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1.
Front Comput Neurosci ; 18: 1357607, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38585279

RESUMO

This research work introduces a novel, nonintrusive method for the automatic identification of Smith-Magenis syndrome, traditionally studied through genetic markers. The method utilizes cepstral peak prominence and various machine learning techniques, relying on a single metric computed by the research group. The performance of these techniques is evaluated across two case studies, each employing a unique data preprocessing approach. A proprietary data "windowing" technique is also developed to derive a more representative dataset. To address class imbalance in the dataset, the synthetic minority oversampling technique (SMOTE) is applied for data augmentation. The application of these preprocessing techniques has yielded promising results from a limited initial dataset. The study concludes that the k-nearest neighbors and linear discriminant analysis perform best, and that cepstral peak prominence is a promising measure for identifying Smith-Magenis syndrome.

2.
AIDS Behav ; 2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38642211

RESUMO

HIV disproportionately affects Black/African Americans (AA), while PrEP is under-utilized by Black/AA, women, and people who inject drugs (PWID). In San Francisco, California's National HIV Behavioral Surveillance among PWID in 2022, Black/AA women were the least likely to be tested for HIV among all groups by sex and race/ethnicity and the least likely to be aware of PrEP among women. Yet, Black/AA women were no less likely to see a healthcare provider in the last year. Data suggest that providers' failure to discuss and address HIV risk with Black/AA female PWID is a major barrier to accessing effective care and prevention. El VIH afecta de manera desproporcionada a Black/afroamericanos (AA), mientras que la PrEP está infrautilizada por los Black/AA, las mujeres y las personas que se inyectan drogas (PWID). En la National HIV Behavioral Surveillance de PWID de San Francisco, California en 2022, las mujeres Black/AA eran las que menos probabilidades tenían de someterse a la prueba del VIH entre todos los grupos por sexo y raza/etnia y las que menos probabilidades tenían de conocer la PrEP entre las mujeres. Sin embargo, las mujeres Black/AA no tenían menos probabilidades de acudir a un profesional sanitario en el último año. Los datos sugieren que el hecho de que los proveedores no hablen ni aborden el riesgo de VIH con las PWID de raza Black/AA es un obstáculo importante para acceder a una atención y prevención eficaces.

3.
AIDS Behav ; 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38526638

RESUMO

Clinical trials provide evidence that pre-exposure prophylaxis (PrEP) prevents HIV acquisition including through sharing of injection equipment among people who inject drugs (PWID). However, uptake among many populations at risk for HIV has been slow, particularly among PWID. We examined data from the National HIV Behavioral Surveillance (NHBS) from San Francisco in 2022 to measure PrEP uptake and identify factors associated with PrEP awareness among PWID. Of 479 PWID with HIV-negative or unknown HIV status, 54.9% were aware of PrEP, 5.9% had discussed PrEP with a healthcare provider, and 1.5% had used PrEP in the past year. Lack of PrEP awareness was associated with being age 50 years and older (adjusted odds ratio [aOR] 0.40, 95% CI 0.27-0.60), being men who have sex with women (vs. men who have sex with men, aOR 0.47, 95% CI 0.24-0.92), having a disability (aOR 0.58, 95% CI 0.35-0.95), using heroin as their most frequently injected drug (aOR 0.51, 95% CI, 0.34-0.78), not having tested for HIV, HCV, or an STD in the past year (aOR 0.43, 95% CI 0.28-0.64), and not having access to new sterile needles in the past year (aOR 0.28, 95%CI 0.08-1.00). We found negligible change in the awareness and uptake of PrEP among PWID since previously measured in NHBS in 2018. Low PrEP use among PWID may be addressed by increasing provider discussion of PrEP with their PWID patients and clients during routine care, expanding testing for injection-related infections among PWID, and integrating PrEP access into harm reduction programs.

