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1.
Environ Sci Technol ; 58(2): 1338-1348, 2024 Jan 16.
Article in English | MEDLINE | ID: mdl-38157442

ABSTRACT

The widespread utilization of tetracyclines (TCs) in agriculture and medicine has led to the borderless spread of tetracycline resistance in humans, animals, and the environment, posing huge risks to both the ecosystem and human society. Changes in the functional group modifications resulted in a higher bacteriostatic efficacy of the new generation of TCs, but their effect on the emergence and evolution of antibiotic resistance genes (ARGs) is not yet known. To this end, four TCs from three generations were chosen to compare their structural effects on influencing the evolution of ARGs in soil microbial communities. The findings revealed that low-generation TCs, such as tetracycline and oxytetracycline, exhibited a greater propensity to stimulate the production and proliferation of ARGs than did high-generation tigecycline. Molecular docking analysis demonstrated that modifications of the D-ring functional group determined the binding capacity of TCs to the substrate-binding pocket of transcriptional regulators and efflux pumps mainly involved in drug resistance. This can be further evidenced by reverse transcription-quantitative polymerase chain reaction quantification and intracellular antibiotic accumulation assessment. This study sheds light on the mechanism of the structural effect of antibiotic-induced ARG production from the perspective of compound-protein binding, therefore providing theoretical support for controlling the dissemination of antibiotic resistance.


Subject(s)
Microbiota , Tetracyclines , Animals , Humans , Tetracyclines/pharmacology , Tetracyclines/analysis , Molecular Docking Simulation , Genes, Bacterial , Anti-Bacterial Agents/pharmacology , Soil/chemistry , Soil Microbiology
2.
Sci Rep ; 13(1): 10785, 2023 07 04.
Article in English | MEDLINE | ID: mdl-37402839

ABSTRACT

Transumbilical single-port laparoscopy is widely used in gynecological surgery. However, it is rarely used in the treatment of deep infiltrating endometriosis due to its own shortcomings and the complex condition of deep infiltrating endometriosis. The study aims to introduce a transumbilical single-port laparoscopic surgery based on retroperitoneal pelvic spaces anatomy, which can complete the operation of deep infiltrating endometriosis more easily. A retrospective analysis of 63 patients with deep infiltrating endometriosis treated by transumbilical single-port laparoscopy using this method was conducted. The operation duration was 120.00 (85.00 ± 170.00) (35-405) min, the estimated blood loss was 68.41 ± 39.35 ml, the postoperative hospital stay was 5.00 (4.00-6.00) days, and the incidence of postoperative complications was 4.76% (3/63). 1 patient was found to have intestinal injury during operation, 1 patient had ureteral injury after operation, and 1 patient had postoperative pelvic infection, with a recurrence rate of 9.52%. The postoperative scar score was 3.00 (3.00-4.00) and the postoperative satisfaction score was 9.00 (8.00-10.00). In summary, this study demonstrates the feasibility of transumbilical single-port laparoscopic surgery for deep infiltrating endometriosis based on retroperitoneal pelvic spaces anatomy. Hysterectomy, adenomyosis resection, etc. are also feasible with this method, boasting more obvious advantages. This method can make transumbilical single-port laparoscopy more widely used in deep infiltrating endometriosis.


Subject(s)
Endometriosis , Laparoscopy , Female , Humans , Retrospective Studies , Endometriosis/surgery , Endometriosis/etiology , Laparoscopy/adverse effects , Laparoscopy/methods , Pelvis/surgery , Hysterectomy/methods , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Postoperative Complications/surgery
3.
Bioresour Technol ; 386: 129495, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37454959

ABSTRACT

Anaerobic reactors often underperform compared to expectations. To identify the key factors, an ecological anaerobic reactor (EAR) with vertical partitions was developed and compared to a physical anaerobic reactor (PAR) as the control. It was observed that EAR achieved a much higher organic loading rate (OLR) compared to PAR (>100 vs 45 kg/m3·d). The different vertical distribution characteristics of anaerobic granular sludge could be ascribed to two vertical distribution patterns dominated in EAR and PAR, i.e., ecological and physical distributions. It was revealed that ecological distribution was formed by the habitat selection, resulting in promoted substrate availability and higher OLR. While physical distribution was mainly affected by hydraulic selection via granule settleability, causing declined substrate availability and lower OLR. Consequently, the promoted ecological distribution and weakened hydraulic selection in EAR contributed to its good performance. Overall, these findings could offer novel concepts for the development of reactors towards high performance.


