Summary
Root exudation stimulates microbial decomposition and enhances nutrient availability to plants. It remains difficult to measure and predict this carbon flux in natural conditions, especially ...for mature woody plants. Based on a known conceptual framework of root functional traits coordination, we proposed that root functional traits may predict root exudation.
We measured root exudation and other seven root morphological/chemical/physiological traits for 18 coexisting woody species in a deciduous‐evergreen mixed forest in subtropical China.
Root exudation, respiration, diameter and nitrogen (N) concentration all exhibited significant phylogenetic signals. We found that root exudation positively correlated with competitive traits (root respiration, N concentration) and negatively with a conservative trait (root tissue density). Furthermore, these relationships were independent of phylogenetic signals. A principal component analysis showed that root exudation and morphological traits loaded on two perpendicular axes.
Root exudation is a competitive trait in a multidimensional fine‐root functional coordination. The metabolic dimension on which root exudation loaded was relatively independent of the morphological dimension, indicating that increasing nutrient availability by root exudation might be a complementary strategy for plant nutrient acquisition. The positive relationship between root exudation and root respiration and N concentration is a promising approach for the future prediction of root exudation.
Time synchronization is crucial for effective collaboration among underwater sensors. However, existing synchronization protocols primarily cater to low-speed or simple motion scenarios, neglecting ...variations in radial velocity during message propagation. A novel Doppler compensation time synchronization scheme, called DC-Sync, was developed in this study to address this issue by targeting complex moving underwater sensors. DC-Sync includes a practical Doppler compensation and estimation method. Simulation results demonstrate that when the target motion follows a specific pattern, DC-Sync outperforms existing similar schemes in terms of time skew and time offset accuracy. Furthermore, the scheme maintains high estimation accuracy even with incomplete Doppler measurement values. Its performance was also validated through physical experiments.
Objective
MiR-499 has been reported to be expressed only in cardiomyocytes, and its expression would increase after acute myocardial infarction (AMI). miR-499 plays a role in the process of ...cardiomyocytes injury induced by hypoxia/reoxygenation (H/R), however, it still remains unclear.
Results
Hypoxia inhibited miR-499-5p expression and H/R induced apoptosis. SOX6 was a target gene of miR-499-5p, and high expression of miR-499-5p inhibited the expression of SOX6. MiR-499-5p reduced H9c2 cells injury by inhibiting the expression of SOX6, overexpression of which could reverse the effect of miR-499-5p on H9c2 cells. MiR-499-5p inhibited the levels of LDH and MDA, while overexpression of miR-499-5p inhibited H/R-induced cell apoptosis. MiR-499-5p could up-regulate the level of Bcl-2 and down-regulate the expression levels of Bax and caspase-3. However, SOX6 partially reversed these effects of miR-499-5p.
Conclusion
We proved that miR-499-5p inhibited H/R-induced cardiomyocytes injury by targeting SOX6. Our results suggested that miR-499-5p/SOX6 pathway may present a potential therapeutic target for the treatment of AMI.
Tree roots not only acquire readily‐usable soil nutrients but also affect microbial decomposition and manipulate nutrient availability in their surrounding soils, that is, rhizosphere effects (REs). ...Thus, REs challenge the basic understanding of how plants adapt to the environment and co‐exist with other species. Yet, how REs vary among species in response to species‐specific bulk soil nutrient cycling is not well‐known. Here, we studied how plant‐controlled microbial decomposition activities in rhizosphere soils respond to those in their corresponding bulk soils and whether these relations depend on species‐specific nutrient cycling in the bulk soils. We targeted 55 woody species of different clades and mycorrhizal types in three contrasting biomes, namely a temperate forest, a subtropical forest, and a tropical forest. We found that microbial decomposition activities in rhizosphere soils responded linearly to those in their corresponding bulk soils at the species level. Thereafter, we found that REs (parameters in rhizosphere soils minus those in corresponding bulk soils) of microbial decomposition activities had negative linear correlations with microbial decomposition activities in corresponding bulk soils. A multiple factor analysis revealed that soil organic carbon, total nitrogen, and soil water content favored bulk soil decomposition activities in all three biomes, showing that the magnitude of REs varied along a fast‐slow nutrient cycling spectrum in bulk soils. The species of fast nutrient cycling in their bulk soils tended to have smaller or even negative REs. Therefore, woody plants commonly utilize both positive and negative REs as a nutrient‐acquisition strategy. Based on the trade‐offs between REs and other nutrient‐acquisition strategies, we proposed a push and pull conceptual model which can bring plant nutrient‐acquisition cost and plant carbon economics spectrum together in the future. This model will facilitate not only the carbon and nutrient cycling but also the mechanisms of species co‐existence in forest ecosystems.
