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Brillouin fiber-optic gyroscope (BFOG) is a fiber ring resonator (FRR)-based ring laser gyroscope with a large dynamic range and high sensitivity. Previous BFOGs operated under simultaneous resonance of the pump and Brillouin laser light in the FRR, resulting in complex control systems. This article introduces an asymmetric prism Mach-Zehnder interferometer coupler (APMZIC)-based FRR system, in which the coupling ratio of pump light is large, while the Brillouin laser resonates in the cavity with a negligible coupling loss, resulting in a simple control system. We analyzed the characteristics of the APMZIC and its combined resonator system both theoretically and experimentally and verified the feasibility of connecting the APMZIC with the resonant cavity of a Brillouin laser. This coupler system is compact, easy to fabricate, highly stable, and exhibits good repeatability, which are necessary for miniaturizing lasers and gyroscopes.
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Objective:To investigate the relationship among five personality factors, negative life events and suicidal tendency of college students, so as to provide reference for college students' suicide prevention.Methods:A cross-sectional survey was conducted among 885 college students in Xi'an city, Shaanxi province. A comprehensive college, a science and engineering college and a liberal arts college were selected respectively. Three questionnaires were applied to all subjects, including big five personality questionnaire, life event questionnaire and scale of adolescents' suicide tendency. Hierarchical regression model was adopted to analyzed the relationship of big five personality traits, negative life events and suicide tendency. Pearson correlation analysis and mediating effect test were conducted by using SPSS 20.0 software.Results:There was no significant interaction between gender and negative life events on suicidal tendency ( β=-0.03, t=-0.96, P>0.05). Conscientiousness( β=-0.12, t=-4.06, P<0.01), neuroticism ( β=0.24, t=7.54, P<0.01), agreeableness( β=-0.15, t=-3.65, P<0.01), extroversion ( β=-0.27, t=-8.56, P<0.01) and openness ( β=-0.12, t=-3.38, P<0.01)in Big Five personality had significant moderating effect on the relationship between negative life events and suicidal tendency. High conscientiousness, high agreeableness, high extroversion and high openness had protective effect on the relationship between negative life events and suicidal ideation. High neuroticism was a risk factor of the relationship between negative life events and suicidal tendency. Conclusion:The five factors of personality are closely related with negative life events and suicidal ideation. The five factors of personality can regulate the relationship between life events and suicidal tendency.
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BackgroundThe 2019 novel coronavirus (2019-nCoV or SARS-CoV-2) has spread more rapidly than any other betacoronavirus including SARS-CoV and MERS-CoV. However, the mechanisms responsible for infection and molecular evolution of this virus remained unclear. MethodsWe collected and analyzed 120 genomic sequences of 2019-nCoV including 11 novel genomes from patients in China. Through comprehensive analysis of the available genome sequences of 2019-nCoV strains, we have tracked multiple inheritable SNPs and determined the evolution of 2019-nCoV relative to other coronaviruses. ResultsSystematic analysis of 120 genomic sequences of 2019-nCoV revealed co-circulation of two genetic subgroups with distinct SNPs markers, which can be used to trace the 2019-nCoV spreading pathways to different regions and countries. Although 2019-nCoV, human and bat SARS-CoV share high homologous in overall genome structures, they evolved into two distinct groups with different receptor entry specificities through potential recombination in the receptor binding regions. In addition, 2019-nCoV has a unique four amino acid insertion between S1 and S2 domains of the spike protein, which created a potential furin or TMPRSS2 cleavage site. ConclusionsOur studies provided comprehensive insights into the evolution and spread of the 2019-nCoV. Our results provided evidence suggesting that 2019-nCoV may increase its infectivity through the receptor binding domain recombination and a cleavage site insertion. One Sentence SummaryNovel 2019-nCoV sequences revealed the evolution and specificity of betacoronavirus with possible mechanisms of enhanced infectivity.
