670 research outputs found

    Measurement on Different MLI Systems Between 77 K and 4 K and their Application in Cryogenic Engineering

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    Precise thermal measurements were done on different types of large surface MLI samples under various boundary conditions. The measurements were focused on the use of MLI for large industrial plants considering quick and simple installation. The results of the measurements aim at optimising MLI parameters, which control the thermal behaviour. Practical recommendations of MLI materials and their installation are given

    A puzzling Mule Coin from the Parabita Hoard: a Material Characterisation

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    In this research, we report on the compositional, microstructural and crystallographic properties of a lead coin which has been regarded for many years as a genuine silver coin minted in the Southern Italy in the course of the 4th century BC. The material characterisation of this object allowed detecting an ancient forging technology, not previously reported, which was meant for the silvering of lead substrates The data collected have disclosed a contemporary counterfeiting procedure based on a metal coating process onto a Pb substrate. This coating has been identified as a bi-layer with a Cu innermost and an Ag outermost visible layer. As far as the coating application technique is concerned, the gathered evidence has clearly indicated that the original appearance of this artifact cannot be explained in terms of any of the established methods for the growth of an artificially silvered coating in classical antiquity. This technology is now being explained in terms of modern, fully non destructive scientific methods.Comment: 9 pages including 8 figures. To be presented at the Cavallino Archaeometry Workshop 2006, Cavallino (Lecce - Italy) - May 22-25, 200

    The impact of ventral oral graft bulbar urethroplasty on sexual life

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    Objective: To evaluate the pre- and postoperative aspects of sexual life (SL) in patients with bulbar urethral stricture who underwent ventral oral graft urethroplasty. Methods: Between 2009 and 2010, 52 men (mean age 36 years) were enrolled in our prospective study to ascertain sexual disorders before and after surgery. The validated Male Sexual Health Questionnaire-Long Form (MSHQ-LF) was completed pre- and postoperatively; the unvalidated but adapted Post-Urethroplasty Sexual Questionnaire (PUSQ) was completed postoperatively. Data were compared using the non parametric Wilcoxon test. Results: Before urethroplasty, most of the patients reported sexual disorders, in particular reduced ejaculatory stream (85%); many of them (35%) feared the risk of a postoperative worsening in the quality of SL. After urethroplasty, nobody reported a worsened erection, while most of the patients noticed a significant improvement in erection, ejaculation, relationship with their partner, sexual activity, and desire. Modifications in the scrotoperineal sensitivity were reported by 42% and 15% noticed esthetic changes without impact on SL. All patients reported an improvement in quality of life (QOL) and were satisfied with the outcome of urethroplasty. Conclusion: Urethral stricture disease may be responsible for sexual disorders that have a significant impact upon SL. Patients confessed a marked anxiety tackling urethroplasty and declared that one of their deepest fears regarded a potential further deterioration in the quality of SL. At short-term follow-up, the minimally invasive ventral graft urethroplasty does not cause sexual complications, apart from the post-ejaculation dribbling. On the contrary, this technique showed to restore SL in all its aspects

    Parameter identification through mode isolation for reaction-diffusion systems on arbitrary geometries

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    We present a computational framework for isolating spatial patterns arising in the steady states of reaction-diffusion systems. Such systems have been used to model many natural phenomena in areas such as developmental and cancer biology, cell motility and material science. In many of these applications, often one is interested in identifying parameters which will lead to a particular pattern for a given reaction-diffusion model. To attempt to answer this, we compute eigenpairs of the Laplacian on a variety of do- mains and use linear stability analysis to determine parameter values for the system that will lead to spatially inhomogeneous steady states whose patterns correspond to particular eigenfunctions. This method has previously been used on domains and surfaces where the eigenvalues and eigenfunctions are found analytically in closed form. Our contribution to this methodology is that we numerically compute eigenpairs on arbitrary domains and surfaces. Here we present examples and demonstrate that mode isolation is straightforward especially for low eigenvalues. Additionally we see that the inhomogeneous steady state can be a linear combination of eigenfunctions. Finally we show an example suggesting that pattern formation is robust on similar surfaces in cases that the surface either has or does not have a boundary

    Microalbuminuria and sRAGE in High-Risk Hypertensive Patients Treated with Nifedipine/Telmisartan Combination Treatment: A Substudy of TALENT

