801 research outputs found
New Ultra Small Iron-Oxide Nanoparticles with Titanium-Carbamate Coating: Preparation and Magnetic Properties
This work deals with the preparation and chemical characterization of new Ultra-Small Iron-Oxide Superparamagnetic
Nanoparticles (USPIONs) functionalized with Titanium-carbamate. The synthesis was performed
starting from oleate-coated and 2-pyrrolidone-coated USPIONs having a maghemite ( -Fe2O3) and
magnetite (Fe3O4) crystalline core, respectively. Zero-field-cooled (ZFC) and field-cooled (FC) magnetic susceptibility
curves as well as the magnetization behavior as a function of temperature are reported and discussed
in view of the superparamagnetic properties and coating effect of these new magnetic nanoparticles.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3545
Unexpected Metastasis of High Grade Serous Ovarian Cancer to Breast: Case Report and Literature Review
Introduction: Metastasis of ovarian serous carcinoma to breast and/or axillary lymph nodes represents an unusual event. Nevertheless, their detection and distinction from mammary carcinoma are of huge clinical importance because the treatment and prognosis diverge significantly. Case presentation: We report a case of a 47 year-old Caucasian female patient with unforeseen metastasis to the breast and to axillary lymph nodes due to ovarian serous carcinoma. Conclusion: In patients with history of OSC who present with axillary or breast mass, an accurate histological diagnosis should be obtained since this has a great impact on treatment outcomes
Polymer-dispersed liquid crystal elastomers
The need for mechanical manipulation during the curing of conventional liquid crystal elastomers diminishes their applicability in the field of shape-programmable soft materials and future applications in additive manufacturing. Here we report on polymer-dispersed liquid crystal elastomers, novel composite materials that eliminate this difficulty. Their thermal shape memory anisotropy is imprinted by curing in external magnetic field, providing for conventional moulding of macroscopically sized soft, thermomechanically active elastic objects of general shapes. The binary soft-soft composition of isotropic elastomer matrix, filled with freeze-fracture-fabricated, oriented liquid crystal elastomer microparticles as colloidal inclusions, allows for fine-tuning of thermal morphing behaviour. This is accomplished by adjusting the concentration, spatial distribution and orientation of microparticles or using blends of microparticles with different thermomechanical characteristics. We demonstrate that any Gaussian thermomechanical deformation mode (bend, cup, saddle, left and right twist) of a planar sample, as well as beat-like actuation, is attainable with bilayer microparticle configurations
Uno studio sulla Percezione della Chimica e sulla Cultura chimico-scientifica nei giovani italiani
Questo breve articolo riguarda uno studio condotto nell’ambito della tesi
triennale in Chimica di uno degli autori, Giulia Chiocca, intitolato: “A
study of the perception of Chemistry in young generations and of their
chemical/scientific knowledge” (Tesi di Laurea triennale in Chimica,
Università di Pisa: 17 settembre 2015). Un test a risposte multiple e a
risposte aperte è stato costruito appositamente per indagare quale sia la
percezione della Chimica e la conoscenza dei concetti fondamentali della
Chimica da parte di giovani con età dai 18 ai 30 anni. Il test è stato
distribuito sui canali di comunicazione maggiormente utilizzati dai giovani,
ovvero i social network. Da una analisi preliminare dei dati raccolti su un
campione di 431 ragazzi è possibile evidenziare alcune importanti
considerazioni, che sono oggetto di questo lavoro
1H NMR relaxometry in the TGBA* and TGBC* phases
Recent results obtained by 1H NMR relaxometry of liquid crystals having twist grain boundary (TGB) phases are here reviewed. In
particular, three chiral rod-like lactate derivative mesogens were investigated. In the isotropic phase, three-exponential magnetization
decay was observed in all cases and the three distinct spin-lattice relaxation times (T1) were assigned to three specific molecular groups
of these molecules. In the TGBA* and TGBC* phases the magnetization decay is mono-exponential and the main features of the 1H NMR
dispersion curves analyzed through a global target fitting procedure in terms of specific molecular and collective dynamics are discussed
Deficiency of histone variant macroH2A1.1 is associated with sexually dimorphic obesity in mice
