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911.
Gregory I. Holwell Olga Kazakova Felicity Evans James C. O’Hanlon Katherine L. Barry 《PloS one》2015,10(6)
Genital asymmetry is relatively common and widespread throughout the animal kingdom. The functional significance of genital asymmetry is however, poorly understood for most species. Male praying mantids of the genus Ciulfina are remarkable in possessing complex and directionally asymmetric genital phallomeres in some species, and chirally dimorphic/antisymmetric genitalia in others. Here we explore the chiral dimorphism in male genitalia of Ciulfina baldersoni which appear to exhibit genital antisymmetry. We test whether genital orientation influences mating success, copulation duration and the attachment duration of spermatophores. Additionally we investigate genital interactions between male and females using x-ray micro-computed tomography (micro-CT) and scanning electron microscopy (SEM). Lastly we assess whether genital asymmetry is associated with non-genital morphological asymmetry of a range of traits. Our results highlight the complex functional morphology of genitalia in this praying mantis species and yet demonstrate no functional difference between dextral and sinistral morphs other than the direction of attachment with both morphs enjoying equal levels of mating success. Chiral morphs also did not strongly associate with any other forms of asymmetry. We therefore conclude that genital chirality in Ciulfina baldersoni is a likely case of antisymmetry with no functional significance to genital orientation, and is likely to be selectively neutral. 相似文献
912.
Bertova A Cacanyiova S Kristek F Krizanova O Ondrias K Tomaskova Z 《General physiology and biophysics》2010,29(4):402-410
As a part of the nitroso signalling pathway, nitroso-compounds serve as stores and carriers of NO; as part of the sulphide signalling pathway, bound sulfane-sulphur compounds serve as stores and carriers of H2S. Here we hypothesise a coupled sulphide-nitroso signalling pathway, in which H2S plays a main role. H2S releases NO from the endogenous S-nitroso-compounds nitroso-cysteine, nitroso-acetylcysteine and nitroso-albumin. Relaxation of noradrenaline-precontracted aortic rings by H2S is also enhanced in the presence of nitroso-albumin, which may implicate the involvement of the nitroso signalling pathway. Pretreatment of albumin, cysteine, N-acetylcysteine and lipids with H2S results in binding of sulphur to these compounds creating thus new-modified sulphur compounds that release NO from nitroso-compounds directly and/or through released H2S, which suggests sulphide-nitroso signalling pathway participation. This hypothesis is supported by the observation that the pretreatment of noradrenaline-precontracted aortic rings with H2S significantly enhanced relaxation induced by nitroso-glutathione in the absence of H2S. We assume that the NO release from nitroso-compounds directly by H2S or indirectly by the H2S-induced sulphur-bound compounds represents coupled sulphide-nitroso signalling, which may explain some of the numerous biological effects of H2S that are shared with NO. 相似文献
913.
Although there is evidence suggesting that statins may exert an endothelial protecting effect, recent in vitro data have shown that these compounds may induce endothelial cells (EC) apoptosis. We previously reported that the Fas-death receptor may induce apoptosis of the liver sinusoid endothelial cells (LSEC), and that TNF-α increases the susceptibility of these cells to suffer Fas-mediated apoptosis. Based on this evidence, in this study, we investigated the effect of simvastatin on Fas-mediated LSEC apoptosis. Simvastatin induced a significant reduction in LSEC viability, in a dose dependent manner, under serum-containing or serum-free conditions. This effect was prevented by mevalonate and GGPP, indicating the role of hydroxy-3-methylglutaryl-CoA reductase. The simvastatin effect on LSEC death was not associated with increased activation of caspase-3. We found that simvastatin increased the susceptibility of LSEC death mediated by Fas. Further, simvastatin increased LSEC-apoptosis induced by Fas and TNF-α. Mevalonate and GGPP partially prevented simvastatin-induced sensitization to LSEC death mediated by Jo2 and TNF-α, but not Jo2 alone. Simvastatin did not induce up-regulation of the Fas on the LSEC. Our results provide evidence of simvastatin in modulating Fas-mediated apoptosis in endothelial cells. These results may have clinical implications in those clinical conditions associated with high levels of FasL and TNF-α. 相似文献
914.
A multiharmonic cubic-nonlinear theory of a plasma-beam superheterodyne free-electron laser of the dopplertron type is constructed.
A retarded electromagnetic wave propagating in the magnetized plasma-beam system toward the electron beam is used for pumping.
The multiharmonic interaction of waves which plays an important role is taken into account. Saturation levels and mechanisms
are analyzed. The promising application of such systems for generating high-power electromagnetic radiation in the millimeter
wavelength range is demonstrated. 相似文献
915.
