294 research outputs found
Arthroscopic mosaicplasty for osteochondral lesions of the knee: Computer-assisted navigation versus freehand technique
No full textA palynological survey of the genus Iberis (Brassicaceae), known as candytufts, in Turkey
No full textThe present study reports for the first time detailed palynological traits of the Turkish species Iberis. Both light microscope (LM) and scanning electron microscope (SEM) were used for the characterisation of the species. Radially symmetrical, isopolar, and tricolpate pollen grains were observed as common characters in all of the examined taxa. The pollen grains were prolate-spheroidal with polar axes ranging from 21.97 to 29.25 mu m and equatorial axes ranging from 20.34 to 26.09 mu m. Their polar shapes were subcircular to subtriangular. Two types of exine ornamentation were observed using a SEM. A numerical UPGMA analysis showed that the dimensions of polar axes, equatorial axes and outline in polar view (amb) were the most valuable variables for separating the Iberis species.Financial Unit of Selcuk University [18401063]The author thanks Dr. Huseyin Dural for helping to identify the species, Dr. Tuna Uysal for field excursions for the I. carica samples, Dr. Dilek Oskay for providing the I. saxatilis subsp. magnesiana species samples, and the Financial Unit of Selcuk University for supporting this study (Project no: 18401063). Anna Geraci suggested interesting changes that greatly improved the text, and Manuel B. Crespo made an accurate editing work
Effect of electrolytic nickel coating on fatigue life of iron based P/M parts
No full textElectrolytic coating is one of the methods mainly used to provide corrosion resistance for the powder metal parts. The coatings have strong effects on mechanical properties of coated parts as well as on surface properties. The other factor that affects the mechanical properties of powder metal (P/M) parts is density ratio. In this study the effect of electrolytic coating and density ratio on fatigue life of powder metal iron parts has been investigated. Commercially pure iron powders were pressed under 150, 200 and 250 MPa pressures. Specimens were sintered at 1100 degrees C in flowing argon atmosphere for 45 mm. Some of the specimens were electrolytic nickel coated. Coated and uncoated specimens were fatigued in rotating bending under the same conditions. Also residual stress analysis was carried out on both kinds of specimens. It had been determined that electrolytic nickel coating increased fatigue life of P/M iron parts. It had also been determined that fatigue life increased with density ratio
[A-mode ultrasonic pointer for navigated pelvic surgery]
No full textSurgical navigation has proven to be a minimally invasive procedure that enables precise surgical interventions with reduced exposure to irradiation for patient and personnel. Fluoroscopy-based modules have prevailed on the market. For certain operations of the pelvis computed tomography is necessary with its high imaging quality and considerably larger scan volume. To enable navigation in these cases, matching of the CT data set and the patient's real pelvic bone is essential. The common pair point-matching algorithm is complemented by the surface-matching algorithm to achieve an even higher overall precision of the system. For conventional surface matching with a solid pointer, the bone has to be exposed from soft tissue quite extensively, using a solid pointer. This conflicts with the claim of computer-assisted surgery to be minimally invasive. We integrated an A-mode ultrasonic pointer with the intention to perform extended surface matching on the pelvic bone noninvasively. Related to the conventional method, comparable and to some extent even improved precision conditions could be established
Accuracy of navigated surgery of the pelvis after surface matching with an a-mode ultrasound probe
No full textComputer-aided surgery (CAS) allows for real-time intraoperative feedback resulting in increased accuracy, while reducing intraoperative radiation. CAS is especially useful for the treatment of certain pelvic ring fractures, which necessitate the precise placement of screws. Flouroscopy-based CAS modules have been developed for many orthopedic applications. The integration of the isocentric flouroscope even enables navigation using intraoperatively acquired three-dimensional (3D) data, though the scan volume and imaging quality are limited. Complicated and comprehensive pathologies in regions like the pelvis can necessitate a CT-based navigation system because of its larger field of view. To be accurate, the patient's