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1.
Nurs Ethics ; 31(5): 951-979, 2024 08.
Artículo en Inglés | MEDLINE | ID: mdl-38113636

RESUMEN

BACKGROUND: Respectful maternity care (RMC) emphasizes the social and relational elements of maternity care and is a crucial part of initiatives to improve service accessibility and quality. Women's perceptions have influenced much of what we know about RMC and contempt in the labor ward. In order to understand midwives' perspectives of RMC, this meta-synthesis focused on them. METHOD: For this inquiry, the databases PubMed/Medline, Embase, Web of Science, and Scopus were searched to find studies on midwives' perceptions of RMC written between 2011 and April 20th 2023. The included articles were to English language restriction. The results of the included research were examined using thematic analysis. Using the inclusion criteria, 84 potentially relevant articles were carefully reviewed, and only 22 were ultimately selected for synthesis. The quality of the qualitative study was assessed using the CASP, a tool for quality evaluation and PRISMA guidelines were followed. Using the MAXQDA program, the cited quotes and the original authors' interpretations were combined. RESULT: There were 22 studies total, thematic synthesis was determined to be appropriate for a total of 22 research studies. Following are the topics which we summarized our analysis: in six major themes: Midwives' conceptualizations of RMC, Midwives commitment to woman's rights, The value and impact of RMC to midwives, Midwife's perception of disrespectful care, Challenges in providing respectful maternity care, and Midwives' recommendations for optimal RMC practice. CONCLUSION: In addition to specific focus on promoting cooperation, policies to enhance health systems and strategic consideration of the midwifery profession's future are required.


Asunto(s)
Servicios de Salud Materna , Respeto , Humanos , Servicios de Salud Materna/normas , Femenino , Embarazo , Enfermeras Obstetrices/psicología , Enfermeras Obstetrices/normas , Investigación Cualitativa , Partería/normas , Actitud del Personal de Salud , Salud Global/normas
2.
Med J Islam Repub Iran ; 38: 35, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38978797

RESUMEN

Background: A wide variety of electrocardiogram (ECG) changes can manifest with antidepressant drugs, occurring at both therapeutic doses and toxic levels. Notably, ECG abnormalities like wide QRS and QT prolongation may be observed in poisoned patients with tricyclic antidepressants (TCAs), indicating severe conditions that necessitate the implementation of cardiac monitoring systems. This study aimed to investigate ECG Abnormality in poisoned patients with tricyclic antidepressants. Methods: This retrospective patient record study was conducted at Razi Hospital in Ahvaz, Iran, from 2006 to 2009. Patient information was extracted from hospital medical records after the established protocol. The chi-square test was employed for initial analysis; subsequently, logistic regression was applied to identify risk factors associated with abnormal ECG findings. We analyzed the data using SPSS (Version 19; IBM) statistical software. P < 0.05 was defined as statistically significant. Results: Among the 210 poisoned patients, comprising 88 men (41.9%) and 122 women (58.1%), the majority fell within the age range of 15 to 25 years. In our study, the most commonly ingested drugs by poisoned patients were amitriptyline in 134 patients (63.8%) and nortriptyline in 42 patients (20%). A significant portion of 137 patients (65.2%) exhibited poisoning symptoms within ˂ 6 hours, while 73 patients (34.8%) showed symptoms between 6 and 24 hours. Our findings indicated that the initial symptoms in poisoned patients included a decreased level of consciousness in 168 patients (80%), nausea and vomiting in 20 patients (9.5%), and various other symptoms. Notably, our results revealed ECG changes in 70 patients, with 32 patients (15.2%) showing a QRS widening (> 0.1sec), 5 patients (2.4%) displaying a tall R wave in aVR, 5 patients (2.4%) exhibiting right axis deviation, and other observed changes. Conclusion: QRS widening in poisoned patients with tricyclic antidepressants is more frequently observed in symptomatic patients, highlighting the importance of ECG screening in these patients.

