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| 2. |
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| 3. |
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| 4. |
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| 5. |
- Dixon, P., et al.
(författare)
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Nitrogen-Hydrogen Defects in GaP
- 1998
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Ingår i: Physica status solidi. B, Basic research. - 0370-1972 .- 1521-3951. ; 210:2, s. 321-326
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Tidskriftsartikel (refereegranskat)abstract
- Models of the nitrogen-hydrogen defect in GaP, which contain one and two H atoms, are investigated using ab initio density functional cluster theory. We find that a single H atom binding to N possesses two infrared absorption frequencies close to those attributed to an NH2 defect. The modes shift with its charge state consistent with the photo-sensitivity found for the defect. A third mode observed for this centre is assumed to be an overtone of the bend mode. The isotope shifts of the calculated modes are in excellent agreement with experiment in contrast with the model which contains two H atoms.
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| 6. |
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| 7. |
- Miller, D. J., et al.
(författare)
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Oxidation of Pt(111) under Near-Ambient Conditions
- 2011
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 107:19, s. 195502-
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Tidskriftsartikel (refereegranskat)abstract
- The oxidation of Pt(111) at near-ambient O(2) pressures has been followed in situ using x-ray photoelectron spectroscopy (XPS) and ex situ using x-ray absorption spectroscopy (XAS). Polarization-dependent XAS signatures at the O K edge reveal significant temperature-and pressure-dependent changes of the Pt-O interaction. Oxide growth commences via a PtO-like surface oxide that coexists with chemisorbed oxygen, while an ultrathin alpha-PtO(2) trilayer is identified as the precursor to bulk oxidation. These results have important implications for understanding the chemical state of Pt in catalysis.
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| 8. |
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| 9. |
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| 10. |
- Pavel, M. E., et al.
(författare)
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Efficacy of everolimus plus octreotide LAR in patients with advanced neuroendocrine tumor and carcinoid syndrome : final overall survival from the randomized, placebo-controlled phase 3 RADIANT-2 study
- 2017
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Ingår i: Annals of Oncology. - : OXFORD UNIV PRESS. - 0923-7534 .- 1569-8041. ; 28:7, s. 1569-1575
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Tidskriftsartikel (refereegranskat)abstract
- Background: In the phase 3 RADIANT-2 study, everolimus plus octreotide long-acting repeatable (LAR) showed improvement of 5.1 months in median progression-free survival versus placebo plus octreotide LAR among patients with advanced neuroendocrine tumors associated with carcinoid syndrome. The progression-free survival P-value was marginally above the pre-specified threshold for statistical significance. Here, we report final overall survival (OS) and key safety update from RADIANT-2.Patients and methods: The RADIANT-2 trial compared everolimus (10 mg/day, orally; n = 216) versus placebo (n = 213), both in conjunction with octreotide LAR (30 mg, intramuscularly, every 28 days). Patients, unblinded at the time of progression or after end of double-blind core phase following primary analysis, were offered open-label everolimus with octreotide LAR (open-label phase). In the open-label phase, patients had similar safety and efficacy assessments as those in the core phase. For OS, hazard ratios (HRs) with 95% CIs using unadjusted Cox model and a Cox model adjusted for prespecified baseline covariates were calculated.Results: A total of 170 patients received open-label everolimus (143 crossed over from the placebo arm; 27 in the everolimus arm continued to receive the same treatment after unblinding). The median OS (95% CI) after 271 events was 29.2 months (23.8-35.9) for the everolimus arm and 35.2 months (30.0-44.7) for the placebo arm (HR, 1.17; 95% CI, 0.92-1.49). HR adjusted for baseline covariates was 1.08 (95% CI, 0.84-1.38). The most frequent drug-related grade 3 or 4 AEs reported during the open-label phase were diarrhea (5.3%), fatigue (4.7%), and stomatitis (4.1%). Deaths related to pulmonary or cardiac failure were observed more frequently in the everolimus arm.Conclusion: No significant difference in OS was observed for the everolimus plus octreotide LAR and placebo plus octreotide LAR arms of the RADIANT-2 study, even after adjusting for imbalances in the baseline covariates. Clinical Trial Number: NCT00412061, www.clinicaltrials.gov
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| 11. |
- Pavel, M., et al.
(författare)
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ENETS Consensus Guidelines Update for the Management of Distant Metastatic Disease of Intestinal, Pancreatic, Bronchial Neuroendocrine Neoplasms (NEN) and NEN of Unknown Primary Site
- 2016
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Ingår i: Neuroendocrinology. - : S. Karger AG. - 0028-3835 .- 1423-0194. ; 103:2, s. 172-185
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Tidskriftsartikel (refereegranskat)abstract
- The goal of this paper is to update a more extensive review and guidelines paper published in 2012 [1] . Gen-erally, any pertinent update pertaining to the diagnosis and staging of individual primary tumors is provided in the relevant papers published elsewhere in this issue of updated guideline reviews. More specific issues with re-spect to therapy of stage IV neuroendocrine neoplasms (NEN) (focusing on grade1/2 tumors) are given below. A separate guideline is provided for poorly differentiated neoplasms (grade 3 NEN). As some new large phase III trials have been published since the previous guidelines, this has indeed led to specific modifications in our ap-proach to therapy.
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| 12. |
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| 13. |
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| 14. |
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| 15. |
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| 16. |
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| 17. |
- Strosberg, J., et al.
