25 research outputs found
Durability and microstructure of steam cured and autoclaved PHC pipe piles
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Effects of two different curing regimes (steam curing and autoclaved curing) on durability of pre-stressed high-strength concrete (PHC) pipe piles with fly ash (FA) had been investigated. The chloride penetration, salt and frost resistance performances of PHC pipe piles with these two curing regimes were tested. The results showed that the chloride ion permeability coefficient of steam cured sample at 85 °C for 4.5 h was decreased by 97.13% compared with that of autoclaved one, these steam cured sample could stand 150 times of salts (5% Na
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+ 3.5% NaCl solution) corrosion tests and 550 times freeze-thaw tests. The pore structural and micro-cracking analysis of samples with three water to binder ratios (0.21, 0.23, 0.25) revealed that the mean total porosity values of these steam cured sample were about 5%, which was less than half of that of autoclaved samples. The dipping dyeing test showed that the mean micro-cracks width, length and the density of the steam cured samples were less than that of the autoclaved samples. The results supported that by optimizing the mix ratio and curing regime the PHC pipe piles could be prepared with satisfied mechanical and durability performances. So a feasible low-carbon manufacturing technology for PHC pipe piles was provided.
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Durability and microstructure of steam cured and autoclaved PHC pipe piles
Effects of two different curing regimes (steam curing and autoclaved curing) on durability of pre-stressed high-strength concrete (PHC) pipe piles with fly ash (FA) had been investigated. The chloride penetration, salt and frost resistance performances of PHC pipe piles with these two curing regimes were tested. The results showed that the chloride ion permeability coefficient of steam cured sample at 85 °C for 4.5 h was decreased by 97.13% compared with that of autoclaved one, these steam cured sample could stand 150 times of salts (5% Na 2 SO 4 + 3.5% NaCl solution) corrosion tests and 550 times freeze-thaw tests. The pore structural and micro-cracking analysis of samples with three water to binder ratios (0.21, 0.23, 0.25) revealed that the mean total porosity values of these steam cured sample were about 5%, which was less than half of that of autoclaved samples. The dipping dyeing test showed that the mean micro-cracks width, length and the density of the steam cured samples were less than that of the autoclaved samples. The results supported that by optimizing the mix ratio and curing regime the PHC pipe piles could be prepared with satisfied mechanical and durability performances. So a feasible low-carbon manufacturing technology for PHC pipe piles was provided
Looking into Endoplasmic Reticulum Stress: The Key to Drug-Resistance of Multiple Myeloma?
Multiple myeloma (MM) is the second most common hematologic malignancy, resulting from the clonal proliferation of malignant plasma cells within the bone marrow. Despite significant advances that have been made with novel drugs over the past two decades, MM patients often develop therapy resistance, especially to bortezomib, the first-in-class proteasome inhibitor that was approved for treatment of MM. As highly secretory monoclonal protein-producing cells, MM cells are characterized by uploaded endoplasmic reticulum stress (ERS), and rely heavily on the ERS response for survival. Great efforts have been made to illustrate how MM cells adapt to therapeutic stresses through modulating the ERS response. In this review, we summarize current knowledge on the mechanisms by which ERS response pathways influence MM cell fate and response to treatment. Moreover, based on promising results obtained in preclinical studies, we discuss the prospect of applying ERS modulators to overcome drug resistance in MM
Intact coronary and myocardial functions after 24 hours of non-ischemic heart preservation
