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排序方式: 共有202条查询结果,搜索用时 15 毫秒
1.
2.
Delia V?rg? Petru Lucian Cur?eu Lauren?iu Maricu?oiu Florin A. Sava Irina Macsinga Silvia M?gurean 《PloS one》2014,9(11)
This study seeks to explore whether neuroticism, agreeableness, and conscientiousness moderate the influence of relationship conflict experienced in groups on changes in group members'' evaluative cognitions related to teamwork quality (teamwork-related mental models). Data from 216 students, nested in 48 groups were analyzed using a multilevel modeling approach. Our results show that the experience of relationship conflict leads to a negative shift from the pre-task to the post-task teamwork-related mental models. Moreover, the results indicate that conscientiousness buffered the negative association between relationship conflict and the change in teamwork-related mental models. Our results did not support the hypothesized moderating effect of agreeableness and show that the detrimental effect of relationship conflict on the shift in teamwork-related mental models is accentuated for group members scoring low rather than high on neuroticism. These findings open new research venues for exploring the association between personality, coping styles and change in teamwork-related mental models. 相似文献
3.
Lucian J. Cuprak Carol J. Lammi Janet I. Crane 《In vitro cellular & developmental biology. Plant》1979,15(11):900-909
Summary An improved basal medium is presented that requires only minimal supplementation with dialyzed fetal bovine serum or bovine
serum albumin and fetuin to be comparable to Ham's F-10, which requires 15% horse serum (HS) and 2.5% fetal bovine serum (FBS)
for the growth and function of Y-1, mouse adrenal cortex tumor, cells. Cell monolayers maintained for up to 2 weeks without
any protein supplementation have retained their steroid response to ACTH. The medium differs from Ham's F-10 in its buffer
composition and higher calcium-ion concentration. This medium should be a useful adjunct to studies pertaining to steroid
and lipid intermediary metabolism, the retention of a specialized physiological function in a chemically defined medium, and
the mechanism of hormonal response.
Supported by the Medical Research Service of the Veterans Administration. 相似文献
4.
C T Dragomir A Barbier D Ungureanu V Ionescu E Pausescu R Chirvasie D Ghitescu G Filipescu 《Physiological chemistry and physics》1975,7(4):287-308
Investigation of the ionic behavior of glycerinated muscle fibers showed that the residual structures of this biologic cellular material, lacking functional membranes, are able to discriminate between alkaline ions. The characteristics of the ionic selectivity of the glycerinated fibers change with their functional state and with the presence in the medium of certain nonionic substances. Among the more important features of ionic distribution between the membrane-free fibers and the medium are the following: (1) There is evident adsorption of potassium on the fibers, in the absence of ATP. (2) This adsorption increases in contraction and decreases in relaxation. (3) At high ionic concentrations, in contrast to what occurs at low potassium concentrations, the glycerinated muscle prefers sodium to potassium, but even under these conditions both ions are accumulated in the fibers to far greater levels than in the medium. This strongly suggests a Donnan ionic equilibrium developing parallel to the adsorption process. (4) Nonionic substances of the general anesthetic group markedly alter the ionic selectivity of the glycerinated fibers, probably by their action on the water's physical state. A mechanism is proposed for the observed ionic adsorption specific of the muscle-a mechanism in which actin-myosin coupling plays the cardinal adsorption role. In the general interpretation of the data a synthetic concept is advanced according to which an entire set of processes and factors concurs with the distribution of ions between the muscle and the medium. 相似文献
5.
Lucian Hritcu Marius Stefan Roderich Brandsch Marius Mihasan 《Journal of physiology and biochemistry》2013,69(1):25-34
Male Wistar rats were subjected to chronic 6-hydroxy-l-nicotine treatment (6HLN, 0.3 mg/kg, i.p., seven consecutive days) and their memory performance was studied by means of Y-maze and radial arm-maze tasks. 6HLN significantly increased spontaneous alternations in Y-maze task and working memory in radial arm-maze task, suggesting effects on short-term memory, without affecting long-term memory, explored by reference memory in radial arm-maze task. In addition, 6HLN increased antioxidant enzymes activity and decreased production of lipid peroxidation, suggesting antioxidant effects. Also, the linear regression between behavioral measures and oxidative stress markers resulted in significant correlations. Therefore, positive effects of 6HLN on spatial memory may occur by antioxidant actions. 相似文献
6.
7.
Wang Z Heshka S Wang J Wielopolski L Heymsfield SB 《American journal of physiology. Endocrinology and metabolism》2003,284(2):E267-E273
The mean density of fat-free mass (FFM) is remarkably stable at 1.10 g/cm(3) in healthy adult humans, and this stability is a cornerstone of the widely applied densitometry-based two-compartment model for estimating total body fat. At present, the usual means of exploring FFM density is by in vitro or in vivo experimental studies. The purpose of the present investigation was to develop a cellular-level body composition model that includes seven factors that determine FFM density. The model, when applied with available empirical coefficients, predicted an FFM density similar to that observed in vivo. An analysis of the seven model components indicates that the ratio of extracellular solids to total body water is a major determinant of individual variation in FFM density. The difference in FFM density across sex, race, and age groups was examined with the developed model. The present study thus provides a conceptual framework for the systematic study of FFM density in humans. 相似文献
8.
