188 research outputs found

    Effects of rf breakdown on the beam in the Compact Linear Collider prototype accelerator structure

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    Understanding the effects of RF breakdown in high-gradient accelerator structures on the accelerated beam is an extremely relevant aspect in the development of the Compact Linear Collider (CLIC) and is one of the main issues addressed at the Two-beam Test Stand at the CLIC Test Facility 3 at CERN. During a RF breakdown large electro-magnetic fields are generated and produce parasitic magnetic fields which interact with the accelerated beam affecting its orbit and energy. We discuss here measurements of such effects observed on an electron beam accelerated in a CLIC prototype structure. Measurements of the trajectory of bunch-trains on a nanosecond time-scale showed fast changes in correspondence of breakdown which we compare with measurements of the relative beam spots on a scintillating screen. We identify different breakdown scenarios for which we offer an explanation based also on measurements of the power at the input and output ports of the accelerator structure. Finally we present the distribution of the magnitude of the observed changes in the beam orbit and we discuss its correlation with RF power and breakdown location in the accelerator structure.Comment: 10 pages, 8 figures. We replace the previous version of the article with this one, in which we extend our discussion on the experimental set-up and on the interpretation of our measurements, on the basis of the inputs received during the review process for publication on Phys. Rev. Special Topics - Accelerators and Beams. The essence of our conclusions remain unchange

    PRELIMINARY TAKE-OFF ANALYSIS AND SIMULATION FOR A PRANDTLPLANE COMMERCIAL AIRCRAFT

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    The paper describes the take-off performances and characteristics of an unconventional aircraft, called PrandtlPlane. The PrandtlPlane has a box-wing architecture, founded on the “Best Wing System” concept due to L. Prandtl, that minimizes the induced drag once wingspan and lift are given. This configuration has the potential to be a more efficient alternative to conventional tube-and-wing aircraft, and it is under investigation in the framework of the PARSIFAL project, funded by the European Union in the Horizon 2020 program. A numerical simulation tool for the take-off dynamics of the aircraft, based on the non-linear equations of motion, has been developed in order to evaluate the performance of the aircraft in take-off condition. The VLM solver has been integrated into this tool in order to evaluate the aerodynamic performance of the aircraft in ground effect at each moment of the manoeuvre. The same assessments have been made for a conventional tube-and-wing reference aircraft, with the aim of conducting a performance comparison with the reference PrandtlPlane. The preliminary results obtained show the aerodynamic and aeromechanical advantages of the reference PrandtlPlane, in terms of runway length and passenger comfort

    Ovarian cancer metastasis to the breast: a case report and review of the literature

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    Although ovarian cancer often presents as a widespread disease, metastases to the breast and/or axillary lymph nodes are a very rare event, accounting for only 0.03-0.6% of all breast cancers. Its early recognition and accurate distinction from primary breast cancer are of crucial importance to choose an adequate systemic therapy over unnecessary surgeries. We presented the case of a 53-year-old woman who was diagnosed with breast metastases 2 years after the diagnosis of advanced primary serous ovarian cancer. The patient underwent primary cytoreductive surgery and platinum-based chemotherapy in combination with bevacizumab, followed by bevacizumab maintenance for 18 months. After 2 years of negative follow-ups, the disease unexpectedly spread to the left breast and axillary lymph nodes. No axillary lymph node dissection or breast surgery was performed. The patient received axillary radiotherapy and multiple chemotherapy lines: gemcitabine/cisplatin, liposomal doxorubicin, topotecan, olaparib/cediranib, paclitaxel, and cisplatin. Unfortunately, none of these treatments improved her prognosis and she died 3 years after the disease recurrence. Ovarian cancer metastasis to the breast reveals a disseminated disease with a poor prognosis. Currently, no valid treatment options are available as the disease shows multidrug chemoresistance. In the era of precision medicine, the characterization of genetic and molecular markers may play a role in offering new promising targeted therapies

    Tumor infiltrating lymphocytes in ovarian cancer.