(författare)
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Phase 3 Trial of Lu-177-Dotatate for Midgut Neuroendocrine Tumors
- 2017
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Ingår i: New England Journal of Medicine. - 0028-4793 .- 1533-4406. ; 376:2, s. 125-135
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND Patients with advanced midgut neuroendocrine tumors who have had disease progression during first-line somatostatin analogue therapy have limited therapeutic options. This randomized, controlled trial evaluated the efficacy and safety of lutetium-177 (Lu-177)-Dotatate in patients with advanced, progressive, somatostatin-receptor-positive midgut neuroendocrine tumors. METHODS We randomly assigned 229 patients who had well-differentiated, metastatic midgut neuroendocrine tumors to receive either Lu-177-Dotatate (116 patients) at a dose of 7.4 GBq every 8 weeks (four intravenous infusions, plus best supportive care including octreotide long-acting repeatable [LAR] administered intramuscularly at a dose of 30 mg) (Lu-177-Dotatate group) or octreotide LAR alone (113 patients) administered intramuscularly at a dose of 60 mg every 4 weeks (control group). The primary end point was progression-free survival. Secondary end points included the objective response rate, overall survival, safety, and the side-effect profile. The final analysis of overall survival will be conducted in the future as specified in the protocol; a prespecified interim analysis of overall survival was conducted and is reported here. RESULTS At the data-cutoff date for the primary analysis, the estimated rate of progression-free survival at month 20 was 65.2% (95% confidence interval [CI], 50.0 to 76.8) in the Lu-177-Dotatate group and 10.8% (95% CI, 3.5 to 23.0) in the control group. The response rate was 18% in the Lu-177-Dotatate group versus 3% in the control group (P<0.001). In the planned interim analysis of overall survival, 14 deaths occurred in the Lu-177-Dotatate group and 26 in the control group (P = 0.004). Grade 3 or 4 neutropenia, thrombocytopenia, and lymphopenia occurred in 1%, 2%, and 9%, respectively, of patients in the Lu-177-Dotatate group as compared with no patients in the control group, with no evidence of renal toxic effects during the observed time frame. CONCLUSIONS Treatment with Lu-177-Dotatate resulted in markedly longer progression-free survival and a significantly higher response rate than high-dose octreotide LAR among patients with advanced midgut neuroendocrine tumors. Preliminary evidence of an overall survival benefit was seen in an interim analysis; confirmation will be required in the planned final analysis. Clinically significant myelosuppression occurred in less than 10% of patients in the Lu-177-Dotatate group. (Funded by Advanced Accelerator Applications; NETTER-1 ClinicalTrials. gov number, NCT01578239; EudraCT number 2011-005049-11.)
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| 18. |
- Östrom, Henrik, et al.
(författare)
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Probing the transition state region in catalytic CO oxidation on Ru
- 2015
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 347:6225, s. 978-982
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Tidskriftsartikel (refereegranskat)abstract
- Femtosecond x-ray laser pulses are used to probe the carbon monoxide (CO) oxidation reaction on ruthenium (Ru) initiated by an optical laser pulse. On a time scale of a few hundred femtoseconds, the optical laser pulse excites motions of CO and oxygen (O) on the surface, allowing the reactants to collide, and, with a transient close to a picosecond (ps), new electronic states appear in the OK-edge x-ray absorption spectrum. Density functional theory calculations indicate that these result from changes in the adsorption site and bond formation between CO and O with a distribution of OC-O bond lengths close to the transition state (TS). After 1 ps, 10% of the CO populate the TS region, which is consistent with predictions based on a quantum oscillator model.
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| 19. |
- Adey, J., et al.
(författare)
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Degradation of boron-doped Czochralski-grown silicon solar cells
- 2004
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 93:5, s. 055504-1
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Tidskriftsartikel (refereegranskat)abstract
- The formation mechanism and properties of the boron-oxygen center responsible for the degradation of Czochralski-grown Si(B) solar cells during operation is investigated using density functional calculations. We find that boron traps an oxygen dimer to form a bistable defect with a donor level in the upper half of the band gap. The activation energy for its dissociation is found to be 1.2 eV. The formation of the defect from mobile oxygen dimers, which are shown to migrate by a Bourgoin mechanism under minority carrier injection, has a calculated activation energy of 0.3 eV. These energies and the dependence of the generation rate of the recombination center on boron concentration are in good agreement with observations.
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| 20. |
- Adey, J., et al.
(författare)
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Theory of boron-vacancy complexes in silicon
- 2005
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 71:16, s. 165211-
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Tidskriftsartikel (refereegranskat)abstract
- The substitutional boron-vacancy BsV complex in silicon is investigated using the local density functional theory. These theoretical results give an explanation of the experimentally reported, well established metastability of the boron-related defect observed in p-type silicon irradiated at low temperature and of the two hole transitions that are observed to be associated with one of the configurations of the metastable defect. BsV is found to have several stable configurations, depending on charge state. In the positive charge state the second nearest neighbor configuration with C1 symmetry is almost degenerate with the second nearest neighbor configuration that has C1h symmetry since the bond reconstruction is weakened by the removal of electrons from the center. A third nearest neighbor configuration of BsV has the lowest energy in the negative charge state. An assignment of the three energy levels associated with BsV is made. The experimentally observed Ev+0.31 eV and Ev+0.37 eV levels are related to the donor levels of second nearest neighbor BsV with C1 and C1h symmetry respectively. The observed Ev+0.11 eV level is assigned to the vertical donor level of the third nearest neighbor configuration. The boron-divacancy complex BsV2 is also studied and is found to be stable with a binding energy between V2 and Bs of around 0.2 eV. Its energy levels lie close to those of the V2. However, the defect is likely to be an important defect only in heavily doped material.
