Considering the need for knowing the amount of biodiesel in fuels, in order to attend several leg... more Considering the need for knowing the amount of biodiesel in fuels, in order to attend several legislations around the world, this work aimed to develop a new, rapid, and nondestructive time-domain nuclear magnetic resonance (TD-NMR)based method for the biodiesel content determination in diesel−biodiesel blends. Main findings have revealed that both the transverse relaxation time (T 2) and signal areas from relaxation spectra are highly correlated to biodiesel content in the fuel samples. The highest correlation was reached by applying PLS multivariate regression over T 2 decay curve profiles. Therefore, both univariate and multivariate approaches were able to determine biodiesel content in diesel−biodiesel blends with high accuracy directly from fuel samples in a simple, fast, and inexpensive way.
The strong effect of magnetic field on the electrochemical (EC) reduction of a diamagnetic specie... more The strong effect of magnetic field on the electrochemical (EC) reduction of a diamagnetic species was monitored in situ in a 600 MHz (14 T) NMR spectrometer. Throughout EC-NMR experiments, the diamagnetic species is influenced by the Lorentz force (cross product of current density and magnetic field), which in turn acts on analyte transport and, as a result, enhances reaction rates. This phenomenon, known as magnetoelectrolysis, has not been considered in several in situ EC-NMR studies in solution, electron paramagnetic resonance (EC-EPR) spectroscopy, and magnetic resonance imaging (EC-MRI) involving the oxidation and reduction of organic compounds and lithium ion batteries. Recently, we have demonstrated the presence of this effect in the electroplating of a paramagnetic ion species by monitoring it in situ in a low-field (0.23 T) NMR spectrometer. In this report, a ca. five-fold enhancement in the electroreduction rate of benzoquinone was observed when the analyses were performe...
The aim of this paper was to present a simple and fast way of simulating Nuclear Magnetic Resonan... more The aim of this paper was to present a simple and fast way of simulating Nuclear Magnetic Resonance signals using the Bloch equations. These phenomenological equations describe the classical behavior of macroscopic magnetization and are easily simulated using rotation matrices. Many NMR pulse sequences can be simulated with this formalism, allowing a quantitative description of the influence of many experimental parameters. Finally, the paper presents simulations of conventional sequences such as Single Pulse, Inversion Recovery, Spin Echo and CPMG.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
The present study explored changes in the meat metabolome of animals subjected to different finis... more The present study explored changes in the meat metabolome of animals subjected to different finishing systems and growth rates. Thirty-six Angus × Nellore crossbred steers were used in a completely randomized design with four treatments: (1) feedlot system with high average daily gain (ADG; FH); (2) feedlot system with low ADG (FL); (3) pasture system with high ADG (PH); and (4) pasture system with low ADG (PL). After harvest and chilling, Longissimus thoracis (LT) muscle samples were taken for metabolite profile analysis using nuclear magnetic resonance. Spectrum was analyzed using chenomx software, and multi- and mega-variate data analyses were performed. The PLS-DA showed clear separation between FH and PL groups and overlap among treatments with different finishing systems but similar for matching ADG (FL and PH) treatments. Using a VIP cut-off of around 1.0, ATP and fumarate were shown to be greater in meat from PL cattle, while succinate, leucine, AMP, glutamate, carnosine, in...
Cariniana estrellensis (Raddi) Kuntze seedlings have been used in forest restoration programs in ... more Cariniana estrellensis (Raddi) Kuntze seedlings have been used in forest restoration programs in the Atlantic Forest biome. However, despite the economic and ecological relevance of this species, to date no general method for rapid identification of primary and secondary metabolites of C. estrellensis leaves has been reported. In this work, we explore the feasibility of using rapid analysis by nuclear magnetic resonance techniques and liquid chromatography coupled to diode array, charged aerosol, and mass detection. The main secondary metabolites identified were hydrolysable tannins, quinic acid, hydroxycinnamic acids (trans-p-coumaric acid, cis-p-coumaric acid, and trans-ferulic acid), and flavonoids (kaempferol and quercetin derivatives). These compounds are particularly useful as chemotaxonomic markers for the genus Cariniana and for the family Lecythidaceae, and may also be important for pharmacological uses and for the survival of the seedlings in reforestation programs.