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    Several improvements in ovarian cancer treatment have been achieved in recent years, both in surgery and in combination chemotherapy with targeting. However, ovarian tumors remain the women's cancers with highest mortality rates. In this scenario, a pivotal role has been endorsed to the immunological environment and to the immunological mechanisms involved in ovarian cancer behavior. Recent evidence suggests a loss of the critical balance between immune-activating and immune-suppressing mechanisms when oncogenesis and cancer progression occur. Ovarian cancer generates a mechanism to escape the immune system by producing a highly suppressive environment. Immune-activated tumor infiltrating lymphocytes (TILs) in ovarian tumor tissue testify that the immune system is the trigger in this neoplasm. The TIL mileau has been demonstrated to be associated with better prognosis, more chemosensitivity, and more cases of optimal residual tumor achieved during primary cytoreduction. Nowadays, scientists are focusing attention on new immunologically effective tumor biomarkers in order to optimize selection of patients for recruitment in clinical trials and to identify relationships of these biomarkers with responses to immunotherapeutics. Assessing this point of view, TILs might be considered as a potent predictive immunotherapy biomarker

    RF-BREAKDOWN KICKS AT THE CTF3 TWO-BEAM TEST STAND

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    Abstract The measurement of the effects of RF-breakdown on the beam in CLIC prototype accelerator structures is one of the key aspects of the CLIC two-beam acceleration scheme being addressed at the Two-beam Test Stand (TBTS) at CTF3. RF-breakdown can randomly cause energy loss and transverse kicks to the beam. Transverse kicks have been measured by means of a screen intercepting the beam after the accelerator structure. In correspondence of a RFbreakdown we detect a double beam spot which we interpret as a sudden change of the beam trajectory within a single beam pulse. To time-resolve such effect, the TBTS has been equipped with five inductive Beam Position Monitors (BPMs) and a spectrometer line to measure both relative changes of the beam trajectory and energy losses. Here we discuss the methodology used and we present the latest results of such measurements

    Radiofrequency Ablation and Microwave Ablation in Liver Tumors: An Update

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    This article provides an overview of radiofrequency ablation (RFA) and microwave ablation (MWA) for treatment of primary liver tumors and hepatic metastasis. Only studies reporting RFA and MWA safety and efficacy on liver were retained. We found 40 clinical studies that satisfied the inclusion criteria. RFA has become an established treatment modality because of its efficacy, reproducibility, low complication rates, and availability. MWA has several advantages over RFA, which may make it more attractive to treat hepatic tumors. According to the literature, the overall survival, local recurrence, complication rates, disease-free survival, and mortality in patients with hepatocellular carcinoma (HCC) treated with RFA vary between 53.2 \ub1 3.0 months and 66 months, between 59.8% and 63.1%, between 2% and 10.5%, between 22.0 \ub1 2.6 months and 39 months, and between 0% and 1.2%, respectively. According to the literature, overall survival, local recurrence, complication rates, disease-free survival, and mortality in patients with HCC treated with MWA (compared with RFA) vary between 22 months for focal lesion >3 cm (vs. 21 months) and 50 months for focal lesion 643 cm (vs. 27 months), between 5% (vs. 46.6%) and 17.8% (vs. 18.2%), between 2.2% (vs. 0%) and 61.5% (vs. 45.4%), between 14 months (vs. 10.5 months) and 22 months (vs. no data reported), and between 0% (vs. 0%) and 15% (vs. 36%), respectively. According to the literature, the overall survival, local recurrence, complication rates, and mortality in liver metastases patients treated with RFA (vs. MWA) are not statistically different for both the survival times from primary tumor diagnosis and survival times from ablation, between 10% (vs. 6%) and 35.7% (vs. 39.6), between 1.1% (vs. 3.1%) and 24% (vs. 27%), and between 0% (vs. 0%) and 2% (vs. 0.3%). MWA should be considered the technique of choice in selected patients, when the tumor is 653 cm in diameter or is close to large vessels, independent of its size. Implications for Practice: Although technical features of the radiofrequency ablation (RFA) and microwave ablation (MWA) are similar, the differences arise from the physical phenomenon used to generate heat. RFA has become an established treatment modality because of its efficacy, reproducibility, low complication rates, and availability. MWA has several advantages over RFA, which may make it more attractive than RFA to treat hepatic tumors. The benefits of MWA are an improved convection profile, higher constant intratumoral temperatures, faster ablation times, and the ability to use multiple probes to treat multiple lesions simultaneously. MWA should be considered the technique of choice when the tumor is 653 cm in diameter or is close to large vessels, independent of its size

