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1.
Artif Organs ; 46(7): E211-E243, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35349178

RESUMO

BACKGROUND: Tissue engineering provides various strategies to fabricate an appropriate microenvironment to support the repair and regeneration of lost or damaged tissues. In this matter, several technologies have been implemented to construct close-to-native three-dimensional structures at numerous physiological scales, which are essential to confer the functional characteristics of living tissues. METHODS: In this article, we review a variety of microfabrication technologies that are currently utilized for several tissue engineering applications, such as soft lithography, microneedles, templated and self-assembly of microstructures, microfluidics, fiber spinning, and bioprinting. RESULTS: These technologies have considerably helped us to precisely manipulate cells or cellular constructs for the fabrication of biomimetic tissues and organs. Although currently available tissues still lack some crucial functionalities, including vascular networks, innervation, and lymphatic system, microfabrication strategies are being proposed to overcome these issues. Moreover, the microfabrication techniques that have progressed to the preclinical stage are also discussed. CONCLUSIONS: This article aims to highlight the advantages and drawbacks of each technique and areas of further research for a more comprehensive and evolving understanding of microfabrication techniques in terms of tissue engineering and regenerative medicine applications.


Assuntos
Bioimpressão , Engenharia Tecidual , Microtecnologia , Impressão Tridimensional , Medicina Regenerativa/métodos , Engenharia Tecidual/métodos , Alicerces Teciduais/química
2.
Int J Pharm ; 603: 120698, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33989750

RESUMO

Treatment of skin injuries is still facing major challenges, such as chronicity and infections, particularly those caused by multi-drug resistance pathogens. An effective treatment of such wounds should accelerate the wound healing process while preventing bacterial contamination. Here, a novel core-shell nanofiber mat was fabricated comprising gelatin/polyvinyl alcohol (as a core) and aloe vera/arabinose/polyvinylpyrrolidone (as a shell) for accelerating the healing process of bacteria-infected wounds. Trachyspermum Ammi (Ajwain) essential oil (EO), as a potent and natural antimicrobial agent against microorganisms, was incorporated into the core of nanofiber mats using coaxial electrospinning. The microscopy images demonstrated the successful fabrication of the core-shell structure with a uniform fiber size of 564 ± 106.35 nm. Moreover, Ajwain EO-loaded nanofiber mat (core-shell/EO) provided excellent antimicrobial activity and antioxidant ability. The in vitro and ex vivo release of Ajwain EO from the fabricated nanofiber mat corroborated a prolonged release profile. Furthermore, in vivo antibacterial activity, wound closure, and histomorphological examinations showed the high efficacy of the core-shell/EO mat in the treatment of Staphylococcus aureus-infected full-thickness rat wounds compared to standard control treatment with a gauze. Overall, these results represent the core-shell/EO mat's potential as a newly developed wound dressing for bacteria-infected full-thickness skin injuries.


Assuntos
Anti-Infecciosos , Nanofibras , Óleos Voláteis , Animais , Antibacterianos , Ratos , Cicatrização
3.
J Clin Lab Anal ; 35(7): e23850, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34028857

RESUMO

BACKGROUND: Superficial and cutaneous fungal infections are common in tropical areas. The aim of this study was to provide a basic database of superficial and cutaneous mycoses and the most common etiological agents among patients. METHODS: Between 2015 and 2019, a total of 1807 patients suspected of superficial and cutaneous mycosis referring to the mycology laboratory of Shiraz medical school, Fars, Iran were evaluated. Specimens were taken from the patients' affected area, and clinical samples were examined by direct microscopy and culture. The epidemiological profile of the patients was collected. RESULTS: A total of 750 patients were confirmed with mycoses. Positive samples totaled 750 cases consisting of the nail (373/49.7%), skin (323/43%), head (47/6.26%), and mucosal membrane (4/0.5%). The yeasts group included 304 Candida spp. (70.3%), 123 Malassezia spp. (28.47%), and 5 Rhodotorula spp. (1.1%). The filamentous fungi were distributed as 34.8% dermatophytes and 7.5% non-dermatophyte. The clinical types of dermatophytosis were tinea unguium (110/261), tinea capitis (50/261), tinea pedis (48/261), tinea corporis (37/261), and tinea cruris (16/261). Non-dermatophyte molds included A. flavus 17, A. niger 4, Aspergillus spp. 15, Penicillium. 10, Fusarium 6, Mucor 2, Stemphylium 1, and Alternaria 1. CONCLUSION: This study provides useful data for the study trends of superficial and cutaneous fungal infections in a specific area. The mycological data confirmed higher incidence of candidiasis (mainly onychomycosis) and dermatophytosis in patients affected by fungal pathogens, which helped to better understand the epidemiological aspects of these mycoses.


