Maximum Uptake Rate Research Articles

Specific uptake kinetics of glucose and nitrate in carbon-limited and nitrogen-limited C:N ratio under photoheterotrophic cultural conditions for Botryococcus brauniigrowth and lipid production

Carbon and nitrogen are the most significant parameters for microalgal growth and an effective C:N ratio is critical to assess the biomass and lipid productivities of Botryococcus braunii. In this study, the effect of the C:N ratio on specific uptake kinetics of glucose and nitrate was evaluated using substrate kinetic equation, under glucose limited and nitrate limited photoheterotrophic conditions. In glucose limited conditions, the maximum specific growth rate, biomass and lipid productivity of 0.0873 h−1, 1.11 g L−1 d−1 and 0.390 g L−1 d−1 were observed respectively for C:N ratio of 29:1. Maximum specific nitrate uptake rate of 0.190 mM gb−1 h−1 was observed under glucose limited C:N ratio of 61:1 (i.e. carbon sufficient), while the maximum glucose uptake rate of 0.74 mM gb−1 h−1 was observed in nitrate limited C:N ratio of 13:1 (i.e. nitrogen sufficient). This suggests that carbon and nitrogen metabolism is linked together and significantly affects the specific uptake kinetics of the each other.

Moderate Alcohol Consumption Inhibits Sodium-Dependent Glutamine Co-Transport in Rat Intestinal Epithelial Cells in Vitro and Ex Vivo.

Malnutrition is present in chronic alcoholics. However, how moderate alcohol consumption affects the absorption of nutrients like glutamine has not been investigated. Glutamine, an amino acid, is vital to gastrointestinal health. Glutamine is absorbed via sodium-dependent glutamine co-transport (B0AT1; SLC6A19) along the brush border membrane of absorptive villus cells. Rat intestinal epithelial cells (IEC-18) and sixteen-week-old Sprague Dawley rats were administered the equivalent of a 0.04% blood alcohol content of ethanol (8.64 mM; 2 g/kg) to investigate the effect of moderate alcohol on sodium-glutamine co-transport. Sodium-dependent 3H-glutamine uptakes were performed to measure B0AT1 activity. Inorganic phosphate was measured as a function of Na-K-ATPase activity. Protein expression was analyzed by immunohistochemical and Western blot analysis. Ethanol significantly inhibited sodium-dependent glutamine absorption and Na-K-ATPase activity in enterocytes in vitro and ex vivo. Kinetic studies suggested that the mechanism of inhibition was due to decreased maximal rate of uptake (Vmax) of the B0AT1 co-transporter, corresponding to decreased B0AT1 protein expression and secondary to an inhibited sodium-gradient at the cellular level in vitro and ex vivo. In all, moderate ethanol significantly inhibited glutamine absorption at the level of decreased B0AT1 expression at the brush border membrane and a reduced sodium gradient, which may contribute to malnutrition present in chronic alcoholics.

Physical fitness profile in female horseback riders.

The purpose of the present study was to examine the levels of endurance and neuromuscular performance variables in female horseback riders. 52 female Finnish riders were involved (age 29.4±8.9 yrs, height 1.68±0.06 m, weight 67.5±10.0 kg), 19 show-jumping riders (SJ) and 33 eventing riders (E), riding-time minimum of 4 times/week, jumping level of minimum 1.06±0.11m. The measurements were maximal bilateral isometric leg press force (MVCLP), maximal unilateral isometric knee extension (MVCKE) and flexion forces (MVCKF), countermovement jump (CMJ), maximal isometric force of the trunk extensor and flexor muscles (MVCE, MVCF), weight distribution of the body (WD), handgrip strength (HGS), maximal oxygen uptake (VO2max), lactate threshold (L) and heart rate (HR). Mean force in MVCLP was 1887(±455) N, MVCKE right/left 633(±134)/628(±138) N and MVCKF right/left 420(±79)/411(±74) N, respectively. CMJ height was 19.8(±3.9) cm and trunk forces in MVCE 51.2(±13.7) kg and MVCF 61.3(±11.4) kg. Mean WD in the right/left side was 50.5(±2.2)/49.5(±2.2) % and mean HGS of the right/left hand 39.9(±5.1)/39.2(±4.9) kg, respectively. Mean VO2max in the cycle ergometer test was 32.1(±4.5) mL/kg/min, HRmax 184.5(±9.6) beat/min, timemax to exhaustion 18.50(±2.50) min and Lmax 10.2(±2.1) mmol/L. SJ and E groups did not differ significantly from each other in any of the variables. MVCLP, MVCE and MVCF were at about the same level but VO2max somewhat below compared to non-athletic Finnish women of the same age. It would seem that the present female riders would obtain benefits from additional strength training for both maximal and explosive strength gains.

