Corrosion Inhibition of Mild Steel by Safflower (Carthamus tinctorius) Extract: Polarization,EIS, AFM,SEM, EDS,and Artificial Neural Network Modeling

Inhibitory action of safflower (Carthamus tinctorius) extract (SE) was investigated in hydrochloric acid solution through electrochemical (polarization, EIS), and surface analysis (optical microscopy/atomic force microscopy (AFM)/scanning electron microscopy (SEM)/energy dispersive spectroscopy (EDS)) techniques. In addition, Inhibition efficiency was predicted by neural network (NN) modeling in elevated temperatures and different acid concentrations. The thermodynamic adsorption parameters propose that this inhibitor retard both cathodic and anodic processes through physical adsorption and blocking the active corrosion sites. Surface analysis techniques confirm the inhibitor adsorption on the metal surface, which is in accordance with the variation of apparent activation energy of corrosion. Finally, inhibition efficiency is discussed in terms of protective film formation.     

Synthesis of benzofurazan derivatization reagents for carboxylic acids in liquid chromatography/electrospray ionization-tandem mass spectrometry

The applicability of benzofurazan derivatization regents to carboxylic acids analysis in LC/ESI-MS/MS (high-performance liquid chromatography/electrospray ionization tandem mass spectrometry) was examined. The product ion spectra of DAABD-AE {4-[2-(N,N-dimethylamino)ethylaminosulfonyl]-7-(2-aminoethylamino)-2,1,3-benzoxadiazole}, DAABD-PZ {4-[2-(N,N-dimethylamino)ethylaminosulfonyl]-7-N-piperazino-2,1,3-benzoxadiazole}, DAABD-PiCZ {4-[4-carbazoylpiperidin-1-yl]-7-[2-(N,N-dimethylamino)ethylaminosulfonyl]-2,1,3-benzoxadiazole}, DAABD-ProCZ {4-[2-carbazoylpyrrolidin-1-yl]-7-[2-(N,N-dimethylamino) ethylaminosulfonyl]-2,1,3-benzoxadiazole} and DAABD-Apy {4-[2-(N,N-dimethylamino)ethylaminosulfonyl]-7-(3-aminopyrrolidin-1-yl)-2,1,3-benzoxadiazole}, and their acetylated compounds were obtained. An intense fragment ion at m/z 151 corresponding to (dimethylamino)ethylaminosulfonyl moiety was observed in each spectra, suggesting that these reagents were suitable for ESI-MS/MS analysis. DAABD-AE, DAABD-APy and DAABD-PZ were applied to the analysis of octanoic acid and it was found that DAABD-AE and DAABD-APy gave high signal intensity suitable for LC/ESI-MS/MS.     

Antifungal Properties of Essential Oils and Their Compounds for Application in Skin Fungal Infections: Conventional and Nonconventional Approaches

Essential oils (EOs) are known to have varying degrees of antimicrobial properties that are mainly due to the presence of bioactive compounds. These include antiviral, nematicidal, antifungal, insecticidal and antioxidant properties. This review highlights the potential of EOs and their compounds for application as antifungal agents for the treatment of skin diseases via conventional and nonconventional approaches. A search was conducted using three databases (Scopus, Web of Science, Google Scholar), and all relevant articles from the period of 2010–2020 that are freely available in English were extracted. In our findings, EOs with a high percentage of monoterpenes showed strong ability as potential antifungal agents. Lavandula sp., Salvia sp., Thymus sp., Citrus sp., and Cymbopogon sp. were among the various species found to show excellent antifungal properties against various skin diseases. Some researchers developed advanced formulations such as gel, semi-solid, and ointment bases to further evaluate the effectiveness of EOs as antifungal agents. To date, most studies on the application of EOs as antifungal agents were performed using in vitro techniques, and only a limited number pursued in vivo and intervention-based research.     

