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Background: Road traffic crashes related (RTCR) chest traumas remain important global public health challenge. The impact of boosting market of automobile vehicles in China during last decade on thoracic injury needs to be defined. This study aimed to review and analyze the demographic and clinical characteristics of RTCR thoracic injuries in China.Methods: Clinical records of patients with thoracic trauma admitted to thoracic surgery department between January 2003 and June 2020 were retrospectively retrieved and reviewed. Patients' profiles and clinical characteristics were comparatively analyzed between road traffic crashes caused injury and other injury mechanisms, and in RTCR chest trauma patients before January 2011 (2003 group), and after January 2011 (2011 group), when is considered as the beginning year of Chinese household vehicle era.Results: The study included 5095 thoracic trauma patients with mean age of 50.2 years, of whom 79.4% were male. Most of the patients (70.3%, n = 3583) had rib fractures. Associated injuries were present in 52.0% of the patients, of them 78.5% (n = 2080) were extremity fractures. Road traffic crashes accounted for 41.4% (n = 2108) of the injuries, most of them (98.0%) were related to motor vehicles. In comparison with other chest trauma mechanisms, RTCR chest injuries affected females and older males more frequently, with a higher incidence of rib fractures and sternum fractures, and higher injury severity scores (ISS) (all p < 0.05). Surgeries were required in 1495 (70.9%) patients of the RRTCR chest traumas, while the majority of non-RTCR thoracic injuries were managed conservatively or with tube thoracostomy (30.2%, n = 901). RTCR chest traumas caused longer hospital stay (13.0 ± 9.6 days vs. 11.8 ± 7.4 days, p = 0.001), higher ICU usage (30.7% vs. 19.6%, p = 0.001), higher rate of ventilator support (12.9% vs. 7.5%, p = 0.001), and higher mortalities (3.8% vs. 1.6%, p = 0.005) than that of non-RTRA chest injuries. For RTCR patients, when compared with 2003 group, 2011 group had similar patterns in terms of accident category, associated injury and treatment. However, 2011 group had more females (38.5% vs. 18.0%, p = 0.001) and older males (50.6 ± 9.7 vs. 47.9 ± 17.2, p = 0.001), with a higher ISS (18.3 ± 10.2 vs. 17.1 ± 8.9, p = 0.004), and fewer were managed with chest tubes (25.0% vs. 29.2%, p = 0.031). Clinical outcomes were not significantly different between the groups in terms of hospital length of stay, intensive care unit (ICU) usage, ICU length of stay, duration of ventilator hours and mortality. However, the 2011 group had more patients requiring ventilator support (14.4% vs. 10.6%, p = 0.011).Conclusions: Road traffic crashes remain to be the major etiology of thoracic injuries in China, which usually affects middle-aged males, causing rib fractures with concomitant injuries frequently occurring to other organ systems. Treatments mainly include tube thoracotomy and surgical procedures. Although the clinical characteristics and outcomes of traffic accident related chest traumas are largely unchanged in spite of the rapid increasing numbers of motor vehicles, variations in the pattern of injuries by gender, age, injury severity and ventilator usage may still provide important information for targeted management. [ABSTRACT FROM AUTHOR]

The initial in situ stress field is the fundamental factor causing the deformation and failure of underground engineering and is an important basis for the feasibility analysis, design, and construction of underground engineering. However, it is difficult to obtain the whole in situ stress field of large-scale underground engineering in difficult and dangerous areas by field measurement. In view of the fact that the measured in situ stress components (σxx, σyy, σzz, τxy, τxz, τyz) of Sichuan-Tibet Railway in China are linear with the buried depth, a method is proposed to solve the in situ stress by applying corresponding loads to all unit bodies in the calculation area based on BP neural network and FLAC3D. Through this method, the in situ stress of the tunnel is inverted. The results show that both the maximum principal stress and minimum principal stress increase with the increase of buried depth, and when the tunnel passes through faults or anticlines, the main stress will suddenly drop. Furthermore, compared with the results of the multiple linear regression method, it is found that the proposed method has higher accuracy; especially for the simulation of the maximum horizontal principal stress and vertical stress, the average relative error is reduced by 26.44% and 77.27%, respectively. The research in this paper can provide a new idea for the initial in situ stress inversion of engineering. [ABSTRACT FROM AUTHOR]

The inverse-distance weighting interpolation is widely used in 3D geological modeling and directly affects the accuracy of models. With the development of "smart" or "intelligent" geology, classical inverse-distance weighting interpolation cannot meet the accuracy, reliability, and efficiency requirements of large-scale 3D geological models in these fields. Although the improved inverse-distance weighting interpolation can basically meet the requirements of accuracy and reliability, it cannot meet the requirements of efficiency at the same time. In response to these limitations, the adaptive inverse-distance weighting interpolation method based on geological attribute spatial differentiation and geological attribute feature adaptation was proposed. This method takes into account the spatial differentiation of geological attributes to improve the accuracy and considers the first-order neighborhood selection strategy to adaptively improve efficiency to meet above requirements of large-scale geological modeling. The proposed method was applied to an area in eastern China, and the results of the proposed method, compared to the results of classical inverse-distance weighting interpolation and improved inverse-distance weighting interpolation, suggest that the problems encountered above in large-scale geological modeling can be solved with the proposed method. The method can provide effective support for large-scale 3D geological modeling in smart geology. [ABSTRACT FROM AUTHOR]

