bluuebunny/crossref_metadata_2025 huggingface dataset:
The γ-process nucleosynthesis in core-collapse supernovae
Authors: Roberti L. , Pignatari M. , Fryer C. , Lugaro M.
Published: May 2024

Context. The γ process in core-collapse supernovae (CCSNe) can produce a number of neutron-deficient stable isotopes heavier than iron (p nuclei). However, current model predictions do not fully reproduce solar abundances, especially for 92, 94Mo and 96, 98Ru.

Aims. We investigate the impact of different explosion energies and parametrizations on the nucleosynthesis of p nuclei, by studying stellar models with different initial masses and different CCSN explosions.

Methods. We compared the p-nucleus yields obtained using a semi-analytical method to simulate the supernova to those obtained using hydrodynamic models. We explored the effect of varying the explosion parameters on the p-nucleus production in two sets of CCSN models with initial masses of 15, 20, and 25 M⊙ at solar metallicity. We calculated a new set of 24 CCSN models (eight for each stellar progenitor mass) and compared our results with another recently published set of 80 CCSN models that includes a wide range of explosion parameters: explosion energy or initial shock velocity, energy injection time, and mass location of the injection.

Results. We find that the total p-nucleus yields are only marginally affected by the CCSN explosion prescriptions if the γ-process production is already efficient in the stellar progenitors due to a C−O shell merger. In most CCSN explosions from progenitors without a C−O shell merger, the γ-process yields increase with the explosion energy by up to an order of magnitude, depending on the progenitor structure and the CCSN prescriptions. The general trend of the p-nucleus production with the explosion energy is more complicated if we look at the production of single p nuclei. The light p-nuclei tend to be the most enhanced with increasing explosion energy. In particular, for the CCSN models where the α-rich freeze-out component is ejected, the yields of the lightest p nuclei (including 92, 94Mo and 96Ru) increase by up to three orders of magnitude.

Conclusions. We provide the first extensive study using different sets of massive stars of the impact of varying CCSN explosion prescriptions on the production of p nuclei. Unlike previous expectations and recent results in the literature, we find that the average production of p nuclei tends to increase with the explosion energy. We also confirm that the pre-explosion production of p nuclei in C−O shell mergers is a robust result, independent of the subsequent explosive nucleosynthesis. More generally, a realistic range of variations in the evolution of stellar progenitors and in the CCSN explosions might boost the CCSN contribution to the galactic chemical evolution of p nuclei.
A multiphysics model to predict the surface integrity of EDM machined parts
Authors: Tlili Adnene , Ghanem Farhat
Published: May 2024

This study presented a numerical methodology to elucidate the local mechanical response of the surface layer during and after an EDM electrical discharge, aiming to refine the numerical prediction of the residual stress and strain hardening induced by this process. Advances in models, loads, and boundary conditions were proposed and simulated using the ABAQUS/Explicit computational software. A coherent thermomechanical model was formulated, incorporating Grüneisen’s hydrodynamic behavior coupled with the Johnson-Cook plasticity model. Numerical findings highlighted the efficiency of the uniform heat flux distribution model in predicting residual stresses accurately.
Hanscarl Leuner und die Grundlagen der Psycholytischen Therapie
Authors: Passie Torsten
Published: May 2024

Hanscarl Leuner (1919–1996) gilt aufgrund seines wissenschaftlichen und organisatorischen Engagements als die zentrale Figur der Psycholytischen Therapie in Europa. Die Psycholytische Therapie versucht mithilfe geringer Dosen von Halluzinogenen wie LSD oder Psilocybin Abwehrstrukturen zu lockern und dadurch einen erweiterten Zugang zu unbewussten Konflikten und Seeleninhalten zu gewinnen. Leuner hat mit seinen Forschungen die Grundlagen dieser vor allem in Europa beforschten und verbreiteten Therapie erarbeitet.

Im Unterschied zur Psychedelischen Therapie, die auf 1–2 hochdosierte Sitzungen mit mystischem Verbundenheitserleben abhebt, nutzt die Psycholytische Therapie deutlich mehr Substanzapplikationen (5–25), die stets in eine Langzeitpsychotherapie eingebettet sind. Zentral ist die Arbeit an persönlichen Themen, sowohl im veränderten Bewusstseinszustand als auch in den psychotherapeutischen Sitzungen. Dieser Artikel umreißt die Grundzüge der Psycholytischen Therapie und stellt die Forschungsergebnisse Leuners zu den Grundlagen der Psycholytischen Therapie dar.
Update Barrett-Ösophagus
Authors: Manner Hendrik
Published: May 2024

Das Thema Barrett-Ösophagus begleitet uns bereits geraume Zeit im klinischen
Alltag. In den 70er-Jahren wurde der Zusammenhang mit dem gastroösophagealen
Reflux erkannt, 10 Jahre später mit dem Adenokarzinom des Ösophagus. Ab den
90er-Jahren nahm das Thema Barrett-Ösophagus rasant an Fahrt auf. Die
endoskopischen Möglichkeiten in Diagnostik und Therapie entwickelten sich
schnell weiter. Patienten mit einem Barrett-Ösophagus werden heute
individualisiert überwacht und therapiert. Aktuell wird das diagnostische
Spektrum durch die faszinierenden Möglichkeiten der künstlichen Intelligenz
erweitert.
Anticoagulant Therapy in Pregnant Women with Mechanical Heart Valves: Italian Federation of Centers for Diagnosis and Surveillance of the Antithrombotic Therapies (FCSA) Position Paper
Authors: Campello Elena , Bucciarelli Paolo , Catalani Filippo , Erba Nicoletta , Squizzato Alessandro , Poli Daniela ,   Scientific Reviewer Committee
Published: May 2024

