bluuebunny/crossref_metadata_2025 huggingface dataset:
L
P
-solutions to the ES-BGK model of the polyatomic molecules
Authors: Son Sung-Jun
Published: October 2024

The ellipsoidal-Bhatnagar, Gross, and Krook (ES-BGK) model is introduced as a generalized version of the original BGK model with the aim of calculating the correct Prandtl number, which is the ratio between viscosity and thermal conductivity. In this paper, we study the existence and uniqueness of Lp-solutions to the ES-BGK model for the polyatomic molecules, within the range 1 ≤ p ≤ ∞. This research aims to provide a comprehensive analysis in pursuit of a better understanding of the behavior of these systems.
Low-temperature photoluminescence and Raman study of monolayer WSe2 for photocarrier dynamics and thermal conductivity
Authors: Rai Suyash , Srivastava Anchal
Published: October 2024

Low-temperature PL analysis reveals an intriguing temperature-dependent emission pattern in WSe2: excitonic dominance above the 150 K Debye temperature, a balance between excitonic and trionic emissions at 150 K, and trionic dominance below this threshold. At lower temperatures, both excitons and trions display linearly polarized emissions, with polarization increasing from 0% at 300 K to 23% (excitons) and 7% (trions) at 150 K, and 12% for trions at 90 K. Moreover, the synthesized monolayer of WSe2 exhibits high thermal conductivity (246 W m−1 K−1 for A1g and 185 W m−1 K−1 for E2g1 modes). This property is attributed to Se vacancies and defects at triangle edges, which redirect phonons, reducing scattering and enabling efficient heat transport along boundaries. The unveiling of these novel insights within the synthesized 2D WSe2 material holds significant promise for its potential applications in nano-optoelectronics. Its demonstrated efficiency in dissipating heat, coupled with improved thermal stability, suggests the possibility of employing it in future devices. This could facilitate compact designs and the miniaturization of advanced technological tools, showcasing the material's potential for practical implementation.
Effects of W alloying on the electronic structure, phase stability, and thermoelectric power factor in epitaxial CrN thin films
Authors: Singh Niraj Kumar , Hjort Victor , Honnali Sanath Kumar , Gambino Davide , le Febvrier Arnaud , Ramanath Ganpati , Alling Björn , Eklund Per
Published: October 2024

CrN-based alloy thin films are of interest as thermoelectric materials for energy harvesting. Ab initio calculations show that dilute alloying of CrN with 3 at. % W substituting Cr induce flat electronic bands and push the Fermi level EF into the conduction band while retaining dispersive Cr 3d bands. These features are conducive for both high electrical conductivity σ and high Seebeck coefficient α and, hence, a high thermoelectric power factor α2σ. To investigate this possibility, epitaxial CrWxNz films were grown on c-sapphire by dc-magnetron sputtering. However, even films with the lowest W content (x = 0.03) in our study contained metallic h-Cr2N, which is not conducive for a high α. Nevertheless, the films exhibit a sizeable power factor of α2σ ∼ 4.7 × 10−4 W m−1 K−2 due to high σ ∼ 700 S cm−1, and a moderate α ∼ − 25 μV/K. Increasing h-Cr2N fractions in the 0.03 < x ≤ 0.19 range monotonically increases σ, but severely diminishes α leading to two orders of magnitude decrease in α2σ. This trend continues with x > 0.19 due to W precipitation. These findings indicate that dilute W additions below its solubility limit in CrN are important for realizing a high thermoelectric power factor in CrWxNz films.
Modulation of the vibrational and optical properties in β copper phthalocyanine under compression
Authors: Du Miaomiao , Wang Shengyi , Fu Shengchun , Zhang Junkai
Published: October 2024

Because copper phthalocyanine (CuPc) has significant uses in industrial devices and pigments, it is a subject of great interest in basic scientific research. Studying and adjusting its photoelectric qualities, in particular, has drawn much attention. In this work, in situ high-pressure experiments were used to investigate in detail the vibrational and optical properties of ground-state β-CuPc up to 13 GPa. Both micro-Raman and ultraviolet and visible light (UV–vis) absorption measurements revealed a phase transition occurring around 3 GPa. Notably, the macrocycle breathing vibration was found to have a remarkable characteristic of first weakening and then strengthening in response to this pressure-induced phase transition. The UV–vis absorption data revealed that the bandgaps corresponding to the two absorption edges decrease gradually with increasing pressure, with one edge disappearing entirely above 11 GPa. Furthermore, the blue β-CuPc can be adjusted to dark green at 10 GPa and ultimately entirely black due to the merging of its absorption bands and redshifts at high pressure. This work improves our understanding of CuPc's intrinsic characteristics under harsh settings and manipulates its color effectively.
Water compression induced ionic negative differential resistance in nanopores
Authors: Tan Haojing , He Zhi , Zhou Ruhong , Feng Jiandong
Published: October 2024

