Domain Orientation Research Articles

Maximal domains for strategy-proof pairwise exchange

We analyze centralized markets for indivisible objects without money through pairwise exchange when each agent initially owns a single object. We consider rules that for each profile of agents preferences select an assignment of the objects to the agents. We present a family of domains of preferences (minimal reversal domains) that are maximal rich domains for the existence of rules that satisfy individual rationality, efficiency, and strategy-proofness. Each minimal reversal domain is defined by a common ranking of the set of objects, and agents’ preferences over admissible objects coincide with such common ranking but for a specific pair of objects.

Data Augmentation for Deep Receivers

Deep neural networks (DNNs) allow digital receivers to learn to operate in complex environments. To do so, DNNs should preferably be trained using large labeled data sets with a similar statistical relationship as the one under which they are to infer. For DNN-aided receivers, obtaining labeled data conventionally involves pilot signalling at the cost of reduced spectral efficiency, typically resulting in access to limited data sets. In this paper, we study how one can enrich a small set of labeled pilots data into a larger data set for training deep receivers. Motivated by the widespread use of data augmentation techniques for enriching visual and text data, we propose dedicated augmentation schemes that exploits the characteristics of digital communication data. We identify the key considerations in data augmentations for deep receivers as the need for domain orientation, class (constellation) diversity, and low complexity. Following these guidelines, we devise three complementing augmentations that exploit the geometric properties of digital constellations. Our combined augmentation approach builds on the merits of these different augmentations to synthesize reliable data from a momentary channel distribution, to be used for training deep receivers. Furthermore, we exploit previous channel realizations to increase the reliability of the augmented samples. The superiority of our approach is numerically evaluated for training several deep receiver architectures in different channel conditions. We consider both linear and non-linear synthetic channels, as well as the COST 2100 channel generator, for both single-input single-output and multiple-input multiple-output scenarios. We show that our combined augmentations approach allows DNN-aided receivers to achieve gains of up to 1 dB in bit error rate and of up to ×3 in spectral efficiency, compared to regular non-augmented training. Moreover, we demonstrate that our augmentations benefit training even as the number of pilots increases, and perform an ablation study on the different augmentations, which shows that the combined approach surpasses each individual augmentation technique.

Reduced-cost microwave modeling using constrained domains and dimensionality reduction

Development of modern microwave devices largely exploits full-wave electromagnetic (EM) simulations. Yet, simulation-driven design may be problematic due to the incurred CPU expenses. Addressing the high-cost issues stimulated the development of surrogate modeling methods. Among them, data-driven techniques seem to be the most widespread owing to their flexibility and accessibility. Nonetheless, applicability of approximation-based modeling for real-world microwave components is hindered by a high nonlinearity of the system characteristics, dimensionality issues, and broad ranges of operating parameters the model should cover to make it practically useful. Performance-driven modeling frameworks deliver a partial mitigation of these problems through appropriate spatial orientation of the metamodel domain, which only encapsulates high-quality designs and not the entire space. Unfortunately, the initial model setup cost is high, as defining the domain requires database designs that need to be a priori acquired. This paper introduces a novel approach, where the database designs are replaced by random observables, and dimensionality of the domain is reduced using spectral analysis thereof. The major contributions of the work include implementation of the explicit dimensionality reduction of the confined surrogate model domain and introducing this concept into a complete cost-efficient framework for modeling of microwave components. Comprehensive benchmarking demonstrates excellent performance of the introduced framework, both in terms of predictive power of the rendered surrogates, their scalability properties, as well as low computational overhead associated with the model setup.

