Geochronology,Geochemistry,and Sr-Nd-Hf Isotopes of the Diorite Porphyrites from the Weining Beishan Area,Ningxia Hui Autonomous Region:Constraints on Their Source and Tectonic Implications

The Weining Beishan area of Ningxia Hui Autonomous Region is located at on the western edge of the Helanshan tectonic belt,which is a tectonic joint among Alxa Block,Ordos Block,and North Qilian orogenic belt.However,the tectonic evolution of this area remains unclear due to the lack of magmatic information.This paper conducted researches on geochronology,geochemistry,and Sr-Nd-Hf isotopes of the diorite porphyrites exposed in the Weining Beishan area.The zircon U-Pb dating yields two ages of 145.0±1.1 and 146.2±1.5 Ma,and the whole-rock geochemical data indicate that the diorite porphyrites are metaluminous to weakly peraluminous and high-K calc-alkaline series.The characteristics of highly initial^(87)Sr/^(86)Sr ratios(0.70816 to 0.71047),negativeε_(Nd)(t)(−8.9 to−8.4),and negativeε_(Hf)(t)(−13.8 to−21.2)indicate that the diorite porphyrites originated from partial melting of the middle-lower ancient crust related to the North China Craton.Combined with the regional geology,we suggested that partial melting was triggered by a tectonic activity of deep faults cutting through the crust under the regional stress transformation from compressing to extension during the Late Jurassic–Early Cretaceous,which is probably related to the westward subduction of the Paleo-Pacific Plate.

Protective effect and mechanisms of Weining granule on N-methyl-N’-nitro-N-nitrosoguanidine-induced gastric cancer in rats

OBJECTIVE:To investigate the protective effect and molecular mechanisms of Weining granule on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced gastric cancer in rats.METHODS:A total of sixty healthy male wistar rats were randomly divided into five groups,including control group (CG),gastric cancer model group (MG),low-dose Weining granule treated group (LWT),medium-dose Weining granule treated group (MWT),and high-dose Weining granule treated group (HWT).Except the control group,the other groups were treated with MNNG to establish a rat model of gastric cancer.Low-dose Weining granule treated group,medium-dose Weining granule treated group,and high-dose Weining granule treated group were fed 9.0,18.0 and 36.0 g/kg Weining granule,respectively.Histopathologic and molecular biologic technology were adopted to determine the protective effect of Weining granule on MNNG-induced gastric cancer in rats.The pathological changes of gastrointestinal tissue were observed.Meanwhile,the differential expression of proliferation,apoptosis and angiogenesis markers were determined,including proliferating cell nuclear antigen (PCNA),pokemon,cyclin D1,B-cell lymphoma-2 (Bcl-2),caspase-3,phosphatase and tensin homolog (PTEN) and vascular endothelial growth factor (VEGF).RESULTS.:After the MNNG treated,the pathological changes of stomach tissue were improved noticeably,including the intestinal metaplasia and atypic hyperplasia.The experiment was completed in.58 rats (96.67%).As compared with gastric cancer model group,the general states of rats were improved significantly after treated with different dose Weining granule.Moreover,treatment with different doses of Weining granule could inhibit the protein and mRNA expression of PCNA,pokemon,cyclin D1,Bcl-2,and VEGF,while increase caspase-3 and PTEN (P < 0.01).CONCLUSION:Weining granule could improve gastric cancer by suppressing cell proliferation,promoting tumor cell apoptosis,and inhibiting angiogenesis.