Reza Taheri | Istanbul Technical University (original) (raw)

Papers by Reza Taheri

Beykent Üniversitesi, 2024

Yönetim Ekonomisi Teori ve Uygulama Prof. Dr. Cevat GERNİ

World Neurosurgery, 2021

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Journal of Tax Research, 2020

The impact of oil price on social, economic, political and many other aspects of human life is qu... more The impact of oil price on social, economic, political and many other aspects of human life is quite strong and evident. However, the role playing factors affecting the price are so complex that the price prediction cannot be solely attributed to the simple well known demand-supply relationship. This paper emphasizes on midterm prediction approach rather than short or long term ones, in which a model has been proposed based on a developed algorithm. Prediction of the prices in seasonal or annual basis was performed with highly satisfactory results. Gold and USDX were employed to verify the applicability of the proposed model.

Middle East Journal of Cancer, 2016

Background: Clinically frank thyroid nodules are common and believed to be present in 4% to 10% o... more Background: Clinically frank thyroid nodules are common and believed to be present in 4% to 10% of the adult population in the United States. In the current literature, fine needle aspiration biopsies are considered to be the milestone of a model which helps the physician decide whether a certain thyroid nodule needs a surgical approach or not. A considerable fact is that sensitivity and specificity of the fine needle aspiration varies significantly as it remains highly dependent on the operator as well as the cytologist’s skills. Practically, in the above group of patients, thyroid lobectomy/isthmusectomy becomes mandatory for attaining a definitive diagnosis where the majority (70%-80%) have a benign surgical pathology. The scattered nature of clinically gathered data and analysis of their relevant variables need a compliant statistical method. The artificial neural network is a branch of artificial intelligence. We have hypothesized that conduction of an artificial neural network...

Progress in Biological Sciences, 2013

Microalgal growth curve, after the exponential phase, shows a stationary phase where algalbiomass... more Microalgal growth curve, after the exponential phase, shows a stationary phase where algalbiomass production is inhibited and remains constant by some factors such as nutrientdepletion and intrinsic behavior. The present study is concerned with evaluating effects ofthe culture medium condition and intrinsic behavior on biomass production by Dunaliellatertiolecta. To this end, effect of pH, nutrient concentration, CO2 (NaHCO3) concentration,possible secreted substances, and cell density on the biomass production by D. tertiolectawere investigated. The results showed that biomass yield can be significantly affected by pH(p<0.01) and nutrient (p<0.05). In a combination of pH and nutrient, the biomass was found tobe more influenced by the pH, compared with the nutrients. The results showed a significantinteraction between nutrient and NaHCO3 (p<0.05), suggesting that CO2 concentration maylimit biomass production only when sufficient nutrients are available. Nutrients concentrat...

Let R be a commutative ring with identity and A(R) be the set of ideals of R with non-zero annihi... more Let R be a commutative ring with identity and A(R) be the set of ideals of R with non-zero annihilators. In this paper, we first introduce and investigate the principal ideal subgraph of the annihilating-ideal graph of R, denoted by AGP (R). It is a (undirected) graph with vertices AP (R) = A(R) ∩ P(R) \ {(0)}, where P(R) is the set of proper principal ideals of R and two distinct vertices I and J are adjacent if and only if IJ = (0). Then, we study some basic properties of AGP (R). For instance, we characterize rings for which AGP (R) is finite graph, complete graph, bipartite graph or star graph. Also, we study diameter and girth of AGP (R). Finally, we compare the principal ideal subgraph AGP (R) and spectrum subgraph AGs(R).

INTRODUCTION Leadership has long been suggested as an attribute essential to the pharmacy profess... more INTRODUCTION Leadership has long been suggested as an attribute essential to the pharmacy profession. Academic pharmacy has identified and addressed the need for leadership development among student pharmacists. The objective of this study is to assess differences in learning styles, critical thinking skills, and peer-perceived leadership skill evaluations between those with vs. without student leadership engagement (SLE). METHODS Four cohorts of pharmacy students were included in the analysis. Each student completed the Kolb Learning Style Inventory and Health Science Reasoning Test (HSRT) during pharmacy school orientation. Student-peer evaluation scores were derived from three courses and assessed important leadership skills such as communication, critical thinking, teamwork, and professionalism. Descriptive analysis was performed; group difference was tested using independent group t-tests on continuous variables and Fisher exact tests on categorical variables. RESULTS This stud...