Facet-engineered growth of non-layered 2D manganese chalcogenides

Non-layered two-dimensional (2D) materials have sparked much interest recently due to their atomic thickness, large surface area, thickness- and facet-dependent properties. Currently, these materials are mainly grown from wet-chemistry methods but suffer from small size, low quality, and multi-facets, which is a major challenge hindering their facet-dependent property studies and applications. Here, we report the facet-engineered growth (FEG) of non-layered 2D manganese chalcogenides (MnX, X ​= ​S, Se, Te) based on the chemical vapor deposition method. The as-grown samples exhibit large-area surfaces of single facet, high-crystallinity, and ordered domain orientation. As a proof-of-concept, we show the facet-dependent electrocatalytic property of non-layered 2D MnSe, proving they are ideal candidates for fundamental research. Furthermore, we elucidate the underlying mechanism of FEG during the vapor growth process by the interfacial energy derived nucleation models. The method developed in this work provides new opportunities for regulating and designing the structure of 2D materials.

Fairness and efficiency of the random serial dictatorship on preference domains with a tier structure

In this note, we study the envy-freeness and ordinal efficiency of the random serial dictatorship (RSD) rule on preference domains with a tier structure. Specifically, we obtain that the RSD rule is envy-free on restricted tier preference domains. For the ordinal efficiency axiom, we show that the almost-singleton condition is not sufficient for the RSD rule to be ordinally efficient. For assignment problems on the restricted tier preference domains, we characterize the condition under which the RSD rule is ordinally efficient.

Crystal structures of the DExH-box RNA helicase DHX9.

DHX9 is a DExH-box RNA helicase with versatile functions in transcription, translation, RNA processing and regulation of DNA replication. DHX9 has recently emerged as a promising target for oncology, but to date no mammalian structures have been published. Here, crystal structures of human, dog and cat DHX9 bound to ADP are reported. The three mammalian DHX9 structures share identical structural folds. Additionally, the overall architecture and the individual domain structures of DHX9 are highly conserved with those of MLE, the Drosophila orthologue of DHX9 previously solved in complex with RNA and a transition-state analogue of ATP. Due to differences in the bound substrates and global domain orientations, the localized loop conformations and occupancy of dsRNA-binding domain 2 (dsRBD2) differ between the mammalian DHX9 and MLE structures. The combined effects of the structural changes considerably alter the RNA-binding channel, providing an opportunity to compare active and inactive states of the helicase. Finally, the mammalian DHX9 structures provide a potential tool for structure-based drug-design efforts.

Associations among body mass index, handgrip strength, and cognitive impairment in older men and women in India

BackgroundThis study examined the associations among body mass index (BMI), handgrip strength (HGS) and cognitive impairment among older adults in India. We also assessed whether these associations vary by gender. MethodsWe used data from baseline wave of the Longitudinal Aging Study in India (2017–18) with a sample of 31,464 adults age 60 and above. Cognitive impairment was assessed using different domains of cognition, including memory, orientation, arithmetic functioning, and visuospatial and constructional ability. We used multivariable logistic regression and interaction analyses to test the research hypotheses. ResultsOlder women had 2.25 times the odds of cognitive impairment than older men [AOR: 2.25; CI: 2.01–2.53]. The odds of cognitive impairment were 1.36 times among underweight older adults [AOR: 1.36; CI: 1.23–1.50], 0.72 times among overweight [AOR: 0.72; CI: 0.62–0.83], and 0.66 times among obese older adults [AOR: 0.66; CI: 0.51–0.84] compared to peers with normal BMI. Underweight women had 3.14 times the odds of being cognitively impaired [AOR: 3.14; CI: 2.67–3.68] compared to older men with normal BMI. Further, older men who were underweight and had a weak HGS had higher odds of cognitive impairment than older men with a normal BMI and strong HGS. Conversely, older women who were overweight or obese and had strong HGS reported lower odds of cognitive impairment than older women with normal BMI and strong HGS. ConclusionsThat the association between BMI and cognitive impairment differs between men and women and by HGS gives health care providers and practitioners additional information needed to identify groups of older adults most susceptible to cognitive impairment. In particular, gender specific policies and an assessment of HGS may be useful when crafting interventions to minimize the negative consequences of varying body types on later life cognitive function.

