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1.
Phys Rev Lett ; 131(14): 142501, 2023 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-37862664

RESUMO

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).

2.
Eur Phys J C Part Fields ; 83(9): 778, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37674593

RESUMO

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.

3.
Eur Phys J C Part Fields ; 83(4): 319, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37122826

RESUMO

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.

5.
Eur Phys J C Part Fields ; 82(4): 284, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35464994

RESUMO

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.

6.
Eur Phys J C Part Fields ; 81(6): 505, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34720720

RESUMO

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.

7.
Eur Phys J C Part Fields ; 81(8): 682, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34776783

RESUMO

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.

8.
ESMO Open ; 6(1): 100034, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33422766

RESUMO

BACKGROUND: Platinum-based therapy, combined or not with immune checkpoint inhibitors, represents a front-line choice for patients with non-small-cell lung cancer (NSCLC). Despite the improved outcomes in the last years for this malignancy, only a sub-group of patients have long-term benefit. Excision repair cross-complementation group 1 (ERCC1) has been considered a potential biomarker to predict the outcome of platinum-based chemotherapy in NSCLC. However, the ERCC1 gene is transcribed in four splice variants where the isoform 202 was described as the only one active and able to complex Xeroderma pigmentosum group F-complementing protein (XPF). Here, we prospectively investigated if the active form of ERCC1, as assessed by the ERCC1/XPF complex (ERCC1/XPF), could predict the sensitivity to platinum compounds. PATIENTS AND METHODS: Prospectively enrolled, patients with advanced NSCLC treated with a first-line regimen containing platinum were centrally evaluated for ERCC1/XPF by a proximity ligation assay. Overall survival (OS), progression-free survival (PFS) and objective response rate (ORR) were analyzed. RESULTS: The absence of the ERCC1/XPF in the tumor suggested a trend of worst outcomes in terms of both OS [hazard ratio (HR) 1.41, 95% confidence interval (CI) 0.67-2.94, P = 0.373] and PFS (HR 1.61, 95% CI 0.88-3.03, P = 0.123). ORR was marginally influenced in ERCC1/XPF-negative and -positive groups [odds ratio (stable disease + progressive disease versus complete response + partial response) 0.87, 95% CI 0.25-3.07, P = 0.832]. CONCLUSION: The lack of ERCC1/XPF complex in NSCLC tumor cells might delineate a group of patients with poor outcomes when treated with platinum compounds. ERCC1/XPF absence might well identify patients for whom a different therapeutic approach could be necessary.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Proteínas de Ligação a DNA/genética , Endonucleases/genética , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Platina/uso terapêutico , Estudos Prospectivos
9.
Phys Rev Lett ; 125(1): 011801, 2020 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-32678643

RESUMO

We present the first search for bosonic superweakly interacting massive particles (super-WIMPs) as keV-scale dark matter candidates performed with the GERDA experiment. GERDA is a neutrinoless double-ß decay experiment which operates high-purity germanium detectors enriched in ^{76}Ge in an ultralow background environment at the Laboratori Nazionali del Gran Sasso (LNGS) of INFN in Italy. Searches were performed for pseudoscalar and vector particles in the mass region from 60 keV/c^{2} to 1 MeV/c^{2}. No evidence for a dark matter signal was observed, and the most stringent constraints on the couplings of super-WIMPs with masses above 120 keV/c^{2} have been set. As an example, at a mass of 150 keV/c^{2} the most stringent direct limits on the dimensionless couplings of axionlike particles and dark photons to electrons of g_{ae}<3×10^{-12} and α^{'}/α<6.5×10^{-24} at 90% credible interval, respectively, were obtained.

10.
Phys Rev Lett ; 125(25): 252502, 2020 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-33416389

RESUMO

The GERmanium Detector Array (GERDA) experiment searched for the lepton-number-violating neutrinoless double-ß (0νßß) decay of ^{76}Ge, whose discovery would have far-reaching implications in cosmology and particle physics. By operating bare germanium diodes, enriched in ^{76}Ge, in an active liquid argon shield, GERDA achieved an unprecedently low background index of 5.2×10^{-4} counts/(keV kg yr) in the signal region and met the design goal to collect an exposure of 100 kg yr in a background-free regime. When combined with the result of Phase I, no signal is observed after 127.2 kg yr of total exposure. A limit on the half-life of 0νßß decay in ^{76}Ge is set at T_{1/2}>1.8×10^{26} yr at 90% C.L., which coincides with the sensitivity assuming no signal.

