Objective To investigate characteristics and value of prenatal ultrasound in diagnosing persistent left and absent right superior vena cava.Methods Ultrasonic data of 8 fetuses with persistent left and absent right superior vena cava were retrospectively analyzed.Ultrasonic findings of persistent left and absent right superior vena cava and other complicated anomalies were observed,and the outcomes were followed up.Results The ultrasonic characteristics of persistent left and absent right superior vena cava included a vessel which could be seen on the left of pulmonary artery on three vessel-trachea view draining into the dilated coronary sinus,and right superior vena cava was absent.With combined spatio-temporal image correlation (STIC) and high definition flow (HDF) technique,the spatial relationship of the left superior vena cava,aorta and pulmonary artery could be observed.Dilated coronary sinus was found in all 8 fetuses,other congenital heart defects were detected in 5 fetuses,and extracardiac anomaly was found in 1 fetus.Conclusion Persistent left and absent right superior vena cava and complicated anomalies can be accurately diagnosed with prenatal ultrasound.Dilated coronary sinus is an important clue for prenatal ultrasonic diagnosis.

Objective:To compare the difference of low-level assisted ventilation and T-piece method on respiratory mechanics of patients with invasive mechanical ventilation during spontaneous breathing trial (SBT) within 3 days before extubation.Methods:A retrospective observational study was conducted. Twenty-five patients with difficulty in weaning or delayed weaning from invasive mechanical ventilation who were admitted to department of critical care medicine of the First Affiliated Hospital of Guangzhou Medical University from December 2018 to June 2020, and were in stable condition and entered the weaning stage after more than 72 hours of invasive mechanical ventilation were studied. A total of 119 cases of respiratory mechanical indexes were collected, which were divided into the low-level assisted ventilation group and the T-piece group according to the ventilator method and parameters used during the data collection. The different ventilation modes related respiratory mechanics indexes such as the esophageal pressure (Pes), the gastric pressure (Pga), the transdiaphragmatic pressure (Pdi), the maximum Pdi (Pdimax), Pdi/Pdimax ratio, the esophageal pressure-time product (PTPes), the gastric pressure-time product (PTPga), the transdiaphragmatic pressure-time product (PTPdi), the diaphragmatic electromyography (EMGdi), the maximum diaphragmatic electromyography (EMGdimax), PTPdi/PTPes ratio, Pes/Pdi ratio, the inspiratory time (Ti), the expiratory time (Te) and the total time respiratory cycle (Ttot) at the end of monitoring were recorded and compared between the two groups.Results:Compared with the T-piece group, Pes, PTPes, PTPdi/PTPes ratio, Pes/Pdi ratio and Te were higher in low-level assisted ventilation group [Pes (cmH 2O, 1 cmH 2O = 0.098 kPa): 2.84 (-1.80, 5.83) vs. -0.94 (-8.50, 2.06), PTPes (cmH 2O·s·min -1): 1.87 (-2.50, 5.93) vs. -0.95 (-9.71, 2.56), PTPdi/PTPes ratio: 0.07 (-1.74, 1.65) vs. -1.82 (-4.15, -1.25), Pes/Pdi ratio: 0.17 (-0.43, 0.64) vs. -0.47 (-0.65, -0.11), Te (s): 1.65 (1.36, 2.18) vs. 1.33 (1.05, 1.75), all P < 0.05], there were no significant differences in Pga, Pdi, Pdimax, Pdi/Pdimax ratio, PTPga, PTPdi, EMGdi, EMGdimax, Ti and Ttot between the T-piece group and the low-level assisted pressure ventilation group [Pga (cmH 2O): 6.96 (3.54,7.60) vs. 7.74 (4.37, 11.30), Pdi (cmH 2O): 9.24 (4.58, 17.31) vs. 6.18 (2.98, 11.96), Pdimax (cmH 2O): 47.20 (20.60, 52.30) vs. 29.95 (21.50, 47.20), Pdi/Pdimax ratio: 0.25 (0.01, 0.34) vs. 0.25 (0.12, 0.41), PTPga (cmH 2O·s·min -1): 7.20 (2.54, 9.97) vs. 7.97 (5.74, 13.07), PTPdi (cmH 2O·s·min -1): 12.15 (2.95, 19.86) vs. 6.87 (2.50, 12.63), EMGdi (μV): 0.05 (0.03, 0.07) vs. 0.04 (0.02, 0.06), EMGdimax (μV): 0.07 (0.05, 0.09) vs. 0.07 (0.04, 0.09), Ti (s): 1.20 (0.95, 1.33) vs. 1.07 (0.95, 1.33), Ttot (s): 2.59 (2.22, 3.09) vs. 2.77 (2.35, 3.24), all P > 0.05]. Conclusions:When mechanically ventilated patients undergo SBT, the use of T-piece method increases the work of breathing compared with low-level assisted ventilation method. Therefore, long-term use of T-piece should be avoided during SBT.

