bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Process Parameters on Chip Morphology When Machining Hardened Steel
Authors: Kishawy Hossam. A. , Elbestawi Mohamed. A.
Published: March 2022

This paper presents an experimental study of the effect of process parameters on chip morphology when machining hardened steel. Cutting tests are performed using ceramic inserts at (90–200) m/min cutting speed, (0.01–0.2) mm feed and (0.2–4) mm depth of cut. The chips obtained are examined using SEM and optical microscope. The effect of tool wear and different combinations of cutting speed and feed on chip morphology are studied. In addition, the effects of cutting conditions on chip segmentation frequency are investigated. Microhardness tests are also performed on the chips collected at different cutting conditions. The results obtained show that the cutting process parameters alter significantly the chips microhardness distribution.
Numerical and Experimental Analysis of Orthogonal Metal Cutting
Authors: Kalhori Vahid , Lundblad Mikael , Lindgren Lars-Erik
Published: March 2022

This paper presents experimental results which can be used for evaluating computational models to assure robust solutions. The general finite element code ABAQUS/Standard has been used in the simulations. A quasi-static simulation with adiabatic heating was performed. The path for separating the chip from the work piece is predetermined. The agreement between measurements and calculation is good considering the simplifications introduced. Still, some capabilities are lacking in ABAQUS. Work is continuing in order to create and evaluate more advanced computational models.
The Bending Moment as the Cause of Chip Formation
Authors: Astakhov Viktor P. , Shvets Stanislav V. , Osman M. O. M.
Published: March 2022

This paper presents a new study of chip formation in orthogonal cutting. The work has shown that the known model of chip formation based on the analytical description of the shear process alone has already reached its maximum development and still matches practical results only occasionally. Therefore, the further progress in the cutting theory may be achieved only by introducing some other mechanisms to account for the phenomena in the deformation zone. Naturally, this new mode of deformation should be considered together with shearing to explain the chip formation. This paper aims to introduce the bending moment as a cause of chip formation. The presence and the significance of the bending moment in the chip formation process have been demonstrated both theoretically and experimentally.
Role of Unloading in Machining of Brittle Materials
Authors: Chandra A. , Wang K. , Huang Y. , Subhash G.
Published: March 2022

A simple stress based defect evolution model is developed to assess the influence of various process paramters on material removal rate (MRR) and induced damage during ceramic grinding processes. Model predictions for normal and lateral damage zones under normal indentations are first compared to fracture models as well as experimental observations on pyrex glass. The proposed model is then extended to simulate oblique indentation events depicting abrasive gritworkpiece interactions during ceramic grinding. It is also easily extendable to real grinding situations involving multiple interacting abrasive grits. Process design options for reducing induced damage in the finished part, and increasing MRR are considered next. In particular, the potential of a new design avenue involving intermittent unloading is investigated. For pyrex glass, it is observed that intermittent unloading can facilitate significant increase in force per abrasive grit without increasing the associated surface and sub-surface fragmentation in the finished part. This design feature may enable significant increase in MRR, while maintaining a very low level of process induced damage in the finished product.
Material Constitutive Modeling Under High Strain Rates and Temperatures Through Orthogonal Machining Tests
Authors: Lei Shuting , Shin Yung C. , Incropera Frank P.
Published: March 2022

This paper presents a procedure to characterize deformation behavior applicable to various engineering materials in machining processes. Orthogonal machining tests are used to obtain the relationship between shear stress, strain, strain rate and temperature. Shear plane temperature is measured by an infrared thermal imaging system and compared with the Loewen and Shaw model. A new procedure to determine strain rate in the shear zone is proposed based on a triangular shear zone model and grain boundary determined by optical microscopy. Finally, a constitutive model for a low carbon steel, determined by the procedure, is presented and compared with existing results.
An Improved Analytical Modeling of Force System in Ball-End Milling
Authors: Lazoglu Ismail , Liang Steven Y.
Published: March 2022

The objective of this paper is to present a comprehensive algebraic model for better understanding of the cutting force system in the ball-end milling process. This objective is accomplished by analytically formulating the dominant dynamic components of three dimensional cutting forces in the machining of parts with helical multi-flute ball-end milling cutters. In this formulation, the effects of tool geometry, material characteristics, machining configurations, cutter-workpiece interactions, process parameters are quantitatively and explicitly presented. In this improved formulation, the axis inclination in the generation of 3-D sculpture surfaces is also incorporated to the force model, and the cutting force coefficients are predicted from the average chip thickness.
Tool Wear Characteristics of CBN Tools in the Finish Machining of Tool Steels
Authors: Sista Prasad S. , Swain Selden O. , Chandrasekar Srinivasan , Farris Thomas N.
Published: March 2022

