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Результаты 4191-4200 из 4,309
Aryl hydrocarbon receptor gene transitions (c.-742C>T; c.1661G>A) and idiopathic male infertility: a case-control study with in silico and meta-analysis Полный текст
2017
Aftabi, Younes | Hosseinzadeh Colagar, Abasalt | Mehrnejad, Faramarz | Seyedrezazadeh, Ensiyeh | Moudi, Emadoddin
Aryl hydrocarbon receptor (AHR) is responsible for crucial events in male reproductive biology. Here, the association of the AHR transitions c.-742C>T and c.1661G>A with idiopathic male infertility was investigated in a case-control study, which is followed by a meta-analysis and a bioinformatic investigation. Blood and semen samples were obtained from a total of 135 idiopathic infertile men and 130 healthy controls. Participants were genotyped for the transitions using a PCR-RFLP method. A meta-analysis of five sets of data evaluated the association of c.1661G>A with male infertility, and using an in silico analysis, the possible molecular effects of the transitions predicted. Genotypes and alleles of AHR-c.-742C>T and c.1661G>A polymorphisms were not associated with the risk of male infertility significantly. However, the frequency of C/A haplotype was significantly associated with the increased risk of male infertility, and T/A haplotype was higher among controls significantly. Also, the frequencies of combined genotypes CT/GG, CT/GA and TT/GG were significantly associated with decreased risk of infertility. And, the meta-analysis showed that the AA versus GA/GG recessive model is associated with decreased risk of male infertility among the Iranian population. In silico analysis predicted that c.-742C>T does not alter the binding sites of the proposed transcription factors, but c.1661G>A poses a tolerable structural disturbance in AHR protein. In conclusion, these results showed that AHR c.-742C>T and c.1661G>A transitions separately could not be nominated as a risk or protective factor for male infertility. However, some combined models could affect infertility risk, especially among Iranian men.
Показать больше [+] Меньше [-]A model for determination of operational conditions for successful shortcut nitrification Полный текст
2017
Liu, Xiaoguang | Kim, Mingu | Nakhla, George
Accumulation of nitrite in shortcut nitrification is influenced by several factors including dissolved oxygen concentration (DO), pH, temperature, free ammonia (FA), and free nitrous acid (FNA). In this study, a model based on minimum dissolved oxygen concentration (DOₘᵢₙ), minimum/maximum substrate concentration (Sₘᵢₙ and Sₘₐₓ), was developed. The model evaluated the influence of pH (7–9), temperature (10–35 °C), and solids retention time (SRT) (5 days–infinity) on MSC values. The evaluation was conducted either by controlling total ammonium nitrogen (TAN) or total nitrite nitrogen (TNN), concentration at 50 mg N/L while allowing the other to vary from 0 to 1000 mg N/L. In addition, specific application for shortcut nitrification-anammox process at 10 °C was analyzed. At any given operational condition, the model was able to predict if shortcut nitrification can be achieved and provide the operational DO range which is higher than the DOₘᵢₙ of AOB and lower than that of NOB. Furthermore, experimental data from different literature studies were taken for model simulation and the model prediction fit well the experiment. For the Sharon process, model prediction with default kinetics did not work but the model could make good prediction after adjusting the kinetic values based on the Sharon-specific kinetics reported in the literature. The model provides a method to identify feasible combinations of pH, DO, TAN, TNN, and SRT for successful shortcut nitrification.