4.
ESC Heart Fail ; 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38454739

RESUMO

AIMS: The current literature provides limited guidance on the best diuretic strategy post-hospitalization for acute heart failure (AHF). It is postulated that the efficacy and safety of the outpatient diuretic regimen may be significantly influenced by the degree of fluid overload (FO) encountered during hospitalization. We hypothesize that in patients with more pronounced FO, reducing their regular oral diuretic dosage might be associated with an elevated risk of unfavourable clinical outcomes. METHODS AND RESULTS: It was a retrospective observational study of 410 patients hospitalized for AHF in which the dose of furosemide at admission and discharge was collected. Patients were categorized across diuretic dose status into two groups: (i) the down-titration group and (ii) the stable/up-titration group. FO status was evaluated by a clinical congestion score and circulating biomarkers. The endpoint of interest was the composite of time to all-cause death and/or heart failure readmission. A multivariable Cox proportional hazard regression model was constructed to analyse the endpoints. The median age was 86 (78-92) years, 256 (62%) were women, and 80% had heart failure with preserved ejection fraction. After multivariate adjustment, the down-titration furosemide equivalent dose remained not associated with the risk of the combined endpoint in the whole sample (hazard ratio 1.34, 95% confidence interval 0.86-2.06, P = 0.184). The risk of the combination of death and/or worsening heart failure associated with the diuretic strategy at discharge was significantly influenced by FO status, including clinical congestion scores and circulating proxies of FO like BNP and cancer antigen 125. CONCLUSIONS: In patients hospitalized for AHF, furosemide down-titration does not imply an increased risk of mortality and/or heart failure readmission. However, FO status modifies the effect of down-titration on the outcome. In patients with severe congestion or residual congestion at discharge, down-titration was associated with an increased risk of mortality and/or heart failure readmission.

5.
Elife ; 122024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38363283

RESUMO

The RNA recognition motif (RRM) is the most common RNA-binding protein domain identified in nature. However, RRM-containing proteins are only prevalent in eukaryotic phyla, in which they play central regulatory roles. Here, we engineered an orthogonal post-transcriptional control system of gene expression in the bacterium Escherichia coli with the mammalian RNA-binding protein Musashi-1, which is a stem cell marker with neurodevelopmental role that contains two canonical RRMs. In the circuit, Musashi-1 is regulated transcriptionally and works as an allosteric translation repressor thanks to a specific interaction with the N-terminal coding region of a messenger RNA and its structural plasticity to respond to fatty acids. We fully characterized the genetic system at the population and single-cell levels showing a significant fold change in reporter expression, and the underlying molecular mechanism by assessing the in vitro binding kinetics and in vivo functionality of a series of RNA mutants. The dynamic response of the system was well recapitulated by a bottom-up mathematical model. Moreover, we applied the post-transcriptional mechanism engineered with Musashi-1 to specifically regulate a gene within an operon, implement combinatorial regulation, and reduce protein expression noise. This work illustrates how RRM-based regulation can be adapted to simple organisms, thereby adding a new regulatory layer in prokaryotes for translation control.


Assuntos
Proteínas do Tecido Nervoso , Proteínas de Ligação a RNA , Animais , Proteínas do Tecido Nervoso/metabolismo , Proteínas de Ligação a RNA/metabolismo , RNA/metabolismo , RNA Mensageiro/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Mamíferos/genética
6.
Cardiorenal Med ; 14(1): 74-80, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38286116

RESUMO

INTRODUCTION: Albuminuria is prevalent in patients with chronic heart failure and is a risk factor for disease progression. However, its clinical meaning in acute heart failure remains elusive. This study analyzed the trajectory of urine albumin to creatinine ratio (UACR) between admission and discharge and its association with decongestion. METHODS: In this prospective observational study, 63 patients were enrolled. UACR, B-type natriuretic peptide (BNP), and clinical congestion score (CCS) were obtained at admission and discharge. We used linear mixed regression analysis to compare changes in the natural logarithm of UACR (logUACR) and its association with changes in markers of decongestion. Estimates were reported as least squares mean with their respective 95% CIs. RESULTS: The median age of the study population was 87 years, 68.5% were women, and 69.8% had a left ventricular ejection fraction >50%. LogUACR at discharge significantly decreased in the overall population compared to admission (Δ -0.47, 95% CI: -0.78 to -0.15, p value = 0.003). The magnitude of UACR drop at discharge was associated with changes in surrogate markers of decongestion. Patients who showed a greater reduction in BNP at discharge exhibited a greater reduction in UACR (p = 0.016). The same trend was also found with clinical decongestion, as assessed by changes in CCS, however, without achieving statistical significance (p = 0.171). UACR change at discharge was not associated with changes in serum creatinine (p value = 0.923). CONCLUSION: In elderly patients with AHF and volume overload, the level of UACR significantly decreased upon discharge compared to admission. This reduction in UACR was closely linked to decreases in BNP.


