The Aria cryogenic distillation plant, located in Sardinia, Italy, is a key component of the DarkSide-20k experimental program for WIMP dark matter searches at the INFN Laboratori Nazionali del Gran ...Sasso, Italy. Aria is designed to purify the argon, extracted from underground wells in Colorado, USA, and used as the DarkSide-20k target material, to detector-grade quality. In this paper, we report the first measurement of argon isotopic separation by distillation with the 26 m tall Aria prototype. We discuss the measurement of the operating parameters of the column and the observation of the simultaneous separation of the three stable argon isotopes:
36
Ar
,
38
Ar
, and
40
Ar
. We also provide a detailed comparison of the experimental results with commercial process simulation software. This measurement of isotopic separation of argon is a significant achievement for the project, building on the success of the initial demonstration of isotopic separation of nitrogen using the same equipment in 2019.
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The direct search for dark matter in the form of weakly interacting massive particles (WIMP) is performed by detecting nuclear recoils produced in a target material from the WIMP elastic scattering. ...The experimental identification of the direction of the WIMP-induced nuclear recoils is a crucial asset in this field, as it enables unmistakable modulation signatures for dark matter. The Recoil Directionality (ReD) experiment was designed to probe for such directional sensitivity in argon dual-phase time projection chambers (TPC), that are widely considered for current and future direct dark matter searches. The TPC of ReD was irradiated with neutrons at the INFN Laboratori Nazionali del Sud. Data were taken with nuclear recoils of known directions and kinetic energy of 72 keV, which is within the range of interest for WIMP-induced signals in argon. The direction-dependent liquid argon charge recombination model by Cataudella et al. was adopted and a likelihood statistical analysis was performed, which gave no indications of significant dependence of the detector response to the recoil direction. The aspect ratio
R
of the initial ionization cloud is
R
<
1.072
with 90 % confidence level.
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The activation of materials due to exposure to cosmic rays may become an important background source for experiments investigating rare event phenomena. DarkSide-20k, currently under construction at ...the Laboratori Nazionali del Gran Sasso, is a direct detection experiment for galactic dark matter particles, using a two-phase liquid-argon Time Projection Chamber (TPC) filled with 49.7 tonnes (active mass) of Underground Argon (UAr) depleted in 39Ar. Despite the outstanding capability of discriminating γ/β background in argon TPCs, this background must be considered because of induced dead time or accidental coincidences mimicking dark-matter signals and it is relevant for low-threshold electron-counting measurements. Here, the cosmogenic activity of relevant long-lived radioisotopes induced in the experiment has been estimated to set requirements and procedures during preparation of the experiment and to check that it is not dominant over primordial radioactivity; particular attention has been paid to the activation of the 120 t of UAr used in DarkSide-20k. Expected exposures above ground and production rates, either measured or calculated, have been considered in detail. From the simulated counting rates in the detector due to cosmogenic isotopes, it is concluded that activation in copper and stainless steel is not problematic. The activity of 39Ar induced during extraction, purification and transport on surface is evaluated to be 2.8% of the activity measured in UAr by DarkSide-50 experiment, which used the same underground source, and thus considered acceptable. Other isotopes in the UAr such as 37Ar and 3H are shown not to be relevant due to short half-life and assumed purification methods.
The dual-phase liquid argon time projection chamber is presently one of the leading technologies to search for dark matter particles with masses below 10 GeV/c\(^2\). This was demonstrated by the ...DarkSide-50 experiment with approximately 50 kg of low-radioactivity liquid argon as target material. The next generation experiment DarkSide-20k, currently under construction, will use 1,000 times more argon and is expected to start operation in 2027. Based on the DarkSide-50 experience, here we assess the DarkSide-20k sensitivity to models predicting light dark matter particles, including Weakly Interacting Massive Particles (WIMPs) and sub-GeV/c\(^2\) particles interacting with electrons in argon atoms. With one year of data, a sensitivity improvement to dark matter interaction cross-sections by at least one order of magnitude with respect to DarkSide-50 is expected for all these models. A sensitivity to WIMP--nucleon interaction cross-sections below \(1\times10^{-42}\) cm\(^2\) is achievable for WIMP masses above 800 MeV/c\(^2\). With 10 years exposure, the neutrino fog can be reached for WIMP masses around 5 GeV/c\(^2\).
