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911.
Filaggrin is expressed in the cornified layer of epidermis and known to be one of the antigenic targets in rheumatoid arthritis. Although the citrulline residue in filaggrin is thought to be an antigenic determinant recognized by autoantibodies, the diagnostic sensitivity of synthetic citrullinated peptide is variable. To investigate the implication of anti-filaggrin antibodies recognizing uncitrullinated filaggrin in rheumatoid arthritis, we assayed antibody titers using unmodified recombinant filaggrin in the sera from 73 patients with rheumatoid arthritis, 150 patients with other connective tissue diseases and 70 normal controls. We also performed the correlation analysis between antibody titers and the clinical variables in patients with rheumatoid arthritis. Titers of IgG anti-filaggrin antibodies were significantly higher in rheumatoid arthritis patients compared to normal controls (P=0.02), but not in patients with osteoarthritis, ankylosing spondylitis or systemic lupus erythematosus. IgG anti-filaggrin antibodies were more frequently found in patients with rheumatoid arthritis compared to normal controls (12.3% vs 1.4% respectively, P=0.04). An anti-filaggrin antibody titer was correlated with visual analogue scale of pain, tender joint count, Ritchie articular index or C-reactive protein, but not with anti-nuclear antibody or rheumatoid factor. These results suggest that anti-filaggrin antibody recognizes the uncitrullinated filaggrin as an antigen and its titer correlates with clinical parameters, explaining the variable sensitivity of anti-filaggrin antibody test.  相似文献   
912.
Two benzo[b]oxepine derivatives, edulisones A (1) and B (2), were isolated from the bark of Aglaia edulis, collected in Indonesia. The relative stereochemistry of 1 was determined by single-crystal X-ray diffraction analysis. Treatment of compounds 1 and 2 with lithium hydroxide produced the same hydrolysis products, 1a and 1b, as a result of cleavage of the pyrrolidine ring to an alkylated amide mixture in each case, which demonstrated that these substances are epimeric at their 2-aminopyrrolidine moiety.  相似文献   
913.
Recent achievements in speciation studies of trace elements in the biological and environmental sciences by nuclear analytical techniques, mainly molecular activation analysis, position-sensitive spectrometry with a variety of exciting sources, and synchronous radiation-based analytical techniques (although radioisotope or enriched stable isotope-based speciation techniques are also used), particularly in our laboratory, are outlined. In this paper the merits and drawbacks of the nuclear analytical techniques are discussed, as are reagent blanks, contamination, and artifacts.  相似文献   
914.
Bioassay-guided fractionation of the stems and fruits of Aglaia elliptica using human oral epidermoid carcinoma (KB) cells, led to the isolation of five cyclopenta[b]benzofurans, constituted by methyl rocaglate (1) and four novel compounds (2–5), along with three known dammarane triterpenoids. Compound 5 possesses an unusual formyl ester substituent at the C-1 position. The structures of the novel compounds were established on the basis of spectroscopic methods. Compounds 1–5 were found to be very potent cytotoxic substances when evaluated against a panel of human cancer cell lines.  相似文献   
915.
本文介绍了以焦炉气中自有的NH_3为碱源,在PDS(双核酞菁钴磺酸盐)的催化作用下,脱除煤气中H_2S、HCN的工艺模拟研究,提出了新的焦炉气净化工艺流程,称为A-PDS工艺。选择出了适宜的工艺条件,可将煤气中H_2S由5~7g/m ̄3脱至20mg/m ̄3以下,脱除率达99%以上;可将HCN由0.8~1.3g/m ̄3脱至20mg/m ̄3以下,脱除率达98%。  相似文献   
916.
Random forest (RF) methodology is a nonparametric methodology for prediction problems. A standard way to use RFs includes generating a global RF to predict all test cases of interest. In this article, we propose growing different RFs specific to different test cases, namely case-specific random forests (CSRFs). In contrast to the bagging procedure in the building of standard RFs, the CSRF algorithm takes weighted bootstrap resamples to create individual trees, where we assign large weights to the training cases in close proximity to the test case of interest a priori. Tuning methods are discussed to avoid overfitting issues. Both simulation and real data examples show that the weighted bootstrap resampling used in CSRF construction can improve predictions for specific cases. We also propose a new case-specific variable importance (CSVI) measure as a way to compare the relative predictor variable importance for predicting a particular case. It is possible that the idea of building a predictor case-specifically can be generalized in other areas.  相似文献   
917.
