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The multi-scale roughness of a fault interface is responsible for multiple asperities that establish a complex and discrete set of real contacts. Since asperities control the initiation and evolution of the fault slip, it is important to explore the intrinsic relationships between the collective behavior of local asperities and the frictional stability of the global fault system. However, such a mechanism is still elusive due to the difficulty of imaging an exhaustive spatiotemporal variability of a fault interface at depth, and the limited computational efficiency of the numerical models with heterogeneity over a large time and space domain. Here we propose a novel analog experimental approach, which allows us to capture the temporal evolution of the slip of each asperity on a faulting interface. We link the collective behavior of asperities with the mechanical response of the whole fault interface. We find that many destabilizing events at the local asperity scale occurred in the frictional strengthening stage which is conventionally considered as the stable regime of a fault. We compute the interseismic coupling to evaluate the slipping behaviors of asperities during the fault strengthening stage. Based on a high-resolution topographical map of the fault surface, we evidence that the interseismic coupling is not only dependent on the normal load and the peak height of asperity but also can be affected by the interactions between asperities through the embedding soft matrix. Furthermore, we quantify the spatiotemporal interactions of asperities as slip episodes. The significant characteristics and scaling-laws observed in natural earthquakes, such as the magnitude-frequency distribution and the moment-duration scaling, are reproduced through the catalog of slip episodes to demonstrate the effective upscaling. We give geophysical implications for the physics and mechanics of natural faults and discuss some limitations of our experimental setup.

Objective The aim of the study was to identify risk factors associated with the failure of noninvasive ventilation (NIV) in patients with severe acute pancreatitis (SAP). Methods Patients who received NIV as a first-line therapy because of acute respiratory failure caused by SAP were enrolled. Results A total of 133 patients were enrolled. Of the patients, 32 (24%) experienced NIV failure. Male sex (odds ratio [OR], 4.25; 95% confidence interval [CI], 1.48-12.22), older age (OR, 1.04; 95% CI, 1.01-1.08), a higher Acute Physiology and Chronic Health Evaluation II score (OR, 1.18; 95% CI, 1.03-1.36), and a procalcitonin level greater than 3.8 ng/mL (OR, 6.28; 95% CI, 2.04-19.31) were independently associated with NIV failure. The receiver operating characteristic curves for predicting NIV failure were 0.67, 0.72, and 0.76 tested by age, procalcitonin, and Acute Physiology and Chronic Health Evaluation II score, respectively. From initiation to 24 hours, the patients in the NIV failure group had a higher proportion of Glasgow Coma Scale scores of 14 or less, a higher proportion of pH ≤7.35, and higher respiratory rates than ones in the successful NIV group. Conclusions One of 4 SAP patients experience NIV failure. Age, sex, disease severity, level of inflammation, and vital signs can be used to predict NIV failure.

The transition between seismic slip and aseismic creep of faults in the Earth crust suggests a strong time-dependent mechanism for the underlying physics and corresponding mechanical response of fault slip. Asperities establish the real contact on the slipping interface of a fault and serve as stress concentrators that control the initiation of earthquakes. Investigating the interactions between individual asperities and how the global stability of a fault is controlled by the collective effects of their local behaviors are essential for understanding the intrinsic relationships between earthquake swarms and faulting. Here we design a novel direct-shear experimental setup, which allows a thick PMMA (poly-methyl-methacrylate) plate to slide slowly on a customized surface, on which asperities are modeled by spherical PMMA beads and embedded in a softer polymer base, for analogizing tectonic faults. We perform various experiments by applying multiple normal loads and loading rates, with a high-resolution camera employed to capture the detailed activities of asperities. We demonstrate the global stability of a fault could be described by the synthesized behaviors of local asperities. We also prove, for the same asperity, it can experience different slip modes at different time periods. We generate a catalog of fault slip events defined by the slipping velocity of each asperity derived from the image correlation technology, and then we determine slip episodes based on time and space successively. Furthermore, we investigate the distributions of various parameters of the determined slip episodes, including the number of slipping asperities, as well as the duration, mean slip displacement, and moment of slip episodes. We explore the spatiotemporal variations of b-value within one analog seismic cycle and under different normal loads and loading rates. We link the findings at local scales with the bulk mechanical response of the whole fault. Our results bring new insights into the physics and mechanics of seismic and aseismic faulting.

Rationale: The etiology of acute respiratory distress syndrome (ARDS) may play an important role in the failure of noninvasive ventilation (NIV). Objectives: To explore the association between ARDS...

