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Atherosclerotic plaque rupture is the main cause of many cardiovascular diseases, and biomechanical factors play an important role in the process of plaque rupture. In the study of plaque biomechanics, there are relatively few studies based on fatigue fracture failure theory, and most of them mainly focus on the whole fatigue propagation process from crack initiation to plaque rupture, while there are few studies on the influence of crack on plaque rupture at a certain time in the process of fatigue propagation. In this paper, a two-dimensional plaque model with crack was established. Based on the theory of fracture mechanics and combined with the finite element numerical simulation method, the stress intensity factor (SIF) and related influencing factors at the crack tip in the plaque were studied. The SIF was used to measure the influence of crack on plaque rupture. The results show that the existence of crack can lead to local stress concentration, which increases the risk of plaque rupture. The SIF at the crack tip in the plaque was positively correlated with blood pressure, but negatively correlated with fibrous cap thickness and lipid pool stiffness. The effect of the thickness and angle of lipid pool on the SIF at the crack tip in the plaque was less than 4%, which could be ignored. This study provides a theoretical basis for the risk assessment of plaque rupture with cracks.
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Humans , Biomechanical Phenomena , Computer Simulation , Plaque, Atherosclerotic , Stress, MechanicalABSTRACT
Background and purpose:Head and neck cancer is common worldwide. This article aimed to describe the patterns of incidence of head and neck cancer and their changes in Shanghai from 2003 to 2012, in order to provide reference for prevention programs, research and control strategies on cancer.Methods:The data of lip, oral cavity and pharynx cancer cases were collected by the Shanghai Cancer Registry. The distributions of Shanghai lip, oral cavity and pharynx cancer incidences from 2003 to 2012 were described. The patterns were described according to gender, age, basis of diagnosis, histological type, diagnostic stage in detail. We compared incidences of recent 5 years (from 2008 to 2012) with those of previous 5 years (from 2003 to 2007).Results:On average from 2003 to 2012, 1105 new cases of head and neck cancer were diagnosed in Shanghai each year, with 2.08% among the total cancer cases. The crude rate was 8.01 per 100000 and the age-standardized rate was 4.45 per 100000. Nasopharyngeal cancer was the major subtype of the head and neck cancer, with 50.81% among the total head and neck cases. The crude and age-standardized rates among males were higher than those among females. The histologically verified percentage was 85.77%. The squamous carcinoma was the major histological type, with 57.58% among the total cases. The age-stan-dardized rate of nasopharyngeal cancer was in decline.Conclusion:The incidence of head and neck cancer was low in Shanghai during the past 10 years. Male cases were more than female cases. The major histological type was squamous carcinoma. Half of new cases were nasopharyngeal cancer which appeared to affect patients at a relatively young age. Patients with nasopharyngeal cancer were diagnosed at relatively advanced stages.
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BACKGROUND: As a blood concentrate rich in growth factors and fibrin, platelet-rich fibrin (PRF) is able to significantly promote bone regeneration. PRF mixed with bone substitutes is commonly used to repair bone defects in oral maxillofacial region. But it remains controversial whether PRF as a sole material in sinus floor elevation can produce enough new bone tissues.OBJECTIVE: To evaluate the osteogenic potential of PRF as a sole grafting material in sinus floor elevation by means of an animal model.METHODS: Twelve healthy adult mongrel dogs aged 12-18 months were selected and randomized into three groups (groups A, B and C), with four dogs in each group. Upper first molars on both side of each dog were extracted 12 weeks prior to sinus floor elevation and simultaneous implants placement. Different materials were used to fill in the space between the sinus membrane and implant. Groups A, B and C were filled with PRF, autologus bone particles and autologus blood clot respectively. After 12 weeks, specimens were harvested to analyze the new bone formation by gross observation, X-ray examination and histological evaluation.RESULTS AND CONCLUSION: New bone formation was found to embrace all the implants close to the bony sinus floor, and the tips of all implants were free from bone coverage. The new bone height of groups A, B and C were (3.135±0.288),(3.218±0.345), and (1.898±0.157) mm, respectively. The new bone density of groups A, B and C were (65.06±5.88),(75.34±8.18), and (56.92±4.95) g/cm3, respectively. There were significant differences between the new bone height in groups A and C as well as in groups B and C (P < 0.05). Also, significant differences were found between the new bone density in groups A and B, B and C, A and C (P < 0.05). Within the confine of this experiment, it is feasible to use PRF as a sole grafting material in the sinus floor elevation to generate new bone, but the new bone volume is limited.
