ROBUST DISTURBANCE REJECTION FOR A CLASS OF NONLINEAR SYSTEMS USING DISTURBANCE OBSERVERS

ABSTRACT This paper is concerned with disturbance rejection performance in single-input single-output (SISO) nonlinear Introduction This paper is concerned with disturbance rejection for a class of single-input single-output (SISO) nonlinear systems. The system dynamics is comprised of a linear part subject to norm-bounded uncertainty , and a vector-valued bounded nonlinearity which is not known exactly. Given an internally stabilizing controller which renders the nominal linear dynamics exponentially stable, the nonlinearities can be represented as a bounded disturbance d (t) ∈ R at the output of a linear system. A disturbance observer (DOB) is then introduced into the feedback system to eliminate the effect of d (t) in the presence of the linear plant uncertainty. The main objective in this paper is to enhance performance robustness of a given class of SISO nonlinear feedback system

Physiotherapeutic protocol and ZnO nanoparticles: a combined novel treatment program against bacterial pyomyositis

Myositis tropicans or pyomyositis is a muscle inflammation resulting from a bacterial infection of skeletal muscle (commonly caused by Staphylococcus aureus) that usually leads to hematogenous muscle seeding. The present study was designed to estimate the role of ZnO-NPs and a physiotherapeutic program in the management of induced biceps femoris atrophy in rats through histological, biochemical, and radiological examinations at different time intervals. At the beginning, several bacterial strains were evaluated through a proteolytic enzyme activity assay and the highest activity was recorded with the Staphylococcus aureus strain. ZnO-NPs were synthesized with the arc discharge method with an average size of 19.4 nm. The antibacterial activity of ZnO-NPs was investigated and it was revealed that the prepared ZnO-NPs showed a minimum inhibitory concentration of 8 µg/mL against the tested bacterium. The cytotoxicity of the prepared ZnO-NPs was tested in C2C12 myoblast cells, and it was elaborated that CC50 was 344.16 µg/mL. Biceps femoris pyomyositis was induced with a potent strain (Staphylococcus aureus); then, a physiotherapeutic program combined with the prepared ZnO-NPs treatment protocol was applied and evaluated. The combined program claimed antibacterial properties, preventing muscle atrophy, and resulted in the most comparable value of muscle mass

Evaluation of erythropoietin hormone in chronic obstructive pulmonary disease patients during exacerbation and after remission

Introduction: It has long been known that COPD causes polycythemia secondary to erythrocytosis caused by hypoxia present in advanced cases of COPD. However, it was shown in several studies that some COPD patients had anemia rather than erythrocytosis Aim: The aim of this work was to assess the changes in erythropoietin in COPD patients during exacerbation and after remission. Subjects and methods: This work was done on 50 subjects, Group 1:40 COPD patients plus Group I 1: 10 age matched apparently healthy control subjects. For all history taking, full clinical exam, PFTs (spirometry), EPO hormone measurement on human serum by ELIZA (EPO hormone was measured during exacerbation and after remission), oxygen saturation and routine labs (CBC, Liver and Renal function) were performed. Results: Level of erythropoietin hormone was significantly higher in COPD patients with mean (21.92 ± 6.64 mU/ml) than control with mean (9.42 ± 1.5 mU/ml) and higher during remission (24.21 ± 6.58 mU/ml) than during exacerbation (21.92 ± 6.64 mU/ml), also was significantly higher during remission in grade (II, III) (25.68 ± 2.57, 33.71 ± 2.16 mU/ml) than grade (I, IV) (16.04 ± 0.89, 19.39 ± 1.28 mU/ml) COPD patients respectively. Erythropoietin hormone level was significantly higher in anemic than non anemic COPD patients. It was (27.94 ± 6.33 mU/ml) (20.84 ± 4.83 mU/ml) respectively, and it was significantly inversely related to oxygen saturation & both of HB and Hct in COPD patients. Conclusion: EPO hormone level was significantly higher in grade (II, III) than grade (I, IV) COPD patients (p = 0.005), and also COPD with anemia was higher in stage (II, III) than stage (I, IV), EPO hormone level significantly higher in anemic than non anemic COPD patients and was significantly higher (p = 0.005) during remission than during exacerbation

A magnetic bilateral tele-manipulation system using paramagnetic microparticles for micromanipulation of nonmagnetic objects

