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BACKGROUND: Irrigated radiofrequency ablation with half-normal saline can potentially increase lesion size but may increase the risk of steam pops with the risk of emboli or perforation. We hypothesized that pops would be preceded by intracardiac echocardiography (ICE) findings as well as a large impedance fall. METHODS: In 100 consecutive patients undergoing endocardial ventricular arrhythmia radiofrequency ablation with half-normal saline, we attempted to observe the ablation site with ICE. Radiofrequency ablation power was titrated to a 15 to 20 Ohm impedance fall and could be adjusted for tissue whitening and increasing bubble formation on ICE. Steam pops were defined as audible or a sudden explosion of microbubbles on ICE. RESULTS: Of 2190 ablation applications in 100 patients (82% cardiomyopathy, 50% sustained ventricular tachycardia), pops occurred during 43 (2.0%) applications. Sites with pops had greater impedance decreases of 18 [14, 21]% versus 13 [10, 17]% (P<0.001). ICE visualized 1308 (59.7%) radiofrequency sites, and fewer pops occurred when ICE visualized the radiofrequency ablation site (1.4%) compared with without ICE visualization (2.8%; P=0.016). Of the 18 ICE-visible pops, 7 (39%) were silent but recognized as an explosion of bubbles on ICE. With ICE, 89% of pops were preceded by either tissue whitening or a sudden increase in bubbles. In a multivariable model, tissue whitening and a sudden increase in bubbles were associated with steam pops (odds ratio, 7.186; P=0.004, and odds ratio, 29.93; P<0.001, respectively), independent of impedance fall and power. There were no pericardial effusions or embolic events with steam pops. CONCLUSIONS: Steam pops occurred in 2% of half-normal saline radiofrequency applications titrated to an impedance fall and are likely under-recognized without ICE. On ICE, steam pops are usually preceded by tissue whitening or a sudden increase in bubble formation, which can potentially be used to adjust radiofrequency application to help reduce pops. [ABSTRACT FROM AUTHOR]

Aims Failure of radiofrequency (RF) ablation of ventricular arrhythmias is often due to inadequate lesion size. Irrigated RF ablation with half-normal saline (HNS) has the potential to increase lesion size and reduce sodium delivery to the patient if the same volume of RF irrigant were used for normal saline (NS) and HNS but could increase risks related to steam pops and lesion size. This study aims to assess periprocedural complications and acute ablation outcome of ventricular arrhythmias ablation with HNS. Methods and results Prospective assessment of outcomes was performed in 1024 endocardial and/or epicardial RF ablation procedures in 935 consecutive patients (median age 64 years, 71.2% men, 73.4% cardiomyopathy, 47.2% sustained ventricular tachycardia). Half-normal saline was selected at the discretion of the treating physician. Radiofrequency ablation power was generally titrated to a ≤15 Ω impedance fall with intracardiac echocardiography monitoring. Half-normal saline was used in 900 (87.9%) and NS in 124 (12.1%) procedures. Any adverse event within 30 days occurred in 13.0% of patients treated with HNS RF ablation including 4 (0.4%) strokes/transient ischaemic attacks and 34 (3.8%) pericardial effusions requiring treatment (mostly related to epicardial access). Two steam pops with perforation required surgical repair (0.2%). Patients who received NS irrigation had less severe disease and arrhythmias. In multivariable models, adverse events and acute success of the procedure were not related to the type of irrigation. Conclusion Half-normal saline irrigation RF ablation with power guided by impedance fall and intracardiac echocardiography has an acceptable rate of complications and acute ablation success while administering half of the saline load expected for NS irrigation. [ABSTRACT FROM AUTHOR]

The classification of grapevine cultivars into isohydric and anisohydric categories depends on their ability to close stomata under conditions of low soil water availability or high atmospheric demand. This study aimed to compare the responses of Grenache, classified as isohydric, and Cabernet Sauvignon, classified as anisohydric, both grafted onto Richter 110 rootstock, and subjected to severe drought stress. Three cycles of drought stress were applied, followed by watering, while a well-watered treatment served as the control. Stomatal conductance and stem water potential were measured at predawn and midday during the drought cycles, and primary metabolites were analyzed in leaves and roots using gas chromatography. We found that Grenache had significantly higher stomatal conductance than Cabernet Sauvignon under both well-watered and water-stressed conditions. There were no significant differences in stem water potential between the two varieties, but the control treatment maintained a higher stem water potential at predawn and midday for both varieties. Primary metabolite analysis showed that both varieties accumulated sugars and polyols in their leaves and roots under drought stress, while organic acids were more abundant in leaves than in roots. Overall, the results suggest that the hydric behavior of grapevines depends on the intensity and duration of drought stress. In this study, both varieties exhibited near-isohydric behavior by regulating stomatal closure under drought stress. The metabolites identified in this study may serve as potential biomarkers of water drought stress in Grenache and Cabernet Sauvignon grapevines under the conditions of this experiment. [ABSTRACT FROM AUTHOR]

