Comparing the effect of a desensitizing material and a self-etch adhesive on dentin sensitivity after periodontal surgery: a randomized clinical trial

Hajizadeh, Hila,Nemati-Karimooy, Atefeh,Majidinia, Sara,Moeintaghavi, Amir,Ghavamnasiri, Marjaneh The Korean Academy of Conservative Dentistry 2017 Restorative Dentistry & Endodontics Vol.42 No.3

Objectives: This double-blind randomized placebo-controlled clinical trial evaluated the ability of a desensitizing agent and a self-etch adhesive on cervical dentin sensitivity (CDS) after periodontal surgery. Materials and Methods: Ninety hypersensitive teeth of 13 subjects were included in the study. After periodontal surgery, the teeth of each posterior sextant treated with one of the following materials: G1: Clearfil $S^3$ Bond (Kuraray Dental), G2: Gluma Desensitizer (Heraeus Kulzer), and G3: placebo (water). The sensitivity was assessed using evaporative stimuli before treatment (baseline, T0), 1 day after treatment (T1), after 1 week (T2), and 1 month (T3) according to visual analog scale (VAS). Results: Following the treatment, all the 3 groups showed significant reduction of CDS in T1 compared to T0. Reduction of CDS between T1 and T2 was observed only in G1 but there was no significant difference between T2 and T3 in this group. Although we observed a significant difference in T3 compared to T1 and T2 in G2 and G3, comparison of treatment groups in each assessment time showed a significant difference only in T3. According to paired comparison, this was due to the difference between G2 and G3. Conclusions: Dentin sensitivity following periodontal surgery will decrease spontaneously over time, but treating the sensitive teeth with Gluma Desensitizer and Clearfil $S^3$ Bond can have some benefits.

Power Flow Control of Grid-Connected Fuel Cell Distributed Generation Systems

Hajizadeh, Amin,Golkar, Masoud Aliakbar The Korean Institute of Electrical Engineers 2008 Journal of Electrical Engineering & Technology Vol.3 No.2

This paper presents the operation of Fuel Cell Distributed Generation(FCDG) systems in distribution systems. Hence, modeling, controller design, and simulation study of a Solid Oxide Fuel Cell(SOFC) distributed generation(DG) system are investigated. The physical model of the fuel cell stack and dynamic models of power conditioning units are described. Then, suitable control architecture based on fuzzy logic and the neural network for the overall system is presented in order to activate power control and power quality improvement. A MATLAB/Simulink simulation model is developed for the SOFC DG system by combining the individual component models and the controllers designed for the power conditioning units. Simulation results are given to show the overall system performance including active power control and voltage regulation capability of the distribution system.

Effect of Two-Step Severe Plastic Deformation on the Microstructure and Mechanical Properties of Commercial Purity Titanium

Kaveh Hajizadeh,Beitallah Eghbali 대한금속·재료학회 2014 METALS AND MATERIALS International Vol.20 No.2

The present work investigates the microstructural and mechanical properties of commercial purity titaniumafter processing by a two-step severe plastic deformation procedure entailing warm equal channel angularpressing (ECAP) followed by cold rolling at liquid nitrogen temperature (LNT). The effect of subsequent coldrolling at room temperature is also investigated for comparison. After 10 passes of ECAP, an ultrafine-grainedstructure with average grain size of 213 nm was achieved. Subsequent cold rolling at LNT led to further refinementand decreased the grain size to 114 nm. Under these conditions, the material displayed high tensilestrength of 995 MPa and high elongation to failure of 23%. These promising mechanical properties were interpretedin terms of characteristics of the microstructure: grain refinement, increased dislocation density, and ahigh fraction of high angle grain boundaries.

Power Flow Control of Grid-Connected Fuel Cell Distributed Generation Systems

Amin Hajizadeh,Masoud Aliakbar Golkar 대한전기학회 2008 Journal of Electrical Engineering & Technology Vol.3 No.2

This paper presents the operation of Fuel Cell Distributed Generation (FCDG) systems in distribution systems. Hence, modeling, controller design, and simulation study of a Solid Oxide Fuel Cell (SOFC) distributed generation (DG) system are investigated. The physical model of the fuel cell stack and dynamic models of power conditioning units are described. Then, suitable control architecture based on fuzzy logic and the neural network for the overall system is presented in order to activate power control and power quality improvement. A MATLAB/Simulink simulation model is developed for the SOFC DG system by combining the individual component models and the controllers designed for the power conditioning units. Simulation results are given to show the overall system performance including active power control and voltage regulation capability of the distribution system.

Theoretical design of Zn-dithiaporphyrins as sensitizer for dye-sensitized solar cells

Fatemeh Hajizadeh,Adel Reisi-Vanani,Yavar T. Azar 한국물리학회 2018 Current Applied Physics Vol.18 No.10

We have designed zinc dithiaporphyrin structures based on donor–π-acceptor (D-π-A) strategy and studied their optoelectronic properties as sensitizer for dye sensitized solar cells (DSSC) applications. The geometries, HOMOLUMO energy gap, electronic absorption spectra and light harvesting efficiency (LHE) of these sensitizers were investigated by density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations. Our results showed that LUMO energies of all dyes are above the conduction band (CB) of TiO2 and the HOMO energies of them are below the redox couple of I−/I3 −, thus new sensitizers have convenient HOMO and LUMO energy levels for electron transfer from the excited dye to TiO2 semiconductor and dye regeneration. They also have broadened and red-shifted absorption bands. Open-circuit voltage (Voc) and the short-circuit current density (Jsc) parameters including LHE, electron injection driving force (ΔGinject) and the free energy change for dye regeneration (ΔGregen) were calculated and discussed. The excited and ground state dipole moments were also calculated and their differences ( − ΔμEX GS) were discussed. Finally, results showed that thiophene and benzothiadiazole rings in comparison with phenyl ring as π-bridge and cyanoacrylic acid relative to the carboxylic acid as acceptor and anchoring groups showed better efficiency. A general comparison of our new sensitizers with reference dyes (YD2-o-C8 and SM315) showed that new sensitizers can be used for DSSC applications.

