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        find Keyword "structure" 160 results
        • Part Ⅶ of database building: tag and structure of characteristics of colorectal cancer surgery (Ⅳ)

          ObjectiveTo explain details of colorectal cancer surgery in detail as well as their tags and structures of Database from Colorectal Cancer (DACCA) in the West China Hospital.MethodThe article was described in words.ResultsThe details of colorectal cancer surgery module included procedure of anastomosis, shape of anastomosis, type of staple, enhanced suture for anastomosis, stuffing, drainage, coverage of major omentum, anti-adhesion material, reconstruction of pelvic peritoneum, contaminate, drug implants, and nano of the DACCA in the West China Hospital were defined. The data labels corresponding to each item in the database and the structured ways needed for the big data application stage in detail were explained. And the error correction notes for all classification items were described.ConclusionsThrough the detailed description of the details of colorectal cancer surgery of DACCA in West China Hospital, it provides the standard and basis for the clinical application of DACCA in the future, and provides reference for other peers who wish to build a colorectal cancer database.

          Release date:2021-02-02 04:45 Export PDF Favorites Scan
        • The Protective Effect of Myocardial Hibernation Induced by D-Ala(2),D-Leu(5) Enkephalin on Myocardial IschemiaReperfusion Injury of Rabbits in Vitro

          Objective To investigate whether the agonist of delta opoid receptor D-Ala(2),D-Leu(5) enkephalin (DADLE) has the effect of decreasing myocardial injury during ischemia-reperfusion of adult rabbits’ myocardium,so that a new mehanism and way to myocardial protection could be found. Methods Langendorff model was used during the experiment. Thirty rabbits were divided into three groups randomly (each group 10 rabbits). Control group: St.Thomas Ⅱ cardioplegic solution was used; group 1: St.Thomas Ⅱ cardioplegic solution and DADLE (1mg/kg) were used; group 2: St.Thomas Ⅱ cardioplegic solution and naloxone(3mg/kg) were used to induce the hearts to arrest respectively. After arrest the hearts were reperfused respectively. Data of left ventricle development pressure(LVDP) was recorded before and after ischemia. Biochemical indicators of myocardium, lactate dehydrogenase(LDH) were detected before and after ischemia. Some myocardial tissues were used to explore the changes of the tissue of ultrastructure with electron microscope,when the experiment was over. Still some myocardial tissues were to be detected by flow cytometer to evaluate the apoptosis of the myocardium. Results The LDH and LVDP showed significant difference among three groups after ischemia(Plt;0.05); LVDP in group 1 was higher than those in group 2 and control group(69.8±5.8 mmHg vs. 23.4±3.9 mmHg; 69.8±5.8 mmHg vs. 37.9±4.7 mmHg; Plt;0.05), the LDH in group 1 was lower than those in group 2 and control group(1 272.6±59.1 U/L vs. 2 764.4±27.7 U/L, 1 272.6±59.1 U/L vs. 1 884.4±37.5 U/L; Plt;0.05). The apoptosis rate in group 1 was lower than those in group 2 and control group. As could be shown from the ultrastructure: mitochondria structure was nearly normal in group 1; mitochondria structure was injuried severely in group 2; there was a minor injury in control group. Conclusion Agonist of δ opoid receptor DADLE in cardioplegic solution could induce hibernation, which has myocardial protection effect during ischemia-reperfusion injury.

          Release date:2016-08-30 06:04 Export PDF Favorites Scan
        • Clinical Significance of Cardiac Structure and Function Evaluation by Cardiac Magnetic Resonance Imaging for Patients with Pectus Excavatum at Preoperation

