简介：AbstractBackground:A deep learning model (DLM) that enables non-invasive hypokalemia screening from an electrocardiogram (ECG) may improve the detection of this life-threatening condition. This study aimed to develop and evaluate the performance of a DLM for the detection of hypokalemia from the ECGs of emergency patients.Methods:We used a total of 9908 ECG data from emergency patients who were admitted at the Second Affiliated Hospital of Nanchang University, Jiangxi, China, from September 2017 to October 2020. The DLM was trained using 12 ECG leads (lead I, II, III, aVR, aVL, aVF, and V1-6) to detect patients with serum potassium concentrations <3.5 mmol/L and was validated using retrospective data from the Jiangling branch of the Second Affiliated Hospital of Nanchang University. The blood draw was completed within 10 min before and after the ECG examination, and there was no new or ongoing infusion during this period.Results:We used 6904 ECGs and 1726 ECGs as development and internal validation data sets, respectively. In addition, 1278 ECGs from the Jiangling branch of the Second Affiliated Hospital of Nanchang University were used as external validation data sets. Using 12 ECG leads (leads I, II, III, aVR, aVL, aVF, and V1-6), the area under the receiver operating characteristic curve (AUC) of the DLM was 0.80 (95% confidence interval [CI]: 0.77-0.82) for the internal validation data set. Using an optimal operating point yielded a sensitivity of 71.4% and a specificity of 77.1%. Using the same 12 ECG leads, the external validation data set resulted in an AUC for the DLM of 0.77 (95% CI: 0.75-0.79). Using an optimal operating point yielded a sensitivity of 70.0% and a specificity of 69.1%.Conclusions:In this study, using 12 ECG leads, a DLM detected hypokalemia in emergency patients with an AUC of 0.77 to 0.80. Artificial intelligence could be used to analyze an ECG to quickly screen for hypokalemia.

简介：AbstractObjective:To develop a downloadable three-dimensional (3D) study tool of the membranous labyrinth in order to facilitate the study of benign paroxysmal positional vertigo (BPPV).Background:The diagnosis and treatment of BPPV depend on an understanding of the anatomy of the vestibular labyrinth and its position relative to the head. To date, many illustrations have been made to explain principles of diagnosis and treatment of BPPV, but few have been based on anatomical studies of the membranous labyrinth.Methods:A previously reported 3D model of a human labyrinth was transposed to a 3D development software to allow the creation of markers along the semicircular ducts and utricle. These markers represent otoliths at different positions during movement of the model within the 3D environment. User-friendly tools were created to navigate the model, to allow clear documentation and communication of studied problems, and to study the model across relevant planes. The final model can be downloaded and is available for general useat https://bppvviewer.com/download/.Results:The model allows visualization of true membranous labyrinth anatomy in both ears simultaneously. The dependent portion of each semicircular duct, the planes of the cristae, and the position of the utricle can easily be visualized in any head position. Moveable markers can mark the expected progress of otolith debris with changes in head position and images can be captured to document simulations in various draw styles.Conclusion:This simple model could offer insights that lead to more accurate diagnosis and treatment of BPPV. It may also be useful as a tool to teach BPPV.

