Antibodies are an important component in host immune responses to viral pathogens. Because of their unique maturation process, antibodies can evolve to be highly specific to viral antigens. ...Physicians and researchers have been relying on such high specificity in their quest to understand host-viral interaction and viral pathogenesis mechanisms and to find potential cures for viral infection and disease. With more than 60 recombinant monoclonal antibodies developed for human use in the last 20 years, monoclonal antibodies are now considered a viable therapeutic modality for infectious disease targets, including newly emerging viral pathogens such as Ebola representing heightened public health concerns, as well as pathogens that have long been known, such as human cytomegalovirus. Here, we summarize some recent advances in identification and characterization of monoclonal antibodies suitable as drug candidates for clinical evaluation, and review some promising candidates in the development pipeline.
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.
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•Systematic summary of guest effects in spin-crossover Hofmann clathrates.•Molecular volume calculated by a convenient formula is applied to explore the size effect.•Strategies are ...discussed for optimizing the sensor property.
The incorporation of spin-crossover (SCO) properties into metal-organic frameworks (MOFs) is an appealing subclass of multifunctional MOFs with potential applications in molecular sensing. This review focuses on the design of SCO Hofmann-type MOFs, with emphasis on the guest effect on their SCO properties. The influences of guest size, dielectric constant, π⋯π interaction, hydrogen bonding interactions, weak X⋯M′ covalent bonding, and chemical reaction on the SCO properties of Hofmann-type MOFs are systematically explored. Further enhancements of sensing properties are also illustrated.
The first germole‐ligated single‐molecule magnets are reported, with contrasting properties found for the near‐linear sandwich complexes (η8‐COT)Ln(η5‐CpGe−, where Ln=Dy (1Dy) or Er (1Er), COT is ...cyclo‐octatetraenyl and CpGe is GeC4‐2,5‐(SiMe3)2‐3,4‐Me22−. Whereas 1Er has an energy barrier of 120(1) cm−1 in zero applied field and open hysteresis loops up to 10 K, the relaxation in 1Dy is characterized by quantum tunneling within the ground state.
Single‐molecule magnets: The first examples of germole‐ligated lanthanide single‐molecule magnets are reported, with markedly different properties found for the dysprosium and erbium versions.
We herein report a theoretical analysis based on a density functional theory/time‐dependent density functional theory (DFT/TDDFT) approach to understand the different phosphorescence efficiencies of ...a family of cyclometalated platinum(II) complexes: Pt(NCN)Cl (1; NCN=1,3‐bis(2‐pyridyl)phenyl−), Pt(CNN)Cl (2; CNN=6‐phenyl‐2,2′‐bipyridyl−), Pt(CNC)(CNPh) (3; CNC=2,6‐diphenylpyridyl2−), Pt(R‐CNN)Cl (4; R‐CNN=3‐(6′‐(2′′‐naphthyl)‐2′‐pyridyl)isoquinolinyl−), and Pt(R‐CNC)(CNPh) (5; R‐CNC=2,6‐bis(2′‐naphthyl)pyridyl2−). By considering both the spin–orbit coupling (SOC) and the electronic structures of these complexes at their respective optimized singlet ground (S0) and first triplet (${{\rm T}{{1\hfill \atop {\rm opt}\hfill}}}$) excited states, we were able to rationalize the experimental findings that 1) 1 is a strong emitter while its isomer 2 is only weakly emissive in CH2Cl2 solution at room temperature; 2) although the cyclometalated ligand of 3 has a higher ligand‐field strength than that of 1, 3 is nonemissive in CH2Cl2 solution at 298 K; and 3) extension of π conjugation at the lateral aryl rings of the cyclometalated ligands of 2 and 3 to give 4 and 5, respectively, leads to increased emission quantum yields under the same conditions. We found that Jahn–Teller and pseudo‐Jahn–Teller effects are operative in complexes 2 and 3, respectively, on going from the optimized S0 ground state to the optimized ${{\rm T}{{1\hfill \atop {\rm opt}\hfill}}}$ excited state, and thus lead to large excited‐state structural distortions and hence fast nonradiative decay. Furthermore, a strong‐field ligand may push the two different occupied d orbitals so far apart that the SOC effect is small and the radiative decay rate is slow. This work is an example of electronic‐structure‐driven tuning of the phosphorescence efficiency, and the DFT/TDDFT approach is demonstrated to be a versatile tool for the design of phosphorescent materials with target characteristics.
