Kinematic topologies of black holes

We investigate the kinematic topologies of light rings (LRs) and massive particle rings (PRs) encircling spherical and axisymmetric black holes. Our results demonstrate that the global topology number of LRs is consistently -1 for asymptotically flat and (Anti-)de Sitter spacetime. Additionally, we show that the global topology of PRs varies, with a value of 0 in asymptotically flat and Anti-de Sitter spacetime but -1 in asymptotic de Sitter spacetime.Comment: 6 pages, version accepted in PR

Sampling for Remote Estimation of the Wiener Process over an Unreliable Channel

In this paper, we study a sampling problem where a source takes samples from a Wiener process and transmits them through a wireless channel to a remote estimator. Due to channel fading, interference, and potential collisions, the packet transmissions are unreliable and could take random time durations. Our objective is to devise an optimal causal sampling policy that minimizes the long-term average mean square estimation error. This optimal sampling problem is a recursive optimal stopping problem, which is generally quite difficult to solve. However, we prove that the optimal sampling strategy is, in fact, a simple threshold policy where a new sample is taken whenever the instantaneous estimation error exceeds a threshold. This threshold remains a constant value that does not vary over time. By exploring the structure properties of the recursive optimal stopping problem, a low-complexity iterative algorithm is developed to compute the optimal threshold. This work generalizes previous research by incorporating both transmission errors and random transmission times into remote estimation. Numerical simulations are provided to compare our optimal policy with the zero-wait and age-optimal policies.Comment: Accepted by ACM Sigmetrics, will appear in ACM POMACS journa

Review Article From Traditional Usage to Pharmacological Evidence: A Systematic Mini-Review of Spina Gleditsiae

Spina Gleditsiae is an important herb with various medicinal properties in traditional and folk medicinal systems of East Asian countries. In China through the centuries, it has been traditionally used as a source of drugs for anticancer, detoxication, detumescence, apocenosis, and antiparasites effects. Recently, an increasing number of studies have been reported regarding its chemical constituents and pharmacological activities. To further evidence the traditional use, phytochemicals, and pharmacological mechanisms of this herb, a systematic literature review was performed herein for Spina Gleditsiae. The review approach consisted of searching several web-based scientific databases including PubMed, Web of Science, and Elsevier using the keywords "Spina Gleditsiae", "Zao Jiao Ci", and "Gleditsia sinensis". Based on the proposed criteria, 17 articles were evaluated in detail. According to the reviewed data, it is quite evident that Spina Gleditsiae contains a number of bioactive phytochemical components, which account for variety medicinal values including anticancer, anti-inflammatory, antiatherogenic, antimicrobial, antiallergic, and antivirus activities. The phytochemical and pharmacological studies reviewed herein strongly underpin a fundamental understanding of herbal Spina Gleditsiae and support its ongoing clinical uses in China. The further phytochemical evaluation, safety verification, and clinical trials are expected to progress Spina Gleditsiae-based development to finally transform the traditional TCM herb Spina Gleditsiae to the valuable authorized drug

From Traditional Usage to Pharmacological Evidence: A Systematic Mini-Review of Spina Gleditsiae

Spina Gleditsiae is an important herb with various medicinal properties in traditional and folk medicinal systems of East Asian countries. In China through the centuries, it has been traditionally used as a source of drugs for anticancer, detoxication, detumescence, apocenosis, and antiparasites effects. Recently, an increasing number of studies have been reported regarding its chemical constituents and pharmacological activities. To further evidence the traditional use, phytochemicals, and pharmacological mechanisms of this herb, a systematic literature review was performed herein for Spina Gleditsiae. The review approach consisted of searching several web-based scientific databases including PubMed, Web of Science, and Elsevier using the keywords “Spina Gleditsiae”, “Zao Jiao Ci”, and “Gleditsia sinensis”. Based on the proposed criteria, 17 articles were evaluated in detail. According to the reviewed data, it is quite evident that Spina Gleditsiae contains a number of bioactive phytochemical components, which account for variety medicinal values including anticancer, anti-inflammatory, antiatherogenic, antimicrobial, antiallergic, and antivirus activities. The phytochemical and pharmacological studies reviewed herein strongly underpin a fundamental understanding of herbal Spina Gleditsiae and support its ongoing clinical uses in China. The further phytochemical evaluation, safety verification, and clinical trials are expected to progress Spina Gleditsiae-based development to finally transform the traditional TCM herb Spina Gleditsiae to the valuable authorized drug

