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MOHAMED H. K. PATHAK S. ROY D. N. HUTCHINSON T. C. MCLAUGHLIN D. L. KINCH J. C. 《Water, air, and soil pollution》1997,96(1-4):321-327
Wood cores were taken at breast height of mature sugar maple (Acer Saccharum Marsh.) trees of approximately the same age from four sites in Ontario, Canada differing in soil characteristics and general tree health. The soils of two of the sites were acidic (podzols), while the soils of the other two sites were calcareous (brunisols). Selected elemental analyses using Neutron Activation Analysis were conducted on the soils and the xylem wood of the sugar maple trees, and the results were compared relative to tree health. Aluminum in stem xylem was found to be significantly higher in declining trees (mean 7.7 ppm) relative to the healthy trees (mean 4.0) from the acidic sites, where aluminum was freely available in the soil. Soil extractable aluminum was also significantly higher in the soil adjacent to the declining trees (mean 5.10) compared to the healthy trees (mean 3.20). These results show that xylem aluminum contents reflect the increased availability of aluminum in acidifying soils and provide additional evidence that dendrochemistry may be used as a proxy environmental monitoring tool. 相似文献
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MOHAMED H. ABUSHHIWA NOURIA S. SALEHI ROBERT C. WHITTON JENNIFER A. CHARLES PETER J. FINNIN PETER M. LORDING BRUCE W. PARRY 《Veterinary radiology & ultrasound》2009,50(5):545-549
Technetium-99m stannous colloid (99m TcSnC) has been used to radiolabel human leukocytes to investigate various inflammatory disorders. We investigated the in vitro behavior of feline leukocytes labeled in whole blood with 99m TcSnC. Heparinized blood samples were collected from healthy cats and divided into control and test aliquots. The latter were labeled with 99m TcSnC using a standard procedure. Leukocyte viability was determined for each sample using a trypan blue exclusion test. Labeling efficiency was determined for test aliquots. Test aliquots were layered onto Histopaque-1077® and centrifuged before measurement of radioactivity of the blood components. Leukocytes from radiolabeled and control samples were washed and incubated with opsonized zymosan particles to allow assessment of phagocytic function. Aliquots were taken from radiolabeled feline leukocyte samples at 1, 3, 4, and 7 h postlabelling. After centrifugation of each aliquot, radioactivity of the supernatant and pellet was measured and the labeling retention determined. Leukocyte viability in both radiolabeled and control samples was >98%. The labeling efficiency was 95.2±0.14%. The distribution of radioactivity in feline blood was found to be 3.4±0.18% in plasma, 39.0±0.37% in erythrocytes, and 57.6±0.38% in leukocytes. Labeled feline leukocytes had phagocytic activity of 90.9±0.18% (control 91.3±0.15%). The radiolabeled leukocytes retained 93.4±0.19% of the radioactivity up to 7 h postlabeling. 99m TcSnC efficiently labeled feline leukocytes with no effect on viability and minimal effect on phagocytic function. The percentage retention of radioactivity by the leukocytes was still high at 7 h postlabeling. 相似文献
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LI Chen LIU Xuan-xuan ABOUELNASR Hesham MOHAMED HAMED Arisha KOU Meng TANG Wei YAN Hui WANG Xin WANG Xiao-xiao ZHANG Yun-gang LIU Ya-ju GAO Run-fei MA Meng LI Qiang 《农业科学学报》2022,21(10):2865-2875
As a critical food crop, sweetpotato (Ipomoea batatas (L.) Lam.) is widely planted all over the world, but it is deeply affected by Sweetpotato Virus Disease (SPVD). The present study utilized short tandem target mimic (STTM) technology to effectively up-regulate the expression of laccase (IbLACs) by successfully inhibiting the expression of miR397. The upstream genes in the lignin synthesis pathway were widely up-regulated by feedback regulation, including phenylalanine ammonialyase (PAL), 4-coumarate-CoAligase (4CL), hydroxycinnamoyl CoA:shikimatetransferase (HTC), caffeicacid O-methyltransferase (COMT), and cinnamyl alcohol dehydrogenase (CAD). Meanwhile, the activities of PAL and LAC increased significantly, finally leading to increased lignin content. Lignin deposition in the cell wall increased the physical defence ability of transgenic sweetpotato plants, reduced the accumulation of SPVD transmitted by Bemisia tabaci (Gennadius), and promoted healthy sweetpotato growth. The results provide new insights for disease resistance breeding and green production of sweetpotato. 相似文献
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Ramachandran SANTHANAKRISHNAN Abdul Hameed MOHAMED SAMSOOR ALI Uthirapathi ANBARASAN 《中国鸟类》2011,2(4):193-199
我们于2007年至2009年通过食丸分析研究了印度泰米尔纳德邦马杜赖地区横斑腹小鸮(Athene brama)的食性及猎物谱.共分析了食丸4181个,记录了共16种猎物的40278个残余物.每个食丸中的猎物种类为1-31个,平均9.6±3.03个.分析表明,该地区横斑腹小鸮的主要猎物为无脊椎动物(昆虫类占83.0％,蛛... 相似文献
