Stimuli‐responsive materials that can be reversibly switched by light are of immense interest. Among them, photo‐responsive spin crossover (SCO) complexes have great promises to combine the ...photoactive inputs with multifaceted outputs into switchable materials and devices. However, the reversible control the spin‐state change by photochromic guests is still challenging. Herein, we report an unprecedented guest‐driven light‐induced spin change (GD‐LISC) in a Hofmann‐type metal–organic framework (MOF), Fe(bpn){Ag(CN)2}2⋅azobenzene. (1, bpn=1,4‐bis(4‐pyridyl)naphthalene). The reversible trans–cis photoisomerization of azobenzene guest upon UV/Vis irradiation in the solid‐state results in the remarkable magnetic changes in a wide temperature range of 10–180 K. This finding not only establishes a new switching mechanism for SCO complexes, but also paves the way toward the development of new generation of photo‐responsive magnetic materials.
Guest‐driven light‐induced spin change (GD‐LISC) was firstly realized in a Hofmann‐type metal–organic framework with photochromic azobenzene guests.
Combining Ising‐type magnetic anisotropy with collinear magnetic interactions in single‐molecule magnets (SMMs) is a significant synthetic challenge. Herein we report a Dy15‐MCCu‐5 (1‐Dy) SMM, where ...a DyIII ion is held in a central pseudo‐D5h pocket of a rigid and planar Cu5 metallacrown (MC). Linking two Dy15‐MCCu‐5 units with a single hydroxide bridge yields the double‐decker {Dy15‐MCCu‐5}2 (2‐Dy) SMM where the anisotropy axes of the two DyIII ions are nearly collinear, resulting in magnetic relaxation times for 2‐Dy that are approximately 200 000 times slower at 2 K than for 1‐Dy in zero external field. Whereas 1‐Dy and the YIII‐diluted Dy@2‐Y analogue do not show remanence in magnetic hysteresis experiments, the hysteresis data for 2‐Dy remain open up to 6 K without a sudden drop at zero field. In conjunction with theoretical calculations, these results demonstrate that the axial ferromagnetic Dy–Dy coupling suppresses fast quantum tunneling of magnetization (QTM). The relaxation profiles of both complexes curiously exhibit three distinct exponential regimes, and hold the largest effective energy barriers for any reported d–f SMMs up to 625 cm−1.
The magnetic hysteresis of a metallacrown magnet opens after introducing axial ferromagnetic by linking two mono‐decker Dy15‐MCCu‐5 units with a single hydroxide bridge to give the double‐decker {Dy15‐MCCu‐5}2 single‐molecule magnet in which the anisotropy axes of the two DyIII ions are nearly collinear and the magnetic relaxation times are approximately 200 000 times slower than for the mono‐decker unit.
Among responsive multistable materials, spin crossover (SCO) systems are of particular interest for stabilizing multiple spin states with various stimulus inputs and physical outputs. Here, in a 2D ...Hofmann-type coordination polymer, Fe(isoq)
2
{Au(CN)
2
}
2
(isoq = isoquinoline), a medium-temperature annealing process is introduced after light/temperature stimulation, which accesses the hidden multistability of the spin state. With the combined effort of magnetic, crystallographic and Mössbauer spectral investigation, these distinct spin states are identified and the light- and temperature-assisted transition pathways are clarified. Such excitation-relaxation and trapping-relaxation joint mechanisms, as ingenious interplays between the kinetic and thermodynamic effects, uncover hidden possibilities for the discovery of multistable materials and the development of multistate intelligent devices.
Two new two-stage manipulation protocols, namely light- and temperature-assisted spin state annealing (LASSA/TASSA), are applied to a spin crossover coordination polymer, Fe(isoq)
2
{Au(CN)
2
}
2
, revealing the hidden multistability of spin states.
Background
High‐ and low‐risk endometrial cancer (EC) differ in whether lymphadenectomy is performed. Assessment of high‐risk EC is essential for planning surgery appropriately.
Purpose
To develop a ...radiomics nomogram for high‐risk EC prediction preoperatively.
Study Type
Retrospective.
Population
In all, 717 histopathologically confirmed EC patients (mean age, 56 years ± 9) divided into a primary group (394 patients from Center A), validation groups 1 and 2 (146 patients from Center B and 177 patients from Centers C–E).
Field Strength/Sequence
1.5/3T scanners; T2‐weighted imaging, diffusion‐weighted imaging, apparent diffusion coefficient, and contrast enhancement sequences.
Assessment
A radiomics nomogram was generated by combining the selected radiomics features and clinical parameters (metabolic syndrome, cancer antigen 125, age, tumor grade following curettage, and tumor size). The area under the curve (AUC) of the receiver operator characteristic was used to evaluate the predictive performance of the radiomics nomogram for high‐risk EC. The surgical procedure suggested by the nomogram was compared with the actual procedure performed for the patients. Net benefit of the radiomics nomogram was evaluated by a clinical decision curve (CDC), net reclassification index (NRI), and integrated discrimination improvement (IDI).
Statistical Tests
Binary least absolute shrinkage and selection operator (LASSO) logistic regression, linear regression, and multivariate binary logistic regression were used to select radiomics features and clinical parameters.
