367 research outputs found

    Micromachine d'essais mécaniques de type traction et compression ayant une accessibilité optimisée

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    L'invention concerne une micromachine de traction destinée à être utilisée dans une enceinte de microscope électronique à balayage ou avec un appareil de diffraction, comportant deux mors (1) portés par deux supports, chaque mors (1) étant destiné à recevoir une extrémité d'une éprouvette mécanique (4), et des moyens pour exercer sur les supports des efforts tendant à les écarter l'un de l'autre ou à les rapprocher l'un de l'autre selon une direction longitudinale (AL), chaque mors (1) comprenant une embase (2) et une bride (3) pour fixer une extrémité (21) d'éprouvette (4) au mors (1) en l'enserrant entre la bride (3) et l'embase (2) au moyen d'au moins deux vis (12-15 ) traversant chacune la bride (3) et au moins une partie de l'embase (2), ces deux vis (12-15) étant situées de part et d'autre de l'extrémité d'éprouvette (21)

    Concurrent cisplatin, continuous infusion fluorouracil and radiotherapy followed by tailored consolidation treatment in non metastatic anal squamous cell carcinoma

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    BACKGROUND: To evaluate efficacy and feasibility of chemo-radiotherapy in patients with non-metastatic anal squamous-cell-cancer. METHODS: TNM staged anal squamous-cell cancer patients were treated with pelvic radiotherapy concomitant to continuous infusion fluorouracil plus cisplatin for at least 2 cycles. In T3-T4 or any T - N+ tumours or in "slow-responder" cases, 1-2 chemotherapy courses were subsequently administered. Tumour assessment was performed at baseline and 6-8 weeks after radiotherapy to evaluate response. RESULTS: 29 patients were enrolled: 4 males, 25 females; median age 57 years; baseline T1/T2/T3/T4 2/12/7/8; N involvement 17. Median dose pelvic radiotherapy was 59.4 Gy (range: 54-74). In 5 patients 2 chemotherapy courses, in 12 patients three and in 12 patients four courses were performed. At first evaluation, 27 CR (93.1%; 95% CI: 78% - 98%) and 2 SD were observed. Main grade (G) 3 toxic events were neutropenia (8%), diarrhoea (8%) and dermatitis (62%). Most frequent late events G3-G4 occurred in 14 patients: proctitis (5), dermatitis (4), bladder dysfunctions (2), sexual dysfunctions (9), lower extremity venous thromboses (2), dysuria (1), stenosis (1) and tenesmus (1). Five patients reported G1 leucopoenia. The rate of colostomy was 14%. After a median follow up of 42 months (range: 4-81), 20 patients are still alive without relapse and 3 died due to PD. The estimated 7-year DFS was 83.4% (C.I.: 68.3%-98.5%) and the estimated 7-year OS was 85.7% (C.I.: 70% - 100%). The 1-year and the estimated 7-year colostomy-free survivals were 85.9% (C.I.: 73.1% - 98.7%). CONCLUSIONS: Concurrent cisplatin plus fluorouracil and radiotherapy is associated with favourable local control rates and acute toxicity. Future investigations will be directed towards research into molecular biomarkers related to disease progression and resistance to chemo-radiotherapy and to the evaluation of new cytotoxic agents or targeted drugs, such as anti-epidermal growth factor receptor, concomitant to RT and to determining the role of intensity-modulated radiotherap

    Micromachine d'essais mécaniques de type traction et compression ayant une accessibilité optimisée

    Get PDF
    L'invention concerne une micromachine de traction destinée à être utilisée dans une enceinte de microscope électronique à balayage ou avec un appareil de diffraction, comportant deux mors (1) portés par deux supports, chaque mors (1) étant destiné à recevoir une extrémité d'une éprouvette mécanique (4), et des moyens pour exercer sur les supports des efforts tendant à les écarter l'un de l'autre ou à les rapprocher l'un de l'autre selon une direction longitudinale (AL), chaque mors (1) comprenant une embase (2) et une bride (3) pour fixer une extrémité (21) d'éprouvette (4) au mors (1) en l'enserrant entre la bride (3) et l'embase (2) au moyen d'au moins deux vis (12-15 ) traversant chacune la bride (3) et au moins une partie de l'embase (2), ces deux vis (12-15) étant situées de part et d'autre de l'extrémité d'éprouvette (21)