The localization of microseismic sources/acoustic emission in the rockmass structure can provide the basis for determining the potential areas of rockmass instability and rockburst in the underground mining. As the construction environment in deep mining is complex, the abnormal arrivals with different scales of errors may be recorded by the monitoring sensors, which can lead to large errors between the located results and the authentic coordinates. In addition, the average premeasured P-wave velocity through blasting tests (blasts) is widely used in the current localization methods, which are unsuitable for the mining environment with dynamic change of wave velocity in multi-level and multi-stope. To eliminate the effects of abnormal arrivals, the analytical localization method is used to remove abnormal arrivals since it has a stable solution with the high precision when the input data are accurate. To weaken errors induced by the dynamic wave velocity, the iterative solution without the need of premeasured P-wave velocity is used to improve the locating accuracy since it can optimize results using the advantage of multiple sensors. Therefore, a collaborative localization method using analytical and iterative solutions (CLMAI) was proposed, which combined with the arrivals of multi-sensor and inversion of the real-time average wave velocity, to seek the optimal locating results. Firstly, the analytical solutions using 6 sensors in unknown velocity system were resolved. The method to remove abnormal arrivals is developed by solving the logistic probability density function for the analytical solutions of different sensors combinations. Then, the iterative localization method based on the time differences was used to locate source coordinates with clear arrivals. Finally, the CLMAI is verified through locating coordinates of blasts and microseismic events (events) in Kaiyang phosphorous mine. Results show that the CLMAI can not only filter the abnormal arrivals by making use of the characteristic of analytical solutions, but also use the iterative method without premeasured average velocity to improve the locating accuracy significantly. The proposed method is a beneficial complement for the current iterative methods using premeasured velocity, which is applicable to microseismic sources localization under complex abnormal arrivals in the rockmass structure of dynamic underground mining.

Background: The failure rate of noninvasive ventilation (NIV) remains high in patients with acute respiratory distress syndrome (ARDS). The etiology of ARDS may play an important role in NIV failure.Methods: A multicenter prospective observational study was performed in 17 ICUs in China from September 2017 to December 2019. ARDS patients who used NIV as a first-line therapy were enrolled. The etiology of ARDS was recorded at study entry. Results: A total of 306 patients were enrolled. Of the patients, 146 were classified as having pulmonary ARDS (ARDSp) and 160 were classified as having extrapulmonary ARDS (ARDSexp). NIV improved PaO2/FiO2 from initiation to 24 h of NIV in both groups. However, it improved more slowly in patients with ARDSp than in those with ARDSexp (interaction effect: p < 0.01). ARDSp patients experienced more NIV failure (55% vs. 28%; p < 0.01) and higher 28-day mortality (47% vs. 14%; p < 0.01). The multivariate Cox regression also showed that ARDSp was independently associated with NIV failure (hazard ratio [HR] = 2.81, 95% confidence interval [CI]: 1.89-4.18) and 28-day mortality (HR = 7.49, 95% CI: 4.32-13.01). After propensity matching, 62 patients remained in each group. The baseline data were comparable between the two groups. ARDSp was still independently associated with NIV failure and 28-day mortality (HR = 2.62, 95%CI: 1.49-4.61; and 5.70, 2.59-12.55, respectively). Sensitivity analysis also confirmed these results. Conclusions: Among ARDS patients who used NIV as a first-line therapy, ARDSp was associated with slower improvement in oxygenation, more NIV failure, and higher 28-day mortality than ARDSexp.

Faults are common geological structures distributed at various depths within the Earth with different behaviors: from seismic to aseismic. The frictional stability of faults is linked to the properties of asperities that make the contact between fault surfaces. Investigating the interaction between asperities and its link with the frictional stability of faults aims at a better understanding of the intrinsic relationships between the observations of earthquake swarms and the slow local aseismic transient. Here we propose an experimental approach, which allows a customized interface sliding slowly under a well-controlled normal load, to study this problem. This interface consists of asperities modeled by poly-methyl-methacrylate (PMMA) balls in a softer, polymer base representing the parts of the fault that are easily deformed, facing a transparent flat PMMA plate. We employ a high-resolution camera for in-situ optical monitoring of the local deformation of the interface while loaded. We also attach acoustic sensors to capture the dynamics events attesting to local dynamic ruptures. We connect our observations with a mechanical model derived from a high-precision topography of the customized interface. We investigate the effects of various internal parameters of natural fault systems, including the density of asperities, their rigidity or the contrast of rigidity compared to the base, on the evolution of the frictional stability under variable normal load and of the behavior of the population of asperities at the transition between seismic and aseismic slip. Our results, bring new observations on the mechanics of swarm and fault transient.

