Primitive Cell Research Articles

PYATB: An efficient Python package for electronic structure calculations using ab initio tight-binding model

We present PYATB, a Python package designed for computing band structures and related properties of materials using the ab initio tight-binding Hamiltonian. The Hamiltonian is directly obtained after conducting self-consistent calculations with first-principles packages using numerical atomic orbital bases, such as ABACUS. The package comprises three modules: Bands, Geometric, and Optical. In the Bands module, one can calculate essential properties of band structures, including the partial density of states, fat bands, Fermi surfaces, and Weyl/Dirac points. The band unfolding method is utilized to obtain the energy band spectra of a supercell by projecting the electronic structure of the supercell onto the Brillouin zone of the primitive cell. With the Geometric module, one can compute the Berry phase and Berry curvature-related quantities, such as electric polarization, Wilson loops, Chern numbers, and anomalous Hall conductivities. The Optical module offers a range of optical property calculations, including optical conductivity and nonlinear optical responses, such as shift current and Berry curvature dipole. Program summaryProgram title: PYATBCPC Library link to program files:https://doi.org/10.17632/fsfpdy9t5r.1Developer's repository link:https://github.com/pyatb/pyatbCode Ocean capsule:https://codeocean.com/capsule/9408682Licensing provisions: GPLv3Programming language: C++, PythonNature of problem: This program is to study the electronic structure, electronic polarization, band topological properties, topological classification, linear and nonlinear optical response of solid crystal systems.Solution method: Based on the tight binding method to solve the band structure, the Wilson loop is used to classify the topological phases, and the optical response is calculated by Berry curvature and Berry connection.

Photonic Realization of a Generic Type of Graphene Edge States Exhibiting Topological Flat Band.

Cutting a honeycomb lattice (HCL) ends up with three types of edges (zigzag, bearded, and armchair), as is well known in the study of graphene edge states. Here, we propose and demonstrate a distinctive twig-shaped edge, thereby observing new edge states using a photonic platform. Our main findings are (i)the twig edge is a generic type of HCL edge complementary to the armchair edge, formed by choosing the right primitive cell rather than simple lattice cutting or Klein edge modification; (ii)the twig edge states form a complete flat band across the Brillouin zone with zero-energy degeneracy, characterized by nontrivial topological winding of the lattice Hamiltonian; (iii)the twig edge states can be elongated or compactly localized at the boundary, manifesting both flat band and topological features. Although realized here in a photonic graphene, such twig edge states should exist in other synthetic HCL structures. Moreover, our results may broaden the understanding of graphene edge states, as well as new avenues for realization of robust edge localization and nontrivial topological phases based on Dirac-like materials.

Harmonic oscillations of point soliton (Bloch point) in cylindrical ferromagnetic nanowire

Harmonic oscillations of a point magnetic soliton (Bloch point) located in a domain wall (DW) of a cylindrical ferromagnetic nanowire along the spatial directions of a primitive vortex cell formed by the magnetization vectors at the boundary between the core and the transition zone of the soliton are considered. The possibility of experimental implementation of Bloch point resonant oscillations excited by external alternating magnetic field is shown. In the case of weak attenuation, the maximum values of the resonant frequencies of Bloch points in iron and nickel nanowires are determined, which are 10 and 3 GHz, respectively. These results can be applied in the modern nanotechnologies based on the use of the magnetic properties of ferromagnetic nanowires whose DWs contain Bloch points.

Qualitative analyses of thin film-based materials validating new structures of atoms

An X-ray instrument is a paramount technique for analyzing the structures of electronic and crystalline materials. In materials chemistry and physics, discussing the results of X-ray techniques is a routine job. In the thin film, powder, bulk, or another form of material, suitable electronic rings of the atoms forming the top-layered surface experience X-rays. Reflection and inverse reflection of X-rays define the peaks upon interaction with left and right-sided segments of electronic tips constructing suitable rings of atoms. In X-ray analysis, X-rays interact with the north side of the electrons. The X-rays interact with the electrons from the left side when the incidence of X-rays is from the left side. If the 2θ is also less than 90°, the X-ray incidence is from the downward side, so the X-rays get reflected tangentially to the inward sides recording intensity at the position of the detector. When the incidence of X-rays is from the right side, the X-rays interact with the electrons from the right side. As the 2θ is greater than 90°, the X-ray incidence is from the upward side. The X-rays get reflected tangentially mainly to the outer sides, thus not recording intensity at the position of the detector. The present work discusses the X-ray patterns of titanium nitride coating, carbon film rich in nanocrystalline diamond phase, and tantalum carbide film in preliminary detail. In developing electronic or crystalline materials, a primitive cell does not form a basis of a crystal structure. A lattice constant appears to be irrelevant now. The 2θ length between the peaks depends on the distance between the associated electronic rings of atoms. The results of this study agree with the atomic and electronic structure presented under the new insight.