The management of anticoagulant therapy in pregnant women with mechanical heart valves (MHVs) is difficult and often challenging even for clinicians experienced in the field. These pregnancies, indeed, are burdened with higher rates of complications for both the mother and the fetus, compared to those in women without MHVs. The maternal need for an optimal anticoagulation as provided by vitamin K antagonists is counterbalanced by their teratogen effect on the embryo and fetus. On the other hand, several concerns have been raised about the efficacy of heparins in pregnant women with MHVs, considering the high risk of thrombotic complications in these patients. Therefore, numerous clinical issues about the management of pregnant women with MHVs remain unanswered, such as the selection of the best anticoagulant agent, the optimal anticoagulation levels to be achieved and maintained, and the evaluation of long-term effects for both the mother and the fetus. Based on a comprehensive review of the current literature, the Italian Federation of the Centers for the Diagnosis and the Surveillance of the Antithrombotic Therapies (FCSA) proposes experience-based suggestions and expert opinions. Particularly, this consensus document aims at providing practical guidance for clinicians dealing with pregnant women with MHVs, to optimize maternal and fetal outcomes while guaranteeing adequate anticoagulation. Finally, FCSA highlights the need for the creation of multidisciplinary teams experienced in the management of pregnant women with MHVs during pregnancy, delivery, and postpartum, in order to better deal with such complex clinical issues and provide a comprehensive counseling to these patients.
The Impact of Telehealth on Obstetrical Outcomes during the COVID-19 Pandemic
Authors: Saucedo Alexander M. , Ceesay Mamaram , Ravi Sanjana , Mumford Kelsey , Alvarez Miriam , Ghartey Jeny , Harper Lorie M. , Cahill Alison G.
Published: May 2024

Objective Nationwide, obstetric clinics modified prenatal care to include telehealth visits in response to the coronavirus disease 2019 (COVID-19) pandemic, enabling the opportunity to investigate its impact on patient outcomes. We hypothesized that use of prenatal telehealth visits would increase the number of prenatal visits, decrease the frequency of urgent triage/emergency department (ED) visits, and improve perinatal outcomes. This study aimed to determine the impact of telehealth on number of obstetric prenatal visits and urgent triage/ED visits amidst the COVID-19 pandemic.

Study Design This is a retrospective cohort of patients from a federally qualified health center in central Texas. Patients with a singleton gestation who delivered after 32 weeks were included. Comparison groups were made between those patients who delivered between May 2020 and December 2020 (presumed modified prenatal visit schedule with in-person and telehealth) and those patients delivering between June 2019 and February 2020 (the traditional care model with in-person visits only). Multivariable linear and logistic regression models were used to estimate differences in the number of prenatal visits and unscheduled triage/ED visits.

Results A total of 1,654 patients were identified with 801 (48.4%) patients undergoing modified prenatal care and 853 (51.6%) patients receiving traditional care during the study period. No significant differences were seen in overall prenatal attendance or triage/ED presentations. However, when stratified by parity, multiparous patients undergoing modified prenatal care were less likely to experience an urgent triage/ED presentation (8.7 vs. 12.7%; odds ratio, 1.69; 95% confidence interval, 1.10–2.61).

Conclusion When compared with a traditional prenatal visitation cohort prepandemic, patients who received modified telehealth prenatal care during the COVID-19 pandemic had similar prenatal attendance and unscheduled emergency presentations. However, multiparous patients experienced a decreased rate of unscheduled emergency presentations. Supplementing prenatal care with telehealth may provide overall comparable prenatal care delivery.

Key Points
Sodium-Mediated Reductive anti-Dimagnesiation of Diarylacetyl­enes with Magnesium Bromide
Authors: Yorimitsu Hideki , Yamaguchi Haruka , Takahashi Fumiya , Kurogi Takashi
Published: May 2024

Diarylacetylenes undergo anti-dimagnesiation using magnesium bromide and sodium dispersion to afford (E)-1,2-dimagnesioalkenes. This dimagnesiation utilizes simple magnesium bromide as a reduction-resistant electrophile, contrasting with the previously reported dimagnesiation using tricky organomagnesium halides. The resulting vicinal double Grignard reagents react with various electrophiles to yield multisubstituted alkenes stereoselectively.
The Discovery of Oral Cancer Prognostic Factor Ranking Using Association Rule Mining
Authors: Chaowchuen Sitthi , Warin Kritsasith , Somyanonthanakul Rachasak , Panichkitkosolkul Wararit , Suebnukarn Siriwan
Published: May 2024

Objective A 5-year survival rate is a predictor for the assessment of oral cancer prognosis. The purpose of this study is to analyze oral cancer data to discover and rank the prognostic factors associated with oral cancer 5-year survival using the association rule mining (ARM) technique.

Materials and Methods This study is a retrospective analysis of 897 oral cancer patients from a regional cancer center between 2011 and 2017. The 5-year survival rate was assessed. The multivariable Cox proportional hazards analysis was performed to determine prognostic factors. ARM was applied to clinicopathologic and treatment modalities data to identify and rank the prognostic factors associated with oral cancer 5-year survival.

