Search

This paper reports on results obtained by electron paramagnetic resonance (EPR) measurements and Monte Carlo (MC) simulation on a blend of alanine added with low content of gadolinium oxide (5 % by weight) to improve the sensitivity to thermal neutron without excessively affecting tissue equivalence. The sensitivity is enhanced by this doping procedure of more an order of magnitude. The results are compared with those obtained with the addition of boric acid (50 % by weight) where boron is in its natural isotopic composition in order to produce low-cost EPR dosemeters. The gadolinium addition influences neutron sensitivity more than the boron addition. The presence of additives does not substantially change the fading of the EPR signal induced by neutrons. The MC simulations agree the experimental results in case of gadolinium addition. [ABSTRACT FROM AUTHOR]

Abstract Background International treatment guidelines recommend administration of adjuvant chemotherapy in early breast cancer based on clinical, prognostic and predictive parameters. Methods An observational study (NEMESI) was conducted in 63 Italian oncology centres in patients with early breast cancer. Age, performance status, concomitant disease, menopausal status, histology, tumor dimension (pT), axillary lymph node status (pN), grading (G), estrogen and progesterone receptor (ER and PgR), proliferative index (ki67 or MIB-1), human epidermal growth factor receptor 2 (HER2) and type of adjuvant treatment were recorded. The primary objective of the study was to define parameters influencing the decision to prescribe adjuvant chemotherapy and the type of chemotherapy. Results Data for 1894 patients were available. 69.0% postmenopausal, 67.0% pT1, 22.3% pTmic/pT1a/pT1b, 61.0% pN0, 48.7% luminal A, 18.1% luminal B, 16.1% HER2 positive, 8.7% triple negative, 8.4% unknown. 57.8% received adjuvant chemotherapy: 38.1% of luminal A, 67.3% luminal B, 88.2% HER2-positive, 97.6% triple negative. Regimens administered: 9.1% CMF-like, 48.8% anthracyclines, 38.4% anthracyclines plus taxanes, 3.7% taxanes alone. Increasing pT/pN and, marginally, HER2-positive were associated with the prescription of anthracyclines plus taxanes. Suboptimal schedules (CMF-like or AC/EC or FEC-75) were prescribed in 37.3% receiving chemotherapy, even in HER2-positive and triple negative disease (36.5% and 34.0%, respectively). Conclusions This study showed an overprescription of adjuvant chemotherapy for early breast cancer, particularly referred to luminal A. pT, pN and, marginally, HER2 were the principal determinants for the choice of chemotherapy type. Suboptimal chemotherapy regimens were adopted in at least one third of HER2-positve and triple negative.

Abstract Background The prognosis of pT1a-pT1b breast cancer (BC) used to be considered very good, with a 10-y RFS of 90%. However, some retrospective studies reported a 10-y RFS of 81%–86% and suggested benefit from adjuvant systemic therapy. Methods To evaluate the variables that determined the choice of adjuvant chemotherapy and the type of chemotherapy delivered in pT1a-pT1b BC, we analysed the small tumours enrolled in the NEMESI study. Results Out of 1,894 patients with pathological stage I-II BC enrolled in NEMESI, 402 (21.2%) were pT1a-pT1b. Adjuvant chemotherapy was delivered in 127/402 (31.59%). Younger age, grading G3, high proliferative index, ER-negative and HER2-positive status were significantly associated with the decision to administer adjuvant chemotherapy. An anthracycline without taxane regimen was administered in 59.1% of patients, anthracycline with taxane in 24.4%, a CMF-like regimen in 14.2% and taxane in 2.4%. Adjuvant chemotherapy was administered in 88.4% triple-negative and 73.46% HER2-positive pT1a-pT1b BC. Adjuvant trastuzumab was delivered in 30/49 HER2-positive BC (61.2%). Conclusions Adjuvant chemotherapy was delivered in 31.59% T1a-pT1b BC treated at 63 Italian oncological centres from January 2008 to June 2008. The choice to deliver chemotherapy was based on biological prognostic factors. Anthracycline-based chemotherapy was administered in 83.5% patients.

