67 research outputs found

    Modular Synthesis of Multifunctionalized CF<sub>3</sub>‑Allenes through Selective Activation of Saturated Hydrocarbons

    No full text
    Catalytic 1,4-dicarbofunctionalization of 1,3-enynes is a powerful strategy for the synthesis of polysubstituted allenes. Despite impressive progress, such a strategy is still restricted to the use of alkyl-metallic reagents or pre-activated radical precursors, thus limiting its functional group compatibility and atom economy. Herein, we report that through the combination of decatungstate photo-hydrogen atom transfer and nickel catalysis, a three-component 1,4-dicarbofunctionalization of 2-trifluoromethyl-1,3-enynes is achieved. This strategy allows the modular synthesis of tetrasubstituted CF3-allenes under exceptionally mild conditions. A variety of electrophiles such as aryl bromides, alkenyl bromides, acyl chlorides, and alkynyl bromides were successfully employed as traps to lead to the desired products. Another significant advantage is that the most abundant hydrocarbons are used as feedstocks, and a wide range of synthetically versatile functional groups and complex drug-like structures can be easily incorporated. Based on experimental and density functional theories, a possible catalytic cycle involving 1,3-nickel rearrangement is proposed

    Metal Ion-Regulated Fluorescent Sensor Array Based on Gold Nanoclusters for Physiological Phosphate Sensing

    No full text
    The detection of physiological phosphates (PPs) is of great importance due to their essential roles in numerous biological processes, but the efficient detection of different PPs simultaneously remains challenging. In this work, we propose a fluorescence sensor array for detecting PPs based on metal-ion-regulated gold nanoclusters (AuNCs) via an indicator-displacement assay. Zn2+ and Eu3+ are selected to assemble with two different AuNCs, resulting in quenching or enhancing their fluorescence. Based on the competitive interaction of metal ions with AuNCs and PPs, the fluorescence of AuNCs will be recovered owing to the disassembly of AuNC-metal ion ensembles. Depending on different PPs’ distinct fluorescence responses, a four-channel sensor array was established. The array not only exhibits good discrimination capability for eight kinds of PPs (i.e., ATP, ADP, AMP, GTP, CTP, UTP, PPi, and Pi) via linear discriminant analysis but also enables quantitative detection of single phosphate (e.g., ATP) in the presence of interfering PPs mixtures. Moreover, potential application of the present sensor array for the discrimination of different PPs in real samples (e.g., cell lysates and serum) was successfully demonstrated with a good performance. This work illustrates the great potential of a metal ion-regulated sensor array as a new and efficient sensing platform for differential sensing of phosphates as well as other disease-related biomolecules

    DataSheet1_An Improved Genetically Encoded Fluorescent cAMP Indicator for Sensitive cAMP Imaging and Fast Drug Screening.pdf

    No full text
    Cyclic adenosine 3′,5′-monophosphate (cAMP) is an important intracellular second messenger molecule downstream of many G protein-coupled receptors (GPCRs). Fluorescence imaging with bright and sensitive cAMP indicators allows not only dissecting the spatiotemporal dynamics of intracellular cAMP, but also high-content screening of compounds against GPCRs. We previously reported the high-performance circularly permuted GFP (cpGFP)-based cAMP indicator G-Flamp1. Here, we developed improved G-Flamp1 variants G-Flamp2 and G-Flamp2b. Compared to G-Flamp1, G-Flamp2 exhibited increased baseline fluorescence (1.6-fold) and larger fluorescence change (ΔF/F0) (1,300% vs. 1,100%) in HEK293T cells, while G-Flamp2b showed increased baseline fluorescence (3.1-fold) and smaller ΔF/F0 (400% vs. 1,100%). Furthermore, live cell imaging of mitochondrial matrix–targeted G-Flamp2 confirmed cytosolic cAMP was able to enter the mitochondrial matrix. G-Flamp2 imaging also showed that adipose tissue extract activated the Gi protein-coupled orphan GPCR GPR50 in HEK293T cells. Taken together, our results showed that the high-performance of G-Flamp2 would facilitate sensitive intracellular cAMP imaging and activity measurement of compounds targeting GPCR-cAMP signaling pathway during early drug development.</p

    Efficient Dehydrative Sialylation of C-4-Aminated Sialyl-Hemiketal Donors with Ph<sub>2</sub>SO/Tf<sub>2</sub>O

