29 research outputs found
MicroRNAs show diverse and dynamic expression patterns in multiple tissues of Bombyx mori
<p>Abstract</p> <p>Background</p> <p>MicroRNAs (miRNAs) repress target genes at the post-transcriptional level, and function in the development and cell-lineage pathways of host species. Tissue-specific expression of miRNAs is highly relevant to their physiological roles in the corresponding tissues. However, to date, few miRNAs have been spatially identified in the silkworm.</p> <p>Results</p> <p>We establish for the first time the spatial expression patterns of nearly 100 miRNAs in multiple normal tissues (organs) of <it>Bombyx mori </it>females and males using microarray and Northern-blotting analyses. In all, only 10 miRNAs were universally distributed (including bmo-let-7 and bmo-bantam), while the majority were expressed exclusively or preferentially in specific tissue types (e.g., bmo-miR-275 and bmo-miR-1). Additionally, we examined the developmental patterns of miRNA expression during metamorphosis of the body wall, silk glands, midgut and fat body. In total, 63 miRNAs displayed significant alterations in abundance in at least 1 tissue during the developmental transition from larvae to pupae (e.g., bmo-miR-263b and bmo-miR-124). Expression patterns of five miRNAs were significantly increased during metamorphosis in all four tissues (e.g., bmo-miR-275 and bmo-miR-305), and two miRNA pairs, bmo-miR-10b-3p/5p and bmo-miR-281-3p/5p, showed coordinate expression.</p> <p>Conclusions</p> <p>In this study, we conducted preliminary spatial measurements of several miRNAs in the silkworm. Periods of rapid morphological change were associated with alterations in miRNA expression patterns in the body wall, silk glands, midgut and fat body during metamorphosis. Accordingly, we propose that corresponding ubiquitous or tissue-specific expression of miRNAs supports their critical roles in tissue specification. These results should facilitate future functional analyses.</p
Bi/Bi2O3 sensor for quantitation of dissolved oxygen in molten salts
Abstract To quantify the oxygen content in molten salts, we examined the performance of an yttria-stabilized zirconia solid electrolyte oxygen sensor with a Bi/Bi2O3 reference electrode, focusing on its output accuracy. When the above sensor was tested in a flow of gas with known oxygen partial pressure, p O 2 , a linear relationship between l g p O 2 and the electromotive force (EMF) was observed, and the correlation slope exhibited a positive deviation from Nernstian behavior. EMF measurements performed in molten NaClâKCl indicated that the oxygen content of this salt mixture increased with increasing oxygen partial pressure in the covering gas, in agreement with Henryâs law. Moreover, the EMF exhibited a linear decrease with increasing melt temperature of molten NaClâKCl, in agreement with the theoretical model. Finally, a relationship between the structure of molten NaClâKCl and its oxygen diffusion behavior was established. As a result, the developed sensor was demonstrated to be well suited for determining the oxygen content of molten salts
Stability of calcia-stabilized zirconia in fluoride molten salts under different voltage
A Dual-Responsive Supra-Amphiphilic Polypseudorotaxane Constructed from a Water-Soluble Pillar[7]arene and an Azobenzene-Containing Random Copolymer
Macromolecular supra-amphiphiles
refer to a kind of macromolecular
amphiphiles whose hydrophlic and hydrophobic parts are connected by
noncovalent forces. They have applications in various fields, such
as drug delivery, sensor systems, and biomedical materials. Here we
report a novel molecular recognition motif between a new thermoresponsive
water-soluble pillar[7]Âarene (<b>WP7</b>) and an azobenzene
derivative. Furthermore, we utilized this recognition motif to construct
the first pillararene-based supra-amphiphilic polypseudorotaxane which
can self-assemble to form vesicles in water. Due to the dual-responsiveness
of the molecular recognition motif (the thermoresponsiveness of <b>WP7</b> and photoresponsiveness of azobenzene), the reversible
transformations between solid nanospheres based on the self-assembly
of the polymer backbone and vesicles based on the self-assembly of
the supra-amphiphilic polypseudorotaxane were achieved by adjusting
the solution temperature or UVâvisible light irradiation. These
dual-responsive aggregation behaviors were further used in the controlled
release of water-soluble dye calcein molecules
Controlled Synthesis of ZnS Quantum Dots and ZnS Quantum Flakes with Graphene as a Template
Novel ZnS quantum dots (QDs) and ZnS quantum flakes (QFs)
were
successfully prepared with graphene nanosheets (GNs) as a special
template, and two unique heterostructures of ZnS/GNs were also obtained.
