Rhein-based necrosis-avid MRI contrast agents for early evaluation of tumor response to microwave ablation therapy

PURPOSE: Early evaluation of tumor response to thermal ablation therapy can help identify untreated tumor cells and then perform repeated treatment as soon as possible. The purpose of this work was to explore the potential of rhein-based necrosis-avid contrast agents (NACAs) for early evaluation of tumor response to microwave ablation (MWA). METHODS: 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay was performed to test the cytotoxicity of rhein-based NACAs against HepG2 cells. Rat models of liver MWA were used for investigating the effectiveness of rhein-based NACAs in imaging the MWA lesion, the optimal time period for post-MWA MRI examination, and the metabolic behaviors of 68 Ga-labeled rhein-based NACAs. Rat models of orthotopic liver W256 tumor MWA were used for investigating the time window of rhein-based NACAs for imaging the MWA lesion, the effectiveness of these NACAs in distinguishing the residual tumor and the MWA lesion, and their feasibility in early evaluating the tumor response to MWA. RESULTS: Gadolinium 2,2',2''-(10-(2-((4-(4,5-Dihydroxy-9,10-dioxo-9,10-dihydroanthracene-2-carboxamido)butyl)amino)-2-oxoethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triyl)triacetic acid (GdL2 ) showed low cytotoxicity and high quality in imaging the MWA region. The optimal time period for post-MWA MRI examination using GdL2 was 2 to 24 h after the treatment. During 2.5 to 3.5 h postinjection, GdL2 can better visualize the MWA lesion in comparison with gadolinium 2-[4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododec-1-yl]acetic acid (Gd-DOTA), and the residual tumor would not be enhanced. The tumor response to MWA as evaluated by using GdL2 -enhanced MRI was consistent with histological examination. CONCLUSION: GdL2 appears to be a promising NACA for the tumor response assessment after thermal ablation therapies.status: publishe

Synthesis and Evaluation of Diindole-Based MRI Contrast Agent for In Vivo Visualization of Necrosis

PURPOSE: Noninvasive imaging of cell necrosis can provide an early evaluation of tumor response to treatments. Here, we aimed to design and synthesize a novel diindole-based magnetic resonance imaging (MRI) contrast agent (Gd-bis-DOTA-diindolylmethane, Gd-DIM) for assessment of tumor response to therapy at an early stage. PROCEDURES: The oil-water partition coefficient (Log P) and relaxivity of Gd-DIM were determined in vitro. Then, its necrosis avidity was examined in necrotic cells in vitro and in rat models with microwave ablation-induced muscle necrosis (MAMN) and ischemia reperfusion-induced liver necrosis (IRLN) by MRI. Visualization of tumor necrosis induced by combretastatin A-4 disodium phosphate (CA4P) was evaluated in rats bearing W256 orthotopic liver tumor by MRI. Finally, DNA binding assay was performed to explore the possible necrosis-avidity mechanism of Gd-DIM. RESULTS: The Log P value and T1 relaxivity of Gd-DIM is - 2.15 ± 0.01 and 6.61 mM-1 s-1, respectively. Gd-DIM showed predominant necrosis avidity in vitro and in vivo. Clear visualization of the tumor necrosis induced by CA4P was achieved at 60 min after administration of Gd-DIM. DNA binding study indicated that the necrosis-avidity mechanism of Gd-DIM may be due to its binding to exposed DNA in necrotic cells. CONCLUSION: Gd-DIM may serve as a promising necrosis-avid MRI contrast agent for early assessment of tumor response to therapy.status: publishe

Thermoelectric Silver‐Based Chalcogenides

Abstract Heat is abundantly available from various sources including solar irradiation, geothermal energy, industrial processes, automobile exhausts, and from the human body and other living beings. However, these heat sources are often overlooked despite their abundance, and their potential applications remain underdeveloped. In recent years, important progress has been made in the development of high‐performance thermoelectric materials, which have been extensively studied at medium and high temperatures, but less so at near room temperature. Silver‐based chalcogenides have gained much attention as near room temperature thermoelectric materials, and they are anticipated to catalyze tremendous growth in energy harvesting for advancing internet of things appliances, self‐powered wearable medical systems, and self‐powered wearable intelligent devices. This review encompasses the recent advancements of thermoelectric silver‐based chalcogenides including binary and multinary compounds, as well as their hybrids and composites. Emphasis is placed on strategic approaches which improve the value of the figure of merit for better thermoelectric performance at near room temperature via engineering material size, shape, composition, bandgap, etc. This review also describes the potential of thermoelectric materials for applications including self‐powering wearable devices created by different approaches. Lastly, the underlying challenges and perspectives on the future development of thermoelectric materials are discussed