Soil enzymes are involved in the process of mineralization of soil organic matters. The close-to-nature transformation (CNT) of plantations changes the soil enzyme activities by changing the composition of stand vegetation, which in turn affects the change process of soil organic carbon. We therefore selected two typical coniferous plantations in southwest China, Pinus massoniana and Cunninghamia lanceolate, to explore the effects of CNT on soil enzyme activities and soil organic carbon, and the relationship between them is explored through comparative study. Compared with control stands (CCK and PCK), CNT enhanced soil organic carbon; the content of water-soluble organic carbon in the 0–10 cm soil layer of the transformed C. lanceolata plantations (CCN) is 81.29% higher than those in the control stands (p < 0.05); the contents of particulate organic carbon and water-soluble organic carbon in the 10–30 cm soil layer are 95.42% and 48.68% higher than those in the control stands (p < 0.05), respectively; after the CNT, the protease, urease, and acid phosphatase in C. lanceolata plantations were higher than control stands, while protease and catalase in P. massoniana plantations were higher than control stands. Correlation analysis showed that catalase and protease were more closely related to organic carbon components than other organic enzymes; redundancy analysis (RDA) results show that pH and total nitrogen are key factors that cause changes in carbon fractions after the CNT. In general, CNT enhanced soil organic carbon in coniferous plantations, which was more conducive to soil organic carbon accumulation but had a negative effect on soil organic carbon stability to a certain extent. Therefore, the effect of tree species configuration on soil carbon stability components should be considered in the forest management practice.

Background The use of high-flow nasal cannula (HFNC) and noninvasive ventilation (NIV) in patients with COVID-19 is debated. Methods This study was performed in four hospitals of China from January to March 2020. We retrospectively enrolled 23 and 13 COVID-19 patients who used HFNC and NIV as first-line therapy, respectively. Results Among the 23 patients who used HFNC as first-line therapy, 10 experienced HFNC failure and used NIV as rescue therapy. Among the 13 patients who used NIV as first-line therapy, one (8%) used HFNC as rescue therapy due to NIV intolerance. The duration of HFNC + NIV (median 7.1, IQR: 3.5–12.2 vs. 7.3, IQR: 5.3–10.0 days), intubation rate (17% vs. 15%) and mortality (4% vs. 8%) did not differ between patients who used HFNC and NIV as first-line therapy. In total cohorts, 6 (17%) patients received intubation. Time from initiation of HFNC or NIV to intubation was 8.4 days (IQR: 4.4–18.5). And the time from initiation of HFNC or NIV to termination in patients without intubation was 7.1 days (IQR: 3.9–10.3). Among all the patients, C-reactive protein was independently associated with intubation (OR = 1.04, 95% CI: 1.01–1.07). In addition, no medical staff got nosocomial infection who participated in HFNC and NIV management. Conclusions In critically ill patients with COVID-19 who used HFNC and NIV as first-line therapy, the duration of HFNC + NIV, intubation rate and mortality did not differ between two groups. And no medical staff got nosocomial infection during this study., Highlights • The duration of HFNC + NIV, intubation rate and mortality did not differ between patients who used HFNC and NIV as first-line therapy. • C-reactive protein was independently associated with intubation among the patients who used HFNC or NIV as first-line therapy. • No medical staff got nosocomial infection during the management of COVID-19 patients who used HFNC and NIV.

