817 research outputs found

    Distribution and Kinematics of H I through Raman He II Spectroscopy of NGC 6302

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    The young planetary nebula NGC 6302 is known to exhibit Raman-scattered He II features at 6545 and 4851 Angstrom. These features are formed through inelastic scattering of He IIλλ\lambda\lambda 1025 and 972 with hydrogen atoms in the ground state, for which the cross sections are 1.2×10211.2 \times 10^{-21} and 1.4×1022 cm21.4\times 10^{-22} {\rm\ cm^2}, respectively. We investigate the spectrum of NGC 6302 archived in the ESO Science Portal. Our Gaussian line fitting analysis shows that the Raman-scattered He II features are broader and more redshifted than the hypothetical model Raman features that would be formed in a cold static H I medium. We adopt a simple scattering geometry consisting of a compact He II emission region surrounded by a H I medium to perform Monte Carlo simulations using the radiative transfer code STaRS{\it STaRS}. Our simulations show that the H I region is characterized by the H I column density NHI=3×1021 cm2N_{\rm HI}=3\times 10^{21}{\rm\ cm^{-2}} with the random speed component vran=10 km s1v_{\rm ran}=10{\rm\ km\ s^{-1}} expanding with a speed $v_{\rm exp}= 13{\rm\ km\ s^{-1}}fromtheHeIIemissionregion.Basedonourbestfitparameters,weestimatetheHImassoftheneutralmedium from the He II emission region. Based on our best fit parameters, we estimate the H I mass of the neutral medium M_{\rm HI} \simeq 1.0\times 10^{-2}\ {\rm M_\odot}$, pointing out the usefulness of Raman He II spectroscopy as a tool to trace H I components.Comment: 12 pages, 8 figures, accepted for publication in Ap

    In vitro activity of gemifloxacin against recent clinical isolates of bacteria in Korea.

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    Gemifloxacin is an enhanced-affinity fluoroquinolone with broad-spectrum antibacterial activity. In Korea, resistant bacteria are relatively more prevalent than in other industrialized countries. In this study, we studied the in vitro activities of gemifloxacin, gatifloxacin, moxifloxacin, levofloxacin, ciprofloxacin, and other commonly used antimicrobial agents against 1,689 bacterial strains isolated at four Korean university hospitals during 1999-2000. Minimum inhibitory concentrations (MICs) were determined using the agar dilution method of National Committee for Clinical Laboratory Standards. Gemifloxacin had the lowest MICs for the respiratory pathogens: 90% of Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae were inhibited by 0.06, 0.03, and 0.03 mg/L, respectively. Gemifloxacin was more active than the other fluoroquinolones against methicillin-susceptible Staphylococcus aureus, coagulase-negative staphylococci, streptococci, and Enterococcus faecalis. The MIC90s of gemifloxacin for Klebsiella oxytoca, Proteus vulgaris, and non-typhoidal Salmonella spp. were 0.25, 1.0, and 0.12 mg/L, respectively, while those for other Gram-negative bacilli were 4-64 mg/L. In conclusion, gemifloxacin was the most active among the comparative agents against Gram-positive species, including respiratory pathogens isolated in Korea

    Human Umbilical Cord Blood-Derived Mesenchymal Stem Cell Therapy Promotes Functional Recovery of Contused Rat Spinal Cord through Enhancement of Endogenous Cell Proliferation and Oligogenesis

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    Numerous studies have shown the benefits of mesenchymal stem cells (MSCs) on the repair of spinal cord injury (SCI) model and on behavioral improvement, but the underlying mechanisms remain unclear. In this study, to investigate possible mechanisms by which MSCs contribute to the alleviation of neurologic deficits, we examined the potential effect of human umbilical cord blood-derived MSCs (hUCB-MSCs) on the endogenous cell proliferation and oligogenesis after SCI. SCI was injured by contusion using a weight-drop impactor and hUCB-MSCs were transplanted into the boundary zone of the injured site. Animals received a daily injection of bromodeoxyuridine (BrdU) for 7 days after treatment to identity newly synthesized cells of ependymal and periependymal cells that immunohistochemically resembled stem/progenitor cells was evident. Behavior analysis revealed that locomotor functions of hUCB-MSCs group were restored significantly and the cavity volume was smaller in the MSCs-transplanted rats compared to the control group. In MSCs-transplanted group, TUNEL-positive cells were decreased and BrdU-positive cells were significantly increased rats compared with control group. In addition, more of BrdU-positive cells expressed neural stem/progenitor cell nestin and oligo-lineage cell such as NG2, CNPase, MBP and glial fibrillary acidic protein typical of astrocytes in the MSC-transplanted rats. Thus, endogenous cell proliferation and oligogenesis contribute to MSC-promoted functional recovery following SCI

    Patterned Si thin film electrodes for enhancing structural stability

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    A patterned film (electrode) with lozenge-shaped Si tiles could be successfully fabricated by masking with an expanded metal foil during film deposition. Its electrochemical properties and structural stability during the charge-discharge process were examined and compared with those of a continuous (conventional) film electrode. The patterned electrode exhibited a remarkably improved cycleability (75% capacity retention after 120 cycles) and an enhanced structural stability compared to the continuous electrode. The good electrochemical performance of the patterned electrode was attributed to the space between Si tiles that acted as a buffer against the volume change of the Si electrode

    Huge carotid body paraganglioma

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    A 33-year-old woman was admitted to our hospital with a slow-growing mass in the left side of her neck. The mass was found to be a huge (73 × 56 × 54 mm) carotid body paraganglioma. Another 21 mm-size tumor was incidentally detected at the right carotid bifurcation. She had hoarseness and Horner's syndrome of her left side. Both tumors were surgically removed. There were no cerebrovascular complications but some neurologic complications occurred when the left tumor was removed

    An Unusual Case of Carcinoma Erysipelatoides Originating from Gastric Adenocarcinoma

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    Carcinoma erysipelatoides, also known as inflammatory metastatic carcinoma, is a rare form of cutaneous metastasis. It is most commonly caused by breast carcinoma, but rarely associated with gastric adenocarcinoma. Herein, we report an unusual case of carcinoma erysipelatoides in a 55 year-old female who had been diagnosed with signet ring cell carcinoma of the stomach metastasizing to ovaries
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