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Dinosaur egg fossils are important for exploring the survival and extinction of the dinosaurs. Current researches on dinosaur egg fossils are concentrated in their biology and burial features. In this study, Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) was used to determine trace element composition of twelve dinosaur eggshell fossils in the late Cretaceous from Xixia basin and their surrounding rocks, in order to the relationship between trace elements and the extinction of dinosaurs. Results show that the dinosaur eggshell fossils are depleted in organic elements such as C, N, P and S, and mainly consist of essential elements such as Ca, Al, Mg, Fe and K and other trace elements such as Sr, Mn, Ba, La, Zn, B, V, Co and Ir. Abnormal high Ir and Sr may be related to the extraterrestrial impact event causing the dramatic changes of the ecological environment. Element assemblages indicated that the climate during the late Cretaceous in this area might have been semiarid to arid. Abnormal high Ir and Sr in the environment probably have caused structure and pathological changes of those eggs within the dinosaurs. Thereby the dinosaur eggs could not be hatched, which probably resulted in the gradual demise of dinosaurs. This study provides an important basis for investigating the living environment of dinosaurs, causes of extinction and the late Cretaceous climate.

The Tianshan Carboniferous rift-related volcanic rocks make up a large igneous province in northwestern China. On the basis of petrogeochemical data, the rift-related basic lavas can be classified into two major magma types. These are (1) a low-Ti/Y type situated in central and eastern Tianshan that exhibits low Ti/Y (500), Ce/Y (>3), and Si[O.sub.2] (49-55 wt%) and relatively low [Fe.sub.2][O.sub.3.sup.T] (5.8-7.8 wt%). Elemental data suggest that the chemical variations of the low-Ti/Y and high-Ti/Y lavas cannot be explained by crystallization from a common parental magma. The Tianshan Carboniferous basic lavas most likely originated from an asthenospheric oceanic-island-basalt-like mantle source ([sup.87]Sr/[sup.86][Sr.sub.(t)] [approximately equal to] 0.703-0.705, [[member of].sub.Nd(t)] [approximately equal to] +4 to +7). Crustal contamination and continental lithospheric mantle have also contributed significantly to the formation of the basic lavas of the Tianshan Carboniferous rift. Our data show that spatial petrogeochemical variations exist in the volcanic rocks of the Tianshan large igneous province. The location of the thickest volcanic succession, which has dominantly tholeiitic lavas, in the eastern Tianshan may have been centered over the melting anomaly in the mantle. The eastern Tianshan basic magmas were generated by a higher degree of partial melting in the spinel-garnet transition zone of the mantle compared to the alkaline basaltic lavas that are the dominant magma type in the western Tianshan. The lower degree of partial melting in the garnet stability field of the mantle, as is characteristic of the western Tianshan basic lavas, may be the result of a relatively thicker lithosphere and lower geotherm. Keywords: Tianshan Carboniferous rift-related volcanic rocks, geochemistry, petrogenesis, asthenosphere, lithosphere, northwest China.

Abstract: Oral lichen planus (OLP) is a T cell-mediated autoimmune disease of oral mucosa, in which T helper 1 (Th1) cells are greatly involved. Chemokine CCL5 is required for T cells infiltration and activation. CCR5, one of its receptors, specifically expressed on Th1 cells among CD4+ T cells, can be up-regulated by Th1 cytokines like interleukin2 (IL-2) and interferon-gamma (IFN-γ), and down-regulated by Th2 cytokines like IL-4. The present study aimed to determine whether CCL5 and CCR5 had effects on the immune response of OLP. We analyzed the proportion of CCR5+CD4+ T cells in CD4+ T cells using flow cytometry and the serum levels of CCL5, IL-2, IFN-γ, and IL-4 with ELISA. MicroRNA-125a (miR-125a), a blocker of CCL5, was examined with RT-PCR. The results showed both the serum CCL5 and the percentage of CCR5+CD4+ T cells elevated in OLP patients. Serum IL-2 and IFN-γ increased in OLP patients, but IL-4 decreased. MiR-125a was down-regulated in OLP patients, and there was a negative correlation between miR-125a content and the OLP severity which was measured with a RAE (reticular, atrophic and erosive lesion) scoring system. In conclusion, increasing CCl5/CCR5 might participate in the immune response of OLP. Th1-type cytokines environment presented in OLP probably performed as a magnifier for the CCR5. Moreover, miR-125a might be a candidate biomarker to estimate the severity of OLP. [Copyright &y& Elsevier]