Experiments aimed at direct searches for WIMP dark matter require highly effective reduction of backgrounds and control of any residual radioactive contamination. In particular, neutrons interacting ...with atomic nuclei represent an important class of backgrounds due to the expected similarity of a WIMP-nucleon interaction, so that such experiments often feature a dedicated neutron detector surrounding the active target volume. In the context of the development of DarkSide-20k detector at INFN Gran Sasso National Laboratory (LNGS), several R&D projects were conceived and developed for the creation of a new hybrid material rich in both hydrogen and gadolinium nuclei to be employed as an essential element of the neutron detector. Thanks to its very high cross-section for neutron capture, gadolinium is one of the most widely used elements in neutron detectors, while the hydrogen-rich material is instrumental in efficiently moderating the neutrons. In this paper results from one of the R&Ds are presented. In this effort the new hybrid material was obtained as a poly(methyl methacrylate) (PMMA) matrix, loaded with gadolinium oxide in the form of nanoparticles. We describe its realization, including all phases of design, purification, construction, characterization, and determination of mechanical properties of the new material.
The direct search for dark matter in the form of weakly interacting massive particles (WIMP) is performed by detecting nuclear recoils (NR) produced in a target material from the WIMP elastic ...scattering. A promising experimental strategy for direct dark matter search employs argon dual-phase time projection chambers (TPC). One of the advantages of the TPC is the capability to detect both the scintillation and charge signals produced by NRs. Furthermore, the existence of a drift electric field in the TPC breaks the rotational symmetry: the angle between the drift field and the momentum of the recoiling nucleus can potentially affect the charge recombination probability in liquid argon and then the relative balance between the two signal channels. This fact could make the detector sensitive to the directionality of the WIMP-induced signal, enabling unmistakable annual and daily modulation signatures for future searches aiming for discovery. The Recoil Directionality (ReD) experiment was designed to probe for such directional sensitivity. The TPC of ReD was irradiated with neutrons at the INFN Laboratori Nazionali del Sud, and data were taken with 72 keV NRs of known recoil directions. The direction-dependent liquid argon charge recombination model by Cataudella et al. was adopted and a likelihood statistical analysis was performed, which gave no indications of significant dependence of the detector response to the recoil direction. The aspect ratio R of the initial ionization cloud is estimated to be 1.037 +/- 0.027 and the upper limit is R < 1.072 with 90% confidence level
Dark matter lighter than 10 GeV/c\(^2\) encompasses a promising range of candidates. A conceptual design for a new detector, DarkSide-LowMass, is presented, based on the DarkSide-50 detector and ...progress toward DarkSide-20k, optimized for a low-threshold electron-counting measurement. Sensitivity to light dark matter is explored for various potential energy thresholds and background rates. These studies show that DarkSide-LowMass can achieve sensitivity to light dark matter down to the solar neutrino floor for GeV-scale masses and significant sensitivity down to 10 MeV/c\(^2\) considering the Migdal effect or interactions with electrons. Requirements for optimizing the detector's sensitivity are explored, as are potential sensitivity gains from modeling and mitigating spurious electron backgrounds that may dominate the signal at the lowest energies.
