3D Arrangement Research Articles

Atomic Structure and 3D Shape of a Multibranched Plasmonic Nanostar from a Single Spatially Resolved Electron Diffraction Map.

Despite the interest in improving the sensitivity of optical sensors using plasmonic nanoparticles (NPs) (rods, wires, and stars), the full structural characterization of complex shape nanostructures is challenging. Here, we derive from a single scanning transmission electron microscope diffraction map (4D-STEM) a detailed determination of both the 3D shape and atomic arrangement of an individual 6-branched AuAg nanostar (NS) with high-aspect-ratio legs. The NS core displays an icosahedral structure, and legs are decahedral rods attached along the 5-fold axes at the core apexes. The NS legs show an anomalous anisotropic spatial distribution (all close to a plane) due to an interplay between the icosahedral symmetry and the unzipping of the surfactant layer on the core. The results significantly improve our understanding of the star growth mechanism. This low dose diffraction mapping is promising for the atomic structure study of individual multidomain, multibranched, or multiphase NPs, even when constituted of beam-sensitive materials.

Induced Pluripotent Stem Cell-Derived Parathyroid Organoids Resemble Parathyroid Morphology and Function.

The primary role of the parathyroid glands is to maintain calcium homeostasis through the secretion of parathyroid hormone (PTH). The limited proliferative capacity and differentiation of parathyroid cells hinder the generation of cell therapy options. In this study, parathyroid organoids are successfully generated from human-induced pluripotent stem cells (hiPSCs). At the end of the 20 days of differentiation, the parathyroid organoids exhibited distinct parathyroid morphology. Stereomicroscope, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analysis demonstrated the 3D arrangement of the cell layers in which intracellular structures of parathyroid cells resemble human parathyroid cellular morphology. Comprehensive molecular analyses, including RNA sequencing (RNA-Seq) and liquid chromatography/mass spectrometry (LC-MS/MS), confirmed the expression of key parathyroid-related markers. Protein expression of CasR, CxCr4, Gcm2, and PTH are observed in parathyroid organoids. Parathyroid organoids secrete PTH, demonstrate active intercellular calcium signaling, and induce osteogenic differentiation via their secretome. The tissue integration potential of parathyroid organoids is determined by transplantation into parathyroidectomized rats. The organoid transplanted animals showed significant elevations in PTH-related markers (CasR, CxCr4, Foxn1, Gcm2, and PTH). PTH secretion is detected in organoid-transplanted animals. The findings represent a significant advancement in parathyroid organoid culture and may offer a cellular therapy for treating PTH-related diseases, including hypoparathyroidism.

Assemblable 3D biomimetic microenvironment for hMSC osteogenic differentiation

Abstract The suitable simulation of a tissue’s native environment is one of the elemental premises of tissue engineering. Although various attempts have been made to induce human mesenchymal stem cells (hMSC) into an osteogenic pathway, they are still far from widespread clinical application. Most strategies mainly focus on providing a specific type of cue, far from replicating the complexity of the bone microenvironment. By applying magnetoelectric microspheres composed of poly(vinylidene fluoride) (PVDF) and cobalt ferrites, functionalized with collagen and gelatin, and packed in a 3D arrangement, a multifunctional platform for hMSC osteogenic differentiation has been developed. This platform is able to perform mechanical stimulation of piezoelectric PVDF, mimicking the bones biophysical electromechanical cues. Surface functionalization with extracellular matrix (ECM) biomolecules and osteogenic media further contribute to this all-round approach. hMSC were cultured in osteogenic-inducing conditions in order to induce them into this pathway and tested for proliferation, surface biomarkers, and gene expression to evaluate their osteogenic commitment.

Ultradense Array of On-Chip Sensors for High-Throughput Electrochemical Analyses.

