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BACKGROUND: 14C urea breath test (14C UBT) and immunohistochemical staining (IHC) are widely used for detection Helicobacter pylori (H. pylori) infection with different sensitivity, and there is a difference in H. pylori infection rate in Uyghur and Han ethnic groups. Both need large cohort studies to evaluate the differences more accurately. AIM: To analyze the difference between 14C UBT and IHC for H. pylori detection in Xinjiang Uyghur Autonomous Region and the difference between Uyghur and Han populations. METHODS: There were 3944 cases of H. pylori infection detected by both IHC and 14C UBT at the same time (interval < 1 wk, with sampling site including gastric antrum, selected from 5747 patients). We compared the sensitivity of 14C UBT and IHC. We also compared 555 pairs of Han/Uyghur cases (completely matched for gender and age) for their H. pylori infection rates. The overall H. pylori infection rate of all 5747 cases and the correlation with other clinicopathological data were also further analyzed. SPSS V23.0 software was used for statistical analysis. RESULTS: The sensitivity was 94.9% for 14C UBT and 65.1% for IHC, which was a significant difference (n = 3944, P < 0.001). However, among those cases negative for H. pylori by 14C UBT (detection value ≤ 100), 4.8% were positive by IHC. Combining both methods, the overall H. pylori infection rate was 48.6% (n = 5747), and differences in gender, age group, ethnicity and region of residence significantly affected the H. pylori positive rates. According to age group (Han/Uyghur), the positive rates were ≤ 30 years (62.2%/100.0%), 31-40 years (45.2%/85.7%), 41-50 years (47.2%/79.2%), 51-60 years (44.6%/76.1%), 61-70 years (40.9%/68.2%), 71-80 years (41.7%/54.1%) and ≥ 81 years (42.9%/NA). The H. pylori infection rates of Han/Uyghur paired cases were 41.4% and 73.3%, which was a significant difference (P < 0.001) (555 pairs). H. pylori positivity was significantly related to moderate-severe grade 2-3 chronic/active gastritis and intestinal metaplasia (all P < 0.05). CONCLUSION: The sensitivity of 14C UBT was significantly higher, but combined application can still increase the accuracy. The prevention H. pylori should be emphasized for Uygur and young people.
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Gastritis Atrófica , Gastritis , Infecciones por Helicobacter , Helicobacter pylori , Humanos , Adolescente , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/epidemiología , Infecciones por Helicobacter/patología , Prevalencia , Pruebas Respiratorias/métodos , Urea/análisis , Sensibilidad y EspecificidadRESUMEN
This study proposed a method for constructing a low impact development (LID) plan to improve the utilization rate of rainwater in a highway service area and solve the problem of waterlogging. Firstly, based on the theory of LID, taking the total runoff as the control goal, and combining it with the functional zoning of the highway service area and the characteristics of LID facilities, several LID schemes were proposed. Then, the evaluation system of the LID scheme in service area was established by the analytic hierarchy process (AHP). These preliminary construction schemes were compared from three aspects (runoff control efficiency, economic efficiency and social efficiency) to determine the best LID plan. Finally, taking the Pu'er tunnel service area as an example, the construction scheme of the sponge city service area was optimized.
