间歇性充气加压疗法对下肢深静脉血栓患者血液流变学的影响

目的:观察间歇性充气加压疗法(intermittent pneumatic compression,IPC)对下肢深静脉血栓形成(deep vein thrombosis of lower limbs,DVT)患者的治疗效果,并从血液流变学方面探讨间歇性充气加压的作用机理.方法:2003年3月-2010年9月我科收治的243例下肢深静脉血栓患者,将其中42例IPC治疗病例定为B组实验组,145例单纯药物治疗病例中选取60例定为A组对照组.观察两组患者血液流变学指标和小腿肿胀消退情况的对比.结果:两组患者全血粘度、红细胞聚集指数、红细胞电泳时间、红细胞变形性,在治疗第1天较入院时无差异,组间无差异(P＞0.05),第3天较入院时有差异(P＜0.05),组间第3天有差异(P＜0.05),两组患者下肢肿胀度均明显消退,但B组肿胀消退速度明显快于对照组(P＜0.05).结论:间歇性充气加压治疗仪可有效改变血液流变学状态,改善血液高凝状态,有效缓解肢体肿胀症状,缩短住院时间.且不增加治疗难度,使用简单,治疗依从性好.     

1,25 二羟基维生素D3 对兔角膜碱烧伤朗格罕氏细胞影响

目的:研究1,25二羟基维生素D3(骨化三醇)对兔角膜碱烧伤后角膜朗格罕氏细胞分布的影响,并初步探讨其作用机制。方法:在兔角膜制作碱烧伤模型,然后实验组局部和全身给予1,25二羟基维生素D3,分别在第3,7,21天时对正常组,实验组和对照组家兔行角膜共聚焦显微镜,HE染色观察角膜病理改变。结果:正常组角膜中央在三个时间点均未检测出朗格罕氏细胞。实验组和对照组碱烧伤后3、7天角膜中央出现朗格罕氏细胞,对照组密度高于实验组(p<0.05);碱烧伤后21天两组朗格罕氏细胞密度相近(p>0.05)。实验组炎性反应程度在第7,21天时轻于对照组。结论:1,25二羟基维生素D3能够在兔角膜碱烧伤早期抑制朗格罕氏细胞的向心性迁移,并且能在一定程度上抑制炎性反应。     

Carbon limitation leads to suppression of first year oak seedlings beneath evergreen understory shrubs in Southern Appalachian hardwood forests

Inhibition of canopy tree recruitment beneath thickets of the evergreen shrubs Rhododendron maximum L. and Kalmia latifolia L. has long been observed in Southern Appalachian forests, yet the mechanisms of this process remain unresolved. We present a first-year account of suppression of oak seedlings in relation to Rhododendron and Kalmia basal area, light and resource availability, seedling performance and the rates of seedling damage (i.e., herbivory). We found no evidence of first-year seedling suppression or significant resource deficiencies beneath thickets of K. latifolia in mature mixed hardwood stands. Suppression beneath R. maximum was apparent during the first growing season. We found that seedling biomass, light availability prior to canopy closure, and seedling tissue C:N ratios were negatively correlated with R. maximum basal area. Basal area of R. maximum was positively correlated with seedling mortality rates, soil [Al], and early-growing season leaf herbivory rates. Seedling growth was positively correlated with light and tissue C:N, while negatively correlated with soil [Al]. Overall, our results support the inhibition model of shade-mediated carbon limitation beneath dense understory shrubs and indicate the potential importance of herbivory and aluminum toxicity as components of a suppression mechanism beneath R. maximum thickets. We present a causal model of first year inhibition beneath R. maximum in the context of our findings and the results of prior studies.     

Nutrient uptake as a contributing explanation for deep rooting in arid and semi-arid ecosystems

Explanations for the occurrence of deep-rooted plants in arid and semi-arid ecosystems have traditionally emphasized the uptake of relatively deep soil water. However, recent hydrologic data from arid systems show that soil water potentials at depth fluctuate little over long time periods, suggesting this water may be rarely utilized or replenished. In this study, we examine the distributions of root biomass, soil moisture and nutrient contents to 10-m depths at five semi-arid and arid sites across southwestern USA. We couple these depth distributions with strontium (Sr) isotope data that show deep (>1 m) nutrient uptake is prevalent at four of the five sites. At all of the sites, the highest abundance of one or more of the measured nutrients occurred deep within the soil profile, particularly for P, Ca²⁺ and Mg²⁺. Phosphate contents were greater at depth than in the top meter of soil at three of five sites. At Jornada, for example, the 2–3 m depth increment had twice the extractable P as the top meter of soil, despite the highest concentrations of P occurring at the surface. The prevalence of such deep resource pools, and our evidence for cation uptake from them, suggest nutrient uptake as a complementary explanation for the occurrence of deep-rooted plants in arid and semi-arid systems. We propose that hydraulic redistribution of shallow surface water to deep soil layers by roots may be the mechanism through which deep soil nutrients are mobilized and taken up by plants.Electronic Supplementary Material Supplementary material is available for this article at     

