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1.
J Org Chem ; 89(7): 4530-4537, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38483270

RESUMO

A copper-catalyzed method for the dehydrogenation of various nitrogen-containing heterocycles to furnish quinolines and indoles has been developed. A range of 1,2,3,4-tetrahydroquinolines underwent dehydrogenation by employing 2 mol % of copper complex Cat 3 as a catalyst and using O2 as an oxidant at 120 °C in 1,2-dichlorobenzene to afford the desired quinolines. The method enables the dehydrogenation of a variety of indolines in the presence of 2 mol % of copper complex Cat 2, using 10 mol % of TEMPO as an additive and O2 as an oxidant under room temperature in tetrahydrofuran to furnish indoles in high yields. Mechanistic studies suggested that the dehydrogenative activity is ascribed to the formation of a copper(II) active species from copper(I) complexes oxidized by O2, which was proved by high-resolution mass spectrometry (HRMS). The copper-catalyzed dehydrogenation reaction proceeds via a superoxide radical anion (·O2-) as proved by electron paramagnetic resonance (EPR) spectrometry. In situ infrared spectroscopy revealed that the dihydroquinoline intermediate was formed in the dehydrogenation of 1,2,3,4-tetrahydroquinolines.

2.
J Am Chem Soc ; 145(6): 3294-3300, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36724205

RESUMO

N-Demethylation of trialkylamines is a useful transformation, but typically requires harsh reaction conditions and stepwise procedures, as well as judicious protection of labile functional groups. Herein we report a mild, catalytic approach for the demethylation of trialkylamines by utilizing photoinduced nickel catalysis wherein C(sp2)-bromides serve as hydrogen-atom transfer (HAT) reagents. This method achieves direct demethylation of trialkylamines with wide functional group compatibility, making it highly suitable for late-stage derivatization of complex molecules. Mechanistic investigations provide evidence that C(sp2) radicals generated via photoinduced Ni-C(sp2) bond homolysis are involved in hydrogen atom abstraction from trialkylamines. Utilizing steric control of the C(sp2)-bromides, our HAT approach achieves demethylation with excellent site selectivity in the presence of benzyl-substituted amines, which is complementary to the selectivity of classical approaches that afford debenzylation product instead.

3.
Curr Microbiol ; 80(12): 378, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37861738

RESUMO

Endophthalmitis is an acute inflammatory intraocular condition that can cause permanent vision loss. The treatment strategy and visual outcome partly depend on the identification of the agents of pathogens. In this study, metagenomic sequencing was conducted to investigate the microbial and antibiotic resistance genes (ARGs) composition in the vitreous (intraocular body fluid) of an endophthalmitis patient, who progressed rapidly and accompanied by severe pain. Metagenomic sequencing data revealed that the vitreous sample was predominated by Streptococcus, with a low-diversity microbiome in the vitreous. This strain harbor's the ARGs mainly against beta-lactam, macrolide-lincosamide-streptogramin, and multidrug. Additionally, metagenome-assembled genome sequence of Streptococcus sp. v1. nov. was identified. The Tetra Correlation Search (TCS) analysis uncovered that the closest relative of the Streptococcus sp. v1. nov. was Streptococcus mitis SK321. Pan/core genome analysis for Streptococcus sp. v1. nov. and TCS top 25 hits strains revealed that most unique genes of Streptococcus sp. v1. nov. were linked to ATP-binding cassette transport system, which could indicate unique virulence and pathogenic potentials of Streptococcus sp. v1. nov. In addition, a total of 7 virulence factors were identified, and the overwhelming of them were classified into "offensive virulence factors". The high pathogenicity of Streptococcus sp. v1. nov. could be a reason for the patient's rapid disease progression. Our study was first isolated an ocular pathogen with highly virulent based on metagenomic sequencing and bioinformatics analysis, which has important reference value for revealing the composition and genome characteristics of pathogens in endophthalmitis patient in the future.


