RESUMEN
The multi-staged XENON program at INFN Laboratori Nazionali del Gran Sasso aims to detect dark matter with two-phase liquid xenon time projection chambers of increasing size and sensitivity. The XENONnT experiment is the latest detector in the program, planned to be an upgrade of its predecessor XENON1T. It features an active target of 5.9 tonnes of cryogenic liquid xenon (8.5 tonnes total mass in cryostat). The experiment is expected to extend the sensitivity to WIMP dark matter by more than an order of magnitude compared to XENON1T, thanks to the larger active mass and the significantly reduced background, improved by novel systems such as a radon removal plant and a neutron veto. This article describes the XENONnT experiment and its sub-systems in detail and reports on the detector performance during the first science run.
RESUMEN
We present the measurement of the two-neutrino double-ß decay rate of ^{76}Ge performed with the GERDA Phase II experiment. With a subset of the entire GERDA exposure, 11.8 kg yr, the half-life of the process has been determined: T_{1/2}^{2ν}=(2.022±0.018_{stat}±0.038_{syst})×10^{21} yr. This is the most precise determination of the ^{76}Ge two-neutrino double-ß decay half-life and one of the most precise measurements of a double-ß decay process. The relevant nuclear matrix element can be extracted: M_{eff}^{2ν}=(0.101±0.001).
RESUMEN
We search for tri-nucleon decays of 76Ge in the dataset from the GERmanium Detector Array (GERDA) experiment. Decays that populate excited levels of the daughter nucleus above the threshold for particle emission lead to disintegration and are not considered. The ppp-, ppn-, and pnn-decays lead to 73Cu, 73Zn, and 73Ga nuclei, respectively. These nuclei are unstable and eventually proceed by the beta decay of 73Ga to 73Ge (stable). We search for the 73Ga decay exploiting the fact that it dominantly populates the 66.7 keV 73mGa state with half-life of 0.5 s. The nnn-decays of 76Ge that proceed via 73mGe are also included in our analysis. We find no signal candidate and place a limit on the sum of the decay widths of the inclusive tri-nucleon decays that corresponds to a lower lifetime limit of 1.2×1026 yr (90% credible interval). This result improves previous limits for tri-nucleon decays by one to three orders of magnitude.
RESUMEN
We report on the first search for nuclear recoils from dark matter in the form of weakly interacting massive particles (WIMPs) with the XENONnT experiment, which is based on a two-phase time projection chamber with a sensitive liquid xenon mass of 5.9 ton. During the (1.09±0.03) ton yr exposure used for this search, the intrinsic ^{85}Kr and ^{222}Rn concentrations in the liquid target are reduced to unprecedentedly low levels, giving an electronic recoil background rate of (15.8±1.3) events/ton yr keV in the region of interest. A blind analysis of nuclear recoil events with energies between 3.3 and 60.5 keV finds no significant excess. This leads to a minimum upper limit on the spin-independent WIMP-nucleon cross section of 2.58×10^{-47} cm^{2} for a WIMP mass of 28 GeV/c^{2} at 90% confidence level. Limits for spin-dependent interactions are also provided. Both the limit and the sensitivity for the full range of WIMP masses analyzed here improve on previous results obtained with the XENON1T experiment for the same exposure.
RESUMEN
Multiple viable theoretical models predict heavy dark matter particles with a mass close to the Planck mass, a range relatively unexplored by current experimental measurements. We use 219.4 days of data collected with the XENON1T experiment to conduct a blind search for signals from multiply interacting massive particles (MIMPs). Their unique track signature allows a targeted analysis with only 0.05 expected background events from muons. Following unblinding, we observe no signal candidate events. This Letter places strong constraints on spin-independent interactions of dark matter particles with a mass between 1×10^{12} and 2×10^{17} GeV/c^{2}. In addition, we present the first exclusion limits on spin-dependent MIMP-neutron and MIMP-proton cross sections for dark matter particles with masses close to the Planck scale.
RESUMEN
The ability to detect liquid argon scintillation light from within a densely packed high-purity germanium detector array allowed the Gerda experiment to reach an exceptionally low background rate in the search for neutrinoless double beta decay of 76 Ge. Proper modeling of the light propagation throughout the experimental setup, from any origin in the liquid argon volume to its eventual detection by the novel light read-out system, provides insight into the rejection capability and is a necessary ingredient to obtain robust background predictions. In this paper, we present a model of the Gerda liquid argon veto, as obtained by Monte Carlo simulations and constrained by calibration data, and highlight its application for background decomposition.
