Imaging intact human organs with local resolution of cellular structures using hierarchical phase-contrast tomography.

Imaging intact human organs from the organ to the cellular scale in three dimensions is a goal of biomedical imaging. To meet this challenge, we developed hierarchical phase-contrast tomography (HiP-CT), an X-ray phase propagation technique using the European Synchrotron Radiation Facility (ESRF)'s Extremely Brilliant Source (EBS). The spatial coherence of the ESRF-EBS combined with our beamline equipment, sample preparation and scanning developments enabled us to perform non-destructive, three-dimensional (3D) scans with hierarchically increasing resolution at any location in whole human organs. We applied HiP-CT to image five intact human organ types: brain, lung, heart, kidney and spleen. HiP-CT provided a structural overview of each whole organ followed by multiple higher-resolution volumes of interest, capturing organotypic functional units and certain individual specialized cells within intact human organs. We demonstrate the potential applications of HiP-CT through quantification and morphometry of glomeruli in an intact human kidney and identification of regional changes in the tissue architecture in a lung from a deceased donor with coronavirus disease 2019 (COVID-19).

Multiscale three-dimensional imaging of intact human organs down to the cellular scale using hierarchical phase-contrast tomography.

Human organs are complex, three-dimensional and multiscale systems. Spatially mapping the human body down through its hierarchy, from entire organs to their individual functional units and specialised cells, is a major obstacle to fully understanding health and disease. To meet this challenge, we developed hierarchical phase-contrast tomography (HiP-CT), an X-ray phase propagation technique utilising the European Synchrotron Radiation Facility's Extremely Brilliant Source: the world's first high-energy 4 th generation X-ray source. HiP-CT enabled three-dimensional and non-destructive imaging at near-micron resolution in soft tissues at one hundred thousand times the voxel size whilst maintaining the organ's structure. We applied HiP-CT to image five intact human parenchymal organs: brain, lung, heart, kidney and spleen. These were hierarchically assessed with HiP-CT, providing a structural overview of the whole organ alongside detail of the organ's individual functional units and cells. The potential applications of HiP-CT were demonstrated through quantification and morphometry of glomeruli in an intact human kidney, and identification of regional changes to the architecture of the air-tissue interface and alveolar morphology in the lung of a deceased COVID-19 patient. Overall, we show that HiP-CT is a powerful tool which can provide a comprehensive picture of structural information for whole intact human organs, encompassing precise details on functional units and their constituent cells to better understand human health and disease.

[Ruptured Abdominal Aortic Aneurysm - Results and Prognostic Factors at a Certified Centre of Vascular Surgery]. / Das rupturierte abdominale Aortenaneurysma ­ Ergebnisse und prognostische Faktoren an einem gefäßchirurgischen Zentrum.

Introduction: Although the perioperative management has been optimised over the past few decades, there has not been a remarkable improvement in the mortality rates of patients with a ruptured abdominal aortic aneurysm (rAAA). The aim of this retrospective trial was to define pre-, intra- and postoperative parameters which influence the perioperative and long-term outcome of patients and which can be modified by the operating team. Methods: A retrospective database analysis was performed in 49 patients who had undergone an operation of rAAA in our certified centre of vascular surgery between the beginning of 2006 and the end of 2012. The minimal follow-up period was 30 months. The statistical analysis was done univariately using the Kaplan-Meier method and a log-rank-test, and multivariately with the Cox model. Results: Intrahospital mortality was 40.8 %, perioperative mortality (30 postoperative days) was 28.9 %. The survival rate for 1 year was 52.4 %; the survival rate for 5 years was 45.3 %. In the univariate analysis, significant differences in the early postoperative survival rates were found depending on preoperative systolic blood pressure, preoperative haemoglobin (< 10 vs. ≥ 10 g/dl), the intraoperative need of blood and frozen plasma transfusions, type of perforation, type of AAA, the need for further surgical interventions, postoperative MOF, acute kidney failure and postoperative septicaemia. The late survival rates were significantly influenced by the type of perforation and AAA, pre-existing coronary disease and diabetes mellitus in fully identified patients discharged from hospital (n = 27). In the multivariate analysis pursuant to the Cox model, patients with pre-existing coronary disease had a 3.9-fold higher relative risk to die after the operation of rAAA, while patients with a free perforation of the rAA had a 10-fold higher relative risk. Conclusion: The high mortality of rAAA is caused by haemorrhagic shock and its complications, which are mostly non-surgical. Therapeutic efforts should focus on those perioperative parameters which can be modified by the treating teams. Alongside the centralisation of rAAA in high-volume-departments of vascular surgery, the systematic sonographic screening for asymptomatic AAA in the population older than 65 years should be enforced. A possible advantage of EVAR in rAAA has yet to be shown by trials in progress such as IMPROVE, AJAX and RCAR.

Mixing effects in the crystallization of supercooled quantum binary liquids.

By means of Raman spectroscopy of liquid microjets, we have investigated the crystallization process of supercooled quantum liquid mixtures composed of parahydrogen (pH2) or orthodeuterium (oD2) diluted with small amounts of neon. We show that the introduction of the Ne impurities affects the crystallization kinetics in terms of a significant reduction of the measured pH2 and oD2 crystal growth rates, similarly to what found in our previous work on supercooled pH2-oD2 liquid mixtures [Kühnel et al., Phys. Rev. B 89, 180201(R) (2014)]. Our experimental results, in combination with path-integral simulations of the supercooled liquid mixtures, suggest in particular a correlation between the measured growth rates and the ratio of the effective particle sizes originating from quantum delocalization effects. We further show that the crystalline structure of the mixtures is also affected to a large extent by the presence of the Ne impurities, which likely initiate the freezing process through the formation of Ne-rich crystallites.

Compact cryogenic source of periodic hydrogen and argon droplet beams for relativistic laser-plasma generation.

We present a cryogenic source of periodic streams of micrometer-sized hydrogen and argon droplets as ideal mass-limited target systems for fundamental intense laser-driven plasma applications. The highly compact design combined with a high temporal and spatial droplet stability makes our injector ideally suited for experiments using state-of-the-art high-power lasers in which a precise synchronization between the laser pulses and the droplets is mandatory. We show this by irradiating argon droplets with multi-terawatt pulses.

Interatomic Coulombic decay following photoionization of the helium dimer: observation of vibrational structure.

Using synchrotron radiation we simultaneously ionize and excite one helium atom of a helium dimer (He2) in a shakeup process. The populated states of the dimer ion [i.e., He(*+)(n = 2, 3) - He] are found to deexcite via interatomic Coulombic decay. This leads to the emission of a second electron from the neutral site and a subsequent Coulomb explosion. In this Letter we present a measurement of the momenta of fragments that are created during this reaction. The electron energy distribution and the kinetic energy release of the two He+ ions show pronounced oscillations which we attribute to the structure of the vibrational wave function of the dimer ion.

Single photon double ionization of the helium dimer.

We show that a single photon can ionize the two helium atoms of the helium dimer in a distance up to 10 A. The energy sharing among the electrons, the angular distributions of the ions and electrons, as well as comparison with electron impact data for helium atoms suggest a knockoff type double ionization process. The Coulomb explosion imaging of He2 provides a direct view of the nuclear wave function of this by far most extended and most diffuse of all naturally existing molecules.