X-ray micro-CT measurement of large parts at very low temperature.

At present, the automotive industry, along with other industries, has increasing demands on accuracy of produced parts and assemblies. Besides the regular dimensional and geometrical inspection, in some cases, also a verification at very low temperatures is required. X-ray computed tomography (CT), as a tool for non-destructive testing, is able to examine samples and then determine dimensions for strictly stable temperature conditions necessary for the stability of the CT system. Until now, no system that allows scanning of samples larger than a few millimeters at temperatures much below 0 °C has been presented. This paper presents a cooling system for CT imaging of parts with length up to 300 mm at the extreme temperature conditions of -40 °C, which are based on automotive industry requests. It describes the equipment and conditions under which it is possible to achieve a temperature stability of samples at low temperatures, while keeping an independent temperature regulation of the CT system. The presented system uses a standard industrial CT device and a newly designed cooling stage with passive cooling based on phase-change material. The system is demonstrated on the measurement of plastic part (car door handle) at temperatures of -40 °C and 20 °C. The paper also presents the method of how to interpret the thermal changes using tools of the commercial software VGStudio MAX (Volume Graphics GmbH, Germany).

Ultrastructure of Cell Organelles in Pre-implantation Embryos from Cows with Different Body Condition Score.

Morphology of important cell organelles (mitochondria, lipid droplets, vacuoles, inclusion bodies and apoptotic bodies) in embryos derived from cows with different body condition score (BCS) was analysed by transmission electron microscopy (TEM). Embryos were recovered on 7th day after the insemination by a standard non-surgical flushing of the uterine horns from superovulated Holstein Friesian cows with BCS 2, 3, 4 and 5. Thereafter, the good quality blastocysts were processed for TEM. The electronograms were evaluated by stereological analysis. The relative volume of lipid droplets in BCS4 and BCS5 embryos increased significantly (18.53 and 22.40%) when compared to BCS3 embryos (5.46%). In the embryos from the BCS4 or BCS5 cows, we observed different morphological patterns of mitochondria, as well as the mitochondria containing vacuoles. BCS4 and BCS5 embryo cell nuclei showed the structure typical for low transcription activity (none or very few reticular nucleoli); also dilated inter-cellular spaces were often observed in these embryos. In conclusion, differences in the ultrastructural morphology of embryos from over-conditioned cows (BCS4 and BCS5), particularly the higher lipid content in the cytoplasm, can be a marker of their low quality, and this fact can be a contributing factor to subfertility in over-conditioned cows.

Ultrastructure of vitrified rabbit transgenic embryos.

The aim of the study was to determine the viability of rabbit transgenic (enhanced green fluorescent protein (EGFP)-positive) embryos cultured in vitro and compare with gene-microinjected (Mi) non-transgenic (EGFP-negative) embryos following vitrification. Non-microinjected and non-vitrified embryos were used as the control. Morphological signs of injury to embryo organelles were determined at the ultrastructural level using transmission electron microscopy (TEM). Morphometric evaluation was performed on cellular organelles using microphotographs obtained by TEM. Intact and Mi embryos recovered from in vivo fertilized eggs at 19-20 hours post coitum (hpc) were cultured for up to 72 hpc (morula stage), evaluated for the EGFP gene integration and then vitrified in 0.25 ml insemination straws in modified EFS (40% ethylene glycol + 18% Ficoll 70 + 0.3 M sucrose) vitrification solution. After 1-3 days the embryos were devitrified, a representative selection of embryos was analyzed by TEM and the remaining embryos were subjected to additional in vitro culture. Observations by TEM showed that the vitrified/warmed EGFP-positive and EGFP-negative embryos had a slight accumulation of cellular debris and lipid droplets compared with the control intact embryos. More severe changes were detected in the membrane structures of the treated embryos, mostly in the cytoplasmic envelope, trophoblastic microvilli, junctional contacts and mitochondria. We suggest that the higher proportion of deteriorated cell structures and organelles in the treated embryos may be due to the vitrification process rather than to mechanical violation (the gene-microinjection procedure), as a detailed inspection of ultrastructure revealed that most damage occurred in the cell membrane structures.

Incidence of cutaneous malignant melanoma in the Czech Republic: the risks of sun exposure for adolescents.

The Czech Republic reported one of the highest incidence rate in cutaneous melanoma (CM) in Europe and because this incidence has been increasing, mainly among young people, the main goal of our study was to establish sun exposure behavior risk factors for CM formation and to evaluate whether the young generation of Czechs is exposed to a higher risk of CM than the older generation. A questionnaire-based case-control study was conducted. We obtained 978 completed questionnaires: 216 from patients with CM and 762 from healthy respondents. The healthy individuals were further divided to adolescents (n = 460) and older respondents (n = 302). Three logistic regression models were developed: 1. patients with CM vs. healthy older respondents, 2. adolescents vs. healthy older respondents, and 3. patients with CM vs. adolescents. The main risk factors for all three models were the number of sunburn episodes and the use of the sunscreen in the childhood. The most alarming results for adolescents included: all day sun exposure, including times of maximum risk (11 AM to 3 PM), inadequate use of sunscreen in adulthood, and frequent mountain holidays. Our results show that sun-safety in the young generation is satisfactory, when the responsibility for sun exposure behavior is in the hands of their parents; however, when children become adolescents, they become immune to sun-safety and risk prevention campaigns and their behavior becomes much more risky. Our results further suggest the sun-safety campaigns need to be modified in such a way as to have greater impact and influence on adolescent sun-risk behaviors.

