5－Br－PADN双峰双波长法测定铁（Ⅲ）     

罗明辉  尹郁芝  蒋南  赵志红 《湖南农业大学学报(自然科学版)》1995,22(5)

研究５－Ｂｒ－ＰＡＤＮ与铁（Ⅲ）的显色反应，在ｐＨ９．０～９．４范围内，当有１０％ＳＤＳ存在时，铁（Ⅲ）与５－Ｂｒ－ＰＡＤＮ形成１：４的稳定配合物。λ＿（ｍａｘ）为５３４ｎｍ，ε为５．１３×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），铁（Ⅲ）浓度在０～１２．５×１０￣（－４）ｇ／Ｌ范围内符合Ｂｅｅｒ定律，用双峰双波长法测定茶叶中痕量铁（Ⅲ），结果满意。  相似文献   

A spatial reasoning approach to estimating paddy rice water demand in Hwanghaenam-do,North Korea     

Min-Won Jang  Jin-Yong Choi  Jeong-Jae Lee 《Agricultural Water Management》2007

The primary objective of this study was to estimate the agricultural water demand of paddy fields in Hwanghaenam-do, North Korea. Three Landsat TM images, GIS data including digital elevation maps, a Thiessen network and administration maps of North Korea, and meteorological data were synthesized for this study. In order to estimate water demand for agricultural use, the FAO Blaney–Criddle method and 10-day crop coefficients of the northern areas of South Korea were used. To classify the Landsat images, supervised and unsupervised classification methods were conducted. Topographical constraints based on paddy rice growing conditions, which are under 7% slope and 200 m above sea level, were taken into account. The results showed an annual net water demand of 611.7 mm/year (916.4 Mt/year) is required for the 150,079 ha of paddy fields and the average gross water demand and design water demand for paddy rice were estimated to be 939.6 mm/year (1408 Mt/year) and 1131.97 mm/year (1695.1 Mt/year), respectively.  相似文献   

Constituents of Asparagus officinalis evaluated for inhibitory activity against cyclooxygenase-2     

Jang DS  Cuendet M  Fong HH  Pezzuto JM  Kinghorn AD 《Journal of agricultural and food chemistry》2004,52(8):2218-2222

As part of a project directed toward the discovery of new cancer chemopreventive agents from plants, two new natural products, asparagusic acid anti-S-oxide methyl ester (1) and asparagusic acid syn-S-oxide methyl ester (2), a new acetylenic compound, 2-hydroxyasparenyn [3',4'-trans-2-hydroxy-1-methoxy-4-[5-(4-methoxyphenoxy)-3-penten-1-ynyl]-benzene] (3), as well as eleven known compounds, asparenyn (4), asparenyol (5), (+/-)-1-monopalmitin (6), ferulic acid (7), 1,3-O-di-p-coumaroylglycerol (8), 1-O-feruloyl-3-O-p-coumaroylglycerol (9), blumenol C, (+/-)-epipinoresinol, linoleic acid, 1,3-O-diferuloylglycerol, and 1,2-O-diferuloylglycerol, were isolated from an ethyl acetate-soluble fraction of the methanol extract of the aerial parts of Asparagus officinalis (Asparagus), using a bioassay based on the inhibition of cyclooxygenase-2 to monitor chromatographic fractionation. The structures of compounds 1-3 were elucidated by 1D- and 2D-NMR experiments ((1)H NMR, (13)C NMR, DEPT, COSY, HMQC, HMBC and NOESY). All the isolates were evaluated for their inhibitory effects against both cyclooxygenase-1 and -2, with the most active compound being linoleic acid.  相似文献   

Organic mulch biowall for PAH contaminated groundwater remediation   总被引：2，自引：0，他引：2  

Youngwoo Seo  Am Jang  Paul L. Bishop   《European Journal of Soil Biology》2007,43(5-6):304

Organic mulch was used as an alternative supporting material in permeable, biological, barrier walls to prevent migration of PAHs. Three types of organic mulch, cypress bark (C), hardwood bark (H) and pine bark nuggets (P) were selected as potential media to capture pollutants or to support PAH-degrading microorganisms. Among the media, the hardwood mulch was selected for biowall testing. To simulate the fate and transport of PAHs in the subsurface biowall under aerobic conditions, two lab scale mulch-biofilm column reactors were operated. Naphthalene was chosen as the model PAH in these studies and was supplied at a loading rate of 50.9 g m⁻² day⁻¹. During the initial operation period of up to 372 pore volumes, the PAH removal efficiency remained stable at over 99%, due to sorption and biodegradation. After that, the mulch-biowall system showed variable removal efficiencies, in the range of 77–99.99%.  相似文献   

