bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of nozzle geometry and wall roughness effects on diesel injector flow
Authors: Zainab Saima , Syed Khalid Saifullah
Published: November 2023

The flow and design of fuel injector nozzles have a considerable influence on the spray and combustion characteristics of a diesel engine. In-cylinder combustion, atomization, and primary breakdown are all highly influenced by the cavitation and turbulence in the fuel injector nozzle. In this paper, the effect of the nozzle geometry parameters, wall roughness parameters, and pressure difference on the swirl number, mass flow rate, turbulent kinetic energy, and vapor volume fraction is explored. U-type nozzle hole geometry, a well-known benchmark for the injector nozzle flow, is used to evaluate mesh independence and model validation. Large-eddy simulations are performed to provide a precise presentation of the flow structures and turbulent eddies inside the nozzle. Multiphase flow is studied using the mixture model, whereas cavitation is studied using the Schnerr–Sauer model based on the Rayleigh–Plesset equation. We find that the wall roughness parameters have an exciting impact on the discharge coefficient, swirl number, and vapor volume fraction. Due to the non-monotonic dependence of nozzle flow characteristics on the pressure difference and the wall roughness parameters, we can always find such values of these input parameters that render optimal nozzle flow characteristics. In this way, these parameters provide good control of spray formation and consequently on the quality and rate of combustion in the diesel engine.
Mechanism and destruction status of CO2 BLEVE during CO2 geological storage and enhanced oil recovery injection process
Authors: Huo Lei , He Yawei , Ma Erping , Liu Xing
Published: November 2023

In CO2-oil recovery enhancement technology, the occurrence of a Boiling Liquid Expansion Vapor Explosion (BLEVE) can result in dangerous events that endanger the lives and health of workers, while also leading to significant economic losses. This happens when there is an excessive injection concentration and volume of CO2, coupled with container defects. To address the limited research on the mechanism and destruction of BLEVE, this study conducts experiments to explore these issues. The experimental results reveal that the bursting piece ruptures at a temperature of 36 °C, and the specimen explodes when the pressure intensity exceeds the residual strength of the specimen, reaching 69.97 MPa. The findings indicate that parameters, such as initial pressure, initial temperature, and failure pressure, can impact the risk of CO2 BLEVE occurrence and the propagation of explosion shock waves. The pressure inside the container during the BLEVE process fluctuates due to the joint action of the leakage rate and gasification rate of liquid CO2. This research provides a framework for evaluating the risk of CO2 BLEVE during CO2 geological storage and enhanced oil recovery injection processes, offering theoretical support for BLEVE prevention and control.
Heavy quark energy loss through polarization and radiation in the hot QCD medium
Authors: Prakash Jai , Yousuf Jamal Mohammad
Published: November 2023

We present a comparative study on the heavy quarks energy loss through medium polarization and gluon radiation in the quark-gluon plasma. To do so, we investigated the energy loss per unit length and drag coefficient for both cases. To have better contrast, we also obtained the nuclear modification factor employing Langevin dynamics. The comparison shows that the polarization effect dominates at lower momentum. The medium temperature also plays an important role in the comparison.
Self-matching extraction fractional wavelet transform for mechanical equipment fault diagnosis
Authors: Liu Yang , Dan Binbin , Yi Cancan , Huang Tao , Zhang Fuqi
Published: November 2023

Time-frequency analysis (TFA) of vibration signals is an important way for fault diagnosis and predictive maintenance of mechanical equipment. However, the existing TFA methods, such as wavelet transform (WT) and synchrosqueezing transform, are incapable to describe local details of strongly time-varying signals, bringing such problems as time-frequency energy dispersion. Theoretically, it is more beneficial for time-varying band-limited signals to make multi-resolution analysis in the time-fraction frequency domain because such action can increase the selection chances of mother wavelets in any direction on the time-frequency plane by changing the angle

α

. In order to improve the ability of analyzing strongly time-varying signals and the readability of the time-frequency plane, this paper has proposed a novel TFA method called self-matching extraction fractional WT (SMEFRWT). Firstly, within the theoretical framework of fractional WT (FRWT), a minimum entropy-based method is proposed to choose an optimal angle in the fractional domain. Such action can obtain the best aggregation angle of time-frequency energy and facilitate the separation of multi-component signals. Then, self-matching extraction operator, one instantaneous-frequency estimated operator that match the time-frequency structure of amplitude modulation signals, is constructed. The operator allows for the distribution of time-frequency energy of fast-changing signals in both frequency and time directions, making it possible to match the time-varying vibration signals from mechanical equipment more accurately. Finally, SMEFRWT is adopted to make TFA and extract fault features of the faulty experiment benches on gear and bearings, with its feasibility validated by experimental results.
Improving vertical GaN p–n diode performance with room temperature defect mitigation
Authors: Sultan Al-Mamun Nahid , Gallagher James , Jacobs Alan G , Hobart Karl D , Anderson Travis J , Gunning Brendan P , Kaplar Robert J , Wolfe Douglas E , Haque Aman
Published: November 2023

