Publications by authors named "Christoph Hofer"

82 Publications

Spontaneous activity of the mitochondrial apoptosis pathway drives chromosomal defects, the appearance of micronuclei and cancer metastasis through the Caspase-Activated DNAse.

Cell Death Dis 2022 Apr 7;13(4):315. Epub 2022 Apr 7.

Institute of Medical Microbiology and Hygiene, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany.

Micronuclei are DNA-containing structures separate from the nucleus found in cancer cells. Micronuclei are recognized by the immune sensor axis cGAS/STING, driving cancer metastasis. The mitochondrial apoptosis apparatus can be experimentally triggered to a non-apoptotic level, and this can drive the appearance of micronuclei through the Caspase-activated DNAse (CAD). We tested whether spontaneously appearing micronuclei in cancer cells are linked to sub-lethal apoptotic signals. Inhibition of mitochondrial apoptosis or of CAD reduced the number of micronuclei in tumor cell lines as well as the number of chromosomal misalignments in tumor cells and intestinal organoids. Blockade of mitochondrial apoptosis or deletion of CAD reduced, while experimental activation CAD, STING-dependently, enhanced aggressive growth of tumor cells in vitro. Deletion of CAD from human cancer cells reduced metastasis in xenograft models. CAD-deficient cells displayed a substantially altered gene-expression profile, and a CAD-associated gene expression 'signature' strongly predicted survival in cancer patients. Thus, low-level activity in the mitochondrial apoptosis apparatus operates through CAD-dependent gene-induction and STING-activation and has substantial impact on metastasis in cancer.
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http://dx.doi.org/10.1038/s41419-022-04768-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8990075PMC
April 2022

What sports activity levels can be achieved in the long-term after major lower extremity amputation for malignant tumors? - A minimum follow-up of twenty years.

Orthop Traumatol Surg Res 2022 06 2;108(4):103229. Epub 2022 Feb 2.

Department of Orthopaedics and Trauma Surgery, Medical University of Vienna, Vienna, Austria. Electronic address:

Background: It is well-known that exercise through sports and physical activity has beneficial effects on health. After lower extremity amputation, low rates of participation in sports activities have been shown. So far, there is only limited scientific long-term information concerning sports activity and feasible types of sports in patients with lower extremity amputations due to malignant tumors. This study sought to provide very long-term information about the following questions: (1) What sports activity levels can be achieved after lower extremity amputation due to a malignant tumor? (2) What are feasible types of sports? (3) Is the University of California Los Angeles (UCLA) Activity Score influenced by patient's age, the age at the time of surgery and the amount of prosthesis sockets used to date?

Hypothesis: Patients with lower extremity amputation due to a malignant tumor cannot regularly participate in moderate sports activities (UCLA Activity Score≥6) in the very long-term.

Materials And Methods: In a retrospective questionnaire survey, 21 former patients (seven females, 14 males; median age: 60.5years [range: 33-74]) who underwent an amputation of the lower extremity (14 transfemoral, four knee disarticulations, three transtibial) from 1961 to 1993 due to a malignant tumor were interviewed. The median follow-up was 41.1years (range: 23-55). The patients were interviewed about types of sports, frequencies and durations of sports sessions at the time of the last follow-up, as well as retrospectively. Sports activity levels were then assessed based on the UCLA Activity Score. Demographic background, data on amputation level, histological results, prosthetic devices and revision surgeries were collected.

Results: Seven patients (33%) were still regularly exercising at least moderate sports activities at the last follow-up, including one patient regularly participating in impact sports. The preoperative median UCLA Activity Score of 9 (range: 2-10) decreased to 5 (range: 2-10) at the last follow-up (p<0.001). Swimming (13 patients, seven on a regular basis), cycling (seven), downhill skiing (five) and hiking (four) were among the most common feasible types of sports. Increasing age had a negative influence on the UCLA Activity Score [95% CI (-0.034, -0.006); R=-0.020; SD=0.0074; p=0.007].

Conclusion: After a major amputation in the lower extremity due to a malignant tumor, high activity levels by practicing types of sports such as downhill skiing, are achievable. In the very long-term, a regular participation in at least moderate activities, such as swimming, is possible. Programs for physical and sports activities, based on recommendations drawn from long-term experience, are necessary and should be individually tailored to amputees and their limitations.

Level Of Evidence: IV.
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http://dx.doi.org/10.1016/j.otsr.2022.103229DOI Listing
June 2022

Aligned Stacking of Nanopatterned 2D Materials for High-Resolution 3D Device Fabrication.

ACS Nano 2022 Feb 1;16(2):1836-1846. Epub 2022 Feb 1.

Institute of Applied Physics, Eberhard Karls University of Tuebingen, Auf der Morgenstelle 10, D-72076, Tuebingen, Germany.

Two-dimensional materials can be combined by placing individual layers on top of each other, so that they are bound only by their van der Waals interaction. The sequence of layers can be chosen arbitrarily, enabling an essentially atomic-level control of the material and thereby a wide choice of properties along one dimension. However, simultaneous control over the structure in the in-plane directions is so far still rather limited. Here, we combine spatially controlled modifications of 2D materials, using focused electron irradiation or electron beam induced etching, with the layer-by-layer assembly of van der Waals heterostructures. The presented assembly process makes it possible to structure each layer with an arbitrary pattern prior to the assembly into the heterostructure. Moreover, it enables a stacking of the layers with accurate lateral alignment, with an accuracy of currently 10 nm, under observation in an electron microscope. Together, this enables the fabrication of almost arbitrary 3D structures with highest spatial resolution.
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http://dx.doi.org/10.1021/acsnano.1c09122DOI Listing
February 2022

Toward Exotic Layered Materials: 2D Cuprous Iodide.

Adv Mater 2022 Mar 19;34(9):e2106922. Epub 2022 Jan 19.

Faculty of Physics, University of Vienna, Vienna, 1090, Austria.

