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Observation of a Nuclear Recoil Peak at the 100 eV Scale Induced by Neutron Capture. PHYSICAL REVIEW LETTERS 2023; 130:211802. [PMID: 37295094 DOI: 10.1103/physrevlett.130.211802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 02/12/2023] [Accepted: 04/13/2023] [Indexed: 06/12/2023]
Abstract
Coherent elastic neutrino-nucleus scattering and low-mass dark matter detectors rely crucially on the understanding of their response to nuclear recoils. We report the first observation of a nuclear recoil peak at around 112 eV induced by neutron capture. The measurement was performed with a CaWO_{4} cryogenic detector from the NUCLEUS experiment exposed to a ^{252}Cf source placed in a compact moderator. We identify the expected peak structure from the single-γ de-excitation of ^{183}W with 3σ and its origin by neutron capture with 6σ significance. This result demonstrates a new method for precise, in situ, and nonintrusive calibration of low-threshold experiments.
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Characterization of a kg-scale archaeological lead-based PbWO 4 cryogenic detector for the RES-NOVA experiment. Appl Radiat Isot 2023; 194:110704. [PMID: 36731392 DOI: 10.1016/j.apradiso.2023.110704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 01/21/2023] [Accepted: 01/26/2023] [Indexed: 01/30/2023]
Abstract
Core-collapse Supernovae (SNe) are one of the most energetic events in the Universe, during which almost all the star's binding energy is released in the form of neutrinos. These particles are direct probes of the processes occurring in the stellar core and provide unique insights into the gravitational collapse. RES-NOVA will revolutionize how we detect neutrinos from astrophysical sources, by deploying the first ton-scale array of cryogenic detectors made from archaeological lead. Pb offers the highest neutrino interaction cross-section via coherent elastic neutrino-nucleus scattering (CEνNS). Such process will enable RES-NOVA to be equally sensitive to all neutrino flavours. For the first time, we propose the use archaeological Pb as sensitive target material in order to achieve an ultra-low background level in the region of interest (O(1 keV)). All these features make possible the deployment of the first cm-scale neutrino telescope for the investigation of astrophysical sources. In this contribution, we will characterize the radiopurity level and the performance of a small-scale proof-of-principle detector of RES-NOVA, consisting in a PbWO4 crystal made from archaeological-Pb operated as cryogenic detector.
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Secular equilibrium assessment in a CaWO 4 target crystal from the dark matter experiment CRESST using Bayesian likelihood normalisation. Appl Radiat Isot 2023; 194:110670. [PMID: 36696751 DOI: 10.1016/j.apradiso.2023.110670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 11/06/2022] [Accepted: 01/13/2023] [Indexed: 01/22/2023]
Abstract
CRESST is a leading direct detection sub-GeVc-2 dark matter experiment. During its second phase, cryogenic bolometers were used to detect nuclear recoils off the CaWO4 target crystal nuclei. The previously established electromagnetic background model relies on Secular Equilibrium (SE) assumptions. In this work, a validation of SE is attempted by comparing two likelihood-based normalisation results using a recently developed spectral template normalisation method based on Bayesian likelihood. Albeit we find deviations from SE in some cases we conclude that these deviations are artefacts of the fit and that the assumptions of SE is physically meaningful.
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Synthesis, characterization, and anticancer activity of chitosan functionalized isatin based thiosemicarbazones, and their copper(II) complexes. Carbohydr Res 2023; 526:108796. [PMID: 36944301 DOI: 10.1016/j.carres.2023.108796] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 02/17/2023] [Accepted: 03/14/2023] [Indexed: 03/17/2023]
Abstract
The one-pot synthetic method of condensation of isatin and 5-chloroisatin on to amino group at C2 position of the pyranose ring chitosan in chitosan thiosemicarbazide was employed to get these chitosan thiosemicarbazones (TSCs). The partial incorporation of thiosemicarbazone moiety in chitosan was shown by FT-IR and 13C NMR spectroscopic studies, powder X ray diffraction, and CHNS microanalysis. The NOS tridentate coordination behavior of TSCs with copper(II) chloride to give the square planar complexes was established by FT-IR spectroscopic data, magnetic susceptibility measurement, and EPR spectral analysis. The thermal stability of these biomaterial chitosan derivatives till the commencement of chain disruption at 200C was shown by thermal studies. As revealed by colorimetric MTT assays, the in vitro anticancer activity enhancement accorded with the functionalization of chitosan as isatin based chitosan TSCs, and NOS tridentate coordination of TSCs plus a monodentate coordination of chloride ion with copper(II) ion. Only a marginal activity difference of these compounds was observed against the tumorigenic MDCK and MCF-7 cancer cell lines, irrespective of unit molecular weight (Mw) and degree of deacetylation (DDA) of ring chitosan. The 5-chloroisatin chitosan TSCs showed better activity than isatin chitosan TSCs against both the cell lines.