Results The 5-year overall survival rate was 35.1%. Multivariable Cox proportional hazards analysis showed that tumor (T) stage, lymph node metastasis, surgical margin, extranodal extension, recurrence, and distant metastasis of tumor were significantly associated with overall survival rate (p < 0.05). The top associated death within 5 years rule was positive extranodal extension, followed by positive perineural and lymphovascular invasion, with confidence levels of 0.808, 0.808, and 0.804, respectively.

Conclusion This study has shown that extranodal extension, and perineural and lymphovascular invasion were the top ranking and major deadly prognostic factors affecting the 5-year survival of oral cancer.
The Potential Role of Reactive Oxygen Species Produced by Low-Density Neutrophils in Periodontitis
Authors: Mousa Ali Omran , Al Hussaini Ali Hussien Abass , Hussein Hashim Mueen
Published: May 2024

Objective Neutrophils own an arsenal of dischargeable chemicals that enable them to handle bacterial challenges, manipulating innate immune response and actual participation in acquired immunity. The reactive oxygen species (ROS) are one of the most important chemicals that neutrophils discharge to eradicate pathogens. Despite their beneficial role, the ROS were strongly correlated to periodontal tissue destruction. Lowdensity neutrophils (LDN) have been recognized for producing enhanced quantities of ROS. However, the potential role of ROS produced by LDN in periodontitis is unknown. The aim of the study was to investigate the impact of ROS produced by LDN in periodontal diseases.

Materials and Methods Venous blood and periodontal parameters were obtained from 100 systemically healthy subjects divided into 40 participants with healthy periodontium in the control group and 60 with unstable periodontitis in the study group. Flow cytometry was used to measure the production of ROS by LDN in both groups.

Statistical Analysis The data were analyzed for normal distribution using the Shapiro-Wilk test at p < 0.05, Spearman's correlations, and Mann-Whitney U test. Statistical analysis was performed in SPSS v25.

Results No difference between the groups had been obtained in ROS production by LDN. However, a significant positive correlation existed between ROS and clinical attachment loss in periodontitis.

Conclusion LDN exhibits the same ROS generation capacity in the control and periodontitis groups.
The Role of Dental Arch Dimensions and Impacted Third Molars on Mandibular Anterior Segment Crowding
Authors: Selmani Mimoza , Bukleta Manushaqe Selmani , Duci Shkelzen B.
Published: May 2024

Objectives This study aimed to investigate the potential impact of arch dimensions and unerupted third molars on mandibular anterior segment crowding.

Materials and Methods This study included a total of 240 subjects with an average age of 18 years seeking orthodontic treatment. Panoramic radiographs, alginate impressions, and study models were taken for measurements. This study utilized the Ganss ratio to calculate the ratio of retromolar space to the width of the crown of the third molar, along with other measurements such as intercanine and intermolar widths, arch perimeter, and arch length to assess dental arch dimensions.

Results We found that the Ganss ratio and angle B values on both the right and left sides were significantly different between the noncrowding and crowding groups, suggesting a potential role for third molars in mandibular anterior segment crowding. Additionally, there was an increase in angle A on both sides in the crowding group, indicating a more acute angle between the anterior teeth. This study also observed a reduction in the retromolar space on the third molars in the crowding group, further supporting the potential role of third molars in mandibular anterior segment crowding.

Conclusion The findings of our study provide substantial evidence to suggest that third molars may contribute to mandibular anterior segment crowding. These findings highlight the importance of carefully evaluating dental arch dimensions and the presence of third molars when assessing and treating mandibular anterior segment crowding.
Prevalence and Outcomes of Gastrointestinal Anomalies in Down Syndrome
Authors: Elgendy Marwa M. , Cortez Josef , Saker Firas , Mohamed Mohamed A. , Aly Hany
Published: May 2024

Objectives Our objective was to investigate the prevalence of small intestinal atresia and Hirschsprung's disease (HD) in infants with Down syndrome (DS) and its impact on outcomes.

Study Design We analyzed the National Inpatient Sample dataset. We included infants with DS, small intestinal atresia, HD, and the concomitant occurrence of both conditions. Regression analysis was used to control clinical and demographic variables.

Results A total of 66,213,034 infants were included, of whom, 99,861 (0.15%) had DS. The concomitant occurrence of small intestinal atresia and HD was more frequent in infants with DS compared with the general population, adjusted odds ratio (aOR): 122, 95% confidence interval (CI): 96–154, (p < 0.001). Infants with DS and concomitant small intestinal atresia and HD had higher mortality compared with those without these conditions, aOR: 8.59, 95% CI: 1.95–37.8.

Conclusion Infants with DS are at increased risk of concomitant small intestinal atresia and HD, and this condition is associated with increased mortality.

