21 research outputs found

    Evaluation of ground information with respect to EPB tunnelling for the Thessaloniki metro, Greece

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    Ο Μητροπολιτικός σιδηρόδρομος της Θεσσαλονίκης αποτελείται από δύο παράλληλες σήραγγες διαμέτρου ~6 m και μήκους ~8 km η κάθε μία και περιλαμβάνει 13 σταθμούς. Η γεωλογία του πολεοδομικού συγκροτήματος της Θεσσαλονίκης χαρακτηρίζεται από την παρουσία νεογενών και τεταρτογενών αποθέσεων. Ο κύριος σχηματισμός της περιοχής του έργου είναι μία σειρά πολύ στιφρών έως σκληρών ερυθρών αργίλων ανωμειοκαινικής-πλειοκαινικής ηλικίας. Σχηματισμοί του Τεταρτογενούς που έχουν αποτεθεί πάνω σε αυτές τις αργίλους συνίστανται από αργιλώδεις-ιλυώδεις άμμους ή/και χάλικες. Το πρόγραμμα γεωερευνητικών εργασιών περιελάμβανε έναν σημαντικό αριθμό δειγματοληπτικών γεωτρήσεων, επί τόπου και εργαστηριακών δοκιμών. Τα στοιχεία του γεωερευνητικού προγράμματος αξιολογήθηκαν ώστε να κατανοηθεί καλύτερα το γεωλογικό προσομοίωμα της περιοχής του έργου και να διακριτοποιηθούν ζώνες με βάση τη συμπεριφορά των γεωυλικών κατά τη διάνοιξη της σήραγγας με μηχάνημα ολομέτωπης κοπής (ΤΒΜ). Όσον αφορά το μηχάνημα διάνοιξης, η επιλογή ενός μηχανήματος εδαφικής εξισορροπητικής πίεσης (ΕΡΒΜ) φαίνεται να είναι εύλογη τόσο από πλευράς ευστάθειας όσο και από πλευράς ρυθμού προχώρησης. Η επιλογή αυτή υπαγορεύεται από τα χαρακτηριστικά του εδάφους για την κάλυψη όλων των αντικειμενικών σκοπών όπως ο έλεγχος των καθιζήσεων και εδαφικών μετακινήσεων, η διατήρηση της στάθμης του υπόγειου νερού αλλά και η ικανοποιητική προχώρηση των σηράγγωνThe Thessaloniki Metropolitan Railway comprises two separate ~6 m diameter parallel tunnels with an ~8 km stretch each and 13 stations. The geology of the urban area of Thessaloniki is characterised by the presence of Neogene and Quaternary deposits. The base formation for the project area is a very stiff to hard red clay, dating to Upper Miocene-Pliocene. Upon this formation, Quaternary sediments have been deposited, most of which comprise sand and/or gravel in a clay-silt dominated matrix, covered in places by anthropogenic fill. Ground investigation campaigns incorporated a significant number of sampling boreholes and in situ and laboratory testing. This information was elaborated in order to obtain a better geological understanding and a geotechnical zonation of the ground with respect to mechanized tunnelling. EPB M appears to be the reasonable choice for the project in all aspects of tunnel safety and tunnelling performance. The characteristics and parameters of the soils and the hydrogeological regime directed towards this selection and it is expected that all the objectives, such as settlement and ground movements control, water table level maintenance and adequate performance, will be met by an EPBM provided it is properly operate

    Varieties of developmental dyslexia in Greek children

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    The current study aimed to investigate in a group of nine Greek children with dyslexia (mean age 9.9 years) whether the surface and phonological dyslexia subtypes could be identified. A simple regression was conducted using printed word naming latencies and nonword reading accuracy for 33 typically developing readers. Ninety per cent confidence intervals were established and dyslexic children with datapoints lying outside the confidence intervals were identified. Using this regression-based method three children with the characteristic of phonological dyslexia (poor nonword reading), two with surface dyslexia (slow word naming latencies) and four with a mixed profile (poor nonword reading accuracy and slow word naming latencies) were identified. The children were also assessed in spelling to dictation, phonological ability, rapid naming, visual memory and multi-character processing (letter report). Results revealed that the phonological dyslexia subtype children had difficulties in tasks of phonological ability, and the surface subtype children had difficulties in tasks of multi-character simultaneous processing ability. Dyslexic children with a mixed profile showed deficits in both phonological abilities and multi-character processing. In addition, one child with a mixed profile showed a rapid naming deficit and another showed a difficulty in visual memory for abstract designs. Overall the results confirm that the surface and phonological subtypes of developmental dyslexia can be found in Greek-speaking children. They also indicate that different subtypes are associated with different underlying disorders