High-throughput sensors are valuable tools for enabling massive, fast, and accurate diagnostics. To yield this type of electrochemical device in a simple and low-cost way, high-density arrays of vertical gold thin-film microelectrode-based sensors are demonstrated, leading to the rapid and serial interrogation of dozens of samples (10 μL droplets). Based on 16 working ultramicroelectrodes (UMEs) and 3 quasi-reference electrodes (QREs), a total of 48 sensors were engineered in a 3D crossbar arrangement that devised a low number of conductive lines. By exploiting this design, a compact chip (75 × 35 mm) can enable performing 16 sequential analyses without intersensor interferences by dropping one sample per UME finger. In practice, the electrical connection to the sensors was achieved by simply switching the contact among WE adjacent fingers. Importantly, a short analysis time was ensured by interrogating the UMEs with chronoamperometry or square wave voltammetry using a low-cost and hand-held one-channel potentiostat. As a proof of concept, the detection of Staphylococcus aureus in 15 samples was performed within 14 min (20 min incubation and 225 s reading). Additionally, the implementation of peptide-tethered immunosensors in these chips allowed the screening of COVID-19 from patient serum samples with 100% accuracy. Our experiments also revealed that dispensing additional droplets on the array (in certain patterns) results in the overestimation of the faradaic current signals, a phenomenon referred to as crosstalk. To address this interference, a set of analyses was conducted to design a corrective strategy that boosted the testing capacity by allowing using all on-chip sensors to address subsequent analyses (i.e., 48 samples simultaneously dispensed on the chip). This strategy only required grounding the unused rows of QRE and can be broadly adopted to develop high-throughput UME-based sensors. In practice, we could analyze 48 droplets (with [Fe(CN)6]4-) within ∼8 min using amperometry.

Non-Destructive Analysis of Pb-Acid Battery Positive Plates, Based on Neutron Tomography

Lead-acid batteries (LABs) are one of the first rechargeable batteries. Historically used for backup power during the early public electricity network, LABs now hold a global market share of approximately 50%, mainly in automotive applications and energy reserves for telecommunication and data networks. Their low energy density and high surge current make them suitable for high-current, in-time applications. The LAB electrochemical cell consists of PbO2 as the positive electrode, metallic Pb as the negative electrode, and H2SO4 as the electrolyte.The composition of the positive electrode active material (PAM) involves mixtures of α- and β-PbO2 and an amorphous gel phase of Pb(IV) oxy-hydroxides, determining the PAM's functional properties. The hydrated Pb(IV) oxy-hydroxide is the electrochemically active phase, conducting ions but not electrons. The mechanical consistency of the PAM relies on α-PbO2, acting as a structural binder, while β-PbO2 provides electronic conductivity. LAB performance is influenced by the proportions of α and β crystalline zones. Jointly, α - and β -PbO2 act as a Pb(IV) reservoir for reduction, occurring through the gel phase during discharge. Together, α- and β-PbO2 function as a reservoir for Pb(IV) reduction, a process that takes place through the gel phase during discharge in lead-acid batteries (LABs). These two crystalline phases, α- and β-PbO2, reform from the gel phase during charging, and their proportions depend on the specifics of the charging process and the material state. Consequently, the relative amounts and distribution of α and β crystalline zones play a crucial role in influencing the overall performance of LABs.In the present investigation, we propose, for the first time, an ex situ NT investigation of intact PPs, endeavouring to assess the internal structure of the PAM (pore formation) and spine/PAM decohesion of real battery electrodes – fabricated with two alternative metallurgical methods (punching P and gravity casting G) – subjected to harsh electrochemical testing conditions, representative of recharge abuse. Our study is complemented by X-ray radiography - aimed at pinpointing spine and PAM cracking – and cross-sectional SEM imaging aimed at disclosing details with spine/PAM interface: grid shape variation, corrosion depth, mode and mechanism, corrosion layer nature and thickness.The synergic effect of these measurments enable a complete understanding and tracking of the PPs degradation mechanism : (i) NT offered a 3D quantitative and qualitative assessment of PAM porosity ,spine/PAM decohesions, and highly attenuating regions. Aging led to pore growth, with G electrodes displaying more extensive cracking. Variations in porosity distribution between P and G electrodes is observed. Hydrogenated gel distribution differed between electrode types and with aging. (ii) XR provided a non-destructive grid-scale overview. P electrodes exhibited limited defects, while G electrodes showed extensive spine issues. Corrosion progression differed from local SEM observations (iii) in which corrosion is explored at the spine/PAM interface, revealing no clear correlation between current density and corrosion. Representative micrographs for P and G electrodes were shared.The combination of these technique enable a complete characterization of positive plate degradation,.The methodical use of NT holds the potential to establish a comprehensive morpho chemical knowledge base for comprehending the manufacturing and aging processes of lead-acid battery electrodes directly visualization of the 3D arrangement of the hydrogen-containing electroactive amorphous phase, is a crucial metric for assessing the state of health (SOH) that is typically challenging to access experimentally This approach, coupled with in operando capabilities, relies on the quantitative examination of functionally significant features and their changes throughout the aging process. Figure 1

