248 research outputs found

    A highly efficient coordination polymer for selective trapping and sensing of perrhenate/pertechnetate

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    This work was financially supported by the National Natural Science Foundation of China (21771139), Tianjin Natural Science Foundation (17JCYBJC22800), and the Program for Innovative Research Team in University of Tianjin (TD13-5074).A porous cationic Ag(I) coordination polymer, [Ag(1,2,4,5-p4b)](SbF6) (TJNU-302) with the ligand 1,2,4,5-p4b (1,2,4,5-tetra(pyridin-4-yl)benzene), is reported that shows high sorption capacity (211 mg g–1) and distribution coefficient Kd (5.8 × 105 mL g–1) as well as outstanding selectivity in 500 times excess of CO32– or PO43– anion for perrhenate removal. TJNU-302 can act as a crystalline turn-off sensor for perrhenate upon UV radiation. In this way, a test paper strip for sensing ReO4– could be produced. In water solution, TJNU-302 shows an efficient fluorescence quenching response to ReO4– ion, with the highest quenching percentage (86%) among all reported ReO4– sensors. These results could be elucidated by the bonding properties of single-crystal structures of TJNU-302 before and after perrhenate sorption, as well as density functional theory (DFT) calculations.PostprintPeer reviewe

    Distinct roles of NMB and GRP in itch transmission

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    A key question in our understanding of itch coding mechanisms is whether itch is relayed by dedicated molecular and neuronal pathways. Previous studies suggested that gastrin-releasing peptide (GRP) is an itch-specific neurotransmitter. Neuromedin B (NMB) is a mammalian member of the bombesin family of peptides closely related to GRP, but its role in itch is unclear. Here, we show that itch deficits in mice lacking NMB or GRP are non-redundant and Nmb/Grp double KO (DKO) mice displayed additive deficits. Furthermore, both Nmb/Grp and Nmbr/Grpr DKO mice responded normally to a wide array of noxious stimuli. Ablation of NMBR neurons partially attenuated peripherally induced itch without compromising nociceptive processing. Importantly, electrophysiological studies suggested that GRPR neurons receive glutamatergic input from NMBR neurons. Thus, we propose that NMB and GRP may transmit discrete itch information and NMBR neurons are an integral part of neural circuits for itch in the spinal cord

    The role of vimentin in regulating cell-invasive migration in dense cultures of breast carcinoma cells

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    Cell migration and mechanics are tightly regulated by the integrated activities of the various cytoskeletal networks. In cancer cells, cytoskeletal modulations have been implicated in the loss of tissue integrity, and acquisition of an invasive phenotype. In epithelial cancers, for example, increased expression of the cytoskeletal filament protein vimentin correlates with metastatic potential. Nonetheless, the exact mechanism whereby vimentin affects cell motility remains poorly understood. In this study, we measured the effects of vimentin expression on the mechano-elastic and migratory properties of the highly invasive breast carcinoma cell line MDA231. We demonstrate here that vimentin stiffens cells and enhances cell migration in dense cultures, but exerts little or no effect on the migration of sparsely plated cells. These results suggest that cell-cell interactions play a key role in regulating cell migration, and coordinating cell movement in dense cultures. Our findings pave the way towards understanding the relationship between cell migration and mechanics, in a biologically relevant context.Comment: 26+21 pages, 6+11 figures, supplementary movies available at http://doi.org/10.6084/m9.figshare.5480149, submitted to Nano Letters journa

    The Impact of Variational Primary Collaterals on Cerebral Autoregulation

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    The influence of the anterior and posterior communicating artery (ACoA and PCoA) on dynamic cerebral autoregulation (dCA) is largely unknown. In this study, we aimed to test whether substantial differences in collateral anatomy were associated with differences in dCA in two common types of stenosis according to digital subtraction angiography (DSA): either isolated basal artery and/or bilateral vertebral arteries severe stenosis/occlusion (group 1; group 1A: with bilateral PCoAs; and group 1B: without bilateral PCoAs), or isolated unilateral internal carotid artery severe stenosis/occlusion (group 2; group 2A: without ACoA and with PCoA; group 2B: with ACoA and without PCoAs; and group 2C: without both ACoA and PCoA). The dCA was calculated by transfer function analysis (a mathematical model), and was evaluated in middle cerebral artery (MCA) and/or posterior cerebral artery (PCA). Of a total of 231 non-acute phase ischemic stroke patients who received both dCA assessment and DSA in our lab between 2014 and 2017, 51 patients met inclusion criteria based on the presence or absence of ACoA or PCoA, including 21 patients in the group 1, and 30 patients in the group 2. There were no significant differences in gender, age, and mean blood pressure between group 1A and group 1B, and among group 2A, group 2B, and group 2C. In group 1, the PCA phase difference values (autoregulatory parameter) were significantly higher in the subgroup with patent PCoAs, compared to those without. In group 2, the MCA phase difference values were higher in the subgroup with patent ACoA, compared to those without. This pilot study found that the cross-flow of the ACoA/PCoA to the affected area compensates for compromised dCA in the affected area, which suggests an important role of the ACoA/PCoA in stabilizing cerebral blood flow

