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排序方式: 共有233条查询结果,搜索用时 15 毫秒
81.
Maria Grazia PALMERINI Monica ANTINORI Marta MAIONE Fabrizio CERUSICO Caterina VERSACI Stefania Annarita NOTTOLA Guido MACCHIARELLI Mohammad Ali KHALILI Severino ANTINORI 《The Journal of reproduction and development》2014,60(6):411-420
In vitro maturation of vitrified immature germinal vesicle (GV) oocytes is a promising fertility preservation option. We analyzed the ultrastructure of human GV oocytes after Cryotop vitrification (GVv) and compared it with fresh GV (GVc), fresh mature metaphase II (MIIc) and Cryotop-vitrified mature (MIIv) oocytes. By phase contrast microscopy and light microscopy, the oolemmal and cytoplasmic organization of fresh and vitrified oocytes did not show significant changes. GVv oocytes showed significant ultrastructural alterations of the microvilli in 40% of the samples; small vacuoles and occasional large/isolated vacuoles were abnormally present in the ooplasm periphery of 50% of samples. The ultrastructure of nuclei and mitochondria-vesicle (MV) complexes, as well as the distribution and characteristics of cortical granules (CGs), were comparable with those of GVc oocytes. MIIv oocytes showed an abnormal ultrastructure of microvilli in 30% of the
samples and isolated large vacuoles in 70% of the samples. MV complexes were normal, but mitochondria-smooth endoplasmic reticulum aggregates appeared to be of reduced size. CGs were normally located under the oolemma but presented abnormalities in distribution and matrix electron density. In conclusion, Cryotop vitrification preserved main oocyte characteristics in the GV and MII stages, even if peculiar ultrastructural alterations appeared in both stages. This study also showed that the GV stage appears more suitable for vitrification than the MII stage, as indicated by the good ultrastructural preservation of important structures that are present only in immature oocytes, like the nucleus and migrating CGs. 相似文献
82.
Stefania Colombini Andrea Rota Graziosi Pietro Parma Marcello Iriti Sara Vitalini Chiara Sarnataro Mauro Spanghero 《动物营养(英文)》2021,7(1):224
This study investigated the effects of 2 Achillea moschata essential oils extracted from plants collected in 2 different valleys of the Italian Alps and 3 pure compounds of oils — bornyl acetate (BOR), camphor (CAM), and eucalyptol (EUCA) — on in vitro ruminal fermentation and microbiota. An in vitro batch fermentation experiment (Exp. 1) tested the addition of all of the substances (2 essential oils and 3 compounds) in fermentation bottles (120 mL) at 48 h of incubation, whereas a subsequent in vitro continuous culture experiment (Exp. 2) evaluated the pure compounds added to the fermenters (2 L) for a longer incubation period (9 d). In both experiments, total mixed rations were incubated with the additives, and samples without additives were included as the control (CTR). Each treatment was tested in duplicate and was repeated in 3 and 2 fermentation runs in Exp. 1 and 2, respectively. Gas production (GP) in Exp. 1 was similar for all of the treatments, and short chain volatile fatty acid (SCFA) production was similar in both experiments except for a decrease of SCFA produced (P = 0.029) due to EUCA addition in Exp. 2. Compared to CTR, BOR and CAM reduced the valerate proportion (P = 0.04) in Exp. 1, and increased (P < 0.01) the acetate proportion in Exp. 2. All treatments increased (P < 0.01) total protozoa counts (+36.7% and +48.4% compared to CTR on average for Exp. 1 and 2, respectively). In Exp. 1, all of the treatments lowered the Bacteroidetes and Firmicutes and increased the Proteobacteria relative abundances (P < 0.05), whereas in Exp. 2, the EUCA addition increased (P = 0.012) the Ruminococcus. In Exp. 1, methane (CH4) as a proportion of the GP was lowered (P = 0.004) by the addition of CAM and EUCA compared to CTR, whereas in Exp. 2, EUCA reduced the amount of stoichiometrically calculated CH4 compared to CTR. Overall, essential oils extracted from A. moschata and the pure compounds did not depress in vitro rumen fermentation, except for EUCA in Exp. 2. In both experiments, an increase of the protozoal population occurred for all the additives. 相似文献
83.
Vichi S Riu-Aumatell M Mora-Pons M Buxaderas S López-Tamames E 《Journal of agricultural and food chemistry》2005,53(26):10154-10160
A HS-SPME method coupled to GC-MS was developed and applied for the qualitative and semiquantitative characterization of distilled gin volatile fraction. Sampling, chromatographic conditions, and method performances were evaluated, and the developed method was applied as a comparative study of some of the most popular commercial London Dry Gins and other gins with geographic denominations. During this study, 70 components of the gins' volatile fraction were isolated, tentatively identified or identified by reference compounds. They were mainly represented by mono- and sesquiterpenic compounds, which were quantitatively determined. The comparative study of London Dry Gins and gins with geographical indication permitted clear differentiation between the gins with geographical indication and one of the London Dry Gins tested. 相似文献
84.
