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981.
Biological changes occurring as a consequence of domestication and/or captivity are not still deeply known. In Atlantic salmon (Salmo salar), endangered (Southern Europe) populations are enhanced by supportive breeding, which involves only 6 months of captive rearing following artificial spawning of wild‐collected adults. In this work, we assess whether several fitness‐correlated life‐history traits (migratory behavior, straying rate, age at maturity, and growth) are affected by early exposure to the captive environment within a generation, before reproduction thus before genetic selection. Results showed significant differences in growth and migratory behavior (including straying), associated with this very short period of captivity in natural fish populations, changing even genetic variability (decreased in hatchery‐reared adults) and the native population structure within and between rivers of the species. These changes appeared within a single generation, suggesting very short time of captivity is enough for initiating changes normally attributed to domestication. These results may have potential implications for the long‐term population stability/viability of species subjected to restoration and enhancement processes and could be also considered for the management of zoo populations.  相似文献   
982.
983.
984.
Epithelia and endothelia delineate tissue compartments and control their environments by regulating the passage of ions and solutes. This barrier function is essential for the development and maintenance of multicellular organisms, and its dysfunction is associated with numerous human diseases. Recent advances in biomaterials and microfabrication technologies have evolved in vitro approaches for modelling biological barriers. Current microphysiological systems have become more efficient and reliable in mimicking the cell microenvironment. Additionally, methods for the quantification of barrier permeability have long provided significant insight into their underlying mechanisms. In this review, we outline the current techniques to quantify the barrier function of engineered tissues, and we also give an overview of recent microphysiological systems of biological barriers that emulate the microenvironment and microarchitecture of native tissues.  相似文献   
985.
Quantification of the intracellular equilibrium dissociation constant of the interaction, Kd, is challenging due to the variability of the relative concentrations of the interacting proteins in the cell. Fluorescence lifetime imaging microscopy (FLIM) of the donor provides an accurate measurement of the molecular fraction of donor involved in FRET, but the fraction of bound acceptor is also needed to reliably estimate Kd. We present a method that exploits the spectroscopic properties of the widely used eGFP – mCherry FRET pair to rigorously determine the intracellular Kd based on imaging the fluorescence lifetime of only the donor (single‐channel FLIM). We have assessed the effect of incomplete labelling and determined its range of application for different Kd using Monte Carlo simulations. We have demonstrated this method estimating the intracellular Kd for the homodimerisaton of the oncogenic protein 3‐phosphoinositide‐dependent kinase 1 (PDK1) in different cell lines and conditions, revealing a competitive mechanism for its regulation. The measured intracellular Kd was validated against in‐vitro data. This method provides an accurate and generic tool to quantify protein interactions in situ.

  相似文献   

986.
When an alternative fuel is introduced, the infrastructure through which that fuel is made available to the market is often underdeveloped. Transportation service providers relying on such infrastructures are unlikely to adopt alternative fuel vehicles as it may impose long detours for refueling. In this paper, we design and apply a new solution approach to derive minimum infrastructure requirements, in terms of the number of alternative fuel stations. The effectiveness of our approach is demonstrated by applying it to the case of introducing liquefied natural gas (LNG) as a transportation fuel in The Netherlands. From this case, we learn that, depending on the driving range of the LNG trucks and the size of area on which those trucks operate, a minimum of 5–12 LNG fuel stations is necessary to render LNG trucks economically and environmentally beneficial.  相似文献   
987.

Objective

Electronegative LDL (LDL(?)) is involved in atherosclerosis through the activation of the TLR4/CD14 inflammatory pathway in monocytes. Matrix metalloproteinases (MMP) and their inhibitors (tissue inhibitors of metalloproteinase [TIMP]) are also crucially involved in atherosclerosis, but their modulation by LDL(?) has never been investigated. The aim of this study was to examine the ability of LDL(?) to release MMPs and TIMPs in human monocytes and to determine whether sulodexide (SDX), a glycosaminoglycan-based drug, was able to affect their secretion.

Approach and results

Native LDL (LDL(+)) and LDL(?) separated by anion-exchange chromatography were added to THP1-CD14 monocytes in the presence or absence of SDX for 24?h. A panel of 9 MMPs and 4 TIMPs was analyzed in cell supernatants with multiplex immunoassays. The gelatinolytic activity of MMP-9 was assessed by gelatin zymography. LDL(?) stimulated the release of MMP-9 (13-fold) and TIMP-1 (4-fold) in THP1-CD14 monocytes, as well as the gelatinolytic activity of MMP-9. Co-incubation of monocytes with LDL(?) and SDX for 24?h significantly reduced both the release of MMP-9 and TIMP-1 and gelatinase activity. In THP1 cells not expressing CD14, no effect of LDL(?) on MMP-9 or TIMP-1 release was observed. The uptake of DiI-labeled LDL(?) was higher than that of DiI-LDL(+) in THP1-CD14 but not in THP1 cells. This increase was inhibited by SDX. Experiments in microtiter wells coated with SDX demonstrated a specific interaction of LDL(?) with SDX.

Conclusions

LDL(?) induced the release of MMP-9 and TIMP-1 in monocytes through CD14. SDX affects the ability of LDL(?) to promote TIMP-1 and MMP-9 release by its interaction with LDL(?).  相似文献   
988.
989.
Cytochrome P450 1A1 CYP1A1 enzymatic activity was evaluated in cultured liver cells, and taken as a biological indicator of the presence of inducers of this isoform in urban airborne particulate matter fraction samples. It is known that CYP1A1 inducers can play an important role in the risk of mutagenesis and carcinogenesis by environmental pollution. A romatic polycyclic hydrocarbons PAH from urban air were collected in the city of Genoa Italy at two sites on two different days of the year. The objective of the study was to compare the inducibility of cultured rat hepatocytes with that of MH1C1 and FaO rat hepatoma cell lines after exposure to a PAH mixture and to a standard compound, such as benzo b fluoranthene B b F . Cytotoxic effects of the tested concentrations were evaluated by means of 3 4,5, dimenthylthyazol 2 yl 2,5 diphenyltetrazolium bromide MTT and lactate dehydrogenase release LDH tests, the potency of inducers by ethoxyresorufin O deethylase EROD assay. The results were in agreement in the three cellular systems: after exposure to the PAH mixture, an induction at low concentrations was observed; whereas no induction, but rather a decrease in activity was shown at higher concentrations; instead, the exposure to pure B b F showed a dose-response relationship in all cells, even at the highest doses. Such a difference between the toxicity of the complex mixture and that of the pure compound could be ascribed to the presence of drug metabolism inhibitors in the mixture, or to interactions between the original components and their metabolites. The finding that the cell lines responded to the CYP1A1 induction in a very efficient way gives further proof of the applicability of this system to environmental biomonitoring.  相似文献   
990.
Respiratory responses of Pseudodiaptomus hessei measured underdifferent conditions show an exponential increase in metabolicrate with temperature, but no changes with salinity. All metabolicdemands of this species are met through consumption of microalgaeduring the closed (winter) phase, but not during the open (summer)phase of the estuary.  相似文献   
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