bluuebunny/crossref_metadata_2025_split huggingface dataset:
Feature fusion Siamese network for breast cancer detection comparing current and prior mammograms
Authors: Bai Jun , Jin Annie , Wang Tianyu , Yang Clifford , Nabavi Sheida 
Published: March 2022

AbstractPurposeAutomatic detection of very small and nonmass abnormalities from mammogram images has remained challenging. In clinical practice for each patient, radiologists commonly not only screen the mammogram images obtained during the examination, but also compare them with previous mammogram images to make a clinical decision. To design an artificial intelligence (AI) system to mimic radiologists for better cancer detection, in this work we proposed an end‐to‐end enhanced Siamese convolutional neural network to detect breast cancer using previous year and current year mammogram images.MethodsThe proposed Siamese‐based network uses high‐resolution mammogram images and fuses features of pairs of previous year and current year mammogram images to predict cancer probabilities. The proposed approach is developed based on the concept of one‐shot learning that learns the abnormal differences between current and prior images instead of abnormal objects, and as a result can perform better with small sample size data sets. We developed two variants of the proposed network. In the first model, to fuse the features of current and previous images, we designed an enhanced distance learning network that considers not only the overall distance, but also the pixel‐wise distances between the features. In the other model, we concatenated the features of current and previous images to fuse them.ResultsWe compared the performance of the proposed models with those of some baseline models that use current images only (ResNet and VGG) and also use current and prior images (long short‐term memory [LSTM] and vanilla Siamese) in terms of accuracy, sensitivity, precision, F1 score, and area under the curve (AUC). Results show that the proposed models outperform the baseline models and the proposed model with the distance learning network performs the best (accuracy: 0.92, sensitivity: 0.93, precision: 0.91, specificity: 0.91, F1: 0.92 and AUC: 0.95).ConclusionsIntegrating prior mammogram images improves automatic cancer classification, specially for very small and nonmass abnormalities. For classification models that integrate current and prior mammogram images, using an enhanced and effective distance learning network can advance the performance of the models.
Supramolecular p/n‐heterojunction of C60‐functionalized bis(merocyanine) quadruple stack: A model system for charge carrier separation and recombination in organic solar cells
Authors: Bialas David , Fennel Franziska , Noll Niklas , Holzapfel Marco , Schmiedel Alexander , Lambert Christoph , Würthner Frank 
Published: March 2022

AbstractSupramolecular photosystems can afford important insights into elementary processes in molecular materials. Here, a bis(merocyanine)‐C60 conjugate composed of two covalently tethered electron‐donating merocyanine chromophores and two appended fullerene electron acceptor units is investigated. Concentration‐dependent UV/Vis studies in nonpolar solvents revealed a bimolecular association (dimerization) process, resulting in the formation of an H‐coupled merocyanine dye aggregate. The aggregate structure was confirmed by 2D NMR spectroscopy proving the presence of a well‐defined quadruple dye stack surrounded by four loosely connected fullerenes, which mimics the donor–acceptor interface in bulk heterojunction (BHJ) solar cells. Due to the interdigitation of the dyes in the quadruple stack motif, even at low concentrations, fully aggregated species prevail in nonpolar solvents, which enabled us to elucidate the photophysics of this supramolecular p/n‐heterojunction in dilute solution by femtosecond time‐resolved transient absorption spectroscopy. The observed photophysical processes include a favorably fast photoinduced electron transfer from the electron‐donating dye stack to the electron‐accepting fullerene moieties, a slower geminate charge carrier recombination of the generated electron and hole in the supramolecular p/n‐heterojunction as well as the formation of fullerene triplet states. While the geminate recombination of charge carriers is supposed to be less competitive in BHJ photovoltaic materials due to the possibility of fast electron migration within fullerene domains in thin films, intersystem crossing into the triplet manifold appears as a more critical undesired process. These insights from spectroscopy may help to tailor improved photovoltaic materials, thereby demonstrating the value of fundamental studies on elementary photophysical processes in molecular aggregates.KEY POINTS
Supramolecular p/n‐heterojunction by self‐assembly in solution
Aggregate structure confirmed by NMR spectroscopy
Photoinduced electron transfer studied by transient absorption spectroscopy
A new ϕ‐FEM approach for problems with natural boundary conditions
Authors: Duprez Michel , Lleras Vanessa , Lozinski Alexei 
Published: March 2022