Magnetic and Electric Properties and Their Regulation of the Intrinsic Half‐Metallic Multiferroic Monolayers AV2S4

Abstract2D half‐metallic multiferroic materials have attracted great interest due to their rich novel performances and wide application prospect in nanoelectronics and nanodevices. Three intrinsic half‐metallic multiferroic monolayers AV2S4 (A = Na, K, and Rb) are predicted based on the first‐principles calculations. From the calculations, their ground states are all ferromagnetic and are completely spin‐polarized at the Fermi level. Their total magnetic moments are always 3.00 μB per primitive cell, which origin mainly from V‐ions. The two‐center electronic structure t2g6↑t2g4↓eg1↑ of V‐ions is proposed from the perspective of the crystal field theory to explain successfully the calculated magnetic moments. Interestingly, the alkali‐metal ions are non‐magnetic, but they may cause important influence on the magnetic coupling between transition ions, and then the half‐metallicity of these monolayers. Their electric and magnetic properties may be tuned by their charge states and strains. Especially, their half‐metallic stability may be evidently improved by the tensile strains. The half‐metallic gaps of these monolayers may be increased by about 67.4%, 50.8%, and 32.4% for NaV2S4, KV2S4, and RbV2S4 by the tensile strain 2.0%, respectively.

Tunable elastic topological insulators based on bicomponent perforated structures

In this paper, a tunable elastic topological insulator based on bicomponent is designed. We rotate the perforated structure of the mixed components in two different ways, local and global, to reduce the structural symmetry of the lattice and obtain the elastic topological insulator. By introducing a mixed-component perforated structure with a certain rotation angle into the primitive cell, the symmetry is incomplete and the quadruple degenerate state is constructed. When locally rotating mixed component perforated structure, the quadruple degenerate state is separated and reversed at point, and we can get a structure with topological properties. In addition, without re-constructing the perforated structure parameters of the unit cell, when the mixed component perforated structure is rotated as a whole, we can also realize the elastic topological insulator, and its non-trivial band gap is widened by about three times. Finally, we verify the transport properties of the topological boundary states of the elastic topological insulator by both numerical simulations and experimental tests.

Respiratory viruses induce the expression of type I and III IFNs in MSCs through RLR/IRF3 signaling pathways

Mesenchymal stem cells (MSCs) comprise a primitive cell population and reside in various tissues and organs. These cells exhibit immunomodulatory activity and are effective in treating respiratory viral infections. The activation of type I and III interferons, which protect cells against viral infections, can be induced after pattern recognition receptors (PRRs) recognize viral nucleic acid species. Although certain viruses can upregulate IFN-β expression in MSCs, the underlying mechanisms and responsiveness to different IFNs are unclear. We found that foreskin-derived fibroblast-like stromal cells (FDSCs), a kind of functional MSC, were permissive to IAV PR8, HCoV-229E, and EV-D68. Infection by IAV PR8 and HCoV-229E increased the expression of IFN-β and IFN-λ species in FDSCs in an IRF-3-dependent manner. RIG-I was critical for detecting IAV PR8 in FDSCs, and IAV PR8 infection induced a significant increase in the expression of interferon signaling genes (ISGs). Interestingly, only IFN-β, but not IFN-λ species, could induce the expression of ISGs, a finding supported by our observation that only IFN-β induced STAT1 and STAT2 phosphorylation in FDSCs. We also proved that treatment with IFN-β suppressed the propagation of IAV PR8 and promoted the survival of virus-infected FDSCs. Respiratory viruses could infect FDSCs and induce the expression of IFN-β and IFN-λ1, but only IFN-β could protect FDSCs against viral infection.

Bismuth Phase Dependent Growth of Superconducting NiBi3 Nanorods

We report a study on the growth of NiBi3 nanowires and nanorods during the preparation of superconducting NiBi3 films by co-evaporation of Ni and Bi. We find that NiBi3 films grown via co-evaporation of Ni and Bi metals achieve higher transition temperatures (4.4 K) compared even to the single crystal NiBi3. However, in certain parameter space, the film surfaces were spattered with nanoscale features, such as nanowires and nanorods. Ambient temperature deposition resulted in poly-crystalline NiBi3 nanorods which were controllable with the evaporation rate of Bi. Deposition at elevated temperatures promoted the emergence of long single crystalline NiBi3 nanorods. High resolution transmission electron microscopy measurements confirmed the crystalline behaviour of the nanorods. We believe that NiBi3 nanowires form in a process analogous to the well known vapor-liquid-solid process, as we observe an amorphous Bi cap on the nanorods. From glancing angle X-ray diffraction measurements we identify that the presence of trigonal Bi with hexagonal primitive cell in the film promotes the nucleation of nanorods. Electrical transport on a single NiBi3 nanowire shows a superconducting transition of 4.3 K.

Band unfolding with a general transformation matrix: From code implementation to interpretation of photoemission spectra

Unfolding of a supercell band structure into a primitive Brillouin zone is important for understanding implications of structural distortions, disorder, defects, and solid solutions on materials electronic structure. The necessity of band unfolding is also recognized in the interpretation of angle-resolved photoemission spectroscopy (ARPES) measurements. We describe an extension of the fold2Bloch package by implementing an arbitrary transformation matrix used to establish a relation between the primitive cell and supercell. This development allows us to overcome limitations of supercells constructed exclusively by scaling of primitive cell lattice vectors. It becomes possible to transform between primitive and conventional cells as well as include rotations. The fold2Bloch is publicly available from a GitHub repository as a FORTRAN code. It interfaces with the all-electron full-potential WIEN2k and the pseudopotential VASP density functional theory packages. The fold2Bloch is supplemented by additional pre- and post-processing utilities that aid in generating k points in the supercell (such that they later fall onto a desired path in the primitive Brillouin zone after unfolding) and plotting the unfolded band structure. We selected ▪ as an illustrative example and, for the first time, present its properly unfolded band structure in direct comparison with ARPES measurements. In addition, critical importance of the band unfolding for interpretation of ▪ ARPES data is illustrated and discussed as a perspective.

SINGLE CRYSTALS GROWTH IN THE HOMOGENEITY REGION OF LOW-TEMPERATURE MODIFICATION OF Ag8GeS6

Cationic ion-conductors have found wide practical application as electric batteries. Among them the lithium-ion batteries are the most common commercially used. However, research is being actively carried out to improve the safety of these batteries. Among the possible compounds, silver-containing phases are attractive, since silver-ions, along with high values of ionic conductivity in solid-state, haven’t high chemical activity like the same alkali metal-ions. Realization of the crystal structure necessary for effective ion transport is observed in compounds of the argyrodite structure - a group of ternary chalcogenides and quaternary chalcohalogenides of multi-charged cations (Ge4+, Si4+, P5+). In this work, a study of heterovalent cationic P5+→Ge4+ substitution in the Ag8GeS6 enriched region was carried out. Single crystals of Ag8-x(Ge1-xPx)S6 (x = 0.25; 0.5) solid solutions were grown by the method of directional crystallization using a solution-melt technique. The grown single crystals are characterized by the absence of macrodefects, a dark gray color with a metallic luster, and dimensions of l = ~3 cm and d = 1.2 cm. Using the Rietveld refinement method, the crystal structure was established and the lattice parameters of Ag8-x(Ge1-xPx)S6 (x = 0.25; 0.5) solid solutions were determined. Established, that single crystals of Ag8-x(Ge1-xPx)S6 (x = 0.25; 0.5) solid solutions crystallize in the orthorhombic crystal system in a primitive cell with space group Pna21.
 Keywords: argyrodites; single crystals; directional crystallization; phase analysis.

