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排序方式: 共有251条查询结果,搜索用时 15 毫秒
61.
Ana Camacho Benítez Rossana Vasconcellos Paula Lombide Helen Viotti William Pérez Nicolás Cazales Daniel Cavestany Graeme B. Martin Graciela Pedrana 《Anatomia, histologia, embryologia》2021,50(1):50-57
Heat shock proteins play a crucial role in cellular development, proliferation, differentiation and apoptosis. Heat shock protein 90 (HSP90) has been localised in the human endometrium, where its immunoexpression changes during the menstrual cycle. Similar studies have not been done for the equid species, so the present study aimed to describe endometrial HSP90 immunoexpression in mare endometrium. Endometrial biopsies were formalin-fixed and paraffin-embedded, and sections were stained with haematoxylin–eosin in preparation for HSP90 immunohistochemistry. Immunostaining and morphometric analyses were performed on the epithelial lining, endometrial glands and connective stroma during oestrus, dioestrus phase and anoestrus period (n = 7 per phase or period). Immunoexpression was localised in the basal region of the epithelial cells lining the lumen. Immunoexpression was greater during oestrus than during either dioestrus or anoestrus. During anoestrus, there was little immunostaining in the endometrium, suggesting that HSP90 is involved in the functional modulation of sex steroid receptors in cyclic mares. Indeed, the function of HSP90 as a chaperone in the folding of proteins, such as steroid receptors, might explain the greater intensity of immunostaining during the oestrus and dioestrus phases, compared the anoestrus period. We conclude that, in the mare, HSP90 plays a role in endometrial function and that further studies are needed to test whether it is important in pathological conditions as endometritis. 相似文献
62.
Fernanda Gabriela Fumuso Mariana Lucía Bertuzzi Nicolás Velásquez González Marcelo H. Miragaya Maria Ignacia Carretero 《Reproduction in domestic animals》2021,56(7):958-964
Semen cryopreservation is not available for massive use in South American Camelids (SACs) due to the lack of an efficient protocol and the low pregnancy rates obtained with artificial insemination (AI). The use of a single cryoprotectant (CP) is commonly used in SACs frozen semen. The objective of the study was to evaluate the combined cryoprotective capacity of two permeable CPs at different stages of the cryopreservation protocol in llama semen. Sixteen ejaculates from 4 llama males were analysed, and sperm quality was assayed in raw semen, at 5°C, after equilibration of samples with the CPs and when samples were thawed. The following CPs and combination were used: 6% glycerol (GL), 6% dimethylformamide (DMF) and the combination of both CPs: 3% GL and 3% DMF. A Kruskal–Wallis test and an experimental factorial design, considering one factor with four levels (raw semen, 6% GL, 6% DMF and GL/DMF), were used. Total sperm motility and live sperm with intact acrosomes remained unchanged after equilibration of samples (p > .05). A significant decrease in the percentage of functional membrane, motile and live sperm with intact acrosomes was observed when samples were thawed (GL, DMF and GL/DMF). Nevertheless, the cryopreservation protocols used preserved sperm DNA quality; thus, sperm chromatin condensation and DNA fragmentation were unaffected (p > .05) when GL, DMF and GL/DMF were used. To conclude, no superiority was found between the use of a single or a combination of permeable cryoprotectants to freeze llama semen. 相似文献
63.
64.
Moreno DA Víllora G Hernández J Castilla N Romero L 《Journal of agricultural and food chemistry》2002,50(7):1964-1969
Accumulation of heavy metals from agricultural soils contaminated by low levels heavy metals has important implications in the understanding of heavy metal contamination in the food chain. Through field experiments (1994-1996), the influence of thermal regime under different treatments on the accumulation of zinc, cadmium, copper, and lead in Chinese cabbage [Brassica pekinensis (Lour) Rupr. cv. Nagaoka 50] grown in a Calcareous Fluvisol (Xerofluvent) in Granada (southern Spain) was examined. Two floating row covers were used: T(1) (perforated polyethylene, 50 microm thick) and T(2) (17 g m(-2) polypropylene nonwoven fleece). An uncovered cultivation (T(0)) served as control. Zn, Cd, Cu, and Pb levels in the whole tops of experimental plants were analyzed. Treatments T(1) and T(2) gave rise to differences in environmental conditions with respect to T(0). The influence of environmental factors manipulated by floating row covers (particularly under T(1)) increased total heavy metal accumulation in the above ground plant biomass with respect to the open-air crop. The total contents of Zn, Cd, Cu, and Pb were 30, 50, 90, and 40% higher in T(1), respectively, than in T(0). This technique could be used in contaminated zones for different plant species because the thermal effect favors the process of phytoextraction and thus reduces the contamination. 相似文献
65.
66.
