Defect detection in composite constructions – the proposition of a diagnostic test

Modern racing yachts must have extreme performance and reliability in all conditions. Meeting these demands is possible through the use of new materials. The occurrence of lightweight yet durable Carbon masts allowed to increase their height without having to increase the diameter, thereby reducing the impact of the mast on the change of the speed of flow around and distortion. In addition to the advantages mentioned composite pole has also the characteristics which lead to great difficulties both in the manufacturing process and subsequent operation. There is a real need for a diagnosis of this type of objects, which gives information about any construction defects, and above all the information about damages developing during the operation

Coronary calcium score - a non-invasive method for the detection and quantification of coronary atherosclerosis

Cardiovascular diseases pose a significant medical problem in the developed world. Coronary heart disease (CHD) is the most common of these and is the cause of more than half the cases of heart failure in the general population below 75 years of age. Atherosclerosis lies at the basis of the majority of CHD cases. As the early detection of asymptomatic CHD may lower patient morbidity and mortality, there is an ongoing search for non-invasive diagnostic techniques. Computed tomography, which enables coronary artery calcification to be assessed, is one of these. Examples of the implementation of a calcium score, both in asymptomatic patients and in patients with diagnosed CHD, are presented in this paper

Osseointegration of hydroxyapatite coatings doped with silver nanoparticles: scanning electron microscopy studies on a rabbit model

Background: Modern joint arthroplasties rely on osseointegration of metal components through bone ingrowth into hydroxyapatite (HA) layers. However, such surfaces are prone to colonisation by bacteria and formation of biofilms. Application of silver nanoparticles (SNs) to hydroxyapatite coatings could reduce the risk of infection; however, little is known about how this would affect the process of bone ingrowth. This study examined osseointegration of conventional and SN doped HA coatings in a rabbit model.  Materials and methods: In this study, 12 cylindrical implants coated with conven- tional and SN doped HA were implanted into New Zealand white rabbit femora, with each animal receiving both types of implants. After 12 weeks, rabbits were sacrificed, their femora were harvested and implants removed during pull-out testing. Retrieved samples were dehydrated, sputter coated and observed using a scanning electron microscope (SEM) to verify bony ingrowth and retention of SNs.  Results: The percentage of implant in direct contact with bone was measured in cross-sections of implants. The SEM analysis demonstrated that osseointegration of the SN doped coatings was similar to the conventional HA samples. A similar morphology of newly formed trabecular bone was observed in both implants, with silver doped HA-coated implants retaining multiple nanoparticles in areas which were not overgrown by bone. Analysis of the bone-implant contact area revealed comparable results for both types of coatings. These finding indicated that SN doped HA coatings are characterised by good osseointegrative properties.  Conclusions: Since SNs were found in areas not covered by mineralised bone, it is assumed that the antimicrobial properties of the modified coating may be retained for 12 weeks after implantation. Additional studies are required to fine--tune the composition of HA coatings with SNs, to ensure optimal osseointegrative and antimicrobial properties.

Echocardiography findings in patients with ST segment elevation myocardial infarction and type 2 diabetes mellitus treated with primary percutaneous coronary angioplasty

Background: The development of heart failure following myocardial infarction (MI) in patients with diabetes mellitus (DM) is related to the extent of the infarction zone and underlying primary diabetic cardiomyopathy. Echocardiography allows the monitoring of systolic dysfunction following MI. Left ventricular ejection fraction (LVEF) is one of the most important prognostic indicators in patients after MI. Methods: The aim of the study was to assess the effect of type 2 DM on postinfarct left ventricular (LV) remodeling in patients with acute ST segment elevation MI treated with primary percutaneous transluminal coronary angioplasty. One hundred and ten patients were enrolled to the study and divided into two groups: group 1 included 41 subjects with type 2 DM, and group 2 included 57 subjects without DM. Echocardiographic parameters of LV systolic function including LVEF, LV end-diastolic volume (LVEDV), and LV end-systolic volume (LVESV) were compared between the study groups. Results: Both study groups showed statistically significant decrease in LVEF. However, significant LV dilatation was seen only in patients without DM but not in patients with DM. Conclusion: Long-term DM leads to the remodeling and the fibrosis of cardiac interstitial tissue, limiting acute ventricular dilatation and resulting in stiffening of the heart

Disturbances of blood pressure and spectral heart rate variability during orthostatic stress in patients with type 1 diabetes mellitus

Background: Orthostatic hypotension in diabetes patients is a sign of autonomic dysfunction. Heart rate variability (HRV) analysis is one of the methods for cardiac autonomic neuropathy assessment. The aim of this study was to assess blood pressure and HRV during 5 minute upright tilting in patients with type 1 diabetes. Methods: We studied 48 normotensive diabetes patients aged 18-28 years, with diabetes lasting 9-23 years. Matched control group consisted of 32 healthy persons. We performed 24 h Holter ECG monitoring (SUPRIMA 12, DMS, USA) and ambulatory blood pressure monitoring (Spacelab 90207, Datex-Ohmeda, USA). Manual measurements were initialized every minute during 5 minute standing, preceded by 15 min rest in supine position. Spectral HRV parameters were analyzed: total power (TP), very low frequency (VLF), low frequency (LF) and high frequency (HF) -in 5-min periods in supine and standing position. Results: Systolic blood pressure fall was noted in 19% of diabetes patients and 3% of the controls (p = 0.001) and DBP fall in 23% of diabetes patients and 0% of the controls (p = 0.001). During rest diabetes patients with orthostatic hypotension showed significantly lower TP and VLF spectra (p = 0.001). After tilting lower TP, VLF, LF and HF in diabetes patients with orthostatic hypotension was observed (p = 0.001). In standing position LF (NU, normalized units) decreased in diabetes patients in contrast to healthy people, in which LF spectrum increased. Conclusions: Diabetes patients with orthostatic hypotension have more advanced autonomic dysfunction than diabetes patients without orthostatic hypotension, which manifests as lower spectral HRV components during tilting. Diabetes patients show pathological fall of LF (NU) component during orthostatic stress

Role of induction time and other properties in the recovery of coal from aqueous suspensions by agglomeration with heptane

The percent recovery of fine coal or graphite particles suspended in water by agglomeration with heptane was highly dependent on the measured induction time, i.e., the gas bubble to particle attachment time of the material. The induction time was found to correlate closely with the heat of immersion of the solids in water, another indicator of the hydrophobic/hydrophilic character of the material. For a series of coals and graphite, the agglomeration recovery decreased exponentially with increasing induction time. For the more oleophilic coal or graphite particles, an increase in salt (NaC1) concentration of the suspending medium caused an increase in agglomeration recovery and a decrease in induction time. For the less oleophilic coal or pyrite particles, an increase in salt concentration caused a decrease in agglomeration recovery apd an increase in induction time. Due to the opposing effects of salt concentration on the recoveries of a highly hydrophobic coal and pyrite, it was possible to improve the separation of these materials by an increase in salt concentration. On the other hand, because the recoveries of pyrite and a weakly oleophilic coal were affected similarly by an increase in salt concentration, it was not possible to improve the separation of these materials

Ossa Sesamoidea — prevalence of sesamoid bones in human hands

Background: This study describes the morphology of sesamoid bones in the human hand. Ultrasound imaging was used to record the presence and measurements of sesamoids in 120 hands of 60 healthy, young adults of Caucasian ethnicity. Materials and methods: The mean number of sesamoid bones was 4.16 in the left hand and 4.03 in the right hand. 21.6% of cases showed asymmetry between the right hand and the left. There was a significant difference in the prevalence of sesamoid bones between right and left hand in males in this study. Females show a higher incidence of sesamoid bones overall, but do not demonstrate a significant difference between the sides. Results: Prevalence findings: Two in the 1st metacarpophalangeal joint (MCPJ) in 99.2% of cases, with 1 case of a single bone. One in the 2nd MCPJ in 43.3% of cases. One in the 5th MCPJ in 84.2% of cases. One in the 1st interphalangeal joint (IPJ) in 83.4% of cases. Aside from that there was 1 case of sesamoid in the 3rd MCPJ and separate case of sesamoid in the 3rd proximal IPJ. Conclusions: Moreover, this study discusses discrepancies of opinion regarding sesamoid bones in morphological research