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In recent years, extensive research has been directed towards understanding the interactions between various zinc complexes with DNA, specifically delving into their intercalation and binding behaviors. The binding of zinc complexes to DNA is particularly intriguing due to their distinctive intercalating capabilities. This study unveils a remarkable phenomenon observed with a specific Zn complex, ([B-Zn-N3], where B is a Schiff base ligand), during DNA intercalation investigations in the popular DMSO-Water binary solvent mixture. An unanticipated observation revealed time-dependent changes in the UV-visible absorption spectroscopic studies, coupled with the existence of an isosbestic point. This observation questions the stability of the intercalating agent itself during the intercalation process. The emergence of a decomposed product during the intercalation study has been confirmed through various analytical techniques, including CHN analysis, MALDI mass, XPS, Raman spectroscopy, and Powder XRD. The change in the chemical species on intercalation is further substantiated by theoretical studies, adding depth to our understanding of the intricate dynamics at play during DNA intercalation with the [B-Zn-N3] complex in the DMSO-Water system.
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DNA , Dimetil Sulfóxido , Substâncias Intercalantes , Água , Dimetil Sulfóxido/química , Substâncias Intercalantes/química , DNA/química , DNA/metabolismo , Água/química , Análise Espectral Raman , Zinco/química , Espectrofotometria Ultravioleta , Complexos de Coordenação/química , Complexos de Coordenação/metabolismo , Bases de Schiff/químicaRESUMO
There have been numerous instances of lanthanide NIR emitting material where one or more types of ligands or metal ion-ligand complexes operate as antennas. The antenna's role in NIR emission has also been thoroughly investigated and validated. The emission properties of the different antennae are predicted to differ. Here we describe the structural and photophysical properties of two series of [ZnII-LnIII] complexes, where a minor difference between the two series (ethoxy vs methoxy substitution) affected the photophysical properties, particularly the f-f transition, in an unprecedented manner. Both steady-state and time-resolved luminescence spectra were affected by this change. Detailed single-crystal X-ray diffraction (SCXRD) and X-ray photoelectron spectroscopy (XPS) studies of both complexes revealed the crucial structural differences in crystal packing, which astonishingly remains unaffected in solution.
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The first slow magnetic relaxation in a ferromagnetic Cu(II) chain compound, Cu(dipic)(OH2)2 (dipicH2 = pyridine-2,6-dicarboxylic acid), induced by a phonon bottleneck effect under a magnetic field of 0.6 T, with a relaxation time of 2.2 s at 2.8 K, was observed.
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Introduction: Among the benign primary bone tumors, Giant cell tumor (GCT) accounts for about 3% to -5%. It is a locally aggressive tumor with maximum incidence between 20 to and 40 years of age. The sites where GCT is most commonly seen are distal femur, and proximal tibia followed by distal end radius. Distal end of ulna is a rare site with an incidence of only 0.45% to -3.2%. Case Report: We report a case of a 32- year- old male with (GCT) giant cell tumor of the left distal ulna. We managed the patient with en bloc resection of distal ulna along with reconstruction of distal radio ulnar joint (DRUJ) and triangular fibro cartilage complex (TFCC) using proximal fibula graft and palmaris longus graft. DRUJ was stabiliszed with a k- wire. Conclusion: After 1 year of follow- up, patient showed good results in terms of range of movements of the wrist joint with no evidence of recurrence.
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Here, we report the existence of a pentameric water cluster in the host framework of [Cu(cyclam)(N3)2]·4H2O, that is stable upto 167 °C, well above the boiling point of water. The pentameric cluster structure embedded in the host framework is evident from the single crystal studies. The high thermal stability is confirmed by TGA and temperature dependent confocal Raman microscopic studies, where loss of water bands is well captured between 167 and 170 °C, besides its existence through SCXRD studies. To the best of our knowledge, this is the first report where temperature dependent confocal Raman microscopic investigation is used to study the stability of water in crystal environment. The study promises that temperature dependent confocal Raman microscopy can be an efficient tool to investigate the existence and stability of small water clusters, precisely in restricted environments.
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A new acrylamide monomer, N-isopropyl-N-(3-(isopropylamino)-3-oxopropyl)acrylamide (M3i), consisting of both isopropyl and isopropylamidopropyl moieties, has been synthesized from isopropylamine and N-isopropylacrylamide via an aza-Michael addition reaction followed by amidation with acryloyl chloride. The homopolymer of M3i (polyM3i) and a series of random copolymers of M3i and poly(ethylene glycol)methyl ether acrylate (PEGA: CH2îCHCO2(CH2CH2O)nMe, Mn = 480, n = 9 on average) with varying compositions have been synthesized via reversible addition-fragmentation chain transfer polymerization using 2-(dodecylthiocarbonothioylthio)-2-methylpropionic acid (DDMAT) as well as 1-phenylethyl phenyl dithioacetate (PEPD) as a RAFT agent. These polymers have been characterized by 1H NMR, FTIR, GPC, UV-Vis, fluorescence, TGDTA, DSC, DLS, and TEM techniques. A lower critical solution temperature (LCST) and glass transition temperature (Tg) for polyM3i prepared using DDMAT were observed at 17 and 133 °C, respectively, while for a polymer formed using PEPD, no LCST was observed until 0 °C and its observed Tg was found at 127.3 °C. The polymers are thermally stable up to 300 °C. Upon an increase in the M3i content in the copolymers, LCST decreases, Tg increases, and the apparent hydrodynamic diameter decreases. Moreover, the effects of concentration and the addition of urea and sodium chloride on the LCST of the copolymer with an LCST close to body temperature were studied. Owing to the incorporation of PEGA, a higher critical micellar concentration and larger TEM particle size of this copolymer were observed with respect to those of polyM3i. The usefulness of the micelles of the copolymers as nano-carriers for the drug doxorubicin was explored. The in vitro tumoricidal activity of the micelles of the doxorubicin-loaded copolymers was also assessed against Dalton's lymphoma cells.