Defect mitigation of electronic devices is conventionally achieved using thermal annealing. To mobilize the defects, very high temperatures are necessary. Since thermal diffusion is random in nature, the process may take a prolonged period of time. In contrast, we demonstrate a room temperature annealing technique that takes only a few seconds. The fundamental mechanism is defect mobilization by atomic scale mechanical force originating from very high current density but low duty cycle electrical pulses. The high-energy electrons lose their momentum upon collision with the defects, yet the low duty cycle suppresses any heat accumulation to keep the temperature ambient. For a 7 × 105 A cm−2 pulsed current, we report an approximately 26% reduction in specific on-resistance, a 50% increase of the rectification ratio with a lower ideality factor, and reverse leakage current for as-fabricated vertical geometry GaN p–n diodes. We characterize the microscopic defect density of the devices before and after the room temperature processing to explain the improvement in the electrical characteristics. Raman analysis reveals an improvement in the crystallinity of the GaN layer and an approximately 40% relaxation of any post-fabrication residual strain compared to the as-received sample. Cross-sectional transmission electron microscopy (TEM) images and geometric phase analysis results of high-resolution TEM images further confirm the effectiveness of the proposed room temperature annealing technique to mitigate defects in the device. No detrimental effect, such as diffusion and/or segregation of elements, is observed as a result of applying a high-density pulsed current, as confirmed by energy dispersive x-ray spectroscopy mapping.
Development of a monochromatic crystal backlight imager for the recent double-cone ignition experiments
Authors: Zhang 张 Chenglong 成龙 , Zhang 张 Yihang 翌航 , Yuan 远 Xiaohui 晓辉 , Zhang 张 Zhe 喆 , Xu 徐 Miaohua 妙华 , Dai 戴 Yu 羽 , Dong 董 Yufeng 玉峰 , Gu 谷 Haochen 昊琛 , Liu 刘 Zhengdong 正东 , Zhao 赵 Xu 旭 , Li 李 Yutong 玉同 , Li 李 Yingjun 英骏 , Zhu 朱 Jianqiang 健强 , Zhang 张 Jie 杰
Published: November 2023

We developed a monochromatic crystal backlight imaging system for the double-cone ignition (DCI) scheme, employing a spherically bent quartz crystal. This system was used to measure the spatial distribution and temporal evolution of the head-on colliding plasma from the two compressing cones in the DCI experiments. The influence of laser parameters on the x-ray backlighter intensity and spatial resolution of the imaging system was investigated. The imaging system had a spatial resolution of 10 μm when employing a CCD detector. Experiments demonstrated that the system can obtain time-resolved radiographic images with high quality, enabling the precise measurement of the shape, size, and density distribution of the plasma.
Effect of granular shape on radial segregation in a two-dimensional drum
Authors: Xu 徐 Yue 悦 , Li 李 Ran 然 , Chi 迟 Zhipeng 志鹏 , Xiu 修 Wenzheng 文正 , Sun 孙 Qicheng 其诚 , Yang 杨 Hui 晖
Published: November 2023

Granular segregation is widely observed in nature and industry. Most research has focused on segregation caused by differences in the size and density of spherical grains. However, due to the fact that grains typically have different shapes, the focus is shifting towards shape segregation. In this study, experiments are conducted by mixing cubic and spherical grains. The results indicate that spherical grains gather at the center and cubic grains are distributed around them, and the degree of segregation is low. Through experiments, a structured analysis of local regions is conducted to explain the inability to form stable segregation patterns with obviously different geometric shapes. Further, through simulations, the reasons for the central and peripheral distributions are explained by comparing velocities and the number of collisions of the grains in the flow layer.
Waveguide-integrated optical modulators with two-dimensional materials
Authors: Chen Haitao , Cao Hongyuan , Yu Zejie , Zhao Weike , Dai Daoxin
Published: November 2023

Waveguide-integrated optical modulators are indispensable for on-chip optical interconnects and optical computing. To cope with the ever-increasing amount of data being generated and consumed, ultrafast waveguide-integrated optical modulators with low energy consumption are highly demanded. In recent years, two-dimensional (2D) materials have attracted a lot of attention and have provided tremendous opportunities for the development of high-performance waveguide-integrated optical modulators because of their extraordinary optoelectronic properties and versatile compatibility. This paper reviews the state-of-the-art waveguide-integrated optical modulators with 2D materials, providing researchers with the developing trends in the field and allowing them to identify existing challenges and promising potential solutions. First, the concept and fundamental mechanisms of optical modulation with 2D materials are summarized. Second, a review of waveguide-integrated optical modulators employing electro-optic, all-optic, and thermo-optic effects is provided. Finally, the challenges and perspectives of waveguide-integrated modulators with 2D materials are discussed.
Performance optimization of tri-gate junctionless FinFET using channel stack engineering for digital and analog/RF design
Authors: Singh Devenderpal , Chaudhary Shalini , Dewan Basudha , Yadav Menka
Published: November 2023