The mass transport behavior through nanoscale channels, greatly influenced by the structures and dynamics of nanoconfined water, plays an essential role in many biophysical processes. However, the dynamics of nanoconfined water under an external field and its effects are still not fully understood. Here, on the basis of molecular dynamics simulations, we theoretically show that the ionic current of [Bmim][PF6] through narrow pores in graphene membrane exhibits an ionic negative differential resistance effect—the ionic current decreases as the voltage increases over a certain threshold. This effect arises from the violation of traditional fluid dynamics as the assumption of continuity and homogeneity of fluids is no longer effective in ultrathin nanopores. The gradient of electric field around the atomic-thin layer produces a strong gradient force on the polarized water inside the nanopore. This dielectrophoretically compressed water leads to a hydrostatic force that repels ions from entering the nanopore. Our findings may advance the understanding of hydrostatic mechanism, which governs ion transport through nanopores.
All-electron first-principles GWΓ simulations for accurately predicting core-electron binding energies considering first-order three-point vertex corrections
Authors: Yoneyama Kenta , Noguchi Yoshifumi , Ohno Kaoru
Published: October 2024

In the conventional GW method, the three-point vertex function (Γ) is approximated to unity (Γ ∼ 1). Here, we developed an all-electron first-principles GWΓ method beyond a conventional GW method by considering a first-order three-point vertex function (Γ(1) = 1 + iGGW) in a one-electron self-energy operator. We applied the GWΓ method to simulate the binding energies (BEs) of B1s, C1s, N1s, O1s, and F1s for 19 small-sized molecules. Contrary to the one-shot GW method [or G0W0(LDA)], which underestimates the experimentally determined absolute BEs by about 3.7 eV for B1s, 5.1 eV for C1s, 6.9 eV for N1s, 7.8 eV for O1s, and 5.8 eV for F1s, the GWΓ method successfully reduces these errors by approximately 1–2 eV for all the elements studied here. Notably, the first-order three-point vertex corrections are more significant for heavier elements, following the order of F > O > N > C > B1s. Finally, the computational cost analysis revealed that one term in the GWΓ one-electron self-energy operator, despite being computationally intensive, contributes negligibly (<0.1 eV) to the C1s, N1s, O1s, and F1s.
Progress in theory and simulations of lattice Boltzmann method for heat transfer enhancement on phase change
Authors: Sun Y. L. , Yan Ting , Pan W. G. , Wang L. W.
Published: October 2024

As a general phenomenon in science and engineering, phase change has appeared and been applied in many aspects. However, there is a sufficient necessity to enhance the heat transfer in the phase change process due to the low heat transfer efficiency of the phase change material. In order to improve the efficiency of heat transfer during the phase change process, theory and numerical simulations based on computational fluid dynamics, especially the lattice Boltzmann (LB) method, are reviewed. The LB method has become a strong numerical method for heat and mass transfer and fluid dynamics because of its mesoscopic nature and a series of unique merits brought by this nature. In this article, progress in theory and simulations of the LB method for heat transfer enhancement on phase change is reviewed. This review first introduces the basic theories and models of the LB method for flow field and temperature field. Afterward, the development of the LB models for tracing the phase interface is reviewed. The application of the LB method for phase change and investigations of the heat transfer enhancement in the phase change process are also discussed. Finally, future developments in the LB method for phase change problems are prospected.
Hierarchical nested riblet surface for higher drag reduction in turbulent boundary layer
Authors: Ou Zhaoyang , Zhou Zidan , Zhou Wenyuan , Wang Daoyuan , Zhang Kun , Kong Zeyu , Tang Yalin , He Yang , Yuan Weizheng
Published: October 2024

Riblets can be potentially employed to passively reduce the turbulent friction drag. However, the drag reduction performance of riblets does not currently meet expectations, which could assist in emission reduction and energy conservation in green transportation. This study proposes and validates a topological form of hierarchical nested riblets (HNR) that significantly enhances the drag reduction performance. To explore the drag reduction enhancement mechanism, direct numerical simulations are performed for flow simulation on the riblet surface under different Reynolds numbers. The results show that under the riblet dimensionless spacing of the riblet s+≈21, the drag reduction performance of the HNR surface improves by about 70% compared to that of the uniform riblet surface, which is inspired by shark skin. From the perspective of turbulence statistics, the HNR surface reduces the turbulent mixing near the wall, weakening the momentum transfer. Furthermore, the transient flow field shows that the secondary riblet in HNR prevents some turbulent flow and streamwise vortices from entering the groove, considerably weakening the dispersive stress induced by the secondary flow. Moreover, owing to the influence of the secondary riblet, small-scale turbulence develops and strengthens into large-scale turbulent motion, which is advantageous to the boundary layer flow and results in drag reduction improvement.
Near-infrared–terahertz hyper-Raman spectroscopy of an excited silicon surface
Authors: Dalstein L. , Tondusson M. , Kristensen M. H. , Abraham E. , Degert J. , Freysz E.
Published: October 2024

We recorded the hyper-Raman spectra resulting from the interaction of a near-infrared (near-IR) picosecond pulse and a terahertz (THz) ultrashort pulse at the surface of a (111) silicon sample. A simple model is proposed to analyze the evolution of the hyper-Raman spectra vs the time delay between the near-IR and THz pulses. It links the hyper-Raman spectra to the multi-phonon absorption in silicon. This approach makes it possible to demonstrate that, during carrier generation by the near-IR pulse, the two-phonon and three-phonon absorption bands are enhanced in modes involving optical phonons. This process results from the very rapid and strong population of the optical phonons induced by the photo-generated hot carriers. It occurs over a few hundreds of femtoseconds and lasts throughout the duration of the near-IR pulse.
Numerical study on cavitation generation induced by the high-speed jet impact on the water surface
Authors: Dong Fangmian , Lyu Jie-Yao , Zhang Meng , Zhou Shuai
Published: October 2024

