bluuebunny/crossref_metadata_2025 huggingface dataset:
Outcomes for patients with metastatic solid malignancies who achieve a complete response on an immune checkpoint inhibitor.
Authors: Wee Christopher Eing , Molina Julian R.
Published: February 2020

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Background: Use of immune checkpoint inhibitors (ICI) in metastatic solid malignancies can occasionally result in a complete response (CR). There is limited long-term data regarding outcomes for patients who achieve a CR on ICIs. Methods: We screened the Mayo Clinic electronic medical record using an institutional database query program to identify patients whose records contained keywords such as “pembrolizumab” and “complete response” or “no evidence of disease.” Patients were included if they had measurable metastatic solid tumor disease prior to initiation of ICI and if they had a CR defined by two consecutive imaging studies at least twelve weeks apart. Exclusion criteria included oligometastatic disease treated with locoregional therapy or presence of a second confounding malignancy. Results: One-hundred four patients with a CR on pembrolizumab met criteria. Most (71.1%) patients had melanoma and 63/103 (61.2%) received had received the ICI during the first line of metastatic systemic therapy. Additional characteristics are in Table. At a median follow-up of 35.8 months (6.1-87.7), patients had received ICI for a median of 12.1 months (1.5-46.7). The vast majority of patients who stopped ICI did so electively (for reasons other than disease progression). Of 88 elective discontinuations, only 7 patients had disease recurrence after a median follow-up from start of ICI of 40.5 months. Conclusions: Patients with a metastatic solid malignancy who achieve a CR to pembrolizumab appear to maintain remissions off therapy, with low rates of relapse. Further outcomes will be explored, including analyzing and characterizing a sub-group of “hyper-responders” and patients receiving other ICI agents. [Table: see text]
Dermatologic adverse events with immune checkpoint blockade: Systematic review and meta-analysis.
Authors: Naha Kushal , Chintalacheruvu Lakshmi Manogna , Doll Donald C. , Naha Sowjanya
Published: February 2020

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Background: Immune checkpoint blockade is known to be associated with various dermatologic adverse events. However, these adverse effects have not been studied in a systematic manner. This is especially relevant considering the rapidly increasing number of immune checkpoint inhibitors that are now available. Methods: We searched for eligible studies in PubMed and Google scholar. We reviewed randomized controlled trials involving cancer patients treated with immune checkpoint inhibitors - PD1 inhibitors, PDL1 inhibitors and CTLA4 inhibitors and for dermatologic adverse effects. A total of 47 randomized controlled trials involving 11875 patients met eligibility criteria for our study. Results: Incidence rate of all grade dermatologic adverse effects was 40.6% (95% confidence interval [CI], 39.4-41.7%). Most common adverse effects included pruritus (17.3%) (95% confidence interval [CI] 16.6-18.1%), undifferentiated rash (15.1%) (95% confidence interval [CI] 14.4-15.9%), vitiligo (3.6%) (95% confidence interval [CI] 3.2-3.9%), maculopapular rash (2.3%) (95% confidence interval [CI] 2.1-2.6%), stomatitis (0.7%) (95% confidence interval [CI] 0.55-0.92%) and dry skin (0.7%) (95% confidence interval [CI] 0.5-0.8%). Less common adverse events include palmoplantar erythrodysesthesia, pemphigoid skin reactions, lichen planus and hyperhidrosis. Grade 3 and higher adverse effects were seen in 1.3% of patients (95% confidence interval [CI] 1.1-1.6%). Conclusions: A wide range of dermatologic adverse effects can be seen with immune checkpoint blockade. While the majority of these events are of grade 1-2, they can occasionally be severe and even life threatening. Patients receiving immune checkpoint blockade should be closely monitored for dermatologic adverse effects.
Immunotherapy in metastatic melanoma: A sociodemographic analysis of the National Cancer Database.
Authors: Patel Amie , Moyers Justin , Nagaraj Gayathri
Published: February 2020

87

Background: Metastatic melanoma carries poor prognosis and traditional chemotherapy has limited efficacy, but immune checkpoint inhibitors (ICIs) have drastically improved disease outcomes since first approved in 2011. Access to these costly agents in the real-world setting can be challenging. We aimed to assess the demographic and socioeconomic factors associated with receipt of immunotherapy in Stage IV melanoma using National Cancer Database (NCDB). Methods: NCDB first classified ICIs as immunotherapy agents in 2013, hence we queried the database to identify patients with Stage IV melanoma from 2013 to 2016. Patients were divided into receipt of immunotherapy or no receipt of immunotherapy; those without documentation of either were excluded. Factors compared between the two groups included age, sex, diagnosis year, Charlson-Deyo score, insurance and state Medicaid expansion status, income, treatment region, and facility type. Survival analyses were performed by Kaplan-Meier method. Logistic Regression was used to examine factors associated with immunotherapy receipt. Results: 9512 Stage IV melanoma patients had documented immunotherapy status during 2013 to 2016. 36.0% of patients received immunotherapy. Median overall survival (mOS) for all-comers was 10.1 months with improved survival for those who received immunotherapy compared to those who did not (mOS 18.4 v 7.4 months; p<0.01). Regression analysis revealed increased receipt of immunotherapy was associated with diagnosis in states with Medicaid expansion (OR: 1.16, 95% CI:1.002-0.1.340) compared to non-expansion; west north central (OR:1.433; 95%CI:1.139-1.804) and mountain (OR:1.433; 95%CI:1.132-1.813) regions when compared to pacific; academic/research program (OR:1.923; 95%CI:1.592-2.323) and integrated cancer programs (OR:1.362; 95%CI:1.094-1.695) compared to community program. Charlson-Deyo Scores of 1-3, lower Income, increased age, and less high school graduation were associated with decreased immunotherapy receipt. Conclusions: Improved survival is realized in those who receive immunotherapy for stage IV melanoma. Socio-demographic factors show discrepant receipt of immunotherapy.
Clinical characteristics of nivolumab-induced radiation recall pneumonitis in patients with non-small cell lung cancer: A multicenter real-world analysis of 669 patients.
Authors: Shimokawaji Tadasuke , Narita Shoko , Naito Tomoyuki , Udagawa Hibiki , Goto Koichi , Miyawaki Taichi , Mamesaya Nobuaki , Nakashima Kazuhisa , Kenmotsu Hirotsugu , Kato Terufumi , Hakozaki Taiki , Okuma Yusuke , Nakamura Masaki , Nakayama Yuko , Watanabe Hirokazu , Kusumoto Masahiko , Ohe Yuichiro , Horinouchi Hidehito
Published: February 2020