简介：AbstractBackground:Computed tomography images are easy to misjudge because of their complexity, especially images of solitary pulmonary nodules, of which diagnosis as benign or malignant is extremely important in lung cancer treatment. Therefore, there is an urgent need for a more effective strategy in lung cancer diagnosis. In our study, we aimed to externally validate and revise the Mayo model, and a new model was established.Methods:A total of 1450 patients from three centers with solitary pulmonary nodules who underwent surgery were included in the study and were divided into training, internal validation, and external validation sets (n = 849, 365, and 236, respectively). External verification and recalibration of the Mayo model and establishment of new logistic regression model were performed on the training set. Overall performance of each model was evaluated using area under receiver operating characteristic curve (AUC). Finally, the model validation was completed on the validation data set.Results:The AUC of the Mayo model on the training set was 0.653 (95% confidence interval [CI]: 0.613-0.694). After re-estimation of the coefficients of all covariates included in the original Mayo model, the revised Mayo model achieved an AUC of 0.671 (95% CI: 0.635-0.706). We then developed a new model that achieved a higher AUC of 0.891 (95% CI: 0.865-0.917). It had an AUC of 0.888 (95% CI: 0.842-0.934) on the internal validation set, which was significantly higher than that of the revised Mayo model (AUC: 0.577, 95% CI: 0.509-0.646) and the Mayo model (AUC: 0.609, 95% CI, 0.544-0.675) (P < 0.001). The AUC of the new model was 0.876 (95% CI: 0.831-0.920) on the external verification set, which was higher than the corresponding value of the Mayo model (AUC: 0.705, 95% CI: 0.639-0.772) and revised Mayo model (AUC: 0.706, 95% CI: 0.640-0.772) (P < 0.001). Then the prediction model was presented as a nomogram, which is easier to generalize.Conclusions:After external verification and recalibration of the Mayo model, the results show that they are not suitable for the prediction of malignant pulmonary nodules in the Chinese population. Therefore, a new model was established by a backward stepwise process. The new model was constructed to rapidly discriminate benign from malignant pulmonary nodules, which could achieve accurate diagnosis of potential patients with lung cancer.

简介：AbstractHypothesis:Three-dimensional (3D) printed temporal bones are comparable to cadaveric temporal bones as a training tool for otologic surgery.Background:Cadaveric temporal bone dissection is an integral part of otology surgical training. Unfortunately, availability of cadaveric temporal bones is becoming much more limited and concern regarding chemical and biological risks persist. In this study, we examine the validity of 3D-printed temporal bone model as an alternative training tool for otologic surgery.Methods:Seventeen otolaryngology trainees participated in the study. They were asked to complete a series of otologic procedures using 3D-printed temporal bones. A semi-structured questionnaire was used to evaluate their dissection experience on the 3D-printed temporal bones.Results:Participants found that the 3D-printed temporal bones were anatomically realistic compared to cadaveric temporal bones. They found that the 3D-printed temporal bones were useful as a surgical training tool in general and also for specific otologic procedures. Overall, participants were enthusiastic about incorporation of 3D-printed temporal bones in temporal bone dissection training courses and would recommend them to other trainees.Conclusion:3D-printed temporal bone model is a viable alternative to human cadaveric temporal bones as a teaching tool for otologic surgery.

简介：AbstractBackground:Deep brain stimulation (DBS) has seizure-suppressing effects but the molecular mechanisms underlying its therapeutic action remain unclear. This study aimed to systematically elucidate the mechanisms underlying DBS-induced seizure suppression at a molecular level.Methods:We established a macaque model of mesial temporal lobe epilepsy (mTLE), and continuous high-frequency hippocampus DBS (hip-DBS) was applied for 3 months. The effects of hip-DBS on hippocampus gene expression were examined using high-throughput microarray analysis followed by bioinformatics analysis. Moreover, the microarray results were validated using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analyses.Results:The results showed that chronic hip-DBS modulated the hippocampal gene expression. We identified 4119 differentially expressed genes and assigned these genes to 16 model profiles. Series test of cluster analysis showed that profiles 5, 3, and 2 were the predominant expression profiles. Moreover, profile 5 was mainly involved in focal adhesion and extracellular matrix-receptor interaction pathway. Nine dysregulated genes (Arhgap5, Col1a2, Itgb1, Pik3r1, Lama4, Fn1, Col3a1, Itga9, and Shc4) and three genes (Col1a2, Itgb1, and Flna) in these two pathways were further validated by qRT-PCR and Western blot analyses, respectively, which showed a concordance.Conclusion:Our findings suggest that hip-DBS could markedly reverse mTLE-induced abnormal gene expression. Findings from this study establish the basis for further investigation of the underlying regulatory mechanisms of DBS for mTLE.

