A new alvarezsaurid theropod, Xixianykus zhangi gen. et sp. nov., is described based on a partial postcranial skeleton collected from the Upper Cretaceous Majiacun Formation of Xixia County, Henan Province. The new taxon can be diagnosed by the following autapomorphies: sacral rib-transverse process complexes and zygapophyses fused to form separate anterior and posterior laminae; distinct fossa dorsal to antitrochanter on lateral surface of ilium; short ridge along posterior surface of pubic shaft near proximal end; distinct depression on lateral surface of ischium near proximal end; sharp groove along posterior surface of ischium; distal end of femur with transversely narrow ectocondylar tuber that extends considerable distance proximally as sharp ridge; transversely narrow tibial cnemial crest with sharp, ridgelike distal half; lateral margin of tibiotarsus forms step near distal end; fibula with substantial extension of proximal articular surface onto posterior face of posteriorly curving shaft; distal tarsals and metatarsals co-ossified to form tarsometatarsus; and sharp flange along anteromedial margin of metatarsal IV near proximal end. Cladistic analysis places this taxon as a basal parvicursorine within the Alvarezsauridae, a position consistent with the presence of several incipiently developed parvicursorine features in this taxon and also with its relatively early geological age. A brief analysis of vertebral functional morphology, together with data from the hindlimb, suggests that parvicursorines represent extreme cursors among non-avian dinosaurs.
BackgroundSouthwestern Henan Province in central China contains many down-faulted basins, including the Xixia Basin where the Upper Cretaceous continental sediments are well exposed. The Majiacun Formation is a major dinosaur-bearing stratigraphic unit that occurs in this basin.Methodology/Principal FindingsA new basal hadrosauroid dinosaur, Zhanghenglong yangchengensis gen. et sp. nov., is named based on newly collected specimens from the middle Santonian Majiacun Formation of Zhoujiagou Village, Xixia Basin. Two transitional features between basal hadrosauroids and hadrosaurids are attached to the diagnosis of the new taxon, namely five maxillary foramina consisting of four small scattered ones anteroposteriorly arranged in a row and a large one adjacent to the articular facet for the jugal, and dentary tooth crowns bearing both median and distally offset primary ridges. Zhanghenglong also displays a unique combination of plesiomorphic and derived features of hadrosauroids, and is clearly morphologically transitional between basal hadrosauroids and hadrosaurids. Furthermore, some measurement attributes in osteology are applied to the quantitative analysis of Zhanghenglong. For these attributes, the partition of the dataset on most hadrosauroid species resulting from model-based cluster analysis almost matches taxonomic separation between basal hadrosauroids and hadrosaurids. Data of Zhanghenglong on selected measurement attributes straddle the two combinations of intervals of partitioned datasets respectively related to basal hadrosauroids and hadrosaurids. This condition is similar to mosaic evolution of morphological characters present in the specimens of the taxon. The phylogenetic analysis of Hadrosauroidea recovers a clade composed of Zhanghenglong, Nanyangosaurus, and Hadrosauridae with an unresolved polytomy.Conclusions/Significance
Zhanghenglong is probably a relatively derived non-hadrosaurid hadrosauroid, based on the inferences made from the morphological comparisons, quantitative evaluation of measurements, and cladistic analysis. In combination with information on the stratigraphy, phylogeny and biogeography, the material of Zhanghenglong provides direct evidence for the hypothesis that hadrosaurids might have originated in Asia.
Novel targeted therapies need to be developed for gastric cancer, the third most common cancer type and the second most common cause of cancer-related mortality in China. Previous studies indicate that angiopoietin (Ang)-2 serves a role in the proliferation, migration, invasion and adhesion of malignant cells. The present study identified, using functional studies, that exogenous expression of miR-218 increased migration of NCI-87 and HGC-27 gastric cancer cells, which coincided with a reduction in the expression of Ang-2. In addition, intratumoral delivery of miR-218 inhibited proliferation and angiogenesis of gastric cancer cells in vivo, with a corresponding decreased in Ang-2 expression. These results indicate that miR-218 serves an important role in gastric cancer tumorigenesis through regulating the expression of Ang-2. Therefore, components of miR-218/Ang-2 signaling could provide novel therapeutic targets for the treatment of gastric cancer.
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