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Moisture is a key aspect for proper composting, allowing greater efficiency and lower environmental impact. Low-cost real-time moisture determination methods are still a challenge in industrial composting processes. The aim of this study was to design a model of hardware and software that would allow self-adjustment of a low-cost capacitive moisture sensor. Samples of organic composts with distinct waste composition and from different composting stages were used. Machine learning techniques were applied for self-adjustment of the sensor. To validate the model, results obtained in a laboratory by the gravimetric method were used. The proposed model proved to be efficient and reliable in measuring moisture in compost, reaching a correlation coefficient of 0.9939 between the moisture content verified by gravimetric analysis and the prediction obtained by the Sensor Node.
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Compostagem , Indústrias , Aprendizado de Máquina , SoloRESUMO
Composting is useful for treatment of residues from agribusiness, but the potential toxicity of the final compost should be evaluated before its agricultural destination. The objective of this study was to evaluate the physicochemical characteristics and the toxicity of agribusiness residues using onion seeds as bioindicators. All tested treatments were composed by sludge from a swine slaughterhouse and sawdust. Besides the control, which included no additional materials, the other treatments included aviary bedding, rice husk and residue from tobacco industries as structuring materials. After 120 days of composting, for all treatments, the temperature inside the composting piles approached the environmental temperature, the physicochemical parameters indicated that the composts were stabilized and, except for the treatment including tobacco residues, that could be used for agriculture without impairing plant germination. Although the treatments including tobacco residues and rice husk showed evidence of cytotoxicity and genotoxicity at the beginning of the composting period, that was not observed for the treatment including aviary bedding. Such potential toxicity was not observed at the end of composting for any of the tested treatments.
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Compostagem , Oryza , Matadouros , Agricultura , Animais , Esgotos , Solo , SuínosRESUMO
Metal-ligand cluster ions are structurally characterized by means of gas-phase infrared multiple photon dissociation spectroscopy. The mass-selected complexes consist of one or two metal cations M3+ (M = Al, Fe, or Ru) and two to five anionic bidentate acetylacetonate ligands. Experimental IR spectra are compared with different density functional theory calculations, namely, PBE/TZVP, B3LYP/6-31G*, and M06/6-31+G**. Frequency analysis was also performed at different levels, namely, scaled static harmonic and unscaled static anharmonic, or with ab initio molecular dynamics simulations at the PBE/TZVP level. All methods lead to simulated spectra that fit rather well with experimental data, and the spectral red shifts of several main bands, in the 1200 cm-1-1800 cm-1 range, are sensitive to the strength of the metal-ligand interaction and to the spin state of the ion. Due to the rigidity of those complexes, first principles molecular dynamics calculations provide spectra similar to that produced by static calculations that are already able to catch the main spectral signatures using harmonic calculations at the B3LYP/6-31G* level.
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In this work we report an analysis of the bulk phase of 2-methoxyethylammonium nitrate based on ab initio molecular dynamics. The structural and dynamical features of the ionic liquid have been characterized and the computational findings have been compared with the experimental X-ray diffraction patterns, with infrared spectroscopy data, and with the results obtained from molecular dynamics simulations. The experimental infrared spectrum was interpreted with the support of calculated vibrational density of states as well as harmonic frequency calculations of selected gas phase clusters. Particular attention was addressed to the high frequency region of the cation (ω > 2000 cm(-1)), where the vibrational motions involve the NH3+ group responsible for hydrogen bond formation, and to the frequency range 1200-1400 cm(-1) where the antisymmetric stretching mode (ν3) of nitrate is found. Its multiple absorption lines in the liquid arise from the removal of the degeneracy present in the D3h symmetry of the isolated ion. Our ab initio molecular dynamics leads to a rationalization of the frequency shifts and splittings, which are inextricably related to the structural modifications induced by a hydrogen bonding environment. The DFT calculations lead to an inhomogeneous environment.
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We implement all single-qubit operations with fidelities significantly above the minimum threshold required for fault-tolerant quantum computing, using a trapped-ion qubit stored in hyperfine "atomic clock" states of ^{43}Ca^{+}. We measure a combined qubit state preparation and single-shot readout fidelity of 99.93%, a memory coherence time of T_{2}^{*}=50 sec, and an average single-qubit gate fidelity of 99.9999%. These results are achieved in a room-temperature microfabricated surface trap, without the use of magnetic field shielding or dynamic decoupling techniques to overcome technical noise.