AbstractWe present a new finite element method, called ‐FEM, to solve numerically elliptic partial differential equations with natural (Neumann or Robin) boundary conditions using simple computational grids, not fitted to the boundary of the physical domain. The boundary data are taken into account using a level‐set function, which is a popular tool to deal with complicated or evolving domains. Our approach belongs to the family of fictitious domain methods (or immersed boundary methods) and is close to recent methods of CutFEM/XFEM type. Contrary to the latter, ‐FEM does not need any nonstandard numerical integration on cut mesh elements or on the actual boundary, while assuring the optimal convergence orders with finite elements of any degree and providing reasonably well conditioned discrete problems. In the first version of ‐FEM, only essential (Dirichlet) boundary conditions was considered. Here, to deal with natural boundary conditions, we introduce the gradient of the primary solution as an auxiliary variable. This is done only on the mesh cells cut by the boundary, so that the size of the numerical system is only slightly increased. We prove theoretically the optimal convergence of our scheme and a bound on the discrete problem conditioning, independent of the mesh cuts. The numerical experiments confirm these results.
Effect of Protrusion on Combustion Stability of Hybrid Rocket Motor
Authors: Dinesh Mengu , Kumar Rajiv 
Published: March 2022

AbstractIn hybrid rockets, low regression rate and low combustion efficiency are major drawbacks restricting its utilization in practical applications. Inserting a protrusion in a hybrid rocket combustion chamber is one of the methods to enhance the regression rate and combustion efficiency. In the present study, while utilizing the protrusion method the combustion stability of the hybrid rocket was investigated. The protrusions used for this study were of two different types; one was made of graphite and another one was nylon. The nylon protrusion can regress during the combustion along with the fuel whereas, graphite cannot. Before using the protrusion method, the combustion stability of the hybrid rocket motor (base case) was characterized. During the combustion of the base case motor, intense pressure oscillations were observed for a definite period after the beginning of the combustion. These oscillations were found to be the result of the interaction between the vortex shedding and fundamental longitudinal acoustic modes of the chamber at the fuel grain exit. Upon inserting the protrusion near the fuel grain exit, significant suppression in the pressure oscillations was observed. A 96 % reduction in amplitude of acoustic modes relative to the base case was observed. There was no substantial difference in combustion stability of the hybrid rocket when using graphite or nylon protrusions. Further, it was realized that the combustion stability of the rocket motor remains unchanged even after varying the thickness of the protrusion at 0.8X/L location.
Detection of glutathione, cysteine, and homocysteine by online derivatization‐based electrospray mass spectrometry
Authors: Yin Yiyan , Zhen Boyu , Sun Jianghui , Ouyang Jin , Na Na 
Published: March 2022

RationaleElectrospray ionization mass spectrometry (ESI‐MS) is one of the most popular techniques for obtaining structural information, which is commonly used in bioanalysis and clinical diagnostics. However, for the detection of complicated samples with high reactivities (such as reactive sulfur species, RSS), traditional ESI‐MS usually suffers from overlapped and inaccurate signals. In this study, based on the multiphase flow of extractive electrospray ionization (MF‐EESI), an ambient MS technique of online derivatization was proposed to detect thiols without any other sample pretreatment.MethodsRSS molecules and the derivatization reagent of 4‐chloro‐7‐nitro‐1,2,3‐benzoxadiazole (NBD‐Cl) were introduced into the internal and innermost capillary of the MF‐EESI system, respectively. By a high‐velocity nebulizing stream of N2 gas through an external capillary, both flows of innermost biothiols and internal NBD‐Cl were electrosprayed and mixed for online reactions. Therefore, the fast derivatization of thiols was used to generate stable ionized derivatives for MS detection.ResultsBy evaluating the changes in MS signals before and after the derivatization, the ions of RSS were identified simply and correctly. Without any sample pretreatment, the fast detection of cysteine, homocysteine, and glutathione has been achieved in the complicated samples.ConclusionsThe present online derivatization‐based MF‐EESI was successfully used for fast, simple, and accurate detection of biothiols. This presented a potential pathway for the fast identification of thiols in complicated samples.
A case of pulmonary thromboembolism possibly associated with the use of creatine supplements
Authors: Lee So Hyun , Seo Jin A , Park Ji Eun , Kim Chang Ho , Lee Jaehee 
Published: March 2022

