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1.
Nanomaterials (Basel) ; 12(3)2022 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-35159757

RESUMEN

Among the new adsorbent forms, nanofiber structures have attracted extra attention because of features such as high surface area, controllable properties, and fast kinetics. The objective of this study is to produce the polyacrylonitrile (PAN) electrospun nanofibers loaded with Ni-MOF-74/MWCNT to obtain maximum CO2 adsorption. The prepared PAN/MWCNT/MOF nanofiber based on the Box-Behnken design (BBD) model suggests the CO2 adsorption of about 1.68 mmol/g (at 25 °C and 7 bar) includes 14.61 w/v%, 1.43 w/w%, and 11.9 w/w% for PAN, MWCNT, and MOF, respectively. The results showed the effective CO2 adsorption of about 1.65 ± 0.03 mmol/g (BET = 65 m2/g, pore volume = 0.08 cm3/g), which proves the logical outcomes of the chosen model. The prepared PAN/MWCNT/MOF nanofiber was characterized using different analyzes such as SEM, TEM, TG, XRD, FTIR, and N2 adsorption-desorption isotherms. More MOF mass loading on the nanofiber surface via secondary growth method resulted in 2.83 mmol/g (BET = 353 m2/g, pore volume = 0.22 cm3/g, 43% MOF mass loading) and 4.35 mmol/g (BET = 493 m2/g, pore volume = 0.27 cm3/g, 65% MOF mass loading) CO2 adsorption at 7 bar for the first and second growth cycles, respectively. This indicates that secondary growth is more effective in the MOF loading amount and, consequently, adsorption capacity compared to the MOF loading during electrospinning.

2.
Environ Sci Pollut Res Int ; 28(15): 18908-18917, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33594573

RESUMEN

No effective strategy has been found so far to control the emission of microplastics. The purpose of this article is to review the available control strategies, as well as barriers to developing them. Based on the estimations in the available literature, decomposition of larger plastics, clothes washing and tire abrasion play an essential part in the total emission rate of microplastics into the ocean. Nonetheless, there is no corresponding information regarding the soil, and more information is needed to prioritize the emission sources of microplastics more preciously. Generally, there have been two approaches for the management of the microplastic issues, including the substitution of non-plastic materials for plastic ones in products such as personal care products, and microplastic removal from wastewater. The former is in its infancy and has commenced only in a few developed countries. Existing wastewater treatment plants (WWTPs) as the other approach can transfer a significant portion of the microplastics into the sludge. The result is that the final destination of these microplastics can be the soil. Since there is little information on how serious the impact of microplastics is on the soil as compared with water, the currently used WWTPs cannot be considered as a final remedy. Furthermore, there has been not been any specifically designed techniques to remove microplastics from wastewater efficiently and economically.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Monitoreo del Ambiente , Plásticos , Aguas Residuales/análisis , Contaminantes Químicos del Agua/análisis
3.
J Environ Manage ; 231: 297-302, 2019 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-30359895

RESUMEN

The aim of this study is to investigate the beneficial effect of utilizing MgO nanoparticles on the performance of ferrate(VI) oxidation process to remove blue-203 dye from wastewater. It was also made an attempt to assess the effects of pH, temperature, and MgO nanoparticle dosage on this oxidation process performance. Several sets of batch experiment were conducted to find out the effects of temperature ranging from 25 to 65 °C, pH ranging from 1.5 to 13, ferrate(VI) concentration ranging from 0.5 to 5.9 mg/L and MgO nanoparticles dosage ranging from 0.01 to 0.05 g in 150 mL solution on the removal efficiency. The results showed that adding MgO nanoparticles can improve the performance of ferrate(VI) oxidation removal method significantly, spec. at basic conditions. This synergistic effect can be attributed to the simultaneous adsorption of ferrate(VI) and dye molecules on the surface of nanoparticles. The results also revealed that the reaction between blue-203 dye and ferrate(VI) takes place rapidly at high mixing rate. It means that the required time to complete the removal process is controlled by mixing rate. It was finally concluded that adding MgO nanoparticles was an efficient means to enhance the performance of ferrate(VI) to oxidize blue-203 dye, esp. under basic conditions.


