Superconductivity and charge density waves (CDWs) are competitive, yet coexisting, orders in cuprate superconductors. To understand their microscopic interdependence, a probe capable of discerning ...their interaction on its natural length and time scale is necessary. We use ultrafast resonant soft x-ray scattering to track the transient evolution of CDW correlations in YBa
Cu
O
after the quench of superconductivity by an infrared laser pulse. We observe a nonthermal response of the CDW order characterized by a near doubling of the correlation length within ≈1 picosecond of the superconducting quench. Our results are consistent with a model in which the interaction between superconductivity and CDWs manifests inhomogeneously through disruption of spatial coherence, with superconductivity playing the dominant role in stabilizing CDW topological defects, such as discommensurations.
High-temperature copper oxide superconductors consist of stacked CuO
planes, with electronic band structures and magnetic excitations that are primarily two-dimensional
, but with superconducting ...coherence that is three-dimensional. This dichotomy highlights the importance of out-of-plane charge dynamics, which has been found to be incoherent in the normal state
within the limited range of momenta accessible by optics. Here we use resonant inelastic X-ray scattering to explore the charge dynamics across all three dimensions of the Brillouin zone. Polarization analysis of recently discovered collective excitations (modes) in electron-doped copper oxides
reveals their charge origin, that is, without mixing with magnetic components
. The excitations disperse along both the in-plane and out-of-plane directions, revealing its three-dimensional nature. The periodicity of the out-of-plane dispersion corresponds to the distance between neighbouring CuO
planes rather than to the crystallographic c-axis lattice constant, suggesting that the interplane Coulomb interaction is responsible for the coherent out-of-plane charge dynamics. The observed properties are hallmarks of the long-sought 'acoustic plasmon', which is a branch of distinct charge collective modes predicted for layered systems
and argued to play a substantial part in mediating high-temperature superconductivity
.
Considerable evidences have shown that autophagy has an important role in tumor chemoresistance. However, it is still unknown whether the lncRNA HULC (highly upregulated in liver cancer) is involved ...in autophagy and chemoresistance of hepatocellular carcinoma (HCC). In this study, we for the first time demonstrated that treatment with antitumor reagents such as oxaliplatin, 5-fluorouracil and pirarubicin (THP) dramatically induced HULC expression and protective autophagy. Silencing of HULC sensitized HCC cells to the three antitumor reagents via inhibiting protective autophagy. Ectopic expression of HULC elicited the autophagy of HCC cells through stabilizing silent information regulator 1 (Sirt1) protein. The investigation for the corresponding mechanism by which HULC stabilized Sirt1 revealed that HULC upregulated ubiquitin-specific peptidase 22 (USP22), leading to the decrease of ubiquitin-mediated degradation of Sirt1 protein by removing the conjugated polyubiquitin chains from Sirt1. Moreover, we found that miR-6825-5p, miR-6845-5p and miR-6886-3p could decrease the level of USP22 protein by binding to the 3'-untranlated region of USP22 mRNA. All the three microRNAs (miRNAs) were downregulated by HULC, which resulted in the elevation of USP22. In addition, we showed that the level of HULC was positively correlated with that of Sirt1 protein in human HCC tissues. Collectively, our data reveals that the pathway 'HULC/USP22/Sirt1/ protective autophagy' attenuates the sensitivity of HCC cells to chemotherapeutic agents, suggesting that this pathway may be a novel target for developing sensitizing strategy to HCC chemotherapy.
After the discovery of stripelike order in lanthanum-based copper oxide superconductors, charge-ordering instabilities were observed in all cuprate families. However, it has proven difficult to ...distinguish between unidirectional (stripes) and bidirectional (checkerboard) charge order in yttrium- and bismuth-based materials. We used resonant x-ray scattering to measure the two-dimensional structure factor in the superconductor YBa2Cu3O6+y in reciprocal space. Our data reveal the presence of charge stripe order (i.e., locally unidirectional density waves), which may represent the true microscopic nature of charge modulation in cuprates. At the same time, we find that the well-established competition between charge order and superconductivity is stronger for charge correlations across the stripes than along them, which provides additional evidence for the intrinsic unidirectional nature of the charge order.
Long noncoding RNAs (lncRNAs) are emerging as new players in gene regulation and are associated with the development of cancers. To investigate the important role and mechanism of lncRNAs in the ...progression of gastric cancer, we screened lncRNAs in gastric cancer tissues and corresponding adjacent tissues, and assessed the effects on gastric cancer. Here, we report that BC032469, a novel lncRNA, expressed highly in gastric cancer tissues, and the upregulation was clinically associated with larger tumor size, poor differentiation and shorter survival of gastric cancer patients. Downregulation of BC032469 resulted in a significant inhibition of proliferation in vitro and in vivo. Mechanistically, BC032469 could directly bind to miR-1207-5p and effectively functioned as a sponge for miR-1207-5p to modulate the derepression of hTERT. Thus, BC032469 may function as a ceRNA to impair miR-1207-5p-dependent hTERT downregulation, suggesting that it may be clinically valuable as a poor prognostic biomarker of gastric cancer.