This study presents a scaled-bilateral telemanipulation system for magnetic-based control of paramagnetic microparticles. This bilateral control system consists of a haptic device (master-robot) and an electromagnetic system with four orthogonal electromagnetic coils. The electromagnetic system generates magnetic field gradients to control the motion of the microparticle (slave-microrobot). A systematic robust tele-manipulation control design of the microparticles is achieved using disturbance observers (DOBs) to estimate the interaction forces at both the master-robot and slave-microrobot. Experimental results show that point-To-point motion control of the slave-microrobots results in maximum position error of 8 μm in the steady-state. Furthermore, we demonstrate experimentally that interaction forces of tens of micro Newtons, between the slave-microrobot and non-magnetic microbeads, can be estimated using DOBs and scaled-up to the sensory range of the operator

The Utilization of Sodium Lignosulphonate Extracted From Egyptian Rice Straw in Leather Tanning Process

Massive quantities of rice straw are burned annually in Egypt and caused environmental hazards. The present study investigated the utilization of rice straw to produce sodium lignosulphonate (SLS) as a water-soluble derivative of lignin in leather tanning and evaluate its usage as a tanning or re-tanning material as well as its effect on leather quality. The results of testing SLS as a leather tanning agent were unsatisfactory due to its slight effect on shrinkage temperature of leathers, unlike its use as a re-tanning material. Four concentrations of SLS (0%, 5%, 10%, and 20%) were used in re-tanning forty of sheep wet-blues. The results showed that using SLS as a re-tanning agent with concentration till 10% from pelts weight enhances some organoleptic properties, such as fullness and general appearance together with slight improvement in physical properties of leathers. Moreover, the addition of SLS with concentration 20% led to an excessive swelling in the collagen fibers as shown from depicted scanning electron micrographs and decreased trends of physical properties

The Utilization of Sodium Lignosulphonate Extracted From Egyptian Rice Straw in Leather Tanning Process

Massive quantities of rice straw are burned annually in Egypt and caused environmental hazards. The present study investigated the utilization of rice straw to produce sodium lignosulphonate (SLS) as a water-soluble derivative of lignin in leather tanning and evaluate its usage as a tanning or re-tanning material as well as its effect on leather quality. The results of testing SLS as a leather tanning agent were unsatisfactory due to its slight effect on shrinkage temperature of leathers, unlike its use as a re-tanning material. Four concentrations of SLS (0%, 5%, 10%, and 20%) were used in re-tanning forty of sheep wet-blues. The results showed that using SLS as a re-tanning agent with concentration till 10% from pelts weight enhances some organoleptic properties, such as fullness and general appearance together with slight improvement in physical properties of leathers. Moreover, the addition of SLS with concentration 20% led to an excessive swelling in the collagen fibers as shown from depicted scanning electron micrographs and decreased trends of physical properties

Childhood glaucoma profile in Dakahelia, Egypt: a retrospective study

AIM: To analyze childhood glaucoma regarding its demographics, presentations, different causes and surgical modalities used among patients in Dakahelia and to apply the Childhood Glaucoma Research Network (CGRN) classification retrospectively to evaluate its convenience. METHODS: A retrospective study in which the medical files of all glaucoma patients <16 years old presented to Mansoura Ophthalmic Center, Mansoura University from 2014 to 2017, were retrieved and analyzed. Collected data included: age, gender, laterality, visual acuity (VA), refraction, intraocular pressure (IOP), corneal diameter, cup-disc ratio, types and number of surgeries and antiglaucomatous drugs (AGD) at the first and last visit. Prevalence of different subtypes was calculated and means of clinical features were compared. RESULTS: A total of 305 eyes of 207 patients were included classified into 6 groups: primary congenital glaucoma (PCG), juvenile open angle glaucoma (JOAG), glaucoma associated with systemic disease, glaucoma associated with ocular anomalies, acquired glaucoma and glaucoma following cataract surgery. PCG was the predominant type (55.1%) followed by acquired glaucoma (29.5%). Males represented 63.8% of the whole studied patients. Glaucoma associated with ocular anomaly group showed the youngest age at diagnosis (21.9±30.0mo). The shortest corneal diameter was recorded in post cataract group (10.4±0.5 mm). Highest cup-disc ratio was found in the PCG group (P<0.0005). Glaucoma associated with systemic disease presented with the highest baseline IOP (34.5±5.0 mm Hg). All the cases with PCG were treated surgically with 21.8% required more than one surgery. The majority of the patients (74.2%) in the acquired group were treated medically. Combined trabeculotomy-trabeculectomy was the most frequent operation done, accounting for 34.5% of all primary surgeries. Ahmed valve implantation comprised 87% of the secondary surgeries. Acquired glaucoma group had the highest percent of eyes with good final Snellen's VA (69.4%), while glaucoma associated with ocular anomaly group had poorest final VA. CONCLUSION: PCG is the most prevalent type of childhood glaucoma, followed by acquired glaucoma especially traumatic hyphema. Combined trabeculotomy-trabeculectomy and Ahmed valve implantation are the most common surgical interventions. CGRN classification is found to provide a consensus skeleton and is recommended to be integrated in our routine ongoing clinical practice