Results
The AUC for prediction of high‐risk EC for the radiomics nomogram in the primary group, validation groups 1 and 2 were 0.896 (95% confidence interval CI: 0.866–0.926), 0.877 (95% CI: 0.825–0.930), and 0.919 (95% CI: 0.879–0.960), respectively. The nomogram achieved good net benefit by CDC analysis for high‐risk EC. NRIs were 1.17, 1.28, and 1.51, and IDIs were 0.41, 0.60, and 0.61 in the primary group, validation groups 1 and 2, respectively.
Data Conclusion
The radiomics nomogram exhibited good performance in the individual prediction of high‐risk EC, and might be used for surgical management of EC.
Level of Evidence
4
Technical Efficacy Stage
2 J. MAGN. RESON. IMAGING 2020;52:1872–1882.
Abstract Unidirectional propagation of photons originated from perfect chirality meets the critical requirement for building a high-performance quantum network. However, it not only requires that the ...circular dipole emitter is precisely located at points of circularly polarized electric fields, which leads to non-reciprocal interactions for photons with opposite propagation directions, but also the light-emitter interaction strength should be strong enough to guarantee a π phase shift. Unfortunately, these perfect chirality points are scarce and accessible points with elliptically polarized fields result in non-ideal photon-emitter chiral interactions and emitters radiating photons bidirectionally. Meanwhile, reflection properties, phase shifts, and non-reciprocal interactions are sensitive to frequency detunings and dissipations. Here, without engineering the dipole and optimizing the distribution of the field, a scatter such as a nanotip placed at the evanescent field of a whispering gallery mode resonator (WGMR) is adopted to control the transporting properties of single photons under non-ideal chiral interactions. By properly adjusting the relative position between the nanotip and the atom or the overlap between the nanotip and the mode volume of the WGMR, amplitudes of reflected photons in different pathways are changed. Consequently, complete destructive interference appears and thus no photons are reflected. The corresponding phase shifts of π and non-reciprocal interactions are guaranteed simultaneously. Significantly, the perfect chirality reconstructed here is robust against frequency detunings and dissipations. Therefore, the atom-WGMR-nanotip structure can be regarded as a compound chiral atom with radiating photons in only one direction.
A series of α-triazolyl chalcones were efficiently synthesized. Most of the prepared compounds showed effective antibacterial and antifungal activities. Noticeably, α-triazolyl derivative 9a ...exhibited low MIC value of 4 μg/mL against MRSA and Micrococcus luteus, which was comparable or even superior to reference drugs. The further research revealed that compound 9a could effectively intercalate into Calf Thymus DNA to form 9a–DNA complex which might block DNA replication to exert their powerful antimicrobial activities. Competitive interactions between 9a and metal ions to Human Serum Albumin (HSA) suggested the participation of Fe3+, K+ and Mg2+ ions in 9a–HSA system could increase the concentration of free 9a, shorten its storage time and half-life in the blood, thus improving its antimicrobial efficacy.
Display omitted A series of α-triazolyl chalcones were synthesized and screened for their antimicrobial activities, further binding behavior with calf thymus DNA and human serum albumin was investigated.
•Synthesis and valuable antimicrobial potency of α-triazolyl chalcones.•Some prepared compounds were highly sensitive to MRSA.•Intercalation of 9a into DNA revealed to be responsible for antimicrobial activity.•α-Triazolyl chalcone 9a could be effectively stored and carried by HSA.•Some metal ions were found to increase the concentration of free compound 9a.
Here we reported the deuteration of the metal‐binding equatorial water molecules in a reported HoIII single‐molecule magnet (SMM) with pentagonal‐bipyramidal geometry, from Ho(CyPh2PO)2(H2O)53+ to ...Ho(CyPh2PO)2(D2O)53+. The hyperfine structures originating from the nuclear spin of 165HoIII can be clearly observed. Moreover, the resulting magnetization dynamics revealed the switch of the relative relaxation rates for the two isotope‐isomorphic complexes—respectively faster/slower at low/high temperature. The noticeable isotope effect arises from not only the paramagnetic metal center but also the diamagnetic ligands, which can be explained by the ab initio calculated tunnel splitting and the involvement of the super‐hyperfine interaction related to the difference in the nuclear spin number of protium (1H, I=1/2) and deuterium (2H, I=1).
We reported the nuclear‐spin driven magnetization dynamics involving both metal ion and the ligand, for first time, in two HoIII isomorphic single‐molecule magnets, where the behavior is originated from the super‐hyperfine interaction related to the difference in nuclear spin number of protium (I=1/2) and deuterium (I=1).
The first spin-crossover (SCO) complex with an organic-inorganic hybrid perovskite structure (PPN)Fe{Au(CN)
2
}
3
(
1
) is reported, which displays three-step SCO behaviour. The light-induced ...excited spin-state trapping measurement gives
T
0
= 134 K for a three-dimensional FeL
3
-type (L = bis-monodentate ligand) SCO complex. Moreover, spin-state dependent fluorescence is observed in
1
.
