39 research outputs found

    Monitoring of the declining trend of Polychlorobifenyls concentration in milk of contaminated dairy cows

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    Six pregnant heifers, coming from a herd with a history of high concentration of polychlorobifenyls (PCB) into the milk, were fed with a very low-PCB diet starting from the 6th month of pregnancy. After parturition cows were milked for at least 190 d with a maximum of 270 d. Diet was made of: corn silage (31.7% of DMI), dehydrated alfalfa (13.3% of DMI), grass hay (3.7% of DMI) and concentrate (51.3% of DMI). The average DMI was 23.12 kg/d. Milk production was recorded and samples of milk and blood were taken and analyzed for PCB (18, 28, 31, 52, 44, 101, 149, 118, 153, 138, 180 and 194 congeners) content using a GC-MS technique. The average milk yield (kg/d) of the 6 cows was 26.0, 22.5, 23.2, 24.5, 28.9, 29.3. The maximum PCB concentration of 100 ng/g of fat allowed by the Italian law was reached after 144-209 d of lactation. One animal after 204 days had a PCB concentration of 102 ng/g fat. If log10 of PCB concentration (ppb) in milk fat is regressed against days in milking (DIM) the following significant equation was obtained: log10 PCB (ng/g of milk fat)= 2.796 -0.00474 DIM; r2 0.72; P<0.01 The initial level of contamination is not the main factor affecting the time required in order for PCB to return to below the legal threshold of 100 ng/g fat, while daily milk yield significantly affects PCB excretion. Body condition and energy balance could be important factors affecting PCB excretion. In the presence of high contamination, about 6 months of lactation are required in order to obtain milk with a sufficiently low PCB content. Among the seven congeners considered by Italian legislation, PCB 101, PCB 118, PCB 138, PCB 153 constitute almost all the PCBs found in tissues and milk, with a much smaller presence of PCB 180, and the numbers of the congeners PCB 28 and PCB 52 are almost insignificant, probably because they accumulate little in the body. The congeners PCB 138 and PCB 153 are those most frequently found. For PCB 138 the liver is the principal organ of accumulation, while for PCB 153 we found equal accumulations in the liver, kidneys and tail, but a low presence in milk. The PCBs 118 and 138 are those most abundant in milks

    Takayasu arteritis: a cohort of Italian patients and recent pathogenetic and therapeutic advances

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    Takayasu arteritis (TAK) is a rare granulomatous vasculitis of unknown etiology that mainly affects the aorta and its major branches. The aim is to describe the clinical features, diagnostic procedures, pathogenesis, and management of TAK in a longitudinal cohort of patients recruited within a single region of southern Italy. The cohort included 43 patients who were diagnosed with TAK and followed up according to a standard protocol, in a collaboration between four university tertiary referral centers and a regional hospital. Clinical and imaging classification criteria were those established by the American College of Rheumatology. Thirty-five patients (81.4%) were female, and the mean age at disease onset was 32.6 (range 16-54) years. Angiographic assessment of the vascular involvement allowed disease classification in five different types. Clinical features ranged from constitutional symptoms in the early inflammatory stage of the disease to cardiovascular ischemic symptoms in the late, chronic stage. Noninvasive imaging techniques were employed to assess the extent and severity of the arterial wall damage and to monitor the clinical course and response to therapy. Medical treatment, based on pathogenetic insights into the roles of humoral and cell-mediated immune mechanisms, included glucocorticoids mostly combined with steroid-sparing immunosuppressive agents and, in patients with relapsing/refractory disease, biologic drugs. Significant clinical and angiographic differences have been detected in TAK patients from different geographic areas. Patients with life-threatening cardiovascular and neurologic manifestations as well as sight-threatening ophthalmologic signs and symptoms should be promptly diagnosed, properly treated, and closely followed up to avoid potentially severe consequences

    Evaluation and validation of an alternative method to detect Campylobacter spp. in dairy products