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| 21. |
- Agirre, J. A., et al.
(författare)
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The VALU3S ECSEL project : Verification and validation of automated systems safety and security
- 2021
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Ingår i: Microprocessors and microsystems. - : Elsevier BV. - 0141-9331 .- 1872-9436. ; 87, s. 104349-
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Tidskriftsartikel (refereegranskat)abstract
- Manufacturers of automated systems and their components have been allocating an enormous amount of time and effort in R&D activities, which led to the availability of prototypes demonstrating new capabilities as well as the introduction of such systems to the market within different domains. Manufacturers need to make sure that the systems function in the intended way and according to specifications. This is not a trivial task as system complexity rises dramatically the more integrated and interconnected these systems become with the addition of automated functionality and features to them. This effort translates into an overhead on the V&V (verification and validation) process making it time-consuming and costly. In this paper, we present VALU3S, an ECSEL JU (joint undertaking) project that aims to evaluate the state-of-the-art V&V methods and tools, and design a multi-domain framework to create a clear structure around the components and elements needed to conduct the V&V process. The main expected benefit of the framework is to reduce time and cost needed to verify and validate automated systems with respect to safety, cyber-security, and privacy requirements. This is done through identification and classification of evaluation methods, tools, environments and concepts for V&V of automated systems with respect to the mentioned requirements. VALU3S will provide guidelines to the V&V community including engineers and researchers on how the V&V of automated systems could be improved considering the cost, time and effort of conducting V&V processes. To this end, VALU3S brings together a consortium with partners from 10 different countries, amounting to a mix of 25 industrial partners, 6 leading research institutes, and 10 universities to reach the project goal.
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| 22. |
- Ahlström, Håkan, et al.
(författare)
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Preoperative localization of endocrine pancreatic tumours by intra-arterial dynamic computed tomography
- 1990
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Ingår i: Acta Radiologica. - 0284-1851 .- 1600-0455. ; 31:2, s. 171-175
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Tidskriftsartikel (refereegranskat)abstract
- Eleven patients with biochemically confirmed endocrine pancreatic tumours were examined with intra-arterial (i.a.) dynamic computed tomography (CT) and angiography preoperatively. Seven of the patients suffered from the multiple endocrine neoplasia type 1 (MEN-1) syndrome. All patients were operated upon and surgical palpation and ultrasound were the peroperative localization methods. Of the 33 tumours which were found at histopathologic analysis of the resected specimens in the 11 patients, 7 tumours in 7 patients were correctly localized by both i.a. dynamic CT and angiography. Six patients with MEN-1 syndrome had multiple tumours and this group of patients together had 28 tumours, of which 5 (18%) were localized preoperatively by both CT and angiography. I.a. dynamic CT, with the technique used by us, does not seem to improve the localization of endocrine pancreatic tumours, especially in the rare group of MEN-1 patients, as compared with angiography.
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| 23. |
- Anthony, Lowell B., et al.
(författare)
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Impact of Previous Somatostatin Analogue Use on the Activity of Everolimus in Patients with Advanced Neuroendocrine Tumors : Analysis from the Phase III RADIANT-2 Trial
- 2015
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Ingår i: Neuroendocrinology. - : S. Karger AG. - 0028-3835 .- 1423-0194. ; 102:1-2, s. 18-25
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Tidskriftsartikel (refereegranskat)abstract
- Background/Aims: The phase III placebo-controlled RADI-ANT-2 trial investigated the efficacy of everolimus plus octreotide long-acting repeatable (LAR) in patients with advanced neuroendocrine tumors (NET) associated with carcinoid syndrome. Here we report a secondary analysis based on the previous somatostatin analogue (SSA) exposure status of patients enrolled in RADIANT-2. Methods: Patients were randomly assigned to receive oral everolimus 10 mg/day plus octreotide LAR 30 mg intramuscularly (i.m.) or to receive matching placebo plus octreotide LAR 30 mg i.m. every 28 days. SSA treatment before study enrollment was permitted. Patient characteristics and progression-free survival (PFS) were analyzed by treatment arm and previous SSA exposure status. Results: Of the 429 patients enrolled in RADI-ANT-2, 339 were previously exposed to SSA (95% received octreotide); 173 of 339 patients were in the everolimus plus octreotide LAR arm. All patients had a protocol-specified history of secretory symptoms, but analysis by type showed that more patients who previously received SSA therapy had a history of flushing symptoms (77%), diarrhea (86%), or both (63%) compared with SSA-naive patients (62, 62, and 24%, respectively). Patients who received everolimus plus octreotide LAR had longer median PFS regardless of previous SSA exposure (with: PFS 14.3 months, 95% confidence interval, CI, 12.0-20.1; without: 25.2 months, 95% CI, 12.0-not reached) compared with patients who received placebo plus octreotide LAR (with: 11.1 months, 95% CI, 8.4-14.6; without: 13.6 months, 95% CI, 8.2-22.7). Conclusion: Everolimus in combination with octreotide improves PFS in patients with advanced NET associated with carcinoid syndrome, regardless of previous SSA exposure.
