CONSTRUCTION OF ORDERED REGULAR EQUIVALENCE RELATIONS ON ORDERED SEMIHYPERRINGS

Omidi, Saber,Davvaz, Bijan The Honam Mathematical Society 2018 호남수학학술지 Vol.40 No.4

In the present paper, we construct an ordered regular equivalence relation on an ordered semihyperring by 2-hyperideals such that the corresponding quotient structure is also an ordered semihyperring.

The effect of embryo catheter loading technique on the live birth rate

Omidi, Marjan,Halvaei, Iman,Mangoli, Esmat,Khalili, Mohammad Ali,Razi, Mohammad Hossein The Korean Society for Reproductive Medicine 2015 Clinical and Experimental Reproductive Medicine Vol.42 No.4

Objective: Embryo loading (EL) is a major step in embryo transfer (ET) and affect on the success of in vitro fertilization (IVF). This study aimed to compare the effect of two different EL techniques on the rates of pregnancy and delivery in IVF/ET cycles. Methods: 207 fresh ET and 194 Frozen-thawed ET (FET) cycles were included in this retrospective study. Two groups (A and B) were defined based on the EL technique used. In group A, the entire catheter was flushed with Ham's F-10 medium. The embryos were then drawn into the catheter using one air bracket. In group B, $70{\mu}L$ of air was aspirated into the syringe and the catheter was flushed using Ham's F10 medium. The medium, air, embryos, air, and finally another layer of medium were then sequentially drawn into the catheter. The main outcome measures were the pregnancy and delivery rates. Results: The groups did not differ with respect to the etiology of infertility, the source of spermatozoa, the quality of the embryos, the type of EL catheter, and the ease of transfer. The pregnancy rate was similar between two groups. In fresh ET cycles, a higher delivery rate was observed in group B than it group A (78.1% vs. 60%, p=0.1). In FET cycles, the rate of delivery was significantly higher in group B than in group A to a nonsignificant extent (88.9% vs. 58.8%, p=0.06). Conclusion: EL techniques did not have a significant impact on the delivery rate in either fresh or FET cycles.

STUDY ON CLEAN ORDERED RINGS DERIVED FROM CLEAN ORDERED KRASNER HYPERRINGS

Saber Omidi,Bijan Davvaz 한국수학교육학회 2018 純粹 및 應用數學 Vol.25 No.2

In this paper, we introduce the notion of a clean ordered Krasner hy-perring and investigate some properties of it. Now, let (R;+,;≤) be a clean ordered Krasner hyperring. The following is a natural question to ask: Is there a strongly regular relation σ on R for which R/σ is a clean ordered ring? Our motivation to write the present paper is reply to the above question.

Comparison of Functional Outcomes following Surgical Decompression and Posterolateral Instrumented Fusion in Single Level Low Grade Lumbar Degenerative versus Isthmic Spondylolisthesis

Farzad Omidi-Kashani,Ebrahim Ghayem Hasankhani,Mohammad Dawood Rahimi,Reza Khanzadeh 대한정형외과학회 2014 Clinics in Orthopedic Surgery Vol.6 No.2

Background: The two most common types of surgically treated lumbar spondylolisthesis in adults include the degenerative and isthmic types. The aim of this study was to compare the functional outcomes of surgical decompression and posterolateral instrumented fusion in patients with lumbar degenerative and isthmic spondylolisthesis. Methods: In this retrospective study, we reviewed the clinical outcomes in surgically treated patients with single level, low grade lumbar degenerative, and isthmic spondylolisthesis (groups A and B, respectively) from August 2007 to April 2011. We tried to compare paired settings with similar initial conditions. Group A included 52 patients with a mean age of 49.2 ± 6.1 years, and group B included 52 patients with a mean age of 47.3 ± 7.4 years. Minimum follow-up was 24 months. The surgical procedure comprised neural decompression and posterolateral instrumented fusion. Pain and disability were assessed by a visual analog scale (VAS) and the Oswestry Disability Index (ODI), respectively. The Wilcoxon and Mann-Whitney U-tests were used to compare indices. Results: The most common sites for degenerative and isthmic spondylolisthesis were at the L4–L5 (88.5%) and L5–S1 (84.6%) levels, respectively. Surgery in both groups significantly improved VAS and ODI scores. The efficacy of surgery based on subjective satisfaction rate and pain and disability improvement was similar in the degenerative and isthmic groups. Notable complications were also comparable in both groups. Conclusions: Neural decompression and posterolateral instrumented fusion significantly improved pain and disability in patients with degenerative and isthmic spondylolisthesis. The efficacy of surgery for overall subjective satisfaction rate and pain and disability improvement was similar in both groups.