Background The outbreak of a novel coronavirus (2019-nCoV)-infected pneumonia (NCIP) is currently ongoing in China. Most of the critically ill patients received high-flow nasal cannula (HFNC) oxygen therapy. However, the experience of HFNC in this population is lacking. Methods We retrospectively screened 318 confirmed patients with NCIP in two hospitals of Chongqing, China, from January 1st to March 4th, 2020. Among them, 27 (8.4%) patients experienced severe acute respiratory failure including 17 patients (63%) treated with HFNC as first-line therapy, 9 patients (33%) treated with noninvasive ventilation (NIV) and one patient (4%) treated with invasive ventilation. HFNC failure was defined by the need of NIV or intubation as rescue therapy. Results Of the 17 HFNC patients, 7 (41%) experienced HFNC failure. The HFNC failure rate was 0% (0/6) in patients with PaO2/FiO2 > 200 mm Hg vs. 63% (7/11) in those with PaO2/FiO2 ≤ 200 mm Hg (p = 0.04). Compared with baseline data, the respiratory rate significantly decreased after 1–2 h of HFNC in successful group [median 26 (IQR: 25–29) vs. 23 (22–25), p = 0.03]. However, it did not in the unsuccessful group. After initiation of NIV as rescue therapy among the 7 patients with HFNC failure, PaO2/FiO2 significantly improved after 1–2 h of NIV [median 172 (150–208) mmHg vs. 114 (IQR: 79–130) under HFNC, p = 0.04]. However, two out of seven (29%) patients with NIV as rescue therapy ultimately received intubation. Among the 27 patients with severe acute respiratory failure, four patients were eventually intubated (15%). Conclusions Our study indicated that HFNC was the most common ventilation support for patients with NCIP. Patients with lower PaO2/FiO2 were more likely to experience HFNC failure.

Background The outbreak of a novel coronavirus (2019-nCoV)–infected pneumonia (NCIP) is currently ongoing in China. Most of the critically ill patients received high flow nasal cannula (HFNC). However, the experience of HFNC in this population is lacking. Methods We retrospectively collected the NCIP patients who received HFNC in two hospital of Chongqing, China from January 1st to February 18th, 2020. The clinical characteristics were collected. Patients who required upgrading to noninvasive ventilation (NIV) were defined as HFNC failure. Results We enrolled 17 patients in this study. Of them, 7 patients (41%) experienced HFNC failure (6 required upgrading to NIV, and one to NIV and further to intubation). The HFNC failure rate was 0% (0/6), 57% (4/7) and 75% (3/4) (p =0.03 between 3 groups) in patients with PaO2/FiO2 >200, 150-200, and

Since phosphorus is indispensable for the agricultural production, the demand for the phosphate rock is increasing with the agricultural development. For the sustainable development of phosphorus resources, the environmental pollution problem caused by the mining of phosphate rock should be solved efficiently. The cleaner production of phosphorus mines is exactly the basis and method for the sustainable development. Focusing on the environmental characteristics and main mining processes of phosphorus mines, 31 evaluation indexes were selected from 6 aspects including the management level, environmental protection level, mining technique, mining economic indicators, comprehensive utilization level of waste, and processed environmental level, to establish the comprehensive evaluation system for the cleaner production of phosphorus mines. The 5 qualitative evaluation indexes were quantified according to the classification criteria. The 26 quantitative evaluation indexes were determined through the measurement values. The single index measurement values were solved through the semi-trapezoid (ST) and semi-ridge (SR) membership functions. The weights of evaluation indexes were determined based on the theories of uncertainty measurement evaluation (UME) and analytic hierarchy process (AHP). The evaluation vectors were evaluated by applying the credible degree recognition criterion (CDRC) and the maximum membership principle (TMMP). A total of 8 coupled methods including ST-UME-CDRC, ST-UME-TMMP, ST-AHP-CDRC, ST-AHP-TMMP, SR-UME-CDRC, SR-UME-TMMP, SR-AHP-CDRC, and SR-AHP-TMMP were developed based on the combination of ST and SR membership functions, UME and AHP theories, as well as recognition criteria CDRC and TMMP. The cleaner production grades of two phosphorous mines in China were evaluated using these developed coupling methods. The future suggestions and approaches were given to improve cleaner production grades. Results show that ST-UME-CDRC method is the most reasonable among 8 coupled methods, which can not only evaluate the cleaner production grades of phosphorous mines, but also can provide a useful guidance to the sustainable development of phosphorous mines.