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| 24. |
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| 25. |
- Beye, M., et al.
(författare)
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Selective Ultrafast Probing of Transient Hot Chemisorbed and Precursor States of CO on Ru(0001)
- 2013
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 110:18
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Tidskriftsartikel (refereegranskat)abstract
- We have studied the femtosecond dynamics following optical laser excitation of CO adsorbed on a Ru surface by monitoring changes in the occupied and unoccupied electronic structure using ultrafast soft x-ray absorption and emission. We recently reported [M. Dell'Angela et al. Science 339, 1302 (2013)] a phonon-mediated transition into a weakly adsorbed precursor state occurring on a time scale of >2 ps prior to desorption. Here we focus on processes within the first picosecond after laser excitation and show that the metal-adsorbate coordination is initially increased due to hot-electron-driven vibrational excitations. This process is faster than, but occurs in parallel with, the transition into the precursor state. With resonant x-ray emission spectroscopy, we probe each of these states selectively and determine the respective transient populations depending on optical laser fluence. Ab initio molecular dynamics simulations of CO adsorbed on Ru(0001) were performed at 1500 and 3000 K providing insight into the desorption process.
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| 26. |
- Bhuanantanonoh, K., et al.
(författare)
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MRes Curriculum
- 2005
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Ingår i: 1st Bath University Postgraduate Conference. - Bath : University of Bath.
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Konferensbidrag (refereegranskat)
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| 27. |
- Bissett, I, et al.
(författare)
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Correspondence.
- 2019
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Ingår i: The British journal of surgery. - : Oxford University Press (OUP). - 1365-2168 .- 0007-1323. ; 106:7, s. 952-953
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 28. |
- Caplin, M. E., et al.
(författare)
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Pulmonary neuroendocrine (carcinoid) tumors : European Neuroendocrine Tumor Society expert consensus and recommendations for best practice for typical and atypical pulmonary carcinoids
- 2015
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Ingår i: Annals of Oncology. - : Elsevier BV. - 0923-7534 .- 1569-8041. ; 26:8, s. 1604-1620
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Tidskriftsartikel (refereegranskat)abstract
- Background: Pulmonary carcinoids (PCs) are rare tumors. As there is a paucity of randomized studies, this expert consensus document represents an initiative by the European Neuroendocrine Tumor Society to provide guidance on their management. Patients and methods: Bibliographical searches were carried out in PubMed for the terms 'pulmonary neuroendocrine tumors', 'bronchial neuroendocrine tumors', 'bronchial carcinoid tumors', 'pulmonary carcinoid', 'pulmonary typical/atypical carcinoid', and 'pulmonary carcinoid and diagnosis/treatment/epidemiology/prognosis'. A systematic review of the relevant literature was carried out, followed by expert review. Results: PCs are well-differentiated neuroendocrine tumors and include low-and intermediate-grade malignant tumors, i.e. typical (TC) and atypical carcinoid (AC), respectively. Contrast CT scan is the diagnostic gold standard for PCs, but pathology examination is mandatory for their correct classification. Somatostatin receptor imaging may visualize nearly 80% of the primary tumors and is most sensitive for metastatic disease. Plasma chromogranin A can be increased in PCs. Surgery is the treatment of choice for PCs with the aim of removing the tumor and preserving as much lung tissue as possible. Resection of metastases should be considered whenever possible with curative intent. Somatostatin analogs are the first-line treatment of carcinoid syndrome and may be considered as first-line systemic antiproliferative treatment in unresectable PCs, particularly of low-grade TC and AC. Locoregional or radiotargeted therapies should be considered for metastatic disease. Systemic chemotherapy is used for progressive PCs, although cytotoxic regimens have demonstrated limited effects with etoposide and platinum combination the most commonly used, however, temozolomide has shown most clinical benefit. Conclusions: PCs are complex tumors which require a multidisciplinary approach and long-term follow-up.
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| 29. |
- Carlsson, Susanne, et al.
(författare)
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Affinity of galectin-8 and its carbohydrate recognition domains for ligands in solution and at the cell surface.
- 2007
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 17:6, s. 663-76
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Tidskriftsartikel (refereegranskat)abstract
- Galectin-8 has two different carbohydrate recognition domains (CRDs), the N-terminal Gal-8N and the C-terminal Gal-8C linked by a peptide, and has various effects on cell adhesion and signaling. To understand the mechanism for these effects further, we compared the binding activities of galectin-8 in solution with its binding and activation of cells. We used glycan array analysis to broaden the specificity profile of the two galectin-8 CRDs, as well as intact galectin-8s (short and long linker), confirming the unique preference for sulfated and sialylated glycans of Gal-8N. Using a fluorescence anisotropy assay, we examined the solution affinities for a subset of these glycans, the highest being 50 nM for NeuAcalpha2,3Lac by Gal-8N. Thus, carbohydrate-protein interactions can be of high affinity without requiring multivalency. More importantly, using fluorescence polarization, we also gained information on how the affinity is built by multiple weak interactions between different fragments of the glycan and its carrier molecule and the galectin CRD subsites (A-E). In intact galectin-8 proteins, the two domains act independently of each other in solution, whereas at a surface they act together. Ligands with moderate or weak affinity for the isolated CRDs on the array are bound strongly by intact galectin-8s. Also galectin-8 binding and signaling at cell surfaces can be explained by combined binding of the two CRDs to low or medium affinity ligands, and their highest affinity ligands, such as sialylated galactosides, are not required.