The complex interaction between shock waves and two-phase interfaces can generate cavitation. In this study, the cavitation induced by the high-speed jet impact on the water surface was investigated. The mixture fluid is modeled using the barotropic equation of state under the framework of the two-phase flow model, which can describe the mixture of air, water, and vapor with any proportion. Through constructing a 1D Riemann problem for the impact-induced cavitation phase transition, it indicates that the coupling effect of multiple rarefaction waves emitted from the two-phase interface is responsible for the cavitation phase transition inside the liquid. Then, a 3D (three-dimensional) simulation regarding the impact of a high-speed jet on the water surface was conducted and validated against previous experiments that captured the cavitation phase transition phenomenon in the central region after the jet impact. The 3D simulation results revealed the spatial structure and development process of shock waves in detail. The coupling effects of shock waves and two-phase interfaces generate a ring-shaped rarefaction wave, which develops radially inward and superimposes, resulting in the formation of acorn-shaped cavitation bubble nuclei inside the water. The 3D simulation can provide spatial shock/rarefaction wave structures and internal flow details that have never been obtained in experiments, such as shock generation and propagation, rarefaction wave generation and center convergence, and the internal structure of acorn-shaped cavitation nucleation. Furthermore, the influence of the jet velocity on the cavitation intensity was analyzed, and a quantitative relationship was provided.
Conformal SnO2 and NiOx charge transport layers for pragmatic air-processed perovskite solar cells
Authors: Zhu Huayi , Xi Zhiyuan , Cui Yuchen , Li Ming , Yuan Yan , Zhang Jianhui
Published: October 2024

The industrialization of perovskite (PVK) solar cells (PSCs) necessitates simple manufacturing, cheapness, nontoxicity, high efficiency, and stability. We report an air-processed lead halide PSCs with cheap, nontoxic, stable NiOx and SnO2 as the hole and electron transport layers separately, to meet all the above commercial requests. By preparing the NiOx (water-dispersible) and SnO2 (oil-dispersible) quantum dots (QDs) with good conductivity and energy band matched well with that of PVK, we fabricate inverted PSCs (ITO/NiOx/PVK/SnO2/Ag) with efficiency up to 20.1/14.6% for active areas of 0.0707/1 cm2, under 1 sun simulated illumination with enhanced UV light ratio. The UV-light resistant PSCs reported here will impel their application in the high altitude areas with strong UV light. Importantly, the monodisperse size and dominant (110) plane of SnO2 QDs achieved by controlling the solvothermal parameters, realize the conformal deposition and defect prevention of SnO2, respectively, thus improving the PSC efficiency and stability.
Epitaxial growth of GaN on β-Ga2O3 via RF plasma nitridation
Authors: Kelly Frank P. , Landi Matthew M. , Vesto Riley E. , Tadjer Marko J. , Hobart Karl D. , Kim Kyekyoon
Published: October 2024

The lack of suitable p-type dopant for β-Ga2O3 remains a hurdle for vertical power device applications. Epitaxy of GaN on Ga2O3 substrates was demonstrated as an alternative. (–201)-oriented β-Ga2O3 was converted into (0001)-oriented hexagonal GaN via nitrogen plasma in a plasma-assisted molecular beam epitaxy chamber, as verified by XRD and RHEED. The resulting nitridated GaN layers were characterized by TEM, x-ray reflectivity, and AFM to relate the nitridation conditions to crystallinity, layer thickness, and surface roughness. The crystallinity of subsequently grown epitaxial GaN films was quantified via XRD rocking curves and related to the nitridation layer properties across varying nitridation conditions. Specifically, the effect of the grain size and nitridation layer thickness was investigated to determine their role in threading screw dislocation management.
First-principles molecular dynamics of exciton-driven initial stage of plasma phase transition in warm dense molecular nitrogen
Authors: Fedorov Ilya D. , Stegailov Vladimir V.
Published: October 2024

Understanding the properties of molecular nitrogen N2 at extreme conditions is the fundamental problem for atomistic theory and the important benchmark for the capabilities of first-principles molecular dynamics (FPMD) methods. In this work, we focus on the connection between the dynamics of ions and electronic excitations in warm dense N2. The restricted open-shell Kohn–Sham method gives us the possibility to reach relevant time and length scales for FPMD modeling of an isolated exciton dynamics in warm dense N2. Wannier localization sheds light on the corresponding mechanisms of covalent bond network rearrangements that stand behind polymerization kinetics. FPMD results suggest a concept of energy transfer from the thermal energy of ions into the internal energy of polymeric structures that form in warm dense N2 at extreme conditions. Our findings agree with the thermobaric conditions for the onset of absorption in the optical spectroscopy study of Jiang et al. [Nat. Commun. 9, 2624 (2018)].
Sub-20 kHz low-frequency noise near ultraviolet butt-coupled fiber Bragg grating external cavity laser diode
Authors: Kervazo R. , Perin G. , Congar A. , Lablonde L. , Butté R. , Grandjean N. , Bodiou L. , Charrier J. , Trebaol S.
Published: October 2024