This manuscript explores the behavior of a junctionless tri-gate FinFET at the nano-scale region using SiGe material for the channel. For the analysis, three different channel structures are used: (a) tri-layer stack channel (TLSC) (Si–SiGe–Si), (b) double layer stack channel (DLSC) (SiGe–Si), (c) single layer channel (SLC) (Si). The I−V characteristics, subthreshold swing (SS), drain-induced barrier lowering (DIBL), threshold voltage (V
t), drain current (I
ON), OFF current (I
OFF), and ON-OFF current ratio (I
ON/I
OFF) are observed for the structures at a 20 nm gate length. It is seen that TLSC provides 21.3% and 14.3% more ON current than DLSC and SLC, respectively. The paper also explores the analog and RF factors such as input transconductance (g
m), output transconductance (g
ds), gain (g
m/g
ds), transconductance generation factor (TGF), cut-off frequency (f
T), maximum oscillation frequency (f
max), gain frequency product (GFP) and linearity performance parameters such as second and third-order harmonics (g
m2, g
m3), voltage intercept points (VIP2, VIP3) and 1-dB compression points for the three structures. The results show that the TLSC has a high analog performance due to more g
m and provides 16.3%, 48.4% more gain than SLC and DLSC, respectively and it also provides better linearity. All the results are obtained using the VisualTCAD tool.
Design and simulation of modified 3D-trench electrode sensors
Authors: Ye Jixing , Loi Angelo , Lai Adriano , Dalla Betta Gian-Franco
Published: November 2023

Future experiments at high-luminosity hadron colliders will involve unprecedent levels of
pile up, calling for ultrafast detectors in order to add time information to distinguish between
particle tracks. The unique geometry of 3D sensors enables to achieve very good timing
performance, with the additional benefit of high radiation hardness. Remarkable results in terms
of temporal resolution have been reported for 3D sensors with columnar electrodes (∼30 ps)
and even better with trenched electrodes (∼10 ps), because of a more uniform distribution of
the electric field and weighting field. However, 3D-trench technology is more complex, and has
still to be optimized in terms of both fabrication process and pixel layout. To this purpose, as
an alternative to the existing design which features continuous (p+) ohmic trenches, we propose
a new variant by introducing a gap (∼10 μm) in the p+ trenches and placed offset
with respect to the readout (n+) trenches, so as to reduce the risk of lithographical defects
that were observed in mm's long ohmic trenches, thus improving the fabrication yield.

TCAD simulations confirmed that the impact of the gap on the uniformity of the electric and weighting field is minimum, and good charge collection efficiency performance is preserved up to large fluences. Further Monte Carlo time-resolved simulations are performed on both the standard and modified geometries showing comparable temporal resolutions.
The link between intertropical convergence zone stagnation and bias in local shortwave cloud radiative forcing over tropical Africa in climate models
Authors: Dombo Tomviezibe C , AchutaRao Krishna M , Sandeep S
Published: November 2023

The northward migration of the intertropical convergence zone (ITCZ) is a significant feature of the West African (WA) monsoon. An accurate simulation of ITCZ migration is essential for the realistic representation of WA precipitation in global coupled models. In this study, we employ the energetics and dynamics framework with a subset of CMIP6 models to investigate the bias in the simulated WA precipitation. Models were found to simulate more local positive (negative) shortwave cloud radiative forcing (SWCRF) in the Southeastern Atlantic Ocean (over the African continent). The effect of the excess local SWCRF is linked to the stagnation of the ITCZ latitudinal migration and the associated biases in the asymmetry index of precipitation. In the models, there is more (less) moist static energy in the lower (mid and upper) troposphere than in the reanalysis. The worst models have a stronger bias, especially over land. The vertical transport of moisture is confined to the boundary layer in the worst model ensemble. In most cases, the high-resolution coupled models show substantial northward migration of the ITCZ compared to the low-resolution models. Furthermore, the best-performing models capture local circulation and energetic processes more accurately than the worst-performing models.
The role of solvent interfacial structural ordering in maintaining stable graphene dispersions
Authors: Patil Urvesh , Caffrey Nuala M
Published: November 2023

Liquid phase exfoliation is the most promising method for the low-cost, scalable production of two-dimensional nanosheets from their bulk counterparts. Extensive exfoliation occurs in most solvents due to the huge amount of energy introduced by sonication or shear mixing. However, the subsequent dispersion is not always stable, with extensive reaggregation occurring in some solvents. Identifying the optimal solvent for a particular layered material is difficult and requires a fundamental understanding of the mechanism involved in maintaining a stable dispersion. Here, we use molecular dynamics calculations to show that when graphene is immersed in a solvent, distinct solvation layers are formed irrespective of the choice of solvent and their formation is energetically favourable for all considered solvents. However, energetic considerations such as these do not explain the experimental solvent-dependence of the dispersion concentration. Instead, we find that solvents with high diffusion coefficients parallel to the graphene layer result in the lowest experimental concentration of graphene in solution. This can be explained by the enhanced ease of reaggregation in these solvents. Solvents with smaller diffusion coefficients result in higher experimental graphene concentrations as reaggregation is prevented. In the low diffusion limit, however, this relationship breaks down. We suggest that here the concentration of graphene in solution depends primarily on the separation efficiency of the initial exfoliation step. Based on this, we predict that the concentration of exfoliated graphene in solvents such as benzaldehyde and quinoline, which have low diffusion constants, can be increased dramatically by careful tuning of the experimental sonication parameters.
Controllable superconducting to semiconducting phase transition in topological superconductor 2M-WS2
Authors: Gautam Sabin , McBride Joseph , Scougale William R , Samarawickrama Piumi I , De Camargo Branco Danilo , Yang Peilin , Fu ZhuangEn , Wang Wenyong , Tang Jinke , Cheng Gary J , Ackerman John , Chien TeYu , Leonard Brian M , Tian Jifa
Published: November 2023