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| 30. |
- Cederqvist, Lars, et al.
(författare)
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Improved process stability during friction stir welding of 5 cm thick copper canisters through shoulder geometry and parameter studies
- 2009
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Ingår i: Science and technology of welding and joining. - London : Institute of Materials. - 1362-1718 .- 1743-2936. ; 14:2, s. 178-184
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Tidskriftsartikel (refereegranskat)abstract
- The spent nuclear fuel from Swedish power plants will be placed in copper canisters that are sealed with friction stir welding and the stability and robustness of this process is now being optimised in three steps: first, the shoulder geometry was identified that produced the most stable weld cycle, then the welding parameters were optimised for that geometry with regards to stability, and finally, the chosen geometry and welding parameters were verified and evaluated during multiple weld cycles. The shoulder study showed that stable welds could be produced repeatedly with a convex scroll geometry which proved more stable than various concave and flat scroll geometries. In the subsequent parameter study, not only were the most stable values for the welding parameters derived, but a clear relationship was shown between power input and tool temperature. This relationship can be used to more accurately control the process within the parameter windows, not only for this application but for other applications where the welding temperature needs to be kept within a specified range. Similarly, the potential of the convex scroll shoulder geometry for use in applications with other metals and thicknesses is evident.
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| 31. |
- Coutens, A., et al.
(författare)
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The ALMA-PILS survey: First detections of deuterated formamide and deuterated isocyanic acid in the interstellar medium
- 2016
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 590
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Tidskriftsartikel (refereegranskat)abstract
- Formamide (NH2CHO) has previously been detected in several star-forming regions and is thought to be a precursor for different prebiotic molecules. Its formation mechanism is still debated, however. Observations of formamide, related species, and their isopotologues may provide useful clues to the chemical pathways leading to their formation. The Protostellar Interferometric Line Survey (PILS) represents an unbiased, high angular resolution and sensitivity spectral survey of the low-mass protostellar binary IRAS 16293-2422 with the Atacama Large Millimeter/submillimeter Array (ALMA). For the first time, we detect the three singly deuterated forms of NH2CHO (NH2CDO, cis-and trans-NHDCHO), as well as DNCO towards the component B of this binary source. The images reveal that the different isotopologues are all present in the same region. Based on observations of the 13C isotopologues of formamide and a standard 12C/13C ratio, the deuterium fractionation is found to be similar for the three different forms with a value of about 2%. The DNCO/HNCO ratio is also comparable to the D/H ratio of formamide (~1%). These results are in agreement with the hypothesis that NH2CHO and HNCO are chemically related through grain-surface formation.
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| 32. |
- Culler, Michael D., et al.
(författare)
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Somatostatin analogs for the treatment of neuroendocrine tumors
- 2011
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Ingår i: Cancer Metastasis Review. - : Springer Science and Business Media LLC. - 0167-7659 .- 1573-7233. ; 30:1, s. 9-17
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Forskningsöversikt (refereegranskat)abstract
- Somatostatin is an important regulator of endocrine and exocrine secretion, affecting the release of many hormones. The effects of somatostatin are mediated through its interaction with one of five somatostatin receptors. Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) express multiple somatostatin receptors, making them excellent potential therapeutic targets. Many trials have shown that treatment with somatostatin analogs is associated with disease stabilization and prolonged survival. More recently, somatostatin analogs have been shown to have antiproliferative effects, thus broadening the scope of their uses. In this review, we update the current data on the treatment of GEP-NETs with somatostatin analogs, with particular emphasis on the results of the PROMID study. In addition, we discuss the current state of knowledge of novel therapies against GEP-NETs, including the use of somatostatin analogs with broader receptor binding profiles, chimeric somatostatin-dopamine molecules, combinations of somatostatin analogs with other active chemotherapy agents, and peptide receptor-targeted radionuclide therapy.
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| 33. |
- Dell'Angela, M., et al.
(författare)
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Real-Time Observation of Surface Bond Breaking with an X-ray Laser
- 2013
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 339:6125, s. 1302-1305
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Tidskriftsartikel (refereegranskat)abstract
- We used the Linac Coherent Light Source free-electron x-ray laser to probe the electronic structure of CO molecules as their chemisorption state on Ru(0001) changes upon exciting the substrate by using a femtosecond optical laser pulse. We observed electronic structure changes that are consistent with a weakening of the CO interaction with the substrate but without notable desorption. A large fraction of the molecules (30%) was trapped in a transient precursor state that would precede desorption. We calculated the free energy of the molecule as a function of the desorption reaction coordinate using density functional theory, including van der Waals interactions. Two distinct adsorption wells-chemisorbed and precursor state separated by an entropy barrier-explain the anomalously high prefactors often observed in desorption of molecules from metals.
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| 34. |
- Drakvik, E., et al.
