1.Influence of dose rate reference control level on the design of accelerator shielding
Yaqin ZHENG ; Yajun KANG ; Xuegang CHU ; Fang GUO
Chinese Journal of Radiological Medicine and Protection 2015;35(2):139-141
Objective To explore the influence of dose rate reference control level on the design of accelerator shielding.Methods According to the standards of GBZ 126-2011,GBZ/T 201.1-2007 and GBZ/T 201.2-2011,two different shielding calculation methods,based on the dose rate reference control level and week dose control level,were used to calculate and compare the thickness of accelerator room shielding.Results Under the same condition of maximum weekly workload,the obtained results were different when the calculated dose rate reference control value was larger than dose rate reference control level (2.5 μSv/h).The maximum difference of shielding thickness reached 64 cm.Meanwhile,considering dose rate reference control level,the different accelerator rates could lead to different radiation shielding thickness.Conclusions The dose rate at reference point must be first calculated before calculating shielding thickness.The calculation should be made on the premise that dose rate reference control level is met.
2.Effects of different wave-length lights on proliferation and secretion of growth factors in human retinal pigment epithelium cells
Xiao-fen, ZHENG ; Yu-guo, KANG ; Ren-yuan, CHU
Chinese Journal of Experimental Ophthalmology 2011;29(9):774-779
BackgroundThe study of myopia development is always the hotspot worldwide. Recently,scientist found that some growth factor secreted by retinal nerve epithelium cells and retinal pigment epithelium(RPE)cells are associated with the development of myopia. Whenever, the absorption of RPE cells to different wave-length lights is different. ObjectiveThis study was to investigate the effects of different wave-lengths lights on the proliferation of human RPE cells, and explore the influence of different wave-lengths lights on RPE cells secreting hepatocyte growth factor(HGF) ,basic fibroblast growth factor(bFGF) and transforming growth factor-β(TGF-β).Methods The fourth to fifth passages of human embryonic RPE cells were exposed to blue light( λ =480 nm),red light( λ =775 nm) and white light. The cells of control group were harvested in normal condition. The proliferation and growth of RPE cells were assayed by MTT,and the ultrastructure of cells was examined under the transmission electron microscopy at 48 hours after light exposure of RPE cells. Enzyme linked immunosorbent assay(ELISA) was adopted to determine the concentrations of HGF,bFGF and TGF-β in the culture medium in 12,24,48,72 hours. The expression of HGF mRNA in RPE cells was detected by RT-PCR. This study was approved by Ethic committee of Fudan University. ResultsThe A490 values of the cells exposed to blue light,red light,white light and white light were 0. 0218±0. 0014 ;0. 0353±0. 0025 ;0. 0371 ±0. 0024 and 0. 0445 +0. 0046 respectively with the significant difference among 4 groups ( F =12. 579, P<0.05 ), and A490 value in blue light group, red light group were significantly lower than that of the control group ( t =2.043 ; t =2.024, P<0.05 ). ELISA showed that the concentrations of HGF and TGF-β in culture medium were evidently elevated as the prolongation of light exposure in various light exposure groups in 72 hours(HGF) and 48 hours(TGF-β) compared with 12 hours with a predominating rise in the control group. The statistically significant differences were found in the concentrations of HGF and TGF-β between control group and blue light group or red light group in the( all P<0. 05 ). The bFGF level was decreased with the time increase of various light exposure with the significant differences in 72 hours compared with 12 hours( P<0.05 ). RT-PCR revealed the considerable difference about expression of HGF mRNA in RPE cells among these four groups( P<0. 05 ), and the lest expression in HGF mRNA was in the blue light group compared with control group( t =3. 972,P<0.05 ). Thinning of the chromatin, decreasing of organelle and loss of cellular membrane were seen in the blue light group, but no obvious change of ultrastructure of human embryo RPE cells was found in the ret and white light groups. ConclusionsThe irradiation of different wave-length light can effect the growth and proliferation and secretion of HGF,bFGF and TGFβ in human RPE cells in vitro,implying myopia formation is associated to exposure of different wave-length light.
