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Industrial borosilicate glasses containing fission products and minor actinides can be subjected to structural damage caused mainly by $$\alpha $$ -self-irradiation effects. In this field of glasses under extreme conditions, we present an X-ray Absorption Near-Edge Structure investigation of two six-oxide borosilicate curium-doped glasses (based on the International Simplified Glass (ISG) composition). The first sample is an 8-year ISG damaged glass, which has already accumulated an $$\alpha $$ -decay dose greater than 6.10 $$^{18}$$ $$\alpha $$ g $$^{-1}$$ , a value corresponding to a damaged but stabilized structural state. The second sample results from annealing of the latter ISG damaged glass. Three species, Cm, Pu and Zr were probed at $$L_{3}$$ -edge, $$L_{3}$$ -edge and K-edge, respectively. From the experimental results, Cm and Pu species appear respectively in +3 and +4 oxidation states in both glasses. No Cm local environment changes are observed. In contrast, a small variation in Pu local environment appears between the damaged and annealed glasses, reflecting a possible coordination variation or Pu–Zr substitution. A more drastic effect appears for Zr local environment, where a sevenfold coordinated site grows over time under $$\alpha $$ -self-irradiation effects, at the expense of the initial major sixfold site of symmetry. Moreover, annealing the damaged glass does not permit to retrieve a similar structural state to the one of a just melted curium-doped ISG.

This paper presents the results of a series of wind engineering studies, including high-frequency force balance boundary-layer wind tunnel tests conducted to assess the wind effects relevant to the structural and serviceability design of a proposed 400+ m high-rise scheme in the Middle East. The development of the architectural scheme allowed the design team to explore different levels of porosity for the façade of the building over the top third of the structure. The primary aim of these studies was to optimise the building design, minimising the overall dynamic structural wind loading and wind-induced accelerations. Details of the structural lateral-stability system employed in the design and key considerations on the potential use of alternative devices are given. A detailed comparison of the wind-induced structural response for a nominally sealed scheme – taking into account the contribution of additional damping – against the benefits arising from the employment of a permeable solution is presented. The technical challenges are illustrated from both a structural and cladding design viewpoint – the latter being related to the use of a porous skin over the architectural feature at the top of the tower. A brief description of the planned next phase of wind engineering work – aimed to assess the overall wind loading applicable to the design of the porous envelope as well as the potential for wind-induced noise and vibration of its elements to occur – is also given.

Fe–Cu alloys containing 1.3 at.% copper were studied as model systems for cluster formation in reactor pressure vessel steels. The samples were annealed at 775 K for different times and subsequently analyzed using X-ray absorption fine structure spectroscopy at the Cu–K-edge, X-ray diffraction and transmission electron microscopy. The results show that copper cluster formation might occur even with short annealing times. These clusters of about 1 nm size can switch easily from bcc iron-like structures to fcc copper, if the local copper concentration is high enough. While a short annealing time of 2.5 h at 775 K maintains a good dilution of copper in the bcc iron matrix, annealing for 312 h leads to large fcc copper precipitates. A linear combination analysis suggests that in the sample annealed 8 h, copper clusters are mostly formed with the same structure as the matrix. A co-existence of bcc and fcc clusters is obtained for 115 h of annealing. Transmission electron microscopy indicates the presence of precipitates as large as 60 nm size for an annealing time of 312 h, and X-ray diffraction provided complementary data about the clusters size distributions in all of the four samples.

Copper and nickel impurities in nuclear reactor pressure vessel (RPV) steel can form nano-clusters, which have a strong impact on the ductile–brittle transition temperature of the material. Thus, for control purposes and simulation of long irradiation times, surveillance samples are submitted to enhanced neutron irradiation. In this work, surveillance samples from a Swiss nuclear power plant were investigated by extended X-ray absorption fine structure spectroscopy (EXAFS). The density of Cu and Ni atoms determined in the first and second shells around the absorber is affected by the irradiation and temperature. The comparison of the EXAFS data at Cu and Ni K-edges shows that these elements reside in arrangements similar to bcc Fe. However, the EXAFS analysis reveals local irradiation damage in the form of vacancy fractions, which can be determined with a precision of ∼5%. There are indications that the formation of Cu and Ni clusters differs significantly.

