1,006 research outputs found
Structural phase transitions and their influence on Cu+ mobility in superionic ferroelastic Cu6PS5I single crystals
The structural origin of Cu+ ions conductivity in Cu6PS5I single crystals is
described in terms of structural phase transitions studied by X-ray
diffraction, polarizing microscope and calorimetric measurements. Below the
phase transition at Tc=(144-169) K Cu6PS5I belongs to monoclinic, ferroelastic
phase, space group Cc. Above Tc crystal changes the symmetry to cubic
superstructure, space group F-43c (a=19.528); finally at 274K disordering of
the Cu+ ions increases the symmetry to F-43m, (a=9.794). The phase transition
at 274K coincides well with a strong anomaly in electrical conductivity
observed in the Arrhenius plot. Diffusion paths for Cu+ ions are evidenced by
means of the atomic displacement factors and split model. Influence of the
copper stechiometry on the Tc is also discussed.Comment: conference pape
The impact of nanosilver addition on element ions release form light-cured dental composite and compomer into 0.9% NaCl
The aim of this paper was to identify and to assess in semi-quantified way the release of different ions from composite and compomer restorative materials subjected to 0.9% NaCl solution, which simulates the environment of the human body. In the present study, the number of ions (Al, Ag, Ba, Sr, Ti) released from dental fillings over time (one week, one month and 3 months), in different temperatures (23°C, 37°C) and depending on the materials applied (unmodified/modified with nanosilver) was investigated. The results suggest that nanosilver addition influences directly on the process of metal ion releasing into 0.9% NaCl solution. The increase in the number of counts of metal ions was observed in the solutions in which samples modified with nanosilver were kept. Higher amount of metal ion release was observed for composite samples rather than for compomer materials. The study revealed that in general the number of released metal ions increases with the time of storage (for metal ions: Ti, Ba, Sr) and at higher temperature (Ag, Ti, Ba). Reverse tendency observed for silver ion release versus incubation time may be caused by the process of silver adsorption, which takes place on the surface of analyzed material and test-tube walls, where samples were incubated
A Data-informed Public Health Policy-Makers Platform
Hearing loss is a disease exhibiting a growing trend due to the number of factors, including but not limited to the mundane exposure to the noise and ever-increasing amount of older population. In the framework of a public health policymaking process, modeling of the hearing loss disease based on data is a key factor in alleviating the issues related to the disease issuing effective public health policies. First, the paper describes the steps of the data-driven policymaking process. Afterward, a scenario along with the part of the proposed platform, responsible for supporting policymaking are presented. With the aim of demonstrating the capabilities and usability of the platform for the policy-makers, some initial results of preliminary analytics are presented in a framework of a policy-making process. Ultimately, the utility of the approach is validated throughout the results of the survey which was presented to the health system policy-makers professionals involved in the policy development process in Croatia
Nanomaterials Modification by Dendrimers - A Review
Following review summarizes the application of dendrimer-functionalized hybrid nanomaterials. Dendrimers are nano-sized, radially symmetric molecules with well-defined, homogeneous and monodisperse structure. Incorporation of dendritic structures onto surface of inorganic particles by covalent, ionic and van der Waals bonds introduces unique properties of the new material. Herein, we present structures and properties of silica, titania, carbon nanotubes and clays decorated with various dendrimers
The influence of low-frequency noise pollution on the quality of life and place in sustainable cities: a case study from northern Portugal
Discussing urban planning requires rethinking sustainability in cities and building healthy environments. Historically, some aspects of advancing the urban way of life have not been considered important in city planning. This is particularly the case where technological advances have led to conflicting land use, as with the installation of power poles and building electrical substations near residential areas. This research aims to discuss and rethink sustainability in cities, focusing on the environmental impact of low-frequency noise and electromagnetic radiation on human health. It presents data from a case study in an urban space in northern Portugal, and focuses on four guiding questions:
