Biomechanical Analysis of Age-Dependent Changes in Fontan Power Loss.

The hemodynamics in Fontan patients with single ventricles rely on favorable flow and energetics, especially in the absence of a subpulmonary ventricle. Age-related changes in energetics for extracardiac and lateral tunnel Fontan procedures are not well understood. Vorticity (VOR) and viscous dissipation rate (VDR) are two descriptors that can provide insights into flow dynamics and dissipative areas in Fontan pathways, potentially contributing to power loss. This study examined power loss and its correlation with spatio-temporal flow descriptors (vorticity and VDR). Data from 414 Fontan patients were used to establish a relationship between the superior vena cava (SVC) to inferior vena cava (IVC) flow ratio and age. Computational flow modeling was conducted for both extracardiac conduits (ECC, n = 16) and lateral tunnels (LT, n = 25) at different caval inflow ratios of 2, 1, and 0.5 that corresponded with ages 3, 8, and 15+. In both cohorts, vorticity and VDR correlated well with PL, but ECC cohort exhibited a slightly stronger correlation for PL-VOR (>0.83) and PL-VDR (>0.89) than that for LT cohort (>0.76 and > 0.77, respectively) at all ages. Our data also suggested that absolute and indexed PL increase (p < 0.02) non-linearly as caval inflow changes with age and are highly patient-specific. Comparison of indexed power loss between our ECC and LT cohort showed that while ECC had a slightly higher median PL for all 3 caval inflow ratio examined (3.3, 8.3, 15.3) as opposed to (2.7, 7.6, 14.8), these differences were statistically non-significant. Lastly, there was a consistent rise in pressure gradient across the TCPC with age-related increase in IVC flows for both ECC and LT Fontan patient cohort. Our study provided hemodynamic insights into Fontan energetics and how they are impacted by age-dependent change in caval inflow. This workflow may help assess the long-term sustainability of the Fontan circulation and inform the design of more efficient Fontan conduits.

Impact of Age-related change in Caval Flow Ratio on Hepatic Flow Distribution in Fontan.

Background: The Fontan operation is a palliative technique for patients born with single ventricle heart disease. The superior vena cava (SVC), inferior vena cava (IVC), and hepatic veins are connected to the pulmonary arteries in a total cavopulmonary connection by an extracardiac (EC) conduit or a lateral tunnel (LT) connection. A balanced hepatic flow distribution (HFD) to both lungs is essential to prevent pulmonary arteriovenous malformations and cyanosis. HFD is highly dependent on the local hemodynamics. Objective: The effect of age-related changes in caval inflows on HFD was evaluated using cardiac MRI (CMR) data and patient-specific computational fluid dynamics (CFD) modeling. Methods: SVC and IVC flow from 414 Fontan patients were collected to establish a relationship between SVC:IVC flow ratio and age. CFD modeling was performed in 60 (30 EC and 30 LT) patient models to quantify the HFD that corresponded to patient ages of 3, 8, and 15 years, respectively. Results: SVC:IVC flow ratio inverted at ∼8 years of age, indicating a clear shift to lower body flow predominance. Our data showed that variation of HFD in response to age-related changes in caval inflows (SVC:IVC = 2,1, and 0.5 corresponded to ages 3, 8, and 15+ respectively) was not significant for EC but statistically significant for LT cohorts. For all three caval inflow ratios, a positive correlation existed between the IVC flow distribution to both the lungs and the HFD. However, as the SVC:IVC ratio changed from 2→0.5 (age 3→15+), the correlation's strength decreased from 0.87→0.64, due to potential flow perturbation as IVC flow momentum increased. Conclusion: Our analysis provided quantitative insights into the impact of the changing caval inflows on Fontan's long-term HFD, highlighting the importance of including SVC:IVC variations over time to understand Fontan's long-term hemodynamics. These findings broaden our understanding of Fontan hemodynamics and patient outcomes. Clinical Perspective: With improvement in standard of care and management of single ventricle patients with Fontan physiology, the population of adults with Fontan circulation is increasing. Consequently, there is a clinical need to comprehend the impact of patient growth on Fontan hemodynamics. Using CMR data, we were able to quantify the relationship between changing caval inflows and somatic growth. We then used patient-specific computational flow modeling to quantify how this relationship affected the distribution of long-term hepatic flow in extracardiac and lateral tunnel Fontan types. Our findings demonstrated the significance of including SVC:IVC changes over time in CFD modeling to learn more about the long-term hemodynamics of Fontan. Fontan surgical approaches are increasingly planned and optimized using computational flow modeling. For a patient undergoing a Fontan procedure, the workflow presented in this study that takes into account the variations in Caval inflows over time can aid in predicting the long-term hemodynamics in a planned Fontan pathway.

Human sensory response to acetone/air mixtures.

