Central Core Research Articles

Core laboratory versus center-reported echocardiographic assessment of the native and bioprosthetic aortic valve

Abstract Background The use of a central echocardiographic core laboratory (ECL) is advised to minimize measurement variation and heterogeneity in clinical trials. Insights into quantitative differences between ECL and center-reported echocardiographic assessment of the native and bioprosthetic aortic valve are lacking. We aimed to explore clinically relevant differences between these evaluations. Methods Data were used from the PERIcardial SurGical AOrtic Valve ReplacemeNt (PERIGON) Pivotal Trial for the Avalus valve. In this trial, patients with an indication for surgical aortic valve replacement (SAVR) due to aortic stenosis or regurgitation (AR) were enrolled. Serial echocardiographic examinations were performed at each center and reanalyzed by an independent ECL. For the bioprosthetic valve analysis, postoperative data throughout 5-year follow-up were pooled. Differences between the ECL and the centers in continuous parameters were quantified in mean differences and intraclass correlation coefficients (ICCs). Between-center differences were illustrated by plotting standardized mean differences (SMDs) between centers and the ECL for the 10 sites that implanted the most prostheses. Agreement on AR, paravalvular leak (PVL), and prosthesis-patient mismatch (PPM) classification was investigated using Cohen’s kappa coefficients. Results The analysis on the native aortic valve was performed on 1118 patients. The relative mean difference was largest for the left ventricular outflow tract (LVOT) area, followed by stroke volume and effective orifice area (index), with center-reported values being 11-7% higher (Table 1). High ICCs of around 0.90 were observed for peak aortic jet velocity, mean pressure gradient, and the velocity-time integral across the aortic valve. More than 5000 echocardiograms were available for the bioprosthetic valve analysis. Therein, comparable results were observed. In Figure 1, differences in assessment on center level are illustrated. The SMDs for peak velocity were between 0 and 0.5 for all centers, while there was more heterogeneity between centers for other parameters. The kappa coefficient was 0.59 (95% confidence interval [CI] 0.56, 0.63) for agreement on native AR, 0.28 (95% CI 0.18, 0.37) for PVL, and 0.42 (95% CI 0.40, 0.44) for PPM. Conclusions For echocardiographic assessment of the native and bioprosthetic aortic valve, agreement between the ECL and the clinical centers varies by parameter and by center. There is high agreement on continuous-wave Doppler-related measurements. On the contrary, agreement is low for parameters that involve measurement of the LVOT diameter. These results provide important context for the interpretation of aortic valve performance in studies that lack central ECL evaluation.

Changes in echocardiographic and analytical parameters after iron replacement in stable heart failure patients. FER-STRAIN study

Abstract Background Iron deficiency replacement with intravenous ferric carboxymaltose (FCM) has demonstrated to improve clinical and prognostic parameters in patients with heart failure with reduced left ventricular ejection fraction (HFrEF). Improvement of myocardial contractility is proposed as possible hypothesis and strain could behave as an early and high sensitive parameter to assess this improvement in myocardial deformation due to increased iron availability after replacement of iron deficiency. Purpose Evaluate the effect of iron deficiency replacement with FCM in the strain of both ventricles in patients with stable HFrEF. Methods We performed an observational, analytical, longitudinal and prospective study that included 73 patients with stable HFrEF who presented iron deficiency without anemia defined as serum ferritin <100 ug/L or between 100 and 300 ug/L if the transferrin saturation was <20%. They were randomized 2:1 to iron replacement with FCM or control group. A central core lab, blinded to the treatment/control groups performed 3D echocardiograms and strain analysis. Analytical parameters and biomarkers were determined basal and four weeks after the randomization. Results Mean age of the study population was 70 years old, 77% were male, 75% had high blood pressure, 70% dyslipidemia and 41% diabetes. Of the total, 51 patients were assigned to the replacement group and 22 patients to the control group. Mean left ventricular ejection fraction (LVEF) was 33%, without basal differences between both groups. Four weeks after the randomization, a significant improvement of LVEF of 2.47±2.32% (p=0.018) was observed in the replacement group, as well as in the left ventricle global longitudinal strain (LV-GLS) of -0.96±2.08% (p=0.006). In blood tests, a significant improvement of ferritin (130.9±111.98mg/L, p<0.000), hemoglobin (0.3±0.7g/dL, p=0.027) and medium corpuscular volume (1.7±2.16fL, p=0.005), and also an increase of the biomarker myeloperoxidase (40.16±138.36pmol/L, p=0.02) were detected in the treatment group. Nevertheless, these changes were not observed in the control group. Conclusions In patients with stable HFrEF replacement of iron deficiency with FCM is associated with an improvement of myocardial contractility, of LVEF measured by 3D and LV-GLS.Variation of parametersLV-GLS before and after FCM