Effects of naturally occurring compounds on fibril formation and oxidative stress of beta-amyloid   总被引：2，自引：0，他引：2  

Kim H  Park BS  Lee KG  Choi CY  Jang SS  Kim YH  Lee SE 《Journal of agricultural and food chemistry》2005,53(22):8537-8541

Beta-amyloid (betaA)-induced oxidative toxicity on neuronal cells is a principal route in Alzheimer's disease (AD), and its toxicity occurs after fibril formation. Inhibitory or promoting effects of naturally occurring compounds on betaA fibril formation were evaluated. Among 214 tested compounds, curcuminoids, flavone type flavonoids, and naphthoquinones were shown to be potent inhibitors of betaA fibrilization. The addition of the curcuminoids, curcumin, demethoxycurcumin, and bisdemethoxycurcumin strongly inhibited betaA fibril formation. Flavonoids such as quercetin, rhamnetin, and fisetin strongly inhibited betaA fibril formation. Limonoids, cinnamic acids, and catechins enhanced fibril formation in vitro. Anthothecol possessed the most enhancing activity on fibril formation of the compounds tested. On the other hand, it was found that curcuminoids showed cytotoxicity with the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assay and did not protect HT22 murine neuroblastoma cells from betaA(25-35) insult. Two flavone type flavonoids, morin and quercetin, exhibited no cytotoxicity and strongly protected HT22 murine neuroblastoma cells from betaA(25-35) oxidative attack. Conclusively, morin or quercetin could be a key molecule for the development of therapeutics for AD.  相似文献   

棉花凝集素在种子形成过程中的消长规律   总被引：3，自引：0，他引：3  

李琼芳  江怀仲 《种子》1990,(4):18-20

利用血凝技术对不同抗性棉种及不同发育阶段棉籽血凝活性测定表明:棉花种子血凝活性的强弱与品种抗枯萎病性强弱呈正相关;抗病棉株花粉的血凝活性比感病品种强,抗、感品种未受精的胚珠的血凝活性无明显差异;棉种形成过程中,30天前抗、感品种的血凝活性无明显差异;30天后抗病棉种血凝活性增强,感病品种减弱;棉花凝集素贮存在种子子叶和胚中。  相似文献   

Effect of dietary fermented garlic by Weissella koreensis powder on growth performance, blood characteristics, and immune response of growing pigs challenged with Escherichia coli lipopolysaccharide     

Wang JP  Yoo JS  Jang HD  Lee JH  Cho JH  Kim IH 《Journal of animal science》2011,89(7):2123-2131

Two experiments were conducted to investigate the effect of fermented garlic by Weissella koreensis powder (WKG) on pig growth performance and immune responses after an Escherichia coli lipopolysaccharide (LPS) challenge. In Exp. 1, 120 growing barrows (23.5 ± 0.5 kg of BW and 56 d of age) were used in a 35-d experiment to determine the optimal amounts of WKG. Pigs were randomly allotted to 1 of 5 treatments with 6 replicate pens and 4 pigs per pen. Dietary treatments included 1) NC (negative control; basal diet without antibiotics), 2) PC (positive control; basal diet + 1 g of tylosin/kg), 3) WKG1 (basal diet + 1 g of WKG/kg), 4) WKG2 (basal diet + 2 g of WKG/kg), and 5) basal diet + 4 g of WKG/kg. At the end of the feeding period, 12 pigs each were selected from the NC and WKG2 treatment groups, and 6 pigs were injected with LPS (50 μg/kg of BW) and the other 6 pigs with an equivalent amount of sterile saline, resulting in a 2 × 2 factorial arrangement of treatments. Blood samples and rectal temperature data were collected at 0, 2, 4, 6, 8, and 12 h after challenge. The ADG of pigs fed WKG- and antibiotic-supplemented diets was greater (P<0.05) than NC from d 14 to 35 and the overall phase, but no dosage-dependent effects were observed. At the end of the experiment, the fecal E. coli count was linearly reduced by the increasing amounts of WKG at d 35 (P=0.01). Challenge with LPS increased white blood cell counts at 6 and 8 h (P<0.01) and depressed lymphocyte concentration at 4, 8, and 12 h (P<0.01). During challenge, LPS injection increased rectal temperature at 2, 4, 6, and 8 h postchallenge (P<0.05), and WKG2 alleviated (P<0.05) the increase in the temperature at 2 h postchallenge. The LPS injection increased plasma tumor necrosis factor-α and IGF-1 concentrations at 2, 4, 6, 8, and 12 h (P<0.01), whereas an alleviating effect of WKG was observed at 4, 6, and 8 h after LPS challenge (P<0.05). At 2, 4, and 6 h postchallenge, concentration of cluster of differentiation-antigen-4-positive cells and cluster of differentiation-antigen-8-positive cells (CD4(+) and CD8(+), respectively) increased in the LPS treatments (P<0.05), and the WKG2 boosted this effect (P<0.05). In conclusion, dietary supplementation of WKG2 in growing pigs can improve ADG and have a beneficial effect on the immune response during an inflammatory challenge.  相似文献   

