Lethal Ultra-Early Subarachnoid Hemorrhage Due to Rupture of De Novo Aneurysm 5 Months After Primary Aneurysmatic Subarachnoid Hemorrhage

BACKGROUND

Approximately 1% of all patients surviving rupture of a cerebral aneurysm suffer from a second aneurysmatic subarachnoid hemorrhage later in their lives, 61% of which are caused by rupture of a de novo aneurysm. Latency between bleedings is usually many years, and younger patients tend to achieve better outcomes from a second subarachnoid hemorrhage.

CASE DESCRIPTION

We report an unusual case of lethal ultra-early rupture of a de novo aneurysm of the anterior communicating artery only 5 months after the initial subarachnoid hemorrhage and complete coiling in a young, healthy male patient.

CONCLUSION

Despite complete aneurysm obliteration, young age, and good recovery, patients may be subjected to secondary subarachnoid hemorrhages from de novo aneurysms after only a few months of the initial bleeding. Early-control magnetic resonance angiography might hence be advisable.

2D analysis of polydisperse core-shell nanoparticles using analytical ultracentrifugation

Accurate knowledge of the size, density and composition of nanoparticles (NPs) is of major importance for their applications. In this work the hydrodynamic characterization of polydisperse core-shell NPs by means of analytical ultracentrifugation (AUC) is addressed. AUC is one of the most accurate techniques for the characterization of NPs in the liquid phase because it can resolve particle size distributions (PSDs) with unrivaled resolution and detail. Small NPs have to be considered as core-shell systems when dispersed in a liquid since a solvation layer and a stabilizer shell will significantly contribute to the particle's hydrodynamic diameter and effective density. AUC measures the sedimentation and diffusion transport of the analytes, which are affected by the core-shell compositional properties. This work demonstrates that polydisperse and thus widely distributed NPs pose significant challenges for current state-of-the-art data evaluation methods. The existing methods either have insufficient resolution or do not correctly reproduce the core-shell properties. First, we investigate the performance of different data evaluation models by means of simulated data. Then, we propose a new methodology to address the core-shell properties of NPs. This method is based on the parametrically constrained spectrum analysis and offers complete access to the size and effective density of polydisperse NPs. Our study is complemented using experimental data derived for ZnO and CuInS₂ NPs, which do not have a monodisperse PSD. For the first time, the size and effective density of such structures could be resolved with high resolution by means of a two-dimensional AUC analysis approach.

Comparison of eosin-thiazin and Papanicolaou-Shorr staining for endometrial cytologies of broodmares

Introduction: Exfoliative endometrial cytology is an easy and valuable diagnostic tool for the detection of inflammatory processes of the uterus that correlates well to culture results. The practical use of this procedure is limited due to the time-consuming Papanicolaou-Shorr staining technique. In this study the suitability of the rapid eosin-thiazin staining for endometrial smears was investigated. Material and methods: Sample collection was carried out with a guarded culture swab (Knudsen-catheter) in 27 broodmares during routine gynaecological examination. Two smears were prepared from each collection. One was stained according to Papanicolaou-Shorr and the second using the eosin-thiazin method (Hemacolor®, Merck). Specimens with more than 0.5% neutrophil granulocytes were classified as positive for endometritis. The presentability of polymorphonuclear neutrophils (PMN), proportion of positive/negative samples, as well as the PMN contents were compared between the two staining methods. Results: PMN were easily identifiable in both specimens. In Papanicolaou-Shorr stained smears 10 samples showed > 0.5% neutrophil granulocytes (37%), whereas in the eosin-thiazin staining 12 samples were positive (44%). Thus results corresponded in 25 mares (95%). Conclusion: Eosin-thiazin staining is a suitable staining method for endometrial smears of broodmares, which surpassed Papanicolaou-Shorr method in two cases. Clinical relevance: The use of eosin-thiazin staining provides a considerable gain of time and renders endometrial cytology more attractive for routine stud farm practice.