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The IRMPD spectrum of the G-quartet-Na(+) complex, in combination with an ab initio molecular dynamic simulation, revealed the presence of two metastable populations of conformers separated by a free energy barrier easily accessible at room temperature.
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Quadruplex G , Gases/química , Sódio/química , Conformação Molecular , Simulação de Dinâmica Molecular , Espectrofotometria Infravermelho , TermodinâmicaRESUMO
OBJECTIVE: To investigate risk factors for delayed sputum culture conversion to negative during anti-tuberculosis treatment, with an emphasis on smoking. DESIGN: Nested case-control study of adults with non-cavitary, culture-confirmed pulmonary tuberculosis (TB) participating in an anti-tuberculosis treatment trial in Brazil. A case of delayed culture conversion was a patient who remained culture-positive after 2 months of treatment. Odds ratios with 95% confidence intervals were calculated. RESULTS: Fifty-three cases and 240 control patients were analyzed. Smokers had three-fold greater odds of remaining culture-positive after 2 months of treatment (P = 0.007) than non-smokers, while smokers and ex-smokers who smoked >20 cigarettes a day had two-fold greater odds of remaining culture-positive after 2 months of treatment (P = 0.045). CONCLUSION: Cigarette smoking adversely affects culture conversion during anti-tuberculosis treatment. Support for smoking cessation should be considered to improve outcomes in TB control programs.
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Mycobacterium tuberculosis/isolamento & purificação , Abandono do Hábito de Fumar , Fumar/efeitos adversos , Escarro/microbiologia , Tuberculose/tratamento farmacológico , Adolescente , Adulto , Antituberculosos/uso terapêutico , Brasil/epidemiologia , Intervalos de Confiança , Seguimentos , Humanos , Pessoa de Meia-Idade , Mycobacterium tuberculosis/efeitos dos fármacos , Razão de Chances , Prevalência , Estudos Retrospectivos , Fatores de Risco , Fumar/epidemiologia , Prevenção do Hábito de Fumar , Resultado do Tratamento , Tuberculose/epidemiologia , Tuberculose/microbiologia , Adulto JovemRESUMO
The description of the electronic structure and magnetic properties of multi-centers transition metal complexes, especially of mixed-valence compounds, still represents a challenge for density functional theory (DFT) methods. The energies and the geometries of the correctly symmetrized low-spin ground state are estimated using the Heisenberg-Dirac-van Vleck spin Hamiltonian within the extended broken symmetry method introduced by Marx and co-workers [Nair et al., J. Chem. Theory Comput. 4, 1174-1188 (2008)]. In the present work we extend the application of this technique, originally implemented using the DFT+U scheme, to the use of hybrid functionals, investigating the ground-state properties of di-iron and di-manganese compounds. The calculated magnetic coupling and vibrational properties of ferredoxin molecular models are in good agreements with experimental results and DFT+U calculations. Six different mixed-valence Mn(III)-Mn(IV) compounds have been extensively studied optimizing the geometry in low-spin, high-spin, and broken-symmetry states and with different functionals. The magnetic coupling constants calculated by the extended broken symmetry approach using B3LYP functional presents a remarkable agreement with the experimental results, revealing that the proposed methodology provides a consistent and accurate DFT approach to the electronic structure of multi-centers transition metal complexes.
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Fenômenos Magnéticos , Compostos Organometálicos/química , Teoria Quântica , Vibração , Ferro/química , Manganês/químicaRESUMO
BACKGROUND: Life expectancy after transplantation has improved, and cancer may soon be the leading cause of late death after transplantation. The guidelines of the American and European societies of nephrology and urology have not yet established the optimal frequency for screening for renal cell carcinoma (RCC) of native kidneys in patients who have undergone renal transplantation. OBJECTIVE: To evaluate the prevalence, prognosis, and risk factors of RCC in a series of patients followed up for 16 years in our transplantation unit. MATERIALS AND METHODS: Our study is a follow-up observational cohort study conducted in 694 consecutive renal transplant recipients admitted to our institution from July 1991 through July 2007. At our institution, ultrasound studies of the native kidneys were performed every 6 months after renal transplantation. RESULTS: In the patient cohort studied, 10 patients developed a renal tumor (1.6% incidence). Three patients died of causes other than recurrence of RCC. Seven patients are alive with no evidence of RCC recurrence or metastatic disease after a mean (range) follow-up of 41 (12-96) months. Acquired cystic kidney disease and dialysis duration were positively associated with development of RCC. CONCLUSIONS: The incidence of RCC in the literature varies between 0.3% and 4.8%. The variability depends on the timing of follow-up, with a higher incidence in prospective studies with strict follow-up. We advise ultrasound studies performed by specialized physicians every 6 months after transplantation. More detailed guidelines designed by the major international transplantation societies are necessary.
