35 research outputs found

    Integrated use of aerial photographs and LiDAR images for landslide and soil erosion analysis: a case study of Wakamow Valley, Moose Jaw, Canada

    Get PDF
    Urban parks and open spaces offer a unique setting that can play a vital role in improving health and quality of life in cities and towns, making cities more attractive places to live and work, and connecting residents to nature. Degradation of park facilities caused by natural processes or recreational activities requires continuous monitoring for efficient maintenance and management. Identification and continuous monitoring of areas prone to natural hazards such as landslides within an urban park are particularly important for public safety. Traditional techniques for identification and monitoring of such areas involving field surveys, being costly and time-consuming, cannot be used on a regular basis. This research explored the integrated use of aerial photographs and point cloud LiDAR data for identification of areas prone to landslide and soil erosion zones in an urban park and a conservation area known as Wakamow Valley, Moose Jaw, Saskatchewan, Canada. This study used the point cloud LiDAR of 2014 to develop a Digital Elevation Model (DEM) of the area. The accuracy of the DEM was validated through a series of well-distributed ground control points collected through a survey grade handheld GPS device. The areas prone to potential landslides and soil erosion were identified using slope analysis techniques. A typical criterion of areas having a slope greater than 35° was used for classification of potential hazardous zones. Geospatial information including land-cover, land-use, and trail system was extracted from a 2014 aerial photograph to create a base map. It has been estimated that 5.3 km along the banks of the Moose Jaw River and 8 km along the cliff of the canyon-shaped Wakamow Valley are under a possible threat of soil erosion and landslides. This portion of the valley was classified as high-risk for possible landslides and soil erosion

    Study on regional stress background and prevention of the rock burst accident on October 20th, 2018 in the Longyun Coal Industry area, Shandong, China

    Get PDF
    Objective  The stability of underground chambers such as mine tunnels and transportation tunnels is closely related to the stress environment of the surrounding rock mass and the geological conditions of the area. Analyzing the relationship between deep-seated stress and factors such as the orientation and shape of underground chambers can help to proactively mitigate the risks associated with chamber excavation.   Methods  This study, set against the background of the rock burst accident on October 20th in the Longyun Coal Industry area in Shandong, reveals the current stress environment of the shallow crustal layers in western Shandong through in-situ stress measurement and monitoring work.   Results  According to the characteristics of the current ground stress field near the Longyun coal mining area, the study investigates the regional stress background that led to the rock burst accident and proposes corresponding prevention and control suggestions from the perspective of ground stress. The results indicate that the magnitude of the principal stress generally increases linearly with depth within the measurement range, with the maximum horizontal principal stress ranging from 3.48 to 20.76 MPa and a gradient of 0.0182 MPa/m with increasing depth, while the minimum horizontal principal stress ranges from 3.44 to 14.95 MPa with a gradient of 0.0130 MPa/m. The maximum horizontal principal stress azimuth in the area ranges from NE 43°to 89°, with an average azimuth of NE 75°. The tectonic action in the shallow crust is mainly horizontal, but with increasing depth, they gradually transition to vertical.   Conclusion  The triggering mechanism of the rock burst accident in the Longyun Coal Industry area on 20th October is primarily attributed to the vertical stress exceeding the horizontal principal stress, indicating a current extensional stress environment, especially when the tunnel orientation is parallel to the direction of maximum horizontal principal stress. It is suggested that the angle between the tunnel axis and the direction of maximum horizontal principal stress in the Longyun Coal Industry area should be between 60° and 90°, and that the tunnel roof can be designed as an arch-shaped roof to ensure the stability of the tunnel rock mass

    Development and Internal Validation of a Novel Nomogram for Predicting Lymph Node Invasion for Prostate Cancer Patients Undergoing Extended Pelvic Lymph Node Dissection

