Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 64
Filtrar
Más filtros

Base de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
PLoS One ; 19(4): e0297534, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38635816

RESUMEN

The secret keys produced by current image cryptosystems, which rely on chaotic sequences, exhibit a direct correlation with the size of the image. As the image dimensions expand, the generation of extensive chaotic sequences in the encryption and decryption procedures becomes more computationally intensive. Secondly, a common problem in existing image encryption schemes is the compromise between privacy and efficiency. Some existing lightweight schemes reveal patterns in encrypted images, while others impose heavy computational burdens during encryption/decryption due to the need for large chaotic sequences. In this study, we introduce a lightweight image encryption scheme that involves partitioning the image into uniformly sized tiles and generating a chaotic sequence accordingly. This approach diminishes the necessity to create extensive chaotic sequences equal to the tile size, which is significantly smaller than the original image. As a result, it alleviates the processing burden associated with generating sequences equivalent to the original image size. The results confirm that our proposed scheme is lightweight and secure compared to the latest state-of-the-art image encryption schemes. Additionally, sensitivity analysis demonstrates that the proposed image encryption technique, with a UACI value of 33.48 and NPRC value of 99.96, affirms its resistance to differential attacks.


Asunto(s)
Privacidad , Resiliencia Psicológica
2.
PeerJ Comput Sci ; 10: e1949, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38660151

RESUMEN

Background: Computational intelligence (CI) based prediction models increase the efficient and effective utilization of resources for wind prediction. However, the traditional recurrent neural networks (RNN) are difficult to train on data having long-term temporal dependencies, thus susceptible to an inherent problem of vanishing gradient. This work proposed a method based on an advanced version of RNN known as long short-term memory (LSTM) architecture, which updates recurrent weights to overcome the vanishing gradient problem. This, in turn, improves training performance. Methods: The RNN model is developed based on stack LSTM and bidirectional LSTM. The parameters like mean absolute error (MAE), standard deviation error (SDE), and root mean squared error (RMSE) are utilized as performance measures for comparison with recent state-of-the-art techniques. Results: Results showed that the proposed technique outperformed the existing techniques in terms of RMSE and MAE against all the used wind farm datasets. Whereas, a reduction in SDE is observed for larger wind farm datasets. The proposed RNN approach performed better than the existing models despite fewer parameters. In addition, the approach requires minimum processing power to achieve compatible results.

3.
PLoS One ; 19(2): e0297056, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38315647

RESUMEN

This study evaluated the usability of a direct manipulation device (touchscreen) vs. indirect manipulation devices (mouse and touchpad) on the selected Microsoft (MS) Word tasks as per ISO-9241-11 standard. MS Word was taken as an example of a complex application. The tasks were evaluated in terms of touch-friendly or click-friendly using efficiency, effectiveness, and satisfaction parameters to propose a customized task menu. The experiment was conducted with fifty-four participants, divided into three MS Word usage-based expertise groups. Each participant performed fifty-six tasks using a mouse, a touchpad, and a touchscreen. To assess task-level usability, individual one-way ANOVAs were performed for each task to gauge both efficiency and effectiveness. It's worth noting that the touchscreen significantly outperformed other input methods in just one specific task regarding effectiveness. Consequently, an ANCOVA was employed, with task completion time as the independent variable and the number of errors as a covariate, to further investigate effectiveness. A total of 19 (34%) of the total tasks were found to be significantly efficient with a mouse, while 21 (37.5%) were significantly efficient with a touchscreen. Based on the results, a customized menu is recommended for MS Word-like applications that combine actions in touch-friendly tasks and mouse-friendly tasks separately.


Asunto(s)
Interfaz Usuario-Computador , Humanos , Análisis de Varianza
4.
J Relig Health ; 63(1): 466-489, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37978098

RESUMEN

This study investigates pilgrims' justifications for visiting Iran's Holy Shrine of Imam Reza (A.S) and the positive role of such pilgrimages in their religious coping experiences and healing practices. The research confirms that pilgrims strongly associate shrines in Iran with religious coping benefits and spiritual, mental, physical, and ritual healing. Data were collected using semi-structured interviews and purposive sampling. Behavioural strategies, religious beliefs, and spiritual concepts are considered. The findings reveal that faith and spirituality play a vital role in how individuals perceive and cope with mental and physical health issues when visiting shrines.


