224 research outputs found
Adaptive channel selection in IEEE 802.15.4 TSCH networks
Additional files 6: Table S5. Four conjugative transposon gene clusters in the Chryseobacterium indologenes J31 genome
Coordination Synergy between Iridium Photosensitizers and Metal Nanoclusters Leading to Enhanced CO<sub>2</sub> Cycloaddition under Mild Conditions
The achievement of photocatalytic CO2 and
epoxide cycloaddition
under mild conditions such as room temperature and atmospheric pressure
is important for green chemistry, which can be achieved by developing
coordination synergies between catalysts and photosensitizers. In
this context, we exploit the use of coordinate bonds to connect pyridine-appended
iridium photosensitizers and catalysts for CO2 cycloaddition,
which is systematically demonstrated by 1H nuclear magnetic
resonance titration and X-ray photoelectron spectroscopic measurements.
It is shown that the hybrid Ir(Cltpy)2/Mn2Cd4 photocatalytic system with coordination synergy exhibits
excellent catalytic performance (yield ≈ 98.2%), which is 3.75
times higher than that of the comparative Ir(Cltpy-Ph)2/Mn2Cd4 system without coordination synergy
(yield ≈ 26.2%), under mild conditions. The coordination between
the Mn2Cd4 catalyst and the Ir(Cltpy)2 photosensitizer enhances the light absorption and photoresponse
properties of the Mn2Cd4 catalyst. This has
been confirmed through transient photocurrent, electrochemical impedance,
and electron paramagnetic tests. Consequently, the efficiency of cycloaddition
was enhanced by utilizing mild conditions
I<sub>h</sub> Channels Control Feedback Regulation from Amacrine Cells to Photoreceptors
<div><p>In both vertebrates and invertebrates, photoreceptors’ output is regulated by feedback signals from interneurons that contribute to several important visual functions. Although synaptic feedback regulation of photoreceptors is known to occur in <i>Drosophila</i>, many questions about the underlying molecular mechanisms and physiological implementation remain unclear. Here, we systematically investigated these questions using a broad range of experimental methods. We isolated two <i>I<sub>h</sub></i> mutant fly lines that exhibit rhythmic photoreceptor depolarization without light stimulation. We discovered that I<sub>h</sub> channels regulate glutamate release from amacrine cells by modulating calcium channel activity. Moreover, we showed that the eye-enriched kainate receptor (EKAR) is expressed in photoreceptors and receives the glutamate signal released from amacrine cells. Finally, we presented evidence that amacrine cell feedback regulation helps maintain light sensitivity in ambient light. Our findings suggest plausible molecular underpinnings and physiological effects of feedback regulation from amacrine cells to photoreceptors. These results provide new mechanistic insight into how synaptic feedback regulation can participate in network processing by modulating neural information transfer and circuit excitability.</p></div
Table_1_The intricate dance: host autophagy and Coxiella burnetii infection.DOCX
Q fever is a zoonotic disease caused by Coxiella burnetii, an obligatory intracellular bacterial pathogen. Like other intracellular pathogens, C. burnetii is able to survive and reproduce within host cells by manipulating host cellular processes. In particular, the relationship between C. burnetii infection and host autophagy, a cellular process involved in degradation and recycling, is of great interest due to its intricate nature. Studies have shown that autophagy can recognize and target intracellular pathogens such as Legionella and Salmonella for degradation, limiting their replication and promoting bacterial clearance. However, C. burnetii can actively manipulate the autophagic pathway to create an intracellular niche, known as the Coxiella-containing vacuole (CCV), where it can multiply and evade host immune responses. C. burnetii promotes the fusion of CCVs with lysosomes through mechanisms involving virulence factors such as Cig57 and CvpF. This review summarizes the latest findings on the dynamic interaction between host autophagy and C. burnetii infection, highlighting the complex strategies employed by both the bacterium and the host. A better understanding of these mechanisms could provide important insights into the development of novel therapeutic interventions and vaccine strategies against C. burnetii infections.</p
Single-Nucleotide Mutation Matrix: A New Model for Predicting the NF-κB DNA Binding Sites
<div><p>In this study, we established a single nucleotide mutation matrix (SNMM) model based on the relative binding affinities of NF-κB p50 homodimer to a wild-type binding site (GGGACTTTCC) and its all single-nucleotide mutants detected with the double-stranded DNA microarray. We evaluated this model by scoring different groups of 10-bp DNA sequences with this model and analyzing the correlations between the scores and the relative binding affinities detected with three wet experiments, including the electrophoresis mobility shift assay (EMSA), the protein-binding microarray (PBM) and the systematic evolution of ligands by exponential enrichment-sequencing (SELEX-Seq). The results revealed that the SNMM scores were strongly correlated with the detected binding affinities. We also scored the DNA sequences with other three models, including the principal coordinate (PC) model, the position weight matrix scoring algorithm (PWMSA) model and the Match model, and analyzed the correlations between the scores and the detected binding affinities. In comparison with these models, the SNMM model achieved reliable results. We finally determined 0.747 as the optimal threshold for predicting the NF-κB DNA-binding sites with the SNMM model. The SNMM model thus provides a new alternative model for scoring the relative binding affinities of NF-κB to the 10-bp DNA sequences and predicting the NF-κB DNA-binding sites.</p></div
Identification of glutamate receptor that mediates retrograde glutamate signaling from ACs to photoreceptors.
