Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Environ Monit Assess ; 191(7): 474, 2019 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-31256268

RESUMO

In this study, polybrominated diphenyl ethers (PBDEs) levels in soil were studied for a whole year in highly industrialized region of Turkey (Dilovasi) at 23 sampling sites. Σ8PBDE concentrations were between 0.15 and 286 µg kg-1 and the overall average concentration was 14.45 ± 25.07 µg kg-1 (average ± SD). BDE-209 was the most abundant compound. PBDEs concentrations decreased spatially as follows: industrial/urban > urban > suburban > rural. However, there was not any significant seasonal trend except for some industrial/urban sites. In the region, calm weather conditions prevailed during the sampling periods, enhancing the impact of the industrial emissions on nearby soil concentrations by atmospheric deposition without being diluted by winds. All congeners had significant but weak correlations with soil organic matter content indicating the impact of nearby sources rather than soil properties on soil PBDEs concentrations at the sampling sites. Positive matrix factorization method was also used for the apportionment of the PBDEs sources in Dilovasi soil. Industrial activities (i.e., iron-steel production, metallurgical processes, and recycling of plastics), traffic, and residential areas were found to be the primary sources of the measured PBDEs in the soil.


Assuntos
Éteres Difenil Halogenados/análise , Poluentes do Solo/análise , Emissões de Veículos/análise , Monitoramento Ambiental/métodos , Desenvolvimento Industrial , Indústrias , Solo/química , Turquia
2.
Environ Technol ; 44(25): 3803-3812, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35499395

RESUMO

Compared to extensive studies on affecting parameters in sulfur removal with ZnO adsorbents from coal gasification syngas, similar studies conducted for biomass gasification syngas (BGS) are quite rare. Thus, considering the BGSs with high water content, this study was performed to investigate the effect of H2O presence in syngas on sulfur removal capacity (SRC) of ZnO adsorbents. Initially, the effect of gas composition and temperature on SRC in binary gas mixture was investigated. While H2O decreased the SRC, as expected, the highest reduction in the capacity occurred in the CO-H2S gas mixture due to observed COS formation. Second, the SRCs and resulting COS formation were compared for synthetic syngas mixtures having different water contents and for different amounts of adsorbents. Finally, the separate and combined effects of temperature and H2O on SRC and COS formation in synthetic syngas were investigated by comparing SRCs of typical syngas under wet and dry conditions. The results showed that increasing the amount of adsorbent and temperature results in higher SRC due to a reduction in COS formation through the reactions of COS with H2 and H2O. This indicates that it is critical to control the residence time of syngas and temperature to reduce COS formation during ZnO adsorption.


Assuntos
Óxido de Zinco , Gases , Enxofre , Temperatura , Carvão Mineral , Biomassa
3.
Sci Total Environ ; 880: 163224, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37019236

RESUMO

In this study, ambient air, surface water and sediment samples were simultaneously collected and analyzed for PCBs to investigate their levels, spatial variations and exchanges between these three compartments at different sampling sites for 12 months in Bursa, Türkiye. During the sampling period, a total of 41 PCB concentrations were determined in the ambient air, surface water (dissolved and particle phase) and sediment. Thus, 945.9 ± 491.6 pg/m3 (average ± STD), 53.8 ± 54.7 ng/L, 92.8 ± 59.3 ng/L and 71.4 ± 38.7 ng/g, respectively. The highest concentrations of PCBs in the ambient air and in water particulate phase were measured at the industrial/agricultural sampling site (1308.6 ± 252.1 pg/m3 and 168.7 ± 21.2 ng/L, respectively), ∼ 4-10 times higher than background sites; while the highest concentrations in the sediment and dissolved phase were measured at the urban/agricultural sampling sites (163.8 ± 27.0 ng/L and 145.7 ± 15.3 ng/g, respectively), ∼ 5-20 times higher than background sites. PCB transitions between ambient air-surface water (fA/fW) and surface water-sediment (fW/fS) were investigated by fugacity ratio calculations. According to the fugacity ratios obtained, volatilization from the surface water to the ambient air was observed at all sampling sites (98.7 % of fA/fW ratios are <1.0). Additionally, it has been determined that there is a transport from the surface water to the sediment (100.0 % of fW/fS ratios are higher than 1.0). The flux values in ambient air-surface water and surface water-sediment environments ranged from -1.2 to 1770.6 pg/m2-day and from -225.9 to 0.001 pg/m2-day, respectively. The highest flux values were measured for PCBs with low chlorine content (Mono-, Di-Cl PCBs), while the lowest flux values were measured for the high chlorine content PCBs (Octa-, Nona- and Deca-Cl PCBs). As it was determined in this study that surface waters contaminated by PCBs have the potential to pollute both air and sediments, it will be important to take measures to protect surface waters.