88

Background: Immune checkpoint inhibitors can cause immune-related pneumonitis in lung cancer patients. Some of those patients with history of previous thoracic radiation therapy (TRT) are reported to show radiation recall pneumonitis (RRP) pattern. In this multicenter retrospective study, we analyzed the patient background and clinical characteristics of RRP. Methods: Medical records of non-small cell lung cancer patients, who received nivolumab between December 2015 and March 2017, were retrospectively reviewed. Incidence of pneumonitis, and incidence, risk factors and clinical characteristics of RRP were analyzed at 5 institutions. Person’s chi-square test (age, sex, smoking history, performance status at the start of nivolumab treatment, background lung disease, history of previous radiation pneumonitis, total dose, volume receiving more than 20Gy, 30Gy, mean lung dose of TRT, and duration after TRT) was conducted to identify potential risk factors of RRP. RRP was defined as fibrosis or consolidation occurring in the previous TRT field, and imaging analysis was conducted by two individual radiologists. Results: A total of 669 patients were evaluated, and the incidences of all-grade and ≥ grade 3 pneumonitis were 8.8% (59/669) and 6.2% (18/669), respectively. Incidence of RRP was 5.4% (14/257) among patients with history of previous TRT. There were no significant risk factors for RRP. Although we did not find significant difference between the severity of RRP pattern and other radiological patterns of pneumonitis, patients with RRP showed better outcome. All patients recovered from RRP without no exacerbation or death, compared to 9.3% of exacerbation or death in other patterns of pneumonitis. Conclusions: Incidence of RRP was 5.4% among patients with history of previous TRT, although there were no significant risk factors of RRP. Patients with RRP pattern showed relatively better outcome.
Immune-related adverse events and efficacy outcomes in patients treated with immunotherapy: A systematic review and meta-analysis.
Authors: Druyts Eric , Boye Mark , Agg Himani , Muehlenbein Catherine , Frederickson Andrew , Bayt Theresa
Published: February 2020

92

Background: Immunotherapy (IO) can lead to immune-related adverse events (irAEs). Evidence on the association of irAEs and efficacy is limited. Methods: We conducted a systematic review in MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials (inception to July 1, 2019) to identify randomized controlled trials (RCTs) reporting irAEs, incidence and efficacy data for pembrolizumab (PEM), nivolumab (NIVO), ipilimumab (IPI), atezolizumab, avelumab, durvalumab, and aldesleukin in lung, renal, head and neck cancer, and melanomas. RCTs assessing IO monotherapy or IO combinations in at least one arm were included. Evaluated outcomes were 1) irAE incidence (rash, pruritis, diarrhea, colitis, hypothyroidism, hyperthyroidism, transaminitis, hypophysitis, pneumonitis, arthralgia, anemia, and hepatitis); and 2) efficacy (response and survival). irAE incidence data will be pooled and meta-analysis performed to assess the association of irAEs with efficacy; heterogeneity between RCTs will be evaluated. Results: Fifty RCTs were included: IOs were compared to chemotherapy or chemotherapy-combinations (19), to other interventions (8), to placebo (3), and head-to-head (20). irAE reporting and definitions were heterogeneous across RCTs. The most common all-grade irAEs were skin, GI, and endocrine. For skin irAEs, rash ranged from 0% (PEM 2 mg/kg, n = 6) to 73% (NIVO + IPI, n = 11); pruritus was from 1% (PEM 2 mg/kg, n = 89) to 50% (NIVO + IPI, n = 6). For GI irAEs, diarrhea ranged from 0% (PEM 2 mg/kg, n = 6) to 64% (NIVO + IPI, n = 11); colitis was from 0% (NIVO 3 mg/kg, n = 98) to 23% (NIVO + IPI, n = 94). For endocrine irAEs, hypothyroidism ranged from 0% (NIVO 3 mg/kg, n = 12) to 83% (NIVO + IPI, n = 6), hyperthyroidism was from 0% (PEM 2 mg/kg, n = 6 and IPI 3 mg/kg, n = 46) to 27% (NIVO + IPI, n = 11), and hypophysitis was from 0% (PEM 10 mg/kg, n = 84 and NIVO 3 mg/kg, n = 25) to 26% (NIVO + IPI, n = 35). Liver, pulmonary, and musculoskeletal irAEs, and anemia, were reported less frequently and with lower incidence. Conclusions: irAEs are increasingly reported in IO RCTs, but lack reporting and definition consistency. The meta-analysis results may provide clarity on irAEs incidence and association with efficacy.
Use of glycosylated hemoglobin and C-peptide levels in the diagnosis and prevention of type 1 diabetes mellitus as an immune-related adverse event secondary to treatment with immunotherapy in solid tumors.
Authors: Olivares Hernández Alejandro J. , Escala Cornejo Roberto Andrés , Figuero Pérez Luis , Vidal Rosario , Escalera Martín Elena , Claros Ampuero Juncal , Casado Elía Diego , García Muñoz María , Amores Martin Arantzazu , Rodriguez Cesar Augusto , González Sarmiento Rogelio , Miramontes González José Pablo , Cruz-Hernández Juan J.
Published: February 2020