Assuntos
Albuminúria , Biomarcadores , Creatinina , Insuficiência Cardíaca , Peptídeo Natriurético Encefálico , Humanos , Feminino , Masculino , Creatinina/urina , Creatinina/sangue , Insuficiência Cardíaca/urina , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/fisiopatologia , Estudos Prospectivos , Albuminúria/urina , Idoso de 80 Anos ou mais , Idoso , Doença Aguda , Peptídeo Natriurético Encefálico/sangue , Biomarcadores/urina , Biomarcadores/sangue , Volume Sistólico/fisiologia , Progressão da Doença
7.
Lancet ; 403(10426): 568-582, 2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-38006899

RESUMO

Gene therapy has become a clinical reality as market-approved advanced therapy medicinal products for the treatment of distinct monogenetic diseases and B-cell malignancies. This Therapeutic Review aims to explain how progress in genome editing technologies offers the possibility to expand both therapeutic options and the types of diseases that will become treatable. To frame these impressive advances in the context of modern medicine, we incorporate examples from human clinical trials into our discussion on how genome editing will complement currently available strategies in gene therapy, which still mainly rely on gene addition strategies. Furthermore, safety considerations and ethical implications, including the issue of accessibility, are addressed as these crucial parameters will define the impact that gene therapy in general and genome editing in particular will have on how we treat patients in the near future.


Assuntos
Sistemas CRISPR-Cas , Edição de Genes , Humanos , Terapia Genética
8.
Plant Signal Behav ; 18(1): 2271799, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37879964

RESUMO

Plant metabolism is constantly changing and requires input signals for efficient regulation. The mitochondrial calcium uniporter (MCU) couples organellar and cytoplasmic calcium oscillations leading to oxidative metabolism regulation in a vast array of species. In Arabidopsis thaliana, genetic deletion of AtMICU leads to altered mitochondrial calcium handling and ultrastructure. Here we aimed to further assess the consequences upon genetic deletion of AtMICU. Our results confirm that AtMICU safeguards intracellular calcium transport associated with carbohydrate, amino acid, and phytol metabolism modifications. The implications of such alterations are discussed.


Assuntos
Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Cálcio/metabolismo , Mitocôndrias/metabolismo , Sinalização do Cálcio , Citoplasma/metabolismo
10.
Cell Death Dis ; 14(8): 514, 2023 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-37563155

RESUMO

Progressive hepatic damage and fibrosis are major features of chronic liver diseases of different etiology, yet the underlying molecular mechanisms remain to be fully defined. N-RAS, a member of the RAS family of small guanine nucleotide-binding proteins also encompassing the highly homologous H-RAS and K-RAS isoforms, was previously reported to modulate cell death and renal fibrosis; however, its role in liver damage and fibrogenesis remains unknown. Here, we approached this question by using N-RAS deficient (N-RAS-/-) mice and two experimental models of liver injury and fibrosis, namely carbon tetrachloride (CCl4) intoxication and bile duct ligation (BDL). In wild-type (N-RAS+/+) mice both hepatotoxic procedures augmented N-RAS expression in the liver. Compared to N-RAS+/+ counterparts, N-RAS-/- mice subjected to either CCl4 or BDL showed exacerbated liver injury and fibrosis, which was associated with enhanced hepatic stellate cell (HSC) activation and leukocyte infiltration in the damaged liver. At the molecular level, after CCl4 or BDL, N-RAS-/- livers exhibited augmented expression of necroptotic death markers along with JNK1/2 hyperactivation. In line with this, N-RAS ablation in a human hepatocytic cell line resulted in enhanced activation of JNK and necroptosis mediators in response to cell death stimuli. Of note, loss of hepatic N-RAS expression was characteristic of chronic liver disease patients with fibrosis. Collectively, our study unveils a novel role for N-RAS as a negative controller of the progression of liver injury and fibrogenesis, by critically downregulating signaling pathways leading to hepatocyte necroptosis. Furthermore, it suggests that N-RAS may be of potential clinical value as prognostic biomarker of progressive fibrotic liver damage, or as a novel therapeutic target for the treatment of chronic liver disease.


