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11.
12.
Microalgae are well known for their biotechnological potential, namely with regard to bioactive lipidic components—especially carotenoids and polyunsaturated fatty acids (PUFA), well-known for therapeutic applications based on their antioxidant capacity. The aim of this work was to evaluate the influence of four distinct food-grade solvents upon extractability of specific lipidic components, and on the antioxidant capacity exhibited against both synthetic (2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS+•)) and biological reactive species (O2 and NO). A eukaryotic microalga (Scenedesmus obliquus (M2-1)) and a prokaryotic one (Gloeothece sp.) were used as case studies. Concerning total antioxidant capacity, the hexane:isopropanol (3:2) and acetone extracts of Sc. obliquus (M2-1) were the most effective against DPPH and ABTS+•, respectively. Gloeothece sp. ethanol extracts were the most interesting scavengers of O2, probably due the high content of linolenic acid. On the other hand, acetone and hexane:isopropanol (3:2) extracts were the most interesting ones in NO assay. Acetone extract exhibited the best results for the ABTS assay, likely associated to its content of carotenoids, in both microalgae. Otherwise, ethanol stood out in PUFA extraction. Therefore, profiles of lipidic components extracted are critical for evaluating the antioxidant performance—which appears to hinge, in particular, on the balance between carotenoids and PUFAs.  相似文献   
13.
The present work examined the short- and long-term effects of three rearing temperatures on protein metabolism and growth trajectories of Senegalese sole larvae using 14C-labelled Artemia protein as feed. A first feeding trial was performed on larvae reared at 15, 18 and 21 °C (at 26, 17 and 14 days post-hatching (dph), respectively) and a second trial conducted on post-larvae after transfer to the same rearing temperature (~20 °C) (49, 35 and 27 dph, in larvae initially reared at 15, 18 and 21 °C, respectively). Temperature greatly influenced larvae relative growth rate (RGR) and survival, since growth at 15 °C was severely depressed. Protein digestibility and retention was highest at 18 °C during the first trial (85.35 ± 1.16 and 86.34 ± 2.33 %, respectively). However, during the second trial, post-larvae from 15 °C had the highest feed intake and protein digestibility (3.58 ± 1.54 and 75.50 ± 1.35 %, respectively), although retention was similar between treatments. Furthermore, after transfer to 20 °C larvae from 15 °C experienced compensatory growth, which was observed until 121 dph, and confirmed by RGR values, which were significantly higher at 15 ºC than at 21 ºC or 18 ºC. Results from the present study show that Solea senegalensis larval development, survival and protein digestion and retention are highly affected by thermal history.  相似文献   
14.
As mammals are unable to synthesize essential polyunsaturated fatty acids (PUFA), these compounds need to be taken in through diet. Nowadays, obtaining essential PUFA in diet is becoming increasingly difficult; therefore this work investigated the suitability of using macroalgae as novel dietary sources of PUFA. Hence, 17 macroalgal species from three different phyla (Chlorophyta, Phaeophyta and Rhodophyta) were analyzed and their fatty acid methyl esters (FAME) profile was assessed. Each phylum presented a characteristic fatty acid signature as evidenced by clustering of PUFA profiles of algae belonging to the same phylum in a Principal Components Analysis. The major PUFA detected in all phyla were C18 and C20, namely linoleic, arachidonic and eicosapentaenoic acids. The obtained data showed that rhodophytes and phaeophytes have higher concentrations of PUFA, particularly from the n-3 series, thereby being a better source of these compounds. Moreover, rhodophytes and phaeophytes presented “healthier” ∑n-6/∑n-3 and PUFA/saturated fatty acid ratios than chlorophytes. Ulva was an exception within the Chlorophyta, as it presented high concentrations of n-3 PUFA, α-linolenic acid in particular. In conclusion, macroalgae can be considered as a potential source for large-scale production of essential PUFA with wide applications in the nutraceutical and pharmacological industries.  相似文献   
15.
The virulence genes and plasmid profiles of 23 Rhodococcus equi isolates from 258 lymph nodes from domestic pigs (129 nodes with lesions and 129 without lesions) and 120 lymph nodes from slaughtered wild boars (60 nodes with lesions and 60 without) were characterized. R. equi was obtained from 19 lymph nodes of domestic pigs, 17 with, and two without lesions, and from four lymph nodes with lesions, from wild boars. The 23 isolates were tested for the presence of vapA and vapB genes, responsible for the 15–17 and 20 kDa virulence-associated proteins, respectively, by PCR in order to characterize as virulent (VapA), intermediately virulent (VapB) and avirulent. Plasmid DNAs were isolated and analyzed by digestion with restriction endonucleases to estimate size and compare their polymorphisms. Of the 19 domestic pigs strains, seven (36.8%) were avirulent and 12 (63.2%) were intermediately virulent, with the intermediately virulent isolates being plasmid types 8 (8 isolates), 10 (2 isolates), 1 (1 isolate) and 29 (1 isolate). The plasmid type of four strains isolated from wild boars was also intermediately virulent type 8. None of the domestic pigs and wild boar isolates showed the vapA gene. These findings demonstrate a high occurrence of plasmid type 8 in isolates from pigs and wild boars, and the similarity of plasmid types in the domestic pigs, wild boars and human isolates in Brazil.  相似文献   
16.
