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Correction for 'Ionic-liquid supported rapid synthesis of an N-glycan core pentasaccharide on a 10 g scale' by Wei Li et al., Org. Biomol. Chem., 2018, 16, 4720-4727.
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A new and efficient Ionic Liquid-Supported Oligosaccharide Synthesis (ILSOS) strategy for an N-linked core pentasaccharide on a 10 g scale is reported. This new ILSOS includes a new spacer for an IL support, a new tagging strategy, and fast, efficient and orthogonal removal of the ionic-liquid support, producing the N-linked core pentasaccharide with direct applicability potential in a short time, with high yield and on a large gram scale.
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A hydrophobically assisted switching phase (HASP) method is an efficient strategy for the synthesis of carrier-loaded oligosaccharides. We improved this method by using cetyl thioglycoside as the carrier, which made it possible to use the synthetic oligosaccharide block directly as the donor. We applied this improved HASP method in the successful assembly of a gp120-associated nona-mannoside. Our results indicated that the HASP method is an efficient strategy for the synthesis of complex oligosaccharides and glycoconjugates.
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Oligossacarídeos/síntese química , Tioglicosídeos/química , Interações Hidrofóbicas e Hidrofílicas , Estrutura Molecular , Oligossacarídeos/químicaRESUMO
The hydrophobically assisted switching phase (HASP) method was applied in the assembly of oligomannosides. A new mannosyl donor with high reactivity was selected after a series of optimization studies, which was suitable for the synthesis of oligomannosides via the HASP method. The practicability of the HASP method towards the synthesis of branched oligosaccharides was explored and two branched penta-mannosides were assembled efficiently.
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Manosídeos/síntese química , Oligossacarídeos/síntese química , Técnicas de Química Sintética/métodos , Glicosilação , Interações Hidrofóbicas e Hidrofílicas , Manosídeos/química , Oligossacarídeos/químicaRESUMO
We report here the syntheses of mono- to tetravalent glycoclusters containing 1-methylene-C-ß-lactose. The 1-methylene-C-ß-lactose moiety has been synthesized from octa-acetyl-ß-lactose using the key carbonyl insertion reaction and linked to a series of alkynlated scaffolds via CuAAC reaction to afford mono- to tetravalent glycoclusters. The binding affinities of the final products to galectin-3 were found in the range of 10-100 µM.
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Galectina 3/metabolismo , Glicoconjugados/síntese química , Glicoconjugados/metabolismo , Lactose/química , Sítios de Ligação , Galectina 3/química , Glicoconjugados/química , Estrutura MolecularRESUMO
Oxazocines are key structural intermediates in the synthesis of natural products and pharmaceutical molecules. However, the synthesis of oxazocines especially in a highly enantioselective manner, is a long-standing formidable challenge due to unfavorable energetics involved in cyclization. Herein, a series of new PNP-Ligand P-chiral stereocenter is first designed and synthesized, called MQ-Phos, and successfully applied it in the Pd-catalyzed enantioselective higher-order formal [4+4]-cycloaddition of α, ß-unsaturated imines with 2-(hydroxymethyl)-1-arylallyl carbonates. The reaction features mild conditions, excellent regio- and enantiocontrol and a broad substrate scope (54 examples). Various medium-sized rings can be afforded in moderate to excellent yields (up to 92%) and excellent enantioselectivity (up to 99% ee). The newly developed MQ-Phos is critical for synthesis of the medium-sized ring in excellent catalytic reactivity and enantioselectivity.
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BACKGROUND: Thrombocytopenia 2, an autosomal dominant inherited disease characterized by moderate thrombocytopenia, predisposition to myeloid malignancies and normal platelet size and function, can be caused by 5'-untranslated region (UTR) point mutations in ankyrin repeat domain containing 26 (ANKRD26). Runt related transcription factor 1 (RUNX1) and friend leukemia integration 1 (FLI1) have been identified as negative regulators of ANKRD26. However, the positive regulators of ANKRD26 are still unknown. AIM: To prove the positive regulatory effect of GATA binding protein 2 (GATA2) on ANKRD26 transcription. METHODS: Human induced pluripotent stem cells derived from bone marrow (hiPSC-BM) and urothelium (hiPSC-U) were used to examine the ANKRD26 expression pattern in the early stage of differentiation. Then, transcriptome sequencing of these iPSCs and three public transcription factor (TF) databases (Cistrome DB, animal TFDB and ENCODE) were used to identify potential TF candidates for ANKRD26. Furthermore, overexpression and dual-luciferase reporter experiments were used to verify the regulatory effect of the candidate TFs on ANKRD26. Moreover, using the GENT2 platform, we analyzed the relationship between ANKRD26 expression and overall survival in cancer patients. RESULTS: In hiPSC-BMs and hiPSC-Us, we found that the transcription levels of ANKRD26 varied in the absence of RUNX1 and FLI1. We sequenced hiPSC-BM and hiPSC-U and identified 68 candidate TFs for ANKRD26. Together with three public TF databases, we found that GATA2 was the only candidate gene that could positively regulate ANKRD26. Using dual-luciferase reporter experiments, we showed that GATA2 directly binds to the 5'-UTR of ANKRD26 and promotes its transcription. There are two identified binding sites of GATA2 that are located 2 kb upstream of the TSS of ANKRD26. In addition, we discovered that high ANKRD26 expression is always related to a more favorable prognosis in breast and lung cancer patients. CONCLUSION: We first discovered that the transcription factor GATA2 plays a positive role in ANKRD26 transcription and identified its precise binding sites at the promoter region, and we revealed the importance of ANKRD26 in many tissue-derived cancers.
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A metal-free method for the direct regioselective fluorination of anilides has been developed. In the presence of bis(tert-butylcarbonyloxy)iodobenzene (PhI(OPiv)(2)) and hydrogen fluoride-pyridine, the para-fluorination products of anilides were obtained in moderate to good yields. Because of its operational safety and the use of readily available reagents, this new procedure provides facile access to a variety of para-fluorinated anilides.
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Anilidas/química , Ácido Fluorídrico/química , Iodo/química , Iodobenzenos/química , Piridinas/química , Halogenação , Estrutura MolecularRESUMO
Discus Symphysodon spp. employs an unusual parental care behavior where fry feed on parental skin mucus after hatching. Studies on discus immunoglobulin superfamily (IgSF) especially during parental care are scarce. Here, a total of 518 IgSF members were identified based on discus genome and clustered into 12 groups, unevenly distributing on 30 linkage groups. A total of 92 pairs of tandem duplication and 40 pairs of segmental duplication that underwent purifying selection were identified. IgSF genes expressed differentially in discus skin during different care stages and between male and female parents. Specifically, the transcription of btn1a1, similar with mammalian lactation, increased after spawning, reached a peak when fry started biting on parents' skin mucus, and then decreased. The expression of btn2a1 and other immune members, e.g., nect4, fcl5 and cd22, were up-regulated when fry stopped biting on mucus. These results suggest the expression differentiation of IgSF genes in skin of discus fish during parental care.
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Ciclídeos , Pele , Animais , Feminino , Masculino , Pele/metabolismo , Ciclídeos/genética , Vertebrados , Imunoglobulinas/metabolismo , Lactação , MamíferosRESUMO
We have developed a new KI-catalyzed method for the imidation of an sp(3) C-H bond adjacent to an amide nitrogen atom by using TBHP (tert-butyl hydroperoxide, 70% aqueous solution) as the oxidant. This novel procedure tolerated air and moisture and provided a series of novel products in moderate to excellent yields under mild conditions.
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Amidas/química , Imidas/síntese química , Iodeto de Potássio/química , Catálise , Imidas/química , Estrutura Molecular , EstereoisomerismoRESUMO
Detection of formaldehyde (FA) in the atmosphere is of significant importance because exposure to FA may cause serious health problems such as sick-house syndrome, leukemia, and cancer. Modifying metal oxide semiconductors (MOSs) with noble metal nanoparticles (NPs) is an efficient method to enhance FA-sensing properties. Herein, a series of Au25 nanocluster (NC)-decorated three-dimensionally ordered macroporous In2O3 materials (Au25/3DOM In2O3) is created, and the loading amount of Au25 NCs was optimized based on FA responses. To reveal the effect of gold size on FA responses, we constructed Au144 NC-loaded 3DOM In2O3 and Au NP (2.9 nm)-modified 3DOM In2O3 and compared their gas-sensing properties with the optimal Au25/3DOM In2O3. The results show that in comparison with its counterparts, the optimal Au25/3DOM In2O3 presents higher sensitivity, shorter response/recovery times, better selectivity, and excellent reproducibility. More attractively, the responses to FA are dependent on the size of Au particles loaded on In2O3. We suggest that the enhanced FA responses for the optimal material are mainly attributed to the electronic and chemical-sensitization effects of Au25 NCs, and the size-dependent effect of FA responses is ascribed to the size of Au NPs affecting the formation of oxygen-adsorbing species. This work provides an efficient way for fabricating noble metal NP-loaded MOSs with tunable gas-sensing properties.
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The plastisphere refers to biofilm formation on the microplastic (MP) surface, but its subsequent functions, especially driving the nitrogen biogeochemical cycle, are rarely studied. Here, MPs were incubated in the pelagic water and benthic water-sediment interface of an aquaculture pond, and the two corresponding microcosms amended with incubated plastisphere were simulated. The results showed decreased ammonia concentrations and increased nitrification rates in microcosms with either pelagic or benthic plastispheres. To uncover the possible mechanisms, the community structure and function of the plastisphere were investigated. As clarified by 16S rRNA, the community diversity of the pelagic plastisphere was significantly higher than that of the corresponding hydrosphere. Plastisphere communities, especially those incubated in pelagic water, were separated from the hydrosphere. Moreover, the abundance of Proteobacteria increased while the abundance of Cyanobacteria decreased in both plastispheres. Metagenome further revealed that the abundance of amoA and annotated Nitrososphaeraceae_archaeon and hao and affiliated Nitrosomonas_europaea, which contributed to ammonia oxidation to nitrite, was higher in the benthic plastisphere. Comparing the pelagic plastisphere with the corresponding hydrosphere, however, the abundance of nxrA and annotated Nitrobacter hamburgensis and nxrB and the affiliated Nitrospira moscoviensis, which are involved in nitrite oxidation, was more abundant in the plastisphere. These findings suggest that the plastisphere might selectively enrich functional microorganisms and genes in a habitat-dependent manner to promote nitrification in aquaculture ponds.
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Nitrificação , Plásticos , RNA Ribossômico 16S/genética , Amônia , Microplásticos , Nitritos , Lagoas , Filogenia , Aquicultura , Nitrogênio , Água , OxirreduçãoRESUMO
Metal oxide semiconductors (MOS) have been extensively studied for gas sensing due to their excellent chemical stability and adjustable electronic properties. However, there is still a lack of ingenious design strategies to achieve customizable gas detection in complex environments. Herein, a novel and scalable strategy of constructing organic-inorganic "chelate" adsorption sites is proposed to promote the affinity of MOS sensing materials to target molecules. Specifically, 3-aminopropyltriethoxysilane (APTES)-functionalized reduced graphene oxide (rGO) was decorated on In2O3 tubes (AG/Inx), and its NO2 sensing performance was studied. As a result, the optimal AG/Inx shows boosted room-temperature NO2 response, and its response to 1 ppm NO2 is 4.8 times that of In2O3. More attractively, the optimal AG/Inx exhibits good selectivity, as well as outstanding detection ability (Rg/Ra = 1.6) for low concentration NO2 (20 ppb). Experimental results suggest that APTES-rGO not only acts as the electron acceptor to accelerate charge transfer, but also enhances NO2 adsorption. Further theoretical calculations reveal that NO2 is simultaneously adsorbed at rGO and APTES via a flexible "chelate" mechanism. The multidentate adsorption configuration remarkably strengthens the NO2-host interaction, which is conducive to improving sensing performance. This work may inspire the material design of a new generation high-performance gas sensors.
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Background and Purpose: Neutrophil-lymphocyte ratio (NLR) predicts clinical outcomes in patients with stroke. Aneurysm wall enhancement (AWE) on high-resolution vessel wall magnetic resonance imaging (HR-VWI) is an inflammation marker for intracranial aneurysm (IA). This study aims to evaluate the association of NLR as a peripheral blood inflammatory marker with circumferential AWE in patients with IA. Methods: We analyzed data of consecutive patients harboring IAs between September 2017 and December 2021 at our institution. The peripheral blood inflammatory indicators were compared between patients with ruptured and unruptured IAs. The presence of circumferential AWE in unruptured IA was identified and quantitatively measured using the aneurysm-to-pituitary stalk contrast ratio (CRstalk) on HR-VWI. We used the optimal cutoff value of 0.5 for CRstalk to differentiate circumferential AWE in unruptured IAs. We assessed the relationship of clinical, laboratory, and radiological characteristics with circumferential AWE and CRstalk ≥0.5 in unruptured IAs. Results: The study group was composed of one hundred and twenty-five patients with 142 IAs. NLR level at admission was significantly higher in patients with ruptured IAs than those with unruptured IAs (7.55 vs. 1.81; P < 0.001). AWE on HR-VWI was present in 30 patients with unruptured IAs (38.5%), including 12 with focal AWE and 18 with circumferential AWE. NLR (odds ratio (OR), 2.168; 95% CI, 1.149-4.088) and size (odds ratio, 1.370; 95% CI, 1.126-1.667) were independently associated with circumferential AWE in unruptured IA. NLR was also independently associated with circumferential AWE in small unruptured IA (<7 mm). Furthermore, NLR level at admission was associated with CRstalk ≥.5 in patients with unruptured IA. The optimal cutoff value of NLR for circumferential AWE was 1.86. Conclusion: NLR is a valuable peripheral blood inflammatory marker is more often in the rupture status of IA and was associated with circumferential AWE on HR-VWI in unruptured IA.
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BACKGROUND: Aneurysm wall enhancement on high-resolution vessel wall imaging (HR-VWI) may represent vessel wall inflammation for unruptured intracranial aneurysms (UIAs). Further evidence for the role of circumferential aneurysm wall enhancement (CAWE) in evaluating the instability of UIAs is required, especially in small aneurysms (<7 mm). METHODS: We analyzed patients with saccular UIAs who prospectively underwent HR-VWI on a 3.0 T MRI scanner in our center from September 2017 to August 2021. The presence of AWE was identified and quantitatively measured using the aneurysm-to-pituitary stalk contrast ratio (CRstalk) with maximal signal intensity value. The PHASES and ELAPSS scores were used to assess the risk of aneurysm rupture and growth. We evaluated the association of CAWE and CRstalk value with intracranial aneurysm instability. RESULTS: One hundred patients with 109 saccular UIAs were included in this study. Eighty-three UIAs (76.1%) had a size smaller than 7 mm. PHASES and ELAPSS scores were significantly higher in UIAs with CAWE than in UIAs without CAWE (p < .01). The association of CAWE with PHASES and ELAPSS scores remained in small UIAs (<7 mm). The optimal cutoff value of CRstalk for CAWE was 0.5. PHASES and ELAPSS scores were significantly higher in UIAs with CRstalk ≥0.5 than in UIAs with CRstalk <0.5 (p < .01). CONCLUSIONS: CAWE on HR-VWI is a valuable imaging marker for aneurysm instability in UIAs. CRstalk value ≥0.5 may be associated with a higher risk of intracranial aneurysm rupture and growth.
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Aneurisma Roto , Aneurisma Intracraniano , Aneurisma Roto/diagnóstico por imagem , Humanos , Inflamação , Aneurisma Intracraniano/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodosRESUMO
An improved method for the synthesis of large and complex oligosaccharides on ionic liquid (IL) support was developed. A strategy to attach the acceptor on IL using a more stable ether linker was used to prevent undesirable decomposition and side products. A "dissolution-evaporation-precipitation" purification procedure was also developed by combining the advantages of precipitation and solid-liquid extraction to reduce mechanical loss and purification time. This approach was successfully used for the rapid assembly of ionic liquid supported homolinear α(1â2)-linked nonamannoside in 25.2% overall yield within 28.5 h.
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Líquidos Iônicos/química , Oligossacarídeos/síntese química , Glicosilação , Estrutura Molecular , Oligossacarídeos/químicaRESUMO
An improved method for the deprotection of benzyl ethers using a catalytic amount of Co(2)(CO)(8) in the presence of Me(2)PhSiH and CO (1 atm) is described. The deprotection reaction is compatible with double bond or sulfur-containing substrates. The method also tolerates other functional groups, such as Ac, Piv, and Bz, and shows potential selectivity in perbenzylated monosaccharides.
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Cobalto/química , Éteres Fenílicos/química , Catálise , Estrutura MolecularRESUMO
Macrophages are widely distributed in tissues and function in homeostasis. During cancer development, tumor-associated macrophages (TAMs) dominatingly support disease progression and resistance to therapy by promoting tumor proliferation, angiogenesis, metastasis, and immunosuppression, thereby making TAMs a target for tumor immunotherapy. Here, we started with evidence that TAMs are highly plastic and heterogeneous in phenotype and function in response to microenvironmental cues. We pointed out that efforts to tear off the heterogeneous "camouflage" in TAMs conduce to target de facto protumoral TAMs efficiently. In particular, several fate-mapping models suggest that most tissue-resident macrophages (TRMs) are generated from embryonic progenitors, and new paradigms uncover the ontogeny of TAMs. First, TAMs from embryonic modeling of TRMs and circulating monocytes have distinct transcriptional profiling and function, suggesting that the ontogeny of TAMs is responsible for the functional heterogeneity of TAMs, in addition to microenvironmental cues. Second, metabolic remodeling helps determine the mechanism of phenotypic and functional characteristics in TAMs, including metabolic bias from macrophages' ontogeny in macrophages' functional plasticity under physiological and pathological conditions. Both models aim at dissecting the ontogeny-related metabolic regulation in the phenotypic and functional heterogeneity in TAMs. We argue that gleaning from the single-cell transcriptomics on subclonal TAMs' origins may help understand the classification of TAMs' population in subclonal evolution and their distinct roles in tumor development. We envision that TAM-subclone-specific metabolic reprogramming may round-up with future cancer therapies.
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Embrião de Mamíferos/patologia , Neoplasias/patologia , Neoplasias/prevenção & controle , Macrófagos Associados a Tumor/patologia , Glucose/metabolismo , Humanos , Metabolismo dos Lipídeos , Neoplasias/metabolismo , Análise de Célula ÚnicaRESUMO
We have previously reported a facile and convenient method for the preparation of a new type of lactose-CdSeS/ZnS quantum dots conjugates (Lac-QDs) that exhibit biocompatibility, noncytotoxicity and specificity to leukocytes. In order to further study the carbohydrate-protein interactions, a series of Lac-QDs with different lactose densities and a PEGylated (n=3) lactose-QDs conjugate (LacPEG-QDs) with more flexible sugar ligands were prepared. The amount of the sugar molecules on QDs can be determined by NMR, which was in agreement with the results from TGA determination. The formula of the conjugates was determined with ICP-OES. The interactions between the conjugated QDs and the PNA protein were measured using SPR, which revealed that higher lactose density favored binding affinity under the same concentration, and Lac-QDs exhibit higher affinity than LacPEG-QDs. We further used a solid phase assay to assess the anti-adhesion activity of Lac-QDs and LacPEG-QDs on the cell level. The results showed that Lac-QDs had stronger activity in preventing THP1 from adhering to HUVEC than LacPEG-QDs, which was consistent with the SPR results. We reasoned that decrease in the conformational entropy induced by appropriate restriction of sugar flexibility could enhance the binding affinity of glyco-QDs, which implies that entropy change may be the main contributor to the interaction between high valent glyco-QDs and protein. The fabrication of lactose on QDs provides a fluorescent multivalent carbohydrate probe that can be used as mimics of glycoprotein for the study of carbohydrate-protein interactions and cell imaging.
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Metabolismo dos Carboidratos , Lactose/química , Leucócitos/citologia , Proteínas/metabolismo , Pontos Quânticos , Animais , Adesão Celular , Linhagem Celular , Sobrevivência Celular , Humanos , Camundongos , Microscopia de Fluorescência/métodosRESUMO
Solar-driven photocatalytic CO2 reduction into CH4 with H2O is considered to be a promising way to alleviate the energy crisis and greenhouse effect. However, current CO2 photoreduction technologies tend to overlook the role of photooxidation half reaction as well as the effect of the protons produced by water oxidation on CH4 generation, resulting in low CO2 conversion efficiency and poor CH4 selectivity. In the present study, a series of chloride-modified Bi2WO6 nanosheets were constructed in view of chloride-assisted photocatalytic water oxidation. The results show that the CH4 yield of the synthesized sample can be enhanced up to about 10 times compared to that with no Cl- modification. Besides, the selectivity of CH4 can be regulated by the loading amount of chloride, varying from 51.29% for Bi2WO6 to 94.98% for the maximum. The increase of product yield is attributed to chloride modification, which not only changed the morphology of the catalyst, but also modified the pathway of water oxidation. Further studies on intermediate products and the density functional theory calculation confirm that the Cl- ions on Bi2WO6 nanosheets not only promote H2O oxidation, but also lower the energy barrier for intermediate *CHO generation, thus facilitating CH4 production. The results gained herein may provide some illuminating insights into the design of a highly selective photocatalyst for efficient CO2 reduction.