1.QoS awared power and admission controls based on non-cooperative game theory in wireless networks
Yang ZHANG ; Shihua ZHU ; Feng LI
Journal of Pharmaceutical Analysis 2008;20(3):149-154
In order to better accommodate heterogeneous quality of service (QoS) in wireless networks, an algorithm called QeS-aware power and admission controls (QAPAC) is proposed. The system is modeled as u non- cooperative game where the users adjust their transmit powers to maximize the utility, thus restraining the interferences. By using adaptive utility functions and tunable pricing parameters according to QoS levels, this algorithm can well meet different QoS reqniremcnts and improve system capacity compared with those that ignore the QoS differ- ences.
2.Myocardial perfusion abnormalities in patients with isolated left ventricular noncompaction
Yan LI ; Minfu YANG ; Xiaojin GAO ; Shihua ZHAO ; Yuejin YANG
Chinese Journal of Nuclear Medicine and Molecular Imaging 2014;34(5):354-357
Objective To investigate the myocardial perfusion abnormalities in patients with isolated left ventricular noncompaction (ILVNC) and analyze the correlation between MPI and MRI.Methods Nineteen patients (14 males,5 females,age range:15-76 years) with ILVNC diagnosed by cardiac MRI were recruited.All patients underwent 99Tcm-MIBI MPI.Both MPI and cardiac MRI were analyzed using a 17-segment model.The thickness ratio of the non-compacted to compacted layers of myocardium (NC/C) was calculated,and segments with NC/C>2.3 were considered as noncompaction.The incidences of delayed enhancement (DE) and myocardial perfusion abnormalities in non-compacted segments and compacted segments were calculated.x2 test was used for categorical data.The Pearson and Spearman correlation coefficient were used to assess the relationship between the numbers of myocardial segments with myocardial perfusion abnormalities/noncompaction/DE and lgLVEF.Results Of 19 patients,myocardial perfusion abnormality was found in 16 (84.2%) patients.The incidences of perfusion abnormality were 33.6% (36/107) in non-compacted segments and 31.9% (69/216) in compacted segments,respectively (x2=0.09,P>0.05).There were 31 segments with DE.The incidences of DE were 5.6% (6/107) in non-compacted segments and 11.6% (25/216) in compacted segments,respectively (x2 =2.94,P>0.05).The incidence of reduced perfusion was higher in segments with DE than those in segments without DE (54.8% (17/31) vs 30.1% (88/292) ; x2 =7.80,P<0.01).The lgLVEF and the numbers of myocardial segments with noncompaction/DE/myocardial perfusion abnormalities were not correlated(r=-0.35,0.15,-0.34,all P>0.05).Conclusion Most patients with ILVNC have myocardial perfusion abnormality,which can be observed both in non-compacted and compacted myocardium.Further research is required to elucidate the role of myocardial perfusion abnormality in ILVNC.
3.Clinical application of the blood transfusion with equal ratio component in severe multiple injuries with acute traumatic coagulopathy
Shihua HU ; Wenxin JIANG ; Yanxia YANG ; Min SU ; Minghan DENG
Chongqing Medicine 2015;(1):68-70
Objective To investigate the clinical effect of the blood transfusion with equal ratio component in severe multiple in‐juries with acute traumatic coagulopathy(ATC) .Methods Thirty‐eight patients who had severe multiple injuries with ATC were divided randomly into control group and treatment group .Control group was treated with the different ratio packed red blood cells (PRBC)and fresh frozen plasma(FFP) ,while treatment group received the equal ratio PRBC and FFP .Hemoglobin(HB) ,pro‐thrombin time(PT) ,international normalized ratio(INR) ,fibrinogen(FIB)were measured on the 1st ,2nd ,3rd day after admission . The total amount of PRBC during these 3 days ,the days of hospitalization in ICU ,the corrected rate of shock ,the 28‐day mortality were compared between groups .Results Compared with the control group ,the levels of PT ,INR and FIB of treatment group on the 2nd ,3rd day after admission were better(P<0 .05) .The total amount of PRBC[(18 .5 ± 6 .3)U]during these 3 days ,the days of hospitalization in ICU [(5 .9 ± 4 .3)d] in treatment group were less than those in the control group [(25 .9 ± 7 .8)U ,(10 .5 ± 7 .6)d] (P<0 .05) ,while the corrected rate of shock(85 .0% )in treatment group was higher than that of the control group(44 .4% ) .The 28‐day mortality(10 .0% )in treatment group was lower than that of the control group(27 .8% )(P<0 .05) .Conclusion The blood transfusion with equal ratio component in severe multiple injuries with ATC could not only improve blood clotting index ,reduce the total amount of PRBC and the time in ICU ,but also increase the corrected rate of shock and decrease the 28‐day mortality .
