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1.
Chem Sci ; 15(18): 6842-6852, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38725514

RESUMO

End-on binding of dinitrogen to low valent metal centres is common in transition metal chemistry but remains extremely rare in f-elements chemistry. In particular, heterobimetallic end-on N2 bridged complexes of lanthanides are unprecedented despite their potential relevance in catalytic reduction of dinitrogen. Here we report the synthesis and characterization of a series of N2 bridged heterobimetallic complexes of U(iii), Ln(iii) and Ln(ii) which were prepared by reacting the Fe dinitrogen complex [Fe(depe)2(N2)] (depe = 1,2-bis(diethylphosphino)-ethane), complex A with [MIII{N(SiMe3)2}3] (M = U, Ce, Sm, Dy, Tm) and [LnII{N(SiMe3)2}2], (Ln = Sm, Yb). Despite the lack of reactivity of the U(iii), Ln(iii) and Ln(ii) amide complexes with dinitrogen, the end-on dinitrogen bridged heterobimetallic complexes [{Fe(depe)2}(µ-η1:η1-N2)(M{N(SiMe3)2}3)], 1-M (M = U(iii), Ce(iii), Sm(iii), Dy(iii) and Tm(iii)), [{Fe(depe)2}(µ-η1:η1-N2)(Ln{N(SiMe3)2}2)], 1*-Ln (Ln = Sm(ii), Yb(ii)) and [{Fe(depe)2(µ-η1:η1-N2)}2{SmII{N(SiMe3)2}2}], 3 could be prepared. The synthetic method used here allowed to isolate unprecedented end-on bridging N2 complexes of divalent lanthanides which provide relevant structural models for the species involved in the catalytic reduction of dinitrogen by Fe/Sm(ii) systems. Computational studies showed an essentially electrostatic interaction of the end-on bridging N2 with both Ln(iii) and Ln(ii) complexes with the degree of N2 activation correlating with their Lewis acidity. In contrast, a back-bonding covalent contribution to the U(iii)-N2Fe bond was identified by computational studies. Computational studies also suggest that end-on binding of N2 to U(iii) and Ln(ii) complexes is favoured for the iron-bound N2 compared to free N2 due to the higher N2 polarization.

2.
Angew Chem Int Ed Engl ; : e202404264, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38699962

RESUMO

Using single-crystal to single-crystal solid/gas reactivity the gold(I) acetylene complex [Au(L1)(η2-HC≡CH)][BArF4] is cleanly synthesized by addition of acetylene gas to single crystals of [Au(L1)(CO)][BArF4] [L1 = tris-2-(4,4'-di-tert-butylbiphenyl)phosphine, ArF = 3,5-(CF3)2C6H3]. This simplest gold-alkyne complex has been characterized by single crystal X-ray diffraction, solution and solid-state NMR spectroscopy and periodic DFT. Bonding of HC≡CH with [Au(L1)]+ comprises both σ-donation and π-backdonation with additional dispersion interactions within the cavity-shaped phosphine.

3.
Chemistry ; 30(23): e202400049, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38349770

RESUMO

Tetranuclear cores (M-E)2 of transition metals (M) and tetrylenes (EII=Si, Ge, Sn) are key motifs in homogeneous and heterogeneous catalysis. They exhibit a continuum of M-M and E-E bonding within the inorganic core that leads to a variety of structures for which there are no specific synthetic methods. Herein, we report a series of highly reduced [Ni0GeII]2 squares solely stabilized by bulky terphenyl (C6H3-2,6-Ar2) ligands, for which we provide complementary and high-yielding syntheses. Reactivity studies with common Lewis bases (carbene and CO) evince that the structure of the (M-E)2 core can be transformed. We have investigated this core modification by computational means, offering a rationale to better understand the continuum of bonding across these clusters.