Low field time-domain nuclear magnetic resonance (TD-NMR) relaxometry of paramagnetic metal catio... more Low field time-domain nuclear magnetic resonance (TD-NMR) relaxometry of paramagnetic metal cations (PMC) has been widely used to study and improve contrast agents for magnetic resonance imaging (MRI). However, despite its remarkable potential, TD-NMR is rarely used to study PMC complexes, and coordination compounds in non-biomedical application. Therefore, this review aimed to provide comprehensive information not only to non-nuclear magnetic resonance (NMR) relaxation specialists, but also to scientists from distinct levels and expertise, as a way to pave the path for modern analytical and research of PMC complexes. Some fundamental concepts about NMR, paramagnetic relaxation mechanism, as well as traditional and modern methods to measure the longitudinal (T1) and transverse (T2) relaxation times constants are addressed. Here, we address some applications in analytical, electrochemical, and inorganic chemistry, electrodeposition reactions, as well as studies on PMC complexes and c...
Time domain nuclear magnetic resonance (TD–NMR) has been widely applied in plant science in the l... more Time domain nuclear magnetic resonance (TD–NMR) has been widely applied in plant science in the last four decades. Several TD–NMR instruments and methods have been developed for laboratory, green-house, and field studies. This mini-review focuses on the recent TD–NMR pulse sequences applied in plant science. One of the sequences measures the transverse relaxation time (T2) with minimal sample heating, using a lower refocusing flip angle and consequently lower specific absorption rate than that of conventional CPMG. Other sequences are based on a continuous wave free precession (CWFP) regime used to enhance the signal-to-noise ratio, to measure longitudinal (T1) and transverse relaxation time in a single shot experiment, and as alternative 2D pulse sequences to obtain T1–T2 and diffusion-T1 correlation maps. This review also presents some applications of these sequences in plant science.
Phenylphenalenones, metabolites found in Schiekia timida (Haemodoraceae), are a class of speciali... more Phenylphenalenones, metabolites found in Schiekia timida (Haemodoraceae), are a class of specialized metabolites with many biological activities, being phytoalexins in banana plants. In the constant search to solve the problem of glyphosate and to avoid resistance to commercial herbicides, this work aimed to investigate the phytotoxic effect of the methanolic extract of S. timida seeds. The chemical composition of the seed extract was directly investigated by NMR and UPLC-QToF MS and the pre- and post-emergence phytotoxic effect on a eudicotyledonous model (Lactuca sativa) and a monocotyledonous model (Allium cepa) was evaluated through germination and seedling growth tests. Three concentrations of the extract (0.25, 0.50, and 1.00 mg/mL) were prepared, and four replicates for each of them were analyzed. Three major phenylphenalenones were identified by NMR spectroscopy: 4-hydroxy-anigorufone, methoxyanigorufone, and anigorufone, two of those reported for the first time in S. timida...
Doxorubicin and cisplatin are used in breast cancer treatment. However, the resistance of tumor c... more Doxorubicin and cisplatin are used in breast cancer treatment. However, the resistance of tumor cells to these drugs is a fundamental problem in tumor management. The nuclear magnetic resonance spectroscopy (NMR) has been used to investigate metabolic profile of cancer cells, especially 1 H HRMAS technique, allowing a contribution for this area.
Portable spectrometers are promising tools that can be an alternative way, for various purposes, ... more Portable spectrometers are promising tools that can be an alternative way, for various purposes, of analyzing food quality, such as monitoring in a few seconds the internal quality during fruit ripening in the field. A portable/handheld (palm-sized) near-infrared (NIR) spectrometer (Neospectra, Si-ware) with spectral range of 1295–2611 nm, equipped with a micro-electro-mechanical system (MEMs), was used to develop prediction models to evaluate tomato quality attributes non-destructively. Soluble solid content (SSC), fructose, glucose, titratable acidity (TA), ascorbic, and citric acid contents of different types of fresh tomatoes were analyzed with standard methods, and those values were correlated to spectral data by partial least squares regression (PLSR). Fresh tomato samples were obtained in 2018 and 2019 crops in commercial production, and four fruit types were evaluated: Roma, round, grape, and cherry tomatoes. The large variation in tomato types and having the fruits from dis...
