bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimizing the structural topology of bifunctional invisible cloak manipulating heat flux and direct current
Authors: Fujii Garuda , Akimoto Youhei
Published: October 2019

We generate optimal topologies in the structural design of bifunctional cloaks manipulating heat flux and direct current, using topology optimization that incorporates both thermal conductivity and electrical direct current. The bifunctional cloak composed of bulk isotropic materials is designed to restrain thermal and electrical disturbances caused by an insulated obstacle by minimizing the difference between cloaked distributions and referenced distributions when no obstacle is present. Our results show that the presented optimizations provide bifunctional cloaks that reproduce undisturbed temperature and voltage distributions. We also demonstrate topology optimizations for bifunctional cloaks operating for multiangle flows and those for cloaks that are robust against variations in conductive properties.
Size and temperature dependence of photoluminescence of hybrid perovskite nanocrystals
Authors: Naghadeh Sara Bonabi , Sarang Som , Brewer Amanda , Allen A’Lester , Chiu Yi-Hsuan , Hsu Yung-Jung , Wu Jhen-Yang , Ghosh Sayantani , Zhang Jin Z.
Published: October 2019

In this work, we studied the effects of particles’ size and temperature on the photoluminescence (PL) of CH3NH3PbBr3 perovskite nanocrystals (PNCs), with the PNC size controlled by varying the surface passivating ligands. The structural and optical properties of the PNCs were investigated using UV-Vis and PL spectroscopy, revealing strong quantum confinement effects. Temperature dependent PL measurements showed the spectral blue shift of the PL peak for the small PNCs (3.1 ± 0.2 nm) with decreasing temperature from 300 K to 20 K, which is opposite to the red shift with decreasing temperature observed for large- (9.2 ± 0.5 nm) and middle-sized (5.1 ± 0.3 nm) PNCs. The PL lifetime also increased with increasing temperature for the larger PNCs, while it remained about the same for the small and middle-sized PNCs. This increase in lifetime with temperature is attributed to exciton dissociation to free carriers at higher temperatures and to the formation of polar domains in the PNCs. However, the small and middle-sized PNCs did not show such a trend, which may be due to efficient defect passivation as higher concentration of 3-aminopropyl trimethoxysilane (APTMS) was used and to the role of particle size in surface state delocalization. Cryo-X-ray diffraction showed no new peak formation or peak splitting as temperature was varied, which suggests efficient crystal phase stabilization in PNCs of all three sizes controlled by the concentration of APTMS. These results emphasize the importance of size and surface properties of PNCs in their optical properties such as PL quantum yield, PL lifetime, and crystal phase stability.
Transition from rectification to resistive-switching in Ti/MgF2/Pt memory
Authors: Sun Yi , Wang Chao , Xu Hui , Song Bing , Li Nan , Li Qingjiang , Liu Sen
Published: October 2019

Magnesium fluoride is a promising candidate for resistive-switching random access memory (RRAM) with biodegradable property. However, the underlying resistive-switching (RS) mechanism and conduction mechanism in MgF2 material is still not fully studied, which limits the further performance optimization. In this work, we have demonstrated the rectification and bipolar RS behaviors in Ti/MgF2/Pt device. The un-Formed device exhibits stable rectifying characteristics, with a rectifying ratio of ∼103 at ±3 V. Furthermore, transition from rectification mode to RS behavior can be achieved by a Forming process. Then the analogue switching properties with high uniformity was obtained with quasi-DC sweeps, and gradual modulation of multi-state was further realized. At last, the conduction and switching mechanism was discussed.
Influence of rf sputter power on ZnO film characteristics for transparent memristor devices
Authors: Simanjuntak Firman Mangasa , Ohno Takeo , Samukawa Seiji
Published: October 2019

The impact of the radio-frequency (rf) sputtering power on the switching characteristics of ZnO-based transparent memristor devices has been investigated. Memristor devices made with a high rf power exhibited excellent switching characteristics; meanwhile, decreasing the rf power led to less-apparent switching behavior and increased likelihood of device breakdown. However, high rf power memristors exhibited a reduced switching uniformity as the rf power significantly affected the defect concentration as well as the microstructure of the deposited ZnO films, which determine the switching characteristics and performance of memristor devices.
Cavitation performance of multistage slurry pump in deep-sea mining
Authors: Xu Hai-Liang , Chen Wei , Xu Cong
Published: October 2019

Liquid–gas and liquid–solid phase relationships are established in this study using the theories of cavitation nucleation and solid–liquid two-phase flow, respectively. The relationship between gas and solid phases is then derived, and the effect of solid phase parameter characteristics on the cavitation characteristics of the slurry-conveying slurry in the pump is analyzed. The influence law of particle concentration and speed on the airing performance of two-stage slurry pumps is studied on the basis of computational fluid mechanics. Results show that the cavitation phenomenon reduces the overall pressure of the flow field of deep-sea mining slurry pump. The lowest pressure area is the area of airing development at the entrance of the first-stage impeller blade. The cavitation of the mineral pulp pump becomes evident, and air bubbles rapidly spread over the outlet as the solid phrase particle grows in size. Moreover, solid phase concentration heightens the cavitation of the slurry pump. The cavitation in the pump gradually intensifies as the speed of the slurry pump increases, and a large area of air bubbles sharply forms and disturbs the flow field of the pump when the speed reaches 2000 r/min. In addition, the vortex increases, and the jet phenomenon becomes serious. A comprehensive analysis of the cavitation characteristics of the slurry pump is obtained at the following speed, solid phase volume concentration, and solid phase particle size: n = 1450 r/min, C = 5.3% and d = 20 mm, respectively.
Associative diazotrophic bacteria from forage grasses in the Brazilian semi-arid region are effective plant growth promoters
Authors: Antunes Gabiane dos Reis , Santana Sheilla Rios Assis , Escobar Indra Elena Costa , Brasil Marivaine da Silva , Araújo Gherman Garcia Leal de , Voltolini Tadeu Vinhas , Fernandes-Júnior Paulo Ivan
Published: October 2019

