32 research outputs found

    Response of granite residual soil slopes under dry–wet cycles

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    Granite residual soil is widely distributed in the southern coastal areas of China, and the slopes of granite residual soil are prone to instability and failure under the alternating action of rainfall and drying, which will cause great disasters to human society. In order to study the response mechanism of granite residual soil slopes under the alternating action of rainfall–drying–static–rainfall (RDSR), this study conducted indoor scaling model tests to analyze the response during dry and wet cycles. This study presented the response process of the slope under the influence of dry and wet cycles and discussed the change laws of slope deformation, water content, and matric suction. The results show that, under the alternating action of rainfall–drying–static–rainfall, 1) the network cracks on the slope form a dominant channel for rainwater seepage, which is the main reason for the rapid decline in soil anti-sliding ability within a short time; 2) at a rainfall intensity of 1.7–2.4 mm/min, the erosion effect of rain on the slope is obviously stronger than that of osmotic erosion, and the surface erosion failure of the granite residual soil slope tends to occur without an obvious sliding surface; 3) after the loss of matric suction over a certain period, the phenomenon of channeling and loss failure on the slope serve as a sufficient condition for slope instability failure but is not a necessary condition. The above research results are expected to provide the basis and reference for preventing and controlling landslide hazards in granite residual soil slopes under similar conditions

    Identification of an unfolded protein response-related signature for predicting the prognosis of pancreatic ductal adenocarcinoma

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    BackgroundPancreatic ductal adenocarcinoma (PDAC) is a highly aggressive lethal malignancy. An effective prognosis prediction model is urgently needed for treatment optimization.MethodsThe differentially expressed unfolded protein response (UPR)‒related genes between pancreatic tumor and normal tissue were analyzed using the TCGA-PDAC dataset, and these genes that overlapped with UPR‒related prognostic genes from the E-MTAB-6134 dataset were further analyzed. Univariate, LASSO and multivariate Cox regression analyses were applied to establish a prognostic gene signature, which was evaluated by Kaplan‒Meier curve and receiver operating characteristic (ROC) analyses. E‒MTAB‒6134 was set as the training dataset, while TCGA-PDAC, GSE21501 and ICGC-PACA-AU were used for external validation. Subsequently, a nomogram integrating risk scores and clinical parameters was established, and gene set enrichment analysis (GSEA), tumor immunity analysis and drug sensitivity analysis were conducted.ResultsA UPR-related signature comprising twelve genes was constructed and divided PDAC patients into high- and low-risk groups based on the median risk score. The UPR-related signature accurately predicted the prognosis and acted as an independent prognostic factor of PDAC patients, and the AUCs of the UPR-related signature in predicting PDAC prognosis at 1, 2 and 3 years were all more than 0.7 in the training and validation datasets. The UPR-related signature showed excellent performance in outcome prediction even in different clinicopathological subgroups, including the female (p<0.0001), male (p<0.0001), grade 1/2 (p<0.0001), grade 3 (p=0.028), N0 (p=0.043), N1 (p<0.001), and R0 (p<0.0001) groups. Furthermore, multiple immune-related pathways were enriched in the low-risk group, and risk scores in the low-risk group were also associated with significantly higher levels of tumor-infiltrating lymphocytes (TILs). In addition, DepMap drug sensitivity analysis and our validation experiment showed that PDAC cell lines with high UPR-related risk scores or UPR activation are more sensitive to floxuridine, which is used as an antineoplastic agent.ConclusionHerein, we identified a novel UPR-related prognostic signature that showed high value in predicting survival in patients with PDAC. Targeting these UPR-related genes might be an alternative for PDAC therapy. Further experimental studies are required to reveal how these genes mediate ER stress and PDAC progression

    Hierarchical graph contrastive learning of local and global presentation for multimodal sentiment analysis

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    Abstract Multi-modal sentiment analysis (MSA) aims to regress or classify the overall sentiment of utterances through acoustic, visual, and textual cues. However, most of the existing efforts have focused on developing the expressive ability of neural networks to learn the representation of multi-modal information within a single utterance, without considering the global co-occurrence characteristics of the dataset. To alleviate the above issue, in this paper, we propose a novel hierarchical graph contrastive learning framework for MSA, aiming to explore the local and global representations of a single utterance for multimodal sentiment extraction and the intricate relations between them. Specifically, regarding to each modality, we extract the discrete embedding representation of each modality, which includes the global co-occurrence features of each modality. Based on it, for each utterance, we build two graphs: local level graph and global level graph to account for the level-specific sentiment implications. Then, two graph contrastive learning strategies is adopted to explore the different potential presentations based on graph augmentations respectively. Furthermore, we design a cross-level comparative learning for learning local and global potential representations of complex relationships

