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.
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.
•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.
Context. Circumstellar disks and envelopes of low-mass young stellar objects (YSOs) contain significant amounts of ice. Such icy material will evolve to become volatile components of planetary ...systems, such as comets in our solar system. Aims. To investigate the composition and evolution of circumstellar ice around low-mass young stellar objects (YSOs), we observed ice absorption bands in the near infrared (NIR) towards eight YSOs ranging from class 0 to class II, among which seven are associated with edge-on disks. Methods. We performed slit-less spectroscopic observations using the grism mode of the InfraRed Camera (IRC) on board AKARI, which enables us to obtain full NIR spectra from 2.5 μm to 5 μm, including the CO2 band and the blue wing of the H2O band, which are inaccessible from the ground. We developed procedures to carefully process the spectra of targets with nebulosity. The spectra were fitted with polynomial baselines to derive the absorption spectra. The molecular absorption bands were then fitted with the laboratory database of ice absorption bands, considering the instrumental line profile and the spectral resolution of the grism dispersion element. Results. Towards the class 0-I sources (L1527, IRC-L1041-2, and IRAS 04302), absorption bands of H2O, CO2, CO, and XCN are clearly detected. Column density ratios of CO2 ice and CO ice relative to H2O ice are 21−28% and 13−46%, respectively. If XCN is OCN−, its column density is as high as 2−6% relative to H2O ice. The HDO ice feature at 4.1 μm is tentatively detected towards the class 0-I sources and HV Tau. Non-detections of the CH-stretching mode features around 3.5 μm provide upper limits to the CH3OH abundance of 26% (L1527) and 42% (IRAS 04302) relative to H2O. We tentatively detect OCS ice absorption towards IRC-L1041-2. Towards class 0-I sources, the detected features should mostly originate in the cold envelope, while CO gas and OCN− could originate in the region close to the protostar, where there are warm temperatures and UV radiation. We detect H2O ice band towards ASR41 and 2MASSJ 1628137-243139, which are edge-on class II disks. We also detect H2O ice and CO2 ice towards HV Tau, HK Tau, and UY Aur, and tentatively detect CO gas features towards HK Tau and UY Aur.
•High temperature superconducting induction/synchronous motor.•BSCCO superconducting stator winding located in silicon steel core.•Percolation depinning model and magnetic anisotropy.•Quantitative ...characterization of voltage vs. current characteristics.
In this paper, we report on the quantitative characteristics of the DC current transport property of a superconducting bismuth strontium calcium copper oxide (BSCCO) stator winding that is used in a superconducting motor. The winding is in a slot of silicon steel core, and the DC voltage of such a winding is measured as a function of the transport current in atmospheric liquid nitrogen. Precise distribution of the magnetic field vector on the winding is also obtained using a three-dimensional finite element method, and thereafter used for the quantitative calculation of the local electric field with the aid of nonlinear and distributed circuits. The total (end-to-end) voltage of the winding is obtained by summing up the local value. It is demonstrated that the developed analysis procedure reproduces the measured results of the DC voltage vs. current characteristics even though the tape experiences a complicated magnetic field vector. Our method is effective for the precise design of a high-temperature superconducting stator.
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