalysts that are based on transition metals, so it's a win-win. In addition, the use of Fe2O3 nanosheets as electrocatalysts has a lot of potential in algal membrane bioreactors because it makes nitrogen fixation easier, it encourages algae growth, and it makes nitrogen cycling more resource-efficient.


Asunto(s)
Amoníaco , Reactores Biológicos , Estudios Prospectivos , Nitrógeno
12.
Polymers (Basel) ; 14(15)2022 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-35956720

RESUMEN

The latest advancements in cellulose and its derivatives are the subject of this study. We summarize the characteristics, modifications, applications, and properties of cellulose. Here, we discuss new breakthroughs in modified cellulose that allow for enhanced control. In addition to standard approaches, improvements in different techniques employed for cellulose and its derivatives are the subject of this review. The various strategies for synthetic polymers are also discussed. The recent advancements in polymer production allow for more precise control, and make it possible to make functional celluloses with better physical qualities. For sustainability and environmental preservation, the development of cellulose green processing is the most abundant renewable substance in nature. The discovery of cellulose disintegration opens up new possibilities for sustainable techniques. Based on the review of recent scientific literature, we believe that additional chemical units of cellulose solubility should be used. This evaluation will evaluate the sustainability of biomass and processing the greenness for the long term. It appears not only crucial to dissolution, but also to the greenness of any process.

13.
Pak J Biol Sci ; 10(22): 4140-3, 2007 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-19090295

RESUMEN

An experiment was conducted to investigate the effect of different growing media on the growth and development of Dahlia (Dahlia pinnata). Seven different growing media including sand, silt, leaf mold, sand + silt, sand + leaf mold, silt + leaf mold and sand + silt + leaf mold, were used to check the growth and development of dahlia in pots. The over all best performance was recorded in media sand + silt + leaf mold for almost all the parameters; plant height (42.08 cm), stem thickness (1.93 cm), number of branches per plant (3.6), minimum days to flowering (91.66), number of flowers per plant (10.6), number of petals per flower (13), diameter of flower (8.8 cm) and vase life of flower (5 days). The media leaf mold alone also performed significantly well for all the parameters including the maximum 42.55 leaves per plant. Sand, when used alone as a growing medium showed the least response and provided unsatisfactory results for all the parameters.


Asunto(s)
Medios de Cultivo/farmacología , Técnicas de Cultivo , Dahlia/crecimiento & desarrollo , Dahlia/fisiología , Clima , Flores , Pakistán , Hojas de la Planta/metabolismo , Fenómenos Fisiológicos de las Plantas , Raíces de Plantas/metabolismo , Tallos de la Planta/metabolismo , Dióxido de Silicio , Suelo , Factores de Tiempo
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