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1.
Using dynamic data exchange to exchange information between Visual Basic and Matlab : Application to a diode array spectrophotometer 总被引:1,自引:0,他引:1
Photodiode array spectrometers are increasingly being coupled to flow analysis and separation techniques. Computer programs are needed to control the data acquisition from each photodiode and to handle the data. The Microsoft Visual Basic programming language is used along with a DLL library and dynamic data exchange (DDE) to allow communication with the MATLAB computational environment. 相似文献
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Andrea Paesano Jr. Alexandre Christófaro Silva Flávio Francisco Ivashita Carla Fabiana Cerqueira Machado-Flavio Sives Flávio Sives Roberto Carlos Mercader José Domingos Fabris 《Hyperfine Interactions》2014,226(1-3):585-592
A peatland in Pinheiro, Diamantina City, Minas Gerais State - Brazil, was sampled at different depths of two profiles with diverse vegetation coverings (grassland field and bush) in order to collect materials that might reflect changes in the chemical states of iron over the peat formation coming from original minerals such as hematitic phyllite surrounding the boggy pedon. Samples collected were chemically, structurally and magnetically characterized. The results show that both series of peats are composed of organic matter and minerals such as quartz, kaolinite, gibbsite, rutile and muscovite. Deeper layers present only quartz. Mössbauer spectroscopy shows that iron is present in both electron states, Fe2+ and Fe3+, under both vegetations, each valence appearing in the spectra in the form of a discrete doublet. No hyperfine magnetic splitting was observed in any spectrum at room temperature. The Mössbauer subspectral area of Fe2+ tended to increase from the upper to deeper layers. Magnetic measurements reveal that the magnetic response of the surface samples is the highest, displaying a sharp decrease below 15 cm and that the magnetic signal is a superposition of (super)paramagnetic and ferrimagnetic contributions. Samples from the grassland field also show a diamagnetic component for the deeper layers. 相似文献
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Marthyna P. Souza Miguel A. Cerqueira Bartolomeu W. S. Souza José A. Teixeira Ana L. F. Porto António A. Vicente Maria G. Carneiro-da-Cunha 《Chemical Papers》2010,64(4):475-481
Policaju-based coatings were applied on “Tommy Atkins” mangoes and the effects of four different treatments on mango shelf-life
were evaluated under storage condition at 4°C and 82 % of relative humidity over 28 days. The surface tension of mangoes was
found to be 29.04 mN m−1; the dispersive and polar components were 27.57 mN m−1 and 1.47 mN m−1, respectively, and the critical surface tension was 22.7 mN m−1. A significantly lower mass loss was observed in all mangoes treated with Policaju-based coatings. For all applied treatments,
no significant variation in the total soluble solids and pH was detected over the experimental storage time. The results show
that Policaju-based coatings have a positive effect on the shelf-life extension of mangoes at low storage temperatures (4°C). 相似文献
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Oliveira EF Cerqueira NM Fernandes PA Ramos MJ 《Journal of the American Chemical Society》2011,133(39):15496-15505
In this paper we studied the mechanism of formation of the internal aldimine, a common intermediate to most pyridoxal 5'-phosphate (PLP)-dependent enzymes. A large model based on the crystal structure from the human ornithine decarboxylase (ODC) enzyme was constructed and in total accounts for 504 atoms. The reaction mechanism was investigated using the ONIOM methodology (B3LYP/6-31G(d)//AM1), and the final energies were calculated with the M06/6-311++G(2d,2p)//B3LYP/6-31G(d) level of theory. It was demonstrated that the reaction is accomplished in three sequential steps: (i) the nucleophilic attack of Lysine69 to PLP, (ii) the carbinolamine formation, and (iii) a final dehydration step. For the carbinolamine formation, several mechanistic hypotheses were explored, and the preferred pathway assigns a key role for the conserved active site Cys360. The overall reaction is exergonic in -9.1 kcal/mol, and the rate-limiting step is the dehydration step (E(a) = 13.5 kcal/mol). For the first time, we provide an atomistic portrait of this mechanism in an enzymatic environment. Moreover, we were able to assign a novel role to Cys360 in the ODC reaction mechanism that was never proposed. 相似文献
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Guimes Rodrigues Filho Júlia G. Vieira Daniel A. Cerqueira Sidney J.L. Ribeiro 《Polymer Degradation and Stability》2007,92(2):205-210
