Frequency Response Model of Power System in Presence of Thermal, Wind and Hydroelectric Units

Darani Shirin Hassanzadeh,Rabbanifar Payam,Aliabadi Mahmood Hosseini,Radmanesh Hamid 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.4

Loss of large generation units or unforeseen changes in consumption load causes disturbances in power system operation. Operators face serious challenges by increasing the penetration level of renewable energies in unit commitment and inability of these resources in providing inertial frequency response. Therefore, having system frequency response model makes operators to have a better understanding of system function and frequency behavior encounter disturbances and critical situations. This paper, studies the importance and necessity of recognizing the frequency response model and presents an integrated model of system frequency response in the presence of thermal, wind and hydroelectric units. Using the Routh stability criterion method, the proposed fifth-order model converts to a second-order model with an acceptable approximation. Proposed system frequency response in a six-bus power system is investigated and effect of changes in the main components on the frequency behavior of system is checked out. Researchers can linearize the obtained frequency response model using conventional linearization methods and use it as a frequency constraint in optimization and security-constrained unit commitment problems. Besides that, frequency behavior of the power system consisting of thermal units after addition of wind and hydroelectric units is studied. This paper helps researchers to have simplified calculation, beneficial and accurate results, while saving time, money and fossil reserves.

Somatic Complaints Are Significantly Associated with Chronic Uninvestigated Dyspepsia and Its Symptoms: A Large Cross-sectional Population Based Study

( Zahra Heidari ),( Ammar Hassanzadeh Keshteli ),( Awat Feizi ),( Hamid Afshar ),( Payman Adibi ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2017 Journal of Neurogastroenterology and Motility (JNM Vol.23 No.1

Background/Aims Somatization may influence persistence and severity of symptoms in gastrointestinal diseases. Some studies suggest that somatization is associated with chronic uninvestigated dyspepsia (CUD); however, the association is unclear. We aimed to determine the association between the profiles of somatic complaints with CUD and its symptoms. Methods In a cross-sectional study conducted on 4763 Iranian adults, somatic complaints were assessed using a comprehensive 31-items questionnaire. Patients with CUD were identified by the Rome III diagnostic criteria. Profiles of somatic complaints were derived from factor analysis. Logistic regression analysis was used to assess the relationship between extracted profiles with CUD and its symptoms. Results CUD, bothersome postprandial fullness, early satiation, and epigastric pain or burning was identified in 723 (15.2%), 384 (8.1%), 302 (6.3%), and 371 (7.8%) of the study population. The frequency of all 31 somatic complaints was significantly higher in patients with CUD compared with controls (P < 0.001), and the most frequent was severe fatigue (45.1%). The profiles of somatic complaints were extracted in 4 domains, including “psychological”, “gastrointestinal”, “neuro-skeletal”, and “pharyngeal-respiratory”. The psychological (OR, 1.49; 95% CI, 1.44-1.54), gastrointestinal (OR, 2.22; 95% CI, 2.09-2.37), neuro-skeletal (OR, 1.52; 95% CI, 1.44- 1.59), and pharyngeal-respiratory (OR, 2.09; 95% CI, 1.94-2.25) profiles were significantly associated with greater odds of CUD. Conclusions CUD and its symptoms are strongly associated with higher levels of somatic complaints and their related extracted profiles. This perhaps explains that why it can be difficult to treat, however further prospective investigations are required to confirm these associations. (J Neurogastroenterol Motil 2017;23:80-91)

Analysis of survival data in thalassemia patients in Shiraz, Iran

Abdolreza Rajaeefard,Mahmoud Hajipour,Hamid Reza Tabatabaee,Jafar Hassanzadeh,Shahab Rezaeian,Zahra Moradi,Mehdi Sharafi,Mohsen Shafiee,Ali Semati,Sanaz Safaei,Maryam Soltani 한국역학회 2015 Epidemiology and Health Vol.37 No.-

OBJECTIVES: The survival rate of thalassemia patients has not been conclusively established, and the factors associated with survival remain unclear. This study aimed to determine the survival rate of thalassemia among patients in southern Iran and to identify the factors associated with mortality from thalassemia. METHODS: This retrospective cohort study was conducted based on a retrospective review of the medical records of 911 beta-thalassemia patients in 2014. Data analysis was conducted using the Kaplan-Meier method and Cox regression analysis. RESULTS: Overall, 212 patients (23.3%) died, and 26.8% had thalassemia intermedia. The 20-year, 40-year, and 60-year survival rates were 85%, 63%, and 54%, respectively. Both crude and adjusted analyses found that education, marital status, ferritin levels, and comorbidities were related to mortality. CONCLUSIONS: Sociodemographic and hematological factors were found to be significantly associated with the survival rate of thalassemia. Addressing these factors may help healthcare providers and physicians to provide the best possible care and to improve the survival rate.

