Design and Testing of a 100-mN Class Water Micropropulsion System Using Wire-Fed Magnesium Combustion

In this study, the brand-new micropropulsion system is introduced to cover the thrust performances shorthanded by the exiting systems. It uses water as an oxidizer and a magnesium wire as a fuel. We constructed the lab-scale model of this micropropulsion system, and conducted several experiments to obtain the reaction rate of magnesium wire in water-vapor flow. Reaction rate showed almost proportional dependence on water-vapor mass flow rate. We constructed the revised version of lab-scale model, and will continue experiments for detailed analysis of combustion

Expression of activin A in human keratinocytes at early stages of cultivation

AbstractActivins are members of the TGF-β superfamily and are classified into 3 types: activin A, which consists of a homodimer of βA, activin B, which consists of a homodimer of βB, and activin AB, which consists of a heterodimer of βAβB. We studied the expression of activin mRNAs by RT-PCR in normal human epidermis, cultured keratinocytes, and DJM-1 cells (a squamous cell carcinoma line). We could detect only activin A mRNA (βA) in normal human epidermis. In cultured keratinocyte and DJM-1 cells, activin βA mRNA was observed at 4 h but not at 96 h after plating. Activin A activity was detected in the conditioned medium of DJM-1 cells within 48 h. In addition, although follistatin mRNA was not observed in human epidermis in situ, it was transiently expressed in cultured cells at 4 h after plating. These findings suggest that the expression of these molecules in keratinocytes is associated with cell proliferation. In an in vitro tissue injury model, activin A was observed at the wound edge, where cell migration and proliferation may be activated. In DJM-1 cells cultured for 92 h, βA mRNA was observed 4 h after injury treatment. These findings suggest that activin A acts as a potent inducer of proliferation in vitro, at least in keratinocytes

AQUARIUS: The World\u27s First Water-Based Thruster Enabled 6U CubeSat to Complete Lunar Flyby

This paper presents the outcomes of the initial operations and on-orbit performance of AQUARIUS (AQUA ResIstojet propulsion System), a micro-propulsion system. AQUARIUS utilizes water as a propellant and is designed for trajectory control and reaction wheel desaturation of a 6U CubeSat, EQUULEUS (EQUilibriUm Lunar-Earth point 6U Spacecraft). The spacecraft was launched in November 2022 by SLS, following which the initial operations commenced. Both the spacecraft and the propulsion system were confirmed to be in good health during the checkout process. Performance evaluation of the propulsion system confirmed that it met the requirement to execute the first delta-V maneuver scheduled 38 hours after separation from the launch vehicle. The delta-V maneuver was successfully completed, achieving a total delta-V of 6.48 m/s. The propulsion system demonstrated an average thrust of 5.94 ± 0.21 mN. Subsequently, precise trajectory control maneuvers were carried out, resulting in a successful lunar flyby. As a result of these initial operations, AQUARIUS became the world\u27s first water propulsion system to successfully control its orbit in deep space

Challenges and Operations to Re-Establish Communications With EQUULEUS After Loss of Contact During Its Cruise to the Earth-Moon L2 Point

EQUULEUS (EQUilibriUm Lunar-Earth point 6U Spacecraft) is a 6U CubeSat developed by the University of Tokyo and JAXA. It was launched on November 16, 2022, aboard NASA’s SLS Artemis-1 with the objectives of demonstrating orbital maneuvering capabilities in the cis-lunar environment and observing Earth’s magnetosphere plasma. After completing its major orbital maneuvers and achieving full mission success, communication with EQUULEUS was lost in 18th May 2023. Rapid fault tree analysis and optical observations using large telescopes indicated the spacecraft was likely in an uncontrolled tumbling state. Recovery operations were planned to re-establish communication by identifying potential times for sufficient solar power generation. This paper describes the details of EQUULEUS’s recovery operation

Assembly of Massive Galaxies in a High-z Protocluster

We present the results of wide-field deep JHK imaging of the SSA22 field using MOIRCS instrument equipped with Subaru telescope. The observed field is 112 arcmin^2 in area, which covers the z=3.1 protocluster characterized by the overdensities of Ly Alpha emitters (LAEs) and Ly Alpha Blobs (LABs). The 5 sigma limiting magnitude is K_{AB} = 24.3. We extract the potential protocluster members from the K-selected sample by using the multi-band photometric-redshift selection as well as the simple color cut for distant red galaxies (DRGs; J-K_{AB}>1.4). The surface number density of DRGs in our observed fields shows clear excess compared with those in the blank fields, and the location of the densest area whose projected overdensity is twice the average coincides with the large-scale density peak of LAEs. We also found that K-band counterparts with z_{phot} = 3.1 are detected for 75% (15/20) of the LABs within their Ly Alpha halo, and the 40 % (8/20) of LABs have multiple components, which gives a direct evidence of the hierarchical multiple merging in galaxy formation. The stellar mass ofLABs correlates with their luminosity, isophotal area, and the Ly Alpha velocity widths, implying that the physical scale and the dynamical motion of Ly Alpha emission are closely related to their previous star-formation activities. Highly dust-obscured galaxies such as hyper extremely red objects (HEROs; J-K_{AB}>2.1) and plausible K-band counterparts of submillimeter sources are also populated in the high density region.Comment: 21pages, accepted for publication in Astrophysical Journa

