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find Keyword "Mean" 12 results
  • Image segmentation and classification of cytological cells based on multi-features clustering and chain splitting model

    The diagnosis of pancreatic cancer is very important. The main method of diagnosis is based on pathological analysis of microscopic image of Pap smear slide. The accurate segmentation and classification of images are two important phases of the analysis. In this paper, we proposed a new automatic segmentation and classification method for microscopic images of pancreas. For the segmentation phase, firstly multi-features Mean-shift clustering algorithm (MFMS) was applied to localize regions of nuclei. Then, chain splitting model (CSM) containing flexible mathematical morphology and curvature scale space corner detection method was applied to split overlapped cells for better accuracy and robustness. For classification phase, 4 shape-based features and 138 textural features based on color spaces of cell nuclei were extracted. In order to achieve optimal feature set and classify different cells, chain-like agent genetic algorithm (CAGA) combined with support vector machine (SVM) was proposed. The proposed method was tested on 15 cytology images containing 461 cell nuclei. Experimental results showed that the proposed method could automatically segment and classify different types of microscopic images of pancreatic cell and had effective segmentation and classification results. The mean accuracy of segmentation is 93.46%±7.24%. The classification performance of normal and malignant cells can achieve 96.55%±0.99% for accuracy, 96.10%±3.08% for sensitivity and 96.80%±1.48% for specificity.

    Release date:2017-08-21 04:00 Export PDF Favorites Scan
  • Expression of Integrin-αVβ3 in Vascular Endothelium Cultured in Vitro Under Different Level of Shear Stress

    Objective To observe the expression of integrin αVβ3 in vascular endothelium cultured in vitro at different time points under different level of shear stress. Methods(1)We established a vascular culture system in vitro which could provide steady flow with different level of shear stress, and tested the flow stability when loading different level of shear stress. (2) A total of 50 rabbits were randomly divided into low shear stress group (5 dyn/cm2, n=25)and normal shear stress group(20 dyn/cm2, n=25). Rabbits in each group were further randomly divided into five different time points as 2 h, 4 h, 8 h, 16 h and 24 h(n=5 at each time point). The descending aorta of rabbits were harvested and cultured in the vascular culture system in vitro under different level of shear stress. The expression sites and intensity of αVβ3-Integrin in vascular endothelium were examined at 5 different time points in both groups by immunohistochemical staining. Results The vascular culture system in vitro was stable in providing laminar flow with different level of shear stress required for the experiment. Vascular endothelium expressions of αVβ3-Integrin in the low shear stress group were in high level at all the 5 time points and reached its summit at 16 h, when the mean optical density(MOD)value was (1.995±0.194)×10-2. In the normal shear stress group, the MOD value decreased time-dependently at the 5 time points. The MOD values at 2 h (0.059±0.005)×10-2 and 4 h(0. 049±0.002)×10-2 were significantly higher than those at other time points (P< 0.05). The αVβ3-Integrin MOD values of the low shear stress group were significantly higher than those of the normal shear stress group at all the 5 respective time points (P=0.000). Conclusion Low shear stress can significantly promote the expression of αVβ3-Integrin while normal shear stress decreases the expression of αVβ3-Integrin in vascular endothelium cultured in vitro.

    Release date:2016-08-30 05:49 Export PDF Favorites Scan
  • Midterm Haemodynamic Assessment of the Home-made C-L Pugestrut Tilting Disc Mechanical Valve in Aortic Valve Replacement

    Objective To observe the midterm haemodynamic manifestation of the home made C-L pugestrut tilting disc mechanical valve in aortic valve replacement, and to evaluate its function. Methods Twenty patients underwent aortic valve replacement over 5 years were collected and divided into two groups, the C-L pugestrut group (n=10):aortic valve was replaced by home-made C-L pugestrut tilting disc mechanical valve(21mm); Medtronic-Hall group (n=10):aortic valve was replaced by Medtronic-Hall mechanical valve (21mm). The peak transprosthetic gradients (△P), mean transprosthetic gradients (△Pm)and effective orifice area(EOA) at rest were compared between two groups. Results At rest, △P of the C-L pugestrut group and Medtronic-Hall group were 11.63±3.23mmHg vs. 9. 78±3. 35mmHg; △Pm of the C-L pugestrut group and Medtronic-Hall group were 6. 25±2. 32 mmHg vs. 5.85±2.32mmHg: EOA of the C-L pugestrut group and Medtronic-Hall group were 1.07±0.17 cm2 vs. 1.25±0.27 cm2. There was no statistically significance in △P, △Pm and EOA between two groups(P〉0.05). Conclusions The midterm haemodynamic results of the home-made C-L pugestrut tilting disc mechanical valve show that it has comparable haemodynamic results to those of Medtronic-Hall mechanical valve ,and it has well-done function. The home-made C-L pugestrut valve is one of the reliable mechanical heart valves.

