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Sensitivity and inter-observer variability for capsule endoscopy image analysis in a cohort of novice readers

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World Journal of Gastroenterology 2006年第8期12卷 1249-1254页

作者： Gary C Chen pedram Enayati Tam Tran Mary Lee-Henderson Clifford Quan Gareth Dulai Ian Arnott James Sul Rome Jutabha UCLA Center for Small Bowel Diseases UCLA Medical CenterLos AngelesCAUnited States Cedars-Sinai Medical CenterLos AngelesCAUnited States UCLA Center for Small Bowel Diseases UCLA Medical CenterLos AngelesCAUnited States David Geffen School of Medicine at UCLALos AngelesCAUnited States

AIM： To determine the performance of novice readers （4^th year medical students） for detecting capsule endoscopy findings. METHODS： Ten capsule endoscopy cases of small bowel lesions were administered to the readers. Gold standard findings were pre-defined by gastroenterologists. Ten gold standard ＂targets＂ were identified among the 10 cases. Readers were given a 30-min overview of Rapid Reader software and instructed to mark any potential areas of abnormalities. A software program was developed using SAS to analyze the thumbnailed findings. RESULTS： The overall sensitivity for detecting the gold standard findings was 80%. As a group, at least 5 out of 10 readers detected each gold standard finding per recording. All the gold standard targets were identified when the readers＇ results were combined. Incidental finding/false positive rate ranged between 8.2-59.8 per reader. CONCLUSION： A panel of medical students with minimal endoscopic experience can achieve high sensitivity in detecting lesions on capsule endoscopy. A group of novice readers can pre-screen recordings to thumbnail potential areas of small bowel lesions for further review. These thumbnails must be reviewed to determine the clinical relevance. Further studies are ongoing to assess other cohorts.

关键词： Capsule endoscopy analysis Small bowel lesions Novice readers Sensitivity

Evaluation of site response characteristic using nonlinear method （Case study： Babol, Iran）

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Frontiers of Structural and Civil Engineering 2014年第1期8卷 69-82页

作者： Asskar Janalizadeh CHOOBBASTI Sadegh REZAEI Farzad FARROKHZAD pedram Haidarzaeh AZAR Department of Civil Engineering Babol University of Technology Babol Mazandaran 484 Iran

In this the present study, an attempt has been made to evaluate the seismic hazard considering local site effects by carrying out detailed geotechnical site characterization in Babol, Iran. Use of geotechnical data and synthesis of drilling data extracted from the Babol＇s subsurface database have enabled authors to determine the geotechnical properties of each site. These data are consisted of twenty five boreholes up to depth of 40 m. Based on the obtained data from geotechnical investigation the study area is divided to five zones. Dynamic analysis was performed in time domain, using fully nonlinear model by PLAXIS. A series of analysis in the study area showed the site period, ranging from 0.4 to 0.8 s. Finally the obtained response spectra from fully nonlinear method were compared with site response spectra of Iran＇s 2800 （earthquake） code.

关键词： fully nonlinear method site effect dynamic analysis response spectra

A system dynamics model for the assessment of the effects of advertising and sales promotion on profitability

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Journal of Modern Accounting and Auditing 2010年第10期6卷 12-26页

作者： Amir Ekhlassi pedram Tolouei Faculty of Management University of Tehran Tehran 15614 Iran

Advertising and sales promotion have significant impact on raising customer awareness. They are tools by which customers become acquainted with new and innovative products and services of the companies. Despite the importance of these tools in increasing sales, it is not easy to evaluate their effect on sales. One of the problems confronted by the marketing managers is the determination of a clear relationship between the effectiveness of advertising and sales promotion on profitability. In this article, considering the relationship between these tools and brand equity, we have attempted to determine the relationship between effectiveness of these two factors and profitability. Next, a system dynamics model for representing the effects of marketing communication tools on company profitability is offered. Finally, using the data from a corporation and the numeric values related to each of the elements in the model, an attempt has been made to determine a number representing the magnitude of the effect of advertising and sales promotion on the corporation＇s revenue and profitability and to draw the respective curves related to the effects of these two factors.

