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1.
Vegetative nuclear division in the homokaryotic and dikaryotic hyphae ofCyathus olla Brodie,C. setosus Brodie andC. bulleri Brodie was investigated. In the homokaryotic hyphae a nucleolus develops within a globular condensed nucleus consisting of a folded up filament. As the nucleolus increases in size, the nucleus unfolds and can assume a ring, horseshoe or filament configuration. The filament duplicates and (usually when unwound from the nucleolus) divides longitudinally. Occasionally, strand separation occurs while the filament is wrapped in the form of a ring around the nucleolus. The daughter nuclei may condense before the next division. In the dikaryotic hyphae the same nuclear cycle occurs as in the homokaryons except that an extra nuclear condensation to the globular form can occur in both the clamp and tube nuclei. The division of these two nuclei is not always synchronous and, moreover, the stage of karyokinesis of the clamp nucleus is not closely synchronized with the formation of the clamp connection. A deeply stained granule is associated with the nucleus. Some granules can be observed to be connected to the nucleus by a faintly Feulgen positive thread-like structure but other granules are sessile. The granule or centriole-like body is thought to direct the nuclear unfolding process. It may divide prior to, or after nuclear division. 相似文献
2.
Sullivan C. E.; Kozar L. F.; Murphy E.; Phillipson E. A. 《Journal of applied physiology》1978,45(1):11-17
3.
Whole-body cryotherapy (WBC) involves exposing minimally dressed participants to very cold air (injecting liquid nitrogen with temperature −195 °C), either in a specially designed chamber (cryo-chamber) or cabin (cryo-cabin), for a short period of time. The aim of this study was to examine the actual temperature of the air in the cryo-cabin at different locations throughout the cabin by using human subjects and a manikin. Additionally, we monitored skin temperature before and for 60 min after the cryo-cabin session. Twelve subjects completed one 3 min cryo-cabin session. Temperature next to the skin was assessed during the session, while the skin temperature was monitored before, 3 min after and every 10 min for 60 min after completing the session. There was a statistically significant interaction (time×position) for temperature among the different body parts during the WBC, and for skin temperature among different body parts after the cryo-cabin session. Statistically significant time effects during and following cryo-cabin session were present for all body parts. We showed that actual temperature in the cryo-cabin is substantially different from the one reported by the manufacturer. Thermal response after cryo-cabin session is similar to response observed after cryo-chamber cold exposure reported in previously published studies. This could be of great practical value as cryo-cabins are less expensive and easier to use compared to cryo-chambers. 相似文献
4.
Davide Menga Francisco Ruiz‐Zepeda Lonard Moriau Martin ala Friedrich Wagner Burak Koyutürk Marjan Bele Ura Petek Nejc Hodnik Miran Gaber
ek Tim‐Patrick Fellinger 《Liver Transplantation》2019,9(43)
Atomically dispersed Fe–N–C catalysts are considered the most promising precious‐metal‐free alternative to state‐of‐the‐art Pt‐based oxygen reduction electrocatalysts for proton‐exchange membrane fuel cells. The exceptional progress in the field of research in the last ≈30 years is currently limited by the moderate active site density that can be obtained. Behind this stands the dilemma of metastability of the desired FeN4 sites at the high temperatures that are believed to be a requirement for their formation. It is herein shown that Zn2+ ions can be utilized in the novel concept of active‐site imprinting based on a pyrolytic template ion reaction throughout the formation of nitrogen‐doped carbons. As obtained atomically dispersed Zn–N–Cs comprising ZnN4 sites as well as metal‐free N4 sites can be utilized for the coordination of Fe2+ and Fe3+ ions to form atomically dispersed Fe–N–C with Fe loadings as high as 3.12 wt%. The Fe–N–Cs are active electocatalysts for the oxygen reduction reaction in acidic media with an onset potential of E0 = 0.85 V versus RHE in 0.1 m HClO4. Identical location atomic resolution transmission electron microscopy imaging, as well as in situ electrochemical flow cell coupled to inductively coupled plasma mass spectrometry measurements, is employed to directly prove the concept of the active‐site imprinting approach. 相似文献
5.
Andrew M Jobbins Nejc Haberman Natalia Artigas Christopher Amourda Helen A B Paterson Sijia Yu Samuel J I Blackford Alex Montoya Marian Dore Yi-Fang Wang Alessandro Sardini Inês Cebola Johannes Zuber Sheikh
Tamir Rashid Boris Lenhard Santiago Vernia 《Nucleic acids research》2022,50(6):3379
Pre-mRNA processing is an essential mechanism for the generation of mature mRNA and the regulation of gene expression in eukaryotic cells. While defects in pre-mRNA processing have been implicated in a number of diseases their involvement in metabolic pathologies is still unclear. Here, we show that both alternative splicing and alternative polyadenylation, two major steps in pre-mRNA processing, are significantly altered in non-alcoholic fatty liver disease (NAFLD). Moreover, we find that Serine and Arginine Rich Splicing Factor 10 (SRSF10) binding is enriched adjacent to consensus polyadenylation motifs and its expression is significantly decreased in NAFLD, suggesting a role mediating pre-mRNA dysregulation in this condition. Consistently, inactivation of SRSF10 in mouse and human hepatocytes in vitro, and in mouse liver in vivo, was found to dysregulate polyadenylation of key metabolic genes such as peroxisome proliferator-activated receptor alpha (PPARA) and exacerbate diet-induced metabolic dysfunction. Collectively our work implicates dysregulated pre-mRNA polyadenylation in obesity-induced liver disease and uncovers a novel role for SRSF10 in this process. 相似文献
6.