Orientation and shape distributions effective medium theory (OSDEMT): Applications in plasmonic nanocomposites

Plasmonic anisotropic nanocomposites containing in particular nanorods and nanowires are gaining increasing interest due to their remarkable physical and optical properties. In this paper, we introduce a novel effective medium theory which we call “Orientation and Shape Distributions Effective Medium Theory” (OSDEMT), to describe the optical properties of a 3D arrangement of metallic nanorods in a dielectric matrix. The effective dielectric properties of plasmonic nanocomposites containing nanorods with different shape and orientation configurations were simulated and analyzed using OSDEMT. We demonstrate that the amplitudes of the longitudinal and transverse surface plasmonic resonances depend on the orientation distribution of the nanostructures, when their positions remain unchanged. Moreover, we show that the anisotropic properties of the nanocomposites are very sensitive to the aspect ratios of the nanorods so that even spherical-centered shape distributions exhibit anisotropic properties when oriented. Finally, we confront the OSDEMT to UV–visible extinction measurements conducted on gold nanorods in a toluene suspension.

Targeting tumor-associated macrophages with mannosylated nanotherapeutics delivering TLR7/8 agonist enhances cancer immunotherapy

Tumor-associated macrophages (TAMs) constitute 50–80% of stromal cells in most solid tumors with high mortality and poor prognosis. Tumor-infiltrating dendritic cells (TIDCs) and TAMs are key components mediating immune responses within the tumor microenvironment (TME). Considering their refractory properties, simultaneous remodeling of TAMs and TIDCs is a potential strategy of boosting tumor immunity and restoring immunosurveillance. In this study, mannose-decorated poly(lactic-co-glycolic acid) nanoparticles loading with R848 (Man-pD-PLGA-NP@R848) were prepared to dually target TAMs and TIDCs for efficient tumor immunotherapy. The three-dimensional (3D) cell culture model can simulate tumor growth as influenced by the TME and its 3D structural arrangement. Consequently, cancer spheroids enriched with tumor-associated macrophages (TAMs) were fabricated to assess the therapeutic effectiveness of Man-pD-PLGA-NP@R848. In the TME, Man-pD-PLGA-NP@R848 targeted both TAMs and TIDCs in a mannose receptor-mediated manner. Subsequently, Man-pD-PLGA-NP@R848 released R848 to activate Toll-like receptors 7 and 8, following dual-reprograming of TIDCs and TAMs. Man-pD-PLGA-NP@R848 could uniquely reprogram TAMs into antitumoral phenotypes, decrease angiogenesis, reprogram the immunosuppressive TME from “cold tumor” into “hot tumor”, with high CD4+ and CD8+ T cell infiltration, and consequently hinder tumor development in B16F10 tumor-bearing mice. Therefore, dual-reprograming of TIDCs and TAMs with the Man-pD-PLGA-NP@R848 is a promising cancer immunotherapy strategy.