The release of organic compounds from building products may influence the perceived air quality in the indoor environment. Consequently, building products are assessed for chemical emissions and for the acceptability of emitted odors. A procedure for odor evaluations in test chambers is described by the standard ISO 16000-28. A panel of eight or more trained subjects directly determines the perceived intensity Π (unit pi) of an air sample via diffusers. For the training of the panelists, a comparative Π-scale is applied. The panelists can use acetone/air mixtures in a concentration range between 20 mg/m(3) (0 pi) and 320 mg/m(3) (15 pi) as reference. However, the training and calibration procedure itself can substantially contribute to the method uncertainty. This concerns the assumed odor threshold of acetone, the variability of panelist responses, and the analytical determination of acetone concentrations in air with online methods as well as the influence of the diffuser geometry and the airflow profile.

A Census of X-ray gas in NGC 1068: Results from 450ks of Chandra HETG Observations.

We present models for the X-ray spectrum of the Seyfert 2 galaxy NGC 1068. These are fitted to data obtained using the High Energy Transmission Grating (HETG) on the Chandra X-ray observatory. The data show line and radiative recombination continuum (RRC) emission from a broad range of ions and elements. The models explore the importance of excitation processes for these lines including photoionization followed by recombination, radiative excitation by absorption of continuum radiation and inner shell fluorescence. The models show that the relative importance of these processes depends on the conditions in the emitting gas, and that no single emitting component can fit the entire spectrum. In particular, the relative importance of radiative excitation and photoionization/recombination differs according to the element and ion stage emitting the line. This in turn implies a diversity of values for the ionization parameter of the various components of gas responsible for the emission, ranging from log(ξ)=1 - 3. Using this, we obtain an estimate for the total amount of gas responsible for the observed emission. The mass flux through the region included in the HETG extraction region is approximately 0.3 M⊙ yr-1 assuming ordered flow at the speed characterizing the line widths. This can be compared with what is known about this object from other techniques.

Chemical composition of burnt smell caused by accidental fires: environmental contaminants.

The chemical composition of the odors typical of fires has recently been deciphered. Basically the constituents are mixtures of acetophenone, benzyl alcohol, hydroxylated derivatives of benzaldehyde, methoxylated and/or alkylated phenols and naphthalene. This finding makes it possible to develop objective, practical analytic measurement methods for the burnt smell as a contribution to improving fire damage assessment and remediation monitoring. With the aid of an artificially produced burnt smell and a panel of testers the odor detection threshold of a test mixture was determined olfactometrically to 2 µg m⁻³. Using a defined burnt-smell atmosphere in a test chamber, analytical methods with active sampling, the adsorbents XAD 7 and TENAX TA, and GC/MS measurement were then optimized and tested with a view to being able to carry out sensitive quantitative measurement of burnt smells. A further practical method with particular application to the qualitative characterization of this odor is based on the use of a new SPME (solid-phase microextraction) field sampler with DVB/CAR/PDMS (divinylbenzene/Carboxen™/polydimethylsiloxane) fibers.

[Subarachnoid pleural fistula and subsequent pneumocephalus as complication of vertebral body replacement of the thoracic spine]. / Pleurospinale Fistel und konsekutiver Pneumatozephalus als Komplikation eines Wirbelkörperersatzes an der Brustwirbelsäule.

A pneumocephalus caused by a subarachnoid pleural fistula following spinal surgery using an anterior approach is a rare complication, especially in vertebral body replacement. We report the case of a 66-year-old male suffering from metastatic prostatic cancer of the thoracic spine who underwent replacement of a vertebral body using a transthoracic approach. A pneumocephalus occurred 4 weeks postoperatively resulting in delirium.

Surface-catalysed reactions on pollutant-removing building products for indoor use.

In order to evaluate the potential for emission of secondary reaction products from building materials designed to remove pollutants from indoor air, four samples of ceiling tiles--three commercially available and one custom-made--were investigated in chamber experiments. The chambers were irradiated with artificial light simulating indoor conditions and formaldehyde as well as several VOCs (2-butanone, n-butanol, toluene, hexanal, n- butylacetate, 2-butoxyethanol, alpha-pinene, benzaldehyde, n-decane, limonene and 1,2-dichlorobenzene) were added. Depending on the individual substrate-substance combination, it was possible to identify secondary emissions, e.g. formaldehyde, furfural, acetophenone, n-butylbutyrate, n-butyl-i-butyrate, n-butylpropionate, 4-heptanone, acetic acid, i-butyraldehyde and crotonaldehyde. These were generated by cleavage, hydrolysis, rearrangement or radical reactions. Some of these reactions also occurred with samples not containing photocatalysts. All these secondary emissions have to be taken seriously into account when evaluating the performance of materials designed to remove pollutants from indoor air, as they can prove detrimental to human health.

High-power, (AlGaIn)(AsSb) semiconductor disk laser at 2.0 microm.

We report a high-power (AlGaIn)(AsSb) semiconductor disk laser emitting around 2 microm. With a diamond heat spreader used for thermal management, a maximum output power of just over 5 W and slope efficiencies of over 25% were demonstrated. The output wavelength was tunable over an 80 nm range centered at 1.98 microm. The beam propagation parameter (M2) was measured to be in the range of 1.1 to 1.4 for output powers up to 3 W.

