The combined impact of xylo-oligosaccharides and gamma-irradiated astragalus polysaccharides on the immune response, antioxidant capacity, and intestinal microbiota composition of broilers.

The present study investigated the individual and combined effects of xylo-oligosaccharides (XOS) and gamma-irradiated astragalus polysaccharides (IAPS) on the immune response, antioxidant capacity and intestinal microbiota composition of broiler chickens. A total of 240 newly hatched Ross 308 chicks were randomly allocated into 5 dietary treatments including the basal diet (control), or the basal diet supplemented with 50 mg/kg chlortetracycline (CTC), 100 mg/kg XOS (XOS), 600 mg/kg IAPS (IAPS), and 100 mg/kg XOS + 600 mg/kg IAPS (XOS + IAPS) respectively. The results showed that birds in the control group had lower the thymus index and serum lysozyme activity than those in the other 4 groups (P < 0.05). Moreover, there was an interaction between XOS and IAPS treatments on increasing the serum lysozyme activity (P < 0.05). Birds in the CTC and XOS + IAPS groups had lower serum malondialdehyde concentration and higher serum total antioxidant capacity activity and mucosal interleukin 2 mRNA expression of jejunum than those in the control group (P < 0.05). In addition, birds in the control groups had lower duodenal and jejunal IgA-producing cells number than these in other 4 groups (P < 0.05). As compared with the CTC group, dietary individual XOS or IAPS administration increased duodenal IgA-producing cells number (P < 0.05). Meanwhile, there was an interaction between XOS and IAPS treatments on increasing duodenal and jejunal IgA-Producing cells numbers (P < 0.05). Dietary CTC administration increased the proportion of Bacteroides, and decreased the proportion of Negativibacillus (P < 0.05). However, dietary XOS + IAPS administration increased Firmicutes to Bacteroidetes ratio, the proportion of Ruminococcaceae, as well as decreased the proportion of Barnesiella and Negativibacillus (P < 0.05). In conclusion, the XOS and IAPS combination could improve intestinal mucosal immunity and barrier function of broilers by enhancing cytokine gene expression, IgA-producing cell production and modulates cecal microbiota, and the combination effect of XOS and IAPS is better than that of individual effect of CTC, XOS, or IAPS in the current study.

Microbiota populations and short-chain fatty acids production in cecum of immunosuppressed broilers consuming diets containing γ-irradiated Astragalus polysaccharides.

This study was designed to evaluate the effects of γ-irradiated Astragalus polysaccharides (IAPS) on growth performance, cecal microbiota populations, and concentrations of cecal short-chain fatty acids of immunosuppressed broilers. A total of 144 one-day-old broiler chicks were randomly assigned into 3 groups: nontreated group (control), cyclophosphamide (CPM)-treated groups fed either a basal diet or the diets containing 900 mg/kg IAPS, respectively. On day 16, 18, and 20, broilers in the control group were intramuscularly injected with 0.5 mL sterilized saline (0.75%, wt/vol), and those in the CPM and IAPS groups were intramuscularly injected with 0.5 mL CPM (40 mg/kg of BW). The trial lasted 21 d. Compared with the control group, CPM treatment decreased the broiler average daily gain (ADG) and feed intake (P < 0.05) but did not affect the overall microbial diversity and compositions, as well as the concentrations of cecal acetate, propionate, and butyrate in cecum of broilers (P > 0.05). Dietary IAPS supplementation increased broiler ADG, Shannon index, and decreased Simpson index (P < 0.05). Specifically, broilers fed diets containing IAPS showed lower abundances of Faecalibacterium, Bacteroides, and Butyricicoccus and higher proportions of Ruminococcaceae UCG-014, Negativibacillus, Shuttleworthia, Sellimonas, and Mollicutes RF39_norank, respectively (P < 0.05). The IAPS treatment also increased butyrate concentration (P < 0.05) and tended to elevate acetate concentration (P = 0.052) in cecal digesta. The results indicated that IAPS are effective in increasing the cecal beneficial bacteria and short-chain fatty acids production, contributing to improvement in the growth performance of immunosuppressive broilers. These findings may expand our knowledge about the function of modified Astragalus polysaccharides in broiler chickens.