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Planificación de Ciudades , Lluvia , China , CiudadesRESUMEN
Understory vegetation is an important component in most forest ecosystems. It is very important for soil and water conservation in karst region, study on understory will provide valuable information for understanding the interaction mechanism between understory flora and karst environment. Thirty-two plots were sampled in three vegetation types along with a restoration gradient (shrubland, forest-shrub transition, and mixed-species broadleaf forest) in typical karst mountains in Southwest Guangxi, China. Overstory trees, understory vascular plants, soil nutrients, and topographic factors were recorded in each 400-m2 plot. Multivariate statistics were used, including the multi-response permutation procedure (MRPP), indicator species analysis, and canonical correlation analysis (CCA). MRPP showed understory species composition significantly differed among the three vegetation types, with the greatest difference between the shrubland and the mixed forest. Twenty-one understory species were identified as significant indicator species, with 13 species being identified as indicators of the shrubland, two of forest-shrub transition, and six of the mixed forest. Light-demanding herbaceous seed plants were common in shrubland, while shade-tolerant calcicole assembled under the mixed forest. Forward selection of CCA ordination revealed that understory plant distribution was most strongly influenced by elevation, followed by soil pH, the concentration of total potassium and exchangeable calcium, slope aspect, slope degree, and the concentration of available potassium. The result reveals that vegetation types affect understory species composition by modifying understory environments. Elevation affects the spatial distribution of vegetation and soil factors, and then the understory plants. Meanwhile, soil Ca content also plays a key role in the understory species distribution. Understory diversity increased with increasing canopy structure complexity from shrubland to mixed-species forest. Thus, it is necessary to take measures to promote natural vegetation restoration and to protect the mixed forests in degraded karst areas.
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Bosques , Árboles , Biodiversidad , Calcio , China , Concentración de Iones de Hidrógeno , Análisis Multivariante , Potasio , Suelo/químicaRESUMEN
In this manuscript, using a novel wide-view visual presentation system that we developed for vision research and functional magnetic resonance imaging (fMRI), we studied contrast response functions in regions of the brain that are central and peripheral to the entire set of visual areas (V1, V2, V3, V3A, MT+), regions that have not been all investigated in previous vision research. Under the stimulus conditions which were 0-20 deg, 20-40 deg, and 40-60 deg eccentricity black-and-white checkerboard patterns, we measured the blood oxygenation level-dependent fMRI contrast response at five contrast levels (6, 12, 24, 48, and 96%) in the visual areas. On the basis of these data, the central and pericentral visual areas had low-contrast gain, whereas the peripheral visual areas had high-contrast gain. In addition, our results showed that the signals fundamentally shift during visual processing through posterior visual cortical areas (V1, V2, and V3) to superior visual cortical areas (V3A and MT+).
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Mapeo Encefálico/métodos , Sensibilidad de Contraste/fisiología , Corteza Visual/fisiología , Percepción Visual/fisiología , Adulto , Mapeo Encefálico/instrumentación , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Percepción de Movimiento/fisiología , Reconocimiento Visual de Modelos/fisiología , Visión Monocular/fisiología , Campos Visuales/fisiología , Adulto JovenRESUMEN
In the neural science society, multi-subject brain decoding is of great interest. However, due to the variability of activation patterns across brains, it is difficult to build an effective decoder using fMRI samples pooled from different subjects. In this paper, a hierarchical model is proposed to extract robust features for decoding. With feature selection for each subject treated as a separate task, a novel multi-task feature selection method is introduced. This method utilizes both complementary information among subjects and local correlation between brain areas within a subject. Finally, using fMRI samples pooled from all subjects, a linear support vector machine (SVM) classifier is trained to predict 2-D stimuli-related images or 3-D stimuli-related images. The experimental results demonstrated the effectiveness of the proposed method.
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Mapeo Encefálico/métodos , Encéfalo/fisiología , Potenciales Evocados Visuales/fisiología , Imagen por Resonancia Magnética/métodos , Red Nerviosa/fisiología , Reconocimiento de Normas Patrones Automatizadas/métodos , Análisis y Desempeño de Tareas , Algoritmos , Humanos , Interpretación de Imagen Asistida por Computador/métodos , Imagenología Tridimensional/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Máquina de Vectores de SoporteRESUMEN
The objective study was to estimate the rheological properties and physiological compatibility of the blood pump by simulating the internal flow field of the blood pump. In this study we use computational fluid dynamics method to simulate and analyse two models of axial blood pumps with a three-blade diffuser and a six-blade diffuser, named pump I and pump II, respectively, and to compare the flow patterns of these two kinds of blood pumps while both of them satisfy the conditions of the normal human blood differential pressure and blood flow. Results indicate that (i) the high shear force occurs between the diffuser and the rotor in which the crucial place leads to haemolysis and (ii) under the condition of 100 mmHg pressure head and 5 l/min flow rate, the difference between the two kinds of blood pumps, as far as the haemolytic performance is concerned, is notable. The haemolysis index of the two pumps is 0.32% and 0.2%. In conclusion, the performance of the blood pump is influenced by the diffusers' blade number. Pump II performed better than pump I, which can be the basic model for blood pump option.
