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1.
J Virol ; 97(2): e0187122, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36648234

RESUMO

Pseudorabies virus (PRV) is a neurotropic virus causing obvious neurological disorders and reproductive failure in pigs. PRV entry into target cells is a complex multistep process initiated by interacting viral envelope glycoproteins with cellular receptors. In the current study, we found that thrombospondin 3 (THBS3) plays an important role in PRV entry into target cells, indicating that THBS3 is a new PRV coreceptor. To confirm this hypothesis, the knockdown of THBS3 in several permissive cells inhibited PRV primary infection, and overexpression of THBS3 in PK15 cells promoted PRV infection. CRISPR-Cas9 knockout markedly reduced PRV infection in PK15 cells. Antibodies against THBS3 blocked PRV infection in naturally permissive target cells. Moreover, soluble THBS3 protein neutralized the infectivity of PRV. Mechanistically, THBS3 interacted with the PRV gD via its N and C termini to facilitate PRV binding in permissive and nonpermissive cells. Also, in the absence of Nectin-1, THBS3 promoted cell-to-cell fusion mediated by virus glycoproteins. While THBS3 alone could not increase virus entry, overexpression of it in the presence of Nectin-1 promoted virus entry into CHO-K1 cells. Our results have identified THBS3 as a critical player in PRV binding and subsequent membrane fusion and entry. IMPORTANCE Herpesvirus entry occurs through a cascade of virus-cell interactions, and multiple surface glycoproteins play a role in virus binding and entry during the virus invasion process. Early studies showed that attachment to cells by PRV, as well as other alphaherpesviruses, is mediated by interactions between the viral glycoprotein gC and cell membrane proteoglycans carrying heparan sulfate chains (HSPGs). However, gD may also be involved in virus binding in an HSPG-independent manner. To date, the respective cellular receptors are still unknown. In this report, we identified a host molecule, THBS3, involved in gD-mediated PRV binding and subsequent membrane fusion and entry, which increases our understanding of the initial events in alpha herpesvirus infections.


Assuntos
Herpesvirus Suídeo 1 , Pseudorraiva , Ligação Viral , Internalização do Vírus , Animais , Cricetinae , Células CHO , Herpesvirus Suídeo 1/metabolismo , Herpesvirus Suídeo 1/patogenicidade , Nectinas/genética , Nectinas/metabolismo , Suínos , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo , Técnicas de Silenciamento de Genes
2.
Chem Rev ; 122(18): 14554-14593, 2022 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-35960873

RESUMO

The past decade has witnessed remarkable success in the synthesis of curved polycyclic aromatics through Scholl reactions which enable oxidative aryl-aryl coupling even in company with the introduction of significant steric strain. These curved polycyclic aromatics are not only unique objects of structural organic chemistry in relation to the nature of aromaticity but also play an important role in bottom-up approaches to precise synthesis of nanocarbons of unique topology. Moreover, they have received considerable attention in the fields of supramolecular chemistry and organic functional materials because of their interesting properties and promising applications. Despite the great success of Scholl reactions in synthesis of curved polycyclic aromatics, the outcome of a newly designed substrate in the Scholl reaction still cannot be predicted in a generic and precise manner largely due to limited understanding on the reaction mechanism and possible rearrangement processes. This review provides an overview of Scholl reactions with a focus on their applications in synthesis of curved polycyclic aromatics with interesting structures and properties and aims to shed light on the key factors that affect Scholl reactions in synthesizing sterically strained polycyclic aromatics.