Evaluating the pro-survival potential of apoptotic bodies derived from 2D- and 3D- cultured adipose stem cells in ischaemic flaps

In the realm of large-area trauma flap transplantation, averting ischaemic necrosis emerges as a pivotal concern. Several key mechanisms, including the promotion of angiogenesis, the inhibition of oxidative stress, the suppression of cell death, and the mitigation of inflammation, are crucial for enhancing skin flap survival. Apoptotic bodies (ABs), arising from cell apoptosis, have recently emerged as significant contributors to these functions. This study engineered three-dimensional (3D)-ABs using tissue-like mouse adipose-derived stem cells (mADSCs) cultured in a 3D environment to compare their superior biological effects against 2D-ABs in bolstering skin flap survival. The findings reveal that 3D-ABs (85.74 ± 4.51) % outperform 2D-ABs (76.48 ± 5.04) % in enhancing the survival rate of ischaemic skin flaps (60.45 ± 8.95) % (all p < 0.05). Mechanistically, they stimulated angiogenesis, mitigated oxidative stress, suppressed apoptosis, and facilitated the transition of macrophages from M1 to M2 polarization (all p < 0.05). A comparative analysis of microRNA (miRNA) profiles in 3D- and 2D-ABs identified several specific miRNAs (miR-423-5p-up, miR30b-5p-down, etc.) with pertinent roles. In summary, ABs derived from mADSCs cultured in a 3D spheroid-like arrangement exhibit heightened biological activity compared to those from 2D-cultured mADSCs and are more effective in promoting ischaemic skin flap survival. These effects are attributed to their influence on specific miRNAs.

Two-Photon Polymerization 3D-Printing of Micro-scale Neuronal Cell Culture Devices.

Neuronal cultures have been a reference experimental model for several decades. However, 3D cell arrangement, spatial constraints on neurite outgrowth, and realistic synaptic connectivity are missing. The latter limits the study of structure and function in the context of compartmentalization and diminishes the significance of cultures in neuroscience. Approximating ex vivo the structured anatomical arrangement of synaptic connectivity is not trivial, despite being key for the emergence of rhythms, synaptic plasticity, and ultimately, brain pathophysiology. Here, two-photon polymerization (2PP) is employed as a 3D printing technique, enabling the rapid fabrication of polymeric cell culture devices using polydimethyl-siloxane (PDMS) at the micrometer scale. Compared to conventional replica molding techniques based on microphotolitography, 2PP micro-scale printing enables rapid and affordable turnaround of prototypes. This protocol illustrates the design and fabrication of PDMS-based microfluidic devices aimed at culturing modular neuronal networks. As a proof-of-principle, a two-chamber device is presented to physically constrain connectivity. Specifically, an asymmetric axonal outgrowth during ex vivo development is favored and allowed to be directed from one chamber to the other. In order to probe the functional consequences of unidirectional synaptic interactions, commercial microelectrode arrays are chosen to monitor the bioelectrical activity of interconnected neuronal modules. Here, methods to 1) fabricate molds with micrometer precision and 2) perform in vitro multisite extracellular recordings in rat cortical neuronal cultures are illustrated. By decreasing costs and future widespread accessibility of 2PP 3D-printing, this method will become more and more relevant across research labs worldwide. Especially in neurotechnology and high-throughput neural data recording, the ease and rapidity of prototyping simplified in vitro models will improve experimental control and theoretical understanding of in vivo large-scale neural systems.

3D Domain Arrangement in van der Waals Ferroelectric α‐In2Se3

AbstractOne of the exceptional features of the van der Waals (vdW) ferroelectrics is the existence of stable polarization at a level of atomically thin monolayers. This ability to withstand a detrimental effect of the depolarization fields gives rise to complex domain configurations characterized, among others, by the presence of layered “antipolar” head‐to‐head (H‐H) or tail‐to‐tail (T‐T) dipole arrangements. In this study, tomographic piezoresponse force microscopy (TPFM) is employed to study the 3D polarization arrangement in vdW ferroelectric α‐In2Se3. Sequential removal of thin layers from the polar surface using the PFM tip reveals a complex 3D profile of the domain walls in the α‐In2Se3 crystals. Antiparallel domain layers stacked along the polar direction are also observed by PFM imaging of the non‐polar surfaces showing that H‐H and T‐T domain boundaries are commonly present in α‐In2Se3. Application of TPFM to the electrically written domains allows evaluation of their geometrical lateral‐to‐vertical size aspect ratio, which shows a strong prevalence for the sidewise expansion in comparison to the forward growth. Local I–V measurements reveal a strong polarization direction dependence of conductivity due to the modulation of the energy barrier height as corroborated by theoretical modeling.

