Objective:To assess coronary stenosis using 256-slice spiral CT (CTA).Methods:The data of 126 pa-tients diagnosed as coronary heart disease (CHD)using CTA and coronary angiography (CAG)Were retrospectively analyzed.The CAG results for CHD Were regarded as “gold standard”diagnosing CHD.The CTA diagnostic value for CHD and consistency of CAG and CTA diagnosing coronary stenosis Were analyzed.Results:A total of 393 cor-onary segments Were assessed using CTA.According to CAG results for CHD ,the CTA diagnostic accuracy Was 89.3%,sensitivity Was 91.4%,specificity Was 84.8%,negative predictive value Was 82.2% and positive predictive value Was 92.8%;the consistency of CAG and CTA diagnosing coronary stenosis Was good (Kappa value =0.755, P<0.01).Conclusion:The 256-slice spiral CT can diagnosing coronary stenosis,it possesses high sensitivity in di-agnosing vascular stenosis;as a simple and noninvasive examination it can be used as a reliable method for early screening subhealthy population and reexamine of putients With coronary heart disease.

Exosome is a double-layer membrane vesicle secreted by several kinds of cells. Exosome is major way of cell paracrine activity with a wide range of sources and high security feature. This paper reviews recent progress of exosomes in promoting wound healing. Studies have shown that exosomes can be applied to wound treatment by immune regulation, regulating fibroblast activity, promoting angiogenesis, inhibiting scar formation and other mechanisms. Compared with traditional stem cell therapy, exosomes have better applied prospect in clinical practise.

BACKGROUND: As a contour-supporting material, the cartilage has a significant application value in plastic surgery.Since the development of hydrogel scaffolds with sufficient biomechanical strength and high biocompatibility, cell-laden hydrogels have been widely studied for application in cartilage bioengineering. This systematic review summarizes the latest research on engineered cartilage constructed using cell-laden hydrogel scaffolds in plastic surgery. METHODS: A systematic review was performed by searching the PubMed and Web of Science databases using selected keywords and Medical Subject Headings search terms. RESULTS: Forty-two studies were identified based on the search criteria. After full-text screening for inclusion and exclusion criteria, 18 studies were included. Data collected from each study included culturing form, seed cell types and sources, concentration of cells and gels, scaffold materials and bio-printing structures, and biomechanical properties of cartilage constructs. These cell-laden hydrogel scaffolds were reported to show some feasibility of cartilage engineering, including better cell proliferation, enhanced deposition of glycosaminoglycans and collagen type II in the extracellular matrix, and better biomechanical properties close to the natural state. CONCLUSION Cell-laden hydrogels have been widely used in cartilage bioengineering research. Through 3-dimensional (3D) printing, the cell-laden hydrogel can form a bionic contour structure. Extracellular matrix expression was observed in vivo and in vitro, and the elastic modulus was reported to be similar to that of natural cartilage. The future direction of cartilage tissue engineering in plastic surgery involves the use of novel hydrogel materials and more advanced 3D printing technology combined with biochemistry and biomechanical stimulation.

Objective:To investigate the technical route and clinical application effects of correcting abnormal hairline position after rhytidectomy with hair transplantation.Methods:A total of 61 patients in this group were female. The age distribution was 28 to 65 years. Among them, 45 cases underwent forehead (with endoscopy) and mid-face rhytidectomy, 11 cases underwent forehead rhytidectomy (with endoscopy). 5 cases underwent mid-face rhytidectomy. The interval between rhytidectomy and hair transplantation ranged 6 to 79 months, with an average of 18.4 months. The hairline position and morphology of the frontal, temporal and sideburns were redesigned according to aesthetic theory. Hair transplantation was performed to correct the abnormal hairline. When the patients were followed up, the hair survival rate was calculated.The patient’s hairline satisfaction and the degree of concealment of the infratemporal hairline scar were evaluated by patient and a third party attending plastic surgeon, respectively.Results:25 cases underwent hair transplantation of frontotemporal hairline and infratemporal hairline, 23 cases underwent hair transplantation of frontotemporal hairline and 13 cases underwent hair transplantation of infratemporal hairline. All patients were followed up for 12 to 24 months. The hair survival rate of frontotemporal hairline was 94.3%[90.8%(51.1/56.3) to 98.9%(52.5/53.1)]on average.The hair survival rate of the infratemporal hairline, whose incision was inside the temporal, was 93.2%[89.1%(31.1/34.9) to 98.6%(34.4/34.9)]on average. The hair survival rate of the infratemporal hairline, whose incision was on the edge of the temporal hairline, was 81.2%[60.4%(17.2/28.5) to 87.6%(26.8/30.6)]on average. The average satisfaction score of the frontal-temporal hairline for the patients and doctors was 4.5 points and 4.7 points, respectively. The evaluation of the satisfaction of the infratemporal hairline was divided into two parts. The average satisfaction score of the patients with incisions in the hairline was 4.4 points from patients and 4.7 points from doctors. The average satisfaction score of the patients with hairline incisions was 4.0 points for patientsand 4.2 points for doctors. The scar concealment degree of infratemporal hairline scar was 3.7 points for patients and 3.9 points for doctors in average.Conclusions:Correcting abnormal hairline position after rhytidectomy with hair transplantation can achieve satisfactory result. Since the position of the infratemporal hairline and the low hair survival rate on the scar, the effect of scar concealing is average. Replanting hair grafts and improving the design of the rhytidectomy incision are the method to solve this issue.