Effects of nine weeks L-Carnitine supplementation on exercise performance, anaerobic power, and exercise-induced oxidative stress in resistance-trained males

Majid S. Koozehchian,Amin Daneshfar,Ebrahim Fallah,Hamid Agha-alinejad,Mohammad Samadi,Mojtaba Kaviani,Maryam Kaveh B,Y. Peter Jung,Mozhgan Hassanzadeh Sablouei,Najmeh Moradi,Conrad P. Earnest,T. Jeff 한국운동영양학회 2018 Physical Activity and Nutrition (Phys Act Nutr) Vol.22 No.4

[Purpose] Studies of L-carnitine in healthy athletic populations have yielded equivocal results. Further scientific-based knowledge is needed to clarify the ability of L-carnitine to improve exercise capacity and expedite the recovery process by reducing oxidative stress. This study aimed to examine the 9-week effects of L-carnitine supplementation on exercise performance, anaerobic capacity, and exercise-induced oxidative stress markers in resistance-trained males. [Methods] In a double-blind, randomized, and placebo-controlled treatment, 23 men (age, 25±2y; weight, 81.2±8.31 kg; body fat, 17.1±5.9%) ingested either a placebo (2 g/d, n=11) or L-carnitine (2 g/d, n=12) for 9 weeks in conjunction with resistance training. Primary outcome measurements were analyzed at baseline and at weeks 3, 6, and 9. Participants underwent a similar resistance training (4 d/w, upper/lower body split) for a 9-week period. Two-way ANOVA with repeated measures was used for statistical analysis. [Results] There were significant increases in bench press lifting volume at wk-6 (146 kg, 95% CI 21.1, 272) and wk-9 (245 kg, 95% CI 127, 362) with L-carnitine. A similar trend was observed for leg press. In the L-carnitine group, at wk-9, there were significant increases in mean power (63.4 W, 95% CI 32.0, 94.8) and peak power (239 W, 95% CI 86.6, 392), reduction in post-exercise blood lactate levels (-1.60 mmol/L, 95% CI -2.44, -0.75) and beneficial changes in total antioxidant capacity (0.18 mmol/L, 95% CI 0.07, 0.28). [Conclusion] L-carnitine supplementation enhances exercise performance while attenuating blood lactate and oxidative stress responses to resistance training.

Effect of aortic spiral blood flow on wall shear stress in stenosed left main coronary arteries with varying take-off angle, stenosis severity and eccentricity

Abouzar Moshfegh,Ashkan Javadzadegan,Zhaoqi Zhang,Hamid Hassanzadeh Afrouzi,Mohammad Omidi 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.8

It is well accepted that blood flow in the human aorta is spiral by nature, with beneficial impacts for the cardiovascular system in the form of improved haemodynamics and efficient perfusion. This study investigates the effect of aortic spiral blood flow on wall shear stress (WSS) in computer-generated models of the left main trunk (LMT), also known as left main coronary artery, with varying take-off angle, stenosis severity and eccentricity. The results show that the spirality effect causes a substantial reduction in maximum WSS (WSS max ), average WSS (WSS ave ) and size of regions with low WSS. The effects of spiral flow on WSS max become more significant with increasing LMT take-off angle and stenosis eccentricity, and they become less significant with increasing stenosis severity. The aortic spiral blood flow intensity, LMT take-off angle, stenosis severity and eccentricity statistically significantly predict the WSS; however, the strongest predictor of WSS is stenosis severity (F(4, 399) = 3653.85, p < 0.001 for WSS max and F(4, 399) = 913.46, p < 0.001 for WSS ave ), followed by LMT take-off angle (F(4, 399) = 582.735, p < 0.001 for WSS max and F(4, 399) = 163.16, p < 0.001 for WSS ave ), stenosis eccentricity (F(4, 399) = 230.15, p < 0.001 for WSS max and F(4, 399) = 52.94, p < 0.001 for WSS ave ) and blood flow spirality (F(4, 399) = 112.37, p < 0.001 for WSS max and F(4, 399) = 32.18, p < 0.001 for WSS ave ). Our findings suggest that naturally or artificially induced spiral flow in the aorta potentially has atheroprotective effects in the LMT.

