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排序方式: 共有237条查询结果,搜索用时 31 毫秒
1.
Event-related potentials (ERPs) to visual stimuli were recorded from the scalp of eight adult humans performing a task in which they counted vowels from a heard story. In the oddball condition, a repeated (standard) light bar of 50 ms in duration was rarely (P = 0.1) replaced by a (deviant) one differing in orientation from the standard. In the control condition, standards were simply omitted from the series and only (alone-) deviants retained. In both conditions, visual stimuli were asynchronous with auditory-task-relevant stimuli. ERPs to deviants significantly differed in amplitude from those to standards in the midline electrodes centrally, parietally and occipitally at 160-200 ms from stimulus onset. Occipitally, such a difference was absent between ERPs to alone-deviants and those to standards. The occipital differential ERPs to deviants, which thus could be found only when standards were present in the series, are discussed in the context of the mismatch negativity (MMN). 相似文献
2.
Kaikkonen H Yrjämä M Siljander E Byman P Laukkanen R 《Scandinavian journal of medicine & science in sports》2000,10(4):211-215
The effects of a 12-week low resistance circuit weight training (CWT) on cardiovascular and muscular fitness were studied in 90 healthy sedentary adults. The subjects were randomized into three equally fit groups: CWT, Endurance (END) and Control (CON) according to their maximal aerobic power (VO2max). Both training groups exercised for 12 weeks, 3 days a week in sessions of 40 min, with a heart rate (HR) level of 70-80% HRmax. The CWT group trained with air resistance machines. Heart rate was controlled by setting the speed of movement. The END group walked, jogged, cross-country skied or cycled. The net differences (between pre- and posttraining changes) between the CWT and CON groups was statistically significant for VO2max (2.45 ml x min(-1) x kg(-1), 95% CI 1.1; 3.8), for abdominal muscles (3.7 reps, CI 0.3; 7.1), for push-ups (1.1 reps, CI 0.2; 2.1), and for kneeling (2.25 reps, CI 0.01; 4.5). The net difference (between pre- and posttraining changes) in the END and CON groups was statistically significant for VO2max (2.75 ml(-1) x min(-1) x kg(-1), 95% CI 0.9; 4.6), and kneeling (3.0 reps, CI 0.7; 5.3). Low resistance CWT with moderately hard HR level has effects comparable to an equal amount of endurance training on the cardiovascular fitness of sedentary adults. The CWT model was benefical also on muscular fitness. Based on the results, this type of exercise can be recommended for beginners because of its multilevel effects. 相似文献
3.
Kaija Komulainen DDS Pekka Ylöstalo DDS PhD Anna‐Maija Syrjälä DDS PhD Piia Ruoppi DDS Matti Knuuttila DDS PhD Raimo Sulkava MD PhD Sirpa Hartikainen MD PhD 《Special care in dentistry》2014,34(1):19-26
The aim was to study the determinants of preventive oral health care need among community‐dwelling old people. The study population consisted of 165 participants, a subpopulation in the Geriatric Multidisciplinary Strategy for Good Care of Elderly People (GeMS) study. Fifty‐five percent of the edentate participants with full dentures and 82% of the dentate had a need for preventive oral health care. In the total study population, the need for preventive care was associated with co‐morbidity (measured by means of the Modified Functional Co‐morbidity Index) odds ratios (OR) 1.2 (confidence intervals [CI] 1.0–1.5), being pre‐frail or frail, OR 2.5 (CI 1.2–5.1), presence of natural teeth, OR 4.8 (CI 2.2–10.4), and among dentate participants, the use of a removable partial denture, OR 12.8 (CI 1.4–114.4). Primary care clinicians should be aware of the high need for preventive care and the importance of nonoral conditions as determinants of preventive oral health care need. 相似文献
4.
OBJECTIVE: Hematopoietic stem cells are important clinically, both as targets of disease and as reagents for cellular therapy. Studies in hematopoietic stem cell biology have been hampered by difficulties in purifying and manipulating these cells. To facilitate these studies, we sought to develop a system for targeting genes of interest to the hematopoietic stem cell compartment in transgenic mice. MATERIALS AND METHODS: We used Sca-1, a glycosyl phosphatidylinositol-anchored protein expressed on the surface of all hematopoietic stem cells in commonly used inbred mouse strains. We created a mutant Sca-1 allele in which the enhanced green fluorescent protein (EGFP) cDNA is integrated into the Sca-1 locus by homologous recombination in embryonic stem cells. RESULTS: EGFP protein is detectable in all hematopoietic tissues of mice heterozygous for the mutant Sca-1 allele. Growth and development of these mice are normal. No adverse effects of long-term, high-level EGFP expression were noted. Sca-1 positive cells coexpress EGFP in all tissues and lineages examined, as predicted by the targeting strategy. Sca-1 and EGFP expression are coordinately up-regulated in splenocytes from mutant mice. The Lin(-)EGFP(+) bone marrow population contains all progenitor activity in Sca-1(+)(/EGFP) mice. The Lin(-)EGFP(+) bone marrow cells are equivalent to Lin(-)Sca-1(+) cells in long-term repopulation and serial transplantation assays. CONCLUSION: The hematopoietic stem cell compartment appears to be targeted in Sca-1(+)(/EGFP) mutant mice. This system should be useful for studying the normal biology of hematopoietic stem cells and for targeting other genes to this cellular compartment. 相似文献
5.