(författare)
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Statement on advancing the assessment of chemical mixtures and their risks for human health and the environment
- 2020
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 134
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Tidskriftsartikel (refereegranskat)abstract
- The number of anthropogenic chemicals, manufactured, by-products, metabolites and abiotically formed transformation products, counts to hundreds of thousands, at present. Thus, humans and wildlife are exposed to complex mixtures, never one chemical at a time and rarely with only one dominating effect. Hence there is an urgent need to develop strategies on how exposure to multiple hazardous chemicals and the combination of their effects can be assessed. A workshop, “Advancing the Assessment of Chemical Mixtures and their Risks for Human Health and the Environment” was organized in May 2018 together with Joint Research Center in Ispra, EU-funded research projects and Commission Services and relevant EU agencies. This forum for researchers and policy-makers was created to discuss and identify gaps in risk assessment and governance of chemical mixtures as well as to discuss state of the art science and future research needs. Based on the presentations and discussions at this workshop we want to bring forward the following Key Messages: • We are at a turning point: multiple exposures and their combined effects require better management to protect public health and the environment from hazardous chemical mixtures. • Regulatory initiatives should be launched to investigate the opportunities for all relevant regulatory frameworks to include prospective mixture risk assessment and consider combined exposures to (real-life) chemical mixtures to humans and wildlife, across sectors. • Precautionary approaches and intermediate measures (e.g. Mixture Assessment Factor) can already be applied, although, definitive mixture risk assessments cannot be routinely conducted due to significant knowledge and data gaps. • A European strategy needs to be set, through stakeholder engagement, for the governance of combined exposure to multiple chemicals and mixtures. The strategy would include research aimed at scientific advancement in mechanistic understanding and modelling techniques, as well as research to address regulatory and policy needs. Without such a clear strategy, specific objectives and common priorities, research, and policies to address mixtures will likely remain scattered and insufficient. © 2019 The Authors
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| 35. |
- Einig, Lucas, et al.
(författare)
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Deep learning denoising by dimension reduction: Application to the ORION-B line cubes
- 2023
-
Ingår i: Astronomy and Astrophysics. - 0004-6361 .- 1432-0746. ; 677
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Tidskriftsartikel (refereegranskat)abstract
- Context. The availability of large bandwidth receivers for millimeter radio telescopes allows for the acquisition of position-position-frequency data cubes over a wide field of view and a broad frequency coverage. These cubes contain a lot of information on the physical, chemical, and kinematical properties of the emitting gas. However, their large size coupled with an inhomogenous signal-to-noise ratio (S/N) are major challenges for consistent analysis and interpretation. Aims. We searched for a denoising method of the low S/N regions of the studied data cubes that would allow the low S/N emission to be recovered without distorting the signals with a high S/N. Methods. We performed an in-depth data analysis of the 13CO and C17O (1-0) data cubes obtained as part of the ORION-B large program performed at the IRAM 30 m telescope. We analyzed the statistical properties of the noise and the evolution of the correlation of the signal in a given frequency channel with that of the adjacent channels. This has allowed us to propose significant improvements of typical autoassociative neural networks, often used to denoise hyperspectral Earth remote sensing data. Applying this method to the 13CO (1-0) cube, we were able to compare the denoised data with those derived with the multiple Gaussian fitting algorithm ROHSA, considered as the state-of-the-art procedure for data line cubes. Results. The nature of astronomical spectral data cubes is distinct from that of the hyperspectral data usually studied in the Earth remote sensing literature because the observed intensities become statistically independent beyond a short channel separation. This lack of redundancy in data has led us to adapt the method, notably by taking into account the sparsity of the signal along the spectral axis. The application of the proposed algorithm leads to an increase in the S/N in voxels with a weak signal, while preserving the spectral shape of the data in high S/N voxels. Conclusions. The proposed algorithm that combines a detailed analysis of the noise statistics with an innovative autoencoder architecture is a promising path to denoise radio-astronomy line data cubes. In the future, exploring whether a better use of the spatial correlations of the noise may further improve the denoising performances seems to be a promising avenue. In addition, dealing with the multiplicative noise associated with the calibration uncertainty at high S/N would also be beneficial for such large data cubes.
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| 36. |
- Elsner, J, et al.
(författare)
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Theory of threading edge and screw dislocations in GaN
- 1997
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 79:19, s. 3672-3675
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Tidskriftsartikel (refereegranskat)abstract
- The atomic structures, electrical properties, and line energies for threading screw and threading edge dislocations of wurtzite GaN are calculated within the local-density approximation. Both dislocations are electrically inactive with a band gap free from deep levels. These results are understood to arise from relaxed core structures which are similar to (101̅ 0) surfaces.
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| 37. |
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| 38. |
- Estreicher, S.K., et al.
(författare)
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Stable and metastable states of C60H: buckminsterfullerene monohydride
- 1992
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Ingår i: Chemical Physics Letters. - 0009-2614 .- 1873-4448. ; 196:3-4, s. 311-316
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Tidskriftsartikel (refereegranskat)abstract
- Approximate ab initio Hartree-Fock and first-principles density functional calculations of potential energy surfaces and electronic structures of C60H show that the stable state has H attached to one C atom, outside the buckyball. This C atom is displaced radially outward and is close to being sp3 hybridized. The unpaired electron of C60H is delocalized. The calculated Fermi contact density at the proton is in good agreement with recent low-temperature μSR data. A metastable configuration has atomic H at the center of the ball (H@C60). Once trapped there, H must overcome a large barrier to go through the surface of C60. Other configurations we considered include H attached to one C atom but inside the buckyball, and H bridging one of the two inequivalent CC bonds. The barrier for diffusion of H from outside to the center of C60 have also been calculated. The results are compared to recent muon spin rotation studies in solid C60 and to the states of hydrogen in other forms of carbon.
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| 39. |
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| 40. |
- Fayolle, E. C., et al.
