298 research outputs found
Electron localization and possible phase separation in the absence of a charge density wave in single-phase 1T-VS
We report on a systematic study of the structural, magnetic and transport
properties of high-purity 1T-VS powder samples prepared under high
pressure. The results differ notably from those previously obtained by
de-intercalating Li from LiVS. First, no Charge Density Wave (CDW) is found
by transmission electron microscopy down to 94 K. Though, \textit{ab initio}
phonon calculations unveil a latent CDW instability driven by an acoustic
phonon softening at the wave vector (0.21,0.21,0)
previously reported in de-intercalated samples. A further indication of latent
lattice instability is given by an anomalous expansion of the V-S bond distance
at low temperature. Second, infrared optical absorption and electrical
resistivity measurements give evidence of non metallic properties, consistent
with the observation of no CDW phase. On the other hand, magnetic
susceptibility and NMR data suggest the coexistence of localized moments with
metallic carriers, in agreement with \textit{ab initio} band structure
calculations. This discrepancy is reconciled by a picture of electron
localization induced by disorder or electronic correlations leading to a phase
separation of metallic and non-metallic domains in the nm scale. We conclude
that 1T-VS is at the verge of a CDW transition and suggest that residual
electronic doping in Li de-intercalated samples stabilizes a uniform CDW phase
with metallic properties.Comment: 22 pages, 10 Figures. Full resolution pictures available at
http://journals.aps.org/prb/abstract/10.1103/PhysRevB.89.23512
First cases of combined full robotic partial nephrectomy and colorectal resections: Results and new perspectives
Background: Nowadays the robotic platform is widespread in general surgery, urology, and gynecology. Combined surgery may represent an alternative to sequential procedures and it allows the treatment, at the same time, of coexisting lesions; in this perspective, full-robotic multiorgan surgery is starting to gain interest from surgeons worldwide. Methods: Between April and June 2019, two patients presenting with synchronous colorectal and kidney cancers underwent, respectively, full-robotic right colectomy with right partial nephrectomy and anterior rectal resection with left partial nephrectomy. Surgeries were performed by both the general surgery and urology team. Results: No intraoperative complications were registered and the postoperative course was uneventful in both cases. Conclusions: Combined multiple organ surgery with full robotic technique is safe and offers oncological adequate results. A multi-team surgical pre-planning is mandatory to reduce invasiveness and operative time. To the best of our knowledge, these are the first reports of full robotic partial nephrectomy combined with colorectal procedures
CT angiography for the assessment of EVAR complications: a pictorial review
Endovascular aneurysm repair (EVAR) is a minimally invasive treatment proposed as an alternative to open repair in patients with abdominal aortic aneurysms. EVAR consists in a stent-graft placement within the aorta in order to exclude the aneurysm from arterial circulation and reduce the risk of rupture. Knowledge of the various types of devices is mandatory because some stents/grafts are more frequently associated with complications. CT angiography is the gold standard diagnostic technique for preprocedural planning and postprocedural surveillance. EVAR needs long-term follow-up due to the high rate of complications. Complications can be divided in endograft device-related and systemic complications. The purpose of this article is to review the CT imaging findings of EVAR complications and the key features for the diagnosis
Beam-induced damage on diffractive hard X-ray optics
Beam-induced damage on diffractive hard X-ray optics is studied by means of X-ray diffraction and scanning electron microscopy
Lipid composition optimization in spray congealing technique and testing with curcumin-loaded microparticles
Spray-congealing, a technique based on the fast solidification of sprayed molten lipids, is considered a novel strategy to encapsulate natural products. Among others, it is a safe, low cost, fast and reproducible technique, with rising interest for several applications (e.g. food applications). One of the key parameters for the application of this technique is the lipid solidification temperature, which can be modulated by optimizing the lipid composition. In this work, three lipid components (beeswax, carnauba wax, and medium-chain triglycerides (Miglyol 812)) were selected, and the mixture composition modelled using a simplex-centroid experimental design. Three different lipid compositions were chosen to validate the proposed model, then tested in the preparation of curcumin-loaded microparticles (1.5%, w/w). The produced microparticles were analysed in terms of colour, morphology, particle size, encapsulation efficiency and load, physicochemical, crystalline, and thermal properties. Results evidenced that microparticle's properties, including encapsulation efficiency, vary according to the used lipid mixture, supporting their tailoring role. This fact brings advantages in the design of microencapsulation systems based on spray congealing processes, broadening their applicability. Moreover, lipid composition optimisation was proved to be an important tool to precede the development of spray-congealing applications.info:eu-repo/semantics/publishedVersio
Prevention of skin reactions due to teletherapy in women with breast cancer: a comprehensive review