Heterostructures composed of 2D materials are already opening many new possibilities in such fields of technology as electronics and magnonics, but far more could be achieved if the number and diversity of 2D materials were increased. So far, only a few dozen 2D crystals have been extracted from materials that exhibit a layered phase in ambient conditions, omitting entirely the large number of layered materials that may exist at other temperatures and pressures. This work demonstrates how such structures can be stabilized in 2D van der Waals (vdw) stacks under room temperature via growing them directly in graphene encapsulation by using graphene oxide as the template material. Specifically, an ambient stable 2D structure of copper and iodine, a material that normally only occurs in layered form at elevated temperatures between 645 and 675 K, is produced. The results establish a simple route to the production of more exotic phases of materials that would otherwise be difficult or impossible to stabilize for experiments in ambient.
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http://dx.doi.org/10.1002/adma.202106922DOI Listing
March 2022

Atom-by-atom chemical identification from scanning transmission electron microscopy images in presence of noise and residual aberrations.

Ultramicroscopy 2021 Aug 8;227:113292. Epub 2021 May 8.

Institute for Applied Physics, Eberhard Karls University of Tübingen, Auf der Morgenstelle 10, D-72076, Tübingen, Germany; Natural and Medical Sciences Institute at the University of Tübingen, Markwiesenstr. 55, D-72770 Reutlingen, Germany; Faculty of Physics, University of Vienna, Boltzmanng. 5, 1090 Vienna, Austria.

The simple dependence of the intensity in annular dark field scanning transmission electron microscopy images on the atomic number provides (to some extent) chemical information about the sample, and even allows an elemental identification in the case of light-element single-layer samples. However, the intensity of individual atoms and atomic columns is affected by residual aberrations and the confidence of an identification is limited by the available signal to noise. Here, we show that matching a simulation to an experimental image by iterative optimization provides a reliable analysis of atomic intensities even in presence of residual non-round aberrations. We compare our new method with other established approaches demonstrating its high reliability for images recorded at limited dose and with different aberrations. This is of particular relevance for analyzing moderately beam-sensitive materials, such as most 2D materials, where the limited sample stability often makes it difficult to obtain spectroscopic information at atomic resolution.
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http://dx.doi.org/10.1016/j.ultramic.2021.113292DOI Listing
August 2021

Cross-cultural adaption, translation and validation of the Toronto extremity salvage score (TESS) for patients in German-speaking countries.

Wien Klin Wochenschr 2021 Jun 27;133(11-12):536-542. Epub 2021 Apr 27.

Department of Orthopedics and Trauma Surgery, Division of Orthopedics, Medical University of Vienna, Vienna, Austria.

Objective: The preferred treatment for malignant bone and soft tissue tumors is limb salvage surgery; the Toronto extremity salvage score (TESS) is commonly used to measure physical functioning of the affected extremity. The aims of this study were to translate and culturally adapt the German version of the TESS, as well as to explore its convergent reliability, validity and re-test reliability.

Study Design: Patients (n = 50) 32 lower extremity (LE) and 18 upper extremity (UE) were asked to fill out the German TESS two times (t1: clinical visit, t2: regular email) and the SF-36 once.

Methods: The TESS questionnaires were translated from English into German, back translated into English, and culturally adapted. The reliability was assessed with Cronbach's alpha (α). The validity was measured with the SF-36 physical component score and TESS using the Spearman rank correlation coefficient (r). Furthermore, the test-retest reliability was calculated with the intraclass correlation coefficient (ICC).

Results: Internal consistency for both questionnaires was excellent (LE t1: α = 0.924, t2: α = 0.952; UE t1: α = 0.957, t2: α = 0.898). A statistically significant correlation was found between the SF-36 physical component scale and the German TESS (LE r = 0.741, UE r = 0.713). The ICC between baseline (t1) and re-test (t2) was 0.952 and 0.871 for the lower and upper extremities, respectively.

Conclusion: Initial evidence demonstrated that the German TESS is a valid and reliable instrument for use with patients after surgical treatment of malignant bone or soft tissue sarcoma.
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http://dx.doi.org/10.1007/s00508-021-01865-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8195924PMC
June 2021

Analysis of anaesthesia services to calculate national need and supply of anaesthetics in Switzerland during the COVID-19 pandemic.

PLoS One 2021 19;16(3):e0248997. Epub 2021 Mar 19.

Swiss Society for Anaesthesiology and Resuscitation (SSAR), Committee on Data and Quality Management, Berne, Switzerland.

Background: In Switzerland, details of current anaesthesia practice are unknown. However, they are urgently needed to manage anaesthesia drug supply in times of drug shortages due to the pandemic.

Methods: We surveyed all Swiss anaesthesia institutions in April 2020 to determine their annual anaesthesia activity. Together with a detailed analysis on anaesthetic drug use of a large, representative Swiss anaesthesia index institution, calculations and projections for the annual need of anaesthetics in Switzerland were made. Only those drugs have been analysed that are either being used very frequently or that have been classified critical with regard to their supply by the pharmacy of the index institution or the Swiss Federal Office of Public Health.

Results: The response rate to our questionnaire was 98%. Out of the present 188 Swiss anaesthesia institutions, 185 responded. In Switzerland, the annual number of anaesthesias was 1'071'054 (12'445 per 100'000 inhabitants) with a mean anaesthesia time of 2.03 hours. Teaching hospitals (n = 54) performed more than half (n = 572'231) and non-teaching hospitals (n = 103) provided almost half of all anaesthesias (n = 412'531). Thereby, private hospitals conducted a total of 290'690 anaesthesias. Finally, office-based anaesthesia institutions with mainly outpatients (n = 31) administered 86'292 anaesthesias. Regarding type of anaesthesia provided, two thirds were general anaesthesias (42% total intravenous, 17% inhalation, 8% combined), 20% regional and 12% monitored anaesthesia care. Projecting for example the annual need for propofol in anaesthesia, Switzerland requires 48'573 L of propofol 1% which corresponds to 5'644 L propofol 1% per 100'000 inhabitants every year.

Conclusions: To actively manage anaesthesia drug supply in the context of the current pandemic, it is mandatory to have a detailed understanding of the number and types of anaesthesias provided. On this basis, the Swiss annual consumption of anaesthetics could be projected and the replenishment organized.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0248997PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7978279PMC
April 2021

How Common Are Chronic Residual Limb Pain, Phantom Pain, and Back Pain More Than 20 Years After Lower Limb Amputation for Malignant Tumors?

