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11.
Little is known of the patterns of physical activity, standing and sitting byoffice workers. However, insight into these behaviours is of growing interest,notably in regard to public health priorities to reduce non-communicable diseaserisk factors associated with high levels of sitting time and low levels ofphysical activity. With the advent and increasing availability of indoortracking systems it is now becoming possible to build detailed pictures of theusage of indoor spaces. This paper reports initial results of indoor trackingused in conjunction with the ActivPAL activity monitoring device. In this paperwe give an overview of the usage of the tracking system and its installation andillustrate some of the resultant data. We also provide preliminary results thatinvestigate the relationship between location, light physical activity andsitting in a small sample of office workers (n=33) from two separate officeenvironments in order to demonstrate the relevance and explanatory power of thetechnique.  相似文献   
12.
We have synthesized a series of new (E) stilbenoid derivatives containing hydroxy groups at ring positions identical or similar to those of trans-resveratrol and bearing one or two bulky electron donating groups ortho to 4′-OH and we have evaluated their neuroprotective activity using glutamate-challenged HT22 hippocampal neurons to model oxidative stress-induced neuronal cell death. The most active derivatives, 5-{(E)-2-[3,5-bis(1-ethylpropyl)-4-hydroxyphenyl]ethenyl}-1,3-benzenediol (2), 5-[(E)-2-(3,5-di-tert-butyl-4-hydroxyphenylethenyl)]-1,3-benzenediol (4) and 5-{(1E,3E)-4-[3,5-bis(1-ethylpropyl)-4-hydroxyphenyl]-1,3-butadienyl}-1,3-benzenediol (6), had EC50 values of 30, 45 and 12 nM, respectively, and were ca. 100 to 400-fold more potent than resveratrol. Derivatives 2, 4 and 6 lacked cytotoxic activity against HT22 cells and estrogen receptor agonist or antagonist activity in estrogen response element-dependent gene expression and in estrogen-dependent proliferation of MCF-7 human breast cancer cells. In addition, they were incapable of interfering with aryl hydrocarbon receptor-mediated xenobiotic response element-dependent gene expression. Derivatives 2, 4 and 6 might assist in the development of lead candidates against oxidative stress-driven neurodegenerative diseases that will not increase endocrine cancer risk nor affect drug activation and detoxification mechanisms.  相似文献   
13.
It has been reported that beta amyloid induces production of radical oxygen species and oxidative stress in neuronal cells, which in turn upregulates β-secretase (BACE-1) expression and beta amyloid levels, thereby propagating oxidative stress and increasing neuronal injury. A series of resveratrol derivatives, known to be inhibitors of oxidative stress-induced neuronal cell death (oxytosis) were biologically evaluated against BACE-1 using homogeneous time-resolved fluorescence (TRF) assay. Correlation between oxytosis inhibitory and BACE-1 inhibitory activity of resveratrol derivatives was statistically significant, supporting the notion that BACE-1 may act as pivotal mediator of neuronal cell oxytosis. Four of the biologically evaluated resveratrol analogs demonstrated considerably higher activity than resveratrol in either assay. The discovery of some “hits” led us to initiate detailed docking studies associated with Molecular Dynamics in order to provide a plausible explanation for the experimental results and understand their molecular basis of action.  相似文献   
14.
Immunity in tomato (Solanum lycopersicum) to Pseudomonas syringae bacteria expressing the effector proteins AvrPto and AvrPtoB requires both Pto kinase and the NBARC-LRR (for nucleotide binding domain shared by Apaf-1, certain R gene products, and CED-4 fused to C-terminal leucine-rich repeats) protein Prf. Pto plays a direct role in effector recognition within the host cytoplasm, but the role of Prf is unknown. We show that Pto and Prf are coincident in the signal transduction pathway that controls ligand-independent signaling. Pto and Prf associate in a coregulatory interaction that requires Pto kinase activity and N-myristoylation for signaling. Pto interacts with a unique Prf N-terminal domain outside of the NBARC-LRR domain and resides in a high molecular weight recognition complex dependent on the presence of Prf. In this complex, both Pto and Prf contribute to specific recognition of AvrPtoB. The data suggest that the role of Pto is confined to the regulation of Prf and that the bacterial effectors have evolved to target this coregulatory molecular switch.  相似文献   
15.
Novel 1,2-dithiolane/chroman hybrids bearing heterocyclic rings such as 1,2,4- and 1,3,4-oxadiazole, 1,2,3-triazole and tetrazole were designed and synthesized. The neuroprotective activity of the new analogues was tested against oxidative stress-induced cell death of glutamate-challenged HT22 hippocampal neurons. Our results show that bioisosteric replacement of amide group in 2-position of the chroman moiety, by 1,3,4-oxadiazole did not affect activity. However, analogue 5 bearing the 1,2,4-oxadiazole moiety showed improved neuroprotective activity. The presence of nitrogen heterocycles strongly influences the neuroprotective activity of 5-substituted chroman derivatives, depending on the nature of heterocycle. Replacement of the amide group of the first generation analogues by 1,2,4-oxadiazole or 1,2,3-triazole resulted in significant improvement of the activity against glutamate induced oxidative stress.  相似文献   
16.
