Polar Axis Research Articles

Non-Centrosymmetric Single Crystalline Biomolecular Nano-Arrays for Responsive Electronics.

Herein, a novel strategy is reported for synthesizing libraries of single crystalline amino acid (AA) nanocrystals with control over size, anisotropy, and polymorphism by leveraging dip-pen nanolithography (DPN) and recrystallization via solvent vapor annealing. The crystals are prepared by first depositing nanoreactors consisting of a solvent with AAs, followed by water vapor-induced recrystallization. This leads to isotropic structures that are non-centrosymmetric with strong piezoelectric (g33 coefficients >1000mVmN-1), ferroelectric, and non-linear optical properties. However, recrystallizing arrays of isotropic DL-alanine nanodot features with a binary solvent (water and ethanol) leads to arrays of 1D piezoelectric nanorods with their long axis coincident with the polar axis. Moreover, positioning nanoreactors containing AAs (the nanodot features) between micro electrodes leads to capillary formation, making the reactors anisotropic and facilitating piezoelectric nanorod formation between the electrodes. This offers a facile route to device fabrication. These as-fabricated devices respond to ultrasonic stimulation in the form of a piezoelectric response. The technique described herein is significant as it provides a rapid way of investigating non-centrosymmetric nanoscale biocrystals, potentially pivotal for fabricating a new class of stimuli-responsive devices such as sensors, energy harvesters, and stimulators.

Polar Alternating Cations Intercalated Hybrid Perovskite with Iodine‐Substituted Spacers Toward Efficient Passive X‐Ray Detection

Abstract2D hybrid perovskites, with their high X‐ray absorption and extended carrier transport, present excellent promise for efficient direct X‐ray detection. However, most of the current devices require external bias voltage, which results in the need for significant energy consumption and severe ion migration, therefore, it is urgent to develop new types of materials for achieving efficient passive X‐ray detection. Herein, two novel chiral polar alternating cations intercalation (ACI)‐type hybrid perovskite materials, named (R/S‐PPA)(IEA)PbBr4 (1‐R/S, (R/S)‐PPA = R/S‐1‐phenylpropylamine; IEA = iodoethylamine), are constructed by integrating the chiral aromatic spacer R/S‐PPA and the iodine‐substituted spacer IEA. Various intermolecular interactions, such as I···I, C─H···I, π···π interactions, are introduced due to the introduction of I‐substituted chain amines, which effectively suppresses ion migration and thus lead to improved operational stability. The device constructed along the polar axis displays superior X‐ray detection performance, such as relatively high sensitivity and an ultra‐low limit of detection (LoD) of 3.0 nGy s−1, making it the first chiral ACI‐type perovskite material for realizing efficient passive X‐ray detection. Furthermore, 1‐R also presents low dark current drift and exceptional irradiation stability. This work provides new thought for using novel ACI‐type polar perovskite for high‐performance passive direct X‐ray detection.

The First Discovery of Spherical Carborane Molecular Ferroelectric Crystals

AbstractCarborane compounds, known for their exceptional thermal stability and non‐toxic attributes, have garnered widespread utility in medicine, supramolecular design, coordination/organometallic chemistry, and others. Although there is considerable interest among chemists, the integration of suitable carborane molecules into ferroelectric materials remains a formidable challenge. In this study, we employ the quasi‐spherical design strategy to introduce functional groups at the boron vertices of the o‐carborane cage, aiming to reduce molecular symmetry. This approach led to the successful synthesis of the pioneering ferroelectric crystals composed of cage‐like carboranes: 9‐OH‐o‐carborane (1) and 9‐SH‐o‐carborane (2), which undergo above‐room ferroelectric phase transitions (Tc) at approximately 367 K and 347 K. Interestingly, 1 and 2 represent uniaxial and multiaxial ferroelectrics respectively, with 2 exhibiting six polar axes and as many as twelve equivalent polarization directions. As the pioneering instance of carborane ferroelectric crystals, this study introduces a novel structural archetype for molecular ferroelectrics, thereby providing fresh insights into the exploration of molecular ferroelectric crystals with promising applications.