Don't flip out, emit! DFT calculations can explain the different phosphorescence efficiencies of a family of five structurally similar cyclometalated PtII complexes by considering spin–orbit coupling and electronic structures in the S0 ground and T1 excited states. For example, on going from the S0 to the T1 state, the lateral aryl rings of strongly emitting Pt(NCN)Cl (NCN=1,3‐bis(2‐pyridyl)phenyl−) remain coplanar, whereas those of its weakly emissive isomer Pt(CNN)Cl (CNN=6‐phenyl‐2,2′‐bipyridyl−) flip up due to Jahn–Teller distortion (see picture), which results in a large nonradiative decay rate
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.
Herein are described the synthesis, photophysical properties and applications of a series of luminescent cyclometalated AuIII complexes having an auxiliary aryl ligand. These complexes show ...photoluminescence with emission quantum yields of up to 0.79 in solution and 0.84 in thin films (4 wt % in PMMA) at room temperature, both of which are the highest reported values among AuIII complexes. Thermally activated delayed fluorescence (TADF) is the emission origin for some of these complexes. Solution‐processed OLEDs made with these complexes showed sky‐blue to green electroluminescence with external quantum efficiencies (EQEs) of up to 23.8 %, current efficiencies of up to 70.4 cd A−1, and roll‐off of down to 1 %, highlighting the bright prospect of AuIII‐TADF emitters in OLEDs.
Gold glows: Pincer AuIII aryl complexes give intense photoluminescence (PL) with emission quantum yields of up to 0.79 in solution and 0.84 in thin films. Some of them with N‐substituents based on donor–acceptor structures display stronger PL from thermally activated delayed fluorescence (TADF). The OLEDs fabricated with these TADF emitters exhibit high external quantum efficiencies (EQEs) over 23 % (ISC=intersystem crossing).
Abstract
In a retrospective study of 39 COVID-19 patients and 32 control participants in China, we collected clinical data and examined the expression of endothelial cell adhesion molecules by ...enzyme-linked immunosorbent assays. Serum levels of fractalkine, vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), and vascular adhesion protein-1 (VAP-1) were elevated in patients with mild disease, dramatically elevated in severe cases, and decreased in the convalescence phase. We conclude the increased expression of endothelial cell adhesion molecules is related to COVID-19 disease severity and may contribute to coagulation dysfunction.
Structurally robust tetradentate gold(III)‐emitters have potent material applications but are rare and unprecedented for those displaying thermally activated delayed fluorescence (TADF). Herein, a ...novel synthetic route leading to the preparation of highly emissive, charge‐neutral tetradentate C^C^N^C gold(III) complexes with 5‐5‐6‐membered chelate rings has been developed through microwave‐assisted C−H bond activation. These complexes show high thermal stability and with emission origin (3IL, 3ILCT, and TADF) tuned by varying the substituents of the C^C^N^C ligand. With phenoxazine/diphenylamine substituent, we prepared the first tetradentate gold(III) complexes that are TADF emitters with emission quantum yields of up to 94 % and emission lifetimes of down to 0.62 μs in deoxygenated toluene. These tetradentate AuIII TADF emitters showed good performance in vacuum‐deposited OLEDs with maximum EQEs of up to 25 % and LT95 of up to 5280 h at 100 cd m−2.
Gold(III) complexes supported by tetradentate ligands for OLEDs can be prepared under microwave conditions. Depending on the ligand substituents, these complexes exhibit short‐lived thermally activated delayed fluorescence (TADF) with quantum yields of up to 0.94.
Throw the switch: A new strategy for regulating spin crossover (SCO) properties by the control of an active guest molecule is proposed. As a proof of concept, maleic anhydride was incorporated into a ...microporous {Fe(pyrazine)Pt(CN)4} framework material and chemically switched to maleic acid, thus modifying the SCO properties (see picture).
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