Intradermal running suture versus 3M™ Vetbond™ tissue adhesive for wound closure in rodents: a biomechanical and histological study.

BACKGROUND: Although tissue adhesives and traditional sutures were compared in numerous studies during the early stages of healing, it has to be clarified, from the histological and biomechanical point of view, how the differences develop during the later phases. METHODS: Twenty-four male Sprague-Dawley rats were used and divided into 2 groups: the IRS (intradermal running suture) and G (glue) groups. Two parallel full-thickness skin incisions were made on the back of each rat. Wounds in the IRS group were closed by an IRS, whereas wounds in the G group were closed using tissue adhesive (n-butylcyanoacrylate). Rats were sacrificed 7 and 22 days after surgery. RESULTS: Similar wound tensile strengths of glued and sutured wounds were measured on days 7 (IRS = 10.3 ± 1.7 g/mm(2) vs. G = 12.9 ± 4.0 g/mm(2), p = 0.9612) and 22 (IRS = 95.6 ± 15.7 g/mm(2) vs. G = 85.6 ± 16.4 g/mm(2), p = 0.2502) after surgery. Histology revealed a significantly increased amount of granulation tissue formation in glued wounds on day 7. The difference in granulation tissue formation was reduced until day 22. CONCLUSIONS: Tissue adhesive based on n-butylcyanoacrylate presents a fair alternative to traditional suture wound closure techniques.

Simple interrupted percutaneous suture versus intradermal running suture for wound tensile strength measurement in rats: a technical note.

BACKGROUND: In this experimental study, simplicity of measurement and wound tensile strength of wounds fixed by simple interrupted percutaneous suture (SIPS) and intradermal running suture (IRS) were compared. METHODS: Twenty-eight male Sprague-Dawley rats were used for the experiment and separated into two groups: SIPS group and IRS group. Under general anesthesia, two parallel full-thickness (4-cm) skin incisions were made on the back of each rat. Wounds in the SIPS group were closed using 4 interrupted percutaneous sutures, whereas wounds in the IRS group were closed by intradermal running suture. Seven animals from each group were sacrificed at 2 and at 5 days after surgery for tensile strength testing. RESULTS: The wound tensile strength of IRS wounds was significantly higher than that of SIPS wounds at 2 days (SIPS = 2.9 +/- 0.8 vs. IRS = 3.7 +/- 0.9 g/mm(2), p < 0.05) and at 5 days (SIPS = 5.6 +/- 1.3 vs. IRS = 7.1 +/- 1.2 g/mm(2), p < 0.01). In addition, the measurement of IRS wounds was easier and faster due to removal of only one suture. CONCLUSIONS: These findings highlight the advantages of expanding the use of IRS suturing in experimental studies conducted on rats.

[Current trends of the treatment of the femoral neck fractures in seniors]. / Súcasný trend lie'cby zlomenín krcka stehnovej kosti u seniorov.

INTRODUCTION: Proximal femur fracture of the seniors is often "omen" for their life. These fractures are the most frequent cause of acute hospitalization of the aged and on the contrary to previous years the procedures are considered as emergent - life saving. OBJECTIVE: The aim of the study was to find out which of the contemporary used surgical procedures for the treatment of unstable femoral neck fractures at the Department of Trauma Surgery in Kosice yield in the lowest number of failures and postoperative complications. Subsequently we have analyzed changes in surgical treatment of these fractures in two time periods (1999-2001) and (2002-2004) respectively. According to review of the literature and our knowledge we tried to suppose algorithm of their treatment. MATERIAL AND METHODS: There were 563 patients over 65 years were assigned to the retrospective clinical trial. They underwent the internal fixation or arthroplasty for unstable femoral neck fractures between January 1999 and December 2004 and were registered at least one year after the surgery. RESULTS AND CONCLUSION: The results from the clinical trial show that it is more suitable to use internal fixation for biologically younger seniors with fractures of proximal femur. Hemiarthroplasty is indicated for the patients with assumed short-term life expectancy and total hip arthroplasty remains the method of choice for the treatment of the failure of the other surgical procedures. There is decrease of number of implanted hemiarthroplasties in comparison of two analyzed time periods. Moreover, number of treated patients in the later period has increased.

Methodics of IR Imaging in SCI Individuals Rehabilitation.

Temperature is one of the parameters which gives information about some physiological changes in the human body, especially in spinal cord injured (SCI) individuals and their rehabilitation. Exercise induces muscle contraction, and in interactivity with cardiovascular and respiratory system produces heat, which dilates by conduction through the tissue to body surface. In individuals with spinal cord injury (SCI) autonomic disruption, immobility and inactivity play critical roles in affecting peripheral vascular circulation. It is even more important to monitor temperature changes during the physical activity (rehabilitation process) in mentioned group of patients. One of the possible ways how to provide thermometric measurements and evaluation is the use of the infrared (IR) thermography. It is very important to use suitable methodology of measurement. IR imaging can produce reliable and valid results only if the technique follows established standards. Initial thermographic measurements in SCI individuals and able-bodied (AB) during the rehabilitation process were performed.