Dental pulp regeneration therapy for the pulpless tooth has attracted recent attention, and clinical trial studies are underway with the tissue engineering approach. However, there remain many ...concerns, including the extended period for regenerating the dental pulp. In addition, the use of scaffolds increases the risk of inflammation and infection. To establish a basic technology for novel dental pulp regenerative therapy that allows transplant of pulp-like tissue, we attempted to fabricate scaffold-free 3-dimensional (3D) cell constructs composed of dental pulp stem cells (DPSCs). Furthermore, we assessed viability of these 3D DPSC constructs for dental pulp regeneration through in vitro and in vivo studies. For the in vitro study, we obtained 3D DPSC constructs by shaping sheet-like aggregates of DPSCs with a thermoresponsive hydrogel. DPSCs within constructs remained viable even after prolonged culture; furthermore, 3D DPSC constructs possessed a self-organization ability necessary to serve as a transplant tissue. For the in vivo study, we filled the human tooth root canal with DPSC constructs and implanted it subcutaneously into immunodeficient mice. We found that pulp-like tissues with rich blood vessels were formed within the human root canal 6 wk after implantation. Histologic analyses revealed that transplanted DPSCs differentiated into odontoblast-like mineralizing cells at sites in contact with dentin; furthermore, human CD31–positive endothelial cells were found at the center of regenerated tissue. Thus, the self-organizing ability of 3D DPSC constructs was active within the pulpless root canal in vivo. In addition, blood vessel–rich pulp-like tissues can be formed with DPSCs without requiring scaffolds or growth factors. The technology established in this study allows us to prepare DPSC constructs with variable sizes and shapes; therefore, transplantation of DPSC constructs shows promise for regeneration of pulpal tissue in the pulpless tooth.
Context.
The discovery of an extrasolar planet with an ocean has crucial importance in the search for life beyond Earth. The polarimetric detection of specularly reflected light from a smooth liquid ...surface is anticipated theoretically, though the polarimetric signature of Earth’s oceans has not yet been conclusively detected in disk-integrated planetary light.
Aims.
We aim to detect and measure the polarimetric signature of the Earth’s oceans.
Methods.
We conducted near-infrared polarimetry for lunar Earthshine and collected data on 32 nights with a variety of ocean fractions in the Earthshine-contributing region.
Results.
A clear positive correlation was revealed between the polarization degree and ocean fraction. We found hourly variations in polarization in accordance with rotational transition of the ocean fraction. The ratios of the variation to the typical polarization degree were as large as ~0.2–1.4.
Conclusions.
Our observations provide plausible evidence of the polarimetric signature attributed to Earth’s oceans. Near-infrared polarimetry may be considered a prospective technique in the search for exoplanetary oceans.
Abstract
Environmental noise is one of the critical issues for the observation of gravitational waves, but is difficult to predict in advance. Therefore, to evaluate the adverse impact of ...environmental noise on the detector sensitivity, understanding the detector response to the environmental noise in actual setup is crucial, for both the observation and future upgrades. In this paper, we introduce and verify a new method of the environmental noise injection test based on the post-observation commissioning of KAGRA. This new method (response function model) includes the frequency conversion and nonlinearity of power, which are the effects that are not considered in the current model (coupling function model) used in LIGO and Virgo. We also confirmed the validity of our method by applying it to an environmental noise-enriched dataset and successfully reproducing them.
Chronic stress-induced aberrant gene expression in the brain and subsequent dysfunctional neuronal plasticity have been implicated in the etiology and pathophysiology of mood disorders. In this ...study, we examined whether altered expression of small, regulatory, noncoding microRNAs (miRNAs) contributes to the depression-like behaviors and aberrant neuronal plasticity associated with chronic stress. Mice exposed to chronic ultra-mild stress (CUMS) exhibited increased depression-like behaviors and reduced hippocampal expression of the brain-enriched miRNA-124 (miR-124). Aberrant behaviors and dysregulated miR-124 expression were blocked by chronic treatment with an antidepressant drug. The depression-like behaviors are likely not conferred directly by miR-124 downregulation because neither viral-mediated hippocampal overexpression nor intrahippocampal infusion of an miR-124 inhibitor affected depression-like behaviors in nonstressed mice. However, viral-mediated miR-124 overexpression in hippocampal neurons conferred behavioral resilience to CUMS, whereas inhibition of miR-124 led to greater behavioral susceptibility to a milder stress paradigm. Moreover, we identified histone deacetylase 4 (HDAC4), HDAC5, and glycogen synthase kinase 3β (GSK3β) as targets for miR-124 and found that intrahippocampal infusion of a selective HDAC4/5 inhibitor or GSK3 inhibitor had antidepressant-like actions on behavior. We propose that miR-124-mediated posttranscriptional controls of HDAC4/5 and GSK3β expressions in the hippocampus have pivotal roles in susceptibility/resilience to chronic stress.
