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Objective:To investigate the application effect of the combined teaching model of digital 3D printed model and Tencent conference in case-based learning (CBL) teaching of oral and maxillofacial surgery.Methods:A total of 80 undergraduates in the classes of 2015 and 2016 were selected from School of Stomatology, Qingdao University. The students in the class of 2015 received traditional teaching, and those in the class of 2016 received the combined CBL teaching model of 3D printed model and Tencent conference. A questionnaire survey was used to evaluate the teaching effect, and theoretical examination was used to assess comprehensive abilities of the two groups. SPSS 24.0 was used to perform the chi-square test and the t-test. Results:There was no significant difference in the degree of satisfaction with teaching between the combined CBL teaching model of 3D printed model and Tencent conference and the traditional teaching model ( P>0.05), and both models were generally recognized and accepted by students. The experimental group had a significantly higher score than the control group (94.05±4.16 vs. 86.10±3.37, P<0.05). Conclusion:The combined teaching model of digital 3D printed model and Tencent conference integrates the advantages of the Internet and digital information and thus provides a certain reference for the teaching methods for other majors in stomatology.
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BACKGROUND:Primates are considered to be the most appropriate animal model of lumbar intervertebraldisc degeneration, but the disc degenerated characteristics of monkeys were rarely reported. OBJECTIVE:To verify the degenerated regularity and characteristics of lumbar intervertebral disks in rhesus monkeys with magnetic resonance T2 mapping and T1ρimaging technology. METHODS:The sagittal lumbar intervertebral disc magnetic resonance T2 weighted imaging,T2 weighted mapping imaging and T1ρweighted imaging of 63 adult rhesus monkeys were acquired on 1.5T magnetic resonance equipment. The T2-map value and T1ρvalue of lumbar intervertebral disc regions of interest were calculated on the post-processing workstation. RESULTS AND CONCLUSION:(1) This study obtained 425 better magnetic resonance images of lumbar intervertebral disks in adult rhesus monkeys. T2-map value and T1ρvalue of nucleus pulposus were most consistent by different persons, and the Kappa coefficient was more than 0.93. (2) The T2-map value and T1ρvalue of nucleus pulposus were both negatively correlated significantly with Pfirrmann grades (r=-0.842, P<0.01;r=-0.896, P<0.01). The T1ρvalue and T2-map value of nucleus pulposus were significantly statistical y different between Pfirrmann grades I-IV (P<0.001, P<0.001). The T1ρvalue of nucleus pulposus was negatively correlated significantly with Pfirrmann grade II-III (r=-0.517, P<0.01) and Pfirrmann grade IV-V (r=-0.499, P<0.01). The T2-map value of nucleus pulposus was also negatively correlated significantly with Pfirrmann grade II-III (r=-0.617, P<0.01) and Pfirrmann grade IV-V (r=-0.652, P<0.01). (3) The T2-map value of L1-2 and L2-3 segments nucleus pulposus were significantly lower than that in L6-7 and L7-S1 segments (P<0.05). (4) There were significant differences in age among the T1ρvalue and T2-map value of nucleus pulposus (r=-0.702, P<0.001, r=-0.730, P<0.001). (5) It is concluded that magnetic resonance T2 mapping and T1ρimaging technology can objectively and sensitively assess the degenerated process of nucleus pulposus in rhesus monkeys. The degeneration in upper lumbar segments (L1-2 and L2-3) was earlier and more severe than that in lower lumbar segments (L6-7 and L7-S1) in rhesus monkeys. Age is one of the most important factors in lumbar intervertebral disc degeneration of adult rhesus monkeys.
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BACKGROUND:Tissue-engineered bone scaffold fabricated by 3D-bioprinting technique has good controlability in morphology and structure. However, construction of tissue-engineered bone/cel growth factor complex and time-dose effect of sustained-release factors are needed to be further researched. OBJECTIVE:To fabricate a sustained-release composite of polylactic-co-glycolic acid (PLGA)/nano-hydroxyapatite (n-HA) scaffold carrying bone morphogenetic protein-2 (BMP-2) using 3D-bioprinting technique, and test the biological properties of the PLGA/n-HA scaffold carrying BMP-2 and the sustained-release properties, thereby to discuss its feasibility as the tissue-engineered bone scaffold composite. METHODS:Temperature-sensitive chitosan hydrogel was prepared using chitosan andβ-glycerophosphate to construct a sustained-release composite, chitosan nanoparticles carrying BMP-2 . 3D-bioprinting technique was utilized to fabricate the PLGA/n-HA scaffold carrying BMP-2. Biological features of the scaffold composite were tested, and time-dose effect of BMP-2 sustained-release was observed. RESULTS AND CONCLUSION:The average pore size of the scaffold-cytokine composite was (431.31±18.40)μm, and the porosity was (73.64±1.82)%. The cumulative release rate of BMP-2 from the scaffold-cytokine composite that effectively controled the burst release during 48 hours and 30 days were suitable for the physiological needs. In conclusion, the porosity, pore size, release property, degradation rate, and mechanical strength of the scaffold-cytokine composite al meet the biological requirements of tissue-engineered bone construction.