Fabrication of Pillar‐Cage Fluorinated Anion Pillared Metal–Organic Frameworks via a Pillar Embedding Strategy and Efficient Separation of SO2 through Multi‐Site Trapping

AbstractFlue gas desulfurization is crucial for both human health and ecological environments. However, developing efficient SO2 adsorbents that can break the trade‐off between adsorption capacity and selectivity is still challenging. In this work, a new type of fluorinated anion‐pillared metal–organic frameworks (APMOFs) with a pillar‐cage structure is fabricated through pillar‐embedding into a highly porous and robust framework. This type of APMOFs comprises smaller tetrahedral cages and larger icosahedral cages interconnected by embedded [NbOF5]2− and [TaOF5]2− anions acting as pillars. The APMOFs exhibits high porosity and density of fluorinated anions, ensuring exceptional SO2 adsorption capacity and ultrahigh selectivity for SO2/CO2 and SO2/N2 gas mixtures. Furthermore, these two structures demonstrate excellent stability towards water, acid/alkali, and SO2 adsorption. Cycle dynamic breakthrough experiments confirm the excellent separation performance of SO2/CO2 gas mixtures and their cyclic stability. SO2‐loaded single‐crystal X‐ray diffraction, Grand canonical Monte Carlo (GCMC) simulations combined with density functional theory (DFT) calculations reveal the preferred adsorption domains for SO2 molecules. The multiple‐site host–guest and guest‐guest interactions facilitate selective recognition and dense packing of SO2 in this hybrid porous material. This work will be instructive for designing porous materials for flue gas desulfurization and other gas‐purification processes.

Fabrication of Pillar-Cage Fluorinated Anion Pillared Metal-Organic Frameworks via a Pillar Embedding Strategy and Efficient Separation of SO2 through Multi-Site Trapping.

Flue gas desulfurization is crucial for both human health and ecological environments. However, developing efficient SO2 adsorbents that can break the trade-off between adsorption capacity and selectivity is still challenging. In this work, a new type of fluorinated anion-pillared metal-organic frameworks (APMOFs) with a pillar-cage structure is fabricated through pillar-embedding into a highly porous and robust framework. This type of APMOFs comprises smaller tetrahedral cages and larger icosahedral cages interconnected by embedded [NbOF5]2- and [TaOF5]2- anions acting as pillars. The APMOFs exhibits high porosity and density of fluorinated anions, ensuring exceptional SO2 adsorption capacity and ultrahigh selectivity for SO2/CO2 and SO2/N2 gas mixtures. Furthermore, these two structures demonstrate excellent stability towards water, acid/alkali, and SO2 adsorption. Cycle dynamic breakthrough experiments confirm the excellent separation performance of SO2/CO2 gas mixtures and their cyclic stability. SO2-loaded single-crystal X-ray diffraction, Grand canonical Monte Carlo (GCMC) simulations combined with density functional theory (DFT) calculations reveal the preferred adsorption domains for SO2 molecules. The multiple-site host-guest and guest-guest interactions facilitate selective recognition and dense packing of SO2 in this hybrid porous material. This work will be instructive for designing porous materials for flue gas desulfurization and other gas-purification processes.

A - 08 Does the Cognitive Change Index Predict Progression of Clinical Dementia Status? Longitudinal Analysis in a Demographically Diverse Aging Cohort.

