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Most of the existing accurate positioning systems for underground personnel are based on UWB positioning technology and adopt the layout mode of personnel positioning card + positioning substation, which can achieve centimeter-level high-precision positioning without occlusion. When underground personnel travel, it is difficult to achieve accurate positioning of passengers due to the influence of a large range of metal occlusion of mining vehicles and dense factors in the compartment on positioning accuracy. To address the above issues, a method for identifying and locating underground personnel in a vehicle is designed. The status of personnel in a vehicle is recognized through multiple information such as vehicle speed monitoring, positioning card posture, and in-vehicle distance measurement. While the onboard positioning card measures distance with the positioning substation in the tunnel, the information of passengers in a vehicle is transmitted to the positioning substation through message reuse, the positioning substation uploads passenger information to the ground data center through the mine ring network. The test results show that the method has a high accuracy in identifying personnel in a vehicle, and the location information of passengers is synchronized with the vehicle position, which can effectively solve the positioning problem of underground personnel boarding.

Predicting the thickness distribution of different types of continental lithofacies is a fundamental task for selecting and evaluating continental shale oil-rich zones. Research on oil-bearing conditions, reservoir characteristics, and mobility of different types of lithofacies plays an important role in target area selection and the deployment of horizontal well sections. Based on core observation and logging identification, spectrum analysis of logging data was carried out. Stable astronomical orbital time cycles were introduced to perform spatio-temporal tuning. A high-frequency sequence isochronous lattice for drilling well comparison was established and the planar thickness variation trends of different types of lithofacies in each sequence cycle were quantitatively calculated, providing insights into lithofacies distribution patterns. Research on the 7th member (Chang 7) of Triassic Yan-chang Formation in the Fuxian area of the southern Ordos Basin showed that the natural gamma logging curves contained several sets of astronomical cycle information, among which 6 complete stable 405 kyr long eccentricity astronomical cycles could be identified. Based on the observation of the whole core section of Chang 7 member in well R203 and logging facies characteristics analysis, a reasonable high-frequency isochronous lattice was established for well-to-well comparison. The results showed that mud shale and laminated shale mainly developed in the bottom cyclic strata from Chang 73 to Chang 72 sub-member, and the fine-grained sandstone and siltstone were mostly developed in strata of cycles Ⅳ to Ⅴ from the middle and upper parts of Chang 72 to the bottom of Chang 71. Lateral comparison between wells showed that the mud shale and laminated shale lithofacies in the early cycles were widely distributed. During cycle Ⅰ period, these facies were mainly distributed in the southwest of the study area, and during cycle Ⅱ period, they were distributed in the west and east-northeast, with thicker storage in the central area. The fine-grained sandstone thickness distribution in strata of cycles Ⅳ to Ⅴ was controlled by a northeast-southwest sedimentary system, with a planar distribution from the north-northeast to the south-southwest, further extending to the southwest along wells ZF 27 to ZF 32. Three types of source and reservoir combinations were formed in Chang 7 member. The combination of laminated shale and fine-grained sandstone lithofacies occurred from the middle and upper parts of Chang 73 and Chang 72 sub-members to the lower part of Chang 71 sub-member, primarily distributed in the central-north, north, and northeast parts of the Fuxian area. The shale lithofacies thickness was well developed in Chang 73 sub-member, mainly distributed in the northeast, east, and southwest regions of the Fuxian area.

Most of the existing accurate positioning systems for underground personnel adopt UWB positioning technology, which is based on the layout mode of personnel positioning card + positioning substation to achieve centimeter-level high precision positioning. However, the existing models ignore the complexity of the working face environment, the influence of the change of the location of the base station installed with hydraulic support on the positioning accuracy, as well as the difficulty of field installation and other factors. To solve the above problems, a low power consumption positioning system for fully mechanized mining face is designed, which adopts Bluetooth positioning and LoRa wireless technology. The locator is used as a beacon and powered by battery, which can be installed in any position of the working face. Personnel positioning card integrates Bluetooth positioning and LoRa wireless technology, and integrates with mining lamp to form information mining lamp; the substation fusion LoRa wireless module is installed at both ends of the fully mechanized face to collect and transmit location information. The system can be compatible with the existing personnel accurate positioning system, and avoid the problems that the existing technology is difficult to solve in the positioning of fully mechanized mining face. It has the advantages of convenient installation, low cost and easy maintenance.

