Single-molecule magnets (SMMs) containing only one metal center may represent the lower size limit for molecule-based magnetic information storage materials. Their current drawback is that all SMMs ...require liquid-helium cooling to show magnetic memory effects. We now report a chemical strategy to access the dysprosium metallocene cation (Cp
)Dy(Cp*)
(Cp
, penta-iso-propylcyclopentadienyl; Cp
pentamethylcyclopentadienyl), which displays magnetic hysteresis above liquid-nitrogen temperatures. An effective energy barrier to reversal of the magnetization of
= 1541 wave number is also measured. The magnetic blocking temperature of
= 80 kelvin for this cation overcomes an essential barrier toward the development of nanomagnet devices that function at practical temperatures.
ion of a chloride ligand from the dysprosium metallocene (Cpttt)2DyCl (1Dy Cpttt=1,2,4‐tri(tert‐butyl)cyclopentadienide) by the triethylsilylium cation produces the first base‐free rare‐earth ...metallocenium cation (Cpttt)2Dy+ (2Dy) as a salt of the non‐coordinating B(C6F5)4− anion. Magnetic measurements reveal that 2DyB(C6F5)4 is an SMM with a record anisotropy barrier up to 1277 cm−1 (1837 K) in zero field and a record magnetic blocking temperature of 60 K, including hysteresis with coercivity. The exceptional magnetic axiality of 2Dy is further highlighted by computational studies, which reveal this system to be the first lanthanide SMM in which all low‐lying Kramers doublets correspond to a well‐defined MJ value, with no significant mixing even in the higher doublets.
SMMashing: A dysprosium(III) metallocenium cation is a single‐molecule magnet (SMM) with a record anisotropy barrier of 1277 cm−1 and record magnetic blocking up to 60 K, including hysteresis with coercivity.
The development of high-performance near-infrared organic light-emitting diodes is hindered by strong non-radiative processes as governed by the energy gap law. Here, we show that exciton ...delocalization, which serves to decouple the exciton band from highly vibrational ladders in the S0 ground state, can bring substantial enhancements in the photoluminescence quantum yield of emitters, bypassing the energy gap law. Experimental proof is provided by the design and synthesis of a series of new Pt(ii) complexes with a delocalization length of 5–9 molecules that emit at 866–960 nm with a photoluminescence quantum yield of 5–12% in solid films. The corresponding near-infrared organic light-emitting diodes emit light with a 930 nm peak wavelength and a high external quantum efficiency up to 2.14% and a radiance of 41.6 W sr−1 m−2. Both theoretical and experimental results confirm the exciton–vibration decoupling strategy, which should be broadly applicable to other well-aligned molecular solids.Pt(ii) complexes allow the fabrication of efficient near-infrared organic light-emitting diodes that operate beyond the 900 nm region.
•The cryogenic magnetocaloric effect in different magnetic systems is discussed.•The assembly strategies toward 3d-, 4f- and 3d–4f based molecular magnetic coolants are described.•The recent advance ...in cryogenic molecular magnetic coolants is summarized.•The different nature of 3d and 4f ions must be considered in the design of molecular magnetic coolants.
This review outlines recent advances in the design of 3d-, 4f-, and 3d–4f type magnetic molecules for use as excellent cryogenic magnetic coolants based on the magnetocaloric effect (MCE), and the structure-magnetocaloric correlations of reported molecular coolants. Further improvements in the MCE values of molecular magnetic materials are also proposed based on assembly strategies from molecular chemistry and crystal engineering.
In coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the relationship between disease severity and the host immune response is not ...fully understood. Here we performed single-cell RNA sequencing in peripheral blood samples of 5 healthy donors and 13 patients with COVID-19, including moderate, severe and convalescent cases. Through determining the transcriptional profiles of immune cells, coupled with assembled T cell receptor and B cell receptor sequences, we analyzed the functional properties of immune cells. Most cell types in patients with COVID-19 showed a strong interferon-α response and an overall acute inflammatory response. Moreover, intensive expansion of highly cytotoxic effector T cell subsets, such as CD4
effector-GNLY (granulysin), CD8
effector-GNLY and NKT CD160, was associated with convalescence in moderate patients. In severe patients, the immune landscape featured a deranged interferon response, profound immune exhaustion with skewed T cell receptor repertoire and broad T cell expansion. These findings illustrate the dynamic nature of immune responses during disease progression.
The coronavirus disease 2019 (COVID-19) pandemic presents an unprecedented threat to global public health. Herein, we utilized a combination of targeted and untargeted tandem mass spectrometry to ...analyze the plasma lipidome and metabolome in mild, moderate, and severe COVID-19 patients and healthy controls. A panel of 10 plasma metabolites effectively distinguished COVID-19 patients from healthy controls (AUC = 0.975). Plasma lipidome of COVID-19 resembled that of monosialodihexosyl ganglioside (GM3)-enriched exosomes, with enhanced levels of sphingomyelins (SMs) and GM3s, and reduced diacylglycerols (DAGs). Systems evaluation of metabolic dysregulation in COVID-19 was performed using multiscale embedded differential correlation network analyses. Using exosomes isolated from the same cohort, we demonstrated that exosomes of COVID-19 patients with elevating disease severity were increasingly enriched in GM3s. Our work suggests that GM3-enriched exosomes may partake in pathological processes related to COVID-19 pathogenesis and presents the largest repository on the plasma lipidome and metabolome distinct to COVID-19.
