Objective To explore cross-talk elimination method in the determination of gross α and gross β activities using a low-background α/β gas-flow proportional counter. Methods A CLB-104 low-background α/β gas-flow proportional counter was used in this study. First, the α threshold was increased to eliminate the cross-talk counting caused by β particles in the α channel. Then, the α-β anticoincidence threshold was reduced to eliminate the cross-talk counting induced by low-energy α particles in the β channel, and β counts were corrected to eliminate the counts induced by internal convention electrons in the β channel. Finally, gross α and gross β activities of non-saline water samples with different activity levels were determined and compared with gross α and gross β activities of the same samples determined on a BH1227 low-background α/β solid scintillation counter, in order to verify effectiveness of the cross-talk elimination method. Results By eliminating the cross-talk counts of β particles in the α channel and the cross-talk counts of α particles in the β channel, and deducting the counts of internal convention electrons in the β channel, the gross α and gross β activities of the same samples determined by CLB-104 were consistent with the values determined by BH1227. Conclusion Cross-talk counts induced by low-energy α particles or β particles can be eliminated by threshold adjustment, and the counts caused by internal convention electrons in the β channel can be eliminated by correction.

Objective To analyze the risk factors of intrauterine adhesion (IUA) after hysteroscopic resection of endometrial polyps. Methods Totally 359 patients undergoing hysteroscopic resection of endometrial polyps from January 2013 to December 2016 were enrolled in this study. The clinical data of IUA group and non-IUA group were compared. Univariate analysis was performed to identify the risk factors of IUA,and multivariate Logistic regression analysis was further performed to get the independent risk factors. Results Of these 359 patients,IUA occured after operation in 56 patients (15.60%). Univariate analysis showed underlying diseases (χ=7.381,P=0.004),multiple polyps (χ=3.376,P=0.040),uterus with uterine fibroids or endometrial hyperplasia (χ=6.495,P=0.009),history of curettage(χ=31.576,P=0.000),pelvic infection (χ=8.582,P=0.001),intrauterine device (χ=7.161,P=0.006),history of cesarean section (χ=5.493,P=0.014),and multigravida were (χ=16.886,P=0.000) the risk factors of IUA. Logistic regression analysis showed other diseases of uterus(χ=19.542,P=0.026),history of curettage (χ=29.614,P=0.000),pelvic infection (χ=5.627,P=0.002),intrauterine device (χ=11.342,P=0.08),history of cesarean section(χ=8.549,P=0.035),and multigravida (χ=15.493,P=0.000) were the independent risk factors of IUA after hysteroscopic resection of endometrial polyps. Conclusion Other diseases of uterus,history of curettage,pelvic infection,intrauterine device,history of cesarean section,and/or multigravida can increase the risk of IUA after hysteroscopic resection of endometrial polyps.

AIM: To investigate the clinical effect of intracameral cefuroxime injection on prevention of endophthalmitis following phacoemulsification.

METHODS: This was a retrospective clinical study. The clinical records were reviewed for 3112 patients(4210 eyes)with cataract phacoemulsification in our hospital from January 2015 to June 2018; 1810 patients(2250 eyes)without intracameral cefuroxime injection were treated as control group from January 2015 to April 2017; 1302 cases(1960 eyes)with intracameral cefuroxime injection were treated as experimental group from May 2017 to July 2018. Patients in both groups were treated with phacoemulsification and intraocular lens implantation. The follow-up period was 1-8mo and the visual acuity and the infectious endophthalmitis were observed and compared.

RESULTS:There were 1 344 eyes with best corrected visual acuity >1.0, 696 eyes with 0.5-0.9, 151 eyes with 0.1-0.4, 59 eyes with <0.1 in control group within 6mo after operation; those in experimental group were 1 136 eyes, 624 eyes, 146 eyes, 54 eyes. No postoperative endophthalmitis case occurred in experimental group. Three postoperative endophthalmitis cases(3 eyes)occurred in control group, 0.13%(3/2250). There was no significant difference between the two groups(P=0.15). All the cases with endophthalmitis were cured. No sever complication was reported with intracameral cefuroxime, corneal endothelium decompensation, retinal toxicity.

CONCLUSION: Intracameral cefuroxime injection is safe and effective in prevention of endophthalmitis following phacoemulsification.

AIM: To observe the efficacy and safety of central hole phakic posterior chamber intraocular lens(ICL V4c)implantation for correction low to moderate myopia.

