For orthogonal frequency-division multiplexing (OFDM) communication systems, the frequency offset in mobile radio channels distorts the orthogonality between sub-carriers, which results in Intercarrier Interference(ICI) and seriously degrades the performance of systems. Based on ICI coefficients analysis, a novel precoder design scheme is proposed for mitigation of ICI. In this technique, precoder matrix is designed by the way of linear counteraction and inserted in the former transmitter signal. Computer simulation results show that this new scheme can effectively reduce ICI and significantly provide the carrier-interference power ratio improvement. Compared with existing ICI mitigation schemes with channel estimation, the proposed scheme has lower computational complexity, and compared with self-cancellation scheme, the bandwidth efficiency can be improved in this proposed scheme. The proposed scheme also has better convergence stability for time-varying frequency selective fading channel.

Objective　To evaluate the safety and efficiency of percutaneous coronary interventions(PCI) in octogenarian Chinese with coronary artery disease.　Methods　A total of 43 patients aged over 80 years old underwent 45 such procedures at Queen Mary Hospital from October 1994 to May 1998. There were 27 male and 16 female 〔 mean age (82.3±2.5), range (80-89)〕. 55.8% of these patients had multi-vessel lesions. A total of 48 lesions in 43 patients was treated 〔25 LAD(52.1%), 11 LCX(22.9%) , 11 RCA(22.9%), 1 LM (2.1%)〕. 　Results　Thirty-seven (86.1%) patients were successfully performed PCI. Sixteen of them deployed stenting. Among the 6 lesions which failed to cross, 5 of lesions were LAD, 3 of them were total occlusion. The success rate and complication during the procedure were not significant difference compared with the control in 237 patients ＜80 years of age. At 18 months follow up, 78.5% of these patients was free or much improved of chest pain. The restenosis rate was 36.0% confirmed by coronary angiogram performed in 25 patients. 　Conclusions　In octogenarians with coronary artery disease PCI was a safe and effective procedure with a high successful rate, low acceptable complication rate and a favorable immediate and long term outcomes.

In order to investigate the impact of channel estimation error on channel capacity of multiple input multiple output (MIMO) system, a novel method is proposed to explore the channel capacity in correlated Rayleigh fading environment. A system model is constructed based on the channel estimation error at receiver side. Using the properties of Wishart distribution, the lower bound of the channel capacity is derived when the MIMO channel is of full rank. Then a method is proposed to select the optimum set of transmit antennas based on the lower bound of the mean channel capacity. The novel method can be easily implemented with low computational complexity. The simulation results show that the channel capacity of MIMO system is sensitive to channel estimation error, and is maximized when the signal-to-noise ratio increases to a certain point. Proper selection of transmit antennas can increase the channel capacity of MIMO system by about 1 bit/s in a flat fading environment with deficient rank of channel matrix.

Objective To investigate the efficacy of cavo-meso-atrial shunt for the treatment of Budd-Chiari syndrome (BCS) with occlusion of both inferior vena cava (IVC) and hepatic veins (HVs) lesions. Method 14 cases with BCS due to combined occlusion of IVC and HVs were treated from 1996. 8 cases were male and 6 cases female.The age ranged from 20 to 36 years old. HVs occlusion with complete IVC occlusion was found in 12 cases and stenosis of IVC in 2 cases. Cavo-meso-atrial shunt was performed. Result There was no perioperative death. Thrombosis of graft occurred in two cases, one died of upper digestive tract bleeding and hepatic coma half year post-operation. The mortality rate at follow-up period was 7%, the total patency of graft was 86% and the patency of cavo-atrial graft was 93%. The decrease in portal vein pressure was between 5 to 26 cmH 2O with an average of 15.5 cmH 2O. No serious complications occurred. Conclusion The cavo-meso-atrial graft shunt is an alternative to treat patients with occlusion of both IVC and HVs due to IVC thrombosis. The long term patency remains to be evaluated.

