2,558 research outputs found

    Invisible Events with Radiative Photons at LEP

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    A study of the radiative neutrino counting reaction e+eννˉγe^+ e^- \to \nu {\bar \nu} \gamma at LEP1 and LEP2 energies is presented. An approximate expression for the spectrum of the observed photon is derived within the framework of the ptp_t-dependent structure function approach. This is compared with an exact expression and found in agreement within the foreseen experimental accuracy. This model describing single-photon radiation can be applied to the more general case of initial-state single-photon emission accompanying invisible final-state events. Higher-order QED corrections due to undetected initial-state radiation are also included. The implementation in a Monte Carlo event generator is briefly described.Comment: 10 pages, LaTeX, 7 figures available via anonymous ftp at: ftp://cobra1.pv.infn.it/pub/phot/, files fig#n.ps with #=1,...,

    Analysis of short-term blood pressure variability in pheochromocytoma/paraganglioma patients

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    Data on short-term blood pressure variability (BPV), which is a well-established cardiovascular prognostic tool, in pheochromocytoma and paraganglioma (PPGL) patients is still lack and conflicting. We retrospectively evaluated 23 PPGL patients referred to our unit from 2010 to 2019 to analyze 24 h ambulatory blood pressure monitoring (24-h ABPM)-derived markers of short-term BPV, before and after surgical treatment. PPGL diagnosis was assessed according to guidelines and confirmed by histologic examination. The 24-h ABPM-derived markers of short-term BPV included: circadian pressure rhythm; standard deviation (SD) and weighted SD (wSD) of 24-h, daytime, and night-time systolic and diastolic blood pressure (BP); average real variability (ARV) of 24-h, daytime, and night-time systolic and diastolic BP. 7 males and 16 females of 53 ± 18 years old were evaluated. After surgical resection of PPGL we found a significant decrease in 24-h systolic BP ARV (8.8 ± 1.6 vs. 7.6 ± 1.3 mmHg, p < 0.001), in 24-h diastolic BP ARV (7.5 ± 1.6 vs. 6.9 ± 1.4 mmHg, p = 0.031), and in wSD of 24-h diastolic BP (9.7 ± 2.0 vs 8.8 ± 2.1 mmHg, p = 0.050) comparing to baseline measurements. Moreover, baseline 24-h urinary metanephrines significantly correlated with wSD of both 24-h systolic and diastolic BP. Our study highlights as PPGL patients, after proper treatment, show a significant decrease in some short-term BPV markers, which might represent a further cardiovascular risk factor

    Pyomyositis associated with abscess formation caused by streptococcus pneumoniae in children: a case report and review of literature

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    Background: Pyomyositis is an unusual bacterial infection but potential severe in children. Staphylococcus Aureus is the main caused of this disease (70–90%), following by Streptococcus Pyogenes (4–16%). Streptococcus Pneumoniae rarely caused invasive muscular infections. We describe a case of pyomyositis caused by Streptococcus Pneumonia in an adolescent 12-year-old female. Case presentation: I.L. referred to our hospital for high fever associated with right hip and abdominal pain. The blood exams showed increase of leukocytes with prevalence of neutrophils with high level of inflammatory markers (CRP 46,17 mg/dl; Procalcitonin 25,8 ng/ml). The abdomen ultrasonography was unremarkable. The CT and MRI of the abdomen and right hip revealed pyomyositis of the iliopsoas, piriformis and internal shutter associated with collection of pus between the muscular planes (Fig. 1). The patient was admitted to our paediatric care unit, and she was initially treatment with intravenous Ceftriaxone (100 mg/kg/day) and Vancomycin (60 mg/kg/day). On day 2, a pansensitive Streptococcus Pneumoniae was isolated from the blood culture, and the antibiotic treatment was changed to only IV Ceftriaxone. She was successively treated with IV Ceftriaxone for 3 weeks, then continued with oral Amoxicillin for a total of 6 weeks of therapy. The follow up showed a complete resolution of the pyomyositis and psoas abscess after 2 months. Conclusion: Pyomyositis associate with abscess is a rare and very dangerous disease in children. The clinical presentation can mimic symptoms of other pathologies like osteomyelitis or septic arthritis, so many times is hard to identify. The main risk factors include story of recent trauma and immunodeficiency, not present in our case report. The therapy involves the antibiotics and, if possible, abscess drainage. In literature there is much discussion about duration of antibiotic therapy