Background Mixed forests are believed to enhance ecosystem functioning and sustainability due to complementary resource use, environmental benefits and improved soil properties. The facilitation between different species may induce overyielding. Meanwhile, the species-specific fine root foraging strategies and tradeoffs would determine the structure and dynamics of plant communities. Here the aim was to investigate the admixing effects of fine-root biomass, vertical distribution and morphology in Pinus massoniana–Cinnamomum camphora mixed plantations and corresponding monocultures at 10-, 24- and 45-year old stands. Results The fine root biomass in the Pinus–Cinnamomum mixed forest exerted a certain degree of overyielding effect. These positive admixing effects, however, did not enhance with forest stand development. The overall relative yield total ranged from 1.83 and 1.51 to 1.33 in 10-, 24- and 45-year-old stand, respectively. The overyielding was mainly attributed to the over-performance of late successional species, Cinnamomum, in mixed stands. The vertical fine root biomass distribution model showed fine roots of pioneer species, Pinus, shifted to the superficial layer when mixed with Cinnamomum. Furthermore, the specific root length (SRL) of Pinus was significantly higher in Pinus–Cinnamomum mixed stands than that in monocultures, and the magnitude of differences increased over time. However, the vertical fine-root distribution and SRL for Cinnamomum did not show significant differences between monoculture and mixtures. Conclusions Our results indicated that the magnitude of fine root overyielding in mixed forests showed a high degree of consistency with the total amount of fine root biomass itself, suggesting the overyielding effects in mixed forests were correlated with the degree of belowground interaction and competition degree involved. The late successional species, Cinnamomum, invested more carbon to belowground by increasing the fine root biomass in mixtures. While the pioneer species, Pinus, adapted to the presence of the species Cinnamomum by modification of vertical distribution and root morphological plasticity in the mixtures. These species-specific fine root foraging strategies might imply the differences of forest growth strategies of co-occurring species and contribute to the success and failure of particular species during the succession over time.

The localization for sources in the heterogeneous and complex media is of vital significance, which can be applied to monitor the invisible cracks and determine the potential damage areas of buildings with safety hazards. Based on the localization function with the model of arrival time difference (TD), a multi-step localization method (MLM) without premeasured velocity for heterogeneous and complex propagation media was proposed. The velocity interval used for localization was narrowed and optimized continuously through the multi-step localization, where the optimal velocity interval was determined when the velocity differences were less than the threshold. Then, the optimal localization results with higher accuracy corresponding to this velocity interval can be obtained with the TD algorithm. A source locating test was performed at a building of masonry structure. In addition, the locating accuracy was compared and discussed between the optimized MLM, the one-step method without premeasured velocity, and the traditional method with different premeasured velocity values. Results show that MLM is obviously superior to both the one-step method and the traditional method. The developed MLM can not only eliminate the errors caused by premeasured velocity, but also can improve the locating accuracy in the heterogeneous and complex media, which is an efficient and effective method for engineering applications.

The accuracy of localization methods based on the arrival time difference is usually affected by the iterative algorithm, the initial value, and the pre-measured wave velocity. The analytical solutions are non-unique because of the square root operations in the calculating process for source coordinates. To solve these significant problems, the nonlinear equations were simplified to the linear equations. An analytical localization method without the pre-measured velocity or the square root operations was developed. The explicit formulas for analytical solutions were resolved for the six sensors network. The source coordinates can be solved for real time by substituting the arrival times and coordinates of sensors. Focusing on the practical engineering where the number of sensors is greater than six, the comprehensive analytical solutions were proposed on account of sensor networks, which formed through the combination of different sensors, and the logistic probability density function. The blasting tests in two mines verified its effectiveness and accuracy. Results show that the locating accuracy of three dimensional comprehensive analytical solutions is superior to the traditional methods. The assumed examples proved that the proposed method performs well under different scales of arrival time errors. This proposed method highlights four advantages: without iterative algorithm, without pre-measured velocity, without initial value, and without square root operations.

The tailings dam, a necessary facility to maintain the normal operation of mining enterprises, is a hazard source of human-caused debris flow with high potential energy. The real-time pre-alarm for the instability of tailings dam is vital to ensure the normal mining and safety of human lives and properties. Based on the Internet of Things and wireless networks, the multiple and the key information system of tailings dam is constructed using the sensor data, which include the stability indexes like phreatic line, reservoir water level, internal and external deformation of the tailings dam. The cloud platform is applied to predict the future state of the phreatic line based on real-time monitoring data, where the equation of phreatic line can be obtained. The numerical simulation model is established by considering the predicted equation of phreatic line, limit equilibrium state parameters, reservoir water level, and rainfall. Then, the safety factor, random reliability, and interval non-probabilistic reliability can be solved out through the cloud platform. Combined with the trend of real-time monitoring deformation, as well as calculated dynamic safety factor, random reliability, and interval non-probabilistic reliability, the stable or dangerous warning signals of tailings dam can be obtained by the remote real-time pre-alarm system. The main solved method for the key parameters and pre-alarm process are presented through a case study. It is proved that the pre-alarm system is an efficient and real-time platform for the tailings dam stability with the integration and mutual validation of key information.

