3,075 research outputs found
Imaging Neural Activity in the Primary Somatosensory Cortex Using Thy1-GCaMP6s Transgenic Mice
The mammalian brain exhibits marked symmetry across the sagittal plane. However, detailed description of neural dynamics in symmetric brain regions in adult mammalian animals remains elusive. In this study, we describe an experimental procedure for measuring calcium dynamics through dual optical windows above bilateral primary somatosensory corticies (S1) in Thy1-GCaMP6s transgenic mice using 2-photon (2P) microscopy. This method enables recordings and quantifications of neural activity in bilateral mouse brain regions one at a time in the same experiment for a prolonged period in vivo. Key aspects of this method, which can be completed within an hour, include minimally invasive surgery procedures for creating dual optical windows, and the use of 2P imaging. Although we only demonstrate the technique in the S1 area, the method can be applied to other regions of the living brain facilitating the elucidation of structural and functional complexities of brain neural networks
Experimental observation of superscattering
Superscattering, induced by degenerate resonances, breaks the fundamental
single-channel limit of scattering cross section of subwavelength structures;
in principle, an arbitrarily large total cross section can be achieved via
superscattering. It thus provides a unique way to strengthen the light-matter
interaction at the subwavelength scale, and has many potential applications in
sensing, energy harvesting, bio-imaging (such as magnetic resonance imaging),
communication and optoelectronics. However, the experimental demonstration of
superscattering remains an open challenge due to its vulnerability to
structural imperfections and intrinsic material losses. Here we report the
first experimental evidence for superscattering, by demonstrating the
superscattering simultaneously in two different frequency regimes through both
the far-field and near-field measurements. The underlying mechanism for the
observed superscattering is the degenerate resonances of confined surface
waves, by utilizing a subwavelength metasurface-based multilayer structure. Our
work paves the way towards practical applications based on superscattering
Tumor-Infiltrating Immune Cells and PD-L1 as Prognostic Biomarkers in Primary Esophageal Small Cell Carcinoma
Primary esophageal small cell carcinoma (PESCC) is a weakly prevalent but lethal malignancy with early metastasis and a poor prognosis. Currently, neither effective prognostic indicators nor curative therapies are available for PESCC. Immunotherapy has now evolved into one of the most promising therapies for cancer patients. Tumor-infiltrating immune cells which are integral to the tumor immune microenvironment (TIME) are recognized as highly important for prognosis prediction, while the responsiveness to immune checkpoint blockade may be subject to the features of TIME. In this study, we aim to identify the TIME and provide indication for the applicability of immune checkpoint therapy in PESCC. We found that PD-L1 expression was detected in 33.33% (27/81) of all the patients, mostly exhibiting a stroma-only pattern and that it was positively associated with tumor-infiltrating immune cells (CD4(+), CD8(+), and CD163(+)). In 74.07% of PD-L1-positive specimens, PD-L1(+)CD163(+) cells were colocalized more with CD4(+) than CD8(+) T cells. 83.95% (68/81) of all the specimens were infiltrated with more CD4(+) than CD8(+) T cells. Further analysis showed FoxP3(+) Tregs constituted 13-27% of the total CD4(+) T cell population. The Kaplan--Meier analysis indicated several factors that contribute to poor survival, including negative PD-L1 expression, rich CD4 expression, rich FoxP3 expression, a low CD8/CD4 ratio, and a high FoxP3/CD8 ratio. A nomogram model was constructed and showed good performance for survival prediction. These results highlight that a suppressive TIME contributes to poor survival of patients with PESCC. TIME analyses might be a promising approach to evaluate the possibility and effect of immune checkpoint-based immunotherapeutics in PESCC patients
Generalized Magneto-thermo-microstretch Response of a Half-space with Temperature-dependent Properties During Thermal Shock
Abstract The generalized magneto-thermoelastic problem of an infinite homogeneous isotropic microstretch half-space with temperature
Technique of quantum state transfer for a double Lambda atomic beam
The transfer technique of quantum states from light to collective atomic
excitations in a double type system is extended to matter waves in
this paper, as a novel scheme towards making a continuous atom laser. The
intensity of the output matter waves is found to be determined by the initial
relative phase of the two independent coherent probe lights, which may indicate
an interesting method for the measurement of initial relative phase of two
independent light sources.Comment: 5 pages, 2 figure
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