Purpose: Medulloblastoma is the most common pediatric malignancy. Postoperative respiratory failu... more Purpose: Medulloblastoma is the most common pediatric malignancy. Postoperative respiratory failure is an important complication in post-operative recovery of patients undergoing medulloblastoma resection. We aimed to identify factors predicting tracheostomy requirement in children post-operatively.Methods: Retrospective chart review of all patients under 18 undergoing medulloblastoma resection from 2012 to 2020 at Namazi hospital was conducted.Results: 45 patients (26%) needed tracheostomy after the operation. The most common indications were brainstem compression and absence of gag reflex prior to operation. Patients who had brainstem compression and infiltration by medulloblastoma, bilateral absence of gag reflex prior to operation, subtotal resection of tumor, and post-operative brainstem contusion were more likely to require tracheostomy. No statistically significant difference was observed between males and females and different ages. Conclusion: The results show that if we pr...

Journal of Colloid and Interface Science, 2021

HYPOTHESIS CO2 geo-storage is a technique, where millions of tonnes of CO2 are stored in undergro... more HYPOTHESIS CO2 geo-storage is a technique, where millions of tonnes of CO2 are stored in underground formations every year for permanent immobilization to reduce greenhouse gas emissions. Among promising geo-storage formations, basalt is attracting keen interest from researchers and industry. However, the literature severely lacks information on the wetting behaviour of basaltic rocks at geo-storage conditions. EXPERIMENTS To enable a more general statement of basalt-scCO2-brine contact angles, the wettability of a basalt from Western Australia was compared with a similar rock type from Iceland. This study reports the advancing and receding contact angles for a basalt-scCO2-brine system at pressures ranging from 0.1 to 20 MPa and temperatures of 298 and 323 K, respectively. Based on the experimental data, the amount of CO2, expressed by the column height, which could be safely trapped beneath the basalt was then calculated. FINDINGS The basalt was initially water-wet but with increasing pressure, it was converted sequentially from a water-wet to an intermediate-wet and then finally into a completely CO2-wet template at pressures exceeding 15 MPa and 323 K. Under those experimental conditions, found in the field at depths below 1500 m, injected supercritical CO2 into a porous basalt reservoir is assumed to flow freely in lateral and vertical directions and is less impeded by capillary/residual trapping, potentially leading to CO2 leakage. It is suggested that the injection depth should not be chosen too deep to avoid increased free CO2 plume mobility. It is found from CO2 column height calculations that at 800 m depth (a minimum requirement to keep CO2 supercritical), the height of the CO2 column that can be safely trapped below the cap rock, was still 100 m but shrank to nil at ≥1500 m.

Biomedical Research, 2018

Background: Vascular grafts are used common in surgery. Some patients have no native vessels for ... more Background: Vascular grafts are used common in surgery. Some patients have no native vessels for autograft so we should use vascular graft. In this study we assessed tissue reaction of rats to materials used in vascular grafts. Materials and methods: We prepared 8 types of grafts with electro-spinning method from different materials such as polycaprolactone (PCL), polyurethane (PU) and polyethylene terephthalate (PET) in sporadic and mixture patterns. After sterilisation with ethylene oxide, grafts were implanted in subcutaneous layer of 32 rats (divided into 8 groups of 4 rats). Rats assessed for local and general responses in 45 d. Histopathological responses were assessed by pathologist after 45 d. Results: There is no mortality during study. There are no local and systemic responses. Surgical site Infection not found. Tissue reactions to polyethylene terephthalate (PET) was higher than PET (Bio). Tissue reactions to polyurethane (PU) and PU (Bio) were about equal. PU had lower reactions in comparison with (PET) and polycaprolactone (PCL). PU+PET (Bio) had lower reaction in comparison with PET+PCL (Bio) Conclusions: It seems polyurethane has lesser reaction in compared with other materials in both single and mixture

Journal of Clinical Oncology, 2017

6078 Background: The standard of care for OPSCC includes chemoradiation (CRT) or surgery with adj... more 6078 Background: The standard of care for OPSCC includes chemoradiation (CRT) or surgery with adjuvant radiation (RT). However, RT is associated with significant life long morbidity. We assessed the efficacy of a two-drug induction regimen, followed by transoral robotic assisted surgery (TORS) & neck dissection for locally advanced OPSCC. Methods: This is an IRB approved single-arm phase II study for untreated stage III or IVA OPSCC patients (pts) with an ECOG < 2 and GFR > 50 cc. Induction chemotherapy consisted of cisplatin 75 mg/m2 and taxotere 75 mg/m2 every 21 days for 3 cycles. Tumor shrinkage was examined after each cycle. If the primary tumor was > 80% smaller, pts underwent TORS and neck dissection(s). At post-op visits, flexible laryngoscopy, blood work, and imaging with PET/CT and/or MRI were done. Short and long term toxicity, progression-free survival (PFS) and overall survival (OS), and quality of life (QOL) were evaluated. Results: Nineteenpts were treated an...

