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1.
J Mycol Med ; 25(1): e25-30, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25467819

RESUMO

Hemolytic activity was recently reported for several pathogenic fungal species, such as Aspergillus, Candida, Trichophyton, Penicillium and Fusarium. Based on a number of mechanistic and characterization studies, several fungal hemolysins have been proposed as virulence factors. Hemolysins lyse red blood cells resulting in the release of iron, an important growth factor for microbes especially during infection. The requirement of iron in fungal growth is necessary for metabolic processes and as a catalyst for various biochemical processes. Expression of a hemolytic protein with capabilities to lyse red blood cells has also been suggested to provide a survival strategy for fungi during opportunistic infections. The aims of this study were to investigate the hemolytic activities of dermatophytes species isolated from patients with dermatophytosis. Hair, skin and nail samples of patients were examined with direct microscopy using potassium hydroxide and cultivated on Mycobiotic agar and Sabouraud's dextrose agar. To determine hemolytic activities of dermatophytes species, they were subcultured on Columbia Agar with 5% sheep blood and incubated for 7-14 days at 25°C in aerobic conditions. Media which displayed hemolysis were further incubated for 1-5 days at 37°C to increase hemolytic activity. In this study, 66 dermatophytes strains were isolated from clinical specimens and were identified by six different species: 43 (65.1%) Trichophyton rubrum, 7 (10.7%) Trichophyton mentagrophytes, 5 (7.6%) Microsporum canis, 5 (7.6%) Trichophyton tonsurans, 4 (6.0%) Epidermophyton floccosum and 2 (3.0%) Trichophyton violaceum. Twenty-one T. rubrum strains showed incomplete (alpha) hemolysis and nine T. rubrum strains showed complete (beta) hemolysis, whereas hemolysis was absent in 13 T. rubrum strains. Four T. mentagrophytes strains showed complete hemolysis and three T. tonsurans strains showed incomplete hemolysis. However, M. canis, E. floccosum and T. violaceum species had no hemolytic activity. Hemolytic activity is pronounced in dermatophytes and may play an important role as a virulence factor. Hemolysins produced may play an important role in the balance between the host's cellular immunity and the ability of the fungus to diminish the immune response.


Assuntos
Arthrodermataceae/fisiologia , Hemólise , Tinha/microbiologia , Adolescente , Adulto , Idoso , Animais , Arthrodermataceae/isolamento & purificação , Epidermophyton/isolamento & purificação , Epidermophyton/fisiologia , Feminino , Hemólise/efeitos dos fármacos , Hemolíticos/isolamento & purificação , Hemolíticos/metabolismo , Humanos , Masculino , Microsporum/isolamento & purificação , Microsporum/fisiologia , Pessoa de Meia-Idade , Trichophyton/isolamento & purificação , Trichophyton/fisiologia , Adulto Jovem , Zoonoses/microbiologia
2.
J Mycol Med ; 24(4): 313-8, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25442917

RESUMO

World is endowed with a rich wealth of medicinal plants. There is a widespread belief that green medicines are healthier and more harmless or safer than synthetic ones. Medicinal plants have been used to cure a number of diseases. The ancient plant Lawsonia inermis or henna is used as medicinal plant because of its attributed strong fungicidal, anti-inflammatory, analgesic, antibacterial, virucidal, antiparasitic, antiamoebiasis, astringent, antihemorrhagic, hypotensive, sedative, anticancer effect and possible anti-sweating properties. In this study, we investigated antifungal activity of L. inermis against clinical dermatophytes species. This study was carried out using 70 clinical isolates of dermatophytes representing six different species; 44 Trichophyton rubrum, 8 Trichophyton mentagrophytes, 6 Microsporum canis, 6 Trichophyton tonsurans, 4 Epidermophyton floccosum, and 2 Trichophyton violaceum. The antifungal activity of L. inermis (henna) was determined by agar diffusion method and henna was used as paste form. Henna paste showed the high antifungal activity against all dermatophytes species (20 to 50mm inhibition zone).


