13,356 research outputs found
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Laser Sintering of Stainless Steel using Resin Powder
We tried laser sintering of 316L stainless steel powder using resin powder. The laser
sintering conditions such as laser power, scan speed and scan pitch with a YAG laser, and the
influence of additional resin powder on the density and the tensile properties of the sintered alloy
were investigated experimentally. The tensile specimen was laser-sintered with a YAG laser, and
then debound and sintered in a vacuum furnace. The tensile specimen was successfully fabricated.
The relative density and the tensile strength varied with the additional resin powder, and the
optimum weight percentage of additional resin powder was around 4%.The relative density of the
sintered alloy was approximately 85%, and the tensile strength and elongation of the sintered
alloy were more than 280 MPa and 15% respectively.Mechanical Engineerin
Local Spin Susceptibility of the S=1/2 Kagome Lattice in ZnCu3(OD)6Cl2
We report single-crystal 2-D NMR investigation of the nearly ideal spin S=1/2
kagome lattice ZnCu3(OD)6Cl2. We successfully identify 2-D NMR signals
originating from the nearest-neighbors of Cu2+ defects occupying Zn sites. From
the 2-D Knight shift measurements, we demonstrate that weakly interacting Cu2+
spins at these defects cause the large Curie-Weiss enhancement toward T=0
commonly observed in the bulk susceptibility data. We estimate the intrinsic
spin susceptibility of the kagome planes by subtracting defect contributions,
and explore several scenarios.Comment: 4 figures; published in PR-B Rapid Communication
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A homing receptor-IgG chimera as a probe for adhesive ligands of lymph node high endothelial venules.
The binding of lymphocytes to high endothelial venules (HEV) within peripheral lymph nodes (pln) is thought to be mediated by a lectinlike adhesion molecule termed the pln homing receptor (pln HR). The cloning and sequencing of cDNAs encoding both murine and human pln HR revealed that these adhesion molecules contain protein motifs that are homologous to C-type or calcium dependent lectin domains as well as to epidermal growth factor (egf) and complement-regulatory protein domains. We have produced a novel, antibody-like form of the murine HR by joining the extracellular region of the receptor to a human IgG heavy chain. This antibody-like molecule is capable of recognizing carbohydrates, blocking the binding of lymphocytes to pln HEV, and serving as a histochemical reagent for the staining of pln HEV. This murine HR-IgG chimera should prove useful in analyzing the distribution of the HR ligand(s) in normal as well as in inflammatory states
Particle based modeling and simulation of the red blood cell Infected by malaria-mechanism of the margination of the Infected red blood cell
This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute.Motion and distribution of red blood cells in blood microvessels depend on vessel diameter, hematocrit (Hct), RBCs deformability and other factors. Migration of deformable red blood cells (RBCs) to
the center of microvessels and away from the wall leads to the formation of cell-free layer (CFL). Few experiments or simulations considered the effects of motion and interaction of RBCs on CFL thickness. We
employ a meshless (particle) method to model microvascular blood flow. An efficient parallel algorithm is developed for large-scale simulations of blood flow in microvessels. Using the developed method, we
analyze the change in RBCs shape and RBCs distribution and also thickness of CFL in a variety of vessel sizes and Hct conditions. The results indicate that the CFL thickness increases when the vessel size increases
or Hct decreases, which is in good agreement with previous experimental results. We also show change on RBCs shape and distribution for different microvessels diameter and Hct conditions
The complement binding-like domains of the murine homing receptor facilitate lectin activity.
The leukocyte homing receptor (HR), the endothelial leukocyte adhesion molecule, and gmp140/platelet activation-dependent granule membrane protein are members of a family of adhesion molecules, termed the lectin cell adhesion molecules (LEC-CAMS) which are unified by a multi-domain structure containing a lectin motif, an epidermal growth factor-like (egf) motif, and variable numbers of a complement binding-like (CB) motif. Previous data have indicated a predominant role for the lectin motif in cell adhesion directed by the LEC-CAMS, although the egf-like domain of the HR may also play a potential role in cell binding. While the role(s) of the CB domains in the LEC-CAMS is currently not understood, they have been hypothesized to act as rigid spacers or stalks for lectin and perhaps, egf domain presentation. In this paper, we analyze the functional characteristics of murine HR-IgG chimeras containing the lectin, lectin plus egf, and lectin plus egf plus CB domains. The Mel 14 mAb, an adhesion blocking antibody which recognizes a conformational determinant in the N-terminus of the HR lectin domain, shows a significantly decreased affinity for a HR construct which lacks the CB motifs, consistent with the possibility that the CB domains are involved with lectin domain structure. In agreement with this conjecture, HR mutants lacking the CB domains show a profound decrease in lectin-specific interaction with the carbohydrate polyphosphomannan ester, suggesting that the changes in Mel 14 affinity for the lectin domain are reflected in lectin functionality. Various assays investigating the interactions between the HR deletion mutants and the peripheral lymph node high endothelium, including cell blocking, immunohistochemical staining, and radioactively labeled ligand binding, all showed that removal of the CB domains results in a lack of HR adhesive function. These results imply that the CB domains of the HR, and, by analogy, the other members of the LEC-CAM family, may play important structural roles involving induction of lectin domain conformation and resultant functionality
Towards Identifying and closing Gaps in Assurance of autonomous Road vehicleS - a collection of Technical Notes Part 1
This report provides an introduction and overview of the Technical Topic Notes (TTNs) produced in the Towards Identifying and closing Gaps in Assurance of autonomous Road vehicleS (Tigars) project. These notes aim to support the development and evaluation of autonomous vehicles. Part 1 addresses: Assurance-overview and issues, Resilience and Safety Requirements, Open Systems Perspective and Formal Verification and Static Analysis of ML Systems. Part 2: Simulation and Dynamic Testing, Defence in Depth and Diversity, Security-Informed Safety Analysis, Standards and Guidelines
Identification of a carbohydrate-based endothelial ligand for a lymphocyte homing receptor.