Comparing the effect of a desensitizing material and a self-etch adhesive on dentin sensitivity after periodontal surgery: a randomized clinical trial

Hila Hajizadeh,Atefeh Nemati-Karimooy,Sara Majidinia,Amir Moeintaghavi,Marjaneh Ghavamnasiri 대한치과보존학회 2017 Restorative Dentistry & Endodontics Vol.42 No.3

Objectives: This double-blind randomized placebo-controlled clinical trial evaluated the ability of a desensitizing agent and a self-etch adhesive on cervical dentin sensitivity (CDS) after periodontal surgery. Materials and Methods: Ninety hypersensitive teeth of 13 subjects were included in the study. After periodontal surgery, the teeth of each posterior sextant treated with one of the following materials: G1: Clearfil S3 Bond (Kuraray Dental), G2: Gluma Desensitizer (Heraeus Kulzer), and G3: placebo (water). The sensitivity was assessed using evaporative stimuli before treatment (baseline, T0), 1 day after treatment (T1), after 1 week (T2), and 1 month (T3) according to visual analog scale (VAS). Results: Following the treatment, all the 3 groups showed significant reduction of CDS in T1 compared to T0. Reduction of CDS between T1 and T2 was observed only in G1 but there was no significant difference between T2 and T3 in this group. Although we observed a significant difference in T3 compared to T1 and T2 in G2 and G3, comparison of treatment groups in each assessment time showed a significant difference only in T3. According to paired comparison, this was due to the difference between G2 and G3. Conclusions: Dentin sensitivity following periodontal surgery will decrease spontaneously over time, but treating the sensitive teeth with Gluma Desensitizer and Clearfil S3 Bond can have some benefits.

Crotonaldehyde removal from polluted air using a biofilter packed with a mixed bed

Yaghoub Hajizadeh,Mohammad Mehdi Amin,Iman Parseh 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.62 No.-

This study investigated the performance of a biofilter to remove crotonaldehyde from air. Total average of removal efficiency (RE) and elimination capacity (EC) were 88% and 0.73 g m−3 h−1, respectively. Nearly 57% of the RE was occurred in the first 20 cm of the biofilter, where the bacterial population (7.42 log10CFU g−1) and fungi population (5.25 log10CFU g−1) were significantly more than the other sections. Predominant species of bacteria in the biofilter bed were Pseudomonas, Acinetobacter, and Proteus spp. Finally, it can be inferable that the biofilter can be a suitable method to remove crotonaldehyde from air.

Modified Atmosphere Packaging (MAP) Effects on Quality Maintenance and Storage Life Extension of Local Iranian Apple “Golab Kohanz”

Hanife S. Hajizadeh,Younes Mostofi,Ali reza Talaie 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

Performance evaluation of wavelet and curvelet transforms based-damage detection of defect types in plate structures

Ali R. Hajizadeh,Javad Salajegheh,Eysa Salajegheh 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.60 No.4

This study focuses on the damage detection of defect types in plate structures based on wavelet transform (WT) and curvelet transform (CT). In particular, for damage detection of structures these transforms have been developed since the last few years. In recent years, the CT approach has been also introduced in an attempt to overcome inherent limitations of traditional multi-scale representations such as wavelets. In this study, the performance of CT is compared with WT in order to demonstrate the capability of WT and CT in detection of defect types in plate structures. To achieve this purpose, the damage detection of defect types through defect shape in rectangular plate is investigated. By using the first mode shape of plate structure and the distribution of the coefficients of the transforms, the damage existence, the defect location and the approximate shape of defect are detected. Moreover, the accuracy and performance generality of the transforms are verified through using experimental modal data of a plate.

Determination of a Change Point in the Age at Diagnosis of Breast Cancer Using a Survival Model

Abdollahi, Mahbubeh,Hajizadeh, Ebrahim,Baghestani, Ahmad Reza,Haghighat, Shahpar Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.no.sup3

Breast cancer, the second cause of cancer-related death after lung cancer and the most common cancer in women after skin cancer, is curable if detected in early stages of clinical presentation. Knowledge as to any age cut-off points which might have significance for prognostic groups is important in screening and treatment planning. Therefore, determining a change-point could improve resource allocation. This study aimed to determine if a change point for survival might exist in the age of breast cancer diagnosis. This study included 568 cases of breast cancer that were registered in Breast Cancer Research Center, Tehran, Iran, during the period 1986-2006 and were followed up to 2012. In the presence of curable cases of breast cancer, a change point in the age of breast cancer diagnosis was estimated using a mixture survival cure model. The data were analyzed using SPSS (versions 20) and R (version 2.15.0) software. The results revealed that a change point in the age of breast cancer diagnosis was at 50 years age. Based on our estimation, 35% of the patients diagnosed with breast cancer at age less than or equal to 50 years of age were cured while the figure was 57% for those diagnosed after 50 years of age. Those in the older age group had better survival compared to their younger counterparts during 12 years of follow up. Our results suggest that it is better to estimate change points in age for cancers which are curable in early stages using survival cure models, and that the cure rate would increase with timely screening for breast cancer.