Objective:To investigate the changes of the zygoma, circumzygomatic sutures, and zygomatic arch in children after trans-sutural distraction osteogenesis (TSDO).Methods:A retrospective analysis was performed on skull CT data of cleft lip and palate patients who underwent TSDO to correct midfacial hypoplasia between 2005 and 2019 in Peking University Third Hospital. The Mimics 20.0 software was used for three-dimensional(3D) model reconstruction to observe the morphological changes of the zygoma, circumzygomatic sutures, and zygomatic arch at the end of the traction period after TSDO. Measurements were taken and analyzed for the distances from mp point to 3D reference planes, zygoma height, zygoma width 1, zygoma width 2, zygoma thickness, zygoma volume, zygomaticomaxillary suture width, zygomaticotemporal suture width, zygomaticofrontal suture width, zygomatic arch length, and distances from zygomatic arch landmarks (tp point, zy point, and ju point) to the 3D reference planes. All data were divided into cleft and non-cleft sides. GraphPad Prism 9.4.1 software was used to analyze the changes before and after TSDO. Measurement data of normal distribution was expressed by ± s and the comparison between groups before and after traction was analyzed by paired t-test. Measurement data of non-normal distribution was expressed by M(IQR) and the comparison between groups before and after traction was analyzed by paired Wilcoxon test. If P<0.05, the difference was statistically significant. Results:A total of 27 patients were included in the study, including 23 males and 4 females, with a mean age of (11.19±2.35) years (5-15 years). Of these patients, 10 had bilateral cleft lip and palate, and 17 had unilateral cleft lip and palate (9 on the left side and 8 on the right side). The average traction period was (40.26±11.43) days. The midfacial depression of the patients was corrected after TSDO, and the zygoma grew forward, downward, and horizontally. The circumzygomatic sutures shifted forward. The zygomatic arch showed forward and downward growth. The measurements of zygoma showed that the mp point moved forward by (7.82±3.95) mm on the cleft side and 4.26(5.72) mm on the non-cleft side with statistical differences ( P<0.05). The mp point moved slightly downward, and outward after TSDO compared to before surgery, and these differences were statistically significant ( P<0.05). After TSDO, the zygoma height, width, and volume were all increased compared to preoperative levels, and these differences were statistically significant ( P<0.05). The width of the lower part of the zygomatic bone showed the most significant change, increasing by 4.33(5.17) mm on the cleft side and (3.42±2.67) mm on the non-cleft side and these differences were statistically significant ( P<0.05). There was no statistically significant difference in the thickness of the zygoma after TSDO compared to before surgery ( P>0.05). The widths of circumzygomatic sutures were all increased after TSDO compared to before surgery, and these differences were statistically significant ( P<0.05). The width of zygomaticofrontal suture showed the greatest increase and the width of zygomaticomaxillary suture showed the smallest increase. The length of the zygomatic arch increased after TSDO compared to before surgery, with an increase of (4.78±2.71) mm on the cleft side and (2.03±1.48) mm on the non-cleft side, and these differences were statistically significant ( P<0.05). There was no statistically significant difference in the position of the tp point after TSDO compared to before surgery ( P>0.05), while the position of the zy point and the ju point moved significantly forward and downward, and these differences were statistically significant ( P<0.05). In the horizontal direction, there was no statistically significant difference in the position of the zy point and ju point after TSDO compared to before surgery ( P>0.05). Conclusion:After TSDO, the zygoma shows three-dimensional growth with significant increases in height, width, and volume. The position of zygoma moves forward, downward, and outward. The circumzygomatic sutures widen due to the distraction force, and the zygomatic arch grows forward and downward, with an increase in length.