Lymphocyte attachment to high endothelial venules within lymph nodes is mediated by the peripheral lymph node homing receptor (pnHR), originally defined on mouse lymphocytes by the MEL-14 mAb. The pnHR is a calcium-dependent lectin-like receptor, a member of the LEC-CAM family of adhesion proteins. Here, using a soluble recombinant form of the homing receptor, we have identified an endothelial ligand for the pnHR as an approximately 50-kD sulfated, fucosylated, and sialylated glycoprotein, which we designate Sgp50 (sulfated glycoprotein of 50 kD). Recombinant receptor binding to this lymph node-specific glycoprotein requires calcium and is inhibitable by specific carbohydrates and by MEL-14 mAb. Sialylation of the component is required for binding. Additionally, the glycoprotein is precipitated by MECA-79, an adhesion-blocking mAb reactive with lymph node HEV. A related glycoprotein of approximately 90 kD (designated as Sgp90) is also identified
Detections of SiO Masers from the Large-Amplitude Variables in the Galactic Nuclear Disk
We have surveyed known large-amplitude variables within 15' of the Galactic
center in the SiO J=1-0 v=1 and 2 maser lines at 43 GHz, resulting in 79
detections and 58 non-detections. The detection rate of 58 percent is
comparable to that obtained in Bulge IRAS source surveys. SiO lines were also
detected from four other sources near the program objects. The SiO detection
rate increases steeply with the period, particularly for stars with P>500 d,
where it exceeds 80%. We found at a given period that the SiO detection rate is
approximately double that for OH. These facts suggest that the large-amplitude
variables in the Nuclear Disk region are AGB stars similar in their overall
properties to the inner and outer bulge IRAS/SiO sources.Comment: 5 pages, 2 figures, 1 Table. PASJ 54, No 2 April 25 issue in pres
Precise Pressure Dependence of the Superconducting Transition Temperature of FeSe: Resistivity and ^77Se--NMR Study
We report the precise pressure dependence of FeSe from a resistivity
measurement up to 4.15 GPa. Superconducting transition temperature (T_c)
increases sensitively under pressure, but shows a plateau between 0.5-1.5 GPa.
The maximum T_c, which is determined by zero resistance, is 21 K at
approximately 3.5 GPa. The onset value reaches ~37 K at 4.15 GPa. We also
measure the nuclear spin-lattice relaxation rate 1/T_1 under pressure using
77Se--NMR measurement. 1/T_1 shows that bulk superconductivity is realized in
the zero-resistance state. The pressure dependence of 1/T_1T just above T_c
shows a plateau as well as the pressure dependence of T_c, which gives clear
evidence of the close relationship between 1/T_1T and T_c. Spin fluctuations
are suggested to contribute to the mechanism of superconductivity.Comment: 4pages, 6figures: to be published in J. Phys. Soc. Jpn. Vol.78 No.6
(2009
RadioAstron probes the ultra-fine spatial structure in the HO maser emission in the star forming region W49N
HO maser emission associated with the massive star formation region W49N
were observed with the Space-VLBI mission RadioAstron. The procedure for
processing of the maser spectral line data obtained in the RadioAstron
observations is described. Ultra-fine spatial structures in the maser emission
were detected on space-ground baselines of up to 9.6 Earth diameters. The
correlated flux densities of these features range from 0.1% to 0.6% of the
total flux density. These low values of correlated flux density are probably
due to turbulence either in the maser itself or in the interstellar medium.Comment: Accepted for publication in Advances in Space Researc
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