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11.
Jelena Baranovic Chandra S. Ramanujan Nahoko Kasai Charles R. Midgett Dean R. Madden Keiichi Torimitsu John F. Ryan 《The Journal of biological chemistry》2013,288(12):8647-8657
AMPA receptors (AMPARs) are glutamate-gated ion channels ubiquitous in the vertebrate central nervous system, where they mediate fast excitatory neurotransmission and act as molecular determinants of memory formation and learning. Together with detailed analyses of individual AMPAR domains, structural studies of full-length AMPARs by electron microscopy and x-ray crystallography have provided important insights into channel assembly and function. However, the correlation between the structure and functional states of the channel remains ambiguous particularly because these functional states can be assessed only with the receptor bound within an intact lipid bilayer. To provide a basis for investigating AMPAR structure in a membrane environment, we developed an optimized reconstitution protocol using a receptor whose structure has previously been characterized by electron microscopy. Single-channel recordings of reconstituted homomeric GluA2flop receptors recapitulate key electrophysiological parameters of the channels expressed in native cellular membranes. Atomic force microscopy studies of the reconstituted samples provide high-resolution images of membrane-embedded full-length AMPARs at densities comparable to those in postsynaptic membranes. The data demonstrate the effect of protein density on conformational flexibility and dimensions of the receptors and provide the first structural characterization of functional membrane-embedded AMPARs, thus laying the foundation for correlated structure-function analyses of the predominant mediators of excitatory synaptic signals in the brain. 相似文献
12.
This study examined whether CX3CR1 deficiency altered monocytic cell replenishment dynamics in ocular tissues in the context of radiation chimeras. Long-term effects of irradiation and effects of sublethal irradiation on ocular macrophages were also assessed. Bone marrow from BALB/c Cx
3
cr1
+/gfp or Cx
3
cr1
gfp/gfp mice was used to reconstitute full body irradiated WT mice and donor cell densities in the uveal tract were compared at 4 and 8 weeks post-transplantation. BALB/c and C57BL/6J chimeric mice were examined at 6 months of age to determine strain-related differences in microglial replenishment and radiation sensitivity. A separate cohort of mice were sublethally irradiated (5.5 Gy) and retinal tissue assessed 8 and 12 weeks later. CX3CR1 deficiency altered the early replenishment of monocytes in the posterior iris but not in the iris stroma, choroid or retina. In six month old chimeric mice, there were significantly higher GFP+ cell densities in the uveal tract when compared to non-irradiated 8-12 week old Cx
3
cr1
+/gfp mice. Additionally, MHC Class II expression was upregulated on hyalocytes and GFP+ cells in the peripheral retina and the repopulation of microglia appeared to be more rapid in C57BL/6J mice compared to BALB/c mice. Transient expression of MHC Class II was observed on retinal vasculature in sublethally irradiated mice. These data indicate CX3CR1-deficiency only slightly alters monocyte-derived cell replenishment in the murine uveal tract. Lethal irradiation leads to long-term increase in monocytic cell density in the uveal tract and retinal microglial activation, possibly as a sequelae to local irradiation induced injury. Microglial replenishment in this model appears to be strain dependent. 相似文献
13.
14.
Natasa M. Milic Goran Z. Trajkovic Zoran M. Bukumiric Andja Cirkovic Ivan M. Nikolic Jelena S. Milin Nikola V. Milic Marko D. Savic Aleksandar M. Corac Jelena M. Marinkovic Dejana M. Stanisavljevic 《PloS one》2016,11(2)
Background
Although recent studies report on the benefits of blended learning in improving medical student education, there is still no empirical evidence on the relative effectiveness of blended over traditional learning approaches in medical statistics. We implemented blended along with on-site (i.e. face-to-face) learning to further assess the potential value of web-based learning in medical statistics.Methods
This was a prospective study conducted with third year medical undergraduate students attending the Faculty of Medicine, University of Belgrade, who passed (440 of 545) the final exam of the obligatory introductory statistics course during 2013–14. Student statistics achievements were stratified based on the two methods of education delivery: blended learning and on-site learning. Blended learning included a combination of face-to-face and distance learning methodologies integrated into a single course.Results
Mean exam scores for the blended learning student group were higher than for the on-site student group for both final statistics score (89.36±6.60 vs. 86.06±8.48; p = 0.001) and knowledge test score (7.88±1.30 vs. 7.51±1.36; p = 0.023) with a medium effect size. There were no differences in sex or study duration between the groups. Current grade point average (GPA) was higher in the blended group. In a multivariable regression model, current GPA and knowledge test scores were associated with the final statistics score after adjusting for study duration and learning modality (p<0.001).Conclusion
This study provides empirical evidence to support educator decisions to implement different learning environments for teaching medical statistics to undergraduate medical students. Blended and on-site training formats led to similar knowledge acquisition; however, students with higher GPA preferred the technology assisted learning format. Implementation of blended learning approaches can be considered an attractive, cost-effective, and efficient alternative to traditional classroom training in medical statistics. 相似文献15.