    Get PDF
    BACKGROUND: Few studies have focused on the performance of Briganti 2012, Briganti 2017 and MSKCC nomograms in the Chinese population in assessing the risk of lymph node invasion(LNI) in prostate cancer(PCa) patients and identifying patients suitable for extended pelvic lymph node dissection(ePLND). We aimed to develop and validate a novel nomogram based on Chinese PCa patients treated with radical prostatectomy(RP) and ePLND for predicting LNI. METHODS: We retrospectively retrieved clinical data of 631 patients with localized PCa receiving RP and ePLND at a Chinese single tertiary referral center. All patients had detailed biopsy information from experienced uropathologist. Multivariate logistic-regression analyses were performed to identify independent factors associated with LNI. The discrimination accuracy and net-benefit of models were quantified using the area under curve(AUC) and Decision curve analysis(DCA).The nonparametric bootstrapping were used to internal validation. RESULTS: A total of 194(30.7%) patients had LNI. The median number of removed lymph nodes was 13(range, 11-18). In univariable analysis, preoperative prostate-specific antigen(PSA), clinical stage, biopsy Gleason grade group, maximum percentage of single core involvement with highest-grade PCa, percentage of positive cores, percentage of positive cores with highest-grade PCa and percentage of cores with clinically significant cancer on systematic biopsy differed significantly. The multivariable model that included preoperative PSA, clinical stage, biopsy Gleason grade group, maximum percentage of single core involvement with highest-grade PCa and percentage of cores with clinically significant cancer on systematic biopsy represented the basis for the novel nomogram. Based on a 12% cutoff, our results showed that 189(30%) patients could have avoided ePLND while only 9(4.8%) had LNI missing ePLND. Our proposed model achieved the highest AUC (proposed model vs Briganti 2012 vs Briganti 2017 vs MSKCC model: 0.83 vs 0.8 vs 0.8 vs 0.8, respectively) and highest net-benefit CONCLUSION: We developed and validated a nomogram predicting the risk of LNI based on Chinese PCa patients, which demonstrated superior performance compared with previous nomograms

    Role of SAM68 in Sunitinib Induced Renal Cell Carcinoma Apoptosis

    Get PDF
    Sunitinib is one of the first-line targeted drugs for metastatic renal cell carcinoma (RCC) with dual effects of antiangiogensis and proapoptosis. Sam68 (Src-associated in mitosis, 68 KDa), is found being involved in cell apoptosis. This article reveals that Sam68 impacts the sensitivity to sunitinib by mediating the apoptosis of RCC cells. Immunohistochemical staining indicated that the Sam68 expression levels in sunitinib sensitive tumor tissues were markedly higher than those in sunitinib resistant tumor tissues. Sunitinib induced RCC cell apoptosis in a concentration-dependent manner and inhibited the expression of total and phosphorylated Sam68 (p-Sam68). Downregulation of Sam68 expression inhibited RCC cell apoptosis induced by sunitinib. While upregulation of Sam68 expression could enhance apoptosis induced by sunitinib. Xenograft models showed that tumors in the Sam68-knockdown group did not shrink as much as those in the control group after treatment with sunitinib for 4 weeks. Together, our results suggest that Sam68 expression is associated with the sensitivity of ccRCC patients to sunitinib. Sam68 may promote cell apoptosis induced by sunitinib, and the Sam68 expression level may be a biomarker for predicting sunitinib sensitivity in ccRCC patients

    Pregnancy outcomes following natural conception and assisted reproduction treatment in women who received COVID-19 vaccination prior to conception: a population-based cohort study in China