The study of plant growth-promoting bacteria (PGPB) can identify outstanding bacteria for crops. For forage grasses adapted to drylands, the selection of PGPB can increase the field performance of pastures. The aim of this study was to isolate, and characterise at molecular, biochemical and symbiotic levels, diazotrophic bacteria obtained from buffel grass (Cenchrus ciliaris), sorghum (Sorghum bicolor) and Tifton 85 (Cynodon spp.) from Brazilian semi-arid region fields. Field-grown plants were collected, and the roots were surface-disinfected, crushed and inoculated in a semi-solid medium. After the formation and confirmation of microaerophilic pellicles, the bacteria were isolated and purified. All bacterial isolates were subjected to nifH gene amplification and identified by their partial 16S rRNA gene sequences. The bacteria were evaluated for the production of auxins and siderophores, calcium phosphate solubilisation, and diazotrophic ability as ‘in vitro’ plant growth-promotion traits. A plant inoculation assay was conducted to assess the plant growth-promotion abilities of the bacterial isolates. Twenty-one bacterial isolates harboured the nifH gene (nifH+), among which nine were obtained from sorghum, eight from buffel grass, and four from Tifton 85. The bacterial isolates were classified as Bacillus (8), Stenotrophomonas (7), Agrobacterium (4), Cellulomonas (1) and Paenibacillus (1). All were shown to be auxin producers, with 14 isolates showing diazotrophic capacity ‘in vitro’. Fourteen isolates increased plant N content, but the bacterial strains ESA 392 and ESA 398 (Bacillus), ESA 397 and ESA 407 (Stenotrophomonas), and ESA 401 (Agrobacterium) were shown to promote both plant growth and N nutrition. These strains are candidates for further assays to evaluate their agronomic performance under field conditions, aiming inoculant production for forage grasses in drylands.
Soluble tubulin is significantly enriched at mitotic centrosomes
Authors: Baumgart Johannes , Kirchner Marcel , Redemann Stefanie , Bond Alec , Woodruff Jeffrey , Verbavatz Jean-Marc , Jülicher Frank , Müller-Reichert Thomas , Hyman Anthony A. , Brugués Jan
Published: October 2019

During mitosis, the centrosome expands its capacity to nucleate microtubules. Understanding the mechanisms of centrosomal microtubule nucleation is, however, constrained by a lack of knowledge of the amount of soluble and polymeric tubulin at mitotic centrosomes. Here we combined light microscopy and serial-section electron tomography to measure the amount of dimeric and polymeric tubulin at mitotic centrosomes in early C. elegans embryos. We show that a C. elegans one-cell stage centrosome at metaphase contains >10,000 microtubules with a total polymer concentration of 230 µM. Centrosomes concentrate soluble α/β tubulin by about 10-fold over the cytoplasm, reaching peak values of 470 µM, giving a combined total monomer and polymer tubulin concentration at centrosomes of up to 660 µM. These findings support in vitro data suggesting that microtubule nucleation in C. elegans centrosomes is driven in part by concentrating soluble tubulin.
Focus on multilayer networks
Authors: Moreno Yamir , Perc Matjaž
Published: October 2019

Multilayer networks have in recent years emerged as an important new paradigm of network science. Groundbreaking research has shown that processes that unfold on different but interdependent network layers can not be simply reduced to a conglomerate of additive processes on a single network. On the contrary, small and seemingly unimportant changes in one network layer can have far-reaching and indeed catastrophic consequences in other network layers. Such cascades of failures can lead to concurrent malfunctions in electrical power grids, they can gridlock traffic, and accelerate epidemics, to name just some examples. In the light of this functional relevance, network science has had to redefine structural measures, rethink growth processes, and come up with new mathematical formulations for multilayer networks. The field is still very much alight and vibrant, and with the focus on multilayer networks, the New Journal of Physics has given due space to the forefront research along these lines.
Effects of refractory period on dynamical range in excitable networks*
Authors: Dong Ya-Qin , Wang Fan , Wang Sheng-Jun , Huang Zi-Gang
Published: October 2019

Effects of refractory period on the dynamical range in excitable networks are studied by computer simulations and theoretical analysis. The first effect is that the maximum or peak of the dynamical range appears when the largest eigenvalue of adjacent matrix is larger than one. We present a modification of the theory of the critical point by considering the correlation between excited nodes and their neighbors, which is brought by the refractory period. Our analysis provides the interpretation for the shift of the peak of the dynamical range. The effect is negligible when the average degree of the network is large. The second effect is that the dynamical range increases as the length of refractory period increases, and it is independent of the average degree. We present the mechanism of the second effect. As the refractory period increases, the saturated response decreases. This makes the bottom boundary of the dynamical range smaller and the dynamical range extend.
New Compact 341 Model: Higgs Decay Modes
Authors: Mebarki N. , Djouala M. , Mimouni J. , Aissaoui H.
Published: October 2019