The investigation of exotic properties in two-dimensional (2D) topological superconductors has garnered increasing attention in condensed matter physics, particularly for applications in topological qubits. Despite this interest, a reliable way of fabricating topological Josephson junctions (JJs) utilizing topological superconductors has yet to be demonstrated. Controllable structural phase transition presents a unique approach to achieving topological JJs in atomically thin 2D topological superconductors. In this work, we report the pioneering demonstration of a structural phase transition from the superconducting to the semiconducting phase in the 2D topological superconductor 2M-WS2. We reveal that the metastable 2M phase of WS2 remains stable in ambient conditions but transitions to the 2H phase when subjected to temperatures above 150 °C. We further locally induced the 2H phase within 2M-WS2 nanolayers using laser irradiation. Notably, the 2H phase region exhibits a hexagonal shape, and scanning tunneling microscopy uncovers an atomically sharp crystal structural transition between the 2H and 2M phase regions. Moreover, the 2M to 2H phase transition can be induced at the nanometer scale by a 200 kV electron beam. The electrical transport measurements further confirmed the superconductivity of the pristine 2M-WS2 and the semiconducting behavior of the laser-irradiated 2M-WS2. Our results establish a novel approach for controllable topological phase change in 2D topological superconductors, significantly impacting the development of atomically scaled planar topological JJs.
Examining the adsorption efficiency of iron oxide-decorated magnetic halloysite nanotubes for tetracycline elimination from solutions
Authors: Wang Na , Ma Wei , Hou Yanmin , Gao Hang
Published: November 2023

In our research, we investigated the potential of HNT-Fe3O4, a magnetic adsorbent composed of halloysite nanotubes(HNTs) and iron oxide nanoparticles, for removing tetracyclines(TCs) from water. We utilized a range of analytical techniques such as FT-IR, VSM, XRD, BET, TEM, TGA, and SEM to characterize the materials. Furthermore, we evaluated HNT-Fe3O4’s capability to remove TCs from water, particularly noting the influence of solution pH on its adsorption properties. Results indicated that the adsorption process adhered to the pseudo-second-order kinetics, with the Langmuir model best describing the adsorption isotherms. The reusability study revealed that after six repeated uses, HNT-Fe3O4 maintained most of its adsorption efficiency. An adsorption–desorption experiment further confirmed its potential as a valuable adsorbent for wastewater treatment. In summary, our study underscores the potential of HNT-Fe3O4 as a durable and effective medium for TCs removal in water treatment.
Carbothermal reduction assisted by hydrogenation treatment for preparing single-phase CeC2 nanoscale powders
Authors: Liu Guoqin , Lian Lixian , Liu Ying
Published: November 2023

Single-phase CeC2 powders can be successfully prepared through the carbothermal reduction assisted by hydrogenation treatment (CRHT) using 20–50 nm CeO2 as cerium source and 100–200 nm carbon black as carbon source. During the hydrogenation process, the interaction of CeO2 with H2 leads to a partial valence reduction of Ce ions, yielding a partially anoxic phase (CeO1.675) and a hydrogenated phase (CeH2). CeO1.675 can increase the oxygen vacancies required in the reaction process, while CeH2 can produce gas-phase reductant H2 at the reaction temperature, which together promotes the reduction reaction. The results show that the CRHT can obtain single-phase CeC2 powders at a temperature of 1550 °C, which is 100 °C lower than its theoretical temperature. For the preparation of CeC2 powders, the CRHT is a low-temperature and efficient method.
Risk and self-optimization analysis of the carbon tax policy based on scenario simulation
Authors: Zhang Kanghui , Lu Long
Published: November 2023

The double dividend of the carbon tax policy has been a controversial topic. To comprehensively evaluate the benefits and risks brought by the carbon tax policy and contribute to China’s emission reduction goals, this paper establishes a carbon tax policy cycle simulation model based on China’s economic and energy data from 2010 to 2020 to explore the winner-curse phenomenons of the policy. To alleviate the winner’s curse of the carbon tax policy, this paper introduces a consumer behavior model to explore the optimization degree of loss aversion effect on the carbon tax policy. The research results show that the carbon tax policy has three kinds of winner’s curse phenomenons, namely, the improvement of environmental quality and the reduction of market capital, the decline of national carbon intensity and the increase of carbon intensity of three major industries, and the reuse of the tax revenue and the increase of economic loss. The loss aversion of consumers can alleviate the negative effect of the carbon tax policy and strengthen the positive effect. In addition, during the implementation of the carbon tax policy, the loss aversion effect can also reduce the polluted population by about 2%. Finally, based on the research results, the paper puts forward some feasible policy suggestions.
A comparative analysis of US state-level policies and programs to advance energy justice
Authors: Sandoval Noah , Morgenstein Jonathan , Geiger Jesse , Gibbs Patrick , Bazilian Morgan , Warren Adam
Published: November 2023