Effect of Yeast Fermentation on Volatile Flavor Substances and Nutritional Properties of Rice Bran

To investigate the effect of yeast fermentation on the flavor as well as nutritional properties of rice bran. In this study, volatile flavor substances of rice bran at different fermentation periods (0, 12, 18, 24 and 30 h) were identified by headspace solid-phase microextraction-gas chromatography-mass spectrometry, key volatile substances affecting the flavor of rice bran before and after fermentation were determined by orthogonal partial least squares analysis, and finally a comprehensive sensory evaluation of fermented rice bran was carried out and the changes of its nutritional composition by the optimal time of fermentation were compared. The results showed that the content and types of volatile substances of rice bran changed significantly during the fermentation process, the content of aldehydes in unfermented rice bran accounted for 35.99% and the content of alcohols accounted for 14.21%, and the content of aldehydes decreased to 5.52% and the content of alcohols increased to 60.87% at 30 h of fermentation. Among them, there were 15 key volatile substances. In the sensory evaluation, there was a significant (P<0.05, P<0.01) correlation between key volatile substances and rice bran aroma, and the sensory score of rice bran improved after fermentation, and the best sensory score was obtained for rice bran fermented for 18 h. Nonanal and ethyl nonanoate had the most significant (P<0.01) effects on the overall score of rice bran. In terms of nutritional composition, the protein content of yeast fermented rice bran flour was improved by 38.41% and the fiber content was improved by 18.21%. It indicated that yeast fermentation could not only effectively improve the flavor of rice bran, but also enhance the nutritional properties of rice bran flour as a food ingredient

Multifunctional, durable and highly conductive graphene/sponge nanocomposites

Porous functional materials play important roles in a wide variety of growing research and industrial fields. We herein report a simple, effective method to prepare porous functional graphene composites for multi-field applications. Graphene sheets were non-chemically modified by Triton®X-100, not only to maintain high structural integrity but to improve the dispersion of graphene on the pore surface of a sponge. It was found that a graphene/sponge nanocomposite at 0.79 wt.% demonstrated ideal electrical conductivity. The composite materials have high strain sensitivity, stable fatigue performance for 20,000 cycles, short response time of 0.401s and fast response to temperature and pressure. In addition, the composites are effective in monitoring materials deformation and acoustic attenuation with a maximum absorption rate 67.78% and it can be used as electrodes for a supercapacitor with capacitance of 18.1 F/g. Moreover, no expensive materials or complex equipment are required for the composite manufacturing process. This new methodology for the fabrication of multifunctional, durable and highly conductive graphene/sponge nanocomposites hold promise for many other applications

Association of the visceral adiposity index with femur bone mineral density and osteoporosis among the U.S. older adults from NHANES 2005–2020: a cross-sectional study

BackgroundThe visceral adiposity index (VAI) is a marker of abdominal fat distribution and adipose tissue function. However, the association between VAI and femur bone mineral density (BMD) and osteoporosis is unclear among the U.S. older adults.MethodsCross-sectional data for adults aged 60 years and older from the 2007–2020 National Health and Nutrition Examination Survey (NHANES) were included. Multivariable linear and logistic regression were used to evaluate the association between VAI and femur BMD and osteoporosis. We used the smooth curve fitting to address nonlinearity. Moreover, a two-piecewise linear regression model was used to explain the nonlinearity further.ResultsThe findings of the multivariable logistic regression models showed that as the VAI value increased by one unit, the prevalence of osteoporosis decreased by 1.2% after adjusting for covariates associated with osteoporosis. The multivariable linear regression models demonstrated that VAI was positively correlated with femur BMD. Further analysis revealed an inverted L-shaped and inverted U-shaped relationship between VAI and femur BMD at different sites.ConclusionsOur findings indicated that an increased VAI is independently linked to a higher prevalence of osteoporosis among the U.S. older adults. Further analysis reveals that once VAI reaches a certain threshold, femur BMD no longer increases and may even decrease. This suggests that a moderate accumulation of visceral fat may be beneficial for bone health, while excessive visceral fat could potentially have detrimental effects