Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Medicine (Baltimore) ; 102(27): e34274, 2023 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-37417603

RESUMEN

A microbial ecosystem is a complex community of multiple bacterial interactions. The potential role of gut microbiota in human health has already attracted the attention of many researchers. Dysregulation of the gut microbial community has been suggested to be closely associated with the progression of various chronic diseases. Malignant neoplasms represent a major global health burden and are now the leading cause of death. The formation of tumors is often thought to be influenced by genetic and environmental factors. Recent research advances have indicated that multiple malignancies may also be attributed to the gut microbiota. In this review, we highlight the complex interactions between gut microbes and their metabolites, as well as the potential impact of gut microecology on the occurrence and development of tumors. In addition, potential strategies for targeted therapy of tumors using gut microecology are discussed. In the near future, intestinal microecology is likely to be used for early screening of tumors and subsequent clinical treatment.


Asunto(s)
Microbioma Gastrointestinal , Microbiota , Neoplasias , Humanos , Neoplasias/terapia , Microbioma Gastrointestinal/fisiología , Bacterias/metabolismo
2.
Sci Adv ; 9(1): eabq5273, 2023 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-36608124

RESUMEN

Mastering nuclear fusion, which is an abundant, safe, and environmentally competitive energy, is a great challenge for humanity. Tokamak represents one of the most promising paths toward controlled fusion. Obtaining a high-performance, steady-state, and long-pulse plasma regime remains a critical issue. Recently, a big breakthrough in steady-state operation was made on the Experimental Advanced Superconducting Tokamak (EAST). A steady-state plasma with a world-record pulse length of 1056 s was obtained, where the density and the divertor peak heat flux were well controlled, with no core impurity accumulation, and a new high-confinement and self-organizing regime (Super I-mode = I-mode + e-ITB) was discovered and demonstrated. These achievements contribute to the integration of fusion plasma technology and physics, which is essential to operate next-step devices.

3.
Environ Monit Assess ; 193(8): 486, 2021 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-34245364

RESUMEN

Particulate matter (PM) is the primary air pollutant in northern China. The PM2.5/PM10 ratio has been used increasingly as an indicator to reflect anthropogenic PM pollution, but its advantages compared with individual PM2.5 or PM10 concentrations have not been proven sufficiently by experimental data. By dividing Hebei Province (China) into seven natural ecological regions, this study investigated the spatial characteristics of the PM2.5/PM10 ratio and its relationships with PM2.5, PM10, economic density, and wind speed. Results showed that the PM2.5/PM10 ratio decreased from east to west and from south to north, with an annual average value in 2019 of 0.439-0.559. The characteristics of the spatial variation of the PM2.5/PM10 ratio were different to those of either PM2.5 or PM10 concentration, indicating that PM pollution reflected by the PM2.5/PM10 ratio is not entirely consistent with that by PM2.5 and PM10 concentrations. In comparison with PM2.5 or PM10 concentration, the PM2.5/PM10 ratio had higher (lower) correlation with economic density (wind speed), indicating that the PM2.5/PM10 ratio is a better indicator used to reflect the intensity of anthropogenic emissions of PM pollutants. According to the characteristics of the spatial variations of the PM2.5/PM10 ratio and the PM2.5 and PM10 concentrations, the seven ecological regions of Hebei Province were categorized into four different types of atmospheric PM pollution: "three low regions," "three high regions," "one high and two low regions," and "one low and two high regions." This reflects the comprehensive effect of the intensity of anthropogenic PM emissions and the atmospheric diffusion conditions.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , China , Monitoreo del Ambiente , Material Particulado/análisis , Estaciones del Año
4.
Nan Fang Yi Ke Da Xue Xue Bao ; 39(10): 1160-1165, 2019 Oct 30.
Artículo en Chino | MEDLINE | ID: mdl-31801715

RESUMEN

OBJECTIVE: To observe the effect of occlusal interference on the afferent pathway of the trigeminal nerve and neuronal excitability in the trigeminal subnucleus caudalis (SPVC) of rats by electrical stimulation of the trigeminal ganglion (TG) and extracellular recordings of SPVC activities. METHODS: Twenty male Wistar rats were randomly divided into control group and model group (n=10). In the model group, occlusal interference for 30 consecutive days was induced using light-cured flowable resin on the right maxillary molars. During occlusal interference, the pain sensitivity was scored with von Frey Fibers in the masseter. Simultaneous recordings of electrical activities from the SPVC, electrocardiogram, body temperature and electromyogram of the breath muscles of the anesthetized rats were performed, and the responses evoked by electrical stimulation of the TG were analyzed. RESULTS: Compared with the control rats, the rats in the model group showed significantly increased pain sensitivity scores (P < 0.05) and increased spontaneous discharge frequency of the SPVC (P < 0.05). The amplitude of the SPVC responses induced by electrical stimulation of the TG showed stimulus intensity-dependent changes (P < 0.05), and the amplitude evoked by 4 mA and 8 mA stimulation was similar between the model group and the control group (P>0.05). Train stimulation (0.2 ms, 1 mA, 30 s, 100 Hz) of the TG significantly increased the discharge frequency of the SPVC only in the rats in the model group (P < 0.05). CONCLUSIONS: The functional activities of the pain afferent pathway of the trigeminal nerve can be electrophysiologically monitored by electrical stimulation of the TG and extracellular recordings of SPVC activities in rats. Occlusal interference can increase the excitability of the neurons in the SPVC and enhance their sensitivities to TG afferent activation, suggesting the neural plasticity of the pain afferent pathway.


