1,227 research outputs found
Measurement of the Background Activities of a 100Mo-enriched powder sample for AMoRE crystal material using a single high purity germanium detector
The Advanced Molybdenum-based Rare process Experiment (AMoRE) searches for
neutrino-less double-beta (0{\nu}\b{eta}\b{eta}) decay of 100Mo in enriched
molybdate crystals. The AMoRE crystals must have low levels of radioactive
contamination to achieve low background signals with energies near the Q-value
of the 100Mo 0{\nu}\b{eta}\b{eta} decay. To produce low-activity crystals,
radioactive contaminants in the raw materials used to form the crystals must be
controlled and quantified. 100EnrMoO3 powder, which is enriched in the 100Mo
isotope, is of particular interest as it is the source of 100Mo in the
crystals. A high-purity germanium detector having 100% relative efficiency,
named CC1, is being operated in the Yangyang underground laboratory. Using CC1,
we collected a gamma spectrum from a 1.6-kg 100EnrMoO3 powder sample enriched
to 96.4% in 100Mo. Activities were analyzed for the isotopes 228Ac, 228Th,
226Ra, and 40K. They are long-lived naturally occurring isotopes that can
produce background signals in the region of interest for AMoRE. Activities of
both 228Ac and 228Th were < 1.0 mBq/kg at 90% confidence level (C.L.). The
activity of 226Ra was measured to be 5.1 \pm 0.4 (stat) \pm 2.2 (syst) mBq/kg.
The 40K activity was found as < 16.4 mBq/kg at 90% C.L.Comment: 20 pages, 6 figures, 5 table
A Study of Micronucleus Induction with Methyl Formate and 2-Methylbutane in Bone Marrow Cells of Male ICR Mice
Objectives: We investigated the genotoxicity of two chemicals, methyl formate and 2-methylbutane, using male ICR mice bone marrow cells for the screening of micronucleus induction. Although these two chemicals have already been tested numerous times, a micronucleus test has not been conducted and the amounts used have recently been increased.Methods: 7 week male ICR mice were tested at dosages of 250, 500, and 1,000mg/kg for methyl formate and 500, 1,000, and 2,000mg/kg for 2-methlybutane, respectively. After 24 hours of oral administration with the two chemicals, the mice were sacrificed and their bone marrow cells were prepared for smearing slides.Results: As a result of counting the micronucleated polychromatic erythrocyte (MNPCE) of 2,000 polychromatic erythrocytes (PCE), all treated groups expressed no statistically significant increase of MNPCE compared to the negative control group. There were no clinical signs related with the oral exposure of these two chemicals.Conclusion: It was concluded that the two chemicals did not induce micronucleus in the bone marrow cells of ICR mice, and there was no direct proportion with dosage. These results indicate that the two chemicals have no mutagenic potential under each study condition
Arthroscopic Capsular Repair without Relaying Sutures: ‘Simple Sewing Technique’
We report a simple technique for repairing capsular tear, using only a hook-like, cannulated instrument and braided sutures without relaying steps. A No. 2 braided suture is passed through the lumen of the instrument. Under direct arthroscopic view, the tip of the instrument is passed through the side of the capsule that has previously been separated with the probe. One end of the suture is retrieved with a grasper through a separate portal. The tip is moved back without withdrawing through the skin, and reinserted into the other side of the capsule. Holding the end retrieved earlier, the other end of the suture is retrieved with a suture retriever. After complete removal of the instrument, the suture is tied through a cannula using the standard knot tying techniques. The same procedures are repeated for other required knots
Rotating Arm Internally Can Change the Arthroscopic Diagnosis of a Partial-thickness Tear of the Subscapularis
Background The aims of this study were (1) to examine the footprint of the subscapularis tendon using the traditional posterior portal and 30° arthroscope by simple internal rotation of the arm during surgery, and (2) to classify the pattern of a subscapularis partial-thickness tear. Methods This study analyzed a total of 231 patients with a partial-thickness subscapularis tear from 550 consecutive patients undergoing an arthroscopic operation who had a visualization of the subscapularis tendon footprint by internal rotation of the arm. First, the patients were classified into four categories according to the tear pattern: (1) stable lamination, (2) unstable lamination, (3) avulsion, and (4) laminated avulsion. Randomized arthroscopic videos were reviewed blindly by two independent orthopedic surgeons. The pattern of the tear of the subscapularis at the neutral position and after internal rotating the arm were assessed and compared with the treatment decision (level IV case series). Results Stable lamination, unstable lamination, avulsion, and laminated avulsion were observed in 9.1% (n=21), 20.8% (n=48), 41.1% (n=95), and 29.0% (n=67) of cases, respectively. In 145 out of 231 cases (62.8%), the decision was changed after inspecting the footprint after internal rotation of the arm, and the treatment method was changed in 116 (50.2%) cases. Conclusions In a subscapularis tendon partial-thickness tear, inspecting the footprint of the subscapularis tendon is essential to diagnosing and deciding on the appropriate treatment. In addition, simply internal rotating the arm during surgery when using the traditional posterior portal and 30° arthroscope can be a valuable method
Prognostic factors related with outcomes in traumatic out-of-hospital cardiac arrest patients without prehospital return of spontaneous circulation: a nationwide observational study
