281 research outputs found

    A KINETIC ANAYSIS OF THE DEGRADATION OF GRAFTED ANIONIC POLYACRYLAMIDE GEL UNDER NONISOTHERMAL CONDITION

    Get PDF
    Grafted anionic polyacrylamide gel has been synthesised in the laboratory following radical polymerisation process. Kinetics of thermal degradation of synthesised gel was evaluated under nonisthothermal condition by integral approximation method to determine the thermal stability of the material from thermogavometric study. The activation energy for the thermal degradation was found to be significantly high for the gel material

    Tetralogy of Fallot: Imaging of common and uncommon associations by multidetector CT

    Get PDF
    AbstractPurposeTo demonstrate the superior role of multidetector computed tomography (MDCT) in delineation of the extracardiac vascular abnormalities including the pulmonary arterial tree, major aortopulmonary collateral arteries (MAPCAs), patent ductus arteriosus (PDA), and also the detection of the common and uncommon findings in Fallot Tetralogy cases for proper pre-surgical evaluation.Material and methodsA retrospective study of all multidetector CT images acquired to evaluate suspected cases of Tetralogy of Fallot sent by their respective referring physicians between April 2009 and August 2010. A total of 23 cases were included in this study. MDCT protocol, image analysis and calculations used in the diagnosis are explained in detail.ResultsDetailed explanation of the MDCT imaging findings in the 23 cases with Tetralogy of Fallot, as well as the common and uncommon associations of the disease, namely pulmonary atresia, MAPCAs, PDAs, atrial septal defects (ASDs), right sided aortic arch, and a few less common associations.ConclusionA customized approach to MDCT imaging improves the diagnostic accuracy and reduces unneeded prolongation of the study and sedation times. A careful preoperative perceptive of the complex cardiovascular anatomy in patients with Tetralogy of Fallot aids in exposing the patient to a directed and prepared surgical approach

    Does therapeutic plasma exchange have a role in resistant cytokine storm state of COVID-19 infection?

    Get PDF
    Introduction: Among the main causes of mortality in COVID-19 patients is cytokine storm (CS) state. Few treatment options with variable efficacy results are available for its management. We aimed to illustrate the efficacy of Therapeutic Plasma Exchange (TPE) treatment in COVID-19 patients with resistant CS.Material and methods: This research is a prospective pilot study which included ten COVID-19 positive patients with CS state with no response after two doses of tocilizumab. Each patient received three to five TPE sessions according to his/her response. Respiratory status {oxygen (O2) requirements and data of mechanical ventilation} and laboratory markers (IL-6, CRP, ferritin, D dimer, LDH) were assessed before and after TPE. We reported mortality at 28 day of illness.Results: Six males and four females were enrolled in the study with a mean age of (52.9 years). Seven patients (70%) were on mechanical ventilation (MV). After TPE, oxygenation parameters and most laboratory markers improved significantly in all patients (p < 0.05). Four patients survived and were discharged (40%). One was on MV and three were not. The four patients had better hypoxic index (PaO2/FiO2 ratio) (˃100 vs <100), started TPE sooner after tocilizumab failure (2–3 vs 5–6 days), needed fewer TPE sessions (3 vs 4–5, p = 0.03), and less duration in ICU (6.5 vs 12.5 days) compared to those who did not benefit.Conclusions: In patients with CS state who did not respond well to tocilizumab and steroids, TPE could be a good option. Larger randomized clinical trials are needed to support its use.Clinical trials registration: ClinicalTrials.gov Identifier:NCT0445734

    Post-Mastectomy Shoulder Pain and Lymphedema Responses to Ga-As Laser Versus Microcurrent Electrical Stimulation

    Get PDF
    Objective: to evaluate the efficacy of GA-AS laser against microcurrent electrical stimulation on postmastectomy shoulder pain as well as lymphedema. Method: a double blinded randomized controlled study. sixty breast cancer patients with lymph-edema stage I and II ,40-55 years old were assigned randomly into study -group A, n = 20 or study -group B, (n = 20) in addition to control group C, (n = 20). The study group was given 20 minutes GA-AS laser, 90 minutes complete decongestive therapy (CDT). study -group B received 20 minutes of microcurrent electrical stimulation (MENS) and 90minutes CDT, control group C was given 90 minutes CDT. All treatment interventions were applied at a frequency of three sessions per week for 12 weeks. Arm volume calculated by circumference measurement, Shoulder and Hand (DASH) questionnaire as well as pain intensity utilizing a visual analogue scale (VAS) were measured at before and following 12 weeks of treatment. Results: a statistically significant difference has been detected in limb volume, DASH questionnaire as well as VAS favoring the study group A ((p = 0.001).) and the study group B ((p = 0.001). following 12 weeks of intervention. The mean (SD) for limb-volume, DASH questionnaire as well as pain score were 1236.74 ± 43.34, 27.21 ± 7.16, and 3.20 ± 0.62in the study group A, and 1331.76 ± 46.92, 34.52 ± 4.38 and 3.90 ± 0.78in the study group B and 1390.18 ± 58.77 ml, 40.68 ± 6.93and 5.30 ± 0.86in the control group C respectively. Conclusion: adding GA-AS laser and microcurrent electrical stimulation to the conventional physical therapy program had a valuable effect than traditional physical therapy program alone in improving postmastectomy shoulder pain as well as lymphedema

    Moving object tracking in clinical scenarios: application to cardiac surgery and cerebral aneurysm clipping.

