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71.
New phenantrene alkaloids from Cryptocarya crassinervia   总被引:1,自引:0,他引:1  
The bark of Cryptocarya crassinervia provided two new phenantrene alkaloids, 2-hydroxyatherosperminine (1) and N-demethyl-2-methoxyatherosperminine (2).  相似文献   
72.
We studied the effects of moist chilling and warming on storage protein mobilization in walnut (Juglans regia L.) kernels to assess the metabolic inhibition theory, which states that dormant seeds are unable to utilize their own food reserves and that cold conditions allow germination by activating hydrolases involved in reserve mobilization. Stratifying kernels at 5 degrees C for 40 days enhanced their germination. During both cold stratification and warm incubation of kernels, storage protein mobilization occurred in cotyledons rather than axes. Kernel amino acid concentration increased during protein mobilization, with axes of warm-incubated kernels having particularly high amino acid concentrations. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE) of the soluble protein fractions from both cold-stratified and warm-incubated cotyledons revealed increased band intensities of putative glutelins (19-22 and 32-35 kDa). A very high molecular weight protease was detected by gelatin SDS-PAGE that was most active at acid to neutral pHs in imbibed, cold stratified and germinated kernels suggesting the protease(s) was synthesized earlier in the mature seeds. Thus, in dormant walnut kernels there is no block to protein mobilization, and imbibition alone is sufficient to initiate proteolysis. Catalase activity was higher in warm-incubated kernels than in cold-stratified kernels, suggesting that seed aging is hastened under warm conditions and that cold stratification in walnut kernels might involve activation of cellular repair mechanisms.  相似文献   
73.
This study was designed to investigate whether the prebiotic mannan‐oligosaccharides (MOS) can reduce the deleterious impacts of feed deprivation on growth and reproduction in zebrafish. In the growth performance experiment, juvenile fish were distributed in the following four treatments: normal‐control (NC), starved‐control (SC), normal‐prebiotic (NP) and starved‐prebiotic (SP). After 8 weeks, NP and SC fish showed the highest and lowest growth patterns, respectively among treatments. Standard length, specific growth rate and feed conversion ratio did not differ significantly between NC and SP treatments. Autochthonous lactic acid bacteria (LAB) were significantly higher in NP and SP than the NC and SP treatments. Feed restriction resulted in significantly lower concentrations of thyroxine. In the reproductive performance experiment, additional juveniles were fed as in the growth experiment. Crossing in the final week of the experiment resulted in successful spawning in only NP fish, which showed mature sperm and oocytes in histological examinations. The number of spermatozoa was significantly lower in the fish that experienced feed restriction; however, the oocytes of SP females were at the same maturation level to that observed in NC females. Sex‐steroids changed after both starvation and MOS supplementation where NC and SP showed no differences in the levels of testosterone and female's 17β‐estradiol. These results indicate that MOS supplemented diet reduced some side effects of feed deprivation (final weight and length, SGR, FCR and levels of LAB and T3), and suggest that supplementation of the diet with MOS may ameliorate some of the negative effects of feed deprivation in zebrafish.  相似文献   
74.
A novel optical chemical sensor based on a transparent electrospun nanofibrous scaffold, composed of polycaprolactam (PA6) and 1,10-phenanthroline (Phen), deposited on a glass slide and impregnated with polyvinyl alcohol (PVA) was coupled with UV-vis spectrophotometry and used for colorimetric determination of ferrous ion (Fe2+) and ascorbic acid (AA). The electrospun nanofibers were characterized using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) techniques. The main factors affecting performance of the optical sensor (PA6-Phen/PVA@glass) including Phen dosage, pH of sample solution, electrospinning time, polymer solution flowrate, electrospinning voltage, and PVA amount were investigated and the related optimum values were obtained. The analytical merits of the sensor for quantitative determination of Fe2+ and ascorbic acid was evaluated. The limit of detection (LOD) and limit of quantification (LOQ) for Fe2+ were 1 and 3 μg mL-1, respectively. The linear dynamic range (LDR) was 3–150 μg mL-1 with the determination coefficient (R2) of 0.991. The relative standard deviation (RSD %, n=3) for a solution of 60 μg mL-1 was 5.4 %. For determination of AA, LOD and LOQ were obtained equal to 0.5 and 2 μg mL-1, respectively. The linear dynamic range was in the 2–200 μg mL-1 range with a R2 of 0.994. The RSD % at 100 μg mL-1, n=3) was equal to 7.0 %. The sensor was applied successfully to the detection of Fe(II) and AA in real water samples and aspirin tablets.  相似文献   
75.