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Background: Type 1 diabetes mellitus (T1D) as an immune-related adverse event (irAE) is found in 0.5-5% of all patients treated with immunotherapy (IT) and it is associated with life-threatening complications. However, there are no official guidelines that suggest methods for the prevention and monitoring of T1D during treatment with IT. The algorithms described in the literature only assess the fasting blood sugar levels for prevention and monitoring. The objective of this review is to find factors that establish a relationship with the appearance of T1D as an irAE and to put forward a new algorithm for prevention and monitoring based on those findings. Methods: We carried out a clinical review of the cases published in the literature on T1D secondary to IT between 2012 and 2019. Through a statistical analysis, the relevant clinical characteristics will be determined, together with the factors related to the appearance of T1D, which will make it possible to put forward a new algorithm for the prevention and monitoring of T1D during treatment with IT for solid tumors. Results: Eighty one cases were reported. Of the reported cases, 90% were associated with Nivolumab or Pembrolizumab. The median age was 67 years (23-84 years), and the patients were predominantly men. The average number of administered doses was 5.3 with a lapse of 14.6 weeks from the administration of the first dose until diagnosis. In 48 cases (59%) the levels of C-peptide were low or undetectable, and the glycosylated hemoglobin (HbA1c) levels were elevated by an average of 8.8% (73 mmol/mol). Anti-β-cell antibodies were found in less than half of the patients (44). Diabetic ketoacidosis was observed at diagnosis in 61 patients (75%). Conclusions: Based on the results of our review, we propose including the levels of C-peptide and HbA1C in the usual protocol for the management of adverse events related to IT. Our algorithm suggests that the levels must be determined prior to the IT, after the first 2 cycles, and then every 2 months. This algorithm will enable the prevention, early diagnosis and monitoring of T1D during treatment with IT.
Oxyntomodulin and Glicentin May Predict the Effect of Bariatric Surgery on Food Preferences and Weight Loss
Authors: Nielsen Mette S , Ritz Christian , Wewer Albrechtsen Nicolai J , Holst Jens Juul , le Roux Carel W , Sjödin Anders
Published: February 2020

Background

Alterations in several gastrointestinal hormones are implicated in the postoperative suppression of food intake leading to weight loss after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). The aim was to evaluate changes in responses of gastrointestinal hormones after RYGB and SG and the associations of these changes with weight loss, energy intake, and food preferences.

Methods

Forty-two subjects with severe obesity were included (32 RYGB; 10 SG). Postprandial responses of glicentin, oxyntomodulin, glucagon-like peptide-1 (GLP-1), peptide YY (PYY), and ghrelin were measured before and 6 months after surgery. Energy intake and energy density were assessed before and 6 months after surgery using a buffet meal test and weight loss was assessed 18 months after surgery.

Results

Postprandial concentrations of glicentin, oxyntomodulin, GLP-1, and ghrelin differed between RYGB and SG (all P ≤ .02). Enhanced responses of glicentin and oxyntomodulin predicted a greater weight loss (both P < .01) and were associated with a larger decrease in energy density (P ≤ .04). No associations were found for GLP-1, PYY, and ghrelin, and changes were not associated with changes in energy intake. When combing all hormones, 60%, 19%, and 33% of the variations in weight loss, energy intake, and energy density, respectively, could be explained.

Conclusion

Postprandial responses of gastrointestinal hormones differed between RYGB and SG. Enhanced responses of glicentin and oxyntomodulin predicted a better weight loss and were associated with a decreased preference for energy-dense foods. Replication of these results could imply an opportunity to identify patients in need of additional support after surgical treatments of obesity.
The Wrong Marshall: Notes on the Marshall family in Response to Biographies of the Economist, Alfred Marshall
Authors: Stevens Megan , Stevens Alun
Published: February 2020

Professor Ronald H. Coase included his essays on Alfred Marshall in his book, Essays on Economics and Economists. Because of Coase’s standing as a Nobel laureate and professor of economics at the University of Chicago, these essays have been relied on by scholars, authors, and historians researching Alfred Marshall and the wider Marshall family, including Professor Peter Groenewegen for his seminal biography, A Soaring Eagle: Alfred Marshall 1842–1924. This research shows that the supposed meeting between Charles Henry Marshall, Alfred’s uncle, and Nehemiah Bartley on the Turon goldfields, on which Coase based his claims of a deceitful and self-aggrandizing family, did not take place. Alfred did know where he was born and was happy to say so. Alfred’s grandfather, William, was not a forgotten business failure. Alfred’s father, also William, was neither disliked nor ostracized by his family despite being cantankerous and possibly brutal. He and his wife Rebecca and their children, including Alfred, were embraced and supported by the wider family. Alfred was, in fact, a product of the family much as described by his wife, Mary Paley Marshall, and John Maynard Keynes. This does not diminish his accomplishments.
Transgressing Che
Authors: Franco Robert
Published: February 2020

