Objective:To analyze the stress distribution in the fixed denture of edentulous maxilla supported by 6 implants at different implant position.Methods:The skull of a volunteer with total anodontia and moderate alveolar bone absorption was scanned by CBCT.Computer software,Abaqus 6.9,Geomagic Studio 12,and Mimics10.01,were applied for data processing and reconstruction of a 3D finite element model of implant-supported fixed denture with 6 implants in different location;and then,the stress distribution was analisized.Results:3D finite element model of edentulous maxillary implant-supported fixed bridge with good geometric similarity was established.The implant neck bone interface stress value of the distal of the implant fixed bridge at the molar area,the stress concentration area,was the maximum.The main stresses were compressive in the cortical bone adjacent to the mesial or the distal implants.The shift of the denture decreased from anterior to posterior.In model Ⅰ (implants at 13,15,17,23,25 and 27) distal cantilever was not used and the stress distribution was the evenest.Conclusion:The implant position at 13,15,17,23,25 and 27 of edentulous maxillary 6-implants-supported fixed bridge was the best for the stress distribution among the 8 models.

Objective To observe the cognitive function and its related factors in patients with essential epilepsy.Methods The cognitive function of 70 essential epilepsy patients (epilepsy group) and 40 healthy controls(control group) were evaluated by means of Wechsler Intelligence Scale for Adult-Chinese (WAIS-RC).The relation between the cognitive dysfunction and its related factors were analyzed.Results The scores of performance intelligence quotient,verbal intelligence quotient,full intelligence quotient in epilepsy group were significantly lower than those in control group [(98.06 ± 15.24) scores vs.(113.80 ± 12.14) scores,(98.09 ± 16.06) scores vs.(120.65 ± 11.28) scores,(98.06 ± 15.80) scores vs.(119.42 ± 11.85) scores] (P ＜ 0.01).The scores of 11 numbers of rating scales were significantly lower than those in control group (P ＜ 0.01).The factors related to the cognitive function were education level,age numbers,duration of the disease,frequency of seizures attack before medication,the duration of seizures and the quantity of antiepileptics.Conclusions Many of the essential epilepsy patients have cognitive function deficit.The cognitive condition of essential epilepsy patients should be pay more attention and reduce the dangerous factors in order to improve the life quality.

Objective To study the microscopic changes of white matter and the relationship between white matter changes and cognitive impairment in Alzheimer's disease (AD) using voxel-based analysis of DTI. Methods Thirty-sev?en patients with probable AD,and 32 normal controls(NC) were all examined by MMSE scores, and underwent a diffusion tensor imaging. The value of FA changes and the correlations between FA and MMSE scores were investigated. Results FA reduction was detected in the right frontal, temporal and parietal lobes as well as the thalamus, the bilateral cingu?lum, corpus callosum, precuneus, inferior parietal lobule, inferior patieto gyrus, supramaginal gyrus and hippocampus in AD. FA values in the right cingulum, left corpus callosum, left inferior temporal gyrus and the bilateral inferior parietal lobule, inferior patieto gyrus and precuneus were significantly decreased in AD than in the health control groups (P<0.05, FWE corrected). There was a positive correlation between the values of FA and MMSE scores(P<0.001,uncorrect?ed). Conclusion AD patients have significant reduction of FA values in the specific regions. There is a positive correla?tion between white matter changes and impairments of cognitive function.

Objective To investigate effectiveness of meta-cognitive intervention on aged people with middle depression. Methods Geriatrist Depression Scale(GDS) and Hamilton's Depression Scale ( HAMD-17 ) were used to screen out 70 aged people with middle depression from 850 retired soldier cadres dwelling in cpla dalian sanitarium. They were randomly divided into study group( n = 35 ) and control group( n = 35 ). The experimental group received meta-cognitive intervening and general nursing care for 8 weeks, while the control group only received general nursing care for 8 weeks. HAMD-17, GDS, global assessment scale(GAS) and the Metacognitions Questionnaire(MCQ-30) were administered both at the start and the end of the 8th week. Results The total scores in HAMD and GDS were decreased significantly in study group ( HAMD: ( 1 1.54 ± 2.50 ) vs ( 13.06 ±2.82),t= -2.378, P=0. 020;GDS:(12.51 ±2.43) vs (16.06 ±2.48), t= -6. 031, P=0. 000;GAS:(77.71 ±3.03) vs (75.63 ± 3.24), t = 2. 785, P = 0. 007 ). At the end of 8th week, the MCQ total score was significantly decreased in study group (38.69 ± 4. 17,81.37 ± 5.98, t = 34. 652, P ＜ 0. 01 ). Conclusion For aged people with middle depression,good effects are got by the meta-cognitive intervening technique and meta-cognitive intervening technique improve the meta-cognitive level of aged people with middle depressive mood.

