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A. Korte I. Ribera R. G. Beutel D. Bernhard 《Journal of Zoological Systematics and Evolutionary Research》2004,42(4):281-288
The series Staphyliniformia is one of the mega‐diverse groups of Coleoptera, but the relationships among the main families are still poorly understood. In this paper we address the interrelationships of staphyliniform groups, with special emphasis on Hydrophiloidea and Hydraenidae, based on partial sequences of the ribosomal genes 18S rDNA and 28S rDNA. Sequence data were analysed with parsimony and Bayesian posterior probabilities, in an attempt to overcome the likely effect of some branches longer than the 95% cumulative probability of the estimated normal distribution of the path lengths of the species. The inter‐family relationships in the trees obtained with both methods were in general poorly supported, although most of the results based on the sequence data are in good agreement with morphological studies. In none of our analyses a close relationship between Hydraenidae and Hydrophiloidea was supported, contrary to the traditional view but in agreement with recent morphological investigations. Hydraenidae form a clade with Ptiliidae and Scydmaenidae in the tree obtained with Bayesian probabilities, but are placed as basal group of Staphyliniformia (with Silphidae as subordinate group) in the parsimony tree. Based on the analysed data with a limited set of outgroups Scarabaeoidea are nested within Staphyliniformia. However, this needs further support. Hydrophiloidea s.str., Sphaeridiinae, Histeroidea (Histeridae + Sphaeritidae), and all staphylinoid families included are confirmed as monophyletic, with the exception of Hydraenidae in the parsimony tree. Spercheidae are not a basal group within Hydrophiloidea, as has been previously suggested, but included in a polytomy with other Hydrophilidae in the Bayesian analyses, or its sistergroup (with the inclusion of Epimetopidae) in the parsimony tree. Helophorus is placed at the base of Hydrophiloidea in the parsimony tree. The monophyly of Hydrophiloidea s.l. (including the histeroid families) and Staphylinoidea could not be confirmed by the analysed data. Some results, such as a placement of Silphidae as subordinate group of Hydraenidae (parsimony tree), or a sistergroup relationship between Ptiliidae and Scydmaenidae, appear unlikely from a morphological point of view. 相似文献
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Nanoporous alumina membranes were silanized with aminopropylsilane and iminodiacetic acid (IDA) groups were generated in situ by reaction with iodoacetate. The membranes were mounted in standard filter holders, connected to a HPLC system and saturated with selected metal ions. Cu(II) allowed the capture of chicken muscle lactate dehydrogenase with such stability, repeatability and reproducibility that Michaelis–Menten kinetics could be studied. The IDA surface was stable for months and could be depleted and regenerated with metal ions multiple times without appreciable loss of capacity. The binding of lactate dehydrogenase influenced the backpressure to the extent that could be expected for a monolayer according to Poiseuilles law. 相似文献
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Amira Alkharusi Elena Lesma Silvia Ancona Eloisa Chiaramonte Thomas Nystr?m Alfredo Gorio Gunnar Norstedt 《PloS one》2016,11(1)
Pulmonary lymphangioleiomyomatosis (LAM) is a rare lung disease caused by mutations in the tumor suppressor genes encoding Tuberous Sclerosis Complex (TSC) 1 and TSC2. The protein product of the TSC2 gene is a well-known suppressor of the mTOR pathway. Emerging evidence suggests that the pituitary hormone prolactin (Prl) has both endocrine and paracrine modes of action. Here, we have investigated components of the Prl system in models for LAM. In a TSC2 (+/-) mouse sarcoma cell line, down-regulation of TSC2 using siRNA resulted in increased levels of the Prl receptor. In human LAM cells, the Prl receptor is detectable by immunohistochemistry, and the expression of Prl in these cells stimulates STAT3 and Erk phosphorylation, as well as proliferation. A high affinity Prl receptor antagonist consisting of Prl with four amino acid substitutions reduced phosphorylation of STAT3 and Erk. Antagonist treatment further reduced the proliferative and invasive properties of LAM cells. In histological sections from LAM patients, Prl receptor immuno reactivity was observed. We conclude that the Prl receptor is expressed in LAM, and that loss of TSC2 increases Prl receptor levels. It is proposed that Prl exerts growth-stimulatory effects on LAM cells, and that antagonizing the Prl receptor can block such effects. 相似文献