11.
Eur Phys J C Part Fields ; 79(11): 978, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31885491

RESUMO

The GERmanium Detector Array (Gerda) is a low background experiment located at the Laboratori Nazionali del Gran Sasso in Italy, which searches for neutrinoless double-beta decay of 76 Ge into 76 Se+2e - . Gerda has been conceived in two phases. Phase II, which started in December 2015, features several novelties including 30 new 76Ge enriched detectors. These were manufactured according to the Broad Energy Germanium (BEGe) detector design that has a better background discrimination capability and energy resolution compared to formerly widely-used types. Prior to their installation, the new BEGe detectors were mounted in vacuum cryostats and characterized in detail in the Hades underground laboratory in Belgium. This paper describes the properties and the overall performance of these detectors during operation in vacuum. The characterization campaign provided not only direct input for Gerda Phase II data collection and analyses, but also allowed to study detector phenomena, detector correlations as well as to test the accuracy of pulse shape simulation codes.

12.
Science ; 365(6460): 1445-1448, 2019 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-31488705

RESUMO

A discovery that neutrinos are Majorana fermions would have profound implications for particle physics and cosmology. The Majorana character of neutrinos would make possible the neutrinoless double-ß (0νßß) decay, a matter-creating process without the balancing emission of antimatter. The GERDA Collaboration searches for the 0νßß decay of 76Ge by operating bare germanium detectors in an active liquid argon shield. With a total exposure of 82.4 kg⋅year, we observe no signal and derive a lower half-life limit of T 1/2 > 0.9 × 1026 years (90% C.L.). Our T 1/2 sensitivity, assuming no signal, is 1.1 × 1026 years. Combining the latter with those from other 0νßß decay searches yields a sensitivity to the effective Majorana neutrino mass of 0.07 to 0.16 electron volts.

13.
Phys Rev Lett ; 120(13): 132503, 2018 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-29694176

RESUMO

The GERDA experiment searches for the lepton-number-violating neutrinoless double-ß decay of ^{76}Ge (^{76}Ge→^{76}Se+2e^{-}) operating bare Ge diodes with an enriched ^{76}Ge fraction in liquid argon. The exposure for broad-energy germanium type (BEGe) detectors is increased threefold with respect to our previous data release. The BEGe detectors feature an excellent background suppression from the analysis of the time profile of the detector signals. In the analysis window a background level of 1.0_{-0.4}^{+0.6}×10^{-3} counts/(keV kg yr) has been achieved; if normalized to the energy resolution this is the lowest ever achieved in any 0νßß experiment. No signal is observed and a new 90% C.L. lower limit for the half-life of 8.0×10^{25} yr is placed when combining with our previous data. The expected median sensitivity assuming no signal is 5.8×10^{25} yr.

14.
Ann Oncol ; 26(10): 2079-84, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26209642

RESUMO

BACKGROUND: The prognostic and predictive role of KRAS mutations in advanced nonsmall-cell lung cancer (NSCLC) is still unclear. TAILOR prospectively assessed the prognostic and predictive value of KRAS mutations in NSCLC patients treated with erlotinib or docetaxel in second line. PATIENTS AND METHODS: NSCLC patients from 52 Italian hospitals were genotyped for KRAS and EGFR mutational status in two independent laboratories. Wild-type EGFR patients (N = 218) received first-line platinum-based chemotherapy and were randomly allocated at progression to erlotinib or docetaxel. Overall survival (OS) according to KRAS mutational status was the primary end point. RESULTS: KRAS mutations were present in 23% of TAILOR randomized cases. The presence of a KRAS mutation did not adversely affect progression-free (PFS) or overall (OS) survival [hazard ratio (HR) PFS = 1.01, 95% confidence interval (CI) 0.71-1.41, P = 0.977; OS = 1.24, 95% CI 0.87-1.77, P = 0.233], nor influenced treatment outcome (test for interaction: OS P = 0.965; PFS P = 0.417). Patients randomized to docetaxel treatment experienced longer survival independently from the KRAS mutational status of their tumors (HR: mutated KRAS 0.81, 95% CI 0.45-1.47; wild-type KRAS 0.79, 95% CI 0.57-1.10). CONCLUSION: In TAILOR, KRAS was neither prognostic nor predictive of benefit for either docetaxel or erlotinib. Docetaxel remains superior independently from KRAS status for second-line treatment in EGFR wild-type advanced NSCLC patients. CLINICAL TRIAL REGISTRATION: NCT00637910.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/genética , Receptores ErbB/genética , Neoplasias Pulmonares/genética , Mutação/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/genética , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Docetaxel , Cloridrato de Erlotinib/administração & dosagem , Seguimentos , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Estadiamento de Neoplasias , Prognóstico , Estudos Prospectivos , Taxa de Sobrevida , Taxoides/administração & dosagem
15.
Phys Rev Lett ; 111(12): 122503, 2013 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-24093254

RESUMO

Neutrinoless double beta decay is a process that violates lepton number conservation. It is predicted to occur in extensions of the standard model of particle physics. This Letter reports the results from phase I of the Germanium Detector Array (GERDA) experiment at the Gran Sasso Laboratory (Italy) searching for neutrinoless double beta decay of the isotope (76)Ge. Data considered in the present analysis have been collected between November 2011 and May 2013 with a total exposure of 21.6 kg yr. A blind analysis is performed. The background index is about 1 × 10(-2) counts/(keV kg yr) after pulse shape discrimination. No signal is observed and a lower limit is derived for the half-life of neutrinoless double beta decay of (76)Ge, T(1/2)(0ν) >2.1 × 10(25) yr (90% C.L.). The combination with the results from the previous experiments with (76)Ge yields T(1/2)(0ν)>3.0 × 10(25) yr (90% C.L.).

16.
Ann Oncol ; 22(10): 2160-5, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21321088

RESUMO

BACKGROUND: Interest in outcomes research (OR) derives from the need to know the value and the effectiveness of health interventions, especially for oncology. We focused our research on OR in breast cancer, providing an overview of the trend of publications. PATIENTS AND METHODS: We carried out a Medline search to retrieve all articles in English published from 2000 through 2007. The abstracts were reviewed and classified according to the research topics and the primary design of the trial. RESULTS: We selected 405 articles: their number remained constant until 2003, rose during 2004-2005 and decreased during the last 2 years. The most common topic was surgery (n = 234), alone or in association with other interventions. The category more investigated was the process. Clinical outcomes, and among them disease-free survival, were more frequent than other outcomes. The median value of 2007 Impact Factor of the journals publishing the selected references was 2.466 (range 0.272-25.547) and the median value of Citation Index was 8 (range 0-143). CONCLUSIONS: Our research showed a decreasing interest in OR during the more recent years. We are hopeful that it will regenerate interest, particularly by the light of the funds allocated to the comparative effectiveness research in the United States.


Assuntos
Neoplasias da Mama/terapia , Pesquisa Comparativa da Efetividade/tendências , Avaliação de Resultados em Cuidados de Saúde/tendências , Feminino , Humanos , Resultado do Tratamento
17.
Arch Womens Ment Health ; 12(4): 239-49, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19415454

RESUMO

The aims of this study were to identify the frequency of the risk factors for postpartum depression (PPD) listed in the Postpartum Depression Predictors Inventory-Revised (PDPI-R) during pregnancy and 1 month after delivery and to determine the predictive validity of the PDPI-R. The study used a prospective cohort design. Women completed the PDPI-R at the 3rd and the 8th months of pregnancy and at the 1st month after childbirth. Women were prospectively followed across three different time points during the postpartum using Structured Clinical Interview for DSM-IV Disorders to determine the presence of major or minor depression. The prenatal version of the PDPI-R administered at two different time points during pregnancy predicted accurately 72.6% and 78.2% of PPD and the full version administered at the 1st month after delivery predicted 83.4% of PPD. The cutoffs identified were 3.5 for the prenatal version and 5.5 for the full version. The PDPI-R is a useful and a valid screening tool for PPD.


Assuntos
Depressão Pós-Parto/diagnóstico , Depressão Pós-Parto/epidemiologia , Escalas de Graduação Psiquiátrica/normas , Adolescente , Adulto , Depressão Pós-Parto/etiologia , Feminino , Humanos , Itália/epidemiologia , Paridade , Gravidez , Cuidado Pré-Natal , Estudos Prospectivos , Curva ROC , Fatores de Risco , Adulto Jovem
18.
Ann Oncol ; 19(11): 1842-6, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18550574

RESUMO

BACKGROUND: Sentinel lymph node biopsy (SLNB) was developed to axillary lymph node dissection (ALND) in the treatment of breast cancer. SLNB is predictive of axillary node status. Major concern is the occurrence of a false-negative SLN. Purpose of this study is to determine the rate of axillary recurrence in our series of unselected patients. PATIENTS AND METHODS: All patients with a negative SLNB from November 1999 to December 2006 have been treated and followed at our unit. Information on patients' characteristics, treatment and follow-up has been collected. RESULTS: Eight-hundred and four patients with negative SLNB did not receive ALND. After a median follow-up of 38.8 months, 21 patients had distant metastases, four had axillary relapse, nine had an in-breast recurrence and two had both. All patients with axillary recurrence received axillary dissection and systemic adjuvant therapy. They are all presently alive and free from disease. CONCLUSION: Data from this series, the largest from a general hospital, showed that isolated axillary node recurrence after negative SLNB is rare (<1%) and comparable with those reported from referral cancer institutions. We confirm that SLNB for the treatment of early breast cancer patients of a community-based hospital is safe and reliable.


Assuntos
Neoplasias da Mama/patologia , Linfonodos/patologia , Recidiva Local de Neoplasia/patologia , Adulto , Idoso , Axila , Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Intervalo Livre de Doença , Feminino , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Radioterapia Adjuvante , Biópsia de Linfonodo Sentinela
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