METHODS: Twenty low to moderate myopia patients(forty eyes)who underwent the ICL V4c implantation in our hospital from January 2016 to June 2017 were observed 1wk, 1mo and 1a after operation respectively. Uncorrected visual acuity(UCVA), best corrected visual acuity(BCVA), equivalent spherical mirrors(SE), intraocular pressure, corneal endothelial cell count, ICL-vault, adverse reaction and complication were investigated.

RESULTS: Postoperative UCVA and BCVA were significantly higher than that in preoperative group(P<0.01). Significant difference was found in UCVA between postoperative groups except between 1mo and 1a. No significant difference were found in BCVA among postoperative groups(P<0.05). Postoperative SE at all time points were lower than that in preoperative group(P<0.01). Average SE after 1wk after operation were close to 0 diopter. The safety index in 1a postoperative were 1.05±0.14 and the effective index was 1.07±0.14. No significant difference was found in intraocular pressure and endothelial cell density after surgery comparing to that in preoperative group(P>0.05). None of subjects developed cataract, glaucoma and decompensation of corneal endothelium. The degree of postoperative satisfaction was 100%.

CONCLUSION: ICL V4c implantation is a safe and effective method for the correction of low to moderate myopia. The visual acuity stabilized 1mo after operation.

AIM: To observe the efficacy and safety of central hole phakic posterior chamber intraocular lens(ICL V4c)implantation for correction high myopia.

METHODS: Fifty-eight high myopia patients(116 eyes)who underwent the ICL V4c implantation in our hospital from January 2016 to June 2017 were observed 1wk, 1mo and 1a after operation respectively. Uncorrected visual acuity(UCVA), best corrected visual acuity(BCVA), equivalent spherical mirrors(SE), intraocular pressure(IOP), corneal endothelial cell count, ICL-vault, adverse reaction and complication were investigated.

RESULTS: Postoperative UCVA and BCVA were significantly higher than that in preoperative group(P<0.01). Significant differences were found between postoperative groups except between 1mo and 1a(P>0.05). Postoperative SE at all time points were lower than that in preoperative group(P<0.01). SE at 1mo and 1a after operation were close to 0 diopter. The safety index in 1a postoperative was 1.33±0.67 and the effective index was 1.32±0.69. No significant differences were found in IOP and endothelial cell density after surgery comparing to that in preoperative group(P>0.05). None of subjects developed cataract, glaucoma and decompensation of corneal endothelium. The degree of postoperative satisfaction was 100%.

CONCLUSION: ICL V4c implantation is a safe and effective method for correction of high myopia. The visual acuity stabilized 1mo after operation.

Objective : To assess the result of treatment in ClassⅡmalocclusion subdivision with unilateral Forsus appliance. Methods : 23 patients with ClassⅡmalocclusion subdivision were selected, who were treated with Straight wire fixed appliance in combination with unilateral Forsus appliances while another 27 patients were untreated as control group. Lateral cephalographs were taken before and after the comprehensive treatment, and the indicators of dental, skeletal, and soft tissue profile were measured. Results : The Forsus appliance can correct ClassⅡmalocclusion subdivision through distalizing the upper teeth and moving the lower teeth mesially. Midline can be corrected at the same time. There was a statistically significant difference in the amount of tooth movement (P < 0.05). Conclusion Forsus appliance is an effective device for treating ClassⅡmalocclusion subdivision, which can induce significant dental and soft tissue changes.

BACKGROUND: Temperature-responsive magnetic pluronic nanoparticles possess the capacity of drug release controlled by body temperature and can penetrate blood brain barrier.OBJECTIVE: To detect the capacity of magnetic pluronic nanoparticles to carrying ganglioside-1(GM-1) and its capacity of drug release in vivo, as well as its effects on repair of spinal cord injury.DESIGN, TIME AND SETTING: A randomized, controlled, animal experiment was performed at the key laboratories of Beijing Institute for Neuroscience, Capital Medical University and Institute of Process Engineering, Chinese Academy of Sciences between June 2006 and February 2007.MATERIALS: GM-1 loaded magnetic pluronic nanoparticles were prepared by Laboratory of Separation Science and Engineering State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences. GM-1 was provided by Trb Pharma S.A of Argentina.METHODS: Twenty Sprague-Dawiey rats were developed into acute complete spinal cord injury models and were then evenly MAIN OUTCOME MEASURES: Behavior evaluation and quantitative analysis (nerve fibers and glial cells) at 4 weeks post-surgery.were significantly greater in the treatment group than in the remaining 3 groups (P < 0.05), the control groups exhibited greater numbers of nerve fibers than the sham-operation groups, and the control group 2 had higher levels compared with the control compared with the remaining 3 groups (P < 0.05). In the rostral areas, the control groups exhibited higher area ratio of glial cells than the sham-operation group (P < 0.05), and in the caudal areas, control group 2 displayed higher levels compared with the sham-operation group (P < 0.05).CONCLUSION: Magnetic pluronic nanoparticles possess drug-carrying and drug-releasing capacities. GM-1 loaded magnetic pluronic nanoparticies can repair spinal cord injury and promote nerve regeneration.