Rando Tuvikene Kalle Truus Marju Robal Olga Volobujeva Enn Mellikov Tõnis Pehk Andres Kollist Tiiu Kailas Merike Vaher 《Journal of applied phycology》2010,22(1):51-63
The structure and composition of galactan from Furcellaria lumbricalis (furcellaran) were investigated in connection with rheological specificities, gel structure, and extraction conditions. The
polysaccharide was characterized by 13C nuclear magnetic resonance (13C-NMR) and Fourier transform infrared spectroscopy, inductively coupled plasma-optical emission spectrometry, electrothermal
atomization atomic absorption spectrometry, and gel permeation chromatography methods. The microstructure of polymer gels
was studied using a cryofixation method in combination with freeze-drying and scanning electron microscopy (SEM) techniques.
The undersulfated furcellaran backbone consists mainly of 3,6-anhydro-d-galactose (28.5–30.1%) and galactose residues, the latter being partly sulfated in positions 4 and 6, which give rise to
some specific properties of the gel. Also, residues of 6-O-methyl-d-galactose as a minor component are found to be present. The water-extracted furcellaran with the average molecular weight
about 290 kDa is rich in nitrogen, calcium, magnesium, and potassium, while the sodium content is rather low. The low sulfur
content (5.3%) and 13C-NMR spectra refer to an undersulfated nature of this galactan. The extraction of seaweeds in low concentration alkaline
solutions (instead of water) leads to a significant increase of the minimum size of the galactan particles and the value of
gel strength (more than 12 times for Rb-containing gels). The properties of the gel are dependent on specific tentacle-like
structure units present in furcellaran gels established by a high-resolution SEM. 相似文献
916.
Gábor Wágner Csaba Wéber Olga Nyéki Katalin Nógrádi Attila Bielik László Molnár Amrita Bobok Attila Horváth Béla Kiss Sándor Kolok József Nagy Dalma Kurkó Krisztina Gál István Greiner Zsolt Szombathelyi György M. Keserű György Domány 《Bioorganic & medicinal chemistry letters》2010,20(12):3737-3741
Here we report the discovery and early SAR of a series of mGluR5 negative allosteric modulators (NAMs). Starting from a moderately active HTS hit we synthesized 3,5-disubstituted-oxadiazoles and tetrazoles as mGluR5 NAMs. Based on the analysis of ligand efficiency and lipophilic efficiency metrics we identified a promising lead candidate as a starting point for further optimization. 相似文献
917.
918.
919.
Leroi V. DeSouza Olga Krakovska Marlene M. Darfler David B. Krizman Alexander D. Romaschin Terence J. Colgan K. W. Michael Siu 《Proteomics》2010,10(17):3108-3116
Formalin‐fixed paraffin‐embedded (FFPE) tissues are the primary and preferred medium for archiving patients' samples. Here we demonstrate relative quantifications of protein biomarkers in extracts of laser microdissected epithelial cells from FFPE endometrial carcinoma tissues versus those from normal proliferative endometria by means of targeted proteomic analyses using LC–multiple reaction monitoring (MRM) MS with MRM Tags for Relative and Absolute Quantitation (mTRAQ) labeling. Comparable results of differential expressions for pyruvate kinase isoform M2 (PK‐M2) and polymeric Ig receptor were observed between analyses on laser microdissected epithelial cells from FFPE tissues and corresponding homogenates from frozen tissues of the same individuals that had previously been analyzed and reported. We also identified PK‐M2 in the normal proliferative phase of the endometrium. Other biomarkers in addition to PK‐M2 and polymeric Ig receptor were also observed but not consistently and/or were at levels below the threshold for quantification. 相似文献
920.
Along with a brief review of Lentinula edodes (shiitake mushroom) submerged cultivation history within the framework of important extracellular proteins biosynthesis, this study contains the authors’ own results. The possibility of regulating the lectin activity of shiitake using the synthetic components is shown. The time course of lectin production in culture liquid of L. edodes in different media under submerged culture conditions was studied. The activity of agglutinins depended on the ratio between carbon and nitrogen sources and the pH of the culture medium. A relationship between the chemical composition of nutrient medium, the activity of extracellular lectins of L. edodes, and the formation of pigmented mycelial film in liquid culture has been found. The formulation of medium, on which the brown mycelial film appears in several days of submerged cultivation, is proposed. The results obtained make a contribution to the present notion of biochemical processes that give rise to the occurrence of the aforesaid morphological structure of shiitake. Finally, two extracellular lectins from the submerged culture of L. edodes have been isolated and purified to homogeneity. Their physicochemical properties and composition have been studied. 相似文献