New developments in the anomaly free compact 341 model are discussed and the higgs bosons decay modes are studied taking into account the contributions of new fermions, gauge bosons and scalar bosons predicted by the model. It is shown from signal strengths and the branching ratios of the various decay modes analysis and the LHC constraints that there is a room for this extended BSM model and it is viable.
Model of wormholes under Krori-Barua spacetime in the presence of matter
Authors: Islam Safiqul , Rahaman Farook , Islam Nasarul
Published: October 2019

We intend to investigate particular models of wormholes with ordinary matter source. The exact wormhole solutions are deduced by numerically solving the Einstein’s field equations with the stress-energy-tensor components. A particular form of feasible wormhole shape function is utilized. We study the solutions considering the Krori-Barua (KB) ansatz [K.D. Krori and J. Barua, J. Phys. A: Math. Gen. 8, 508 (1975)] in presence of perfect fluid matter. The obtained solutions are free from central singularity. The wormhole model thus obtained under Krori-Barua spacetime satisfies the flare-out conditions. Some physical features are briefly discussed.
Constraining the charge of the Galactic centre black hole
Authors: Zajaček Michal , Tursunov Arman , Eckart Andreas , Britzen Silke , Hackmann Eva , Karas Vladimír , Stuchlík Zdeněk , Czerny Bozena , Zensus J. Anton
Published: October 2019

In this contribution, we summarize our results concerning the observational constraints on the electric charge associated with the Galactic centre black hole – Sgr A*. According to the no-hair theorem, every astrophysical black hole, including supermassive black holes, is characterized by at most three classical, externally observable parameters – mass, spin, and the electric charge. While the mass and the spin have routinely been measured by several methods, the electric charge has usually been neglected, based on the arguments of efficient discharge in astrophysical plasmas. From a theoretical point of view, the black hole can attain charge due to the mass imbalance between protons and electrons in fully ionized plasmas, which yields about ~ 108 C for Sgr A*. The second, induction mechanism concerns rotating Kerr black holes embedded in an external magnetic field, which leads to electric field generation due to the twisting of magnetic field lines. This electric field can be associated with the induced Wald charge, for which we calculate the upper limit of ~ 1015 C for Sgr A*. Although the maximum theoretical limit of ~ 1015 C is still 12 orders of magnitude smaller than the extremal charge of Sgr A*, we analyse a few astrophysical consequences of having a black hole with a small charge in the Galactic centre. Two most prominent ones are the effect on the X-ray bremsstrahlung profile and the effect on the position of the innermost stable circular orbit.
Multiple anthropogenic drivers behind upward trends in organic carbon concentrations in boreal rivers
Authors: Asmala Eero , Carstensen Jacob , Räike Antti
Published: October 2019

Increases of riverine organic carbon concentrations have been observed across the northern hemisphere over the past few decades. These increases are the result of multiple environmental drivers, but the relative importance of the drivers is still unclear. We analyzed a dataset of >10 000 observations of riverine total organic carbon (TOC) concentrations and associated water chemistry and hydrological observations from 1993 to 2017. The observations span a ∼600 km north–south gradient from 30 individual river systems in Finland. Our data show significantly increasing TOC concentrations in 25 out of 30 systems, with an average increase from 12.0 to 15.1 mg l−1. The observed increase in riverine TOC concentrations led to an increase of 0.28 Mt in annual TOC load to the Baltic Sea from 1993 level to 2017 level. We analyzed the role of three putative environmental drivers of the observed TOC trends. Multiple regression analysis revealed that the most common driver was discharge, which alone explained TOC increases in 13 rivers, whereas pH and temperature were less important drivers (sole predictor in one and zero rivers, respectively). Different permutations of these three drivers were also found to be significant; the combination of discharge and pH being the most common (4 rivers). Land use was not in general linked with trends in TOC, except for the proportion of ditched land in the catchment, which was significantly correlated with increases in TOC concentration. Land use showed significant relationships with trends in discharge and pH. We also found that catchment characteristics are regulating the extent of these regional or global environmental changes causing the upward trends of riverine organic carbon.
Twisting and tweezing the spin wave: on vortices, skyrmions, helical waves, and the magnonic spiral phase plate
Authors: Jia Chenglong , Ma Decheng , Schäffer Alexander F , Berakdar Jamal
Published: October 2019

Spin waves are the low-energy excitations of magnetically ordered materials. They are key elements in the stability analysis of the ordered phase and have a wealth of technological applications. Recently, we showed that spin waves of a magnetic nanowire may carry a definite amount of orbital angular momentum components along the propagation direction. This helical, in addition to the chiral, character of the spin waves is related to the spatial modulations of the spin-wave phase across the wire. It, however, remains a challenge to generate and control such modes with conventional magnetic fields. Here, we make the first proposal for magnetic spiral phase plate by appropriately synthesizing two magnetic materials that have different speeds of spin waves. It is demonstrated with full-numerical micromagnetic simulations that despite the complicated structure of demagnetization fields, a homogeneous spin wave passing through the spiral phase plate attains the required twist and propagates further with the desired orbital angular momentum. While excitations from the ordered phase may have a twist, the magnetization itself can be twisted due to internal fields and forms what is known as a magnetic vortex. We point out the differences between both types of magnetic phenomena and discuss their possible interaction.
Effectiveness and safety of ferric carboxymaltose therapy in peritoneal dialysis patients: an observational study
Authors: Portolés-Pérez Jose , Durá-Gúrpide Beatriz , Merino-Rivas José Luis , Martín-Rodriguez Leyre , Hevia-Ojanguren Covadonga , Burguera-Vion Victor , Yuste-Lozano Claudia , Sánchez-García Luisa , Rodriguez-Palomares Jose Ramon , Paraiso Vicente ,   the GCDP Study Group
Published: October 2019

Background

The efficacy of intravenous (IV) ferric carboxymaltose (FCM) has been demonstrated in haemodialysis and non-dialysis studies, but evidence is lacking in patients undergoing peritoneal dialysis (PD).

