SCTV-UNet: a COVID-19 CT segmentation network based on attention mechanism.

The global outbreak of COVID-19 has become an important research topic in healthcare since 2019. RT-PCR is the main method for detecting COVID-19, but the long detection time is a problem. Therefore, the pathological study of COVID-19 with CT image is an important supplement to RT-RCT. The current TVLoss-based segmentation promotes the connectivity of diseased areas. However, normal pixels between some adjacent diseased areas are wrongly identified as diseased pixels. In addition, the proportion of diseased pixels in CT images is small, and the traditional BCE-based U-shaped network only focuses on the whole CT without diseased pixels, which leads to blurry border and low contrast in the predicted result. In this way, this paper proposes a SCTV-UNet to solve these problems. By combining spatial and channel attentions on the encoder, more visual layer information are obtained to recognize the normal pixels between adjacent diseased areas. By using the composite function DTVLoss that focuses on the pixels in the diseased area, the problem of blurry boundary and low contrast caused by the use of BCE in traditional U-shaped networks is solved. The experiment shows that the segmentation effect of the proposed SCTV-UNet has significantly improved by comparing with the SOTA COVID-19 segmentation networks, and can play an important role in the detection and research of clinical COVID-19.

Changes of Volume Parameters in the Treatment of Graves Ophthalmopathy by Endoscopic Transethmoidal Decompression of the Orbital Inner Wall Combined with Fat Decompression.

Objective: To observe the orbital volume changes and the analysis of surgical effect of Graves orbitopathy (GO) after endoscopic medial wall decompression combined with muscle cone fat. Methods: Twenty-two patients (30 eyes) with Graves orbital disease who visited the Department of Ophthalmology of Ningbo Medical Center from December 2019 to September 2021 were retrospectively collected. All patients were diagnosed as nonorganic active stage before operation, and all of them received endoscopic transethmoidal decompression of the medial orbital wall combined with intramuscular orbital fat decompression due to decreased vision, visual field defect or color vision disorder, and concomitant proptosis. Regular follow-up after operation. The curative effect is judged according to the degree of improvement of visual acuity, color vision, degree of correction of exophthalmos, diplopia, and other complications at 9 months after operation. Orbital CT combined with computer aided measurement software (Mimics 21) was used to measure the changes of orbital volume before and after exophthalmos surgery. The relationship between the value and eyeball regression is analyzed. Results: Preoperative exophthalmos ranged from 17.4 mm to 27.6 mm, with an average of (22.08 ± 2.86) mm. The postoperative exophthalmos was 14-25 mm, with an average of (19.52 ± 3.10) mm. Among them, 7 eyes (23.3%) had exophthalmos regression less than 1 mm, 6 eyes (20%) had a regression of 1-2 mm, 7 eyes (23.3%) had a regression of 2-3 mm, 5 eyes (16.7%) had a regression of 3-4 mm, and 5 eyes (16.7%) had a regression of 4-5.3 mm. The exophthalmos after operation was significantly lower than that before operation, and the difference was statistically significant (t = 9.909, P < 0.05). The preoperative orbital volume was 18.6 cm3-25.3 cm3 with an average of (22.39 ± 1.91) cm3. The postoperative orbital volume was 19.8 cm3-26.6 cm3, with an average of (23.89 ± 1.90) cm3.The orbital volume change range is 0.1 cm3-3.8 cm3, and the average orbital volume change is (1.51 ± 1.00) cm3. Compared with preoperative orbital volume, the difference was statistically significant (t = -8.074, P < 0.05). Conclusion: Endoscopic decompression of the medial orbital wall through the ethmoid approach combined with decompression of the orbital fat within the muscle cone can effectively correct the exophthalmos while decompressing the orbital apex, and it is minimally invasive and has no facial scars. It has the advantages of extremely low incidence of postoperative diplopia and eye shift. There is a significant correlation between orbital volume changes and the regression of exophthalmos, which can provide reference for clinical guidance of surgical methods and prediction of surgical results.

Intelligent Privacy Protection of End User in Long Distance Education

Long distance education is an important part during the COVID-19 age. An intelligent privacy protection with higher effect for the end users is an urgent problem in long distance education. In view of the risk of privacy disclosure of location, social network and trajectory of end users in the education system, this paper deletes the location information in the location set to protect the privacy of end user by providing the anonymous set to location. Firstly, this paper divides the privacy level of social networks by weighted sensitivity, and collects the anonymous set in social networks according to the level;Secondly, after the best anonymous set is generated by taking the data utility loss function as the standard, it was split to get an anonymous graph to hide the social network information;Finally, the trajectory anonymous set is constructed to hide the user trajectory with the l-difference privacy protection algorithm. Experiments show that the algorithm presented in this paper is superior to other algorithms no matter how many anonymous numbers there are, and the gap between relative anonymity levels is as large as 5.1 and 6.7. In addition, when the privacy protection intensity is 8, the trajectory loss rate presented in this paper tends to be stable, ranging from 0.005 to 0.007, all of which are less than 0.01. Meanwhile, its clustering effect is good. Therefore, the proportion of insecure anonymous sets in the algorithm in this paper is small, the trajectory privacy protection effect is good, and the location, social network and trajectory privacy of distance education end users are effectively protected.