The Cognitive Change Index (CCI; Rattanabannakit et al., 2016) is a widely used measure of self-perceived cognitive functioning. There are several versions, the most common being a 20-item version, which queries memory, executive functioning, and language concerns (CCI-20), and a 12-item version (CCI-12), which includes only memory concerns. Little is known about how the CCI may predict future clinical decline or which version may be most sensitive to dementia risk. We investigated the capacity of the CCI-20, CCI-12, and an expanded version of the CCI (CCI-40), to predict progression of clinical dementia status in a demographically diverse sample. Einstein Aging Study participants (community-dwelling cohort; n = 324; M age = 70.4; M education = 15; 67% female; 46.3% White) completed the CCI-40 (self-report) and Clinical Dementia Rating Scale (CDR) at baseline and over annual follow-up (M wave = 1.48). Inclusion criteria were > age 70, English speaking, and nondemented. We investigated the CCI-12, the CCI-20, and the CCI-40 (memory, language, executive functioning, attention, visuospatial, calculation, and orientation domains). We used generalized LME to examine how CCI at baseline impacts rate change of CDR status, with CCI, time and their interaction term as independent variables, adjusting for covariates. All CCI total scores were significantly associated with the rate change in log odds on CDR (CCI-40, β= 0.013, p = 0.001; CCI-20, β= 0.020, p = 0.002; CCI-12, β= 0.013, p = 0.002). Regardless of version, the CCI performance at baseline predicts future progression in clinical dementia status. Using the CCI to assess self-perceived cognition may enhance risk detection in clinical and research settings. Future research will replicate these findings across a range of predementia diagnoses.

Mechanism of action of sprG1-encoded type I toxins in Staphylococcus aureus: from membrane alterations to mesosome-like structures formation and bacterial lysis.

sprG1/SprF1 is a type I toxin-antitoxin system located on Staphylococcus aureus prophage. It has previously been shown that the two toxins, SprG131 and SprG144, encoded by the sprG1 gene, are two membrane-associated peptides structured in a single α-helix. Overexpression of these two peptides leads to growth inhibition and even S. aureus death. In this study, we investigated the involvement of each peptide in this toxicity, the sequence requirements necessary for SprG131 toxicity, and the mechanism of action of these two peptides. Our findings show that both peptides, when expressed individually, are able to stop growth, with higher toxicity observed for SprG131. The combination of a hydrophobic domain and a charged domain located only at the C-terminus is necessary for this toxicity, likely to retain the orientation of the transmembrane domain. A net cationic charge for SprG131 is not essential to induce a growth defect in S. aureus. Furthermore, we established a chronology of toxic events following overexpression to gain insights into the mode of action of SprG144 and SprG131. We demonstrated that mesosome-like structures are already formed when membrane is depolarized, about 20 min after peptides induction. This membrane depolarization occurs concomitantly with a depletion of intracellular ATP, leading to S. aureus growth arrest. Moreover, we hypothesized that SprG144 and SprG131 do not form large pores in the S. aureus membrane, as ATP is not excreted into the extracellular medium, and membrane permeabilization is delayed relative to membrane depolarization. The next challenge is to identify the conditions under which SprG144 and SprG131 are naturally expressed, and to uncover their potential roles during staphylococcal growth, colonization, and infection.

Wetting Behavior of A-block-(B-random-C) Copolymers with Equal Block Surface Energies on Surfaces Functionalized with B-random-C Copolymers.

To form nanopatterns with self-assembled block copolymers (BCPs), it is desirable to have through-film domains that are oriented perpendicular to the substrate. The domain orientation is determined by the interfacial interactions of the BCP domains with the substrate and with the free surface. Here, we use thin films of two different sets of BCPs with A-block-(B-random-C) architecture matched with a corresponding B-random-C copolymer nanocoating on the substrate to demonstrate two distinct wetting behaviors. The two sets of A-b-(B-r-C) BCPs are made by using thiol-epoxy click chemistry to functionalize polystyrene-block-poly(glycidyl methacrylate) with trifluoroethanethiol (TFET) and either 2-mercaptopyridine (2MP) or methyl thioglycolate (MTG). For each set of BCPs, the composition ratio of the two thiols in the BCP (φ1) is found that results in the two blocks of the modified BCP having equal surface energies (Δγair = 0). The corresponding B-r-C random copolymers were synthesized and used to modify the substrate, and the composition ratio (φ2) values that resulted in the two blocks of the BCP having equal interfacial energy with the substrate (Δγsub = 0) were determined with scanning electron microscopy. The correlation between each block's γsub value and the interaction parameter, χ, is employed to explain the different wetting behaviors of the two sets of BCPs. For the thiol pair 2MP and TFET, the values of φ1 and φ2 that lead to Δγair = 0 and Δγsub = 0, respectively, are significantly different. A similar difference was observed between the φ1 and φ2 values that lead to Δγair = 0 and Δγsub = 0 for the BCPs made with the thiol pair MTG and TFET. In the latter case, for Δγsub = 0 two windows of φ2 are identified, which can be explained by the thermodynamic interactions of the specific thiol pair and the A-b-(B-r-C) architecture.

