Left atrial appendage ( LAA) arises from the left atrial free wall. It is the remnant of the original embryonic LA, distinct from the rest of the left atrium. It has a unique anatomical structure, physiological function, hemodynamic characteristics. LAA has complex surrounding structures, great variability, and close relation with thrombosis. This paper reviews the morphological and functional characteristics of LAA. Familiar with adjacent relationship of LAA and correlation between LAA and thrombus formation has important clinical significance that can reduce the risk of postoperative complications in interventional procedures, the incidence of car?dioembolic stroke, the clinical misdiagnosis on LAA thrombosis.

Objective To improve the clinical and imaging diagnosis of benign fibrous histiocytoma of bone.Methods Imaging findingsin 14 patients with pathologically confirmed benign fibrous histiocytoma of bone were analyzed.X-ray plain film was performed in allpatients,CT scan and MR scan were done in 9 cases and in 5 cases respectively.Results The clinical symptom was mainly pain in the local lesion,soft tissue mass could be felt around the lesion in 2 cases.The single-lesion was 12 cases and multi-lesion was 2 cases.There were 22 lesions in 14 cases.Most lesions localized in long bones,totally were 17 lesions.9 lesions localized in cancellous bone,8 lesions localizedin diaphysis compact substance.X-ray plain film showed centric or eccentric osteolytic destruction,unilocular or multiocular with clearborder or sclerotic border,expansion,pathologic fracture and speckled calcification in some destruction lesions.Soft tissue mass could be seen around the lesion in few cases.CT was better than X-ray plain film in displaying calcification,cyst change,pathologic fracture and soft tissue masses in the destruction portion.MR presented as homogeneous signal on T_1WI and hyper-signal on T_2WI,sometimes was inhomogeneous,speckle-like low-signal and non-signal could be seen in the lesion on T_1WI and T_2WI.Few lesion shows intermixed signal on T_1WI and T_2WI.Conclusion Based on the typical imaging and clinical features,the correct diagnosis of benign fibrous histiocytoma can be made in most cases.

Objective To investigate the sleep condition and its influence factors in old patients with hypertension. Methods A total of 100 old patients with hypertension were investigated by Pitts-burgh sleep quality index (PSQI) and serf-designed questionnaire of influence factors. Results 76 per-cents of the old patients with hypertension had sleep disorders.The total score of PSQI,sleep quality,time take to fall asleep,hours of sleep,sleep effficiency,sleep disorders,hypnotic drugs and every score of daytime dysfunction were significantly higher than domestic norm(P<0.01).Surroundings(strange circumstances or noisiness), physio-pathology (disease distress or high frequency of going to toilet during nighttime),psycho-logical situations(the fear to the disease or worrying about medical fees) and drags(use of diuretics or the adverse effects of some antihypertensive agents) were the important factors affecting sleep quality. Con-clusions Old patients with hypertension have poor sleep quality,which relates with multiple factors.Valid nursing interventions should be adopted in order to control the various factors which affect sleep quality to improve patients' sleep quality.

OBJECTIVE To explore an effective cleaning method to improve the quality of sterilization,in order to control infections in the hospitals. METHODS To adopt orthogonal experimental forms of L_9(3~4) and take water temperature,cleaning agent type and cleaning method as experimental factors,in this way to investigate decontamination method for surgical instruments,using TOSI indicator cards and Browne STF load device to test the effectiveness of cleaning results. RESULTS It showed that by KQ-4200SY medical digital full-automatic ultrasonic cleaner with washing water at 33-35℃ an optimal cleaning result would be obtained. CONCLUSIONS It is practical to clean surgical instruments by KQ-4200SY medical digital full-automatic ultrasonic cleaner,and by TOSI indicator cards and Browne STF used as test method.

Objective To analyze the displacement of titanium clips for tumor bed localization after breast-conserving surgery for breast cancer and its influential factors.Methods A retrospective analysis was performed on the cone-beam computed tomography (CT) images of 14 patients with breast cancer who received radiotherapy after breast-conserving surgery from April to October,2016.The relative position of the chest wall and the errors of the titanium clips in radiotherapy were measured.A Pearson correlation analysis was used to analyze the correlation of the displacement of titanium clips with the relative position of titanium clips,the breast volume,the vertical distance between the titanium clips and the tangential line of the chest wall,and the maximum thickness of the breast.Results The system errors of the chest wall in left-right,superior-inferior,and anterior-posterior directions were 4.42,3.44,and 5.13 mm,respectively,and the random errors were 3.55,3.07,and 4.54 mm,respectively.The titanium clips had a large displacement relative to the chest wall,mainly in the left-right direction.The maximum system error was 4.39 mm and the random error was 2.42 mm.The displacement of titanium clips was not significantly correlated with the breast volume and the maximum thickness of the breast (P>0.05).However,the relative position of titanium clips in superior-inferior direction was significantly correlated with the displacement of the lowest,the most lateral,the most anterior,and the most posterior titanium clips (P<0.05).As to the uppermost clips,there was a significant difference in displacement between the clips close to the chest wall and the clips far from the chest wall (P=0.02).Conclusions Due to large setup error and displacement of titanium clips during radiotherapy,simultaneous integrated boost is not suitable for patients with breast cancer who are immobilized by vacuum cushion and received radiotherapy.The unstable immobilization may be the major influential factor for the displacement of titanium clips.

