•Tectonic subsidence analysis by backstripping method is based on well and seismic data.•Two events of rapid post-rift subsidence were identified.•Possible mechanisms for subsidence events were ...explained.•This study is significant for regional tectonic analysis and petroleum exploration.
Data from 26 drill wells and 27 regional seismic profiles were integrated to investigate the timing, phase and origin of the post-rift subsidence in the middle to eastern Pearl River Mouth Basin (PRMB) of the northern South China Sea using the traditional 1-D backstripping technique. Different from previous research of backstripped tectonic subsidence in the basin, we calculated the tectonic subsidence using the newly built local porosity-depth relationships for decompaction and updated sedimentological and paleontological data for paleobathymetry reconstruction. Well-data based subsidence curves reveal a roughly decaying pattern in both the magnitude and rate of the post-rift subsidence in the PRMB, which is in accordance with the general decreasing trend of the thermal subsidence typical of a passive margin. Two events of rapid post-rift tectonic subsidence were identified, which occurred in the Early to early Middle Miocene and the Pliocene. The timing of the first rapid post-rift subsidence event varies and is earlier in the southern rather than northern part of the basin. Additionally, the amplitude of contemporaneous tectonic subsidence is greater in the southern part of the basin. The second rapid tectonic subsidence event occurred simultaneously in both the southern and northern parts of the basin, with the amplitude of subsidence being much greater in the southern part. We associate the first rapid subsidence event with the southward jump of the South China Sea spreading ridge, which occurred between the Oligocene and Early Miocene, while the second event with the arc-continent collision at Taiwan since the latest Late Miocene. The southern PRMB in the deep-water slope area shows a much higher magnitude of tectonic subsidence in both events than its northern counterpart in the shelf area, which could be associated with its much thinner lithosphere. The latter could cause upswelling of denser lower crust and upper mantle material, resulting in more rapid tectonic subsidence in the southern PRMB.
Although typical and atypical CT image findings of COVID-19 are reported in current studies, the CT image features of COVID-19 overlap with those of viral pneumonia and other respiratory diseases. ...Hence, it is difficult to make an exclusive diagnosis.
Thirty confirmed cases of COVID-19 and forty-three cases of other aetiology or clinically confirmed non-COVID-19 in a general hospital were included. The clinical data including age, sex, exposure history, laboratory parameters and aetiological diagnosis of all patients were collected. Seven positive signs (posterior part/lower lobe predilection, bilateral involvement, rounded GGO, subpleural bandlike GGO, crazy-paving pattern, peripheral distribution, and GGO +/- consolidation) from significant COVID-19 CT image features and four negative signs (only one lobe involvement, only central distribution, tree-in-bud sign, and bronchial wall thickening) from other non-COVID-19 pneumonia were used. The scoring analysis of CT features was compared between the two groups (COVID-19 and non-COVID-19).
Older age, symptoms of diarrhoea, exposure history related to Wuhan, and a lower white blood cell and lymphocyte count were significantly suggestive of COVID-19 rather than non-COVID-19 (p < 0.05). The receiver operating characteristic (ROC) curve of the combined CT image features analysis revealed that the area under the curve (AUC) of the scoring system was 0.854. These cut-off values yielded a sensitivity of 56.67% and a specificity of 95.35% for a score > 4, a sensitivity of 100% and a specificity of 23.26% for a score > 0, and a sensitivity of 86.67% and a specificity of 67.44% for a score > 2.
With a simple and practical scoring system based on CT imaging features, we can make a hierarchical diagnosis of COVID-19 and non-COVID-19 with different management suggestions.
To establish and verify a predictive model involving multiparameter MRI and clinical manifestations for predicting synchronous lung metastases (SLM) in osteosarcoma.
Seventy-eight consecutive ...patients with osteosarcoma (training dataset, n = 54; validation dataset, n = 24) were enrolled in our study. MRI features were extracted from the T1-weighted image (T1WI), T2-weighted image (T2WI), and contrast-enhanced T1-weighted image (CE-T1WI) of each patient. Least absolute shrinkage and selection operator (LASSO) regression and multifactor logistic regression were performed to select key features and build radiomics models in conjunction with logistic regression (LR) and support vector machine (SVM) classifiers. Eight individual models based on T1WI, T2WI, CE-T1WI, T1WI+T2WI, T1WI+CE-T1WI, T2WI+CE-T1WI, T1WI+T2WI+CE-T1WI, and clinical features, as well as two combined models, were built. The area under the receiver operating characteristic curve (AUC), sensitivity and specificity were employed to assess the different models.
Tumor size was the most significant univariate clinical indicator (1). The AUC values of the LR predictive model based on T1WI, T2WI, CE-T1WI, T1WI+T2WI, T1WI+CE-T1WI, T2WI+CE-T1WI, and T1WI+T2WI+CE-T1WI were 0.686, 0.85, 0.87, 0.879, 0.736, 0.85, and 0.914, respectively (2). The AUC values of the SVM predictive model based on T1WI, T2WI, CE-T1WI, T1WI+T2WI, T1WI +CE-T1WI, T2WI +CE-T1WI, and T1WI+T2WI+CE-T1WI were 0.629, 0.829, 0.771, 0.879, 0.643, 0.829, and 0.929, respectively (3). The AUC values of the clinical, combined 1 (clinical and LR-radiomics) and combined 2 (clinical and SVM-radiomics) predictive models were 0.779, 0.957, and 0.943, respectively.