Radiologic and Clinical Outcomes of Surgery in High Grade Spondylolisthesis Treated with Temporary Distraction Rod

Farzad Omidi-Kashani,Alireza Hootkani,Lida Jarahi,Manizheh Rezvan,Amir Moayedpour 대한정형외과학회 2015 Clinics in Orthopedic Surgery Vol.7 No.1

Background: Surgical techniques used in the treatment of patients with high grade lumbar spondylolisthesis (> 50% slippage) areusually associated with a great deal of controversies. We aim to evaluate the surgical outcomes of high grade spondylolisthesistreated with an intraoperative temporary distraction rod. Methods: We retrospectively studied 21 patients (14 females and 7 males), aged 50.4 ± 9.2 years, who had high grade lumbarspondylolisthesis that was treated with intraoperative temporary distraction rods, neural decompression, pedicular screw fixation,and posterolateral fusion involving one more intact upper vertebra. The mean follow-up period was 39.2 months. Radiologic andclinical outcomes were measured by slip angle, slip percentage, correction rate, Oswestry Disability Index (ODI), visual analoguescale (VAS), patient’s satisfaction rate in the pre- and postoperative period. Data were analyzed by SPSS ver. 11.5. Results: Analysis of the preoperative visits and final follow-up visits indicated that surgery could improve ODI, lumbar VAS, andleg VAS from 60.5% to 8.2%, from 6.7 to 2.2, and from 6.9 to 1.3, respectively. Slip angle and slip percentage were also changedfrom –8° to –15° and from 59.2% to 21.4%, respectively. Mean correction rate at the final follow-up visit was 64.1%. Loss of correctionwas insignificant and a neurologic complication occurred in one patient due to misplacement of one screw. Excellent andgood levels of satisfaction were observed in 90.5% of the patients. Conclusions: In the surgical treatment of refractory high grade spondylolisthesis, the use of a temporary distraction rod to reducethe slipped vertebra in combination with neural decompression, posterolateral fusion, and longer instrumentation is associatedwith satisfactory clinical and radiologic outcomes.

Identifying Requirements of Agricultural Mobile Marketing from Experts’ Perception

Maryam Omidi Najafabadi,Mahmood Ahmadi,Farhad Lashgarara 보안공학연구지원센터(IJUNESST) 2014 International Journal of u- and e- Service, Scienc Vol.7 No.1

3-D fracture analysis of cracked aluminum plates repaired with single and double composite patches using XFEM

Jamal-Omidi, Majid,Falah, Mehdi,Taherifar, Davood Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.50 No.4

Bonded composite-patch repair has been widely used to restore or extend the service life of damaged structures due to its effectiveness as a mechanical repair technique. In this paper using extended finite element method (XFEM), three-dimensional crack models are developed to examine the fracture behavior of centrally cracked aluminum plates repaired with single and double sided composite patches. Stress intensity factor (SIF) at the crack tip is used as the fracture criterion. In this regard, the effects of the crack lengths, patch materials, orientation of plies, adhesive and patch thickness are examined to estimate the SIF of the repaired plate and the repair performance. The obtained results show that composite patches have significant effect on reduction of the SIF at the crack tip. It is also proved that using double symmetric repair, in comparison to single one, reduces considerably SIF at the crack tip. Hence, the residual strength can be improved significantly as well as fatigue life of the structure. Investigation of ply orientation effects shows SIF increase as the ply orientation is changed from $0^{\circ}$ (perpendicular to the advancing crack) to $90^{\circ}$ (parallel to the crack line). However, the effectiveness of the ply orientation depends on the loading direction and the crack direction.

