Compartmentalized, multiphasic nanocolloids with potential applications in drug delivery and biomedical imaging

Nanoparticles are excellent candidates for drug delivery or biomedical imaging, because they often exhibit superb tuneability of critical properties, such as size, surface characteristics, degradation rate, and therefore drug release rates. We have recently developed a route towards fabrication of sub-micron particles that relies on electrohydrodynamic co-jetting. In this process, fluid manipulation in an electrical field is used to fabricate large quantities of multi-compartment particles, where individual compartments can be independently loaded with different drugs or selectively surface-modified. In this contribution, aspects of multifunctional particles for biomedical applications are reviewed and a specific focus is given to recent progress with compartmentalized, multiphasic nanocolloids in our laboratory.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/57529/1/1008_ftp.pd

Nuclear mass table in density functional approach inspired by neutron-star observations

Background: Nuclear energy-density functional (EDF) approach has been widely used to describe nuclear-matter equations of state (EoS) and properties of finite nuclei. Recent advancements in neutron-star (NS) observations have put constraints on the nuclear EoS. The Korea-IBS-Daegu-SKKU (KIDS) functional has been then developed to satisfy the NS observations and applied to homogeneous nuclear matter and spherical nuclei. Purpose: We examine the performance of the KIDS functional by calculating the masses and charge radii of even-even nuclei towards the drip lines. Method: The Kohn-Sham-Bogoliubov equation is solved by taking into account the axial deformation. Results: The root-mean-square deviation of the binding energy and the charge radius for the KIDS functional is 4.5--5.1 MeV and 0.03--0.04 fm, which is comparable to that for existing EDFs. The emergence and development of nuclear deformation in open-shell nuclei are well described. The location of the neutron drip line is according to the nuclear-matter parameter characterizing the low-mass NS. Conclusions: The NS-observation-inspired EDF offers a reasonable reproduction of the structures of finite nuclei. A future global optimization including more nuclear data will give better accuracy and high predictive power of neutron-rich nuclei.Comment: 9 pages, 6 figures, and 2 table

Influences of small-scale oscillations on growth inhibition and ultrastructural changes of Microcystis cells

We investigated the effects of small-scale oscillation (SSO) on toxic Microcystis cells. The oscillating device was made of silicon with two axes that had a diameter of similar to 40 mm, and a frequency of 2.5 Hz was observed at 150 rpm. The SSO was effective in inhibiting Microcystis growth. Microcystin release was not observed, whereas cell density barely increased in the oscillating group. Cell size and morphology of the oscillating group were no different from the control group. However, cell quotas of chl.a and microcystin in the oscillating group were half the level of the control group. Crucially, a number of large-sized holes were observed and layered long linear thylakoids were rarely observed in the oscillating group. Therefore, SSO was found to be very effective in Microcystis growth inhibition, and it caused ultrastructural changes without damage to the cell membrane and subsequent microcystin release.ArticleJournal of Environmental Science and Health, Part A.53(13):1161-1166(2018)journal articl

Kinematics and excitation of the ram pressure stripped ionized gas filaments in the Coma cluster of galaxies

We present the results of deep imaging and spectroscopic observations of very extended ionized gas (EIG) around four member galaxies of the Coma cluster of galaxies: RB199, IC4040, GMP2923 and GMP3071. The EIGs were serendipitously found in an H-alpha narrow band imaging survey of the central region of the Coma cluster. The relative radial velocities of the EIGs with respect to the systemic velocities of the parent galaxies from which they emanate increase almost monotonically with the distance from the nucleus of the respective galaxies, reaching -400 - -800 km/s at around 40 - 80 kpc from the galaxies. The one-sided morphologies and the velocity fields of the EIGs are consistent with the predictions of numerical simulations of ram pressure stripping. We found a very low-velocity filament (v_rel = -1300 km/s) at the southeastern edge of the disk of IC4040. Some bright compact knots in the EIGs of RB199 and IC4040 exhibit blue continuum and strong H-alpha emission. The equivalent widths of the H-alpha emission exceed 200 A, and are greater than 1000 A for some knots. The emission line intensity ratios of the knots are basically consistent with those of sub-solar abundance HII regions. These facts indicate that intensive star formation occurs in the knots. Some filaments, including the low velocity filament of the IC4040 EIG, exhibit shock-like emission line spectra, suggesting that shock heating plays an important role in ionization and excitation of the EIGs.Comment: Accepted for publication in The Astrophysical Journal. 14 pages, 23 figures, emulateapj forma