Reduced size, UWB AMC-backed bow-tie antenna compatible with EMI sensor for subsurface impulse radars

Low-profile, wideband, and electromagnetic induction (EMI) sensor-compatible antenna for ground penetrating impulse radar applications is an indispensable need for humanitarian demining operations. We present an ultra wideband (UWB), small-size AMC-backed fat bow-tie antenna for such detection systems. Fat bow-tie has longitudinal slots along its main polarization axis so that Eddy currents due to the EMI sensor are minimized on the antenna. Unlike discrete element or tapered reactive/resistive loading, high-impedance surface material is placed inside the cavity to increase the bandwidth and to decrease the ringing caused by the cavity. The proposed antenna has a directional radiation pattern and operates between 700 MHz and 3.2 GHz.

Camellia neriifolia and Camellia ilicifolia (Theaceae) as separate species: evidence from morphology, anatomy, palynology, molecular systematics

BackgroundThe systematic status of sect. Tuberculata and its taxonomy have recently attracted considerable attention. However, the different bases for defining the characteristics of sect. Tuberculata has led to many disagreements among the plants in this group. Camellia neriifolia and Camellia ilicifolia have been the subject of taxonomic controversy and have been treated as different species or varieties of the same species. Therefore, it is important to use multiple methods, i.e., integrative taxonomy, to determine the taxonomic status of C. neriifolia and C. ilicifolia. This is the first study to systematically explore the taxonomic position of these two plants on the basis of Morphology, Anatomy, Palynology and Molecular Systematics.ResultsExtensive specimen reviews and field surveys showed that many differences exist in C. neriifolia and C. ilicifolia, such as the number of trunk (heavily debarked vs. slightly peeling), leaf type (smooth thin leathery, shiny vs. smooth leathery, obscure or slightly shiny), leaf margin (entire vs. serrate), flower type (subsessile vs. sessile), number of styles (3–4 vs. 3), and sepal (ovate vs. round). Moreover, C. neriifolia has a more distinctive faint yellow flower color, and trunk molting was more severe in C. neriifolia than that in C. ilicifolia. In addition, micromorphological analysis of the leaf epidermis showed that the two species differed in the anticlinal wall, stomatal apparatus, and stomatal cluster, and pollen morphology analyses based on pollen size, germination furrow, and polar and equatorial axes showed that they are both distinct from each other. The results of the phylogenetic tree constructed based on the whole chloroplast genome, protein-coding genes, and ITS2 showed that both C. ilicifolia and C. neriifolia were clustered in different branches and gained high support.ConclusionsThe results combine morphology, anatomy, palynology, and molecular systematics to treat both C. neriifolia and C. ilicifolia as separate species in the sect. Tuberculata, and the species names continue to be used as they were previously. In conclusion, clarifying the taxonomic status of C. neriifolia and C. ilicifolia deepens our understanding of the systematic classification of sect. Tuberculata.

Mass formulas for supergravity black holes with string singularities

We extend the derivation of mass formulas for stationary axisymmetric asymptotically locally flat solutions with string singularities on the polar axis to general supergravity actions containing vector and scalar fields. It is based on the rod structure of the solutions in Weyl coordinates and is applicable to black holes with Dirac and Misner strings. The obtained formulas differ from the corresponding ones in Einstein–Maxwell theory only by summation over all independent electric charges.

The initiation and early development of apical-basal polarity in Toxoplasma gondii.