3.
Environ Res ; 216(Pt 1): 114436, 2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-36183791

RESUMEN

Agro-waste having lignocellulosic biomass is considered most effective (heating value 16 MJ/kg) for energy production through anaerobic digestion (AD). However, recalcitrant lignocellulosic fraction in agro-waste obstructs its biotransformation and is a rate-limiting step of the process. This study investigated the effects of hydrothermal and thermal-alkaline pretreatment on anaerobic co-digestion of wheat straw (WS). The hydrothermal pretreatment of WS revealed that 60 min was the best pretreatment time to achieve the highest substrate solubilization. It was employed for thermal-alkali pretreatment at variable temperatures and NaOH doses. Thermal-alkali pretreatment at 125°C-7% NaOH shows the highest (34%) biogas yield of 662 mL/gVS, followed by 646 mL/gVS biogas yield at 150°C-1% NaOH assay (31% higher) over control. Although the 125°C-7% NaOH assay achieved the highest biogas yield, the 150°C-1% NaOH assay was found more feasible considering the cost of a 6% higher chemical used in the earlier assay. The thermal-alkali pretreatment was observed to reduce the formation of recalcitrant compounds (HMF, Furfural) and increase the buffering capacity of the slurry over hydrothermal pretreatment. Principal component analysis (PCA) of the various pretreatment and AD operational parameters was carried out to study their in-depth correlation. Moreover, a kinetic study of the experimental data was performed to observe the biodegradation trend and compare it with the Modified Gompertz (MG) and First Order (FO) models.


Asunto(s)
Biocombustibles , Triticum , Triticum/química , Anaerobiosis , Álcalis , Metano , Hidróxido de Sodio , Digestión
4.
Environ Res ; 212(Pt C): 113382, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35568237

RESUMEN

In this study, four batch assays were performed to ensure the synergic effects of co-digestion and find out the best inoculums to substrate ratio (ISR), carbon to nitrogen ratio (C:N), and total solid (TS) percentage in sequence. The co-digestion of three feedstocks had a 20% higher biogas yield (416 mL/gVS added) than mono-digestion with 21% volatile solids (VS) degradation. The ISR of 2 leads to the highest biogas yield (431 mL/gVS added) and VS removal (30.3%) over other ISRs (0.5, 1.0, 2.5) studied. The lower ISR (<2) tended to have lower pH due to insufficient anaerobes inside the digester. The C:N 35 (with ISR 2) yielded 17.4% higher biogas (443.5 mL/gVS added) than mono-digestion and was the highest among the C:N ratios studied with 36.6% VS removal. The VFA, alkalinity, and pH in C:N 35 assay were more stable than in other C:N assays. In the fourth batch assay, varying TS% (5, 7.5, 10, 12.5) were used with optimized ISR (2) and C:N (35). Higher TS% (10 and 12.5) had some lag phase but later achieved higher biogas production. The 12.5% TS assay achieved 80% higher biogas yield (679 mL/gVS added) over mono-digestion, i.e., highest among the TS% studied, with 48% VS removal. In conclusion, co-digestion of mixed feedstocks with ISR 2, C:N 35, and TS 12.5% could degrade almost half of the substrate available for biodegradation. Further biodegradation may require pretreatment of the recalcitrant WS. Modified Gompertz, first-order, transference, and logistic models were used for kinetic study and curve fitting of experimental data. For the optimized batch assays, the estimated specific rate constants were 0.08, 0.12, 0.083, and 0.084. The data fits well in all the models, with the coefficient of discrimination (R2) ranging from 0.882 to 0.999.


Asunto(s)
Biocombustibles , Eliminación de Residuos , Anaerobiosis , Animales , Reactores Biológicos , Bovinos , Digestión , Alimentos , Estiércol , Metano , Triticum
5.
J Cell Biochem ; 121(4): 2818-2827, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31692062

RESUMEN

The purpose of this study was to investigate miR-7 overexpression effects on neural differentiation of mesenchymal stem cells (MSCs) on both two-dimensional (2D) and three-dimensional (3D) culture systems. We upregulated miR-7 through lentiviral vector in trabecular meshwork MSCs (TMMSCs) and polymers of poly l-lactic acid/polycaprolactone fibrous scaffold were fabricated by electrospinning and characterized using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR). Neural markers expression was evaluated through quantitative-polymerase chain reaction (q-PCR) and immunostaining. The results showed that the high percentage of cell transduction (84.9%) and miR-7 expression (folds: 677.93 and 556.4) was detected in TMMSCs-miR-7(+). SEM and FTIR established the fabrication of the hybrid scaffold. q-PCR analysis showed that on days 14 and 21 of transduction, the expression level of Nestin and glial fibrillary acidic protein (GFAP) genes were significantly higher in the scaffold (3D) compared with tissue culture polystyrene (2D) culture. The expression of microtubule-associated protein-2 (MAP-2) and GFAP genes in TMMSCs-miR-7(+) cells were significantly higher than those miR-7(-) cells after 21 days of cell culture. Also, MAP-2 and Nestin proteins were detected in TMMSCs-miR-7(+) cells. Our results demonstrate that miR-7 is involved in neural differentiation of TMMSCs and scaffold can improve differentiate into glial and neural progenitor cells. These findings provided some information for future use of microRNAs and scaffold in tissue engineering and cell therapy for neurological diseases.


