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991.
Xu Yu Chen Yao Dong Qi Jian He Wei Zheng Zhang De Li Wang Jin Dong Feng Bing Chun Gan 《World journal of microbiology & biotechnology》2011,27(3):495-503
Fifty-two endophytic fungi strains with different colony morphologies were isolated from stems, leaves and roots of Huperzia serrata (Thunb. ex Murray) Trevis. collected from Bawangling Reserve of Hainan Province in southern China. They were identified mainly
based on rDNA ITS sequences and phylogenetic analysis. The results showed that all strains belonged to four classes, i.e.
Sordariomycetes (92.31%), Dothideomycetes (3.85%), Pezizomycetes (1.92%) and Agaricomycetes (1.92%). Forty-seven strains were identified at the genus level, including Glomerella (Colletotrichum), Hypocrea (Trichoderma), Pleurostoma, Chaetomium, Coniochaeta (Lecythophora), Daldinia, Xylaria, Hypoxylon,
Nodulisporium, Cazia and Phellinus. As to the other five strains, three were identified at the order level and two at the family level, indicating that a great
diversity of fungi taxa exists in H. serrata. Most isolated strains belonged to the genus of Glomerella (Colletotrichum) and Hypoxylon, twenty-one from Glomerella and its anamorph Colletotrichum (42.3% of total isolated strains) and ten from Hypoxylon (19.2% of total isolated strains). Pleurostoma, Chaetomium, Coniochaeta (Lecythophora), Daldinia, Xylaria, Hypoxylon,
Nodulisporium, Cazia and Phellinus were reported as endophytic fungi isolated from H. serrata for the first time. 相似文献
992.
The aggregation of soluble proteins into fibrillar species is a complex process that spans many lengths and time scales, and that involves the formation of numerous on-pathway and off-pathway intermediate species. Despite this complexity, several elements underlying the aggregation process appear to be universal. The kinetics typically follows a nucleation-growth process, and proteins with very different sequences aggregate to form similar fibril structures, populating intermediates with sufficient structural similarity to bind to a common antibody. This review focuses on a computational approach that exploits the common features of aggregation to simplify or 'coarse-grain' the representation of the protein. We highlight recent developments in coarse-grained modeling and illustrate how these models have been able to shed new light into the mechanisms of protein aggregation and the nature of aggregation intermediates. The roles of aggregation prone conformations in the monomeric state and the influence of inherent β-sheet and aggregation propensities in modulating aggregation pathways are discussed. 相似文献
993.
Microtopography is one of several strategies used by marine organisms to inhibit colonization by fouling organisms. While replicates of natural microtextures discourage settlement, details of larval interactions with the structured surfaces remain scarce. Close-range microscopy was used to quantify the exploration of cyprids of Amphibalanus amphitrite on cylindrical micropillars with heights of 5 and 30 μm and diameters ranging from 5 to 100 μm. While 5 μm-high structures had little impact, 30 μm-high pillars significantly influenced cyprid exploration. An observed step length decrease and step duration increase on 5 μm diameter pillars is attributed to the small dimensions of the voids excluding the cyprid's attachment disc and consequently reducing the area of adhesive contact. When exploring larger diameter pillars, cyprids preferred using the voids to form temporary attachment points. This may enhance their resistance to flow. No-choice assay settlement patterns mirrored this exploration behaviour, albeit in a pattern counter to what was predicted. 相似文献
994.
Attention and memory are typically studied as separate topics, but they are highly intertwined. Here we discuss the relation between memory and two fundamental types of attention: perceptual and reflective. Memory is the persisting consequence of cognitive activities initiated by and/or focused on external information from the environment (perceptual attention) and initiated by and/or focused on internal mental representations (reflective attention). We consider three key questions for advancing a cognitive neuroscience of attention and memory: to what extent do perception and reflection share representational areas? To what extent are the control processes that select, maintain, and manipulate perceptual and reflective information subserved by common areas and networks? During perception and reflection, to what extent are common areas responsible for binding features together to create complex, episodic memories and for reviving them later? Considering similarities and differences in perceptual and reflective attention helps integrate a broad range of findings and raises important unresolved issues. 相似文献
995.
Reinforcements and punishments facilitate adaptive behavior in diverse domains ranging from perception to social interactions. A conventional approach to understanding the corresponding neural substrates focuses on the basal ganglia and its dopaminergic projections. Here, we show that reinforcement and?punishment signals are surprisingly ubiquitous in the gray matter of nearly every subdivision of the?human brain. Humans played either matching-pennies or rock-paper-scissors games against computerized opponents while being scanned using fMRI. Multivoxel pattern analysis was used to decode previous choices and their outcomes, and to predict upcoming choices. Whereas choices were decodable from a confined set of brain structures, their outcomes were decodable from nearly all cortical and subcortical structures. In addition, signals related to both reinforcements and punishments were recovered reliably in many areas and displayed patterns not consistent with salience-based explanations. Thus, reinforcement and punishment might play global modulatory roles in the entire brain. 相似文献
996.