3.
BMC Pulm Med ; 24(1): 96, 2024 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-38402169

RESUMO

BACKGROUND: Advanced lung adenocarcinoma patients often develop resistance to EGFR tyrosine kinase inhibitors (EGFR-TKIs), leaving uncertainties regarding subsequent treatment strategies. Although personalized therapy targeting individual acquired resistances (ARs) shows promise, its efficacy has not been systematically compared with platinum-containing doublet chemotherapy, a widely accepted treatment after EGFR-TKIs failure. METHODS: A retrospective dual-center study was conducted involving patients with advanced lung adenocarcinoma and EGFR mutations who developed resistance to EGFR-TKIs between January 2017 and December 2022. Eligible patients were adults aged 18 years or older with an Eastern Cooperative Oncology Group score of 0-1, normal organ function, and no prior chemotherapy. Patients were divided into the chemotherapy group (CG) or personalized therapy group (PG) based on the treatment received after disease progression. The primary endpoints were progression-free survival (PFS) and objective response rate (ORR). RESULTS: Of the 144 patients enrolled, there were 53 patients in the PG and 91 patients in the CG. The PG acquired resistance to EGFR-TKIs through the MET amplification (27, 50%) and small cell lung cancer transformation (16, 30%) and 18% of them reported multiple resistance mechanisms. The ORR of the PG was similar to that of the CG (34% vs. 33%, P = 1.0) and the PFS of the PG patients was not statistically different from that of their CG counterparts [4.2 months (95% CI: 3.6-4.8 months) vs. 5.3 months (95% CI: 4.6-6.0 months), P = 0.77]. CONCLUSIONS: These findings suggest that the therapeutic efficacy of chemotherapy approximates to that of personalized therapy, which signifies that chemotherapy is still a reliable choice for patients who develop resistance to EGFR-TKIs and that further research is awaited to explore the benefit of personalized treatment.


Assuntos
Adenocarcinoma de Pulmão , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Adulto , Humanos , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Estudos Retrospectivos , Inibidores de Proteínas Quinases/efeitos adversos , Receptores ErbB/genética , Adenocarcinoma de Pulmão/tratamento farmacológico , Adenocarcinoma de Pulmão/genética , Mutação
4.
Int J Mol Sci ; 25(4)2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38396637

RESUMO

A citric acid cross-linked ß-cyclodextrin (ß-CD) polymer was synthesized and loaded on micro-ceramic balls to fabricate the solid-phase adsorbents (P-MCB) for adsorption and extraction of triazole pesticides from water. The stability of ß-CD polymer and P-MCB was investigated in solutions with different pH values at different temperatures. The adsorption properties and the influence of kinetics, sorbent amount, pesticide concentration, and temperature on the adsorption capacity were evaluated. The results showed P-MCB had favorable adsorption of 15.98 mg/g flutriafol in 3.5 h. The equilibrium data followed the Freundlich equation, and the adsorption of flutriafol and diniconazole followed the second-order kinetics. The recovery rate of P-MCB for triazole pesticides in water was satisfactory, and the recovery rate was still 80.1%, even at the 10th cycle. The P-MCB had good stability, with a degradation rate of 0.2% ± 0.08 within 10 days, which could ensure extraction and recycling.


Assuntos
Celulose , Ciclodextrinas , Praguicidas , Poluentes Químicos da Água , Praguicidas/química , Água/química , Polímeros/química , Extração em Fase Sólida , Triazóis , Adsorção , Poluentes Químicos da Água/química
5.
Angew Chem Int Ed Engl ; 63(23): e202402756, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38563770

RESUMO

This article presents trioxa[9]circulene (3) as a novel member of hetero[n]circulenes. Its synthesis began with the synthesis of dimethoxydioxa[8]helicene (5) and used dimethoxydiepoxycyclononatrinaphthalene (4) as a key intermediate, despite the condensation reaction predominantly yielding a 1,4-addition byproduct. The structures and properties of 3-5 were extensively investigated using experimental and computational methods. Analysis of the crystal structures reveal elongation of the internal C-C bonds in the nine-membered ring of 3 compared to 4 and 5. Computational studies demonstrate the remarkable flexibility of trioxa[9]circulene's saddle-shaped polycyclic framework, while the other two compounds are rigid with large racemization barriers. Optically pure forms of 4 and 5 exhibit absorption and luminescence dissymmetry factors on the order of 10-2, with smaller values observed for compound 4. In the crystal structures, molecules of 3 stack to form columns with remarkable π-π overlap, and the π-π interactions of 4 exhibit short intermolecular C-to-C contacts. Consequently, the solution-processed film of 4 functioned as a p-type organic semiconductor in field effect transistors.

