492 research outputs found
Quantum entangled Sagnac interferometer
SU(1,1) interferometer (SUI) is a novel type of interferometer that uses
directly entangled quantum fields for sensing phase change. For rotational
sensing, Sagnac geometry is usually adopted. However, because SUI depends on
the phase sum of the two arms, traditional Sagnac geometry, when applied to
SUI, will result in null signal. In this paper, we modify the traditional
Sagnac interferometer by nesting SU(1,1) interferometers inside. We show that
the rotational signal comes from two parts labeled as "classical" and
"quantum", respectively, and the quantum part, where quantum entangled fields
are used for sensing, has rotational signal enhanced by a factor related to the
gain of the SUI.Comment: 5 pages, 3 figure
Prevalence and influencing factors of chronic pain in middle-aged and older adults in China: results of a nationally representative survey
BackgroundWith China's rapidly aging population, chronic pain has become a major public health issue. This article aims at determining associations between chronic pain and multiple factors, including demographic characteristics, health status, and health service utilization of middle-aged and older adults in China.MethodsWe selected all the 19,829 respondents who were over 45 years old from the China Health and Aging Tracking Survey 2018 (CHARLS) as our study population. The key information in terms of the body pain, demographic characteristics, health status, behaviors and health services use was extracted and analyzed. Logistic regression model was used to determine the influencing factors of chronic pain.ResultsAnalysis revealed that 60.02% (9,257) of the data from this survey reported physical pain, with pain sites concentrated at the head (40.9%), lower back (62.2%) and knees (47.2%). Pain was positively associated with influencing factors for pain: being a female (OR = 2.10, 95% CI 1.90–2.33, p < 0.001), living in a western region (OR = 1.28, 95% CI 1.16–1.41, p < 0.001), living in a rural area (OR = 1.14, 95% CI 1.06–1.23, p < 0.001), smoked (OR = 1.26, 95% CI 1.14–1.38, p < 0.001), drank alcohol (OR = 1.16, 95% CI 1.06–1.26, p = 0.001), and had poor self-rated health (OR = 6.84, 95% CI 5.41–8.65, p < 0.001), had hearing problems (OR = 1.23, 95% CI 1.11–3.37, p < 0.001), were depressed (OR = 1.56, 95% CI 1.03–1.29, p < 0.001), had arthritis (OR = 2.21, 95% CI 2.02–2.41, p < 0.001), stomach disorders (OR = 1.69, 95% CI 1.55–1.85, p < 0.001), visited a Western medicine hospital (OR = 1.28, 95% CI 1.10–1.50, p = 0.002), and visits to other medical institutions (OR = 1.42, 95%CI 1.22–1.64, p < 0.001). On the other side, as a protective factor for pain, having nighttime sleep ≥7 h (OR = 0.74, 95%CI 0.68–0.80, p < 0.001) was negatively associated with pain.ConclusionPhysical pain affects many older adults. Women, regional, rural residents, smokers, alcohol drinkers, people with poor self-rated health, those having <7 h of sleep at night, those with hearing problems, depression, arthritis, stomach disorders, and people who visits Western hospitals or other medical institutions are at greater risk for pain and deserve the attention of health care providers and policy makers to focus on pain prevention and management in middle-aged and older adults. Future research studies should also focus on the impact of health literacy on pain prevention and management outcomes
Linearly Sweeping Leaky-Wave Antenna with High Scanning Rate
Leaky wave antenna is known as a type of travelling antenna with dispersive frequency responses, which has found important applications in modern communication, imaging and radar systems. The beam scanning rate is a key consideration in some applications, since it can minimize the bandwidth requirement of the system, during the scanning in broad angular regions. However, the sweeping linearity, namely the scanning angular range per unit frequency, is seldom taken into account at the same time in the published literature. In this article, we propose a waveguide-type leaky-wave antenna working from 11.1 GHz to 12 GHz. By loading periodical pins with glide symmetry in the waveguide, it is possible to manipulate the dispersion properties of the fast wave mode, hereby giving rise to a good balance between the scanning rate and sweeping linearity. This scenario has been validated by numerical simulation and experiment with excellent agreement. The measurement results reveal that the scanning angles have been increased to range from 16.7° ~67.5° varying the frequency from 11.1 to 12.1 GHz. The relative average scanning rate is enhanced up to 589.3°, with high sweeping linearity