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Ana Isabell Paulino Aud Larsen Gunnar Bratbak Dale Evens Svein Rune Erga Einar Bye-Ingebrigtsen 《Marine Biology Research》2018,14(5):421-435
Changes in phytoplankton community composition potentially affect the entire marine food web. Because of seasonal cycles and inter-annual variations in species composition, long-term monitoring, covering many sequential years, is required to establish a baseline study and to reveal long-term trends. The current study describes the phytoplankton biomass variations and species composition in relation to hydrographic and meteorological conditions in the Raunefjord, western Norway, over a 6-year period from 2001 to 2006. The extent of inflow or upwelling in the fjord varied from year to year and resulted in pronounced differences in water column stability. The annual phytoplankton community succession showed some repeated seasonal patterns, but also high variability between years. Two to four diatom blooms were observed per year, and the spring blooms occurring before water column stratification in March were dominated by Skeletonema marinoi and Chaetoceros socialis, and other Chaetoceros and Thalassiosira spp. Blooms of the haptophytes Phaeocystis pouchetii and Emiliania huxleyi were irregular and in some years totally absent. Although E. huxleyi was present all year round it appeared in bloom concentrations only in 2003, when the summer was warm and the water column characterized by high surface temperatures and pronounced stratification. The annual average abundance of both diatoms and flagellates increased during the six years. Despite the high variation from year to year, our investigation provides valuable knowledge about annual phytoplankton community patterns in the region, and can be used as a reference to detect possible future changes. 相似文献
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Prostaglandin E2-9- oxoreductase (PGE2-9-OR), the enzyme which converts prostaglandin E2 (PGE2) to prostaglandin F2 alpha (PGF2 alpha), has been detected in human decidua vera. A 105-fold purification was achieved when the centrifuged homogenate was fractionated sequentially by DEAE-Trisacryl, hydroxyapatite-agarose gel, ultrogel AcA 44 and Matrex gel blue A gel chromatographies. The following kinetic constants for PGE2-9-OR have been obtained. The equilibrium constant with respect to PGE2 is 83 microM, the Michaelis constant, Km, for PGE2 is 80 microM, for NADPH 1.6 microM. The maximal velocity for the forward reaction is V1 = .203 pmol/min. The enzyme was inhibited by progesterone, oestradiol-17 beta, cortisol and pharmaceutical drugs. An activating effect could be demonstrated with Ca2+ and oxytocin. The occurrence of PGE2-9-OR in the decidua vera suggests that this enzyme may be responsible for the transformation of PGE2 to PGF2 alpha in these tissues. This may be an important mechanism for the initiation and maintenance of uterine contractions. 相似文献
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G Gluth D Freitag W Hanke F Korte 《Comp. Biochem. Physiol. C, Comp. Pharmacol. Toxicol.》1985,81(2):273-277
The amount of radioactivity which derived from 14C-labeled pollutants was determined in liver, kidney, intestine, blood, muscle and gills of carp, exposed for 6, 24 and 72 hr to high external concentrations of urea, methanol, atrazine and PCP. The results allowed one to calculate roughly the uptake rate for these compounds. It was low for urea (0.055 micrograms/g per hr), higher for methanol (0.12) and atrazine (0.16) and highest for PCP (1.5). The bioaccumulation factors (BFs) were determined for the different substances and organs. They correlated with the hydrophilic-lipophilic nature of the chemicals. The more lipophilic the substances the more accumulation occurred in the liver. PCP accumulated the most. BF was 300-400 in most tissues except muscle where it was quite low. The BF was 3-4 for atrazine in liver, kidney and intestine, but just 1 in blood, muscle and gills. There is some evidence that the BF for methanol equals 1 in liver, kidney, gills and intestine. It is less than 1 in blood and muscle. Urea was equally distributed in all organs and in the external medium. 相似文献
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