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In the field of optical communication, laser and its modulation bandwidth and modulation rate are very important for optical wireless communication. There are two main modulation modes for semiconductor laser signal: internal modulation and external modulation. These two modulation technologies have their own characteristics and are suitable for different fields of optical fiber communication. Internal modulation laser, also known as direct modulation laser, has become a cost-effective light source for the Fifth Generation Mobile Communication Technology (5G) fronthaul and data center because of its high-speed transmission and low cost. There is no additional Chirp of light source in external modulation laser, so the Composite Second Beat (CSB) distortion caused by fiber dispersion can be effectively overcomed. On the basis of reviewing the development history of communication laser and its modulation technology, this paper introduces the work and main progress made by Xi’an University of Technology in this field. This paper discusses the internal and external factors of nonlinear distortion of semiconductor laser, simulates the effects of various parameters of response characteristics, linearization compensation method and power control system on the output light source of light emitting device, and analyzes the influence of temperature fluctuation on the output power of laser and modulation device. Based on the basic theory of refractive index ellipsoid and numerical analysis, the variation trend of emitted light intensity with temperature is discussed under the longitudinal and transverse modulation, respectively. The results show that the variation trend of outgoing light intensity with temperature under longitudinal modulation is only related to the refractive index of Lithium Niobate (LN) crystal. Under transverse modulation, the variation trend of outgoing light intensity with temperature is affected not only by the refractive index of the crystal, but also by the crystal size and its expansion coefficient. Therefore, the special size crystal can be used to improve the temperature stability of the electro-optic modulator.

【Objective】Deformable Mirror(DM) is a key device in adaptive optics system for wavefront correction, and its performance directly determines the wavefront correction capability of the system. By studying DM and their control algorithm, the wavefront correction capability of adaptive optics system can be continuously improved. On one hand, the accuracy and response speed of DM can be enhanced to better correct various complex wavefront distortions. On the other hand, the control algorithm can be improved to increase the efficiency and accuracy of the correction. These studies will directly affect the imaging quality and performance of adaptive optics system. Therefore, investigating the DM and their control algorithm is of great significance for improving the wavefront correction capability, expanding application fields, and enhancing imaging quality and performance of adaptive optics system.【Methods】The article aims to summarize the research progress on DM and their control algorithm both domestically and internationally, as well as analyze the correction accuracy of different control algorithm for wavefront distortion, establishing the groundwork for the advancement of adaptive optics. Firstly, several typical DMs are used as examples to model the DM and provide detailed introductions to the structures and working principles of separate actuator DM, splicer DM, thin film DM, dual piezoelectric DM, Micro Electromechanical System (MEMS) DM and voice coil DM. Then, several control algorithms such as the Prandtl-Ishlinskii (PI) hysteresis model-based control algorithm, decoupled control algorithm, and sparse sampling control algorithm are analyzed.【Results】Summarized the work done by Xi'an Technological University in this field, and finally pointed out the future technological breakthroughs and improvement directions in this field.【Conclusion】The research progress on DM and their control algorithm lays the foundation for the development of adaptive optics, enabling its application in more fields and further improving the performance of adaptive optics system. This will help improve imaging quality and drive the development of adaptive optics technology.

Liquid Crystal-Spatial Light Modulators (LC-SLM) control the optical path by modulating the refractive index of liquid crystal, and play an important role in adaptive optics. This paper sorts out the development status of LC-SLM at home and abroad, and introduces the working principle and phase calibration principle of LC-SLM in detail. Aiming at the application of LC-SLM in adaptive optics, the research status of key technologies of LC-SLM at home and abroad is discussed. The experimental research in this field of Xi'an University of Technology is analyzed and summarized. Finally, the application status of LC-SLM is prospected.

