There is much evidence that microvascular free flaps are successfully used in the reconstruction of the head and neck defects in cancer patients. It has become evident that proportional with ageing population, there is an increase in the number of elderly patients requiring microvascular reconstruction after radical excision of tumors in the head and neck region. The aim of this study is to estimate the correlation between the application of a microvascular free flap for defect reconstruction in elderly patients based on ASA (American Society of Anesthesiology) classification and postoperative surgical and medical morbidity. Study included 31 patients older than 70 years hospitalized in the period from 1996 to 2010 at the Clinic for Maxillofacial Surgery, Zagreb, Croatia. Base of reference for every patient included data about: gender, age, date and length of surgical procedure, basic diagnosis, chronic illneses, ASA (American Society of Anesthesiology) clasiffication, type of surgical procedure, type of microvascular free flap, postoperative complications, length of hospitalization and treatment results. Based on the data analysis it is estimated that morbidity was significantly higher in the number of male patients than the number of female patients (61% : 38.7%). Average age was 76 years and the oldest patient was 87 years old. According to ASA clasiffication patients were mostly ASA III (60,87%) and then ASA II 26.08%. Overall, the success rate of microvascular free flap was 94%. Moreover, postoperative medical complications were in the correlation with ASA status 19.45%. The study shows that the successs rate of microvascular free flap reconstruction of cancer in the head and neck region with elderly patients is directly related to ASA and the length of surgical procedure, as significant predictors in postoperative surgical and medical morbidity.

A mechanisms-based fracture model applicable to a broad class of cemented aggregates and, among them, plastic-bonded explosive (PBX) composites, is presented. The model is calibrated for PBX 9502 using the available experimental data under uniaxial compression and tension gathered at various strain rates and temperatures. We show that the model correctly captures inelastic stress-strain responses prior to the load peak and it predicts the post-critical macro-fracture processes, which result from the growth and coalescence of micro-cracks. In our approach, the fracture zone is embedded into elastic matrix and effectively weakens the material's strength along the plane of the dominant fracture.

In this paper, we have used the Kolmogorov complexity and sample entropy measures to estimate the complexity of the UV-B radiation time series in the Vojvodina region (Serbia) for the period 1990–2007. We have defined the Kolmogorov complexity spectrum and have introduced the Kolmogorov complexity spectrum highest value (KCH). We have established the UV-B radiation time series on the basis of their daily sum (dose) for seven representative places in this region using: (i) measured data, (ii) data calculated via a derived empirical formula and (iii) data obtained by a parametric UV radiation model. We have calculated the Kolmogorov complexity (KC) based on the Lempel–Ziv algorithm (LZA), KCH and sample entropy (SE) values for each time series. We have divided the period 1990–2007 into two subintervals: (i) 1990–1998 and (ii) 1999–2007 and calculated the KC, KCH and SE values for the various time series in these subintervals. It is found that during the period 1999–2007, there is a decrease in the KC, KCH a...