3.Curing method affecting the formation of oxygen inhibition layer on the surface of resin cement.
Wen Xin CHEN ; Xu Dong BAO ; Lin YUE
Journal of Peking University(Health Sciences) 2020;52(6):1117-1123
OBJECTIVE:
To explore the conversion of resin monomer, the change of inorganic component and the influencing factors on the oxygen inhibition layer formed on the cured surface of resin cement.
METHODS:
Three kinds of resin cement were divided into three groups: (1) light-cured group: RelyX Veneer, NX3 (light-cured), Variolink N; (2) dual-cured group: RelyX U200 Automix, NX3 (dual-cured), Multilink Speed; (3) chemically-cured group, and the above 3 types of dual-cured resin cement cured without illumination could be used as chemically-cured resin cement. Each sample was provided with and without oxygen exposure of two matching surfaces, cured respectively, and the variables of light intensity and illumination time were set in the light-cured group and the dual-cured group. Scanning electron microscopy was used to observe the samples' surface morphology. Energy dispersive spectrometer was used to analyze the samples' composition of surface elements. Confocal Raman spectroscopy was used to measure the monomer conversion of resin cement and to obtain the thickness of the oxygen inhibition layer.
RESULTS:
(1) On the surface of cured resin cement, the weight percentage of oxygen element in the aerobic side was higher than that in the anaerobic side (P < 0.05), and the weight percentage of inorganic element was lower than that in the anaerobic side (P < 0.05). (2) The surface monomer conversion of the cured resin cement on the aerobic surface was significantly lower than that on the anaerobic surface (P < 0.05), and the surface monomer conversion on the aerobic surface and the anaerobic surface was the lowest in the chemically-cured group (P < 0.05), the dual-cured group was the highest (P < 0.05), and the light-cured group was between them. With the increase of light intensity or illumination time, the surface monomer conversion increased (P < 0.05). (3) The thickness of the oxygen inhibition layer was the thickest in the chemically-cured group [(40.27±2.81) μm](P < 0.05), the thinnest in the dual-cured group [(21.87±5.42) μm](P < 0.05) and light-cured group [(23.73±3.84) μm] was between them. With the increase of light intensity or illumination time, the thickness of the oxygen inhibition layer of resin cement decreased (P < 0.05).
CONCLUSION
When resin cement is exposed to oxygen, it will form an oxygen inhibition layer, its surface's inorganic filler is less, the surface monomer conversion is lower. The surface monomer conversion and the thickness of oxygen inhibition layer are affected by curing mode and illumination factors.
Materials Testing
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Oxygen
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Resin Cements
4.Evaluation of the early outcomes of mini-open lumbar microdiscectomy
Xin-Sheng PENG ; Li-Yan CHEN ; Fo-Bao LI ;
Chinese Journal of Microsurgery 2006;0(06):-
Objective To evaluate the early outcomes of mini-open lumbar microdiscectomy. Methods There were 38 cases in each group of mini-open lumbar mierodiscectomy and conventional discecto- my.Operating time,blood loss,time of leaving the bed and length of hospital stay were compared in two groups.MacNab criteria were used to evaluate the outcomes.Results To compare the conventional discec- tomy group,microdiscectomy group spent similar operating time,but had less blood loss(P
5.Comparative analysis of laser confocal microscopy and corneal smear in the diagnosis of fungal keratitis
Xiao-Hui, SUN ; Xin-Xin, LI ; Jia-Jun, ZHANG ; Bao-Shi, CHEN ; Li-Juan, LIU
International Eye Science 2017;17(6):1147-1149
AIM: To comparatively analyze the application of laser confocal microscopy and corneal smear in the diagnosis of fungal keratitis.METHODS: Totally 77 patients (77 eyes) diagnosed as fungal keratitis were selected.Laser confocal microscopy and corneal smear examination were performed to observe the characteristics of the images, and the detection rate of fungus were compared between the two methods.RESULTS: Of the 77 patients, 66 eyes (86%) were positive and 11 eyes were negative detected by laser confocal microscopy;51 eyes (66%) were positive and 26 eyes were negative detected by corneal smear examination, the difference was statistically significant compared between two group (P<0.05).CONCLUSION: Laser corneal confocal microscopy is relatively safe and sensitive.If combined the application of laser corneal confocal microscopy and corneal smear examination in clinical, the diagnosis rate of fungal keratitis may be improved.
