An LMI Approach to Robust Iterative Learning Control for Linear Discrete-time Systems

Mojtaba Ayatinia,Mehdi Forouzanfar,Amin Ramezani 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.7

This paper presents a new robust convergence condition of iterative learning control (ILC) for linear multivariable discrete-time systems in the presence of iteration-varying uncertainty. This method is based on linear matrix inequality (LMI) and provides a fixed learning gain over time and iteration. Since the convergence of the ILC algorithm may change due to uncertainty in the parameters of a system, and the ILC algorithm is incapable of dealing with iteration-related challenges, it is a major challenge to reject the effect of iteration varying uncertainty. In this paper, first, a convergence condition of the ILC algorithm is designed based on closed-loop system stability in the iteration domain, and second, a new robust convergence condition is achieved by the LMI approach. Finally, the effectiveness of the proposed robust convergence scheme is evaluated through two numerical examples.

Inhibitory Effects of Apium graveolens on Xanthine Oxidase Activity and Serum Uric Acid Levels in Hyperuricemic Mice

Karim Dolati,Hassan Rakhshandeh,Mohsen Golestani,Fatemeh Forouzanfar,Roya Sadeghnia,Hamid R. Sadeghnia 한국식품영양과학회 2018 Preventive Nutrition and Food Science Vol.23 No.2

Celery (Apium graveolens) is traditionally used to treat rheumatism and cardiovascular disorders. Hyperuricemia is considered as a predisposing factor for gout and is also suggested to be associated with coronary artery disease. In the present study, the effect of hydroalcoholic extracts from A. graveolens (AGE) against potassium oxonate (PO)-induced hyperuricemia was investigated in mice. AGE (250, 500, and 1,000 mg/kg) or allopurinol (5 mg/kg, as positive control) were orally administrated 1 h after PO injection (250 mg/kg, ip) for two weeks. After that, the serum uric acid level and hepatic xanthine dehydrogenase (XDH) and xanthine oxidase (XO) activities were measured. In addition, the antioxidant activity of AGE was determined by assessment of hepatic lipid peroxidation, in vivo and the ferric reducing/antioxidant power assay, in vitro. The extract exhibited good capacity to reduce ferric ion to ferrous ion with mean value of 63.8±8.5 μmol/g. The data also showed that oxonate treatment produced a significant increase in serum uric acid level (4.6 vs. 2.3 mg/ dL, P<0.001), liver XO/XDH activities (P<0.01 and P<0.001, respectively), and hepatic lipid peroxides levels (about two fold, P<0.01), compared to the healthy mice. AGE significantly decreased the serum uric acid level, hepatic XO/XDH activities, and lipid peroxidation, in a dose-dependent manner. Oral administration of 1,000 mg/kg AGE for two weeks reversed the elevated serum uric acid level (2.7 vs. 4.6 mg/dL, P<0.001) and significantly inhibited liver XO/XDH activities (P<0.001) and diminished hepatic lipid peroxidation (0.45 vs. 0.82 nmol/mg protein, P<0.05), compared with hyperuricemic mice. AGE (1,000 mg/kg) per se did not significantly modify these parameters. Our results demonstrated that AGE could reduce the serum uric acid level via inhibition of hepatic XDH/XO and indicated its potential utility as an effective hypouricemic bioactive agent or functional food.

Frequency of posttrauma complications during hospital admission and their association with Injury Severity Score

Dasdar Shayan,Yousefifard Mahmoud,Ranjbar Mehri Farhang,Forouzanfar Mehdi,Mazloom Hamid,Safari Saeed 대한응급의학회 2023 Clinical and Experimental Emergency Medicine Vol.10 No.4

Objective Multiple trauma is associated with a remarkable risk of in-hospital complications, which harm healthcare services and patients. This study aimed to assess the incidence of posttrauma complications, their relationship with poor outcomes, and the effect of the Injury Severity Score (ISS) on their occurrence.Methods This retrospective cohort study was conducted at a pair of trauma centers, between January 2020 and December 2022. All hospitalized adult patients with multiple trauma were included in this study. Multivariable logistic regression was used to identify factors related to posttrauma complications.Results Among 727 multiple trauma patients, 90 (12.4%) developed in-hospital complications. The most frequent complications were pneumonia (4.8%), atelectasis (3.7%), and superficial surgical site infection (2.5%). According to multivariable logistic regression, ISS, the length of stay in the intensive care unit (ICU), the length of stay in the hospital, and mortality were significantly associated with complications. The complication rate increased by 17% with every single-unit increase in ISS (adjusted odds ratio [OR], 1.17; 95% confidence interval [CI], 1.00–1.38). Per every 1-day increase in the ICU or hospital stay, the complication rate increased by 65% (adjusted OR, 1.65; 95% CI, 1.00–2.73) and 20% (adjusted OR, 1.20; 95% CI, 1.03–1.41), respectively. Posttrauma complications were also significantly more common in patients with mortality (adjusted OR, 163.30; 95% CI, 3.04–8,779.32). In multiple trauma patients with a higher ISS, the frequency, severity, and number of complications were significantly increased.Conclusion In-hospital complications in multiple trauma patients are frequent and associated with poor outcomes and mortality. ISS is an important factor associated with posttrauma complications.

