The role of local-geometrical-orders on the growth of dynamic-length-scales in glass-forming liquids

The precise nature of complex structural relaxation as well as an explanation for the precipitous growth of relaxation time in cooling glass-forming liquids are essential to the understanding of vitrification of liquids. The dramatic increase of relaxation time is believed to be caused by the growth of one or more correlation lengths, which has received much attention recently. Here, we report a direct link between the growth of a specific local-geometrical-order and an increase of dynamic-length-scale as the atomic dynamics in metallic glass-forming liquids slow down. Although several types of local geometrical-orders are present in these metallic liquids, the growth of icosahedral ordering is found to be directly related to the increase of the dynamic-length-scale. This finding suggests an intriguing scenario that the transient icosahedral ordering could be the origin of the dynamic-length-scale in metallic glass-forming liquids.Comment: 15 pages, 3 Figure

Association of blood pressure with development of metabolic syndrome components: a five-year retrospective cohort study in Beijing

Background: Raised blood pressure (BP) is associated with the incidence of metabolic syndrome (MetS). It is unknown if subjects with different BP levels may develop certain components of MetS over time. We investigated the incidence of MetS relative to different levels of BP over a 5-year period in a Chinese population in Tongren Hospital, Beijing. Methods: During the period of 2006–2011, we recruited 2,781 participants with no MetS, or self-reported type 2 diabetes, dyslipidemia, hypertension, or cardiovascular disease at baseline. Association rule was used to identify the transitions of MetS components over time. Results: The incidence of MetS at follow-up was 9.74% for men and 3.21% for women in the group with optimal BP; 10.29% and 7.22%, respectively, in the group with normal BP; 10.49% and 10.84%, respectively, in the group with high-normal BP; and 14.48% and 23.21%, respectively in the group with high BP. The most common transition was from healthy to healthy in the groups with optimal or normal BP (17.9–49.3%), whereas in the high-normal BP group, 16.9-22.1% of subjects with raised BP returned to healthy status or stayed unchanged, while 13.8-21.4% of people with high BP tended to develop raised fasting glucose levels. Conclusions: The incidence of MetS increased in parallel with the increase in BP. People with optimal and normal BP levels were less susceptible to developing MetS over time, whereas abnormal BP seemed to be a pre-existing phase of MetS. High-normal BP was a crucial status for MetS prevention

Object Detection Through Exploration With A Foveated Visual Field

We present a foveated object detector (FOD) as a biologically-inspired alternative to the sliding window (SW) approach which is the dominant method of search in computer vision object detection. Similar to the human visual system, the FOD has higher resolution at the fovea and lower resolution at the visual periphery. Consequently, more computational resources are allocated at the fovea and relatively fewer at the periphery. The FOD processes the entire scene, uses retino-specific object detection classifiers to guide eye movements, aligns its fovea with regions of interest in the input image and integrates observations across multiple fixations. Our approach combines modern object detectors from computer vision with a recent model of peripheral pooling regions found at the V1 layer of the human visual system. We assessed various eye movement strategies on the PASCAL VOC 2007 dataset and show that the FOD performs on par with the SW detector while bringing significant computational cost savings.Comment: An extended version of this manuscript was published in PLOS Computational Biology (October 2017) at https://doi.org/10.1371/journal.pcbi.100574

High performance CaCO₃-based composites using sodium tripolyphosphate as phase controlling additive:Bamboo fiber driven high strength development

Due to the limited carbonation degree caused by the surface densification of carbonated products, the development of high-strength carbonated composites remains challenging. In this work, bamboo fiber (BFs) is utilized as a reaction reinforcing agent along with sodium tripolyphosphate (STPP) as a CaCO3 phase controlling additive to prepare high-strength bamboo fiber reinforced carbonated wollastonite composites (BFRCWs). The phase composition and microstructure are systematically investigated by multiscale physicochemical analysis, followed by the determination of macro properties and volume deformation. Results indicate that BF and STPP have a synergistic effect on the microstructural formation and macro performance of BFRCWs. STPP-treated BF (ST-BF) can serve as an internal curing agent and the porous structure of BF provides more channels for ion and CO2 transport, whereas CaCO3 phase composition and cementitious behavior is modified by STPP. The addition of ST-BF, particularly for long fibers, accelerates the carbonation reaction, resulting in an increased ratio of poorly crystalline CaCO3 and a refined pore structure. With increasing ST-BF dosage (0–3 vol%), the cementitious reaction is enhanced, but excessive fibers (3 vol%) incorporation introduces additional porosity, consequently reducing compressive strength. The desired pore structure with the optimal 2 vol% ST-BF (3–6 mm) shows the highest strength of 103.5 MPa at 28 days.</p