RESUMEN
We report on a blinded analysis of low-energy electronic recoil data from the first science run of the XENONnT dark matter experiment. Novel subsystems and the increased 5.9 ton liquid xenon target reduced the background in the (1, 30) keV search region to (15.8±1.3) events/(ton×year×keV), the lowest ever achieved in a dark matter detector and â¼5 times lower than in XENON1T. With an exposure of 1.16 ton-years, we observe no excess above background and set stringent new limits on solar axions, an enhanced neutrino magnetic moment, and bosonic dark matter.
RESUMEN
This corrects the article DOI: 10.1103/PhysRevLett.125.011801.
RESUMEN
Surveys on Serial Transverse Enteroplasty (STEP) published in international literature (1 January 2003- 31 May 2021) were searched. Articles were included from 17 countries: 1/23 comparative and 22/23 cohort studies. STEP was performed on 308 patients: pediatrics, adults, and mixed ages. Pediatric group included 16 studies and the adult 6. Pre-STEP residual small bowell (SB) length for pediatrics and adults ranged from 18 to 26 cm and from 30 to 70 cm, respectively. Post-STEP increased SB length for pediatrics and adults ranged between 42 and 100% and 50% and 176%, respectively. For pediatrics, enteral autonomy was reached in 32.22% of cases, parenteral nutrition (PN) dependence was 36.11%, a repeated STEP procedure (Re-STEP) was needed in 17.22%, and a bowel transplant was performed in 6.11%. In adults, enteral autonomy was achieved in 52.38%, while PN dependence was 37.1%, and no Re-STEP or transplantation were required. For the mixed group, post-STEP bowel length increased from 2 to 50 cm, enteral autonomy was obtained in 43%, PN dependence was 57%, without reported Re-STEP or transplantation. Mortality rates were between 5.55% (pediatric) and 7.14% (adults). Preoperative length with preservation of ileocecal valve represented the main predictive factors to achieve enteral autonomy.
Asunto(s)
Procedimientos Quirúrgicos del Sistema Digestivo , Síndrome del Intestino Corto , Adulto , Niño , Procedimientos Quirúrgicos del Sistema Digestivo/métodos , Objetivos , Humanos , Nutrición Parenteral , Estudios Retrospectivos , Síndrome del Intestino Corto/cirugía , Resultado del TratamientoRESUMEN
The selection of low-radioactive construction materials is of the utmost importance for rare-event searches and thus critical to the XENONnT experiment. Results of an extensive radioassay program are reported, in which material samples have been screened with gamma-ray spectroscopy, mass spectrometry, and 222 Rn emanation measurements. Furthermore, the cleanliness procedures applied to remove or mitigate surface contamination of detector materials are described. Screening results, used as inputs for a XENONnT Monte Carlo simulation, predict a reduction of materials background ( â¼ 17%) with respect to its predecessor XENON1T. Through radon emanation measurements, the expected 222 Rn activity concentration in XENONnT is determined to be 4.2 ( - 0.7 + 0.5 ) µ Bq/kg, a factor three lower with respect to XENON1T. This radon concentration will be further suppressed by means of the novel radon distillation system.
RESUMEN
We report a case of a 73-year-old woman affected by Lemmel's syndrome, a rare type of obstructive jaundice caused by a periampullary duodenal diverticulum. The patient was admitted to the Emergency Department for pneumonia associated with mild epigastric pain and vomiting. While hospitalized for antibiotic treatment, the appearance of jaundice led us to discover a periampullary duodenal diverticulum by endoscopy and CT scan. The jaundice was successfully managed endoscopically with removal of food debris from the diverticulum.
Asunto(s)
Divertículo , Enfermedades Duodenales , Ictericia Obstructiva , Ictericia , Dolor Abdominal/etiología , Anciano , Divertículo/complicaciones , Divertículo/diagnóstico por imagen , Divertículo/cirugía , Enfermedades Duodenales/complicaciones , Enfermedades Duodenales/diagnóstico por imagen , Femenino , Humanos , Ictericia Obstructiva/etiología , SíndromeRESUMEN
The GERmanium Detector Array (Gerda) collaboration searched for neutrinoless double- ß decay in 76 Ge using isotopically enriched high purity germanium detectors at the Laboratori Nazionali del Gran Sasso of INFN. After Phase I (2011-2013), the experiment benefited from several upgrades, including an additional active veto based on LAr instrumentation and a significant increase of mass by point-contact germanium detectors that improved the half-life sensitivity of Phase II (2015-2019) by an order of magnitude. At the core of the background mitigation strategy, the analysis of the time profile of individual pulses provides a powerful topological discrimination of signal-like and background-like events. Data from regular 228 Th calibrations and physics data were both considered in the evaluation of the pulse shape discrimination performance. In this work, we describe the various methods applied to the data collected in Gerda Phase II corresponding to an exposure of 103.7 kg year. These methods suppress the background by a factor of about 5 in the region of interest around Q ß ß = 2039 keV, while preserving ( 81 ± 3 ) % of the signal. In addition, an exhaustive list of parameters is provided which were used in the final data analysis.
