OBJECTIVE: To explore the effects of two methods of smear layer removal on the surface properties of dentin. METHODS: Sixty extracted sound third molars were collected in this study, and were prepared as uniform dentin specimens with smear layer. All specimens were randomly divided into three groups: Control group, ultrasonic treatment (UT) group and etched treatment (ET) group. Scanning electron microscope (SEM) were used to observe the surface micromorphology of all three groups. Then, the surface elements, mineral phases and functional groups were analyzed by energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and flourier transformed infrared spectrometer (FTIR) respectively. The mechanical properties, hydrophilicity and biocompatibility were also further evaluated. RESULTS: It was revealed that dentin tubules of UT and ET groups were exposed, but lots of dentin debris piled up on the surface of the control one which covered up dentin tubules on the surface. The EDX results should that the weaker peak value of calcium and phosphorus in ET group than control and UT groups. Characteristic peaks of hydroxyapatite could be seen by XRD in all of the three groups, but lower distinctive peaks of amide Ⅰ, Ⅱ and Ⅲ bands of collagen of the dentin surface in control group than in ET and UT groups. The microhardness results showed that ET group was lower than control and UT groups, the difference was significant (P < 0.05). Better hydrophilicity of ET group was investigated (P < 0.05) than control group and UT group. Cells could be observed to adhere normally to dentin surface of each group which meant that all of the three groups had good biocompatibility. CONCLUSION Both UT and ET could effectively remove the smear layer on the surface of dentin and had no adverse effect of the dentin micromorphology and biocompatibility. The ultrasonic removal of the smear layer did not influence the mineral structure, hydrophilicity and mechanical properties of dentin surface. Although ET can effectively improve the hydrophilicity of dentin but decreased mechanical properties and the content of calcium and phosphorus.
Dentin/ultrastructure* ; Humans ; Surface Properties ; Smear Layer ; Molar, Third ; Microscopy, Electron, Scanning ; Dental Etching/methods*

Objective: To construct a scientific and perfect evaluation index system of infectious disease prevention and control ability in colleges and universities, so as to provide reference tools for colleges and universities to effectively respond to infectious disease. Methods: The initial framework of the evaluation index system of infectious disease prevention and control ability in colleges and universities was constructed by using literature analysis method. Experts familiar with infectious disease prevention and control or school health work were selected to conduct two rounds( n =16，18) of Delphi expert consultation for determining the evaluation index system. Analytical hierarchy process was used to calculate the index weights and combined weights. About 198 prevention and control personnel were conveniently selected from 3 universities in Inner Mongolia Autonomous Region to comprehensively evaluate the evaluation indicators by using fuzzy comprehensive evaluation method. Results: After two rounds of Delphi consultation questionnaire, the effective recovery rates were 80.0% and 90.0%, the expert authority levels were 0.89 and 0.86, the expert harmony coefficients for Kendall W were 0.166 and 0.310, and the variation coefficient of each index was <0.25. Finally, the evaluation index system of infectious disease prevention and control ability of colleges and universities included 4 first level indicators, 14 second level indicators and 75 third level indicators. The weights of prevention and monitoring and early warning, organizational system guarantee, emergency management, rehabilitation and summary were 0.176, 0.476, 0.268 and 0.080, respectively. The top 3 weights of the secondary indexes were 0.623 for infectious disease surveillance and early warning, 0.595 for loss assessment and 0.370 for emergency response. The score of fuzzy comprehensive evaluation of the index system of infectious disease prevention and control ability in colleges and universities was 79.148, suggesting a high level. Conclusion The established evaluation index system of infectious disease prevention and control ability in colleges and universities is scientific and reasonable, which is conducive to provide tool reference for the evaluation of infectious disease prevention and control ability in colleges and universities.

