uv spectroscopy
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2022 ◽  
Vol 19 ◽  
Gulu Abbasova ◽  
Ajdar Medjidov

Abstract: A one-pot conversion of 2-hydroxy-1-naphthoic aldehyde to hydroxamic acid was described. An efficient photoorganocatalytic method of synthesis was developed. The obtained hydroxamic acid was identified by various physicochemical methods such as IR, UV- and NMR-spectroscopy. Solid colored complexes of copper (II) and iron (II), respectively, green and brown colours with the obtained hydroxamic acid were synthesized in ethanol medium for the first time. The molar ratio of ligand and metal in the complex was 2:1. Their structures were established using IR, UV- spectroscopy and thermogravimetric analysis.

2022 ◽  
Noah Bernays ◽  
Daniel Jaffe ◽  
Irina Petropavlovskikh ◽  
Peter Effertz

Abstract. Long et al (2021) conducted a detailed study of possible interferents in measurements of surface O3 by UV spectroscopy, which measures the UV transmission in ambient and O3 scrubbed air. While we appreciate the careful work done in this analysis, there were several omissions and, in one case, the type of scrubber used was mis-identified as manganese dioxide (MnO2), when in fact it was manganese chloride (MnCl2). This misidentification led to the erroneous conclusion that all UV-based O3 instruments employing solid-phase catalytic scrubbers exhibit significant positive artifacts, whereas previous research found this not to be the case when employing MnO2 scrubber types. While the Long study, and our results, confirm the substantial bias in instruments employing an MnCl2 scrubber, a replication of the earlier work with an MnO2 scrubber type and no humidity correction is needed.

2022 ◽  
Vol 41 (1) ◽  
pp. 34-62
Andrea Dandić ◽  
Katarina Rajkovača ◽  
Marija Jozanović ◽  
Iva Pukleš ◽  
Aleksandar Széchenyi ◽  

Abstract Nonsteroidal anti-inflammatory drugs (NSAIDs) are the first choice of treatment for rheumatic disorders and other degenerative inflammatory diseases. One of them, indomethacin (INDO), is highlighted in this study. With its analgesic, antipyretic, and anti-inflammatory properties, it is one of the most powerful drugs used in various clinical trials and therapies related to the mechanism of blocking prostaglandin synthesis, thus reducing and eliminating many inflammatory conditions in patients. To ensure the efficacy and safety of this drug in pharmaceutical and clinical use, precise product quality control is required. Such control is performed with routine pharmaceutical analysis using various chemical methods by which INDO is identified as a separate active ingredient in the multicomponent system of a complete pharmaceutical form. In addition, the determination of INDO is important in clinical practice, where its concentration is determined in different biological samples, ensuring better monitoring of a particular therapy. The most commonly used methods for the determination of INDO are high-performance liquid chromatography (37% of developed methods), voltammetry (16% of developed methods), and UV spectroscopy (11% of developed methods). However, each of these methods must provide precise validation parameters. A combination of analytical methods can lead to more precise results and safer application in practice.

Sheng-Lung Chou ◽  
Meng-Yeh Lin ◽  
Tzu-Ping Huang ◽  
Shu-Yu Lin ◽  
Min-Zhen Yang ◽  

2022 ◽  
Vol 34 (2) ◽  
pp. 342-354
D. Senthil Kumar ◽  
D. Karthikeyan ◽  
Biswabara Roy

The present study was aimed to phytochemical and GC-MS analysis for chloroform extract of Tinospora cardifolia. The structure of the compounds was further confirmed by UV-spectroscopy and FTIR study. The in silico study like molecular, physico-chemical and drug likeliness property was carried out by computational approaches for the identified molecules. Further toxicity potential and pharmacokinetic profile were also determined. The study was carried out using OSIRIS data warrior and Swiss ADME tools. The docking analysis was carried out for the antidiabetic and anti-inflammatory profiles. The compounds were targeted for α-glucosidase, peroxisome proliferator-activated receptor, glucose transporter-1, cyclo-oxygenase-1 & 2 inhibitions. There were around 12 compounds identified by GC-MS analysis. All the compounds exhibited moderate to good drug likeliness and pharmacokinetic potentials. The molecules showed a good bioactivity score against enzyme receptors. The ADMET prediction showed PGP and CYP-inhibitory effects with the least toxic profile. The docking analysis showed strong binding affinity of [1S-(1α,3aα,4α,6aα)]-1H,3H-furo[3,4-c]furan tetrahydrophenyl (molecule-7) on targeted proteins under investigation.

