In-plane deformation of a triangulated surface model with metric degrees of freedom

Using the canonical Monte Carlo simulation technique, we study a Regge calculus model on triangulated spherical surfaces. The discrete model is statistical mechanically defined with the variables $X$, $g$ and $\rho$, which denote the surface position in ${\bf R}^3$, the metric on a two-dimensional surface $M$ and the surface density of $M$, respectively. The metric $g$ is defined only by using the deficit angle of the triangles in {$M$}. This is in sharp contrast to the conventional Regge calculus model, where {$g$} depends only on the edge length of the triangles. We find that the discrete model in this paper undergoes a phase transition between the smooth spherical phase at $b to infty$ and the crumpled phase at $b to 0$, where $b$ is the bending rigidity. The transition is of first-order and identified with the one observed in the conventional model without the variables $g$ and $\rho$. This implies that the shape transformation transition is not influenced by the metric degrees of freedom. It is also found that the model undergoes a continuous transition of in-plane deformation. This continuous transition is reflected in almost discontinuous changes of the surface area of $M$ and that of $X(M)$, where the surface area of $M$ is conjugate to the density variable $\rho$.Comment: 13 pages, 7 figure

Phase segregated Cu₂₋ₓSe/Ni₃Se₄ bimetallic selenide nanocrystals formed through the cation exchange reaction for active water oxidation precatalysts

Control over the composition and nanostructure of solid electrocatalysts is quite important for drastic improvement of their performance. The cation exchange reaction of nanocrystals (NCs) has been reported as the way to provide metastable crystal structures and complicated functional nanostructures that are not accessible by conventional synthetic methods. Herein we demonstrate the cation exchange-derived formation of metastable spinel Ni₃Se₄NCs (sp-Ni₃Se₄) and phase segregated berzelianite Cu₂₋ₓSe (ber-Cu₂₋ₓSe)/sp-Ni₃Se₄ heterostructured NCs as active oxygen evolution reaction (OER) catalysts. A rare sp-Ni₃Se₄ phase was formed by cation exchange of ber-Cu₂₋ₓSe NCs with Ni²⁺ ions, because both phases have the face-centered cubic (fcc) Se anion sublattice. Tuning the Ni : Cu molar ratio leads to the formation of Janus-type ber-Cu₂₋ₓSe/sp-Ni₃Se₄ heterostructured NCs. The NCs of sp-Ni₃Se₄ and ber-Cu₂₋ₓSe/sp-Ni₃Se₄ heterostructures exhibited high catalytic activities in the OER with small overpotentials of 250 and 230 mV at 10 mA cm⁻² in 0.1 M KOH, respectively. They were electrochemically oxidized during the OER to give hydroxides as the real active species. We anticipate that the cation exchange reaction could have enormous potential for the creation of novel heterostructured NCs showing superior catalytic performance

Method for Identifying Type of Eddy-Current Displacement Sensor

Eddy-current (EC) displacement sensors are used in a device for measuring the shaft vibration of turbines. An EC displacement sensor is composed of a sensor probe and an impedance/output voltage (Z/V) converter. In a power plant in the U. S., the type of the sensor probe and the displacement from the turbine shaft to the tip of the sensor probe (displacement x) are not controlled. For this reason, when only the Z/V converter breaks down, the plant is stopped and dismantled, and both the Z/V converter and the sensor probe are replaced. This results in two problems, i.e., the unstable supply of electric power when the power plant is stopped and the high cost of dismantling the plant. If both the type of the sensor probe and x are identified during turbine operation, the aforementioned problems could be solved. In this paper, we describe that the three types of the sensor probe and x can be identified by comparing the measured the maximum quality factor Q(EC) (max) and frequency f(o) at Q(EC) (max) with the Q(EC) (max) versus f(o) characteristics of sensor probes.ArticleIEEE TRANSACTIONS ON MAGNETICS. 47(10):3554-3557 (2011)journal articl

Calcium-binding analysis and molecular modeling reveal echis coagulation factor IX/factor X-binding protein has the Ca-binding properties and Ca ion-independent folding of other C-type lectin-like proteins

Abstract Many biologically active heterodimeric proteins of snake venom consist of two C-type lectin-like subunits. One of these proteins, habu IX/X-bp, is a Gla domain-binding protein whose subunits both bind to a Ca 2+ ion, with a total of two Ca 2+ -binding sites. The molecular modeling and Ca 2+ -binding analysis of echis IX/X-bp revealed that it lacks one of two Ca 2+ -binding sites, though the folding of this subunit is conserved. It is concluded that heterodimeric C-type lectin-like proteins function independent of Ca 2+ and have essentially a similar folding to habu IX/X-bp