Показать больше [+] Меньше [-]Health risks of environmental exposure to metals and herbicides in the Pardo River, Brazil Полный текст
2017
Machado, Carolina S. | Fregonesi, Brisa M. | Alves, Renato I. S. | Tonani, Karina A. A. | Sierra, Jordi | Martinis, Bruno S. | Celere, Beatriz S. | Mari, Montse | Schuhmacher, Marta | Nadal, Martí | Domingo, Jose L. | Segura-Muñoz, Susana
Mixture of metals and herbicides in rivers may pose relevant risks for the health of surrounding communities. Humans may be exposed to river pollution through intake of contaminated water and fish, as well as irrigated agricultural products. The aim of this study was to assess the human health risks of environmental exposure to metals and herbicides through water and fish intake in the Pardo River. Metals (Al, As, Be, Cd, Cr, Cu, Pb, Mn, Hg, Ni, Tl, Sn, V, and Zn) were analyzed in river water and in edible fish. Herbicides (ametryn, atrazine, diuron, hexazinone, simazine, and tebuthiuron) were analyzed in river water. Seasonal variances were also studied. Aluminum, Cd, Cu, Mn, Pb, and Zn levels in river water were higher than the USEPA benchmarks. Non-carcinogenic risks due to pollutants mixture exposure were above the limit, and carcinogenic risks of As exposure were >10⁻⁶ in the sampling points during the rainy season. Metal levels in fish were lower than the Brazilian legislation and do not pose a threat to public health. Herbicides were detected in four sampling points, with atrazine concentrations (range 0.16–0.32 μg/L) below the Brazilian standard (2.0 μg/L), but above the European Union standard (0.1 μg/L). Considering the water supply needs of cities located in the Pardo River Basin and the persistence of metals and herbicides, the present study indicated that there was a seasonal influence on non-carcinogenic and carcinogenic risks to human health, especially in the rainy season. Studies for water treatment plants implantation should consider the risks of exposure to persistent substances, in order to protect the population.
Показать больше [+] Меньше [-]Decline patterns and risk assessment of 10 multi-class pesticides in young sprout amaranth (Amaranthus mangostanus) under greenhouse growing conditions Полный текст
2017
Kim, In Kyung | Kim, Sung-woo | Abd El-Aty, A. M. | Rahman, Md Musfiqur | Kabir, Md Humayun | Lee, Han Sol | Chung, Hyung Suk | Jeong, Ji Hoon | Shin, H.-C. (Ho-Chul) | Shim, Jae-Han
The present study was designed to investigate the residual decline pattern and the risk assessment of 10 different class pesticides, namely azoxystrobin, boscalid, diazinon, diethofencarb, difenoconazole, etofenprox, flubendiamide, paclobutrazol, and pyraclostrobin in young vegetative amaranth (Amaranthus mangostanus) sprayed once or twice under greenhouse growing conditions. Field-incurred samples, collected at 3, 7, or 10 days after application of both treatments, were extracted and purified with the quick, easy, cheap, effective, rugged, and safe “QuEChERS” citrate-buffered method and analyzed with liquid chromatography-electrospray ionization tandem mass spectrometry (LC-MS/MS) in positive ion mode. The linearity was satisfactory with determination coefficients (R ²) falling between 0.9817 and 0.9999 and limits of detection (LOD) and quantification (LOQ) values of 0.0007 and 0.002 mg/kg, respectively. The mean recovery rate at four spiking levels (equivalent to 5, 10, 50, and 100 × LOQ) ranged from 78.1 to 131.6% with a relative standard deviation (RSD) of < 11%. Substantial differences in the initial deposit between the tested analytes were observed and clearly indicated that the structure, as well as the initial concentration of applied products, greatly affected the residue deposit. From the obtained residual data, the provisional marginal maximum residue limits (MRLs) and the pre-harvest intervals (PHI) were proposed. Risk assessment was evaluated by comparing the theoretical maximum daily intake (TMDI) with the acceptable daily intake (ADI). Herein, the TMDI was lower than the ADI (TMDI/ADI ratio ≤ 80% set by the Korean Ministry of Food and Drug Safety) except for difenoconazole (80.92%, marginally higher), indicating that the vegetative amaranth is not hazardous and can be consumed safely by Korean consumers.