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Corazón Auxiliar , Modelos Cardiovasculares , Simulación por Computador , Hemodinámica , Hemólisis , Hidrodinámica , ReologíaRESUMEN
Ultrasound as a noninvasive imaging technique is widely used to diagnose liver diseases. Texture analysis and classification of ultrasound liver images have become an important research topic across the world. In this study, GLGCM (Gray Level Gradient Co-Occurrence Matrix) was implemented for texture analysis of ultrasound liver images first, followed by the use of GLCM (Gray Level Co-occurrence Matrix) at the second stage. Twenty two features were obtained using the two methods, and seven most powerful features were selected for classification using BP (Back Propagation) neural network. Fibrosis was divided into five stages (S0-S4) in this study. The classification accuracies of S0-S4 were 100%, 90%, 70%, 90% and 100%, respectively.
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Procesamiento de Imagen Asistido por Computador , Hepatopatías/diagnóstico por imagen , Hígado/diagnóstico por imagen , Adulto , Vasos Sanguíneos/patología , Humanos , Hígado/patología , Cirrosis Hepática/patología , Redes Neurales de la Computación , Reproducibilidad de los Resultados , Propiedades de Superficie , UltrasonografíaRESUMEN
A new nonlinear approach is presented for high-frequency electrocorticography (ECoG)-based diagnosis of epilepsy. The ECoG data from 3 patients with epilepsy are analyzed in this study. A recently developed algorithm in graph theory, visibility graph (VG), is applied in this research. The approach is based on the key discovery that high-frequency oscillation takes place during epileptic seizure, making it a marker of epilepsy. Therefore, the nonlinear property of the high-frequency signal may be more noticeable. Hence, a complexity measure, called graph index complexity (GIC), is computed using the VG of the patients' high-frequency ECoG subband. After comparison and statistical analysis, the nonlinear feature is proved to be effective in detection and location of the epilepsy. Two different traditional complexities, sample entropy and Lempel-Ziv, were also calculated to make a comparison and prove that GIC provides better identification.
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Electroencefalografía/métodos , Epilepsia/diagnóstico , Algoritmos , Mapeo Encefálico , Diagnóstico Diferencial , Epilepsia/fisiopatología , Humanos , Procesamiento de Señales Asistido por ComputadorRESUMEN
A field survey was conducted in the karst mountainous region in Pingguo County of Southwest Guangxi, China to explore the structural characteristics, spatial distribution pattern, and growth dynamics of young Excentrodendron hsienmu as well as the main environmental factors affecting the natural regeneration of the E. hsienmu population. In the study area, the population structure of the young E. hsienmu was stable, and exhibited a clumped spatial pattern for the seedlings and seedling sprouts. The ground diameter growth and height growth of the young E. hsienmu presented the same variation trend, i. e., the ground diameter increased with increasing height. The ground diameter growth and height growth of the E. hsienmu seedlings were limited by population density, i. e., decreased with increasing population density. The correlation analysis showed that the trees more than 2.5 m in height and the shrubs were the major stand factors affecting the natural regeneration of young E. hsienmu, while the herbs had no significant correlation with the regeneration. The percentage of covered rock also had no significant effects on the regeneration. Kruskal-Wallis ANOVA showed that there existed significant differences in the height and ground diameter of young E. hsienmu at different slope degrees and slope positions. The population density, height, and ground diameter had significant differences across slope aspects. The natural regeneration of young E. hsienmu was comprehensively affected by the species biological characteristics, intraspecific competition, interspecific competition, heterogeneous habitat, and anthropogenic disturbances.
