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OBJECTIVE@#To investigate the anti-coronavirus potential and the corresponding mechanisms of the two ingredients of Reduning Injection: quercetin and luteolin.@*METHODS@#A pseudovirus system was designed to test the efficacy of quercetin and luteolin to inhibit SARS-CoV-2 infection and the corresponding cellular toxicity. Luteolin was tested for its activities against the pseudoviruses of SARS-CoV-2 and its variants. Virtual screening was performed to predict the binding sites by Autodock Vina 1.1.230 and PyMol. To validate docking results, surface plasmon resonance (SPR) was used to measure the binding affinity of the compounds with various proteins of the coronaviruses. Quercetin and luteolin were further tested for their inhibitory effects on other coronaviruses by indirect immunofluorescence assay on rhabdomyosarcoma cells infected with HCoV-OC43.@*RESULTS@#The inhibition of SARS-CoV-2 pseudovirus by luteolin and quercetin were strongly dose-dependent, with concentration for 50% of maximal effect (EC50) of 8.817 and 52.98 µmol/L, respectively. Their cytotoxicity to BHK21-hACE2 were 177.6 and 405.1 µmol/L, respectively. In addition, luetolin significantly blocked the entry of 4 pseudoviruses of SARS-CoV-2 variants, with EC50 lower than 7 µmol/L. Virtual screening and SPR confirmed that luteolin binds to the S-proteins and quercetin binds to the active center of the 3CLpro, PLpro, and helicase proteins. Quercetin and luteolin showed over 99% inhibition against HCoV-OC43.@*CONCLUSIONS@#The mechanisms were revealed of quercetin and luteolin inhibiting the infection of SARS-CoV-2 and its variants. Reduning Injection is a promising drug for COVID-19.
Subject(s)
Humans , SARS-CoV-2 , COVID-19 , Luteolin , QuercetinABSTRACT
Pathological diagnosis of lung cancer keep updating and developing, in order to meet the clinical needs in the era of precision medicine. It mainly involves the advances of histological subtype classification, molecular testing for targeted therapy, biomarkers detection for immunotherapy and the pathological evaluation for neoadjuvant therapy. Nowadays, pathological diagnosis of lung cancer present a multidisciplinary model including clinical medicine, radiology and pathology. It is gradually moving towards standardization with expection to provide better guidance for clinical treatment and prognosis.
Subject(s)
Humans , Lung Neoplasms/drug therapy , Prognosis , ImmunotherapyABSTRACT
Probe electrospray ionization (PESI) is one of the typical types of ambient ionization technology, but its application in quantitative analysis is limited due to its poor sampling stability. Previously, we developed a new micro-pen electrospray ionization tandem mass spectrometry (μPen-ESI-MS/MS) method based on PESI. In this study, a μPen-ESI-MS/MS method to measure testosterone and dextromethorphan in liver microsome samples was developed and validated to further applicate in evaluating drug metabolism stability and CYP450 enzyme activity. A μPen-ESI-MS/MS method for detecting the CYP3A4 substrate testosterone and CYP2D6 substrate dextromethorphan in the liver microsome incubation system were developed, and the linearity, precision and accuracy of the method was validated. The validated method was further used to detect the metabolic stability of testosterone in the liver microsome incubation system. The results showed that the μPen-ESI-MS/MS had high efficiency with 0.3 min spraying time of each sample. The standard curve of the testosterone and dextromethorphan has good linearity (R2 > 0.99), the intra- and inter-batch accuracy of testosterone and dextromethorphan was 95.9%-109.3% and 90.5%-107.3%, respectively; the intra- and inter-batch precision was acceptable with RSD values of 2.4%-13.5% and 3.4%-12.1%. The half-lives of testosterone and dextromethorphan in the liver microsome incubation system were 12 min and 14 min, respectively. This study provided a rapid and sensitive μPen-ESI-MS/MS method for the assay of testosterone and dextromethorphan in liver microsome samples, and provided a new strategy for the evaluation of drug metabolism stability and CYP3A4/CYP2D6 activity.