Can power poles and power lines cause noise? Do power poles and power lines cause
discomfort? Do power poles and power lines cause discomfort due to noise? Can power
poles and power lines affect human health? To answer these questions, we undertook
research between 2014 and 2015 that was comprised of two approaches. The first approach consisted of evaluating the noise of nine points divided into two groups â near the sourceâ (e.g., up to 50 m from power poles) and â away from the sourceâ (e.g., more than 250 m away from the source). In the second approach, noise levels were measured for 72 h in houses located up to 20 m from the source. The groups consist of residents living within the distance range specified for each group. The measurement values were compared with the proposed criteria for assessing low-frequency noise using the DEFRA Guidance (University of Salford). In the first approach, the noise caused discomfort, regardless of the group. In the second approach, the noise had fluctuating characteristics, which led us to conclude that the noise caused discomfort.The authors wish to acknowledge CAPES/Brazil for the doctoral scholarship in Geography for Juliana Araujo Alves (Process: BEX-1684-13/2) and Bruno Ricardo Dias Goncalves Mendes (Ph.D. Student at the Faculty of Engineering, University of Minho) for the technical support in this research
Ferroelectric Phase Transitions in Films with Depletion Charge
We consider ferroelectric phase transitions in both short-circuited and
biased ferroelectric-semiconductor films with a space (depletion) charge which
leads to some unusual behavior. It is shown that in the presence of the charge
the polarization separates into `switchable' and `non-switchable' parts. The
electric field, appearing due to the space charge, does not wash out the phase
transition, which remains second order but takes place at somewhat reduced
temperature. At the same time, it leads to a suppression of the
ferroelectricity in a near-electrode layer. This conclusion is valid for
materials with both second and first order phase transitions in pure bulk
samples. Influence of the depletion charge on thermodynamic coercive field
reduces mainly to the lowering of the phase transition temperature, and its
effect is negligible. The depletion charge can, however, facilitate an
appearance of the domain structure which would be detrimental for device
performance (fatigue). We discuss some issues of conceptual character, which
are generally known but were overlooked in previous works. The present results
have general implications for small systems with depletion charge.Comment: 11 pages, REVTeX 3.1, five eps-figures included in the text. Minor
clarifications in the text. To appear in Phys. Rev. B 61, Apr 1 (2000
The Untapped Potential of Introvert Leaders
Academic research shows that extroverts are generally seen as more productive and
effective leaders than their introvert counterparts because they possess the characteristics our society has so often revered (Grant, Gino, & Hofmann, 2009). With the rise of the “extrovert ideal” throughout our society, introverts are left wondering what role they play when it comes to leadership (Cain, 2013). Through examples of four successful introvert leaders (Susan Cain, Warren Buffett, Laura Bush, and Bill Gates), it can be derived that it is not the personality that makes the leader but, rather, the passion, drive, and self-actualization of the individual. With greater emphasis on education, development, and training when it comes to utilizing one’s strengths innately within one’s personality, the potential of introverts, often hidden by shame, remorse, and feelings of inadequacy, will no longer go untapped
Evaluation of the influence of therapeutic factors on the cosmetic effects of conservative treatment of patients with breast carcinoma
Pedicled and skeletonized single and bilateral internal thoracic artery grafts and the incidence of sternal wound complications: Insights from the Arterial Revascularization Trial
Objectives: The question of whether skeletonized internal thoracic artery harvesting reduces the incidence of sternal wound complications in comparison with the pedicled technique, in the context of single or bilateral internal thoracic arteries, remains controversial. We studied the impact of the internal thoracic artery harvesting strategy on sternal wound complication in the Arterial Revascularization Trial. Methods: Patients enrolled in the Arterial Revascularization Trial (n = 3102) were randomized to coronary artery bypass grafting with single or bilateral internal thoracic arteries. Sternal wound complication rates were examined according to the harvesting technique that was documented in 2056 patients. The internal thoracic artery harvesting technique, based on the surgeon's preference, resulted in 4 groups: pedicled single internal thoracic artery (n = 607), pedicled bilateral internal thoracic artery (n = 459), skeletonized single internal thoracic artery (n = 512), and skeletonized bilateral internal thoracic artery (n = 478). Propensity scores weighting was used to estimate the impact of the harvesting technique on sternal wound complications. Results: A total of 219 of 2056 patients (10.6%) experienced a sternal wound complication within 1 year from the index operation. Of those, only 25 patients (1.2%) required sternal wound reconstruction. Pedicled bilateral internal thoracic artery (odds ratio [OR], 1.80; 95% confidence interval [CI], 1.23-2.63) but not skeletonized bilateral internal thoracic artery (OR, 1.00; 95% CI, 0.65-1.53) or skeletonized single internal thoracic artery (OR, 0.89; 95% CI, 0.57-1.38) was associated with a significantly increased risk of any sternal wound complications compared with pedicled single internal thoracic artery. Conclusions: The present Arterial Revascularization Trial substudy suggests that, with a skeletonization technique, the risk of sternal wound complication with bilateral internal thoracic artery grafting is similar to that after standard pedicled single internal thoracic artery harvesting, whereas skeletonized single internal thoracic artery harvesting did not add any further benefit when compared with pedicled single internal thoracic artery harvesting
Hypothalamic-pituitary-adrenal (HPA) axis suppression after treatment with glucocorticoid therapy for childhood acute lymphoblastic leukaemia
Background Glucocorticoids play a major role in the treatment of acute lymphoblastic leukaemia (ALL). However, supraphysiological doses may cause suppression of the hypothalamic-pituitary-adrenal (HPA) axis. HPA axis suppression resulting in reduced cortisol response may cause an impaired stress response and an inadequate host defence against infections, which remains a cause of morbidity and death. The exact occurrence and duration of HPA axis suppression after glucocorticoid therapy for childhood ALL are unclear. Objectives To examine the occurrence and duration of HPA axis suppression after (each cycle of) glucocorticoid therapy for childhood ALL. Search methods We searched the Cochrane Central Register of Controlled Trials (in The Cochrane Library, issue 3, 2010), MEDLINE/PubMed (from 1945 to July 2010) and EMBASE/Ovid (from 1980 to July 2010). In addition, we searched reference lists of relevant articles, conference proceedings and ongoing trial databases. Selection criteria All study designs, except case reports and patient series with fewer than 10 patients, examining the effect of glucocorticoid therapy for childhood ALL on the HPA axis function. Data collection and analysis Two review authors independently performed the study selection. One review author performed the data extraction and 'Risk of bias' assessment, which was checked by another review author. Main results We identified seven studies (total number of participants = 189), including one randomised controlled trial (RCT), which assessed the adrenal function. None of the studies assessed the HPA axis at the level of the hypothalamus, pituitary, or both. Due to substantial differences between studies, results could not be pooled. All studies had some methodological limitations. The included studies demonstrated that adrenal insufficiency occurs in nearly all patients in the first days after cessation of glucocorticoid treatment for childhood ALL. The majority of patients recovered within a few weeks, but a small amount of patients had ongoing adrenal insufficiency lasting up to 34 weeks. In the RCT, the occurrence and duration of adrenal insufficiency did not differ between the prednisolone and dexamethasone arms. In one study included in the review it appeared that treatment with fluconazole prolonged the duration of adrenal insufficiency. Authors' conclusions Based on the available evidence, we conclude that adrenal insufficiency commonly occurs in the first days after cessation of glucocorticoid therapy for childhood ALL, but the exact duration is unclear. Since no data on the level of the hypothalamus and the pituitary were available we cannot make any conclusions regarding those outcomes. Clinicians should consider prescribing glucocorticoid replacement therapy during periods of serious stress in the first weeks after cessation of glucocorticoid therapy for childhood ALL, to reduce the risk of life-threatening complications. However, more high-quality research is needed for evidence-based guidelines for glucocorticoid replacement therapy. Special attention should be paid to patients receiving fluconazole therapy, and perhaps similar antifungal drugs, as this may prolong the duration of adrenal insufficienc
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