Based on the collection, sorting, and in-depth analysis of the relevant data from the major active tectonic belts in central and southern Xizang, the basic structural characteristics of the region are systematically summarized, and the structural units are classified in detail. At the same time, the constructional and deformation characteristics of each tectonic unit are deeply discussed, and the tectonic levels and deformation phases of this area are further defined, and the tectonic deformation sequence is established. Finally, a comprehensive and systematic exposition of the geological development history of this region since the Jurassic period is presented.
The corrosion inhibiting behavior of 907A steel,which was covered with thin inhibitor layers in moist seawater atmosphere,was studied.The electrochemical measurements,including EIS method and the coulostatic method,were used to atmospheric corrosioed monitor(ACM)under thin inhibitor layers to determine its corrosion rate.The results shown that the application of electrochemical methods such as the coulostatic technique and EIS could readily detect the on going process of film formation. Hence, the rapid evaluation of the thin inhibitor layers for 907A steel might be possible.
Gedaxiang Basin in Tibet is located in the south-eastern section of Gangdisi structural belt, with a typical geological and tectonic environment and a commonly developed tectonic pattern in plateau area. By studying the structural geological environment of Geda Township area and analyzing its internal geology, it can be seen that: (1) Six large-scale faults developed in the area control the basic geological and tectonic structure of the working area and affect the spatial structure of the area; The fault development direction is mainly north-south, mostly brittle faults at shallow surface level, and a few of them are east-west orientated. Most of the faults in the region are caused by the development of geological and tectonic activities in the Himalayan period, and the ones that developed later are the north-south oriented positive faults formed by the extension movement in the late Himalayan period. (2) There are three periods of tectonic environment evolution in the area of the evolutionary history, since Jurassic: the first period is the late Yanshan period, tectonic activity for the extrusion environment, the formation of north-south fold deformation under the compression environment; The second stage is early to middle mountain stage, which formed large scale EW-trending nappe structure and thrust fault, and the regional stress background is compressional environment. The third stage is the late Alpine stage, forming a series of tectonic systems of grabens and normal faults with SN strike, which were mainly formed by geological activities under the extensional system. The results of this study provide a reference for distinguishing the trace of geological rock group in the tectonic evolution of the Himalayan tectonic period.
The study on the genetic and geochemical characteristics of volcanic rocks of the Cretaceous-Paleogene Dienzhong Formation in central and southern Tibet is of great significance for the establishment of magma evolution sequence in the working area. The volcanic rocks of Dianzhong Formation in Geda area can be roughly divided into dite, andesite and rhyolite. Zircon U-Pb isotopic dating results show that the weighted average age of Pb206/U238 of oligopleural rhyolite and Andesite samples is 65. 5±2. 3Ma (MSWD=2. 0) and 68. 7±3. 1Ma (MSWD=2. 0) , respectively. This indicates that the middle acid volcanic rocks of Dianzhong Formation erupted from Late Cretaceous to Paleocene. Geochemical analysis of rocks shows that the acidic volcanic rocks in Dianzhong Formation are a set of meta-aluminous-peraluminouscalc- alkaline andesite-dacite-rhyolite rock assemblages. Large ion lithophile elements and light rare earth elements are enriched, and high field strength elements are deficient. In the process of magmatic evolution, there is a large amount of crystallization of plagiase or a large amount of refractory residue of plagiase, and there are a lot of continental crust materials in the volcanic rocks of the Dian Zhong Formation. Comprehensive analysis shows that the volcanic rocks of Dianzhong Formation have the chemical characteristics of continental arc volcanic rocks, and may be magmatic products in the transition stage from subduction mechanism to continental collision mechanism. Zircon U-Pb dating, in situ Lu-Hf isotope and whole rock principal and trace analysis were carried out on the acidic volcanic rocks in Dianzhong Formation, Geda Area. The aim is to study the geochemical characteristics and evolutionary origin of rocks in this area. It provides the geochemical data support for the discussion on the division of tectonic evolution stages in the study area since Jurassic.