Key Points
Area law for steady states of detailed-balance local Lindbladians
Authors: Firanko Raz , Goldstein Moshe , Arad Itai
Published: May 2024

We study steady-states of quantum Markovian processes whose evolution is described by local Lindbladians. We assume that the Lindbladian is gapped and satisfies quantum detailed balance with respect to a unique full-rank steady state σ. We show that under mild assumptions on the Lindbladian terms, which can be checked efficiently, the Lindbladian can be mapped to a local Hamiltonian on a doubled Hilbert space that has the same spectrum and a ground state that is the vectorization of σ1/2. Consequently, we can use Hamiltonian complexity tools to study the steady states of such open systems. In particular, we show an area-law in the mutual information for the steady state of such 1D systems, together with a tensor-network representation that can be found efficiently.
Development of a dose-rate dosimeter using a silicon photodiode for a medical linear accelerator in a 10 MV flattening filter-free mode
Authors: Yamaguchi Satoshi , Ariga Hisanori , Yoshioka Kunihiro
Published: May 2024

This study was aimed at developing a dose-rate dosimeter to measure the instantaneous dose rate of a commercially available medical linear accelerator. A dose-rate dosimeter composed of a silicon photodiode (Si-PD), a complementary metal-oxide semiconductor single operational amplifier, a resistor of 20 MΩ, a capacitor of 100 pF, and a mini-substrate measuring 16 × 16 mm2 was evaluated. Voltage outputs from the proposed dosimeter were measured using an analog-to-digital converter on a microcomputer. A custom-made x-ray tube generator at an energy of 120 kV with a tube current ranging from 0.1 to 2.0 mA was used for the dose-rate calibration. Dose-rate calibration was performed 83.3 mm from an x-ray source using a commercially available semiconductor dosimeter. The developed Si-PD dosimeter could measure up to 0.6 Gy/s at a distance of 19.3 mm from the x-ray source. Measurements were also performed using a medical linear accelerator in a 10 MV flattening filter-free mode at depths of 0, 25, 50, and 100 mm with an irradiation field of 100 × 100 mm2 at a constant distance of 1000 mm from the source to the dosimeter. A peak voltage variation corresponding to the instantaneous dose rate was observed using a sampling period of 1.0 ms, and the peak voltages decreased with the depth. The detected pulse numbers were 512, 484, 491, and 511 at depths of 0, 25, 50, and 100 mm, respectively.
Analysis of electromagnetic wave characteristics of heterogeneous plasma sheath based on the ZT-DGTD
Authors: Guo Jirong , Han Yiping , Wang Jiajie
Published: May 2024

A hypersonic plasma sheath is an unmagnetized, weakly ionized, and inhomogeneous plasma flow that causes a blackout in radio communication. Studying the propagation of electromagnetic waves in a plasma flow is of significant importance for addressing potential communication disruptions. The discontinuous Galerkin time domain method based on the Z-transform for dispersive media is derived, and the derivation of the Z-transformation is concise and effective. According to different sizes of the plasma parameter, the non-uniform flow field was divided into two enhancement regions and two attenuation regions. By observing the changes in amplitude and phase of electromagnetic fields in different regions of the flow field, the effects of enhancement and attenuation regions on electromagnetic waves can be clearly observed. When the plasma flow field has a significant effect on electromagnetic scattering, regions with different parameters in the flow field exhibit different or even opposite changes in the amplitude and phase of the electromagnetic field. The effects of the enhanced and attenuated regions on electromagnetic scattering can cancel each other out. Under different band conditions, two regions play a dominant role in electromagnetic scattering. The dust plasma flow field was expressed by the relative dielectric constant of weakly ionized dust plasma, and the influence of the dust plasma on electromagnetic scattering was studied. The influence of plasma flow on electromagnetic scattering is weakened by dust particles. This study provides new insights into the influence of non-uniform flow fields on incident waves.
Anomalous superconductivity in Li/F modified two-dimensional molybdenene
Authors: Xie Hongmei , Huang Zhijing , Zhao Yinchang , Huang Hao , Li Geng , Gu Zonglin , Zeng Shuming
Published: May 2024

Dirac materials, due to their unique physical properties, hold vast prospects in both fundamental research and practical applications. Recently, the metallic Dirac material, molybdenene, has been synthesized. However, free-standing molybdenene is found to be dynamically unstable. We propose the use of F/Li to modify its structure and stabilize it. Based on density functional theory, density functional perturbation theory, and anisotropic Migdal–Eliashberg equations, we systematically investigate the electronic structures and superconducting properties of MoF and MoLi. The results indicate that both MoF and MoLi are intrinsic superconductors, with electron–phonon coupling constants of 0.49 and 0.74, respectively. Solving the superconducting gap equation yields a superconducting transition temperature of 7.5 K for MoLi. Further analysis suggests that the coupling between the out-of-plane component of Mo's d orbital electrons and the vibrations of Mo atoms contributes significantly to the electron–phonon coupling in MoLi. Our study lays the foundation for further applications of molybdenene.
Multi-frequency signal acquisition and phase measurement in space gravitational wave detection
Authors: Zhang Qiang-Tao , Liu He-Shan , Dong Peng , Li Pan , Luo Zi-Ren
Published: May 2024

To enhance the accuracy of phase measurement and to prevent tracking errors, it is crucial to effectively read the multi-frequency signal in space gravitational wave detection. In this paper, a novel signal acquisition method called the multi-frequency acquisition algorithm is proposed and implemented. Different from the traditional single-frequency acquisition, the signal characteristics of amplitude and frequency are both considered to better distinguish different frequency components. A phasemeter integrated with the acquisition method and narrow-bandwidth digital phase-locked loop is constructed for the method test and verification. The results show that the multi-frequency acquisition unit can capture all the frequencies of an input signal in several milliseconds. The precision is better than ±200 Hz under a low SNR (signal-to-noise ratio) of 0 dB. The phase noise can reach 2 µrad/Hz1/2 in the frequency range of 0.1–1 Hz and satisfy the requirement of the space gravitational wave detection in all frequency ranges.
Products of distributions and the problem of galactic rotation
Authors: Sarrico C. O. R.
Published: May 2024

