It is a technological difficulty to acquire data from ultrasound with ultra-band in the study of microwave-induced thermoacoustic tomography. A high-speed data acquisition system for the ultrasonic signal with a frequency fewer than 500 MHz is designed in the paper. The result obtained demonstrates that the system holds good for microwave-induced thermoacoustic tomography.

Objective:Before the radiotherapy was performed, patients with pelvic tumors were analyzed for the consistency of bladder filling in the three steps of " Immobilization" , " CT Simulation" and " X-ray Simulation" .Methods:In 2014, 105 patients (68 cases of cervical cancer, 32 cases of rectal cancer, 3 cases of vaginal cancer and 2 cases of prostate cancer) with pelvic tumor radiotherapy were randomly assigned to monitor bladder urine volume to a target urine volume of 400 ml. First, patient were exhorted to empty the bladder, and the bladder volume meter BVI 9400 was used to measure the urine volume of the patient after emptying of the bladder. The patient immediately drank about 540 ml of water and suppressed urine, measurements were taken every 0.5 h. At the same time, when the patient complained of " urgency of urine" , bladder urine volume would be measured again and the time would also be recorded. Every other half an hour (emptying, 0.5 h after emptying, 1.0 h after emptying), when complaining of " urgency of urine" , when actually performing urine volume and time were described as: U 0 and t 0, U 0.5 and t 0.5, U 1.0 and t 1.0, U t and t, U T and T. Results:There was a statistically significant difference in gender and age, and women had stronger ability to urinate than men U 1.0( P=0.003), young people had stronger ability to urinate than middle-aged U 1.0( P=0.002). In the three-step comparison, there was no statistically difference between 1 hour after emptying urine volume U 1.0( P=0.177) and the actually performing urine volume U T ( P=0.052). And the final urine volume was concentrated at 298-526 ml. After the patient emptied the urine volume and complained of " urgency of urine" , the time slot was t=(75.2±49.9) min, with the urine volume of U t=(331.2±140.3) ml. And there was no statistically difference between U t and U T ( P=0.198) at X-ray Simulation. Conclusions:The patient emptied the bladder and immediately drank 540 ml of water. After 1 hour of suppressing urine, he complained of " urgency of urine" and achieved the target urine volume (400 ml). At this time, the bladder urine volume U 1.0 was consistency in the immobilization, CT Simulation, and X-ray Simulation.

OBJECTIVETo establish the automatic X-ray cephalometric analysis system to simplify cephalometric steps and to provide a convenient and reliable method for cephalometric analysis.

METHODSThe system which was programmed by visual-c language, and graphics and image processing techniques and artificial intelligence were used. The techniques related to computer digital image processing and pattern recognition such as Median filtering, Histogram equalization, Laplacian and Canny edge detection were introduced. It could automatically outline the contour lines of the hard and soft tissues by establishing the templates of the variable anatomical structures.

RESULTSThe following functions were established: (1) automatically outlining the contour lines of the soft tissues. (2) automatically recognizing, measuring and analysing the landmarks of soft tissues. (3) automatically recognizing porion, sella and the landmarks of the mandible. (4) automatically building the contour lines of the hard tissues. In brief, the system used the more advanced methods, calculated more precisely and saved more time and energy than other systems.

CONCLUSIONThe system is a more convenient and precise tool in cephalometry.

Cephalometry ; methods ; Humans ; Image Processing, Computer-Assisted ; Jaw ; anatomy & histology ; diagnostic imaging ; Orthodontics ; methods ; Radiography ; Sensitivity and Specificity

Objective To explore the characteristic manifestations of breast malignant isodense masses using mammography. Methods 121 breast isodense masses with pathological confirmations were collected.Compared indicators with pathological findings were the tumor size,shape,edge,structure changes around the mass,axillary lymph nodes,skin changes,nipple changes,suspi-cious malignant calcification.χ2 test and Logistic regression analysis were used to evaluate the diagnostic values of each indicator.Re-sults In the 121 isodense masses,73 were benign,48 were malignant tumors.According to χ2 test analysis,factors impacted the nature of mass including:tumor morphology (χ2 =14.376,P =0.002),tumor edge (χ2 = 21.555,P =0.000),structure twisted surrounding the mass (χ2 =26.939,P =0.000),axillary lymph nodes (χ2 =1 6.285,P =0.000),skin thickening (χ2 =4.698,P =0.030).According to multivariate binary Logistic regression analysis,risk factors of the Logistic regression model included:edge infiltrating of mass (P =0.014),structure twisted surrounding the mass (P =0.003),axillary lymph nodes (P =0.026).Conclusion The characteristic manifestations of breast malignant isodense masses include edge infiltrating,structure twisted surrounding the mass,axillary lymph nodes.These manifestations are of great significance in differential diagnosis of breast isodense masses.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has a clinical manifestation of hypoxic respiratory failure and acute respiratory distress syndrome. However, COVID-19 still lacks of effective clinical treatments so far. As a promising potential treatment against COVID-19, stem cell therapy raised recently and had attracted much attention. Here we review the mechanisms of mesenchymal stem cell-based treatments against COVID-19, and provide potential cues for the effective control of COVID-19 in the future. METHODS: Literature is obtained from databases PubMed and Web of Science. Key words were chosen for COVID- 19, acute respiratory syndrome coronavirus 2, mesenchymal stem cells, stem cell therapy, and therapeutic mechanism. Then we summarize and critically analyze the relevant articles retrieved. RESULTS: Mesenchymal stem cell therapy is a potential effective treatment against COVID-19. Its therapeutic efficacy is mainly reflected in reducing severe pulmonary inflammation, reducing lung injury, improving pulmonary function, protecting and repairing lung tissue of the patients. Possible therapeutic mechanisms might include immunoregulation, antiinflammatory effect, tissue regeneration, anti-apoptosis effect, antiviral, and antibacterial effect, MSC - EVs, and so on. CONCLUSION Mesenchymal stem cells can effectively treat COVID-19 through immunoregulation, anti-inflammatory, tissue regeneration, anti-apoptosis, anti-virus and antibacterial, MSC - EVs, and other ways. Systematically elucidating the mechanisms of mesenchymal stem cell-based treatments for COVID-19 will provide novel insights into the follow-up research and development of new therapeutic strategies in next step.