Background To investigate the feasibility of combination of ultrasonic elastography (UE) and Ki-67 index as a novel predictive modality for the prognosis of clinic stage Ⅲ breast cancer. Methods Of 112 patients, Multi-parameter of UE were obtained after analyzing elastograms of 112 lesions which were recorded classification of Ki-67 by histopathologic diagnosis. Multivariate Survival analysis was performed by using multivariate Cox model. The nomograms was established to predict the probability of clinic stage Ⅲ breast cancer according to the selected independently significant variables in the multivariate Cox model. The model was internally validated using Harrell’s concordance index. Results ⅢC had significant difference in all ultrasonic elastography (UE) parameters (P < 0.05) and were statistically different from ⅢA and ⅢB (P < 0.01). The Cox model was RR (t)= Exp(1.104* X1+0.901*X4+0.972*X5) (X1: classification of Ki-67, X4: classification of strain ratio, X5: classification of Young's modulus). The nomogram showed that Ki-67 had the greatest influence on survival prediction, followed by Young's modulus and strain ratio. Internal validation revealed a concordance index of 0.76. Conclusions Our study explored a novel modality in predicting the prognosis of clinic stage Ⅲ breast cancer combining a tumor marker with breast UE imaging. A nomogram was developed to prove that the model was helpful to estimate the 5-year survival of the patients.

To achieve an accurate real-time analysis for the classification of Electrocardiogram (ECG) signals in Wireless Body Area Network (WBAN) has been a critical problem. Hence we propose an automatic classification method of ECG signals based on Convolutional Neural Network (CNN) and Long-Short Term Memory Network (LSTM). The CNN layers are mainly responsible to extract local temporal features and the LSTM layer is mainly responsible to encode the whole temporal history. It can automatically classify the four ECG signals in MIT-BIH Arrhythmia Database. The accuracy, sensitivity and specificity of the classification were 99.86%, 99.86% and 99.96% respectively. For 5289s long ECG beat signals, the above classification effect takes only 4.46s time. In addition, the model has the best classification effect for five types of ECG signals under the AAMI standard. The accuracy, sensitivity and specificity are 99.12%, 99.15% and 99.84%, the classification time is only 0.81s for 756s length ECG signals.

Supplemental material, Reviewer_1_v.2 for Noninvasive ventilation failure in patients with hypoxemic respiratory failure: the role of sepsis and septic shock by Jun Duan, Lijuan Chen, Guopeng Liang, Weiwei Shu, Liucun Li, Ke Wang, Shengyu Wang, Xiaoyi Liu, Chunfeng He, Dehua He, Qimin Chen, Bilin Wei, Baixu Chen, Yuzhen Shu, Yao Tian, Liping Fan, Xiaoli Han, Rui Zhang, Xiangmei Yang, Yan Peng, Dong Wan, Xiaoying Chen, Lin Ye, Shijing Tian, Qiong Huang, Lei Jiang, Linfu Bai and Lintong Zhou in Therapeutic Advances in Respiratory Disease

With the effects of high geostress and intensive dynamic disturbances in deep mining, the stability and safety of tunnels are seriously affected. The optimization for U-shaped steel support is of vital significance and can solve the problems of cost reduction and tunnel instability. Based on the perturbation equation, a coupled formula for U-shaped steel and the surrounding rock mass was proposed to evaluate the practical stability of a U-shaped steel support. Through a numerical simulation method, the characteristics of U-shaped steel support can be obtained under coupled static-dynamic loading. Furthermore, the field test was carried out and compared with the numerical simulation, which was discussed. The results show that there will be a stress concentration when the contact area is small. In addition, the concentrated stress will release with the increase in contact area. With the increase in the lateral stress coefficient, the deformation exhibits a downward trend under static loading, indicating that the lateral stress is the dominant force driving the deep geostress activity. The support requirement of this section of surrounding rock can be satisfied by a U-shaped steel group with 1.5 m spacing under dynamic disturbance.

Supplemental material, Author_response_1 for Noninvasive ventilation failure in patients with hypoxemic respiratory failure: the role of sepsis and septic shock by Jun Duan, Lijuan Chen, Guopeng Liang, Weiwei Shu, Liucun Li, Ke Wang, Shengyu Wang, Xiaoyi Liu, Chunfeng He, Dehua He, Qimin Chen, Bilin Wei, Baixu Chen, Yuzhen Shu, Yao Tian, Liping Fan, Xiaoli Han, Rui Zhang, Xiangmei Yang, Yan Peng, Dong Wan, Xiaoying Chen, Lin Ye, Shijing Tian, Qiong Huang, Lei Jiang, Linfu Bai and Lintong Zhou in Therapeutic Advances in Respiratory Disease