    Get PDF
    BACKGROUND AND OBJECTIVES: Surgical procedures such as laparoscopic and robotic surgeries are popular since they are invasive in nature and use miniaturized surgical instruments for small incisions. Tracking of the instruments (graspers, needle drivers) and field of view from the stereoscopic camera during surgery could further help the surgeons to remain focussed and reduce the probability of committing any mistakes. Tracking is usually preferred in computerized video surveillance, traffic monitoring, military surveillance system, and vehicle navigation. Despite the numerous efforts over the last few years, object tracking still remains an open research problem, mainly due to motion blur, image noise, lack of image texture, and occlusion. Most of the existing object tracking methods are time-consuming and less accurate when the input video contains high volume of information and more number of instruments. METHODS:This paper presents a variational framework to track the motion of moving objects in surgery videos. The key contributions are as follows: (1) A denoising method using stochastic resonance in maximal overlap discrete wavelet transform is proposed and (2) a robust energy functional based on Bhattacharyya coefficient to match the target region in the first frame of the input sequence with the subsequent frames using a similarity metric is developed. A modified affine transformation-based registration is used to estimate the motion of the features following an active contour-based segmentation method to converge the contour resulted from the registration process. RESULTS AND CONCLUSION:The proposed method has been implemented on publicly available databases; the results are found satisfactory. Overlap index (OI) is used to evaluate the tracking performance, and the maximum OI is found to be 76% and 88% on private data and public data sequences

    A Miniaturized and Highly Sensitive Microwave Sensor Based on CSRR for Characterization of Liquid Materials

    Get PDF
    In this work, a miniaturized and highly sensitive microwave sensor based on a complementary split-ring resonator (CSRR) is proposed for the detection of liquid materials. The modeled sensor was designed based on the CSRR structure with triple rings (TRs) and a curve feed for improved measurement sensitivity. The designed sensor oscillates at a single frequency of 2.5 GHz, which is simulated using an Ansys HFSS simulator. The electromagnetic simulation explains the basis of the mode resonance of all two-port resonators. Five variations of the liquid media under tests (MUTs) are simulated and measured. These liquid MUTs are as follows: without a sample (without a tube), air (empty tube), ethanol, methanol, and distilled water (DI). A detailed sensitivity calculation is performed for the resonance band at 2.5 GHz. The MUTs mechanism is performed with a polypropylene tube (PP). The samples of dielectric material are filled into PP tube channels and loaded into the CSRR center hole; the E-fields around the sensor affect the relationship with the liquid MUTs, resulting in a high Q-factor value. The final sensor has a Q-factor value and sensitivity of 520 and 7.032 (MHz)/Er) at 2.5 GHz, respectively. Due to the high sensitivity of the presented sensor for characterizing various liquid penetrations, the sensor is also of interest for accurate estimations of solute concentrations in liquid media. Finally, the relationship between the permittivity and Q-factor value at the resonant frequency is derived and investigated. These given results make the presented resonator ideal for the characterization of liquid materials.Publicad

    Review of recent microwave planar resonator-based sensors: Techniques of complex permittivity extraction, applications, open challenges and future research directions

    Get PDF
    Recent developments in the field of microwave planar sensors have led to a renewed interest in industrial, chemical, biological and medical applications that are capable of performing real-time and non-invasive measurement of material properties. Among the plausible advantages of microwave planar sensors is that they have a compact size, a low cost and the ease of fabrication and integration compared to prevailing sensors. However, some of their main drawbacks can be considered that restrict their usage and limit the range of applications such as their sensitivity and selectivity. The development of high-sensitivity microwave planar sensors is required for highly accurate complex permittivity measurements to monitor the small variations among different material samples. Therefore, the purpose of this paper is to review recent research on the development of microwave planar sensors and further challenges of their sensitivity and selectivity. Furthermore, the techniques of the complex permittivity extraction (real and imaginary parts) are discussed based on the different approaches of mathematical models. The outcomes of this review may facilitate improvements of and an alternative solution for the enhancement of microwave planar sensors’ normalized sensitivity for material characterization, especially in biochemical and beverage industry applications

    Super compact UWB monopole antenna for small IoT devices

    Get PDF
    This article introduces a novel, ultrawideband (UWB) planar monopole antenna printed on Roger RT/5880 substrate in a compact size for small Internet of Things (IoT) applications. The total electrical dimensions of the proposed compact UWB antenna are 0.19 λo × 0.215 λo × 0.0196 λo with the overall physical sizes of 15 mm × 17 mm × 1.548 mm at the lower resonance frequency of 3.8 GHz. The planar monopole antenna is fed through the linearly tapered microstrip line on a partially structured ground plane to achieve optimum impedance matching for UWB operation. The proposed compact UWB antenna has an operation bandwidth of 9.53 GHz from 3.026 GHz up to 12.556 GHz at -10 dB return loss with a fractional bandwidth (FBW) of about 122%. The numerically computed and experimentally measured results agree well in between. A detailed time-domain analysis is additionally accomplished to verify the radiation efficiency of the proposed antenna design for the ultra-wideband signal propagation. The fabricated prototype of a compact UWB antenna exhibits an omnidirectional radiation pattern with the low peak measured gain required of 2.55 dBi at 10 GHz and promising radiation efficiency of 90%. The proposed compact planar antenna has technical potential to be utilized in UWB and IoT applications

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

    Get PDF
    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
    corecore