Objective To study the difgerence between the IAEA code of practice TRS-Z77 and TRS-398 in the determination of the absorbed dose to water for high-energy photon beams using several cylindrical chambers. Methods For 6 different types of cylindrical chambers,the calibration factors ND,W,Q0 in terms of absorbed dose to water were calculated from the air exposure calibration factors N,,and were compared with the ND,W,Q0 measured in European standard laboratory. Accurate measurements were performed in Varian 6 MV photon beam using 6 cylindrical chambers according to TRS-277 and TRS-398.The beam quality correction factors kQ.Q0 as well as the water absorbed doses were compared.Results For the set of chambers,the difference between ND,W,Q0 computed from Nx and ND.-.Q0 obtained in European standard laboratory was 0.13％ ～ 1.30％.The difference of beam quality correction factors for TRS-277 and TRS-398 was 0.09％ ～0.45％.The distinction of the water absorbed doses obtained according to the two different protocols was 0.27％ ～ 1.40％,and was primarily due to their different calibration factors.Conclusions The discrepancy in absorbed doses determined according to two protocols using different cylindrical chambers is clinically acceptable.However,TRS-398 allows a more convenient localization of chambers,provides a more simple formulation,and offers the reduced uncertainty in the dosimetry of radiotherapy beams.

Delicacy management proves a pressing need in cost management of medical service items in the current hospital operation.This paper first covered the methodology and system of hospital costing.It went on to describe the costing for four major medical service items in a quarter in 2011 using the activity-based costing method with the ultrasonographic section of a large hospital as an example.The outcomes were compared to the traditional costing method and the statutory pricing standards,resulting in the proposal and recommendation on reforming the costing methodology of service item pricing,and applying the activity-based costing management of medical service items in the hospital.

Objective To discuss the effect of formative evaluation for flipped classroom of college English teaching. Method We chose 180 clinical medicine undergraduates from a college and divided them equally into experimental class and control class. In the experimental class, the formative evaluation was implemented for the flipped classroom of college English teaching from September 2014 to June 2015. At the same time, the teaching in the control class was carried out according to the basic process of flipped classroom, with no formative evaluation. At the end of the experiment, the students' satisfaction survey, autonomous learning ability and English proficiency test of the two classes were finished. SAS 9.1 software was used for statistical analysis, and t test was used to compare two class measurement information and count data with chi-square test. Result ①Experimental class' satisfaction of formative assessment teaching design for flipped classroom was 94.45%, which was obviously higher than that of the control class (66.66%). The difference was statistically significant (χ2=7.94, P=0.005). (χ2=7.94,P=0.005).②The score at first, fifth dimension and the overall score of independent learning in experimental classes were respectively (55.31± 4.99)、 (53.61±4.93)、 (247.16±22.10), and they were significantly higher than those in the control class (47.18±4.23)、(45.72±4.01)、(225.92±20.78) (t=8.889, P=0.001;t=7.299, P=0.001;t=6.642,P=0.001), and other dimensions' score was also significantly higher than that in comparative classes (P<0.05). ③The pass-ing rate of CET-4, and the number of students from 505 to 544 and more than 545 fraction in the experi-mental class were respectively 79 (87.78%)、19 (21.11%)、10 (11.11%), and they were significantly higher than those in the control class 61(67.78%)、10(11.11%)、0(0). Conclusion Formative assessment can obvi-ously improve the teaching effect of flipped classroom of college English.

Objective To explore the immune characteristic of a patient with hypogammaglobulinaemia and low natural killer(NK)cell numbers. Methods Case histories were analyzed repeatedly to grasp important characteristics of the disease. A routine blood examination and peripheral blood immunological detection was done. Complete neutrophil function test,lymphocyte proliferation ability and cytokine profile were evaluated. Results A 3-year-old boy was referred to the hospital because of fever and abdominal pain as well as partial intestinal obstruction. Laboratory examination revealed low immunoglobulin,reduced absolute numbers of B and NK cells and deficient B cell function of lower IFN-γ and IL-12 production. The patient also had mesenteric lymphadenopathy and a caecal mass with histology suggestive of ileocecal junctional tuberculosis. The patient was infected with cytomegalovirus(CMV)and fungus,which are not common in simple antibody deficiencies. The patient was followed for four years and during this period the patient had recurrent periodontitis resulting in the loss of one tooth. Conclusions Although the precise mechanism of the defect is unclear,we speculate that the case may cast new light on primary immunodeficiencies predominantly with antibody deficiency.(J Clin Pediatr,2011,29(7):601-608)

