2,723 research outputs found

    Embryonic, Larval, and Juvenile Development of the Sea Biscuit Clypeaster subdepressus (Echinodermata: Clypeasteroida)

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    Sea biscuits and sand dollars diverged from other irregular echinoids approximately 55 million years ago and rapidly dispersed to oceans worldwide. A series of morphological changes were associated with the occupation of sand beds such as flattening of the body, shortening of primary spines, multiplication of podia, and retention of the lantern of Aristotle into adulthood. To investigate the developmental basis of such morphological changes we documented the ontogeny of Clypeaster subdepressus. We obtained gametes from adult specimens by KCl injection and raised the embryos at 26C. Ciliated blastulae hatched 7.5 h after sperm entry. During gastrulation the archenteron elongated continuously while ectodermal red-pigmented cells migrated synchronously to the apical plate. Pluteus larvae began to feed in 3 d and were 20 d old at metamorphosis; starved larvae died 17 d after fertilization. Postlarval juveniles had neither mouth nor anus nor plates on the aboral side, except for the remnants of larval spicules, but their bilateral symmetry became evident after the resorption of larval tissues. Ossicles of the lantern were present and organized in 5 groups. Each group had 1 tooth, 2 demipyramids, and 2 epiphyses with a rotula in between. Early appendages consisted of 15 spines, 15 podia (2 types), and 5 sphaeridia. Podial types were distributed in accordance to Lovén's rule and the first podium of each ambulacrum was not encircled by the skeleton. Seven days after metamorphosis juveniles began to feed by rasping sand grains with the lantern. Juveniles survived in laboratory cultures for 9 months and died with wide, a single open sphaeridium per ambulacrum, aboral anus, and no differentiated food grooves or petaloids. Tracking the morphogenesis of early juveniles is a necessary step to elucidate the developmental mechanisms of echinoid growth and important groundwork to clarify homologies between irregular urchins

    Stiffness and energy losses in cylindrically symmetric superconductor levitating systems

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    Stiffness and hysteretic energy losses are calculated for a magnetically levitating system composed of a type-II superconductor and a permanent magnet when a small vibration is produced in the system. We consider a cylindrically symmetric configuration with only vertical movements and calculate the current profiles under the assumption of the critical state model. The calculations, based on magnetic energy minimization, take into account the demagnetization fields inside the superconductor and the actual shape of the applied field. The dependence of stiffness and hysteretic energy losses upon the different important parameters of the system such as the superconductor aspect ratio, the relative size of the superconductor-permanent magnet, and the critical current of the superconductor are all systematically studied. Finally, in view of the results, we provide some trends on how a system such as the one studied here could be designed in order to optimize both the stiffness and the hysteretic losses.Comment: 8 pages; 8 figure

    c-Src inhibition improves cardiovascular function but not remodeling or fibrosis in Ang II-induced hypertension

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    c-Src plays an important role in angiotensin II (Ang II) signaling. Whether this member of the Src family kinases is involved in the development of Ang II–induced hypertension and associated cardiovascular damage in vivo remains unknown. Here, we studied Ang II–infused (400 ng/kg/min) mice in which c-Src was partially deleted (c-Src+/−) and in wild-type (WT, c-Src+/+) mice treated with a c-Src inhibitor (CGP077675; 25 mg/kg/d). Ang II increased blood pressure and induced endothelial dysfunction in WT mice, responses that were ameliorated in c-Src+/− and CGP077675-treated mice. Vascular wall thickness and cross-sectional area were similarly increased by Ang II in WT and c-Src+/− mice. CGP077675 further increased cross-sectional area in hypertensive mice. Cardiac dysfunction (ejection fraction and fractional shortening) in Ang II–infused WT mice was normalized in c-Src+/− mice. Increased oxidative stress (plasma thiobarbituric acid–reactive substances, hydrogen peroxide, and vascular superoxide generation) in Ang II–infused WT mice was attenuated in c-Src–deficient and CGP077675-treated mice. Hyperactivation of vascular c-Src, ERK1/2 (extracellular signal–regulated kinase 1/2), and JNK (c-Jun N-terminal kinase) in hypertensive mice was normalized in CGP077675-treated and c-Src+/− mice. Vascular fibronectin was increased by Ang II in all groups and further augmented by CGP077675. Cardiac fibrosis and inflammation induced by Ang II were amplified in c-Src+/− and CGP-treated mice. Our data indicate that although c-Src downregulation attenuates development of hypertension, improves endothelial and cardiac function, reduces oxidative stress, and normalizes vascular signaling, it has little beneficial effect on fibrosis. These findings suggest a divergent role for c-Src in Ang II–dependent hypertension, where c-Src may be more important in regulating redox-sensitive cardiac and vascular function than fibrosis and remodeling

    Common features between neoplastic and preneoplastic lesions of the biliary tract and the pancreas

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    The bile duct system and pancreas show many similarities due to their anatomical proximity and common embryological origin. Consequently, preneoplastic and neoplastic lesions of the bile duct and pancreas share analogies in terms of molecular, histological and pathophysiological features. Intraepithelial neoplasms are reported in biliary tract, as biliary intraepithelial neoplasm (BilIN), and in pancreas, as pancreatic intraepithelial neoplasm (PanIN). Both can evolve to invasive carcinomas, respectively cholangiocarcinoma (CCA) and pancreatic ductal adenocarcinoma (PDAC). Intraductal papillary neoplasms arise in biliary tract and pancreas. Intraductal papillary neoplasm of the biliary tract (IPNB) share common histologic and phenotypic features such as pancreatobiliary, gastric, intestinal and oncocytic types, and biological behavior with the pancreatic counterpart, the intraductal papillary mucinous neoplasm of the pancreas (IPMN). All these neoplastic lesions exhibit similar immunohistochemical phenotypes, suggesting a common carcinogenic process. Indeed, CCA and PDAC display similar clinic-pathological features as growth pattern, poor response to conventional chemotherapy and radiotherapy and, as a consequence, an unfavorable prognosis. The objective of this review is to discuss similarities and differences between the neoplastic lesions of the pancreas and biliary tract with potential implications on a common origin from similar stem/progenitor cells