Glucose and lipid metabolism of broiler chickens fed diets with graded levels of corn resistant starch.

1. The aim of this study was to investigate the effects of graded levels of dietary corn resistant starch (RS) on glucose and lipid metabolism of broilers. 2. A total of 320 male broiler chicks (Arbor Acres, one-day-old) were randomly allocated to five dietary treatments, including a corn-soybean control diet, a corn-soybean based diet containing 20% corn starch, and three diets containing 4%, 8% and 12% RS by replacing corn starch with 6.67%, 13.33% and 20% Hi-Maize® 260 (identified as control, RS1, RS2, RS3 and RS4, respectively). Each treatment contained eight replicates with eight birds, and the experiment lasted 42 days. 3. Birds fed RS diets showed lower (P < 0.05) concentrations of serum low-density lipoprotein cholesterol and non-esterified fatty acid (NEFA) at d 21 and 42 of age, compared to the control. Lower (P < 0.05) hepatic apolipoprotein B concentration and citrate synthase (CS) activity, as well as a higher (P < 0.05) glycogen synthase (GS) concentration were observed in birds fed RS diets than those in the control group at d 21 of age. Consuming RS diets linearly increased (P < 0.01) serum glucose concentration, and linearly decreased (P < 0.01) NEFA concentrations in broilers at d 21 and 42 of age. Liver GS concentration and activities of hexokinase, pyruvate and CS were linearly increased (P < 0.01) in broilers at d 21 of age, but were linearly decreased (P < 0.05) in birds at d 42 of age in response to the increase of dietary RS levels. Feeding RS diets linearly decreased (P < 0.05) mRNA expressions of PC, PPARα and CPT-1 at d 21 of age and the mRNA expressions of SREBP-1 c, ChREBP, ACC and FAS at d 42 of age, and linearly increased (P < 0.05) the mRNA expressions of PEPCK, PC, LKB1, AMPKα1, PPARα, CPT-1 and L-FABP at d 42 of age. 4. Feeding broilers with diets containing higher concentration of RS promoted hepatic lipolysis and gluconeogenesis through activated AMPK signalling pathway and accelerated whole-body energy expenditures in the grower phase.

Doubly guaranteed mechanism for pollination and fertilization in Ipomoea purpurea.

Flowers, the reproductive organs of angiosperms, show a high degree of diversity in morphological structure and flowering habit to ensure pollination and fertilization of the plants. Effect of flower movement on pollination and fertilization was investigated in Ipomoea purpurea (Convolvulaceae) in this study. Fluorescence microscopy was used to observe the germination of pollen grains at different temperatures. From 04:00 to 06:00 h, the stigma was taller than the filaments, so that self-pollination could not occur, and cross-pollination was carried out by insects. Pollen grains germinated rapidly after falling on the stigma; the pollen tube reached the ovule to complete fertilization after 2-3 h. From 07:00 to 09:00 h, filaments of two stamens grew rapidly and reached the same height as the stigma, thus allowing self-crossing. But at this time, the ambient temperature was already high and was not conducive to the germination of pollen grains. The corolla closed, forming an inverted bell shape, where the inner microenvironment ensured completion of pollen germination and fertilization. Preferential cross-pollination and delayed self-crossing of I. purpurea provided a doubly guaranteed mechanism for pollination and fertilization, facilitating its adaptation to a high temperature climate.

Growth performance, carcass traits and digestive function of broiler chickens fed diets with graded levels of corn resistant starch.