    Release date:2016-08-30 06:23 Export PDF Favorites Scan
  • Mean flow in internal mammary artery graft and its influencing factors in the Chinese

    Objective To analyze the mean flow in left internal m am mary artery ( L IMA) graft and the influencing factors in off- pump coronary artery bypass grafting ( OPCAB) in the Chinese. Methods One hundred and eighty patients with OPCAB were studied.Transit- tim e flowmeter( TTFM) was utilized to measure and record the L IMA’s blood flow wave,pulsatility index( PI) ,value of mean flow,systolic and diastolic peak flow,vascular resistance,insufficiency ratio and mean blood pressure and to analyze the relationship between mean flow of LIMA and other factors. Results Total mean flow calculated from that of all patients was2 8.19± 2 .89ml/ min( 6 - 178 ml/ m in) .Majority m ean value ( 6 4 .4 % ) was in the range of 10 - 30 ml/ min.Statistics showed that mean flow was significantly related to systolic and diastolic peak flow and vascular resistance rather than the other factors( r=0 .75 , 0 .94 ,- 0 .95 ) . Conclusions For the Chinese,over 10 ml/ min mean flow of L IMA graftis acceptable and ov...更多er 2 2 ml/ min is satisfactory.The diastolic peak flow and vascular resistance are two most important factors in influencing mean flow.

    Release date:2016-08-30 06:27 Export PDF Favorites Scan
  • Means Testing for Targeting Population in Health Programs: A Systematic Review

    Objectives To describe the mechanism of means testing used in health programs for targeting poor population and to describe how the authors have assessed effects of means testing approaches where applicable. Method We searched 24 electronic resources which included evidence-based, health, economic and social databases, 7 international institution websites, grey literature review resources and Google. Screening and data extraction were conducted by two reviewers separately, and the differences were discussed by the third person or a review group. We systematically analyzed the included studied by theme analysis method from different dimensions. We also described the evaluation outcomes by the authors. Result A total of 10244 records were searched, and 58 studies were included after screening by title, abstract and full texts. A total of 13 studies described verified means testing (VMT) conducted as a targeting method in the US; simple testing method (SMT) was conducted in 16 countries; 26 studies described how proxy means testing (PMT) was used in 14 countries; andmixed means testing (MA) was conducted in 14 countries. Means testing as a targeting method was widely used in four health programs which included health insurance, cash transfer, provision of free health service and fee structure. The target population was poor. Only few studies analyzed the outcomes of means testing; 3 studies analyzed under-coverage and 11studies analyzed leakage as their indicators. Scare cost information could be obtained from the included studies. Conclusion Means testing is widely used in various health programs for targeting the eligible population in distributing benefits, especially in developing countries. Targeting as a means for allocating health resources is particularly important in LMICs for their constraints in budgets available for health. Meanwhile, a universal coverage strategy has become a worldwide issue, and how current health resources can be used equitably and efficiently is a concern from the policy practice. Means testing, as one of the tools in targeting eligible population, would help in this process.

    Release date:2016-09-07 11:23 Export PDF Favorites Scan
  • Investigation of the Function of Modified Shock Index in the Disease Assessment of Emergency Cases

    ObjectiveTo research on the correlation between modified shock index (MSI), traditional vital sign assessment indexes and the proportion of patients entering resuscitation room through emergency triage, and to discuss its significance and advantages for emergency triage. MethodA total of 22 153 emergency patients between January 1 and May 31, 2009 were retrospectively analyzed. We counted the shock index (SI), mean arterial pressure (MAP), MSI, and evaluated the reference range of MSI, based on which, the patients were divided into groups, and the proportion of patients entering resuscitation room in each group was compared. Based on pulse, systolic blood pressure (SBP), SI, MAP and MSI, the patients were again grouped for comparing the proportion of patients entering resuscitation room, and the positive predictive value, negative predictive value, and odds ratio (OR) were also analyzed. ResultsReference value of MSI ranged from 0.34 to 1.70 times/(min·mm Hg) (1 mm Hg=0.133 kPa). Positive predictive values:MSI (16.239%) >MAP (6.115%) >pulse (5.746%) >SBP (5.321%) >SI (3.689%). The negative predictive values were all at high levels and similar with each other. OR:MSI (6.138) >MAP (2.498) >pulse (2.431) >SBP (2.117) >SI (1.361). ConclusionsPulse, SBP, SI, MAP, and MSI are correlated with the proportion of patients entering resuscitation room, and can be regarded as guide for emergency triage, among which MSI may be superior to all other indexes.

