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排序方式: 共有475条查询结果,搜索用时 15 毫秒
471.
Habashi JP Judge DP Holm TM Cohn RD Loeys BL Cooper TK Myers L Klein EC Liu G Calvi C Podowski M Neptune ER Halushka MK Bedja D Gabrielson K Rifkin DB Carta L Ramirez F Huso DL Dietz HC 《Science (New York, N.Y.)》2006,312(5770):117-121
Aortic aneurysm and dissection are manifestations of Marfan syndrome (MFS), a disorder caused by mutations in the gene that encodes fibrillin-1. Selected manifestations of MFS reflect excessive signaling by the transforming growth factor-beta (TGF-beta) family of cytokines. We show that aortic aneurysm in a mouse model of MFS is associated with increased TGF-beta signaling and can be prevented by TGF-beta antagonists such as TGF-beta-neutralizing antibody or the angiotensin II type 1 receptor (AT1) blocker, losartan. AT1 antagonism also partially reversed noncardiovascular manifestations of MFS, including impaired alveolar septation. These data suggest that losartan, a drug already in clinical use for hypertension, merits investigation as a therapeutic strategy for patients with MFS and has the potential to prevent the major life-threatening manifestation of this disorder. 相似文献
472.
The effect of crate height on the behavior of female turkeys during commercial pre‐slaughter transportation 下载免费PDF全文
Guido Di Martino Katia Capello Anna Lisa Stefani Luca Tripepi Angelica Garbo Marina Speri Matteo Trolese Michele Brichese Stefano Marangon Lebana Bonfanti 《Animal Science Journal》2017,88(10):1651-1657
Limited information is available on suitable height of transport crates for turkeys. We compared behaviors and physiological indicators of four groups of 10 female turkeys each confined in either conventional (38.5 cm height) or experimental (77 cm height) crates during six commercial pre‐slaughter transportations for 86 km (76 ± 4 min) along two tracts with one‐lane streets, crossroads, bends, roundabouts (S1 and S2) and a highway tract (H) between S1 and S2. Only 36% of birds in the higher crates maintained a standing position. In conventional versus experimental crates, the frequency of rising attempts was five/bird/hour versus less than one/bird/hour, while wing flapping was seven/bird/hour versus 20/bird/hour, and balance loss was one versus four/bird/hour. The behaviors of both groups differed significantly according to the route tract, with a lower frequency of stress‐related behaviors at H. No scratches, fractures or hematomas were detected in any birds after transportation. Crate height had no significant effect on hemato‐biochemical markers. These results suggest that crates enabling a standing position may increase potentially dangerous behaviors. Moreover, busy and curvy routes should be avoided, as they may contribute to increasing the frequency of stress‐related behaviors. 相似文献
473.
M. M. Mufarrege H. R. Hadad G. A. Di Luca G. C. Sanchez M. A. Maine S. E. Caffaratti M. C. Pedro 《Water, air, and soil pollution》2018,229(12):384
The removal efficiency and tolerance of Typha domingensis to Cr(VI) in treatments with and without organic matter (OM) addition were evaluated in microcosm-scale wetlands. Studied Cr(VI) concentrations were 15 mg L?1, 30 mg L?1, and 100 mg L?1, in treatments with and without OM addition, arranged in triplicate. Controls (without neither metal nor OM addition—without metal with OM addition) were disposed. Cr(VI) was removed efficiently from water in all treatments. OM addition enhanced significantly Cr(VI) and total Cr removals from water. In the treatments with OM addition, significantly higher Cr concentrations were found in sediment than the treatments without OM addition. Plants of the treatments without OM addition showed significantly higher Cr concentrations in tissues but lower biomass increase than the treatments with OM addition. The highest Cr concentrations in tissues were observed in submerged parts of leaves, followed by roots. According to SEM analysis, in the 100 mg L?1 treatments, the highest Cr accumulation was observed in the epidermis of old leaves. Although Cr(VI) produced changes in root morphology, the OM addition favored the plant growth. In T. domingensis, root morphological plasticity is an important mechanism to improve metal tolerance and Cr uptake in wetland systems minimizing the environmental impact. 相似文献
474.
The worldwide increase of human pressure in rural areas has resulted in a progressive fragmentation of agro-forest landscapes. Relatively few studies have identified processes of landscape modification and patch fragmentation reflecting long-term human activity from those caused by recent urbanization stimulated by economic development, population growth and improved accessibility of rural areas. In rural districts dominated by high-quality crop mosaics and exposed to increasing levels of human pressure, urbanization-driven changes in the use of land have determined complex and non-linear processes of landscape fragmentation which deserve further investigation. Multidimensional procedures and data mining are appropriate to explore such transformations, basing on a comprehensive assessment of landscape metrics. The present study investigates changes in land-use and landscape structure (2000–2008) in three districts of Latium (central Italy) featuring different cropping systems, physiographic attributes and level of human pressure. A principal component analysis was run to identify a core set of metrics aimed at (i) evaluating the role of traditional cropping systems in the preservation of traditional agro-forest systems and (ii) inferring the relationship between spatial heterogeneity in rural landscapes and socio-ecological processes of change. Our results indicate that crop intensification has contributed to landscape homogeneity and simplification in all areas studied, in contrast with the effects of urban expansion resulting in a more fragmented and diversified landscape with relict tree crop patches. The findings of this study clarify the contribution of traditional tree crop systems to sustainable structures and functions of rural landscapes by preserving the place-specific eco-mosaic complexity. 相似文献
475.
The Mediterranean region has been regarded as a critical hotspot for desertification due to the impact of soil degradation, the land‐use changes and the climate variations. Few large‐scale studies have been devoted to analyse trends in land sensitivity to desertification in the northern Mediterranean basin. The present paper contributes to this deserving issue by quantifying the level of land sensitivity to desertification in Italy at seven points between 1960 and 2010 at a fine spatial scale. The approach used followed the Environmentally Sensitive Area scheme that assesses changes in four key themes (climate, soil, vegetation and land management) related to land degradation processes. Italian land was classified into four levels of sensitivity to desertification (non‐affected, potentially affected, fragile and critical) according to the Environmentally Sensitive Area framework. Interestingly, although land surface area classified as ‘fragile’ and ‘critical’ grew homogeneously in Italy between 1960 and 1990, the increase observed in the most recent time period was spatially clustered and contributed to reverse the polarisation in ‘structurally vulnerable’ and ‘non‐affected’ regions observed in Italy. The paper discussed these trends in the light of socioeconomic changes that occurred in Italy after World War II. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献