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1.
J Chromatogr A ; 1644: 462083, 2021 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-33819677

RESUMEN

Meat heating endpoint temperature (EPT) is an important indicator to ensure the safety of cooked meat. Accurately determining the EPT of cooked meat and ready-to-eat meat products is an important strategy to ensure food safety. In this study, a comprehensive metabolic method based on UPLC-Q Exactive and chemometrics was developed to study the metabolites differences among pork roasted at different temperatures in order to select markers indicating EPT and discover new toxic heat-induced compounds. A two-step extraction method was applied to avoid the loss of metabolite information caused by sample preparation. Using chemometrics, the five compounds of creatine, creatinine, 2-amino-1-methyl-6-phenylimidazo (4,5-b) pyridine (PhIP), 2-methyl-6-amino-5-hydroxymethylpyrimidine (TMP) and compound with the m/z of 114.04316 were selected as markers, and four of them were further confirmed by chemical standards. It is worth noting that TMP was discovered in roasted pork for the first time. In addition, targeting studies aimed at quantifying the selected markers were conducted at different thermal processing temperatures. From the quantification results, it can be concluded that the heat temperature not exceed 180 °C is recommended to reduce the content of toxic compounds. This study has proved that the integration of UPLC-Q Exactive and chemometrics could provide an efficient method for the study of markers related to thermal process and new toxic heat-induced compounds.


Asunto(s)
Espectrometría de Masas/métodos , Carne de Cerdo/análisis , Temperatura , Animales , Análisis Discriminante , Imidazoles/análisis , Análisis de los Mínimos Cuadrados , Metabolómica , Análisis Multivariante , Análisis de Componente Principal , Estándares de Referencia , Estadística como Asunto , Porcinos
2.
Nat Protoc ; 16(4): 2257-2285, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33837305

RESUMEN

The ability to identify regulatory interactions that mediate gene expression changes through distal elements, such as risk loci, is transforming our understanding of how genomes are spatially organized and regulated. Capture Hi-C (CHi-C) is a powerful tool to delineate such regulatory interactions. However, primary analysis and downstream interpretation of CHi-C profiles remains challenging and relies on disparate tools with ad-hoc input/output formats and specific assumptions for statistical modeling. Here we present a data processing and interaction calling toolkit (CHiCANE), specialized for the analysis and meaningful interpretation of CHi-C assays. In this protocol, we demonstrate applications of CHiCANE to region capture Hi-C (rCHi-C) and promoter capture Hi-C (pCHi-C) libraries, followed by quality assessment of interaction peaks, as well as downstream analysis specific to rCHi-C and pCHi-C to aid functional interpretation. For a typical rCHi-C/pCHi-C dataset this protocol takes up to 3 d for users with a moderate understanding of R programming and statistical concepts, although this is dependent on dataset size and compute power available. CHiCANE is freely available at https://cran.r-project.org/web/packages/chicane .


Asunto(s)
Genómica/métodos , Secuencias Reguladoras de Ácidos Nucleicos/genética , Elementos de Facilitación Genéticos/genética , Epigenoma , Genoma , Código de Histonas , Modelos Genéticos , Anotación de Secuencia Molecular , Mutación/genética , Polimorfismo de Nucleótido Simple/genética , Regiones Promotoras Genéticas , Sitios de Carácter Cuantitativo/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Estadística como Asunto
3.
J Infect Dev Ctries ; 15(3): 326-332, 2021 03 31.
Artículo en Inglés | MEDLINE | ID: mdl-33839705