Objective:To investigate the clinical effect of autologous fat transplantation combined with hair transplantation in the treatment of hard and/or thin scalp flat scar after burn.Methods:The clinical data of patients with hard and thin scalp scar after burn admitted to the Department of Plastic Surgery of Peking University Third Hospital from January 2017 to December 2022 were retrospectively analyzed. Fat was extracted from the lower abdomen or outer thigh during the operation, and then injected into the scalp scar after standing for 15 minutes, about 0.8 ml/cm 2 under the hard and/or thin scar area, and 0.2-0.4 ml/cm 2 under the thick and soft scar area. Three months after fat transplantation, hair transplantation was performed in the scar bald area, and the transplant density was 25-35 follicular units (FUs)/cm 2 in the hard and thin scar area, and 30-40 FUs /cm 2 in the thick and soft scar area. The Vancouver scar scale (VSS) was used by two third party plastic surgeons to score the hard and/or thin scar areas of the scalp before and 3 months after scalp fat transplantation. The VSS score was expressed as M ( Q1, Q3), and the preoperative and postoperative data were compared by paired sample Wilcoxon signed rank test. During hair transplantation, the density of implanted hair in the hard and/or thin scar area were recorded. The density of living hair at these sites was measured at the last follow-up, and then the survival rate of hair (living hair density/implant hair density ×100%) was calculated. A third party plastic surgeon evaluated the extent to which scalp scars in the hair transplant area were covered, including completely covered, basically covered, partially covered. Patients’ evaluation with the surgical result was divided into very satisfied, satisfied and dissatisfied. Results:A total of 57 patients with scalp scar after burn were included in this group, including 31 males and 26 females, aged 13-47 years old. The time from scalp scarring to treatment was 8-41 years. The area of scalp scar was 17-120 cm 2, with an average of 63.3 cm 2. The fat injection volume of 57 patients was 13-75 ml. The hair transplantation was performed 3-8 months after a single fat filling procedure. The total amount of hair transplantation was 510-3 120 FUs. The total score of postoperative scar VSS was 4(3, 4), significantly lower than the preoperative score of 7(6, 7) ( W=6.70, P < 0.001). The color, thickness, blood vessel distribution and softness were significantly reduced compared with those before surgery ( P< 0.01). All patients were followed up for 12-18 months (mean, 14 months) after hair transplantation. The survival rate of hair in hard and thin scar area was 68.2% (22.7 FUs/cm 2/33.3 FUs/cm 2) to 89.7% (26.1 FUs/cm 2/29.1 FUs/cm 2), with an average of 81.3%. In 32 patients, scalp scars were completely covered. The scalp scar of 25 patients was basically covered. Twenty-nine patients were very satisfied with the result of the operation, and 28 patients were satisfied. Conclusion:The high survival rate of hair transplantation can be obtained by injecting fat under the hard and/or thin scalp scars before hair transplantation, which is an effective method to repair scalp scars.