简介：摘要：射电望远镜是通过接受外太空光线得到天体信息的一种科学设备[1]。我国的FAST天眼是世界最好的射电望远镜。对于FAST天眼，我们将探讨以下问题：在前先研究方向的基础上，通过计算调节后的馈源舱的接收比来与基准反射球面的接收比相比较，可以先计算调节后馈源舱的接收比，再算出基准反射球面的接收比。通过这两个接收比的比较来回馈不同的参数和方法，确定怎样调整能够成为最优解，使结果达到最优。

简介：AbstractBackground:The basis of individualized treatment should be individualized mortality risk predictive information. The present study aimed to develop an online individual mortality risk predictive tool for acute-on-chronic liver failure (ACLF) patients based on a random survival forest (RSF) algorithm.Methods:The current study retrospectively enrolled ACLF patients from the Department of Infectious Diseases of The First People’s Hospital of Foshan, Shunde Hospital of Southern Medical University, and Jiangmen Central Hospital. Two hundred seventy-six consecutive ACLF patients were included in the present study as a model cohort (n = 276). Then the current study constructed a validation cohort by drawing patients from the model dataset based on the resampling method (n = 276). The RSF algorithm was used to develop an individual prognostic model for ACLF patients. The Brier score was used to evaluate the diagnostic accuracy of prognostic models. The weighted mean rank estimation method was used to compare the differences between the areas under the time-dependent ROC curves (AUROCs) of prognostic models.Results:Multivariate Cox regression identified hepatic encephalopathy (HE), age, serum sodium level, acute kidney injury (AKI), red cell distribution width (RDW), and international normalization index (INR) as independent risk factors for ACLF patients. A simplified RSF model was developed based on these previous risk factors. The AUROCs for predicting 3-, 6-, and 12-month mortality were 0.916, 0.916, and 0.905 for the RSF model and 0.872, 0.866, and 0.848 for the Cox model in the model cohort, respectively. The Brier scores were 0.119, 0.119, and 0.128 for the RSF model and 0.138, 0.146, and 0.156 for the Cox model, respectively. The nonparametric comparison suggested that the RSF model was superior to the Cox model for predicting the prognosis of ACLF patients.Conclusions:The current study developed a novel online individual mortality risk predictive tool that could predict individual mortality risk predictive curves for individual patients. Additionally, the current online individual mortality risk predictive tool could further provide predicted mortality percentages and 95% confidence intervals at user-defined time points.

简介：AbstractBackground:Multiple techniques are commonly used for posterior cruciate ligament (PCL) reconstruction. However, the optimum method regarding the fixation of PCL reconstruction after PCL tears remains debatable. The purpose of this study was to compare the biomechanical properties among three different tibial fixation procedures for transtibial single-bundle PCL reconstruction.Methods:Thirty-six porcine tibias and porcine extensor tendons were randomized into three fixation study groups: the interference screw fixation (IS) group, the transtibial tubercle fixation (TTF) group, and TTF + IS group (n = 12 in each group). The structural properties of the three fixation groups were tested under cyclic loading and load-to-failure. The slippage after the cyclic loading test and the stiffness and ultimate failure load after load-to-failure testing were recorded.Results:After 1000 cycles of cyclic testing, no significant difference was observed in graft slippage among the three groups. For load-to-failure testing, the TTF + IS group showed a higher ultimate failure load than the TTF group and the IS group (876.34 ± 58.78 N vs. 660.92 ± 77.74 N [P < 0.001] vs. 556.49 ± 65.33 N [P < 0.001]). The stiffness in the TTF group was significantly lower than that in the IS group and the TTF + IS group (92.77 ± 20.16 N/mm in the TTF group vs. 120.27 ± 15.66 N/m in the IS group [P = 0.001] and 131.79 ± 17.95 N/mm in the TTF + IS group [P < 0.001]). No significant difference in the mean stiffness was found between the IS group and the TTF + IS group (P = 0.127).Conclusions:In this biomechanical study, supplementary fixation with transtibial tubercle sutures increased the ultimate failure load during load-to-failure testing for PCL reconstruction.

