Fabrication of polyaniline/TiO2 nanocomposite ammonia vapor sensor

Polyaniline/Titanium dioxide (PANi/TiO2) nanocomposite was fabricated from PANi, prepared by oxidative chemical polymerization and TiO2, synthesized by sol gel method. The PANi/TiO2 thin film sensors were prepared by spin coating technique. PANi/TiO2 nanocomposites were characterized by XRD and SEM. The cross sensitivity of thin film sensor indicate that the sensor exhibit selectivity to ammonia (NH3). The gas sensing measurements were carried out for different concentrations of NH3. The gas sensing study revealed that the response value increases with increasing concentration of NH3. Moreover, as concentration of NH3 increases, the response time decreases while recovery time increases, which can be attributed to the varying adsorption and desorption rates of an ambient gas with increasing concentration. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2791

Fabrication of polyaniline/TiO2 nanocomposite ammonia vapor sensor

Polyaniline/Titanium dioxide (PANi/TiO2) nanocomposite was fabricated from PANi, prepared by oxidative chemical polymerization and TiO2, synthesized by sol gel method. The PANi/TiO2 thin film sensors were prepared by spin coating technique. PANi/TiO2 nanocomposites were characterized by XRD and SEM. The cross sensitivity of thin film sensor indicate that the sensor exhibit selectivity to ammonia (NH3). The gas sensing measurements were carried out for different concentrations of NH3. The gas sensing study revealed that the response value increases with increasing concentration of NH3. Moreover, as concentration of NH3 increases, the response time decreases while recovery time increases, which can be attributed to the varying adsorption and desorption rates of an ambient gas with increasing concentration. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2791

Effect Of Annealing On Structure, Morphology, Electrical And Optical Properties Of Nanocrystalline TiO2 Thin Films

Semi-transparent and highly conducting nanostructured titanium oxide thin films have been prepared by sol-gel method. Thin films of TiO2 deposited on glass substrates using spin coating technique and the effect of annealing temperature (400 - 700 °C) on structural, microstructural, electrical and optical properties were studied. The X-ray diffraction and Atomic force microscopy measurements confirmed that the films grown by this technique have good crystalline tetragonal mixed anatase and rutile phase structure and homogeneous surface. The study also reveals that the rms value of thin film roughness increases from 7 to 19 nm. HRTEM image of TiO2 thin film (annealed at 700 °C) shows that a grain of about 50 - 60 nm in size is really aggregate of many small crystallites of around 10 - 15 nm. Electron diffraction pattern shows that the TiO2 films exhibited tetragonal structure. The surface morphology (SEM) of the TiO2 film showed that the nanoparticles are fine with an average grain size of about 50 - 60 nm. The optical band gap slightly decreases from 3.26 - 3.24 eV and the dc electrical conductivity was found in the range of 10-6 to 10-5(Ω·cm)-1 when the annealing temperature is changed from 400 to 700 °C. It is observed that TiO2 thin film annealed at 700 °C after deposition provide a smooth and flat texture suited for optoelectronic applications. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/967

The international EAACI/GA²LEN/EuroGuiDerm/APAAACI guideline for the definition, classification, diagnosis, and management of urticaria

This update and revision of the international guideline for urticaria was developed following the methods recommended by Cochrane and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) working group. It is a joint initiative of the Dermatology Section of the European Academy of Allergology and Clinical Immunology (EAACI), the Global Allergy and Asthma European Network (GA²LEN) and its Urticaria and Angioedema Centers of Reference and Excellence (UCAREs and ACAREs), the European Dermatology Forum (EDF; EuroGuiDerm), and the Asia Pacific Association of Allergy, Asthma and Clinical Immunology with the participation of 64 delegates of 50 national and international societies and from 31 countries. The consensus conference was held on 3 December 2020. This guideline was acknowledged and accepted by the European Union of Medical Specialists (UEMS). Urticaria is a frequent, mast cell–driven disease that presents with wheals, angioedema, or both. The lifetime prevalence for acute urticaria is approximately 20%. Chronic spontaneous or inducible urticaria is disabling, impairs quality of life, and affects performance at work and school. This updated version of the international guideline for urticaria covers the definition and classification of urticaria and outlines expert-guided and evidence-based diagnostic and therapeutic approaches for the different subtypes of urticaria. © 2021 GA²LEN. Allergy published by European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd

The global impact of the COVID-19 pandemic on the management and course of chronic urticaria

Introduction: The COVID-19 pandemic dramatically disrupts health care around the globe. The impact of the pandemic on chronic urticaria (CU) and its management are largely unknown. Aim: To understand how CU patients are affected by the COVID-19 pandemic; how specialists alter CU patient management; and the course of CU in patients with COVID-19. Materials and Methods: Our cross-sectional, international, questionnaire-based, multicenter UCARE COVID-CU study assessed the impact of the pandemic on patient consultations, remote treatment, changes in medications, and clinical consequences. Results: The COVID-19 pandemic severely impairs CU patient care, with less than 50% of the weekly numbers of patients treated as compared to before the pandemic. Reduced patient referrals and clinic hours were the major reasons. Almost half of responding UCARE physicians were involved in COVID-19 patient care, which negatively impacted on the care of urticaria patients. The rate of face-to-face consultations decreased by 62%, from 90% to less than half, whereas the rate of remote consultations increased by more than 600%, from one in 10 to more than two thirds. Cyclosporine and systemic corticosteroids, but not antihistamines or omalizumab, are used less during the pandemic. CU does not affect the course of COVID-19, but COVID-19 results in CU exacerbation in one of three patients, with higher rates in patients with severe COVID-19. Conclusions: The COVID-19 pandemic brings major changes and challenges for CU patients and their physicians. The long-term consequences of these changes, especially the increased use of remote consultations, require careful evaluation. © 2020 The Authors. Allergy published by European Academy of Allergy and Clinical Immunology and John Wiley & Sons Lt

Urticaria exacerbations and adverse reactions in patients with chronic urticaria receiving COVID-19 vaccination : results of the UCARE COVAC-CU study

Background: Concern about disease exacerbations and fear of reactions after coronavirus disease 2019 (COVID-19) vaccinations are common in chronic urticaria (CU) patients and may lead to vaccine hesitancy. Objective: We assessed the frequency and risk factors of CU exacerbation and adverse reactions in CU patients after COVID-19 vaccination. Methods: COVAC-CU is an international multicenter study of Urticaria Centers of Reference and Excellence (UCAREs) that retrospectively evaluated the effects of COVID-19 vaccination in CU patients aged ≥18 years and vaccinated with ≥1 dose of any COVID-19 vaccine. We evaluated CU exacerbations and severe allergic reactions as well as other adverse events associated with COVID-19 vaccinations and their association with various CU parameters. Results: Across 2769 COVID-19–vaccinated CU patients, most (90%) received at least 2 COVID-19 vaccine doses, and most patients received CU treatment and had well-controlled disease. The rate of COVID-19 vaccination–induced CU exacerbation was 9%. Of 223 patients with CU exacerbation after the first dose, 53.4% experienced recurrence of CU exacerbation after the second dose. CU exacerbation most often started <48 hours after vaccination (59.2%), lasted for a few weeks or less (70%), and was treated mainly with antihistamines (70.3%). Factors that increased the risk for COVID-19 vaccination–induced CU exacerbation included female sex, disease duration shorter than 24 months, having chronic spontaneous versus inducible urticaria, receipt of adenovirus viral vector vaccine, having nonsteroidal anti-inflammatory drug/aspirin intolerance, and having concerns about getting vaccinated; receiving omalizumab treatment and Latino/Hispanic ethnicity lowered the risk. First-dose vaccine–related adverse effects, most commonly local reactions, fever, fatigue, and muscle pain, were reported by 43.5% of CU patients. Seven patients reported severe allergic reactions. Conclusions: COVID-19 vaccination leads to disease exacerbation in only a small number of CU patients and is generally well tolerated