bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of storage conditions on the brownstock washing and oxygen delignification of kraft pulps
Authors: Senthilkumar Eashwara Raju , Sjöström Jenny , Henriksson Gunnar , Vikström Tomas , Sevastyanova Olena
Published: January 2025

A long-term goal of the pulping industry is to optimize process parameters for efficiently removing degraded and soluble lignin during the fiber line processes such as kraft pulping, brownstock washing, and bleaching. This study investigates how pulp storage affects the efficiency of brownstock washing and oxygen delignification. Three pulp groups were rinsed with warm and cold water at 40 °C and 5 °C, respectively, and then stored under varying conditions (1 day, 1 week at temperatures of 5 °C and 60 °C. Our findings indicate that after one week of storage at 60 °C, more lignin was extracted, highlighting the influence of storage temperature and time on Kappa reduction (lignin removal) during storage. Additionally, larger lignin fragments were removed with increased storage temperature and time, suggesting that degraded lignin molecules trapped within the fibers can leach out during storage and be subsequently removed in washing. The different storage conditions had only a slight effect on oxygen delignification performance. We conclude that storage conditions, particularly temperature and time, significantly impact lignin removal efficiency and can enhance the pulp washing process. This study also provides valuable insights into lignin mass transfer during storage, offering guidance for industrial applications. The study also revealed that pulp quality after oxygen delignification is influenced by pH and lignin agglomeration and retention in the fibers during preceding washing and storage operations, emphasizing the need for careful control of the latter conditions to minimize cellulose degradation.
Approximating exponentials of commutators by optimized product formulas
Authors: Casas F. , Escorihuela-Tomàs A. , Moreno Casares P. A.
Published: January 2025

Trotter product formulas constitute a cornerstone quantum Hamiltonian simulation technique. However, the efficient implementation of Hamiltonian evolution of nested commutators remains an under explored area. In this work, we construct optimized product formulas of orders 3–6 approximating the exponential of a commutator of two arbitrary operators in terms of the exponentials of the operators involved. The new schemes require a reduced number of exponentials and thus provide more efficient approximations than other previously published alternatives. They can also be used as basic methods in recursive procedures to increase the order of approximation. We expect this research will improve the efficiency of quantum control protocols, as well as quantum algorithms such as the Zassenhaus-based product formula, Magnus operator-based time-dependent simulation, and product formula schemes with modified potentials.
Quantitative methodology for poly (butylene adipate-co-terephthalate) (PBAT) microplastic detection in soil and compost
Authors: Hernandez-Charpak Yvan D. , Kansara Harshal J. , Lodge Jeffrey S. , Eddingsaas Nathan C. , Lewis Christopher L. , Trabold Thomas A. , Diaz Carlos A.
Published: January 2025

With the increasing use of biodegradable plastics in agriculture and food packaging, it has become increasingly important to assess the effects of their fragmentation and mineralization in the environment (i.e., soil, compost). PBAT is a biodegradable polyester widely used in biodegradable mulch films that are intended to fragment and mineralize in soil. To study these effects, novel methodologies are needed to quantify PBAT microplastics in these diverse environments. This work seeks to answer whether gas chromatography mass spectrometry (GCMS) can be used as a tool to assess PBAT microplastics in soil. A method was developed that allows PBAT soil extraction by ultrasonication and GCMS quantification after a fatty acid methyl ester derivatization. To validate the method, an industrial compost degradation experiment was carried out to evidence the weight loss of PBAT film and quantify the micro- and nano-plastic generated from them. The presented method improved the existing resolution by, at least, one order of magnitude compared to reported methods. In conclusion, a novel, simple, affordable, and reproducible methodology for PBAT microplastic detection was developed improving the limits of detection and quantification. The method was tested on an industrial compost experiment, demonstrating the ability to trace the totality of the plastic over time, evidencing that PBAT is consumed in the industrial compost environment.
Validation of a contour diagram-based model for monopile cyclic design in sand and clay
Authors: Lapastoure Louis-Marin , Jalilvand Soroosh , Igoe David
Published: January 2025

Monopiles are the most popular type of foundation for offshore wind turbines. Although capturing the effects of cyclic loading is critical to the design of monopiles, there is no recommended approach in the main design standards and no consensus in the literature as to how this can be achieved. Hence, this paper presents the step-by-step methodology and validation of a new cyclic model in sand and clay. The model consists of the degradation of monotonic soil reaction curves based on soil cyclic contour diagrams. The model is found to provide a very satisfactory match with the PISA field tests in Dunkirk dense marine sand and Cowden stiff glacial till.
Articles with Franciscan Content in The Americas, 1944–2023
Authors: Schwaller John F.
Published: January 2025

The year 2024 marks an important double anniversary for the journal The Americas. On the one hand, it marks 80 years of publication, with the first issue dated July 1944. On the other, it marks the quincentenary of the arrival of the first Franciscans to North America, when the first group of missionary friars landed in what is now Mexico. The history of the journal is rooted in the Franciscan Order. In April 1944 Franciscan historians from throughout North America met in Washington, DC, and founded the Academy of American Franciscan History. The goal of the Academy, as articulated in the records of that inaugural meeting is to “discover and assemble documents and books of Franciscan interest, to compile a complete bibliographical index of American Franciscana, to edit and publish documents, and to issue original historical works.”1 The Academy additionally pledged to publish a journal, a quarterly review of inter-American cultural history: The Americas.
Lowering of Tropopause and Strengthening of Tropopause Inversion Layer at Antarctica During the 2002 and 2019 Southern Sudden Stratospheric Warming Events as Seen by Radiosonde Observations and ERA5 Reanalysis
Authors: Yang Lingyun , Zhang Shaodong , Huang Chunming , Huang Kaiming , Gong Yun , Ma Zheng , Luo Jiahui , Wang Rui
Published: January 2025