A study has been made of the wear characteristics of CBN tools in the dry and wet finish machining of M2 tool steel, heat treated to a hardness of 60–62 Rc. The repeatability of CBN tool flank wear, the Taylor tool life exponent for CBN tools, the effect of coolant on tool wear and tool life, and the variation of component surface finish and cutting forces with tool wear have been measured. It is found that the evolution of tool wear is very repeatable, the Taylor tool life exponent for CBN tools is 0.26 in dry finish machining and that the use of a coolant leads to a 20–25% increase in tool life. The variation of surface finish with flank wear is also observed to be qualitatively similar in multiple cutting experiments carried out at the same conditions in dry and wet machining. The machining forces show a steady increase with flank wear with the radial force showing the greatest increase. The specific cutting energy for the CBN finish machining of M2 steel has been estimated and it is found to be about 10 times smaller than the specific grinding energy.
A 3-D Kinematic Model of Complex Chip Curling With Chip Breaker Tools in Metal Cutting: Part II — Analysis and Discussion
Authors: Fang Y. J. , Basu A. , Fang X. D.
Published: March 2022

Based on the 3-D analytical model of chip curling developed in the part I of this paper [1], a systematically theoretical analysis and further discuss have been done in this part by differentiating the model with respect to three chip angular velocity components ωx, ωy, ωz and chip flow angle η0 for the effects of the three chip angular velocity components. Based on the analysis, a group of criterions for the effects of ωx, ωy, ωz and η0 on the chip forms/shapes is obtained, and the varying tendency of the chip radius and chip pitch with varying ωx, ωy, ωz and η0 is discussed based on the group of criterions. Further, for better understanding, a group of 3-D diagrams has been given in order to visualise the varying tendency of the chip forms/shapes with the three chip angular velocity components and chip flow angle. The results of the analysis and discussion reveal that the chip twisting is an effective approach to chip breaking, specially for the thin chip breaking. These are significant in theory to direct the geometric design of the chip breaker/groove and effective control of chip breaking process.
Delayed Resonance Yields a New Perspective on Regenerative Machine Tool Chatter
Authors: Olgac Nejat , Hosek Martin
Published: March 2022

A well known phenomenon, regenerative machine tool chatter, is studied from an unconventional perspective. The fundamental reason for this undesired sustained oscillation is the selection of the cutting parameters such that the tool/workpiece interface acts like a resonator. Pure time delay which appears in the governing dynamics yields transcendental characteristic equations which possess infinitely many roots. The dominant roots among them should be searched. This work addresses the problem with a parallelism to a recent active vibration absorption methodology: the Delayed Resonator. Pursuing the root locus plot analysis it can be shown that the chatter can be reached for any cutting speed for a particular chip property. Very critically, we show that there are speed and chip width settings which yield regenerative chatter with dual frequencies. This particular feature parallels the basic claim of a recently patented technique for dual frequency vibration suppression.
Stability Analysis in Face Milling Operations: Part 1 — Theory of Stability Lobe Prediction
Authors: Jensen Steve A. , Shin Yung C.
Published: March 2022

This paper involves development of an algorithm to predict stability lobes in face milling operation. The modeling is based on frequency domain analysis and is comprehensive. It considers the effects of insert and cutter geometry, cutting conditions, process non-linearity, entry and exit angles and the fully dimensional structural dynamics of both the machine tool and workpiece, including axial dynamics which are often neglected by many researchers. In addition, the predictive capability of stability lobes by the presented models is compared with those results obtained by time domain simulations.
A Methodology for Early Front End Structural Design to Meet Safety Requirements Using CAE Tools
Authors: Wang Han , Johnson David , Hammoud Hassen , Bakkar Jamal
Published: March 2022

A methodology was developed to design the front end structure of a car with a short front-end to meet Frontal Impact safety requirements. The methodology is based on CAE tools, and it is to be applied in the early stages of the design process. It includes setting the vehicle target pulse, obtaining the component targets, designing the structural components and sub-systems, and evaluating the vehicle system by Finite Element analysis. The process is based in two CAE tools, an FCRASH Finite Element Hybrid model for the structural analysis, and a MADYMO model for the occupant simulation. The Hybrid model was chosen for the structural analysis in order to allow the upgrade of the CAE model during the different stages of the design process. Modifications of the process are discussed in order to meet different crash requirements.
Vehicle Interior Head Impact Simulations Using FCRASH
Authors: Barbat Saeed D. , Chou Clifford C.
Published: March 2022

The development of a finite element deformable featureless headform model for vehicle upper interior head impact simulations is described in this paper. The model and the head impact prediction methodology are developed using the FCRASH finite element code developed by Ford Motor Company. The model uses a visco-elastic material law which is implemented in FCRASH to simulate the vinyl skin response during impact. The constitutive parameters of the headform’s skin are calibrated through comparison of head drop simulations at various impact speeds with the corresponding tests. The predictions of the headform responses in drop tests at impact speeds of 2.68, 4.02, 5.36 and 6.71 m/s (6, 9, 12 and 15 mph) are in excellent agreement with related experiments.