Assuntos
Antifúngicos/farmacologia , Arthrodermataceae/efeitos dos fármacos , Lawsonia (Planta)/química , Extratos Vegetais/farmacologia , Adolescente , Adulto , Idoso , Arthrodermataceae/crescimento & desenvolvimento , Arthrodermataceae/isolamento & purificação , Dermatomicoses/epidemiologia , Dermatomicoses/microbiologia , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Adulto Jovem
3.
Hum Exp Toxicol ; 32(10): 1107-16, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23925941

RESUMO

An overdose of acetaminophen (APAP) produces centrilobular hepatocellular necrosis. We aimed to investigate the hepatoprotective effects of N-acetylcysteine (NAC) only and hyperbaric oxygen (O(2)) treatment (HBOT) combined with NAC, and their anti-inflammatory properties in liver tissue. In the current study, a total of 32 male Sprague Dawley rats were divided into 4 groups: sham, APAP, NAC, and NAC + HBOT. In the APAP, NAC, and NAC + HBOT groups, liver injury was induced by oral administration of 1 g/kg APAP. The NAC group received 100 mg/kg NAC per day. NAC + HBOT group received intraperitoneal injection of 100 mg/kg/day NAC and were given HBOT at 2.8 ATA pressure with 100% O(2) inhalation for 90 min every 12 h for 5 days. Rats in the sham group received distilled water only by gastric tube. All animals were killed on day 6 after APAP or distilled water administration. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities, hepatic neopterin, tumor necrosis factor-α (TNF-α), and interleukin 6 (IL-6) levels were measured. There was a significant increase in serum AST and ALT activities in the APAP group compared with the sham group (in both p = 0.001). NAC and NAC + HBOT groups had significant decreases in hepatic neopterin, TNF-α, and IL-6 levels compared with the APAP group. APAP administration caused extensive hepatic necrosis. NAC and NAC + HBO treatments significantly reduced APAP-induced liver injury. Our results showed that the liver damage in APAP toxicity was attenuated by NAC and NAC + HBO treatments. NAC + HBOT exhibit hepatoprotective activity against APAP-induced liver injury in rats.


Assuntos
Acetaminofen , Acetilcisteína/uso terapêutico , Analgésicos não Narcóticos , Doença Hepática Induzida por Substâncias e Drogas/terapia , Oxigenoterapia Hiperbárica , Substâncias Protetoras/uso terapêutico , Acetilcisteína/farmacologia , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Modelos Animais de Doenças , Interleucina-6/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Neopterina/metabolismo , Substâncias Protetoras/farmacologia , Ratos , Ratos Sprague-Dawley , Fator de Necrose Tumoral alfa/metabolismo
4.
Bioresour Technol ; 117: 48-54, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22609713

RESUMO

The main goal of this study was to control the fouling phenomena in MBR using chemical additives. In the first phase of the study, SMP removal and bound EPS formation capacity of chemical additives were determined. Highest SMP removal (72%) was achieved by the Poly-2 additive. In the second phase of the study, short term filtration tests were conducted. Poly-1 exhibited highest performance based on membrane resistance, permeability and average TMP. According to the results obtained from constant shear rate tests in fourth phase, no significant change in viscosity with time was observed. Studies for the adaptation of rheograms to common flow models showed that chitosan and starch was not able to fit to Ostwald de Waele and Bingham models. At a shear rate of 73.4 s(-1) viscosities of all samples were close to each other. Chitosan and starch achieved highest viscosity values at the shear rate of 0.6 s(-1).


Assuntos
Biopolímeros/química , Reatores Biológicos , Filtração/instrumentação , Filtração/métodos , Membranas Artificiais , Reologia/instrumentação , Esgotos/química , Bactérias/metabolismo , Técnicas de Cultura Celular por Lotes , Biodegradação Ambiental , Modelos Químicos , Tamanho da Partícula , Esgotos/microbiologia , Solubilidade
5.
J Hazard Mater ; 183(1-3): 389-94, 2010 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-20691538

RESUMO

The main objective of this work was to study the effectiveness of iron oxide-coated pumice and volcanic slag particles in removing disinfection by-product (DBP) precursors from a raw drinking water source with high specific UV absorbance (SUVA(254)) value. Iron oxide coating of particles significantly increased dissolved organic carbon (DOC) uptakes and decreased DBP formation after chlorination compared to uncoated particles. pH values close to neutral levels during adsorption and chlorination provided DOC, trihalomethane and haloacetic acid reductions around 60-75% employing 6 g/L coated particle dosage. Higher degree of DOC and DBP reductions (>85%) were obtained with increasing particle dose. The uptake of bromide by iron oxide surfaces was negligible and increasing bromide concentrations (up to 550 µg/L) did not negatively impact the DOC uptake. However, due to competition between natural organic matter (NOM) and bicarbonate for the iron oxide surfaces, increasing bicarbonate alkalinity levels reduced DOC uptakes. Overall, the results indicated that the iron oxide-coated pumice/slag particles are effective adsorbents to remove NOM and control DBP formation in waters with relatively high DOC and SUVA(254) levels. However, they may not be effective for waters with alkalinity levels above 250 mg CaCO(3)/L.