Temperature Effect on Fatigue Behavior of BCZT Ceramics and Defects Analysis by Synchrotron X-Ray Absorption Spectroscopy

This paper presents the effect of temperature on the electrical fatigue behavior of barium calcium zirconate titanate (Ba0.85Ca0.15Zr0.1Ti0.9O3) ceramics. Fatigue degradation and its practical applications are a significant problem in piezo/ferroelectric ceramics. Fatigue-induced domain orientations, physical damage or microcracking, and defects were studied using, X-ray diffraction (XRD), synchrotron X-ray absorption spectroscopy (XAS), and scanning electron microscope (SEM) techniques. The remnant polarization (Pr) decreased with the number of fatigue cycles, and the rate at which the decrease occurred was different for different fatigue temperatures. The weak and strong domain wall pinning effects played a major role in the Pr value with respect to the fatigue cycles. The sharp rise of Ec value at 5 × 103 cycles and the abrupt decrease of Ec values after 5 × 104 cycles could be due to the field screening effect and heat recovery of pinned domains. The abrupt decrease of Pr values after 5 × 105 cycles could be due to physical damage near the electrode interface region, and the same physical damage decreased with the increase in fatigue temperature. The near-edge X-ray absorption fine structure (NEXAFS) study was utilized to evaluate the oxygen-related defect concentration.

Effect of Underlayer Quality on Microstructure, Stoichiometry, and Magnetic Properties of Hexaferrite BaFe12O19 Grown on YSZ(111) by Pulsed Laser Deposition.

We have studied the effect of platinum underlayer for two deposited thicknesses on the microstructure, crystalline quality, morphology, chemical composition, and magnetic properties as well as magnetic domain formation of BaFe12O19 (BaM) grown on YSZ(111) by pulsed laser deposition (PLD). We found that PLD platinum deposited with a thickness of 25 nm cannot withstand the dewetting phenomenon occurring during the subsequent BaM layer growth. A smooth and continuous Pt underlayer that possesses a sharp interface and omits the intermixing between the BaM and substrate was successfully achieved for a deposited Pt film thickness of 75 nm. Independent of the thickness of the deposited Pt layer, the c-axis orientation as well as coercivity Hc and the anisotropy HA fields were significantly improved due to a remarkable improvement of lattice mismatch in comparison with the BaM layer grown without a Pt underlayer on YSZ(111). By applying high-resolution X-ray diffraction, scanning and transmission electron microscopy (SEM/TEM), and atomically resolved scanning TEM imaging combined with energy-dispersive X-ray spectroscopy, as well as atomic and magnetic force microscopy, a comprehensive investigation of both structure and chemical composition of the deposited BaM films and their interfacial regions was performed. This study aimed to correlate the enhancement of the overall magnetic properties and of the local spin magnetic domain orientation with the modification of BaM microstructure and chemical composition at the nanometer scale due to the Pt underlayer. Finally, we attempted to understand the mechanisms that control the magnetic properties of these BaM films in order to be able to tailor them.