Breakthrough of the exploration of deep shale gas in the Sichuan Basin, Southwest China, has been achieved for decades, there are still some controversies about the adsorption performance and occurrence state of shale gas in deep strata. Isothermal adsorption experiments were carried out under high temperature and high pressure with typical shale samples from deep stratum of the Lower Silurian Longmaxi Formation in Fuling and Dingshan areas in the southeastern Sichuan Basin. Results show that there is a big difference between absolute adsorption and excess adsorption, thus, it is proposed that the excess adsorption capacity should be corrected to the absolute adsorption capacity when evaluating the adsorption performance of deep shale gas. After correction, the variation of absolute shale adsorption with pressure appeared to have three stages including "rapid rise", "slow rise" and "steady rise". The absolute adsorption capacity of deep shale samples from Fuling and Dingshan areas is higher than 2.0 m3/t at 110℃ and 70 MPa, and combined with the adsorption and free gas ratios of deep shale, the total gas content is more than 4.0 m3/t, indicating that deep shale may still have good adsorption performance under high temperature and high pressure. The evaluation of deep shale adsorption capacity can provide reliable parameters for the study of shale gas content and the evaluation of resource potential and reserve for shale gas. Considering the difference of ratio of free gas to adsorbed gas between deep shale and shallow-medium shale, different exploration and production methods can be adopted to effectively improve the production capacity and production cycle of shale gas.

Dispersion of the signal energy and the inter symbol interference（ISI）is caused by the multipath fading in 60GHz pulse communication environment.To solve this problem,the severity of the ISI in the system was analyzed,and the method to eliminate interference was studied.Based on the 60GHz wireless channel model established by IEEE 802.15.3c,the simulation platform of 60GHz pulse communication system was built.Theoretical analysis and numerical simulation of ISI in the system were carried out,and a receiver scheme of combining Rake receiver and equalizer was designed.Results show that,the two taps MRC-Rake receiver module combined with MMSE linear equalization module can not only improve the signal energy by multipath diversity,but also eliminate ISI.The performance of the system was improved without increasing the complexity.The scheme provides a reference for the design of 60GHz pulse communication system in the future.

Objective: To understand and analyze the situation of contraceptive use among women seeking abortions in Shanghai. Methods: The computer-assisted anonymous questionnaire was used to collect data among 1 261 women seeking abortions in 4 hospitals in Shanghai from August to October in 2013. Results: Nearly 60% of the respondents were under the age of 29 and 32.6% were unmarried. Over 50% of the respondents reported having abortion experiences before. Compared with those married women, the unmarried women had a higher proportion of unprotected intercourse (48.0% vs. 33.9%) and a lower proportion of contraceptive use failure (38.6% vs. 47.8%). Logistic regression analysis indicated that younger or sexually inactive women tended not to take contraceptive measures among those married respondents, and that those women who were young, unmarried, with a higher income or a history of abortion were more likely to use emergency contraception. Conclusions: Young women with high proportion of repeated abortion constituted the majority of respondents in Shanghai. Two main factors of unwanted pregnancy are the low proportion of contraceptive use and the high proportion of failure use of contraceptives. It is important to strengthen the post-abortion care services and the contraceptive education, especially to teach them how to use contraceptives, because those induced abortion women were lack of contraceptive precaution or knowledge. [ABSTRACT FROM AUTHOR]