    Get PDF
    IntroductionThe coronavirus disease-2019 (COVID-19) pandemic has swept across the world and continues to exert serious adverse effects on vulnerable populations, including pregnant women and neonates. The vaccines available at present were designed to prevent infection from COVID-19 strains and control viral spread. Although the incidence of pregnancy cycle outcomes are not likely to increase patients vaccinated prior to pregnancy compared with unvaccinated patients based on our knowledge of vaccination safety, there is no specific evidence to support this hypothesis. Therefore, the current study aimed to investigate the association between maternal vaccination prior to conception and pregnancy outcomes.MethodsWe retrospectively analyzed 2,614 women who received prenatal care and delivered in the Obstetrical Department of The First Affiliated Hospital of Anhui Medical University between February 2022 and November 2022. Of the 1,380 eligible pregnant women, 899 women who had received preconception vaccination were assigned to a vaccine group and 481 women who were not vaccinated were control group. Of the enrolled patients, 291 women received fertility treatment (141 vaccinated women, 150 unvaccinated women). The primary outcomes were pregnancy complications (hypothyroidism, gestational diabetes mellitus, pregnancy-induced hypertension, polyhydramnios, oligohydramnios, premature rupture of membranes and postpartum hemorrhage), obstetric outcomes (preterm birth rate, cesarean section rate) and neonatal outcomes (birth-weight, body length, low-birth-weight rate, rate of congenital defects, neonatal mortality and admission to the neonatal intensive care unit).ResultsThere was no significant difference in the incidence of complications during pregnancy and delivery when compared between the vaccine group and control group in either univariate- or multivariate-models. The type of vaccine was not associated with the odds of adverse pregnancy outcome. Among the women with infertility treatment, the vaccinated group and the unvaccinated group had similar pregnancy outcomes.ConclusionWomen who received COVID-19 vaccination prior to conception had similar maternal and neonatal outcomes as women who were unvaccinated. Our findings indicate that COVID-19 vaccinations can be safely administered prior to pregnancy in women who are planning pregnancy or assisted reproductive treatment. During new waves of COVID-19 infection, women who are planning pregnancy should be vaccinated as soon as possible to avoid subsequent infections

    The 5th International Conference on Biomedical Engineering and Biotechnology (ICBEB 2016)

    Get PDF

    Effects of Exogenous Caffeic Acid, L-Phenylalanine and NaCl Treatments on Main Active Components Content and In Vitro Digestion of Germinated Tartary Buckwheat

    No full text
    Germination is an effective method for improving the nutritional value of Tartary buckwheat (TB). The effects of exogenous additive treatments (caffeic acid (CA), L-phenylalanine (L-Phe), NaCl) on germination, main active component contents and antioxidant activities before and after in vitro digestion of germinated TB were investigated. Compared with the natural growth group, the T4 group (CA 17 mg/L, L-Phe 2.7 mmol/L, NaCl 2.7 mmol/L) treatment increased the germination rate (67.50%), sprout length, reducing sugar (53.05%), total flavonoid (18.36%) and total phenolic (20.96%) content, and antioxidant capacity of TB. In addition, exogenous additives treatment induced the consumption of a lot of nutrients during seed germination, resulting in a decrease in the content of soluble protein and soluble sugar. The stress degree of natural germination on seeds was higher than that of low concentrations of exogenous additives, resulting in an increase in malondialdehyde content. In vitro digestion leads to a decrease in phenolics content and antioxidant capacity, which can be alleviated by exogenous treatment. The results showed that treatment with exogenous additives was a good method to increase the nutritional value of germinated TB, which provided a theoretical basis for screening suitable growth conditions for flavonoid enrichment

    Impact of Tohoku-Oki 3.11 M9.0 Earthquake on the Fault Slip Potential of the Active Quaternary Faults in Beijing City: New Insights from In Situ Stress Monitoring Data