The US energy system is undergoing massive changes that have environmental, technological, and societal implications. Decisions and actions taken now will dramatically alter the trajectory of our future energy system. Though new technologies can lessen the dangers of anthropogenic climate change, an effective and sustainable transition requires addressing social justice issues as a priority. To this end, many states have implemented policies and programs that address energy justice. A formal survey of state-level energy justice policies and programs is needed to better understand the methods used to assist communities targeted and the impacts of these efforts. Such an analysis should include an analysis of the metrics used to judge the effectiveness of the enacted policies and programs. In this paper, we analyze the energy justice policies and programs of seven different US states. From this analysis, we identify three important aspects of state energy policies. First, most policies and programs do not articulate their goals, nor cite metrics to judge their successes. This lack of transparency and accountability is a major roadblock to truly just solutions. Second, states focus on a very narrow range of solutions for energy justice issues. The most prevalent being utility bill assistance, which does not address the systemic and enduring challenges faced by many low-income or historically marginalized communities. Lastly, comprehensive energy policy does not acknowledge and address housing, employment, education, and healthcare inequities that exacerbate energy system inequities. The work presented in this paper sheds light on the progress of state-level energy justice policies and programs across the United States, and we argue more work needs to be done to understand best practices in energy justice policymaking.
Deep learning for enhanced free-space optical communications
Authors: Bart M P , Savino N J , Regmi P , Cohen L , Safavi H , Shaw H C , Lohani S , Searles T A , Kirby B T , Lee H , Glasser R T
Published: November 2023

Atmospheric effects, such as turbulence and background thermal noise, inhibit the propagation of light used in ON–OFF keying (OOK) free-space optical (FSO) communication. Here we present and experimentally validate a convolutional neural network (CNN) to reduce the bit error rate of FSO communication in post-processing that is significantly simpler and cheaper than existing solutions based on advanced optics. Our approach consists of two neural networks, the first determining the presence of bit sequences in thermal noise and turbulence and the second demodulating the bit sequences. All data used for training and testing our network is obtained experimentally by generating OOK bit streams, combining these with thermal light, and passing the resultant light through a turbulent water tank which we have verified mimics turbulence in the air to a high degree of accuracy. Our CNN improves detection accuracy over threshold classification schemes and has the capability to be integrated with current demodulation and error correction schemes.
GA-based weighted ensemble learning for multi-label aerial image classification using convolutional neural networks and vision transformers
Authors: Tseng Ming-Hseng
Published: November 2023

Multi-label classification (MLC) of aerial images is a crucial task in remote sensing image analysis. Traditional image classification methods have limitations in image feature extraction, leading to an increasing use of deep learning models, such as convolutional neural networks (CNN) and vision transformers (ViT). However, the standalone use of these models may have limitations when dealing with MLC. To enhance the generalization performance of MLC of aerial images, this paper combines two CNN and two ViT models, comparing four single deep learning models, a manually weighted ensemble learning method, and a GA-based weighted ensemble method. The experimental results using two public multi-label aerial image datasets show that the classification performance of ViT models is better than CNN models, the traditional weighted ensemble learning model performs better than a single deep learning model, and the GA-based weighted ensemble method performs better than the manually weighted ensemble learning method. The GA-based weighted ensemble method proposed in this study can achieve better MLC performance of aerial images than previous results.
Bimetallic nanoparticles green synthesis from litchi leaf extract: a promising approach for breast cancer treatment
Authors: Kaur Ramanjeet , Singh Jitender , Avti Pramod K , Kumar Vivek , Kumar Rajesh
Published: November 2023

Noble metal nanoparticles have demonstrated promising biomedical and nanomedicine applications, and their bimetallic equivalents from the green synthesis approach are expected to be more promising. This study concerns bimetallic nanoparticle’s synthesis, characterization, and structure-function analysis for their potential application in breast cancer. Silver core (SCNPs) and Gold core (GCNPs) bimetallic nanoparticles were synthesized usingLitchi Chinesisleaf extract (LCLE) and characterized using various physio-chemical techniques. The results revealed the successful synthesis of SCNPs and GCNPs with distinct surface plasmon resonance peaks at 551 nm and 531 nm, hydrodynamic sizes of 66 nm and 53 nm, and Zeta potential values of −26.0 mV and −20.6 mV. XRD analysis confirmed the presence of silver and gold phases, while HR-TEM images revealed spherical shapes for SCNPs and heterogenous shapes for GCNPs. Both nanoparticles demonstrated dose and time-dependent inhibition of breast cancer cell growth, with GCNPs requiring a higher concentration than SCNPs at 48 h compared to 24 h. Cell cycle evaluation indicated a cell cycle arrest in the G2M phase for both nanoparticles, an impact on the S phase distribution, and reactive oxygen species (ROS) generation, further contributing to their antiproliferative effects.
Unipotent character sheaves and strata of a reductive group
Authors: Lusztig G.
Published: November 2023

Let

H
H

be a connected reductive group over an algebraically closed field. We define a surjective map from the set

C
S
(
H
)

CS(H)

of unipotent character sheaves on

H
H

(up to isomorphism) to the set of strata of

H
H

. To do this we use the generalized Springer correspondence. We also give a new parametrization of

C
S
(
H
)

CS(H)

in terms of data coming from bad characteristic.
A conjecture by Bienvenu and Geroldinger on power monoids
Authors: Tringali Salvatore , Yan Weihao
Published: November 2023

Let

S
S

be a numerical monoid, i.e., a submonoid of the additive monoid

(

N

,
+
)

(\mathbb N, +)

of non-negative integers with finite complement in

N

\mathbb N

. Endowed with the operation of set addition induced by

S
S

, the family of all finite subsets of

S
S

containing

0
0

is itself a monoid, which we denote by

P

fin

,
0

(
S
)

\mathcal P_{\textrm {fin}, 0}(S)

.