In addition, the head impact prediction methodology development entails validations of simulation results against the test data in both component and full vehicle system environments. Interior head impacts at various locations on A-pillar, B-pillar, header and side rail are simulated. Comparisons of the predicted results with test data in terms of peak accelerations, Head Injury Criterion (HIC) and deceleration waveforms with test results are in close agreements. Application of this CAE tool to predict head impact response during product development is essential. Attribute trade-off study, and evaluations of A-pillar trim design alternatives and material candidates and identifying countermeasures for improved head impact protection are demonstrated. It is concluded that the developed head impact simulation methodology is capable of predicting the head response and HIC calculations during headform impact with vehicle upper interior.
Application of the Thermal Network Method to the Transient Thermal Analysis of Multichip Modules
Authors: Ishizuka Masaru , Iwasaki Hideo
Published: March 2022

In recent years, there is a growing demand to have smaller and lighter electronic circuits which have greater complexity, multifunctionality and reliability. High-density multichip packaging technology has been used in order to meet these requirements. The higher the density scale is, the larger the power dissipation per unit area becomes. Therefore, in the designing process it has become very important to carry out the thermal analysis. However, the heat transport model in multichip modules is very complex and its treatment is tedious and time consuming. This paper describes an application of the thermal network method to the transient thermal analysis of multichip modules and proposes a simple model for the thermal analysis of multichip modules as a preliminary thermal design tool. Based on the result of transient thermal analysis, the validity of the thermal network method and the simple thermal analysis model are confirmed.
The Record Power Profile of Male Professional Cyclists: Fatigue Matters
Authors: Mateo-March Manuel , Valenzuela Pedro L. , Muriel Xabier , Gandia-Soriano Alexis , Zabala Mikel , Lucia Alejandro , Pallares Jesús G. , Barranco-Gil David
Published: March 2022

Purpose: The present study aimed to determine the influence of fatigue on the record power profile of professional male cyclists. We also assessed whether fatigue could differently affect cyclists of 2 competition categories. Methods: We analyzed the record power profile in 112 professional cyclists (n = 46 and n = 66 in the ProTeam [PT] and WorldTour [WT] category, respectively; age 29 [6] y, 8 [5] y experience in the professional category) during 2013–2021 (8 [5] seasons/cyclist). We analyzed their mean maximal power (MMP) values for efforts lasting 10 seconds to 120 minutes with no fatigue (after 0 kJ·kg−1) and with increasing levels of fatigue (after 15, 25, 35, and 45 kJ·kg−1). Results: A significant (P < .001) and progressive deterioration of all MMP values was observed from the lowest levels of fatigue assessed (ie, −1.6% to −3.0% decline after 15 kJ·kg−1, and −6.0% to −9.7% after 45 kJ·kg−1). Compared with WT, PT cyclists showed a greater decay of MMP values under fatigue conditions (P < .001), and these differences increased with accumulating levels of fatigue (decay of −1.8 to −2.9% [WT] with reference to 0 kJ·kg−1 vs −1.1% to −4.4% [PT] after 15 kJ·kg−1 and of −4.7% to −8.8% [WT] vs −7.6% to −11.6% [PT] after 45 kJ·kg−1). No consistent differences were found between WT and PT cyclists in MMP values assessed in nonfatigue conditions (after 0 kJ·kg−1), but WT cyclists attained significantly higher MMP values with accumulating levels of fatigue, particularly for long-duration efforts (≥5 min). Conclusions: Our findings highlight the importance of considering fatigue when assessing the record power profile of endurance athletes and support the ability to attenuate fatigue-induced decline in MMP values as a determinant of endurance performance.
A synthetic monopole source of Kalb-Ramond field in diamond
Authors: Chen Mo , Li Changhao , Palumbo Giandomenico , Zhu Yan-Qing , Goldman Nathan , Cappellaro Paola
Published: March 2022

Magnetic monopoles play a central role in areas of physics that range from electromagnetism to topological matter. String theory promotes conventional vector gauge fields of electrodynamics to tensor gauge fields and predicts the existence of more exotic tensor monopoles. Here, we report the synthesis of a tensor monopole in a four-dimensional parameter space defined by the spin degrees of freedom of a single solid-state defect in diamond. Using two complementary methods, we characterized the tensor monopole by measuring its quantized topological charge and its emanating Kalb-Ramond field. By introducing a fictitious external field that breaks chiral symmetry, we further observed an intriguing spectral transition, characterized by spectral rings protected by mirror symmetries. Our work demonstrates the possibility of emulating exotic topological structures inspired by string theory.
A conserved superlocus regulates above- and belowground root initiation
Authors: Omary Moutasem , Gil-Yarom Naama , Yahav Chen , Steiner Evyatar , Hendelman Anat , Efroni Idan
Published: March 2022

Plants continuously form new organs in different developmental contexts in response to environmental cues. Underground lateral roots initiate from prepatterned cells in the main root, but cells can also bypass the root-shoot trajectory separation and generate shoot-borne roots through an unknown mechanism. We mapped tomato (
Solanum lycopersicum
) shoot-borne root development at single-cell resolution and showed that these roots initiate from phloem-associated cells through a unique transition state. This state requires the activity of a transcription factor that we named
SHOOTBORNE ROOTLESS
(
SBRL
)
.
Evolutionary analysis reveals that
SBRL
’s function and cis regulation are conserved in angiosperms and that it arose as an ancient duplication, with paralogs controlling wound-induced and lateral root initiation. We propose that the activation of a common transition state by context-specific regulators underlies the plasticity of plant root systems.
Transcriptional neighborhoods regulate transcript isoform lengths and expression levels
Authors: Brooks Aaron N. , Hughes Amanda L. , Clauder-Münster Sandra , Mitchell Leslie A. , Boeke Jef D. , Steinmetz Lars M.
Published: March 2022

