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91.
Ludvigsson JF Welander A Lassila R Ekbom A Montgomery SM 《British journal of haematology》2007,139(1):121-127
The risk of venous thromboembolism (VTE) was examined in individuals with coeliac disease (CD). The Swedish national inpatient register was used to identify 14 207 individuals with a diagnosis of CD (1964-2003). These individuals were matched for age, sex, calendar year and county with 69 048 reference individuals. Cox regression was used to estimate hazard ratios (HRs) for subsequent thromboembolism in individuals with more than 1 year of follow-up and no prior VTE. CD was associated with an increased risk of subsequent VTE (HR = 1.86; 95% confidence interval (CI) 1.54-2.24). The risk increase was restricted to individuals with CD diagnosed in adulthood. Risk estimates were not affected by the presence of diabetes mellitus or concomitant surgery. Compared with inpatients as reference individuals, CD individuals remained at increased risk of subsequent VTE (adjusted HR = 1.27; 95% CI = 1.06-1.52). In conclusion, this study found a statistically significantly positive association between CD and VTE. This modest association might be explained by a combination of surveillance bias and chronic inflammation. 相似文献
92.
OBJECTIVES: Longevity of particulate filler resin (PFR) is controversial for large restorations with high occlusal-stresses. The aim of this study was to reinforce PFR with fiber reinforced composite (FRC) and to evaluate the effect of thickness of FRC substructure and thickness of overlaying PFR, on the static load-bearing capacity of the material combination. METHODS: A total of 336 test specimens having a FRC substructure (short random or continuous bidirectional fibre orientation) and layer of restorative PFR were prepared for this study. In Group A, the specimens contained short random oriented fibres (length: 2-3mm) and in Group B, there were continuous bidirectionally oriented fibres. The specimens (n = 12/group) were polymerized with a hand light-curing unit and were either dry-stored or thermocycled before they were statically loaded with a steel ball until fracture, using a universal testing machine. RESULTS: Increase the volume fraction of the short random FRC versus the fraction of PFR, the load-bearing capacity of the specimen increased (p < 0.001). Short random FRC revealed significantly different behavior than the bidirectionally oriented FRC (p < 0.001). By combining the FRC layer of 0.5mm in thickness with a layer of 2.5mm of PFR gave load values of 1462N and 1196N, which were considerably higher than values for plain PFR of 3mm in thickness (782N and 729N). CONCLUSION: The results suggest that by adding a FRC substructure under the PFR, the load-bearing capacity of the material combination was increased. 相似文献
93.
Garoushi SK Lassila LV Tezvergil A Vallittu PK 《The journal of contemporary dental practice》2006,7(4):1-8
AIM: The aim of this study was to determine the static load-bearing capacity of composite resin onlay restorations made of particulate filler composite (PFC) with two different types of fiber-reinforced composite (FRC) substructures. In addition, flexural properties of the material combination and the effect of polymerization devices were tested. METHODS AND MATERIALS: Specimens were prepared to simulate an onlay restoration, which consisted of 2 to 3 mm of FRC layer as a substructure (short random and continuous bidirectional fiber orientation) and a 1 mm surface layer of PFC. Control specimens were prepared from plain PFC. In Group A the specimens were incrementally polymerized only with a hand-light curing unit for 40 s, while in Group B the specimens were post-cured in a light-curing oven for 15 min before they were statically loaded with a steel ball. Bar-shaped test specimens were prepared to measure the flexural properties of material combination using a three-point bending test (ISO 10477). RESULTS: Analysis of variance (ANOVA) revealed all specimens with a FRC substructure have higher values of static load-bearing capacity and flexural properties than those obtained with plain PFC (p<0.001). CONCLUSION: The load-bearing capacity of all the specimens decreased after post-curing and water storage. Restorations made from a material combination of FRC and PFC showed better mechanical properties than those obtained with plain PFC. 相似文献
94.
Ritva M. Lindblad Lippo V.J. Lassila Veijo Salo Pekka K. Vallittu Leo Tjäderhane 《Journal of dentistry》2010
Objectives
Chlorhexidine is used as final irrigant before endodontic obturation and fiber-reinforced composite posts are recommended for restoration retention. Our aim was to evaluate the effect of chlorhexidine on adhesion of cements used in post cementation. We hypothesized that chlorhexidine would not negatively affect the immediate bond strength.Methods
Root canals of eighty human extracted third molars were prepared for post cementation with each post systems’ own burs. Four commercially available FRC posts (Glassix, D.T.Light-Post, Unicore, everStickPOST) with three cements (Duo-link with All-bond 2, PermaFlo DC with PermaFlo DC Primers, RelyX Unicem) were used. After etching, except with self-etching RelyX Unicem, the post spaces were irrigated either with 2% chlorhexidine (Consepsis) or physiological saline for 60 s. With RelyX Unicem, respective treatments were done before cement application. The roots (n = 5 per group) were cut into 2 mm thick dentin discs. The bond strength was measured with push-out method, and the failure mode was evaluated with a stereomicroscope.Results
Significant differences in bond strength were observed between various post/cement combinations. Unicore/PermaFlo DC and everStickPOST/RelyX Unicem showed significantly higher bond strengths than Glassix or D.T.Light-Post with Duo-link both with saline and chlorhexidine. Chlorhexidine improved the bond strength slightly with all posts/cements except with D.T.Light-Post, but the differences were not statistically significant. With chlorhexidine, significant reduction of adhesive failures towards dentin cohesive or mixed failures was observed with all posts/cements except with everStickPOST.Conclusion
Chlorhexidine did not negatively affect the push-out bond strength in post bond cementation. 相似文献95.