4.Comparison of 99Tcm-MIBI SPECT/18F-FDG PET imaging and cardiac MRI in assessment of myocardial injury cases with idiopathic dilated cardiomyopathy
Lei WANG ; Wei FANG ; Chaowu YAN ; Minfu YANG ; Shihua ZHAO
Chinese Journal of Nuclear Medicine and Molecular Imaging 2013;(2):141-145
Objective To evaluate the relationship of myocardial MR contrast delay-enhancement and nuclear perfusion-metabolism pattern in patients with idiopathic dilated cardiomyopathy (IDCM).Methods Forty-two consecutive patients (29 men and 13 women,age:(53 ±12) years) diagnosed clinically with IDCM were enrolled.All patients underwent 99Tcm-MIBI SPECT,18F-FDG PET imaging and MR contrast delay-enhancement imaging within 3-7 d.The myocardial perfusion-metabolism segment analysis was performed using a 17-segment model.Segmental 99Tcm-MIBI and 18F-FDG uptakes were scored visually using a 4-grade scoring system (0 =normal uptake,1 =mildly reduced uptake,2 =moderately reduced uptake,3 =severely reduced uptake).Patterns of perfusiorn/metabolism were classified as normal,mismatch,mild-to-moderate match and severe match.Myocardial MR contrast delay-enhancement was classified into 3 categories (non,mid-wall and transmural delay-enhancement).x2 test was used to analyze the differences of perfusion/metabolism patterns among non,mid-wall and transmural delay-enhancement groups and the myocardial MR contrast delay-enhancement incidence among four perfusion/metabolism groups.Resuits Among the 42 patients,myocardial delay-enhancement was present in 18 patients,of which 94.4% (17/18) showed abnormal myocardial perfusion/metabolism patterns and only 33.3 % (8/24) patients without abnormal myocardial delay-enhancement had abnormal myocardial perfusion/metabolism patterns (x2 =15.944,P < 0.001).Perfusion/metabolism patterns varied in three different categories of non,mid-wall and transmural delay-enhancement (x2 =14.276,P < 0.001).The normal peffusion/metabolism pattern proportions in the non,mid-wall and transmural delay-enhancement groups were 86.2% (526/610),71.0% (44/62) and 28.6% (12/42),respectively.The incidence of transmural delay-enhancement (44.4% (12/27)) was significantly higher in segments with severe match than that in the other 3 groups (normal:2.1% (12/582) ; mismatch:18.1% (15/83) ; mild-to-moderate match:13.6% (3/22) ; x2 =112.530,P < 0.001).Conclusions MR contrast delay-enhancement is much more sensitive in detecting moderate fibrosis,while nuclear perfusion-metabolism imaging can detect more impaired but viable myocardium.Combining the two imaging modalities is useful for providing comprehensive evaluations of myocardial injury in patients with IDCM.
5.Research on Effect Factors to Function of Human-machine System as Displaying with LCD.
Jie LI ; Weihao YANG ; Shihua ZHOU ; Qianxiang ZHOU ; Ting JIANG
Space Medicine & Medical Engineering 2006;0(02):-
Objective To provide the experimental data for standard establishment and ergonomics research on manned spaceflight displays basing on relation of six effect factors to function of human-machine system as displaying with LCD,and the best factor-level-composition is chosen.Methods An experimental system was developed.The orhoganal experiment means was adopted.Twenty subjects were asked to finish three tasks: to view parameters of the whole screen interface,to seek local parameters,to identify the fault events quickly.Three indices: reaction time,error times and times of unable to recognize were analyzed.Results The indices were much different for different factors at different levels.According to the indices of mean reaction time,extreme difference of view-angle was the lowest and view-distance the highest.Conclusion The order of the display effects of different factors on human-machine system is successively: viewdistance,illuminant level,character height,color of character/background and viewangle.
