Objective:To investigate the dependence of geometric efficiency (GE) on beam collimation and tube voltage.Methods: The dose profile was measured under the conditions of different collimations and tube voltages and GE was calculated.Results: GE was found to be from 11% to 68%, GE at central position and periphery were found to range from 11% to 49% and 16% to 68% respectively, and weighted GE was found to be from 17% to 58%. GE was increased with beam collimation, while it was less pronounced on tube voltages.Conclusion:The dependence of GE on collimation was significant. Therefore, operators should choose appropriate collimations to reduce the dose burden of patients in CT examinations.

Objective: The purpose of the current study was to investigate the correction coefficient of the characterizations of multi-detector CT (MDCT). Methods: The dose profile of Siemens SOMATOM Definition Flash CT scanner was measured with CT-SD 16 detector under the conditions of different collimations, pitches and tube voltages in phantoms of different diameters, and the ratio between weighted CTDI∞and weighted CTDI100 was calculated. Results:The ratio between weighted CTDI∞and weighted CTDI100, which is growing for increasing beam collimation, was found to range from 1.123 to 1.162 in head phantom and range from 1.118 to 1.173 in body phantom. Conclusion: For MDCT, the use of CTDI100, which is one of the most commonly used characterizations of CT, has always underestimated the levels of radiation dose. Therefore, CTDI100 should be corrected.

Objective:To correct the characterizations of MDCT radiation dose by exploring the relationship between CTDIw,∞ and CTDIw.Methods: CTDI100 and CTDI∞ were measured under the conditions of different collimations, pitches and tube voltages of Siemens Definition Flash CT, and CTDIw and CTDIw,∞ were calculated.Results: There were significant differences between CTDIw and CTDIw,∞ which were measured at 0.05 level. And there were no significant differences between CTDIw,∞ after corrected and CTDIw,∞ which were measured at 0.05 level.Conclusion:The characterizations of MDCT which were commonly used were not accurate enough. The result after correction were very closed to the real CTDIw,∞. This showed that the method to correct CTDIw of Siemens Definition Flash CT was mostly accurate. And methods to correct CTDIw of other MDCT needed to be further studied.

Objective:To establish the quality control method of electrosurgical unit(ESU) through the safety performance test and data analysis for electrotome.Methods: According to the testing standard of ESU, Fluke ESA612 electrical safety analyzer and QA-ES II electrosurgery unit analyzer were applied to test the properties of ESU were using during 2015 and 2016, and the testing results were analyzed.Results:In 2015 and 2016, the qualified rate of quality control results were 79% and 81%, respectively; the problems of unqualified ESU were resolved and their hidden risks in clinical applications were eliminated.Conclusion: By testing the properties of ESU, we can master the performance of the machine; find and deal with the risk of machine in time, and avoid the hidden danger and enhance the risk management for ESU, so that the machine can be safely and effectively applied in clinical surgery.

Anemia of neonate,especially in premature infants,is a common phenomenon in newborns and has attracted more and more attention in the academic world.There are various reasons for anemia.Besides the common pathophysiological basis such as iron deficiency and erythropoietin deficiency,blood group incompatibility,hemolysis and iatrogenic blood loss are also important factors leading to anemia of neonates.Preventive measures for neonatal ane-mia include delayed ligation of the umbilical cord,the application of erythropoietin and the effective reduction of iatro-genic blood loss.At present,blood transfusion is still one of the main treatments for neonatal anemia.However,there are still controversies about transfusion indications as well as it′s short-term and long-term side effects.

Objective: To investigate the effects of hypoxia on osteogenic differentiation of periodontal ligament cells (PDLCs) and the role of hypoxia inducible factor-1α (HIF-1α) in this process. Methods : Human PDLCs were isolated and identified by checking the expression of vimentin and cytokeratin. PDLCs were cultured in normoxia (20% O2) or hypoxia (1% O2) for 12-72 h. Changes of alkaline phosphatase (ALP) activity and mRNA expressions of osteogenic markers ALP, collagen-I (COL1) and runt related transcription factor 2 (RUNX2) were detected. Western blot was used to detect the expression of HIF-1α. After transfected with HIF1α-siRNA, the expressions of HIF-1αand osteogenic differentiation markers were furthered detected. The statistics were analyzed with SPSS13.0. Results: Positive vimentin but negative cytokeratin were observed in primary cultured PDLCs. ALP activity and mRNA expressions of ALP, COL1 and RUNX2 were decreased in PDLCs in hypoxia for 48 h, while HIF-1α expression was increased. After knocking down of HIF-1α with siRNA, HIF-1α was significantly reduced in PDLCs under hypoxia, while ALP activity and mRNA expressions of osteogenic markers were significantly increased. Conclusion Hypoxia may inhibit osteogenic differentiation of PDLCs via upregulated HIF-1α.