RESUMEN

INTRODUCTION: This paper aims to estimate the incubation period and serial intervals for SARS-CoV-2 based on confirmed cases in Jiangxi Province of China and meta-analysis method. METHODOLOGY: Distributions of incubation period and serial interval of Jiangxi epidemic data were fitted by "fitdistrplus" package of R software, and the meta-analysis was conducted by "meta" package of R software. RESULTS: Based on the epidemic data of Jiangxi, we found the median days of incubation period and serial interval were 5.9 days [IQR: 3.8 - 8.6] and 5.7 days [IQR: 3.6 - 8.3], respectively. The median days of the infectivity period at pre-symptomatic was 1.7 days [IQR: 1.1 - 2.4]. The meta-analysis based on 64 papers showed the pooled means of the incubation period and serial interval were 6.25 days (95% CrI: 5.75 - 6.75) and 5.15 days (95% CrI: 4.73 - 5.57), respectively. CONCLUSIONS: Our results contribute to a better understanding of COVID-19 and provide useful parameters for modelling the dynamics of disease transmission. The serial interval is shorter than the incubation period, which indicates that the patients are infectious at pre-symptomatic period, and isolation of detected cases alone is likely to be difficult to halt the spread of SARS-CoV-2.


Asunto(s)
/epidemiología , Periodo de Incubación de Enfermedades Infecciosas , Estadística como Asunto , Adolescente , Adulto , Anciano , Niño , Preescolar , China/epidemiología , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Programas Informáticos , Factores de Tiempo , Adulto Joven
4.
Methods Mol Biol ; 2212: 181-190, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33733357

RESUMEN

If one uses data to identify the most likely epistatic interaction between two genetic units, and then tests if the identified interaction is associated with a phenotype, the nominal statistical evidence will be inflated. Corrections are available but computationally expensive for genome-wide studies. We provide a first-order correction that can be applied in practice with essentially no additional computational cost.


Asunto(s)
Algoritmos , Epistasis Genética , Estudios de Asociación Genética , Modelos Genéticos , Polimorfismo de Nucleótido Simple , Simulación por Computador , Genotipo , Humanos , Reducción de Dimensionalidad Multifactorial , Fenotipo , Estadística como Asunto
8.
J Chromatogr A ; 1642: 462028, 2021 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-33721814

RESUMEN

Measurement of chiral thiol compounds such as glutathione (GSH), cysteine (Cys), and homocysteine (Hcy) in human serum plays an important role in the early diagnosis and warning of cardiovascular disease, neurodegenerative disease, and cancer. We developed a novel chiral mass spectrometry derivatization reagent, (R)-(5-(3-isothiocyanatopyrrolidin-1-yl)-5-oxopentyl) triphenylphosphonium (NCS-OTPP), with triphenylphosphine (TPP) as a basic structure carrying a permanent positive charge for the diastereomeric separation of chiral thiol compounds by ultrahigh-performance liquid chromatography coupled to quadrupole-Orbitrap high resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS). A novel method was developed for simultaneous determination of three kinds of chiral thiol compounds based on the NCS-OTPP derivatization method. Three kinds of chiral thiol compounds on a YMC Triart C18 (2.0 × 150 mm, 1.9 µm) column with Rs were 1.56-1.68. The protonated precursor to product ion transitions monitored for GSH was m/z 780.16→747.24/473.18, Cys was m/z 594.20→561.18/473.18, and Hcy was m/z 608.21→575.19/473.18. An excellent linearity for all the analytes with correlation coefficients ≥ 0.9995 and suitable precision with inter-day and intra-day coefficients of variation RSDs was 0.83-4.06% and 0.95-3.11%. Satisfactory accuracy with recoveries between 83.73 and 103.35% was observed. The limit of detection (S/N = 3) was 2.4-7.2 fmol. Furthermore, the method was successfully applied to the simultaneous determination of three kinds of free and total thiol compounds in serum from 10 healthy volunteers at normal and stress states.


Asunto(s)
Espectrometría de Masas/métodos , Estrés Psicológico/sangre , Compuestos de Sulfhidrilo/sangre , Compuestos de Sulfhidrilo/química , Adulto , Calibración , Cromatografía Líquida de Alta Presión , Femenino , Voluntarios Sanos , Humanos , Límite de Detección , Masculino , Compuestos Organofosforados/síntesis química , Compuestos Organofosforados/química , Reproducibilidad de los Resultados , Estadística como Asunto , Estereoisomerismo , Factores de Tiempo , Adulto Joven
9.
Molecules ; 26(4)2021 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-33669172

