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201.
Rumiana Tzoneva Irina Georgieva Natasha Ivanova Veselina Uzunova Zlatina Nenchovska Sonia Apostolova Tzveta Stoyanova Jana Tchekalarova 《International journal of molecular sciences》2021,22(23)
One of the pathological hallmarks of Alzheimer’s disease (AD) associated with its progression that contributes to β-amyloid (Aβ) generation is oxidative stress (OS). Clinical data suggest that melatonin is a potent antioxidant that might be effective in the adjunctive therapy of this neurodegenerative disease. The present study aimed to explore the role of melatonin on behavioral changes and markers of OS in three rat models, namely, pinealectomy (pin) model of melatonin deficit, intracerebroventricular (icv)Aβ1-42 model of AD, and combination of both pin and Aβ1-42 model (pin+icvAβ1-42). The chronic injection with vehicle/melatonin (50 mg/kg, i.p. for 40 days) started on the same day of sham/pin and icv vehicle/Aβ1-42 infusion procedures. Anxiety in the open field and the elevated plus-maze test and cognitive responses in the object recognition test were tested between the 30th–35th day after the surgical procedures. Markers of OS in the frontal cortex (FC) and hippocampus were detected by the ELISA method. Melatonin treatment corrected the exacerbated anxiety response only in the pin+icvAβ1-42 model while it alleviated the cognitive impairment in the three models. Pinealectomy disturbed the antioxidant system via enhanced SOD activity and decreased GSH levels both in the FC and hippocampus. The Aβ1-42 model decreased the SOD activity in the FC and elevated the MDA level in the two brain structures. The pin+icvAβ1-42 model impaired the antioxidant system and elevated lipid peroxidation. Melatonin supplementation restored only the elevated MDA level of icvAβ1-42 and pin+icvAβ1-42 model in the hippocampus. In conclusion, our study reveals that the pin+icvAβ1-42 rat model triggers more pronounced anxiety and alterations in markers of OS that may be associated with melatonin deficit concomitant to icvAβ1-42-induced AD pathology. 相似文献
202.
As a highly interdisciplinary field, architecture is being influenced by many subjects of natural and social sciences. Biology despite being apparently distant from architecture is currently a scientific field blending into design practices, which have evolved and shifted towards a new hybrid framework. In this article, we present an emerging design field of what we categorize as biomimetic architecture pioneering by six architectural offices in France. We observe the impact of scientific researches on design processes and practices through six case studies led by these offices, which can be seen through the actors who involved in various types of interdisciplinary collaborations, through the competencies of the architect himself, and through new sources of ideas coming from biological sciences and related fields. We propose to use a classification of theoretical uses in modeling practice to better understand the role that biological knowledge plays in architectural design practices. Finally, the result of this analysis shows that the use of biology taking place in a design space has external purposes, which transform it to produce engineering devices or urban schemes rather than architectural projects. It also shows that biology in architectural design induces other kinds of non-biological knowledge, is not strictly theoretical and could be obsolete or approximate. These findings lead to an epistemological discussion concerning the confusion between biological ‘knowledge’ and architectural design ‘know-how’. 相似文献
203.
Zirconium alloys are typically used in nuclear pressurized water reactors (PWR) as fuel cladding tubes due to their chemical stability and their mechanical strength at operating temperatures (≈300 °C). However, the corrosion of Zr-based cladding tubes is one of the factors limiting the burn-off rate in PWRs. It is commonly accepted that the corrosion kinetics involves a periodic succession of growth where the oxide thickness varies parabolically with time. As the oxide thickens, a cracking structure forms. The oxide appears striated with periodic layers of cracks running parallel to the metal/oxide interface. This cracking structure has been experimentally related to the periodicity of the oxide growth. In the present work, a finite-element study is used to investigate the development of stresses in the oxide under the combined influence of molar volume expansion during oxide formation, metal/oxide interface geometry and metallic substrate creep. The generation of tensile stresses capable of initiating the cracks that are observed experimentally is explored. 相似文献
204.
Fedyukovich Grigory Sery Ondrej Sharygina Natasha 《International Journal on Software Tools for Technology Transfer (STTT)》2017,19(5):517-534
International Journal on Software Tools for Technology Transfer - Software undergoes a myriad of minor changes along its lifecycle. Each evolved transformation of a program is expected to preserve... 相似文献
205.