Subject(s)
Sewage , Waste Disposal, Fluid , Anaerobiosis , Waste Disposal, Fluid/methods , Bioreactors
4.
Bioresour Technol ; 386: 129514, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37473785

ABSTRACT

Calcification is a critical challenge for achieving anaerobic reactors' high-efficiency. However, the aggregation caused by calcification at both granular sludge and reactor levels remain to be fully understood. Herein, this study investigated the characteristics of calcification in an anaerobic reactor (RH) operated with high calcium-containing wastewater for over 200-day. It was found that the COD removal efficiency in RH dropped from 98.00 ± 2.06% to 41.29 ± 3.79%, which was much lower than that of 95.50 ± 1.55% in the control reactor. Morphological analysis revealed that the high influent calcium caused granular sludge aggregation, which would further led to the rapid deterioration in bioavailability, as confirmed by both mass transfer tests and theoretical simulations. Moving forward, statistical analysis showed that the proportion of bioavailability deterioration zones in RH system (61.68%) was similar to the decreased COD removal efficiency (57.87%), proving that bioavailability deterioration was the culprit for the performance decline of anaerobic reactor.


Subject(s)
Sewage , Waste Disposal, Fluid , Anaerobiosis , Biological Availability , Calcium , Bioreactors
5.
Front Immunol ; 14: 1126874, 2023.
Article in English | MEDLINE | ID: mdl-36845110

ABSTRACT

This study aims to investigate the early changes in the immune systems of patients with septic shock. A total of 243 patients with septic shock were included in this study. The patients were classified as survivors (n = 101) or nonsurvivors (n = 142). Clinical laboratories perform tests of the immune system's function. Each indicator was studied alongside healthy controls (n = 20) of the same age and gender as the patients. A comparative analysis of every two groups was conducted. Univariate and multivariate logistic regression analyses were performed to identify mortality risk factors that are independent of one another. In septic shock patients, neutrophil counts, infection biomarkers (C-reactive protein, ferritin, and procalcitonin levels), and cytokines (IL-1ß, IL-2R, IL-6, IL-8, IL-10, and TNF-α) increased significantly. Lymphocyte and their subset counts (T, CD4+ T, CD8+ T, B, and natural killer cell counts), lymphocyte subset functions (the proportions of PMA/ionomycin-stimulated IFN-γ positive cells in CD4+ T cells), immunoglobulin levels (IgA, IgG, and IgM), and complement protein levels (C3 and C4) decreased significantly. Compared to survivors, nonsurvivors had higher levels of cytokines (IL-6, IL-8, and IL-10) but lower levels of IgM, complement C3 and C4, and lymphocyte, CD4+, and CD8+ T cell counts. Low IgM or C3 concentrations and low lymphocyte or CD4+ T cell counts were independent risk factors for mortality. These alterations should be considered in the future development of immunotherapies aimed at treating septic shock.


Subject(s)
Shock, Septic , Humans , Interleukin-10 , Interleukin-6/metabolism , Interleukin-8 , Cytokines , Immune System/metabolism , Immunoglobulin M
6.
Mol Immunol ; 152: 232-239, 2022 12.
Article in English | MEDLINE | ID: mdl-36379131

ABSTRACT

Acute lung injury is a severe complication of sepsis with high mortality in ICU. Increasing evidences have showed that Ibrutinib, a Bruton's Tyrosine kinase inhibitor, plays a critical role in numerous inflammation-related diseases. However, its therapeutic effect and mechanism in sepsis induced acute lung injury remain unclear. In this study, cecal ligation puncture (CLP) was performed on male C57BL/6 J mice to establish a mouse model of sepsis. Ibrutinib (50 mg/kg/d) was administered by gavage 1 day before CLP, once a day, for 3 consecutive days. on the fourth day mice were given one dose of ibrutinib 2 h before CLP induction, and another dose was given 24 h later. Histopathological examination of lung tissues was performed at 72 h. The levels of myeloperoxidase (MPO), interleukin (IL)- 6, TNF-α, IL-1ß and IL-18 in bronchoalveolar lavage fluid (BALF) were determined by ELISA. Western blotting was used to detect the expression of pyroptosis related proteins. The results showed that Ibrutinib treatment significantly improved the prognosis of mice and mitigated the lung histopathological injury and inflammatory response. Moreover, Ibrutinib significantly inhibited the expression of pyroptosis related proteins (NLRP3, Caspase-1, Gasdermin D (GSDMD), IL-1ß and IL-18) in the lung tissues of sepsis mice. In conclusion, our results suggest that Ibrutinib exerted protective effects against lung injury of septic mice and inhibited the activation of pyroptosis in lung tissue, which may be a potential treatment for sepsis induced lung injury.