    Influencia de un aditivo no comercial sobre la calidad de los yesos en construcción

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    At the present paper, it shows how has been studied the influence over the quality of a special sort of gypsum, when it has been added as "additive" 0,96% of potasium chlorurus (Kcl), it has been observed the variation on the mechanical proprieties and also over the time of the beginning and end of the set. Also with the use ot a scanner Electronic Microscopic (M.E.B.), it has been observed the results obtained using such additive and it has been made a comparison with the finded values for the standard specimen.En el presente trabajo se ha estudiado la influencia sobre la calidad de un determinado tipo de yeso, al incorporar como "aditivo" 0,96% de cloruro de potasio (KCI), comprobando la variación en el comportamiento mecánico, así como en los tiempos de principio y final de fraguado. También mediante el uso de la Microscopía Electrónica de Barrido (M.E.B.), se han observado los resultados obtenidos al emplear el citado aditivo y se han comparado con los valores encontrados para las probetas patrón

    Thromboelastographic profiles as a tool for thrombotic risk in digestive tract cancer

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    Background: Quantification of the magnitude of thrombotic risk associated with malignancy and with anti-cancer therapy is indispensable to use anticoagulant drugs which selectively interfere with haemostatic mechanisms protecting patients from venous thromboembolism (VTE) and probably from tumor progression. However, none of activation coagulation markers has any predictive value for the occurrence of the thrombotic events in one individual patient. Current clotting methods can’t reveal the overall dynamic clot formation; in contrast thromboelastographic methods specifically assess overall coagulation kinetics and its strength in whole blood. Aim: Objective of study was to evaluate if the activation of coagulation as eventually revealed by ROTEM® thromboelastometry could assess an hypercoagulable state in surgical neoplastic patients. Patients and Methods: Fifty consecutive patients with carcinoma of the digestive tract in preoperative period (23 M, 27 F aging 61.5 (45–79 years) and 147 healthy subjects (71 M, 76 F) were studied. A recent thromboelastometric method based on thrombelastography after Hartert was employed. Measurements were performed on ROTEM Coagulation Analyzer. The continuous coagulation data from 50 min course were transformed into dynamic velocity profiles of WB clot formation. Results: Standard parameters (CT, CFT, MCF) of cancer patients were similar to controls. CT (in cancer patients): females 50 s (38.3–58.7), males 50 s (42–71.2) vs 51 s (42–59), p = 0.1210 / 53 s (42–74.8), p = 0.1975 (in controls). CFT (in cancer patients): females 72 s (32- 92.4), males 80 s (50.2- 128.7) vs 78 s (62–100), p = 0.0128 / 80 s (59–124.4), p = 0.9384 (in controls). MCF (in cancer patients): females 70 mm (59.9–82.5), males 63 mm (56–73.7) vs 69 mm (59–95.8), p = 0.9911 / 69 mm (53.6–90), p = 0.0135 (in controls). Females showed a higher MaxVel when compared to males. The MaxVel was increased in cancer patients: females 19 mm /100 s (14.3–49.5) males 18 mm / 100 s (11–27) vs 15 mm 100 s (11.8–22), p < 0.001 / 13 mm / 100 s (10–21.8), p < 0.001 in controls .The t-MaxVel was shortened in cancer patients: females 65 s (48.6–112.8), males 81 s (50.1–135.9) vs 115 s (56.8–166), p <0.001 / 115 s (59.8–180.8), p = 0.0002 in controls. The AUC was increased in cancer patients: females 6451 mm 100 (5511–8148), males 5984 mm 100 (5119-6899) vs 5778 mm 100 (4998–6655), p < 0.001 / 5662 mm 100 (4704–6385), p = 0.0105. Conclusion: Unlike other assays measuring variations in a single component during coagulation, the thrombelastographic method records a profile of real-time continuous WB clot formation, and may provide extensive informations on haemostasis in neoplastic patients before surgery.