6.
Chemistry ; 29(32): e202203693, 2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-36918515

RESUMO

New molecular scaffolds of C-, Z- and box-shaped configurations are constructed by fusing phenazine and pyrene units with oxanorbornene. As revealed by X-ray crystallography, the C-shaped molecules exhibit two interesting π-π stacking modes of phenazine depending on the substituting groups, and the box-shaped molecule accommodates two chloroform molecules in the cavity and forms H-bonds with another four molecules of chloroform. The C- and Z-shaped molecules as a pair of diastereomers exhibit almost the same charge transfer absorption and emission including positive solvatochromism, indicating that the intramolecular charge transfer between pyrene (π-donor) and phenazine (π-acceptor) is not dependent on the overall molecular geometry.


Assuntos
Clorofórmio , Pirenos , Modelos Moleculares , Fenazinas
7.
BMC Cancer ; 23(1): 1244, 2023 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-38104105

RESUMO

AIMS: To investigate the predictive value of baseline C-reactive protein (CRP) levels on the efficacy of chemotherapy plus immune checkpoint inhibitors (ICI) in patients with advanced lung squamous cell carcinoma (LSCC). MATERIALS AND METHODS: In this retrospective multicenter study spanning from January 2016 to December 2020, advanced LSCC patients initially treated with chemotherapy or a combination of chemotherapy and ICI were categorized into normal and elevated CRP subgroups. The relationship between CRP levels and treatment outcomes was analyzed using multivariate Cox proportional hazards models and multivariate logistic regression, focusing primarily on the progression-free survival (PFS) endpoint, and secondarily on overall survival (OS) and objective response rate (ORR) endpoints. Survival curves were generated using the Kaplan-Meier method, with the log-rank test used for comparison between groups. RESULTS: Of the 245 patients evaluated, the 105 who received a combination of chemotherapy and ICI with elevated baseline CRP levels exhibited a significant reduction in PFS (median 6.5 months vs. 11.8 months, HR, 1.78; 95% CI: 1.12-2.81; p = 0.013) compared to those with normal CRP levels. Elevated CRP was identified as an independent risk factor for poor PFS through multivariate-adjusted analysis. However, among the 140 patients receiving chemotherapy alone, baseline CRP levels did not significantly influence PFS. Furthermore, within the combination therapy group, there was a notable decrease in the ORR (51% vs. 71%, p = 0.035), coupled with a significantly shorter OS (median 20.9 months vs. 31.5 months, HR, 2.24; 95% CI: 1.13-4.44; p = 0.033). CONCLUSION: In patients with advanced LSCC, elevated baseline CRP levels were identified as an independent predictive factor for the efficacy of combination therapy with chemotherapy and ICI, but not in chemotherapy alone. This suggests that CRP may be a valuable biomarker for guiding treatment strategies.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Carcinoma de Células Escamosas , Neoplasias Pulmonares , Humanos , Proteína C-Reativa , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Estudos Retrospectivos , Carcinoma de Células Escamosas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Pulmão
8.
J Neurooncol ; 165(3): 517-525, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38104049

RESUMO

PURPOSE: Cerebrospinal fluid (CSF) has revealed the unique genetic characteristics of leptomeningeal metastasis (LM) from non-small cell lung cancer (NSCLC). However, the research in this area is still very limited. METHODS: Patients with LM from NSCLC (n = 80) were retrospectively analyzed. Circulating tumor DNA (ctDNA) in CSF was tested by next-generation sequencing (NGS), with paired extracranial tissue or plasma samples included for comparison. An independent non-LM cohort (n = 100) was also analyzed for comparative purposes. Clinical outcomes were compared with Kaplan-Meier log-rank test and Cox proportional hazards methodologies. RESULTS: An overwhelming 93.8% of patients carried druggable mutations in NSCLC LM, with EGFR (78.8%) being the most prevalent. Notably, 4 patients who tested negative for driver genes in extracranial samples surprisingly showed EGFR mutations in their CSF and subsequently benefited from targeted therapy. There was a clear difference in genetic profiles between CSF and extracranial samples, with CSF showing more driver gene detections, increased Copy Number Variations (CNVs), and varied resistance mechanisms among individuals. Abnormalities in cell-cycle regulatory molecules were highly enriched in LM (50.9% vs 31.0%, p = 0.017), and CDKN2A/2B deletions were identified as an independent poor prognostic factor for LM patients, with a significant reduction in median OS (p = 0.013), supported by multivariate analysis (HR 2.63, 95% CI 1.32-5.26, p = 0.006). CONCLUSIONS: CSF-based ctDNA analysis is crucial for detecting and characterizing genetic alterations in NSCLC LM. The distinct genetic profiles in CSF and extracranial tissues emphasize the need for personalized treatment approaches.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , DNA Tumoral Circulante , Neoplasias Pulmonares , Carcinomatose Meníngea , Humanos , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/patologia , DNA Tumoral Circulante/genética , Variações do Número de Cópias de DNA , Estudos Retrospectivos , Prognóstico , Carcinomatose Meníngea/genética , Carcinomatose Meníngea/patologia , Mutação , Receptores ErbB/genética
9.
J Neurooncol ; 165(2): 301-312, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37995007

