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41.
Journal of Soils and Sediments - 相似文献
42.
Ma&#x;gorzata Malawska Izabela Bojakowska Bogus&#x;aw Wi&#x;komirski 《植物养料与土壤学杂志》2002,165(6):686-691
The concentrations of polycyclic aromatic hydrocarbons (PAHs) were analyzed in samples of peat and of two plant species (Pinus sylvestris and Ledum palustre) overgrowing peat‐bogs in the north‐east of Poland. Peat samples were collected from different depths according to the stratigraphic profile of the peat bogs. The total concentrations of the 16 anthropogenic PAHs (15 from the US EPA list and benzo[e]pyrene) in all peat samples were between 70 and 439 ng g—1. The concentration for the same compounds in pine needles (Pinus sylvestris) and Dutch Myrthe leaves (Ledum palustre) varied between 194 and 1039 ng g—1. A noticeably high fluorene concentration in Dutch Myrthe leaves was found at some sites. In all peat samples 3‐ring compounds were predominant (55 to 319 ng g—1). There were less 4‐ring PAHs (15 to 110 ng g—1) and the least common PAHs were 5‐ring and 6‐ring compounds (0 to 81 ng g—1 for both groups). In some peat samples, the perylene concentration largely exceeds of the total concentration of all the other PAHs investigated. The high content of perylene in bottom layers could result from the processes of perylene sorption from water during peat‐bog formation or from biogenic formation of perylene. 相似文献
43.
Marcin K. Dyderski Anna Gazda Mariusz Hachułka Paweł Horodecki Izabela L. Kałucka Jacek Kamczyc Marek Malicki Remigiusz Pielech Michał Smoczyk Maciej Skorupski Sylwia Wierzcholska Andrzej M. Jagodziński 《Annals of Forest Science》2018,75(4):91
? Key message
Natural regeneration of P. abies (L.) H. Karst. may reach high densities in lower mountain elevations. The highest densities were found in sites with moderate light availability, with low pH, and not near the riverbank. However, age-height classes differed in the predicted magnitude of response, but were consistent in response directions. Mosses and understory species typical of coniferous forests were positively correlated with regeneration density.? Context
Norway spruce Picea abies (L.) H. Karst. in Central Europe is at risk under climate change scenarios, particularly in mountain regions. Little is known about the impact of environmental factors on the natural regeneration of P. abies in low-elevation mountain forests.? Aims
We aimed to assess impacts of distance from the riverbank, soil pH, and light availability on natural P. abies regeneration. We hypothesized that (1) natural P. abies regeneration would depend on light availability and soil pH and (2) there are understory plant species which may indicate the microsites suitable for natural regeneration of P. abies.? Methods
The study was conducted in the Sto?owe Mountains National Park (SW Poland, 600–800 m a.s.l.). We established 160 study plots (25 m2) for natural regeneration, light availability, soil pH, and understory vegetation assessment.? Results
The highest densities of natural regeneration of P. abies were observed in sites with moderate light availability (0.1–0.2 of open sky) and low pH (3.5–4.5), and located relatively far from the riverbank. Cover of 22 understory plant species were correlated with natural P. abies regeneration densities, mostly positively.? Conclusion
Different stages of natural regeneration of P. abies revealed different regeneration niches. Most understory plant species (bryophytes and herbs typical of coniferous forests) do not compete with natural regeneration of P. abies.44.
45.
