High-performance Self-lubricating Ceramic Composites with Laminated-graded Structure

High-performance ceramic composites are potential candidates for the application of wear-resistance components because of their excellent properties. Nevertheless, many problems, such as high friction coefficient of ceramic material and poor mechanical properties of ceramic-matrix self-lubricating composites, limit a wider range of applications of these composites in tribological areas. Therefore, improving high-toughness ceramic-matrix self-lubricating materials for practical applications is significant. This study proposes a new design for ceramic self-lubricating composites to overcome the conflict between their mechanical and tribological properties. Complying with the design principle of bionic and graded composites, two kinds of self-lubricating ceramic composites with laminated-graded structure were prepared, and their mechanical and tribological properties were studied. The results show that this newly developed ceramic composite has achieved satisfactory strength and tribological properties compared with the traditional ceramic self-lubricating composites. The bending strength reached the same level as the properties of general monolithic ceramics. In the temperature range of 25-800 °C, the friction coefficient of composites was less than 0.55, which was about half of that of monolithic ceramics

Making Our Schools More Creative: Korea’s Efforts and Challenges

The Korean government has been interested in developing creativity in education and has attempted to increase the creativity of schools since the mid-1990s. This study aims to critically review the policy efforts of the Korean government for the last twenty years. To achieve this aim, the study analyzes government documents and related department website materials since mid-1990s when creativity emerged as a key agenda in Korean education policy. The results reveal that the government’s endeavors for achieving creativity include increasing flexibility in the national curriculum, developing teachers’ creativity by improving teacher education, and establishing supporting systems such as online information websites and teaching and learning materials. However, these efforts have been inadequate for an authentic transformation of schools. This study recommends that the government should emphasize creativity education through subject matter, support teacher-driven development of teaching materials, define student creativity as an ultimate goal of teacher creativity, and cultivate a co-operative and communicative school culture

Newly developed post-operative atrial fibrillation is associated with an increased risk of late recurrence of atrial fibrillation in patients who underwent open heart surgery: Long-term follow up

Background: Herein is sought to determine whether the occurrence of post-operative atrial fibrillation (POAF) increases the risk of late recurrence of atrial fibrillation (AF) in patients undergoing open heart surgery (OHS). Methods: This study included 938 patients (56.7 ± 13.1 years old, 550 males) with no history of AF who underwent OHS. All patients were monitored continuously for development of POAF after surgery until the time of hospital discharge and received clinical follow up with serial evaluation of rhythm status. Results: Among the total population, POAF occurred in 207 (22.1%) patients and late AF in 88 (9.4%) patients during the mean follow up period of 78.1 ± 39.1 months. Development of late AF oc¬curred more frequently in patients with POAF than in those without [29.0% (60/207) vs. 3.8% (28/731), p < 0.01]. Higher septal E/e’ ratio (HR 1.04, 95% CI 1.00–1.08, p = 0.04) was an independent predic¬tor of late occurrence of AF and an episode of POAF (HR 27.12, 95% CI 8.46–86.96, p < 0.01) was the most powerful predictor. Conclusions: POAF is significantly associated with an increased risk of late AF recurrence during long-term follow up. Careful concern regarding late recurrence of AF with serial evaluation of rhythm status is required in patients with POAF

Effective Locations for Injecting Botulinum Toxin into the Mentalis Muscle; Cadaveric and Ultrasonographic Study

The mentalis muscle is now considered key structures when performing procedures for rejuvenating the lower face. The aim of this study was to determine the anatomical morphology and location of the mentalis muscle and thereby provide anatomical information for facilitating clinical procedures designed to rejuvenate the lower face. Forty-four adult hemifaces from five Thai cadavers and 21 Korean cadavers were dissected to identify the locations of the mentalis muscle. Sixty-six hemifaces from 33 healthy young Korean subjects were included in an ultrasonographic study. The depth of the mentalis muscle below the skin surface, the thickness of the mentalis muscle, and the distance from the bone to the mentalis muscle were measured at the two points that were 5 mm lateral to the most-prominent point of the chin. The mentalis muscle was classified into two types based to its shape: in type A (86.4%, 38 of the 44 cases) it was dome shaped in three dimensions, while in type B (13.6%, 6 of the 44 cases) it was flat. The mentalis muscle was present mostly at the area 5–10 mm from the midsagittal line and 20–30 mm from a horizontal line connecting the mouth corners. The mentalis muscle was present between depths of 6.7 to 10.7 mm below the skin. This new information about the location of the mentalis muscle may help when identifying the most effective and safe botulinum toxin injection points and depths during esthetic procedures for weakened facial rhytides on the lower face

Effective Locations for Injecting Botulinum Toxin into the Mentalis Muscle; Cadaveric and Ultrasonographic Study

