Complex topological configurations are fertile ground for exploring emergent phenomena and exotic phases in condensed-matter physics. For example, the recent discovery of polarization vortices and ...their associated complex-phase coexistence and response under applied electric fields in superlattices of (PbTiO
)
/(SrTiO
)
suggests the presence of a complex, multi-dimensional system capable of interesting physical responses, such as chirality, negative capacitance and large piezo-electric responses
. Here, by varying epitaxial constraints, we discover room-temperature polar-skyrmion bubbles in a lead titanate layer confined by strontium titanate layers, which are imaged by atomic-resolution scanning transmission electron microscopy. Phase-field modelling and second-principles calculations reveal that the polar-skyrmion bubbles have a skyrmion number of +1, and resonant soft-X-ray diffraction experiments show circular dichroism, confirming chirality. Such nanometre-scale polar-skyrmion bubbles are the electric analogues of magnetic skyrmions, and could contribute to the advancement of ferroelectrics towards functionalities incorporating emergent chirality and electrically controllable negative capacitance.
The glucagon-like peptide-1 (GLP-1) is a multifaceted hormone with broad pharmacological potential. Among the numerous metabolic effects of GLP-1 are the glucose-dependent stimulation of insulin ...secretion, decrease of gastric emptying, inhibition of food intake, increase of natriuresis and diuresis, and modulation of rodent β-cell proliferation. GLP-1 also has cardio- and neuroprotective effects, decreases inflammation and apoptosis, and has implications for learning and memory, reward behavior, and palatability. Biochemically modified for enhanced potency and sustained action, GLP-1 receptor agonists are successfully in clinical use for the treatment of type-2 diabetes, and several GLP-1-based pharmacotherapies are in clinical evaluation for the treatment of obesity.
In this review, we provide a detailed overview on the multifaceted nature of GLP-1 and its pharmacology and discuss its therapeutic implications on various diseases.
Since its discovery, GLP-1 has emerged as a pleiotropic hormone with a myriad of metabolic functions that go well beyond its classical identification as an incretin hormone. The numerous beneficial effects of GLP-1 render this hormone an interesting candidate for the development of pharmacotherapies to treat obesity, diabetes, and neurodegenerative disorders
Summary
Background
As treatment goals in Crohn's disease (CD) evolve, targets now include clinical remission (CR), mucosal healing (MH) and biological remission C‐reactive protein normalisation ...(CRPnorm).
Aims
To evaluate the association of baseline factors and treatment with the achievement of different composite remission parameters at week 26.
Methods
This post hoc analysis of the SONIC trial evaluated different composite remission measures at week 26 in a subgroup of patients with Crohn's disease activity index (CDAI) scores, CRP, and endoscopic data available at baseline and week 26 (N = 188). Assessed composite remission measures were: CR (CDAI < 150) and MH (absence of any mucosal ulcerations), previously referred to as ‘deep remission;’ and alternative composite endpoints: CR + CRPnorm (CRP < 0.8 mg/dL); CRPnorm + MH; and CR + CRPnorm + MH.
Results
Among analysed patients, 136/188 (72.3%) achieved CR and 90/188 (47.9%) achieved MH at week 26. All composite outcomes were significantly greater (Bonferroni significance level, P ≤ 0.016) with combination therapy (i.e. infliximab and azathioprine; 52.3–63.6%) vs. azathioprine monotherapy (12.9–29.0%; p ≤ 0.005 for all comparisons). Composite remission rates including MH were significantly greater with combination therapy (52.3–56.9%) vs. infliximab (25.6–32.3%; P ≤ 0.015 for all comparisons except CRPnorm + MH, P = 0.017) and vs. azathioprine monotherapy (12.9–20.4%; P ≤ 0.002 for all comparisons). Median serum trough infliximab concentrations among patients who achieved MH or CR + MH were greater when compared with those among patients who did not achieve MH (P = 0.018) or CR + MH (P = 0.053). Among the subgroup of patients with early Crohn's disease, MH alone or in combination with composite remission criteria significantly improved clinical outcomes of patients who received combination therapy.
Conclusions
Combination therapy was more effective in achieving various composite remission measures vs. azathioprine or infliximab monotherapy. These data illustrate that ‘deep remission’ is achievable with combination therapy in a high percentage of patients with early Crohn's disease. ClinicalTrials.gov number: NCT00094458.
One of the most promising approaches to reach a high gain in inertial confinement fusion is the fast ignition scheme. In this scheme, a relativistic electron beam is generated; this passes through ...the imploded plasma and deposits parts of its energy in the core. However, the large angular spread of the relativistic electron beam and the poorly controlled compression of the target affect realization of the fast ignition technique. Here, we demonstrate that indirectly driven (that is, driven by X-rays generated inside a gold hohlraum) implosions with a ‘high-foot’ and a short-coast time of less than 200 ps allow us to tightly compress the shell. Furthermore, we show the ability to optimize the symmetry of the imploding shell by changing the hohlraum length, successfully tuning a suitable tube-shaped shell to compensate for the large angular spread of the relativistic electron beam and to enhance the electron-to-core coupling efficiency via resistive magnetic fields. Benefiting from those experimental techniques, a significant enhancement in neutron yield was achieved in our indirectly driven fast ignition experiments. These results pave the way towards high-coupling fast ignition experiments with indirectly driven targets similar to those at the National Ignition Facility.Experiments realizing the indirect-drive fast ignition scheme for inertial confinement fusion are reported. Enabled by a tightly compressed target, an increase of neutron yield is observed.
The c-Jun NH2-terminal kinase (JNK) pathway represents one subgroup of MAP kinases that are activated primarily by cytokines and exposure to environmental stress. Autophagy is a protein-degradation ...system characterized by the formation of double-membrane vacuoles termed autophagosomes. Autophagy-related gene beclin 1 plays a key role in autophagosome formation. However, the relationships between activation of JNK pathway, autophagy induction and Beclin 1 expression remain elusive. In this study, we used human cancer cell lines CNE2 and Hep3B to investigate the role of JNK-mediated Beclin 1 expression in ceramide-induced autophagic cell death. Ceramide-treated cells exhibited the characteristics of autophagy (that is, acidic vesicular organelle formation and the LC3-II generation). JNK was activated in these two cell lines exposed to ceramide and the phosphorylation of c-Jun also increased. In the meantime, we found that ceramide upregulated Beclin 1 expression in cancer cells. The upregulation of Beclin 1 expression could be blocked by SP600125 (a specific inhibitor of JNK) or a small interfering RNA (siRNA) directed against JNK1/2 or c-Jun. Chromatin immunoprecipitation and luciferase reporter analysis revealed that c-Jun was involved in the regulation of beclin 1 transcription in response to ceramide treatment. In addition, inhibition of JNK activity by SP600125 could inhibit autophagy induction by ceramide. Furthermore, Beclin 1 knockdown by siRNA also inhibited ceramide-mediated autophagic cell death. JNK-mediated Beclin 1 expression was also observed in topotecan-induced autophagy. These data suggest that activation of JNK pathway can mediate Beclin 1 expression, which plays a key role in autophagic cell death in cancer cells.
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