281 research outputs found

    Sars-cov-2 detection in fecal sample from a patient with typical findings of covid-19 pneumonia on ct but negative to multiple sars-cov-2 rt-pcr tests on oropharyngeal and nasopharyngeal swab samples

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    Reverse transcriptase polymerase chain reaction (RT-PCR) negative results in the upper respiratory tract represent a major concern for the clinical management of coronavirus disease 2019 (COVID-19) patients. Herein, we report the case of a 43-years-old man with a strong clinical suspicion of COVID-19, who resulted in being negative to multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RT-PCR tests performed on different oropharyngeal and nasopharyngeal swabs, despite serology having confirmed the presence of SARS-CoV-2 IgM. The patient underwent a chest computed tomography (CT) that showed typical imaging findings of COVID-19 pneumonia. The presence of viral SARS-CoV-2 was confirmed only by performing a SARS-CoV-2 RT-PCR test on stool. Performing of SARS-CoV-2 RT-PCR test on fecal samples can be a rapid and useful approach to confirm COVID-19 diagnosis in cases where there is an apparent discrepancy between COVID-19 clinical symptoms coupled with chest CT and SARS-CoV-2 RT-PCR tests’ results on samples from the upper respiratory tract

    The use of near-infrared reflectance spectroscopy (NIRS) in the prediction of chemical composition and in vitro neutral detergent fiber (NDF) digestibility of Italian alfalfa hay.

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    The objective of the present work was to develop calibration equations for the prediction of chemical composition and forage digestibility from different populations of alfalfa hay harvested in Parmigiano- Reggiano cheese production area of Northern Italy. Due to annual climatic variations that affect soil and growing conditions and consequently cause high variability in chemical and physical composition, 319 hay samples from four years were used to build robust calibration. NIRS calibration equations were developed for the prediction of in vitro NDF digestibility (IVNDFd) and 20 chemical parameters (dry matter, starch, fat, sugar, fiber fractions, crude protein, nitrogen fractions and some minerals) of Italian hay. The results obtained show that NIRS equations greatly explain the variation in the composition existing in alfalfa hays grown in Northern Italy, except for a few parameters characterized by low variability range value. The equations obtained for the prediction of biological and chemical parameters explain the major part of the variation existing in the reference data, which open great prospects for the use of NIRS in planning feeding strategies of livestock, based on alfalfa forage

    Image-guided multisession radiosurgery of skull base meningiomas

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    Background: The efficacy of single-session stereotactic radiosurgery (sSRS) for the treatment of intracranial meningioma is widely recognized. However, sSRS is not always feasible in cases of large tumors and those lying close to critically radiation-sensitive structures. When surgery is not recommended, multi-session stereotactic radiosurgery (mSRS) can be applied. Even so, the efficacy and best treatment schedule of mSRS are not yet established. The aim of this study is to validate the role of mSRS in the treatment of skull base meningiomas. Methods: A retrospective analysis of patients with skull base meningiomas treated with mSRS (two to five fractions) at the University of Messina, Italy, from 2008 to 2018, was conducted. Results: 156 patients met the inclusion criteria. The median follow-up period was 36.2 \ub1 29.3 months. Progression-free survival at 2-, 5-, and 10-years was 95%, 90%, and 80.8%, respectively. There were no new visual or motor deficits, nor cranial nerves impairments, excluding trigeminal neuralgia, which was reported by 5.7% of patients. One patient reported carotid occlusion and one developed brain edema. Conclusion: Multisession radiosurgery is an effective approach for skull base meningiomas. The long-term control is comparable to that obtained with conventionally-fractionated radiotherapy, while the toxicity rate is very limited

    n-XYTER: A CMOS read-out ASIC for a new generation of high rate multichannel counting mode neutron detectors

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    For a new generation of 2-D neutron detectors developed in the framework of the EU NMI3 project DETNI [1], the 128-channel frontend chip n-XYTER has been designed. To facilitate the reconstruction of single neutron incidence points, the chip has to provide a spatial coordinate (represented by the channel number), as well as time stamp and amplitude information to match the data of x- and y-coordinates. While the random nature of the input signals calls for self-triggered operation of the chip, on-chip derandomisation and sparsi cation is required to exploit the enormous rate capability of these detectors ( 4 106cm2s1). The chosen architecture implements a preampli er driving two shapers with di erent time constants per channel. The faster shaper drives a single-pulse discriminator with subsequent time-walk compensation. The output of this circuit is used to latch a 14-bit time stamp with a 2 ns resolution and to enable a peak detector circuit fed by the slower shaper branch. The analogue output of the peak detector as well as the time stamp are stored in a 4-stage FIFO for derandomisation. The readout of these FIFOs is accomplished by a token-ring based multiplexer working at 32 MHz, which accounts for further derandomisation, sparsi cation and dynamic bandwidth distribution. The chip was submitted for manufacturing in AMS's C35B4M3 0.35µm CMOS technology in June 2006
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