Identification and cloning of two immunogenic Clostridium perfringens proteins, elongation factor Tu (EF-Tu) and pyruvate:ferredoxin oxidoreductase (PFO) of C. perfringens     

Lee K  Lillehoj HS  Li G  Park MS  Jang SI  Jeong W  Jeoung HY  An DJ  Lillehoj EP 《Research in veterinary science》2011,91(3):e80-e86

Clostridium-related poultry diseases such as necrotic enteritis (NE) and gangrenous dermatitis (GD) cause substantial economic losses on a global scale. Two antigenic Clostridium perfringens proteins, elongation factor Tu (EF-Tu) and pyruvate:ferredoxin oxidoreductase (PFO), were identified by reaction with immune sera from commercial meat-type chickens with clinical outbreak of Clostridium infections. In addition to the genes encoding EF-Tu and PFO, C. perfringens alpha-toxin and necrotic enteritis B-like (NetB) toxin were also expressed in Escherichia coli and their corresponding recombinant proteins were purified. Using the four recombinant proteins as target antigens in ELISA immunoassays, high serum antibody titers were observed not only in chickens with clinical signs of Clostridium infections, but also in apparently healthy animals from the same disease-endemic farm. By contrast, no antibodies against any of the proteins were present in the serum of a specific pathogen-free bird. In ELISA using recombinant proteins of C. perfringens, the levels of anti-bacterial protein antibodies were also higher in chickens which were experimentally induced to show NE clinical signs after co-infection with C. perfringens and Eimeria maxima compared with uninfected controls. These results show that two antigenic C. perfringens proteins, EF-Tu and PFO can be useful detection antigens for C. perfringens-afflicted infections in commercial poultry.  相似文献   

Successful therapy of coumatetralyl rodenticide induced pericardial effusion with pericardiocentesis in a dog     

Park C  Lim CY  Kim JH  Jang JI  Park HM 《The Canadian veterinary journal. La revue veterinaire canadienne》2011,52(2):165-168

A 5-year-old, intact male, golden retriever was presented with an acute onset of lethargy and respiratory distress. The dog was diagnosed as having rodenticide intoxication with pericardial effusion. Pericardiocentesis was successfully performed and was followed with a blood transfusion. This case suggests that rodenticide intoxication might cause pericardial effusion in dogs.  相似文献   

Development and characterization of mouse monoclonal antibodies reactive with chicken interleukin-2 receptor αlpha chain (CD25)     

Lee SH  Lillehoj HS  Jang SI  Baldwin C  Tompkins D  Wagner B  Parcells M  Del Cacho E  Hong YH  Min W  Lillehoj EP 《Veterinary immunology and immunopathology》2011,144(3-4):396-404

This study was carried out to develop and characterize mouse monoclonal antibodies (mAbs) against chicken CD25 (chCD25), the alpha chain of the interleukin-2 (IL-2) receptor. A recombinant chimeric chCD25/IgG4 fusion protein was expressed in Chinese hamster ovary (CHO) cells and isolated from spent cell culture medium by protein G affinity chromatography. Purified chCD25 protein was used to immunize mice, from which 54 stable hybridomas secreting chCD25 mAbs were produced. Two mAbs, chCD25-32 and chCD25-54, with high binding affinity for chCD25-expressing CHO cells were selected for further characterization. By flow cytometry, both mAbs detected cells in the spleen, bursa of Fabricius, intestinal duodenum, and immunostained established chicken T cell, B cell, and macrophage cell lines. Both mAbs reacted with a 55 kDa protein on Western blots of lysates from concanavalin A (Con A)-stimulated spleen mononuclear cells. Intraperitoneal injection of chickens with bacterial lipopolysaccharide increased the percentage of chCD25(+) spleen cells by approximately 4-fold compared with untreated animals. In vitro stimulation of spleen cells with Con A increased the percentage of chCD25(+) cells by up to 50-fold compared with cells treated with medium alone. Finally, the chCD25-32 mAb suppressed IL-2-driven spleen cell proliferation and reduced IL-2-induced nitric oxide production. These mAbs may be useful for future investigation of chicken regulatory T cells.  相似文献