Objective:To evaluate the role of high-resolution computer tomography (HRCT) with multiplanar reformation (MPR) in the differential diagnosis of renal papillary calcification and renal calculi.Methods:Retrospective study was used upon collecting the clinical data of pilots who were suspected of renal calculi by HRCT and diagnosed by ureteroscopy in the Air Force Medical Center from June of 2017 to October of 2021. MPR was used to analyze and measure the acquired images. According to the results of ureteroscopy, they were divided into renal papillary calcification group and renal calculi group. The sizes (transverse diameter, longitudinal diameter, and difference between transverse and longitudinal diameters) and CT values of the lesions were compared between 2 groups and analyzed.Results:Eighteen pilots were included. A total of 33 lesions were detected, including 8 renal papillary calcification and 25 renal calculi. ①The transverse diameter of renal papillary calcification lesions was (2.93±0.42) mm, the longitudinal diameter was (3.00±0.41) mm, and the difference between transverse and longitudinal diameters was (0.12±0.81) mm; the transverse diameter of renal calculi lesions was (4.47±2.18) mm, the longitudinal diameter was (4.01±1.49) mm, and difference between longitudinal and transverse diameters was (0.89±0.96) mm. The differences between 2 groups were statistically significant ( t=3.78, 2.93, 3.77, P=0.001, 0.007, 0.001). ②The CT values of renal papillary calcification and renal calculi was (270.87±86.95) HU and (610.74±347.03) HU, respectively, with a statistically significant difference ( t=4.32, P<0.001). ③The area under the receiver operating characteristic curve of the transverse diameter, longitudinal diameter and difference between longitudinal and transverse diameters, as well as CT values, was 0.793, 0.701, 0.894, 0.788, respectively; the critical value of the difference between longitudinal and transverse diameters was 0.225 mm, and the Youden′s J statistic was 0.745. Its sensitivity and specificity was 87.0% and 87.5% respectively. Conclusions:HRCT combined with MPR is helpful to differentiate renal papillary calcification from renal calculi. The diagnostic accuracy is the highest on differentiating the difference between the longitudinal and transverse diameter of the lesion.

Objective:To evaluate the role of high-resolution computer tomography (HRCT) with multiplanar reformation (MPR) in the differential diagnosis of renal papillary calcification and renal calculi.Methods:Retrospective study was used upon collecting the clinical data of pilots who were suspected of renal calculi by HRCT and diagnosed by ureteroscopy in the Air Force Medical Center from June of 2017 to October of 2021. MPR was used to analyze and measure the acquired images. According to the results of ureteroscopy, they were divided into renal papillary calcification group and renal calculi group. The sizes (transverse diameter, longitudinal diameter, and difference between transverse and longitudinal diameters) and CT values of the lesions were compared between 2 groups and analyzed.Results:Eighteen pilots were included. A total of 33 lesions were detected, including 8 renal papillary calcification and 25 renal calculi. ①The transverse diameter of renal papillary calcification lesions was (2.93±0.42) mm, the longitudinal diameter was (3.00±0.41) mm, and the difference between transverse and longitudinal diameters was (0.12±0.81) mm; the transverse diameter of renal calculi lesions was (4.47±2.18) mm, the longitudinal diameter was (4.01±1.49) mm, and difference between longitudinal and transverse diameters was (0.89±0.96) mm. The differences between 2 groups were statistically significant ( t=3.78, 2.93, 3.77, P=0.001, 0.007, 0.001). ②The CT values of renal papillary calcification and renal calculi was (270.87±86.95) HU and (610.74±347.03) HU, respectively, with a statistically significant difference ( t=4.32, P<0.001). ③The area under the receiver operating characteristic curve of the transverse diameter, longitudinal diameter and difference between longitudinal and transverse diameters, as well as CT values, was 0.793, 0.701, 0.894, 0.788, respectively; the critical value of the difference between longitudinal and transverse diameters was 0.225 mm, and the Youden′s J statistic was 0.745. Its sensitivity and specificity was 87.0% and 87.5% respectively. Conclusions:HRCT combined with MPR is helpful to differentiate renal papillary calcification from renal calculi. The diagnostic accuracy is the highest on differentiating the difference between the longitudinal and transverse diameter of the lesion.

Objective: To investigate the antibacterial property and biological activity of Ti dental implant with antimicrobial peptide Pac-525 coatings, and to study the effect of peptide Pac-525 coatings on Porphyromonas gingivalis's antibacterial performance and osteoblast proliferation and adhesion. Methods: After ultrasonic micro arc oxidation, alkali treatment and silane treatment, forty-five pure titanium specimens were exposed to antibacterial peptide Pac-525 in different concentration (0.25, 0.50, 0.75 g/L). The titanium specimens in the control group were only treated with ultrasonic micro arc oxidation, alkali treatment and silane treatment. The morphologies of coatings were observed by scanning electron microscope (SEM), and the element changes were detected by energy spectrum analyzer. Orange acridine-ethidium bromide double staining was used to detect the average percentage of live bacteria and biofilm thickness, after the specimens in each group and Porphyromonas gingivalis were co-cultured for 72 hours. Cell counting Kit-8 method and immunofluorescence staining were used to test the proliferation of osteoblasts, the number and growth morphologies of adherent cells, respectively. Results: SEM and energy spectrum analysis showed that the Pac-525 particles loaded on the surface of the coating, and the C and N elements in the Pac-525 coating group were significantly more than those in the control group. The average percentage of living bacteria in the control group, 0.25, 0.50 and 0.75 g/L antimicrobial peptides were 0.58%, 0.45%, 0.34% and 0.28%, respectively, and the difference between each group was statistically significant (P<0.05). The biofilm thickness of Porphyromonas gingivalis in 0.50 and 0.75 g/L antibacterial peptide group were (98.3±1.2) and (94.5±2.5) μm respectively, which were significantly less than those in control group and 0.25 g/L antibacterial peptide group [(117.6±1.5) and (118.0±1.3) μm] (P<0.05), respectively. The number of bone cell adhesion and proliferation of all antimicrobial peptides were significantly greater than those in the control group (P<0.05), and the cells stretched better. Conclusions The antibacterial peptide coating of titanium implants could inhibit the formation of bacterial biofilm. It had good antibacterial properties and could promote the adhesion and proliferation of osteoblasts.