Migration arrest of chemoresistant leukemia cells mediated by MRTF-SRF pathway

Background: Dormant chemotherapy-resistant leukemia cells can survive for an extended period before relapse. Nevertheless, the mechanisms underlying the development of chemoresistance in vivo remain unclear. Methods: Using intravital bone imaging, we characterized the behavior of murine acute myeloid leukemia (AML) cells (C1498) in the bone marrow before and after chemotherapy with cytarabine. Results: Proliferative C1498 cells exhibited high motility in the bone marrow. Cytarabine treatment impaired the motility of residual C1498 cells. However, C1498 cells regained their migration potential after relapse. RNA sequencing revealed that cytarabine treatment promoted MRTF-SRF pathway activation. MRTF inhibition using CCG-203971 augmented the anti-tumor effects of chemotherapy in our AML mouse model, as well as suppressed the migration of chemoresistant C1498 cells. Conclusions: These results provide novel insight into the role of cell migration arrest on the development of chemoresistance in AML, as well as provide a strong rationale for the modulation of cellular motility as a therapeutic target for refractory AML.Morimatsu M., Yamashita E., Seno S., et al. Migration arrest of chemoresistant leukemia cells mediated by MRTF-SRF pathway. Inflammation and Regeneration 40, 15 (2020); https://doi.org/10.1186/s41232-020-00127-6

Thrombomodulin induces anti-inflammatory effects by inhibiting the rolling adhesion of leukocytes in vivo

Thrombomodulin (TM) is an integral membrane protein expressed on the surface of vascular endothelial cells that suppresses blood coagulation. Recent studies have shown that TM exhibits anti-inflammatory effects by inhibiting leukocyte recruitment. However, the actual modes of action of TM in vivo remain unclear. Here, we describe the pharmacological effects of recombinant human soluble TM (TM alfa) on leukocyte dynamics in living mice using intravital imaging techniques. Under control conditions, neutrophils exhibited three distinct types of adhesion behavior in vessels: 1) “non-adhesion”, in which cells flowed without vessel adhesion; 2) “rolling adhesion”, in which cells transiently interacted with the endothelium; and 3) “tight binding”, in which cells bound strongly to the endothelial cells. Compared to control conditions, local lipopolysaccharide stimulation resulted in an increased frequency of rolling adhesion that was not homogeneously distributed on vessel walls but occurred at specific endothelial sites. Under inflammatory conditions, TM alfa, particularly the D1 domain which is a lectin-like region of TM, significantly decreased the frequency of rolling adhesion, but did not influence the number of tight bindings. This was the first study to demonstrate that TM alfa exerts anti-inflammatory effects by inhibiting rolling adhesion of neutrophils to vascular endothelial cells in living mice.Nishizawa S., Kikuta J., Seno S., et al. Thrombomodulin induces anti-inflammatory effects by inhibiting the rolling adhesion of leukocytes in vivo. Journal of Pharmacological Sciences 143, 17 (2020); https://doi.org/10.1016/j.jphs.2020.01.001

Idiopathic multicentric Castleman disease with positive antiphospholipid antibody: atypical and undiagnosed autoimmune disease?

Idiopathic multicentric Castleman disease (iMCD) is a systemic disorder characterized by systemic inflammation and organ dysfunction associated with an increase in pro-inflammatory cytokines. Some patients with iMCD are positive for autoantibodies, although their significance and relationship with specific associated autoimmune diseases are unclear. This study retrospectively analyzed the clinicopathological features of iMCD patients focusing on autoantibodies. Among 63 iMCD patients in our database, 19 were positive for at least one autoantibody. Among the 19, we identified five with plasma cell type (PC)-iMCD lymph node histopathology and positive anti-phospholipid antibodies. These patients were likely to have thrombocytopenia, anasarca, fever, reticulin fibrosis or renal insufficiency, organomegaly (TAFRO) symptoms, and thrombotic events. The present study suggests that patients with undiagnosed or atypical autoimmune diseases, including anti-phospholipid syndrome (APS), were treated for iMCD. APS may present with thrombocytopenia or even multi-organ failure, which overlap with clinical presentations of iMCD. Due to differences in the treatment regimen and follow-up, recognition of the undiagnosed autoimmune disease process in those suspected of iMCD is essential. Our study highlights the importance of complete exclusion of differential diagnoses in patients with iMCD in their diagnostic workup

Real-time In Situ Electron Spin Resonance Measurements on Fungal Spores of Penicillium digitatum during Exposure of Oxygen Plasmas

We report the kinetic analysis of free radicals on fungal spores of Penicillium digitatum interacted with atomic oxygen generated plasma electric discharge using real time in situ electron spin resonance (ESR) measurements. We have obtained information that the ESR signal from the spores was observed and preliminarily assignable to semiquinone radical with a g-value of around 2.004 and a line width of approximately 5G. The decay of the signal is possibly linked to the inactivation of the fungal spore. The real-time in situ ESR has proven to be a useful method to elucidate plasma-induced surface reactions on biological specimens.Comment: 11 pages, 5 figure