Relationship between Depression and Constipation: Results from a Large Cross-sectional Study in Adults

Peyman Adibi,Maryam Abdoli,Hamed Daghaghzadeh,Ammar Hassanzadeh Keshteli,Hamid Afshar,Hamidreza Roohafza,Ahmad Esmaillzadeh,Awat Feizi 대한소화기학회 2022 대한소화기학회지 Vol.80 No.2

Background/Aims: Accumulating evidence based on a few studies suggests a relationship between depression and functional constipation. This study examined whether depression is associated with a higher risk of functional constipation and whether it is gender specific. Methods: This cross-sectional study was carried out on 3,362 adults aged 18-55 years. In this study, functional gastrointestinal symptoms were determined using an Iranian reliable and valid version of the modified Rome III questionnaire. The Iranian validated version of the hospital anxiety and depression scale was used to evaluate the psychological health. Scores of eight or more on the depression subscale in the questionnaire were considered the presence of depression. Simple and multiple binary logistic regression were used for data analysis. Results: The mean±SD age of participants was 36.29±7.87 years, and 58.5% were female. The prevalence of depression and constipation in the study sample was 28.6% and 23.9%, respectively. In the full adjusted model, in the total sample, depressed people showed a significantly higher risk of constipation; adjusted OR (AOR), 1.69 (95% CI, 1.37-2.09). Although a significant association was observed between depression and constipation in both genders, the association was stronger in men than women (AOR, 2.28; 95% CI, 1.50, 3.63 vs. AOR, 1.55; 95% CI, 1.21, 1.99). Conclusions: These study findings showed that depressed people are at a significantly higher risk of being affected by constipation. The current study findings justify the importance of mental health evaluations in all patients with functional gastrointestinal disorders, particularly among constipated individuals.

Chronic Opioid Use Following Lumbar Discectomy: Prevalence, Risk Factors, and Current Trends in the United States

Andrew B. Harris,Bo Zhang,Majd Marrache,Varun Puvanesarajah,Micheal Raad,Hamid Hassanzadeh,Mark Bicket,Amit Jain 대한척추신경외과학회 2020 Neurospine Vol.17 No.4

Objective: Lumbar discectomy is commonly performed for symptomatic lumbar disc herniation. We aimed to examine prescribing patterns and risk factors for chronic opioid use following lumbar discectomy. Methods: Using a private insurance claims database, patients were identified who underwent primary lumbar discectomy from 2010–2015 and had 1-year of continuous enrollment postoperatively. Patients were excluded with spinal fusion. The strength of opioid prescriptions was quantified using morphine milligram equivalents daily (MMED). Univariate and multivariate logistic regression models were built to examine risk factors associated with chronic postoperative opioid use. Results: A total of 5,315 patients were included in the study (mean age, 59 years; 50% female). 1,198 of patients (23%) used chronic opioids postoperatively. Chronic opioid use declined significantly from 27% in 2010 to 17% in 2015, p<0.001. In addition, there were significantly fewer patients receiving high and very high-dose opioid prescriptions from 2010–2015, p<0.001. The median duration that patients used opioids postoperatively was 211 days in 2010 (interquartile range [IQR], 29–356 days), and decreased significantly to 44 days (IQR, 10–294 days) in 2015. The strongest factors associated with chronic opioid use were preoperative opioid use (odds ratio [OR], 4.0), drug abuse (OR, 2.6), depression (OR, 1.6), surgery in the west (OR, 1.6) or south (OR, 1.6), anxiety (OR, 1.5), or 30-day readmission (OR, 1.4). Conclusion: Chronic opioid use following primary lumbar discectomy has declined from 2010–2015. A variety of factors are associated with chronic opioid use. Preoperative recognition of some of these risk factors may aid in perioperative management and counseling.

Antileishmanial Activity of Niosomal Combination Forms of Tioxolone along with Benzoxonium Chloride against Leishmania tropica

Maryam Hakimi Parizi,Saeedeh Farajzadeh,Iraj Sharifi,Abbas Pardakhty,Mohammad Hossein Daie Parizi,Hamid Sharifi,Ehsan Salarkia,Saeid Hassanzadeh 대한기생충학ㆍ열대의학회 2019 The Korean Journal of Parasitology Vol.57 No.4

In this study, we carried out extensive in vitro studies on various concentrations of tioxolone along with ben- zoxonium chloride and their niosomal forms against Leishmania tropica. Niosomes were prepared by the hydration meth- od and were evaluated for morphology, size, release study, and encapsulation efficiency. This study measured leishmani- cidal activity against promastigote and amastigote, apoptosis and gene expression levels of free solution and niosomal- encapsulated tioxolone along with benzoxonium chloride. Span/Tween 60 niosome had good physical stability and high encapsulation efficiency (more than 97%). The release profile of the entrapped compound showed that a gradual release rate. The combination of niosomal forms on promastigote and amastigote were more effective than glucantime. Also, the niosomal form of this compound was significantly less toxic than glucantime (P ≤ 0.05). The flowcytometric analysis on niosomal form of drugs showed that higher number of early apoptotic event as the principal mode of action (89.13% in 200 μg/mL). Also, the niosomal compound increased the expression level of IL-12 and metacaspase genes and de- creased the expression level of the IL-10 gene, which further confirming the immunomodulatory role as the mechanism of action. We observed the synergistic effects of these 2 drugs that induced the apoptotic pathways and also up regulation of an immunomodulatory role against as the main mode of action. Also, niosomal form of this combination was safe and demonstrated strong anti-leishmaniasis effects highlights further therapeutic approaches against anthroponotic cutane- ous leishmaniasis in future planning.