Tercelj M Ales A Rott T Sever N Prodnik L Erzen J Primic-Zakelj M Rylander R 《Acta cytologica》2008,52(5):584-590
OBJECTIVE: To measure cell nuclei characteristics, previously reported to express probability for lung cancer, in subjects with different forms ofpulmonary disease and those without disease. STUDY DESIGN: Sputum and buccal cell samples were obtained from 846 patients without pulmonary disease, with nonmalignant disease, chronic obstructive pulmonary disease, asbestosis and lung cancer, stained for DNA, scanned by cytometer and scored. This was related to specificity and sensitivity for lung cancer. At score 4.5 sensitivity was 53.8% and specificity 70.9%. This score and higher were defined as high scores (HS) and used to compare groups with lung cancer and other pulmonary disease. RESULTS: Among subjects without disease, 21.1% had HS in sputum cells. Among those with nonmalignant pulmonary disease, 31.7% had HS, and among subjects with lung cancer, 53.8% had it. Repeated evaluations showed that about one third of those with HS on the first occasion were normal on repeat sampling. Among subjects without lung cancer, 33.8% of never-smokers had sputum cell HS compared to 22.7.2% among smokers. CONCLUSION: Results demonstrate that the DNA cellular characteristics on cytometry were more frequent among subjects with lung cancer but also among subjects with other pulmonary disease compared to subjects witbout pulmonary disease. 相似文献
7.
Trace analysis of muramic acid in indoor air using an automated derivatization instrument and GC-MS(2) or GC-MS(3) 总被引:1,自引:0,他引:1
An automated derivatization instrument has been developed for the preparation of alditol acetates from bacterial hydrolysates for analysis by gas chromatography-mass spectrometry (GC-MS). The current report demonstrates the utility of the automated instrument for the more demanding task of trace analysis of muramic acid (Mur) in airborne dust using gas chromatography-tandem mass spectrometry (GC-MS(2)). Conditions for efficient derivatization of Mur, vital for trace analysis, are rigorous including lactam and imido group formation under anhydrous conditions. Furthermore, as the detection limit is lowered, possible contamination or carry-over of samples becomes an increasingly greater consideration and must not occur. The instrument meets these criteria and was successfully used for assaying the levels of Mur in laboratory air, which were found to be much lower than in the previous studies of heavily occupied schools and agricultural environments. The potential for GC-MS(3) in further lowering the detection limit was also demonstrated. 相似文献
8.
Mi?a Mojca Cajnko Maja Maru?i? Matic Kisovec Nejc Rojko Mojca Ben?ina Simon Caserman Gregor Anderluh 《PloS one》2015,10(6)
Listeria monocytogenes is a food and soil-borne pathogen that secretes a pore-forming toxin listeriolysin O (LLO) as its major virulence factor. We tested the effects of LLO on an intestinal epithelial cell line Caco-2 and compared them to an unrelated pore-forming toxin equinatoxin II (EqtII). Results showed that apical application of both toxins causes a significant drop in transepithelial electrical resistance (TEER), with higher LLO concentrations or prolonged exposure time needed to achieve the same magnitude of response than with EqtII. The drop in TEER was due to pore formation and coincided with rearrangement of claudin-1 within tight junctions and associated actin cytoskeleton; however, no significant increase in permeability to fluorescein or 3 kDa FITC-dextran was observed. Influx of calcium after pore formation affected the magnitude of the drop in TEER. Both toxins exhibit similar effects on epithelium morphology and physiology. Importantly, LLO action upon the membrane is much slower and results in compromised epithelium on a longer time scale at lower concentrations than EqtII. This could favor listerial invasion in hosts resistant to E-cadherin related infection. 相似文献
9.
Mouse development and cell proliferation in the absence of D-cyclins 总被引:41,自引:0,他引:41
Kozar K Ciemerych MA Rebel VI Shigematsu H Zagozdzon A Sicinska E Geng Y Yu Q Bhattacharya S Bronson RT Akashi K Sicinski P 《Cell》2004,118(4):477-491
D-type cyclins (cyclins D1, D2, and D3) are regarded as essential links between cell environment and the core cell cycle machinery. We tested the requirement for D-cyclins in mouse development and in proliferation by generating mice lacking all D-cyclins. We found that these cyclin D1(-/-)D2(-/-)D3(-/-) mice develop until mid/late gestation and die due to heart abnormalities combined with a severe anemia. Our analyses revealed that the D-cyclins are critically required for the expansion of hematopoietic stem cells. In contrast, cyclin D-deficient fibroblasts proliferate nearly normally but show increased requirement for mitogenic stimulation in cell cycle re-entry. We found that the proliferation of cyclin D1(-/-)D2(-/-)D3(-/-) cells is resistant to the inhibition by p16(INK4a), but it critically depends on CDK2. Lastly, we found that cells lacking D-cyclins display reduced susceptibility to the oncogenic transformation. Our results reveal the presence of alternative mechanisms that allow cell cycle progression in a cyclin D-independent fashion. 相似文献
10.