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1.

Background

Sports Dietitians aim to assist in improving performance by developing nutrition knowledge (NK), enhancing dietary intake and optimising body composition of athletes. In a high-pressure environment, it is important to identify factors that may compromise an athlete’s nutrition status. Body composition assessments are regularly undertaken in sport to provide feedback on training adaptions; however, no research has explored the impact of these assessments on the dietary intake of professional athletes.

Methods

This cross-sectional study assessed dietary intake (7-day food diary), nutrition knowledge (Nutrition for Sport Knowledge Questionnaire) and body composition (Dual-energy X-ray absorptiometry) of 46 professional male Australian football (AFL) athletes during a 2017 pre-season training week (7 days) where body composition assessments were undertaken. Dietary intake was assessed against International Olympic Committee recommendations for professional athletes.

Results

Overall, no athlete met dietary their recommended energy intake (15?±?1.1 vs. 9.1?±?1.8 MJ, respectively) or carbohydrate recommendations (6–10 vs. 2.4?±?0.9 g·kg-1·day-1). Only 54% met protein recommendations. Secondary analyses demonstrated significant associations between education status and energy intake (P <?0.04) and vegetable intake (P <?0.03), with higher levels of education being associated with higher intakes. A moderately positive association was observed between NK scores and meeting estimated energy requirements (r =?0.33, P =?0.03). NK scores were also positively associated with protein (r =?0.35, P =?0.02), fibre (r =?0.51, P =?0.001) and calcium intakes (r =?0.43, P =?0.004).

Conclusions

This research identified that the dietary intake of professional AFL athletes during a pre-season training week where body composition assessments were undertaken did not meet current recommendations. Several factors may influence the dietary intake of AFL athletes, including lower education levels, poor NK and dietary intake restriction surrounding body composition assessment. Athletes may require support to continue with performance-based nutrition plans in periods surrounding body composition assessment.
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2.
Blood lipids are associated with cardiovascular disease (CVD) risk. Moreover, circulating lipid and fatty acid levels vary between men and women, and evidence demonstrates these traits may be influenced by single nucleotide polymorphisms (SNP). Sex-genotype interactions related to blood lipids and fatty acids have been poorly investigated and may help elucidate sex differences in CVD risk. The goal of this study was to investigate if the influence of SNPs previously associated with blood lipids and fatty acids varies in a sex-specific manner. Lipids and fatty acids were measured in serum and red blood cells (RBC), respectively, in 94 adults (18–30 years) from the GONE FISHIN’ cohort and 118 age-matched individuals from the GOLDN cohort. HDL-c levels were higher and the total cholesterol/HDL-c (TC/HDL-c) ratio was lower in women versus men (p < 0.01). RBC palmitoleic acid and the stearoyl-CoA desaturase index were both higher in women (p < 0.01). Fatty acid desaturase (FADS) pathway activity (estimated using the ratio of eicosapentaenoic acid/alpha-linolenic acid) was higher in men (p < 0.01). The AA genotype for rs1800775 in CETP had a lower TC/HDL-c ratio in men, but not women (p int = 0.03). Independent of sex, major alleles for rs174537 in FADS1 (GG) and rs3211956 in CD36 (TT) had higher arachidonic acid, lower dihomo-γ-linoleic acid, and a higher FADS1 activity compared to minor alleles. The current study showed that blood lipid and fatty acid levels vary between healthy young men and women, but that the observed sex differences are not associated with common variants in candidate lipid metabolism genes.  相似文献   

3.
Medium chain fatty acid (MCFA) escapes the formation of chylomicrons in the small intestine, resulting in energy expenditure through beta-oxidation. Diacylglycerol (DAG) is susceptible to oxidation rather than being stored in the adipose tissue. This study was conducted to verify the effect of MCE-DAG oil on body fat mass in vivo. Male C57BL/6 mice were randomly assigned to four groups (n = 12) as follows: (1) normal diet (18% kcal from fat), (2) canola oil as a control (40% kcal from canola oil), (3) MCE-DAG10 (10% kcal from MCE-DAG + 30% kcal from canola oil), and (4) MCE-DAG20 (20% kcal from MCE-DAG + 20% kcal from canola oil). The body weight and fat mass of MCE-DAG20 group mice were decreased relative to those of control mice (P < 0.05 and P < 0.001, respectively). Serum triacylglycerol (TAG) was decreased in both MCE-DAG10 and MCE-DAG20 groups (P < 0.01 and P < 0.05, respectively). Hormone sensitive lipase (HSL) and adipose triglyceride lipase (ATGL) were increased in the MCE-DAG20 group relative to the control in white adipose tissue (WAT) (P < 0.05). Uncoupling protein 1 (UCP1) was also increased in the MCE-DAG20 group relative to the control in brown adipose tissue (BAT) (P < 0.05). In summary, MCE-DAG reduced body fat mass likely by stimulating lipolysis in WAT and thermogenesis in BAT.  相似文献   

