Stress concentration in adhesively bonded joints, which is considered a major factor affecting their strength, can be avoided by tailoring the material properties of the adhesives using a ...functionally graded adhesive (FGA). The material properties of second-generation acrylic (SGA) adhesives can be simply changed by changing the mixing ratio of the agents. However, the superiority of FGA joints using SGA adhesives has not been experimentally clarified yet. Therefore, in this study, a shear strength test and a constant load low-cycle shear test were conducted on single lap joint (SLJ) specimens tailoring the adhesive layer stepwise. The FGA specimen was compared with the non-tailored specimens using stiff or flexible adhesives. The SLJ test results showed 16% improvement in the joint strength by stepwise tailoring of the adhesive layer. Additionally, the difference in the strain distributions among the different adhesive layers was investigated via a digital image correlation (DIC) method, and the shear strain at the edge of the FGA specimen was more than 40% decreased compared to the non-tailored specimen using the flexible adhesive. The low-cycle test results also showed the superiority of the FGA specimen to the other specimens. The FGA specimen held up more than 4 times the number of cycle of other specimens with an applied load of 18 kN or more. This was attributed to the suppressed plastic deformation at the edges of the adhesive layer owing to the introduction of FGAs.
Although perianal fistulas occur commonly in pediatric Crohn's disease (CD), evaluations of health services have been limited since no validated claims-based methods exist for identifying cases.
To ...develop and validate accurate case definitions for perianal fistulas among pediatric patients with CD from administrative claims.
Retrospective cohort study in which we developed and tested candidate case definitions for perianal fistula. Patients (age 5-21 years between 2005-2012) with CD enrolled in Michigan Medicaid with healthcare at University of Michigan were identified via claims. Medical records were obtained from all identified patients, whose entire records were abstracted. Medical record evidence for perianal fistula was considered the "gold standard" against which candidate case definitions were compared. The reference case definition of perianal fistula (ICD9 565.1) and candidate case definitions were evaluated.
Of 843 patients identified via claims, 274 (33%) met CD criteria for inclusion. The true perianal fistula rate among CD patients was 18% (n = 49). The top-performing candidate case definition identified 15% (n = 42), had sensitivity of 77.6%, specificity of 98.2%, positive predictive value (PPV) 90.5%, negative predictive value (NPV) 95.3%, and area under receiver operator characteristic curve (ROC) of 0.88. In contrast, the reference case definition identified 9% (n = 26), sensitivity 51.0%, specificity 99.6%, PPV 96.2%, NPV 90.3%, and had an area under ROC of 0.75.
We demonstrated that it is feasible to use administrative claims data to accurately identify pediatric patients with perianal fistula complications. Claims-based case definitions were found to be highly accurate through medical record review, providing a high degree of confidence for future studies where chart review is not feasible. These claims-based methods can be applied to claims data in other settings for the evaluation of health services utilization as well as to assess the comparative effectiveness of prevention and treatment strategies.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A novel method to manufacture functionally graded adhesive joints that is easier to implement than previous methods is proposed and investigated in this study. For this method, a mixture of two ...adhesives, one that is rigid and brittle and one that is flexible, was applied to adherends with various mixing ratios. Second generation acrylic adhesives (SGAs) were used in this study because they can be cured at a wide range of mixing ratios. To evaluate the mechanical properties of the resulting adhesive mixtures, bulk specimens with different mixing ratios were prepared and tested. Each of the adhesives had two components (e.g., agents A and B), with similar chemical compositions, but agent A includes an oxidizer, and agent B includes a reducer. Thus, mixing of both agents A does not produce any chemical reaction and similarly for agents B; this property enabled us to perform honeymoon adhesion. A mixture of agents A was applied to the surface of an adherend, and a mixture of agents B was applied to that of the other adherend at various mixing ratios. Then, one of the adherends was placed onto the other to make a joint. After the joint cured, the hardness of the adhesive layer was evaluated at certain points on the surface using nano-indentation to verify the applicability of the proposed method. Based on bulk tensile tests, it was concluded that the mechanical properties of SGAs could be controlled by changing the mixing ratio of the SGAs. In addition, the results of the hardness test of the adhesive layer, which corresponds to the Young's modulus of the material, depended strongly on the mixing ratio of adhesive.
A method for fabricating adhesively bonded joints with graded properties along the bond-line was proposed. By utilizing two types of acrylic adhesives, one hard and the other soft, the properties of ...the mixture were changed by controlling the mixing ratio. An applicator for the adhesives was developed and used for the experiments, in which property-graded adhesive layers were actually produced. The properties, i.e., stress-strain curves at various points of the property-graded adhesive layer, were experimentally measured, and the validity of the proposed method was confirmed. The Young's moduli at multiple points of the adhesive layer changed from 34.7 MPa to 634 MPa by changing the mixing ratio of the adhesives.
