A Study on Solubilization of Poorly Soluble Drugs by Cyclodextrins and Micelles: Complexation and Binding Characteristics of Sulfamethoxazole and Trimethoprim

The present study is focused on the characterization of solubilization of poorly soluble drugs, that is, sulfamethoxazole (SMX) and trimethoprim (TMP) by cyclodextrins (α-, β-, and γ-CDs) and anionic surfactant sodium dodecyl sulfate (SDS). The phase solubility diagrams drawn from UV spectral measurements are of the AL type and indicate an enhancement of SMX and TMP solubility in the presence of CDs. Complex formation tendency of TMP with CDs followed the order: γ-CD > β-CD > α-C. However, the complex formation constant values, for SMX-CD system yielded the different affinity and follow the order: β-CD > γ-CD > α-CD. With taking into consideration of solubilization capacity of SDS micelles, it has been found that the solubility enhancement of TMP is much higher than that of SMX in the presence of SDS micelles. The binding constants of SMX and TMP obtained from the Benesi-Hildebrand equation are also confirmed by the estimated surface properties of SDS, employing the surface tension measurements. In order to elucidate the solubilization characteristics the surface tension measurements were also performed for nonionic surfactant Triton X-100. Polarity of the microenvironment and probable location of SMX and TMP were also discussed in the presence of various organic solvents

Performative Work: Bridging Performativity and Institutional Theory in the Responsible Investment Field

Callon’s performativity thesis has illuminated how economic theories and calculative devices shape markets, but has been challenged for its neglect of the organizational, institutional and political context. Our seven-year qualitative study of a large financial data company found that the company’s initial attempt to change the responsible investment field through a performative approach failed because of the constraints posed by field practices and organizational norms on the design of the calculative device. However, the company was subsequently able to put in place another form of performativity by attending to the normative and regulative associations of the device. We theorize this route to performativity by proposing the concept of performative work, which designates the necessary institutional work to enable translation and the subsequent adoption of the device. We conclude by considering the implications of performative work for the performativity and the institutional work literatures

Composing Urban Orders from Rubbish Electronics: Cityness and the Site Multiple

What do cities look like when rubbish electronics are the vehicle with which they are explored? This article is an experiment designed to offer a response to that question, and in doing so to productively intervene in the conversation about ‘cityness’, ‘metrocentricity’ and ‘subaltern urbanism’. We intervene by following flows of rubbish electronics and the action that enacts them as waste and value, drawing on fieldwork in Dhaka, Singapore, Accra and Canada’s Greater Golden Horseshoe. Our intervention is an experiment in writing an urban geography of rubbish electronics as a site multiple. We show how following the circulation of rubbish electronics offers a many-folded synopsis of cities: urban enclaves of high finance and the information economy are also industrial waste producers. Peri-urban industrial zones are also managers of brands, legal liability and corporate public relations. Cities off the map are also urban innovation systems, while waste is rekindled as value and accumulated as poison. Thereby we suggest how a sensitivity to the site multiple may be a helpful way of grappling with shifting ontology and the performativity of our research practices in urban studies

Optical identification and follow-up observations of SRGA J213151.5+491400 -- a new magnetic cataclysmic variable discovered with SRG Observatory

We report results of optical identification and multi-wavelength study of a new polar-type magnetic cataclysmic variable (MCV), SRGA J213151.5+491400, discovered by Spectrum Roentgen-Gamma ($SRG$) observatory in the course of the all-sky survey. We present optical data from telescopes in Turkey (RTT-150 and T100 at the T\"UBITAK National Observatory), and in Russia (6-m and 1-m at SAO RAS), together with the X-ray data obtained with $ART-XC$ and $eROSITA$ telescopes aboard $SRG$ and the $NICER$ observatory. We detect SRGA J213151.5+491400 in a high state in 2020 (17.9 mag) that decreases about 3 mag into a low state (21 mag) in 2021. We find only one significant period using optical photometric time series analysis which reveals the white dwarf spin/orbital period to be 0.059710(1) days (85.982 min). The long slit spectroscopy in the high state yields a power law continuum increasing towards the blue with a prominent He II line along with the Balmer line emissions with no cyclotron humps; consistent with MCV nature. Doppler Tomography confirms the polar nature revealing ballistic stream accretion along with magnetic stream during the high state. These characteristics show that the new source is a polar-type MCV. $SRG$ $ART-XC$ detections yield an X-ray flux of (4.0-7.0)$\times$10$^{-12}$ erg cm$^2$ s$^{-1}$ in the high state. $eROSITA$ detects a dominating hot plasma component (kT$_{\rm{max}}$ $>$ 21 keV in the high state) declining to (4.0-6.0)$\times$10$^{-13}$ erg cm$^2$ s$^{-1}$ in 2021 (low state). The $NICER$ data obtained in the low state reveal a two-pole accretor showing a soft X-ray component at (6-7)$\sigma$ significance with a blackbody temperature of 15-18 eV. A soft X-ray component has never been detected for a polar in the low state before.Comment: 16 pages, 4 Tables and 15 Figures. Accepted for publication in A&A as it stand