Asunto(s)
Vías Aferentes , Dimensión del Dolor , Umbral del Dolor , Dolor/fisiopatología , Nervio Trigémino/fisiología , Animales , Masculino , Distribución Aleatoria , Ratas , Ratas Wistar , Núcleos del Trigémino
5.
Sci Total Environ ; 697: 133850, 2019 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-31491626

RESUMEN

Pharmaceuticals and personal care products (PPCPs) in reclaimed water can enter into soil, groundwater, and air during the irrigation of urban green spaces, leading to potential risks due to their negative effects of feminization, on root elongation, and as carcinogens. In this study, a validated HYDRUS-1D model by field experiments and an exposure model were used to simulate the distributions of 67 PPCPs detected in the effluent from municipal wastewater treatment plants of Beijing under two scenarios (1, uniform irrigation concentrations; 2, detected irrigation concentrations) in soil, groundwater, and air. To determine the priority ranks of the 67 PPCPs, the effect values of the PPCPs in soil, groundwater, and air were calculated on the basis of distributions and toxicity data, and then weighted and scored. Under scenario 1, roxithromycin, medroxyprogesterone acetate, and megestrol acetate, characterized by high adsorption and low volatilization and degradation, had the highest accumulations in soil, and ofloxacin, characterized by the lowest degradation and adsorption, had the highest leaching to groundwater. The highest volatilization was observed for galaxolide abbalide, tonalid, and dioctyl phthalate. Under scenario 2, based on their overall scores and priority ranks, the 67 PPCPs were divided into three groups: I, high priority; II, moderate priority; III, low priority. Of the 67 PPCPs, 17 were classified in group I, with the highest priority rankings for ofloxacin, 17α-ethynylestradiol, dibutyl phthalate, dioctyl phthalate, and sulfamethoxazole. In group III (total 33 PPCPs), 28 of the PPCPs were not of urgent concern under reclaimed water irrigation in Beijing.


Asunto(s)
Cosméticos/análisis , Monitoreo del Ambiente , Preparaciones Farmacéuticas/análisis , Contaminantes Químicos del Agua/análisis , Riego Agrícola , Beijing , Aguas Residuales
6.
Ying Yong Sheng Tai Xue Bao ; 27(1): 73-82, 2016 Jan.
Artículo en Chino | MEDLINE | ID: mdl-27228595

RESUMEN

Soil erosion is an important ecological and environmental problem in Hunshandake Desert, and the sand-fixing function determines the degree of ecological security in the entire region. In order to clarify the situation of windbreak and sand fixation in Hunshandake area, and to guide the prevention and treatment of desertification on regional scale, based on the meteorological and remote sensing data, this paper quantitatively analyzed the temporal and spatial pattern of windbreak and sand fixation ability between 2000-2010 by the revised wind erosion equation (RWEQ) model, meanwhile, the driving forces for each county ( or banner) in the functional zone were analyzed with the method of principal component analysis. The results showed that there was a fluctuation of the sand fixing capacity in Hunshandake over time, generally rendering a decline trend. The coniferous forest and grassland had strong windbreak and sand fixation capacity in unit area among the various land categories. In terms of spatial distribution, the windbreak and sand fixation function in western and southeastern region was weak and needed to be strengthened with ecological restoration efforts. Through the study of the social driving forces of each administrative region in the function zone, there were 3 main social driving forces of soil erosion in the administrative functions: the intensity of input-output, the level of economic development and the level of agriculture-husbandry development.


Asunto(s)
Conservación de los Recursos Naturales , Clima Desértico , Suelo , China , Bosques , Pradera , Dióxido de Silicio , Análisis Espacio-Temporal , Viento
7.
Phys Rev Lett ; 106(23): 235001, 2011 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-21770511

RESUMEN

Lower-hybrid waves have been shown to induce a cocurrent change in toroidal rotation of up to 40 km/s in the L-mode plasma core region and 20 km/s in the edge of the EAST tokamak. This modification of toroidal rotation develops on different time scales. For the edge, the time scale is no more than 100 ms, but for the core the time scale is around 1 s. A simple model based on turbulent equipartition and thermoelectric pinch predicts the experimental results.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...