Opening the black box of plant nutrient uptake under warming predicts global patterns in community biomass and biological carbon storage

The effect of climate change on the amount of carbon stored in the different biological compartments of complex natural communities is relevant for a range of ecosystem functions and services. Temperature‐dependency of many physiological and ecological processes drives this storage capacity. As opposed to other physiological rates, the temperature‐dependence of nutrient uptake by plants has, to date, not been thoroughly investigated and therefore was not explicitly included in food web models. In a meta‐study, we extracted experimental data to establish the temperature‐dependence of the parameters determining plant nutrient uptake. Overall, we found an increase in the maximum uptake rate, as well as the half‐saturation density. As the respiration rates of plants (biomass loss) increase more strongly than the nutrient uptake rates (driving biomass gain under nutrient limitation), our results suggest that warming should decrease plant biomass. We applied these temperature‐dependent nutrient uptake rates by plants to a model of a three‐level food‐chain composed of two nutrients, a plant pool, and an herbivore pool. Having established plant nutrient uptake rates based on real data to replace the previously used assumption of logistic growth, we were able to use realistic natural nutrient deposition rates as the input variables in this model. This mechanistic model approach allowed us to show the quantitative responses of natural communities to realistic fertilization rates for the first time. We ran the model under realistic nutrient supply scenarios based on deposition data from the literature, adding a scenario of anthropogenic fertilization. We found decreases in overall community biomass with increasing temperature, but the intensity of this decrease varied strongly depending on the nutrient supply scenario. Our findings highlight the importance of including other global change drivers besides warming, as they can mediate the temperature impact on changes in global carbon storage and thus biomass‐related ecosystem services.

Factors associated with minimal changes in countermovement jump performance throughout a competitive division I collegiate basketball season

ABSTRACTThe purpose of the study was to assess factors that contribute to countermovement jump (CMJ) performance in women’s basketball athletes. Thirteen female athletes participated and were tested for maximal oxygen uptake (VO2max) and heart rate (HRmax). Athletes were monitored, daily for a total of 21 weeks with heart rate-based wearable devices and CMJ performance and body weight were tested weekly after one day of recovery. 3-jump average height (CMJavg), maximum height jump (CMJmax), and CMJ power (Watts) were calculated and recorded. Playing intensities >85% HRmax, HRavg, HRmax and training load were averaged for three consecutive days prior to the recovery day. After the season, data was grouped as changes in CMJ power from week one: Large (≤ −4.39% change), Moderate (−4.4% to −0.62% change), and Minimal (≥ −0.61% change) changes. Fixed-effects models revealed a main effect of group (p ≤ 0.05) for CMJavg, CMJmax, VO2max, weekly percent changes in body weight and for 3-day training load, HRavg, and playing time at >85% HRmax. When athletes experienced minimal changes in CMJ performance, relative to large changes, they produced greater power, jumped higher, avoided negative changes in weekly body weight, had a greater preseason VO2max and 3-day average workloads appeared to have an impact on CMJ performance

Multi-cycle methane hydrate formation in micro droplets of gelatinous dry solution

A gelatinous dry solution (GDS) was prepared by blending sodium dodecyl sulfate solution, gellan gum powder, and hydrophobic silica nanoparticles in air at a high speed. It is essentially a pile of free-flowing micro surfactant droplets supported by a gelling agent. The GDS has the dispersion characteristics of dry water, activity of the surfactant solution and stability of the gel. The flour-like droplets can provide abundant micro channels for gas transfer, a considerable surface area for gas–liquid contact and stable gel-like structure for repeated hydrate formation. Multi-cycle methane consumption experiments were conducted in a stainless steel vessel at 5.0–8.1 MPa and 273.2 K, in order to study the repeated kinetics of methane hydrate formation in GDS. The results demonstrated that the dispersed GDS facilitated rapid and reversible methane storage in clathrate hydrate by enhancing the gas–liquid contact and the stability of the regular droplets. Methane uptake (152.2–163.2 m3·m−3) and maximum uptake rates (4.522–5.690 m3·m−3·min−1) were achieved in the first storage cycle at the experimental pressures. GDS maintained relatively high methane storage capacities (114.3–118.0 m3·m−3) until the ninth cycle, and the capacities only were attenuated by 24.92–27.70% with respect to the first cycle at the above pressures. A hypothesis of “droplets breakage by released gas” was proposed to illustrate the attenuation of gas storage capacity of the droplets.

T. Obliquus Cultivation Under Heterotrophic Conditions: Determination of Growth Parameters

Microalgae are a promising feedstock for the future of the industrial chemistry. Among microalgae, Tetradesmus obliquus (generally known as Scenedesmus obliquus) is one of the most studied species due to its robustness and its good performances for production of lipids, proteins and carbohydrates. However, the high production costs still limit large part of the possible applications. The exploitation of the heterotrophic metabolism for microalgae cultivation may potentially improve the biomass production sustainability, especially if organic substrates are obtained from wastewaters. However, this latter strategy has technical limits given by the issue of contamination by bacteria, which have growth rates ~ 10 folds higher than microalgae.The estimation of the microalgae growth parameters could allow optimization of the feeding strategy by which wastewaters are supplied to microalgae culture, and consequently, bacteria contamination minimization.In this work, an axenic culture of T. obliquus was isolated by a sonication pre-treatment followed by an incubation in solid media containing ampicillin (0.1 mg mL-1), penicillin (67 U mL-1) and streptomycin (0.07 mg mL-1). The axenic strain was then cultivated in heterotrophic condition under N-replete and N-starvation. Experimental data of biomass production and nitrogen consumption were well predicted by the Droop model. By means of the model fitting with experimental data, the optimal values for maximum theoretical growth rate ( µ ), maximum nitrogen quota (qmax), minimum nitrogen quota (qmin) and maximum nitrogen uptake rate (?max) were estimated.By estimating, in the future, the growth parameters also for other substrates and for contaminant microorganisms, a more effective wastewater supply strategy can be developed.

Nanostructured Membrane of Sodium Montmorillonite Reinforced Cellulose Acetate for Adsorption of Ca(II) and Mg(II) Ions in Hard Water

Permanent hard water softening was conducted with the use of cellulose acetate (CA)/sodium montmorillonite (Na+-MMT) nanostructured membranes. Fabrication of the nanostructured membranes with various Na+-MMT loading (0%, 5%, 10%, 15%) was made possible by electrospinning technique, which was carried out at 25°C, 30 kV applied voltage, needle size of 25G and a tip to collector distance of 18 cm. The effect of Na+-MMT content on the morphology of the fiber was examined with the use of Scanning Electron Microscope (SEM). It was determined that increasing the Na+-MMT loading decreases the average fiber diameter. The molecular structure of the blend nanostructured membranes were investigated using Fourier Transform Infrared (FTIR) Spectroscopy and the existence of CA and Na+-MMT in the electrospun nanostructured membrane was confirmed. Better adsorption performance was observed for the blend with 15% Na+-MMT as compared to pure CA and maximum uptake rate was attained at 7 hours for pure CA and only 5 hours for CA/Na+-MMT (85%/15%) blend. Increasing the initial hard water concentration increases the driving force for diffusion and in turn increases adsorption capacity of both pure CA and the CA/Na+-MMT (85%/15%) blend. More so, the results of the experiment best fitted the pseudo-second order kinetic model and the Freundlich isotherm model. Integration of Na+-MMT in CA increases the surface area for adsorption of the nanostructured membrane, and thus, could be used as an effective adsorbent for hard water softening.

Neuroinflammation and amyloid-beta 40 are associated with reduced serotonin transporter (SERT) activity in a transgenic model of familial Alzheimer\u2019s disease

BackgroundDiscrepant and often contradictory results have accumulated regarding the antidepressant and pro-cognitive effects of serotonin transporter (SERT) antagonists in Alzheimer’s disease.MethodsTo address the discrepancy, we measured the activity and density of SERT in the neocortex of 3–24-month-old APPswe/PS1dE9 and wild-type littermate mice, by using [3H]DASB autoradiography and the [3H]5-HT uptake assay. Levels of soluble amyloid-β (Aβ), and pro-inflammatory cytokines that can regulate SERT function, such as interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor (TNF), were measured in parallel. Neuroinflammation in aging APPswe/PS1dE9 mice was further evaluated by [3H]PK11195 autoradiography.ResultsDecreased SERT density was observed in the parietal and frontal cortex of 18–24-month-old APPswe/PS1dE9 mice, compared to age-matched, wild-type animals. The maximal velocity uptake rate (Vmax) of [3H]5-HT was reduced in neocortical preparations from 20-month-old transgenic vs. wild-type mice. The reduction was observed when the proportion of soluble Aβ40 in the Aβ40/42 ratio increased in the aged transgenic brain. At concentrations compatible with those measured in 20-month-old APPswe/PS1dE9 mice, synthetic human Aβ40, but not Aβ42, reduced the baseline Vmax of [3H]5-HT by ~ 20%. Neuroinflammation in APPswe/PS1dE9 vs. wild-type mice was evidenced by elevated [3H]PK11195 binding levels and increased concentration of IL-1β protein, which preceded the reductions in neocortical SERT density and activity. Age-induced increases in the levels of IL-1β, IL-6, and TNF were observed in both transgenic and wild-type animals.ConclusionsThe progression of cerebral amyloidosis is associated with neuroinflammation and decreased presynaptic markers of serotonergic integrity and activity. The Aβ40-induced reduction in the uptake kinetics of [3H]5-HT suggests that the activity of SERT, and potentially the effects of SERT antagonism, depend on the levels of interstitial Aβ40.

Genome size reduction: design and analysis of a minimal metabolic network for yeast

The issue of genome minimization for a living cell has been the subject of intense study, and raises important theoretical questions and practical opportunities. We have developed an in-silico methodology, based on genome-scale models, to minimize the number of active genes encoding enzymes and transporters in a cell’s metabolic network. In the resultant minimal metabolic networks, all the remaining active genes are essential for keeping the network working to achieve the biomass value predicted by Flux Balance Analysis. We have tested our approach on a set of genome-scale metabolic models of various eukaryotic and prokaryotic organisms, but have focussed on Saccharomyces cerevisiae. The nutrient environments employed have comprised both known and automatically generated sets of nutrients and relative maximum uptake rates. The results generate more than 1000 unique minimal networks for a single condition, demonstrating the complexity of the minimization problem. We then performed a frequency analysis on the affected genes to discover patterns or similarities among the networks and the redundancy of specific pathway-related genes. In addition to this, we also evaluated the networks using a pathway-oriented robustness analysis, to see how the networks respond to random variation in the reaction fluxes. Finally, we have done a cross-species comparison of our algorithm’s results to highlight some of the homologous genes that are retained in the networks of a majority of species. Thus, our work has produced a tool for in silico genome minimization that permits the discovery of mandatory genes in the minimal metabolic networks.

High cell density culture of baker's yeast FX-2 based on pH-stat coupling with respiratory quotient.

The high cell density culture of baker's yeast FX-2 was investigated in a 50 L(A) automatic bioreactor. Herein, it was found firstly that the Crabtree effect clearly existed in batch fermentation with higher glucose content, then the critical initial glucose content range (≤2.00 gL-1 ) was reasonably ascertained to effectively avoid Crabtree effect. In the next fed-batch fermentations with different strategies, the second strategy (maintain ethanol concentration lower than 0.10% and pH around 4.80) was confirmed to be more beneficial to yeast growth than the first strategy (keep reducing sugar not more than 2.00 gL-1 and control steady Carbon/Nitrogen ratio 3.05:1.00). After that, one optimal control strategy (maintain pH around 4.80 and keep respiratory quotient in the range of 0.90-1.00) was constructed to further enhance cell yield. Under an optimal control strategy, four schemes with the aim of achieving pH-stat were compared, and yeast extract instead of other alkaline materials was selected as a better regulator. As a result, 148.37 gL-1 dry cell weight, 38.25 × 108 mL-1 living cells, and 8.24 gL-1 h-1 productivity were harvested, which respectively elevated 23.74%, 135.38%, and 24.47% compared to that obtained under the traditional scheme (regulate pH with ammonia); meanwhile, the maximum oxygen uptake rate and carbon dioxide excretion rate were both more than 250.00 mmolL-1 min-1 .

Nutrient affinity, half-saturation constants and the cost of toxin production in dinoflagellates.

The two parameters of the Michaelis-Menten model, the maximum uptake rate and the half-saturation constant, are not stochastically independent, and the half-saturation constant is not a measure of nutrient affinity, as commonly assumed. Failure to realise their interdependence and mechanistic interpretation may lead to the emergence of false trade-offs.

Aerobic performance of two tropical cephalopod species unaltered by prolonged exposure to projected future carbon dioxide levels.

Squid and many other cephalopods live continuously on the threshold of their environmental oxygen limitations. If the abilities of squid to effectively take up oxygen are negatively affected by projected future carbon dioxide (CO2) levels in ways similar to those demonstrated in some fish and invertebrates, it could affect the success of squid in future oceans. While there is evidence that acute exposure to elevated CO2 has adverse effects on cephalopod respiratory performance, no studies have investigated this in an adult cephalopod after relatively prolonged exposure to elevated CO2 or determined any effects on aerobic scope. Here, we tested the effects of prolonged exposure (≥20% of lifespan) to elevated CO2 levels (~1000μatm) on the routine and maximal oxygen uptake rates, aerobic scope and recovery time of two tropical cephalopod species, the two-toned pygmy squid, Idiosepius pygmaeus and the bigfin reef squid, Sepioteuthis lessoniana. Neither species exhibited evidence of altered aerobic performance after exposure to elevated CO2 when compared to individuals held at control conditions. The recovery time of I. pygmaeus under both control and elevated CO2 conditions was less than 1hour, whereas S. lessoniana required approximately 8hours to recover fully following maximal aerobic performance. This difference in recovery time may be due to the more sedentary behaviours of I. pygmaeus. The ability of these two cephalopod species to cope with prolonged exposure to elevated CO2 without detriment to their aerobic performance suggests some resilience to an increasingly high CO2 world.

Tumor Chemo-Radiotherapy with Rod-Shaped and Spherical Gold Nano Probes: Shape and Active Targeting Both Matter.

The morphologies of gold nanoparticles (NPs) affect their tumor accumulation through enhanced permeability and retention effect. However, detailed information and mechanisms of NPs' characteristics affecting tumor accumulation are limited. The aim of this study is to evaluate the effects of shape and active targeting ligands of theranostic NPs on tumor accumulation and therapeutic efficacy, and to elucidate the underlying mechanism.Methods: αvβ3 integrin-targeted, cisplatin-loaded and radioisotope iodine-125 labeled spherical and rod-shaped gold nano theranostic probes (RGD-125IPt-AuNPs and RGD-125IPt-AuNRs) with similar sizes were fabricated and characterized. The in vivo distribution and chemo-radio therapeutic efficacy against tumors of these newly developed probes were subsequently evaluated. Moreover, a physiologically based pharmacokinetic (PBPK) model was developed to characterize the in vivo kinetics of these probes at the sub-organ level, and to reveal the mechanism of NPs' shape and active targeting ligands effects on tumor accumulation.Result: Cisplatin and iodine-125 were loaded sequentially onto the NPs through a thin polydopamine coating layer on the NPs. Both RGD-125IPt-AuNPs and RGD-125IPt-AuNRs exhibited high specificity for αvβ3 in vitro, with the rod-shaped probe being more efficient. The PBPK model revealed that rod-shaped gold NPs diffused more rapidly in tumor interstitial than the spherical ones. Tumor accumulations of non-targeted and rod-shaped RAD-125IPt-AuNRs was higher in short term (1 h post injection), but not pronounced and similar to that of non-targeted spherical RAD-125IPt-AuNPs in 24 h after intravenous injection, revealing that the NPs' shape did not have a significant impact on tumor accumulations through enhanced permeability and retention (EPR) effect in long-term. While for actively targeted NPs, in addition to a higher distribution coefficient, RGD-125IPt-AuNRs also had a much higher tumor maximum uptake rate constant than RGD-125IPt-AuNPs, indicating both the shape and active targeting ligands affected the tumor uptake of rod-shaped NPs. As a result, RGD-125IPt-AuNRs had a more effective inhibition of tumor growth than RGD-125IPt-AuNPs by chemo-radiationtherapy.Conclusion: Our study suggests that both the shape and active targeting ligands of gold NPs play important roles on tumor accumulation and chemo-radio therapeutic effect.

BIOSORPTION OF CU (II) BY SCENEDESMUS OBLIQUUS: OPTIMIZATION IN PHOVASOLI HAEMOTOCOCCUS MEDIUM

Biosorption of copper (Cu2+) in electroplating wastewater by biosorbent using Scenedesmusobliquus green algae has been investigated in the artificial medium of Phovasoli Haemotococcus Medium (PHM). The study aims to find an alternative for the treatment of wastewater containing copper (Cu2+) using S.obliquus as a biosorbent, uses a batch test with various pH 4, 5, 6, 7 and 8 as well as the various contact time of 60, 120, 180, 240 and 300 minutes. Some ratios of wastes versus nutrients (Cu2+ : nutrient) in the treatment were A (1: 3), B (1: 1), C (3: 1) and D (100% of waste) with the initial concentration respectively, A (5.05 mg/L), B (16.54 mg/L), C (21.85 mg/L) and D (30.28 mg/L) at 28°C ± 2. The results of the study show that the biosorption rate and the abilities of the sorbent are influenced by pH and contact time (adsorption rate). The maximum uptake rate for Cu2+ was obtained at pH 6 in 240 minutes. In the ratio of waste: nutrient = 1: 3, the uptake rate was 65.54% ± 8.04 while when 100% waste, the uptake rate was 41.99% ± 1.01. The adsorption of copper (Cu2+) is due to the destruction of the cell wall. Analysis of Fourier Transform Infrared (FTIR) shows the adsorption band of functional groups such as carboxyl, amine, and alkene. It indicates the interaction between S.obliquus and the copper ion (Cu2+). The adsorption process of this study follows the Freundlich isotherm equation.

Lipid acquisition and tissue storage in hagfish: new insights from an ancient vertebrate.

Hagfishes are ancient vertebrates, which have the ability to tolerate nearly a year of food deprivation with energy during fasting maintained using lipid stores. While lipid transporters are evolutionarily conserved, there are relatively few studies examining mechanisms of lipid acquisition in teleosts and no reports in the primitive and evolutionarily important agnathans. We examined tissue lipid droplet distribution and used gut sac preparations to characterize uptake mechanisms of the monounsaturated fatty acid, oleic acid (OA; 18:1 cis-9), in the Pacific hagfish. OA absorption was carrier-mediated and demonstrated saturable concentration-dependent uptake with an affinity constant of 55 ± 7µM, and a maximal rate of uptake of 1311 ± 97pmol cm- 2h- 1. Additionally, regulation of intestinal transport was demonstrated as feeding significantly increased uptake. To further examine post-prandial effects on fatty acid transport, hagfish were dosed with bovine insulin, which had no effect on OA intestinal acquisition, but did lower plasma glucose. Overall, this is the first evidence for intestinal fatty acid acquisition in an agnathan, which are ideal models for understanding the evolution of nutrient transport processes in vertebrates, and are particularly suited to lipid research owing to their dependence upon this energy source during prolonged periods of fasting.

Chive (Allium schoenoprasum L.) response as a phytoextraction plant in cadmium-contaminated soils.

Cadmium (Cd) soil contamination poses a major hazard to safe food production throughout the world, calling upon actions for decontamination using environmentally friendly methods, such as phytoextraction. In this study, the capability of chive (Allium schoenoprasum L.) for phytoextracting Cd from contaminated soils was tested. Growth of chive was studied in a soil spiked with 0, 15, 30, 60, and 120mg Cd/kg soil, and then, concentrations of Cd in soil, plant shoots, and roots were measured after harvest. Chive dry matter production was not affected significantly by the different Cd levels in soil, except from the maximum Cd concentration (120mg Cd/kg soil), where dry matter was reduced by 77%. Cadmium accumulation occurred mostly in roots rather than in shoots, with maximum Cd concentrations 482.48 and 26.65mg/kg of dry matter, respectively. Translocation factor (the proportion of Cd concentration in the aerial plant parts to that in the roots) was below 1 in all contaminated levels and decreased with increasing Cd concentrations in soil, indicating low Cd reallocation from roots to shoots. Maximum amount of Cd absorption (Cd concentration in shoots), maximum contaminant uptake rate, and minimum clean-up time were all observed in Cd concentration 60mg/kg soil. Based on chive potential to acquire Cd in its roots and shoots, it can be designated as a convenient species for reducing Cd from contaminated soils up to concentrations of 60mg Cd/kg soil.

A Randomized Crossover Study Investigating the Running Economy of Highly-Trained Male and Female Distance Runners in Marathon Racing Shoes versus Track Spikes.

Running economy represents a complex interplay of physiological and biomechanical factors that are able to adapt chronically through training, or acutely through other interventions such as changes in footwear. The Nike Vaporfly (NVF) shoe was designed for marathon running on the roads and has been shown to improve running economy by ~ 4% compared with other marathon shoes, however, during track racing, distance runners traditionally wear a much lighter shoe with an embedded spike plate around the forefoot. The aim of this study was to determine if, and to what extent, the NVF shoes improve running economy compared with established track spikes (Nike Zoom Matumbo 3 [NZM]) and marathon racing shoes (Adidas Adizero Adios 3 [ADI]). Twenty-four highly-trained runners (12 male, 12 female) ran 4 × 5min trials on a treadmill while wearing each of the four shoe conditions: NVF, NZM, ADI, and the NVF matched in weight to the ADI shoe (NVF +), during three separate visits-visit 1: familiarization; visit 2: 14 and 18km·h-1 for men, 14 and 16km·h-1 for women; visit 3: 16km·h-1 for men, 15km·h-1 for women, plus a maximal rate of oxygen uptake (VO2max) test for both sexes. We measured the rates of oxygen uptake (VO2), carbon dioxide production and biomechanical measures while running at each velocity and shoe condition. The NVF shoe improved running economy by 2.6 ± 1.3% compared with the NZM, 4.2 ± 1.2% compared with ADI, and 2.9 ± 1.3% when matched in weight of the ADI shoe. Among the 24 subjects, the difference in running economy over the four velocities between the NVF and NZM shoes ranged from +0.50 to -5.34%, and -1.72 to -7.15% for NVF versus ADI. Correlations between changes in running economy and changes in biomechanical variables were either trivial or small, but unclear. The NVF enhanced running economy compared with track spikes and marathon shoes, and should be considered a viable shoe option for track and road racing.

PO-149 Taekwondo Exercise Improving Cardiopulmonary Function of Female College Students after 16 Weeks Intervention

Objective Taekwondo is one of the popular exercise styles to promote aerobic endurance for college students because of its combination of hands and feet and simple technology and interesting. This study observed the effect of Taekwondo on the cardiopulmonary function of female college students, trying to find the best heart rate in the teaching class of Taekwondo and evaluate the effect of maximal oxygen uptake and improve the basic theory of Taekwondo exercise to enhance students' aerobic endurance and provide theoretical reference for scientific methods to improve classroom practice intensity.
 Methods 1)This study used heart rate telemetry to perform a time domain analysis of heart rate variability in 10 university students in the Taekwondo class. The indicators used in the time domain analysis are: average RR interval value, standard deviation of RR interval (SDNN), standard deviation of the average of every 5 minutes R-R interval (SDANN), and standard deviation of R-R interval every 5 minutes The mean value (SDNNindex), the difference between adjacent NNs> the percentage of the number of total sinus beats per 50 ms (PNN50). By analyzing the information of these indicators, the sympathetic and vagal nerves are balanced. 2) The maximum oxygen uptake and respiratory exchange rate of 10 female college students were measured by the treadmill exercise load per breath method. The cardiopulmonary function of female college students was assessed by cardiopulmonary function indicators and heart rate variability indicators.
 Results 1) The R-R interval value, the mean value of the R-R interval standard deviation (SDNNindex), and the standard deviation (SDANN) of the R-R interval mean value per 5 min were increased after exercise intervention. The three indicators increased by 438.22ms, 0.87ms, and 64.67 ms, respectively; The standard deviation of the R-R interval (SDNN), the difference between adjacent NNs >50ms, the percentage of total sinus beats (PNN50) decreased.They dropped by 44.23ms and 0.06% respectively. With the increase of the sports load of Taekwondo students, the heart rate variability gradually decreases, showing a decline in the vagus nerve tension of female college students.2) The average relative oxygen uptake of female college students before the start of the course was 30.7ml (kg*min), 35 ml (kg*min) after the intervention, and the maximum oxygen uptake increased by 14.01%. The average respiratory exchange rate of female college students before the start of the course was 1.26, 1.28 after the course intervention, and the respiratory exchange rate increased by 1.59%.
 Conclusions 1) Taekwondo exercise reduces the heart rate variability of female college students, and long-term exercise can enhance the ability of the vagus nerve to control the heart. 2) Increased maximal oxygen uptake and respiratory exchange rate of female college students through Taekwondo course intervention.After a long period of Taekwondo exercise, it can effectively improve the aerobic endurance of college students and improve their cardiopulmonary function.（NSFC：31401018 SKXJX2014014).

The effects of recovery duration on physiological and perceptual responses of trained runners during four self-paced HIIT sessions

ObjectivesThis study aimed to examine the effects of different recovery durations on self-selected running velocities, physiological responses, and ratings of perceived exertion (RPE) in a commonly used high intensity interval training (HIIT) protocol. Design & methodsTwelve trained runners performed an incremental treadmill exercise test to determine maximal oxygen uptake (V˙O2max) and heart rate (HRmax). In four subsequent visits, participants performed a HIIT session comprising six 4-min work intervals, in which the recovery duration between work intervals equalled either a fixed (1MIN, 2MIN, 3MIN) or a self-selected duration (ssMIN). HIIT sessions were run on a non-motorized treadmill, and were performed under isoeffort conditions. ResultsMean running velocity was significantly higher in 3MIN compared with all other protocols, and higher in ssMIN compared with 2MIN. No significant differences in time spent ≥90% and 95% V˙O2max, or ≥90% and 95% HRmax were evident between the four protocols. RPE responses were similar across and within the protocols showing a gradual increase with each progressive interval. ConclusionIn a self-paced HIIT session of six 4-min work intervals, the length of recovery durations had a limited effect on the total physiological strain endured in the training. However, running velocities were higher when participants received the longest recovery period (3MIN). Longer recovery durations may facilitate a higher external training load (faster running), whilst maintaining a similar internal training load (physiological stimulus), and may therefore allow for greater training adaptations.