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Objective@#To assess feasibility and clinical effect of 3D printed prosthesis in instant rehabitation of Brown Ⅱ maxilla defect.@*Methods@#Five patients with maxillary primary tumor or malignant tumor involving maxillary bone admitted from August 2016 to April 2017 were treated.Before surgery, surgical guide template and prosthesis was designed and created with digital surgery technique. Surgery was performed under guidance of surgical template and checked with surgical navigation. Prosthesis was also placed to repair Brown Ⅱ maxilla defect instantly in surgery.Two weeks after surgery, CBCT examination was taken and compared to the pre-operative CBCT images to evaluate deviation and assess precision of surgery. One month after surgery, 3D photograph was taken to compare intercommissural width, differences of bilateral lip height and maximum distance between healthy and affected sides of lip, nasolabial angles, skewed degree of mouth corner, volume variation and superficial area variation of the lip before and after insertion of prosthesis. All data ware analyzed with SPSS 21.0 using the Mann-Whitney U test for non parametric test.@*Results@#Prosthesis was inserted during 20 minutes in all 5 included patients with good occlusion. The suture was removed two weeks after surgery.The wound healed well without infection. 5 patients had no recurrence of tumor during follow-up.Maximum deviation between actual and virtual surgery was(3.75±0.87) mm, minimum deviation was 0 mm, and average deviation was(0.35±0.08) mm.The difference of bilateral lip height was(2.66±1.52) mm and(0.46±0.49) mm before and after insertion of prosthesis(P=0.016). The skewed degree of mouth corner was(3.43±1.70)°and(1.98±1.24)°before and after insertion of prosthesis(P=0.047). The maximum distance between healthy and affected sides of lip were(5.75±3.66) mm and(2.19±1.14) mm before and after insertion of prosthesis(P=0.009). The above differences were statistically significant.No significant differences were found between nasolabial angles and intercommissural width (P=0.251, 0.251). Volume variation before and after insertion of prosthesis was(5.54±2.50) cm3and superficial area variation was (66.42±21.18) cm2.@*Conclusions@#3D printed prosthesis can instantly repair Brown Ⅱ maxilla defect, retain facial appearance and dentition and obtain good effect.
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Aim To investigate the effect of phenyle-thanol glycosides from Cistanche tubulosa(CPhGs) on the proliferation and activation of rrPDGF-BB induced HSC and their target points for resisting hepatic fibro-sis,to elucidate the molecular mechanism in molecular level, and provide basic data for the further develop-ment of new drugs. Methods HSCs were cultivated by CPhGs with different concentrations ( 0 , 3. 91 , 7. 81 , 15. 63 , 31. 25 , 62. 50 , 125. 00 , 250. 00 , and 500 mg ·L-1 ) and IC50 of CPhGs was determined. CPhGs with different concentrations ( 25 , 50 , 75 , 100 mg · L-1 ) were selected, and after the cells were stimulated with rrPDGF-BB, cell proliferation was determined by MTT. ERK1/2 ,α-SMA, c-fos, c-jun and Collagen I mRNA and Erk1/2 ,P-Erk1/2 and CollagenⅠprotein ex-pressions were assayed by RT-PCR and Western blot. Results CPhGs of ( 50 ~100 ) mg · L-1 concentra-tions groups could effectively inhibit rrPDGF-BB-medi-ated proliferation(P0. 05 ) . CPhGs of ( 25 ~100 ) mg · L-1 concentrations groups could inhibit ERK1/2 ,α-SMA,c-fos, c-jun and CollagenⅠmRNA levels, and also ob-viously inhibited Erk1/2 ,P-Erk1/2 and Collagen Ⅰ pro-tein expression on HSC. Conclusions CPhGs has the protective effect against hepatic fibrosis. The mecha-nism of this process may involve the interference with PDGF/ERK1/2 signaling pathway and inhibiting the activation and proliferation of HSC.
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OBJECTIVE To study the anti-fibrotic effect of Cistanche phenylethanoid glycosides (CPhG) in bovine serum albumin (BSA)-induced liver fibrosis in rats and its possible mechanism METHODS Seventy-five SD rats were randomly divided into six groups:normal control(distilled water-treated),model(BSA-treated),positive drug〔BSA-treated+compound Biejiarangan tablets(BJRG) 0.6 g·kg-1〕,and BSA-treated+CPhG(0.125,0.25 and 0.5 g·kg-1)groups. There were thirteen rats in each BSA-treated+CPhG(0.125,0.25 and 0.5 g·kg-1)group and twelve rats in other groups. Subcutaneous injection and tail vein injection of BSA immunity were used to induce the rat liver fibrosis model. Meanwhile, different therapeutic drugs were ig adminstered to rats. After the experimental period,rats were fasted for 12 h prior to 10%chloral hydrate administration and immediately euthanized. The liver was weighed to calculate the liver index. Glutamic-pyruvic transaminase (GPT),glutamic-oxalactic transaminase (GOT),alkaline phosphatase(ALP),total protein(TP)and albumin(ALB)were evaluated by the Mind-Ray automatic biochemical analyzer. The density of hydroxyproline (HyP) in liver tissues was determined using a spectrophotometric method according to the kit′s instructions. Histopathological changes and expressions of typeⅠ and typeⅢcollagens in liver tissues were also determined by immunohisto?chemical staining. RESULTS Compared with the normal control group,collagen fibers of liver tissues in the model group extended their links and enveloped the entire lobule,causing lobular structural damage and the formation of pseudolobules. The liver index(P<0.05),GPT,GOT,ALP,TP and ALB serum levels(P<0.05),HyP content(P<0.01)were significantly increased,so was the expression of typeⅠcollagens and typeⅢcollagens(P<0.01)in the model group. Compared with model group,various doses (0.125,0.25 and 0.5 g · kg-1) of CPhG significantly reduced the BSA-induced elevation of the liver index;GPT,GOT,ALP,TP and ALB serum levels(P<0.05),and HyP content decreased(P<0.01);the morphology of the pathological tissue sections was close to that of the normal control group,and CPhG significantly reduced the expression of two types of collagens(P<0.01). CONCLUSION CPhG can significantly reduce the degree of BSA-induced liver fibrosis in rats. The mechanism may be associated with down-regulation of two types of collagens and suppression of the activation of hepatic stellate cells.