Methods

This multicentre, retrospective study evaluated the effectiveness and safety of FCM in patients on PD over 12 months. We retrospectively reviewed the electronic medical records of PD patients who initiated FCM treatment between 2014 and 2017 across seven Spanish centres.

Results

Ninety-one patients were included in the safety population (mean ± SD age 57.7 ± 15.0 years) and 70 in the efficacy population (mean age 50.9 ± 14.5 years). No hypersensitivity reaction, FCM discontinuation or dose adjustment due to a serious adverse event (SAE) was registered in the safety population. The most common non-SAEs reported were headache (four events), mild hypotension (three events) and hypertension (two events), among others. In the efficacy population (n = 70), 68.6% of patients achieved ferritin levels of 200–800 ng/mL, 78.4% achieved transferrin saturation (TSAT) >20%, and 62.8% achieved TSAT >20% and ferritin >200 ng/mL after 12 months of FCM initiation (P < 0.01). Haemoglobin (Hb) levels were maintained at >11 g/dL with a lower dose of darbepoetin throughout the follow-up. The sub-analysis of patients naïve to IV iron and with absolute or relative iron deficiency (n = 51) showed that 76.5% reached ferritin >200 ng/mL, 80.4% TSAT >20% and Hb increased (1.2 g/dL) after 4 months of FCM treatment (P < 0.01).

Conclusion

In this multicentre, retrospective, real-world study conducted in the PD population, FCM was effective, safe and easy to administer during routine clinical visits.
An unusual case of fulminant leptospiral myocarditis: a case report
Authors: Khoo Chun Yuan , Ng Choon Ta , Zheng Shuwei , Teo Loon Yee
Published: October 2019

Background

Fulminant myocarditis secondary to leptospirosis is rare and associated with poor outcomes.

Case summary

We describe a 60-year-old gentleman with fulminant leptospiral myocarditis and profound cardiogenic shock requiring veno-arterial extracorporeal membrane oxygenator (VA-ECMO) support. He was given high-dose pulse steroids early on post-VA-ECMO implantation and achieved full recovery. To our knowledge, this is the first reported case of leptospiral myocarditis with multiorgan dysfunction successfully managed by VA-ECMO and high-dose pulse steroids.

Discussion

This case report highlights the potential benefits of steroids in the management of leptospiral myocarditis which requires further validation. Early aggressive supportive management with ECMO should be considered in patients with fulminant leptospiral myocarditis.
2980The effect of monoclonal antibodies against PCSK9 on circulating CD34+ progenitor cells interactions with platelets in patients with familial hypercholesterolemia
Authors: Tsouka A N , Liberopoulos E N , Rizos C V , Christopoulou E C , Elisaf M S , Tselepis A D
Published: October 2019

Introduction

Platelets interact with circulating CD34+ progenitor cells inducing their differentiation into endothelial progenitor cells (EPCs) and further promoting EPC maturation into endothelial cells, an important step for endothelial regeneration and angiogenesis. PSCK9 is a serine protease that may not only play a crucial role in binding to the low density lipoprotein receptor (LDL-R) increasing its endosomal and lysosomal degradation thus inhibiting its recycling to the cell surface, leading to increasing LDL-cholesterol levels in plasma, but may also exhibit several, independent on LDL-R, activities on a plethora of cell types, including platelets.

Purpose

We investigated whether monoclonal antibodies (mabs) against PCSK9 could affect platelet interaction with CD34+ cells as well as their differentiation into EPCs, in patients with Familial Hypercholestorelemia (FH).

Patients and methods

Patients with FH (n=11, 8 men and 3 women, mean age 53±10 years) being under statin/ezetimibe therapy (40mg statin/ 10mg ezetimibe) participated in the study. Patients exhibited resisting high LDL-cholesterol levels, therefore following the existing guidelines, they received mab against PCSK9 (7 evolocumab, 140mg/ml and 4 alirocumab, 150mg/ml) every two weeks. Blood samples were drawn before and after 4 doses of the antibody i.e. after two months (Follow-up). In addition to the patients' serum lipid profile, the endothelial phenotype of CD34+ (membrane expression levels of KDR which is a receptor for VEGF and an endothelial phenotype marker) on CD34+ cells (CD34+-KDR+ cells) and the formation of platelet-CD34+ (CD61+-CD34+) and platelet-KDR+ (CD61+-KDR+) conjugates were also determined by flow cytometry on whole blood after dual labelling with anti-VEGFR-R2/KDR-PE, anti-CD61-PerCP and anti-CD34-FITC. The results were expressed as the %gated of CD34+-KDR+ cells, as well as CD61+-CD34+ and CD61+-KDR+ conjugates.

Results

The baseline LDL-cholesterol levels were significantly reduced from 172±43 mg/dl to 51±17 at follow-up, p=0.0001. Importantly, the formation of CD61+-CD34+ and CD61+-KDR+ conjugates were increased from baseline to follow-up (from 1.39±1.3 to 2.23±2.8, p=0.037) and (from 2.91±4.2 to 5.92±6.01, p=0.014), respectively. The membrane expression of KDR on CD34+ cells was also increased from 0.79±0.9 to 1.36±0.90, p=0.042, which reflects the increase in the CD34+ endothelial phenotype.