Large Range Curvature Measurement Using FBGs in Two-Core Fiber with Protective Coating

In this work, we propose a fiber Bragg grating (FBG)-based sensor for curvature measurements. Two gratings are inscribed through the protective coating in a specialty optical fiber using focused femtosecond laser pulses and point-by-point direct writing technology. One grating is inscribed on the central core adjacent to an air channel, while the other is inscribed on the eccentric core. The bending characteristics of the two-core fiber strongly depend on the bending direction due to the asymmetry of the fiber cores. A bending sensitivity of 58 pm/m−1 is achieved by the FBG in the eccentric fiber core over the curvature range of 0–50 m−1 . Temperature and humidity cross-sensitivity could be significantly reduced by analyzing the differences in peak shifts between the two gratings. The sensor features a large sensing range and good robustness due to the presence of its protective buffer coating, which makes it a good candidate for curvature sensing in engineering fields.

Improvement of myocardial contractility after iron replacement in stable heart failure patients

Abstract Background Iron deficiency replacement with intravenous ferric carboxymaltose (FCM) has demonstrated to improve clinical and prognostic parameters in patients with heart failure with reduced left ventricular ejection fraction (HFrEF). Improvement of myocardial contractility is proposed as possible hypothesis and strain could behave as an early and high sensitive parameter to assess this improvement in myocardial deformation due to increased iron availability after replacement of iron deficiency. Purpose Evaluate the effect of iron deficiency replacement with FCM in the strain of both ventricles in patients with stable HFrEF. Methods Observational, analytical, longitudinal and prospective study that included 73 patients with stable HFrEF who presented iron deficiency without anemia defined as serum ferritin <100 ug/L or between 100 and 300 ug/L if the transferrin saturation was <20%. They were randomized 2:1 to iron replacement with FCM or control group. A central core lab, blinded to the treatment/control groups, performed 3D echocardiograms and strain analysis basal and four weeks after the randomization. Results Mean age of the study population was 70 years old, 77% were male, 75% had high blood pressure, 70% dyslipidemia and 41% diabetes. Of the total, 51 patients were assigned to the replacement group and 22 patients to the control group. Mean left ventricular ejection fraction (LVEF) was 33%, without basal differences between both groups. Four weeks after the randomization, a significant improvement of LVEF of 2.47±2.32% (p=0.018) was observed in the replacement group, as well as in the left ventricle global longitudinal strain (LV-GLS) of -0.96±2.08% (p=0.006). Nevertheless, these changes were not observed in the control group. Conclusions In patients with stable HFrEF replacement of iron deficiency with FCM is associated with an improvement of myocardial contractility, of LVEF measured by 3D and LV-GLS.Variation of parametersLV-GLS before and after FCM

Mechanical dyssynchrony and response to cardiac resynchronization therapy in heart failure patients with right ventricular pacing: a pre-specified subgroup analysis of the BUDAPEST CRT Upgrade trial