One of the possible courses of cancer treatment is teletherapy, and one of the most important adverse side effects are skin reactions, an ailment more commonly called radiodermatitis. The main purpose of this study is to analyze knowledge of the evidence about topical products used in the prevention of radiodermatitis, to support care delivery to women with breast cancer during teletherapy. The research method used here is the comprehensive literature review. Four databases were used to select the bibliography. The sample consists of 15 articles. The data shows that, among the topical products analyzed here, Calendula, corticosteroids and Xclair have shown significant protective effects, underlining their actions. The lack of articles published in Brazil highlights the need for further research in this area, seeking better care quality through the use of products with scientifically proven efficiency.Teleterapia está entre las modalidades de tratamiento para el cáncer y uno de sus principales efectos adversos son reacciones de la piel, comúnmente llamado radiodermatitis. Este estudio objetivó analizar el conocimiento acerca de los productos tópicos utilizados para la prevención de la radiodermatitis que justifiquen la atención en teleterapia en mujeres con cáncer de mama. Se adoptó como método de investigación la revisión integradora de la literatura. Para la selección de los artÃculos se utilizaron cuatro bases de datos. La muestra fue constituida por 15 artÃculos. Los datos muestran que entre los productos tópicos analizados la caléndula, esteroides y Clair X tuvo un efecto protector significativo, destacando asà por sus acciones. La ausencia de artÃculos publicados en Brasil se centra en la necesidad de seguir investigando para mejorar la calidad de la atención mediante el uso de productos con una eficacia cientÃficamente probada.Dentre as modalidades de tratamento para o câncer está a teleterapia, e um dos principais efeitos adversos dessa modalidade são as reações de pele, comumente chamadas radiodermatites. O presente estudo teve como objetivo analisar o conhecimento sobre as evidências acerca de produtos tópicos, utilizados na prevenção de radiodermatite, que fundamente o cuidado em teleterapia direcionado a mulheres com câncer de mama. Adotou-se como método de pesquisa a revisão integrativa da literatura. Para a seleção da bibliografia utilizaram-se quatro bases de dados. A amostra constitui-se de 15 artigos. Os dados demonstram que, dentre os produtos tópicos analisados, a calêndula, os corticoesteroides e o Xclair tiveram efeito protetor significante, destacando-se, assim, pelas suas ações. A ausência de artigos publicados no Brasil mostra a necessidade de mais pesquisas nessa área, visando a melhor qualidade na assistência a mulheres com câncer de mama, por meio da utilização de produtos com eficácia comprovada cientificamente
Scaffold proteins LACK and TRACK as potential drug targets in kinetoplastid parasites: Development of inhibitors
Parasitic diseases cause similar to 500,000 deaths annually and remain a major challenge for therapeutic development. Using a rational design based approach, we developed peptide inhibitors with anti-parasitic activity that were derived from the sequences of parasite scaffold proteins LACK (Leishmania's receptor for activated C-kinase) and TRACK (Trypanosoma receptor for activated C-kinase). We hypothesized that sequences in LACK and TRACK that are conserved in the parasites, but not in the mammalian ortholog, RACK (Receptor for activated C-kinase), may be interaction sites for signaling proteins that are critical for the parasites' viability. One of these peptides exhibited leishmanicidal and trypanocidal activity in culture. Moreover, in infected mice, this peptide was also effective in reducing parasitemia and increasing survival without toxic effects. The identified peptide is a promising new anti-parasitic drug lead, as its unique features may limit toxicity and drug-resistance, thus overcoming central limitations of most anti-parasitic drugs. (C) 2016 The Authors. Published by Elsevier Ltd on behalf of Australian Society for Parasitology.National Institutes of HealthStanford Univ, Sch Med, Dept Chem & Syst Biol, Stanford, CA 94305 USAUniv Sao Paulo, Inst Quim, Dept Bioquim, BR-05508 Sao Paulo, SP, BrazilMcGill Univ, Res Inst, Natl Reference Ctr Parasitol, Montreal, PQ, CanadaUniv Autonoma Yucatan, Ctr Invest Reg Dr Hideyo Noguchi, Parasitol Lab, Merida, Yucatan, MexicoStanford Univ, Biomat & Adv Drug Delivery Lab, Stanford, CA 94305 USAUniv Estadual Campinas, Inst Chem, Campinas, SP, BrazilUniv Fed Sao Paulo, Dept Ciencias Biol, Campus Diadema, Sao Paulo, BrazilMcGill Univ, Inst Parasitol, Quebec City, PQ, CanadaMcGill Univ, Ctr Host Parasite Interact, Quebec City, PQ, CanadaUniv Fed Sao Paulo, Dept Ciencias Biol, Campus Diadema, Sao Paulo, BrazilNIH: TW008781-01C-IDEANIH: AI078505Web of Scienc
Powder diffraction studies on proteins: An overview of data collection approaches
Following the seminal work of Von Dreele, high quality powder X-ray diffraction studies on proteins are being established as a valuable complementary technique to single-crystal measurements. Several studies using a variety of experiments approaches have been reported in the literature, including high-resolution studies employing parallel beam geometry and high intensity measurements using position sensitive detectors. The choice of the optimum instrumental configuration depends on a number of competing factors such as the amount of sample available, its radiation sensitivity, and the quality of the data required for data analysis, e.g. angular resolution, the extent of the data in d-spacing, or the number of patterns required to explore the protein’s behaviour at different temperatures, or under different crystallisation conditions, etc. Here we discuss several advantages and disadvantages of different data collection methods followed for selected examples of small proteins
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