Establishing cleft services in developing countries: Complications of cleft lip and palate surgery in rural areas of Indonesia

Ruslin, Muhammad,Dom, Lawrence,Tajrin, Andi,Yusuf, Andi Sitti Hajrah,Arif, Syafri Kamsul,Tanra, Andi Husni,Ou, Keng Liang,Forouzanfar, Tymour,Thamrin, Sri Astuti Korean Society of Plastic and Reconstructive Surge 2019 Archives of Plastic Surgery Vol.46 No.6

Background Cleft treatment is frequently performed in Indonesia, mostly in charity missions, but without a postoperative protocol it is difficult to establish the risks and complications of cleft treatment. The present study was designed to give an overview of current cleft lip and palate treatment strategies in Indonesia and to assess the complication rates during and after surgery. Methods This prospective study evaluated anesthetic, intraoperative surgical, and short-term postoperative complications in patients undergoing primary, secondary, or corrective surgery for cleft lip and palate deformities. The population consisted of 98 non-syndromic cleft patients. The main anesthetic complication that occurred during general anesthesia was high blood pressure, whereas the main intraoperative surgical complication was excessive bleeding and the main early postoperative complication was extremely poor wound hygiene. Results In this study, there were no cases of perioperative or postoperative mortality. However, in 23 (23.4%) of the 98 operations performed, at least one perioperative complication related to anesthesia occurred. The intraoperative and early postoperative complications following cleft lip and/or palate were assessed. There was a significant difference in the complication rate between procedure types (χ²=0.02; P<0.05). However, no relationship was found between perioperative complications related to anesthesia and the occurrence of postoperative complications (χ²=1.00; P>0.05). Nonetheless, a significant difference was found between procedure types regarding perioperative complications and the occurrence of postoperative complications (χ²=0.031; P<0.05). Conclusions Further evaluation of these outcomes would help direct patient management toward decreasing the complication rate.

Establishing cleft services in developing countries: Complications of cleft lip and palate surgery in rural areas of Indonesia

Muhammad Ruslin,Lawrence Dom,Andi Tajrin,Andi Sitti Hajrah Yusuf,Syafri Kamsul Arif,Andi Husni Tanra,Keng Liang Ou,Tymour Forouzanfar,Sri Astuti Thamrin 대한성형외과학회 2019 Archives of Plastic Surgery Vol.46 No.6

Background Cleft treatment is frequently performed in Indonesia, mostly in charity missions,but without a postoperative protocol it is difficult to establish the risks and complicationsof cleft treatment. The present study was designed to give an overview of current cleftlip and palate treatment strategies in Indonesia and to assess the complication rates duringand after surgery. Methods This prospective study evaluated anesthetic, intraoperative surgical, and short-termpostoperative complications in patients undergoing primary, secondary, or corrective surgeryfor cleft lip and palate deformities. The population consisted of 98 non-syndromic cleft patients. The main anesthetic complication that occurred during general anesthesia was highblood pressure, whereas the main intraoperative surgical complication was excessive bleedingand the main early postoperative complication was extremely poor wound hygiene. Results In this study, there were no cases of perioperative or postoperative mortality. However,in 23 (23.4%) of the 98 operations performed, at least one perioperative complicationrelated to anesthesia occurred. The intraoperative and early postoperative complications followingcleft lip and/or palate were assessed. There was a significant difference in the complicationrate between procedure types (χ2=0.02; P<0.05). However, no relationship was foundbetween perioperative complications related to anesthesia and the occurrence of postoperativecomplications (χ2=1.00; P>0.05). Nonetheless, a significant difference was found betweenprocedure types regarding perioperative complications and the occurrence of postoperativecomplications (χ2=0.031; P<0.05). Conclusions Further evaluation of these outcomes would help direct patient managementtoward decreasing the complication rate.