Assuntos
Endoftalmite , Streptococcus , Humanos , Streptococcus/genética , Streptococcus mitis , Genômica , Fatores de Virulência/genética , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , DNA Bacteriano/genética
4.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 54(2): 304-309, 2023 Mar.
Artigo em Zh | MEDLINE | ID: mdl-36949690

RESUMO

Objective: To explore the characteristics of patients with obstructive sleep apnea (OSA) and comorbid primary aldosteronism (PA) and to explore the relevant factors affecting plasma aldosterone concentration. Methods: A total of 105 patients diagnosed with PA and admitted at West China Hospital, Sichuan University between January 2016 and December 2021 were retrospectively analyzed. The subjects were divided into a PA with comorbid snoring group (n=20) and a PA with comorbid OSA group (n=85) based on the results of polysomnography (PSG). The PA with comorbid OSA group was further divided into mild, moderate, and severe subgroups according to the apnea-hypopnea index (AHI). A total of 85 outpatients diagnosed with OSA were included as the control group. Demographic, clinical, biochemical, and PSG data were compared between the groups. Results: Compared with patients with only OSA, a significantly higher proportion of patients with OSA and comorbid PA had hypertension and elevated levels of systolic and diastolic blood pressure (P<0.05). In addition, patients with OSA and comorbid PA had significantly increased AHI and significantly decreased mean oxygen saturation and sleep efficiency (P<0.05). The more severe the OSA was, the higher levels of BMI, cholesterol, low-density lipoprotein, and uric acid the PA patients had. Linear regression analysis showed that the lowest oxygen saturation (ß=-0.222, P=0.045) was negatively correlated with plasma aldosterone concentration. Conclusion: Comorbidity with PA can aggravate the clinical manifestations of OSA, while OSA further disrupted the metabolism of lipids and uric acid in PA patients. Plasma aldosterone concentrations in patients with comorbid OSA and PA were affected by the lowest oxygen saturation level.


Assuntos
Hiperaldosteronismo , Apneia Obstrutiva do Sono , Humanos , Aldosterona , Estudos Retrospectivos , Ácido Úrico , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/epidemiologia , Comorbidade , Hiperaldosteronismo/complicações , Hiperaldosteronismo/epidemiologia , Hiperaldosteronismo/diagnóstico
5.
Crit Rev Eukaryot Gene Expr ; 32(5): 77-91, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35993946

RESUMO

Lung cancer is a fatal disease with high morbidity and mortality. As a major type of non-small cell lung cancer (NSCLC), lung adenocarcinoma (LUAD) has come into the focus of the biological and clinical research. Nevertheless, potential functions of N6-methyladenosine (m6A) methylation-related long non-coding RNAs (lncRNAs) in the tumor immune microenvironment (TIME) remain unclear. Here, we analyzed RNA-seq data of 522 samples from the TCGA-LUAD project. Based on integrative analyses of lncRNA, immune, and clinical profiles, we developed a computational method to determine the characteristics of lncRNAs as an indicators of immune cell infiltration in LUAD patients. Subsequently, we investigated the influence of m6A-related lncRNAs on prognosis and immunotherapy in patients with LUAD. We identified 24 m6A-related lncRNAs that were related to LUAD prognosis and clustered in two molecular subtypes (clusters 1 and 2). Our results suggest that cluster 1 was significantly related to downregulation of PD-L1, enhancement of immune cell infiltration, and good prognosis. Furthermore, p53 and mTOR pathways were enriched in cluster 1, whereas in the cluster 2, PPAR was uncommonly enriched. Patients with LUAD who had lower risk scores exhibited higher immunoscores and lower expression levels of programmed cell death-ligand 1, compared with patients who had higher risk scores. Finally, m6A-related lncRNAs were implicated in the TIME; our findings indicate that these lncRNAs are critical within the TIME in LUAD. These signatures are promising as potential targets for improved LUAD immunotherapy.