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Decompression and curettage can result are effective as treatments for large jaw cysts, which are common diseases in the clinic. Based on a treatment used in a previous study, this paper proposes a "three-step method" to treat large jaw cyst and repair the bone defect by decompression, curettage, and autologous dental bone powder implantation. This paper introduces the processes and key points of the operation involved in the abovementioned method.
Subject(s)
Humans , Bone Cements , Bone Cysts , General Surgery , Bone Transplantation , Curettage , Jaw CystsABSTRACT
Objective: To establish HPLC fingerprints of Qiwei Tangmaishu tablet and simultaneously determine the contents of the six constituents, acteoside, martynoside, calycosin 7-O-β- D-glucopyranoside, schisandrin, formononetin and deoxyschizan- drin. Methods: The analysis of 50% methanol extract of this drug was performed on a 30℃ thermostatic Waters Symmetry C18 column, with the mobile phase comprising of acetonitrile(A)-0.2% formic acid solution(B)flowing at 1.0 ml/min in a gradient elution manner. The detection wavelength was set at 330 nm for acteoside and martynoside, 254 nm for calycosin 7-O-β-D-glucopyranoside, schisandrin, formononetin and deoxyschizandrin. Results: There were thirteen common peaks in the fingerprints of ten batches of samples with the similarities more than 0.9. Acteoside, martynoside, calycosin 7-O-β-D-glucopyranoside, schisandrin, formononetin and deoxyschizandrin showed good linear relationship within the ranges of 1.47-36.75, 0.66-16.50, 0.89-22.25, 2.58-64.50, 1.91-47.75 and 0.77-19.25 μg/ml(r≥0.9993), and their average recoveries were 97.57%, 99.22%, 96.69%, 100.01%, 98.79% and 96.77%, with the RSD of 0.79%, 1.54%, 0.61%, 0.64%, 0.83% and 0.36%, respectively. Conclusion: The established method is easily operable and repeatable, which could be used for quality control of Qiwei Tangmaishu tablet.
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BACKGROUND@#In recent years, a number of clinical trials have shown that immunocheckpoint inhibitors (ICI) have brought survival benefits to patients with advanced non-small cell lung cancer (NSCLC), however, such clinical trials comprise cohorts selected based on strict and complex entry and exclusion criteria, and the results cannot fully reflect the real world situation. The purpose of this study was to investigate the clinical efficacy and safety of immunotherapy in the real world, as well as possible prognostic factors.@*METHODS@#Patients with advanced NSCLC receiving immunotherapy in Beijing Chest Hospital from January 2017 to July 2019 were retrospectively collected, and the following information were collected: curative effect, progression-free surival (PFS) and adverse reactions. The occurrence of adverse reactions and clinical curative effect and prognosis factors that may be relevant were explored.@*RESULTS@#34 patients were enrolled in this study, median PFS was 5.66 months (95%CI: 4.48-6.84), grade 1-2 and 3-4 incidence of adverse events was 61.71% (22/34) and 14.71% (5/34), there were 3 patients (8.82%) experienced fatal immune related adverse events (irAE), 2 cases were immune associated pneumonia, 1 case was immune related myocarditis. Univariate analysis showed that tumor-node-metastasis (TNM) stage and metastatic site were correlated with median PFS (P<0.05), and multivariate analysis showed that patients with extrapulmonary metastasis (OR=6.42, P=0.029) and pleural metastasis (OR=14.14, P=0.006) had shorter median PFS.@*CONCLUSIONS@#In the real world, immunotherapy has good efficacy in patients with advanced NSCLC, but the incidence of severe irAE is also higher. Distant metastasis and pleural metastasis are poor prognostic factors for advanced NSCLC patients receiving immunotherapy.