4.
Infect Dis Ther ; 13(3): 521-533, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38403865

RESUMO

INTRODUCTION: In the phase 3 TACKLE study, outpatient treatment with AZD7442 (tixagevimab/cilgavimab) was well tolerated and significantly reduced progression to severe disease or death through day 29 in adults with mild-to-moderate coronavirus disease 2019 (COVID-19) at the primary analysis. Here, we report data from the final analysis of the TACKLE study, performed after approximately 15 months' follow-up. METHODS: Eligible participants were randomized 1:1 and dosed within 7 days of symptom onset with 600 mg intramuscular AZD7442 (n = 456; 300 mg tixagevimab/300 mg cilgavimab) or placebo (n = 454). RESULTS: Severe COVID-19 or death through day 29 occurred in 4.4% and 8.8% of participants who received AZD7442 or placebo, a relative risk reduction (RRR) of 50.4% [95% confidence interval (CI) 14.4, 71.3; p = 0.0096]; among participants dosed within 5 days of symptom onset, the RRR was 66.9% (95% CI 31.1, 84.1; p = 0.002). Death from any cause or hospitalization for COVID-19 complications or sequelae through day 169 occurred in 5.0% of participants receiving AZD7442 versus 9.7% receiving placebo, an RRR of 49.2% (95% CI 14.7, 69.8; p = 0.009). Adverse events occurred in 55.5% and 55.9% of participants who received AZD7442 or placebo, respectively, and were mostly mild or moderate in severity. Serious adverse events occurred in 10.2% and 14.4% of participants who received AZD7442 or placebo, respectively, and deaths occurred in 1.8% of participants in both groups. Serum concentration-time profiles recorded over 457 days were similar for AZD7442, tixagevimab, and cilgavimab, and were consistent with the extended half-life reported for AZD7442 (approx. 90 days). CONCLUSIONS: AZD7442 reduced the risk of progression to severe COVID-19, hospitalization, and death, was well tolerated through 15 months, and exhibited predictable pharmacokinetics in outpatients with mild-to-moderate COVID-19. These data support the long-term safety of using long-acting monoclonal antibodies to treat COVID-19. TRIAL REGISTRATION: Clinicaltrials.gov, NCT04723394. ( https://clinicaltrials.gov/study/NCT04723394 .


The body's immune system produces proteins called antibodies that specifically target foreign substances such as viruses. AZD7442 is a combination of two antibodies (called tixagevimab and cilgavimab) that bind to the severe acute respiratory syndrome coronavirus 2 virus spike protein, preventing it from causing coronavirus disease 2019 (COVID-19). AZD7442 was designed to be "long-acting" and therefore provide prolonged protection against COVID-19 lasting several months from a single dose. It was tested in a clinical trial (TACKLE) to see if it could prevent people who had recently developed symptoms of COVID-19 from getting sicker, being hospitalized, or dying. Around 900 adults took part in this clinical trial. Half of this group were treated with a dose of AZD7442, given as two injections. The other half received a placebo (injections that look like the AZD7442 injections but contain no medicine). The effect of AZD7442 treatment against COVID-19 was monitored over 6 months, and safety was monitored over 15 months. Around the same percentage of participants in the trial reported side effects with AZD7442 and placebo, suggesting there were no safety issues with AZD7442. AZD7442 treatment reduced the risk of participants getting severe COVID-19 or dying from COVID-19 by approximately half, compared with the placebo group. Participants receiving AZD7442 also had fewer hospitalizations due to COVID-19 complications, compared with the placebo group. These results showed the long-term safety of using long-acting antibodies such as AZD7442 as a treatment for COVID-19.

