2,299 research outputs found
Microlensing Optical Depth Revisited with Recent Star Counts
More reliable constraints on the microlensing optical depth comes from a
better understanding of the Galactic model. Based on well-constrained Galactic
bulge and disk models constructed from survey observations, such as, HST,
2MASS, and SDSS, we calculate the microlensing optical depths toward the
Galactic bulge fields, and compare them with recent results of microlensing
surveys. We test chi^2 statistics of microlensing optical depths expected from
those models, as well as previously proposed models, using two types of data:
optical depth map in (l, b) and averaged optical depth over the Galactic
longitude l as a function of the latitude b. From this analysis, we find that
the Galactic bulge models of 2MASS, Han & Gould (2003), and G2 of Stanek et al.
(1997) show a good agreement with the microlensing optical depth profiles for
all the microlensing observations, compared with E2 of Stanek et al. (1997). We
find, on the other hand, that models involving an SDSS disk model produce
relatively higher chi^2 values. It should be noted that modeled microlensing
optical depths diverge in the low Galactic latitude, |b| < 2 arcdeg. Therefore,
we suggest the microlensing observation toward much closer to central regions
of the Galaxy to further test the proposed Galactic models, if it is more
technically feasible than waiting for large data set of microlensing events.Comment: 15 pages, 3 figures and 3 tables, accepted for publication in Ap
Changes in Cardiovascular Disease Burden in China after Release of the 2011 Chinese Guidelines for Cardiovascular Disease Prevention: A Bayesian Causal Impact Analysis
Objective: This study aimed to investigate the effects of the 2011 Chinese Society of Cardiology guidelines (2011 CSC guidelines) on the overall and subtype specific cardiovascular disease (CVD) burden in China. Methods: We conducted a Bayesian causal impact analysis to investigate changes in the burden of CVD overall and 13 subcategories, before and after release of the 2011 CSC guidelines, by using publicly available data during 1990–2019. Results: The 2011 CSC guidelines were associated with moderate declines in CVD mortality (5.7%; equivalent to 161 per 100,000) and DALYs (2.9%; 1429 per 100,000), but small increases in incidence and prevalence, with an approximately 1-year lagged effect. Similar impact patterns were observed for ischemic stroke, cardiomyopathy and myocarditis, and aortic aneurysm. Release of the 2011 CSC guidelines increased intracerebral hemorrhage incidence, but sharply decreased rheumatic, ischemic, and non-rheumatic valvular heart disease mortality and DALY rates. The burden of other CVD subcategories was unchanged. Health worker numbers, population size, disposable income, hospital admission rates, and crude death rates were critical contributors to CVD burden beyond the 2011 CSC guidelines. Conclusion: The 2011 CSC guidelines decreased the burden of CVD and several subcategories. However, efforts to enhance health promotion and strengthen healthcare remain urgently needed in China
Quantum Hall effect and Landau level crossing of Dirac fermions in trilayer graphene
We investigate electronic transport in high mobility (\textgreater 100,000
cm/Vs) trilayer graphene devices on hexagonal boron nitride, which
enables the observation of Shubnikov-de Haas oscillations and an unconventional
quantum Hall effect. The massless and massive characters of the TLG subbands
lead to a set of Landau level crossings, whose magnetic field and filling
factor coordinates enable the direct determination of the
Slonczewski-Weiss-McClure (SWMcC) parameters used to describe the peculiar
electronic structure of trilayer graphene. Moreover, at high magnetic fields,
the degenerate crossing points split into manifolds indicating the existence of
broken-symmetry quantum Hall states.Comment: Supplementary Information at
http://jarilloherrero.mit.edu/wp-content/uploads/2011/04/Supplementary_Taychatanapat.pd
Development of a 2-Channel Embedded Infrared Fiber-Optic Temperature Sensor Using Silver Halide Optical Fibers
A 2-channel embedded infrared fiber-optic temperature sensor was fabricated using two identical silver halide optical fibers for accurate thermometry without complicated calibration processes. In this study, we measured the output voltages of signal and reference probes according to temperature variation over a temperature range from 25 to 225 °C. To decide the temperature of the water, the difference between the amounts of infrared radiation emitted from the two temperature sensing probes was measured. The response time and the reproducibility of the fiber-optic temperature sensor were also obtained. Thermometry with the proposed sensor is immune to changes if parameters such as offset voltage, ambient temperature, and emissivity of any warm object. In particular, the temperature sensing probe with silver halide optical fibers can withstand a high temperature/pressure and water-chemistry environment. It is expected that the proposed sensor can be further developed to accurately monitor temperature in harsh environments