Asunto(s)
Salud Mental , Turismo , Humanos , Irán , Adaptación Psicológica , Espiritualidad
5.
ACS Omega ; 8(44): 41054-41063, 2023 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-37970029

RESUMEN

Poly(vinyl alcohol) (PVA), a naturally occurring and rapidly decomposing polymer, has gained significant attention in recent studies for its potential use in pollution preventive materials. Its cost-effectiveness and ease of availability as well as simple processing make it a suitable material for various applications. However, the only concern about PVA's applicability to various applications is its hydrophilic nature. To address this limitation, PVA-based nanocomposites can be created by incorporating inorganic fillers such as graphene (G). Graphene is a two-dimensional carbon crystal with a single atom-layer structure and has become a popular choice as a nanomaterial due to its outstanding properties. In this study, we present a simple and environmentally friendly solution processing technique to fabricate PVA and graphene-based nanocomposite films. The resulting composite films showed noticeable improvement in barrier properties against moisture, oxygen, heat, and mechanical failures. The improvement of the characteristic properties is attributed to the uniform dispersion of graphene in the PVA matrix as shown in the SEM image. The addition of graphene leads to a decrease in water vapor transmission rate (WVTR) by 79% and around 90% for the oxygen transmission rate (OTR) as compared to pristine PVA films. Notably, incorporating just 0.5 vol % of graphene results in an OTR value of as low as 0.7 cm m-2 day-1 bar-1, making it highly suitable packaging applications. The films also exhibit remarkable flexibility and retained almost the same WVTR values even after going through tough bending cycles of more than 2000 at a bending radius of 2.5 cm. Overall, PVA/G nanocomposite films offer promising potential for PVA/G composite films for various attractive pollution prevention (such as corrosion resistant coatings) and packaging applications.

6.
Sci Rep ; 13(1): 18664, 2023 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-37907578

RESUMEN

Brain metastasis in gastric cancer (GC) patients is a rare phenomenon that is associated with adverse clinical outcomes and poor survival rates. We conducted a retrospective cohort study to investigate the incidence, risk factors and prognostic factors of brain metastasis in GC patients. Data on sociodemographic and tumor characteristics of GC patients from 2010 to 2019 was extracted from the Surveillance, Epidemiology and End-Results (SEER) database. Descriptive statistics, multivariable logistic and Cox regression were applied on SPSS. Kaplan-Meier-Survival curves and ROC curves were constructed. A total of 59,231 GC patients, aged 66.65 ± 13.410 years were included. Brain metastasis was reported in 368 (0.62%) patients. On logistic regression, the risk of brain metastasis was significantly greater in males, patients aged < 60 years and patients having concurrent bone and lung metastasis. High grade and high N stage were significant risk factors for development of brain metastasis. Patients who had undergone surgery for the primary tumor were at reduced risk for brain metastasis (adjusted odds ratio 0.210, 95% CI 0.131-0.337). The median OS was 3 months in patients with brain metastasis and 17 months in patients without brain metastasis (p < 0.05). On Cox regression, Grade IV tumors and primary antral tumors were significant predictable parameters for poor prognosis. Overall Survival (OS) and Cancer-Specific Survival (CSS) were prolonged in patients who had undergone surgery. Brain metastasis in gastric cancer is associated with significantly worse survival. Employing large-scale screening for high-risk patients holds a promising impact to improve survival rates, but it must be accurately balanced with a comprehensive understanding of clinicopathological aspects for accurate diagnosis and treatment.