3.Construction of Nano Silver Modified Super Hydrophobic Interface for Detection of Trichlorfon Pesticides
Nan ZHANG ; Longzhen ZHENG ; Leiyan XIONG ; Zanru GUO ; Xiaowei KANG ; Qian WANG ; Zirui WU ; Zemin DONG
Chinese Journal of Analytical Chemistry 2017;45(2):261-267
Super hydrophobic interface modified with silver nanoparticles was fabricated for the detection of pesticide residues.By using a chemical reduction method,silver nanoparticles were deposited on the substrate surfaces with different microscopic pore structures.Two kinds of composite substrates,including regular stainless steel mesh and cellulose polyester film,were used.The pre-treatment of the substrate with fluoridated reagents was used to form a super hydrophobic interface,which made the target molecules on the surface concentrate effectively.The surface with the cellulose polyester substrate was used to detect Rhodamine 6G (R 6G) effectively with surface enhanced Raman scattering (SERS) technique.The results showed that the detection hmit was 10-16 mol/L.In addition,the surfaces based on the stainless steel mesh and cellulose polyester substrate were used to detect trichlorfon pesticide with detection limits of 1 × 10-15 mol/L and 1 × 10-16 mol/L,respectively.
4.Experimental study on biomechanical property of the Skin in pig's back
Xin-Feng WU ; Guo-Zheng KANG ; Lin-Mao QIAN
Journal of Medical Biomechanics 2009;24(6):452-457
Objective To investigate and evaluate the biomechanical property of the skin in pig's back in order to provide the essential theoretical basis for clinical and skin products.Method Taking the skin in pig's back as experimental material,the monotonic tensile and cyclic tension-tension tests with difierent loading rates was researohed respectivaly.Meanwhile,with different loading directions and stress levels the creep and cy-clic tension-tension tests were also been studied experimentally.Result The capacity of resisting tensile,creep and cyclic deformation of pig's skin in the direction along the Langer's line is stronger than that perpen-dicuiar to the Langer's line.The creep curve of pig's skin is load-dependent and consisted of three phases a-bout deceleration phase,stabilization phase and destruction stage.Pig's skin exhibits apparent ratcheting un-der asymmetry stress cycle.Ratcheting deformation displays significant mean stress,stress amplitude and loading speed dependence.Condusion Based on the experiment,the biomechanics property of skin's vis-coelasticity and anisotropic feature have been sysmarie stadied,it's provide necessaw theoretical fundation for clinical and leather products.
5.Detection and Partial Characterization of γ-glutamyltranspeptidase from Cordyceps sinensis Mycelia
Jiang-Lan YUAN ; Xu KANG ; Zheng HU ; Guo-Lin ZOU
China Biotechnology 2008;28(10):100-105
γ-glutamyltranspeptidase was detected from the cultured mycelia of Cordyceps sinensis (CSGT). Km and Vmax of CSGT was 2.54×10-4 mol/L and 0.1808 mol/L·min respectively when L-glutamic acid 5-(4-nitroanilide) (GpNA) and glycyglycine was used as its substrate. CSGT was stable from pH 8.0 to 11.0 and at or below 20℃. It was optimally active at pH 9.0~10.0 and 30℃. A series of reducing reagents could activate CSGT, and metal cations such as Zn2+, Cu2+, Hg2+ , Mn2+ inhibited strongly activity of the enzyme, but K+, Ca2+, Mg2+ and Na+ at high concentrations had no effect on its activity, indicating that its active center could contain -SH.
6.Experimental study on biomechanical property of the Skin in pig's back
Xin-Feng WU ; Guo-Zheng KANG ; Lin-Mao QIAN
Journal of Medical Biomechanics 2009;24(6):452-457
Objective To investigate and evaluate the biomechanical property of the skin in pig's back in order to provide the essential theoretical basis for clinical and skin products.Method Taking the skin in pig's back as experimental material,the monotonic tensile and cyclic tension-tension tests with difierent loading rates was researohed respectivaly.Meanwhile,with different loading directions and stress levels the creep and cy-clic tension-tension tests were also been studied experimentally.Result The capacity of resisting tensile,creep and cyclic deformation of pig's skin in the direction along the Langer's line is stronger than that perpen-dicuiar to the Langer's line.The creep curve of pig's skin is load-dependent and consisted of three phases a-bout deceleration phase,stabilization phase and destruction stage.Pig's skin exhibits apparent ratcheting un-der asymmetry stress cycle.Ratcheting deformation displays significant mean stress,stress amplitude and loading speed dependence.Condusion Based on the experiment,the biomechanics property of skin's vis-coelasticity and anisotropic feature have been sysmarie stadied,it's provide necessaw theoretical fundation for clinical and leather products.