【Objective】Coherent optical communication is a high-speed, high-quality, and highly secure communication method, and coherent detection plays an extremely important role in coherent optical communication. High sensitivity coherent detection systems can significantly increase the distance of coherent optical communication. By studying the factors that affect the sensitivity of coherent detection, targeted corrections can be made to improve the detection sensitivity.【Methods】This paper first briefly describes the principle of the coherence detection, and summarizes the research progress in this field at home and abroad. Then the paper analyzes the influence of thermal noise, shot noise, wavefront distortion, polarization loss, spot size deviation, optical axis deflection, coupling efficiency, detector performance, preamplifier and other aspects on coherence detection sensitivity of wireless optical coherence detection system.【Results】The results show that the influence of the thermal noise and shot noise of the system on the detection sensitivity can be minimized by controlling the local oscillator power. The wavefront distortion of signal light can be suppressed by adding an adaptive correction system. The polarization control compensation device can be used to compensate the polarization mismatch between signal light and local oscillator light. The deviation of spot size and optical axis deviation requires improving the processing level of hardware to reduce this error. The use of new detectors can improve the performance of detectors to a certain extent. The pre-amplifier can amplify weak signal light, which is crucial for improving detection sensitivity.【Conclusion】This article analyzes the factors that affect the sensitivity of wireless optical coherent detection, and summarizes the methods used by domestic and foreign scholars to improve detection sensitivity in recent years. It provides theoretical reference for improving the sensitivity of detection systems in practice, which has important significance for improving the performance of coherent optical communication systems.

Objective To independently verify and compare the accuracy of 2 cardiovascular risk prediction models, Framingham model and New Zealand Diabetes Cohort Study (DCS) model in Chinese patients with type 2 diabetes mellitus (T2DM). Methods A total of 48 063 T2DM patients aged from 30 to 74 who had medical records but no cardiovascular diseases (CVD) in the Chinese electronic health records research in Yinzhou (CHERRY) were enrolled from January 1, 2010 to December 31, 2018. Kaplan Meier method was used to calculate the actual risk of CVD in following 5 years, and the recalibrated Framingham model and DCS model were adopted to estimate the predicted 5-year risks of the diseases. The performance of the models was assessed in terms of discrimination and calibration degrees, using C-index and Hosmer-Lemeshow Chi-square value respectively. Results Through a median follow-up of 5.9 years, 2 867 new CVD cases were observed among the subjects. However, both the Framingham and the DCS models underestimated the risk of subjects, by 3.6% (Framingham) and 21.1% (DCS) in males, and by 21.0% (Framingham) and 20.9% (DCS) in females, respectively. For males, the DCS model (C-index=0.716, 95%CI: 0.702~0.730) had a better discriminative ability than the Framingham one (C-index=0.662, 95%CI: 0.648~0.677), though the performance of calibration was not ideal in both models (P < 0.05). For females, C-index was 0.743 in DCS (95%CI: 0.730~0.756) and 0.686 in Framingham models (95%CI: 0.673-0.700), both showing poor performance on calibration (P < 0.05). Conclusion Both Framingham model and DCS model are confirmed inapplicable to CVD risk prediction in Chinese population with T2DM.

In free-space optical communication, the transmission of signal light and beacon light of differing wavelengths through the same atmospheric channel encounters variations in how the atmospheric refractive index absorbs and scatters light. This leads to distinct degrees of wavefront aberrations between the signal and beacon lights. In this study, we employed statistical optics to derive wavefront phase structure functions for both signal and beacon lights under conditions of strong turbulence. We explored how wavefront distortion varies among beams of different wavelengths after propagation through such turbulent conditions. Our findings revealed that as the turbulence outer scale escalates, the difference in wavefront distortion between signal and beacon lights stabilizes after an initial increase, assuming constant wavelengths. Furthermore, we observed significant changes in the relative wavefront aberrations when the inner scale of turbulence surpasses the separation between two points on the receiving apertures. As the disparity in wavelength decreases, so does the difference in wavefront aberrations. Finally, we propose a method for correcting wavefront aberrations based on coefficients of Zernike polynomials corresponding to beams with different wavelengths. This approach is validated through simulation and experimentation, demonstrating an 11% enhancement in the signal-to-optical Strehl ratio and a 0.072 increase in spot energy after the addition of correction coefficients compared with before their inclusion. These results solidify the efficacy of our method in improving adaptive optics correction accuracy. [ABSTRACT FROM AUTHOR]

Four-level pulse amplitude modulation (PAM4) can transmit more information in the same symbol interval, effectively improving the information transmission rate and frequency band utilization of visible light communication (VLC). This paper proposes a method for encoding and decoding the PAM4 signal based on FPGA. The PAM4 signal is studied and analyzed under different channel noise models. The research results show that the bit error rate (BER) performance of the PAM4 signal is the best under the additive noise model. The influence of the multiplicative noise on the BER of the PAM4 signal is much greater than that of the additive noise. The BER performance of the PAM4 signal depends on the variance of the noise data. The greater the variance, the worse the BER performance. At the same time, an indoor VLC system based on PAM4 is designed. The simulation results verify that the system scheme is feasible and provides a way to further realize high-speed signal transmission. [ABSTRACT FROM AUTHOR]