Sequence features of genes and their flanking regulatory regions are determinants of RNA transcript isoform expression and have been used as context-independent plug-and-play modules in synthetic biology. However, genetic context—including the adjacent transcriptional environment—also influences transcript isoform expression levels and boundaries. We used synthetic yeast strains with stochastically repositioned genes to systematically disentangle the effects of sequence and context. Profiling 120 million full-length transcript molecules across 612 genomic perturbations, we observed sequence-independent alterations to gene expression levels and transcript isoform boundaries that were influenced by neighboring transcription. We identified features of transcriptional context that could predict these alterations and used these features to engineer a synthetic circuit where transcript length was controlled by neighboring transcription. This demonstrates how positional context can be leveraged in synthetic genome engineering.
Pebbles and sand on asteroid (162173) Ryugu: In situ observation and particles returned to Earth
Authors: Tachibana S. , Sawada H. , Okazaki R. , Takano Y. , Sakamoto K. , Miura Y. N. , Okamoto C. , Yano H. , Yamanouchi S. , Michel P. , Zhang Y. , Schwartz S. , Thuillet F. , Yurimoto H. , Nakamura T. , Noguchi T. , Yabuta H. , Naraoka H. , Tsuchiyama A. , Imae N. , Kurosawa K. , Nakamura A. M. , Ogawa K. , Sugita S. , Morota T. , Honda R. , Kameda S. , Tatsumi E. , Cho Y. , Yoshioka K. , Yokota Y. , Hayakawa M. , Matsuoka M. , Sakatani N. , Yamada M. , Kouyama T. , Suzuki H. , Honda C. , Yoshimitsu T. , Kubota T. , Demura H. , Yada T. , Nishimura M. , Yogata K. , Nakato A. , Yoshitake M. , Suzuki A. I. , Furuya S. , Hatakeda K. , Miyazaki A. , Kumagai K. , Okada T. , Abe M. , Usui T. , Ireland T. R. , Fujimoto M. , Yamada T. , Arakawa M. , Connolly H. C. , Fujii A. , Hasegawa S. , Hirata N. , Hirata N. , Hirose C. , Hosoda S. , Iijima Y. , Ikeda H. , Ishiguro M. , Ishihara Y. , Iwata T. , Kikuchi S. , Kitazato K. , Lauretta D. S. , Libourel G. , Marty B. , Matsumoto K. , Michikami T. , Mimasu Y. , Miura A. , Mori O. , Nakamura-Messenger K. , Namiki N. , Nguyen A. N. , Nittler L. R. , Noda H. , Noguchi R. , Ogawa N. , Ono G. , Ozaki M. , Senshu H. , Shimada T. , Shimaki Y. , Shirai K. , Soldini S. , Takahashi T. , Takei Y. , Takeuchi H. , Tsukizaki R. , Wada K. , Yamamoto Y. , Yoshikawa K. , Yumoto K. , Zolensky M. E. , Nakazawa S. , Terui F. , Tanaka S. , Saiki T. , Yoshikawa M. , Watanabe S. , Tsuda Y.
Published: March 2022

The Hayabusa2 spacecraft investigated the C-type (carbonaceous) asteroid (162173) Ryugu. The mission performed two landing operations to collect samples of surface and subsurface material, the latter exposed by an artificial impact. We present images of the second touchdown site, finding that ejecta from the impact crater was present at the sample location. Surface pebbles at both landing sites show morphological variations ranging from rugged to smooth, similar to Ryugu’s boulders, and shapes from quasi-spherical to flattened. The samples were returned to Earth on 6 December 2020. We describe the morphology of >5 grams of returned pebbles and sand. Their diverse color, shape, and structure are consistent with the observed materials of Ryugu; we conclude that they are a representative sample of the asteroid.
Rapid eye movement sleep is initiated by basolateral amygdala dopamine signaling in mice
Authors: Hasegawa Emi , Miyasaka Ai , Sakurai Katsuyasu , Cherasse Yoan , Li Yulong , Sakurai Takeshi
Published: March 2022

The sleep cycle is characterized by alternating non–rapid eye movement (NREM) and rapid eye movement (REM) sleeps. The mechanisms by which this cycle is generated are incompletely understood. We found that a transient increase of dopamine (DA) in the basolateral amygdala (BLA) during NREM sleep terminates NREM sleep and initiates REM sleep. DA acts on dopamine receptor D2 (Drd2)–expressing neurons in the BLA to induce the NREM-to-REM transition. This mechanism also plays a role in cataplectic attacks—a pathological intrusion of REM sleep into wakefulness—in narcoleptics. These results show a critical role of DA signaling in the BLA in initiating REM sleep and provide a neuronal basis for sleep cycle generation.
Highly enriched BEND3 prevents the premature activation of bivalent genes during differentiation
Authors: Zhang Jing , Zhang Yan , You Qinglong , Huang Chang , Zhang Tiantian , Wang Mingzhu , Zhang Tianwei , Yang Xiaocheng , Xiong Jun , Li Yingfeng , Liu Chao-Pei , Zhang Zhuqiang , Xu Rui-Ming , Zhu Bing
Published: March 2022