Asunto(s)
Células Madre Mesenquimatosas/citología , MicroARNs/metabolismo , Malla Trabecular/metabolismo , Diferenciación Celular , Perfilación de la Expresión Génica , Proteína Ácida Fibrilar de la Glía/metabolismo , Células HEK293 , Humanos , Lentivirus/metabolismo , Microscopía Electrónica de Rastreo , Nanofibras , Nestina/metabolismo , Neuronas/metabolismo , Plásmidos/metabolismo , Poliésteres/química , Poliestirenos/química , Espectroscopía Infrarroja por Transformada de Fourier
6.
Biochem Biophys Res Commun ; 529(3): 526-532, 2020 08 27.
Artículo en Inglés | MEDLINE | ID: mdl-32736669

RESUMEN

MiRNAs are small non-coding RNAs that are ordinarily involved in modulating mRNAs and stem cell differentiation. 3D nanofibrous scaffolds have an important role in the differentiation of stem cells due to their similarity to the extracellular matrix (ECM). In the present study, we tried to introduce a new approach to guiding the differentiation of conjunctiva mesenchymal stem cells (CJMSCs) into photoreceptor-like cells by hsa-miR-9-1 delivery on both 2D and 3D substrates. First, the CJMSCs were transduced by a lentiviral vector carrying miR-9 (pCDH + hsa-miR-9-1) and then cell transduction efficacy verified by using fluorescent microscopy, flow cytometry, and qPCR analyses. Silk Fibroin-poly-L-lactic acid (SF-PLLA) scaffold was fabricated by the electrospinning technique while the scaffold characteristics including morphology, chemical properties, and biocompatibility were evaluated by SEM, FTIR, and MTT assays, respectively. Then, the miR-9-CJMSCs were seeded on both TCPS and the scaffold; photoreceptor gene and protein expressions were evaluated by RT-qPCR and immunostaining after 14 and 21 days of transduction. More than 80% of CJMSCs were transduced and miR-9 expression was significantly higher in miR-9-CJMSCs compared with empty vector (EV)-CJMSCs. SEM and FTIR confirmed the fabrication of the SF/PLLA hybrid structure. RT-qPCR and immunostaining analyses showed that the specific photoreceptor genes and proteins were expressed in miR-9 transduced CJMSCs. Mir-9 induced CJMSCs into photoreceptor-like cells in a time-dependent manneron on both TCPS and nanofibrous scaffold.We have proved that hsa-miR-9-1 has the potency to guide the photoreceptor differentiation of mesenchymal stem cells and promote retinal regeneration.


Asunto(s)
Diferenciación Celular/genética , Células Madre Mesenquimatosas/metabolismo , MicroARNs/genética , Nanofibras/química , Células Fotorreceptoras de Vertebrados/metabolismo , Andamios del Tejido/química , Células Cultivadas , Conjuntiva/citología , Fibroínas/química , Regulación de la Expresión Génica , Humanos , Células Madre Mesenquimatosas/citología , Microscopía Electrónica de Rastreo , Microscopía Fluorescente , Nanofibras/ultraestructura , Células Fotorreceptoras de Vertebrados/citología , Poliésteres/química , Factores de Tiempo , Ingeniería de Tejidos/métodos
7.
J Cell Physiol ; 234(5): 6801-6809, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30317587

RESUMEN

Tissue and stem cell encapsulation andtransplantation were considered as promising tools in the treatment of patients with diabetes mellitus. The aim of this study was to evaluate the effect of microfluidic encapsulation on the differentiation of trabecular meshwork mesenchymal stem cells (TM-MSC), into insulin-producing cells (IPCs) both in vitro and in vivo. The presence of differentiated cells in microfibers (three dimensional [3D]) and tissue culture plates (TCPS; two dimensional [2D]) culture was evaluated by detecting mRNA and protein expression of pancreatic islet-specific markers as well as measuring insulin release of cells in response to glucose challenges. Finally, semi-differentiated cells in microfibers (3D) and 2D cultures were used to control the glucose level in diabetic rats. The results of this study showed that MSCs differentiated in alginate microfibers (fabricated by microfluidic device) express more Pdx-1 mRNA (1.938-fold, p-value: 0.0425) and Insulin mRNA (2.841-fold, p-value: 0.0001) compared with those cultured on TCPS. Furthermore, cell encapsulation in microfluidic derived microfibers decreased the level of blood glucose in diabetic rats. The approach used in this study showed the possibility of alginate microfibers as a matrix for differentiation of TM-MSCs (as a new source) into IPCs. In addition, it could minimize different steps in stem cell differentiation, handling, and encapsulation, which lead to loss of an unlimited number of cells.