    The Effects of Natural Chinese Medicine Aconite Root, Dried Ginger Rhizome, and Coptis

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    The 4 properties of Chinese materia medica refer to cold, hot, warm, and cool. In the present study, the effects of the Coptis, the prepared aconite root, and dried ginger rhizome were compared with regard to the rectal and skin temperature changes of the related body surface acupuncture points (Dazhui, Zhiyang, Mingmen, Zhongwan, and Shenque). The investigation aimed to explore the thermal sensitive points, which can reflect the cold and hot properties of the Chinese herbs. This study showed that the prepared aconite root and dried ginger rhizome exhibited a warming effect on the body temperature, whereas the warming sensitive points were Zhongwan, Shenque, Dazhui, and Zhiyang. Coptis exhibited both a warming and a cooling effect on the body temperature, and the cooling sensitive point was Dazhui. The concomitant effect of these three Chinese herbs on the regulation of the body temperature was reflected by Dazhui. However, there are still some limitations and one-sidedness. For instance, the cold and hot property of some herbs cannot be fully reflected through relevant acupoints on the conception and governor vessels. More detecting sites such as ears and internal organs will be selected for further exploration of Chinese herbs’ cold and hot property

    Chiral and kryptoracemic Dy(III) complexes with field-induced single molecule magnet behavior

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    Two mononuclear Dy(III) compounds formulated as [Dy(PNO)6(H2O)2]Br3 (1) and [Dy(PNO)6(NO3)](ClO4)2 (2) have been synthesized and characterized. Single crystal X-ray diffraction studies show that chiral and kryptoracemic strcuctures are formed when different anions are introduced into the system. 1 crystallizes in the non-polar orthorhombic space group P212121, whereas 2 assembles as a kryptoracemate in the polar monoclinic space group P21. The optical activity of single crystals of these two compounds was confirmed by circular dichroism (CD) studies. Thermal gravimetric analyses (TGA) revealed that they are stable up to 376 K (1) and 428 K (2). Differential scanning calorimetry (DSC) measurements demonstrate the absence of structural phase transitions over the investigated temperature range. Magnetic studies show that both compounds are field-induced single molecule magnets (SMMs) with energy barriers of 36 (± 0.8) K for 1 and 32 (± 1.4) K for 2. Furthermore, the dielectric and ferroelectric properties of compound 2 were also investigated

    Transcriptome Analysis of the Brown Planthopper Nilaparvata lugens

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    BACKGROUND: The brown planthopper (BPH) Nilaparvata lugens (StĂĄl) is one of the most serious insect pests of rice in Asia. However, little is known about the mechanisms responsible for the development, wing dimorphism and sex difference in this species. Genomic information for BPH is currently unavailable, and, therefore, transcriptome and expression profiling data for this species are needed as an important resource to better understand the biological mechanisms of BPH. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we performed de novo transcriptome assembly and gene expression analysis using short-read sequencing technology (Illumina) combined with a tag-based digital gene expression (DGE) system. The transcriptome analysis assembles the gene information for different developmental stages, sexes and wing forms of BPH. In addition, we constructed six DGE libraries: eggs, second instar nymphs, fifth instar nymphs, brachypterous female adults, macropterous female adults and macropterous male adults. Illumina sequencing revealed 85,526 unigenes, including 13,102 clusters and 72,424 singletons. Transcriptome sequences larger than 350 bp were subjected to Gene Orthology (GO) and KEGG Orthology (KO) annotations. To analyze the DGE profiling, we mainly compared the gene expression variations between eggs and second instar nymphs; second and fifth instar nymphs; fifth instar nymphs and three types of adults; brachypterous and macropterous female adults as well as macropterous female and male adults. Thousands of genes showed significantly different expression levels based on the various comparisons. And we randomly selected some genes to confirm their altered expression levels by quantitative real-time PCR (qRT-PCR). CONCLUSIONS/SIGNIFICANCE: The obtained BPH transcriptome and DGE profiling data provide comprehensive gene expression information at the transcriptional level that could facilitate our understanding of the molecular mechanisms from various physiological aspects including development, wing dimorphism and sex difference in BPH
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