Abstract Introduction The BUDAPEST CRT Upgrade trial has established the strong clinical benefit of upgrading heart failure patients with a reduced left ventricular (LV) ejection fraction (HFrEF) and a high right ventricular pacing (RVP) burden to cardiac resynchronization therapy with defibrillator (CRT-D). Importantly, however, the CRT upgrade response is not homogeneous regarding LV reverse remodeling and associated clinical outcomes. The presence of mechanical dyssynchrony (MD) assessed by echocardiography has been linked to more CRT benefits; still, its change in response to CRT and added prognostic value in HFrEF patients with high RVP are scarcely investigated. Purpose Accordingly, we aimed to assess the prevalence, clinical characteristics, CRT response rate, and prognostic value of RVP-induced MD in the BUDAPEST CRT Upgrade cohort. Methods The multicentre, randomized, controlled trial enrolled 360 HFrEF patients with a pacemaker or implantable cardioverter defibrillator (ICD) and significant RVP (≥ 20%) who were randomly assigned to receive CRT-D upgrade or ICD in a 3:2 ratio. Protocol echocardiography was performed at baseline and at 12-month follow-up visits and was evaluated at a central core lab. Beyond LV end-diastolic (EDV) and end-systolic volumes (ESV), longitudinal strain-derived septal deformation patterns by speckle tracking were assessed to determine the presence of RVP-induced MD. The endpoints were volumetric non-response (defined by a relative decrease in LV ESV <15%) and the composite of volumetric non-response or HF hospitalization. Results The echocardiographic assessment was feasible in 325 patients at baseline; 133 (41%) patients presented with MD. Females were more likely to present with MD (female vs. male, 65% vs. 38%, p=0.003). MD patients had higher LV EDV (MD vs. no-MD, 248±78 vs. 219±78 mL, p=0.001) and LV ESV (190±67 vs. 165±64 mL, p<0.001) at baseline. In the CRT-D group, 126 (75%) patients were volumetric responders, and 41 (25%) were non-responders at 12 months. CRT patients with baseline MD were less likely to experience volumetric non-response (OR 0.35 [95% CI 0.15-0.82], p=0.015) or the composite endpoint (OR 0.37 [95% CI 0.17-0.77], p=0.008). Out of 57 CRT patients with baseline MD who had follow-up assessment available, 52 (91%) patients had a favorable change: the MD pattern disappeared. Patients with MD resolution at 12 months were less likely to experience volumetric non-response or the composite endpoint (OR 0.39 [95% CI 0.17-0.93], p=0.034; OR 0.38 [95% CI 0.16-0.86], p=0.021, respectively). CRT patients with resolved MD were less likely of ischemic etiology and had 100% posterior or lateral LV lead location. Conclusions The presence of RVP-induced MD and its resolution is associated with better clinical response in HFrEF patients undergoing CRT-D upgrade. MD assessment can refine patient selection algorithms of CRT.Figure 1

The impact of transcatheter aortic valve replacement on changes of coronary computed tomography-derived fractional flow reserve

Background The effect of transcatheter aortic valve replacement (TAVR) on changes of computed tomography-derived fractional flow reserve (CT-FFR) values was controversial. Thus, we aimed to identify the impact of TAVR on changes of CT-FFR values, plaque characteristics, and the associated clinical impact. Methods This single-center observational study included 39 consecutive patients with severe aortic valve disease undergone TAVR between August 2019 and April 2023, whom were performed with preoperative and postoperative coronary CT angiography (CCTA). The computation of CT-FFR and plaque characteristics was performed by an independent central core laboratory. Results Each patient underwent CCTA and CT-FFR assessment without encountering any complications. Notably, both at discharge and six months post-TAVR, there was a significant improvement observed in the New York Heart Association (NYHA) functional classification, left ventricular fractional shortening, and ejection fraction compared to pre-operative levels. The CT-FFR for left anterior descending artery (LAD), left anterior descending artery (LCX), and right coronary artery (RCA) had no obvious change at discharge compared to pre-operation (0.92 ± 0.05 vs. 0.93 ± 0.05, p = 0.109; 0.96 ± 0.03 vs. 0.95 ± 0.03, p = 0.523; 0.97 ± 0.04 vs. 0.97 ± 0.03, p = 0.533; respectively). Furthermore, TAVR did not exert a significant impact on plaque burden during the perioperative period. Conclusions Our report suggested that TAVR did not significantly affect coronary CT-FFR measurements and plaque characteristics in the perioperative period, and furthermore, the patients’ cardiac function showed gradual improvement in the short-term following discharge.