When coherent detection occurs, the polarization mismatch between signal light and local oscillator light can reduce the efficiency of coherent detection. This article combines the principle of optical mixers to derive the relationship between the polarization state and mixing efficiency of signal light and local oscillator light, and builds an experimental platform for the coherent detection of a partially coherent electromagnetic Gaussian Schell beam (EGSM). Polarization devices are used to regulate the polarization state of the signal EGSM light and local oscillator EGSM light, and different polarization states of the EGSM beams are generated. When the output power of the signal light is constant, the mixing efficiency is measured according to the output amplitude of the intermediate frequency signal. This experiment found that when the signal light is in a linearly polarized state and the local oscillator light is in a linearly polarized state, a circularly polarized state, or an elliptically polarized state, the amplitude of the intermediate frequency signal is 369.6 mv, 146.6 mv, or 92.1 mv, respectively. When the signal light is in a circularly polarized state, the amplitude of the intermediate frequency signal is 446.4 mv, 504.0 mv, or 159.2 mv, respectively. When the signal light is in an elliptical polarization state, the amplitude of the intermediate frequency signal is 94.4 mv, 124.0 mv, or 254.8 mv, respectively. [ABSTRACT FROM AUTHOR]

As a gene with antiaging functions, sirtuin6 (SIRT6) belonging to the sirtuin family plays a vital role in DNA repair, telomerase function, and cellular senescence, as well as maintains epigenomic stability and promotes longevity. However, its role in cell senescence in large animals, such as buffaloes, remains unknown. Fibroblasts are commonly used for somatic reprogramming, and their physiological characteristics affect the efficiency of this process. We aimed to elucidate the role of SIRT6 in cellular senescence and proliferation and analyze its effect on the biological function of buffalo fibroblasts to help improve the efficiency of buffalo somatic cell reprogramming. The expression of SIRT6 and related DNA damage was measured in buffalo fibroblasts obtained at different developmental stages (in the fetus and at 3 and 10 years of age), and the effect of SIRT6 knockdown on the senescence of buffalo fetal fibroblast was investigated. An inverse relationship was observed between SIRT6 expression and senescence in buffalo fibroblasts obtained from animals of various ages. This was accompanied by decreased cell growth, viability, and increased DNA damage. Short hairpin RNA-mediated SIRT6 knockdown accelerated the senescence of buffalo fetal fibroblasts. It blocked the cell cycle during in vitro cell culture, which further enhanced DNA damage, particularly with respect to the telomeres. Collectively, our findings suggest that SIRT6 expression was closely associated with buffalo senescence in fibroblasts. These findings serve as a foundation to better understand the cellular functions of SIRT6 and also aid in selecting donor cells for buffalo somatic cell reprogramming. [ABSTRACT FROM AUTHOR]

Wavefront distortion caused by atmospheric turbulence can be described as different types of aberrations, such as piston, tilt, defocusing, astigmatism, coma and so on. The operation of dual deformable mirrors can have mutual coupling effects, which affect the correction effect of wavefront distortion. This study combines a fast-steering mirror (FSM) and a deformable mirror (DM) to form a dual-deformable-mirrors wavefront correction system, and proposes a decoupling algorithm that can correct any specified aberration. In this decoupling algorithm, both the FSM and the DM are controlled using the mode method, and the specific corrected aberrations are obtained based on a limited matrix. The compensation ability of the DM is directly characterized by the mode coefficients of the aberrations, which can achieve independent correction of any order of aberrations and effectively reduce the coupling effect of the dual-deformable-mirrors wavefront correction system. An adaptive optical dual-deformable-mirrors wavefront correction system experiment was built to verify the decoupling algorithm. When the DM corrects the 3rd-, 10th-, and 25th-order aberrations, and the FSM only corrects the 1st- and 2nd-order aberrations, the coupling coefficients are approximately 1.17 × 1 0 − 3 , 1.814 × 1 0 − 2 and 7.81 × 1 0 − 3 , respectively, and their magnitude reaches 10−2 and below 10−2, respectively. The experimental results show that the decoupling algorithm can effectively suppress the coupling effect between the FSM and the DM. [ABSTRACT FROM AUTHOR]