Using radiosonde and ERA5 reanalysis data, we investigated the spatial and temporal variations in the tropopause and tropopause inversion layer (TIL) in the Antarctic region during the 2002 and 2019 southern sudden stratospheric warming (SSW) events and the mechanism involved. Following these SSW events there was a sharper TIL and a warmer and lower tropopause. After the onset of rapid warming during the major SSW event in 2002 and the minor SSW event in 2019, the magnitudes of these anomalies increased and reached their respective first peaks. The anomalies increased and peaked again following the early final breakdown of the polar vortex (i.e., the switch to summer circulation). During the SSW events and final breakdown of the polar vortex in 2002 and 2019, stratospheric residual mean circulation, which was driven by planetary waves, was the primary cause of these anomalies. The adiabatic heating of the anomalous downwelling residual mean circulation above the tropopause led to a decrease in the tropopause height and a warming of the tropopause temperature. It also led to increased static stability near the tropopause by dynamical heating, which represented a strengthened TIL. In addition, approximately 4% and 1.9% of the strengthening of the TIL in 2002 and 2019, respectively, can be attributed to the increased anticyclonic circulation at the tropopause.
Expert consensus on orthodontic treatment of protrusive facial deformities
Authors: Pan Jie , Lu Yun , Liu Anqi , Wang Xuedong , Wang Yu , Gong Shiqiang , Fang Bing , He Hong , Bai Yuxing , Wang Lin , Jin Zuolin , Li Weiran , Chen Lili , Hu Min , Song Jinlin , Cao Yang , Wang Jun , Fang Jin , Shi Jiejun , Hou Yuxia , Wang Xudong , Mao Jing , Zhou Chenchen , Liu Yan , Liu Yuehua
Published: January 2025

Protrusive facial deformities, characterized by the forward displacement of the teeth and/or jaws beyond the normal range, affect a considerable portion of the population. The manifestations and morphological mechanisms of protrusive facial deformities are complex and diverse, requiring orthodontists to possess a high level of theoretical knowledge and practical experience in the relevant orthodontic field. To further optimize the correction of protrusive facial deformities, this consensus proposes that the morphological mechanisms and diagnosis of protrusive facial deformities should be analyzed and judged from multiple dimensions and factors to accurately formulate treatment plans. It emphasizes the use of orthodontic strategies, including jaw growth modification, tooth extraction or non-extraction for anterior teeth retraction, and maxillofacial vertical control. These strategies aim to reduce anterior teeth and lip protrusion, increase chin prominence, harmonize nasolabial and chin-lip relationships, and improve the facial profile of patients with protrusive facial deformities. For severe skeletal protrusive facial deformities, orthodontic-orthognathic combined treatment may be suggested. This consensus summarizes the theoretical knowledge and clinical experience of numerous renowned oral experts nationwide, offering reference strategies for the correction of protrusive facial deformities.
In-vitro accuracy of the virtual patient model with maxillomandibular relationship at centric occlusion using 3D-printed customized transfer key
Authors: Nguyen Anh Ho-Quynh , Huynh Nam Cong-Nhat , Nguyen Oanh Ngoc-Hoang , Nguyen Nhat Dinh-Minh , Phan Hai Hoang , Kim Jong-Eun , Jin Gan , Nguyen Khanh Hung , Hoang Hung Trong
Published: January 2025

Objective

This study aimed to create a 3D-printed customized transfer key and evaluate the accuracy of the virtual patient model with maxillomandibular relationship at centric occlusion using the transfer key.

Methods

A 3D-printed transfer key was designed, combining facial and intraoral (IOS) scans. The design included components that recorded the 3D upper and lower arch at centric occlusion. The virtual patient model image was generated in-vitro using a phantom head with soft tissue simulation. Accuracy was assessed by superimposing the 3D scans with reference CBCT images and analyzing trueness and precision using root mean square (RMS) deviations.

Results

The transfer key included an intra-oral part that acts as an anterior deprogrammer to record the relationship of two dental arches at centric occlusion (CO) and an extra-oral with a rotatable cross-shaped design with two arms for locating the facial midline and the two pupils connecting line. Superimposition demonstrated high trueness (RMS: 0.51 mm for the arch regions, 0.69 mm for the whole head region, 0.85 mm in the face region) and precision (RMS: 0.41 mm for the arch regions, 0.52 mm for the entire head, 0.63 mm in the face region) significantly (p < 0.05). Minimal deviations were observed in critical areas, including the tooth and lip position, indicating that the virtual patient model was closely aligned with the CBCT reference. The dental arches achieved the highest accuracy, while slight deviations were noted in the facial regions.