The combined model exhibited good performance in predicting osteosarcoma SLM and may be helpful in clinical decision-making.
This study investigated accuracy and consistency of epicardial adipose tissue (EAT) quantification in non-ECG-gated chest computed tomography (CT) scans.
EAT volume was semi-automatically quantified ...using a standard Hounsfield unit threshold (- 190, - 30) in three independent cohorts: (1) Cohort 1 (N = 49): paired 120 kVp ECG-gated cardiac non-contrast CT (NCCT) and 120 kVp non-ECG-gated chest NCCT; (2) Cohort 2 (N = 34): paired 120 kVp cardiac NCCT and 100 kVp non-ECG-gated chest NCCT; (3) Cohort 3 (N = 32): paired non-ECG-gated chest NCCT and chest contrast-enhanced CT (CECT) datasets (including arterial phase and venous phase). Images were reconstructed with the slice thicknesses of 1.25 mm and 5 mm in the chest CT datasets, and 3 mm in the cardiac NCCT datasets.
In Cohort 1, the chest NCCT-1.25 mm EAT volume was similar to the cardiac NCCT EAT volume, while chest NCCT-5 mm underestimated the EAT volume by 7.5%. In Cohort 2, 100 kVp chest NCCT-1.25 mm were 13.2% larger than 120 kVp cardiac NCCT EAT volumes. In Cohort 3, the chest arterial CECT and venous CECT dataset underestimated EAT volumes by ~ 28% and ~ 18%, relative to chest NCCT datasets. All chest CT-derived EAT volumes were similarly associated with significant coronary atherosclerosis with cardiac CT counterparts.
The 120 kVp non-ECG-gated chest NCCT-1.25 mm images produced EAT volumes comparable to cardiac NCCT. Chest CT EAT volumes derived from consistent imaging settings are excellent alternatives to the cardiac NCCT to investigate their association with coronary artery disease.
Backgroud: Radiotherapy (RT) with or without concurrent chemotherapy is regarded as the standard therapy for locally advanced cervical cancer (International Federation of Gynecology and Obstetrics ...FIGO stage IB2 and above). However, markedly different responses to RT are seen among patients with similar FIGO stages.The study aimed to evaluate the peripheral blood inflammation indicators that may have predictive value for treatment response in cervical cancer patients referred for RT. Methods: This was a retrospective study that enrolled 75 patients who had stages IB2 to IVA cervical cancer, and who underwent RT alone or concurrent chemoradiation therapy (CCRT). All patients were treated at the department of Clinical Oncology of the University of Hong Kong-Shenzhen hospital between November 2015 and April 2020. The endpoint was treatment response assessed by magnetic resonance imaging (MRI) according to the Response EvaluationCriteria in Solid Tumors (RECIST). Multivariate logistic regression models were used to identify predicting values of peripheral blood inflammation indicators, including the systemic immune-inflammation index (SII), neutrophil/lymphocyte ratio (NLR), tumor-related leukocytosis (TRL), platelet/lymphocyte ratio (PLR) and monocyte/lymphocyte ratio (MLR). Results: The percentage of complete response (CR) was significantly different between different groups of peripheral blood inflammation indicators. The percentage of CR was 64.3%, 57.9%, 81.8% and 48.3% respectively in low SII, NLR, PLR and MLR groups, which was significantly higher than in the high SII group (34.0%), high NLR group (32.4%), high PLR group (30.2%) and high MLR group (35.3%). Multivariate logistic regression revealed that the TRL and PLR were significant prognostic factors for treatment response with an odds ratio of 0.18 (95% confidence interval 95% CI 0.04–0.77) for TRL and 16.36 (95% CI 3.67–73.04) for PLR. Conclusions: The result revealed that a TRL-negative or lower PLR tumor was associated with radiosensitivity, which may provide important information for the prediction of treatment response in cervical cancer patients referred for RT.
Canopy temperature is an important physiological and ecological characteristic of rice plants. It can comprehensively reflect their individual characteristics, such as their adaptability to the ...environment and the quality of the population. This paper reviews influencing factors, variation patterns, practical applications, formation processes, and measurement techniques of rice canopy temperature. Moreover, we analyzed the weaknesses of current studies on this topic, proposed improvements to the existing methods and techniques used to measure rice canopy temperature, and systematically assessed the effects of canopy temperature on rice production. This study provides a theoretical support for the construction of an auxiliary decision‐making system to guide rice crop production practices.
This paper reviews the formation process, influencing factors, variation patterns, practical applications, and measurement techniques of rice canopy temperature. Moreover, this study analyzes the drawbacks in current studies on rice canopy temperature, proposes to strengthen studies on the influencing mechanism of rice canopy temperature, improves the methods and techniques of rice canopy temperature measurement, and systematically assess the effect of canopy temperature on rice production, to construct a systemic analysis and auxiliary decision‐making system for rice production with canopy temperature as the main marker.