Asunto(s)
Diferenciación Celular/fisiología , Diabetes Mellitus Experimental/patología , Células Secretoras de Insulina/fisiología , Células Madre Mesenquimatosas/fisiología , Malla Trabecular/fisiología , Animales , Glucemia/metabolismo , Células Cultivadas , Diabetes Mellitus Experimental/metabolismo , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Células Madre Mesenquimatosas/metabolismo , Microfluídica/métodos , ARN Mensajero/metabolismo , Ratas , Malla Trabecular/metabolismo
8.
Artif Organs ; 43(8): 780-790, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30674064

RESUMEN

An electrical stimulus is a new approach to neural differentiation of stem cells. In this work, the neural differentiation of conjunctiva mesenchymal stem cells (CJMSCs) on a new 3D conductive fibrous scaffold of silk fibroin (SF) and reduced graphene oxide (rGo) were examined. rGo (3.5% w/w) was dispersed in SF-acid formic solution (10% w/v) and conductive nanofibrous scaffold was fabricated using the electrospinning method. SEM and TEM microscopies were used for fibrous scaffold characterization. CJMSCs were cultured on the scaffold and 2 electrical impulse models (Current 1:115 V/m, 100-Hz frequency and current 2:115 v/m voltages, 0.1-Hz frequency) were applied for 7 days. Also, the effect of the fibrous scaffold and electrical impulses on cell viability and neural gene expression were examined using MTT assay and qPCR analysis. Fibrous scaffold with the 220 ± 20 nm diameter and good dispersion of graphene nanosheets at the surface of nanofibers were fabricated. The MTT result showed the viability of cells on the scaffold, with current 2 lower than current 1. qPCR analysis confirmed that the expression of ß-tubulin (2.4-fold P ≤ 0.026), MAP-2 (1.48-fold; P ≤ 0.03), and nestin (1.5-fold; P ≤ 0.03) genes were higher in CJMSCs on conductive scaffold with 100-Hz frequency compared to 0.1-Hz frequency. Collectively, we proposed that SF-rGo fibrous scaffolds, as a new conductive fibrous scaffold with electrical stimulation are good strategies for neural differentiation of stem cells and the type of electrical pulses has an influence on neural differentiation and proliferation of CJMSCs.


Asunto(s)
Conjuntiva/citología , Células Madre Mesenquimatosas/citología , Neurogénesis , Ingeniería de Tejidos/instrumentación , Andamios del Tejido/química , Animales , Reactores Biológicos , Bombyx/química , Células Cultivadas , Conductividad Eléctrica , Estimulación Eléctrica/instrumentación , Diseño de Equipo , Fibroínas/química , Humanos , Nanofibras/química , Nanofibras/ultraestructura
9.
Biologicals ; 62: 33-38, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31635936

RESUMEN

Polymers are used in tissue engineering as a scaffold. In this study the differentiation capability of conjunctiva mesenchymal stem cells (CJMSCs) on natural and synthetic nanofibrous electrospun scaffolds into insulin producing cells (IPCs) were studied. Natural Silk fibroin and synthetic PLLA polymers were used to fabricate electrospun scaffolds. These scaffolds are characterized by SEM and CJMSCs were differentiated into IPCs on these scaffolds. The differentiation efficiency was measured by analysis the expression of specific pancreatic markers by RT-qPCR and insulin release capacity via ELISA. Microscopy analysis showed the fabrication of uniform nanofibers and the formation of the islet-like clusters at the end of differentiation period. Significant differences in expression of Pdx-1 and glucagon were observed in PLLA scaffold compared to Silk scaffold (Fold: 1.625 and 1.434, respectively; P-value ≤ 0.0001 for both). Furthermore, insulin secretion at high glucose concentration was significantly higher in cells differentiated on PLLA scaffold than those cultured on Silk scaffold (P-value: 0.012). The scaffolds can enhance the differentiation of IPCs from CJMSCs. In this way, PLLA synthetic scaffold was more efficient than Silk natural scaffold. We conclude that the nanofibrous scaffolds reported herein could be used as a potential supportive matrix for islet tissue engineering.