Assuntos
Cirrose Hepática , Neuroblastoma , Animais , Humanos , Camundongos , Tetracloreto de Carbono/toxicidade , Células Estreladas do Fígado/metabolismo , Fígado/metabolismo , Cirrose Hepática/genética , Cirrose Hepática/tratamento farmacológico , Neuroblastoma/patologia , Oncogenes
11.
Front Immunol ; 14: 1185517, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37457727

RESUMO

Introduction: The Unfolded Protein Response, a mechanism triggered by the cell in response to Endoplasmic reticulum stress, is linked to inflammatory responses. Our aim was to identify novel Unfolded Protein Response-mechanisms that might be involved in triggering or perpetuating the inflammatory response carried out by the Intestinal Epithelial Cells in the context of Inflammatory Bowel Disease. Methods: We analyzed the transcriptional profile of human Intestinal Epithelial Cell lines treated with an Endoplasmic Reticulum stress inducer (thapsigargin) and/or proinflammatory stimuli. Several genes were further analyzed in colonic biopsies from Ulcerative Colitis patients and healthy controls. Lastly, we generated Caco-2 cells lacking HMGCS2 by CRISPR Cas-9 and analyzed the functional implications of its absence in Intestinal Epithelial Cells. Results: Exposure to a TLR ligand after thapsigargin treatment resulted in a powerful synergistic modulation of gene expression, which led us to identify new genes and pathways that could be involved in inflammatory responses linked to the Unfolded Protein Response. Key differentially expressed genes in the array also exhibited transcriptional alterations in colonic biopsies from active Ulcerative Colitis patients, including NKG2D ligands and the enzyme HMGCS2. Moreover, functional studies showed altered metabolic responses and epithelial barrier integrity in HMGCS2 deficient cell lines. Conclusion: We have identified new genes and pathways that are regulated by the Unfolded Protein Response in the context of Inflammatory Bowel Disease including HMGCS2, a gene involved in the metabolism of Short Chain Fatty Acids that may have an important role in intestinal inflammation linked to Endoplasmic Reticulum stress and the resolution of the epithelial damage.


Assuntos
Colite Ulcerativa , Doenças Inflamatórias Intestinais , Humanos , Colite Ulcerativa/patologia , Células CACO-2 , Tapsigargina , Estresse do Retículo Endoplasmático/genética , Doenças Inflamatórias Intestinais/metabolismo , Células Epiteliais/metabolismo , Hidroximetilglutaril-CoA Sintase
12.
Proc Natl Acad Sci U S A ; 120(30): e2303578120, 2023 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-37459528

RESUMO

The evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in humans has been monitored at an unprecedented level due to the public health crisis, yet the stochastic dynamics underlying such a process is dubious. Here, considering the number of acquired mutations as the displacement of the viral particle from the origin, we performed biostatistical analyses from numerous whole genome sequences on the basis of a time-dependent probabilistic mathematical model. We showed that a model with a constant variant-dependent evolution rate and nonlinear mutational variance with time (i.e., anomalous diffusion) explained the SARS-CoV-2 evolutionary motion in humans during the first 120 wk of the pandemic in the United Kingdom. In particular, we found subdiffusion patterns for the Primal, Alpha, and Omicron variants but a weak superdiffusion pattern for the Delta variant. Our findings indicate that non-Brownian evolutionary motions occur in nature, thereby providing insight for viral phylodynamics.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/genética , Difusão , Modelos Estatísticos , Evolução Molecular
13.
Clin Cardiol ; 46(8): 906-913, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37287326

RESUMO

BACKGROUND: Patients with acute heart failure (AHF) require intensification in the diuretic strategy. However, the optimal diuretic strategy remains unclear. In this work, we aimed to evaluate the role of urinary potassium to creatinine ratio (K/Cr) to predict diuretic and natriuretic response to thiazide or mineralocorticoid receptor antagonists (MRAs) in a cohort of patients with AHF and preserved ejection fraction (AHF-pEF). HYPOTHESIS: Patients with a high urinary K/Cr ratio will have a better diuretic and natriuretic response with spironolactone versus chlorthalidone. METHODS: This is a study of 44 patients with AHF-pEF with suboptimal loop diuretic response. The primary endpoint was the baseline K/Cr associated with natriuretic and diuretic effect of chlorthalidone versus spironolactone at 24 and 72 h. Mixed linear regression models were used to analyze the endpoints. Estimates were reported as least squares mean with their respective 95% confidence interval (CIs). RESULTS: The median age of the study population was 85 years (82.5-88.5), and 30 (68.2%) were women. The inferential multivariate analysis suggested a greater natriuretic and diuretic effect of chlorthalidone across K/Cr levels. In the upper category, chlorthalidone translated into a statistically increase in natriuresis at 24 and 72 h. Chlorthalidone versus spironolactone showed ∆uNa of 25.7 mmol/L at 24 h (95% CI = -3.7 to 55.4, p = .098) and ∆uNa of 24.8 mmol/L at 72 h (95% CI = -4 to 53.6, p = .0106). The omnibus p value is .027. Multivariate analyses revealed a significant increase in 72 h cumulative diuresis irrespective of K/Cr status in those on chlorthalidone. CONCLUSIONS: In patients with AHF-pEF and suboptimal diuretic response, diuresis and natriuresis are higher with the administration of chlorthalidone over spironolactone. These data don't support the hypothesis that the K/Cr ratio can help guide the choice of thiazide diuretic versus MRA in AHF-pEF patients on loop diuretic.