Demographic Trends in Paddle Lead Spinal Cord Stimulator Placement: Private Insurance and Medicare Beneficiaries

Lawal Labaran,Joshua Bell,Varun Puvanesarajah,Nikhil Jain,Jomar N. Aryee,Micheal Raad,Amit Jain,Jonathan Carmouche,Hamid Hassanzadeh 대한척추신경외과학회 2020 Neurospine Vol.17 No.2

Objective: Although spinal cord stimulators (SCS) continue to gain acceptance as a viable nonpharmacologic option for the treatment of chronic back pain, recent trends are not well established. The aim of this study was to evaluate recent overall demographic and regional trends in paddle lead SCS placement and to determine if differences in trends exist between private-payer and Medicare beneficiaries. Methods: A retrospective review of Medicare and private-payer insurance records from 2007–2014 was performed to identify patients who underwent a primary paddle lead SCS placement via a laminectomy (CPT-63655). Each study cohort was queried to determine the annual rate of SCS placements and demographic characteristics. Yearly SCS implanta�tion rates within the study cohorts were adjusted per 100,000 beneficiaries. A chi-square analysis was used to compare changes in annual rates. Results: A total of 31,352 Medicare and 2,935 private-payer patients were identified from 2007 to 2014. Paddle lead SCS placements ranged from 5.9 to 17.5 (p<0.001), 1.9 to 5.9 (p<0.001), and 5.2 to 14.5 (p<0.001) placements per 100,000 Medicare, private-payer, and overall beneficiaries respectively from 2007 to 2014. SCS placements peaked in 2013 with 19.6, 7.1, and 16.8 placements per 100,000 Medicare, private-payer, and overall patients. Conclusion: There was an overall increase in the annual rate of SCS placements from 2007 to 2014. Paddle lead SCS placements peaked in 2013 for Medicare, private-payer, and over�all beneficiaries. The highest incidence of implantation was in the Southern region of the United States and among females. Yearly adjusted rates of SCSs were higher among Medi�care patients at all time points.

Opioids and Spinal Cord Stimulators: Pre- and Postoperative Opioid Use Patterns and Predictors of Prolonged Postoperative Opioid Use

Lawal Labaran,Jomar N.A. Aryee,Joshua Bell,Nikhil Jain,Varun Puvanesarajah,Michael Raad,Amit Jain,Jonathan Carmouche,Hamid Hassanzadeh 대한척추신경외과학회 2020 Neurospine Vol.17 No.1

Objective: The aim of the study was to compare trends and differences in preoperative and prolonged postoperative opioid use following spinal cord stimulator (SCS) implantation and to determine factors associated with prolonged postoperative opioid use. Methods: A database of private-payer insurance records was queried to identify patients who underwent a primary paddle lead SCS placement via a laminectomy (CPT-C3655) from 2008–2015. Our resulting cohort was stratified into those with prolonged postoperative opioid use, opioid use between 3- and 6-month postoperation, and those without. Multivariate logistic regression was used to determine the effect preoperative opioid use and other factors of interest had on prolonged postoperative opioid use. Subgroup analysis was performed on preoperative opioid users to further quantify the effect of differing magnitudes of preoperative opioid use. Results: A total of 2,374 patients who underwent SCS placement were identified. Of all patients, 1,890 patients (79.6%) were identified as having prolonged narcotic use. Annual rates of preoperative (p=0.023) and prolonged postoperative narcotic use (p<0.001) decreased over the study period. Significant independent predictors of prolonged postoperative opioid use were age <65 years (odds ratio [OR], 1.52; p=0.004), male sex (OR, 1.33; p=0.037), preoperative anxiolytic (OR, 1.55; p=0.004) and muscle relaxant (OR, 1.42; p=0.033), and narcotic use (OR, 15.04; p<0.001). Increased number of preoperative narcotic prescriptions correlated with increased odds of prolonged postoperative use. Conclusion: Patients with greater number of preoperative opioid prescriptions may not attain the same benefit from SCSs as patients with less opioid use. The most significant predictor of prolonged narcotic use was preoperative opioid use.