Asunto(s)
Diferenciación Celular , Conjuntiva/metabolismo , Fibroínas/química , Células Secretoras de Insulina/metabolismo , Células Madre Mesenquimatosas/metabolismo , Nanofibras/química , Andamios del Tejido/química , Células Cultivadas , Conjuntiva/citología , Humanos , Células Secretoras de Insulina/citología , Células Madre Mesenquimatosas/citología
10.
Ecotoxicol Environ Saf ; 168: 120-126, 2019 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-30384159

RESUMEN

In this work, the efficiencies of Fenton catalytic and sonolysis processes were investigated separately and in combination together for the treatment and reduction of sludge volume. Moreover, the effects of operating parameters such as retention time, initial pH, iron concentration, and H2O2 concentration on COD reduction as well as the proportion of volatile solids to total solids (VS/TS) were studied. Finally, the effects of these processes on the sludge volume index (SVI) and sludge volume reduction (SVR) were evaluated. According to the results, the retention time of 60 min, pH = 3, hydrogen peroxide concentration of 0.13 M/L, and iron concentration of 2 mM/L were achieved as the optimum values. Furthermore, the SVR and SVI removal efficiencies in the Fenton process were 19% and 25%, respectively, but the removal efficiency in sonolysis process was very low and can be ignored. Under optimum conditions in sono-Fenton (SF) process, the SVR and SVI removal efficiencies were 55.7% and 83%, respectively. The results showed that by combining sonolysis and Fenton processes; due to the synergistic effect of ultrasonic waves, Fenton agent, and the production of more hydroxyl radicals; the COD removal efficiency increased to 77%, and the proportion of VS/TS in row activated sludge was reduced from 75% to 26%. Generally, by combining sonolysis and Fenton processes, the removal efficiency increased significantly as compared to separate processes owing to the production of more oxidizing agents and improving mass transfer.


Asunto(s)
Oxidación-Reducción , Aguas del Alcantarillado/química , Eliminación de Residuos Líquidos/métodos , Análisis Costo-Beneficio , Peróxido de Hidrógeno/metabolismo , Concentración de Iones de Hidrógeno , Hierro/metabolismo , Agua/química
11.
Anal Chem ; 90(5): 3211-3219, 2018 03 06.
Artículo en Inglés | MEDLINE | ID: mdl-29446612

RESUMEN

Understanding nanoconfinement phenomena is necessary to develop nanofluidic technology platforms. One example of nanoconfinement phenomena is shifts in reaction equilibria toward reaction products in nanoconfined systems, which have been predicted theoretically and observed experimentally in DNA hybridization. Here we demonstrate a convection-limited nanofluidic immunoassay that achieves total capture of a target analyte and an apparent shift in the antibody-antigen reaction equilibrium due to nanoconfinement. The system exhibits wavefronts of the target analyte that propagate along the length of the nanochannel at a velocity much slower than that of the carrier fluid. We apply an analytical model describing the propagation of these wavefronts to determine the density of capture antibody binding sites in the enclosed nanochannel for a known concentration of the target analyte. We then use this binding site density to estimate the concentration of solutions with 5× and 10× less analyte. Our analysis suggests that nanoconfinement results in a preference toward binding of the target analyte with the surface-grafted capture antibody, as evidenced by an apparent reduction in the equilibrium dissociation constant. Our findings motivate the advancement of new biomedical and chemical synthesis technologies by leveraging nanoconfinement effects, and demonstrate a useful platform for studying the effect of nanoconfinement on chemical systems.


Asunto(s)
Proteínas Fluorescentes Verdes/química , Inmunoensayo/métodos , Técnicas Analíticas Microfluídicas/métodos , Nanoestructuras/química , Anticuerpos/inmunología , Reacciones Antígeno-Anticuerpo , Sitios de Unión , Convección , Proteínas Fluorescentes Verdes/inmunología , Técnicas Analíticas Microfluídicas/instrumentación
12.
Electrophoresis ; 39(3): 445-455, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28944476