Broadband Bioimpedance Spectroscopy Based on a Multifrequency Mixed Excitation and Nuttall Windowed FFT Algorithm
Bioimpedance spectroscopy (BIS) has become an important clinical indicator for monitoring the pathological status of biological tissues, and multifrequency simultaneous measurement of BIS may provide more accurate diagnostic information compared with the traditional frequency-sweep measurement technology. This paper proposes a BIS multifrequency simultaneous measurement method based on multifrequency mixed (MFM) signal excitation and a Nuttall windowed interpolation FFT algorithm. Firstly, the excitation source adopts the nine-frequency MFM signal f(9,t), which has excellent spectral characteristic and is very suitable for BIS measurement. On this basis, a Nuttall window is adopted to truncate sample data, and an interpolation FFT algorithm based on Nuttall window is built to perform spectral analysis, in which the parameter correction formula is provided based on polynomial approximation. A BIS measurement simulation experiment is performed on an RC three-element equivalent circuit, and results on the 9 primary harmonic frequencies ranging from 3.9 kHz to 1 MHz show a high accuracy with the impedance amplitude relative error |Ez|<0.3%, and the phase absolute error |Ep|<0.1°. This paper validates the feasibility of BIS multifrequency simultaneous measurement method and establishes an algorithm foundation for the development of practical broadband BIS measurement system
Examining the impact of chronic diseases on activities of daily living of middle-aged and older adults aged 45 years and above in China: a nationally representative cohort study
BackgroundChina has by far one of the fastest-aging populations in the world. Increasing age is often accompanied by an increasing prevalence of chronic diseases and impaired Activities of Daily Living (ADL). The aim of this study was to analyze the effects of chronic diseases on ADL in Chinese middle-aged and older adults and to provide a scientific basis for delaying the impairment of ADL and prolonging the self-care life expectancy of middle-aged and older adults.MethodsThis investigation utilized the survey information of 10,096 middle-aged and older adults from the China Health and Aging Tracking Survey (CHARLS) of 2011 as baseline data, then followed up this cohort until 2018, and performed multifactorial analyses using Cox proportional risk models to explore the strength of the associations between chronic diseases and the risk of impaired ADL in middle-aged and older adults.ResultsAmong the middle-aged and older adult population, the presence of hypertension was associated with a 38% higher risk of impaired ADL compared to those without the condition (HR = 1.38,95% CI:1.24–1.54); the involvement of heart disease was associated with a 27% higher risk of impaired ADL compared to those without the condition (HR = 1.27,95% CI:1.10- 1.46); the existence of arthritis was associated with a 38% higher risk of impaired ADL in middle-aged and older adults compared to those without arthritis (HR = 1.38,95% CI:1.25–2.08); additionally, the risk of impaired ADL with one or ≥ 2 chronic diseases was increased by 34% (HR = 1.34, 95% CI:1.18–1.52) and 84% (HR = 1.84, 95% CI:1.63–2.08) in middle-aged and older adult individuals, respectively.ConclusionHypertension is a risk factor for impaired ADL at any age in the subjects of this study. Examining the association between the number of chronic diseases and impairment in activities of daily living, it was revealed that the risk of ADL impairment increased with the number of chronic diseases in both the middle-aged (45–59 years) and older adult (60–74 years) groups
Changes of optic nerve head microcirculation in high myopia