Gain-loss domain and social value orientation as determinants of risk allocation decisions

People often make less risky decisions for themselves than others. We examined how people allocated risks (i.e., determining the ratio of uncertain outcomes to certain outcomes) between themselves and others. We also investigated gain (vs. loss) domain and social value orientation as predictors of risk allocations. The results of three experiments demonstrated that participants were more likely to share their risks equally between themselves and others than distribute risk unequally. In the gain (vs. loss) domain, participants allocated fewer risks to themselves and more risks to the other person for unequal risk allocations. Compared to proselfs, prosocials were more likely to allocate risks equally. We also found stronger domain effects on unequal risk allocations for proselfs than for prosocials. Therefore, our findings clarify the effects of risk distribution, domain, and social value orientation on interpersonal allocation decisions and highlight equal risk distribution between oneself and others.

Association between cognitive function and probability of prodromal Parkinson's disease in middle aged and elderly people aged 55 years and above in 4 provinces in China

Objective: To analyze probability of prodromal Parkinson's disease (pPD) and assess the association between global cognitive function and cognitive domain function and probability of pPD in ≥55 years old middle-aged and elderly people in Hebei, Zhejiang, Shaanxi and Hunan Provinces in China. Methods: Data were collected from dataset of the Community-based Cohort Study on Nervous System Disease 2020. We selected 4 634 Alzheimer disease and Parkinson's disease free persons aged ≥55 years with completed information on demographics, disease history, cognitive test, and risk factors of Parkinson's disease for this study. Cognitive function was assessed using Montreal Cognitive Assessment Scale (Chinese version). Calculation of probability of pPD and assessment of possible/probable pPD were performed according to the criteria published by the International Parkinson and Movement Disorder Society. Multivariate linear regression model was used to analyze the association between cognitive function and probability of pPD. Results: The M (Q1,Q3) of global cognitive function and cognitive domains in terms of memory, execution, visuospatial function, language, attention and orientation were 25 (20, 30), 13 (11, 15), 10 (7, 12), 6 (4, 7), 5 (4, 6), 15 (12, 18) and 6 (6, 6) points, respectively. The M(Q1,Q3) of probability of pPD was 0.42% (0.80%, 1.73%), and the proportion of the study subjects with possible/probable pPD was 0.4%. Differences in the distribution of probability of pPD were significant among groups by total cognitive score quartiles (P<0.001), and the difference in proportions of study subjects with possible/probable pPD was significant and showed decline trend (P=0.001). After adjusted for confounders, the results of multivariate linear regression analyses showed that probability of pPD in the Q2, Q3 and Q4 group decreased by 23.4%, 31.2% and 20.1% compared with Q1 group, and corresponding β values were 0.766 (95%CI: 0.702-0.836), 0.688 (95%CI: 0.631-0.751) and 0.799 (95%CI: 0.730-0.875), respectively, the trend was significant (P<0.001). Higher index scores of execution, visuospatial function, language, attention and orientation were highly related to lower probability of pPD (P<0.001). Conclusion: Declines in global cognitive function and cognitive domains of execution, visuospatial function, language, attention and orientation might increase the probability of pPD in middle-aged and elderly people, suggesting the importance of cognitive intervention in early stage for pPD prevention.

Controlled Synthesis and Accurate Doping of Wafer-Scale Two-Dimensional Semiconducting Transition Metal Dichalcogenides.

Two-dimensional (2D) semiconducting transition metal dichalcogenide (TMDCs) possess atomically thin thickness, dangling-bond free surface, flexible band structure, and silicon-compatible feature, making them one of the most promising channels for constructing state-of-the-art field-effect transistors in the post-Moore's era. However, the existing 2D semiconducting TMDCs fall short of meeting the industry criteria for practical applications in electronics due to their small domain size and the lack of effective approach to modulate intrinsic physical properties. Therefore, it is crucial to prepare and doping of 2D semiconducting TMDCs single crystals with wafer size. In this review, wesystematically summary the up-to-date progresses regarding the wafer-scale growth of 2D semiconducting TMDCs polycrystalline and single-crystal films. The domain orientation control of 2D TMDCs and the seamless stitching of unidirectionally aligned 2D islands by means of substrate design are proposed. In addition, the accurate and uniform doping of 2D semiconducting TMDCs and the effect on electronic device performances are also discussed. Finally, the dominating challenges pertaining to enhance electronic device performances of TMDCs are emphasized, and the further development directions are put forward. This review provides a systematically and in-depth summary for high-performance device applications of 2D semiconducting TMDCs. This article is protected by copyright. All rights reserved.