4.
The present study was designed to determine if feeding steers extruded flaxseed and hay (25 and 75%; DM basis) together as a total mixed ration (TMR), or sequentially (non-TMR) would result in different enrichments of polyunsaturated fatty acids (PUFA) and their biohydrogenation intermediates (BHI) in beef adipose tissues [subcutaneous (SC) vs perirenal (PR) fat]. Forty-eight Angus cross steers (325 ± 16 kg) were stratified by weight to six pens, and pens were randomized to either TMR or non-TMR and fed ad libitum for an average of 242 days. The concentrations of α-linolenic acid increased by 18 mol% in both SC and PR in non-TMR steers compared to TMR steers (P < 0.01). trans 18:1 isomers were more concentrated in PR than SC (14.4 vs 9.5 mol%; P < 0.01) and increased by 10 mol% in both fat depots for non-TMR (P < 0.01). Other BHI including non-methylene-interrupted 18:2 (atypical dienes), conjugated linoleic acids and conjugated linolenic acids (CLnA) were affected by diet × tissue interactions (P < 0.01). The CLnA and CLA contents were higher in both fat depots when feeding the non-TMR, but the effect of diet was more pronounced in PR than in SC (P < 0.01). Atypical dienes were highest in PR from non-TMR and lowest in TMR fed steers (4.3 and 3.6 mol%) with SC contents being intermediate. The sequential feeding of lipid supplement can thus profoundly affect the enrichment of PUFA and their BHI in beef fat and their differentially enrichment is also fat depot dependant.  相似文献   

5.

Background

Whole grain (WG) intake is associated with reduced risk of obesity, type 2 diabetes and cardiovascular disease, whereas type 2 diabetes increases the risk of cognitive decline and dementia. The purpose of this study was to investigate the effects of short-term intervention with WG rye on cognitive functions, mood and cardiometabolic risk markers in middle-aged test subjects.

Method

Rye-based breads were provided to 38 healthy test subjects (aged 52-70y) during three consecutive days in a crossover study design, using white wheat flour bread (WWB) as a reference. The rye-based bread consisted of a WG rye kernel/flour mixture (1:1 ratio) supplemented with resistant starch type 2 (RS2) (RB?+?RS2). The last bread portion was ingested at 2100 h, and cognitive function, mood and cardiometabolic risk markers were determined the following morning, 11???14 h post intake.

Results

In comparison to WWB, the RB?+?RS2 product increased ratings of mood parameters (valance, P?<?0.001; activation P?<?0.05). No differences were seen in the cognitive tests depending on intervention (P?>?0.05). RB?+?RS2 increased insulin sensitivity (P?<?0.05), fasting levels of gut hormones (PYY, P?<?0.05; GLP-2, P?<?0.01) and fasting concentrations of plasma acetate, butyrate and total SCFA (P?<?0.001). In contrast, fasting levels of IL???1β were decreased (P?<?0.05). Insulin sensitivity was positively correlated with working memory test performance (P?<?0.05).

Conclusions

This study display novel findings regarding effects of WG rye products on mood, and glucose and appetite regulation in middle-aged subjects, indicating anti-diabetic properties of WG rye. The beneficial effects are suggested to be mediated through gut fermentation of dietary fiber in the RB?+?RS2 product.