AIM: To analyze the correlation of age, spherical equivalent (SE), and axial length (AL) with the microcirculation of optic nerve head (ONH) in high myopia (HM). METHODS: In this cross-sectional clinical study, 164 right eyes were included. Optical coherence tomography angiography (OCTA) was used to detect ONH vessel density. Eyes were classified based on age, SE, and AL. Groups of Age1, Age2, and Age3 were denoted for age classification (Age10.05) and the SE1, SE2, and SE3 groups (all P>0.05). No significant difference was observed in the intrapapillary vascular density (IVD) among AL1, AL2, AL3, and AL4 groups (P>0.05). However, a significant decrease was found in the peripapillary vascular density (PVD) in the AL1, AL2, AL3, and AL4 groups (F=3.605, P=0.015), especially in the inferotemporal (IT; F=6.25, P0.05). The PVD was correlated with AL (r=-0.236, P0.05). CONCLUSION: With the increase of AL, the IVD remains stable while the PVD decreases, especially in the three directions of temporal (IT, TI, and TS). The main cause of microcirculation reduction may be related to AL elongation rather than an increase in age or SE
A frequency domain view on diffusion-based molecular communication channels
Molecular communication (MC) is an emerging communication paradigm, where the information is carried via the patterns of molecules that are mainly governed by the diffusion process. Current MC literature concentrates on the time-domain analysis, while the signal analysis in other domains may facilitate the MC research. To this end, this paper performs the frequency-domain analysis by deriving the frequency response of the diffusion-based MC channels, manifesting an explicitly low-compass characteristic. The energy of the channel impulse response in the diffusion-based MC is also derived, and the corresponding bandwidth definition is proposed, which determines the sampling frequency for the one-shot diffusive channel impulse response in MC. The results in this work lay the foundation for the frequency-domain signal processing in diffusion-based MC channels
Are CD4+CD25-Foxp3+ cells in untreated new-onset lupus patients regulatory T cells?
Introduction: Our previous study has reported that, in patients with untreated new-onset lupus (UNOL), there was an abnormal increase in the number of CD4CD25Foxp3T cells that correlated with disease activity and significantly decreased after treatment. However, little is known about the nature of this cell entity. The aim of this study was to explore the nature of abnormally increased CD4CD25Foxp3T cells in UNOL patients.Methods: The expressions of surface (CD4, CD25, CD127, chemokine receptor 4 [CCR4], glucocorticoid-induced tumor necrosis factor receptor [GITR], and cytotoxic T lymphocyte-associated antigen 4 [CTLA-4]) and intracellular (Foxp3) molecules as well as cytokine synthesis of peripheral blood mononuclear cells from 22 UNOL patients were analyzed by flow cytometry. The proliferative and suppressive capacities of different T-cell subgroups from UNOL patients were also assessed.Results: In UNOL patients, the percentages of CD127in CD25, CD25, and CD25subpopulations of CD4Foxp3T cells were 93.79% ± 3.48%, 93.66% ± 2.31%, and 91.98% ± 2.14%, respectively (P > 0.05), whereas the expressions of Foxp3 showed significant differences in CD25(91.38% ± 2.57%), CD25(71.89% ± 3.31%), and CD25(9.02% ± 2.21%) subpopulations of CD4CD127T cells (P < 0.01). The expressions of surface CCR4, GITR, and CTLA-4 on CD4CD25Foxp3T cells were significantly less than CD4CD25Foxp3T cells (P < 0.05). Moreover, unlike CD4CD25Foxp3T cells, CD4CD25Foxp3T cells also synthesized interferon-gamma, interleukin (IL)-4, IL-2, and IL-17 (P < 0.05), though less than CD4CD25Foxp3T cells. The suppressive capacity was most prominent in CD4CD25CD127, followed by CD4CD25CD127. CD4CD25CD127T cells showed the least suppressive capacity, which was similar to the effector T cells.Conclusions: CD4CD25Foxp3T cells in UNOL patients are different from regulatory T cells, both phenotypically and functionally. CD127 is not an appropriate surface marker for intracellular Foxp3 in CD4CD25T cells
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