Предпосылки исследования количественная оценка риска тромбоза, связанного со злокачественными заболеваниями и противоопухолевой терапией, обязательно включает в себя применение средств-антикоагулянтов, защищающих больного от развития венозной тромбоэмболии (VTE)и возможно п рогрессии заболевания . Тем не менее ни один из маркеров ак- тивации коагуляции не имеет прогностической ценности с точки зрения возможности возникновения тромбоза у каждого отдельно взятого пациента. Современные мето ды оценки свертывания крови не отража ют образование тромба винамике ; наоборот, метод тромбо эластографии дает возможность специфически оценить кинетику свертывания крови целом . Цель: определить, в какой мере активность коагуляции, определяемой методом тромбоэ ластометрии, отражает состояние гиперсвертываемости крови у больных онкологического профиля после хирургического вмешательства. Пациенты и м ды: обследованы 50 больных раком пищ еваритель ного тракта в дооп ерационный п ериод (27 женщин, 23 му жчины, средний возраст 61,5 года (45–79 лет) и 147 здоровых доноров (71 мужчина, 76 женщин). Применяли метод тромбоэластометрии , основанный на тромбоэластографии Гартерта, с использованием анализатора коагуляциифирмыROTEM. Текущие д анные о свертывании за 50 мин измерений представили в виде динамичных профилей вязкости при образовании сгустка крови. Результаты: стандартные параметры (перио д коагуляции (CT), перио д образования сгу стка (CFT), максимал ь ная п лот- ность сгустка (MCF)) больных онкологического п рофиля близки к контроль ным . CT у больных онкологического п рофиля составлял: у женщин — 50 с (38,3–58,7), у му жчин 50 (42–71,2) vs 51 (42–59), p = 0,1210/53 ( 42–74,8 ), p = 0,1975 в контрольной группе . CFT у таких пациентов составлял : у женщин — 72 ( 32–92,4 м жчин – 80 с (50,2–128,7) vs 78 (62–100), p = 0,0128 80 (59–124,4), p = 0,9384 в контрол ьной группе . MCF у больных онкологического п составлял: у женщин — 70 мм (59,9–82,5), у мужчин — 63 мм (56–73,7) vs 69 мм (59–95,8), p = 0,9911 / 69 мм (53,6–90), p = 0,0135 в контрол ьной группе. У женщинпоказатели вязкости крови MaxVel были выше, чем у му жчин . Показатели MaxVel повышены у таких пациентов : у женщин — 19 мм/100 с (14,3–49,5) у му жчин — 18 мм/100 (11–27 ) vs 15 мм / 100 (11,8–22), p < 0,001 / 13 мм / 100 с (10–21,8), p <0,001 в контрол ьной группе. ь t-MaxVel понижен у больных онкологического профиля: у женщин – 65 с (48,6–112,8) , у мужчин – 81 с (50,1–135,9) vs 115 с (56,8–166), p < 0,001 / 115 с (59,8–180,8), p = 0,0002 в контрольной группе. Показатель AUC у повышен у женщин — 6451 мм 100 (5511–8148), у мужчин — 5984 мм 100 (5119–6899) vs 5778 мм 100 (4998–6655), p < 0,001 / 5662 мм 100 (4704–6385), p = 0.0105. Выводы в отличие от других мето дов, измеря ющих вариации отдельных комп онентов системы крови, метод тромбо эластографии отражает текущийп рофиль образования сгу сткав режиме реаль ного времени является информативным споссобом оценки состояния гемостаза у онкологических больных