Assuntos
Adenocarcinoma , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , RNA Longo não Codificante , Adenocarcinoma/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Pulmão , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , RNA Longo não Codificante/genética , Microambiente Tumoral/genética
6.
Anim Genet ; 53(5): 599-612, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35735069

RESUMO

With the improvement in sequencing technology and the decrease in sequencing cost, increasing amounts of genomic data for pigs have been uploaded to public databases. However, no researchers have to date integrated all currently available data to uncover the global genetic status of pigs. Meanwhile, little is known about the introgression from European to Chinese pigs and its underlying influences. Therefore, we integrated the effective genotype data of 3907 pigs from 193 populations worldwide using population genetic analysis, gene flow analysis and a sharing-IBD study. These findings illustrate not only the population structure of 59 Chinese native breeds and others but also the amounts of gene flow and introgression that have occurred between Western and Chinese pigs. In addition, we demonstrate the presence of introgressed European haplotypes in Chinese indigenous breeds and identify relevant introgressed regions that contain genes associated with growth and feed efficiency. Moreover, we compare the introgression patterns of Western and Chinese pigs and further discuss possible explanations for why the level of introgression differs between Chinese pig breeds and Western modern breeds. Collectively, this study provides a fine global population structure analysis of pigs and presents evidence of European pigs being interbred with local breeds in China.


Assuntos
Polimorfismo de Nucleotídeo Único , Sus scrofa , Animais , China , Variação Genética , Genética Populacional , Haplótipos , Sus scrofa/genética , Suínos/genética
7.
J Am Chem Soc ; 143(40): 16364-16369, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-34590864

RESUMO

The diversity and wide availability of trialkylamines render them ideal sources for rapid construction of complex amine architectures. Herein, we report that a nickel/photoredox dual catalysis strategy affects site-selective α-arylation of various trialkylamines. Our catalytic system shows exclusive N-Me selectivity with a wide range of trialkylamines under mild conditions, even in the context of late-stage arylation of pharmaceutical compounds bearing this common structural motif. Mechanistic studies indicate the unconventional behavior of Ni catalyst upon intercepting the α-amino radicals, in which only the primary α-amino radical undergoes a successful cross-coupling process.


Assuntos
Níquel
8.
J Am Chem Soc ; 143(45): 18952-18959, 2021 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-34738467

RESUMO

Trialkylamines are widely found in naturally occurring alkaloids, synthetic agrochemicals, biological probes, and especially pharmaceuticals agents and preclinical candidates. Despite the recent breakthrough of catalytic alkylation of dialkylamines, the selective α-C(sp3)-H bond functionalization of widely available trialkylamine scaffolds holds promise to streamline complex trialkylamine synthesis, accelerate drug discovery, and execute late-stage pharmaceutical modification with complementary reactivity. However, the canonical methods always result in functionalization at the less-crowded site. Herein, we describe a solution to switch the reaction site through fundamentally overcoming the steric control that dominates such processes. By rapidly establishing an equilibrium between α-amino C(sp3)-H bonds and a highly electrophilic thiol radical via reversible hydrogen atom transfer, we leverage a slower radical-trapping step with electron-deficient olefins to selectively forge a C(sp3)-C(sp3) bond with the more-crowded α-amino radical, with the overall selectivity guided by the Curtin-Hammett principle. This subtle reaction profile has unlocked a new strategic concept in direct C-H functionalization arena for forging C-C bonds from a diverse set of trialkylamines with high levels of site selectivity and preparative utility. Simple correlation of site selectivity and 13C NMR shift serves as a qualitative predictive guide. The broad consequences of this dynamic system, together with the ability to forge N-substituted quaternary carbon centers and implement late-stage functionalization techniques, hold potential to streamline complex trialkylamine synthesis and accelerate small-molecule drug discovery.


Assuntos
Aminas/síntese química , Hidrogênio/química , Alquilação , Catálise , Complexos de Coordenação/química , Radicais Livres/química , Irídio/química , Modelos Químicos , Silanos/química , Compostos de Sulfidrila/química
9.
Int J Neuropsychopharmacol ; 24(8): 666-676, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34000028