Effects of relative humidity on carbonation kinetics and strength development of carbonated wollastonite composites containing sodium tripolyphosphate

Assessing the impact of relative humidity (RH) on carbonation kinetics is crucial for the sustainable and high-strength advancement of CO2-activated Ca-bearing materials incorporating phase-controlling additives. This work focuses on the carbonation kinetics, mechanical properties, and microstructure evolution of carbonated wollastonite composites containing sodium tripolyphosphate (STPP) when exposed to various RH levels. Results show that RH plays an important role during the carbonation of wollastonite, functioning both as a reaction material and accelerating role for wollastonite carbonation. The carbonation rate and the phase transition reaction of poorly crystalline CaCO3 is accelerated at RH ranging from 70% to 95%, favouring to cementitious behaviour of CaCO3 and results in denser microstructure, especially for 85% RH. The carbonation reaction is composed of two distinct stages, namely, wollastonite dissolution and precipitation of the stage-1 and ion-diffusion controlling of stage-2. Among them, the addition of STPP prolong the carbonation duration of stage-1. The degree of carbonation (DOC) of the internal layer sample is higher than that of the outermost layer sample. CaCO3 and silica gel are evenly distributed indirectly, which reduces the elastic modulus at 85 % RH. However, regardless of RH, the cementitious efficiency of poorly crystalline CaCO3 is the highest, followed by calcite and silica gel. Consequently, STPP modified carbonated wollastonite shows highest strength when exposed to 85% RH (67.3 MPa at 7 days). Our study provides a unique way toward developing the STPP-containing carbonated wollastonite system for high performance carbonated materials.</p

Arginine and antioxidant supplement on performance in elderly male cyclists: a randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>Human exercise capacity declines with advancing age. These changes often result in loss of physical fitness and more rapid senescence. Nitric oxide (NO) has been implicated in improvement of exercise capacity through vascular smooth muscle relaxation in both coronary and skeletal muscle arteries, as well as via independent mechanisms. Antioxidants may prevent nitric oxide inactivation by oxygen free radicals. The purpose of this study was to investigate the effects of an L-arginine and antioxidant supplement on exercise performance in elderly male cyclists.</p> <p>Methods</p> <p>This was a two-arm prospectively randomized double-blinded and placebo-controlled trial. Sixteen male cyclists were randomized to receive either a proprietary supplement (Niteworks^®, Herbalife International Inc., Century City, CA) or a placebo powder. Exercise parameters were assessed by maximal incremental exercise testing performed on a stationary cycle ergometer using breath-by-breath analysis at baseline, week one and week three.</p> <p>Results</p> <p>There was no difference between baseline exercise parameters. In the supplemented group, anaerobic threshold increased by 16.7% (2.38 ± 0.18 L/min, p < 0.01) at week 1, and the effect was sustained by week 3 with a 14.2% (2.33 ± 0.44 L/min, p < 0.01). In the control group, there was no change in anaerobic threshold at weeks 1 and 3 compared to baseline (1.88 ± 0.20 L/min at week 1, and 1.86 ± 0.21 L/min at week 3). The anaerobic threshold for the supplement groups was significantly higher than that of placebo group at week 1 and week 3. There were no significant changes noted in VO₂max between control and intervention groups at either week 1 or week 3 by comparison to baseline.</p> <p>Conclusion</p> <p>An arginine and antioxidant-containing supplement increased the anaerobic threshold at both week one and week three in elderly cyclists. No effect on VO₂max was observed. This study indicated a potential role of L-arginine and antioxidant supplementation in improving exercise performance in elderly.</p

Association Between Physical Activity and Prevalence/Mortality of Non-Alcoholic Fatty Liver Disease in Different Socioeconomic Settings