The human parasite Toxoplasma gondii has a distinctive body plan with a well-defined polarity. In the apical complex, the minus ends of the 22 cortical microtubules are anchored to the apical polar ring, a putative microtubule-organizing center. The basal complex caps and constricts the parasite posterior end, and is critical for cytokinesis. How this apical-basal polarity axis is initiated was unknown. Here we examined the development of the apical polar ring and the basal complex in nascent daughters using expansion microscopy. We found that different substructures in the apical polar ring have different sensitivity to stress. In addition, apical-basal differentiation is already established upon nucleation of the cortical microtubule array: arc forms of the apical polar ring and basal complex associate with opposite ends of the microtubules. As the construction of the daughter framework progresses towards the centrioles, the apical and the basal arcs co-develop in striking synchrony ahead of the microtubule array, and close into a ring-form before all the microtubules are nucleated. We also found that two apical polar ring components, APR2 and KinesinA, act synergistically. The removal of each protein individually has modest to no impact on the lytic cycle. However, the loss of both results in abnormalities in the microtubule array and highly reduced plaquing and invasion efficiency.

Interferon subverts an AHR-JUN axis to promote CXCL13+ T cells in lupus.

Systemic lupus erythematosus (SLE) is prototypical autoimmune disease driven by pathological T cell-B cell interactions1,2. Expansion of T follicular helper (TFH) and T peripheral helper (TPH) cells, two T cell populations that provide help to B cells, is a prominent feature of SLE3,4. Human TFH and TPH cells characteristically produce high levels of the B cell chemoattractant CXCL13 (refs. 5,6), yet regulation of T cell CXCL13 production and the relationship between CXCL13+ T cells and other T cell states remains unclear. Here, we identify an imbalance in CD4+ T cell phenotypes in patients with SLE, with expansion of PD-1+/ICOS+ CXCL13+ T cells and reduction of CD96hi IL-22+ T cells. Using CRISPR screens, we identify the aryl hydrocarbon receptor (AHR) as a potent negative regulator of CXCL13 production by human CD4+ T cells. Transcriptomic, epigenetic and functional studies demonstrate that AHR coordinates with AP-1 family member JUN to prevent CXCL13+ TPH/TFH cell differentiation and promote an IL-22+ phenotype. Type I interferon, a pathogenic driver of SLE7, opposes AHR and JUN to promote T cell production of CXCL13. These results place CXCL13+ TPH/TFH cells on a polarization axis opposite from T helper 22(TH22) cells and reveal AHR, JUN and interferon as key regulators of these divergent T cell states.

Ferroelectric Texture of Individual Barium Titanate Nanocrystals.

Ferroelectric materials display exotic polarization textures at the nanoscale that could be used to improve the energetic efficiency of electronic components. The vast majority of studies were conducted in two dimensions on thin films that can be further nanostructured, but very few studies address the situation of individual isolated nanocrystals (NCs) synthesized in solution, while such structures could have other fields of applications. In this work, we experimentally and theoretically studied the polarization texture of ferroelectric barium titanate (BaTiO3, BTO) NCs attached to a conductive substrate and surrounded by air. We synthesized NCs of well-defined quasicubic shape and 160 nm average size that conserve the tetragonal structure of BTO at room temperature. We then investigated the inverse piezoelectric properties of such pristine individual NCs by vector piezoresponse force microscopy (PFM), taking particular care to suppress electrostatic artifacts. In all of the NCs studied, we could not detect any vertical PFM signal, and the maps of the lateral response all displayed larger displacement amplitude on the edges with deformations converging toward the center. Using field phase simulations dedicated to ferroelectric nanostructures, we were able to predict the equilibrium polarization texture. These simulations revealed that the NC core is composed of 180° up and down domains defining the polar axis that rotate by 90° in the two facets orthogonal to this axis, eventually lying within these planes forming a layer of about 10 nm thickness mainly composed of 180° domains along an edge. From this polarization distribution, we predicted the lateral PFM response, which was revealed to be in very good qualitative agreement with the experimental observations. This work positions PFM as a relevant tool to evaluate the potential of complex ferroelectric nanostructures to be used as sensors.