In the present paper we study the nonlinear system ut + [ϕ(u)]x + v = 0, vt + ψ(u)vx = 0 as a model for the one-dimensional dynamics of dark matter. We prove that under certain conditions this system, such as the Gurevich-Zybin system, can also explain why the observed rotation speed (relative to the galactic center) of stars near galactic halos do not coincide with what it is expected in classical mechanics. The solutions are obtained in fully explicit formulas, in a convenient space of distributions, without using any result within the classical framework. For such purpose we use the α-solution concept which is defined within a product of distributions. Such a concept generalizes the classical solution concept and for evolution equations may also be seen as an extension of the weak solution concept to the nonlinear setting.
Engulfing behavior of vapor bubbles in downward facing heated surface boiling
Authors: Verma Purnendra Kumar , Nayak Arun Kumar
Published: May 2024

Boiling of the coolant at the hot surface provides relatively better cooling by absorbing latent heat along with convection heat transfer as compared to heat transfer under single-phase conditions. In boiling, the orientation of heated surface also plays a crucial role. Downward facing boiling is complex than upward facing boiling, as the detachment of the bubble inhibited due to the heater surface orientation. Consequently, the bubble residence time and interaction with other bubbles are different in such boiling conditions. Our experiments on a large downward facing flat surface (100 × 400 mm2) revealed unexplored boiling phenomena. The boiling process is dominated by a complex engulfing phenomenon, which is rarely reported in the past. The engulfing phenomena have been captured using high-speed photography, wherein, at low heat fluxes, it is observed that larger bubbles engulf small bubbles by opening their mouth and swallowing the small bubbles. However, at higher heat fluxes, this phenomenon disappears. A larger vapor blanket is formed due to engulfing of bubbles, which may lead to departure from nucleate boiling. This engulfing behavior depends on the heat flux and subcooling. With the increase in heat flux, it is found that the rate of vapor engulfing increases. We have attempted to explain the science behind such engulfing phenomenon based on the capillary pressure difference. These results are consistent at various subcooling. This research provides new insights into nucleate boiling and may help in developing advanced mathematical models for accurate heat transfer prediction on downward facing nucleate boiling.
Multi-fidelity deep learning for aerodynamic shape optimization using convolutional neural network
Authors: Tao Guocheng , Fan Chengwei , Wang Wen , Guo Wenjun , Cui Jiahuan
Published: May 2024

Aerodynamic shape design is essential for improving aircraft performance and efficiency. First, this study introduces a data-driven optimization framework utilizing a multi-fidelity convolutional neural network (MFCNN) for aerodynamic shape optimization. To achieve better optimization results with reduced computational cost, the framework dynamically incorporates new data in each optimization cycle. Specifically, it constantly involves the optimal solution from previous cycle as a new high-fidelity sample and employs a low-fidelity infilling strategy that maximizes the minimum Euclidean distance for selecting new low-fidelity samples. Moreover, a standard synthetic benchmark is used to elaborate the procedure of optimization and show the capability and effectiveness of the framework. Finally, the framework is applied to two aerodynamic shape optimization problems: maximizing the lift-to-drag ratio for the Royal Aircraft Establishment 2822 (RAE2822) airfoils and minimizing the cruise drag coefficient for the three-dimensional (3D) drooped and scarfed non-axisymmetric nacelles. The framework increases the lift-to-drag ratio by 51.21% over the baseline and achieves an 18.79% reduction in the cruise drag coefficient for nacelle optimization, outperforming traditional multi-fidelity deep neural network optimization framework. Sufficiently utilizing the implicit relations between different fidelity levels of data through defined local perceptual fields and convolution, our MFCNN-based optimization framework signifies a step forward in the efficiency and accuracy of aerodynamic shape optimization.
Reversal of crystallization in cryoprotected samples by laser editing
Authors: Rolle K. , Okotrub K. A. , Evmenova E. A. , Kuznetsov A. G. , Babin S. A. , Surovtsev N. V.
Published: May 2024

Advances in cryobiology techniques commonly target either the cooling or the warming cycle, while little thought has been given to ≪repair≫ protocols applicable during cold storage. In particular, crystallization is the dominant threat to cryopreserved samples but proceeds from small nuclei that are innocuous if further growth is forestalled. To this end, we propose a laser editing technique that locally heats individual crystals above their melting point by a focused nanosecond pulse, followed by amorphization during rapid resolidification. As a reference, we first apply the approach to ice crystals in cryoprotected solution and use Raman confocal mapping to study the deactivation of crystalline order. Then, we examine dimethyl sulfoxide trihydrate crystals that can germinate at low temperatures in maximally freeze concentrated regions, as commonly produced by equilibrium cooling protocols. We show how to uniquely identify this phase from Raman spectra and evidence retarded growth of laser-edited crystals during warming.
3D surface profilometry using neutral helium atoms
Authors: Radić Aleksandar , Lambrick Sam M. , von Jeinsen Nick A. , Jardine Andrew P. , Ward David J.
Published: May 2024