简介：AbstractBackground:Accurate prediction of ischemic stroke is required for deciding anticoagulation use in patients with atrial fibrillation (AF). Even though only 6% to 8% of AF patients die from stroke, about 90% are indicated for anticoagulants according to the current AF management guidelines. Therefore, we aimed to develop an accurate and easy-to-use new risk model for 1-year thromboembolic events (TEs) in Chinese AF patients.Methods:From the prospective China Atrial Fibrillation Registry cohort study, we identified 6601 AF patients who were not treated with anticoagulation or ablation at baseline. We selected the most important variables by the extreme gradient boosting (XGBoost) algorithm and developed a simplified risk model for predicting 1-year TEs. The novel risk score was internally validated using bootstrapping with 1000 replicates and compared with the CHA2DS2-VA score (excluding female sex from the CHA2DS2-VASc score).Results:Up to the follow-up of 1 year, 163 TEs (ischemic stroke or systemic embolism) occurred. Using the XGBoost algorithm, we selected the three most important variables (congestive heart failure or left ventricular dysfunction, age, and prior stroke, abbreviated as CAS model) to predict 1-year TE risk. We trained a multivariate Cox regression model and assigned point scores proportional to model coefficients. The CAS scheme classified 30.8% (2033/6601) of the patients as low risk for TE (CAS score = 0), with a corresponding 1-year TE risk of 0.81% (95% confidence interval [CI]: 0.41%-1.19%). In our cohort, the C-statistic of CAS model was 0.69 (95% CI: 0.65-0.73), higher than that of CHA2DS2-VA score (0.66, 95% CI: 0.62-0.70, Z = 2.01, P = 0.045). The overall net reclassification improvement from CHA2DS2-VA categories (low = 0/high ≥1) to CAS categories (low = 0/high ≥1) was 12.2% (95% CI: 8.7%-15.7%).Conclusion:In Chinese AF patients, a novel and simple CAS risk model better predicted 1-year TEs than the widely-used CHA2DS2- VA risk score and identified a large proportion of patients with low risk of TEs, which could potentially improve anticoagulation decision-making.Trial Registration:www.chictr.org.cn (Unique identifier No. ChiCTR-OCH-13003729).

简介：AbstractBackground:A new candidate vector vaccine against human brucellosis based on recombinant influenza viral vectors (rIVV) subtypes H5N1 expressing Brucella outer membrane protein (Omp) 16, L7/L12, Omp19 or Cu-Zn SOD proteins has been developed. This paper presents the results of the study of protection of the vaccine using on guinea pigs, including various options of administering, dose and frequency. Provided data of the novel vaccine candidate will contribute to its further movement into the preclinical stage study.Methods:General states of guinea pigs was assessed based on behavior and dynamics of a guinea pig weight-gain test. The effectiveness of the new anti-brucellosis vector vaccine was determined by studying its protective effect after conjunctival, intranasal and sublingual administration in doses 105 EID50, 106 EID50 and 107 EID50 during prime and boost vaccinations of animals, followed by challenge with a virulent strain of B. melitensis 16 M infection. For sake of comparison, the commercial B. melitensis Rev.1 vaccine was used as a control. The protective properties of vaccines were assessed by quantitation of Brucella colonization in organs and tissues of infected animals and compared to the control groups.Results:It was observed a gradual increase in body weight of guinea pigs after prime and booster immunization with the vaccine using conjunctival, intranasal and sublingual routes of administration, as well as after using various doses of vaccine. The most optimal way of using the vaccine has been established: double intranasal immunization of guinea pigs at a dose of 106 EID50, which provides 80% protection of guinea pigs from B. melitensis 16 M infection (P < 0.05), which is comparable to the results of the effectiveness of the commercial B. melitensis Rev.1 vaccine.Conclusions:We developed effective human vaccine candidate against brucellosis and developed its immunization protocol in guinea pig model. We believe that because of these studies, the proposed vaccine has achieved the best level of protection, which in turn provides a basis for its further promotion.