RESUMO

BACKGROUND: The restraint water immersion stress (RWIS) model includes both psychological and physical stimulation, which may lead to gastrointestinal disorders and cause gastric mucosal damage. The ventrolateral periaqueductal gray (VLPAG) contributes to gastrointestinal function, but whether it is involved in RWIS-induced gastric mucosal damage has not yet been reported. METHODS: The expression of glial fibrillary acidic protein, neuronal c-Fos, and phosphorylated extracellular signal regulated kinase 1/2 in the VLPAG after RWIS was assessed using western blotting and immunocytochemical staining methods. Lateral ventricle injection of astrocytic toxin L-a-aminoadipate and treatment with extracellular signal-regulated kinase (ERK)1/2 signaling pathway inhibitor PD98059 were further used to study protein expression and distribution in the VLPAG after RWIS. RESULTS: The expression of c-Fos, glial fibrillary acidic protein, and phosphorylated extracellular signal regulated kinase 1/2 in the VLPAG significantly increased following RWIS and peaked at 1 hour after RWIS. Lateral ventricle injection of the astrocytic toxin L-a-aminoadipate significantly alleviated gastric mucosal injury and decreased the activation of neurons and astrocytes. Treatment with the ERK1/2 signaling pathway inhibitor PD98059 obviously suppressed gastric mucosal damage as well as the RWIS-induced activation of neurons and astrocytes in the VLPAG. CONCLUSIONS: These results suggested that activation of VLPAG neurons and astrocytes induced by RWIS through the ERK1/2 signaling pathway may play a critical role in RWIS-induced gastric mucosa damage.


Assuntos
Astrócitos/fisiologia , Mucosa Gástrica/fisiopatologia , Sistema de Sinalização das MAP Quinases/fisiologia , Neurônios/fisiologia , Substância Cinzenta Periaquedutal/metabolismo , Substância Cinzenta Periaquedutal/fisiopatologia , Inibidores de Proteínas Quinases/farmacologia , Gastropatias , Estresse Psicológico , Animais , Astrócitos/efeitos dos fármacos , Mucosa Gástrica/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Neurônios/efeitos dos fármacos , Substância Cinzenta Periaquedutal/efeitos dos fármacos , Ratos , Ratos Wistar , Restrição Física , Gastropatias/etiologia , Gastropatias/metabolismo , Gastropatias/fisiopatologia , Estresse Psicológico/complicações , Estresse Psicológico/metabolismo , Estresse Psicológico/fisiopatologia
10.
Crit Care ; 25(1): 167, 2021 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-33964934

RESUMO

BACKGROUND: Mortality and other clinical outcomes between culture-negative and culture-positive septic patients have been documented inconsistently and are very controversial. A systematic review and meta-analysis was performed to compare the clinical outcomes of culture-negative and culture-positive sepsis or septic shock. METHODS: We searched the PubMed, Cochrane and Embase databases for studies from inception to the 1st of January 2021. We included studies involving patients with sepsis or septic shock. All authors reported our primary outcome of all-cause mortality and clearly compared culture-negative versus culture-positive patients with clinically relevant secondary outcomes (ICU length of stay, hospital length of stay, mechanical ventilation requirements, mechanical ventilation duration and renal replacement requirements). Results were expressed as odds ratio (OR) and mean difference (MD) with accompanying 95% confidence interval (CI). RESULTS: Seven studies including 22,655 patients were included. The primary outcome of this meta-analysis showed that there was no statistically significant difference in the all-cause mortality between two groups (OR = 0.95; 95% CI, 0.88 to 1.01; P = 0.12; Chi-2 = 30.71; I2 = 80%). Secondary outcomes demonstrated that there was no statistically significant difference in the ICU length of stay (MD = - 0.19;95% CI, - 0.42 to 0.04; P = 0.10;Chi-2 = 5.73; I2 = 48%), mechanical ventilation requirements (OR = 1.02; 95% CI, 0.94 to 1.11; P = 0.61; Chi2 = 6.32; I2 = 53%) and renal replacement requirements (OR = 0.82; 95% CI, 0.67 to 1.01; P = 0.06; Chi-2 = 1.21; I2 = 0%) between two groups. The hospital length of stay of culture-positive group was longer than that of the culture-negative group (MD = - 3.48;95% CI, - 4.34 to - 2.63; P < 0.00001;Chi-2 = 1.03; I2 = 0%). The mechanical ventilation duration of culture-positive group was longer than that of the culture-negative group (MD = - 0.64;95% CI, - 0.88 to - 0.4; P < 0.00001;Chi-2 = 4.86; I2 = 38%). CONCLUSIONS: Culture positivity or negativity was not associated with mortality of sepsis or septic shock patients. Furthermore, culture-positive septic patients had similar ICU length of stay, mechanical ventilation requirements and renal replacement requirements as those culture-negative patients. The hospital length of stay and mechanical ventilation duration of culture-positive septic patients were both longer than that of the culture-negative patients. Further large-scale studies are still required to confirm these results.


