The limit of dynamic endurance during repetitive contractions has been referred to as the point of muscle fatigue, which can be measured by mechanical and electrophysiological parameters combined ...with subjective estimates of load tolerance for revealing the human real-world capacity required to work continuously. In this study, an isotonic muscular endurance (IME) testing protocol under a psychophysiological fatigue criterion was developed for measuring the retentive capacity of the power output of lower limb muscles. Additionally, to guide the development of electrophysiological evaluation methods, linear and non-linear techniques for creating surface electromyography (sEMG) models were compared in terms of their ability to estimate muscle fatigue. Forty healthy college-aged males performed three trials of an isometric peak torque test and one trial of an IME test for the plantar flexors and knee and hip extensors. Meanwhile, sEMG activity was recorded from the medial gastrocnemius, lateral gastrocnemius, vastus medialis, rectus femoris, vastus lateralis, gluteus maximus, and biceps femoris of the right leg muscles. Linear techniques (amplitude-based parameters, spectral parameters, and instantaneous frequency parameters) and non-linear techniques (a multi-layer perception neural network) were used to predict the time-dependent power output during dynamic contractions. Two mechanical manifestations of muscle fatigue were observed in the IME tests, including power output reduction between the beginning and end of the test and time-dependent progressive power loss. Compared with linear mapping (linear regression) alone or a combination of sEMG variables, non-linear mapping of power loss during dynamic contractions showed significantly higher signal-to-noise ratios and correlation coefficients between the actual and estimated power output. Muscular endurance required in real-world activities can be measured by considering the amount of work produced or the activity duration via the recommended IME testing protocol under a psychophysiological termination criterion. Non-linear mapping techniques provide more powerful mapping of power loss compared with linear mapping in the IME testing protocol.
Evidence shows that intestinal inflammation, oxidative stress, and injury of mucosal barrier are closely related to the pathogenesis of ulcerative colitis (UC). Huang-lian-Jie-du Decoction (HLJDD) is ...a well-known prescription of traditional Chinese medicine with anti-inflammatory and antioxidative activities, which may be used to treat UC. However, its therapeutic effect and mechanism are still unclear. In this study, the UC model of BABL/c mice were established by DSS 3.5% (w/v), and HLJDD was given orally for treatment at the same time. During the experiment, the clinical symptoms of mice were scored by disease activity index (DAI). Besides, the effects of HLJDD on immune function, oxidative stress, colon NF-κB and Nrf2 signaling pathway, and intestinal mucosal barrier function in UC mice were also investigated. The results showed that HLJDD could alleviate body weight loss and DAI score of UC mice, inhibit colonic shortening and relieve colonic pathological damage, and reduce plasma and colon MPO levels. In addition, HLJDD treatment significantly up-regulated plasma IL-10, down-regulated TNF-α and IL-1β levels, and inhibited the expression of NF-κB p65, p-IκKα/β, and p-IκBα proteins in the colon. Moreover, NO and MDA levels in colon tissues were significantly reduced after HLJDD treatment, while GSH, SOD levels and Nrf2, Keap1 protein expression levels were remarkably elevated. Additionally, HLJDD also protected intestinal mucosa by increasing the secretion of mucin and the expression of ZO-1 and occludin in colonic mucosa. These results indicate that HLJDD could effectively alleviate DSS-induced mice UC by suppressing NF-κB signaling pathway, activating Nrf2 signaling pathway, and enhancing intestinal barrier function.
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•An experimental strategy is proposed to evaluate the energy performance of MOF-based CO2 adsorbents.•The energy property of UiO-66-X MOFs with various functional groups has been ...reasonably evaluated using this strategy.•An inverse proportional relationship between parasitic energy and working capacity is found for UiO-66-X MOFs.•It is found that the key determinants for the regeneration energy efficiency are the specific heat capacity of adsorbents and CO2 working capacity.
Recently, metal–organic frameworks (MOFs) have attracted great interest in the field of carbon capture and storage (CCS) as promising carbon dioxide (CO2) adsorbents. The energy performance in relation to the regeneration process is a crucial factor when screening for suitable CCS MOF adsorbents. However, few experimental methods have been reported for evaluating the energy requirements for their regeneration. Herein, we proposed an experimental strategy to investigate the energy performance of MOF adsorbents for CO2 capture in the temperature swing adsorption (TSA) process using a combination of calorimetry and thermal analysis method. Five well-characterized isomorphic zirconium-based MOFs (University of Oslo 66-X, where X = H, NH2, (OH)2, C4H4, or NO2) were reliably evaluated using this strategy. The energy parameters related to regeneration, including specific heat capacities, thermodynamic functions, desorption temperatures, regeneration energy, CO2 working capacities, and parasitic energy, were accurately determined for these MOFs. The results indicated that the key determinants for the regeneration energy efficiency of CO2 adsorbents were their specific heat capacities and CO2 working capacities during a TSA cycle. More importantly, the proposed strategy may provide a feasible and effective experimental approach to study and evaluate the potential of adsorbents for CO2 capture.