    Role of hydrodynamic factors in controlling the formation and location of unconformity-related uranium deposits: insights from reactive-flow modeling

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    The role of hydrodynamic factors in controlling the formation and location of unconformity-related uranium (URU) deposits in sedimentary basins during tectonically quiet periods is investigated. A number of reactive-flow modeling experiments at the deposit scale were carried out by assigning different dip angles and directions to a fault and various permeabilities to hydrostratigraphic units). The results show that the fault dip angle and direction, and permeability of the hydrostratigraphic units govern the convection pattern, temperature distribution, and uranium mineralization. Avertical fault results in uranium mineralization at the bottom of the fault within the basement, while a dipping fault leads to precipitation of uraninite below the unconformity either away from or along the plane of the fault, depending on the fault permeability. A more permeable fault causes uraninite precipitates along the fault plane,whereas a less permeable one gives rise to the precipitation of uraninite away from it. No economic ore mineralization can form when either very low or very high permeabilities are assigned to the sandstone or basement suggesting that these units seem to have an optimal window of permeability for the formation of uranium deposits. Physicochemical parameters also exert an additional control in both the location and grade of URU deposits. These results indicate that the difference in size and grade of different URU deposits may result from variation in fluid flow pattern and physicochemical conditions, caused by the change in structural features and hydraulic properties of the stratigraphic units involved

    Phase II randomised trial of chemoradiotherapy with FOLFOX4 or cisplatin plus fluorouracil in oesophageal cancer

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    International audienceBackground: Concurrent chemoradiotherapy is a valuable treatment option for localised oesophageal cancer (EC), but improvement is still needed. A randomised phase II trial was initiated to assess the feasibility and efficacy in terms of the endoscopic complete response rate (ECRR) of radiotherapy with oxaliplatin, leucovorin and fluorouracil (FOLFOX4) or cisplatin/fluorouracil. Methods: Patients with unresectable EC (any T, any N, M0 or M1a), or medically unfit for surgery, were randomly assigned to receive either six cycles (three concomitant and three post-radiotherapy) of FOLFOX4 (arm A) or four cycles (two concomitant and two post-radiotherapy) of cisplatin/fluorouracil (arm B) along with radiotherapy 50 Gy in both arms. Responses were reviewed by independent experts. Results: A total of 97 patients were randomised (arm A/B, 53/44) and 95 were assessable. The majority had squamous cell carcinoma (82%; arm A/B, 42/38). Chemoradiotherapy was completed in 74 and 66%. The ECRR was 45 and 29% in arms A and B, respectively. Median times to progression were 15.2 and 9.2 months and the median overall survival was 22.7 and 15.1 months in arms A and B, respectively. Conclusion: Chemoradiotherapy with FOLFOX4, a well-tolerated and convenient combination with promising efficacy, is now being tested in a phase III trial

    Phase I trial of oxaliplatin with fluorouracil, folinic acid and concurrent radiotherapy for oesophageal cancer

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    This dose escalation study was designed to determine the maximum tolerated dose (MTD) and recommended doses (RDs) of 5-fluorouracil (5FU), folinic acid and oxaliplatin (FOLFOX) with concomitant radiotherapy in inoperable/metastatic oesophageal squamous cell carcinoma or adenocarcinoma. Patients received three courses of LV5FU2 regimen (folinic acid 200 mg m−2, bolus 5FU 300–400 mg/m2, continuous infusion 5FU 400–600 mg m−2 on days 1 and 2) and escalating doses of oxaliplatin 50 to 100 mg m−2 on day 1 (FOLFOX). This regimen was repeated every 2 weeks, concomitant to a 50-gray radiotherapy per 5 weeks. Three more cycles were delivered after completion of radiation therapy. Three to six patients were allocated to each of the five dose levels until MTD was reached. Thirty-three patients were enroled and 21 had metastatic disease. Maximum tolerated dose was oxaliplatin 100 mg m−2, and continuous infusion 5FU was 600 mg m−2 day− (level 5). The most common toxicities were neutropenia, dysphagia and oesophagitis. The RDs were those of FOLFOX-4 regimen (oxaliplatin 85 mg m−2 and full doses of LV5FU2). The overall response was 48.5%, including 12% complete response. Response rate on primary tumour was 62.9%. This FOLFOX-4 regimen was reasonably well tolerated and effective in inoperable/metastatic oesophageal carcinoma and warrants additional investigation

