A new method of calculating fractal dimension of short-term heart rate variability signals is presented. The method is based on wavelet transform and filter banks. The implementation of the method is: First of all we pick-up the fractal component from HRV signals using wavelet transform. Next, we estimate the power spectrum distribution of fractal component using auto-regressive model, and we estimate parameter 7 using the least square method. Finally according to formula D = 2- (gamma-1)/2 estimate fractal dimension of HRV signal. To validate the stability and reliability of the proposed method, using fractional brown movement simulate 24 fractal signals that fractal value is 1.6 to validate, the result shows that the method has stability and reliability.
Algorithms ; Electrocardiography ; Fourier Analysis ; Fractals ; Heart Rate ; physiology ; Humans ; Least-Squares Analysis ; Nonlinear Dynamics ; Signal Processing, Computer-Assisted

Objective To evaluate the prevalence of aspirin resistance in old-aged patients with cerebral infarction and to analyze the mechanisms and clinical predictors of aspirin resistance. Methods 300 old-aged patients with cerebra] infarction were selected and the platelet aggregation ratio was determined by nephelometry with CHRONO-LOG PA-meter. And some information of these patients, such as age, sex, smoking, taking non-steroid anti-inflammatory drug (NSAD)or proton pump inhibitor (PPI), obesity, coronary artery disease (CAD), peripheral vascular disease, hyperpiesia, diabetes and hyperlipemia were recorded. Results 112 cases (37.33%) were aspirin sensitiveness, 108 cases(36.0%) were aspirin semi-resistance and 80 cases (26.67%) were aspirin resistance. These cases were divided into two groups. One was aspirin sensitive (AS) group, which included 112 patients of aspirin sensitiveness. The other was aspirin resistant (AR) group, which consisted of 188 patients of aspirin semi-resistance and aspirin resistance. The prevalence of CAD, hypercho]esteremia and RBC count in AR group was higher than that in AS group The percentage of patients who took NSAD, PPI and smoke in AR group was also higher than that in AS group. Conclusion Aspirin resistance existed in old-aged patients with cerebral infarction to great extent, and which was correlated with CAD, hypercholesteremia, smoking, RBC count, taking NSAD and PPI.

Objective To study the current status of morning blood pressure peak in elderly masked hypertension patients and study the correlation between morning blood pressure peak and cognitive function.Methods A total of 72 elderly masked hypertension patients were selected in this study,.Morning blood pressure peak was measured by ABPM examination.The patients were divided into three groups according to the morning blood pressure peak.Morning blood pressure peak ≤ 30 mmHg were divided into non-Morning blood pressure surge group ( NMS group),morning blood pressure peak ＞30 mmHg were divided into Morning blood pressure surge group ( MS group).The cognitive function scale was determined (MMSE and MoCA).T-test and linear regression analysis were performed.Results MMSE score(27.69±2.04) and MoCA scores(24.85 ± 1.52) in MS group were lower than NMS group (28.87 ± 1.34,26.54± 1.53) ( P ＜0.01 ).MMSE and MoCA scores were negatively correlated with the morning blood pressure peak ( r =- 0.308,- 0.447,P ＜ 0.01 ).Conclusions Elderly masked hypertension patients remained the phenomenon of the morning blood pressure peak,the morning blood pressure peak could lead to cognitive impairment.

Objective To investigate the ontogeny of the islet amyloid polypeptide(IAPP)and explore the relationship IAPP and other classical hormones in human fetal colon and rectum. Methods The localization of IAPP immunoreactive(IR) cells and 5 hydroxytryptamine(5 HT) IR cells in 31 human fetal colon and rectum from 9\|27 weeks of gestation was investigated with immunohistochemical SABC method. Results At 9 weeks of fetal age,a lot of 5 HT IR cells were found in the colon,but IAPP IR cells appeared at 18 weeks.In the rectum,both 5 HT and IAPP IR cells were present at 11 weeks,the number of 5 HT IR cells ascended gradually with fetus aged,reached a peak at 20 weeks and dropped gradually after 21 weeks,while in the whole fetus period,IAPP IR cells appeared fewer and scattered.The co localization of IAPP and 5 HT in some cells of colon and rectum was proved as compared with adjacent sections.Immunohistochemical double staining procedures on the same tissue section also showed that IAPP co existed with 5 HT in some cells.Conclusion\ During the human fetus,IAPP were synthesized and co existed with 5 HT in endocrine cells of the colon and rectum.The possible function on the co existence of IAPP and 5 HT in the colon and rectum of fetal was discussed. [