Trial registration

The study was retrospectively registered at ClinicalTrials.gov, register number NCT03275948. Registered September 8 2017.
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6.
Nutrients and plant secondary compounds in aspen (Populus tremuloides) may interact with nutrients in the surrounding vegetation to influence aspen use by herbivores. Thus, this study aimed to determine aspen intake and preference by sheep in response to supplementary nutrients or plant secondary compounds (PSC) present in aspen trees. Thirty-two lambs were randomly assigned to one of four molasses-based supplementary feeds to a basal diet of tall fescue hay (N = 8) during three experiments. The supplements were as follows: (1) high-protein (60% canola meal), (2) a PSC (6% quebracho tannins), (3) 25% aspen bark, and (4) control (100% molasses). Supplements were fed from 0700 to 0900, then lambs were fed fresh aspen leaves collected from stands containing high (Experiment 1, 2) or low (Experiment 3) concentrations of phenolic glycosides (PG). In Experiment 2, lambs were simultaneously offered aspen, a forb (Lathyrus pauciflorus), and a grass (Bromus inermis) collected from the aspen understory. Animals supplemented with high protein or tannins showed greater intake of aspen leaves than animals supplemented with bark or the control diet (P < 0.05), likely because some condensed tannins have a positive effect on protein nutrition and protein aids in PSC detoxification. Overall, animals supplemented with bark showed the lowest aspen intake, suggesting PSC in bark and aspen leaves had additive inhibitory effects on intake. In summary, these results suggest that not only the concentration but also the types and proportions of nutrients and chemical defenses available in the plant community influence aspen use by herbivores.  相似文献   

7.
8.
Phenolics, volatiles, squalene, tocopherols, and fatty acids of virgin olive oils (VOO) from adult and young olive trees of the Oueslati variety, typically cultivated in the Center of Tunisia, were analyzed at three different harvesting periods. Significant differences in contents of saturated fatty acids (p < 0.05), squalene (p < 0.05), alpha-tocopherol and total tocopherol (p < 0.02) and oxidized form of decarboxymethyl oleuropein aglycon (p < 0.05) were seen between VOO from adult and young trees during maturation. Moreover, the volatile profiles of VOO from adult and young trees showed significant differences in the amounts of hexanal, 1-penten-3-ol (p < 0.05), (Z)-3-hexenal and (Z)-2-penten-1-ol (p < 0.01). Principal component analysis showed that olives from adult trees should be harvested at the cherry stage of maturation to obtain a satisfactory level of oil quality, while olives from young trees should be harvested at the black maturation stage.  相似文献   

9.

Background

This study aimed to evaluate the concordance between two dietary indexes, the Healthy Eating Index (HEI) and the Diabetes Healthy Eating Index (DHEI), in evaluating diet quality and its possible association with therapeutic targets in patients with type 2 diabetes.

Methods

Cross-sectional study of outpatients with type 2 diabetes mellitus treated at a university hospital. Dietary information was obtained from a quantitative food frequency questionnaire (previously validated for use in patients with type 2 diabetes) and converted into daily intakes. Diet quality was assessed using two dietary indexes: HEI (12 components, nine food groups and three moderation components) and DHEI (10 components, six food groups, three nutrient groups, and one for variety of diet). In both indexes, the sum of the scores for each component yields an overall score converted on a scale from 0 to 100%; diet quality is subsequently ranked as low (<51%), needing improvement (51–80%), or high (>80%). Patients underwent clinical and laboratory assessment. Those with fasting blood glucose values 70–130 mg/dL, A1c?<?7%, total cholesterol <200 mg/dL, LDL-cholesterol <100 mg/dL, and triglycerides <150 mg/dL were considered to meet therapeutic targets. All analyses were conducted in PASW Statistics 18.0, and p?<?0.05 deemed significant.

Results

We analyzed 148 patients with type 2 diabetes (73% white, mean age 63.2?±?9.4 years, median diabetes duration 10 [IQR 5–19] years, mean A1c% 8.4?±?2.0%, and mean BMI 30.5?±?4.2 kg/m2). Mean energy intake was 2114?±?649 kcal/day. DHEI scores were 17.0 (95%CI -6.8 to 41.0) points lower than HEI scores (55.9?±?14.2% vs. 72.9?±?10.7%, respectively; P?<?0.001), suggesting there is no agreement (Bland-Altman method), and the Pearson correlation coefficient was 0.55 (P?<?0.001). More patients were classified as having a low-quality diet by the DHEI than by the HEI (38.5% vs. 1.4%; P?<?0.001). A higher proportion of patients (35.7%) with out-of-target total cholesterol levels had a low-quality diet evaluated by the DHEI (P?=?0.03). We did not find associations between overall score of HEI and therapeutic targets.

Conclusions

In its intended population of patients with type 2 diabetes, the DHEI seems to be a more rigorous tool to evaluate association between diet quality and changes in metabolic parameters.
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10.