Influence of catastrophes and hidden dynamical symmetries on ultrafast backscattered photoelectrons

We discuss the effect of using potentials with a Coulomb tail and different degrees of softening in photoelectron momentum distributions (PMDs) using the recently implemented hybrid forward-boundary CQSFA (H-CQSFA). We show that introducing a softening in the Coulomb interaction influences the ridges observed in the PMDs associated with backscattered electron trajectories. In the limit of a hard-core Coulomb interaction, the rescattering ridges close along the polarization axis, while for a soft-core potential, they are interrupted at ridge-specific angles. We analyze the momentum mapping of the different orbits leading to the ridges. For the hard-core potential, there exist two types of saddle-point solutions that coalesce at the ridge. By increasing the softening, we show that two additional solutions emerge as the result of breaking a hidden dynamical symmetry associated exclusively with the Coulomb potential. Further signatures of this symmetry breaking are encountered in subsets of momentum-space trajectories. Finally, we use scattering theory to show how the softening affects the maximal scattering angle and provide estimates that agree with our observations from the CQSFA. This implies that, in the presence of residual binding potentials in the electron's continuum propagation, the distinction between purely kinematic and dynamic caustics becomes blurred. Published by the American Physical Society 2024

3D Ferroelectric Phase Field Simulations of Polycrystalline Multi‐Phase Hafnia and Zirconia Based Ultra‐Thin Films

AbstractHfO2– and ZrO2–based ferroelectric thin films have emerged as promising candidates for the gate oxides of next‐generation electronic devices. Recent work has experimentally demonstrated that a tetragonal/orthorhombic (t/o‐) phase mixture with partially in‐plane polarization can lead to negative capacitance (NC) stabilization. However, there is a discrepancy between experiments and the theoretical understanding of domain formation and domain wall motion in these multi‐phase, polycrystalline materials. Furthermore, the effect of anisotropic domain wall coupling on NC has not been studied so far. Here, 3D phase field simulations of HfO2– and ZrO2–based mixed‐phase ultra‐thin films on silicon are applied to understand the necessary and beneficial conditions for NC stabilization. It is found that smaller ferroelectric grains and a larger angle of the polar axis with respect to the out‐of‐plane direction enhances the NC effect. Furthermore, it is shown that theoretically predicted negative domain wall coupling even along only one axis prevents NC stabilization. Therefore, it is concluded that topological domain walls play a critical role in experimentally observed NC phenomena in HfO2– and ZrO2–based ferroelectrics.

Dynamic model of single-DOF spherical mechanisms based on instantaneous pole axes and Eksergian's equation

Instantaneous pole axes (IPAs) fully describe instantaneous kinematics of spherical mechanisms. In single-degree-of-freedom (single-DOF) mechanisms, IPAs’ locations uniquely depend on the mechanism configuration. Such a property allows the deduction of instantaneous-motion characteristics by means of analytic techniques based on geometric features of the mechanism configuration. Moreover, these geometric/analytic approaches are extendable to mechanism's static analyses since the virtual work principle relates mechanism's statics to its instantaneous kinematics. Analytic approaches based on geometric reasoning are of interest in mechanism design and their further extension to dynamic analyses is appealing in that context. This work proposes a possible extension of IPA-based techniques to dynamic analyses of single-DOF spherical mechanisms by using Eksergian's equation. A novel general dynamic model for single-DOF spherical mechanisms is proposed, which is based on IPAs’ locations. Then, the effectiveness of the proposed model is applied to a relevant single-DOF spherical mechanism.

Decreased “Polar Axis Angle” is Associated With Instability After Total Hip Arthroplasty: A New Method to Assess Functional Component Position on Lateral-Seated Radiographs

