Direct Visualization of Distorted Twin Boundaries in Ce-Doped GdFeO3.

Utilizing advanced transmission electron microscopy (TEM), the structure at the (110)-type twin boundary (TB) of Ce-doped GdFeO3 (C-GFO) has been investigated with picometer precision. Such a TB is promising to generate local ferroelectricity within a paraelectric system, while precise knowledge about its structure is still largely missing. In this work, a direct measurement of the cation off-centering with respect to the neighboring oxygen is enabled by integrated differential phase contrast (iDPC) imaging, and up to 30 pm Gd off-centering is highly localized at the TB. Further electron energy loss spectroscopy (EELS) analysis demonstrates a slight accumulation of oxygen vacancies at the TB, a self-balanced behavior of Ce at the Gd sites, and a mixed occupation of Fe2+ and Fe3+ at the Fe sites. Our results provide an informative picture with atomic details at the TB of C-GFO, which is indispensable to further push the potential of grain boundary engineering.

Sparse 3D contrast-enhanced whole-heart imaging for coronary artery evaluation.

BACKGROUND: We investigated the feasibility of evaluating coronary arteries with a contrast-enhanced (CE) self-navigated sparse isotropic 3D whole heart T1-weighted magnetic resonance imaging (MRI) study sequence. METHODS: A total of 22 consecutive patients underwent coronary angiography and/or cardiac computed tomography (CT) including cardiac MRI. The image quality was evaluated on a 3-point Likert scale. Inter-reader variability for image quality was analyzed with Cohen's kappa for the main coronary segments (left circumflex [LCX], left anterior descending [LAD], right coronary artery [RCA]) and the left main trunk (LMT). RESULTS: Inter-reader agreement for image quality of the coronary tree ranged from substantial to perfect, with a Cohen's kappa of 0.722 (RCAmid) to 1 (LCXprox). The LMT had the best image quality. Image quality of the proximal vessel segments differed significantly from the mid- and distal segments (RCAprox vs. RCAdist, p < 0.05). The LCX segments showed no significant difference in image quality along the vessel length (LCXprox vs. LCXdist, p = n.s.). The mean acquisition time for the study sequence was 553 s (±46 s). CONCLUSION: Coronary imaging with a sparse 3D whole-heart sequence is feasible in a reasonable amount of time producing good-quality imaging. Image quality was poorer in distal coronary segments and along the entire course of the LCX.

Prognostic value of extended cardiac risk assessment before elective open abdominal aortic surgery.

BACKGROUND: Major vascular surgery is associated with a high perioperative risk and significant mortality. Despite advances in risk stratification, monitoring, and management of perioperative complications, cardiac complications are still common. Stress echocardiography is well established in coronary artery disease diagnostics; however, its prognostic value before high-risk aortic surgery is unknown. This prospective, single-center study compared the outcome of patients undergoing extended cardiac risk assessment before open abdominal aortic surgery with the outcome of patients who had received standard preoperative assessment. METHODS: The study included patients undergoing elective open abdominal aortic surgery. Patients who underwent standard preoperative assessment before the start of a dedicated protocol were compared with patients who had extended cardiac risk assessment, including dobutamine stress echocardiography, as part of a stepwise interdisciplinary cardiovascular team approach. The combined primary endpoint was cardiovascular death, myocardial infarction, emergency coronary revascularization, and life-threatening arrhythmia within 30 days. The secondary endpoint was acute renal failure and severe bleeding. RESULTS: In total, 77 patients (mean age 68.1 ± 8.1 years, 70% male) were included: 39 underwent standard and 38 underwent cardiac risk assessment. The combined primary endpoint was reached significantly more often in patients before than after implementation of the extended cardiac stratification procedure (15% vs. 0%, p = 0.025). The combined secondary endpoint did not differ between the groups. CONCLUSIONS: Patients with extended cardiac risk assessment undergoing elective open abdominal aortic surgery had better 30-day outcomes than did those who had standard preoperative assessment.

Stable patients with suspected myocardial ischemia: comparison of machine-learning computed tomography-based fractional flow reserve and stress perfusion cardiovascular magnetic resonance imaging to detect myocardial ischemia.