Faint Quasars Live in the Same Number Density Environments as Lyman Break Galaxies at z∼4

Characterizing high-z quasar environments is key to understanding the co-evolution of quasars and the surrounding galaxies. To restrict their global picture, we statistically examine the g-dropout galaxy overdensity distribution around 570 faint quasar candidates at z ~ 4, based on the Hyper Suprime-Cam Subaru Strategic Program survey. We compare the overdensity significances of g-dropout galaxies around the quasars with those around g-dropout galaxies, and find no significant difference between their distributions. A total of 4 (22) out of the 570 faint quasars, 0.7_{-0.4}^{+0.4} (3.9_{-0.8}^{+0.8}) %, are found to be associated with the > 4 sigma overdense regions within an angular separation of 1.8 (3.0) arcmin, which is the typical size of protoclusters at this epoch. This is similar to the fraction of g-dropout galaxies associated with the > 4 sigma overdense regions. This result is consistent with our previous work that 1.3_{-0.9}^{+0.9} % and 2.0_{-1.1}^{+1.1} % of luminous quasars detected in the Sloan Digital Sky Survey exist in the > 4 sigma overdense regions within 1.8 and 3.0 arcmin separations, respectively. Therefore, we suggest that the galaxy number densities around quasars are independent of their luminosity, and most quasars do not preferentially appear in the richest protocluster regions at z ~ 4. The lack of an apparent positive correlation between the quasars and the protoclusters implies that: i) the gas-rich major merger rate is relatively low in the protocluster regions, ii) most high-z quasars may appear through secular processes, or iii) some dust-obscured quasars exist in the protocluster regions.Comment: 12 pages, 4 figure

Revealing the Hidden Spin-Polarized Bands in a Superconducting Tl Bilayer Crystal

The interplay of spin-orbit coupling and crystal symmetry can generate spin-polarized bands in materials only a few atomic layers thick, potentially leading to unprecedented physical properties. In the case of bilayer materials with global inversion symmetry, locally broken inversion symmetry can generate degenerate spin-polarized bands, in which the spins in each layer are oppositely polarized. Here, we demonstrate that the hidden spins in a Tl bilayer crystal are revealed by growing it on Ag(111) of sizable lattice mismatch, together with the appearance of a remarkable phenomenon unique to centrosymmetric hidden-spin bilayer crystals: a novel band splitting in both spin and space. The key to success in observing this novel splitting is that the interaction at the interface has just the right strength: it does not destroy the original wave functions of the Tl bilayer but is strong enough to induce an energy separation

Cardiovascular adverse reactions associated with escitalopram in patients with underlying cardiovascular diseases: a systematic review and meta-analysis

BackgroundDespite the anticipated efficacy of escitalopram in treating depression and anxiety in individuals with preexisting cardiovascular conditions, persistent concerns regarding its adverse effects have emerged. In this systematic review, we aimed to evaluate the cardiovascular safety profile of escitalopram compared with that of placebo in patients with underlying cardiovascular disease.MethodsWe used a predefined search strategy in PubMed, Cochrane Central Register of Controlled Trials, Embase, International Clinical Trials Registry Platform, and ClinicalTrials.gov to identify studies evaluating adverse cardiovascular reactions to escitalopram in patients with underlying cardiovascular disease. Randomized controlled trials (RCTs) that provided results on cardiovascular safety outcomes were included. Two independent reviewers screened the abstracts and full texts of the individual studies. The risk of bias was assessed using version 2 of the Cochrane risk-of-bias tool for randomized trials. The certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation approach.ResultsThe primary outcomes were the frequency of major adverse cardiovascular events (MACE), QTc prolongation, and discontinuation of study medication. We identified 5 RCTs with 773 participants who met the inclusion criteria. Escitalopram was not associated with significantly increased risk of MACE (risk ratio [RR] = 1.85; 95% confidence interval [CI] 0.80 to 4.26; I2 0%; 5 RCTs; n = 773, moderate certainty of evidence), discontinuation of study medication (RR = 1.03; 95% CI 0.84–1.26; I2 0%; 5 RCTs; n = 773, low certainty of evidence), and QTc prolongation (RR = 1.20; 95% CI 0.76–1.90; I2 0%; 4 RCTs; n = 646, low certainty of evidence).ConclusionEscitalopram does not significantly increase the risk of cardiovascular adverse reactions compared with placebo in patients with underlying cardiovascular disease. However, the presence of wide CIs and the limited number of included studies highlight the need for further studies with larger sample sizes to enhance the precision and reliability of these findings.Systematic review registration: International Prospective Register of Systematic Reviews [CRD42022298181]