875 research outputs found
First Passage Time of Filtered Poisson Process with Exponential Shape Function
Solving some integro-differential equation we find the Laplace transformation of the first passage time for Filtered Poisson Process generated by pulses with uniform or exponential distributions. Also, the martingale technique is applied for approximations of expectations accuracy is veryfying with the help of Monte-Carlo simulations.first passage times; laplace transformation; martingales; integro-differential equations; filtered poisson process; ornstein-uhlenbeck process
A data-driven probabilistic model for well integrity management: case study and model calibration for the Danish sector of North Sea
The correct functioning of well completion in oil and gas facilities is eminently important to assure continuity of production operations together with an adequate safety level. To enhance the performance of production wells and reduce maintenance expenditures, a paradigm shift from corrective maintenance to proactive risk based maintenance is necessary. The feasibility of fully probabilistic risk-based inspection planning approach for oil wells has been investigated as pilot study carried out at Danish Hydrocarbon Research and Technology Centre (DHRTC). After establishing a baseline for the system taxonomy, failure modes and their dependencies on deterioration mechanisms, a data collection and analysis lead to the calibration of a corrosion probabilistic model, based on pit size measured from tubing inspections. This manuscript presents the results of the feasibility study, the calibration of a bespoke corrosion model for wells in the Danish sector of North Sea, the reliability analysis and the identification of a threshold value for the pit penetration to be compared with current oil & gas (O&G) regulations. The model is further used to compare expected maintenance costs for corrective maintenance and condition-based maintenance. Results show how the condition-based maintenance policy results in lower maintenance costs and potential extension of well lifetime
Antifungal activity of antimicrobial peptides and proteins against Aspergillus fumigatus
This is the final published version, also available from MDPI via the DOI in this record.Antimicrobial peptides and proteins (AMPs) provide an important line of defence against invading microorganisms. However, the activity of AMPs against the human fungal pathogen Aspergillus fumigatus remains poorly understood. Therefore, the aim of this study was to characterise the anti-Aspergillus activity of specific human AMPs, and to determine whether A. fumigatus can possess resistance to specific AMPs, as a result of in-host adaptation. AMPs were tested against a wide range of clinical isolates of various origins (including cystic fibrosis patients, as well as patients with chronic and acute aspergillosis). We also tested a series of isogenic A. fumigatus isolates obtained from a single patient over a period of 2 years. A range of environmental isolates, obtained from soil in Scotland, was also included. Firstly, the activity of specific peptides was assessed against hyphae using a measure of fungal metabolic activity. Secondly, the activity of specific peptides was assessed against germinating conidia, using imaging flow cytometry as a measure of hyphal growth. We showed that lysozyme and histones inhibited hyphal metabolic activity in all the A. fumigatus isolates tested in a dose-dependent fashion. In addition, imaging flow cytometry revealed that histones, β-defensin-1 and lactoferrin inhibited the germination of A. fumigatus conidia.Wellcome TrustMedical Research Council (MRC
El Mañana: Año II Número 9 - (09/01/29)
There is no consensus on the treatment of multifocal primary cutaneous anaplastic large cell lymphoma (C-ALCL). Radiotherapy (RT) and methotrexate (MTX) are the current treatment options, but their efficacy is unknown. Recently, targeted therapies showed promising results in C-ALCL, and may therefore be an attractive first choice of treatment. To assess the efficacy of conventional treatment strategies for patients with multifocal C-ALCL, and to define which patients may require novel targeted therapies. In this multicenter study, treatment was evaluated in patients initially presenting (n=24) or relapsing with multifocal C-ALCL (n=17; 23 relapses). Distinction was made between cases with ≤ 5 (n=36) and >5 lesions (n=11). Treatments most commonly used were radiotherapy (n=21), systemic chemotherapy (n=9) and low-dose methotrexate (MTX; n=7) with complete response rates of 100%, 78% and 43%, respectively, and an overall response rate of 100%, 100%, and 57%, respectively. Four patients showed a complete spontaneous regression. Sixteen of 24 patients (67%) first presenting with multifocal C-ALCL relapsed, including all five patients initially treated with CHOP. Compared with patients presenting with 2-5 skin lesions, patients presenting with >5 lesions had a higher chance of developing extracutaneous relapse (56 vs 20%) and more often died of lymphoma (44% vs 7%). Patients with ≤5 lesions should be treated with low-dose RT (2x4 Gy). Maintenance low-dose MTX (20 mg/week) is a suitable option in patients with >5 lesions. Targeted therapies may be considered in rare patients refractory to MTX or patients developing extracutaneous disease. This article is protected by copyright. All rights reserve
