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3D melt electrowritten MXene-reinforced scaffolds for tissue engineering applications
Get PDF2D Ti3C2Tx (MXene) is attracting significant attention in tissue engineering. The incorporation of these promising materials into conventional scaffolds remains challenging, particularly with physicochemical properties compatible with biological systems. Melt electrowriting (MEW) has emerged as a powerful additive manufacturing technique for biofabrication of customized three-dimensional (3D) scaffolds composed of bioactive materials. This study introduces MEW of 2D MXene and polycaprolactone (PCL) nanocomposite scaffolds for tissue engineering applications. First, Ti3C2Tx was functionalized using (3-aminopropyl) triethoxysilane (referred to as f-MXene) to obtain a blended nanocomposite in PCL matrix (referred to as MX/PCL). Fourier transform infrared spectroscopy revealed the nanocomposite composition. X-ray diffraction analysis showed the reduced crystallinity in PCL after incorporation of f-MXene. Differential scanning calorimetry helped to establish the optimal MEW parameters. Thermogravimetric analysis conducted on nanocomposites containing 0.1, 0.5, and 1% (w/w) f-MXene showed the thermal stability of MXene during the MEW process. The extrudability and printability of the nanocomposites with varying concentrations was demonstrated using MEW in 0-90-degree mesh scaffolds with fine filament dimensions. Scanning electron microscopy and Energy-dispersive x-ray spectroscopy mapping showed the shape fidelity, printing accuracy, and structural integrity of 3D MEW scaffolds with uniform distribution of f-MXene, respectively. Further characterization showed the concentration-dependent enhancement in hydrophilicity and compressive modulus and yield strength of scaffolds upon integration of f-MXene. Atomic force microscopy analysis demonstrated that the topography of the 3D MEW MX/PCL scaffolds changed compared to the pristine PCL and the roughness of the surfaces increased as the concentration of the f-MXene increased. Accelerated degradation tests demonstrated that increasing filler concentration in the reinforced scaffolds progressively delayed degradation compared to the control. The in vitro characterization showed the adherence of MC3T3-E1 preosteoblast cells on MX/PCL scaffolds and their enhanced osteogenic differentiation. The findings indicate that 3D printed MX/PCL nanocomposite scaffolds have significant potential as mechanically robust scaffolds with controlled degradation rate and cytocompatibility for tissue regeneration, with properties tunable for specific applications
Rankings of curved and sharp-angled drawings: frames and evaluation criteria
No full textThis research investigates how rankings of curved versus sharp-angled line drawings are influenced by surrounding frames and evaluation criteria. We predicted that congruence among the curvature of a drawing, the curvature of its frame, and the evaluation criterion might increase participants’ rankings of that stimulus. Participants ranked 26 sets of six stimuli (curved and sharp-angled versions of line drawings, presented unframed, within square frames, or within round frames) according to their curvature (Study 1), or their pleasantness and interestingness (Study 2). Framed stimuli were ranked as more pleasant, and more interesting, than unframed stimuli. Beyond this, rankings seemed to be somewhat sensitive to congruencies among the curvature of the drawing, the curvature
of its frame, and the evaluation criterion. These effects also differed between different types of drawing. For contained drawings, which did not reach the boundaries of their frame area, curved stimuli tended to be ranked as more pleasant than sharp-angled stimuli, except when they were presented in a sharp-angled, and therefore incongruent, square frame. For truncated drawings, which did touch the boundaries of their frame area, sharp-angled stimuli were ranked as more pleasant than curved stimuli, except when they were presented in an incongruent round frame; sharp-angled stimuli were also ranked as more interesting than curved stimuli, and this did not seem to be moderated by framing. Overall, judgments were influenced by stimulus- and task-related factors, and by congruence among those factors
Capacity planning under local differential privacy with optimized budget selection
No full textWith the growing popularity of local differential privacy (LDP), there is increasing interest in its deployment in industrial applications, smart homes, and smart cities. However, the main premise of LDP is that data are perturbed to protect privacy, and therefore consumption statistics estimated via LDP are inherently noisy. When noisy estimates are used for capacity planning, they can lead to false positives (false claims of capacity exceedance) or false negatives (actual exceedances are neglected). To address these concerns, this article proposes a system called CAPRI for capacity planning and optimized budget selection in smart city applications under LDP. Based on a specified set of conditions (e.g., number of clients, possible consumption values, LDP protocol) and constraints (e.g., false positive probability should be below 0.01), CAPRI is able to determine the ɛ privacy budget, which simultaneously satisfies the desired constraints and maximizes clients' privacy. To do so, CAPRI proposes an optimization-based problem formulation and a search-based solution, which relies on LDP simulations. We experimentally validate and demonstrate the effectiveness of CAPRI using real-world and synthetic datasets, three popular LDP protocols, and various constraints and conditions
Engineering interfacial thermal transport through comparative analysis of electrospraying and dip coating of silanized h-BN for thermo-mechanical enhancement of CF/Epoxy composites
No full textThe inherently low thermal conductivity of carbon fiber (CF) reinforced epoxy composites is mainly due to porosity and fabrication defects that interrupt thermal pathways. This study demonstrated a pathway to control heat in both out-of-plane and in-plane directions by incorporating hexagonal boron nitride (h-BN) as a thermally conductive agent and by configuring interface interactions on the CF and within the epoxy resin while evaluating physical and chemical interactions. Two integration techniques of dip coating and electrospraying were employed to apply h-BN, effectively creating robust h-BN layers on CF and dispersing neat or silane-modified h-BN within the epoxy matrix by combining vacuum bag and hot compression processes to reduce void content. Electrospraying silane-modified h-BN onto carbon fiber, together with incorporating 20 wt% silane-modified h-BN into the matrix, resulting in a total loading of 11 wt% in the composite-led to the highest out-of-plane thermal conductivity of 1.3 W/mK, representing a 166 % increase compared to CF reinforced into epoxy composite (CF+/EP) with the out-of-plane thermal conductivity of 0.49 W/mK. Mechanically, the configuration using neat h-BN in both the matrix and dip-coated CF achieved a 127 % increase in flexural modulus and a 49 % improvement in Charpy impact strength versus unfilled CF/epoxy composites. Resizing the CF improved directional thermal conductivity in CF/epoxy composites by controlling porosity, achieving approximately an 81 % reduction in porosity when using silanized h-BN