UPLC-MS/MS determination of doxazosine in human plasma

A sensitive, selective and rapid method for the analysis of doxazosine (DOX) in human plasma based on ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) is described. DOX and tamsulosin, used as an internal standard (IS), were extracted by liquid-liquid extraction, and the chromatography was performed on a C18 UPLC column packed with 1.7 μm particles. The total run time was 2 min. Detection was achieved by the multiple reaction monitoring of the following transitions: m/z 452→344 and m/z 409→228 for DOX and IS, respectively. Transitions of m/z 452→247 and m/z 409→271 were also collected for confirmation purposes. The calibration curve based on peak area ratio was linear up to at least 100 ng ml⁻¹, with a detection limit of 0.02 ng ml⁻¹ (a signal-to-noise ratio of 3). The method showed satisfactory reproducibility, and the short-term stability of the analyte was assessed. The method was successfully applied to the analysis of DOX in human plasma.     

Radioiodinated paroxetine, a novel potential radiopharmaceutical for lung perfusion scan

Paroxetine (a selective serotonin reuptake inhibitor) was successfully labeled with ¹²⁵I via direct electrophilic substitution reaction at ambient temperature. The reaction parameters studied were paroxetine amount, CAT amount, pH of the reaction mixture, reaction temperature, reaction time and in vitro stability of ¹²⁵I-paroxetine. ¹²⁵I-paroxetine was obtained with a maximum labeling yield of 94 ± 0.23% and in vitro stability up to 24 h. Biodistribution studies showed that maximum in vivo uptake of ¹²⁵I-paroxetine in lungs was 27.89 ± 1.03% injected activity/g tissue at 15 min post-injection and retention in lungs remained high up to 1 h, whereas the clearance from mice appeared to proceed mainly via the hepatobiliary pathway. ¹²⁵I-paroxetine is not a blood product and so it is more safe than the currently available ^99mTc-macroaggregated albumin (^99mTc-MAA), and its lung uptake is higher than that of the recently discovered ^99mTc(CO)₅I and ^99mTc-DHPM. As a conclusion, radioiodinated paroxetine could be used as a novel radiopharmaceutical for lung perfusion scan safer than the currently available ^99mTc-MAA and more potential than the recently discovered ^99mTc(CO)₅I and ^99mTc-DHPM.     

Acetals of Dehydro-L-Ascorbic Acid 2-Hydrazones. Access to the Chiral Building Block (R)-Glycerol Acetonide

5,6-O-Isopropylidene, cyclohexylidene and benzylidene derivatives of L-threo-2,3-hexodiulosono-1,4-lactone 2-phenylhydrazone were prepared. Reduction of the isopropylidcne derivative was followed by treatment with base, and then periodate oxidation and reduction to give (R)-glycerol acetonide. Hydrogen bonding in the hydrazones has a role in forming geometrical isomers.     

Application of PMR Spectroscopy in Pharmaceutical Analysis Assay of Furosemide

An analytical method is described for the analysis of furosemide, [4-chloro-2-furfurylamino-5-sulfamoylbenzoic acid], using PMR. The procedure reported in this study is simple, rapid and gives accurate results 98.19 ± 1.34% and 99.23 ± 0.88% for furosemide ampoules and tablets respectively. Furthermore, the PMR spectrum obtained provides a mean for qualitative identification of the drug and checking its purity.     

Operation performance characteristics of vertical-cavity surface-emitting lasers (VCSELs) under high thermal neutron irradiated fields

To operate and read out even the innermost detectors under any particular conditions, electronics and optical components must be developed accordingly. For semiconductor lasers, on which we will concentrate here, it has been found that an inner temperature increase has a direct impact on the light power emitted by the device. It was found that the effects of radiation on the behavior of semiconductor lasers are convolved with those of temperature. An optimized coupling to the cooling of the laser device reduces the thermal effects in the material. Therefore, a test stand to qualify the effect of heat in the device and the adoption of the heat sink is realized. In this paper, we create a model describing the degradation of the light power and voltage characteristic of a semiconductor-laser undergoing irradiation where the high temperature effects are taken into account. This VCSEL-device model can be used to predict the behavior and operation-performance characteristics (rise time, 3 dB bandwidth, light power, resonance frequency, and transmission bit rate) of a laser being irradiated with different neutron doses. We check the robustness of the model against the high fluence (in excess of 10¹⁵ neutrons/cm²). We take into account the study of different semiconductor- and polymeric material-based VCSEL devices such as aluminum gallium arsenide (AlGaAs), indium gallium arsenide phosphors (InGaAsP), and polymeric polymethylmethacrylate (PMMA) under the same operating conditions.