AabHLH113 integrates jasmonic acid and abscisic acid signaling to positively regulate artemisinin biosynthesis in Artemisia annua.

Artemisinin, a sesquiterpene lactone isolated from Artemisia annua, is in huge market demand due to its efficient antimalarial action, especially after the COVID-19 pandemic. Many researchers have elucidated that phytohormones jasmonic acid (JA) and abscisic acid (ABA) positively regulate artemisinin biosynthesis via types of transcription factors (TFs). However, the crosstalk between JA and ABA in regulating artemisinin biosynthesis remains unclear. Here, we identified a novel ABA- and JA-induced bHLH TF, AabHLH113, which positively regulated artemisinin biosynthesis by directly binding to the promoters of artemisinin biosynthetic genes, DBR2 and ALDH1. The contents of artemisinin and dihydroartemisinic acid increased by 1.71- to 2.06-fold and 1.47- to 2.23-fold, respectively, in AabHLH1113 overexpressed A. annua, whereas they decreased by 14-36% and 26-53%, respectively, in RNAi-AabHLH113 plants. Furthermore, we demonstrated that AabZIP1 and AabHLH112, which, respectively, participate in ABA and JA signaling pathway to regulate artemisinin biosynthesis, directly bind to and activate the promoter of AabHLH113. Collectively, we revealed a complex network in which AabHLH113 plays a key interrelational role to integrate ABA- and JA-mediated regulation of artemisinin biosynthesis.

Ripple phenomenon and artifact elimination in millimeter-wave imaging of a hidden target.

In millimeter-wave imaging of a hidden target, the effect of the dielectric cover before the target is typically ignored. This results in ripple-corrupted images that pose challenges for target recognition. In this paper, we provide a perspective for understanding the image of the hidden target, which clearly reveals the origin of the ripples, and propose a separation method that not only gets rid of ripples, but also obtains the target's depth map. Reflections and transmissions during imaging are considered and decoupled to separately form images corresponding to each real or virtual object. An algorithm based on the range-direction spread function is developed to iteratively estimate the depth and reflectivity of the target. Imaging experiments with and without a cover are conducted to demonstrate the formation and influence of ripples and to verify the proposed algorithm. Our work deepens the comprehension of covered target imaging. Benefited fields might include non-destructive testing, through-wall imaging, subsurface imaging, and security screening.

A collaborative effect of solid-phase denitrification and algae on secondary effluent purification.

This study explored the collaborative effect on nutrients removal performance and microbial community in solid-phase denitrification based bacteria-algae symbiosis system. Three biodegradable carriers (apple wood, poplar wood and corncob) and two algae species (Chlorella vulgaris and Chlorella pyrenoidosa) were selected in these bacteria-algae symbiosis systems. Results demonstrated that corncob as the carrier exhibited the highest average removal efficiencies of total nitrogen (83.7%-85.1%) and phosphorus removal (38.1%-49.1%) in comparison with apple wood (65.8%-71.5%, 25.5%-32.7%) and poplar wood (42.5%-49.1%, 14.2%-20.7%), which was mainly attributed to the highest organics availability of corncob. The addition of Chlorella acquired approximately 3%-5% of promotion rates for nitrated removal among three biodegradable carriers, but only corncob reactor acquired significant promotions by 3%-11% for phosphorous removal. Metagenomics sequencing analysis further indicated that Proteobacteria was the largest phylum in all wood reactors (77.1%-93.3%) and corncob reactor without Chlorella (85.8%), while Chlorobi became the most dominant phylum instead of Proteobacteria (20.5%-41.3%) in the corncob with addition of Chlorella vulgaris (54.5%) and Chlorella pyrenoidosa (76.3%). Thus, the higher organics availability stimulated the growth of algae, and promoted the performance of bacteria-algae symbiosis system based biodegradable carriers.

[Inhibition of glutaminolysis alleviates myocardial fibrosis induced by angiotensin II].