We show that, if

S
1

S_1

and

S
2

S_2

are numerical monoids and

P

fin

,
0

(

S
1

)

\mathcal P_{\textrm {fin}, 0}(S_1)

is isomorphic to

P

fin

,
0

(

S
2

)

\mathcal P_{\textrm {fin}, 0}(S_2)

, then

S
1

=

S
2

S_1 = S_2

. (In fact, we establish a more general result, in which

S
1

S_1

and

S
2

S_2

are allowed to be subsets of the non-negative rational numbers that contain zero and are closed under addition.) This proves a conjecture of Bienvenu and Geroldinger.
Focal Plasmacytoid and Fibrotic Hepatic Lesion In An Autopsy Examination Of A Patient With Multiple Myeloma
Authors: Zaidi A , Liu J , Sonawane S S , Guzman G , Qazi O
Published: November 2023

Introduction/Objective

Multiple Myeloma (MM) is a plasma cell neoplasm mainly affecting the bone marrow. Common sites of extramedullary dissemination are skin, liver, kidneys, and the central nervous system. Though diffuse plasma cell infiltration of the liver has been described in autopsy literature in about 50% of patients with multiple myeloma, it is usually not associated with focal infiltration. Rare cases of plasma cell infiltration leading to non-obstructive cholestasis and acute hepatic failure have been described.

Methods/Case Report

We hereby present a case of 54-year-old decedent male with past medical history of obesity, hypertension, and diabetes mellitus who presented to the emergency department with complains of productive cough, dyspnea, vomiting and back discomfort. Labs showed leukocytosis, thrombocytopenia and hypercalcemia.

Additionally, there was an increase in lactate and serum monoclonal protein levels and derangements in renal and liver function tests. Skeletal bone survey showed a 1.4 cm well-circumscribed lucent lesion within the distal third of the left clavicle and in the calvarium which raised concern for multiple myeloma and tumor lysis syndrome. During the hospital course, the patient’s overall clinical condition declined rapidly, and he passed away on the third day of admission. During the autopsy examination, the patient’s bone marrow revealed diffuse infiltration of plasma cells confirming multiple myeloma. In addition, the histopathological examination of the liver revealed focal plasmacytoid fibrosis, moderate periportal inflammation with plasma cell infiltration and microsteatosis. Immunohistochemical stains with CD138, MUM-1, ISH kappa and lambda and trichrome highlighted the focal plasma cell infiltration and fibrosis in the liver, respectively.

Results (if a Case Study enter NA)

NA

Conclusion

Our case shows the importance of utilizing histopathological and immunohistochemical examination in confirming the diagnosis of multiple myeloma, specifically in the autopsy cases where there is no previous diagnosis of multiple myeloma. In addition, it highlights the awareness of rare focal plasmacytoid fibrosis and infiltration as an extramedullary presentation of multiple myeloma.
Alveolar rhabdomyosarcoma with pre-therapy maturation
Authors: Usman A , Hoyt R A , Hamza A , Meyer A R
Published: November 2023

Introduction/Objective

Alveolar rhabdomyosarcoma (ARMS) is the second most common type of rhabdomyosarcoma in children and adolescents. Common locations include the head and neck, trunk, extremities, and pelvic area. They are a prototypical round cell sarcoma and are treated with multimodality therapy. The purpose of this report is to describe a case of this tumor showing unusual rhabdomyoblastic differentiation which is most commonly seen in post- therapy setting but is almost unheard of pre-therapy.

Methods/Case Report

A three-year-old male presented with painless, right lower extremity mass. It was noticed two months prior and had been rapidly growing since then. Incisional biopsy was performed. Histologic sections showed a round cell sarcoma with an alveolar growth pattern. Variably mature single- and multinucleated rhabdomyoblasts with ample eosinophilic cytoplasm were present throughout the biopsy specimen. On immunostains, the tumor cells were positive for desmin, MyoD1, as well as myogenin (minor subset) and negative for pancytokeratin, CD45 and WT-1, strongly supporting the diagnosis of ARMS. FISH studies showed the presence of FOXO1 (FKHR) rearrangement, further confirming diagnosis.The patient received chemotherapy, radiotherapy, and surgery. On follow-up after six months, the patient was well with no significant complications.

Results (if a Case Study enter NA)

N/A

Conclusion

Post-chemotherapy rhabdomyoblast differentiation is commonly seen and documented in literature, potentially signifying increased response of tumor cells to therapy. Our case highlights that such changes can also be seen pre-treatment and must not sway the pathologist from diagnosis of ARMS.
Clear Cell Sarcoma masquerading as Malignant Melanoma: A Case Report
Authors: Nadri M , Shiwlani S
Published: November 2023

Introduction/Objective

Clear cell sarcoma (CCS) is a rare and diagnostically challenging soft tissue tumor that can mimic other malignancies with melanocytic differentiation. Histologically it shows diffuse sheets of clear cells with scattered melanin pigment in a subset of cases. Other morphologies have been described but contain atleast a portion of clear cell features. We report a case of CCS with unusual histomorphology, highlighting the importance of incorporating cytogenetic and immunohistochemical studies to accurately diagnose this tumor.