Background/Aim: In endometrial cancer (EC), lymph node (LN) metastasis significantly impacts prognosis. Thus far, no studies have reported the molecular genetics of each metastatic lesion. This study ...aimed to investigate the molecular characteristics of primary and metastatic LNs and their association with clinical outcomes. Patients and Methods: The clinicopathological and molecular characteristics of 33 patients with EC with regional LN metastasis (FIGO stage IIIC) were investigated; we evaluated the mutational status of p53 and DNA mismatch repair (MMR) proteins in the primary lesion, all the positive LNs (102 lesions), mutational variation between primary and paired metastatic lesions, inter-lesion heterogeneity, and their association with clinical outcomes. Results: Immunohistochemically, 12 patients (36.4%) displayed aberrant p53 expression in metastatic lesions, and a concordant rate of 93.4% was observed between primary and metastatic lesions. Inter-lesion heterogeneity was observed in 20 cases (60.6%). In Kaplan–Meier analysis, patients with aberrant p53 expression in metastatic LNs exhibited worse progression-free survival (PFS) than those with wild-type p53 expression (p=0.008). Wild-type p53 expression in primary lesion with inter-lesion heterogeneity had a significantly worse PFS (p=0.049) than those without heterogeneity. In the Cox univariate analysis, p53 expression in metastatic LNs was significantly associated with recurrence (p=0.013). Genetic diversity between primary and metastatic lesions and among metastases was validated by evaluating the p53 and MMR proteins using immunohistochemistry analysis. Conclusion: The molecular characteristics of metastatic lesions in addition to those of primary lesions could provide beneficial prognostic information in patients with EC with regional LN metastasis.
This work introduces a new training program performance assessment methodology for engineering organizations that is based upon needs assessment, types of training, and training effectiveness ...measures. The methodology checks whether predefined objectives of a company are identified through a needs assessment. Effectiveness is judged on whether the types of training and coursework content are formulated to fulfill the needs assessment objectives, whether the coursework is available to the proper employees, whether the courses are attended and understood by the employees, and whether the coursework content is utilized in the work place to meet the needs assessment objectives of the company. A case study of three training programs conducted within a public sector engineering organization is included to demonstrate the methodology and evaluate both the three programs and the methodology effectiveness. Conclusions suggest improvements to future training programs for the public sector engineering organization, as well as describe potential enhancements to the effectiveness measures of the methodology that can be recognized through further study of existing training programs.
Celotno besedilo
Dostopno za:
DOBA, FGGLJ, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The magnetooptical Faraday rotation ( theta /sub F/) spectra of highly bismuth-substituted yttrium iron garnet (R/sub 3-x/Bi/sub x/ Fe/sub 5/O/sub 12/, 0<or=x<or=2.0) films prepared by the sol-gel ...method were studied in the photon energy ranging from 1.5 eV to 3.4 eV. It is shown that the enhancement of theta /sub F/ by high bismuth substitution can be explained by adding the contributions of the paramagnetic-type transitions to those of the diamagnetic-type transitions in the foregoing theory based on the charge transfer transition.< >
We have developed a new assembly method of metal enclosures in which the combined use of acrylic adhesives and rivets (fasteners) are adopted as an alternative to arc welding. We have achieved the ...following effects: (1) elimination of skill working such as welding operation and strain correction, (2) improvement of working environment by the elimination of welding operation and putty work, (3) simplification of manufacturing process and cost reduction by introducing heatless bonding method (adhesive bonding), (4) compatibility of rigidity with weight reduction of products, (5) total energy consumption decrease to 78% by adopting this new assembly method, to 64% by thinner galvanized steel and to 51% by pre-coated steel.
Weldbonding is used to improve the efficiency and strength of adhesion and to improve the effectiveness of spot welding. The weld techniques and adhesives used are described. Bonding a 1.6 t steel ...sheet with a modified acrylate was compared with weldbonding using a one or two liquid epoxy and Fe or Al spot welding with varying weld time. Shear, separation and impact strength and creep characteristics for various weldbonding techniques and environments were compared. The applications of weldbonding in aerospace, structural work, impact and automobiles are outlined. 22 ref.--M.O.
Perpendicularly magnetized films of polycrystalline bismath substituted dysprosium iron garnets (Bi xDy3-xFe5O12, x=1.0 and 1.5) were attempted to prepare by spin-on process of a gel coated on glass ...substrates. The coated gels were preannealed at temperatures Tpa=400, 500 and 600 °C for 20 minutes to evacuate water, NOx and hydrocarbon impurities contained in the gel. They were successively subject to heat treatment at temperatures Ta up to 800 °C for 4 hours to form garnet crystal. The experiment revealed that Tpa and the ramp rate to Ta govern the crystallographic nature of film. Single garnet phase films with good surface smoothness and finer grains were formed under the conditions that Tpa=400 °C and Ta=750 °C within a few minutes by employing a very high ramp rate anneal.
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