云南抚仙湖沉水植物分布及群落结构特征

2005年6～7月对抚仙湖沉水植物进行了调查。共采集到沉水植物12种。沉水植物在抚仙湖沿岸浅水区均有不同程度的分布,主要分布在北岸、南岸、河口以及湖湾。分布区内平均水深4．27m,平均透明度2．96m。优势种为黑藻、穗状狐尾藻、篦齿眼子菜、金鱼藻和苦草,其优势度分别为59．08％、54．47％、54．26％、48．71％和48．30％,占群落总优势度的65．19％。根据优势种及组成特征,可将沉水植物群落分为11个类型。全湖沉水植物分布区面积318．8hm^2,资源量19502．79t,平均生物量6118g/m^2。2005年与1980年前后和2003年的调查结果相比,抚仙湖沉水植物、生物量和分布范围显著增加。     

Deep brain stimulation amplitude alters posture shift velocity in Parkinson’s disease

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is now widely used to alleviate symptoms of Parkinson’s disease (PD). The specific aim of this study was to identify posture control measures that may be used to improve selection of DBS parameters in the clinic and this was carried out by changing the DBS stimulation amplitude. A dynamic posture shift paradigm was used to assess posture control in 4 PD STN-DBS subjects. Each subject was tested at 4 stimulation amplitude settings. Movements of the center of pressure and the position of the pelvis were monitored and several quantitative indices were calculated. The presence of any statistically significant changes in several normalized indices due to reduced/no stimulation was tested using the one-sample t test. The peak velocity and the average movement velocity during the initial and mid phases of movement towards the target posture were substantially reduced. These results may be explained in terms of increased akinesia and bradykinesia due to altered stimulation conditions. Thus, the dynamic posture shift paradigm may be an effective tool to quantitatively characterize the effects of DBS on posture control and should be further investigated as a tool for selection of DBS parameters in the clinic.     

Cogongrass (Imperata cylindrica)—Biology,Ecology, and Management

Cogongrass is considered to be one of the ten most troublesome and problematic weedy species in the world. This species is found throughout tropical and subtropical regions, generally in areas disturbed by human activities. Over 100 common names have been associated with cogongrass, including japgrass, speargrass, alang-alang, and bladygrass. Although this species has several commercial uses, the problems associated with its weediness far outweigh most positive benefits. Cogongrass is a major impediment to reforestation efforts in southeast Asia, the number one weed in agronomic and vegetable production in many parts of Africa, and is responsible for thousands of hectares of lost native habitat in the southeastern U.S. Biologically, cogongrass possesses several features that foster its spread and persistence. Management efforts for cogongrass consist of an integrated approach with several control strategies. In agronomic production, the use of cover crops is widely successful, but incorporation into the overall production scheme is challenging. Success has been achieved with continuous deep tillage or chemical applications, but long-term eradication/suppression must employ sustainable revegetation strategies.     

烧伤对兔血红细胞内游离氨基酸浓度的影响

动态观察烧伤兔血红细胞内游离氨基酸的代谢变化。以日立 835 - 5 0型氨基酸自动分析仪测定 30 %TBSA兔烧伤后 1、3、7、15和 2 0d血红细胞内游离氨基酸的含量。结果显示 ,烧伤后多数测试点红细胞内游离氨基酸不同程度降低 ;伤后 1天降低最显著 ;苏、丙、缬、组、精和脯氨酸伤后各个时间点降低 ,多数时间点显著降低 (P <0 .0 5 - 0 .0 1)。结果提示烧伤后红细胞内游离氨基酸依靠易化扩散参与全身氨基酸的再分布     

Spatial and temporal changes in epibenthic communities at deep,hard bottom aquaculture sites in Newfoundland

This study explores spatio-temporal changes in epibenthic communities due to salmon aquaculture at deep (>30 m), hard-bottom dominated sites in Newfoundland (Canada). Using a drop-camera approach, we followed changes with production at two aquaculture sites, as well as potential recovery processes at two fallow sites, comparing their epibenthic composition with nearby non-production sites. Multivariate analysis revealed that aquaculture production led to rapid changes in epibenthic communities, as evidenced primarily by the presence of two visual indicators: bacterial mats and opportunistic polychaetes. Due to low taxon richness and abundances, as well as variability among sites, no clear intermediate successional stages were apparent. Beggiatoa-like mats and opportunistic polychaetes appeared rapidly once aquaculture production began; these indicators did not increase in spatial extent during the survey and were typically observed up to 100 m, and occasionally up to 160 m from cages. After 15 months of fallowing, Beggiatoa-like mats and opportunistic polychaetes remained present at sites and were occasionally accompanied by few other taxa, suggesting incomplete recovery.