锁骨朗格汉斯组织细胞增生症的影像诊断及鉴别          下载免费PDF全文

李明球  杜钢  彭加友  方挺松  张家雄 《CT理论与应用研究》2021,30(4):533-538

目的:总结锁骨朗格汉斯组织细胞增生症（LCH）的影像表现。材料与方法:收集2005年7月至2018年12月9例（男女比4︰5,平均年龄10.5岁）手术病理证实的锁骨LCH的术前X线、CT、MRI资料进行回顾性分析。结果:有4例位于锁骨中段,2例位于锁骨外1/3段,3例位于锁骨内1/3段或中内2/3段。6例表现为纯溶骨性骨质破坏,骨皮质断裂,破坏区边缘见反应性骨质增生及层状骨痂;1例表现为虫蚀状骨质破坏,病灶膨胀不明显,边界模糊。2例病灶膨胀性生长,其内见多发骨间隔,骨包壳完整,周围无软组织肿块。4例病灶在T₁WI上呈不均匀低信号,T₂WI上呈不均匀高信号,增强扫描中度不均匀强化。结论:锁骨LCH好发于儿童,不同分期和锁骨的不同部位影像表现均不同,需和尤文肉瘤、慢性骨髓炎、浆细胞骨髓瘤等疾病鉴别。   相似文献   

A methodological approach of fluvial dynamics oriented towards hydrosystem management: case study of the Loire and Allier rivers     

Emmanuèle Gautier  Hervé Piégay  Patrick Bertaina 《Geodinamica Acta》2013,26(1):29-43

Abstract

This study was conducted as part of the European LIFE Loire Nature program for the conservation and management of a 110-km-long section of the Loire and Allier rivers, an area renowned for its ecological richness. The methodological approach is based on statistical analysis (bivariate and multivariate analyses) of hydro-geomorphologic and biogeographical variables, complemented by reach typology and mapping. The main results show, on the one hand, the great spatial variability of fluvial mosaic complexity along the river continuum and on the other hand, some independence between the riparian forest characteristics and the channel forms. The fluvial pattern (e.g. anabranching) and the forest establishment along the Loire river register specific features. © 2000 Éditions scientifiques et médicales Elsevier SAS  相似文献   

Longitudinal and temporal thermal patterns of the French Rh?ne River using Landsat ETM+ thermal infrared images     

Vincent Wawrzyniak  Hervé Piégay  Alain Poirel 《Aquatic Sciences - Research Across Boundaries》2012,74(3):405-414

Understanding the thermal regime of rivers is a key issue for predicting ecosystem change in the context of global warming. However, water temperature is not only influenced by air temperature. To better highlight relative contribution of factors controlling water temperature, we used satellite thermal infrared (TIR) images from Landsat ETM+ to investigate longitudinal and temporal variations in thermal patterns of the French Rh?ne River. Because satellite TIR remote sensing is limited to large rivers, we used an automated water extraction technique to remove pixels contaminated by terrestrial surfaces. We calculated water surface temperatures of the 500?km long reach for 83 dates between 1999 and 2009. The average accuracy and uncertainty of our data, ±1.1 and ±0.4°C for reaches with more than 3?pixels across and ±1.4 and ±0.5°C for reaches with one to 3?pixels across, are comparable to other satellite TIR studies of rivers. Our results confirmed previous studies on the thermal impacts of tributaries and nuclear power plants on the Rh?ne, providing an understanding of their seasonal pattern and their longitudinal impact. We showed temperature differences of 0?C2°C within the largest hydroelectric bypass facilities between the bypass section and the canal, with Montélimar and Caderousse showing the most pronounced differences. Discussion points concern the potential impacts of tributaries and nuclear power plants on the spatio-temporal thermal patterns, as well as the factors responsible for thermal differences in the bypass facilities: length and minimum flow of the bypass section, and tributaries coming into this reach.  相似文献   

Adsorption of Phosphate by Biomass Char Deriving from Fast Pyrolysis of Biomass Waste     

Feng Peng  Pi‐Wen He  Yin Luo  Xiang Lu  Ying Liang  Jie Fu 《洁净——土壤、空气、水》2012,40(5):493-498

