18 research outputs found
Investigation of the JPA-Bandwidth Improvement in the Performance of the QTMS Radar
Josephson parametric amplifier (JPA) engineering is a significant component in the quantum two-mode squeezed radar (QTMS) to enhance, for instance, radar performance and the detection range or bandwidth. We simulated a proposal of using engineered JPA (EJPA) to enhance the performance of a QTMS radar. We defined the signal-to-noise ratio (SNR) and detection range equations of the QTMS radar. The engineered JPA led to a remarkable improvement in the quantum radar performance, i.e., a large enhancement in SNR of about 6 dB more than the conventional QTMS radar (with respect to the latest version of the QTMS radar and not to the classical radar), a substantial improvement in the probability of detection through far fewer channels. The important point in this work was that we expressed the importance of choosing suitable detectors for the QTMS radars. Finally, we simulated the transmission of the signal to the target in the QTMS radar and obtained a huge increase in the QTMS radar range, up to 482 m in the current study
Sensor Fault Detection and Compensation with Performance Prescription for Robotic Manipulators
This paper focuses on sensor fault detection and compensation for robotic
manipulators. The proposed method features a new adaptive observer and a new
terminal sliding mode control law established on a second-order integral
sliding surface. The method enables sensor fault detection without the need to
impose known bounds on fault value and/or its derivative. It also enables fast
and fixed-time fault-tolerant control whose performance can be prescribed
beforehand by defining funnel bounds on the tracking error. The ultimate
boundedness of the estimation errors for the proposed observer and the
fixed-time stability of the control system are shown using Lyapunov stability
analysis. The effectiveness of the proposed method is verified using numerical
simulations on two different robotic manipulators, and the results are compared
with existing methods. Our results demonstrate performance gains obtained by
the proposed method compared to the existing results
Effects of dietary Thymus Vulgaris essential oil on the liver in mice
Introduction: Thymus vulgaris (thyme) is commonly used in folk medicine for several therapeutic purposes. The aim of this study was to evaluate the effects of peritoneal injection of essential oil of thymus vulgaris on the liver as an organ involved in metabolism. It also examines toxic effects following a high dose of the drug.
Methods and Results: Twenty-four mice were divided randomly into three groups. Group 1 was the control group without treatment, group 2 has received a dose of thyme essential oil, 0.4 mg/kg intraperitonealy for 10 days and group 3 has received a dose of thyme essential oil, 0.6 mg/kg intraperitonealy for 10 days. A score of liver damage severity was semi-quantitatively assessed using the modified Histological Activity Index ‘(modified HAI). Statistical analysis was performed by using computer program SPSS (19). The results showed the statistically significant increase (P≤ 0.05) in the histopathological scoring in Group2 when compared with Group1.
Conclusions: The histopathological examination of control group reveals normal hepatic tissue, no portal or periportal inflammation, necrosis, congestion, Infiltration of WBC and fibrosis. While there was a significant loss in hepatic architecture in Group 2 which showed portal inflammation with periportal interface hepatitis (piecemeal necrosis) centrilobular necrosis, congestion, infiltration of WBC and bridging necrosis. The results were revealed statistically significant increase (P≤ 0.05) in the histopathological scoring in Group3 when compared with Group2. The histopathological examination of thyme treated group (Gp3) showed significant toxic effects with moderate acute inflammation of mononuclear cells. It has been determined that Thymus vulgaris (thyme) leads to histological damage including portal inflammation with centrilobular necrosis. The histological alterations may occur through oxidative properties
A Comparative Analysis of Clinical Characteristics and Laboratory Findings of COVID-19 between Intensive Care Unit and Non-Intensive Care Unit Pediatric Patients: A Multicenter, Retrospective, Observational Study from Iranian Network for Research in Viral
Introduction: To date, little is known about the clinical features of pediatric COVID-19 patients admitted to intensive care units (ICUs). Objective: Herein, we aimed to describe the differences in demographic characteristics, laboratory findings, clinical presentations, and outcomes of Iranian pediatric COVID-19 patients admitted to ICU versus those in non-ICU settings. Methods: This multicenter investigation involved 15 general and pediatrics hospitals and included cases with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection based on positive real-time reverse transcription polymerase chain reaction (RT-PCR) admitted to these centers between March and May 2020, during the initial peak of the COVID-19 pandemic in Iran. Results: Overall, 166 patients were included, 61 (36.7%) of whom required ICU admission. The highest number of admitted cases to ICU were in the age group of 1–5 years old. Malignancy and heart diseases were the most frequent underlying conditions. Dyspnea was the major symptom for ICU-admitted patients. There were significant decreases in PH, HCO3 and base excess, as well as increases in creatinine, creatine phosphokinase (CPK), lactate dehydrogenase (LDH), and potassium levels between ICU-admitted and non-ICU patients. Acute respiratory distress syndrome (ARDS), shock, and acute cardiac injury were the most common features among ICU-admitted patients. The mortality rate in the ICU-admitted patients was substantially higher than non-ICU cases (45.9% vs. 1.9%, respectively; p<0.001). Conclusions: Underlying diseases were the major risk factors for the increased ICU admissions and mortality rates in pediatric COVID-19 patients. There were few paraclinical parameters that could differentiate between pediatrics in terms of prognosis and serious outcomes of COVID-19. Healthcare providers should consider children as a high-risk group, especially those with underlying medical conditions
Symptomatology and microbiology of the gastrointestinal tract in post‐COVID conditions
Post-COVID conditions, also known as post-acute sequelae of SARS-CoV-2 (PASC), refer to the persistence of symptoms in COVID-19 long-haulers. Various manifestations of post-COVID conditions are general symptoms and/or manifestations of damage in multiple organs. Besides, SARS-CoV-2 can involve the gastrointestinal tract, resulting in sequelae such as diarrhea, abdominal pain, nausea, anorexia, vomiting, constipation, abdominal distension, acid reflux, and/or gastrointestinal bleeding. Previous investigations point to SARS-CoV-2 entry into enterocytes enhances by the angiotensin-converting enzyme 2 (ACE2) receptors. Interestingly, ACE2 receptors are abundantly expressed in the gut, implying infection with SARS-CoV-2 might occur through this route as well as in the respiratory tract. According to mounting evidence, SARS-CoV-2 RNA has been identified in fecal specimens of patients with COVID-19 during and beyond the acute phase. In addition, studies have shown gut microbiome composition is altered in patients with PASC, hence, another putative mechanism linked to gastrointestinal symptoms is gut dysbiosis. The presence of the gut-lung axis in COVID-19 might have major implications for disease pathogenesis and treatment. This review discussed the prevalence of gastrointestinal symptoms and pathophysiology underlying possible infection of the gut in patients with PASC. Also, SARSCOV-2 induced NLRP3 inflammasome-dependent inflammatory pathways are briefly addressed
Quantum teleportation in Heisenberg chain with magnetic-field gradient under intrinsic decoherence
One of the most appealing quantum communication protocols is quantum teleportation, which
involves sharing entanglement between the sender and receiver of the quantum state. We address the
two-qubit quantum teleportation based on the Heisenberg XYZ chain with a magnetic-field gradient
affected by intrinsic decoherence. An atomic spin chain is primarily coupled to the linear gradient
of the magnetic field in the x-direction, with the assumption that the magnetic field varies linearly
with the position of the atom. By using the concepts of fidelity and average fidelity in the presence
of the magnetic field gradient and under the effect of intrinsic decoherence in the current model,
and considering the variables of the system, an improved quantum teleportation can be achieved. In
addition, using the concept of remote quantum estimation, we examine remote quantum sensing in
this article, which is very useful in quantum communication