6.MRI assessment of acute myocardial infarction with transplantation of autologous mesenchymal stem cells in swine:an experimental study
Minjie LU ; Shihua ZHAO ; Haiyan QIAN ; Shiliang JIANG ; Yunqing WEI ; Chaowu YAN ; Yuejin YANG ; Yuqing LIU
Chinese Journal of Radiology 2008;42(2):201-205
ObjectiveTo investigate the effects of autologous bone marrow-derived mesenchymal stem cells (MSCs)transplantation on acute myocardial infarction in swine models using MRI. MethodsFourteen Chinese mini-pigs(27±3 kg)were divided into control group(n=7)and transplantation group(n=7).Acute myocardial infarction(AMI)model was made by occlusion of the left anterior descending coronary artery for 90 minutes,and then 10 ml autologous MSCs(3 × 106 cell/ml)were injected into LAD by over-wire-balloon catheter after one week. MRl was performed to assess the cardiac function and myocardial perfusion 1 week after AMI and 6 weeks after transplantation.The implanted cells in vitro were analyzed by immunofluorescence.ResuitsThe left ventricular ejection fraction(LVEF)in transplantation group was increased from(42.7 ±7.5)%to(50.1±10.1)%,which was significantly different from that in control group(P<0.01).In addition,the dyskinetic segments in infarcted region and the infareted area were decreased by 4 and 3.2 cm2 respectively(P<0.01),and the left ventricular weight index was increased by 4.1 g/m2 in transplantation group(P<0.05)compared with control group.The DAPI-labeled cells in infarcted and peri-infarcted region indicated the survived MSCs.Immunofluoreseence also confirmed that those cells expressed cardiomyocyte-specific troponin T,connexin 43 and vessel-specific smooth muscle actin.Capillary density in both infarcted and peri-infarcted region were higher in transplantation group than the control group(P<0.01).Conclusion MRI is a reliable imaging method for assessing the effects of stem cell transplantation in acute myocardial infartion of swine models.
7.Endovascular treatment of iliac femoral artery occlusive disease with TASC C, D lesions in elderly patients
Lei TIAN ; Xiguang LIU ; Zhonghua WANG ; Yufeng GU ; Xiaodong YANG ; Shihua WANG ; Chaojun ZHANG
Chinese Journal of Interventional Imaging and Therapy 2017;14(7):400-403
Objective To investigate the effect of endovascular treatment in iliac femoral artery occlusive disease of TransAtlantic Inter-Society Consensus (TASC) C,D lesions in elderly patients.Methods Totally 104 elderly TASC C,D patients with iliac femoral artery occlusion were treated,including TASC C (n =73),TASC D (n =31).Occlusive length range were 4.25-17.61 cm,with an average of (13.46±1.24)cm.The curative effect,complications and following up after surgery were analyzed.Results Ninty-four patients were treated successfully,and the technical success rate was 90.38% (94/104);12 patients underwent balloon dilation,92 patients underwent balloon dilation combined stent.There were 8 cases (8/104,7.69 %) with periprocedural complications,included arterial thrombosis (n =2),pseudoaneurysm (n=1),heart failure (n=4),and radiographic contrast nephropathy (n=1).Doppler ankle-brachial index increased from 0.32±0.12 to 0.81±0.11 (P<0.01) at 1 week after treatment.The patency rates were 88.46 % (69/78) and 81.13% (43/53) at 6 and 12 months followed-up respectively.Conclusion Minimally invasive endovascular treatment has high technical success rate,low complication rate,and satisfactory clinical curative effect for iliac femoral artery occlusive disease of TASC C,D lesions in elderly patients.
8.MRI late gadolinium enhancement of left ventricular apical aneurysms in hypertrophic cardiomyopathy
Chaowu YAN ; Sainan CHENG ; Lu LI ; Chen CUI ; Minjie LU ; Wei FANG ; Yang WANG ; Shihua ZHAO
Chinese Journal of Radiology 2017;51(5):345-349
Objectives To discuss the characteristics of late gadolinium enhancement (LGE) magnetic resonance (MR) imaging in patients with hypertrophic cardiomyopathy (HCM) and left ventricular apical aneurysm (LVAA) and its related prognostic value. Methods Thirty HCM patients with LVAA were collected from August 2004 to August 2013. All cases with coronary artery diseases were ruled out, and all patients underwent LGE derived by cardiac MR (CMR). Five cases of LVAA were pathological confirmed. Atrial and ventricular diameters, apical aneurysm diameters and left ventricular ejection fraction were measured, and apical aneurysm LGE was evaluated. All patients were then followed up. Comparisons in continuous parameters between patients with or without LGE were performed by independent t test. A Cox proportional hazard model was used to estimate the hazard rate for adverse cardiovascular events. Results LGE was identified in 21 LVAAs and non-LGE in 9 LVAAs. Between two groups, there was no significant difference in the size of LVAA [(16.4 ± 11.5) mm vs. (20.3 ± 9.8) mm, P=0.63]. In particular, the complete transition from non-LGE to LGE LVAA was recorded during follow-up in one patient. Pathological findings confirmed that LGE indicated fibrous tissue in LVAA, and LVAA without LGE indicated viable myocardium. The follow-up suggested that the patterns and the size of LVAA were associated with the adverse events in these patients (LGE of LVAA, HR=7.94, P=0.064; the size of LVAA, HR=1.08, P=0.009). Conclusions LGE-MR had important clinical significance in HCM patients with LVAA. LGE in LVAA corresponded with the fibrous tissue and was associated with the prognosis.