6.Effects of quercetin on H2 O2 - induced oxidative damage in human retina pigment epithelium cells
Jia-Jun, ZHANG ; Xin-Xin, LI ; Bao-Shi, CHEN ; Li-Juan, LIU
International Eye Science 2016;16(11):2010-2013
AIM: To discuss the protective effects and possible mechanisms of quercetin in oxidative damage of human retina pigment epithelium ( RPE) cells induced by H2 O2 .METHODS: RPE cells were subculture, and they were divided into negative control group: cultured with normal culture medium;oxidative injury group:100 μmol/L H2 O2 treated for 12h; quercetin low dose group: 100 μmol/L quercetin incubated for 24h then treated with 100 μmol/L H2 O2 for 12h; and quercetin high dose group:100 μmol/L quercetin incubated for 24h then treated with 100 μmol/L H2 O2 for 12h. Cell viability were tested by MTT colorimetric detection, apoptosis rate was detected by flow cytometry, apoptotic cell morphology was observed by Hochest33258 staining, expression of catalase (CAT), superoxide dismutase ( SOD) and glutathione peroxidase ( GSH-Px) were tested by colorimetric detection.
RESULTS: Quercetin inhibited H2 O2 - induced cell viability decreased in RPE cells, after treated with different concentrations of quercetin, RPE cells activity increased to (79. 67±4. 98)% and (83. 00±3. 60)%, which had statistical significance difference compared with oxidative damage group (48. 93±3. 39)% (P<0. 05). After treated with different concentrations of quercetin, the apoptosis rate of RPE cells decreased to (23. 23±3. 29)% and (16. 23±1. 94)%, respectively, which had statistical significance difference compared with oxidative damage group (38. 03±4. 76)%(P < 0. 05 ). In addition, quercetin also increased the expression of CAT、SOD、GSH-Px in RPE cells, which had statistical significance difference compared with oxidative damage group.
CONCLUSION:Quercetin effectively inhibited H2 O2 -induced RPE cells damage by improving cell antioxidant enzyme activity, which provide reliable experimental basis for the treatment of injuries in RPE cells.
7.Blood-saving effect of acute plateletpheresis and back-transfusion in patients undergoing open heart surgery with CPB
Haiyan WEI ; Hongwei SHI ; Hongguang BAO ; Yali GE ; Yuan ZHANG ; Xin CHEN
Chinese Journal of Anesthesiology 2011;31(7):812-815
ObjectiveTo assess the blood-saving effect of acute plateletpheresis (APP) and back-transfusion in patients undergoing open.heart surgery with CPB.MethodsThirty ASA Ⅱ or Ⅲ patients aged 41-63 yr weighing 52-72 kg undergoing open heart surgery with CPB were randomly divided into 2 groups (n =15 each):control group (group C) and APP group.In APP group,platelet-rich plasma was harvested immediately after induction of anesthesia and transfused back to the patient after termination of CPB and neutralization of heparin with protamine.In group C plateletpheresis was not performed.Hb,Plt,PT,APTT and Fib were measured before induction and at 1,24 and 48 h after operation.CPB time,aortic crossclamping time,postoperative chest tube drainage and blood product transfusion requirements were recorded.ResultsIn APP group the volume of the whole blood processed for plateletpheresis was (1285 ± 185) ml and ( 192 ± 38) ml of platelet-rich plasma was sequestered.The platelet count of the sequestered plasma was(817 ± 282) × 109/L,accounting for (21 ± 3) % of the total number of Pit in the whole blood volume.The plateletpheresis took (35 ± 10) min.The platelet count at 1 h after operation was significantly higher in APP group than in group C.The volume of postoperative chest tube drainage at 24 h after operation was significantly lower in APP group than in group C.Less allogeneic RBC and Plt were transfused in APP group than in group C.There was no significant difference in other variables between the 2 groups.ConclusionAPP has blood-saving effect in patients undergoing open heart surgery with CPB.