Assuntos
Micoses/epidemiologia , Dermatopatias/epidemiologia , Dermatopatias/microbiologia , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Fungos/isolamento & purificação , Humanos , Lactente , Irã (Geográfico)/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Adulto Jovem
4.
Int J Biol Macromol ; 182: 1310-1321, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34000308

RESUMO

Cutaneous leishmaniasis (CL) is a significant public health problem caused by different species of Leishmania parasites. Due to low skin permeability, the development of an effective system for delivery of Amphotericin B (AMB), the common effective drug for leishmaniasis treatment, is required to replace the unpleasant and problematic injections. To overcome this problem, a dissolvable microneedle (MN) patch was developed, using biodegradable polymers (a mixture of polyvinylpyrrolidone and carboxymethyl cellulose) for AMB's transdermal delivery. Scanning electron microscopy and fluorescent images showed successful fabrication of the MNs and homogeneous dispersion of the drug into the needles. MNs showed good mechanical properties with the ability to penetrate the rat skin and reach the lower layers. After insertion to the skin, the MNs were rapidly dissolved to release the encapsulated drug, and the resulted micropores in the skin were quickly resealed within 30 min. MN patches showed non-toxicity as exposed to HT-29 cell line. Flow cytometry results showed a potent in vitro leishmanicidal activity of AMB-loaded MN patches against the Leishmania parasites (up to 86% of the parasites' death). Taken together, MN patches might represent a new, efficient and clinically translational approach for transdermal AMB delivery to treat CL.


Assuntos
Anfotericina B/administração & dosagem , Anfotericina B/uso terapêutico , Carboximetilcelulose Sódica/química , Leishmaniose Cutânea/tratamento farmacológico , Agulhas , Povidona/química , Administração Cutânea , Anfotericina B/farmacologia , Animais , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células HT29 , Humanos , Masculino , Imagem Óptica , Ratos Sprague-Dawley , Pele/efeitos dos fármacos , Espectroscopia de Infravermelho com Transformada de Fourier , Adesivo Transdérmico
5.
Int J Pharm ; 597: 120288, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33508343

RESUMO

Wounds are prone to bacterial infections, which cause a delayed healing process. Regarding the emergence of bacterial resistance to common antibiotics, using natural antimicrobial agents can be beneficial. Chitosan is a biological polymer, which has shown partial antioxidant and antimicrobial activities. In this study, core-shell nanofibrous scaffolds composed of chitosan (CS)/polyvinyl alcohol (PVA) as the core and polyvinylpyrrolidone (PVP)/ maltodextrin (MD) as the shell were developed. Satureja mutica (S. mutica) or Oliveria decumbens (O. decumbens) essential oil (EO) was encapsulated into the core of the produced scaffolds. The broth microdilution analysis showed significant antimicrobial activity of the EOs. The SEM analysis indicated that the unloaded and loaded core-shell scaffolds with S. mutica or O. decumbens EO had a uniform, beadless structure with fiber mean diameters of 210 ± 50, 250 ± 45, and 225 ± 46 nm, respectively. The CS/PVA-PVP/MD and CS/PVA/EO-PVP/MD scaffolds indicated suitable mechanical properties. The addition of the studied EOs enhanced the antioxidant activity of the scaffolds. The antimicrobial test of produced scaffolds showed that loading of 10% S. mutica or O. decumbens EO could broaden the microbicidal activity of the CS/PVA-PVP/MD scaffolds. These results revealed that the CS/PVA/EO-PVP/MD nanofibrous scaffolds are promising candidates for wound dressing.