Transverse polarisation measurement of Λ\Lambda hyperons in ppNe collisions at sNN\sqrt{s_{NN}}=68.4 GeV with the LHCb detector

A measurement of the transverse polarization of the $\Lambda$ and $\bar{\Lambda}$hyperons in $p$Ne fixed-target collisions at $\sqrt{s_{NN}}$=68.4 GeV is presented using data collected by the LHCb detector. The polarization is studied using the decay $\Lambda \rightarrow p \pi^-$ together with its charge conjugated process, the integrated values measured are $$P_{\Lambda} = 0.029 \pm 0.019 \, (\rm{stat}) \pm 0.012 \, (\rm{syst}) \, ,$$ $$P_{\bar{\Lambda}} = 0.003 \pm 0.023 \, (\rm{stat}) \pm 0.014 \,(\rm{syst}) \,$$ Furthermore, the results are shown as a function of the Feynman $x$ variable, transverse momentum, pseudorapidity and rapidity of the hyperons, and are compared with previous measurements.A measurement of the transverse polarization of the $\Lambda$ and $\bar{\Lambda}$ hyperons in $p$Ne fixed-target collisions at $\sqrt{s_{NN}}$ = 68.4 GeV is presented using data collected by the LHCb detector. The polarization is studied using the decay $\Lambda \rightarrow p \pi^-$ together with its charge conjugated process, the integrated values measured are $$P_{\Lambda} = 0.029 \pm 0.019 \, (\rm{stat}) \pm 0.012 \, (\rm{syst}) \, ,$$ $$P_{\bar{\Lambda}} = 0.003 \pm 0.023 \, (\rm{stat}) \pm 0.014 \,(\rm{syst}) \,.$$ Furthermore, the results are shown as a function of the Feynman~$x$~variable, transverse momentum, pseudorapidity and rapidity of the hyperons, and are compared with previous measurements

Comprehensive analysis of local and nonlocal amplitudes in the B0→K∗0μ+μ−B^0 \to K^{*0} \mu^+\mu^- decay

A comprehensive study of the local and nonlocal amplitudes contributing to the decay $B^0\rightarrow K^{*0}(\to K^+\pi^-) \mu^+\mu^-$ is performed by analysing the phase-space distribution of the decay products. The analysis is based on $pp$ collision data corresponding to an integrated luminosity of 8.4fb$^{-1}$ collected by the LHCb experiment. This measurement employs for the first time a model of both one-particle and two-particle nonlocal amplitudes, and utilises the complete dimuon mass spectrum without any veto regions around the narrow charmonium resonances. In this way it is possible to explicitly isolate the local and nonlocal contributions and capture the interference between them. The results show that interference with nonlocal contributions, although larger than predicted, only has a minor impact on the Wilson Coefficients determined from the fit to the data. For the local contributions, the Wilson Coefficient $C_9$, responsible for vector dimuon currents, exhibits a $2.1\sigma$ deviation from the Standard Model expectation. The Wilson Coefficients $C_{10}$, $C_{9}'$ and $C_{10}'$ are all in better agreement than $C_{9}$ with the Standard Model and the global significance is at the level of $1.5\sigma$. The model used also accounts for nonlocal contributions from $B^{0}\to K^{*0}\left[\tau^+\tau^-\to \mu^+\mu^-\right]$ rescattering, resulting in the first direct measurement of the $b s\tau\tau$ vector effective-coupling $C_{9\tau}$.A comprehensive study of the local and nonlocal amplitudes contributing to the decay $B^0\rightarrow K^{*0}(\to K^+\pi^-) \mu^+\mu^-$ is performed by analysing the phase-space distribution of the decay products. The analysis is based on \proton\proton collision data corresponding to an integrated luminosity of 8.4fb$^{-1}$ collected by the LHCb experiment. This measurement employs for the first time a model of both one-particle and two-particle nonlocal amplitudes, and utilises the complete dimuon mass spectrum without any veto regions around the narrow charmonium resonances. In this way it is possible to explicitly isolate the local and nonlocal contributions and capture the interference between them. The results show that interference with nonlocal contributions, although larger than predicted, only has a minor impact on the Wilson Coefficients determined from the fit to the data. For the local contributions, the Wilson Coefficient $C_9$, responsible for vector dimuon currents, exhibits a $2.1\sigma$ deviation from the Standard Model expectation. The Wilson Coefficients $C_{10}$, $C_{9}'$ and $C_{10}'$ are all in better agreement than $C_{9}$ with the Standard Model and the global significance is at the level of $1.5\sigma$. The model used also accounts for nonlocal contributions from $B^{0}\to K^{*0}\left[\tau^+\tau^-\to \mu^+\mu^-\right]$ rescattering, resulting in the first direct measurement of the $b s\tau\tau$ vector effective-coupling $C_{9\tau}$