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    Foods implicated in human campylobacteriosis include raw or undercooked poultry and raw dairy products. Because Campylobacter spp. are the most frequently reported cause of bacterial infection in the European Union and because conventional methods are cumbersome, rapid methods for Campylobacter detection and quantification in food are needed. With this study we sought to validate, according to the standard procedure (UNI EN ISO 16140:2003), an alternative to the reference analytical method (UNI EN ISO 10272- 1:2006) for official controls of Campylobacter spp. in raw milk and dairy products. Milk samples collected from 16 milk vending machines located throughout the Genoa metropolitan area were analyzed using two different methods, an enzymelinked fluorescent assay (ELFA) and a real-time PCR assay, and evaluated in parallel against the reference method. In addition, a total of 460 samples of raw milk collected from milk vending machines were analyzed by ELFA. Results obtained with ELFA showed it was compliant with UNI EN ISO 10272-1:2006 criteria and that the immunoassay had 100% sensitivity, specificity, and accuracy. Regarding samples of milk vending machines, 5.0% (23/460) tested positive at ELFA screening and were subsequently confirmed as C. jejuni. Validation according to UNI EN ISO 16140:2003 of the ELFA method suggests it may be a useful alternative to conventional methods for detecting Campylobacter spp. in official controls

    PĂ©rigord black truffle genome uncovers evolutionary origins and mechanisms of symbiosis

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    LetterInternational audienceThe PĂ©rigord black truffle (Tuber melanosporumTuber\ melanosporum Vittad.) and the Piedmont white truffle dominate today's truffle market. The hypogeous fruiting body of T. melanosporumT.\ melanosporum is a gastronomic delicacy produced by an ectomycorrhizal symbiont endemic to calcareous soils in southern Europe. The worldwide demand for this truffle has fuelled intense efforts at cultivation. Identification of processes that condition and trigger fruit body and symbiosis formation, ultimately leading to efficient crop production, will be facilitated by a thorough analysis of truffle genomic traits. In the ectomycorrhizal Laccaria bicolorLaccaria\ bicolor, the expansion of gene families may have acted as a 'symbiosis toolbox'. This feature may however reflect evolution of this particular taxon and not a general trait shared by all ectomycorrhizal species. To get a better understanding of the biology and evolution of the ectomycorrhizal symbiosis, we report here the sequence of the haploid genome of T. melanosporumT.\ melanosporum, which at ∌\sim125 megabases is the largest and most complex fungal genome sequenced so far. This expansion results from a proliferation of transposable elements accounting for ∌\sim58% of the genome. In contrast, this genome only contains ∌\sim7,500 protein-coding genes with very rare multigene families. It lacks large sets of carbohydrate cleaving enzymes, but a few of them involved in degradation of plant cell walls are induced in symbiotic tissues. The latter feature and the upregulation of genes encoding for lipases and multicopper oxidases suggest that T. melanosporumT.\ melanosporum degrades its host cell walls during colonization. Symbiosis induces an increased expression of carbohydrate and amino acid transporters in both L. bicolorL.\ bicolor and T. melanosporumT.\ melanosporum, but the comparison of genomic traits in the two ectomycorrhizal fungi showed that genetic predispositions for symbiosis −-'the symbiosis toolbox'−- evolved along different ways in ascomycetes and basidiomycete

    The Imaging X-ray Polarimetry Explorer (IXPE): Technical Overview

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    The Imaging X-ray Polarimetry Explorer (IXPE) will expand the information space for study of cosmic sources, by adding linear polarization to the properties (time, energy, and position) observed in x-ray astronomy. Selected in 2017 January as a NASA Astrophysics Small Explorer (SMEX) mission, IXPE will be launched into an equatorial orbit in 2021. The IXPE mission will provide scientifically meaningful measurements of the x-ray polarization of a few dozen sources in the 2-8 keV band, including polarization maps of several x-ray-bright extended sources and phase-resolved polarimetry of many bright pulsating x-ray sources

    An X-ray burst from a magnetar enlightening the mechanism of fast radio bursts

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    Fast radio bursts (FRBs) are millisecond radio pulses originating from powerful enigmatic sources at extragalactic distances. Neutron stars with large magnetic fields (magnetars) have been considered as the sources powering the FRBs, but the connection requires further substantiation. Here we report the detection by the AGILE satellite on 28 April 2020 of an X-ray burst in temporal coincidence with a bright FRB-like radio burst from the Galactic magnetar SGR 1935+2154. The burst observed in the hard X-ray band (18-60 keV) lasted about 0.5 s, it is spectrally cut off above 80 keV and implies an isotropically emitted energy of about 1040 erg. This event demonstrates that a magnetar can produce X-ray bursts in coincidence with FRB-like radio bursts. It also suggests that FRBs associated with magnetars can emit X-ray bursts. We discuss SGR 1935+2154 in the context of FRBs with low-intermediate radio energies in the range 1038-1040 erg. Magnetars with magnetic fields B ≈ 1015 G may power these FRBs, and new data on the search for X-ray emission from FRBs are presented. We constrain the bursting X-ray energy of the nearby FRB 180916 to be less than 1046 erg, smaller than that observed in giant flares from Galactic magnetars

