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41.
42.
Nam Jin Noh Yowhan Son Jin Woo Koo Kyung Won Seo Rae Hyun Kim Yoon Young Lee Kyung Seun Yoo 《Journal of Plant Biology》2010,53(1):61-69
The nitrogenase activity, root nodule biomass, and rates of nitrogen (N) fixation were measured in 25-year-old pure north-
and south-facing Robinia pseudoacacia stands in an urban forest of Seoul (Kkachisan Mountain) in central Korea. The nitrogenase activity was estimated using an
acetylene reduction (AR) assay, which showed an increasing trend during the early growing season, with sustained high rates
from June through to September with a decrease thereafter. July had the highest nitrogenase activity rate (micromoles C2H4 per gram dry nodule per hour), averaging 95.8 and 115.1 for the north- and south-facing stands, respectively. The maximum
root nodule biomass (kilograms per hectare) was 45.7 and 9.1 for the north- and south-facing stands in July, respectively.
The AR rate appeared to be strongly correlated to the soil temperature (r
2 = 0.68, P < 0.001) and soil pH (r
2 = 0.59, P < 0.001) while root nodule biomass was correlated to the soil temperature (r
2 = 0.36, P < 0.01) and water content (r
2 = 0.35, P < 0.05). The soil temperature showed clear differences between seasons, while there was a significant difference in soil pH,
organic matter, total N concentrations, and available phosphorus between the north- and south-facing stands. The N2 fixation rates during the growing season varied from 0.1 to 37.5 kg N ha−1 month−1 depending on the sampling location and time. The annual N2 fixation rate (kg N per hectare per year) was 112.3 and 23.2 for the north- and south-facing stands, respectively. The differences
in N2 fixation rate between the two stands were due mainly to the differences in total nodule biomass. 相似文献
43.
Won Noh Sang-Woo Kim Bae Dong-Won Jae-Yean Kim Hyeon-Su Ro 《Journal of microbiology (Seoul, Korea)》2010,48(2):253-256
Pleurotus eryngii was transformed via restriction enzyme-mediated integration. In order to construct the transformation plasmid, the enhanced
cyan fluorescent protein (ECFP) gene was ligated next to the gpd promoter of the plasmid pAN7-1. Transformation was facilitated via the heat treatment of a transformation mixture containing
1 μg of the HindIII-digested plasmid DNA and 106 mushroom protoplasts in 40% polyethyleneglycol solution, resulting in 10–40 hygromycin-resistant transformants. Successful
transformation was evidenced by PCR, Southern blot, and confocal fluorescence microscopic analyses on the selected transformants.
To date, this is the first report on the transformation of P. eryngii by REMI technique. 相似文献
44.
Autotrophic and heterotrophic respiration in needle fir and Quercus-dominated stands in a cool-temperate forest, central Korea 总被引:3,自引:0,他引:3
Na-yeon Lee Jin-Woo Koo Nam Jin Noh Joon Kim Yowhan Son 《Journal of plant research》2010,123(4):485-495
To investigate annual variation in soil respiration (R
S) and its components [autotrophic (R
A) and heterotrophic (R
H)] in relation to seasonal changes in soil temperature (ST) and soil water content (SWC) in an Abies holophylla stand (stand A) and a Quercus-dominated stand (stand Q), we set up trenched plots and measured R
S, ST and SWC for 2 years. The mean annual rate of R
S was 436 mg CO2 m−2 h−1, ranging from 76 to 1,170 mg CO2 m−2 h−1, in stand A and 376 mg CO2 m−2 h−1, ranging from 82 to 1,133 mg CO2 m−2 h−1, in stand Q. A significant relationship between R
S and its components and ST was observed over the 2 years in both stands, whereas a significant correlation between R
A and SWC was detected only in stand Q. On average over the 2 years, R
A accounted for approximately 34% (range 17–67%) and 31% (15–82%) of the variation in R
S in stands A and Q, respectively. Our results suggested that vegetation type did not significantly affect the annual mean
contributions of R
A or R
H, but did affect the pattern of seasonal change in the contribution of R
A to R
S. 相似文献
45.