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Laser-induced breakdown spectroscopy (LIBS) was used for analysis of the distribution of S,Mn,Fe,Cr,Mo,Si,Al in a 34CrNiMo6 steel sample cut from a main shaft of wind driven generator.The MnS inclusion area in each ablation craters cover zone was extracted in the way of comparing the metallograph captured by optical microscopy before and after LIBS scanning ablation.The statistic relation between MnS inclusion area and signal intensity of S and Mn was analyzed.The result showed that the abnormal signal of S and Mn occurred at the same position with the existence of MnS inclusion,and their signal intensity showed linear relationship.The abnormal signal of S and Mn were triggered mainly by MnS inclusion.The statistic result also showed linear relationship between signal intensity and MnS inclusion area both for S and Mn.It was possible to determine the inclusion type,size and distribution by analyzing abnormal signal.A simplified ablation model was established to calculate the relation of S and Mn content to MnS inclusion area.The arithmetic result showed a linear relation between the content and MnS inclusion area both for S and Mn.The calculation confirmed the linear relationship between signal intensity and inclusion area observed in experiment.The linear relationship could be interfered by macro-segregation,micro-segregation,deviation in measuring inclusion area,and inclusion spatter in pre-ablation.
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Objective: To observe the changes in numbers and degranulation status of local mast cells (MCs) of the complementary acupionts, as well as the concentrations of serum histamine and bradykinin after acupuncture at rat's complementary acupionts of Yanglingquan (GB 34) and Yinlingquan (SP 10), for exploring the mechanisms of the synergistic effect of complementary acupionts. Methods: Using random number table method, 40 Wistar rats were randomly divided into a blank control group (group K), an acupuncture at Yanglingquan (GB 34) group (group A), an acupuncture at Yinlingquan (SP 9) group (group B), an acupuncture at Yanglingquan (GB 34) and Yinlingquan (SP 9) group (group AB), and an acupuncture at points near Yanglingquan (GB 34) and Yinlingquan (SP 9) group (group CD), 8 rats in each group. Group A received acupuncture at Yanglingquan (GB 34); group B received acupuncture at Yinlingquan (SP 9); group AB received acupuncture at Yanglingquan (GB 34) and Yinlingquan (SP 9); group CD received acupuncture at the control points [points 3 mm away from Yanglingquan (GB 34) and Yinlingquan (SP 9) respectively]. Acupuncture was performed at bilateral points in each group. Rats in group K were fixed using the same method as rats in the other 4 groups without acupuncture stimulation. Needles of 0.35 mm in diameter and 40 mm in length were used for acupuncture. Needle handle was connected to the G6805-Ⅱ mode electroacupuncture (EA) device after needling qi was obtained, with sparse-dense wave, frequency of 2 Hz/100 Hz and current of 1 mA to keep the needle handles slightly tremulous while the rats kept quiet. Rats were continuously stimulated by EA for 20 min each time. Experimental interventions were conducted on the 1st, 3rd, 5th and 7th days when the experiment started, for 4 times in total. Specimens from rats in each group were collected 2 h after the 7th day. The levels of histamine and bradykinin in serum were detected by enzyme-linked immunosorbent assay (ELISA). Local tissues of the points were used to prepare cryosections. The changes of MCs were observed after toluidine blue staining. Results: Compared with group K, the numbers and degranulation rates of MCs in group A, group B, group AB and group CD were significantly increased (all P<0.05). The number and degranulation rate of MCs in group AB were significantly higher than those in group A, group B and group CD (all P<0.05). The order of histamine levels from high to low was: group AB >group B > group A > group CD > group K, and the differences were statistically significant (all P<0.05); the levels of bradykinin in group AB, group A and group B were significantly higher than those in group K and group CD (all P<0.05). There was no significant difference in the bradykinin level between group A and group B, nor between group CD and group K (all P>0.05). Conclusion: The number and degranulation rate of MCs of the complementary acupionts are significantly increased after acupuncture at complementary acupionts of Yanglingquan (GB 34) and Yinlingquan (SP 9) of rats, and the serum levels of histamine and bradykinin are increased, which may be one of the mechanisms of the synergism produced by the combination of complementary acupionts.