1. This study was conducted to assess the effects of graded levels of dietary corn resistant starch (RS) on growth performance, carcass traits, nutrient retention, digestive organ index, intestinal morphology, digestive enzyme activities, and mRNA expression of certain nutrient transporters in broiler chickens.2. A total of 320, 1-d-old Arbor Acres broiler chickens were randomly assigned to five dietary treatments, with eight replicates of eight birds in each. These treatments included one corn-soybean control diet, a corn-soybean based diet containing 20% corn starch, and three diets supplemented with 4%, 8% and 12% RS by replacing corn starch with 6.67%, 13.33% and 20% of Hi-Maize 260® (identified as control, RS1, RS2, RS3 and RS4, respectively). The feeding period lasted 42 days.3. Performance parameters including feed consumption, feed conversion, body weight gain and percentage of abdominal fat at d 42 of age, nutrient retention (including dry matter, fat, total starch and nitrogen free extract), and apparent metabolisable energy was measured from d 18 to 20 and d 39 to 41 and showed negative linear responses to increasing dietary RS level (P < 0.05). Birds fed the RS3 and RS4 diets showed higher relative weight of duodenum, jejunum and ileum, as well as lower villus height and villus height/crypt depth compared to the control (P < 0.05). The activity of pancreatic trypsin of birds at d 21 and 42 of age decreased linearly in response to the increase of dietary RS level (P < 0.01). There were linear changes in up-regulated mRNA expression of SGLT-1 and down-regulated mRNA expression of GLUT-2 with increasing proportion of RS at d 21 and 42 of age (P < 0.05), respectively.4. It was concluded that feeding broilers with diets containing higher concentrations of RS impaired the development of small intestine, which resulted in lower apparent total tract retention of nutrients and poorer body weight gain, feed efficiency and carcass traits of broiler chickens.

Ingenious floral structure drives explosive pollination in Hydrilla verticillata (Hydrocharitaceae).

In explosive pollination, many structures and mechanisms have evolved to achieve high-speed stamen movement. The male flower of the submerged plant Hydrilla verticillata is reported to be able to release pollen explosively some time after leaving the mother plant time, but the mechanism of stamen movement and the related functional structure in this species are unclear. In this study, we observed the male flower structure and pollen dispersal process of H. verticillata. We analysed the stamen movements during the pollen dispersal process and conducted several controlled experiments to study the process of storage and release of elastic potential energy in explosive pollination. When the male flower of H. verticillata is bound to the united bracts, the sepals accumulate elastic potential energy through the expansion of basal extensor cells. After the male flower is liberated from the mother plant, the stamens unfold rapidly with the sepals under adhesion and transfer the elastic potential energy to the filament in seconds. Once stamens unfold to a critical angle, at which the elasticity of the filament just exceeds the adhesion between sepals and anthers, the stamens automatically rebound and release pollen in milliseconds. These results reveal that Catapult-like stamens, spoon-shaped sepals and enclosed united bracts in the spathe together constitute the functional structure in rapid stamen movement of H. verticillata. They ensure that the pollen can be released on the water surface, and thus adapt successfully to the pollen-epihydrophilous pollination.

Protective effects of γ-irradiated Astragalus polysaccharides on intestinal development and mucosal immune function of immunosuppressed broilers.

This study was aimed to assess the protective effects of γ-irradiated Astragalus polysaccharides (IAPS) on the development of small intestine and intestinal mucosal immunity of immunosuppressed broilers induced by cyclophosphamide (CPM). A total of 384 one-day-old broiler chicks with similar initial weight were randomly assigned into 6 groups: non-treated group (control), and CPM-treated groups fed either a basal diet or the diets containing 900 mg/kg APS, or 900, 600, 300 mg/kg IAPS, respectively. On days 16, 18, and 20, all broilers except for control group were intramuscularly injected with 0.5 mL CPM (40 mg/kg of BW). Broilers in the control group were intramuscularly injected with 0.5 mL sterilized saline (0.75%, wt/vol). This trial was lasted for 21 d. The results revealed that both APS and IAPS treatment elevated the duodenal IgA-producing cells number and the jejunal mRNA expression of interleukin-2 (IL-2), interleukin-10 (IL-10), and interferon γ of CPM-injected broilers (P < 0.05). The decreased jejunal villus height (VH), the ratio of VH to crypt depth (V/C), as well as the intestinal intraepithelial lymphocytes (IELs) and goblet cells number in CPM-injected broilers were elevated by dietary supplementation with 900 mg/kg APS or 900, 600 mg/kg IAPS (P < 0.05). The CPM-induced decrease in jejunum index, the duodenal VH and the jejunal IgA-producing cells number were only improved in the 900 mg/kg IAPS group (P < 0.05). Furthermore, the number of IELs and IgA-producing cells in duodenum, VH, V/C, the number of goblet cells, and mRNA expression of IL-2 and IL-10 in jejunum were higher in the 900 mg/kg IAPS group than those in the 900 mg/kg APS group (P < 0.05). In summary, IAPS possessed stronger immunomodulatory effect than APS at the same supplementation level. Therefore, gamma irradiation can be used as an alternative treatment to enhance the immunomodulatory activity of APS.