Thymoquinone-PLGA-PVA Nanoparticles Ameliorate Bleomycin-Induced Pulmonary Fibrosis in Rats via Regulation of Inflammatory Cytokines and iNOS Signaling

Pulmonary fibrosis is considered one of the most chronic interstitial illnesses which are not easily treated. thymoquinone&rsquo;s (TQ) benefits are still partly problematic due to poor water solubility; therefore, it was loaded onto PLGA-PVA carriers. This study aimed to evaluate the potential effect of TQ-PLGA-PVA nanoparticles (TQ-PLGA-PVA-NPs) on pulmonary fibrosis induced by bleomycin in albino rats. Forty male rats were randomized into four groups. The first group served as the control group; the second and the third groups received bleomycin intratracheally, whereas the third group received TQ-PLGA-PVA-NPs after 4 weeks from bleomycin administration. The fourth group was administrated TQ-PLGA-PVA-NPs alone. The designed nanoparticles appeared around 20 nm size (10&ndash;30 nm), had a spherical shape, and had 80% encapsulation efficiency. The histological examination of rats simultaneously treated with TQ-PLGA-PVA-NPs and bleomycin revealed reduction in the thickness of the alveolar septa and improvement of the other lung structures, with the presence of lymphocytes admixed with exfoliated epithelium in a few lumina remaining. Ultrastructural findings revealed marked collagenolysis and the release of nanoparticles from ruptured pneumocytes within the alveolar septa after 14 days from TQ-PLGA-PVA-NPs administration. Very active pneumocyte types II were seen in the TQ-PLGA-PVANP group. Additionally, immunohistochemical expression of inducible nitric oxide (iNOS) and estimation of inflammatory cytokines in lung tissues including interleukin 10 (IL 10) and transforming growth factor-beta (TGF-&beta;1) confirmed the antioxidant and anti-inflammatory effects of TQ-PLGA-PVANPs. The study concluded that TQ-PLGA-PVA-NPs could attenuate the bleomycin-induced pulmonary fibrosis, through the inhibition of lung inflammation and the suppression of bleomycin- induced oxidative stress

Lipid-lowering therapies for atherosclerosis: Statins, fibrates, ezetimibe and pcsk9 monoclonal antibodies

Cardiovascular disease (CVD) remains the primary cause of global morbidity and mortality. CVD includes various life-threatening conditions such as myocardial infarction, stroke and peripheral arterial diseases. In this context, atherosclerosis continues to play the principal role in the pathogenesis of these conditions. Atherosclerosis emanates from a set of modifiable and non-modifiable risk factors that include age, male gender, family history, obesity, smoking, diabetes mellitus and hypertension. Recent evidence classifies atherosclerosis as a latent disease affecting all-sized arteries with a predilection for arterial branching points of decreased or absent blood supply. Atherosclerosis is not only a lipid metabolism disorder, but is also a chronic inflammatory one. This review providesa synoptic discussion of the underlying pathological mechanisms of atherosclerosis andthe currently applied therapeutic interventions. We then discuss the classical lipid-lowering therapies as well as the newly discovered therapies. For the classical therapies, we point out the importance of statins and ezetimibe in reducing plasma cholesterol levels by virtue of their effects on synthesis, reuptake and intestinal absorption of cholesterol. We also discuss the role of fibrates in modulating lipid metabolism and improving the ratio of high-density to low-density density lipoproteins. This study focuseson the more recent molecular and genetic interventions exemplified by proprotein convertase subtilisin/kexin type 9 (PCSK9) monoclonal antibodies, evinacumab, and microRNA inhibitors. Special attention is also given to clinical trials involving these therapies