We present a butt-coupled InGaN fiber Bragg grating (FBG) semiconductor laser diode operating below 400 nm in the single-mode emission regime. This compact coherent laser source exhibits an intrinsic linewidth of 14 kHz in the near-UV range and a side-mode suppression ratio reaching up to 40 dB accompanied by almost 2 mW output power. Furthermore, the properties of the FBG, including its central wavelength, bandwidth, and reflectivity, can be readily customized to fulfill specific requirements. As a result, the small footprint design of this laser is compatible with integration into a standard butterfly package to ease the lab-to-market technology transfer. The combination of low-frequency noise and fibered output signal positions these FBG laser systems as strong candidates for hybridization with integrated photonic platforms tailored for quantum information processing and metrology.
Effect of locally excited state on fluorescence transition dipole moment in quadrupolar molecules subjected to symmetry breaking charge transfer
Authors: Mikhailova Tatyana V. , Mikhailova Valentina A. , Ivanov Anatoly I.
Published: October 2024

In excited centrosymmetric donor–acceptor triads of type A–D–A or D–A–D, symmetry breaking charge transfer (SBCT) in polar media has been explored for a few decades. SBCT is accompanied by significant reorganization of the electronic structure of the molecule, which leads to a change in the fluorescence transition dipole moment (TDM). Previously, experiments revealed a 20%–30% reduction in TDM, which occurs on the timescale of SBCT. Simple SBCT models explain this reduction. Here, the effect of the interaction of a locally excited state with zwitterionic states on TDM is investigated. This interaction is shown to have a drastic impact on the TDM and its dependence on the solvent polarity. The magnitude of TDM can decrease monotonically, increase monotonically, and also pass through a maximum with an increase in the SBCT degree due to the locally excited state effect. The scale of changes in TDM in the course of SBCT increases greatly. The conditions for the implementation of a particular scenario have been determined. This work clearly demonstrates the observable influence of upper excited states on the photochemistry and photophysics of molecules. Methods for controlling the fluorescent characteristics of quadrupolar molecules are proposed.
UBR-5 and UBE2D mediate timely exit from stem fate via destabilization of poly(A)-binding protein PABP-2 in cell state transition
Authors: Calva Moreno Jose Francisco , Jose George , Weaver Yi M. , Weaver Benjamin P.
Published: October 2024

UBR5 E3 ligase has been associated with cancer susceptibility and neuronal integrity, with functions in chromatin regulation and proteostasis. However, the functions of
ubr5
within animals remain unclear due to lethality in both mammals and flies when disrupted. Using
Caenorhabditis elegans
, we show that UBR-5 E3 ligase is required for timely exit of stem fate and complete transition into multiple cell type descendants in an ectodermal blast lineage. Animals lacking intact UBR-5 function simultaneously exhibit both stem fate and differentiated fate in the same descendant cells. A functional screen of UBR-5 physical interactors allowed us to identify the UBE2D2/3 E2 conjugase LET-70 working with UBR-5 to exit stem fate. Strikingly, we revealed that another UBR-5 physical interactor, namely the nuclear poly(A)-binding protein PABPN1 ortholog PABP-2, worked antagonistically to UBR-5 and LET-70. Lowering
pabp-2
levels restored normal transition of cell state out of stemness and promoted normal cell fusion when either
ubr-5
or
let-70
UBE2D function was compromised. The UBR-5-LET-70 and PABP-2 switch works independently of the stem pool size determined by pluripotency factors like
lin-28.
UBR-5 limits PABP-2 protein and reverses the PABP-2-dependent gene expression program including developmental, proteostasis, and innate immunity genes. Loss of
ubr-5
rescues the developmental stall when
pabp-2
is compromised. Disruption of
ubr-5
elevates PABP-2 levels and prolongs expression of ectodermal and muscle stem markers at the transition to adulthood. Additionally,
ubr-5
mutants exhibit an extended period of motility during aging and suppress
pabp-2-
dependent early onset of immobility.
Interwoven processes in linguistic historiography
Authors: Klöter Henning
Published: October 2024

This article presents an integrated perspective on the history of Chinese linguistics in Europe by examining the
interplay of logistic, material, and institutional factors. Asking how knowledge related to the Chinese language was obtained,
diffused, and preserved, it examines linguistic historiography through the prism of accessibility to China and its resulting
corollaries for formulating and testing hypotheses about the Chinese language. The nineteenth century is seen as a time of
professionalisation characterized by increased opportunities for engagement with China and its language, the creation of academic
positions and teaching programs, technical advances in digraphic printing, and the return of competent speakers of the Chinese
language.
Stochastic force generation in an isometric binary mechanical system
Authors: Murthy Vidya , Baker Josh E.
Published: October 2024

Accurate models of muscle contraction are necessary for understanding muscle performance and the molecular modifications that enhance it (e.g., therapeutics, posttranslational modifications, etc.). As a thermal system containing millions of randomly fluctuating atoms that on the thermal scale of a muscle fiber generate unidirectional force and power output, muscle mechanics are constrained by the laws of thermodynamics. According to a thermodynamic muscle model, muscle’s power stroke occurs with the shortening of an entropic spring consisting of an ensemble of force-generating myosin motor switches, each induced by actin binding and gated by inorganic phosphate release. This model differs fundamentally from conventional molecular power stroke models that assign springs to myosin motors in that it is physically impossible to describe an entropic spring in terms of the springs of its molecular constituents. A simple two-state thermodynamic model (a binary mechanical system) accurately accounts for muscle force–velocity relationships, force transients following rapid mechanical and chemical perturbations, and a thermodynamic work loop. Because this model transforms our understanding of muscle contraction, it must continue to be tested. Here, we show that a simple stochastic kinetic simulation of isometric muscle force predicts four phases of a force-generating loop that bifurcates between periodic and stochastic beating through mechanisms framed by two thermodynamic equations. We compare these model predictions with experimental data including observations of spontaneous oscillatory contractions (SPOCs) in muscles and periodic force generation in small myosin ensembles.
Gravitational spinoptics in a curved space-time
Authors: Frolov Valeri P. , Shoom Andrey A.
Published: October 2024