    No full text
    An efficient approach to the dehydrative sialylation of various substrates with C-4-aminated sialyl-hemiketal donors by using the reagent combination of diphenyl sulfoxide and triflic anhydride is reported. By using a C-4-hindered non-nucleophilic amine auxiliary, excellent yields and high α-stereoselectivities were obtained for coupling with a wide range of primary and secondary acceptors

    Efficient Dehydrative Sialylation of C-4-Aminated Sialyl-Hemiketal Donors with Ph<sub>2</sub>SO/Tf<sub>2</sub>O

    No full text
    An efficient approach to the dehydrative sialylation of various substrates with C-4-aminated sialyl-hemiketal donors by using the reagent combination of diphenyl sulfoxide and triflic anhydride is reported. By using a C-4-hindered non-nucleophilic amine auxiliary, excellent yields and high α-stereoselectivities were obtained for coupling with a wide range of primary and secondary acceptors

    Additional file 1: of Hedgehog pathway inhibition causes primary follicle atresia and decreases female germline stem cell proliferation capacity or stemness

    No full text
    A: microscopic observation of C-FGSCs (colony-like FGSCs) and B-FGSCs (beaded-like FGSCs), the scale is 20 μm; B: DNA agarose electrophoresis of multi-stemness molecular markers; C: ALP staining of FGSCs, scale is 20 μm; D: double IF of Mvh and Oct4, scale is 20 μm; E: double IF of Mvh and EdU, the scale is 20 μm. (DOCX 320 kb

    Gold Nanocluster-Based Fluorescent Microneedle Platform toward Visual Detection of ATP

    No full text
    Adenosine triphosphate (ATP) participates in the regulation of most biological processes, and the ATP level is closely associated with many diseases. However, it still remains challenging to achieve on-site monitoring of ATP in an equipment-free and efficient way. Microneedles, a minimally invasive technology that can extract biomarkers from liquid biopsies, have recently emerged as useful tools for early diagnosis of a broad range of diseases. In this work, we developed hydrogel microneedles that are loaded with ATP-specific dual-emitting gold nanoclusters (RhE-AuNCs) for fast sampling and on-needle detection of ATP. These RhE-AuNCs were photo-crosslinked to the hydrogel matrix to form a fluorescent microneedle patch. Based on the ATP-induced Förster resonance energy transfer in RhE-AuNCs, a highly selective, sensitive, and reliable ATP sensor was developed. Moreover, simultaneous capture and visual detection of ATP was achieved by the AuNC-loaded microneedle sensing platform, which exhibits promising sensing performance. This work provides a new approach to design a point-of-care ATP sensing platform, which also holds great potential for the further development of microneedle-based analytical devices

    Image_1_Comparative Efficacy, Safety, and Costs of Sorafenib vs. Sunitinib as First-Line Therapy for Metastatic Renal Cell Carcinoma: A Systematic Review and Meta-Analysis.TIF

    No full text
    Purpose: Sorafenib and sunitinib are extensively used as first-line medications for metastatic renal cell carcinoma (mRCC). This meta-analysis was conducted to assess the antitumor efficacy, toxicity, and costs of the two drugs among mRCC patients.Materials and methods: PubMed, ScienceDirect, Scopus, Web of Science, Ovid MEDLINE, the Cochrane Library, Embase, and Google Scholar were searched for eligible articles. The endpoints consisted of progression-free survival (PFS), overall survival (OS), objective response rate (ORR), adverse effects (AEs), and per-patient-per-month (PPPM) costs.Results: We included 14 studies with 2,925 patients. Both drugs were valid for treating mRCC with equivalent PFS [hazard ratio (HR) = 0.98, 95% confidence interval (CI): 0.88–1.10, P = 0.74] and disease control rates [DCRs; risk ratio (RR) = 1.03, 95% CI: 0.98–1.08, P = 0.28], but sunitinib had a better OS (HR = 1.10, 95% CI: 1.01–1.20, P = 0.04) and higher ORR (HR = 0.66, 95% CI: 0.45–0.97, P = 0.03) than sorafenib. Furthermore, sunitinib induced more incidences of severe hematologic AEs (anemia, neutropenia, and thrombocytopenia) and stomatitis/mucositis than sorafenib. In the subanalysis, Asian patients treated with sorafenib reported a longer PFS than those treated with sunitinib (HR = 0.87, 95% CI: 0.83–0.90, P = 0.01), and European patients treated with sunitinib had a longer OS than those treated with sorafenib (HR = 1.17, 95% CI: 1.01–1.30, P = 0.04). Moreover, the pooled results of the high-quality studies reported a higher ORR with sunitinib than with sorafenib, and medium-quality studies showed a longer OS with sunitinib than with sorafenib.Conclusions: Sunitinib has more benefits (longer OS and better ORR) than sorafenib as a first-line therapy for mRCC. However, sunitinib has higher toxicity than sorafenib. Sorafenib might be more suitable than sunitinib among Asian patients, and sunitinib might be superior to sorafenib in European patients. Nevertheless, more large-scale, high-quality studies are required.</p