ObjectivesThis study aimed to investigate the knowledge–attitude–practice (KAP) of Chinese college students regarding COVID-19 and evaluate their psychological status against the background of the ...COVID-19 outbreak.DesignThis was a cross-sectional study.SettingThis study covered 31 provinces, municipalities and autonomous regions of mainland China.ParticipantsThe participants, who were college students with ordinary full-time status, were surveyed anonymously on their KAP regarding COVID-19 by using self-made questionnaires. In addition, the Self-Rating Anxiety Scale was used to assess the psychological status of the students.MethodsThe online cross-sectional study among Chinese college students was conducted in February 2020. Logistic regression analysis was used to analyse the predictors of anxiety symptoms.Primary outcome measuresThe level of KAP and anxiety symptoms.ResultsA total of 740 college students from 31 provinces, municipalities and autonomous regions in China were recruited in the survey. Among them, 139 (18.78%) revealed having anxiety. Multivariable logistic regression analysis revealed that female gender was the risk factor for anxiety symptoms with an increased 2.164-fold risk than male gender (OR=2.164, 95% CI=1.279 to 3.662). The knowledge (OR=0.825, 95% CI=0.779 to 0.873) and attitude (OR=0.822, 95% CI=0.762 to 0.887) regarding COVID-19 were protective factors against anxiety symptoms.ConclusionsThe level of KAP regarding COVID-19 was significantly negatively correlated with anxiety symptoms. Thus, understanding the level of KAP among college students during the early stages of major public health emergencies, such as a pandemic, is important. Such understanding plays an important role in adopting targeted health education strategies and reducing the psychological damage caused by these emergencies.
The construction of underwater geodetic networks (UGN) is crucial in marine geodesy. To provide high-precision kinematic positioning for underwater submersibles, an underwater acoustic geodetic ...network configuration of three seafloor base stations, one subsurface buoy, and one sea surface buoy is proposed. The simulation results show that, for a 3 km-deep sea, based on the proposed UGN, the submersible positioning range and positioning accuracy are primarily affected by the size of the seafloor base station array, while the height of the subsurface buoy has a greater impact on the submersible positioning accuracy than the positioning range. Considering current acoustic ranging technology, the kinematic positioning performance of the UGN is optimal when the seafloor base stations are 9~13 km apart and the subsurface buoy is less than 2.5 km above the seafloor, which can achieve a submersible positioning accuracy of less than 30 m within an underwater space of 25 km × 25 km × 3 km. The proposed cost-effective UGN configuration can provide high-precision submersible kinematic positioning performance for seafloor surveying and ocean precision engineering. The impact of the underwater environment on the acoustic transmission characteristics should be further investigated.
Formulae of estimated glomerular filtration rate (eGFR) based on serum creatinine (Scr) are routinely used in oncology patients, however, they are inaccurate in some populations. Our aim was to ...assess the agreement of eGFR formulae and thereby build a nomogram to predict the reliability of estimates.
Measured GFR (mGFR) using isotope from 445 oncology patients were compared with eGFR from six formulae (Cockcroft-Gault, Modification of Diet in Renal Disease (MDRD), modified MDRD formulae for Chinese (C-MDRD), Chronic Kidney Disease Epidemiology (CKD-EPI) Collaboration, Wright and full age spectrum (FAS)). Bias, precision and accuracy of eGFR formulae were examined. We also evaluated statistics of agreement: the total deviation index (TDI), the concordance correlation coefficient (CCC) and the coverage probability (CP). Multivariate logistic regression was applied to identify characteristics associated with inaccurate eGFR and construct a predictive nomogram.