AbstractDrug administration should be considered a risk factor for venous thromboembolism (VTE) in younger healthy patients. We present a case of new‐onset pulmonary embolism (PE), possibly associated with excessive creatine supplement intake. A 24‐year‐old non‐smoker male presented to the emergency department with sudden‐onset dyspnoea and chest discomfort. Computed tomography pulmonary angiography and venography confirmed PE in the left and right pulmonary artery branches and a thrombus in the left popliteal vein. The patient had no family history of VTE, and other causes of thrombophilia were unlikely. He reported a recent increase in the intensity of his workouts and the dose of his creatine supplements in preparation for a bodybuilding competition. The creatine supplements likely promoted dehydration during intense workouts and profuse sweating. He received anticoagulation therapy, and the creatine supplements were discontinued. Creatine supplements should be used cautiously when there is a higher risk of becoming dehydrated.
Accumulation of fibrosis and altered perifollicular stromal differentiation in vitrified‐thawed human ovarian tissue xenografted to nude mice.
Authors: Kitajima Michio , Murakami Naoko , Kitajima Yuriko , Kajimura Itsuki , Matsumura Asako , Matsumoto Kanako , Harada Ayumi , Miura Kiyonori 
Published: March 2022

AbstractPurposeOvarian tissue cryopreservation and its auto‐transplantation is promising technique in fertility preservation. Longevity of grafted tissue is limited though mechanism of follicle reduction is not fully understood. We evaluated histological alteration of vitrified‐thawed ovarian tissue that grafted to nude mice.Materials and MethodsHuman ovarian tissue was cryopreserved by vitrification. After thawing, they were grafted to mesentery of nude mice. Twelve weeks after transplantation, the implants were removed and histologically examined. The presence of follicles, the degree of fibrosis, and TUNEL staining in surrounding cortex were evaluated. The stromal expressions of alpha‐smooth muscle actin (aSMA) were determined.ResultsNormal ovarian cortex was decreased, and fibrotic area were significantly increased after grafting. The distributions of developmental stage of follicles shifted toward activation of follicular growth. Stromal TUNEL staining was increased in frozen/thawed tissue. The expression of aSMA were found in perifollicular stroma of growing follicles, which were decreased in grafted tissue associated with reduction of cortical stroma.ConclusionsFibrosis, reduced cortical stroma, and activation of dormant follicles were concomitantly observed in grafted ovarian cortex, which may relate to limited longevity. Perifollicular aSMA expression can be regarded as a marker of the competence of cortical stroma that regulate follicular development.
Revealing the revealed preferences of public firm CEOs and top executives: A new database from credit card spending
Authors: Raffiee Joseph , Fehder Daniel , Teodoridis Florenta 
Published: March 2022

AbstractResearch SummaryWe introduce a new database which provides an unprecedented window into the off‐the‐job lives and interests of public firm top executives as reflected by their personal income allocation. We construct this database by matching household credit card spending data with the population of executives in Execucomp. To overcome the significant computational challenges associated with matching these data, we build on the statistical record‐linking literature in a way that allows us to generate reliable matches with limited information. To facilitate research exploring new questions made possible with this database, we make our matching crosswalk freely available for academic use.Managerial SummaryThis article describes the matching procedures associated with the development of a database which sheds new light on the revealed preferences of public firm top executives. Prior work on upper echelons has routinely stressed how preferences and characteristics of top executives often manifest in firm behaviors and are important predictors of firm outcomes. Nevertheless, the lack of a reliable paper trail capturing executive preferences, particularly at a large scale, has been a friction slowing comprehensive empirical research on this topic. We describe how we address this limitation by linking top executives listed in the database Execucomp with credit card spending data provided by the consumer data provider L2 and outline a number of new research questions made possible by our matching efforts. The results of our matching efforts (Execucomp‐L2 unique identifier crosswalk) are available at https://github.com/dfehder/FRT_2022_SMJ_CEO_TopExec_Preferences.
Synthesis and Catalytic Property of Ribonucleoside‐Derived Carbon Dots
Authors: Li Shuai , Li Feng , Dong Yuhang , Song Nachuan , Pan Li , Yang Dayong 
Published: March 2022