BackgroundResearch on hip instability has focused on establishing “safe” ranges of combined component position in supine posture or functional placement of the acetabular component based on the hip-spine relationship. A new angle, the polar axis angle (PAA), of the total hip arthroplasty (THA) components describes the concentricity of both components and can be evaluated in functional positions that confer a greater risk of instability (ie, sitting). The goal of this study was to compare the PAA in functional positions between patients who experienced a postoperative dislocation and a matched control group who did not have a dislocation. MethodsAn institutional database was searched for patients experiencing a dislocation after primary THA. Patients who had postoperative full-length standing and lateral-seatedradiographs were included in the dislocator group. A control group of nondislocator patients was matched 2:1 by age, body mass index, sex, and hip-spine classification. Radiographic measurements of the neck angle, acetabular ante-inclination, and PAA were performed by 2 separate blinded, trained reviewers. ResultsThe lateral-seated neck angle and lateral-seated PAA measurements were significantly lower in the dislocator groups (n = 37) than the control group (n = 74) (23 versus 33 degrees, P < .001; 74 versus 83 degrees, P = .012, respectively). Significant differences were also observed in changes in the polar axes and neck angles between standing and seated positions (P < .001 and P < .001, respectively). When comparing patients who have mobile spines versus stiff spines within the dislocator group, there were no differences in the acetabular, neck, or PAAs. The effect of neck angle on the PAA showed a linear trend across cohorts. ConclusionsPatients who experience postoperative instability have a significantly lower PAA on lateral-seated radiographs when matched for age, sex, body mass index, and hip-spine classification. In addition, the lower seated PAA is driven more strongly by decreased functional femoral anteversion, which emphasizes the role of functional femoral version on stability in THA.

VASCilia (Vision Analysis StereoCilia): A Napari Plugin for Deep Learning-Based 3D Analysis of Cochlear Hair Cell Stereocilia Bundles.

Cochlear hair cell stereocilia bundles are key organelles required for normal hearing. Often, deafness mutations cause aberrant stereocilia heights or morphology that are visually apparent but challenging to quantify. Actin-based structures, stereocilia are easily and most often labeled with phalloidin then imaged with 3D confocal microscopy. Unfortunately, phalloidin non-specifically labels all the actin in the tissue and cells and therefore results in a challenging segmentation task wherein the stereocilia phalloidin signal must be separated from the rest of the tissue. This can require many hours of manual human effort for each 3D confocal image stack. Currently, there are no existing software pipelines that provide an end-to-end automated solution for 3D stereocilia bundle instance segmentation. Here we introduce VASCilia, a Napari plugin designed to automatically generate 3D instance segmentation and analysis of 3D confocal images of cochlear hair cell stereocilia bundles stained with phalloidin. This plugin combines user-friendly manual controls with advanced deep learning-based features to streamline analyses. With VASCilia, users can begin their analysis by loading image stacks. The software automatically preprocesses these samples and displays them in Napari. At this stage, users can select their desired range of z-slices, adjust their orientation, and initiate 3D instance segmentation. After segmentation, users can remove any undesired regions and obtain measurements including volume, centroids, and surface area. VASCilia introduces unique features that measures bundle heights, determines their orientation with respect to planar polarity axis, and quantifies the fluorescence intensity within each bundle. The plugin is also equipped with trained deep learning models that differentiate between inner hair cells and outer hair cells and predicts their tonotopic position within the cochlea spiral. Additionally, the plugin includes a training section that allows other laboratories to fine-tune our model with their own data, provides responsive mechanisms for manual corrections through event-handlers that check user actions, and allows users to share their analyses by uploading a pickle file containing all intermediate results. We believe this software will become a valuable resource for the cochlea research community, which has traditionally lacked specialized deep learning-based tools for obtaining high-throughput image quantitation. Furthermore, we plan to release our code along with a manually annotated dataset that includes approximately 55 3D stacks featuring instance segmentation. This dataset comprises a total of 1,870 instances of hair cells, distributed between 410 inner hair cells and 1,460 outer hair cells, all annotated in 3D. As the first open-source dataset of its kind, we aim to establish a foundational resource for constructing a comprehensive atlas of cochlea hair cell images. Together, this open-source tool will greatly accelerate the analysis of stereocilia bundles and demonstrates the power of deep learning-based algorithms for challenging segmentation tasks in biological imaging research. Ultimately, this initiative will support the development of foundational models adaptable to various species, markers, and imaging scales to advance and accelerate research within the cochlea research community.

Tunable broadband polarization retarders.

We theoretically propose a type of tunable polarization retarder, which is composed of sequences of half-wave and quarter-wave polarization retarders, allowing operation at broad spectral bandwidth. The constituent retarders are composed of stacked standard half-wave retarders and quarter-wave retarders rotated at designated angles relative to their fast polarization axes. The proposed composite retarder (CR) can be tuned to an arbitrary value of the retardance by varying the middle retarder alone while maintaining its broadband spectral bandwidth intact.