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•Quantitative lipidomic and metabolomic profiling of COVID-19 plasma•Plasma metabolite panel distinguished COVID-19 from healthy controls (AUC = 0.975)•Differential correlation analyses uncovered metabolic dysregulation in COVID-19•GM3-enriched exosomes are positively correlated with COVID-19 pathogenesis
Plasma metabolite panel effectively distinguished COVID-19 patients from healthy controls (AUC = 0.975). Plasma monosialodihexosyl gangliosides (GM3s) were negatively correlated with CD4+ T cell count in COVID-19 patients, and GM3-enriched exosomes were positively correlated with disease severity. These observations suggest that GM3-enriched exosomes may participate in pathological processes associated with COVID-19 progression.
Reduction of the uranium(III) metallocene (η5‐C5iPr5)2UI (1) with potassium graphite produces the “second‐generation” uranocene (η5‐C5iPr5)2U (2), which contains uranium in the formal divalent ...oxidation state. The geometry of 2 is that of a perfectly linear bis(cyclopentadienyl) sandwich complex, with the ground‐state valence electron configuration of uranium(II) revealed by electronic spectroscopy and density functional theory to be 5f3 6d1. Appreciable covalent contributions to the metal‐ligand bonds were determined from a computational study of 2, including participation from the uranium 5f and 6d orbitals. Whereas three unpaired electrons in 2 occupy orbitals with essentially pure 5f character, the fourth electron resides in an orbital defined by strong 7s‐6dz2
mixing.
A new generation: Reduction of the uranium(III) metallocene (η5‐C5iPr5)2UI with potassium graphite produces the “second‐generation” uranocene (η5‐C5iPr5)2U, which contains uranium in the formal divalent oxidation state. The geometry of (η5‐C5iPr5)2U is that of a perfectly linear bis(cyclopentadienyl) sandwich complex.
Hepatitis B virus (HBV) infection continues to be a major public health issue worldwide. HBsAg loss is associated with functional remission and improved long‐term outcome, and is considered to be a ...‘functional cure’ (also referred to as clinical or immunologic cure) for chronic hepatitis B. This ideal goal of therapy can be achieved using optimized combination regimens with direct‐acting antivirals eg nucleos(t)ide analogues (NAs) and immunomodulators eg pegylated interferon alpha2a (Peg‐IFN) in selected patients with chronic hepatitis B. Among different combination therapies currently available, those with NA lead‐in followed by Peg‐IFN in virally suppressed patients has been demonstrated to be effective. This review provides an updated overview of the evidence supporting the use of combination therapies and summarizes expert consensus on the roadmap to attain functional cure for chronic hepatitis B patients.
Treatment of severe Coronavirus Disease 2019 (COVID-19) is challenging. We performed a phase 2 trial to assess the efficacy and safety of human umbilical cord-mesenchymal stem cells (UC-MSCs) to ...treat severe COVID-19 patients with lung damage, based on our phase 1 data. In this randomized, double-blind, and placebo-controlled trial, we recruited 101 severe COVID-19 patients with lung damage. They were randomly assigned at a 2:1 ratio to receive either UC-MSCs (4 × 10
cells per infusion) or placebo on day 0, 3, and 6. The primary endpoint was an altered proportion of whole lung lesion volumes from baseline to day 28. Other imaging outcomes, 6-minute walk test (6-MWT), maximum vital capacity, diffusing capacity, and adverse events were recorded and analyzed. In all, 100 COVID-19 patients were finally received either UC-MSCs (n = 65) or placebo (n = 35). UC-MSCs administration exerted numerical improvement in whole lung lesion volume from baseline to day 28 compared with the placebo (the median difference was -13.31%, 95% CI -29.14%, 2.13%, P = 0.080). UC-MSCs significantly reduced the proportions of solid component lesion volume compared with the placebo (median difference: -15.45%; 95% CI -30.82%, -0.39%; P = 0.043). The 6-MWT showed an increased distance in patients treated with UC-MSCs (difference: 27.00 m; 95% CI 0.00, 57.00; P = 0.057). The incidence of adverse events was similar in the two groups. These results suggest that UC-MSCs treatment is a safe and potentially effective therapeutic approach for COVID-19 patients with lung damage. A phase 3 trial is required to evaluate effects on reducing mortality and preventing long-term pulmonary disability. (Funded by The National Key R&D Program of China and others. ClinicalTrials.gov number, NCT04288102.
Background
Mesenchymal stem cell (MSC) infusion was reported to improve liver function in patients with decompensated liver cirrhosis (DLC); however, whether the medication can improve outcome of ...these patients is poorly understood.
Methods
This prospective, open-labeled, randomized controlled study enrolled 219 patients with HBV-related DLC who were divided into control group (
n
= 111) and umbilical cord-derived MSC (UC-MSC)-treated group (
n
= 108), then all of them received a follow-up check from October 2010 to October 2017. The treated patients received three times of UC-MSC infusions at 4-week intervals plus conventional treatment that was only used for control group. The overall survival rate and HCC-free survival rate were calculated as primary endpoints and the liver function and adverse events associated with the medication were also evaluated.
Results
During the follow-up check period from 13 to 75th months, there was a significantly higher overall survival rate in the treated group than the control group, while the difference of the hepatocellular carcinoma event-free survival rate between the treated and control groups was not observed during the 75-month follow-up. UC-MSC treatment markedly improved liver function, as indicated by the levels of serum albumin, prothrombin activity, cholinesterase, and total bilirubin during 48 weeks of follow-up. No significant side effects or treatment-related complications were observed in the UC-MSC group.
Conclusions
Therapy of UC-MSC is not only well tolerated, but also significantly improves long-term survival rate, as well as the liver function in patients with HBV-related DLC. UC-MSC medication, therefore, might present a novel therapeutic approach for the disease.
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