2022 ◽  
Vol 17 (01) ◽  
pp. C01047
E. Fabbrica ◽  
M. Carminati ◽  
D. Butta ◽  
M. Uslenghi ◽  
M. Fiorini ◽  

Abstract We present the design of the first prototype of MIRA (MIcro-channel plate Readout ASIC) that has been designed to read out Micro-Channel Plates (MCP), in particular for UV spectroscopy. MIRA will be able to detect the cloud of electrons generated by each photon interacting with the MCP, sustaining high local and global count rates to fully exploit the MCP intrinsic dynamic range with low dead time. The main rationale that guided the electronics design is the reduction of the input Equivalent Noise Charge (ENC) in order to allow operations with lower MCP gain, thus improving its lifetime, crucial aspect for long missions in space. MIRA features two selectable analog processing times, 133 ns or 280 ns (i.e. fast mode or slow mode), granting a count rate per pixel of 100 kcps. Moreover, it shows an Equivalent Noise Charge ENC = 17 e r m s − . A spatial resolution of 35 μm and an operation with zero dead time, due to the readout, are targeted. The low noise, high count rate and high spatial resolution requirements are expected by keeping a compact pixel size (35 μm × 35 μm) for a total of 32 × 32 pixels in a 2 mm × 2 mm ASIC area. In this work, the ASIC design is described.

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 201
Sayed E. El-Sayed ◽  
Neveen A. Abdelaziz ◽  
Hosam-Eldin Hussein Osman ◽  
Ghadir S. El-Housseiny ◽  
Ahmed E. Aleissawy ◽  

Resistance to antifungal agents represents a major clinical challenge, leading to high morbidity and mortality rates, especially in immunocompromised patients. In this study, we screened soil bacterial isolates for the capability of producing metabolites with antifungal activities via the cross-streak and agar cup-plate methods. One isolate, coded S6, showed observable antifungal activity against Candida (C.) albicans ATCC 10231 and Aspergillus (A.) niger clinical isolate. This strain was identified using a combined approach of phenotypic and molecular techniques as Lysinibacillus sp. MK212927. The purified metabolite displayed fungicidal activity, reserved its activity in a relatively wide range of temperatures (up to 60 °C) and pH values (6–7.8) and was stable in the presence of various enzymes and detergents. As compared to fluconazole, miconazole and Lamisil, the minimum inhibitory concentration of the metabolite that showed 90% inhibition of the growth (MIC90) was equivalent to that of Lamisil, half of miconazole and one fourth of fluconazole. Using different spectroscopic techniques such as FTIR, UV spectroscopy, 1D NMR and 2D NMR techniques, the purified metabolite was identified as terbinafine, an allylamine antifungal agent. It is deemed necessary to note that this is the first report of terbinafine production by Lysinibacillus sp. MK212927, a fast-growing microbial source, with relatively high yield and that is subject to potential optimization for industrial production capabilities.

