Objective To study the method of gray-scale blood flow imaging and image processing in condition of high frequency ultrasound,and the implementation of the system.Methods On the base of research of scattered signals of red blood cells in high frequency ultrasound,20 MHz ultrasound mechanical and linear scanning probe was used to transmit a number of pulses on a scan line.Pulse-echo subtraction method was used to obtain the blood flow information.At the end,simulated blood vascular was used to conduct flow imaging,and the obtained images were analyzed.Results Experiment results showed that clear blood flow images were obtained using this system.The noise from perivascular tissue could be filtered and the signals from blood flow could be enhanced after image processing.Conclusions In the detection of superficial blood vessel,blood flow signals can be obtained even using single pulse emitting via high frequency ultrasound.The blood flow imaging system can be implemented after image processing.

Objective: To report an investigation of a family cluster of coronavirus disease 2019 ( COVID-19 ) in Ningbo, so as to provide reference for the prevention and control measures. Methods: According to the COVID-19 Prevention and Control Program ( fourth version ) , an epidemiological investigation was conducted to collect the demographic information, clinical features and exposure history, to find the close contacts, and to figure out the source and route of infection. Results: Twelve confirmed cases and one asymptomatic case were reported. The attack rate was 16.05%. Among them, five were males and eight were females; the age ranged from 11 to 85 years old, with a median of 39 years old; most had mild symptoms. The incubation period was 2-13 days, with a median of 6.5 days. The first case ( Case 1 ) developed the symptoms on January 22, and had close contact with Zhang, an asymptomatic case, on January 20. Zhang was related to a cluster in the Buddhist assembly on January 19. Case 1, who caused the spread of the epidemic among family members, participated in several family visits and dinners from January 22 to 27 with other 24 families, resulting in six secondary cases and six third-generation cases. There were 54 close contacts except the family members, no infection was found. Conclusion This family cluster may result from the close contact with an asymptomatic case, and then spread within families through having dinners and living together.

OBJECTIVE To observe the long-term efficacy of type-Ⅰ thyroplasty under general anesthesia in the treatment of glottal insufficiency caused by unilateral vocal cord paralysis.METHODS A total of 52 patients with unilateral vocal cord paralysis who underwent type-Ⅰ thyroplasty under general anesthesia at Beijing Tongren Hospital from January 2017 to June 2023 were followed up for more than one year to analyze their efficacy.RESULTS All 52 patients underwent surgery successfully under general anesthesia,and hoarseness improved after operation.Coughing caused by drinking water was reduced or disappeared,and the vocal cords moved inward with improved glottal closure.One year after operation,there was no significant change in the position of the affected vocal cords compared to one week after surgery.The visual analog scale(VAS)scores of all patients with voice disorders decreased sequentially before surgery,one week after surgery,and one year after surgery(80.28±13.49 vs.37.78±19.15 vs.26.26±21.29,P<0.05).The preoperative and one-year postoperative voice perception assessment(GRBAS)showed statistically differences in grade(G),rough(R),breathy(B),and asthenia(A)scores(2.70±0.47 vs.1.09±0.66,2.52±0.54 vs.0.85±0.67,2.85±0.36 vs.0.67±0.65,2.74±0.44 vs.0.61±0.80,P<0.05)except for strain(S).Compared with preoperative results,one-year postoperatively showed a significant decrease in jitter and shimmer(4.61±2.61 vs.3.05±2.37,9.52±3.91 vs.7.11±2.78,P<0.05),and a significant prolongation of maximum phonation time(MPT)[(5.87±2.70)s vs.(14.50±4.30)s,P<0.05].No patients experienced perioperative adverse events.CONCLUSION Type-Ⅰ thyroplasty is an effective surgical method for treatment of vocal cord paralysis.The type-Ⅰ thyroplasty under general anesthesia is safe and effective,which not only significantly improves the symptoms of hoarseness in patients,but also has stable therapeutic effects and can maintain the results for a long time.At the same time,the patient has no pain during the procedure.

OBJECTIVE Exploring the effects of juvenile-onset recurrent respiratory papillomatosis on growth and development,intellectual level,and psychological status.METHODS The clinical data of 40 patients with JORRP who attended Beijing Tongren Hospital of Capital Medical University from January to December 2023(observation group)and 40 healthy adolescents who had medical checkups at the hospital during the same period(control group)were retrospectively analyzed.The body mass index(BMI),Raven's standard progressive matrices(SPM),and the feelings of inadequacy scale(FIS)were used to evaluate the growth and development,intelligence level,and psychological status of the enrolled population.RESULTS BMI was(21.320±3.609)kg/m2 in the observation group and(22.250±2.685)kg/m2 in the control group.The difference between the two groups was not statistically significant(U=668.000,P>0.05).According to the standard conversion of SPM scores,the proportion of observation group with good intelligence level was 5%(2/40),average level was 55%(22/40),below average level was 35%(14/40),and low level was 5%(2/40),while 5%(2/40)of the control group had good intelligence,90%(36/40)had average intelligence,and 5%(2/40)had below average intelligence.The differences in SPM total scores and scores of perceptual discrimination ability in group A,series relationship ability in group D and abstract reasoning ability in group E between the two groups were statistically significant(P<0.05).The intelligence levels of both groups were related to their living areas(|r|>0.3,P<0.05).The difference in FIS scores between the observation group and the control group was statistically significant(86.650±21.680 vs.62.250±9.446,U=270.000,P<0.001).The age of first onset in the observation group was negatively correlated with its sense of inferiority(|r|>0.3,P<0.05).There was no correlation between the number of surgeries in the observation group and their intelligence level and FIS scores(|r|<0.3,P>0.05).CONCLUSION JORRP does not affect the growth and development of patients,but can increase their sense of inferiority to a certain extent,which has a negative impact on their mental health.