    No full text
    In order to ascertain the impact of the Tohoku-Oki 3.11 M9.0 earthquake on the stability of the faults in the Beijing Plain, we investigated the adjustment of the in situ stress field of the Beijing Plain after this earthquake based on in situ stress monitoring data. Then, we analyzed the stability of the five main faults in each adjustment stage of the in situ stress field based on the Mohr–Coulomb failure criteria and Byerlee’s law. Finally, we studied the fault slip potential (FSP) of the main faults under the current in situ stress field. The research results show that (1) after the Tohoku-Oki 3.11 M9.0 earthquake, the tectonic environment of the Beijing Plain area changed rapidly from nearly EW extrusion to nearly EW extension, and this state was maintained until June 2012. After this, it began to gradually adjust to the state present before the earthquake. As of September 2019, the tectonic environment has not recovered to the state present before the earthquake. (2) The ratios of shear stress to normal stress on the fault plane of the fault subsections in the three time periods before the Tohoku-Oki 3.11 M9.0 earthquake, 6 June 2012 and 8 September 2019 were 0.1–0.34, 0.28–0.52, and 0.06–0.29, respectively. It shows that the stress accumulation level of faults in the Beijing Plain area increased in a short time after the earthquake and then gradually decreased. (3) Under the current in situ stress field, most of the subsections of the five main faults have a low FSP (<5%). The areas with high FSP are mainly concentrated in the central and southeastern parts of the Beijing Plain, including the Nankou-Sunhe fault, the northern section of the Xiadian fault, and the areas where the five faults intersect

    Effects of gelatin type and concentration on the preparation and properties of freeze-dried fish oil powders

    No full text
    Abstract The effects of gelatin type (porcine skin gelatin, PSG; bovine skin gelatin, BSG; fish gelatin, FG; or cold-water fish skin gelatin, CFG) and concentration on the preparation and properties of fish oil powders were investigated in this work. The oil powders were prepared using the combination method of gelatin-sodium hexametaphosphate complex coacervation with starch sodium octenyl succinate (SSOS)-aided freeze-drying. Compared with the other gelatins, CFG—with an unobvious isoelectric point, a lower molecular weight, more hydrogen bonds, and longer gel formation time—could not form complex coacervates, which are necessary to prepare oil powders. For oil powders obtained from the other gelatins, gelatin type and concentration did not have obvious effects on microscale morphologies; they did, however, have significant effects on physicochemical properties. The highest peroxide values of the oil powders were mainly dependent on the gelatins, expressed in the following manner: PSG (153 ± 5 – 168 ± 3 meq/Kg oil) < BSG (176 ± 5 – 188 ± 1 meq/Kg oil) < FG (196 ± 11 – 201 ± 22 meq/Kg oil). Acidic and neutral pH could not dissolve the complex coacervates. However, the oil powders could be quickly dissolved to form emulsion droplets in the gastric phase, and that SSOS increased coacervate stability and promoted oil digestion during the in vitro gastrointestinal process. In sum, this study contributes fundamental information to understanding the development of fish oil solid encapsulation preparations

    Prediction and analysis on large deformation of surrounding rocks in the Muzhailing Tunnel of the Weiyuan–Wudu Expressway under high in-situ stress

    No full text
    This study aims to solve the significant deformation issue in the soft surrounding rocks under high in-situ stress encountered during the construction of the Muzhailing Tunnel on the Weiyuan–Wudu Expressway. We established a three-dimensional geological model to invert the in-situ stress field using ANSYS based on measured in-situ stress data in the engineering area. Then, we calculated and analyzed the deformation of the surrounding rocks by combining the inverted results with the Hoek deformation prediction formula. The result showed that the in-situ stress field in the engineering area was primarily controlled by faults, with secondary influences from rock strength and topography. In the intense tectonic deformation zone, horizontal principal stress values are generally lower than in the weak structural deformation zone. The relationship between the three principal stresses along the tunnel axis is SH>Sh>SV. The maximum horizontal principal stress in the intense tectonic deformation zone was the highest in the G8 section and the lowest in the G6 and G11 sections. In the weak structural deformation zone, horizontal principal stress gradually increases from the G12 section until it decreases due to reduced burial depth starting from the middle of the G14 section. The maximum horizontal principal stress orientation was generally in the NE direction, and the extruded structural belt between the faults was mostly deflected to the NEE –nearly EW direction. The deformation of the surrounding rocks was affected by rock mass strength and in-situ stress field, with rock mass strength playing a dominant role. The deformation of the surrounding rocks is mainly concentrated in the range of 20 to 80 cm, and the deformation levels are mainly moderate and intense
    corecore