    AGILE detection of extreme Îł -ray activity from the blazar PKS 1510-089 during March 2009: Multifrequency analysis

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    We report on the extreme gamma-ray activity from the FSRQ PKS 1510-089 observed by AGILE in March 2009. In the same period a radio-to-optical monitoring of the source was provided by the GASP-WEBT and REM. Moreover, several Swift ToO observations were triggered, adding important information on the source behaviour from optical/UV to hard X-rays. We paid particular attention to the calibration of the Swift/UVOT data to make it suitable to the blazars spectra. Simultaneous observations from radio to gamma rays allowed us to study in detail the correlation among the emission variability at different frequencies and to investigate the mechanisms at work. In the period 9-30 March 2009, AGILE detected an average gamma-ray flux of (311+/-21)x10^-8 ph cm^-2 s^-1 for E>100 MeV, and a peak level of (702+/-131)x10^-8 ph cm^-2 s^-1 on daily integration. The gamma-ray activity occurred during a period of increasing activity from near-IR to UV, with a flaring episode detected on 26-27 March 2009, suggesting that a single mechanism is responsible for the flux enhancement observed from near-IR to UV. By contrast, Swift/XRT observations seem to show no clear correlation of the X-ray fluxes with the optical and gamma-ray ones. However, the X-ray observations show a harder photon index (1.3-1.6) with respect to most FSRQs and a hint of harder-when-brighter behaviour, indicating the possible presence of a second emission component at soft X-ray energies. Moreover, the broad band spectrum from radio-to-UV confirmed the evidence of thermal features in the optical/UV spectrum of PKS 1510-089 also during high gamma-ray state. On the other hand, during 25-26 March 2009 a flat spectrum in the optical/UV energy band was observed, suggesting an important contribution of the synchrotron emission in this part of the spectrum during the brightest gamma-ray flare, therefore a significant shift of the synchrotron peak

    18F-FDG PET/CT: a review of diagnostic and prognostic features in multiple myeloma and related disorders

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    Conventional radiographic skeletal survey has been for many years the gold standard to detect the occurrence of osteolytic lesions in patients with multiple myeloma (MM). However, the introduction of more sensitive imaging procedures has resulted in an updated anatomic and functional Durie and Salmon “plus” staging system and has remarkably changed the diagnostic and prognostic approach to this tumor. It is now established that 18fluorine-fluorodeoxyglucose (18F-FDG) positron-emission tomography (PET) combined with low-dose computed tomography (CT), shortly designated PET/CT, exhibits a higher screening and diagnostic sensitivity and specificity over the skeleton X-ray. In patients with monoclonal gammopathy of undetermined significance and in those with smoldering MM, PET/CT is consistently unable to detect focal and/or diffuse marrow abnormalities. Conversely, based on a systematic review of 18 studies comprising almost 800 MM patients, PET/CT was able to detect MM osteolytic lesions with a sensitivity of approximately 80–90&nbsp;% and a specificity of 80–100&nbsp;%. Importantly, a poor degree of concordance has also been emphasized between PET/CT and whole-body magnetic resonance imaging (WB-MRI) in that when both techniques were applied to the same patients, double-positive results were recorded in approximately 30&nbsp;% of the cases, but in the majority of them, a higher number of lesions were revealed with PET/CT than with MRI. Double-negative results, on the other hand, were found in about 22&nbsp;% of the patients. Because PET/CT is able to identify tumor foci throughout the body, it can be usefully applied to the study of solitary bone plasmacytoma and extra-medullary plasmacytoma: In both conditions, the detection of additional, previously overlooked sites of skeletal involvement would falsify the diagnosis of single-district disease, upstage the tumor, and therefore require a different therapeutic approach. In addition, although PET/CT is poorly sensitive to diffuse bone marrow infiltration, it can anticipate a site of impending fracture throughout the body and can discriminate old from new pathologic fractures. MRI should, however, be preferred when vertebral bodies are suspected to be involved and the risk of vertebral fracture is to be assessed. PET/CT is a sensitive and reliable procedure to evaluate the response to chemotherapy and/or radiotherapy, which is shown by a remarkable reduction and sometimes total disappearance of FDG accumulation in the involved bony structures, although these structures remain morphologically abnormal. Conversely, an increased focal uptake of FDG in apparent remission patients often precedes clinically overt relapse. PET/CT should be preferred to other imaging techniques to assess the remission status after autologous stem cell transplantation. In patients with primary and remission-induced non-secretory MM, the use of PET/CT may help to early detect single or multiple districts of focal non-secretory relapse. Osteonecrosis of the jaw, its location, and extent in MM patients receiving bis-phosphonates are better defined by both PET/CT and contrast-enhanced MRI compared with dental panoramic views derived from cone beam CT imaging. Little is known as to the possible role of PET/CT in the assessment of disease extension, tumor load, and response to therapy in patients with Waldenström’s macroglobulinemia (WM). In a study conducted on 35 WM patients, comparative PET/CT before and after therapy was able to detect positive findings in 83&nbsp;% of the patients, in contrast with the previous results achieved with conventional imaging that reported visceral involvement in much lower percentages. Similarly scanty are the data on the use of PET/CT in localized and systemic amyloidosis, given the small number of patients studied so far. A retrospective study has shown that, at variance from 123Iodine-serum amyloid P component (123I-SAP) scintigraphy, which was found to be positive in about one-third of the patients with localized amyloidosis, an increased FDG uptake was detected at the amyloid site in virtually all of them. On the contrary, none of the patients with systemic amyloidosis showed an increased FDG uptake in sites of known deposition, whereas 123I-SAP scintigraphy tested positive in the large majority of them. In another study, however, no such remarkable difference of positive PET/CT scans between localized and systemic amyloidosis was reported. Finally, false-positive and false-negative PET/CT findings can occur in different conditions that should be kept in mind to avoid wrong or omitted diagnoses