The aims of this study were to determine 1) whether ventilatory adaptation occurred over a 5-day exposure to a constant elevation in end-tidal PCO2 and 2) whether such an exposure altered the sensitivity of the chemoreflexes to acute hypoxia and hypercapnia. Ten healthy human subjects were studied over a period of 13 days. Their ventilation, chemoreflex sensitivities, and acid-base status were measured daily before, during, and after 5 days of elevated end-tidal PCO2 at 8 Torr above normal. There was no major adaptation of ventilation during the 5 days of hypercapnic exposure. There was an increase in ventilatory chemosensitivity to acute hypoxia (from 1.35 +/- 0.08 to 1.70 +/- 0.07 l/min/%; P < 0.01) but no change in ventilatory chemosensitivity to acute hypercapnia. There was a degree of compensatory metabolic alkalosis. The results do not support the hypothesis that the ventilatory adaptation to chronic hypercapnia would be much greater with constant elevation of alveolar PCO2 than with constant elevation of inspired PCO2, as has been used in previous studies and in which the feedback loop between ventilation and alveolar PCO2 is left intact.  相似文献   
17.
Through an unusual differentiation process, human trophoblast progenitors (cytotrophoblasts) give rise to tumor-like cells that invade the uterus. By an unknown mechanism, invasive cytotrophoblasts exhibit permanent cell cycle withdrawal. Here, we report molecular cytogenetic data showing that approximately 20 to 60% of these interphase cells had acquired aneusomies involving chromosomes X, Y, or 16. The incidence positively correlated with gestational age and differentiation to an invasive phenotype. Scoring 12 chromosomes in flow-sorted cytotrophoblasts showed that more than 95% of the cells were hyperdiploid. Thus, aneuploidy appears to be an important component of normal placentation, perhaps limiting the proliferative and invasive potential of cytotrophoblasts within the uterus.  相似文献   
18.
ClC-4 is a secondary active transporter that exchanges Cl ions and H+ with a 2:1 stoichiometry. In external SCN, ClC-4 becomes uncoupled and transports anions with high unitary transport rate. Upon voltage steps, the number of active transporters varies in a time-dependent manner, resembling voltage-dependent gating of ion channels. We here investigated modification of the voltage dependence of uncoupled ClC-4 by protons and anions to quantify association of substrates with the transporter. External acidification shifts voltage dependence of ClC-4 transport to more positive potentials and leads to reduced transport currents. Internal pH changes had less pronounced effects. Uncoupled ClC-4 transport is facilitated by elevated external [SCN] but impaired by internal Cl and I. Block by internal anions indicates the existence of an internal anion-binding site with high affinity that is not present in ClC channels. The voltage dependence of ClC-4 coupled transport is modulated by external protons and internal Cl in a manner similar to what is observed under uncoupling conditions. Our data illustrate functional differences but also similarities between ClC channels and transporters.  相似文献   
19.
So far inferences on early moral development and higher order self conscious emotions have mostly been based on behavioral data. Emotions though, as far as arguments support, are multidimensional notions. Not only do they involve behavioral actions upon perception of an event, but they also carry autonomic physiological markers. The current study aimed to examine and characterise physiological signs that underlie self-conscious emotions in early childhood, while grounding them on behavioral analyses. For this purpose, the “mishap paradigm” was used as the most reliable method for evoking feelings of “guilt” in children and autonomic facial temperature variation were detected by functional Infrared Imaging (fIRI). Fifteen children (age: 39–42 months) participated in the study. They were asked to play with a toy, falsely informed that it was the experimenter''s “favourite”, while being unaware that it was pre-planned to break. Mishap of the toy during engagement caused sympathetic arousal as shown by peripheral nasal vasoconstriction leading to a marked temperature drop, compared to baseline. Soothing after the mishap phase induced an increase in nose temperature, associated with parasympathetic activity suggesting that the child''s distress was neutralized, or even overcompensated. Behavioral analyses reported signs of distress evoked by the paradigm, backing up the thermal observation. The results suggest that the integration of physiological elements should be crucial in research concerning socio-emotional development. fIRI is a non invasive and non contact method providing a powerful tool for inferring early moral emotional signs based on physiological observations of peripheral vasoconstriction, while preserving an ecological and natural context.  相似文献   
20.
The analysis of the anatomical characteristics of tree rings of the Pinus sibirica scions and Pinus sylvestris rootstocks is presented. The main anatomical features maintain the seasonal dynamics characteristic of the reference (ungrafted) trees of scion and rootstock, pointing to the stability of the genetic control of the xylem differentiation. However, various anatomical characteristics are reduced for rootstocks and increased for scions relative to the reference trees. A mechanism consistent with our results is that the graft union zone creates a barrier for the ascending and descending transport of substances, including phytohormones. The reaction of the scion and rootstock to climatic factors is weakened relative to the reaction of the reference trees. Thus, the presumed shift towards phytohormone disbalance reduces the influence of external factors on xylem differentiation. The interannual variation of the individual characteristics of the scions and rootstocks is increased relative to the reference trees, reflecting either the influence of the graft partners on each other or the non-uniform distribution of the growth regulators across the graft union. Thus, heterografts can be used to evaluate the interaction of the internal and external mechanisms of xylem differentiation.  相似文献   
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