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Objective@#To analyze the patterns of female breast cancer and their incidence in Shanghai during 2003-2012, and to compare them with international data.@*Methods@#The data of female breast cancer cases diagnosed between 2003 and 2012 were collected from the Shanghai Cancer Registry. The record of cancer cases included the patient's name, gender, date of birth, permanent and residential address, diagnosis site or name, histological type, date of first diagnosis, diagnostic basis and diagnostic stage, etc. Data source of cancer incidence of World, Developed Countries, Developing Countries, East Asia and China in 2012 sourced from GLOBOCAN 2012 database of the WHO International Agency for Research on Cancer (IARC); and the data of USA during 2008-2012 was collected from SEER 18 database from Surveillance, Epidemiology, and End Results Program of the National Cancer Institute (NCI). Incidence indicators of Shanghai female breast cancer were calculated, including the average cases, median age, average age, proportion, crude rate, age-specific rate and age-standardized rate.@*Results@#During 2003-2012, 41 991 new cases of female breast cancer were diagnosed in Shanghai, with an average of 4 199 cases per year, accounting for 17.23% among total new female cancer cases, ranking first in female cancer incidence in Shanghai during 2003-2012, with a crude incidence rate of 60.90 per 100 000 and an age-standardized incidence rate of 33.90 per 100 000. During 2008-2012, an average 4 528 new cases of female breast cancer was diagnosed per year in Shanghai, with 16.97% among total female cancer cases. The median age was 56 years old and the mean age was 57.73 years old. The crude rate was 64.23 per 100 000 and the age-standardized rate was 35.00 per 100 0000, which was higher than those of China (22.1 per 100 000), Eastern Areas (27.0 per 100 000) and Developing Counties (31.3 per 100 000), and lower than that of World (43.1 per 100 000), and Yellow Race Population of USA (68.77 per 100 000). During 2003-2007, on average, 3 869 new cases of female breast cancer were diagnosed per year in Shanghai, accounting for 17.54% of total female cancer cases. The median age was 53 years old and the mean age was 56.44 years old. The crude rate was 57.42 per 100 000 and the age-standardized rate was 32.69 per 100 000. There was a continuing peak stage spanned 25 years old from 50 to 74 years old, during 2008-2012. Compared with those of 2003-2007, the beginning age group of the continuing peak stage was delayed for 5 years old and the ending age group was delayed for 10 years old.@*Conclusion@#The age-standardized incidence rate in Shanghai was higher than those of China, Eastern Areas and Developing Counties, and lower than that of World, and that of Yellow Race Population of USA; Compared with 2003-2007, the crude rate and age-standardized rate increased, the median age, mean age and the beginning and ending age group of the continuing peak stage were delayed.
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<p><b>OBJECTIVE</b>To understand the incidence trend of malignant tumors in children aged <15 years in Shanghai.</p><p><b>METHODS</b>The <15 years old children diagnosed with cancer in Shanghai between 2009 and 2011 were included in this study. The types of malignant tumors were classified according to International Classification of Childhood Cancer, Version 3 (ICCC-3). The gender and age specific incidences of malignant tumors were analyzed. Software Joinpoint was used to calculate the annual percentage of childhood cancer cases.</p><p><b>RESULTS</b>A total of 460 cases of childhood cancer were diagnosed in Shanghai during 2009-2011, accounting for 0.3% of total cancer cases. The crude incidence was 129.0 per million and the age standardized rate (ASR) was 129.6 per million. The ASR was higher in boys (142.1 per million) than in girls (116.4 per million). The boy to girl ratio was 1.2(95%CI: 1.0-1.5). The incidence was highest in age group <5 years (165.1 per million). The incidences in age groups 5-9 years and 10-14 years were 101.2 per million and 113.9 per million, respectively. Leukemia was the most common cancer in children (n=165, 35.9%, ASR: 47.0 per million), followed by central nervous system tumors (n=91, 19.8%, ASR: 25.6 per million) and lymphomas (n=45, 9.8%, ASR: 12.6 per million). The age and gender specific incidence of malignant tumors and the type specific incidence of malignant tumors in children in Shanghai had no significant changes during the study period.</p><p><b>CONCLUSIONS</b>The incidence of malignant tumors was higher in boys than in girls in Shanghai. Leukemia, central nervous system tumors and lymphomas were the three most common cancers in children. The overall incidence of malignant tumors in children in Shanghai had no significant changes during 2002-2011.</p>
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Adolescent , Child , Child, Preschool , Female , Humans , Male , China , Epidemiology , Incidence , Neoplasms , EpidemiologyABSTRACT
BACKGROUND:Autologous bone marrow aspirate concentrate is often applied in patients from Department of Orthopedics and those with severe limb ischemia, but rarely applied in Department of Oral and Maxil ofacial Surgery, especial y in Department of Oral Implantology. The effect of autologous bone marrow aspirate concentrate on promoting peri-implant bone regeneration deserves further studies. OBJECTIVE:To evaluate the effect of bone marrow aspirate concentrate in the repair of peri-implant bone defect. METHODS:Bone marrow 5 mL was extracted from posterior superior iliac spine of experimental dogs and bone marrow cel s were counted before and after concentration. Bone defect (4 mm × 4 mm × 4 mm) was prepared in the middle of bilateral mandibular premolar, which was randomly implanted with gelatin sponge plus bone marrow aspirate concentrate, autologous bone and gelatin sponge. At 4 and 12 weeks after surgery, bone defect specimens were histological y observed. The new bone formation rate and new bone mineral density were calculated. RESULTS AND CONCLUSION:After centrifugation, the concentrations of nucleated cel s in bone marrow aspirate concentrate were increased by (2.78±0.22) times. More colony-forming units were found after cel culture. Histological analysis showed that, significantly higher new bone formation rate and new bone mineral density occurred in gelatin sponge plus bone marrow aspirate concentrate group, compared with autologous bone group and gelatin sponge group at 4 weeks (P0.05). Autologous bone marrow aspirate concentrate can significantly improve new bone mineral density and quantity in the pre-implant bone defect.