    DataSheet1.XLSX

    No full text
    Bacterial regulatory RNAs have been extensively studied for over a decade, and are progressively being integrated into the complex genetic regulatory network. Transcriptomic arrays, recent deep-sequencing data and bioinformatics suggest that bacterial genomes produce hundreds of regulatory RNAs. However, while some have been authenticated, the existence of the others varies according to strains and growth conditions, and their detection fluctuates with the methodologies used for data acquisition and interpretation. For example, several small RNA (sRNA) candidates are now known to be parts of UTR transcripts. Accurate annotation of regulatory RNAs is a complex task essential for molecular and functional studies. We defined bona fide sRNAs as those that (i) likely act in trans and (ii) are not expressed from the opposite strand of a coding gene. Using published data and our own RNA-seq data, we reviewed hundreds of Staphylococcus aureus putative regulatory RNAs using the DETR'PROK computational pipeline and visual inspection of expression data, addressing the question of which transcriptional signals correspond to sRNAs. We conclude that the model strain HG003, a NCTC8325 derivative commonly used for S. aureus genetic regulation studies, has only about 50 bona fide sRNAs, indicating that these RNAs are less numerous than commonly stated. Among them, about half are associated to the S. aureus sp. core genome and a quarter are possibly expressed in other Staphylococci. We hypothesize on their features and regulation using bioinformatic approaches.</p

    Image_4_Comparative Efficacy, Safety, and Costs of Sorafenib vs. Sunitinib as First-Line Therapy for Metastatic Renal Cell Carcinoma: A Systematic Review and Meta-Analysis.TIF

    No full text
    Purpose: Sorafenib and sunitinib are extensively used as first-line medications for metastatic renal cell carcinoma (mRCC). This meta-analysis was conducted to assess the antitumor efficacy, toxicity, and costs of the two drugs among mRCC patients.Materials and methods: PubMed, ScienceDirect, Scopus, Web of Science, Ovid MEDLINE, the Cochrane Library, Embase, and Google Scholar were searched for eligible articles. The endpoints consisted of progression-free survival (PFS), overall survival (OS), objective response rate (ORR), adverse effects (AEs), and per-patient-per-month (PPPM) costs.Results: We included 14 studies with 2,925 patients. Both drugs were valid for treating mRCC with equivalent PFS [hazard ratio (HR) = 0.98, 95% confidence interval (CI): 0.88–1.10, P = 0.74] and disease control rates [DCRs; risk ratio (RR) = 1.03, 95% CI: 0.98–1.08, P = 0.28], but sunitinib had a better OS (HR = 1.10, 95% CI: 1.01–1.20, P = 0.04) and higher ORR (HR = 0.66, 95% CI: 0.45–0.97, P = 0.03) than sorafenib. Furthermore, sunitinib induced more incidences of severe hematologic AEs (anemia, neutropenia, and thrombocytopenia) and stomatitis/mucositis than sorafenib. In the subanalysis, Asian patients treated with sorafenib reported a longer PFS than those treated with sunitinib (HR = 0.87, 95% CI: 0.83–0.90, P = 0.01), and European patients treated with sunitinib had a longer OS than those treated with sorafenib (HR = 1.17, 95% CI: 1.01–1.30, P = 0.04). Moreover, the pooled results of the high-quality studies reported a higher ORR with sunitinib than with sorafenib, and medium-quality studies showed a longer OS with sunitinib than with sorafenib.Conclusions: Sunitinib has more benefits (longer OS and better ORR) than sorafenib as a first-line therapy for mRCC. However, sunitinib has higher toxicity than sorafenib. Sorafenib might be more suitable than sunitinib among Asian patients, and sunitinib might be superior to sorafenib in European patients. Nevertheless, more large-scale, high-quality studies are required.</p
    corecore