关键词： advertising sales promotion brand equity profitability system dynamics

Weighted Sum Rate Maximization in OFDM Based Cooperative Cognitive Radios: A Joint Optimization Approach

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International Journal of Communications, Network and System Sciences 2012年第5期5卷 263-271页

作者： pedram Johari Vahid Tabataba Vakili Communications Engineering Department School of Electrical Engineering Iran University of Science and Technology (IUST) Tehran Iran

Improving utilization of the radio spectrum is the main goal of Cognitive Radio Networks (CRN). Recent studies made use of cooperative relay technology in cognitive networks, to increase transmission diversity gain. In this paper we consider an OFDM based cooperative cognitive network with a pair of Source-Destination nodes as the primary user (PU), and a pair of Source-Destination nodes—which is assisted with a relay—as the secondary (cognitive) user (SU). Both primary and secondary users share a same spectrum. In a two hop transmission, the source transmits in the first hop, and the half-duplex relay decodes the message, re-encodes and forwards it to the destination in the second hop on a different subcarrier. The cognitive network obeys an underlay paradigm where the SU is allowed to transmit simultaneously with PU, while its power is limited such that the interference caused for PU does not exceed a defined temperature. Under this constraint, a joint subcarrier pairing and power allocation is proposed for SU to maximize its weighted sum rate. The problem is transformed to a convex optimization problem and solved in the dual domain. Then an algorithm to achieve feasible solutions is used based on the optimization results. Through extensive simulations, we compare the spectrum utilization of the proposed approach with the existing ones, and show that interestingly the proposed method improves the weighted sum rate of SU.

关键词： Cooperative Cognitive Radio Underlay Transmission OFDM Joint Optimization

Pericardial Rupture and Chronic Subluxation of the Heart: A Case Report

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World Journal of Cardiovascular Surgery 2021年第9期11卷 75-81页

作者： pedram Rajabifard Anurag Agarwal Peter Skillington Department of Cardiothoracic Surgery Royal Melbourne Hospital Victoria Australia

Background: Pericardial rupture is a rare diagnosis, usually occurring secondary to high energy blunt force trauma, which can result in subluxation of the heart. Aim: To determine a suitable method for repair of a pericardial defect post traumatic pericardial rupture. Case: We present a 55-year-old male who was found to have a large pericardial defect intra-operatively while undergoing an elective Ross procedure. The defect was repaired with a Gore-Tex membrane. The patient underwent revision sternotomy and repair of the pericardium due to inadequate laxity of the repaired pericardium resulting in hemodynamic instability. Conclusion: Synthetic membranes, such as Gore-Tex membranes, can be used successfully for repair of large pericardial defects but care must be taken to prevent undue tension secondary to taut repair, resulting in hemodynamic compromise.

关键词： Pericardial Rupture Pericardium Trauma Cardiac Trauma

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角膜共聚焦显微镜在干眼随访诊治中的应用

东南大学学报（医学版） 2015年第5期34卷 745-748页

作者：胡凯 HAMRAH pedram 东南大学附属中大医院眼科江苏南京210009 美国哈佛大学医学院附属麻省眼耳医院眼科美国波士顿02114

目的:评价角膜共聚焦显微镜检查在干眼随访诊治中的作用。方法:选取干眼新发病例150例(300眼),随机分为A、B两组,随访治疗半年。A组患者根据随访角膜共聚焦显微镜检查结果调整治疗方案,B组根据常规干眼检查结果调整治疗方案,两组所用具... 详细信息

目的:评价角膜共聚焦显微镜检查在干眼随访诊治中的作用。方法:选取干眼新发病例150例(300眼),随机分为A、B两组,随访治疗半年。A组患者根据随访角膜共聚焦显微镜检查结果调整治疗方案,B组根据常规干眼检查结果调整治疗方案,两组所用具体治疗药物及方法相同。结果:A组患者总的好转率为63%,明显高于B组的35%;并且经治疗后,A组患者的平均泪液分泌量(SⅠt)及泪膜破裂时间(BUT)明显好于B组。结论:根据角膜共聚焦显微镜检查结果调整干眼治疗方案效果明显好于传统随访治疗方案。

关键词：角膜共聚焦显微镜干眼治疗方案调整

An Adaptive Robust Approach to Modeling and Control of Flexible Arm Robots

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World Journal of Engineering and Technology 2018年第2期6卷 282-295页

作者： pedram Bagheri Laleh Behjat Qiao Sun Department of Electrical and Computer Engineering University of Calgary Calgary Alberta Canada Department of Mechanical and Manufacturing Engineering University of Calgary Calgary Alberta Canada