A Case of Minimal Change Disease Treated Successfully with Mycophenolate Mofetil in a Patient with Systemic Lupus Erythematosus
The World Health Organization classifies lupus nephritis as class I to V or VI. However, a few cases of minimal change glomerulopathy have been reported in association with systemic lupus erythematosus (SLE). Mycophenolate mofetil has been shown to be effective for treatment of minimal change disease and lupus nephritis. A 24-year-old woman diagnosed with SLE five years prior to presentation complained of a mild generalized edema. The urinalysis showed microscopic hematuria and proteinuria. The assessed amount of total proteinuria was 1,618 mg/24 hours. A renal biopsy demonstrated diffuse fusion of the foot processes of podocytes on electron microscopy. Mycophenolate mofetil was started in addition to the maintenance medications of prednisolone 10 mg/day and hydroxychloroquine 400 mg/day. After six months of treatment, the microscopic hematuria and proteinuria resolved, and the total urine protein decreased to 100 mg/24 hours
Disc Hemorrhages in Patients with both Normal Tension Glaucoma and Branch Retinal Vein Occlusion in Different Eyes
PURPOSE: To document the clinical features of disc hemorrhage in patients with branch retinal vein occlusion (BRVO) and normal tension glaucoma (NTG), and to evaluate the relationship between BRVO and NTG with disc hemorrhages. METHODS: From July 2001 to May 2006, sixteen patients with both NTG and BRVO in different eyes were successively collected from outpatient population of Seoul National University Hospital in this observational case series. The frequency and location of disc hemorrhages, history of associated systemic diseases, and the order of the time of diagnosis between NTG and BRVO were studied. RESULTS: All patients had unilateral BRVO, and their mean age was 63.3+/-10.6 years. Disc hemorrhages were detected in eight patients (50%) during the mean follow-up of 26.8 months (range, 3-96 months). Six patients (75%) had disc hemorrhages in the non-BRVO eyes and two patients (25%) in BRVO eyes. Five hemorrhages (62.5%) were located at inferior-temporal quadrant of the optic disc. History of systemic hypertension was identified in 12 patients (75.0%). In 11 patients (68.8%), NTG was diagnosed at the same time as BRVO. CONCLUSIONS: A higher frequency of disc hemorrhages was identified in patients with both BRVO and NTG. Therefore, some cases of NTG, especially with disc hemorrhages, may share a common vascular pathophysiology with BRVO
One-Dimensional Hydrogen-Bonded Infinite Chain from Nickel(II) Tetraaza Macrocyclic Complex and 1,2-Cyclopentanedicarboxylate Ligand
The reaction of [Ni(L)]Cl2·2H2O (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo [14,4,01.18,07.12]docosane) with trans-1,2-cyclopentanedicarboxylic acid (H2-cpdc) yields a 1D hydrogen-bonded infinite chain with formula [Ni(L)(H-cpdc−)2] (1). This complex has been characterized by X-ray crystallography, spectroscopy and cyclic voltammetry. The crystal structure of 1 exhibits a distorted octahedral geometry about Ni atom with four nitrogen atoms of the macrocycle and two oxygen atoms of the H-cpdc− ligand at the axial position. Compound 1 crystallizes in the monoclinic system P21/c with a = 8.7429(17), b = 10.488(2), c = 18.929(4) Å, β = 91.82(2), V = 1734.8(6) Å3, Z = 2. Electronic spectrum of 1 reveals a high-spin octahedral environment. Cyclic voltammetry of 1 undergoes two waves of a one-electron transfer corresponding to NiII/NiIII and NiII/NiI processes
Nearly-room-temperature ferromagnetism and tunable anomalous Hall effect in atomically thin Fe4CoGeTe2
Itinerant ferromagnetism at room temperature is a key ingredient for spin
transport and manipulation. Here, we report the realization of
nearly-room-temperature itinerant ferromagnetism in Co doped Fe5GeTe2 thin
flakes. The ferromagnetic transition temperature TC (323 K - 337 K) is almost
unchanged when thickness is down to 12 nm and is still about 284 K at 2 nm
(bilayer thickness). Theoretical calculations further indicate that the
ferromagnetism persists in monolayer Fe4CoGeTe2. In addition to the robust
ferromagnetism down to the ultrathin limit, Fe4CoGeTe2 exhibits an unusual
temperature- and thickness-dependent intrinsic anomalous Hall effect. We
propose that it could be ascribed to the dependence of band structure on
thickness that changes the Berry curvature near the Fermi energy level subtly.
The nearly-room-temperature ferromagnetism and tunable anomalous Hall effect in
atomically thin Fe4CoGeTe2 provide opportunities to understand the exotic
transport properties of two-dimensional van der Waals magnetic materials and
explore their potential applications in spintronics.Comment: 28 pages, 4 figures, 1 tabl
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