Synthesis and characterization of PEG-coated poly(ethyl cyanoacrylate) nanoparticles

摘要:Injectable nanoparticle carrier, poly (ethylene glycol)-coated poly (ethyl cyanoacrylate) has been prepared by a simple method. At First, synthesizing PEG macromonomer of poly(ethylene glycol) monomethyl ether with acryloyl chlo ride, then graft copolymer of poly(ethyl cyanoacrylate) and poly(ethylene glycol)was yield by free radical polymerization of ethyl cyanoacrylate with PEG macromonomer in toluene solvent. Characterization of the copolymer has been per formed by FTIR, 1H-NMR and GPC analysis. Nanoparticles were easily prepared from the obtained amphiphilic copolymer.

free radical polymerizationamphiphilic copolymergraft copolymer
被引:2
Study on Tat Mediated Magnetic Nanoparticles Having Composite Targeting Function

摘要:This paper describes a new formulation of magnetic nanoparticles coated by a novel polymer matrix-O-Carboxylmethylated Chitosan (O-CMC) as a drug/gene carrier. The O-CMC magnetic nanoparticles were derivatized with a peptide sequence from the HIV-tat protein and transferrin to improve the translocationai property and cellar uptake of the nanoparticles. To evaluate the O-MNPsTat-Tf as a drug carrier, Methotrexate (MTX) was incorporated as a model drug and MTX-Ioaded O-MNPs-Tat-Tf with an average diameter of 75 nm were prepared and characterized by TEM, AFM and VSM. The cytotoxicity of MTX-Ioaded OMNPs-Tat-Tf was investigated with C6 cells. The results showed that the MTXloaded O-MNPs-Tat-Tf retained significant antitumor toxicity.

magnetic nanoparticlesdrug carrier
被引:2
Neurofeedback Treatment Study for ADHD by Using the Brain-Computer Interface Neurofeedback System

摘要:Neurofeedback or electroencephalogram (EEG) biofeedback technology is widely used in clinical rehabilitation field. In this paper, we used a brain-computer interface (BCI) neurofeedback system for attention deficit hyperactivity disorder (ADHD) children treatment.After 20 training sessions, integrated visual and auditory-conhnuous performance test (IVA-CPT), DSM-IV and conner scale results suggested that the attention of subjects had been strengthened, which showed that the BCI neurofeedback system could provide an effective therapy for treating ADHD children.

被引:2下载:5
Correlation Analysis between TCM Syndromes and Physicochemical Parameters

摘要:Traditionally, differentiation of syndromes of Traditional Chinese Medicine (TCM) mainly depends on the information obtained from four diagnosis methods. Now many physicochemical parameters are available in clinic. There exists great correlation between TCM syndromes and physicochemical parameters.The objective of the paper is to analyze the correlation between TCM syndromes and physicochemical parameters quantitatively. Correlation analysis has been widely studied and many analysis methods have been developed. Mutual information based on entropy can measure arbitrary dependence between variables. It has been applied to many kinds of fields, especially to pattern recognition. But most works are restricted to discrete variables and little work has been done to study the relation between discrete and continuous variables. A novel algorithm is proposed to calculate the mutual information between discrete and continuous variables. It is used to analyze the correlation between TCM syndromes and physicochemical parameters.

mutual informationTraditional Chinese Medicinepattern recognitiondiscrete variablesanalysis methods
被引:2
Experimental Study of Detection of Brain Tissue with Electrical Impedance Tomography after Cerebral Ischemic