Myxomas are the most frequent, cardiac benign cardiac tumors which often present with stroke caused by tumorous orthrombotic emboli. The treatment of embolic stroke due to cardiac myxoma is still a clinical and technical challenge. A 61-year-old man who had an embolic stroke in the left middle cerebral artery was admitted to the Third Poeple′s Hospital of Huizhou. The initial National Institutes of Health Stroke Scale (NIHSS) score was 16. He received endovascular thrombectomy after intravenous recombinant tissue plasminogen activator (rt-PA) one hour after stroke onset. No intracranial hemorrhage developed. Pathological study of embolus showed a myxoma. A cardiac mass was found in the left atrium and removed surgically three weeks after stroke. Pathological study of the tumor showed a myxoma. At the one-month follow-up after excision of myxoma, the NIHSS score was 1 and the modified Rankin scale score was 0. No recurrence of embolism occurred after surgical resection. Endovascular thrombectomy after intravenous rt-PA (bridging therapy) for embolic stroke due to cardiac myxoma is safe and effective, and early resection of atrial myxoma can effectively avoid recurrence of cerebral infarction.

OBJECTIVE: To study the mechanism of the anti-tumor effect of Morinda citrifolia (noni). METHODS: The influences of noni juice on cell proliferation, apoptosis, invasion, migration and the activity of AKT/nuclear factor- κ B (NF- κ B) signaling pathway in A549 human lung cancer cells were detected by MTT, cell counting kit-8, colony formation, Annexin V/PI double labeling, transwell, scratch test and immunoblotting assay, respectively. A549 cells were inoculated into the right axilla of nude mice, followed by noni juice treatment. The body weight of the nude mice was weighed, and the tumor volume and weight were measured. Cell proliferation and expression of apoptosis-related proteins were measured by immunohistochemistry, and the activity of NF- κ B signaling pathway was measured by immunoblotting. RESULTS: The in vitro studies showed that noni juice inhibited the A549 cells proliferation, migration and invasion. Noni juice also promoted cells apoptosis in A549 cells. Immunoblotting assay showed that the phosphorylation level of AKT, p50, and STAT3 proteins was inhibited to different extents after noni juice treatment. The in vivo studies showed that noni juice effectively suppressed tumor formation of A549 cells in nude mice. Noni juice treatment inhibited the expression of Ki67, PCNA, and Bcl-2 protein in the tumor; while promoted the expression of caspase-3 protein. Additionally, we also found that noni juice treatment could restrain the activity of AKT/NF- κ B signaling pathway in the tumor tissue. CONCLUSION Noni juice inhibited the proliferation of A549 lung cancer cells, induced apoptosis, and inhibited cell invasion and migration via regulating AKT/NF- κ B signaling pathway.

Objective: To apply the semi-quantitative risk assessment model in the Technical Guidelines for Occupational Health Risk Assessment of Chemical Hazardous Factors in the Workplace to assess the occupational health risk of electroplating enterprises and explore its applicable conditions and characteristics. Methods: Three electroplating enterprises were selected as the research objects. Occupational hygiene survey and hazard factor detection were conducted on the spot. Three semi-quantitative risk assessment methods were used to assess the risk, and the evaluation results were compared. Results: The consistency between the contact index method and the comprehensive index method was strong. The weighted Kappa value was 0.946 and the P value was less than 0.001, but the consistency between the contact ratio method, the contact index method and the comprehensive index method was poor. The weighted Kappa value was 0.345 and 0.391, and the P value was 0.009 and 0.004, respectively. When the contact concentration is less than 50% OELs, the evaluation results of the contact ratio method are lower than those of the exponential method and the comprehensive exponential method. The consistency of the three methods was the highest when the contact concentration (>50%) and (OELs, the results of the contact ratio method are higher than those of the index method and the comprehensive index method. Conclusion Contact ratio method is suitable for occupational health risk assessment under the condition of incomplete occupational health information and for enterprise managers to identify key control points of health risk through self-assessment; Contact index method is suitable for hazard risk assessment of occupational hazards without sampling test conditions or OELs, and pre-assessment of occupational hazards of construction projects without access to analogical test data. The index method is suitable for occupational health risk assessment with available testing data and complete occupational health information.