Conclusions

The 3D-printed customized transfer key effectively enhanced the virtual patient model’s accuracy, surpassing traditional trueness and precision methods. This novel approach offers a streamlined, patient-friendly solution for digital dental workflows.
The zinc-finger transcription factor Blimp1/Prdm1 is required for uterine remodelling and repair in the mouse
Authors: Xypolita Maria-Eleni , Goolam Mubeen , Bikoff Elizabeth K. , Robertson Elizabeth J. , Mould Arne W.
Published: January 2025

The zinc finger transcription factor Blimp1/PRDM1 regulates gene expression in diverse cell types. Its activity controls the maternal decidual response at early post-implantation stages of development. The present experiments demonstrate surprisingly that Blimp1 activity in the uterus is required for tissue remodelling at sites of embryonic failure. Moreover Blimp1 mutant females are refractory to RU486 induced decidual shedding. RNA-seq together with immunostaining experiments strongly suggest that the failure to up-regulate expression of the matrix metalloprotease Mmp10 in combination with insufficient suppression of BMP signalling, likely explain Blimp1-dependent phenotypic changes. In the post-partum uterus Blimp1 together with Mmp10 are highly upregulated at sites of tissue repair following placental detachment. Conditional Blimp1 removal significantly impairs the re-epithelization process and severely impacts involution of the endometrium and luminal epithelium. Overall these results identify Blimp1 as a master regulator of uterine tissue remodelling and repair.
Mathematical modeling of water sorption isotherms in specialty coffee beans processed by wet and semidry postharvest methods
Authors: Collazos-Escobar Gentil A. , Hurtado-Cortés Valeria , Bahamón-Monje Andrés Felipe , Gutiérrez-Guzmán Nelson
Published: January 2025

This study investigates the experimental assessment and mathematical modeling of the water sorption isotherms in dried specialty coffee beans processed by wet and semidry postharvest methods. The wet and semidry sorption isotherms were experimentally obtained over a range of water activities between 0.1 and 0.85 at temperatures of 25, 35, and 45 °C using the dynamic dew point method (DDI). Mathematical modeling was conducted to describe the influence of water activity, temperature, and postharvest method on the equilibrium moisture content. Twelve conventional sorption equations and four machine learning techniques were employed for modeling, using 75% of the experimental data for training and 25% for validation. The selection of the best model was carried out via multifactor Analysis of Variance (ANOVA). Experimental results showed that wet and semidry coffee beans exhibited a type II S-shaped isotherm (Brunauer–Emmett–Teller classification) and a significant (p < 0.05) influence of temperature on sorption curves. Additionally, the mucilaginous coating found in semidry coffee beans provided a protective role against water sorption. The Support Vector Machine (SVM) model provided the best fit for describing the sorption isotherms (mean relative error, MRE < 1% and adjusted coefficient of determination, R
2
adj > 99%), demonstrating its robustness in predicting the equilibrium moisture content as a function of water activity, temperature, and postharvest processing method. This mathematical model could serve as a virtual representation of the storage process, facilitating real-time decision-making to enhance coffee quality management during storage.
The computerized algorithm for renal assessment improves diagnostic accuracy of renal impairment in hospitalized patients
Authors: Chen Chun-You , Chang Te-I. , Chen Cheng-Hsien , Hsu Shih-Chang , Chu Yen-Ling , Huang Nai-Jen , Sue Yuh-Mou , Chen Tso-Hsiao , Huang Po-Hsun , Liu Chung-Te , Hsieh Hui-Ling
Published: January 2025

In hospitalized patients, acute kidney injury (AKI) is an important adverse event associated with high mortality and medical costs. Accurate diagnosis and timely management of AKI are essential for improving the outcomes of in-hospital AKI, and delayed diagnosis or misdiagnosis hinders advancements in AKI care. To ameliorate this problem, several electronic AKI alert systems have been proposed but have shown inconsistent effects on AKI outcomes. Before electronic systems can improve AKI outcomes, it is important to confirm their diagnostic accuracy. The purposes of the present study were to establish an easy-to-construct computerized algorithm for the diagnosis of renal impairment and to test its accuracy. The present study retrospectively included 1551 patients hospitalized in Wanfang Hospital with serum creatinine (SCr) levels > 1.3 mg/dL. A computerized algorithm was constructed to identify AKI events and chronic kidney disease (CKD) in these patients. Previous SCr tests were reviewed to define baseline SCr levels. A SCr level increased > 1.5 times from baseline was defined as AKI. An estimated glomerular filtration rate (eGFR) of < 60 mL/min/1.73 m2 for > 90 days was defined as CKD. Discharge diagnoses made by the attending physicians were defined as “clinician’s diagnoses.” The researcher’s diagnoses, made by experienced nephrologists according to the same criteria, were the gold standard to which the computerized algorithms and the clinician’s diagnoses were compared. The diagnoses made by the computerized algorithm and clinician were compared with the researcher’s diagnoses to define their accuracy. Among the included patients, the mean age was 73.0 years; in-hospital mortality was 14.8%, and AKI was present in 28.6% of patients. Regarding the diagnostic accuracy for AKI, the computerized algorithm achieved a sensitivity of 85.6% and a specificity of 98.8%. The main cause of false-negative (FN) AKI diagnosis was AKI occurring prior to the outpatient visit, before the indexed hospitalization. Regarding the diagnostic accuracy for CKD, the computerized algorithm achieved a sensitivity of 94.7% and specificity of 100%. The main cause of FN CKD diagnosis was the lack of previous eGFR records. The computerized algorithm exhibited significantly superior accuracy compared to the clinician’s diagnoses for both AKI (95.0% vs. 57.0%) and CKD (96.5% vs. 73.6%). We developed a simple and easy-to-construct computerized algorithm for the diagnosis of renal impairment that demonstrated significantly improved diagnostic accuracy for AKI and CKD compared to that of clinicians. In the future, an algorithmic approach for the differential diagnosis of AKI and a decision guide should be incorporated into this system.
Identification of novel genetic variants associated with feline cardiomyopathy using targeted next-generation sequencing
Authors: Raffle Jade , Novo Matos Jose , Wallace Marsha , Wilkie Lois , Piercy Richard J. , Elliott Perry , Connolly David J. , Luis Fuentes Virginia , Psifidi Androniki
Published: January 2025

