Scissoring of cerebral aneurysm clips: mechanical endurance of clip twisting

Although the cerebral aneurysm clip "scissoring" phenomenon is known to occur due to twisting of the aneurysm clip blades during surgery, there have been few previous studies of scissoring. In the present study, we examined the in vitro endurance of clip twisting to assess clip scissoring. To evaluate the clip-scissoring effect, we measured torque at the rotating aneurysm clip head (Sugita and Yasargil clips) using our own manufactured product. A silicon sheet 1 mm thick was clipped at several depths (3, 6, and 9 mm), and the clip head was mechanically rotated. Straight and fenestrated clips of titanium alloy were used in the present study. Cobalt alloy straight clips were also examined. Preliminary experiments indicated that torque values during clip head rotation dropped when the blades crossed. In addition, torque values before blade crossing showed resistance to slippage of the blades. Torque values of both Sugita and Yasargil clips were directly proportional to the blade depth. There were no differences between straight and fenestrated Sugita clips. Although the torque was greater in cobalt alloy than titanium alloy Sugita clips, the torque values of Yasargil cobalt and titanium clips were identical. We found some differences in torque values during clip head rotation between Sugita and Yasargil clips. Based on the results of twisting experiments, scissoring is likely to occur when occluding the neck of the aneurysm only with the tips of long clip blades.ArticleNEUROSURGICAL REVIEW. 35(2):219-224 (2012)journal articl

INITIAL SCREENING OF FAST-GROWING TREE SPECIES BEING TOLERANT OF DRY TROPICAL PEATLANDS IN CENTRAL KALIMANTAN, INDONESIA

An investigation of the recruit, survivorship and growth of naturally regenerating tree species on canal bank was conducted to select tree species which are suitable for preceding planting in drained and burnt peat swamp lands in Central Kalimantan, Indonesia. Top of the canal bank were open, with greater soil moisture deficit and higher soil temperatures than on the next intact forest floor. The abundant trees were asam-asam (Ploiarium alternifolium),garunggang (Cratoxylon arborescens) and tumih (Combretocarpus rotundatus). New regeneration of these trees on the canal bank was confirmed during this investigation and mortality was very low. These results indicated that P. alternifolium,C. arborescens and C. rotundatuswere tolerant of intensive radiation, soil drought and high soil temperatures during germination. The annual height increments were 189-232 cm y-1 (P. alternifolium),118-289 cm y-1 (C. arborescens)and 27-255 cm y-1 (C. rotundatus); thus, these three species could be classified as fast-growing with tolerance to open and dry conditions. Such characteristics were important to avoid competition with herbs, ferns,and/ or climbers. The results·suggest that P.alternifolium,C. arborescens and C. rotundatusare suitable for preceding planting for the rehabilitation of the disturbed peat swamp forests of Central Kalimantan

Initial Screening of Fast-growing Tree Species Being Tolerant of Dry Tropical Peatlands in Central Kalimantan, Indonesia

An investigation of the recruit, survivorship and growth of naturally regenerating tree species on canal bank was conducted to select tree species which are suitable for preceding planting in drained and burnt peat swamp lands in Central Kalimantan, Indonesia. Top of the canal bank were open, with greater soil moisture deficit and higher soil temperatures than on the next intact forest floor. The abundant trees were asam-asam (Ploiarium alternifolium),garunggang (Cratoxylon arborescens) and tumih (Combretocarpus rotundatus). New regeneration of these trees on the canal bank was confirmed during this investigation and mortality was very low. These results indicated that P. alternifolium,C. arborescens and C. rotundatuswere tolerant of intensive radiation, soil drought and high soil temperatures during germination. The annual height increments were 189-232 cm y-1 (P. alternifolium),118-289 cm y-1 (C. arborescens)and 27-255 cm y-1 (C. rotundatus); thus, these three species could be classified as fast-growing with tolerance to open and dry conditions. Such characteristics were important to avoid competition with herbs, ferns,and/ or climbers. The results·suggest that P.alternifolium,C. arborescens and C. rotundatusare suitable for preceding planting for the rehabilitation of the disturbed peat swamp forests of Central Kalimantan

Allergin-1 on mast cells suppresses house dust mite-induced airway hyperresponsiveness in mice

Although airway hyperresponsiveness (AHR) is a prominent feature of asthma, how it is regulated remains incompletely understood. Allergin-1, an inhibitory immunoglobulin-like receptor containing an immunoreceptor tyrosine-based inhibitory motif (ITIM), is expressed on human and mouse mast cells (MCs) and inhibits high-affinity receptor for IgE (FcεRI)-mediated signaling. Using MC-deficient KitW-sh/W-sh mice and Mas-TRECK mice, which carries a diphtheria toxin (DT)-induced MC deletion system based on il4 enhancer elements, we demonstrate here that MCs are involved in the induction of house dust mite (HDM)-induced AHR. Further, we show that MCs deficient in Allergin-1 exacerbated HDM-induced AHR, but had no effect on airway inflammation. In vitro analysis demonstrated that Allergin-1 inhibited anti-HDM allergen antibody-dependent HDM allergen-mediated degranulation by MCs. Thus, Allergin-1 on MCs plays an important role in the regulation of HDM-induced AHR