Rotating coupling of chiral identical twins in multimodal Kresling metamaterials for achieving ultra-high energy absorption

Origami structures have been widely applied for various engineering applications due to their extraordinary mechanical properties. However, the relationship between in-plane rotating coupling and energy absorption of these Origami structures is seldom studied previously. The study proposes a design strategy that utilizes identical-twin rotation (i.e. simultaneous rotation with the same chirality) and fraternal-twin rotation (i.e. simultaneous rotation with the opposite chirality) of Kresling metamaterials to achieve multimodal rotation coupling and enhanced energy absorption. Deformation mode and energy absorption properties of 3D-printed Kresling metamaterials have been studied using both quasi-static compression tests and finite element analysis. Furthermore, effects of polygon units and their connections to 2D and 3D arrangements, which generate 4 × 4 arrays and 2 × 2 × 2 arrays, have been investigated to identify the optimized structures for achieving ultra-high energy absorption of chiral Kresling metamaterials. Results showed that rotating coupling of chiral identical twins in multimodal Kresling metamaterials possesses diverse deformation patterns and ultra-high energy absorption. This study provides a novel strategy to optimize structural designs and mechanical properties of the Kresling metamaterials.

2D to 3D Reconstruction of Boron-Linked Covalent-Organic Frameworks.

The transformation of two-dimensional (2D) covalent-organic frameworks (COFs) into three-dimensions (3D) is synthetically challenging, and it is typically addressed through interlayer cross-linking of alkene or alkyne bonds. Here, we report the first example of the chemical reconstruction of a 2D COF to a 3D COF with a complete lattice rearrangement facilitated by base-triggered boron hybridization. This chemical reconstruction involves the conversion of trigonal boronate ester linkages to tetrahedral anionic spiroborate linkages. This transformation reticulates the coplanar, closely stacked square cobalt(II) phthalocyanine (PcCo) units into a 3D perpendicular arrangement. As a result, the pore size of COFs expands from 2.45 nm for the initial 2D square lattice (sql) to 3.02 nm in the 3D noninterpenetrated network (nbo). Mechanistic studies reveal a base-catalyzed boronate ester protodeboronation pathway for the formation of the spiroborate structure.

Computational Approaches To Design Multi Epitope-Based Vaccine Designing of Dengue virus -2 Enveloped Protein For Dengue Virus

Dengue Fever (DF) is a viral disease transmitted by mosquitoes and is a global concern. A successful vaccine for dengue should induce both neutralizing antibodies and cell-mediated immunity. However, no vaccine currently exists for DF. A multi-epitope vaccine offers a promising strategy for preventing such infections. Objective: To create a dengue virus-2 strain multi-epitope vaccine that is safe, non-allergic, and stimulates a strong immune response. Methods: Leveraging in silico tools, we retrieved and analyzed Dengue virus-2 protein sequences, determining antigenicity using VaxiJen version 2.0 and assessing allergenicity using AllerTop. T-cell epitopes were identified via Immune Epitope Database (IEBD) server for Major Histocompatibility Complex -I (MHC-I) and Major Histocompatibility Complex -II (MHC-II) binding and B-cell epitopes were anticipated through IEBD Linear Epitope Prediction Tool v2.0. Analysis of population coverage estimated the prevalence of MHC alleles interacting with the identified epitopes. A multi-epitope vaccine construct integrated adjuvants, universal linkers, and epitopes, evaluated for physicochemical properties, toxicity, secondary, and tertiary structures. Results: Antigenicity analysis identified highly antigenic Dengue virus-2 protein sequences with low allergenicity. T-cell epitopes revealed multiple epitopes with diverse MHC-I and MHC-II affinity, encompassing conserved regions for potential universal vaccine development. Nine non-toxic, non-allergenic B-cell epitopes were identified. Population coverage analysis demonstrated over 71% prevalence of MHCs binding to identified epitopes across diverse populations. Physicochemical assessments revealed favorable characteristics, including immunogenicity and stability. Tertiary structure prediction illustrated the vaccine's 3D arrangement, validated through Ramachandran plots, exhibiting high-quality protein structure. Conclusions: This multieiptope based vaccine is more immunogenic but further in-vitro and in-vivo study is required for its clinical use