This article uses the life of Irina Layevska Echeverría Gaitán, a transgender and disability rights activist from Mexico, as a lens to examine the circulation and appropriation of the discursive New Man and the figure of Che Guevara by a broad set of actors from leftist revolutionaries to sexual rights activists in Mexico. Grappling with questions of temporality and intersectionality throughout, it follows her struggles to amend revolutionary discourses with her personal life despite her exclusion from normative models of the revolutionary figure. It argues that those excluded from the heteronormative able-bodied ideal of militancy—gay men, women, trans folk and those with disabilities—used the futurist, universal, and self-developmental aspects of the New Man to reject exclusionary leftist politics. Furthermore, the New Man as an aspirational yet abstract goal enabled the formulation of radically transgressive subject positions and provided a discourse with which to construct a militant identity that was inclusive and oppositional to the masculinist and ableist revolution.
Between Politics and Desire
Authors: Halperin Paula
Published: February 2020

In 1994, Tomás Gutiérrez Alea’s Fresa y Chocolate (1993) swept the awards at Brazil’s Gramado Film Festival. Founded in 1973, the festival was not only a platform for art-house films; Gramado had functioned as a space of creative freedom and resistance to censorship during the worst years of Brazil’s military regime (1964–85). Fresa y Chocolate was highly anticipated; it foregrounded a cluster of sensitive issues such as homosexuality, freedom of speech, and censorship, in a Cuba immersed in the so-called Special Period. This article examines the debates provoked by Fresa in Brazil, which had recently emerged from a long authoritarian regime and was confronting the implementation of neoliberal policies. Through Alea’s film, Brazilian critics and journalists discussed the themes advanced by “the Cuban case,” which struck a chord and ignited debate with the local public.
Women, Gender, and Sexuality in the Cuban Revolution
Authors: Hutchison Elizabeth Quay
Published: February 2020

In a summer 2018 interview conducted for this special issue of RHR, the US-born lesbian feminist artist, activist, and scholar Margaret Randall reflects on the Cuban Revolution’s achievements and shortcomings in the arena of women’s and sexuality rights. What have women and sexual minorities contributed to Cuba’s experiment in radical equality, and what remains to be done? How has feminism—in all its variety—shaped the aspirations of Cuban men and women, and what have US feminists learned from their efforts? What makes gender justice happen, and who or what constitutes barriers to change?
“Children of the Revolution”
Authors: Cosse Isabella
Published: February 2020

This interview of Gregory Randall offers a lens onto a transnational life experience, including that of international refugees in Cuba. Randall was born in New York in 1960. He spent his early childhood in Mexico and arrived in Cuba in 1970, where he remained until the 1980s. In this interview, Randall reflects on Cuban policies toward women, homosexuality, and youth. He also analyzes his own family’s experience, characterized by a strong commitment to reflecting the Cuban Revolution in its own social relations and its ways of living and loving. The interview provides a unique perspective on these challenges and on Cuban history, shaped by Randall’s particular position in that historical process. Unmoored from national frameworks, his subjectivity is anchored in a transnational Left sensibility. He belongs to a generation of children of the revolution, part of Socialist Cuba as children and teenagers, and belonging to Left and internationalist families.
A clearer picture of the ER translocon complex
Authors: Gemmer Max , Förster Friedrich
Published: February 2020

The endoplasmic reticulum (ER) translocon complex is the main gate into the secretory pathway, facilitating the translocation of nascent peptides into the ER lumen or their integration into the lipid membrane. Protein biogenesis in the ER involves additional processes, many of them occurring co-translationally while the nascent protein resides at the translocon complex, including recruitment of ER-targeted ribosome–nascent-chain complexes, glycosylation, signal peptide cleavage, membrane protein topogenesis and folding. To perform such varied functions on a broad range of substrates, the ER translocon complex has different accessory components that associate with it either stably or transiently. Here, we review recent structural and functional insights into this dynamically constituted central hub in the ER and its components. Recent cryo-electron microscopy (EM) studies have dissected the molecular organization of the co-translational ER translocon complex, comprising the Sec61 protein-conducting channel, the translocon-associated protein complex and the oligosaccharyl transferase complex. Complemented by structural characterization of the post-translational import machinery, key molecular principles emerge that distinguish co- and post-translational protein import and biogenesis. Further cryo-EM structures promise to expand our mechanistic understanding of the various biochemical functions involving protein biogenesis and quality control in the ER.
Development and application of artificial intelligence in cardiac imaging
Authors: Jiang Beibei , Guo Ning , Ge Yinghui , Zhang Lu , Oudkerk Matthijs , Xie Xueqian
Published: February 2020

In this review, we describe the technical aspects of artificial intelligence (AI) in cardiac imaging, starting with radiomics, basic algorithms of deep learning and application tasks of algorithms, until recently the availability of the public database. Subsequently, we conducted a systematic literature search for recently published clinically relevant studies on AI in cardiac imaging. As a result, 24 and 14 studies using CT and MRI, respectively, were included and summarized. From these studies, it can be concluded that AI is widely applied in cardiac applications in the clinic, including coronary calcium scoring, coronary CT angiography, fractional flow reserve CT, plaque analysis, left ventricular myocardium analysis, diagnosis of myocardial infarction, prognosis of coronary artery disease, assessment of cardiac function, and diagnosis and prognosis of cardiomyopathy. These advancements show that AI has a promising prospect in cardiac imaging.
Time lag between the tropopause height and the levels of 7Be concentrations in surface air
Authors: Ioannidou E. , Leppänen A.-P. , Melas D. , Ioannidou A.
Published: February 2020

