103 research outputs found
A Case of Atypical McCune-Albright Syndrome with Vaginal Bleeding
Abstract
Background: McCune-Albright syndrome (MAS) is a rare non-inherited disorder characterized by
the clinical triad of precocious puberty, cafe-au-lait skin lesions, and fibrous dysplasia of bone.
Case Presentation: We report a girl with MAS, presenting initially with vaginal bleeding at the age
of 17 months. Ultrasonography revealed unilateral ovarian cysts and ureteral and ovarian
enlargement. Considering the clinical and paraclinical findings, the patient diagnosed as a case of
gonadotropin-independent precocious puberty was treated with medroxy-progestrone acetate
(MPA) for three months. During the follow up, recurrent episodes of bleeding, ovarian activation
and cyst formation, as well as breast size development were reported. At the age of 5.5 years,
fibrous dysplasia was detected, which in coexistence with precocious puberty confirmed the
diagnosis of MAS. The patient had no cafe-au-lait skin macles during follow up.
Conclusion: Considering that clinical manifestations of MAS appear later in the course of recurrent
periods of ovarian activation and cyst formation, a careful clinical observation and follow up of
patients is necessary and the diagnosis of MAS must be kept in mind in cases with gonadotropinindependent
precocious puberty
Influence of the bias voltage on the structure and the tribological performance of nanoscale multilayer C/Cr PVD coatings
Nanoscale multilayer C/Cr coatings have been deposited by utilising the combined steered cathodic arc/unbalanced magnetron sputtering technique. The coating microstructure and tribological performance have been investigated as a function of the bias voltage, ranging from U-b=-65 to -350 V. The XRD results revealed that C/Cr coatings are amorphous at low U-b, but became more crystalline when the Ub increased to -350 V. High-resolution XTEM analysis indicated coating densification and smoothening as well as formation of novel amorphous nanostructure, in which carbon-rich clusters are surrounded by a Cr-rich matrix, leading to the formation of self-organised multilayer structure as the bias voltage was increased from -65 to -350 V. An increase of the bias voltage from -65 to -350 V resulted in an increase in the hardness from 8 to 25 CiPa and Young's modulus, E from 186 to 319 GPa. A pin-on-disc test showed that the friction coefficient was reduced from 0.22 to 0.16 when the bias voltage was increased from -65 to -95 V However, a further increase in the bias voltage to -350 V led to an increase in the friction coefficient to 0.31. The lowest wear coefficient K(c)similar to6.25 x 10(-17) m(3) N-1 m(-1) was achieved at U-b = - 120 V. Standard HSS drills, 8 mm in diameter, coated with C/Cr have been tested using solution annealed AISI 304 stainless steel as the work piece material. An improvement of the lifetime by a factor of similar to9 has been achieved as compared to the uncoated tools. In this test, the C/Cr coating outperformed a number of commercially available PVD coatings, such as TiCN, TiAlCrN and showed similar performance to TiAlCrYN. (C) 2004 Elsevier B.V. All rights reserved
Tribological properties of unbalanced magnetron sputtered nano-scale multilayer coatings TiAlN/VN and TiAlCrYN deposited on plasma nitrided steels
Unbalanced magnetron sputtered multilayer coatings TiAlN/VN and TiAlCrYN grown on pulse plasma nitriding pre-treated low alloy steel P20 have been characterised by using X-ray diffraction (XRD), scanning electron microscope (SEM), micro-indentation, scratch and pin-on-dise wear tests. A 160-mu m-thick nitrided case was formed on the steel surface containing a pure Fe3N and Fe4N compound layer and showing hardness up to 8.5 GPa, which led to improved load bearing ability and adhesion behaviour of the coating-substrate system. The coatings deposited on non-nitrided P20 showed poor adhesion and severe cracking and spalling wear. In contrast, the TiAlN/VN and TiAlCrYN deposited on nitrided substrates showed only mild polishing and oxidation wear mechanisms and extremely low wear coefficients in the scales of 10(-17) and 10(-16) m(3) N-1 m(-1), respectively. In drilling solution treated 304 austenite stainless steel, the TiAlN/VN-coated drills showed a lifetime 50% longer than TiAlN-coated drills. Plasma nitriding pre-treatment led to further increases of lifetime by 33%. (c) 2004 Elsevier B.V. All rights reserved
Uterine Fibroid Embolisation for Symptomatic Uterine Fibroids: A Survey of Clinical Practice in Europe
Item does not contain fulltextPURPOSE: To assess current uterine fibroid embolisation (UFE) practice in European countries and determine the clinical environment for UFE in different hospitals. MATERIAL AND METHODS: In May 2009, an invitation for an online survey was sent by e-mail to all members of the Cardiovascular and Interventional Radiologic Society of Europe, representing a total number of 1,250 different candidate European treatment centres. The survey covered 21 questions concerning local UFE practice. RESULTS: A total of 282 respondents completed the questionnaire. Fifteen questionnaires were excluded because they were doubles from centres that had already returned a questionnaire. The response rate was 267 of 1,250 centres (21.4%). Ninety-four respondents (33%) did not perform UFE and were excluded, and six centres were excluded because demographic data were missing. The remaining 167 respondents from different UFE centres were included in the study. Twenty-six percent of the respondents were from the United Kingdom (n = 43); 16% were from Germany (n = 27); 11% were from France (n = 18); and the remaining 47% (n = 79) were from other European countries. Most centres (48%, n = 80) had 5 to 10 years experience with UFE and performed 10 to 50 procedures annually (53% [n = 88]) of respondents). Additional demographic data, as well as specific data on referral of patients, UFE techniques used, and periprocedural and postprocedural, care will be provided. CONCLUSION: Although UFE as an alternative treatment for hysterectomy or myomectomy is widespread in Europe, its impact on the management of the patient with symptomatic fibroids seems, according to the overall numbers of UFE procedures, somewhat disappointing. Multiple factors might be responsible for this observation