Clin Orthop Relat Res 2021 09;479(9):2036-2044

Department of Orthopaedic Surgery, Medical University of Vienna, Vienna, Austria.

Background: After major lower limb amputation, persistent pain is common, with up to 85% of patients reporting recurring phantom or residual-limb pain. Although pain management is an important factor of quality of life in patients with lower limb amputations, there are few long-term data regarding the frequency of persistent pain and how it impacts prosthesis use.

Questions/purposes: (1) How prevalent are different types of pain at long-term follow-up after amputation for malignant tumors? (2) What association do different pain types have with daily prosthesis use?

Methods: Between 1961 and 1995, 124 major amputations for malignant tumors were performed at one center in Austria in patients (1) who spoke German and (2) whose surgical date resulted in the possibility of a minimum follow-up time of 20 years at the time of this survey; those patients were considered potentially eligible for this retrospective study. The indications for major amputation were to achieve local tumor control in limbs that the surgeon deemed unsalvageable without amputation. Of those 124 patients, 71% (88) had died, 9% (11) could not be reached, and 3% (4) declined to participate. Thus, 58% (21 of 36) of those living at the time of this study and who underwent lower limb amputation between 1961 and 1993 with a median (range) follow-up duration of 41 years (23 to 55) completed a standardized questionnaire, including an assessment of pain and daily prosthesis use during the year before the survey. Phantom pain, residual limb pain, and back pain were each further subclassified into pain frequency, intensity, and restrictions in activities of daily living (ADL) due to the specific pain form and rated on a 5- (pain frequency) and 10-point (pain intensity, restrictions in ADL) numerical rating scale. Before multivariate regression analysis, daily prosthesis use was correlated with pain parameters using Spearman correlation testing.

Results: Seventeen of 21 patients reported phantom limb and back pain, and 15 patients reported residual limb pain in the past year. Median (range) phantom pain intensity was 7 (1 to 10) points, median residual limb pain intensity was 4 (1 to 9) points, and median back pain intensity was 5 (1 to 10) points. After controlling for relevant confounding variables such as age at amputation, age at survey, and stump length, we found that less intense residual limb pain (defined on a 10-point scale with 1 representing no pain at all and 10 representing extremely strong pain [95% CI 0.3 to 1.0]; r = 0.8; p = 0.003) was associated with greater daily prosthesis use. Higher amputation levels showed a decreased daily prosthesis use compared with patients with lower amputation levels (defined as transfemoral amputation versus knee disarticulation versus transtibial amputation [95% CI 0.3 to 5.1]; r = 0.5; p = 0.03).

Conclusion: Decades after surgery, many patients with lower limb amputations experience pain that restricts them in terms of ADLs and decreases their daily prosthesis use. This information supports the need for regular residual limb inspections and careful prosthesis fitting even at long-term follow-up, as effective prosthesis fitting is a modifiable cause of residual limb pain. Future studies evaluating long-term treatment effects of pain relief surgery and therapeutic alternatives to conservative pain treatments should be performed, as these approaches may help alleviate pain in patients with refractory postamputation pain.

Level Of Evidence: Level IV, therapeutic study.
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http://dx.doi.org/10.1097/CORR.0000000000001725DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8373555PMC
September 2021

Radiative lifetime-encoded unicolour security tags using perovskite nanocrystals.

Nat Commun 2021 02 12;12(1):981. Epub 2021 Feb 12.

Institute of Inorganic Chemistry, Department of Chemistry and Applied Bioscience, ETH Zürich, Zürich, Switzerland.

Traditional fluorescence-based tags, used for anticounterfeiting, rely on primitive pattern matching and visual identification; additional covert security features such as fluorescent lifetime or pattern masking are advantageous if fraud is to be deterred. Herein, we present an electrohydrodynamically printed unicolour multi-fluorescent-lifetime security tag system composed of lifetime-tunable lead-halide perovskite nanocrystals that can be deciphered with both existing time-correlated single-photon counting fluorescence-lifetime imaging microscopy and a novel time-of-flight prototype. We find that unicolour or matching emission wavelength materials can be prepared through cation-engineering with the partial substitution of formamidinium for ethylenediammonium to generate "hollow" formamidinium lead bromide perovskite nanocrystals; these materials can be successfully printed into fluorescence-lifetime-encoded-quick-read tags that are protected from conventional readers. Furthermore, we also demonstrate that a portable, cost-effective time-of-flight fluorescence-lifetime imaging prototype can also decipher these codes. A single comprehensive approach combining these innovations may be eventually deployed to protect both producers and consumers.
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http://dx.doi.org/10.1038/s41467-021-21214-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7881120PMC
February 2021

Comparative Genomics of Species to Reveal Diversity, Potential for Secondary Metabolites and Heavy Metal Resistance.

Front Microbiol 2020 4;11:1869. Epub 2020 Aug 4.

Bioresouces Unit, Center for Health & Bioresources, AIT Austrian Institute of Technology GmbH, Tulln, Austria.

species have been isolated from a wide range of hosts and environments, including heavy metal-contaminated sites. Here, we present a comprehensive analysis on the phylogenetic distribution and the genetic potential of 70 belonging to 20 different species isolated from heavy metal-contaminated and non-contaminated sites with particular attention to secondary metabolites gene clusters. The analyzed species are divided in three main functional clades. They share a small core genome (331 gene families covering basic functions) pointing to high genetic diversity. The most common secondary metabolite gene clusters encode pathways for the production of terpenoids, type III polyketide synthases and non-ribosomal peptide synthetases, potentially responsible of the synthesis of siderophore-like compounds. tests showed that many strains produce siderophores, ACC deaminase, auxins (IAA) and are able to solubilize phosphate. isolates from heavy metal contaminated sites are on average more resistant to heavy metals and harbor more genes related to metal homeostasis (e.g., metalloregulators). On the other hand, the ability to increase the metal mobility in a contaminated soil through the secretion of specific molecules seems to be widespread among all. Despite the widespread capacity of strains to mobilize several metals, plants inoculated with selected isolates showed only slightly increased iron concentrations, whereas concentrations of zinc, cadmium and lead were decreased.
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http://dx.doi.org/10.3389/fmicb.2020.01869DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7438953PMC
August 2020

Tailoring Electronic and Magnetic Properties of Graphene by Phosphorus Doping.