    Long-term follow-up of bucket-handle meniscal repairs: chondroprotective effect outweighs high failure risk

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    Purpose: Outcomes after repair of bucket-handle meniscal tears tend to be satisfying in the short-term follow-up. However, the literature is scarce regarding long-term data following repair of bucket-handle meniscal tears. The aim of this study was to assess long-term follow-up outcomes, focusing on knee osteoarthritis (OA) development and failure rate, and determine risk factors associated with failure. Methods: This is a retrospective cohort study, including all patients with bucket-handle tears within 4 mm of the menisco-synovial junction, who underwent meniscal repair, either isolated or combined with anterior cruciate ligament reconstruction (ACLR) between 2004 and 2015. A combination of all-inside, outside-in, and inside-out repair technique was used in all patients. Patients over 40 years old, concomitant multi-ligamentous injuries, and severe cartilage lesions documented intraoperatively were excluded. During the follow-up, a meniscus was considered healed using Barrett’s criteria, while knee OA evaluation was performed according to Kellgren–Lawrence (KL) classification using standing knee radiographs. Patients were assessed preoperatively as well as postoperatively in terms of knee function using International Knee Documentation Committee (IKDC) score, Lysholm score, and Knee injury and Osteoarthritis Outcome Score (KOOS). Results: In total, the inclusion criteria were met by 66 patients. Median age at the time of operation was 21.9 years (13–39). Median follow-up was 114 (62–176) months. Total failure rate was approximately 33% at median time of 19 (6–39) months. Osteoarthritis was statistically significantly more prevalent in patients with failed repairs (mean KL score: 2.09) in comparison to patients with successful repairs (mean KL score: 0.54) p = 0.001. In addition, successful repairs were associated with higher KOOS score as compared with failed repairs (mean ± SD, 89.6 ± 4.6 vs 77.8 ± 4.9 p < 0.001), higher IKDC score (mean ± SD, 88.2 ± 5.1 vs 79.2 ± 5.2 p < 0.001), and Lysholm score (mean ± SD, 90.3 ± 5.3 vs 78.4 ± 7.8 p < 0.001). Patients with medial meniscus repair had 4.8 higher relative likelihood of failure compared to lateral meniscus [p = 0.014, OR = 4.8 (95% Cl 1.2, 18.6)]. Patients over 16 years old had 5.7 higher relative likelihood of failure [p = 0.016, OR = 5.7 (95% Cl 0.04, 0.85)]. Concurrent ACLR did not have a significant effect on the postoperative outcomes. Conclusion: A high rate of clinical failure was observed after meniscal repair of bucket-handle tears. However, successful treatment led to lower rates of knee OA development and better knee function, approximately 10 years postoperatively. Meniscal repair of bucket-handle tears is recommended to improve knee function and prevent knee OA in young patients. Level of evidence: III. © 2021, The Author(s) under exclusive licence to European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA)

    Dose Escalation of Amifostine for Radioprotection During Pelvic Accelerated Radiotherapy

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    Objectives: Experimental data suggest a dose-dependent efficacy of amifostine so that the low overall doses used in clinical trials may have masked the full potential of the drug. In this study, we report our experience with the role of escalated doses of amifostine in the protection of pelvic tissues. Methods: A total of 354 patients with pelvic carcinomas recruited in prospective protocols applying hypofractionated and accelerated radiotherapy (HypoARC) supported with escalated daily doses of amifostine (0, 500, 750, 1000 mg subcutaneously) were analyzed. Conformal pelvic radiation delivered 14 daily fractions of 2.7 Gy within 18 days, whereas booster techniques increased the daily fraction to the target area to 3.4 Gy. Results: Using a dose-individualization algorithm, 55.4% tolerated a daily amifostine dose of 1000 mg (level 3), 15.9% of 750 mg (level 2), and 17.5% of 500 mg (level 1), whereas intolerance induced amifostine interruption in 11.3% of the patients. Early grade 2/3 urinary frequency and dysuria grades 1 to 2 were significantly higher in level 0 patients (P = 0.04 and 0.01, respectively). The dose level (1 to 3) of amifostine did not influence the incidence of frequency/dysurea. Acute diarrhea and proctitis grade 2/3 were significantly lower only in level 3 (P < 0.0001 and 0.03, respectively). Dose level 3 was also linked to reduced incidence of late bladder and intestinal toxicities (P < 0.05). Local control analysis showed no tumor protection effect of amifostine. Conclusions: Higher amifostine doses are tolerable by patients with pelvic malignancies and can better protect pelvic tissues against early and short-term late effects of radiotherapy

    Is locally advanced head-neck cancer one more candidate for accelerated hypofractionation?