    Implications of a Low sin(2 beta): A Strategy for Exploring New Flavor Physics

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    We explore the would-be consequences of a low value of the CP-violating phase sin2βψK\sin2\beta_{\psi K}. The importance of a reference triangle obtained from measurements that are independent of BB--Bˉ\bar B and KK--Kˉ\bar K mixing is stressed. It can be used to extract separately potential New Physics contributions to mixing in the BdB_d, BsB_s and KK systems. We discuss several constructions of this triangle, which will be feasible in the near future. The discrete ambiguity is at most two-fold and eventually can be completely removed. Simultaneously, it will be possible to probe for New Physics in loop-dominated rare decays.Comment: 9 pages, 6 figure

    Antibiotic resistance, virulence factors, phenotyping, and genotyping of non\u2013escherichia coli enterobacterales from the gut microbiota of healthy subjects

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    Non-Escherichia coli Enterobacterales (NECE) can colonize the human gut and may present virulence determinants and phenotypes that represent severe heath concerns. Most information is available for virulent NECE strains, isolated from patients with an ongoing infection, while the commensal NECE population of healthy subjects is understudied. In this study, 32 NECE strains were isolated from the feces of 20 healthy adults. 16S rRNA gene sequencing and mass spectrometry attributed the isolates to Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Enterobacter aerogenes, Enterobacter kobei, Citrobacter freundii, Citrobacter amalonaticus, Cronobacter sp., and Hafnia alvei, Morganella morganii, and Serratia liquefaciens. Multiplex PCR revealed that K. pneumoniae harbored virulence genes for adhesins (mrkD, ycfM, and kpn) and enterobactin (entB) and, in one case, also for yersiniabactin (ybtS, irp1, irp2, and fyuA). Virulence genes were less numerous in the other NECE species. Biofilm formation was spread across all the species, while curli and cellulose were mainly produced by Citrobacter and Enterobacter. Among the most common antibiotics, amoxicillin-clavulanic acid was the sole against which resistance was observed, only Klebsiella strains being susceptible. The NECE inhabiting the intestine of healthy subjects have traits that may pose a health threat, taking into account the possibility of horizontal gene transfer

    Criminological and Medico-legal Aspects in Homicidal and Suicidal Sharp Force Fatalities

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    The interpretation of sharp force fatality dynamics may be difficult in some cases, but a contribution to analysis of the phenomenon may be provided by case studies. Therefore, the purpose of our study is focused on identifying, in observed sharp force fatalities, reliable parameters that can differentiate a homicidal and suicidal manner of death, with particular reference to criminological parameters. Data derived from sharp force fatality cases in Padua and Venice from 1997 to 2019, anonymized and collected in Excel, included personal, circumstantial, clinical, and psychopathological\u2013criminological data, as well as crime scene investigation, necroscopic, and toxicological data. Statistical analyses were performed using chi-square and Wilcoxon rank-sum tests. Possible predictors of homicide were analyzed by logistic regression. Six parameters (bloodstains distant from the body, clothing lacerations, hesitation/defense wounds, number of injuries, and potential motives) were significantly different in the two groups (p\ua0<\ua00.05). An independent statistical association between potential motives explaining the crime (p\ua0<\ua00.001; OR 27.533) and homicide on multiple logistic regression analysis was highlighted. The absence of clothing lacerations was inversely related to homicide (p\ua0=\ua00.002, OR 0.092). To the best of our knowledge, this is one of very few Italian studies concerning the differential diagnosis between homicidal and suicidal sharp force fatalities. The dynamics of the event is established in most cases by the integrated evaluation of data from crime scene investigation and the autopsy. Nevertheless, in an atypical scenario, a psychopathological\u2013criminological analysis may provide essential elements, and particular attention should be given to the identification of potential explanatory motives