Objective To evaluate the prognostic factors associated with the sustained return of spontaneous circulation (ROSC) and survival to hospital discharge in traumatic out-of-hospital cardiac arrest (TOHCA) patients without prehospital ROSC. Methods We analyzed Korean nationwide data from the Out-of-Hospital Cardiac Arrest Surveillance, and included adult TOHCA patients without prehospital ROSC from January 2012 to December 2016. The primary outcome was sustained ROSC (>20 minutes). The secondary outcome was survival to discharge. Multivariate analysis was performed to investigate factors associated with the outcomes of TOHCA patients. Results Among 142,905 cases of OHCA, 8,326 TOHCA patients were investigated. In multivariate analysis, male sex (odds ratio [OR], 1.326; 95% confidence interval [CI], 1.103–1.594; P=0.003), and an initial shockable rhythm (OR, 1.956; 95% CI, 1.113–3.439; P=0.020) were significantly associated with sustained ROSC. Compared with traffic crash, collision (OR, 1.448; 95% CI, 1.086–1.930; P=0.012) was associated with sustained ROSC. Fall (OR, 0.723; 95% CI, 0.589–0.888; P=0.002) was inversely associated with sustained ROSC. Male sex (OR, 1.457; 95% CI, 1.026–2.069; P=0.035) and an initial shockable rhythm (OR, 4.724; 95% CI, 2.451–9.106; P<0.001) were significantly associated with survival to discharge. Metropolitan city (OR, 0.728; 95% CI, 0.541–0.980; P=0.037) was inversely associated with survival to discharge. Compared with traffic crash, collision (OR, 1.745; 95% CI, 1.125–2.708; P=0.013) was associated with survival to discharge. Conclusion Male sex, an initial shockable rhythm, and collision could be favorable factors for sustained ROSC, whereas fall could be an unfavorable factor. Male sex, non-metropolitan city, an initial shockable rhythm, and collision could be favorable factors in survival to discharge
Decreased expression of extracellular matrix proteins and trophic factors in the amygdala complex of depressed mice after chronic immobilization stress
BACKGROUND: The amygdala plays an essential role in controlling emotional behaviors and has numerous connections to other brain regions. The functional role of the amygdala has been highlighted by various studies of stress-induced behavioral changes. Here we investigated gene expression changes in the amygdala in the chronic immobilization stress (CIS)-induced depression model. RESULTS: Eight genes were decreased in the amygdala of CIS mice, including genes for neurotrophic factors and extracellular matrix proteins. Among these, osteoglycin, fibromodulin, insulin-like growth factor 2 (Igf2), and insulin-like growth factor binding protein 2 (Igfbp2) were further analyzed for histological expression changes. The expression of osteoglycin and fibromodulin simultaneously decreased in the medial, basolateral, and central amygdala regions. However, Igf2 and Igfbp2 decreased specifically in the central nucleus of the amygdala. Interestingly, this decrease was found only in the amygdala of mice showing higher immobility, but not in mice displaying lower immobility, although the CIS regimen was the same for both groups. CONCLUSIONS: These results suggest that the responsiveness of the amygdala may play a role in the sensitivity of CIS-induced behavioral changes in mice
Pre-hospital i-gel blind intubation for trauma: a simulation study
Objective This study aimed to evaluate the efficacy of i-gel blind intubation (IGI) as a rescue device for definitive airway management in ground intubation for pre-hospital trauma patients. Methods A prospective randomized crossover study was conducted with 18 paramedics to examine intubation performance of two blind intubation techniques through a supraglottic airway devices (IGI and laryngeal mask airway Fastrach), compared with use of a Macintosh laryngoscope (MCL). Each intubation was conducted at two levels of patient positions (ground- and stretcher-level). Primary outcomes were the intubation time and the success rate for intubation. Results The intubation time (sec) of each intubation technique was not significantly different between the two positions. In both patient positions, the intubation time of IGI was shortest among the three intubation techniques (17.9±5.2 at the ground-level and 16.9±3.8 at the stretcher-level). In the analysis of cumulative success rate and intubation time, IGI was the fastest to reach 100% success among the three intubation techniques regardless of patient position (all P<0.017). The success of intubation was only affected by the intubation technique, and IGI achieved more success than MCL (odds ratio, 3.6; 95% confidence interval, 1.1 to 11.6; P=0.03). Conclusion The patient position did not affect intubation performance. Additionally, the intubation time with blind intubation through supraglottic airway devices, especially with IGI, was significantly shorter than that with MCL
Long-Range Orbital Transport in Ferromagnets
While it is often assumed that the orbital transport is short-ranged due to
strong crystal field potential and orbital quenching, we show that orbital
propagation can be remarkably long-ranged in ferromagnets. In contrast to spin
transport, which exhibits an oscillatory decaying behavior by spin dephasing,
the injected orbital angular momentum does not oscillate and decays slowly.
This unusual feature is attributed to nearly degenerate states in
-space, which form hot-spots for the intrinsic orbital response. We
demonstrate this in a bilayer consisting of a nonmagnet and a ferromagnet,
where the orbital Hall current is injected from a nonmagnet into a ferromagnet.
Interaction of the orbital Hall current with the magnetization in the
ferromagnet results in an intrinsic response of the orbital angular momentum
which propagates far beyond the spin dephasing length. This gives rise to a
distinct type of orbital torque on the magnetization, increasing with the
thickness of the ferromagnet. Such behavior may serve as critical long-sought
evidence of orbital transport to be directly tested in experiments. Our
findings open the possibility of using long-range orbital transport in
orbitronic device applications
- …