Objective:To investigate the technical route and clinical application effects of correcting abnormal hairline position after rhytidectomy with hair transplantation.Methods:A total of 61 patients in this group were female. The age distribution was 28 to 65 years. Among them, 45 cases underwent forehead (with endoscopy) and mid-face rhytidectomy, 11 cases underwent forehead rhytidectomy (with endoscopy). 5 cases underwent mid-face rhytidectomy. The interval between rhytidectomy and hair transplantation ranged 6 to 79 months, with an average of 18.4 months. The hairline position and morphology of the frontal, temporal and sideburns were redesigned according to aesthetic theory. Hair transplantation was performed to correct the abnormal hairline. When the patients were followed up, the hair survival rate was calculated.The patient’s hairline satisfaction and the degree of concealment of the infratemporal hairline scar were evaluated by patient and a third party attending plastic surgeon, respectively.Results:25 cases underwent hair transplantation of frontotemporal hairline and infratemporal hairline, 23 cases underwent hair transplantation of frontotemporal hairline and 13 cases underwent hair transplantation of infratemporal hairline. All patients were followed up for 12 to 24 months. The hair survival rate of frontotemporal hairline was 94.3%[90.8%(51.1/56.3) to 98.9%(52.5/53.1)]on average.The hair survival rate of the infratemporal hairline, whose incision was inside the temporal, was 93.2%[89.1%(31.1/34.9) to 98.6%(34.4/34.9)]on average. The hair survival rate of the infratemporal hairline, whose incision was on the edge of the temporal hairline, was 81.2%[60.4%(17.2/28.5) to 87.6%(26.8/30.6)]on average. The average satisfaction score of the frontal-temporal hairline for the patients and doctors was 4.5 points and 4.7 points, respectively. The evaluation of the satisfaction of the infratemporal hairline was divided into two parts. The average satisfaction score of the patients with incisions in the hairline was 4.4 points from patients and 4.7 points from doctors. The average satisfaction score of the patients with hairline incisions was 4.0 points for patientsand 4.2 points for doctors. The scar concealment degree of infratemporal hairline scar was 3.7 points for patients and 3.9 points for doctors in average.Conclusions:Correcting abnormal hairline position after rhytidectomy with hair transplantation can achieve satisfactory result. Since the position of the infratemporal hairline and the low hair survival rate on the scar, the effect of scar concealing is average. Replanting hair grafts and improving the design of the rhytidectomy incision are the method to solve this issue.

Objective:To investigate the changes of the zygoma, circumzygomatic sutures, and zygomatic arch in children after trans-sutural distraction osteogenesis (TSDO).Methods:A retrospective analysis was performed on skull CT data of cleft lip and palate patients who underwent TSDO to correct midfacial hypoplasia between 2005 and 2019 in Peking University Third Hospital. The Mimics 20.0 software was used for three-dimensional(3D) model reconstruction to observe the morphological changes of the zygoma, circumzygomatic sutures, and zygomatic arch at the end of the traction period after TSDO. Measurements were taken and analyzed for the distances from mp point to 3D reference planes, zygoma height, zygoma width 1, zygoma width 2, zygoma thickness, zygoma volume, zygomaticomaxillary suture width, zygomaticotemporal suture width, zygomaticofrontal suture width, zygomatic arch length, and distances from zygomatic arch landmarks (tp point, zy point, and ju point) to the 3D reference planes. All data were divided into cleft and non-cleft sides. GraphPad Prism 9.4.1 software was used to analyze the changes before and after TSDO. Measurement data of normal distribution was expressed by ± s and the comparison between groups before and after traction was analyzed by paired t-test. Measurement data of non-normal distribution was expressed by M(IQR) and the comparison between groups before and after traction was analyzed by paired Wilcoxon test. If P<0.05, the difference was statistically significant. Results:A total of 27 patients were included in the study, including 23 males and 4 females, with a mean age of (11.19±2.35) years (5-15 years). Of these patients, 10 had bilateral cleft lip and palate, and 17 had unilateral cleft lip and palate (9 on the left side and 8 on the right side). The average traction period was (40.26±11.43) days. The midfacial depression of the patients was corrected after TSDO, and the zygoma grew forward, downward, and horizontally. The circumzygomatic sutures shifted forward. The zygomatic arch showed forward and downward growth. The measurements of zygoma showed that the mp point moved forward by (7.82±3.95) mm on the cleft side and 4.26(5.72) mm on the non-cleft side with statistical differences ( P<0.05). The mp point moved slightly downward, and outward after TSDO compared to before surgery, and these differences were statistically significant ( P<0.05). After TSDO, the zygoma height, width, and volume were all increased compared to preoperative levels, and these differences were statistically significant ( P<0.05). The width of the lower part of the zygomatic bone showed the most significant change, increasing by 4.33(5.17) mm on the cleft side and (3.42±2.67) mm on the non-cleft side and these differences were statistically significant ( P<0.05). There was no statistically significant difference in the thickness of the zygoma after TSDO compared to before surgery ( P>0.05). The widths of circumzygomatic sutures were all increased after TSDO compared to before surgery, and these differences were statistically significant ( P<0.05). The width of zygomaticofrontal suture showed the greatest increase and the width of zygomaticomaxillary suture showed the smallest increase. The length of the zygomatic arch increased after TSDO compared to before surgery, with an increase of (4.78±2.71) mm on the cleft side and (2.03±1.48) mm on the non-cleft side, and these differences were statistically significant ( P<0.05). There was no statistically significant difference in the position of the tp point after TSDO compared to before surgery ( P>0.05), while the position of the zy point and the ju point moved significantly forward and downward, and these differences were statistically significant ( P<0.05). In the horizontal direction, there was no statistically significant difference in the position of the zy point and ju point after TSDO compared to before surgery ( P>0.05). Conclusion:After TSDO, the zygoma shows three-dimensional growth with significant increases in height, width, and volume. The position of zygoma moves forward, downward, and outward. The circumzygomatic sutures widen due to the distraction force, and the zygomatic arch grows forward and downward, with an increase in length.