RESUMEN
Duodenal follicular lymphoma (DFL) is a rare variety of non-Hodgkin's lymphoma of the gastrointestinal tract that usually carries a favorable course, recognized as a new entity in 2016. It is usually diagnosed at an early stage located predominantly in the second portion of the duodenum. We report the case of a 74-year-old male patient with epigastric pain in whom gastroscopy revealed white mucosal nodules that were pathologically diagnosed as grade 1-2 DFL. Staging investigations revealed secondary lesions in the spleen and at the base of the tongue together with latero-cervical adenopathy. The tumor was stage IV according to the Lugano staging system. We reviewed the recent (last five years) literature defining the importance of combination therapy in the advanced stage. The patient achieved complete remission of the disease through chemoimmunotherapy following the Rituximab-Bendamustine scheme.
Asunto(s)
Linfoma Folicular , Linfoma no Hodgkin , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Duodeno/patología , Humanos , Linfoma Folicular/diagnóstico , Linfoma Folicular/tratamiento farmacológico , Linfoma Folicular/patología , Masculino , Inducción de Remisión , Rituximab/uso terapéuticoRESUMEN
Biliary lithiasis is common worldwide, affecting almost 20% of the general population, though few experience symptoms. The frequency of choledocholithiasis in patients with symptomatic cholelithiasis is estimated to be 10-33%, depending on patients' age. Unlike gallbladder lithiasis, the medical and surgical treatment of common bile duct stones is uncertain, having changed over the last few years. The prior gold standard treatment for cholelithiasis and choledocholithiasis was open cholecystectomy with bile duct clearance, choledochotomy, and/or surgical sphincterotomy. In the last 10-15 years, new treatment approaches to the complex pathology of choledocholithiasis have emerged with the advent of endoscopic retrograde cholangiopancreatography (ERCP), laparoscopic surgery, and advanced diagnostic procedures. Although ERCP followed by laparoscopic cholecystectomy is the preferred mode of management, a single-step strategy (laparo-endoscopic rendezvous) has gained acceptance due to lesser morbidity and a lower risk of iatrogenic damage. Given the above, a tailored approach relying on careful evaluation of the disease is necessary in order to minimize complication risks and overall costs. Yet, the debate remains open, with no consensus on the superiority of laparo-endoscopic rendezvous to more conventional approaches.
Asunto(s)
Colecistectomía Laparoscópica , Coledocolitiasis , Cálculos Biliares , Colangiopancreatografia Retrógrada Endoscópica , Colecistectomía Laparoscópica/efectos adversos , Colecistectomía Laparoscópica/métodos , Coledocolitiasis/diagnóstico por imagen , Coledocolitiasis/cirugía , Cálculos Biliares/complicaciones , HumanosRESUMEN
BACKGROUND: Thoracic outlet syndrome (TOS) represents a clinical condition caused by compression of the neurovascular structures that cross the thoracic outlet. TOS can be classified in: 1) neurogenic TOS (NTOS), 2) venous TOS (VTOS), 3) arterial TOS (ATOS). Many different causes can determine the syndrome: congenital malformations, traumas, and functional impairments. MATERIALS AND METHODS: This manuscript reviews how the congenital malformations play an important role in adult age; however, TOS also affects patients of all ages. RESULTS: Radiological imaging like X-ray (radiography), magnetic resonance and computed tomography can provide useful information to assess TOS causes and decide a potential surgery. 79% of the patients included in the first two stages of nerve, artery, vein (NAV) staging experienced excellent results with kinesiotherapy; whereas patients included in the third and fourth stage of NAV staging were subject to surgery. CONCLUSIONS: The treatment of acute forms of TOS involves thrombolysis and anticoagulant therapy; surgery is appropriate for true NTOS, vascular TOS and in some cases when conservative treatment fails.
Asunto(s)
Síndrome del Desfiladero Torácico , Adulto , Arterias/patología , Humanos , Imagen por Resonancia Magnética/efectos adversos , Radiografía , Síndrome del Desfiladero Torácico/diagnóstico por imagen , Síndrome del Desfiladero Torácico/etiología , Síndrome del Desfiladero Torácico/cirugía , Tomografía Computarizada por Rayos XRESUMEN
The GERmanium Detector Array (Gerda) collaboration searched for neutrinoless double- ß decay in 76 Ge with an array of about 40 high-purity isotopically-enriched germanium detectors. The experimental signature of the decay is a monoenergetic signal at Q ß ß = 2039.061 ( 7 ) keV in the measured summed energy spectrum of the two emitted electrons. Both the energy reconstruction and resolution of the germanium detectors are crucial to separate a potential signal from various backgrounds, such as neutrino-accompanied double- ß decays allowed by the Standard Model. The energy resolution and stability were determined and monitored as a function of time using data from regular 228 Th calibrations. In this work, we describe the calibration process and associated data analysis of the full Gerda dataset, tailored to preserve the excellent resolution of the individual germanium detectors when combining data over several years.
