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71.
Raúl Pérez-Ruiz Olga Hinze J?rg-M Neud?rfl Dirk Blunk Helmut G?rner Axel G Griesbeck 《Photochemical & photobiological sciences》2008,7(7):782-788
The solution photochemistry of the ortho allyloxy-substituted benzophenone has been investigated in detail. Product analysis revealed formation of a diastereomeric mixture of dihydrobenzofuran derivatives by cyclization via a short-lived intermediate 1,5-biradical and an unusual acetal by a pseudo-Paternò-Büchi rearrangement. The latter reaction pathway was supported by means of laser flash photolysis, where a long-lived intermediate with a maximum absorption band at 380 nm was observed. Besides, theoretical calculations (TD-DFT) of this UV-transient resulted in a band with maximum intensity at 390 nm showing a good correlation between experimental results and theoretical calculations. For comparison, the meta-substituent substrate was also investigated showing preferred triplet-triplet energy transfer. 相似文献
72.
Heidrun Janka Maria von Balthazar William S. Alverson David A. Baum João Semir Clemens Bayer 《Plant Systematics and Evolution》2008,275(1-2):69-91
Androecium development and vasculature were studied in nine species of the Adansonieae clade (core Bombacoideae, Malvaceae s.l.). In early androecium development either distinct pentagonal androecial ring walls or five common petal/androecium primordia are present. Ring walls give rise to five antepetalous and five alternipetalous primary androecial primordia. Common primordia divide into peripheral petal primordia and antepetalous primary androecial primordia. Antepetalous primary androecial primordia split anticlinally into ten primordia-halves, on which secondary androecial primordia are initiated in a centrifugal succession. Androecial lobes are formed by fusion of an alternipetalous primary androecial primordium and its two neighbouring antepetalous primary primordia-halves, a pattern that also occurs in other Malvatheca. Later, tertiary androecial primordia are formed by the subdivision of secondary androecial primordia (except in Adansonia and Ceiba). Each tertiary primordium differentiates into a two-locular androecial unit. At anthesis these two-locular androecial units are often present in pairs, corresponding to the two halves of the same secondary androecial primordium. Androecium development and vasculature imply that the alternipetalous androecial sectors have been reduced in Bombacoideae, a tendency that is shared with other subfamilies of Malvaceae. 相似文献
73.
von Wichert G Edenfeld T von Blume J Krisp H Krndija D Schmid H Oswald F Lother U Walther P Adler G Seufferlein T 《Cellular signalling》2008,20(5):925-934
Chromogranin A is a member of the granin family of acidic secretory glycoproteins that is found in secretory granules of many endocrine cells including neuroendocrine tumour cells. This hormone serves as a model system for autonomous hormone secretion by the so called functional neuroendocrine tumours of the gastrointestinal tract. The precise regulation of chromogranin secretion at the level of the Golgi apparatus is a subject of intense research. The protein kinase D (PKD) family of serine threonine kinases has so far been implicated in the regulation of constitutive secretion in epithelial cells. Here we examined whether PKD2 expression and activity could also play a role in the release of secretory granules from the trans Golgi network (TGN) in neuroendocrine tumour cells and hence be a target to block autonomous secretion by these tumours. Our data show that expression and catalytic activity of PKD2 are required for the release of chromogranin A containing secretory vesicles. Inhibition of PKD2 activity or siRNA knockdown of PKD2 resulted in a marked perinuclear retention of chromogranin A immunofluorescence in the trans Golgi network and led to a marked reduction in basal as well as phorbol ester stimulated secretion of chromogranin A into the supernatant of cells. Thus, PKD2 controls the release of secretory granules in neuroendocrine tumour cells at the level of the Golgi apparatus and could hence serve as a novel target to block hormone secretion in functional neuroendocrine tumours. 相似文献
74.
Gregor S Zimmermann Claus Neurohr Heidrun Villena-Hermoza Rudolf Hatz Juergen Behr 《Respiratory research》2009,10(1):89
Background
Human Bronchial epithelial cells (hu-BEC) have been claimed to play a significant role in the pathogenesis of chronic inflammatory airway diseases like COPD. In this context IL-8 and GM-CSF have been shown to be key cytokines. Some antibiotics which are routinely used to treat lower respiratory tract infections have been shown to exert additional immunomodulatory or anti-inflammatory effects. We investigated whether these effects can also be detected in hu-BEC.Methods
Hu-BEC obtained from patients undergoing lung resections were transferred to air-liquid-interface (ALI) culture. These cultures were incubated with cefuroxime (CXM, 10-62.5 mg/l), azithromycin (AZM, 0.1-1.5 mg/l), levofloxacin (LVX, 1-8 mg/l) and moxifloxacin (MXF, 1-16 mg/l). The spontaneous and TNF-α (10 ng/ml) induced expression and release of IL-8 and GM-CSF were measured using PCR and ELISA in the absence or presence of these antibiotics.Results
The spontaneous IL-8 and GM-CSF release was significantly reduced with MXF (8 mg/l) by 37 ± 20% and 45 ± 31%, respectively (both p < 0.01). IL-8 release in TNF-α stimulated hu-BEC decreased by 16 ± 8% (p < 0.05) with AZM (1.5 mg/l). With MXF a concentration dependent decrease of IL-8 release was noted up to 39 ± 7% (p < 0.05). GM-CSF release from TNF-α stimulated hu-BEC was maximally decreased by 35 ± 24% (p < 0.01) with MXF (4 mg/l).Conclusion
Using ALI cultures of hu-BEC we observed differential effects of antibiotics on spontaneous and TNF-α induced cytokine release. Our data suggest that MXF and AZM, beyond bactericidal effects, may attenuate the inflammatory process mediated by hu-BEC. 相似文献75.
