Here we report a new Schiff base of aminoguanidine and 2,3-dihydroxybenzaldehyde (H2L) and its physicochemical characterization, along with an investigation into its coordination affinities towards ...zinc. By reacting zinc acetate with the chloride salt of the ligand in the MeCN?H2O solution, yellow single-crystals of tetranuclear, centrosymmetric complex, with the formula Zn2(?-L)(?-OAc)22?2MeCN, were obtained. The complex was characterized by IR spectroscopy, conductometry, elemental analysis, and single-crystal X-ray diffraction analysis. Notably, both nitrogen atoms of the aminoguanidine residue coordinate to the same zinc atom, while both deprotonated phenyl oxygen atoms achieve bridging coordination. Furthermore, two acetate anions bridge adjacent zinc atoms in addition to the Schiff base anion. Meaningful insights into the hierarchy and significance of intermolecular interactions within the crystal structure were gained by estimating the energies using the CrystalExplorer model. The calculations revealed that the crystal structure can be classified as a layer type, with notably stronger interactions occurring along the 001 and 011 directions.
Aminoguanidine derivatives are the focus of research because of their various biological activities, such as antiviral, antibacterial, analgesic, antioxidant and anticancer. Their complexes with ...different metals are also examined and many of them show significant biological activity, too. Besides, some of the complexes show good photoluminescent properties and are used for the preparation of photoelectronic devices. Therefore, the synthesis, physicochemical, structural and thermal characterization of the complexes of 2-acetylpyridine- aminoguanidine (L) with copper (II) are described here. Under different reaction conditions, Cu(II) with L gives three complexes of different compositions. By varying the strength of basicity of the deprotonating agent used, it was proven here that the Schiff base given here could be coordinated in neutral or monoanionic form. In the presence of pyridine, a coordination polymer is obtained, while in the presence of ammonia/lithium acetate two different monomeric complexes were crystallised. Their physicochemical and thermal properties, as well as molecular and crystal structure, are determined.
The development of electronic media and changes of the social context in the situation of the global health crisis in the field of education have resulted in an increased interest in digital ...resources, especially in the application of e-books in teaching. Resorting to this book format raises the question of the perspective of its application in the future changed social circumstances. The authors examine (a) the experiences of students of teacher education and pedagogical faculties (N = 394) from four countries of the Western Balkans regarding the use of digital libraries; (b) the anticipated purpose of using e-books upon the completion of their studies; (c) students’ views on the universal values of books, regardless of the format in which they are published. The attitudes of these students regarding the future application of e-books is determined by their open-mindedness relative to the application of modern technologies for educational purposes, experience in using e-books, their views on the purpose of the future application of this type of books, and values regarding different book formats and books in general. The research findings show that future preschool and primary school teachers are characterized by the values that qualify them for an adequate approach to the outcomes of future changes in the development of books and modern education.
Lullaby, as a literary form that is multifunctional for children - in terms of cognitive, emotional and social development, development of speech, perception and attention, stimulating curiosity and ...interest, and developing creativity - is an important element in achieving educational goals in the context of various aspects of child development. In this paper the authors examine the experience of preschool teachers (N = 302) with: (a) the selection of lullabies; (b) the selection of folk and artistic lullabies; (c) opting for vocal, instrumental, i.e., vocal-instrumental lullabies in their work with the youngest children, in order to understand the potential patterns of selection of this particular literary form and to contribute to the methodological education of the preschool teachers. The research results indicate that the selection of the lullabies is not particularly varied, and that preschool teachers more often opt for the authored lullabies, as well as for the titles that are available in a vocal-instrumental form. The empirical findings bring forth the problem of selecting the content for working with the youngest children, i.e., they open the question of the ability of the preschool teachers to mould the children's literary taste, along with the question of the responsibility of methodologists, above all, the creators of educational policies, bearing in mind that according to the latest Preschool Education Program the choice of the content for activities with preschool children entirely rests upon preschool teachers.
The growing body of evidence suggests that atherosclerosis risk factors are important in cognitive decline.
To analyse insulin sensitivity, insulin secretion capacity, plasma insulin, adiponectin and ...lipid levels in normoglycaemic, nonobese patients with Alzheimer's disease (AD) (group A, n=62), mild cognitive impairment (MCI) (group B, n=41), and healthy controls (group C, n=25).
Insulin sensitivity was determined by euglycemic hyperinsulinaemic clamp (M value) and homeostasis model assessment (HOMA-IR), insulin secretion capacity by first-phase insulin response (FPIR), plasma insulin by RIA, adiponectin by ELISA, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglycerides by enzymatic method.
Insulin sensitivity was the lowest in group A (M value: A: 6.2±2.5; B:7.7±2.7; C:8.2±1.5 mg/min/kg, p<0.001; HOMA-IR: A: 4.6±2.2; B: 3.3±1.7; C: 1.5±1.0, p<0.001) as well as FPIR (A:68.9±27.8; B:112.5±47.1; C:147.4±56.0 mU/l, p<0.001). Plasma insulin was higher in group A vs B vs C, while adiponectin was lower in group A vs B vs C. Simultaneously, total and LDL-C were higher and HDL-C levels were lower in groups A and B vs C, with no difference between groups A and B. Triglycerides did not differ between the groups. Binary logistic regression analysis identified only M value, FPIR and plasma insulin as independent predictors of AD and MCI.
These results imply that in AD and MCI insulin resistance with increased plasma insulin and decreased FPIR may be associated with the development of AD and MCI, accompanied with milder influence of low adiponectin levels and atherogenic lipid profile.
