Study on Porosity Defect Detection in Narrow Gap Laser Welding Based on Spectral Diagnosis.

As an advanced connection technology for large thick-walled components, narrow gap laser welding has the advantages of small heat input and high efficiency and quality. However, porosity defects are prone to occur inside the weld due to the complex welding environment. In this study, the influence of the process parameters and pollutants such as water and oil on the porosity defect were explored. The action mechanism of water on the electron temperature and spectral intensity of the laser-induced plasma was analyzed. The results showed that the spectral intensity during narrow gap laser welding was weaker than that of flat plate butt welding. Under the optimal welding process conditions, the electron temperature during narrow gap laser self-fusion welding was calculated as 7413.3 K by the Boltzmann plot method. The electron density was 5.6714 × 1015 cm-3, conforming to the thermodynamic equilibrium state. With six groups of self-fusion welding parameters, only sporadic porosity defects were observed according to the X-ray detection. When there was water on the base metal surface, a large number of dense pores were observed on the weld surface and in the weld through X-ray inspection. Compared with the spectral data obtained under the normal process, the relative light intensity of the spectrometer in the whole band was reduced. The electron temperature decreased to the range of 6900 to 7200 K, while the electron density increased. The spectrum variation during narrow gap laser wire filling welding was basically the same as that of laser self-fusion welding. The porosity defects caused by water and oil pollutants in the laser welding could be effectively identified based on the intensity of the Fe I spectral lines.

Effects of the Two-Dimensional Structure of Trust on Patient Adherence to Medication and Non-pharmaceutical Treatment: A Cross-Sectional Study of Rural Patients With Essential Hypertension in China.

In rural China, treatment adherence of patients with hypertension remains a challenge. Although early research on patient adherence has confirmed the importance of trust in doctors, the relative contribution and influence of the two-dimensional structure of trust on adherence has not been explored. Thus, this study examined the effects of patient trust in primary care physicians' (PCPs) benevolence and ability on medication adherence, dietary management, and physical activity. The data were derived from 2,533 patients at 54 primary health institutions in China (village level) from February 2017 to May 2018. Participants were assessed using the Chinese version of the Wake Forest Physician Trust Scale and the Therapeutic Adherence Subscale for Hypertensive Patients. Other information included region, gender, age, and self-rated health status. The results of multiple linear regression and structural equation modeling confirmed that patient trust in PCPs' benevolence was positively correlated with patient adherence to medication, diet management, and physical activity. Patient trust in PCPs' ability was negatively correlated with adherence to dietary management and physical activity. We concluded that interventions aimed at increasing PCP benevolence have the greatest potential to improve patient adherence to hypertension treatment. Under the country's policy of advocating to improve PCPs' diagnoses and treatment technology, it may be important to cultivate doctors' communication skills, medical ethics, and other benevolent qualities to improve patients' adherence with drug and Non-drug treatments.

Double Similarity Distillation for Semantic Image Segmentation.

The balance between high accuracy and high speed has always been a challenging task in semantic image segmentation. Compact segmentation networks are more widely used in the case of limited resources, while their performances are constrained. In this paper, motivated by the residual learning and global aggregation, we propose a simple yet general and effective knowledge distillation framework called double similarity distillation (DSD) to improve the classification accuracy of all existing compact networks by capturing the similarity knowledge in pixel and category dimensions, respectively. Specifically, we propose a pixel-wise similarity distillation (PSD) module that utilizes residual attention maps to capture more detailed spatial dependencies across multiple layers. Compared with exiting methods, the PSD module greatly reduces the amount of calculation and is easy to expand. Furthermore, considering the differences in characteristics between semantic segmentation task and other computer vision tasks, we propose a category-wise similarity distillation (CSD) module, which can help the compact segmentation network strengthen the global category correlation by constructing the correlation matrix. Combining these two modules, DSD framework has no extra parameters and only a minimal increase in FLOPs. Extensive experiments on four challenging datasets, including Cityscapes, CamVid, ADE20K, and Pascal VOC 2012, show that DSD outperforms current state-of-the-art methods, proving its effectiveness and generality. The code and models will be publicly available.

Effect of trust in primary care physicians on patient satisfaction: a cross-sectional study among patients with hypertension in rural China.

BACKGROUND: In rural areas of China, hypertension is on the rise and it is drawing the Chinese government's attention. The health outcomes of hypertension management can be positively impacted by patient satisfaction with primary care physicians (PCPs), and the influence of patient trust on satisfaction cannot be ignored. This study aimed to analyze the effect of trust in PCPs on patient satisfaction among patients with hypertension in rural China, and the influence of patients' socio-demographic characteristics and hypertension-management-related factors. METHODS: A multi-stage stratified random sampling method was adopted to investigate 2665 patients with hypertension in rural China. Patient trust and satisfaction were measured using the Chinese version of the Wake Forest Physician Trust Scale and the European Task Force on Patient Evaluation of General Practice. Multiple linear regression was used to analyze the factors influencing patient satisfaction, and structural equation modeling was conducted to clarify the relationships among patient trust and patient satisfaction with PCPs. RESULTS: Patients' trust in their PCPs' benevolence had a positive main effect on all three satisfaction dimensions (clinical behavior: ß = 0.940, p <  0.01; continuity and cooperation: ß = 0.910, p <  0.01; and organization of care: ß = 0.879, p <  0.01). Patients' trust in their PCPs' technical competence had a small negative effect on all three satisfaction dimensions (clinical behavior: ß = - 0.077, p <  0.01; continuity and cooperation: ß = - 0.136, p <  0.01; and organization of care: ß = - 0.064, p <  0.01). Patient satisfaction was also associated with region, gender, insurance status, distance from the nearest medical/health-service institution, and number of visits to PCPs in the past year. CONCLUSIONS: Patients focused more on physicians' benevolence than on their technical competence. Hence, medical humanities and communication skills education should be emphasized for PCPs. Regarding region-based and health-insurance-based differences, the inequities between eastern, central, and western provinces, as well as between urban and rural areas, must also be addressed.

Impact of chronic obstructive pulmonary diseases on left ventricular diastolic function in hospitalized elderly patients.

OBJECTIVE: To evaluate the impact of chronic obstructive pulmonary disease (COPD) on left ventricular (LV) diastolic function in hospitalized elderly patients. METHODS: This was a case-control observational study of 148 consecutive hospitalized elderly patients (≥65 years old): 73 subjects without COPD as controls and 75 patients with COPD. Mild-to-moderate COPD was defined as stages 1 and 2, while severe and very severe COPD was defined as stages 3 and 4, according to the Global Initiative for Chronic Obstructive Lung Disease guidelines. Clinical characteristics and echocardiographic parameters were analyzed and compared. RESULTS: Compared with the control group, patients with COPD had a higher frequency of LV diastolic dysfunction and heart failure with preserved ejection fraction. Smoking frequency, frequency of cerebrovascular diseases and diabetes, and serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were higher in the COPD group (all P<0.05). COPD patients showed more abnormalities in diastolic function (E/e': 11.51±2.50 vs 10.42±3.25, P=0.047), but no differences in systolic function and right ventricular function (all P>0.05). Patients with severe/very severe COPD showed no differences in LV diastolic function compared to patients with mild/moderate COPD (P>0.05), but serum NT-proBNP levels were higher in severe/very severe COPD (P<0.05). CONCLUSION: Results suggest that early-stage COPD may have an impact on the LV diastolic function. Severe COPD mainly affected right ventricular function. In hospitalized elderly patients with COPD, LV diastolic dysfunction should be taken into account together with right ventricular function.