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find Author "CHEN Chun" 7 results
  • Smart drug delivery systems based on nanoscale ZnO

    In view of the excellent biocompatibility as well as the low cost, nanoscale ZnO shows great potential for drug delivery application. Moreover, The charming character enable nanoscale ZnO some excellent features (e.g. dissolution in acid, ultrasonic permeability, microwave absorbing, hydrophobic/hydrophilic transition). All of that make nanoscale ZnO reasonable choices for smart drug delivery. In the recent decade, more and more studies have focused on controlling the drug release behavior via smart drug delivery systems based on nanoscale ZnO responsive to some certain stimuli. Herein, we review the recent exciting progress on the pH-responsive, ultrasound-responsive, microwave-responsive and UV-responsive nanoscale ZnO-based drug delivery systems. A brief introduction of the drug controlled release behavior and its effect of the drug delivery systems is presented. The biocompatibility of nanoscale ZnO is also discussed. Moreover, its development prospect is looked forward.

    Release date:2018-04-16 09:57 Export PDF Favorites Scan
  • Subdivision method of diagnosis-related groups based on decision tree model: a case study of inpatients with uterine fibroids

    Objective To explore the subdivision method of diagnosis-related group (DRG) by case-mix payment, and provide reference for reasonable imbursement mechanism and standard for DRG grouping, as well as disease cost accounting and performance assessment for hospitals. Methods The first page data of medical records of 17010 inpatients with uterine fibroids in Obstetrics and Gynecology Hospital of Fudan University from 2019 to 2021 were included. Based on the disease and treatment, combined with the length of hospital stay, other diagnosis and other factors, nonparametric test and generalized linear model were used to explore the factors affecting hospitalization expenses. Decision tree model was performed to yield case-mix related groups and predict the cost. Results The inpatients with uterine fibroids were classified into 13 groups in decision tree model based on the main surgical methods, other surgical types, and length of hospital stay. The reduction in variance was 0.34, and the coefficient of variation was 0.19-0.88. Conclusions The case-mix payment approach based on the decision tree model as the grouping method is more consistent with the actual clinical diagnosis and treatment of uterine fibroids, and can be used as method reference for the subdivision of DRG. Under the background of DRG, subdivision of DRG can provide decision-making basis for refined hospital management, including in-hospital cost accounting and performance allocation.

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  • FINITE ELEMENT STUDY ON ANTERIOR TRANSPEDICULAR SCREW-ARTIFICIAL VERTEBRAL BODY FIXATION IN LOWER CERVICAL SPINE

    Objective To compare the biomechanical properties of the anterior transpedicular screw-artificial vertebral body (AVB) and conventional anterior screw plate system (AP) in lower cervical spine by finite element study. Methods CT images (C1-T1) were obtained from a 38-year-old female volunteer. The models of intact C3-7 (intact group), AP fixation (AP group), and AVB fixation (AVB group) were established and analyzed by Mimics 14.0, Geomagic Studio 2013, and ANSYS 14.0 softwares. The axial force of 74 N and moment couple of 1 N·m were loaded on the upper surface and upper facet joint surfaces of C3. Under conditions of flexion, extension, lateral bending, and rotation, the Von Mises stress distribution regularity and maximum equivalent stree of AP and AVB groups were recorded, and the range of motion (ROM) was also analyzed of 3 groups. Results The intact model of lower cervical spine (C3-7) was established, consisting of 286 382 elements and 414 522 nodes, and it was successfully validated with the previously reported cadaveric experimental data of Panjabi and Kallemeyn. The stress concentrated on the connection between plate and screw in AP group, while it distributed evenly in AVB group. Between AP and AVB groups, there was significant difference in maximum equivalent stress values under conditions of 74 N axial force, flexion, extension, and rotation. AVB group had smaller ROM of fixed segments and larger ROM of adjacent segments than AP group. Compared with intact group, whole ROM of the lower cervical spine decreased about 3°, but ROM of C3, 4 and C6, 7 segments increased nearly 5° in both AP and AVB groups. Conclusion As a new reconstruction method of lower cervical spine, AVB fixation provides better stability and lower risk of failure than AP fixation.