Asunto(s)
Neoplasias Encefálicas , Neoplasias Gástricas , Masculino , Humanos , Femenino , Pronóstico , Neoplasias Gástricas/patología , Estudios Retrospectivos , Programa de VERF , Factores de Riesgo , Neoplasias Encefálicas/epidemiología , Neoplasias Encefálicas/secundario
7.
Adv Mater ; : e2306920, 2023 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-37905890

RESUMEN

Since the emergence of 2D magnets in 2017, the diversity of these materials has greatly expanded. Their 2D nature (atomic-scale thickness) endows these magnets with strong magnetic anisotropy, layer-dependent and switchable magnetic order, and quantum-confined quasiparticles, which distinguish them from conventional 3D magnetic materials. Moreover, the 2D geometry facilitates light incidence for opto-spintronic applications and potential on-chip integration. In analogy to optoelectronics based on optical-electronic interactions, opto-spintronics use light-spin interactions to process spin information stored in the solid state. In this review, opto-spintronics is divided into three types with respect to the wavelengths of radiation interacting with 2D magnets: 1) GHz (microwave) to THz (mid-infrared), 2) visible, and 3) UV to X-rays. It is focused on the recent research advancements on the newly discovered mechanisms of light-spin interactions in 2D magnets and introduces the potential design of novel opto-spintronic applications based on these interactions.

8.
Pak J Pharm Sci ; 36(4): 1085-1088, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37599482

RESUMEN

Type 1 diabetes is a growing metabolic disorder, its ultimate therapy is the use of taking insulin regularly but, despite of that these patients cannot survive for longer durations due to poor glycaemic control, insulin resistance and development of complications. This clinical trial was designed to see if the addition of metformin can affect the dose of insulin and its complications and conducted for three months in Baqai Institute of Diabetology and Endocrinology. It included 80 patients of Type 1 Diabetes above 12 years of age between April 2019 to March 2020. Patients were divided into two groups. Group 1(n=30) was given Metformin with insulin and in Group 2 (n=50) patients were prescribed insulin only. Blood samples were collected at the beginning and end of trial to check Fasting and Random blood glucose and HbA1c levels. Paired sample t test and independent t test were applied, p value 0.05 was considered significant. A significant difference in HbA1c (p<0.001) and Random Blood Glucose (p=0.006) was noticed in group 1after three months. BMI increased in group 2, (p=0.024). The study concludes that Metformin might have a role in decreasing HbA1c and Random blood glucose levels in children above 12 years of age.


Asunto(s)
Diabetes Mellitus Tipo 1 , Metformina , Adolescente , Niño , Humanos , Glucemia , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Hemoglobina Glucada , Insulina/uso terapéutico , Metformina/uso terapéutico
9.
ACS Omega ; 8(32): 28976-28983, 2023 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-37599914

RESUMEN

This investigation aims at synthesizing and characterizing a biocomposite of hydroxyapatite (HA) and titanium (Ti) as a functionally graded material (FGM) via an economical powder metallurgy route. Ti particles were produced through drilling and chipping, followed by compaction and sintering. Ti foams, so obtained, were then infused with varying volume fractions of HA. The pure Ti foam control sample and the FGM composite samples were then subjected to various characterizations to validate their biocompatibility, structural strength, and integrity. The interface development between the load-bearing Ti implant and living tissue was resolved through an FGM structure, where the base of the implant consisted of load-bearing Ti and the outer periphery changed to HA gradually. HA/Ti specimens of different volume fractions were tested for density measurements, microstructure, hardness, and bioactivity. The bioactive behavior was investigated using the potentiodynamic polarization technique to measure the corrosion rate of the pure Ti foam (0/100 HA/Ti) and the FGM composite (10/90 HA/Ti) samples in a simulated body fluid (SBF). The results showed that the hardness of FGM composites, despite being less than that of 0/100 HA/Ti, was still within safe limits. The corrosion rate, however, was found to be decreased by a significant value of almost 40% for the 10/90 HA/Ti FGM composite sample compared to the pure Ti foam control sample. It was concluded that the optimum composition 10/90 HA/Ti sample offers improved corrosion resistance while maintaining a sufficient allowable hardness level.