The present study was aimed to investigate the role and mechanism of glutaminolysis of cardiac fibroblasts (CFs) in hypertension-induced myocardial fibrosis. C57BL/6J mice were administered with a chronic infusion of angiotensin II (Ang II, 1.6 mg/kg per d) with a micro-osmotic pump to induce myocardial fibrosis. Masson staining was used to evaluate myocardial fibrosis. The mice were intraperitoneally injected with BPTES (12.5 mg/kg), a glutaminase 1 (GLS1)-specific inhibitor, to inhibit glutaminolysis simultaneously. Immunohistochemistry and Western blot were used to detect protein expression levels of GLS1, Collagen I and Collagen III in cardiac tissue. Neonatal Sprague-Dawley (SD) rat CFs were treated with 4 mmol/L glutamine (Gln) or BPTES (5 µmol/L) with or without Ang II (0.4 µmol/L) stimulation. The CFs were also treated with 2 mmol/L α-ketoglutarate (α-KG) under the stimulation of Ang II and BPTES. Wound healing test and CCK-8 were used to detect CFs migration and proliferation respectively. RT-qPCR and Western blot were used to detect mRNA and protein expression levels of GLS1, Collagen I and Collagen III. The results showed that blood pressure, heart weight and myocardial fibrosis were increased in Ang II-treated mice, and GLS1 expression in cardiac tissue was also significantly up-regulated. Gln significantly promoted the proliferation, migration, mRNA and protein expression of GLS1, Collagen I and Collagen III in the CFs with or without Ang II stimulation, whereas BPTES significantly decreased the above indices in the CFs. α-KG supplementation reversed the inhibitory effect of BPTES on the CFs under Ang II stimulation. Furthermore, in vivo intraperitoneal injection of BPTES alleviated cardiac fibrosis of Ang II-treated mice. In conclusion, glutaminolysis plays an important role in the process of cardiac fibrosis induced by Ang II. Targeted inhibition of glutaminolysis may be a new strategy for the treatment of myocardial fibrosis.

Time-restricted feeding alleviates cardiac dysfunction induced by simulated microgravity via restoring cardiac FGF21 signaling.

Dietary restriction has been well-described to improve health metrics, but whether it could benefit pathophysiological adaptation to extreme environment, for example, microgravity, remains unknown. Here, we investigated the effects of a daily rhythm of fasting and feeding without reducing caloric intake on cardiac function and metabolism against simulated microgravity. Male rats under ad libitum feeding or time-restricted feeding (TRF; food access limited to 8 hours every day) were subjected to hindlimb unloading (HU) to simulate microgravity. HU for 6 weeks led to left ventricular dyssynchrony and declined cardiac function. HU also lowered pyruvate dehydrogenase (PDH) activity and impaired glucose utilization in the heart. All these were largely preserved by TRF. TRF showed no effects on HU-induced loss of cardiac mass, but significantly improved contractile function of cardiomyocytes. Interestingly, TRF raised liver-derived fibroblast growth factor 21 (FGF21) level and enhanced cardiac FGF21 signaling as manifested by upregulation of FGF receptor-1 (FGFR1) expression and its downstream markers in HU rats. In isolated cardiomyocytes, FGF21 treatment improved PDH activity and glucose utilization, consequently enhancing cell contractile function. Finally, both liver-specific knockdown (KD) of FGF21 and cardiac-specific FGFR1 KD abrogated the cardioprotective effects of TRF in HU rats. These data demonstrate that TRF improves cardiac glucose utilization and ameliorates cardiac dysfunction induced by simulated microgravity, at least partially, through restoring cardiac FGF21 signaling, suggesting TRF as a potential countermeasure for cardioprotection in long-term spaceflight.

Dynamics of denitrification performance and denitrifying community under high-dose acute oxytetracycline exposure and various biorecovery strategies in polycaprolactone-supported solid-phase denitrification.

Solid-phase denitrification (SPD) is a promising technology for nitrate-rich water purification. This study aimed to examine the variation in denitrification performance and denitrifying community under high-dose acute oxytetracycline (OTC) exposure and various biorecovery strategies. The denitrification performance was impaired significantly after one-day OTC shock at 50 mg L-1 in a continuous-flow SPD system supported by a polycaprolactone (PCL) carrier but could rapidly recover without the addition of OTC. When 50 mg L-1 OTC stress was applied for a longer time in the batch tests, a natural recovery period of more than 20 days was required to reach more than 95% nitrate reduction. Under the same conditions, the addition of both mature biofilm-attached PCL carrier and fresh biofilm-free PCL carrier significantly shortened the recovery time for efficient nitrate reduction, mainly due to the increase in organic availability from the PCL carriers. However, the composition of the microbial community notably changed due to the effects of OTC according to high-throughput sequencing and metagenomic analysis. Genes encoding NAR and NIR were much more sensitive than those encoding NOR and NOS to OTC shock. Tetracycline resistance gene (TRG) enrichment was 15.86% higher in the biofilm that experienced short-term OTC shock than in the control biofilm in the continuous-flow SPD system.