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Carcinoma de Células Renais/epidemiologia , Neoplasias Renais/epidemiologia , Transplante de Rim/efeitos adversos , Carcinoma de Células Renais/diagnóstico , Carcinoma de Células Renais/diagnóstico por imagem , Estudos de Coortes , Feminino , Seguimentos , Humanos , Incidência , Rim/diagnóstico por imagem , Neoplasias Renais/diagnóstico , Neoplasias Renais/diagnóstico por imagem , Masculino , Prevalência , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , UltrassonografiaRESUMO
Time-resolved femtosecond spectroscopy can improve the application of green fluorescent proteins (GFPs) as protein-folding reporters. The study of ultrafast excited-state dynamics (ESD) of GFP fused to single chain variable fragment (scFv) antibody fragments, allowed us to define and measure an empirical parameter that only depends on the folding quality (FQ) of the fusion. This method has been applied to the analysis of genetic fusions expressed in the bacterial cytoplasm and allowed us to distinguish folded and thus functional antibody fragments (high FQ) with respect to misfolded antibody fragments. Moreover, these findings were strongly correlated to the behavior of the same scFvs expressed in animal cells. This method is based on the sensitivity of the ESD to the modifications in the tertiary structure of the GFP induced by the aggregation state of the fusion partner. This approach may be applicable to the study of the FQ of polypeptides over-expressed under reducing conditions.
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Citoplasma/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Fragmentos de Imunoglobulinas/química , Fragmentos de Imunoglobulinas/metabolismo , Dobramento de Proteína , Proteínas Recombinantes de Fusão/metabolismo , Análise Espectral/métodos , Escherichia coli/metabolismo , Células HeLa , Humanos , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Oxirredução , Eletricidade EstáticaRESUMO
UNLABELLED: No data are available on incisional hernia in renal transplant recipients using a midline incision. This study evaluated the incidence of abdominal wall incisional hernia, comparing two surgical approaches: midline and J-shaped incisions. METHODS: Between 1991 and 2005, 415 consecutive patients underwent renal transplantation: between 1991 and 1997, 139 patients through a lateral incision; between 1997 and 2005, 137 of 276 renal transplant patients via a midline incision, and 139 via a J-shaped incision. We evaluated the incidence of incisional herniae in these patients. Analyzed factor risks included: age, sex, body mass index, diabetes, reoperation, lymphocele, dialysis time, underlying renal disease, and immunosuppressive therapy. RESULTS: During follow-up, 15 patients of 415 transplantations were dead or lost to follow-up. Incisional herniae were identified in 12 cases of 132 (9%) between 1991 and 1997. Between 1997 and 2005 we identified 3 of 133 (2.2%) patients who underwent a midline incision and 15 of 135 (11.1%) who received a J-shaped incision (P=.005). Comparing midline and J-shaped incisions before and after 1997, the incidence reduction was significant (P=.01). Comparing the incidence among patients treated with J-shaped incision before versus after 1997, the increased incidence was insignificant (P=.6). Multivariate analysis found the most important risk factor was obesity followed by polycystic kidney disease, reoperation, wound infection, and mycophenolate mofetil therapy. CONCLUSIONS: Our data showed an advantage of a midline incision. Strategies to prevent surgical complications, such as abdominal wall relaxation and poor cosmetic results, are needed; the midline incision may be a possible alternative to address this complication.
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Parede Abdominal/patologia , Transplante de Rim/métodos , Adolescente , Adulto , Idoso , Criança , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/prevenção & controle , Estudos Retrospectivos , Resultado do TratamentoRESUMO
We show that trapped ions can be used to simulate a highly symmetrical Hamiltonian with eigenstates naturally protected against local sources of decoherence. This Hamiltonian involves long-range coupling between particles and provides a more efficient protection than nearest neighbor models discussed in previous works. Our results open the perspective of experimentally realizing, in controlled atomic systems, complex entangled states with decoherence times up to 9 orders of magnitude longer than isolated quantum systems.