          ObjectiveTo investigate the changes and clinical significance of cardiac structure and function evaluation by cardiac magnetic resonance imaging (CMR) for patients with pectus excavatum deformity at preoperation. MethodsWe retrospectively analyzed 54 patients (24 children and 30 adults) who underwent pectus excavatum surgery from June 2012 to June 2014. There were 48 males and 6 females at age of 7-33 (19.08±5.17) years. All the patients underwent CMR using 1.5 Tesla scanner for evaluation of compressing and displacement of the heart. The major and minor dimensions of right ventricle were measured. The right ventricle end-diastole volume (RVEDV), right ventricle end-systolic volume (RVESV), and right ventricle ejection fraction (RVEF) were also recorded and analyzed. ResultsThe heart compression and displacement occurred in 83.3% of the children group and 90.0% of the adults group. The extent of heart displacement in the adults was more serious than that in the children (76.86%±13.30% vs. 67.99%±8.15%, P<0.05). The structure of right ventricle were striking distorted because right atrum or right ventricule below valve ring was compressed locally, with the major dimension of right ventricle obviously increased, and the minor dimension of right ventricle obviously decreased. The indices of right ventricle major dimension and right ventricle minor dimension were 61.14±0.44 mm/m2 and 14.82±2.52 mm/m2 in the children, 49.54±15.40 mm/m2 and 18.90 ±3.14 mm/m2 in the adults. The RVEDV and RVESV were significantly higher in the adults than those in the children (139.09±29.08 ml vs. 121.50±31.27 ml; 73.61±16.05 ml vs. 64.92±19.28 ml; P<0.05). RVEF was similar between the children and the adults (45.29%±4.14% vs. 46.30±6.09%). The patients' symptoms disappeared after correction of pectus excavatum. ConclusionCMR is an useful method for evaluating right ventricular structure and functions in patients with cardiac compression and distortion by pectus excavatum before operation, which can bring strong indications for pectus excavatum repair surgery.

          Release date:2016-10-02 04:56 Export PDF Favorites Scan
        • Sequential Ultramicrostructural Observation on the Hypoplastic Lung of Fetal Rat Model of Congenital Diaphragmatic Hernia

          Objective To explore the mechanism of pulmonary hypoplasia in case of congenital diaphragmatic hernia (CDH), and study the ultramicrostructural features of lung tissue of CDH fetal rat models at different developmental stages. Methods Seven SpragueDawley (SD) pregnant rats were randomly divided into CDH group (n=4) and control group (n=3). For the rats in the CDH group, Nitrofen was used to fill in the stomach once at day 9.5 of pregnancy (125 mg of Nitrofen dissolved in 2 ml of olive oil each), and 3, 10, 17 fetal rats were collected at day 16, 18 and 21 of pregnancy respectively. For the rats in the control group, 2 ml of olive oil was used to fill in the stomach, and 10 fetal rats were collected at day 16, 18, and 21 of pregnancy respectively. The lung tissue sections of the fetal rats collected on day 16 were observed under transmission electron microscope (TEM). For the lung tissue of the fetal rats collected on day 18, hematoxylineosin (HE) staining and TEM observation were performed and the incident of CDH was detected. Besides the procedures carried out for the rats collected on day 18, the ratio of fetal lung to body weight was observed for the lung tissue of the fetal rats collected on day 21. Results (1) The ratio of fetal lung to body weight of fetal rats in the CDH group was significantly lower than that of fetal rats in the control group (0.0238 vs. 0.0430, Plt;0.01). The incidences of CDH in the 18thday and 21stday fetal rats in the CDH group were 90.00% and 82.35%respectively, while no CDH was observed in the corresponding fetal rats in the control group, suggesting pulmonary hypoplasia in the CDH group. (2) The ultramicrostructural observation showed that compared with the control group, pulmonary hypoplasia appeared in 16thday fetal lungs in the CDH group, i.e., broad breathing barrier substrate, little contents, predominant euchromatin and rich ribosomes in the alveolar epithelial cells, and no microvilli in the bronchial lumen. The observation on the 18thday and 21stday samples suggested that, with the progressing of pregnancy, the abovementioned features became more obvious. (3) Typical lamellated body was observed in fetal lung type Ⅱ alveolar epithelial cells from the 21stday fetuses in both the CDH group and the control group, suggesting that some late subcellular structures were normal. Conclusion Lung hypoplasia develops in the early period of fetal rats with CDH rather than in the late period, implying that the treatment of pulmonary hypoplasia of diaphragmatic hernia should be performed in the early stage of lung development.

