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【Objective】 To investigate the environmental pollution of blood collection and supply institutions by using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and evaluate its application value. 【Methods】 Colonies of air from blood donation sites, skin puncture sites of blood donors, platelet storage boxes, platelet collection equipment, object surfaces of related experimental consumables and cuff surfaces of staff after disinfection were collected, and typical colonies after cultivation were selected for microbial identification by microbial mass spectrometry and then compared with bacteria results detected in blood components from May 2017 to May 2021. 【Results】 Aseptic growth, the number of colonies ≤4.0 CFU/ dish, and the number of colonies > 4.0 CFU/dish accounted for 21.20%, 62.20% and 16.60%, respectively. The qualified rate from high to low was platelet storage box, bacteria settling in the air of blood donation room after disinfection, platelet collection equipment, skin puncture site of blood donors after disinfection, the surface of platelet consumables and the surface of medical staff's overalls. After disinfection, the blood donors' skin puncture sites were compared with other collection sites, and the t values were 2.0371, 1.508, 2.109, 1.961 and 1.778, respectively, with no significant difference (P>0.05). Thirty cases of bacterial contamination of blood components were detected from May 2017 to May 2021, among which the detection rate of apheresis platelets was the highest, and the t values were 1.731 and 2.272, relative to the contamination frequency of erythrocytes and plasma bacteria (P>0.05), while the t value was 2.875, relative to concentrated platelets, with significant difference (P<0.05). 【Conclusion】 Bacterial contamination of blood components mostly come from air bacteria settling, blood donors' arms and skin after disinfection, and surfaces of related equipment and materials. Therefore, it is of clinical significance to conduct strict disinfection of working sites, establish disinfection monitoring methods and formulate disinfection hygiene standards in blood stations.
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【Objective】 To observe the effect of hydrogen peroxide atomization sterilizer using low concentration hydrogen peroxide disinfectant on the environment and object surface of physical examination area (hereinafter referred to as " physical examination area" ) in blood centers, so as to provide a simple method which is safe, efficient, easy to operate, harmless to human body and has no corrosive effect on equipment. 【Methods】 The physical examination area was disinfected with atomized hydrogen peroxide sterilizer, and the difference of colony number between air and surface before and after disinfection was compared to evaluate the disinfection effect. 【Results】 After disinfection, the hydrogen peroxide residue was detected for 25 times at 5 points, and the results were (0.7~1)ppm, with no statistical difference (P>0.05). 25 tests were carried out at 5 points, and the quartile of the test results was (0~2)CFU/ dish, and the qualified rate was 100%. The test results of bacteria before and after disinfection were statistically significant (P<0.05), which met the requirements of Class Ⅱ environment in Hygienic Standard for Hospital Disinfection(GB15982-2012). After disinfection, the quartile of surface colony detection results of workbench, blood donor seat, screen and door handle were (0~24.1)CFU/cm2, (1.6~55.4)CFU/cm2, (0~7.2)CFU/cm2 and (0~4.8)CFU/cm2, with the qualified rate at 80%, 48%, 100% and 100%, respectively, which were in accordance with the requirements of Class Ⅲenvironment in GB15982-2012. The number of colonies after disinfection at the above detection sites decreased significantly compared with that before disinfection (P<0.05). The surface contact plate pressing method and cotton swab smearing method were used to detect the number of colonies on the surface of sterilized work tables and blood donor seats, and the detection rate of the former was higher than that of the latter, with statistical significance (P<0.05). 【Conclusion】 After disinfection by hydrogen peroxide atomization sterilizer, the hydrogen peroxide residue met the requirements specified in the manual. The terminal disinfection effect of air in the physical examination area environment can meet the Class Ⅱ environmental requirements of GB15982-2012. However, the number of microorganisms on object surface after terminal disinfection was significantly lower than that before disinfection.
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Objective@#To construct a three-dimensional (3D) finite element model and analyze the biomechanical characteristics during mandibular second molar mesialization using customized lingual appliances and mini-implant.@*Methods@#One adult student volunteer from The First Affiliated Hospital of Zhengzhou University with lower left first molar extraction was selected. After CT scanning, Mimics, Geomagic, ANSYS were employed to develop a 3D finite element model including customized lingual brackets, stainless steel lingual arch wire, buccal buckles, lower dentition, periodontal ligaments and alveolar bone. Four different loading methods (1. the force of 1.470 N loaded at the lingual side only; 2, 3, 4. the forces of 0.490, 0.735 and 0.980 N loaded at both buccal and lingual sides, respectively.) were included. The initial displacements of the lower second molar and stress distribution in the periodontal ligaments were analyzed.@*Results@#More uniform stress distributions in the periodontal membrane of mandibular left second molar were found when the mesial force were loaded at both buccal and lingual sides than the force loaded at lingual side only. More inclination of the second molar was observed when force loaded at both sides than at lingual side only. With the values of the force increased, the mesial inclination potential of the second molar, the initial movement of the second molar and the stress distribution in the periodontal membrane increased. Under the force of 0.735 N at both buccal and lingual sides, mesially inclined initial displacements of the mandibuar second molar were observed and the stress values of von Mises was in the suitable area.@*Conclusions@#Less second molar rotation was found when the force loaded at both buccal and lingual sides than loaded at lingual side only. However, force loaded at both sides would increase the measial inclination potential of the second molar.
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Objective To carry out the performance evaluation on 3 hemoglobin analyzers-URIT-12,HemoCue Hb301 and CompoLab TS.Methods Verification of inter-run precision,intra-day precision,and correlation of the 3 analyzers using samples with different concentrations.Results The lower values of inter-run precision of URIT-12,HemoCue Hb301 and CompoLab TSoft were 1.46％,1.45％ and 1.32％,respectively,and the median values were 1.43％,0.56％ and 1.49％,respectively.The lower values of intra-day precision were 1.86％,1.62％ and 1.32％ respectively for URIT-12,HemoCue Hb301 and CompoLab TSoft,with the median values of 1.45％,1.95％ and 1.78％ and the higher values of 1.86％,1.74％ and 1.81％.Based on the results of Beckman-Coulter AcT5diff automatic blood cell analyzer,linear regression equation and correlation coefficient was calculated and expressed as y=0.960 2x+3.201 3,R2=0.973 4;y=1.112 1x-6.767 9,R2 =0.990 7;y=1.031 5x+0.634 7,R2=0.980 3,respectively.Conclusion The 3 hemoglobin analyzers have better inter-run precision and intra-day precision as well as good correlation with automatic blood analyzer,and thus can be applied in physical examinations before blood donation.
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Objective To carry out regularpersonnel capacity evaluation of quality control laboratory (QC Lab) staff,combinedwith the actual situation of the QC Lab and the requirement of national capacity assessment.Method Establish an evaluation program,including assessment items,frequency,eligibility criteria,etc,to effectively implement the program.Results Two evaluations were conducted for nine staff membersin the lab from 2015 to 2016.The pass rate of the four test items and operation of the instrumentwere 100％.The ability to solve the problem was variable among the staff.Conclusion According to the evaluation results,staff classification management and training will effectively promote the improvement of personnel capacity and ensure the quality of laboratory testing.