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Tomato fruit is susceptible to chilling injury (CI) during its postharvest handling at low temperature. The symptoms caused by this physiological disorder have been commonly evaluated by visual inspection at a macro-observation scale on fruit surface; however, the structure at deeper scales is also affected by CI. This work aimed to propose a descriptive model of the CI development in tomato tissue under the micro-scale, micro-nano-scale and nano-scale approaches using fractal analysis. For that, quality and fractal parameters were determined. In this sense, light microscopy, Environmental Scanning Electron Microscopy (ESEM) and Atomic Force Microscopy (AFM) were applied to analyse micro-, micro-nano- and nano-scales, respectively. Results showed that the morphology of tomato tissue at the micro-scale level was properly described by the multifractal behaviour. Also, generalised fractal dimension (Dq=0) and texture fractal dimension (FD) of CI-damaged pericarp and cuticle were higher (1.659, 1.601 and 1.746, respectively) in comparison to non-chilled samples (1.606, 1.578 and 1.644, respectively); however, FD was unsuitable to detect morphological changes at the nano-scale. On the other hand, lacunarity represented an appropriate fractal parameter to detect CI symptoms at the nano-scale due to differences observed between damaged and regular ripe tissue (0.044 and 0.025, respectively). The proposed multi-scale approach could improve the understanding of CI as a complex disorder to the development of novel techniques to avoid this postharvest issue at different observation scales.
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Solanum lycopersicum , Frutas/química , Temperatura BaixaRESUMO
INTRODUCTION: Alzheimer disease (AD) is the most common cause of dementia and is considered one of the main causes of disability and dependence affecting quality of life in elderly people and their families. Current pharmacological treatment includes acetylcholinesterase inhibitors (donepezil, galantamine, rivastigmine) and memantine; however, only one-third of patients respond to treatment. Genetic factors have been shown to play a role in this inter-individual variability in drug response. DEVELOPMENT: We review pharmacogenetic reports of AD-modifying drugs, the pharmacogenetic biomarkers included, and the phenotypes evaluated. We also discuss relevant methodological considerations for the design of pharmacogenetic studies into AD. A total of 33 pharmacogenetic reports were found; the majority of these focused on the variability in response to and metabolism of donepezil. Most of the patients included were from Caucasian populations, although some studies also include Korean, Indian, and Brazilian patients. CYP2D6 and APOE are the most frequently studied biomarkers. The associations proposed are controversial. CONCLUSIONS: Potential pharmacogenetic biomarkers for AD have been identified; however, it is still necessary to conduct further research into other populations and to identify new biomarkers. This information could assist in predicting patient response to these drugs and contribute to better treatment decision-making in a context as complex as ageing.
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Doença de Alzheimer , Testes Farmacogenômicos , Acetilcolinesterase/uso terapêutico , Idoso , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Biomarcadores , Donepezila/uso terapêutico , Humanos , Testes Farmacogenômicos/métodosRESUMO
We have studied the Mg doping of cubic GaN grown by plasma-assisted Molecular Beam Epitaxy (PA-MBE) over GaAs (001) substrates. In particular, we concentrated on conditions to obtain heavy p-type doping to achieve low resistance films which can be used in bipolar devices. We simulated the Mg-doped GaN transport properties by density functional theory (DFT) to compare with the experimental data. Mg-doped GaN cubic epitaxial layers grown under optimized conditions show a free hole carrier concentration with a maximum value of 6 × 1019 cm-3 and mobility of 3 cm2/Vs. Deep level transient spectroscopy shows the presence of a trap with an activation energy of 114 meV presumably associated with nitrogen vacancies, which could be the cause for the observed self-compensation behavior in heavily Mg-doped GaN involving Mg-VN complexes. Furthermore, valence band analysis by X-ray photoelectron spectroscopy and photoluminescence spectroscopy revealed an Mg ionization energy of about 100 meV, which agrees quite well with the value of 99.6 meV obtained by DFT. Our results show that the cubic phase is a suitable alternative to generate a high free hole carrier concentration for GaN.
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Self-assembled InN nanocolumns were grown at low temperatures by plasma-assisted molecular beam epitaxy with a high crystalline quality. The self-assembling procedure was carried out on AlN/Al layers on Si(111) substrates avoiding the masking process. The Al interlayer on the Si(111) substrate prevented the formation of amorphous SiN. We found that the growth mechanism at 400 ∘ C of InN nanocolumns started by a layer-layer (2D) nucleation, followed by the growth of 3D islands. This growth mechanism promoted the nanocolumn formation without strain. The nanocolumnar growth proceeded with cylindrical and conical shapes with heights between 250 and 380 nm. Detailed high-resolution transmission electron microscopy analysis showed that the InN nanocolumns have a hexagonal crystalline structure, free of dislocation and other defects. The analysis of the phonon modes also allowed us to identify the hexagonal structure of the nanocolumns. In addition, the photoluminescence spectrum showed an energy transition of 0.72 eV at 20 K for the InN nanocolumns, confirmed by photoreflectance spectroscopy.