Frequency and prognosis of associated malignancies in 504 patients with lymphomatoid papulosis
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218179.pdf (Publisher’s version ) (Open Access)BACKGROUND: Lymphomatoid papulosis (LyP) can be associated with other haematological malignancies (HM), but reported percentages vary from 20% to over 50%. OBJECTIVE: To evaluate the frequency and prognostic significance of associated HM and non-HM in LyP patients. METHODS: In this multicentre cohort study, the complete Dutch LyP population was included from the Dutch Cutaneous Lymphoma Registry between 1985 and 2018. Clinical and histopathological information was retrieved from every individual patient. RESULTS: After a median follow-up of 120 months (range, 6-585), an associated HM was observed in 78/504 (15.5%) patients. Most common associated HM were mycosis fungoides (MF; n = 31) and anaplastic large-cell lymphoma (ALCL; n = 29), while 19 patients had another HM of B-cell (n = 14) or myeloid origin (n = 5). Even after a 25-year follow-up period, percentages of associated HM did not exceed 20%. Thirty-nine of 465 patients (8.4%) without a prior or concurrent associated HM developed an associated HM during follow-up, after a median of 68 months (range of 3-286 months). Nine of 78 patients died of associated HM, including 6/22 patients developing extracutaneous ALCL, while all patients with associated MF or skin-limited ALCL had an excellent prognosis. Compared with the general population, LyP patients showed an increased risk (relative risk, 2.8; 95% confidence intervals, 2.4-3.3) for non-HM, in particular cutaneous squamous cell carcinoma, melanoma and intestinal/lung/bladder cancer. CONCLUSIONS: An associated HM was reported in 15.5% of the LyP patients, particularly MF and ALCL. Although the frequency of associated HM is lower than suggested and the prognosis of most patients with associated HM is excellent, a small subgroup will develop aggressive disease, in particular extracutaneous ALCL. Furthermore, LyP patients have a higher risk of developing other malignancies. Clinicians should be aware of these risks, and LyP patients require close monitoring
Component-Mode-Based Monte Carlo Simulation for Efficient Probabilistic Vibration Analysis
Human papillomavirus infection in honduran women with normal cytology
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80440.pdf (publisher's version ) (Closed access)OBJECTIVE: This study was aimed at estimating type-specific HPV prevalence and its cofactors among Honduran women with normal cytology in order to provide valuable information to health policymakers about the epidemiology of this important sexually transmitted infection. METHODS: A total of 591 women with normal cytology from Tegucigalpa, Honduras were interviewed and tested for HPV using the SPF10 LiPA25. A structured epidemiological questionnaire was administered to each woman. RESULTS: The overall HPV prevalence was 51%. Twenty-three types of HPV were detected; HPV 16, 51, 31, 18, and 11 were the most common. The highest prevalence of cancer associated HPV types (15.0%) was found in the women less than 35 years. Besides the association with age, the main independent predictors of HPV infection were the lifetime number of sexual partners and having a low socioeconomic status and less than 5 previous Pap smears. CONCLUSIONS: In the population studied, there was a broad diversity of HPV infections, with high-risk types being the most common types detected. The establishment of a well-characterized population with regard to the community prevalence of type-specific HPV infection will provide a valuable baseline for monitoring population effectiveness of an HPV vaccine
Patients with usual vulvar intraepithelial neoplasia-related vulvar cancer have an increased risk of cervical abnormalities
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81890.pdf (publisher's version ) (Closed access)BACKGROUND: Vulvar squamous cell carcinoma (SCC) originates the following two pathways, related to differentiated (d) vulvar intraepithelial neoplasia (VIN) or to human papillomavirus (HPV)-related usual (u) VIN. Multicentric HPV infections (cervix, vagina and vulva) are common. We hypothesise that patients with a uVIN-related vulvar SCC more often have cervical high-grade squamous intraepithelial lesions (HSILs) compared with women with dVIN-related vulvar SCC. METHODS: All vulvar SCCs (201) were classified to be dVIN- (n=164) or uVIN related (n=37). Data with regard to the smear history and cervical histology were retrieved from PALGA, the nationwide Netherlands database of histo- and cytopathology. For HSIL cervical smears of which histology was taken, HPV DNA analysis on both the vulvar and cervical specimens was performed. RESULTS: At least one smear was available in 145 (72%) of the 201 patients. Patients with a uVIN-related vulvar SCC more often had an HSIL compared with patients with a dVIN-related SCC (35 vs 2%, P<0.001). A total of 10 of the 13 HSILs were histologically assessed and identical HPV types were found in the vulva and cervix. CONCLUSION: These data emphasise the necessity to differentiate between dVIN- and uVIN-related vulvar tumours and to examine the entire lower female ano-genital tract once an uVIN-related lesion is found
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