    Release date:2016-08-31 10:53 Export PDF Favorites Scan
  • BIOMECHANICAL STUDY ON EFFECT OF POLYMETHYLMETHACRYLATE AUGMENTATION ON CERVICAL STABILITY AFTER ANTERIOR CERVICAL INTERBODY FUSION

    Objective To evaluate the effect of polymethylmethacrylate (PMMA) augmentation on cervical stabil ity after anterior cervical interbody fusion (ACIF) before and after fatigue. Methods Twelve porcine cervical spines (C3-7) were subjected to testing angular displacement parameters, including the range of motion (ROM), neutral zone (NZ), and elastic zone (EZ), in nondestructive flexion and extension, right/left lateral bending, and left/right rotation on Motion Analysis motion capture system and MTS-858 servo-hydraul ic testing machine. Intact cervical spines served as control group (group A); oneleveldiscectomy and fusion was performed with anterior plate fixation based on group A as group B; flexion and extension,left/right lateral bending (5 000 cycles) fatigue testing based on group B as group C; the augmentation screw channel was used based on group C as group D; and flexion and extension, left/right lateral bending fatigue testing were performed based on group D as group E. Results The ROM, NZ, and EZ in group A were significantly different from those in other groups (P lt; 0.05) at flexion/extension, left/right bending, and left/right rotation. The ROM, NZ, and EZ in group B were significantly smaller than those in group C (P lt; 0.05) in flexion/extension, left/right bending, and left/right rotation, but there was no significant difference when compared with group D (P gt; 0.05). The ROM and NZ in flexion/extension and the EZ in flexion in group B were significant smaller than those in group E (P lt; 0.05), but there was no significant difference in the other indexes (P gt; 0.05). The ROM, NZ, and EZ in group C in flexion and extension, left/right lateral bending, and left/right rotation were significantly higher than those in groups D and E (P lt; 0.05). The ROM and NZ in flexion and extension and left/right lateral bending, and the ROM in left/right rotation, and the EZ in flexion and extension, right bending, and left/right rotation in group D were significantly smaller than those in group E (P lt; 0.05), but there was no significant difference in the other indexes (P gt; 0.05). Conclusion PMMA augmentation can significantly increase the instant cervical stabil ity and provide a biomechanics basis in cervical anterior plate fixation.

    Release date:2016-09-01 09:03 Export PDF Favorites Scan
  • Regulations of VEP Changes in 30 Patients with Multiple Sclerosis

    Objective To study the regulations of visual evoked potential(VEP) changes in 30 patients with multiple sclerosis (MS). Methods VEP were performed in 30 MS patients,and the results were compared with normal subjects. Results The abnormality rate of VEP were 76.7%. 82.6% of patients with abnormal VEP showed clinical visual symptoms; 17.4% among those patients have no clinical visual symptoms. Conclusion  The rate of VEP abnormal in MS patients is more high. It may help more in the diagnosis of MS.

    Release date:2016-09-07 02:11 Export PDF Favorites Scan
  • Synthesis of transdermal aloesin loaded zinc oxide nanoparticles and its inhibitory effect on the activity of tyrosinase

    Zinc oxide quantum dots (ZnO QDs) were synthesized by gel-sol method and employed as the transdermal aloesin (Alo) carriers. ZnO QDs were surface-functionalized with amino using aminopropyltriethoxysilane (APTES). Alo was covalently bonded on the surface of ZnO QDs via N,N'-carbonyldiimidazole to obtain Alo NPs, which were characterized by transmission electron microscope (TEM), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR) and thermal gravimetric analyzer (TGA). TEM images showed that ZnO QDs were analogously sphere and monodisperse with a reasonably narrow size distribution, of which was around 4 nm. The size of Alo NPs increased to around 8 nm due to the surface modification. The intense bands at around 3 400 cm–1 and 1 200 cm–1 in the FTIR spectrum of Alo NPs from the vibration of -OH indicated the linkage of Alo on the surface of ZnO QDs. The results of TGA analysis showed that the mass ratio of ZnO QDs and Alo were 39.27% and 35.14%, respectively. The penetration of Alo NPs was much higher than raw Alo according to the passive penetration experiments with Franz-type diffusion cells instrument using full-thickness cavy skin, which manifested the improvement of the penetration for Alo delivered by ZnO QDs. The pH-controlled drug release behavior in vitro was investigated. At pH 7.4, only a small amount of Alo (1.45% ± 0.21%) had been released after 2 h. In contrast, as incubation at pH 5.0 of which pH was similar to endosomal environment, Alo was released very fast (87.63% ± 0.46% in 2 h) from Alo NPs, confirming that Alo NPs could response to the pH and realize the intracellular drug release. The inhibitory effect of Alo NPs on tyrosinase was in a dose dependent manner. When the concentration of Alo NPs was 12.5 μg/mL, the inhibition rate was up to 40.32% ± 1.57%. All the results show that the Alo NPs hold a great potential in transdermal tyrosinase inhibition.

    Release date:2019-04-15 05:31 Export PDF Favorites Scan
  • Chinese thoracic surgery experts consensus on postoperative follow-up plans for esophageal squamous cell carcinoma

    Resection is one of the most important treatments for esophageal squamous cell carcinoma, and routine postoperative follow-up is an effective method for early detection and treatment of recurrent metastases, which can improve patients' quality of life and prognosis. This consensus aims to provide a reference for colleagues responsible for postoperative follow-up of esophageal squamous cell carcinoma patients in China, and further improve the standardization of the diagnosis and treatment of esophageal squamous cell carcinoma.

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