Jürgen L?hler Heidrun Hirner Bernhard Schmidt Klaus Kramer Dietmar Fischer Dietmar R. Thal Frank Leith?user Uwe Knippschild 《PloS one》2009,4(1)
Background
Casein kinase 1 delta (CK1δ) phosphorylates many key proteins playing important roles in such biological processes as cell growth, differentiation, apoptosis, circadian rhythm and vesicle transport. Furthermore, deregulation of CK1δ has been linked to neurodegenerative diseases and cancer. In this study, the cell specific distribution of CK1δ in various tissues and organs of young adult BALB/c mice was analysed by immunohistochemistry.Methodology/Principal Findings
Immunohistochemical staining of CK1δ was performed using three different antibodies against CK1δ. A high expression of CK1δ was found in a variety of tissues and organ systems and in several cell types of endodermal, mesodermal and ectodermal origin.Conclusions
These results give an overview of the cell-type specific expression of CK1δ in different organs under normal conditions. Thus, they provide evidence for possible cell-type specific functions of CK1δ, where CK1δ can interact with and modulate the activity of key regulator proteins by site directed phosphorylation. Furthermore, they provide the basis for future analyses of CK1δ in these tissues. 相似文献76.
An automated quantitative image analysis tool for the identification of microtubule patterns in plants
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Christine Faulkner Ji Zhou Alexandre Evrard Gildas Bourdais Dan MacLean Heidrun Häweker Peter Eckes Silke Robatzek 《Traffic (Copenhagen, Denmark)》2017,18(10):683-693
High throughput confocal imaging poses challenges in the computational image analysis of complex subcellular structures such as the microtubule cytoskeleton. Here, we developed CellArchitect, an automated image analysis tool that quantifies changes to subcellular patterns illustrated by microtubule markers in plants. We screened microtubule‐targeted herbicides and demonstrate that high throughput confocal imaging with integrated image analysis by CellArchitect can distinguish effects induced by the known herbicides indaziflam and trifluralin. The same platform was used to examine 6 other compounds with herbicidal activity, and at least 3 different effects induced by these compounds were profiled. We further show that CellArchitect can detect subcellular patterns tagged by actin and endoplasmic reticulum markers. Thus, the platform developed here can be used to automate image analysis of complex subcellular patterns for purposes such as herbicide discovery and mode of action characterisation. The capacity to use this tool to quantitatively characterize cellular responses lends itself to application across many areas of biology. 相似文献
77.
Kazuhiro Sato Fumitaka Abe Martin Mascher Georg Haberer Heidrun Gundlach Manuel Spannagl Kenta Shirasawa Sachiko Isobe 《DNA research》2021,28(3)
We have established a high-quality, chromosome-level genome assembly for the hexaploid common wheat cultivar ‘Fielder’, an American, soft, white, pastry-type wheat released in 1974 and known for its amenability to Agrobacterium tumefaciens-mediated transformation and genome editing. Accurate, long-read sequences were obtained using PacBio circular consensus sequencing with the HiFi approach. Sequence reads from 16 SMRT cells assembled using the hifiasm assembler produced assemblies with N50 greater than 20 Mb. We used the Omni-C chromosome conformation capture technique to order contigs into chromosome-level assemblies, resulting in 21 pseudomolecules with a cumulative size of 14.7 and 0.3 Gb of unanchored contigs. Mapping of published short reads from a transgenic wheat plant with an edited seed-dormancy gene, TaQsd1, identified four positions of transgene insertion into wheat chromosomes. Detection of guide RNA sequences in pseudomolecules provided candidates for off-target mutation induction. These results demonstrate the efficiency of chromosome-scale assembly using PacBio HiFi reads and their application in wheat genome-editing studies. 相似文献
78.
Borck G Wunram H Steiert A Volk AE Körber F Roters S Herkenrath P Wollnik B Morris-Rosendahl DJ Kubisch C 《Human genetics》2011,129(1):45-50
Warburg Micro syndrome and Martsolf syndrome are clinically overlapping autosomal recessive conditions characterized by congenital
cataracts, microphthalmia, postnatal microcephaly, and developmental delay. The neurodevelopmental and ophthalmological phenotype
is more severe in Warburg Micro syndrome in which cerebral malformations and severe motor and mental retardation are common.
