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71.
Cross-talk between the sympathetic nervous system (SNS) and immune system is vital for health and well-being. Infection, tissue injury and inflammation raise firing rates of sympathetic nerves, increasing their release of norepinephrine (NE) in lymphoid organs and tissues. NE stimulation of β2-adrenergic receptors (ARs) in immune cells activates the cAMP-protein kinase A (PKA) intracellular signaling pathway, a pathway that interfaces with other signaling pathways that regulate proliferation, differentiation, maturation and effector functions in immune cells. Immune–SNS cross-talk is required to maintain homeostasis under normal conditions, to develop an immune response of appropriate magnitude after injury or immune challenge, and subsequently restore homeostasis. Typically, β2-AR-induced cAMP is immunosuppressive. However, many studies report actions of β2-AR stimulation in immune cells that are inconsistent with typical cAMP–PKA signal transduction. Research during the last decade in non-immune organs, has unveiled novel alternative signaling mechanisms induced by β2-AR activation, such as a signaling switch from cAMP–PKA to mitogen-activated protein kinase (MAPK) pathways. If alternative signaling occurs in immune cells, it may explain inconsistent findings of sympathetic regulation of immune function. Here, we review β2-AR signaling, assess the available evidence for alternative signaling in immune cells, and provide insight into the circumstances necessary for “signal switching” in immune cells. 相似文献
72.
Denise Loder Susanne Katharina Michelic Christian Bernhard 《BHM Berg- und Hüttenm?nnische Monatshefte》2016,161(7):315-320
The formation of acicular ferrite is mainly influenced by the steel composition, cooling rate, austenite grain size, and inclusion landscape. However, their precise effects have not been clarified in literature yet. Within the FWF project TRP 266-N19, a systematic methodology to study the influencing factors of the acicular ferrite formation as well as their interactions on laboratory scale was developed. The present work exemplarily demonstrates the application of this methodology for studying the effect of cooling rate and boron on the formation of acicular ferrite in a low-carbon HSLA steel. 相似文献
73.
Juliana Mendes de Oliveira Iara Alves Anes Jorge Luís Coleti Denise Crocce Romano Espinosa Marcelo Siqueira de Carvalho Jorge Alberto Soares Tenório 《加拿大化工杂志》2023,101(4):1743-1761
Niobium (Nb) and Tantalum (Ta) are used to increase materials' mechanical resistance and produce lighter alloys. Worldwide Nb production reached 78 000 t in 2020. The reduced ore offer justifies the recycling of these metals from tin slag, contributing to the circular economy. Nb2O5 and Ta2O5 extraction either from the primary source or the tin slag is an industrial challenge. Nb and Ta dissolution processes already implemented are fluoride leaching, sulphuric leaching, alkaline leaching, and alkaline roasting. The fluoride process raises environmental concerns about waste control. The sulphuric method can be managed to have higher Nb and Ta extraction in a less aggressive process, if some changes are implemented, such as increasing the number of extraction steps, decreasing the pulp density, or increasing the temperature; however, the efficiency of this methodology must be tested for tin slag. The alkaline method seems to be more selective to Nb and Ta by reactants and temperature control. Despite those well-established Nb and Ta treatments, they must be adapted to recover Nb and Ta from slag. The slag has low Nb and Ta content, while high Si and Ca concentrations exist in the matrix. This paper brings the main methods used to extract the Nb and Ta from the primary resources and an overview of Nb and Ta recovery from the slag. This investigation comes as a tool to guide the development of new methods to recover Nb and Ta from low-grade sources such as tin slag. 相似文献
74.
This article describes the need for psychologists working with persons with disabilities to establish validity procedures within research findings and clinical practices. It highlights the importance of providing a contextual framework for behavior by adopting a socioecological paradigm of disability. Theoretical, research, and clinical practice implications are discussed, such as the evolution of paradigms guiding rehabilitation, the need to move research out of the laboratories and into the field, and the importance of focusing on the broader socioenvironmental needs of persons with disabilities. The author also offers specific recommendations for psychologists engaged in activities across education, research, and clinical practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
75.
This study investigated age, cognitive abilities, health beliefs, and other factors in women's judgments about effective treatments for menopause. Women (N?=?102) ranging in age from 20 to 79 read a vignette about a woman facing a decision about Estrogen Replacement Therapy (ERT) and then made judgments about what should be done. Participants also completed a battery of questions pertaining to ERT and cognitive abilities. Path-analytic techniques were used to determine the role of specific cognitive abilities and the representation of menopause and its treatment in making judgments about ERT treatments. Cognitive abilities had direct effects on treatment decisions. Education affected the number of perceived options for treatment. Age and education indirectly affected treatment decisions, operating through cognitive abilities. Factors related to the mental representation of menopause had no direct effects and few indirect effects on treatment decisions. Potential mechanisms that can help older adults compensate for declines in cognitive abilities in medical decisions are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
76.
