scholarly journals Pull-off characteristics of double-shanked compared to single-shanked ligation clips: an animal study

2016 ◽  
Vol 1 (1) ◽  
pp. 41-46
Author(s):  
Martin Schenk ◽  
Gottfried Müller ◽  
Tim Oliver Greiner ◽  
Christine Fahrner ◽  
Alfred Königsrainer ◽  
...  
Keyword(s):  
Laparoscopic Surgery ◽  
Critical Point ◽  
Animal Study ◽  
Gold Standard ◽  
Porcine Model ◽  
The Other ◽  
Sectional Area ◽  
Cross Sectional ◽  
Surgical Ligation ◽  
Deep Indentation

AbstractBackground: The use of surgical ligation clips is considered as the gold standard for the closure of vessels, particularly in laparoscopic surgery. The safety of clips is mainly achieved by the deep indentation of the metal bar with a high retention force. A novel double-shanked (DS) titanium clip was compared to two single-shanked clips with respect to axial and radial pull-off forces.Methods: In a porcine model (8 animals, 51±1 kg), arteries were prepared immediately after euthanisation, assigned to either a medium (2–4 mm; n=120) or a medium-large (3.5–7 mm; n=120) clip size group, and clipped with the appropriate clip size. After dissection, axial and radial pull-off forces were measured.Results: The axial pull-off force of the DS-Clip was higher than one single-shanked clip and comparable to the other single-shanked clip, and overall was linearly correlated to the cross-sectional area of the clip. The radial pull-off force of the DS-Clip was significantly higher than both single-shanked clips and, for the single-shanked clips, was correlated to the total clip thickness. The variation of radial pull-off force was lower for the DS-Clip due to a defined catch in the clip applier.Conclusions: The radial pull-off force was lower than the axial pull-off force in total and therefore appears to be the critical point of dislocation. Due to the higher total holding mass, the DS-Clip provided a clear advantage in this regard and might therefore decrease the dislocation rate. The catch in the applier increases the reproducibility in clip placement.

CFD Solution of a Two-Canopy Parachute in a Top-to-Top Formation With a Vent of Air From One of Its Canopy

2008 ◽  
Author(s):  
Mohammad J. Izadi
Keyword(s):  
Cross Sectional Area ◽  
The Body ◽  
The Other ◽  
Bluff Bodies ◽  
Variable Cross ◽  
Sectional Area ◽  
Cross Sectional ◽  
Drag Forces ◽  
Varied Form ◽  
Two Bodies

A CFD study of a 3 Dimensional flow field around two bodies (Two Canopies of a Parachutes) as two bluff bodies in an incompressible fluid (Air) is modeled here. Formations of these two bodies are top-to-top (One on the top of the other) with respect to the center of each other. One canopy with a constant cross sectional area with a vent of air at its apex, and the other with a variable cross sectional area with no vent is studied here. Vertical distances of these two bodies are varied form zero to half, equal, double and triple radius of the body with a vent on it. The flow condition is considered to be 3-D, unsteady, turbulent, and incompressible. The vertical distances between the bluff bodies, cross sectional area, and also vent ratio of bluff bodies are varied here. The drag forces with static pressures around the two bodies are calculated. From the numerical results, it can be seen that, the drag coefficient is constant on the range of zero to twenty percent of the vent ratio and it decreases for higher vent ratios for when the upper parachute is smaller than the lower one, and it increases for when the upper parachute is larger than the lower one. Both Steady and Unsteady cases gave similar results especially when the distance between the canopies is increased.

The thickness and collagen content of tendon relative to the strength and cross-sectional area of muscle

1965 ◽  
Vol 162 (986) ◽  
pp. 137-146 ◽  
Keyword(s):  
Fibrous Tissue ◽  
Cross Sectional Area ◽  
The Other ◽  
Sectional Area ◽  
Cross Sectional ◽  
Maximum Tension ◽  
White Type ◽  
Fusiform Muscle ◽  
Mechanical Influence ◽  
Tendon Collagen

The orientation of fibrous tissue in tendon suggests a mechanical influence upon the growth of collagen, but in adult rabbits no strict correlation was found between the thickness of certain tendons and the strength of their muscles. The maximum tension transmitted by the collagen in tendons of three fusiform muscles was over fifty per cent greater than that transmitted by the same amount of tendon collagen in three penniform muscles. A similar though smaller difference between these two groups was found in the thickness of their tendons relative to the cross-sectional area of their muscle fasciculi. The tendon of a slow, red, fusiform muscle was relatively thicker than those of the other muscles which were all of the fast, white type.

scholarly journals Could TDX-1 explain the changes observed in endocrine pancreas due to chronic cola drink consumption in rats? A global point of view

2020 ◽  
Author(s):  
Gabriel Cao ◽  
Julián González ◽  
Juan P. Ortiz Fragola ◽  
Angélica Muller ◽  
Mariano Tumarkin ◽  
...  
Keyword(s):  
Body Weight ◽  
Glucose Tolerance ◽  
Islet Cells ◽  
Cross Sectional Area ◽  
The Other ◽  
Cell Area ◽  
Sectional Area ◽  
Β Cells ◽  
Β Cell ◽  
Cross Sectional

AbstractIn previous studies, we reported evidence showing that chronic cola consumption in rats impairs pancreatic metabolism of insulin and glucagon and produces some alterations typically observed in the metabolic syndrome (i.e, hyperglycemia, and hypertriglyceridemia) with an increase in oxidative stress. Of note, no apoptosis nor proliferation of islet cells could be demonstrated. In the present study, 36 male Wistar rats were divided in three groups to freely drink regular cola, light cola, or water (controls). We assessed the impact of the three different beverages in glucose tolerance, lipid levels, creatinine levels and immunohistochemical changes addressed for the expression of insulin, glucagon, PDX-1 and NGN3 in islet cells, to evaluate the possible participation of PDX-1 in the changes observed in α and β cells after 6 months of treatment. On the other hand, we assessed by stereological methods, the mean volume of islets (Vi) and three important variables, the fractional β-cell area, the cross-sectional area of alpha (A α-cell) and beta cells (A β-cell), and the number of β and α cell per body weight.Cola drinking caused impaired glucose tolerance as well as fasting hyperglycemia and increase of insulin immunolabeling. Immunohistochemical expression for PDX-1 was significantly high in regular cola consumption group compared to control. In this case, we observed cytoplasmatic and nuclear localization. Likewise, a mild but significant decrease of Vi was detected after 6 months of cola drink consumption compared with control group. Also, we observed a significant decrease of fractional β cell area compared with control rats. Accordingly, a reduced mean value of islet α and β cell number per body weight compared to control was detected. Interestingly, consumption of light cola increased the Vi compared to control. In line with this, a decreased cross-sectional area of β-cells was observed after chronic consumption of both, regular and light cola, compared to controls. On the other hand, NGN3 was negative in all three groups. Our results support for the first time, the idea that TDX-1 plays a key role in the dynamics of the pancreatic islets after chronic consumption of sweetened beverages. The loss of islets cells might be attributed to autophagy, favored by the local metabolic conditions.

scholarly journals On a method of determining the viscosity of gases, especially those available only in small quantities

1910 ◽  
Vol 83 (562) ◽  
pp. 265-276 ◽  
Keyword(s):  
Volume Content ◽  
Capillary Tube ◽  
Cross Sectional Area ◽  
The Other ◽  
Sectional Area ◽  
Cross Sectional ◽  
Fine Capillary ◽  
The Difference ◽  
Absolute Measurements ◽  
Unlimited Amount

The apparatus about to be described was designed for the purpose of comparing the viscosities of neon, xenon, and krypton—the loan of which Sir William Ramsay kindly offered the author—with that of air. With such small quantities of gas available, the volume content of the apparatus must obviously be correspondingly small, and therefore, it would seem, unsuitable for absolute measurements. The object of the present paper is to show that this is by no means the case. As will be seen later, the method is actually restricted to small quantities by the conditions of the experiments, but there is no reason why it should not be used even when the gas under test may be obtained in practically unlimited amount. Theory of the Method . Consider a closed glass vessel (as in fig. 1) consisting of two connected limbs, one a fine capillary tube and the other of much greater cross-sectional area, yet sufficiently narrow for a pellet of mercury to remain intact in it. Let V be the volume unoccupied by mercury (the volume of the capillary tube being considered negligible). Let P denote the steady pressure of the gas in the tube when the latter is held horizontally, and let p be the difference of pressure caused by the mercury pellet when the apparatus is vertical. Let p 1 be the pressure and v 1 the volume at any time above the mercury, and p 2 , v 2 , the corresponding quantities below the mercury. Then V = v 1 + v 2 , and p 2 - p 1 = p .

scholarly journals Yield and Fruiting Characteristics of 28 Selections in the Kentucky Pawpaw Cultivar Trial

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 851A-851
Author(s):  
Kirk W. Pomper* ◽  
Joseph G. Masabni ◽  
Desmond R. Layne ◽  
Sheri B. Crabtree ◽  
R. Neal Peterson ◽  
...  
Keyword(s):  
Research Effort ◽  
Total Yield ◽  
Fruit Weight ◽  
The Other ◽  
Sectional Area ◽  
Cross Sectional ◽  
Yield Efficiency ◽  
Variety Trial ◽  
Asimina Triloba ◽  
Tree Survival

The pawpaw [Asimina triloba (L.) Dunal] has great potential as a new fruit crop. A pawpaw variety trial was established in Fall 1995 in Princeton, Ky. as a joint Kentucky State Univ.-Univ. of Kentucky research effort with the objective to identify superior varieties for Kentucky. A randomized block experimental design was used with 8 replicates of 28 grafted scion selections on seedling rootstock. Cultivars being tested included Middletown, Mitchell, NC-1, Overleese, PA-Golden, Rappahannock, Shenandoah, Sunflower, Susquehanna, Taylor, Tay-two, Wells, and Wilson. The other 15 clones were selections from the PawPaw Foundation. In 2002 and 2003, the following parameters were examined: tree survival, trunk cross-sectional area (TCSA), average fruit weight, total fruit harvested per tree, average fruit per cluster, total yield per tree, and yield efficiency. In 2003, 54% of the trees had survived, with `Susquehanna' (13%) showing the poorest survival. Based on TCSA, most selections displayed excellent vigor, with the exception of the selections: 5-5 and `Overleese'. Average fruit weight was greatest in 1-7-2 (194 g), 1-68 (167g), 4-2 (321 g), 5-5 (225 g), 7-90 (166g), 9-58 (176 g), 10-35 (167 g), NC-1 (180 g), `Sunflower' (204 g), and `Shenandoah' (168g), with the smallest fruit in `Middletown' (70 g), `Wells' (78 g), and `Wilson' (88 g). The selections `Wilson' (81), `Middletown' (75), and `Wells' (70) had the greatest average number of fruit per tree, whereas 4-2 (9), 5-5 (17) and 8-20 (15) the fewest. Yield efficiency and average fruit per cluster also varied greatly among selections. Several pawpaw selections in the trial show promise for production in Kentucky.

scholarly journals Evaluation of several less known pear (Pyrus communis L.) cultivars in the climatic conditions of Lower Silesia

2012 ◽  
Vol 65 (4) ◽  
pp. 157-162 ◽  
Author(s):  
Ireneusz Sosna ◽  
Daria Kortylewska
Keyword(s):  
Fruit Quality ◽  
Total Yield ◽  
Climatic Conditions ◽  
Cross Sectional Area ◽  
The Other ◽  
Sectional Area ◽  
Cross Sectional ◽  
Experimental Station ◽  
Pyrus Communis L ◽  
Lower Silesia

The aim of this study was to evaluate flowering, yielding, fruit quality, and growth of several less known pear cultivars growing in the climatic conditions of Lower Silesia. The experiment was conducted in the years 2006–2010 in the Fruit Experimental Station located in Samotwór near Wrocław. In spring 2006, trees of several less known pear cultivars were planted: 'Isolda', 'Hortensia', 'Fertilia Delbard Delwilmor', 'Wyżnica', 'Nojabrskaja' ('Xenia®'), 'Uta', 'David' on Caucasian pear (<em>Pyru</em><em>s caucasica </em>Fed.), 'Bohemica' on quince S1 (<em>Cydoni</em><em>a oblonga </em>Mill.) as well as 'Morava' and 'Blanka' on both these rootstocks. The highest total yield in the years 2007–2010 was recorded for the 'Nojabrskaja' and 'Wyżnica' cultivars. The 'Blanka' cultivar produced the largest fruit, while fruits of the 'Isolda' cultivar were significantly the smallest. The largest growth and cross-sectional area of the trunk were recorded for the trees of the 'Wyżnica' cultivar, while the smallest were observed in the case of 'Morava', in which the thickness of the trunk was similar on both rootstocks. The 'Morava' cultivar grafted on quince S1 formed the smallest crowns. On the other hand, 'Isolda' and 'Hortensia' were among the cultivars that produced the largest crowns.

scholarly journals A primary inferior lumbar hernia misdiagnosed as a lipoma

2019 ◽  
Vol 101 (4) ◽  
pp. e96-e98 ◽  
Author(s):  
B Kadler ◽  
A Shetye ◽  
DK Patten ◽  
A Al-Nowfal
Keyword(s):  
Laparoscopic Surgery ◽  
Gold Standard ◽  
Mesh Repair ◽  
Surgical Intervention ◽  
Lumbar Hernia ◽  
Cross Sectional ◽  
Open Mesh Repair ◽  
Cross Sectional Imaging ◽  
Sectional Imaging ◽  
Open Mesh

Lumbar hernias can be superior (Grynfelt) and inferior (Petit). Inferior lumbar hernias are extremely rare and, therefore, are associated with diagnostic difficulty. We present a case of a primary spontaneous inferior lumbar hernia in a 79-year-old woman that was initially diagnosed as a large lipoma on ultrasound. The first operation was abandoned and an open mesh repair was conducted.Lumbar hernias can be primary acquired (55%), secondary acquired (25%) or congenital (20%). Cross-sectional imaging by CT or MRI appears to be the gold standard in diagnosis as ultrasound may lead to misdiagnosis. Strangulation, incarceration and obstruction are recognised complications, requiring prompt surgical intervention. There are currently no guidelines for surgical managements, although laparoscopic surgery may give the best results. In view of the scarcity of published cases, we aim to add to the literature to raise the index of suspicion and to promote prompt surgical management of lumbar hernias.

Are interatrial band myocytes maximally hypertrophied in normal canine hearts?

1998 ◽  
Vol 275 (4) ◽  
pp. H1225-H1235
Author(s):  
Paul C. Dolber ◽  
Robert P. Bauman ◽  
Judith C. Rembert ◽  
Joseph C. Greenfield
Keyword(s):  
Cross Sectional Area ◽  
The Other ◽  
Right Atrial ◽  
Sectional Area ◽  
Atrial Myocytes ◽  
Maximal Volume ◽  
Cross Sectional ◽  
Other Hand ◽  
Volume Curve ◽  
Atrial Myocyte

In canine right atrial hypertrophy, the cross-sectional area ( A xs) of right atrial myocytes increases, whereas the A xs of the broader interatrial band myocytes does not. In the current study, myocyte reconstructions showed that right atrial myocyte length increased in proportion to A xs in right atrial hypertrophy. On the other hand, mean interatrial band myocyte length in both normal and right atrial hypertrophy dogs was roughly inversely proportional to mean A xs, as expected if interatrial band myocyte volume was constant. Plotting mean A xs vs. myocyte length for individual interatrial band myocytes revealed a distribution whose border defined a maximal volume curve; many myocytes were well beneath that curve. Mononuclear myocytes (generally diploid) were limited by a 65,000-μm3 curve, which many binuclear myocytes (generally tetraploid) surpassed; myocyte ploidy thus constrained myocyte volume. However, because many mononuclear and binuclear myocytes had lower volumes, their failure to hypertrophy cannot be attributed to attainment of the maximal volume possible for their ploidy.

scholarly journals Yield efficiency for nine apple cultivars grafted on two rootstocks

2016 ◽  
Vol 46 (10) ◽  
pp. 1701-1706 ◽  
Author(s):  
João Caetano Fioravanço ◽  
Ana Beatriz Costa Czermainski ◽  
Paulo Ricardo Dias de Oliveira
Keyword(s):  
Apple Tree ◽  
Cross Sectional Area ◽  
The Other ◽  
High Yield ◽  
Lower Amount ◽  
Sectional Area ◽  
Cross Sectional ◽  
Yield Efficiency ◽  
The Third ◽  
Apple Cultivars

ABSTRACT: Currently, using smaller trees is one of the most important trends in apple cultivation. It is expected that reduced size plants produce lower amount of fruit, but with high yield and yield efficiency. The aim of this study was to evaluate the yield efficiency (YE) of nine apple tree cultivars, grafted on two rootstocks, from the second to the seventh year after planting. The YE indexes oscillated from one to the other year, regardless of rootstock. Correlations between YE and yield per tree and between YE and trunk cross sectional area (TCSA) confirmed that efficiency can be increased by the production increment or by the plant's vigor reduction. The usefulness of cumulative YE (ƩYE) is highlighted to compare apple tree cultivars after the third year of production. The highest ƩYE indexes were observed for 'Royal Gala' and 'Baigent', on M-9 rootstock, and for 'Gala Real' and 'Maxi-Gala', on Marubakaido/M-9 rootstock.

scholarly journals Sex-Specific Function and Morphology of the Anterior Cruciate Ligament During Skeletal Growth in a Porcine Model

2021 ◽  
Author(s):  
Danielle Howe ◽  
Stephanie G. Cone ◽  
Jorge A. Piedrahita ◽  
Bruce Collins ◽  
Lynn A. Fordham ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Porcine Model ◽  
Cruciate Ligament ◽  
Joint Laxity ◽  
Cross Sectional Area ◽  
Skeletal Growth ◽  
Sectional Area ◽  
Anteromedial Bundle ◽  
Cross Sectional ◽  
Anterior Cruciate

Pediatric anterior cruciate ligament (ACL) injuries are on the rise, and females experience higher ACL injury risk than males during adolescence. Studies in skeletally immature patients indicate differences in ACL size and joint laxity between males and females after the onset of adolescence. However, functional data regarding the ACL and its anteromedial and posterolateral bundles in the pediatric population remain rare. Therefore, this study uses a porcine model to investigate the sex-specific morphology and function of the ACL and its bundles throughout skeletal growth. Hind limbs from male and female Yorkshire pigs aged early youth to late adolescence were imaged using magnetic resonance imaging to measure the size and orientation of the ACL and its bundles, then biomechanically tested under anterior-posterior drawer using a robotic testing system. Joint laxity decreased (p<0.001) while joint stiffness increased (p<0.001) throughout skeletal growth in both sexes. The ACL was the primary stabilizer against anterior tibial loading in all specimens, while the functional role of the anteromedial bundle increased with age (p<0.001), with an earlier shift in males. ACL and posterolateral bundle cross-sectional area and ACL and anteromedial bundle length were larger in males than females during adolescence (p<0.01 for all), while ACL and bundle sagittal angle remained similar between sexes. Additionally, in situ ACL stiffness correlated with cross-sectional area across skeletal growth (r2=0.75, p<0.001 in males and r2=0.64, p<0.001 in females), but not within age groups. This study has implications for age and sex-specific surgical intervention strategies and suggests the need for human studies.

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