Objectives. The aim of this study was to investigate endothelium dependent relaxation (EDR) in coronary artery and the myocardial contractility after 24 h of non-ischemic heart preservation (NIHP). Design. Explanted cardioplegic hearts from six pigs were preserved by NIHP for 24 h. The perfusion medium consisted of an albumin containing hyperoncotic cardioplegic nutrition-hormone solution with erythrocytes to a hematocrit of 10%. Coronary artery ring segments were then studied in organ baths. Thromboxane A2 was used for vasocontraction and Substance P to elicit endothelium dependent relaxation. A heart trabecula from the right ventricle was mounted in an organ bath and a special stimulation protocol was used to characterize myocardial contractility. Fresh cardioplegic hearts from 11 pigs were used as controls. The water content of the hearts was calculated. Results. There was no significant difference between NIHP and fresh controls regarding EDR (91.2 ± 1.2% vs 93.1 ± 1.8%). The contraction force, potentiation and calcium recirculation fraction did not differ between the groups. The water content of the myocardium was 79.3 ± 0.2% for NIHP and 79.5 ± 0.2% for controls. Conclusions. NIHP for 24 h keeps coronary artery EDR and myocardial contractility intact and causes no edema
FBXW7 Acts as an Independent Prognostic Marker and Inhibits Tumor Growth in Human Osteosarcoma
F-box and WD repeat domain-containing 7 (FBXW7) is a potent tumor suppressor in human cancers including breast cancer, colorectal cancer, gastric cancer and hepatocellular carcinoma. In this study, we found that the expressions of FBXW7 protein and mRNA levels in osteosarcoma (OS) cases were significantly lower than those in normal bone tissues. Clinical analysis indicated that FBXW7 was expressed at lower levels in OS patients with advanced clinical stage, high T classification and poor histological differentiation. Furthermore, we demonstrated that high expression of FBXW7 was correlated with a better 5-year survival of OS patients. Multivariate Cox regression analysis indicated that FBXW7 was an independent prognostic marker in OS. Our in vitro studies showed that FBXW7 overexpression inhibited cell cycle transition and cell proliferation, and promoted apoptosis in both U2OS and MG-63 cells. In a nude mouse xenograft model, FBXW7 overexpression slowed down tumor growth by inducing apoptosis and growth arrest. Mechanistically, FBXW7 inversely regulated oncoprotein c-Myc and cyclin E levels in both U2OS and MG-63 cells. Together these findings suggest that FBXW7 may serve as a prognostic biomarker and inhibit tumor progression by inducing apoptosis and growth arrest in OS
GIS-Based Three-Dimensional SPH Simulation for the 11 April 2018 Yabakei Landslide at Oita Nakatsu, Japan
Landslides are usually triggered by strong earthquakes, heavy rainfalls, or intensive human activities in common wisdom. However, an unexpected landslide occurred in the Yabakei area, Nakatsu, Oita, Japan, at the pre-dawn hour 3:50 a.m. on 11 April 2018, without any accompanying rainfall and earthquake records during the event. This catastrophic landslide was 200 m in width, 110 m in height, and 60,000 m3 in mass volume, damaging four residential buildings with fatalities of six residents at the landslide toe. Field investigation was conducted immediately to identify geological setting, hydrological condition, and landslide geomorphological characteristics. Key findings speculate that infiltration of groundwater stored in the internal fractures led to the swelling and breaking of illite and askanite in the weathered sediment rocks, resulting in the failure of the Yabakei landslide. To reproduce and explore the dynamic process of this landslide event, based on spatial GIS data, we applied the proposed three-dimensional, Herschel-Bulkley-Papanastasiou rheology model-based smooth particle hydrodynamics (HBP-SPH) method to simulate the landslide dynamic process. Buildings in the landslide area are covered by a set of surfaced cells (SC) to analyze the mass impact on the residential buildings. Results showed good accordance between observation and simulation by the proposed SC-HBP-SPH method. The landslide impact force to the residential buildings could be up to 4224.89 kN, as indicated by the simulation
Numerical Study on Soil Arching Effects of Stabilizing Piles
The Soil arching effect, the transfer of soil pressure from the yielding soil to the piles support, is a phenomena commonly encountered in geotechnical engineering for stabilizing landslides. In this paper, the (finite element method) FEM and (discontinuous deformation analysis) DDA were used to study on the soil arching effects of stabilizing piles in landslides. This paper proposes a method for two dimensional numerical simulation to perform three dimensional soil-pile interaction so that the slope angle can be considered even using a two dimensional numerical method. And then, a FEM model is built based on the FEM to investigate the soil arching effect on stress and deformation distribution in detail for different pile intervals and pile width. The results shown that the soil arching effects do exist and the height of