Bivalent genes are ready for activation upon the arrival of developmental cues. Here, we report that BEND3 is a CpG island (CGI)–binding protein that is enriched at regulatory elements. The cocrystal structure of BEND3 in complex with its target DNA reveals the structural basis for its DNA methylation–sensitive binding property. Mouse embryos ablated of
Bend3
died at the pregastrulation stage.
Bend3
null embryonic stem cells (ESCs) exhibited severe defects in differentiation, during which hundreds of CGI-containing bivalent genes were prematurely activated. BEND3 is required for the stable association of polycomb repressive complex 2 (PRC2) at bivalent genes that are highly occupied by BEND3, which suggests a reining function of BEND3 in maintaining high levels of H3K27me3 at these bivalent genes in ESCs to prevent their premature activation in the forthcoming developmental stage.
Elongation and branching of α-olefins by two ethylene molecules
Authors: Dietel Thomas , Lukas Fabian , Kretschmer Winfried P. , Kempe Rhett
Published: March 2022

α-Olefins are important starting materials for the production of plastics, pharmaceuticals, and fine and bulk chemicals. However, the selective synthesis of α-olefins from ethylene, a highly abundant and inexpensive feedstock, is restricted, and thus a broadly applicable selective α-olefin synthesis using ethylene is highly desirable. Here, we report the catalytic reaction of an α-olefin with two ethylene molecules. The first ethylene molecule forms a 4-ethyl branch and the second a new terminal carbon-carbon double bond (C2 elongation). The key to this reaction is the development of a highly active and stable molecular titanium catalyst that undergoes extremely fast β-hydride elimination and transfer.
China quietly plans a pivot from ‘zero COVID’
Authors: Normile Dennis
Published: March 2022

Scientists are studying how to live with the virus while avoiding a crisis like in Hong Kong
Genomic Sequence and Characteristics of EmiRose, a Bacteriophage Isolated on Corynebacterium flavescens
Authors: Davis Emily Rose , Perry-Richardson Blesyn , Mohamed Aleem , Ali Ilzat , Heller Danielle , Sivanathan Viknesh
Published: March 2022

Bacteriophage EmiRose is a siphovirus infecting
Corynebacterium flavescens
. The EmiRose genome is 37,431 bp long and composed of 47 protein-coding genes. Based on gene content similarity, EmiRose is not closely related to any previously sequenced bacteriophages in the actinobacteriophage database to date, including other corynebacteriophages. EmiRose is classified as a singleton.
Comparison of QuantiFERON-TB Gold In-Tube and QuantiFERON-TB Gold-Plus in the Diagnosis of
Mycobacterium tuberculosis
Infections in Immunocompromised Patients: a Real-World Study
Authors: Xu Yuzhen , Yang Qingluan , Zhou Jingyu , Zhou Feiran , Hezhang Yufan , Gao Yan , Shao Lingyun , Shi Jichan , Ruan Qiaoling , Zhang Wenhong
Published: March 2022

This study evaluated the performance of QFT-GIT and QFT-Plus in the diagnosis of
M. tuberculosis
infection in immunocompromised patients and found that QFT-Plus may detect more LTBI than QFT-GIT does in patients receiving long-term immunosuppressant therapy. We believe that our study makes a significant contribution to the literature because it highlights the different diagnostic accuracies of QFT-GIT and QFT-Plus in different subpopulations of immunocompromised and immunocompetent patients.
Fluid-assisted brecciation of Lower Cretaceous Maiolica limestone in the Umbria-Marche Apennines: Hydrodynamical implications
Authors: Chan* Lung Sang , Alvarez Walter , Geiser Peter , Tavarnelli Enrico
Published: March 2022

The formation of the “expansion breccia” observed in the Lower Cretaceous Maiolica limestone in the Umbria-Marches region of Italy is attributable to a fluid-assisted brecciation process that occurred during the late Miocene exhumation of the Northern Apennines. The hydrothermal fluids probably originated as brine solutions trapped in the Burano anhydrite while it was in a plastic state. The migration of the Burano from the plastic to the brittle domain during unroofing resulted in liberation and injection of over-pressured hydrothermal fluids into the overlying limestone, causing hydraulic fracturing. Mapping of breccia morphology along a 400-m transect showed structures produced by different flow regimes, with chaotic and mosaic breccia characterizing the core parts of the section and mineral-filled fractures and veins in the margins. Based on the clast size in the chaotic breccia, the estimated velocities for fluidizing the aggregates of clasts and sustaining the clasts in suspension are, respectively, 15 cm/s and 65 cm/s. Crack growth was probably the main mechanism for the fragmentation of the limestone. Explosion fracturing patterns were only sporadically observed in the breccia, indicating substantial heat loss of the over-pressured fluids during their ascent to the Earth’s surface.
Integrated stratigraphy of the Lutetian–Priabonian pelagic section at Bottaccione (Gubbio, central Italy): A proposal for defining and positioning the Global Stratotype Section and Point (GSSP) for the base of the Bartonian Stage (Paleogene System, Eocene Series)
Authors: Coccioni* Rodolfo , Montanari Alessandro , Boschi Samuele , Catanzariti Rita , Frontalini Fabrizio , Jovane Luigi , Kochhann Marcus Vinicius Lermen , Pelosi Nicola , Sabatino Nadia , Savian Jairo F. , Sprovieri Mario
Published: March 2022