Optimization of conditions for anthocyanin hydrolysis from red wine was investigated using response surface methodology. The aglycon forms of the anthocyanins were quantified by high-performance liquid chromatography with diode array detection. The combined effects of three independent variables, HCl amount, heating temperature, and hydrolysis time, were studied using a 2(3) full-factorial central composite design. Anthocyanin hydrolysis yield depended mainly on the heating temperature and time of hydrolysis. HCl amount was the factor that least influenced the hydrolysis of anthocyanins. From experimental results, the maximum yield of anthocyanidins was reached with 9.8 mL of HCl (32% v/v), a heating temperature of 166.2 °C, and a hydrolysis time of 46.6 min. Five anthocyanidins, namely, delphinidin, cyanidin, petunidin, peonidin, and malvidin, were quantified in red wine. The reliability of the method was confirmed by recovery experiments, performed under optimal conditions. Recoveries indicated that anthocyanidins resisted the hydrolysis conditions.  相似文献   
17.
In this study, the effects of three diets were investigated to enhance Paracentrotus lividus production for commercial purposes. P. lividus were fed ad libitum for 80 days with: diet A—fresh Codium tomentosum Stackhouse, 1797; diet B—formulated using a jellified mix of macroalgae and vegetables, including C. tomentosum (20%), Coralina sp. Linnaeus, 1758 (17%), cabbage Brassica oleracea var. capitata Linnaeus, 1753 (30%), carrot Daucus carota Linnaeus, 1753 (30%) and agar (3%) as a gelling agent. Diet C consisted of maize Zea mays Linnaeus, 1753 (56%) and New Zealand spinach Tetragonia tetragonoides (Pallas, 1781) Kuntze, 1891 (44%). Their effects on the gonadal and somatic growths, gonadosomatic index (GI) and gametogenesis were evaluated, as well as on the total lipid content and fatty acid composition of sea urchin's gonads. Diet A provided high values of eicosapentaenoic acid (EPA). Gonads of sea urchins fed with diet A were found mostly in growth and maturation stages of gametogenesis and showed the lowest lipid content. Sea urchins fed with diet B presented their gonads in the reabsorption stage and had the highest values of omega‐3 polyunsaturated fatty acids (PUFAs). Sea urchins fed with diet C were in the early stages of gametogenesis and had the highest values of lipid content, plus omega‐6 PUFAs. Once as an ingredient in a balanced mix with vegetables, C. tomentosum can be a key factor to the development of new promising high‐quality and low‐cost feed for P. lividus roe enhancement.  相似文献   
18.
The effect of two anesthetics, 2‐phenoxyethanol (2‐PE) and clove oil (COil) were studied in meagre, Argyrosomus regius. This study aimed to determine the adequate dose of anesthesia for different aquaculture procedures, to assess a sedative or stressor effect of low anesthetic concentrations, and to assess the effect of low anesthetic doses at high fish densities for longer periods of time on fish survival and behavior. Anesthetics were tested at different concentrations: 2‐PE at 100, 250, 400, 550, and 700 mg/L; COil at 25, 40, 55, 70, and 85 mg/L. Meagre became anesthetized within 10 min when using concentrations above 250 mg/L for 2‐PE and above 40 mg/L for COil. Deep anesthesia was achieved at 700 and 85 mg/L, for 2‐PE and COil, respectively. The fish did not react when blood was collected at these concentrations. Plasma cortisol and glucose levels were similar between sedated meagre with both 2‐PE – 100 mg/L and COil – 10 mg/L, and the control (not sedated; P > 0.05). This suggests that low concentrations of these anesthetics induce similar stress response as handling without anesthesia during routine activities. No mortality was registered when meagre was maintained at high densities with low concentrations of each anesthetic for 2 h.  相似文献   
19.
This is a case report of enteric protothecosis caused by Prototheca zopfii in an eight-year-old male mixed breed dog with a history of chronic bloody diarrhea, loss of appetite and weight loss. Algae were isolated from rectal scrapings in defibrinated sheep blood agar and dextrose Sabouraud agar. Cytological evaluation showed the presence of globular and cylindrical organisms with a defined capsule and variable number of endospores, characteristic of the genus Prototheca, in the rectum of the animal. Scanning electron microscopy of P. zopfii strains at different development stages confirmed the diagnosis of algal infection. Molecular identification using a conserved 18S rDNA gene sequence determined that the strain belonged to genotype 2. This report describes success on treatment of canine protothecosis, diagnosed based on clinical, cytological, microbiological, scanning electron microscopy and genotypical findings.  相似文献   
20.
The aim of this study was to evaluate the correlation between the cerebral state index (CSI) and the estimated propofol plasma concentrations in dogs during induction of anaesthesia. Fifteen healthy dogs undergoing scheduled routine surgical procedures were enrolled in this study. Target controlled infusion (TCI) software, based on the pharmacokinetic model for propofol, was used to control the syringe pump and to estimate plasma propofol concentrations (PropCp) and the CSI values every five-seconds. Three electrodes placed in the centre of the forehead, on the left side of the forehead and on the left mastoid were used to collect the electroencephalographic (EEG) signal converted by the cerebral state monitor into the CSI. The cerebral electrical changes induced by increasing propofol concentrations appear to be detected by CSI monitoring in dogs. The negative correlation between CSI and PropCp demonstrates that the CSI could be used to assess electrical brain activity in dogs during the induction of anaesthesia with propofol.  相似文献   
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