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In this paper, the generation of relativistic electron mirrors (REMs) and the reflection of an ultra-short laser off this mirrors are discussed, applying two-dimensional particle-in-cell (2D-PIC) simulations. REMs with ultra-high acceleration and expanding velocity can be produced from a solid nanofoil illuminated normally by an ultra-intense femtosecond laser pulse with a sharp rising edge. Chirped attosecond pulse can be produced through the reflection of a counter-propagating probe laser off the accelerating REM. In the electron moving frame, the plasma frequency of the REM keeps decreasing due to its rapidly expanding. The laser frequency, on the contrary, keeps increasing due to the acceleration of REM and the relativistic Doppler shift from the lab frame to the electron moving frame. Within an ultra-short time interval, the two frequencies will be equal in the electron moving frame, which leads the resonance between laser and REM. The reflected radiation near this interval and the corresponding spectra will be amplified due to the resonance. Through adjusting the arriving time of the probe laser, certain part of the reflected field could be selectively amplified or depressed, leading to the selectively adjusting of the corresponding spectra.
Gravitational waves from coalescing neutron stars encode information about nuclear matter at extreme densities, inaccessible by laboratory experiments. The late inspiral is influenced by the presence of tides, which depend on the neutron star equation of state. Neutron star mergers are expected to often produce rapidly rotating remnant neutron stars that emit gravitational waves. These will provide clues to the extremely hot post-merger environment. This signature of nuclear matter in gravitational waves contains most information in the 2–4 kHz frequency band, which is outside of the most sensitive band of current detectors. We present the design concept and science case for a Neutron Star Extreme Matter Observatory (NEMO): a gravitational-wave interferometer optimised to study nuclear physics with merging neutron stars. The concept uses high-circulating laser power, quantum squeezing, and a detector topology specifically designed to achieve the high-frequency sensitivity necessary to probe nuclear matter using gravitational waves. Above 1 kHz, the proposed strain sensitivity is comparable to full third-generation detectors at a fraction of the cost. Such sensitivity changes expected event rates for detection of post-merger remnants from approximately one per few decades with two A+ detectors to a few per year and potentially allow for the first gravitational-wave observations of supernovae, isolated neutron stars, and other exotica.
We prove the following two basis theorems for
-sets of reals:
-set has a perfect
-subset if and only if it has a nonthin
-subset, and this is equivalent to the statement that there is a nonconstructible real.
-set has an uncountable
-subset if and only if either every real is constructible or
We also apply the method that proves (2) to show that if there is a nonconstructible real, then there is a perfect
-set with no nonempty
-thin subset, strengthening a result of Harrington .
Sedative–hypnotic medication use has been related to severe adverse events and risks. This study investigated the prevalence of and characteristics associated with the use of sedatives and hypnotics among community-dwelling elderly persons aged 65 years and over in Taiwan.
A representative sample of community-dwelling adults was recruited. Clinical and sociodemographic data were collected for assessing physical, mental, and cognitive functioning and disorders. Sedatives and hypnotics use was determined via both self-reporting and prescription records. Logistic regression modeling was used to evaluate associations between sedative–hypnotic use and demographic and health status.
Among the 3,978 participants aged 65 years and over, the rate of sedative–hypnotic use was 19.7% (n = 785). 4.5% (n = 35) of users reported sedative–hypnotic use without a doctor's prescription. Several sociodemographic characteristics were positively associated with sedative and hypnotic use, including older age, female gender, higher education level, married status, unemployment, and current alcohol consumption. Comorbid chronic and cardiovascular diseases, mental illness, depression, pain, and sleep problems also increased the likelihood of sedative–hypnotic use.
This study is one of the largest pioneer studies to date to survey sedatives–hypnotics use among community-dwelling elderly. One in five community-dwelling older adults reported sedative–hypnotic drugs use in Taiwan, and about 5% of sedative and/or hypnotics usage was without a doctor's prescription. Findings could be helpful for drug-use safety interventions to identify target geriatric patients who are in general at higher risk of downstream harm associated with sedative–hypnotic use in geriatric patients.
This study was conducted to estimate prevalence rates and risk factors for late-life depression in a large nationwide representative sample from Taiwan.
A total of 5,664, randomly sampled individuals aged ≥55 years were enrolled. Clinically, relevant depressive symptoms were classified using the Center for Epidemiological Studies Depression Scale (CES-D score ≥16), and major depression was confirmed using the Primary Care Evaluation of Mental Disorders. Individuals with clinically relevant depressive symptoms, who did not meet the strict diagnostic criteria for major depression, were considered to have minor depression. Multinomial logistic regression analyses were conducted to identify risk factors for major and minor depression, including socio-demographic characteristics, medical conditions, lifestyle behaviors, social support network, and life events.
The prevalence rates of minor and major depression were 3.7% and 1.5%, respectively. Major depression was associated with personal vulnerability factors, such as poor social support, cognitive impairment, comorbid pain conditions, and sleep disturbance. However, minor depression was more likely to be related to adverse life events, including increased burden on families, changes in health status, or relationship problem. Approximately, 20.0% of individuals with major depression received antidepressant treatment.
Late-life depression was less prevalent among community-dwelling older adults in Taiwan than among populations in other countries. Our findings may aid the early detection and treatment of late-life depression and provide a basis for future investigations.
Two transmission curved crystal spectrometers are designed to measure the hard x-ray emission in the laser fusion experiment of Compton radiography of implosion target on ShenGuang-III laser facility in China. Cylindrically curved
-quartz (10–11) crystals with curvature radii of 150 and 300 mm are used to cover spectral ranges of 10–56 and 17–100 keV, respectively. The distance between the crystal and the x-ray source can be changed over a broad distance from 200 to 1500 mm. The optical design, including the integral reflectivity of the curved crystal, the sensitivity, and the spectral resolution of the spectrometers, is discussed. We also provide mechanic design details and experimental results using a Mo anode x-ray source. High-quality spectra were obtained. We confirmed that the spectral resolution can be improved by increasing the working distance, which is the distance between the recording medium and the Rowland circle.