摘要:Intracerebral haemorrhage (ICH), which has rapid attack and high death rate, usually leads to bad outcomes. Poor prognosis of this disease is primarily due to the difficulty of early discovery. Early detection or diagnosis would significantly reduce the rate of disability and mortality, and improve the prognosis of the patients. The purpose of this paper is to testify electrical impedance change and detection of brain tissue after cerebral ischemic with electrical impedance tomography. In this study, electrical impedance tomography (EIT) was applied to detect the onset of modeled on rabbits in real time, ICH model group were injected collagenase in the Corpus Striatum while rabbits in control group were injected the same volume of saline with collagenase. The subsequent process was monitored continuously by system of electrical impedance tomography;the rabbits were sacrificed by intravenous injection of over dose of hydration chlorine aldehyde, and then taken into being scanned by computed tomography (CT) with a resolution of l mm within 10 min after death. After that, the brains of the rabbits were taken out, fixed and cut into slices to detect the changes of brain tissue. We found that one- dimensional impedance and two-dimensional (2D) images of electric resistance of brain of the rabbits pretreated with collagenase obviously changed after injection and the hemorrhage could be found in the slices of brain and there were changes in the model rabbits group not only the electric resistance but also the brain tissues. Although quantitative index can't be provided by detection of intracerebral hemorrhage in rabbits with electrical impedance tomography's at this stage, cerebral hemorrhage can cause brain electrical impedance characters of the change, the completed experiments suggest that electrical impedance tomography (EIT) may become an effective technique to detect ICH.

electrical impedanceelectric resistanceintracerebral hemorrhageintravenous injectioncomputed tomographyCorpus Striatumdeath ratereal time
被引:2
Study of a Novel Small Caliber Vascular Graft in a Canine Model with Optical and Scanning Electron Microscopy

摘要:A novel biological small-diameter vascular graft was evaluated in a canine model. 3 cm long segments with 4 mm I. D. were implanted end-to-end in the carotid position of 12 dogs for 6 months. Color Doppler sonography was performed at the first week post-operation, and angiography was then administered to 9 grafts at 4th week, 12th week and 24th week respectively to monitor the graft pantency and blood flow characteristics.Vascular samples containing the grafts were collected at 1st week, 8th week, 12th week and 24th week after implantation. Morphological changes of the grafts were observed by optical and scanning electron microscopic (SEM) studies and compared with that of the original prosthesis and the normal host vessel. All grafts were patent throughout the experiment except one graft. Histopathology and SEM demonstrated both a nearly complete inner capsule of varied thickness lining the graft luminal surface and connective tissue adventitia formation at one-week post-operation. The neointima became confluent at 8 weeks and then compact but had no signs of hyperplasia up to 12 weeks; meanwhile on the neointimal surface newly grown endothelial-like cells were migrating from the stoma to the middle portion. The grafts also illustrated endothelialization in many "islands" in the mid-segment luminal surface of the grafts. In addition, the closer distance the cells towards the stoma were, the more morphological similarity the cells with the normal endothelial were. Taken together, the biological vascular graft remained patent for 24 weeks as a carotid prosthesis,characterized by the early and complete neointima formation plus endothelialization starting before 12 weeks post grafting. Therefore, the graft seems suitable for reconstruction of vascular lesions in dogs. Further studies may be carried out to extend the graft application for the clinical use.

flow characteristicsclinical use
被引:2
A novel stepwise thresholding for fuzzy image segmentation

摘要:A novel stepwise thresholding method for fuzzy image segmentation is proposed. Unlike the published iterative or recursive thresholding mehtods, this method segments regions into sub-regions iteratively by increasing threshold value in a stepwise manner, based on a preset intensity homogeneity criteria. The method is particularly suited to segmentation of the laser scanning confocal microscopy (LSCM) images, computerised tomography (CT) images, magnetic resonance (MR) images, fingerprint images, etc. The method has been tested on some typical fuzzy image data sets. In this paper, the novel stepwise thresholding is first addressed. Next a new method of region labelling for region extraction is introduced.Then the design of intensity homogeneity segmentation criteria is presented. Some examples of the experiment results of fuzzy image segmentation by the method are given at the end.

intensity homogeneityimage segmentationfuzzy imageconfocal microscopyregion labellingthreshold valuelaser scanningmethod of
被引:2
The Relationship Between Gene Mutation and Pathological Type of Lung Cancer

