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排序方式: 共有129条查询结果,搜索用时 15 毫秒
91.
92.
Santiago Bonachela Melchor Juan J. Jesús Casas Francisca Fuentes-Rodríguez Irene Gallego María Antonia Elorrieta 《Irrigation Science》2013,31(4):769-780
The influence of pond management on water quality for drip-irrigated crops was studied throughout a field survey and a mesocosm experiment. Water sources were pooled into two groups: ground or surface water (GW/SW) and recycled wastewater. Pond covering, which was limited to about a quarter of them, improved water quality by reducing phytoplankton biomass. However, biocide applications and pond dredging were ineffective at improving in-pond water quality. Dredging did not reduce the concentrations of planktonic chlorophyll a or total suspended solids (TSS) in GW/SW fed ponds, whereas biocide applications increased both parameters. Field and experimental data proved that the two predominant taxa of submerged aquatic vegetation (SAV) found in ponds (Potamogeton pectinatus and Chara spp.) improved water quality by increasing water oxygenation and decreasing chlorophyll a and TSS concentrations. Preserving SAV (especially Chara spp.) appears to be an environment-friendly, cost-effective and recommendable alternative strategy for irrigation pond management. 相似文献
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Kalogeropoulos N Nomikos T Chiou A Fragopoulou E Antonopoulou S 《Journal of agricultural and food chemistry》2008,56(14):5916-5925
Crude composition, lipid composition, and tocopherols, ascorbic acid, cholesterol, phytosterols, and squalene content together with fatty acids and antiplatelet activities of total, neutral, and polar lipids of avgotaracho (wax-covered, dried, and salted Mugil cephalus roe) were studied and compared with those of similar products. Wax and steryl esters accounted for 63.7% of roe lipids followed by phosphatidylcholine (PC), which comprised 20.3%. Wax esters were rich in saturated fatty alcohols, monounsaturated fatty acids, and long chain omega3 highly unsaturated fatty acids (HUFA). The fatty acid distribution in roe total and neutral lipids was similar to that of wax esters, while in polar lipids, the omega3 HUFA predominated. Avgotaracho provides significant amounts of protein, fat, alpha-tocopherol, ascorbic acid, and PC, certain amounts of squalene and phytosterols, and cholesterol at levels comparable to hens' eggs. Total, polar, and neutral lipids of avgotaracho exhibited a strong inhibition of platelet activating factors and thrombin, with polar lipids being more active. The results obtained indicate that avgotaracho is a food of high nutritive value, rich in protein and lipids with a healthy lipid profile in terms of omega3/omega6 ratio and major fatty acid classes, while the antiplatelet activity of its oil indicates a putative antithrombotic potential. 相似文献
95.
Antonia DeJesus Eli B. Cohen Evelyn Galban Jantra Ngosuwan Suran 《Veterinary radiology & ultrasound》2017,58(3):326-333
Intraventricular ependymoma is a rare type of feline intracranial neoplasia and published information on magnetic resonance imaging (MRI) characteristics is currently lacking. The purpose of this retrospective case series study was to describe the clinical and MRI characteristics of histopathologically confirmed intraventricular ependymomas in a group of cats. Five cats met inclusion criteria. In relation to normal gray matter, ependymomas appeared hyperintense on T2W, T2W‐FLAIR, PD, and DW‐EPI images; isointense on ADC images; and had subtle to strong contrast enhancement. Some variability was seen on T2*GRE and on T1W images with masses being isointense to hyperintense. Four ependymomas were small and homogeneous, and one was centrally cavitated. All cats had obstructive hydrocephalus, transtentorial herniation, and foramen magnum herniation. Perilesional edema was identified in most cats but was questionable in one. Intraventricular ependymoma should be considered as a differential diagnosis for cats with this combination of MRI signs. 相似文献
96.
Association between ants (Hymenoptera: Formicidae) and the vine mealybug (Hemiptera: Pseudococcidae) in table‐grape vineyards in Eastern Spain
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97.