4.
Sci Total Environ ; 881: 163508, 2023 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-37059133

RESUMO

The presence of microplastics (MPs) in the atmosphere and their relationship with other pollutants have been gaining attention due to both their ubiquity and threatening human health. As well phthalic acid esters (PAEs) regarding as plasticizers for being added in plastic materials are key role for plastic pollution. In this study, the concentrations and sources of airborne MPs together with major PAEs and their relationships were investigated for four seasons. MP particles <20 µm, constituting the majority of the samples, were successfully revealed by NR fluorescent analysis. As a result of the µATR-FTIR analyzes, it was seen that besides different polymer derivatives, dye-pigment types, some minerals and compounds, and abundant semi-synthetic fibers and natural fibers were also present. MPs concentration were found in the range of 7207-21,042 MP/m3 in summer, 7245-32,950 MP/m3 in autumn, 4035-58,270 MP/m3 in winter and 7275-37,094 MP/m3 in spring. For the same period, the concentrations of PAEs ranged from 9.24 to 115.21 ng/m3 with an average value of 38.08 ± 7.92 ng/m3. PMF was also applied and four factors were extracted. Factor 1, accounts 52.26 % and 23.27 % of the total PAEs and MPs variances, was attributed to PVC sources. Factor 2, explaining 64.98 % of the total MPs variance had the highest loading of MPs and moderate loadings of relatively low molecular weight of PAEs, was attributed to plastics and personal care products. Factor 3, explaining the 28.31 % of the total PAEs variance was laden with BBP, DnBP, DiBP and DEP and was attributed to various plastic input during the sampling campaign coming from the industrial activities. The last factor accounts for 11.65 % of the total PAEs variance and was dominated by DMEP and it was linked to a source of the activities performed in the laboratories of the university.

5.
Curr HIV Res ; 21(2): 109-116, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37231747

RESUMO

OBJECTIVES: This study aimed to analyze the antiretroviral drug resistance in antiretroviral treatment-naïve HIV-positive patients in the Aegean Region of Turkey from 2012 to 2019. METHODS: The study included 814 plasma samples from treatment-naïve HIV-positive patients. Drug resistance analysis was performed by Sanger sequencing (SS) between 2012-2017 and by next-generation sequencing sequencing (NGS) between 2018-2019. SS was used to analyze resistance mutations in the protease (PR) and reverse transcriptase (RT) gene regions using a ViroSeq HIV-1 Genotyping System. PCR products were analyzed with an ABI3500 GeneticAnalyzer (Applied Biosystems). The sequencing of the HIV genome in the PR, RT, and integrase gene regions was carried out using MiSeq NGS technology. Drug resistance mutations and subtypes were interpreted using the Stanford University HIV-1 drug resistance database. RESULTS: Transmitted drug resistance (TDR) mutation was detected in 34/814 (4.1 %) samples. Nonnucleoside reverse transcriptase inhibitor (NNRTI), nucleoside reverse transcriptase inhibitor (NRTI), and protease inhibitor (PI) mutations were identified in 1.4 % (n =12), 2.4 % (n =20), and 0.3 % (n = 3) of samples, respectively. The most common subtypes were B (53.1 %), A (10.9%), CRF29_BF (10.6%), and B + CRF02_AG (8,2%). The most common TDR mutations were E138A (3.4%), T215 revertants (1.7%), M41L (1.5%), and K103N (1.1%). CONCLUSION: Transmitted drug resistance rate in the Aegean Region is compatible with national and regional data. Routine surveillance of resistance mutations may guide the safe and correct selection of initial drug combinations for antiretroviral therapy. The identification of HIV-1 subtypes and recombinant forms in Turkey may contribute to international molecular epidemiological data.


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Soropositividade para HIV , HIV-1 , Humanos , Inibidores da Transcriptase Reversa/uso terapêutico , HIV-1/genética , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Prevalência , Turquia/epidemiologia , Farmacorresistência Viral/genética , Mutação , Soropositividade para HIV/tratamento farmacológico , Genótipo , Fármacos Anti-HIV/farmacologia , Fármacos Anti-HIV/uso terapêutico
6.
J Environ Manage ; 113: 432-9, 2012 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-23102644

