1.1 Stroke According to the World Health Organization (WHO), stroke is defined as the sudden development of focal or global symptoms and signs of disturbance of cerebral function lasting more than 24 hours or leading to death, as a result of the pathological processes of vascular origin (Thorvaldsen et al., 1995). The basic classification of stroke, according to the type of pathological process, is into ischemic stroke, which comprises 70-85%, and hemorrhagic. An ischemic stroke develops due to the inability of supply to brain tissue oxygen and glucose due to occlusion vessel. If the "outbursts" of blood within the brain mass, there is intracerebral hemorrhage, which makes 15-20% of strokes, while the penetration of the blood in the subarachnoid space, usually as a result of aneurysm rupture, leading to a subarachnoid hemorrhage, which makes 5-10% of all strokes. Stroke leads to focal or multifocal neuropsychological disorders. Given that in clinical stroke in the forefront of motor deficits, disturbance of consciousness and disturbance of speech functions, a very common disorder and the function of other organ systems, most of the neuropsychological symptoms are observed after the acute phase when the general and neurological status stabilized, or when we are able to perform certain neuropsychological tests (Dostovic, 2007). Stroke leads to the different degree of physical, cognitive and psychosocial dysfunctioning. The recovery of patients depends on the severity of disability, the rehabilitation program, but also the subsequent maintenance of achieved function, as well as care and support of family and environment.

Percutaneous transthoracic CT guided biopsies of lung lesions; fine needle aspiration biopsy versus core biopsy Background. The purpose of this retrospective study was to compare the results and complication rate in CT guided percutaneous trans-thoracic fine needle aspiration biopsies (FNAB) and core biopsies of lung lesions, and to determine the applicability of these needles. Patients and methods. In 242 patients (166 males; 76 females) with mean age of 58.9 years (13-84 years) CT guided biopsies of lung lesions were performed on dual slice CT equipment. The average diameter of lung lesion was 2.9 cm (1.2-6.3 cm). For FNAB's 20 - 22 G Chiba needles and for core biopsies 14 G biopsy needles were used. The samples were sent for the histological analysis. The cytological or histological results and the eventual complications were compared. Results. FNAB's cytological samples were adequate for definitive diagnosis in 117 patients (79.60 %) and inadequate in 30 patients (20.40 %). Core biopsies samples were adequate in 92 (96.85 %) patients and non-representative (necrotic tissue) in 3 (3.15 %). Pneumothorax as the most frequent complication was detected in 14 (9.7 %) of the patients in the group of FNAB's and in 30 (31.5 %) of the patients with the core biopsy group. Conclusions. The results showed that percutaneous transthoracic CT guided biopsies of lung lesions were an effective and safe procedure in the diagnosis of lung lesions. Core biopsy gives a higher percentage of representative samples than FNAB, and is a preferred method regardless of the higher rate of complications.

Biological materials are often based on simple constituents and grown by the principle of self-assembly under ambient conditions. In particular, biomineralization approaches exploit efficient pathways of inorganic material synthesis. There is still a large gap between the complexity of natural systems and the practical utilization of bioinspired formation mechanisms. Here we describe a simple self-assembly route leading to a CaCO3 microlens array, somewhat reminiscent of the brittlestars' microlenses, with uniform size and focal length, by using a minimum number of components and equipment at ambient conditions. The formation mechanism of the amorphous CaCO3 microlens arrays was elucidated by confocal Raman spectroscopic imaging to be a two-step growth process mediated by the organic surfactant. CaCO3 microlens arrays are easy to fabricate, biocompatible and functional in amorphous or more stable crystalline forms. This shows that advanced optical materials can be generated by a simple mineral precipitation. Biological materials efficiently exploit self-assembly of simple constituents to produce complex functional structures such as optical devices. By controlling organic molecules, Leeet al. show fast two-step self-assembly of CaCO3microlens arrays, reminiscent of their biological counterparts.

Carbonated hydroxyapatite is the mineral found in vertebrate bones and teeth, whereas invertebrates utilize calcium carbonate in their mineralized organs. In particular, stable amorphous calcium carbonate is found in many crustaceans. Here we report on an unusual, crystalline enamel-like apatite layer found in the mandibles of the arthropod Cherax quadricarinatus (freshwater crayfish). Despite their very different thermodynamic stabilities, amorphous calcium carbonate, amorphous calcium phosphate, calcite and fluorapatite coexist in well-defined functional layers in close proximity within the mandible. The softer amorphous minerals are found primarily in the bulk of the mandible whereas apatite, the harder and less soluble mineral, forms a wear-resistant, enamel-like coating of the molar tooth. Our findings suggest a unique case of convergent evolution, where similar functional challenges of mastication led to independent developments of structurally and mechanically similar, apatite-based layers in the teeth of genetically remote phyla: vertebrates and crustaceans. The compositional makeup of skeletons and teeth in invertebrates and vertebrates is generally different. This study examines the material composition and properties of freshwater crayfish mandibles and finds, in an unusual case of convergent evolution, that they are composed of an apatite layer that is similar to mammalian enamel.

ed/Indexed in Science Citation Index Expanded, SCOPUS, EBSCO and INSPEC (Institution of Electrical Engineers)

ed/Indexed in Science Citation Index Expanded, SCOPUS, EBSCO and INSPEC (Institution of Electrical Engineers)