179 research outputs found
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Refining As-Cast Structures of Novel SixTiVCrZr High-Entropy Alloys Using Estimated Effective Solidification Temperature Obtained Using Chvorinov's Rule
High-entropy alloys (HEAs), i.e., multicomponent alloys where (typically five or more) elements are combined in equal, or roughly equal, quantities, are of great current interest, due to their formation of single, simple structured phases, and the unusual properties they can potentially exhibit. Phase presence may be predicted using semi-empirical methods, but deviations from predictions may be seen during the course of alloy synthesis, with the formation of unexpected phases. The generation of such phases may be controlled with knowledge of the effective solidification temperature; in this full article, Chvorinov’s rule for solidification time is used to estimate this temperature as part of the design of a new multiphase alloy system, TiVCrZr-Six. Further heat treatment of the TiVCrZr-Si system confirms the applicability of this approach. The new compositions demonstrate mechanical properties that suggest potential for optimization for high-temperature applications.</jats:p
Electroacupuncture activates corticotrophin-releasing hormone-containing neurons in the paraventricular nucleus of the hypothalammus to alleviate edema in a rat model of inflammation
<p>Abstract</p> <p>Background</p> <p>Studies show that electroacupuncture (EA) has beneficial effects in patients with inflammatory diseases. This study investigated the mechanisms of EA anti-inflammation, using a rat model of complete Freund's adjuvant (CFA)-induced hind paw inflammation and hyperalgesia.</p> <p>Design</p> <p>Four experiments were conducted on male Sprague-Dawley rats (n = 6–7/per group). Inflammation was induced by injecting CFA into the plantar surface of one hind paw. Experiment 1 examined whether EA increases plasma adrenocorticotropic hormone (ACTH) levels. Experiments 2 and 3 studied the effects of the ACTH and corticotropin-releasing hormone (CRH) receptor antagonists, ACTH<sub>(11–24) </sub>and astressin, on the EA anti-edema. Experiment 4 determined whether EA activates CRH neurons in the paraventricular nucleus of the hypothalammus. EA treatment, 10 Hz at 3 mA and 0.1 ms pulse width, was given twice for 20 min each, once immediately post and again 2 hr post-CFA. Plasma ACTH levels, paw thickness, and paw withdrawal latency to a noxious thermal stimulus were measured 2 h and 5 h after the CFA.</p> <p>Results</p> <p>EA significantly increased ACTH levels 5 h (2 folds) after CFA compared to sham EA control, but EA alone in naive rats and CFA alone did not induce significant increases in ACTH. ACTH<sub>(11–24) </sub>and astressin blocked EA anti-edema but not EA anti-hyperalgesia. EA induced phosphorylation of NR1, an essential subunit of the N-methyl-D-aspartic acid (NMDA) receptor, in CRH-containing neurons of the paraventricular nucleus.</p> <p>Conclusion</p> <p>The data demonstrate that EA activates CRH neurons to significantly increase plasma ACTH levels and suppress edema through CRH and ACTH receptors in a rat model of inflammation.</p
Neuroprotective and neurodegenerative effects of the chronic expression of tumor necrosis factor α in the nigrostriatal dopaminergic circuit of adult mice
Regulation of Intestinal Immune Response by Selective Removal of the Anterior, Posterior, or Entire Pituitary Gland in Trichinella spiralis Infected Golden Hamsters
The influence of anterior pituitary hormones on the gastrointestinal tract of humans and animals has been previously reported. Hypophysectomy (HYPOX) in the rat causes atrophy of the intestinal mucosa, and reduction of gastric secretion and intestinal absorption, as well as increased susceptibility to bacterial and viral infections. However, to our knowledge, no findings have been published concerning the immune response following HYPOX during worm infection, particularly that which is caused by the nematode Trichinella spiralis. The aim of this work was to analyze the effects of total or partial HYPOX on colonization of T. spiralis in the intestinal lumen, together with duodenal and splenic cytokine expression. Our results indicate that 5 days post infection, only neurointermediate pituitary lobectomy (NIL) reduces the number of intestinally recovered T. spiralis larvae. Using semiquantitative inmunofluorescent laser confocal microscopy, we observed that the mean intensity of all tested Th1 cytokines was markedly diminished, even in the duodenum of infected controls. In contrast, a high level of expression of these cytokines was noted in the NIL infected hamsters. Likewise, a significant decrease in the fluorescence intensity of Th2 cytokines (with the exception of IL-4) was apparent in the duodenum of control and sham infected hamsters, compared to animals with NIL surgeries, which showed an increase in the expression of IL-5 and IL-13. Histology of duodenal mucosa from NIL hamsters showed an exacerbated inflammatory infiltrate located along the lamina propria, which was related to the presence of the parasite. We conclude that hormones from each pituitary lobe affect the gastrointestinal immune responses to T. spiralis through various mechanisms