Displaying 3D geological models and performing corresponding analyses in web browsers are trends in "smart city" development, but these tasks are often limited by the web browser and network transmission; therefore, large quantities of data cannot be quickly displayed or analysed, thereby constraining 3D geological models implemented in web browsers. The data redundancy and computational complexity of 3D geological models must be urgently optimized. Because of the data structure, it is difficult to further optimize the data redundancy and computational complexity of the current commonly used triangular prism (TP) model. If the model is sufficiently large, it can be difficult to display and analyse information in a web browser. Therefore, a new data structure and algorithm are necessary to optimize the data and number of calculations in 3D geological models. Thus, this paper uses a two-dimensional projection to simplify the data and proposes a new data structure for a 3D geological model based on a vertically projected triangulated network (VPTN) to describe the TP model. Based on the vertical sides of a TP, the horizontal coordinates and topology of the 3D model can be recorded by a 2D vertically projected triangulated network. According to the new data structure, this paper proposes a corresponding cutting algorithm that takes advantage of a VPTN to increase the computational speed. The VPTN model and TP model of a city in eastern China are built. The comparison of the modelling and cutting results of the two models is carried out, and the results show that the VPTN model can completely record the spatial coordinate information and topological information of the 3D geological model, reduce the memory space occupied by the model and decrease the number of calculations. The research results meet the needs of rapidly displaying 3D geological models and performing related analyses with a large data volume in web browsers. Moreover, these findings provide a reference for further optimization of 3D geological models. • The data structure of VPTN model can record the 3D model by a 2D network. • The data structure of VPTN model can decrease the data volume of model. • The cutting algorithm can reduce the calculations in the cutting process. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effects of continuous monitoring intracranial pressure (ICP) and brain oxygen partial pressure (PbtO 2 ) on the prognosis of patients with severe craniocerebral injury., Methods: A prospective randomized controlled trial was conducted. Seventy patients with severe craniocerebral injury with a Glasgow coma score (GCS) 4-8 admitted to the neurosurgical intensive care unit (NICU) of the People's Hospital of Inner Mongolia Autonomous Region from January 2017 to May 2020 were enrolled, and they were divided into ICP monitoring group and ICP+PbtO 2 monitoring group by random number table. Patients in ICP monitoring group received ICP monitoring and were given traditional treatment of controlling ICP and cerebral perfusion pressure (CPP), the therapeutic target was ICP < 20 mmHg (1 mmHg = 0.133 kPa) and CPP > 60 mmHg. Patients in ICP+PbtO 2 monitoring group were given ICP and PbtO 2 monitoring at the same time, and oxygen flow was adjusted on the basis of controlling ICP and CPP to maintain the PbtO 2 > 20 mmHg, and the therapeutic target of ICP and CPP was the same as the ICP monitoring group. ICP and PbtO 2 values were recorded during monitoring in the two groups, the results of CPP, GCS and arterial blood gas analysis were recorded, and the prognosis at 3 months and 6 months after injury was compared by Glasgow outcome scale (GOS) score between the two groups. GOS score > 3 was considered as good prognosis. Kaplan-Meier survival curve was drawn, and the 3-month and 6-month cumulative survival rates of the two groups were analyzed. Linear regression analysis was used to further evaluate the relationship between PbtO 2 and GOS score., Results: Finally, a total of 70 patients with severe craniocerebral injury were enrolled in the analysis, 34 patients received ICP combined with PbtO 2 monitoring and guided therapy, and 36 patients received ICP monitoring alone. The average ICP of ICP+PbtO 2 monitoring group was significantly lower than that of ICP monitoring group (mmHg: 13.4±3.2 vs. 18.2±8.3, P < 0.01). Although the CPP in both groups was great than 60 mmHg, the average CPP of ICP+PbtO 2 monitoring group was significantly higher than that of ICP monitoring group (mmHg: 82.1±10.5 vs. 74.5±11.6, P < 0.01). No significant difference was found in average GCS score or arterial partial pressure of carbon dioxide (PaCO 2 ) between the ICP+PbtO 2 monitoring group and ICP monitoring group [GCS score: 5.3±2.3 vs. 5.2±2.2, PaCO 2 (mmHg): 33.5±4.8 vs. 32.6±5.2, both P > 0.05]. The average arterial partial pressure of oxygen (PaO 2 ) of ICP+PbtO 2 monitoring group was obviously higher than that of ICP monitoring group (mmHg: 228.4±93.6 vs. 167.3±81.2, P < 0.01). Compared with the ICP monitoring group, the good outcome rates of 3 months and 6 months after injury in the ICP+PbtO 2 monitoring group were significantly higher (3 months: 67.6% vs. 38.9%, 6 months: 70.6% vs. 41.7%, both P < 0.05). Kaplan-Meier survival curve showed that the 3-month and 6-month cumulative survival rates of ICP+PbtO 2 monitoring group were significantly higher than those of ICP monitoring group (3 months: 85.3% vs. 61.1%, Log-Rank test: χ 2 = 5.171, P = 0.023; 6 months: 79.4% vs. 55.6%, Log-Rank test: χ 2 = 4.511, P = 0.034). Linear regression analysis showed that PbtO 2 was significantly correlated with GOS score at 3 months and 6 months after injury in patients with severe craniocerebral injury (r values were 0.951 and 0.933, both P < 0.01)., Conclusions: PbtO 2 compared with ICP monitoring guiding therapy is valuable in improving the prognosis of patients with severe craniocerebral injury. It can improve the prognosis at 3-6 months after injury.