Hemodynamic predictors of aortic dilatation in bicuspid aortic valve by velocity-encoded cardiovascular magnetic resonance
<p>Abstract</p> <p>Background</p> <p>Congenital Bicuspid Aortic Valve (BAV) is a significant risk factor for serious complications including valve dysfunction, aortic dilatation, dissection, and sudden death. Clinical tools for identification and monitoring of BAV patients at high risk for development of aortic dilatation, an early complication, are not available.</p> <p>Methods</p> <p>This paper reports an investigation in 18 pediatric BAV patients and 10 normal controls of links between abnormal blood flow patterns in the ascending aorta and aortic dilatation using velocity-encoded cardiovascular magnetic resonance. Blood flow patterns were quantitatively expressed in the angle between systolic left ventricular outflow and the aortic root channel axis, and also correlated with known biochemical markers of vessel wall disease.</p> <p>Results</p> <p>The data confirm larger ascending aortas in BAV patients than in controls, and show more angled LV outflow in BAV (17.54 ± 0.87 degrees) than controls (10.01 ± 1.29) (p = 0.01). Significant correlation of systolic LV outflow jet angles with dilatation was found at different levels of the aorta in BAV patients STJ: r = 0.386 (N = 18, p = 0.048), AAO: r = 0.536 (N = 18, p = 0.022), and stronger correlation was found with patients and controls combined into one population: SOV: r = 0.405 (N = 28, p = 0.033), STJ: r = 0.562 (N = 28, p = 0.002), and AAO r = 0.645 (N = 28, p < 0.001). Dilatation and the flow jet angle were also found to correlate with plasma levels of matrix metallo-proteinase 2.</p> <p>Conclusions</p> <p>The results of this study provide new insights into the pathophysiological processes underlying aortic dilatation in BAV patients. These results show a possible path towards the development of clinical risk stratification protocols in order to reduce morbidity and mortality for this common congenital heart defect.</p
Novel aspects of the pathogenesis of aneurysms of the abdominal aorta in humans
Aneurysm of the abdominal aorta (AAA) is a particular, specifically localized form of atherothrombosis, providing a unique human model of this disease. The pathogenesis of AAA is characterized by a breakdown of the extracellular matrix due to an excessive proteolytic activity, leading to potential arterial wall rupture. The roles of matrix metalloproteinases and plasmin generation in progression of AAA have been demonstrated both in animal models and in clinical studies. In the present review, we highlight recent studies addressing the role of the haemoglobin-rich, intraluminal thrombus and the adventitial response in the development of human AAA. The intraluminal thrombus exerts its pathogenic effect through platelet activation, fibrin formation, binding of plasminogen and its activators, and trapping of erythrocytes and neutrophils, leading to oxidative and proteolytic injury of the arterial wall. These events occur mainly at the intraluminal thrombus–circulating blood interface, and pathological mediators are conveyed outwards, where they promote matrix degradation of the arterial wall. In response, neo-angiogenesis, phagocytosis by mononuclear cells, and a shift from innate to adaptive immunity in the adventitia are observed. Abdominal aortic aneurysm thus represents an accessible spatiotemporal model of human atherothrombotic progression towards clinical events, the study of which should allow further understanding of its pathogenesis and the translation of pathogenic biological activities into diagnostic and therapeutic applications
Technical Design Report EuroGammaS proposal for the ELI-NP Gamma beam System
The machine described in this document is an advanced Source of up to 20 MeV
Gamma Rays based on Compton back-scattering, i.e. collision of an intense high
power laser beam and a high brightness electron beam with maximum kinetic
energy of about 720 MeV. Fully equipped with collimation and characterization
systems, in order to generate, form and fully measure the physical
characteristics of the produced Gamma Ray beam. The quality, i.e. phase space
density, of the two colliding beams will be such that the emitted Gamma ray
beam is characterized by energy tunability, spectral density, bandwidth,
polarization, divergence and brilliance compatible with the requested
performances of the ELI-NP user facility, to be built in Romania as the Nuclear
Physics oriented Pillar of the European Extreme Light Infrastructure. This
document illustrates the Technical Design finally produced by the EuroGammaS
Collaboration, after a thorough investigation of the machine expected
performances within the constraints imposed by the ELI-NP tender for the Gamma
Beam System (ELI-NP-GBS), in terms of available budget, deadlines for machine
completion and performance achievement, compatibility with lay-out and
characteristics of the planned civil engineering
A randomized controlled trial of vitamin D supplementation on perinatal depression: in Iranian pregnant mothers
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