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Objective • To explore the feasibility of applying customized guide, based on digital image processing and 3D printing technology, to bone biopsy. Methods • Eleven patients (6 males and 5 females; 7-69 years old, average age of 36 years) diagnosed with bone tumor from July 2017 to March 2018 in Shanghai Ninth People's Hospital were enrolled in this study. Routine CT and/or MRI data were taken as reference in designing the customized biopsy guide for 3D printing by Medraw Print software. Needle insertion points were set under the supervision of surgeons to avoid damaging important anatomical structures such as nerves and blood vessels. 3D printed customized guide was designed to match local surface. The success of the puncture was confirmed by X-ray or CT, and the accuracy of the puncture results was evaluated by the pathological results of resection operation as a reference standard. The complications were analyzed. Results • The 11 patients included 4 cases with neoplasms in femur, 3 cases in pelvis, 2 cases in tibia, 1 case in scapula and 1 case in metacarpal. The needling positions in operation were consistent with the preoperative virtual design, and the guide plates fitted perfectly to the body surface. The results of biopsy of 8 patients (88.9%) matched with the postoperative pathology, while another 2 patients did not receive bone tumor resection because of the benign biopsy. No complications were observed during or after the procedure. Conclusion • Customized guide by digital image processing and 3D printing may have a great value in improving the accuracy of preoperative tumor diagnosis and the effectiveness of its treatment.
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Objective·To explore the value of applying CT/MRI image registration and fusion combined with 3D printing technique in pre-surgical planning of refractory pelvic tumors. Methods·A retrospective analysis was performed on the cases with refractory pelvic tumors admitted between March 2014 and December 2016 in Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine. CT/MRI examinations were performed as a routine pre-surgical procedure, and the resulting images were subject to rapid registration and fusion with the Medraw software in order to accurately determine the tumor boundaries and to be used as references in designing and making patient-specific tumor models, prostheses, and implants by 3D printing technique. Results·A total of 13 cases with refractory pelvic tumors were included in this study (8 cases of chondrosarcoma, 1 case of osteosarcoma with aneurysmal bone cyst, 1 case of dedifferentiated sarcoma, 1 case of fibrous connective tissue hyperplasia, 1 case of solitary fibrous tumor/hemangiopericytoma, and 1 case of metastatic squamous cell carcinoma) with an average age of (50.0±8.5) years. According to the Enneking classification,there were 2 cases in zone Ⅰ , 2 in zones Ⅰ + Ⅱ , 1 in zones Ⅱ + Ⅲ , 3 in zones Ⅰ + Ⅱ + Ⅲ , 1 in zones Ⅰ + Ⅱ + Ⅳ , 1 in zonesⅠ + Ⅱ + Ⅲ + Ⅳ , 1 in zones Ⅰ + Ⅳ , 1 in zones Ⅱ + Ⅳ , and 1 in zone Ⅳ. The mean maximal tumor diameter was (15.15±4.81) cm without implicating the pelvic blood vessels. Results from intraoperative frozen section at resection boundaries and the installation of prosthesis showed that the actual surgical procedure was consistent with the surgical planning based on the reported image fusion technique. Conclusion·CT/MRI image registration and fusion technique combined with 3D printing technique can accurately determine the resection boundary of pelvic tumors and assist in designing of individualized prosthesis model and surgical guide, which has a great value in pre-surgical planning and clinical treatment of refractory pelvic tumors.