BACKGROUND: Machine-Learning Computed Tomography-Based Fractional Flow Reserve (CT-FFRML) is a novel tool for the assessment of hemodynamic relevance of coronary artery stenoses. We examined the diagnostic performance of CT-FFRML compared to stress perfusion cardiovascular magnetic resonance (CMR) and tested if there is an additional value of CT-FFRML over coronary computed tomography angiography (cCTA). METHODS: Our retrospective analysis included 269 vessels in 141 patients (mean age 67 ± 9 years, 78% males) who underwent clinically indicated cCTA and subsequent stress perfusion CMR within a period of 2 months. CT-FFRML values were calculated from standard cCTA. RESULTS: CT-FFRML revealed no hemodynamic significance in 79% of the patients having ≥ 50% stenosis in cCTA. Chi2 values for the statistical relationship between CT-FFRML and stress perfusion CMR was significant (p < 0.0001). CT-FFRML and cCTA (≥ 70% stenosis) provided a per patient sensitivity of 88% (95%CI 64-99%) and 59% (95%CI 33-82%); specificity of 90% (95%CI 84-95%) and 85% (95%CI 78-91%); positive predictive value of 56% (95%CI 42-69%) and 36% (95%CI 24-50%); negative predictive value of 98% (95%CI 94-100%) and 94% (95%CI 90-96%); accuracy of 90% (95%CI 84-94%) and 82% (95%CI 75-88%) when compared to stress perfusion CMR. The accuracy of cCTA (≥ 50% stenosis) was 19% (95%CI 13-27%). The AUCs were 0.89 for CT-FFRML and 0.74 for cCTA (≥ 70% stenosis) and therefore significantly different (p < 0.05). CONCLUSION: CT-FFRML compared to stress perfusion CMR as the reference standard shows high diagnostic power in the identification of patients with hemodynamically significant coronary artery stenosis. This could support the role of cCTA as gatekeeper for further downstream testing and may reduce the number of patients undergoing unnecessary invasive workup.

[Coronary physiology in the catheter laboratory]. / Koronarphysiologie im Herzkatheterlabor.

The regulation of coronary flow is mainly located in the resistance vessels of the microcirculation, so that the functional relevance of a coronary stenosis arises from the interaction between the epicardial stenosis and the downstream microcirculation. These complex interactions are precisely detectable by physiological measurements, such as the instantaneous wave-free ratio (iwFR) or the fractional flow reserve (FFR). In contrast, the purely visual assessment of the coronary anatomy could lead to misinterpretation and possibly to incorrect revascularization decisions. Consequently, in the current guidelines on myocardial revascularization of the European Society of Cardiology (ESC) the measurement of iwFR and FFR has a class IA indication in intermediate stenoses with unclear hemodynamic relevance. Despite this clear recommendation, physiological measurements are not yet regularly used in the clinical routine. Besides the purely hemodynamic assessment, novel methods such as co-registration and coronary mapping can be used for virtual planning of percutaneous coronary interventions, especially in vessels with diffuse lesions and serial stenoses. Furthermore, invasive flow measurements are also helpful for risk stratification between conservative and interventional treatment of patients with acute coronary syndrome, where additional factors of flow limitation, such as coronary spasm, thrombus and acute disturbance of the microcirculation play an important role.

Radial versus femoral artery access for percutaneous coronary artery intervention in patients with acute myocardial infarction and multivessel disease complicated by cardiogenic shock: Subanalysis from the CULPRIT-SHOCK trial.

BACKGROUND: The use and impact of transradial artery access (TRA) compared to transfemoral artery access (TFA) in patients undergoing percutaneous coronary intervention (PCI) for acute myocardial infarction (MI) complicated by cardiogenic shock (CS) remain unclear. METHODS: This is a post hoc analysis of the CULPRIT-SHOCK trial where patients presenting with MI and multivessel disease complicated by CS were randomized to a strategy of culprit-lesion-only or immediate multivessel PCI. Arterial access was left at operator's discretion. Adjudicated outcomes of interest were the composite of death or renal replacement therapy (RRT) at 30 days and 1 year. Multivariate logistic models were used to assess the association between the arterial access and outcomes. RESULTS: Among the 673 analyzed patients, TRA and TFA were successfully performed in 118 (17.5%) and 555 (82.5%) patients, respectively. Compared to TFA, TRA was associated with a lower 30-day rate of death or RRT (37.3% vs 53.2%, adjusted odds ratio [aOR]: 0.57; 95% confidence interval [CI] 0.34-0.96), a lower 30-day rate of death (34.7% vs 49.7%; aOR: 0.56; 95% CI 0.33-0.96), and a lower 30-day rate of RRT (5.9% vs 15.9%; aOR: 0.40; 95% CI 0.16-0.97). No significant differences were observed regarding the 30-day risks of type 3 or 5 Bleeding Academic Research Consortium bleeding and stroke. The observed reduction of death or RRT and death with TRA was no longer significant at 1 year (44.9% vs 57.8%; aOR: 0.85; 95% CI 0.50-1.45 and 42.4% vs 55.5%, aOR: 0.78; 95% CI 0.46-1.32, respectively). CONCLUSIONS: In patients undergoing PCI for acute MI complicated by CS, TRA may be associated with improved early outcomes, although the reason for this finding needs further research.

Characterization of circulating thrombin in patients with septic shock: a prospective observational study.

Septic shock is characterized by a dysregulated response to infection, hypotension and activation of the coagulation system. Markers of coagulation activation are commonly used to diagnose and monitor ensuing coagulopathies. In this study, we sought to determine levels of circulating thrombin in patients with septic shock. To characterize levels of circulating, active thrombin in patients with septic shock. 48 patients with septic shock were included in this prospective, observational study. Blood samples were obtained on admission, day 1, day 3 and day 6. Levels of active thrombin were measured using a standardized, clinically applicable oligonucleotide (aptamer)-based enzyme-capture assay (OECA). Thrombin levels were correlated with established indirect thrombin parameters, conventional coagulation tests, laboratory parameters, patient characteristics and outcome. Elevated levels of thrombin were detected in 27 patients (56.3%) during the course of the study. Thrombin levels were positively correlated with thrombin-antithrombin complexes (r = 0.30, p < 0.05) and negatively associated with FVII levels (r = - 0.28, p < 0.05). Thrombin levels on admission did not predict 30-day mortality (OR 0.82, 95% CI 0.23-2.92, p = 0.77). Circulating levels of active thrombin can be measured in a subset of patients with septic shock. Although thrombin levels are correlated with established markers of coagulation, they do not provide additional prognostic information.

Preliminary investigation of an idiopathic muscle disease in farmed burbot Lota lota.

The rearing of less established fish species in recirculating aquaculture systems (RASs) is increasing, but may require adaptations of the rearing facilities if health impairments occur. We observed several health issues in burbot Lota lota reared for up to 2 yr in a RAS and used microbiological, histological and molecular-biological methods to identify the causative agents. Minor skin trauma led to the development of ulcers. In addition, several fillets of burbot showed pronounced granulomatous inflammation and calcification with signs of muscle fiber degeneration which resembled a condition called 'sandy flesh disease' in North American walleye. Several infectious agents were able to be excluded as a cause for the disease. Carnobacterium maltaromaticum was isolated in high numbers in some of the affected muscle tissue. However, the role of this bacterium or other causative agents or husbandry conditions remains to be elucidated.

Demarcating and highlighting in Papuan Malay phrase prosody.

Phrase-level prosody serves two essential functions in many languages of the world: chunking information into units (demarcating) and marking important information (highlighting). Recent work suggests that prosody has a mainly demarcating function in the Trade Malay language family. That is, the use of pitch accents in these languages is limited or absent, as the main prosodic events occur on the final two syllables in a phrase. The current study investigates the extent to which Papuan Malay phrase prosody is used for demarcating and highlighting, taking into account the potential influence of word stress. This is done by means of acoustic analyses on a corpus of spontaneous speech. Both the form (F0 movement) and the possible functions (demarcating and highlighting) of the final two syllables in Papuan Malay phrases are investigated. Although most results favor the demarcating function of Papuan Malay phrase prosody, a highlighting function cannot be ruled out. The results suggest that Papuan Malay might hold an exceptional position in the typology of prosodic prominence.

Coronary CT Angiography-derived Fractional Flow Reserve: Machine Learning Algorithm versus Computational Fluid Dynamics Modeling.