During the Last Glacial Maximum (LGM; ~20,000 years ago), the global ocean sequestered a large amount of carbon lost from the atmosphere and terrestrial biosphere. Suppressed CO
outgassing from the ...Southern Ocean is the prevailing explanation for this carbon sequestration. By contrast, the North Atlantic Ocean-a major conduit for atmospheric CO
transport to the ocean interior via the overturning circulation-has received much less attention. Here we demonstrate that North Atlantic carbon pump efficiency during the LGM was almost doubled relative to the Holocene. This is based on a novel proxy approach to estimate air-sea CO
exchange signals using combined carbonate ion and nutrient reconstructions for multiple sediment cores from the North Atlantic. Our data indicate that in tandem with Southern Ocean processes, enhanced North Atlantic CO
absorption contributed to lowering ice-age atmospheric CO
.
Highlights • We chose mandarin voles as model animal in present experiment. • Distribution of AR-IRs was significantly lower in the ethanol group. • Distribution of AVP-IRs was higher in the ethanol ...than for the control groups. • The serum levels of androgens were lower by ELISA in ethanol group.
In strongly correlated systems the strength of Coulomb interactions between electrons, relative to their kinetic energy, plays a central role in determining their emergent quantum mechanical phases. ...We perform resonant x-ray scattering on Bi
Sr
CaCu
O
, a prototypical cuprate superconductor, to probe electronic correlations within the CuO
plane. We discover a dynamic quasi-circular pattern in the x-y scattering plane with a radius that matches the wave vector magnitude of the well-known static charge order. Along with doping- and temperature-dependent measurements, our experiments reveal a picture of charge order competing with superconductivity where short-range domains along x and y can dynamically rotate into any other in-plane direction. This quasi-circular spectrum, a hallmark of Brazovskii-type fluctuations, has immediate consequences to our understanding of rotational and translational symmetry breaking in the cuprates. We discuss how the combination of short- and long-range Coulomb interactions results in an effective non-monotonic potential that may determine the quasi-circular pattern.
The United Kingdom has successfully implemented a salt reduction programme. We carried out a comprehensive analysis of the programme with an aim of providing a step-by-step guide of developing and ...implementing a national salt reduction strategy, which other countries could follow. The key components include (1) setting up an action group with strong leadership and scientific credibility; (2) determining salt intake by measuring 24-h urinary sodium, identifying the sources of salt by dietary record; (3) setting a target for population salt intake and developing a salt reduction strategy; (4) setting progressively lower salt targets for different categories of food, with a clear time frame for the industry to achieve; (5) working with the industry to reformulate food with less salt; (6) engaging and recruiting of ministerial support and potential threat of regulation by the Department of Health (DH); (7) clear nutritional labelling; (8) consumer awareness campaign; and (9) monitoring progress by (a) frequent surveys and media publicity of salt content in food, including naming and shaming, (b) repeated 24-h urinary sodium at 3-5 year intervals. Since the salt reduction programme started in 2003/2004, significant progress has been made as demonstrated by the reductions in salt content in many processed food and a 15% reduction in 24-h urinary sodium over 7 years (from 9.5 to 8.1 g per day, P<0.05). The UK salt reduction programme reduced the population's salt intake by gradual reformulation on a voluntary basis. Several countries are following the United Kingdom's lead. The challenge now is to engage other countries with appropriate local modifications. A reduction in salt intake worldwide will result in major public health improvements and cost savings.
Background
To date, no study assessing the associations among glycaemic index (GI), glycaemic load (GL) and progression to diabetes has focused specifically on prediabetes. Moreover, the available ...data on the association between these variables and regression to normal glucose regulation (NGR) are insufficient. Therefore, the present study aimed to evaluate the longitudinal associations among GI, GL and prediabetes outcomes.
Methods
This prospective study included 640 adults aged 40–79 years with prediabetes at baseline. Dietary data were assessed using a previously validated 3‐day food record. The participants were divided into three groups according to GI and GL tertiles. Outcomes were defined based on annual oral glucose tolerance test results.
Results
During a median of 5 years of follow‐up, 127 incident cases of diabetes and 249 incident cases of NGR were identified. Dietary GL was positively associated with the risk of developing diabetes and negatively associated with the likelihood of reaching NGR at least once. Comparing the highest and lowest tertiles of GL, the multivariable‐adjusted hazard ratios (95% confidence intervals) were 1.85 (1.07–3.21) for progression and 0.65 (0.44‐0.96) for regression. No association was observed between GI and prediabetes outcomes in the fully adjusted models.
Conclusions
Among patients with prediabetes, high dietary GL was positively associated with diabetes risk. Furthermore, a low‐GL diet contributed to an increased incidence of reaching NGR.
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