Background Glial cell line derived neurotrophic factor (GDNF) is determined to have a neurotrophy effect and promoting effect to the growth of axon.GDNF has been applied in ophthalmology.Research showed that artemin,a new member of GDNF family,has a better function in protection of neuron,but seldom relevant document of distruibution of artemin in retina is found so far.Objective The aim of the present study is to investigate the distribution and expression of artemin in normal rat retinal neuron cells and retinal ganglion cells,and imitate diabetic environment to observe the expression of artemin at the condition of high glucose.Methods Retinal tissue was isolated from clean neonatal SD rats and cultured by expand culture method in DMEM/F12 containing 10% fetal bovine serum.40 mmol/L of glucose was added in medium in the seventh day after culture for 12 hours as experimental group.The expression and location of artemin in retina were tested by real-time PCR and cell immunofluorescence assay.Use of experimental animals followed the Management Regulation of experimental animals of Jiangsu Province.Results Cultured cells showed the typical cell body and processes in the seventh day.Cultured retinal ganglion cells (RGCs) presented the red fluorescence for Thy1.1 antibody,and multiple fluorescence label revealed that RGCs exhibited the green fluorescence for artemin antibody and red fluorescence for Thy1.1 antibody,indicating artemin protein was positively expressed in cultured RGCs.The numbers of positive cells for Thy1.1 antibody was (442±9)/high field in normal culture group and (263±7) /high field in 40mmol/L glucose culture group,showing a significant difference between them (P＜0.05).The expression of artemin mRNA in normal culture group and in 40 mmol/L glucose culture group,was showing a considerably difference between them(P＜0.05).Conclusion Artemin can be expressed in cultured retinal neuron cells and RGCs in rats.High glucose environment down-regulate the expression of artemin.This study proved a new idea for protecting RGCs against damage.

Clinical internships play an important role in higher medical education. According to the new standards in undergraduate medical education set by the MOE and MOH,we identified 4 main problems in our internships training,including lack of awareness of career planning,interns'absence from duty,lack of hands-on opportunities,psychological problems,etc. According to these problems,we carried out a series of solutions such as strengthening intern orientation,especially in aspects of professionalism and clinical skills training,optimizing the rotation schedule and improving the evaluation methods etc. Experiential evidence and perceptions of interns and their tutors showed that these changes were effective.

OBJECTIVE:To study the apoptosis of human leukemic cells induced by Dihydroartemisinin and its molecular mechanism.METHODS:Human leukemia K562 cells were treated by Dihydroartemisinin.The inhibitory effect on cell proliferation was assayed by MTT.Fluorescence microscopy was applied to observe the presence of apoptosis.The expression of caspase-3 was assayed with reverse transcription-polymerase chain reaction(RT-PCR).Levels of mitochondrial and cytoplasmic cytochrome C were determined using Western blot.RESULTS:After treatment with Dihydroartemisinin for 48 hours,the IC50 values of human leukemia K562 cells were 8? 10-5mol? L-1 detected at a wavelength of 570nm by MTT.Distinct morphology changes of cell apoptosis such as karyopyknosis and conglomeration were observed by Hoechst33342/PI staining.RT-PCR assay showed the expression of Caspase-3.Western-blot detection showed the decrease of mitochondrial cytochrome C concentration but the positive expression of cytoplasmic cytochrome C concentration.CONCLUSION:Dihydroartemisinin could inhibit proliferation and induce apoptosis of human leakemic K562 cells,this may partially attributed to the promotion of the delivery of cyt-c and the activation of caspase-3.

Objective To evaluate the prognostic value of microsatellite instability (MSI) in stage Ⅱ colon cancer patients.Methods 120 stage Ⅱ colon cancer patients underwent radical resection in the Department of Colorectal Surgery,Beijing Cancer Hospital from 2000 to 2007.Tissue samples were collected and DNA was extracted for MSI determination using PCR following the Pentaplex panel.Clinical parameters were also combined and analyzed statistically to explore the association between MSI status and clinical parameters.Results The incidence of high frequency of microsatellite instability (MSI-H) was 20.8％ in these 120 stage Ⅱ colon cancer patients.There was a significant correlation between the status of MSI and tumor differentiation (x2 =9.69,P =0.021);However MSI status was demonstrated to be a prognostic factor for disease free survival or overall survival (all P ＞ 0.05).Nor was MSI status associated with tumor relapse or metastasis.Age and preoperative serum CEA level were identified as independent factors for DFS by Cox regression.Conclusion In stage Ⅱ colon cancer patients,MSI status correlates with tumor differentiation,but is not a prognostic factor.

Objective To determine the best extraction process of ginkgo leaves with the total transfer rate of total flavonol glycosides and terpene lactones as the index.Methods The effects of ethanol concentration, solid-liquid ratio and extraction time on extraction process were investigated by orthogonal design method, and the contents of total flavonol glycosides and terpene lactones were detected by HPLC to calculate transfer rate.Results The optimum extraction conditions were as follows:85% ethanol refluxing and extracting for three times;the first time extracting with five-fold amount of solvent (V/W) for 3 hours;the last two times with three-fold solvent (V/W) for 2 hours.Conclusion This extraction process has the advantages of simplicity of operator, reason, energy conservation, high efficiency, and is suitable for industrial production.

To explore an easily executive and conveniently generalized method with effectiveness and low costing for myopia screening at the early stage.Research was performed to testify the reasonability of using axial length/corneal radius (AL/CR) for myopia screening in children by comparing the cost between AL/CR plus vision acuity (VA) and simple VA examination.Chinese school-aged children in Yangfang school district,Beijing (n=1427,aged 6～12 years old) were randomly grouped for either pure VA examination or for VA plus AL/CR examination.Those suspicious myopic children were informed for further refractive examination.Finally,the cost from screening to definite diagnosis of refractive error was calculated.Generally,compared with VA examination,the total cost was reduced by 15.12％ and by 12.34％,respectively,in the elder group using VA plus AL/CR examination.VA plus AL/CR examination is an economical and reasonable method for screening suspicious myopia in Chinese school-aged children compared with pure VA examination.