RESUMO

PURPOSE: To explore the impact of intrathecal pemetrexed (IP) on the survival of lung adenocarcinoma (LUAC) patients with leptomeningeal metastasis (LM). METHODS: We analyzed patients with LUAC and LM who received systemic therapy after LM diagnosis at the Fujian Cancer Hospital between July 2018 and March 2022. Patients who underwent IP were assigned to the IP group; those without IP treatment were designated as the non-IP group. Propensity score matching (PSM) was performed between the two groups. RESULTS: 165 patients were enrolled: 83 and 82 in the IP and non-IP groups, respectively. After 1:1 PSM, we included 114 patients in the matched cohort. Median overall survival (OS) was 13.2 months (95% CI 10.8-15.6 months) in the IP group versus 10.1 months (95% CI 5.3-14.9 months) in the non-IP group (P = 0.488). Only Eastern Cooperative Oncology Group Performance Status (ECOG PS) was confirmed as an independent predictor for OS in the matched cohort (hazard ratio (HR) 2.03; P = 0.023). Multivariate competing-risks analysis showed that IP significantly correlated with central nervous system-related death (HR 0.31; P = 0.046). When stratified by ECOG PS, IP improved survival in patients with poor ECOG PS (PS = 2) (14.3 months vs. 1.6 months; P = 0.003). CONCLUSIONS: Intrathecal pemetrexed did not enhance OS for the entire LUAC patient with LM compared to non-intrathecal chemotherapy. However, it exhibited the potential to reduce the risk of central nervous system-related mortality and improve survival in patients with poor ECOG PS.


Assuntos
Adenocarcinoma de Pulmão , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinomatose Meníngea , Humanos , Pemetrexede/uso terapêutico , Neoplasias Pulmonares/patologia , Pontuação de Propensão , Adenocarcinoma de Pulmão/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinomatose Meníngea/tratamento farmacológico , Carcinomatose Meníngea/etiologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico
10.
J Am Chem Soc ; 144(36): 16612-16619, 2022 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-36043840

RESUMO

Herein, we report robust π-conjugated radical cations resulting from the oxidation of hexabenzoperylene (HBP) derivatives, HBP-B and HBP-H, which have butyl and hexyl groups, respectively, attached to the same twisted double helicene π-backbone. The radical cation of HBP-B was successfully crystallized in the form of hexafluorophosphate, which exhibited conductivity as high as 1.32 ± 0.04 S cm-1. Photochemical oxidation of HBP-H by molecular oxygen led to the formation of its radical cation in the solid state, as found with different techniques. This allowed the organic field effect transistor of HBP-H to function as a nonvolatile optoelectronic memory, with the memory switching contrast above 103 and long-term stability without using a floating gate, an electret layer, or photochromic molecules.

