116 research outputs found

    Asymptotic analysis of the Navier-Stokes equations in a curved domain with a non-characteristic boundary

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    We consider the Navier-Stokes equations of an incompressible fluid in a three dimensional curved domain with permeable walls in the limit of small viscosity. Using a curvilinear coordinate system, adapted to the boundary, we construct a corrector function at order εj\varepsilon^{j}, j=0,1j = 0, 1, where ε\varepsilon is the (small) viscosity parameter. This allows us to obtain an asymptotic expansion of the Navier-Stokes solution at order εj\varepsilon^{j}, j=0,1j = 0, 1, for ε\varepsilon small . Using the asymptotic expansion, we prove that the Navier-Stokes solutions converge, as the viscosity parameter tends to zero, to the corresponding Euler solution in the natural energy norm. This work generalizes earlier results in [14] or [26], which discussed the case of a channel domain, while here the domain is curved

    Psychiatric consultations and the management of associated comorbid medical conditions in a regional referral hospital

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    Background. Psychiatrists are often called upon to evaluate patients with a medical condition and psychiatric symptoms, either as a complication thereof or initial presenting symptoms. There are often grey areas with regard to neuropsychiatric disorders in which psychiatrists and specialists from other clinical disciplines would need to co-manage or share ideas on the comprehensive treatment of a presenting patient. Objectives. This study was undertaken to provide a demographic and clinical profile of all patients consulted by the consultation-liaison psychiatry (CLP) service at the Helen Joseph Hospital (HJH) in Johannesburg, and to describe the clinical management of patients admitted with a diagnosis of a mental disorder associated with a comorbid medical condition, including delirium, dementia and a mood or psychotic disorder due to a general medical condition. Methods. A retrospective record review of all patients referred to the HJH CLP team over a 6-month period. Results. A total of 884 routine and emergency consultations were done for 662 patients (males n=305; females n=357) between the ages of 13 and 90 years who were referred from various other clinical departments. The most common documented reason for referral was a request for assessment (n=182; 27.5%), which consisted of mental state assessment, reconsultation and assessing capacity. A total of 63 patients (10.0% of cases consulted) were admitted to either the medical or psychiatric wards with a confirmed diagnosis of delirium, dementia and/or a mood or psychotic disorder due to a general medical condition (although admission wards were identified in 55 files only). The medical wards admitted the majority (n=37; 67.3%) mostly for delirium (n=28; 50.9%). HIV was identified as the most common systemic aetiological factor (n=23; 67.7%). Conclusion. In this study, a female patient between 31 and 45 years of age was slightly more likely to be referred to the HJH CLP service for assessment, and was more likely to be managed in the medical wards for delirium, which was most often associated with HIV/AIDS. The study highlighted the need for development of guidelines to facilitate adequate and effective use of this service for the local practice of CLP in a general specialist referral hospital like HJH, which would cover the following: clinical management; training needs; and administrative procedures

    A drug safety evaluation of abiraterone acetate in the treatment of prostate cancer

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    Introduction: To evaluate the safety profile characteristics of abiraterone acetate (AA) in the treatment of metastatic prostate cancer (mPCa). Areas covered: In this literature review the authors evaluate safety data from phase III trials investigating the combination of abiraterone acetate plus prednisone (AAP) in patients with metastatic prostate cancer. In particular, the aim was to clarify its toxicity profile, long-term exposure impact, and the correlation with general health-related quality of life (HRQoL). Expert opinion: Based on the studies reviewed, it appears that abiraterone acetate has favourable outcomes, is effective and well tolerated, mostly in asymptomatic or slightly symptomatic patients, and has recognised toxicity profile characteristics. Incidence of adverse events (AEs), such as mineralocorticoid- and corticosteroid-releated AEs, and hepatotoxicity is well known and widely described. Understanding the toxicity profile of AA could assist decision-making in clinical practice

    The role of immune PSA complex (iXip) in the prediction of prostate cancer

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    Purpose: To analyse the performance of iXip in the prediction of prostate cancer (PCa) and high-grade PCa. Methods: A consecutive series of men undergoing MRI/FUSION prostate biopsies were enrolled in one centre. Indications for prostate biopsy included abnormal prostate-specific antigen (PSA) levels (PSA>4 ng/ml) and/or abnormal digital rectal examination (DRE) and/or abnormal MRI. All patients underwent the evaluation of serum PSA-IgM concentration and the iXip ratio was calculated. Accuracy iXip for the prediction of PCa was evaluated using multivariable binary regression analysis and receiver operator characteristics (ROC) curves. Results: Overall 160 patients with a median age of 65 (62/73) years were enrolled. Overall, 42% patients were diagnosed with PCa and 75% of them had high-grade cancer (Epstein ≥ 3). Patients with PCa were older and presented higher PSA levels, higher PIRADS scores and lower prostate volumes (PVs). On ROC analysis iXip presented an area under the curve (AUC) of 0.57 in the prediction of PCa and of 0.54 for the prediction of high-grade PCa. Conclusions: In our experience, immune PSA complexes are not predictors of PCa. iXip analysis should not be included in the diagnostic pathway of patients at increased risk of PCa