This paper reports the results regarding a new organic compound (IRGANOX ® 1076 phenols) with and without low content (5% by weight) of gadolinium oxide (Gd 2 O 3 ) for Electron Paramagnetic Resonance (EPR) dosimetry of neutron beams. The dependence of EPR signal as function of neutron dose was investigated in the fluence range studied between 10 11 cm −2 to 10 14 cm −2 . We evaluated also the effect of gadolinium on 60 Co gamma photon sensitivity of this organic compound. Our analysis showed that a low concentration of gadolinium oxide (of the order of 5% of the total mass of the dosimeter) can enhance the thermal neutron sensitivity more than 10 times with a small reduction of photon tissue equivalence. The free radicals produced after irradiation of photons and neutrons are stable for more than first 300 h after irradiation. The presence of additives does not substantially modify the fading of the EPR signal induced by photons and neutrons in the first 15 days after exposure. [ABSTRACT FROM AUTHOR]

In the present paper we investigate the features of IRGANOX® 1076 phenols as a material for electron spin resonance (ESR) dosimetry. We experimentally analyzed the ESR response of pellets of IRGANOX® 1076 phenols irradiated with 60 Co photons. The best experimental parameters (modulation amplitude and microwave power) for dosimetric applications have been obtained. The dependence of ESR signal as function of γ dose is found to be linear in the dose range studied (12–60 Gy) and the lowest measurable dose is found to be of the order of 1 Gy. The signal after irradiation is very stable in the first thirty days. From the point of view of the tissue equivalence, these materials have mass energy absorption coefficient values comparable with those of soft tissue. [ABSTRACT FROM AUTHOR]

Abstract: Aims: Triple-negative breast cancers (TNBCs) lack expression of oestrogen, progesterone, and Human Epidermal Growth Factor 2 receptors. The NEMESI study described current Italian treatment practices in patients with operable, early-stage breast cancer (EBC). Patients and methods: Retrospective, observational study involving 63 Italian oncology centres. Eligible patients were aged ⩾18years with EBC (stage I–II) who had undergone surgery, received ⩾1 cycle of adjuvant chemotherapy and/or adjuvant hormonal therapy and attended an oncology centre between 1 January 2008 and 30 June 2008. This subanalysis focused on patients with TNBC. Variables evaluated included: demographic data/clinical characteristics; tumour characteristics; adjuvant therapy; compliance to chemotherapy. Continuous variables were summarised using descriptive statistics. Results: Of 1894 patients in the NEMESI study, 185 patients (9.8%) had TNBC. At diagnosis, 98 patients were aged 50–70years and 114 were post-menopausal. Tumours were subcategorised as pT1mic/pT1a/pT1b/pT1c in 108 patients and pT2/pT3/pT4b in 77 patients. Mean tumour size was 2.1cm, tumours were highly undifferentiated in 144 patients and 128 patients were pNO. 179 patients received adjuvant chemotherapy; anthracyclines with or without taxanes were commonly used. 145 patients received radiotherapy. Conclusions: Adherence of Italian clinical practice to International Guidelines in the management of early-stage TNBC is satisfactory. [Copyright &y& Elsevier]

Background: Concomitant chemoradiotherapy (CT/RT) is the standard treatment of locally advanced squamous cell carcinoma of the head and neck (SCCHN). We evaluated the efficacy of induction docetaxel (Taxotere), cisplatin, and 5-fluorouracil (TPF) before CT/RT versus CT/RT alone. [ABSTRACT FROM PUBLISHER]

Abstract: We present latest results on the development of a new solid electrolyte for DMFC application. Films are obtained through fluorine-free chemistry consisting of grafting reaction between polyethylene film, preliminary irradiated, and styrene monomers. This reaction proceeds through the formation of hydroperoxide groups activated by ferrous catalyst that initiates the polymerization reaction with styrene. Sulfonic groups are then introduced on the aromatic rings by sulfonation with chlorosulfonic acid. Functional properties of membranes are then characterized out of cell through ion conductivity and methanol permeability measurements. Obtained results are very promising for application in DMFC. [Copyright &y& Elsevier]