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Antineoplásicos , Éteres Metílicos , Micelas , Acrilamida , Cloreto de Sódio , Polímeros/química , Acrilamidas/química , Doxorrubicina/farmacologia , Doxorrubicina/química , Antineoplásicos/farmacologia , Antineoplásicos/química , Polietilenoglicóis/química , UreiaRESUMO
In this report, we have introduced magnetic ordering into the nontrivial system of conventional topological insulators (TIs) by creating magnetic interfaces. In this context, antimony di-chalcogenide Sb2Te3 sandwiched between two thin layers of FeSe was prepared using the pulsed laser deposition (PLD) technique. The prepared heterostructure demonstrated good crystallinity along with homogeneous morphology displaying pyramid-shaped characteristic triangular islands. To comprehend the temperature and magnetic field modulated inter-layer properties of the prepared hetero-structure, transport, magneto-transport and magnetic properties were investigated. These properties establish the signature of the Kondo effect below 15 K, which has been attributed to the antiferromagnetic spin alignment in that temperature range. At around 150 K, longitudinal and transverse resistivity shows the metal-semiconductor transition, which was further elucidated through the anharmonic decay model in vibration phonon modes using Raman spectroscopy. Furthermore, a significant local spin evolution was explored at around 475 K by studying the magnetic properties of the system. The temperature dependency of the Raman modes confirmed the spin-phonon coupling initiated by local charge ordering at the proximity of the interface in the prepared hetero-structure.
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Among various interactions (such as H-bonding, π - π stacking interaction) which are responsible for the fascinating metallo-architectures, cation - π interaction has emerged as a significantly important force. Moreover, it has now been observed that this interaction is found to be presented ubiquitous across several fields of contemporary interest, such as chemistry, material science, and biology. In this work, we have focused on the design and synthesis of a pentacyano organic anion and potassium cation based 3D coordination polymer (5CNP). The single-crystal XRD structure revealed fascinating structural arrangements due to the existence of several intra and interionic interaction. To the best of our knowledge, such polycyano aromatic system based 3D coordination polymer is not reported. In addition to single crystal X-ray diffraction (SCXRD), we have employed confocal Raman microscopic techniques to understand the structural aspects, particularly the pentacyano functional groups which are Raman active. Considering the prospect of 5CNP as a material, thermal stability, and structyral properties have been studied, in addition to detailed photophysical aspects. The photophysical responses in solid and in solution have been studied by steady and time-resolved fluorescence spectroscopy. Interesting photophysical observation is noted when studied in a binary mixture of THF-toluene. Scanning electron microscopy (SEM) studies have also been done for comprehensive understanding. In the end, cytotoxicity studies have been undertaken to evaluate the toxicity of 5CNP in our cells.
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The magneto-transport, magnetization and theoretical electronic-structure have been investigated on type-II Weyl semimetallic MoTeP. The ferromagnetic ordering is observed in the studied sample and it has been shown that the observed magnetic ordering is due to the defect states. It has also been demonstrated that the presence of ferromagnetic ordering in effect suppresses the magnetoresistance (MR) significantly. Interestingly, a change-over from positive to negative MR is observed at higher temperature which has been attributed to the dominance of spin scattering suppression.
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Selective formation of positional isomers and accordingly tuning the physicochemical properties of small conjugated organic molecules through structural isomers is an effective crystal engineering for a fascinating successful delivery of thermally stable and photophysically exciting compounds. By small structural skeleton changes, the single crystal of the naphthalenemaleonitrile isomers is found to exhibit a drastic change in crystal packing array, which in turn is found to tune the thermal and physicochemical properties. The α-isomer (A) forms the "herringbone packing" (HP) due to peri-interaction-sensitive C-H···(Ar)π (Ar = naphthalene ring) interactions, and the ß-isomer (B) forms the "bricklayer packing" (BP) due to π(C≡N)···π(Ar) stacking interactions. These two positional isomers have revealed insight of molecular packing-dependent structure-property relationship. In this report, we show that a simple modification of relatively less common weak interactions, such as C-H···π(Ar) â π(C≡N)···π(Ar), through the preparation of isomers, can lead to a drastic change in crystal packing (HP â BP). Also, this report demonstrates that by a small structural diversity, one can obtain significant changes in the physicochemical properties like melting behavior, enthalpy, entropy, and electrical properties in the solid state. Therefore, it transpires from this study that structural isomer provides a useful complement to intermolecular nonbonding interactions as a tool to design new promising materials.