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1H MRS signals of glutathione and of free glutamate were examined in samples from cultured tumour cells, namely MCF-7 from mammary carcinoma and TG98 from malignant glioma, with the aim of relating signal intensities to aspects of GSH metabolism. Spectra of cells harvested at different cell densities suggest that GSH and glu signal intensities are related to cell density and proliferation and their ratio is dependent on the activity of the gamma-glutamyl cysteine synthetase. The hypothesis is confirmed by experiments performed on cells treated with buthionine sulfoximine that inhibits the enzyme activity.
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Glutationa/metabolismo , Espectroscopia de Ressonância Magnética , Neoplasias/metabolismo , Neoplasias/patologia , Butionina Sulfoximina/farmacologia , Linhagem Celular Tumoral , Cisteína/análise , Ácido Glutâmico/análise , Glutationa/análise , Humanos , Prótons , Fatores de TempoRESUMO
Much attention has been devoted in the past to monitor changes of mobile lipid (ML) (1)H MRS signals in spectra of tumour cells. The purpose of this work is to exploit ML signals to provide information on cell metabolism after irradiation, comparing tumour cells characterised by different radiosensitivity and relating MRS findings to changes in cell proliferation and delays in cell cycle phases. Irradiated HeLa cells present less intense ML signals with respect to controls. The opposite is true for MCF-7 cells. A G(2) arrest is observed for both cell lines after irradiation. In HeLa cells, G(1) decreases and S phase is maintained; a sub G(1) peak is also visible. In MCF-7 cells, G(1) is decreased and S phase is strongly reduced, while no sub G(1) is present. The observed changes in ML are tentatively associated to cell cycle regulation of phospholipid synthesis. Mathematical modelling of ML variations is in progress.
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Ciclo Celular/fisiologia , Ciclo Celular/efeitos da radiação , Proliferação de Células/efeitos da radiação , Metabolismo dos Lipídeos/efeitos da radiação , Células Cultivadas , Relação Dose-Resposta à Radiação , Humanos , Espectroscopia de Ressonância Magnética , Prótons , Doses de RadiaçãoRESUMO
The purpose of this work was to examine the dosimetric performances of the radiochromic Fricke-Agarose-Xylenol Orange gel by optical measurements in order to perform dose reconstructions, in view of a future development for 3-D maps. Optical images and dose-response curves of the gel were obtained by a CCD-based device, originally designed for reading radiochromic films, that was modified to meet the optical properties of the dosemeter. With a resolution of 0.18 x 0.18 mm the optimum range of doses in which per cent uncertainty is lower than 2% was 3-10 Gy. The minimum detectable dose, estimated as the absorbed dose corresponding to 3 SD above background, was 0.1 Gy. With a resolution of 1.98 x 1.98 mm the optimum range of doses in which per cent uncertainty is lower than 2% was 0.3-10 Gy. The minimum detectable dose, estimated as the absorbed dose corresponding to 3 SD above background, was 0.015 Gy. The comparison with alanine dosemeters in the dose range 7-10 Gy showed agreement within a few per cent and the same agreement was observed for the comparison with TLD in the range 1-3 Gy.
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Géis/química , Géis/efeitos da radiação , Nanotecnologia/instrumentação , Óptica e Fotônica/instrumentação , Fotometria/instrumentação , Radiometria/instrumentação , Relação Dose-Resposta à Radiação , Desenho de Equipamento , Análise de Falha de Equipamento , Miniaturização , Nanotecnologia/métodos , Fotometria/métodos , Doses de Radiação , Radiometria/métodos , Reprodutibilidade dos Testes , Espalhamento de Radiação , Sensibilidade e EspecificidadeRESUMO
UNLABELLED: Pancreas transplant (Ptx) is the gold standard for the treatment of type I diabetes, mainly when associated with renal failure. The number of Ptx is increasing worldwide, but in developing countries, such as Brazil, the number of centers is small and transplant surgeons need to practice the technique. METHODS: For this model, 21 pancreas harvestings were performed in patient corpses after death from extra-abdominal causes, without pancreatic disease and peritoneal or systemic infection. The vessels of the grafts were prepared on the backtable according to the usual practice in humans. The pancreas was implanted in the inferior vena cava and aorta of mixed breed dogs, with 10 exocrine-bladder drainage and 11 duodenum-ileal anastomosis. RESULTS: There were anastomotic strictures of the portal vein in dogs 1 and 2. There was no arterial stricture or large bleeding. None of the animals died until the revascularization of the graft. Dogs 2, 5, and 8 died during the exocrine anastomosis. The arterial flow was initially high, but at the end of the procedure there were thromboses of small arteries. CONCLUSION: The experimental surgical technique model is feasible, repeating the stages of clinical pancreatic transplantation and allowing the training of surgeons.