11.
J Virol ; 95(13): e0033621, 2021 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-33853967

RESUMO

To replicate efficiently and evade the antiviral immune response of the host, some viruses degrade host mRNA to induce host gene shutoff via encoding shutoff factors. In this study, we found that feline calicivirus (FCV) infection promotes the degradation of endogenous and exogenous mRNAs and induces host gene shutoff, which results in global inhibition of host protein synthesis. Screening assays revealed that proteinase-polymerase (PP) is a most effective factor in reducing mRNA expression. Moreover, PP from differently virulent strains of FCV could induce mRNA degradation. Further, we found that the key sites of the PP protein required for its proteinase activity are also essential for its shutoff activity but also required for viral replication. The mechanism analysis showed that PP mainly targets Pol II-transcribed RNA in a ribosome-, 5' cap-, and 3' poly(A) tail-independent manner. Moreover, purified glutathione S-transferase (GST)-PP fusion protein exhibits RNase activity in vitro in assays using green fluorescent protein (GFP) RNA transcribed in vitro as a substrate in the absence of other viral or cellular proteins. Finally, PP-induced shutoff requires host Xrn1 to complete further RNA degradation. This study provides a newly discovered strategy in which FCV PP protein induces host gene shutoff by promoting the degradation of host mRNAs. IMPORTANCE Virus infection-induced shutoff is the result of targeted or global manipulation of cellular gene expression and leads to efficient viral replication and immune evasion. FCV is a highly contagious pathogen that persistently infects cats. It is unknown how FCV blocks the host immune response and persistently exists in cats. In this study, we found that FCV infection promotes the degradation of host mRNAs and induces host gene shutoff via a common strategy. Further, PP protein for different FCV strains is a key factor that enhances mRNA degradation. An in vitro assay showed that the GST-PP fusion protein possesses RNase activity in the absence of other viral or cellular proteins. This study demonstrates that FCV induces host gene shutoff by promoting the degradation of host mRNAs, thereby introducing a potential mechanism by which FCV infection inhibits the immune response.


Assuntos
Calicivirus Felino/crescimento & desenvolvimento , Evasão da Resposta Imune/imunologia , Peptídeo Hidrolases/metabolismo , Estabilidade de RNA/fisiologia , RNA Mensageiro/metabolismo , Ribonucleases/metabolismo , Animais , Infecções por Caliciviridae/patologia , Calicivirus Felino/genética , Calicivirus Felino/metabolismo , Gatos , Linhagem Celular , Células HEK293 , Humanos , Evasão da Resposta Imune/genética , Peptídeo Hidrolases/genética , Biossíntese de Proteínas/fisiologia , Interferência de RNA , RNA Interferente Pequeno/genética , Ribonucleases/genética , Replicação Viral
12.
Cerebrovasc Dis ; 51(2): 225-234, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34644707

RESUMO

INTRODUCTION: It is not clear whether serum uric acid (SUA) levels and their changes over time are associated with the risk of stroke. A 7-year prospective cohort study in northwest China was conducted to analyze effects of SUA and their changes on the risk of stroke. METHODS: A total of 23,262 individuals without cardiovascular disease in the Jinchang cohort were followed up for an average of 5.26 years. The Cox proportional hazard model was used to estimate the hazard ratios (HRs) and 95% confidence interval (95% CI) of stroke incidence to SUA and relative changes in SUA. Sensitivity analysis was performed after controlling the effect of renal insufficiency. RESULTS: Baseline SUA and relative changes in SUA were positively correlated with the incidence of stroke in both males and females (p for overall association <0.0001). Stroke risk increased by 4.6% per 10% increase in the relative change of SUA (HR = 1.046, 95% CI, 1.007-1.086). The fully adjusted regression analysis demonstrated that only the large gain (>30%) in SUA was associated with an increased risk of stroke by 36.5% (95% CI, 1.8-83.0%), compared with the reference group (participants within ±10% changes in SUA). The same trend was observed in people with normal baseline SUA. In the unadjusted model, the risk of stroke associated with elevated SUA was significantly higher in the hyperuricemia group than in the normal SUA group. CONCLUSION: High initial SUA concentration and an increase in SUA concentration over time would increase the risk of stroke, and this means that there is no safe increase in SUA.