Three-dimensional mapping of surface structures is important in a wide range of biological, technological, healthcare, and research applications. Neutral helium atom beams have been established as a sensitive probe of topography and have already enabled structural information to be obtained from delicate samples where conventional probes would cause damage. Here, we empirically demonstrate, for the first time, a reconstruction of a complete surface profile using measurements from a modified scanning helium microscope using the heliometric stereo method and a single detector instrument geometry. Results for the surface profile of tetrahedral aluminum potassium sulfate crystals demonstrate that the areas of surfaces and facet orientations can be recovered to within 5% of the expected values.
A novel configuration capable of enhancing flame acceleration and detonation
Authors: Li Tao , Li Xing , Xu Baopeng
Published: May 2024

This study proposes a novel design concept that leverages the geometric effects of channels with varying diameters and bends to boost flame acceleration and detonation in microchannels. A quasi-direct numerical simulation with detailed chemical kinetics is used to evaluate the processes of flame acceleration and detonation. A comparative study on the impact of equidistant spiral and converging spiral shapes of detonation channels on flame acceleration is conducted and discussed. The results indicate that in the low-speed and high-speed stages of flame propagation, Fermat's spiral channel exhibits a more significant promoting effect on flame acceleration compared to the Archimedes spiral channel. Fermat's spiral channel has significant advantages in terms of combustion efficiency and can save about 30% of fuel during the detonation process. This study helps to further reduce the scale of the detonation system.
Influence of bleeding positions in self-recirculating casing treatments on the stability of a subsonic axial compressor
Authors: Zhang Haoguang , Feng Yiming , Zhang Chiyuan , Xiao Jinhang , Chu Wuli
Published: May 2024

The three-dimensional numerical simulation was used to study the effects of self-recirculating casing treatment (SRCT) on the stability and performance of a subsonic axial flow compressor. The control variable method was used to compare three SRCT structures with different axial bleeding positions. The mechanism of the influence of different SRCTs on the compressor stability was revealed. Unsteady calculation results show that as the bleeding position moves downstream, the stall margin obtained by SRCT increases first and then decreases. SRCTs with bleeding positions at 0.4, 0.8, and 1.3 axial chord length (Ca) obtain 19.74%, 22.72%, and 15.97% stall margin improvement, respectively. The internal flow field analysis shows that the 0.8Ca bleeding position is close to the low-speed fluid at the blade tip, and there is a large pressure difference between the bleeding port and the injection port. This structure can suppress the secondary flow in the blade passage, thereby reducing the mixing loss caused by the tip leakage flow and the mainstream. The airflow inside the SRCT with 0.8Ca bleeding position is smooth, and the flow loss caused by the bleeding effect is low. Therefore, the compressor efficiency of this structure is the highest.
Study of impurity behavior in JET-ILW hybrid scenario with deuterium, tritium, and deuterium–tritium plasmas
Authors: Wendler N. , Chomiczewska A. , Gromelski W. , Kowalska-Strzęciwilk E. , Ivanova-Stanik I. , Challis C. D. , Hobirk J. , Kappatou A. , Lerche E. , Carvalho P. , Coffey I. , Pucella G. , Giovannozzi E. ,   JET Contributors,,   Eurofusion Tokamak Exploitation Team
Published: May 2024

Experimental campaigns at the Joint European Torus with an ITER-like Be/W wall with pure deuterium (D), tritium (T), and deuterium–tritium (DT) were a unique opportunity to explore various aspects related to the ITER operation. One of the most important challenges in recent years was the development of the hybrid scenario for D-T, based on reference deuterium and tritium plasmas. This kind of scenario, one of the foreseen for ITER, is characterized by a low current plasma and a high normalized beta βN factor compared to the parallel optimized baseline scenario [Hobirk et al., Plasma Phys. Controlled Fusion 54, 095001 (2012)]. As the experiments have shown, controlling the plasma edge in the different phases of the hybrid scenario becomes more difficult with higher isotope mass, and therefore, are also in risk of impurity accumulation [Hobirk et al., Nucl. Fusion 63, 112001 (2023)]. For this reason, investigation of the impurity behavior, as well as their control, constituted the crucial issue. The present contribution aims to compare mid-Z and high-Z impurities behavior within H-mode hybrid discharges in D and T plasmas, as well as D and DT plasmas. Detailed analysis shows that in the H-mode regime in the hybrid scenario, higher impurity radiation is observed for DT in comparison to D plasmas, as well as for T compared to D plasmas. Additionally, it was noticed that the most significant contribution to the plasma radiated power comes from W and to a lesser extent from Ni (∼10%). Moreover, it was found that an earlier transition from small edge localized modes (ELMs) to ELM-free phase can result in the earlier increase in impurities.
Role of elasticity on polymeric droplet generation and morphology in microfluidic cross-junctions
Authors: Duan Lian , Yuan Wenjun , Hao Nanjing , Mei Mei
Published: May 2024