RESUMEN
Neutrinoless double- ß decay of 76 Ge is searched for with germanium detectors where source and detector of the decay are identical. For the success of future experiments it is important to increase the mass of the detectors. We report here on the characterization and testing of five prototype detectors manufactured in inverted coaxial (IC) geometry from material enriched to 88% in 76 Ge. IC detectors combine the large mass of the traditional semi-coaxial Ge detectors with the superior resolution and pulse shape discrimination power of point contact detectors which exhibited so far much lower mass. Their performance has been found to be satisfactory both when operated in vacuum cryostat and bare in liquid argon within the Gerda setup. The measured resolutions at the Q-value for double- ß decay of 76 Ge ( Q ß ß = 2039 keV) are about 2.1 keV full width at half maximum in vacuum cryostat. After 18 months of operation within the ultra-low background environment of the GERmanium Detector Array (Gerda) experiment and an accumulated exposure of 8.5 kg · year, the background index after analysis cuts is measured to be 4 . 9 - 3.4 + 7.3 × 10 - 4 counts / ( keV · kg · year ) around Q ß ß . This work confirms the feasibility of IC detectors for the next-generation experiment Legend.
Asunto(s)
Toma de Decisiones Clínicas/métodos , Tratamiento Conservador/métodos , Procedimientos Quirúrgicos del Sistema Digestivo/métodos , Divertículo , Enfermedades Duodenales , Perforación Intestinal , Tomografía Computarizada por Rayos X/métodos , Anciano de 80 o más Años , Antibacterianos/administración & dosificación , Diagnóstico Diferencial , Divertículo/complicaciones , Divertículo/diagnóstico por imagen , Drenaje/métodos , Enfermedades Duodenales/complicaciones , Enfermedades Duodenales/diagnóstico por imagen , Endoscopía del Sistema Digestivo/métodos , Humanos , Perforación Intestinal/diagnóstico , Perforación Intestinal/fisiopatología , Perforación Intestinal/terapia , Masculino , Nutrición Parenteral Total/métodos , Ajuste de Riesgo/métodos , Medición de Riesgo , Rotura Espontánea/diagnóstico , Rotura Espontánea/fisiopatología , Rotura Espontánea/terapia , Resultado del TratamientoRESUMEN
We report the case of a 87-year-old woman admitted to our Emergency Department for mild abdominal pain associated with vomiting. An abdominal X-ray showed gas present in the portal venules of the left hepatic lobe, a finding associated with numerous surgical and medical conditions. The patient was successfully managed with conservative treatment. Isolated intrahepatic gas is a rare radiologic finding; emergency surgery should be performed only when there are signs of associated acute intestinal infarction.
Asunto(s)
Embolia Aérea/diagnóstico por imagen , Vena Porta/diagnóstico por imagen , Vena Porta/patología , Anciano de 80 o más Años , Embolia Aérea/terapia , Femenino , Humanos , Tomografía Computarizada por Rayos XRESUMEN
OBJECTIVE: The quality assessment process, based on customer satisfaction, is fundamental in the delivery of the best care services. This is most evident in care settings where trainee students are allowed to assist the patients. The purpose of this review is to clarify whether nursing students have an impact on patients' assessment of the quality of their nursing care. MATERIALS AND METHODS: A systematic literature search was carried out using the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines in six databases: PubMed, CINAHL, Cochrane, Web of Science, Scopus, and PsycInfo. Two co-authors independently screened titles, abstracts, and full-text articles, following explicit exclusion and inclusion criteria. Analyses included non-randomized and non-homogeneous samples, involving both selected patients and methods for assessing their satisfaction. RESULTS: After full-text screening, 30 articles were identified, but only 11 were considered pertinent to the topic of the review. The trainee-patient relationship is based on mutual help and can improve the patient experience and trainee learning. The instruments used to measure perceived quality were found to be valid and reliable. CONCLUSIONS: The studies under review show high levels of satisfaction among patients when nursing care is delivered through training, particularly when the patients who agree to be treated by nursing trainees have previous experience of hospitalization and relationships with trainees. Educational background and the empathy and communication skills of both professional nurses and trainees influence patients' perception of the quality of care and their satisfaction with it.