5.
J Thromb Haemost ; 22(4): 936-950, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38103737

RESUMO

BACKGROUND: Thrombolytic recombinant tissue plasminogen activator (r-tPA) treatment is the only pharmacologic intervention available in the ischemic stroke acute phase. This treatment is associated with an increased risk of intracerebral hemorrhages, known as hemorrhagic transformations (HTs), which worsen the patient's prognosis. OBJECTIVES: To investigate the association between genetically determined natural hemostatic factors' levels and increased risk of HT after r-tPA treatment. METHODS: Using data from genome-wide association studies on the risk of HT after r-tPA treatment and data on 7 hemostatic factors (factor [F]VII, FVIII, von Willebrand factor [VWF], FXI, fibrinogen, plasminogen activator inhibitor-1, and tissue plasminogen activator), we performed local and global genetic correlation estimation multitrait analyses and colocalization and 2-sample Mendelian randomization analyses between hemostatic factors and HT. RESULTS: Local correlations identified a genomic region on chromosome 16 with shared covariance: fibrinogen-HT, P = 2.45 × 10-11. Multitrait analysis between fibrinogen-HT revealed 3 loci that simultaneously regulate circulating levels of fibrinogen and risk of HT: rs56026866 (PLXND1), P = 8.80 × 10-10; rs1421067 (CHD9), P = 1.81 × 10-14; and rs34780449, near ROBO1 gene, P = 1.64 × 10-8. Multitrait analysis between VWF-HT showed a novel common association regulating VWF and risk of HT after r-tPA at rs10942300 (ZNF366), P = 1.81 × 10-14. Mendelian randomization analysis did not find significant causal associations, although a nominal association was observed for FXI-HT (inverse-variance weighted estimate [SE], 0.07 [-0.29 to 0.00]; odds ratio, 0.87; 95% CI, 0.75-1.00; raw P = .05). CONCLUSION: We identified 4 shared loci between hemostatic factors and HT after r-tPA treatment, suggesting common regulatory mechanisms between fibrinogen and VWF levels and HT. Further research to determine a possible mediating effect of fibrinogen on HT risk is needed.


Assuntos
Hemostáticos , Acidente Vascular Cerebral , Humanos , Ativador de Plasminogênio Tecidual/efeitos adversos , Ativador de Plasminogênio Tecidual/genética , Fator de von Willebrand/análise , Estudo de Associação Genômica Ampla , Proteínas do Tecido Nervoso , Receptores Imunológicos/uso terapêutico , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/genética , Fibrinogênio/análise , Hemostáticos/efeitos adversos , Fatores de Risco
6.
Atherosclerosis ; 386: 117382, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-38006695

RESUMO

BACKGROUND AND AIMS: The lipid profile is consistently associated with coronary artery disease (CAD) and ischemic stroke (IS). However, the lipoprotein subfractions have not been deeply explored in stroke subtypes, especially in IS outcome. METHODS: We performed two-sample Mendelian randomization (MR) analysis using 92 lipid traits measured by nuclear magnetic resonance in 115,000 subjects from the UK Biobank. Data for genetic associations with IS, its subtypes, and long-term outcome (LTO) were obtained from three cohorts of European ancestry: GIGASTROKE (73,652 cases, 1,234,808 controls), GODS (n = 1791) and GISCOME (n = 6165). Results obtained using CARDIoGRAMPlusC4D were used to identify differences with CAD. RESULTS: Genetically determined low concentration of medium high-density lipoprotein (HDL) particles (odds ratio (OR) = 0.92, 95% CI 0.88-0.96; p = 3.6 × 10-4) and its cholesterol content (OR = 0.92, 95% CI 0.88-0.96; p = 1.9 × 10-4) showed causal associations with an increased risk of stroke. Genetic predisposition to high apolipoprotein (apo)B to apoA-I ratio was causally associated with an increased risk of IS (OR = 1.12, 95% CI 1.06-1.18, p = 1.1 × 10-4), and a highly suggestive association was found between non-esterified cholesterol in low-density lipoprotein (LDL) and increased risk of atherothrombotic stroke (LAS) (OR = 1.35, 95% CI 1.10-1.66; p = 4.0 × 10-3). Low cholesterol in small and medium LDL was suggestively associated with poor LTO. CONCLUSIONS: Our results support that low medium HDL concentration was causally associated with an increased stroke risk, while high levels of non-esterified cholesterol in LDL were suggestively associated with an increased risk of LAS and with a better LTO.


