여대생의 인유두종 바이러스 및 인유두종 바이러스 백신 관련 지식과 예방접종 실태와의 상관관계

Xu, Meiling,김현지,이희수,이윤지,한동연,박소영,엄효윤,최정민,홍서진,홍예림,이경은,이혜림 이화여자대학교 간호과학대학 2017 이화간호학회지 Vol.- No.51

Purpose: Human Papillomavirus (HPV) vaccination is readily available, but immunization rate is minimal. Lack of knowledge concerning the HPV infection and vaccine is expected as the primary reason. The correlation between knowledge levels and vaccination will provide applicable guidelines for successful interventions. Method: 309 female university students have completed surveys September 2016, reporting of HPV infection knowledge, HPV vaccine knowledge, source of knowledge, and attitudes concerning vaccination. Result: HPV infection and vaccine knowledge levels were both suboptimal(9.57±1.84, 7.59±1.58), and the Internet(16.2%) was recognized as the most generally used means of obtaining information on the HPV vaccine. However, vaccination rates were reported to be low(28.2%), with lack of information(46.6%) hindering immunization. Correlations were found between HPV infection knowledge and cervical cancer insight, but the correlations between knowledge levels and vaccination rates were insignificant. Conclusion: Prior information on cervical cancer had an effect on the knowledge levels of HPV infection, but other factors were insignificant. Lack of information on the HPV vaccine was speculated, thus programs should focus on accessibility and effectiveness.

Constraints on kinematic models from the latest observational data

Lu, J.,Xu, L.,Liu, M. North-Holland Pub. Co 2011 Physics letters: B Vol.699 No.4

Kinematical models are constrained by the latest observational data from geometry-distance measurements, which include 557 type Ia supernovae (SNIa) Union2 data and 15 observational Hubble data. Considering two parameterized deceleration parameter, the values of current deceleration parameter q<SUB>0</SUB>, jerk parameter j<SUB>0</SUB> and transition redshift z<SUB>T</SUB>, are obtained. Furthermore, we show the departures for two parameterized kinematical models from ΛCDM model according to the evolutions of jerk parameter j(z). Also, it is shown that the constraint on jerk parameter j(z) is weak by the current geometrical observed data.

Understanding of the capacity contribution of carbon in phosphorus-carbon composites for high-performance anodes in lithium ion batteries

Xu, J.,Jeon, I. Y.,Ma, J.,Dou, Y.,Kim, S. J.,Seo, J. M.,Liu, H.,Dou, S.,Baek, J. B.,Dai, L. Springer Science + Business Media 2017 Nano research Vol.10 No.4

<P>Phosphorus has recently received extensive attention as a promising anode for lithium ion batteries (LIBs) due to its high theoretical capacity of 2,596 mAh.g(-1). To develop high-performance phosphorus anodes for LIBs, carbon materials have been hybridized with phosphorus (P-C) to improve dispersion and conductivity. However, the specific capacity, rate capability, and cycling stability of P-C anodes are still less than satisfactory for practical applications. Furthermore, the exact effects of the carbon support on the electrochemical performance of the P-C anodes are not fully understood. Herein, a series of xP-yC anode materials for LIBs were prepared by a simple and efficient ball-milling method. 6P-4C and 3P-7C were found to be optimum mass ratios of x/ y, and delivered initial discharge capacities of 1,803.5 and 1,585.3.mAh.g(-1), respectively, at 0.1 C in the voltage range 0.02-2 V, with an initial capacity retention of 68.3% over 200 cycles (more than 4 months cycling life) and 40.8% over 450 cycles. The excellent electrochemical performance of the 6P-4C and 3P-7C samples was attributed to a synergistic effect from both the adsorbed P and carbon.</P>

Impact of low dose atorvastatin on development of new-onset diabetes mellitus in Asian population: Three-year clinical outcomes

Park, J.Y.,Rha, S.W.,Choi, B.,Choi, J.W.,Ryu, S.K.,Kim, S.,Noh, Y.K.,Choi, S.Y.,Akkala, R.G.,Li, H.,Ali, J.,Xu, S.,Ngow, H.A.,Lee, J.J.,Lee, G.N.,Kim, J.,Lee, S.,Na, J.O.,Choi, C.U.,Lim, H.E.,Kim, J.W Elsevier/North-Holland Biomedical Press 2015 INTERNATIONAL JOURNAL OF CARDIOLOGY Vol.184 No.-