A study was designed to investigate the possible positive prebiotic effects of mannan oligosaccharides (MOS) on growth and reduction of anxiety behaviors in zebrafish (Danio rerio). The experimental diets were supplemented with 0, 2, 4, 6, or 8 g MOS kg?1 and were fed to juvenile fish (0.47 ± 0.017 g) in triplicates for six weeks. Significant differences were found in the final body weight, body weight intake, percent body weight intake, and specific growth rate among treatments. The regression analyses showed that the optimum MOS level was 4–4.1 g MOS kg?1 diet. Fish fed 4 g MOS kg?1 feed showed higher survival than the other treatments. Also, using the novel tank test, fish fed with 4 g MOS kg?1 diet showed lower anxiety by swimming in the upper portion of the tank. The other behavior parameters remained unaffected by the prebiotic. The results indicated the beneficial effect of the prebiotic MOS on growth and partly on welfare of zebrafish juveniles.  相似文献   
76.
In a flock of 425 female and male Nubian goats in the Khartoum Province, an outbreak of a disease causing sudden death of 18 apparently healthy goats occurred (11 females and 7 males, 3-6 years old). Adult Fasciola gigantica were found in the livers of all goats and in seven of them Cysticercus tenuicollis cysts. These organs showed necrotic and severe histopathological changes. Clostridium novyi type B was isolated from necrotic areas of all livers and found to be highly pathogenic and toxigenic to laboratory animals. The disease was diagnosed as infectious necrotic hepatitis (black disease). Faecal examination revealed the presence of F. gigantica eggs. Lymnaea natalensis snails were found to be prevalent in the water canals. As the Khartoum Province is regarded as an endemic area for black disease, routine vaccination is highly recommended for its control in goats and sheep.  相似文献   
77.
Genetic diversity within and among 50 populations of confectionery sunflower (Helianthus annuus L.) collected from different geographical areas of Iran was evaluated by using microsatellite and retrotransposon markers. The number of alleles (Na) in SSR loci ranged from 2 to 3 with an average of 2.1. The polymorphic bands in retrotransposon markers ranged from 7 in locus CR-UR1 to 15 in locus CR-816 with a mean value of 11.33. Herarchical clustering of individuals (50 × 5 = 250) by neighbor joining method in DARwin5 software subdivided them into three groups. Using Bayesian method in the software pakage of Structure, the studied individuals were subdivided into two sub-populations. Principal coordinate analysis revelaed that the two first components explaine 7.86 and 6.16% of the total variance, respectively. Analysis of molecular variance revealed a higher level of genetic variation within (70%) than between (30%) populations. High molecular variation among individuals within population possibly is due to high allogamy nature of the sunflower plant. Low genetic variation observed between populations could be considered as a consequence of genetic equilibrium that has occurred over the long period of cultivation of confectionery sunflower in this area as well as seed exchange among regions. The traditional assumption that selecting genotypes of different geographical origin will maximize the diversity available to a breeding project does not hold in confectionery sunflower.  相似文献   
78.