AIM: To investigate the application of two-stage estimation (TSE) on adjustment for treatment switch in oncology trials. METHODS: The theory and implementation of TSE method was described, and was applied to adjust the data from a two-arm randomized controlled trial of anti-tumor drugs. The changes of survival curves and hazard ratio of two groups after adjustment for cross-over were evaluated. In addition, the results of two-stage estimation and rank preserving structural failure time model (RPSFT) were compared. RESULTS: After adjustment for cross-over using TSE methods, the results showed that the median survival time of control group was shorter than the original one, and the hazard ratio was lower than the observed value. Moreover, TSE method showed similar results to rank preserving structural failure time model. CONCLUSION: The TSE method is relatively simple to use, reliable and has a good practice property in cross-over analysis of oncology trials. At the same time, it is necessary to pay attention to its application scopes.

【Objective】 To analyze the hepatitis B virus (HBV) infection data of blood donors from 18 domestic blood stations, so as to investigate the HBV infection situation of blood donors. 【Methods】 The positive rate of HBV and its distribution characteristics of regions, the percentage of HBsAg+ ELISA in first-time vs repeated blood donors, and the percentage of HBsAg-/HBV DNA+ blood donors of 18 domestic blood stations during 2017 to 2020 were collected from the Working Platform for Practice Comparison of Blood Centers, and the HBV infection among blood donors were statistically analyzed. 【Results】 From 2017 to 2020, the positive rate of HBV in blood donors among 18 domestic blood stations was 13.48/10 000-144.02/10 000, with the average HBV positive rate in eastern, central and western region at 26.14/10 000, 51.98/10 000 and 41.00/10 000, respectively. The HBsAg+ rate by ELISA among first-time and repeated blood donors was 14.55/10 000-305.39/10 000 vs 1.04/10 000-87.43/10 000 The HBsAg-/HBV DNA+ yield was 1.80/10 000-35.31/10 000. 【Conclusion】 The distribution of HBV infection in blood donors has regional characteristics, and HBV prevalence was low in repeated blood donors. HBsAg ELISA combined with HBV DNA detection can better ensure blood safety.

【Objective】 To study the annual financial expenditure in blood stations with different scales, and to establish the regression equation between blood collection units and total expenditure. 【Methods】 The annual total expenditure, the per capita cost of serving population, as well as the collection units of whole blood and apheresis platelet of 24 blood stations were collected. The financial expenditure required for collecting 10 000U blood was calculated.The statistical analysis was carried out with SPSS statistical software. 【Results】 From 2017 to 2020, the total annual financial expenditure of 24 blood stations showed an upward trend. The total expenditure among blood stations was different. The per capita cost of servicing population in the areas where the 24 blood stations were located had been increasing year by year. The 24 blood stations were divided into two grades according to the blood collection volume as 50 000 U, and the relationship equation between the blood collection volume and the annual total expenditure had been established. After testing, each equation was effective(P<0.05); There was no difference in the financial expenditure required for collecting 10 000U blood among blood stations with different scales. 【Conclusion】 From 2017 to 2020, the blood stations with an annual collection volume more than 50 000 U demonstrated a higher financial expenditure and the per capita cost of serving population than those <50 000 U. The blood collection volume of blood stations is significantly correlated with the annual total expenditure and the per capita cost of serving population.

【Objective】 To evaluate and analyze the impact of COVID-19 epidemic on inventory of red blood cells (RBCs)in local and municipal blood stations in China, and to provide reference for the management of public health emergencies. 【Methods】 Relevant data from 2018 to 2021 were collected, and the differences in the volume of qualified RBCs, the usage efficiency of inventory RBCs, the average daily distribution of RBCs,the blood distribution rate of RBCs prepared by 400 mL whole blood, the difference in the average storage days of RBCs at the time of distribution, the average daily inventory of RBCs and the time of the average daily inventory of RBCs to maintain the distribution in 24 local and municipal blood stations in China during the COVID-19 epidemic and non-epidemic periods were retrospectively analyzed. 【Results】 Compared with non-epidemic periods, the volume of qualified RBCs [(117 525.979 ±52 203.175)U] and the average daily distribution of RBCs [( 156. 468 ± 70. 186) U ] increased significantly, but the usage efficiency of inventory RBCs decreased(97.24%±0.51%) significantly (P<0.05).There was no significant difference in the blood distribution rate of RBCs prepared by 400 mL whole blood(73.88%±20.30%), the average storage days of RBCs distribution(13.040 ±3.486), the average daily stock quantity of RBCs[(2 280.542 ±1 446.538) U ] and the time of the average daily inventory of RBCs to maintain the distribution[(15.062 ±7.453) d] (P>0.5). 【Conclusion】 During the COVID-19 epidemic, the inventory management of RBCs operated well, the overall inventory remained relatively stable, the stock composition and storage period showed no significant change.

【Objective】 To analyze the basic characteristics of whole blood donors from blood stations before and after the outbreak of COVID-19. 【Methods】 After excluding invalid data, data related to the basic characteristics of whole blood donors collected from 26 blood stations in China during 2018 to 2021 were statistically analyzed, including the trend of total whole blood donors, the number of repeated blood donors, the frequency of blood donation, the average age of donors and the recruitment of first-time blood donors. 【Results】 Affected by the epidemic, 8 out of 14 indicators were with large variations, accounting for 57%. The overall growth rate of total whole blood donors during the epidemic was higher than before the epidemic (P<0.05).The number of repeated blood donors has shown an increased trend, with a higher number during the epidemic than before (P<0.05). The frequency of blood donation was lower during the epidemic than before(P<0.05).Average ages of blood donors and female blood donors fluctuated widely during the epidemic, both higher than those before the epidemic(P<0.05).The donation rate of first-time blood donors <25 years old and ≥25 years old varied widely and irregularly during the epidemic (both P<0.05). The percentage of first-time blood donors fluctuated irregularly during the epidemic, with overall percentage lower than that before the epidemic(P<0.05). 【Conclusion】 Whole blood donors from 26 blood stations increased after the outbreak of COVID-19, and some indicators in certain areas showed significant fluctuations during the epidemic.