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Towards an automated data cleaning with deep learning in CRESST. EUROPEAN PHYSICAL JOURNAL PLUS 2023; 138:100. [PMID: 36741916 PMCID: PMC9886615 DOI: 10.1140/epjp/s13360-023-03674-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/02/2023] [Indexed: 06/18/2023]
Abstract
The CRESST experiment employs cryogenic calorimeters for the sensitive measurement of nuclear recoils induced by dark matter particles. The recorded signals need to undergo a careful cleaning process to avoid wrongly reconstructed recoil energies caused by pile-up and read-out artefacts. We frame this process as a time series classification task and propose to automate it with neural networks. With a data set of over one million labeled records from 68 detectors, recorded between 2013 and 2019 by CRESST, we test the capability of four commonly used neural network architectures to learn the data cleaning task. Our best performing model achieves a balanced accuracy of 0.932 on our test set. We show on an exemplary detector that about half of the wrongly predicted events are in fact wrongly labeled events, and a large share of the remaining ones have a context-dependent ground truth. We furthermore evaluate the recall and selectivity of our classifiers with simulated data. The results confirm that the trained classifiers are well suited for the data cleaning task.
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Pyridine-Based NNS Tridentate Chitosan Thiosemicarbazones and Their Copper(II) Complexes: Synthesis, Characterization, and Anticancer Activity. ACS OMEGA 2022; 7:30978-30988. [PMID: 36092560 PMCID: PMC9453788 DOI: 10.1021/acsomega.2c02966] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 08/05/2022] [Indexed: 06/01/2023]
Abstract
Chitosan-functionalized pyridine-based thiosemicarbazones and their copper(II) complexes have been found to own a substantial antiproliferative activity against the tumorigenic Madin Darby canine kidney (MDCK) and MCF-7 cancer cell lines. In the current study, chitosan oligosaccharide (CS) (87% DDA, Mw < 3000 Da) and crab shell chitosan (CCS) (67% DDA, M w 350 kDa) were functionalized as chitosan pyridine-2-thiosemicarbazones and chitosan 2-acetyl pyridine-2-thiosemicarbazones, and their copper(II) complexes were synthesized. The formation of chitosan thiosemicarbazones and their NNS tridentate behavior to give the square planar copper(II) chitosan thiosemicarbazone complexes were established by spectroscopic studies, powder X-ray diffraction, elemental analysis, and magnetic moment measurements. The thermal study showed a marked stability of these derivatives before the outset of chitosan backbone degradation at 200 °C. The colorimetric MTT assay revealed a higher activity of CS thiosemicarbazones, viz., CSTSC series (IC50 375-381 μg mL-1 in the MDCK cell line and 281-355 μg mL-1 in the MCF-7 cell line) than that of high-molecular-weight CCS thiosemicarbazones, viz., CCSTSC series (IC50 335-400 μg mL-1 in the MDCK cell line and 365-400 μg mL-1 in the MCF-7 cell line), showing an enhanced activity with a decrease in Mw and an increase in DDA of constituent chitosan, a higher activity of both of these series of thiosemicarbazones than that of their native chitosan, viz., CS (IC50 370 μg mL-1 in the MCF-7 cell line and >400 μg mL-1 in the MDCK cell line) and CCS (IC50 > 400 μg mL-1 in both cell lines), and a higher activity of the Cu-CSTSC complexes (IC50 322-342 μg mL-1 in the MDCK cell line and 278-352 μg mL-1 in the MCF-7 cell line) and Cu-CCSTSC complexes (IC50 274-400 μg mL-1 in the MDCK cell line and 231-352 μg mL-1 in the MCF-7 cell line) than that of their respective ligands.