Assuntos
Adsorção , Desinfetantes/isolamento & purificação , Compostos Férricos , Silicatos , Erupções Vulcânicas , Desinfecção , Raios Ultravioleta
6.
Water Sci Technol ; 62(3): 547-55, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20706002

RESUMO

The main objective of this work was to investigate the effectiveness of ceramic ultrafiltration (UF) membranes with different pore sizes in removing natural organic matter (NOM) from model solutions and drinking water sources. A lab-scale, cross-flow ceramic membrane test unit was used in all experiments. Two different single-channel tubular ceramic membrane modules were tested with average pore sizes of 4 and 10 nm. The impacts of membrane pore size and pressure on permeate flux and the removals of UV(280 nm) absorbance, specific UV absorbance (SUVA(280 nm)), and dissolved organic carbon (DOC) were determined. Prior to experiments with model solutions and raw waters, clean water flux tests were conducted. UV(280) absorbance reductions ranged between 63 and 83% for all pressures and membranes tested in the raw water. More than 90% of UV(280) absorbance reduction was consistently achieved with both membranes in the model NOM solutions. Such high UV absorbance reductions are advantageous due to the fact that UV absorbing sites of NOM are known to be one of the major precursors to disinfection by-products (DBP) such as trihalomethanes and haloacetic acids. For both UF membranes, the ranges of DOC removals in the raw water and model NOM solutions were 55-73% and 79-91%, respectively. SUVA(280) value of the raw water decreased from 2 to about 1.5 L/mg-m by both membranes. For the model solutions, SUVA(280) values were consistently reduced to < or =1 L/mg-m levels after membrane treatment. As the SUVA(280) value of the NOM source increased, the extent of SUVA(280) reduction and DOC removal by the tested ceramic UF membranes also increased. The results overall indicated that ceramic UF membranes, especially the one with 4 nm average pore size, appear to be effective in removing organic matter and DBP precursors from drinking water sources with relatively high and sustainable permeate flux values.


Assuntos
Cerâmica , Desinfetantes/química , Membranas Artificiais , Poluentes Químicos da Água/química , Purificação da Água , Fatores de Tempo , Eliminação de Resíduos Líquidos/instrumentação , Eliminação de Resíduos Líquidos/métodos , Microbiologia da Água
7.
J Hazard Mater ; 173(1-3): 137-43, 2010 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-19744786

RESUMO

The main objective of this study was to investigate the effects of reductive acidic leaching and further precipitation on the recovery of manganese and zinc from spent alkaline and zinc-carbon battery powders. Ascorbic acid (AA), citric acid (CA) and oxalic acid (OA) were tested as the reductants. Sodium hydroxide and potassium hydroxide were used as precipitating agents. OA with H(2)SO(4) or HCl was not effective on the leaching of zinc due to the formation of zinc oxalate precipitates. However, the other reducing agents (CA and AA) tested under various experimental conditions were effective in the acidic leaching of both zinc and manganese. Leaching yields of both manganese and zinc were higher at leach temperature of 90 degrees C than those at 30 degrees C. Leach solutions were purified by the selective precipitation of manganese and zinc using KOH or NaOH. Complete precipitation was obtained for Mn at pH 9-10 and for Zn at pH 7-8. The use of ascorbic acid or citric acid as reductants in acidic leaching appears to be effective in the simultaneous leaching and further recovery of zinc and manganese from spent alkaline and zinc-carbon battery powders.