Cardiomyopathies are the most common heritable heart diseases in cats and humans. This study aimed to identify novel genetic variants in cats with hypertrophic cardiomyopathy (HCM) and restrictive cardiomyopathy (RCM) using a targeted panel of genes associated with human cardiomyopathy. Cats were phenotyped for HCM/RCM by echocardiography ± necropsy. DNA was extracted from residual blood, and targeted next-generation sequencing was performed on two separate feline cohorts: an across-breed cohort (23 healthy cats and 21 HCM-affected pedigree or Domestic Shorthair cats), and a within-breed cohort of Birman pedigree cats (14 healthy, 8 HCM-affected, and 6 RCM-affected). Genome Analysis Toolkit was used for variant discovery. Genomic association analyses, including the covariates breed, age, and sex, were conducted to identify genetic variants of interest. We identified genetic variants associated with both HCM and RCM susceptibility in the sarcomeric genes ACTC1, ACTN2, MYH7, TNNT2 and the non-sarcomeric gene CSRP3 in the Birman pedigree cats. These findings suggest that, as proposed in humans, there is at least partial overlap in the genetic background between the HCM and RCM phenotypes in cats. These findings offer potential insights for comparative cardiac research and translational medicine.
Proteogenomic analysis reveals Arp 2/3 complex as a common molecular mechanism in high risk pancreatic cysts and pancreatic cancer
Authors: Mahmud A. K. M. Firoj , Mansour Aly Dina Gamaleldin , Zhao Yelin , Benson Mikael , Smelik Martin , Sysoev Oleg , Wang Hui , Li Xinxiu
Published: January 2025

Pancreatic cysts, particularly intraductal papillary mucinous neoplasms (IPMNs), pose a potential risk for progressing to pancreatic cancer (PC). This study investigates the genetic architecture of benign pancreatic cysts and its potential connection to PC using genome-wide association studies (GWAS). The discovery GWAS identified significant genetic variants associated with benign cysts, specifically the rs142409042 variant near the OPCML gene. A pairwise GWAS comparing PC to benign cysts revealed the rs7190458 variant near the BCAR1 and CTRB1 genes. Further analysis with identified GWAS genes highlighted the Actin Related Protein (Arp) 2/3 complex as a potentially important molecular mechanism connecting benign cysts and PC. The Arp2/3 complex-associated genes were significantly upregulated in PC, suggesting their role in the malignant transformation of pancreatic cysts. Differential expression of these genes was observed across various cell types in PC, indicating their involvement in the tumor microenvironment. These findings suggest that the Arp2/3 complex-associated genes can serve as potential biomarkers for predicting the malignant transformation of pancreatic cysts, opening new avenues for targeted therapies and early detection strategies.
An AQbD driven stability indicating HPLC method for simultaneous estimation of lamivudine, tenofovir disoproxil fumarate and efavirenz in plasma
Authors: Kumar Avichal , Somasekhar Vanita , Dhiman Sumit , Nanjappa Shivakumar Hagalavadi , Avlani Dhruti
Published: January 2025

Advanced AQbD involving D-optimal and Box–Behnken designs for precise analysis of fixed dose combination of antiretrovirals in plasma.
Navigating the evolution of two-dimensional carbon nitride research: integrating machine learning into conventional approaches
Authors: Mondal Deep , Datta Sujoy , Jana Debnarayan
Published: January 2025

Carbon nitride research has reached a promising stage with diverse applications in photocatalysis, energy storage, and sensing, driven by its unique properties and significant contributions from cutting-edge machine learning approaches.
Simple accessible clemastine fumarate analogues as effective antileishmanials
Authors: Charlton Rebecca L. , Escrivani Douglas O. , Brown Christopher , Thota Niranjan , Agostino Victor S. , Porta Exequiel O. J. , Avkiran Timur , Merritt Andrew T. , Denny Paul W. , Rossi-Bergmann Bartira , Steel Patrick G.
Published: January 2025

N-linked analogues of clemastine fumarate afford simpler, more accessible, more selective antileishmanials.
Carbon dots derived from organic drug molecules with improved therapeutic effects and new functions
Authors: Wu Zhao-Fan , Luo Xiao-Xiao , Shi Xiao-Feng , Wang Bao-Juan , Sun Hao-Wen , Sun Zhao-Nan , Mao Yuan-Qing , Xiong Huan-Ming
Published: January 2025

This article reviews the functions of drug-derived CDs compared with their precursors and demonstrates their broad application prospects in biomedicine.
Tailoring polyester-based diblock copolymers for boron-enhanced drug delivery: synthesis, kinetics, and nanoparticle characterization
Authors: Mundil Robert , Marková Pavlína , Orságh Martin , Pavlova Ewa , Walterová Zuzana , Toman Petr , Kočková Olga , Uchman Mariusz
Published: January 2025

Precise polymer structure: Functionalized gradient diblock copolymers self-assemble into nanoparticles, facilitating drug encapsulation through reversible interactions between copolymer diols and the phenylboronic acid of a metalolacarborane-based model drug.
Precise assembly/disassembly of homo-type and hetero-type macrocycles with photoresponsive and non-photoresponsive dynamic covalent bonds
Authors: Deng Junmiao , Lu Hanwei , Ye Hebo , Hai Yu , Liu Zimu , You Lei
Published: January 2025