7.The combination application of intracranial buried electrode and cortical electrical stimulation in the excision of the epileptogenic zone in the central zone
Jie ZHENG ; Wenling LI ; Yali DU ; Tao GUO ; Chuandong LIANG ; Jinsheng KANG ; Jiang WU
Chinese Journal of Nervous and Mental Diseases 2009;35(12):705-708
Objective To investigate the combination application of the intracranial buried electrode and electrical stimulation techniques in excising the epileptogenic zone in the central zone.Methods Seven patients with epileptogenic zone located close to or in the central zone of brain were recruited in the present study.The lone term ECoG monitoring and electrical stimulation of the codex were performed to identify the epileptogenic zone and the central zone of the brain after patients received intracranial electrode implants.The epileptogenic zone was excised with maximum preservation of the cen-tral zone.The patients were follow-up for 6 to 12 months,the outcomes were evaluated based on the Engel's scale and the Karnofsky(KPS)score.Results Seven patients did not experience any seizures and their Engei's and KPS scores were markedly improve after operation.Conclusions Intracranial buried electrodes and cortical electrical stimulation can guide the resection of epileptogenic zone in the central zone.Patients have no seizure and no serious dysfunction after operation and their quality of life was improved markedly.
8.The study of symptomatology and electroencephalogram in central region diastematia epilepsy
Tao GUO ; Yali DU ; Jinsheng KANG ; Jie ZHENG ; Qianwei LIU ; Wenling LI ; Wenqing ZHAO ; Changzheng DONG
Chinese Journal of Neurology 2012;45(1):40-44
ObjectiveTo explore the clinic symptom and the characteristics of video,tightly close,intracranial electroencephalogram (EEG) of patients with central region diastematia epilepsy. Methods Retrospective analysis of 9 patients with central region diastematia epilepsy admitted from June,2007 to August,2009.The characteristics of all patients' seizure symptom and EEG manifestation were analyzed using patients' medical history,video and EEG records.ResultsPatients with central region diastematia epilepsy had relatively long sezure history.The duration of seizure was commonly short,with frequent episode and no obvious intelligence impairment.The seizure was often accompanied with the hyperkinesia in the lower limbs.Scalp EEG showed discharges with low amplitude waves in the mean line area.The superhigh amplitude and regular rhythm slow sharp wave could be found in the diastematia cortex EEG.All patients had an Engel Class Ⅰ outcome after surgery.ConclusionThe seizure symptoms are characteristic in the patients with central region diastematia epilepsy,and some special manifestations can be found in different phase,wave amplitude,rhythm,lead array.
9.Endoscopic thyroidectomy via breast areola approach
Jie KANG ; Youben FAN ; Bo WU ; Bomin GUO ; Jun YAN ; Pin ZHANG ; Qi ZHENG
Journal of Endocrine Surgery 2009;3(4):236-238
Objective To investigate the curative effect of endoscopic thyroidectomy via breast areola approach.Methods The clinical data of 28 cases of endoscopic thyroidectomy via breast areola approach were retrospectively summarized.Results The mean diameter ofthe tumor Was 2.9(1.7~4.2)cm.The mean operative time Was 128(95~165) min.Pathologic data:adenoma in 15 cases,nodular goitar in 12 csses,papillary carcinoma indicated intraoperatively by frozen section in 1 case.One case occurred temporary hoarseness.No intraoperative and postoperative hemorrhea and convulsion after operation.Minor pain and discomfort in anterior chest continued for 7~19d in 18 cases,all without taking painkillers,satisfaction rate of beauty was 90 percent.Condusions Endoscopic thyroidectomy via breast areola approach is safe and feasible for patients with thyroid diseases,and has excellent cosmetic results.
10.Application of clinical flow examination scale in standardized residency training of anesthesiology
Fei GUO ; Kang HUANG ; Chaomeng WU ; Yeying ZHENG ; Tao ZHU ; Lei DU
Chinese Journal of Medical Education Research 2021;20(2):208-212
Objective:The clinical flow examination (CFE) scale was used to evaluate the effect of standardized residency training in the department of anesthesiology in West China Hospital of Sichuan University.Methods:Using the CFE scale, 98 students were tested three times consecutively, and then satisfaction surveys were conducted on the assessment tutors and students respectively. IBM SPSS software was used to test the reliability and validity of the CFE scale, and then the scores and satisfaction were statistically analyzed. SPSS 23.0 was used for t test and chi-square test. Results:The CFE scale had high reliability and validity, and the results of 95 students were included for analysis. The 95 students had a very high rate of excellence in basic, professional and final grades. Except that the basic, professional and final overall scores of the female group were higher than those of the male group ( P < 0.05), the differences between the other groups were not statistically significant ( P > 0.05). Results of the CFE satisfaction survey showed that the satisfaction of students and instructors was 98.9% and 100%, respectively. Conclusion:CFE scale can be well used to evaluate the effect of standardized residency training, and the training effect of anesthesiology department in our hospital is good and basically homogeneous, while there is still room for further improvement.