Background: High dose atorvastatin is known to be associated with new onset diabetes mellitus (NODM) in patients with high risk for developing diabetes mellitus (DM). However, low dose atorvastatin is more commonly used as compared with high dose atorvastatin. The aim of this study is to investigate the impact of low dose atorvastatin (LDA, 10mg or 20mg) on the development of NODM up to three years in Asian patients. Methods: From January 2004 to September 2009, we investigated a total of 3566 patients who did not have DM. To adjust for potential confounders, a propensity score matching (PSM) analysis was performed using the logistic regression model. After PSM (C-statistics: 0.851), a total of 818 patients (LDA group, n=409 patients and control group, n=409 patients) were enrolled for analysis. Results: Before PSM, the cumulative incidence of NODM (5.8% vs. 2.1%, p<0.001), myocardial infarction (0.5% vs. 0.1%, p-value=0.007), and major adverse cardio-cerebral event (MACCE, 1.8% vs. 0.7%, p-value=0.012) at three-years were higher in the LAD group. However, after PSM, there was a trend toward higher incidence of NODM (5.9% vs. 3.2%, p=0.064) in the LDA group, but the incidence of MACCE (1.2% vs. 1.5%, p-value=1.000) was similar between the two groups. In multivariable analysis, the LDA administration was tended to be an independent predictor of NODM (OR: 1.99, 95% CI: 1.00-3.98, p-value 0.050). Conclusions: In this study, the use of LDA tended to be a risk factor for NODM in Asian patients and reduced clinical events similar to the control group. However, large-scale randomized controlled trials will be needed to get the final conclusion.

Five-year clinical outcomes in patients with significant coronary artery spasm: A propensity score-matched analysis

Choi, B.G.,Park, S.H.,Rha, S.W.,Park, J.Y.,Choi, S.Y.,Park, Y.,Xu, S.,Ngow, H.A.,Ali, J.,Li, H.,Kim, J.B.,Lee, S.,Na, J.O.,Choi, C.U.,Lim, H.E.,Kim, J.W.,Kim, E.J.,Park, C.G.,Seo, H.S.,Oh, D.J. Elsevier/North-Holland Biomedical Press 2015 INTERNATIONAL JOURNAL OF CARDIOLOGY Vol.184 No.-

Background: Coronary artery spasm (CAS) is known to be a risk factor of acute coronary syndrome and angina pectoris. However, there is no currently available data with larger study population regarding long-term clinical outcomes of CAS in real world clinical practice. Objectives: We evaluated the prevalence of CAS and the impact of CAS on 5-year clinical outcomes in a series of Asian CAS patients documented by intracoronary acetylcholine (Ach) provocation test. Methods: A total of 1413 consecutive patients without significant coronary artery disease (CAD) who underwent Ach provocation test between Nov. 2004 and Oct. 2008 were enrolled. Significant CAS was defined as >70% of narrowing by incremental intracoronary injection of 20, 50 and 100μg. Patients were divided into two groups based on the presence of significant CAS (the non-CAS group: n=640, the CAS group; n=773). To adjust potential confounders, a propensity score matched (PSM) analysis was performed using the logistic regression model. Results: A total of 54.7% (773/1413) patients were diagnosed as CAS documented by Ach provocation test. After PSM analysis, 2 propensity-matched groups (451 pairs, n=902, C-statistic=0.677) were generated. Despite of similar incidence of individual hard endpoints including mortality, myocardial infarction and revascularization, the CAS group showed the higher trend of recurrent angina requiring follow up angiography than the non-CAS group up to 5years (HR; 1.56, 95% C.I.; 0.99-2.46, p=0.054). Conclusions: The prevalence of CAS was 54.7%. Although the cumulative incidence of recurrent angina requiring follow up coronary angiography seems to be increased up to 5years in CAS patients, CAS patients was not associated with major individual and composite clinical outcomes such as mortality, MI, PCI, CVA with optimal medical therapy as compared with patients without CAS.

WALL-WETTING MODEL BASED METHOD FOR AIR-FUEL RATIO TRANSIENT CONTROL IN GASOLINE ENGINES WITH DUAL INJECTION SYSTEM

J. ZHANG,T. SHEN,G. XU,J. KAKO 한국자동차공학회 2013 International journal of automotive technology Vol.14 No.6

Modern gasoline engines with dual injection system improve combustion efficiency by using the two injection commands simultaneously. Due to the different dynamics in the two injection paths, the transient air-fuel ratio (A/F)performance when the injection authority is changed remarkably affects the emission performance of the engine system. For this kind of engines, this paper proposes a model-based design approach that gives a dynamic feedforward compensation for achieving good transient A/F performance. Actually, this work centers on discussing the mean-value model parameters for characterizing the wall-wetting phenomenon when the port injection authority is changed under different engine operation conditions. Moreover, from the view of practice, taking into account the event-based physics of the engine system, significant calibration for the model parameters that are employed for achieving the feedforward compensation is investigated experimentally. Finally, experimental validation results demonstrate the improvement of the transient A/F performance by using the control scheme.

