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The palladium-catalyzed highly regioselective asymmetric allylic alkylation of 3'-indolyl-3-oxindole derivatives with Morita-Baylis-Hillman (MBH) carbonates was developed to facilely construct chiral 3,3'-bisindole derivatives under mild reaction conditions. The regioselectivity (α/γ) of MBH carbonates was efficiently switched in the presence of chiral oxalamide phosphine or spiroketal-based diphosphine/Pd(0) complexes as a chiral catalyst. A series of multifunctional 3,3'-bisindole derivatives with all-carbon quaternary stereogenic centers were obtained in high yields with good to excellent enantio-, diastereo-, and regioselectivity. The present process is endowed with some salient features such as broad substrate scope, N-protecting group-free, excellent stereoselectivity, as well as adjustable regioselectivity.
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A palladium-catalyzed regioselective and asymmetric allylic alkylation of azlactones with MBH carbonates has been developed with chiral oxalamide-phosphine ligands. The corresponding reaction afforded a range of optically active γ-arylidenyl glutamic acid derivatives bearing an α-chiral quaternary stereocenter in good yields with excellent linear regio- and high enantioselectivity. This protocol furnishes an alternative approach for the construction of enantio-enriched unnatural α-amino acid derivatives.
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We reported a chiral oxamide-phosphine ligand (COAP-Ph)-Pd-catalyzed asymmetric [3+2] cycloaddition reaction between vinyl cyclopropane compounds derived from 1,3-indanedione and 2-vinylcyclopropane-1,1-dicarboxylates with cyclic sulfonyl 1-azadienes. The corresponding reactions provided a series of enantiomerically active spiro cyclopentane-indandione and cyclopentane structures bearing three consecutive stereogenic centers in good yields with good diastereo- and enantioselectivity. The COAP-Pd complex serves not only to promote generation of chiral π-allyl-palladium intermediates and induce the asymmetry of the reaction, but also depress the background reaction.
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Petroleum hydrocarbon contamination is of environmental and public health concerns due to its toxic components. Bioremediation utilizes microbial organisms to metabolism and remove these contaminants. The aim of this study was to enrich a microbial community and examine its potential to degrade petroleum hydrocarbon. Through successive enrichment, we obtained a bacterial consortium using crude oil as sole carbon source. The 16 S rRNA gene analysis illustrated the structural characteristics of this community. Metagenomic analysis revealed the specific microbial organisms involved in the degradation of cyclohexane and all the six BTEX components, with a demonstration of the versatile metabolic pathways involved in these reactions. Results showed that our consortium contained the full range of CDSs that could potentially degrade cyclohexane, benzene, toluene, and (o-, m-, p-) xylene completely. Interestingly, a single taxon that possessed all the genes involved in either the activation or the central intermediates degrading pathway was not detected, except for the Novosphingobium which contained all the genes involved in the upper degradation pathway of benzene, indicating the synergistic interactions between different bacterial genera during the hydrocarbon degradation.
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The genus Ciliochorella is a group of pestalotioid fungi, which typically occurs in subtropical and tropical areas. Species from the Ciliochorella genus play important roles in the decomposition of litter. In this study, we introduce two new species (Ciliochorellachinensissp. nov. and C.savannicasp. nov.) that were found on leaf litter collected from savanna-like vegetation in hot dry valleys of southwestern China. Phylogenetic analyses of combined LSU, ITS and tub2 sequence datasets indicated that C.chinensis and C.savannica respectively form a distinct clade within the Ciliochorella genus. The comparison of the morphological characteristics indicated that the two new species are well differentiated within this genus species. Analysis of the evolutionary history suggests that Ciliochorella originated from the Eurasian continent during the Paleogene (38 Mya). Further, we find that both new species can produce cellulase and laccase, playing a decomposer role.
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The members of Phyllachora are biotrophic, obligate plant parasitic fungi featuring a high degree of host specificity. This genus also features a high degree of species richness and worldwide distribution. In this study, four species occurring on leaf and stem of two different species of grass were collected from Shanxi and Shaanxi Provinces, China. Based on morphological analysis, multigene (combined data set of LSU, SSU, and ITS) phylogenetic analyses (maximum likelihood and Bayesian analysis), and host relationship, we introduce herein four new taxa of Phyllachora. Ancestral area reconstruction analysis showed that the ancestral area of Phyllachora occurred in Latin America about 194 Mya. Novel taxa are compared with the related Phyllachora species. Detailed descriptions, illustrations, and notes are provided for each species.