International Journal of Environmental Research and Public Health, 2020
The COVID-19 infection, caused by SARS-CoV-2, is inequitably distributed and more lethal among po... more The COVID-19 infection, caused by SARS-CoV-2, is inequitably distributed and more lethal among populations with lower socioeconomic status. Direct contact with contaminated surfaces has been among the virus sources, as it remains infective up to days. Several disinfectants have been shown to inactivate SARS-CoV-2, but they rapidly evaporate, are flammable or toxic and may be scarce or inexistent for vulnerable populations. Therefore, we are proposing simple, easy to prepare, low-cost and efficient antiviral films, made with a widely available dishwashing detergent, which can be spread on hands and inanimate surfaces and is expected to maintain virucidal activity for longer periods than the current sanitizers. Avian coronavirus (ACoV) was used as model of the challenge to test the antivirus efficacy of the proposed films. Polystyrene petri dishes were covered with a thin layer of detergent formula. After drying, the films were exposed to different virus doses for 10 min and virus inf...
Moderate supplementation with extract of mate to a standard broiler diet in feeding experiment wi... more Moderate supplementation with extract of mate to a standard broiler diet in feeding experiment with 5 treatment groups was found to increase production of endogenous antioxidants in muscles, improving meat quality and storage stability. For addition of 250 or 500 mg extract per kg feed, pre-cooked meatballs made from the breast muscles had a significant lower level of secondary lipid oxidation products during one week of chill storage. Addition of 750 or 1000 mg extract per kg feed had an increasing prooxidative effect during storage of the meatballs. For the moderate levels of plant phenols in feed, a metabolic study based on nuclear magnetic resonance (NMR) spectroscopy of meat extracts showed that mate extract added to the feed increased the muscle level of antioxidative peptides like anserine, while indication of toxic effects was noted for the higher levels of feed additives. Rate of formation of radicals as detected by electron paramagnetic resonance (EPR) spectroscopy was found to correlate with the oxidative damage and a kinetic analysis demonstrated that the antioxidative effect of mate supplemented to the feed could be assigned to radical scavengers present in the meat. These findings for the monogastric animals are different from results previously obtained for ruminants, where plant phenols rather seem to affect the microflora of the digestive tract.
Dr. Colnago is a specialist in in vivo or in vitro Nuclear Magnetic Resonance (NMR) applied to bi... more Dr. Colnago is a specialist in in vivo or in vitro Nuclear Magnetic Resonance (NMR) applied to biological systems and in the development of NMR instrumentation for analysis of chemicals, food, fuels and other products. His researches also include the development and application of other physical methods for the analysis of biological systems of agricultural interest. His contribution to science was recognized through awards such as: "Highlight in NMR" (2014) by the Association of Magnetic Resonance Users (AUREMN); the "Postgraduate Award", by the Institute of Chemistry of the University of São Paulo in São Carlos (IQSC/USP), for a publication that presented the biggest impact factor in 2012 in the area of Analytical and Inorganic Chemistry; the "Order of Merit Commendation Domingos Martins", by the Legislative Assembly of the State of Espírito Santo, Brazil (2010); and prizes from the Embrapa Awards System (2001 and 1999). Dr. Colnago and his team are proposing the use of low field NMR using permanent magnets to investigate adulterations in fresh and processed foods, biofuels and biomaterials, and to monitor electrochemical reactions in situ, among other applications. In addition to the reduced cost of analysis, which can be tens of times lower than the costs of superconducting NMR equipment, low field NMR equipment allows fast and non-invasive analysis of in natura foods such as fruits, meats and seeds, as well as in the determination of the quality of industrialized foods such as olive oils, mayonnaise, sauces and jellies, without violation of the packaging Variety of products that can be analyzed by low field NMR
This review discusses the theory and applications of the Continuous Wave Free Precession (CWFP) s... more This review discusses the theory and applications of the Continuous Wave Free Precession (CWFP) sequence in low-field, time-domain nuclear magnetic resonance (TD-NMR). CWFP is a special case of the Steady State Free Precession (SSFP) regime that is obtained when a train of radiofrequency pulses, separated by a time interval Tp shorter than the effective transverse relaxation time (T2*), is applied to a sample. Unlike regular pulsed experiments, in the CWFP regime, the amplitude is not dependent on T1. Therefore, Tp should be as short as possible (limited by hardware). For Tp < 0.5 ms, thousands of scans can be performed per second, and the signal to noise ratio can be enhanced by more than one order of magnitude. The amplitude of the CWFP signal is dependent on T1/T2; therefore, it can be used in quantitative analyses for samples with a similar relaxation ratio. The time constant to reach the CWFP regime (T*) is also dependent on relaxation times and flip angle (θ). Therefore, T*...