ACS Appl Mater Interfaces 2020 Jul 15;12(30):34074-34085. Epub 2020 Jul 15.

Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University Olomouc, Šlechtitelů 27, 78371 Olomouc , Czech Republic.

The electronic and magnetic properties of graphene can be modulated by doping it with other elements, especially those with a different number of valence electrons. In this article, we first provide a three-dimensional reconstruction of the atomic structure of a phosphorus substitution in graphene using aberration-corrected scanning transmission electron microscopy. Turning then to theoretical calculations based on the density functional theory (DFT), we show that doping phosphorus in various bonding configurations can induce magnetism in graphene. Our simulations reveal that the electronic and magnetic properties of P-doped (Gr-P) and/or phosphono-functionalized graphene (Gr-POH) can be controlled by both the phosphorus concentration and configurations, ultimately leading to ferromagnetic (FM) and/or antiferromagnetic (AFM) features with the transition temperature up to room temperature. We also calculate core-level binding energies of variously bonded P to facilitate X-ray photoelectron spectroscopy-based identification of its chemical form present in P-doped graphene-based structures. These results may enable the design of graphene-based organic magnets with tailored properties for future magnetic or spintronic applications.
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http://dx.doi.org/10.1021/acsami.0c07564DOI Listing
July 2020

Prediction of Cognitive Decline in Temporal Lobe Epilepsy and Mild Cognitive Impairment by EEG, MRI, and Neuropsychology.

Comput Intell Neurosci 2020 20;2020:8915961. Epub 2020 May 20.

Department of Neurology, Centre for Cognitive Neuroscience, Paracelsus Medical University, Salzburg, Austria.

Cognitive decline is a severe concern of patients with mild cognitive impairment. Also, in patients with temporal lobe epilepsy, memory problems are a frequently encountered problem with potential progression. On the background of a unifying hypothesis for cognitive decline, we merged knowledge from dementia and epilepsy research in order to identify biomarkers with a high predictive value for cognitive decline across and beyond these groups that can be fed into intelligent systems. We prospectively assessed patients with temporal lobe epilepsy ( = 9), mild cognitive impairment ( = 19), and subjective cognitive complaints ( = 4) and healthy controls ( = 18). All had structural cerebral MRI, EEG at rest and during declarative verbal memory performance, and a neuropsychological assessment which was repeated after 18 months. Cognitive decline was defined as significant change on neuropsychological subscales. We extracted volumetric and shape features from MRI and brain network measures from EEG and fed these features alongside a baseline testing in neuropsychology into a machine learning framework with feature subset selection and 5-fold cross validation. Out of 50 patients, 27 had a decline over time in executive functions, 23 in visual-verbal memory, 23 in divided attention, and 7 patients had an increase in depression scores. The best sensitivity/specificity for decline was 72%/82% for executive functions based on a feature combination from MRI volumetry and EEG partial coherence during recall of memories; 95%/74% for visual-verbal memory by combination of MRI-wavelet features and neuropsychology; 84%/76% for divided attention by combination of MRI-wavelet features and neuropsychology; and 81%/90% for increase of depression by combination of EEG partial directed coherence factor at rest and neuropsychology. Combining information from EEG, MRI, and neuropsychology in order to predict neuropsychological changes in a heterogeneous population could create a more general model of cognitive performance decline.
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http://dx.doi.org/10.1155/2020/8915961DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7256687PMC
April 2021

An empirical assessment of appearance descriptors applied to MRI for automated diagnosis of TLE and MCI.

Comput Biol Med 2020 02 23;117:103592. Epub 2019 Dec 23.

Department of Computer Science, University of Salzburg, Austria. Electronic address:

Objective: Differential diagnosis of mild cognitive impairment MCI and temporal lobe epilepsy TLE is a debated issue, specifically because these conditions may coincide in the elderly population. We evaluate automated differential diagnosis based on characteristics derived from structural brain MRI of different brain regions.

Methods: In 22 healthy controls, 19 patients with MCI, and 17 patients with TLE we used scale invariant feature transform (SIFT), local binary patterns (LBP), and wavelet-based features and investigate their predictive performance for MCI and TLE.

Results: The classification based on SIFT features resulted in an accuracy of 81% of MCI vs. TLE and reasonable generalizability. Local binary patterns yielded satisfactory diagnostic performance with up to 94.74% sensitivity and 88.24% specificity in the right Thalamus for the distinction of MCI vs. TLE, but with limited generalizable. Wavelet features yielded similar results as LPB with 94.74% sensitivity and 82.35% specificity but generalize better.

Significance: Features beyond volume analysis are a valid approach when applied to specific regions of the brain. Most significant information could be extracted from the thalamus, frontal gyri, and temporal regions, among others. These results suggest that analysis of changes of the central nervous system should not be limited to the most typical regions of interest such as the hippocampus and parahippocampal areas. Region-independent approaches can add considerable information for diagnosis. We emphasize the need to characterize generalizability in future studies, as our results demonstrate that not doing so can lead to overestimation of classification results.

Limitations: The data used within this study allows for separation of MCI and TLE subjects using a simple age threshold. While we present a strong indication that the presented method is age-invariant and therefore agnostic to this situation, new data would be needed for a rigorous empirical assessment of this findings.
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http://dx.doi.org/10.1016/j.compbiomed.2019.103592DOI Listing
February 2020

Discontinuous Galerkin isogeometric analysis for segmentations generating overlapping regions.

Appl Anal 2021 6;100(13):2749-2776. Epub 2019 Dec 6.

Johann Radon Institute for Computational and Applied Mathematics (RICAM), Austrian Academy of Sciences, Linz, Austria.

In the Isogeometric Analysis (IGA) framework, the computational domain has very often a multipatch representation. The multipatch domain can be obtained by a volume segmentation of a boundary represented domain, e.g. provided by a Computer Aided Design model. Typically, small gaps and overlapping regions can appear at the patch interfaces of such multipatch representations. In the current work, we consider multipatch representations having only small overlapping regions between the patches. We develop a Discontinuous Galerkin (DG)-IGA method that can be immediately applied to these representations. Our method appropriately connects the fluxes of the one face of the overlapping region with the flux of the opposite face. We provide a theoretical justification of our approach by splitting the whole error into two components: the first is related to the incorrect representation of the patches (consistency error) and the second to the approximation properties of the IGA space. We show bounds for both components of the error. We verify the theoretical error estimates in a series of numerical examples.
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http://dx.doi.org/10.1080/00036811.2019.1698724DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8437101PMC
December 2019

Direct imaging of light-element impurities in graphene reveals triple-coordinated oxygen.

