Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
Environ Sci Pollut Res Int ; 30(34): 82795-82806, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37336851

RESUMO

The Brazil nut shell was used as a precursor material for preparing activated carbon by chemical activation with potassium hydroxide. The obtained material (BNSAC) was characterized, and the adsorptive features of phenol were investigated. The characterization showed that the activated carbon presented several rounded cavities along the surface, with a specific surface area of 332 m2 g-1. Concerning phenol adsorption, it was favored using an adsorbent dosage of 0.75 g L-1 and pH 6. The kinetic investigation revealed that the system approached the equilibrium in around 180 min, and the Elovich model represented the kinetic curves. The Sips model well represented the equilibrium isotherms. In addition, the increase in temperature from 25 to 55 °C favored the phenol adsorption, increasing the maximum adsorption capacity value (qs) from 83 to 99 mg g-1. According to the estimated thermodynamic parameters, the adsorption was spontaneous, favorable, endothermic, and governed by physical interactions. Therefore, the Brazil nut shell proved a good precursor material for preparing efficient activated carbon for phenol removal.


Assuntos
Bertholletia , Poluentes Químicos da Água , Fenol/química , Carvão Vegetal/química , Concentração de Íons de Hidrogênio , Fenóis , Termodinâmica , Adsorção , Água , Cinética , Poluentes Químicos da Água/análise , Soluções
2.
Environ Sci Pollut Res Int ; 29(51): 77698-77710, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35680753

RESUMO

Removal of phenol from wastewater is essential to achieve permitted concentrations according to the recommendations of USEPA. The adsorption capacity of phenol in activated adsorbent with KOH of Enterolobium contortisiliquum (TAC) was evaluated at different temperatures. The Langmuir isotherm represented the equilibrium data of this study. Thermodynamic process was endothermic, spontaneous, and reversible. The mass transfer parameters ranged from KE 0.68 to 0.96 × 10-3 (cm s-1), Ds 8.95 to 14.35 × 10-9 (cm2 s-1), and Dp 5.023 × 10-8 (cm2 s-1). The PVSDM model represented the adsorption kinetics. Intraparticle diffusion limits the mass transfer process Biot > 100. The two-stage process minimized the total amount of TAC required to achieve the permitted specification of phenol concentration in wastewater from different industrial sectors. TAC showed significant performance in the removal of phenol from wastewater.


Assuntos
Fenol , Poluentes Químicos da Água , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Fenóis , Termodinâmica , Águas Residuárias
3.
J Fungi (Basel) ; 4(2)2018 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-29882883

RESUMO

Sporotrichosis is a cosmopolitan, chronic granulomatous mycosis, acquired by traumatic inoculation and caused by Sporothrix schenckii complex. Several methods of diagnostic are available, from KOH to molecular biology. In this review, we describe from the simplest (clinical diagnosis) to the most advanced diagnostic techniques (molecular biology).

4.
CES med ; 32(1): 41-52, ene.-abr. 2018. graf
Artigo em Espanhol | LILACS | ID: biblio-974532

RESUMO

Resumen El diagnóstico de las micosis constituye un problema clínico y terapéutico de interés actual debido al incremento y gravedad de las infecciones diseminadas. Por esta razón, en los últimos años se ha priorizado la búsqueda de nuevos métodos para el diagnóstico rápido y preciso. En la actualidad contamos con métodos tradicionales como KOH, cultivo, histopatología y serología, y, de forma más reciente, con métodos moleculares que permiten mayor rapidez y sensibilidad. En esta revisión se hace énfasis en la importancia de los métodos de diagnóstico micológico para la dermatología y la medicina general, ya que debido al desconocimiento en este campo, la preparación del paciente no es la adecuada y, por otro lado, la dificultad en la interpretación de los resultados lleva a confusión y tratamientos incorrectos.


Abstract Diagnosis of fungal infections is a clinical and therapeutic problem of current interest due to the increase and severity of disseminated infections. For this reason in recent years have been mainly seeking new methods for fast and accurate diagnosis. At present we have traditional methods like KOH, culture, histopathology and serology, and more recently molecular methods that allow greater speed and sensitivity in diagnosis. This review emphasizes the importance of mycological diagnosis methods for dermatology and general medicine, as due to ignorance in this field, patient preparation is not adequate and secondly the difficulty in interpreting results and treatment choice are misleading.

5.
An. acad. bras. ciênc ; 89(3): 1629-1633, July-Sept. 2017. graf
Artigo em Inglês | LILACS | ID: biblio-886770

RESUMO

ABSTRACT Genitalia are rich source of characters in insect taxonomy. Usually, they are examined after dissection and cleaning with potassium hydroxide (KOH), procedure that may damage both genital morphological structures and intracellular molecular contents. Enzymatic procedure with Proteinase K has been used to clean muscle off the genitalia while extract DNA, but its damage to the genital structures has not been evaluated. Herein, we qualitatively compare the use of KOH and Proteinase K to prepare genital structures in minute insects (Hymenoptera: Bethylidae). We show that Proteinase K is better to preserve the genital structure and provides quality DNA.


