Medical Aspects of Nanomaterial Toxicity

Nanosilver is the most popular and most studied nanomaterial, however, a family of nanomaterials is rapidly enlarging. They are used in various branches of industry and everyday life. In medicine new nanomaterials can be used either alone or in combination with other “classical” drugs, e.g. cytostatic drugs or antibiotics. They can be also used as diagnostic agents. A development of nanoparticles has led to a new combination of diagnostic and therapy - theranostic. Size of a particle makes a difference not only between bulk material and nanomaterial, but also in their properties and toxicity. Nanomaterials can have beneficial properties, but can also be toxic. New issues concerning nanomaterials arise - an industrial exposure and environmental pollution. They can enter human body in various ways. Cellular mechanisms of nanomaterial toxicity comprise mainly a generation of reactive oxygen species and genotoxicity. The differences between toxicity of fine particles and nanoparticles have led to an origin of a new branch of science, nanotoxicology

PENGARUH MODEL TALKING STICK TERHADAP HASIL BELAJAR IPS SISWA KELAS III

AbstractThe influence of Talking Stick on the results of the study in Social Subject in the third grade students The purpose of this study is to describe how effective the use of stick talking to the results of learning in social class. This research is an experimental research in the form of experimental non experimental experimental group design. The sample of this research is third grade students consisting of 60 students and divided by 30 control class students and 30 students of experiment class. Data collection techniques used are measurement techniques and data collection tool test. Based on statistical calculation the mean of post test of control class is 66,1 and experiment class is 70,7. Result of hypothesis used t test with t count = 1,7168 and ttabel = 1,6723. Then Ha accepted. From these results, the efeect size is 0.45 and categorized as moderate. Based on the above findings, it can be concluded that there is influence Talking Stick on the results of the Study on Social Subjects third class SDN 34 Pontianak City with category medium.  Keywords: Influence, Model Talking Stick, Learning Outcome

Evaluation of subarachnoid space and subarachnoid cisterns in children and teenagers based on computed tomography studies

Purpose: The aim of the study was to develop the normative values of linear indices to the diagnosis of changes in size of the subarachnoid space. Material and methods: Retrospective studies were conducted based on 507 head computed tomography (CT) examinations in children from 0-18 years of age. In total 381 tests were selected for correct reference values. Patients were divided into age groups. For each group, linear indices were calculated, taking into account the size of the fluid spaces in relation to the size of the skull and then the mean with standard deviation, median, as well as 10th and 90th percentile were calculated. The range between the 10th and the 90th percentiles was defined as the reference value. Results: Obtained normative values, minimum and maximum for all groups: index of basal cistern size to the size of the skull - 0.129-0.197; index of basal cistern transverse dimension to the size of the skull - 0.173-0.255; index of basal cistern sagittal dimension to the size of the skull - 0.086-0.150; index of prepontine cistern - 0.034-0.067; index of interhemispheric fissure width - 0.044-0.127; index of Sylvian fissure - 0.036-0.085; index of insular cistern width - 0.020-0.074; index of subarachnoid space - 0.017-0.081. Conclusions: The linear indices can be calculated based on images achieved during routine CT examination. The reference values allow us to determine if the size of the subarachnoid space is within the normal range for a given age group. The results from the oldest age group can also be referred to the adults. Key words: external hydrocephalus, subarachnoid space, computed tomography (CT), linear indices, infants and children

Structure and properties of slow-resorbing nanofibers obtained by (co-axial) electrospinning as tissue scaffolds in regenerative medicine