Nat Commun 2019 10 8;10(1):4570. Epub 2019 Oct 8.

Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090, Vienna, Austria.

Along with hydrogen, carbon, nitrogen and oxygen are the arguably most important elements for organic chemistry. Due to their rich variety of possible bonding configurations, they can form a staggering number of compounds. Here, we present a detailed analysis of nitrogen and oxygen bonding configurations in a defective carbon (graphene) lattice. Using aberration-corrected scanning transmission electron microscopy and single-atom electron energy loss spectroscopy, we directly imaged oxygen atoms in graphene oxide, as well as nitrogen atoms implanted into graphene. The collected data allows us to compare nitrogen and oxygen bonding configurations, showing clear differences between the two elements. As expected, nitrogen forms either two or three bonds with neighboring carbon atoms, with three bonds being the preferred configuration. Oxygen, by contrast, tends to bind with only two carbon atoms. Remarkably, however, triple-coordinated oxygen with three carbon neighbors is also observed, a configuration that is exceedingly rare in organic compounds.
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http://dx.doi.org/10.1038/s41467-019-12537-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6783479PMC
October 2019

High-resolution remote thermometry and thermography using luminescent low-dimensional tin-halide perovskites.

Nat Mater 2019 Aug 1;18(8):846-852. Epub 2019 Jul 1.

Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland.

Although metal-halide perovskites have recently revolutionized research in optoelectronics through a unique combination of performance and synthetic simplicity, their low-dimensional counterparts can further expand the field with hitherto unknown and practically useful optical functionalities. In this context, we present the strong temperature dependence of the photoluminescence lifetime of low-dimensional, perovskite-like tin-halides and apply this property to thermal imaging. The photoluminescence lifetimes are governed by the heat-assisted de-trapping of self-trapped excitons, and their values can be varied over several orders of magnitude by adjusting the temperature (up to 20 ns °C). Typically, this sensitive range spans up to 100 °C, and it is both compound-specific and shown to be compositionally and structurally tunable from -100 to 110 °C going from [C(NH)]SnBr to CsSnBr and (CNHI)SnI. Finally, through the implementation of cost-effective hardware for fluorescence lifetime imaging, based on time-of-flight technology, these thermoluminophores have been used to record thermographic videos with high spatial and thermal resolution.
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http://dx.doi.org/10.1038/s41563-019-0416-2DOI Listing
August 2019

Interchangeability of cardiac output measurements between non-invasive photoplethysmography and bolus thermodilution: A systematic review and individual patient data meta-analysis.

Anaesth Crit Care Pain Med 2020 02 4;39(1):75-85. Epub 2019 Jun 4.

Anesthesiology and Critical Care Department, Amiens University Hospital, avenue René-Laennec, 80054 Amiens, France; Research unit on Simplified Care of Complex Surgical Patients, Jules-Verne University of Picardy, University Centre for Health Research (CURS), chemin du Thil, 80025 Amiens cedex, France.

Background: Continuous non-invasive cardiac output devices using digital photoplethysmography (PPG) are widely available for bedside use, but their interchangeability with reference methods has not yet been evaluated in a systematic review and patient data meta-analysis.

Methods: A systematic review and meta-analysis of studies comparing non-invasive cardiac output monitoring using PPG with the invasive bolus thermodilution method was performed. With ethical approval, all published studies from the PUBMED, Embase, Scopus, Web of Science, and Google Scholar databases from January 1, 2010 to January 1, 2018 were included. From these analysed studies, individual patient data were interpreted using the interchangeability methods for both absolute values and changes in cardiac output measurements.

Results: Ten studies comparing PPG and bolus thermodilution in the operating room and intensive care settings were included. The interchangeability rate (95% CI) was 37% (24-48) (n=1350 pairs of measurements). The interchangeability rate was poorer with the CNAP device (CNSystems, Graz, Austria) [18% (17-20)] than with the Clearsight (Edwards Lifesciences, Irvine, CA) device [33% (31-34), P<0.0001], for patients receiving norepinephrine [19% (17-20) vs. 33% (32-34), P<0.0001], and for patients with low mean arterial pressure (<65mmHg) [26% (23-29) vs. 30% (29-31), P<0.0001]. Among the 1009 comparisons of the changes in cardiac output between both methods, 561 (56%) were interpretable with a trend interchangeability rate at 24% (12-36).

Conclusions: Cardiac output measurements using PPG were not interchangeable with bolus thermodilution in regard to both absolute values and changes in cardiac output measurements, and should be used with caution in clinical practice.

Trial Registration: PROSPERO ID CRD42018089513.
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http://dx.doi.org/10.1016/j.accpm.2019.05.007DOI Listing
February 2020

Engineering single-atom dynamics with electron irradiation.

Sci Adv 2019 May 17;5(5):eaav2252. Epub 2019 May 17.

Department of Nuclear Science and Engineering and Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.

Atomic engineering is envisioned to involve selectively inducing the desired dynamics of single atoms and combining these steps for larger-scale assemblies. Here, we focus on the first part by surveying the single-step dynamics of graphene dopants, primarily phosphorus, caused by electron irradiation both in experiment and simulation, and develop a theory for describing the probabilities of competing configurational outcomes depending on the postcollision momentum vector of the primary knock-on atom. The predicted branching ratio of configurational transformations agrees well with our atomically resolved experiments. This suggests a way for biasing the dynamics toward desired outcomes, paving the road for designing and further upscaling atomic engineering using electron irradiation.
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http://dx.doi.org/10.1126/sciadv.aav2252DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6524980PMC
May 2019

Optimisation of Perioperative Cardiovascular Management to Improve Surgical Outcome II (OPTIMISE II) trial: study protocol for a multicentre international trial of cardiac output-guided fluid therapy with low-dose inotrope infusion compared with usual care in patients undergoing major elective gastrointestinal surgery.