At present, the Global Stratotype Section and Point (GSSP) for the base of the Bartonian remains the only GSSP of the Paleogene System to be defined by the International Subcommission on Paleogene Stratigraphy (ISPS) and the International Commission on Stratigraphy (ICS). Here, we present the results of an integrated, high-resolution study of calcareous plankton and benthic foraminifera biostratigraphy and a detailed magneto-, chemo-, and cyclostratigraphic analyses carried out through the upper Lutetian to the upper Priabonian pelagic sediments of the Bottaccione Gorge section near Gubbio, central Italy, to check its stratigraphic completeness and constrain in time the optimal interval for defining and positioning the GSSP for the base of the Bartonian Stage. The high-resolution and solid integrated stratigraphic framework established at Bottaccione confirmed the completeness of the section, which meets the ICS recommendations for a potential designation as a GSSP for the base of the Bartonian Stage. Thus, the Bottaccione section was compared with the parastratotype section of the Bartonian in its type area, Alum Bay, UK. On this basis, two reliable criteria for defining and positioning the Bartonian GSSP at Bottaccione are provided: (1) the base of magnetic polarity chronozone C18r as the primary correlation criterion and (2) the base of the calcareous nannofossil Dictyococcites bisectus, which defines the CNE14/CNE15 zonal boundary as a secondary correlation criterion.
Sedimentological and archaeological evidence for a Late Antique Little Ice Age climate event (536–660 CE) as recorded in a fluvial strath terrace of the Esino River (Marche region, Italy)
Authors: Montanari Alessandro , Mainiero Maurizio , Farabollini Piero , Pignocchi Gaia
Published: March 2022

Stratigraphic analysis of two sections of a fluvial strath terrace exposed on the left bank of the Esino River near the village of Trocchetti (province of Ancona, Marche region of central Italy), and the study of a large landslide located near the village of San Cristoforo, a few kilometers down valley from the Trocchetti fluvial terrace, provide evidence for two catastrophic environmental events, namely: (1) the aggradation on the riverbed of coarse, chaotic gravel due to a violent flashflood; and (2) the formation of a large ephemeral lake as the consequence of the landslide that barred the river channel at San Cristoforo. Archaeological and historical information about the lost Roman city of Tuficum, which was located just a kilometer upriver from the Trocchetti terrace, and ceramic artifacts found in the chaotic gravel unit, led us to the hypothesis that both the flashflood and the landslide were induced by the sudden, severe climate change of the Late Antique Little Ice Age (mid-sixth century to mid-seventh century CE).
Revisiting the archaeological site of Grotta dei Baffoni Cave (Frasassi Gorge, Italy): Integrated stratigraphy, archaeometry, and geochronology of upper Pleistocene–Holocene cave sediments
Authors: Montanari Alessandro , Ferretti Marco Peter , Mainiero Maurizio , McGee David , Pignocchi Gaia , Recanatini Stefano , Zorzin Roberto
Published: March 2022

In this paper, we present old and new data about our integrated interdisciplinary stratigraphic study of sedimentary deposits preserved in the Grotta dei Baffoni Cave of the Frasassi hypogenic cave complex, including sedimentological, paleontological, archaeometric, and radiometric analyses. This research work allowed us to reconstruct the geologic, environmental, and human history of this part of the northeastern Apennines of Italy for the past 200,000 years, from the late Middle Pleistocene to the Present. Accumulation of alluvial sediment began in this cave ~200,000 years ago, when an entrance was breached by the Sentino River during its process of incision and deepening of the Frasassi Gorge coupled with regional tectonic uplift. Flooding of the cave went on until the entrance sill of the cave was lifted up to an elevation that could no longer be reached by the river, sometime in the mid–Late Pleistocene. After this, windblown dust (i.e., loess) and coarser carbonate clasts derived from the disintegration of the vaults due to cryogenic processes and/or seismically induced collapses of the limestone vaults, accumulated on this now-dry underground environment. The stratigraphy of an ~4-m-thick sedimentary deposit accumulated in the vast atrium room of the cave was measured, sampled, and documented in two excavation trenches in 1952 by archaeologist Anton Mario Radmilli. By collecting a dozen stratigraphically located osteological finds for 14C dating, and revisiting artifacts collected by Radmilli, which are archived respectively in the Museum of Natural History of Verona and in the National Museum of Archaeology of Ancona, we assessed that the cave was frequented by wild animals, such as cave bear and ibex, starting in the mid–Late Pleistocene. Dating of charcoal particles from subsurface sediments in the inner part of the cave suggested that fires were lit in this cave by Epigravettian visitors during the Younger Dryas cold period. Scarce archaeological evidence nevertheless suggests that man began using this underground environment for worship practices probably in the early Neolithic. Human bones in the lower part of one of Radmilli's excavations yielded early Eneolithic ages. No other human bones were found in overlying levels of this excavation, but the typology of animal bones and associated ceramic artifacts, corroborated by our 14C dates, suggest that this cave was utilized as a worship or ritual place until the early Middle Bronze Age. After that, the cave was sporadically used as a shelter for herders until recent times.
Multimodal Magnetic Resonance and Fluorescence Imaging of the Induced Pluripotent Stem Cell Transplantation in the Brain
Authors: Zhang Y. C. , Wang J. W. , Wu Y. , Tao Q. , Wang F. F. , Wang N. , Ji X. R. , Li Y. G. , Yu S. , Zhang J. Z.
Published: March 2022