Objective To evaluate the effect of PTCA in patients younger than 40 years of age. Methods Patients aged 40 years or less who underwent PTCA were recruited. Clinical and angiographic data were reviewed. Results A total of 82 patients underwent such procedures. Successful PTCA were performed in 80 patients (97.56%), 93 lesions were treated (97.89%), resulting in an improvement in diameter stenosis from 84.5%?11.8% to 4.1%?1.2%. One patient (1.22%) required bypass surgery without death and Q-wave myocardial infarction. During 42.1?6.8 months′ follow-up, 3 patients died (non-cardial cause in two cases), 3 sustained a myocardial infaraction, and 1 required bypass surgery. 87.8% of patients were free of angina. The target vessel revascularisation rate (TVR) was 12.19%. Angiographic follow up were performed in 70 patients (8.4?5.2 months). The total restenosis rate was 31.43%, 13.16% in stent group. Conclusion Coronary angioplasty has a high immediate success rate and good long-term result when performed in young patients who can be treated safely and effectively with coronary interventions.

Objective To improve the comprehensive nursing abilities in the practice process in the practice base, to adapt to the needs of the development of community nursing. Methods Convenient sampling was adopted, 83 nurses were divided into the experimental group (43 nurses) and the control group (40 nurses),who interned in the practice base in the years 2008 and 2009, the control group received con-ventional teachings, and the experimental group was given the teaching method and modes which were targeted at and focusing on the training of ability. The practice result was compared between the two groups.- Results Based on the teachers, the assessment and mixed capability were higher in the experimental group, by the employers' evaluation, all of the indicators were higher than the control group, and it is statistically significant. Conclusions It can improve various nursing abilities of the community nurses by the teaching method and modes which are targeted and focusing on the training of capability.

The evaluation indexes are selected from the aspects of hospital behavior and user behavior based on the relevant theories on influence and the transmission characteristics of Wechat,with the data so acquired processed with the principal component analysis.In the end,the expression of evaluation was applied to the evaluation and analysis of the influence of the hospital Wechat.

Objective To evaluate the clinical effect of hydrotalcite in treatment of bile reflux gastritis.Methods66 patients with bile reflux gastritis were chosen in our hospital from May 2013 to May 2014 as the research object, according to the order of admission they were divided into two groups, 33 cases of control group were treated with sucralfate treatment, observation group patients were treated with hydrotalcite comparative analysis, clinical curative effect in the observation group and the control group of patients were compared.ResultsAfter treatment for a period of time after the 33 patients in the control group,the total effective treatment for 28 cases, the total effective rate was 84.85%, the observation group of 33 cases of patients treated with total effective number of 32 cases, the total effective rate was 96.97%.The effective rate of the observation group was significantly higher than that of the control group(P<0.05).After the corresponding treatment, the incidence of complication in the control group was 15.15%, the observation group was 9.09%.There was no significant difference in the incidence of complications between the two groups.ConclusionThe use of hydrotalcite in treatment of bile reflux gastritis clinical curative effect significantly, can improve the treatment efficiency to a certain extent, high safety.

Objective To explore the change of serum leptin and significance in patients with chronic obstructive pulmonary disease(COPD). Methods The levels of leptin and tumor necrosis factor-? (TNF-?) of 34 COPD patients in stationary phase and 16 healthy people were measured by radioimmunoassay. The ideal body weight percentage(IBW%), triceps skin-fold thickness(TSF), arm muscle circumference(AMC), creatinine height index percentage(CHI%), total lymphocyte(TLC), albumin(ALB) were determined at the same time. The differences of parameters between patients and healthy people were compared. The correlation between parameters and leptin levels was analysed. Results Nutritional parameters were lower in COPD patients than in healthy controls(P

Objective To report the experience in diagnosing gastroenteric tuberculosis under en-doscopies, and arose enough attention to avoid missed or mis-diagnosis. Methods Biopsy is taken when lesions, such as gastroenteric mucosal protrusions, nodule, erythema and ulcer are found under endoscopies. Results In 7 cases studied, 2 of them are the gastric tuberculosis (1 ulceration, 1 proliferation) , the rest, colonic tuberculosis (4 proliferation and 1 mixed). Distribution of lesions: gastric antrum 2, each one in terminal ileum, ileocecal valve, terminal ileum plus ileocecum, terminal ileum plus pan colon, and ascending colon. Endoscopic diagnosis: colonic tuberculosis with infiltrative tuberculosis in both lungs 1; colonic malignant tumors 2, mucosal protrusions and ulcerative lesions with undefined nature 4. Caseous necrotic granu-lomas are found in all cases on pathological examination. Conclusion The various appearances of gastroenteral tuberculosis under endoscopies are hard in differentiating from those of colonic carcer, inflammatory bowel diseases ( Crohn' s disease etc. ) , gastric benign or malignant ulceration. The definite diagnosis of gastroenteral tuberculosis is greatly depended on pathological results.