687 research outputs found
CD82/KAI1 Maintains the Dormancy of Long-Term Hematopoietic Stem Cells through Interaction with DARC- Expressing Macrophages
Hematopoiesis is regulated by crosstalk between long-term repopulating hematopoietic stem cells (LT-HSCs) and supporting niche cells in the bone marrow (BM). Here, we examine the role of CD82/ KAI1 in niche-mediated LT-HSC maintenance. We found that CD82/ KAI1 is expressed predominantly on LT-HSCs and rarely on other hematopoietic stem-progenitor cells (HSPCs). In Cd82 +/-/+/- mice, LTHSCs were selectively lost as they exited from quiescence and differentiated. Mechanistically, CD82based TGF-b1/ Smad3 signaling leads to induction of CDK inhibitors and cell-cycle inhibition. The CD82 binding partner DARC/ CD234 is expressed on macrophages and stabilizes CD82 on LT-HSCs, promoting their quiescence. When DARC + BMmacrophages were ablated, the level of surface CD82 on LT-HSCs decreased, leading to cell-cycle entry, proliferation, and differentiation. A similar interaction appears to be relevant for human HSPCs. Thus, CD82 is a functional surface marker of LT-HSCs that maintains quiescence through interaction with DARC-expressing macrophages in the BM stem cell niche.113525Ysciescopu
Simulation Study of Solar Wind Interaction with Lunar Magnetic Fields
Particle-in-cell simulations were performed to understand the interaction of the solar wind with localized magnetic fields on
the sunlit surface of the Moon. The results indicated a mini-magnetosphere was formed which had a thin magnetopause with
the thickness of the electron skin depth. It was also found that the solar wind penetrated into the cavity of the magnetosphere
intermittently rather than in a steady manner. The solar wind that moved around the magnetosphere was observed to hit the
surface of the Moon, implying that it may be the cause of the lunar swirl formation on the surface
Age-Related Changes in Egg Quality of Hy-Line Brown Hens
Abstract: The present study was conducted to monitor age-related changes in egg quality during the entire production cycle of laying hens. Thirty eggs were sampled from the commercial farm on a weekly basis for egg analysis. In order to increase in confidence in sampling, farm personnel were educated to collect the eggs from the pre-determined cages during the whole period and all layers were subjected to an identical farm management and fed a commercial layer diet. In total, 1,470 eggs were sampled and transported to the laboratory of Korea Institute for Animal Products Quality Evaluation. The parameters for egg quality included egg weight, eggshell color, eggshell breaking strength, eggshell thickness, Haugh unit and yolk color. It was shown that egg weight increased as the hen aged. Eggshell breaking strength gradually decreased, but eggshell thickness was randomly scattered without showing any age-related trends during the laying period. The intensity of eggshell color kept relatively constant while yolk color increased with age. Finally, Haugh unit as an indicator of freshness of eggs was consistently decreased as the hens aged. In this study, we noticed that eggshell breaking strength and egg weight were negatively correlated (r= -0.500, p<0.001). Eggshell color did not significantly correlate with eggshell thickness (r = -0.074, p>0.50), but marginally and positively correlated with egg weight (r = 0.248, p = 0.082). It is concluded that among the various egg quality parameters analyzed, egg weight, eggshell breaking strength or Haugh unit reduced as the hens aged. Further study is needed to include various parameters of egg quality such as chemical or nutritional composition which will provide more insight into the age-mediated changes in egg quality
Corrigendum: Suicide Rate Differences by Sex, Age, and Urbanicity, and Related Regional Factors in Korea
Etiologic and epidemiologic analysis of bacterial infectious upper respiratory disease in Thoroughbred horses at the Seoul Race Park
Infectious upper respiratory disease (IURD) of Thoroughbred racehorses has been a frequent problem (29.6% of incidence) at the Seoul Race Park (Korea). Risk factors for IURD include the season with a high transfer rate (summer and fall), the stabling period (≤ 3 months), and age (2 to 3 years old), suggesting that the movement and new environment may have depressed the immune system of the horses and decreased their ability to respond properly to pathogens. The bacterial strains (n = 98) isolated from IURD horses included Pseudomonas spp., Escherichia coli, Staphylococcus spp., Streptococcus equi subsp. equi and zooepidemicus
Indirect Band Gap in Scrolled MoS<sub>2</sub> Monolayers