Assuntos
Anti-Infecciosos , Quitosana , Nanofibras , Óleos Voláteis , Satureja , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Bandagens , Óleos Voláteis/farmacologia , Álcool de Polivinil
6.
Environ Monit Assess ; 192(3): 176, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32062749

RESUMO

Interactive effects of mixtures of pesticides on bacteria are rarely investigated. The aim of this study was to investigate the cumulative, synergistic, and antagonistic effects of four widely used agricultural pesticides including deltamethrin, diazinon, chlorpyrifos, and 2,4-dichlorophenoxyacetic acid (2,4-D) on Pseudomonas, Aeromonas, and Bacillus bacteria. The reduction of alamar blue, as an indicator of bacterial activity, was measured using a spectrophotometer at 600-nm wavelength. Data were analyzed using SPSS 24.0 software. The binary mixtures of pesticides had mainly antagonistic and additive effects, but quadruple mixtures of pesticides had synergistic effects on all of the three bacterial species. In the mixtures of pesticides, increasing the number of compounds leads to more synergistic effects.


Assuntos
Bactérias , Clorpirifos , Monitoramento Ambiental , Praguicidas , Agricultura , Bactérias/efeitos dos fármacos , Praguicidas/toxicidade
7.
Water Environ Res ; 92(7): 969-974, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31904156

RESUMO

In this study, CoFe2 O4 nanoparticles supported on multi-walled carbon nanotubes (MWCNTs), as novel peroxymonosulfate (PMS) activator, were synthesized for degradation of Reactive Black 5 (RB5). The results showed that the maximum removal efficiencies of RB5 (100%), chemical oxygen demand (83.12%), and total organic carbon (65.5%) could happen at pH of 7, catalyst dosage of 100 mg/L, PMS dosage of 2 mM, RB5 concentration of 50 mg/L, and time of 30 min. The results of the temperature effect showed that the activation energy (Ea  = 20.92 kJ/mol) for the synthesized catalyst is much lower compared to other studies. The PMS/MWCNTs-CoFe2 O4 system had higher decolorization efficiency and kinetic rates compared to other adsorption and oxidation systems. Quenching experiments proved that RB5 was degraded by sulfate and hydroxyl radicals. The MWCNTs-CoFe2 O4 catalyst showed suitable stability and reusability even after five consecutive catalytic reactions. The continuous treatment of RB5 in real water resources was performed using catalyst packed in a column reactor, and its results showed the high efficiency of the column in the catalytic treatment of the dye at long reaction time. Based on the proposed degradation pathway, the azo bands and the naphthalene structure of RB5 are oxidized to compounds with low molecular weight. PRACTITIONER POINTS: MWCNTs-CoFe2 O4 was used as a novel recyclable catalyst for the activation of peroxymonosulfate and dye degradation. The rate of dye degradation and peroxymonosulfate activation by MWCNTs-CoFe2 O4 was much higher than that of the catalysts alone. Radical SO 4 · - , with contribution percentage of 73.20%, was the main agent for degradation of Reactive Black 5 dye. MWCNTs-CoFe2 O4 in the dye degradation process showed excellent stability and reusability, lower activation energy, and easier separation. The dye degradation products were identified by gas chromatography and UV-vis spectrophotometric analyses, and their degradation pathway was suggested.


Assuntos
Nanopartículas , Nanotubos de Carbono , Naftalenossulfonatos , Peróxidos
8.
Environ Monit Assess ; 191(3): 124, 2019 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-30710209

RESUMO

Since trace metals rarely appear singly in industrial effluents, it is a major challenge to address combined effects of such toxicants on biological units of wastewater treatment plants. The aim of this study was interaction assessment of Cd, Cr, Pb, Ni, and Hg in their effects on activated sludge bacteria using analytical methods. Two mathematical models were used to determine the effect of binary mixtures of Hg, Cd, Cr, Pb, and Ni on activated sludge bacteria using a dehydrogenase enzyme assay. Calculated EC50 values were compared to experimentally observed values of mixtures. Interactive effects were counted to be antagonistic for Hg and Cd, Cd and Pb, Cd and Ni, and Cr and Pb, synergistic for Cd and Cr and Hg and Cr, and additive for other binary mixtures. Maximum toxicity was related to Hg and Cr, Cd and Cr, and Hg and Cd. Physicochemical monitoring of single metals may underestimate hazards arising from these pollutants in environmental samples. Therefore, any possible interaction between metals in such environments should be considered when establishing environmental safety standards.