    High Sensitive Refractive Index Sensor Based on Cladding Etched Photonic Crystal Fiber Mach-Zehnder Interferometer

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    Abstract A high sensitive refractive index sensor based on the cladding etched photonic crystal fiber (PCF) Mach-Zehnder interferometer (MZI) is proposed, which is spliced a section of photonic crystal fiber between two single modes fibers (SMFs).The interference fringe of the MZI shifts with the variation of the ambient refractive index (RI). It is found that the RI sensitivity slightly decrease with an increase in the interference length. The sensitivities of MZI with 35 mm PCF, 40 mm PCF, and 45 mm PCF are 106.19 nm/RIU, 93.33 nm/RIU, and 73.64 nm/RIU, respectively, in the range of 1.333 to 1.381. After etched, the RI sensitivity of the MZI could be improved obviously. The RI sensitivities of the MZI with 35 mm PCF are up to 211.53 nm/RIU and 359.37 nm/RIU when the cladding diameter decreases to 112 μm and 91 μm, respectively. Moreover, the sensor is insensitive to temperature, and the measured sensitivity is only 9.21 pm/°C with the range from 20°C to 500°C. In addition, the sensor has advantage of simple fabrication, low cost, and high RI sensitivity

    Recovery Responses of Central Hemodynamics in Basketball Athletes and Controls After the Bruce Test

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    Purpose: It is commonly believed that central hemodynamics is closely associated with the presence of cardiovascular events. However, controversial data exist on the acute response of competitive sports on central hemodynamics. Moreover, the central hemodynamic response to exercise is too transient to be investigated. Therefore, this study aimed to investigate the central hemodynamic response in young basketball athletes and controls after 1 h recovery after exercise. Methods: Fifteen young basketball athletes and fifteen aged-matched controls were recruited to perform the Bruce test. Central hemodynamics were measured and calculated, including heart rate (HR), aortic systolic, diastolic, and pulse pressure (ASP, ADP, and APP), ejection duration (ED), sub-endocardial viability ratio (SEVR), central augmentation index (AIx), and AIx@HR75. Intra-group and inter-group differences were analyzed by two-way repeated measures ANOVA. Results: ASP significantly decreased at 10 min after exercise in athletes, while it markedly declined at 15 min after exercise in controls (p < 0.01). Additionally, only in the athlete group, ADP significantly decreased at 50 min and at 1 h after exercise. AIx was also significantly reduced at 1–2, 20, 30, and 40 min after exercise (all p < 0.05). Moreover, there were significant differences in the changes of these parameters between the two groups at these measurement points (p < 0.05). SEVR significantly recovered to the baseline level after 30 min, while ED and HR returned to baseline levels at 40 min after exercise in both groups. Conclusion: Sustained decrease of aortic BPs was sooner after the cessation of exercise in athletes than in controls, and changes of aortic stiffness were more evident in athletes than those in controls during the 1 h recovery period. Additionally, SEVR returned to the baseline sooner than ED and HR in athletes

    Spatial Distribution of Diffuse Attenuation of Photosynthetic Active Radiation and Its Main Regulating Factors in Inland Waters of Northeast China

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    Light availability in lakes or reservoirs is affected by optically active components (OACs) in the water. Light plays a key role in the distribution of phytoplankton and hydrophytes, thus, is a good indicator of the trophic state of an aquatic system. Diffuse attenuation of photosynthetic active radiation (PAR) (Kd(PAR)) is commonly used to quantitatively assess the light availability. The PAR and the concentration of OACs were measured at 206 sites, which covered 26 lakes and reservoirs in Northeast China. The spatial distribution of Kd(PAR) was depicted and its association with the OACs was assessed by grey incidences(GIs) and linear regression analysis. Kd(PAR) varied from 0.45 to 15.04 m−1. This investigation revealed that reservoirs in the east part of Northeast China were clear with small Kd(PAR) values, while lakes located in plain areas, where the source of total suspended matter (TSM) varied, displayed high Kd(PAR) values. The GIs and linear regression analysis indicated that the TSM was the dominant factor in determining Kd(PAR) values and best correlated with Kd(PAR) (R2 = 0.906, RMSE = 0.709). Most importantly, we have demonstrated that the TSM concentration is a reliable measurement for the estimation of the Kd(PAR) as 74% of the data produced a relative error (RE) of less than 0.4 in a leave-one-out cross validation (LOO-CV) analysis. Spatial transferability assessment of the model also revealed that TSM performed well as a determining factor of the Kd(PAR) for the majority of the lakes. However, a few exceptions were identified where the optically regulating dominant factors were chlorophyll-a (Chl-a) and/or the chromophroic dissolved organic matter (CDOM). These extreme cases represent lakes with exceptionally clear waters