简介：AbstractObjective:Metabolic disorders are markedly common in women with polycystic ovary syndrome (PCOS), and nonalcoholic fatty liver disease (NAFLD) is observed in 30%-55% of all PCOS patients. Many studies have reported that autophagy and apoptosis, which are closely related to mitochondrial function, play important roles in the development of NAFLD. Therefore, in this study, we aimed to explore the role of mitochondrial dysfunction caused by liver apoptosis and autophagy imbalance in the development of NAFLD in a PCOS mouse model.Methods:We used a dihydrotestosterone (DHT)-induced PCOS model to mimic the pathological process of hyperandrogenism. Hematoxylin and eosin and Oil Red O staining assays were used to observe the pathological changes in the liver. Western blotting and quantitative real-time polymerase chain reaction were used to perform mitochondrion-related assays.Results:Hepatic steatosis and different degrees of inflammation were observed in the DHT-treated mice. The expression of molecules involved in the respiratory chain and aerobic respiration process was altered. The levels of the key molecules associated with apoptosis and autophagy were abnormal.Conclusions:Androgens may play a role in the process of hepatic steatosis development by affecting mitochondrial function and subsequently inducing apoptosis and autophagy. Such phenomena might be involved in the pathogenesis of NAFLD in women with PCOS.

简介：AbstractBackground:Prenatal evaluation of fetal lung maturity (FLM) is a challenge, and an effective non-invasive method for prenatal assessment of FLM is needed. The study aimed to establish a normal fetal lung gestational age (GA) grading model based on deep learning (DL) algorithms, validate the effectiveness of the model, and explore the potential value of DL algorithms in assessing FLM.Methods:A total of 7013 ultrasound images obtained from 1023 normal pregnancies between 20 and 41 + 6 weeks were analyzed in this study. There were no pregnancy-related complications that affected fetal lung development, and all infants were born without neonatal respiratory diseases. The images were divided into three classes based on the gestational week: class I: 20 to 29 + 6 weeks, class II: 30 to 36 + 6 weeks, and class III: 37 to 41 + 6 weeks. There were 3323, 2142, and 1548 images in each class, respectively. First, we performed a pre-processing algorithm to remove irrelevant information from each image. Then, a convolutional neural network was designed to identify different categories of fetal lung ultrasound images. Finally, we used ten-fold cross-validation to validate the performance of our model. This new machine learning algorithm automatically extracted and classified lung ultrasound image information related to GA. This was used to establish a grading model. The performance of the grading model was assessed using accuracy, sensitivity, specificity, and receiver operating characteristic curves.Results:A normal fetal lung GA grading model was established and validated. The sensitivity of each class in the independent test set was 91.7%, 69.8%, and 86.4%, respectively. The specificity of each class in the independent test set was 76.8%, 90.0%, and 83.1%, respectively. The total accuracy was 83.8%. The area under the curve (AUC) of each class was 0.982, 0.907, and 0.960, respectively. The micro-average AUC was 0.957, and the macro-average AUC was 0.949.Conclusions:The normal fetal lung GA grading model could accurately identify ultrasound images of the fetal lung at different GAs, which can be used to identify cases of abnormal lung development due to gestational diseases and evaluate lung maturity after antenatal corticosteroid therapy. The results indicate that DL algorithms can be used as a non-invasive method to predict FLM.

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简介：AbstractBackground:Models to predict mortality in trauma play an important role in outcome prediction and severity adjustment, which informs trauma quality assessment and research. Hospitals in China typically use the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) to describe injury. However, there is no suitable prediction model for China. This study attempts to develop a new mortality prediction model based on the ICD-10-CM lexicon and a Chinese database.Methods:This retrospective study extracted the data of all trauma patients admitted to the Beijing Red Cross Emergency Center, from January 2012 to July 2018 (n = 40,205). We used relevant predictive variables to establish a prediction model following logistic regression analysis. The performance of the model was assessed based on discrimination and calibration. The bootstrapping method was used for internal validation and adjustment of model performance.Results:Sex, age, new region-severity codes, comorbidities, traumatic shock, and coma were finally included in the new model as key predictors of mortality. Among them, coma and traumatic shock had the highest scores in the model. The discrimination and calibration of this model were significant, and the internal validation performance was good. The values of the area under the curve and Brier score for the new model were 0.9640 and 0.0177, respectively; after adjustment of the bootstrapping method, they were 0.9630 and 0.0178, respectively.Conclusions:The new model (China Mortality Prediction Model in Trauma based on the ICD-10-CM lexicon) showed great discrimination and calibration, and performed well in internal validation; it should be further verified externally.