In this paper, a novel adaptive robust approach to modeling and control of a class of flexible-arm robots subject to actuators unmodeled dynamics is proposed. It is shown how real-time signals measured from a dynamical system can be utilized to improve the accuracy of the mathematical model of flexible robots. Given the elasticity of the robot’s arms, flexible manipulators have both passive and active degrees of freedom. A nonlinear robust controller is designed for the active degrees of freedom to enable the robot to follow desired trajectories in the presence of actuators unmodeled dynamics. Furthermore, it is shown that under some feasible conditions, another nonlinear robust controller is designed for the passive degrees of freedom. Moreover, to use the system response for model extraction, two auxiliary signals are proposed to provide sufficient information for improving the accuracy of the dynamics of the system numerically. Additionally, two adaptive laws are proposed in each case to update the two introduced auxiliary signals. As a result, the controller controls the passive degrees of freedom after the active degrees of freedom converge to their desired trajectories. Simultaneously, the information collected from the system to update the auxiliary signals enhances the model accuracy. In the end, simulation results are presented to verify the performance of the proposed controller.

关键词： Adaptive Control Robust Control Vibration Control

Application of a Rapid ESI-MS/MS Method for Quantitative Analysis of Docetaxel in Polymeric Matrices of PLGA and PLGA-PEG Nanoparticles through Direct Injection to Mass Spectrometer

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American Journal of Analytical Chemistry 2015年第2期6卷 164-175页

作者： pedram Rafiei Deborah Michel Azita Haddadi Division of Pharmacy College of Pharmacy and Nutrition University of Saskatchewan Saskatoon Canada

Docetaxel is a member of taxan family of antineoplastic agents widely used in cancer chemotherapy. However, application of conventional chemotherapy with commercial formulation has been accompanied with matters of concern regarding drug’s biodistribution, pharmacokinetics, and pharmacodynamics. Polymeric nanoparticles have been widely used as unique drug delivery vehicles to circumvent such problems. Docetaxel-loaded poly (lactide-co-glycolide) (PLGA) and poly (lactide-co-glycolide)-poly (ethylene glycol) (PLGA-PEG) nanoparticles fit well in modifying drug’s pharmacokinetic characteristics as intravenous (IV) sustained-release delivery vehicles. In such circumstances, characterization of nanoparticles in terms of their drug-payload would be a necessary step. The majority of studies have used HPLC analysis method for docetaxel quantitation in polymeric nanoparticles. Herein, a rapid ESI-MS/MS method for quantitative analysis of docetaxel in polymeric matrices of PLGA and PLGA-PEG nanoparticles through direct injection to mass spectrometer has been developed and validated. The assay was validated over a range of 3.9 - 1000 ng/ml and 125 - 16,000 ng/ml. Samples were directly injected to the instrument through an isocratic elution (0.1% formic acid in methanol) and detection was performed on a Hybrid Triple Quadrupole/Linear Ion trap mass spectrometer with multiple reaction monitoring (MRM) mode via positive electrospray ionization (ESI) source. The run time and retention time were 2 and 0.6 minutes respectively. The method demonstrated acceptable level of accuracy and precision and was successfully applied for quantitative analysis of docetaxel in polymeric nanoparticles of PLGA and PLGA-PEG.

关键词： Docetaxel EI-MS/MS Direct Injection Multiple Reaction Monitoring (MRM) Positive Electrospray Ionization (ESI+) PLGA PLGA-PEG

响应面法优化生物质灰处理TMP废水的工艺条件

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大连工业大学学报 2018年第1期37卷 28-34页

作者：孙勇慧刘忠 pedram FATEHI 天津科技大学天津市制浆造纸重点实验室天津300457 湖首大学化学工程系

研究了生物质灰(FA)去除热磨机械浆(TMP)废水中有机物的工艺条件,利用响应面Optimal Design建立数学模型,考察了FA质量浓度、温度和时间等影响因素对处理效果的影响。结果表明,FA处理TMP废水效果明显,建立的浊度、COD和木质素去除率的模... 详细信息

研究了生物质灰(FA)去除热磨机械浆(TMP)废水中有机物的工艺条件,利用响应面Optimal Design建立数学模型,考察了FA质量浓度、温度和时间等影响因素对处理效果的影响。结果表明,FA处理TMP废水效果明显,建立的浊度、COD和木质素去除率的模型,拟合情况良好,可预测任意期望值的去除率。增加FA用量、提高处理温度、延长处理时间有助于浊度、COD和木质素去除率的提高。FA处理TMP废水的最佳处理条件为:FA 100g/L,处理温度25℃,处理时间60min。此条件下处理的TMP废水,浊度为27.60NTU,COD为0.44g/L,木质素和半纤维的质量浓度分别为0.04和0.01g/L;浊度、COD和木质素去除率分别为96.2%、79.3%和95.4%。

关键词：生物质灰热磨机械浆 TMP废水响应面法