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Chitosan functionalized thiophene-2-thiosemicarbazones, and their copper(II) complexes: synthesis, characterization, and anticancer activity. JOURNAL OF MACROMOLECULAR SCIENCE PART A-PURE AND APPLIED CHEMISTRY 2022. [DOI: 10.1080/10601325.2021.2022982] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Supramolecular Cylinders Target Bulge Structures in the 5' UTR of the RNA Genome of SARS-CoV-2 and Inhibit Viral Replication. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 133:18292-18299. [PMID: 38505190 PMCID: PMC10947172 DOI: 10.1002/ange.202104179] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Indexed: 01/09/2023]
Abstract
The untranslated regions (UTRs) of viral genomes contain a variety of conserved yet dynamic structures crucial for viral replication, providing drug targets for the development of broad spectrum anti-virals. We combine in vitro RNA analysis with molecular dynamics simulations to build the first 3D models of the structure and dynamics of key regions of the 5' UTR of the SARS-CoV-2 genome. Furthermore, we determine the binding of metallo-supramolecular helicates (cylinders) to this RNA structure. These nano-size agents are uniquely able to thread through RNA junctions and we identify their binding to a 3-base bulge and the central cross 4-way junction located in stem loop 5. Finally, we show these RNA-binding cylinders suppress SARS-CoV-2 replication, highlighting their potential as novel anti-viral agents.
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Supramolecular Cylinders Target Bulge Structures in the 5' UTR of the RNA Genome of SARS-CoV-2 and Inhibit Viral Replication*. Angew Chem Int Ed Engl 2021; 60:18144-18151. [PMID: 33915014 PMCID: PMC8222931 DOI: 10.1002/anie.202104179] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Indexed: 12/13/2022]
Abstract
The untranslated regions (UTRs) of viral genomes contain a variety of conserved yet dynamic structures crucial for viral replication, providing drug targets for the development of broad spectrum anti-virals. We combine in vitro RNA analysis with molecular dynamics simulations to build the first 3D models of the structure and dynamics of key regions of the 5' UTR of the SARS-CoV-2 genome. Furthermore, we determine the binding of metallo-supramolecular helicates (cylinders) to this RNA structure. These nano-size agents are uniquely able to thread through RNA junctions and we identify their binding to a 3-base bulge and the central cross 4-way junction located in stem loop 5. Finally, we show these RNA-binding cylinders suppress SARS-CoV-2 replication, highlighting their potential as novel anti-viral agents.
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BODIPY-linked cis-dichlorido zinc(ii) conjugates: the strategic design of organelle-specific next-generation theranostic photosensitizers. Dalton Trans 2021; 50:103-115. [DOI: 10.1039/d0dt03342a] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cis-dichlorido Zn(ii)–BODIPY-based smart theranostic photosensitizers, as alternatives to Zn-porphyrins/phthalocyanines, show mitochondrion-targeted and imaging guided type-II photodynamic therapeutic activity.
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Rotaxanating Metallo-supramolecular Nano-cylinder Helicates to Switch DNA Junction Binding. J Am Chem Soc 2020; 142:20651-20660. [DOI: 10.1021/jacs.0c07750] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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12
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Thermal neutron-induced γ-ray background in 124Sn. Appl Radiat Isot 2020; 158:108923. [PMID: 32174381 DOI: 10.1016/j.apradiso.2019.108923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 09/23/2019] [Accepted: 10/02/2019] [Indexed: 10/25/2022]
Abstract
The thermal neutron-induced gamma-ray background in 124Sn is investigated in connection with neutrinoless double beta decay (0νββ) studies in 124Sn. For this purpose, a 99.26% enriched 124Sn sample was irradiated with a thermal neutron fluence of 3×1015/cm2 in the Dhruva reactor at the Bhabha Atomic Research Centre, Mumbai. The gamma ray spectra of the irradiated sample were measured in a low background counting setup to study both long-lived and short-lived activities. The present data give an independent measurement of the half-life of 125Sn*(32+) and 125Sn(112-) as 10.01(8) min and 9.63(2) d, respectively. The impact of the observed high-energy gamma rays and the residual activity due to 125Sb, on the background in the region of interest around the Qββ value of 124Sn (~2.291 MeV) is discussed.