Assuntos
Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Metais Pesados/análise , Oligoelementos/análise , Bactérias/metabolismo , Cádmio/análise , Chumbo/análise , Mercúrio/análise , Esgotos
9.
RSC Adv ; 9(29): 16496-16508, 2019 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-35516408

RESUMO

CoFe3O4 nanoparticles supported on multi-walled carbon nanotubes (MWCNTs-CoFe3O4) were synthesized by the co-precipitation method as a novel catalyst for degradation of diclofenac (DCF). The comparative experiments indicated that MWCNTs-CoFe3O4 has a better catalytic activity in degradation of DCF and activation of peroxymonosulfate (PMS) compared to other catalytic systems. This can be attributed to the interaction of MWCNTs with CoFe3O4 in accelerating the absorption process and activating the PMS (E a = 22.93 kJ mol-1). The removal efficiencies of DCF and total organic carbon (TOC) were 99.04% and 50.11%, under optimum conditions, e.g., pH of 7, PMS dosage of 4 mM, DCF concentration of 30 mg L-1, catalyst dosage of 500 mg L-1, and reaction time of 120 min. The oxidation of DCF was fitted by the pseudo-first-order kinetic model and the constant rate was increased by increasing the pH, temperature, dosage of PMS and catalyst. The production of reactive species was studied using scavengers such as TBA and ethanol and the results showed that sulfate radical is the reactive species responsible for the degradation of DCF. The MWCNTs-CoFe3O4 catalyst showed high stability and reusability based on five successful repeated reactions, X-ray diffraction and energy dispersive X-ray spectroscopy analysis. Based on the intermediates detected by gas chromatography-mass spectrometry (GC-MS), the possible pathways for DCF catalytic oxidation were proposed. The results explained that the PMS/MWCNTs-CoFe3O4 system is a promising method for treating DCF solution due to high efficiency, good reusability of catalyst and greater PMS activation.

10.
Environ Sci Pollut Res Int ; 25(31): 30979-30997, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30182314

RESUMO

Development and land use change lead to accelerated soil erosion as a serious environmental problem in river catchments in Iran. Reliable information about the sources of sediment in catchments is therefore necessary to design effective control strategies. This study used a composite sediment source tracing procedure to determine the importance of forest road cuttings as a sediment source in a mountainous catchment located in northern Iran. A fallout radionuclide (137Cs) and 12 geochemical tracers (Ca, Cu, Fe, K, Mg, Mn, Na, Ni, OC, Pb, Sr and TN) were used to determine the relative contributions of three sediment source types (hillslopes, road cuttings and channel banks) to both suspended and bed sediment samples. Two mixing models based on different mathematical concepts were used to apportion the sediment sources: the mixture sampling importance resampling Bayesian model which incorporates the mass-balance matrix and a distribution model using normal and summed probability of normal distributions. The results of both mixing models indicated that sub-soil erosion from road cuttings and channel banks dominated the sources of river bed and suspended sediment samples, respectively. These results therefore highlight that conservation that works in the study area to remedy the sediment problem should initially focus on stabilisation and rehabilitation of road cuttings and channel banks. This successful application of a composite (radionuclide and geochemical) tracing technique for discriminating source end members characterised by different erosion processes underscores the importance of sub-soil erosion in this case study.


Assuntos
Conservação dos Recursos Naturais , Sedimentos Geológicos/análise , Poluentes do Solo/análise , Teorema de Bayes , Carbono/análise , Radioisótopos de Césio/análise , Monitoramento Ambiental , Florestas , Irã (Geográfico) , Metais/análise , Nitrogênio/análise , Rios , Solo/química
11.
Adv Biomed Res ; 7: 80, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29930920