Objective    To compare the complications of transcatheter aortic valve replacement (TAVR) between aortic valve stenosis (AS) patients ≥90 years and patients <90 years, and to explore the efficacy and safety of TAVR in AS patients ≥90 years. Methods    Databases including PubMed, The Cochrane Library, EMbase, Medline, CNKI, Wanfang Data and China Biology Medicine disc (CBMdisc) were searched by computer from inception to May 2019. Two reviewers independently screened the literature, extracted the data and evaluated the quality of the included studies. RevMan 5.3 and Stata 15.0 were used for meta-analysis. Results    A total of 12 cohort studies were included, including 60 186 patients (11 350 patients ≥90 years and 48 836 patients <90 years). Meta-analysis showed that compared with the patients <90 years, those ≥90 years had higher all-cause mortality in the hospital (OR=1.51, 95%CI 1.37 to 1.66, P<0.000 01), on postoperative 30 d (OR=1.68, 95%CI 1.50 to 1.89, P<0.000 01) and at postoperative 1 year (OR=1.36, 95%CI 1.25 to 1.48, P<0.000 01), and had higher incidence of stroke (OR=1.31, 95%CI 1.18 to 1.46, P<0.000 01), bleeding events (OR=1.14, 95%CI 1.07 to 1.20, P<0.000 01) and vascular complications (OR=1.31, 95%CI 1.18 to 1.46, P<0.000 01). Conclusion    All-cause mortality and the incidence of some complications after TAVR in AS patients ≥90 years are higher than those in patients <90 years, but this difference is clinically acceptable. Therefore, TAVR treatment is safe and  effective for elderly patients.

Objective: To study the diagnostic accuracy and the distance between the root of maxillary posterior tooth and the maxillary sinus using panoramic radiography and cone beam computer tomography; to provide basic information for clinicians to treat diseases in the maxillary posterior region. Methods: Eighty patients were included in this study. A total of 671 specimens were measured for the distance between the root tip and the maxillary sinus floor in both imaging modalities. Results : The roots that did not contact the sinus floor or contacted but did not project into the sinus cavity showed an agreement of 82% and 70% when using panoramic radiography. Forty-eight percent of the roots that projected into the sinus cavity in panoramic radiography showed protrusion into the sinus with cone beam computer tomography (CBCT). For panoramic radiography and CBCT showing root projections into the sinus cavity, the average distances were 2.19 ± 1.82 mm and 1.47 ± 1.01 mm, respectively. There was a significant difference between the two values (P ＜ 0.05). Conclusion Panoramic radiography is more accurate when roots of maxillary posterior teeth do not contact the sinus floor or contact it. However, it has a lower accuracy rate when the tooth roots protrude into the sinus.

Objective    To systematically review the clinical outcome of patients with new-onset left bundle branch block (LBBB) following transcatheter aortic valve replacement (TAVR). Methods    Electronic search was performed in PubMed, EMbase, Cochrane Library, Web of Science, CNKI, Wanfang and CBM databases to identify studies about the new-onset LBBB after TAVR from inception to March 19, 2022. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies, then, meta-analysis was performed by using Stata 15.0 software. Results    A total of 17 cohort studies were included, covering 9 205 patients, including 2 202 patients with new-onset LBBB and 7 003 without new-onset LBBB after TAVR. The results of meta-analysis showed that patients with new-onset LBBB after TAVR at 30-day (RR=1.65, 95%CI 1.30 to 2.10, P<0.001) and 1-year (RR=1.30, 95%CI 1.16 to 1.45, P<0.001) all-cause mortality was higher than no new-onset LBBB group. One-year cardiovascular mortality was higher in the new-onset LBBB group (RR=1.47, 95%CI 1.21 to 1.79, P<0.001). In the occurrence of 30-day (RR=1.51, 95%CI 1.10 to 2.08, P=0.011) and 1-year (RR=1.34, 95%CI 1.14 to 1.58, P=0.001) rehospitalization rate, 30-day (RR=3.05, 95% CI 1.49 to   6.22, P=0.002) and 1-year (RR=2.15, 95%CI 1.52 to 3.03, P<0.001) pacemaker implantation, the incidence of patients with new-onset LBBB was higher than that of the no new-onset LBBB group. Conclusion    Compared with the patients without LBBB after TAVR, the clinical prognosis of patients with new-onset LBBB after TAVR is poor. In the future, the management and follow-up of the patients with LBBB after TAVR should be further strengthened to improve the prognosis of patients.