Contribution to the biosystematics of the wild Vaccinium species distributed in Turkey

The genus Vaccinium L. (Ericaceae) consists of shrubs or dwarf shrubs species widely distributed in Southeast Asia, America, and Europe. In the present paper, members of the genus (V. arctostaphylos, V. myrtillus, V. uliginosum, V. vitis-idaea) naturally grown in Northeast Anatolia were compared in terms of leaf venation, seed micromorphology, and palynological properties based on 16 populations in detail. Present findings revealed that number of areoles (the small area bounded by secondary veinlet) is 8–9 for V. arctostaphylos, 5–7 for V. myrtillus, 3–4 for V. uliginosum and V. vitis-idaea. Scanning electron microscope observation shows that the leaf adaxial surface is fiber-fluted in V. arctostaphylos, ruminate in V. myrtillus, V. uliginosum, and V. vitis-idaea due to epicuticular waxes. In addition, the seed shape of V. arctostaphylos in outline varies from triangular, tetragonal to oval, whereas they are lunate to reniform or falcate in the rest of the examined taxa. Epidermal cells of the seed are quadrilateral with straight anticlinal walls in V. arctostaphylos, however, they are most elongate rectangle with weakly undulate anticlinal walls in the rest species. The mean tetrad diameter (D) of pollen belonging to all examined species is 29.89 (21.47–43.22) μm while the lowest mean D was found in V. uliginosum (24.59 μm) and the highest mean D was found in V. arctostaphylos (36.74 μm). Principal component analysis based on 47 traits (flower: 9, leaf: 18, seed and fruit: 9 and pollen: 11) showed that the leaf length and width, teeth numbers, tetrad diameter, equatorial axis, and polar axis were the most valuable characters to distinguish the examined taxa in the present paper.

TBX3 is essential for establishment of the posterior boundary of anterior genes and upregulation of posterior genes together with HAND2 during the onset of limb bud development.

During limb bud formation, axis polarities are established as evidenced by the spatially restricted expression of key regulator genes. In particular, the mutually antagonistic interaction between the GLI3 repressor and HAND2 results in distinct and non-overlapping anterior-distal Gli3 and posterior Hand2 expression domains. This is a hallmark of the establishment of antero-posterior limb axis polarity, together with spatially restricted expression of homeodomain and other transcriptional regulators. Here, we show that TBX3 is required for establishment of the posterior expression boundary of anterior genes in mouse limb buds. ChIP-seq and differential gene expression analysis of wild-type and mutant limb buds identifies TBX3-specific and shared TBX3-HAND2 target genes. High sensitivity fluorescent whole-mount in situ hybridisation shows that the posterior expression boundaries of anterior genes are positioned by TBX3-mediated repression, which excludes anterior genes such as Gli3, Alx4, Hand1 and Irx3/5 from the posterior limb bud mesenchyme. This exclusion delineates the posterior mesenchymal territory competent to establish the Shh-expressing limb bud organiser. In turn, HAND2 is required for Shh activation and cooperates with TBX3 to upregulate shared posterior identity target genes in early limb buds.

Noncollinear Electric Dipoles in a Polar Chiral Phase of CsSnBr3 Perovskite.