    Semi-field assessment of the BG-Malaria trap for monitoring the African malaria vector, Anopheles arabiensis

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    Odour-baited technologies are increasingly considered for effective monitoring of mosquito populations and for the evaluation of vector control interventions. The BG-Malaria trap (BGM), which is an upside-down variant of the widely used BG-Sentinel trap (BGS), has been demonstrated to be effective to sample the Brazilian malaria vector, Anopheles darlingi. We evaluated the BGM as an improved method for sampling the African malaria vectors, Anopheles arabiensis. Experiments were conducted inside a large semi-field cage to compare trapping efficiencies of BGM and BGS traps, both baited with the synthetic attractant, Ifakara blend, supplemented with CO2. We then compared BGMs baited with either of four synthetic mosquito lures, Ifakara blend, Mbita blend, BG-lure or CO2, and an unbaited BGM. Lastly, we compared BGMs baited with the Ifakara blend dispensed via either nylon strips, BG cartridges (attractant-infused microcapsules encased in cylindrical plastic cartridge) or BG sachets (attractant-infused microcapsules encased in plastic sachets). All tests were conducted between 6P.M. and 7A.M., with 200–600 laboratory-reared An. arabiensis released nightly in the test chamber. The median number of An. arabiensis caught by the BGM per night was 83, IQR:(73.5–97.75), demonstrating clear superiority over BGS (median catch = 32.5 (25.25–37.5)). Compared to unbaited controls, BGMs baited with Mbita blend caught most mosquitoes (45 (29.5–70.25)), followed by BGMs baited with CO2 (42.5 (27.5–64)), Ifakara blend (31 (9.25–41.25)) and BG lure (16 (4–22)). BGM caught 51 (29.5–72.25) mosquitoes/night, when the attractants were dispensed using BG-Cartridges, compared to BG-Sachet (29.5 (24.75–40.5)), and nylon strips (27 (19.25–38.25)), in all cases being significantly superior to unbaited controls (p < 000.1). The findings demonstrate potential of the BGM as a sampling tool for African malaria vectors over the standard BGS trap. Its efficacy can be optimized by selecting appropriate odour baits and odour-dispensing systems

    Aderenza alle cure: un tema di pertinenza anche infermieristica

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    Gli interventi educativi per i pazienti con scompenso cardiaco: una sintesi della letteratura

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    Patient education is recognized as a central component of heart failure care and reduces hospital readmissions. Nurses have an important role in providing patient education and modifying self-care behaviors. The aim of this article is to examine characteristics of educational interventions for heart failure patients, their measured outcomes and the role of nurses in providing education. We conducted a literature review of the last 10 years and considered 30 articles. Multisession motivational interventions, repeated over time and with different follow-up interventions seem to produce the best results. However, some aspects remain controversial

    Social media and nurse education: an integrative reviewof the literature

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    Introduction. The exponential advance of social media has touched all areas of society, no exception for the professional and personal lives of healthcare people. The issue to be considered is not whether or not social media are being used, but how they are used. The line between proper and improper use, and even abuse, of social media is a subtle one. Thus, the key issue is to be aware of the tool that is being used and this should be supported with suitable training for healthcare professionals and, at an even earlier stage, for students at healthcare training institutions during their studies. Objective. To describe, through an integrative review of the literature, the use of social media by teachers and students during teaching activity and practical training courses. Materials and methods. An integrative review of the literature was conducted in October 2014. The literature search was performed by consulting the main biomedical databases: PubMed, CINAHL and Embase. Results. The literature search brought up a total of 854 citations. 804 abstracts were excluded as they were not relevant. Of the remaining 50, 31 were excluded for not meeting the general criteria and, hence, only 19 articles were included. Two aspects emerged from the works selected: the use and potential of social media in nursing education and the ethical and professional implications of their use. Conclusions. The analysis of the literature reveals two areas for further investigation: evaluating the level of moral awareness in nursing education with regards to the use of Web 2.0 communication tools and implementing teaching methods to promote the construction and development of moral reasoning in professionals

    Validity and reliability of the Italian version of the Oral Assessment Guide

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    Mucositis is a frequent side-effect of chemotherapy and radiotherapy. Assessment of oral cavity is important to detect alterations in the mouth and plan appropriate interventions. A reliable tool can help to have a better assessment of mucositis and a major knowledge about this phenomenon. Since no valid and reliable tool for the assessment of mucositis is still available in Italy, the aim of this study was to establish the validity and reliability of the Italian version of the Oral Assessment Guide (OAG). A panel of health care experts established the content validity of the tool both for the items and the descriptors. To establish the reliability of the tool, a sample of 14 inpatients with haematological diseases were recruited. Couples of dental hygienists separately performed 60 pairs of assessments (for a total of 120 assessments) on the sample. The Italian version of OAG was found to have an acceptable Content Validity Index (CVI) for items and related descriptors ranging between 0.67 and 1. Cronbach’s alpha was 0.84, agreement of assessment ranged between 0.87 and 0.65 with Cohen’s Kappa coefficient ranging from good to very good. This study showed that the Italian version of the OAG has good psychometric properties of validity and reliability to assess mucositis in patients undergoing chemotherapy. This tool will have a great importance to carry out future research in Italy aimed to improve the patient's outcomes particularly in terms of functional ability and quality of life
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