The independent component analysis is a new method for signal processing, which has been paid attention to in the field of biomedical engineering. This paper introduces the design of biopotential analysis system based on ICA neural network and discusses its foundamental components.

Objective To retrospectively investigate the characteristics of patients with inflammatory bowel disease (IBD)in last 10 years in Kunming city. Methods Four hundred and thirty consecutive patients with IBD, who had hospitalized in 7 hospitals between January 1998 to March 2007, were investigated. Among them, 379 patinets had ulcerative colitis (UC) and 51 had Crohn's disease (CD). The patients who received coloscopy, histopathological and bariam enema examination accunted for 98.2%, 56.2% and 2.6% in UC group,respectively, and 72.5%,78.4% and 31.4% in CD group,respectively. The gender, age, occupation and the clinical manifestation of the patients, and the results of the colonoscopy and pathological examination were analyzed. Results Most of the UC patients were aged 30 to 39 years and 50 to 59 years with average age of (46.9±15.8) years, whereas CD patients were aged 20 to 29 years with average age of (41.6±17.2)years. The male and urban patients were predominat in both UC and CD groups. Mental workers were common in UC group. The symptoms of diarrhea (302,79.7%), abdominal pain (285,75.2%) and bloody stools (290,76.5%) were major events in UC patients, and those of abdominal pain (44,86.3%), diarrhea (28,54.9%) and weight loss (28,54.9%) were major events in CD patients. The coincidence ratio among colonoseopy, histopathology and bariam enema examinations was 88.4 % ( 329/372 ), 24.4 % ( 52/213 ) and 4/10 in UC patients, respectively, and 86.5%(32/37), 27.5%(11/40) and 75%(12/16) in CD patients, respectively. All of the UC patients were in active stage of disease,including 38.3 % in mild,42.2% in moderate and 19.5% in severe. In CD group, 7.8% was in relief stage and 92.2% in active stage,including 15.7% in mild,43.1% in morderate and 41.2% in severe.Conclusion The understanding of prevalence and clinical characteristics of IBD in last 10 years in Kunming city will be helpful in diagnosis and treatment of the disease.

A label-free electrochemical immunosensor using hollow structure nanomaterials based on its ordered porous and big surface area was designed. Au nanocage, with good conductivity, catalysis, and biocompatibility, was prepared and modified on the surface of glassy carbon electrode with graphene to immobilize antibody of microcystin directly. In the absence of microcystin, biosensor can obtain high current response signal of electrochemical probe ( [ Fe( CN) 6 ] 3-/4-. When microcystin was combined with its antibody specifically, the charge density and mass transfer resistance on the surface of electrode increased, resulting in a decrease of the corresponding peak current of [ Fe ( CN ) 6 ] 3-/4-. This change was in proportion to the concentration of microcystin indirectly. Experiment conditions such as cultivation time of antigen and concentration of antibody were optimized. The results showed wide linear range of 0. 05 μg/L-1. 0 mg/L and the detection limit of 0. 017 ng/mL. This sensor has good stability and simple production procedure. This sensor provides a new and simple means for the ultrasensitive determination of microcystins in real water samples.

OBJECTIVEThe aim of this study was to investigate the korrosionsneigung of three metal specimens for casing removable denture by means of electrochemical method.

METHODSThree kinds of test specimens were prepared, including cobalt-chromium alloy, nickel-chrome alloy with titanium and pure titanium. Then they were analyzed via linear polarization in artificial saliva simulating oral environment. From this electrochemical test the polarization curves of these kinds of specimens were recorded. Then the scanning electron microscope (SEM) and X-ray diffractometer (XRD) were applied to assess the morphology and phase changes before and after electrochemical corrosion.

RESULTSNo typical Tafel curve had been recorded for pure titanium, other than cobalt-chromium alloy and nickel-chrome alloy with titanium. Nickel-chrome alloy with titanium got more negative corrosion potential and higher corrosion current than cobalt-chromium alloy. Via SEM, the obvious changes were observed on the morphology and phase before and after corrosion on cobalt-chromium and nickel-chrome alloy with titanium specimens while pure titanium having no change. The XRD provided us little changes on these all three materials.

CONCLUSIONThe results confirm that the korrosionsneigung of the studied cobalt-chromium alloy in artificial saliva is lower than that nickel-chrome alloy with titanium. Pure titanium is the most stable one of the three materials and is extreme hard to be etched.

Chromium ; Chromium Alloys ; Corrosion ; Dental Alloys ; Electrochemistry ; Nickel ; Titanium

Objective To study the effect of psychological intervention in the rectal cancer after operation. Methods Thirty-seven patients each in control group and intervention group with rectal cancer after operation from February 2012 to February 2015 in our department were retrospectively analyzed. The complications, quality of life and psycho-logical status were compared between the two groups. Results The intervention group was significantly lower than that of the control group in urinary tract infection (χ2=4.44, P<0.05), intestinal obstruction (χ2=3.85, P<0.05), pulmonary infection(χ2=6.51, P<0.05). The intervention group were significantly higher than that in the control group after 4 weeks of the operation in physical function(t=5.75, P<0.01), role function(t=5.50, P<0.01), emotional function(t=6.08, P<0.01), cognitive function(t=6.60, P<0.01), social function(t=2.92, P<0.01). The intervention group was significantly lower than that of the control group in SAS(t=4.05, P<0.01) and SDS (t=3.11, P<0.01). Conclusion Psychological inter-vention can decrease the rate of postoperative complications and improve the psychological state in the rectal cancer after operation, it can also enhance the quality of life.