Stochastic modeling and prediction of catalytic converters degradation
This paper proposes a stochastic model for describing the degradation process of catalytic converters over time, where the degradation is indirectly measured through the emission of complex hydrocarbons (HC) in legislated driving cycles. The proposed model is the superposition of two processes, the former being a dependent increments process which describes the actual degradation process, and the latter a white noise process which models the experimental errors. In particular, the proposed model assumes that the degradation growth in a small usage interval depends on the degradation level at the beginning of the interval, rather than on the age of the converter. The model has been applied t…
Hysteroscopy and treatment of uterine polyps.
This article summarizes and analyzes the salient topics on the diagnosis and management of endometrial polyps, focusing on the role of the hysteroscopy. Noninvasive investigations such as transvaginal ultrasonography, with or without the use of three-dimensional ultrasonography (3D US) and contrast techniques, remain the mainstay of first-line investigation. Hysteroscopic resection represents the gold standard minimally invasive treatment for endometrial polyps. It is the most effective management and allows histologic assessment, whereas blind biopsy or curettage have low diagnostic accuracy and should not be performed.
Risk factors associated with adverse fetal outcomes in pregnancies affected by Coronavirus disease 2019 (COVID-19): a secondary analysis of the WAPM study on COVID-19.
Abstract Objectives To evaluate the strength of association between maternal and pregnancy characteristics and the risk of adverse perinatal outcomes in pregnancies with laboratory confirmed COVID-19. Methods Secondary analysis of a multinational, cohort study on all consecutive pregnant women with laboratory-confirmed COVID-19 from February 1, 2020 to April 30, 2020 from 73 centers from 22 different countries. A confirmed case of COVID-19 was defined as a positive result on real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay of nasal and pharyngeal swab specimens. The primary outcome was a composite adverse fetal outcome, defined as the presence of either abortion (pre…
Office hysteroscopic treatment of a vanishing external uterine orifice in a postmenopausal woman with an obstetrical history of 44 abortions
Abstract Cervical stenosis, defined as cervical scarring of variable degree, represents a significant anatomical impediment to hysteroscopic procedures. Acquired cervical stenoses are more common than congenital forms and they are mainly associated with aging, estrogen–progesteron drugs, cervical trauma or carcinoma. The overcoming of cervical stenosis at office hysteroscopy is challenging and it often fails requiring the scheduling of the patient for an in-patient treatment under general anesthesia. We report the office hysteroscopy treatment of a vanishing external uterine orifice in a postmenopausal woman with an ultrasonographic report of a heterogeneous and thick endometrium suggestive…