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Effects of grass species and grass growth on atmospheric nitrogen deposition to a bog ecosystem surrounded by intensive agricultural land use 下载免费PDF全文
Miriam Hurkuck Christian Brümmer Karsten Mohr Oliver Spott Reinhard Well Heinz Flessa Werner L. Kutsch 《Ecology and evolution》2015,5(13):2556-2571
We applied a 15N dilution technique called “Integrated Total Nitrogen Input” (ITNI) to quantify annual atmospheric N input into a peatland surrounded by intensive agricultural practices over a 2-year period. Grass species and grass growth effects on atmospheric N deposition were investigated using Lolium multiflorum and Eriophorum vaginatum and different levels of added N resulting in increased biomass production. Plant biomass production was positively correlated with atmospheric N uptake (up to 102.7 mg N pot−1) when using Lolium multiflorum. In contrast, atmospheric N deposition to Eriophorum vaginatum did not show a clear dependency to produced biomass and ranged from 81.9 to 138.2 mg N pot−1. Both species revealed a relationship between atmospheric N input and total biomass N contents. Airborne N deposition varied from about 24 to 55 kg N ha−1 yr−1. Partitioning of airborne N within the monitor system differed such that most of the deposited N was found in roots of Eriophorum vaginatum while the highest share was allocated in aboveground biomass of Lolium multiflorum. Compared to other approaches determining atmospheric N deposition, ITNI showed highest airborne N input and an up to fivefold exceedance of the ecosystem-specific critical load of 5–10 kg N ha−1 yr−1. 相似文献
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M. Francz, K. Egervari and Z. Szollosi Intraoperative evaluation of sentinel lymph nodes in breast cancer: comparison of frozen sections, imprint cytology and immunocytochemistry Objective: We analysed the utility of imprint cytology with rapid immunocytochemistry and frozen section analysis for the evaluation of sentinel lymph nodes in breast cancer patients. Methods: The sensitivity, specificity, and positive and negative predictive values have been calculated for each method individually, each pair and all three together. We compared these results with those of routinely processed paraffin sections. Results: The sensitivity and specificity of each of the three methods for detection of metastatic carcinoma were as follows: 69.4% and 97.8% for touch imprint cytology; 58.3% and 100% for frozen sections; 68.5% and 98.9% for rapid immunocytochemistry. When the methods were combined, the highest accuracy was achieved by touch imprint cytology, frozen sections, touch imprint cytology plus rapid immunocytochemistry, or touch imprint cytology frozen section analysis and rapid immunocytochemistry, each of these having identical sensitivity and specificity of 72.2% and 97.8%, respectively. Conclusions: In our study the combined accuracy of the three methods was the same as combining touch imprint cytology and frozen sections or touch imprint cytology plus rapid immunocytochemistry. Rapid immunocytochemistry provides an additional parameter and preserves tissue for permanent sections. 相似文献
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本实验通过测定毛细管凝血时间(CT)、剪尾法出血时间(BT)、活化部分凝血酶时间(APTT)、凝血酶原时间(PT)、凝血酶时间(TT)、优球蛋白溶解时间(ELT)等指标研究藕节醇提物及其不同极性段的体内止血作用.结果表明,藕节醇提物显著缩短小鼠CT、BT,显示很好的止血作用,可能是主要通过缩短APTT、PT,延长ELT... 相似文献
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Paul Peake James Fitzsimons Doug Frood Mel Mitchell Naomi Withers Matt White Rick Webster 《Ecological Management & Restoration》2011,12(2):128-137
Summary Large overbank flood events play an important role in maintaining large‐scale ecological processes and connectivity along and across the floodplains and between the rivers and their floodplains in the southern Murray‐Darling Basin. However, the regulation of rivers means that extensive overbank flooding can only occur in the rare circumstance of extreme flood events. Recent environmental water allocations have focussed on the largest floodplain blocks (‘icon’ sites) and a small set of specific values (e.g. colonial nesting waterbirds), as well as on trialling fine‐scale manipulation of infrastructure (e.g. pumping) to water relatively small areas. There has been no comprehensive systematic assessment of the entire floodplain and its wider set of flood‐dependent natural assets (such as ecosystems and species; herein referred to as ‘natural values’) to maximise the effectiveness of environmental water use and to catalogue values likely to be lost. This paper describes an assessment of some 220 000 ha found to support flood‐dependent natural values in Victoria. We mapped the geographic distribution and estimated components of the flooding requirements (natural flooding frequency, and maximum period without flooding and minimum duration of each flooding event before significant deterioration) for