Assuntos
Animais , Masculino , Vespas/anatomia & histologia , DNA/isolamento & purificação , Endopeptidase K/administração & dosagem , Genitália/anatomia & histologia , Vespas/classificação , Vespas/genética
6.
Neurol Res ; 39(7): 649-659, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28398193

RESUMO

OBJECTIVE: Scopolamine (SCO) administration to rats induces molecular features of AD and other dementias, including impaired cognition, increased oxidative stress, and imbalanced cholinergic transmission. Although mitochondrial dysfunction is involved in different types of dementias, its role in cognitive impairment induced by SCO has not been well elucidated. The aim of this work was to evaluate the in vivo effect of SCO on different brain mitochondrial parameters in rats to explore its neurotoxic mechanisms of action. METHODS: Saline (Control) or SCO (1 mg/kg) was administered intraperitoneally 30 min prior to neurobehavioral and biochemical evaluations. Novel object recognition and Y-maze paradigms were used to evaluate the impact on memory, while redox profiles in different brain regions and the acetylcholinesterase (AChE) activity of the whole brain were assessed to elucidate the amnesic mechanism of SCO. Finally, the effects of SCO on brain mitochondria were evaluated both ex vivo and in vitro, the latter to determine whether SCO could directly interfere with mitochondrial function. RESULTS: SCO administration induced memory deficit, increased oxidative stress, and increased AChE activities in the hippocampus and prefrontal cortex. Isolated brain mitochondria from rats administered with SCO were more vulnerable to mitochondrial swelling, membrane potential dissipation, H2O2 generation and calcium efflux, all likely resulting from oxidative damage. The in vitro mitochondrial assays suggest that SCO did not affect the organelle function directly. CONCLUSION: In conclusion, the present results indicate that SCO induced cognitive dysfunction and oxidative stress may involve brain mitochondrial impairment, an important target for new neuroprotective compounds against AD and other dementias.


Assuntos
Transtornos da Memória/metabolismo , Mitocôndrias/metabolismo , Acetilcolinesterase/metabolismo , Animais , Encéfalo/metabolismo , Cálcio/metabolismo , Cátions Bivalentes/metabolismo , Modelos Animais de Doenças , Peróxido de Hidrogênio/metabolismo , Masculino , Aprendizagem em Labirinto/fisiologia , Potencial da Membrana Mitocondrial/fisiologia , Dilatação Mitocondrial/fisiologia , Estresse Oxidativo/fisiologia , Distribuição Aleatória , Ratos Wistar , Reconhecimento Psicológico/fisiologia , Escopolamina
7.
Dermatol Pract Concept ; 5(2): 39-44, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26114050

RESUMO

BACKGROUND: Onychomycosis is the most common nail disease, representing 50% of cases affecting the nail apparatus. The diagnosis is made by clinical examination along with the KOH exam of the nail and culture of the sample. However, not all dermatologists have access to a mycology lab. OBJECTIVE: To determine the correlation between KOH examination and dermoscopic patterns in patients with clinical diagnosis of onychomycosis. PATIENTS/METHODS: A descriptive, open, observational, prospective, cross-sectional study of 178 patients with clinical suspicion of onychomycosis was conducted. All patients underwent clinical examination, dermoscopy with a DermLite PHOTO dermatoscope (3Gen, San Juan Capistrano, CA, USA), KOH assessment and culture analysis. The most frequent dermoscopic patterns were identified and their correlation with the clinical subtype of onychomycosis was analyzed. RESULTS: The study included 178 patients with clinical suspicion of onychomycosis. Of these, 155 (87.1%) had positive direct KOH examination for onychomycosis. Eighty-seven patients (56.13%) presented with clinical onychomycosis pattern of total dystrophic onychomycosis (TDO), 67 (43.23%) with distal lateral subungual onychomycosis (DLSO), 1 (0.65%) with trachyonychia). Dermoscopic patterns of onychomycosis showed the following frequencies: the spiked pattern was present in 22 patients (14.19%), longitudinal striae pattern in 51 patients (32.9%) and linear edge pattern in 21 patients (13.55%). We identified a pattern described as "distal irregular termination" in 41 patients with TDO and 26 with DLSO. CONCLUSIONS: This is the fist study conducted in a Mexican population that uses dermoscopy as a diagnostic tool along with the KOH examination for the diagnosis of onychomycosis. Dermoscopy may be used as an important diagnostic tool when evaluating nail disease. However, it should not be used as the only diagnostic criteria for onychomycosis.

8.
Rev. bras. anal. clin ; 28(2): 55-57, 1996. tab, ilus
Artigo em Português | LILACS | ID: lil-534696

RESUMO

Cinco métodos para coloração de Gram foram comparados. O melhor resultado foi obtido com o método descrito em Lennette et al., 1974. A técnica da lise pelo KOH 3% foi comparada com a coloração de Gram em 164 cepas bacterianas. A técnica apresentou resultados compatíveis com os obtidos no método de Gram para todas as bactérias analisadas.


Assuntos
Técnicas de Laboratório Clínico , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Coloração e Rotulagem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA