649 EFFECTS OF THE PREPARATION METHOD ON THE ICG FLUORESCENCE BLOOD FLOW IN THE GASTRIC CONDUIT AFTER ESOPHAGECTOMY

In this study, we investigated how the blood flow of gastric conduit changed due to the difference in the lesser curvature cut line using ICG fluorescence imaging in patients with esophageal cancer. Methods A total of 193 cases of esophageal cancer surgery with gastric conduit reconstruction were included. (Conventional method) The lesser curvature cut line of the stomach was started from a distance of 5 cm from the pylorus (141 cases). (Current method) Gastric lesser curvature dissection was started from the last branch of the left gastric artery (52 cases). Blood flow of the gastric conduit was measured by the ICG fluorescence imaging, and the correlation between the changes in the gastric conduit and both blood flow and anastomotic failure was examined. Results Median length of the lesser curvature cut line was 10 cm from the pylorus in the current method, which was significantly longer than that in the conventional method (P < 0.001). Congestion at the tip of the gastric conduit were more observed in the conventional method (P = 0.02). The ICG fluorescent blood flow speed in the gastric conduit wall was 2.54 cm/s by the conventional method and 2.82 cm/s by the current method (P = 0.03). There were 23 cases (16.3%) of anastomotic leakage in the conventional method and 4 cases (7.7%) in the current method (P = 0.09). Conclusion By preserving the right gastric artery and vein, improvement of venous return is expected, and it is suggested that blood flow in the gastric conduit wall can be well maintained.

Divergence of stem biomechanics and hydraulics between Bauhinia lianas and trees

Liana abundance and biomass are increasing in neotropical and Asian tropical seasonal forests over the past decades. Stem mechanical properties and hydraulic traits influence the growth and survival of plants, yet the differences in stem mechanical and hydraulic performance between congeneric lianas and trees remain poorly understood. Here, we measured 11 stem mechanical and hydraulic traits for 10 liana species and 10 tree species from Bauhinia grown in a tropical common garden. Our results showed that Bauhinia lianas possessed lower stem mechanical strength as indicated by both modulus of elasticity and modulus of rupture, and higher stem potential hydraulic conductivity than congeneric trees. Such divergence was mainly attributed to the differentiation in liana and tree life forms. Whether the phylogenetic effect was considered or not, mechanical strength was positively correlated with wood density, vessel conduit wall reinforcement and sapwood content across species. Results of principle component analysis showed that traits related to mechanical safety and hydraulic efficiency were loaded in the opposite direction, suggesting a trade-off between biomechanics and hydraulics. Our results provide evidence for obvious differentiation in mechanical demand and hydraulic efficiency between congeneric lianas and trees.

Analyzing the tremor of the Holuhraun eruption 2014-2015 using tremor modelling

<p>The 2014-2015 Holuhraun eruption was the largest eruption in Iceland in the last 230 years. After magma ascended below <!-- Gibt es ein Paper das belegt, dass Magmaaufstieg den Dike getriggert hat? Ich denke, das ist eher Spekulation. Vllt. wäre es besser einfach zu sagen, „From ice-covered Bardarbunga an about 2 week long EQ migration …“ -->the Bárðarbunga volcano’s icecap, an about 2 week long lateral migration of earthquakes was observed; later interpreted as dike formation in 4km to 6km depth<!-- Noch die Tiefe (formation [in 4-6km depth]) mit reinbringen? --><!-- Ja kannst du machen. -->. An eruption started on 29<sup>th</sup> and 31<sup>st</sup> of August 2014 at Holuhraun. During dike formation and eruption a long-lasting seismic signal called tremor was recorded by seismometers in the area. Eruptive tremor emerged with the onset of the eruptions on 29<sup>th</sup> and 31<sup>st</sup> of August . Tremor sources were located and interpreted in the context of the fissure and the lava flow field. However, a complete geophysical model to explain these is missing. Our starting point is the model on tremor generation based on conduit wall vibrations exited by laminar flow<!-- Bitte anpassen. --> (B. Julian 1994) to replicate the observed tremor signals. We performed a grid search and compare it with other models. In the range of rock parameter tolerance, we present implied characteristics of frequency and amplitude of the signals, if the Julian model were used as explanation for the tremor signals.</p>

Screening for potential targets to reduce stenosis in bioprosthetic heart valves

Progressive stenosis is one of the main factors that limit the lifetime of bioprosthetic valved conduits. To improve long-term performance we aimed to identify targets that inhibit pannus formation on conduit walls. From 11 explanted, obstructed, RNAlater presevered pulmonary valved conduits, we dissected the thickened conduit wall and the thin leaflet to determine gene expression-profiles using ultra deep sequencing. Differential gene expression between pannus and leaflet provided the dataset that was screened for potential targets. Promising target candidates were immunohistologically stained to see protein abundance and the expressing cell type(s). While immunostainings for DDR2 and FGFR2 remained inconclusive, EGFR, ErbB4 and FLT4 were specifically expressed in a subset of tissue macrophages, a cell type known to regulate the initiation, maintenance, and resolution of tissue repair. Taken toghether, our data suggest EGFR, ErbB4 and FLT4 as potential target candidates to limit pannus formation in bioprosthestic replacement valves.

162 IMPACT OF FLOW SPEED OF ICG FLUORESCENCE IN THE GASTRIC CONDUIT AND THORACIC INLET SPACE ON ANASTOMOTIC LEAKAGE AFTER ESOPHAGECTOMY

We have previously demonstrated that the flow speed of indocyanine green (ICG) fluorescence in the gastric conduit wall could predict anastomotic leakage after esophagectomy. Surround organs via retrosternal route is considered to affect the blood flow in the gastric conduit and anastomotic leakage. In the study, we investigated the impact of the flow speed of ICG fluorescence in the gastric conduit wall and thoracic inlet space on anastomotic leakage after esophagectomy. Methods A total of 142 patients, who underwent esophagectomy with three-field lymph node dissection, simultaneous reconstruction using a gastric conduit, and cervical anastomosis via retrosternal route, were prospectively investigated. Using ICG fluorescence imaging, blood flow speed of the gastric conduit wall was assessed before and after anastomosis (pre speed and post speed (cm/s)) and correlated with clinicopathological findings. Parameters of thoracic inlet space was assessed using CT scan and correlated with blood flow speed of the gastric conduit wall and anastomotic leakage. Results Median pre speed was 2.54 (0.73–6.10) cm/s and median post speed was dropped by 1.77 (0.32–8.67) cm/s. Speed reduction (pre speed—post speed) and speed reduction rate ((pre speed—post speed)/pre speed) were negatively correlated with thoracic inlet area (TIA) (P = 0.004, P = 0.021). Pre speed and post speed of the patients with anastomotic leakage were significantly slower than those of the patients without anastomotic leakage, respectively (P < 0.001 and P = 0.050). In 115 patients with pre speed more than 1.98 cm/s, TIA was significantly associated with anastomotic leakage after esophagectomy (P < 0.001). Conclusion We clearly demonstrated that retrosternal route reduced the blood flow of the gastric conduit wall using ICG fluorescence imaging. Narrow thoracic inlet space might obstruct the blood flow of the gastric conduit wall and cause anastomotic leakage after esophagectomy.

Within-ring variability of wood structure and its relationship to drought sensitivity in Norway spruce trunks

ABSTRACTRelationships between hydraulic vulnerability expressed as P50 (the air pressure causing 50% loss of hydraulic conductivity) and within-ring differences in wood density (WD) and anatomical features were investigated with the aim to find efficient proxies for P50 relating to functional aspects. WD and tracheid dimensions were measured with SilviScan on Norway spruce (Picea abies (L.) Karst.) trunk wood.P50 was strongly related to mean WD (r = -0.64) and conduit wall reinforcement ((t/b)2), the square of the ratio between the tracheid double wall thickness (t) and the lumen width (b), where use of tangential lumen width ((t/bt)2) gave better results (r = -0.54) than radial lumen width (r = -0.31). The correlations of P50 with earlywood (EW), transition wood (TW) and latewood (LW) traits were lower than with the specimen averages, both for WD (r = -0.60 for WDEW, r = -0.56 for WDTW, r = -0.23 for WDLW) and all anatomical traits. The loss of hydraulic conductivity was addressed as a dynamic process and was simulated by defining consecutive phases of 5% theoretical conductivity loss. WD and tracheid traits were calculated and correlated with P50 values of each specimen. Tightest correlations were found for (t/bt)2, at relative cumulated theoretical conductivities until 45 to 50% (r = -0.75).We conclude that WD is one of the best available proxies for P50, but does not necessarily reflect the mechanism behind resistance to cavitation. The new trait, based on estimation of conductivity loss as a dynamic process, provided even stronger correlations.

Chronology of hydraulic vulnerability in trunk wood of conifer trees with and without symptoms of top dieback

There is evidence that recently occurring top dieback of Norway spruce (Piceaabies(L.) Karst.) treesin southern Norway is associated with drought stress. We comparedfunctional wood traits of20 healthy looking trees and 20 trees with visual signs of top dieback. SilviScan technology was applied to measure cell dimensions (lumen and cell wall thickness) in a selected set of trunk wood specimens where vulnerability to cavitation (P50) datawere available. The conduit wall reinforcement ((t/b)²) was a good proxy for P50. Cell dimensions were measured on wood cores of all 40 trees; theoretical vulnerability of single annual rings could bethus estimated. Declining trees tended to have lower (t/b)² before and during a period of water deficit (difference between precipitation and potential evapotranspiration)that lasted from 2004 to 2006. The results are discussed with respect to genetic predisposition.

Electrostatic Preclusion of Droplet Adhesion in a Microchannel

In many multiphase fluidic processes, such as in petroleum extraction and biochemical analysis involving microscale conduits, the lodging of immiscible droplets often leads to disastrous flow blockage. Without a thin-film lubrication layer surrounding the adhered droplets, a significantly higher threshold pressure gradient is required to reinitiate bulk flows. In this work, we investigate the surface tension-driven thin-film drainage process that leads to droplet adhesion and study how electrostatic repulsion between a charged droplet interface and a charged conduit wall can prevent direct contact between the two. We report on our multiphysics computational results of an oversized gas droplet in a water-filled flow microchannel under the influence of surface tension and interfacial electrostatic forces.

Study on Irrigation Model Based on Plant Ultrasonic Acoustic Emissions

Produced by cohesion between water molecules or adhesion to the conduit wall, the plant cavitation is accompanied by the vessel walls vibration which is the indicator of the water stress. The ultrasonic acoustic emissions (UAEs) are used to detect the plant cavitation events which are the transmission of vibration. The UAEs could be detected in ultrasonic frequencies between 100K Hz and 1 MHz. The PCI-2 data acquisition (DAQ) equipment and R15 sensors are used to improve the precision of cavitation detection. When the water stress and dehydration gets heavier, the UAEs rate gets higher. Use the tomato practice data with the empirical deduction under the modern greenhouse conditions, the UAEs and Transpiration Index (UAETI) and the UAEs Irrigation Index (UAEII) irrigation model are draw from the relationship between transpiration and UAEs. UAETI can be used to analysis the transpiration, and UAEII can be used to analysis the irrigation time. It is better to use UAEs technique to carry out automatic and precise irrigation for the plant and to improve the effect of Water-saving irrigation.