Tunable, Single-frequency, Diode-pumped 2.3mum VECSEL.

We report high-performance single-frequency operation of a directly diode-pumped GaSb-based vertical-external-cavity surface-emitting laser (VECSEL) at 2.3mum. Tunability of 70nm and a maximum single frequency output of 0.68W is demonstrated.

Integrated modelling for the evaluation of infiltration effects.

The objective of the present study is the estimation of the potential benefits of sewer pipe rehabilitation for the performance of the drainage system and the wastewater treatment plant (WWTP) as well as for the receiving water quality. The relation of sewer system status and the infiltration rate is assessed based on statistical analysis of 470 km of CCTV (Closed Circuit Television) inspected sewers of the city of Dresden. The potential reduction of infiltration rates and the consequent performance improvements of the urban wastewater system are simulated as a function of rehabilitation activities in the network. The integrated model is applied to an artificial system with input from a real sewer network. In this paper, the general design of the integrated model and its data requirements are presented. For an exemplary study, the consequences of the simulations are discussed with respect to the prioritisation of rehabilitation activities in the network.

[Food-dependent Cushing syndrome of long standing with mild clinical features]. / Nahrungsabhängiges Cushing-Syndrom mit langer Anamnese und moderater Klinik.

HISTORY AND CLINICAL FINDINGS: A 40-year-old woman complained of weight gain for 10 years. Because of this, she yearly went on a excessive weight reduction diet with weight loss of up to 12 kg. Nevertheless, a total weight gain of 15 kg as well as changing degrees of hypertension, muscular weakness and severe depression were registered during this long period. For 5 years ecchymosis and for 2 years oligomenorrhoea as well as oedema had become evident. Recently large macronodular adrenal glands were found on routine abdominal ultrasound. At the time of clinical investigation early this year she presented with relatively mild Cushing features, such as moon face, central obesity, hirsutism, ecchymosis and hypertension. INVESTIGATIONS: Endocrine testing demonstrated suppressed plasma ACTH, low to normal plasma cortisol after overnight fasting and an inverse diurnal rhythm. During 24 hours of fasting plasma cortisol levels and free urinary cortisol excretion were within normal range, but highly elevated under normal food intake. Plasma cortisol levels increased dramatically in response to a lipid-rich meal (5.6-fold), to a protein-rich meal (6.6-fold) and to oral glucose (3.7-fold). Increases in plasma cortisol were closely correlated to increases of gastric inhibitory polypeptide (GIP) concentrations. Subcutaneous injection of octreotide completely inhibited the plasma cortisol and GIP response to oral glucose. Plasma ACTH and cortisol levels did not increase after CRH administration, but fasting plasma cortisol promptly increased after ACTH stimulation. Non-fasting plasma cortisol levels and free urinary cortisol excretion were not suppressed by high doses of dexamethasone. Abdominal computed tomography showed macronodular enlargement of both adrenal glands. TREATMENT AND COURSE: The patient underwent bilateral adrenalectomy. Postoperatively, she was treated with replacement doses of hydrocortisone and fludrocortisone. All Cushing features have regressed, a normal menstrual cycle and normal plasma ACTH concentrations have become evident. CONCLUSION: This case report not only presents a very rare cause of Cushing's syndrome--food-dependent or gastric inhibitory peptide (GIP)-dependent hypercortisolism--but it also demonstrates a special course of this disease of relatively long duration. Severe adrenal hyperplasia contrasted with mild clinical symptoms obviously caused by frequent periods of weight reduction diet. Considering this moderate clinical course it might well be that food-dependent hypercortisolism is more frequent than supposed, but not diagnosed owing to relatively mild clinical symptoms.

[Category distribution and prognostic significance of operationalized psychodynamic diagnosis. Initial experiences with "OPD-1" in inpatient psychotherapy]. / Kategorienhäufigkeit und prognostische Bedeutung einer operationalisierten psychodynamischen Diagnostik. Erste Erfahrungen mit der "OPD-1" im stationären Rahmen.

The paper describes the application of the system of "operationalized psychodynamic diagnosis" (OPD) which was developed in a multicentric effort during the recent years. The system is used for the classification of videotape-recorded interviews with 30 patients prior to inpatient psychotherapy. The classification system allows the diagnostic assessment of the patients' illness behaviour, their interpersonal relationships, their conflicts, psychic structure and their symptoms. The aim of the study was a description of the patient group as well as a test of the relationship between diagnostic features and treatment outcome following several months of inpatient group psychotherapy. The study confirms the practicability of the OPD-system and shows that the description of the patient group seems to be plausible and valid. Single diagnostic categories seem to be useful for the prognosis of treatment outcome, especially structural features, but also characteristics of the patients' illness behaviour and their sensitivity for conflicts.