The understanding of the engrafted cell behaviors such as the survival, growth and distribution is the prerequisite to optimize cell therapy, and a multimodal imaging at both anatomical and molecular levels is designed to achieve this goal. We constructed a lentiviral vector carrying genes of ferritin heavy chain 1 (FTH1), near-infrared fluorescent protein (iRFP) and enhanced green fluorescent protein (egfp), and established the induced pluripotent stem cells (iPSCs) culture stably expressing these three reporter genes. These iPSCs showed green and near-infrared fluorescence as well as the iron uptake capacity in vitro. After transplanted the labeled iPSCs into the rat brain, the engrafted cells could be in vivo imaged using magnetic resonance imaging (MRI) and near-infrared fluorescent imaging (NIF) up to 60 days at the anatomical level. Moreover, these cells could be detected using EGFP immunostaining and Prussian blue stain at the cellular level. The developed approach provides a novel tool to study behaviors of the transplanted cells in a multimodal way, which will be valuable for the effectiveness and safety evaluation of cell therapy.
Injection laryngoplasty for laryngeal cleft type I in an 8-week-old infant
Authors: van Stigt Marit J B , van Oorschot Hanneke D , Bittermann Arnold J N
Published: March 2022

A laryngeal cleft is a rare anatomical deformity which is increasingly treated with injection laryngoplasty. Since diagnosis of laryngeal cleft type I is often made between 2 and 5 years of age, this treatment is rarely performed on very young children. In this case, we describe how injection laryngoplasty is performed safely on an 8-week-old child, and we illustrate its added value for the diagnostic process and for temporary symptom relief.
Elexacaftor, tezacaftor and ivacaftor: a case of severe rash and approach to desensitisation
Authors: Cheng Ann , Baker Olivia , Hill Uta
Published: March 2022

We present a case of severe rash following induction of elexacaftor, tezacaftor and ivacaftor (ELX/TEZ/IVA) in a young adult male cystic fibrosis patient. While rash is a commonly reported side effect which resolves in 1–2 weeks with minimal intervention, our patient had presented with fever and widespread rash prompting medication cessation. After a washout period, reintroduction with 1/2 tablet of ELX/TEZ/IVA produced a similar systemic response within 24 hours. Repeat attempt, this time with 1/8 tablet and increasing in increments of an eighth daily, was successful and has allowed our patient to experience the transformative benefits of ELX/TEZ/IVA including improved pulmonary function and reduced episodes of infective exacerbation. This case illustrates one of the most common side effects of ELX/TEZ/IVA triple therapy, and our experience of desensitisation to ELX/TEZ/IVA in a challenging case of rash.
ST-elevation myocardial infarction due to coronary thrombus in a young patient with diabetic ketoacidosis and a new diagnosis of type 2 diabetes
Authors: Doherty Daniel James , Sykes Robert , Connelly Paul , Hood Stuart
Published: March 2022

The association between cardiovascular disease and diabetes is increasingly understood and shared therapeutic targets are emerging. We describe the presentation and successful management of ST-elevation myocardial infarction (STEMI) secondary to coronary thrombus in a young patient with a new diagnosis of type 2 diabetes and diabetic ketoacidosis.
Susac syndrome with a unique involvement of the thoracic spinal cord
Authors: Mahmoud Rola A , Ungerer Robert , Gratton Sean , Schwartzman Michael J
Published: March 2022

A woman in her late 20s presented with headaches and subacute encephalopathy. MRIs showed multiple punctate subcortical and periventricular white matter hyperintensities with diffusion restriction, infratentorial lesions, leptomeningeal enhancement of the cervical spinal cord, brainstem and cerebellum and two areas of high-signal abnormality at T4 and T6 raising suspicion for multiple sclerosis or acute disseminated encephalomyelitis.

Further studies and evolution of her symptoms during her hospital stay confirmed the clinical triad of encephalopathy, branch retinal artery occlusions and hearing loss pathognomonic for Susac’s syndrome.

While cervical spinal cord and cauda equina involvement have been reported in Susac’s syndrome previously, no thoracic spinal cord involvement has been reported.

We report the novel MRI finding of thoracic spinal cord involvement in Susac’s syndrome. In order to avoid misdiagnosis, neurologists and neuroradiologists should be aware that any part of the spinal cord can be involved in Susac’s syndrome.
Streptococcus mitisinfective endocarditis in a patient with ventricular septal defect and orthodontic appliances
Authors: Amorgianos Dimitrios , Chen Hui Min , Walker Niki
Published: March 2022

We describe a case of a girl in a remote and rural location in Scotland with a perimembranous ventricular septal defect and orthodontic appliances, who developed right-sided infective endocarditis fromStreptococcus mitisdue to abrasion of the oral mucosa from the arch wire following its adjustment in the dental clinic.