Methods/Case Report

We present a case of a 49-year-old male with a left lateral knee mass associated with pain and swelling for one year. A core biopsy revealed a diffuse proliferation of pleomorphic spindle and atypical epithelioid cells. These atypical cells exhibited intranuclear vacuoles, variable prominent nucleoli, abundant dusky cytoplasm, and increased mitotic activity. Immunohistochemical studies were positive for S100, SOX10, and Melan-A (patchy), suggesting a melanocytic differentiation. However, no expression of Preferentially Expressed Antigen in Melanoma (PRAME) or BRAF V600E mutation was noted. Given the clinical history and lack of cutaneous melanocytic lesion, clear cell sarcoma was considered in the differential diagnosis. Fluorescence in situ hybridization (FISH) studies revealed Ewing sarcoma region 1 (EWSR1) gene rearrangement in neoplastic cells, confirming the diagnosis of CCS.

Results (if a Case Study enter NA)

NA

Conclusion

The tumor lacked definitive histologic features including clear cell features, demonstrating the variability in histomorphology that can be encountered with CCS. Distinction of CCS from melanoma is of clinical significance as treatment significantly differs. Accurate diagnosis requires the incorporation of cytogenetic and immunohistochemical studies to differentiate it from melanocytic neoplasms. Variability in histomorphology of CCS can pose, as is evident in our case, as a diagnostic pitfall, and CCS should be considered in the differential diagnosis of unusual non-cutaneous melanocytic proliferations that lack clear cell features and show compelete spindle and epithelioid morphology.
Ossifying fasciitis: A rare phenomenon and a mimicker for malignancy
Authors: Sami F I , Hamza A , Meyer A R
Published: November 2023

Introduction/Objective

Ossifying fasciitis is a relatively rare variant of nodular fasciitis. However, it can mimic malignant lesions, particularly extraosseous osteosarcoma. The purpose of this report is to describe a florid case of ossifying fasciitis with an unusual clinical course in a 17-year-old male.

Methods/Case Report

A 17-year-old male underwent surgery at an outside hospital for a soft tissue mass in his left upper thigh that had been present for over two years. Pathology was consistent with a benign myofibroblastic tumor. No bone formation was present in the biopsy. Next generation sequencing showed a COL1A1::USP6 gene fusion. The patient was then referred to our institution due to rapid recurrence and unresolving infection at the surgery site. An ultrasound revealed a mass measuring 3.3 x 2.7 x 1.3 cm at the surgery site. The patient subsequently underwent wide surgical resection of the mass.Gross inspection and sectioning of the specimen revealed a well-defined, encapsulated firm calcified lesion with approximately 30% soft pink gelatinous cut surfaces. Microscopically, the lesion was composed of spindle-shaped fibroblastic cells and extensive osteoblastic activity with a zonated transition from immature osteoid to immature woven bone. The diagnosis of ossifying fasciitis was rendered.

Results (if a Case Study enter NA)

NA

Conclusion

Rapidly growing lesions can be misinterpreted as sarcomas. Careful microscopic examination and correlation with clinical and radiologic data is critical for accurate diagnosis. Molecular data can be helpful in difficult cases.
Invadopodia formation assay: a promising experiment for targeting breast cancer invasion and metastasis
Authors: Abdelmonem M , Ali Hamad H , Md Hashim N , Al-Samarai A H , Eldaly R , Abdelfattah M Saleh , Wasim H , Abdelmageed M
Published: November 2023

Introduction/Objective

Invadopodia has been found to invade the extracellular matrix (ECM) in multiple cancers, including breast, lung, brain, and prostate, which is highly associated with cancer metastasis. Invadopodia have been shown to form in various cancer cells, such as the MDA-MB-231 breast cancer cell line.

Objectives

In-vitro testing to validate the anti-cancer invasion drugs using an invadopodia formation assay.

Methods/Case Report

MDA-MB-231 triple-negative breast cancer cell line was used in this study due to its highly invasive characteristics obtained from American Type Culture Collection. Cells were cultured in Dulbecco's Modified Eagle's Medium (DMEM), a high-glucose medium containing FBS 10% and 1% penicillin/streptomycin. Cells were maintained in a humidified atmosphere of 95% O2 and 5% CO2 incubator at 37 °C for normal conditions. Cells with low passage numbers were used in order to get accurate results. Then, the gelatin-coated coverslips were prepared for invadopodium assay, washed three times with ddH2O, and transferred to slides containing a drop of antifade, a mounting solution. For invadopodia quantification, invadopodia images on the F-actin, gelatin, and nucleus were taken using the same fluorescence microscope settings (Confocal Laser Leica fluorescent microscope, German). Cells were scored for the presence of underlying invadopodia. The mean percentage of cells with invadopodia formation was calculated for drug-validated tests.