Assuntos
Hemocultura/classificação , Sepse/complicações , Humanos , Sepse/classificação
11.
Med Sci Monit ; 27: e926565, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33408319

RESUMO

BACKGROUND The purpose of this study was to compare circulating tumor cells (CTCs)/circulating tumor microemboli (CTM) detection rates of the CellSearch and CTC-Biopsy systems in patients with gastric cancer (GC). We also investigated potential correlations between clinicopathological characteristics and prognosis in patients with GC. MATERIAL AND METHODS This prospective study was conducted at the Shandong Institute of Cancer Prevention and Control in China. Fifty-nine patients with GC and 22 healthy volunteers were recruited and their peripheral blood samples were examined by the CTC-Biopsy system and CellSearch system for CTC. RESULTS The rate of detection of CTCs/CTM was significantly higher with the CTC-Biopsy system than with the CellSearch system (59.32% vs. 27.12%, P<0.001). The Kappa value was 0.179, indicating poor consistency. CTCs detected with the CellSearch system in patients with stage III/IV GC was significantly correlated with neutrophil count (P=0.020), neutrophil/lymphocyte ratio (N/L ratio) (P=0.009), CA19-9 (P=0.049), tumor size (P=0.026), and the extent of vascular invasion (P=0.007). CTCs detected with the CTC-Biopsy system correlated with tumor differentiation (P=0.010). CTM in patients with stage I/II GC and stage II/IV GC correlated with CEA (P=0.004) and tumor differentiation (P=0.030), respectively. A CTC count >3 detected with the CellSearch system, and not the CTC-Biopsy system, correlated with reduced progression-free survival and overall survival. CONCLUSIONS The CTC-Biopsy system was superior to the CellSearch system for detecting CTCs in GC patients. CTM were detected with the CTC-Biopsy system but not with the CellSearch system. CTCs detected with the CellSearch system correlated with various clinicopathological factors and long-term survival outcomes.


Assuntos
Células Neoplásicas Circulantes/patologia , Neoplasias Gástricas/sangue , Neoplasias Gástricas/patologia , Estômago/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Contagem de Células , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Intervalo Livre de Progressão , Neoplasias Gástricas/terapia
12.
Int J Mol Sci ; 21(21)2020 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-33182370

RESUMO

CDK5RAP3 was regarded as the most significant regulator of cellular responses against heat stress, which is associated with dysfunctions of the immune system and animal susceptibility to disease. Despite this, little known about how CDK5RAP3 regulates heat stress response. In this study, CDK5RAP3 conditional Knockout (CKO) mice, CDK5RAP3-/- mouse embryo fibroblasts (MEFs) and bovine mammary epithelial cells (BMECs) were used as an in vitro and in vivo model, respectively to reveal the role of CDK5RAP3 in regulating the heat stress response. The deletion of CDK5RAP3 unexpectedly caused animal lethality after 1.5-h heat stimulations. Furthermore, BMECs were re-cultured for eight hours after heat stress and was found that the expression of CDK5RAP3 and HSPs showed a similar fluctuating pattern of increase (0-2, 4-6 h) and decrease (2-4, 6-8 h). In addition to the remarkably enhanced expression of heat shock protein, apoptosis rate and endoplasmic reticulum stress, the deletion of CDK5RAP3 also affected nucleoplasmic translocation and trimer formation of heat shock factor 1 (HSF1). These programs were further confirmed in the mammary gland of CDK5RAP3 CKO mice and CDK5RAP3-/- MEFs as well. Interestingly, genetic silencing of HSF1 downregulated CDK5RAP3 expression in BMECs. Immunostaining and immunoprecipitation studies suggested a physical interaction between CDK5RAP3 and HSF1 being co-localized in the cytoplasm and nucleus. Besides, CDK5RAP3 also interacted with HSP90, suggesting an operative machinery at both transcriptional level and protein functionality of HSP90 per se. Together, our findings suggested that CDK5RAP3 works like a novel nucleoplasmic shuttle or molecular chaperone, deeply participating in HSF1-mediated heat stress response and protecting cells from heat injury.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Células Epiteliais/metabolismo , Fatores de Transcrição de Choque Térmico/metabolismo , Resposta ao Choque Térmico/fisiologia , Mamíferos/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Apoptose/fisiologia , Bovinos , Células Cultivadas , Regulação para Baixo/fisiologia , Estresse do Retículo Endoplasmático/fisiologia , Células Epiteliais/fisiologia , Feminino , Proteínas de Choque Térmico HSP90/metabolismo , Masculino , Mamíferos/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Chaperonas Moleculares/metabolismo , Ligação Proteica
13.
J Environ Manage ; 262: 110375, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32250829