A1 The outcome of patients with recurrent versus non-recurrent pneumococcal meningitis in a tertiary health-care hospital in Bucharest
Cristian-Mihail Niculae, Eliza Manea, Raluca Jipa, Simona ...Merisor, Ruxandra Moroti, Serban Benea, Adriana Hristea
A2 Influence of bacteriophages on sessile Gram-positive and Gram-negative bacteria
Alina Cristina Neguț, Oana Săndulescu, Anca Streinu-Cercel, Dana Mărculescu, Magdalena Lorena Andrei, Veronica Ilie, Marcela Popa, Coralia Bleotu, Carmen Chifiriuc, Mircea Ioan Popa, Adrian Streinu-Cercel
A3 The utility of inflammatory biomarkers in the prognostic evaluation of septic patients – past, present and future
Alina Orfanu, Cristina Popescu, Anca Leuștean, Remulus Catană, Anca Negru, Alexandra Badea, Radu Orfanu, Cătălin Tilișcan, Victoria Aramă, Ştefan Sorin Aramă
A4 Etiologic and clinical features of bacterial meningitis in infants
Constanța-Angelica Vișan, Anca-Cristina Drăgănescu, Anuța Bilașco, Camelia Kouris, Mădălina Merișescu, Magdalena Vasile, Diana-Maria Slavu, Sabina Vintilă, Endis Osman, Alina Oprea, Sabina Sandu, Monica Luminos
A5 The diagnostic and prognostic role of neutrophil to lymphocyte count ratio in sepsis
Alina Orfanu, Victoria Aramă, Ştefan Sorin Aramă, Anca Leuştean, Remulus Catană, Anca Negru, Gabriel Adrian Popescu, Cristina Popescu
A6 Whooping cough in a HIV positive patient
Ramona Georgiana Stanculete, Ana Vaduva Enoiu, Adelina Raluca Marinescu, Voichita Lazureanu
A7
Cronobacter sakazakii
sepsis in varicella patient
Adelina-Raluca Marinescu, Alexandru Crișan, Voichița Lăzureanu, Virgil Musta, Narcisa Nicolescu, Ruxandra Laza
A8 Anaerobes an underdiagnosed cause of prosthesis joint infection
Anca-Ruxandra Negru, Daniela-Ioana Munteanu, Raluca Mihăilescu, Remulus Catană, Olga Dorobăț, Alexandru Rafila, Emilia Căpraru, Marius Niculescu, Rodica Marinescu, Olivera Lupescu, Vlad Predescu, Adrian Streinu-Cercel, Victoria Aramă, Daniela Tălăpan
A9
Streptococcus pneumoniae
meningitis presenting with normal CSF – case presentation
Ramona Ștefania Popescu, Luminița Bradu, Dragoș Florea, Adrian Streinu-Cercel
A10 Extrapulmonary manifestations of infection with
Mycoplasma pneumoniae
– study on 24 cases
Daniela Anicuta Leca, Elena Bunea, Andra Teodor, Egidia Miftode
A11 The molecular diagnosis of severe bacterial sepsis in pediatric population
Mădălina Merișescu, Gheorghiță Jugulete, Adrian Streinu-Cercel, Dragoș Florea, Monica Luminos
A12 Acute
Staphylococcus aureus
endocarditis with multiple septic complications in a patient with diabetes mellitus – case presentation
Ramona Ștefania Popescu, Anamaria Dobrotă, Adina Ilie, Liliana Lucia Preoțescu
A13 Is
Streptococcus suis
meningitis an under-diagnosed zoonosis?
Adriana Hristea, Raluca Jipa, Nicoleta Irimescu, Irina Panait, Eliza Manea, Simona Merisor, Cristian Niculae, Daniela Tălăpan
A14
Klebsiella pneumoniae
isolated from blood. Antimicrobial resistance – past and present
Liana Cătălina Gavriliu, Otilia Elisabeta Benea, Șerban Benea, Alexandru Rafila, Olga Dorobăț, Mona Popoiu
A15 Antibiotics resistance in
Staphylococcus aureus
isolated from blood cultures
Livia Dragonu, Augustin Cupşa, Iulian Diaconescu, Irina Niculescu, Lucian Giubelan, Florentina Dumitrescu, Andreea Cristina Stoian, Camelia Guţă, Simona Puiu
A16 Predominance of CTX-M enzymes in extended-spectrum β-lactamase-producing Enterobacteriaceae in two hospitals of Quebec City
