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Summary Oligosaccharides were synthesized through the enzymatic condensation of D-glucose by glucoamylase in water-organic mixtures with high concentrations of two of diethylene glycol diethyl ether or triethylene glycol dimethyl ether. The effect of water content on the yield of reaction was studied; maximum yield was obtained with 10% (v/v) of water in the two systems. Kinetics of synthesis and products composition were different with the two solvents. 37% of glucose were condensed by action of glucoamylase from a reaction medium containing 20 g/L of glucose and 90% (v/v) of diethylene glycol diethyl ether. 相似文献
924.
María José Arauz Valéry Ridde Libia Milena Hernández Yaneth Charris Mabel Carabali Luis ángel Villar 《PloS one》2015,10(2)
BackgroundDengue fever is a public health problem in the tropical and sub-tropical world. Dengue cases have grown dramatically in recent years as well as dengue mortality. Colombia has experienced periodic dengue outbreaks with numerous dengue related-deaths, where the Santander department has been particularly affected. Although social determinants of health (SDH) shape health outcomes, including mortality, it is not yet understood how these affect dengue mortality. The aim of this pilot study was to develop and pre-test a social autopsy (SA) tool for dengue mortality.ConclusionsThe SA tool is based on the scientific literature, a validated conceptual framework, researchers’ and health professionals’ expertise, and a pilot study. It is the first time that a SA tool has been created for the dengue mortality context. Our work furthers the study on SDH and how these are applied to neglected tropical diseases, like dengue. This tool could be integrated in surveillance systems to provide complementary information on the modifiable and avoidable death-related factors and therefore, be able to formulate interventions for dengue mortality reduction. 相似文献
925.
Daniela Giordano Roberta Russo Daniela Coppola Giovanna Altomonte Guido di Prisco Stefano Bruno Cinzia Verde 《Hydrobiologia》2015,761(1):293-312
Notothenioidei, the taxonomic group of teleosts that dominates the Southern Ocean and dwell in the Ross Sea at large, provide an example of marine species that underwent unique adaptations to life at low temperatures and high oxygen concentrations, resulting in morphological, physiological, genomic, and biochemical peculiarities in comparison with warm-water fish. Global Warming raises concerns over the fate of these stenothermal fish, as their adaptation has been accompanied by irreversible genomic losses, which suggest a poor genetic potential to adapt to warmer climates. Specifically, this review focuses on adaptation of proteins belonging to the globin superfamily, which include the respiratory proteins hemoglobin and myoglobin and the non-respiratory proteins neuroglobin and cytoglobin. Here, we describe their molecular adaptations to cold temperatures in the framework of the physiology of oxygen transport and management of oxidative stress in fish species largely populating the Ross Sea. 相似文献
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Malika Faouzi Valérie Chopin Ahmed Ahidouch Halima Ouadid-Ahidouch 《The Journal of membrane biology》2010,234(1):47-56
Prolactin (PRL) is a polypeptidic hormone which acts both systemically and locally to cause lactation by interacting with
the PRL receptor, a Janus kinase (JAK2)-coupled cytokine receptor family member. Several studies have reported that serum
PRL level elevation is associated with an increased risk for breast cancer, and evidence has suggested that PRL is one actor
in the pathogenesis and progression of this cancer. We previously reported the involvement of hIKCa1 in breast cell cycle
progression and cell proliferation. However, mechanisms by which PRL cooperates with these channels to modulate breast epithelial
cell proliferation remain unknown. Our results showed that, in the MCF-7 breast cancer cell line, PRL increased hIKCa1 current
density. These channels were functional and regulated the resting membrane potential. The PRL effects were inhibited by TRAM-34
and clotrimazole, the most used hIKCa1 blockers. Moreover, PRL increased proliferation in a dose-dependent manner without
overexpressing hIKCa1. To determine whether PRL-induced proliferation and hIKCa1 activity involved the JAK2 pathway, we used
pharmacological JAK2 inhibitors (AG490 and JAK inhibitor I). Indeed, PRL-induced JAK2 phosphorylation was required for both
cell proliferation and hIKCa1 activity. In the presence of either hIKCa1 blockers or siRNA-hIKCa1, PRL failed to increase
cell proliferation and hIKCa1 activity. Taken together, our results demonstrate that PRL plays a role in breast cancer cell
proliferation by increasing hIKCa1 activity through the JAK2 signaling pathway. 相似文献
929.
The Influence of Exogenous Testosterone on the Dynamics of Nestling Provisioning in Dark-Eyed Juncos 总被引:1,自引:0,他引:1
Ethan D. Clotfelter C. Ray Chandler† Val Nolan Jr ‡ & Ellen D. Ketterson‡ 《Ethology : formerly Zeitschrift fur Tierpsychologie》2007,113(1):18-25
In many songbird species, application of exogenous testosterone (T) during the breeding season has the general effects of reducing male parental investment and increasing allocation of time and energy to mating. Most studies record the number of feeding trips made by males as a function of their hormone treatment, but few have investigated the ways in which testosterone affects the dynamics of male and female provisioning behavior or the quantity of food delivered by males. We attempt to fill these gaps in our understanding of testosterone and male parental effort by utilizing data from a long‐term study on the behavioral endocrinology of the dark‐eyed junco (Junco hyemalis). We found that male and female feeding rates covaried positively, although to different degrees, throughout the nestling period, but that this relationship was degraded in pairs in which males were given T implants. We also found that the coefficients of variation in the duration of intervals between successive feeding trips by males and females were highly positively related in broods of older nestlings. Male hormone treatment, however, had no effect on the coefficients of variation in either male or female feeding intervals. Finally, we examined the quantity of prey delivered by males and found no significant effect of hormone treatment. 相似文献
930.
Sarcoplasmic reticulum vesicles from fast skeletal muscle were partially delipidated with sodium cholate at high ionic strength and sedimented in a discontinuous sucrose gradient. Phospholipid content was reduced from 0.777 mumol/mg protein to 0.242 mumol/mg protein. As judged from gel electrophoresis and high pressure liquid gel chromatography, accessory proteins were removed during centrifugation and the Ca2+-ATPase was obtained in an almost pure form. Addition of myristoylglycerophosphocholine (1 mg/mg protein) reactivates ATPase and dinitrophenylphosphatase activity to the same degree obtained with native vesicles. Using the analytical ultracentrifuge it could be demonstrated that the reactivated Ca2+-ATPase was present exclusively in a monomeric state. These results were obtained at high and low ionic strength and up to a protein concentration of 10 mg/ml. Therefore this preparation should be very useful to investigate differences between oligomeric and monomeric Ca2+-ATPase. 相似文献