Neuroendocrine–immune disequilibrium and endometriosis: an interdisciplinary approach
Endometriosis, a chronic disease characterized by endometrial tissue located outside the uterine cavity, affects one fourth of young women and is associated with chronic pelvic pain and infertility. However, an in-depth understanding of the pathophysiology and effective treatment strategies of endometriosis is still largely elusive. Inadequate immune and neuroendocrine responses are significantly involved in the pathophysiology of endometriosis, and key findings are summarized in the present review. We discuss here the role of different immune mechanisms particularly adhesion molecules, protein–glycan interactions, and pro-angiogenic mediators in the development and progression of the disease. Finally, we introduce the concept of endometrial dissemination as result of a neuroendocrine-immune disequilibrium in response to high levels of perceived stress caused by cardinal clinical symptoms of endometriosis
Chronic occupational exposures can influence the rate of PTSD and depressive disorders in first responders and military personnel
Three American Troops in Iraq: Evaluation of a Brief Exposure Therapy Treatment for the Secondary Prevention of Combat - Related PTSD *
Relatively little research has been devoted to developing empirically-supported interventions for the secondary prevention of chronic post-traumatic stress disorder (i.e., for individuals who have developed PTSD symptoms but not the full PTSD disorder). One-session psychological debriefing has been routinely used as a primary preventive intervention for individuals exposed to trauma, but the appropriateness of this practice has been questioned. The authors describe an alternative, secondary prevention model of brief exposure- based treatment using three cases of military members seeking help at a forward-deployed medical clinic in Iraq for PTSD symptoms following combat -related traumas. Treatment involved repeated imaginal exposure and in vivo exposure conducted in four therapy sessions over a five-week period. Baseline measures on the PTSD Checklist were at a level that is considered to be in the range of PTSD. The results indicated that after four treatment sessions, PTSD symptoms were reduced by an average of 56%, and the final PTSD Checklist scores were within normal limits. The results suggest that prolonged exposure therapy may be a rapid individual treatment for the secondary prevention of combat-related PTSD
The Scientist-Practitioner on the Front Line: Development and Formalization of Evidenced-Based Interventions on the Battlefield
Nathan (2005) and Petronko (2005) provide excellent commentaries on our three case studies (Cigrang, Peterson, & Schobitz, 2005) describing the use of prolonged imaginal exposure for the secondary prevention of Post-Traumatic Stress Disorder (PTSD). In this response, we note that future research should build upon the lessons and experiences of these cases and include larger sample sizes, additional measures (anxiety, depression, grief, quality of life, subjective units of distress ratings), the development of a flexible treatment manual, and formal measures of Acute Stress Disorder (ASD). Future research should also target process measures such as patient acceptability of the treatment and willingness to engage in the exposure sessions. Deployed military psychologists, in collaboration with civilian researchers, have the potential to further advance the scientific knowledge base on the assessment and treatment of combat-stress disorders through the use of innovative case studies. The potential importance of research and formalized treatments for individuals exposed to the significant psychological trauma related to terrorist attacks and bombings is highlighted
PelÃcula antimicrobiana a base de proteÃna de suero lácteo, incorporada con bacterias lácticas como controlador de listeria monocytogenes, aplicada sobre salmón ahumado
El concentrado de proteÃna de suero lácteo (CPS) posee propiedadesfuncionales apropiadas para la elaboración de pelÃculas biopreservantes,siendo factible la incorporación de bacterias ácido lácticas (BAL) produc-toras de sustancias tipo bacteriocina (STB) y asÃ, lograr un efecto contro-lador sobre Listeria monocytogenes al ser utilizada como cobertura sobresalmón ahumado. Las condiciones para la formación de la pelÃcula fueron:CPS 12% p/v, glicerol 18% v/v, pH en solución formadora de pelÃcula 7,0y 8,0, y secado a 30ºC por 16 horas. La actividad inhibitoria de la pelÃculaincorporada con las cepas lácticas fue evaluada usando el método dedifusión frente a un césped de L. monocytogenes y mediante el recuentoen placa, obteniendo: la combinación de dos cepas BAL aumentó la ac-tividad controladora sobre L. monocytogenes logrando reducir hasta 2,1ciclos logarÃtmicos el crecimiento de este patógeno, bajo condiciones derefrigeración durante 15 dÃas
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