OBJECTIVE To explore the clinical distribution and drug resistance of common species of pathogens iso-lated from a three-A hospital of Guangzhou from Jan.2017 to 2023 Dec.so as to provide bases for clinical diagno-sis and reasonable use of antibiotics.METHODS A total of 10,086 strains of aerobic bacteria were clinically isola-ted from the patients who were hospitalized in a three-A hospital of Guangzhou from 2017 to 2023.The constituent ratios of the common species of pathogens,specimen sources,distribution of departments and drug resistance rates to commonly used antibiotics were retrospectively analyzed.RESULTS Totally 10,086 strains of pathogens were isolated from the specimens of the hospitalized patients from 2017 to 2023.Klebsiella pneumoniae,Pseudo-monas aeruginosa,Escherichia coli,Acinetobacter baumannii and Staphylococcus aureus ranked the top 5 species of pathogens.The sputum,midstream urine and whole blood were the major specimen sources.The hospital-asso-ciated infection was highly prevalent in critical care medicine department,neurology department,geriatrics depart-ment,neurosurgery department and urology department.The result of drug resistance showed that the drug re-sistance rates of the K.pneumoniae and P.aeruginosa strains to various types of antibiotics showed upward trends(P＜0.05);the drug resistance rate of the A.baumannii strains to imipenem was decreased,while the drug resist-ance rates to most of the antibiotics were more than 45％.No gram-positive cocci strains that were resistant to vancomycin,teicoplanin or linezolid were found.CONCLUSIONS The common clinical isolates of pathogens are generally resistant to antibiotics.It is necessary for clinicians to attach great importance to the culture of pathogens and drug susceptibility testing and reasonably use antibiotics based on the result of drug susceptibility testing so as to reduce the occurrence and spread of drug-resistant strains.The hospital should strengthen the surveillance of drug resistance of bacteria so as to boost the clinical curative effect,standardize the management and use of antibi-otics and take effective measures to control of the hospital-associated infection.

Objective To investigate the influencing factors related to the severity of tinnitus with normal hearing and to provide a clinical basis for the treatment of such patients.Methods From November 2019 to May 2020,150 normal hearing patients with tinnitus as their first chief complain in the outpatient clinic of our center were selected.The severity of tinnitus was assessed by the tinnitus handicap inventory(THI),and the quality of sleep and psychological condition were assessed by the Pittsburgh sleep quality index inventory(PSQI)and the anxie-ty and depression scale(HADS).The relationship between tinnitus severity and patients'gender,age,duration of illness,tinnitus side,tinnitus dominant sound frequency,tinnitus dominant sound loudness,sleep quality,anxiety and depression were analyzed using Pearson's method and Logistic multi-factor regression.Results The Pearson correlation analysis suggested that sleep quality(r=0.667,P＜0.001),anxiety status(r=0.603,P＜0.001)and depression status(r=0.593,P＜0.001)were correlated with the THI classification,and patients with poorer sleep quality and higher anxiety and depression scores had more severe tinnitus.Logistic multi-factor regression analysis showed that only sleep quality had a significant effect on THI classification(P＜0.001).Conclusion Sleep quality may be related to the severity of tinnitus patients with normal hearing,and it is important to focus on their sleep sta-tus in the clinical management of such patients.

Objective Based on the sampling test of national drugs,the quality of Huatan Pingchuan tablets was systematically evaluated,and the quality problems were analyzed to provide references and suggestions for the quality control of this variety and to improve its quality standard.Methods A total of 157 batches of samples were tested according to the statutory standard,and based on the testing results and prescription characteristics,microscopic identification and comprehensive analysis of its quality using thin-layer chromatography,high-performance liquid chromatography,and other methods were subsequently established or improved for the exploratory research.Results The established thin-layer chromatography identification for Radix Scutellariae,as well as the content determination methods for Radix Scutellariae,Syringae Cortex,and promethazine hydrochloride,are easy to operate and have good durability and specificity and can be applied to the quality control and evaluation of Huatan Pingchuan tablets.Conclusions The overall quality of the tablets is average;some enterprises should strengthen the quality control of raw medicinal materials(decoction pieces);individual enterprises have significant differences in the quality of samples from different batches,so they need to pay attention to the quality of raw materials and the stability of production processes;the inspection items of the current standards cannot fully reflect the key quality attributes of drugs,and standards improvement work needs to be carried out.