Assuntos
Hiperuricemia , Acidente Vascular Cerebral , China/epidemiologia , Estudos de Coortes , Feminino , Humanos , Hiperuricemia/diagnóstico , Hiperuricemia/epidemiologia , Masculino , Estudos Prospectivos , Fatores de Risco , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/epidemiologia , Ácido Úrico
13.
Inorg Chem ; 61(1): 738-745, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34914388

RESUMO

Developing earth-abundant electrocatalysts for efficient oxygen evolution reaction (OER) is of paramount significance for electrochemical water splitting. Herein, an efficient in situ etching-deposition growth strategy is employed to transform pristine two-dimensional (2D) Co-metal-organic frameworks into hollow Ni/Co double hydroxide arrays (denoted as Ni/Co-DH), which not only yields a larger surface area and exposes more active sites but also decreases the activation energy to the OER. With structural and compositional benefits, the Ni/Co-DH exhibits high performance with an overpotential of 229 mV at 10 mA cm-2 and exceptional long-term stability of over 90 h in 1 M KOH medium for OER, comparable to most non-noble oxygen evolution catalysts reported so far. In addition, a two-electrode Ni/Co-DH∥Pt/C electrolyzer also requires a considerably low voltage of 1.58 V at 10 mA cm-2 for overall water splitting. This study affords a rational strategy to develop water-alkali electrolyzers with great complexity for large-scale water-splitting systems.

14.
Curr Microbiol ; 79(10): 293, 2022 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-35972650

RESUMO

Ursolic acid (UA) exists in a variety of medicinal plants. UA exhibits antimicrobial activity against several microorganisms; however, little is known regarding the potential antifungal effect of UA on Cryptococcus neoformans (C. neoformans). The antifungal and antibiofilm activities of UA on C. neoformans H99 were evaluated in this study. Minimum inhibitory concentration (MIC) of UA against C. neoformans H99 was determined by microdilution technique, and its action mode was elucidated by clarifying the variations in cell membrane integrity, capsule, and melanin production. Moreover, the inhibition and dispersal effects of UA on biofilm formation and mature biofilms by C. neoformans H99 were evaluated using crystal violet (CV) assay, optical microscopy, field emission scanning electron microscopy and confocal laser scanning microscopy. The results indicated that the MIC value of UA against C. neoformans H99 was 0.25 mg/mL. UA disrupted the cell membrane integrity, inhibited the capsule and melanin production of C. neoformans H99 in a concentration-dependent manner. Further, UA presented the inhibitory effect on biofilm formation and dispersed mature biofilms, as well as compromised the cell membrane integrity of C. neoformans H99 cells within biofilms. Together, these results indicate that UA might be a potential therapeutic option for the treatment of C. neoformans-related infections.


Assuntos
Criptococose , Cryptococcus neoformans , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Biofilmes , Criptococose/tratamento farmacológico , Cryptococcus neoformans/metabolismo , Melaninas/metabolismo , Melaninas/farmacologia , Testes de Sensibilidade Microbiana , Triterpenos , Ácido Ursólico
15.
Angew Chem Int Ed Engl ; 61(8): e202113203, 2022 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-34921485

RESUMO

Herein, we report the synthesis, structural analysis, optical and chiroptical properties of a novel quadruple helicene, which has two [6] and two [7]helicene moieties fused in a contorted framework of 92 sp2 carbon atoms. It was synthesized by the Scholl reaction of a perylene-containing substrate with the formation of eight carbon-carbon bonds on the perylene unit in a single synthetic operation. Chemical oxidation of the quadruple helicene with tris(4-bromophenyl)ammoniumyl hexachloroantimonate resulted in an air-stable dication, which exhibits the same helicity in its four helicene moieties as unambiguously identified by single-crystal X-ray crystallography. The quadruple helicene exhibits unusual near-infrared absorption and emission with absorption and emission maxima at 848 nm and 977 nm, respectively, and its isolated enantiomers exhibit electronic circular dichroism in the near-infrared and visible-light regions.

16.
Zhongguo Yi Liao Qi Xie Za Zhi ; 46(5): 517-522, 2022 Sep 30.
Artigo em Zh | MEDLINE | ID: mdl-36254479

RESUMO

At present, heavy ion is an ideal radiation for cancer treatment, and carbon ion is used in the treatment of many kinds of cancer due to its higher relative biological effect value. In 2019, Wuwei heavy ion center built the first medical heavy ion accelerator-carbon ion radiotherapy system in China, and obtained the registration license from the National Medical Products Administration, and officially received cancer patients in March 2020. This study introduced the development and application of the first carbon ion radiotherapy system in China.


