Effects of aggregate size on water retention capacity and microstructure of lime-treated silty soil

International audienceLime treatment is a common technique of improving the workability and geotechnical properties of soils. In this study, the aggregate size effects on the water retention capacity and microstructure of lime-treated soil were investigated. Two soil powders with different maximum aggregate sizes (D max = 0·4 and 5 mm) were prepared and stabilised by 2% lime (by weight of dry soil). Soil samples were prepared by compaction at dry side of optimum water content (w = 17%) with a dry density of 1·65 Mg/m 3. Suction and pore size distribution were determined after different curing periods. The results obtained show that: (a) the treated soil with smaller D max presents relatively smaller modal sizes and lower frequency of macropores (10–330 μm); (b) lime addition effectively improves the soil water retention capacity and decreases both the modal sizes of macro-and micropores gradually over time. Moreover, a higher air entry value and larger water retention capacity were also observed for a smaller D max value, in agreement with the pore size distributions

Desiccation and cracking behaviour of clay layer from slurry state under wetting-drying cycles

International audienceLaboratory tests were conducted to investigate the effect of wetting-drying (W-D) cycles on the initiation and evolution of cracks in clay layer. Four identical slurry specimens were prepared and subjected to five subsequent W-D cycles. The water evaporation, surface cracks evolution and structure evolution during the W-D cycles were monitored. The effect of W-D cycles on the geometric characteristics of crack patterns was analyzed by image processing. The results show that the desiccation and cracking behaviour was significantly affected by the applied W-D cycles: the measured cracking water content c, surface crack ratio Rsc and final thickness hf of the specimen increased significantly in the first three W-D cycles and then tended to reach equilibrium; the formed crack patterns after the second W-D cycle were more irregular than that after the first W-D cycle; the increase of surface cracks was accompanied by the decrease of pore volume shrinkage during drying. In addition, it was found that the applied W-D cycles resulted in significant rearrangement of specimen structure: the initially homogeneous and non-aggregated structure was converted to a clear aggregated-structure with obvious inter-aggregate pores after the second W-D cycle; the specimen volume generally increased with increasing cycles due to the aggregation and increased porosity. The image analysis results show that the geometric characteristics of crack pattern were significantly influenced by the W-D cycles, but this influence was reduced after the third cycle. This is consistent with the observations over the experiment, and indicates that the image processing can be used for quantitatively analyzing the W-D cycle dependence of clay desiccation cracking behaviour

Resveratrol protects against sepsis induced acute kidney injury in mice by inducing Klotho mediated apoptosis inhibition

Purpose: To investigate the mechanism of resveratrol protection against sepsis-induced acute kidney injury in mice. Methods: A sepsis-induced acute kidney injury model was established in mice by cecal ligation and puncture (CLP). Sixty healthy male ICR mice were randomly divided into the sham operation (sham) group, sepsis-induced acute kidney injury model (CLP) group, CLP + low-dose (20 mg/kg) resveratrol treatment (CLP + ResL) group, CLP + high-dose (40 mg/kg) resveratrol treatment (CLP + ResH) group and CLP + Klotho (0.01 mg/kg) treatment (CLP + Klotho) group. All mice were administered treatment on the day after surgery and once every 24 h for 3 days. Various serum biochemical parameters and protein expressions were evaluated. Results: After CLP, the levels of serum creatinine (Scr) and blood urea nitrogen (BUN) increased and the pathology was exacerbated. The protein and mRNA expression levels of Klotho and Bcl-2 decreased, while those of Bax and Caspase-3 increased (p < 0.05). After resveratrol and Klotho protein intervention, Scr and BUN levels recovered, and pathological changes were alleviated. The protein and mRNA expression levels of Klotho and Bcl-2 increased, while those of Bax and Caspase-3 decreased. The conditions of the mice in CLP + ResH group and the CLP + Klotho group improved more significantly than those of the mice in the CLP + ResL group (p < 0.05). Conclusion: Resveratrol upregulates the expression of endogenous Klotho to exert its antiapoptotic effects, which can protect the kidneys of mice against sepsis-induced acute kidney injury. Thus, the compound has potentials for development for protection against acute kidney injury

A Study of the Hydro-Mechanical Behaviour of Compacted Crushed Argillite

International audienceThe argillite extracted from Bure site (France) is proposed, after being crushed and com-pacted, as a possible sealing and backfill material in the geological high-level radioactive waste disposal. In this study, the effects of the grain size distribution and the microstruc-ture on the hydro-mechanical behaviour of the compacted crushed argillite have been in-vestigated. The volume change properties were investigated by running one-dimensional compression tests under constant water content (2.4-2.8%) with loading-unloading cycles. Under various vertical stresses, water flooding tests were carried out in constant volume condition. Depending on the vertical stress level, either swelling or collapse behavior was observed in the sense that vertical stress increased or decreased upon flooding respectively. A clear effect of grain size distribution has been also identified: finer samples exhibit stiffer compression behaviour and higher swelling potential. To provide a microstructure insight into the macroscopic behaviour feature observed, both mercury intrusion po-rosimetry (MIP) and scanning electron microscopy (SEM) observations were performed, evidencing that: (i) at the same dry density, the size of inter-aggregates pores is larger for the coarser crushed material; (ii) mechanical compression only reduces the inter-aggregate porosity in the stress range considered; (iii) the micro-mechanisms governing the flooding under constant-volume condition include the swelling of the clay particles, the increase of the intra-aggregate pores and the collapse of the inter-aggregates pores. The results show a strong effect of the grain size distribution on the hydro-mechanical behaviour and thus the close link between the microstructure and the hydro-mechanical behaviour

Investigating the Swelling Pressure of Compacted Crushed-Callovo-Oxfordian Claystone

