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991.
Synthesis of macrocyclic di, tetra- and hexaamides with aza and oxy linkages has been achieved and the inhibitory activity of cyclophane amides against human pathogenic bacteria well documented. 相似文献
992.
土壤中铁锰的形态分布及其有效性研究 总被引:14,自引:0,他引:14
以乌鲁木齐雅马里克山的土壤为研究对象,采用Tessier连续提取法对土壤铁、锰各种化学形态进行浸提.研究了土壤中有效铁、锰和土壤的理化性质与土壤铁、锰形态之间的关系,及对铁、锰在土壤中存在形态的影响;并通过盆栽试验对铁、锰的植物有效性进行了分析.结果表明,土壤铁主要以残渣态为主,占全铁的92.3%,其它形态含量均小于全量的8%.土壤锰主要是以铁锰氧化态和残渣态为主,分别占全锰的49%和41.6%,其它形态含量均小于全量的10%.用二级出水灌溉处理可增加铁、锰的有效性,原污水灌溉不利于铁、锰的供应,土壤缺铁、锰的现象可通过施加一定量的铁盐和锰盐而得以改善.相关分析还表明,土壤的理化性质与铁锰形态之间有一定的相关性.供试土壤的pH值、CaCO3含量、有机质及阳离子交换态等对土壤铁、锰的有效性影响较大.逐步回归分析表明,铁的氧化物结合态对植物最为有效,锰的有机结合态对植物有效性贡献最大. 相似文献
993.
994.
Roquia Rizk Mesfin Alameraw Mohamed Ali Rawash Tatjna Juzsakova Endre Domokos Amor Hedfi Mohammed Almalki Fehmi Boufahja Plavan Gabriel Hesham M. Shafik kos Rdey 《Saudi Journal of Biological Sciences》2021,28(9):5250-5260
In order to maintain a good environmental status of surface waters, an assessment of water quality carried out at specific intervals to monitor the changes of water quality in function of time. Human knowledge and experience are currently focused on using assessment methods, especially the integration of multiple constraining factors and considering them in conjugation with the correct decision-making process concerning the environment. When surface water is highly exposed to human activities, either from recreational or economic activity, the degree of vulnerability is high, and the quality of surface water is highly compromised. In case of Lake Balaton, there are many activities that can disrupt water dynamics. The first goal of this study is to determine the location of the least and most polluted sites around Lake Balaton. The processing of data was carried out by using multi-criteria decision techniques and environmental impact assessment method based on physical–chemical parameters in comparison with the limiting parameters. Based on the results of those methods water quality needs to be improved in western parts of the lake by using several geoengineering treatment techniques. This work covers a novel approach to comparing methods based on sum of ranking differences, whereas many method comparison studies suffer from ambiguity or from comparisons not being quite fair. This problem can be avoided if there are differences between ideal and actual rankings. 相似文献
995.
Kaschani F Shabab M Bozkurt T Shindo T Schornack S Gu C Ilyas M Win J Kamoun S van der Hoorn RA 《Plant physiology》2010,154(4):1794-1804
Since the leaf apoplast is a primary habitat for many plant pathogens, apoplastic proteins are potent, ancient targets for apoplastic effectors secreted by plant pathogens. So far, however, only a few apoplastic effector targets have been identified and characterized. Here, we discovered that the papain-like cysteine protease C14 is a new common target of EPIC1 and EPIC2B, two apoplastic, cystatin-like proteins secreted by the potato (Solanum tuberosum) late blight pathogen Phytophthora infestans. C14 is a secreted protease of tomato (Solanum lycopersicum) and potato typified by a carboxyl-terminal granulin domain. The EPIC-C14 interaction occurs at a wide pH range and is stronger than the previously described interactions of EPICs with tomato defense proteases PIP1 and RCR3. The selectivity of the EPICs is also different when compared with the AVR2 effector of the fungal tomato pathogen Cladosporium fulvum, which targets PIP1 and RCR3, and only at apoplastic pH. Importantly, silencing of C14 increased susceptibility to P. infestans, demonstrating that this protease plays a role in pathogen defense. Although C14 is under conservative selection in tomato, it is under diversifying selection in wild potato species (Solanum demissum, Solanum verrucosum, and Solanum stoliniferum) that are the natural hosts of P. infestans. These data reveal a novel effector target in the apoplast that contributes to immunity and is under diversifying selection, but only in the natural host of the pathogen. 相似文献
996.
Samreen Kazi J. Shultz J. Afzal Rizwan Hashmi Mohammed Jasim Jason Bond Prakash R. Arelli David A. Lightfoot 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,120(3):633-644
Soybean [Glycine max (L.) Merr.] cultivars varied in their resistance to different populations of the soybean cyst nematode (SCN), Heterodera glycines, called HG Types. The rhg1 locus on linkage group G was necessary for resistance to all HG types. However, the loci for resistance to H. glycines HG Type 1.3- (race 14) and HG Type 1.2.5- (race 2) of the soybean cyst nematode have varied in their reported locations.