Conclusion

We show for the first time that the mabs against PCSK9, significantly increase the CD34+ endothelial phenotype in FH patients, which may at least partially attributed to the increase in the platelet interaction with CD34+ cells (platelet-CD34+ conjugates). The underlying mechanisms as well as the consequences of this effect at the clinical level for these patients are under investigation.
3039Vulnerability of carotid atherosclerosis: relationship with plaque location, plaque eccentricity and vessel remodeling patterns. Insight from the the MAGNETIC observational study
Authors: Catalano O , Cerabolini C , Eshja E , Bendotti G , De Salvo M , Aloi T L , Ferrari Bardile A , Frascaroli M , Zanaboli D , Tibollo V , Bellazzi R , Poggi P , Pedretti R F E
Published: October 2019

Carotid atherosclerosis is a cause of brain ischemic events. Cardiovascular magnetic resonance (CMR) can assess plaque vulnerability. We investigated atherosclerosis vulnerability in relation to plaque location, eccentricity and vessel remodeling. Methods-Baseline CMR evaluations of the MAGNETIC observational study, were analyzed. We quantitated with MRI-Plaque View™, vessel lumen/wall and vulnerable plaque components of a 32-mm segment of common carotid artery (12 mm), bulb (8 mm) and internal carotid artery (12 mm). Lipid-rich necrotic core [LRNC], fibrous cap [CAP] and intraplaque hemorrhage [IPH] were expressed as percent of wall area. Results-A data-set of 8080 sections of adequate quality in 260 patients (198 male [76%], median age 71 years [65–76]), were analyzed. Patients were on therapy with antiplatelet, ACE-inhibitors/ARB and statins (196–229 out of 260 [75–88%]). We found significant differences in plaque composition according to longitudinal and circumferential location, eccentricity and vessel remodeling (table). At multivariate regression analysis, including classical RF and atherosclerotic burden, we found an independent association of: LRNC and IPH with longitudinal location, eccentricity and positive remodeling, and of CAP with eccentricity (p<0.001 for all).

Lipid-rich necrotic core Fibrous cap Intraplaque hemorrhage Longitudinal distribution Common carotid artery 4% [1–10] p<0.001 6% [4–11] p<0.001 0% [0–3] p<0.001 Carotid bulb 7% [3–13] 9% [5–13] 1% [0–4] Internal carotid artery 3% [0–10] 7% [4–11] 0% [0–1] Circunferenzial location Antero-medial 4% [0–11] p<0.001 7% [4–12] p=0.07 0% [0–2] p<0.001 Antero-lateral 6% [1–12] 8% [5–12] 1% [0–4] Postero-lateral 5% [0–11] 7% [4–12] 0% [0–3] Postero-medial 5% [0–11] 7% [4–12] 0% [0–1] Plaque eccentricity Concentric 3% [0–9] p<0.001 7% [4–11] p<0.001 0% [0–2] p<0.001 Eccentric 9% [4–15] 9% [5–13] 1% [0–4] Remodelling pattern Negative 4% [0–10] p<0.001 7% [4–11] p<0.001 0% [0–2] p<0.001 Positive 7% [3–13] 8% [5–13] 1% [0–4] Plaque eccentricity was defined as eccentricity index (EI = [maximum wall thickness − minimum wall thickness]/maximum wall thickness) in the highest quartile. Positive remodeling was defined as remodeling index (= [vessel cross-sectional area − reference area]/cross-sectional area) in the highest quartile.

Conclusions

Carotid atherosclerotic plaque vulnerability seems to be independently associated with longitudinal location, plaque eccentricity and vessel positive remodeling.

Acknowledgement/Funding

Bayer AG, Leverkusen, Germany
3042Gender differences in the prevalence of a normal IMT with increasing severity of carotid disease
Authors: Matangi M , Cases M , Brouillard D , Armstrong D , Johri A
Published: October 2019

Background

The ARIC group has shown that increasing IMT is only predictive of increased cardiovascular (CV) risk in males (M). Plaque is predictive of increased CV risk in both M and females (F).

Purpose

To determine the prevalence of a normal IMT (<1.00mm) in M and F with evidence of carotid plaque. Plaque score (PS) was used as a measure of severity of disease.

Methods

Our database was searched for patients with all the required data, IMT, PS and plaque area. IMT was measured with automatic edge detection software, PS was calculated using the Rotterdam method and plaque area was measured in the carotid bulb and ICA bilaterally. Only the first carotid study was used in the analysis. PS of 0–6 were used to estimate plaque severity. ANOVA and the Fisher's exact test were used to detect differences between groups. A p value of <0.05 was considered significant.

Results

There were 5981 patients, 3062 M and 2919 F with an average age of 62.1±11.3 years. Table I. indicates that with increasing PS, age, IMT and plaque area all increase, with a reciprocal decrease in the proportion of patients with a normal IMT. Of 3829 patients with carotid plaque 1355 (35.4%) had an IMT <1.00mm. There were clear gender differences with a much higher prevalence of a normal IMT in F with carotid plaque than M, 776 of 1772 (43.8%) versus 579 of 2057 (28.1%), p<0.0001, Fisher's exact test. This gender difference applies to most groups with increasing plaque burden except those with the most severe disease (PS “5–6”).