The radiation damage produced in reactor pressure vessel (RPV) steels during neutron irradiation is a long-standing problem of considerable practical interest. In this study, an extended X-ray absorption fine structure (EXAFS) spectroscopy has been applied at Cu, Ni and Mn K-edges to systematically investigate neutron induced radiation damage to the metal-site bcc structure of RPV steels, irradiated with neutrons in the fluence range from 0.85 to 5.0 × 1019 cm−2. An overall similarity of Cu, Ni and Mn atomic environment in the iron matrix is observed. The radial distribution functions (RDFs), derived from EXAFS data have been found to evolve continuously as a function of neutron fluence describing the atomic-scale structural modifications in RPVs by neutron irradiations. From the pristine data, long range order beyond the first- and second-shell is apparent in the RDF spectra. In the irradiated specimens, all near-neighbour peaks are greatly reduced in magnitude, typical of damaged material. Prolonged annealing leads annihilation of point defects to give rise to an increase in the coordination numbers of near-neighbour atomic shells approaching values close to that of non-irradiated material, but does not suppress the formation of nano-sized Cu and/or Ni-rich-precipitates. Total amount of radiation damage under a given irradiation condition has been determined. The average structural parameters estimated from the EXAFS data are presented and discussed.

Reactor pressure vessel (RPV) reference steel samples submitted to neutron irradiations followed by thermal annealing were investigated by X-ray absorption fine structure (XAFS) spectroscopy. Several studies revealed that Cu and Ni impurities can form nanoclusters. In the unirradiated sample and in the only-irradiated sample no significant clustering is detected. In all irradiated and subsequently annealed samples increases of Cu and Ni atom densities are recorded around the absorber. Furthermore, the density of Cu and Ni atoms determined in the first and second shells around the absorber is found to be affected by the irradiation and annealing treatment. The comparison of the XAFS data at Cu and Ni K-edges shows that these elements reside in arrangements similar to bcc Fe. However, the local irradiation damage yields vacancy fractions which were determined from the analysis of XAFS data with a precision of ∼5%.

Introduction: The detailed knowledge of mechanisms of DNA lesion repair is crucial in many areas, from cancer cell killing by radiotherapy to proper immune system development to cell aging, just to quote a few examples. The purpose of this work was to study both qualitatively and quantitatively some novel DNA damage markers. Results: Our data show that at high DNA damage load cells with different sensitivity respond in an indistinguishable way. At lower DNA damage load, instead, it is possible to differentiate between cells with different damage sensitivity. Conclusions: These new immunofluorescence-based markers could be useful for studying by means of ionizing radiations the different sensitivity of cells to DNA damage.

This paper reports the characterization of ternary II-VI semiconductor nanocrystals, deposited by the electrochemical atomic layer epitaxy (ECALE) technique. In particular, morphological and structural properties of the ternary compounds of formula CdxZn1-xSe deposited on Ag (1 1 1) have been characterized as a function of composition. The number of the attainable x values is limited by the necessity of using well-defined ZnSe/CdSe deposition sequences. However, the quantitative analysis carried Out Oil the basis of both electrochemical and extended X-ray absorption fine structure (EXAFS) experiments indicates that the ECALE method is a successful way of controlling the composition of CdxZn1-xSe. In addition, the electrochemical measurements show that the amount of deposition is minimum in correspondence to the compound with x=0.5, thus corroborating the hypothesis of a higher degree of disorder suggested both by morphological and structural investigation. The morphology was studied by atomic force microscopy (AFM). The structure of the films is estimated by EXAFS which is a Powerful technique for the analysis of the local structure around chosen atoms. (c) 2008 Elsevier Ltd. All rights reserved.

Purpose: To find an answer to the question: Are the acute radiation effects on salivary gland function, as seen in earlier studies, causally related to radiation-induced apoptosis? Materials and methods: Rat parotid and submandibular glands were X-irradiated with doses up to 25 Gy and morphological damage assayed up to 6 days after irradiation. Damage to the different cell types in the glands was assessed after H & E staining. Apoptotic appearance was judged by compacted chromatin and fragmentation of cells into lobulated masses. Results: In about 3% of the cells aberrant nuclei were observed after doses as low as 2 Gy and around 7.5 and 24 h after irradiation. About half of these aberrant nuclei had an apoptotic appearance. After a dose of about 5 Gy no dose-response for apoptotic cells was found, as evidenced by a plateau in the dose-effect curve. At 6 days after 2 Gy, no signs of radiation-induced apoptosis was apparent and for most cell types a value close to zero was observed. Conclusions: Radiation studies on salivary function in the rat show the typical response with respect to;lose (5-15 Gy) and time (1-3 days). This differs from reported findings with light microscopy. Therefore, the extent of apoptotis induced by radiation cannot explain the observed gland malfunction. Alternative mechanisms are proposed.

EXAFS is an important experimental technique for determining the local atomic structure of nanoclusters embedded in a bulk material. In practical cases, nanocluster samples do not contain homogeneous clusters of just one size, and the average cluster size is strongly influenced by the specific distribution of cluster sizes. Combinations of different cluster sizes might provide very similar results; this issue is called polydispersity. The goal of this study is to understand if there are any principal limitations for EXAFS studies related to polydispersity. Here a new approach based on EXAFS simulations followed by linear combination (LC) on EXAFS spectra is presented. The simulations were performed on pure Cu and binary Cu-Fe clusters. The main result of this study concerns the proof that polydispersity does not affect XAFS studies on nano-clusters within a size of up to 140 atoms.