Unilateral nuclear magnetic resonance (UNMR) spectrometers have been applied in a variety of fiel... more Unilateral nuclear magnetic resonance (UNMR) spectrometers have been applied in a variety of fields such as petrochemistry, materials science, and process control (1) . In UNMR measurements the sample is placed outside of the UNMR sensor and the signal intensity is reduced almost exponentially as the sample-to-sensor distances increases. To expand the detection limits of remote UNMR sensors, wireless inductive coupling was proposed and tested. This strategy was proved to reduce signal attenuation due to sample detachment from sensor, resulting in an increase in detection distance by one order of magnitude (i.e., from few millimeters to few centimeters). This novel approach broadens the potential applications of UNMR sensors and opens new opportunities in several areas, from chemical to biomedical applications.
Introduction-Solid-state NMR (SSNMR) spectroscopy methods provide chemical environment and ultras... more Introduction-Solid-state NMR (SSNMR) spectroscopy methods provide chemical environment and ultrastructural details that are not easily accessible by other non-destructive, high-resolution spectral techniques. High-resolution magic angle spinning (HR-MAS) has been widely used to obtain the metabolic profile of a heterogeneous sample, combining the resolution enhancement provided by MAS in SSNMR with the shimming and locking procedures in liquid-state NMR. Objective-In this work, we explored the feasibility of using the HR-MAS and SSNMR techniques to identify metabolic changes in soybean leaves subjected to water-deficient conditions. Methodology-Control and water-deficient soybean leaves were analysed using one-dimensional (1D) HR-MAS and SSNMR. Total RNA was extracted from the leaves for the transcriptomic analysis. Results-The 1 H HR-MAS and CP-MAS 13 C{ 1 H} spectra of soybean leaves grown with and without water deficiency stress revealed striking differences in metabolites. A total of 30 metabolites were identified, and the impact of water deficiency on the metabolite profile of soybean leaves was to induce amino acid synthesis. High expression levels of genes required for amino acid biosynthesis were highly correlated with the compounds identified by 1 H HR-MAS. Conclusions-The integration of the 1 H HR-MAS and SSNMR spectra with the transcriptomic data provided a complete picture of the major changes in the metabolic profile of soybeans in response to water deficiency.
Doxorubicin (Doxo), cisplatin (Cis), and tamoxifen (Tamo) are part of many chemotherapeutic regim... more Doxorubicin (Doxo), cisplatin (Cis), and tamoxifen (Tamo) are part of many chemotherapeutic regimens. However, there have been limited studies of the way metabolism in breast cancer is affected by chemotherapy. We studied, through (1)H high-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy, the metabolic profile of human breast cancer MCF-7 control (Con) cells as well as MCF-7 cells treated with Tamo, Cis, and Doxo. (1)H HR-MAS NMR single-pulse spectra evidenced signals from the cell compounds, including fatty acids (membranes), water-soluble proteins, and metabolites. The spectra showed that phosphocholine (i.e., biomarker of breast cancer malignant transformation) signals were stronger in Con than in treated cells. Betaine (i.e., the major osmolyte in cells) was observed at similar concentrations in MCF-7 control and treated cells but was absent in nontumor MCF-10A cells. The NMR spectra acquired with the Carr-Purcell-Meiboom-Gill (CPMG) pulse se...