Biomass char (BC) deriving from fast pyrolysis of biomass was a potential adsorption material due to its relative high fixed‐carbon content and the inherent porous structures. Adsorption of phosphate from aqueous solution by BC was investigated in this paper. The results showed that the adsorption capacity of BC was dependent on pyrolysis conditions, such as temperature and holding time. The maximum adsorption capacity for phosphate was approximately 15.11 mg g^?1 at 298 K. The pseudo‐second order model of the adsorption kinetics indicated that the adsorption process was complex and several mechanisms were involved. Equilibrium isotherm was satisfactorily followed the Freundlich isotherm model. The K_F value in Freundlich equation gradually increased with elevating temperature. Moreover, the thermodynamic constants: ΔG⁰, ΔH⁰, and ΔS⁰ were evaluated as ?6.49 kJ mol^?1 (at 298 K), 13.41 kJ mol^?1, and 66.70 J mol^?1 K^?1, respectively. Phosphate adsorption onto BC was spontaneous and endothermic. As a waste, BC was a potentially attractive adsorbent for phosphate removal from aqueous solution with low cost and high capability.  相似文献   

Hydromorphological frameworks: emerging trajectories     

A. M. Gurnell  M. Rinaldi  A. D. Buijse  G. Brierley  H. Piégay 《Aquatic Sciences - Research Across Boundaries》2016,78(1):135-138

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南海北部陆缘三水盆地CO₂成因及运聚成藏规律与主控因素     

吴炜强  何家雄  祝有海  黄霞  龚晓峰 《海洋地质与第四纪地质》2012,(5):89-96

三水盆地二氧化碳依据其地质地球化学特征判识,主要属火山幔源型成因类型,亦有灰岩热蚀变壳源型及少量壳幔混合型成因类型。二氧化碳气源供给主要来自火山幔源活动之原始岩浆脱排气作用,但灰岩受火成岩热蚀变所产出的二氧化碳为其重要补充。火山幔源型二氧化碳气藏形成及分布,主要取决于火山幔源脱排气活动、深大断裂导气输送作用及有效圈闭三者相互间的时空配置,并受控于气源供给系统(气源构成与输导格架)和运聚成藏之圈闭聚集系统(储盖组合及有效圈闭)这两大主控因素之制约。基于该区火山幔源型和灰岩热蚀变壳源型二氧化碳成因及气源构成特点与运聚富集规律,即可评价预测这些不同成因二氧化碳的有利富集区带及资源潜力,进而为油气勘探部署决策及综合利用等提供指导和借鉴。  相似文献   

Implementation and validation of video monitoring for wood budgeting in a wandering piedmont river,the Ain River (France)     

Bruce MacVicar  Hervé Piégay 《地球表面变化过程与地形》2012,37(12):1272-1289

The transport of wood in rivers during floods is an important process that underlies differences in habitat and morphology between water courses and regions. Quantitative data are needed to properly address management objectives and balance wood budgets. In this study we use a streamside video camera to detect wood passage and measure quasi‐instantaneous rates of wood transport in the Ain River, France. The objectives are to verify the procedure, describe the relation between wood transport and discharge, and construct and validate a wood budget for the reach upstream of the camera. Verification of the procedure includes tests of detection frequency, wood velocity, and piece size. A log base two transformation is proposed to classify wood by piece length. It was found that a wood transport threshold occurs at approximately two thirds of the bankfull discharge. Wood transport follows a positive linear relation with discharge up to the bankfull discharge but is both more variable and less sensitive to discharge when the floodplain is inundated. Transport rates are approximately four times higher on the rising limb of the hydrograph than on the falling limb. Wood transport estimates from a three‐stage rating curve are two to 10 times higher than those from a wood budget using local and aerial surveys of upstream dynamics. Future work should address uncertainties related to wood diameter measurements, sampling length and frequency, and antecedent floods. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Mixed heavy metals tolerance and radial oxygen loss in mangrove seedlings   总被引：2，自引：0，他引：2  