Unveiling non-monochromatic modes and nonlinearity in Piet Hein quantum semiconductor waveguides

We investigate the propagation characteristics of transverse electric (TE) and transverse magnetic (TM) modes in a semiconductor quantum plasma-filled coaxial waveguide with a Piet Hein cross-section. The unique geometry of the Piet Hein cross-section offers intriguing possibilities for tailoring modal properties and exploiting novel nonlinear phenomena. Using analytical and numerical methods, we unveil the non-monochromatic behaviour of TE and TM modes, characterized by distinct peaks and troughs in their field components. The Ez\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$E_{z}$$\\end{document} component of the TM mode exhibits a suppressed field within the central core and higher concentration in the cladding region, potentially minimizing energy loss within the waveguide. The Eρ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$E_{\\rho }$$\\end{document} component exhibits pronounced oscillations near the waveguide boundaries, suggesting constructive and destructive interference patterns. The Eξ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$E_{\\xi }$$\\end{document} component displays a non-monotonic behaviour with multiple pits and bumps, highlighting the interplay between the TE mode, the Piet Hein geometry, and the semiconductor quantum plasma properties. The Bρ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$B_{\\rho }$$\\end{document} component of the TM mode exhibits a non-monochromatic behaviour with multiple maxima and minima, attributed to the complex interactions between propagating waves with different phase shifts. The Bξ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$B_{\\xi }$$\\end{document} component exhibits a non-uniform distribution with distinct pits and bumps, with a resurgence towards the waveguide edges potentially due to higher-order mode contributions and local field enhancement effects. Our findings pave the way for the development of novel photonic devices with enhanced functionalities based on Piet Hein semiconductor quantum plasma waveguides.

IMPLEMENTATION OF INTERNATIONAL EXPERIENCE OF STATE PROTECTION OF NATIONAL VALUES IN UKRAINE

The author of the article reveals the purpose of implementing the international experience of the system of state protection of national values through the prism of two important trends that should be implemented and and enshrined in the practice of state-building processes in modern Ukraine. One of them stipulates that national values are the central core of the national security system security system, they define the triad of ‘values-interests-goals’. The second trend defines the system of creating mechanisms for legislative support of guaranteeing and protecting of national values, which is embodied in the systemic nature of the state policy on national development and is the actual consolidation of the civilisational civilisational choice of the Ukrainian nation at the level of legal acts. The purpose of the article is to analyse practical aspects of implementation of the state mechanisms for protection of national values in foreign countries and their implementation in the Ukrainian State. The author emphasises that national values of of modern Ukraine should not be subject to political bargaining, speculation, etc. They are are always an element of political struggle. Without this, political processes are impossible, and therefore, national values should be defined and prohibited for political speculation on them, which, by the way, requires the development of an institution of for their criminal law protection; and - to have its own system of mechanisms of legislative protection. It is determined that the first step towards the implementation of the experience of foreign countries in protecting national values should be the introduction of an all-Ukrainian analytical study of the system of national values. It should should be based on long-term and medium-term forecasts of domestic development and the development of the system of world politics, its specific regional and functional subsystems. This means that the full potential of national research institutes in the field of public opinion, civil society, and sociological research should be used to society, and sociological research should be directed within the framework of a single state policy to study and define national values.

3D Cryo-Electron Microscopy Reveals the Structure of a 3-Fluorenylmethyloxycarbonyl Zipper Motif Ensuring the Self-Assembly of Tripeptide Nanofibers.