8.Posterior short-segmental pedicle screw fixation in treatment of 186 patients with single-level thoracolumbar burst fracture without nerologic deficit
Junhua WANG ; Huilin YANG ; Dechun GENG ; Liang CHEN ; Zhaohua BAO ; Xin MEI
Chinese Journal of Tissue Engineering Research 2010;14(17):3185-3188
BACKGROUND:There are many methods to treat thoracolumbar fractures However,it remains unclear whether a simple operation to treat a thoracolumbar burst fracture can decrease the trauma and obtain better effect to avoid the enlargement of operation.OBJECTIVE:To investigate the clinical outcome of posterior short-segmental transpedicular screw system internal fixation in treatment of single-level thoracolumbar burst fracture without nerologic deficit.METHODS:A total of 186 patients with single.level thoracolumbar burst fracture but without nerologic deficit treated in the First Affiliated Hospital of Soochow University between September 2003 and January 2008,including 152 males and 34 females,aged18 10 65 years.were treated by posterior pedicle screw The intraspinal bone fragments were treated with indirect decompression.All patients were checked with radiography and CT scan before/after operation as well as before implant removal.The correction of anterior vertebral body height and the ratio of bone fragment to cross section area of spinal canal were measured.RESULT AND CONCLUSION:Compared with normal.the anterior vertebral body height was 42%before operation,98%after operation,and 98%before implant removal The ratio of bone fragment to cross section area of spinal canal was 34%before operation,13%after operation.and 8%before implant removal.Internal posterior short-segmental transpedicular screw fixation treating single-level thoracolumbar burst fracture without nerologic deficit can obtain stability of spinal column,and it is beneficial to recovery of body height,physiologic postu ral contour and canal volumn .
9.Mechanism Underlying the Role of HIF-1αduring Hepatocyte Apoptosis in Intermittent Hypoxia with Pulmonary Emphysema in Rats
Jingyan ZHAN ; Huaiyong CHEN ; Qi WU ; Xin SUN ; Jing FENG ; Xue LI ; Long XU ; Cuiping BAO
Tianjin Medical Journal 2014;(2):156-159
Objective To investigate the effect of intermittent hypoxia (IH) with pulmonary emphysema on the ex-pression of hypoxia inducible factor-1α(HIF-1α),Bax and Bcl-2, and the mechanism underlying the role of HIF-1αin he-patocyte apoptosis thereof. Methods Sixty rats were randomly divided into four groups: normal control group, rats were treated normally;IH group, rats were treated by 30 s nitrogen and then 90 s air, and rats were treated by from 9:00-17:00 daily;pulmonary emphysema group, rats were treated by smudging for half an hour, twice a day (8:00 and 18:00);IH with pul-monary emphysema group, rats were treated by 30 s nitrogen and then 90 s air from 9:00-17:00 daily. After exposure four-teen weeks, rats were killed. qRT-PCR assay was conducted to detect the expression of HIF-1α mRNA, Bax mRNA and Bcl-2 mRNA in live tissues. Results The expressions of HIF-1αmRNA, Bax mRNA and Bax/Bcl-2 were significantly higher in IH with pulmonary emphysema group than those in control group,IH group and pulmonary emphysema group (P<0.05). The expression level of Bcl-2 mRNA was significantly lower in IH with pulmonary emphysema group than that of con-trol group and pulmonary emphysema group (P < 0.05), but no significant difference compared with that of IH group (P >0.05). The levels of HIF-1αand Bax were positively correlated with the level of Bax/Bcl-2 (r=0.732 and 0.699),but the lev-els of HIF-1αand Bax were negatively correlated with the level of Bcl-2 (r=-0.705). Conclusion The expression levels of HIF-1αmRNA, Bax mRNA and Bcl-2 mRNA were over-regulated in hepatocytes induced by intermittent hypoxia with pul-monary emphysema. The HIF-1αexpression was correlated with Bax and Bcl-2, suggesting that HIF-1αmay promote the hepatocyte apoptosis through transcriptional co-activators, Bax and Bcl-2.
10.Optimization of Hydrogen Production Conditions of Photosynthetic Bacteria Group by Orthogonal Test
Bao-Chen CUI ; Guo-Xin ZHANG ; Bo HOU ; Shu-Yuan SHAO ;
Microbiology 2008;0(12):-
The influence factors for hydrogen production using photosynthetic bacteria group were studied. The effects of carbon sources, nitrogen sources, carbon concentration, nitrogen concentration, initial pH value, illumination mode and inoculation amount on hydrogen production were investigated by experiment of single factor and orthogonal experiment. The optimum process conditions were as follows: the best bacteria group was number 3, the glucose was carbon source and concentration of carbon source was 3 g/L; the urea was nitrogen source and concentration of nitrogen source was 9 g/L; the inoculation amount was 10%; initial pH value was 8.5; the illumination mode was 12 h light and 12 h dark alternation; incubation temperature was 30?C. The main factors affecting hydrogen production were strain, carbon sources, carbon source concentration and nitrogen suorces.