The purpose of this review is to discuss the development of the methods in microseismic/acoustic emission (AE) source localization and detail the principles of the mainly developed methods. The important applications of the microseismic/AE in engineering practice and the history of the source localization (from the initial Geiger method of localization to the later double-difference method) are introduced briefly in the beginning of the review. The factors that influence the accuracy of source locating are discussed in Section 2 to provide references on how to improve the accuracy of the localization methods. Then, the main localization methods in the history of the source and AE research have been classified into four parts (i.e., the localization methods for single event, the joint inversion methods, the relative localization methods, and the localization methods in spatial domain); each part is extended and systematically reviewed, respectively, from Sections 3 to 6, where the merit and demerit of the methods are discussed. Finally, a brief summary and some aspects of prospective research are presented.

Induced seismicity associated with mining is becoming an increasingly important issue worldwide, and it poses a hazard to the exposed population and structures. In this work, the seismic sequence is analyzed with the aim of detecting changes in statistical parameters describing the seismic event occurrence before the main shocks, to be used for monitoring the sequence evolution. Temporal and spatial characteristics of seismic sequence before the large magnitude seismic events (MW > 1) in mines are used to investigate the precursor of large magnitude. The statistical results of 25 from 27 large magnitude seismic events implicate the following characteristics of precursor seismicity before the occurrence of the large magnitude seismic event of the sequence: Cumulative Benioff strain increases continuously. The Hurst exponent for the foreshocks is greater than 0.5. There is initially an increase in b value then a decrease. Three cases related to the statistical precursor are presented and discussed in the paper. The observed temporal and spatial variations of three selected indexes including b value, Hurst exponent, and cumulative Benioff strain support the hypothesis that three indexes have significant potential of statistical precursor.

Background Aerosol delivery via mechanical ventilation has been reported to vary significantly among different intensive care units (ICU). The optimal technique for using each aerosol generator may need to be updated with the available evidence. Methods A 2-week prospective multicenter observational cohort study was implemented to record aerosol delivery for mechanically ventilated adult patients in Chinese ICUs. Our data included the type of aerosol device and its placement, ventilator type, humidification, and aerosolized medication administered. A guide for the optimal technique for aerosol delivery during mechanical ventilation was summarized after a thorough literature review. Results A total of 160 patients (105 males) from 28 ICUs were enrolled, of whom 125 (78.1%) received aerosol therapy via invasive ventilation. Among these 125 patients, 53 received ventilator-integrated jet nebulizer, with 64% (34/53) of them placed the nebulizer close to Y piece in the inspiratory limb. Further, 56 patients used continuous nebulizers, with 84% (47/56) of them placed the nebulizer close to the Y piece in the inspiratory limb. Of the 35 patients who received aerosol therapy via noninvasive ventilation, 30 received single limb ventilators and continuous nebulizers, with 70% (21/30) of them placed between the mask and exhalation port. Only 36% (58/160) of the patients received aerosol treatments consistent with optimal practice. Conclusions Aerosol delivery via mechanical ventilation varied between ICUs, and only 36% of the patients received aerosol treatments consistent with optimal practice. ICU clinicians should be educated on the best practices for aerosol therapy, and quality improvement projects aim to improve the quality and outcome of patients with the optimal technique for aerosol delivery during mechanical ventilation are warranted.

Double negative (DNG) metamaterials, which have both negative permittivity and negative permeability, have attracted intensive interest in the last few years for their exotic properties, such as negative refraction, reversed Doppler effect, reversed Vavilov-Cerenkov effect, and the possibility of making perfect lens. Theoretical investigations and practical experiments are being well undergone by many research groups over the world. Applications are found in RF circuit design, antenna size reduction, resonance devices, etc. As one of the most important building blocks, transmission lines have intensive applications in RF and microwave engineering, such as couplers, phase shifters, filters, and leaky wave antennas. By replacing the conventional dielectric materials with DNG medium, we found numerous interesting properties. The complete mode spectrum and dispersive behavior of DNG medium are different from their DPS counterparts. Complex surface modes are found to be existing in a grounded DNGmedium slab. When applying DNGmedium to dipole radiation, both horizontal electric dipole (HED) and horizontal magnetic dipole (HMD) exhibits greatly enhanced radiation pattern due to the slow attenuation of the complex modes on the interface. Microstrip line with DNG is also investigated. It has large attenuation in low frequency band which implies that it is a good candidate for leaky antenna. At higher frequency, the attenuation drops to zero and the propagation constant bifurcates. The method of moment is one of the most successful and efficient approaches in solving integral equations. However, the internal resonance problem of integral equations has plagued solutions of integral equations. A well known example is the internal resonance existing in both electric field integral equation (EFIE) and magnetic field integral equation (MFIE) for PEC scatterers or penetrable scatterers. xviii In the second part of my presentation, we will introduce the concept of original resonance and model resonance, followed by numerical matrix resonance and right-hand-side (RHS) resonance. We will thoroughly study their subtle differences and give numerical examples. The errors in electric current and scattered field near the resonances are studied for both EFIE and MFIE in solving for scattering solution from a 2D circular cylinder.