In this paper we discuss propagation of the weak high-frequency gravitational waves in a curved spacetime background. We develop a so-called spinoptics approximation which takes into account interaction of the spin of the field with the curvature of the background metric. This is achieved by modifying the standard geometric optics approximation by including the helicity sensitive terms of the order 1/ω in the eikonal equation. The novelty of the approach developed in this paper is that instead of study of the high-frequency expansion of the equations for the gravitational field perturbations we construct the effective action for the gravitational spinoptics. The gravitational spinoptics equations derived by variation of the effective action correctly reproduce the earlier obtained results. However, the proposed effective action approach is technically more simple and transparent.
It allows one to reduce the study of the high-frequency gravitational waves to study classical dynamics of massless particles with internal discrete degree of freedom (helicity). The formalism is covariant and it can be applied for arbitrary vacuum space-time background.
Mitigation as Causation
Authors: Summers Andy
Published: October 2024

This chapter summarizes the new account of mitigation that is developed in subsequent chapters. First, it outlines how mitigation can be explained using the commonsense principles of causation identified in Chapter 5. Second, it restates the law of mitigation in terms of two rules: the ‘replication rule’ and the ‘exceptionality rule’, each of which reflect the causal significance of the claimant’s choice to depart from the normal response to breach. Third, it sketches briefly how the law of mitigation, so described, might be normatively justified. The final section of the chapter compares the new account of mitigation with the orthodox account outlined in Chapter 1, to clarify how the replication and exceptionality rules relate to and differ from the conventional understanding of the avoidable and avoided loss rules.
Avoidable Loss
Authors: Summers Andy
Published: October 2024

This chapter restates the law of mitigation as it applies to the cases conventionally discussed under the rubric of ‘avoidable loss’. First, it argues that the reasonableness test conceals two distinct rules: the replication rule and the exceptionality rule, as introduced in Chapter 6. It shows how these rules apply to the claimant’s attempts at repair, replacement, extrication, and post-breach negotiations with the defendant. Second, the chapter shows that the effect of the replication and exceptionality rules is that the claimant’s breach position is assessed counterfactually as if they had taken steps to replicate their no-breach position in the usual way. Where these rules do not apply, the claimant will recover for their factual loss. Finally, the chapter addresses the procedural issues of burden of proof and whether (and when) mitigation raises questions of fact or law.
Avoided Loss
Authors: Summers Andy
Published: October 2024

This chapter restates the law of mitigation as it applies to the cases conventionally discussed under the rubric of ‘avoided loss’. First, it argues that the British Westinghouse test for determining when benefits are taken into account in the assessment of damages reflects the application of the replication rule, as introduced in Chapter 6. Second, it shows that where this rule applies, loss is assessed on a counterfactual basis as if the claimant had taken steps to replicate, ignoring any benefits actually received as a result of not replicating. By contrast, where the replication rule does not apply, the claimant will only recover for their factual loss. Finally, the chapter discusses two other types of case which are also sometimes referred to as examples of recovery for ‘avoided loss’, but which are distinct from the replication rule.
MDM2 Testing In Lipomatous Tumors: An Institutional Experience with 1,161 Neoplasms
Authors: SOFOLA-JAMES O , KHAEFPANAH D , FADARE O
Published: October 2024

Introduction/Objective

Amplifications of the MDM2 gene is a well-recognized central molecular event in atypical lipomatous tumors, well-differentiated liposarcomas, and dedifferentiated liposarcomas. However, given the fact that most adipocytic neoplasms are benign, the specific testing approaches that will maximize the detection of MDM2 amplified tumors in an accurate and cost-efficient manner remains unclear. The purpose of this study is to present our experience with MDM2 testing by FISH in a large cohort of lipomatous neoplasms.

Methods/Case Report

The pathologic database of an academic medical center was queried for all lipomatous tumors as well as all tumors for which MDM2 testing was performed during a three-year period. At our center, MDM2 testing for well differentiated adipocytic neoplasms is triggered by the so-called “traditional criteria”: a deep tumor and/or tumor size >10 cm and/or recurrence. We also take an expanded approach for a variety of indications that may include equivocal atypia or clinical/imaging concern, among others. Testing is also performed on overt malignancies for which dedifferentiated liposarcoma is a plausible consideration after review of morphologic features.

Clinicopathologic data, including patient age of diagnosis, tumor size, depth of tumor, results from MDM2 testing [when performed], anatomic location(s) and recurrence [where applicable], were collected for each patient.