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Objective Observation of 2 diabetic patients with insulin homocysteine(Hcy) levels before and after treatment ,to explore new diagnosis of diabetes patients with blood glucose control for the effect Hcy .Methods Extracted from 128 cases accord with standard of newly diagnosed type 2 diabetic patients ,randomly divided into control group and strengthen group ,64 cases each . Give control group oral sulfonylureas .To observe group use insulin intensive therapy .In the three months after treatment compared two groups before and after treatment of FBG ,HbA1c indicators related to change .Results All patients after treatment ,Hcy , FBG ,PBG ,HbA1c have decreased ,and Hcy in strengthen group decreased more obviously than in control group ,the difference was statistically significant level changes(P<0 .05) .Conclusion Insulin intensive therapy can be effective in the treatment of newly di‐agnosed type 2 diabetes .
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Medical intervention is to make use of puncture and catheterization technique for the diagnosis and treatment, relying on the guidance of medical imaging equipment. It is also a new medical branch which is independent of internal medicine and surgery. It is officially named the third largest medical technology. Interventional therapy contains blood vessel intervention and non-vessel intervention. The operation of the catheter and thread in the vessel is the key part of vessel intervention. By comparison it is found that the operation of catheter and thread in the blood vessel is similar to that of the string in the wellbore. Tubular mechanics in oil-gas wells is a mature theoretical mechanics system in the field of Petroleum Engineering. In this paper, the tension-torque model of the tubular mechanics in oil-gas wells is introduced, and the operation of catheter in a simulative vessel is mechanically analyzed with the software of mechanical analysis of drill string in directional wells.
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Humans , Biomechanical Phenomena , Blood Vessels , Pathology , Physiology , Catheterization, Peripheral , Methods , Magnetic Resonance Imaging, Interventional , Radiography, InterventionalABSTRACT
BACKGROUND: How to make growth factor plays a role persistently and efficiently is a key in constructing bone tissue engineered bone. Currently, varied microspheres or scaffolds were used as release carriers, however, the delayed release effects needs elevating.OBJECTIVE: To prepare chitosan microosPheres/nano-hydroxyapatite/poly (lactic-co-glycolic acid) (CMs/nHA/PLGA) scaffolds, and to measure its characteristics of delayed release of bovine serum albumin (BSA).METHODS: CMs were prepared by an emulsifying cross linking method with BSA as a model protein. Using ice particulates as porogen, composite CMs/nHA/PLGA scaffolds were prepared by freeze-drying. The characteristic and morphology of the composite were observed by scanning electron microscope, later particle size analyzer, mercury porosimeter and universal testing machine, and the release behavior of BSA was investigated in vitro.RESULTS AND CONCLUSION: The CMs were spherical shape with a regular surface, with diameters of 20-40 μm. The encapsulation efficiency of the CMs was 86.5%, and the loading capacity was 0.8%. With the increase of initial BSA dosage, the loading capacity increased to 2.6%, while the encapsulation efficiency decreased to 74.1%. The CMs can be uniformly distributed in PLGA scaffolds to form CMs/nHA/PLGA scaffolds, which had 100-400 μm pore diameter and over 80% porosity, with 1.1-2.3 pMPa compressive strength, and 26.5% cumulative degradation at 10 weeks. The cumulative release of BSA from nHA/PLGA scaffolds was above 85% at 36 hours, which from CMs was 33.6% at 10 days, and that from CMs/nHA/PLGA scaffolds was 81.5% at 40 days. The results demonstrated that CMs/nHA/PLGA scaffolds have an excellent releasing efficiency for protein drugs with suitable compressive strength and degradation, which would be used as delivery system and tissue engineering scaffolds.
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BACKGROUND:There are some disadvantages in harvesting and transferring cells in the traditional tissue engineering technique,and it is difficult to form dense tissues,which significantly limits the development of tissue engineering.OBJECTIVE:To explore the culture and fabrication of dog bone marrow mesenchymal stem cell(BMSC)sheet in vitro.METHODS:Bone marrow was extracted from dogs following anesthesia.BMSCs were isolated with the method of density gradient centrifugation in vitro.BMSCs at passage 4 at a density of 1×10~9/L were incubated in the temperature-responsive culture dishes with a diameter of 3.5 cm,and cultured in an incubator at 37 ℃,5% CO_2 and saturated humidity.The temperature of the incubator was changed from to 37 V to 20 ℃ to prepare BMSCs cell sheet for 20 minutes.Cell morphological changes and cell sheet formation were observed under an inverted microscope.RESULTS AND CONCLUSION:Dog BMSCs following 24 hours of primary culture presented ellipse or polygonal shape.Most cells adhered at hour 72,and cell colonies were visible at day 7.Cells showed long spindle and completely confluence at day 12,with unclear boundary.BMSCs in the temperature-responsive culture dishes presented short spindle shape,and gradually separated from the dish bottom,forming entire cell sheet containing extracellular matrix at 20 V.These verified that dog BMSCs can be effectively obtained with method of density gradient centrifugation.Complete cell sheet layer can be fabricated with temperature-responsive culture dishes.