The concentration of 7Be at near surface air has been determined over 2009, which was a year of a deep solar minimum, at three different locations in Finland: Ivalo (68°64’N, 27°57’E), Rovaniemi (66°51’N, 25°68’E) and Kotka (60°48’N, 26°92’E). In geomagnetic latitudes over λ = 60° N, the elevation of tropopause during the warm summer months and the vertical exchange of air masses within the troposphere cause greater mixture of the air masses resulting in higher concentration levels for 7Be in surface air. However, different climatic phenomena, such as air masses from the East, make the correlation between the monthly activity concentrations of 7Be and the tropopause height fairly weak. For Ivalo and Rovaniemi it was found that changes in the daily surface concentrations of 7Be lag the changes in the elevation of the tropopause by four days. In Kotka, the correlation is weakest.
Average cross section measurement for 162Er(γ,n) reaction compared with theoretical calculations using TALYS
Authors: Vagena E. , Stoulos S.
Published: February 2020

Bremsstrahlung photon beam delivered by a linear electron accelerator has been used to experimentally determine the near threshold photonuclear cross section data of nuclides. For the first time, (γ,n) cross section data was obtained for the astrophysical important nucleus 162Er. Moreover, theoretical calculations have been applied using the TALYS 1.6 code. The effect of the gamma ray strength function on the cross section calculations has been studied. A satisfactorily reproduction of the available experimental data of photonuclear cross section at the energy region below 20 MeV could be achieved. The photon flux was monitored by measuring the photons yield from seven well known (γ, n) reactions from the threshold energy of each reaction up to the end-point energy of the photon beam used. An integrated cross-section 87 ± 14 mb is calculated for the photonuclear reaction 162Er(γ,n) at the energy 9.2 - 14 MeV. The effective cross section estimated using the TALYS code range between 89 and 96 mb depending on the γ-strength function used. The result for 162Er(γ,n), is found to be in good agreement with the theoretical values obtained by TALYS 1.6. So, the present indirect process could be a valuable tool to estimate the effective cross section of (γ,n) reaction for various isotopes using bremsstrahlung beams.
Installation of NEOPTOLEMOS, the new sum spectrometer for cross section measurements of capture reactions at the ΤANDEM Accelerator Laboratory of NCSR “Demokritos”
Authors: Lagaki V. , Michalopoulou-Petropoulou V. , Axiotis M. , Foteinou V. , Lagoyannis A. , Provatas G. , Harrisopulos S.
Published: February 2020

Cross-section measurements of capture reactions are of key importance in understanding the contribution of the uncertainties of nuclear properties, such as the nucleon-nucleus potential and the nuclear level densities, entering in astrophysics abundance calculations. During the recent years, the Nuclear Astrophysics group of NCSR “Demokritos” has been conducting angle-integrated cross-section measurements using a large-volume NaI(Tl) detector installed at the Dynamitron Tandem Laboratory of the University of Bochum in Germany. Thanks to LIBRA funds a brand new cylindrically shaped NaI(Tl) detector, coined NEOPTOLEMOS, was acquired that is axially segmented in two, covering a solid angle of almost 4π for γ rays emitted at its center.
Radiological impact assessment in the terrestrial environment of Greece using innovative tools – Adaptation of ERICA Tool to actual measurements
Authors: Sotiropoulou M. , Florou H. , Kitis G.
Published: February 2020

In the present study, the radioactivity levels in terrestrial non-human biota and the transfer pathways in the ecosystem are examined. Grass of Poaceae family and herbivore mammals (ruminants) of Bovidae family and soil samples were collected during the period of 2010 to 2014, from grasslands of the Greek rural territory where sheep and goats were free-range grazing. Natural background radionuclides (226Ra, 228Ra, 228Th) and artificial radionuclides (137Cs, 134Cs, 131I) were detected in the collected samples using gamma spectrometry. The actual measured activity concentrations and site- specific data of the studied organisms were imported in ERICA Assessment Tool (Version 1.2.1, February 2016) in order to provide an insight of the radiological dose rates. Natural radionuclides exhibited significantly higher contribution to the total dose rate than the artificial ones. The radiological exposure to Fukushima-derived radionuclides was quite low and owed to internal exposure, mainly derived through the ingestion pathway. According to the screening levels, the calculated dose rate to the studied non-human biota was below the threshold levels. However, the obtained results may be proved useful in further research regarding the possible impact of protracted low level ionising radiation to non-human biota on the various levels of life’s organization.
Design and operation of a therapeutic unit with unsealed radioactive sources
Authors: Papadopoulos A. , Dristiliaris D. , Tsiouris S. , Fotopoulos A. , Kalef-Ezra J.
Published: February 2020