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Ruthenium(II) Conjugates of Boron-Dipyrromethene and Biotin for Targeted Photodynamic Therapy in Red Light. Inorg Chem 2019; 59:913-924. [PMID: 31825210 DOI: 10.1021/acs.inorgchem.9b03178] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The ruthenium(II) complexes [RuCl(L1)(L3)]Cl (1), [RuCl(L1)(L4)]Cl (2), [RuCl(L2)(L4)]Cl (3), [RuCl(L1)(L5)]Cl (4), and [RuCl(L2)(L5)]Cl (5) of NNN-donor dipicolylamine (dpa) bases (L4, L5) having BODIPY (boron-dipyrromethene) moieties, NN-donor phenanthroline derivatives (L1, L2), and benzyldipicolylamine (bzdpa, L3) were prepared and characterized by spectroscopic techniques and their cellular localization/uptake and photocytotoxicity studied. Complex 1, as its PF6 salt (1a), has been structurally characterized with help of a single-crystal X-ray diffraction technique. It has a RuN5Cl core with the Cl bonded trans to the amine nitrogen atom of bzdpa. The complexes showed intense absorption spectral bands near 500 nm (ε ≈ 58000 M-1 cm-1) in 2 and 3 and 654 nm (ε ≈ 80000 M-1 cm-1) in 4 and 5 in 1/1 DMSO/DPBS (v/v). Complex 5 having biotin and PEGylated-disteryl BODIPY gave a singlet oxygen quantum yield (ΦΔ) of ∼0.65 in DMSO. Complex 5 exhibited remarkable PDT (photodynamic therapy) activity (IC50 ≈ 0.02 μM) with a photocytotoxicity index (PI) value of >5000 in red light of 600-720 nm in A549 cancer cells. The biotin-conjugated complexes showed better photocytotoxicity in comparison to nonbiotinylated analogues in A549 cells. The complexes displayed less toxicity in HPL1D normal cells in comparison to A549 cancer cells. The emissive BODIPY complexes 3 and 5 (ΦF ≈ 0.07 in DMSO) showed significant mitochondrial localization.
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Recent advances in uranyl binding in proteins thanks to biomimetic peptides. J Inorg Biochem 2019; 203:110936. [PMID: 31864150 DOI: 10.1016/j.jinorgbio.2019.110936] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 11/05/2019] [Accepted: 11/17/2019] [Indexed: 12/29/2022]
Abstract
Uranium is an element belonging to the actinide series. It is ubiquitous in rock, soil, and water. Uranium is found in the ecosystem due to mining and milling industrial activities and processing to nuclear fuel, but also to the extensive use of phosphate fertilizers. Understanding uranium binding in vivo is critical, first to deepen our knowledge of molecular events leading to chemical toxicity, but also to provide new mechanistic information useful for the development of efficient decorporation treatments to be applied in case of intoxication. The most stable form in physiological conditions is the uranyl cation (UO22+), in which uranium oxidation state is +VI. This short review presents uranyl coordination properties and chelation, and what is currently known about uranium binding to proteins. Although several target proteins have been identified, the UO22+ binding sites have barely been identified. Biomimetic approaches using model peptides are good options to shed light on high affinity uranyl binding sites in proteins. A strategy based on constrained cyclodecapeptides allowed recently to propose a tetraphosphate binding site for uranyl that provides an affinity similar to the one measured with the phosphoprotein osteopontin.