Nam Jin Noh Yowhan Son Sue Kyoung Lee Tae Kyung Yoon Kyung Won Seo Choonsig Kim Woo-Kyun Lee Sang Won Bae Jaehong Hwang 《Journal of plant research》2010,123(4):411-419
We investigated the influence of stand density [938 tree ha−1 for high stand density (HD), 600 tree ha−1 for medium stand density (MD), and 375 tree ha−1 for low stand density (LD)] on soil CO2 efflux (R
S) in a 70-year-old natural Pinus densiflora S. et Z. forest in central Korea. Concurrent with R
S measurements, we measured litterfall, total belowground carbon allocation (TBCA), leaf area index (LAI), soil temperature
(ST), soil water content (SWC), and soil nitrogen (N) concentration over a 2-year period. The R
S (t C ha−1 year−1) and leaf litterfall (t C ha−1 year−1) values varied with stand density: 6.21 and 2.03 for HD, 7.45 and 2.37 for MD, and 6.96 and 2.23 for LD, respectively. In
addition, R
S was correlated with ST (R
2 = 0.77–0.80, P < 0.001) and SWC (R
2 = 0.31–0.35, P < 0.001). It appeared that stand density influenced R
S via changes in leaf litterfall, LAI and SWC. Leaf litterfall (R
2 = 0.71), TBCA (R
2 = 0.64–0.87), and total soil N contents in 2007 (R
2 = 0.94) explained a significant amount of the variance in R
S (P < 0.01). The current study showed that stand density is one of the key factors influencing R
S due to the changing biophysical and environmental factors in P. densiflora. 相似文献
46.
Jessica AB van Nies Rute B Marques Stella Trompet Zuzana de Jong Fina AS Kurreeman Rene EM Toes J Wouter Jukema Tom WJ Huizinga Annette HM van der Helm-van Mil 《Arthritis research & therapy》2010,12(2):R38
Introduction
Recently an association between a genetic variation in TRAF1/C5 and mortality from sepsis or cancer was found in rheumatoid arthritis (RA). The most prevalent cause of death, cardiovascular disease, may have been missed in that study, since patients were enrolled at an advanced disease stage. Therefore, we used an inception cohort of RA patients to investigate the association between TRAF1/C5 and cardiovascular mortality, and replicate the findings on all-cause mortality. As TRAF1/C5 associated mortality may not be restricted to RA, we also studied a large cohort of non-RA patients. 相似文献47.
Intervention with mesenchymal stem cells (MSCs) represents a promising therapeutic tool in treatment-refractory autoimmune
diseases. A new report by Schurgers and colleagues in a previous issue of Arthritis Research & Therapy sheds novel mechanistic insight into the pathways employed by MSCs to suppress T-cell proliferation in vitro, but, at the same time, indicates that MSCs do not influence T-cell reactivity and the disease course in an in vivo arthritis model. Such discrepancies between the in vitro and in vivo effects of potent cellular immune modulators should spark further research and should be interpreted as a sign of caution
for the in vitro design of MSC-derived interventions in the setting of human autoimmune diseases. 相似文献
48.
David R. Thomas Azis Araffin M.Noh Hj Jalil Bob C.S. Yong Robert J. Cooke Clifford Wood 《Phytochemistry》1981,20(6):1241-1244
Carnitine increases chlorophyll production in greening barley leaves. [Methyl-14C]carnitine fed to greening leaves was not utilized as a carbon sou 相似文献
49.
50.
We investigated the protective activity of radicicol, an antifungal antibiotic, against inflammation-induced neurotoxicity in neuron-glia cultures. Radicicol potently prevented the loss of neuronal cell bodies and neurites from LPS/IFN-gamma-induced neurotoxicity in rat cortical neuron-glia cultures with an EC(50) value of 0.09 microM. Radicicol inhibited the LPS/IFN-gamma-induced expression of inducible nitric oxide synthase (iNOS) and production of nitric oxide (NO) in microglia. Additionally, radicicol decreased the LPS/IFN-gamma-induced release of tumor necrosis factor-alpha (TNF-alpha) in the cultures. The inhibitory potency of radicicol against the production of NO and TNF-alpha was well correlated with the protection of neurons. These results suggest that the protective effect of radicicol against LPS/IFN-gamma-induced neuronal cell death in neuron-glia cultures is mediated via the inhibition of TNF-alpha release, as well as the suppression of iNOS expression in microglia. 相似文献