Attenuating effects of guanidinoacetic acid on preslaughter transport-induced muscle energy expenditure and rapid glycolysis of broilers.

This study evaluated the effects of dietary guanidinoacetic acid (GAA) supplementation on growth performance, plasma variables, muscle energy status, glycolytic potential, and meat quality of broilers experiencing transport stress during the summer. A total of 320 28-day-old male Arbor Acres broilers were randomly allotted to 3 dietary treatments, including a GAA-free basal control diet (160 birds) and basal diet supplementation with 600 (80 birds) or 1,200 mg/kg (80 birds) GAA for 14 D. On the morning of day 42, after an 8-h fast, the birds fed basal diets were divided into 2 equal groups, and all birds in the 4 groups of 80 birds were transported according to the following protocols: 1) a 0.5-h transport of birds on basal diets (as a lower-stress control group), 2) a 3-h transport of birds on basal diets, and a 3-h transport of birds on basal diets supplemented with either 3) 600 or 4) 1,200 mg/kg GAA. The results revealed that dietary supplementation with GAA at 600 and 1,200 mg/kg for 14 D prior to slaughter did not affect growth performance, carcass traits, and most textural characteristics and chemical composition of the pectoralis major (PM) muscle (P > 0.05). In the GAA-free group, a 3-h transport increased the broiler live weight loss, elevated the plasma corticosterone concentration, decreased the plasma glucose concentration, muscle concentrations of ATP, creatine and energy charge value, increased the muscle AMP concentration and AMP/ATP ratio, and accelerated glycolysis metabolism, which resulted in inferior meat quality (lower pH and higher drip loss, P < 0.05). However, dietary addition of GAA at 1,200 mg/kg increased the mRNA expression of S-adenosyl-l-methionine: N-guanidino-acetate methyltransferase in the liver and creatine transporter in both the liver and PM muscle. It also elevated muscle concentrations of creatine and phosphocreatine (P < 0.05), which helps improve meat quality by ameliorating the 3-h transport-induced muscle energy expenditure and delaying anaerobic glycolysis of broilers.

Unique growth paths of heterospecific pollen tubes result in late entry into ovules in the gynoecium of Sagittaria (Alismataceae).

Pollen-pistil interactions are a fundamental process in the reproductive biology of angiosperms and play a particularly important role in maintaining incipient species that exist in sympatry. However, the majority of previous studies have focused on species with syncarpous gynoecia (fused carpels) and not those with apocarpous gynoecia (unfused carpels). In the present study, we investigated the growth of conspecific pollen tubes compared to heterospecific pollen tubes in Sagittaria species, which have apocarpous gynoecia. We conducted controlled pollinations between S. pygmaea and S. trifolia and observed the growth of conspecific and heterospecific pollen tubes under a fluorescence microscope. Heterospecific and conspecific pollen tubes arrived at locules within the ovaries near simultaneously. However, conspecific pollen tubes entered into the ovules directly, whereas heterospecific tubes passed through the carpel base and adjacent receptacle tissue, to ultimately fertilize other unfertilized ovules. This longer route taken by heterospecific pollen tubes therefore caused a delay in the time required to enter into the ovules. Furthermore, heterospecific pollen tubes displayed similar growth patterns at early and peak pollination. The growth pattern of heterospecific pollen tubes at late pollination was similar to that of conspecific pollen tubes at peak pollination. Heterospecific and conspecific pollen tubes took different routes to fertilize ovules. A delayed entry of heterospecific pollen into ovules may be a novel mechanism of conspecific pollen advantage (CPA) for apocarpous species.

Effect of Selenium Supplementation on Recurrent Hyperthyroidism Caused by Graves' Disease: A Prospective Pilot Study.