Abstract 3127: Development of three-dimensional cancer cell line spheroid models for the in vitro functional characterization of cytotoxic antibody-drug conjugates

Abstract Background: Antibody-drug conjugates (ADCs) are an effective class of cancer therapeutics which have gained prominence for the treatment of several malignancies. A cytotoxic ADC consists of a linker-payload conjugated to a monoclonal antibody, which targets a distinct tumor-associated antigen (TAA) to enable the delivery of the cytotoxic payload to cancer cells. Presently, there is a need for in vitro models that better recapitulate in vivo tumor tissue complexity to aid in the screening and evaluation of ADCs during preclinical development. Hence, efforts have been made to develop in vitro three-dimensional (3D) models with improved translation to in vivo tumor models compared to traditional two-dimensional (2D) cancer cell line monolayer models. We aimed to generate monoculture cancer cell line spheroids in a high-throughput manner. Subsequently, we sought to evaluate the spheroid penetration capability of structurally distinct ADCs and to assess the 3D cytotoxic activity of a variety of microtubule inhibitor (MTI) and topoisomerase 1 inhibitor (TOPO1i)-bearing ADCs targeting multiple TAAs, comparing to activity in 2D models. Methods: Monoculture cancer cell spheroids were generated by seeding cells from a variety of tumor types, using an automated liquid-handling robot, into microtiter plates treated with ultra-low attachment coating, which allows for scaffold-free self-assembly of cancer cells into a 3D arrangement. Following spheroid formation by incubation for 2-3 days under standard culturing conditions, spheroids were treated with ADCs at a range of concentrations for functional evaluation: the spheroid penetration capability of ADCs of different antibody formats was assessed using high-content confocal imaging of spheroids treated with fluorescently labeled antibodies; the cytotoxic activity of ADCs was characterized using an ATP quantification luminescent reagent, live/dead cell fluorescent stains, and confocal imaging. Results: Monoculture spheroids of varying morphologies were successfully and reproducibly generated with a large panel of &amp;gt;50 cancer cell lines derived from &amp;gt;10 tumor types. Antibodies with different formats demonstrated target-mediated binding and a range of spheroid penetration depths. Additionally, MTI and TOPO1i ADCs evaluated in a panel of cancer cell spheroids demonstrated robust 3D cytotoxicity and differentiated activity when compared to the 2D monolayer assay. In a number of cases, the potency trends across multiple ADCs in 3D cytotoxicity assays were more predictive of in vivo efficacy compared to the 2D assay. Taken together, our high-throughput spheroid assays present important and straightforward in vitro tools to aid in the screening and selection of therapeutic cytotoxic ADC candidates for the treatment of solid tumors. Citation Format: Jodi Wong, Andrea Hernández Rojas, Allysha Bissessur, Lemlem T. Degefie, Araba P. Sagoe-Wagner, Samir Das, Vincent Fung, Kevin Yin, Renee Duan, Sam Lawn, Laurence Madera, Catrina Mi Jung Kim, Alex Wu, Mark E. Petersen, Raffaele Colombo, Jamie R. Rich, Stuart D. Barnscher. Development of three-dimensional cancer cell line spheroid models for the in vitro functional characterization of cytotoxic antibody-drug conjugates [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3127.