Formation of Al2O3 coatings on NiTi alloy by micro-arc oxidation method

J.L. Xu,F. Liu,F.P. Wang,D.Z. Yu,L.C. Zhao 한국물리학회 2009 Current Applied Physics Vol.9 No.3

Rough and porous Al2O3 coatings containing Ca and P were prepared on Ti–50.8 at.% Ni alloy by micro-arc oxidation (MAO) technique. The icrostructure, elemental and phase composition of the coatings were investigated by scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS) and thin-film X-ray diffraction (TF-XRD). The thickness of the coatings was measured by eddy current coating thickness gauge. The corrosion resistance and the nickel release of the coated and uncoated samples were examined by potentiodynamic polarization tests and immersion tests in Hank’s solution, respectively. The results show that the coatings are mainly composed of γ-Al2O3 crystal phase. The Ni content of the coatings is about 3.5 at.%, which is greatly lower than that of NiTi substrate. With increasing treatment time, both thickness and roughness of the coatings increase. The corrosion resistance of the coated samples is about two orders of magnitude higher than that of the uncoated NiTi alloy. The concentration of Ni released from coated NiTi samples is much lower than that of uncoated NiTi sample. It can be reduced in the factor of oneseventh compared with the uncoated NiTi sample after 3 weeks immersion in Hank’s solution. Rough and porous Al2O3 coatings containing Ca and P were prepared on Ti–50.8 at.% Ni alloy by micro-arc oxidation (MAO) technique. The icrostructure, elemental and phase composition of the coatings were investigated by scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS) and thin-film X-ray diffraction (TF-XRD). The thickness of the coatings was measured by eddy current coating thickness gauge. The corrosion resistance and the nickel release of the coated and uncoated samples were examined by potentiodynamic polarization tests and immersion tests in Hank’s solution, respectively. The results show that the coatings are mainly composed of γ-Al2O3 crystal phase. The Ni content of the coatings is about 3.5 at.%, which is greatly lower than that of NiTi substrate. With increasing treatment time, both thickness and roughness of the coatings increase. The corrosion resistance of the coated samples is about two orders of magnitude higher than that of the uncoated NiTi alloy. The concentration of Ni released from coated NiTi samples is much lower than that of uncoated NiTi sample. It can be reduced in the factor of oneseventh compared with the uncoated NiTi sample after 3 weeks immersion in Hank’s solution.

Dynamics of kinetic geodesic-acoustic modes and the radial electric field in tokamak neoclassical plasmas

Xu, X.Q.,Belli, E.,Bodi, K.,Candy, J.,Chang, C.S.,Cohen, R.H.,Colella, P.,Dimits, A.M.,Dorr, M.R.,Gao, Z.,Hittinger, J.A.,Ko, S.,Krasheninnikov, S.,McKee, G.R.,Nevins, W.M.,Rognlien, T.D.,Snyder, P.B. International Atomic Energy Agency 2009 Nuclear fusion Vol.49 No.6

<P>We present edge gyrokinetic simulations of tokamak plasmas using the fully non-linear (full-<I>f</I>) continuum code TEMPEST. A non-linear Boltzmann model is used for the electrons. The electric field is obtained by solving the 2D gyrokinetic Poisson equation. We demonstrate the following. (1) High harmonic resonances (<I>n</I> > 2) significantly enhance geodesic-acoustic mode (GAM) damping at high <I>q</I> (tokamak safety factor), and are necessary to explain the damping observed in our TEMPEST <I>q</I>-scans and consistent with the experimental measurements of the scaling of the GAM amplitude with edge <I>q</I><SUB>95</SUB> in the absence of obvious evidence that there is a strong <I>q</I>-dependence of the turbulent drive and damping of the GAM. (2) The kinetic GAM exists in the edge for steep density and temperature gradients in the form of outgoing waves, its radial scale is set by the ion temperature profile, and ion temperature inhomogeneity is necessary for GAM radial propagation. (3) The development of the neoclassical electric field evolves through different phases of relaxation, including GAMs, their radial propagation and their long-time collisional decay. (4) Natural consequences of orbits in the pedestal and scrape-off layer region in divertor geometry are substantial non-Maxwellian ion distributions and parallel flow characteristics qualitatively like those observed in experiments.</P>

Stability of multi-step flexural-shear plates with varying cross-section

Xu, J.Y.,Li, Q.S. Techno-Press 2003 Structural Engineering and Mechanics, An Int'l Jou Vol.16 No.5

In this paper, multi-story buildings with shear-wall structures and with narrow rectangular plane configuration are modeled as a multi-step flexural-shear plate with varying cross-section for buckling analysis. The governing differential equation of such a plate is established. Using appropriate transformations, the equation is reduced to analytically solvable equations by selecting suitable expressions of the distribution of stiffness. The exact solutions for buckling of such a one-step flexural-shear plate with variable stiffness are derived for several cases. A new exact approach that combines the transfer matrix method and closed from solution of one-step flexural-shear plate with continuously varying stiffness is presented for stability analysis of multi-step non-uniform flexural-shear plate. A numerical example shows that the present methods are easy to implement and efficient.

Pulse energy comparison based on on/off time of a R-C mode EDM pulse power generator

J. L. Chen(천지에린),M. R. Xu(쉬모란),G. C. Park(박건철),T. J. Ko(고태조) 한국기계가공학회 2021 한국기계가공학회 춘추계학술대회 논문집 Vol.2021 No.6