Considering the need for knowing the amount of biodiesel in fuels, in order to attend several leg... more Considering the need for knowing the amount of biodiesel in fuels, in order to attend several legislations around the world, this work aimed to develop a new, rapid, and nondestructive time-domain nuclear magnetic resonance (TD-NMR)based method for the biodiesel content determination in diesel−biodiesel blends. Main findings have revealed that both the transverse relaxation time (T 2) and signal areas from relaxation spectra are highly correlated to biodiesel content in the fuel samples. The highest correlation was reached by applying PLS multivariate regression over T 2 decay curve profiles. Therefore, both univariate and multivariate approaches were able to determine biodiesel content in diesel−biodiesel blends with high accuracy directly from fuel samples in a simple, fast, and inexpensive way.
The strong effect of magnetic field on the electrochemical (EC) reduction of a diamagnetic specie... more The strong effect of magnetic field on the electrochemical (EC) reduction of a diamagnetic species was monitored in situ in a 600 MHz (14 T) NMR spectrometer. Throughout EC-NMR experiments, the diamagnetic species is influenced by the Lorentz force (cross product of current density and magnetic field), which in turn acts on analyte transport and, as a result, enhances reaction rates. This phenomenon, known as magnetoelectrolysis, has not been considered in several in situ EC-NMR studies in solution, electron paramagnetic resonance (EC-EPR) spectroscopy, and magnetic resonance imaging (EC-MRI) involving the oxidation and reduction of organic compounds and lithium ion batteries. Recently, we have demonstrated the presence of this effect in the electroplating of a paramagnetic ion species by monitoring it in situ in a low-field (0.23 T) NMR spectrometer. In this report, a ca. five-fold enhancement in the electroreduction rate of benzoquinone was observed when the analyses were performe...
The aim of this paper was to present a simple and fast way of simulating Nuclear Magnetic Resonan... more The aim of this paper was to present a simple and fast way of simulating Nuclear Magnetic Resonance signals using the Bloch equations. These phenomenological equations describe the classical behavior of macroscopic magnetization and are easily simulated using rotation matrices. Many NMR pulse sequences can be simulated with this formalism, allowing a quantitative description of the influence of many experimental parameters. Finally, the paper presents simulations of conventional sequences such as Single Pulse, Inversion Recovery, Spin Echo and CPMG.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
The present study explored changes in the meat metabolome of animals subjected to different finis... more The present study explored changes in the meat metabolome of animals subjected to different finishing systems and growth rates. Thirty-six Angus × Nellore crossbred steers were used in a completely randomized design with four treatments: (1) feedlot system with high average daily gain (ADG; FH); (2) feedlot system with low ADG (FL); (3) pasture system with high ADG (PH); and (4) pasture system with low ADG (PL). After harvest and chilling, Longissimus thoracis (LT) muscle samples were taken for metabolite profile analysis using nuclear magnetic resonance. Spectrum was analyzed using chenomx software, and multi- and mega-variate data analyses were performed. The PLS-DA showed clear separation between FH and PL groups and overlap among treatments with different finishing systems but similar for matching ADG (FL and PH) treatments. Using a VIP cut-off of around 1.0, ATP and fumarate were shown to be greater in meat from PL cattle, while succinate, leucine, AMP, glutamate, carnosine, in...
Cariniana estrellensis (Raddi) Kuntze seedlings have been used in forest restoration programs in ... more Cariniana estrellensis (Raddi) Kuntze seedlings have been used in forest restoration programs in the Atlantic Forest biome. However, despite the economic and ecological relevance of this species, to date no general method for rapid identification of primary and secondary metabolites of C. estrellensis leaves has been reported. In this work, we explore the feasibility of using rapid analysis by nuclear magnetic resonance techniques and liquid chromatography coupled to diode array, charged aerosol, and mass detection. The main secondary metabolites identified were hydrolysable tannins, quinic acid, hydroxycinnamic acids (trans-p-coumaric acid, cis-p-coumaric acid, and trans-ferulic acid), and flavonoids (kaempferol and quercetin derivatives). These compounds are particularly useful as chemotaxonomic markers for the genus Cariniana and for the family Lecythidaceae, and may also be important for pharmacological uses and for the survival of the seedlings in reforestation programs.