Objective To investigate the expression and role of the DNA repair and recombination protein RAD54-like (RAD54L) in oral squamous cell carcinoma (OSCC). Methods Using OSCC-related data from The Cancer Genome Atlas (TCGA) database, the difference in RAD54L expression between OSCC and control samples was analysed using the Mann-Whitney rank sum test, and the potential value of RAD54L mRNA in OSCC diagnosis was assessed using the receiver operator characteristic curve. The correlation between RAD54L expression levels and clinicopathological data of OSCC patients was analysed using the chi-square test. Once OSCC samples were divided into two groups of high and low expression based on the median value of RAD54L mRNA expression, Cox regression analysis was used to compare the prognostic differences between the two groups. The differentially expressed genes between the groups were subsequently screened using the DESeq2 package, and KEGG pathway enrichment analysis was performed using the clusterProfiler package. The correlation between RAD54L mRNA and gene expression in the homologous recombination repair pathway was demonstrated by Spearman correlation analysis. After clarifying the bioinformatics significance of RAD54L, RAD54L knockdown experiments were performed in human oral squamous carcinoma cell line HSC-3, and the knockdown efficiency was verified through real-time quantitative polymerase chain reaction. After transfection, the changes in proliferation, migration, apoptosis, and cycle of HSC-3 cells were assessed by CCK-8, 5-ethynyl-2'-deoxyuridine (EdU) staining, wound healing, apoptosis, and cell cycle assays. Results Bioinformatics analysis showed that the expression of RAD54L mRNA was higher in OSCC than in normal controls (PAUC = 0.927). The high RAD54L expression group was associated with an increased proportion of male patients (P = 0.032), having a higher T-stage (P = 0.040), clinical stage (P = 0.027), and pathological grading (P = 0.013). Once OSCC samples were divided into two groups of high and low expression using the median value of RAD54L mRNA expression, the prognosis of the group with high expression of RAD54L was poorer than that of the group with low expression (P = 0.049). The differentially expressed genes between the high and low RAD54L expression groups two groups were mainly enriched in neuroactive ligand-receptor interactions, cytokine-cytokine receptor interactions, calcium signaling pathway, cell cycle, gastric cancer, extracellular matrix receptor interactions, chemical carcinogenesis-DNA adducts, DNA replication, homologous recombination, and mismatch repair pathways (PPR>0.8, Pin vitro experiments showed that RAD54L expression was knocked down to approximately 25% in HSC-3 cells (PPPPPPP

Accurately estimating the state of health (SOH) of lithium-ion batteries is of great significance in ensuring the safe operation of the battery system. Addressing the issue where traditional SOH estimation methods fail under variable working conditions, an online SOH estimation method for lithium-ion batteries based on equivalent circuit model (ECM) and sparse Gaussian process regression (SGPR) is proposed. During the constant current charging process, the parameters of the ECM of lithium-ion battery are dynamically identified by two online filters, based on which, a condition-insensitive health indicator is constructed. In combination with the SGPR, the indirect SOH estimation is achieved. This method uses the unified signal processing method and feature mapping model under various working conditions, and features strong robustness with low redundancy. The experimental results show that the average absolute error of the method proposed under various working conditions does not exceed 0.94%, and the root mean square error stays below 1.12%. When benchmarked against existing methods, this method has significant advantages in comprehensive performance.

In this paper, time source sinking deployment scheme for the 5th Generation Mobile Communication Technology (5G) synchronization network is analyzed. Compared with the centralized deployment scheme, this paper analyzes the application scenario, advantages and deployment ideas of the source sinking deployment. The techniques of synchronization domain division, synchronization protection and control in the scheme are discussed, and corresponding solutions and suggestions are proposed. Finally, combined with the practice of domestic synchronization network, the evolution mode of time source sinking application is analyzed. The analysis results provide guidance for ongoing 5G synchronous networking technology research and scale deployment.

