| 1. |
- Najafi-Ghezeljeh, T., et al.
(författare)
-
The Iranian version of Angina Pectoris characteristics questionnaire: reliability assessment
- 2009
-
Ingår i: J Clin Nurs. - 1365-2702. ; 18:5, s. 694-9
-
Tidskriftsartikel (refereegranskat)abstract
- AIMS: To evaluate internal consistency and test-retest reliability of the Iranian version of the Angina Pectoris characteristics questionnaire. BACKGROUND: To evaluate symptoms in patients with Angina Pectoris, the Iranian version of the Angina Pectoris characteristics questionnaire was created by combining items from Modified Rose Questionnaire, Short Form-McGill Questionnaire and the Accompanying Symptom Checklist. The Angina Pectoris characteristics questionnaire has been developed and validated recently although it required assessment of its reliability. DESIGN: Reliability study using test and retest. METHOD: One hundred and ten coronary heart disease patients with Angina Pectoris were included. The test-retest reliability of the instrument was estimated for measurement after 15 days. RESULT: The analysis of the result indicated that internal consistency was found adequate at both assessments (Cronbach's alpha = 0.65) for test and retest. There was no significant difference between test and retest. The intra-class correlation coefficient ranged from 0.76-0.98. CONCLUSION: The Angina Pectoris characteristics questionnaire is a reliable instrument for the assessment of Angina Pectoris characteristics in a Persian population. RELEVANCE TO CLINICAL PRACTICE: The Angina Pectoris characteristics questionnaire can be used with confidence in Iranian coronary heart disease patients for Assessing Angina Pectoris symptom.
|
|
| 2. |
|
|
| 3. |
- Emami, Nazanin, et al.
(författare)
-
Dynamic mechanical thermal analysis of two light-cured dental composites
- 2005
-
Ingår i: Dental Materials. - : Elsevier BV. - 0109-5641 .- 1879-0097. ; 21:10, s. 977-983
-
Tidskriftsartikel (refereegranskat)abstract
- ObjectivesClinical observations suggest that some composite resins are more often linked to post-operative sensitivity than others. These differences may relate to differences in modulus of elasticity and polymerization rates among materials. The aim of this study was to identify viscoelastic behavior of two light curable composites and determine whether significant differences in viscoelastic behavior exist between the two materials when light cured at each of three different irradiance values.MethodsTwo composites (Z100 and Z250 by 3M ESPE) were evaluated. Six specimens per composite and irradiance value (250, 500 and 850 mW/cm2) were made. The curing times were chosen to produce a fixed energy value of 30 J/cm2 independent of irradiation value. Dynamic mechanical thermal analysis (DMTA) was performed in single cantilever clamped mode.ResultsThere were significant differences in transition temperatures between the two materials and the three frequencies at their glass transition temperatures, while significant differences did not exist at the lower transitions. The glass transition of Z250 was lower and narrower than that of Z100. Z250 exhibited lower storage modulus values. The irradiance values did not affect any of the transition temperatures significantly.SignificanceThe lower and more distinct Tg of Z250 suggests that Z250 cures more efficiently than Z100. The lower storage modulus of Z250 suggests that Z250 develops less stress in the tooth than Z100 during curing if shrinkage is the same for the two materials. The findings suggest that the material chosen, rather than irradiance, determines the stress level developed during light curing.
|
|
| 4. |
- Emami, Nazanin, et al.
(författare)
-
How degree of conversion and E-modulus of light-cure dental-resins interact
- 2006
-
Ingår i: 84th General Session and Exhibition of the IADR and 1st Meeting of the Pan-Asian-Pacific Federation. - : IADR.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Objectives: To investigate how E-modulus, degree of conversion (DC%) and rate of polymerization of the most used monomer resins in dental light-cure composites interact. Methods: Young's modulus and DC% were studied for 21 different resin combinations of three commonly used dental monomers, bis-GMA, TEGDMA and UEDMA (combinations of 0, 20, 40, 60 and 100 wt% as it is illustrated in the figure). For each resin combination 6 specimens were tested. Small Instron and differential scanning calorimetry (photo-calorimetry) were used as testing machines. The results were tested using ANOVA and Duncan's multiple range tests and regular t-test. Results: Rate of polymerization was significantly (p<0.05) higher when the wt% of the TEGDMA was high in the mixtures compare to highly concentrated bis-GMA. DC% was significantly high (p<0.05) for binary mixture of UEDMA and TEGDMA. The DC% was significantly lower for 100 wt% bis-GMA (p<0.05). The calculated values for DC% were between 53.1%± 0.9% and 85.6%±1%. Young's modulus values varied between 2.37± 0.15 GPa and 4.15± 0.2 GPa. It was noticeable that by adding TEGDMA to bisGMA or UEDMA, the Young's modulus decreased significantly (p<0.05). There were no significant (p>0.05) differences between Young's modulus values when the monomer mixtures contained bis-GMA, TEGDMA and UEDMA at different concentration levels. The higher the concentration of bisGMA in the monomer mixture, the lower was the degree of conversion. However, Young's modulus increased at higher concentration of bis-GMA. Conclusions: The differences in the values for degree of conversion were mostly justified by the differences in the molecular structures of the different monomers. It was also revealed that higher degree of conversion does not always result in a higher Young's modulus, because molecular and network structural parameters play major roles in the final mechanical/physical properties of the mixtures.