Paolo Vassallo Chiara Marini Chiara Paoli Michela Bellingeri Frank Dhermain Silvio Nuti Sabina Airoldi Patrizia Bonelli Sophie laran Marie C. Santoni Guido Gnone 《水产资源保护:海洋与淡水生态系统》2020,30(8):1689-1701
- Geospatial models are used to predict the distribution of terrestrial and marine species, according to their ecological and ethological habits. The bottlenose dolphin is a cosmopolitan marine top predator, inhabiting most of the ocean, with the exception of polar and subpolar waters. This wide distribution is associated with a remarkable plasticity in ecological and behavioural habits, which makes it difficult to model and predict its distribution.
- This study proposes a ‘multi‐type approach’ to predict the presence and distribution of the bottlenose dolphin in the Pelagos Sanctuary, a Specially Protected Area of Mediterranean Importance located in the north‐west Mediterranean Sea. A multi‐type model based on random forest regression was developed, analysing the distribution habits of two geographical units living in the Pelagos area.
- When compared with a classical single‐type model, the multi‐type model performed much better in a prediction test (true skill statistics, TSS = 85% vs. 52%), confirming the value of this experimental approach. This work suggests that wild species should not be considered as one single‐type entity, as local specialization may change and shape their distribution habits.
85.
Stefania Dooms Spiros Papakostas Stefan Hoffman Daan Delbare Alexander Triantafyllidis Olav Vadstein Patrick Sorgeloos 《Aquaculture (Amsterdam, Netherlands)》2007,262(1):29-40
Many zooplanktonic organisms, like the cyclic parthenogenetic rotifer Brachionus plicatilis (Rotifera: Monogononta), are actually a complex of species and biotypes with a high degree of morphological similarity (i.e. cryptic species). Various phylogenetic studies with molecular markers (e.g. ITS1 and COI) on wild Brachionus populations described the presence of at least nine genetically divergent Brachionus species and biotypes. Because different studies found evidence that these cryptic species and biotypes differ significantly in ecological preferences and thus probably behave differently in response to rearing conditions in the hatchery, questions rise on the actual identity of the rotifer strains used in aquaculture, where Brachionus discrimination is still based on morphology. This study is a part of an investigation of the genetic make-up of strains used in hatcheries, aquaculture research institutes and laboratories, and describes the rapid and sensitive PCR-DGGE method for the detection of Brachionus species and biotypes based on nucleotide sequence variation within the mitochondrial 16S rRNA gene. Considerable genetic diversity was found, albeit smaller within hatcheries than within laboratories and aquaculture research institutes. All 16S haplotypes produced an unambiguous DGGE fingerprint out of which a database was constructed. 相似文献
86.
Reza Mohammadi Kouresh Nader Mahmoodi Reza Haghparast Stefania Grando Maryam Rahmanian Salvatore Ceccarelli 《Journal of Crop Science and Biotechnology》2011,14(4):281-288
This study was carried out to identify superior barley genotypes for the rainfed areas of western Iran using a participatory
varietal selection (PVS) approach. Three field experiments were conducted in two randomly selected farmers’ fields and in
one rainfed research station in the 2006–07 cropping season with 69 genotypes (including one local and one improved check).
Several univariate and multivariate methods were used to analyze qualitative (farmers’ scores) and quantitative (grain yield)
data. Individual farmers’ scores in each village were positively correlated, indicating that the farmers tended to discriminate
genotypes in similar fashion, although the genotypes actually selected by farmers were different in the two villages. In recent
years, a greater number of farmers in western Iran preferred the improved variety (Sararood-1) over the local barley (Mahali),
while in this project the farmers preferred the new genotypes over the two checks. This was also verified by the quantitative
data showing that the checks were outyielded by the new genotypes. Farmers were efficient in identifying the best genotypes
for their specific environment, as shown by biplot analysis, indicating their competence in selection. The genotypes selected
by the breeder and farmers were almost similar but some differences existed. In conclusion, PVS is a powerful way to involve
farmers for selecting and testing new cultivars that are adapted to their needs, systems and environments. 相似文献
87.