Abstract Purpose Serum lactate dehydrogenase (LDH) level is a biomarker associated with the prognosis of breast cancer (BC) patients. However, there are no data on serum LDH levels as a dynamic marker in patients undergoing neoadjuvant chemotherapy (NAC) for BC. In the present study, we compared serum LDH levels at different periods during NAC. We related them to clinicopathologic characteristics and pathologic complete response (pCR) rates in patients with BC. Patients and methods We retrospectively analyzed the clinicopathological data and pCR rates of 691 non-metastatic BC patients from the Harbin Medical University Cancer Hospital from January 1, 2013, to December 31, 2019. Categorical data were compared using the chi-square test and Fisher's exact test for multivariate data using Logistic regression models. Any predictor variable with P < 0.05 in the univariate analysis was included in the multivariate regression analysis to study the relationship between different serum LDH level groups and pCR. Results A total of 557 patients were included in the cohort for the analysis. Before BC patients underwent NAC, a total of 510 (91.6%) patients had serum LDH levels below 230 U/L, and after completing half of the chemotherapy cycles, the number of patients with high expression of serum LDH levels gradually increased to about 37.7%. At the end of the complete cycle of chemotherapy for routine preoperative examination, 246 (44.2%) BC patients were in a state of high serum LDH expression. Patients with high expression of serum LDH levels were more likely to achieve pCR. Serum LDH levels in mid-NAC, clinical T-stage, and human epidermal growth factor receptor-2 (HER-2) expression were independent predictors of achieving pCR in patients with BC ( P < 0.05). Conclusion Our findings suggest that serum LDH level is an essential predictor of chemotherapeutic efficacy in BC patients, and we need to pay more attention to this biomarker to individualize treatment, which will help us to treat BC better and provide new targets and blueprints for our clinical treatment.
Abstract Purpose Age has been confirmed to be a very aggressive biological factor associated with the poor prognosis of breast cancer (BC) patients. But the understanding of young women's breast cancer (YWBC) is scarce. This study compares and evaluates the clinical characteristics and pCR rate after neoadjuvant chemotherapy (NAC) in YWBC and older women with BC. Patients and methods We retrospectively analyzed the clinicopathological data, molecular subtypes, chemotherapy regimen, and pCR rates of 1419 non-metastatic BC patients from the Affiliated Cancer Hospital of Harbin Medical University from January 1, 2012, to December 31, 2019. Patients were classified according to age (35 years old and below vs above 35 years old) with the clinical parameters. Categorical data were compared using the chi-square test and Fisher's exact test for multivariate data using Logistic regression models. Any predictor variable with P < 0.05 in the univariate analysis was included in the multivariate regression analysis to study the relationship between different age groups and pCR. Results A total of 879 patients in this study were eligible for analysis, and 71(8.1%) female patients were ≤ 35 years old. YWBC were more likely to get pCR (25.4%vs15.6%, P = 0.033). The proportion of patients with a higher clinical stage was higher. Compared with elderly patients, YWBC patients were more likely to undergo breast-conserving surgery (BCS), multivariate analyses found similar results in different age groups, and more patients with HER-2 positive and triple-negative breast cancer (TNBC). In the whole group, Age, PR expression, HER-2 expression, KI67 expression, and clinical stage were the independent predictors of pCR after NAC in BC patients (P < 0.05). Conclusion Our study found that age is the main factor affecting the achievement of pCR in patients with BC. YWBC has a higher clinical stage and a high proportion of HER-2 positive patients, which is the leading cause of poor prognosis. YWBC has a higher effect on chemotherapy. We need to pay more attention to this group and achieve individualized treatment, which will help us treat BC better and provide new targets and blueprints for our clinical therapy.
Liquid dispersion,described by the parameters of gas/liquid/solid three-phase boundary(TPB) zone of dispersed liquid on a metal surface,is an important property of liquid state influencing corrosion behavior of metals in gas/liquid/solid multiphase corrosion systems.In our paper,the characterisation of cathodic oxygen reduction process in TPB zone was discussed,and a model describing the cathodic process of TPB zone was developed.On this basis,the relationship between the cathodic limiting current and the TPB parameters was studied,and the simulation results were in good agreement with the experimental data.The role of liquid dispersion in atmospheric and sandy soil corrosion systems was also simulated.
The study of metamorphic rocks and deformation and metamorphic features in Gangdise-Lhasa metamorphic zone is helpful for the establishment of regional tectonic framework and the discussion of the evolution history of the region, which will provide new basic data for the study of geological structure evolution in the Qinghai-Tibet Plateau. There are few studies on metamorphic rocks in the northern area of Lhasa, Tibet. This paper summarizes and studies them from the perspective of petrography, and briefly discusses the stages of deformation and metamorphism. The area is divided into two metamorphic belts, which are divided into Yebagou-Gandansi metamorphic belt and Shexing-Binjiaolin metamorphic belt from south to north. The types of metamorphic rocks are slate, kyanite and schist. The dynamic metamorphism is manifested as brittle deformation and ductile deformation. The dynamic metamorphic rock belt developed in the area is several kilometers long, which basically belongs to the low green schist facies belt. The metamorphism in the area occurs under the geological background of the northward subduction, subduction and collision of the Neotethys oceanic crust plate. And with the change of tectonic environment and heat flow, different metamorphisms are produced in different geological development stages.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)