Low field time-domain nuclear magnetic resonance (TD-NMR) relaxometry of paramagnetic metal catio... more Low field time-domain nuclear magnetic resonance (TD-NMR) relaxometry of paramagnetic metal cations (PMC) has been widely used to study and improve contrast agents for magnetic resonance imaging (MRI). However, despite its remarkable potential, TD-NMR is rarely used to study PMC complexes, and coordination compounds in non-biomedical application. Therefore, this review aimed to provide comprehensive information not only to non-nuclear magnetic resonance (NMR) relaxation specialists, but also to scientists from distinct levels and expertise, as a way to pave the path for modern analytical and research of PMC complexes. Some fundamental concepts about NMR, paramagnetic relaxation mechanism, as well as traditional and modern methods to measure the longitudinal (T1) and transverse (T2) relaxation times constants are addressed. Here, we address some applications in analytical, electrochemical, and inorganic chemistry, electrodeposition reactions, as well as studies on PMC complexes and c...
Time domain nuclear magnetic resonance (TD–NMR) has been widely applied in plant science in the l... more Time domain nuclear magnetic resonance (TD–NMR) has been widely applied in plant science in the last four decades. Several TD–NMR instruments and methods have been developed for laboratory, green-house, and field studies. This mini-review focuses on the recent TD–NMR pulse sequences applied in plant science. One of the sequences measures the transverse relaxation time (T2) with minimal sample heating, using a lower refocusing flip angle and consequently lower specific absorption rate than that of conventional CPMG. Other sequences are based on a continuous wave free precession (CWFP) regime used to enhance the signal-to-noise ratio, to measure longitudinal (T1) and transverse relaxation time in a single shot experiment, and as alternative 2D pulse sequences to obtain T1–T2 and diffusion-T1 correlation maps. This review also presents some applications of these sequences in plant science.
Phenylphenalenones, metabolites found in Schiekia timida (Haemodoraceae), are a class of speciali... more Phenylphenalenones, metabolites found in Schiekia timida (Haemodoraceae), are a class of specialized metabolites with many biological activities, being phytoalexins in banana plants. In the constant search to solve the problem of glyphosate and to avoid resistance to commercial herbicides, this work aimed to investigate the phytotoxic effect of the methanolic extract of S. timida seeds. The chemical composition of the seed extract was directly investigated by NMR and UPLC-QToF MS and the pre- and post-emergence phytotoxic effect on a eudicotyledonous model (Lactuca sativa) and a monocotyledonous model (Allium cepa) was evaluated through germination and seedling growth tests. Three concentrations of the extract (0.25, 0.50, and 1.00 mg/mL) were prepared, and four replicates for each of them were analyzed. Three major phenylphenalenones were identified by NMR spectroscopy: 4-hydroxy-anigorufone, methoxyanigorufone, and anigorufone, two of those reported for the first time in S. timida...
Doxorubicin and cisplatin are used in breast cancer treatment. However, the resistance of tumor c... more Doxorubicin and cisplatin are used in breast cancer treatment. However, the resistance of tumor cells to these drugs is a fundamental problem in tumor management. The nuclear magnetic resonance spectroscopy (NMR) has been used to investigate metabolic profile of cancer cells, especially 1 H HRMAS technique, allowing a contribution for this area.
Portable spectrometers are promising tools that can be an alternative way, for various purposes, ... more Portable spectrometers are promising tools that can be an alternative way, for various purposes, of analyzing food quality, such as monitoring in a few seconds the internal quality during fruit ripening in the field. A portable/handheld (palm-sized) near-infrared (NIR) spectrometer (Neospectra, Si-ware) with spectral range of 1295–2611 nm, equipped with a micro-electro-mechanical system (MEMs), was used to develop prediction models to evaluate tomato quality attributes non-destructively. Soluble solid content (SSC), fructose, glucose, titratable acidity (TA), ascorbic, and citric acid contents of different types of fresh tomatoes were analyzed with standard methods, and those values were correlated to spectral data by partial least squares regression (PLSR). Fresh tomato samples were obtained in 2018 and 2019 crops in commercial production, and four fruit types were evaluated: Roma, round, grape, and cherry tomatoes. The large variation in tomato types and having the fruits from dis...