Objectives: We aimed to investigate the effect of physical activity (PA) on non-alcoholic fatty liver disease (NAFLD) prevalence and long-term survival, particularly in some specific population such as those with different socioeconomic status (SES).Methods: Multivariate regression and interaction analyses were conducted to deal with confounders and interacting factors.Results: Active PA was associated with lower prevalence of NAFLD in both cohorts. Individuals with active-PA had better long-term survival compared to those with inactive-PA in both cohorts, and the results were only statistically significant in NAFLD defined by US fatty liver index (USFLI). We found clear evidence that the beneficial role of PA was more obvious in individuals with better SES, and the statistical significances were presented in both two hepatic steatosis index (HSI)-NAFLD cohorts from the NHANES III and NHANES 1999–2014. Results were consistent in all sensitivity analyses.Conclusion: We demonstrated the importance of PA in decrease the prevalence and mortality of NAFLD, and highlights the need for improving SES simultaneously to increase the protective effect of PA

Staged characteristics analysis of a severe convection over the Dongting Lake area based on dual-polarization Doppler weather radar data

The multi-cell storm stage and squall line stage of a severe convective weather process over the Dongting Lake on 15 May 2021 in this study are analyzed mainly based on S-band dual-polarized doppler weather radar data. The study focuses on the analysis of the supercell storm I2 in the multi-cell storm stage. The results are as follows. (1) During the initial period of the I2, the strong echo area (the horizontal reflectivity factor, ZH > 55 dBz) and the differential reflectivity factor (ZDR) column (ZDR > 2.5 dB) extend to Wet Blub Zero (WBZ) level, corresponding to the areas with large specific differential phase (KDP) (> 1.7 °·km-1) and large correlation coefficient (CC) (0.9-0.99). It indicates that during this period, the precipitation phase is dominated by water condensate mingled with large raindrops, and these supercooled raindrops provide hail embryos for the later hail development. (2) During the hail colliding-growth period of the I2, ZH intensity and height increase rapidly, and vertically integrated liquid water content (VIL) shows an obvious leap increase. The strong-echo center (ZH > 60 dBz) extends to the level of above -10 ℃. In the corresponding regions, the ZDR drops below 0, the ZDR column (ZDR> 2.5 dB) extends to the level of -10 ℃, CC drops, and a "hole" appears in the KDP value area. These indicate that the precipitation during this period is dominated by solid particles and these solid particles are in an increasing period. (3) During the mature hailfall period of the I2, the bottom of the ZH intensity center (ZH > 60 dBz) drops below the WBZ level and the CC is locally as low as 0.8. There are ZDR negative areas and KDP voids in the corresponding area. These means that the dragging effect of the falling hail further weakens the strength of the updraft, which means that the hail is about to land. Then comes the squall line stage. (4) Unlike the multi-cell storm stage, the squall line stage has anomalously large KDP values and ZDR values greater than 1. (5) Before the occurrence of extreme gales of the squall line stage, the areas with strong echo greater than 55 dBz and velocity larger than 27 m·s-1 extend below 1 km, and the KDP in the strong echo area is obviously large, corresponding to the strong downdraft. Besides, the strong precipitation dragging effect caused by the melting of descending precipitation particles intensifies the generation of extreme gales

Association between γ-glutamyl transferase and metabolic syndrome: A cross-sectional study of an adult population in Beijing

The relationship between liver enzymes and clustered components of metabolic syndrome (MetS) is explored and the predictive power of γ-glutamyl transferase (GGT) for the diagnosis of MetS in an adult population in Beijing is investigated. A total of 10,553 adults aged 20-65 years who underwent health examinations at Beijing Tongren Hospital in 2012 were enrolled in the study. Multivariate logistic regression analysis is conducted to determine the associations between the levels of various liver enzymes and clustered components of MetS. A receiver operating characteristic analysis is used to determine the optimal cut-off value of GGT for the diagnosis of MetS. A high level of GGT is found to be positively associated with clustered components of MetS in both men and women after adjusting for age, body mass index (BMI), history of alcoholic fatty liver, and the presence of taking anti-hypertensive, anti-dyslipidemic, and anti-diabetic drugs. Among all components of MetS, GGT is more predictive of triglyceride, and BMI. The area-under-the-curve values of GGT for discriminating MetS from normal metabolic status in men and women are 0.73 and 0.80, respectively. The optimal cut-off value of GGT for men is 31.50 U/L, demonstrating a sensitivity of 74.00% and specificity of 62.00%. For women, it is 19.50 U/L (sensitivity 76.00% and specificity 70.00%). GGT is therefore recommended as a useful diagnostic marker for MetS, because the test is inexpensive, highly sensitive, and frequently encountered in clinical practice