Controllable construction and transformation of homo-type and hetero-type macrocycles were achieved through the incorporation of photoresponsive and non-photoresponsive dynamic covalent bonds into single macrocycles.
Understanding the release mechanisms and secretion patterns for glucagon-like peptide-1 using the isolated perfused intestine as a model
Authors: Galsgaard Katrine D. , Modvig Ida M. , Holst Jens J.
Published: January 2025

In the gastrointestinal (GI) tract, food is digested and absorbed while GI hormones are secreted from the enteroendocrine cells (EECs). These hormones regulate food intake, glucose homeostasis, digestion, GI motility, and metabolism. Although EECs may express more than a single hormone, the EECs usually secrete only one or a few hormones. The pattern of EEC secretion varies along the length of the GI tract as the different EEC types are scattered in different densities along the GI tract. Following bariatric surgery, a postprandial hypersecretion of certain GI hormones occurs which contributes to the postsurgery weight loss. Mimicking this postprandial hypersecretion of GI hormones by targeting endogenous EEC secretion, using specific modulators of receptors, ion channels, and transporters found on specific EECs, to induce weight loss is a current research aim. To achieve this, a more complete understanding of the release mechanisms, expression of receptors, transporters, and the secretion pattern of the different EEC types is needed. Using the vascularly perfused intestinal model, it is possible to obtain a detailed knowledge of these release mechanisms by evaluating the effects on secretion of blocking or stimulating specific receptors, ion channels, and transporters as well as evaluating nutrient handling and absorption in each of the different sections of the intestine. This mini-review will focus on how the isolated perfused intestine has been used in our group as a model to investigate the nutrient-induced release mechanisms of EECs with a focus on glucagon-like peptide-1 secreting cells.
Deep circadian‐informed probability refinement network for pedestrian intent classification in urban complex
Authors: Wu Ho Chun , Yuen Paul , Lau Esther Hoi Shan , Hung Kevin , Chui Kwok Tai , Lui Andrew Kwok Fai
Published: January 2025

Urban complexes often feature a mix of commercial, entertainment and recreational space serving a wide range of services. Pedestrian intent classification is hence crucial to identify their different destinations and understanding their needs. Moreover, circadian effects generally influence pedestrian behaviour. This paper proposes a deep circadian‐informed probability refinement network for pedestrian intent classification (CIPRNet). It incorporates circadian information using a multiplexer network architecture to refine preliminary classification probabilities generated by a preliminary deep learning‐based trajectory classifier. A joint loss function is used to co‐optimize both the preliminary baseline trajectory classifier and the CIPRNet. Experimental results using real pedestrian trajectories captured from 3D range sensors at the Osaka Asia and Pacific Trade Centre (ATC) on a sunny day and cloudy day show that the CIPRNet can improve the state‐of‐the‐art prediction of pedestrian paths by long short term memory classifier and trajectory unified transformer by approximately 13% and 10%, respectively. The CIPRNet is also extended to trajectory prediction and it outperformed various state‐of‐the‐art algorithms in terms of average and final displacement error reduction. It may serve as an attractive alternative for pedestrian intent classification for urban complexes.
The compositional diversity of rocky exoplanets around K-dwarf stars
Authors: Hatalova P. , Brodholt J. P. , Brasser R. , Shan Y. , Werner S. C.
Published: January 2025

Context. The mass-radius distribution of currently known exoplanets suggests a fascinating variety in terms of their chemical compositions. Still, the interior structures and compositions of rocky exoplanets are essentially inaccessible to observations. Here, we present a model that combines planet formation simulations with equilibrium condensation models to estimate the interior composition and structure of exoplanets around K-dwarf stars.

Aims. In a previous study, we reproduced the observed population of close-in super-Earths around K-dwarf stars with suitable initial conditions. However, the masses and radii of these simulated planets are not self-consistent, since the radius information is postprocessed based on an assumed constant average density (3 g cm−3). In this work, we have incorporated compositions into the N-body simulations using the chemistry of the protoplanetary disk from equilibrium condensation sequences, together with thermodynamics of the various mineral phases. This has allowed us to develop models of likely interior structures, bulk densities, and, thus, radii for rocky exoplanets.

Methods. We selected the outcomes of ten N-body simulations around a 0.8 M⊙ star that best reproduced the observed population. We employed stellar abundances from six K-dwarf stars with a range of metallicities. Based on the condensation sequence and the temperature-pressure profile of a disk, we assigned bulk elemental compositions to planetesimals and then tracked materials accreted onto planets during their formation.

Results. We have obtained a set of planets with more realistic radii determinations than those purely based on one preset density for all bodies. We formed various types of planets: i) Ca- and Al-rich(er), ii) Mg-depleted, iii) fully oxidized core-less planets, iv) planets similar to Earth or Mars in composition and core size, and v) planets with different core mass fractions (from significantly smaller than the Martian core to significantly larger than the Earth’s core); however, we do not have Mercury-like planet with a huge core.
Insights into the origins of Phobos and Deimos based on a spectral comparison with small bodies and Martian materials
Authors: Wargnier A. , Poggiali G. , Yumoto K. , Fornasier S. , Mahlke M. , Gautier T. , Doressoundiram A.
Published: January 2025

Context. The origins of Phobos and Deimos are highly debated, and several distinct hypotheses have been put forth. The two most widely accepted theories are that (1) the two moons were created by a giant impact in analogy to the Earth-Moon system, whereby a debris disk was formed that then formed the two moons by accretion; and that (2) the moons were captured by the gravitational attraction of Mars.