9.Relationship between myocardial glucose metabolism in right heart and cardiac function in patients with idiopathic dilated cardiomyopathy
Xinghong MA ; Lei WANG ; Liwei XIANG ; Yong YANG ; Shuliang HU ; Shihua ZHAO ; Wei FANG
Chinese Journal of Nuclear Medicine and Molecular Imaging 2015;35(2):81-84
Objective To explore the relationship between myocardial glucose metabolism in the right heart and cardiac function in patients with idiopathic dilated cardiomyopathy (IDCM).Methods From October 2010 to May 2013,64 consecutive patients (45 males,19 females; mean age:(53 ± 12) years) with IDCM were enrolled in this study.All patients underwent 18F-FDG myocardial PET imaging,late-gadolinium enhancement cardiac MRI (cMRI-LGE) and UCG.TrueD software was used to determine the SUVmax in right (SUV-R) and left (SUV-L) ventricular free wall,and the ratio of SUV-R to SUV-L (SUV-R/L) was calculated.The cMRI-LGE was used to evaluate LVEF,RVEF and LGE in left heart.Pulmonary artery systolic pressure (PASP) was measured by UCG.Two-sample t test and Pearson correlation analysis were used to analyze the data.Results Both SUV-R and SUV-R/L had negative correlation with LVEF (r=-0.48,-0.33; both P<0.01) and also with RVEF (r=-0.45,-0.44; both P<0.01).SUV-R/L positively correlated with PASP (r =0.58,P<0.01).SUV-R/L of patients with and without LGE were statistically different (0.45±0.18 vs 0.36±0.12; t=2.50,P<0.05).SUV-R and SUV-L of patients with LGE were 2.0±0.9 and 4.7±1.6,and those of patients without LGE were 1.7±0.9 and 5.0±2.8.Both differences of SUV-R and SUV-L between the two groups were not statistically significant (t=0.54 and 0.63,both P>0.05).Conclusions Myocardial glucose metabolism in right heart is closely correlated with left and right ventricular function.The assessment of 18F-FDG uptake in right heart by PET imaging is potentially useful for evaluation of the severity and prognosis in IDCM patients.
10.Combination of contrast-enhanced cardiac MR and nuclear myocardial imaging in evaluation of myocardial viability in ischemic cardiomyopathy
Yan LI ; Minjie LU ; Li WANG ; Zuoxiang HE ; Shihua ZHAO ; Minfu YANG
Chinese Journal of Radiology 2015;(6):425-429
Objective To explore the imaging characteristics and the complementarity of contrast?enhanced cardiac magnetic resonance CMR and nuclear myocardial perfusion/metabolic imaging in the evaluation of myocardial viability in patients with ischemic cardiomyopathy. Methods A total of 111 patients with diagnosed coronary artery disease and left ventricular dysfunction were retrospectively enrolled in this study. All patients underwent CMR and nuclear myocardial imaging within 1 month. Cine CMR was employed to evaluate cardiac function and wall motion. Contrast?enhanced CMR and myocardial perfusion/metabolic images were quantitatively assessed using a standard 17-segment and 5-score system. Dysfunctional segments were classified as viable or non?viable based on contrast?enhanced CMR and myocardial perfusion/metabolic imaging, respectively. No enhancement or sub?endocardial enhancement was defined as viable, while transmural enhancement was defined as non?viable. Severely matched perfusion/metabolism defects on nuclear imaging were assigned as non?viable while other patterns were considered as viable. Kappa index was calculated to evaluate the diagnostic concordance in assessing myocardial viability between contrast?enhanced CMR and myocardial perfusion/metabolic imaging. Results Among 1 887 segments in 111 patients, 80.3%(1 516/1 887) were dysfunctional. Of them, 63.3%(959/1 516) were viable and 36.7%(557/1 516) were non?viable on contrast?enhanced CMR, while 79.7%(1 208/1 516) were viable and 20.3%(308/1 516) were non?viable on nuclear myocardial imaging. The two modalities had a moderate concordance (Kappa=0.46,P<0.01). In segments with normal perfusion and metabolism, 73.9% (431/583) had various extent of enhancement but most of them(84.2%, 363/431) were subendocardial. On the other hand, 21.0%(117/557) segments with transmural enhancement had hibernating myocardium on nuclear imaging. Conclusions Contrast?enhanced CMR and nuclear myocardial imaging have a moderate concordance in the evaluation of myocardial viability in ischemic cardiomyopathy. Combination of the two modalities is expected to improve the diagnostic accuracy in assessing myocardial viability.