Table 1 PS “0” PS “1” PS “2” PS “3” PS “4” PS “5–6” N 2152 896 1209 792 562 370 ANOVA Age 57.6±12.2 60.4±9.2 63.0±9.5 66.5±9.3 67.8±8.9 71.5±8.8 <0.0001 IMT 0.94±0.32 1.00±0.23 1.08±0.29 1.30±0.55 1.51±0.75 2.77±0.88 <0.0001 Plaque area 0 16.5±11.6 35.1±20.0 58.6±29.9 91.0±43.1 130.4±61.3 <0.0001 Males 1005 424 627 422 331 253 IMT <1.00mm 671 222 226 77 50 4 Percentage 66.8% 52.4% 36.0% 18.2% 15.1% 1.6% Females 1147 472 582 370 231 117 IMT <1.00mm 879 293 288 136 57 2 Percentage 76.6% 62.1% 49.5% 36.8% 24.6% 1.7% Fisher's test <0.0001 <0.005 <0.0001 <0.0001 <0.0001 NS PS = Carotid ÷ 6 segments, assigned “0” or “1” if plaque is absent or present.

Conclusions

Significantly more women with carotid plaque have a normal IMT. This may explain why IMT fails to be predictive of CV risk in women.
3078Usefulness of a semi-quantitative and layer-specific assessment of the relative apical sparing pattern of longitudinal strain for the identification of cardiac amyloidosis
Authors: Saito M , Imai M , Wake D , Higaki R , Sumimoto T , Inaba S
Published: October 2019

Background

The relative apical sparing pattern (RASP) of left ventricular longitudinal strain (LS) is determined using a strain polar map, while global longitudinal strain is measured using speckle-tracking echocardiography, and it is frequently associated with cardiac amyloidosis (CA). However, the definition of visual RASP is ambiguous, and this leads to insufficient reproducibility, whereas quantitative RASP takes time and leads to difficulty in the clinical application. Generally, amyloid predominantly accumulates in the endo-myocardial layer. As such, layer-specific analysis of RASP may more accurately identify CA. Therefore, the aims of this study were to explore the reproducible and easy definition of RASP for identifying CA and investigate the effect of layer-specific analysis on the assessment.

Methods

A total of 40 patients with CA diagnosed by biopsy and technetium pyrophosphate scintigraphy were compared with 120 control patients matched for mean left ventricular wall thickness (40 aortic stenosis, 40 hypertrophic cardiomyopathy, and 40 hypertensive heart disease). We compared the discriminative abilities of three definitions of RASP (visual, quantitative, and semi-quantitative). According to a previous paper, visual RASP was defined as visual reduction of LS in the basal and middle LS segments (light red or blue) relative to the apical LS (red). Quantitative RASP was calculated using the following formula: average apical LS/(average basal LS + average mid-ventricle LS), then binarized by the optimal cut-off value for predicting CA. Semi-quantitative RASP was defined as reduction of LS (≥-10%) in five or more segments out of the basal six segments, relative to apical LS (≤-15%). Sample cases are shown in Figure (left). Visual and semi-quantitative RASP were independently assessed by two blinded sonographers. The RASP at the endo-myocardial and all layers was evaluated using customized software. The concordance was assessed using the kappa statistic, whereas the discriminative ability was assessed using receiver operating characteristic curve analysis.

Results

The concordance of visual RASP was modest but its semi-quantitative RASP was perfect (Table right). The discriminative ability of semi-quantitative RASP at each layer was significantly better than that of visual RASP and close to that of the binary quantitative RASP. Additionally, the discriminative abilities of visual (p=0.10) and semi-quantitative (p=0.11) RASP at the endo-myocardial layer appeared to be better than those at all layers.

Conclusions

The assessment method of semi-quantitative RASP is easy and highly reproducible. Furthermore, it accurately discriminates CA. In addition, assessment at the endo-myocardial layer potentially improves the discriminative ability.
3080Postsystolic shortening yields novel and independent prognostic information on cardiovascular events and mortality in patients with type 2 diabetes
Authors: Brainin P , Jensen M T , Biering-Soerensen T , Moegelvang R , Fritz-Hansen T , Vilsboell T , Rossing P , Joergensen P G
Published: October 2019

Background

Cardiovascular disease is the leading cause of death and disability in patients with type 2 diabetes. We aimed to evaluate if postsystolic shortening, a marker of impaired myocardial function, may provide prognostic information on cardiovascular events and mortality in patients with type 2 diabetes.

Method

We prospectively studied 783 patients with diabetes type 2 (63% male, age 65 [58, 70] years; HbA1c 54 [48, 65] mmol/mol; diabetes duration 11 [6, 17] years) who underwent speckle tracking echocardiography. Patients with left bundle branch block, atrial fibrillation and a history of heart failure and myocardial infarction were excluded. The primary endpoint was the composite of incident heart failure, myocardial infarction and cardiovascular death. The secondary endpoint was all-cause death. We defined the postsystolic index (PSI) as: [100x (maximum strain in cardiac cycle – peak systolic strain)/ (maximum strain in cardiac cycle)].

Results

During the median follow-up of 4.9 years [4.2, 5.3], 87 patients (11%) reached the primary endpoint and 80 (10%) died from any cause. Each 1% increase in the PSI was associated with the primary (HR 1.07 95% CI 1.02–1.13, P<0.001, Fig A) and secondary endpoint (HR 1.09 95% CI 1.04–1.14, P<0.001, Fig B). After adjusting for age, sex, hypertension, smoking, duration of diabetes, cholesterol, eGFR, left ventricular ejection fraction and mass index, E/A-ratio, deceleration time and left atrial volume index, the PSI remained an independent predictor of both endpoints; primary (HR 1.07 per 1% increase 95% CI 1.01–1.14, P=0.028) and secondary endpoint (HR 1.07 per 1% increase, 95% CI 1.01–1.14, P=0.022).