Aims. To address questions about the origins of the Martian moons, we conducted a systematic search for analogs of Phobos and Deimos among asteroids, Martian terrains, and laboratory data using spectroscopy in the visible, near-infrared, and mid-infrared wavelength ranges.

Methods. We analyzed our dataset using multivariate statistical analysis techniques, namely principal component analysis and t-distributed stochastic neighbor embedding, on the spectral slope derived in various wavelength ranges, and on the albedo. Additionally, a visual comparison of the mid-infrared spectra, focusing on key features such as the Christiansen feature and the Reststrahlen bands, was performed.

Results. The comparison of the spectra of Phobos and Deimos with those of primitive asteroids reveals that the Martian moons exhibit spectroscopic similarities to D- and Z-type asteroids, as well as to Jupiter Trojans, centaurs, and potentially extinct comets. The blue unit on Phobos, generally considered as fresher areas that are mostly seen around the Stickney crater, appears to be spectrally best matched by P-type asteroids. No Martian terrain shows similarities with Phobos and Deimos. It is also notable that the Martian moons exhibit a spectroscopic resemblance to some of the Martian Trojans.

Conclusions. The analysis of available spectral data for asteroids, Mars trojans, and Martian terrains provided a unique opportunity to explore the origins of Phobos and Deimos prior to the arrival of the JAXA/Martian Moon eXploration (MMX) in the Martian system, which is scheduled for 2027. In light of the similarities between the Martian moons and Z-type asteroids, we put forward the hypothesis that Phobos and Deimos may have originated from one or two captured asteroids from the inner main belt, rather than from the outer main belt or the Jupiter trojans, as is often postulated. The formation of Phobos and Deimos may also have occurred simultaneously with that of the Mars trojans. This is a plausible scenario if the formation of the trojans was caused by the impact that created the Borealis basin, although additional processes such as space weathering may be necessary to explain the spectroscopic differences.
Homogenized lattice Boltzmann methods for fluid flow through porous media -- part I: kinetic model derivation
Authors: Simonis Stephan , Hafen Nicolas , Jeßberger Julius , Dapelo Davide , Thäter Gudrun , Krause Mathias
Published: January 2025

In this series of studies, we establish homogenized lattice Boltzmann methods (HLBM) for simulating fluid flow through porous media. Our contributions in part I are twofold. First, we assemble the targeted partial differential equation system by formally unifying the governing equations for nonstationary fluid flow in porous media. A matrix of regularly arranged, equally sized obstacles is placed into the domain to model fluid flow through porous structures governed by the incompressible nonstationary Navier--Stokes equations (NSE). Depending on the ratio of geometric parameters in the matrix arrangement, several homogenized equations are obtained. We review existing methods for homogenizing the nonstationary NSE for specific porosities and discuss the applicability of the resulting model equations. Consequently, the homogenized NSE are expressed as targeted partial differential equations that jointly incorporate the derived aspects. Second, we propose a kinetic model, the homogenized Bhatnagar--Gross--Krook Boltzmann equation, which approximates the homogenized nonstationary NSE. We formally prove that the zeroth and first order moments of the kinetic model provide solutions to the mass and momentum balance variables of the macrocopic model up to specific orders in the scaling parameter. Based on the present contributions, in the sequel (part II), the homogenized NSE are consistently approximated by deriving a limit consistent HLBM discretization of the homogenized Bhatnagar--Gross--Krook Boltzmann equation.
Gastrojejunostomy Catheter Placement and Management
Authors: Gullette Emily , Raja Junaid
Published: January 2025

Gastrojejunostomy catheters are a common means of long-term enteral access in patients unable to meet their nutritional requirements through oral intake. The choice of gastrojejunostomy versus gastrostomy tubes in these patients depends largely on aspiration risk, which is a relative contraindication of gastrostomy placement. Initially a surgical procedure, gastrojejunostomy placement is now frequently performed endoscopically or with radiologic guidance. Additionally, in patients with prior gastrostomy placement who need more distal enteral access, gastrostomy to gastrojejunostomy conversion can easily be performed by an endoscopist or interventional radiologist. This article reviews common techniques for percutaneous radiologic gastrojejunostomy placement, conversion, and exchange, as well as indications and contraindications. Complications will be discussed and compared across the different methods for gastrojejunostomy placement.
Peculiarities in low-temperature heat capacity and parameters of HTS lattice vibrational spectra
Authors: Gurevich A. M. , Dotsenko V. I. , Eropkin V. N. , Telezhenko Yu. V. , Chaikovskaya N. M.
Published: January 2025

The results of measurements of low-temperature (1.5–20 K) heat capacity of HTS samples with successive substitution of metal atoms in different positions are presented. The experimentally observed anomalies can be attributed to a rearrangement of the electronic and magnetic subsystems. The Debye temperatures are calculated, and the boundary frequencies of the acoustic spectrum are evaluated for all the ceramics under investigation.
Magnetic susceptibility of high-T
c superconducting ceramic Tl3Ca7Ba3Cu8O7
Authors: Venttsel’ V. A. , Petrova A. E. , Rudnev A. V.
Published: January 2025

The ac magnetic susceptibility of HTS ceramic Tl3Ca7Ba3Cu8O7 is measured by using the bridge method. The critical parameters Tc = 100 K and Hc1 ≈ 15 Oe are estimated at T→0; below 50 K, Hc2 linearly decreases with temperature [Hc2 = 440-8.4T (kOe)], while above 50 K it decreases according to a power law [Hc2 = 275(1 – T/Tc)3.5 (kOe)]. The Ginzburg-Landau parameter is estimated as x(0) ≃ 300, x(Tc) ≈ 8, and x(T) ∝ x0(1 – T/Tc)1.6.
On the motion of Abrikosov vortices in thin films
Authors: Mel’nikov A. S.
Published: January 2025