AbstractExploring appropriate precursors has been proposed to be a promising strategy for the creation of artificial enzymes that are emerging as alternatives of natural enzymes. Herein, inspired by the catalytic activities of ribose nucleic acid, using ribonucleosides as precursors including adenosine, guanosine, cytidine, and uridine, respectively, four carbonic aggregates, namely, carbon dots (A‐CDs, G‐CDs, C‐CDs, and U‐CDs) to mimic artificial enzymes are synthesized. All the CDs show a planar graphene‐like structure and thus can intercalatively bind with DNA double helix. Different from the other three CDs, the uridine‐derived U‐CDs exhibit unique catalytic property, which can mediate the topological transformation of DNA from supercoiled to nicked open‐circular conformation. U‐CDs can catalyze oxidation of O2 to generate singlet oxygen 1O2 via a Haber–Weiss reaction, and consequently mediate oxidative cleavage of phosphate backbone in DNA and release the torsional energy stored in supercoiled DNA. Explorations reveal that the unique highly active oxygenated species, namely, quinone groups that are on the edge of U‐CDs, play a key role in the catalytic production of 1O2. This work represents a new insight that using natural biomolecules in living systems as precursors can create new species beyond life.
Engineering Hierarchical Architecture of Metal‐Organic Frameworks for Highly Efficient Overall CO2 Photoreduction
Authors: Huang Hai‐Bo , Fang Zhi‐Bin , Wang Rui , Li Lan , Khanpour Mojtaba , Liu Tian‐Fu , Cao Rong 
Published: March 2022

AbstractPrevious studies on syntheses of metal‐organic frameworks (MOFs) for photocatalytic CO2 reduction are mainly focused on the exquisite control over the net topology and the functionality of metal clusters/organic building blocks. This contribution demonstrates that the rational design of MOF‐based photocatalyst can be further extended to the hierarchical structure at micrometer scales well beyond the conventional MOF design at the molecular level. By taking advantage of the disparity of two selective MOFs in nucleation kinetics, a hierarchical core–shell MOF@MOF structure is successfully constructed through a simple one‐pot synthesis. Besides inheriting the high porosity, crystallinity, and robustness of parent MOFs, the obtained heterojunction exhibits extended photoresponse, optimized band alignment with large overpotential, and greatly enhanced photogenerated charge separation, which would be hardly realized by the merely molecular‐level assembly. As a result, the challenging overall CO2 photoreduction is achieved, which generates a record high HCOOH production (146.0 µmol/g/h) without using any sacrificial reagents. Moreover, the core–shell structure exhibits a more effective use of photogenerated electrons than the individual MOFs. This work shows that harnessing the hierarchical architecture of MOFs present a new and effective alternative to tuning the photocatalytic performance at a mesoscopic level.
Gut microbiota and inflammatory bowel disease
Authors: Chen Liang , Wang Jun 
Published: March 2022

AbstractGut microbiota refers to the complex aggregation of microbes in gut, including bacteria, archaea, fungi, and viruses, and they exert marked influence on the host's health. Perturbations in the gut microbiota have been closely linked to initiation and progression of IBD, which has become a disease with accelerating incidence worldwide, but it remains to be thoroughly investigated how microbial involvement might contribute to IBD. In this review, we discuss the current research findings concerning alterations in the gut microbiota, trans‐kingdom interaction between the members of the gut microbiota, their interactions with the immune system of host, their potential role in the IBD pathogenesis, and the relationship between gut microbiota and IBD. We hope to provide a better understanding of the causes of IBD and shed light on the development of microbiome‐based therapeutic approaches, which might be a promising strategy to alleviate, manage, and eventually cure IBD.This article is categorized under:
Infectious Diseases > Genetics/Genomics/Epigenetics
Infectious Diseases > Molecular and Cellular Physiology
On uniqueness and stability for the Boltzmann–Enskog equation
Authors: Friesen Martin , Rüdiger Barbara , Sundar Padmanabhan 
Published: March 2022