          Release date:2016-08-30 05:56 Export PDF Favorites Scan
        • An identification method of chromatin topological associated domains based on spatial density clustering

          The rapid development of high-throughput chromatin conformation capture (Hi-C) technology provides rich genomic interaction data between chromosomal loci for chromatin structure analysis. However, existing methods for identifying topologically associated domains (TADs) based on Hi-C data suffer from low accuracy and sensitivity to parameters. In this context, a TAD identification method based on spatial density clustering was designed and implemented in this paper. The method preprocessed the raw Hi-C data to obtain normalized Hi-C contact matrix data. Then, it computed the distance matrix between loci, generated a reachability graph based on the core distance and reachability distance of loci, and extracted clustering clusters. Finally, it extracted TAD boundaries based on clustering results. This method could identify TAD structures with higher coherence, and TAD boundaries were enriched with more ChIP-seq factors. Experimental results demonstrate that our method has advantages such as higher accuracy and practical significance in TAD identification.

          Release date:2024-06-21 05:13 Export PDF Favorites Scan
        • Clinical Significance and Ultrastructure of Gastrin Secretory Granule in Colorectal Carcinoma Cells

          Objective To study ultrastructure and clinical significance of gastrin secretory granule in colorectal carcinoma cells. Methods The gastrin expression in colorectal carcinoma tissue and blood of 10 cases was examined by using radioimmunity analysis and immunohistochemistry. The ultrastructure of gastrin secretory granule of 10 cases, the positive of gastrin immunohistochemistry of colorectal carcinoma were examined by using immunoelectron microscopic technique. Results The gastrin concentration of the colorectal cancer group 〔(130.75 ±21.34) pg/ml〕 was significantly higher than that of control group 〔(95.63± 12.26) pg/ml〕,Plt;0.05. In 10 specimens of colorectal cancer, 5 cases were gastrin immunohistochemistry positive (+++), 4 moderate positive (++) and 1 weak positive (+). Cells in colorectal cancer were polyshaped, with unusual nucleoli different in size, concentrating on the edge, the cytoplasm mitochondrion was plentiful with vacuolates, and more secretion granules could be seen, 400-1500 nm in diameter with a clear border of membrane. There were two types of granular appearance: type A was largest in bulk size, low electrodensity was welldistributed, granular core appeared loose; type B was smaller in bulk size, high electrodensity was welldistributed, nucleus was usually compact.protein A gold (pAg) positive granules were located partially in secreting granules. pAg positive granules in highly differentiated cancer were mainly located in secreting granules of type A. pAg positive granules in low differentiated cancer were mainly located in secreting granules of type B. A part of cancer cell membrane, and inside and outside of microvillus membrane, adhering to pAg granules in line could be seen. Conclusion The colorectal carcinoma cells may synthesize and secrete gastrin themselves, which may be the mechanism of high gastrin levels in colorectal cancer. The use of gastrin antagonist and receptor antagonist may treat the patents with colorectal carcinoma.

          Release date:2016-08-28 04:47 Export PDF Favorites Scan
        • Research on exudate segmentation method for retinal fundus images based on deep learning

          Objective To automatically segment diabetic retinal exudation features from deep learning color fundus images. Methods An applied study. The method of this study is based on the U-shaped network model of the Indian Diabetic Retinopathy Image Dataset (IDRID) dataset, introduces deep residual convolution into the encoding and decoding stages, which can effectively extract seepage depth features, solve overfitting and feature interference problems, and improve the model's feature expression ability and lightweight performance. In addition, by introducing an improved context extraction module, the model can capture a wider range of feature information, enhance the perception ability of retinal lesions, and perform excellently in capturing small details and blurred edges. Finally, the introduction of convolutional triple attention mechanism allows the model to automatically learn feature weights, focus on important features, and extract useful information from multiple scales. Accuracy, recall, Dice coefficient, accuracy and sensitivity were used to evaluate the ability of the model to detect and segment the automatic retinal exudation features of diabetic patients in color fundus images. Results After applying this method, the accuracy, recall, dice coefficient, accuracy and sensitivity of the improved model on the IDRID dataset reached 81.56%, 99.54%, 69.32%, 65.36% and 78.33%, respectively. Compared with the original model, the accuracy and Dice index of the improved model are increased by 2.35% , 3.35% respectively. Conclusion The segmentation method based on U-shaped network can automatically detect and segment the retinal exudation features of fundus images of diabetic patients, which is of great significance for assisting doctors to diagnose diseases more accurately.