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<p><b>OBJECTIVE</b>The influence of anti-tuberculosis (TB) treatment history on tuberculous lymphadenitis (TBLN) diagnosis is unclear. Therefore, this study aims to evaluate the diagnostic methods, including histology, microbiology, and molecular tests, used for TBLN.</p><p><b>METHODS</b>In this study, suspected patients with TBLN and having different anti-TB treatment background were enrolled. All the samples were tested simultaneously by histology, Ziehl-Neelsen (ZN) staining, mycobacterial culture (culture), Xpert MTB/RIF (xpert), real-time PCR, and high-resolution melting curve PCR (HRM). Thereafter, the performance of these methods on samples with different anti-TB treatment background was assessed.</p><p><b>RESULTS</b>In our study, 89 patients were prospectively included 82 patients with TBLN and 7 with other diseases. The overall sensitivities of Xpert, real-time PCR, histology, ZN staining, and culture were 86.6%, 69.5%, 58.5%, 43.9%, and 22.0%, respectively. The anti-TB treatment history revealed dramatic influences on the sensitivity of culture (P < 0.0001). In fact, the treatment that lasted over 3 months also influenced the sensitivity of Xpert (P < 0.05). However, the treatment history did not affect the performance of remaining tests (P > 0.05). For rifampicin drug susceptibility test (DST), the anti-TB treatment showed only significant influence on the success rate of culture DST (P = 0.001), but not on those of Xpert and HRM tests (P > 0.05).</p><p><b>CONCLUSION</b>Other tests as well as culture should be considered for patients with TBLN having retreatment history or over 1-month treatment to avoid false negative results.</p>
Subject(s)
Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Antitubercular Agents , Therapeutic Uses , Bacteriological Techniques , Drug Resistance, Bacterial , Tuberculosis, Lymph Node , Diagnosis , Drug Therapy , MicrobiologyABSTRACT
Objective Objective To analyze the torque performance of lingual brackets with slots in different directions and the influence pattern of arch wires with different sizes and materials on torque of these lingual brackets.Methods The finite element models of the anterior maxilla lingual brackets with vertical and horizontal slot were constructed,using 3 kinds of materials (stainless steel,beta-titanium,nickel-titanium) and two sizes of arch wires (0.43 mm x 0.56 mm,0.41 mm x 0.56 mm),so as to compare and analyze their mechanical properties after the application of torque load on the left upper central incisors with a rotation angle of ±20°.Results With the increase in elastic modulus of the arch wire,torque moments of lingual brackets with horizontal and vertical slot both increased gradually.Torque performance of lingual brackets was affected more by the sizes and materials of arch wires than the directions of slots.The lingual bracket with vertical slot produced 1-2 times of torque force than that with horizontal slot under the same degree of torque angle.The effect of arch wire sizes was smaller than that of arch wire materials,while the synergistic change in sizes and materials of arch wires had the largest influence on torque performance of lingual brackets.Conclusions The torque performance of lingual bracket will be influenced with its different slot directions,the sizes and materials of arch wires.In clinical application,slot directions of lingual brackets as well as sizes and materials of arch wires should be adjusted properly according to the required torque force.
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Objective Objective To analyze the torque performance of lingual brackets with slots in different directions and the influence pattern of arch wires with different sizes and materials on torque of these lingual brackets.Methods The finite element models of the anterior maxilla lingual brackets with vertical and horizontal slot were constructed,using 3 kinds of materials (stainless steel,beta-titanium,nickel-titanium) and two sizes of arch wires (0.43 mm x 0.56 mm,0.41 mm x 0.56 mm),so as to compare and analyze their mechanical properties after the application of torque load on the left upper central incisors with a rotation angle of ±20°.Results With the increase in elastic modulus of the arch wire,torque moments of lingual brackets with horizontal and vertical slot both increased gradually.Torque performance of lingual brackets was affected more by the sizes and materials of arch wires than the directions of slots.The lingual bracket with vertical slot produced 1-2 times of torque force than that with horizontal slot under the same degree of torque angle.The effect of arch wire sizes was smaller than that of arch wire materials,while the synergistic change in sizes and materials of arch wires had the largest influence on torque performance of lingual brackets.Conclusions The torque performance of lingual bracket will be influenced with its different slot directions,the sizes and materials of arch wires.In clinical application,slot directions of lingual brackets as well as sizes and materials of arch wires should be adjusted properly according to the required torque force.
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Objective:To investigate the effect of different postoperative nutritional support on the gastrointestinal function and nutritional status in acute colon peforation patients.Methods:60 cases of acute emergency operation patients with perforation of the colon,according to the given nutritional support treatment of the different ways,were divided into enteral parenteral joint nutrition (EN + PN) group and total parenteral nutrition (TPN) group.Clinical therapeutic effects of two groups were compared.Results:The results of EN + PN group were significantly better than the those in TPN group (P ＜ 0.05).Conclusion:EN + PN model can improve the postoperative nutritional status and accelerate the recovery of patients with acute colonic perforation.