String Junction Transitions in the Moduli Space of N=2 SYM

The string theory description of BPS states in D-brane world-volume field theories may undergo transitions from open strings to string webs, as well as between different string webs, as one moves in the field theory moduli space. These transitions are driven by the string creation phenomenon. We demonstrate such transitions in the D3-brane realization of N=2 SU(2) Super-Yang-Mills theory.Comment: 15 pages LaTex, 10 eps figure

The Jeju Weasel, Mustela sibilica quelpartis, A New Definitive Host for Gnathostoma nipponicum Yamaguti, 1941

Adult gnathostomes were discovered in the stomach of the Jeju weasel, Mustela sibilica quelpartis, road-killed in Jeju-do (Province). Their morphological characters were examined to identify the species. Total 50 gnathostome adults were collected from 6 out of 10 weasels examined. In infected weasels, 4-6 worms were grouped and embedded in each granulomatous gastric tumor, except 1 weasel. Male worms were 25.0×1.4 mm in average size, and had a tail with pedunculate papillae, a spicule, and minute tegumental spines. Females were 40.0×2.5 mm in average size, and had a tail without tegumental spines. Pointed and posteriorly curved hooklets were arranged in 8-10 rows on the head bulb. Tegumental spines were distributed from behind the head bulb to the middle portion of the body. The spines were different in size and shape by the distribution level of the body surface. Fertilized eggs were 65.5×38.9 µm in average size, and had a mucoid plug at 1 pole. These gnathostomes from Jeju weasels were identified as Gnathostoma nipponicum Yamaguti, 1941. By the present study, it was confirmed for the first time that G. nipponicum is distributed in Jeju-do, the Republic of Korea, and the Jeju weasel, M. sibilica quelpartis, plays a crucial role for its definitive host

XMM-Newton observations expose AGN in apparently normal galaxies

We have performed a detailed analysis of 3 optically normal galaxies extracted from the XMM Bright Serendipitous Source Sample. Thanks to the good statistics of the XMM-Newton data, we have unveiled the presence of an AGN in all of them. In particular, we detect both X-ray obscured (N_H>10^{22} cm^{-2}) and unobscured (N_H<10^{22} cm^{-2}) AGN with intrinsic 2--10 keV luminosities in the range between 10^{42} -- 10^{43} erg s^{-1}. We find that the X-ray and optical properties of the sources discussed here could be explained assuming a standard AGN hosted by galaxies with magnitudes M_R<M^*, taking properly into account the absorption associated with the AGN, the optical faintness of the nuclear emission with respect to the host galaxy, and the inadequate set--up and atmospheric conditions during the optical spectroscopic observations. Our new spectroscopic observations have revealed the expected AGN features also in the optical band. These results clearly show that optical spectroscopy sometimes can be inefficient in revealing the presence of an AGN, which instead is clearly found from an X-ray spectroscopic investigation. This remarks the importance of being careful in proposing the identification of X-ray sources (especially at faint fluxes) when only low quality optical spectra are in hand. This is particularly important for faint surveys (such as those with XMM-Newton and Chandra), in which optically dull but X-ray active objects are being found in sizeable numbers.Comment: Accepted for publication on A&A; 11 pages, 8 figure

Secular Instability of g-Modes in Rotating Neutron Stars

Gravitational radiation tends to drive gravity modes in rotating neutron stars unstable. For an inviscid star, the instability sets in when the rotation frequency is about 0.7 times the corresponding mode frequency of the nonrotating star. Neutron stars with spin frequencies \go 100 Hz are susceptible to this instability, with growth time of order years. However, it is likely that viscous dissipation suppresses the instability except for a narrow range of temperatures around $10^9$ K. We also show that the viscosity driven instability of g-modes is absent.Comment: 8 pages, 5 figures; MNRAS, in press. 2 figures added; More details are given for the mode propertie

R-modes of a neutron star with a magnetic dipole field

We study $r$-modes of a rotating magnetized neutron star, assuming a magnetic dipole field whose axis is aligned with the axis of rotation. We approach the problem by applying a singular perturbation theory to the oscillations of rotating stars. In this treatment, we divide the star into a thin surface magnetic layer and a non-magnetic core. We integrate linearized ideal MHD equations in the surface magnetic layer and non-magnetic oscillation equations in the core, and match the two integrations at the interface to obtain a complete solution. For a polytropic neutron star model of mass $M=1.4M_\odot$ and radius $R=10^6$cm, the magnetic dipole field becomes effective on the modal properties of the $r$-modes only when the field strength $B_S$ is much greater than $10^{14}$G. We also find that the damping effects caused by very short magnetic perturbations in the surface layer are not important for the $r$-mode instability of rapidly rotating neutron stars if the field strength $B_S$ is smaller than $10^{12}$G.Comment: Accepted for publication in M