Asunto(s)
Nanopartículas , Contaminantes Químicos del Agua , Purificación del Agua , Hierro , Óxido de Magnesio , Oxidación-Reducción , Aguas Residuales
4.
J Stroke Cerebrovasc Dis ; 26(2): 286-294, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27769610

RESUMEN

BACKGROUND: Metabolic syndrome (MetS) is recently proposed as a predictor for the occurrence of vascular defects causing ischemic stroke. However, details on the association of MetS with stroke are scare in our region. The present study aimed to assess the predictive value of MetS and its components for stoke among the Iranian population. METHODS: A longitudinal population-based study was conducted on adults aged 35 years or older who were living in 3 districts in central part of Iran and followed for 10 years. Stroke was diagnosed using World Health Organization guidelines, and MetS was defined according to the Adult Treatment Panel-III definition. RESULTS: Among the 5398 subjects, 2021 suffered from MetS with an incidence of 37.4%. The incidence rates of stroke in those with and without MetS were 2.6% and 1.1%, respectively, with a higher significance in the former group (P = .026). Compared to the controls, participants with stroke exhibited a higher prevalence of some components of MetS including hyperglycemia and hypertension. On Cox proportional hazard analysis, the hazard ratio for a long-term risk of ischemic stroke was 1.37 overall (95% confidence interval: 1.15-1.63, P < .001) in subjects with MetS. Considering different components of MetS, hyperglycemia (hazard ratio = 1.83, P = .011) and hypertension (1.74, P = .019) could effectively predict occurrence of long-term ischemic stroke. CONCLUSION: MetS and its main components can be potent predictors for long-term ischemic stroke. Thus, the focus should be on identification and appropriate control of MetS components to prevent stroke occurrence.


Asunto(s)
Isquemia Encefálica/epidemiología , Síndrome Metabólico/epidemiología , Accidente Cerebrovascular/epidemiología , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Irán/epidemiología , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Prevalencia , Modelos de Riesgos Proporcionales , Riesgo , Factores de Riesgo
5.
Acta Biomed ; 87(2): 161-7, 2016 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-27648998

RESUMEN

BACKGROUND: Along with tripartiteclose relationship of socioeconomic level, smoking, and prevalence of hypertension, the present study aimed to assess the relationship between socioeconomic status (SES) and hypertension based on habitual smoking in Iranian population. METHODS: The present study analyzed the individuals subsample consisted of 9623 subjects, out of all people resident in Isfahan province in Iran of the wave of the Isfahan Heart Health Project (IHHP) in three cities in Iran: Isfahan, Najafabad and Arak. Systolic and diastolic blood pressures were measured in supine position using an automated blood pressure monitor. Smokers were defined as persons who were smoked prior to the survey and never smokers were defined as a person who had never smoked. RESULTS: Those individuals who experienced cigarette smoking, SES class was significantly lower in hypertensive patients compared with normotensive subject so 7.8% of hypertensive patients and 92.2% of normotensive ones classified in SES class IV (p<0.001). Univariate analysis showed hypertension was related to lower SES class when compared with normotension status in both smoker and nonsmoker groups (p<0.001). In stepwise logistic regression models adjusting sex, age, global dietary index and leisure time physical activity, hypertension could be predicted by lower SES in nonsmoker group, while this predictive role for SES could not be reveal in smoker group. CONCLUSION: The significant SES-smoking association may determinate in the increasing blood pressure even adjusted for other covariates such as demographics as well as dietary behaviors and leisure time physical activity.


Asunto(s)
Hipertensión/etiología , Adulto , Anciano , Ejercicio Físico , Femenino , Humanos , Hipertensión/genética , Modelos Logísticos , Masculino , Persona de Mediana Edad , Riesgo , Fumar/efectos adversos , Clase Social
6.
J Clin Lipidol ; 10(1): 143-9, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26892131