11.
Pak J Med Sci ; 39(3): 880-884, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37250546

RESUMEN

Objective: To correlate the serum levels of ceruloplasmin (Cp), copper (Cu), and superoxide dismutase (SOD) with pulmonary function tests (PFTs) in non-diabetics (controls) and patients suffering from Type-1 and Type- 2 diabetes. Methods: The comparative cross-sectional study of 348 participants was performed at the Baqai Institute of Diabetes and Endocrinology (BIDE) - Karachi, Pakistan, from February 2019 to September 2020. Individuals having diabetes-related complications, asthma, chronic obstructive pulmonary disease, chest infection, pregnant women and smokers were excluded. A total of 348 participants were included into three groups after signing informed consent. The control group had 107 non-diabetic participants, with an age range of 6 to 60 years. The diagnosed T1D group (n=107) had an age range of 6 to 25 years. While diagnosed T2D group (n=134) had an age range of 26 to 60 years. During the fasting state, anthropometric parameters, blood pressure, spirometry, and a venous blood sample (5ml) were collected to measure serum Cp, serum Cu, serum SOD, and HbA1c levels by using commercially available kits. The SPSS, version 21, was used for data analysis. Results: The reduced FVC (p-value <0.001), FEV1 (p-value <0.001), and PEFR (p-value <0.001) were found in both groups of diabetes. However, the lower levels of serum Cu (p-value <0.001), SOD (p-value <0.001), and significantly increased values of FEV1/ FVC (p-value <0.001) and Cp levels (p-value 0.030) were found only in T2D group as compared to T1D and controls. The study found no significant correlation of PFTs and serum Cp, Cu, and SOD levels in patients suffering from T1D and T2D. Conclusion: Hyperglycemia leads to more non-enzymatic glycosylation of tissue proteins that reflects reduced PFTs and increased Cp; particularly in T2D, which may alter lung tissue's physiology. Moreover, the study showed no correlation of PFTs with the Cp, Cu, and SOD in patients suffering from T1D and T2D.

12.
Math Biosci Eng ; 20(5): 8208-8225, 2023 02 27.
Artículo en Inglés | MEDLINE | ID: mdl-37161193

RESUMEN

Facial expression is a type of communication and is useful in many areas of computer vision, including intelligent visual surveillance, human-robot interaction and human behavior analysis. A deep learning approach is presented to classify happy, sad, angry, fearful, contemptuous, surprised and disgusted expressions. Accurate detection and classification of human facial expression is a critical task in image processing due to the inconsistencies amid the complexity, including change in illumination, occlusion, noise and the over-fitting problem. A stacked sparse auto-encoder for facial expression recognition (SSAE-FER) is used for unsupervised pre-training and supervised fine-tuning. SSAE-FER automatically extracts features from input images, and the softmax classifier is used to classify the expressions. Our method achieved an accuracy of 92.50% on the JAFFE dataset and 99.30% on the CK+ dataset. SSAE-FER performs well compared to the other comparative methods in the same domain.


Asunto(s)
Aprendizaje Profundo , Reconocimiento Facial , Humanos , Comunicación , Miedo , Procesamiento de Imagen Asistido por Computador
13.
J Pak Med Assoc ; 73(2): 313-318, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36800717