Polar and chiral crystal symmetries confer a variety of potentially useful functionalities upon solids by coupling otherwise noninteracting mechanical, electronic, optical, and magnetic degrees of freedom. We describe two phases of the 3D perovskite, CsSnBr3, which emerge below 85 K due to the formation of Sn(II) lone pairs and their interaction with extant octahedral tilts. Phase II (77 K < T < 85 K, space group P21/m) exhibits ferroaxial order driven by a noncollinear pattern of lone pair-driven distortions within the plane normal to the unique octahedral tilt axis, preserving the inversion symmetry observed at higher temperatures. Phase I (T < 77 K, space group P21) additionally exhibits ferroelectric order due to distortions along the unique tilt axis, breaking both inversion and mirror symmetries. This polar and chiral phase exhibits second harmonic generation from the bulk and pronounced electrostriction and negative thermal expansion along the polar axis (Q22 ≈ 1.1 m4 C-2; αb = -7.8 × 10-5 K-1) through the onset of polarization. The structures of phases I and II were predicted by recursively following harmonic phonon instabilities to generate a tree of candidate structures and subsequently corroborated by synchrotron X-ray powder diffraction and polarized Raman and 81Br nuclear quadrupole resonance spectroscopies. Preliminary attempts to suppress unintentional hole doping to allow for ferroelectric switching are described. Together, the polar symmetry, small band gap, large spin-orbit splitting of Sn 5p orbitals, and predicted strain sensitivity of the symmetry-breaking distortions suggest bulk samples and epitaxial films of CsSnBr3 or its neighboring solid solutions as candidates for bulk Rashba effects.

Film thickness characterization in dual-axis spin coating of a sphere

The versatility of spin coating technology makes it a preferred method for producing the thin film layers used to manufacture products from solar panels and smartphones to sunglasses and CDs. However, the process requires a flat, rigid substrate to produce uniform films, which limits its use to planar devices. A novel multi-axis manipulator has been developed to extend the application of spin coating, enabling controlled thin film deposition onto curved surfaces. Various rotational schemes were studied to link the flow of a liquid film over a curved surface to forces induced by complex rotational dynamics. When the angular velocity exceeds a threshold, centrifugal force dominates the flow, pushing the fluid away from the instantaneous axis of rotation. This produces axisymmetric coating profiles when using consistent single or dual-axis rotation. Areas of near uniformity present around the spin axis poles for single-axis rotation and around the substrate’s equator for dual-axis schemes. Sensitivities between the spherical substrate dynamics and the evolving fluid flow were investigated, exploring the parameters that promoted the production of uniform curved film layers for microfabrication processes. This enabled the evolution of the spin coating technique to effectively form curved polymer coatings with improved thickness control. The presented research outlines the capabilities of a multi-axis spin coating machine when used to coat spherical substrates. Therefore, enabling the use of fluid mechanics models to identify the optimal motion kinematics required to create uniform curved films.

Catalytic Dual-Mode Immunotherapy: Anisotropic AuPt Heterostructure Decorated with Starry Pt Nanoclusters for Robust Cancer Photometalloimmunotherapy.

To overcome current limitations in photoimmunotherapy, such as insufficient tumor antigen generation and a subdued immune response, a novel photo-/metallo dual-mode immunotherapeutic agent (PMIA) is introduced for potent near-infrared (NIR) light-triggered cancer therapy. PMIA features a dumbbell-like AuPt heterostructure decorated with starry Pt nanoclusters, meticulously engineered for enhancing plasmonic catalysis through multi-dimensional regulation of Pt growth on Au nanorods. Under NIR laser exposure, end-tipped Pt nanoclusters induce efficient electron-hole spatial separation along the longitudinal axis, resulting in radial and axial electron distribution polarization, conferring unique anisotropic properties to PMIA. Additionally, starry Pt nanoclusters on the sides of Au nanorods augment the local electron enrichment field. Validated through finite-difference time-domain analysis and Raman scattering, this configuration fosters local electron enrichment, facilitating robust reactive oxygen species generation for potent photoimmunotherapy. Moreover, Pt nanoclusters facilitate Pt2+ ion release, instigating intranuclear DNA damage and inducing synergistic immunogenic cell death (ICD) for metalloimmunotherapy. Consequently, PMIA elicits abundant danger-associated molecular patterns, promotes T cell infiltration, and triggers systemic immune responses, effectively treating primary and distant tumors, inhibiting metastasis in vivo. This study unveils a pioneering dual-mode ICD amplification strategy driven by NIR light, synergistically integrating photoimmunotherapy and metalloimmunotherapy, culminating in potent cancer photometalloimmunotherapy.