PSI and the endpoints

Conclusion

In patients with type 2 diabetes, assessment of PSI yields novel and independent prognostic information on cardiovascular events and mortality. Hence, PSI may offer guidance on risk stratification in patients with type 2 diabetes.
3154The incidence of atrial fibrillation continues to increase across all socioeconomic subgroups: 30-year time trends from a Nationwide cohort
Authors: Yaqub Z M , Sehested T S G , Bonde A N , Olesen J B , Torp-Pedersen C , Gislason G , Staerk L
Published: October 2019

Introduction

The incidence rate of atrial fibrillation (AF) has increased substantially throughout the last decades. Socioeconomic factors such as income and education are well known to be associated with the development of cardiovascular disease, however, the impact on long-term trends of AF incidence rates is yet to be described.

Purpose

This nationwide cohort study examined the temporal trends of AF incidence rates over a span of 30 years (from 1987 to 2016) in Denmark. Furthermore, the impact of income and education was outlined.

Method

Patients were identified through linkage across Danish national registries from 1987 to 2016. We extracted data on the total number of inhabitants in Denmark aged ≥18 years, and used their age, sex, civil status, income and educational level for each calendar year. Data on socio economics were available from 1994. Income was defined by the average income over the prior 5 years and grouped into low (Q3). Educational level was divided into primary school, high school, bachelor's degree, or master's degree. We defined incident AF as all first-time in- and outpatient diagnoses of AF. The incidence rates of AF were age-standardized per 1000 person-years for each calendar year and calculated for men and women separately.

Results

A total of 6,968,997 Danish inhabitants aged ≥18 years contributed to the study population from 1987 to 2016, and 393,183 (6%) developed AF over the study period. The age-standardized incidence rates of AF per 1000 person-years increased from 1.23 (CI 1.15:1.30) to 4.05 (CI 3.93:4.17) for men and from 1.13 (CI 1.06:1.30) to 3.56 (CI 3.44:3.68) for women from 1987 to 2016. Income status and educational level influenced the age-standardized incidence rates more significantly in women than men. The incidence rate from 1994 to 2016 for women with low income increased by a factor of 2.1 from 2.0 (CI 1.89:2.21) to 4.36 (CI 4.03:4.73). However, the high income group increased by a factor of 1.6 (from 1.74 (CI 1.10:3.32) to 2.83 (CI 2.29:3.55) per 1000 person-years). Moreover, the incidence rate for women with low educational level increased from 1.60 (CI 0.95:5.97) to 4.01 (CI 3.80:4.23) per 1000 person-years. The high educational group increased only by 1.2 (from 2.55 (CI 0.77:10.38) to 3.1 (CI 3.32:4.11) per 1000 person-years).

Conclusion

In a nationwide population, the incidence rate of AF continued to increase during a 30-year period. All socioeconomic subgroups experienced an increase in AF incidence, but the impact of low socioeconomic status was more significant among women than among men. The progressive growth in AF incidence has significant public health implications.

Acknowledgement/Funding

Danish Heart Foundation
3268Impact of heart failure on prognosis compared to other complications in patients with diabetes mellitus type 2
Authors: Zareini B , Blanche P B , D'Souza Diederichsen M D D , Elmegaard Malik M E M , Lund Kristsensen S L K , Selmer C S , Koeber L K , Gislason G G , Torp-Pedersen C T P , Schou M S , Lamberts M L
Published: October 2019

Background

Recent studies have highlighted a high incidence of heart failure (HF) in type 2 diabetes mellitus (T2D), but it remains unclear how the development of HF affects prognosis compared to other T2D complications.

Purpose

To estimate the risk of death associated with the development of HF compared to ischemic heart disease (IHD), chronic kidney disease (CKD), stroke, and peripheral artery disease (PAD).

Methods

Incident T2D patients were identified in the period between 1998–2015, as all patients redeeming a first-time prescription of non-insulin glucose-lowering medication through Danish nationwide registers. Patients with a history of T2D complications and patients <18 years were excluded. Incident T2D complications were defined as HF, IHD, CKD, stroke, and PAD. We estimated the 5-year risk of death after the development of T2D complications according to the time since the onset of T2D by yearly landmark analyses. We estimated the survival probability and risk ratios (with T2D patients free of complications as reference) at each landmark year among patients who survived their T2D complication.

Results

A total of 153,403 patients with incident T2D (median age 64 years [interquartile range (IQR):55; 72] and 54% males) were included and followed for a median of 7.4 years (IQR: 4.3; 11.5). During follow-up, 48,087 (31%) patients died. Among the patients who survived, the following number of T2D complications were present at landmark year one vs. ten: HF: 1030 (0.7%) vs. 1082 (2.2%), IHD: 3622 (2.4%) vs. 6354 (12.6%), CKD: 905 (0.6%) vs. 2084 (4.1%), stroke: 1446 (1.0%) vs. 2387 (4.7%) and PAD: 1122 (0.8%) vs. 1517 (3.0%). HF posed the most unfavorable prognosis compared to other T2D complications (see figure). The 5-year risk of death associated with HF development one, five and ten years after T2D diagnosis was: 46.9 (95% confidence interval [CI]: 43.5; 50.3), 47.6 (95% CI: 44.8; 50.3) and 41.8 (95% CI: 38.0; 45.7) respectively. The 5-year risk ratios of death associated with HF development during one, five and ten years after T2D diagnosis compared with T2D patients free of complications was: 3.2 (95% CI, 3.2; 3.3), 3.0 (95% CI 2.9; 3.1) and 2.2 (95% CI, 2.1; 2.2), respectively.

