Total knee arthroplasty (TKA) is the most effective therapy for end-stage osteoarthritis. However, similarly as in total hip arthroplasty, the weakest point of TKA is polyethylene liner undergoing wear during the time of service. Polyethylene debris deliberated from damaged surface triggers adverse host response that results in bone resorption and aseptic loosening. The paper presents introduction into a theory of measurement of knee polyethylene liners which is followed by evaluation of their basic characteristics using mechanical contact methods. In addition, gravimetric method is briefly mentioned. and Implantace totální endoprotézy (TEP) kolenního kloubu je nejúčinnějším způsobem terapie pokročilých stadií artrózy kolenního kloubu. Avšak, podobně jako v případě TEP kyčle, je jejím nejslabším místem polyetylenová vložka, která se používáním kloubu progresivně opotřebovává. Přitom vzniká velké množství polyetylenových částic, které vyvolávají agresivní reakci hostitele, v jejímž důsledku dochází k resorpci kosti a aseptickému uvolnění TEP. Článek uvádí mechanickou kontaktní metodu k in vitro měření objemového otěru polyetylenu u TEP kolenního kloubu, zmiňuje se rovněž o gravimetrické metodě. Přehledově jsou zmíněny vlastnosti vložek a obecné požadavky na vhodné měřicí metody.
Water and nitrogen (N) deficiency are two major constraints limiting the yield and quality of many oilseed crops worldwide. This study was designed to assess the response of Camelina sativa (L.) Crantz to the availability of N and water resources on photosynthesis and yield parameters. All the measured variables, which included plant height, root and shoot dry matter, root:shoot ratio, xylem pressure potential (XPP), yield components, photosynthetic parameters, and instantaneous water-use efficiency (WUE) were remarkably influenced by water and nitrogen supply. Net photosynthetic rate (PN) and yield components were significantly decreased more by water deficit than by N deficiency. XPP, stomatal conductance (gs), and intercellular CO2 concentration (C i) decreased substantially as the water deficit increased irrespective of the level of N application. WUE at the high N supply [100 and 150 kg(N) ha-1] dropped in a large degree as the increased water deficit due to a larger decrease in PN than transpiration rate (E). The results of this study suggest that the regulative capacity of N supply on photosynthetic and plant growth response is significantly affected by soil water status and C. sativa is more sensitive to water deficit than N supply. and X. Pan ... [et al.].