The present-day lithospheric architecture of modern and ancient orogens can be imaged by geophysical techniques. For ancient orogens, unravelling their architecture at the time of formation is hindered by later tectono-magmatic events. In this paper, we use spatial variations in radiogenic isotopic compositions of Late Triassic magmatism from the Yidun Terrane, eastern Tibetan Plateau, to establish its lithospheric architecture during the Triassic. Comprehensive geochemical and isotopic data of Late Triassic magmatic rocks from four transects across the Yidun Terrane document eastward enrichment in whole-rock Nd, Sr, and zircon Hf isotopic compositions. Mafic and felsic rocks of major plutons show coherent and nonlinear trends in the Zr and P2O5 systematics and have limited variation of isotopic compositions. This indicates that Late Triassic magmatic differentiation was dominated by fractionation of mantle-derived mafic magmas. The spatial isotopic trends result from changing mantle sources, including variable contributions of isotopically depleted asthenospheric mantle and isotopically enriched subcontinental lithospheric mantle (SCLM) to magma sources. The spatial variation of mantle sources suggests a westward thinning of the SCLM during the Triassic. We propose that this architecture is most likely associated with eastward subduction of oceanic lithosphere of the Jinshajiang Ocean located at the west of the Yidun Terrane, immediately prior to the Late Triassic magmatism.
We looked into the ways in which the digital economy helps to speed up the convergence of environmentally responsible economic efficiency across China’s regions by facilitating the flow and optimization of R&D resources. We measured the mobility of R&D capital and personnel across 30 provinces in China from 2001 to 2022 using a gravity model, assessed the efficiency of green economic using the SBM method, and determined the influence of the digital economy by the use of a fixed-effects model. (1) We identified the σ convergence (the absolute gap between per capita income or per capita economic efficiency levels of different economies gradually decreasing over time) and β convergence (the negative correlation between the rate of economic efficiency increase among various economies or regions and their initial level of economic efficiency) characteristics of green economic efficiency, discovering that the digital economy has sped up the process of convergence of environmentally responsible economic efficiency in regional areas. (2) We found a latecomer advantage in the convergence of China’s green economic efficiency, along with the advancement of the digital economy; that is, the green economic efficiency more quickly converged in less developed regions and regions with fewer resources. (3) The digital economy is able to accelerate the convergence of regional green economy efficiency through the use of internal mechanisms such as the efficient flow of research and development factors and the reasonable allocation of those factors. By identifying the impact of the digital economy on the gaps in regional green economic efficiency from the new perspective of the flow and allocation of R&D elements, this study contributes to the existing body of literature. It also provides new information regarding the ways in which the digital economy is driving the development of China’s green economy. We offer policy suggestions based on our findings to assist regions in achieving a balance between the digital economy and industrial development through the utilization of resources that are specific to the location.
BACKGROUND Endoscopic full-thickness resection (EFTR) is increasingly used for treating gastrointestinal stromal tumors (GISTs) in the stomach. AIM To compare the efficacy, tolerability, and clinical outcomes of EFTR vs surgical resection (SR) for gastric GISTs. METHODS We collected clinical data from patients diagnosed with GISTs who underwent either EFTR or SR at our hospital from October 2011 to July 2024. Patients were matched in a 1:1 ratio based on baseline characteristics and tumor clinical-pathological features using propensity score matching. We analyzed perioperative outcomes and follow-up data. The primary outcome measure was progression-free survival (PFS). RESULTS Out of 912 patients, 573 met the inclusion criteria. After matching, each group included 95 patients. The EFTR group demonstrated statistically significant advantages over the SR group in average operative time (P < 0.001), length of hospital stay (P < 0.001), time to resume liquid diet (P < 0.001), incidence of adverse events (P = 0.031), and hospitalization costs (P < 0.001). The en bloc resection rate was significantly different, with SR group at 100% and EFTR group at 93.7% (P = 0.038). The median follow-up was 2451.50 days. Recurrence occurred in 3 patients in the EFTR group and 4 patients in the SR group, with no statistically significant difference (P = 1.000). Factors associated with PFS included age, tumor size, high-risk category in the modified National Institutes of Health (NIH) risk score, and resection status. Resection status was identified as an independent prognostic factor for PFS (P = 0.0173, hazard ratios = 0.0179, 95%CI: 0.000655-0.491). Notably, there was no statistically significant difference in PFS between the two groups. CONCLUSION This study is a non-inferiority design. The EFTR group significantly outperformed the SR group in terms of operative time, length of hospital stay, time to resume a liquid diet, incidence of adverse events, and hospitalization costs, demonstrating its higher economic efficiency and better tolerability. Additionally, although the en bloc resection rate was lower in the EFTR group compared to the SR group, there were no significant differences in tumor recurrence rates and progression-free survival between the two groups. This study found no statistical difference in the primary endpoint of postoperative recurrence rates between the two groups. However, due to sample size limitations, this result requires further validation in larger-scale studies. The current results should be viewed as exploratory evidence.