Short peptide-based supramolecular hydrogels appeared as highly interesting materials for applications in many fields. The optimization of their properties relies mainly on the design of a suitable hydrogelator through an empirical trial-and-error strategy based on the synthesis of various types of peptides. This approach is in part due to the lack of prior structural knowledge of the molecular architecture of the various families of nanofibers. The 3D structure of the nanofibers determines their ability to interact with entities present in their surrounding environment. Thus, it is important to resolve the internal structural organization of the material. Herein, using Fmoc-FFY tripeptide as a model amphiphilic hydrogelator and cryo-EM reconstruction approach, we succeeded to obtain a 3.8 Å resolution 3D structure of a self-assembled nanofiber with a diameter of approximately 4.1 nm and with apparently "infinite" length. The elucidation of the spatial organization of such nano-objects addresses fundamental questions about the way short amphiphilic N-Fmoc peptides lacking secondary structure can self-assemble and ensure the cohesion of such a lengthy nanostructure. This nanofiber is organized into a triple-stranded helix with an asymmetric unit composed of two Fmoc-FFY peptides per strand. The three identical amphiphilic strands are maintained together by strong lateral interactions coming from a 3-Fmoc zipper motif. This hydrophobic core of the nanofiber is surrounded by 12 phenyl groups from phenylalanine residues, nonplanar with the six Fmoc groups. Polar tyrosine residues at the C-term position constitute the hydrophilic shell and are exposed all around the external part of the assembly. This fiber has a highly hydrophobic central core with an internal diameter of only 2.4 Å. Molecular dynamics simulations highlight van der Waals and hydrogen bonds between peptides placed on top of each other. We demonstrate that the self-assembly of Fmoc-FFY, whether induced by annealing or by the action of a phosphatase on the phosphorylated precursor Fmoc-FFpY, results in two nanostructures with minor differences that we are unable to distinguish.

A Diphosphonic Acid-Based Interlayer for Highly Efficient and Stable Inverted Perovskite Solar Cells.

We investigate an interlayer of 6,6'-bis(4-(bis(4-methoxyphenyl)amino)phenyl)-[1,1'-binaphthalene]-(2,2'-diyl)bis(oxy)bis(propane-3,1-diyl)bis(phosphonic acid) (BINOL-PA) with undoped poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) coverage. The incorporation of the 1,10-bi-2-naphthol central core enhances π-π stacking and reduces charge recombination at the interface. Compared to PTAA alone (0.95 eV), BINOL-PA/PTAA exhibits a shorter distance from the Fermi energy (EF) to the valence-band maximum (VBM) (0.36 eV). Two phosphoric acid units in BINOL-PA fine-tune the molecular dipoles. Theoretical calculations reveal electrostatic surface potential differences between BINOL-PA and PTAA in their backbone structure. Open-circuit voltage decay (OCVD) and electrochemical impedance spectroscopy (EIS) results suggest suppressed interface recombination. The photovoltaic conversion efficiency (PCE), short-circuit current density (JSC), open-circuit voltage (VOC), and fill factor (FF) for the BINOL-PA/PTAA device are measured as 21.02%, 22.67 mA cm-2, 1.12 V, and 82.8%, respectively, all higher than those achieved by the PTAA device with a PCE of 18%. BINOL-PA/PTAA significantly elevates VOC and FF values compared with dopant-free PTAA alone. The champion device retains over 89% of its initial PCE after being exposed to an ambient environment without encapsulation for more than 30 days. The thermal aging test conducted under a nitrogen atmosphere demonstrates that the efficiency retention rate for BINOL-PA/PTAA displays 60% of its initial efficiency after 1500 h.

In Silico Design, Chemical Synthesis, Biophysical and in Vitro Evaluation for the Identification of 1-Ethyl-1H-Pyrazolo[3,4-b]Pyridine-Based BRD9 Binders.