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BACKGROUND:Conventional methods,including trypsin digestion and cells transfer using single call suspension,have many drawbacks,which limit the development of bone tissue engineering.OBJECTIVE:To culture bone marrow stromal stem calls,induce osteoblastic differentiation,and prepare cell sheets.METHODS:Canine bone marrow stromal calls were isolated by density gradient centrifugation technique,inoculated into DMEM medium,and induced to differentiate into osteoblasts.Complete call sheets were harvested by call sheet engineering based on the temperature change of temperature-responsive medium.RESULTS AND CONCLUSION:Immediately after inoculation,primary calls were scattered on the bottom of culture flask,presenting a transparent spherical body with a good refractive capacity.At 12 hours,calls exhibited a long shuttle shape,reached complete confluency,and grew in a whirlpool-like fashion.After osteoblastic induction,the majority of bone marrow stromal stem calls appeared tetragonal,polygonal,and squamose.At 21-28 days,round or oval-shaped calcified nodules formed.When the bone marrow stromal stem calls in the temperature-responsive culture dishes were cooled below the critical temperature 32℃,cells were gradually detached from the bottom of culture flask and formed complete bone marrow stromal stem call sheets.These findings indicate that density gradient cantrifugation technique can be used to successfully isolate and culture canine bone marrow stromal stem cells to differentiate into osteoblasts and call sheet engineering enables to harvest complete bone marrow stromal stem call sheets.
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BACKGROUND: Many operations for isolating, purifying and identifying bone marrow mesenchymal stem calls (BMSCs) are complicated and cost much. Also they have great effect on cell activity. Whether whole bone marrow adherent culture can avoid above-mentioned disadvantages remains unclear. At present, many studies huve been done to confirm an effective and low cost method for isolating, purifying and identifying such cells.OBJECTIVE: This study is to in vitro induce and differentiate rat BMSCs by whole bone marrow adherent culture,and to identify the cells.DESIGN: A controlled observational experiment.SETTING: Qingdao University Medical College.MATERIALS: This study was carried out in the Laboratory of Oral Cavity and Laboratory of Molecular Biology (provincial level) Qingdao University Medical College between November 2005 and March 2007. Twenty Wistar rats of either gender, aged 3 to 4 weeks, of SPF grade, weighing 120-150 g, were provided by the Qingdao Laboratory Center. The protocol was carried out in accordance with animal ethics guidelines for the use and care of animals. Fetal bovine serum (FBS, Hangzhou Sijiqing Bioengineering Material Research Institute), alkaline phosphatase (ALP) kit (Nanjing Jiancheng Bioengineering Research Institute), reverse transcription kit (American Promega Corporation) and primer (Shanghai Bioengineering Co.,Ltd.) were used in this study.METHODS: Adult rat BMSCs were isolated and cultured by whole bone marrow adherent culture. They were digested with 2.5 g/L trypse and inoculated at a density of 5 ×107 L-1 in 6-well culture plate. Then, the cells were divided into experimental group and control group. Inducing culture medium was added to experimental group, and the same amount of basic culture medium was added to control group. ① Cell differentiation and calcium tuberculation were observed under the inverted microscope. ② Biological characteristics of induced cells were detected by calcium tubercle Von Kossa and alizarin Bordeaux. ③ALP activity was detected by diazo salt staining. ④Human core binding factor alpha subunit-1 (Cbf α-1), osteocalcin (OCN) and osteoblast-specific Osterix (OSX) mRNA expressions were detected by reverse transcription-polymerase chain reaction (RT-PCR).MAIN OUTCOME MEASURES: ① Induction and differentiation results of cells. ② Biological characteristics of cells induced by rat BMSCs. ③ ALP activity. ④ Cbf α-1, OCN and OSX expressions.RESULTS: ①Inducing culture medium was added in the serial subcultivation. About 9 days later, cell clones were connected to each other. On about 21 to 28 days, some pykno-round mineralized tubercles appeared. Meanwhile,control cells were connected to each other, but they did not form the tubercle. ② In the experimental group, when MSCs were induced for 21 to 28 days, obvious round or oval calcified tubercles were seen by naked eyes. The results of Von Kossa staining exhibited black sediments, and those of alizarin Bordeaux staining exhibited salmon tubercles. Calcium tubercles were not found in the control group. ③The ALP activity after 2 weeks of induction was obviously increased in the experimental group, but was relatively weak in the control group. ④In the experimental group,Cbf α-1, OCN and OSX expressions were significantly increased after induction.CONCLUSION: After being in vitro induced and differentiated by whole bone marrow adherent culture, rat BMSCs exhibited morphological and biological characteristics similar to typical osteoblasts.
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Objective To discuss the efficiency and safety of transjugular intrahepatic portosystemic shunt(TIPSS) in treatment of cirrhotic patients with gastroesophageal variceal bleeding.Methods52 patients who had gastroesophageal variceal bleeding were treated with TIPSS,with 11 patients of them being active bleeding,23 patients being moderate to massive ascites.Results50 patients were treated successfully with the successful rate of 96.2%.The pressure of potal dropped from 3.87?0.50kPa to 2.45?0.40kPa(P