Modeling the electromagnetic cavity mode contributions to the THz emission from triangular Bi2Sr2CaCu2O8+δ mesas

In order to understand the radiation observed from the intrinsic Josephson junctions in triangular Bi2Sr2CaCu2O8+δ mesas, we calculate the transverse magnetic (TM) electromagnetic modes for thin equilateral cavities. A new set of distinct but degenerate TM modes coexists with the known modes of Helszajn and James, but are expected to lead to distinct radiation angular distribution patterns. Although we have been unable to solve for the exact TM modes of a thin cavity of general acute isosceles triangular shape, we solved exactly the closely related problems of the TM cavity modes of two thin circumscribing “pie-shaped” wedges, which provide highly accurate approximations to very acute isosceles triangular cavities.The 8th International Symposium on Intrinsic Josephson Effects and Plasma Oscillations in High-Tc Superconductors (PLASMA 2012

Monte Carlo Radiation Transport Modelling of the Current-Biased Kinetic Inductance Detector

Radiation transport simulations were used to analyse neutron imaging with the current-biased kinetic inductance detector (CB-KID). The PHITS Monte Carlo code was applied for simulating neutron, $^{4}$He, $^{7}$Li, photon and electron transport, $^{10}$B(n,$\alpha$)$^{7}$Li reactions, and energy deposition by particles within CB-KID. Slight blurring in simulated CB-KID images originated $^{4}$He and $^{7}$Li ions spreading out in random directions from the $^{10}$B conversion layer in the detector prior to causing signals in the $X$ and $Y$ superconducting Nb nanowire meander lines. 478 keV prompt gamma rays emitted by $^{7}$Li nuclei from neutron-$^{10}$B reactions had negligible contribution to the simulated CB-KID images. Simulated neutron images of $^{10}$B dot arrays indicate that sub 10 $\mu$m resolution imaging should be feasible with the current CB-KID design. The effect of the geometrical structure of CB-KID on the intrinsic detection efficiency was calculated from the simulations. An analytical equation was then developed to approximate this contribution to the detection efficiency. Detection efficiencies calculated in this study are upper bounds for the reality as the effects of detector temperature, the bias current, signal processing and dead-time losses were not taken into account. The modelling strategies employed in this study could be used to evaluate modifications to the CB-KID design prior to actual fabrication and testing, conveying a time and cost saving.Comment: 23 pages, 7 figures, Author Accepted Manuscript (8th Nov 2019), Nuclear Instruments and Methods in Physics Research

Public health expenditure, governance and health outcomes in Malaysia

According to the World Health Organization (WHO), government plays a crucial role in providing quality life for its citizens through good health system. There has been less attention given in analysing the relationship between government expenditure, governance and health outcomes particularly in developing countries. This paper aims to study the impact of public health expenditure and governance on health outcomes in Malaysia. An Autoregressive Distributed Lag (ARDL) cointegration framework has been used to analyse data from 1984 to 2009. The results based on the bounds testing procedure show that a stable, long-run relationship exists between health outcomes and their determinants; namely income level, public health expenditure, corruption and government stability. The results also reveal that public health expenditure and corruption affect long- and short run health outcomes in Malaysia. The findings are important to the policy makers in making decisions to improve the citizens’ quality of life. We suggest the Ministry of Health of Malaysia to conduct more consultations with other ministries and other stakeholders in health services as to identify the needs and emphasize on the importance of health program to the society. At the same time, attention should be given to reduce or eliminate the corruption rate as it has adverse effects on the country

Effect of current waveform in MIG arc on weld bead formation in plasma-MIG hybrid welding

The version of record of this article, first published in International Journal of Advanced Manufacturing Technology, is available online at Publisher’s website: https://doi.org/10.1007/s00170-024-13684-8.Plasma-metal inert gas (MIG) hybrid welding enables to join thick steel plates in single pass. However, arc coupling occurring between the plasma and MIG arcs disturbs its heat source characteristics, lowering the welding quality. This arc coupling phenomenon is not yet understood due to the complexity. This study aims to clarify the effect of current waveform of arc on weld bead formation according to the arc coupling in plasma-MIG hybrid welding. The metal transfer characteristics and bottom side weld pool were observed for direct current (DC) and pulse-MIG current waveforms. In addition, Ni element was used for visualizing the transport process of high-temperature molten metal provided by MIG welding within the weld pool. From these results, the effects of differences in MIG arc current waveforms on heat and mass transport processes within the weld pool and also on weld bead formation on the bottom side through changes in the occurrence of arc coupling were discussed. As a result, it was clarified that the droplets after detachment from the wire were transferred to the weld pool surface under the wire tip for DC MIG current, while those were transferred along the wire axis to the weld pool surface behind the keyhole for pulse-MIG current. When the droplet was transferred to the weld pool region with the forward flow such as the pulse-MIG current case, the heat was transported to the bottom side together with the counter-clockwise eddy behind the keyhole, strongly contributing to increasing the penetration depth. In the case of pulse-MIG current, the plasma arc is oscillated due to the arc coupling. According to this oscillation, the accumulation of molten metal behind the keyhole is prevented to suppress the humping bead formation. Consequently, pulse-MIG current was found to be suitable for increasing the penetration depth and suppressing humping bead formation on the bottom side comparing with DC MIG current