RESUMO

BACKGROUND: Due to depletion of fossil fuel reserves, global warming, and the need for energy efficiency, the new energy resource is required. For this purpose, hydrogen can be considered as clean and efficient energy carrier. In this study, biohydrogen production from physical pretreated mixed culture was investigated. MATERIALS AND METHODS: In this study, the optimal conditions for physical pretreatment of mixed culture were investigated for the enrichment of hydrogen-producing bacteria (HPB). Three individual pretreatment processes, including thermal, ultraviolet (UV) radiation, and ultrasonication (US) were conducted in batch tests. The batch tests were carried out via 500 mL glass flasks with working volume 400 mL. Glucose was used as sole substrate, and other essential nutrient and trace elements were added. To agitation of substrate with HPB inoculum, the magnet stirrer was used at 60 rpm. RESULTS: The results showed the production of H2 gas could be increased by appropriate pretreatment methods including thermal pretreatment at 100°C. At 100°C as a pretreatment, the volume of H2 gas was 112.25 mL and followed by US (97.46 mL), UV (89.11 mL), 80°C (72.72 mL), 90°C (53.95 mL), and 70°C (26.01 mL). In the pretreatment methods, the solution pH and effluent soluble chemical oxygen demand was 6.3-6.7 and 5100-8300 mg/L, respectively. CONCLUSIONS: The Gompertz model depicts that all R2 values were more than 0.93, indicating that the fitted curves were best fitted with the experimental points.

12.
Germs ; 6(2): 60-5, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27482515

RESUMO

INTRODUCTION: Tuberculosis is still a considerable health problem in many countries. Rapid diagnosis of this disease is important, and adenosine deaminase (ADA) has been used as a diagnostic test. The aim of this study was to assess the diagnostic value of ADA in the sputum of patients with pulmonary tuberculosis. METHODS: The current study included 40 patients with pulmonary tuberculosis (culture positive, smear ±) and 42 patients with non tuberculosis pulmonary diseases (culture negative). ADA was measured on all of the samples. RESULTS: The median value of ADA in non-tuberculosis patients was 2.94 (4.2) U/L and 4.01 (6.54) U/L in tuberculosis patients, but this difference was not statistically significant (p=0.100). The cut-off point of 3.1 U/L had a sensitivity of 61% and a specificity of 53%, the cut-off point of 2.81 U/L had a sensitivity of 64% and a specificity of 50% and the cut-off point of 2.78 U/L had a sensitivity of 65% and a specificity of 48%. The positive predictive values for cut-off points of 3.1, 2.81 and 2.78 U/L were 55.7%, 57.44% and 69.23%, respectively. The negative predictive values for the abovementioned cut-off points were 56.75%, 57.14% and 55.88%, respectively. CONCLUSION: Our results showed that sputum ADA test is neither specific nor sensitive. Because of its low sensitivity and specificity, determination of sputum ADA for the diagnosis of pulmonary tuberculosis is not recommended.

13.
Appl Radiat Isot ; 114: 87-91, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27213808

RESUMO

Simulation, design and fabrication of a sealing enclosure is carried out for a NaI(Tl) 2″×2″ detector, to be used as in situ gamma radioactivity measurement system in marine environment. Effect of sealing enclosure on performance of the system in laboratory and marine environment (distinct tank with 10m(3) volume) were studied using point sources. The marine volumetric efficiency for radiation with 1461keV energy (from (40)K) is measured with KCl volumetric liquid source diluted in distinct tank. The experimental and simulated efficiency values agreed well. Marine volumetric efficiency calibration curve is calculated for 60keV to 1461keV energy with Monte Carlo method. This curve indicates that efficiency increasing rapidly up to 140.5keV but then drops exponentially.


Assuntos
Radioisótopos/análise , Espectrometria gama/instrumentação , Poluentes Radioativos da Água/análise , Calibragem , Simulação por Computador , Desenho de Equipamento , Humanos , Método de Monte Carlo , Monitoramento de Radiação/instrumentação , Monitoramento de Radiação/estatística & dados numéricos , Água do Mar/análise , Espectrometria gama/estatística & dados numéricos
14.
Environ Sci Pollut Res Int ; 23(4): 3285-99, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26490904

RESUMO

Measurements of natural radioactivity levels and heavy metals in sediment and soil samples of the Anzali international wetland were carried out by two HPGe-gamma ray spectrometry and atomic absorption spectroscopy techniques. The concentrations of (235)U, (226)Ra, (232)Th, (40)K, and (137)Cs in sediment samples ranged between 1.05 ± 0.51-5.81 ± 0.61, 18.06 ± 0.63-33.36 ± .0.34, 17.57 ± 0.38-45.84 ± 6.23, 371.88 ± 6.36-652.28 ± 11.60, and 0.43 ± 0.06-63.35 ± 0.94 Bq/kg, while in the soil samples they vary between 2.36-5.97, 22.71-38.37, 29.27-42.89, 472.66-533, and 1.05-9.60 Bq/kg for (235)U, (226)Ra, (232)Th, (40)K, and (137)Cs, respectively. Present results are compared with the available literature data and also with the world average values. The radium equivalent activity was well below the defined limit of 370 Bq/kg. The external hazard indices were found to be less than 1, indicating a low dose. Heavy metal concentrations were found to decrease in order as Fe > Mn > Sr > Zn > Cu > Cr > Ni > Pb > Co > Cd. These measurements will serve as background reference levels for the Anzali wetland.