Christian Schobert Lucian Baker Judit Szederkényi Pia Großmann Ewald Komor Hiroaki Hayashi Mitsuo Chino William J. Lucas 《Planta》1998,206(2):245-252
The mature, functional sieve-tube system in higher plants is dependent upon protein import from the companion cells to maintain
a functional long-distance transport system. Soluble proteins present within the sieve-tube lumen were investigated by analysis
of sieve-tube exudates which revealed the presence of distinct sets of polypeptides in seven monocotyledonous and dicotyledonous
plant species. Antibodies directed against sieve-tube exudate proteins from Ricinus communis L. demonstrated the presence of shared antigens in the phloem sap collected from Triticum aestivum L., Oryza sativa L., Yucca filamentosa L., Cucurbita maxima Duch., Robinia pseudoacacia L. and Tilia platyphyllos L. Specific antibodies were employed to identify major polypeptides. Molecular chaperones related to Rubisco-subunit-binding
protein and cyclophilin, as well as ubiquitin and the redox proteins, thioredoxin h and glutaredoxin, were detected in the
sieve-tube exudate of all species examined. Actin and profilin, a modulator of actin polymerization, were also present in
all analyzed phloem exudates. However, some proteins were highly species-specific, e.g. cystatin, a protease-inhibitor was
present in R. communis but was not detected in exudates from other species, and orthologs of the well-known squash phloem lectin, phloem protein
2, were only identified in the sieve-tube exudate of R. communis and R. pseudoacacia. These findings are discussed in terms of the likely roles played by phloem proteins in the maintenance and function of the
enucleate sieve-tube system of higher plants.
Received: 12 February 1998 / Accepted: 16 March 1998 相似文献
9.
Shixin Yang Lucian Barbu-Tudoran Marek Orzechowski Roger Craig John Trinick Howard White William Lehman 《Biophysical journal》2014,106(4):855-864
Muscle contraction is regulated by troponin-tropomyosin, which blocks and unblocks myosin binding sites on actin. To elucidate this regulatory mechanism, the three-dimensional organization of troponin and tropomyosin on the thin filament must be determined. Although tropomyosin is well defined in electron microscopy helical reconstructions of thin filaments, troponin density is mostly lost. Here, we determined troponin organization on native relaxed cardiac muscle thin filaments by applying single particle reconstruction procedures to negatively stained specimens. Multiple reference models led to the same final structure, indicating absence of model bias in the procedure. The new reconstructions clearly showed F-actin, tropomyosin, and troponin densities. At the 25 Å resolution achieved, troponin was considerably better defined than in previous reconstructions. The troponin density closely resembled the shape of troponin crystallographic structures, facilitating detailed interpretation of the electron microscopy density map. The orientation of troponin-T and the troponin core domain established troponin polarity. Density attributable to the troponin-I mobile regulatory domain was positioned where it could hold tropomyosin in its blocking position on actin, thus suggesting the underlying structural basis of thin filament regulation. Our previous understanding of thin filament regulation had been limited to known movements of tropomyosin that sterically block and unblock myosin binding sites on actin. We now show how troponin, the Ca2+ sensor, may control these movements, ultimately determining whether muscle contracts or relaxes. 相似文献
10.
Leaf rust induced volatile organic compounds signalling in willow during the infection 总被引:1,自引:0,他引:1
Merje Toome Pille Randjärv Lucian Copolovici Ülo Niinemets Katrin Heinsoo Anne Luik Steffen M. Noe 《Planta》2010,232(1):235-243
Plants are known to emit volatile organic compounds (VOC) in response to various biotic or abiotic stresses. Although the
VOC emission in the case of insect attacks is well described, there is only little known about the impact of pathogens on
plant emission. In the present study, we used a willow-leaf rust system to describe the effects of a biotrophic fungal infection
on the VOC emission pattern of willow leaves. We detected that isoprene emissions from rust-infected leaves decreased threefold
compared to control. The total monoterpene emissions did not change although a stress-signalling compound (Z)-β-ocimene showed an increase in infected plants on several days. The infection also increased the emission of sesquiterpenes
and lipoxygenase products (LOX) by factors of 175-fold and 10-fold, respectively. The volatile emission signals showed two
clear peaks during the experiment. At 6, 7 and 12 days post-infection (dpi), the relative volatile emission signal increased
to about sixfold compared to uninfected plants. These time points are directly connected to rust infection since at 6 dpi
the first rust pustules appeared on the leaves and at 12 dpi necrosis had developed around several pustules. We present correlations
between LOX and sesquiterpene emission signals, which suggest at least two different steps in eliciting the volatile emission. 相似文献