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简介：[摘要]本文对航空某型号研制阶段机械加工标准的应用现状进行了调查研究，对标准的应用效果和对型号研制过程的驱动作用进行了阐述，对标准化过程中存在的问题进行了分析。通过本次研究可以发现，机械加工标准在新研型号的研制过程中已经得到了广泛而有效的应用，标准的应用对型号研制起到了良好的驱动作用，明显缩短了型号的研制周期提高了产品质量，同时标准作为良好的载体使航空技术、经验和创新成果得到了固化和广泛知会。

简介：AbstractBackground:Anterior thalamic nuclei (ATN) deep brain stimulation (DBS) is an effective method of controlling epilepsy, especially temporal lobe epilepsy. Mossy fiber sprouting (MFS) plays an indispensable role in the pathogenesis and progression of epilepsy, but the effect of ATN-DBS on MFS in the chronic stage of epilepsy and the potential underlying mechanisms are unknown. This study aimed to investigate the effect of ATN-DBS on MFS, as well as potential signaling pathways by a kainic acid (KA)-induced epileptic model.Methods:Twenty-four rhesus monkeys were randomly assigned to control, epilepsy (EP), EP-sham-DBS, and EP-DBS groups. KA was injected to establish the chronic epileptic model. The left ATN was implanted with a DBS lead and stimulated for 8 weeks. Enzyme-linked immunosorbent assay, Western blotting, and immunofluorescence staining were used to evaluate MFS and levels of potential molecular mediators in the hippocampus. One-way analysis of variance, followed by the Tukey post hoc correction, was used to analyze the statistical significance of differences among multiple groups.Results:ATN-DBS is found to significantly reduce seizure frequency in the chronic stage of epilepsy. The number of ectopic granule cells was reduced in monkeys that received ATN stimulation (P < 0.0001). Levels of 3′,5′-cyclic adenosine monophosphate (cAMP) and protein kinase A (PKA) in the hippocampus, together with Akt phosphorylation, were noticeably reduced in monkeys that received ATN stimulation (P = 0.0030 and P = 0.0001, respectively). ATN-DBS also significantly reduced MFS scores in the hippocampal dentate gyrus and CA3 sub-regions (all P < 0.0001).Conclusion:ATN-DBS is shown to down-regulate the cAMP/PKA signaling pathway and Akt phosphorylation and to reduce the number of ectopic granule cells, which may be associated with the reduced MFS in chronic epilepsy. The study provides further insights into the mechanism by which ATN-DBS reduces epileptic seizures.

简介：【摘要】目的：探索封闭式应急管理模式在急诊新型冠状病毒肺炎疫情爆发期间的应用，为此后更好地应对突发公共卫生事件提供科学决策依据。方法：选择2019年11月-12月在急诊按常规工作模式就诊的4221例患者作为对照组，将2020年2月-3月新冠疫情期间前往急诊就诊的患者3252例作为试验组，开展封闭式应急管理模式，其主要措施包括组建急诊抗新冠肺炎疫情应急管理队伍、工作流程及规章制度的修订、隔离诊治传染源、完善疫情信息监测，加快疑似病例诊断、加强医护人员个人防护管理和院内感染防控和对高危人群开展追踪随访等，探究封闭式应急管理模式在急诊的运用效果。结果：疫情期间急诊开展封闭式应急管理模式取得了较好的成果，与对照组相比，前来就诊患者的预检时间、急诊停留时间、转诊时间、补液量都较过去减少；急诊患者满意度量表各维度接待和咨询、答疑解惑、服务态度、护士技术、保护隐私、环境及次序、等候时间、护士巡视和用药指导得分均显著高于对照组，差异具有统计学意义（P＜0.05）。结论：创立高效、有序的封闭式应急管理模式为急诊应对突发公共卫生事件的医疗、护理和防护事宜提供了保障，同时也提高了急诊管理者的组织协调和应急处理能力。