Gestationsketose mit Hyperlipidämie bei einer Alpakastute

Gegenstand und Ziel: Beschrieben werden die klinische Symptomatik, die diagnostische Vorgehensweise und die Therapie bei einer Alpakastute mit hochgradiger Gestationsketose. Material und Methoden: Eine 3-jährige Alpakastute, die sich im 11. Trächtigkeitsmonat befand, wurde wegen einer seit 2 Wochen bestehenden Inappetenz und apathischen Verhaltens in die Klinik eingeliefert. Sie wurde klinisch und labordiagnostisch untersucht und die dabei festgestellte Stoffwechselstörung behandelt. Ergebnisse: Als einzige klinische Symptome zeigte das Tier apathisches Verhalten, Inappetenz sowie Abmagerung. Der hohe Ketonkörpergehalt des Harns sowie das milchig getrübte Serum bei starker Hyperglykämie (27,5 mmol/l), hohen β-Hydroxybutyrat- (13 mmol/l) und NEFA-Werten (4,9 mmol/l) in Verbindung mit erhöhten Leberenzymaktivitäten, metabolischer Azidose (BE: –6,8 mmol/l) und Hypokaliämie (2,3 mmol/l) sprachen für das Vorliegen einer hochgradigen Gestationsketose. Die Infusionstherapie mit Glukose- und Aminosäurelösung sowie Injektionen von Heparin und einem Antibiotikum führten innerhalb von 3 Tagen zu einer deutlichen Verbesserung des Allgemeinbefindens und der Blutwerte. Einen Tag später brachte die Stute ein vitales Fohlen zur Welt. Nach der Entlassung aus der Klinik berichtete der Besitzer, dass das Tier weiterhin ein ungestörtes Allgemeinbefinden zeigte und nach dem Trockenstellen an Körpergewicht zugenommen hatte. Schlussfolgerung und klinische Relevanz: Bei hochtragenden Neuweltkameliden muss – ähnlich wie bei Schafen und Ponys – mit einer Gestationsketose und Hyperlipidämie gerechnet werden. Aufgrund der unspezifischen klinischen Symptomatik, wie Apathie und Inappetenz, sollte in Verdachtsfällen immer eine labordiagnostische Abklärung anhand der Untersuchung von Blut- und Urinproben erfolgen, um die Diagnose rechtzeitig absichern zu können. Therapeutisch ist vor allem eine Infusionstherapie mit Glukoseund Aminosäurelösungen von entscheidender Bedeutung.

An approach to treating a patient with a HeartMate II™ left ventricularassist device in a multiplace hyperbaric chamber: a case report

INTRODUCTION

Left-ventricular assist devices (LVAD) are becoming a common therapy for end-stage heart failure. These devicesare not tested for pressurization in a hyperbaricchamber by the manufacturer. In this article, we present an approach to modify the power supply in order to safely treat a patient with an LVAD.

MATERIALS AND METHODS

Our patient had a HeartMateII™ LVAD and presented for hyperbaric oxygen treatments for severe radiation cystitis. In order to modify this patient's equipment to be compliant with NFPA6 safety standards we made several modifications. In brief, this included eliminating the usage of lithium-ion batteries, modifying the cord to be compatible with Fink chamber outlets, and enclosing the power module in a nitrogen purge. We then used a mock circulatory system to test our modifications and make sure the LVAD continued to have appropriate flow rates. We then conducted training for staff and developed a disaster plan should the LVAD fail at any point.

RESULTS

Once we felt comfortable with the modifications and had a plan developed should any problems arise, we then proceeded to treat our patient in the hyperbaric chamber. He successfully underwent 44 hyperbaric treatments for radiation cystitis without complications.

CONCLUSION

This case is the second reported patient in the literature with an LVAD that was successfully treated in a multiplace hyperbaric chamber. As LVADs become increasingly popular to manage heart failure, more patients with these devices will present for hyperbaric treatments. With a few modifications, an LVAD patient can be safely and successfully treated in a hyperbaric chamber.

Advanced Multiwavelength Detection in Analytical Ultracentrifugation

This work highlights significant advancements in detector hardware and software for multiwavelength analytical ultracentrifugation (MWL-AUC) experiments, demonstrating improvement in both the spectral performance and UV capabilities of the instrument. The hardware is an extension of the Open AUC MWL detector developed in academia and first introduced in 2006 by Bhattacharya et al. Additional modifications as well as new analytical methods available for MWL data have since been reported. The present work describes new and continuing improvements to the MWL detector, including mirror source and imaging optics, UV sensitive acquisition modes and revised data acquisition software. The marked improvement of experimental data promises to provide access to increasingly complex systems, especially semiconductor nanoparticles, synthetic polymers, biopolymers, and other chromophores absorbing in the UV. Details of the detection system and components are examined to reveal the influences on data quality and to guide further developments. The benchmark comparisons of data quality across platforms will also serve as a reference guide for evaluation of forthcoming commercial absorbance optics.