The effect of selenium supplementation on recurrent hyperthyroidism caused by Graves' disease is unclear. Our study aimed to assess the efficacy of selenium supplementation therapy on recurrent Graves' disease. Forty-one patients with recurrent Graves' disease were enrolled in this study. All patients received the routine treatment using methimazole (MMI), while patients allocated to the selenium group received additional selenium therapy for 6 months. The influence of selenium supplementation on the concentrations of thyroid stimulating hormone (TSH), anti-TSH-receptor antibodies (TRAb), free thyroxine (FT4), and free triiodothyronine (FT3) were assessed. The remission rate was also compared between 2 groups. There was no obvious difference in the demographic data and the levels of serum FT4, FT3, TSH, and TRAb between the 2 groups at baseline. Both FT4 and FT3 decreased more at 2 months in the selenium group than the controls, while the TSH level increased more in patients receiving selenium supplementation (p<0.05). The TRAb level was significantly lower in patients receiving selenium supplementation (2.4 IU/l vs. 5.6 IU/l, p=0.04). The percentages of patients with normal TRAb level at 6 months was also significantly higher in the selenium group (19.0 vs. 0%, p=0.016). Kaplan-Meier survival curve showed patients receiving selenium supplementation had a significantly higher rate of remission than controls (Log-rank test p=0.008). In conclusion, selenium supplementation can enhance the effect of antithyroid drugs in patients with recurrent Graves' disease. Randomized trials with large number of participants are needed to validate the finding above.

Conservation and population genetic diversity of Curcuma wenyujin (Zingiberaceae), a multifunctional medicinal herb.

Curcuma wenyujin is an important multifunctional medicinal herb in China. Currently, populations of C. wenyujin are decreasing, and wild individuals have almost disappeared from their natural habitats. Moreover, little is known regarding the molecular characteristics of this plant. In this study, we investigated the genetic diversity and variation of five populations of C. wenyujin, using ran-dom amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers. We found that the percentages of polymorphic loci (PPL) at the species level (98.25% by RAPD and 100% by ISSR) were significantly higher than those at the population level (66.32% by RAPD and 67.14% by ISSR). The highest values of PPL, expected heterozygosity, and Shannon's information index were in Pop1, while the lowest values were in Pop2. Both DNA markers revealed a short genetic distance between Pop1 and Pop2 (0.1424 by RAPD and 0.1904 by ISSR). Phylogenetic trees produced similar results, with Pop1, Pop2, and Pop5 in one group and Pop3 and Pop4 in another. There were no significant correlations between their genetic distances and their geographical distances. The highest genetic diversity was in Pop1 and the lowest was in Pop2, and genetic diversity at the species level was relatively low, but much higher than that at the population level. We recommended the establishment of a germplasm bank, in situ con-servation, and propagation of wild individuals. The present study will improve the evaluation, protection, and utilization of the population resources of C. wenyujin.

Effect of dietary creatine monohydrate supplementation on muscle lipid peroxidation and antioxidant capacity of transported broilers in summer.

This experiment was to evaluate the effect of dietary supplementation with creatine monohydrate (CMH) during the finishing period on the muscle lipid peroxidation and antioxidant capacity of broilers that experienced transport stress in summer. A total of 320 male Arbor Acres broilers (28 d in age) were randomly allotted to 3 dietary treatments including a basal control diet without additional CMH (160 birds), or with 600 (80 birds) or 1,200 mg/kg (80 birds) CMH for 14 d. On the morning of d 42, after an 8-h fast, the birds fed the basal diets were divided into 2 equal groups, and all birds in the 4 groups of 80 birds were transported according to the following protocols: 1) a 0.75-h transport of birds on basal diets (as a lower-stress control group), 2) a 3-h transport of birds on basal diets, 3) a 3-h transport of birds on 600 or 4) 1,200 mg/kg CMH supplementation diets. The results showed that the 3-h transport decreased the concentration of creatine (Cr) in both the pectoralis major (PM) and the tibialis anterior (TA) muscles, increased the concentration of phosphocreatine (PCr) and PCr/Cr ratio in PM muscle, and elevated the concentrations of thiobarbituric acid-reactive substances and the activities of total superoxide dismutase and glutathione peroxidase in both the PM and TA muscles of birds (P < 0.05). In addition, transport also upregulated mRNA expression of avian uncoupling protein and heat shock protein 70 in both the PM and TA muscles, as well as avian peroxisome proliferator-activated receptor γ coactivator-1α in the TA muscle (P < 0.05). Dietary supplementation with 1,200 mg/kg CMH increased the concentrations of Cr and PCr in PM muscle, and Cr in TA muscle than those in the 3-h transport group (P < 0.05). However, contrary to our hypothesis, dietary CMH did not alter the measured parameters in relation to muscle lipid peroxidation and antioxidant capacity affected by 3-h transport (P > 0.05). These results indicate that dietary CMH supplementation does not provide any significant protection via directly scavenging free radicals or increased antioxidant capacity of transported broilers.