The aims were to compare the inheritance of resistance to three nematode HG Types in a population segregating for resistance
to SCN and to identify the underlying quantitative trait loci (QTL). ‘Hartwig’, a soybean cultivar resistant to most SCN HG
Types, was crossed with the susceptible cultivar ‘Flyer’. A total of 92 F5-derived recombinant inbred lines (RILs; or inbred
lines) and 144 molecular markers were used for map development. The rhg1 associated QTL found in earlier studies were confirmed and shown to underlie resistance to all three HG Types in RILs (Satt309;
HG Type 0, P = 0.0001 R
2 = 22%; Satt275; HG Type 1.3, P = 0.001, R
2 = 14%) and near isogeneic lines (NILs; or iso-lines; Satt309; HG Type 1.2.5-, P = 0.001 R
2 = 24%). A new QTL underlying resistance to HG Type 1.2.5- was detected on LG D2 (Satt574; P = 0.001, R
2 = 11%) among 14 RILs resistant to the other HG types. The locus was confirmed in a small NIL population consisting of 60
plants of ten genotypes (P = 0.04). This QTL (cqSCN-005) is located in an interval previously associated with resistance to both SDS leaf scorch from
‘Pyramid’ and ‘Ripley’ (cqSDS-001) and SCN HG Type 1.3- from Hartwig and Pyramid. The QTL detected will allow marker assisted
selection for multigenic resistance to complex nematode populations in combination with sudden death syndrome resistance (SDS)
and other agronomic traits. 相似文献
997.
Aman B. Saleem Paul Chadderton John Apergis-Schoute Kenneth D. Harris Simon R. Schultz 《Journal of computational neuroscience》2010,29(1-2):49-62
During anesthesia, slow-wave sleep and quiet wakefulness, neuronal membrane potentials collectively switch between de- and hyperpolarized levels, the cortical UP and DOWN states. Previous studies have shown that these cortical UP/DOWN states affect the excitability of individual neurons in response to sensory stimuli, indicating that a significant amount of the trial-to-trial variability in neuronal responses can be attributed to ongoing fluctuations in network activity. However, as intracellular recordings are frequently not available, it is important to be able to estimate their occurrence purely from extracellular data. Here, we combine in vivo whole cell recordings from single neurons with multi-site extracellular microelectrode recordings, to quantify the performance of various approaches to predicting UP/DOWN states from the deep-layer local field potential (LFP). We find that UP/DOWN states in deep cortical layers of rat primary auditory cortex (A1) are predictable from the phase of LFP at low frequencies (< 4 Hz), and that the likelihood of a given state varies sinusoidally with the phase of LFP at these frequencies. We introduce a novel method of detecting cortical state by combining information concerning the phase of the LFP and ongoing multi-unit activity. 相似文献
998.
Fazel Shabanpoor Richard A. Hughes Suode Zhang Ross A. D. Bathgate Sharon Layfield Mohammed Akhter Hossain Geoffrey W. Tregear Frances Separovic John D. Wade 《Amino acids》2010,38(1):121-131
Insulin-like 3 (INSL3) is a novel circulating peptide hormone that is produced by testicular Leydig cells and ovarian thecal
and luteal cells. In males, INSL3 is responsible for testicular descent during foetal life and suppresses germ cell apoptosis
in adult males, whereas in females, it causes oocyte maturation. Antagonists of INSL3 thus have significant potential clinical
application as contraceptives in both males and females. Previous work has shown that the INSL3 receptor binding region is
largely confined to the B-chain central α-helix of the hormone and a conformationally constrained analogue of this has modest
receptor binding and INSL3 antagonist activity. In the present study, we have employed and evaluated several approaches for
increasing the α-helicity of this peptide in order to better present the key receptor binding residues and increase its affinity
for the receptor. Analogues of INSL3 with higher α-helicity generally had higher receptor binding affinity although other
structural considerations limit their effectiveness. 相似文献
999.
Sumra Afzal Mahjabeen Saleem Riffat Yasmin Mamoona Naz Muhammad Imran 《Molecular biology reports》2010,37(4):1717-1723
Consistent with its precloning characterization from the cellulolytic Bacillus sp., β-1,4-endoglucanase purified from the recombinant E. coli exhibited maximum activity at 60°C and pH 7.0. It was highly specific for CMC hydrolysis, with stability up to 70°C and over
a pH range of 6.0–8.0. The K
m and V
max values for CMCase activity of the enzyme were 4.1 mg/ml and 25 μmole/ml min−1, respectively. The purified enzyme was a monomer of 65 kDa, as determined by SDS-PAGE. The presence of sucrose and IPTG in
fermentation media increased the endoglucanase activity of the recombinant enzyme to 5.2-folds as compared with that of the
actual one. 相似文献
1000.
Ashraf M.A. Mashaly Ashraf M. Ahmed Mohammed S. Al-Khalifa Túlio M. Nunes E. David Morgan 《Biochemical Systematics and Ecology》2010
The major volatile compounds in the poison glands of two Monomorium ant species from Saudi Arabia have been identified. Monomorium niloticum and Monomorium najrane both contain mixtures of alkyl- and alkenyl-pyrrolidines and -pyrrolines in their venom glands but no Dufour gland volatile compounds were detected. Monomorium mayri showed neither Dufour gland compounds nor venom components detectable by gas chromatography. 相似文献