RESUMEN

In recent years, applications of dielectrophoresis-based platforms have been recognized as effective and dependable approach to separate cells and bioparticles, suspended in different carrier fluids, based on particle size and electrical properties. In this study, a microfluidic device was fabricated by an unprecedented electrode pattern, and several experiments were performed to enrich samples including either of yeast, Escherichia coli, or latex particles. A chemical deposition-based method was employed for fabrication of microelectrodes, inducing nonuniform electric field required for dielectrophoresis-based separation. One major advantage of our employed method is low fabrication cost, in addition to its accuracy and operation at low voltages. The performance of the microfluidic device in enriching either of injected samples was studied using spectrophotometric techniques. The effects of experimentally controllable parameters (applied-voltage amplitude and frequency, and flow rate) were studied by changing a parameter while keeping the others constant. It became evident that all the aforementioned parameters had modulating impact on the performance of the microfluidic device. Furthermore, to investigate binary interactions among the parameters, response surface methodology was exploited, resulting in a second-order polynomial model for the performance of the device as a function of the parameters. The model was employed for finding the optimum values of the parameters at which the performance of the device is the highest. At optimum values for the experimentally controllable parameters, enrichment efficiencies of 87 ± 2, 82 ± 4, and 86 ± 3% for, respectively, yeast, E. coli, and latex particles were obtained experimentally, confirming the ability of the proposed method for biological and polymeric particles enrichment.


Asunto(s)
Separación Celular/instrumentación , Electroforesis/instrumentación , Dispositivos Laboratorio en un Chip , Conductividad Eléctrica , Electrodos , Campos Electromagnéticos , Diseño de Equipo/instrumentación , Escherichia coli/citología , Escherichia coli/aislamiento & purificación , Microesferas , Tamaño de la Partícula , Saccharomyces cerevisiae/citología , Saccharomyces cerevisiae/aislamiento & purificación
13.
Lasers Med Sci ; 30(8): 2195-203, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26370204

RESUMEN

The health and suitability of mouth components play an important role towards defining facial attractiveness. An important component of the oral cavity is the color of the gingival tissue. Gingival melanin hyperpigmentation is caused by several reasons and affects people across ethnicity, race, age, and both gender. Lasers are presently being used for gingival melanin depigmentation. In this article, we reviewed studies on laser parameters, duration of gingival healing, pain perception during and after the operation, scores used for the evaluation of gingival melanin hyperpigmentation, follow-up period, treatment results, and recurrence reports. We conclude that laser ablation for gingival depigmentation is one of the most pleasant, reliable, acceptable, and impressive techniques available for treating gingival melanin hyperpigmentation.


Asunto(s)
Enfermedades de las Encías/cirugía , Hiperpigmentación/cirugía , Rayos Láser , Melaninas/metabolismo , Humanos , Resultado del Tratamiento , Cicatrización de Heridas/efectos de la radiación
14.
Front Cell Neurosci ; 18: 1385567, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38873618

RESUMEN

Introduction: Organic interfaces have recently emerged as a breakthrough trend in biomedical applications, demonstrating exceptional performance in stimulating retinal neuronal cells owing to their high flexibility and compatibility with tissues. However, the primary challenge associated with organic photovoltaics is their low efficiency compared to that of their inorganic counterparts. Among different approaches, embedding plasmonic metal nanoparticles (NPs) in active or buffer layers can efficiently improve photovoltaic cell performance. Methods: A cathode decorated with silver nanoparticles is introduced to increase the absorption Phenomenon and improve the interface performance as a computational study. In addition to embedding spherical silver nanoparticles in the active layer (A-AgNPs), a monolayer array of spherical AgNPs in the cathode electrode (K-AgNPs) is incorporated. In this configuration, the large K-AgNPs play dual roles: acting as cathode electrode and serving as plasmonic centers to increase light trapping and absorption. The bulk heterojunction PCPDTBT:PCBM is chosen as the active layer due to its favorable electronic properties. Results: Our computational analysis demonstrates a notable 10% enhancement in the photovoltaic cell current density for the developed structure with K-AgNPs in contrast to without them. Additionally, the simulation results reveal that the modeled device achieves a two-fold efficiency of the bare photovoltaic cell (without A-AgNPs and K-AgNPs), which is particularly evident at a low intensity of 0.26 mW/mm2. Discussion: This study aims to propose an efficient epiretinal prosthesis structure using a different strategy for plasmonic effects rather than conventional methods, such as incorporating NPs into the active or buffer layer. This structure can prevent the harmful side effects of using large metal NPs (r > 10 nm) in the active layer during exciton quenching, charge trapping, and recombination, which deteriorate the power conversion efficiency (PCE).