Assuntos
Resíduos Industriais/análise , Manganês/análise , Poluentes Químicos da Água/análise , Zinco/análise , Ácidos/química , Análise de Variância , Ácido Ascórbico/química , Fontes de Energia Elétrica , Pós , Substâncias Redutoras , Eliminação de Resíduos , Ácidos Sulfúricos/química , Temperatura , Termodinâmica , Difração de Raios X
8.
Water Sci Technol ; 60(6): 1475-87, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19759450

RESUMO

This work evaluated artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS) modelling methods to estimate organic carbon removal using the correlation among the past information of influent and effluent parameters in a full-scale aerobic biological wastewater treatment plant. Model development focused on providing an adaptive, useful, practical and alternative methodology for modelling of organic carbon removal. For both models, measured and predicted effluent COD concentrations were strongly correlated with determination coefficients over 0.96. The errors associated with the prediction of effluent COD by the ANFIS modelling appeared to be within the error range of analytical measurements. The results overall indicated that the ANFIS modelling approach may be suitable to describe the relationship between wastewater quality parameters and may have application potential for performance prediction and control of aerobic biological processes in wastewater treatment plants.


Assuntos
Lógica Fuzzy , Eliminação de Resíduos de Serviços de Saúde/métodos , Redes Neurais de Computação , Oxigênio/química , Oxigênio/isolamento & purificação , Eliminação de Resíduos Líquidos/métodos , Tomada de Decisões , Modelos Lineares , Modelos Químicos , Análise Multivariada , Compostos Orgânicos/química , Compostos Orgânicos/isolamento & purificação , Análise de Componente Principal , Reprodutibilidade dos Testes
9.
Braz J Med Biol Res ; 42(4): 346-52, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19330262

RESUMO

The present study describes the in vitro antimicrobial and antioxidant activity of methanol and water extracts of sweet and bitter apricot (Prunus armeniaca L.) kernels. The antioxidant properties of apricot kernels were evaluated by determining radical scavenging power, lipid peroxidation inhibition activity and total phenol content measured with a DPPH test, the thiocyanate method and the Folin method, respectively. In contrast to extracts of the bitter kernels, both the water and methanol extracts of sweet kernels have antioxidant potential. The highest percent inhibition of lipid peroxidation (69%) and total phenolic content (7.9 +/- 0.2 microg/mL) were detected in the methanol extract of sweet kernels (Hasanbey) and in the water extract of the same cultivar, respectively. The antimicrobial activities of the above extracts were also tested against human pathogenic microorganisms using a disc-diffusion method, and the minimal inhibitory concentration (MIC) values of each active extract were determined. The most effective antibacterial activity was observed in the methanol and water extracts of bitter kernels and in the methanol extract of sweet kernels against the Gram-positive bacteria Staphylococcus aureus. Additionally, the methanol extracts of the bitter kernels were very potent against the Gram-negative bacteria Escherichia coli (0.312 mg/mL MIC value). Significant anti-candida activity was also observed with the methanol extract of bitter apricot kernels against Candida albicans, consisting of a 14 mm in diameter of inhibition zone and a 0.625 mg/mL MIC value.


Assuntos
Antibacterianos/farmacologia , Antioxidantes/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Extratos Vegetais/farmacologia , Prunus/química , Antibacterianos/isolamento & purificação , Antioxidantes/isolamento & purificação , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos
10.
J. venom. anim. toxins incl. trop. dis ; 15(1): 146-156, 2009. ilus
Artigo em Inglês | LILACS, VETINDEX | ID: lil-508240

RESUMO

The wolf spider Lycosa singoriensis (Laxmann, 1770) (Lycosidae: Araneae) is distributed throughout central and eastern Europe, including Russia, Kazakhistan and Turkey. This study describes the venom apparatus morphology of L. singoriensis through scanning electron microscopy (SEM). Its structure follows the general architecture observed in other spiders. Generally, a venom apparatus is composed by a pair of venom glands and chelicerae. L. singoriensis chelicerae are robust and consist of a stout basis and a movable apical segment (fang). The fang rests in a groove on the basal segment that is covered by different types of hair. L. singoriensis venom glands present equal size and measure about 4 mm in length. Each gland is enclosed by irregular muscular layers.(AU)


Assuntos
Animais , Venenos de Aranha/análise , Aranhas , Pesos e Medidas
11.
J Int Med Res ; 36(6): 1378-82, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19094449