Background

A proprietary composition GMCT contains extracts of two popular Asian herbs viz., Garcinia mangostana (GM) fruit rind and Cinnamomum tamala (CT) leaf. We systematically evaluated physical performance and muscle strength enhancing ability of GMCT in a preclinical mouse model followed by a 42-days double-blind placebo controlled human trial in resistance trained adult males.

Methods

Four groups of Swiss albino mice (20–30 g body weight) (n?=?6) were fed a standard laboratory diet and given Carboxymethylcellulose sodium (CMC), 150 mg/kg GMCT (GMCT-150), 300 mg/kg GMCT (GMCT-300) or 50 mg/kg Oxymetholone (OXY) via oral gavage for 21 days. On day 22, the animals’ physical performance and muscle strength were assessed in a forced swimming test (FST) and forelimb grip strength experiment, respectively.In the human trial, thirty-eight resistance-trained young adults (mean age 26.32?±?4.39 years, body weight 67.79?±?12.84 kg, BMI 22.92?±?3.54 kg/m2) completed the trial. The participants received either GMCT (n?=?19; 800 mg daily) or matched placebo (n?=?19) for 42 days. As primary variables, 1-RM bench press, 1-RM leg press, and leg extension repetitions were measured at baseline and on days 14, 28 and 42 of the intervention. Anthropometric parameters and serum markers such as free testosterone, insulin-like growth factor 1 (IGF-1), insulin and lactate were also measured before and after the intervention.

Results

GMCT-300 mice showed significant improvement in swimming time (GMCT: 395.3?±?81.70 s vs. CMC: 271.6?±?56.86 s; p?=?0.0166), distance (GMCT: 341.22?±?65.88 m vs. CMC: 260.84?±?49.15 m; p?=?0.0461) and grip strength (GMCT: 43.92?±?6.97 N vs. CMC: 35.0?±?6.92 N; p?=?0.0490), compared with the CMC group.At the end of the 42-day human trial, the per protocol analyses reveal that mean changes from baseline 1-RM bench press (GMCT: 23.47?±?10.07 kg vs. PL: 3.42?±?2.06 kg; p?<?0.0001), leg press (GMCT: 29.32?±?16.17 kg vs. PL: 5.21?±?1.72 kg; p?<?0.0001), number of leg extension repetitions (GMCT: 6.58?±?2.57 vs. PL: 2.05?±?1.22; p?<?0.0001) in GMCT group were significantly improved, compared with placebo. Intergroup difference analyses show that the changes from baseline left arm (GMCT: 1.09?±?0.36 cm vs. PL: 0.68?±?0.42 cm; p?=?0.0023), right arm (GMCT: 1.50?±?0.44 cm vs. PL: 1.11?±?0.43 cm; p?=?0.0088) circumference and lean mass (GMCT: 2.29?±?2.09 kg vs. PL: 0.52?±?2.58 kg; p?=?0.0404) in GMCT group were also significantly improved, compared with placebo. In comparison to placebo, GMCT supplementation did not improve free testosterone, IGF-1, insulin or lactate levels. Parameters of clinical biochemistry, hematology, urine and vital signs of the participants were within the normal range.

Conclusion

GMCT supplementation is effective in increasing muscle strength, muscle size and, total lean mass, as well as endurance performance.Trial Registration.Clinical Trial Registry of India (CTRI/2015/01/005374), Registered on Jan 07, 2015; CTRI Website URL - http://ctri.nic.in
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11.
Drug-resistant strains of Helicobacter pylori and poor treatment response are the main reasons for the failure in eradicating it in patients. Polyunsaturated fatty acids (PUFA) have an inhibitory effect on bacterial growth. The aim of this study was to investigate the effect of PUFA in combination with standard triple therapy on apoptosis in H. pylori infected subjects with dyspeptic symptoms. This study was a double-blind clinical trial in which 34 H. pylori infected subjects with dyspeptic symptoms were randomly divided into two groups of 17 patients. The control group received standard triple therapy (amoxicillin, clarithromycin and omeprazole) and the experimental group received the standard therapy and PUFA for two weeks. Gene expression levels of caspase-3, BCL-2 and Bad proteins were studied with real-time PCR, while protein levels were quantified in frozen sections and using immunohistochemistry. Compared with the control group, a significant increase (p < 0.01) was observed in the expression of caspase-3 and Bad genes and a significant reduction (p < 0.05) in the expression of Bcl-2 gene. The protein level of active caspase-3 and Bad protein was significantly increased and the level of Bcl-2 protein was significantly decreased (p < 0.05). The results of this study show that oral administration of PUFA in combination with the standard triple therapy increased apoptosis in H. pylori-infected patients with dyspeptic symptoms. This increase in apoptosis may partly reduce drug resistance in these patients. Our results suggest inclusion of a dietary PUFA containing fatty acid supplement may improve treatment of patients that are refractory to the standard triple therapy.  相似文献   