Allelopathy of the invasive plant Bidens frondosa on the seed germination of Geum japonicum var. chinense.

Five gradient concentrations (0.02, 0.04, 0.06, 0.08, and 0.10 g/mL) of leaching liquors from the roots, stems, and leaves of the invasive plant Bidens frondosa were used as conditioning fluid to examine its influence on seed germination conditions of the native plant Geum japonicum var. chinense in Huangshan. All leaching liquors of organs suppressed the seed germination of Geum japonicum var. chinense and reduced the final germination percentage and rate, and increased the germination inhibition rate, with a bimodal dependence on concentration. The leaching liquor inhibited the seed germination significantly at the concentration of 0.02 g/mL respectively. The seed germination was also inhibited as the concentration reached to 0.04 g/mL and beyond. Hence the allelopathic effects of the organs were significantly enhanced respectively. This phenomenon represented the presence of allelopathy substances in the root, stem and leaf of Bidens frondosa.

Attempts to increase inosinic acid in broiler meat by using feed additives.

To explore regulation of inosinic acid content in chicken meat as a result of feed additives, 576 one-day-old male Arbor Acres broilers were randomly allotted into 8 dietary treatments including control, purine nucleotide (P), betaine (B), soybean isoflavone (S), purine nucleotide + betaine (PB), purine nucleotide + soybean isoflavone (PS), betaine +soybean isoflavone (BS), and purine nucleotide + betaine + soybean isoflavone (PBS) by a 2 × 2 × 2 factorial arrangement. At d 42 of age, broilers were slaughtered, and growth performance, carcass characteristics, inosinic acid content, and activities of enzyme closely related to inosinic acid metabolism of broilers were measured. The results revealed that these feed additives did not affect ADG and ADFI of the broilers (P > 0.05). However, supplementing purine nucleotides lowered feed/gain of broilers in PS and PBS groups (P < 0.05). There was a significant interaction on feed/gain of broilers between purine nucleotides and soybean isoflavone (P < 0.05). The abdominal fat percentages in groups B, S, BS, and PBS were lower than the control group, respectively (P < 0.05). The thigh muscle percentages of groups P and B were higher than that of group PB (P < 0.05). There were certain interactions on the percentage of thigh muscle (P = 0.05) and abdominal fat (P < 0.05) between P, B, and S groups. Compared with the control group, inosinic acid content in broiler breast meat was improved by using feed additives (P < 0.05). Supplementing purine nucleotides, betaine, soybean isoflavone, and their combinations increased alkaline phosphatase activity in breast meat of broilers (P < 0.05). Purine nucleotides improved the activity of adenosine deaminase, but decreased the activity of 5'-nucleotidase. Soybean isoflavone lowered the activity of alkaline phosphatase. There were no significant interactions on activities of creatine kinase, adenosine deaminase, alkaline phosphatase, and 5'-nucleotidase between these additives (P > 0.05). The umami rating of broiler breast meat increased in conjunction with supplementing these additives. In conclusion, supplementing standard feed with the additives investigated in this study could improve inosinic acid content in chicken meat by increasing synthase activity or inhibiting degradation enzyme activity without inferior growth performance and carcass quality.

Effects of dietary supplementation with creatine monohydrate during the finishing period on growth performance, carcass traits, meat quality and muscle glycolytic potential of broilers subjected to transport stress.