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Corrigendum: Mitochondria‐Targeted Anticancer Activity of BODIPY‐Appended Iron(III) Catecholates in Red Light. ChemistrySelect 2019. [DOI: 10.1002/slct.201903601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Crystal structure, DNA crosslinking and photo-induced cytotoxicity of oxovanadium(IV) conjugates of boron-dipyrromethene. J Inorg Biochem 2019; 202:110817. [PMID: 31706182 DOI: 10.1016/j.jinorgbio.2019.110817] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 08/27/2019] [Accepted: 09/01/2019] [Indexed: 01/01/2023]
Abstract
Cis-dichloro-oxovanadium(IV) complexes [VO(L1/L2)Cl2], where L1 is N-(4-(5,5-difluoro-1,3,7,9-tetramethyl-5H-4ʎ4,5ʎ4-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborinin-10-yl)benzyl)-1-(pyridin-2-yl)-N-(pyridin-2-ylmethyl)methanamine in 1 and L2 is N-(4-(5,5-difluoro-2,8-diiodo-1,3,7,9-tetramethyl-5H-4ʎ4,5ʎ4-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborinin-10-yl)benzyl)-1-(pyridin-2-yl)-N-(pyridin-2-ylmethyl)methanamine in 2) having 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene as boron-dipyrromethene (BODIPY) appended dipicolylamine bases were prepared, characterized and their photocytotoxicity studied. X-ray crystal structure of 1 showed distorted octahedral geometry with a VIVON3Cl2 core having Cl-V-Cl angle of 91.93(4)°. The complexes showed variable solution conductivity properties. They were non-electrolytes in dry DMF at 25 °C but showed 1:1 electrolytic behavior in an aqueous medium due to dissociation of one chloride ligand as evidenced from the mass spectral study. Complexes 1 and 2 showed absorption bands at 500 and 535 nm, respectively. The calf thymus DNA melting study revealed their interaction through DNA crosslinking on exposure to light which was further confirmed from the alkaline agarose gel electrophoresis using plasmid supercoiled pUC19 DNA. Complex 2 showed disruption of the mitochondrial membrane potential in the JC-1 (1,1',3,3'-tetraethyl-5,5',6,6'-tetrachloroimidacarbocyanine iodide) assay. The complexes were photocytotoxic in visible light (400-700 nm, power: 10 J cm-2) in cervical cancer HeLa and breast cancer MCF-7 cells. Complex 2 having a photoactive diiodo‑boron-dipyrromethene moiety gave a singlet oxygen quantum yield (ΦΔ) value of ~0.6. It showed singlet oxygen mediated apoptotic photodynamic therapy activity with remarkably low IC50 (half maximal inhibitory concentration) value of ~0.15 μM. The cis-disposition of chlorides gave a cis-divacant 4-coordinate intermediate structure from the density functional theory (DFT) study thus mimicking the DNA crosslinking property of cisplatin.
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Study of the effect of external noise pickups on the performance of a cryogenic bolometer. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:096104. [PMID: 31575278 DOI: 10.1063/1.5115595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 08/26/2019] [Indexed: 06/10/2023]
Abstract
This paper reports the detailed noise characterization, investigation of various noise sources, and its mitigation to improve the performance of a cryogenic bolometer detector for the TIN.TIN experiment. The noise spectrum has been measured for a sapphire bolometer test setup with an indigenously developed neutron transmutation doped Ge sensor in the cryogen free dilution refrigerator system at Mumbai. The effect of external noise, arising either from ground loops in the system or from the diagnostic and control electronics of the cryostat, on the performance of the bolometer is assessed. A systematic comparison of the influence of different noise pickups on the bolometer resolution is also presented. The best-achieved resolution (σE) at 15 mK is ∼15 keV for heater pulses and appears to be mainly limited by the noise due to the pulse tube cryocooler.