Performance and microbial diversity of denitrifying biofilms on polyurethane foam coupled with various solid carbon sources for nitrate-rich water purification.

This study investigated the performance and microbial communities of denitrifying biofilms on polyurethane foam coupled with various solid carbon sources of acid- and alkali-pretreated rice straw and rice husk. Results showed that acid and alkali-pretreated rice straw both had higher TOC release rates (0.041-0.685 mg g-1 day-1) than those of rice husk (0.019-0.160 mg g-1 day-1) over a month, while acid pretreatment of rice husk and rice straw had a much higher organics release rate than that of alkali pretreatment and non-pretreatment, respectively. Acid-pretreated rice straw achieved the most efficient TN removal performance (82.06 ± 3.65%) with the lower occurrences of NH4+-N during denitrification than that of alkali-pretreated rice straw (80.05 ± 4.12%) over more than a month operation. However, alkali pretreatment of rice husk demonstrated much more significantly efficient TN removal efficiency (80.39 ± 2.1%) than did acid pretreatment (69.59 ± 13.43%). MiSeq sequencing analysis showed that the four biofilm samples attached on polyurethane foam with the addition of pretreated rice straw or rice husk had a range of 13-15 differentially abundant phylum and 81-123 differentially abundant genera in comparison with biofilm without extra solid carbon sources, and a higher TN removal efficiency demonstrated more types of differentially abundant genera.

Comparative analysis of denitrification performance, denitrifying community and functional genes to oxytetracycline exposure between single and hybrid biodegradable polymers supported solid-phase denitrification systems.

Biodegradable carrier are vital for the solid-phase denitrification (SPD) systems for treating nitrate-rich water. Two solid-phase denitrification reactors were developed with both 200 g L-1 of single (polycaprolactone, PCL) (R1) and hybrid solid carbon sources (PCL/polylactic acid (PLA) /polyhydroxyalkanoates (PHA)) (R2) to examine the denitrification performance, denitrifying community and functional genes to various oxytetracycline (OTC) exposure in this study, respectively. Complete denitrification performance was achieved in the both SPD systems at low stress of OTC (1 mg L-1), but then dramatically reduced to less than 20% of nitrate reduction efficiency after one-month high OTC stress (10 mg L-1), and rapidly recovered to stable nitrate removal rates of 76.77 ± 5.48% (R1) and 40.68 ± 4.40% (R2) after the next day of no OTC stress. However, the reactor R1 with single PCL carriers acquired more efficient nitrate removal rate than that of reactor R2 at the high OTC stress and recovery phase with OTC stress, mainly due to the more organics availability from the single PCL carriers. The richness and diversity of nirK and nirS deintrifiers significantly declined at high OTC stress, and much more of those occurred in biofilm R1 with more organics availability. Besides, biofilm R1 achieved much more abundant periplasmic nitrate reductase, nitrite reductase genes and tetracycline resistance genes after high OTC stress, which explained the potential resistance to OTC and rapid recovery efficiency after no stress of OTC. Thus, the organics availability played an important role in assuring SPD system to be efficient under high OTC stress.

Assessment of nutrient removal and microbial population dynamics in a non-aerated vertical baffled flow constructed wetland for contaminated water treatment with composite biochar addition.

A novel composite biochar (NCB) was produced from the pyrolysis of co-fermentation products of sewage sludge, food wastes and rice straw, and exhibited higher nitrogen and phosphorus adsorption capacity due to the larger surface area (14.7 m2 g-1) and higher Ca content (51753.7 mg kg-1) than single rice straw biochar. The addition of NCB was then investigated in a non-aerated vertical baffled flow constructed wetland (VBFCW) for contaminated water treatment. The VBFCW with NCB addition significantly improved CODMn, NH4+-N, TN and TP removal efficiencies of 83.3 ±â€¯5.3%, 95.9 ±â€¯3.4%, 28.0 ±â€¯4.0% and 59.5 ±â€¯11.8%, respectively, at a hydraulic retention time (HRT) of 3 d. In addition, the TN and TP removal rates at a decreased HRT of 2 d were much higher than those at an HRT of 3 d without NCB addition. The presence of NCB in the VBFCW system enhanced nutrient adsorption and improved the enrichment of bacteria for organic and nitrogen removal mainly including the genera Bacillus and Lactococcus.