Assuntos
Doença da Artéria Coronariana , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Análise da Randomização Mendeliana , Triglicerídeos/genética , LDL-Colesterol/genética , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/genética , Colesterol , Doença da Artéria Coronariana/genética , Estudo de Associação Genômica Ampla , Polimorfismo de Nucleotídeo Único , Fatores de Risco , HDL-Colesterol
7.
Infect Dis Ther ; 12(9): 2269-2287, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37751015

RESUMO

INTRODUCTION: We assessed effects of AZD7442 (tixagevimab/cilgavimab) on deaths from any cause or hospitalizations due to coronavirus disease 2019 (COVID-19) and symptom severity and longer-term safety in the TACKLE adult outpatient treatment study. METHODS: Participants received 600 mg AZD7442 (n = 452) or placebo (n = 451) ≤ 7 days of COVID-19 symptom onset. RESULTS: Death from any cause or hospitalization for COVID-19 complications or sequelae through day 169 (key secondary endpoint) occurred in 20/399 (5.0%) participants receiving AZD7442 versus 40/407 (9.8%) receiving placebo [relative risk reduction (RRR) 49.1%; 95% confidence interval (CI) 14.5, 69.7; p = 0.009] or 50.7% (95% CI 17.5, 70.5; p = 0.006) after excluding participants unblinded before day 169 for consideration of vaccination). AZD7442 reduced progression of COVID-19 symptoms versus placebo through to day 29 (RRR 12.5%; 95% CI 0.5, 23.0) and improved most symptoms within 1-2 weeks. Over median safety follow-up of 170 days, adverse events occurred in 174 (38.5%) and 196 (43.5%) participants receiving AZD7442 or placebo, respectively. Cardiac serious adverse events occurred in two (0.4%) and three (0.7%) participants receiving AZD7442 or placebo, respectively. CONCLUSIONS: AZD7442 was well tolerated and reduced hospitalization and mortality through 6 months, and symptom burden through 29 days, in outpatients with mild-to-moderate COVID-19. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov, NCT04723394. ( https://beta. CLINICALTRIALS: gov/study/NCT04723394 ).


Antibodies are proteins produced by the body's immune system to specifically combat foreign substances, such as viruses. Tixagevimab and cilgavimab are a pair of antibodies that bind to a specific part of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19). When they bind to the virus, they reduce its ability to cause disease. These antibodies were tested in a clinical trial to see if they could prevent people with COVID-19 from being hospitalized or dying. Around 900 adults took part in this clinical trial. These people all had COVID-19 but were not sick enough to be in hospital. Half of this group were treated with a dose of tixagevimab and cilgavimab, given as two injections. The other half received a placebo (injections that look exactly like the tixagevimab and cilgavimab injections but contain no medicine). The study found that, over 6 months, people with COVID-19 who received tixagevimab and cilgavimab were less likely to need to go to hospital than people who received the placebo. They were also less likely to die of COVID-19. Tixagevimab and cilgavimab also helped to improve COVID-19 symptoms. People who received the antibodies saw their symptoms improve faster than people who received the placebo. They were also less likely to have symptoms that got worse. Most people felt better within 1­2 weeks of getting treatment. No safety issues were found with tixagevimab and cilgavimab compared with placebo.

8.
Int J Mol Sci ; 24(17)2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37686257

RESUMO

We aimed to analyse whether patients with ischaemic stroke (IS) occurring within eight days after the onset of COVID-19 (IS-COV) are associated with a specific aetiology of IS. We used SUPERGNOVA to identify genome regions that correlate between the IS-COV cohort (73 IS-COV cases vs. 701 population controls) and different aetiological subtypes. Polygenic risk scores (PRSs) for each subtype were generated and tested in the IS-COV cohort using PRSice-2 and PLINK to find genetic associations. Both analyses used the IS-COV cohort and GWAS from MEGASTROKE (67,162 stroke patients vs. 454,450 population controls), GIGASTROKE (110,182 vs. 1,503,898), and the NINDS Stroke Genetics Network (16,851 vs. 32,473). Three genomic regions were associated (p-value < 0.05) with large artery atherosclerosis (LAA) and cardioembolic stroke (CES). We found four loci targeting the genes PITX2 (rs10033464, IS-COV beta = 0.04, p-value = 2.3 × 10-2, se = 0.02), previously associated with CES, HS6ST1 (rs4662630, IS-COV beta = -0.04, p-value = 1.3 × 10-3, se = 0.01), TMEM132E (rs12941838 IS-COV beta = 0.05, p-value = 3.6 × 10-4, se = 0.01), and RFFL (rs797989 IS-COV beta = 0.03, p-value = 1.0 × 10-2, se = 0.01). A statistically significant PRS was observed for LAA. Our results suggest that IS-COV cases are genetically similar to LAA and CES subtypes. Larger cohorts are needed to assess if the genetic factors in IS-COV cases are shared with the general population or specific to viral infection.