          Release date:2024-07-16 02:36 Export PDF Favorites Scan
        • Heterogeneity in Cardiac Structural Characteristics Among Patients with Preserved Left Ventricular Ejection Fraction Stratified by Sleep Apnea Subtypes

          ObjectiveTo explore the potential relationship between sleep apnea characterized by different Sleep Apnea subtype and cardiac structure and function.MethodsBased on the composition of sleep respiratory events, this study aimed to analyze whether patients with different subtype of sleep apnea exhibit specific cardiac structural characteristics. A retrospective analysis was conducted on 223 patients admitted to Guangdong Provincial Hospital of Traditional Chinese Medicine between 2018 and 2024 who completed polysomnography (PSG) and echocardiography. Participants were categorized into four groups based on respiratory event: ① with Cheyne-Stokes respiration Events (CSB), ② with central sleep apnea events and without CSB Event (ICA), ③ with obstructive sleep apnea events mainly (IOA), ④ non-sleep apnea controls (NSA), and observed the correlation of PSG parameters and echocardiographic.ResultsPatients with sleep apnea accompanied by CSR were older (χ2=36.014, P<0.001) and exhibited significantly larger left atrial diameter (χ2=41.823, P<0.001) and left ventricular end-systolic diameter (χ2=20.397, P<0.001) compared to other groups. Other sleep apnea subtypes demonstrated varying degrees of increased interventricular septal thickness (χ2=25.272, P<0.001) and left ventricular wall thickness (χ2=21.650, P<0.001) relative to non-apneic controls.ConclusionsAll sleep apnea subtypes are associated with hypertension-related cardiac structural alterations. Notably, patients with CSR-complicated sleep apnea exhibit more severe cardiac remodeling, leading to impaired systolic and diastolic functions.

          Release date:2025-06-25 01:52 Export PDF Favorites Scan
        • Study of the RNA Secondary Structure Prediction

          This paper proposes algorithm in predicting the RNA secondary structure that combines several sequence comparisons, searches the eigenvalue for subsequence division with dynamic programing, utilizing the minimum free energy method. Moreover, the paper assesses the results derived from this new algorithm based on base-pairs distance, climbing distance and morphology distance. The paper also compares the assessment result and the prediction results of different prediction tools, and analyzes the advantages of the new method and its improvement direction.

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        • Ultrastructural characteristics of human retinal progenitor cells

          Objective To observe the ultrastructural characteristics of human retinal progenitor cells cultured in vitro. Methods Six 5-month-old human fetuses(12 eyes)without eye diseases were selected. Retinal progenitor cells from the retina of one eye of each fetus were cultured in vitro,and observed by transmission electronic microscopy(TEM); while those from the other eye were directly observed by TEM. Results Abundant heterochromatin were found in the karyon of 5-month embryonic retinal neuroepithelial cells,and the figure of the karyons was irregular.A few scattered initial cells were seen in retinal neuroepithelial layer with large karyon,smooth surface,abundant euchromatin,and distinct nucleolus.The human retinal progenitor cells cultured in vitro had the same ultrastructural characteristics as the initial cells:with huge karyon which almost occupied the whole cell,little cytoplasm,distint nucleolus,abundant euchromatin,and little heterochromatin.The cells clung to each other in the neural globoid cell mass.The size of the outer cells was large,and karyokinesis could be found. Conclusion The cultured human retinal progenitor cells are provided with the same ultrastructure characteristics as the initial cells. (Chin J Ocul Fundus Dis, 2006, 22: 185-187)

          Release date:2016-09-02 05:51 Export PDF Favorites Scan
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          2. 射丝袜