Synthesis and structural characterization of poly-thiolactones with varied ring sizes and endocyclic functional groups

The synthesis and isolation of new thiolactone species containing endocyclic ether, polyether, and lactone groups were designed using the reaction between diacyl chlorides with organometallic tin compounds as a template for controlled thioester bond formation. Thus, eight polythiolactones, including cyclo and spiro compounds with different ring sizes and functional groups were prepared, namely 1-oxa-4,9-dithiacycloundecane-5,8-dione (1a), 1-oxa-4,10-dithiacyclododecane-5,9-dione (1b), 1,4-dioxa-7,12-dithiacyclotetradecane-8,11-dione (2a), 1,4-dioxa-7,13-dithiacyclopentaecane-8,12-dione (2b), 2,15,19,32-tetraoxa-6,11,23,28-tetrathia-spiro[16.16]tritriacontane 3,7,10,14,20,24,27,31-octaone (3a), 2,16,20,34-tetraoxa-6,12,24,30-tetrathia-spiro[17.17]pentatriacontan-3,7,11,15,21,25,29,33-octaone (3b), 9,12,25,28-tetraoxa-6,15,22,31-tetratia-1(1,4),17(1,4)-diphenylcyclodotriacontane-5,16,21,32-tetraone (2c), and 2,17,21,36-tetraoxo-6,13,25,32-tetrathia-8(1,4)27(1,4)-diphenyl-spiro[18-18]heptatriacontane-3,7,12,16,22,26,31,35-octaone (3c). The structural characteristics of the eight closely related derivatives were determined by examining the impact of ring size and functional groups, through single-crystal X-ray diffraction techniques. The crystal packing of these polythiolactones was found to be mainly governed by weak C-H···O hydrogen bonding and van der Waals interactions, resulting in partially overlapping tubular arrangements. Hirshfeld analysis was performed to investigate the crystal packing and intermolecular interactions. The results of this study show the possibility of forming 3D tubular arrangements using polythiolactones with various endocyclic groups, including both flexible and rigid spacers.

Echeveria Leaf Morpho-Anatomical Analysis and Its Implications for Environmental Stress Conditions

Echeveria, classified in the Crassulaceae family, possesses unique adaptive strategies with xeromorphic features to withstand semi-arid environments. The diversity and ecological adaptation of succulent plants offer valuable insights into addressing climate change challenges. In particular, the epidermis, hypodermis, vascular bundles arrangement, and stomata characteristics are commonly used to investigate light, humidity, temperature, and water availability adaptations. While leaf anatomical analysis is a common approach, limited studies have been conducted on Echeveria, especially among cultivars. To understand how succulents cope with environmental stress, leaf morpho-anatomical features were analyzed using the free-hand sectioning method with methanol fixation of fifteen Echeveria cultivars. The finding revealed a robust correlation between epidermis and hypodermis size (r = 0.362–0.729), and a positive association between leaf thickness and the epidermis (r = 0.362–0.536), suggesting implications for water storage. Most cultivars displayed a 3D vascular arrangement, with minor vascular bundles surrounding the main vascular bundle at the center, along with small stomata size, and low stomata frequency in the adaxial surface. Moreover, these cultivars grown under controlled conditions maintain their xeromorphic characteristics with the presence of epicuticular wax and thick and fully expanded small leaves. Likewise, the features of cultivars ultimately suggest that these succulents are tolerant to high temperatures and limited water supply. This study provides a fundamental understanding of Echeveria plants’ leaf anatomy and the correlation of their leaf structures toward environmental stress. Likewise, the methods and results of this study will serve as a benchmark for other research in related species.

Acoustic performance of screens designed to act as metamaterials

Metamaterials are, nowadays, a mature field of research in acoustic and many applications with metamaterials have been developed in recent years. In metamaterials, the attenuation of sound is due to the interaction of the sound waves with their geometrically regular structures. The frequency at which the attenuation occurs is calculated with Braggs' law. This work presents sound attenuation measurements of structures made with metamaterials carried out in an anechoic chamber. The arrangements considered are both two- dimensional and three-dimensional: the 2D arrangement was obtained with a regular distribution of linear elements made with bars with diameters of 9, 15, and 20 mm; the 3D arrangement was obtained with a regular distribution of a lattice of spheres with a diameter of 23 mm. The results of the acoustic measurements are reported in terms of insertion loss in the range from 1000 to 10 000 Hz.