Показать больше [+] Меньше [-]Electrochemical treatment of shrimp farming effluent: role of electrocatalytic material Полный текст
2017
de Menezes, Francisco Leonardo Gomes | da Silva, André Jailson Cabral | Martínez-Huitle, Carlos Alberto | Zanta, Carmem Lúcia Paiva Silva | Alves, Janete Jane Fernandes | Castro, Suely Souza Leal
This study investigated the electrochemical oxidation of organic matter present in shrimp farming effluent using three types of electrocatalytic materials: Ti/Ru₀.₃₄Ti₀.₆₆O₂, Ti/Pt, and boron-doped diamond (BDD). An electrochemical cell with 300 mL under stirring agitation was used by applying 20, 40, and 60 mA cm⁻². A Ti/Ru₀.₃₄Ti₀.₆₆O₂ anode showed a reduction of chemical oxygen demand (COD) about 84 % after 1 h of electrolysis, while at the same time, 71 % of COD decay was achieved at Ti/Pt. Conversely, only 71 % of COD was removed after 2 h with a BDD anode. Regarding the temperature effect, BDD showed better performances than those achieved for Ti/Ru₀.₃₄Ti₀.₆₆O₂ and Ti/Pt anodes during an electrochemical treatment of a shrimp farming effluent, obtaining 72 % of COD removal by applying 20 mA cm⁻² at 40 °C after 15 min. Energy consumption and cost were estimated in order to established the engineering applicability of this alternative process.
Показать больше [+] Меньше [-]Photodegradation of ethylene by use of TiO2 sol-gel on polypropylene and on glass for application in the postharvest of papaya fruit Полный текст
2017
Lourenço, Ruth Evelyn R. S. | Linhares, Amanda A. N. | de Oliveira, André Vicente | da Silva, Marcelo Gomes | de Oliveira, Jurandi Gonçalves | Canela, Maria Cristina
The papaya is a commercially important fruit commodity worldwide. Being a climacteric fruit, it is highly perishable. Thus, for the transportation of papaya fruit for long distances without loss of quality, it is necessary to avoid the autocatalytic effect of ethylene in accelerating the ripening of the fruit. This work addresses the application of heterogeneous photocatalysis to the degradation of ethylene. A TiO₂ sol-gel supported on polypropylene (PP) and on glass was used as the catalytic material, and a UV-A lamp was employed as the radiation source. Initially, a concentration of 500 ppbv ethylene was exposed to the catalyst material irradiated by UV-A radiation. A sensitive photoacoustic spectrometer was used to monitor the photocatalytic activity. The TiO₂ sol-gel supported on the glass substrate was more efficient than on the PP in degrading the ethylene. Under direct UV-A exposure, the skin appearance of ‘Golden’ papaya was damaged, depreciating the fruit quality and thus preventing its commercialization. However, the feasibility of the heterogeneous photocatalysis to preserve the fruit quality was achieved when ethylene was removed from the storage ambient using fans, and then, this plant hormone was degraded by a reactor set apart in a ventilation closed system.
Показать больше [+] Меньше [-]Tracking fluorescent components of dissolved organic matter from soils in large-scale irrigated area Полный текст
2017
Pan, Hongwei | Yu, Huibin | Song, Yonghui | Zhu, Lin | Liu, Ruixia | Du, Erdeng
Combination of fluorescence excitation-emission matrix spectroscopy with parallel factor analysis (PARAFAC) and principal component analysis (PCA) was engaged to track fluorescent components of dissolved organic matter (DOM) extracted from soils, to seek potential factors, and to reveal their correlations with physico-chemical properties of soils. Soil samples at different depths were collected in Hetao irrigated area of Inner Mongolia, China. Five fluorescent components (C1 to C5) were identified by PARAFAC modeling of DOM extracted from the soil samples. C1 was referred as fulvic-like fluorescent component, by which DOM was dominated in the whole soil samples. C2 was associated with salinity and agriculture, which was similar to marine humic-like fluorescent component. C3 was assigned as traditional humic-like fluorescent component. The three components were of the terrestrial origin. C4 was involved in tryptophan-like fluorescent component, which was autochthonous productions of biological degradation. C5 might be a polycyclic aromatic hydrocarbon contaminant, which could be relative to anthropogenic sources of pesticides. The C1, C2, and C3 were the potential factors of characterizing DOM fractions using PCA on fluorescent components and physico-chemical parameters. Moreover, DOM might restrained by exchangeable sodium percentage, and its formation and decomposition might be influenced by soil moisture.