Objective To understand the impact of bed-making manipulation on the air surrounding bed units in hemodialysis room,evaluate the effectiveness of routine terminal disinfection,and provide scientific basis for optimi-zing infection control measures.Methods Air specimens(pre-bed-making group)and environmental object surface specimens(pre-terminal disinfection group)around bed units were collected when hemodialysis was about to be fi-nished.Air specimens after bed-making(bed-making group)and environmental object surface specimens after ter-minal disinfection(terminal disinfection group)were also collected.Bacterial colonies were counted and identified.Results A total of 714 air specimens were collected from 238 bed units of 45 hemodialysis units before and during bed-making.The average bacterial colony count during bed-making was higher than that before bed-making([2.72±3.43]CFU/plate vs[0.69±1.50]CFU/plate,P＜0.05).The qualified rate of microbial colony count before bed-making was higher than that during bed-making(96.64％vs 64.71％,P＜0.05).A total of 450 environmental ob-ject surface specimens from 90 bed units of 45 hemodialysis units were collected before and after terminal disinfec-tion.The average bacterial colony count before terminal disinfection was higher than that after terminal disinfection([8.18±20.6]CFU/cm2 vs[1.49±3.44]CFU/cm2.P＜0.05).The qualified rate of microbial colony count after terminal disinfection was higher than that before terminal disinfection(98.22％vs 92.44％,P＜0.05).The micro-organisms in the air and environment were mainly coagulase negative Staphylococcus.Conclusion Bed-making has a certain impact on the air microorganisms around the bed units,and terminal disinfection can reduce the bacterial co-lony count of the environment.It is necessary to pay attention to the cleaning and disinfection of the environment for medical treatment,and carry out bed-making manipulation under clear condition to minimize the risk of infection.

Purpose To investigate the cortical thickness features in Parkinson's disease(PD)patients at various stages and their association with dopamine transporter(DAT)levels in the putamen.Materials and Methods We retrospectively enrolled 30 PD patients and 15 healthy subject who underwent 11C-CFT PET and T1 MRI scans at the Department of Nuclear Medicine/PET Center of Huashan Hospital from August 2016 to October 2020.DAT average radioactivity in the anterior and posterior putamen was analysis using SPM12 software,with the occipital lobe as the reference region.Cortical segmentation and reconstruction were performed on T1 images using Freesurfer v7.2.The differences in cortical thinning between the groups were compared using a general linear model.Additionally,the relationship between cortical thickness in various brain regions and DAT uptake in the putamen were assessed.Results Compared to healthy subjects,significant cortical thinning was observed in the left inferior parietal lobule and the right and left inferior middle frontal gyrus of PD patients(all P<0.05).There was a significant positive correlation between the cortical thickness of the left inferior parietal lobule and right inferior middle frontal gyrus and DAT uptake in the corresponding anterior/posterior parts of the putamen(r=0.30-0.47,all P<0.05).Furthermore,the DAT uptake in the right precentral gyrus was positively correlated with the ipsilateral posterior putamen,exhibiting a stronger correlation than on the contralateral side(r=0.32,P=0.029).Conclusion The results show that the thickness of the thinning cortex area in the PD patients correlates significantly positively with DAT levels in the putamen,highlighting the importance of the basal ganglia cortical circuit and providing a basis for further research into the neural mechanisms of PD.