Purpose To compare two technical approaches for determination of coronary computed tomography (CT) angiography-derived fractional flow reserve (FFR)-FFR derived from coronary CT angiography based on computational fluid dynamics (hereafter, FFRCFD) and FFR derived from coronary CT angiography based on machine learning algorithm (hereafter, FFRML)-against coronary CT angiography and quantitative coronary angiography (QCA). Materials and Methods A total of 85 patients (mean age, 62 years ± 11 [standard deviation]; 62% men) who had undergone coronary CT angiography followed by invasive FFR were included in this single-center retrospective study. FFR values were derived on-site from coronary CT angiography data sets by using both FFRCFD and FFRML. The performance of both techniques for detecting lesion-specific ischemia was compared against visual stenosis grading at coronary CT angiography, QCA, and invasive FFR as the reference standard. Results On a per-lesion and per-patient level, FFRML showed a sensitivity of 79% and 90% and a specificity of 94% and 95%, respectively, for detecting lesion-specific ischemia. Meanwhile, FFRCFD resulted in a sensitivity of 79% and 89% and a specificity of 93% and 93%, respectively, on a per-lesion and per-patient basis (P = .86 and P = .92). On a per-lesion level, the area under the receiver operating characteristics curve (AUC) of 0.89 for FFRML and 0.89 for FFRCFD showed significantly higher discriminatory power for detecting lesion-specific ischemia compared with that of coronary CT angiography (AUC, 0.61) and QCA (AUC, 0.69) (all P < .0001). Also, on a per-patient level, FFRML (AUC, 0.91) and FFRCFD (AUC, 0.91) performed significantly better than did coronary CT angiography (AUC, 0.65) and QCA (AUC, 0.68) (all P < .0001). Processing time for FFRML was significantly shorter compared with that of FFRCFD (40.5 minutes ± 6.3 vs 43.4 minutes ± 7.1; P = .042). Conclusion The FFRML algorithm performs equally in detecting lesion-specific ischemia when compared with the FFRCFD approach. Both methods outperform accuracy of coronary CT angiography and QCA in the detection of flow-limiting stenosis.

Clinical outcomes associated with catecholamine use in patients diagnosed with Takotsubo cardiomyopathy.

BACKGROUND: Recent hypotheses have suggested the pathophysiological role of catecholamines in the evolution of the Takotsubo syndrome (TTS). The extent of cardiac and circulatory compromise dictates the use of some form of supportive therapy. This study was designed to investigate the clinical outcomes associated with catecholamine use in TTS patients. METHODS: Our institutional database constituted a collective of 114 patients diagnosed with TTS between 2003 and 2015. The study-patients were subsequently classified into two groups based on the need for catecholamine support during hospital stay (catecholamine group n = 93; 81%, non-catecholamine group = 21; 19%). The primary end-point of our study was all-cause mortality. RESULTS: Patients receiving catecholamine support showed higher grades of circulatory and cardiac compromise (left ventricular ejection fraction (LVEF) 39.6% vs. 32.7%, p-value < 0.01) and the course of disease was often complicated by the occurrence of different TTS-associated complications. The in-hospital mortality (3.2% vs. 28.5%, p < 0.01), 30-day mortality (17.2% vs. 51.4%, p < 0.01) as well as long-term mortality (38.7% vs. 80.9%, p < 0.01) was significantly higher in the group of patients receiving catecholamine support. A multivariate Cox regression analysis attributed EF ≤ 35% (HR 3.6, 95% CI 1.6-8.1; p < 0.01) and use of positive inotropic agents (HR 2.2, 95% CI 1.0-4.8; p 0.04) as independent predictors of the adverse outcome. CONCLUSION: Rates of in-hospital events and short- as well as long-term mortality were significantly higher in TTS patients receiving catecholamine support as compared to the other study-patients. These results need further evaluation in pre-clinical and clinical trials to determine if external catecholamines contribute to an adverse clinical outcome already compromised by the initial insult.

Follow-up of iatrogenic aorto-coronary "Dunning" dissections by cardiac computed tomography imaging.