RESUMEN

BACKGROUND: High triglyceride (TG) and low high-density lipoprotein cholesterol (HDL-C) are important cardiovascular risk factors. The exact prognostic value of the TG/HDL-C ratio, a marker for cardiovascular events, is currently unknown among Iranians so this study sought to determine the optimal cutoff point for the TG/HDL-C ratio in predicting cardiovascular disease events in the Iranian population. METHOD: The Isfahan Cohort Study (ICS) is an ongoing, longitudinal, population-based study that was originally conducted on adults aged ≥ 35 years, living in urban and rural areas of three districts in central Iran. After 10 years of follow-up, 5431 participants were re-evaluated using a standard protocol similar to the one used for baseline. At both measurements, participants underwent medical interviews, physical examinations, and fasting blood measurements. "High-risk" subjects were defined by the discrimination power of indices, which were assessed using receiver operating characteristic (ROC) analysis; the optimal cutoff point value for each index was then derived. RESULTS: The mean age of the participants was 50.7 ± 11.6 years. The TG/HDL-C ratio, at a threshold of 3.68, was used to screen for cardiovascular events among the study population. Subjects were divided into two groups ("low" and "high" risk) according to the TG/HDL-C concentration ratio at baseline. A slightly higher number of high-risk individuals were identified using the European cutoff points of 63.7% in comparison with the ICS cutoff points of 49.5%. The unadjusted hazard ratio (HR) was greatest in high-risk individuals identified by the ICS cutoff points (HR = 1.54, 95% CI [1.33-1.79]) vs European cutoff points (HR = 1.38, 95% [1.17-1.63]). There were no remarkable changes after adjusting for differences in sex and age (HR = 1.58, 95% CI [1.36-1.84] vs HR = 1.44, 95% CI [1.22-1.71]) for the ICS and European cutoff points, respectively. CONCLUSION: The threshold of TG/HDL ≥ 3.68 is the optimal cutoff point for predicting cardiovascular events in Iranian individuals.


Asunto(s)
Análisis Químico de la Sangre/normas , Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/diagnóstico , HDL-Colesterol/sangre , Triglicéridos/sangre , Enfermedades Cardiovasculares/epidemiología , Estudios de Cohortes , Europa (Continente)/epidemiología , Femenino , Humanos , Irán , Masculino , Persona de Mediana Edad , Pronóstico , Curva ROC , Estándares de Referencia
7.
Curr Drug Deliv ; 13(7): 1065-1070, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26708673

RESUMEN

Liposomes can serve as promising carriers for targeting delivery and controlled release of anti-cancer drugs. Doxorubicin-loaded liposomes have achieved enhanced efficacy in some solid tumors due to EPR effect with prolonged circulation and reduced toxicity. In this study the effects of liposomal structure have been investigated on the loading efficiency and controlled release behavior. Liposomes with various compositions were prepared through a thin film hydration method, and extruded to large unilamellar vesicles (LUVs) with mean particle size (Z ave~ 100 nm) by high-pressure extrusion technique. Then, doxorubicin was loaded into liposomes using remote active loading strategy. The loading efficiency and drug release behavior were evaluated using various parameters such as medium pH, liposome compositions and cholesterol concentrations. Liposomes prepared with different compositions showed high levels of drug encapsulation. Drug loading efficiencies (>90%) achieved with high final drug/lipid ratio (0.18-0.2). Faster release was observed at pH 5.5 when compared to pH 7.4 for all formulations. The fastest release rate was observed for unsaturated lipid (<48hr) and the slowest release rate was observed for saturated lipids with high phase transition temperature such as 1, 2-distearoylphosphatidylcholine (DSPC) and hydrogenated soy phosphatidylcholine (HSPC) (10-18 days). The sustained release was observed for liposomal formulations containing cholesterol. In conclusion, we have demonstrated that drug release rate could be controlled by manipulating the composition of liposomal structures.


Asunto(s)
Doxorrubicina/análogos & derivados , Nanopartículas/química , Química Farmacéutica , Doxorrubicina/química , Sistemas de Liberación de Medicamentos , Liberación de Fármacos , Concentración de Iones de Hidrógeno , Lípidos/química , Polietilenglicoles/química
8.
Artículo en Inglés | MEDLINE | ID: mdl-26413306

RESUMEN

Pollution associated with crude oil (CO) extraction degrades the quality of waters, threatens drinking water sources and may ham air quality. The systems biology approach aims at learning the kinetics of substrate utilization and bacterial growth for a biological process for which very limited knowledge is available. This study uses the Pseudomonas aeruginosa to degrade CO and determines the kinetic parameters of substrate utilization and bacterial growth modeled from a completely mixed batch reactor. The ability of Pseudomonas aeruginosa can remove 91 % of the total petroleum hydrocarbons and 83 % of the aromatic compounds from oily environment. The value k of 9.31 g of substrate g(-1) of microorganism d(-1) could be far higher than the value k obtained for petrochemical wastewater treatment and that for municipal wastewater treatment. The production of new cells of using CO as the sole carbon and energy source can exceed 2(3) of the existing cells per day. The kinetic parameters are verified to contribute to improving the biological removal of CO from oily environment.

