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Mild and inexpensive copper-catalyzed aromatization-driven ring-opening amination and oxygenation of spiro dihydroquinazolinones are presented, respectively. These protocols provide facile and atom-economical access to the aminated and the carbonyl-containing quinazolin-4(3H)-ones in good yields with good functional group compatibility, which are difficult to obtain by conventional methods. Remarkably, a telescoped procedure involving the condensation and the ring-opening/functionalization for simple cycloalkanone was found to be accessible. Mechanistic studies suggest a radical pathway for this transformation.
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Candida auris, an emerging and multidrug-resistant fungal pathogen, has led to numerous outbreaks in China. While the resistance mechanisms against azole and amphotericin B have been studied, the development of drug resistance in this pathogen remains poorly understood, particularly in in vivo-generated drug-resistant strains. This study employed pathogen whole-genome sequencing to investigate the epidemiology and drug-resistance mutations of C. auris using 16 strains isolated from two patients. Identification was conducted through Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and antimicrobial susceptibilities were assessed using broth microdilution and Sensititre YeastOne YO10. Whole-genome sequencing revealed that all isolates belonged to the South Asian lineage, displaying genetic heterogeneity. Despite low genetic variability among patient isolates, notable mutations were identified, including Y132F in ERG11 and A585S in TAC1b, likely linked to increased fluconazole resistance. Strains from patient B also carried F214L in TAC1b, resulting in a consistent voriconazole minimum inhibitory concentration of 4 µg/mL across all isolates. Furthermore, a novel frameshift mutation in the SNG1 gene was observed in amphotericin B-resistant isolates compared to susceptible ones. Our findings suggest the potential transmission of C. auris and emphasize the need to explore variations related to antifungal resistance. This involves analyzing genomic mutations and karyotypes, especially in vivo, to compare sensitive and resistant strains. Further monitoring and validation efforts are crucial for a comprehensive understanding of the mechanisms of drug resistance in C. auris.
Assuntos
Antifúngicos , Candidíase , Humanos , Antifúngicos/farmacologia , Candidíase/microbiologia , Candida auris , Candida , Anfotericina B/farmacologia , Farmacorresistência Fúngica/genética , Testes de Sensibilidade MicrobianaRESUMO
A photoredox-catalyzed sequential decarboxylative/defluorinative aminoalkylation of CF3-alkenes with N-arylglycines is described. This metal-free and redox-neutral protocol provided efficient access to the monofluoroalkenyl-1,5-diamines in good yields with excellent functional group compatibility. Mechanistic studies revealed that the reaction proceeds via a radical pathway with the gem-difluoroalkenyl amine as an intermediate.
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An efficient synthesis of quinoxaline-fused aza-bicyclo[2.1.1]hexanes bearing multiple quaternary carbon centers via the intermolecular [2π+2σ] cycloaddition of bicyclo[1.1.0]butanes and quinoxalin-2(1H)-ones, facilitated by Lewis acid catalysis, is presented. This reaction is carried out under mild conditions and exhibits a broad substrate scope and excellent functional group tolerance.
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A sustainable, cyanide-free synthesis of alkyl nitriles via the aerobic oxidative deconstruction of unstrained cycloalkanones with ammonium salts has been developed. Using inexpensive and stable ammonium salts as the nitrogen source, a variety of alkyl nitriles containing a distal carbonyl group were obtained in good yields under visible-light-promoted iron catalysis. This protocol is characterized by mild conditions, abundant and environmentally benign materials, and high atom and step economy with minimal waste generation. The primary mechanism study revealed that 1O2 is likely to be involved in this reaction.
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ABSTRACT: Male infertility is a global issue caused by poor sperm quality, particularly motility. Enhancement of the sperm quality may improve the fertilization rate in assisted reproductive technology (ART) treatment. Scriptaid, with a novel human sperm motility-stimulating activity, has been investigated as a prospective agent for improving sperm quality and fertilization rate in ART. We evaluated the effects of Scriptaid on asthenozoospermic (AZS) semen, including its impact on motility stimulation and protective effects on cryopreservation and duration of motility, by computer-aided sperm analysis (CASA). Sperm quality improvement by Scriptaid was characterized by increased hyaluronan-binding activity, tyrosine phosphorylation, adenosine triphosphate (ATP) concentration, mitochondrial membrane potential, and an ameliorated AZS fertilization rate in clinical intracytoplasmic sperm injection (ICSI) experiments. Furthermore, our identification of active Scriptaid analogs and different metabolites induced by Scriptaid in spermatozoa lays a solid foundation for the future biomechanical exploration of sperm function. In summary, Scriptaid is a potential candidate for the treatment of male infertility in vitro as it improves sperm quality, prolongs sperm viability, and increases the fertilization rate.
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A photoredox-catalyzed alkylarylation of activated alkenes via a radical C-C bond cleavage/Truce-Smiles rearrangement cascade is developed. The protocol features mild and redox-neutral conditions, broad substrate scope and excellent functional group compatibility, providing a facile and efficient approach to the long-chain distal keto-amides with all-carbon quaternary centers at the alpha position.
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Aromatization-driven deconstruction and functionalization of spiro dihydroquinazolinones via dual photoredox/nickel catalysis is developed. The aromatization effect was introduced to synergistically drive unstrained cyclic C-C bond cleavage, with the aim of overcoming the ring-size limitation of nitrogen-centered radical induced deconstruction of carbocycles. Herein, we demonstrate the synergistic photoredox/nickel catalyzed deconstructive cross-coupling of spiro dihydroquinazolinones with organic halides. Remarkably, structurally diverse organic halides including aryl, alkenyl, alkynyl, and alkyl bromides were compatible for the coupling. In addition, this protocol is also characterized by its mild and redox-neutral conditions, excellent functional group compatibility, high atom economy, and easy scalability. A telescoped procedure involving condensation and ring-opening/coupling was found to be accessible. This work provides a complementary strategy to the existing radical-mediated C-C bond cleavage of unstrained carbocycles.