•Marine diatom P. tricornutum grew well in mixed wastewater and seawater.•P. tricornutum demonstrated high nutrient removal ability under MW: SW = 1:1 and 2:1.•Biomass and lipid productivity were ...improved under MW: SW = 1:1 and 2:1 with aeration.•Highest lipid productivity was achieved with two-step cultivation under MW: SW = 1:1.
This study was conducted to evaluate the potential of the marine diatom Phaeodactylum tricornutum in nutrient removal coupled with biodiesel production using different ratios of mixed municipal wastewater (MW) and seawater (SW) as the growth medium. The results indicated that P. tricornutum exhibited high nutrient removal efficiency with the ratios of MW: SW = 1:1 and MW: SW = 2:1, e.g. 87.7–89.9% for chemical oxygen demand (COD), 82.2–86.7% for total nitrogen (TN), 96.0–97.0% for total phosphorus, and 76.9–84.2% for ammonium (NH3-N). Significantly higher biomass and lipid productivity were obtained with aeration. The highest lipid productivity of P. tricornutum was 54.76 mg/L/day, which was obtained with a two-step cultivation using the ratio of MW: SW = 1:1 by diluting half of the mixture and bubbling with 5% CO2 during the second step. These results suggested that the marine diatom P. tricornutum exhibited great potential for using mixed wastewater for wastewater treatment and biodiesel production.
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•Five different polar parts of HLJDD were prepared by system solvent method combined with Soxhlet extractor.•In vitro and in vivo experiments show that HLJDD-NBA fraction is an ...effective fraction of HLJDD in the treatment of UC.•HLJDD and HLJDD-NBA fraction can alleviate intestinal flora disorder in UC mice.
Huang-lian-Jie-du Decoction (HLJDD) is a classical prescription for clearing away heat and detoxification. In order to screen the effective fraction of HLJDD in the treatment of ulcerative colitis (UC) in mice and explore its effects on intestinal flora in UC mice, we prepared different polar fractions of HLJDD by system solvent extraction method. Subsequently, the contents of 13 active compounds in different polar fractions of HLJDD were determined by HPLC. Further, the UC model induced by dextran sodium sulfate was used to evaluate the therapeutic effects of different polar fractions of HLJDD. Finally, cecal contents were used for sequencing and analysis of bacterial 16S rRNA genes. The results showed that the yield of HLJDD-n-butanol (HLJDD-NBA) fraction was the highest, and the content or proportion of 13 active compounds in HLJDD-NBA fraction were the most similar to HLJDD. In addition, in vivo pharmacodynamic experiments showed that HLJDD-NBA intervention not only significantly alleviated the clinical symptoms of UC mice and ameliorated the pathological damage of colon tissue, but also showed significant anti-inflammatory and antioxidative effects (p < 0.05), which were comparable to HLJDD (p > 0.05). Moreover, both HLDD and HLJDD-NBA treatments can restore the intestinal flora homeostasis of UC mice by inhibiting the growth of intestinal pathogens and preventing the decrease of beneficial bacteria. Meanwhile, they can also significantly correct the dysfunction of intestinal flora in UC mice. In conclusion, we proved that HLJDD-NBA fraction is an effective fraction of HLJDD in treating UC in mice, and it can maintain the intestinal flora homeostasis of UC mice, which increases our understanding of the mechanism of HLJDD in treating UC and lays a foundation for the development of new anti-ulcer drugs.
To expand the application of light‐weight and high‐strength polymer matrix composites in the fields of aerospace, shipbuilding and transportation, it has designed and fabricated a new‐type carbon ...fiber fabric/hollow glass beads/epoxy resin (CFF/HGB/EP) composite with a three‐layer sandwich structure, consisting of an upper composite layer (CFF/EP), core layer (HGB/EP) and lower composite layer (CFF/EP). The effects of the CFF/EP layer and the HGB content on the sandwich composites were explored through a systematic investigation of the mechanical properties and microstructure. The results indicate that the density of the sandwich composite can be reduced to 0.83 g cm−3, while the flexural, impact, and tensile strength of the sandwich composite can be increased by 227%, 156%, and 118% compared with pure epoxy resin, respectively. The great improvement of mechanical properties of the sandwich composite makes its application in various industries more promising.
Designed and fabricated a new type of light‐weight and high‐strength carbon fiber/hollow glass beads/epoxy resin sandwich composite laminates.
Global warming has multifarious effects on crop growth and productivity. Nonetheless, the effects of moderate-high temperatures and melatonin on tea yield and quality remain unclear. In this study, ...we found that melatonin, a universal growth stimulatory molecule, not only promotes photosynthesis and biomass accumulation in tea plants (Camellia sinensis L.) but also improves tea quality under sub high temperature (SHT). SHT increased the dry biomass and photosynthesis by 40.8% and 28.1%, respectively, and exogenous melatonin caused a further improvement. Moreover, SHT increased the total polyphenol concentrations and decreased the free amino acid concentrations, leading to a significant increase (68.2%) in polyphenol to free amino acid ratio. However, melatonin decreased the polyphenol to free amino acid ratio by delicately improving the concentrations of polyphenols and amino acids. Consistent with the total polyphenol, melatonin increased the concentrations of (-)-catechin, (-)-gallocatechin (GC), and (-)-epigallocatechin-3-gallate (EGCG) in tea leaves. The qRT-PCR analysis revealed that melatonin increased the transcript levels of catechins biosynthesis genes, such as CsCHS, CsCH1, CsF3H, CsDFR, CsANS, CsLAR, and CsANR under SHT. Meanwhile, the theanine concentration was decreased by SHT, which was attributed to the attenuated expression of CsGS, CsGOGAT, CsGDH, and CsTS1. Nonetheless, melatonin significantly increased those transcripts and the content of theanine under SHT. Melatonin also increased the caffeine content by inducing the expression of CsTIDH, CssAMS, and CsTCS1. These results suggest that melatonin could positively alter tea growth and quality by modulating the photosynthesis and biosynthesis of polyphenols, amino acids, and caffeine in tea leaves under SHT.
Imidazolium-based ionic liquids have been widely applied in the synthesis of organic hybrid chalcogenidometalates, while the other types of ionic liquids are rarely tried. Reported here is the first ...application of a pyridinium-based ionic liquid in the preparation of two main-group heterometallic selenides featuring isomorphic three-dimensional frameworks. Of particular interest is that three gallium–tin selenides possessing another type of three-dimensional framework have been prepared by replacing the pyridinium-based ionic liquid with imidalolium-based ionic liquids under the same reaction conditions.
Plant steroid hormones, brassinosteroids (BRs), play essential roles in plant growth, development and stress responses. However, mechanisms by which BRs interfere with plant resistance to virus ...remain largely unclear. In this study, we used pharmacological and genetic approaches in combination with infection experiments to investigate the role of BRs in plant defense against Tobacco Mosaic Virus (TMV) in Nicotiana benthamiana. Exogenous applied BRs enhanced plant resistance to virus infection, while application of Bikinin (inhibitor of glycogen synthase kinase-3), which activated BR signaling, increased virus susceptibility. Silencing of NbBRI1 and NbBSK1 blocked BR-induced TMV resistance, and silencing of NbBES1/BZR1 blocked Bikinin-reduced TMV resistance. Silencing of NbMEK2, NbSIPK and NbRBOHB all compromised BR-induced virus resistance and defense-associated genes expression. Furthermore, we found MEK2-SIPK cascade activated while BES1/BZR1 inhibited RBOHB-dependent ROS production, defense gene expression and virus resistance induced by BRs. Thus, our results revealed BR signaling had two opposite effects on viral defense response. On the one hand, BRs enhanced virus resistance through MEK2-SIPK cascade and RBOHB-dependent ROS burst. On the other hand, BES1/BZR1 inhibited RBOHB-dependent ROS production and acted as an important mediator of the trade-off between growth and immunity in BR signaling.
Medical artificial intelligence (AI) has entered the clinical implementation phase, although real-world performance of deep-learning systems (DLSs) for screening fundus disease remains ...unsatisfactory. Our study aimed to train a clinically applicable DLS for fundus diseases using data derived from the real world, and externally test the model using fundus photographs collected prospectively from the settings in which the model would most likely be adopted.
In this national real-world evidence study, we trained a DLS, the Comprehensive AI Retinal Expert (CARE) system, to identify the 14 most common retinal abnormalities using 207 228 colour fundus photographs derived from 16 clinical settings with different disease distributions. CARE was internally validated using 21 867 photographs and externally tested using 18 136 photographs prospectively collected from 35 real-world settings across China where CARE might be adopted, including eight tertiary hospitals, six community hospitals, and 21 physical examination centres. The performance of CARE was further compared with that of 16 ophthalmologists and tested using datasets with non-Chinese ethnicities and previously unused camera types. This study was registered with ClinicalTrials.gov, NCT04213430, and is currently closed.
The area under the receiver operating characteristic curve (AUC) in the internal validation set was 0·955 (SD 0·046). AUC values in the external test set were 0·965 (0·035) in tertiary hospitals, 0·983 (0·031) in community hospitals, and 0·953 (0·042) in physical examination centres. The performance of CARE was similar to that of ophthalmologists. Large variations in sensitivity were observed among the ophthalmologists in different regions and with varying experience. The system retained strong identification performance when tested using the non-Chinese dataset (AUC 0·960, 95% CI 0·957–0·964 in referable diabetic retinopathy).
Our DLS (CARE) showed satisfactory performance for screening multiple retinal abnormalities in real-world settings using prospectively collected fundus photographs, and so could allow the system to be implemented and adopted for clinical care.
This study was funded by the National Key R&D Programme of China, the Science and Technology Planning Projects of Guangdong Province, the National Natural Science Foundation of China, the Natural Science Foundation of Guangdong Province, and the Fundamental Research Funds for the Central Universities.
For the Chinese translation of the abstract see Supplementary Materials section.
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