A total of 320 male Arbor Acres broiler chickens (28 days old) were randomly allotted to one of the three experimental diets supplemented with 0 (160 birds), 600 (80 birds) or 1200 mg/kg (80 birds) creatine monohydrate (CMH) for 14 days. On the morning of 42 day, after an 8-h fast, the birds of CMH-free group were divided into two equal groups, and all birds of these four groups were transported according to the follow protocol: 0.75-h transport without CMH supplementation (as a lower stress control group), 3-h transport without CMH supplementation, 3-h transport with 600 or 1200 mg/kg CMH supplementation. Each treatment group was composed of 8 replicates with 10 birds each. The results showed that supplementation of CMH for 14 days before slaughter did not affect the overall growth performance and carcass traits of stressed broilers (P>0.05). A 3-h transport decreased plasma glucose concentration, elevated plasma corticosterone concentration, increased bird live weight loss, breakdown of muscle glycogen, as well as the accumulation of muscle lactate (P<0.05), which induced some detrimental changes to breast meat quality (lower ultimate pH and higher drip loss, P<0.05). Nevertheless, supplementation of 1200 mg/kg CMH reduced chicken weight loss, decreased the contents of lactate and glycolytic potential in pectoralis major of 3-h transported broilers (P<0.05), which is beneficial to maintain breast meat quality by reducing the drip loss (P<0.05). These findings suggest that the reduction of muscle glycolysis is probably the reason for maintainance of meat quality by supplementation of CMH in transported broilers.

Enhancement of antibacterial activity of tilmicosin against Staphylococcus aureus by solid lipid nanoparticles in vitro and in vivo.

This study aimed to enhance the antibacterial activity of tilmicosin by solid lipid nanoparticles (SLN). Tilmicosin-loaded hydrogenated castor oil (HCO)-SLN was prepared using a hot homogenisation and ultrasonication method. The physicochemical characteristics of SLN were investigated by scanning electron microscopy (SEM) and photon correlation spectroscopy (PCS). The antibacterial activity of tilmicosin-SLN against Staphylococcus aureus was evaluated by growth inhibition and colony-counting method. A therapeutic study of tilmicosin-SLN was conducted by subcutaneous injection in a mouse mastitis model infected with S. aureus by teat canal infusion. Therapeutic efficacy was assessed by physical appearance of the mammary gland and measurement of colony-forming units (CFU) per gland. The results showed that the diameter, polydispersivity index, zeta potential, encapsulation efficiency and loading capacity of the nanoparticles were 343±26 nm, 0.33±0.08, -7.9±0.4 mV, 60.4±3.3% and 11.2±0.47%, respectively. Tilmicosin-SLN showed a sustained-release effect and sustained and enhanced antibacterial activity in vitro. SLN significantly enhanced the therapeutic efficacy of tilmicosin determined by lower CFU counts and a decreased degree of inflammation. These results demonstrated that the HCO-SLN is an effective carrier to enhance the antibacterial activity of tilmicosin.

Nodeless superconducting gap in A(x)Fe2Se2 (A=K,Cs) revealed by angle-resolved photoemission spectroscopy.

Pairing symmetry is a fundamental property that characterizes a superconductor. For the iron-based high-temperature superconductors, an s(±)-wave pairing symmetry has received increasing experimental and theoretical support. More specifically, the superconducting order parameter is an isotropic s-wave type around a particular Fermi surface, but it has opposite signs between the hole Fermi surfaces at the zone centre and the electron Fermi surfaces at the zone corners. Here we report the low-energy electronic structure of the newly discovered superconductors, A(x)Fe(2)Se(2) (A=K,Cs) with a superconducting transition temperature (Tc) of about 30 K. We found A(x)Fe(2)Se(2) (A=K,Cs) is the most heavily electron-doped among all iron-based superconductors. Large electron Fermi surfaces are observed around the zone corners, with an almost isotropic superconducting gap of ~10.3 meV, whereas there is no hole Fermi surface near the zone centre, which demonstrates that interband scattering or Fermi surface nesting is not a necessary ingredient for the unconventional superconductivity in iron-based superconductors. Thus, the sign change in the s(±) pairing symmetry driven by the interband scattering as suggested in many weak coupling theories becomes conceptually irrelevant in describing the superconducting state here. A more conventional s-wave pairing is probably a better description.

A large iron isotope effect in SmFeAsO(1 - x)F(x) and Ba(1 - x)K(x)Fe(2)As(2).