摘要:Objective: To investigate the relationship between gene mutation and pathological type of lung cancer, inspect and verify the consistency between homologous genes mutation in various pathologic type. Methods: Combined with the COSMIC and UniProt database, we obtained the reported overall big-sample mutation data of lung cancer and the protein sequences of the top 20 mutated genes, respectively. Analyze the data and cluster the protein sequences and then deduce the homologous gene. Ultimately, analyze the mutations of different pathological types of homologous genes. Results: TP53 (32.32%) has the highest mutation rate in lung cancer, followed by EGFR (29.12%). The copy number variability (CNV) of genes: KRAS, LRP1B, CDKN2A, KMT2C, FAT1, PIK3CA, RB1, ERBB4, GRIN2A and KDR between each pathological type is statically significant (P<0.05). The gene differential expression rate between adenocarcinoma and squamous carcinoma of gene TP53, KRAS, LRP1B, CDKN2A, STK11, FAT4, KMT2D, NFE2L2, KEAP1, PIK3CA, RB1, ERBB4, SMARCA4 and KDR are statistically significant (P<0.05). The similarity of the protein sequence of EGFR and ERBB4 can reach 93%, and FAT4 and FAT1 are 81%. For small cell carcinoma, there's no difference in CNV between the two groups of homologous genes, and no difference between FAT4 and FAT1 in adenocarcinoma. Conclusion: The CNV and gene expression of lung cancer-associated genes are relevant to pathologic types. GFR and ERBB4 are homologous, FAT4 and FAT1 are also among the top 20 mutation genes. Additionally, there's no difference in CNV between the two groups of small cell carcinoma, which is the same between FAT4 and FAT1 in adenocarcinoma.

被引:2
The Ballistocardiogram Signal Monitoring System Based on the GSM Network

摘要: Ballistocardiogram signal monitoring system based on GSM network was put forward in this paper. The system included a BCG signal acquisition module, a data processing module, a display module and a GSM module. The STM32F103VB microprocessor was used as the controlling core of the signal acquisition module. BCG signal acquisition, amplification, filtering and A/D conversion were completed by the resistance strain sensor and high precision A/D conversion chip of TM7708; VB6.0 software was used to realize the BCG signal analysis and processing;the SD card and LCD completed data storage and waveform display; the BCG data remote transmission and alarm function were realized through the GSM module. The system cannot only real-time monitor the changes of heart rate of patients by non-contact means, and can process data automatically, timely detection of arrhythmia and automatic alarm. The system is particularly suitable for heart disease patients receiving long-term home care;therefore, it has a broad application prospect.

GSM Networksignal acquisitionapplication prospectremote transmissionmonitoring systemsignal analysisdata processinghigh precisionstrain sensorheart diseasedata storageGSM networkheart rate
被引:2下载:3
In vivo Detection and Imaging of Intraventricular Hemorrhage in Neonatal Piglets Using Electrical Impedance Tomography

摘要:Intraventricular hemorrhage (IVH) is one of the most severe medical emergencies in neurosurgery. Early detection or diagnosis would significantly reduce the rate of disability and mortality, and improve the prognosis of the patients. Although present medical imaging techniques have high sensitivity to identify bleeding, the use of an additional, non-invasive imaging technique capable of continuously monitoring IVH is required to prevent contingent bleeding or re-bleeding. In this study, electrical impedance tomography (EIT) was applied to detect the onset of IVH modeled on 6 piglets in real time, with the subsequent process being monitored continuously. The experimental IVH model was introduced by one-time injection of 2 ml fresh autologous arterial blood into the ventricles of piglets. Results showed that resistivity variations within the brain caused by the added blood could be detected and imaged in vivo using the EIT method, and the magnitude and the size of region of interest on EIT images may be linearly associated with the volume of the blood. In conclusion, EIT has unique potential for use in clinical practice to provide invaluable real-time neuroimaging data for IVH after the improvement of electrode design, anisotropic realistic modeling, and instrumentation.

被引:2下载:1