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31.
ERVĪNS LUKŠEVIČS PER E. AHLBERG ĢIRTS STINKULIS JEĻENA VASIĻKOVA IVARS ZUPIŅŠ 《Lethaia: An International Journal of Palaeontology and Stratigraphy》2012,45(3):356-370
Luk?evi?s, E., Ahlberg, P.E., Stinkulis, ?., Vasi?kova, J. & Zupi??, I. 2011: Frasnian vertebrate taphonomy and sedimentology of macrofossil concentrations from the Langsēde Cliff, Latvia. Lethaia, Vol. 45, pp. 356–370. The siliciclastic sequence of the Upper Devonian of Kurzeme, Western Latvia, is renowned for abundant vertebrate fossils, including the stem tetrapods Obruchevichthys gracilis and Ventastega curonica. During the first detailed taphonomic study of the vertebrate assemblage from the Ogre Formation cropping out at the Langsēde Cliff, Imula River, abundant vertebrate remains have been examined and identified as belonging to one psammosteid, two acanthodian and three sarcopterygian genera; the placoderm Bothriolepis maxima dominates the assemblage. Besides fully disarticulated placoderm and psammosteid plates, separate sarcopterygian scales and teeth, and acanthodian spines, partly articulated specimens including complete distal segments of Bothriolepis pectoral fins, Bothriolepis head shields and sarcopterygian lower jaws have been found. The size distribution of the placoderm bones demonstrates that the individuals within the assemblage are of approximately uniform age. Distinct zones have been traced within the horizontal distribution of the bones. These linear zones are almost perpendicular to the dominant dip azimuth of the cross‐beds and ripple‐laminae and most probably correspond to the depressions between subaqueous dunes. Concavity ratio varies significantly within the excavation area. The degree of fragmentation of the bones and disarticulation of the skeletons suggest that the carcasses were reworked and slightly transported before burial. Sedimentological data suggest deposition in a shallow marine environment under the influence of rapid currents. The fossiliferous bed consists of a basal bone conglomerate covered by a cross‐stratified sandstone with mud drapes, which is in turn overlain by ripple laminated sandstone, indicating the bones were buried by the gradual infilling of a tidal channel. All the Middle–Upper Devonian vertebrate bone‐beds from Latvia are associated with sandy to clayey deposits and have been formed in a sea‐coastal zone during rapid sedimentation episodes, but differ in fossil abundance and degree of preservation. □Agnathans, Devonian, facies analysis, fish, fossil assemblage, palaeoenvironment. 相似文献
32.
Thomas G Kristensen Jesper Nielsen Christian NS Pedersen 《Algorithms for molecular biology : AMB》2010,5(1):9
Background
The fingerprint of a molecule is a bitstring based on its structure, constructed such that structurally similar molecules will have similar fingerprints. Molecular fingerprints can be used in an initial phase of drug development for identifying novel drug candidates by screening large databases for molecules with fingerprints similar to a query fingerprint. 相似文献33.
Thomas Mailund Gerth S Brodal Rolf Fagerberg Christian NS Pedersen Derek Phillips 《BMC bioinformatics》2006,7(1):29-8
Background
The neighbor-joining method by Saitou and Nei is a widely used method for constructing phylogenetic trees. The formulation of the method gives rise to a canonical Θ(n 3) algorithm upon which all existing implementations are based. 相似文献34.
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36.
Eman Yosrey Heba Elmansi Zeinab A. Sheribah Mohamed El-Sayed Metwally 《Luminescence》2022,37(4):569-576
A sensitive and green micellar spectrofluorimetric approach was applied for the simultaneous estimation of ivabradine hydrochloride (IVB) and felodipine (FLD) in the ng/ml concentration range. The approach depended on measuring the first derivative synchronous peak amplitude (1D) of both drugs at ∆λ = 60 nm in a Tween-80 micellar system. The method was rectilinear alongside the concentration ranges 0.02–0.4 μg/ml and 0.05–1.0 μg/ml at 269.5 nm and 378.5 nm for IVB and FLD, respectively. The proposed method was validated by following the International Council for Harmonization guidelines. The method was successfully applied without interference for laboratory-prepared synthetic mixtures, single pharmaceutical preparations, and within spiked biological fluids with acceptable percentage recoveries. A comparison of the performance of the suggested method with other methods, showed no discrepancy. The method’s ecofriendly property evaluated using three different tools, confirming an excellent green method. 相似文献
37.
Reem A. Alajmi Dina M. Metwally Manal F. El-Khadragy Hany M. Yehia Saeed El-Ashram Zainab Almusawi Muhammad Amjad Bashir Noura J. Alotaibi Rewaida Abdel-Gaber 《Saudi Journal of Biological Sciences》2021,28(4):2613-2617
The taxonomy of the order Phthiraptera is unstable and still problematic to researchers. Most of the current taxon classifications are mainly based on morphological features. Campanulotes bidentatus belongs to the chewing lice of the Philopteridae family that mostly parasitic on birds. There is a lack of sequence data and phylogenetic analyses on the family Philopteridae. In the current study, C. bidentatus was collected from the domestic pigeon Columba livia and identified morphologically and molecularly based on the mitochondrial cytochrome c oxidase subunit 1 gene (COI). The infection rate of the Campanulotes genus was approximately 58.82% in this study. Phylogenetic analysis based on the mt COI gene was informative for members of Philopteridae and the group taxon genera formed distinct clades. Future studies were recommended using the 16s rRNA to enhance the tree topology and obtain clear differentiation between genera. 相似文献
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39.
Galal Yahya Nashwa Hashem Mohamed Jordi Pijuan Noura M. Seleem Rasha Mosbah Steffen Hess Ahmed A. Abdelmoaty Rafa Almeer Mohamed M. Abdel-Daim Hamoud Shulaywih Alshaman Ibrahim Juraiby Kamel Metwally Zuzana Storchova 《Microbial biotechnology》2021,14(5):2199-2213
Sofosbuvir and Daclatasvir are among the direct-acting antiviral (DAA) medications prescribed for the treatment of chronic hepatitis C (CHC) virus infection as combination therapy with other antiviral medications. DAA-based therapy achieves high cure rates, reaching up to 97% depending on the genotype of the causative hepatitis C virus (HCV). While DAAs have been approved as an efficient and well-tolerated therapy for CHC, emerging concerns about adverse cardiac side effects, higher risk of recurrence and occurrence of hepatocellular carcinoma (HCC) and doubts of genotoxicity have been reported. In our study, we investigated in detail physiological off-targets of DAAs and dissected the effects of these drugs on cellular organelles using budding yeast, a unicellular eukaryotic organism. DAAs were found to disturb the architecture of the endoplasmic reticulum (ER) and the mitochondria, while showing no apparent genotoxicity or DNA damaging effect. Our study provides evidence that DAAs are not associated with genotoxicity and highlights the necessity for adjunctive antioxidant therapy to mitigate the adverse effects of DAAs on ER and mitochondria. 相似文献
40.
Abdallah A. Omar Elsayed M. Elrashidy Nabila A. Ghazy Ali M. Metwally Jürgen Ziesche Ferdinand Bohlmann 《Phytochemistry》1984,23(4):915-916
The aerial parts of Xanthium spinosum afforded in addition to known xanthanolides three new ones. The structures were elucidated by spectroscopic methods and by partial synthesis. Furthermore one lactone was transformed to a known derivative. 相似文献