    Low-noise monolithic bipolar front-end for silicon drift detectors

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    Abstract A very low noise, 32-channel preamplifier/shaper chip has been designed for the analogue readout of silicon detectors. The circuit has been optimized in view of the operation of silicon drift detectors, which have very low capacitance and produce gaussian signals of σ of few tens of ns. The chip (OLA) has been designed and manufactured using the SHPi full-custom bipolar process by Tektronix. Each channel is composed by a preamplifier, a shaper and a symmetrical line driver, which allows to drive either a positive and a negative single ended output separately on 50 Ω impedance or a differential twisted pair. The intrinsic peaking time of the circuit is ∼60 ns , and the noise is below 250 electrons at zero input load capacitance. The power consumption is 2 mW/channel, mostly due to the output driver

    Antibiotic resistance, virulence factors, phenotyping, and genotyping of non\u2013escherichia coli enterobacterales from the gut microbiota of healthy subjects

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    Non-Escherichia coli Enterobacterales (NECE) can colonize the human gut and may present virulence determinants and phenotypes that represent severe heath concerns. Most information is available for virulent NECE strains, isolated from patients with an ongoing infection, while the commensal NECE population of healthy subjects is understudied. In this study, 32 NECE strains were isolated from the feces of 20 healthy adults. 16S rRNA gene sequencing and mass spectrometry attributed the isolates to Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Enterobacter aerogenes, Enterobacter kobei, Citrobacter freundii, Citrobacter amalonaticus, Cronobacter sp., and Hafnia alvei, Morganella morganii, and Serratia liquefaciens. Multiplex PCR revealed that K. pneumoniae harbored virulence genes for adhesins (mrkD, ycfM, and kpn) and enterobactin (entB) and, in one case, also for yersiniabactin (ybtS, irp1, irp2, and fyuA). Virulence genes were less numerous in the other NECE species. Biofilm formation was spread across all the species, while curli and cellulose were mainly produced by Citrobacter and Enterobacter. Among the most common antibiotics, amoxicillin-clavulanic acid was the sole against which resistance was observed, only Klebsiella strains being susceptible. The NECE inhabiting the intestine of healthy subjects have traits that may pose a health threat, taking into account the possibility of horizontal gene transfer

    Antibiotic Resistance, Virulence Factors, Phenotyping, and Genotyping of E. coli Isolated from the Feces of Healthy Subjects

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    Escherichia coli may innocuously colonize the intestine of healthy subjects or may instigate infections in the gut or in other districts. This study investigated intestinal E. coli isolated from 20 healthy adults. Fifty-one strains were genotyped by molecular fingerprinting and analyzed for genetic and phenotypic traits, encompassing the profile of antibiotic resistance, biofilm production, the presence of surface structures (such as curli and cellulose), and their performance as recipients in conjugation experiments. A phylogroup classification and analysis of 34 virulence determinants, together with genes associated to the pks island (polyketide-peptide genotoxin colibactin) and conjugative elements, was performed. Most of the strains belonged to the phylogroups B1 and B2. The different phylogroups were separated in a principal coordinate space, considering both genetic and functional features, but not considering pulsed-field gel electrophoresis. Within the B2 and F strains, 12 shared the pattern of virulence genes with potential uropathogens. Forty-nine strains were sensitive to all the tested antibiotics. Strains similar to the potential pathogens innocuously inhabited the gut of healthy subjects. However, they may potentially act as etiologic agents of extra-intestinal infections and are susceptible to a wide range of antibiotics. Nevertheless, there is still the possibility to control infections with antibiotic therapy

    Optimized Variables of the Study of Λb\Lambda_b Polarization

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    The value of the bb-baryon polarization can be extracted from inclusive data at LEP with better than 10\% precision based on current statistics. We present a new variable by which to measure the polarization, which is the ratio of the average electron energy to the average neutrino energy. This variable is both sensitive to polarization and insensitive to fragmentation uncertainties.Comment: 10 pages (LaTeX), 2 figures, MIT-CTP-2270, CERN-PPE/94-0
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