Objective    To investigate effectiveness and safety of transcatheter aortic valve replacement in the treatment of aortic regurgitation. Methods     PubMed, EMbase, The Cochrane Library, Web of Science, CNKI, Wanfang Data and VIP were searched from inception to August 2021. According to the criteria of inclusion and exclusion, two reviewers independently screened the literature, extracted the data and evaluated the quality of the included studies. Then, Stata 16.0 software was used for meta-analysis. Subgroup meta-analysis of valve type used and study type was performed. Results    Twenty-five studies (12 cohort studies and 13 single-arm studies) were included with 4 370 patients. Meta-analysis results showed that an incidence of device success was 87% (95%CI 0.81-0.92). The success rate of the new generation valve subgroup was 93% (95%CI 0.89-0.96), and the early generation valve subgroup was 66% (95%CI 0.56-0.75). In addition, the 30-day all-cause mortality was 7% (95%CI 0.05-0.10), the 30-day cardiac mortality was 4% (95%CI 0.01-0.07), the incidence of pacemaker implantation was 10% (95%CI 0.08-0.13), and the incidence of conversion to thoraco-tomy was 2% (95%CI 0.01-0.04). The incidence of moderate or higher paravalvular aortic regurgitation was 6% (95%CI  0.03-0.09). Conclusion     Transcatheter aortic valve replacement for aortic regurgitation is safe and yields good results, but some limitations can not be overcome. Therefore, multicenter randomized controlled trials are needed to confirm our results.

Objective    To systematically review the impact of chronic kidney disease (CKD) at different stages on prognosis of transcatheter aortic valve replacement (TAVR). Methods    Databases including PubMed, the Cochrane Library, EMbase, Web of Science, CNKI, Wanfang and the Chinese Biomedical Literature Database (CBM) were searched by computer to collect cohort studies on impact of different stages of CKD on prognosis of TAVR from inception to July 2020. Two reviewers independently screened literature, extracted data and assessed risk of bias of included studies, and then, meta-analysis was performed by using Stata 15.0 software. Risk of study bias was assessed using the Newcastle-Ottawa Scale (NOS). Results    A total of 17 cohort studies were included with NOS score≥6 points. The results of meta-analysis indicated that: compared with the patients without CKD, all-cause mortality of CKD stage 3 patients at 30 day (RR=1.29, 95%CI 1.22-1.37, P<0.001) and 1 year (RR=1.24, 95%CI 1.19-1.28, P<0.001), all-cause mortality of CKD stage 4 patients at 30 day (RR=2.10, 95%CI 1.90-2.31, P<0.001) and 1 year (RR=1.89, 95%CI 1.62-2.19, P<0.001), and all-cause mortality of CKD stage 5 patients at 30 day (RR=2.22, 95%CI 1.62-2.19, P<0.001) and 1 year (RR=2.24, 95%CI 1.75-2.87, P<0.001) were significantly increased and were associated with the severity of CKD. The occurrence rates of 1-year cardiovascular mortality, postoperative acute kidney injury and bleeding events were all higher in patients with CKD. Conclusion    CKD at stages 3, 4 and 5 is associated with increased all-cause mortality after TAVR, and the higher the stage of CKD is, the higher the risk of all-cause mortality at 30-day and 1-year follow-up is. Due to limited quality and quantity of the included studies, more high-quality studies are required to verify above conclusions.

Objective    To systematically review the efficacy and safety of transfemoral transcatheter aortic valve replacement (TFTAVR) under local anesthesia (LA) and general anesthesia (GA). Methods    Electronic databases including PubMed, EMbase, The Cochrane Library, Web of Science, CNKI, WanFang and CBM were searched to collect randomized controlled trial and cohort studies on clinical outcomes of TFTAVR under LA and GA from inception to September 2020. Two authors independently screened literature, extracted data and assessed the quality of studies, and a meta-analysis was performed by using Stata 16.0 software. Results    A total of 30 studies involving 52 087 patients were included in this study. There were 18 719 patients in the LA group and 33 368 patients in the GA group. The results of meta-analysis showed that the in-hospital all-cause mortality rate [RR=0.65, 95%CI (0.45, 0.94), P=0.021], 30-day all-cause mortality rate [RR=0.73, 95%CI (0.62, 0.86), P<0.001], 30-day stroke [RR=0.82, 95%CI (0.68, 0.98), P=0.025], cardiac arrest [RR=0.50, 95%CI (0.34, 0.73), P<0.001], ICU stay time [RR=−6.86, 95%CI (−12.31, −1.42), P=0.013], and total hospital stay  time [RR=−2.02, 95%CI (−2.59, −1.45), P<0.001] in the LA group were all better than those in the GA group. There was no significant difference in the in-hospital stroke [RR=0.83, 95%CI (0.69, 1.00), P=0.053], in-hospital myocardial infarction (MI) [RR=1.74, 95%CI (0.43, 7.00), P=0.434], or 30-day MI [RR=0.77, 95%CI (0.42, 1.42), P=0.404] between the two groups. Conclusion    LA provides a safe and effective way to induce sedation without intubation, and may be a good alternative to GA for TFTAVR.