Breast cancer causes great threats to public health worldwide. The aim of this study was to investigate the correlation between Ki-67 expression and the hemodynamics of contrast-enhanced ultrasound (CEUS) in patients with infiltrative ductal carcinoma (IDC). CEUS was performed on 109 masses in 85 IDC cases before resection. Based on the immunohistochemical staining on the antigen Ki-67, the masses were divided into negative group, weakly positive group, positive group, and strong-positive group. Significant statistical differences were noticed in time to peak, arrive intensity, and peak intensity in the positive groups compared with the negative group. Compared with the positive groups, the negative group showed significant statistical differences in arrive intensity and peak intensity. The antigen Ki-67 was positively correlated with arrived intensity, intensity changes, and rising curve's slope. In contrast, it was negatively correlated with arrived time, time to peak, and continuous time. The hemodynamic parameters of CEUS were correlated with the expression of antigen Ki-67. On this basis, Ki-67 is an effective supplement to the diagnosis of IDC.

The accidents caused by underground goafs are frequent and destructive due to irregular geometric shapes and complex spatial distributions, which caused severe damage to the environment and public health. Based on the theories of uncertainty measurement evaluation (WME) and analytic hierarchy process (AHP), the comprehensive risk evaluation of underground goafs was carried out using multiple indexes. Considering the hydrogeological conditions, mining status, and engineering parameters of underground goafs, the evaluation index system was established to evaluate the risk degrees considering quantified uncertain factors. The single index measurement values were solved by the semiridge measurement function. The weights for evaluation vectors were calculated through the entropy theory and AHP. Finally, the risk level was evaluated according to the credible degree recognition criterion (CDRC) and the maximum membership principle. The risk levels of 37 underground goafs in Dabaoshan mine were evaluated using 4 coupled methods. The order for underground goafs risk degrees was ranked and classified on account of the uncertainty important degree. According to the ranked order, the reasonability of 4 coupled methods was evaluated quantitatively. Results show that the UME-CDRC can be applied in the practical engineering, which provides an efficient guidance to both reduce the accident risk and improve the mining environment.

Background: Sepsis and septic shock are common in noninvasive ventilation (NIV) patients. However, studies on the association between sepsis and NIV failure are lacking. Methods: A prospective multi-center observational study was performed in 16 Chinese intensive care units (ICUs). Patients who used NIV due to hypoxemic respiratory failure were enrolled. Sepsis and septic shock were diagnosed according to the guideline of sepsis-3. Results: A total of 519 patients were enrolled. Sepsis developed in 365 patients (70%) and septic shock developed in 79 patients (15%). However, 75 patients (14%) had no sepsis. NIV failure was 23%, 38%, and 61% in patients, with no sepsis, sepsis, and septic shock, respectively. Multivariate analysis found that sepsis [odds ratio (OR) = 1.95, 95% confidence interval (CI): 1.06–3.61] and septic shock (OR = 2.47, 95% CI: 1.12–5.45) were independently associated with NIV failure. In sepsis and septic shock population, the NIV failure was 13%, 31%, 37%, 53%, and 67% in patients with sequential organ failure assessment (SOFA) scores of ⩽2, 3–4, 5–6, 7–8, and ⩾9, respectively. Patients with nonpulmonary induced sepsis had similar NIV failure rate compared with those with pulmonary induced sepsis, but had higher proportion of septic shock (37% versus 10%, p ⩽ 0.01) and lower ICU mortality (10% versus 22%, p ⩽ 0.01). Conclusions: Sepsis was associated with NIV failure in patients with hypoxemic respiratory failure, and the association was stronger in septic shock patients. NIV failure increased with the increase of organ dysfunction caused by sepsis. The reviews of this paper are available via the supplemental material section.