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The innovative research on the platform of the guided-navigating surgery of bone and joints consists of four basic function modules and three technical-related systems. Through this research the functional modules will be constructed by orthopedic specialists and software experts who have made jointly efforts based on the transitional medicine to develop a new software for guided-navigating surgery of bone and joints suitable for people in Asia and for its application in medical treatment.
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Humanos , Desenho de Equipamento , Procedimentos Ortopédicos , Métodos , Software , Cirurgia Assistida por Computador , MétodosRESUMO
Objective To apply the three-dimensional pre-operative simulation and intra-operative real-time navigation in the reconstruction of old maxillofacial fractures so as to increase the surgical precision. Methods Six patients with old maxillofacial fractures were enrolled, and the diagnosis of unilateral old maxillofacial fractures was confirmed by clinical and imaging examinations. Virtual three-dimensional skull models were reconstructed from pre-operative CT images. The fractured bone was moved or rotated, and was reposed in a desired site according to the mirrored part from the healthy side. After patient-to-image registration, the surgical instruments and patients were tracked in real-time by optical tracking system during operation, and in this way the maxillofacial fractures were reposed satisfactorily guided by the virtual image. Results Three-dimensional simulation before operation and real-time navigation of patients and instruments during operation were realized. The error of registration was less than 1 mm. The post-operative CT examinations of these six patients revealed that the fracture reposition was same to the pre-operative planning, and the difference between them was less than 1.5 mm. The operations were minimally-invasive, with no complications. Conclusion Computer-aided surgical simulation and navigation system can effectively increase the surgical precision of reconstruction of old maxillofacial fractures.
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The conventional design and fabrication of the dental splint (in orthognathic surgery) is based on the preoperative planning and model surgery so this process is of low precision and efficiency. In order to solve the problems and be up to the trend of computer-assisted surgery, we have developed a novel method to design and fabricate the dental splint--computer-generated dental splint, which is based on three-dimensional model simulation and rapid prototype technology. After the surgical planning and simulation of 3D model, we can modify the model to be superior in chewing action (functional) and overall facial appearance (aesthetic). Then, through the Boolean operation of the dental splint blank and the maxillofacial bone model the model of dental splint is formed. At last, the dental splint model is fabricated through rapid prototype machine and applied in clinic. The result indicates that, with the use of this method, the surgical precision and efficiency are improved.
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Humanos , Desenho Assistido por Computador , Modelos Dentários , Imageamento Tridimensional , Arcada Osseodentária , Cirurgia Geral , Modelos Anatômicos , Placas Oclusais , Desenho de Aparelho Ortodôntico , Métodos , Cirurgia Assistida por Computador , MétodosRESUMO
<p><b>OBJECTIVE</b>To evaluate whether or not administration of vitamin B(6) (vitB(6)) has preventive effects on cleft palate formation.</p><p><b>METHODS</b>On the 14, 15 day of gestation, the pregnant rats were treated with administration of vitB(6) (10 mg/kg weight im) before and simultaneously with dexamethason (DEX). Compared the palatal cleft incidence of their fetuses with those whose mother were given DEX only.</p><p><b>RESULTS</b>Treatment with administration of vitB(6) before and simultaneously with DEX, the palatal cleft incidence of subject group fetuses (32.35%) was significantly less than that given DEX only (64.52%). The proportion of the palatal cleft type was also changed significantly.</p><p><b>CONCLUSIONS</b>VitB(6) decrease both the incidence and the severity of cleft palate induced by DEX in rats, which indicates VitB(6) may have preventive effects on cleft palate formation.</p>
