191 research outputs found
Detecting paired and counterflow superfluidity via dipole oscillations
We suggest an experimentally feasible procedure to observe paired and
counterflow superfluidity in ultra-cold atom systems. We study the time
evolution of one-dimensional mixtures of bosonic atoms in an optical lattice
following an abrupt displacement of an additional weak confining potential. We
find that the dynamic responses of the paired superfluid phase for attractive
inter-species interactions and the counterflow superfluid phase for repulsive
interactions are qualitatively distinct and reflect the quasi long-range order
that characterizes these states. These findings suggest a clear experimental
procedure to detect these phases, and give an intuitive insight into their
dynamics.Comment: 4 pages,5 figure
Inkjet printed circuits with two-dimensional semiconductor inks for high-performance electronics
Air-stable semiconducting inks suitable for complementary logic are key to create low-power printed integrated circuits (ICs). High-performance printable electronic inks with two-dimensional materials have the potential to enable the next generation of high performance, low-cost printed digital electronics. Here we demonstrate air-stable, low voltage (< 5 V) operation of inkjet-printed n-type molybdenum disulfide (MoS2) and p-type indacenodithiophene-co-benzothiadiazole (IDT-BT) field-effect transistors (FETs), estimating a switching time of {\tau} ~ 3.3 {\mu}s for the MoS2 FETs. We achieve this by engineering high-quality MoS2 and air-stable IDT-BT inks suitable for inkjet-printing complementary pairs of n-type MoS2 and p-type IDT-BT FETs. We then integrate MoS2 and IDT-BT FETs to realise inkjet-printed complementary logic inverters with a voltage gain |Av| ~ 4 when in resistive load configuration and |Av| ~ 1.36 in complementary configuration. These results represent a key enabling step towards ubiquitous long-term stable, low-cost printed digital ICs
The Ankyrin Repeat Domain of the TRPA Protein Painless Is Important for Thermal Nociception but Not Mechanical Nociception
The Drosophila TRPA channel Painless is required for the function of polymodal nociceptors which detect noxious heat and noxious mechanical stimuli. These functions of Painless are reminiscent of mammalian TRPA channels that have also been implicated in thermal and mechanical nociception. A popular hypothesis to explain the mechanosensory functions of certain TRP channels proposes that a string of ankyrin repeats at the amino termini of these channels acts as an intracellular spring that senses force. Here, we describe the identification of two previously unknown Painless protein isoforms which have fewer ankyrin repeats than the canonical Painless protein. We show that one of these Painless isoforms, that essentially lacks ankyrin repeats, is sufficient to rescue mechanical nociception phenotypes of painless mutant animals but does not rescue thermal nociception phenotypes. In contrast, canonical Painless, which contains Ankyrin repeats, is sufficient to largely rescue thermal nociception but is not capable of rescuing mechanical nociception. Thus, we propose that in the case of Painless, ankryin repeats are important for thermal nociception but not for mechanical nociception
MDM2 and Fbw7 cooperate to induce p63 protein degradation following DNA damage and cell differentiation
Tight control of p63 protein levels must be achieved under differentiation or apoptotic conditions. Here, we describe a new regulatory pathway for the \u394Np63\u3b1 protein. We found that MDM2 binds \u394Np63\u3b1 in the nucleus promoting its translocation to the cytoplasm. The MDM2 nuclear localization signal is required for \u394Np63\u3b1 nuclear export and subsequent degradation, whereas the MDM2 ring-finger domain is dispensable. Once exported to the cytoplasm by MDM2, p63 is targeted for degradation by the Fbw7 E3-ubiquitin ligase. Efficient degradation of \u394Np63\u3b1 by Fbw7 (also known as FBXW7) requires GSK3 kinase activity. By deletion and point mutations analysis we have identified a phosphodegron located in the \u3b1 and \u3b2 tail of p63 that is required for degradation. Furthermore, we show that MDM2 or Fbw7 depletion inhibits degradation of endogenous \u394Np63\u3b1 in cells exposed to UV irradiation, adriamycin and upon keratinocyte differentiation. Our findings suggest that following DNA damage and cellular differentiation MDM2 and Fbw7 can cooperate to regulate the levels of the pro-proliferative \u394Np63\u3b1 protein
Inkjet Printed Circuits with 2D Semiconductor Inks for High-Performance Electronics
Funder: Imperial College London; Id: http://dx.doi.org/10.13039/501100000761Abstract: Air‐stable semiconducting inks suitable for complementary logic are key to create low‐power printed integrated circuits (ICs). High‐performance printable electronic inks with 2D materials have the potential to enable the next generation of high performance low‐cost printed digital electronics. Here, the authors demonstrate air‐stable, low voltage (<5 V) operation of inkjet‐printed n‐type molybdenum disulfide (MoS2), and p‐type indacenodithiophene‐co‐benzothiadiazole (IDT‐BT) field‐effect transistors (FETs), estimating an average switching time of τMoS2 ≈ 4.1 μs for the MoS2 FETs. They achieve this by engineering high‐quality MoS2 and air‐stable IDT‐BT inks suitable for inkjet‐printing complementary pairs of n‐type MoS2 and p‐type IDT‐BT FETs. They then integrate MoS2 and IDT‐BT FETs to realize inkjet‐printed complementary logic inverters with a voltage gain |Av| ≈ 4 when in resistive load configuration and |Av| ≈ 1.4 in complementary configuration. These results represent a key enabling step towards ubiquitous long‐term stable, low‐cost printed digital ICs
Regulation of Energy Stores and Feeding by Neuronal and Peripheral CREB Activity in Drosophila
The cAMP-responsive transcription factor CREB functions in adipose tissue and liver to regulate glycogen and lipid metabolism in mammals. While Drosophila has a homolog of mammalian CREB, dCREB2, its role in energy metabolism is not fully understood. Using tissue-specific expression of a dominant-negative form of CREB (DN-CREB), we have examined the effect of blocking CREB activity in neurons and in the fat body, the primary energy storage depot with functions of adipose tissue and the liver in flies, on energy balance, stress resistance and feeding behavior. We found that disruption of CREB function in neurons reduced glycogen and lipid stores and increased sensitivity to starvation. Expression of DN-CREB in the fat body also reduced glycogen levels, while it did not affect starvation sensitivity, presumably due to increased lipid levels in these flies. Interestingly, blocking CREB activity in the fat body increased food intake. These flies did not show a significant change in overall body size, suggesting that disruption of CREB activity in the fat body caused an obese-like phenotype. Using a transgenic CRE-luciferase reporter, we further demonstrated that disruption of the adipokinetic hormone receptor, which is functionally related to mammalian glucagon and β-adrenergic signaling, in the fat body reduced CRE-mediated transcription in flies. This study demonstrates that CREB activity in either neuronal or peripheral tissues regulates energy balance in Drosophila, and that the key signaling pathway regulating CREB activity in peripheral tissue is evolutionarily conserved
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