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In this work, nitrogen doped carbon dots (NCDs) were synthesized through one step hydrothermal reaction using citric acid and ethylenediamine as precursors. The prepared NCDs exhibit high quantum yield of 67.4%, good stability, excellent selectivity and sensitivity. It was found that the NCDs have potential as a fluorescence sensor for the detection of Hg2+. Under optimal conditions, good linearity between the change in NCDs fluorescence intensity and Hg2+ concentration was obtained in the range of 0.3 to 2.0 µM with a detection limit at 0.24 µM. The possible detection mechanism was static quenching of NCDs by Hg2+. The established method was successfully applied to the determination of Hg2+ in beverage samples. The results indicated that the NCDs-based sensor has potential for detection of Hg2+ in real beverage sample.
Assuntos
Mercúrio , Pontos Quânticos , Bebidas , Carbono , Corantes Fluorescentes , Limite de Detecção , Mercúrio/análise , Nitrogênio , Espectrometria de FluorescênciaRESUMO
OBJECTIVE: To explore the proliferation inhibition effects of Gecko alcohol extract (GAE) on human esophageal squamous carcinoma cell line EC-109 and its mechanism. METHODS: The inhibitory effects of GAE on proliferation of EC-109 cells were measured by MTT. Nucleolus change of apoptotic cells was observed by Hoechest33342 fluorescence staining. Apoptosis rate of EC-109 cells was detected by flow cytometry. The expressions of apoptosis protein Caspase-3 and FAS in EC-109 cells were investigated by immunohistochemistry. RESULTS: GAE had the inhibition effects on the proliferation of esophageal carcinoma cell EC-109. The apoptosis rate of EC-109 cell treated with GAE(3.0 mg/mL, 4.0 mg/mL) for 48h was 20.63% and 39.73%, respectively. Compared with control group,the expression of Fas and Caspase-3 was significantly up-regulated in GAE treated group. CONCLUSION: GAE can inhibit the proliferation of esophageal carcinoma EC-109 cells and induce them apoptosis which may be correlated with increasing expression of protein Fas and Caspase-3.
Assuntos
Antineoplásicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Lagartos , Materia Medica/farmacologia , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Carcinoma de Células Escamosas/patologia , Caspase 3/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Neoplasias Esofágicas/patologia , Etanol/química , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Materia Medica/administração & dosagem , Materia Medica/química , Regulação para Cima , Receptor fas/metabolismoRESUMO
Objective: To investigate the effects of calcium-sensing receptor (CaSR) on the c-Jun N-terminal kinase (JNK) in myocardial injury induced by endotoxin. Methods: The endotoxic model of neonatal rats was made by intraperitoneal injection of LPS(5 mg/kg). Neonatal Wistar rats were randomly divided into 6 groups: â control group (saline group), â¡endotoxin (LPS) group, â¢LPS + CaSR agonist group, â£LPS + CaSR inhibitor group, â¤LPS + JNK inhibitor group, â¥LPS + CaSR inhibitor + JNK inhibitor group. The morphology of myocardium was observed by HE staining. The content of lactate dehydrogenase(LDH) in serum was determined. And the expression of IL-6 mRNA was detected by PCR. The protein expressions of CaSR and JNK were analyzed by Western blot. Results: Compared with the control group, the myocardial injury was aggravated in the LPS group. The content of LDH and the expressions of IL-6 mRNA, CaSR and JNK were increased significantly (Pï¼0.05). Compared with the LPS group,myocardial injury was aggravated in the CaSR agonist group. The content of LDH and the expressions of IL-6 mRNA,CaSR and JNK were increased (Pï¼0.05). In the CaSR inhibitor group,myocardial injury was reduced. The content of LDH and the expressions of CaSR and JNK were decreased (Pï¼0.05). In the JNK inhibitor group,myocardial injury was further alleviated. The content of LDH and the expressions of IL-6 mRNA, CaSR and JNK were decreased (Pï¼0.05). Myocardial injury was significantly reduced in the CaSR inhibitor + JNK inhibitor group. The content of LDH and the expressions of IL-6 mRNA, CaSR and JNK were further reduced (Pï¼0.05). Conclusion: CaSR is involved in myocardial injury induced by LPS in neonatal rats perhaps through the JNK pathway.