Assuntos
Radioisótopos de Césio/análise , Metais Pesados/análise , Radioisótopos de Potássio/análise , Rádio (Elemento)/análise , Poluentes Radioativos do Solo/análise , Tório/análise , Urânio/análise , Espectrometria gama/métodos , Espectrofotometria Atômica/métodos , Áreas Alagadas
15.
Environ Monit Assess ; 187(5): 263, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25893755

RESUMO

One of the most important factors that affect the operation efficiency of sequencing batch reactor (SBR) technology is bacterial viability and biomass activity. The acute toxicity of three heavy metals to four dominant strains of sequencing batch reactor (Pseudomonas, Aeromonas, Enterobacter, and Bacillus) was investigated using a resazurin bioassay. After exposing the bacterial strains to soluble compound of Hg, Cd, and Pb, at more than five selected concentrations, the median effective concentration (EC50) and the mortality rate values were calculated. Large differences were observed in sensitivities of the four bacterial strains to the metals. Pseudomonas showed the highest sensitivity for Cd (EC50 = 0.06 µmol/L) and Hg (EC50 = 11.75 µmol/L), while Aeromonas showed the highest sensitivity for Pb (EC50 = 48.27 µmol/L). Considering the EC50 test results, it was concluded that Pseudomonas and Aeromonas are excellent and reliable bioindicators for assessing the toxicity of water and wastewaters polluted by Cd, Hg, and Pb. The rapidity (30 min) and simplicity of the resazurin bioassay procedure enable this enzymatic test to be used in toxicity assessment of small and decentralized wastewater treatment plants (WWTPs).


Assuntos
Reatores Biológicos/microbiologia , Metais Pesados/toxicidade , Poluentes Químicos da Água/toxicidade , Biomassa , Cádmio/toxicidade , Monitoramento Ambiental , Chumbo/toxicidade , Mercúrio/toxicidade , Eliminação de Resíduos Líquidos , Águas Residuárias/química , Águas Residuárias/microbiologia
16.
J Environ Radioact ; 144: 134-9, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25847859

RESUMO

Portable high-resolution gamma-ray spectrometry was carried out to determine the natural radioactivity levels in high volume surface water samples of the northern coast of Oman Sea, covering the coastal strip from Hormoz strait to Goatr seaport, for the first time. The water samples from 36 coastal and near shore locations were collected for analysis. Analyses on the samples collected were carried out to determine (226)Ra, (232)Th and (40)K contents. The concentration of (226)Ra, (232)Th and (40)K in surface water samples ranged between 2.19 and 2.82 Bq/L, 1.66-2.17 Bq/L and 132.6-148.87 Bq/L, respectively. The activity profile of radionuclides shows low activity across the study area. The study also examined some radiation hazard indices. The external hazard index was found to be less than 1, indicating a low dose. The results of measurements will serve as background reference level for Oman Sea coastlines.


Assuntos
Radiação de Fundo , Monitoramento de Radiação , Poluentes Radioativos da Água/análise , Irã (Geográfico) , Oceanos e Mares , Espectrometria gama
17.
Mar Pollut Bull ; 92(1-2): 201-211, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25561003

RESUMO

This study aims to establish a managed sampling plan for rapid estimate of natural radio-nuclides diffusion in the northern coast of the Oman Sea. First, the natural radioactivity analysis in 36 high volume surface water samples was carried out using a portable high-resolution gamma-ray spectrometry. Second, the oceanic currents in the northern coast were investigated. Then, the third generation spectral SWAN model was utilized to simulate wave parameters. Direction of natural radioactivity propagation was coupled with the preferable wave vectors and oceanic currents direction that face to any marine pollution, these last two factors will contribute to increase or decrease of pollution in each grid. The results were indicated that the natural radioactivity concentration between the grids 8600 and 8604 is gathered in the grid 8600 and between the grids 8605 and 8608 is propagated toward middle part of Oman Sea.