Aiming at the problem of resource allocation strategies limiting the system transmission rate in indoor visible light communication and radio frequency (VLC/RF) systems, a new resource allocation method is proposed, and orthogonal frequency-division multiple access (OFDMA) technology is introduced. The capacity of the communication system is effectively increased. In the VLC/RF system model based on OFDMA, the Lyapunov optimization method is used to transform the time averaging problem into a series of single-slot online problems to reduce its computational complexity, the optimization problem is decomposed into three independent subproblems, and the Lagrange relaxation method and convex optimization theory are used to solve the subproblems to maximize the average transmission rate of the system, and the Lyapunov drift is used to ensure the stability of the system. Simulation verifies that the Lyapunov optimization algorithm does not require iteration, which improves the optimization speed to a high extent. The simulation results show that the proposed resource allocation strategy effectively balances the system queue length and transmission rate, improves the average transmission rate of the system to the greatest extent under the premise of ensuring the stability of the system, and compares with other algorithms from the aspects of system stability and transmission rate, which proves the effectiveness of the Lyapunov optimization algorithm. [ABSTRACT FROM AUTHOR]

To apply visible light communication systems in different scenarios, this article utilizes an excellent temperature-adjustable light source mixed with RGB LEDs and applies it in a visible light communication system. It uses color division multiplexing technology to achieve three-channel communication, thereby improving the communication bandwidth of the system. The communication system adopts three constant current driving circuits to control the duty cycle of Pulse Width Modulation (PWM) of each channel, thereby changing the proportion of RGB LEDs, and obtaining different color temperatures to achieve the purpose of color control for mixed-color LEDs. The experimental results show that when adjusting the color temperature, the change in luminous flux is very small, with fluctuations of less than 2.24%. When adjusting the brightness, the color temperature fluctuation is within 40 K, which is less than the 50 K color temperature limit that the human eye can distinguish, and the average color temperature error is 0.609%. Color tolerance less than 5.5 × 10−3 indicates good dimming effect, and the communication performance of the system is better in the high color temperature range, which is significantly superior to the low color temperature range. When the error rate is below 3.8 × 10−3, the total modulation bandwidth of the three channels reaches 11.7 MHz. [ABSTRACT FROM AUTHOR]

This correction notice addresses two errors in the original publication titled "Experimental Study on Chromaticity Control in Visible Light Communication Systems." The first error is in the legend for Figure 21, which mistakenly labeled the image as an experiment using low-power LEDs instead of high-power LEDs. The second error is regarding the affiliations of the authors, which were listed in the wrong order. The authors assure that these errors do not affect the scientific conclusions of the study. The correction has been approved by the Academic Editor and the original publication has been updated. [Extracted from the article]

In dual-wavelength free-space optical communication systems, the wavefront distortion differences caused by the wavelength difference of the signal and beacon lights cannot be completely corrected. In this study, according to the method of geometric optics, the relationship between the wavefront phases of the signal and beacon lights is analyzed by establishing a mathematical model of the cross-correlation ratio of the arrival-angle fluctuation and phase relationship of different Gaussian-beam wavelengths under weak turbulence near the surface. The numerical results show that after Gaussian beams of different wavelengths propagate through the same atmospheric channel, the cross-correlation number of the arrival-angle fluctuation decreases with an increase in the wavelength difference, waist radius, and turbulence intensity, and increases with an increase in propagation distance. The beam-wavefront phase difference increases with an increasing wavelength difference. Finally, a wavefront distortion correction experiment of a dual-wavelength adaptive optical system verified the correctness of the wavefront phase-difference relationship between the signal light and beacon light established in this study. [ABSTRACT FROM AUTHOR]

Atmospheric turbulence causes signal beam wavefront distortion at the receiving end of a coherent detection system, which decreases the system mixing efficiency. Based on the coherent detection theory, this study establishes a mathematical model of wavefront distortion with mixing efficiency and mixing gain. It also analyzes the improvement limits of wavefront correction on mixing efficiency and mixing gain under different atmospheric turbulence intensities and experimentally measures them. Simulation results show that the mixing efficiency can be improved to 51%, 55%, and 60% after correcting for tilt, defocus, and astigmatism terms, respectively, when turbulence intensity D/r0 is 2. The mixing gain with homodyne detection is 3 dB higher than heterodyne detection. Meanwhile, the wavefront correction orders required for optimal mixing efficiency are higher than the heterodyne correction order. In the experiment, Haso4 NIR + DM 40 was used, and the turbulence intensity D/r0 was 2. After the closed-loop control algorithm corrects the tilt, defocus, and astigmatism terms, the indoor experimental results showed that the mixing efficiency is improved to 36%, 47%, and 62%, respectively. The outdoor experimental results showed that the mixing efficiency improved to 36%, 51%, and 68%, respectively. [ABSTRACT FROM AUTHOR]