International Journal of Environmental Research and Public Health, 2020
The COVID-19 infection, caused by SARS-CoV-2, is inequitably distributed and more lethal among po... more The COVID-19 infection, caused by SARS-CoV-2, is inequitably distributed and more lethal among populations with lower socioeconomic status. Direct contact with contaminated surfaces has been among the virus sources, as it remains infective up to days. Several disinfectants have been shown to inactivate SARS-CoV-2, but they rapidly evaporate, are flammable or toxic and may be scarce or inexistent for vulnerable populations. Therefore, we are proposing simple, easy to prepare, low-cost and efficient antiviral films, made with a widely available dishwashing detergent, which can be spread on hands and inanimate surfaces and is expected to maintain virucidal activity for longer periods than the current sanitizers. Avian coronavirus (ACoV) was used as model of the challenge to test the antivirus efficacy of the proposed films. Polystyrene petri dishes were covered with a thin layer of detergent formula. After drying, the films were exposed to different virus doses for 10 min and virus inf...
Moderate supplementation with extract of mate to a standard broiler diet in feeding experiment wi... more Moderate supplementation with extract of mate to a standard broiler diet in feeding experiment with 5 treatment groups was found to increase production of endogenous antioxidants in muscles, improving meat quality and storage stability. For addition of 250 or 500 mg extract per kg feed, pre-cooked meatballs made from the breast muscles had a significant lower level of secondary lipid oxidation products during one week of chill storage. Addition of 750 or 1000 mg extract per kg feed had an increasing prooxidative effect during storage of the meatballs. For the moderate levels of plant phenols in feed, a metabolic study based on nuclear magnetic resonance (NMR) spectroscopy of meat extracts showed that mate extract added to the feed increased the muscle level of antioxidative peptides like anserine, while indication of toxic effects was noted for the higher levels of feed additives. Rate of formation of radicals as detected by electron paramagnetic resonance (EPR) spectroscopy was found to correlate with the oxidative damage and a kinetic analysis demonstrated that the antioxidative effect of mate supplemented to the feed could be assigned to radical scavengers present in the meat. These findings for the monogastric animals are different from results previously obtained for ruminants, where plant phenols rather seem to affect the microflora of the digestive tract.
Dr. Colnago is a specialist in in vivo or in vitro Nuclear Magnetic Resonance (NMR) applied to bi... more Dr. Colnago is a specialist in in vivo or in vitro Nuclear Magnetic Resonance (NMR) applied to biological systems and in the development of NMR instrumentation for analysis of chemicals, food, fuels and other products. His researches also include the development and application of other physical methods for the analysis of biological systems of agricultural interest. His contribution to science was recognized through awards such as: "Highlight in NMR" (2014) by the Association of Magnetic Resonance Users (AUREMN); the "Postgraduate Award", by the Institute of Chemistry of the University of São Paulo in São Carlos (IQSC/USP), for a publication that presented the biggest impact factor in 2012 in the area of Analytical and Inorganic Chemistry; the "Order of Merit Commendation Domingos Martins", by the Legislative Assembly of the State of Espírito Santo, Brazil (2010); and prizes from the Embrapa Awards System (2001 and 1999). Dr. Colnago and his team are proposing the use of low field NMR using permanent magnets to investigate adulterations in fresh and processed foods, biofuels and biomaterials, and to monitor electrochemical reactions in situ, among other applications. In addition to the reduced cost of analysis, which can be tens of times lower than the costs of superconducting NMR equipment, low field NMR equipment allows fast and non-invasive analysis of in natura foods such as fruits, meats and seeds, as well as in the determination of the quality of industrialized foods such as olive oils, mayonnaise, sauces and jellies, without violation of the packaging Variety of products that can be analyzed by low field NMR
This review discusses the theory and applications of the Continuous Wave Free Precession (CWFP) s... more This review discusses the theory and applications of the Continuous Wave Free Precession (CWFP) sequence in low-field, time-domain nuclear magnetic resonance (TD-NMR). CWFP is a special case of the Steady State Free Precession (SSFP) regime that is obtained when a train of radiofrequency pulses, separated by a time interval Tp shorter than the effective transverse relaxation time (T2*), is applied to a sample. Unlike regular pulsed experiments, in the CWFP regime, the amplitude is not dependent on T1. Therefore, Tp should be as short as possible (limited by hardware). For Tp < 0.5 ms, thousands of scans can be performed per second, and the signal to noise ratio can be enhanced by more than one order of magnitude. The amplitude of the CWFP signal is dependent on T1/T2; therefore, it can be used in quantitative analyses for samples with a similar relaxation ratio. The time constant to reach the CWFP regime (T*) is also dependent on relaxation times and flip angle (θ). Therefore, T*...