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OBJECTIVE To investigate the nuclear proteomes in mitochondrial DNA (mtDNA)-depleted A549 cells (Rho0 cells) and their parental cells (Rho+ cells),and to learn more about the nuclear responses to mitochondrial dysfunction.METHODS The nuclear proteomes of Rho and Rho + cells were characterized by two dimensional electrophoresis (2-DE) and SELDI-TOF ProteinChip technologies,the differentially expressed protein- spots were identified by MALDI-TOF mass spectrum (MS),the nucleophosmin and P53 expression were detected by Western blotting assay,and the mitochondrial memhrane potential (MMP) was measured by the laser scanning confocal microscope.RESULTS 2-DE results showed 11 protein-spots were down-regulated and 21 protein-spots were up-regulated in Rho0 cell nuclei.SELDI-TOF MS analysis with NP20 ProteinChips revealed 4 protein-peaks decreased in Rho0 cell nuclei.One down-regulated protein-spot was identified as elF-6,and 4 up-regulated proteinspots were identified as nucleophosmin,SFRS1,SFRS3 and hnRNP G,respectively.The increased expression of nucleophosmin in Rho0 cells was verified by Western blotting.Based on the clues from proteomic analysis,P53 expression in Rho0 cells was higher than in Rho + cells,and MMP was consistent in Rho + and Rho0 cells.CONCLUSION mtDNA-depletion induces nuclear proteome alteration.Rho0 cells can be used as a model to study the crosstalk between mitochondrion and nucleus.
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Guided bone regeneration technique (GBR) is regarded as one of the most important methods to increase the bone amount of alveolar ridge, which is often recommended to be applied in the dental implantation surgery. Barrier membrane is utilized in GBR technique to cover the bone defect and create a secluded space, which prevents the connective tissue from growing into the space and facilitates the growth priority of bone tissue. In recent years, along with the emerging of different kinds of barrier membranes and bone grafting materials, the scope of clinical application of this technology is continuously expanded. This article reviews the classification and property of the membranes and the application situation of guided bone regeneration technology in the field of dental implantation.
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In order to adapt to the development of society,an innovative talent cultivation system has been explored to train stomatological specialists with active innovation spirit and strong ability to practise.
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Objective: To investigate the effects of Nd:YAG laser in the treatment of dentine hypersensitivity. Methods:270 teeth in 153 patients were equally divided into two groups at random. The teeth in the experimental group were treated with Nd:YAG laser at 265.5 J/cm 2 (0.75 W and 10 Hz for 2 min) for 3 times with the interval of 1 week, those in the control group were treated with Gluma desensitizer for 3 times with the interval of 2 d. Results:The effective rate of the experimental and control groups was 92.59% and 49.62% respectively (P
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ve To study the way of oxidative stress induced by soot rat pulmonary cells type Ⅱ ?Methods Before exposure to soot extracts, the rat pulmonary cells were pretreated with anti-oxidative agent, N-acetylcysteine (NAC), vitamin C, vitamin E and mannitol for 30 minutes, then the ceils were exposed to the soot extracts for 24 hours. MTT assay was applied to detect the cytotoxicity. Results It showed that NAC, vitamin C and vitamin E could reduce the cytotoxicity of rat pulmonary cell caused by soot, but no same change was observed in that of man-nitol. Conclusion It was suggested that the DNA oxidative stress of soot may be caused by multi-ways, such as in-duction of oxygen free radical and lipid peroxide etc.