BACKGROUND: Iatrogenic aorto-coronary dissections following percutaneous coronary interventions (PCI) represent a rare but potentially life threatening complication. This restrospective and observational study aims to describe our in-house experience for timely diagnostics and therapy including cardiovascular imaging to follow-up securely high-risk patients with Dunning dissections. METHODS: Dunning dissections (DD) occurred during clinical routine PCIs, which were indicated according to current ESC guidelines. Diagnostic assessment, treatment and follow-up were based on coronary angiography with PCI or conservative treatment and cardiac computed tomography (cCTA) imaging. RESULTS: A total of eight patients with iatrogenic DD were included. Median age was 69 years (IQR 65.8-74.5). Patients revealed a coronary multi-vessel-disease in 75% with a median SYNTAX-II-score of 35.3 (IQR 30.2-41.2). The most common type of DD was type III (50%), followed by type I (38%) and type II (13%). In most patients (88%) the DD involved the right coronary arterial ostium. 63% were treated by PCI, the remaining patients were treated conservatively. 88% of patients received at least one cCTA within 2 days, 50% were additionally followed-up by cCTA within a median of 6 months (range: 4-8 months) without any residual. CONCLUSION: Independently of the type of DD (I-III) it was demonstrated that cCTA represents a valuable imaging modality for detection and follow-up of patients with DDs.

Estradiol regulates human QT-interval: acceleration of cardiac repolarization by enhanced KCNH2 membrane trafficking.

BACKGROUND: Modulation of cardiac repolarization by sexual hormones is controversial and hormonal effects on ion channels remain largely unknown. In the present translational study, we therefore assessed the relationship between QTc duration and gonadal hormones and studied underlying mechanisms. METHODS AND RESULTS: We measured hormone levels and QTc intervals in women during clomiphene stimulation for infertility and women before, during, and after pregnancy. Three heterozygous LQT-2 patients (KCNH2-p.Arg752Pro missense mutation) and two unaffected family members additionally were studied during their menstrual cycles. A comprehensive cellular and molecular analysis was done to identify the mechanisms of hormonal QT-interval regulation. High estradiol levels, but neither progesterone nor estradiol/progesterone ratio, inversely correlated with QTc. Consistent with clinical data, in vitro estradiol stimulation (60 pmol/L, 48 h) enhanced IKCNH2. This increase was mediated by estradiol receptor-α-dependent promotion of KCNH2-channel trafficking to the cell membrane. To study the underlying mechanism, we focused on heat-shock proteins. The heat-shock protein-90 (Hsp90) inhibitor geldanamycin abolished estradiol-induced increase in IKCNH2. Geldanamycin had no effect on KCNH2 transcription or translation; nor did it affect expression of estradiol receptors and chaperones. Estradiol enhanced the physical interaction of KCNH2-channel subunits with heat-shock proteins and augmented ion-channel trafficking to the membrane. CONCLUSION: Elevated estradiol levels were associated with shorter QTc intervals in healthy women and female LQT-2 patients. Estradiol acts on KCNH2 channels via enhanced estradiol-receptor-α-mediated Hsp90 interaction, augments membrane trafficking and thereby increases repolarizing current. These results provide mechanistic insights into hormonal control of human ventricular repolarization and open novel therapeutic avenues.

Dynamic four-dimensional CT angiography for the assessment of pulmonary perfusion in an adult patient with pulmonary artery occlusion and major aortopulmonary collateral after multistage repair of Fallot's Pentalogy.

Dynamic CT angiography provides haemodynamic assessment combined with detailed information on complex cardiac anatomy in patients with congenital malformations such as multistage correction of Fallot's Pentalogy.

Liver and cholestatic parameters as prognostic biomarkers of in-hospital MACE in patients with STEMI.

BACKGROUND: Liver and cholestatic parameters are increased in ST-segment elevation myocardial infarction (STEMI). The aim of the present study was to evaluate the prognostic value of these parameters to predict in-hospital major adverse cardiac events (MACE) in patients after STEMI. MATERIALS AND METHODS: Blood samples of patients with STEMI, who underwent percutaneous coronary intervention (PCI) and stent implantation, were retrospectively analysed and correlated with in-hospital events. RESULTS: The study population consisted of 847 consecutive patients (62·4 ± 13·43 years; 73·8% male). The total in-hospital MACE rate was 9·8%, driven by death of any cause (8·4%). The Mann-Whitney U-test revealed that liver and cholestatic parameters (alanine transaminase P < 0·0001, aspartate transaminase P < 0·0001, alkaline phosphatase (AP) P < 0·0001, gamma-glutamyl transferase P = 0·0006 and total bilirubin P = 0·0023) were significantly higher in the MACE group. Further logistic regression analyses confirmed the correlation between MACE and all five laboratory markers, even after adjustment for age and heart enzymes. Logistic regression model revealed AP to be the best predictor for worth outcome (OR 1·0188; 95% CI 1·0118-1·0258; P < 0·0001). CONCLUSION: Liver and cholestatic parameters are elevated in patients after STEMI. Increased AP is associated with in-hospital event rates.