Assuntos
Aterosclerose , Isquemia Encefálica , COVID-19 , AVC Embólico , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/genética , Isquemia Encefálica/complicações , Isquemia Encefálica/genética , COVID-19/complicações , COVID-19/genética , AVC Isquêmico/genética , Artérias
9.
Chemistry ; 29(61): e202301428, 2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37494303

RESUMO

The activation and functionalization of carbon dioxide entails great interest related to its abundance, low toxicity and associated environmental problems. However, the inertness of CO2 has posed a challenge towards its efficient conversion to added-value products. In this review we discuss one of the strategies that have been widely used to capture and activate carbon dioxide, namely the use of donor-acceptor interactions by partnering a Lewis acidic and a Lewis basic fragment. This type of CO2 activation resembles that found in metalloenzymes, whose outstanding performance in catalytically transforming carbon dioxide encourages further bioinspired research. We have divided this review into three general sections based on the nature of the active sites: metal-free examples (mainly formed by frustrated Lewis pairs), main group-transition metal combinations, and transition metal heterobimetallic complexes. Overall, we discuss one hundred compounds that cooperatively activate carbon dioxide by donor-acceptor interactions, revealing a wide range of structural motifs.

10.
Chempluschem ; 88(7): e202300231, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37306244

RESUMO

A cavity-shaped gold(I) complex derived from a bulky tri-(ortho-biaryl)-phosphine ligand shows preferred selectivity towards terminal functionalities in the gold(I)-catalysed hydration of alkynes under mild heating due to a well-defined pocket as catalytic active site. The confinement-induced size-exclusion selectivity investigated for eight alkynes contrasts with other gold(I) complexes bearing bulky phosphine ligands that show reduced selectivity or even similar behaviour towards both internal and terminal alkynes. We also interrogate the potential of gold(III) derivatives for the same catalytic process.


Assuntos
Alcinos , Ouro , Alcinos/química , Ouro/química , Estrutura Molecular , Catálise , Ligantes
11.
Eur J Neurol ; 30(11): 3497-3506, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37329328

RESUMO

BACKGROUND: Gut microbiota plays a role in the pathophysiology of ischaemic stroke (IS) through the bidirectional gut-brain axis. Nevertheless, little is known about sex-specific microbiota signatures in IS occurrence. METHODS: A total of 89 IS patients and 12 healthy controls were enrolled. We studied the taxonomic differences of the gut microbiota between men and women with IS by shotgun metagenomic sequencing. To evaluate the causal effect of several bacteria on IS risk, we performed a two-sample Mendelian randomisation (MR) with inverse-variance weighting (IVW) using genome-wide association analysis (GWAS) summary statistics from two cohorts of 5959 subjects with genetic and microbiota data and 1,296,908 subjects with genetic and IS data, respectively. RESULTS: α-Diversity analysis measured using Observed Species (p = 0.017), Chao1 (p = 0.009) and Abundance-based Coverage Estimator (p = 0.012) indexes revealed that IS men have a higher species richness compared with IS women. Moreover, we found sex-differences in IS patients in relation to the phylum Fusobacteria, class Fusobacteriia, order Fusobacteriales and family Fusobacteriaceae (all Bonferroni-corrected p < 0.001). MR confirmed that increased Fusobacteriaceae levels in the gut are causally associated with an increased risk of IS (IVW p = 0.02, ß = 0.32). CONCLUSIONS: Our study is the first to indicate that there are gut microbiome differences between men and women with IS, identifying high levels of Fusobacteriaceae in women as a specific risk factor for IS. Incorporating sex stratification analysis is important in the design, analysis and interpretation of studies on stroke and the gut microbiota.