Objective To investigate the influencing factors related to the severity of tinnitus with normal hearing and to provide a clinical basis for the treatment of such patients.Methods From November 2019 to May 2020,150 normal hearing patients with tinnitus as their first chief complain in the outpatient clinic of our center were selected.The severity of tinnitus was assessed by the tinnitus handicap inventory(THI),and the quality of sleep and psychological condition were assessed by the Pittsburgh sleep quality index inventory(PSQI)and the anxie-ty and depression scale(HADS).The relationship between tinnitus severity and patients'gender,age,duration of illness,tinnitus side,tinnitus dominant sound frequency,tinnitus dominant sound loudness,sleep quality,anxiety and depression were analyzed using Pearson's method and Logistic multi-factor regression.Results The Pearson correlation analysis suggested that sleep quality(r=0.667,P＜0.001),anxiety status(r=0.603,P＜0.001)and depression status(r=0.593,P＜0.001)were correlated with the THI classification,and patients with poorer sleep quality and higher anxiety and depression scores had more severe tinnitus.Logistic multi-factor regression analysis showed that only sleep quality had a significant effect on THI classification(P＜0.001).Conclusion Sleep quality may be related to the severity of tinnitus patients with normal hearing,and it is important to focus on their sleep sta-tus in the clinical management of such patients.

Objective To understand the impact of bed-making manipulation on the air surrounding bed units in hemodialysis room,evaluate the effectiveness of routine terminal disinfection,and provide scientific basis for optimi-zing infection control measures.Methods Air specimens(pre-bed-making group)and environmental object surface specimens(pre-terminal disinfection group)around bed units were collected when hemodialysis was about to be fi-nished.Air specimens after bed-making(bed-making group)and environmental object surface specimens after ter-minal disinfection(terminal disinfection group)were also collected.Bacterial colonies were counted and identified.Results A total of 714 air specimens were collected from 238 bed units of 45 hemodialysis units before and during bed-making.The average bacterial colony count during bed-making was higher than that before bed-making([2.72±3.43]CFU/plate vs[0.69±1.50]CFU/plate,P＜0.05).The qualified rate of microbial colony count before bed-making was higher than that during bed-making(96.64％vs 64.71％,P＜0.05).A total of 450 environmental ob-ject surface specimens from 90 bed units of 45 hemodialysis units were collected before and after terminal disinfec-tion.The average bacterial colony count before terminal disinfection was higher than that after terminal disinfection([8.18±20.6]CFU/cm2 vs[1.49±3.44]CFU/cm2.P＜0.05).The qualified rate of microbial colony count after terminal disinfection was higher than that before terminal disinfection(98.22％vs 92.44％,P＜0.05).The micro-organisms in the air and environment were mainly coagulase negative Staphylococcus.Conclusion Bed-making has a certain impact on the air microorganisms around the bed units,and terminal disinfection can reduce the bacterial co-lony count of the environment.It is necessary to pay attention to the cleaning and disinfection of the environment for medical treatment,and carry out bed-making manipulation under clear condition to minimize the risk of infection.

Purpose To investigate the cortical thickness features in Parkinson's disease(PD)patients at various stages and their association with dopamine transporter(DAT)levels in the putamen.Materials and Methods We retrospectively enrolled 30 PD patients and 15 healthy subject who underwent 11C-CFT PET and T1 MRI scans at the Department of Nuclear Medicine/PET Center of Huashan Hospital from August 2016 to October 2020.DAT average radioactivity in the anterior and posterior putamen was analysis using SPM12 software,with the occipital lobe as the reference region.Cortical segmentation and reconstruction were performed on T1 images using Freesurfer v7.2.The differences in cortical thinning between the groups were compared using a general linear model.Additionally,the relationship between cortical thickness in various brain regions and DAT uptake in the putamen were assessed.Results Compared to healthy subjects,significant cortical thinning was observed in the left inferior parietal lobule and the right and left inferior middle frontal gyrus of PD patients(all P<0.05).There was a significant positive correlation between the cortical thickness of the left inferior parietal lobule and right inferior middle frontal gyrus and DAT uptake in the corresponding anterior/posterior parts of the putamen(r=0.30-0.47,all P<0.05).Furthermore,the DAT uptake in the right precentral gyrus was positively correlated with the ipsilateral posterior putamen,exhibiting a stronger correlation than on the contralateral side(r=0.32,P=0.029).Conclusion The results show that the thickness of the thinning cortex area in the PD patients correlates significantly positively with DAT levels in the putamen,highlighting the importance of the basal ganglia cortical circuit and providing a basis for further research into the neural mechanisms of PD.