Subject(s)
Acute Lung Injury , Sepsis , Animals , Mice , Male , Caspase 1 , NLR Family, Pyrin Domain-Containing 3 Protein , Interleukin-18 , Mice, Inbred C57BL , Acute Lung Injury/drug therapy , Acute Lung Injury/complications , Disease Models, Animal , Sepsis/complications , Interleukin-6
7.
Int J Gen Med ; 15: 5499-5512, 2022.
Article in English | MEDLINE | ID: mdl-35698659

ABSTRACT

Purpose: Currently, assessing trauma severity alone in geriatric trauma patients (GTPs) cannot accurately predict the risk of serious adverse outcomes during hospitalization. As an emerging concept in recent years, frailty syndrome is closely related to the poor prognosis of many diseases in elderly patients, including trauma. A logistic model for predicting adverse outcomes in elderly trauma patients during hospitalization was constructed in elderly patients, and the predictive efficacy of the model was verified. Patients and Methods: Trauma patients aged ≥65 years between June 2020 and September 2021 were selected and randomly divided into a training set and validation set at a ratio of 3:1. Mid arm muscle circumference (MAMC) was measured to determine the degree of frailty. LASSO regression was used to screen appropriate variables for the construction of a prognostic model. The logistic regression model was established and presented in the form of a nomogram. Calibration curves and ROC curves were used to verify the performance of the model. Results: A total of 209 patients were enrolled, including 143 (68.4%) males and 66 (31.6%) females, with an average age of 70.8 ± 4.8 years. Ageless Charlson comorbidity index, BT unit, ISS, GCS, MAMC, prealbumin and lactic acid levels were screened by LASSO regression to construct a prognostic model. The AUC of the ROC analysis prediction model was 0.89 (95% CI 0.80-0.97) in the validation set. The results of the Hosmer-Lemeshow test for the validation set were χ2 = 11.23, P = 0.189. Conclusion: The prognostic model of adverse outcomes in GTPs has good accuracy and differentiation, which can improve the prediction results of risk stratification of GTPs during hospitalization by medical staff and provide a new idea for prognostic prediction.

8.
Int J Gen Med ; 15: 4379-4390, 2022.
Article in English | MEDLINE | ID: mdl-35493196

ABSTRACT

Purpose: The Geriatric Trauma Outcome Score (GTOS) has been developed and indicate to be a valid prognostic tool for the prediction of mortality in geriatric trauma patients (GTPs) during hospitalization. However, the predictive value of the GTOS for morbidity is still unclear. We aimed to evaluate the association between GTOS, morbidity and mortality in GTPs. Patients and Methods: We performed a retrospective cohort study between June 1, 2016, and May 31, 2020, and collected data for patients aged 65 years or older. These patients were treated at the Trauma Center of Tongji Hospital, Wuhan, China. Clinical data were retrieved from the trauma registry. The GTOS was calculated with the following formula: age + ISS * 2.5 + 22 (if any packed red blood cells were transfused within 24 hours after admission). The outcomes were mortality, morbidity, length of hospital stay (LOS), and functional outcome at discharge. Results: A total of 485 patients were enrolled: 214 (44.1%) were classified into the low-GTOS group, and 271 (55.9%) were classified into the high-GTOS group. The median (IQR) age was 68 (66-71) years; 361 (74.4%) were male. The most common mechanism of injury was vehicle collision (66.4%), followed by falls <2 m (19.6%). The median (IQR) ISS was 18 (14-22). The median (IQR) GCS was 13 (9-15). A high GTOS was associated with high rates of all-cause mortality (13.3% vs 0.9%, P < 0.001), complications (88.2% vs 31.8%, P < 0.001), unplanned intubation (19.2% vs 1.4%, P < 0.001), and unplanned admissions to the intensive care unit (8.5% vs 0.5%, P < 0.001). In multivariable logistic regression analysis, GTOS was associated with morbidity (OR 1.07, 95% CI, 1.05-1.09, p < 0.001) and mortality (OR 1.04, 95% CI, 1.02-1.06, p < 0.001). Conclusion: The GTOS is an independent predictor of morbidity and mortality in GTPs, and it will help us identify patients at high risk on admission.