each natural value. Using an example of one stretch of the River Murray, we show how the resultant spatial data can be used with floodplain inundation modelling to compare the outcomes of real or planned environmental watering events; potentially providing tools for management agencies to conserve a wider range of floodplain values than is currently the case. That is, water managers and the public can see what ecosystems and threatened species are intended to be maintained by environmental watering and what values are intended to be abandoned across the whole floodplain, rather than just seeing the small subset of values and ‘icon’ sites that are intended to be maintained. Examples are provided to illustrate how information about the location, water requirements and extent covered by potential floods for specific values can be used to build adaptive watering strategies for areas as large as the whole floodplain. 相似文献
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《Saudi Journal of Biological Sciences》2020,27(3):805-811
In order to assess the efficacy of 18F-FDG PET/CT-based diagnostic model in diagnosing colorectal cancer (CRC) lymph node metastasis (LNM), the 18F-FDG PET/CT medical records of CRC patients were acquired, and the CRC regional LNM diagnostic model was constructed through the combination of image and grain factors of 18F-FDG PET/CT. The specific analysis methods include univariate analysis, multivariate analysis, ROC curve analysis, and statistical analysis. The research results showed statistical differences in TNM staging, intestinal obstructions, tumor infiltration, regional lymph node (LN) SUVmax, regional LN minimum dimension, and remote metastasis between the CRC patients in the LNM positive group and the LNM negative group. Through the comparisons between the diagnostic model proposed in the research and other diagnostic methods, it was found that the AUC (95%CI) and sensitivity of the proposed diagnostic model were the highest, the comprehensive diagnostic efficacy of the diagnostic model was optimal. Therefore, it was concluded that the diagnostic model was of significant application values, which provided the basis for subsequent clinical diagnosis of CRC. 相似文献
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摘要 目的:探讨动态对比增强磁共振(DCE-MRI)联合弥散加权成像(DWI)诊断直肠癌术前T、N分期和系膜淋巴结良恶性的价值。方法:收集2017年2月至2019年10月中国医科大学附属本溪中心医院和中国医科大学附属盛京医院接诊的80例直肠癌患者,均进行常规核磁共振成像(MRI)、DCE-MRI、DWI扫描,获得DCE-MRI、DWI定量参数[转运常数(K trans )、细胞外血管外空间的体积分数(V e )、速率常数(K ep )、表观扩散系数(ADC)],比较不同T、N分期、不同性质系膜淋巴结DCE-MRI、DWI参数,及其对T、N分期和系膜淋巴结性质的诊断效能。结果:直肠癌癌灶K trans 、 K ep 、V e 高于正常肠壁,ADC低于正常肠壁(P<0.05)。TNM分期为TⅢ~Ⅳ期的患者K trans 、 K ep 、V e 高于TⅠ~Ⅱ期,ADC低于TⅠ~Ⅱ期(P<0.05);TNM分期为N1期的患者K trans 、K ep 、V e 高于N0期,ADC低于N0期(P<0.05)。联合诊断的灵敏度、特异度、阳性预测值、阴性预测值较高。结论:DCE-MRI联合DWI对直肠癌术前T、N分期、系膜淋巴结性质诊断价值较高。 相似文献
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Ning Xu Gen-Yi Qu Yu-Peng Wu Yun-Zhi Lin Dong-Ning Chen Xiao-Dong Li Shao-Hao Chen Jin-Bei Huang Qing-Shui Zheng Xue-Yi Xue Yong Wei 《Journal of cellular biochemistry》2020,121(1):231-243
The significance of actin-related protein 2/3 complex subunit 4 (ARPC4) expression in bladder cancer, and its potential role in the invasion and migration of bladder cancer cells, has yet to be determined. This study was to identify the correlation between ARPC4 and lymph node metastasis, and to determine the role of ARPC4 in the invasive migration of T24 bladder cancer cells. One hundred and ninety-eight bladder cancer tissues and 40 normal bladder and lymph node tissues were examined. Tissue microarrays were constructed and subjected to immunohistochemical stating for ARPC4. Multiple logistic analysis was used to determine risk factors associated with bladder cancer metastasis. ARPC4 expression in T24 bladder cancer cells was suppressed using small interfering RNA and changes in protein levels were determined by Western blot analysis. The proliferation of bladder cancer cells after knocking down of ARPC4 was determined by cell counting kit-8. The effects of ARPC4 knockdown on T24 cell invasion and migration was determined using transwell and wound healing assays. Immunofluorescence analysis was performed to examine changes in pseudopodia formation and actin cytoskeleton structure. The expression of ARPC4 was elevated in bladder cancer tissues than normal tissues (84.3% vs 27.5%, P < 0.001). The multivariate logistic analysis demonstrated that the level of ARPC4, as a risk factor, was correlated with lymphatic metastasis (P < 0.05). ARPC4 knockdown attenuated proliferation, migration, invasion, and pseudopodia formation in T24 cells. ARPC4 expression, as a risk factor, is associated with lymphatic metastasis and is upregulated in bladder cancer tissues in comparison with normal tissues. Inhibition of ARPC4 expression significantly attenuates the proliferation, migration, and invasion of bladder cancer cell, possibly due to defects in pseudopodia formation. 相似文献