Recently, our direct numerical simulations [Duan et al., Phys. Fluids 36, 033112 (2024)] showed that fluid elasticity affects the extension length and pinch-off time of the droplet formation process, thus changing the flow pattern. However, the effect of fluid elasticity on the morphology and properties of polymeric droplets is not yet fully understood. In this work, by analyzing the stretched state of the polymer macromolecule and the velocity distribution of the flow process, we find that the increase in fluid elasticity (characterized by the relaxation time) inhibits the contraction of the dispersed phase during droplet pinching and resists the effect of surface tension after droplet generation, which significantly affects the droplet geometry, volume, and generation frequency. The results demonstrate that the length and volume of polymeric droplets increase with the relaxation time of the polymer fluid, while the generation frequency decreases. Meanwhile, the effects of polymer viscosity and the superficial velocity ratio of the continuous to the dispersed phase on the droplets' morphology are investigated. The semi-empirical models for the length, volume, and generation frequency of polymeric droplets are developed for the first time by considering the elastic interaction. The purpose of our work is to provide a better understanding and experimental guidance for controlling the parameters of polymeric droplets with viscoelasticity of different shapes and sizes.
Experimental study on the rheological behavior of superfine cement–sodium silicate slurry under seawater intrusion
Authors: Shao Changzhi , Zhu Guangxuan , Gong Yu'an , Zhang Qingsong
Published: May 2024

Grouting is the effective method to prevent water inrush and reinforce fractured surrounding rocks in the construction of the submarine tunnel. The seawater intrusion will lead to obvious changes in the rheological properties of slurries, which can be adverse for the diffusion properties of slurries. This study aimed to identify the impact of seawater intrusion on the constitutive relationship of superfine cement–sodium silicate slurry (SC-S slurry). The chemical gelling time, viscosity, and rheological model of the slurry were studied. The concentrations of seawater ranged from 0% to 100%. The water–cement ratio ranged from 0.6 to 2.0. This study revealed that seawater significantly shortened the chemical gelling time of the slurry. The effect was more pronounced as the concentration of seawater increases. Furthermore, it was observed the rheological model of SC-S slurry will change from Bingham model to Herschel–Bulkley model with the increase in concentration of seawater. Rheological parameters that vary with time were also studied. The rheological constitutive models of slurry under seawater intrusion were established.
Structural properties of spherically confined hydrogenic atoms: Effect of dense quantum plasmas
Authors: Das Netai , Ghoshal Arijit
Published: May 2024

Structural properties of the hydrogenic atoms, embedded in a quantum plasma environment and contained in a spherical box, have been investigated theoretically. The organized effect of the quantum plasma is represented by an effective potential characterized by the quantum wave number (QWN). The corresponding Schrödinger equation has been solved variationally by employing a large wave function which takes into account the Dirichlet boundary condition (vanishing of wave function on the boundary of the box). An inclusive study is made on the combined effect of the plasma confinement and spatial confinement on the bound states of the atoms. Eigenenergies, 2k-pole oscillator strength, 2k-pole polarizability, and various geometric expectation values of the radial coordinate are calculated quite accurately for different values of the QWN and box size. For the unconstrained atom, our present results are in excellent agreement with some of the accurate results available in the literature. Special emphasis is given to report the critical values of the box size and QWN which augur the instability of the atoms. Moreover, scaling of the Hamiltonian is critically analyzed and an empirical relation is presented for calculating the critical box size for any hydrogenic atom at a given QWN from the knowledge of the critical box size of the hydrogen atom at that QWN.
Direct numerical simulation of mechanism and control of secondary instability induced transition in a supersonic boundary layer
Authors: Liu Zaijie , Huang Hexia , Liu Mengying
Published: May 2024

Mechanisms and control of secondary-instability-induced-transition in a supersonic boundary layer are studied numerically via direct numerical simulation. The aim is to investigate and compare the transition mechanisms of fundamental, subharmonic, asymmetric subharmonic, and detuned resonances, and to control these secondary instabilities using a local wall cooling strip. The results indicate that the nonlinear interaction between the high-amplitude primary mode and low-amplitude secondary modes is the main contributor to transition. The mutual- and self-interactions of the primary and secondary modes generate other harmonic modes with laminar breakdown soon appearing. The asymmetric subharmonic resonance induces the earliest transition, while the fundamental subharmonic has the latest. Wall cooling effects are also studied. The results show that a lower wall temperature significantly suppresses the secondary instabilities, and steady modes become dominant and lead to obvious streamwise vortexes. Numerical data demonstrate that all secondary-instability-induced transitions result in fully developed turbulent boundary layers, as supported by the skin friction and scaled velocity profiles. The transition control cases indicate that the local wall cooling strip can significantly delay the transition by suppressing the growth of the primary mode. An upstream control strip is found to have a more obvious suppression effect. The fundamental and asymmetric subharmonic resonances are sensitive to the location of the local wall cooling strip and show a stronger transition delaying effect.
Lipid-derived electrophiles inhibit the function of membrane channels during ferroptosis
Authors: Van Kessel Antonius T. M. , Cosa Gonzalo
Published: May 2024