In space optical communication, owing to the influence of atmospheric turbulence, optical beams lose focus and become phase-distorted, which reduces the communication quality. Considering the polarization dependence of liquid crystal spatial light modulators and the dispersion effect of liquid crystal materials, the energy utilization rate of liquid crystal adaptive optics systems is low. In this study, a dual liquid crystal spatial light modulator adaptive optics system based on the GS algorithm is used to correct the wavefront distortion of a signal beam under different atmospheric turbulence intensities, and the Strehl ratio (SR) is used as the evaluation index. The simulation results show that the SR of the corrected system can be increased from 0.23, 0.41, and 0.72 to 0.77, 0.89, and 0.95, respectively. The corrected beam spot was more concentrated and the light intensity at the center of the beam spot was stronger. The experimental results show that, after the distortion wavefront is corrected by the dual liquid crystal spatial light modulator, the average gray value of the 10 × 10 pixels in the center of the spot increases from 159.3, 113.1, and 58.4 to 253.4, 247.7, and 198.3, respectively. [ABSTRACT FROM AUTHOR]

In this study, Squalene epoxidase (SQLE) overexpression vector was transfected into bovine skeletal muscle-derived mesenchymal stem/stromal cells (MSCs) to study the molecular mechanism of SQLE regulating meat quality through myogenesis. We initially profiled the expression of SQLE in cattle embryos and adults, in the muscle tissue of four different cattle varieties, and in 11 different tissues/organs of Guangxi cattle variety. Subsequently, we isolated and cultured bovine skeletal muscle-derived MSCs and detected the expression of SQLE during cell proliferation and differentiation. Then, we constructed a bovine SQLE overexpression vector and transfected it into bovine skeletal muscle-derived MSCs by liposome transfection. Cell Counting Kit-8 (CCK-8), 5-ethynyl-20-deoxyuridine (EdU), flow cytometry, immunofluorescence, and quantitative polymerase chain reaction assays were used to characterize cell proliferation and differentiation in detail. The results showed that the relative expression level of bovine SQLE gene in brain tissue was the highest, and in adult muscle tissue was significantly higher than that in embryonic stage. Especially, the expression of SQLE was significantly upregulated in cell differentiation stage. Furthermore, the proliferation, cell cycle, apoptosis, and myoblast differentiation assays indicated that SQLE significantly promoted the differentiation and apoptosis of bovine skeletal muscle-derived MSCs, but inhibited their proliferation. In conclusion, our study reveals the role of SQLE in myoblast differentiation. These results will provide new clues for the regulation network of bovine muscle development. [ABSTRACT FROM AUTHOR]

Erratum corrects a value in Table 1. [ABSTRACT FROM AUTHOR]

The propagation of a laser beam in an underwater environment gives rise to attenuation caused by absorption and scattering as well as fading caused by turbulence. These effects lead to a decrease in light power and fluctuations in light intensity. To account for variations in water velocity, flow direction, and distance in communication links, field measurements were conducted in rivers and ocean nearshore waters. Based on these measurements, a model for an underwater wireless optical channel was developed. Our study involves the measurement and analysis of light intensity fluctuation, loss of received light power, and the structure constant in various underwater regions. Additionally, the investigation examines the variation of the bit-error rate in relation to different signal-to-noise ratios. The results suggest that the river displays attributes of low turbulence, whereas the ocean's nearshore waters exhibit a moderate level of turbulence under the specified circumstances. As the velocity of the water increases, the scintillation index of the received optical signal also increases, indicating a higher degree of signal instability. When transmitting horizontally, the scintillation index of the received optical signal remains unaffected by the direction of water flow. Furthermore, as the distance between the transmitter and receiver increases, the scintillation index of the received optical signal intensifies, indicating a greater level of signal instability. The presence of the external interference factors can increase turbulence intensity. Within a depth range of 60 cm underwater, the turbulence intensity at different depths remains basically unchanged. [ABSTRACT FROM AUTHOR]