With the rapid advancement of regenerative medicine technologies, there is an urgent need for the development of new, cell-friendly techniques for obtaining nanofibers—the raw material for an artificial extracellular matrix production. We investigated the structure and properties of PCL10 nanofibers, PCL5/PCL10 core-shell type nanofibers, as well as PCL5/PCLAg nanofibres prepared by electrospinning. For the production of the fiber variants, a 5–10% solution of polycaprolactone (PCL) (Mw = 70,000–90,000), dissolved in a mixture of formic acid and acetic acid at a ratio of 70:30 m/m was used. In order to obtain fibers containing PCLAg 1% of silver nanoparticles was added. The electrospin was conducted using the above-described solutions at the electrostatic field. The subsequent bio-analysis shows that synthesis of core-shell nanofibers PCL5/PCL10, and the silver-doped variant nanofiber core shell PCL5/PCLAg, by using organic acids as solvents, is a robust technique. Furthermore, the incorporation of silver nanoparticles into PCL5/PCLAg makes such nanofibers toxic to model microbes without compromising its biocompatibility. Nanofibers obtained such way may then be used in regenerative medicine, for the preparation of extracellular scaffolds: (i) for controlled bone regeneration due to the long decay time of the PCL, (ii) as bioscaffolds for generation of other types of artificial tissues, (iii) and as carriers of nanocapsules for local drug delivery. Furthermore, the used solvents are significantly less toxic than the solvents for polycaprolactone currently commonly used in electrospin, like for example chloroform (CHCl3), methanol (CH3OH), dimethylformamide (C3H7NO) or tetrahydrofuran (C4H8O), hence the presented here electrospin technique may allow for the production of multilayer nanofibres more suitable for the use in medical field

Would you donate your body? Attitudes of students of nursing and physiotherapy towards body donation for educational and scientific purposes

Background: Human body is the most perfect atlas of human anatomy. Body donation after death is, next to donation of organs for the purpose of transplantation, another most altruistic act, which significantly influences the future of medicine, as regards teaching of anatomy and clinical disciplines. Because students are mainly the beneficiaries of corpse donations, it appears important to learn about their attitudes to this altruistic act. The purpose was to assess the awareness and attitudes of students of nursing and physiotherapy towards body donation for educational and scientific purposes. Materials and methods: A total of 128 Polish students (110 women and 18 men) from the faculties of nursing and physiotherapy of the Medical University of Silesia in Katowice, Poland took part in the questionnaire study. The average age in respective groups was 19.94±0.34 years of age in case of nursing and 19.93±0.25 years of age in case of physiotherapy. The first part of the proprietary questionnaire concerned classes in body dissection conducted in prosectorium and their significance for teaching anatomy. The second part applied to the program of Conscious Body Donation, attitudes towards the body in prosectorium and the approach to body donation for educational and scientific purposes. Results: The results of the study indicate that students from both faculties are in favor of body donation after death for educational and scientific purposes. Unfortunately, only a small percentage of them expressed the willingness to become body donators. The main reasons for the reluctance to do so included psychological barrier and concern for the family. Conclusions: Most of students who responded to the questionnaire support the idea of body donation for educational and scientific purposes after death, yet they appear to be more willing to donate their organs for transplantation than their bodies for educational or scientific purposes after death. There are numerous factors which influence students’ attitude to body donation. More emphasis should be put on educating students, which could contribute to changing their attitude toward that altruistic act, and in consequence may increase the number of donors in the future

Correlations between selected parameters of nasal cavity in neonates and young infants — computed tomography study

  Background: Correlations between selected metric parameters of the nasal cavity and nasopharynx in children without atresia may be useful for anticipating probable dimensions of this region in living subjects, in terms of changes with age. Materials and methods: One hundred and eighty children, age range 0–3 years, were divided into five age groups, and measurements of 18 distances between structures of nasal cavity and nosopharynx were performed on computed tomography scans. Correlation coefficients and relations between parameters have been determined. Results: Our study confirmed the existence of statistically significant correlations between linear dimensions within nasal cavity in children. The analysis demon­strated that for the values of following indexes: nasal septum length/piriform aperture width, and maximum length of the nasal septum/posterior nares width no statistically significant differences have been noted between age groups of children. All correlations have been positive. No statistically significant differences have been noted between the maximum width of the vomer and osseous parameters measured, both in the anterior and posterior part of the nasal cavity, and nasal septum length. Conclusions: The size of posterior nares changed with age in children by a constant value. So far, no such an analysis has been carried out assessing potential correlations between linear dimensions for the entire nasal cavity, nasopharynx, length of the nasal septum in children, as well as proportions of individual linear dimensions of the anatomical structures analysed, in various age groups

A preliminary assessment of soil sulphur contamination and vegetations the vicinity of former boreholes on the afforested post-mine site Jeziórko