Land use change is a major predictor for variations in soil bacteria, which plays a key role in maintaining soil multifunctionality and function of terrestrial ecosystems. The effects of land use ...change on the soil bacterial community in an alpine region at the Qinghai-Tibetan Plateau (QTP) were still unclear. In this study, we investigated soil bacterial profiles under grazed grassland, enclosed grassland, continuous cropland, rotation cropland and abandoned cropland in the Tianzhu alpine agro-pastoral ecotone. Our results showed that Proteobacteria, Acidobacteria and Actinobacteria were the most three abundant phyla regardless of land use change, accounting for over 60% of the total. Cultivation declined soil bacterial alpha diversity without recovering even after abandonment. Over 73% variations in bacterial diversity can be explained by soil physical and chemical properties. In addition, soil moisture could be the main driver for the difference in bacterial structure between croplands and others. Soil bulk density, pH, organic carbon and total nitrogen contents seem to be the key factors determining the difference in bacterial structure between abandoned croplands and others. Our results have implications for comprehensive understanding about the responses of the soil bacterial community to land use change in alpine regions.
To determine the predictive CT imaging features for diagnosis in patients with primary pulmonary mucoepidermoid carcinomas (PMECs).
CT imaging features of 37 patients with primary PMECs, 76 with ...squamous cell carcinomas (SCCs) and 78 with adenocarcinomas were retrospectively reviewed. The difference of CT features among the PMECs, SCCs and adenocarcinomas was analyzed using univariate analysis, followed by multinomial logistic regression and receiver operating characteristic (ROC) curve analysis.
CT imaging features including tumor size, location, margin, shape, necrosis and degree of enhancement were significant different among the PMECs, SCCs and adenocarcinomas, as determined by univariate analysis (P < 0.05). Only lesion location, shape, margin and degree of enhancement remained independent factors in multinomial logistic regression analysis. ROC curve analysis showed that the area under curve of the obtained multinomial logistic regression model was 0.805 (95%CI: 0.704-0.906).
The prediction model derived from location, margin, shape and degree of enhancement can be used for preoperative diagnosis of PMECs.
为研究不同间作方式对玉米和大豆两种作物土壤微生态、光合作用、产量和经济效益等方面的影响，本研究以大豆（绿领九号）和玉米（董浜黄金小玉米）为试验材料，设置玉米单作、大豆单作、玉米-大豆2∶2间作和玉米-大豆2∶4间作4个处理，每个处理 ...3个重复，采用完全随机区组设计，研究两种农作物在不同处理下土壤养分、叶绿素含量和土地当量比（LER）等指标的变化。结果表明，与单作相比，不同间作处理下玉米、大豆植株的根际土壤养分含量和土壤酶活性提高，其中2∶2间作下玉米过氧化氢酶活性显著提升36.96%，2∶2间作下大豆脲酶活性显著提升44.24%。就玉米而言，2∶2和2∶4间作下的土壤水分利用效率分别提高21.9、30.6个百分点。玉米、大豆不同时期叶绿素活性均提高，两种作物群体产量和经济效益也明显提升，其中2∶2间作下LER为1.40±0.21，2∶4间作下 LER为 1.44±0.14。研究表明，玉米和大豆间作可活化土壤养分库，提高土壤酶活性，增加作物的叶绿素含量，提升系统的光合作用能力，从而提高间作系统产出和经济效益。 To study the effects of different intercropping methods on soil microecology, photosynthesis, yield, and the economic benefits of maize and soybean crops. Soybean（Green Collar No.9）and corn（Dongbang golden small corn）were used as the experimental plants. Four treatments, each with three replicates, were set up：maize monocropping, soybean monocropping, corn-soybean 2∶2 intercropping, and cornsoybean 2∶4 intercropping. The variations in soil nutrients, chlorophyll content, and land equivalent ratio（LER）of the two crops under different treatments were investig
As an essential component of proteins and genetic material for all organisms, nitrogen（N） is one of the major limiting factors that control the dynamics, biodiversity and functioning of lacustrine ...wetlands, in which intensified N biogeochemical activities take place. Reactive N loaded into wetland ecosystems has been doubled due to various human activities, including industrial, agricultural activities and urbanization. The main driving mechanisms of N transport and transformation in lacustrine wetlands are categorized to pushing forces and pulling forces in this study. Geomorphology, wetland age, N concentrations, and temperature are the main pushing forces（passive forces）; whereas water table variation, oxygen concentration, other elements availability, oxidation-reduction potential（Eh） and p H, and microorganisms are the predominant pulling forces（active forces）. The direction and kinetic energy of reactions are determined by pulling forces and then are stimulated by pushing forces. These two types of forces are analyzed and discussed separately. Based on the analysis of driving mechanisms, possible solutions to wetland N pollutions are proposed at individual, regional and global scales, respectively. Additional research needs are addressed to obtain a thorough understanding of N transport and transformations in wetlands and to reduce detrimental impacts of excessive N on such fragile ecosystems.
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