Crystal power/epoxy resin composite was made with refined crystal power as filling material in different composition. The shearing strength and coefficient of thermal expansion of the crystal powder/epoxy resin composite was studied. The sectional morphology was observed under a scanning electron microscope. The results of the study indicate that the shearing strength of crystal powder/epoxy resin composite is improved while the coefficient of thermal expansion decreases with increase of the amount of crystal powder, and a well-proportioned three-dimensional structure is obtained. The augmentation of shearing strength exhibits no linear relationship to the amount of crystal powder, and there is an optimal amount for crystal powder filling. The coefficient of thermal expansion is decreased with increase of crystal powder filling, and three-dimensional structure optimization exhibits the' similar inflexion.

The left ventricular twist was evaluated by 2-dimensional ultrasound speckle-tracking imaging (STI) in 50 patients with hypertension with normal geometric left ventricle (LV) and 45 normal subjects as control group. The mean value of LV rotation was obtained at each plane using STI. LV twist and twist velocity were defined as apical rotation/rotation rate relative to the base respectively. To adjust the intersubject differences in heart rates, the time sequence were normalized. The results showed that peak twist developed near the end of systole. Peak LV twist was significantly higher in patients with hypertension than normal controls (P<0.001). The diastolic untwisting mainly occurred in early diastole ( approximately 38%). Compared with normal controls, untwisting rate (Untw R) in patients with hypertension was significantly reduced (P<0.001), and untwisting half-time (UHT) was significantly delayed (P<0.05). This study demonstrated that STI has a potential ability to evaluate the early change of heart function in patients with hypertension by measuring the twist of LV.
Cardiology/*methods ; Case-Control Studies ; Diastole ; Echocardiography/*methods ; Heart/physiopathology ; Heart Ventricles/*pathology ; Hypertension/*pathology ; Image Processing, Computer-Assisted/methods ; Reproducibility of Results ; Systole

Objective To investigate the performance of left ventricular torsion (LVtor) or twist with cardiac dysfunction patients by speckle tracking imaging (STI). Methods Standard left ventricular short-axis views images were acquired by rountine two-dimensional echocardiography in thirty-two healthy humans and twenty-four patients with cardiac dysfunction. LVtor angle,left ventricular rotation (LVrot) angle,the peak value and time of LVtor and LVrot were measured respectively. The data were compared and analyzed between the two groups. Results Compared with normal group,the peak of LVtor and LVrot angle was decreased in cardiac dysfunction group at both apical and basal planes (P<0.05). The peak time of LVtor in patients with cardiac dysfunction was delayed (P<0.05). The peak time of clockwise rotation at the apical level segments was longer than control group (P<0.05). Conclusions There is a temporal sequence difference of left ventricular rotation between basal and apical planes during left ventricular contraction and decreased LVtor has been demonstrated to influence left ventricular function.

Objective To evaluate the changes of left ventricular (LV) bulk rotation and untwisting in transplanted hearts using 2-dimensional speckle tracking imaging(STI).Methods Basal and apical LV short-axis images were acquired in 15 heart transplant recipients 3 months post surgery(HT group) and 56 healthy control subjects.Basal and apical rotation versus time profiles were drawn using 2-dimensional STI software.Appropriate values were chosen from the dataset obtained and compared between two groups.Results ①Compared with the control group,the heart rate,anterior-posterior diameter of left atrium,enddiastolic interventricular septum thickness,left ventricular posterior wall thickness,isovolumic relaxation time and E/e ratio were significantly increased,e and a values were decreased significantly in HT group (P ＜ 0.05).② No significant difference was noticed in the peak degrees of LV bulk rotation,the degrees of LV bulk rotation at the time of aortic valve closure and mitral valve opening (P =0.700,0.984,0.495,respectively) between 2 groups.In both groups,systolic rotation reached its maximum at end-systole [(96.1 ± 8.4) ％ in HT group vs (100.5 ± 6.3) ％ in control group,P =0.065].③Significant decreases in untwisting rate and trend untwisting variables were observed in the HT group(P ＜0.001).Conclusions 3 months after transplanted,left ventricular bulk rotation of cardiac allografts remained normal,and significant decreases in both untwisting rate and trend untwisting variables showed that the diastolic function of cardiac allografts was impaired.