The development of catalyst-controlled methods for direct functionalization of two distinct C−H bonds represents an appealing approach for C−C formations in synthetic chemistry. Herein, we describe an organocatalytic approach for straightforward acylation of C(sp3)−H bonds employing readily available aldehyde as “acyl source” involving dehydrogenative coupling of aldehydes with ether, amine, or benzylic C(sp3)−H bonds. The developed method affords a broad range of ketones under mild conditions. Mechanistically, simple ortho-cyanoiodobenzene is essential in the oxidative radical N-heterocyclic carbene catalysis to give a ketyl radical and C(sp3) radical through a rarely explored intermolecular hydrogen atom transfer pathway, rendering the acylative C−C formations in high efficiency under a metal- and light-free catalytic conditions. Moreover, the prepared products show promising anti-bacterial activities that shall encourage further investigations on novel agrochemical development.  相似文献   
918.
The development of high-performance X-ray detectors requires scintillators with fast decay time, high light yield, stability, and X-ray absorption capacity, which are difficult to achieve in a single material. Here, we present the first example of a lanthanide chalcogenide of LaCsSiS4 : 1 % Ce3+ that simultaneously integrates multiple desirable properties for an ideal scintillator. LaCsSiS4 : 1 % Ce3+ demonstrates a remarkably low detection limit of 43.13 nGyair s−1 and a high photoluminescence quantum yield of 98.24 %, resulting in a high light yield of 50480±1441 photons/MeV. Notably, LaCsSiS4 : 1 % Ce3+ exhibits a fast decay time of only 29.35±0.16 ns, making it one of the fastest scintillators among all lanthanide-based inorganic scintillators. Furthermore, this material shows robust radiation and moisture resistance, endowing it with suitability for chemical processing under solution conditions. To demonstrate the X-ray imaging capacity of LaCsSiS4 : 1 % Ce3+, we fabricated a flexible X-ray detector that achieved a high spatial resolution of 8.2 lp mm−1. This work highlights the potential of lanthanide chalcogenide as a promising candidate for high-performance scintillators.  相似文献   
919.
The polynuclear metal clusters continually attract wide interest due to their intriguing structures and potential applications in various scientific fields. Here, four actinide clusters have been synthesized by the utilization of multifunctional ligand ferrocenecarboxylic acid (HFcc) and Th4+/U4+ ions by solvent evaporation or solvothermal synthesis strategies in different solvents. Therein, compounds 1 , 2 and 4 feature similar [An63-O)43-OH)4]12+ cores, which are further coordinated by 12 Fcc ligands and different solvent molecules. The U6Fe12 cluster of compound 4 is linked by four free HFcc molecules via multiple hydrogen bonding to form a supramolecular cluster [U63-O)43-OH)4(Fcc)12(H2O)4] ⋅ 4HFcc. The cluster core of compound 3 is a μ3-O2− bridged [U33-O)]10+ unit, which is further coordinated by 10 Fcc ligands via three kinds of coordination modes. It is worth noting that multifunctional Fcc ligand not only endows compound 1 a main redox wave at E1/2=0.720 V in CH2Cl2/DMF solution, but also enables it to exhibit aggregation-induced emission (AIE) property.  相似文献   
920.
Using a surface force balance, we have measured the normal and shear forces between mica surfaces across aqueous caesium salt solutions (CsNO(3) and CsCl) up to 100 mM concentrations. In contrast to all other alkali metal ions at these concentrations, we find no evidence of hydration repulsion between the mica surfaces on close approach: the surfaces appear to be largely neutralized by condensation of the Cs ions onto the charged lattice sites, and are attracted on approach into adhesive contact. The contact separation at adhesion indicates that the condensed Cs ions protrude by 0.3 +/- 0.2 nm from each surface, an observation supported both by the relatively weak adhesion energies between the surfaces, and the relatively weak frictional yield stress when they are made to slide past each other. These observations show directly that the hydration shells about the Cs(+) ions are removed as the ions condense into the charged surface lattice. This effect is attributed to the low energies-resulting from their large ionic radius-required for dehydration of these ions.  相似文献   
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