EMPRESS. II. Highly Fe-Enriched Metal-poor Galaxies with ∼1.0\sim 1.0 (Fe/O)⊙_\odot and 0.020.02 (O/H)⊙_\odot : Possible Traces of Super Massive (>300M⊙>300 M_{\odot}) Stars in Early Galaxies

We present element abundance ratios and ionizing radiation of local young low-mass (~$10^{6}$ M_sun) extremely metal poor galaxies (EMPGs) with a 2% solar oxygen abundance (O/H)_sun and a high specific star-formation rate (sSFR~300 Gyr$^{-1}$), and other (extremely) metal poor galaxies, which are compiled from Extremely Metal-Poor Representatives Explored by the Subaru Survey (EMPRESS) and the literature. Weak emission lines such as [FeIII]4658 and HeII4686 are detected in very deep optical spectra of the EMPGs taken with 8m-class telescopes including Keck and Subaru (Kojima et al. 2019, Izotov et al. 2018), enabling us to derive element abundance ratios with photoionization models. We find that neon- and argon-to-oxygen ratios are comparable to those of known local dwarf galaxies, and that the nitrogen-to-oxygen abundance ratios (N/O) are lower than 20% (N/O)_sun consistent with the low oxygen abundance. However, the iron-to-oxygen abundance ratios (Fe/O) of the EMPGs are generally high; the EMPGs with the 2%-solar oxygen abundance show high Fe/O ratios of ~90-140% (Fe/O)_sun, which are unlikely explained by suggested scenarios of Type Ia supernova iron productions, iron's dust depletion, and metal-poor gas inflow onto previously metal-riched galaxies with solar abundances. Moreover, these EMPGs have very high HeII4686/H$\beta$ ratios of ~1/40, which are not reproduced by existing models of high-mass X-ray binaries whose progenitor stellar masses are less than 120 M_sun. Comparing stellar-nucleosynthesis and photoionization models with a comprehensive sample of EMPGs identified by this and previous EMPG studies, we propose that both the high Fe/O ratios and the high HeII4686/H$\beta$ ratios are explained by the past existence of super massive ($>$300 M_sun) stars, which may evolve into intermediate-mass black holes ($\gtrsim$100 M_sun).Comment: ApJ in press. 23 pages, 7 Figures, 6 Table

Extremely Metal-Poor Representatives Explored by the Subaru Survey (EMPRESS). I. A Successful Machine Learning Selection of Metal-Poor Galaxies and the Discovery of a Galaxy with M*<10^6 M_sun and 0.016 Z_sun

We have initiated a new survey for local extremely metal-poor galaxies (EMPGs) with Subaru/Hyper Suprime-Cam (HSC) large-area (~500 deg^2) optical images reaching a 5 sigma limit of ~26 magnitude, about 100 times deeper than the Sloan Digital Sky Survey (SDSS). To select Z/Z_sun<0.1 EMPGs from ~40 million sources detected in the Subaru images, we first develop a machine-learning (ML) classifier based on a deep neural network algorithm with a training data set consisting of optical photometry of galaxy, star, and QSO models. We test our ML classifier with SDSS objects having spectroscopic metallicity measurements, and confirm that our ML classifier accomplishes 86%-completeness and 46%-purity EMPG classifications with photometric data. Applying our ML classifier to the photometric data of the Subaru sources as well as faint SDSS objects with no spectroscopic data, we obtain 27 and 86 EMPG candidates from the Subaru and SDSS photometric data, respectively. We conduct optical follow-up spectroscopy for 10 out of our EMPG candidates with Magellan/LDSS-3+MagE, Keck/DEIMOS, and Subaru/FOCAS, and find that the 10 EMPG candidates are star-forming galaxies at z=0.007-0.03 with large H_beta equivalent widths of 104-265 A, stellar masses of log(M*/M_sun)=5.0-7.1, and high specific star-formation rates of ~300 Gyr^{-1}, which are similar to those of early galaxies at z>6 reported recently. We spectroscopically confirm that 3 out of 10 candidates are truly EMPGs with Z/Z_sun<0.1, one of which is HSC J1631+4426, the most metal-poor galaxy with Z/Z_sun=0.016 reported ever.Comment: 30 pages, 26 figures, and 8 tables; (Revision: metallicities changed due to the use of a more pricise dust correction method, but conclusion does not change, Minor: a table, some figures, and sentences are added for a clear explanation.

Allergin-1 inhibits TLR2-mediated mast cell activation and suppresses dermatitis

TLR2 recognizes cell wall components of Staphylococcus aureus, which colonizes >90% of atopic eczematous skin lesions. The regulatory mechanisms of TLR2 signaling in the skin remain unclear. Allergin-1, an inhibitory immunoglobulin-like receptor containing an ITIM, is expressed on mast cells (MCs) and inhibits IgE-mediated anaphylaxis in mice. Here, we show that Allergin-1 inhibits TLR2-mediated activation of, and inflammatory cytokine production by, MCs in vitro. Compared with wild-type mice, Allergin-1-deficient mice showed enhanced ear swelling with enhanced collagen deposition and greater Ly6G+ neutrophil recruitment after intra-dermal injection of Pam2CSK4 into pinnae. Using Mas–TRECK mice, which is an MC deletion system based on il4 enhancer elements, we also demonstrated that Allergin-1 on MCs is responsible for the Pam2CSK4-induced ear swelling. These results suggest that Allergin-1 on skin MCs suppresses TLR2-induced dermatitis