Objective To understand the status of implementation of invasive ventilator circuit changes in ICU nurses at the 3A general hospitals in Shanxi Province, and mastering and demand of related knowledge of ICU nurses, and by this discuss the possible causes of execution inconsistency in invasive ventilator circuit changes interval so as to provide a clear basis for the specification and circuit changes. Methods After a review of relevant literature at home and abroad as well as expert consultation, a self-designed questionnaire was established, take two ways of on-site issuance and mailing, ICU nurses from 13 hospitals were selected randomly to investigate about the invasive circuit changes interval in Shanxi Province. Results A total of 724 nurses from 34 ICU of 13 hospitals were surveyed. A unified circuit changes interval of ICU accounted for 73.5% (527/717). ICU nurses currently provisions and practical implementation of invasive ventilator circuit changes interval tend to 7 d. Different ICU provisions and ICU nurses actual implementation of circuit change were significantly different (χ2=24.839, 35.760, P < 0.01). Conclusions Hospitals should choose the right way to strengthen the ICU nurses invasive ventilator circuit changes training interval and knowledge, to develop the term for their own security environment, thereby reduce the workload of nurses, reduce medical costs and improve care service quality.

Objective:To analyze the EGFR gene polymorphism in the non-small cell lung (NSCLCs) cancer in southern of Shaanxi Province.Methods:The next generation sequencing technology was used to detect the mutation of exon 18,19,20 and 21 of EGFR gene.We analyzed EGFR gene mutation rate in NSCLCs patients.233 patients was involved in our study.Results:82 cases with EGFR gene mutations was found,the mutation rate of exon18,19,20 and 21 was 1.3％,16.3％,0％ and 18％ respectively.The mutation rate of EGFR in male patients was lower (31.2％,39/125) than that of female cases (39.8％,43/108),the mutation rate of squamous cell carcinoma (22％,9/41) was lower than that of adenocarcinoma (39.1％,75/192).Conclusions:NSCLCs patients from southern Shaanxi Province had high mutation rate ofEGFR gene,and exon 19 and exon 21 mutations were in the majority.EGFR gene mutation rate was not related to gender and pathological types.

Objective To assess right ventricular(RV)systolic function in patients with pulmonary arterial hypertension(PAH)by 2-dimensional strain(2DS).Methods According to pulmonary artery systolic pressure,patients with PAH were divided into mild(17),moderate(15)and severe(10)PAH groups.Logitudinal peak systolic strain values were measured in RV global and free wall for basal,mid and apical segment in 42 patients with PAH and 31 healthy controls by 2DS from the apical 4-chamber view,and compared between groups and assessed the determinants of the RV functional parameters.Results Logitudinal peak systolic strain of RV global and free wall for all segments were significantly impaired in patients with PAH compared with controls and were most altered in patients with the severe PAH group compared with mild patients(P＜0.05 for all).Pulmonary vascular resistance and pulmonary artery systolic pressure were the determinants of RV function (γ1=-0.491～-0.641 and γ2=-0.403～-0.489,respectively,P＜0.05 for both).There were good correlations between tricuspid annular systolic peak velocity and strain of all segments in patients with PAH(γ=0.463～0.587,P＜0.001).Conclusions RV function in patients with PAH was decreased,RV longitudinal systolic function can be accurately and objectively studied by 2DS.