Mic??l Mastrocicco Nicol?? Colombani Giuseppe Castaldelli Nebo Jovanovic 《Water, air, and soil pollution》2011,217(1-4):83-93
A modeling study on fertilizer by-products fate and transport was performed in an unconfined shallow aquifer equipped with a grid of 13 piezometers. The field site was located in a former agricultural field overlying a river paleochannel near Ferrara (Northern Italy), cultivated with cereals rotation until 2004 and then converted to park. Piezometers were installed in June 2007 and were monitored until June 2009 via pressure transducer data loggers to evaluate the temporal and spatial variation of groundwater heads, while an onsite meteorological station provided data for recharge rate calculations via unsaturated zone modeling. The groundwater composition in June 2007 exhibited elevated nitrate (NO 3 ? ) and chloride (Cl?) concentrations due to fertilizer leaching from the top soil. The spatial distribution of NO 3 ? and Cl? was heterogeneous and the concentration decreased during the monitoring period, with NO 3 ? attenuation (below 10?mg/l) after 650?days. A transient groundwater flow and contaminant transport model was calibrated versus observed heads and NO 3 ? and Cl? concentrations. Cl? was used as environmental tracer to quantify groundwater flow velocity and it was simulated as a conservative species. NO 3 ? was treated as a reactive species and denitrification was simulated with a first order degradation rate constant. Model calibration gave a low denitrification rate (2.5e?3 mg-NO 3 ? /l/d) likely because of prevailing oxic conditions and low concentration of dissolved organic carbon. Scenario modeling was implemented with steady state and variable flow time discretization to identify the mechanism of NO 3 ? attenuation. It was shown that transient piezometric conditions did not exert a strong control on NO 3 ? clean up time, while transient recharge rate did, because it is the main source of unpolluted water in the domain. 相似文献
67.
González-Agüero M Cifuentes-Esquivel N Ibañez-Carrasco F Gudenschwager O Campos-Vargas R Defilippi BG 《Journal of agricultural and food chemistry》2011,59(24):13295-13299
Cherimoyas (Annona cherimola), like other subtropical/tropical fruits, are susceptible to damage from exposure to temperatures between 0 and 5 °C (chilling injury, CI), which may affect fruit quality. To increase our understanding of the molecular mechanisms involved in the CI response, a forward suppression subtractive hybridization (SSH) cDNA library was constructed. In this work, we obtained 75 genes that could potentially be involved in the CI response. The CI induced activation of genes that are involved in a range of metabolic pathways, such as primary metabolism, transport, and endomembrane traffic, among others. We also characterized the expression of 12 selected genes in different A. cherimola tissues by polymerase chain reaction (PCR), and we confirmed the differential expression of a subset in CI fruits by real-time quantitative PCR (qPCR). The expression of six A. cherimola genes: annexin (AcAnex), UDP-glucose pyrophosphorylase (AcUGP), syntaxin of plants 71 (AcSyp71), 1-aminocyclopropane-1-carboxylic-acid synthase (AcACS), ubiquitin carrier-like protein (AcUCP), and enolase (AcEnol), was up-regulated after cold storage for 12 days at 0 °C. These results imply that selected genes could be related to the development of internal browning observed in cherimoyas after exposure to CI conditions. The information generated in this study provides new clues that may aid in understanding the cherimoya ripening process. 相似文献
68.
An instrument for estimating pasture yield electronically was constructed. It was a modification of that described by Campbell et al (1). A transistorized crystal oscillator was incorporated to provide a highly stable frequency standard for use in the field. This provided a zero reference point for both the measuring head oscillator and the reading oscillator before and during use. The instrument is fully described and details are given of its field adjustment and operation. 相似文献
69.
Camarretta Nicolò Harrison Peter A. Bailey Tanya Potts Brad Lucieer Arko Davidson Neil Hunt Mark 《New Forests》2020,51(4):573-596
New Forests - With the demand for, and scale of, ecological restoration increasing globally, effectiveness monitoring remains a significant challenge. For forest restoration, structural complexity... 相似文献
70.
The structure of the upper atmosphere of mars: In situ accelerometer measurements from mars global surveyor 总被引:1,自引:0,他引:1
GM Keating SW Bougher RW Zurek RH Tolson GJ Cancro SN Noll JS Parker TJ Schellenberg RW Shane BL Wilkerson JR Murphy JL Hollingsworth RM Haberle M Joshi JC Pearl BJ Conrath MD Smith RT Clancy RC Blanchard RG Wilmoth DF Rault TZ Martin DT Lyons PB Esposito MD Johnston al et 《Science (New York, N.Y.)》1998,279(5357):1672-1676
The Mars Global Surveyor (MGS) z-axis accelerometer has obtained over 200 vertical structures of thermospheric density, temperature, and pressure, ranging from 110 to 170 kilometers, compared to only three previous such vertical structures. In November 1997, a regional dust storm in the Southern Hemisphere triggered an unexpectedly large thermospheric response at mid-northern latitudes, increasing the altitude of thermospheric pressure surfaces there by as much as 8 kilometers and indicating a strong global thermospheric response to a regional dust storm. Throughout the MGS mission, thermospheric density bulges have been detected on opposite sides of the planet near 90 degreesE and 90 degreesW, in the vicinity of maximum terrain heights. This wave 2 pattern may be caused by topographically-forced planetary waves propagating up from the lower atmosphere. 相似文献