Показать больше [+] Меньше [-]Detoxification effects of phytonutrients against environmental toxicants and sharing of clinical experience on practical applications Полный текст
2017
Chung, Raymond Tsz Man
According to the Food and Health Bureau and Trade and Industry Department of the Hong Kong Government, 90 % of the total food supply in Hong Kong was imported from the Mainland China. In addition, the hidden or illegal use of prohibited pesticides, food adulteration (e.g., using industrial salt in food processing, using gutter oil as cooking oil), and pollutions were periodically reported by the media. Excessive exposure to toxic heavy metals or persistent organic pollutants (POPs) from diet or environmental is inevitable amid industrialization and pollution. Understanding of the detoxification ability among nutrients in plant-based food (i.e., phytonutrients in green tea, onion, garlic, coriander, and turmeric) offers therapeutic and preventive effects against the poisoning effects due to these pollutants. Oxidative stress and pro-inflammatory actions are the common mechanisms for heavy metals or POPs toxicities, while phytonutrients counteracts these cellular insults by anti-oxidation, upregulation of anti-inflammatory pathways, and chelation.
Показать больше [+] Меньше [-]Multivariate analysis and geochemical approach for assessment of metal pollution state in sediment cores Полный текст
2017
Jamshidi-Zanjani, Ahmad | Saeedi, Mohsen
Vertical distribution of metals (Cu, Zn, Cr, Fe, Mn, Pb, Ni, Cd, and Li) in four sediment core samples (C₁, C₂, C₃, and C₄) from Anzali international wetland located southwest of the Caspian Sea was examined. Background concentration of each metal was calculated according to different statistical approaches. The results of multivariate statistical analysis showed that Fe and Mn might have significant role in the fate of Ni and Zn in sediment core samples. Different sediment quality indexes were utilized to assess metal pollution in sediment cores. Moreover, a new sediment quality index named aggregative toxicity index (ATI) based on sediment quality guidelines (SQGs) was developed to assess the degree of metal toxicity in an aggregative manner. The increasing pattern of metal pollution and their toxicity degree in upper layers of core samples indicated increasing effects of anthropogenic sources in the study area.
Показать больше [+] Меньше [-]Can toxicants used against cotton mealybug Phenacoccus solenopsis be compatible with an encyrtid parasitoid Aenasius bambawalei under laboratory conditions? Полный текст
2017
Badshah, Hayat | Ullah, Farman | Calatayud, Paul Andre | Ullah, Hidayat | Ahmad, Bashir
The cotton mealybug, Phenacoccus solenopsis Tinsley (Sternorrhyncha: Pseudococcidae) is a serious pest of various cultivated plants in Pakistan. Recent reports show that the parasitoid Aenasius bambawalei Hayat (Hymenoptera: Encyrtidae) is a good biocontrol agent of the pest. Compatibleness is important in any IPM programme, and the insecticide used must have little or no effects on the biological control agent. This study investigated the compatibility of neem treatments and a commercial insecticide, imidacloprid on A. bambawalei. Bioassays were laid out in a completely randomized design (CRD) under laboratory conditions. Results showed that the adult stage of the parasitoid was more susceptible to the commercial insecticide imidacloprid than the concealed pupal stage. Moreover, on the basis of the International Organization for Biological Control (IOBC) toxicity categories of the commercial insecticide, imidacloprid was moderately toxic throughout the study period (Ex >80%) while neem was slightly toxic after 24 h of use (Ex <80%). Results also suggest that A. bambawalei release should be delayed for at least 1 week after neem treatments. Because imidacloprid destroys A. bambawalei, it might cause resurgence of P. solenopsis; thus, farmers should avoid integrating the insecticide in the control of P. solenopsis.
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