850 research outputs found

    Radiation-induced anaplastic astrocytoma following treatment of medulloblastoma

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    We hereby report a case of a 10-year-old girl in whom neurosurgery was performed for cerebellar vermis medulloblastoma in April 2000. After resection the patient underwent chemotherapy followed by radiotherapy, receiving 53.07 Gy to posterior fossa and 35.07 Gy to the rest of the craniospinal axis. In 2012, she was diagnosed with anaplastic astrocytoma, which was located within the high-dose region. Surgical resection of the tumour was performed. Postoperatively, the patient received radiation therapy (50.4 Gy) with concurrent temozolomide, followed by 6 cycles of adjuvant temozolomide. Five years after the diagnosis of anaplastic astrocytoma, the patient remains asymptomatic

    MICROSTRUCTURE AND MECHANICAL PROPERTIES OF AMORPHOUS/CRYSTALLINE DUCTILE LIQUID IMMISCIBLE Fe-Si-B-In ALLOY PRODUCED BY TWO-COMPONENT MELT-SPINNING

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    The two-component melt-spun (TCMS) Fe71.25Si9.5B14.25In5 alloy was produced from Fe75Si10B15 and Fe67.5Si9B13.5In10 alloys. The microstructure of the TCMS alloy was investigated by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD). A tensile test of the alloy resulted in a tensile strength of Rm = 1040 MPa, yield strength Re = 919 MPa, total plastic elongation etot = 3.29%, and traces of plastic deformation on the surface of the Fe-Si-B-In TCMS sample. Microstructural analysis of the amorphous/crystalline composite and tensile sample free surface show the reason for the ductility of the sample in relation to the Fe75Si10B15 alloy

    Sterowanie robotem Robin Heart Pelikan z zastosowaniem siłowego sprzężenia zwrotnego = Force Feedback Control System Dedicated for Robin Heart Pelikan

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    Przedmiotem niniejszej pracy jest badanie systemów sterowania robota Robin Heart PVA (ang. Port Vision Able) z zastosowaniem specjalnych mikroczujników siły 3D MEMS. Postawiono trzy różne sposoby wykorzystania opracowywanych czujników: (1) jako czujnik siły wykorzystany jako mikrodżojstik zintegrowany w rękojeścią narzędzia endoskopowego, aby łatwo kontrolować ruch robota wizyjnego podczas pracy chirurga; (2) jako czujnik siły wewnątrz szczęki narzędzia endoskopowego dla dostarczenia informacji zwrotnej do operatora-chirurga, mierząc siłę chwytu; (3) jako czujnik wielowymiarowy dotyku na końcu narzędzia chirurgicznego, co ułatwia badanie palpacyjne do diagnostyki tkanek podczas pracy. Artykuł ten jest studium wykonalności w zakresie proponowanych zastosowań. Model sterowania robota przy użyciu prototypowego czujnika siły 3D został pomyślnie przetestowany w badaniach funkcjonalnych robota. Wstępne badania sensorów wykazały ich przydatność dla sterowania robotem ze sprzężeniem siłowym, aby ocenić stan tkanek oraz do oceny siły docisku chirurgicznego chwytaka. The aim of this work is to investigate the control systems of Robin Heart PVA (Port Vision Able) using special 3D MEMS force microsensors. Three different functions are targeted: (1) micro-joystick actuator to be integrated in the hilt of the laparoscope to easily control robotic movement during operation; (2) force sensor inside the laparoscopic jaw to provide feedback to the surgeon by measuring the grasping strength; (3) 3D force/tactile sensor which facilitates palpation for tissue diagnostics during operation. This paper is a feasibility study regarding these proposed applications. A model of the robot controller using a prototype 3D sensor force has been successfully tested during the study of functional robot. Pre-studies of prototype sensors have demonstrated their usefulness in robot force feedback system to assess the state of tissue and to assess the clamping force the grasper surgical system

    MICROSTRUCTURE AND PHASE COMPOSITION OF THE Ni-Si-B-Ag-BASED PLASMA SPRAY DEPOSIT

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    The aim of this work is to study the possibility of obtaining an amorphous-crystalline composite starting from Ni-Si-B-based powder grade 1559-40 and silver powder. The process of plasma spray deposition was performed on a water-cooled copper substrate. The cooling rate was assessed using a mid-wave infrared MWIR camera. The microstructure of the deposit was studied using scanning electron microscope SEM with an energy dispersive spectrometer EDS. Phase identification was performed using X-ray diffraction XRD. The studies confirmed an amorphous-crystalline microstructure of the deposits. The predominant constituent of the microstructure was amorphous regions enriched in Ni, Si, and B, while the other constituent was Ag-rich crystalline inclusions identified as a face-centered cubic fcc

    Differences in the prognosis of HPV16-positive patients with squamous cell carcinoma of head and neck according to viral load and expression of P16

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    Purpose To evaluate the impact of HPV16 load (VL-the number of virus genome copies per cell) and P16 expression on prognosis of patients with squamous cell carcinomas (SCCs) of head and neck (HN). Materials and methods HPV16 presence was assessed in the group of 109 patients with HNSCCs by quantitative polymerase chain reaction (qPCR). VL (assessed by qPCR) and P16 expression (evaluated by immunohistochemistry) were analysed only in the subgroup of HPV16-positive tumours. These features were correlated with 5-year overall survival (OS) and disease-free survival (DFS). Results HPV16 infection was found in 36 tumours (33.0%). Virus-positive patients had better OS and DFS than those without infection (P = 0.041 and 0.005). Among HPV16-positive HNSCCs, 18 (50.0%) had higher VL (median value > 6764.3 copies/cell) and 25 (73.5%) P16 over expression. The significant differences in OS and DFS (P = 0.008 and 0.004) were noticed according to VL, wherein 100% DFS was found for patients with higher VL. According to P16 expression, significant difference was found only for OS (P = 0.020). In multivariate analysis, VL (P = 0.045; HR = 2.795; CI 0.121-1.060) and the level of smoking (P = 0.023, HR = 2.253; CI 1.124-4.514) were independent factors affecting DFS of HPV16-positive patients. Conclusion On the basis of viral load, it is possible to differentiate prognosis of patients with HPV16-positive HNSCCs. In this subgroup, viral load has stronger prognostic potential than P16 expression

