43 research outputs found

    Fluorescent Self-Assembled Polyphenylene Dendrimer Nanofibers

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    A second-generation polyphenylene dendrimer 1 self-assembles into nanofibers on various substrates such as HOPG, silicon, glass, and mica from different solvents. The investigation with noncontact atomic force microscopy (NCAFM) and scanning electron microscopy (SEM) shows that the morphology of the dendrimer nanofibers highly depends on substrate, solvent, and preparation method. Fluorescent nanofibers can be prepared from a polyphenylene dendrimer with chromophores either attached to the periphery of the dendrimer or incorporated in its core. Fluorescent nanofibers formed from polyphenylene dendrimer 4 with a perylenediimide core show isolated-chromophore emission due to the shielding of the rigid polyphenylene dendrons. Dendrimer 2 with one perylenemonoimide attached to its periphery self-assembles into fluorescent nanofibers, which exhibit a dimer like emission as a result of the interactions between peripheral chromophores. Dendrimer 3 with two perylenemonoimides at the rim does not form nanofibers by itself, but mixing of nonfluorescent dendrimer 1 with fluorescent dendrimers 2 or 3 leads to the formation of nanofibers with a homogeneous composition. Therefore, mixing can not only coassemble nonnanofiber-forming dendrimer 3 into nanofibers but also give rise to isolated-chromophore emission upon proper dilution

    Efficacy of baricitinib in patients with moderate-to-severe rheumatoid arthritis up to 6.5 years of treatment: results of a long-term study

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    Objectives: To evaluate the long-term efficacy of once-daily baricitinib 4 mg or 2 mg in patients with active rheumatoid arthritis who had inadequate response (IR) to MTX, csDMARDs or bDMARDs. Methods: Data from three completed phase III studies—RA-BEAM (MTX-IR), RA-BUILD (csDMARD-IR) and RA-BEACON (bDMARD-IR)—and one completed long-term extension study (RA-BEYOND) were analysed up to 6.5 years [340 weeks (RA-BEAM) and 336 weeks (RA-BUILD and RA-BEACON)]. Low disease activity (LDA) [Simplified Disease Activity Index (SDAI) ≤11], clinical remission (SDAI ≤3.3) and physical function [Health Assessment Questionnaire Disability Index (HAQ-DI) ≤0.5] were the main outcomes assessed. Completer and non-responder imputation (NRI) analyses were conducted on each population. Results: At week 340 or 336, LDA was achieved in 37%/83% of MTX-IR, 35%/83% of csDMARD-IR and 23%/73% of bDMARD-IR patients treated with baricitinib 4 mg, assessed by NRI/completer analyses, respectively. Remission was achieved in 20%/40% of MTX-IR, 13%/32% of csDMARD-IR and 9%/30% of bDMARD-IR patients treated with baricitinib 4 mg, assessed by NRI/completer analyses, respectively. HAQ-DI ≤0.5 was reached in 31%/51% of MTX-IR, 25%/46% of csDMARD-IR and 24%/38% of bDMARD-IR patients treated with baricitinib 4 mg, assessed by NRI/completer analyses, respectively. Conclusion: Treatment with baricitinib 4 mg or 2 mg demonstrated efficacy up to 6.5 years with maintained LDA/remission results across SDAI, CDAI and DAS28-hsCRP consistent with previously reported data, and was well tolerated. Trial registration: United States National Library of Medicine clinical trials database www.clinicaltrials.gov; RA-BEYOND; NCT01885078

    Fluorescence and Intramolecular Energy Transfer in Polyphenylene Dendrimers

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    The fluorescence of polyphenylene dendrimers and the intramolecular energy transfer in polyphenylene dendrimers containing a perylenediimide core have been investigated in this paper. Polyphenylene dendrimers composed of tens or hundreds of out-of-plane twisted phenyl units exhibit strong fluorescence, with quantum yields ranging from 0.2 to 0.5 depending on the dendrimer generation and its degree of functionality. The fluorescence of polyphenylene dendrimers can be efficiently quenched by the incorporated perylenediimide core, and consequently, a predominant emission from the core has been observed, indicating a very efficient intramolecular energy transfer

    Genome-Wide Identification of Polycomb Target Genes Reveals a Functional Association of Pho with Scm in Bombyx mori

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    Polycomb group (PcG) proteins are evolutionarily conserved chromatin modifiers and act together in three multimeric complexes, Polycomb repressive complex 1 (PRC1), Polycomb repressive complex 2 (PRC2), and Pleiohomeotic repressive complex (PhoRC), to repress transcription of the target genes. Here, we identified Polycomb target genes in Bombyx mori with holocentric centromere using genome-wide expression screening based on the knockdown of BmSCE, BmESC, BmPHO, or BmSCM gene, which represent the distinct complexes. As a result, the expressions of 29 genes were up-regulated after knocking down 4 PcG genes. Particularly, there is a significant overlap between targets of BmPho (331 out of 524) and BmScm (331 out of 532), and among these, 190 genes function as regulator factors playing important roles in development. We also found that BmPho, as well as BmScm, can interact with other Polycomb components examined in this study. Further detailed analysis revealed that the C-terminus of BmPho containing zinc finger domain is involved in the interaction between BmPho and BmScm. Moreover, the zinc finger domain in BmPho contributes to its inhibitory function and ectopic overexpression of BmScm is able to promote transcriptional repression by Gal4-Pho fusions including BmScm-interacting domain. Loss of BmPho expression causes relocalization of BmScm into the cytoplasm. Collectively, we provide evidence of a functional link between BmPho and BmScm, and propose two Polycomb-related repression mechanisms requiring only BmPho associated with BmScm or a whole set of PcG complexes

    Generation, Annotation and Analysis of First Large-Scale Expressed Sequence Tags from Developing Fiber of Gossypium barbadense L

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    BACKGROUND: Cotton fiber is the world's leading natural fiber used in the manufacture of textiles. Gossypium is also the model plant in the study of polyploidization, evolution, cell elongation, cell wall development, and cellulose biosynthesis. G. barbadense L. is an ideal candidate for providing new genetic variations useful to improve fiber quality for its superior properties. However, little is known about fiber development mechanisms of G. barbadense and only a few molecular resources are available in GenBank. METHODOLOGY AND PRINCIPAL FINDINGS: In total, 10,979 high-quality expressed sequence tags (ESTs) were generated from a normalized fiber cDNA library of G. barbadense. The ESTs were clustered and assembled into 5852 unigenes, consisting of 1492 contigs and 4360 singletons. The blastx result showed 2165 unigenes with significant similarity to known genes and 2687 unigenes with significant similarity to genes of predicted proteins. Functional classification revealed that unigenes were abundant in the functions of binding, catalytic activity, and metabolic pathways of carbohydrate, amino acid, energy, and lipids. The function motif/domain-related cytoskeleton and redox homeostasis were enriched. Among the 5852 unigenes, 282 and 736 unigenes were identified as potential cell wall biosynthesis and transcription factors, respectively. Furthermore, the relationships among cotton species or between cotton and other model plant systems were analyzed. Some putative species-specific unigenes of G. barbadense were highlighted. CONCLUSIONS/SIGNIFICANCE: The ESTs generated in this study are from the first large-scale EST project for G. barbadense and significantly enhance the number of G. barbadense ESTs in public databases. This knowledge will contribute to cotton improvements by studying fiber development mechanisms of G. barbadense, establishing a breeding program using marker-assisted selection, and discovering candidate genes related to important agronomic traits of cotton through oligonucleotide array. Our work will also provide important resources for comparative genomics, polyploidization, and genome evolution among Gossypium species
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