RESUMO

The coagulase activities of various Candida spp were assessed using a classical tube test. A total of 125 clinical Candida isolates representing eight species (C. albicans, C. parapsilosis, C. tropicalis, C. glabrata, C. kefyr, Geotrichum candidum, C. krusei and C. guilliermondii) were incubated with rabbit, sheep or human plasma. After 24 h incubation, 29/64 (45.3%) C. albicans isolates and 23/61 (37.7%) non-albicans Candida strains were positive for coagulase in rabbit plasma, whereas 20/64 (31.2%) C. albicans and 6/61 (9.8%) non-albicans Candida isolates were positive for coagulase in sheep plasma. None of the tested Candida isolates reacted positively in human plasma. These results suggest that rabbit plasma is the most appropriate medium for detection of coagulase activity in Candida spp. Variations in coagulase production by Candida spp may be related to their pathogenicity. It is concluded that the laboratory detection of coagulase activity in clinical isolates of Candida spp may help the diagnosis of Candida-related infections.


Assuntos
Candida/enzimologia , Candida/patogenicidade , Candidíase/microbiologia , Coagulase/metabolismo , Animais , Candida/isolamento & purificação , Candidíase/diagnóstico , Coagulase/análise , Humanos , Coelhos , Ovinos , Especificidade da Espécie
12.
J. venom. anim. toxins incl. trop. dis ; 14(4): 641-650, 2008. ilus, tab
Artigo em Inglês | LILACS, VETINDEX | ID: lil-500134

RESUMO

Since the number of microorganisms that are resistant to antibiotics has been increasing steadily, the need for combating these pathogens requires new pharmaceutical agents. To produce these substances, new models have been developed in recent decades. In our study, the venom of Agelena labyrinthica (Clerck, 1757) (Araneae: Agelenidae) was tested against ten bacterial strains, specifically, testing 1/100, 1/10 and 1/1 fractions of diluted venom against these bacteria. While the 1/100 dilution was successful in only one of ten bacterial strains, the 1/10 and the 1/1 were effective on six of ten bacterial strains. The most effective results, among these three different concentrations, were observed on Bacillus subtilis. The other five strains that were also sensitive to the dilutions showed similar inhibition zones. Morphological alterations on bacterial cells and comparison with normal cells were accomplished by scanning electron microscopy (SEM). The venom-treated cells, due to their loss of cytoplasm, shrank and presented cell wall depression.(AU)


Assuntos
Animais , Aranhas , Bacillus subtilis , Citoplasma , Antibacterianos , Microscopia Eletrônica de Varredura
13.
J. venom. anim. toxins incl. trop. dis ; 14(3): 466-480, 2008. ilus
Artigo em Inglês | LILACS, VETINDEX | ID: lil-492210

RESUMO

The histology and ultrastructure of venom glands in the scorpion Euscorpius mingrelicus (Kessler, 1874) are described and illustrated in the current study for the first time by employing light microscopy and transmission electron microscopy (TEM). The venom apparatus is composed of a pair of venom glands and a stinger, both situated in the last segment of the metasoma. The venom glands are completely separate but similar. The two glands are segregated within the telson by striated muscle bundles, and their outer surfaces are surrounded by a cuticle. An internal layer constitutes the secretory epithelium. This epithelium is made up of simple columnar cells. The nucleus and organelles involved in cellular synthetic activity are situated basally. In the apical portion, near the gland lumen, there are many secretory granules of different sizes, shapes and electron densities.(AU)


Assuntos
Animais , Venenos de Escorpião/enzimologia , Escorpiões , Histologia
14.
J. venom. anim. toxins incl. trop. dis ; 14(1): 178-187, 2008. ilus
Artigo em Inglês | LILACS, VETINDEX | ID: lil-479350

RESUMO

Loxoscelism is caused by envenomation by spiders that belong to the Loxosceles genus. In loxoscelism, a local necrotic lesion appears and, in many cases, loxoscelism or necrotic araneism is considered a serious public health problem. There is no diagnostic test available to help the physician make a diagnostic or therapeutic decision. Here, we report the case of a severe dermonecrotic araneism (loxoscelism) in Turkey probably due to the bite of Loxosceles rufescens. There was little erythema at the beginning, followed by severe necrosis after 20 days, and skin grafting was needed although the case was treated.(AU)


Assuntos
Animais , Picada de Aranha , Saúde Pública , Testes Diagnósticos de Rotina , Relatório de Pesquisa
16.
Environ Technol ; 28(1): 83-93, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17283952