Abstract: Low temperature matrix EPR spectroscopy was employed to investigate the free radical intermediates in the solid state radiolysis of poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT), poly(ethylene naphthalate) (PEN), poly(1,4-cyclohexanedimethylene terephthalate-co-ethylene terephthalate) (PCT-co-ET) and poly(ethylene adipate) (PEA). With PEA the species identified is consistent with the formation of carbon centred radicals stemming from electron capture, C–O scissions and H abstractions, the most abundant species at room temperature being the α-ester radical, –CH2–CH –COO–. The radiolysis of PEN is characterized by the predominance of radicals arising from the aromatic section, the preferred reaction being the H atom addition at a position adjacent to the ester unit, leading to the formation of cyclohexadienyl type radicals. In the copolymer, PET and PBT, the role played by the aliphatic and aromatic sections with respect to radical forming processes is of comparable importance. The cyclohexadienyl radicals arising from these latter polymers are reckoned with the prominent H addition at the sites adjacent to the esters groups which are also statistically favoured. The reactivity distribution in the aromatic rings with respect to the formation of cyclohexadienyls was analyzed in greater detail by comparing the experimental results with DFT B3LYP M.O. calculations. The DFT method has also been employed for assessing the EPR properties of the cyclohexadienyl and ion-radicals from PEN and PET models. [Copyright &y& Elsevier]

Abstract: The yields and spatial distribution of the products arising from the in source oxidation of 50μm LDPE films induced by 60-Co gamma radiations and by 300kev electrons have been investigated as a function of the dose rate. The dose rate was found to have a strong influence on the reaction, the hydroperoxides and carbonyls yields at the lowest gamma dose rate of 0.04kGy/h being decreased by a factor of about three with increasing the gamma dose rate up to 0.69kGy/h and by a factor of about 30 when operating at the e-beam dose rate of 1.5kGy/s. The carbonyls depth concentration profiles, the EPR measurements on radicals intermediates and the experiments of post-irradiation oxidation are consistent with the conclusion that, as far as the gamma irradiation is concerned, the observed dose rate effects cannot be imputed to oxygen diffusion control and/or to the chain branching via hydroperoxides decomposition coupled to the longer times between the initiation events. The hypothesis of the dose rate acting on the kinetic chain length of the radioxidation which in turn implies a substantially uniform distribution of radicals in the amorphous phase attained through spur expansion is proposed. [Copyright &y& Elsevier]

The presence of a Fe3+ selective ligand plays a key role in Fricke-gel dosimeters to preserve the 3D absorbed dose distribution. In this study, a novel Fe3+ selective ligand is proposed to overcome several limitations related to the use of the reference ligand, Xylenol Orange (XO). For this purpose, an affordable iron (III) ligand with an easy synthetic route was used. The complexation mechanism was investigated, and a single stoichiometry Fe3+-Ligand complex was identified, thus allowing a more accurate and feasible dose evaluation. The Fricke-gel dosimeter prepared with this new ligand was fully characterized by means of both optical and Magnetic Resonance Imaging (MRI) analysis. In particular, a reduction of the optical artefacts, the so-called dose threshold, and an improvement of the Signal to Noise Ratio (SNR) in MRI analysis were observed. Finally, the Fe3+-Ligand diffusion coefficient was evaluated for this innovative system and proved to be comparable to the reference ones. • Novel Fe3+ selective ligand L is proposed for Fricke gel dosimetry. • The proposed ligand allows to overcome issues of the reference one, Xylenol Orange. • The complexation mechanism of ligand and Fe3+ ions was studied via optical analysis. • Optical and MRI characterization of the new dosimetric system has been conducted. • Diffusion process was evaluated via analytical approach. [ABSTRACT FROM AUTHOR]