While biallelic loss-of-function mutations in RAB3GAP1 are present in the majority of patients with Warburg Micro syndrome; a hypomorphic homozygous splicing mutation of RAB3GAP2 has been reported in a single family with Martsolf syndrome. Here, we report a novel homozygous RAB3GAP2 small in-frame deletion, c.499_507delTTCTACACT (p.Phe167_Thr169del) that causes Warburg Micro syndrome in a girl from a consanguineous
Turkish family presenting with congenital cataracts, microphthalmia, absent visually evoked potentials, microcephaly, polymicrogyria,
hypoplasia of the corpus callosum, and severe developmental delay. No RAB3GAP2 mutations were detected in ten additional unrelated patients with RAB3GAP1-negative Warburg Micro syndrome, consistent with further genetic heterogeneity. In conclusion, we provide evidence that RAB3GAP2 mutations are not specific to Martsolf syndrome. Rather, our findings suggest that loss-of-function mutations of RAB3GAP1 as well as functionally severe RAB3GAP2 mutations cause Warburg Micro syndrome while hypomorphic RAB3GAP2 mutations can result in the milder Martsolf phenotype. Thus, a phenotypic severity gradient may exist in the RAB3GAP-associated disease continuum (the “Warburg–Martsolf syndrome”) which is presumably determined by the mutant gene and the
nature of the mutation. 相似文献
79.
Heidrun Feuchtmayr Dermot McKee Ian F. Harvey David Atkinson Brian Moss 《Hydrobiologia》2007,584(1):425-432
There is increasing concern about the effect of climate change on aquatic systems. We examined changes in macroinvertebrate
communities caused by increased temperature (3°C above ambient during summer only and continuous 3°C above ambient all year
round), influences of fish (Gasterosteus aculeatus L.) and addition of nutrients (nitrogen and phosphorus) in 48 large-scale (3000 l) tanks over a 2 year period. While numbers
of Isopoda, Chaoborus, Corixidae, Ephemeroptera, Notonectidae and Odonata were reduced by the presence of fish, nutrient addition caused isopods,
corixids, mayflies and odonates to increase in abundance. Impacts of temperature increase were surprisingly low, with only
gastropods increasing in heated tanks, suggesting that, overall abundances of most macroinvertebrate taxa will not be severely
affected by the predicted temperature rise. To determine if taxa were sampled representatively during the experiment, net
sweep samples taken towards the end of the experiment were compared with final macroinvertebrate abundances when the complete
contents of each tank were harvested. We found that net sweeping is an appropriate semi-quantitative method for most taxa
in mesocosm tanks. However, mites, coleopteran adults and larvae, dipterans and Chaoborus were not adequately sampled. This might explain why we could not detect any treatment effects of temperature, fish or nutrients
on mites, coleopterans and dipterans and calls for different sampling techniques for these taxa, especially in ponds with
vegetation stands. 相似文献
80.
Karl-Heinz Schmidt Heidrun Berressem Karl Georg Berressem und Marianne Demuth 《Journal of Ornithology》1985,126(1):63-71
Zusammenfassung In der Umgebung von Schlüchtern (50°21 N, 09°31 E) und im Stadtbereich Frankfurts (50°08 N, 08°38 E) wurden in mehreren Untersuchungsgebieten seit 1971 bzw. seit 1977 von Oktober/November bis Februar/März regelmäßige nächtliche Kontrollen von 1121 Nistkästen durchgeführt, und zwar in einzelnen Jahren in 3tägigen, wöchentlichen, 14tägigen und monatlichen Abständen. Für eine weitgehend vollständige Erfassung der relativ stabilen Population genügten monatliche Kontrollen. Bei nur einer Winterkontrolle wurde der Bestand erheblich unterschätzt: bei alten betrug der Schätzfehler mindestens 25 %, bei jungen mindestens 45 %. Kohlmeisen reagierten auf nächtliche Kontrollen mit einem Wechsel des Übernachtungsortes. Erst bei Kontrollabständen von 3 Tagen mied ein Teil der Population die Nistkästen. Regelmäßige Nachtkontrollen können zum Verständnis bestandsregulierender Prozesse wie Zu- und Abwanderung, Ansiedlung, Ortstreue und Wintermortalität beitragen.
Studies on Great Tits (Parus major) during winter — possibilities and limits of nocturnal checks
Summary 1121 nest boxes were regularly checked during night from October/November until February/March in the area of Schlüchtern (50°21 N, 09°31 E) since 1971 and since 1977 in the area of Frankfurt (50°08 N, 08°38 E). During that time the checking was done in three-day, weekly, bi-weekly and monthly intervals. A single monthly checking was sufficient for an extensive and complete estimation of the relative stable population. By only one winter checking the population was considerably underestimated: the estimation error was at least 25 % in old and at least 45 % in young . Great Tits reacted to night checking by changing their nocturnal roosting place. A portion of the population will keep clear of the nest boxes when checking is done in three-day intervals. It is being discussed as to what extent regular night checking contributes to the understanding of population regulating processes such as migration, settlement, site fidelity of native birds and winter mortality.相似文献