The therapeutic targeting of ferroptosis requires full understanding of the molecular mechanism of this regulated cell death pathway. While lipid-derived electrophiles (LDEs), including 4-hydroxy-2-nonenal (4-HNE), are important biomarkers of ferroptosis, a functional role for these highly reactive species in ferroptotic cell death execution has not been established. Here, through mechanistic characterization of LDE-detoxification impairment, we demonstrate that LDEs mediate altered protein function during ferroptosis. Applying live cell fluorescence imaging, we first identified that export of glutathione-LDE-adducts through multidrug resistance-associated protein (MRP) channels is inhibited following exposure to a panel of ferroptosis inducers (FINs) with different modes of action (type I-IV FINs erastin, RSL3, FIN56, and FINO
2
). This channel inhibition was recreated by both initiation of lipid peroxidation and treatment with 4-HNE. Importantly, treatment with radical-trapping antioxidants prevented impaired LDE-adduct export when working with both FINs and lipid peroxidation initiators but not 4-HNE, pinpointing LDEs as the cause of this inhibited MRP activity observed during ferroptosis. Our findings, when combined with reports of widespread LDE alkylation of key proteins following ferroptosis induction, including MRP1, set a precedent for LDEs as critical mediators of ferroptotic cell damage. Lipid hydroperoxide breakdown to form truncated phospholipids and LDEs may fully explain membrane permeabilization and modified protein function downstream of lipid peroxidation, offering a unified explanation of the molecular cell death mechanism of ferroptosis.
Dichotomous dynamics of magnetic monopole fluids
Authors: Hsu Chun-Chih , Takahashi Hiroto , Jerzembeck Fabian , Dasini Jahnatta , Carroll Chaia , Dusad Ritika , Ward Jonathan , Dawson Catherine , Sharma Sudarshan , Luke Graeme M. , Blundell Stephen J. , Castelnovo Claudio , Hallén Jonathan N. , Moessner Roderich , Davis J. C. Séamus
Published: May 2024

A recent advance in the study of emergent magnetic monopoles was the discovery that monopole motion is restricted to dynamical fractal trajectories [J. N. Hallén
et al.
,
Science
378
, 1218 (2022)], thus explaining the characteristics of magnetic monopole noise spectra [R. Dusad
et al., Nature
571
, 234 (2019); A. M. Samarakoon
et al.
,
Proc. Natl. Acad. Sci. U.S.A.
119
, e2117453119 (2022)]. Here, we apply this novel theory to explore the dynamics of field-driven monopole currents, finding them composed of two quite distinct transport processes: initially swift fractal rearrangements of local monopole configurations followed by conventional monopole diffusion. This theory also predicts a characteristic frequency dependence of the dissipative loss angle for AC field–driven currents. To explore these novel perspectives on monopole transport, we introduce simultaneous monopole current control and measurement techniques using SQUID-based monopole current sensors. For the canonical material Dy
2
Ti
2
O
7
, we measure

Φ
(
t
)

, the time dependence of magnetic flux threading the sample when a net monopole current

J

t

=

Φ
˙

(
t
)

/

μ
0

is generated by applying an external magnetic field

B
0

t

.

These experiments find a sharp dichotomy of monopole currents, separated by their distinct relaxation time constants before and after
t
~

600
 
μ
s

from monopole current initiation. Application of sinusoidal magnetic fields

B
0

t

=
B
c
o
s

ω
t

generates oscillating monopole currents whose loss angle

θ

f

exhibits a characteristic transition at frequency

f
≈
1.8
 
kHz

over the same temperature range. Finally, the magnetic noise power is also dichotomic, diminishing sharply after
t
~

600
 
μ
s

. This complex phenomenology represents an unprecedented form of dynamical heterogeneity generated by the interplay of fractionalization and local spin configurational symmetry.
Poc1 bridges basal body inner junctions to promote triplet microtubule integrity and connections
Authors: Ruehle Marisa D. , Li Sam , Agard David A. , Pearson Chad G.
Published: May 2024

Basal bodies (BBs) are conserved eukaryotic structures that organize cilia. They are comprised of nine, cylindrically arranged, triplet microtubules (TMTs) connected to each other by inter-TMT linkages which stabilize the structure. Poc1 is a conserved protein important for BB structural integrity in the face of ciliary forces transmitted to BBs. To understand how Poc1 confers BB stability, we identified the precise position of Poc1 in the Tetrahymena BB and the effect of Poc1 loss on BB structure. Poc1 binds at the TMT inner junctions, stabilizing TMTs directly. From this location, Poc1 also stabilizes inter-TMT linkages throughout the BB, including the cartwheel pinhead and the inner scaffold. The full localization of the inner scaffold protein Fam161A requires Poc1. As ciliary forces are increased, Fam161A is reduced, indicative of a force-dependent molecular remodeling of the inner scaffold. Thus, while not essential for BB assembly, Poc1 promotes BB interconnections that establish an architecture competent to resist ciliary forces.
Effects of oxygen vacancies on the optical and electrical performances of silicon-based Er doped Ga2O3 films
Authors: Pang Houwei , Wang Yuan , Wu Yunfeng , Lin Sichen , Li Dongsheng , Yang Deren
Published: May 2024

Effects of oxygen vacancies on the optical and electrical properties of silicon-based Er doped Ga2O3 films are investigated. The content of oxygen vacancies can be tuned by changing the Ar:O2 flow ratios during sputtering, and the films sputtered in pure Ar are proved to possess the most oxygen vacancies by the calculations of energy band structure and carrier concentration. It is found that oxygen vacancies are involved in the process of indirect Er3+ ions related emission. With more oxygen vacancies introduced, the conductivity and energy transfer efficiency of Er doped Ga2O3 films can be enhanced simultaneously, leading to the increasing electroluminescence intensity of the light-emitting devices. The optimized silicon-based devices present the maximum optical power density of ∼2 μW cm−2.