A radioisotope therapeutic unit (RTU) for the treatment of patients with radiopharmaceuticals was designed and set in operation by the Ioannina University Hospital Medical Physics and Nuclear Medicine Departments. A number of parameters and procedures have been taken into account during the design stage to combine high quality medical services with minimum unjustified radiation exposures. Two pre-existing wards were modified to therapy / isolation wards by the addition of structural shielding made of concrete or/and iron and lead plates. Similar modifications were carried out in some of the remaining rooms of the RTU, such as the corresponding hot-lab and the storage-to-decay rooms. A network of GM detectors was installed for continuous monitoring of radiation levels at various locations. Among the first one hundred patients treated at the Unit, 80 had differentiated cancer and 14 had hyperthyroidism and were treated with 131I of activity ranging between 0.74 and 7.4 GBq. The maximum H*(10) rate at 1.0 m distance from the patient’s body was one of the criteria for patient release and was set on patient-specific terms. The adequacy of the RTU design and the employed operational policies were verified in practice. In conclusion, the RTU meets successfully the predicted needs.
Investigation of tungsten-coated divertor tiles at the JET tokamak with the ITER‐Like Wall
Authors: Tsavalas P. , Lagoyannis A. , Mergia K. , Provatas G. , Triantou K. , Tsompopoulou E. , Harissopulos S. , Petersson P. , Rubel M. , Mertzimekis T. J. , JET Contributors And the
Published: February 2020

Materials migration in fusion plasma devices and fuel retention in plasma-facing components are issues of great importance for the safe operation of fusion devices. The underlying mechanisms require a good understanding in order to make predictions regarding the lifetime of wall components and to assess the amount of fuel retained in the machine mainly in co-deposited layers. To reduce fuel inventory and to investigate plasma-wall interactions a large-scale experiment at the JET (Joint European Torus) tokamak is realized: operation with the ITER-Like Wall (JET-ILW) which comprises beryllium and tungsten. The current work reports on the post-mortem analysis of W/CFC tiles retrieved after the first deuterium-deuterium campaign at JET-ILW. Specimens from different areas of the divertor have been analyzed by means of several techniques including nuclear reaction analysis and Rutherford backscattering employing a deuterium beam. In addition, X-ray fluorescence spectroscopy and scanning electron microscopy with energy dispersive X-ray analysis are used to assess the sample surface morphology and analyze the stoichiometry of the surface of the samples in order to compare with the results from the ion beam analytical techniques.
Neutron capture data for unstable nuclei – Astrophysical quests and experimental challenges
Authors: Käppeler F.
Published: February 2020

The abundances of the chemical elements heavier than iron can be attributed in about equal parts to the r and s processes, which are taking place in supernova explosions and during the He and C burning phases of stellar evolution, respectively. So far, quantitative studies of the r-process are out of reach, because it involves reactions on extremely short-lived neutron-rich nuclei. On the contrary, the situation for the s-process is far advanced, thanks to a comprehensive database of experimental (n,γ) cross sections for most isotopes along the reaction path from 12C to the Pb/Bi region. For the stable isotopes last gaps in the data are presently closed, but further studies are clearly needed to reach the required accuracy and to resolve remaining discrepancies. The quest for cross sections of unstable isotopes remains a persisting challenge though. In particular, nuclei which act as branching points are of prime interest, because they provide key information on the deep stellar interior. While the activation method is limited to a few exceptional branch-point nuclei, successful measurements via the time-of- flight technique are depending on intense pulsed neutron sources and elaborate methods for sample production. Current developments in Europe are providing promising perspectives in both areas.
A Preliminary Study of Mosses as Biomonitors of 137Cs Activity in the Air of Ioannina City
Authors: Stamoulis K. , Alexandropoulou M. , Petsios S , Papachristodoulou C. A. , Papadopoulou C. , Ioannides K. G.
Published: February 2020

Mosses were collected during the winter months of 2014 and 2015 from various locations in the center and outskirts of the city of Ioannina, to serve as biomonitors of 137Cs activity released from the combustion of biomass fuel in the atmospheric air. Statistical analysis of the obtained activity concentrations revealed differences between sampling locations and sampling periods, which may be attributed to different practices in the use of wood and wood by-products fuel for household heating.
Measurement of radionuclides and trace metals concentration in surface sediments from the coastal zone of Lavreotiki peninsula
Authors: Michalopoulou-Petropoulou V. , Tsabaris C. , Patiris D. L. , Androulakaki E. G. , Eleftheriou G. , Kokkoris M. , Pappa F. K. , Vlastou R.
Published: February 2020

This work presents the results of a preliminary study at the coastal zone of the Lavreotiki peninsula, concerning radionuclide and trace metal concentration measurements in sediment samples collected from the seabed of four local gulfs and the corresponding beaches. The radionuclide activity concentrations were determined by means of gamma-ray spectroscopy and the concentration of trace metals by the XRF method. The observed radionuclide levels of both seabed and beach sediment are considered relatively low to medium, in comparison with international values of activity concentration in soil. For most of the trace metals, high concentrations were measured in comparison with guidelines, especially for As, Mn, Pb and Zn.
Dose Distribution near Tissue In-homogeneities in Megavoltage Radiation Therapy
Authors: Katsarou E. , Karava K. , Stamatelatos I. E. , Kalef-Ezra J.
Published: February 2020