Does contextual affective information influence the processing of facial expressions already at the relatively early stages of face processing? We measured event-related brain potentials to happy and sad facial expressions primed by preceding pictures with affectively positive and negative scenes. The face-sensitive N170 response amplitudes showed a clear affective priming effect: N170 amplitudes to happy faces were larger when presented after positive vs. negative primes, whereas the N170 amplitudes to sad faces were larger when presented after negative vs. positive primes. Priming effects were also observed on later brain responses. The results support an early integration in processing of contextual and facial affective information. The results also provide neurophysiological support for theories suggesting that behavioral affective priming effects are based, at least in part, on facilitation of encoding of incoming affective information. 相似文献
6.
Accumulating evidence indicates that childhood nutrition plays a role in the adulthood cardiovascular health. A lifelong tracking of dietary habits, following a long-term exposure to unhealthy dietary patterns or independent effects, is a potential effect-mediating mechanism. Dietary patterns have been studied by data-driven and hypothesis-based approaches. Typically, either data-driven healthy or prudent childhood dietary patterns have been characterized and found to be associated with lower adulthood cardiovascular disease (CVD) risk in the published cohort studies. With regard to the individual food groups or food quality indices, intakes particularly of vegetables and fruits (or fiber indicating plant food intake) and polyunsaturated fatty acids have shown protective effects. The evidence which could confirm the long-term healthiness of a hypothesis-based Mediterranean diet is limited, requiring further investigation. Overall, the recent literature strengthens the view that a healthy childhood diet is associated with lowered adulthood CVD risk. 相似文献
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Loss of Gsα Early in the Osteoblast Lineage Favors Adipogenic Differentiation of Mesenchymal Progenitors and Committed Osteoblast Precursors 下载免费PDF全文
Partha Sinha Piia Aarnisalo Rhiannon Chubb Noriaki Ono Keertik Fulzele Martin Selig Hamid Saeed Min Chen Lee S Weinstein Paola Divieti Pajevic Henry M Kronenberg Joy Y Wu 《Journal of bone and mineral research》2014,29(11):2414-2426
In humans, aging and glucocorticoid treatment are associated with reduced bone mass and increased marrow adiposity, suggesting that the differentiation of osteoblasts and adipocytes may be coordinately regulated. Within the bone marrow, both osteoblasts and adipocytes are derived from mesenchymal progenitor cells, but the mechanisms guiding the commitment of mesenchymal progenitors into osteoblast versus adipocyte lineages are not fully defined. The heterotrimeric G protein subunit Gsα activates protein kinase A signaling downstream of several G protein‐coupled receptors including the parathyroid hormone receptor, and plays a crucial role in regulating bone mass. Here, we show that targeted ablation of Gsα in early osteoblast precursors, but not in differentiated osteocytes, results in a dramatic increase in bone marrow adipocytes. Mutant mice have reduced numbers of mesenchymal progenitors overall, with an increase in the proportion of progenitors committed to the adipocyte lineage. Furthermore, cells committed to the osteoblast lineage retain adipogenic potential both in vitro and in vivo. These findings have clinical implications for developing therapeutic approaches to direct the commitment of mesenchymal progenitors into the osteoblast lineage. © 2014 American Society for Bone and Mineral Research 相似文献
10.
Piia Jul Tran T. Ho Urve Kallavus Alar Konist Kristiina Leiman Olivia-Stella Salm Maria Kulp Mihkel Koel Tiit Lukk 《Materials》2022,15(8)
The production of novel materials and value-added chemicals from lignin has received considerable attention in recent years. Due to its abundant occurrence in nature, there is a growing interest in utilizing lignin as a feedstock for functional materials production, for example aerogels. Much like in the synthesis of phenol-based resins, the vacant ortho positions of the aromatic rings in lignin can crosslink with formaldehyde and form polymeric gels. After drying the hydrogels with supercritical CO2, highly porous aerogels are obtained. Current study focuses on the preparation and thorough parametrization of organosolv lignins from different types of lignocellulosic biomass (aspen, pine, and barley straw) as well as their utilization for the preparation of lignin-5-methylresorcinol-formaldehyde aerogels. The thorough structural characterization of the obtained aerogels was carried out by gas adsorption, IR spectroscopy, and scanning electron microscopy. The obtained lignin-based monolithic mesoporous aerogels had specific surface areas and total pore volumes in the upward ranges of 450 m2/g and 1.4 cm3/g, respectively. 相似文献