Assuntos
Diuréticos , Insuficiência Cardíaca , Humanos , Feminino , Idoso de 80 Anos ou mais , Masculino , Diuréticos/uso terapêutico , Espironolactona/uso terapêutico , Creatinina , Inibidores de Simportadores de Cloreto de Sódio e Potássio/uso terapêutico , Clortalidona/uso terapêutico , Volume Sistólico/fisiologia , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/complicações , Potássio
15.
ESC Heart Fail ; 10(4): 2637-2647, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37349910

RESUMO

AIMS: Previous studies demonstrated the relationship between hypochloraemia and poor prognosis in patients hospitalized for acute heart failure (AHF). However, the usefulness of chloride in clinical practice remains uncertain, notably in very old patients with predominantly heart failure (HF) with preserved ejection fraction (HFpEF). We aimed to evaluate the prognostic impact of chloride in a cohort of very aged patients with AHF and the possible existence of different phenotypes of hypochloraemia with distinct clinical significance. METHODS AND RESULTS: It was an observational study of 429 patients hospitalized for AHF in which chloraemia was measured. Two different phenotypes of hypochloraemia were identified by their relationship with estimated plasma volume status (ePVS) as a proxy of intravascular congestion. The endpoint of interest was time to all-cause mortality and the composite of death and/or HF readmission. A multivariable Cox proportional hazard regression model was constructed to analyse the endpoints. The median age was 85 (78-92) years, 266 (62%) were women, and 80% had HFpEF. After multivariable analysis, chloraemia, but not natraemia, was associated with the risk of death and HF readmission in a U-shaped pattern. The phenotype characterized by hypochloraemia and low ePVS (depletional) was associated with an increased risk of mortality when compared with patients with normochloraemia [hazard ratio (HR) 1.86, P = 0.008]. In contrast, hypochloraemia with high ePVS (dilutional) had no prognostic significance (HR 0.94, P = 0.855). CONCLUSIONS: In very old patients hospitalized with AHF, plasma chloride was associated with the risk of death and HF readmission in a U-shaped pattern and could potentially be used for congestion phenotyping.


Assuntos
Insuficiência Cardíaca , Feminino , Masculino , Humanos , Insuficiência Cardíaca/complicações , Cloretos , Volume Sistólico , Prognóstico , Fenótipo
16.
Anal Chem ; 95(25): 9564-9574, 2023 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-37204239

RESUMO

Recurrent disease outbreaks caused by different viruses, including the novel respiratory virus SARS-CoV-2, are challenging our society at a global scale; so versatile virus detection methods would enable a calculated and faster response. Here, we present a novel nucleic acid detection strategy based on CRISPR-Cas9, whose mode of action relies on strand displacement rather than on collateral catalysis, using the Streptococcus pyogenes Cas9 nuclease. Given a preamplification process, a suitable molecular beacon interacts with the ternary CRISPR complex upon targeting to produce a fluorescent signal. We show that SARS-CoV-2 DNA amplicons generated from patient samples can be detected with CRISPR-Cas9. We also show that CRISPR-Cas9 allows the simultaneous detection of different DNA amplicons with the same nuclease, either to detect different SARS-CoV-2 regions or different respiratory viruses. Furthermore, we demonstrate that engineered DNA logic circuits can process different SARS-CoV-2 signals detected by the CRISPR complexes. Collectively, this CRISPR-Cas9 R-loop usage for the molecular beacon opening (COLUMBO) platform allows a multiplexed detection in a single tube, complements the existing CRISPR-based methods, and displays diagnostic and biocomputing potential.