12.
The potential cause–effect relationship between uric acid plasma concentrations and HDL functionality remains elusive. Therefore, this study aimed to explore the effect of oxonic acid (OA)-induced hyperuricemia on the HDL size distribution, lipid content of HDL subclasses, and apo AI turnover, as well as HDL functionality in New Zealand white rabbits. Experimental animals received OA 750 mg/kg/day by oral gavage during 21 days. The HDL-apo AI fractional catabolic rate (FCR) was determined by exogenous labeling with 125I, and HDL subclasses were determined by sequential ultracentrifugation and PAGE. Paraoxonase-1 activity (PON-1) and the effect of HDL on relaxation of aorta rings in vitro were determined as an indication of HDL functionality. Oxonic acid induced a sixfold increase of uricemia (0.84 ± 0.06 vs. 5.24 ± 0.12 mg/dL, P < 0.001), and significant decreases of triglycerides and phospholipids of HDL subclasses, whereas HDL size distribution and HDL-cholesterol remained unchanged. In addition, HDL-apo AI FCR was significantly higher in hyperuricemic rabbits than in the control group (0.03697 ± 0.0038 vs. 0.02605 ± 0.0017 h?1 respectively, P < 0.05). Such structural and metabolic changes were associated with lower levels of PON-1 activities and deleterious effects of HDL particles on endothelium-mediated vasodilation. In conclusion, hyperuricemia is associated with structural and metabolic modifications of HDL that result in impaired functionality of these lipoproteins. Our data strongly suggest that uric acid per se exerts deleterious effects on HDL that contribute to increase the risk of atherosclerosis.  相似文献   

13.

Background

Inadequate protein intake (PI), containing a sub-optimal source of essential amino acids (EAAs), and reduced appetite are contributing factors to age-related sarcopenia. The satiating effects of dietary protein per se may negatively affect energy intake (EI), thus there is a need to explore alternative strategies to facilitate PI without compromising appetite and subsequent EI.

Methods

Older women completed two experiments (EXP1 and EXP2) where they consumed either a Bar (565 kJ), a Gel (477 kJ), both rich in EAAs (7.5 g, 40% L-leucine), or nothing (Control). In EXP1, participants (n?=?10, 68?±?5 years, mean?±?SD) consumed Bar, Gel or Control with appetite sensations and appetite-related hormonal responses monitored for one hour, followed by consumption of an ad libitum breakfast (ALB). In EXP2, participants (n?=?11, 69?±?5 years) ingested Bar, Gel or Control alongside an ALB.

Results

In EXP1, EI at ALB was not different (P?=?0.674) between conditions (1179?±?566, 1254?±?511, 1206?±?550 kJ for the Control, Bar, and Gel respectively). However, total EI was significantly higher in the Bar and Gel compared to the Control after accounting for the energy content of the supplements (P?<?0.0005). Analysis revealed significantly higher appetite Area under the Curve (AUC) (P?<?0.007), a tendency for higher acylated ghrelin AUC (P?=?0.087), and significantly lower pancreatic polypeptide AUC (P?=?0.02) in the Control compared with the Bar and Gel. In EXP2, EI at ALB was significantly higher (P?=?0.028) in the Control (1282?±?513 kJ) compared to the Bar (1026?±?565 kJ) and Gel (1064?±?495 kJ). However, total EI was significantly higher in the Bar and Gel after accounting for the energy content of the supplements (P?<?0.007).

Conclusions

Supplementation with either the Bar or Gel increased total energy intake whether consumed one hour before or during breakfast. This may represent an effective nutritional means for addressing protein and total energy deficiencies in older women.