The work aims to assess soil sulfur contamination degree indicating various reclamation efficiencies within microhabitats formed in the “Jeziorko” inoperative boreholes of former sulfur-mining areas which have been reclaimed to forest. Three plot categories have been initially determined in post-mining areas: category D – degraded, i.e. ineffectively reclaimed and unsuccessfully afforested plots, pine stands category (P), and birch stands (B), successfully afforestated. Afterwards, four circular plots were defined within each of the determined categories (4 replications, i.e. a total of 12 plots). For each plot, cover-abundance (according to the Braun-Blanquet scale) and dominant herbaceous vegetation species, tree species and stand density were determined. Height (Ht) and diameter at breast height (DBH) measurements were taken, and a vitality assessment was completed according to the IUFRO classification. Soil samples were collected at each plot from the plots in 5 points at two different depths (0–5 cm and 5–40 cm) and laboratory analysis were prepared. Soil  properties such as texture, pH, electrical  conductivity (EC), hydrolytic acidity (Hh), the contents of soil organic carbon SOC, total nitrogen TN, total sulfur TS, and exchangeable cations (Ca2+, Mg2+, K+, Na+) were determined. Soils from the D plot category were characterised by high sulfur contamination, excess salinity (EC), and strong acidity in top soil. These parameters indicated the completed neutralization had not been performed effectively at certain sites. Pine (P) and birch (B) stands categories showed good growth rates and soil parameters indicating the reclamation treatments  had been completed successfully.The work aims to assess the degree of soil sulphur contamination of the various abandoned reclamation efficiencies, within the microhabitats formed in the “Jeziórko” inoperative boreholes of former sulphur-mining areas. These areas have been reclaimed to the forest. Three plot categories were initially determined in the post-mining areas: category D – degraded, i.e. ineffectively reclaimed and unsuccessfully afforested plots, with low cover-abundance or complete lack of vegetation, pine stands category, category (P) - birch stands and category (B)- successfully afforested. Afterwards, four circular plots were defined within each of the determined categories (4 replications, i.e. a total of 12 plots). For each plot, cover-abundance (according to the Braun-Blanquet scale) and dominant herbaceous vegetation species, tree species and stand density were determined. Height (Ht) and diameter at breast height (DBH) measurements were taken, and a vitality assessment was completed, according to the IUFRO classification. Soil samples were collected at each plot, in 5 points, at two different depths (0–5 cm and 5–40 cm). Finally, laboratory analysis was undertaken. Soil properties such as texture, pH, electrical  conductivity (EC), hydrolytic acidity (Hh), the contents of soil organic carbon SOC, total nitrogen TN, total sulphur TS, and exchangeable cations (Ca2+, Mg2+, K+, Na+) were determined. Soils from the D plot category were characterised by high sulphur contamination, excess salinity (EC) and strong acidity in top soil. These parameters indicated that completed neutralization was not performed effectively at certain sites. Pine (P) and birch (B) stands categories showed good growth rates and soil parameters, indicating that the reclamation treatments were completed successfully

The comparison of multipotential for differentiation of progenitor mesenchymal-like stem cells obtained from livers of young and old rats.

The presence of stem cells differentiating to hepatocytes and cholangiocytes has been previously reported in livers of young rats. Here, we have isolated, cultured, and characterized mesenchymal stem cells (MSCs) from livers of young and old rats and tested their multipotential for differentiation. The mesenchymal stem cells in liver sections were identified by the presence of markers, respectively for primary stem cells Thy-1 and CD34, for differentiation to early cholangiocytes GST and CK19, and for differentiation to hepatocytes GSTalpha and CK18. Ki67 was detected as the cell proliferation marker. Cells isolated from livers of either age group were tested in a culture for their viability following storage and were characterized for the presence of most of the markers detected in cells in situ. The results revealed age-dependent changes in the number of recovered primary MSCs. In both age groups we have observed cells changing under differentiating conditions to liver cell lineages, such as cholangiocytes and hepatocytes, as well as to non-liver cells such as adipocytes, astrocytes, neuroblasts, and osteoblasts. Our data revealed that from the livers of rats 20 months and older the primary MSCs could be isolated and expanded; however, they were significantly fewer, even though their differentiation multipotential was preserved. The mechanism involved in the differentiation of liver MSCs seemed to depend on a constellation of signals in Notch signalling pathways. Thus, our results support the idea of potential use of liver as a source of MSCs, not only for liver reconstruction but also for cell therapy in general