Depressive disorders are a major public health concern worldwide. Although a clear understanding of the etiology of depression is still lacking, chronic stress-elicited aberrant neuronal plasticity has been implicated in the pathophysiology of depression. We show that the hippocampal expression of microRNA-124 (miR-124), an endogenous small, noncoding RNA that represses gene expression posttranscriptionally, controls resilience/susceptibility to chronic stress-induced depression-like behaviors. These effects on depression-like behaviors may be mediated through regulation of the mRNA or protein expression levels of histone deacetylases HDAC4/5 and glycogen synthase kinase 3β, all highly conserved miR-124 targets. Moreover, miR-124 contributes to stress-induced dendritic hypotrophy and reduced spine density of dentate gyrus granule neurons. Modulation of hippocampal miR-124 pathways may have potential antidepressant effects.
We have magnetized the EuBaCuO ring bulk reinforced by a stainless steel ring during field-cooled magnetization (FCM) at 50 K under the magnetic fields from 6.3, 7.3 or 8.3 T, in which the ring bulk ...was broken at the intermediate step of FCM from 8.3 T. To discuss the fracture behavior of the bulk, we have performed the numerical simulation using a three dimensional finite element method for the bulk with realistic superconducting characteristics, and obtained both the electromagnetic hoop stress, θ FCM , during FCM and thermal hoop stress, θ cool , under cooling from 300 to 50 K. The difference of the thermal contraction coefficient between the bulk and the stainless steel ring caused an inhomogeneous θ cool profile with a tensile stress at the outermost edge on the bulk surface under cooling process. The maximum of the total hoop stress, θ total ( = θ FCM + θ cool ) , was estimated to be +50 MPa and +59 MPa during FCM from 7.3 T and 8.3 T, respectively. These results suggest that the actual fracture strength of the present ring bulk is between 50 and 59 MPa. The θ total value should be reduced as low as possible in the whole area of the bulk to avoid the fracture behavior during FCM.
•High temperature superconducting induction/synchronous motor.•Fully superconducting motor by the use of BSCCO tapes.•Nonlinear resistances of superconducting windings and nonlinear inductances of ...silicon steel core.•Quantitative characterization of load characteristics.
This paper reports an optimal technique to design a fully superconducting motor. A 50-kW-class fully superconducting induction/synchronous motor with both rotor and stator windings was fabricated from bismuth–strontium–calcium–copper-oxide (BSCCO) tapes and quantitatively characterized. The toroidal structure was adopted for the stator windings in order to increase their critical current in the iron core, and a squirrel-cage structure was used for the rotor windings. The three-phase AC loss was measured in atmospheric liquid nitrogen (77 K), and characterized as a function of the stator current and its frequency. Nonlinear self-inductance as well as mutual- inductance of the silicon steel core was estimated based on experimental and analytical methods. These nonlinear parameters were introduced into the voltage equations and then coupled with the equation of motion. The measured load characteristics were quantitatively reproduced despite complex nonlinear parameters.
Variability in bacterial sterilization is a key feature of Mycobacterium tuberculosis (Mtb) disease. In a population of human macrophages, there are macrophages that restrict Mtb growth and those ...that do not. However, the sources of heterogeneity in macrophage state during Mtb infection are poorly understood. Here, we perform RNAseq on restrictive and permissive macrophages and reveal that the expression of genes involved in GM-CSF signaling discriminates between the two subpopulations. We demonstrate that blocking GM-CSF makes macrophages more permissive of Mtb growth while addition of GM-CSF increases bacterial control. In parallel, we find that the loss of bacterial control that occurs in HIV-Mtb coinfected macrophages correlates with reduced GM-CSF secretion. Treatment of coinfected cells with GM-CSF restores bacterial control. Thus, we leverage the natural variation in macrophage control of Mtb to identify a critical cytokine response for regulating Mtb survival and identify components of the antimicrobial response induced by GM-CSF.
