In this study, ultrasound assisted dispersive solid-phase micro extraction combined with spectrophotometry (USA-DSPME-UV) method based on activated carbon modified with Fe2O3 nanoparticles (Fe2O3-NPs-AC) was developed for pre-concentration and determination of safranin O (SO). It is known that the efficiency of USA-DSPME-UV method may be affected by pH, amount of adsorbent, ultrasound time and eluent volume and the extent and magnitude of their contribution on response (in term of main and interaction part) was studied by using central composite design (CCD) and artificial neural network-genetic algorithms (ANN-GA). Accordingly by adjustment of experimental conditions suggested by ANN-GA at pH 6.5, 1.1 mg of adsorbent, 10 min ultrasound and 150 μL of eluent volume led to achievement of best operation performance like low LOD (6.3 ng mL−1) and LOQ (17.5 ng mL−1) in the range of 25–3500 ng mL−1. In following stage, the SO content in real water and wastewater samples with recoveries between 93.27–99.41% with RSD lower than 3% was successfully determined.
Preparation and Evaluation of the Physicochemical and Antimicrobial Properties of Biological Nanostructures Polyolactic Acid / Calcium Oxide by Hydrothermal Assisted Microwave Method
Abstract Oxytetracycline (OTC) as the frequently applied antibiotics present in human and animal diets and its residue may results to various toxic effects. So, there is a crucial need for developing sensitive method for detection of OTC. Aptamer‐based biosensors (aptasensors) are frequently used in recent applied detection strategies with high affinity and specificity. In the present study, a colorimetric aptasensor was developed for detection of oxytetracycline (OTC) based on aggregation of aptamer functionalized AuNRs. The synthesized AuNRs were characterized and functionalized with specific DNA oligonucleotide as the aptamer to generate an optical signal after binding to the OTC antibiotic. The sensitivity of optical changes in spectroscopic analysis was improved under ambient temperature that resulted in aptamer folded structure and subsequent aggregation state of AuNRs. The longitudinal surface plasmon resonance (LSPR) of AuNRs was decreased in the linear range of applied OTC concentration from 0.1 nM to 100 nM with a detection limit of 0.04 nM. The proposed method was facile and showed sensitive and selective results, that would be consider as an alternative and efficient approach toward rapid detection of OTC.
In this work, we aimed to improve the antibacterial activity of sulfamethoxazole (SMX) via its inclusion in a newly synthesized nanocomposite composed of CuFe 2 O 4 nanoparticles and poly(vinyl alcohol)/silica‐based mesoporous materials. Characterization of this formulation using different techniques confirmed the correct synthesis and showed that this mesoporous nanocomposite had an amorphous structure with relatively high surface area of 1,620.7 m 2 g −1 and mean pore diameter of 1.6576 nm. Zeta potential of the formulation was obtained to be zero which led to its higher bioavailability in comparison to pure SMX with negative zeta potential. Antibacterial property of the prepared formulation against Staphylococcus aureus and Escherichia coli was evaluated. Minimum inhibitory concentration of the SMX‐loaded mesoporous nanocomposite was considerably lower than those of pure SMX, indicating the efficient function of the mesoporous material as a delivery system. Kinetics of SMX release was also studied using zero‐order, first‐order, Higuchi, and Korsmeyer–Peppas kinetics models. According to the obtained results, the release kinetics was found to obey zero‐order model. So the possibility of sustained release of SMX from the synthesized carrier may be suggested.
Drug use is common among people who live in prisons (PWLP) worldwide. This systematic review and meta-analysis aimed to summarize the prevalence of drug use among PWLP in Iran. We searched PubMed, Embase, Web of Science, Scopus, PsycINFO, as well as Farsi-language databases including Iran Psych Magiran, IranMedex, Scientific Information Database (SID), and Irandoc for studies published from January 2003 to January 2021. We included studies that reported the prevalence of drug use among PWLP. We performed a random-effects meta-analysis to pool prevalence estimates. Point estimates and 95% confidence intervals (CI) are reported. Among 1107 publications and reports screened, 16 studies reported the prevalence of drug use and were included. The pooled prevalence of lifetime non-injection drug use was 73.8% (95% CI 70.9, 76.6). The pooled prevalence of lifetime injection drug use was 16.0% (12.6, 19.7). Needle/syringe sharing among those with a lifetime injection drug use history was 14.0% (6.4, 24.0). Non-injection and injection drug use was found to be prevalent among PWLP in Iran. Continued evidence-based prevention, harm reduction, and treatment programs should address drug use among this population.
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