Objective:To investigate the clinical effect of autologous fat transplantation combined with hair transplantation in the treatment of hard and/or thin scalp flat scar after burn.Methods:The clinical data of patients with hard and thin scalp scar after burn admitted to the Department of Plastic Surgery of Peking University Third Hospital from January 2017 to December 2022 were retrospectively analyzed. Fat was extracted from the lower abdomen or outer thigh during the operation, and then injected into the scalp scar after standing for 15 minutes, about 0.8 ml/cm 2 under the hard and/or thin scar area, and 0.2-0.4 ml/cm 2 under the thick and soft scar area. Three months after fat transplantation, hair transplantation was performed in the scar bald area, and the transplant density was 25-35 follicular units (FUs)/cm 2 in the hard and thin scar area, and 30-40 FUs /cm 2 in the thick and soft scar area. The Vancouver scar scale (VSS) was used by two third party plastic surgeons to score the hard and/or thin scar areas of the scalp before and 3 months after scalp fat transplantation. The VSS score was expressed as M ( Q1, Q3), and the preoperative and postoperative data were compared by paired sample Wilcoxon signed rank test. During hair transplantation, the density of implanted hair in the hard and/or thin scar area were recorded. The density of living hair at these sites was measured at the last follow-up, and then the survival rate of hair (living hair density/implant hair density ×100%) was calculated. A third party plastic surgeon evaluated the extent to which scalp scars in the hair transplant area were covered, including completely covered, basically covered, partially covered. Patients’ evaluation with the surgical result was divided into very satisfied, satisfied and dissatisfied. Results:A total of 57 patients with scalp scar after burn were included in this group, including 31 males and 26 females, aged 13-47 years old. The time from scalp scarring to treatment was 8-41 years. The area of scalp scar was 17-120 cm 2, with an average of 63.3 cm 2. The fat injection volume of 57 patients was 13-75 ml. The hair transplantation was performed 3-8 months after a single fat filling procedure. The total amount of hair transplantation was 510-3 120 FUs. The total score of postoperative scar VSS was 4(3, 4), significantly lower than the preoperative score of 7(6, 7) ( W=6.70, P < 0.001). The color, thickness, blood vessel distribution and softness were significantly reduced compared with those before surgery ( P< 0.01). All patients were followed up for 12-18 months (mean, 14 months) after hair transplantation. The survival rate of hair in hard and thin scar area was 68.2% (22.7 FUs/cm 2/33.3 FUs/cm 2) to 89.7% (26.1 FUs/cm 2/29.1 FUs/cm 2), with an average of 81.3%. In 32 patients, scalp scars were completely covered. The scalp scar of 25 patients was basically covered. Twenty-nine patients were very satisfied with the result of the operation, and 28 patients were satisfied. Conclusion:The high survival rate of hair transplantation can be obtained by injecting fat under the hard and/or thin scalp scars before hair transplantation, which is an effective method to repair scalp scars.

Corona virus disease 2019 （COVID-19） has led to more than 500 million cases， including 6.19 million deaths. Mutated strains of SARS-CoV-2 （alpha， beta， gamma， delta and omicron） have successively emerged. Currently the omicron variant is gradually replacing the delta variant， driving a surge of cases in most countries including China， posing a great challenge to the prevention and treatment of COVID-19. In the face of the severe pandemic situation， a large number of non-medical volunteers are fighting on the front lines of the war against the pandemic and are vulnerable to exposure due to lack of professional knowledge. This paper introduces the routine skills training of volunteers and emergency response， aiming to provide behavioral guidance for non-medical volunteers in designated isolation facilities.