排序方式: 共有29条查询结果,搜索用时 15 毫秒
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Rosane Bassi Soares Denis Honorato Costa Walter Miyakawa Maria Goretti Temoteo Delgado Aguinaldo Silva Garcez Tania Mateus Yoshimura Martha Simões Ribeiro Silvia Cristina Nunez 《Photochemistry and photobiology》2020,96(3):618-624
Ventilator-associated pneumonia (VAP) is an infection that arises after endotracheal intubation affecting patients under intensive care. The presence of the endotracheal tube (ETT) is a risk factor since it is colonized by multispecies biofilm. Antimicrobial photodynamic therapy (aPDT) could be a strategy to decontaminate ETTs. We verify if methylene blue (MB) associated with external illumination of the ETT could be an alternative to destroy biofilm. We performed an in vitro and ex vivo study. In vitro study was performed with P. aeruginosa biofilm grew over ETT for 7 days. After treatment, the surviving cells were cultured for 3 days and the biofilm was analyzed by crystal violet absorbance. Ex vivo study employed ETT obtained from extubated patients. aPDT was performed with MB (100 µm ) and red LED (λ = 640±20 nm). We quantified the biofilm thickness and used scanning electron microscopy and fluorescence technique to verify morphological and functional changes after aPDT. Our results showed that bacteria remain susceptible to aPDT after sequential treatments. We also attested that aPDT can reduce biofilm thickness, disrupt biofilm attachment from ETT surface and kill microbial cells. These data suggest that aPDT should be investigated to decrease VAP incidence via ETT decontamination. 相似文献
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Pereira CF Pimentel MF Galvão RK Honorato FA Stragevitch L Martins MN 《Analytica chimica acta》2008,611(1):41-47
This work presents a comparative study of calibration transfer among three near infrared spectrometers for determination of naphthenes and RON (Research Octane Number) in gasoline. Seven transfer methods are compared: direct standardization (DS), piecewise direct standardization (PDS), orthogonal signal correction (OSC), reverse standardization (RS), piecewise reverse standardization (PRS), slope and bias correction (SBC) and model updating (MU). Two pre-treatment procedures, namely standard normal variate (SNV) and multiplicative scatter correction (MSC), are also investigated. The choice of an appropriate number of transfer samples for each technique, as well as the effect of window size in PDS/PRS and OSC components, are discussed. A broad set of gasoline samples representative of the Northeastern states of Brazil is employed in the investigation. The results show that the use of calibration transfer yields prediction errors comparable to those obtained with complete recalibration of the secondary instrument. Overall, the results point to RS as the best method for the analytical problem under consideration. When storage and/or physical transportation of transfer samples are impractical, MU is more appropriate. The comprehensive investigation carried out in the present work will be of value for practitioners involved in networks of fuel monitoring. 相似文献
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A flow-batch system allowing in-line individual sample matrix matching is proposed for analysis of sample lots with high variability in acidity. The feasibility of the approach is demonstrated in the spectrophotometric determination of total nitrogen in Kjeldahl digests, using a column with a slightly soluble reagent (AgCl). The solutions are sequentially injected by means of an 8-port selecting valve and processed in a mixing chamber that is also used as a monitoring unit. The system yields reproducible results (r.s.d. usually < 2.5%) and the sampling rate is 14 samples/h. The analytical curve is linear within 1.00 and 6.00% N (dry basis), and the regression coefficient is > 0.999 (n = 6). Results are in agreement with certified values of standard reference materials and with results obtained by conductometry. 相似文献
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J. M. T. Carneiro R. S. Honorato E. A. G. Zagatto 《Analytical and bioanalytical chemistry》2000,368(5):496-500
A flow-batch system allowing in-line individual sample matrix matching is proposed for analysis of sample lots with high
variability in acidity. The feasibility of the approach is demonstrated in the spectrophotometric determination of total nitrogen
in Kjeldahl digests, using a column with a slightly soluble reagent (AgCl). The solutions are sequentially injected by means
of an 8-port selecting valve and processed in a mixing chamber that is also used as a monitoring unit. The system yields reproducible
results (r.s.d. usually < 2.5%) and the sampling rate is 14 samples/h. The analytical curve is linear within 1.00 and 6.00%
N (dry basis), and the regression coefficient is > 0.999 (n = 6). Results are in agreement with certified values of standard
reference materials and with results obtained by conductometry.