<p>(<b>A</b>) ERG traces of flies with iGluR depletion in photoreceptors. Photoreceptor-specific Rh1-GAL4 was used for iGluR screening. (<b>B</b>) Fractions of flies exhibit ERG oscillation phenotype and the numbers of recorded flies are presented.</p
The single-nucleotide mutant matrix (SNMM).
a<p>Base of the reference sequence (GGGACTTTCC). 1 to 10, base position in the 10-bp NF-κB DBS.</p
Expression patterns of endogenous I<sub>h</sub> channels.
<p>(<b>A</b>) Localization of endogenous I<sub>h</sub> channels in the adult fly head. Dissected whole heads were double stained with anti-I<sub>h</sub> (green) and 24B10 (red, for photoreceptor membrane) antibodies. The images show a longitudinal view of the retina (R), lamina (L), and medulla (M). (<b>B</b>) Distribution of I<sub>h</sub> channels in the lamina region. Images show a longitudinal view. (<b>C</b>) I<sub>h</sub> channels expressed in L1 neurons. L1 neurons were labeled with mCD8-GFP under the control of the <i>L1-GAL4</i> driver. Two L1 somata are indicated by arrows. (<b>D</b>). I<sub>h</sub> channels were highly expressed in L2 neurons. L2 neurons were labeled with mCD8-GFP under the control of the <i>L2-GAL4</i> driver. The upper panel shows a longitudinal view of the lamina, and the lower panel shows a cross view of the lamina. L2 somas are indicated by arrows. (<b>E</b>) I<sub>h</sub> channels were expressed in ACs. ACs (arrows) are labeled with mCD8-GFP under the control of the <i>Lai-GAL4</i> driver. The upper panel shows a longitudinal view of the retina (R), lamina (L) and medulla (M), and the middle and lower panels show a longitudinal and cross-sectional view of AC processes.</p
<i>I</i><sub>h</sub> mutant lines exhibit ERG baseline oscillation.
<p>(<b>A</b>) Annotated transcriptions of the <i>I</i><sub><i>h</i></sub> gene. Two <i>piggyBac</i> insertion sites are marked with triangles. The RNAi recognized site and coding region used for antibody generation are labeled at the top. (<b>B</b>) <i>I</i><sub><i>h</i></sub> mutant lines exhibit ERG baseline oscillation. For ERG traces throughout all figures, event markers represent 5-s orange light pulses, and scale bars are 5 mV. (<b>C</b>) Fraction of flies that exhibit the ERG oscillation phenotype in each genotype. The numbers of recorded flies for each genotype are listed. (<b>D</b>) RT-PCR shows <i>I</i><sub><i>h</i></sub> mRNAs are transcripted in wild-type flies but are absent in <i>I</i><sub><i>h</i></sub> mutant flies. Primer pair CACGCGACCAATCTCATCC/ TCATGGAGTGTTACCCTCG, which can amplify all transcriptional variants, was used in RT-PCR analysis. The tubulin gene was used as a loading control. (<b>E</b>) Western blotting revealed four major I<sub>h</sub> channel variants (indicated by arrows) expressed in wild-type flies but absent in <i>I</i><sub><i>h</i></sub> mutant flies. Note that the low-intensity bands presented in <i>I</i><sub><i>h</i></sub> mutant flies are nonspecific.</p
Depletion of I<sub>h</sub> channels in ACs results in rhythmic depolarization in photoreceptors.
<p>(<b>A</b>) I<sub>h</sub> channel expression levels in flies with I<sub>h</sub> channel depletion using <i>UAS-I</i><sub><i>h</i></sub>-<i>RNAi</i> driven by anatomically restricted GAL4 drivers. A single copy of the GAL4 driver was used for each GAL4 line. Each lane was loaded with two fly heads. The I<sub>h</sub> channel bands are indicated with arrows. (<b>B</b>) ERG traces of flies with I<sub>h</sub> channels depletion using <i>UAS-I</i><sub><i>h</i></sub>-<i>RNAi</i> driven by anatomically restricted GAL4 drivers. A single copy of the GAL4 driver was used for each GAL4 line. (<b>C</b>) The fraction of flies that exhibit ERG oscillation phenotype in each genotype. The numbers of recorded flies for each genotype are listed. (<b>D</b>) Expression of I<sub>h</sub> channels in <i>UAS-mCD8-GFP</i>,<i>UAS-I</i><sub><i>h</i></sub>-<i>RNAi/Lai-Gal4</i> (bottom) and control (top) flies. Dissected whole brains were stained with anti-I<sub>h</sub> (red) and anti-GFP (green) antibodies. Note that I<sub>h</sub> channel distribution in <i>UAS-mCD8-GFP</i>,<i>UAS-I</i><sub><i>h</i></sub>-<i>RNAi/Lai-Gal4</i> flies is comparable to control flies except in ACs.</p
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