Trial registration

Clinical trial register: retrospectively registered, ISRCTN12977929 on.
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14.
We hypothesized that low molecular weight urinary proteins play a role in male-male chemical communication in the water vole, Arvicola ampibius L. We studied the effect of placing soiled litter from strange males into the cage of another sexually mature male on the intensity of its digging and scattering, urination on the litter, and alteration in the levels of low molecular weight proteins (15–25 kDa) excreted in the urine before and after 4 days of exposure as determined by chip electrophoresis. The intensity of digging and scattering was positively correlated with levels of testosterone in serum of males exposed to strange male odors (r = 0.56; P < 0.01), as well as with the concentration of low molecular weight proteins in the donor’s urine (r = 0.52, P < 0.05). At the end of the experiment, the level of low molecular weight protein in excreted urine was elevated in the males exposed to the strange male’s litter. These results highlight the importance of quantitative inter-individual variation of low molecular weight urinary proteins in the modulation of the physiology and behavior of conspecifics.  相似文献   

15.
Barth syndrome (BTHS) is an X-linked genetic disease resulting in loss of cardiolipin (Ptd2Gro). Patients may be predisposed to hypoglycemia and exhibit increases in whole-body glucose disposal rates and a higher fat mass percentage. We examined the reasons for this in BTHS lymphoblasts. BTHS lymphoblasts exhibited a 60% increase (p < 0.004) in 2-[1,2-3H(N)]deoxy-d-glucose uptake, a 40% increase (p < 0.01) in glucose transporter-3 protein expression, an increase in phosphorylated-adenosine monophosphate kinase (AMPK) and a 58% increase (p < 0.001) in the phosphorylated-AMPK/AMPK ratio compared to controls. In addition, BTHS lymphoblasts exhibited a 90% (p < 0.001) increase in d-[U-14C]glucose incorporated into 1,2,3-triacyl-sn-glycerol (TAG) and a 29% increase (p < 0.025) in 1,2-diacyl-sn-glycerol acyltransferase-2 activity compared to controls. Thus, BTHS lymphoblasts exhibit increased glucose transport and increased glucose utilization for TAG synthesis. These results may, in part, explain why BTHS patients exhibit an increase in whole-body glucose disposal rates, may be predisposed to hypoglycemia and exhibit a higher fat mass percentage.  相似文献   

16.
The purpose of this study was to determine the levels of trans-octadecenoic acid (C18:1-trans) and trans-isomers of linoleic acid (18:2-trans), as well as long-chain polyunsaturated fatty acids (LC-PUFA), in the plasma from infants of adolescent mothers at 3 months of age, exclusively breastfed, and the relationship with the levels of the same isomers in plasma and milk of the mothers. Samples of blood and mature milk were obtained from 49 healthy adolescent mothers and their exclusively breastfed infants treated at the Instituto Fernandes Figueira-Fundação Oswaldo Cruz (IFF-FIOCRUZ) in Rio de Janeiro, Brazil. trans-Fatty acids (TFA) were analyzed by gas chromatography. The results of this study showed low levels of TFA in milk (1.53%), maternal plasma (0.50%), and plasma of infants (0.74%). The results show that, although TFA have been found in the plasma of the studied infants, the LC-PUFA levels are kept within normal limits. No association between TFA presence and parameters of nutritional status of the infants was observed, probably due to the low levels of these fatty acids found in this study.  相似文献   

17.
Maize, a genetically diverse crop, is the domesticated descendent of its wild ancestor, teosinte. Recently, we have shown that certain maize landraces possess a valuable indirect defense trait not present in commercial hybrids. Plants of these landraces release herbivore-induced plant volatiles (HIPVs) that attract both egg [Trichogramma bournieri Pintureau & Babault (Hymenoptera: Trichogrammatidae)] and larval [Cotesia sesamiae Cameron (Hymenoptera: Braconidae)] parasitoids in response to stemborer egg deposition. In this study, we tested whether this trait also exists in the germplasm of wild Zea species. Headspace samples were collected from plants exposed to egg deposition by Chilo partellus Swinhoe (Lepidoptera: Crambidae) moths and unexposed control plants. Four-arm olfactometer bioassays with parasitic wasps, T. bournieri and C. sesamiae, indicated that both egg and larval parasitoids preferred HIPVs from plants with eggs in four of the five teosinte species sampled. Headspace samples from oviposited plants released higher amounts of EAG-active compounds such as (E)-4,8-dimethyl-1,3,7-nonatriene. In oviposition choice bioassays, plants without eggs were significantly preferred for subsequent oviposition by moths compared to plants with prior oviposition. These results suggest that this induced indirect defence trait is not limited to landraces but occurs in wild Zea species and appears to be an ancestral trait. Hence, these species possess a valuable trait that could be introgressed into domesticated maize lines to provide indirect defense mechanisms against stemborers.  相似文献   