9.
ARYA Atheroscler ; 10(5): 238-43, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25477980

RESUMEN

BACKGROUND: The role of plasma fibrinogen, a key regulator of inflammation processes and increased carotid intima-media thickness (cIMT) to predict metabolic syndrome (MetS) is currently under investigation. We assessed differences in the indicators of cIMT and also plasma fibrinogen level between MetS and non-MetS subjects. We also assessed the role of these two parameters for independently relationship with MetS state. METHODS: The subjects in this cross-sectional survey were population-based samples of 93 men and women aged ≥ 35 years and over who were selected from the Isfahan cohort study, Isfahan, Iran. Fibrinogen was measured by the clotting assay of Clauss. Ultrasound studies of the carotid artery were performed to measure cIMT. MetS defined based on the National Cholesterol Education Program's Adult Treatment Panel III. RESULTS: The mean level of plasma fibrinogen was not different in the two groups with and without MetS (240.10 ± 27.80 vs. 242.56 ± 35.82, P = 0.714), but the mean of cIMT was considerably higher in MetS group than in non-MetS group (0.85 ± 0.06 mm vs. 0.66 ± 0.09 mm, P < 0.001). Using a multivariable logistic regression model, high cIMT could effectively predict MetS state with the presence of different components of MetS (odds ratio = 17.544, 95% confidence interval = 2.151-142.860, P = 0.008). The optimal cutoff point of cIMT for discriminating these two clinical states was 0.6 mm yielding a sensitivity of 61.5% and a specificity of 59.6%. CONCLUSION: Individuals with MetS demonstrated increased cIMT values compared with those without MetS. However, high plasma fibrinogen level may not be associated with MetS state.

10.
Cholesterol ; 2013: 198384, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23634297

RESUMEN

This study aimed to investigate whether body mass index (BMI), waist circumference (WC), or waist to hip ratio (WHR) could be a better predictor of metabolic syndrome and, if so, what would be the cutoff points for these surrogates to appropriately differentiate metabolic syndrome in different age and sex subgroups. Methods. The present cross-sectional study was conducted on a sample of Isfahan Cohort Study (ICS). In total, 468 individuals (194 with and 274 subjects without metabolic syndrome) according to the National Cholesterol Education Program's Adult Treatment Panel III (ATP-III) criteria were selected. Anthropometric indices were measured and plotted using receiver-operating characteristic (ROC) curves. Results. According to ROC curve analysis, WC and WHR parameters were better indicators of metabolic syndrome compared to BMI in women, whereas in men WHR had a lower discriminating value compared to the other two parameters. Among these three anthropometric parameters, BMI had a lower sensitivity and WC and WHR both had a higher sensitivity for predicting metabolic syndrome in women compared with in men. The cut points for WC were nearly equal in men and women, 90.3 versus 90.0, respectively. Women had higher cut points for BMI (28.5 kg/m(2)) compared to men (26.0 kg/m(2)). Our results showed the highest sensitivity and specificity for WC cut points specially in women. To predict metabolic syndrome, we looked into optimal age-specific cut points for BMI, WC, and WHR. The results indicated that WC had the highest discriminating value compared to other indicators in the different age subgroups. The optimal cut points for all three parameters gradually increased with age. Conclusion. Our results demonstrated that regardless of gender and age variables, WC could be a preferred parameter for predicting metabolic syndrome compared to BMI and WHR in Iranian population.

11.
Int J Public Health ; 57(3): 561-8, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22314544

RESUMEN

OBJECTIVES: We evaluated the association between socioeconomic status (SES) and incident cardiovascular disease (CVD) in a sample of the Iranian population. METHODS: We followed 6,504 participants who were initially free from CVD. At baseline, subjects were assessed for CVD risk factors and self-reported data were obtained for education, occupation, and income. RESULTS: After 24,379 person-years of follow-up (median = 4.8 years), 276 incident cases of CVD were detected. There was no significant association between the level of education and the incidence of CVD. In univariate analysis, retired individuals showed a significantly higher incidence of CVD than individuals who were working, and subjects in the highest tertile of income were less likely to suffer CVD than those in the lowest tertile. However, the associations disappeared after adjusting for age and sex. DISCUSSION: There was no detectable, independent association between the SES and incident CVD. The counterbalance of the higher exposure to CVD risk factors and better access to health-care services and more appropriate risk factor modification in higher socioeconomic classes might diminish the association of SES and CVD in developing countries.


Asunto(s)
Enfermedades Cardiovasculares/epidemiología , Clase Social , Anciano , Femenino , Humanos , Irán/epidemiología , Masculino , Persona de Mediana Edad , Vigilancia de la Población
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