A non-contrast self-navigated 3-dimensional MR technique for aortic root and vascular access route assessment in the context of transcatheter aortic valve replacement: proof of concept.

OBJECTIVES: Due to the high prevalence of renal failure in transcatheter aortic valve replacement (TAVR) candidates, a non-contrast MR technique is desirable for pre-procedural planning. We sought to evaluate the feasibility of a novel, non-contrast, free-breathing, self-navigated three-dimensional (SN3D) MR sequence for imaging the aorta from its root to the iliofemoral run-off in comparison to non-contrast two-dimensional-balanced steady-state free-precession (2D-bSSFP) imaging. METHODS: SN3D [field of view (FOV), 220-370 mm(3); slice thickness, 1.15 mm; repetition/echo time (TR/TE), 3.1/1.5 ms; and flip angle, 115°] and 2D-bSSFP acquisitions (FOV, 340 mm; slice thickness, 6 mm; TR/TE, 2.3/1.1 ms; flip angle, 77°) were performed in 10 healthy subjects (all male; mean age, 30.3 ± 4.3 yrs) using a 1.5-T MRI system. Aortic root measurements and qualitative image ratings (four-point Likert-scale) were compared. RESULTS: The mean effective aortic annulus diameter was similar for 2D-bSSFP and SN3D (26.7 ± 0.7 vs. 26.1 ± 0.9 mm, p = 0.23). The mean image quality of 2D-bSSFP (4; IQR 3-4) was rated slightly higher (p = 0.03) than SN3D (3; IQR 2-4). The mean total acquisition time for SN3D imaging was 12.8 ± 2.4 min. CONCLUSIONS: Our results suggest that a novel SN3D sequence allows rapid, free-breathing assessment of the aortic root and the aortoiliofemoral system without administration of contrast medium. KEY POINTS: • The prevalence of renal failure is high among TAVR candidates. • Non-contrast 3D MR angiography allows for TAVR procedure planning. • The self-navigated sequence provides a significantly reduced scanning time.

Left atrial appendage morphology, echocardiographic characterization, procedural data and in-hospital outcome of patients receiving left atrial appendage occlusion device implantation: a prospective observational study.

BACKGROUND: Implantation of left atrial appendage (LAA) occlusion devices was shown to be a feasible and effective alternative to oral anticoagulation in patients with non-valvular atrial fibrillation. However, only few data about in-hospital and peri-procedural data are currently available. This study aims to report about echocardiographic, procedural and in-hospital data of patients receiving LAA occlusion devices. METHODS: This single-center, prospective and observational study includes consecutively patients being eligible for percutaneous implantation of LAA occlusion devices (either Watchman™ or Amplatzer™ Cardiac Plug 2). Data on pre- and peri-procedural transesophageal echocardiography (TEE), implantation and procedure related in-hospital complications were collected. The primary efficacy outcome measure was a successful device implantation without relevant peri-device leaks (i.e., < 5 mm). RESULTS: In total, 37 patients were included, 22 receiving the Watchman™ and 15 ACP 2 device. Baseline characteristics did not differ significantly in both patient groups. The primary efficacy outcome measure was reached in 91.9% of patients (90.9% for the Watchman™, 93.3 % for the ACP 2 group). One device embolization (Watchman™ group) with successful retrieval occurred (2.7% of patients). No thromboembolism or device thrombosis were present. The majority of bleedings was caused by access site bleedings (88.3% of all bleedings), consisting mostly of mild hematomas corresponding to a BARC type 1 bleeding (80.0% of all access-site complications). One patient died due to septic shock (non-procedure related). CONCLUSIONS: In daily real-life practice, percutaneous treatment with LAA occlusion devices appears to be an effective and safe.