18.
A series of well-defined novel amphiphilic temperature-responsive graft copolymers containing PCL analogues P(αClεCL-co-εCL) as the hydrophobic backbone, and the hydrophilic side-chain PEG analogues P(MEO2MA-co-OEGMA), designated as P(αClεCL-co-εCL)-g-P(MEO2MA-co-OEGMA) have been prepared via a combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). The composition and structure of these copolymers were characterized by 1H NMR and GPC analyses. The self-assembly behaviors of these amphiphilic graft copolymers were investigated by UV transmittance, a fluorescence probe method, dynamic light scattering (DLS) and transmission electron microscopy (TEM) analyses. The results showed that the graft copolymers exhibited the good solubility in water, and was given the low critical temperature (LCST) at 35(±1) °C, which closed to human physiological temperature. The critical micelle concentrations (CMC) of P(αClεCL-co-εCL)-g-P(MEO2MA-co-OEGMA) in aqueous solution were investigated to be 2.0 × 10?3, 9.1 × 10?4 and 1.5 × 10?3 mg·mL?1, respectively. The copolymer could self-assemble into sphere-like aggregates in aqueous solution with diverse sizes when changing the environmental temperature. The vial inversion test demonstrated that the graft copolymers could trigger the sol-gel transition which also depended on the temperature.  相似文献   

19.

Background

Post-activation potentiation (PAP) is the phenomenon by which muscular performance is enhanced in response to a conditioning stimulus. PAP has typically been evidenced via improved counter movement jump (CMJ) performance. This study examined the effects of PAP, with and without prior caffeine ingestion, on CMJ performance.

Methods

Twelve male professional soccer players (23?±?5 years) performed two trials of plyometric exercises and sled towing 60 min after placebo or caffeine ingestion (5 mg.kg??1) in a randomized, counterbalanced and double-blinded design. CMJ performance was assessed at baseline and 1, 3 and 5 min after the conditioning stimulus (T1, T3 and T5, respectively).

Results

Two way ANOVA main effects indicated a significant difference in jump height after the PAP protocol (F[3, 11]?=?14.99, P?<?0.001, partial η2?=?0.577). Analysis also indicated a significant difference in CMJ performance across conditions, with caffeine eliciting a greater response (F[1, 11]?=?10.12, P?=?0.009, partial η2?=?0.479). CMJ height was increased at T1, T3 and T5 in caffeine condition (5.07%, 5.75% and 5.40%, respectively; P?<?0.01) compared to baseline. In the placebo condition, jump performance was increased at T3 (4.94%; P?<?0.01) only. Jump height was higher in caffeine condition on T1, T3 and T5 (P?<?0.05) but not on baseline (P?>?0.05) compared to placebo.

Conclusions

The results of this study suggest that acute plyometric and sled towing stimuli enhances jump performance and that this potentiation is augmented by caffeine ingestion in male soccer players.
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20.
Varady KA  Lamarche B 《Lipids》2011,46(12):1163-1167
Recently, a new cost-effective and less labor-intensive technique termed the “lipoprint LDL system” was developed to measure LDL particle size. However, the agreement between lipoprint and previously validated techniques, such as polyacrylamide gradient gel electrophoresis (PGGE), has never been tested. Therefore, we measured LDL size by lipoprint and PGGE in 16 obese subjects at 4 different time points. Lipoprint significantly overestimated (P = 0.003) integrated LDL particle size by 1.1 ± 3.0 Å when compared to PGGE. As for distribution, there was good agreement between methods for the estimation of large, medium, and small particles (mean difference between the methods was <3% for each parameter). Correlational analysis also revealed good relationships between methods for the proportion of large (r = 0.81, P < 0.0001), medium (r = 0.67, P < 0.0001), and small (r = 0.73, P < 0.0001) particles. In sum, although there is good agreement between lipoprint and PGGE for the determination of LDL size distribution, absolute LDL size values may differ between the two methods.  相似文献   

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