RESUMO

Octanol-air partition coefficients (K(OA)) for 7 organochlorine pesticides (OCPs) were determined as a function of temperature using the GC retention time method. Log K(OA) values at 25 °C ranged over two orders of magnitude, between 8.32 (chlorpyrifos) and 10.48 (methoxychlor). The determined K(OA) values were within a factor of 0.5 (endosulfan sulfate) to 7.9 (endrin aldehyde) for values calculated as the ratio of octanol-water partition coefficient to dimensionless Henry's law constant. The internal energies of phase transfer between octanol and air (ΔU(OA)) ranged between 71.8 and 95.4 kJ mol(-1) and they were within the reported range for OCPs (55.8-105 kJ mol(-1)). Atmospheric and soil OCP concentrations were also measured in Izmir, Turkey, and data used to investigate the soil-air gas exchange. Net soil-air gas exchange fluxes of OCPs ranged from -0.01 (volatilization, cis-nonachlor) to 56.4 ng m(-2) day(-1) (deposition, chlorpyrifos) in winter, while in summer they ranged from -0.03 (trans-nonachlor) to 329 ng m(-2) day(-1) (endosulfan I). In both sampling periods, endosulfan I and II, trans-nonachlor, p,p'-DDD and p,p'-DDT were generally deposited to the soil while γ-HCH and heptachlor epoxide mostly volatilized. Fluxes of other OCPs were variable (volatilization or absorption) due to their largely fluctuating ambient air concentrations. Calculated dry deposition and recently measured wet deposition fluxes were used to estimate the relative importance of different mechanisms (i.e., dry deposition, wet deposition, gas absorption, and volatilization) to the local soil pollutant inventory. Generally, all mechanisms contributed significantly to the soil OCP inventory. Volatilization fluxes were generally much lower than the sum of input fluxes (dry deposition, wet deposition and gas absorption) for most of the OCPs indicating a net deposition to the soil.


Assuntos
Ar/análise , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Solo/análise , Geografia , Éteres Difenil Halogenados/análise , Modelos Teóricos , Temperatura
7.
Med Mycol ; 49(1): 26-31, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20662635

RESUMO

This study was planned to determine the risk factors of candidemia, and the most common Candida species causing bloodstream infections. A case-control study which included adult patients was conducted over a 1-year period at tertiary-care educational hospitals in Turkey. A total of 83 candidemia episodes were identified during the study period. Candida albicans was the most common species recovered (45.8%) followed by Candida tropicalis (24.1%) Candida parapsilosis (14.5%) and Candida glabrata which was isolated from only four (4.8%) patients. Presence of a urethral catheter (odds ratio [OR] 2.38; 95% confidence interval [CI] 1.09-5.19; P = 0.02), previous use of antibiotics (OR 2.61; 95% CI 1.05-6.46; P = 0.03), RBC transfusions (OR 2.14; 95% CI 1.16-3.94; P = 0.01) and parenteral nutrition (OR 4.44; 95% CI 2.43-8.11; P < 0.01) were found as independent risk factors for candidemia. TPN (Total Parenteral Nutrition) was an independent risk factor for both C. albicans and non-Candida albicans Candida species (P < 0.001). Most of the risk factors were invasive procedures and former medications. We conclude that a great number of candidemia cases are preventable by means of reduction of unnecessary invasive procedures and the use of antimicrobials.


Assuntos
Candida/classificação , Candida/isolamento & purificação , Candidemia/epidemiologia , Candidemia/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Hospitais Universitários , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Turquia/epidemiologia , Adulto Jovem
8.
Sci Total Environ ; 646: 1164-1171, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30235602

RESUMO

Polybrominated diphenyl ethers (PBDEs) were investigated in ambient air of a highly industrialized region at 23 different sampling sites for 12 months. Total concentrations of 8 PBDE congeners (Σ8PBDE) were found to be between 5.73 and 520 pg m-3 (94.7 ±â€¯78.9; average ±â€¯SD) and BDE-209 was the predominant congener, followed by BDE-47 and/or BDE-99. Their contributions to Σ8PBDE were 71 ±â€¯13, 9 ±â€¯4% and 8 ±â€¯4%; respectively. Compared to previous studies around the world, high concentrations detected in Dilovasi demonstrated the severity of atmospheric PBDE pollution in the area. For all sampling sites, average PBDE concentration obtained in summer (118.5 ±â€¯98.7 pg m-3) was higher than one found in winter period (79.7 ±â€¯59.1 pg m-3) and this seasonal difference was more obvious in industrial/urban sites (p < 0.05), probably due to enhanced volatilization from ongoing PBDE sources such as waste incineration and iron-steel plants. The soil-air exchange tendencies of PBDEs did not show substantial differences between the sampling periods with small variations for each congener. All congeners either tend to deposit to soil or to be within the equilibrium range for all seasons. This reflects the impact of local ongoing sources rather than temperature on the direction of soil-air exchange of PBDEs in this region. Specific congener ratios such as BDE-47/-99 and -99/-100 confirmed the impact of local sources rather than long-range transport on PBDE congeners in the study area. According to the Positive Matrix Factorization (PMF) results, the BDE-209 content of the first factor was found to be 91.7% and this factor was attributed to the deca-BDE technical formulations. The second factor was highly rich with both BDE-183 (%61) and BDE-28 (%52) and identified as octa-BDE technical products. The last factor was highly loaded with BDE-99, BDE-47, BDE-100, BDE-154 and BDE-153 and has been determined as the penta-BDE commercial formulations.