    Magnetic dating of the Holocene monogenetic Tkarsheti volcano in the Kazbeki region (Great Caucasus)

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    The radiocarbon technique is widely used to date Late Pleistocene and Holocene lava flows. The significant difference with palaeomagnetic methods is that the 14C dating is performed on the organic matter carbonized by the rock formation or the paleosols found within or below the lava flow. On the contrary, the archaeomagnetic dating allows to date the moment when the lava is cooling down below the Curie temperatures. In the present study, we use the paleomagnetic dating to constrain the age of the Tkarsheti monogenetic volcano located within the Kazbeki Volcanic Province (Great Caucasus). A series of rock-magnetic experiments including the measurement of hysteresis curves, isothermal remanence, back-field and continuous thermomagnetic curves were applied. These experiments indicated that Pseudo-Single-Domain Ti-poor titanomagnetite is responsible for remanence. A characteristic remanent magnetization was obtained for all twenty analyzed samples yielding a stable single magnetization component observed upon both thermal and alternating field treatments. Comparison of the mean directions obtained (Inc = 48.6º, Dec = 6.4º, A95 = 4.0° and K = 67) with the SCHA.DIF.14k model yielded two main time intervals (4740–4650 or 4427– 4188 BC) as the best age estimate of the Lesser Tkarsheti lava flow. These results suggest an earlier age (between approximately 200 and 700 years) for this monogenetic lava flow than expected from the estimated age provided by a former 14C dating obtained in 1973 on woody remains. This first attempt to use the archaeomagnetic technique in the Caucasus indicates that the SCHA.DIF.14k geomagnetic model may be successfully used for dating purposes in the region.Projects BU0066U16 and BU235P18 (Junta de Castilla y Leon, Spain) and the European Regional Development Fund (ERDF). AG is grateful for financial support of CONACyT 252149 and UNAM-PAPIIT project 101717. MC-R and AC acknowledge the financial support given by the Junta de Castilla y León (project BU235P18) and the European Regional Development Fund (ERD)

    Radical penectomy, a compromise for life: Results from the PECAD study

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    Background: The use of organ sparing strategies to treat penile cancer (PC) is currently supported by evidence that has indicated the safety, efficacy and benefit of this surgery. However, radical penectomy still represents up to 15-20% of primary tumor treatments in PC patients. The aim of the study was to evaluate efficacy in terms of overall survival (OS) and disease-free survival (DFS) of radical penectomy in PC patients.Methods: Data from a retrospective multicenter study (PEnile Cancer ADherence study, PECAD Study) on PC patients treated at 13 European and American urological centers (Hospital "Sant'Andrea", Sapienza University, Roma, Italy; "G.D'Annunzio" University, Chieti and ASL 2 Abruzzo, Hospital "S. Pio da Pietrelcina", Vasto, Italy; Department of Genitourinary Oncology, Moffitt Cancer Center, Tampa, FL, USA; Hospital of Budapest, Hungary; Department of Emergency and Organ Transplantation, Urology and Andrology Unit II, University of Bari, Italy; Hospital "Spedali Civil", Brescia, Italy; Istituto Europeo di Oncologia, University of Milan, Milan, Italy; University of Modena & Reggio Emilia, Modena, Italy; Hospital Universitario La Paz, Madrid, Spain; Ceara Cancer Institute, Fortaleza, Brazil; Virginia Commonwealth University, Richmond, VA, USA; Aristotle University of Thessaloniki, Thessaloniki, Greece; Maria Sklodowska-Curie Memorial Cancer Center, Warsaw, Poland) between 2010 and 2016 were used. Medical records of patients who specifically underwent radical penectomy were reviewed to identify main clinical and pathological variables. Kaplan-Meier method was used to estimate 1- and 5-year OS and DFS.Results: Of the entire cohort of 425 patients, 72 patients (16.9%) treated with radical penectomy were extracted and were considered for the analysis. The median age was 64.5 (IQR, 57.5-73.2) years. Of all, 41 (56.9%) patients had pT3/pT4 and 31 (43.1%) pT1/pT2. Moreover, 36 (50.0%) were classified as pN1-3 and 5 (6.9%) MI. Furthermore, 61 (84.7%) had a high grade (G2-G3) with 6 (8.3%) positive surgical margins. The 1- and 5-year OS rates were respectively 73.3% and 59.9%, while the 1- and 5-year DFS rates were respectively 67.3% and 35.1%.Conclusions: PC is an aggressive cancer particularly in more advanced stage. Overall, more than a third of patients do not survive at 5 years and more than 60% report a disease recurrence, despite the use of a radical treatment