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Background and objective Pneumonia remains the main cause of mortality in patients with systemic lupus erythematosus (SLE). The aim of the study was to establish the clinical characteristics, microbiology and risk factors for poor prognosis in patients with SLE and pneumonia. Methods We reviewed medical records of patients with SLE (American College of Rheumatology criteria) and pneumonia who attended the emergency room in a single tertiary care center (January 2010-March 2015). We collected demographics, treatment and disease activity (SLEDAI-2K) data. Severity scales of pneumonia (CURB-65 (acronym for risk factors measured: confusion, urea nitrogen, respiratory rate, blood pressure, 65 years of age and older) and Pneumonia Severity Index (PSI)) were obtained. A negative composite outcome was defined as need for mechanical ventilation, septic shock or death secondary to pneumonia up to 30 days after discharge. We conducted a univariate and multivariable analysis. Results We studied 158 patients (76% women) with 187 episodes of pneumonia. There were no differences in age, SLE duration, SLE activity, treatment or comorbidities between patients with negative composite outcome vs the other group. In 53 episodes, patients presented with a negative composite outcome. Of these, 46 (24.6%) required intubation, 13 (7%) developed shock and 12 (6.4%) died. The most common bacteria isolated was S. aureus, and we observed a high percentage of nonhabitual microorganisms. Fifteen percent of patients who presented with a negative outcome had low values on CURB-65 and PSI scales. Conclusion Patients with SLE and pneumonia have a high risk of complications and present with a high percentage of nonhabitual microorganisms. Severity scales for pneumonia can misclassify as low risk SLE patients with poor prognosis.
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Lúpus Eritematoso Sistêmico/complicações , Pneumonia/mortalidade , Staphylococcus aureus/isolamento & purificação , Adulto , Serviço Hospitalar de Emergência , Feminino , Humanos , Modelos Logísticos , Lúpus Eritematoso Sistêmico/microbiologia , Masculino , México , Análise Multivariada , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Centros de Atenção Terciária , Adulto JovemAssuntos
Displasia Ectodérmica Anidrótica Tipo 1/genética , Ectodisplasinas/genética , Receptor Edar/genética , Mutação , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , México , Linhagem , Fenótipo , Adulto JovemRESUMO
We aimed to explore the possible influence of CYP2C9 (*2, *3 and IVS8-109 A>T), CYP2C19 (*2, *3 and *17) and ABCB1 (1236C>T, 2677G>A/T and 3435C>T) on phenytoin (PHT) plasma concentrations in 64 Mexican Mestizo (MM) patients with epilepsy currently treated with PHT in mono- (n=25) and polytherapy (n=39). Genotype and allele frequencies of these variants were also estimated in 300 MM healthy volunteers. Linear regression models were used to assess associations between the dependent variables (PHT plasma concentration and dose-corrected PHT concentration) with independent variables (CYP2C9, CYP2C19 and ABCB1 genotypes, ABCB1 haplotypes, age, sex, weight, and polytherapy). In multivariate models, CYP2C9 IVS8-109 T was significantly associated with higher PHT plasma concentrations (t(64)=2.27; P=0.03). Moreover, this allele was more frequent in the supratherapeutic group as compared with the subtherapeutic group (0.13 versus 0.03, respectively; P=0.05, Fisher's exact test). Results suggest that CYP2C9 IVS8-109 T allele may decrease CYP2C9 enzymatic activity on PHT. More research is needed to confirm findings.
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Anticonvulsivantes/sangue , Citocromo P-450 CYP2C19/genética , Citocromo P-450 CYP2C9/genética , Epilepsia/tratamento farmacológico , Epilepsia/genética , Variantes Farmacogenômicos/genética , Fenitoína/sangue , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Adolescente , Adulto , Idoso , Anticonvulsivantes/administração & dosagem , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Citocromo P-450 CYP2C19/metabolismo , Citocromo P-450 CYP2C9/metabolismo , Monitoramento de Medicamentos , Epilepsia/sangue , Epilepsia/etnologia , Feminino , Frequência do Gene , Estudos de Associação Genética , Genótipo , Humanos , Modelos Lineares , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Análise Multivariada , Fenótipo , Fenitoína/administração & dosagem , Fatores de Risco , Resultado do Tratamento , Adulto JovemAssuntos
Glucosilceramidase/genética , Mutação , Doença de Parkinson/genética , Idade de Início , Idoso , Códon , Feminino , Humanos , Masculino , México , Pessoa de Meia-IdadeRESUMO
OBJECTIVE: To determine diet and nutrition practices and the economic and social situation in homes with premature infants. MATERIAL AND METHODS: A descriptive cross-sectional study of 100 preterm infants 30 to 36 weeks gestational age, using data obtained on weight, length and head circumference at birth, and whether they were from rural or urban communities. The mothers of premature infants were given a questionnaire to find out the diet and nutrition status, and the economic and social situation in the families. The preterm infants were recruited from Maternal and Child Hospital of Leon, Guanajuato. RESULTS: The mean gestational age was 34 weeks (26 to 36). The mean weight, length, and head circumference at birth were: 2,007 g (659 to 3,750 g), 43.7 cm (30 to 52 cm) and 32.4 cm (28 to 35.5 cm), respectively. Almost all mothers (98%) wished to breastfeed. More than a quarter (26%) of mothers consumed soda drinks twice a week, and preferred processed food instead of preparing it at home. Fresh fruit was consumed on seven, four, and three days per week by 43%, 13%, and 21% of mothers, respectively. These amounts were similar for vegetables, legumes and cereals. Almost all (91%) referred to consuming tortillas every day. The average monthly income was 1,000 to 4,000 pesos (62.5-250 ) in most cases. Drinking water and electricity services were scarce. CONCLUSIONS: Most patients did not have drinking water or electricity services, as well as being on a low income. Diets were inadequate both in quality and type of food. The accessibility to foods was limited. These situations will have an impact on the growth and development of preterm infants.