Some peculiarities of the resistive state of a thin superconducting film in a magnetic field normal to its surface are considered. It is shown that the resistance emerges due to viscous motion of the Abrikosov vortices. A decrease in the film thickness d leads to a change in the ohmic viscosity, resulting in the resistivity. A deviation in the temperature dependence of resistivity from the power law can be be expected for small values of d.
Laser thermal point-contact spectroscopy of metals
Authors: Balkashin O. P. , Kulik I. I.
Published: January 2025

The response of copper spear–thin film (σ ∼ l μm) point contacts to optical laser radiation (λ = 0.63 μm) is studied at helium temperatures. The point contacts are irradiated both from the spear and the film sides. In the latter case, the contact is influenced by the flow of nonequilibrium thermal phonons generated in the film by the incident light. In both cases, the dependence of the response on a fixed bias voltage is essentially identical to the point-contact spectrum of electron–phonon interaction in copper. The signal amplitude is found to depend significantly on the heat transfer conditions. The obtained experimental data suggest that the observed effect is of the thermal origin. This is supported by the theoretical results. The thermal response of the point contact is analyzed theoretically and the basic concepts of laser thermal spectroscopy are formulated. Data for point contacts with nonballistic current flow modes are also reported.
Frequency oscillations in absorption of microwave electromagnetic field power by YBa2Cu3Ox ceramics
Authors: Dmitriev V. M. , Ofitserov M. N. , Prentslau N. N.
Published: January 2025

The power absorption at frequencies 105−1010 Hz by YBa2Cu3Ox. ceramics with Tc ∼ 91 K is measured at 300 K. Frequency oscillations in the absorption of the microwave electromagnetic field power are found to correlate with the depth of field penetration into the ceramic.
A rotating cryostat for simulation of mechanical, thermal, and hydraulic processes in superconducting rotors
Authors: Babenko F. M. , Gavrilov R. V. , Kirillov E. S. , Korobov V. I. , Pestryakov V. A. , Fedotov A. M. , Tsaran V. P. , Shapoval V. V.
Published: January 2025

An experimental unit consisting of a helium cryostat with a horizontal rotation axis (∼1000 s−1 rotating speed) is described which permits the mechanical, thermophysical, and hydraulic processes in cryogenic superconducting generator rotors to be simulated. Experimental data on nitrogen and helium evaporation rates at different rotational speeds are considered.
High-temperature superconductor thin films: preparation, characterization, and microstructure fabrication
Authors: Habermeier Hanns-Ulrich
Published: January 2025

High-quality thin film cuprate superconductors can be fabricated by different deposition techniques using a variety of substrates including SrTiO3, MgO, LaAlO3, and even semiconducting silicon single crystals, By means of the pulsed laser deposition technique we explore different schemes for crystallization and oxygenation of Y–Ba–Cu–O thin films, such as furnace annealing, rapid thermal annealing, and low-temperature plasma processes, and optimize the thin film quality with respect to Tc, jc surface morphology, and stability. Films on SirTiO3 and LaAlO3 show Tc of 90–92 K and critical currents jc > 106 A/cm2, while films deposited on bare silicon suffer from lower values of jc but still have Tc > 80 K. Degradation problems associated with photolithographic patterning are studied, and these can be overcome using epitaxially grown high density films.
Structural changes of high-T
c superconductors at pressures up to 29 GPa and at temperatures between 15 and 300 K
Authors: Fietz W. H. , Wassilew C. A. , Ludwig H. A. , Obst B. , Dietrich M. R. , Wühl H.
Published: January 2025

The experimental method of X-ray powder diffraction measurements under high pressure is briefly outlined, using a sample containing Yb1Ba2C3O7 (Yb-123) and Yb2Ba1Cu1O5 (Yb-211) as an example. This investigation shows that Yb-123 has a bulk modulus of 155 GPa with linear compressibilities βa = 1.3·10−3 GPa−1, βb = 1.5 ×10−3 GPa−1, and βc = 3.3·10−3 GPa−1. The bulk modulus of the nonsuperconducting Yb-211 is 170 GPa. Measurements of several other high-Tc superconductors and related materials are discussed with respect to structural changes at high pressures. These results show a systematic decrease of the bulk modulus of high-Tc superconductors when going from materials closely related to perovskite (e.g., La1.8Sr0.2CuO4) to materials with an extremely degenerated perovskite structure (e.g., Tl2Ba2Ca2Cu3O10). This change of the bulk modulus is caused mainly by a change in the linear compressibility in the c-axis direction, whereas the linear compressibilities in the a- and b directions for all these materials are similar.
Instability of HTSC properties
Authors: Dikin D. A. , Dmitriev V. M. , Isakina A. P. , Prokhvatilov A. I. , Prikhod’ko O. P. , Khristenko E. V. , Yantsevich L. D.
Published: January 2025

Results are presented on the structural, electrical, and thermodynamic behavior of HTSC materials near the transition to the superconducting state. Time-relaxation anomalies in the temperature dependences of the lattice parameters, molar volumes, thermal expansion coefficients, and heat capacity are revealed. Analysis of literature and present data permits us to conclude that the observed peculiarities and their time relaxations are mainly the consequence of superconducting phase metastabilities which are due to redistribution and ordering of oxygen atoms in heavy-cation layers. Information on the possibility of improving the stability of superconducting ceramics and methods of production of HTSC with Tc > 125 K are presented.
Thermal conductivity of polycrystalline YBa2Cu3O7–x in the range 2–300 K
Authors: Merisov B. A. , Khadzhai G. Ya. , Voronov A. P. , Gavrenko D. A. , Sologubenko A. V.
Published: January 2025