Autoantibodies ; blood ; immunology ; Child ; Diagnosis, Differential ; Humans ; Radiography ; Radionuclide Imaging ; Thyroid Diseases ; blood ; diagnosis ; diagnostic imaging ; Thyroid Function Tests ; methods ; Thyroid Gland ; diagnostic imaging ; immunology ; Thyroid Hormones ; blood

Objective To investigate photo-protective effect of NS398 on above cells damaged from UV irradiation.Methods HaCaT cell and HaCaT keratinocytes were incubated in the culture medium supplemented with different concentration of NS398 for 2h before diffierent dosages of UV irradiation.MTT assay was used to detect cell proliferation and cellular activity:Fluorospectrophotometer assay was used to measure the change of ROS level in the cells which were UV-mediated.Resuits After irradiation with UV,proliferation and cellular activity of HaCaT cells were decreased(P＜0.05);NS398 reduced the generation of ROS in cells induced by UV irradiation apparently and the cell apoptotic rate was dependent on the concentration of NS398. Conclusion NS398 might play an important role in the treatment of UV irradiation injury by decreasing the generation 0f ROS in cells after UV irradiation and increasing the survival ability of HaCaT cells.

Body Height ; Child ; Female ; Ghrelin ; pharmacology ; Growth Disorders ; physiopathology ; Growth Hormone-Releasing Hormone ; pharmacology ; Human Growth Hormone ; blood ; physiology ; urine ; Humans ; Insulin-Like Growth Factor Binding Protein 3 ; blood ; Insulin-Like Growth Factor I ; physiology ; Male

Age-related macular degeneration (AMD) and cataract are the most common causes of low vision worldwide.Nowadays, there is still a controversy about whether cataract surgery should be taken in patients combined with AMD and when should the surgery be taken.The aim of this review is to assess the influence of cataract surgery on the occurrence and development of AMD, to analyze the risk factors, to explore the occasion of cataract surgery in patients with AMD, and joint with anti-vascular endothelial growth factor (VEGF) treatment, also including the development and application of intraocular lens.It helps to avoid and postpone the development and progression of macular degeneration after cataract surgery and get good visual outcome.

Objective To find a method for denoising of ECG signals during spaceflight.Method According to noise character of ECG during spaceflight,a new denoising method that combines wavelet transform and shape filter was put forward.Result By practical application and simulation test,it was proved that this method could eliminate efficiently noise from ECG during spaceflight.Conclusion The method that combines wavelet transform and shape filter can be used for ECG denoising during spaceflight.

OBJECTIVETo observe the clinical efficacy and safety of sildenafil in the treatment of high altitude heart disease associated with severe pulmonary arterial hypertension (PAH) in children.

METHODSFifty children (aged 2 months to 2 years) with high altitude heart disease associated with severe PAH, who were continuously transferred to the Intensive Care Unit between January 2011 and October 2013, were randomly assigned to observation and control groups. The control group was given conventional treatment, while the observation group received oral sildenafil [1 mg/(kg . d)] three times daily for 7-10 days in addition to the conventional treatment. Before and after treatment, hemodynamics, blood gas, routine blood parameters, and blood biochemical parameters were recorded.

RESULTSAfter treatment, the observation group had a significantly higher decrease in mean pulmonary artery pressure and significantly higher increases in arterial partial pressure of oxygen, cardiac output, cardiac index, and oxygenation index compared with the control group (P<0.05). In the observation group, there were no significant changes in mean arterial pressure, routine blood parameters and blood biochemical parameters (P>0.05), and no obvious adverse reactions were found.

CONCLUSIONSFor children with high altitude heart disease associated with severe PAH, sildenafil can effectively reduce pulmonary artery pressure and improve cardiac function and does not cause adverse reactions. This therapy has good safety according to the preliminary evaluation.

Altitude ; Familial Primary Pulmonary Hypertension ; Female ; Heart Diseases ; drug therapy ; Humans ; Hypertension, Pulmonary ; complications ; physiopathology ; Infant ; Male ; Piperazines ; adverse effects ; therapeutic use ; Purines ; adverse effects ; therapeutic use ; Sildenafil Citrate ; Sulfones ; adverse effects ; therapeutic use ; Vasodilator Agents ; adverse effects ; therapeutic use