The recent discovery of superconductivity in oxypnictides with a critical transition temperature (T(C)) higher than the McMillan limit of 39 K (the theoretical maximum predicted by Bardeen-Cooper-Schrieffer theory) has generated great excitement. Theoretical calculations indicate that the electron-phonon interaction is not strong enough to give rise to such high transition temperatures, but strong ferromagnetic/antiferromagnetic fluctuations have been proposed to be responsible. Superconductivity and magnetism in pnictide superconductors, however, show a strong sensitivity to the crystal lattice, suggesting the possibility of unconventional electron-phonon coupling. Here we report the effect of oxygen and iron isotope substitution on T(C) and the spin-density wave (SDW) transition temperature (T(SDW)) in the SmFeAsO(1 - x)F(x) and Ba(1 - x)K(x)Fe(2)As(2) systems. The oxygen isotope effect on T(C) and T(SDW) is very small, while the iron isotope exponent alpha(C) = -dlnT(C)/dlnM is about 0.35 (0.5 corresponds to the full isotope effect). Surprisingly, the iron isotope exchange shows the same effect on T(SDW) as T(C). This indicates that electron-phonon interaction plays some role in the superconducting mechanism, but a simple electron-phonon coupling mechanism seems unlikely because a strong magnon-phonon coupling is included.

Skeletal and hormonal responses to sunlight deprivation in Antarctic expeditioners.

UNLABELLED: Serum 25(OH)D levels decline without sunlight exposure. We studied 120 expeditioners to Antarctica to determine the skeletal and hormonal responses to sunlight deprivation. With emerging vitamin D insufficiency, serum calcium decreased, PTH increased, and bone loss at the proximal femur was observed. Baseline serum 25(OH)D levels >100 nmol/L prevented vitamin D insufficiency. INTRODUCTION: Vitamin D stores deplete without adequate sunlight exposure unless supplementation is provided. We studied 120 healthy adults who spent a year in Antarctica as a model for sunlight deprivation to define the timing and magnitude of the skeletal and hormonal responses to emerging vitamin D insufficiency. METHODS: Fasting blood samples were assessed at baseline, 6 and 12 months for serum 25-hydroxyvitamin D (25(OH)D), osteocalcin (OC), bone formation (P1NP) and resorption (CTx), PTH and calcium. Lumbar spine and proximal femur BMD was measured using DXA. Differences over time were determined using repeated measures ANOVA. Percent changes were expressed as (Delta value/(value A + value B)/2) x 100. Relationships between outcome measures were determined using Spearman's correlations. RESULTS: Vitamin D insufficiency (<50 nmol/L) was observed in 85% of expeditioners by 6 months when serum calcium decreased and PTH increased (p < 0.01). By 12 months, OC increased by 7.4 +/- 3.0% (p < 0.05), and BMD decreased by 1.0 +/- 2.0% at the total proximal femur (p < 0.05). For those with vitamin D sufficiency at baseline (>50 nmol/L), sunlight deprivation produced vitamin D insufficiency within 4 months unless baseline values were >100 nmol/L. CONCLUSION: Supplementation may be necessary for expeditioners with limited access to UV light.

Skeletal benefits from calcium supplementation are limited in children with calcium intakes near 800 mg daily.

INTRODUCTION AND HYPOTHESIS: Calcium supplementation enhances bone mass accrual during administration, with a sustained benefit observed using milk-based calcium but not calcium salts. We tested the hypothesis that calcium from milk minerals but not calcium carbonate will be sustained after supplementation was discontinued. METHODS: Ninety-nine pre-pubertal boys and girls aged 5-11 years were followed for 12 months after being randomized to receive 800 mg/day of calcium from milk minerals (MM) or calcium carbonate (CC), or a placebo (Pla) in a 10-month double blind study. Total body and regional BMC, and femoral shaft bone dimensions were measured using dual energy x-ray absorptiometry. Group differences were determined using ANCOVA. RESULTS: In the intention to treat analysis of the entire sample, no group differences were observed in increments in BMC or bone dimensions during or after supplementation. In those children who remained pre-pubertal, greater gains in pelvis BMC in the milk mineral group than controls were sustained (37.9 versus 29.3% respectively, p<0.02). CONCLUSION: In healthy children consuming about 800 mg calcium daily, calcium supplementation with milk minerals or calcium carbonate does not appear to be produce biologically meaningful benefits to skeletal health. A benefit of calcium supplementation in pre-pubertal was evident, but inconclusive, with the biological significance of the effect of calcium supplementation at the pelvis, and the longevity of this effect to be determined.