Electrocardiogram (ECG) is a noninvasive, inexpensive, and convenient test for diagnosing cardiovascular diseases and assessing the risk of cardiovascular events. Although there are clear standardized operations and procedures for ECG examination, the interpretation of ECG by even trained physicians can be biased due to differences in diagnostic experience. In recent years, artificial intelligence has become a powerful tool to automatically analyze medical data by building deep neural network models, and has been widely used in the field of medical image diagnosis such as CT, MRI, ultrasound and ECG. This article mainly introduces the application progress of deep neural network models in ECG diagnosis and prediction of cardiovascular diseases, and discusses its limitations and application prospects.
Objective To monitor the release of amino acids of the whole retina during and after experimental glaucoma by increasing the intraocular pressure （IOP）． Methods Experimental glaucoma was induced in one of the two eyes of rabbits by increasing IOP at 120 mm Hg for 45 min under infusion of saline in anterior chamber；then the pressure was released and the needle inserted into the anterior chamber was removed，this state was maintained for another 45 min．Every 15 min during the experiment 5 rabbits were killed and experimental eyes were enucleated．Aliquots（20 μl）of the retinal extracts（see below）were mixed with ophthaldialdehyde reagent and analysed for amino acid content by the HPLC method of Wangwei，using a 150 mm×4.6 mm,5 μm C18 column． Results A large increase in the release of glutamate，but not of the other three amino acids monitored，occurred during initial experimental ocular hypertension．It reached peak value of（111.73±17.46）10-5 mmol/g at 15 min of hypertension．15 min after release of intraocular pressure，again，immediately large and specific increase in the concentration of glutamate was reached to（102.96±51.91）10-5 mmol/g．In eyes subjected to paracentesis of anterior chamber，no difference was found between experimental eyes and controls. Conclusion These results suggest that glutamate is triggered by increasing the IOP，and it releases not only during the period of experimental ocular hypertension，but also afterwards. (Chin J Ocul Fundus Dis, 2002, 18: 146-148)
Objectives To investigate the expression of pax-6 in ret ina of in fant monkeys with myopia induced by optical defocus, and to determine the role of pax-6 would play or not in onset and development of myopia and emmetropization.Methods Nine healthy infant rhesus monkeys, aged from 1 to 3 months, were selected and wore spectacle lenses or underwent photorefractive keratectomy (PRK).Transcription polymerase chain reaction method and quantitative analysis were used to determine the expression of pax-6 in the retina with myopia induced by optical defocus in different time, and the result was compared with that in retina without myopia.Results The myopia caused by hyperopic defocus was found. The expression of pax-6 in the retina with myopia induced by optical defocus was significantly higher than that in the retina without myopia（t=3.480，P=0.004）.Conclusions The expression of pax-6 is enhanced by hyperopic defocus in the infant monkey retina, which suggests that pax-6 may be involved in vision-dependent eye growth and emmetropization. (Chin J Ocul Fundus Dis，2003，19：201-268)
In the study of oral orthodontics, the dental tissue models play an important role in finite element analysis results. Currently, the commonly used alveolar bone models mainly have two kinds: the uniform and the non-uniform models. The material of the uniform model was defined with the whole alveolar bone, and each mesh element has a uniform mechanical property. While the material of the elements in non-uniform model was differently determined by the Hounsfield unit (HU) value of computed tomography (CT) images where the element was located. To investigate the effects of different alveolar bone models on the biomechanical responses of periodontal ligament (PDL), a clinical patient was chosen as the research object, his mandibular canine, PDL and two kinds of alveolar bone models were constructed, and intrusive force of 1 N and moment of 2 Nmm were exerted on the canine along its root direction, respectively, which were used to analyze the hydrostatic stress and the maximal logarithmic principal strain of PDL under different loads. Research results indicated that the mechanical responses of PDL had been affected by alveolar bone models, no matter the canine translation or rotation. Compared to the uniform model, if the alveolar bone was defined as the non-uniform model, the maximal stress and strain of PDL were decreased by 13.13% and 35.57%, respectively, when the canine translation along its root direction; while the maximal stress and strain of PDL were decreased by 19.55% and 35.64%, respectively, when the canine rotation along its root direction. The uniform alveolar bone model will induce orthodontists to choose a smaller orthodontic force. The non-uniform alveolar bone model can better reflect the differences of bone characteristics in the real alveolar bone, and more conducive to obtain accurate analysis results.