Assuntos
COVID-19 , Sistemas CRISPR-Cas , Humanos , Sistemas CRISPR-Cas/genética , SARS-CoV-2/genética , COVID-19/diagnóstico , DNA
17.
Microb Biotechnol ; 16(7): 1505-1523, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37097160

RESUMO

Non-coding RNAs (crRNAs) produced from clustered regularly interspaced short palindromic repeats (CRISPR) loci and CRISPR-associated (Cas) proteins of the prokaryotic CRISPR-Cas systems form complexes that interfere with the spread of transmissible genetic elements through Cas-catalysed cleavage of foreign genetic material matching the guide crRNA sequences. The easily programmable targeting of nucleic acids enabled by these ribonucleoproteins has facilitated the implementation of CRISPR-based molecular biology tools for in vivo and in vitro modification of DNA and RNA targets. Despite the diversity of DNA-targeting Cas nucleases so far identified, native and engineered derivatives of the Streptococcus pyogenes SpCas9 are the most widely used for genome engineering, at least in part due to their catalytic robustness and the requirement of an exceptionally short motif (5'-NGG-3' PAM) flanking the target sequence. However, the large size of the SpCas9 variants impairs the delivery of the tool to eukaryotic cells and smaller alternatives are desirable. Here, we identify in a metagenome a new CRISPR-Cas9 system associated with a smaller Cas9 protein (EHCas9) that targets DNA sequences flanked by 5'-NGG-3' PAMs. We develop a simplified EHCas9 tool that specifically cleaves DNA targets and is functional for genome editing applications in prokaryotes and eukaryotic cells.


Assuntos
Sistemas CRISPR-Cas , Metagenoma , Proteína 9 Associada à CRISPR , Edição de Genes , DNA/genética
18.
Phys Chem Chem Phys ; 25(17): 12041-12049, 2023 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-37082985

RESUMO

The design and development of new triplet-triplet annihilation upconversion (TTA-UC) systems combining triplet sensitizers with acceptor compounds have attracted considerable interest. In this vein, sensitizers made from purely organic dyes rather than transition-metal complexes appear to be more convenient from an environmental point of view. BODIPYs are a very well-known class of dyes with applications in a widespread range of scientific areas. Owing to the versatility of BODIPYs, we present herein a new asymmetric BODIPY with excellent photophysical properties to be used as an appropriate sensitizer in a bimolecular TTA-UC system. Detailed spectroscopic measurements demonstrated the ability of this new design to sensitize TTA-UC by combination with a suitable acceptor such as 2,5,8,11-tetra-tert-butylperylene (TBPe), allowing a successful conversion of green to blue light. The singlet-excited TBPe so obtained is capable of activating aryl chlorides reductively which initiated the functionalization of N-methylpyrrole (Meerwein-type arylation) and formation of both substituted triarylethylenes (Mizoroki-Heck reaction) and heteroarene phosphonates (photo-Arbuzov reaction). Product yields reveal that our TTA-UC system behaved as a highly efficient photocatalytic entity.

19.
Photochem Photobiol Sci ; 22(7): 1527-1541, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36922485

RESUMO

A novel dual functional and visual rhodamine ethylenediamine bis(triazolyl silsesquioxane) (RBS) chemosensor was successfully synthesized using "click" chemistry. The results have unambiguously demonstrated that RBS can act in fluorescent and colorimetric sensing of Cu2+ and Zn2+ by their respective coordination with triazole structures and, more importantly, it has also been found that triazole-amide of RBS could turn on chelation-enhanced fluorescence (CHEF) of Cu2+. Remarkably, the addition of Cu2+ triggered an enhanced fluorescent emission by 63.3-fold (ϕF = 0.41), while Zn2+ enhanced it 48.3-fold (ϕF = 0.29) relative to the original RBS (ϕF = 0.006) in acetonitrile (MeCN) solvent. The fluorescent limit of detection for Cu2+ and Zn2+ is similar and fall within 3.0 nM, while under colorimetric sensing the responses were 2.14 × 10-8 and 4.0 × 10-8 mol L-1, respectively. Moreover, the effective sensing profile of RBS and extended applications of RBS-Cu2+ and RBS-Zn2+ for fingerprinting detection and imaging were observed with adequate sensitivity, stability and legibility under the dual visual responses.

20.
Chemistry ; 29(6): e202203353, 2023 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-36314234

RESUMO

A novel visible light promoted formation of CAryl- S bonds through electron donor-acceptor (EDA) complexes of alkylamines with 5- and 6-membered (hetero)arene halides is presented. This represents the first EDA-based thiolation method not relying on π-π or a thiolate-anion-π interactions and provides a facile access to heteroarene radicals, which can be suitably trapped by disulfide derivatives to form the corresponding versatile arylsulfides. Mechanistic investigations on the aspects of the whole process were conducted by spectroscopic measurements, demonstrating the hypothesized EDA complex formation. Moreover, the strength of this method has been proven by a gram-scale synthesis of thiolated products and the late-stage derivatization of an anticoagulant drug.

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