Results (if a Case Study enter NA)

The study revealed how MDA-MB-231 cells penetrate the gelatin that mimics the ECM-like basement membrane in the human body; this is thought to be a key point during intravasation and extravasation steps in metastasis. The study showed actin-rich filament as red dots in the center of the MDA-MB-231 cells, representing invadopodia in a 3D image under normal conditions. In contrast, in a 2D image, invadopodia are represented as black dots on gelatin in a merged image.

Conclusion

Breast cancer is one of the leading causes of cancer-related death in the advanced stage. The study helps to promote using invadopodia assay to validate the effectiveness of the potential anti-cancer drugs and predict cancer metastasis in clinical studies. However, invadopodia formation assay can be especially useful for patients with early-stage cancers; it can help to predict which patients are more likely to benefit from aggressive treatment or further monitoring rather than immediate surgical intervention.
Proliferation Index in “HER2 Low” Metastatic Breast Cancer
Authors: Hrizat A S , Brachtel E
Published: November 2023

Introduction/Objective

There is considerable genetic heterogeneity between primary and metastatic breast cancer. The new classification of the "HER2-low" category includes tumors characterized by a low level of HER2 expression (immunohistochemistry (IHC) score 1+ or 2+ without in situ hybridization (ISH) amplification), in addition to the known HER2 negative (HER2-0) and HER2+ (amplified) cases. The Ki67 proliferation index (PI) can predict breast cancer prognosis. Proliferation changes in metastatic breast cancer and in different HER2 categories are not well delineated in clinical cohorts. In this study, we delineate proliferation characteristics of primary and metastatic breast cancer in association with HER2 status.

Methods/Case Report

We retrospectively reviewed the biological data from 98 metastatic breast cancer specimens for 90 patients from 2018-2021 (see Table 1). As part of the clinical workup, 72 metastatic cancer specimens had PI/Ki67, estrogen receptor (ER), and progesterone receptor (PR) testing by (IHC). HER2 was tested by IHC and reflexed ISH. We identified the overall frequency of breast cancer patients with different HER2 subtypes and compared the PI between primary and metastatic breast cancer within different HER2 categories.

Results (if a Case Study enter NA)

The median age at primary breast diagnosis was 51 (IQR; 42 – 58), and the median for metastatic cancer was 64 (IQR;57-70). Average PI/Ki67 was lower in metastatic cancers than in primary breast cancer samples, 38% and 46%, respectively (t-test, p < .001, two-tailed). Most metastatic and primary tumors were HR-positive, 24 (56%) and 16 (64%). The triple-negative subtype HR-HER2- has the highest PI/Ki67 in primary and metastatic tumors. Among the metastatic specimens, we found “HER2 low” expression in 45 (62.5%); 19 (26.4%) were HER2-positive, and 8 (6.3%) were HER2-0. 85% of traditionally HER2-negative samples were “HER2 low”.

There were no statistically significant differences between the Ki67 proliferation index of “HER2 low”, HER2+, and HER2-0 patients (ANOVA, p= 0.488). Five patients (7%) showed different HER2 expressions between primary and metastatic cancer.

Conclusion

The average PI in our cohort is lower in metastatic breast cancers compared to primary breast cancers. This is an unexpected finding considering the pathophysiology of the metastatic cascade. Including "HER2 low" criteria increases the number of patients with metastatic breast cancer potentially eligible for HER2 targeted treatment from 26.4% (HER2+ / amplified) to over 60% (HER2 1+/2+ not amplified).
Evaluation of association of Magnesium levels with Hand Grip Strength in geriatric patients with hip fracture
Authors: Das S
Published: November 2023

Introduction/Objective

Magnesium is a macronutrient that plays a key role in several cellular processes.It is an essential mineral for bone metabolism. Not much is known about the association of magnesium and the risk of hip fractures in the Asian population. In this case control study, we evaluate the relationship between serum magnesium level and the risk of incident hip fracture. The purpose of this study was to investigate the association between magnesium and hand grip strength in hip fracture risk in the geriatric population residing in North India.

Methods/Case Report

Seventy-five patients with hip fracture, Group I and a similar number of controls, Group II were enrolled in the study. Samples were analyzed for serum levels of magnesium, 25 hydroxy Vitamin D, alkaline phosphatase, calcium, and phosphate by immunoassay. Hand grip strength of study subjects was measured using dynamometer. Correlation between magnesium levels and hand grip strength was analyzed in study population.

Results (if a Case Study enter NA)

Among the 75 subjects, 36 were men and 39 were women. The mean age of hip fracture cases was 63.7 ± 8.4 years which was comparable in men and women. Hypomagnesemia was observed in the hip fracture group (1.43 ± 2.36 mg/dl) whereas magnesium level in the control group was normal (2.35 ± 3.86 mg/dl) (p<0.05). 25 hydroxy Vitamin D levels were significantly lower in cases (9.63 ± 4.53 ng/ml) as compared to controls (24.38 ± 5.27 ng/ml). The mean hand grip strength among hip fracture group (18.31 ± 4.69 kg) was significantly lower compared to that of the control group (31.54 ± 6.12 kg). There was a significant positive correlation between magnesium levels and hand grip strength (r=0.74, p<0.05) in hip fracture population.

Conclusion

Hand grip strength as measured by hand held dynamometer was significantly lower in geriatric hip fracture patients, and there is a significant positive correlation between Magnesium and hand grip strength.