333 research outputs found
A simple copper(II) dppy-based receptor for sensing of L-cysteine and L-histidine in aqueous acetonitrile medium
The development of simple yet efficient receptors that rapidly detect and monitor amino acids with high sensitivity and reliability is crucial for the early-stage identification of various diseases. In this work, we report the synthesis and characterisation of a copper(II) complex, CuCl2L, by employing a 2,6-dipyrazinylpyridine (dppy)-based ligand (L = 2,2′-(4-(3,4,5-trimethoxyphenyl)pyridine-2,6-diyl)dipyrazine). The in situ prepared CuCl2L receptor exhibits an instantaneous response to the presence of L-cysteine (Cys) and L-histidine (His) in aqueous acetonitrile (4[thin space (1/6-em)]:[thin space (1/6-em)]1 v/v, 10 mM HEPES buffer, pH 7.4). Furthermore, competitive experiments demonstrate the selectivity of CuCl2L towards Cys (1 equiv.) in the vicinity of other L-amino acids in the aforementioned solvent conditions. The detection limits for Cys and His are calculated as 0.33 μM and 1.40 μM, respectively. DFT calculations offer a plausible explanation for the observed selectivity of the CuCl2L receptor towards Cys and His. They reveal that the most stable conformer of Cu[thin space (1/6-em)]:[thin space (1/6-em)]Cys complex (1[thin space (1/6-em)]:[thin space (1/6-em)]1) is a five-membered ring formed through N,S-coordination mode (ΔG = −26.7 kcal mol−1) over various other possible coordination modes, while comparable ΔG values are only obtained for Cu[thin space (1/6-em)]:[thin space (1/6-em)]His complexes featuring two His moieties
Development of a knowledge based expert system on casting defects
Knowledge based expert systems are computer programs which use a collection of facts, rules of thumb to suggest solutions to specific problems. Foundry related practices are rich in thumb rules and knowledge bases which can be
implemented in such programs to help the foundrymen. One such very important use of expert systems can be in the diagnosis of casting defects. This paper outlines the proc-edure adopted to design an expert system, to identify the
casting defect by appearance and at the same time also suggest the remedial solution for the casting defect ident-ified. The knowledge-base of this expert system (named NCDA, NIFFT Casting Defect Analysis) is rule based. A large
number of rules have been built that constitute the decis-ion making sequence for each area of defect, which when consulted by the user gives a probable or certain solution depending upon the parameters supplied by him/her. The system has been built using the expert system shell VP-EXPERT. A friendly environment has been created for the user that tries to sumulate actual human interaction. The knowledge base is open to further additions or modifi-cations
284 Stratification of mortality by risk scores from the EPHESUS trial reveals significant interaction between left ventricular ejection fraction and Killip class
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106753/1/ehfs60196-4.pd
433 Regression analysis of mortality data from the EPHESUS trial reveals significantly higher risk of death for patients with non‐ST segment elevation myocardial infarction
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106689/1/ehfs60288-x.pd
Crossover between small polaron hopping and Mott's variable range hopping in Pr2MgTiO6
A combined study of X-ray diffraction (XRD) pattern and Raman spectrum
authenticates the lower symmetric orthorhombic Pnma structure for solid-state
synthesized Pr2MgTiO6 (PMT). The Ag mode demonstrates itself as a breathing
vibration of the TiO6 octahedra. The ac conductivity, dielectric relaxation,
and impedance spectra highlight the joint contributions of the grain-boundaries
and grain microstructures to the charge carrier dynamics in PMT. The double
power-law formalism is accepted to fit ac conductivity spectra. The relaxation
spectra has a non-ideal nature with the circulation of relaxation time as
observed from the impedance spectroscopic data. An equivalent circuit model has
been employed for fitting impedance data using a constant phase element (CPE)
model. The dc conductivity investigation points towards a crossover from small
polaron hopping to Mott s variable range hopping due to lowering activation