9.
J Hazard Mater ; 435: 128889, 2022 08 05.
Article in English | MEDLINE | ID: mdl-35472548

ABSTRACT

Bacterial conjugation is one of the most prominent ways for antibiotic resistance genes (ARGs) transmission in the environment. Interfacial interactions between natural colloidal minerals and bacteria can alter the effective contact of bacteria, thereby affecting ARGs conjugation. Understanding the impact of iron minerals, a core component of colloidal minerals, on ARGs conjugation can help assess and intervene in the risk of ARGs transmission. With three selected iron minerals perturbation experiments, it was found that the conjugative transfer of plasmid that carried kanamycin resistance gene was 1.35 - 3.91-fold promoted by low concentrations of iron minerals (i.e., 5 - 100 mg L-1), but inhibited at high concentrations (i.e., 1000 - 2000 mg L-1) as 0.10 - 0.22-fold. Conjugation occurrence was highly relevant to the number of bacteria adhering per unit mass of mineral, thus switch in the adhesion modes of mineral-bacterial determined whether the conjugate transfer of ARGs was facilitated or inhibited. In addition, a unified model was formularized upon the physicochemical and physiological effects of adhesion on conjugation, and it can be used in estimating the critical inhibitory concentration of different iron minerals on conjugation. Our findings indicate natural colloidal minerals have great potential for applications in preventing the environmental propagation of ARGs through interfacial interactions.


Subject(s)
Anti-Bacterial Agents , Conjugation, Genetic , Anti-Bacterial Agents/pharmacology , Bacteria/genetics , Drug Resistance, Microbial/genetics , Genes, Bacterial , Iron/pharmacology , Minerals/pharmacology
10.
Sensors (Basel) ; 21(24)2021 Dec 14.
Article in English | MEDLINE | ID: mdl-34960445

ABSTRACT

With the widespread application of machine learning methods, the continuous improvement of forecast accuracy has become an important task, which is especially crucial for landslide displacement predictions. This study aimed to propose a novel prediction model to improve accuracy in landslide prediction, based on the combination of multiple new algorithms. The proposed new method includes three parts: data preparation, multi-swarm intelligence (MSI) optimization, and displacement prediction. In the data preparation, the complete ensemble empirical mode decomposition (CEEMD) is adopted to separate the trend and periodic displacements from the observed cumulative landslide displacement. The frequency component and residual component of reconstructed inducing factors that related to landslide movements are also extracted by the CEEMD and t-test, and then picked out with edit distance on real sequence (EDR) as input variables for the support vector regression (SVR) model. MSI optimization algorithms are used to optimize the SVR model in the MSI optimization; thus, six predictions models can be obtained that can be used in the displacement prediction part. Finally, the trend and periodic displacements are predicted by six optimized SVR models, respectively. The trend displacement and periodic displacement with the highest prediction accuracy are added and regarded as the final prediction result. The case study of the Shiliushubao landslide shows that the prediction results match the observed data well with an improvement in the aspect of average relative error, which indicates that the proposed model can predict landslide displacements with high precision, even when the displacements are characterized by stepped curves that under the influence of multiple time-varying factors.