SINGLE CRYSTALS GROWTH OF Ag7+x(P1-xGex)S6 (x = 0.1; 0.25; 0.33) SOLID SOLUTIONS

Ternary silver argyrodites exhibit a wide range of properties and are classified as promising solid-state conductors, thermoelectrics, photovoltaic and nonlinear optical materials. This is ensured by the peculiarity of the crystal structure of argyrodites, which combines a rigid anionic and a disordered cationic sublattice. This work is devoted to the development of a technological regime for growing high-quality single-crystalline samples of Ag7+x(P1-xGex)S6 (x = 0.1; 0.25; 0.33) solid solutions by the method of directed crystallization from the melt. Polycrystalline alloys of Ag7+x(P1-xGex)S6 (x = 0.1; 0.25; 0.33) solid solution were obtained from previously synthesized ternary Ag7PS6 and Ag8GeS6. The synthesis was carried out by a single-stage and single-temperature method at a maximum temperature of 1010°C. The phase composition of the synthesized alloys was determined by the XRD method. Phase analysis of the obtained polycrystalline alloys did not reveal reflections of impurity phases. The results of thermal studies of Ag7+x(P1-xGex)S6 alloys were used to develop a technological regime for single crystals growth. Ag7+x(P1-xGex)S6 single crystal was grown from the melt by the directional crystallization method. As a result of the research, high-quality single crystals of Ag7+x(P1-xGex)S6 solid solutions (x = 0.1; 0.25; 0.33) were obtained. According to the results of X-ray diffraction, it was established that the solid solution of the composition Ag7.1(P0.9Ge0.1)S6 crystallizes in the primitive cubic cell of SG P213, and the solid solutions Ag7.25(P0.75Ge0.25)S6 and Ag7.33(P0.67Ge0.33)S6 crystallizes in a metastable at room temperature high-temperature modification with SG F-43m.
 Keywords: argyrodites; single crystals; directional crystallization; phase analysis.

The fracture toughness of Schwarz Primitive triply periodic minimal surface lattice

Triply periodic minimal surface (TPMS) lattices have recently been shown to exhibit extraordinarily low densities and multi-functionalities. Nevertheless, the dependence of their fracture toughness KIc on relative density ρ¯, unit cell size l and the number of unit cells ahead of the crack tip suggest a lack of understanding of the governing parameters. This also extends to the adequacy of using the current conventional fracture testing protocols. Therefore, the objective of this work is threefold: (i) extract the minimum Schwarz Primitive unit cells for accurate toughness measurement, (ii) estimate KIc of polylactic acid Schwarz Primitive TPMS applying linear elastic fracture mechanics (LEFM) conditions, (iii) investigate the effect of relative density ρ¯ and unit cell size l on the fracture toughness. With 18 cells along the specimen width, KIc is shown to increase linearly with ρ¯ and with the square root of l. Outcomes from this work is aimed toward understanding the damage tolerance of TPMS lattices, and hence the reliability of such new emerging lightweight materials.