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J. P. MOCHEL M. PEYROU M. FINK G. STREHLAU R. MOHAMED J. M. GIRAUDEL B. PLOEGER M. DANHOF 《Journal of veterinary pharmacology and therapeutics》2013,36(2):174-180
Mochel, J. P., Peyrou, M, Fink, M, Strehlau, G, Mohamed, R, Giraudel, J. M., Ploeger, B, Danhof, M. Capturing the dynamics of systemic Renin‐Angiotensin‐Aldosterone System (RAAS) peptides heightens the understanding of the effect of benazepril in dogs. J. vet. Pharmacol. Therap. 36 , 174–180. In dogs, activation of the Renin‐Angiotensin‐Aldosterone System (RAAS) is an important feature of congestive heart failure (CHF). Long‐term increases in angiotensin II (AII) and aldosterone (ALD) lead to the progression of heart failure to its end stage. Angiotensin‐converting enzyme inhibitors (ACEIs) are the foremost therapeutic option in the management of CHF. Recent literature has challenged the efficacy of ACEIs, based on modest reduction in urinary aldosterone (UALD) excretion despite marked inhibition of ACE activity. This study was designed to heighten the understanding of the effect of benazepril, a potent ACEI, on the RAAS, using a low‐sodium diet as an experimental model of RAAS activation. Time course profiles of RAAS peptides and related areas under the curve (AUC24 hours) were used for comparison between benazepril and placebo groups. Results indicated substantial changes in the dynamics of these biomarkers. At presumed benazeprilat steady state, significant differences in AUC24 hours of plasma renin activity (+90%), angiotensin I (+43%), and AII (?53%) were found between benazepril and placebo‐treated dogs. ALD decreased by 73% in plasma but only by 5% in urine. In conclusion, despite modest reduction in UALD excretion, benazepril markedly influences RAAS dynamics in dogs. 相似文献
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HAMADA RAGAB ABDO GHAREIB MOHAMED SAYED ABDELHAMED OLA HAMMOUDA IBRAHIM 《Weed Biology and Management》2010,10(1):64-72
From the active acetone fraction of Chenopodium murale , vanillic acid was isolated and identified, based on 1 H and 13 C nuclear magnetic resonance spectral analyses. Free phenolic compounds inside the active acetone were qualified and quantified by using high performance liquid chromatography analysis, which revealed the presence of seven compounds with an abundance of vanillic and p -hydroxybenzoic acids. The allelopathic potential of the acetone fraction and vanillic acid was evaluated through laboratory bioassays against tomato plants. Our results showed that the allelopathic potential induced by low concentrations of the acetone fraction and vanillic acid stimulated the germination and growth of tomato and had stimulating effects on the activity of some antioxidant enzymes. We observed an enhancement in the activity of catalase, peroxidase, superoxide dismutase, and polyphenol oxidase, as well as the content of soluble protein and phenolic glycoside. Meanwhile, the levels of free phenolic compounds, H2 O2 , and lipid peroxidation decreased. The highest stimulations were recorded at 50 p.p.m. of acetone fraction and 0.5 p.p.m. of vanillic acid. In contrast, the highest concentrations exerted negative effects on all the measured parameters to record the maximum value of inhibition at 400 p.p.m. of acetone fraction and 4 p.p.m. of vanillic acid. These results proved the antioxidative effects of active acetone and vanillic acid at low concentrations and their potent use as a stimulator for tomato germination and growth. 相似文献
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[目的]为探讨苹果属植物无融合生殖分子机制。[方法]以苹果属平邑甜茶及杂种后代33#为试材,以苹果基因组CDS序列设计引物,通过PCR扩增技术克隆出SERK同源基因的cDNA全长序列,命名为MhSERK1和MhdSERK1(GenBank登录号JQ231273和JQ231272),利用实时定量RTqPCR的方法检测了这两个基因在平邑甜茶和杂种后代各组织和器官中的表达模式。[结果]序列分析显示MhSERK1和MhdSERK1编码区序列全长为1 899 bp和1 881 bp,分别编码632和626个氨基酸,其氨基酸序列与其他植物的SERK1同源基因所编码的氨基酸同源性都在80%以上,特别是与葡萄科龙眼品种同源性最高,高达92.56%,与模式植物拟南芥、烟草等植物的SERK同源基因都具有很高的同源性。实时定量PCR结果表明,在平邑甜茶和杂种后代不同组织、花器官中SERK1基因的表达量存在差异,其中在子房中的表达量最高,在营养生长的组织中表达量很低,在平邑甜茶花蕾期的子房中表达量最高。[结论]推测该基因在平邑甜茶和杂种后代的生殖发育过程中可能发挥重要作用。 相似文献
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Surface soil samples from seven profiles from the central plains of Sudan were investigated using XRD, chemical analysis and Mössbauer spectroscopy measured at 15K. Dioctahedral montmorillonite was the main constituent with different proportions of kaolinite and chlorite. Goethite was found as fine iron oxyhydroxide in all the samples, with haematite detected in two pedons. Crystallinity of the clays was observed to correlate negatively with the amount of free iron oxide in the soil. The influence of the climatic factors on the soil and its formation is discussed. 相似文献
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