The importance of lymphatic vessels in a myriad of human diseases is rapidly gaining recognition; lymphatic vessel dysfunction is a feature of disorders including congenital lymphatic anomalies, primary lymphoedema and obesity, while improved lymphatic vessel function increases the efficacy of immunotherapy for cancer and neurological disease and promotes cardiac repair following myocardial infarction. Understanding how the growth and function of lymphatic vessels is precisely regulated therefore stands to inform the development of novel therapeutics applicable to a wide range of human diseases. Lymphatic vascular development is initiated during embryogenesis following establishment of the major blood vessels and the onset of blood flow. Lymphatic endothelial progenitor cells arise from a combination of venous and non-venous sources to generate the initial lymphatic vascular structures in the vertebrate embryo, which are then further ramified and remodelled to elaborate an extensive lymphatic vascular network. Signalling mediated via vascular endothelial growth factor (VEGF) family members and vascular endothelial growth factor receptor (VEGFR) tyrosine kinases is crucial for development of both the blood and lymphatic vascular networks, though distinct components are utilised to different degrees in each vascular compartment. Although much is known about the regulation of VEGFA/VEGFR2 signalling in the blood vasculature, less is understood regarding the mechanisms by which VEGFC/VEGFD/VEGFR3 signalling is regulated during lymphatic vascular development. This review will focus on recent advances in our understanding of the cellular and molecular mechanisms regulating VEGFA-, VEGFC- and VEGFD-mediated signalling via VEGFRs which are important for driving the construction of lymphatic vessels during development and disease. 相似文献
206.
Basso Michael R.; Lowery Natasha; Neel Jackie; Purdie Rod; Bornstein Robert A. 《Canadian Metallurgical Quarterly》2002,16(1):84
Previous research has demonstrated broad neurobehavioral abnormalities in bipolar affective disorder (cf. G. Cassens, L. Wolfe, & M. Zola, 1990). However, there have been no comparisons of neuropsychological function across patients with manic, depressed, or mixed subtypes. In the present study, 37 manic, 24 mixed-episode, and 25 depressed bipolar I inpatients and 34 control subjects were administered a brief battery of neuropsychological tests. The multivariate and univariate effects of participant group on the neuropsychological measures were uniformly significant (p 相似文献
207.
Macklin Michael L.; Metzger Linda J.; Litz Brett T.; McNally Richard J.; Lasko Natasha B.; Orr Scott P.; Pitman Roger K. 《Canadian Metallurgical Quarterly》1998,66(2):323
The authors examined the relation between intelligence and posttraumatic stress disorder (PTSD) by studying the association among precombat intelligence, current intelligence, and self-reported PTSD symptoms. Military aptitude test results were obtained in 59 PTSD and 31 non-PTSD Vietnam combat veterans who had undergone a psychodiagnostic interview and current intelligence testing. People with lower precombat intelligence were more likely to develop PTSD symptoms as assessed by the Clinician-Administered PTSD Scale even after adjustment for extent of combat exposure. The association between current intelligence and PTSD was no longer significant after adjusting for precombat intelligence. These results suggest that lower pretrauma intelligence increases risk for developing PTSD symptoms, not that PTSD lowers performance on intelligence tests. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
208.
209.
Metzger Linda J.; Paige Stephen R.; Carson Margaret A.; Lasko Natasha B.; Paulus Lynn A.; Pitman Roger K.; Orr Scott P. 《Canadian Metallurgical Quarterly》2004,113(2):324
Researchers have proposed that depression and particular types of anxiety are associated with unique patterns of regional brain activation. The authors examined the relationship among posttraumatic stress disorder (PTSD), anxiety, and depressive symptoms and frontal, temporal, and parietal EEG alpha asymmetry in female Vietnam War nurse veterans. The results indicate that PTSD arousal symptoms are associated with increased right-sided parietal activation. However, the combination of arousal, depression, and their interaction explain more than twice the variance in parietal asymmetry compared with arousal alone. The results support the contention that the association between anxiety and right-sided posterior activation is specific to the anxious arousal subtype. These findings underscore the importance of isolating, both theoretically and statistically, emotional subcomponents in studies of regional brain activation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
210.
Ewa Tocha Holger Schönherr G. Julius Vancso Natasha Siebelt 《Journal of the American Ceramic Society》2005,88(9):2498-2503
The nanotribological properties of nanostructured thin films of tetragonal ZrO2 on oxidized Si (100) were studied as a function of grain size and relative humidity (RH) by atomic force microscopy. The nanostructured ZrO2 showed a 50% decrease in friction coefficient μ compared with oxidized Si (100) in dry nitrogen atmosphere and 40% RH. A maximum of μ was observed at ca. 40% RH for both samples, while there were insignificant differences in μ for ZrO2 samples with grain sizes between 12 and 30 nm. The good tribological properties open the possibility for nanostructured zirconia to be applied as wear-resistant, low friction coatings on various materials. 相似文献