RESUMO

The extensive application of antibiotics, and the occurrence and spread of antibiotic resistance genes (ARGs) shade health risks to human and animal. The long-term effects of sulfamethoxazole (SMX) and tetracycline (TC) on denitrification process were evaluated in this study, with the focus on nitrogen removal performance, microbial community and ARGs. Results showed that low-concentration SMX and TC (<0.2 mg L-1) initially caused a deterioration in nitrogen removal performance, while higher concentrations (0.4-20 mg L-1) of both antibiotics had no further inhibitory influences. The abundances of ARGs in both systems generally increased during the whole period, and most of them had significant correlations with intI1, especially efflux-pump genes. Castellaniella, which was the dominant genus under antibiotic pressure, might be potential resistant bacteria. These findings provide an insight into the toxic effects of different antibiotics on denitrification process, and guides future efforts to control antibiotics pollution in ecosystems.


Assuntos
Antibacterianos , Microbiota , Animais , Desnitrificação , Resistência Microbiana a Medicamentos , Genes Bacterianos
14.
Angew Chem Int Ed Engl ; 59(5): 2061-2065, 2020 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-31742879

RESUMO

A base-catalyzed reaction that enables stereoselective 1,1-silaboration of terminal alkynes is described. This method not only offers a new strategy to functionalize simple and readily accessible alkynes beyond 1,2-difunctionalization, but also provides an unconventional atom- and step-economical approach to rapidly and reliably access versatile geminal silylboranes in the absence of transition metals and with exquisite stereoselectivity.

15.
J Am Chem Soc ; 141(1): 127-132, 2019 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-30562018

RESUMO

A base-mediated protocol that allows for the site-selective sp2 C-H silylation of azines is described. This method is distinguished by its mild conditions, simplicity and excellent site-selective modulation for a diverse set of azines, even in the context of late-stage functionalization, while exhibiting orthogonal reactivity with classical silylation reactions.

16.
J Am Chem Soc ; 140(38): 12200-12209, 2018 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-30184423

RESUMO

Triplet ketone sensitizers are of central importance within the realm of photochemical transformations. Although the radical-type character of triplet excited states of diaryl ketones suggests the viability for triggering hydrogen-atom transfer (HAT) and single-electron transfer (SET) processes, among others, their use as multifaceted catalysts in C-C bond-formation via sp3 C-H functionalization of alkane feedstocks still remains rather unexplored. Herein, we unlock a modular photochemical platform for forging C( sp3)-C( sp2) and C( sp3)-C( sp3) linkages from abundant alkane sp3 C-H bonds as functional handles using the synergy between nickel catalysts and simple, cheap and modular diaryl ketones. This method is distinguished by its wide scope that is obtained from cheap catalysts and starting precursors, thus complementing existing inner-sphere C-H functionalization protocols or recent photoredox scenarios based on iridium polypyridyl complexes. Additionally, such a platform provides a new strategy for streamlining the synthesis of complex molecules with high levels of predictable site-selectivity and preparative utility. Mechanistic experiments suggest that sp3 C-H abstraction occurs via HAT from the ketone triplet excited state. We believe this study will contribute to a more systematic utilization of triplet excited ketones as catalysts in metallaphotoredox scenarios.

