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1.
P. Merino J.M. Estavillo L.A. Graciolli M. Pinto M. Lacuesta A. Muñoz-Rueda C. Gonzalez-Murua 《Soil Use and Management》2002,18(2):135-141
Abstract. Nitrous oxide (N2 O) is involved in both ozone destruction and global warming. In agricultural soils it is produced by nitrification and denitrification mainly after fertilization. Nitrification inhibitors have been proposed as one of the management tools for the reduction of the potential hazards of fertilizer-derived N2 O. Addition of nitrification inhibitors to fertilizers maintains soil N in ammonium form, thereby gaseous N losses by nitrification and denitrification are less likely to occur and there is increased N utilization by the sward. We present a study aimed to evaluate the effectiveness of the nitrification inhibitor dicyandiamide (DCD) and of the slurry additive Actilith F2 on N2 O emissions following application of calcium ammonium nitrate or cattle slurry to a mixed clover/ryegrass sward in the Basque Country. The results indicate that large differences in N2 O emission occur depending on fertilizer type and the presence or absence of a nitrification inhibitor. There is considerable scope for immediate reduction of emissions by applying DCD with calcium ammonium nitrate or cattle slurry. DCD, applied at 25 kg ha–1 , reduced the amount of N lost as N2 O by 60% and 42% when applied with cattle slurry and calcium ammonium nitrate, respectively. Actilith F2 did not reduce N2 O emissions and it produced a long lasting mineralization of previously immobilized added N. 相似文献
2.
细菌耐药拮抗剂的研究 总被引:6,自引:1,他引:5
本文介绍了具有拮抗细菌耐药性作用的物质的研究进展情况,包括灭活酶抑制剂、药物渗透促进剂、外输泵抑制剂、细菌生物被膜抑制剂、抗菌药物增强剂、耐药质粒消除剂等。 相似文献
3.
M. A. De Waard J. G. M. Van Nistelrooy 《European journal of plant pathology / European Foundation for Plant Pathology》1982,88(6):231-236
Fenarimol-resistant isolates ofPenicillium italicum with cross-resistance to imidazole and triazole fungicides which inhibit ergosterol biosynthesis were tested for their sensitivity to fenpropimorph. Radial growth tests on PDA showed that the isolates (n=6) lacked cross-resistance to fenpropimorph or displayed enhanced sensitivity to the fungicide (negatively correlated cross-resistance). Control of blue mold decay of oranges incited by the wild-type isolate could be achieved by dipping fruits in suspensions of fenpropimorph at a concentration of 100 mg ml–1. Decay of oranges incited by the fenarimol-resistant isolates was controlled at the same or at a lower concentration (30 mg ml–1), thus showing that the normal or increased sensitivity to fenpropimorph is also expressed under in vivo conditions.Samenvatting Fenarimol-resistente isolaten vanPenicillium italicum met kruisresistentie tegen imidazool-en triazoolfungiciden die de ergosterolbiosynthese remmen, werden getoetst op hun gevoeligheid voor fenpropimorf. Radiale groeiproeven op PDA toonden aan dat de isolaten (n=6) geen kruisresistentie bezaten met fenpropimorf of een verhoogde gevoeligheid voor het middel vertoonden (negatief gecorreleerde kruisresistentie). Op sinaasappels konPenicillium-rot, veroorzaakt door het wild-type bestreden worden door middel van een dompelbehandeling met fenpropimorf bij een dosering van 100 g ml–1). Bestrijding van rot veroorzaakt door fenarimil-resistente isolaten werd verkregen bij dezelfde of een lagere dosering (30 g ml–1); aldus werd aangetoond dat de normale of verhoogde gevoeligheid voor fenpropimorf ook in vivo tot uiting komt. 相似文献
4.
The serine proteases, tissue‐ and urokinase‐type plasminogen activators (PLAT and PLAU) and their inhibitors SERPINE1/2 are regulators of plasminogen to plasmin conversion. They are widely expressed in ovarian tissues, including granulosa and cumulus cells, and their expression is regulated by gonadotropins. The aim of this work was to assess the effect of serine protease inhibitors (aprotinin and AEBSF) and SERPINE1/2 on FSH‐induced cumulus cell expansion, the production of prostaglandin E2 (PGE2) and retention of hyaluronic acid (HA) in expanding cumulus. The serine protease activity proved to be essential for the production of PGE2 and also for the retention of HA; the inhibition of plasminogen activators by SERPINE1/2 had the same effect. Collectively, these data indicate that plasmin is required for proper function of expanding cumulus cells in vitro and presumably also in vivo in the pre‐ovulatory follicles. 相似文献
5.
6.