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Correction to Curcumin “Drug” Stabilized in Oxidovanadium(IV)-BODIPY Conjugates for Mitochondria-Targeted Photocytotoxicity. Inorg Chem 2019; 58:8893. [DOI: 10.1021/acs.inorgchem.9b00931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Photochemotherapy of Infrared Active BODIPY-Appended Iron(III) Catecholates for in Vivo Tumor Growth Inhibition. ACS OMEGA 2018; 3:9333-9338. [PMID: 31459066 PMCID: PMC6644825 DOI: 10.1021/acsomega.8b01001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 08/01/2018] [Indexed: 05/07/2023]
Abstract
Iron(III) catecholates of BODIPY (boron-dipyrromethene)-conjugated dipicolylamine ligands, viz. [Fe(L1)(cat)Cl] (1) and [Fe(L2)(cat)Cl] (2) (H2cat = catechol), with a ligand-to-metal charge transfer band at ∼800 nm were studied for their in vivo activity in dark and infrared light in luciferase-expressing human breast adenocarcinoma (BT474luc) cells. Complex 2 displayed in vitro photocytotoxicity in BT474luc cells (IC50: 6 μM) in infrared light of 600-720 nm with moderate dark toxicity (IC50: 18 μM) as evidenced from the MTT and Annexin-V FITC/PI staining assays. The mitochondria-localizing complexes showed apoptotic cell death involving reactive oxygen species whose generation was evidenced from 2,7-dichlorofluorescein diacetate assay. In vivo studies showed tumor growth inhibition in mice with an optimized complex 2 dose of 5 mg per kg body weight on exposure to infrared light of 685 nm (dose of 20 mW/cm2). The in vivo results exemplify complex 2 as a unique iron-based infrared-active photochemotherapeutic agent.
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Iron(III) Complexes of Vitamin B6
Schiff Base with Boron-Dipyrromethene Pendants for Lysosome-Selective Photocytotoxicity. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201701487] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Synthesis, Theory and In Vitro Photodynamic Activities of New Copper(II)-Histidinito Complexes. ChemistrySelect 2018. [DOI: 10.1002/slct.201800015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Glucose-Appended Platinum(II)-BODIPY Conjugates for Targeted Photodynamic Therapy in Red Light. Inorg Chem 2018; 57:1717-1726. [PMID: 29400953 DOI: 10.1021/acs.inorgchem.7b02249] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Platinum(II) complexes [Pt(L1)(R-BODIPY)]Cl (1) and [Pt(L2)(R-BODIPY)]Cl (2), where R-BODIPY is 8-(4-ethynylphenyl)-distyryl-4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3, L1 is 4'-phenyl-2,2':6',2″-terpyridine, and L2 is (2,2':6',2″-terpyridin-4'-oxy)ethyl-β-d-glucopyranoside, were synthesized and characterized, and their photocytotoxicity was studied. The phenylacetylide complex [Pt(L1)(C≡CPh)]Cl (3) was prepared and used as a control. Complexes 1 and 2 showed near-IR absorption bands at 713 nm (ε = 3.47 × 104 M-1 cm-1) and 715 nm (3.2 × 104 M-1 cm-1) in 10% dimethyl sulfoxide (DMSO)-Dulbecco's Modified Eagle's Medium (DMEM) (pH 7.2). The BODIPY complexes are emissive in 10% DMSO-DMEM at pH 7.2 with λem (λex, Φf) = 822 nm (710 nm, 0.022) for complex 1 and λem (λex, Φf) = 825 nm (710 nm, 0.026) for complex 2. They generated singlet oxygen (1O2) in red light as evidenced from 1,3-diphenylisobenzofuran (DPBF) titration experiments. The singlet oxygen quantum yield (ΦΔ) values for 1 and 2 were ∼0.6 signifying their photosensitizing ability. They were remarkably photodynamic therapy (PDT) active in red light showing significant red light-induced cytotoxicity in cervical HeLa, lung cancer A549, and breast cancer MCF-7 cells (IC50: 2.3-24.7 μM in light) with negligible dark toxicity (IC50 > 100 μM). A significant enhancement in cellular uptake was observed for 2 having glucose-appended terpyridine ligand compared to 1. The confocal microscopy showed significant mitochondrial localization of the complexes as evidenced from the JC-1 assay. The complexes released the photoactive R-BODIPY ligand upon red light-irradiation as evidenced from the mass and 1H NMR spectral studies. Complex 2 is remarkable in satisfying the essential requirements of targeted PDT in red light.