11.
Sensors (Basel) ; 21(2)2021 Jan 06.
Article in English | MEDLINE | ID: mdl-33419075

ABSTRACT

Cyclic wetting and drying treatment is commonly used to accelerate the weakening process of reservoir rock. The weakening is reflected in strength variation and structure variation, while the latter receives less attention. Based on a series of cyclic wetting and drying tests, this study tentatively applied the uniaxial compressive test, computed tomography (CT) test and digital image correlation (DIC) test to investigate the weakening of slate in a reservoir area. Test results show that the weakening is mainly reflected in the reduction of compressive strength, followed by the decrease of ability to resist cracking and elastic deformation. The weakening seems more likely to be caused by structure variation rather than composition change. Two failure modes, e.g., splitting and splitting-tension, are concluded based on the crack paths: the splitting failure mode occurs in the highly weathered samples and the splitting-tension failure mode appears in the low-weathered samples. The transition zones of deformation are inside samples. The nephogram maps quantify the continuous deformation and correspond to the aforementioned structure variation process. This study offers comprehensive methods to the weakening investigation of slate in reservoir area and may provide qualitative reference in the stability evaluation of related slate rock slope.

12.
Sensors (Basel) ; 20(24)2020 Dec 14.
Article in English | MEDLINE | ID: mdl-33327398

ABSTRACT

Landslide displacement monitoring plays a fundamental role in the study of landslide evolution mechanisms, forecasting, risk assessment, prevention, and control. To fill the deficiencies of traditional instrumentation for measuring landslide displacement distributed along lateral direction, a landslide displacement measurement method based on deformation-coupled pipeline trajectory measurement is proposed, and a pipeline trajectory inertial measurement instrument is developed. The developed instrument, primarily comprised of a single shaft gyro, two axis accelerometers, and an external roller encoder, is designed as an axial half strapdown-radial half platform structure combined with a mechanical gravity platform. This structure avoids the singularity of pitch angle and roll angle and can expediently calculate a pipeline trajectory with an Eulerian transformation when obtaining several basic physical variables, e.g., the axial linear velocity, pitch angle, roll angle, and azimuth angle. Additionally, the pipeline trajectory, measured at different times, possesses the ability to reflect the displacement evolution feature of landslides. The results of prototype simulation tests imply a single measurement accuracy of a 12 cm/100 m span and a singly periodic multiple (more than five times) measurement accuracy of a 3 cm/100 m span, which meets medium-precision displacement measurement requirements for a landslide. Additionally, the finished instrument has been successfully applied to the deformation monitoring of the Majiagou I# landslide, which further verifies its feasibility and offers a reference for similar landslides.

13.
Sensors (Basel) ; 20(22)2020 Nov 15.
Article in English | MEDLINE | ID: mdl-33203153

ABSTRACT

Slip zone soil is usually composed of clay or silty clay; in some special geological environments, it contains gravels, which make the properties of the slip zone soil more complex. Unfortunately, in many indoor shear tests, gravels are removed to meet the demands of apparatus size, and the in situ mechanical property of the gravelly slip zone soil is rarely studied. In this study, the shear mechanical property of the gravelly slip zone soil of Huangtupo landslide in the Three Gorges Reservoir area of China was investigated by the in situ shear test. The test results show that the shear deformation process of the gravelly slip zone soil includes an elastic deformation stage, elastic-plastic deformation stage, and plastic deformation stage. Four functions were introduced to express the shear constitutive model of the gravelly slip zone soil, and the asymmetric sigmoid function was demonstrated to be the optimum one to describe the relationship of the shear stress and shear displacement with a correlation coefficient of 0.986. The comparison between the in situ test and indoor direct shear test indicates that gravels increase the strength of the slip zone soil. Therefore, the shear strength parameters of the gravelly slip zone soil obtained by the in situ test are more preferable for evaluating the stability of the landslide and designing the anti-slide structures.

14.
Sensors (Basel) ; 20(17)2020 Aug 27.
Article in English | MEDLINE | ID: mdl-32867248

ABSTRACT

Cyclic wetting and drying processes have been considered as important factors that accelerate the weathering process and have deteriorative effects on rock properties. In the present study, a fully nondestructive and noninvasive testing approach utilizing micro-CT and ultrasonic wave velocity tests was employed to investigate the microstructure of slate under wetting and drying cycles. We studied variations in the physical properties, including the dry weight and the velocities of P- and S-waves versus the number of wetting and drying cycles. The internal microstructural distributions were visualized and quantified by the 3D reconstruction and hybrid image segmentation of CT images. The degree of deterioration caused by wetting and drying cycles was reflected by exponential decreases of physical properties, including dry weight and velocities of the P- and S-waves. Parameters relating to the microfracture diameter, volume, etc. were quantified. The nondestructive and noninvasive testing approach utilizing micro-CT and ultrasonic wave velocity tests has potential for the detection and visualization of the internal microstructure of rock under wetting and drying cycles.