Based on data from 229 industry-federal laboratory projects, our research analyzes combinations of technical roles and laboratory characteristics to determine their relation to projects' effectiveness. The results show increased effectiveness when the combination of technical roles follows a 'gradient.' That is, performance is enhanced when the company plays a different technical role than the laboratory, but a role that is only a step away on the basic-applied-development spectrum. Effectiveness diminishes when both the company and the federal laboratory play the same technical role or when the technical roles are far apart on the basic-applied-development spectrum. The results may have general implications for public policy partnerships, suggesting that although partnership effectiveness requires distinctive roles, partner roles should not be so different as to undermine possibilities for coordination and integration., 1. Introduction In the United States and throughout most of the world, many public goods and services are delivered by public-private partnership. Public-private partnerships are viewed as institutional arrangements that [...]

Introduction: To target posterior wall isolation (PWI) in atrial fibrillation (AF) ablation, diffuse ablation theoretically confers a lower risk of conduction recovery compared to box set. We sought to assess the safety and efficacy of diffuse PWI with low‐flow, medium‐power, and short‐duration (LF‐MPSD) ablation, and evaluate the durability of pulmonary vein isolation (PVI) and PWI among patients undergoing repeat ablations. Methods: We retrospectively studied patients undergoing LF‐MPSD ablation for AF (PVI + diffuse PWI) between August 2017 and December 2019. Clinical characteristics were collected. Kaplan‐Meier survival analysis was performed to study AF/atrial flutter (AFL) recurrence. Ablation data were analyzed in patients who underwent a repeat AF/AFL ablation. Results: Of the 463 patients undergoing LF‐MPSD AF ablation (PVI alone, or PVI + diffuse PWI), 137 patients had PVI + diffuse PWI. Acute PWI with complete electrocardiogram elimination was achieved in 134 (97.8%) patients. Among the 126 patients with consistent follow‐up, 38 (30.2%) patients had AF/AFL recurrence during a median duration of 14 months. Eighteen patients underwent a repeat AF/AFL ablation after PVI + diffuse PWI, and 16 (88.9%) patients had durable PVI, in contrast to 10 of 45 (23.9%) patients who had redo ablation after LF‐MPSD PVI alone. Seven patients (38.9%) had durable PWI, while 11 patients had partial electrical recovery at the posterior wall. The median percentage of area without electrical activity at the posterior wall was 70.7%. Conduction block across the posterior wall was maintained in 16 (88.9%) patients. Conclusion: There was a high rate of PVI durability in patients undergoing diffuse PWI and PVI. Partial posterior wall electrical recovery was common but conduction block across the posterior wall was maintained in most patients. [ABSTRACT FROM AUTHOR]

This article investigates the dynamics of cancer through a coupled system of three nonlinear ordinary differential equations. The evolution of the cancer tumour is examined under the variation of the immune cell activation parameter, and the study determines the values of this parameter that cause changes in the dynamics of this evolution; these changes are a consequence of two transcritical bifurcations and a supercritical Hopf bifurcation that exist in the system. These results reveal the range of immune cell activation for which tumour escape or tumour latency, or oscillatory behavior due to the appearance of limit cycles, is achieved. In addition, an optimal value is distinguished for which a minimum number of active immune response cells is sufficient to bring the tumour to a latent state. [ABSTRACT FROM AUTHOR]

Coupled numerical models, which simulate water and energy fluxes in the subsurface–land-surface–atmosphere system in a physically consistent way, are a prerequisite for the analysis and a better understanding of heat and matter exchange fluxes at compartmental boundaries and interdependencies of states across these boundaries. Complete state evolutions generated by such models may be regarded as a proxy of the real world, provided they are run at sufficiently high resolution and incorporate the most important processes. Such a simulated reality can be used to test hypotheses on the functioning of the coupled terrestrial system. Coupled simulation systems, however, face severe problems caused by the vastly different scales of the processes acting in and between the compartments of the terrestrial system, which also hinders comprehensive tests of their realism. We used the Terrestrial Systems Modeling Platform (TerrSysMP), which couples the meteorological Consortium for Small-scale Modeling (COSMO) model, the land-surface Community Land Model (CLM), and the subsurface ParFlow model, to generate a simulated catchment for a regional terrestrial system mimicking the Neckar catchment in southwest Germany, the virtual Neckar catchment. Simulations for this catchment are made for the period 2007–2015 and at a spatial resolution of 400 m for the land surface and subsurface and 1.1 km for the atmosphere. Among a discussion of modeling challenges, the model performance is evaluated based on observations covering several variables of the water cycle. We find that the simulated catchment behaves in many aspects quite close to observations of the real Neckar catchment, e.g., concerning atmospheric boundary-layer height, precipitation, and runoff. But also discrepancies become apparent, both in the ability of the model to correctly simulate some processes which still need improvement, such as overland flow, and in the realism of some observation operators like the satellite-based soil moisture sensors. The whole raw dataset is available for interested users. The dataset described here is available via the CERA database (Schalge et al., 2020): 10.26050/WDCC/Neckar_VCS_v1. [ABSTRACT FROM AUTHOR]