From quartz (qtz) to diamond (dia) carbon topologies: Stepwise rationale from crystal chemistry and DFT investigations

From crystal chemistry and density functional theory DFT calculations, a stepwise rationale is proposed for the transformation from standalone distorted tetrahedron α-C5favored over standalone regular tetrahedron β-C5to high density – ultra hard orthorhombic α-C6and β-C6withqtz(quartz-based) topology characterized by 3D arrangements of distorted tetrahedra to lower densitydia-C topology (diamond-like, with regular C4 tetrahedra). Progressive C insertions into orthorhombic α-C5, α-C6, and lastly into C7were operated leading to ultimate C8stoichiometry identified as diamond-like. C7was also used as template to devise C3N4carbonitride with exceptional mechanical properties. The induced structural and physical changes are supported with elastic properties pointing to ultra-hardness, larger forqtzα,β-C6thandiaC8and inferred dynamic stability for all stoichiometries from the phonons band structures. The thermodynamic quantities as the specific heat were compared with diamond experimental CV. The electronic band structures reveal semi-conducting C6, metallic C7characterized by diamond-defect structure, and insulating C8. The results are meant to help further systemic understanding of tetrahedral carbon allotropes.

3D hierarchical microcubic morphological composite and its application for Bi-functional Humidity/Pressure sensing in TENG architecture

Harnessing the power of contact electrification, triboelectric nanogenerators (TENGs) are a cutting-edge energy technology, where output performance is greatly influenced by the micro/nano scale architectures of triboelectric layers. We present a study on the development of TENG by introducing an advanced 3D hierarchical microcubic morphological structure prepared by simple solution casting method, employing a renewable material, lignin, in combination with eco-friendly polyvinyl alcohol (PVA) matrix. The strategic incorporation of epichlorohydrin (EPCH) as a crosslinker enhances thermal stability, and crosslinking within the lignin/PVA composite (LPC) film. A remarkable outcome of this integration is the emergence of a 3D hierarchical microcubic structure within the LPC film. This structure, with its intricate 3D arrangement, emerges as the cornerstone that underpins the development of LPC-TENGs devices distinguished by their simple fabrication process, elevated output performance, and multifaceted applications. The LPC-TENG, adorned with its unique 3D hierarchical microcubic architecture, establishes new standards in energy harvesting and sensing capabilities with a maximum output power density of 135.4 mWm−2, a short-circuit current of 6.44 μA, and a maximum output voltage of 65 V (5 times higher than PVA-based TENGs). Additionally, the LPC-TENG showed exceptional performance as a self-powered bifunctional sensing system, providing a steady output voltage range of 0–10 V across various humidity levels (20–90 % RH) and a wide usable pressure range (0–162 kPa) with a low detection limit of 1 kPa. We demonstrated the application of the LPC-TENG in energy harvesting from human walking, enabling simultaneous measurements of environmental relative humidity, pressure, and illumination of 27 commercial LEDs. The unique 3D hierarchical microcubic architecture offers an unparalleled foundation for accommodating overall performance and diverse sensing functionalities.

Two-Dimensional Electronic Spectroscopy Characterization of Fucoxanthin-Chlorophyll Protein Reveals Excitonic Carotenoid-Chlorophyll Interactions.

Fucoxanthin Chlorophyll Protein (FCP) is a Light Harvesting Complex found in diatoms and brown algae. It is particularly interesting for its efficiency in capturing the blue-green part of the light spectrum due to the presence of specific chromophores (fucoxanthin, chlorophyll a, and chlorophyll c). Recently, the crystallographic structure of FCP was solved, revealing the 3D arrangement of the pigments in the protein scaffold. While this information is helpful for interpreting the spectroscopic features of FCP, it has also raised new questions about the potential interactions between fucoxanthin and chlorophyll c. These interactions were suggested by their spatial closeness but have never been experimentally observed. To investigate this possible interaction mechanism, in this work, two-dimensional electronic spectroscopy (2DES) has been applied to study the ultrafast relaxation dynamics of FCP. The experiments captured an instantaneous delocalization of the excitation among fucoxanthin and chlorophyll c, suggesting the presence of a non-negligible coupling between the chromophores.