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Objective·To explore the value of applying CT/MRI image registration and fusion combined with 3D printing technique in pre-surgical planning of refractory pelvic tumors. Methods·A retrospective analysis was performed on the cases with refractory pelvic tumors admitted between March 2014 and December 2016 in Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine. CT/MRI examinations were performed as a routine pre-surgical procedure, and the resulting images were subject to rapid registration and fusion with the Medraw software in order to accurately determine the tumor boundaries and to be used as references in designing and making patient-specific tumor models, prostheses, and implants by 3D printing technique. Results·A total of 13 cases with refractory pelvic tumors were included in this study (8 cases of chondrosarcoma, 1 case of osteosarcoma with aneurysmal bone cyst, 1 case of dedifferentiated sarcoma, 1 case of fibrous connective tissue hyperplasia, 1 case of solitary fibrous tumor/hemangiopericytoma, and 1 case of metastatic squamous cell carcinoma) with an average age of (50.0±8.5) years. According to the Enneking classification,there were 2 cases in zone Ⅰ , 2 in zones Ⅰ + Ⅱ , 1 in zones Ⅱ + Ⅲ , 3 in zones Ⅰ + Ⅱ + Ⅲ , 1 in zones Ⅰ + Ⅱ + Ⅳ , 1 in zonesⅠ + Ⅱ + Ⅲ + Ⅳ , 1 in zones Ⅰ + Ⅳ , 1 in zones Ⅱ + Ⅳ , and 1 in zone Ⅳ. The mean maximal tumor diameter was (15.15±4.81) cm without implicating the pelvic blood vessels. Results from intraoperative frozen section at resection boundaries and the installation of prosthesis showed that the actual surgical procedure was consistent with the surgical planning based on the reported image fusion technique. Conclusion·CT/MRI image registration and fusion technique combined with 3D printing technique can accurately determine the resection boundary of pelvic tumors and assist in designing of individualized prosthesis model and surgical guide, which has a great value in pre-surgical planning and clinical treatment of refractory pelvic tumors.
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Objective To analyze the torque performance of lingual brackets with slots in different directions and the influence pattern of arch wires with different sizes and materials on torque of these lingual brackets. Methods The finite element models of the anterior maxilla lingual brackets with vertical and horizontal slot were constructed, including three kinds of materials (stainless steel, beta-titanium, nickel-titanium) and two sizes of arch wires (0.43 mm×0.56 mm, 0.41 mm×0.56 mm), so as to compare and analyze their mechanical properties after the application of torque load on the left upper central incisors with a rotation angle of ±20°. Results With the increase in elastic modulus of the arch wire, torque moments of lingual brackets with horizontal and vertical slot both increased gradually. Torque performance of lingual brackets was affected more by the sizes and materials of arch wires than the directions of slots. The lingual bracket with vertical slot produced 1-2 times of torque force than that with horizontal slot under the same degree of torque angle. The effect of arch wire sizes was smaller than that of arch wire materials, while the synergistic change in sizes and materials of arch wires had the largest influence on torque performance of lingual brackets. Conclusion The lingual brackets with different slot directions, sizes and materials of arch wires will influence the torque performance of lingual brackets. In clinical application, slot directions of lingual brackets as well as sizes and materials of arch wires should be adjusted properly according to the required torque force.
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Objective To evaluate the effect of 3D printing models applied to Medical Imaging Di-agnosis Undergraduate Teaching. Methods Students in the year 2012/2013 of Shanghai Jiao Tong Univer-sity School of Medicine stomatology specialty were chosen for this study, including 38 students in the exper-imental group (2013) and 40 students in the control group (2012). All of them were taught by the same group of teachers, including 28 core curriculum hours and 5 practice class hours. 3D printing technology with PPT was applied to the experimental group in the medical imaging diagnostic teaching, and conventional teaching including PPT and usual models in the control group. Medical students were given a test about cardiovascular system and tasked with completion of drawing hand and foot bones. Students in experimental group were also asked to complete a questionnaire about their experience. Results The questionnaire showed that 3D printing teaching molds with PPT was of great significance to improve the students interest in learning imaging anatomy, to meet the vast majority of students' learning requirements, and to achieve satis-factory results. The average scores of the circulatory system test in the experimental group were higher than that of the control group [(8.32 ±2.352) vs. (6.15 ±1.284), P<0.05)]. Students in experimental group per-formed better than students in the control group on the Locomotor system test [(6.81 ±1.347] vs. (3.84 ± 0.985), P<0.01]. Conclusions 3D printing mold combined with PPT teaching method can promote the med-ical imaging anatomy structure, learning effect and teaching quality, and has practical value in the under-graduate teaching of medical imaging diagnosis.