In shallow aquatic environments, sediment is a significant source of monomethylmercury (MMHg) for surface water (SW). High-altitude aquatic ecosystems are characterized by extreme hydro-climatic constraints (e.g., low oxygen and high UV radiation). We studied, during two seasons, the diel cycles of MMHg in SW and sediment porewaters (PW) of Lake Uru Uru (3686 m a.s.l, Bolivia) contaminated by urban and mining activities. Our results show that diel changes in SW MMHg concentrations (up to 1.8 ng L−1) overwhelm seasonal ones, with higher MMHg accumulation during the night-time and the dry season. The calculation of MMHg diffusive fluxes demonstrates that the sediment compartment was the primary source of MMHg to the SW. Most MMHg efflux occurred during the dry season (35.7 ± 17.4 ng m−2 day−1), when the lake was relatively shallow, more eutrophicated, and with the redoxcline located above the sediment–water interface (SWI). Changes in MMHg accumulation in the PWs were attributed to diel redox oscillations around the SWI driving both the bacterial sulfate reduction and bio-methylation. Finally, we highlight that although MMHg loading from the PW to the SW is large, MMHg photodegradation and demethylation by microorganisms control the net MMHg accumulation in the water column. [ABSTRACT FROM AUTHOR]

Byline: Alexander Tubke, Pablo Alvarez De Toledo Saavedra, Jose-Luis Galan Gonzalez Corporate spin-offs combine the rapid growth of new firms with a considerably lower failure rate than other types of start-ups. Lately, their special characteristics have received growing interest, especially with regard to corporate strategy, entrepreneurship and their role within the innovation system. However, literature on spin-offs is sparse and heterogeneous and a common typology is still missing. Up to now, corporate spin-offs have been analysed with rather focused approaches that did not take into account their wide range of characteristics. This paper presents the results of an extensive literature review of corporate spin-offs. It establishes a typology of existing definitions of all spin-off types and presents a comprehensive framework for the investigation of the factors affecting corporate spin-offs. Managers, policymakers and scientists can use the typology and the framework of factors for embedding spin-off phenomena into their full scope, understand the process of their creation and develop successful spin-off strategies. Further, this article can provide a source of inspiration for the development of new research approaches and policies not only directed at spin-offs but all sorts of entrepreneurial activities.

Coupled numerical models, which simulate water and energy fluxes in the subsurface-land surface-atmosphere system in a physically consistent way are a prerequisite for the analysis and a better understanding of heat and matter exchange fluxes at compartmental boundaries and interdependencies of states across these boundaries. Complete state evolutions generated by such models may be regarded as a proxy of the real world, provided they are run at sufficiently high resolution and incorporate the most important processes. Such a virtual reality can be used to test hypotheses on the functioning of the coupled terrestrial system. Coupled simulation systems, however, face severe problems caused by the vastly different scales of the processes acting in and between the compartments of the terrestrial system, which also hinders comprehensive tests of their realism. We used the Terrestrial Systems Modeling Platform TerrSysMP, which couples the meteorological model COSMO, the land-surface model CLM, and the subsurface model ParFlow, to generate a virtual catchment for a regional terrestrial system mimicking the Neckar catchment in southwest Germany. Simulations for this catchment are made for the period 2007-2015, and at a spatial resolution of 400 m for the land surface and subsurface and 1.1 km for the atmosphere. Among a discussion of modelling challenges, the model performance is evaluated based on real observations covering several variables of the water cycle. We find that the simulated (virtual) catchment behaves in many aspects quite close to observations of the real Neckar catchment, e.g. concerning atmospheric boundary-layer height, precipitation, and runoff. But also discrepancies become apparent, both in the ability of the model to correctly simulate some processes which still need improvement such as overland flow, and in the realism of some observation operators like the satellite based soil moisture sensors. The whole raw dataset is available for interested users. The dataset described here is available via the CERA database (Schalge et al., 2020): https://doi.org/10.26050/WDCC/Neckar%5FVCS%5Fv1. [ABSTRACT FROM AUTHOR]