Abstract #1407996: Co-secreting Pituitary Tumors: A Clinical Challenge

Co-secreting pituitary adenomas are rare, with complex clinical presentation and challenging long-term management. We present a small case series of co-secreting pituitary tumors, highlighting the importance of evaluating all pituitary hormones in the setting of a pituitary adenoma. Case 1: Active acromegaly with a functioning pituitary FSHoma A 46-year-old married male, presented with bilateral vision loss, headache, and weight gain for the last 18 months. He had also noticed enlarging hands and decreased libido. He was obese (BMI of 32.2 Kg/m2). Red reflex was present in the right eye, while temporal hemianopia was noted in the left eye. He had phenotypic features of acromegaly, had enlarged testicles measuring more than 25mls bilaterally. Acromegaly and FSHoma were confirmed with raised IGF-1 levels (733.70 ng/ml) and FSH levels, checked twice (108.9 & 107 mIU/ml respectively) with low LH (2.40 mIU/ml) and T (1.27 pg/ml); PRL, ACTH, and TSH were normal. MRI pituitary revealed a large mass measuring ∼ 2.9 x 3.6 x 4.7 cm. He was referred for pituitary surgery but was lost to follow-up thereafter. Case 2, 3, 4, 5: Acromegaly with co-secretion of prolactin Two single females, aged 18, and 33; one married, aged 33, and a 23-year-old single male presented with enlarging hands and feet and weight gain. All females had secondary amenorrhoea and galactorrhoea. A male patient and two of the females also had headaches and visual disturbances. The youngest of them did not have any classical signs of acromegaly but had bitemporal hemianopia. The male patient had right-sided temporal hemianopia. They all had raised IGF-1 levels (1195.0, 701.0, 1136.0, & 516.7ng/mL). PRL levels were 458.1, 303.0, 53.0, and 1825 ng/ml. Their LH, FSH, and FT4 levels were low. All had normal ACTH and Cortisol levels. MRI pituitary revealed pituitary macroadenomas. All were started with cabergoline and referred for surgery. Only the youngest patient underwent surgery. The other three declined surgery for the time being and were started on monthly long-acting Octreotide. Case 6: Prolactinoma with late co-secretion of growth hormone A 40-year-old female, with a history of micro prolactinoma diagnosed in 2004, recently presented in 2021 with complaints of enlarging hands and feet. There was no history of headache or visual symptoms. She presented, 16 years ago with secondary amenorrhoea with isolated hyperprolactinemia. Her MRI showed a pituitary mass measuring 1.2 x1.6 cm. Since that time, she was on cabergoline. She also had subtle signs of acromegaly. Showed raised IGF-1 (410.0) and GH nadir of 3.12mcg/L after a 75 g oral glucose challenge. Her FSH, LH, Estradiol, FT4, and cortisol were normal, while PRL was raised (49.6 ng/ml). Her cabergoline dose was increased and was referred for Trans-sphenoidal surgery. The literature review revealed a very rare synchronous presentation of acromegaly and FSH-secreting pituitary adenoma. FSH and FSHoma is specified in the etiology of macroorchidism, as present in our case. Up to 25% of GH adenomas co-secrete prolactin. The Third Type occurs due to Primitive acidophilic stem cell adenomas with dual hormone secretion from a single cell.

Generalization of the Singum Model for the Elasticity Prediction of Lattice Metamaterials and Composites

The recently developed singum model was extended to lattice metamaterials and composites for prediction of the effective elasticity based on the stiffness of the lattice components and the structure of the lattice, in which the load is transferred through the lattice network represented by unit cells that can contain one or more singums. The equilibrium of the singums was considered under a displacement variation, and the relation between the variations of averaged stress and strain can be evaluated to predict the elasticity. It was proved that the stiffness of any unit cells is the same as that of the primitive cell. A generalized formulation was developed to calculate the effective elasticity of lattice metamaterials and composites, which reflects the symmetry and anisotropic feature of the lattice more accurately. A hydrostatic load does not change the shape of the singum but changes its elasticity, although the bonds are linear elastic. The formulation shows the prestress-dependent elasticity for lattice metamaterials. When a large uniform biaxial tension is applied, a honeycomb lattice can exhibit a negative Poisson’s ratio under a pre-tension. Case studies of auxetic and body-centered cubic lattices were conducted to demonstrate the negative Poisson’s ratio and anisotropic elasticity, respectively.

The Stiffest and Strongest Predicted Material: C2 N Atomic Chains Approach the Theoretical Limits.

Though linear atomic chains exhibit extreme properties, it is presently unclear how these properties can be maximized by the choice of elemental composition. Considering that boron, carbon, and nitrogen can form high modulus and high strength atomic chains, here an algorithm is developed to construct 143 possible atomic chains of these elements with 6 or fewer atoms in the primitive cell and explore their stabilities and mechanical properties by first-principles calculations. It is found that the gravimetric modulus (1032 GPa g-1 cm3 ) and strength (108 GPa g-1 cm3 ) of the C2 N chain significantly exceed those of any known material, including the previously stiffest predicted material (C chain, 945 GPa g-1 cm3 ) and the previously strongest predicted material (BC chain, 92 GPa g-1 cm3 ), and also approach the theoretical limits of gravimetric modulus (1036 GPa g-1 cm3 ) and strength (130 GPa g-1 cm3 ). Mechanistic analyses demonstrate that the higher gravimetric modulus and strength of the C2 N chain, compared with the C and BC chains, originate from its short, stiff chemical bonding and the abnormal decrease in bond length alternation under tension. The likely ease of fabrication and potential synthesis routes for C2 N chains are discussed.