In this work, we report the identification of novel bromodomain-containing protein 9 (BRD9) binders through a virtual screening based on our developed 3D structure-based pharmacophore model. The in silico workflow here described led to the identification of a promising initial hit (1) featuring the 1-ethyl-1H-pyrazolo[3,4-b]pyridine motif which represented an unexplored chemotype for the development of a new class of BRD9 ligands. The encouraging biophysical results achieved for compound 1 prompted us to explore further tailored structural modification around the C-4 and C-6 positions of the central core. Hence, the design and synthesis of a set of 19 derivatives (2-20) were performed to extensively investigate the chemical space of BRD9 binding site. Among them, four compounds (5, 11, 12, and 19) stood out in biophysical assays as new valuable BRD9 ligands featuring IC50 values in the low-micromolar range. Noteworthy, a promising antiproliferative activity was detected in vitro for compound 5 on HeLa and A375 cancer cell line. The successful combination and application of in silico tools, chemical synthesis, and biological assays allowed to identify novel BRD9 binders and to expand the arsenal of promising chemical entities amenable to the recognition of this important epigenetic target.

Efficacy of Phthalocyanine‐Based Catalysts in Electrochemical Sensors: A Comprehensive Review

AbstractMetal phthalocyanines (MPcs) are promising materials for electrochemical sensing due to their physicochemical properties, including redox activity, structural versatility, and chemical stability. These materials can incorporate various metals into their central core, ensuring tunable catalytic activity and enhanced sensitivity and selectivity. This makes MPcs valuable for designing advanced electrochemical sensors, which require precise and reliable performance for applications ranging from environmental monitoring to biomedical diagnostics. This review discusses the advancements in MPc‐based catalysts for electrochemical sensors, focusing on their superior catalytic properties, stability under diverse operating conditions, and high functionalization potential. The unique redox behavior of the metal center in MPcs ensures improved detection capabilities of analytes like biomolecules, heavy metal ions, and environmental pollutants, positioning MPc materials as a cornerstone in future sensor technology. MPc‐based sensors have diverse applications across various fields, including environmental sensing, medical diagnostics, and industrial process monitoring. Recent reports highlight the practical relevance and growing importance of MPcs in real‐world applications. Challenges associated with MPc‐based sensors include scalability, environmental stability, and integration into practical devices. The review concludes with a discussion on the future outlook on MPcs in the design and development of next‐generation electrochemical sensors, paving the way for more efficient, cost‐effective, and reliable detection technologies.

A leap forward in the optimization of organic solar cells: DFT-based insights into the design of NDI-based donor-acceptor-donor structures

This study presents the design and analysis of four novel small molecules with a donor-acceptor-donor (D-A-D) architecture, incorporating naphthalene diimide (NDI) as the central electron acceptor core, flanked by different electron-donating units: 4H-dithieno [3,2-b:2′,3′-d]pyrrole (DTP), isomeric 7H-dithieno-[2,3-b:3′,2′-d]pyrrole (iso-DTP), phenothiazine, and diphenylamine. The optical, electronic, and photovoltaic properties of these structures were evaluated using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) at the WB97XD/6-311+G (d,p) theoretical level. The selected calculation method showed excellent agreement with experimental data for the synthesized NDI-C3 molecule, validating the computational approach. Our findings highlight the significant role of electron-donating groups in enhancing photovoltaic properties, including increased open-circuit voltage, improved charge density distribution, and enhanced parameters such as fill factor, radiation lifetime, and light harvesting efficiency compared to the NDI-C3 structure. These promising results underscore the potential of our designed molecules for efficient application in organic solar cells and their significant contribution to the advancement of photovoltaic technology.