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Mitochondria-localizing BODIPY–copper(ii) conjugates for cellular imaging and photo-activated cytotoxicity forming singlet oxygen. Dalton Trans 2018; 47:5019-5030. [DOI: 10.1039/c8dt00255j] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
BODIPY–copper(ii) conjugates are prepared and characterized and the complexes showed mitochondrial localization with singlet oxygen mediated visible light-induced apoptotic cell death.
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Mitochondria-Targeted Anticancer Activity of BODIPY-Appended Iron(III) Catecholates in Red Light. ChemistrySelect 2017. [DOI: 10.1002/slct.201702166] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Curcumin "Drug" Stabilized in Oxidovanadium(IV)-BODIPY Conjugates for Mitochondria-Targeted Photocytotoxicity. Inorg Chem 2017; 56:12457-12468. [PMID: 28972748 DOI: 10.1021/acs.inorgchem.7b01924] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Ternary oxidovanadium(IV) complexes of curcumin (Hcur), dipicolylamine (dpa) base, and its derivatives having pendant noniodinated and di-iodinated boron-dipyrromethene (BODIPY) moiety (L1 and L2, respectively), namely, [VO(dpa)(cur)]ClO4 (1), [VO(L1)(cur)]ClO4 (2), and [VO(L2)(cur)]ClO4 (3) and their chloride salts (1a-3a) were prepared, characterized, and studied for anticancer activity. The chloride salts were used for biological studies due to their aqueous solubility. Complex 1 was structurally characterized by single-crystal X-ray crystallography. The complex has a VO2+ moiety bound to dpa ligand showing N,N,N-coordination in a facial mode, and curcumin is bound in its mono-anionic enolic form. The V-O(cur) distances are 1.950(18) and 1.977(16) Å, while the V-N bond lengths are 2.090(2), 2.130(2), and 2.290(2) Å. The bond trans to V═O is long due to trans effect. The complexes are stable in a solution phase over a long period of time of 48 h without showing any apparent degradation of the curcumin ligand. The diiodo-BODIPY ligand (L2) or Hcur alone showed limited solution stability in dark. The emissive BODIPY (L1) containing complex 2a showed preferential mitochondrial localization in MCF-7 cells in cellular imaging experiments. The cytotoxicity of the complexes was studied by MTT assay. The BODIPY complex 3a showed excellent photodynamic therapy effect in visible light (400-700 nm) giving IC50 values of 2-6 μM in HeLa and MCF-7 cancer cells, while being less toxic in dark (∼100 μM). The cell death was apoptotic in nature involving reactive oxygen species (ROS). Mechanistic data from pUC19 DNA photocleavage studies revealed photogenerated ROS as primarily 1O2 from the BODIPY moiety and ·OH radicals from the curcumin ligand.
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Monofunctional BODIPY-Appended Imidazoplatin for Cellular Imaging and Mitochondria-Targeted Photocytotoxicity. Inorg Chem 2017; 56:11019-11029. [PMID: 28846407 DOI: 10.1021/acs.inorgchem.7b01346] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Monofunctional platinum(II) complexes of formulation cis-[Pt(NH3)2(L)Cl](NO3), where L is an imidazole base conjugated to 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) with emissive (L1 in 1) and nonemissive (L2 in 2) moieties were prepared and characterized, and their singlet oxygen-mediated photoinduced cytotoxicity was studied. The 1-methylimidazole (1-MeIm) complex 3 was prepared as a control and for structural characterization by X-ray crystallography. Complexes 1 and 2 showed strong visible absorption bands at 500 nm (ε = 2.7 × 104 M-1 cm-1) and 540 nm (1.4 × 104 M-1 cm-1). Complex 1 is emissive with a band at 510 nm (ΦF = 0.09) in 1% dimethyl sulfoxide/Dulbecco's Modified Eagle's Medium (pH 7.2). Singlet oxygen generation upon photoirradiation with visible light (400-700 nm) was evidenced from 1,3-diphenylisobenzofuran titration experiments showing significant photosensitizing ability of the BODIPY complexes. Both 1 and 2 were remarkably photocytotoxic in visible light (400-700 nm, 10 J cm-2) in skin keratinocyte HaCaT and breast cancer MCF-7 cells giving IC50 values in nanomolar concentration. The complexes were, however, essentially nontoxic to the cells in the dark (IC50 > 80 μM). Complex 2 having a diiodo-BODIPY unit is nonemissive but an efficient photosensitizer with high singlet oxygen generation ability in visible light (400-700 nm). Confocal microscopy using the emissive complex 1 showed significant mitochondrial localization of the complex. Cell death via apoptotic pathway was observed from the Annexin-V-FITC/PI assay. The formation of Pt-DNA adducts was evidenced from the binding experiments of the complexes 1 and 2 with 9-ethylguanine as a model nucleobase from 1H NMR and mass spectral studies.