Anmol Kumar Jaakko Kopra K?rt Varendi Lauriina L. Porokuokka Anne Panhelainen Satu Kuure Pepin Marshall Nina Karalija Mari-Anne H?rma Carolina Vilenius Kersti Lillev?li Triin Tekko Jelena Mijatovic Nita Pulkkinen Madis Jakobson Maili Jakobson Roxana Ola Erik Palm Maria Lindahl Ingrid Str?mberg Vootele V?ikar T. Petteri Piepponen Mart Saarma Jaan-Olle Andressoo 《PLoS genetics》2016,12(1)
16.
Hydrobiologia - Catchment-scale variation between lake habitats has the potential to simultaneously influence the trophic niche and parasite community of fish hosts. In this study, we investigated... 相似文献
17.
Dakic Tamara Jevdjovic Tanja Lakic Iva Djurasevic Sinisa F. Djordjevic Jelena Vujovic Predrag 《Neurochemical research》2019,44(2):388-399
Neurochemical Research - Our group previously reported that 6-h fasting increased both insulin II mRNA expression and insulin level in rat hypothalamus. Given that insulin effects on central... 相似文献
18.
Marijana Vučinić Ivana Hajzler Jelena Terzin Katarina Nenadović Ljiljana Janković Eva Voslarova 《Anthrozo?s》2019,32(1):129-139
The objective of the research was to determine the profile of reptile owners (n = 238) in terms of their socio-demographic characteristics and evaluations of veterinarians’ expertise. Reptile owners living in four non-EU Balkan countries (Bosnia and Herzegovina, Macedonia, Montenegro, and Serbia) were randomly selected from two social networks. Statistically significant differences were found in snake, lizard, and turtle owners (p < 0.05) in terms of gender, employment status, and monthly earnings. Male owners of reptiles were slightly more numerous (52%) compared with female owners (48%). Sixty-four percent of reptile owners were over 20 years old. The unemployed reptile owners (16%) were about five times fewer in number compared with those who studied at university and those who were employed. Forty-one percent of reptile owners declared high monthly incomes. Forty percent of reptile owners never contacted and had no experience with veterinarians. Fifty-eight percent of reptile owners contacted or visited veterinarians due to the medical condition of their animals, 14% of them contacted veterinarians for advice on reptile keeping, and only 6% did so for a preventive veterinary examination. Forty-seven percent of reptile owners were satisfied with veterinary services. The importance of the results of this survey is that they can provide a basis for adopting legislation on the ownership of reptiles as pet animals, together with being a baseline for monitoring subsequent changes in interest in these animals as pets. The results also identify the need for more dedication from veterinarians in educating reptile owners, and for necessary adjustments in veterinary education. 相似文献
19.
Cateni F Zilic J Falsone G Scialino G Banfi E 《Bioorganic & medicinal chemistry letters》2003,13(24):4345-4350
The less polar fraction of the methanolic extract from the plant Euphorbia peplis L. exhibited interesting antifungal and antitubercular activity. A complex mixture of four glucocerebrosides was responsible for this activity. Two new cerebrosides were isolated for the first time from Euphorbiaceae, 4 was assigned as 1-O-(beta-D-glucopyranosyl)-(2S,3S,4E,8E)-2N-[(2'R)-2'-hydroxy-hexadecanoyl]-4 (E), 8 (E)-octadecadiene-1,3-diol and 3 as the 1-O-(beta-D-glucopyranosyl)-(2S,3S,4R,8Z)-2N-[(2'R)-2'-hydroxytetracosanoyl]-8 (Z)-octadecene-1,3,4-triol. The structures were determined on the basis of chemical and spectroscopic evidences. Mass spectrometry of dimethyl disulfide derivatives was useful for the determination of the double-bond positions in the long-chain bases. 相似文献
20.
Raspor Martin Motyka Václav Ninković Slavica Malbeck Jiří Dobrev Petre I. Zdravković-Korać Snežana Simonović Ana Ćosić Tatjana Cingel Aleksandar Savić Jelena Zahajská Lenka Tadić Vojin Dragićević Ivana Č. 《Journal of Plant Growth Regulation》2021,40(1):37-47
Journal of Plant Growth Regulation - Over the last years, cytokinin deficiency has been studied in a variety of plant species, using transgenic expression of cytokinin oxidase/dehydrogenase genes... 相似文献