Optimization of hydraulic shear parameters and reactor configuration in the aerobic granular sludge process.

The hydraulic shear acts as an important selection pressure in aerobic sludge granulation. The effects of the hydraulic shear rate and reactor configuration on structural characteristics of aerobic granule in view of the hydromechanics. The hydraulic shear analysis was proposed to overcome the limitation of using superficial gas velocity (SGV) to express the hydraulic shear stress. Results showed that the stronger hydraulic shear stress with SGV above 2.4 cm s(-1) promoted the microbial aggregation, and favoured the structural stability of the granular sludge. According to the hydraulic shear analysis, the total shear rate reached (0.56-2.31)×10(5) s(-1) in the granular reactor with a larger ratio of height to diameter (H/D), and was higher than that in the reactor with smaller H/D, where the sequencing airlift bioreactor with smaller H/D had a high total shear rate under the same SGV. Results demonstrated that the granular reactor could provide a stronger hydraulic shear stress which promotes the formation and structural stability of aerobic granules.

Understanding the N-acylated homoserine lactones(AHLs)-based quorum sensing for the stability of aerobic granular sludge in the aspect of substrate hydrolysis enhancement.

Efficient substrate metabolism is the premise for stable operation of aerobic granular sludge and can be regulated by quorum sensing (QS). In this study, starch and acetate were selected to represent complex and simple substrates to provide comparable amount of metabolic energy for granules cultivation. Starch-fed granules were larger in size and contained higher EPS content than acetate-fed granules, though both granules exhibited similar substrate-degradation rates during sequencing batch reactor (SBR) cycle. Three N-acylhomoserine lactones (AHLs), including C8-HSL, 3OHC8-HSL and 3OHC12-HSL, were detected as dominant autoinducers in granules. They accumulated more in starch-fed granules than acetate-fed granules. The batch experiments were implemented to investigate QS regulation for granular stability in terms of substrate hydrolysis and transformation. The addition of three AHLs increased the activity of α-amylase, the main starch hydrolase, 4-6 times, significantly (p < 0.01) higher than the control treatment without AHLs amendment. While activity of dehydrogenase, the main simple substrate degradation enzyme, was increased only 1-2 times. Higher enzyme activity, especially α-amylase, significantly (p < 0.05) promoted the substrate-degradation rate (65 % than control group) and EPS yield in starch-fed system. Overall, QS can facilitate complex substrate uptake via hydrolysis enhancement and EPS secretion, which together promote sludge granulation and stability.

Quantitative Evaluation of Thermal Ageing State of Cross-Linked Polyethylene Insulation Based on Polarization and Depolarization Current.

The widespread use of cross-linked polyethylene (XLPE) as insulation in cables may be attributed to its outstanding mechanical and dielectric properties. In order to quantitatively evaluate the insulation status of XLPE after thermal ageing, an accelerated thermal ageing experimental platform is established. Polarization and depolarization current (PDC) as well as elongation at break of XLPE insulation under different ageing durations are measured. XLPE insulation state is determined by the elongation at break retention rate (ER%). Based on the extended Debye model, the paper proposed the stable relaxation charge quantity and the dissipation factor at 0.1 Hz to evaluate the insulation state of XLPE. The results show that the ER% of XLPE insulation decreases with the growth of ageing degree. The polarization and depolarization current of XLPE insulation will increase obviously with thermal ageing. Conductivity and trap level density will also increase. The number of branches of the extended Debye model increases, and new polarization types appear. Stable relaxation charge quantity and dissipation factor at 0.1 Hz proposed in this paper have a good fitting relationship with ER% of XLPE insulation, which can evaluate the thermal ageing state of XLPE insulation effectively.

Bicarbonate enhanced heterogeneous activation of peroxymonosulfate by copper ferrite nanoparticles for the efficient degradation of refractory organic contaminants in water.

Nowadays, the treatment of residual refractory organic contaminants (ROCs) is a huge challenge for environmental remediation. In this study, a potential process is provided by copper ferrite catalyst (CuFe2O4) activated peroxymonosulfate (PMS, HSO5-) in the bicarbonate (HCO3-) enhanced system for efficient removal of Acid Orange 7 (AO7), 2,4-dichlorophenol, phenol and methyl orange (MO) in water. The impact of key reaction parameters, water quality components, main reactive oxygen species (ROS), probable degradation mechanism, rational degradation pathways and catalyst stability were systematically investigated. A 95.0% AO7 (C0 = 100 mg L-1) removal was achieved at initial pH (pH0) of 5.9 ± 0.1 (natural pH), CuFe2O4 dosage of 0.15 g L-1, PMS concentration of 0.98 mM, HCO3- concentration of 2 mM, and reaction time of 30 min. Both sulfate radical (SO4-•) and hydroxyl radical (•OH) on the surface of catalyst were proved as the predominant radical species through radical quenching experiments and electron paramagnetic resonance (EPR) analysis. The buffer nature of HCO3- was partially contributed for the enhanced degradation of AO7 under CuFe2O4/PMS/HCO3- system. Importantly, according to 13C nuclear magnetic resonance (NMR) and EPR analysis, the positive effect of bicarbonate may be mainly attributed to the formation of peroxymonocarbonate (HCO4-), which may enhance the generation of •OH. The magnetic CuFe2O4 particles can be well recycled and the leaching concentration of Cu was acceptable (<1 mg L-1). Considering the widespread presence of bicarbonate in water environment, this work may provide a safe, efficient, and sustainable technique for the elimination of ROCs from practical complex wastewater.

Echocardiographic evaluation of cardiac reserve to detect subtle cardiac dysfunction in mice.

AIMS: Cardiac reserve is a sensitive tool for early detection of cardiac dysfunction. However, cardiac reserve assessment by catecholamine stress echocardiography in mice varied in the doses of ß-adrenergic agonists and the time point for measurements, which may lead to inaccurate readouts. This study aims to establish a standardized protocol for assessing cardiac reserve in mice. MAIN METHODS: C57BL/6J mice under isoflurane anesthesia were intraperitoneally injected with varying doses of isoproterenol (Iso), and subjected to echocardiographic measurements. KEY FINDINGS: Heart rate (HR), ejection fraction (EF), fractional shortening (FS), global longitudinal strain (GLS) and strain rate all reached peak values within 1-3 min after Iso injection at doses higher than 0.2 mg/kg. Compared with 0.1 mg/kg Iso, 0.2 mg/kg Iso resulted in higher HR, EF, FS and GLS, whereas doses higher than 0.2 mg/kg did not yield further increase. Cardiac response of female mice recapitulated main characteristics of those of male mice except that female mice displayed higher maximum HR and were more sensitive to higher doses of Iso. Furthermore, the advantages of present stress protocol over conventional baseline echocardiographic measurements were verified in comparisons of exercised vs. sedentary and aged vs. young mice for cardiac function evaluation. SIGNIFICANCE: We developed a reproducible and sensitive approach to evaluate cardiac reserve by continuously monitoring cardiac function every minute for 3 min after 0.2 mg/kg Iso injection. This approach will enable detection of subtle cardiac dysfunction and accelerate innovative research in cardiac pathophysiology.

Enhancing the Output Performance of a Triboelectric Nanogenerator Based on Modified Polyimide and Sandwich-Structured Nanocomposite Film.

Recently, scientists have been facing major obstacles in terms of improving the performances of dielectric materials for triboelectric nanogenerators. The triboelectric nanogenerator (TENG) is one of the first green energy technologies that can convert random mechanical kinetic energy into electricity. The surface charge density of TENGs is a critical factor speeding up their commercialization, so it is important to explore unique methods to increase the surface charge density. The key to obtaining a high-performance TENG is the preparation of dielectric materials with good mechanical properties, thermal stability and output performance. To solve the problem of the low output performance of PI-based triboelectric nanogenerators, we modified PI films by introducing nanomaterials and designed a new type of sandwich-shaped nanocomposite film. Herein, we used polyimide (PI) with ideal mechanical properties, excellent heat resistance and flexibility as the dielectric material, prepared an A-B-A sandwich structure with PI in the outer layer and modified a copper calcium titanate/polyimide (CCTO/PI) storage layer in the middle to improve the output of a TENG electrode. The doping amount of the CCTO was tailored. The results showed that at 8 wt% CCTO content, the electrical output performance was the highest, and the open-circuit voltage of CCTO/PI was 42 V. In the TENG, the open-circuit voltage, short-circuit current and transfer charge of the prepared sandwich-structured film were increased by 607%, 629% and 672% compared to the TENG with the PI thin film, respectively. This study presents a novel strategy of optimizing dielectric materials for triboelectric nano-generators and has great potential for the future development of high output-performance TENGs.

Exercise protects aged mice against coronary endothelial senescence via FUNDC1-dependent mitophagy.

Vascular aging contributes to adverse changes in organ function and is a significant indicator of major cardiac events. Endothelial cells (ECs) participate in aging-provoked coronary vascular pathology. Regular exercise is associated with preservation of arterial function with aging in humans. However, the molecular basis is not well understood. The present study was aimed to determine the effects of exercise on coronary endothelial senescence and whether mitochondrial clearance regulator FUN14 domain containing 1 (FUNDC1)-related mitophagy and mitochondrial homeostasis were involved. In mouse coronary arteries, FUNDC1 levels showed gradually decrease with age. Both FUNDC1 and mitophagy levels in cardiac microvascular endothelial cells (CMECs) were significantly reduced in aged mice and were rescued by exercise training. Exercise also alleviated CMECs senescence as evidenced by senescence associated ß-galactosidase activity and aging markers, prevented endothelial abnormal cell migration, proliferation, and eNOS activation in CMECs from aged mice, and improved endothelium-dependent vasodilation of coronary artery, reduced myocardial neutrophil infiltration and inflammatory cytokines evoked by MI/R, restored angiogenesis and consequently alleviated MI/R injury in aging. Importantly, FUNDC1 deletion abolished the protective roles of exercise and FUNDC1 overexpression in ECs with adeno-associated virus (AAV) reversed endothelial senescence and prevented MI/R injury. Mechanistically, PPARγ played an important role in regulating FUNDC1 expressions in endothelium under exercise-induced laminar shear stress. In conclusion, exercise prevents endothelial senescence in coronary arteries via increasing FUNDC1 in a PPARγ-dependent manner, and subsequently protects aged mice against MI/R injury. These findings highlight FUNDC1-mediated mitophagy as potential therapeutic target that prevents endothelial senescence and myocardial vulnerability.

Repeated Inhalation of Peppermint Essential Oil Improves Exercise Performance in Endurance-Trained Rats.

Peppermint essential oil, being natural and safe, with antioxidant and anti-inflammatory properties, has long been a research interest in relieving fatigue and improving exercise performance. However, the related studies report controversial results, and the mechanisms remain unclear. Here we found that inhalation of peppermint essential oil significantly extended the exhaustion time in rats subjected to 2-week weight-bearing swimming training. Sprague-Dawley rats were subjected to a 2-week weight-loaded forced swimming regimen. Prior to each swimming session, the rats were administered peppermint essential oil via inhalation. An exhaustive swimming test was performed at the end of the protocol. Rats treated with essential oil had significantly extended time to exhaustion compared with exercised rats without essential oil treatment. In addition, treated rats also showed reduced oxidative damage induced by endurance exercise. Notably, the rats receiving two-week essential oil inhalation while not subjected to swimming training did not show improved exercise performance. The findings demonstrate that repeated inhalation of peppermint essential oil enhances the effects of endurance training and improves exercise performance partially by preventing oxidative damage.

Temperature-dependent metabolite orchestration to acute submaximal exercise indicates cardiorespiratory fitness in humans.

AIMS: Cardiorespiratory fitness (CRF), an important biomarker of human health, is impaired in cold environment compared to thermoneutral condition. The study aimed to investigate the role of metabolome response to acute exercise in regulation of CRF at different ambient temperatures. MAIN METHODS: A total of 27 young adults were recruited, and each subject underwent a cardiopulmonary exercise test (CPET) and a constant load submaximal exercise at both room temperature (25 °C) and cold temperature (0 °C). The serum samples were collected before and immediately after constant load exercise. KEY FINDINGS: Acute cold exposure decreased CRF by 41 %, accompanied by a metabolic shift to anaerobic respiration. It also decreased VO2 and increased respiratory quotient during constant load exercise. Metabolome profiling revealed that acute exercise reprogrammed serum metabolome in an ambient temperature-dependent manner. Specifically, exercise increased a cluster of fatty acids during cold exposure, possibly due to impaired fatty acid oxidation. The correlations between metabolite responses to acute exercise and exercise parameters were analyzed using partial least squares regression and machine learning, revealing that metabolite responses to acute exercise were highly correlated with exercise parameters and predictive of CRF. Among the contributors, tryptophan and its metabolites stood out as important ones. SIGNIFICANCE: These results suggested that the metabolite responses to acute submaximal exercise unmasks the exercise performance at different ambient temperatures, highlighting the role of metabolite orchestration in the physiological regulation of CRF.

Swimming Exercise Alleviates Endothelial Mitochondrial Fragmentation via Inhibiting Dynamin-Related Protein-1 to Improve Vascular Function in Hypertension.

BACKGROUND: Regular exercise has been recommended clinically for all individuals to protect against hypertension but the underlying mechanisms are not fully elucidated. We recently found a significant mitochondrial fragmentation in the vascular endothelium of hypertensive human subjects. In this study, we investigated whether exercise could restore endothelial mitochondrial dynamics and thus improve vascular function in hypertension. METHODS: Vascular endothelial mitochondrial morphological alterations were examined in patients with hypertension and hypertensive animal models. Furthermore, swimming exercise-induced endothelial mitochondrial dynamics and vascular function changes were investigated in spontaneously hypertensive rats (SHRs). RESULTS: Mitochondrial fragmentation with an elevated mitochondrial fission mediator Drp1 (dynamin-related protein-1) was observed in the mesenteric artery endothelium from hypertensive patients. A similar mitochondrial fragmentation with increased Drp1 expression were exhibited in the aortic endothelium of angiotensin II-induced hypertensive mice and SHRs. Interestingly, swimming exercise significantly reduced vascular Drp1 expression and alleviated endothelial mitochondrial fragmentation, thus improving blood pressure in SHRs. In cultured endothelial cells, angiotensin II exposure induced Drp1 upregulation, mitochondrial fragmentation and dysfunction, and reduced nitric oxide production, which was blunted by Drp1 genetic reduction or its inhibitor Mdivi-1. Mdivi-1 administration also ameliorated endothelial mitochondrial fragmentation, vascular dysfunction and blood pressure elevation in SHRs while swimming exercise plus Mdivi-1 treatment provided no additional benefits, suggesting that Drp1 inhibition may partially contribute to swimming exercise-conferred anti-hypertensive effects. CONCLUSIONS: These findings suggest that swimming exercise alleviates endothelial mitochondrial fragmentation via inhibiting Drp1, which may contribute to exercise-induced improvement of vascular function and blood pressure in hypertension.

Enhancing stability of aerobic granules by microbial selection pressure using height-adjustable influent strategy.

Optimizing granules size distribution is critical for both reactor performance and stability. In this research, an optimal size range of 1800 to 3000 µm was proposed regarding mass transfer and granules stability based on granules developed at DO around 8.0 mg L-1 with the feed COD:N:P at 100:5:1. A height-adjustable influent strategy was applied to facilitate the nutrient storage of granules at optimum size range via microbial selective pressure. Results suggested insufficient hydraulic shear stress led to overgrowth of granules size. High abundance of filamentous bacteria (Thiothrix sp.) was observed in oversized granules, which detached and affected the remaining granules, resulting in severe sludge bulking. Strong hydraulic shear stress suppressed uncontrolled growth of granules. However, fewer abundance of simultaneous nitrification and denitrification (SND) bacterium was acquired, which led to unfavored SND effect and total nitrogen (TN) removal efficiency. The height-adjustable influent strategy facilitated the poly-ß-hydroxybutyrate (PHB) storage of granules at optimum size range, while limiting the overgrowth of granules size. Additionally, more than 87.51% of total granules situated in optimal sizes range, which led to higher abundance of SND bacterium and higher TN removal efficiency.