All eGFR formulae tended to overestimate the eGFR. The percentage of patients with eGFR within 30% the mGFR ranged from 38.0 to 62.8%. Cockcroft-Gault and MDRD showed low bias and high precision. The MDRD formula exhibited lowest TDI, meaning that 90% of estimations ranged from - 36 to 36% of mGFR. Multivariate logistic regression showed that inaccuracy of MDRD was found in elderly patients or in patients with eGFR greater than 120 ml/min. A nomogram was constructed to help oncologists to predict the risk of inaccuracy of eGFR. The calibration curve showed good agreement.
Our results suggest that the error of eGFR by any formulae was common and wide in Chinese oncology patients. Our nomogram may assist oncologists in decision-making when mGFR is needed.
A three-channel conductance probe has been proposed to measure the water holdup in oil-in-water flows with low-flow rate and high-water cut. The probe consists of three pairs of arc shape electrodes ...with center body. The geometry of the electrodes in each channel has been optimized using the finite-element method. An oil-in-water flow test has been conducted in the pipe with 20-mm inner diameter, the values of total flow rate are in the range 0.5-7 m 3 /day and the values of water cut are in the range 50%-99%. Normalized conductivity of fluid mixture has been calculated to a chart of water holdup according to the probe responses. The experimental results show that the three-channel conductance probe has high resolution of water holdup measurement in oil-in-water flows. In particular, the flow rate influence to the water holdup measurement was significantly reduced.
Background and Objectives: If the proportion of calcium intake over a whole day is related to the risk of cognitive impairment in adults is still largely unknown. This research aimed to examine the ...relation of dietary calcium intake at dinner versus breakfast with the risk of cognitive impairment by using data from the China Health and Nutrition Survey (CHNS). Methods and Study Design: A total of 2,099 participants (including 668 cognitive impairment) in the CHNS (1997-2006) were included. The participants were categorized into 5 groups in accordance with the ratio of dietary calcium intake at dinner and breakfast (Delta equivalent dinner/breakfast). After adjustment was conducted for a series of confounding factors, Cox hazard regression modelling was performed to discuss the relation of Delta with cognitive impairment. Dietary substitution models were used to explore the changes in cognitive impairment risk when a 5% dietary calcium intake at dinner was replaced with dietary calcium intake at breakfast. Results: Participants in the highest distribution of Delta showed a greater susceptibility to cognitive impairment than those in the lowest quintile, with an adjusted hazard ratio of cognitive impairment of 1.38 (95% CI: 1.08-1.76). When maintaining total calcium intake, substituting 5% of dietary calcium intake at dinner with calcium intake at breakfast was related to an 8% decrease in the risk of cognitive impairment. Conclusions: Higher dietary calcium intake at dinner was associated with an increased risk of cognitive impairment, emphasizing the importance of appropriately distributing dietary calcium intake between breakfast and dinner.
This paper aims to experimentally investigate pressure drop and water holdup in vertical upward oil-in-water emulsions. As a key factor to extract water holdup with differential pressure method, ...friction factor is complicatedly associated with the Reynolds number of mixed fluid. However, due to the fact that oil and water phase cannot be easily separated in emulsions, the traditional quick-closing valve (QCV) method is incapable of determining water holdup, which is imperative to determine the Reynolds number of mixed fluid. In this paper, regarded as an auxiliary measurement method, an arc type conductivity probe (ATCP) is utilized to derive water holdup parameter. Combining water holdup and differential pressure information, we extract friction factor and analyze its relationship with the Reynolds number of mixed fluid. Besides, drag reduction phenomena in surfactant aqueous solution and oil-in-water emulsions are discussed as well. Finally, water holdup is predicted using differential pressure information and experimental expression of friction factor, the result of which proves the effectiveness of differential pressure method for the measurement of water holdup in oil-in-water emulsions.
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