International Journal of Cancer Management, 2019

Background: Stress hyperglycemia during surgeries has been reported to increase the possibility o... more Background: Stress hyperglycemia during surgeries has been reported to increase the possibility of surgical site infections (SSIs) and worsen the patient's prognosis. Objectives: The aim of the present study was to evaluate the correlation between perioperative blood sugar level and SSIs in patients undergoing mastectomy. Methods: In this prospective case-control study, 158 female patients undergoing mastectomy were included with diabetes as an exclusion criterion. Blood glucose levels were measured in 5 phases for each patient. Results: Among 158 studied patients, 8 (5.5%) developed SSIs. Four patients (2.74%) in the control group and 4 patients (50%) in the case group had hyperglycemia in at least one of the stages. Logistic regression analysis demonstrated associations between SSI development and any blood glucose value of more than 150 mg/dL. It seems that age, medical history, current smoking, tumor characteristics, previous chemoradiotherapy, surgical duration, administration of prophylactic antibiotics, and other surgical factors have not been significantly correlated with SSI. Conclusions: As hyperglycemia is an easily controllable factor, the control of blood sugar levels during the perioperative period is recommended in patients undergoing breast surgeries to decrease SSI rates.

Lubricants, 2018

Vegetable oil-in-water (VO/W) emulsions are bio-based metal working lubricants. The emulsions' lu... more Vegetable oil-in-water (VO/W) emulsions are bio-based metal working lubricants. The emulsions' lubrication performance depends on the stability of oil droplets. In this paper, the oil droplets' dispersion stability and lubrication of emulsions containing TiO 2 /SiO 2 nanoparticles (NPs) as dispersant and lubrication agents have been investigated. Enhanced dispersion of NP-shielded oil droplets was found. Increasing the NPs' mass fraction initially lowers the average size of NP-shielded droplets up to the saturation of the droplets' surface with NPs at 0.5 wt % mass fraction. NPs also form NP agglomerates in emulsions, more so after the droplets' surfaces have been saturated with NPs. There is an apparent minimum quantity of NPs (~0.5 wt %) required to ensure sustained dispersions of the droplets which is thought to be related to the oil concentration and the droplets' total surface-area-to-volume ratio. Below the required quantity of NPs, partially shielded and fully shielded droplets coexist. The partially shielded droplets initially attract other droplets and undergo limited coalescence but retain their long-term stability. A small quantity of NPs improves the antiwear property of the lubricants. However, emulsions with NPs have slightly higher friction than the NP-free emulsion due to the reduced strength of the tribofilm. Despite the increased friction, the tribofilm formed in presence of NPs can easily be removed from the surface with water, indicating cleaner surfaces after the lubrication (i.e., less oil residue on the surfaces), which, for the sake of cleanliness, is favourable in many applications.

American journal of pharmaceutical education, 2018

The topic of adapting one's leadership style is controversial and can generate great debate. ... more The topic of adapting one's leadership style is controversial and can generate great debate. When one considers adapting one's leadership style, the question of authenticity often bubbles to the surface. This is even more compelling in the context of generational differences in our society and workforce. How can faculty members be effective if they refuse to adapt their leadership style to students' learning styles and generational characteristics? Leadership development is an ongoing focus for the American Association of Colleges of Pharmacy (AACP) to prepare faculty for roles as future leaders in higher education while a major redistribution of generations is occurring within the workforce. These generations are molded by many factors, including the economy, significant events, technology, and education. As experienced leaders, we affirm that one's leadership styles must be honed over time and adapted to reflect generational differences in academic pharmacy among c...

The Permanente journal, 2018

Web-based learning (WBL) modules are effectively used to improve medical education curriculum; ho... more Web-based learning (WBL) modules are effectively used to improve medical education curriculum; however, they have not been evaluated to improve head computed tomography (CT) scan interpretation in an emergency medicine (EM) setting. To evaluate the effectiveness of a WBL module to aid identification of cranial structures on CT and to improve ability to distinguish between normal and abnormal findings. Prospective, before-and-after trial in the Emergency Department of an academic center. Baseline head CT knowledge was assessed via a standardized test containing ten head CT scans, including normal scans and those showing hemorrhagic stroke, trauma, and infection (abscess). All trainees then participated in a WBL intervention. Three weeks later, they were given the same ten CT scans to evaluate in a standardized posttest. Improvement in test scores. A total of 131 EM clerkship students and 32 EM residents were enrolled. Pretest scores correlated with stage of training, with students an...