Results (if a Case Study enter NA)

1161 cases were assessed, 456 of whom underwent MDM2 testing, and 108 of which were ultimately classified as MDM2 amplified. Standardized bivariable comparisons found that a deep tumor location (p=0.0014) and older age (p=0.0002), but not tumor size at the >10 cm cut off were associated with MDM2 positivity. However, a logistic regression model showed that neither size, depth or age were significantly associated with MDM2 positivity. Among the MDM2-positive cohort, 91% had tumor sizes <10 cm, 14% were superficial, 23% were non-recurrent and 15% were less than the median cohort patient age of 58 years. If the aforementioned “traditional criteria” were used as the sole basis for MDM2 testing, 50 (46.29%) of the 108 cases that were ultimately classified as MDM2 positive would not have been tested.

Conclusion

Our findings suggest that a strict adherence to “traditional criteria” may result in a significant subset of MDM2 positive tumors not being tested in lipomatous tumors. A more expansive approach that incorporates additional indications for testing, should be evaluated.
Spatial transcriptomics of human and murine Neurofibromatosis Type I fracture pseudarthroses reveal impaired BMP signaling
Authors: Juan C , Shelton J M , Jeffery E C , Tower R J , Paria N , Oxendine I , Wassel M , Kidane Y , Cornelia R , Podeszwa D A , Wise C A , Rios J J , Conway S J
Published: October 2024

Introduction/Objective

In Neurofibromatosis Type 1 (NF1), caused by mutations in the NF1 tumor-suppressor gene, children form fibrotic nonunions known as pseudarthroses following long bone fractures. Here, we integrate spatial transcriptomics of human and murine samples to investigate the pathogenesis underlying pseudoarthrosis development.

Methods/Case Report

We performed spatial transcriptomics on 10-day post-fracture calluses from control and periosteum-specific Nf1-deficient (Nf1Postn) mice as well as a human NF1 patient pseudarthrosis specimen.

Differential gene expression and SpatialTime analyses were performed. BMP signaling was validated by immunohistochemical staining of tissues for phospho-SMAD1/5/8.

Results (if a Case Study enter NA)

Spatial transcriptomics detected eight cell clusters, including bone, cartilage, and muscle within mouse fracture calluses. In the control, clusters involved in fracture repair were enriched for genes associated with extracellular matrix and collagen formation (progenitor and cartilage clusters), cartilage and endochondral bone processes (ossifying perichondrium cluster), and bone remodeling (woven bone cluster).

Expression of TGF-beta pathway genes was highest near the fracture plane, while BMP and Wnt pathways were activated further from the fracture. In the Nf1Postn fracture, healing was significantly delayed, lacking a robust callus and with a lower abundance of reparative skeletal cell clusters. While expression of TGF-beta pathway genes was similar to control, BMP pathway expression was minimal within the Nf1Postn fracture, which was further demonstrated by a lack of phospho-SMAD1/5/8 staining. In the human pseudarthrosis, while TGF-beta pathway genes were expressed near the fracture plane as expected, there was no enrichment of BMP pathway expression in the pseudarthrosis tissue and no significant phospho-SMAD1/5/8 staining.

Conclusion

Spatial transcriptomics allows for the simultaneous unbiased analysis of multiple signal transduction pathways within their native tissue environment. Our analyses 1) revealed the cellular diversity required for fracture healing, 2) demonstrated the spatially-restricted expression of key morphogenetic pathways within a fracture callus, and 3) provides in situ evidence for impaired BMP pathway activation associated with NF1 fracture pseudarthroses.
Unveiling the Unusual: Mediastinal Rhabdomyosarcoma in an Adult Patient
Authors: almukhtar R , Aldahan M , Lonardo S
Published: October 2024

Introduction/Objective

We present a case of a 55-year-old female with a history of hypertension, diabetes, hyperlipidemia, chronic kidney disease (CKD), and asthma, who presented with a mediastinal mass.

Methods/Case Report

A needle core biopsy of the mediastinal mass was performed. Microscopic examination showed a proliferation of primitive appearing, moderately pleomorphic cells with features suggestive of rare strap cells of rhabdomyosarcoma. Immunohistochemical staining was positive for desmin and myogenin, consistent with rhabdomyosarcoma. Further cytogenetic analysis for FOXO1 translocation, was performed.

Results (if a Case Study enter NA)

Cytogenetic analysis was negative for FOXO1 translocation by FISH, ruling out alveolar rhabdomyosarcoma. Despite negative cytogenetic findings, the morphology and immunoprofile were consistent with rhabdomyosarcoma. However, the possibility of rhabdomyosarcoma occurring within a mediastinal teratoma, germ cell tumor, or carcinosarcoma was noted.

Conclusion

This case highlights the challenge of diagnosing rhabdomyosarcoma in adults, especially when presenting as a mediastinal mass. The histologic and immunophenotype supported the diagnosis of rhabdomyosarcoma. However understanding the primary of the lesion in the hilum is more diffecult. physical examination releave no lesion on the extremities. CT scan of the abdomen and pelvis reveals no other lesion. making the metastasis unlikely.This case underscores the importance of thorough diagnostic evaluation, including histopathology and immunohistochemistry, in the assessment of unusual neoplasms, which can impact treatment decisions and prognosis. Further studies are warranted to elucidate the molecular mechanisms underlying rhabdomyosarcoma in adults and its association with other mediastinal tumors. This case report contributes to the evolving understanding of rare malignancies and their implications for pathology and laboratory medicine practice.
PLASMA CELL NEOPLASM IN BREAST: A RARE CASE REPORT
Authors: Tripathi M , Shen P
Published: October 2024

Introduction/Objective

Breast carcinoma continues to be the most common malignancy in women however plasma cell neoplasms are rare in breast tissue. Most of these recorded cases are from patients with Multiple myeloma (1). We present a rare case of a new breast lesion in a 69 year female incidentally found on imaging. She had a history of adenocarcinoma of lung with brain metastasis undergoing treatment.

