Experimental research on deformation and dimensional accuracy of rectangular-section tubular part during open die hydro-pressing process

To solve the problems involving in the open die hydro-pressing process, such as different corner radii and bigger dimensional deviation, an open die hydro-pressing process was proposed and an experiment was conducted on hydro-pressing process of DP590 steel tubular part with rectangular-section. The effects of pressing sequence and supporting pressure on cross-sectional shape and corner filling were discussed. An analysis was conducted to reveal the reason for uneven deformation of the section corners. It is illustrated that the values of corner radii of the tubular part are obviously different under the condition of one pressing step, and the corner nearby the fixed die is larger than that nearby the pressing punch. The reason is that a difference exists in the circumferential force between the four corners due to the existence of the friction, which results in the uneven deformation on the section corner zone. The deviation of the cross-sectional dimension can be effectively improved by multi pressing steps, but too great a number of pressing steps also reduces the forming efficiency. Under the condition of two pressing steps, a rectangular-section tubular part with high dimensional accuracy was obtained by a reasonable pressure loading path. Its relative corner radius is only 2.5, which exceeds the limiting value of that formed by conventional tube hydroforming.

THE STRUCTURE OF THE NEPHRONS OF THE KIDNEYS OF PREMATURE INFANTS WITH EXTREMELY AND VERY LOW BODY WEIGHT, BORN AS A RESULT OF VERY EARLY PRETERM BIRTH AT THE POST-CONCEPTUAL AGE

It was found that children born as a result of early preterm birth are characterized by nephronogenesis, characterized by atypical increase in size, variability of nephron components, and recapitulation of mesonephronogenesis. The kidneys of premature infants with extremely low body weight are characterized by a peculiar structure, which is manifested in a reduced number of nephrons at birth, a pronounced glomerular-tubular imbalance – the structural and functional predominance of the glomerular component over the tubular part of the nephron. The concept of a new period of human ontogenesis is proposed – metanatal, which is understood as the period of life of a person born with extremely low and very low body weight as a result of early and early preterm birth, during 22–36 weeks of postconceptual age. The concept is based on the uniqueness of the structure-forming processes that occur in organs, which can not be evaluated as either embryo-fetal or postnatal ontogenesis processes after physiological delivery of 37–40 weeks of gestational age. Probably, these processes should be designated as postconceptual morphogenesis.

P2786Current ESC guidelines for normal ascending aortic diameter: prevalence of aortic dilatation increases to 20% in a consecutive coronary CTA population

Introduction Epidemiological studies on the prevalence of ascending aortic (AA) dilatation are scanty. Purpose To clarify prevalence of AA dilatation according to ESC 2014 guidelines and to study its risk factors. Methods This retrospective study included 1000 consecutive patients scheduled for diagnostic coronary artery computer tomography angiography (CCTA) with low to moderate pretest probability for coronary artery disease (CAD). AA diameter was measured at 3 planes; sinus valsalva, sinotubular junction and tubular part. Threshold for AA dilatation was set to >40 mm (ESC 2014). Traditional risk factors for AA dilatation were collected from medical records. Aortic size index (ASI) was used as a comparative measurement. ASI is defined as the ratio between aortic diameter and body surface area (BSA). The threshold for AA dilatation was set to upper limit of normal distribution exceeding two standard deviations (95%). Heart-aorta angle (HAA, Figure) was measured as one suggestive risk factor. Results Patients' mean age was 52.9±9.8 years, 66.5% were women. The prevalence of AA dilatation in the whole study population was 20.4% according to ESC 2014 guidelines. When patients with hypertension (n=445) or coronary calcifications or stenosis in CCTA (n=375) were excluded, the prevalence of AA dilatation was 14.5% in the population of normotensive patients without CAD (n=380). According to the normal-distributed ASI values the threshold for normal dimension of sinus valsalva was defined as 23.5 mm/m2 and for tubular part 22.7 mm/m2 for normotensive patients without CAD. Using these thresholds, the prevalence of AA dilatation was 7.8% in the whole population and 7.1% in normotensive patients without CAD. Smaller HAA was associated to AA dilatation. Median HAA was 125.6° (range: 119.2–131.5°) in patients with dilated AA and 130.1° (123.7–136.4°) in patients with non-dilated AA (p<0.001). Higher BSA was associated to larger AA dimensions. Risk factors for AA dilatation (according to ESC criteria) were male gender, BAV, hypertension and smoking (p<0.01). Figure 1 Conclusions The prevalence of AA dilatation proved to be relatively high in this consecutive CCTA population when using ESC 2014 guidelines. Body size is associated to AA dimensions; thus, it seems reasonable to include BSA in the definition of AA dilatation. Acknowledgement/Funding Oiva Vaittinen will grant, Aarne Koskelo Foundation

High prevalence of ascending aortic dilatation in a consecutive coronary CT angiography patient population

Objectives To clarify the prevalence and risk factors of ascending aortic (AA) dilatation according to ESC 2014 guidelines. Methods This study included 1000 consecutive patients scheduled for diagnostic coronary artery computed tomographic angiography. AA diameter was retrospectively measured in 3 planes: sinus valsalva, sinotubular junction, and tubular part. The threshold for AA dilatation was set to > 40 mm which has been suggested as an upper normal limit for AA diameter in ESC 2014 guidelines on aortic diseases. Aortic size index (ASI) using the ratio between aortic diameter and body surface area (BSA) was applied as a comparative measurement. The threshold for AA dilatation was set to the upper limit of normal distribution exceeding two standard deviations (95%). Risk factors for AA dilatation were collected from medical records. Results The patients’ mean age was 52.9 ± 9.8 years (66.5% women). The prevalence of AA dilatation was 23.0% in the overall study population (52.5% males) and 15.1% in the subgroup of patients with no coronary artery disease or bicuspid (BAV)/mechanical aortic valve (n = 365). According to the normal-distributed ASI values, the threshold for sinus valsalva was defined as 23.2 mm/m2 and for tubular part 22.2 mm/m2 in the subgroup. Higher BSA was associated with larger AA dimensions (r = 0.407, p < 0.001). Male gender (p < 0.001), BAV (p < 0.001), hypertension (p = 0.009) in males, and smoking (p < 0.001) appeared as risk factors for AA dilatation. Conclusions The prevalence of AA dilatation is high with current ESC guidelines for normal AA dimension, especially in males. Body size is strongly associated with AA dimensions; it would be more reliable to use BSA-adjusted AA diameters for the definition of AA dilatation. Key Points • The prevalence of AA dilatation is high in patients who are candidates for coronary CT angiography. • Body size is strongly associated with AA dimensions.

Macroscopic Aspects of the Cranial Mesenteric Artery (Arteria Mesenterica Cranialis) in Chinchilla Lanigera Species

In this study we have used 10 carcasses of chinchilla females slaughtered by the owner for commercial purposes. The studied animals have been subjected to an antemortem exam in which the semiological constants like: temperature; breats per minute and pulse were recorded. After the examination the subjects were declared clinically healthy. After skinning 30 ml coloring agent was injected intraluminally and dissection of the cranial mesenteric artery was performed. The first collateral branch of this vessel was the caudal pancreatico-duodenal artery (Arteria pancreaticoduodenalis caudalis), followed by 4-5 jejunal arteries (Arteriae jejunales). The cranial mesenteric artery gives off the dorsal cecal artery (Arteria cecalis dorsalis) as one of terminal branches to supply the haustrated part of cecum, the medial cecal artery (Arteria cecalis media) distributed to the tubular part of cecum (second terminal) and ileocolic artery (Arteria ileocolica)(the third terminal). To the best of our knowledge, our results brings significant information about the blood supply of intestines in chinchilla, that could be a real help for clinicians and researchers studying this topic.

Design of the Automatic Spraying Equipment for Tubular Parts

The automatic spraying equipment for tubular parts is used for spraying the tubular parts, especially the ones with the lengths from 1 meter to 15 meters and the diameters from 3 millimeters to 20 millimeters. The whole equipment includes frame, drive unit, fixture, anti-bending device, spray gun, protective cover and so on. During the spraying process, the tubular part will rotate and move forward, to make it get uniform surface coating. The equipment is installed with the anti-bending device, to prevent the tubular part from bending and shaking. The spraying process is controlled by the control system, which makes the automatic spraying come true.