Effects of a selection of additives on in vitro ruminal methanogenesis and in situ and in vivo NDF digestibility
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Mario Pirondini Stefania Colombini Luca Malagutti Luca Rapetti Gianluca Galassi Raffaella Zanchi Gianni Matteo Crovetto 《Animal Science Journal》2015,86(1):59-68
The effects of 18 essential oils, yeast, Quebracho tannin and Quillaja saponin on ruminal methane and gas production (GP) were studied in vitro. A lactating cow diet was incubated with rumen inoculum. Doses of the additives (mg/L) were: essential oils = 500; tannin = 67; yeast = 8.35 and 16.7; and saponin = 300. Lemongrass, estragole, eugenol, geraniol, limonen, thyme oil and thymol produced less gas (overall mean 33.8 mL/200 mg dry matter (DM)) than control (43.6 mL/200 mg DM; P < 0.001). Methane produced (mL/200 mg DM) by guaiacol (10.7), lemongrass (9.6), limonene (11.4), thyme oil (10.9) and thymol (2.1) was lower than control (12.5) (P < 0.001). Methane percentage on total GP was lower (P < 0.001) for cinnamic alcohol (25.4), guaiacol (24.5), thymol (19.7) and vanillin (26.3) than control (28.8). In a second experiment, thymol, guaiacol and yeast were added to the diet of dry fistulated cows to determine in situ neutral detergent fiber digestibility (NDFD) of six forages and in vivo dietary NDFD. Thymol and yeast decreased in situ NDFD after 24 h (33.9% and 33.5% vs. 38.1%; P = 0.008). Thymol decreased in vivo total tract NDFD (40.8% vs. 51.4%; P = 0.02). Differences in GP and methane levels were registered within classes of additives. A careful selection of additives may allow for the manipulation of ruminal fermentation. 相似文献
88.
Karsak M Gaffal E Date R Wang-Eckhardt L Rehnelt J Petrosino S Starowicz K Steuder R Schlicker E Cravatt B Mechoulam R Buettner R Werner S Di Marzo V Tüting T Zimmer A 《Science (New York, N.Y.)》2007,316(5830):1494-1497
Allergic contact dermatitis affects about 5% of men and 11% of women in industrialized countries and is one of the leading causes for occupational diseases. In an animal model for cutaneous contact hypersensitivity, we show that mice lacking both known cannabinoid receptors display exacerbated allergic inflammation. In contrast, fatty acid amide hydrolase-deficient mice, which have increased levels of the endocannabinoid anandamide, displayed reduced allergic responses in the skin. Cannabinoid receptor antagonists exacerbated allergic inflammation, whereas receptor agonists attenuated inflammation. These results demonstrate a protective role of the endocannabinoid system in contact allergy in the skin and suggest a target for therapeutic intervention. 相似文献
89.
Seu R Phillips RJ Alberti G Biccari D Bonaventura F Bortone M Calabrese D Campbell BA Cartacci M Carter LM Catallo C Croce A Croci R Cutigni M Di Placido A Dinardo S Federico C Flamini E Fois F Frigeri A Fuga O Giacomoni E Gim Y Guelfi M Holt JW Kofman W Leuschen CJ Marinangeli L Marras P Masdea A Mattei S Mecozzi R Milkovich SM Morlupi A Mouginot J Orosei R Papa C Paternò T Persi del Marmo P Pettinelli E Pica G Picardi G Plaut JJ Provenziani M Putzig NE Russo F Safaeinili A Salzillo G 《Science (New York, N.Y.)》2007,317(5845):1715-1718
Mars' polar regions are covered with ice-rich layered deposits that potentially contain a record of climate variations. The sounding radar SHARAD on the Mars Reconnaissance Orbiter mapped detailed subsurface stratigraphy in the Promethei Lingula region of the south polar plateau, Planum Australe. Radar reflections interpreted as layers are correlated across adjacent orbits and are continuous for up to 150 kilometers along spacecraft orbital tracks. The reflectors are often separated into discrete reflector sequences, and strong echoes are seen as deep as 1 kilometer. In some cases, the sequences are dipping with respect to each other, suggesting an interdepositional period of erosion. In Australe Sulci, layers are exhumed, indicating recent erosion. 相似文献
90.
Protective effect of the phenolic fraction from virgin olive oils against oxidative stress in human cells 总被引:3,自引:0,他引:3
Manna C D'Angelo S Migliardi V Loffredi E Mazzoni O Morrica P Galletti P Zappia V 《Journal of agricultural and food chemistry》2002,50(22):6521-6526
This paper reports the protective effect of the phenolic fraction extracted from extra virgin olive oils (OOPEs) against the cytotoxic effects of reactive oxygen species in human erythrocytes and Caco-2 cells, employed as model systems. Pretreatment of cells with various OOPEs, indeed, provides a remarkable protection against oxidative damages: this effect was strictly dependent on the o-diphenolic content of the extracts. Moreover, the protective effects observable in cellular systems were compared with in vitro antioxidant properties, measured by using the FRAP (ferric reducing/antioxidant power) assay; the reducing ability of OOPEs strictly parallels their o-phenolic content. The linear relationship demonstrated between biological effects and antioxidant capacity measured by the FRAP assay allows us to propose the use of this rapid colorimetric method in assessing and certifying the antioxidant power of extra virgin olive oil. 相似文献