Methods/Case Report

The patient’s breast lesion presentation was unusual without any pain or associated symptoms, but a new right breast mass was incidentally discovered on CT-Chest Abdomen-Pelvis. Mammogram revealed a 1.4 cm circumscribed mass in lower, outer breast with scattered calcifications. With the suspicion for a primary breast malignancy or metastatic disease from her lung cancer the patient’s breast lesion was biopsied.

On histology, abnormal proliferation of cells with ovoid nuclei, vesicular chromatin and variable cytoplasm was noted with a background of mature adipose tissue.

Immunohistochemistry showed neoplastic cells positive for plasma cell associated markers including CD38 (patchy), CD56, CD138, and MUM1 with a kappa restriction on ISH. The Ki67 showed 20% proliferation index.

EBER was negative and SMARC4 and INI were preserved.

Other immunohistochemical stains were performed to rule out differentials and were all negative.

The morphology and IHCs were consistent with the diagnosis of Plasma cell neoplasm with kappa-restriction. Subsequently this patient developed a shoulder lesion which on biopsy showed a plasma cell neoplasm expressing plasma cell markers and kappa light chain overexpression.

Results (if a Case Study enter NA)

NA

Conclusion

It is critical to distinguish a breast plasma cell neoplasm from other primary and metastatic breast lesions in order to avoid unnecessary surgery and cytotoxic chemotherapy. Rarely, plasma cell neoplasm can manifests as a breast lesion, which in this case turned out to be the early manifestation of multiple myeloma.
MALIGNANT PHYLLODES TUMORS – A SINGLE HOSPITAL ANALYSIS
Authors: Taha H , Shitawi M , Abdelhammed M , McGowan L A , Dhamne S , Zhang S , Wang J
Published: October 2024

Introduction/Objective

Phyllodes tumor (PT), a rare fibroepithelial breast lesion, affects around 1% of breast tumors, primarily in women aged 40–50 years old. The interpretive subjectivity, histological overlap, and limited molecular predictors, necessitate further investigation into their pathogenesis. Prognosis relies on WHO grading based on stromal proliferation. Malignant-PTs are rare and challenging to diagnose, posing a diagnostic challenge with breast sarcomas and metaplastic carcinomas. The study aims to highlight morphological features of malignant-PTs and their correlation on patients’ survival and prognosis.

Methods/Case Report

Retrospective single-institute study of 33 women who were diagnosed with malignant-PT according to WHO criteria and underwent excision were identified from database spanning 2005-2024. Clinical and pathologic characteristics including biopsy results, histological features, imaging findings, and survival outcomes were analyzed statistically using Kaplan-Meier method.

Results (if a Case Study enter NA)

Patients aged 28-72 years underwent excision, with a mean of 50 years and tumor sizes ranging 1.1-34 cm with a mean of 11.5 cm. The majority (19 cases) were classified as pT stage I or II, with 14 cases at more advanced stages. Malignant heterologous elements were found in 10 cases (30%). Positive margins were noted in 12 excisions (36%). Besides tumor recurrence in 3 cases (9%) within 33 months post-excision, metastasis was observed in 8 cases, occurring between 4-60 months post-excision. Six patients died from metastasis within 11-62 months post-diagnosis.

Conclusion

The presence of negative margins and appropriate treatment was associated with a lower risk of recurrence and metastasis. However, they were not linked to enhance survival rates. Survival was primarily correlated to the absence of heterologous components and PT’s staging.
A Rare Case of Homozygous Hemoglobin G-Philadelphia & Alpha Thalassemia
Authors: Olaniyan H S , Ashraf N , Konger R L
Published: October 2024

Introduction/Objective

Hemoglobin (Hb) G-Philadelphia (GPh) is an alpha chain gene variant caused by a missense mutation resulting in a change from Glu to Asp at position 68. This change leads to alterations in the Hb structure and oxygen affinity. The mutation is inherited in an autosomal codominant pattern allowing for an asymptomatic carrier state. While the most common alpha chain variant, GPh heterozygosity is still infrequent, estimated at 1:5000 in African Americans. In African Americans, GPh is frequently linked to an alpha thalassemia deletion. On its own it is considered a benign variant that does not result in significant health issues. Homozygous HbGPh frequency is estimated at 1 in 25 million.

Methods/Case Report

A postpartum woman in her 4th decade of life was found to have a Hb of 10.8 and a mean corpuscular volume of 74. Initial work up included Hb electrophoresis that quantified HbA at 0%, Hb F at 0%, HbA2 at 0%, and 2 Hb variants representing 96.1% and 3.8% of the total globin. The major Hb variant migrated in the D or G position by alkaline and acid gel Hb electrophoresis. The minor variant was consistent with HbG2. Due to this abnormal Hb electrophoresis, a sample was sent out for a Hb evaluation reflexive cascade (HERC). HERC analysis by high-performance liquid chromatography and capillary gel electrophoresis found 99.9% of Hb consistent with the alpha chain variant HbG. Analysis of the alpha globin gene region revealed 2 copies of an alpha globin gene deletion that was interpreted as alpha-thal trait (-a/-a). This result is consistent with homozygous alpha-thal-2 and homozygous HbGPh (alpha^G/thal + alpha^G/thal).