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    Some antihypertensive drugs have also renoprotective and anti-inflammatory properties that go beyond their effect on blood pressure. It has been suggested that microalbuminuria and glomerular filtration rate (GFR) are associated with circulating levels of the soluble form of the receptor, sRAGE (soluble receptor for advanced glycation ends-products). In the present analysis, we used data from the TALENT study to evaluate soluble receptor for advanced glycation end-products (sRAGE) plasma levels in patients with hypertension and high-cardiovascular risk-treated nifedipine and telmisartan in combination. Treatment with nifedipine-telmisartan significantly decreased mean systolic and diastolic ambulatory blood pressure and resulted in a significant increase in sRAGE plasma concentrations after 24 weeks of therapy. We concluded that in hypertensive patients with early-stage renal disease, sRAGE concentrations are not influenced by either microalbuminuria or GFR. Long-term treatment with a combination of nifedipine-telmisartan may have a beneficial effect increasing sRAGE plasma levels, thus exerting an atheroprotective and anti-inflammatory activity

    Complete removal of the lesion as a guidance in the management of patients with breast ductal carcinoma in Situ

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    Background: Considering highly selected patients with ductal carcinoma in situ (DCIS), active surveillance is a valid alternative to surgery. Our study aimed to show the reliability of post-biopsy complete lesion removal, documented by mammogram, as additional criterion to select these patients. Methods: A total of 2173 vacuum‐assisted breast biopsies (VABBs) documented as DCIS were reviewed. Surgery was performed in all cases. We retrospectively collected the reports of post‐ VABB complete lesion removal and the histological results of the biopsy and surgery. We calculated the rate of upgrade of DCIS identified on VABB upon excision for patients with post‐biopsy complete lesion removal and for those showing residual lesion. Results: We observed 2173 cases of DCIS: 408 classified as low‐grade, 1262 as intermediate‐grade, and 503 as high‐grade. The overall upgrading rate to invasive carcinoma was 15.2% (330/2173). The upgrade rate was 8.2% in patients showing mammographically documented complete removal of the lesion and 19% in patients without complete removal. Conclusion: The absence of mammographically documented residual lesion following VABB was found to be associated with a lower upgrading rate of DCIS to invasive carcinoma on surgical excision and should be considered when deciding the proper management DCIS diagnosis

    History of mammography: analysis of breast imaging diagnostic achievements over the last century

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    Breast cancer is the most common forms of cancer and a leading cause of mortality in women. Early and correct diagnosis is, therefore, essential to save lives. The development of diagnostic imaging applied to the breast has been impressive in recent years and the most used diagnostic test in the world is mammography, a low-dose X-ray technique used for imaging the breast. In the first half of the 20th century, the diagnosis was in practice only clinical, with consequent diagnostic delay and an unfavorable prognosis in the short term. The rise of organized mammography screening has led to a remarkable reduction in mortality through the early detection of breast malignancies. This historical review aims to offer a complete panorama of the development of mammography and breast imaging during the last century. Through this study, we want to understand the foundations of the pillar of radiology applied to the breast through to the most modern applications such as contrast-enhanced mammography (CEM), artificial intelligence, and radiomics. Understanding the history of the development of diagnostic imaging applied to the breast can help us understand how to better direct our efforts toward an increasingly personalized and effective diagnostic approach. The ultimate goal of imaging applied to the detection of breast malignancies should be to reduce mortality from this type of disease as much as possible. With this paper, we want to provide detailed documentation of the main steps in the evolution of breast imaging for the diagnosis of breast neoplasms; we also want to open up new scenarios where the possible current and future applications of imaging are aimed at being more precise and personalized

    tolterodine improves quality of life in patients with an overactive bladder with or without urinary incontinence a prospective multicenter study