Due to the structure-directing template effect of GNs, the as-synthesized
ZnS with different morphologies, dots or flakes, were uniformly distributed
on the surface of GNs by controlling nucleation and growth. The two
different heterostructures of ZnS/GNs exhibited obvious photovoltaic
response, and ZnS/GN QFs-on-sheet heterostructures show higher photovoltage
than that of ZnS/GN QDs-on-sheet
Dual-Responsive [2]Pseudorotaxane On the basis of a pH-Sensitive Pillar[5]arene and Its Application in the Fabrication of Metallosupramolecular Polypseudorotaxane
Metallosupramolecular
polymer, an appealing polymeric material,
plays important roles in many fields including catalysis, electrochemical
devices, conducting materials and so on. As a class of metallosupramolecular
polymers, metallosupramolecular polypseudorotaxane has attracted great
attention not only because of its wide applications but also due to
its facile synthesis which is by metal coordination between metal
and macrocycle-based pseudorotaxane. The introducing of stimuli-responsive
property into the metallosupramolecular polypseudorotaxane system
will enrich their functionality. Herein, a triple stimuli-responsive
metallosupramolecular polypseudorotaxane constructed by pillararene-based
hostâguest interaction and copper coordination. First, a new
pH-sensitive pillar[5]Âarene host (<b>H</b>) was synthesized.
An azastilbenzene derivative, <i>trans</i>- 4,4â˛-vinylenedipyridine
(<i><b>trans</b></i>-<b>G</b>) was chosen as
the guest molecule to construct a [2]Âpseudorotaxane based on <b>H</b> and <i><b>trans</b></i>-<b>G</b>.
The [2]Âpseudorotaxane displayed pH- and photo- dual stimuli-responsiveness.
Then the [2]Âpseudorotaxane was used to construct a pH-, photo- and
cyanide-triple stimuli-responsive metallosupramolecular polypseudorotaxane
based on CuÂ(II) ion coordination
Making Use of Plant uORFs to Control Transgene Translation in Response to Pathogen Attack
Reducing crop loss to diseases is urgently needed to meet increasing food production challenges caused by the expanding world population and the negative impact of climate change on crop productivity. Disease-resistant crops can be created by expressing endogenous or exogenous genes of interest through transgenic technology. Nevertheless, enhanced resistance by overexpressing resistance-produced genes often results in adverse developmental affects. Upstream open reading frames (uORFs) are translational control elements located in the 5Ⲡuntranslated region (UTR) of eukaryotic mRNAs and may repress the translation of downstream genes. To investigate the function of three uORFs from the 5â˛-UTR of ACCELERATED CELL 11 (uORFsACD11), we develop a fluorescent reporter system and find uORFsACD11 function in repressing downstream gene translation. Individual or simultaneous mutations of the three uORFsACD11 lead to repression of downstream translation efficiency at different levels. Importantly, uORFsACD11-mediated translational inhibition is impaired upon recognition of pathogen attack of plant leaves. When coupled with the PATHOGENESIS-RELATED GENE 1 (PR1) promoter, the uORFsACD11 cassettes can upregulate accumulation of Arabidopsis thaliana LECTIN RECEPTOR KINASE-VI.2 (AtLecRK-VI.2) during pathogen attack and enhance plant resistance to Phytophthora capsici. These findings indicate that the uORFsACD11 cassettes can be a useful toolkit that enables a high level of protein expression during pathogen attack, while for ensuring lower levels of protein expression at normal conditions