    The olfactory system is affected by steroid aerosol treatment in mice.

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    Asthma needs continuous treatment often for years. In humans, some drugs are administered via aerosol, therefore they come in contact with both respiratory and olfactory mucosa. We explored the possibility that antiasthma corticosteroid treatment could influence the olfactory function by passage through the nose. A group of mice was exposed twice daily for 42 days to fluticasone propionate aerosol and was compared with a control group. Olfactory behavior, respiratory mechanics, histology, and immunoreactivity in the olfactory system were assessed. Fluticasone-treated mice were slower in retrieving a piece of hidden food, but both groups were similarly fast when the food was visible. When a clearly detectable odor was present in the environment, all mice behaved in a similar way. Respiratory mechanics indices were similar in all mice except for the viscose resistance, which was reduced in fluticasone-treated mice. Olfactory mucosa of fluticasone-treated mice was thicker than that of controls. Slight but consistent differences in staining were present for Olfactory Marker Protein but not for other proteins. A mild impairment of olfactory function is present in mice chronically treated with fluticasone aerosol, apparently accompanied by slight modifications of the olfactory receptor cells, and suggests monitoring of olfactory function modifications in long-term steroid users

    Plasmon-assisted bandgap engineering in dilute nitrides

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    The inherent ability of plasmonic bowtie nanoapertures (NAs) to localize the electromagnetic field at a subwavelength scale was exploited to engineer the H removal process in dilute nitrides at the nanometer level. Dilute nitride semiconductor alloys (e.g. GaAsN with a small percentage of nitrogen) are characterized by peculiar optoelectronic properties and, most importantly, by an even more peculiar response to hydrogen incorporation. In this class of materials, it is indeed possible to tune post-growth the alloy bandgap energy by a controlled incorporation of hydrogen atoms. The formation of N-H complexes neutralizes all the effects N has on the host matrix, among which is the strong narrowing of bandgap energy. In the present work, bowtie NAs resonant to the N-H complex dissociation energy were numerically modeled by finite element method simulations, realized by a lithographic approach, and characterized by scanning probe microscopy and resonant scattering spectroscopies. The conditions to get the maximum field enhancement at a specific position below the metal/semiconductor interface, namely at the dilute nitride quantum well position, were identified, demonstrating the ability to achieve a plasmon-assisted spatially selective hydrogen removal in a GaAsN/GaAs quantum well sample. Hydrogen removal through bowtie NAs turns out to be way more efficient (approximately two orders of magnitude) than through the plain surface, thus indicating that bandgap engineering through plasmonic nanostructures can be optimized for future efficient realization of site-controlled single-photon emitters and for their deterministic integration in plasmonic devices
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