    Quantitative diffusion and perfusion MRI in the evaluation of endometrial cancer. Validation with histopathological parameters

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    Objectives: To investigate the role of quantitative Magnetic Resonance Imaging (MRI) in preoperative assessment of tumour aggressiveness in patients with endometrial cancer, correlating multiple parameters obtained from diffusion and dynamic contrast-enhanced (DCE) MR sequences with conventional histopathological prognostic factors and inflammatory tumour infiltrate.Methods: Forty-four patients with biopsy-proven endometrial cancer underwent preoperative MR imaging at 3T scanner, including DCE imaging, diffusion-weighted imaging (DWI) and intravoxel incoherent motion imaging (IVIM). Images were analysed on dedicated post-processing workstations and quantitative parameters were extracted: K-trans, K-ep, V-e and AUC from the DCE; ADC from DWI; diffusion D, pseudo diffusion D*, perfusion fraction f from IVIM and tumour volume from DWI. The following histopathological data were obtained after surgery: histological type, grading (G), lympho-vascular invasion (LVI), lymph node status, FIGO stage and inflammatory infiltrate.Results: ADC was significantly higher in endometrioid histology, G1-G2 (low grade), and stage IA. Significantly higher D* were found in endometrioid subptype, negative lymph nodes and stage IA. The absence of LVI is associated with higher f values. K-trans and V-e values were significantly higher in low grade. Higher D*, f and AUC occur with the presence of chronic inflammatory cells, D * was also able to distinguish chronic from mixed type of inflammation. Larger volume was significantly correlated with the presence of mixed-type inflammation, LVI, positive lymph nodes and stage &gt;= IB.Conclusions: Quantitative biomarkers obtained from pre-operative DWI, IVIM and DCE-MR examination are an in vivo representation of the physiological and micro-structural characteristics of endometrial carcinoma allowing to obtain the fundamental parameters for stratification into Risk Classes.Advances in knowledge: Quantitative imaging biomarkers obtained from DWI, DCE and IVIM may improve preoperative prognostic stratification in patients with endometrial cancer leading to a more informed therapeutic choice

    Impact of covid-19 in gynecologic oncology: A nationwide italian survey of the sigo and mito groups

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    Objective: Coronavirus disease 2019 (COVID-19) has caused rapid and drastic changes in cancer management. The Italian Society of Gynecology and Obstetrics (SIGO), and the Multicenter Italian Trials in Ovarian cancer and gynecologic malignancies (MITO) promoted a national survey aiming to evaluate the impact of COVID-19 on clinical activity of gynecologist oncologists and to assess the implementation of containment measures against COVID-19 diffusion. Methods: The survey consisted of a self-administered, anonymous, online questionnaire. The survey was sent via email to all the members of the SIGO, and MITO groups on April 7, 2020, and was closed on April 20, 2020. Results: Overall, 604 participants completed the questionnaire with a response-rate of 70%. The results of this survey suggest that gynecologic oncology units had set a proactive approach to COVID-19 outbreak. Triage methods were adopted in order to minimize in-hospital diffusion of COVID-19. Only 38% of gynecologic surgeons were concerned about COVID-19 outbreak. Although 73% of the participants stated that COVID-19 has not significantly modified their everyday practice, 21% declared a decrease of the use of laparoscopy in favor of open surgery (19%). However, less than 50% of surgeons adopted specific protection against COVID-19. Additionally, responders suggested to delay cancer treatment (10%–15%), and to perform less radical surgical procedures (20%–25%) during COVID-19 pandemic. Conclusions: National guidelines should be implemented to further promote the safety of patients and health care providers. International cooperation is of paramount importance, as heavily affected nations can serve as an example to find out ways to safely preserve clinical activity during the COVID-19 outbreak
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