Objective To explore the simulation degree of the 3D printed removable transnasal pituitary adenoma resection model, and to discuss the possibility of teaching operation with the model. Methods Using patient CT modeling, fine optimization and 3D printed technology, a removable pituitary adenoma resection model was constructed. Nineteen evaluators from Peking Union Medical College Hospital were selected, who were divided into “lower seniority group”(seniority ＜10 years) and “higher seniority group” (seniority ≥10 years). Each physician operated on the 3D printed pituitary adenoma resection model. They filled out questionnaires and evaluation scales before and after the operation. Results The higher seniority group have more operation experience than the lower seniority group. The scores of the simulation degree items are all around 4, and there is no significant difference found in different scoring items. The simulation degree score of “pituitary adenoma removal” is relatively low. The scores from the higher seniority group are generally lower than those of the lower seniority group. Before the operation, the scores in the lower seniority group were significantly lower than those of the higher seniority group, while the confidence scores of the two groups after the operation tended to be the same. The difference between scores before and after operation were significantly higher in lower seniority group (P＜0.05). Conclusions The model has high simulation degree and can be used in teaching experiments.

Objective To investigate the effect of LINGO-1 shRNA (LV) and neurotrophic factors cocktail (NTFs,NTFcocktail) encapsulated by Pluronic F-127(PF-127)hydrogel (PF-127-LV-NTFs)three-dimensional(3D) composite scaffolds on the proliferation and differentiation of rat neural stem cells. Methods The LV was constructed and infected with NSCs at different MOI. RT-qPCR and Western blot were used to detect the expression of LINGO-1 in NSCs. Brain derived neurotropic factor(BDNF), neurotrophin-3(NT-3), platelet-derived growth factor(PDGF),insulin-like growth factor 1(IGF-1), epidermat growth factor(EGF), basic fibroblast growth factor(bFGF) and glial cell derived neurotrophic factor(GDNF) were prepared as NTFs. The LV and NTFs were mixed with PF-127 and divided into different groups to culture NSCs. CCK-8 was used to detect the cell viability of NSCs, the survival rate of NSCs was detected by LIVE/DEAD staining, and immunofluorescence staining was used to detect the proliferation and differentiation of NSCs. Results The optimal MOI for LV was 5. CCK-8 assay results showed that there was no significant difference in the survival rate of NSCs. The LIVE/DEAD and Nestin immune-fluorescence staining results showed that compared with control, the survival rate of NSCs and the proportion of neuron differentiation positive were the highest in PF-127+LV+NTF group(P＜0.01). Conclusions PF-127-LV-NTFs 3D composite scaffold is favouring to support the proliferation and the directional differentiation of NSCs of rat.

The treatment of pediatric brain tumors is an important branch of pediatric neurosurgery. Children's brain tumors are treated differently from adults because of the unique structure of their physical development. This paper reviews the milestones in the treatment of children's brain tumors at home and abroad and discusses the key technologies for the diagnosis and treatment of children's brain tumors, so as to look into the future. DOI：10.3969/j.issn.1672⁃6731.2020.04.003

Objective: To study how hepatitis B virus(HBV) 'a' determinant hotpoint mutations were influecing the hepatitis B vaccine efficacy., Methods: Primers were designed in HBV conservative region, and the degenerate probes for detecting 16 'a' determinant hotpoint mutations were developed for gene chips. Sensitivity and specificity of the gene chips were evaluated by clone sequencing. Sera of 47 pairs of mothers and infants with immune failure and 323 mothers of children with immune protection of HB vaccine were detected by the gene chips., Results: Result from clone sequencing demonstrated that the gene chips were specific for the detection of 'a' determinant hotpoint mutations. The wild type of HBV was still dominant, with the prevalence of 78.66%, and the mutation frequencies of 126A, 145R, 126S-1, 126S-2, 129H, 144A, and 129R were 11.27%, 5.76%, 5.28%, 4.56%, 1.20%, 0.72% and 0.24%, respectively. The prevalence of 126A mutation was significantly higher than that of other mutations(P < 0.01). No significant differences were found in mother-infant transmission rates of 126A, 126S-1, 126S-2 and 145R variants., Conclusion: The currently available hepatitis B vaccine could block mother-infant transmission of 126A, 126S and 145R variants. It appears that there is no need to develop a new hepatitis B vaccine against 126 and 145 variants at present, but the consistent epidemiological surveillance on HBV mutants should be carried out.