Molbank ◽  
10.3390/m1310 ◽  
2021 ◽  
Vol 2022 (1) ◽  
pp. M1310
Nikita S. Gudim ◽  
Ekaterina A. Knyazeva ◽  
Oleg A. Rakitin

2,6-Bis(benzo[c][1,2,5]thiadiazol-4-yl)-4H-cyclopenta[2,1-b:3,4-b’]dithiophenes are of interest for the synthesis of molecules which can be employed in optoelectronic devices. In this communication, 7,7’-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b’]dithiophene-2,6-diyl)bis(4-bromobenzo[c][1,2,5]thiadiazole) was obtained by direct C–H cross-coupling of 4,7-dibromobenzo[c][1,2,5]thiadiazole with 4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b’]dithiophene in the presence of palladium(II)acetate and potassium pivalate. The structure of newly synthesized compound was established by means of elemental analysis, high-resolution mass spectrometry, 1H, 13C NMR, IR and UV spectroscopy.

2021 ◽  
Sreeja Balakrishnapillai Susselaa ◽  
Radha Sankararajan ◽  
Palanisamy Govindasamy ◽  
Pazhanivel Thangavelu ◽  

Abstract A simple wet impregnation approach had been used to the successful preparation of different weight percentages of strontium/niobium doped Er2O3 nanoparticles. The X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), high resolution transmission electron microscope (HR-TEM), Fourier transformed infrared spectroscopy (FTIR), and UV-visible (UV) spectroscopy was used to analyze the samples as they were prepared. With Sr and Nb doping at Er2O3 nanoparticles, the XRD patterns intensity was shifted, and its positioning was also shifted as weight percentages of doped were increased. Similarly, the lattice d spacing values were also decreased. According to HR-TEM images, Er2O3 seems to have a two-dimensional hexagonal nanoplate-like structure as well as being a few nm in size. The photocatalytic activities of pristine and Sr/Nb doped samples were evaluated against the methyl orange (MO) and rhodamine B (Rh B) dyes under UV-visible light irradiation. Within seventy-five minutes of UV-Visible light irradiation, the five-weight percentage of Sr doped Er2O3 nanoparticles shows significantly enhanced photocatalytic degradation efficiency against Rh B dye. The synergistic effect of the strong metal-support interaction between the Sr and Er2O3 nanoparticles could be attributed to the improved photocatalytic activity of the prepared samples. The cyclic stability and radical trapping experiments were also investigated against the same reaction conditions.

2021 ◽  
Vol 11 (40) ◽  
pp. 117-117
Ursula Wolf ◽  
Sabine Klein ◽  
Annegret Sandig ◽  
Stephan Baumgartner

Background Several series of experiments from our research group have shown ultraviolet (UV) light transmission of homeopathic preparations to slightly but significantly differ from controls. We now investigated whether visible and near infrared spectroscopy were also useful for exploring properties of homeopathic preparations. Materials and methods Homeopathic preparations of copper sulfate (CuSO4), hypericum and sulfur (S8) were produced in 30 sequential steps of 1:100 dilutions (c-preparations). As controls, succussed potentization medium was used. Transmission of the samples from 190-1100nm was measured 4 times on 5 days with a double beam Shimadzu UV PC 1601 spectrophotometer. To correct for the daily variations of the spectrophotometer, transmission of the samples at each nm was divided by the average transmission of the controls. Median transmissions of the samples were calculated for the ranges of 190-340nm (near and middle UV), 340-640nm (visible light without red), and 640-1100nm (red and near infrared). Differences in the median transmission between potency levels from 6c to 30c were determined using Kruskal-Wallis and Jonckheere-Terpstra tests. Results Differences in transmissions of the various potency levels were more pronounced in the UV range than in the visible or red/near infrared range. The Kruskal-Wallis test revealed significant differences for homeopathic preparations of CuSO4, hypericum and S8 in the UV range (p=0.032, 0.008, 0.009, respectively) and of S8 in the visible range (p=0.026). Jonckheere's test showed a tendency towards ascending medians with ascending potency levels for CuSO4 in the UV range (p=0.080). Significant trends were revealed for hypericum in the visible range (p=0.042, descending medians) and S8 in the UV range (p=0.015, ascending medians). Conclusion UV spectroscopy seemed to be more suitable for investigating homeopathic preparations than visible or near infrared spectroscopy, since differences in transmission were more pronounced in the UV range.

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