Partial Order-Disorder Transition Driving Closure of Band Gap: Example of Thermoelectric Clathrates.

In the quest for efficient thermoelectrics, semiconducting behavior is a targeted property. Yet, this is often difficult to achieve due to the complex interplay between electronic structure, temperature, and disorder. We find this to be the case for the thermoelectric clathrate Ba_{8}Al_{16}Si_{30}: Although this material exhibits a band gap in its ground state, a temperature-driven partial order-disorder transition leads to its effective closing. This finding is enabled by a novel approach to calculate the temperature-dependent effective band structure of alloys. Our method fully accounts for the effects of short-range order and can be applied to complex alloys with many atoms in the primitive cell, without relying on effective medium approximations.

Machine learning guided high-throughput search of non-oxide garnets

Garnets have found important applications in modern technologies including magnetorestriction, spintronics, lithium batteries, etc. The overwhelming majority of experimentally known garnets are oxides, while explorations (experimental or theoretical) for the rest of the chemical space have been limited in scope. A key issue is that the garnet structure has a large primitive unit cell, requiring a substantial amount of computational resources. To perform a comprehensive search of the complete chemical space for new garnets, we combine recent progress in graph neural networks with high-throughput calculations. We apply the machine learning model to identify the potentially (meta-)stable garnet systems before performing systematic density-functional calculations to validate the predictions. We discover more than 600 ternary garnets with distances to the convex hull below 100 meV ⋅ atom−1. This includes sulfide, nitride, and halide garnets. We analyze their electronic structure and discuss the connection between the value of the electronic band gap and charge balance.

Study of the Effects of Er Doping on the Physical Properties of CdSe Thin Films

Erbium-doped cadmium selenide thin films grown on 7059 Corning glass by means of a chemical bath at 80 °C were prepared. Doping was performed by adding an aqueous Er(NO3)33·H2O dilution to the CdSe growth solution. The volume of Er doping solution was varied to obtain different Er concentration (x at%). Thus, in the Cd1−xErxSe samples, the x values obtained were in the 0.0–7.8 at% interval. The set of the CdSe:Er thin films synthesized in the hexagonal wurtzite (WZ) crystalline phase are characterized by lattice parameters (a and c) that increase until x = 2.4% and that subsequently decrease as the concentration of x increases. Therefore, in the primitive unit cell volume (UC), the same effect was observed. Physical parameters such as nanocrystal size, direct band gap (Eg), and optical longitudinal vibrational phonon on the other hand, shift in an opposite way to that of UC as a function of x. All the samples exhibit photoluminescence (PL) emission which consists of a single broad band in the 1.3 ≤ hν ≤ 2.5 eV range (954 ≥ λ ≥ 496 nm), where the maximum of the PL-band shift depends on x in the same way as the former parameters. The PL band intensity shows a singular behavior since it increases as x augments but exhibits a strong decreasing trend in the intermediate region of the x range. Dark d.c. conductivity experiences a high increase with the lower x value, however, it gradually decreases as x increases, which suggests that the Er3+ ions are not only located in Cd2+ sites, but also in interstitial sites and at the surface. Different physical properties are correlated among them and discussed considering information from similar reports in the literature.

Abstract LB363: Patient-derived iPSCs faithfully represent the genetic diversity and cellular architecture of human acute myeloid leukemia