RESUMEN

Pomegranate pomace (PP) is the solid waste produced in bulk by the pomegranate juice industry which is rich in polyphenols and flavonoids that can replace the hazardous chemical antioxidants/antimicrobials currently used in the agro-food and cosmetics sectors. In the present work, the vacuum microwave assisted extraction (VMAE) of natural antioxidants from raw pomegranate pomace was investigated and successfully optimized at an industrial scale. For the optimization of PP VMAE a novel, highly accurate response surface methodology (RSM) based on a comprehensive multi-point historical design was employed. The optimization showed that the maximum recovery of PP total polyphenols as well as total PP flavonoids were obtained at microwave power = 4961.07 W, water to pomace ratio = 29.9, extraction time = 119.53 min and microwave power = 4147.76 W, water to pomace ratio = 19.32, extraction time = 63.32 min respectively. Moreover, the optimal VMAE conditions on economic grounds were determined to be: microwave power = 2048.62 W, water to pomace ratio = 23.11, extraction time = 15.04 min and microwave power = 4008.62 W, water to pomace ratio = 18.08, extraction time = 15.29 min for PP total polyphenols and PP total flavonoids respectively. The main conclusion of this study is that the VMAE extraction can be successfully used at industrial scale to produce, in economic manner, high added value natural extracts from PP pomace.


Asunto(s)
Flavonoides/aislamiento & purificación , Jugos de Frutas y Vegetales , Residuos Industriales/análisis , Microondas , Polifenoles/aislamiento & purificación , Granada (Fruta)/química , Residuos Sólidos/análisis , Vacio , Análisis de Varianza , Modelos Teóricos , Extractos Vegetales/química , Estadística como Asunto
10.
Molecules ; 26(4)2021 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-33669887

RESUMEN

In the last few years, a new term, "High-phenolic olive oil", has appeared in scientific literature and in the market. However, there is no available definition of that term regarding the concentration limits of the phenolic ingredients of olive oil. For this purpose, we performed a large-scale screening and statistical evaluation of 5764 olive oil samples from Greece coming from >30 varieties for an eleven-year period with precisely measured phenolic content by qNMR. Although there is a large variation among the different cultivars, the mean concentration of total phenolic content was 483 mg/kg. The maximum concentration recorded in Greece reached 4003 mg/kg. We also observed a statistically significant correlation of the phenolic content with the harvest period and we also identified varieties affording olive oils with higher phenolic content. In addition, we performed a study of phenolic content loss during usual storage and we found an average loss of 46% in 12 months. We propose that the term high-phenolic should be used for olive oils with phenolic content > 500 mg/kg that will be able to retain the health claim limit (250 mg/kg) for at least 12 months after bottling. The term exceptionally high phenolic olive oil should be used for olive oil with phenolic content > 1200 mg/kg (top 5%).


Asunto(s)
Espectroscopía de Resonancia Magnética , Aceite de Oliva/química , Fenoles/análisis , Estadística como Asunto , Aldehídos/análisis , Monoterpenos Ciclopentánicos/análisis , Grecia , Fenoles/química , Preservación Biológica
13.
J Chromatogr A ; 1640: 461931, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33581675

RESUMEN

The average minimum resolution required for separating adjacent single-component peaks (SCPs) in one-dimensional chromatograms is an important metric in statistical overlap theory (SOT). However, its value changes with changing chromatographic conditions in non-intuitive ways, when SOT predicts the average number of peaks (maxima). A more stable and easily understood value of resolution is obtained on making a different prediction. A general equation is derived for the sum of all separated and superposed widths of SCPs in a chromatogram. The equation is a function of the saturation α, a metric of chromatographic crowdedness, and is expressed in dimensionless form by dividing by the duration of the chromatogram. This dimensionless function, f(α), is also the cumulative distribution function of the probability of separating adjacent SCPs. Simulations based on the clustering of line segments representing SCPs verify expressions for f(α) calculated from five functions for the distribution of intervals between adjacent SCPs. Synthetic chromatograms are computed with different saturations, distributions of intervals, and distribution of SCP amplitudes. The chromatograms are analyzed by calculating the sum of the widths of peaks at different relative responses, dividing the sum by the duration of the chromatograms, and graphing the reduced sum against relative response. For small values of relative response, the reduced sum approaches the fraction of baseline that is occupied by chromatographic peaks. This fraction can be identified with f(α), if the saturation α is defined with the average minimum resolution equaling 1.5. The identification is general and is independent of the saturation, the interval distribution, or the amplitude distribution. This constant value of resolution corresponds to baseline resolution, which simplifies the interpretation of SOT.