AbstractThe time-evolution of a moderately dense gas in a vacuum is described in classical mechanics by a particle density function obtained from the Boltzmann–Enskog equation. Based on a McKean–Vlasov equation with jumps, the associated stochastic process was recently constructed by modified Picard iterations with the mean-field interactions, and more generally, by a system of interacting particles. By the introduction of a shifted distance that exactly compensates for the free transport term that accrues in the spatially inhomogeneous setting, we prove in this work an inequality on the Wasserstein distance for any two measure-valued solutions to the Boltzmann–Enskog equation. As a particular consequence, we find sufficient conditions for the uniqueness and continuous-dependence on initial data for solutions to the Boltzmann–Enskog equation applicable to hard and soft potentials without angular cut-off.
Prognosemodelle zur Steuerung von intensivmedizinischen COVID-19-Kapazitäten in Deutschland
Authors: Grodd Marlon , Refisch Lukas , Lorenz Fabian , Fischer Martina , Lottes Matthäus , Hackenberg Maren , Kreutz Clemens , Grabenhenrich Linus , Binder Harald , Wolkewitz Martin 
Published: March 2022

Zusammenfassung
Hintergrund
Zeitdynamische Prognosemodelle spielen eine zentrale Rolle zur Steuerung von intensivmedizinischen COVID-19-Kapazitäten im Pandemiegeschehen. Ein wichtiger Vorhersagewert (Prädiktor) für die zukünftige intensivmedizinische (ITS-)COVID-19-Bettenbelegungen ist die Anzahl der SARS-CoV-2-Neuinfektionen in der Bevölkerung, die wiederum stark von Schwankungen im Wochenverlauf, Meldeverzug, regionalen Unterschieden, Dunkelziffer, zeitabhängiger Ansteckungsrate, Impfungen, SARS-CoV-2-Virusvarianten sowie von nichtpharmazeutischen Eindämmungsmaßnahmen abhängt. Darüber hinaus wird die aktuelle und auch zukünftige COVID-ITS-Belegung maßgeblich von den intensivmedizinischen Entlassungs- und Sterberaten beeinflusst.

Methode
Sowohl die Anzahl der SARS-CoV-2-Neuinfektionen in der Bevölkerung als auch die intensivmedizinischen COVID-19-Bettenbelegungen werden bundesweit flächendeckend erfasst. Diese Daten werden tagesaktuell mit epidemischen SEIR-Modellen aus gewöhnlichen Differenzialgleichungen und multiplen Regressionsmodellen statistisch analysiert.

Ergebnisse
Die Prognoseergebnisse der unmittelbaren Entwicklung (20-Tage-Vorhersage) der ITS-Belegung durch COVID-19-Patienten*innen werden Entscheidungsträgern auf verschiedenen überregionalen Ebenen zur Verfügung gestellt.

Schlussfolgerung
Die Prognosen werden der Entwicklung von betreibbaren intensivmedizinischen Bettenkapazitäten gegenübergestellt, um frühzeitig Kapazitätsengpässe zu erkennen und kurzfristig reaktive Handlungssteuerungen, wie etwa überregionale Verlegungen, zu ermöglichen.
Converting sounds to meaning with ventral semantic language networks: integration of interdisciplinary data on brain connectivity, direct electrical stimulation and clinical disconnection syndromes
Authors: Sefcikova Viktoria , Sporrer Juliana K. , Juvekar Parikshit , Golby Alexandra , Samandouras George 
Published: March 2022

AbstractNumerous traditional linguistic theories propose that semantic language pathways convert sounds to meaningful concepts, generating interpretations ranging from simple object descriptions to communicating complex, analytical thinking. Although the dual-stream model of Hickok and Poeppel is widely employed, proposing a dorsal stream, mapping speech sounds to articulatory/phonological networks, and a ventral stream, mapping speech sounds to semantic representations, other language models have been proposed. Indeed, despite seemingly congruent models of semantic language pathways, research outputs from varied specialisms contain only partially congruent data, secondary to the diversity of applied disciplines, ranging from fibre dissection, tract tracing, and functional neuroimaging to neuropsychiatry, stroke neurology, and intraoperative direct electrical stimulation. The current review presents a comprehensive, interdisciplinary synthesis of the ventral, semantic connectivity pathways consisting of the uncinate, middle longitudinal, inferior longitudinal, and inferior fronto-occipital fasciculi, with special reference to areas of controversies or consensus. This is achieved by describing, for each tract, historical concept evolution, terminations, lateralisation, and segmentation models. Clinical implications are presented in three forms: (a) functional considerations derived from normal subject investigations, (b) outputs of direct electrical stimulation during awake brain surgery, and (c) results of disconnection syndromes following disease-related lesioning. The current review unifies interpretation of related specialisms and serves as a framework/thinking model for additional research on language data acquisition and integration.