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In order to study the effect of light with different wavelengths on the motion behavior of carp robots, phototaxis experiment, anatomical experiment, light control experiment and speed measurement experiment were carried out in this study. Blue, green, yellow and red light with different wavelength were used to conduct phototaxis experiments on carp to observe their movement behavior. By dissecting the skull bones of the carp to determine the appropriate location to carry the light control device, we independently developed a light control carrying device which was suitable for any illumination intensity environment. The experiment of the light-controlled carp robots was carried out. The motion behavior of the carp robot was checked by using computer binocular stereo vision technology. The motion trajectory of the carp robot was tracked and obtained by applying kernel correlation filter (KCF) algorithm. The motion velocity of the carp robot at different wavelengths was calculated according to their motion trajectory. The results showed that carps' sensitivity to different light changed from strong to weak in the order of blue, red, yellow and green, so that using light with different wavelengths to control the speed of the carp robot has certain laws to follow. A new method to avoid brain damage in carp robots control can be provided in this study.
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Animals , Algorithms , Carps , Motion , Phototaxis , RoboticsABSTRACT
Objective:To investigate the isolation characteristics and the antibiotic resistance of Streptococcus pneumoniae in hospitalized children from the Bao′an District of Shenzhen for many consecutive years, and to provide evidence for the assessment as well as clinical prevention and treatment of Streptococcus pneumoniae infection. Methods:The isolation rate and sample source of Streptococcus pneumoniae isolates as well as age composition of hospitalized children in Bao′an Maternal and Child Health Hospital of Shenzhen city from January 2012 to December 2018 were retrospectively analyzed.The susceptibility of the isolates to antibiotics was tested by disk diffusion method and E-test method. Results:(1) From 2012 to 2018, a total of 90 807 specimens were retrospectively summarized, 9 193 strains of Streptococcus pneumoniae were isolated, with an isolation rate of 10.1%, which was the first pathogen; 98.68% (9 072/9 193 cases) from respiratory tract samples and 97.20% from sputum samples.Among 107 strains isolated from aseptic body fluid specimens, 97 strains were blood specimens. Streptococcus pneumoniae was the most common bacteria with positive culture in aseptic body fluids.(2) The isolation rate of Streptococcus pneumoniae was 10.7% in children under 2 years old, 10.2% in children between 2 and 5 years old and 4.1% in children over 5 years old.About 97% of Streptococcus pneumoniae isolates came from children under 5 years old.(3) According to breakpoints of non-meningitis strains, the sensitivity rate of parenteral Penicillin was 93.18%, the mediation rate was 6.79%, the resistance rate was only 0.03%, the lowest drug concentration to inhibit the growth of 50% bacteria(MIC 50) value was 0.50 and the lowest drug concentration to inhibit the growth of 90% bacteria(MIC 90) value was 2.00; the sensitivity rate of Ceftria-xone was 76.55%, the mediation rate was 20.18%, the resistance rate was 3.26%, the MIC 50 value was 1.00 and the MIC 90 value was 2.00; when interpreted by the breakpoint of meningitis strains, the resistance rate of extra-gastrointestinal Penicillin reached 77.22%, and the mediation rate of Ceftriaxone increased to 30.48% and the drug resistance rate reached 18.45%.The drug resistance rates of Erythromycin, Clindamycin, Tetracycline and Compound neomycin were all over 85.00%.The resistance rates against Levofloxacin and Chloramphenicol were 0.16% and 7.85% respectively.No Vancomycin-resistant Streptococcus pneumoniae was found. Conclusions:Streptococcus pneumoniae is the first bacterial pathogen causing respiratory tract and invasive infection in hospitalized children under 5 years old in this area.Penicillin is still the preferred drug for non-meningitis pneumococcal infection, but the drug resistance rate is high in meningitis patients.
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Objective To establish a molecular method for the identification of different serotypes of group B streptococcus(GBS)based on TaqMan fluorescence probe technology,and to lay the foundation for the sub-sequent study of multiple fluorescent probe technology to detect different serotypes of GBS.Methods Primers and probes were designed according to the different serotypes of capsular polysaccharide(CPS).CPS se-quences were amplified by real-time fluorescence quantitative polymerase chain reaction.GBS classification methods of different serotypes were established.The results were compared with latex agglutination test and the method was evaluated from the aspects of sensitivity,specificity and detection of clinical isolates.Results The logarithmic concentration of DNA in the same serotype GBS was linearly correlated with the value of Ct. The detection limit of this method is 1 pg/μL,a probe could only detect the corresponding serotype GBS.The results of TaqMan fluorescence probe test of 10 strains were consistent with the results of latex agglutination test.Conclusion TaqMan fluorescence probe technique is a simple,rapid,highly sensitive and specific method for the detection of different GBS serotypes,and it is better than latex agglutination test for the classification of clinical isolates.