Woclawek-Potocka I Deptula K Bah MM Lee HY Okuda K Skarzynski DJ 《The Journal of reproduction and development》2004,50(3):333-340
The purpose of this study was to determine whether nitric oxide (NO) mediates tumor necrosis factor (TNF)alpha influence on the bovine endometrium. TNFalpha influence on the bovine endometrium is limited to the stromal cells. Therefore, it was interesting to find out whether NO production by the stromal cells, stimulated by TNFalpha might influence the endometrial epithelium. Moreover, we investigated the intracellular mechanisms of TNFalpha- and NO-regulated prostaglandin (PG) F(2alpha) and PGE(2) synthesis. Epithelial and stromal cells from the bovine endometrium (Days 2-5 of the oestrous cycle) were separated by means of enzymatic dispersion and cultured for 6-7 days in 48-well plates. The confluent endometrial cells were exposed to a NO donor (S-NAP; 1-1000 microM) for 24 h. S-NAP strongly stimulated PGE(2) production in both bovine endometrial cell types (P<0.001). The effect of SNAP on PGF(2alpha) production was limited only to the stromal cells (P<0.05). To study the intracellular mechanisms of TNFalpha and NO action, stromal cells were incubated for 24 h with TNFalpha or S-NAP and with NO synthase (NOS) inhibitor (L-NAME; 10 microM) or an inhibitor of phosphodiesterase (IBMX; 10 microM). When the cells were exposed to TNFalpha in combination with NOS inhibitor (L-NAME), TNFalpha-stimulated PGs production was reduced (P<0.05). The inhibition of enzymatic degradation of cGMP by IBMX augmented the actions of S-NAP and TNFalpha on PGs production (P<0.05). The overall results suggest that TNFalpha augments PGs production by bovine endometrial stromal cells partially via induction of NOS with subsequent stimulation of NO-cGMP formation. NO also stimulates PGE(2) production in epithelial cells. 相似文献
46.
Izabela Janus Małgorzata Kandefer-Gola Rafał Ciaputa Agnieszka Noszczyk-Nowak Urszula Pasławska Massimiliano Tursi Marcin Nowak 《Irish veterinary journal》2015,69(1):18
Background
Dilated cardiomyopathy (DCM) and myxomatous mitral valve disease (MMVD) are the most common diseases noted in dogs. Although their pathogenesis varies, both include a significant enlargement of the left atrium.The study was carried out on left atrial specimens obtained from 56 dogs, including those from 34 dogs with clinically diagnosed MMVD, 15 dogs with DCM and 7 dogs without heart disease (control group). Dogs in the MMVD and the DCM groups presented with left atrial enlargement and stage D heart failure. The specimens underwent immunohistochemical examination using desmin, vimentin, periostin and caspase-3 antibodies.Results
There were alterations in the expression of the studied proteins in the study groups compared to the control group. The changes included: irregularity of desmin cross-striation and desmosomes, a higher amount of vimentin-positive cells, a change in the periostin expression pattern from cytoplasmic to extracellular, and a lower expression of caspase-3. The alterations were more pronounced in the DCM group than in the MMVD group.Conclusions
During heart failure, the pattern of desmin, vimentin, periostin and caspase-3 expression alters in the left atrium, regardless of the cause. The changes are more pronounced in dogs with DCM than in dogs with MMVD and similar left atrial enlargement, suggesting that volume overload may not be the only cause of myocardial changes in DCM.47.
Elzbieta Gujska Joanna Michalak Joanna Klepacka 《Plant foods for human nutrition (Dordrecht, Netherlands)》2009,64(2):129-134
High-performance liquid chromatography was used to study the stability of folate vitamers in two types of rye breads after
baking and 16 weeks of frozen storage. Bread made using sourdough seeds contained less total folate (74.6 μg/100 g dry basis,
expressed as folic acid) than the whole rye flour (79.8 μg/100 g dry basis) and bread leavened only with baker’s yeast (82.8 μg/100 g
dry basis). Most importantly, it was generated by a significant decrease in 5-CH3-H4folate form. The baking process caused some changes in folate distribution. Storage of breads at -18°C for 2 weeks did not
have a significant effect (p < 0.05) on total folates compared to the content directly after baking. After a 5-weeks storage
period, a significant decrease (p < 0.05) in the content of total folates was recorded and it dropped on average by 14% for
both type of breads. After a longer period of storage (16 weeks), a 25% loss of folates in the bread made with baker’s yeast
and a 38% loss in the bread fermented with sourdough seeds was found. Retention of 5-CH3-H4folate and 10-HCO-H2folate forms were much lower in the bread made with a sourdough addition than with baker’s yeast only. 相似文献
48.