Delayed cyst formation after radiosurgery for arteriovenous malformation: A case report and critical review

Background: Stereotactic radiosurgery (SRS) is a validated treatment option for cerebral arteriovenous malformations (AVMs), even if a greater knowledge of its potential delayed complications is still being acquired. Case Description: A 49-year-old man suffered multiple episodes of cerebral hemorrhage in an approximate 10-year follow-up interval in the context of a left central core AVM with deep venous drainage into the internal cerebral veins (Spetzler Martin Grade 4) despite being treated with gamma knife radiosurgery at two separate timepoints, and with an almost complete obliteration confirmed. Approximately 10 years after the first radiosurgery treatment, he developed severe motor aphasia, Grade 3 right hemiparesis, progressive confusion, and memory deficits. Cerebral imaging revealed cystic degeneration in the AVM’s periphery. Cyst fenestration and cystoperitoneal shunt were attempted. The treatments were temporarily effective, but a progressive cyst enlargement recurred with clinical deterioration. The patient was therefore proposed for surgical mass and cyst excision through an interhemispheric transcallosal approach. The postoperative magnetic resonance imaging showed complete removal of the lesion, and an uneventful post-operative course ensued. At the 6-month follow-up, our patient experienced a noticeable improvement in his speech, power, dexterity and was able to walk autonomously. Conclusion: Cystic degeneration of AVMs is a possible long-term complication after SRS. Long-term follow-up and data on such patients remain crucial, even with evidence of complete nidal obliteration.

Evaluation of space efficiency criteria in high-rise buildings based on functions: a case study of Türkiye

ABSTRACT High-rise buildings have become a significant solution to address the challenges posed by the rapid growth of urban populations and space limitations in cities. Efficient planning and design of these buildings, aiming to achieve more productivity, can be realized through ensuring space efficiency. This research compares architectural and structural design criteria affecting space efficiency in high-rises based on their functions, aiming to assess the degree of correlation among these criteria, space efficiency, and their interrelations. Currently, no studies examine the differences or similarities in space efficiency of high-rise buildings based on their functions. Additionally, selecting buildings from the same region as samples is a unique aspect of this study. Employing a case study method, the analysis encompasses 42 high-rises in Türkiye, ranging from 100 m to 300 m, and utilizes correlation analysis methods to examine the data. The comprehensive review of space efficiency in high-rises, based on their functions, yielded the following results: (i) Space efficiency ranged from 82.7% to 65.2% in high-rise case studies with different functions, with an average of 73.2%. (ii) A significant majority (83%) of the buildings followed orthogonal designs. (iii) Central core floor planning emerged as the preferred approach. (iv) Increasing elevator density reduced space efficiency. (v) Office buildings favored reinforced concrete frame systems, while residential buildings commonly used reinforced concrete shear wall systems. (vi) As building height increased, elevator and core areas expanded. These findings provide guidance for future high-rise building design and planning.

Going beyond carbon: Influence of structural parameters on the environmental impacts of typical building structures

The construction sector has a large impact on the environment, be it climate change, biodiversity loss or resources depletion. Part of those impacts comes from construction materials, and more specifically, concrete and steel building structures. Early-stage design tools including environmental damage assessment are therefore required to achieve sustainable construction practices. This article presents a parametric approach aiming at studying the influence of early-stage structural parameters on the environmental impacts of a structure. The developed methodology combines parametric structural design with a multicriteria cradle-to-grave Life Cycle Assessment, applied to typical housing structures such as grid based beam column structures with a central core for lateral stability. Results show that span, number of levels and materials greatly influence the environmental impacts of considered structures. Climate change scores per floor area range from 80 kgCO2/m2 for short span timber structure to 215 kgCO2/m2 for long span steel buildings with few levels. Beams and slabs have the largest contribution in such impacts. Changing the production processes of materials is a way to reduce greenhouse gas emissions. However, decarbonizing steel production processes or reducing the cement content of concrete participate in burdenshifting with increased scores in several impact categories, such as carcinogenic toxicity or ozone depletion.

Non-fused nonfullerene acceptors withasymmetric benzo[1,2-b:3,4-b', 6,5-b"]trithiophene (BTT) central donor core and different acceptor terminal units for organic solar cells.