The presence of an in-homogeneity inside the human body modifies the radiation dose distribution in tissue. Such disturbances are even higher close to the interface between materials of different atomic number, Z. During radiotherapy with megavolt photons a remarkable lack of particle equilibrium is displayed in the transition zones between soft tissues and either bones or devices implanted in the human body for medical purposes, resulting in large dose gradients.The disturbance in the dose distribution in soft tissue close to a high Z material in regions where the photon beam enters or exits the in-homogeneity, is quantified by the Backscatter Dose Factor (BSDF) and Forward Scatter Dose Factor (FSDF), respectively. In the present work BSDF and FSDF dependence on photon energy, material thickness, atomic number and field size were studied experimentally. For this purpose, slabs made of high Z material (aluminum, copper and lead) were inserted in a PMMA (Plexiglas) phantom. Irradiations were performed using a Co-60 teletherapy unit and two 6 MV linear accelerators. Dose measurements were carried out using MD-55 and HD-810 Gafchromic films.The results of the study showed that the presence of the in-homogeneity increased the absorbed dose in the low Z material before the in-homogeneity (BSDF >1.00) and decreased after it (FSDF <1.00). Moreover, it was found that BSDF increases as the in-homogeneity thickness increases (up to a saturation thickness). On the contrary, FSDF decreases with increasing in-homogeneity thickness. In addition, both disturbances increase with increasing Z of the in-homogeneity. Outcome of this study was high quality experimental data to be used for benchmarking BSDF and FSDF calculations performed by dedicated Monte Carlo and analytical radiotherapy treatment planning systems.
R-mode constraints from neutron star equation of state
Authors: Moustakidis Ch. C. , Papazoglou M. C.
Published: February 2020

The gravitational radiation has been proposed a long time before, as an explana- tion for the observed relatively low spin frequencies of young neutron stars and of accreting neutron stars in low-mass X-ray binaries as well. In the present work we studied the effects of the neutron star equation of state on the r-mode instability window of rotating neutron stars.
The role of magnetic fields in the formation and propagation of hadronic microquasars jets
Authors: Paspaliaris E.-D. S. , Smponias T. , Kosmas T. S.
Published: February 2020

In the present work, we examine the role of the magnetic field (MF), which causes a rather pronounced confinement of the jets at microquasars. Due to radial Lorentz forces acting on the jet’s matter towards the jet’s axis, the outgoing flux is collimated along the same axis and vertically to the compact object. Alternatively, a rotating central object may drag the surrounding MF into collimation around the produced jet. In such objects, jet emerges from each side of the accretion disc.These jets operate as cosmic engines, capable of accelerating particles on very high energies (~10^2 TeV) and consist sources of high energy neutrinos and gamma rays. We also examine the role of the MF, which causes to a rather pronounced jet confinement. Our aim is to investigate and model its role on various physical observables of the jet, by simulating the jet’s flow and derive 2D and 3D visualizations and furthermore examine its effect on the neutrino emissivity.
Large Sample Neutron Activation Analysis of Ceramic Matrix Composites
Authors: Stamatelatos I. E. , Vasilopoulou T. , Tsompopoulou E. , Blaauw M. , Mergia K.
Published: February 2020

Carbon fiber reinforced SiC ceramic matrix composites (Cf/SiC) are promising structural materials for a variety of high-temperature aerospace and energy applications. Since the matrix elements are carbon and silicon, they present low activation after neutron irradiation and therefore are materials of particular interest for fusion energy technology applications. Large Sample Neutron Activation Analysis (LSNAA) was applied to determine the elemental composition of Cf/SiC specimens joined together using a high temperature graphite based adhesive. The neutron irradiations and gamma ray measurements were performed at the BISNIS facility of the Hoger Onderwijs Reactor, TU Delft. The results of this study demonstrate the feasibility of application of LSNAA as a cost-effective method for non-destructive elemental composition analysis of whole ceramic specimens enabling the calculation of induced activity and dose rate after irradiation in different neutron spectra.
Measurement of the 237Np(n,f) cross section with the FIC detector at the CERN n_TOF facility
Authors: Diakaki M. , For the nTOF Collaboration Et al.
Published: February 2020

The cross section of the 237Np(n,f) reaction has been experimentally determined at the n_TOF facility at CERN, in the neutron energy range 100 keV – 10 MeV, relative to the standard 235U(n,f) and 238U(n,f) reaction cross sections with use of a Fast Ionisation Chamber. The reproduction of the high accuracy data obtained from this experiment was attempted within the Hauser-Feshbach formalism and phenomenological models with use of the code EMPIRE 3.2.
Neutron reaction studies in the rare earth region: First results for the 162Er(n,2n)161Er physics case
Authors: Patronis N. , Aslanoglou X. , Axiotis M. , Eleme Z. , Foteinou V. , Harissopulos S. , Kalamara A. , Kokkoris M. , Provatas G. , Vlastou R.
Published: February 2020

In the present work the first experimental results at near two threshold energies for the 162Er(n,2n)161Er reaction study are presented. The reaction cross section was determined at the energies of 11.0 and 11.3 MeV by means of the activation technique. The experimental method and setup is described.
Activation cross section for the (n,2n) reaction on 197Au
Authors: Kalamara A. , Serris M. , Anastasiou M. , Diakaki M. , Kokkoris M. , Patronis N. , Paneta V. , Axiotis M. , Lagoyannis A. , Vlastou R.
Published: February 2020

The cross section of the reaction channels 197Au(n,2n)196Aug+m1 and 197Au(n,2n)196Aum2 has been experimentally determined at 15.3 MeV, relative to the 27Al(n,α)24Na reference reaction, using the activation technique. The irradiation was carried out at the 5 MV tandem T11/25 Accelerator Laboratory of NCSR "Demokritos" with monoenergetic neutron beam provided by means of the 3H(d,n)4He reaction, using a new Ti-tritiated target of 373 GBq activity. The induced γ- ray activity was measured with a high resolution HPGe detector.
Microscopic Calculations of Low and Medium Energy Fission with the CoMD (Constrained Molecular Dynamics) Model
Authors: Vonta N. , Souliotis G. A. , Bonasera A. , Veselsky M.
Published: February 2020