Unilateral nuclear magnetic resonance (UNMR) spectrometers have been applied in a variety of fiel... more Unilateral nuclear magnetic resonance (UNMR) spectrometers have been applied in a variety of fields such as petrochemistry, materials science, and process control (1) . In UNMR measurements the sample is placed outside of the UNMR sensor and the signal intensity is reduced almost exponentially as the sample-to-sensor distances increases. To expand the detection limits of remote UNMR sensors, wireless inductive coupling was proposed and tested. This strategy was proved to reduce signal attenuation due to sample detachment from sensor, resulting in an increase in detection distance by one order of magnitude (i.e., from few millimeters to few centimeters). This novel approach broadens the potential applications of UNMR sensors and opens new opportunities in several areas, from chemical to biomedical applications.
Introduction-Solid-state NMR (SSNMR) spectroscopy methods provide chemical environment and ultras... more Introduction-Solid-state NMR (SSNMR) spectroscopy methods provide chemical environment and ultrastructural details that are not easily accessible by other non-destructive, high-resolution spectral techniques. High-resolution magic angle spinning (HR-MAS) has been widely used to obtain the metabolic profile of a heterogeneous sample, combining the resolution enhancement provided by MAS in SSNMR with the shimming and locking procedures in liquid-state NMR. Objective-In this work, we explored the feasibility of using the HR-MAS and SSNMR techniques to identify metabolic changes in soybean leaves subjected to water-deficient conditions. Methodology-Control and water-deficient soybean leaves were analysed using one-dimensional (1D) HR-MAS and SSNMR. Total RNA was extracted from the leaves for the transcriptomic analysis. Results-The 1 H HR-MAS and CP-MAS 13 C{ 1 H} spectra of soybean leaves grown with and without water deficiency stress revealed striking differences in metabolites. A total of 30 metabolites were identified, and the impact of water deficiency on the metabolite profile of soybean leaves was to induce amino acid synthesis. High expression levels of genes required for amino acid biosynthesis were highly correlated with the compounds identified by 1 H HR-MAS. Conclusions-The integration of the 1 H HR-MAS and SSNMR spectra with the transcriptomic data provided a complete picture of the major changes in the metabolic profile of soybeans in response to water deficiency.
Doxorubicin (Doxo), cisplatin (Cis), and tamoxifen (Tamo) are part of many chemotherapeutic regim... more Doxorubicin (Doxo), cisplatin (Cis), and tamoxifen (Tamo) are part of many chemotherapeutic regimens. However, there have been limited studies of the way metabolism in breast cancer is affected by chemotherapy. We studied, through (1)H high-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy, the metabolic profile of human breast cancer MCF-7 control (Con) cells as well as MCF-7 cells treated with Tamo, Cis, and Doxo. (1)H HR-MAS NMR single-pulse spectra evidenced signals from the cell compounds, including fatty acids (membranes), water-soluble proteins, and metabolites. The spectra showed that phosphocholine (i.e., biomarker of breast cancer malignant transformation) signals were stronger in Con than in treated cells. Betaine (i.e., the major osmolyte in cells) was observed at similar concentrations in MCF-7 control and treated cells but was absent in nontumor MCF-10A cells. The NMR spectra acquired with the Carr-Purcell-Meiboom-Gill (CPMG) pulse se...
Uploads
Papers by luiz colnago