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Objective Objective To analyze the torque performance of lingual brackets with slots in different directions and the influence pattern of arch wires with different sizes and materials on torque of these lingual brackets.Methods The finite element models of the anterior maxilla lingual brackets with vertical and horizontal slot were constructed,using 3 kinds of materials (stainless steel,beta-titanium,nickel-titanium) and two sizes of arch wires (0.43 mm x 0.56 mm,0.41 mm x 0.56 mm),so as to compare and analyze their mechanical properties after the application of torque load on the left upper central incisors with a rotation angle of ±20°.Results With the increase in elastic modulus of the arch wire,torque moments of lingual brackets with horizontal and vertical slot both increased gradually.Torque performance of lingual brackets was affected more by the sizes and materials of arch wires than the directions of slots.The lingual bracket with vertical slot produced 1-2 times of torque force than that with horizontal slot under the same degree of torque angle.The effect of arch wire sizes was smaller than that of arch wire materials,while the synergistic change in sizes and materials of arch wires had the largest influence on torque performance of lingual brackets.Conclusions The torque performance of lingual bracket will be influenced with its different slot directions,the sizes and materials of arch wires.In clinical application,slot directions of lingual brackets as well as sizes and materials of arch wires should be adjusted properly according to the required torque force.
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Objective To analyze the mechanical properties of V-bends with different materials, sizes of arch wires, angles, shapes, inter-bracket distances by using finite element method, so as to provide references for clinical practice of V-bends. Methods The finite element models of V-bends were established, including two kinds of materials (stainless steel, titanium-molybdenum alloy), two sizes（0.43 mm×0.64 mm, 0.48 mm×0.64 mm）, two V-bend positions, two angles(150°, 165°),and two inter-bracket distances（7,10 mm）, so as to compare and analyze their mechanical properties after simulative loading. Results The maximum force values produced by V-bends with stainless steel arch wire were greater than that of V-bends with β titanium steel arch wire. The force produced by V-bends with 0.43 mm×0.64 mm arch wire was smaller than that produced by V-bends with 0.48 mm×0.64 mm arch wire. The size of arch wire had a more obvious impact on V-bends with symmetrical arch wire. The force of V-bends with asymmetric arch wire was more evidently influenced by the change of inter-bracket distance. For V-bends with the same shape, the smaller the V-shaped angle, the greater the force on the bracket would be. Conclusions The V-bends with different materials, different sizes of arch wires, different shapes and inter-bracket distances will have different mechanical behaviors. In clinical application, the materials, sizes of arch wires, shapes and angles of V-bends should be adjusted properly according to the inter-bracket distances.
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BACKGROUND:In the orthodontic treatment, double wire technique is commonly used to correct the torque of anterior teeth;however, the underlying mechanical mechanisms remain unclear. OBJECTIVE:To study the torque capabilities of DamonQ system through the three-dimensional finite element method. METHODS:Three-dimensional finite element models of Damon Q brackets with different dimension arch wires were established and were grouped according to arch wire with different dimensions. The torque capabilities of Damon Q system with different dimensions and materials arch wire were analyzed. RESULTS AND CONCLUSION:The Damon Q brackets with single or double wires had the same variation of torque, torque angle curve changes under the condition of different size and material arch wires. Torque moment increased gradually with increasing torque angle. Rectangular-round double wires produced larger torque moment compared with single rectangular wire, whereas double round wires produced smal er torque moment compared with single rectangular wire. The torque moment produced by rectangular-round double wires or by single rectangular wire was approximately 2-8 times or 1-5 times more than that by double round wires. The torque moment that rectangular-round double wires produced was larger than that single wire produced in the DamonQ system. In the early clinical practice, we can use double round wires to control root movement. In the middle-term of the treatment, we can use rectangular-round double wires to control root movement as the mild forces produced by them reduce root absorption. This study lays a foundation for the application of Damon Q bracket with double wire technology in the clinic.