BMJ Open 2019 01 15;9(1):e023455. Epub 2019 Jan 15.

Queen Mary University of London, London, UK.

Introduction: Postoperative morbidity and mortality in older patients with comorbidities undergoing gastrointestinal surgery are a major burden on healthcare systems. Infections after surgery are common in such patients, prolonging hospitalisation and reducing postoperative short-term and long-term survival. Optimal management of perioperative intravenous fluids and inotropic drugs may reduce infection rates and improve outcomes from surgery. Previous small trials of cardiac-output-guided haemodynamic therapy algorithms suggested a modest reduction in postoperative morbidity. A large definitive trial is needed to confirm or refute this and inform widespread clinical practice.

Methods: The Optimisation of Perioperative Cardiovascular Management to Improve Surgical Outcome II (OPTIMISE II) trial is a multicentre, international, parallel group, open, randomised controlled trial. 2502 high-risk patients undergoing major elective gastrointestinal surgery will be randomly allocated in a 1:1 ratio using minimisation to minimally invasive cardiac output monitoring to guide protocolised administration of intravenous fluid combined with low-dose inotrope infusion, or usual care. The trial intervention will be carried out during and for 4 hours after surgery. The primary outcome is postoperative infection of Clavien-Dindo grade II or higher within 30 days of randomisation. Participants and those delivering the intervention will not be blinded to treatment allocation; however, outcome assessors will be blinded when feasible. Participant recruitment started in January 2017 and is scheduled to last 3 years, within 50 hospitals worldwide.

Ethics/dissemination: The OPTIMISE II trial has been approved by the UK National Research Ethics Service and has been approved by responsible ethics committees in all participating countries. The findings will be disseminated through publication in a widely accessible peer-reviewed scientific journal.

Trial Registration Number: ISRCTN39653756.
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http://dx.doi.org/10.1136/bmjopen-2018-023455DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6341180PMC
January 2019

Atomic-Scale Deformations at the Interface of a Mixed-Dimensional van der Waals Heterostructure.

ACS Nano 2018 Aug 23;12(8):8512-8519. Epub 2018 Jul 23.

University of Vienna , Faculty of Physics , 1090 Vienna , Austria.

Molecular self-assembly due to chemical interactions is the basis of bottom-up nanofabrication, whereas weaker intermolecular forces dominate on the scale of macromolecules. Recent advances in synthesis and characterization have brought increasing attention to two- and mixed-dimensional heterostructures, and it has been recognized that van der Waals (vdW) forces within the structure may have a significant impact on their morphology. Here, we suspend single-walled carbon nanotubes (SWCNTs) on graphene to create a model system for the study of a 1D-2D molecular interface through atomic-resolution scanning transmission electron microscopy observations. When brought into contact, the radial deformation of SWCNTs and the emergence of long-range linear grooves in graphene revealed by the three-dimensional reconstruction of the heterostructure are observed. These topographic features are strain-correlated but show no sensitivity to carbon nanotube helicity, electronic structure, or stacking order. Finally, despite the random deposition of the nanotubes, we show that the competition between strain and vdW forces results in aligned carbon-carbon interfaces spanning hundreds of nanometers.
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http://dx.doi.org/10.1021/acsnano.8b04050DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6117744PMC
August 2018

Prediction of fluid responsiveness in mechanically ventilated cardiac surgical patients: the performance of seven different functional hemodynamic parameters.

BMC Anesthesiol 2018 05 22;18(1):55. Epub 2018 May 22.

Institute of Anesthesiology and Intensive Care Medicine, Triemli City Hospital Zurich, Birmensdorferstr. 497, 8063, Zurich, Switzerland.

Background: Functional hemodynamic parameters such as stroke volume and pulse pressure variation (SVV and PPV) have been shown to be reliable predictors of fluid responsiveness in mechanically ventilated patients. Today, different minimally- and non-invasive hemodynamic monitoring systems measure functional hemodynamic parameters. Although some of these parameters are described by the same name, they differ in their measurement technique and thus may provide different results. We aimed to test the performance of seven functional hemodynamic parameters simultaneously in the same clinical setting.

Methods: Hemodynamic measurements were done in 30 cardiac surgery patients that were mechanically ventilated. Before and after a standardized intravenous fluid bolus, hemodynamics were measured by the following monitoring systems: PiCCOplus (SVV, PPV), LiDCO (SVV, PPV), FloTrac (SVV), Philips Intellivue (PPV) and Masimo pulse oximeter (pleth variability index, PVI). Prediction of fluid responsiveness was tested by calculation of receiver operating characteristic (ROC) curves including a gray zone approach and compared using Fisher's Z-Test.

Results: Fluid administration resulted in an increase in cardiac output, while all functional hemodynamic parameters decreased. A wide range of areas under the ROC-curve (AUC's) was observed: AUC-SVV = 0.91, AUC-PPV = 0.88, AUC-SVV = 0.78, AUC-PPV = 0.89, AUC-SVV = 0.87, AUC-PPV = 0.92 and AUC-PVI = 0.68. Optimal threshold values for prediction of fluid responsiveness ranged between 9.5 and 17.5%. Lowest threshold values were observed for SVV, highest for PVI.

Conclusion: All functional hemodynamic parameters tested except for PVI showed that their use allows a reliable identification of potential fluid responders. PVI however, may not be suitable after cardiac surgery to predict fluid responsiveness.

Trial Registration: NCT02571465 , registered on October 7th, 2015 (retrospectively registered).
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http://dx.doi.org/10.1186/s12871-018-0520-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5964892PMC
May 2018

Reliability of Passive Leg Raising, Stroke Volume Variation and Pulse Pressure Variation to Predict Fluid Responsiveness During Weaning From Mechanical Ventilation After Cardiac Surgery: A Prospective, Observational Study.

Turk J Anaesthesiol Reanim 2018 Apr 1;46(2):108-115. Epub 2018 Apr 1.

Institute of Anaesthesiology and Intensive Care Medicine, Triemli Hospital Zurich, Switzerland.