17.
J Sep Sci ; 40(2): 524-531, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27860231

RESUMO

Four kinds of poly(N-isopropylacrylamide)-grafted silicas with different grafting ratios and the same grafting density were prepared by atom transfer radical polymerization. The chemical groups in the stationary phase was verified by FTIR spectroscopy, and the content of elements was measured by elemental analysis. The grafting ratio of thermoresponsive chromatographic materials was measured by thermogravimetric analysis and was 2.36-21.10% mg/m2 . The retention behaviors of the stationary phase with different grafting ratios were evaluated by separating five kinds of steroids and ten kinds of different hydrophobic properties compounds. With the increase in grafting ratio, the retention time of analytes was prolonged in high-performance liquid chromatography. The results showed that grafting ratio had a significant influence on the separation effect under the same grafting density. And the optimal grafting ratio of poly(N-isopropylacrylamide) was 5.81-13.15%.

18.
Angew Chem Int Ed Engl ; 56(36): 10915-10919, 2017 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-28700104

RESUMO

A redox-neutral intermolecular dicarbofunctionalization of styrenes with CO2 at atmospheric pressure and carbon-centered radicals is described. This mild protocol results in multiple C-C bond-forming reactions from simple precursors in the absence of stoichiometric reductants, thus exploiting a previously unrecognized opportunity that complements existing catalytic carboxylation events.

19.
BMC Cancer ; 16(1): 754, 2016 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-27669688

RESUMO

BACKGROUND: Fluorouracil implants are widely used in peritoneal interstitial chemotherapy. Curative effects have been obtained, but implants have also caused some complications. CASE PRESENTATION: We performed an analysis of a 66-year-old male patient's case history, as well as conventional pathological analysis and Raman spectroscopic detection of the diaphragmatic tumor. We also analyzed the underlying causes of this condition to prevent complications and reduce misdiagnoses in future cases. The patient had a history of peritoneal fluorouracil implantation. Pathological analysis of the diaphragmatic mass revealed foreign particles, and Raman detection showed that the mass contained fluorouracil. CONCLUSION: Fluorouracil implants may persist due to the high concentrations of this drug used in peritoneal chemotherapy. This finding should provide guidance and improve the application of peritoneal implants. In clinical trials, and the diagnosis of liver metastasis should be based on pathological results.

20.
Int J Technol Assess Health Care ; 32(4): 212-217, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27766992

RESUMO

OBJECTIVES: Curative hepatectomy and tumor thrombectomy for hepatocellular carcinoma with complicating biliary tumor thrombosis (HCC/BTT) is associated with high surgical morbidity and mortality. This retrospective study evaluated the effectiveness and safety of neoadjuvant transcatheter arterial chemoembolization (TACE) in HCC/BTT patients scheduled for curative resection. METHODS: Thirty consecutive patients with diagnosed HCC/BTT were hospitalized for neoadjuvant TACE and elective curative liver resection (group A; n=20) or curative liver resection alone (group B; n=10). The primary outcome measure was median survival. RESULTS: Group A had a significantly shorter overall operative time (160±25 versus 190±35 min; p < .01) and duration of inflow control (14.3±3.6 versus 25.1±5.1 min; p < .01) and significantly less intraoperative blood loss (150±35 versus 520±75 ml; p < .01) and transfusion (100±40 versus 375±55 ml; p < .01) as compared to group B. Among patients undergoing both thrombectomy and curative resection, the median survival of group A was significantly longer than that of group B (28.5 [9-54] versus 21.5 [6-39] months; p < .01); among those who received thrombectomy alone, the median survival of group A was also significantly longer than that of group B (12.8 [6-25] versus 4.5 [2-7] months; p < .01). CONCLUSIONS: Neoadjuvant TACE significantly reduced the surgical risk of curative liver resection and significantly prolonged median survival in HCC patients with complicating BTT.


Assuntos
Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/métodos , Hepatectomia/métodos , Neoplasias Hepáticas/terapia , Terapia Neoadjuvante/métodos , Trombectomia/métodos , Perda Sanguínea Cirúrgica , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/cirurgia , Feminino , Humanos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Estudos Retrospectivos
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