Y. Liu  N.F.Y. Tam  J.X. Yang  N. Pi  M.H. Wong  Z.H. Ye 《Marine pollution bulletin》2009,(12):1843-1849

The effects of a mixture of heavy metals (Pb, Zn and Cu) on growth, radial oxygen loss (ROL) and the spatial pattern of ROL were investigated in mangrove seedlings of three species: Aegiceras corniculatum, Avicennia marina and Bruguiera gymnorrhiza. Heavy metals inhibited the growth of seedlings and led to decreased ROL and changes in the “tight” barrier spatial pattern of ROL. There was a significant positive correlation between the amount of ROL from the roots of seedlings and metal tolerance. The species with the highest ROL amount, B. gymnorrhiza, were also the most tolerant to heavy metals. The “tight” barrier spatial ROL pattern was also related to metal tolerance in the seedlings. Therefore, we conclude that both ROL amount and “tight” barrier spatial ROL pattern in the roots of the mangrove seedlings play an important role in resistance to heavy metal toxicity.  相似文献   

Management alternatives to offset climate change effects on Mediterranean fire regimes in NE Spain   总被引：1，自引：0，他引：1  

Lasse Loepfe  Jordi Martinez-Vilalta  Josep Pi?ol 《Climatic change》2012,115(3-4):693-707

Fire regime is affected by climate and human settlements. In the Mediterranean, the predicted climate change is likely to exacerbate fire prone weather conditions, but the mid- to long-term impact of climate change on fire regime is not easily predictable. A negative feedback via fuel reduction, for instance, might cause a non-linear response of burned area to fire weather. Also, the number of fires escaping initial control could grow dramatically if the fire meteorology is just slightly more severe than what fire brigades are prepared for. Humans can directly influence fire regimes through ignition frequency, fire suppression and land use management. Here we use the fire regime model FIRE LADY to assess the impacts of climate change and local management options on number of fires, burned area, fraction of area burned in large fires and forest area during the twenty-first century in three regions of NE Spain. Our results show that currently fuel-humidity limited regions could suffer a drastic shift of fire regime with an up to 8 fold increase of annual burned area, due to a combination of fuel accumulation and severe fire weather, which would result in a period of unusually large fires. The impact of climate change on fire regime is predicted to be less pronounced in drier areas, with a gradual increase of burned area. Local fire prevention strategies could reduce but not totally offset climate induced changes in fire regimes. According to our model, a combination of restoring the traditional rural mosaic and classical fire prevention would be the most effective strategy, as a lower ignition frequency reduces the number of fires and the creation of agricultural fields in marginal areas reduces their extent.  相似文献   

Heavy metal pollution in the soil surrounding a thermal power plant in Playas de Rosarito,Mexico     

M. A. Pastrana-Corral  F. T. Wakida  J. Temores-Peña  D. D. Rodriguez-Mendivil  E. García-Flores  T. D. J. Piñon-Colin  A. Quiñonez-Plaza 《Environmental Earth Sciences》2017,76(16):583

The generation of electricity has been identified as one of the main pollutant activities, and some studies have established an increment of heavy metals in soil in the areas surrounding these plants. The aim of this study was to evaluate the soil concentrations of heavy metals in the zone surrounding a thermoelectric power in Mexico. Thirty-two top soil samples (0–5 cm) were collected; additionally, four depth profiles (1 m) were investigated. Median concentrations for chromium, vanadium, nickel, mercury, and cadmium were 47, 47, 73, 0.02, and 0.01 mg/kg, respectively. Higher Cr, Ni, and V concentrations were observed in the soil depth profiles located closer to the plant in comparison with the concentrations found in the soil depth profile located further away from the plant; these results may indicate a possible accumulation of these metals. The geoaccumulation index results indicated that most of the sites were in the classifications of unpolluted and unpolluted to moderately polluted (classes 1 and 2). The statistical results showed that downwind of the plant in relation to the prevailing winds, there was a strong correlation between soil concentrations of chromium, copper, nickel, and vanadium. Based on the results of this study, it can be concluded that the use of fuel oil at the thermoelectric plant contributed to the accumulation of vanadium and nickel in the soil of the surrounding areas, as well as chromium and copper.  相似文献