Cosmology with the Laser Interferometer Space Antenna

The Laser Interferometer Space Antenna (LISA) has two scientific objectives of cosmological focus: to probe the expansion rate of the universe, and to understand stochastic gravitational-wave backgrounds and their implications for early universe and particle physics, from the MeV to the Planck scale. However, the range of potential cosmological applications of gravitational wave observations extends well beyond these two objectives. This publication presents a summary of the state of the art in LISA cosmology, theory and methods, and identifies new opportunities to use gravitational wave observations by LISA to probe the universe

Electron paramagnetic resonance study of radiation damage in isonipecotic acid single crystal

The electron spin resonance spectra of the radical produced by gamma-irradiation of a single crystal of isonipecotic acid (piperidine-4- carboxylic acid) were reported, and the structure of the radical was discussed. Isonipecotic acid single crystals were exposed to 60Co-gamma irradiation at room temperature. The irradiated single crystals were investigated by Electron Paramagnetic Resonance (EPR) Spectroscopy between 115 K and 300 K. The spectra were found to be temperature independent. The g values of the radiation damage center observed in isonipecotic acid single crystal and the hyperfine structure constants of the free electron with nearby protons were obtained. © 2014 Elsevier B.V. All rights reserved

Effect of ultrasound pretreatment and drying air temperature on the drying characteristics, physicochemical properties, and rehydration capacity of raisins

One of the most significant dried foods is raisin, used directly as ingredients in confectionary and in the form of raisin paste used in sauces, fillings, baked goods, microwaveable coatings, and other culinary products to color them naturally. The purpose of this study is to investigate the effects of ultrasound pretreatment (53 kHz, 300 W, 30 °C, 300 s, in a mixture of 5% K2CO3+ 1% OO solution) and drying air temperatures (40–60 °C) on the drying behavior, color values, physicochemical properties (moisture content, VCC, TPC, RSC, and antioxidant capacity (DDPH)) and rehydration capacity of Sultani Çekirdeksiz grapes. Both the drying kinetic (drying time, drying rate, and effective moisture diffusivity) and the quality characteristics of grapes were significantly improved by ultrasound pretreatment (p ;lt; 0.05). In addition, the vitamin C (0.75–3.86 mg/g) and total phenolic content (1.31–1.80 mg GA/kg) of raisins were highly protected with the high drying temperature and ultrasound pretreatment. The antioxidant capacity (1.15–5.50 mM Trolox) of samples increased with drying temperature whereas the antioxidant capacity decreased with ultrasound application. The rehydration time of all samples was found around 800 min. As a result of this study, it can be said that the ultrasound application may be used successfully for drying grapes and that a greater degree of the nutritional value of the grapes can be maintained. Graphical Abstract: [Figure not available: see fulltext.]. © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature

Monitoring of heavy metal pollution by using populus nigra and cedrus libani

As metals and metal compounds have impact on human health, it is important to identify biomonitor plants that can be used to monitor their levels in environmental and biological samples. In this study, two different plants (Populus nigra and Cedrus libani) were used as bioindicators. This was evaluated by monitoring heavy metal pollution in Kırşehir province with these plant samples collected from the vicinity of casting factory (Casting factory station) and the region where there is no casting factory (Boztepe station). Nickel (Ni), lead (Pb), and copper (Cu) levels were determined in the needle, leaves of plants, and soil samples where they grow using High Resolution-Continuum Source Flame Atomic Absorption Spectrometry (HR-CS FAAS). The levels of Ni, Pb, and Cu in Populus nigra were determined to be in the range of 0.87 to 2.59 μg/g, 0.40 to 0.75 μg/g, and 2.27 to 9.66 μg/g, respectively. In analysis of Cedrus libani, metal levels were found the range of 0.44 to 1.12 µg/g for Ni, 0.84 to 3.18 µg/g for Pb and 2.16 to 4.60 µg/g for Cu. The levels of Ni in Populus nigra samples collected from the Casting factory station (CFS) (2.49±0.09 µg/g) increased compared to the samples collected from the Boztepe station (1.16±0.24 µg/g) (p<0.05). Pb levels in Populus nigra were determined as 0.50±0.11 µg/g and 0.67±0.10 µg/g for samples collected from the CFS and Boztepe stations, respectively. Cu levels in Populus nigra were determined as 6.73±0.99 µg/g and 5.53±3.39 µg/g for the samples collected from the CFS and Boztepe stations, respectively. The levels of Pb and Cu in Populus nigra were not significant for both the stations (p>0.05). The levels of Ni in Cedrus libani samples collected from the Boztepe station (1.03±0.18 µg/g) were higher than that in the samples collected from the CFS (0.66±0.24 µg/g) (p<0.05). The levels of Pb in Cedrus libani were determined as 1.74±0.26 µg/g and 1.00±0.16 µg/g for the samples collected from the CFS and Boztepe stations, respectively (p<0.05). The levels of Cu in Cedrus libani were determined as 4.27±0.26 µg/g and 2.87±0.75 µg/g for the samples collected from the CFS and Boztepe stations, respectively (p<0.05). As a result, we suggest that Cedrus libani could be used as biomonitor plants for Pb and Cu and Populus nigra for Ni