Previous studies have found that high social class individuals are more dishonest than low social class ones. However, the underlying mechanism of this phenomenon is still unclear. The “ignoring negative consequences” hypothesis suggests that belonging to a high social class makes individuals ignore the negative consequences of dishonesty, whereas the “self-focused” hypothesis suggests that belonging to a high social class makes individuals focus more on the self and self-interests. The present study aims to examine these two hypotheses by measuring participants’ subjective social class, narcissism, fear of negative evaluation, and tendency to be dishonest. To this end, an online survey was conducted. Results provide evidence for the self-focused hypothesis by showing that subjective social class positively predicts the tendency to be dishonest, and narcissism plays a mediating role in this relationship. [ABSTRACT FROM AUTHOR]

Previous studies showed different risk effects on exposure of fine particulate matter (PM 2.5) mass for cardiovascular disease (CVD) globally, which is likely due to different constituents of PM 2.5. This study aimed to investigate the association between short-term exposure of PM 2.5 constituents and hospital admissions of CVD. Daily counts of city-specific hospital admissions for CVD in 18 cities in China between 2014 and 2017 were extracted from the national Urban Employee Basic Medical Insurance database and the Beijing Municipal Commission of Health and Family Planning Information Center database. Directly measured PM 2.5 constituents, including ions and polycyclic aromatic hydrocarbons, were collected by the Chinese Environmental Public Health Tracking system. We used the time-stratified case-crossover design to estimate the association between PM 2.5 constituents and hospital admissions of CVD. Concentrations of ions accounted for the majority of the detected constituents. Excess risk (ER) of average ions concentrations for CVD was highest as 2.30% (95% CI: 1.62–2.99%) for NH 4 +, whose major sources are residential and agricultural emissions. This was followed by 1.85% (1.30–2.41%) for NO 3 - (generally from vehicles), 0.95% (0.28–1.63%) for SO 4 2- (often from fossil fuel burning) respectively. The association for ions were generally consistent with ischemic heart disease (IHD) and ischemic stroke, e.g., NH 4 + was associated with IHD (2.50%; 1.52–3.48%) and ischemic stroke (1.77%; 0.65–2.9%). For polycyclic aromatic hydrocarbons (PAHs), mainly from coal and vehicle-related oil combustion, the constituents were all associated with ischemic stroke but not for IHD. The ER for ischemic stroke was highest at 1.69% (0.99–2.39%) for indeno (123-cd) pyrene. Thus, in terms of the subtypes of CVD, the risks of hospital admissions varied with exposure to different PM 2.5 constituents. Exposed to NH 4 + had the highest risk to IHD and ischemic stroke, whereas PAHs were predominately associated with ischemic stroke only. • Certain ions were consistently associated with CVD, IHD and ischemic stroke. • PAHs were predominately associated with ischemic stroke only. • Exposed to NH 4 + brought the highest risk of CVD. [ABSTRACT FROM AUTHOR]

Atmospheric turbulence creates a light spot on the focal plane of the receiving end scintillation and angle of arrival fluctuation in optical wireless communication. The combination of a spot centroid detection algorithm and Kalman filter (KF) is proposed for spot tracking. The theoretical calculated value of the spot circle fit is filtered to obtain an optimal estimate of the spot center. The root mean square error of the detected spot centroids is used as an evaluation metric to verify the conventional algorithm and KF algorithm for the real-time tracking of the laser spot at transmission distances of 1.3, 4.1, and 10.3 km. The results show that the root mean square error of the spot in the pitch direction decreases from 0.740, 2.537, and 7.256 pixels to 0.683, 1.792, and 4.756 pixels, respectively, whereas the root mean square error of the spot in the horizontal direction decreases from 0.481, 2.131, and 5.932 pixels to 0.463, 1.471, and 4.362 pixels, respectively, compared with the conventional algorithm at three transmission distances. The envelope fluctuation of the baseband signal at the receiving end is significantly improved using KF algorithm compared with the conventional algorithm, which improves the stability of the optical wireless communication link. [ABSTRACT FROM AUTHOR]