Asunto(s)
Cromatografía/métodos , Estadística como Asunto , Simulación por Computador , Probabilidad
14.
Interdiscip Sci ; 13(1): 118-127, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33609237

RESUMEN

Gene sequencing technology has been playing an important role in many aspects, such as life science, disease medicine and health medicine, particularly in the extremely tough process of fighting against 2019-novel coronavirus. Drawing DNA restriction map is a particularly important technology in genetic biology. The simplified partial digestion method (SPDP), a biological method, has been widely used to cut DNA molecules into DNA fragments and obtain the biological information of each fragment. In this work, we propose an algorithm based on 0-1 planning for the location of restriction sites on a DNA molecule, which is able to solve the problem of DNA fragment reconstruction just based on data of fragments' length. Two specific examples are presented in detail. Furthermore, based on 1000 groups of original DNA sequences randomly generated, we define the coincidence rate and unique coincidence rate between the reconstructed DNA sequence and the original DNA sequence, and then analyze separately the effect of the number of fragments and the maximum length of DNA fragments on the coincidence rate and unique coincidence rate as defined. The effectiveness of the algorithm is proved. Besides, based on the existing optimization solution obtained, we simulate and discuss the influence of the error by computation method. It turns out that the error of position of one restriction site does not affect other restriction sites and errors of most restriction sites may lead to the failure of sequence reconstruction. Matlab 7.1 program is used to solve feasible solutions of the location of restriction sites, derive DNA fragment sequence and carry out the statistical analysis and error analysis. This paper focuses on basic computer algorithm implementation of rearrangement and sequencing rather than biochemical technology. The innovative application of the mathematical idea of 0-1 planning to DNA sequence mapping construction, to a certain extent, greatly simplifies the difficulty and complexity of calculation and accelerates the process of 'jigsaw' of DNA fragments.


Asunto(s)
Algoritmos , Análisis de Secuencia de ADN , Secuencia de Bases , Modelos Teóricos , Estadística como Asunto
17.
Nurs Outlook ; 69(2): 228-233, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33509626

RESUMEN

Statistics knowledge is essential for nursing faculty in both teaching and research roles. In the teaching role when discussing nursing research, nursing faculty are confronted with statistical concepts and statistical methods applications. Knowledge of fundamental statistical concepts is needed so that nursing faculty can understand and critically evaluate the literature. The purpose of this study was to assess nursing faculty knowledge of fundamental statistical concepts. A probability sample with a 7.7% response rate yielded participation from 164 nursing faculty from 26 accredited schools. Results showed that most faculty members (91.5%) read peer-reviewed health-related scientific journal articles. On average, nursing faculty answered 5.1 (SD = 1.6) out of 8 statistical knowledge questions correctly. Problematic concepts included randomization (43.3% correct), and interpreting a confidence interval (42.7%) and odds ratio (33.5%). The results of this study may be used to improve statistics education and training for future nursing faculty and strengthen scholarship for nursing faculty conducting research.


Asunto(s)
Educación de Postgrado en Enfermería/normas , Docentes de Enfermería/normas , Competencia Profesional/normas , Estadística como Asunto/normas , Estudios Transversales , Educación de Postgrado en Enfermería/estadística & datos numéricos , Docentes de Enfermería/estadística & datos numéricos , Humanos , Competencia Profesional/estadística & datos numéricos , Instituciones Académicas/organización & administración , Instituciones Académicas/estadística & datos numéricos , Encuestas y Cuestionarios
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