Objective: During assisted ventilation and spontaneous breathing, functional haemodynamic parameters, including stroke volume variation (SVV) and pulse pressure variation (PPV), are of limited value to predict fluid responsiveness, and the passive leg raising (PLR) manoeuvre has been advocated as a surrogate method. We aimed to study the predictive value of SVV, PPV and PLR for fluid responsiveness during weaning from mechanical ventilation after cardiac surgery.

Methods: Haemodynamic variables and fluid responsiveness were assessed in 34 patients. Upon arrival at the intensive care unit, measurements were performed during continuous mandatory ventilation (CMV) and spontaneous breathing with pressure support (PSV) and after extubation (SPONT). The prediction of a positive fluid responsiveness (defined as stroke volume increase >15% after fluid administration) was tested by calculating the specific receiver operating characteristic (ROC) curves.

Results: A significant increase in stroke volumes was observed during CMV, PSV and SPONT after fluid administration. There were 19 fluid responders (55.9%) during CMV, with 22 (64.7%) and 13 (40.6%) during PSV and SPONT, respectively. The predictive value for a positive fluid responsiveness (area under the ROC curve) for SVV was 0.88, 0.70 and 0.56; was 0.83, 0.69 and 0.48 for PPV; was 0.72, 0.74 and 0.70 for PLR during CMV, PSV and SPONT, respectively.

Conclusion: During mechanical ventilation, adequate prediction of fluid responsiveness using SVV and PPV was observed. However, during spontaneous breathing, the reliability of SVV and PPV was poor. In this period, PLR as a surrogate was able to predict fluid responsiveness better than SVV or PPV but was less reliable than previously reported.
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http://dx.doi.org/10.5152/TJAR.2018.29577DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5937456PMC
April 2018

Factors Affecting Volume Changes of the Somatosensory Cortex in Patients with Spinal Cord Injury: To Be Considered for Future Neuroprosthetic Design.

Front Neurol 2017 11;8:662. Epub 2017 Dec 11.

Department of Neurology, Christian Doppler Medical Centre and Centre for Cognitive Neuroscience, Paracelsus Medical University Salzburg, Salzburg, Austria.

Spinal cord injury (SCI) leads to severe chronic disability, but also to secondary adaptive changes upstream to the injury in the brain which are most likely induced due to the lack of afferent information. These neuroplastic changes are a potential target for innovative therapies such as neuroprostheses, e.g., by stimulation in order to evoke sensation or in order to suppress phantom limb pain. Diverging results on gray matter atrophy have been reported in patients with SCI. Detectability of atrophy seems to depend on the selection of the regions of interest, while whole-brain approaches are not sensitive enough. In this study, we discussed previous research approaches and analyzed differential atrophic changes in incomplete SCI using manual segmentation of the somatosensory cortex. Patients with incomplete SCI (ASIA C-D), with cervical (N = 5) and thoracic (N = 6) injury were included. Time since injury was ≤12 months in 7 patients, and 144, 152, 216, and 312 months in the other patients. Age at the injury was ≤26 years in 4 patients and ≥50 years in 7 patients. A sample of 12 healthy controls was included in the study. In contrast to all previous studies that used voxel-based morphometry, we performed manual segmentation of the somatosensory cortex in the postcentral gyrus from structural magnetic resonance images and normalized the calculated volumes against the sum of volumes of an automated whole-head segmentation. Volumes were smaller in patients than in controls ( = 0.011), and as a tendency, female patients had smaller volumes than male patients ( = 0.017, uncorrected). No effects of duration (subacute vs. chronic), level of lesion (cervical vs. thoracic), region (left vs. right S1), and age at onset (≤26 vs. ≥50 years) was found. Our results demonstrate volume loss of S1 in incomplete SCI and encourage further research with larger sample sizes on volumetric changes in the acute and chronic stage of SCI, in order to document the moderating effect of type and location of injury on neuroplastic changes. A better understanding of neuroplastic changes in the sensorimotor cortex after SCI and its interaction with sex is needed in order to develop efficient rehabilitative interventions and neuroprosthetic technologies.
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http://dx.doi.org/10.3389/fneur.2017.00662DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5732216PMC
December 2017

Accuracy, Precision, and Trending of 4 Pulse Wave Analysis Techniques in the Postoperative Period.

J Cardiothorac Vasc Anesth 2018 04 7;32(2):715-722. Epub 2017 Sep 7.

Institute of Anaesthesiology and Intensive Care Medicine, Triemli Hospital Zurich, Zurich, Switzerland.

Objective: The aim of this study was to analyze the accuracy, precision, and trending ability of the following 4 pulse wave analysis devices to measure continuous cardiac output: PiCCO ([PCCO]; Pulsion Medical System, Munich, Germany); LiDCO ([LCCO]; LiDCO Ltd, London, UK); FloTrac/Vigileo ([FCCO]; Edwards Lifesciences, Irvine, CA); and Nexfin ([NCCO]; BMEYE, Amsterdam, The Netherlands).

Design: Prospective, observational clinical study.

Setting: Intensive care unit of a single-center, teaching hospital.

Participants: The study comprised 22 adult patients after elective coronary artery bypass surgery.

Interventions: Three measurement cycles were performed in all patient durings their immediate postoperative intensive care stay before and after fluid loading. Hemodynamic measurements were performed 5 minutes before and immediately after the administration of 500 mL colloidal fluid over 20 minutes.

Measurements And Main Results: PCCO, LCCO, FCCO, and NCCO were assessed and compared with cardiac output derived from intermittent transpulmonary thermodilution (ICO). One hundred thirty-two matched sets of data were available for analysis. Bland-Altman analysis using linear mixed effects models with random effects for patient and trial revealed a mean bias ±2 standard deviation (%error) of -0.86 ± 1.41 L/min (34.9%) for PCCO-ICO, -0.26 ± 2.81 L/min (46.3%) for LCCO-ICO, -0.28 ± 2.39 L/min (43.7%) for FCCO-ICO, and -0.93 ± 2.25 L/min (34.6%) for NCCO-ICO. Bland-Altman plots without adjustment for repeated measurements and replicates yielded considerably larger limits of agreement. Trend analysis for all techniques did not meet criteria for acceptable performance.