International audienceThis paper presents an experimental study on the swelling pressure of heavily compacted crushed Callovo-Oxfordian (Cox) claystone at a dry unit mass d = 2.0 Mg/m3 using four different methods: constant-volume, swell-reload, zero-swell and adjusted constant-volume method. Results show that the swelling pressure varies in the range of 1-5 MPa and depends significantly on the test method. From the constant-volume tests, it is observed that the swelling behaviour during wetting is a function of the suction and depends on both the hydration paths and wetting conditions (e.g. vapour-wetting or liquid-wetting). The swelling pressure decreases significantly with saturation time. To identify the microstructure changes of specimens before and after wetting, mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM) tests were performed. It is observed that, after wetting, the large inter-aggregate pores observed in the as-compacted specimen are no longer apparent; the whole pattern is characterized by a general swell of hydrated clay particles, rendering the soil more homogeneous. Results from MIP indicated that wetting caused a significant reduction of the entrance diameter of the dominant inter-aggregate pores from 2.1 to 0.5 m whereas intra-aggregate pores were not significantly influenced

The Pinx1 Gene Downregulates Telomerase and Inhibits Proliferation of CD133+ Cancer Stem Cells Isolated from a Nasopharyngeal Carcinoma Cell Line by Regulating Trfs and Mad1/C-Myc/p53 Pathways

Background/Aims: Cancer stem cells (CSCs) are important factors for the continuous growth, recurrence, and metastasis of malignant tumors. They are responsible for the ineffectiveness of traditional radiotherapy and chemotherapy toward malignant tumors. Currently, stem cells or side-population cells have been isolated from many cancer cell lines and malignant tumor tissues, including nasopharyngeal carcinoma. Exploring the biological characteristics of CSCs for CSC-targeted therapy has gained importance. CSCs possess higher telomerase activity; thus, the use of the gene encoding telomerase inhibitor PinX1 gene to target telomerase in CSCs and inhibit proliferation, invasion, and metastasis of CSCs has become an important means for the treatment of malignant tumors. PinX1 may regulate complex pathways, including TRF1, Mad1/c-Myc, and p53. Methods: In this study, nasopharyngeal CD133+ CSCs were sorted using CD133 immunomagnetic beads by flow cytometry The successful isolation of CD133+ CSCs was confirmed by examining their surface markers, namely CD44, NaNOG, and SOX2 as well as their ability to undergo in vivo tumorigenesis and in vitro sphere formation, proliferation, migration, and invasion. In addition, CD133+ CSCs were transfected with the constructed PinX1 overexpression plasmid or siRNA and the resulting effects on their proliferation, migration, invasion, and apoptosis were detected using cell counting kit-8 (CCK-8), transwell assay, and scratch test, respectively. Furthermore, their effects on mRNA and protein levels of TRF1, TRF2, Mad1, c-Myc, and p53 were examined using quantitative real-time PCR and western blot, respectively. Results: The overexpression of PinX1 in CD133+ CSCs significantly decreased hTERT (P < 0.001), inhibited proliferation, migration, and invasion, induced apoptosis, and significantly decreased c-Myc mRNA levels (P < 0.001), while it increased TRF1, Mad1, and p53 mRNA levels (all P < 0.001). On the other hand, PinX1 silencing in CD133+ CSCs significantly decreased TRF1, Mad1, and p53 mRNA levels (all P < 0.01), while it increased hTERT and c-Myc mRNA levels (all P < 0.05). Conclusion: These results indicate that PinX1 downregulates telomerase activity in CD133+ CSCs, inhibits its proliferation, migration, and invasion, and induces apoptosis possibly through TRF1, Mad1/c-Myc, and p53–mediated pathways

Multiple Sclerosis Identification by 14-Layer Convolutional Neural Network With Batch Normalization, Dropout, and Stochastic Pooling

Aim: Multiple sclerosis is a severe brain and/or spinal cord disease. It may lead to a wide range of symptoms. Hence, the early diagnosis and treatment is quite important.Method: This study proposed a 14-layer convolutional neural network, combined with three advanced techniques: batch normalization, dropout, and stochastic pooling. The output of the stochastic pooling was obtained via sampling from a multinomial distribution formed from the activations of each pooling region. In addition, we used data augmentation method to enhance the training set. In total 10 runs were implemented with the hold-out randomly set for each run.Results: The results showed that our 14-layer CNN secured a sensitivity of 98.77 ± 0.35%, a specificity of 98.76 ± 0.58%, and an accuracy of 98.77 ± 0.39%.Conclusion: Our results were compared with CNN using maximum pooling and average pooling. The comparison shows stochastic pooling gives better performance than other two pooling methods. Furthermore, we compared our proposed method with six state-of-the-art approaches, including five traditional artificial intelligence methods and one deep learning method. The comparison shows our method is superior to all other six state-of-the-art approaches

Alcoholism Identification Based on an AlexNet Transfer Learning Model

Aim: This paper proposes a novel alcoholism identification approach that can assist radiologists in patient diagnosis.Method: AlexNet was used as the basic transfer learning model. The global learning rate was small, at 10−4, and the iteration epoch number was at 10. The learning rate factor of replaced layers was 10 times larger than that of the transferred layers. We tested five different replacement configurations of transfer learning.Results: The experiment shows that the best performance was achieved by replacing the final fully connected layer. Our method yielded a sensitivity of 97.44%± 1.15%, a specificity of 97.41 ± 1.51%, a precision of 97.34 ± 1.49%, an accuracy of 97.42 ± 0.95%, and an F1 score of 97.37 ± 0.97% on the test set.Conclusion: This method can assist radiologists in their routine alcoholism screening of brain magnetic resonance images