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A Complementary Aggregation Induced Emission Pair for Generating White Light and Four-Colour (RGB and Near-IR) Cell Imaging. CHEMPHOTOCHEM 2017. [DOI: 10.1002/cptc.201700030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Cover Picture: A Complementary Aggregation Induced Emission Pair for Generating White Light and Four-Colour (RGB and Near-IR) Cell Imaging (ChemPhotoChem 3/2017). CHEMPHOTOCHEM 2017. [DOI: 10.1002/cptc.201700031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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A Complementary Aggregation Induced Emission Pair for Generating White Light and Four-Colour (RGB and Near-IR) Cell Imaging. CHEMPHOTOCHEM 2017. [DOI: 10.1002/cptc.201600032] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Photorelease and Cellular Delivery of Mitocurcumin from Its Cytotoxic Cobalt(III) Complex in Visible Light. Inorg Chem 2016; 55:6027-35. [DOI: 10.1021/acs.inorgchem.6b00554] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
Microbial secretion of siderophores for iron uptake can be employed as an efficient strategy to smuggle in bactericidal agents by conjugation to iron.
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Cellular imaging and mitochondria targeted photo-cytotoxicity in visible light by singlet oxygen using a BODIPY-appended oxovanadium(iv) DNA crosslinking agent. MEDCHEMCOMM 2016. [DOI: 10.1039/c6md00071a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Targeted PDT by1O2at mtDNA crosslinking site of a BODIPY-appended VO2+complex in visible light.
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Iron(III) salicylates of dipicolylamine bases showing photo-induced anticancer activity and cytosolic localization. Polyhedron 2015. [DOI: 10.1016/j.poly.2015.10.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Morphology, Structure, Rheology, and Thermodynamics of Piezoelectric Poly(vinylidene fluoride)−Ethylene Carbonate Thermoreversible Gel. Macromolecules 2008. [DOI: 10.1021/ma7021502] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
The influence of Mn2+, Fe3+, Co2+, and Zn2+ ions on the extent of trypsinogen activation has been determined for several ion concentrations at pH 7.4 and 36.4 degrees C. For the Mn2+ ion also the autocatalytic rate constants have been detected. The effect of Ca2+ has been reinvestigated for comparison purposes. The apparent dissociation constants of KMn2+ = 0.01 (M) and KCa2+ = 0.02 (M) have been found for the given metal ion-trypsinogen complexes. For Co2+ ion, however, only a slight effect and for Fe3+ and Zn2+ ions no significant effect could be detected on trypsinogen activation. The investigated ions are of empty, open, and completed d subshells of electrons and they are different also in their ionic size. The differences in effects of the ions are discussed on the basis of these factors.
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Abstract
The effect of Mn2+ and Ca2+ ions on the rate of trypsin autolysis was studied at pH 7.0 and at 34.4-60.2 degrees C. For comparison, the kinetic constants of esterolytic activity of trypsin in the presence of the metal ion were determined at pH 7.4 and at 36 degrees and 40 degrees C. There was no significant difference in the rate of autolysis between Mn2+ and Ca2+ in the temperature range 34-47 degrees C, but at 56.8 degrees and 60.2 degrees autolysis was slightly more rapid in the presence of Mn2+. The Mn2+ or Ca2+ ion bound to trypsin is supposed to control the conformation and thereby the stability and the activity of the enzyme. The indirect effect of Mn2+ and Ca2+ is discussed on a structural basis of the enzyme molecule.
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