soil arching becomes larger when the pile interval is larger; the soil arching height does not change when the pile width increases, while the shape of soil arching changes. Finally, in order to investigate the failure condition of a stabilizing pile enforced slope, DDA is applied. The results comparison between the example of FEM model and DDA model is conducted to verify the DDA application of solving the continuity problem. Then the failure of model is also analyzed by the simulation of DDA. The results show that the DDA has accordant results with FEM for the small deformation problems, and the DDA can be applied to simulate the large deformation and failure problems of soil arching which cannot be done by FEM
Microbial Insight into a Pilot-Scale Enhanced Two-Stage High-Solid Anaerobic Digestion System Treating Waste Activated Sludge
High solid anaerobic digestion (HSAD) is a rapidly developed anaerobic digestion technique for treating municipal sludge, and has been widely used in Europe and Asia. Recently, the enhanced HSAD process with thermal treatment showed its advantages in both methane production and VS reduction. However, the understanding of the microbial community is still poor. This study investigated microbial communities in a pilot enhanced two-stage HSAD system that degraded waste activated sludge at 9% solid content. The system employed process “thermal pre-treatment (TPT) at 70 °C, thermophilic anaerobic digestion (TAD), and mesophilic anaerobic digestion (MAD)”. Hydrogenotrophic methanogens Methanothermobacter spp. dominated the system with relative abundance up to about 100% in both TAD and MAD. Syntrophic acetate oxidation (SAO) bacteria were discovered in TAD, and they converted acetate into H2 and CO2 to support hydrogenotrophic methanogenesis. The microbial composition and conversion route of this system are derived from the high solid content and protein content in raw sludge, as well as the operational conditions. This study could facilitate the understanding of the enhanced HSAD process, and is of academic and industrial importance
Stent patency rates and prognostic factors of endovascular intervention for iliofemoral vein occlusion in post-thrombotic syndrome
Abstract Objective Post-thrombotic syndrome (PTS), an important complication of deep venous thrombosis (DVT), adversely affects patients’ quality of life. Endovascular intervention in PTS can relieve symptoms rapidly with high therapeutic value. This study mainly focuses on how to improve postoperative stent patency rates and aims to find prognostic factors impacting patency. Methods According to the specific inclusion and exclusion criteria, PTS patients who underwent endovascular intervention at the First Affiliated Hospital of Sun Yat-sen University from December 1, 2014, to December 31, 2019, were included in this single-center prospective study. Follow-up data were collected and analyzed regularly over 2 years. Results Overall, 31 PTS patients were enrolled in the study. The mean age of these patients was 55.39 ± 11.81, including 19 male patients. Stent implantation was successful in 22 PTS patients, with a technical success rate of 70.97%. The average Villalta scores of the stent-implanted group and the non-stent-implanted group were 5.95 ± 2.57 and 5.78 ± 2.95, respectively, with no significant difference observed. In the stent-implanted group, the perioperative patency rate was 81.81% (18/22), and the follow-up patency rates were 68.18% (15/22) within 3 months, 59.09% (13/22) within 6 months, 45.45% (10/22) within 1 year, and 36.36% (8/22) within 2 years. Based on the stent placement segments, the 22 PTS patients were divided into two subgroups: the iliofemoral vein balloon dilation + iliofemoral vein stent implantation (FV-S) subgroup and the iliofemoral vein balloon dilation + iliac vein stent implantation (FV-B) subgroup. In the FV-S subgroup, the perioperative patency rate was 100.00% (14/14), and the follow-up patency rates were 85.71% (12/14), 71.43% (10/14), 57.14% (8/14) and 50.00% (7/14), which were higher than those for overall stent patency of all patients. The postoperative patency rates in the FV-B subgroup were 50.00% (4/8), 37.50% (3/8), 37.50% (3/8), 25.00% (2/8), and 12.50% (1/8). The secondary postoperative patency rates in the FV-B subgroup were 100.00% (8/8), 87.50% (7/8), 75.00% (6/8), 62.50% (5/8) and 50.00% (4/8). Conclusions For PTS patients with iliofemoral vein occlusion but patent inflow, iliofemoral vein stent implantation is a more efficient therapeutic option than iliofemoral vein balloon dilation with iliac vein stent implantation for PTS patients