MoS2 nanoscrolls that have inner core radii of ∼250 nm are generated from MoS2 monolayers, and the optical and transport band gaps of the nanoscrolls are investigated. Photoluminescence spectroscopy reveals that a MoS2 monolayer, originally a direct gap semiconductor (∼1.85 eV (optical)), changes into an indirect gap semiconductor (∼1.6 eV) upon scrolling. The size of the indirect gap for the MoS2 nanoscroll is larger than that of a MoS2 bilayer (∼1.54 eV), implying a weaker interlayer interaction between concentric layers of the MoS2 nanoscroll compared to Bernal-stacked MoS2 few-layers. Transport measurements on MoS2 nanoscrolls incorporated into ambipolar ionic-liquid-gated transistors yielded a band gap of ∼1.9 eV. The difference between the transport and optical gaps indicates an exciton binding energy of 0.3 eV for the MoS2 nanoscrolls. The rolling up of 2D atomic layers into nanoscrolls introduces a new type of quasi-1D nanostructure and provides another way to modify the band gap of 2D materials
Changing patterns of intimate partner violence against pregnant women: a three-year longitudinal study
Intimate partner violence (IPV) against pregnant women adversely impacts women’s and infants’ health. This study aims to provide longitudinal evidence regarding how pregnant women’s exposure to IPV changes over time. Additionally, we examine the risk and protective factors associated with these changes. In total, 340 pregnant women were recruited from an antenatal clinic in Hong Kong. IPV experiences and health conditions were assessed at pregnancy and at both 4 weeks and 3 years after childbirth. The women also reported adverse childhood experiences (ACEs), their family support, and perceived partner involvement. We found IPV prevalence among the study sample decreased from 22.9% before pregnancy to 13.5% during pregnancy, 14.7% at 4 weeks after childbirth, and 11.8% at 3 years after childbirth. We further found three types of IPV: 11.8% of women had a violent relationship (VR) persistently over time from pregnancy to 3 years after childbirth, 20.6% experienced decreased IPV (DVR), and 67.6% reported a nonviolent relationship (NVR) throughout the study period. VRs were associated with more severe mental health problems and higher ACEs. Family support and partner involvement may be protective factors for decreased IPV. Our present findings highlight the importance of identifying different IPV types over time to provide targeted intervention to the most vulnerable groups
Marked Individual Variation in Isoflavone Metabolism After a Soy Challenge Can Modulate the Skeletal Effect of Isoflavones in Premenopausal Women
Soy-isoflavones may act as estrogenic agonists or antagonists depending on the endogenous hormone status. These clinical effects can be exerted variably in individuals by the metabolic ability to produce a more potent metabolite than precursors. The objective of this randomized, double-blind, placebo-controlled study was to investigate the skeletal effect of isoflavones according to their metabolic variability in premenopausal women. Volunteers were randomly assigned to receive either soy-extract isoflavones (n=32) or lactose (n=21) once a day for three menstrual cycles. After intervention, the urinary excretions of isoflavones and their metabolites were significantly higher in the soy group than in the placebo group and showed a large inter-individual variation. Women in the soy group were divided into subgroups according to their ability to excrete more potent metabolites. Serum osteocalcin and urine deoxypyridinoline showed a tendency to increase after a challenge in equol high-excretors. Serum osteocalcin concentration in the genistein high-excretors increased significantly after a challenge (P=0.04) but did not increase in either the placebo or genistein low-excretors. An estrogenic antagonistic effect of isoflavones on bone turnover was observed in premenopausal women who are able to produce more potent metabolites
Maintenance of nitric oxide inhalation to a patient with hemoperitonium and acute respiratory distress syndrome during anesthesia -A case report-
Inhaled nitric oxide (NO) is occasionally used to treat hypoxemia for patients with acute respiratory distress syndrome (ARDS) in the intensive care unit (ICU). However, it is controversial whether or not to maintain inhalation of NO during general anesthesia because of complications, such as nitrogen dioxide (NO2) production, methemoglobinemia, and inhibition of platelet aggregation. In this case, a 67-year-old male fell from a roof and was brought to an emergency care center. During management, he vomited gastric contents and aspirated. In spite of tracheal intubation and mechanical ventilation with high oxygen therapy, the hypoxia did not improve. NO inhalation with mechanical ventilation was performed to treat hypoxemia due to ARDS in the ICU. We maintained the NO inhalation during the surgery for a hemoperitonium. The surgery was completed without intra-operative hemodynamic instability or any complications
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