RESUMO

This study aimed to investigate the potential for phosphate recovery, instead of removal, from wastewater at conventional biological treatment processes. In the first part of this study, struvite and apatite phosphate-salts formation potential were investigated using artificially prepared solutions. In the second part, real municipal wastewater was subjected to batch-basis aerobic/anaerobic sequential order operation and supernatant of high phosphate-concentrations released into the liquid medium during the anaerobic phase were withdrawn and subjected to chemical precipitation tests. The formed mixed-liquor suspended solid suspensions were subjected to quiescent settling to ensure the separation of solids. Then, to form chemical bonds between calcium and phosphate ions, calcium was added to the withdrawn supernatants. The ability of apatite formation by itself as well as support-aided apatite formation was tested in supernatants. All the precipitation tests were carried out at orbital incubator at constant 20 degrees C and 25 degrees C temperature which were reported to be the range yielding the highest phosphate precipitation efficiency. In order to evaluate the solid-liquid separation ability of the chemical slurries, both centrifugation at 2000 rpm and membrane filtration at 100 mbar vacuum pressure were tested. The recovered solid phases as well as supernatants were analyzed for phosphate contents and it was revealed that the highest efficiency of phosphate precipitation was at pH of 9.50 for apatite and 9.40 for struvite. The results also suggested that struvite precipitation is more applicable for technical purposes while apatite precipitation is more applicable for economical reasons.


Assuntos
Fosfatos/química , Gerenciamento de Resíduos/métodos , Poluentes Químicos da Água/química , Apatitas/química , Precipitação Química , Compostos de Magnésio/química , Fosfatos/análise , Estruvita
17.
Chemosphere ; 66(1): 130-8, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16784768

RESUMO

Natural pumice particles were used as granular support media and coated with iron oxides to investigate their adsorptive natural organic matter (NOM) removal from waters. The impacts of natural pumice source, particle size fraction, pumice dose, pumice surface chemistry and specific surface area, and NOM source on the ultimate extent and rate of NOM removal were studied. All adsorption isotherm experiments were conducted employing the variable-dose completely mixed batch reactor bottle-point method. Iron oxide coating overwhelmed the surface electrical properties of the underlying pumice particles. Surface areas as high as 20.6m(2)g(-1) were achieved after iron coating of pumice samples, which are above than those of iron coated sand samples reported in the literature. For all particle size fractions, iron coating of natural pumices significantly increased their NOM uptakes both on an adsorbent mass- and surface area-basis. The smallest size fractions (<63 microm) of coated pumices generally exhibited the highest NOM uptakes. A strong linear correlation between the iron contents of coated pumices and their Freundlich affinity parameters (K(F)) indicated that the enhanced NOM uptake is due to iron oxides bound on pumice surfaces. Iron oxide coated pumice surfaces preferentially removed high UV-absorbing fractions of NOM, with UV absorbance reductions up to 90%. Control experiments indicated that iron oxide species bound on pumice surfaces are stable, and potential iron release to the solution is not a concern at pH values of typical natural waters. Based on high NOM adsorption capacities, iron oxide coated pumice may be a promising novel adsorbent in removing NOM from waters. Furthermore, due to preferential removal of high UV-absorbing NOM fractions, iron oxide coated pumice may also be effective in controlling the formation of disinfection by-products in drinking water treatment.


Assuntos
Ferro/química , Compostos Orgânicos/química , Silicatos/química , Adsorção , Microscopia Eletrônica de Varredura , Compostos Orgânicos/isolamento & purificação , Tamanho da Partícula , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos
18.
AJNR Am J Neuroradiol ; 27(3): 593-5, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16551999

RESUMO

Inferior vena cava (IVC) agenesis is a rare anomaly that is usually an incidental finding in radiologic work-up or it can rarely be symptomatic due to deep venous thrombosis of iliac veins. In this report, we present a case of IVC agenesis detected on lumbar spinal MR imaging scans by extensive epidural-paravertebral collateral vessels compressing the thecal sac and causing low back pain in a child.


Assuntos
Dor Lombar/etiologia , Imageamento por Ressonância Magnética , Veia Cava Inferior/anormalidades , Veia Cava Inferior/patologia , Adolescente , Feminino , Humanos
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