12.
Inorg Chem ; 62(27): 10582-10591, 2023 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-37367828

RESUMO

A cavity-shaped linear gold(I) hydroxide complex acts as a platform to access unusual gold monomeric species. Notably, this sterically crowded gold fragment enables the trapping of CO2 via insertion into Au-OH and Au-NH bonds to form unprecedented monomeric gold(I) carbonate and carbamate complexes. In addition, we succeeded in the identification of the first gold(I) terminal hydride bearing a phosphine ligand. The basic nature of the Au(I)-hydroxide moiety is also explored through the reactivity toward other molecules containing acidic protons such as trifluoromethanesulfonic acid and terminal alkynes.

13.
Chem Commun (Camb) ; 59(57): 8826-8829, 2023 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-37358367

RESUMO

We report an iridium system constructed around a long-tethered PGeP ligand that facilitates access to the less common germylene form, so far unreported for an 'NHC-type' Ge ligand. Its bonding is substantiated by computational studies and we have demonstrated its use for the catalytic dehydrogenation of formic acid, highlighting the potential of this underdeveloped type of ligand.


Assuntos
Formiatos , Irídio , Ligantes
14.
N Engl J Med ; 388(20): 1853-1862, 2023 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-37195941

RESUMO

BACKGROUND: Peresolimab is a humanized IgG1 monoclonal antibody designed to stimulate the endogenous programmed cell death protein 1 (PD-1) inhibitory pathway. Stimulation of this pathway would be a novel approach to the treatment of patients with autoimmune or autoinflammatory diseases. METHODS: In this phase 2a, double-blind, randomized, placebo-controlled trial, we assigned, in a 2:1:1 ratio, adult patients with moderate-to-severe rheumatoid arthritis who had had an inadequate response to, a loss of response to, or unacceptable side effects with conventional synthetic disease-modifying antirheumatic drugs (DMARDs) or to biologic or targeted synthetic DMARDs to receive 700 mg of peresolimab, 300 mg of peresolimab, or placebo intravenously once every 4 weeks. The primary outcome was the change from baseline to week 12 in the Disease Activity Score for 28 joints based on the C-reactive protein level (DAS28-CRP). The DAS28-CRP ranges from 0 to 9.4, with higher scores indicating more severe disease. The primary comparison was between the 700-mg group and the placebo group. Secondary outcomes included the percentages of patients with American College of Rheumatology 20 (ACR20), ACR50, and ACR70 responses - defined as improvements from baseline of 20%, 50%, and 70% or more, respectively, in the numbers of tender and swollen joints and in at least three of five important domains - at week 12. RESULTS: At week 12, the change from baseline in the DAS28-CRP was significantly greater in the 700-mg peresolimab group than in the placebo group (least-squares mean change [±SE], -2.09±0.18 vs. -0.99±0.26; difference in change, -1.09 [95% confidence interval, -1.73 to -0.46]; P<0.001). The results of the analyses of secondary outcomes favored the 700-mg dose over placebo with respect to the ACR20 response but not with respect to the ACR50 and ACR70 responses. Adverse events were similar in the peresolimab and placebo groups. CONCLUSIONS: Peresolimab showed efficacy in a phase 2a trial in patients with rheumatoid arthritis. These results provide evidence that stimulation of the PD-1 receptor has potential efficacy in the treatment of rheumatoid arthritis. (Funded by Eli Lilly; ClinicalTrials.gov number, NCT04634253.).