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  • How to Estimate the Mean and Standard Deviation based on the Median, Range and Sample Size when Conducting Meta-analysis

    To introduce a method of estimating the mean and standard deviation based on the median, range and sample size. Therefore, the quantitative data without providing the mean and standard deviation can also be used in a meta-analysis. Examples were given to illustrate how to apply the estimation method.

    Release date:2016-10-02 04:54 Export PDF Favorites Scan
  • Advanced methods of data extraction for continuous outcomes in meta-analysis

    Sample size, mean and standard deviation are necessary when conducting meta-analysis for continuous outcomes. Advanced methods of data extraction were needed if the mean and the standard deviation couldn’t be obtained from a literature directly. Eight methods were introduced and two examples were given to illustrate how to apply the methods.

    Release date:2017-01-18 07:50 Export PDF Favorites Scan
  • The value of platelet volume indices in early period as prognostic indicators of sepsis

    ObjectiveTo investigate the prognostic value of platelet volume indices [mean platelet volume (MPV) and platelet distribution width (PDW)] in early period for patients with sepsis .MethodsThis retrospective study was conducted in a general ICU at a University Hospital from January 2015 to January 2017. Patients with sepsis were divided into a survival group and a death group according to 28-day prognosis. The demographic and clinical data were recorded and analyzed, including platelet indices, Charlson comorbidity index, Glasgow Coma Scale (GCS) score and Acute Physiology and Chronic Health Evaluation Ⅱ (APACHEⅡ) score. Multivariable COX proportional hazard ratio model was used to evaluate the 28-day mortality risk, and receiver operating characteristic (ROC) curve were used to evaluate the value of platelet volume indices.ResultsA total of 209 patients were enrolled in this study. Mean arterial pressure, pH, platelet count, serum creatinine, bilirubin, troponin I, prothrombin time, GCS score and platelet volume indices showed significant differences between the survival group (n=137) and the death group (n=72) (all P<0.05). Multivariable COX regression analysis revealed that the PDW was independently associated with 28-day mortality in sepsis (HR=1.068, 95%CI 1.002-1.139, P=0.043). The area under the ROC curve of PDW was 0.762 (95%CI 0.694 - 0.831), with a sensitivity of 86% and a specificity of 63% at a cut-off value of 18.65%.ConclusionPDW can be used as a powerful prognostic indicator in patients with sepsis following 28-day.

    Release date:2019-07-19 02:21 Export PDF Favorites Scan
  • The relationship between mean daily step counts and pulmonary complications after thoracoscopic lobectomy in elderly patients: A propensity score matching study

    Objective To investigate the relationship between preoperative mean daily step counts and pulmonary complications after thoracoscopic lobectomy in elderly patients. Methods From 2018 to 2021, the elderly patients with pulmonary complications after thoracoscopic lobectomy were included. A 1∶1 propensity score matching was performed with patients without pulmonary complications. The clinical data were compared between the two groups. ResultsTotally, 100 elderly patients with pulmonary complications were enrolled, including 78 males and 22 females, aged 66.4±4.5 years. And 100 patients without pulmonary complications were matched, including 71 males and 29 females aged 66.2±5.0 years. There was no significant difference in the preoperative data between the two groups (P>0.05). Compared to the patients with pulmonary complications, the ICU stay was shorter (8.1±4.4 h vs. 12.9±7.5 h, P<0.001), the first out-of-bed activity time was earlier (8.8±4.5 h vs. 11.2±6.1 h, P=0.002), and the tube incubation time was shorter (19.3±9.2 h vs. 22.5±9.4 h, P=0.015) in the patients wihout pulmonary complications. There was no statistical difference in other perioperative data between the two groups (P>0.05). The mean daily step counts in the pulmonary complications group were significantly less than that in the non-pulmonary complications group (4 745.5±2 190.9 steps vs. 6 821.1±2 542.0 steps, P<0.001). The daily step counts showed an upward trend for three consecutive days in the two groups, but the difference was not significant. Conclusion The decline of preoperative mean daily step counts is related to pulmonary complications after thoracoscopic lobectomy in elderly patients. Recording daily step counts can promote preoperative active exercise training for hospitalized patients.

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