The phonon thermal conductivity of the polycrystalline high-Tc superconductor YBa2Cu2O7–x was studied in the range 2–300 K. The main contribution to the phonon scattering is made by processes in the crystalline grain bulk, and the interparticle boundaries play a secondary role. The phonon heat conductivity maximum is not connected with the electron influence. The thermal conductivity versus temperature behavior is connected with the scattering of “surface” and “bulk” phonons on twin boundaries at low temperatures and with U-processes at high temperatures. Evidence of crystal lattice instability in the sample is observed in the region of superconducting transition.
Raman scattering and luminescence of high-T
c superconducting oxides
Authors: Eremenko V. V. , Gnezdilov V. P. , Formin V. I. , Fugol’ I. Ya. , Samovarov V. N.
Published: January 2025

The Raman and luminescence spectra of high-Tc superconducting oxides are summarized, mainly for YBa2Cu3O7−δ and partly for La2−xBaCuxO4−δ. In the Raman spectra we succeeded in distinguishing electron scattering, in defining the energy gap Δ in the superconducting state, its relation to Tc (r = 2Δ/kBTc = 3.52 ± 0.15), and the temperature dependence Δ(T) = α (1−T/Tc)1/2 which is not inconsistent with the BCS theory. The luminescence spectra are due to the emission of a thin adsorbed layer, atomic with the necessary participation of oxygen and interaction with conduction electrons. The intensities of both the narrow lines (3.36 and 3.31 eV) and the broad continuum (Emax ≃ 2.7 eV) are sensitive to the SN transition which makes it possible to suggest a new diagnostic method for the SC phase.
Acoustic impedance and correlation length in He II near the λ-point
Authors: Palagin A. V. , Sobyanin A. A.
Published: January 2025

The problem of acoustic impedance in He II near the λ-point is considered taking into account nonuniform distribution of the viscosity and density of the normal component. A method of correct determination of the correlation length from experimental data [M. J. Lea et al., Phys. Rev. B39, 6527 (1989)] is presented.
Second sound in superfluid 3He–4He solutions
Authors: Adamenko I. N. , Nemchenko K. É. , Tsyganok V. I.
Published: January 2025

Second sound is studied in the solutions in a wide temperature range where the contribution from all quasiparticles (phonons, rotons and impuritons) and frequencies should be taken into account. A dispersion relation is derived, which describes various modes of equilibrium setting-in in the phonon system. The velocity and the coefficient of absorption of second sound are calculated in hydrodynamic, kinetic and transient regimes. The results of calculations are compared with experimental data.
On the heterogenization conditions in YBa2Cu3O7–δ
Authors: Olemskoi A. I. , Slezov V. V. , Kul’ment’ev A. I.
Published: January 2025

The conditions of realization of a heterogeneous state (HS) in the superconducting compound YBa2Cu3O7–δ are analyzed. The width of the region of existence of HS on the phase diagram is determined and spatial characteristics of HS structure are specified. The results are compared with experimental data.
The effects of intramolecular vibrations in point-contact spectra of organic superconductor β-(BEDT–TTF)2I3
Authors: Kamarchuk G. V. , Pokhodnya K. I. , Khotkevich A. V. , Yanson I. K.
Published: January 2025

Point heterocontacts between a quasi-two-dimensional organic superconductor β-(BEDT–TTF)2I3 and a noble metal (copper, silver) are investigated, and current–voltage characteristics and their second derivatives are measured. The peak observed in the normal state on the second derivatives of current–voltage characteristics in the region of 50 meV is due to the interaction of charge carriers with intramolecular vibrations of BEDT–TTF (donor) in the organic metal. A transition to heterojunctions with a superconducting inclusion is observed at T = 4.2 K with increasing confining force between the electrodes. The values of the energy gap for the organic superconductor and the excess current of the heterojunctions are calculated.
Low-temperature phase transitions and collective excitations in a singlet magnet
Authors: Zubov É. E. , Krivoruchko V. N.
Published: January 2025

Green’s function diagrammatic technique is used to study phase transitions in a singlet ferromagnet (S = 1) over a wide range of values of transverse magnetic field and temperature. The T–H and T–D phase diagrams are constructed in the first order with respect to the reciprocal effective radius of interaction. Theoretical and experimental T–H phase diagrams are compared for the NiSiF6·6H2O singlet magnet. It is shown that fluctuations may result in a considerable renormalization of the phase transition temperature. The spectrum and damping of collective excitations in the paramagnetic phase of a low-temperature magnet are discussed.
Effect of oxygen deficiency on the low-temperature peculiarities of the velocity of sound in YBa2Cu3O7–δ
Authors: Gaiduk A. L. , Gasan V. M. , Demirskii V. V. , Zherlitsyn S. V. , Kolobov I. G. , Tabachnikova E. D. , Fil’ V. D.
Published: January 2025

The behavior of the velocity of sound is investigated in the region of low temperatures under various thermal treatments leading to a change in the oxygen content. It is found that the temperature dependence is nearly linear and its slope correlates with the oxygen deficit in the YBa2Cu3O7–δ samples. Obviously, this paves the way for developing a method to monitor the oxygen deficit in bulk samples of yttrium ceramics.