Fabrication of paper-based analytical devices optimized by central composite design

In this work, an application of a design of experiments approach for the optimization of an isoniazid assay on a single-area inkjet-printed paper-based analytical device (PAD) is described. For this purpose, a central composite design was used for evaluation of the effect of device geometry and amount of assay reagents on the efficiency of the proposed device. The factors of interest were printed length, width, and sampling volume as factors related to device geometry, and amounts of the assay reagents polyvinyl alcohol (PVA), NH 4 OH, and AgNO 3 . Deposition of the assay reagents was performed by a thermal inkjet printer. The colorimetric assay mechanism of this device is based on the chemical interaction of isoniazid, ammonium hydroxide, and PVA with silver ions to induce the formation of yellow silver nanoparticles (AgNPs). The in situ-formed AgNPs can be easily detected by the naked eye or with a simple flat-bed scanner. Under optimal conditions, the calibration curve was linear in the isoniazid concentration range 0.03-10 mmol L -1 with a relative standard deviation of 3.4% (n = 5 for determination of 1.0 mmol L -1 ). Finally, the application of the proposed device for isoniazid determination in pharmaceutical preparations produced satisfactory results

Real life management of chronic urticaria: Multicenter and cross sectional study on patients and dermatologists in Iran

Recently, advances in understanding the etiology of urticaria and updates of diagnostic and therapeutic management guidelines have drawn attention to chronic urticaria (CU) morbidity. The present study aimed to evaluate Iranian dermatologists' practice and real life management of CU patients. A total of 35 dermatologists and 443 patients were included in the study. Number of female patients was 321 (72.5). Mean (standard deviation) age of the study patients was 38 (13) years and the median (inter quartile range) of disease duration was 12 (6�48) months. Severity of patients' symptoms was mild for 32.1, moderate for 38.7, severe for 18.8, and 10.4 of them had no evident signs or symptoms. The most common diagnostic methods were physical examination (96.6), differential blood count (83.5), erythrocyte sedimentation rate (77.4), and C-reactive protein (62.8). The number of dermatologists prescribed nonsedating antihistamines (nsAH) in regular dose and high dose mono therapy were 26 (74) and 6 (17), respectively. About 66 of dermatologists were familiar with British Association of Dermatologists (BAD) guideline. The most common first-line treatment for CU by Iranian dermatologists was nonsedating antihistamines in regular or high doses. The real-life management of patients with CU in Iran was in accordance with the available practice guidelines. © 2018 Wiley Periodicals, Inc