RESUMEN

Objective: To evaluate the impact of hepcidin and ferritin in pathogenesis and prognosis of type 2 diabetes mellitus subjects taking only metformin or combined anti-glycaemic agents. METHODS: The observational case-control study was conducted at the Department of Physiology, Baqai Medical University, Karachi, from August 2019 to October 2020, and comprised subjects from both genders who categorised into equal groups as non-diabetic controls, newly-diagnosed type 2 diabetes mellitus patients without any treatment, type 2 diabetes mellitus patients with exposure to metformin only, type 2 diabetes mellitus patients taking oral hypoglycaemic agents along with metformin, type 2 diabetes mellitus patients taking only insulin, and type 2 diabetes mellitus patients taking insulin and oral hypoglycaemic agents. Fasting plasma glucose was determined using glucose oxidase-peroxidase method, glycated haemoglobin by high performance liquid chromatography, high-density lipoprotein and low-density lipoprotein by direct methods, cholesterol by cholesterol oxidase phenol 4-amino antipyrine peroxidase and triglycerides by glycerol phosphate oxidase-phenol 4-amino antipyrine peroxidase method. Serum levels of ferritin, insulin and hepcidin were evaluated using Enzyme-linked immunosorbent assay. Insulin resistance was assessed using homeostasis model assessment for insulin resistance. Data was analysed using SPSS 21. RESULTS: Of the 300 subjects, there were 50(16.66%) in each of the 6 groups. Overall, there were 144(48%) males and 155(51.66%) females. The mean age was significantly lower in the control group 34.72±7.87 compared to all the diabetic groups (p<0.05), and the same was the case with respect to all the parameters (p<0.05) except high-density lipoprotein (p>0.05). Besides, hepcidin level was significantly higher in the control group (p<0.05). Ferritin levels were significantly increased in newly-diagnosed T2DM subjects compared to the controls (p<0.05) while all other groups showed decreased ferritin levels (p<0.05). Hepcidin gave inverse correlation with glycated haemoglobin only in diabetics taking only metformin (r = -0.27, p=0.05). CONCLUSIONS: Anti-diabetes drugs not only addressed type 2 diabetes mellitus, but also reduced levels of ferritin and hepcidin that are found to play a role in diabetes development.


Asunto(s)
Diabetes Mellitus Tipo 2 , Resistencia a la Insulina , Metformina , Humanos , Femenino , Masculino , Metformina/uso terapéutico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hepcidinas , Estudios de Casos y Controles , Hemoglobina Glucada , Pakistán , Hipoglucemiantes/uso terapéutico , Insulina , Peroxidasas
14.
Polymers (Basel) ; 14(22)2022 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-36433147

RESUMEN

Starch and gelatin are natural biopolymers that offer a variety of benefits and are available at relatively low costs. In addition to this, they are an appealing substitute for synthetic polymers for the manufacturing of packaging films. Such packaging films are not only biodegradable but are also edible. Moreover, they are environmentally friendly and remain extremely cost-effective. In lieu of this, films made from fish gelatin and cornstarch have been the subject of several experiments. The pristine gelatin films have poor performance against water diffusion but exhibit excellent flexibility. The goal of this study was to assess the performance of pristine gelatin films along with the addition of food plasticizers. For this purpose, solutions of gelatin/cornstarch were prepared and specified quantities of food colors/plasticizers were added to develop different shades. The films were produced by using a blade coating method and were characterized by means of their shaded colors, water vapor transmission rate (WVTR), compositional changes via Fourier transform infrared spectroscopy (FTIR), hardness, bendability, transparency, wettability, surface roughness, and thermal stability. It was observed that the addition of several food colors enhanced the moisture blocking effect, as a 10% reduction in WVTR was observed in the shaded films as compared to pristine films. The yellow-shaded films exhibited the lowest WVTR, i.e., around 73 g/m2·day when tested at 23 °C/65%RH. It was also observed that the films' WVTR, moisture content, and thickness were altered when different colors were added into them, although the chemical structure remained unchanged. The mechanical properties of the shaded films were improved by a factor of two after the addition of colored plasticizers. Optical examination and AFM demonstrated that the generated films had no fractures and were homogeneous, clear, and shiny. Finally, a biscuit was packaged in the developed films and was monitored via shore hardness. It was observed that the edible packed sample's hardness remained constant even after 5 days. This clearly suggested that the developed films have the potential to be used for packaging in various industries.

15.
ACS Omega ; 7(46): 42313-42319, 2022 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-36440109

RESUMEN

AISI 1045 medium carbon steel sheets having 10 mm thickness were subjected to the shielded metal arc welding process with three, five, and seven passes. The variations in the microstructure due to multiple thermal cycles in the heat-affected zone (HAZ), base metal (BM), and fusion zone (FZ) have been investigated and correlated with measured mechanical properties. Upon comparing fracture mechanics and mechanical properties with microstructural observations, it is elucidated that samples become ductile by increasing the number of thermal cycles which can be attributed to the transformations in the ferrite morphology in the HAZ. Based on mechanical, microstructural, and fracture analysis, it is concluded that post-weld heat treatment can be avoided if the number of passes during welding is increased.