    Chemoradiotherapy with or without consolidation chemotherapy using cisplatin and 5-fluorouracil in anal squamous cell carcinoma: long-term results in 31 patients

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    <p>Abstract</p> <p>Background</p> <p>The objectives of this study were to evaluate long-term results of concurrent chemoradiotherapy (CRT) with 5-fluorouracil and cisplatin and the potential benefit of consolidation chemotherapy in patients with anal squamous cell carcinoma (ASCC).</p> <p>Methods</p> <p>Between January 1995 and February 2006, 31 patients with ASCC were treated with CRT. Radiotherapy was administered at 45 Gy over 5 weeks, followed by a boost of 9 Gy to complete or partial responders. Chemotherapy consisted of 5-fluorouracil (750 or 1,000 mg/m<sup>2</sup>) daily on days 1 to 5 and days 29 to 33; and, cisplatin (75 or 100 mg/m<sup>2</sup>) on day 2 and day 30. Twelve patients had T3–4 disease, whereas 18 patients presented with lymphadenopathy. Twenty-one (67.7%) received consolidation chemotherapy with the same doses of 5-fluorouracil and cisplatin, repeated every 4 weeks for maximum 4 cycles.</p> <p>Results</p> <p>Nineteen patients (90.5%) completed all four courses of consolidation chemotherapy. After CRT, 28 patients showed complete responses, while 3 showed partial responses. After a median follow-up period of 72 months, the 5-year overall, disease-free, and colostomy-free survival rates were 84.7%, 82.9% and 96.6%, demonstrating that CRT with 5-fluorouracil and cisplatin yields a good outcome in terms of survival and sphincter preservation. No differences in 5-year OS and DFS rates between patients treated with CRT alone and CRT with consolidation chemotherapy was observed.</p> <p>Conclusion</p> <p>our study shows that CRT with 5-FU and cisplatin, with or without consolidation chemotherapy, was well tolerated and proved highly encouraging in terms of long-term survival and the preservation of anal function in ASCC. Further trials with a larger patient population are warranted in order to evaluate the potential role of consolidation chemotherapy.</p

    Comprehensive in vitro and in vivo studies of novel melt-derived Nb-substituted 45S5 bioglass reveal its enhanced bioactive properties for bone healing

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    The present work presents and discusses the results of a comprehensive study on the bioactive properties of Nb-substituted silicate glass derived from 45S5 bioglass. In vitro and in vivo experiments were performed. We undertook three different types of in vitro analyses: (i) investigation of the kinetics of chemical reactivity and the bioactivity of Nb-substituted glass in simulated body fluid (SBF) by 31P MASNMR spectroscopy, (ii) determination of ionic leaching profiles in buffered solution by inductively coupled plasma optical emission spectrometry (ICP-OES), and (iii) assessment of the compatibility and osteogenic differentiation of human embryonic stem cells (hESCs) treated with dissolution products of different compositions of Nb-substituted glass. The results revealed that Nb-substituted glass is not toxic to hESCs. Moreover, adding up to 1.3 mol% of Nb2O5 to 45S5 bioglass significantly enhanced its osteogenic capacity. For the in vivo experiments, trial glass rods were implanted into circular defects in rat tibia in order to evaluate their biocompatibility and bioactivity. Results showed all Nb-containing glass was biocompatible and that the addition of 1.3 mol% of Nb2O5, replacing phosphorous, increases the osteostimulation of bioglass. Therefore, these results support the assertion that Nb-substituted glass is suitable for biomedical applications
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