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Diabetes Mellitus Tipo 1/cirurgia , Transplante de Pâncreas/educação , Coleta de Tecidos e Órgãos/educação , Animais , Cadáver , Cães , Humanos , Modelos Animais , Transplante de Pâncreas/métodos , Coleta de Tecidos e Órgãos/métodosRESUMO
Ferrous-sulphate infused gels, or 'Fricke gels', encounter great interest in the field of radiation dosimetry, due to their potential for 3D radiation dose mapping. Typically, magnetic resonance (MR) relaxation rates are determined in these systems in order to derive the absorbed dose. However, when large concentration gradients are present, diffusion effects before and during the MR imaging may not be negligible. In these cases, optical techniques may represent a viable alternative. This paper describes research aimed at measuring 3D dose distributions in a Fricke-xylenol orange gel by measuring optical density with a CCD camera. This method is inexpensive and fast. A series of early experiments is described, in which optical density profiles were measured with a commercial microdensitometer for film dosimetry. The light box of the device was modified to work at 567 nm, close to the maximum absorbance of the ferric ion-xylenol orange complex. Under these conditions, the gel shows linearity with dose and high sensitivity.
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Compostos Ferrosos/química , Compostos Ferrosos/efeitos da radiação , Géis/química , Géis/efeitos da radiação , Soluções/química , Soluções/efeitos da radiação , Dosimetria Termoluminescente/instrumentação , Relação Dose-Resposta à Radiação , Desenho de Equipamento , Análise de Falha de Equipamento , Luz , Teste de Materiais , Doses de Radiação , Reprodutibilidade dos Testes , Espalhamento de Radiação , Sensibilidade e Especificidade , Dosimetria Termoluminescente/métodosRESUMO
In Fricke-agarose gels, an accurate determination of the spatial dose distribution is hindered by the diffusion of ferric ions. In this work, a model was developed to describe the diffusion process within gel samples of finite length and, thus, permit the reconstruction of the initial spatial distribution of the ferric ions. The temporal evolution of the ion concentration as a function of the initial concentration is derived by solving Fick's second law of diffusion in two dimensions with boundary reflections. The model was applied to magnetic resonance imaging data acquired at high spatial resolution (0.3 mm) and was found to describe accurately the observed diffusion effects.
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Compostos Ferrosos/química , Compostos Ferrosos/efeitos da radiação , Modelos Químicos , Modelos Moleculares , Sefarose/química , Sefarose/efeitos da radiação , Soluções/química , Soluções/efeitos da radiação , Dosimetria Termoluminescente/instrumentação , Simulação por Computador , Difusão , Relação Dose-Resposta à Radiação , Desenho de Equipamento , Análise de Falha de Equipamento , Géis/química , Géis/efeitos da radiação , Troca Iônica , Teste de Materiais , Doses de Radiação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Dosimetria Termoluminescente/métodosRESUMO
Inhibition of apoptosis in tumour cells may depend on intracellular reduced glutathione (GSH) level. In this work, GSH levels were studied by (1)H MRS in MCF-7 and HeLa cells, characterised by a different radiosensitivity. Annexin-V test showed that the fraction of apoptotic HeLa cells after irradiation is much higher than in control, although MCF-7 cells did not show a significant apoptosis. MRS signals from GSH (G) show lower intensity in HeLa with respect to MCF-7 cells; the opposite is true for free glutamic acid [glu (g)]. After irradiation, the G/g ratio decreases in MCF-7, although remaining approximately constant in HeLa cells. Buthionine sulfoximine (BSO) treated MCF-7 cells show an increase in the percentage of apoptotic cells; in parallel, G/g ratio behaves as in HeLa. This study indicates that GSH level may act as predictive marker of apoptosis by irradiation.
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Apoptose/efeitos da radiação , Biomarcadores Tumorais/análise , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Glutationa/análise , Espectroscopia de Ressonância Magnética/métodos , Prótons , Linhagem Celular Tumoral , Relação Dose-Resposta à Radiação , Células HeLa , Humanos , Doses de Radiação , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
The time evolution of the fluorescence intensity emitted by well-defined ensembles of green fluorescent proteins has been studied by using a standard confocal microscope. In contrast with previous results obtained in single-molecule experiments, the photobleaching of the ensemble is well described by a model based on Lévy statistics. By assuming the presence of thermally activated barriers, this simple model allows us to obtain information about their height distribution.