The personality of King Milan – his life, reign and his specific character – was very inspirative for many Serbian writers. The subject of this paper are literary works of Vladan Đorđević (novels of ...court life The Calvary and In Front, as well as parts of memoirs The Memories) in whose center is the Serbian king. Writing his works from the position of close and loyal collaborator of King Milan, Đorđević has impressively pictured all the complexity of Serbian ruler’s character. He presented King Milan as vacillating, unpredictable and fainthearted, but still has returned him the dignity of ruler, turning him into a brave officer who helps his own people.
Revolutionary development of the global communication network has also been reflected on the electronic book as the most important product of digitalization, and a significant educational resource in ...the function of providing a stimulating learning environment. The authors examine teachers' experiences (N=1117) (a) in relation to the justification of using electronic books and the attitudes of teachers and students of teacher education and pedagogy faculties (N=214) in relation to (b) the perspective of using different formats of books and (c) the universal values of the book, regardless of the format in which it was published. The research results show that teachers' motivation for using electronic books in teaching is mostly intrinsic; that teachers and future teachers agree in their attitudes regarding the use of electronic and printed books in the context of text media future development, as well as in their attitudes related to the universal values of the book in general, regardless of advantages and disadvantages of the format in which it was designed. The developed critical attitude of teachers and future teachers towards the potential of technological development of the book in the function of active knowledge building is significant from the aspect of the functionality of modern media in the educational context, bearing in mind that the key role in designing the learning process with the use of modern technology actually belongs to the teacher.
Revolutionary development of the global communication network has also been reflected on the electronic book as the most important product of digitalization, and a significant educational resource in ...the function of providing a stimulating learning environment. The authors examine teachers’ experiences (N=1117) (a) in relation to the justification of using electronic books and the attitudes of teachers and students of teacher education and pedagogy faculties (N=214) in relation to (b) the perspective of using different formats of books and (c) the universal values of the book, regardless of the format in which it was published. The research results show that teachers’ motivation for using electronic books in teaching is mostly intrinsic; that teachers and future teachers agree in their attitudes regarding the use of electronic and printed books in the context of text media future development, as well as in their attitudes related to the universal values of the book in general, regardless of advantages and disadvantages of the format in which it was designed. The developed critical attitude of teachers and future teachers towards the potential of technological development of the book in the function of active knowledge building is significant from the aspect of the functionality of modern media in the educational context, bearing in mind that the key role in designing the learning process with the use of modern technology actually belongs to the teacher.
We analyzed (a) insulin sensitivity (IS), (b) plasma insulin (PI), and (c) plasminogen activator inhibitor-1 (PAI-1) in type 2 diabetes (T2D) patients with (group A) and without (group B) ...atherothrombotic ischemic stroke (ATIS), nondiabetics with ATIS (group C), and healthy controls (group D). IS was determined by minimal model (Si). Si was lower in A versus B ( 1.18 ± 0.67 versus 2.82 ± 0.61 min−1/mU/L × 104; P < 0.001 ) and in C versus D ( 3.18 ± 0.93 versus 6.13 ± 1.69 min−1/mU/L × 104; P < 0.001 ). PI and PAI-1 were higher in A versus B (PI: 19.61 ± 4.08 versus 14.91 ± 1.66 mU/L; P < 0.001 , PAI-1: 7.75 ± 1.04 versus 4.57 ± 0.72 mU/L; P < 0.001 ) and in C versus D (PI: 15.14 ± 2.20 versus 7.58 ± 2.05 mU/L; P < 0.001 , PAI-1: 4.78 ± 0.98 versus 3.49 ± 1.04 mU/L; P < 0.001 ). Si correlated with PAI-1 in T2D patients and nondiabetics, albeit stronger in T2D. Binary logistic regression identified insulin, PAI-1, and Si as independent predictors for ATIS in T2D patients and nondiabetics. The results imply that insulin resistance and fasting hyperinsulinemia might exert their atherogenic impact through the impaired fibrinolysis.
BACKGROUND Patients with Huntington disease (HD) develop diabetes mellitus more often than do matched healthy controls. Recent studies in neurodegenerative diseases suggested that insulin resistance ...constitutes a metabolic stressor that interacts with a preexisting neurobiological template to induce a given disorder. OBJECTIVE To investigate possible changes in insulin sensitivity and secretion, major determinants of glucose homeostasis, in a group of consecutive normoglycemic patients with HD. DESIGN Metabolic investigations. PARTICIPANTS Twenty-nine untreated, nondiabetic patients with HD and 22 control participants matched by age, sex, and socioeconomic background. MAIN OUTCOME MEASURES Glucose tolerance, assessed by means of the glucose curve during oral glucose challenge; insulin sensitivity, assessed using homeostasis model assessment and minimal model analysis based on frequent sampling of plasma glucose and plasma insulin during the intravenous glucose tolerance test; and insulin secretion, determined by means of the acute insulin response and the insulinogenic index. RESULTS The evaluation of insulin sensitivity using homeostasis model assessment demonstrated higher homeostasis model assessment insulin resistance indices, and a lower sensitivity index when the minimal model approach was used, in patients with HD compared with controls (P = .03 and P = .003, respectively). In the assessment of early-phase insulin secretion, the acute insulin response and the insulinogenic index were lower in patients with HD compared with controls (P = .02). The number of CAG repeats correlated significantly only with acute insulin response (P = .003). CONCLUSIONS Besides impairment in insulin secretion capacity, a simultaneous decrease in insulin sensitivity, with an increase in the insulin resistance level, was found in normoglycemic patients with HD compared with controls. These data imply that progression of the insulin secretion defect in HD may lead to a failure to compensate for insulin resistance.Arch Neurol. 2008;65(4):476-480-->
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