Conclusion

While IHD was the most common complication at each landmark year, developing HF was associated with the highest risk of death compared to the other T2D complications.
3297Real-world outcome of applying the ESC 0/1-hour algorithm in clinical routine
Authors: Twerenbold R , Costabel J P , Nestelberger T , Campos R , Arbucci R , Boeddinghaus J , Puelacher C , Du Fay De Lavallaz J , Rubini Gimenez M , Koechlin L , Lambardi F , Resi S , Alves De Lima A , Trivi M , Mueller C
Published: October 2019

Background

The European Society of Cardiology (ESC) recommends the use of a 0/1h-algorithm for rapid triage of patients with suspected non-ST-elevation myocardial infarction (NSTEMI). To date, its impact on patient management and ultimately also safety when routinely applied in emergency departments (ED) is unknown. We therefore aimed to determine these important real-world outcome data.

Methods

In a prospective international multicenter study enrolling unselected patients presenting with suspected NSTEMI to the ED, we assessed the real-world feasibility, adherence, efficacy, effectiveness, and safety of the ESC 0/1h-algorithm using high-sensitivity cardiac troponin T embedded in routine clinical care. Patients with ST-segment elevation myocardial infarctions were excluded. Safety was quantified by the 30-day incidence of major adverse cardiac events (MACE, defined as the composite of cardiovascular death and myocardial infarction including the index event) in the rule-out group and in outpatients.

Results

Among 2296 patients, NSTEMI prevalence was 9.8% (224/2296). Feasibility was very high with a median time to the “1h-draw” of 65 minutes [q1 61, q3 72]. Adherence was very high with 94% (95% confidence interval [CI], 93–95) of patients managed without protocol violations. Effectiveness was very high: 98% (95% CI, 97–98) of patients triaged towards rule-out by the ESC 0/1h-algorithm did not require additional cardiac investigations including hs-cTnT measurements at later time points (e.g. 3–12h) or coronary CT-angiography in the ED. Median time to discharge from the ED was 150 [q1134, q3235] minutes in the overall population. The ESC 0/1h-algorithm triaged 62% (95% CI, 60–64) of patients towards rule-out and 13% (95% CI, 12–14) towards rule-in of NSTEMI. Overall, 71% (95% CI, 69–72) of patients underwent outpatient management (Figure 1). Safety of rule-out and outpatient management were very high with a 30-day MACE incidence of 0.2% (95% CI, 0–0.5) and 0.1% (95% CI, 0–0.2), respectively. These findings were consistent in several predefined subgroups.

Figure 1

Conclusions

These real-world data document the excellent feasibility, adherence, effectiveness, efficacy and safety of the ESC 0/1h-algorithm for the rapid management of patients presenting with suspected NSTEMI to the ED when applied in routine clinical practice.
333018F-Fluorodeoxyglucose Positron Emission Tomography Computed Tomography (PET/CT) for the diagnosis of prosthetic valve infective endocarditis (PVIE): a prospective multicenter study
Authors: Philip M , Tessonnier L , Mancini J , Mainardi J L , Lussato D , Cammillieri S , Weinmann P , Hagege A , Gouriet F , Camoin L , Casalta J P , Riberi A , Drancourt M , Lepidi H , Habib G
Published: October 2019

Background and objectives

18F-FDG PET/CT has recently been added as a major criterion in the ESC 2015 infective endocarditis (IE) guidelines, but the value of this new diagnostic algorithm has never been prospectively assessed.

Purposes

1. Primary objective: to assess the value of the new ESC criteria including 18F-FDG PET/CT in prosthetic valve infective endocarditis (PVIE).

2. Secondary objectives: to determine the reproducibility of 18F-FDG PET/CT; to assess its ability to predict embolic events.

Methods

Between 2014 and 2017, 175 patients with suspected PVIE were prospectively included in 3 French centers. After exclusion of patients with uninterpretable or not feasible PET/CT,115 patients were finally included in the analysis, including 91 definite IE and 24 rejected IE, as defined by an expert Consensus of Endocarditis Team after 3-month follow-up as Gold Standard

Nuclear data were blindly analyzed by two independent nuclear medicine physicians.

Patients follow-up was scheduled at one and three months after hospitalization

Results

Significant cardiac uptake by PET/CT (major criterion) was observed in 67 among 91 patients with definite PVIE and 6 patients with rejected IE (sensitivity 73.6%, specificity 75%, positive predictive value 91%, negative predictive value 42%). Considering cardiac uptake as a major criterion, the ESC 2015 classification increased the sensitivity of Duke criteria from 57 to 84% (p<0.001) but decreased its specificity from 84 to 70% (p<0.001).

Intraobserver reproducibility of cardiac uptake evaluation was good (kappa = 0.84) but inter observer reproductibility was less satisfactory (kappa = 0.63).

Embolic events occurred in 31 patients (27%) and were correlated with vegetation size by ECHO (p<0.001), Staphylococcus infection (p=0.003), and PET/CT cardiac uptake (p=0.02).

Conclusion

1. the value of PET CT and ESC criteria is confirmed and may allow earlier diagnosis of PVIE

2. PET CT is associated with an increased risk of false positive results probably related to the technical improvements

3. Reproducibility of nuclear measurements seems unsatisfactory, justifying efforts to standardize PET studies interpretation

4. Our study describes for the first time a positive correlation between a positive PET/Ct and occurrence of embolic events, warranting additional studies.