9.
Chemosphere ; 71(6): 1067-78, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18068209

RESUMO

Atmospheric concentrations of 7 PBDE congeners (BDE-28, -47, -99, -100, -153, -154 and -209) were determined at four sites (i.e. Suburban, Urban 1, Urban 2, Industrial) in Izmir, Turkey and their gas/particle partitioning was investigated. Total PBDE ( summation operator(7)PBDE) concentrations ranged between 11 (Urban 1) and 149pgm(-3) (Industrial) in summer, while in winter, they ranged from 6 (Suburban) to 81pgm(-3) (Industrial). BDE-209 was the dominant congener at all sites, followed by BDE-99 and -47. Investigation of source profiles indicated that the air samples were dominated by congeners of the penta and deca-technical BDE mixtures. The measured PBDE particle fractions were compared to the predictions of the K(OA) (octanol-air partition coefficient)-based equilibrium partitioning model and to the dynamic uptake model developed by others for passive samplers, which was adapted to model gas-particle partitioning in this study. For BDE-28, good agreement was observed between the experimental particle fractions and those predicted by the equilibrium partitioning model. However, this model overestimated the particle fractions of other congeners. The predictions of the dynamic uptake model supported the hypothesis that the unexpectedly high partitioning of BDEs (except BDE-28) to the gas-phase is due to their departure from equilibrium partitioning. When congeners with very large octanol-air partition coefficients (i.e. BDE-100, -99, -154, -153, and -209) are emitted from their sources in the gas-phase, they may remain in that phase for several months before reaching equilibrium with atmospheric particles. This may also have important implications for the transport of atmospheric PBDEs. For example, in addition to particle-bound transport, the gas-phase transport of highly brominated congeners (i.e. BDE-209) may also be important.


Assuntos
Poluentes Atmosféricos/análise , Bifenil Polibromatos/análise , Poluentes Atmosféricos/química , Monitoramento Ambiental , Éteres Difenil Halogenados , Éteres Fenílicos/análise , Éteres Fenílicos/química , Bifenil Polibromatos/química , Turquia
10.
Saudi Med J ; 29(5): 728-33, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18454223

RESUMO

OBJECTIVE: To investigate if combination therapy with liposomal amphotericin B (LAmB), and caspofungin (CAS) is superior to monotherapies in an experimental model with azole-resistant Candida albicans. METHODS: This study was carried out between October 2006 and August 2007 in Celal Bayar University, Manisa, Turkey. A total of 144 mice were included in the study, and divided into 4 groups as: control (n=36), CAS treatment group n=36, LAmB treatment group (n=36), and combination therapy group (n=36). Treatment efficacy was assessed by determining survival, as well as, the decrease in tissue fungal densities. RESULTS: The fungal densities in tissues were significantly reduced, and the survival rates were prolonged with either CAS only, or LAmB only, or with combination therapy compared to those of controls (p<0.05). There was no significant difference between monotherapy groups. Decrease in tissue fungal densities were significant in CAS and LAmB (1mg/kg) combination group, compared to CAS (1mg/kg) and LAmB (1mg/kg) groups (p=0.004 for CAS, p=0.009 for LAmB). Survival rates were similar in both treatment groups. CONCLUSION: The combination treatment was superior with 1mg/kg of doses of LAmB and CAS in terms of reducing the tissue fungal burden. Although with combination therapy the survival rates prolonged in all subgroups, no significant difference between the combination and monotherapies could be shown. Additional studies with a large number of cases are warranted to investigate the superiority of combination therapy.


Assuntos
Anfotericina B/farmacologia , Candidíase/tratamento farmacológico , Equinocandinas/farmacologia , Anfotericina B/administração & dosagem , Animais , Caspofungina , Quimioterapia Combinada , Equinocandinas/administração & dosagem , Lipopeptídeos , Camundongos , Estatísticas não Paramétricas , Taxa de Sobrevida
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA