The construction of carbon–heteroatom bonds is one of the most active areas of research in organic chemistry because the function of organic molecules is often derived from the presence of ...heteroatoms. Although considerable advances have recently been achieved in radical-involved catalytic asymmetric C–N bond formation, there has been little progress in the corresponding C–O bond-forming processes. Here, we describe a photoinduced copper-catalyzed cross-coupling of readily available oxime esters and 1,3-dienes to generate diversely substituted allylic esters with high regio- and enantioselectivity (>75 examples; up to 95% ee). The reaction proceeds at room temperature under excitation by purple light-emitting diodes (LEDs) and features the use of a single, earth-abundant copper-based chiral catalyst as both the photoredox catalyst for radical generation and the source of asymmetric induction in C–O coupling. Combined experimental and density functional theory (DFT) computational studies suggest the formation of π-allylcopper complexes from redox-active oxime esters as bifunctional reagents and 1,3-dienes through a radical–polar crossover process.
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IJS, KILJ, NUK, PNG, UL, UM
Naturally fermented pickles harbour many lactic acid bacteria （LAB）. Forty-three LAB strains with conjugated linoleic acid （CLA）-producing ability were isolated from three naturally fermented pickle ...brines. Of these isolates, Ip15 identified as Lactobacillus plantarum by API 50 CHL system and full-length 16S rDNA sequence analysis exhibited the highest CLA-producing ability （26.1% conversion） at 48 h in de Man Rogosa Sharpe （MRS） broth in the presence of 100 IJg/ml of linoleic acid （LA）. Compared to other strains, L. plantarum strain Ip15 showed the highest tolerance upon increased levels of LA in the medium, i.e., up to 600 μg/ml. This strain converted about 25% of LA into CLA isomers predominantly cis-9, trans-11 CLA （9-CLA） and trans-lO, cis-12 CLA （10-CLA）, of which 75% was 9-CLA. Interestingly, though the conversion rate of LA into CLA by Ip15 remained stable between 100 to 600μg/ml LA levels in the medium, it dropped sharply at 1000 μg/ml. Taken together, the Ip15 strain displayed relatively high LA tolerance with higher conversion rate, which implies that this strain is a valuable candidate for enhancing the CLA content in food-sources like pickles.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Two oxetane-derived monomers, 3-（2-cyano-ethoxy）methyl- and 3-（methoxy-（triethylenoxy））methyl-3＇- methyloxetane （COX and MTOX）, were prepared from 3-hydroxymethyl-3＇-methyloxetane. Their homo- and ...copolymerization in solution were carried out by the cationic ring-opening polymerization with BF3 · Et2O and 1,4-butanediol as co-initiator. The molecular weight and molecular weight distribution were determined using GPC so as to reveal the competition and interchange between active chain end （ACE） and activated monomer （AM） mechanism in the process. The reactivity ratios of the two monomers were calculated according to Kelen-Tudos using ^1H-NMR analysis. The influence of functional side chains in the monomers on the copolymerization behaviors was discussed in virtue of the reactivity ratio data. When doped with lithium salt LiTFSI, the ion conductivity of the homopolymer of MTOX reached 10^-3.58 S/cm at 30℃ and 10^-2.73 S/cm at 80℃, respectively, showing its potential to be used as polymer electrolyte for lithium ion battery.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Cervical cancer is one of the most common gynecologic malignant tumors. Propofol has been proposed to play a role of antitumor in various cancers. However, the functions and mechanisms of Propofol in ...cervical cancer is still not clear.
In vitro, the different concentrations of propofol were co-incubated with cervical cancer cell lines, including Hela, Caski and C-33A cells respectively. The pcDNA-HOTAIR plasmid was transfected into cells after the treatment of 10 μg/ml propofol. The cell viability and apoptosis were detected by MTT assay and TUNEL method. In vivo, propofol was injected into mice of transplantation tumor with Caski cells or with pcDNA-HOTAIR treated Caski cells.
Propofol significantly decreased the cell viability and increased the cell apoptosis in Hela, Caski and C-33A cells, while HOTAIR overexpression promoted cell viability and inhibits cell apoptosis. mTOR/p70S6K protein expression levels were also markedly reduced by propofol but the effects were reversed with pcDNA-HOTAIR. In vivo, propofol inhibited the tumor size but had no inhibition effect in HOTAIR overexpression group.
Propofol inhibited tumor size, cell viability and promoted cell apoptosis via inhibiting mTOR/p70S6K pathway mediated by HOTAIR in cervical cancer.
•Propofol inhibited cell growth and increased cell apoptosis in cervical cancer.•Propofol reduced tumor size of cervical cancer in vivo.•HOTAIR overexpression promotes cervical carcinoma cell growth via mTOR regulation.•HOTAIR was involved in the effects of propofol on cervical cancer cell growth.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Aridity and heat are significant environmental stressors that affect sheep adaptation and adaptability, thus influencing immunity, growth, reproduction, production performance, and profitability. The ...aim of this study was to profile mRNA expression levels in the spleen of indigenous Kazakh sheep breed for comparative analysis with the exotic Suffolk breed. Spleen histomorphology was observed in indigenous Kazakh sheep and exotic Suffolk sheep raised in Xinjiang China. Transcriptome sequencing of spleen tissue from the two breeds were performed via Illumina high-throughput sequencing technology and validated by RT-qPCR. Blood cytokine and IgG levels differed between the two breeds and IgG and IL-1β were significantly higher in Kazakh sheep than in Suffolk sheep (p < 0.05), though spleen tissue morphology was the same. A total of 52.04 Gb clean reads were obtained and the clean reads were assembled into 67,271 unigenes using bioinformatics analysis. Profiling analysis of differential gene expression showed that 1158 differentially expressed genes were found when comparing Suffolk with Kazakh sheep, including 246 up-regulated genes and 912 down-regulated genes. Utilizing gene ontology annotation and pathway analysis, 21 immune- responsive genes were identified as spleen-specific genes associated with adaptive traits and were significantly enriched in hematopoietic cell lineage, natural killer cell-mediated cytotoxicity, complement and coagulation cascades, and in the intestinal immune network for IgA production. Four pathways and up-regulated genes associated with immune responses in indigenous sheep played indispensable and promoting roles in arid and hot environments. Overall, this study provides valuable transcriptome data on the immunological mechanisms related to adaptive traits in indigenous and exotic sheep and offers a foundation for research into adaptive evolution.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Herein, we investigate the product type and distribution during the synthesis of azido-functionalized larger polyhedral oligomeric silsesquioxanes (POSSs) using 3-chloropropyl- and ...chloromethyldimethylsilylethyl-functionalized T8, T10, and T12 POSSs as precursors. Our findings indicate that cage rearrangement occurs for the 3-chloropropyl-functionalized POSS cages with a stability order of T12 > T10 > T8, while the chloromethyldimethylsilylethyl-functionalized POSS cages remain structurally intact after the nucleophilic substitution.
Ischemic stroke is a common disease with poor prognosis, which has become one of the leading causes of morbidity and mortality worldwide. Astragaloside IV (AS-IV) is the main bioactive ingredient of ...Astragali Radix (which has been used for ischemic stroke for thousands of years) and has been found to have multiple bioactivities in the nervous system. In the present study, we aimed to explore the neuroprotective effects of AS-IV in rats with cerebral ischemia/reperfusion (CIR) injury targeting the Sirt1/Mapt pathway.
Sprague-Dawley rats (male, 250-280 g) were randomly divided into the Sham group, middle cerebral artery occlusion/reperfusion (MCAO/R) group, AS-IV group, MCAO/R + EX527 (SIRT1-specific inhibitor) group, and AS-IV + EX527 group. Each group was further assigned into several subgroups according to ischemic time (6 h, 1 d, 3 d, and 7 days). The CIR injury was induced in MCAO/R group, AS-IV group, MCAO/R + EX527 group, and AS-IV + EX527 group by MCAO surgery in accordance with the modified Zea Longa criteria. Modified Neurological Severity Scores (mNSS) were used to evaluate the neurological deficits; TTC (2,3,5-triphenyltetrazolium chloride) staining was used to detect cerebral infarction area; Western Blot was used to assess the protein levels of SIRT1, acetylated MAPT (ac-MAPT), phosphorylated MAPT (
-MAPT), and total MAPT (t-MAPT); Real-time Quantitative Polymerase Chain Reaction (qRT-PCR) was used in the detection of Sirt1 and Mapt transcriptions.
Compared with the MCAO/R group, AS-IV can significantly improve the neurological dysfunction (
< 0.05), reduce the infarction area (
< 0.05), raise the expression of SIRT1 (
< 0.05), and alleviate the abnormal hyperacetylation and hyperphosphorylation of MAPT (
< 0.05). While compared with the AS-IV group, AS-IV + EX527 group showed higher mNSS scores (
< 0.05), more severe cerebral infarction (
< 0.05), lower SIRT1 expression (
< 0.01), and higher ac-MAPT and
-MAPT levels (
< 0.05).
AS-IV can improve the neurological deficit after CIR injury in rats and reduce the cerebral infarction area, which exerts neuroprotective effects probably through the Sirt1/Mapt pathway.
Salicylic acid (SA) plays a crucial role in plant innate immunity. The deployment of SA-associated immune responses is primarily affected by SA concentration, which is determined by a balance between ...SA biosynthesis and catabolism. However, the mechanisms regulating SA homeostasis are poorly understood. In this study, we characterized a unique UDP-glycosyltransferase, UGT76D1, which plays an important role in SA homeostasis and associated immune responses in Arabidopsis (Arabidopsis thaliana). Expression of UGT76D1 was induced by treatment with both the pathogen Pseudomonas syringae pv. tomato (Pst) DC3000 and SA. Overexpression of UGT76D1 resulted in high SA accumulation, significant up-regulation of pathogen-related genes, and a hypersensitive response (HR)-like lesion mimic phenotype. This HR-like phenotype was not observed following UGT76D1 overexpression in SA-deficient NahG transgenic or sid2 plants, suggesting that the phenotype is SA dependent. Biochemical assays showed that UGT76D1 glycosylated 2,3-dihydroxybenzoic acid (2,3-DHBA) and 2,5-dihydroxybenzoic acid (2,5-DHBA), the major catabolic forms of SA, to their Glc and Xyl conjugates in vitro and in vivo. Moreover, in a mutant background blocked in the formation of 2,3-DHBA and 2,5-DHBA, UGT76D1 overexpression did not cause a HR-like lesion mimic phenotype. Following infection with Pst DC3000, UGT76D1 knockout mutants displayed a delayed immune response, with reduced levels of DHBA glycosides and SA, and down-regulated SA synthase expression. By contrast, UGT76D1 overexpression lines showed an enhanced immune response and increased SA biosynthesis before and after pathogen infection. Thus, we propose that UGT76D1 plays an important role in SA homeostasis and plant immune responses by facilitating glycosylation of dihydroxybenzoic acids.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
In this work, we report the design and application of a new ratiometric fluorescent probe, which contains different-colored quantum dots (QDs) as dual fluorophores, ultrathin silica shell as spacer, ...and meso-tetra(4-sulfonatophenyl)porphine dihydrochloride (TSPP) as receptor, for Zn(2+) detection in aqueous solution and living cells. In the architecture of our designed probe, the silica shell plays the key roles in controlling the locations of QDs, TSPP, and Zn(2+), preventing the direct contact between QDs and Zn(2+) but affording fluorescence resonance energy transfer (FRET) from dual-color QDs to TSPP. In the presence of Zn(2+), the analyte-receptor reaction changes the absorption in the range of the Q-band of TSPP and accordingly the efficiencies of two independent FRET processes from the dual-colored QDs to the acceptor, respectively, leading to fluorescence enhancement of green-emission QDs whereas fluorescence quenching of yellow-emission QDs. Benefiting from the well-resolved dual emissions from different-colored QDs and the large range of emission ratios, the probe solution displays continuous color changes from yellow to green, which can be clearly observed by the naked eye. Under physiological conditions, the probe exhibits a stable response for Zn(2+) from 0.3 to 6 μM, with a detection limit of 60 nM in aqueous solutions. With respect to single-emission probes, this ratiometric probe has demonstrated to feature excellent selectivity for Zn(2+) over other physiologically important cations such as Fe(3+) and Cu(2+). It has been preliminarily used for ratiometric imaging of Zn(2+) in living cells with satisfying resolution.
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IJS, KILJ, NUK, PNG, UL, UM
MicroRNAs （miRNAs） are endogenous -22 nt RNAs that play important regulatory roles in targeting mRNAs for cleavage or translational repression. Despite the discovery of increasing numbers of human ...and mouse miRNAs, little is known about miRNAs from pig. In this study, we sought to extend the repertoire of porcine small regulatory RNAs using Solexa sequencing. We sequenced a library of small RNAs prepared from immortalized swine umbilical vein endothelial cells （SUVECs）. We produced over 13.6 million short sequence reads, of which 8 547 658 perfectly mapped to the pig genome. A bioinformatics pipeline was used to identify authentic mature miRNA sequences. We identified 154 porcine miRNA genes, among which 146 were conserved across species, and 8 were pig-specific miRNA genes. The 146 miRNA genes encoded 116 conserved mature miRNAs and 66 miRNA^＊. The 8 pig-specific miRNA genes encoded 4 mature miRNAs. Four potential novel miRNAs were identified. The secondary structures of the 154 miRNA genes were predicted; 13 miRNAs have 2 structures, and miR-9 and miR-199 have 4 and 3 structures, respectively. 36 miRNAs were organized into 19 compact clusters, miR-206, miR-21 and miR-378 were the relatively highly expressed miRNAs. In conclusion, Solexa sequencing allowed the successful discovery of known and novel porcine miRNAs with high accuracy and efficiency. Furthermore, our results supply new data to the somewhat insufficient pig miRBase, and are useful for investigating features of the blood-brain barrier, vascular diseases and inflammation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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