Size effects in MgO cube dissolution.

Stability parameters and dissolution behavior of engineered nanomaterials in aqueous systems are critical to assess their functionality and fate under environmental conditions. Using scanning electron microscopy, transmission electron microscopy, and X-ray diffraction, we investigated the stability of cubic MgO particles in water. MgO dissolution proceeding via water dissociation at the oxide surface, disintegration of Mg(2+)-O(2-) surface elements, and their subsequent solvation ultimately leads to precipitation of Mg(OH)2 nanosheets. At a pH ≥ 10, MgO nanocubes with a size distribution below 10 nm quantitatively dissolve within few minutes and convert into Mg(OH)2 nanosheets. This effect is different from MgO cubes originating from magnesium combustion in air. With a size distribution in the range 10 nm ≤ d ≤ 1000 nm they dissolve with a significantly smaller dissolution rate in water. On these particles water induced etching generates (110) faces which, above a certain face area, dissolve at a rate equal to that of (100) planes.1 The delayed solubility of microcrystalline MgO is attributed to surface hydroxide induced self-inhibition effects occurring at the (100) and (110) microplanes. The present work underlines the importance of morphology evolution and surface faceting of engineered nanomaterials particles during their dissolution.

Coronary CT angiography-derived fractional flow reserve correlated with invasive fractional flow reserve measurements--initial experience with a novel physician-driven algorithm.

OBJECTIVES: The present study aimed to determine the feasibility of a novel fractional flow reserve (FFR) algorithm based on coronary CT angiography (cCTA) that permits point-of-care assessment, without data transfer to core laboratories, for the evaluation of potentially ischemia-causing stenoses. METHODS: To obtain CT-based FFR, anatomical coronary information and ventricular mass extracted from cCTA datasets were integrated with haemodynamic parameters. CT-based FFR was assessed for 36 coronary artery stenoses in 28 patients in a blinded fashion and compared to catheter-based FFR. Haemodynamically relevant stenoses were defined by an invasive FFR ≤0.80. Time was measured for the processing of each cCTA dataset and CT-based FFR computation. Assessment of cCTA image quality was performed using a 5-point scale. RESULTS: Mean total time for CT-based FFR determination was 51.9 ± 9.0 min. Per-vessel analysis for the identification of lesion-specific myocardial ischemia demonstrated good correlation (Pearson's product-moment r = 0.74, p < 0.0001) between the prototype CT-based FFR algorithm and invasive FFR. Subjective image quality analysis resulted in a median score of 4 (interquartile ranges, 3-4). CONCLUSIONS: Our initial data suggest that the CT-based FFR method for the detection of haemodynamically significant stenoses evaluated in the selected population correlates well with invasive FFR and renders time-efficient point-of-care assessment possible. KEY POINTS: • CT-based FFR computation is a promising novel non-invasive application. • A novel prototype algorithm permits time-efficient point-of-care CT-based FFR assessment. • Initial results of the CT-based FFR prototype algorithm compare favourably with FFR.

Boosting or inhibiting - how semantic-pragmatic and syntactic cues affect prosodic prominence relations in German.

In this exploratory study, we investigate the influence of several semantic-pragmatic and syntactic factors on prosodic prominence production in German, namely referential and lexical newness/givenness, grammatical role, and position of a referential target word within a sentence. Especially in terms of the probabilistic distribution of accent status (nuclear, prenuclear, deaccentuation) we find evidence for an additive influence of the discourse-related and syntactic cues, with lexical newness and initial sentence position showing the strongest boosting effects on a target word's prosodic prominence. The relative strength of the initial position is found in nearly all prosodic factors investigated, both discrete (such as the choice of accent type) and gradient (e.g., scaling of the Tonal Center of Gravity and intensity). Nevertheless, the differentiation of prominence relations is information-structurally less important in the beginning of an utterance than near the end: The prominence of the final object relative to the surrounding elements, especially the verbal component, is decisive for the interpretation of the sentence. Thus, it seems that a speaker adjusts locally important prominence relations (object vs. verb in sentence-final position) in addition to a more global, rhythmically determined distribution of prosodic prominences across an utterance.