Conclusions: All 4 tested devices using pulse wave analysis for measuring cardiac output failed to meet current criteria for meaningful and adequate accuracy, precision, and trending ability in cardiac output monitoring.
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http://dx.doi.org/10.1053/j.jvca.2017.09.006DOI Listing
April 2018

Automated Image Acquisition for Low-Dose STEM at Atomic Resolution.

Microsc Microanal 2017 08 23;23(4):809-817. Epub 2017 May 23.

Faculty of Physics,University of Vienna,Boltzmanngasse 5,1090 Vienna,Austria.

Beam damage is a major limitation in electron microscopy that becomes increasingly severe at higher resolution. One possible route to circumvent radiation damage, which forms the basis for single-particle electron microscopy and related techniques, is to distribute the dose over many identical copies of an object. For the acquisition of low-dose data, ideally no dose should be applied to the region of interest before the acquisition of data. We present an automated approach that can collect large amounts of data efficiently by acquiring images in a user-defined area-of-interest with atomic resolution. We demonstrate that the stage mechanics of the Nion UltraSTEM, combined with an intelligent algorithm to move the sample, allow the automated acquisition of atomically resolved images from micron-sized areas of a graphene substrate. Moving the sample stage automatically in a regular pattern over the area-of-interest enables the collection of data from pristine sample regions without exposing them to the electron beam before recording an image. Therefore, it is possible to obtain data with minimal dose (no prior exposure during focusing), which is only limited by the minimum signal needed for data processing. This enables us to minimize beam-induced damage in the sample and to acquire large data sets within a reasonable amount of time.
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http://dx.doi.org/10.1017/S1431927617000575DOI Listing
August 2017

Complete genome sequence of the heavy metal resistant bacterium AR33 and comparison with related .

Stand Genomic Sci 2017 5;12. Epub 2017 Jan 5.

AIT Austrian Institute of Technology, Health and Environment Department, Konrad-Lorenz-Straße 24, A-3430 Tulln, Austria.

AR33 is a Gram-positive, rod-shaped and motile bacterium belonging to the family in the phylum that was isolated from a former zinc/lead mining and processing site in Austria. In this study, the whole genome was sequenced and assembled combining sequences obtained from Illumina MiSeq and Sanger sequencing. The assembly resulted in the complete genome sequence which is 4,373,124 bp long and has a GC content of 70.1%. Furthermore, we performed a comparative genomic analysis with other related organisms: 6 spp., 4 spp. and 2 other members of the class .
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http://dx.doi.org/10.1186/s40793-016-0217-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5217419PMC
January 2017

Isotope analysis in the transmission electron microscope.

Nat Commun 2016 10 10;7:13040. Epub 2016 Oct 10.

Faculty of Physics, University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090 Vienna, Austria.

The Ångström-sized probe of the scanning transmission electron microscope can visualize and collect spectra from single atoms. This can unambiguously resolve the chemical structure of materials, but not their isotopic composition. Here we differentiate between two isotopes of the same element by quantifying how likely the energetic imaging electrons are to eject atoms. First, we measure the displacement probability in graphene grown from either C or C and describe the process using a quantum mechanical model of lattice vibrations coupled with density functional theory simulations. We then test our spatial resolution in a mixed sample by ejecting individual atoms from nanoscale areas spanning an interface region that is far from atomically sharp, mapping the isotope concentration with a precision better than 20%. Although we use a scanning instrument, our method may be applicable to any atomic resolution transmission electron microscope and to other low-dimensional materials.
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http://dx.doi.org/10.1038/ncomms13040DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5476802PMC
October 2016

Evaluation of a New Sonoclot Device for Heparin Management in Cardiac Surgery.

Clin Appl Thromb Hemost 2017 Jan 27;23(1):20-26. Epub 2016 May 27.

Institute of Anaesthesiology and Intensive Care Medicine, Triemli City Hospital, Zurich, Switzerland

Background: Sonoclot is used to measure kaolin-based activated clotting time (kACT) for heparin management. Apart from measuring kACT, the device assesses the patient's coagulation status by glass bead-activated tests (gbACTs; measuring also clot rate [CR] and platelet function [PF]). Recently, a new version of the Sonoclot has been released, and the redesign may result in performance changes. The aim of this study was to evaluate and compare the performance of the new (S2) and the previous (S1) Sonoclot.

Methods: The S1 was used in the routine management of 30 patients undergoing elective cardiac surgery. Blood samples were taken at baseline (T1), after heparin administration (200 U/kg, 100 U/kg; T2 and T3), during cardiopulmonary bypass (T4), after protamine infusion (T5), and before intensive care unit transfer (T6). Kaolin-based activated clotting time and gbACTs were measured in duplicate by both the old and the new device and performance compared by Bland-Altman analysis and percentage error calculation.

Results: A total of 300 kACT and 180 gbACTs were available. Bland-Altman analysis for kACT revealed that S2 consistently reported results in shorter time compared to S1 (overall = -14.7%). Comparing S2 and S1, the glass bead-activated tests showed mean percentage differences of -18.9% (gbACTs), +37.4% (CR), and -3.7% (PF).

Conclusion: Since clotting is faster in the new S2 compared to S1, shorter clotting times have to be considered in clinical practice. The use of S2 kACT in heparin management will result in higher heparin and protamine dosing unless heparin kACT target values are adjusted to correct for the differences in results between S1 and S2.
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http://dx.doi.org/10.1177/1076029616651148DOI Listing
January 2017

Less invasive hemodynamic monitoring in critically ill patients.

Intensive Care Med 2016 Sep 7;42(9):1350-9. Epub 2016 May 7.

Department of Anesthesiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.

Over the last decade, the way to monitor hemodynamics at the bedside has evolved considerably in the intensive care unit as well as in the operating room. The most important evolution has been the declining use of the pulmonary artery catheter along with the growing use of echocardiography and of continuous, real-time, minimally or totally non-invasive hemodynamic monitoring techniques. This article, which is the result of an agreement between authors belonging to the Cardiovascular Dynamics Section of the European Society of Intensive Care Medicine, discusses the advantages and limits of using such techniques with an emphasis on their respective place in the hemodynamic management of critically ill patients with hemodynamic instability.
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http://dx.doi.org/10.1007/s00134-016-4375-7DOI Listing
September 2016
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