energy. The crossover between two different conduction mechanisms (Mott s
variable range and small polaron hopping) is investigated using a conjunction
of thermal varying conductivity, dielectric relaxation and impedance spectrum
in polycrystalline PMT.Comment: 10 pages, 5 figures, 4 tables. arXiv admin note: substantial text
overlap with arXiv:1707.02830, text overlap with arXiv:1904.1196
Neutral and cationic half-sandwich arene ruthenium, Cp*Rh and Cp*Ir oximato and oxime complexes: Synthesis, structural, DFT and biological studies
The reaction of [(p-cymene)RuCl2]2 and [Cp*MCl2]2 (M = Rh/Ir) with chelating ligand 2-pyridylcyanoxime {pyC(CN)NOH} leads to the formation of neutral oximato complexes having the general formula [(arene)M{pyC(CN)NO}Cl] {arene = p-cymene, M = Ru, (1); Cp*, M = Rh (2);Cp*, M = Ir (3)}. Whereas the reaction of 2-pyridyl phenyloxime {pyC(Ph)NOH} and 2-thiazolyl methyloxime {tzC(Me)NOH} with precursor compounds afforded the cationic oxide complexes bearing formula [(arene)M{pyC(ph)NOH}Cl]+ and [(arene)M{tzC(Me)NOH}Cl]+{arene = p-cymene M = Ru, (4), (7); Cp*, M = Rh (5), (8); Cp*, M = Ir (6), (9)}. The cationic complexes were isolated as their hexafluorophosphate salts. All these complexes were fully characterized by analytical, spectroscopic and X-ray diffraction studies. The molecular structures of the complexes revealed typical piano stool geometry around the metal center within which the ligand acts as a NNʹ donor chelating ligand. The Chemo-sensitivity activities of the complexes evaluated against HT-29 (human colorectal cancer), and MIAPaCa-2 (human pancreatic cancer) cell line showed that the iridium-based complexes are much more potent than the ruthenium and rhodium analogues. Theoretical studies were carried out to have a deeper understanding about the charge distribution pattern and the various electronic transitions occurring in the complexes
Ukraine–Russia Conflict and Stock Markets Reactions in Europe
This paper analyses the impact of Ukraine–Russia conflict on stock markets in Europe. We consider the stock markets of nine EU countries and Russia. The analysis consists of day-firm which includes the time between 24 November 2021 and 23 May 2022. We consider ordinary least squared (OLS) and fixed effects as baseline models. Additionally, we consider the impact of this conflict on stock return for several months, the elasticity test, the instrumental variable—two-stage least squared (2SLS) approach for the robustness test and endogeneity concerns. We find evidence of the negative impact of the Ukraine–Russia conflict on stock return of that stock markets. In addition, our finding indicates that the impact of this war on the mining construction and manufacturing sectors is greater than on other sectors because Russia and Ukraine are the key suppliers or exporters of mining and manufacturing sector. Our finding also indicates that Ukraine–Russia conflict largely affects stock return of Russian stocks because Russia is directly involved in the conflict
Oxido-and dioxido-vanadium(V) complexes supported on carbon materials: Reusable catalysts for the oxidation of cyclohexane
UIDB/00100/2020 UIDB/50006/2020 UIDP/50006/2020 CEECINST/00102/2018 UIDB/50020/2020 IST-ID/102/2018 UID/QUI/00100/2019-BL/CQE-2017-022 FCTOxidovanadium(V) and dioxidovanadium(V) compounds, [VO(OEt)L] (1) and [Et3NH][VO2L] (2), were synthesized using an aroylhydrazone Schiff base (5-bromo-2-hydroxybenzylidene)-2-hydroxybenzohydrazide (H2L). They were characterized by elemental analysis, Fourier-transform infrared spectroscopy (FT-IR), (1H and51V) nuclear magnetic resonance (NMR), electrospray ioniza-tion mass spectrometry (ESI-MS) and single crystal X-ray diffraction analyses. Both complexes were immobilized on functionalized carbon nanotubes and activated carbon. The catalytic performances of 1 and 2, homogenous and anchored on the supports, were evaluated for the first time towards the MW-assisted peroxidative oxidation (with tert-butylhydroperoxide, TBHP) of cyclohexane under heterogeneous conditions. The immobilization of 1 and 2 on functionalized carbon materials improved the efficiency of catalytic oxidation and allowed the catalyst recyclability with a well-preserved catalytic activity.publishersversionpublishe
- …