Degumming of vegetable oils by a novel phospholipase B from Pseudomonas fluorescens BIT-18 总被引:2,自引:0,他引:2
Pseudomonas fluorescens BIT-18 was isolated from soil near a vegetable oil factory and shown to produce a B-type phospholipase. The enzyme was partially purified by ammonium sulfate precipitation. Gas chromatography demonstrated that the enzyme preparation hydrolyzed both the 1- and 2-ester bonds of phosphatidylcholine. When degumming of soybean, rapeseed, and peanut oil was performed with this enzyme preparation, oils with phosphorous contents lower than 5 mg/kg were obtained after 5 h of enzyme treatment at 40 °C. The enzyme preparation did not show lipase activity, thus free fatty acids were only generated from the phospholipids. Therefore, this novel phospholipase B is potentially useful for the refining of high-quality oils with attractive yields. 相似文献
997.
Jin-Young Kim Seong-Cheol Park Moon-Young Yoon Kyung-Soo Hahm Yoonkyung Park 《Amino acids》2011,40(1):183-195
PMAP-23 is a member of the cathelicidin family derived from pig myeloid cells and has potent antimicrobial activity. Amidation
of the carboxyl terminus (C-terminus) of an antimicrobial peptide generally enhances its structural stability and antimicrobial
activity or decreases its cytotoxicity. The aim of the present study was to investigate the effect of amidation on the mode
of action in PMAP-23. Irrespective of amidation, PMAP-23 adopts a helix–hinge–helix structure in a membrane-mimetic environment.
The antibacterial activities of PMAP-23C, which had a free C-terminus, and PMAP-23N, which had an amidated C-terminus, were
similar against Gram-negative bacteria, reflecting a similar ability to neutralize lipopolysaccharide. However, PMAP-23N assumed
a perpendicular orientation across the outer to the inner leaflet of the bacterial inner membrane, while PMAP-23C was orientated
parallel to the lipid bilayer, as determined by following the blue shift in tryptophan fluorescence, as well as calcein release
from liposomes and SYTOX Green uptake assays. These results suggest that N-terminal amidation of PMAP-23 provides structural
stability and increases the peptide’s cationic charge, facilitating translocation into the bacterial inner membrane. 相似文献
998.
Yun EY Hwang JS Yoon YI Ahn MY Kim NJ Kwon OY Lee WJ Goo TW 《Archives of insect biochemistry and physiology》2011,77(3):145-162
To examine the expression profile of oxidative stress responsive genes in Spodoptera litura, we constructed a cDNA library from S. litura injected with hydrogen peroxide (H(2)O(2)). Using a microarray chip composed of 2,964 cDNAs, we screened gene expression at 1, 3, 5, 7, and 9 h post H(2)O(2) injection. Data were clustered into 15 groups of genes that behave similarly across each time course. Seventy-three genes were identified as being at least twofold up- or downregulated after treatment with H(2)O(2) in S. litura. We constructed expressed sequence tags (ESTs) for genes that changed at least twofold after treatment with H(2)O(2) . The functional classification of these ESTs based on Gene Ontology showed that the ESTs are rich in genes involved in oxidoreductase activity (5.7%), defense (14.3%), cellular process (22.9%), and development (17.1%). 相似文献
999.
Wu SC Yoon D Chin J van Kirk K Seethala R Golla R He B Harrity T Kunselman LK Morgan NN Ponticiello RP Taylor JR Zebo R Harper TW Li W Wang M Zhang L Sleczka BG Nayeem A Sheriff S Camac DM Morin PE Everlof JG Li YX Ferraro CA Kieltyka K Shou W Vath MB Zvyaga TA Gordon DA Robl JA 《Bioorganic & medicinal chemistry letters》2011,21(22):6693-6698
Derived from the HTS hit 1, a series of hydroxyisoquinolines was discovered as potent and selective 11β-HSD1 inhibitors with good cross species activity. Optimization of substituents at the 1 and 4 positions of the isoquinoline group in addition to the core modifications, with a special focus on enhancing metabolic stability and aqueous solubility, resulted in the identification of several compounds as potent advanced leads. 相似文献
1000.
Subramanyam C Duplantier AJ Dombroski MA Chang SP Gabel CA Whitney-Pickett C Perregaux DG Labasi JM Yoon K Shepard RM Fisher M 《Bioorganic & medicinal chemistry letters》2011,21(18):5475-5479
The discovery, of a series of 2-Cl-5-heteroaryl-benzamide antagonists of the P2X(7) receptor via parallel medicinal chemistry is described. Initial analogs suffered from poor metabolic stability and low Vd(ss). Multi parametric optimization led to identification of pyrazole 39 as a viable lead with excellent potency and oral bioavailability. Further attempts to improve the low Vd(ss) of 39 via introduction of amines led to analogs 40 and 41 which maintained the favorable pharmacology profile of 39 and improved Vd(ss) after iv dosing. But these analogs suffered from poor oral absorption, probably driven by poor permeability. 相似文献