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Metal-free, photoredox-catalyzed aromatization-driven deconstructive functionalization of spiro-dihydroquinazolinones with α-CF3 alkenes is presented. The readily available spiro-dihydroquinazolinones reacted efficiently with α-CF3 alkenes during photocatalysis to give the gem-difluoroallylated and the CF3-containing quinazolin-4(3H)-ones in good yields with excellent chemoselectivity. The selectivity depends on the electron effect of substituents in α-CF3 alkenes. A wide range of four-, five-, six-, seven-, eight- and twelve-membered spiro-dihydroquinazolinones were compatible with this transformation. The protocol is also characterized by the mild and redox-neutral reaction conditions, good functional group compatibility and excellent atom economy. Mechanistic studies revealed that the reaction proceeds via a radical pathway.
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N-doped TiO2/carbon composites (N-TiPC) have shown excellent photodegradation performances to the organic contaminants but are limited by the multistage preparation (i.e., preparation of porous carbon, preparation of N-doped TiO2, and loading of N-doped TiO2 on porous carbon). Here, we develop a handy way by combining the Pickering emulsion-gel template route and chelation reaction of polysaccharides. The N-TiPC is obtained by calcinating pectin/Dl-serine hydrazide hydrochloride (SHH)-Ti4+ chelate and is further described by modern characterization techniques. The results show that the N atom is successfully doped into the TiO2 lattice, and the bandgap value of N-TiPC is reduced to 2.3 eV. Moreover, the particle size of N-TiPC remains about 10 nm. The configurations of the composites are simulated using DFT calculation. The photocatalytic experiments show that N-TiPC has a high removal efficiency for methylene blue (MB) and oxytetracycline hydrochloride (OTC-HCL). The removal ratios of MB (20 mg/L, 50 mL) and OTC-HCL (30 mg/L, 50 mL) are 99.41 % and 78.29 %, respectively. The cyclic experiments show that the photocatalyst has good stability. Overall, this study provides a handy way to form N-TiPC with enhanced photodegradation performances. It can also be promoted to other macromolecules such as cellulose and its derivatives, sodium alginate, chitosan, lignin, etc.
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This study aimed to investigate the association between irritable bowel syndrome (IBS) and Parkinson's disease (PD) utilizing prospective cohort study and Mendelian randomization. The dataset contained a substantial cohort of 426,911 participants from the UK Biobank, discussing the association between IBS and PD with Cox proportional hazards models and case-control analysis while adjusting for covariates such as age, gender, ethnicity and education level. In univariate Cox regression model, the risk of PD was reduced in IBS patients (HR: 0.774, 95%CI: 0.625-0.956, P = 0.017), but the statistical significance diminished in the three models after adjusting for other variables. In a few subgroup analyses, IBS patients are less likely to develop into PD, and patients diagnosed with IBS after 2000 also had a lower risk (HR: 0.633, 95%CI: 0.403-0.994, P = 0.047) of subsequently developing PD. In addition, we matched five healthy control participants based on gender and age at the end of the study for each IBS patient diagnosed during the follow-up period, and logistic regression results (OR:1.239, 95%CI: 0.896-1.680, P = 0.181) showed that IBS was not associated with the risk of PD. Mendelian randomization did not find significant evidence of the causal relationship between IBS and Parkinson's disease (OR: 0.801, 95%CI: 0.570-1.278, P = 0.204). Overall, we suggest that IBS status is not associated with the risk of developing PD, and that these findings provide valuable insights into the clinical management and resource allocation of patients with IBS.
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@#Abstract: Objective To analyze the characteristics of bloodstream infection of Listeria monocytogenes and provide basis for the diagnosis and treatment of the disease. Methods We retrospectively analyzed the cases of Listeria monomyrhosi bloodstream infection in Peking Union Medical College Hospital (PUMCH) from April 2012 to April 2022. The age, sex, onset time, underlying disease, symptoms, diagnosis, treatment and prognosis of the patients were analyzed, as well as the changes of white blood cells (WBC), neutrophils, lymphocytes, and C-reactive protein (CRP) before and after anti-infection treatment. Results Fifty cases of Listeria monocytogenes bloodstream infection confirmed by blood culture were involved. The age of patients ranged from 0 to 82 (43.7±20.0) years old, among whom 20.0% were over 60 years old. The onset time of patients was the highest in spring (44.0%), followed by winter (24.0%), and relatively fewer in summer and autumn (14.0%-18.0%). The median diagnosis time was 3 days (1-60 days). After the etiological diagnosis, 45 patients (90.0%) had underlying diseases or pregnancy status, and 45 patients were adjusted to the target antibacterial treatment mainly with carbapenems (48.9%) and penicillins (44.4%). The level of WBC, neutrophils, lymphocytes, monocytes, and CRP after treatment were significantly lower than those pre-treatments (P<0.05). Among all patients, 36 cases (72.0%) were treated according to the Antimicrobial Treatment Guidelines for Fever Sanford, of which 26 cases (72.2%) were discharged from the hospital, two cases died, one case was transferred to other hospitals, and 7 cases had a poor prognosis. Conclusions Autoimmune diseases, tumor diseases, pregnant patients are susceptible to Listeria monocytogenes infection. Penicillins are the first choice for effective empiric therapy. For the patients allergic to penicillins, trimethoprim/sulfamethoxazole or meropenem could be used.