73 research outputs found
Quantum Multicritical Behavior for Coupled Optical Cavities with Driven Laser Fields
Quantum phase transitions with multicritical points are fascinating phenomena
occurring in interacting quantum many-body systems. However, multicritical
points predicted by theory have been rarely verified experimentally; finding
multicritical points with specific behaviors and realizing their control
remains a challenging topic. Here, we propose a system that a quantized light
field interacts with a two-level atomic ensemble coupled by microwave fields in
optical cavities, which is described by a generalized Dicke model.
Multicritical points for the superradiant quantum phase transition are shown to
occur. We determine the number and position of these critical points and
demonstrate that they can be effectively manipulated through the tuning of
system parameters. Particularly, we find that the quantum critical points can
evolve into a Lifshitz point if the Rabi frequency of the light field is
modulated periodically in time. Remarkably, the texture of atomic pseudo-spins
can be used to characterize the quantum critical behaviors of the system. The
magnetic orders of the three phases around the Lifshitz point, represented by
the atomic pseudo-spins, are similar to those of an axial
next-nearest-neighboring Ising model. The results reported here are beneficial
for unveiling intriguing physics of quantum phase transitions and pave the way
towards to find novel quantum multicritical phenomena based on the generalized
Dicke model
Inhibition of Stimulator of Interferon Genes Protects Against Myocardial Ischemia-Reperfusion Injury in Diabetic Mice
Background: Although the past decade has witnessed substantial scientific progress with the advent of cardioprotective pharmacological agents, most have failed to protect against myocardial ischemia/reperfusion (I/R) injury in diabetic hearts. This study was aimed at investigating the role of stimulator of interferon genes (STING) in I/R injury in diabetic mice and further exploring the underlying mechanisms. Methods: Type 2 diabetic mice were subjected to I/R or sham operation to investigate the role of STING. STING knockout mice were subjected to 30 minutes of ischemia followed by reperfusion for 24 hours. Finally, myocardial injury, cardiac function, and inflammation levels were assessed. Results: STING pathway activation was observed in diabetic I/R hearts, as evidenced by increased p-TBK and p-IRF3 expression. STING knockout significantly decreased the ischemic area and improved cardiac function after I/R in diabetic mice. STING knockout also elicited cardio-protective effects by decreasing serum cardiac troponin T and lactate dehydrogenase levels, thus diminishing the inflammatory response in the heart after I/R in diabetic mice. In vitro , STING inhibition decreased the expression of hypoxia-re-oxygenation-induced inflammatory cytokines. Conclusions: Targeting STING inhibits inflammation and prevents I/R injury in diabetic mice. Thus, STING may be a potential novel therapeutic target against myocardial I/R injury in diabetes
A Study of the Mechanisms of Guaiacol Pyrolysis Based on Free Radicals Detection Technology
In order to understand the reaction mechanism of lignin pyrolysis, the pyrolysis process of guaiacol (o-methoxyphenol) as a lignin model compound was studied by free radical detection technology (electron paramagnetic resonance, EPR) in this paper. It was proven that the pyrolysis reaction of guaiacol is a free radical reaction, and the free radicals which can be detected mainly by EPR are methyl radicals. This paper proposes a process in which four free radicals (radicals 1- C6H4(OH)O*, radicals 5- C6H4(OCH3)O*, methyl radicals, and hydrogen radicals) are continuously rearranged during the pyrolysis of guaiacol
Detecting Land Subsidence in Shanghai by PS-Networking SAR Interferometry
Existing studies have shown that satellite synthetic aperture radar (SAR) interferometry has two apparent drawbacks, i.e., temporal decorrelation and atmospheric contamination, in the application of deformation mapping. It is however possible to improve deformation analysis by tracking some natural or man-made objects with steady radar reflectivity, i.e., permanent scatterers (PS), in the frame of time series of SAR images acquired over the same area. For detecting land subsidence in Shanghai, China, this paper presents an attempt to explore an approach of PS-neighborhood networking SAR interferometry. With use of 26 ERS-1/2 SAR images acquired 1992 through 2002 over Shanghai, the analysis of subsiding process in time and space is performed on the basis of a strong network which is formed by connecting neighboring PSs according to a distance threshold. The linear and nonlinear subsidence, atmospheric effects as well as topographic errors can be separated effectively in this way. The subsidence velocity field in 10 years over Shanghai is also derived. It was found that the annual subsidence rates in the study area range from -2.1 to -0.6 cm/yr, and the averaged subsidence rate reaches -1.1 cm/yr
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Hippocampal alpha-synuclein mediates depressive-like behaviors
•SNCA is up-regulated in the peripheral blood of major depressive disorder patients and in the hippocampus of depressive mice.•SNCA overexpression in the hippocampus induces depressive-like behaviors in mice, while SNCA knockout has antidepressant effects.•SNCA in hippocampus leads to synapse loss and neuronal cell death involved in depressive-like behaviors probably via complement system.•Complement system may play a key role in pathogenesis and progression of depressive disorder via microglia-mediated engulfment of synapses during inflammation.
Alpha-synuclein (α-syn) which encoded by SNCA plays a critical role in the neurotransmission, vesicle dynamics, and neuroplasticity. Alteration to SNCA expression is associated with major depressive disorder. However, the pathogenic mechanism of SNCA in depression remains unknown. Herein, we reported that SNCA was up-regulated in the peripheral blood of major depressive disorder (MDD) patients and the depressive mice. Chronic restraint stress (CRS) also up-regulated the SNCA expression in the hippocampus. Moreover, over-expression of SNCA in the hippocampus triggered spontaneous depressive-like behaviors under the non-stressed conditions in mice, and knockout of SNCA could reverse CRS-induced depressive-like behaviors. SNCA led to synapse loss and neuronal cell death in the hippocampus possibly via complement-mediated microglial engulfment and inflammation, and thus contributed to the pathogenesis of depressive disorder. Overall, hippocampal SNCA and complement system are involved in the pathogenesis of depressive disorder and it provides a new perspective for the occurrence of depressive disorder
Facing inevitable PARPis resistance: Mechanisms and therapeutic strategies for breast cancer treatment
Abstract BRCA1/2 gene mutations, which result in a dysfunction of homologous recombination repair, have been discovered in at least 5% of breast cancer (BC) patients with the increase in BC incidence in recent years. PARP inhibitors (PARPis), the first drugs with clinical approval based on synthetic lethality, have been approved to treat BRCA1/2‐mutant BC. However, as with other targeted drugs, PARPis drug resistance has become a significant obstacle in the application of PARPis. In this paper, we discuss the mechanism of PARPis, the clinical application of PARPis as monotherapy and the possible induced resistance mechanism. By exploring the resistance mechanism, we aimed to identify appropriate effective therapeutic techniques to overcome PARPis resistance and improve the efficacy of PARPis as well as to provide theoretical and experimental evidence for the clinical use of PARPis in BRCA1/2‐mutant BC
Ethanol and trafficking of 5-HT3A receptors
Univ Fed Sao Paulo, Dept Psicobiol, BR-04024002 Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Psicobiol, BR-04024002 Sao Paulo, BrazilWeb of Scienc
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