Bunescu Irina, Marilyse Vallée, Ann Huletsky, Dominique K. Boudreau, Ève Bérubé, Richard Giroux, Jean Longtin, Yves Longtin, Michel G. Bergeron
A17 Postoperative meningoencephalitis with
Acinetobacter baumannii
XDR – a therapeutic challenge - Case report
Cleo Nicoleta Roșculeț, Dalila-Ana Toma, Catrinel Ciuca, Daniela Tălăpan, Cătălin Apostolescu, Andrei Rogoz, Andrei Stangaciu, Viorica Mitescu, Tudor Vladoiu, Doina Iovănescu
A18 Septic arthritis with
Burkholderia cepacia
Michaela Oana, Simona Costin
A19 A novel approach for managing hard-to-treat infections
Alina Cristina Neguț, Oana Săndulescu, Anca Streinu-Cercel, Maria Magdalena Moțoi, Mircea Ioan Popa, Adrian Streinu-Cercel
A20 Nineteen months surveillance for multidrug resistant organisms (MDRO) by detecting asymptomatic colonization
Daniela Tălăpan, Olga Mihaela Dorobăț, Mona Popoiu, Alexandru Mihai, Doina Iovănescu, Cleo Roşculeț, Cătălin Apostolescu, Gabriel-Adrian Popescu, Adrian Abagiu, Ruxandra Moroti-Constantinescu, Adriana Hristea, Victoria Aramă, Otilia Benea, Mădălina Simoiu, Rodica Bacruban, Adrian Streinu-Cercel, Alexandru Rafila
A21 Antimicrobial resistance of Gram-positive cocci isolated from clinical specimens in the National Institute of Infectious Diseases “Prof Dr. Matei Balș” between 2009–2015
Olga Mihaela Dorobăț, Daniela Tălăpan, Alexandru Mihai, Ioana Bădicuț, Mona Popoiu, Alina Borcan, Alexandru Rafila
A22 The high percentage of carbapenem-resistant Gram-negative bacilli in Romania: an analysis and some proposals
Gabriel Adrian Popescu
A23 Etiological, clinical and therapeutic considerations on 78 cases of healthcare associated meningitis or ventriculitis admitted in the “Sf. Parascheva” infectious diseases clinical hospital, Iași, from 2011 to 2015
Mihnea Hurmuzache, Georgiana Enache, Alexandra Ciocan, Mircea Bararu, Madalina Popazu
A24 Nosocomial infection dynamics in an Intensive Care Department – an overview (epidemiological and clinical monitoring, advanced therapeutic intervention).
Doina Viorica Iovănescu, Cleo Nicoleta Roșculeț, Andrei Rogoz Cătălin Gabriel Apostolescu, Viorica Mitescu
,
Tudor Vladoiu, Dalila Toma, Catrinel Ciuca
A25 Safety and efficacy of interferon free treatment in patients with HCV chronic hepatitis- experience of a single Internal Medicine center
Laura Iliescu, Georgiana Minzala, Letitia Toma, Mihaela Baciu, Alina Tanase, Carmen Orban
A26 Viusid in treatment of chronic viral hepatitis B and C
Victor Pantea, Gheorghe Placinta, Valentin Cebotarescu, Lilia Cojuhari, Paulina Jimbei
A27 The management of hyperbilirubinemia in HCV cirrhotic patients who underwent therapy with direct acting antivirals
Cristina Popescu, Anca Leuștean, Cristina Dragomirescu, Alina Orfanu, Cristina Murariu, Laurențiu Stratan, Alexandra Badea, Cătălin Tilișcan, Daniela Munteanu, Raluca Năstase, Violeta Molagic, Mihaela Rădulescu, Remulus Catana, Victoria Aramă
A28 The efficacy of ombitasvir-paritaprevir/ritonavir, dasabuvir and ribavirin in patients with genotype 1 HCV compensated cirrhosis
Cristina Popescu, Laurențiu Stratan, Remulus Catana, Anca Leuștean, Cristina Dragomirescu, Alexandra Badea, Cristina Murariu, Raluca Năstase, Violeta Molagic, Daniela Munteanu, Cătălin Tilișcan, Mihaela Rădulescu, Alina Orfanu, Ioan Diaconu, Anca Negru, Iulia Bodosca, Violeta Niță, Victoria Aramă