Study of b−b-hadron decays to Λc+h−h′−\Lambda_c^+h^-h^{\prime -} final states

Decays of $\Xi_{b}^{-}$ and $\Omega_{b}^{-}$ baryons to $\Lambda_{c}^{+} h^- h^{\prime -}$ final states, with $h^- h^{\prime -}$ being $\pi^{-}\pi^{-}$, $K^{-}\pi^{-}$ and $K^{-}K^{-}$ meson pairs, are searched for using data collected with the LHCb detector. The data sample studied corresponds to an integrated luminosity of $8.7 \rm fb^{-1}$ of $pp$ collisions collected at centre-of-mass energies $\sqrt{s} = 7$, $8$ and $13 \rm TeV$. The products of the relative branching fractions and fragmentation fractions for each signal mode, relative to the $B^{-} \rightarrow \Lambda_{c}^{+} \bar{p} \pi^{-}$ mode, are measured, with $\Xi_{b}^{-} \rightarrow\Lambda_{c}^{+} K^{-} \pi^{-}$, $\Xi_{b}^{-} \rightarrow\Lambda_{c}^{+} K^{-} K^{-}$ and $\Omega_{b}^{-} \rightarrow\Lambda_{c}^{+} K^{-} K^{-}$ decays being observed at over $5\,\sigma$ significance. The $\Xi_{b}^{-} \rightarrow\Lambda_{c}^{+} K^{-} \pi^{-}$ mode is also used to measure the $\Xi_{b}^{-}$ production asymmetry, which is found to be consistent with zero. In addition, the $B^{-} \rightarrow \Lambda_{c}^{+} \bar{p} K^{-}$ decay is observed for the first time, and its branching fraction is measured relative to that of the $B^{-} \rightarrow \Lambda_{c}^{+} \bar{p} \pi^{-}$ mode.Decays of $\Xi_b^-$ and $\Omega_b^-$ baryons to $\Lambda_c^+ h^- h^{\prime -}$ final states, with $h^- h^{\prime -}$ being $\pi^-\pi^-$, $K^-\pi^-$ and $K^-K^-$ meson pairs, are searched for using data collected with the LHCb detector. The data sample studied corresponds to an integrated luminosity of $8.7\,\mathrm{fb}^{-1}$ of $pp$ collisions collected at centre-of-mass energies $\sqrt{s} = 7$, $8$ and $13\,\mathrm{Te\kern -0.1em V}$. The products of the relative branching fractions and fragmentation fractions for each signal mode, relative to the $B^- \to \Lambda_c^+ \overline{p} \pi^-$ mode, are measured, with $\Xi_{b}^- \to\Lambda_{c}^+ K^- \pi^-$, $\Xi_{b}^- \to\Lambda_{c}^+ K^- K^-$ and $\Omega_{b}^- \to\Lambda_{c}^+ K^- K^-$ decays being observed at over $5\,\sigma$ significance. The $\Xi_{b}^- \to\Lambda_{c}^+ K^- \pi^-$ mode is also used to measure the $\Xi_{b}^-$ production asymmetry, which is found to be consistent with zero. In addition, the $B^- \to \Lambda_{c}^+ \overline{p} K^-$ decay is observed for the first time, and its branching fraction is measured relative to that of the $B^- \to \Lambda_{c}^+ \overline{p} \pi^-$ mode