Assuntos
Endotoxinas/toxicidade , Sistema de Sinalização das MAP Quinases , Miocárdio/patologia , Receptores de Detecção de Cálcio , Animais , Apoptose , Coração/efeitos dos fármacos , Ratos , Ratos Wistar , Receptores de Detecção de Cálcio/metabolismoRESUMO
BACKGROUND: To evaluate the dosimetric parameters of different bone marrow sparing strategies and radiotherapy technologies and determine the optimal strategy to reduce hematologic toxicity associated with concurrent chemoradiation (cCRT) for cervical cancer. METHODS: A total of 15 patients with Federation International of Gynecology and Obsterics (FIGO) Stage IIB cervical cancer treated with cCRT were re-planned for bone marrow (BM)-sparing plans. First, we determined the optimal BM sparing strategy for intensity modulated radiotherapy (IMRT), including a BMS-IMRT plan that used total BM sparing (IMRT-BM) as the dose-volume constraint, and another plan used os coxae (OC) and lumbosacral spine (LS) sparing (IMRT-LS+OC) to compare the plan without BM-sparing (IMRT-N). Then, we determined the optimal technology for the BMS-IMRT, including fixed-field IMRT (FF-IMRT), volumetric-modulated arc therapy (VMAT), and helical tomotherapy (HT). The conformity and homogeneity of PTV, exposure volume of OARs, and efficiency of radiation delivery were analyzed. RESULTS: Compared with the IMRT-N group, the average volume of BM that received ≥10, ≥20, ≥30, and ≥40 Gy decreased significantly in both two BM-sparing groups, especially in the IMRT-LS+OC group, meanwhile, two BMS-IMRT plans exhibited the similar effect on PTV coverage and other organs at risk (OARs) sparing. Among three common IMRT techniques in clinic, HT was significantly less effective than VMAT and FF-IMRT in the aspect of BM-Sparing. Additionally, VMAT exhibited more efficient radiation delivery. CONCLUSION: We recommend the use of VMAT with OC and LS as separate dose-volume constraints in cervical cancer patients aiming at reducing hematologic toxicity associated with cCRT, especially in developing countries.
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PURPOSE: In this paper, the association between polymorphisms of IFN-γ +874T/A (rs2430561), IFN-γR1 -56 T/C (rs2234711), IFN-γR1 +95 C/T (rs7749390), and IFN-γR1 -611A/G (rs 1327474) and human papillomavirus (HPV) susceptibility was investigated in rural women from Luohe, Henan, China. PATIENTS AND METHODS: A total of 520 rural women were enrolled from Luohe, including 260 with HPV infection and mild dysplasia or less and 260 without HPV infection. Single-nucleotide polymorphisms (SNPs) of IFN-γ +874T/A, IFN-γR1 -56 T/C, IFN-γR1 +95 C/T and IFN-γR1 -611A/G were genotyped using TaqMan Pre-Designed SNP Genotyping Assays. Serum IFN-γ levels were measured using Human IFN-γ Quantikine ELISA Kit. Multivariate logistic regression analysis was performed to identify the SNPs associated with HPV susceptibility. Serum IFN-γ levels were compared between different genotypes. RESULTS: The polymorphism of IFN-γ +874T/A was associated with HPV susceptibility and +874A carriers had an increased risk. Moreover, the odds ratio was higher in +874 AA carriers than in +874 AT carriers (1.672 vs 2.874). Serum IFN-γ levels were highest in IFN-γ +874 TT carriers, intermediate in AT carriers, and lowest in AA carriers (2.86±1.14 vs 1.57±0.79 vs 0.41±0.22 pg/mL, all P<0.05). CONCLUSION: The polymorphism of IFN-γ +874T/A was associated with HPV susceptibility in rural women from Luohe, Henan, China, and +874A carriers had an increased risk. The possible mechanism was that +874A carriers had a low production of IFN-γ.