A29 The efficacy of direct acting antivirals regimen without ribavirin in HCV genotype 1b infected patients with compensated cirrhosis
Anca Leuștean, Victoria Aramă, Alina Orfanu, Remulus Catana, Laurențiu Stratan, Cristina Dragomirescu, Cristina Murariu, Alexandra Badea, Cătălin Tilișcan, Daniela Munteanu, Violeta Molagic, Raluca Năstase, Mihaela Rădulescu, Cristina Popescu
A30 Liver decompensation during ombitasvir-paritaprevir/ritonavir-dasabuvir and ribavirin regimen in HCV infected patients with Child-Pugh A cirrhosis
Cristina Popescu, Cristina Dragomirescu, Anca Leuștean, Cristina Murariu, Laurențiu Stratan, Alexandra Badea, Remulus Catană, Alina Orfanu, Raluca Mihaela Năstase, Violeta Molagic, Daniela Munteanu, Cătălin Tilișcan, Victoria Aramă
A31 The safety of direct acting antivirals in HCV compensated cirrhotic patients - an interim analysis
Victoria Aramă, Remulus Catană, Cristina Dragomirescu, Cristina Murariu, Anca Leuștean, Laurențiu Stratan, Alexandra Badea, Alina Orfanu, Anca Negru, Raluca Năstase, Violeta Molagic, Daniela Munteanu, Cătălin Tilișcan, Mihaela Rădulescu, Ioan Diaconu, Violeta Niță, Iulia Bodoșca, Cristina Popescu
A32 The access of patients with HCV compensated cirrhosis to the National Program of therapy with direct acting antivirals
Cristina Popescu, Alexandra Badea, Anca Leuștean, Alina Orfanu, Anca Negru, Laurențiu Stratan, Cristina Dragomirescu, Remulus Catană, Cristina Murariu, Violeta Molagic, Raluca Năstase, Cătălin Tilișcan, Daniela Munteanu, Mihaela Rădulescu, Ioan Diaconu, Violeta Niță, Iulia Bodoșca, Victoria Aramă
A33 Severe reactivation of chronic hepatitis B after discontinuation of nucleos(t)ide analogues – a case series
Cristina Popescu, Alina Orfanu, Anca Leuștean, Alexandra Badea, Laurențiu Stratan, Remulus Catană, Cătălin Tilișcan, Victoria Aramă
A34 The dynamic of hematological disorders during direct acting antivirals therapy for HCV compensated cirrhosis
Cristina Popescu, Cristina Murariu, Cristina Dragomirescu, Anca Leuștean, Laurențiu Stratan, Alina Orfanu, Alexandra Badea, Remulus Catană, Anca Negru, Cătălin Tilișcan, Daniela Munteanu, Mihaela Rădulescu, Violeta Molagic, Raluca Mihaela Năstase, Ioan Alexandru Diaconu, Iulia Bodoșca, Violeta Niță, Victoria Aramă
A35 Behaviors, attitudes and risk factors for viral hepatitis in international medical students vs. the general population in Romania
Yagmur Erturk, Oana Săndulescu, Alina Cristina Neguț, Claudiu Mihai Șchiopu, Adrian Streinu-Cercel, Anca Streinu-Cercel
A36 Characteristics of hepatitis C virus reactivation due to immunosuppressive therapy in Romanian HCV infected patients with hematological malignancies
Violeta Molagic, Cătălin Tilișcan, Cristina Popescu, Raluca Mihăilescu, Daniela Munteanu, Raluca Năstase, Anca Negru, Angelica Tenita, Victoria Aramă, Ștefan Sorin Aramă
A37 The dynamic IFN-gamma serum levels during successful peginterferon-a 2a/ribavirin therapy in HCV chronic infection
Simona Alexandra Iacob, Diana Gabriela Iacob, Monica Luminos
A38 Overlapping risk factors for transmission of HBV, HCV and HIV in the general population in Romania
Anca Streinu-Cercel, Oana Săndulescu, Mioara Predescu, Alexandra Mărdărescu, Cătălin Tilișcan, Mihai Săndulescu, Claudiu Mihai Șchiopu, Adrian Streinu-Cercel
A3
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