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One of the most exploited approaches in scientific methodology is studying concepts by using a case study. In chemistry, a case study appears in finding a specific molecular and/or reaction system by which the investigated problem can be observed directly "on substance". Thus, the stu- died problem becomes a concrete system, rather than an abstract concept. Most case-study models are designed specifically to deepen one or another chemical problem. However, there exist (although rarely) models, which afford their universality, i.e. could serve for modeling of qui- te different, and even epistemologically independent concepts. Systematic investigations of the chemistry of C-nitroso compounds performed in our Laboratory in last few years, have resulted in the discovery that such molecular system may be used as a model for studying a series of basic chemical concepts; selectivity, self-assembly, solid-state reaction mechanisms, photochromism and molecular logics. Since it is known that C-nitroso compounds under specific conditions dime- rize by forming new N=N bond (Scheme 1), the reaction can be used for studying selectivity in the formation of dimers between different nitroso monomers (Fig. 1 and Fig. 2). The system is very convenient for investigation of the structure-selectivity relations.6 It has already been established, especially in the work of Brian Gowenlock, that nitroso compounds in crystal form appear as di- mers. These discoveries inspired us to investigate the kinetics and mechanism of dimerization of nitroso monomers in solid state, because the freshly sublimed nitrosoaromatic compounds appear as crystals of monomers. Consequently, this molecular system is a perfect case-study model for concepts of solid-state reactions, self-organizations in the crystalline forms (Fig. 3), as well as for the8,13 Extending our research of self-organization of nitroso compounds to two-dimensional systems (Fig. 4), we have also de- monstrated the ability of such molecules to be models for formation of self-assembly bilayers (Fig. 5), and for direct observations of 2D crystallizations.12 The discovery of photodissociation of crystallized dimers observed by the change in color, also demonstrated that this molecular system could be one of the basic models for molecular logic gates (Fig. 7). 16From the presented examples it follows that this molecular model of dimerizations of aromatic nitroso compounds affords its epistemic universality.

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Chemical characteristics of raw and processed Istarski pršut (PDO) produced from two different pig genotypes were studied with special emphasis on amino and fatty acid composition and factors of lipid stability. Raw hams of Large White (LW)xLandrace (L), and (LWxL)xDuroc (D) pig genotypes were used in the study (20 hams of each genotype). All left raw hams from each carcass were processed in accordance with the PDO specification of Istarski pršut , and other half (the right ones) of LWxL)xD genotype were used for analyses of raw hams (fresh muscles). Istarski pršut was evaluated on the basis of the chemical parameters of the raw and matured lean ham. The process of dry curing significantly influenced the chemical properties of Istarski pršut . Despite the higher content of intramuscular fat and polyunsaturated fatty acids, the fat of (LWxL)xD ham was much more resistant to hydrolysis and oxidation, suggesting that fatty acid profile and other factors, also play a significant role. Significant differences between pig genotypes in the amino acid and fatty acid profiles were found. The analyzed Istarski pršut may be distinguished by prints of multivariate chemometric statistical analysis, based on their amino acid and fatty acid compositions.

Setting: Patients of five randomly selected general practitioners in Split, Croatia., Objective: To investigate knowledge about tuberculosis (TB) and to identify target groups for information, education and communication activities., Design: Cross-sectional survey based on a structured questionnaire using a convenience sampling among subjects aged > or =18 years. Data were stratified by sex, age group, educational background, personal monthly income and contact with TB patients. TB knowledge scores were determined from the number of correct answers to 12 selected questions., Results: The questionnaires were completed by 386 subjects. No statistically significant differences were observed between females and males with respect to age, educational background or contact with TB patients, except for personal income, which was higher in males (P < 0.001). The mean TB knowledge score was 9.4 +/- 1.98 (range 1-12, median 10). A low score was associated with the youngest age group, 18-29 years (P = 0.018), and with <12 years of education (P = 0.002)., Conclusion: Educational background and age groups of respondents were important determinants of TB knowledge. Although the study sample showed a satisfactory level of knowledge, the results demonstrated several misconceptions that need to be clarified. Uncertainties in core TB knowledge need to be addressed choosing less educated and young people as specific target groups.