Objective To study the computed tomography(CT)manifestations of involvement of bridging septa in the perirenal space(BSPS)during acute pancreatitis(AP)and its correlation with extrapancreatic inflam-mation on abdominal computed tomography(EPICT)score. Methods 106 patients with acute pancreatitis were included in this study. Emphasis was placed on CT findings of BSPS and the EPICT score in all the patients. Results The EPICT score was 4 to 7 in 67 patients,and the EPICT score was 0 to 3 in 39 patients. BSPS involve-ment was shown in all the patients. The left or right BSPS involved in 102 patients and 98 patients,respectively. Thickening of the BSPS was shown as strip shadow with slightly higher density and hazy border;fluid collection of the BSPS was shown as liquid density with hazy border. The involvement of BSPS showed a statistically significant association with the EPICT score in the AP patients(r=0. 703,P<0.01). Conclusion BSPS involved by acute pancreatitis is shown as a strip shadow with slightly higher density or as liquid density with hazy border on CT images, reflecting the severity of the acute pancreatitis.

Objective To evaluate the risk of occupational noise-induced hearing loss in workers in a metal tool manufacturing enterprise, and to carry out risk classification and risk management. Methods A total of 91 male noise-exposed workers from a metal tool manufacturing enterprise in Hebei Province were selected as the research subjects using the convenience sampling method. The work site survey on occupational health and the measurement on individual noise exposure level were carried out. The ISO 1999：2013 (E) Acoustics-Estimation of Noise-Induced Hearing Loss was used to predict the risk of high frequency hearing loss (HFHL) and occupational noise-induced deafness (ONID). The risk classification and risk management were conducted using the WS/T 754-2016 Guideline for Risk Management of Occupational Noise Hazard (hereinafter referred to as WS/T 754-2016). Results The individual noise exposure intensity of workers in the six work sites of the enterprise, including blade workers, sheet punching workers, roller forging workers (hoe), hole punching workers, roller forging workers(shovels), and carpenters, exceeded the national occupational exposure limit, with the maximum volume of 91.2-104.1 dB(A). Among these workers, the positions of blade workers, sheet punching workers, and roller forging workers (hoe) were identified as critical control points for noise hazards in the enterprise. The detection rates of HFHL and ONID were 24.2% and 8.8%, respectively. The risk prediction results showed that, based on the actual noise exposure time and age of the study subjects, the risk of HFHL and ONID ranged from 1.7%-48.8% and 0.0%-29.5%, respectively. The risks of HFHL caused solely by occupational noise exposure when working up to 50.0, 55.0, and 60.0 years of age were 11.4% to 64.7%, 16.4% to 65.1%, and 17.2% to 59.4%, respectively. The risks of ONID caused solely by occupational noise exposure were 0.0% to 45.5%, 4.2% to 51.7%, and 5.9% to 57.4%, respectively. Except for the blade workers, the predicted median of potential noise-induced permanent threshold shifts (NIPTS) in the other five positions were lower than the actual values of NIPTS, with the difference ranging from 3.0-28.3 dB, and 73.3% of them underestimated by 10.0 dB or more. Conclusion The outcome of noise exposure on the hearing of workers in this enterprise are severe. Risk management should be conducted according to the WS/T 755-2016.

Opioid analgesics are currently known as the best analgesics. However， toxicity and side effects such as constipation， tolerance and addiction severely limit their clinical application. With the in-depth understanding of the signal transduction mechanism of opioid receptors and the continuous advancement of drug design technology， researchers have managed to develop many promising new methods to get low-toxic and more efficient opioid analgesics， which are different from the traditional morphine skeleton structure modifications. This article focuses on three new research strategies of G-protein biased activation，“ one drug-multiple targets” and peripheral activation. The basic principles of relative separation of analgesic activity and adverse drug reaction by each strategy are introduced， and the latest research progress of representative drugs is briefly reviewed. Among them， the recently approved novel opioid analgesics oliceridine and tegileridine are G-protein biased μ-opioid receptor agonists， Cebranopadol is a typical “one drug-multiple targets” analgesic， and NFEPP is a representative drug of peripheral opioid receptor agonists. The above several strategies complement each other and provide reference for the development of new opioid analgesic drugs.