ObjectiveTo explore the risk factors for accompanying depression in patients with community type Ⅱ diabetes and to construct their risk prediction model. MethodsA total of 269 patients with type Ⅱ diabetes accompanied with depression and 217 patients with simple type Ⅱ diabetes from three community health service centers in two streets of Pingshan District, Shenzhen from October 2021 to April 2022 were included. The risk factors were analyzed and screened out, and a logistic regression risk prediction model was constructed. The goodness of fit and prediction ability of the model were tested by the Hosmer-Lemeshow test and the receiver operating characteristic (ROC) curve. Finally, the model was verified. ResultsLogistic regression analysis showed that smoking, diabetes complications, physical function, psychological dimension, medical coping for face, and medical coping for avoidance were independent risk factors for depressive disorder in patients with type Ⅱ diabetes. Modeling group Hosmer-Lemeshow test P=0.345, the area under the ROC curve was 0.987, sensitivity was 95.2% and specificity was 98.6%. The area under the ROC curve was 0.945, sensitivity was 89.8%, specificity was 84.8%, and accuracy was 86.8%, showing the model predictive value. ConclusionThe risk prediction model of type Ⅱ diabetes patients with depressive disorder constructed in this study has good predictive and discriminating ability.
ObjectiveTo summarise the application research progress of clinical prediction models in postoperative complications of gastric cancer, in order to reduce the risk of complications after gastric cancer surgery. MethodThe literature on the study of postoperative complications of gastric cancer at home and abroad was read and reviewed. ResultsAt present, the main way of treating gastric cancer was still radical resection, and the occurrence of complications after surgical treatment seriously affected the recovery and survival quality of patients. With the deepening of research, the prediction models of postoperative complications in gastric cancer were constantly constructed, and these models provided strong evidence for the early judgement of postoperative complications in gastric cancer, and provided a scientific basis for the improvement of patients’ life quality. ConclusionClinical predictive models are expected to become risk screening tools for predicting the risk of postoperative complications of gastric cancer with clinical utility.
Objective To observe the pathological and functional changes of retinal photochemical damages exposed to green flurescent light. Methods The Sprague Dawley rats were continually exposed to green fluorescent light with an illuminancem level of (1 900plusmn;106.9) Lx for 24 hours.The changes of retinal morphology and morphometrics and flash electroretinogram were studied before light exposure and at the 6th hour,6th day and 14th day after light exposure. Results At the 6th hours after light exposure,the outer nuclear layer(ONL)of retina becoma thinner compared with that bfore light exposure.The thickness of ONL decreased by 23.91% and the inner and outer segments appeared disorderly arranged.At the 6th day after light exposure the thickness of ONL is thinner than that at the6th hour,i.e.decreased by 46.6%. At the 14th day after light exposure the thickness of ONL decreased by 42.40%.Flash electroretinogram showed that the amplitudes of a and b wave decreased continuously at the 6th hour and 6th day and unrecovered at the 14th day after light exposure. Conclusion This model might be an ideal one for research on retinal photochemical damage. (Chin J Ocul Fundus Dis,1998,14:101-103)
Objective To investigate the clinical features, treatment methods, and prognostic influence factors of patients with malignant peripheral nerve sheath tumor (MPNST). MethodsA retrospective analysis was conducted on 96 MPNST patients treated between January 1, 2015 and December 31, 2021. There were 46 males and 50 females, aged between 15 and 87 years (mean, 48.2 years). The tumors were located in the trunk in 50 cases, extremities in 39 cases, and head and neck in 7 cases. The maximum tumor diameter was <5 cm in 49 cases, ≥5 cm in 32 cases, with 15 cases missing data. Tumor depth was deep in 77 cases and superficial in 19 cases. The Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) histological grading was G1 in 9 cases, G2 in 12 cases, and G3 in 