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Conservación de los Recursos Naturales , Ecosistema , Plantones/crecimiento & desarrollo , Árboles/crecimiento & desarrollo , Altitud , China , Eucalyptus/crecimiento & desarrollo , Agricultura Forestal/métodos , Pinus/crecimiento & desarrollo , Dinámica PoblacionalRESUMEN
Difficulties in realizing persistent neurogenesis, inabilities in modeling pathogenesis of most cases, and a shortage of disease material for screening therapeutic agents restrict our progress to overcome challenges presented by neurodegenerative diseases. We propose that reprogramming primary somatic cells of patients into induced pluripotent stem cells (iPSCs) provides a new avenue to overcome these impediments. Their abilities in self-renewal and differentiation into various cell types will enable disease investigation and drug development. In this review, we introduce efficient approaches to generate iPSCs and distinct iPSCs differentiation stages, and critically discuss paradigms of iPSCs technology application to investigate neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). Although iPSCs technology is in its infancy and faces many obstacles, it has great potential in helping to identify therapeutic targets for treating neurodegenerative diseases.
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Diferenciación Celular/fisiología , Células Madre Pluripotentes Inducidas/fisiología , Enfermedades Neurodegenerativas/cirugía , Trasplante de Células Madre/tendencias , Animales , Humanos , Enfermedades Neurodegenerativas/patología , Trasplante de Células Madre/métodos , Resultado del TratamientoRESUMEN
As a suddenly abnormal discharge of brain neurons, epilepsy can lead to encephalographic (EEG) abnormalities. Data of 3 epileptic patients recorded by depth intracranial electrodes are analyzed with time-frequency algorithms to observe the abnormal changes in different frequency ranges. Comparing the frequency domain of the normal and epileptic signals that contain several periods of clinical seizures and intervals, a remarkable range of high frequency is identified and corresponds to the seizure. According to the corresponding position of those channels that produced abnormal signals, the epileptic focus is determined theoretically and verified by comparison with the clinical diagnosis and surgical results. Furthermore, the order of the presence of different frequency ranges is listed. The finding proposed in this study could be a fresh method to improve the diagnosis of epilepsy.
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Algoritmos , Electroencefalografía/métodos , Epilepsia del Lóbulo Temporal/diagnóstico , Epilepsia del Lóbulo Temporal/fisiopatología , Modelos Neurológicos , Mapeo Encefálico/métodos , Electrodos Implantados , Humanos , Sensibilidad y EspecificidadRESUMEN
A hidden Markov model (HMM) of electrocardiogram (ECG) signal is presented for detection of myocardial ischemia. The time domain signals that are recorded by the ECG before and during the episode of local ischemia were pre-processed to produce input sequences, which is needed for the model training. The model is also verified by test data, and the results show that the models have certain function for the detection of myocardial ischemia. The algorithm based on HMM provides a possible approach for the timely, rapid and automatic diagnosis of myocardial ischemia, and also can be used in portable medical diagnostic equipment in the future.
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Algoritmos , Inteligencia Artificial , Diagnóstico por Computador/métodos , Electrocardiografía/métodos , Isquemia Miocárdica/diagnóstico , Reconocimiento de Normas Patrones Automatizadas/métodos , Humanos , Cadenas de Markov , Modelos Cardiovasculares , Modelos Estadísticos , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
An ejection dynamics mathematical model of human left ventricle (LV) based on physiological data of human heart is proposed in this study. The mathematical equations were expressed in terms of vorticity-stream function equations in a prolate spheroidal coordinate system. These equations combined with specified boundary conditions were numerically solved by using an alternating-direction-implicit (ADI) algorithm with second order accuracy. The unsteady aspects of the ejection process were subsequently introduced into the numerical simulation. The numerical results have shown that the present ellipsoidal model could be available to simulate the ejection process of the human LV. Such a model combined with cardiac muscle mechanics could be studied further to determine altered left ventricular function in cardiac diseases.