Objective To evaluate the left ventricular twist and radial displacement in patients with hypertrophic cardiomyopathy(HCM)by 2-dimensional(2D)ultrasound speckle-tracking imaging(STI).Methods 2D images of left ventricle at basal and apical short-axis views were acquired in 35 patients with HCM and 35 healthy subjects,and then were analysed off line to assess left ventricular(LV)rotation and radial displacement.Peak rotation(Prot)and the time to peak rotation in basal and apical short axis views were measured separately.Peak twist(Ptw),twist at aortic valve closure(AVCtw),twist at mitral valve opening(MVOtw),untwisting rate(Untw R),half time of untwisting(HTU),radial displacement were also calculated and compared and compared between HCM group and the control group.Based on the value of radial displacement,the LV twist-displacement loop was established and the features of the loop were analyzed.Results ①Compared with the control group,the value of Prot-MV,Prot-AP,Ptw,AVCtw,MVOtw and HTU increased significantly(all P＜0.05)and the Untw R decreased(P＜0.05)in the HCM group.②In HCM group,time to Prot in apical view was higher than that in basal.③ Twist-displacement loops could be constructed noninvasively.The liner slope changed significantly in HCM group compared with that of the control group.Conclusions The characteristics of LV rotation in patients with HCM were significantly different from the normals,and the STI measurement could be used noninvasively to evaluate the characteristics of LV twist and radial displacement.

Objective To assess the short-axis and long-axis systolic function of the left ventricle (LV) in patients with type 2 diabetes mellitus and without coronary artery disease using two-dimensional strain echocardiography.Methods Eighty-nine subjects with normal ejection fraction were included:37 with diabetes mellitus(DM group),22 with both diabetes and left ventricular hypertrophy(DH group), and 30 normal controls.Two-dimensional strain images were acquired from the LV short-axis view at the levels of mitral annulus, papillary muscle and apex, and the apical four-chamber view, two-chamber view and long-axis views of the LV respectively.The longitudinal strain was measured in the apical views.The radial strain and the rotation were measured in the LV short-axis views.The LV twist was defined as the apical rotation relative to the base.Results The average peak systolic longitudinal strain of different segments and the peak longitudinal global strain in DM group and DH group were significantly reduced when compared with those in control groups ( P＜0.001 ),and these parameters in DH group were significantly lower than those in DM group (P＜0.001 or P＜0.05).There was no significant difference in the average peak systolic radial strain of different segments and peak radial global strain among all groups ( P＞0.05).The LV rotations and the LV twist were significantly higher both in DM group and in DH group than in control group ( P＜0.001 or P＜0.01),and the basal LV rotation and the LV twist were larger in DH group than in DM group ( P＜0.01, P＜0.05).Conclusions Two-dimensional strain echocardiography may be used to identify the LV systolic function in patients with type 2 diabetes mellitus.

Objective To assess right ventricular(RV) global longitudinal function in patients with pulmonary arterial hypertension (PAH) by 2-dimensional ultrasound speckle tracking imaging (STI). Methods According to pulmonary artery systolic pressure, 42 patients with PAH were divided into mild (17) ,moderate(15) and severe(10) PAH groups. RV global longitudinal peak systolic strain (GLS), strain rate(GLSRs) ,early diastolic strain rate (GLSRe) and late diastolic strain rate (GLSRa) were measured in 42 patients with PAH and 31 healthy controls by STI from the apical 4-chamber view and compared between groups and assessed the determinants of the RV global longitudinal functional parameters. Results Right ventricular GLS,GLSRs,GLSRe, GLSRa were significantly impaired in patients with PAH compared with controls (P<0.05 for all). Right ventricular GLS were most altered in patients with the severe PAH group compared with mild PAH patients (P<0. 05). Right ventricular GLSRs, GLSRe, GLSRa were not significant between mild,moderate and severe PAH groups(P>0.05). Pulmonary vascular resistance and pulmonary artery systolic pressure were the determinants of RV global longitudinal systolic function(r= - 0.466～- 0. 549, r = - 0. 403～- 0. 425, respectively, P <0.05 for both). There were good correlations between tricuspid annular systolic peak velocity and RV GLS,GLSRs in patients with PAH (r = 0. 556～0. 585, P < 0.001). Conclusions RV global function decreases in patients with PAH, RV global longitudinal function can be accurately and objectively studied by STI.