96.
L. Jartti T. Rönnemaa O. T. Raitakari E. Hedlund N. Hammar R. Lassila J. Marniemi M. Koskenvuo J. Kaprio 《Journal of internal medicine》2009,265(3):345-358
Background. Study of migrants offers a natural model to assess environmental risk of coronary heart disease (CHD) in countries differing in CHD occurrence. In Sweden, CHD risk has been markedly lower than in Finland from where a large migration occurred in the 1970s. Objectives. To study the structural and functional markers of subclinical atherosclerosis in twin pairs discordant for migration with the main focus on age at migration, length of residence and integration into Swedish society after migration from a high to a lower CHD risk country. Methods. Carotid intima‐media thickness (IMT) and brachial artery endothelial function (EF) were assessed with high‐resolution ultrasound and a set of cardiovascular, socio‐economic and psychosocial risk factors were estimated in 76 middle‐aged male twin pairs discordant for migration from Finland to Sweden. Results. Men who had migrated in adolescence had lower IMT values compared with their co‐twins living in Finland (0.665 ± 0.114 vs. 0.802 ± 0.167 mm, P = 0.009). Also men who integrated well to Swedish society had lower (0.720 ± 0.154 vs. 0.799 ± 0.207 mm, P = 0.013) IMT values than their twin brothers living in Finland. Associations between IMT and migration age and between IMT and integration remained significant in multivariate analyses of several CHD risk factors. The intrapair difference in IMT was significantly associated with immigration age and integration (anova , P = 0.0082), the difference being greatest among pairs where the brother living in Sweden had migrated at early age and integrated well to Swedish society. EF was better in men who had migrated to Sweden before the age of 21 years, but not later, compared with their co‐twins in Finland (6.4 ± 4.6% vs. 3.8 ± 3.6%, P = 0.025). Conclusions. Migration at an early age and good integration are beneficial to vascular health associated with moving from a high to a lower CHD risk country, suggesting that an environment‐sensitive period influences atherogenesis before adulthood. 相似文献
97.
Aki Hasegawa Akikazu Shinya Lippo V. J. Lassila Daiichiro Yokoyama Yuji Nakasone Pekka K. Vallittu Akiyoshi Shinya 《Odontology / the Society of the Nippon Dental University》2013,101(2):210-215
The aim of this study is to evaluate the accuracy of dental ceramic object three dimensional (3D) finite element model constructed directly from two different dental cone beam computed tomography (CT) systems. CT scanned one 10.0 × 10.0 × 20.0 mm block and one 8.0 × 10.0 × 40.0 mm block of an 8-step wedge. All 3D finite element (FE) models were created from CT images. Each 3D FE model measured the length of the directions X, Y, and Z that corresponded to an original specimen using the measurement function between two points on the Mechanical Finder software package. The measurements and practical value were compared with the CT image and the accuracy of the reproduced measurements was examined. No significant differences were found between Alphard-3030 on the Z axis and ProMax 3D on the Y axis of the block. In addition, there were also no significant differences observed between Alphard-3030 on the Y axis and ProMax 3D on the X axis compared with Alphard-3030 on the Z axis and ProMax 3D on the Y axis for the step-wedge. The results suggest that measurement of the dimensions of cone beam CT images could be useful in applications where both good reproducibility and accuracy of FE models are required. 相似文献
98.
99.
100.
An in vitro method for organ culture of embryonic bursa of Fabricius is presented. It is shown that bursa cells proliferate in in vitro culture as evidenced by [3H]-thymidine incorporation. We assessed the expression of B-cell alloantigen (Bu-la and Bu-lb), class I (B-F) and class II (B-L) antigens of chicken major histocompatibility complex (MHC), and surface immunoglobulin (sIg) on cultured bursa cells using specific monoclonal antibodies (mAb). Cells from 13-day and 14-day embryonic bursae incubated in organ culture for 1 to 2 weeks developed characteristic patterns of surface phenotype observed in adult chicken except for B-F antigen, whose expression was much lower than in vivo. These results indicate that the maturation of bursa cells in organ culture follows the in vivo development, except for the expression of MHC class I antigens. Furthermore, we demonstrate the in vitro repopulation of bursae from cyclophosphamide(cy)-treated chickens by cells from Bu-l antigen disparate normal bursae. 相似文献