[Display omitted] Evidence for the association between long-term exposure to ozone (O 3) and cause-specific cardiovascular disease (CVD) mortality is inconclusive, and this association has rarely been evaluated at high O 3 concentrations. We aim to evaluate the associations between long-term O 3 exposure and cause-specific CVD mortality in a Chinese population. From 2009 to 2018, 744,882 subjects (median follow-up of 7.72 years) were included in the CHinese Electronic health Records Research in Yinzhou (CHERRY) study. The annual average concentrations of O 3 and fine particulate matter (PM 2.5), which were estimated using grids with a resolution up to 1 × 1 km, were assigned to the community address for each subject. The outcomes were deaths from CVD, ischemic heart disease (IHD), myocardial infarction (MI), stroke, and hemorrhagic/ischemic stroke. Time-varying Cox model adjusted for PM 2.5 and individual-level covariates was used. The mean of annual average O 3 concentrations was 68.05 μg/m3. The adjusted hazard ratio per 10 μg/m3 O 3 increase was 1.22 (95% confidence interval [CI]: 1.13–1.33) for overall CVD mortality, 1.08 (0.91–1.29) for IHD, 1.21 (0.90–1.63) for MI, 1.28 (1.15–1.43) for overall stroke, 1.39 (1.16–1.67) for hemorrhagic stroke and 1.22 (1.00–1.49) for ischemic stroke, respectively. The study showed that subjects without hypertension had a higher risk for CVD mortality associated with long-term O 3 exposure (1.66 vs. 1.15, p = 0.01). We observed the association between long-term exposure to high O 3 concentrations and cause-specific CVD mortality in China, independent of PM 2.5 and other CVD risk factors. This suggested an urgent need to control O 3 pollution, especially in developing countries. [ABSTRACT FROM AUTHOR]

Background: No routinely recommended cardiovascular disease (CVD) risk prediction equations have adjusted for CVD preventive medications initiated during follow-up (treatment drop-in) in their derivation cohorts. This will lead to underestimation of risk when equations are applied in clinical practice if treatment drop-in is common. We aimed to quantify the treatment drop-in in a large contemporary national cohort to determine whether equations are likely to require adjustment., Methods: Eight de-identified individual-level national health administrative datasets in Aotearoa New Zealand were linked to establish a cohort of almost all New Zealanders without CVD and aged 30-74 years in 2006. Individuals dispensing blood-pressure-lowering and/or lipid-lowering medications between 1 July 2006 and 31 December 2006 (baseline dispensing), and in each 6-month period during 12 years' follow-up to 31 December 2018 (follow-up dispensing), were identified. Person-years of treatment drop-in were determined., Results: A total of 1 399 348 (80%) out of the 1 746 695 individuals in the cohort were not dispensed CVD medications at baseline. Blood-pressure-lowering and/or lipid-lowering treatment drop-in accounted for 14% of follow-up time in the group untreated at baseline and increased significantly with increasing predicted baseline 5-year CVD risk (12%, 31%, 34% and 37% in <5%, 5-9%, 10-14% and ≥15% risk groups, respectively) and with increasing age (8% in 30-44 year-olds to 30% in 60-74 year-olds)., Conclusions: CVD preventive treatment drop-in accounted for approximately one-third of follow-up time among participants typically eligible for preventive treatment (≥5% 5-year predicted risk). Equations derived from cohorts with long-term follow-up that do not adjust for treatment drop-in effect will underestimate CVD risk in higher risk individuals and lead to undertreatment. Future CVD risk prediction studies need to address this potential flaw., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Vehicular visible light communications (VVLC) is promising intelligent transportation systems technology with the utilization of light-emitting diodes. The main degrading factor for the performance of VVLC systems is noise. Traditional VVLC systems noise modeling is based on the additive white Gaussian noise assumption in the form of shot and thermal noise. In this paper, to investigate both time correlated and white noise components of the VVLC channel noise, we propose a noise analysis based on Allan variance, which provides a time-series analysis method to identify noise from the data. The results show that white noise and random walk are observed in the VVLC systems. We also propose a motion detection algorithm based on the adaptive Gaussian mixture (GM) model to generate a double Gaussian model of VVLC channel noise. We further present a study on the error performance of a VVLC system considering channel noise to be a mixture of Gaussian components. We derive the analytical expressions of probability of error for binary phase-shift keying and quadrature phase-shift keying constellations. It has been observed that, in the presence of GM noise, the system performance degrades significantly from the usual one expected in a Gaussian noise environment and becomes a function of the mixing coefficients of the GM distribution.