(författare)
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Protostellar and cometary detections of organohalogens
- 2017
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Ingår i: Nature Astronomy. - : Springer Science and Business Media LLC. - 2397-3366. ; 1:10, s. 703-708
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Tidskriftsartikel (refereegranskat)abstract
- Organohalogens, a class of molecules that contain at least one halogen atom bonded to carbon, are abundant on the Earth where they are mainly produced through industrial and biological processes(1). Consequently, they have been proposed as biomarkers in the search for life on exoplanets(2). Simple halogen hydrides have been detected in interstellar sources and in comets, but the presence and possible incorporation of more complex halogen-containing molecules such as organohalogens into planet-forming regions is uncertain(3,4). Here we report the interstellar detection of two isotopologues of the organohalogen CH3Cl and put some constraints on CH3F in the gas surrounding the low-mass protostar IRAS 16293-2422, using the Atacama Large Millimeter/submillimeter Array (ALMA). We also find CH3Cl in the coma of comet 67P/Churyumov-Gerasimenko (67P/C-G) by using the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument. The detections reveal an efficient pre-planetary formation pathway of organohalogens. Cometary impacts may deliver these species to young planets and should thus be included as a potential abiotical production source when interpreting future organohalogen detections in atmospheres of rocky planets.
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| 41. |
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| 42. |
- Fransson, Göran, 1968-, et al.
(författare)
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On the Swedish National Grade School for Digital Technologies in Education – GRADE : Expectations and experiences of doctorial students and supervisors
- 2018
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Ingår i: ICERI2018 Proceedings. - Sevilla : IATED. - 9788409059485 ; , s. 769-774
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Konferensbidrag (refereegranskat)abstract
- The Swedish National Graduate School for Digital Technologies in Education (GRADE) is a cooperative venture between six Swedish universities established during 2018. Within the field of educational sciences and in the area of digital technologies in education, GRADE aims to strengthen the expertise in the area and to increase national and international cooperation in research training activities.Over a number of years, and from multitude of sources (cf. Brown & Davis, 2004; Fisher, Higgins & Loveless, 2006; Kafai & Resnick 1996), research has stressed that increased digitalization in schools leads to a complexity that needs to be taken into account on different levels, from different perspectives and with different designs, methodologies and theoretical perspectives (cf. Olofsson, Lindberg, Fransson & Hauge, 2015; Price, Jewitt & Brown, 2013; Tondeur, Valcke & van Braak, 2008). At a micro-level, the learning situation of students, teachers and school-leaders changes and it becomes important to deepen the knowledge about the impact digital technologies has on the fundamental conditions for teaching and learning of different school subjects (cf. Chun, Kern & Smith 2016; Leung & Baccaglini-Frank, 2017). On a macro-level, conditions for education as such changes and digital technologies becomes an important object of study as agents of change (Wong & Li, 2008). The digitalization of K-12 schools has long been highlighted in policy as a necessity (cf. Kirkman et al, 2002; OECD, 2010). However, research and evaluations (cf. Fransson et al, 2012; OECD, 2015; Wastiau et al, 2013) show that many substantial challenges remain. One of the fundamental pillars of GRADE is the interdisciplinary approach. Several disciplines are present (Applied IT, Curriculum studies, Education, Informatics, Technology and Learning, Educational work, Work-interated Learning) in researching digital technologies in K-12 schools with the ambition to contribute to the continued implementation, integration and use of digital technologies in Swedish K-12 schools that stems from the evidence-based knowledge produced within the activities of GRADE. The research within GRADE will be characterized by close cooperation with stakeholders from school practice, with the aim to contribute to concrete school development. In GRADE, a multi-level approach that involves multiple layers or levels of school activities will be encouraged. When possible, studies will be longitudinal. This will imply studies from an organizational and management perspective, e.g. studies of school leaders and other members of senior management positions responsible for digital technology use and implementation. Also implied are studies of teachers' teaching practices and didactical considerations, as well as studies of the students in classrooms and their learning using digital technologies. This will also imply that several issues with a bearing on the digitalization of education, for example regarding school policy, teaching, learning, assessment and professional development will be researched from different perspectives and with different methodological approaches. In this paper, these points of departure will be explored based on the expectations and experiences of the first twelve admitted doctoral students and their supervisors.
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| 43. |
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| 44. |
- Goss, J.P., et al.
(författare)
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Interstitial aggregates in diamond
- 2001
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Ingår i: Diamond and related materials. - 0925-9635 .- 1879-0062. ; 10:3, s. 434-438
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Tidskriftsartikel (refereegranskat)abstract
- Theoretical modelling of magnetic resonance signals lead to convincing models for the first three self-interstitial aggregates in diamond. These in turn suggest the manner in which larger more stable aggregates including the platelet, observed in annealed type I diamonds, are formed.
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| 45. |
- Goss, J.P., et al.
(författare)
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Self-interstitial aggregation in diamond
- 2001
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 63:19, s. 195208-
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Tidskriftsartikel (refereegranskat)abstract
- First-principles methods are used to investigate the self-interstitial and its aggregates in diamond. The experimental assignment of the spin-1 R2 EPR center to the single interstitial has been questioned because of the small fine-structure term observed. We calculate the spin-spin interaction tensor for the three interstitial defects I1〈001〉, I2NN, and I3 and compare with the experimental D tensors. The results give support for the assignments of the single and di-interstitials to microscopic models and allow us to conclusively identify a recently observed EPR center, O3, with I3. This identification, in turn, suggests a low-energy structure for I4 and a generic model for an extended defect called the platelet. We also determine the optical properties of I1〈001〉 as well as its piezospectroscopic or stress tensor and find these to be in agreement with experiment. Several multi-interstitial defects are found to possess different structural forms which may coexist. We propose that a different form of the charged I2 defect gives rise to the 3H optical peak. Several structures of the platelet are considered, and we find that the lowest-energy model is consistent with microscopic and infrared studies.