15.
Front Cell Neurosci ; 17: 1205048, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37576567

RESUMEN

Introduction: Photovoltaic restoration of vision, especially in conjunction with the use of silicon photodiodes, has gained attention for use in patients affected by blindness due to retinal layer disease. Although the use of silicon photodiodes offers miniaturization of the implant unit and increase in the stimulation channel, the implant unit may suffer from the fracture of these brittle photodiodes when mechanical pressure exerted. Methods: We present an organic solar cell (OSC)-based retinal prosthesis in which spherical gold nanoparticles (AuNPs) are embedded into the active layer to increase the efficiency of the bioelectric interface. Results: We demonstrate computationally that a modeled OSC incorporating spherical AuNPs has three times higher efficiency than that of a bare OSC presented before for retinal prostheses. Our AuNP based OSC was able to activate the neuron at the minimum light intensity of 0.26 mW/mm2, which is lower than that of the bare OSC. Discussion: The use of AuNPs in OSC allows device miniaturization or lowering of the light exposure required for neural activation using a photovoltaic retinal prosthesis, which can generally be applied in a broad range of neural prostheses.

16.
Curr Stem Cell Res Ther ; 18(5): 608-640, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-35733318

RESUMEN

In recent decades, the improvement of photoreceptor-cell transplantation has been used as an effective therapeutic approach to treat retinal degenerative diseases. In this review, the effect of different factors on the differentiation process and stem cells toward photoreceptors along with cell viability, morphology, migration, adhesion, proliferation, and differentiation efficiency is discussed. Scientists are researching to better recognize the reasons for retinal degeneration, as well as discovering novel therapeutic methods to restore lost vision. In this field, several procedures and treatments in the implantation of stem cells-derived retinal cells have been explored for clinical trials. However, the number of these clinical trials is too small to draw sound decisions about whether stem-cell therapies can offer a cure for retinal diseases. Nevertheless, future research directions have started for patients affected by retinal degeneration and promising findings have been obtained.


Asunto(s)
Degeneración Retiniana , Humanos , Degeneración Retiniana/terapia , Ingeniería de Tejidos , Epitelio Pigmentado de la Retina , Trasplante de Células Madre/métodos
17.
Artif Cells Nanomed Biotechnol ; 50(1): 40-48, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35296208

RESUMEN

Adhesion bands are pathological fibrous tissues that create in the middle of tissues and organs, often reasons of intestinal obstruction, and female infertility. Here, we explored the anti-adhesive and inflammatory capacities of PEG/silk and Ibuprofen-loaded PEG/Silk core-shell nanofibrous membranes, respectively. The ibuprofen-loaded Silk Fibroin-Poly ethylene Glycol (SF-PEG) core-shell membrane was fabricated by electrospinning and considered in terms of morphology, surface wettability, drug release, and degradation. To reveal the membrane capability for adhesion bands inhibition, the membrane was stitched among the abdominal partition and peritoneum and then evaluated using two scoring adhesion systems. According to results, the fibrous membrane hindered cell proliferation, and the scoring systems and pathology showed that in a rat model, Ibuprofen-loaded PEG/Silk core-shell membrane caused a lightening in post-operative adhesion bands and the low-grade inflammatory reaction in animal models. Collectively, we fabricated new ibuprofen-loaded PEG/SF membranes with anti-adhesion and anti-inflammation properties. Moreover, this core-shell electrospun fibrous membrane has not even now been used to prevent peritendinous adhesion generation.


Asunto(s)
Ibuprofeno , Nanofibras , Animales , Femenino , Ibuprofeno/farmacología , Membranas Artificiales , Ratas , Seda , Adherencias Tisulares/patología , Adherencias Tisulares/prevención & control
18.
Sci Total Environ ; 829: 154621, 2022 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-35306085