Assuntos
Anticorpos Monoclonais Humanizados , Antirreumáticos , Artrite Reumatoide , Adulto , Humanos , Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/uso terapêutico , Antirreumáticos/administração & dosagem , Antirreumáticos/efeitos adversos , Antirreumáticos/uso terapêutico , Artrite Reumatoide/diagnóstico , Artrite Reumatoide/tratamento farmacológico , Método Duplo-Cego , Quimioterapia Combinada , Índice de Gravidade de Doença , Resultado do Tratamento , Imunoglobulina G , Administração Intravenosa , Receptor de Morte Celular Programada 1/agonistas
15.
Inorg Chem ; 62(15): 5961-5971, 2023 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-37010818

RESUMO

The divergent reactivity of the cationic iridium complex [(η5-C5Me5)IrCl(PMe2ArDipp2)]+ (ArDipp2 = C6H3-2,6-(C6H3-2,6-iPr2)2) toward organolithium and Grignard reagents is described. The noninnocent behavior of the Cp* ligand, a robust spectator in the majority of stoichiometric and catalytic reactions, was manifested by its unforeseen electrophilic character toward organolithium reagents LiMe, LiEt, and LinBu. In these unconventional transformations, the metal center is only indirectly involved by means of the Ir(III)/Ir(I) redox cycle. In the presence of less nucleophilic organolithium reagents, the Cp* ligand also exhibits noninnocent behavior undergoing facile deprotonation, which is also concomitant with the reduction of the metal center. In turn, the weaker alkylating agents EtMgBr and MeMgBr effectively achieve the alkylation of the metal center. These reactive iridium(III) alkyls partake in subsequent reactions: while the ethyl complex undergoes ß-H elimination, the methyl derivative releases methane by a remote C-H bond activation. Computational studies, including the quantum theory of atoms in molecules (QTAIM), support that the preferential activation of the non-benzylic C-H bonds takes place via sigma-bond metathesis.

16.
Dalton Trans ; 52(12): 3835-3845, 2023 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-36866716

RESUMO

The combination of molecular metallic fragments of contrasting Lewis character offers many possibilities for cooperative bond activation and for the disclosure of unusual reactivity. Here we provide a systematic investigation on the partnership of Lewis basic Rh(I) compounds of type [(η5-L)Rh(PR3)2] (η5-L = (C5Me5)- or (C9H7)-) with highly congested Lewis acidic Au(I) species. For the cyclopentadienyl Rh(I) compounds, we demonstrate the non-innocent role of the typically robust (C5Me5)- ligand through migration of a hydride to the Rh site and provide evidence for the direct implication of the gold fragment in this unusual bimetallic ligand activation event. This process competes with the formation of dinuclear Lewis adducts defined by a dative Rh → Au bond, with selectivity being under kinetic control and tunable by modifying the stereoelectronic and chelating properties of the phosphine ligands bound to the two metals. We provide a thorough computational study on the unusual Cp* non-innocent behavior and the divergent bimetallic pathways observed. The cooperative FLP-type reactivity of all bimetallic pairs has been investigated and computationally examined for the case of N-H bond activation in ammonia.

17.
Signal Transduct Target Ther ; 8(1): 46, 2023 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-36717539

RESUMO

Meplazumab, a humanized CD147 antibody, has shown favourable safety and efficacy in our previous clinical studies. In DEFLECT (NCT04586153), 167 patients with severe COVID-19 were enroled and randomized to receive three dosages of meplazumab and a placebo. Meplazumab at 0.12 mg/kg, compared to the placebo group, showed clinical benefits in significantly reducing mortality by 83.6% (2.4% vs. 14.6%, p = 0.0150), increasing the proportion of patients alive and discharged without supplemental oxygen (82.9% vs. 70.7%, p = 0.0337) and increasing the proportion of patients who achieved sustained clinical improvement (41.5% vs. 31.7%). The response rate in the 0.2 mg/kg group was relatively increased by 16.0% compared with the placebo group (53.7% vs. 46.3%). Meplazumab also reduced the viral loads and multiple cytokine levels. Compare with the placebo group, the 0.3 mg/kg significantly increased the virus negative rate by 40.6% (p = 0.0363) and reduced IL-8 level (p = 0.0460); the 0.2 mg/kg increased the negative conversion rate by 36.9%, and reduced IL-4 (p = 0.0365) and IL-8 levels (p = 0.0484). In this study, the adverse events occurred at a comparable rate across the four groups, with no unexpected safety findings observed. In conclusion, meplazumab promoted COVID-19 convalescence and reduced mortality, viral load, and cytokine levels in severe COVID-19 population with good safety profile.