Brownian dynamics simulations of analytical ultracentrifugation experiments exhibiting hydrodynamic and thermodynamic non-ideality

Hydrodynamic and thermodynamic non-ideality are important phenomena when studying concentrated and interacting systems in analytical ultracentrifugation (AUC). Here we present an extended Brownian Dynamics (BD) based algorithm which incorporates hydrodynamic and thermodynamic non-ideality. It can serve as an independent and versatile approach for the theoretical description of interparticulate interactions in AUC, as it allows tracking the trajectory of individual particles. Concentration dependencies of the sedimentation and diffusion coefficient have been implemented and validated for the extended BD model. For monodisperse systems, it is shown that profiles obtained by BD are in excellent agreement with well-established Lamm equation solvers. Moreover, important limits and restrictions of current Lamm equation based analysis methods are discussed. In particular, BD allows modeling and evaluation of AUC data of non-ideal polydisperse systems. This is relevant as most nanoparticulate systems are polydisperse in size. Here, a simulation for a polydisperse system including concentration effects is presented for the first time.

Determination of the length and diameter of nanorods by a combination of analytical ultracentrifugation and scanning mobility particle sizer

A combination of orthogonal measurement techniques is utilized in this study to predict the average lengths and diameters of colloidal nanorods. Sedimentation coefficient distributions and electrical mobility distributions obtained from analytical ultracentrifugation and a scanning mobility particle sizer, respectively, are used for the hydrodynamic correlation. The method is validated theoretically and application to Au and ZnO nanorod samples is shown. The results demonstrate that the combination of both measurement techniques is an excellent method for the two-dimensional characterization of nanorods.

Continuous synthesis of CuInS2 quantum dots

The impact of reactor type on synthesis parameters and disperse properties.

Simultaneous Identification of Spectral Properties and Sizes of Multiple Particles in Solution with Subnanometer Resolution

We report an unsurpassed solution characterization technique based on analytical ultracentrifugation, which demonstrates exceptional potential for resolving particle sizes in solution with sub-nm resolution. We achieve this improvement in resolution by simultaneously measuring UV/Vis spectra while hydrodynamically separating individual components in the mixture. By equipping an analytical ultracentrifuge with a novel multi-wavelength detector, we are adding a new spectral discovery dimension to traditional hydrodynamic characterization, and amplify the information obtained by orders of magnitude. We demonstrate the power of this technique by characterizing unpurified CdTe nanoparticle samples, avoiding tedious and often impossible purification and fractionation of nanoparticles into apparently monodisperse fractions. With this approach, we have for the first time identified the pure spectral properties and band-gap positions of discrete species present in the CdTe mixture.

Using carbon nanodots as inexpensive and environmentally friendly sensitizers in mesoscopic solar cells

We discuss the use of carbon nanodots (CNDs) as sensitizers in mesoscopic solar cells. The CNDs are synthesized using a one-step, bottom-up microwave approach with citric acid, urea, and formic acid as precursors in aqueous media. Their light-harvesting capabilities can be tuned by adjusting the synthetic parameters. Comprehensive spectroscopic and theoretical studies allow us to rationalize the nature of their absorption features. Promising power conversion efficiencies (η) of 0.24% can be achieved from these cheap and eco-friendly sensitizers by optimizing the solar-cell assembly process. Interestingly, we found that extending the light absorption towards longer wavelengths does not necessarily improve the performance of the solar cells, since the longer-wavelength absorption features hardly contribute to the cells' photo-action spectra, so that the overall power conversion efficiency is actually worse. The origin of the lower performance is corroborated in transient absorption spectroscopy and photovoltage decay measurements. Our work points, on one hand, to the limits of as-synthesized CNDs as photosensitizers and, on the other hand, to possible improvements.

Dynamic range multiwavelength particle characterization using analytical ultracentrifugation

We demonstrate how a sophisticated data analysis methodology enables us to perform multiwavelength evaluations of dynamic rotor speed gradient experiments obtained by analytical ultracentrifugation equipped with a multiwavelength detector. Our data evaluation tool HDR-MULTIFIT allows for the accurate analysis of sedimentation coefficient distributions which can be converted to particle size distributions. By means of multiwavelength evaluation, species dependent extinction spectra can be determined even for complex mixtures. Moreover, optical and hydrodynamic properties can be correlated for spherical particles of known optical properties applying multiwavelength evaluation and Mie's theory leading to a significant increase in the dynamic range of the experiment. We provide the theoretical background about the operation principle of our methodology and compare the performance of the multiwavelength analysis to the conventional single wavelength analysis as it is applied in turbidity analysis. We validate our technique using NIST traceable reference particles and show that our technique is universally applicable to materials of known and unknown optical properties, thus clearly extending the possibilities of particle analysis.