16.
Materials (Basel) ; 15(21)2022 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-36363347

RESUMEN

Natural soil (NS)-based geopolymers (GPs) have shown promise as environmentally friendly construction materials. The production of ordinary Portland cement is known to release significant amounts of greenhouse gas (CO2) into the atmosphere. The main objective of this work is to synthesize a geopolymer (GP) from an uncommon aluminosilicate-based NS and a sodium silicate (SS) activating solution that would not only minimize the emission of harmful gases, but also offer improved mechanical strength. Samples of different compositions were produced by varying the wt.% of NS from 50% to 80% and adding a balancing amount of SS solution. The drying and curing of the samples were carried out in an electric oven at specific temperatures. The degree of geopolymerization in the samples was measured by Fourier transform infrared spectroscopy, and microstructural analysis was performed using a scanning electron microscope. Mechanical tests were conducted to evaluate the range of compressive strength values of the prepared GP samples. A minimum compressive strength of 10.93 MPa at a maximum porosity of 37.56% was observed in a sample with an NS to SS ratio of 1:1; while a ratio of 3:1 led to the maximum compressive strength of 26.39 MPa and the minimum porosity of 24.60%. The maximum strength (26.39 MPa) was found to be more than the reported strength values for similar systems. Moreover, an improvement in strength by a factor of three has been observed relative to previously developed NS-based GPs. It may be inferred from the findings that for the given NS, with almost 90% aluminosilicate content, the extent of geopolymerization increases significantly with its increasing proportions, yielding better mechanical strength.

17.
Nanomaterials (Basel) ; 12(21)2022 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-36364695

RESUMEN

Aluminum nitride (AlN) is a semiconductor material possessing a hexagonal wurtzite crystal structure with a large band gap of 6.2 eV. AlN thin films have several potential applications and areas for study, particularly in optoelectronics. This research study focused on the preparation of Ni-doped AlN thin films by using DC and RF magnetron sputtering for optoelectronic applications. Additionally, a comparative analysis was also carried out on the as-deposited and annealed thin films. Several spectroscopy and microscopy techniques were considered for the characterization of structural (X-ray diffraction), morphological (SEM), chemical bonding (FTIR), and emission (PL spectroscopy) properties. The XRD results show that the thin films have an oriented c-axis hexagonal structure. SEM analysis validated the granular-like morphology of the deposited sample, and FTIR results confirm the presence of chemical bonding in deposited thin films. The photoluminescence (PL) emission spectra exhibit different peaks in the visible region when excited at different wavelengths. A sharp and intense photoluminescence peak was observed at 426 nm in the violet-blue region, which can be attributed to inter-band transitions due to the incorporation of Ni in AlN. Most of the peaks in the PL spectra occurred due to direct-band recombination and indirect impurity-band recombination. After annealing, the intensity of all observed peaks increases drastically due to the development of new phases, resulting in a decrease in defects and a corresponding increase in the crystallinity of the thin film. The observed structural, morphological, and photoluminescence results suggest that Ni: AlN is a promising candidate to be used in optoelectronics applications, specifically in photovoltaic devices and lasers.