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    AIMS: In order to analyse the effect of tolterodine on the Quality of life (QoL) of patients with overactive bladder (OB) we conducted a prospective multicentre clinical study. MATERIALS AND METHODS: Subjects were questioned at entry and 4, 12 and 24 weeks later about the number of micturitions and incontinent and urgency episodes/day, using a micturition diary. The mean volume voided per micturition and the number of pads used per day was also recorded. The QoL was measured using the Kings Health Questionnaire (KHQ) and the Incontinence Impact Questionnaire (IIQ). A total of 179 patients entered the study: 59 dropped out (4 due to lack of efficacy, 10 due to adverse events, 25 because of lack of interest in the study/other reason and 20 were lost at follow up), leaving 120 patients for analysis. One hundred and eight patients (90%) were female, their mean age was 56.5 years (SD 11.2); 87 had never received treatment for OB/UI (80.6%) and their mean weight was 70.0 Kg (SD 12.7). RESULTS: The mean number of micturitions/day was 9.3 at trial entry and it decreased to 6.8 by the end of the study. The corresponding values for the number of urge episodes, incontinence episodes and number of pads used per day were 3.5, 2.7 and 1.2 and 0.8, 0.9 and 0.4 respectively. The mean volume voided per micturition increased from 146 ml. to 178 ml. All the differences between trial entry and end of study values were statistically significant (p<0.05). Considering the results of the KHQ, the values of all the different areas/domini (?) decreased markedly and in a statistically significant way between the start of treatment and the end of study evaluations. Similar findings emerged when we considered values of the IIQ. The decrease was constant and marked during the first three months and remained constant thereafter. CONCLUSIONS: This study, conducted in a population of subjects with dry and wet OB, shows that tolterodine given for six months lowers the frequency of urgency episodes and incontinence episodes without troublesome adverse effects. These clinical effects are mirrored in the QoL, KHQ and IIQ questionnaire scores, which improved by about 50% over the same period

    Disposable versus reusable ureteroscopes. A prospective multicenter randomized comparison

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    Introduction: To compare reusable and disposable flexible ureteroscopes in terms of efficacy and safety for patients undergoing RIRS, with specific reference to post-operative complications and infection rates. Materials and methods: Patients with a renal stone eligible for RIRS were enrolled in this multicenter, randomized, clinical trial study. Patients were randomized into two groups: group A (90 patients) underwent RIRS with a reusable flexible ureteroscope and group B (90 patients) were treated with a disposable one. Results: The patients’ demographics, stones features and preoperative urine cultures were comparable between the groups. The SFRs were not significantly different (86,6% and 90,0% for group A and group B respectively, p = 0.11) and the mean cost for each procedure was comparable (2321 € in group A vs 2543 € in group B, p = 0.09). However, the days of hospitalization and of antibiotic therapy were higher in group A (p ≤ 0.05). The overall complication rate in group A was 8.8% whilst in group B it was 3.3% (p ≤ 0.05); in particular, group A exhibited a greater number of major complications (Clavien score IIIa-V). The overall postoperative infections rate was 16.6% in group A and 3.3% in group B (p ≤ 0.05). Furthermore, none of the patients in group B developed urosepsis or had a positive blood culture, while 3 patients in group A did (p < 0.05). Conclusions: The use of disposable ureteroscopes is characterized by significantly lower post-operative complications and infection rates, while having comparable costs and SFRs vis à vis reusable ureteroscopes

    A comparison among PCNL, Miniperc and Ultraminiperc for lower calyceal stones between 1 and 2 cm: A prospective, comparative, multicenter and randomised study

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    Background: Conventional Percutaneous Lithotripsy (PCNL) has been an effective, successful and easy approach for especially > 1 cm sized calyceal stones however risks of complications and nephron loss are inevitable. Our aim is to compare the efficacy and safety of PCNL, MiniPerc (MP) and UltraMiniPerc (UMP) for lower calyceal stones between 1 and 2 cm with a multicenter prospective randomized study. Methods: Between January 2015 and June 2018, 132 consecutive patients with single lower calyceal stone were enrolled. Patients were randomized in three groups; A: PCNL; B: MP; C: UMP. 44 patients for the Group A, 47 for Group B and 41 for Group C. Exclusion criterias were the presence of coagulation impairments, age of < 18 or > 75, presence of infection or serious comorbidities. Patients were controlled with computerized tomography scan after 3 months. A negative CT or an asymptomatic patient with stone fragments < 3 mm size were the criteria to assess the stone-free status. Patient characteristics, stone free rates (SFR) s, complications and re-treatment rates were analyzed. Results: The mean stone size were 16.38, 16.82 and 15.23 mm respectively in Group A, B and C(p = 0.34). The overall SFR was significantly higher in Group A (86.3%) and B (82.9%) as compared to Group C (78%)(p < 0.05). The re-treatment rate was significantly higher in Group C (12.1%) and complication rates was higher in Group A (13.6%) as compared to others(p < 0.05). The hospitalization was significantly shorter in Group C compared to Group A (p = 0.04). Conclusions: PCNL and MP showed higher efficacy than UMP to obtain a better SFR. Auxiliary and re-treatment rates were higher in UMP. On the other hand for such this kind of stones PCNL had more complications. Overall evaluation favors MP as a better indication in stones 1-2 cm size
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