Abstract Clival screw and plate fixation technique is an alternative or supplement to the occipitocervical instrumentation. However, no report has clarified the applied anatomy of clivus in patients with atlas assimilation (C1A), especially for clival screw fixation. Therefore, we measured the parameters of clival lengths, widths, putative screw lengths, clival-cervical angel and foramen magnum diameters on CT images in a cohort of 81 C1A patients and patients without C1A. The clivus showed a rectangular shape in 96.3% (78/81) of C1A patients and a normal-like triangle shape in 3.7% (3/81) of C1A patients. The intracranial clival length decreased 13% (37 mm) in C1A patients, the extracranial clival length 14.8% (24.1 mm), the clival-cervical angle 6.2% (122.3°) and the superior screw length 11.3% (14.1 mm), the sagittal diameter of foramen magnum 16% (28.0 mm), respectively. There was no significant difference in the widest or narrowest clival width, or the middle screw length, or the transverse diameter of foramen magnum between groups. The inferior clivus was feasible for an average 9.7-mm-length screw placement in C1A patients, while not in patients without C1A. The present study characterizes clivus of C1A patients with an unnormal-like rectangular shape and confirmes a screw placement at the inferior clivus.
碎屑锆石年代学不但能够限定地层沉积开始的最大时限,还能为示踪沉积物源区提供关键信息。中国西南部的松潘-甘孜褶皱带广泛出露一套巨厚的三叠纪复理石沉积,其物源区和可能存在的同期抬升与剥蚀历史并未得到很好约束。本文获得的松潘-甘孜褶皱带南部雅江地区上三叠统四套地层(由老至新分别为侏倭组、新都桥组、两河口组和雅江组)5件砂岩样品的碎屑锆石U-Pb年龄和锆石Hf同位素数据表明,最年轻锆石年龄指示侏倭组从~229Ma后开始沉积,新都桥组则从~223Ma后开始沉积。碎屑锆石年龄频谱图显示四套地层都具有中奥陶世-早泥盆世(465~398Ma)和中二叠世-晚三叠世(271~225Ma)的年龄峰。除两河口组外的其他三套地层还具有较强的古元古代(1.90~1.86Ga)和新元古代(872~712Ma)的年龄峰。锆石Hf同位素显示松潘-甘孜褶皱带南部上三叠统小于300Ma的锆石颗粒主要来自峨眉山大火成岩省和义敦岩浆弧。本文物源区示踪结果表明,华南板块和义敦地体可能为松潘-甘孜褶皱带南部地层的主要物源区。晚三叠世由于周缘地体的强烈汇聚,松潘-甘孜褶皱带在小于~18Myr的时间内经历了快速的隆升和剥蚀作用,剥蚀产生的碎屑物质被搬运至四川盆地的西缘再沉积。;Detrital zircon geochronology can not only help to determine the maximum depositional ages of sedimentary strata but also provide key constraints on the sediment provenance. The provenance of the Late Triassic flysch in the Songpan-Ganzi fold belt, SW China and the uplift history possibly occurred at slightly later remain debated. This paper reports new detrital zircon U-Pb ages and Hf isotopic data of five sandstone samples from the Upper Triassic Zhuwo, Xinduqiao, Lianghekou, and Yajiang formations (upward in section) in Yajiang, southern Songpan-Ganzi fold belt. The youngest detrital zircon ages indicate that the deposition of Zhuwo and Xinduqiao formations initiated around 229Ma and 223Ma, respectively. The probability density plots show that these four formations collectively yield age peaks of Middle Ordovician to Early Devonian (ca. 465~398Ma) and Middle Permian to Late Triassic (ca. 271~225Ma). Except for one sample from the Lianghekou Formation, the other samples have age peaks of Paleoproterozoic (ca. 1.90~1.86Ga) and Neoproterozoic (ca. 872~712Ma). The Hf isotopic data indicates that younger than 300Ma grains are mainly sourced from the Emeishan large igneous province to the east and the Yidun magmatic arc to the west. Our provenance study reveals that the Late Triassic sediments in the southern part of the Songpan-Ganzi fold belt is probably derived from the South China Block and the Yidun Terrane. This paper proposes that, during the Late Triassic, the Songpan-Ganzi fold belt may have experienced rapid uplift and exhumation within ~18Myr due to the strong convergence of surrounding terranes, following by the sediment delivery to the western margin of the Sichuan Basin.
Volcanic groups of are natural ecosystem and natural environmental system which are mainly formed upon Tertiary volcano geology environment,and it has special features in aspects of the volcano geology structure,formation mechanism,typical rock outcrop and landscape geomorphology.It has been named as Yitong Type volcano by volcano scholars because of its special formation mechanism and the distribution,so that it is ranked as national geo-park.Geology traces of volcanoes are typical and scientific of the volcanic geology research,and it is enjoyable for the leisure of visitors.
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