The first spin-crossover complex with an organic-inorganic hybrid perovskite structure is reported, which displays three-step spin-crossover, light-induced excited spin-state trapping and spin-state dependent fluorescence properties.
Single-molecule magnets (SMMs) are regarded as a class of promising materials for spintronic and ultrahigh-density storage devices. Tuning the magnetic dynamics of single-molecule magnets is a ...crucial challenge for chemists. Lanthanide ions are not only highly magnetically anisotropic but also highly sensitive to the changes in the coordination environments. We developed a feasible approach to understand parts of the magneto-structure correlations and propose to regulate the relaxation behaviors via rational design. A series of Co(II)-Dy(III)-Co(II) complexes were obtained using in situ synthesis; in this system of complexes, the relaxation dynamics can be greatly improved, accompanied with desolvation, via single-crystal to single-crystal transformation. The effective energy barrier can be increased from 293 cm(-1) (422 K) to 416 cm(-1) (600 K), and the tunneling relaxation time can be grown from 8.5 × 10(-4) s to 7.4 × 10(-2) s. These remarkable improvements are due to the change in the coordination environments of Dy(III) and Co(II). Ab initio calculations were performed to better understand the magnetic dynamics.
Macroautophagy/autophagy is a membrane-mediated intracellular degradation pathway, through which bulky cytoplasmic content is digested in lysosomes. How the autophagy initiation and maturation steps ...are regulated is not clear. In this study, we found an E3 ubiquitin ligase complex, linear ubiquitin chain assembly complex (LUBAC) and a deubiquitinating enzyme (DUB) OTULIN localize to the phagophore area to control autophagy initiation and maturation. LUBAC key component RNF31/HOIP translocates to the LC3 puncta area when autophagy is induced. RNF31 knockdown inhibits autophagy initiation, and cells are more sensitive to bacterial infection. OTULIN knockdown, however, promotes autophagy initiation but blocks autophagy maturation. In OTULIN knockdown cells, excessive ubiquitinated ATG13 protein was recruited to the phagophore for prolonged expansion, and therefore inhibits autophagosome maturation. Together, our study provides evidence that LUBAC and OTULIN cooperatively regulate autophagy initiation and autophagosome maturation by mediating the linear ubiquitination and the stabilization of ATG13.
Abbreviations: ATG: autophagy-related; CALCOCO2/NDP52: calcium binding and coiled-coil domain 2; CQ: chloroquine; CUL1-FBXL20: cullin 1-F-box and leucine rich repeat protein 20; CUL3-KLHL20: cullin 3-kelch like family member 20; CUL4-AMBRA1: cullin 4-autophagy and beclin 1 regulator 1; CYLD: CYLD lysine 63 deubiquitinase; DAPI: 4′,6-diamidino-2-phenylindole; DUB: deubiquitinating enzyme; EBSS: Earle's Balanced Salt Solution; GFP: green fluorescent protein; GST: glutathione S-transferase; IKBKG/NEMO: inhibitor of nuclear factor kappa B kinase regulatory subunit gamma; LUBAC: linear ubiquitin chain assembly complex; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3B; MIM: MIT-interacting motif; mRFP: monomeric red fluorescent protein; NEDD4: NEDD4 E3 ubiquitin protein ligase; NFKB: NF-kappaB complex; OPTN: optineurin; OTULIN: OTU deubiquitinase with linear linkage specificity; PIK3C3/Vps34: phosphatidylinositol 3-kinase catalytic subunit type 3; PtdIns: phosphatidylinositol; PtdIns3K: class III phosphatidylinositol 3-kinase complex; PtdIns3P: phosphatidylinositol 3-phosphate; RBCK1/HOIL1: RANBP2-type and C3HC4-type zinc finger containing 1; RB1CC1/FIP200: RB1-inducible coiled-coil 1; RIPK1: receptor interacting serine/threonine kinase 1; RNF216: ring finger protein 216; RNF31/HOIP: ring finger protein 31; RT-PCR: reverse transcriptase polymerase chain reaction; S. Typhimurium: Salmonella enterica serovar Typhimurium; SHARPIN: SHANK associated RH domain interactor; SMURF1: SMAD specific E3 ubiquitin protein ligase 1; SQSTM1: sequestosome 1; STING: stimulator of interferon response cGAMP interactor 1; STUB1/CHIP: STIP1 homology and U-box containing protein 1; TNF/TNF-alpha: tumor necrosis factor; TNFAIP3/A20: TNF alpha induced protein 3; TRAF6: TNF receptor associated factor 6; TRIM32: tripartite motif containing 32; UBAN: ubiquitin binding in TNIP/ABIN and IKBKG/NEMO proteins; ULK1/2: unc-51 like autophagy activating kinase 1/2; USP: ubiquitin specific peptidase; UVRAG: UV radiation resistance associated; VCPIP1: valosin containing protein interacting protein 1; WIPI2: WD repeat domain, phosphoinositide interacting protein 2; ZBTB16-CUL3-RBX1: zinc finger and BTB domain containing protein 16-cullin 3-ring-box 1; ZRANB1: zinc finger RANBP2-type containing 1.
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