15.
Sensors (Basel) ; 20(15)2020 Jul 31.
Article in English | MEDLINE | ID: mdl-32752029

ABSTRACT

Accurately predicting the surface displacement of the landslide is important and necessary. However, most of the existing research has ignored the frequency component of inducing factors and how it affects the landslide deformation. Therefore, a hybrid displacement prediction model based on time series theory and various intelligent algorithms was proposed in this paper to study the effect of frequency components. Firstly, the monitoring displacement of landslide from the Three Gorges Reservoir area (TGRA) was decomposed into the trend and periodic components by complete ensemble empirical mode decomposition (CEEMD). The trend component can be predicted by the least square method. Then, time series of inducing factors like rainfall and reservoir level was reconstructed into high frequency components and low frequency components with CEEMD and t-test, respectively. The dominant factors were selected by the method of dynamic time warping (DTW) from the frequency components and other common factors (e.g., current monthly rainfall). Finally, the ant colony optimization-based support vector machine regression (ACO-SVR) is utilized for prediction purposes in the TGRA. The results demonstrate that after considering the frequency components of landslide-induced factors, the accuracy of the displacement prediction model based on ACO-SVR is better than that of other models based on SVR and GA-SVR.

16.
Article in English | MEDLINE | ID: mdl-32825026

ABSTRACT

In the process of rapid drawdown of reservoir water level, the seepage force in the slide mass is an important factor for the stability reduction and deformation increment of many landslides in the reservoir areas. It is feasible to improve the stability of seepage-induced landslide by employing a drainage well to reduce or eliminate the water head difference that generates the seepage force. In this paper, the Shuping landslide, a typical seepage-induced landslide in the Three Gorges Reservoir area of China, is taken as an example. A series of numerical simulations were carried out to figure out the seepage field, and the Morgenstein-Price method was adopted to calculate the landslide stability. Then the influence of horizontal location of the drainage well, drainage well depth, drainage mode on the landslide treatment effect, and the applicability of drainage well were analyzed. The results show that: (1) landslide stability increases obviously with the well depth in the slide mass, while the increment of landslide stability with the well depth is limited in the slide bed; (2) the sensitivity of the stability improvement with the depth is greater than that with the horizontal positions of the drainage wells in the slide mass; (3) the drainage well is suggested to be operated when the reservoir water falls rather than operates all the time; and (4) the drainage method is most suitable for landslides with low and medium permeability. These results provide deep insights into the treatment of seepage-induced landslides.


Subject(s)
Landslides , Water Movements , China , Environment , Water
17.
Neural Netw ; 130: 286-296, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32717458

ABSTRACT

Interval prediction is an efficient approach to quantifying the uncertainties associated with landslide evolution. In this paper, a novel method, termed lower upper bound estimation (LUBE), of constructing prediction intervals (PIs) based on neural networks (NNs) is applied and extended to landslide displacement prediction. A random vector functional link network (RVFLN) is adopted as the NN used in the improved LUBE. A hybrid evolutionary algorithm, termed PSOGSA, that combines particle swarm optimization (PSO) and gravitational search algorithm (GSA) is utilized to train LUBE. The loss function of LUBE is redesigned by considering the quality of PI centre, which allows for a more comprehensive evaluation of PIs. The population initialization in the training process of LUBE is implemented by transferring the weights of a series of pre-trained RVFLNs. The performance of the improved LUBE method is validated by considering a comprehensive set of cases using seven benchmark datasets. In addition, a hybrid method that integrates ensemble empirical mode decomposition (EEMD) with the improved LUBE is proposed for the special case of landslide displacement prediction. Six real-world reservoir-induced landslides are considered to validate the capability and merit of the proposed hybrid method.