Results (if a Case Study enter NA)

NA

Conclusion

Alpha^G/thal + alpha^G/thal presents a unique and complex challenge for diagnosis due to its rarity and because HbG2 is not always visualized by alkaline gel electrophoresis. The presence of a Hb G or D variant, a HbG2 variant, and the lack of both HbA and HbA2 are key electrophoretic findings. Clinically, alpha^G/thal + alpha^G/thal behaves essentially like a homozygous alpha-thal-2 trait with persistent microcytosis and erythrocytosis. Thus, co- inheritance of the alpha-thal trait will be suggested by a thalassemic complete blood count pattern.
CLASSIFICATION OF COLORECTAL CANCER PATIENTS BASED ON SERUM MICRONUTRIENTS: AN EXPLORATORY INVESTIGATION
Authors: Rongioletti M , Di Veroli L , Mastromoro G , Krishnamurthy H , Bosco J , Jayaraman V , Krishna K , Pal A , De Luca A , Squitti R , Rizzo G , Tondolo V
Published: October 2024

Introduction/Objective

Colorectal cancer (CRC) is a growing global health challenge with a multifactorial etiology encompassing genetic susceptibility, nutrition, and inflammation in the bowel. To examine micronutrient status in CRC patients undergoing CRC resection.

Methods/Case Report

We performed a pilot case-control study including 13 consecutive CRC patients and 10 healthy controls (CTRL) comparing the serum levels of 29 micronutrients, namely Copper, Zinc, Selenium, Chromium, Manganese, Carnitine, Choline, Inositol, Methylmalonic acid (MMA), Vitamin (Vit) B1, Vit B2, Vit B3, Vit B5, Vit B6, Vit C, Vit A, Vit D3, Vit E, Vit K1, Vit K2 and the amino acids Serine, Valine, Leucine, Isoleucine, Asparagine, Glutamine, Arginine, Citrulline and Cysteine. The analysis of trace metals (copper, zinc, selenium, chromium, manganese) in serum was done using the Inductively coupled plasma mass spectrometry (ICP-MS) methodology using the Agilent 8900 QQQ instrument. The analysis of serum water-soluble and fat-soluble vitamins and amino acids was conducted using the LC/MS (Xevo-TQ-XS) mass spectrometer (WBA0127). Elution of the fat-soluble vitamins was performed using a solid-phase extraction system with an OASIS Prime HLB plate containing 10 mg of sorbent per well, in a Waters vacuum manifold equipped with a waste collection plate. Comparison among continuous biological variables was carried out by multivariate ANOVA model (MANOVA), accounting for the effect of sex and age

Results (if a Case Study enter NA)

After considering the effect of age and sex, copper, arginine, and cysteine were increased, while zinc, selenium, chromium, Vit B1, Vit K1, and Vit A were decreased in CRC patients in comparison with CTRL. Zinc levels perfectly predicted the diagnosis of CRC, and was associated with lymph nodes (pN), of the pTNM staging. Copper levels in serum was strongly associated with the pathological pTNM staging of CRC.

Conclusion

Though this is a preliminary study which needs confirmation with a larger longitudinal cohort, our results show that serum micronutrients are linked to tumor growth, likely caused by increased demand from tumor tissue associated with an aberrant cell proliferation and changes in the antioxidant function.
Berberine-Loaded Bovine Serum Albumin Nanoparticles: Fabrication, Characterization, and Drug Release Evaluation
Authors: Abdelmonem M , Hemdan A , Ghareeb D , El demellawy M , Abdelmageed M , Wasim H , El sayed M
Published: October 2024

Introduction/Objective

Introduction: Numerous studies have highlighted the diverse biochemical and pharmacological properties of berberine (BER), including its anti-inflammatory, antioxidant, anticancer, and hypolipidemic effects. Nanoparticles play a crucial role in enhancing drug delivery by providing a larger surface area, facilitating quicker dissolution in the bloodstream.

Methods/Case Report

Methods: Blank bovine serum albumin nanoparticles (BSA NPs) were prepared using a desolvation process, followed by the fabrication of berberine-loaded BSA nanoparticles (BER-NP). Physicochemical characterization, including particle size and zeta potential, was conducted using a Malvern Zetasizer. The mean particle size and distribution were determined using photon correlation spectroscopy (PCS), and transmission electron microscope (TEM) images were obtained for visualization. Fourier transform infrared (FTIR) spectra and differential scanning calorimetry (DSC) thermograms were recorded to assess drug encapsulation efficiency (EE). Berberine release from BER-NPs was evaluated using dialysis membranes.

Results (if a Case Study enter NA)

Results: FTIR spectra and DSC thermograms confirmed successful drug loading into the nanoparticles. Encapsulation efficiency was determined by UV absorption spectroscopy, revealing high efficiency in the encapsulation process. Dialysis membranes demonstrated controlled release kinetics of berberine from BER-NPs, indicating their potential for targeted drug delivery.

Conclusion

Conclusion: Berberine-loaded bovine serum albumin nanoparticles exhibit favorable characteristics for drug delivery applications, including enhanced permeation across biological barriers. These nanoparticles hold promise for targeted therapy and combination drug regimens, offering potential benefits for various medical interventions.