J. Guan J. C. Kapteyn A. Kerkenaar M. A. De Waard 《European journal of plant pathology / European Foundation for Plant Pathology》1992,98(5):313-324
Differential accumulation of [14C]imazalil and [14C]fenarimol by germlings of wild-type and DMI-resistant isolates ofPenicillium italicum was studied at various pH values. At pH 7 and 8 the low-resistant isolate E300–3 accumulated 22% and 35%, respectively, less imazalil than the wild-type isolate W5. Imazalil accumulation at pH 5 and 6 was similar. Isolate E300–3 also accumulated less fenarimol as compared with the wild-type isolate. This difference was much more obvious than for imazalil and was observed at all pH values tested. Differences in accumulation of both imazalil and fenarimol between low (E300–3), medium (H17) and high resistant (I33) isolates were not observed. These results suggest that decreased accumulation of DMIs is responsible for a low level of resistance only and that additional mechanisms of resistance might operate in isolates with a medium and high degree of resistance. With all isolates fenarimol accumulation was energy-dependent. This was not obvious for imazalil.The wild-type and DMI-resistant isolates had a similar plasma membrane potential as determined with the probe [14C]tetraphenylphosphonium bromide ([14C]TPP+). Various test compounds, among which ATPase inhibitors, ionophoric antibiotics and calmodulin antagonists, affected the accumulation of [14C]TPP+, [14C]imazalil and [14C]fenarimol. No obvious correlation between the effects of the test compounds on accumulation levels of the fungicides and [14C]TPP+ could be observed. These results indicate that the plasma membrane potential does not mediate the efflux of DMI fungicides byP. italicum. 相似文献
7.
AIM:To investigate the effects of milrinone (a selective phosphdiesterase III inhibitor PDE3) on insulin secretion, blood glucose, plasma free fatty acids (FFA) and dose-response relationship, and assess possible effects of milrinone on glucose metabolism and insulin sensitivity in conscious rats.METHODS:The catheterized nonstressed rats were administered by the varying doses of milrinone (1, 5, 25 μmol/kg) and were compared with controls. A hyperinsulinaemic- euglycaemic clamp was established in awake rats, and milrinone(25 μmol/kg) and 25% dimethyl sulfoxide (DMSO, as a control) were given at 120 min during hyperinsulinaemic- euglycaemic clamp. Glucose turnover was decided by gas chromatograph mass spectrometer (GC-MS).RESULTS:After dosing, plasma FFA levels in 3 milrinone groups significantly increased compared with the controls and before dosing. The percentages of elevation of FFA by the different milrinone doses were very similar, 50%, 52%, 55% for 1, 5, 25 μmol/kg respectively at 2 min after dosing. Plasma insulin levels were significantly elevated in the 5 and 25 μmol/kg groups, and the effect of milrinone on glucose concentration was detectable only 25 μmol/kg group. During hyperinsulinaemic clamp, there were significant increase in plasma FFA (from 173.1±15.2 to 633.8±87.3 μEq/L) and hepatic glucose production (HGP), and a significant decrease in glucose infusion rates (GIR) (to about 21%).CONCLUSION:These data suggest that milrinone impaires the abilities of insulin to suppress lipolysis and HGP, and insulin-mediated glucose utilization in peripheral tissue. Therefore, milrinone administration may induce an acute insulin resistancein vivo. 相似文献
8.
微管、微丝特异性抑制剂处理对水稻抗病性的影响 总被引:3,自引:0,他引:3
微管特异性抑制剂oryzalin、微丝特异性抑制剂细胞松弛素A (cytochalasin A,CA)和细胞松弛素D (cytochalasin D,CD)的试验表明:oryzalin在5~50μmol/L、CA在0.5~1.0μg/mL、CD在1~20μg/mL的浓度范围内,对稻瘟病菌孢子的萌发和附着胞的形成基本上没有影响。采用以上几种细胞骨架特异性抑制剂处理水稻叶鞘都可以不同程度地抑制寄主细胞抗病菌扩展的能力。在抑制剂处理的水稻叶鞘细胞中,病菌扩展的速度加快。进一步的观察发现,抑制剂处理抑制水稻细胞抗病菌的扩展能力与水稻的抗病防卫反应如原生质颗粒化、多酚类物质的积累和HR发生的延迟是相关的。 相似文献
9.
10.
V Kati L Scarabel D Thiery‐Lanfranchi V Kioleoglou S Liberopoulou C Dlye 《Weed Research》2019,59(5):367-376
The issue of cross‐ or multiple resistance to acetolactate synthase (ALS) inhibitors and the auxinic herbicide 2,4‐D was investigated in Papaver rhoeas L., a common and troublesome weed in winter cereals, in a broad‐scale study across four European countries. A combination of herbicide sensitivity bioassays and molecular assays targeting mutations involved in resistance was conducted on 27 populations of P. rhoeas originating from Greece (9), Italy (5), France (10) and Spain (3). Plants resistant to the field rate of 2,4‐D were observed in 25 of the 27 populations assayed, in frequencies ranging from 5% to 85%. Plants resistant to ALS‐inhibiting herbicides (sulfonylureas) were present in 24 of the 27 populations, in frequencies ranging from 4% to 100%. Plants resistant to 2,4‐D co‐occurred with plants resistant to sulfonylureas in 23 populations. In four of these, the probability of presence of plants with cross‐ or multiple resistance to 2,4‐D and sulfonylureas was higher than 0.5. ALS genotyping of plants from the field populations or of their progenies, identified ALS alleles carrying a mutation at codon Pro197 or Trp574 in 2,4‐D‐sensitive and in 2,4‐D‐resistant plants. The latter case confirmed multiple resistance to 2,4‐D and ALS inhibitors at the level of individual plants in all four countries investigated. This study is the first to identify individual plants with multiple resistance in P. rhoeas, an attribute rarely assessed in other weed species, but one with significant implications in designing chemical control strategies. 相似文献