23 research outputs found

    Carbon-cryogel hierarchical composites as effective and scalable filters for removal of trace organic pollutants from water

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    Effective technologies are required to remove organic micropollutants from large fluid volumes to overcome present and future challenges in water and effluent treatment. A novel hierarchical composite filter material for rapid and effective removal of polar organic contaminants from water was developed. The composite is fabricated from phenolic resin-derived carbon microbeads with controllable porous structure and specific surface area embedded in a monolithic, flow permeable, poly(vinyl alcohol) cryogel. The bead-embedded monolithic composite filter retains the bulk of the high adsorptive capacity of the carbon microbeads while improving pore diffusion rates of organic pollutants. Water spiked with organic contaminants, both at environmentally relevant concentrations and at high levels of contamination, was used to determine the purification limits of the filter. Flow through tests using water spiked with the pesticides atrazine (32 mg/L) and malathion (16 mg/L) indicated maximum adsorptive capacities of 641 and 591 mg pollutant/g carbon, respectively. Over 400 bed volumes of water contaminated with 32 mg atrazine/L, and over 27,400 bed volumes of water contaminated with 2 μg atrazine/L, were treated before pesticide guideline values of 0.1 μg/L were exceeded. High adsorptive capacity was maintained when using water with high total organic carbon (TOC) levels and high salinity. The toxicity of water filtrates was tested in vitro with human epithelial cells with no evidence of cytotoxicity after initial washing

    Comparison of two volumetric techniques for estimating volume of intracerebral ventricles using magnetic resonance imaging: a stereological study

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    The size of brain ventricles is especially relevant in some brain diseases such as epilepsy, schizophrenia and other neurodegenerative diseases. Many studies have been conducted to assess the brain ventricles. To the best of our knowledge, however, there is no fourth, third and lateral ventricles volume study evaluating the efficiency and accuracy of point-counting and planimetry methods of the Cavalieri principle in the literature. In the current study, we estimated the volume of intracerebral ventricles in normal subjects using stereological methods. The volumes of fourth, third and lateral ventricle were estimated in 14 young Turkish volunteers ( 7 males and 7 females), aged between 18 and 36 years and free of any neurological symptoms and signs, using serial magnetic resonance imaging (MRI). Volumes of intracerebral ventricles were determined on MRIs using the point-counting and planimetry methods. The mean results of the point-counting method were 14.7 +/- 4.2, 8.7 +/- 3.0 and 131.8 +/- 33.1 mm(3) for the fourth, third and lateral ventricles, respectively. The mean results of the planimetry method were 15.4 +/- 3.4, 8.6 +/- 3.5 and 153.7 +/- 34.6 mm(3) for the fourth, third and lateral ventricles, respectively. Ventricle volumes obtained by the two different methods were not statistically different ( p > 0.05) and they correlated well with each other. Good agreement was found between results obtained with the point-counting and planimetry techniques. The findings of the present study using stereological methods could provide data for the evaluation of normal and pathological volumes of intracerebral ventricles. The size of brain ventricles is especially relevant in some brain diseases such as epilepsy, schizophrenia and other neurodegenerative diseases. Many studies have been conducted to assess the brain ventricles. To the best of our knowledge, however, there is no fourth, third and lateral ventricles volume study evaluating the efficiency and accuracy of point-counting and planimetry methods of the Cavalieri principle in the literature. In the current study, we estimated the volume of intracerebral ventricles in normal subjects using stereological methods. The volumes of fourth, third and lateral ventricle were estimated in 14 young Turkish volunteers (7 males and 7 females), aged between 18 and 36 years and free of any neurological symptoms and signs, using serial magnetic resonance imaging (MRI). Volumes of intracerebral ventricles were determined on MRIs using the point-counting and planimetry methods. The mean results of the point-counting method were 14.7 +/- 4.2, 8.7 +/- 3.0 and 131.8 +/- 33.1 mm(3) for the fourth, third and lateral ventricles, respectively. The mean results of the planimetry method were 15.4 +/- 3.4, 8.6 +/- 3.5 and 153.7 +/- 34.6 mm(3) for the fourth, third and lateral ventricles, respectively. Ventricle volumes obtained by the two different methods were not statistically different (p &gt; 0.05) and they correlated well with each other. Good agreement was found between results obtained with the point-counting and planimetry techniques. The findings of the present study using stereological methods could provide data for the evaluation of normal and pathological volumes of intracerebral ventricles.</p

    Evaluation of leukocyte arylsulphatase A, serum interleukin-6 and urinary heparan sulphate following tamoxifen therapy in breast cancer

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    Leukocyte arylsulphatase A (AS-A) was shown to be significantly high in newly-diagnosed breast cancer patients. Previous reports imply a connection between serum interleukin-6 (IL-6) and breast cancer, possibly through a modulation of enzymes involved in estrogen synthesis. Abnormal distribution of heparan sulphate proteoglycans (HSPGs) in malignant breast epithelial cells suggests that they play a key role in the regulation of cell growth. Estradiol is believed to be effective in modulating glycosaminoglycans (GAGs) and their depolymerizing enzymes. Therefore, in this study, attempts were made to evaluate the activity of leukocyte arylsulphatase A, serum interleukin-6, urinary GAGs and heparan sulphate (HS) in response to tamoxifen (TAM) therapy in mastectomised breast cancer patients. Thirty-four patients (aged 30-82 years) were administered TAM (20 mg twice daily). Blood and urine samples of each patient were collected three times (at the beginning, and in third and sixth month of TAM therapy), and biochemical parameters were measured. There was no difference between baseline leukocyte AS-A activity and that measured after three months. At the end of six months, enzyme activity was significantly higher than the former values (p = 0.022), but within the reference intervals reported in the literature. Although this increase might imply a normalization, the duration of TAM therapy is not long enough to make a decision about either regression or aggravation of the disease. TAM did not have any effect on serum IL-6, urinary HS and GAG levels which may be due to insensitivity of these variables to TAM during the short period of therapy. Both urinary GAG and HS levels measured at sixth month exhibited a positive correlation with the baseline level of leukocyte AS-A (P = 0.005 and 0.009, respectively), suggesting that positive responses to the drug might be seen in patients with low AS-A activity. (c) 2005 Elsevier Ltd. All rights reserved
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