Subject(s)
Neural Networks, Computer , Support Vector Machine , Algorithms , Forecasting
18.
Sensors (Basel) ; 20(3)2020 Feb 07.
Article in English | MEDLINE | ID: mdl-32046026

ABSTRACT

The loose accumulation CAUSED by landslide, collapse, debris flow, and mine blasting, exerts considerable negative influence to human activities. Besides, it can easily trigger secondary disaster under inner and outer geological conditions. Extraction and measurement of the particle of loose accumulation is of importance for prediction of slope stability and mine blasting. In this paper, the 3D laser scanning is utilized to collect the point clouds of granular materials in physical model (three types of materials) and landslide accumulation in field, respectively. Then, the alpha shapes (AS) and hill climbing-region growing (HC-RG) algorithms are introduced for identifying particles and finding their dimensions (e.g., particle number and radii). Comparison between the recognition results and reality shows that both algorithms can provide a good performance in laboratory physical model, and acceptable results can be obtained when applying two algorithm to field survey. AS algorithm needs less time to process data than HC-GR algorithm; however, the recognition from HC-RG algorithm is more accurate than that by AS algorithm.


Subject(s)
Algorithms , Particle Size , Computer Simulation , Models, Theoretical
19.
Chemosphere ; 237: 124455, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31376694

ABSTRACT

Strains selection for inoculation is the key to the successful construction of a bioaugmentation system, a promising strategy for specific pollutant removal. Pseudomonas aeruginosa SD-1 wild-type (WT) strain exhibited high capacity for biofilm formation but low efficiency for nitrate (NO3-) removal. Meanwhile, quorum sensing deficient strain ΔlasR showed excellent efficiency for NO3- removal but poor capability for colonization in activated sludge. The opposite effect of biofilm formation and NO3- removal exist in WT or ΔlasR, which limits the construction of bioaugmentation system of strain SD-1 and its application. To solve this issue, a mixture of WT and ΔlasR (v/v = 1:1) was used to construct a bioaugmentation system. Compared with the inoculation of WT or ΔlasR alone, the mixed inoculation not only was beneficial for activated sludge development but also for pollutant removal. The indicators for activated sludge including the abundance of P. aeruginosa, the sludge volume index and the average particle size in mixed inoculated reactors were close to those of reactors with single and repeated inoculation of WT. The effluent of chemical oxygen demand (COD) and NO3--N were stable at 3.9-22.6 mg L-1 and 0-5.53 mg L-1 after d 3, respectively. This study presents a detailed case on the ecological tradeoff of colonization and pollutant removal of inoculated strains during bioaugmentation. The results provide information on the appropriate conditions for application of P. aeruginosa SD-1 for livestock wastewater treatment and further enrich our ecological understanding of bioaugmentation.


Subject(s)
Environmental Restoration and Remediation/methods , Livestock/microbiology , Pseudomonas aeruginosa , Wastewater , Water Purification/methods , Animals , Biofilms/growth & development , Nitrates/isolation & purification , Waste Disposal, Fluid/methods , Wastewater/analysis , Water Pollution
20.
Sensors (Basel) ; 19(6)2019 Mar 26.
Article in English | MEDLINE | ID: mdl-30917488

ABSTRACT

Deformation monitoring is a powerful tool to understand the formation mechanism of earth fissure hazards, enabling the engineering and planning efforts to be more effective. To assess the evolution characteristics of the Yangshuli earth fissure hazard more completely, terrestrial laser scanning (TLS), a remote sensing technique which is regarded as one of the most promising surveying technologies in geohazard monitoring, was employed to detect the changes to ground surfaces and buildings in small- and large-scales, respectively. Time-series of high-density point clouds were collected through 5 sequential scans from 2014 to 2017 and then pre-processing was performed to filter the noise data of point clouds. A tiny deformation was observed on both the scarp and the walls, based on the local displacement analysis. The relative height differences between the two sides of the scarp increase slowly from 0.169 m to 0.178 m, while no obvious inclining (the maximum tilt reaches just to 0.0023) happens on the two walls, based on tilt measurement. Meanwhile, global displacement analysis indicates that the overall settlement slowly increases for the ground surface, but the regions in the left side of scarp are characterized by a relatively larger vertical displacement than the right. Furthermore, the comparisons of monitoring results on the same measuring line are discussed in this study and TLS monitoring results have an acceptable consistency with the global positioning system (GPS) measurements. The case study shows that the TLS technique can provide an adequate solution in deformation monitoring of earth fissure hazards, with high effectiveness and applicability.

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