    Spatiotemporal Variations of Lake Surface Temperature across the Tibetan Plateau Using MODIS LST Product

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    Satellite remote sensing provides a powerful tool for assessing lake water surface temperature (LWST) variations, particularly for large water bodies that reside in remote areas. In this study, the MODIS land surface temperature (LST) product level 3 (MOD11A2) was used to investigate the spatiotemporal variation of LWST for 56 large lakes across the Tibetan Plateau and examine the factors affecting the LWST variations during 2000–2015. The results show that the annual cycles of LWST across the Tibetan Plateau ranged from −19.5 °C in early February to 25.1 °C in late July. Obvious diurnal temperature differences (DTDs) were observed for various lakes, ranging from 1.3 to 8.9 °C in summer, and large and deep lakes show less DTDs variations. Overall, a LWST trend cannot be detected for the 56 lakes in the plateau over the past 15 years. However, 38 (68%) lakes show a temperature decrease trend with a mean rate of −0.06 °C/year, and 18 (32%) lakes show a warming rate of (0.04 °C/year) based on daytime MODIS measurements. With respect to nighttime measurements, 27 (48%) lakes demonstrate a temperature increase with a mean rate of 0.051 °C/year, and 29 (52%) lakes exhibit a temperature decrease trend with a mean rate of −0.062 °C/year. The rate of LWST change was statistically significant for 19 (21) lakes, including three (eight) warming and 17 (13) cooling lakes for daytime (nighttime) measurements, respectively. This investigation indicates that lake depth and area (volume), attitude, geographical location and water supply sources affect the spatiotemporal variations of LWST across the Tibetan Plateau

    Emergency rapid assessment of landslides induced by the Luding MS6.8 earthquake in Sichuan of China

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    Seismic landslides can seriously aggravate the losses of earthquake disasters. Therefore, it is of great significance to assessment the distribution of earthquake induced landslides for emergency relief. In this paper, based on the 30 m resolution DEM and regional geologic data with a scale of 1∶500 000, emergency rapid assessment of earthquake induced landslides is carried out using the Newmark cumulative displacement model for the 5 September 2022 Luding MS6.8 earthquake, China. The results show that the earthquake induced landslides are relatively serious in this earthquake. The high hazard zones of the coseismic landslides are about 45 km2, which is mainly distributed on the two banks of the nearly east-west tributaries on the west bank of the Dadu River and the west of the Xianshuihe fault, especially along the Yanzigou, Mozigou, Hailuogou, Feishuigou gullies and the Wandong, Shiyue, Tianwan rivers, posing a great threat to the lives of residents and tourists. The rivers and roads in these tributaries are at high risk of being blocked by landslides. The Lengqi, Xinglong, Moxi and Detuo towns in Luding County and Tianwan, Caoke, Xinmin, Xianfeng, Xieluo and Wajiao towns in Shimian County are at high risk of landslides. The S434 Provincial Road and S211 Provincial Road along the Dadu River near the epicenter are more likely to be blocked by landslides. The predicted earthquake landslide hazard in the Gongga Snow Mountain area is medium, but it is necessary to pay attention to the risks of long range and high position landslide disaster (chain), such as ice avalanche and rock avalanche. Comparison between the distribution of induced landslides in zones with intensity VIII and IX obtained from post-earthquake emergency investigation and remote sensing interpretation shows that the obtained displacements can well reflect the macro distribution of coseismic landslides along the tributaries on the west bank of the Dadu River, but cannot be exerted effectively around the edge of the Moxi platform and the banks of the main stream of Dadu River, which can be enhanced through the improvement of large scale of geologic maps and high quality topography data. The results can provide reference for valuable timely reference information on post-earthquake reconstruction planning and long-time activity of post-earthquake geohazard and risk recognition of landslide disaster chains
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