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| 46. |
- Grama, D, et al.
(författare)
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Clinical characteristics, treatment and survival of pancreatic tumors causing hormonal syndromes
- 1992
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Ingår i: World Journal of Surgery. - 0364-2313 .- 1432-2323. ; 16:4, s. 632-639
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Tidskriftsartikel (refereegranskat)abstract
- Eighty-five patients with endocrine pancreatic tumors associated with clinical syndromes of hormone excess were retrospectively analyzed regarding symptomatology, means of diagnosis, and results of surgical and medical treatment during follow-up of 3-18 years (median 8 years). The combination of angiography and computed tomography was most successful in pre-operative localization of both primary tumors and metastases. Surgery provided long term cure in 39 of 44 patients with benign islet cell lesions, the majority having insulinomas. Forty-one patients had malignant tumors, which at the time of diagnosis or operation were associated with liver and/or regional lymph gland metastases in 56% and 24%, respectively. Sixteen patients with metastatic disease and/or very large tumors were considered inoperable, 5 patients underwent palliative resection of their malignant tumors, while grossly radical tumor removal was accomplished in 20 patients. Long-term cure was achieved in 5 patients by excision of primary tumors and localized liver or lymph gland metastases. Half of the patients, particularly those with insulinoma, gastrinoma, or vipoma, showed response to streptozotocin, in combination with other cytostatics, for a median of 24 months or a response to interferon for a median of 10 months. The overall 5-year and 10-year survival among the patients with malignant islet cells tumors was 54% and 28%, respectively. Absence of liver metastases at time of operation/diagnosis, smaller size of the primary tumor, grossly radical tumor resection as well as response to medical therapy predicted the more favorable survival.
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| 47. |
- Grama, D, et al.
(författare)
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Pancreatic tumors in multiple endocrine neoplasia type 1 : clinical presentation and surgical treatment
- 1992
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Ingår i: World Journal of Surgery. - 0364-2313 .- 1432-2323. ; 16:4, s. 611-618
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Tidskriftsartikel (refereegranskat)abstract
- Among 33 patients with endocrine pancreatic tumors due to multiple endocrine neoplasia type 1 (MEN-1), 19 (58%) patients had hypergastrinemia, 7 (21%) patients had hyperinsulinism, and 7 (21%) patients had clinically non-functioning lesions. At least one gross tumor was found in all patients undergoing pancreatic surgery, including those with negative localization studies prior to operation. The patients also had additional macroscopic tumors as well as numerous microadenomas, and the lesions frequently were positive for immunostaining with multiple hormones, mainly pancreatic polypeptide, insulin, glucagon, and somatostatin. Duodenal endocrine lesions were found in 4 of 5 investigated patients and stained with gastrin and somatostatin antibodies. Distal, mainly subtotal pancreatic resection, was performed in 18 patients, eventually combined with caput tumor enucleation or duodenotomy, while a few patients underwent only tumor enucleation or a Whipple procedure. The long-term outcome of operation was most favorable in patients with hyperinsulinism; only 1 patient had clinical recurrence. Patients with hypergastrinemia experienced only transitory lowering of serum gastrin values after pancreatic surgery and 47% of them had or developed metastases. Such tumor spread was seen in 57% of the patients with non-functioning lesions. Nine patients died from progressive tumor disease during follow-up. Consistent with previous studies, we found that surgery is indicated in MEN-1 patients with hyperinsulinism even if a lesion is not visualized by radiology. In addition, these indications should be extended to also include patients with only biochemical markers of disease, including elevations of gastrin, as these indicate the presence of gross tumors.
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| 48. |
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| 49. |
- Holbech, J. D., et al.
(författare)
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H2* defect in crystalline silicon
- 1993
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 71:6, s. 875-878
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Tidskriftsartikel (refereegranskat)abstract
- Detailed infrared studies have been carried out on proton- and deuteron-implanted Si. A dominant trigonal defect involving a pair of inequivalent hydrogen atoms has been identified, with local modes at 2061.5, 1838.3, 1599.1, and 817.2 cm-1. The structure, the local modes, and the isotopic shifts of the H2* defect have been calculated using ab initio pseudopotential cluster theory. The structure is consistent with channeling and uniaxial stress experiments. The calculated frequencies and isotopic shifts are in close agreement with those observed.
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| 50. |
- Hounsome, L.S., et al.
(författare)
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Origin of brown coloration in diamond
- 2006
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 73:12, s. 125203-1
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Tidskriftsartikel (refereegranskat)abstract
- Measurements of the absorption spectra of brown natural type IIa diamond as well as brown nitrogen-doped CVD diamond are reported. These are largely featureless and increase almost monotonically from about 1-5.5 eV. It is argued that the brown coloration is due to an extended defect and not to a point defect. First principles modeling studies demonstrate that the spectra could be attributed to vacancy disks lying on {111} planes. Such disks are unstable above about 200 vacancies and should relax to dislocation loops in natural diamond. Hydrogen is shown to passivate the optical activity of the disks.
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