Here in, we have designed two new unfused non-fullerene small molecules based on asymmetric benzo[1,2-b:3.4-b', 6,5-b"]trithiophene (BTT) central donor core and different terminal units, i.e. 2-(3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile (NFA-4) and 1,3-diethyl-2-thioxodi hydropyrimidine-4,6(1H,5H)-dione (NFA-5) and their optical and electrochemical properties were investigated. Employing a wide band-gap copolymer D18, the binary D18: NFA-4 and D18:NFA-5 bulk heterojunction-based organic solar cells realized an overall power conversion efficiency of about 17.07% and 11.27 %, respectively. The higher value of power conversion efficiency for the NFA-4-based organic solar cells, as compared to the NFA-5 counterpart, is attributed to the enhanced values of short circuit current, open circuit voltage, and fill factor. After the incorporation of NFA-5 into the binary bulk heterojunction D18:NFA-4, the ternary organic solar cells attained a power conversion efficiency of 18.05 %, which is higher than that for the binary counterparts and attributed to the increased values of short circuit current, fill factor, and open circuit voltage. The increased value of short circuit current is associated with the effective utilization of excitons through the energy transfer from the NFA-5 to NFA-4 as the NFA-4 exhibits a more significant dipole moment than the NFA-5 and is effectively dissociated into a free charge carrier.

DYNAMICS OF THE STRUCTURE OF SOCIAL REPRESENTATIONS OF ARTIFICIAL INTELLIGENCE IN THE CONTEXT OF SOCIAL CHANGE

The aim of the research is to study the dynamics of the structure of social representations of artificial intelligence (AI) among non-professionals. 258 students of different faculties aged from 18 to 24 took part in this study. The study took place in two stages: 1) November 2021, 2) March 2022. To identify the structure of the social perception of AI, the Vergès method was used based on the material of free associations. At the second stage, the level of respondents’ concern about the events of recent weeks in the economic and political spheres was additionally monitored. It was found that elements related to expectations of AI capabilities have strengthened the central core of the representation. Words with a connotation of danger appear in the periphery elements. Probably it is caused by both the activities of communication agents and the context of disturbing social changes. Against this background, it is important to enrich the knowledge of AI among ordinary people in order to form an adequate level of trust and distrust of recommendations based on it.

The synthesis and structures of four new copper(II) adamantoid clusters

Four new copper(II) compounds with an inorganic, adamantane-like core have been prepared and structurally characterized: [(2-aminopyridine)4(μ2-Br)6Cu4(μ4-O)].(2-aminopyridinium) bromide monohydrate (1), the open cage structure (2-aminopyridinium) [(2-aminopyridine)4(μ2-Cl)5(Cl)2Cu4(μ4-O)] (2), bis(2-amino-5-methylpyridinium) [(2-amino-5-methylpyridine)2(μ2-Cl)6(Cl)2Cu4(μ4-O)] (3) and the co-crystal [(2-amino-5-fluoropyridine)4(μ-Cl)6Cu4(μ4-O)]2 [(2-amino-5-fluoropyridine)4Cu2Cl4] (4). All four include additional components in the lattice ranging from a non-coordinated ancillary ligand (1) to a co-crystallization with a distinct coordination complex (4). The compounds crystallize as: 1, triclinic, P-1; 2, monoclinic, P21/c; 3, monoclinic, P21/c; 4, triclinic, P-1. Analysis of the geometric parameters within the adamantoid cores of the compounds indicates significant structural resilience as parameters are little changed by the presence of additional components in the lattice. Breaking of the central core by coordination of an additional chloride ion in 2 significantly affects the geometry about those two Cu(II) ions but has little effect on other parts of the core.

Domain swapping: a mathematical model for quantitative assessment of structural effects.

The domain-swapping mechanism involves the exchange of structural elements within a secondary or supersecondary structure between two (ormore) proteins. The present paper proposes to interpret the domain-swapping mechanism using a model that assesses the structure of proteins (and complexes) based on building the structure of a common hydrophobic core in a micelle-like arrangement (a central hydrophobic core with a polar shell in contact with polar water), which has a considerable impact on the stabilisation of the domain structure built by domain swapping. Domains with a hydrophobicity system that is incompatible with the micelle-like structure have also been identified. This incompatibility is the form of structural codes related to biological function.