    Radical penectomy, a compromise for life. Results from the PECAD study

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    Background: The use of organ sparing strategies to treat penile cancer (PC) is currently supported by evidence that has indicated the safety, efficacy and benefit of this surgery. However, radical penectomy still represents up to 15-20% of primary tumor treatments in PC patients. The aim of the study was to evaluate efficacy in terms of overall survival (OS) and disease-free survival (DFS) of radical penectomy in PC patients. Methods: Data from a retrospective multicenter study (PEnile Cancer ADherence study, PECAD Study) on PC patients treated at 13 European and American urological centers (Hospital “Sant'Andrea”, Sapienza University, Roma, Italy; “G.D'Annunzio” University, Chieti and ASL 2 Abruzzo, Hospital “S. Pio da Pietrelcina”, Vasto, Italy; Department of Genitourinary Oncology, Moffitt Cancer Center, Tampa, FL, USA; Hospital of Budapest, Hungary; Department of Emergency and Organ Transplantation, Urology and Andrology Unit II, University of Bari, Italy; Hospital “Spedali Civili”, Brescia, Italy; Istituto Europeo di Oncologia, University of Milan, Milan, Italy; University of Modena & Reggio Emilia, Modena, Italy; Hospital Universitario La Paz, Madrid, Spain; Ceara Cancer Institute, Fortaleza, Brazil; Virginia Commonwealth University, Richmond, VA, USA; Aristotle University of Thessaloniki, Thessaloniki, Greece; Maria Skłodowska-Curie Memorial Cancer Center, Warsaw, Poland) between 2010 and 2016 were used. Medical records of patients who specifically underwent radical penectomy were reviewed to identify main clinical and pathological variables. Kaplan-Meier method was used to estimate 1- and 5-year OS and DFS. Results: Of the entire cohort of 425 patients, 72 patients (16.9%) treated with radical penectomy were extracted and were considered for the analysis. The median age was 64.5 (IQR, 57.5-73.2) years. Of all, 41 (56.9%) patients had pT3/pT4 and 31 (43.1%) pT1/pT2. Moreover, 36 (50.0%) were classified as pN1-3 and 5 (6.9%) M1. Furthermore, 61 (84.7%) had a high grade (G2-G3) with 6 (8.3%) positive surgical margins. The 1- and 5-year OS rates were respectively 73.3% and 59.9%, while the 1- and 5-year DFS rates were respectively 67.3% and 35.1%. Conclusions: PC is an aggressive cancer particularly in more advanced stage. Overall, more than a third of patients do not survive at 5 years and more than 60% report a disease recurrence, despite the use of a radical treatment

    Scaling ozone responses of forest trees to the ecosystem level in a changing climate

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    Many uncertainties remain regarding how climate change will alter the structure and function of forest ecosystems. At the Aspen FACE experiment in northern Wisconsin, we are attempting to understand how an aspen/birch/maple forest ecosystem responds to long-term exposure to elevated carbon dioxide (CO 2 ) and ozone (O 3 ), alone and in combination, from establishment onward. We examine how O 3 affects the flow of carbon through the ecosystem from the leaf level through to the roots and into the soil micro-organisms in present and future atmospheric CO 2 conditions. We provide evidence of adverse effects of O 3 , with or without co-occurring elevated CO 2 , that cascade through the entire ecosystem impacting complex trophic interactions and food webs on all three species in the study: trembling aspen ( Populus tremuloides Michx . ), paper birch ( Betula papyrifera Marsh), and sugar maple ( Acer saccharum Marsh). Interestingly, the negative effect of O 3 on the growth of sugar maple did not become evident until 3 years into the study. The negative effect of O 3 effect was most noticeable on paper birch trees growing under elevated CO 2 . Our results demonstrate the importance of long-term studies to detect subtle effects of atmospheric change and of the need for studies of interacting stresses whose responses could not be predicted by studies of single factors. In biologically complex forest ecosystems, effects at one scale can be very different from those at another scale. For scaling purposes, then, linking process with canopy level models is essential if O 3 impacts are to be accurately predicted. Finally, we describe how outputs from our long-term multispecies Aspen FACE experiment are being used to develop simple, coupled models to estimate productivity gain/loss from changing O 3 .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72464/1/j.1365-3040.2005.01362.x.pd
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