34 cases, with 41 cases missing data. There were 37 recurrent MPNST cases, 32 cases with neurofibromatosis type 1 (NF1), and 26 cases in stage Ⅳ. Postoperative adjuvant radiotherapy was administered to 25 patients, perioperative chemotherapy to 45 patients, and anlotinib-targeted therapy to 30 patients. R0 resection was achieved in 73 cases. Patients were divided into groups based on the presence or absence of NF1, and baseline data between the two groups were compared. Kaplan-Meier curves were generated to assess disease-free survival (DFS) and overall survival (OS) based on various factors (age, gender, presence of NF1, recurrent MPNST, stage Ⅳ MPNST, FNCLCC grade, R0 resection, tumor location, tumor size, tumor depth, perioperative chemotherapy, postoperative adjuvant radiotherapy, and anlotinib-targeted therapy), and differences between survival curves were analyzed using the Log-Rank test. Multivariate COX proportional hazards regression was used to identify independent prognostic factors for MPNST. Results Patients with NF1 had a significantly higher proportion of superficial tumors and lower FNCLCC grade compared to those without NF1 (P<0.05); no significant difference was found for other variables (P<0.05). Kaplan-Meier analysis showed that recurrent MPNST, stage Ⅳ MPNST, FNCLCC grade, R0 resection, perioperative chemotherapy, and anlotinib-targeted therapy were factors influencing 1-year DFS (P<0.05), while stage Ⅳ MPNST, FNCLCC grade, and perioperative chemotherapy were factors affecting 3-year OS (P<0.05). Multivariate COX proportional hazards regression analysis revealed that recurrent MPNST and high-grade FNCLCC (G3) were independent prognostic factors for 1-year DFS (P<0.05), while stage Ⅳ MPNST, superficial tumor depth, age over 60 years, postoperative adjuvant radiotherapy, and anlotinib-targeted therapy were independent prognostic factors for 3-year OS (P<0.05). Conclusion MPNST patients with NF1 tend to have more superficial tumors and lower FNCLCC grades. FNCLCC grade, R0 resection, and adjuvant therapies, including radiotherapy and anlotinib-targeted therapy, are closely associated with MPNST prognosis. Complete surgical resection should be prioritized in clinical management, along with adjuvant treatments such as radiotherapy and targeted therapy of anlotinib to improve patient outcomes.
Objective To evaluate the pathways for improving the operational efficiency of medical teams, thereby providing micro-level empirical evidence for the refined management and high-quality development of public hospitals. MethodsBased on panel data from nine surgical teams in the Department of Thoracic Surgery at Sichuan Cancer Hospital from 2021 to 2024, this study employed the data envelopment analysis (DEA) with the BCC model to assess static efficiency, including technical efficiency (TE), scale efficiency (SE), and overall efficiency (OE). The Malmquist index was used to analyze the dynamic total factor productivity (TFP) and its decomposition into efficiency change (EC) and technology change (TC). Input indicators were the number of physicians and the number of open beds. Output indicators included the proportion of surgical patients, the proportion of grade Ⅳ surgeries, and the average length of stay (reciprocally transformed for positive orientation). Results The mean OE of all medical teams showed a continuous upward trend, while the mean SE exhibited a “V-shaped” pattern, initially decreasing and then increasing. The most significant growth was observed in mean TE, which was the primary driver of the OE improvement. All medical teams achieved positive TFP growth, with TC values greater than 1.000 across all teams, indicating that technological innovation was the core engine of efficiency enhancement. However, EC showed a divergent trend among the teams. Conclusion Public hospital performance appraisal policies effectively guide technological upgrading of medical teams through indicators such as “proportion of discharged patients undergoing surgery” and “proportion of grade Ⅳ surgeries”. However, issues of hospital resource mismatch and SE differentiation persist. It is necessary to establish specialized operation groups for dynamic resource monitoring and construct a “technological upgrading, scale adaptation, and management innovation” triangular balanced system to achieve a sustainable mechanism for maximizing healthcare resource input-output.