The mentalis muscle is now considered key structures when performing procedures for rejuvenating the lower face. The aim of this study was to determine the anatomical morphology and location of the mentalis muscle and thereby provide anatomical information for facilitating clinical procedures designed to rejuvenate the lower face. Forty-four adult hemifaces from five Thai cadavers and 21 Korean cadavers were dissected to identify the locations of the mentalis muscle. Sixty-six hemifaces from 33 healthy young Korean subjects were included in an ultrasonographic study. The depth of the mentalis muscle below the skin surface, the thickness of the mentalis muscle, and the distance from the bone to the mentalis muscle were measured at the two points that were 5 mm lateral to the most-prominent point of the chin. The mentalis muscle was classified into two types based to its shape: in type A (86.4%, 38 of the 44 cases) it was dome shaped in three dimensions, while in type B (13.6%, 6 of the 44 cases) it was flat. The mentalis muscle was present mostly at the area 5–10 mm from the midsagittal line and 20–30 mm from a horizontal line connecting the mouth corners. The mentalis muscle was present between depths of 6.7 to 10.7 mm below the skin. This new information about the location of the mentalis muscle may help when identifying the most effective and safe botulinum toxin injection points and depths during esthetic procedures for weakened facial rhytides on the lower face

Ectopic expression of human airway trypsin‐like protease 4 in acute myeloid leukemia promotes cancer cell invasion and tumor growth

Abstract Transmembrane serine proteases have been implicated in the development and progression of solid and hematological cancers. Human airway trypsin‐like protease 4 (HAT‐L4) is a transmembrane serine protease expressed in epithelial cells and exocrine glands. In the skin, HAT‐L4 is important for normal epidermal barrier function. Here, we report an unexpected finding of ectopic HAT‐L4 expression in neutrophils and monocytes from acute myeloid leukemia (AML) patients. Such expression was not detected in bone marrow cells from normal individuals or patients with chronic myeloid leukemia, acute lymphocytic leukemia and chronic lymphocytic leukemia. In AML patients who underwent chemotherapy, persistent HAT‐L4 expression in bone marrow cells was associated with minimal residual disease and poor prognostic outcomes. In culture, silencing HAT‐L4 expression in AML–derived THP‐1 cells by short hairpin RNAs inhibited matrix metalloproteinase‐2 activation and Matrigel invasion. In mouse xenograft models, inhibition of HAT‐L4 expression reduced the proliferation and growth of THP‐1 cell–derived tumors. Our results indicate that ectopic HAT‐L4 expression is a pathological mechanism in AML and that HAT‐L4 may be used as a cell surface marker for AML blast detection and targeting

Autism-related KLHL17 and SYNPO act in concert to control activity-dependent dendritic spine enlargement and the spine apparatus.

Dendritic spines, the tiny and actin-rich protrusions emerging from dendrites, are the subcellular locations of excitatory synapses in the mammalian brain that control synaptic activity and plasticity. Dendritic spines contain a specialized form of endoplasmic reticulum (ER), i.e., the spine apparatus, required for local calcium signaling and that is involved in regulating dendritic spine enlargement and synaptic plasticity. Many autism-linked genes have been shown to play critical roles in synaptic formation and plasticity. Among them, KLHL17 is known to control dendritic spine enlargement during development. As a brain-specific disease-associated gene, KLHL17 is expected to play a critical role in the brain, but it has not yet been well characterized. In this study, we report that KLHL17 expression in mice is strongly regulated by neuronal activity and KLHL17 modulates the synaptic distribution of synaptopodin (SYNPO), a marker of the spine apparatus. Both KLHL17 and SYNPO are F-actin-binding proteins linked to autism. SYNPO is known to maintain the structure of the spine apparatus in mature spines and contributes to synaptic plasticity. Our super-resolution imaging using expansion microscopy demonstrates that SYNPO is indeed embedded into the ER network of dendritic spines and that KLHL17 is closely adjacent to the ER/SYNPO complex. Using mouse genetic models, we further show that Klhl17 haploinsufficiency and knockout result in fewer dendritic spines containing ER clusters and an alteration of calcium events at dendritic spines. Accordingly, activity-dependent dendritic spine enlargement and neuronal activation (reflected by extracellular signal-regulated kinase (ERK) phosphorylation and C-FOS expression) are impaired. In addition, we show that the effect of disrupting the KLHL17 and SYNPO association is similar to the results of Klhl17 haploinsufficiency and knockout, further strengthening the evidence that KLHL17 and SYNPO act together to regulate synaptic plasticity. In conclusion, our findings unravel a role for KLHL17 in controlling synaptic plasticity via its regulation of SYNPO and synaptic ER clustering and imply that impaired synaptic plasticity contributes to the etiology of KLHL17-related disorders