    Kontrowersje w postępowaniu z chorymi na nasieniaka jądra w I stopniu zaawansowania klinicznego

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    Osiemdziesiąt procent nasieniaków sklasyfikowanych jest w I stopniu zaawansowania klinicznego, stanowiąc około40% wszystkich guzów jądra. Postępowanie z tą grupą chorych po pierwotnym leczeniu polegającym na orchiektomiijest przedmiotem kontrowersji. Rozpatrywane są trzy opcje: obserwacja, radioterapia oraz chemioterapia.Aktywna obserwacja z leczeniem wdrażanym w przypadku wznowy, uzupełniające napromienianie lub adiuwantowamonochemioterapia karboplatyną pozwalają na uzyskanie około 100% przeżyć całkowitych i są alternatywnymi,równoważnymi metodami postępowania. Na podstawie aktualnych danych z literatury przedstawiono zalety i wadykażdej z trzech omawianych opcji

    Bcr-Abl Amplification Plays a Major Role in Resistance to Tyrosine Kinase Inhibitors in K-562 Cell Line

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    An emerging problem in patients with chronic myeloid leukemia (CML) is increasing resistance to tyrosine kinase inhibitors (TKIs). To determine genetic and cellular mechanisms involved in the development of resistance to TKIs, nine imatinib-resistant cell lines were derived from K- 562 cell line followed by testing of drug sensitivity, multidrug resistance proteins and cytogenetic studies. In imatinib-resistant cell lines cross-resistance to daunorubicin, etoposide and cytarabine were observed whereas sensitivity to dasatinib, nilotinib, cyclophpsphamide, bortezomib and busulfan was preserved. Treatment with imatinib decreased PGP and LRP expression, however it did not significantly influence MRP1 expression. Amount of signals in FISH analysis from ABL, BCR and from fusion genes (BCR-ABL or ABL-BCR) was mostly higher in imatinib-resistant cell lines in comparison to parental K-562 cell line. We concluded that BCR-ABL amplification but not cellular sensitivity is the major mechanisms of resistance in K-562 cell line.Narastająca oporność na inhibitory kinazy tyrozynowej (TKIs) jest niepokojącym problemem u pacjentów z przewlekłą białaczka szpikową (CML). Aby określić genetyczne i komórkowe mechanizmy oporności na TKIs z linii K-562 wyhodowano 9 opornych na imatynib linii komórkowych, w których przeprowadzono badania: oporności na leki, ekspresji białek oporności komórkowej oraz badania cytogenetyczne. W opornych na imatinib liniach komórkowych stwierdzono krzyżową oporność na daunorubicynę, etopozyd i cytarabinę, podczas gdy wrażliwość na dasatinib, nilotinib, cyklofosfamid, bortezomib i busulfan była zachowana. Hodowla z imatinibem zmniejszała ekspresję białka PGP i LRP ale nie wypływała na ekspresję białka MRP1. W badaniu metodą FISH w liniach opornych na imatinib w porównaniu do macierzystej linii K-562 obserwowano większą ilość sygnałów pochodzących od genów ABL, BCR oraz od genów fuzyjnych (BCR-ABL i ABL-BCR). Przeprowadzone badania wskazują, że nie mechanizmy oporności komórkowej ale amplifikacja sekwencji BCR-ABL, jest głównym mechanizmem oporności na TKIs w linii K-562

    Effect of Variable-Intensity Running Training and Circuit Training on Selected Physiological Parameters of Soccer Players

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    Proper planning of the training process based on individual LT and AT metabolic thresholds is essential to improve athletic performance. Development of endurance in soccer players is mainly based on continuous runs and variable-intensity runs, supplemented with strength conditioning and sport-specific training. The aim of the study was to analyse selected parameters of physical capacity of soccer players after 8-week variable-intensity running training and circuit training. The experiment was carried out in a group of 34 soccer players aged 21 to 26 years. The athletes were divided into two groups: 17 people in the experimental group and 17 people in the control group. The experimental group was involved in 30-minute tempo runs two times a week for 8 weeks with variable intensity at AT. In the same period, the control group performed two 60-minute continuous runs at the intensity of 70-75%HRmax. The determination of metabolic thresholds used two indirect tests: the multistage shuttle run test (beep test) and maximal lactate steady state test (MLSS) with author's own modification. In order to evaluate maximal heart rate (HRmax), the research procedure was started from the beep test (distance: 20 m). The speed at the first level was 8.5 km/h and increased with each level by 0.5 km/h. Training of the experimental group where variable exercise intensity was used caused a statistically significant increase in HRmax (by 1.9%) and blood lactate levels at the AT (by 20.5%). The training in the experimental group led to the statistically significant (p < 0.05) increase in the parameters of the following variables: HRmax (by 1.9%); lactate level (by 7.85); HR at the AT (by 1,9%); lactate level at the AT (by 20.5%). The assumptions of the experimental training did not cause statistically significant changes in pretest vs. posttest HRmax and blood lactate levels for the LT. Endurance training with high intensity is more effective in soccer players compared to training with moderate intensity. Development of special endurance in soccer should also assume the intensity and method of working similar to the method used during sport competition
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