Pancreatic cancer (PaC) will soon be one of the main causes of cancer mortality. Furthermore, its incidence is higher in the older population and radiotherapy (RT) represents a treatment option. The aim of this review was to evaluate feasibility and outcome of RT in older patients with PaC. A systematic literature review of patients aged ≥65 years with PaC treated with RT was performed using the PRISMA methodology. Eleven papers (1830 patients) fulfilled our inclusion criteria and were analyzed. RT was prescribed either alone or as an adjuvant treatment. Prescribed RT dose ranged from 22.0 to 70.0 Gy with conventional fractionation or hypo-fractionated schedule and delivered by three-dimensional conformal RT, intensity modulated RT or stereotactic body RT. Grade ≥ 3 acute and grade ≥ 2 late toxicity rates ranged between 0.0% and 52.6% (median: 0.5%) and between 0.0% and 15.0% (median: 0%), respectively. Median overall survival and two-year survival rate were 11.3 months (range: 6.4–69.0 months) and 49.0% (range 6.6–75.5%), respectively. RT in older patients seems to be tolerable and safe particularly in terms of late toxicity irrespective of the treatment settings. Therefore, RT can represent a treatment option in PaC even in an older population. Further analyses and prospective trials enrolling older patients are needed to better define the risk/benefit ratio in different treatment settings.

Background Soft tissue sarcomas are often inappropriately excised; it is, however, still a matter of debate whether the presence of residual disease in the re-excision specimen can affect patients’ prognosis. The aim of this study is to investigate the impact of re-excision after unplanned surgery of primary soft tissue sarcomas (STS) of the extremities. Patients and methods We retrospectively evaluated 452 adults with grade 2–3, localized STS (349 primary and 103 unplanned excisions). Results In the re-excision group, a full 43% of the patients had residual tumor. The re-excision group achieved a significantly better outcome in terms of sarcoma-specific survival (SS) (p = 0.002), local recurrence (LR) (p = 0.004) and distant metastasis (DM) (p = 0.028). Residual tumor was associated with a higher risk of DM (p = 0.005). Conclusion We confirm that unplanned surgery does not compromise patients’ prognosis; scar re-excision guarantees at least the same SS, LR and DM rates compared to STS primarily treated in a referral center. Routine use of radiation therapy after re-excision could improve local control. Distant metastases seem to be negatively affected by the presence of residual tumor, and therefore, the use of CT in deep and large STS is suggested. The main goal is to avoid unplanned surgery by referring suspected lumps (especially deep, large, increasing in size) to a specialist center.

Background and purpose : To analyze the treatment results of transperineal 125 Iodine seeds in localized prostate cancer. Patients and methods : Between 1985 and 1996, 102 patients with T1–T2 N0 prostate cancer were treated with transperineal 125 Iodine seed implants at the Academic Medical Centre in Amsterdam. Tumours were classified as T1c in four patients, T2a in 73 patients and T2b in 25 patients. The mean pre-treatment PSA was 17 ng/ml. The 125 Iodine seeds were implanted transperineally under transrectal ultrasound guidance. The mean prostate volume was 31 ml (range 15–48 ml). An average of 49 seeds (range 29–74) was implanted. The dose to the periphery of the prostate was 160 Gy. Until 1988, 27 patients had additional external pelvic irradiation to a dose of 40 Gy in 20 daily fractions of 2 Gy. Results : The 5- and 7-year actuarial survival rates were 77 and 63%, respectively (median 102 months). Ten patients (9.5%) died from prostate cancer. The 5- and 7-year clinical progression rates were 12 and 17%, respectively. Biochemical failure rates at 5 and 7 years were 39 and 44%, respectively. Age, alkaline phosphatase, creatinine, differentiation grade, additional treatment, staging procedure, number of seeds, prostate volume, treatment period and PSA were analyzed as prognostic factors. Only pre-treatment PSA was a prognosticator of clinical and biochemical outcome but not of survival. Biochemical control at 6 years varied from 30% for pre-treatment PSA values higher than 20 ng/ml to 95% for values ≤8 ng/ml. Forty-one out of 49 patients who were sexually active before brachytherapy maintained sexual function during the follow-up. Complete urinary incontinence occurred in one patient. No rectal complications were seen in patients receiving brachytherapy alone. Conclusions : Transperineal 125 Iodine seeds brachytherapy in localized prostate cancer achieves a good clinical control and overall survival with acceptable late toxicity. Biochemical failure was strongly correlated to the pre-treatment PSA value.