This meta-analysis addressed the question of how effective grief therapy is and for whom, using B. J. Becker's (1988) techniques for analyzing standardized mean-change scores. Analyses were based on 35 studies (N?=?2,284), with a weighted mean effect size (ES) of δ+?=?0.43 (95% confidence interval?=?0.33 to 0.52). Clients in no-treatment control groups showed little improvement (d=?=?0.06), possibly because of the relatively long delay between loss and treatment in most studies (mean delay?=?27 months). Moderators of treatment efficacy included time since loss and relationship to the deceased. Client selection procedures, a methodological factor not originally coded in this meta-analysis, appeared to contribute strongly to variability in ESs: a small number of studies involving self-selected clients produced relatively large ESs, whereas the majority of studies involving clients recruited by the investigators produced ESs in the small to moderate range. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
77.
The enhancement of the 1 day strength of cementitious systems by a combination of calcium chloride (CaCl2) and diethanol-isopropanolamine (DEIPA) was studied, particularly in blended cement systems. A combination of quantitative X-ray diffraction with Rietveld refinement (QXRD), scanning electron microscopy (SEM)/backscattered electron image analysis, thermogravimetric analysis (TGA), and isothermal calorimetry were used to investigate the mechanism of strength enhancement by the additives. The additives were found to increase the early age mortar strength by enhancing the cement hydration, with the DEIPA enhancing primarily the aluminate hydration. DEIPA also affected the morphology of portlandite which was formed as thin plates. In parallel, the calcium-to-silica ratio of the C-S-H was found to increase with the use of DEIPA, possibly because of the inclusion of microcrystalline portlandite. After 48 h DEIPA was found to directly enhance the rate of reaction of granulated blast-furnace slag and fly ash. 相似文献
78.
Juliana Q. Mollica Denise C. Cara Mirna D’Auriol Verena B. Oliveira Isabela C. Cesar Maria G.L. Brandão 《Journal of Functional Foods》2013,5(4):1975-1984
Tropical ecosystems are particularly rich in edible plant species with different bioactive substances. Among the plants with promising benefits for health are species from the genus Dioscorea (Dioscoreaceae), especially those named yam. Recent studies have shown the beneficial effects of different species of Dioscorea, and its main constituent, diosgenine, in the treatment of food allergy. In this study we evaluated the potential of D. trifida, the only yam native from South America, in the treatment of ovalbumin (OVA) induced food allergy in Balb/c mice. HPLC/DAD analysis showed the presence of three very distinctive groups of natural products in extracts and fractions: (I) very polar substances, including allantoin, (II) phenolic substances as flavonoids and phenolic acids and (III) diosgenin and derivatives. Sensitive mice received casein feed with supplementation of crude extract (CE) and fractions. The supplementation with all products from D. trifida reduced IGE, intestinal oedema and mucus production, parameters observed in OVA allergic mice. The results showed the potential of this food to prevent or treat this disease and the necessity to be better explored. 相似文献
79.
V.M.F. Alexandre A.M. Valente Magali C. Cammarota Denise M.G. Freire 《Renewable Energy》2011,36(12):3439-3444
The effect of a lipase-rich enzyme preparation produced by the fungus Penicillium simplicissimum on solid-state fermentation was evaluated in a 4.9 L up-flow anaerobic sludge blanket bioreactor (UASB) treating fish-processing plant wastewater containing 1500 mg oil and grease (O&G)/L. The oil and grease hydrolysis step was carried out with 0.5% or 0.2% (w/v) of the solid enzyme preparation (SEP) at 30 °C for 8 h. The bioreactor operated at 30 °C with a hydraulic retention time of 10 h for a period of over 100 days, showed high total COD removal efficiencies (85.3% for 0.5% SEP and 90.9% for 0.2% SEP), when fed with pre-hydrolyzed wastewater, compared to a Control bioreactor fed with raw wastewater (79.9%). The Control bioreactor also showed high oil and grease accumulation in the biomass throughout the operational period (the O&G content reached 1.7 times that found in the inoculum of the UASB bioreactor), intensive scum formation, and several episodes of cessation of treatment to clean the three-phase separator. Thus it can be concluded that the enzyme pre-hydrolysis step together with anaerobic treatment of the fish-processing plant wastewater improved the quality of the treated effluent and reduced operational problems. 相似文献
80.
Comments on the article by N. F. Kozlowski et al (see record 1998-10341-011) about HIV infected clients and whether or not there ought to be notification. Kozlowski et al cite the California case of Tarasoff v. Regents of University of California (1976) 9 times, however, they never officially cite it, nor do they put it in their reference section. Without going into a refresher course about the meaning of Tarasoff, when employing this case law in a study it is important to (1) carefully read the case, (2) become familiar with the case law in your state or states, (3) shepardize all relevant cases to make sure that they are still good law (there has been a lot of movement with Tarasoff over the years), and (4) have at least a consultation with an attorney who is familiar with this area of law. Legal accuracy is extremely important and without it, our studies cannot withstand interdisciplinary scrutiny. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献