Previous studies showed different risk effects on exposure of fine particulate matter (PM 2.5 ) mass for cardiovascular disease (CVD) globally, which is likely due to different constituents of PM 2.5 . This study aimed to investigate the association between short-term exposure of PM 2.5 constituents and hospital admissions of CVD. Daily counts of city-specific hospital admissions for CVD in 18 cities in China between 2014 and 2017 were extracted from the national Urban Employee Basic Medical Insurance database and the Beijing Municipal Commission of Health and Family Planning Information Center database. Directly measured PM 2.5 constituents, including ions and polycyclic aromatic hydrocarbons, were collected by the Chinese Environmental Public Health Tracking system. We used the time-stratified case-crossover design to estimate the association between PM 2.5 constituents and hospital admissions of CVD. Concentrations of ions accounted for the majority of the detected constituents. Excess risk (ER) of average ions concentrations for CVD was highest as 2.30% (95% CI: 1.62-2.99%) for NH 4 + , whose major sources are residential and agricultural emissions. This was followed by 1.85% (1.30-2.41%) for NO 3 - (generally from vehicles), 0.95% (0.28-1.63%) for SO 4 2- (often from fossil fuel burning) respectively. The association for ions were generally consistent with ischemic heart disease (IHD) and ischemic stroke, e.g., NH 4 + was associated with IHD (2.50%; 1.52-3.48%) and ischemic stroke (1.77%; 0.65-2.9%). For polycyclic aromatic hydrocarbons (PAHs), mainly from coal and vehicle-related oil combustion, the constituents were all associated with ischemic stroke but not for IHD. The ER for ischemic stroke was highest at 1.69% (0.99-2.39%) for indeno (123-cd) pyrene. Thus, in terms of the subtypes of CVD, the risks of hospital admissions varied with exposure to different PM 2.5 constituents. Exposed to NH 4 + had the highest risk to IHD and ischemic stroke, whereas PAHs were predominately associated with ischemic stroke only., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Optical receiving systems with single-lens structures have problems such as low receiving efficiency and small field of view when applied to underwater optical wireless communication systems. In this study, a design scheme for a double-layered fly-eye-lens optical system with wide-angle focusing is proposed. Based on the analysis of the LED light source transmission model and seawater channel, the optical-power receiving equation of the fly-eye lens system is deduced. The fly-eye-lens receiving system was designed and simulated using Zemax according to the geometrical optics principle of the lens array. An experimental device for measuring the insertion loss and receiving efficiency of an underwater blue-green LED communication system was built, and the optical power of the receiving optical system was experimentally measured. For the link distances of 1, 3, and 5 m, the received optical power of the double-layered-compound eye system was higher than that of the single-layered system, with a power increase of 72%, 65%, and 60%, respectively. The results show that the double-layered fly-eye-lens receiving antenna can significantly improve the optical power received by the receiving end; therefore, this antenna structure has strong practicability and good development prospects in the field of underwater optical wireless communication.

Granulosa cells (GCs) are the main supporting cells in follicles and play an important role in the regulation of oocyte maturation and follicular atresia. Accumulating evidence indicates that non-coding RNAs participate in regulation of the physiological function of GCs. However, whole-transcriptome analysis for GCs of buffalo has yet to be reported. In this study, healthy follicles (HFs) and atretic follicles (AFs) were defined according to the apoptosis rate of GCs and the hormone level in follicular fluid. GCs were collected from HFs and AFs ( n = 15, 5 < n < 8 mm) for whole-transcriptome analysis using second-generation high-throughput sequencing. A total of 1,861 and 1,075 mRNAs, 159 and 24 miRNAs, and 123 and 100 lncRNAs, were upregulated and downregulated between HFs and AFs, respectively. Enrichment of functions and signaling pathways of these differentially expressed (DE) genes showed that most of DEmRNAs and targets of DEmiRNAs were annotated to the categories of ECM-receptor interaction and focal adhesion, as well as PI3K-AKT, mTOR, TGF-beta, Rap1, and estrogen signaling pathways. The competing endogenous RNA (CeRNA) network was also constructed based on the ceRNA theory which further revealed regulatory roles of these DERNAs in GCs of buffalo follicles. Finally, we validated that lnc4040 regulated the expression of Hif1a as miR-709 sponge in a ceRNA mechanism, suggesting their critical functions in GCs of buffalo follicles. These results show that lncRNAs are dynamically expressed in GCs of HFs and AFs, and interacting with target genes in a ceRNA manner, suggesting their critical functions in buffalo follicular development and atresia., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Pan, Yang, Cheng, Lv, Xing, Zhang, Liang, Shi and Deng.)