The investigation of the mechanism of nuclear fission is a topic of current experimental and theoretical interest. In this work, we initiated a systematic study of low and intermediate energy fission calculations using the Constrained Molecular Dynami cs (CoMD) code. The code implements an effective interaction with a soft isoscalar part and with several forms of the density dependence of the nucleon symmetry potential. In addition, CoMD imposes a constraint in the phase space occupation for each nucleon restoring the Pauli principle at each time step of the evolution of the nuclear system. Proper choice of the surface parameter of the effective interaction has been made to describe fission. In this work, we present CoMD calculations for several proton- included fission reactions at low and intermediate energy and compare them with recent experimental data. We found that the CoMD code is able to describe the complicated many-body dynamics of the fission process especially for intermediate and higher-energy fission reactions. Proper adjustment of the parameters of the effective interaction and further improvements of the code are necessary to achieve a satisfactory quantitative description of low-energy fission where shell effects play a definitive role.
The role of e- capture in neutrino-nucleosynthesis
Authors: Giannaka P. G. , Kosmas T. S.
Published: February 2020

In the first stage of this paper, we perform detailed calculations of the electron capture cross sections on nuclei under laboratory conditions. We use the nuclear method known as proton-neutron quasi-particle random phase approximation (pn-QRPA). In the second stage, we translate the above mentioned e--capture cross sections to the stellar environment. As a concrete nuclear target we use the 56Fe and the 66Zn isotopes, which belong to the iron group nuclei and play prominent role in stellar nucleosynthesis: i) in pre-supernova phase and ii) in supernova phase.
Use of the Optically Stimulated Luminescence Dating and X-Ray Fluorescence Spectrometry Methods as Tools in Paleoseismology
Authors: Tsodoulos L. M. , Stamoulis K. , Papachristodoulou C. A. , Ioannides K. G. , Pavlides S.
Published: February 2020

We have investigated the application of luminescence dating to sediment and pottery samples from a paleoseismological trench excavated in the Gyrtoni Fault, Tyrnavos Basin, Central Greece. The samples were dated following the optically stimulated luminescence (OSL) dating method, using the Riso TL/OSL DA-20 reader. The OSL ages were obtained from chemically purified quartz and a single-aliquot regenerative-dose (SAR) protocol was followed for the equivalent dose (De) determination. Additionally, samples were collected and analyzed with the method of X-ray Fluorescence (XRF) spectrometry, in order to assess their elemental composition. Radioisotope sources (109Cd and 241Am) were used for sample excitation, while X-ray spectra were acquired using a Si(Li) detector coupled with standard electronics. The XRF data were submitted to principal component analysis (PCA). This statistical handling aimed to distinguish from which part of the upthrown fault block scarp-derived colluvium and alluvial deposits, parts of the downthrown block were derived and thus estimate the displacement. The results indicated that both the OSL dating method and the XRF analysis combined with PCA can serve as useful tools for paleoseismological investigations.
Use of everyday materials in retrospective nuclear accident dosimetry
Authors: Stamoulis K. , Ioannides K. G. , Bakola H. , Papachristodoulou C. A. , Tsodoulos L. M.
Published: February 2020

Following a large-scale nuclear event, a quantitative estimate of the radiation dose to the general population necessitates the availability of adequate procedures for the assessment of doses. The main objectives of dose reconstruction, namely retrospective dosimetry can be synoptically stated as in the following: a) To guide the provision of proper protection for the population that had been exposed to radiation, b) To provide assuring information to the worrying public and c) To provide input data for epidemiological studies. Amongst the methods used for dose estimation are the Thermoluminescence (TL) and the Optically Stimulated Luminescence (OSL). Methods based on TL and OSL have the advantage that they allow the measurement of the integrated absorbed dose. When the irradiation comes from external sources, materials found within the perimeter of the accident area such as bricks, tiles and pottery and certain household chemicals, can be used. The absorbed dose may be evaluated many years after the accident.
Large Sample Neutron Activation Analysis of a Peruvian Pottery Artifact
Authors: Vasilopoulou T. , Stamatelatos I. E. , Montoya E. , Bedregal P. , Tsalafoutas I. , Bode P.
Published: February 2020

The present work was carried out within the first Large Sample Neutron Activation Analysis (LSNAA) intercomparison study organized under the auspices of the International Atomic Energy Agency (IAEA). Replicates of a Peruvian pottery object, representing a Pre-Columbian archaeological artifact, were prepared by the Instituto Peruano de Energia Nuclear (IPEN) and distributed to 10 laboratories with LSNAA capa- bilities. The LSNAA results were compared against values derived by conventional Instrumental Neutron Activation Analysis (INAA) on small amounts of the material used to produce the test object. The results of the intercomparison study will be presented in detail in a separate publication. In this work, the LSNAA methodology developed at ’Demokritos’ for analysis of large and irregular shaped objects is discussed. An accurate description of the complex geometry of the object was obtained by Computerized Tomography X-ray scanning. The correction factors required for the effects of neutron self-shielding and gamma-ray self-attenuation within the large sample material were derived by Monte Carlo simulations using MCNP code. The results of the study showed that LSNAA provides elemental concentration values with a satisfactory agreement against values obtained by conventional INAA. Therefore, LSNAA is a technique suitable for the purpose of analysis of intact pottery objects of irregular shape for archaeological studies.