Assuntos
Radioterapia com Íons Pesados , Íons Pesados , Neoplasias , Carbono , China , Humanos , Neoplasias/radioterapia
17.
J Am Chem Soc ; 143(13): 5231-5238, 2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33764047

RESUMO

This study explores a bottom-up approach toward negatively curved carbon allotropes from octabenzo[8]circulene, a negatively curved nanographene. Stepwise chemical reduction reactions of octabenzo[8]circulene with alkali metals lead to a unique highly reduced hydrocarbon pentaanion, which is revealed by X-ray crystallography suggesting a local view for the reduction and alkali metal intercalation processes of negatively curved carbon allotropes. Polymerization of the tetrabromo derivative of octabenzo[8]circulene by the nickel-mediated Yamamoto coupling reaction results in a new type of porous carbon-rich material, which consists of a covalent network of negatively curved nanographenes. It has a specific surface area of 732 m2 g-1 and functions as anode material for lithium ion batteries exhibiting a maximum capacity of 830 mAh·g-1 at a current density of 100 mA·g-1. These results indicate that this covalent network presents the key structural and functional features of negatively curved carbon allotropes.

18.
Angew Chem Int Ed Engl ; 60(39): 21289-21294, 2021 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-34343393

RESUMO

Replacement of the allylic C=C-C unit with a N-B-N unit at each of the three zigzag edges of [4]triangulene gives rise to B3 N6 -[4]triangulene, which is envisioned to represent a key structural unit of a new hypothetical boron carbon nitride (BC4 N). A tert-butylated B3 N6 -[4]triangulene has been successfully synthesized by three-fold nitrogen-directed borylation, and the X-ray crystallographic analysis indicates that its slightly bent triangular polycyclic framework can be viewed as a 1,3,5-triphenylbenzene connected by three 4π-electron N-B-N units. The HN-B-NH moiety provides a dual hydrogen-bond donor, which forms H-bonds with halide or carboxylate anions in solution, and form DD-AA hydrogen-bond arrays with 2,7-di(tert-butyl)-pyrene-4,5,9,10-tetraone in the co-crystal. Moreover, the blue fluorescence of B3 N6 -[4]triangulene in solution is responsive to binding p-nitrobenzoate anion through hydrogen bonds.

19.
Angew Chem Int Ed Engl ; 60(45): 24124-24130, 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34519417

RESUMO

The synthesis of new carbazole-fused polycyclic aromatics with interesting geometry and useful properties was explored using Scholl reactions. As found from the Scholl reactions of substrates having two carbazole units linked at different positions through o-phenylene, oxidative coupling of carbazole units occurred in a regioselective manner with new carbon-carbon bonds preferably formed at C3 and C4 in N-alkyl carbazoles. A new N-containing aromatic bowl was characterized by single-crystal X-ray crystallography, and new p-type organic semiconductors exhibited field effect mobility of up to 0.070 cm2 V-1 s-1 in solution-processed thin-film transistors.

20.
Angew Chem Int Ed Engl ; 60(18): 10311-10318, 2021 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-33599364

RESUMO

Zigzag carbon nanobelts are a long-sought-after target for organic synthesis. Herein we report new strategies for designing and synthesizing unprecedented zigzag carbon nanobelts, which present a wave-like arrangement of hexagons in the unrolled lattice of (n,0) single wall carbon nanotubes (n=16 or 24). The precursors of these zigzag carbon nanobelts are hybrid cyclic arylene oligomers consisting of meta-phenylene and 2,6-naphthalenylene as well as para-phenylene units. The Scholl reactions of these cyclic arylene oligomers form multiple carbon-carbon bonds selectively at the α-positions of naphthalene units resulting in the corresponding zigzag carbon nanobelts. As monitored with fluorescence spectroscopy, one of these nanobelts binds C60 with an association constant as high as (6.6±1.1)×106  M-1 in the solution in toluene. Computational studies combining linear regression analysis and hypothetical homodesmotic reactions reveal that these zigzag nanobelts have strain in the range of 67.5 to 69.6 kcal mol-1 , and the ladderization step through Scholl reactions is accompanied by increase of strain as large as 69.6 kcal mol-1 . The successful synthesis of these nanobelts demonstrates the powerfulness and efficiency of Scholl reactions in synthesizing strained polycyclic aromatics.

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