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    Background/Aim: Hypofractionated accelerated radiotherapy (HypoAR) is widely applied for the treatment of early laryngeal cancer. Its role in locally advanced head-neck cancer (LA-HNC) is unexplored. Patients and Methods: We present results of a prospective trial on 124 patients with LAHNC, treated with radio-chemotherapy with three different HypoAR fractionations (3.5 Gy/day × 14-15 fractions, 2.7 Gy/day × 20-21 fractions, and 2.5 Gy/day × 21-22 fractions). Results: Protraction of the overall treatment time due to oropharyngeal mucositis was enforced in 18/57 laryngeal, 6/19 nasopharyngeal, and 15/48 cancer patients with other tumors. Regarding late toxicities, laryngeal edema grade 3 was noted in 5/57 patients with laryngeal cancer, while severe dysphagia was noted in 4/124 and tracheoesophageal fistula formation in 1/124 patients. The complete response rates obtained were 73%, 84%, and 67% in patients with laryngeal, nasopharyngeal, and other tumors, respectively. The 3-year locoregional progression-free survival was 58%, 73%, and 55%, respectively. Conclusion: HypoAR chemoradiotherapy is feasible, with acceptable early and late radiotherapy toxicities, response rates and LPFS. © 2021 International Institute of Anticancer Research. All rights reserved

    Is locally advanced head-neck cancer one more candidate for accelerated hypofractionation?

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    Background/Aim: Hypofractionated accelerated radiotherapy (HypoAR) is widely applied for the treatment of early laryngeal cancer. Its role in locally advanced head-neck cancer (LA-HNC) is unexplored. Patients and Methods: We present results of a prospective trial on 124 patients with LAHNC, treated with radio-chemotherapy with three different HypoAR fractionations (3.5 Gy/day × 14-15 fractions, 2.7 Gy/day × 20-21 fractions, and 2.5 Gy/day × 21-22 fractions). Results: Protraction of the overall treatment time due to oropharyngeal mucositis was enforced in 18/57 laryngeal, 6/19 nasopharyngeal, and 15/48 cancer patients with other tumors. Regarding late toxicities, laryngeal edema grade 3 was noted in 5/57 patients with laryngeal cancer, while severe dysphagia was noted in 4/124 and tracheoesophageal fistula formation in 1/124 patients. The complete response rates obtained were 73%, 84%, and 67% in patients with laryngeal, nasopharyngeal, and other tumors, respectively. The 3-year locoregional progression-free survival was 58%, 73%, and 55%, respectively. Conclusion: HypoAR chemoradiotherapy is feasible, with acceptable early and late radiotherapy toxicities, response rates and LPFS. © 2021 International Institute of Anticancer Research. All rights reserved

    Treatment of Low-risk Prostate Cancer with Radical Hypofractionated Accelerated Radiotherapy with Cytoprotection (HypoARC): An Interim Analysis of Toxicity and Efficacy

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    Aim: Radiobiological analysis of clinical data suggests that prostate cancer has a low alpha/beta ratio, implying that large radiotherapy fractions may better control the disease. Acceleration of radiotherapy may be also of importance in a subset of tumors. In this study we assessed the feasibility and efficacy of a highly accelerated and hypofractionated scheme of radiotherapy (HypoARC), for the treatment of localized low risk prostate cancer. Patients and Methods: Fifty-five patients with prostate cancer (T1-2 stage, Gleason score = grade 2. Amifostine significantly protected against chronic frequency (p=0.02). Within a median follow-up of 30 months, one patient (1.8%) experienced a biochemical relapse. Conclusion: HypoARC is feasible and safe for patients with low-risk prostate cancer and, considering also the high efficacy noted, a strong rationale is provided for the further evaluation of HypoARC in randomized trials
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