Assuntos
COVID-19 , Humanos , Adulto , SARS-CoV-2 , Interleucina-8 , Citocinas
18.
ACS Macro Lett ; 12(1): 33-39, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36541858

RESUMO

Surface-aligned liquid-crystal networks (LCNs) offer a solution for developing functional materials capable of performing a range of tasks, including actuation, shape memory, and surfaces patterning. Here we show that Diels-Alder cycloaddition can be used to prepare the backbone of planar aligned LCNs under mild ambient conditions without the addition of additives or UV irradiation. The mechanical properties of the networks have robust viscoelastic modulus and stiffness with a reversible local free volume change upon physical aging. This study shows new opportunities to design surface-aligned LCNs based on additive free step-growth Diels-Alder polymerization and enables the potential to incorporate a wider range of photochromic materials into LCNs.


Assuntos
Cristais Líquidos , Reação de Cicloadição
19.
Angew Chem Int Ed Engl ; 62(1): e202214339, 2023 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-36315038

RESUMO

Aligned liquid crystal polymers are materials of interest for electronic, optic, biological and soft robotic applications. The manufacturing and processing of these materials have been widely explored with mechanical alignment establishing itself as a preferred method due to its ease of use and widespread applicability. However, the fundamental chemistry behind the required two-step polymerization for mechanical alignment has limitations in both fabrication and substrate compatibility. In this work we introduce a new protection-deprotection approach utilizing a two-stage Diels-Alder cyclopentadiene-maleimide step-growth polymerization to enable mild yet efficient, fast, controlled, reproducible and user-friendly polymerizations, broadening the scope of liquid crystal systems. Thorough characterization of the films by DSC, DMA, POM and WAXD show the successful synthesis of a uniaxially aligned liquid crystal network with thermomechanical actuation abilities.

20.
Clin Infect Dis ; 76(3): e10-e17, 2023 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-36065065

RESUMO

BACKGROUND: Despite vaccination, many remain vulnerable to coronavirus disease 2019 (COVID-19) and its complications. Oral antivirals to prevent COVID-19 progression are vital. Based on perceived potency and clinical efficacy, favipiravir is widely used to treat COVID-19. Evidence from large randomized controlled trials (RCT) is lacking. METHODS: In this multicenter double-blinded placebo-controlled RCT, adults with early mild-to-moderate COVID-19 were 1:1 randomized to favipiravir or placebo. The study evaluated time to sustained clinical recovery (TT-SCR), COVID-19 progression, and cessation of viral shedding. RESULTS: Of 1187 analyzed patients across 40 centers, 83.3% were Hispanic, 89.0% unvaccinated, 70.3% severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seronegative, and 77.8% had risk factors for COVID-19 progression. The median time from symptom presentation and from positive test to randomization was 3 and 2 days, respectively. There was no difference in TT-SCR (median of 7 days for both groups; P = .80), COVID-19 progression [11 patients each (1.9% vs 1.8%); P = .96], time to undetectable virus (median = 6 days, 95% confidence interval [CI] [6-8] vs 7 days, 95% CI [6-9]), or in undetectable virus by end of therapy (73.4% vs 72.3%; P = .94). Outcomes were consistent across the analyzed sub-groups. Adverse events were observed in 13.8% and 14.8% of favipiravir-treated and placebo-treated subjects, respectively. Uric acid elevation was more frequent among favipiravir-treated subjects (19.9% vs 2.8%). CONCLUSIONS: Favipiravir was well tolerated but lacked efficacy in TT-SCR, progression to severe COVID-19, or cessation of viral shedding and should not be used to treat patients with COVID-19. (Supported by Appili Therapeutics). CLINICAL TRIALS REGISTRATION: NCT04600895.


Assuntos
COVID-19 , Adulto , Humanos , SARS-CoV-2 , Amidas/uso terapêutico , Pirazinas/uso terapêutico , Antivirais , Resultado do Tratamento , Ensaios Clínicos Controlados Aleatórios como Assunto
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