Received: 5 April 2000 / Revised: 6 June 2000 / Accepted: 13 June 2000 相似文献
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Andressa H. de Morais Batista Francisco F. de Sousa Sara B. Honorato Alejandro P. Ayala Josue M. Filho Francisco W. de Sousa Antonio N. Pinheiro J.C.S. de Araujo Ronaldo F. Nascimento Antoninho Valentini Alcineia C. Oliveira 《Journal of molecular catalysis. A, Chemical》2010,315(1):86-98
Isomorphously substituted (MeDM) and impregnated metal-containing MCM-41 (MeOx/IM) catalysts, in which Me = Co, Cu, Cr, Fe or Ni, have been prepared. Structural and textural characterizations of the catalysts were performed by means of X-ray diffraction (XRD), chemical analysis, Raman spectroscopy, electron paramagnetic resonance (EPR), N2 adsorption isotherms and temperature programmed reduction (TPR). Cu2+, Co2+, and Cr4+/Cr3+ species were found over the catalysts as cations incorporated in the MCM-41 structure (MeDM) or highly dispersed oxides on the surface (MeOx/IM). The MeDM catalysts exhibited a good performance in the dehydrogenation of ethylbenzene with CO2. However, MeOx/IM catalysts had a low performance in styrene production (activity less than 15 × 10?3 mmol h?1 and selectivity for styrene less than 80%) due to the high reducibility of the metals species. However, Ni2+ or Fe3+ coordinated with the MCM-41 framework, as well as NiOx and Fe2O3 extra-framework species, is continuously oxidized by the CO2 to maintain the active sites for dehydrogenating ethylbenzene. Deactivation studies on the FeDM sample showed that Fe3+ species produced active sp2 carbon compounds, which are removed by CO2; the referred sample is catalytically selective for styrene and stable over 24 h of reaction. In contrast, highly active Ni2+ and Ni0 species produced a large amount of polyaromatic carbonaceous deposits from styrene, as identified by TPO, TG and Raman spectroscopy. An acid–base mechanism is proposed to operate to adsorb ethylbenzene and abstract the β-hydrogen. CO2 plays a role in furnishing the lattice oxygen to maintain the Fe3+ active sites in the dehydrogenation of ethylbenzene to form styrene. 相似文献
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Laíse Oliveira Resende Ana Cristina Honorato de Castro Adriano O. Andrade João Marcos Madurro Ana Graci Brito-Madurro 《Journal of Solid State Electrochemistry》2018,22(5):1365-1372
Epidemiological studies have demonstrated an association between the risk of cardiovascular events and increasing C-reactive protein (CRP) concentration. This paper reports the development of an immunosensor for the assessment of the cardiovascular process using anti-C-reactive protein antibody immobilized onto a gold-printed screen electrode. Positive and negative human sera were successfully evaluated using electrochemical impedance spectroscopy (EIS), differential pulse voltammetry (DPV), and atomic force microscopy (AFM). EIS results show that, after the incubation with positive serum for myocardial infarction, the resistance increased about two times in relation to the negative serum. A linear range from 6.25 to 50 μg mL?1 and detection limit of 0.78 μg mL?1 using DPV were obtained. The immunosensor developed for the CRP detection using gold electrode revealed efficacy and a potential use for the diagnosis and monitoring of the progression of cardiovascular diseases. 相似文献
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Laís Peres Silva Ivanilson Pimenta Santos Dahara Keyse Carvalho Silva Bruna Padilha Zurita Claro dos Reis Cssio Santana Meira Marcos Venícius Batista de Souza Castro Jos Maurício dos Santos Filho Joo Honorato de Araujo-Neto Javier Alcides Ellena Rafael Gomes da Silveira Milena Botelho Pereira Soares 《Molecules (Basel, Switzerland)》2022,27(23)
Immunomodulatory agents are widely used for the treatment of immune-mediated diseases, but the range of side effects of the available drugs makes necessary the search for new immunomodulatory drugs. Here, we investigated the immunomodulatory activity of new ferrocenyl-N-acyl hydrazones derivatives (SintMed(141–156). The evaluated N-acyl hydrazones did not show cytotoxicity at the tested concentrations, presenting CC50 values greater than 50 µM. In addition, all ferrocenyl-N-acyl hydrazones modulated nitrite production in immortalized macrophages, showing inhibition values between 14.4% and 74.2%. By presenting a better activity profile, the ferrocenyl-N-acyl hydrazones SintMed149 and SintMed150 also had their cytotoxicity and anti-inflammatory effect evaluated in cultures of peritoneal macrophages. The molecules were not cytotoxic at any of the concentrations tested in peritoneal macrophages and were able to significantly reduce (p < 0.05) the production of nitrite, TNF-α, and IL-1β. Interestingly, both molecules significantly reduced the production of IL-2 and IFN-γ in cultured splenocytes activated with concanavalin A. Moreover, SintMed150 did not show signs of acute toxicity in animals treated with 50 or 100 mg/kg. Finally, we observed that ferrocenyl-N-acyl hydrazone SintMed150 at 100 mg/kg reduced the migration of neutrophils (44.6%) in an acute peritonitis model and increased animal survival by 20% in an LPS-induced endotoxic shock model. These findings suggest that such compounds have therapeutic potential to be used to treat diseases of inflammatory origin. 相似文献
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Gislaine Aparecida Honorato Ricardo Vieira de Lima Bhaskar Reddy Manda Derisvaldo Rosa Paiva Tairine Pimentel Roberto da Silva Gomes 《Tetrahedron letters》2017,58(23):2240-2243
The comparison in several reaction conditions for synthesis of nonracemic α-methylsulfinylation of 3,4-dihydronaphthalen-1(2H)-one was achieved. The sulfanylation reactions of 3,4-dihydronaphthalen-1(2H)-one-O-methyloxime and 2-(methylsulfinyl)-3,4-dihydronaphthalen-1(2H)-one-O-methyloxime by homogenous reaction medium are reported. The products were obtained in good yields and de. The yields, diastereoselectivity and theoretical calculations to all obtained compounds to support the experimental data are compared and discussed. 相似文献