Video streaming over mobile wireless networks is getting popular in recent years. High video quality relies on large bandwidth provisioning, however, it decreases the number of supported users in wireless networks. Thus, effective bandwidth utilization becomes a crucial issue in wireless network as the bandwidth resource in wireless environment is precious and limited. The NGN quality of service mechanisms should be designed to reduce the impact of traffic burstiness on buffer management. For this reason, we propose an active dropping mechanism to deal with the effective bandwidth utilization in this paper. We use scalable video coding extension of H.264/AVC standard to provide different video quality for users of different levels. In the proposed dropping mechanism, when the network loading exceeds the threshold, the dropping mechanism starts to drop data of the enhancement layers for users of low service level. The dropping probability alters according to the change in network loading. With the dropping mechanism, the base station increases the system capability and users are able to obtain better service quality when the system is under heavy loading. We also design several methods to adjust the threshold value dynamically. By using the proposed mechanism, better quality can be provided when the network is in congestion.
The association between autoimmune diseases and schizophrenia has rarely
been systematically investigated.
To investigate the association between schizophrenia and a variety of
autoimmune diseases and to explore possible gender variation in any such
Taiwan's National Health Insurance Research Database was used to identify
10 811 hospital in-patients with schizophrenia and 108 110 age-matched
controls. Univariate and multiple logistic regression analyses were
performed, separately, to evaluate the association between autoimmune
diseases and schizophrenia. We applied the false discovery rate to
correct for multiple testing.
When compared with the control group, the in-patients with schizophrenia
had an increased risk of Graves' disease (odds ratio (OR) = 1.32, 95% CI
1.04–1.67), psoriasis (OR = 1.48, 95% CI 1.07–2.04), pernicious anaemia
(OR = 1.71, 95% CI 1.04–2.80), celiac disease (OR = 2.43, 95% CI
1.12–5.27) and hypersensitivity vasculitis (OR = 5.00, 95% CI
1.64–15.26), whereas a reverse association with rheumatoid arthritis (OR
= 0.52, 95% CI 0.35–0.76) was also observed. Gender-specific variation
was found for Sjögren syndrome, hereditary haemolytic anaemia, myasthenia
gravis, polymyalgia rheumatica and dermatomyositis.
Schizophrenia was associated with a greater variety of autoimmune
diseases than was anticipated. Further investigation is needed to gain a
better understanding of the aetiology of schizophrenia and autoimmune
InTaO4 is an efficient visible-light photocatalyst, which used to be synthesized by solid-state fusion at over 1100 °C. However, irregular morphology and severe agglomeration of particles were acquired due to nonuniform fusion of solid precursors. In this study, InTaO4 was synthesized by two sol-gel routes, the thermal hydrolysis and esterification methods. The precursors were indium (III) nitrate pentahydrate [In(NO3)3] and tantalum(V) butoxide [Ta(OC4H9)5] dissolved in solutions. The InTaO4 powders with a uniform grain size of 17.7 nm were successfully synthesized using the esterification method at a calcination temperature of 950 °C. A uniform InTaO4 thin film nearly 40 nm thick formed on an optical fiber at 1100 °C using the sol prepared by the esterification method. For the first time, InTaO4 was evaluated by the photocatalytic activity of CO2 photo reduction, which was conducted in aqueous solution under visible light irradiation. Cocatalyst NiO was loaded on the surface of InTaO4 to further enhance the methanol yield. The methanol yields of NiO/InTaO4 by esterification method were significantly higher than those by solid-state fusion. The esterification method provided homogeneous mixing of Ta(OC4H9)5 and In(NO3)3, resulting in nano-sized InTaO4 with uniform crystallinity and superior photocatalytic activity.
To describe the epidemiology of vancomycin-resistant enterococci (VRE) in a university hospital in Taipei, Taiwan.
Retrospective review over a 27-month period, from March 1996 to May 1998.
A tertiary-care teaching hospital in Taiwan.
Patients with VRE isolated from any body site.
Patients were identified through hospital microbiology and infection control records. Patient charts were reviewed for clinical and epidemiology data, including age, gender, previous hospital admissions, underlying diseases, types of infection, and recent antibiotic use. VRE isolates were characterized by their typical biochemical reactions, cellular fatty acid profiles, and the presence of van genes. Antibiotypes using the E-test and randomly amplified polymorphic DNA (RAPD) patterns of these isolates were used to determine the clonality.
Twenty-five isolates of VRE recovered from 12 patients were identified. One patient with a perianal abscess had 12 isolates of VRE (4 Enterococcus faecalis, 7 Enterococcus faecium, and 1 Enterococcus casseliflavus) recovered from perianal lesions. Among 3 patients who were hospitalized in the same room, 1 had a community-acquired cellulitis over the left leg caused by E faecalis, and the other 2 patients both had anal colonization with 2 isolates of E faecalis. The other 8 patients had 1 E faecalis isolate each from various clinical specimens. All isolates possessed vanA resistance phenotype and vanA genes. Different antibiotypes and RAPD patterns of the isolates from different patients excluded the possibility of nosocomial spread at the hospital.
Multiple species of VRE (E faecalis, E faecium, and E casseliflavus) and multiple clones of E faecium could colonize or infect hospitalized patients. In addition, clones of VRE can persist long-term in patients' lower gastrointestinal tracts. These results extend our knowledge of the coexistence and the persistence of multiple species and multiple clones of VRE in hospitalized patients.
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