RESUMEN

Thermal-chemical pre-treatment has proven to facilitate the solubilization of organics and improvement in biogas generation from the organic fraction of municipal solid waste (OFMSW). However, the production of recalcitrant is inevitable when OFMSW is pretreated at high temperatures and alkali dosage. This study develops a strategy to use Fe3+ to reduce the formation of recalcitrant compounds, i.e., 5-HydroxyMethyl Furfural (5-HMF), furfurals, and humic acids (HA) during thermal-alkali pre-treatment. It was postulated that the formation of the recalcitrant compound during pre-treatment can be reduced by Fe3+ dosing to oxidize intermediates of Maillard reactions. A decrease in 5-HMF (45-49%) and furfurals (54-66%) was observed during Fe3+ (optimum dose: 10 mg/L) mediated thermal-alkali pre-treatment owing to the Lewis acid behavior of FeCl3. The Fe3+ mediated assays show a substantial improvement in VS removal (28%) and biogas yield, i.e., 31% (292 mL/gVSadded) in 150 °C + 3 g/L NaOH, 34% (316 mL/gVSadded) in 175 °C + 3 g/L NaOH, and 36% (205 mL/gVSadded) in 200 °C + 3 g/L NaOH assays, over their respective controls (no Fe3+ dosing). The reducing property of Fe3+ rendered a low ORP (-345 mV) in the system than control, which is beneficial to the anaerobic microbiome. Electrical conductivity (EC) also shows a three-fold increase in Fe3+ mediated assays over control, promoting direct interspecies electron transfer (DIET) amongst microbes involved in the electrical syntrophy. The score plot and loading plots from principal component analysis (PCA) showed that the results obtained by supplementing 10 mg/L Fe3+ at 150, 175, and 200 °C were significantly different. The correlation of the operational parameters was also mutually correlated. This work provides a techno-economically and environmentally feasible option to mitigate the formation of recalcitrant compounds and enhance biogas production in downstream AD by improving the degradability of pretreated substrate.


Asunto(s)
Biocombustibles , Eliminación de Residuos , Álcalis , Anaerobiosis , Biocombustibles/análisis , Reactores Biológicos , Hidrólisis , Metano , Eliminación de Residuos/métodos , Hidróxido de Sodio , Residuos Sólidos/análisis
19.
J Forensic Leg Med ; 85: 102296, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34896891

RESUMEN

INTRODUCTION: Dating the exact or estimated time of trauma is an important issue facing forensic medicine. Several clinical and radiological methods were used to achieve this purpose. In the recent study, we aimed to track the changes in the signal intensity of the extra-axial brain hematoma using magnetic resonance imaging (MRI) conventional sequences as well as diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC). MATERIALS AND METHODS: Considering inclusion and exclusion criteria, all patients with blunt head trauma were involved. After proper management., stabilization, and resuscitation, the participants were assessed using conventional sequences of MRI and DWI twenty-four hours, forty-eight hours, and three weeks after the injury. Temporal changes of signal intensity were compared by Wilcoxon ranged test. RESULTS: Sixteen patients sustaining blunt head trauma were included in this study. The study showed that during the time, diffusion restriction could be seen in an extraaxial hematoma. At the first 24 hours, the signal of hematoma was void in 87.5% of DWI and 100% of ADC. On the second day, they were hypo-signal in 75% of DWI and 100% 0f ADCs, and after three weeks, 100% of cases were hyper-signal in DWI and hypo-signal ADCs. CONCLUSION: This preliminary study has shown that the DWI can be used to detect and track the extra-axial hematoma. The signal intensity was void during the first twentyfour hours, although it became hypo-signal after 48 hours. Of note, the diffusion restriction is noted after three weeks.


Asunto(s)
Encéfalo , Imagen por Resonancia Magnética , Encéfalo/diagnóstico por imagen , Difusión , Imagen de Difusión por Resonancia Magnética , Hematoma/diagnóstico por imagen , Humanos
20.
Environ Technol ; 43(1): 1-9, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32431240

RESUMEN

Microbial fuel cells (MFCS) is a promising and expanding technology able to eliminate various pollutants of wastewater while converting its chemical energy into power energy using biocatalysts. The potential application of double-chamber microbial fuel cell (DC-MFC) for chemical oxygen demand (COD) removal and generated power from wastewater in the different conditions is investigated. DC-MFC is operated with anaerobic sludge as an active biocatalyst in an anode section, an aerobic cathode section and a Nafion117 membrane as a separator. The performance of the bioreactor is determined with different concentrations of chemical oxygen demand (COD) loadings in the MFC process, in terms of COD removal, power generation and columbic efficiencies. The results illustrated that COD removal efficiency increased at the high concentrations of organic matter. So that at COD concentration of 2000.0 mg/L the highest COD removal efficiency (84%) was obtained. But with increasing substrate initial concentration to 10000.0 mg/L the efficiency decreased to 79%. The important outputs of the system like the highest voltage, maximum generated power, current density, and energy efficiency with the 100,000 mg/L COD are 447 mV, 50.7 mW/m2, 570.0 mA/m2, and 18.6%, respectively. The optical density levels increased due to bacterial growth while pH severely decreased in the anode chamber when using high-concentration substrates in the MFC.


Asunto(s)
Fuentes de Energía Bioeléctrica , Purificación del Agua , Análisis de la Demanda Biológica de Oxígeno , Electricidad , Electrodos , Aguas Residuales
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