Abstract The reprogramming of malignant cells to pluripotency has presented considerable challenges, hindering the application of induced pluripotent stem cell (iPSC) modeling technology to human cancers. In addition, how well iPSC-derived cells resemble their primary counterparts is currently largely unknown. We developed a reprogramming method tailored to human malignancies, “Complete Capture of Mutational Burden” (CCoMB), that combines comprehensive genetic characterization of the starting sample and inference of its clonal architecture with large-scale screening of clonally reprogrammed colonies. Using this method we were able to generate a panel of iPSC lines representing all major genetic groups of acute myeloid leukemia (AML). Specifically, we derived iPSC lines from 15 patients representing all major genetic groups of AML - PML-RARA; chromatin-spliceosome; TP53-mutated/aneuploidy; AML1-ETO, MLL-rearranged; NPM1-mutated and others - collectively capturing 21 distinct genotypes and 24 driver genetic lesions (mutations, translocations, deletions). Matched normal iPSCs were derived from 7 of these patients. Reprogramming to iPSCs captured both preleukemic (CH/initiating mutation only) and fully leukemic clones (baring the full set of patient mutations). In almost all cases, reprogramming informed reconstruction of the evolutionary hierarchy of the AML, with unexpected hierarchies unveiled in 4 of the cases. These AML-iPSCs retain genetic fidelity and, upon in vitro hematopoietic differentiation, produce hematopoietic cells with hallmark phenotypic leukemic features, including serial engraftment of a lethal myeloid leukemia into immunocompromised mice and extended self-renewal in vitro. Transplantation of cells derived from iPSCs representing two distinct AML clones from each of 3 patients revealed that these mimic the clonal dynamics in the patients, with more advanced clones showing increased representation in the xenografts, compared to the earlier clones. To compare the iPSC-derived to the primary leukemias, we performed single-cell transcriptomics analyses in patient-matched iPSC-derived and primary leukemic cells from 3 patients, both ex vivo/in vitro and after transplantation into NSGS mice. Clustering analyses identified cell types corresponding to primitive hematopoietic stem cell (HSC)/multipotent progenitor (MPP), hematopoietic progenitor cells (HPCs) and more mature myelomonocytic lineage cells in all samples from all patients, at varying frequencies. Leukemias derived through in vitro differentiation from iPSC lines exhibited both similarities, as well as differences, in their cellular composition and transcriptome, compared to the patient-matched ex vivo leukemias. However, upon transplantation of the same leukemias into NSGS mice, iPSC-derived xenografts were strikingly similar to the patient-derived xenografts. iPSC-derived leukemic cells exhibited a more stem/progenitor cell phenotype in vitro, with progressive maturation along the myeloid lineage upon primary and, even more, upon secondary transplantation, mimicking primary xenografts. In summary, our results reveal very few true biological barriers to the reprogramming of AML cells and show that AML-iPSC-derived leukemias faithfully mimic the primary patient leukemias upon xenotransplantation. Citation Format: Andriana Kotini, Saul Carcamo, Nataly Cruz-Rodriguez, Malgorzata Olszewska, Dan Hasson, Eirini Papapetrou. Patient-derived iPSCs faithfully represent the genetic diversity and cellular architecture of human acute myeloid leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB363.

Analytical solutions for Bloch waves in resonant phononic crystals: deep-subwavelength energy splitting and mode steering between topologically protected interfacial and edge states

Summary We derive analytical solutions based on singular Green’s functions, which enable efficient computations of scattering simulations or Floquet–Bloch dispersion relations for waves propagating through an elastic plate, whose surface is patterned by periodic arrays of elastic beams. Our methodology is versatile and allows us to solve a range of problems regarding arrangements of multiple beams per primitive cell, over Bragg to deep-subwavelength scales; we cross-verify against finite element numerical simulations to gain further confidence in our approach, which relies upon the hypothesis of Euler–Bernoulli beam theory considerably simplifying continuity conditions such that each beam can be replaced by point forces and moments applied to the neutral plane of the plate. The representations of Green’s functions by Fourier series or Fourier transforms readily follows, yielding rapid and accurate analytical schemes. The accuracy and flexibility of our solutions are demonstrated by engineering topologically non-trivial states, from primitive cells with broken spatial symmetries, following the phononic analogue of the Quantum Valley Hall Effect. Topologically protected states are produced and coexist along: interfaces between adjoining chiral-mirrored bulk media, and edges between one such chiral bulk and the surrounding bare elastic plate, allowing topological circuits to be designed with robust waveguiding. Our topologically protected interfacial states correspond to zero-line modes, and our topological edgestates are produced in accordance with the bulk-edge correspondence. These topologically non-trivial states exist within near flexural resonances of the constituent beams of the phononic crystal and hence can be tuned into a deep-subwavelength regime.