anatomy must be registered and matched with the virtual object (CT data). The actual precision within the region of interest depends on the area of the bone where surface matching is performed. Conventional surface matching with a solid pointer requires extensive soft tissue dissection. This contradicts the primary purpose of CAS as a minimally invasive alternative to conventional surgical techniques. We therefore integrated an a-mode ultrasound pointer into the process of surface matching for pelvic surgery and compared it to the conventional method. Accuracy measurements were made in two pelvic models: a foam model submerged in water and one with attached porcine muscle tissue. Three different tissue depths were selected based on CT scans of 30 human pelves. The ultrasound pointer allowed for registration of virtually any point on the pelvis. This method of surface matching could be successfully integrated into CAS of the pelvis
Professor Leszek Bednarczuk - about passion for Indo-European languages and the sources of fascination with the Mickiewicz and Vilnius themes
No full textArtykuł prezentuje życiorys naukowy Prof. L. Bednarczuka, wszechstronnego badacza, językoznawcy, indoeuropeisty i celtologa, wieloletniego pracownika naukowego i dydaktycznego Uniwersytetu Pedagogicznego w Krakowie oraz Akademii Polonijnej w Częstochowie, autora licznych prac z zakresu językoznawstwa indoeuropejskiego. W pierwszej części artykułu przedstawiono wspomnienia Profesora z dzieciństwa i lat młodzieńczych, które wywarły znaczący wpływ na wybór ścieżki naukowej. W dalszej części omówiono najważniejsze dzieła naukowe Profesora. W części końcowej zawarto wspomnienia oraz refleksje Prof. L. Bednarczuka, w szczególności na temat roli języka w życiu człowieka.The article presents the scientific biography of Prof. L. Bednarczuk, a versatile researcher, linguist, specialist on Indoeuropean languages, the longtime researcher and lecturer at the Pedagogical University in Krakow and the Polish Academy in Częstochowa, author of numerous works in the field of Indo-European linguistics. The first part of the article presents Professor’s memories from childhood and adolescence, which had a significant impact on the choice of his scientific path. In the following part, the most important scientific works of the Professor are discussed. The final part contains his memories and reflections, in particular on the role of language in human life
Bakterielle Kontamination von Elektrokauterspitzen im Rahmen der Knie- und Hüftendoprothetik
No full textResults of postoperative radiotherapy in the treatment of 29 uterine sarcoma patients
No full textAims and background: The objective of this study was to evaluate the results of surgery combined with postoperative radiotherapy (FIT) in patients with uterine sarcoma in order to describe the patterns of relapse and to define prognostic factors. Methods: We report on 29 patients with uterine sarcoma (US) treated from 1980 to 1995; 18 patients with primary tumors were treated with surgery and adjuvant irradiation, while 11 patients with local recurrences (LR) after previous surgical resection received only radiotherapy. We evaluated the influence of stage, histology, grade, menopausal status, total radiation dose and brachytherapy on survival. Histological diagnosis was leiomyosarcoma in 13 patients (44.8%), endometrial stromal sarcoma in 10 patients (34.5%), and mixed mesodermal tumors in six patients (20.7%). Fifteen patients presented with stage I-II disease, three with stage III, and II with local recurrences. External pelvic RT was administered to all patients, in five patients combined with brachytherapy. The mean total dose was 54 Gy (SE 1.78). Univariate and multivariate analyses were carried out. Results: Overall survival (OS) for the stage I-III group was 61.1% at two years and 33.3% at five years (median 29 months, SE 13.79). Disease-free survival (DFS) was 55.6% at two years and 33.3% at five years. Median DFS was 26 months (SE 14.85). In LR cases, median OS was only 10 months (SE 4.5). Multivariate analysis demonstrated that stage was the only prognostic factor after RT for US. Conclusions: These data suggest that postoperative and/or salvage FIT has a questionable impact on disease-free and overall survival because of the lack of homogeneity of stages in the series reported in the literature; it has, however, acceptable late side effects. Prospective multicenter trials including a statistically evaluable number of patients are necessary to further clarify the role of RT treatment programs for US
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