By reviewing the ancient materia medica， medical books and modern literature， this paper made a systematic textual research on Haliotidis Concha in famous classical formulas， including the name， origin， producing area， quality evaluation， harvesting and processing， in order to provide a basis for the development of famous classical formulas containing Haliotidis Concha. The textual research showed that Shijueming was the official name of Haliotidis Concha in past dynasties， and there were also aliases such as Qianliguang， Jiukongluo and Zhenzhumu named after its efficacy， properties and near-phonetic characters. Before the Tang dynasty， the original description of Haliotidis Concha was too concise， which could only be identified as the animal of genus Haliotis， family Haliotidae. During the Song， Yuan， Ming and Qing dynasties， the main varieties were H. diversicolor and H. discus hannai. At the beginning of the Republic of China， a variety of animals from genus Haliotis were used as Haliotidis Concha， and varieties were numerous and continued to this day. In ancient and modern times， the main producing areas in China are Hainan， Guangdong and Shandong， while the foreign producing areas are mainly Japan and Vietnam. The quality evaluation of Haliotidis Concha in ancient books was roughly determined by the number of openings of the expiratory orifice， and seven-hole and nine-hole abalone shells were preferred. In modern times， characters as big， neat， unbroken， clean inside and outside， lustrous， thick shells are preferred. Based on the textual research results and combined with the record years of the Shijueming San， it is suggested that the shells of H. diversicolor or H. discus hannai should be used in the development of this formula， and the raw products should be used as medicine.

According to the World Health Organization's world report on hearing, nearly 2.5 billion people worldwide will suffer from hearing loss by 2050, which may contribute to a severe impact on individual life quality and national economies. Sensorineural hearing loss (SNHL) occurs commonly as a result of noise exposure, aging, and ototoxic drugs, and is pathologically characterized by the impairment of mechanosensory hair cells of the inner ear, which is mainly triggered by reactive oxygen species accumulation, inflammation, and mitochondrial dysfunction. Though recent advances have been made in understanding the ability of cochlear repair and regeneration, there are still no effective therapeutic drugs for SNHL. Chinese herbal medicine which is widely distributed and easily accessible in China has demonstrated a unique curative effect against SNHL with higher safety and lower cost compared with Western medicine. Herein we present trends in research for Chinese herbal medicine for the treatment of SNHL, and elucidate their molecular mechanisms of action, to pave the way for further research and development of novel effective drugs in this field.

Objective To analyze risk factors for pulmonary vein obstruction (PVO) after intracardiac total anomalous pulmonary venous connection (TAPVC) repair. Methods A retrospective analysis of clinical data of the patients with intracardiac TAPVC who underwent surgery at our center from April 2009 to April 2019 was conducted. Kaplan-Meier curves were used to assess the risk of postoperative PVO. Logistic regression analysis was used to identify relevant risk factor for postoperative PVO. Results We finally included 169 patients. The median age at surgery was 89.0 (41.5, 195.0) days, and the median weight at surgery was 4.8 (3.8, 6.0) kg. The preoperative PVO rate was 18.3% (31/169). Post-repair PVO occurred in 8.9% (15/169) of the patients. The atresia of common pulmonary and subtype of coronary sinus/right atrium did not significantly affect the risk of PVO (P=0.053, P=0.330). Relevant risk factors included preoperative PVO (P<0.001) and the ratio of left ventricular end-systolic diameter to right ventricular diameter (P=0.025). Conclusion Surgical repair of intracardiac TAPVC has achieved satisfactory results in our center, but the long-term risk of obstruction should not be underestimated. An increased ratio of left ventricular end-systolic diameter to right ventricular diameter and preoperative PVO are associated with post-repair PVO.