Raquel Tatiane Pereira Thaiza Rodrigues de Freitas Izabela Regina Cardoso de Oliveira Leandro Santos Costa Fabricio Andrés Vigliano Priscila Vieira Rosa 《Fish physiology and biochemistry》2017,43(5):1399-1412
Endocrine cells (ECs) act as a luminal surveillance system responding to either the presence or absence of food in the gut through the secretion of peptide hormones. The aim of this study was to analyze the effects of feeding and fasting on the EC peptide-specific distribution along the intestine of Nile tilapia. We assessed the density of ECs producing gastrin (GAS), cholecystokinin-8 (CCK-8), neuropeptide Y (NPY), and calcitonin gene-related peptide (CGRP) in nine segments of the intestine using immunohistochemistry. Our results show that ECs immunoreactive to CCK-8, GAS, NPY, and CGRP can be found along all the intestinal segments sampled, from the midgut to hindgut, although differences in their distribution along the gut were observed. Regarding nutrient status, we found that the anterior segments of the midgut seem to be the main site responding to luminal changes in Nile tilapia. The NPY+ and CGRP+ EC densities increased in the fasted group, while the amount of CCK-8+ ECs were higher in the fed group. No effects of fasting or feeding were found in the GAS+ EC densities. Changes in ECs density were found only at the anterior segments of the intestine which may be due to the correlation between vagus nerve anatomy, EC location, and peptide turnover. Lastly, ECs may need to be considered an active cell subpopulation that may adapt and respond to different nutrient status as stimuli. Due to the complexity of the enteroendocrine system and its importance in fish nutrition, much remains to be elucidated and it deserves closer attention. 相似文献
49.
Kang S Blair JE Geiser DM Khang CH Park SY Gahegan M O'Donnell K Luster DG Kim SH Ivors KL Lee YH Lee YW Grünwald NJ Martin FM Coffey MD Veeraraghavan N Makalowska I 《Phytopathology》2006,96(9):920-925
ABSTRACT Plant pathogen culture collections are essential resources in our fight against plant disease and for connecting discoveries of the present with established knowledge of the past. However, available infrastructure in support of culture collections is in serious need of improvement, and we continually face the risk of losing many of these collections. As novel and reemerging plant pathogens threaten agriculture, their timely identification and monitoring depends on rapid access to cultures representing the known diversity of plant pathogens along with genotypic, phenotypic, and epidemiological data associated with them. Archiving such data in a format that can be easily accessed and searched is essential for rapid assessment of potential risk and can help track the change and movement of pathogens. The underexplored pathogen diversity in nature further underscores the importance of cataloguing pathogen cultures. Realizing the potential of pathogen genomics as a foundation for developing effective disease control also hinges on how effectively we use the sequenced isolate as a reference to understand the genetic and phenotypic diversity within a pathogen species. In this letter, we propose a number of measures for improving pathogen culture collections. 相似文献
50.
Izabela Michalak Ruchi Tiwari Manish Dhawan Mahmoud Alagawany Mayada R. Farag Khan Sharun Talha Bin Emran Kuldeep Dhama 《The Veterinary quarterly》2022,42(1):48
Natural antioxidants applied as feed additives can improve not only animals’ health and overall performance but also increase their resistance to environmental stress such as heat stress, bad housing conditions, diseases, etc. Marine organisms, for example seaweeds – red, brown, and green macroalgae contain a plethora of biologically active substances, including phenolic compounds, polysaccharides, pigments, vitamins, micro- and macroelements, and proteins known for their antioxidant activity, which can help in the maintenance of appropriate redox status in animals and show pleiotropic effects for enhancing good health, and productivity. The dysregulated production of free radicals is a marked characteristic of several clinical conditions, and antioxidant machinery plays a pivotal role in scavenging the excessive free radicals, thereby preventing and treating infections in animals. Supplementation of seaweeds to animal diet can boost antioxidant activity, immunity, and the gut environment. Dietary supplementation of seaweeds can also enhance meat quality due to the deposition of marine-derived antioxidant components in muscles. The use of natural antioxidants in the meat industry is a practical approach to minimize or prevent lipid oxidation. However, overconsumption of seaweeds, especially brown macroalgae, should be avoided because of their high iodine content. An important point to consider when including seaweeds in animal feed is their variable composition which depends on the species, habitat, location, harvest time, growing conditions such as nutrient concentration in water, light intensity, temperature, etc. This review highlights the beneficial applications of seaweeds and their extracted compounds, which have antioxidant properties as feed additives and impact animal health and production. 相似文献