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AIM To study the chemical constituents from Vigna umbellata Ohwi et Ohashi.METHODS The ethyl acetate fraction of 80％ ethanol extract from V.umbellata was isolated and purified by silica,Sephadex LH-20 and ODS column,then the structures of obtained compounds were identified by spectral data and physicochemical properties.RESULTS Twelve compounds were isolated and elucidated as (+) catechin (1),(-) epicatechin (2),3-furanmethanol-β-D-glucopyranoside (3),myricetin-3-O-β-D-glucopyranoside (4),quercetin7-O-β-D-glucopyranoside (5),(+) catechin-3-O-β-D-glucopyranoside (6),(+) catechin-5-O-β-D-glucopyranoside (7),quercetin-3 '-O-α-L-rhamnoside (8),(±) dihydroquercetin (9),quercetin (10),ethyl gallate (11),propanediol (12).CONCLUSION All the compounds are isolated from V.umbellata for the first time,and compounds 4,8,9,11,12 are first obtained from genus Vigna.
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Objective To understand the status and related influencing factors of critical thinking of medical students, so as to provide recommendations for the training methods of critical thinking of medical students. Methods A total of 380 medical students in third and fourth grade of a medical university were investigated by using the California Critical Thinking Tendency Questionnaire and stratified random sam-pling method. 356 valid questionnaires were recovered. SPSS 22.0 software was used for statistical analysis, including t-test, analysis of variance and multiple linear regression analysis and other methods. Results The Cronbach'sαcoefficient of the scale was 0.728, and the cumulative variance contribution rate was 68.43%. The average score of positive critical thinking ability of medical students was 196.02, showing that they had positive thinking ability. Multiple linear regression analysis showed that the degree of extracurricular read-ing, whether there was a part-time job, and the students' self-study time per week had positive correlation with the critical thinking of medical students (P<0.05). Conclusion The critical thinking ability of medical students needs to be improved and the factors of critical thinking need to be further studied, and the research and practice of cultivating medical students' critical thinking ability must be deepened.
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BACKGROUND:Cerebral aneurysm is a kind of mortal hemangioma, and its treatments such as endovascular embolization and clipping both cause high postoperative recurrence rate and mortality. So the stent implantation for cerebral aneurysm is coming into being. OBJECTTVE:To evaluate the hemodynamic parameters after stent implantation into cerebral aneurysm and to provide a novel feasible strategy for clinical treatment. METHODS:A retrospective analysis was preformed based on the CT image data of 11 patients with cerebral aneurysm from the Affiliated Hospital of Xinjiang Medical University. Firstly, the flexible and solid model of cerebral aneurysm was established by the MIMICS and reverse engineering. Secondly, the matching stent model was implanted into the cerebral aneurysm, and then the blood flow structure of cerebral aneurysm was analyzed by the fluid dynamics theory and the Fluent with the method of two-way flow solid coupling. Final y, comparative analysis of the kinetic parameters of cerebral aneurysm before and after implantation, including wal pressure, blood velocity, path line of the blood flow, wal shear stress, wal deformation was conducted, and blood flow characteristics after stent implantation were analyzed under different entrance velocity. RESULTS AND CONCLUSION:After implantation, the wal surface pressure was reduced about 61.1%;the blood flow velocity around the stent and the inside of the cerebral aneurysm was decelerated obviously;under setting 2 000 lines of blood flow, the number of path line of blood flow into the cerebral aneurysm reduced about 75.0%, the maximum wal shear stress decreased about 79.3%, and the maximum wal deformation reduced to a lower level. The entrance velocity was respectively v1=0.1 m/s, v2=0.2 m/s, v3=0.3 m/s and the wal pressure was in a gradient ascent;the wal shear stress increased with the velocity, meanwhile,τzou (left neck of aneurysm)<τzhong (aneurysm )<τyou (right neck of aneurysm). The path lines of blood flow mainly concentrated in the top of the aneurysm, and the blood velocity markedly affected the surface deformation. These results indicate that main hemodynamic parameters are obviously improved after stent implantation into cerebral aneurysm, and the blood velocity should never be neglectful in the treatment process.
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BACKGROUND:Numerical stimulation technology is a good method to analyze blood flow changes after intracranial aneurysm stenting that oftenresult in restenosis. OBJECTIVE:To explore the hemodynamic effect of stent implantation on patient-specific intracranial aneurysm and the distribution of the wal shear stress on the stent surface. METHODS:Brain CT data from a patient with intracranial aneurysm were extracted and optimized to establish a patient-specific intracranial aneurysm materialization model. Meanwhile, a three-dimensional model of rectangular section spiral stent was designed to develop an aneurysm model with the stent by the method of boolean operation. Then, the possibility of restenosis was analyzed based on the distribution of wal shear stress on the surface of stent model. RESULTS AND CONCLUSION:The wal shear stress on the stent surface which was more than 40 Pa increasedalong with the increase of blood velocity and blood viscosity at the same moment. However, the wal shear stress on the stent surface which was less than 0.5 Pa decreased along with the increase of blood viscosity, and its distribution was the largest when the blood velocity was 0. This stent provides a new insight into the controling of the aneurysm growth and rupture, but the restenosis area is too large. In order to prevent restenosis, the stent need to be optimized or reselected to keep the desired shear stress values of 0.5 to 40 Pa, and meanwhile to minimize the pulsating change of wal shear stress during a cardiac cycle.