Cas9 beyond CRISPR – SUMOylation, effector-like potential and pathogenic adaptation
Get PDFThe CRISPR/Cas9 system has revolutionized molecular biology and gene editing, yet key aspects of its regulation, especially within eukaryotic environments, remain enigmatic. In this Viewpoint article, I will speculate on and explore the provocative hypothesis that Cas9 may possess previously unrecognized effector-like functions when expressed in host cells, potentially shaped by host-mediated post-translational modifications (PTMs). Of particular interest is SUMOylation at lysine 848, a key residue for DNA binding within the catalytic site, raising the possibility that this modification is not incidental, but functionally significant and precisely regulated. SUMOylation, a eukaryotic PTM, is increasingly recognized as a mechanism that also targets bacterial and viral effector proteins and virulence factors during infection, exerting context-dependent effects that may either enhance or hinder pathogen replication. Could Cas9, beyond its canonical role in bacterial CRISPR immunity, act as a host-modulating effector during infection, akin to known bacterial nucleomodulins such as transcription activator-like (TAL) effectors? If so, this would imply that certain pathogenic bacteria may have evolved Cas9 variants capable of exploiting host PTM machinery and targeting the host genome—an adaptation with potential implications for microbial virulence, host–pathogen interactions, and co-evolutionary dynamics. This perspective underscores the importance of systematically mapping Cas9 PTMs and examining their evolutionary conservation, functional significance, and pharmacological tunability, not only for basic biological insight and to deepen our understanding of microbial strategies, but also to refine the precision and safety of Cas9-based therapeutic platforms
Text-as-data in international relations: current debates over text analysis in international relations studies
Get PDFThis review explores recent advancements in the study of international relations by focusing on text as a data source. Once a primary resource, texts have regained prominence with the rise of computational tools, offering new analysis opportunities. This review highlights the importance of communication, newspapers, speeches, and even social media in understanding human behavior and interactions among states. These textual sources not only provide insights into leaders’ reputation, resolve, and psychological traits but also contribute to detecting policy agendas and studying diplomatic outcomes. Improvements in methods such as big data analysis and machine learning have transformed how scholars build and analyze observational data in international relations. By revisiting key developments and applications, this review provides an overview of how texts are being used across various fields, including gathering event data, understanding foreign-policy agendas, particularly in international organizations, and detecting leader signals through platforms like Twitter. This assessment also addresses the growing significance of integrating these novel methods into future research and highlights the potential of text-based studies to shape the future of the discipline, offering scholars improved tools for analyzing complex global interactions and uncovering patterns in international relations
The subjection of the sciences to the attention of even English professors: Kuhn's influence on literary theory
No full textFrequency domain image augmentation for domain generalized image classification
No full textDomain generalization (DG) remains a major challenge in computer vision, in which models trained on source domain(s) perform poorly on unseen target domains. One way to address this issue is by using augmentation techniques to generate synthetic images from the original ones, aiming to make them more similar to the target domain images. To improve this technique, a new augmentation method called Amplitude-Phase Augmentation (APA) was investigated. The aim of this method is to increase the robustness of models by exposing them to a greater level of input variations. APA relies on the product of amplitudes in the frequency domain. By applying a specific form of amplitude multiplication, it generates cross-domain augmented images with a wider range of transformations in the frequency space. Experimental results showed that APA leads to superior performance compared to competitive counterparts
Correlation of burst behavior with magnetar age
Get PDFWe analyze a wide set of historical magnetar burst observations detected with five different instruments, calibrating these to the energy range of Fermi-GBM observations for consistency. We find a striking correlation between a magnetar’s characteristic age and both its typical burst energy and its burst activity level. Arguing that this bursting behavior also correlates with true age, we interpret it as the result of a reducing high-stress volume of the crust in an aging magnetar: Previous giant flares cause relaxation of large regions of its crust and inhibit burst clustering, while the reducing burst energy reflects the progressively shallower region of the crust where Hall drift can build stresses effectively, as the field decays through the range ∼1012-1013 G. Low-energy bursts from very young magnetars may represent failures of weak regions of the crust that have only recently solidified
QoS aware video analysis over low-cost edge-cluster: a utility minimization approach
No full textThe constrained availability of resources on an edge analytics platform prompted the need for a trade-off between accuracy and latency by selecting suitable deep neural network (DNN) models on-the-fly. Earlier efforts either used a single powerful multi-core edge computing device or a distributed cluster of edge nodes. While the former has a high cost and power consumption, the latter incur a high communication overhead. In this paper, we propose a quality-of-service (QoS) aware video analytics platform using an edge-cluster made of low-cost devices. The edge nodes, that constitute the cluster, host heterogeneous DNN models having different configurations and number of layers. The nodes cooperate among themselves to jointly process a streaming video to achieve an optimal QoS. We formulate an optimization problem using penalty as the utility function to minimize the long-term average penalty (LTAP). We first design a DNN model recommender algorithm to minimize the LTAP and then compare it with an Oracle to show that it can achieve an LTAP with an error of 1.6% and 9.88% for video resolutions of 720p and 2160p, respectively. We also show that the bounds on LTAP are lower and tighter for lower resolution videos compared to the higher resolution videos