Unique processing during a period of high excitation/inhibition balance in adult-born neurons 总被引:1,自引:0,他引:1
The adult dentate gyrus generates new granule cells (GCs) that develop over several weeks and integrate into the preexisting network. Although adult hippocampal neurogenesis has been implicated in learning and memory, the specific role of new GCs remains unclear. We examined whether immature adult-born neurons contribute to information encoding. By combining calcium imaging and electrophysiology in acute slices, we found that weak afferent activity recruits few mature GCs while activating a substantial proportion of the immature neurons. These different activation thresholds are dictated by an enhanced excitation/inhibition balance transiently expressed in immature GCs. Immature GCs exhibit low input specificity that switches with time toward a highly specific responsiveness. Therefore, activity patterns entering the dentate gyrus can undergo differential decoding by a heterogeneous population of GCs originated at different times. 相似文献
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99.
Azucena Ascencio-Cabral Humberto Gutiérrez-Pulido Benjamín Rodríguez-Garay Antonia Gutiérrez-Mora 《Scientia Horticulturae》2008
Difficulties to develop an easy and reproducible protocol to get healthy and well formed plants from somatic embryos of papaya (Carica papaya L.) had included low germination, callus production at the base of the embryo radicle and the occurrence of hyperhydric plantlets among others, and by consequence unsuccessful transfer to the field. With the aim of improving a propagation method, the effects of light quality, gelling agent and phloridzin concentration on the germination of somatic embryos of hermaphrodite C. papaya L. var. Maradol were studied. Somatic embryos were grown on half strength MS medium, with the addition of Chen vitamins [Chen, M.H., Wang, P.J., Maeda, E., 1987. Somatic embryogenesis and plant regeneration in Carica papaya L. tissue culture derived from root explants. Plant Cell Rep. 6, 348–351], solidified with three distinct gelling agents: Sigma® Agar–Agar, Difco® Bacto agar and Phytagel®; supplemented with phloridzin and exposed to different light qualities: blue (54 μmol m−2 s−1), red (65 μmol m−2 s−1), gro-lux (68 μmol m−2 s−1), red + blue, white (32 μmol m−2 s−1) and wide spectrum (49 μmol m−2 s−1) during a period of 4 weeks. Results show that light quality and gelling agent had important effects on germination and plant growth, while 3.0 mg L−1 phloridzin had an important role on germination as well as in root development. Somatic embryos exposed to white light, culture medium solidified with 3.0 mg L−1 phytagel and 3.0 mg L−1 phloridzin showed longer roots. Meanwhile, germination and plant length were promoted on an improved culture medium solidified with 7.5 g L−1 Difco® Bacto agar, 3.0 mg L−1 phloridzin and exposed to gro-lux lamps. Under these conditions, 70% of somatic embryos germinated and developed normal roots without hyperhydricity. The regenerated plantlets with well developed roots and shoots were successfully transferred to a greenhouse with a survival rate of 95%. 相似文献
100.
Anna Carbone Barbara Parrino Gloria Di Vita Alessandro Attanzio Virginia Spanò Alessandra Montalbano Paola Barraja Luisa Tesoriere Maria Antonia Livrea Patrizia Diana Girolamo Cirrincione 《Marine drugs》2015,13(1):460-492
Two new series of nortopsentin analogues, in which the imidazole ring of the natural product was replaced by thiazole and indole units were both substituted by 7-azaindole moieties or one indole unit was replaced by a 6-azaindole portion, were efficiently synthesized. Compounds belonging to both series inhibited the growth of HCT-116 colorectal cancer cells at low micromolar concentrations, whereas they did not affect the viability of normal-like intestinal cells. A compound of the former series induced apoptosis, evident as externalization of plasma membrane phosphatidylserine (PS), and changes of mitochondrial trans-membrane potential, while blocking the cell cycle in G2/M phase. In contrast, a derivative of the latter series elicited distinct responses in accordance with the dose. Thus, low concentrations (GI30) induced morphological changes characteristic of autophagic death with massive formation of cytoplasmic acid vacuoles without apparent loss of nuclear material, and with arrest of cell cycle at the G1 phase, whereas higher concentrations (GI70) induced apoptosis with arrest of cell cycle at the G1 phase. 相似文献