Assuntos
Monitoramento Ambiental/métodos , Radioisótopos/análise , Modelos Teóricos , Oceanos e Mares , Omã , Água do Mar/análise , Água do Mar/química , Espectrometria gama/métodos
18.
J Digit Imaging ; 27(1): 77-89, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24092327

RESUMO

The demand for automatically classification of medical X-ray images is rising faster than ever. In this paper, an approach is presented to gain high accuracy rate for those classes of medical database with high ratio of intraclass variability and interclass similarities. The classification framework was constructed via annotation using the following three techniques: annotation by binary classification, annotation by probabilistic latent semantic analysis, and annotation using top similar images. Next, final annotation was constructed by applying ranking similarity on annotated keywords made by each technique. The final annotation keywords were then divided into three levels according to the body region, specific bone structure in body region as well as imaging direction. Different weights were given to each level of the keywords; they are then used to calculate the weightage for each category of medical images based on their ground truth annotation. The weightage computed from the generated annotation of query image was compared with the weightage of each category of medical images, and then the query image would be assigned to the category with closest weightage to the query image. The average accuracy rate reported is 87.5 %.


Assuntos
Sistemas de Gerenciamento de Base de Dados/estatística & dados numéricos , Bases de Dados Factuais/estatística & dados numéricos , Armazenamento e Recuperação da Informação/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Sistemas de Informação em Radiologia/estatística & dados numéricos , Humanos , Reprodutibilidade dos Testes , Semântica
19.
Mar Pollut Bull ; 74(1): 425-34, 2013 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-23850123

RESUMO

Radionuclides which present in different beach sands are sources of external exposure that contribute to the total radiation exposure of human. (226)Ra, (235)U, (232)Th, (40)K and (137)Cs analysis has been carried out in sand samples collected at six depth levels, from eight locations of the northern coast of Iran, Ramsar, using high-resolution gamma-ray spectroscopy. The average Specific activities of natural radionuclides viz., (226)Ra, (235)U, (232)Th, (40)K and (137)Cs, in the 0-36 cm depth sand were found as: 19.2±0.04, 2.67±0.17, 17.9±0.06, 337.5±0.61 and 3.35±0.12 Bq kg(-1), respectively. The effects of organic matter content and pH value of sand samples on the natural radionuclide levels were also investigated. Finally, the measured radionuclide concentrations in the Ramsar beach were compared with the world average values, as reported by UNSCEAR (2000). None of the studied beaches were considered as a radiological risk.


Assuntos
Raios gama , Monitoramento de Radiação/instrumentação , Dióxido de Silício/química , Poluentes Radioativos da Água/análise , Praias , Irã (Geográfico) , Monitoramento de Radiação/métodos , Radioisótopos/análise
20.
J Environ Public Health ; 2013: 169682, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23840229

RESUMO

Due to complex composition of leachate, the comprehensive leachate treatment methods have been not demonstrated. Moreover, the improper management of leachate can lead to many environmental problems. The aim of this study was application of Fenton process for decreasing the major pollutants of landfill leachate on Kermanshah city. The leachate was collected from Kermanshah landfill site and treated by Fenton process. The effect of various parameters including solution pH, Fe(2+) and H2O2 dosage, Fe(2+)/H2O2 molar ratio, and reaction time was investigated. The result showed that with increasing Fe(2+) and H2O2 dosage, Fe(2+)/H2O2 molar ratio, and reaction time, the COD, TOC, TSS, and color removal increased. The maximum COD, TOC, TSS, and color removal were obtained at low pH (pH: 3). The kinetic data were analyzed in term of zero-order, first-order, and second-order expressions. First-order kinetic model described the removal of COD, TOC, TSS, and color from leachate better than two other kinetic models. In spite of extremely difficulty of leachate treatment, the previous results seem rather encouraging on the application of Fenton's oxidation.


Assuntos
Peróxido de Hidrogênio/química , Ferro/química , Eliminação de Resíduos , Resíduos Sólidos , Poluentes Químicos da Água/química , Irã (Geográfico) , Cinética , Modelos Teóricos , Oxirredução
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