Silica has the highest demonstrated potential of any phase to preserve microfossils on Earth and therefore may host potential biosignatures on Mars. We detected hydrated silica in Jezero crater, the ...landing site of the National Aeronautics and Space Administration's Mars 2020 rover mission, by applying Dynamic Aperture Factor Analysis/Target Transformation to images from the Compact Reconnaissance Imaging Spectrometer for Mars. Hydrated silica detections with Dynamic Aperture Factor Analysis/Target Transformation were verified using commonly accepted Compact Reconnaissance Imaging Spectrometer for Mars analysis methods. The morphology of geologic units associated with silica was characterized with high‐resolution imaging. Several hypotheses are presented for the formation environment of hydrated silica. All are testable via in situ investigation. We assess the likelihood of silica to preserve biosignatures in these different scenarios based on habitability considerations and biosignature preservation in Earth analog environments and materials. Also reported are possible detections of hydrated silica in the Nili Fossae basement and olivine‐rich units, as well as Al‐phyllosilicate within Jezero crater.
Key Points
Hydrated silica is detected in Jezero crater and could have formed in a variety of environments with different degrees of habitability
Hydrated silica is associated with smooth dark‐toned material that covers the olivine‐rich unit
Hydrated silica in Jezero crater is an excellent target for in situ investigation for biosignatures
Polarized Raman spectra were measured from (010) Mg-doped, (100) Si-doped, and (001) unintentionally-doped β-Ga2O3 substrates prepared by either the floating zone growth or edge-defined film-fed ...growth methods. The Ag and Bg Raman active modes were perfectly separated in the spectra according to the polarization selection rules. To the best of our knowledge, this is the first experimental observation of a complete set of polarized Raman spectra of β-Ga2O3. The results are ensured by the high uniformity of crystalline orientation and surface flatness of the present substrates.
•Polarized Raman spectra were measured from β-Ga2O3 substrates.•The substrates were prepared by either the floating zone growth or edge-defined film-fed growth methods.•The polarization selection rules were perfectly reproduced in the spectra.•This is the first experimental observation of the complete set of polarized Raman spectra of β-Ga2O3.•The results imply high crystalline quality of the present substrates.
We have investigated a new reinforcement hat structure for a RE-Ba-Cu-O (REBaCuO, RE: rare earth element or Y) ring-shaped bulk superconductor (ring bulk) shrink-fitted with a double Al alloy ring ...and set on the cold stage of a cryogenic refrigerator prior to field-cooled magnetisation (FCM). With the hat structure, a ring bulk having an outer diameter of 64 mm, inner diameter of 40 mm, and height of 20.5 mm achieved a trapped field as high as 6.8 T at 50 K during FCM with an applied magnetic field at Bapp = 10 T without fracture; a similar ring bulk without the hat structure broke during FCM at Bapp = 8.8 T. Using a numerical simulation for electromagnetic and mechanical properties, the potential benefit of the hat structure was confirmed. The magnetic field dependence of the average critical current density Jc(B) of the ring bulk used in the simulation was determined by experimental results of time step dependence of the trapped field Bz at the bulk centre. As a result, the total hoop stress θtotal in the ring bulk including the resulting stress of cooling from 300 K to 50 K and subsequent FCM at Bapp = 10 T is lower than the fracture strength of a typical Ag-doped REBaCuO bulk material. The effect of double Al alloy ring reinforcement was also analysed using a numerical simulation and compared with that of the conventional single Al alloy ring reinforcement. These results suggest that the double ring provides only a limited benefit, whereas the hat structure is fairly effective in reducing the electromagnetic hoop stress during FCM at Bapp = 10 T. Using this reinforcement method, a 400 MHz (9.4 T) nuclear magnetic resonance bulk magnet system could be realised.
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