Relationship between the tensile modulus and the thermal conductivity perpendicular and in the fiber direction of PAN-based carbon fibers

A thorough knowledge and understanding of the structure–property relationship between thermal conductivity and C-fiber morphology is important to estimate the behavior of carbon fiber components, especially under thermal loading. In this paper, the thermal conductivities of different carbon fibers with varying tensile modulus were analyzed perpendicular and parallel to the fiber direction. Besides the measurement of carbon fiber reinforced polymers, we also measured the thermal conductivity of single carbon fibers directly. The measurements clearly proved that the thermal conductivity increased with the tensile modulus both in fiber and perpendicular direction. The increase is most pronounced in fiber direction. We ascribed the increase in tensile modules and thermal conductivity to increasing anisotropy resulting from the orientation of graphitic domains and microvoids.Graphical abstract

Direct Polyphenol Attachment on the Surfaces of Magnetite Nanoparticles, Using Vitis vinifera, Vaccinium corymbosum, or Punica granatum.

This study presents an alternative approach to directly synthesizing magnetite nanoparticles (MNPs) in the presence of Vitis vinifera, Vaccinium corymbosum, and Punica granatum derived from natural sources (grapes, blueberries, and pomegranates, respectively). A modified co-precipitation method that combines phytochemical techniques was developed to produce semispherical MNPs that range in size from 7.7 to 8.8 nm and are coated with a ~1.5 nm thick layer of polyphenols. The observed structure, composition, and surface properties of the MNPs@polyphenols demonstrated the dual functionality of the phenolic groups as both reducing agents and capping molecules that are bonding with Fe ions on the surfaces of the MNPs via -OH groups. Magnetic force microscopy images revealed the uniaxial orientation of single magnetic domains (SMDs) associated with the inverse spinel structure of the magnetite (Fe3O4). The samples' inductive heating (H0 = 28.9 kA/m, f = 764 kHz), measured via the specific loss power (SLP) of the samples, yielded values of up to 187.2 W/g and showed the influence of the average particle size. A cell viability assessment was conducted via the MTT and NRu tests to estimate the metabolic and lysosomal activities of the MNPs@polyphenols in K562 (chronic myelogenous leukemia, ATCC) cells.

Boundary-Directed Epitaxy of Block Copolymers Toward Sub-10 nm Fabrication

The directed self-assembly (DSA) of block copolymers (BCPs) can be used to produce nanometer-scale patterns without the cost and process complexity of state-of-the-art optical nanolithography. Thus, DSA is of potential use in a wide variety of semiconductor technologies, such as finFETs and biosensors. To control the position and orientation of BCP domains and create technologically useful patterns, conventional DSA mechanisms often rely on topographically complex structures or high-resolution chemical patterns that are difficult to fabricate. In comparison, a newly discovered mechanism for the DSA of BCPs – termed “boundary-directed epitaxy” – utilizes the chemical contrast at the boundaries between a substrate and relatively wide chemical stripe.[1] As a result, aligned and high density-multiplied BCP nanopatterns with half-pitch of 6.4 nm have been created using stripes as wide as 100 nm. By obviating the need for high-resolution chemical patterns, boundary-directed epitaxy offers exciting opportunities for the fabrication of sub-10 nm nanostructures.[1] Boundary-directed epitaxy of block copolymers. R.M. Jacobberger, V. Thapar, G.-P. Wu, T.-H. Chang, V. Saraswat, A.J. Way, K.R. Jinkins, Z. Ma, P.F. Nealey, S.-M. Hur, S. Xiong, M.S. Arnold, Nature Communications 11, 4151 (2020), 10.1038/s41467-020-17938-3. Figure 1