Temperature-dependent Specific Transport of Levofloxacin in Human Intestinal Epithelial LS180 Cells

It was reported previously that specific levofloxacin uptake in Caco- 2 cells was inhibited by nicotine, enalapril, L-carnitine and fexofenadine. The aim of the present study was to characterize the cellular uptake of levofloxacin using another human intestinal cell, line, LS180. Levofloxacin uptake in LS180 cells was temperature-dependent and optimal at neutral pH, but was Na+-independent. The rank order of inhibitory effects of the four compoundson[14C]levofloxacin uptake in LS180 cells was nicotine>enalapril> L- carnitine> fexofenadine, which is consistent with that in Caco- 2 cells. The mRNA levels of OATP1A2, 1B1, 1B3 and 2B1 in LS180 cells were markedly different from those in Caco-2 cells, and OATP substrates/inhibitors had no systematic effect on thelevofloxacin uptake.The mRNA levels of OCTN1 and 2 in LS180 cells were similar to those inCaco-2 cells.However, the inhibitory effect of nicotine on L-[3H]carnitine uptake was much less potent than that of unlabeled L-carnitine. These results in dicate that the specific uptake system for levofloxacin in LS180 cells isidentical/similar to that in Caco-2 cells, but that OATPs and OCTNs contribute little to levofloxacin uptake in the human intestinal epithelial cells.othe

Case Study: Somatic Sprouts and Halo-Like Amorphous Materials of the Purkinje Cells in Huntington’s Disease

We described a 63-year-old Japanese female with genetically confirmed Huntington’s disease who showed unusual pathological findings in the cerebellum. This case exhibited typical neuropathological features as Huntington’s disease, including severe degeneration of the neostriatum and widespread occurrence of ubiquitin and expanded polyglutamine-positive neuronal intranuclear and intracytoplasmic inclusions. The cerebellum was macroscopically unremarkable; however, somatic sprouts and halo-like amorphous materials of Purkinje cell with a large amount of torpedoes were noteworthy. Furthermore, the Purkinje cells were found to have granular cytoplasmic inclusions. Somatic sprouting is a form of degenerated Purkinje cell exhibited in several specific conditions. Although this finding usually appeared in developmental brains, several neurodegenerative disorders, including Menkes kinky hair disease, familial spinocerebellar ataxia, acute encephalopathy linked to familial hemiplegic migraine, and several other conditions, have been reported showing sprouting from the soma of Purkinje cell. We propose that Huntington’s disease is another degenerative condition associated with these distinct neuropathological findings of Purkinje cell. Abnormally accumulated huntingtin protein in the cytoplasm could be related to the development of these structures. © 2015 Springer Science+Business Media New YorkIn Pres

Severe Hypomyelination and Developmental Defects Are Caused in Mice Lacking Protein Arginine Methyltransferase 1 (PRMT1) in the Central Nervous System

Protein arginine methyltransferase 1 (PRMT1) is involved in cell proliferation, DNA damage response, and transcriptional regulation. While PRMT1 is extensively expressed in the central nervous system (CNS) at embryonic and perinatal stages, the physiological role of PRMT1 was poorly understood. Here, to investigate the primary function of PRMT1 in the CNS, we generated CNS-specific PRMT1 knockout mice by Cre-loxP system. These mice exhibited post-natal growth retardation with tremors and most of them died in two weeks after birth. Brain histological analyses revealed the prominent cell reduction in the white matter tracts of the mutant mice. Furthermore, ultrastructural analysis demonstrated that myelin sheath was almost completely ablated in the CNS of these animals. In agreement with hypomyelination, we also observed that most major myelin proteins including MBP, CNPase, and MAG were dramatically decreased, although neuronal and astrocytic markers were preserved in the brain of CNS-specific PRMT1 knockout mice. These animals had reduced number of OLIG2+ oligodendrocyte lineage cells in the white matter. We found that expressions of transcription factors essential for oligodendrocyte specification and further maturation were significantly suppressed in the brain of the mutant mice. Our findings provide evidence that PRMT1 is required for CNS development, especially for oligodendrocyte maturation processes