Obesity has a major socio-economic health impact. There are profound sex differences in adipose tissue deposition and obesity-related conditions. The underlying mechanisms driving sexual dimorphism in obesity and its associated metabolic disorders remain unclear. Histone variant macroH2A1.1 is a candidate epigenetic mechanism linking environmental and dietary factors to obesity. Here, we used a mouse model genetically depleted of macroH2A1.1 to investigate its potential epigenetic role in sex dimorphic obesity, metabolic disturbances and gut dysbiosis. Whole body macroH2A1 knockout (KO) mice, generated with the Cre/loxP technology, and their control littermates were fed a high fat diet containing 60% of energy derived from fat. The diet was administered for three months starting from 10 to 12 weeks of age. We evaluated the progression in body weight, the food intake, and the tolerance to glucose by means of a glucose tolerance test. Gut microbiota composition, visceral adipose and liver tissue morphology were assessed. In addition, adipogenic gene expression patterns were evaluated in the visceral adipose tissue. Female KO mice for macroH2A1.1 had a more pronounced weight gain induced by high fat diet compared to their littermates, while the increase in body weight in male mice was similar in the two genotypes. Food intake was generally increased upon KO and decreased by high fat diet in both sexes, with the exception of KO females fed a high fat diet that displayed the same food intake of their littermates. In glucose tolerance tests, glucose levels were significantly elevated upon high fat diet in female KO compared to a standard diet, while this effect was absent in male KO. There were no differences in hepatic histology. Upon a high fat diet, in female adipocyte cross-sectional area was larger in KO compared to littermates: activation of proadipogenic genes (ACACB, AGT, ANGPT2, FASN, RETN, SLC2A4) and downregulation of antiadipogenic genes (AXIN1, E2F1, EGR2, JUN, SIRT1, SIRT2, UCP1, CCND1, CDKN1A, CDKN1B, EGR2) was detected. Gut microbiota profiling showed increase in Firmicutes and a decrease in Bacteroidetes in females, but not males, macroH2A1.1 KO mice. MacroH2A1.1 KO mice display sexual dimorphism in high fat diet-induced obesity and in gut dysbiosis, and may represent a useful model to investigate epigenetic and metabolic differences associated to the development of obesity-associated pathological conditions in males and female
Etching kinetics of nanodiamond seeds in the early stages of CVD diamond growth
We present an experimental study on the etching of detonation nanodiamond (DND) seeds during typical microwave chemical vapor deposition (MWCVD)conditions leading to ultra-thin diamond film formation, which is fundamental for many technological applications. The temporal evolution of the surface density of seeds on the Si(100) substrate has been assessed by scanning electron microscopy (SEM). The resulting kinetics have been explained in the framework of a model based on the effect of the particle size, according to the Young-Laplace equation,on both chemical potential of carbon atoms in DND and activation energy of the reaction with atomic hydrogen. The model describes the experimental kinetics of seeds' disappearance by assuming that nanodiamond particles with a size smaller than a "critical radius", r*, are etched away while those greater than r* can grow. Finally, the model allows to estimate the rate coefficients for growth and etching from the experimental kinetics
Dysfunction of the magnocellular stream in Alzheimer's disease evaluated by pattern electroretinograms and visual evoked potentials
Background: Visuo-spatial disturbances could represent a clinical feature of early stage Alzheimer's disease (AD). The magnocellular (M) pathway has anatomo-physiological characteristic which make it more suitable for detecting form, motion and depth compared with parvocellular one (P). Objective: Aim of our study was to evaluate specific visual subsystem involvement in a group of AD patients, recording isoluminant chromatic and luminance pattern electroretinograms and pattern visual evoked potentials. Material and methods: data were obtained from 15 AD patients (9 females and 6 males, mean age \ub1 1SD: 77.6 \ub1 4.01 years) not yet undergoing any treatment, and from 10 age-matched healthy controls. Diagnosis of probable AD was clinically and neuroradiologically established. PERGs were recorded monocularly in response to equiluminant red-green (R-G), blue-yellow (B-Y) and luminance yellow-black (Y-Bk) horizontal square gratings of 0.3. c/deg and 90% contrast, reversed at 1. Hz. VEPs were recorded in response to full-field (14 deg) equiluminant chromatic R-G, B-Y and luminance Y-Bk sinusoidal gratings of 2. c/deg, presented in onset (300. ms)-offset (700. ms) mode, at the contrast levels of 90%. Results: All data were retrieved in terms of peak-amplitude and latency and assessed using the Student's t-test for paired data. Temporal differences of PERGs and VEPs, evoked by Y-Bk grating in AD patients compared with controls, suggest a specific impairment of the magnocellular stream. Conclusions: Our study support the hypothesis that the impairment of the PERGs and VEPs arising from the magnocellular streams of visual processing may indicate a primary dysfunction of the M-pathways in AD
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