A total of 336 one‐day‐old Hubbard broiler chickens were randomly distributed among 8 groups, each containing six replicates (7 chickens/replicate). From 1 to 40 days of age, the groups fed the same starter, grower and finisher diets. The control group was unsupplemented; zinc bacitracin (ZnB) group received the antibiotic at 0.5 g/kg; fungal phytase (FP) groups received 250, 500 and 1000 U/kg diet of Aspergillus niger phytase (FP_250, FP_500 and FP_1000 groups), respectively; bacterial phyatse (BP) groups received 250, 500 and 1000 U/kg diet of Escherichia coli phytase (BP_250EP, BP_500EP and BP_1000EP groups) respectively. Considering the whole experimental period, body weight gain was unaffected by ZnB and different concentrations of bacterial and fungal phytase; however, the feed conversion ratio of the group fed a diet supplemented with 500 U of BP was better (p < 0.01) than those fed with a diet supplemented with 500 U of FP. BP_250 group had a higher (p < 0.05) apparent digestibility of ether extract compared to FP_250 group. In conclusion, bacterial phytase at 500 U may enhance performance of broiler chickens fed during days 1–40 of age and yield similar growth performance and economic efficiency to those of eB‐supplemented groups.  相似文献   
79.
Two experiments were carried out to determine the efficiency of supplementation of ram semen extender with caffeine on chilled storage and frozen capacity of spermatozoa. In the first experiment, eighty ejaculates were collected by an artificial vagina from five adult Barki rams, aged 2–3 years and weighted 45.0 ± 2.0 kg throughout the experimental period (January to February 2017). The ejaculates were pooled and diluted (1:10) with tris‐citric egg yolk extender and were split into five groups. Group 1 served as control, whereas groups 2‐5 were supplemented with 0.1, 0.2, 0.3 and 0.4 mM caffeine. All diluted semen specimens were evaluated for physical characteristics immediately after dilution (T0) and throughout preservation period of 48 hr at 4°C. Simultaneously, oxidative stress and indices such as total antioxidant capacity (TAC), malondialdehyde concentrations (MDA) and alkaline transaminase (AKP) concentrations and value of resazurin reduction test (RRT) were determined. In the second experiment, the raw pooled ejaculates were diluted (1:10) with glycerolated tris‐citric egg yolk extender, receiving the previously mentioned caffeine levels. The post‐thaw assessment of cryopreserved spermatozoa, in all groups, was conducted by a computer‐assisted sperm analysis (CASA) system. The results revealed that adding caffeine to ram semen extender at low (0.1 mM) or medium (0.2 mM) levels had positive impact on both physical characteristics of ram sperm and the enzymatic activities compared to the other semen groups. Caffeine supplementation also enhanced post‐thaw sperm dynamics, which implies its potential as an exogenous antioxidant supplement.  相似文献   
80.
Background: The current study was carried out to evaluate the effects of mycotoxin biodegradation agent(MBA, composed of Bacillus subtilis ANSB01 G and Devosia sp. ANSB714) on relieving zearalenone(ZEA) and deoxynivalenol(DON) toxicosis in immature gilts.Methods: A total of forty pre-pubertal female gilts(61.42 ± 1.18 kg) were randomly allocated to four diet treatments: CO(positive control); MO(negative control, ZEA 596.86 μg/kg feed and DON 796 μg/kg feed);COA(CO + 2 g MBA/kg feed); MOA(MO + 2 g MBA/kg feed). Each treatment contained 10 replicates with 1 gilt per replicate. Gilts were housed in an environmentally controlled room with the partially slatted floor.Results: During the entire experimental period of 28 d, average daily gain(ADG) and average daily feed intake(ADFI)of gilts in MO group was significantly reduced compared with those in CO group. The vulva size of gilts was significantly higher in MO group than CO group. In addition, significant increases in the plasma levels of Ig A,Ig G, IL-8, IL-10 and PRL were determined in MO group compared with that in CO group. ZEA and DON in the diet upregulated apoptotic caspase-3 in ovaries and uteri, along with down-regulated the anti-apoptotic protein Bcl-2 in ovaries. The supplementation of MBA into diets co-contaminated with ZEA and DON significantly increased ADG, decreased the vulva sizes, reduced the levels of Ig G, IL-8 and PRL in plasma, and regulated apoptosis in ovaries and uteri of gilts.Conclusions: The present results indicated that feeding diet contaminated with ZEA and DON simultaneously(596.86 μg/kg + 796 μg/kg) had detrimental effects on growth performance, plasma immune function and reproductive status of gilts. And MBA could reduce the negative impacts of these two toxins, believed as a promising feed additive for mitigating toxicosis of ZEA and DON at low levels in gilts.  相似文献   
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