|
|
| 5. |
- Emami, Nazanin, et al.
(författare)
-
How filler properties, filler fraction, sample thickness and light source affect light attenuation in particulate filled resin composites
- 2005
-
Ingår i: Dental Materials. - : Elsevier BV. - 0109-5641 .- 1879-0097. ; 21:8, s. 721-730
-
Tidskriftsartikel (refereegranskat)abstract
- The way by which variables such as filler type, filler surface treatment and light source affect light attenuation in particulate filled resin composites was presented. Mixture of 50 wt% bisGMA and 50wt% TEGDMA consisting of a photo-initiatior and a co-initiator was prepared. Three different filler types, HBB, SBB, and KU, which were either silane surface treated or not, were added to that mixture in eight different volume percentage. It was observed that of the two light sources, more light was absorbed by the composite when the laser light was used. It was also observed that the HBB filler absorbed most light and the KU filler the least.
|
|
| 6. |
- Emami, Nazanin, et al.
(författare)
-
Influence of light-curing procedures and photo-initiator/co-initiator composition on the degree of conversion of light-curing resins
- 2005
-
Ingår i: Journal of materials science. Materials in medicine. - : Springer Science and Business Media LLC. - 0957-4530 .- 1573-4838. ; 16:1, s. 47-52
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: The hypothesis that the degree and rate of conversion can be modified favourably by using different light-curing procedures and different photo initiator/co-initiator combinations was tested.Method: A photo-initiator (0.02 mM/g resin); either camphorquinone (CQ) or 1-phenyl-1,2-propanedione (PPD), was mixed with bisGMA:TEGDMA (50:50 by weight). In addition, a co-initiator (0.04 mM/g resin); either N,N-dimethyl-p-aminobenzoic acid ethylester (DABE), N,N-cyanoethylmethylaniline (CEMA), or 2-dimethylaminoethyl methacrylate (DMAEMA), was added. These six combinations were subjected to three curing conditions (standard curing, soft-start curing or LED curing). The conversion levels (DC) were determined with differential scanning calorimetry (DSC). The DSC results were analysed using a general linear model (GLM) and Duncans multiple range test and regular t-test.Results: The fastest conversion initially was obtained by standard curing, followed by LED curing and soft-start curing. After 40 s of curing, conventional curing and soft-start curing produced a higher DC than LED curing. However, strong interactions occurred between the different variables (curing method, initiator and co-initiator). Initially, CQ was more efficient than PPD, but after 40 s, this difference was insignificant.Conclusion: By using soft-start curing and an appropriate photo initiator/co-initiator combination it is possible to achieve slow curing and a high DC at within a curing time of 40 s.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Helander, Michael G., et al.
(författare)
-
The effects of computer interface on learning outcomes in remote access laboratories
- 2009
-
Ingår i: ASEE Annual Conference and Exposition, Austin, USA, 14-17 June 2009.
-
Konferensbidrag (refereegranskat)abstract
- Remote access laboratories are increasingly being integrated into undergraduate engineering curricula on a global scale. Despite the vast body of literature dealing with remotely-accessible laboratories, the majority of papers have focused on the technical merits of a particular implementation, rather than on the implications of remote access experimentation on engineering pedagogy. Recently, a few studies have attempted to quantify the effects of the remote access modality on students' learning outcomes. These initial pedagogical studies have indicated that there is indeed a difference between proximal and remote experimentation in terms of learning outcomes. However, the question still unanswered is if these observed differences are a result of the physical separation between student and hardware, or rather are a result of the computermediated interface used to control the remote hardware. This paper discusses the results of a comprehensive study comparing the pedagogical effects of remote vs. proximal experimentation that includes control over the effects of the computer-mediated interface. Two groups of students performed the same experiment proximally and remotely using the same computer interface, and the learning outcomes are examined. © American Society for Engineering Education, 2009.
|
|
| 10. |
|
|