18.
Nanotechnology ; 34(3)2022 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-36215879

RESUMEN

In this study, we have investigated the role of natural dead sea sponge (DSS, Porifera) as a three-dimensional (3D) porous host substrate for the immobilization of nanostructured ZnO material towards the development of ZnO based floating photocatalysts for efficient removal of methylene blue (MB) dye under the illumination of sunlight. After photodegradation, the treated water after dye degradation contains several pathogens, different disinfectants or chemical reagents that are essentially used. This is not the case for DSS as it can naturally kill any pathogens during the wastewater treatment process. To explore these functions, ZnO nanosheets were incorporated onto DSS via hydrothermal protocol and the as prepared ZnO/DSS hybrid material exhibited approximately âˆ¼100% degradation efficiency for the removal of MB. Importantly, the degradation kinetics associated with the fabricated ZnO/DSS was remarkably accelerated as evidenced by the high values of degradation reaction rate constants (3.35 × 10-2min-1). The outperformance of ZnO/DSS could be attributed to the adsorption caused by its 3D porous structure together with the high rapid oxidation of MB. Furthermore, the high charge separation of electron-hole pairs, natural porosity, and abundant catalytic sites offered by the hybrid ZnO/DSS floating photocatalyst have enabled quantitative (∼100%) degradation efficiency for MB. Finally, the excellent reusability results confirm the feasibility of using natural ZnO/DSS-based photocatalyst for practical solution of wastewater treatment and other environmental problems.


Asunto(s)
Óxido de Zinc , Óxido de Zinc/química , Desinfección , Catálisis , Fotólisis , Azul de Metileno/química
19.
Nanomaterials (Basel) ; 12(20)2022 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-36296761

RESUMEN

Wastewater from the textile industry is chronic and hazardous for the human body due to the presence of a variety of organic dyes; therefore, its complete treatment requires efficient, simple, and low cost technology. For this purpose, we grew ZnO microstructures in the presence of psyllium husk, and the role of psyllium husk was to modify the surface of the ZnO microstructures, create defects in the semiconducting crystal structures, and to alter the morphology of the nanostructured material. The growth process involved a hydrothermal method followed by calcination in air. Additionally, the psyllium husk, after thermal combustion, added a certain value of carbon into the ZnO nanomaterial, consequently enhancing the photocatalytic activity towards the degradation of methylene blue. We also investigated the effect of varying doses of photocatalyst on the photocatalytic properties towards the photodegradation of methylene blue in aqueous solution under the illumination of ultraviolet light. The structure and morphology of the prepared ZnO microstructures were explored by scanning electron microscopy (SEM) and powder X-ray diffraction (XRD) techniques. The degradation of methylene blue was monitored under the irradiation of ultraviolet light and in the dark. Also, the degradation of methylene blue was measured with and without photocatalyst. The photodegradation of methylene blue is highly increased using the ZnO sample prepared with psyllium husk. The photodegradation efficiency is found to be approximately 99.35% for this sample. The outperforming functionality of psyllium-husk-assisted ZnO sample is attributed to large surface area of carbon material from the psyllium husk and the synergetic effect between the incorporated carbon and ZnO itself. Based on the performance of the hybrid material, it is safe to say that psyllium husk has high potential for use where surface roughness, morphology alteration, and defects in the crystal structure are vital for the enhancing the functionality of a nanostructured material. The observed performance of ZnO in the presence of psyllium husk provides evidence for the fabrication of a low cost and efficient photocatalyst for the wastewater treatment problems.

20.
Gels ; 8(10)2022 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-36286177

RESUMEN

Hydrogels can provide instant relief to pain and facilitate the fast recovery of wounds. Currently, the incorporation of medicinal herbs/plants in polymer matrix is being investigated due to their anti-bacterial and wound healing properties. Herein, we investigated the novel combination of chitosan (CS) and chondroitin sulfate (CHI) to synthesize hydrogels through freeze gelation process and enriched it with garlic (Gar) by soaking the hydrogels in garlic juice for faster wound healing and resistance to microbial growth at the wound surface. The synthesized hydrogels were characterized via Fourier-transform infrared spectroscopy (FTIR), which confirmed the presence of relevant functional groups. The scanning electron microscopy (SEM) images exhibited the porous structure of the hydrogels, which is useful for the sustained release of Gar from the hydrogels. The synthesized hydrogels showed significant inhibition zones against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Furthermore, cell culture studies confirmed the cyto-compatibility of the synthesized hydrogels. Thus, the novel hydrogels presented in this study can offer an antibacterial effect during wound healing and promote tissue regeneration.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA