The effects of arsenic and induced-phytoextraction methods on photosynthesis in Pteris species with different arsenic-accumulating abilities

Arsenic (As) accumulation and photosynthesis occur simultaneously in plants under As exposure. We investigated the effects of As and induced-phytoextraction methods on photosynthesis in two As hyperaccumulators (Pteris vittata and Pteris cretica var. nervosa) and two non-hyperaccumulators (Pteris semipinnata and Pteris ensiformis) under soil culture conditions. Chlorophyll fluorescence parameters (the maximum [F_v/F_m] and actual quantum efficiency [F_PSII]) and the activities of three photosynthetic enzymes (ATPase, ribulose-1, 5-bisphosphate carboxylase [RuBPC] and glyceraldehyde-3-phosphate dehydrogenase [GAPDH]) were measured. Arsenic accumulation and photosynthetic behaviours in response to enhanced-phytoextraction methods (trans-1, 2-cyclobexylenedinitrilotetraacetic acid [CDTA] and phosphorous [P] addition and soil pH adjustment) of P. cretica and P. semipinnata were monitored and compared under conditions of 100 mg As kg⁻¹. Significant decreases in the F_v/F_m (19.9%) and F_PSII (36.1%) were observed in P. vittata when exposed to 100 mg As kg⁻¹ in comparison to the control (0 mg As kg⁻¹). Compared to the control (0 mg As kg⁻¹), the activities of GAPDH increased by 0.5% in P. cretica var. nervosa and decreased by only 8.3% in P. vittata even when both of them were treated with 200 mg As kg⁻¹, whereas a significant decrease, 56.1% and 51.7%, of this enzyme was observed in P. semipinnata and P. ensiformis, respectively, when exposed to 50 mg As kg⁻¹. Compared to the control (0 mg CDTA kg⁻¹ or 0 mg P kg⁻¹), the activities of ATPase increased by 53.7% and 82.7% in P. cretica when exposed to 0.5 g CDTA kg⁻¹ and 50 mg P kg⁻¹, respectively, and an increase of up to 175% was also observed in P. semipinnata when exposed to 600 mg P kg⁻¹. The activities of GAPDH increased by 68.9% and 90.7% in P. cretica when exposed to 2 g CDTA kg⁻¹ and 600 mg P kg⁻¹, respectively, but a decrease of up to 60% was observed in P. semipinnata when exposed to 2 g CDTA kg⁻¹. The uptake of As in P. semipinnata increased by 80.9% and 73.3% when 1 g CDTA kg⁻¹ and 600 mg P kg⁻¹ were added, respectively, compared to the control (0 g CDTA kg⁻¹ or 0 mg P kg⁻¹). It was concluded that GAPDH played an important role in the photosynthesis of As hyperaccumulators under As treatments.     

Cholesterol enrichment of rabbit platelets enhances the Ca2 + entry pathway induced by platelet-derived secondary feedback agonists

AimsHypersensitivity of platelets due to increased platelet cholesterol levels has been reported in hypercholesterolemia. However, the signaling pathways linking increased platelet reactivity and cholesterol contents are not fully understood. This study aims to determine the direct effect of cholesterol enrichment of platelets on the pathways including Ca^2 + mobilization and secondary feedback agonists such as adenosine diphosphate (ADP) and thromboxane A₂ (TXA₂).Main methodsIn vitro cholesterol enrichment of rabbit platelets was performed by incubation with cholesterol complexed with methyl-β-cyclodextrin. Ca^2 + mobilization was monitored using platelets loaded with fura-PE3/AM, a fluorescent calcium indicator. Released ATP and TXB₂ from platelets were measured by a luciferin–luciferase ATP assay system and a TXB₂ ELISA Kit, respectively.Key findingsCholesterol enrichment of rabbit platelets significantly enhanced Ca^2 + mobilization induced by thrombin, accompanying an augmented Ca^2 + entry. The augmentation of Ca^2 + entry by cholesterol enrichment was significantly suppressed by treatment with inhibitors for secondary feedback agonists. In cholesterol-enriched platelets, the amount of released ATP or TXB₂ induced by thrombin was not significantly altered in comparison with control platelets, whereas an increase in [Ca^2 +]_i induced by ADP or U46619, a TXA₂ mimetic, was significantly enhanced.SignificanceThese results suggest that cholesterol enrichment of rabbit platelets results in enhanced Ca^2 + mobilization via ADP/TXA₂-dependent augmentation of the Ca^2 + entry pathway. The results reveal a novel mechanism by which platelet hypersensitivity is regulated by cholesterol contents.     

Yangyin Tongnao granules enhance neurogenesis in the peri-infarct area and upregulate brain-derived neurotrophic factor and vascular endothelial growth factor after focal cerebral ischemic infarction in rats

Yangyin Tongnao granules (YYTNG) have been extensively applied in the treatment of brain injury, mainly due to its antioxidant effects, inhibition of apoptosis, and enhancement of blood circulation. To analyze the effect of YYTNG on the recovery of neurological function and neurogenesis in the peri-infarct area after cerebral ischemic infarction in rats and to elucidate its role in the neuroprotective mechanism of stroke, Sprague–Dawley (SD) rats were subjected to middle cerebral artery occlusion (MCAO) for 90 min followed by reperfusion. Rats were randomly divided into five groups: sham, MCAO, and YYTNG-treated rats given doses of 0.83, 1.65, or 3.3 g kg^?1 day^?1. The YYTNG-treated groups (1.65 and 3.3 g kg^?1 day^?1) showed higher neurological scores and a lower infarct volume than the MCAO group on day 3 after MCAO. Furthermore, the YYTNG-treated groups (0.83, 1.65, and 3.3 g kg^?1 day^?1) showed higher neurological scores on day 7 after MCAO. The number of BrdU⁺/nestin⁺, BrdU⁺/NeuN⁺, and BrdU⁺/GFAP⁺ cells in the peri-infarct area 7 days after MCAO was significantly increased in the YYTNG-treated groups in a dose-dependent manner. The protein expression levels of brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) were significantly higher in all three YYTNG-treated groups than in the MCAO group. Based on these results, administration of YYTNG post ischemia could ameliorate neurological function deficits in rats with MCAO. The therapeutic effect of YYTNG may be due to the promotion of neurogenesis in the peri-infarct area and the upregulation of neuroprotective factors BDNF and VEGF in MCAO rats.

     

Effect of dipyridamole of prostaglandin generation by human platelets and vessel walls

These experiments were conducted to determine the effects of dipyridemole on human platelet aggregation, platelet thromboxane A₂ (TXA₂) and human vessel wall prostacyclin (PGI₂) generation. Dipyridamole in varying concentrations (5 to 50 μg/ml) had no direct effect on ADP-induced platelet aggregation in vitro, but it potentiated PGI₂-induced platelet aggregation inhibition at these concentrations. Dipyridamole also inhibited arachidonic acid-induced platelet TXA₂ generation at these concentrations. In continuously perfused umbilical vein segments, dipyridamole treatment resulted in stimulation of PGI₂ release determined by bioassay and by measurement of its stable metabolite 6-keto-PGF_1α. Minimum concentration of dipyridamole causing PGI₂ release was 50 μg/ml. These in vitro studies suggest that anti-thrombotic effects of dipyridamole in man are mediated mainly by potentiation of PGI₂ activity and to some extent by TXA₂ suppression. Stimulation of PGI₂ release by human vessels may not be seen in usual therapeutic concentrations.     

Two ways to achieve an anammox influent from real reject water treatment at lab-scale: Partial SBR nitrification and SHARON process

A comparative study to produce the correct influent for Anammox process from anaerobic sludge reject water (700–800 mg NH₄⁺-N L⁻¹) was considered here. The influent for the Anammox process must be composed of NH₄⁺-N and NO₂⁻-N in a ratio 1:1 and therefore only a partial nitrification of ammonium to nitrite is required. The modifications of parameters (temperature, ammonium concentration, pH and solid retention time) allows to achieve this partial nitrification with a final effluent only composed by NH₄⁺-N and NO₂⁻-N at the right stoichiometric ratio. The equal ratio of HCO₃⁻/NH₄⁺ in reject water results in a natural pH decrease when approximately 50% of NH₄⁺ is oxidised. A Sequencing batch reactor (SBR) and a chemostat type of reactor (single-reactor high activity ammonia removal over nitrite (SHARON) process) were studied to obtain the required Anammox influent. At steady state conditions, both systems had a specific conversion rate around 40 mg NH₄⁺-N g⁻¹ volatile suspended solids (VSS) h⁻¹, but in terms of absolute nitrogen removal the SBR conversion was 1.1 kg N day⁻¹ m⁻³, whereas in the SHARON chemostat was 0.35 kg N day⁻¹ m⁻³ due to the different hydraulic retention time (HRT) used. Both systems are compared from operational (including starvation experiments) and kinetic point of view and their advantages/disadvantages are discussed.     

Dose-related effects of low dose aspirin on hemostasis parameters and prostacyclin/thromboxane ratios in late pregnancy

Background: The purpose of this study was to determine which low dose of low dose aspirin (LDA) optimized the urinary prostacyclin (PGI₂)/thromboxane (TXA₂) ratio and minimized evidence of platelet aggregation during normal late pregnancy.Methods: Twelve women with uncomplicated singleton pregnancies between 28 and 34 weeks gestation participated in a randomized blinded study. Blood samples for salicylate levels were obtained pretreatment, 4 hours and 7 days after administration of placebo, 20mg, 40mg or 80mg of aspirin. Twenty-four hour urine specimens collected at the same intervals were assayed for PGI₂ and TXA₂ metabolites. In addition, bleeding time and platelet aggregation studies were performed prior to and after 7 days of LDA or placebo.Results: A dose-related increase in bleeding time occurred with 40 mg and 80 mg of LDA, but not with the 20 mg dose or placebo. Platelet aggregation studies changed progressively from a normal baseline to abnormal with an increasing dose of LDA. The ratio increased with aspirin doses as low as 20mg, with a decrease in TXA₂ metabolites but not in PGI₂ metabolites. Serum salicylate was not detectable in any sample from any patient.Conclusion: There are dose-related changes in platelet aggregation and bleeding times with progressively increasing doses of LDA. A lower dose of LDA, such as 20–40 mg per day, may be as efficacious as higher doses in the prophylaxis of pre-eclampsia in high risk populations.     

Testing the “redirection hypothesis” of prostaglandin metabolism in the kidney

Furosemide increases the synthesis of two major renal eicosanoids, prostacylin (PGI₂) and thromboxane A₂ (TXA₂), by stimulating the release of arachidonic acid which in turn is metabolized to PGG₂/PGH₂, then to PGI₂ and TXA₂. PGI₂ may mediate, in part, the early increment in plasma renin activity (PRA) after furosemide. We hypothesized that thromboxane synthetase inhibition should direct prostaglandin endoperoxide metabolism toward PGI₂, thereby enhancing the effects of furosemide on renin release. Furosemide (2.0 mg.kg⁻¹ i.v.) was injected into Sprague-Dawley rats pretreated either with vehicle or with U-63, 557A (a thromboxane synthetase inhibitor, 2 mg/kg⁻¹ followed by 2 mg/kg⁻¹.hr⁻¹). Urinary 6ketoPGF₁ α and thromboxane B₂ (TXB₂), reflecting renal synthesis of PGI₂ and TXA₂, as well as PRA and serum TXB₂, were measured. Serum TXB₂ was reduced by 96% after U-63, 557A. U-63, 557A did not affect the basal PRA. Furosemide increased PRA in both vehicle and U63, 557A treated rats. However, the PRA-increment at 10, 20 and 40 min following furosemide administration was greater in U-63, 557A-treated rats than in vehicle-treated rats and urine 6ketoPGF₁ α excretion rates were increased. These effects of thromboxane synthesis inhibition are consistent with a redirection of renal PG synthesis toward PGI₂ and further suggest that such redirection can be physiologically relevant.     

Effects of osmotic pressure on recombinant BHK cell growth and von willebrand factor (vWF) expression

The effects of osmotic pressure were investigated on cell growth and von willebrand factor (vWF) expression in batch culture, pulse culture and adaptive culture of recombinant baby hamster kidney (rBHK) cells. Intracellular contents of some amino acids including aspartic acid, glycine, arginine, alanine, valine and serine in adaptive culture showed a significant increase with environmental osmotic pressure and became steady after 6 h adaptation. There was little change in intracellular concentrations of amino acids in a control cultivation under 330 mOsmol kg⁻¹. With the increase of osmotic pressure from 330 to 350 mOsmol kg⁻¹, the specific growth rate of rBHK cells remained kept constant. However, the growth of rBHK cells was seriously inhibited under 370 mOsmol kg⁻¹. When gradually increasing the osmotic pressure from 370 to 470 mOsmol kg⁻¹ over more than 6 h, the specific growth rate of rBHK cells could increase by 40% in comparison with that when directly increasing within the same range. High osmotic pressure hardly effected any change in the percent of both cells during G₀/G₁ phase and apoptotic cells in the cell population, but the percentage of cells during S phase in the cell population increased. Higher osmotic pressure (470 mOsmol kg⁻¹) could inhibit the expression of vWF, although at 370 mOsmol kg⁻¹ the specific production rate of vWF was 47% higher than that in 330 mOsmol kg⁻¹.     

Enabling Fluorine-Free Lithium-Ion Capacitors and Lithium-Ion Batteries for High-Temperature Applications by the Implementation of Lithium Bis(oxalato)Borate and Ethyl Isopropyl Sulfone as Electrolyte

A novel fluorine-free electrolyte comprising a solution of lithium bis(oxalato)borate in ethyl isopropyl sulfone is presented. It is characterized by its safety and non-toxic properties, along with the capability to effectively suppress the anodic dissolution of aluminum. Successful high-temperature application of this electrolyte in combination with various capacitor- and battery-like electrode materials is shown. Further utilization in a lithium-ion capacitor and a lithium-ion battery is demonstrated. To the best of the knowledge, the lithium-ion capacitor presented in this work represents the first entirely fluorine-free device suitable for high-temperature applications. When operating at 60 °C, this device delivers a maximum energy output of 169 Wh kg⁻¹_AM at a power of 200 W kg⁻¹_AM and even 80 Wh kg¹_AM at 10 kW kg^-1_AM, along with the ability to retain 80% of its initial capacitance after 3500 cycles at 5 A g⁻¹. As such, this novel electrolyte is a promising alternative to conventional fluorine-containing configurations since its performance is capable to match or even surpass that of most similar laboratory-scale LICs.     

Evaluation of phosphorus distribution and bioavailability in sediments of a subtropical wetland reserve in southeast China

The phosphorus (P) fractions and bioavailable P in the sediments from the Quanzhou Bay Estuarine Wetland Nature Reserve were investigated using chemical extraction methods for the first time to study the distribution and bioavailability of P in the reserve sediments. A hypothesis was presented suggesting that the bioavailable P in the sediments could be evaluated using the P fractions. The total phosphorus (TP), inorganic phosphorus (IP), organic phosphorus (OP), non-apatite phosphorus (NAIP), and apatite phosphorus (AP) contents in the sediments were in the ranges of 303.87–761.59 mg kg⁻¹, 201.22–577.66 mg kg⁻¹, 75.83–179.16 mg kg⁻¹, 28.86–277.90 mg kg⁻¹, and 127.36–289.94 mg kg⁻¹, respectively. The water soluble phosphorus (WSP), readily desorbable phosphorus (RDP), algal available phosphorus (AAP), and NaHCO₃ extractable phosphorus (Olsen-P) contents in the sediments were in the ranges of 0.58–357.17 mg kg⁻¹, 80.77–586.75 mg kg⁻¹, 1.09–24.12 mg kg⁻¹, and 54.96–676.82 mg kg⁻¹, respectively. The correlation analysis results showed that the NAIP was the major component of the bioavailable P and that the impact of the AP on the bioavailable phosphorus may be minimal. Due to the low TP content in the sediments of the Quanzhou Bay Estuarine Wetland Nature Reserve, the potential pollution risks of P in the sediments may not be very high. The results also show that the bioavailable P concentrations in the sediments of the Quanzhou Bay Estuarine Wetland Nature Reserve could not be evaluated by measuring the P fractions and that the hypothesis was untenable.     

Effects of temperature on metabolic rate and lower dissolved oxygen tolerance of juvenile speckled peacock bass Cichla temensis

The speckled peacock bass Cichla temensis is a popular sport and food fish that generates substantial angling tourism and utilitarian harvest within its range. Its popularity and value make this species important for management and a potential aquaculture candidate for both fisheries enhancement and food fish production. However, little is known of optimal physiochemical conditions in natural habitats, which also are important for the development of hatchery protocols for handling, spawning and grow-out. Speckled peacock bass have been documented to have high sensitivity to extreme temperatures, but the metabolic underpinnings have not been evaluated. In this study, the effects of temperature (25, 30 and 35°C) on the standard metabolic rate (SMR) and lower dissolved oxygen tolerance (LDOT) of juvenile speckled peacock bass (mean ± standard error total length 153 ± 2 mm and wet weight 39.09 ± 1.37 g) were evaluated using intermittent respirometers after an acclimation period of 2 weeks. Speckled peacock bass had the highest SMR at 35°C (345.56 ± 19.89 mgO₂ kg⁻¹ h⁻¹), followed by 30°C (208.16 ± 12.45 mgO₂ kg⁻¹ h⁻¹) and 25°C (144.09 ± 10.43 mgO₂ kg⁻¹ h⁻¹). Correspondingly, the Q₁₀, or rate of increase in aerobic metabolic rate (MO₂) relative to 10°C, for 30–35°C was also greater (2.76) than from 25 to 30°C (2.08). Similarly, speckled peacock bass were the most sensitive to hypoxia at the warmest temperature, with an LDOT at pO₂ of 90 mmHg (4.13 mg l⁻¹) at 35°C compared to pO₂ values of 45 mmHg (2.22 mg l⁻¹) and 30 mmHg (1.61 mg l⁻¹) at 30 and 25°C, respectively. These results indicate that speckled peacock bass are sensitive to temperatures near 35°C, therefore we recommend managing and rearing this species at 25–30°C.     

Investigation of Heavy Metal Level and Mineral Nutrient Status in Widely Used Medicinal Plants’ Leaves in Turkey: Insights into Health Implications

The use of plants in treatments has been as old as humanity and it has preserved its popularity for centuries til now because of their availability, affordability and safeness. However, despite their widespread use, safety and quality issues have been major concerns in the world due to industrial- and anthropogenic-based heavy metal contamination risks. Thus, this study was attempted to analyze the heavy metal levels and mineral nutrient status of widely used medicinal plants in Turkey to have insights about their health implications on humans. The plant concentrations of B, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb and Zn were analyzed by ICP-OES in the leaves of 44 medical plants purchased from herbal markets of three different districts of Istanbul/Turkey. The measured lowest to highest concentrations were 0.065–79.749 mg kg⁻¹ B, 921.802–12,854.410 mg kg⁻¹ Ca, 0.020–0.558 mg kg⁻¹ Cd, 0.015–4.978 mg kg⁻¹ Cr, 0.042–8.489 mg kg⁻¹ Cu, 34.356–858.446 mg kg⁻¹ Fe, 791.323–15,569.349 mg kg⁻¹ K, 102.236–2837.836 mg kg⁻¹ Mg, 4.915–91.519 mg kg⁻¹ Mn, 10.224–3213.703 mg kg⁻¹ Na, 0.001–5.589 mg kg⁻¹ Ni, 0.003–3.636 mg kg⁻¹ Pb and 2.601–36.102 mg kg⁻¹ Zn. Those levels in plants were in acceptable limits though some elements in some plants have high limits which were not harmful. Variations (above acceptable limits) in element concentrations also indicated that these plants could be contaminated with other metals and that genetic variations may influence accumulation of these elements at different contents. Overall, analyzed medicinal plants are expected not to pose any serious threat to human health.

     

Effects of free and macromolecular-bound TXA2 receptor antagonist BM 1..505 on U46619-induced platelet aggregation

The goal of this study was to synthesize a macromolecular probe of the TXA₂ receptor antagonist BM13.505 which is unable to penetrate the platelet membrane for localization and characterization of the TXA₂ receptor. The active NHS-ester of BM13.505 was synthesized and purified. It was used for covalent coupling of BM13.505 to bovine serum albumin, a macromolecular carrier. Inhibitory effects of free and macromolecular bound BM13.505 on aggregatory properties of U46619-stimulated platelets were measured and compared to TXA₂ generation in platelets, as determined by TXB₂ radioimmuno assay. No inhibitory effects of free and macromolecular-bound BM13.505 on ADP- or thrombin-induced platelet aggregation were observed. Equimolar concentrations of free or macromolecular bound BM13.505 inhibited U46619-induced platelet aggregation and TXA₂ generation with equal potency. IC₅₀-values for platelet aggregation inhibition by free and macromolecular bound BM13.505 were 64 nM and 96 nM respectively. It appears that the TXA₂ receptor ligand binding site is located close to the outer membrane surface of platelets. Interaction of macromolecular bound BM13.505 with the platelet thromboxane receptor does not depend on the availability of the free carboxyl residue in BM13.505. The method for coupling a TXA₂ receptor antagonist to a macromolecule will aid in constructing probes for the localization and characterization of the TXA₂ receptor.     

Assessment of germination and carnivorous activities of a nematode-trapping fungus Arthrobotrys dactyloides in fungistatic and fungicidal soil environment

Carnivorism is the ability of nematode-trapping fungi to trap and digest the nematodes by sophisticated devices called traps. Delivery of nematode-trapping fungi in soil for bio-control of pest nematodes often fails or gives inconsistent results. Possible reasons for failure could be the effect of soil fungistasis on germination of nematode-trapping fungi in soil environment, use of avirulent species and sensitivity of these fungi to fungicidal residues in soil. Exploitation of nematode-trapping fungi for nematode control demands that it be compatible with fungicides applied in soil or crops and proliferate in soil. This investigation represents is one of the first to evaluate the effect of fungicides on the nematode-trapping fungus Arthrobotrys dactyloides. A. dactyloides showed in vitro carnivorous potential against Meloidogyne incognita, Meloidogyne javanica, Meloidogyne graminicola, Helicotylenchus dihystera and Heterodera cajani. Conidia of A. dactyloides exposed to agricultural soils showed poor germination but formed conidial traps, which captured and killed the soil nematodes. Conidial traps, which trapped the nematodes, grew well in all soils after killing and nutrient absorption from nematode body. Soil amended with 20 mg ai kg⁻¹ of carbendazim and thiram, 30 mg ai kg⁻¹ of mancozeb, 50 mg ai kg⁻¹ of captan, and 100 mg ai kg⁻¹ of carboxin completely checked the conidial trap formation and nematode capturing. 30, 50 and 100 mg ai kg⁻¹ of metalaxyl adversely affected the conidial trap formation and nematode capturing in soil. Propiconazole inhibited 15.2% conidial trap formation up to 50 mg ai kg⁻¹ but caused 93.3% inhibition of conidial traps formation and complete inhibition of nematode capturing at 100 mg ai kg⁻¹. Sulphur, triademefon, and tricyclazole showed least toxic effect on conidial trap formation and nematode capturing activities of A. dactyloides in soil up to 100 mg ai kg⁻¹.     

Estimation of the phosphorus requirement of weanling pigs fed supplemental phytase

Studies were conducted with crossbred weanling pigs to determine the level of phosphorus needed to be fed when a maize–soyabean meal–whey diet was supplemented with exogenous phytase (Natuphos™). In Trial 1, phytase was added at 1200 phytase units (PTU) kg⁻¹ as phosphorus decreased. The control diet in Phase I (0–14 days) contained 7.3 g kg⁻¹ phosphorus and in Phase II (14–28 days) contained 6.5 g kg⁻¹ phosphorus. Dietary phosphorus was calculated to decrease by 0.8, 1.6 or 2.4 g kg⁻¹ when phytase was supplemented. Chromic oxide was added for estimation of apparent absorption of phosphorus. Performance was optimum when 5.7 and 4.8 g kg⁻¹ phosphorus (analysed levels) were fed with 1200 PTU kg⁻¹ phytase in Phases I and II, respectively. The lowest dietary phosphorus levels did not reduce performance for the overall 28-day period. Apparent phosphorus digestibility was increased by phytase in Phase I when 5.7 g kg⁻¹ phosphorus was fed compared to the control diet and in Phase II when 6.0 g kg⁻¹ phosphorus was fed with phytase. Faecal phosphorus excretion decreased in both phases as dietary phosphorus decreased. Faecal phosphorus excretion was minimized at the lowest phosphorus level with no decrease in performance. The estimated requirement for dietary phosphorus, as determined by the NLIN procedure, is 5.0 g kg⁻¹ in Phase I and 4.3 g kg⁻¹ in Phase II when 1200 PTU kg⁻¹ is used. In Trial 2, phytase was supplemented at 500 PTU kg⁻¹ when phosphorus was decreased in the diet. The control diet contained 6.6 and 6.0 g kg⁻¹ phosphorus in Phases I and II, respectively, and phosphorus was calculated to decrease by 0.5, 1.0, 1.5, or 2.0 g kg⁻¹ when phytase was added. Daily gain decreased when 5.0 g kg⁻¹ phosphorus was fed in Phase I and when 4.6 or 4.2 g kg⁻¹ (analysed levels) phosphorus was fed in Phase II with 500 PTU kg⁻¹. Faecal phosphorus excretion decreased as dietary phosphorus decreased, but there were no treatment effects on apparent phosphorus digestibility. The dietary phosphorus requirement was estimated to be 5.7 and 5.0 g kg⁻¹ in Phases I and II, respectively, when phytase is fed at 500 PTU kg⁻¹. At the present recommendation of 500 PTU kg⁻¹ in starter feed, phosphorus can be decreased by 0.10 g kg⁻¹. However, higher levels of phytase are needed to actually increase apparent phosphorus digestibility.     

Soil nitrate accumulation explains the nonlinear responses of soil CO2 and CH4 fluxes to nitrogen addition in a temperate needle-broadleaved mixed forest

The responses of soil-atmosphere carbon (C) exchange fluxes to growing atmospheric nitrogen (N) deposition are controversial, leading to large uncertainty in the estimated C sink of global forest ecosystems experiencing substantial N inputs. However, it is challenging to quantify critical load of N input for the alteration of the soil C fluxes, and what factors controlled the changes in soil CO₂ and CH₄ fluxes under N enrichment. Nine levels of urea addition experiment (0, 10, 20, 40, 60, 80, 100, 120, 140 kg N ha⁻¹ yr⁻¹) were conducted in the needle-broadleaved mixed forest in Changbai Mountain, Northeast China. Soil CO₂ and CH₄ fluxes were monitored weekly using the static chamber and gas chromatograph technique. Environmental variables (soil temperature and moisture in the 0–10 cm depth) and dissolved N (NH₄⁺-N, NO₃⁻-N, total dissolved N (TDN), and dissolved organic N (DON)) in the organic layer and the 0–10 cm mineral soil layer were simultaneously measured. High rates of N addition (≥60 kg N ha⁻¹ yr⁻¹) significantly increased soil NO₃⁻-N contents in the organic layer and the mineral layer by 120%-180% and 56.4%-84.6%, respectively. However, N application did not lead to a significant accumulation of soil NH₄⁺-N contents in the two soil layers except for a few treatments. N addition at a low rate of 10 kg N ha⁻¹ yr⁻¹ significantly stimulated, whereas high rate of N addition (140 kg N ha⁻¹ yr⁻¹) significantly inhibited soil CO₂ emission and CH₄ uptake. Significant negative relationships were observed between changes in soil CO₂ emission and CH₄ uptake and changes in soil NO₃⁻-N and moisture contents under N enrichment. These results suggest that soil nitrification and NO₃⁻-N accumulation could be important regulators of soil CO₂ emission and CH₄ uptake in the temperate needle-broadleaved mixed forest. The nonlinear responses to exogenous N inputs and the critical level of N in terms of soil C fluxes should be considered in the ecological process models and ecosystem management.     

Responsiveness of Carob (Ceratonia siliqua L.) Plants to Arbuscular Mycorrhizal Symbiosis Under Different Phosphate Fertilization Levels

This experiment was carried out in pots in a greenhouse to evaluate the effects of arbuscular mycorrhizal fungi (Funneliformis mosseae, Rhizophagus intraradices and Rhizophagus fasciculatus) on carob plant performance under different levels of phosphate fertilization. Non-mycorrhizal (NMyc) and mycorrhizal (Myc) carob plants were subjected to three levels of phosphate fertilization, L1 (0 mg P kg⁻¹ soil), L2 (25 mg P kg⁻¹ soil) and L3 (100 mg P kg⁻¹ soil). Results showed that under L1 and L2 P-fertilization levels, arbuscular mycorrhizal symbiosis significantly improved growth and biomass production of carob plants. Moreover, mineral nutrient (P, K, Na and Ca) acquisition, photosynthetic activity (F_v/F_m), stomatal conductance, total chlorophyll content, and soluble sugar accumulation were also strongly improved in Myc plants in comparison with NMyc ones. Under L1 P-fertilization level, Myc plants showed strongly increased acid phosphatase activity in roots and in the rhizospheric soil than NMyc plants. Furthermore, Myc plants maintained high membrane integrity (over 80%) and low hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) contents, associated with increased activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), guaiacol peroxidase (G-POD), and catalase (CAT) compared to NMyc plants. However, high phosphorus input (L3) negatively affected root colonization and mycorrhizal plant performance. Thus, carob plants associated with Funneliformis mosseae performed best under phosphorus deficiency and were the least sensitive to the variations of phosphorus input levels.

     

Synergistic effect of Se-methylselenocysteine and vitamin E in ameliorating the acute ethanol-induced oxidative damage in rat

The present study was conduced to investigate the synergistic effects of combined treatments with Se-methylselenocysteine (SeMSC) and vitamin E (Vit E) in reversing oxidative stress induced by ethanol in serum and different tissues of rats. Sixty female rats were randomly divided into six groups for 30 days’ consecutive pretreatments as followed: control (I), physiological saline (II), 2.8 μg kg⁻¹ Se as SeMSC (III), 2.8 μg kg⁻¹ Se as sodium selenite (Na₂SeO₃, IV), 5 mg kg⁻¹ α-tocopherol as α-tocopherol acetate (Vit E, V), 5 mg kg⁻¹ α-tocopherol as α-tocopherol acetate and 2.8 μg kg⁻¹ Se as SeMSC (VI). All animals in groups II–VI were treated by ethanol treatment to cause oxidative stress. After 6 h of ethanol treatment, the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), the contents of total antioxidant capacity (T-AOC), malondialdehyde (MDA), glutathione (GSH) and carbonyl protein (CP) in the serum, liver, heart and kidney were measured. The result showed that the individual SeSMC, Na₂SeO₃ and vitamin E could effectively increase the SOD, T-AOC, GSH-Px and GSH contents as well as significantly decrease the MDA and CP concentrations in the tissues of ethanol-induced rats. At the same dose on different forms of Se, SeMSC showed greater antioxidant activity than Na₂SeO₃. Moreover, group VI (SeMSC and α-tocopherol acetate) showed much better antioxidant activity than individual group III (SeMSC) and V (α-tocopherol acetate) due to the synergistic effect.     

Comparative Effects of Superoxide Anion and Hydrogen Peroxide on Microsomal and Cytosolic Glutathione <Emphasis Type="Italic">S</Emphasis>-Transferase Activities of Rat Liver

Three hundred sixty healthy Ross×Ross 1-day-old broilers were used to study the effects of zinc glycine chelate (Zn-Gly) on growth performance, hematological, and immunological characteristics. All broilers were randomly assigned into six treatments. Diets were as follows: (1) control (containing 29.3 mg Zn kg⁻¹ basic diet [0–3 weeks] and 27.8 mg Zn kg⁻¹ [4–6 weeks]); (2) basic diet plus 30 mg Zn kg⁻¹ from Zn-Gly; (3) basic diet plus 60 mg Zn kg⁻¹ from Zn-Gly; (4) basic diet plus 90 mg Zn kg⁻¹ from Zn-Gly; (5) basic diet plus 120 mg Zn kg⁻¹ from Zn-Gly; (6) positive control, basic diet plus 120 mg Zn kg⁻¹ from zinc sulfate (ZnSO₄). After the 21- and 42-day feeding trials, the results showed that both of Zn-Gly and ZnSO₄ could improve the growth performance of broilers, with the greatest average daily feed intake observed in the broilers fed 90 mg Zn kg⁻¹ from Zn-Gly, but the greatest average daily gain observed with 120 mg Zn kg⁻¹ from Zn-Gly (0–3 weeks) and 90 mg Zn kg⁻¹ from Zn-Gly (4–6 weeks). Adding additional Zn-Gly improved the levels of immunoglobulins (IgA, IgM, and IgG) and the contents of total protein and Ca in serum and increased the immune organs index especially with 90 mg Zn kg⁻¹ as Zn-Gly. However, there were no significant differences in responses to complements (C3 and C4) and albumin in serum among the treatments.     

Combined and Singular Effects of Dietary PrimaLac® and Potassium Diformate (KDF) on Growth Performance and Some Physiological Parameters of Rainbow Trout (Oncorhynchus mykiss)

The present study was conducted to assess the effects of combined and singular dietary administration of PrimaLac® and potassium diformate (KDF) on growth performance, feed utilization, digestive enzymes activity, and some physiological parameters of rainbow trout (Oncorhynchus mykiss) juvenile. Three hundred sixty rainbow trout juveniles (25 ± 1.8 g) were randomly stocked in 300-L tanks (30 fish/tank), and fed three times daily on a basal diet (control), diets incorporated with 12 g kg⁻¹ KDF (FT₁), 1.5 g kg⁻¹ PrimaLac® (FT₂), and combination of 1.5 g kg⁻¹ probiotic and 12 g kg⁻¹ KDF (FT₃) in triplicates, for 8 weeks. At the end of feeding trial, growth performance, body composition, digestive enzymes, liver enzymes, and biochemical parameters were measured. Our results revealed that combined administration of PrimaLac® and KDF (FT₃) exhibited significantly higher weight gain and specific growth rate (SGR) compared to other groups (P < 0.05). Glucose and cortisol levels showed no significant differences between fish fed different test diets (P > 0.05). The highest lipase, protease and amylase activity were observed in group of fish fed FT₃ followed by FT₂ and FT₁. Besides, the diets FT₂ and FT₃ led to significantly lower of ALP, ALT, and AST compared to control group. The present results indicated that combined administration of PrimaLac® and KDF can be considered as a beneficial feed additive and growth promotor for O. mykiss juvenile.