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