In the present work, methylcellulose produced from sugar cane bagasse was characterized by FTIR, WAXD, DTA and TGA techniques. Two samples were synthesized: methylcellulose A and methylcellulose B. The only difference in the process was the addition of fresh reactants during the preparation of methylcellulose B. The ratio between the absorption intensities of the C-H stretching band at around 2900 cm−1 and O-H stretching at around 3400 cm−1 for methylcellulose B is higher than for methylcellulose A, indicating that methylcellulose B showed an increase in the degree of substitution (DS). Methylcellulose A presents a more heterogeneous structure, which is similar to the original cellulose as seen through FTIR and DTA. Methylcellulose B showed thermal properties similar to commercial methylcellulose. The modification of methylcellulose preparation method allows the production of a material with higher DS, crystallinity and thermal stability in relation to the original cellulose and to methylcellulose A. 相似文献
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Marta Lima Rita Teixeira-Santos Luciana C. Gomes Sara I. Faria Jesus Valcarcel Jos Antonio Vzquez Miguel A. Cerqueira Lorenzo Pastrana Ana I. Bourbon Filipe J. Mergulho 《Molecules (Basel, Switzerland)》2021,26(14)
Implantable medical devices (IMDs) are susceptible to microbial adhesion and biofilm formation, which lead to several clinical complications, including the occurrence of implant-associated infections. Polylactic acid (PLA) and its composites are currently used for the construction of IMDs. In addition, chitosan (CS) is a natural polymer that has been widely used in the medical field due to its antimicrobial and antibiofilm properties, which can be dependent on molecular weight (Mw). The present study aims to evaluate the performance of CS-based surfaces of different Mw to inhibit bacterial biofilm formation. For this purpose, CS-based surfaces were produced by dip-coating and the presence of CS and its derivatives onto PLA films, as well surface homogeneity were confirmed by contact angle measurements, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The antimicrobial activity of the functionalized surfaces was evaluated against single- and dual-species biofilms of Staphylococcus aureus and Pseudomonas aeruginosa. Chitosan-based surfaces were able to inhibit the development of single- and dual-species biofilms by reducing the number of total, viable, culturable, and viable but nonculturable cells up to 79%, 90%, 81%, and 96%, respectively, being their activity dependent on chitosan Mw. The effect of CS-based surfaces on the inhibition of biofilm formation was corroborated by biofilm structure analysis using confocal laser scanning microscopy (CLSM), which revealed a decrease in the biovolume and thickness of the biofilm formed on CS-based surfaces compared to PLA. Overall, these results support the potential of low Mw CS for coating polymeric devices such as IMDs where the two bacteria tested are common colonizers and reduce their biofilm formation. 相似文献
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Cerqueira Lucas S. Vieira Alex B. Vieira Luiz F. M. Vieira Marcos A. M. Nacif José A. M. 《Wireless Networks》2021,27(3):1941-1963
Wireless Networks - The novel Underwater Wireless Sensor Network (UWSN) can contribute to monitor and explore aquatic environments. But, communicating in these environments is still hard and has... 相似文献
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Arlindo Csar Matias Pereira Helison de Oliveira Carvalho Danna Emanuelle Santos Gonalves Karyny Roberta Tavares Picano Abraho Victor Tavares de Lima Teixeira dos Santos Heitor Ribeiro da Silva Francinaldo Sarges Braga Roberto Messias Bezerra Alessandro de Sousa Nunes Maira Tiyomi Sacata Tongo Nazima Júlia Gomes Cerqueira Talisson Taglialegna Janayra Maris Teixeira Jos Carlos Tavares Carvalho 《Molecules (Basel, Switzerland)》2021,26(16)
This study aimed to evaluate and compare the effects of co-treatment with purified annatto oil (PAO) or its granules (GRA, Chronic®) with that of testosterone on the orchiectomy-induced osteoporosis in Wistar rats. After surgery, rats were treated from day 7 until day 45 with testosterone only (TES, 7 mg/kg, IM) or TES + PAO or GRA (200 mg/kg, p.o.). The following parameters were evaluated: food/water intake, weight, HDL, LDL, glucose, triglycerides (TG), total cholesterol (TC), alkaline phosphatase levels, blood phosphorus and calcium contents, femur weight, structure (through scanning electron microscopy), and calcium content (through atomic absorption spectrophotometry). Our results show that orchiectomy could significantly change the blood lipid profile and decrease bone integrity parameters. Testosterone reposition alone could improve some endpoints, including LDL, TC, bone weight, and bone calcium concentration. However, other parameters were not significantly improved. Co-treatment with PAO or GRA improved the blood lipid profile and bone integrity more significantly and improved some endpoints not affected by testosterone reposition alone (such as TG levels and trabeculae sizes). The results suggest that co-treatment with annatto products improved the blood lipid profile and the anti-osteoporosis effects of testosterone. Overall, GRA had better results than PAO. 相似文献