Investigating on performance parameters and flow field of centrifugal compressor based on the splitter blade leading edge's location effect

Mohammad Omidi,Yan Liu,Soheil Mohtaram,Shuai Li 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.8

Impeller design in turbomachines is one of the most challenging issues in these machines' systems, which still plays a significant role in their efficiency and performance. This article considers different designs for splitter blades. Therefore, the CFD methods modify the position of the splitter blades leading edge at the hub and shroud. This modification shall lead to a different splitter blade profile from the main blades. Then, the effects of splitter blades are discussed, and the performance parameters have also been studied to improve this method's implementation. The results revealed that the compressor's efficiency was improved by approximately 1.5 % in one specific case. This finding proves that the previous design methods were not the optimum ones for compressors and how to increase the compressor's efficiency by CFD methods and by changing the splitter blades' location.

Failure Rate of Spine Surgeons in Preoperative Clinical Screening of Severe Psychological Disorders

Farzad Omidi-Kashani,Farhad Faridhoseini,Shahrara Ariamanesh,Mahya Hashemi Kazar,Aslan Baradaran 대한정형외과학회 2016 Clinics in Orthopedic Surgery Vol.8 No.2

Background: The surgeon’s attention to the patient’s underlying psychological state is essential to attaining desired outcomes. We aimed to investigate the prevalence and severity of psychological disorders in patients undergoing elective spine surgery. Methods: In this case-control study, associated psychological disorders were assessed using the Hospital Anxiety and Depression Scale (HADS) questionnaire at a single academic spine surgery center from August 2013 to June 2015. The case group consisted of 68 adult patients (mean age, 38.2 ± 9.6 years; male:female = 41:27) undergoing elective spine surgery and the control group included 69 healthy visitors of the orthopedic patients (mean age, 37.1 ± 6.9 years; male:female = 40:29) who voluntarily participated in the study. The 2 groups were compared for statistical analysis and a p-value < 5% was considered significance. Results: There was no statistically significant intergroup difference with regard to gender and age. The incidences of abnormal anxiety and depression were the same in the case group (14 patients, 20.6%). The values were 3 (4.3%) and 5 (7.2%), respectively, in the control group, showing statistically significant difference. Any association between the severity of depression and age or sex could not be identified. Conclusions: In spite of spine surgeons’ attempts to screen severe psychological disorders preoperatively, up to 21% of which cannot be diagnosed prior to elective spine surgery. Therefore, we believe the use of a questionnaire would be helpful in assessing patients’ underlying psychological state before elective spine surgery.

Lumbar Spinal Stenosis: Who Should Be Fused? An Updated Review

Farzad Omidi Kashani,Ebrahim Ghayem Hasankhani,Amir Ashjazadeh 대한척추외과학회 2014 Asian Spine Journal Vol.8 No.4

Lumbar spinal stenosis (LSS) is mostly caused by osteoarthritis (spondylosis). Clinically, the symptoms of patients with LSS can be categorized into two groups; regional (low back pain, stiffness, and so on) or radicular (spinal stenosis mainly presenting as neurogenic claudication). Both of these symptoms usually improve with appropriate conservative treatment, but in refractory cases, surgical intervention is occasionally indicated. In the patients who primarily complain of radiculopathy with an underlying biomechanically stable spine, a decompression surgery alone using a less invasive technique may be sufficient. Preoperatively, with the presence of indicators such as failed back surgery syndrome (revision surgery), degenerative instability, considerable essential deformity, symptomatic spondylolysis, refractory degenerative disc disease, and adjacent segment disease, lumbar fusion is probably recommended. Intraoperatively, in cases with extensive decompression associated with a wide disc space or insufficient bone stock, fusion is preferred. Instrumentation improves the fusion rate, but it is not necessarily associated with improved recovery rate and better functional outcome.