【Objective】 To retrospectively analyze the unqualified blood screening results of voluntary blood donors in Guangzhou area during 2016~2020, and analyze various factors that affect the blood screening results, for the purpose of providing a scientific basis for recruitment and retention of blood donors, improving blood safety, and avoiding waste of blood resources. 【Methods】 A total of 1 548 204 voluntary blood donors in Guangzhou from 2016 to 2020 were selected as the research objects, and the blood samples were screened by dual ELISA and once NAT. The unqualified rate of different years and populations were counted and the analysis of risks of unqualified blood testing was performed by conditional Logistics regression. 【Results】 An overall unqualified rate of blood screening was 2.52% in Guangzhou from 2016 to 2020, the unqualified rate of every year showed a downward trend first and then an upward trend. HBsAg and ALT were the two primary deferral causes, the positive rate was 0.65%(10 129/1 548 204) and 1.22%(18 824/1 548 204), respectively; the unqualified rate in male blood donors3.10%(31 091/1 004 079) was significantly higher than that in female(P<0.05), and that in blood donors aged 18~25 was 1.84%(12 781/694 374), which was lower than the other three age groups (P<0.05). Fewer students(1.33%, 4 024/302 007) and bachelor degree donors(1.57%, 5 379/341 662) were deferred. Compared with individual blood donors, group blood donors’ deferral rate(2.62%, 21 307/813 664) was higher. The deferral rate of first-time blood donors(4.57%, 24 469/535 551) were higher than the repeated blood donors (P<0.05) , meanwhile, whole blood donors(2.84%, 38 111/1 340 678) higher than those apheresis donors (P<0.05). Gender, age, occupation, education, frequency and blood components donated were risk factors for unqualified blood screening. 【Conclusion】 The deferral rates of voluntary blood donors in Guangzhou showed an overall upward trend, from 2016 to 2022. HBsAg and ALT were the primary deferral causes, and there were differences in demographics and blood donation characteristics. To formulate targeted recruitment strategies according to the test results of voluntary blood donors, and strengthen the publicity of low-risk groups and the consultation and screening before blood donation, will be a great benefit for reducing the blood scrap and guaranteeing the blood safety.

Objective To investigate the impact of anti-reflux modified duodenal exclusion surgery on glucose metabolism in rats with type 2 diabetes mellitus (T2DM), and to elucidate the role of the duodenum in maintaining glucose homeostasis. MethodsForty male Sprague-Dawley rats aged 5 weeks were fed a high-fat diet and induced with T2DM using low-dose streptozotocin. Thirty-six rats that met the T2DM model criteria were randomly divided into three groups: the simple duodenal exclusion surgery group (DE group), the anti-reflux modified duodenal exclusion group (MDE group), and the sham operation group (SO group), with 12 rats in each group. Gastroenterography was performed 4 weeks after surgery, and the body weight, fasting blood glucose levels, and serum glucagon-like peptide-1 (GLP-1) concentrations were measured before surgery and at 1, 2, 4, and 8 weeks post-surgery. Eight weeks post-surgery, the rats were euthanized, and a 1 cm segment of the biliopancreatic loop was collected from each group for pathological sectioning and HE staining to observe the intestinal mucosal villus length under an optical microscope. Results Gastroenterography showed that there was significant reflux of the contrast agent into the duodenal lumen in the DE group, while no reflux was observed in the MDE group. At one week post-surgery, the body weights of rats in all three groups significantly decreased compared to before surgery (P<0.05), and then the body weights of all groups increased over time, with no significant differences between the groups (P>0.05). Compared with the SO group, the fasting blood glucose levels in the MDE and DE groups significantly decreased at all time points post-surgery (P<0.05), while GLP-1 concentrations significantly increased (P<0.05). The fasting blood glucose levels in the MDE group were lower than those in the DE group at all time points post-surgery (P<0.05), but there were no significant differences in serum GLP-1 concentrations between the MDE and DE groups (P>0.05). Regarding intestinal mucosal morphology, the villus lengths of the biliopancreatic loops in the MDE group were significantly shorter than those in the DE and SO groups (P<0.05). Conclusion Anti-reflux modified duodenal exclusion surgery effectively improves glucose metabolism in T2DM rats by preventing the reflux of chyme into the diverted duodenum, thereby enhancing its hypoglycemic effect.