Fitting and adjustment of orthodontic appliances are not considered to be high-risk dental procedures and antibiotic prophylaxis is not recommended even for patients at highest risk for infective endocarditis.
Private or shared room? A nationwide questionnaire survey on bereaved family members’ perceptions of where patients spend their last days
Authors: Otani Hiroyuki , Morita Tatsuya , Igarashi Naoko , Shima Yasuo , Miyashita Mitsunori
Published: March 2022

Background

Where patients receive end-of-life care influences their quality of life.

Objectives

To clarify the effects of staying in a private or shared room in inpatient hospices.

Design

A part of a Japanese multicentre survey to evaluate the quality of end-of-life care.

Setting/participants

779 bereaved families whose relatives who died from cancer in inpatient hospices.

Measurements

The primary outcome was family-perceived need for improvement in environment-related professional care. Secondary end-points included: family satisfaction, environment-related family perception, and quality of death and dying (Good Death Inventory: GDI).

Results

574 responded (73.7%). 300 patients were in a private room from admission to discharge, 47 were in a shared room less than 50% of the time, and the remaining 85 were in a shared room 50% or more. There were significant differences in the need for improvement in shared (vs private) rooms, and in favour of private rooms for: ‘privacy was protected’, ‘easy for visitors to visit’, ‘could discuss sensitive issues with medical staff without concern’, and ‘could visit at night.’, as well as ‘living in calm circumstances’ and ‘spending enough time with family’ of the GDI. Contrarily, significant differences were found in favour of shared rooms for: ‘the patient could interact with other patients’. There was no significant difference in family satisfaction and total score of GDI.

Conclusion

There are the advantages and disadvantages of spending one’s final days in a private or shared room, and adjusting rooms according to patients and their families’ values is necessary.
Association of frailty and cognitive function disorders in old patients with COVID-19: a protocol of systematic review and meta-analysis
Authors: Jiao Bo , Chen Mingyuan , Fan Minmin , Luo Xi , Chen Chan , Liu Jin
Published: March 2022

Introduction

COVID-19 infections have become an urgent worldwide public health concern. Although it is primarily a respiratory disease, up to two-thirds of hospitalised COVID-19 patients exhibit nervous system damage and an increased risk of frailty. In this study,we aim to investigate the relationship between frailty and cognitive function disorders in patients with COVID-19 with a systematic review and meta-analysis approach.

Methods and analysis

This meta-analysis has been registered by the International Prospective Register of Systematic Reviews. We will search for relevant studies from PubMed, Embase, Chinese Biological Medical Database, China National Knowledge Infrastructure, Wanfang Database, the Cochrane Central Register of Controlled Trials databases, from their inception to 5 July 2021. We will also search reference lists of selected articles for additional studies. Our search strategy will have no language restrictions. We will employ a ﬁxed or random-effects model to calculate OR and 95% CIs for pooled data, and assess heterogeneity using Cochrane’s Q and I2 tests. The primary outcome will be the rate of cognitive disorders related to frailty in old patients with COVID-19.

Ethics and dissemination

Ethical approval is not essential since data will be extracted from previously published studies. The results of this meta-analysis will be published in a peer-reviewed journal.

PROSPERO registration number

CRD42021257148.
Relationship between stereopsis and vision-related quality of life in patients with branch retinal vein occlusion
Authors: Morikawa Shohei , Okamoto Fumiki , Murakami Tomoya , Sugiura Yoshimi , Hiraoka Takahiro , Okamoto Yoshifumi , Oshika Tetsuro
Published: March 2022

Background

To investigate the relationship between stereopsis and vision-related quality of life (VR-QOL) in patients with branch retinal vein occlusion (BRVO) before and after treatment with intravitreal ranibizumab (IVR).

Methods

This prospective multicentred observational study included 37 patients undergoing IVR treatment for unilateral BRVO and 24 age-matched healthy controls.

Stereopsis was evaluated using the TNO stereo test (TNO) and Titmus stereo test (TST) every month, and the 25-item National Eye Institute Visual Function Questionnaire (VFQ-25) was administered at baseline, then at 3, 6 and 12 months after treatment.

Results

Time course of the changes in stereopsis and VR-QOL. IVR treatment significantly reduced central fovea thickness and improved both the TNO and the TST from 2 to 12 months (both p<0.05). Stereopsis before and after IVR injection in the eyes with BRVO were significantly worse than those in control subjects (TNO, p<0.001; TST, p<0.001). The VFQ-25 composite score significantly improved from 3 to 12 months after IVR treatment (p<0.05). Univariate analysis showed that the TNO score at baseline was significantly correlated with the VFQ-25 composite score at baseline and after treatment (p<0.05, p<0.05, respectively). TST score was not associated with the VFQ-25 composite score at baseline or after treatment.

Conclusions

Treatment with IVR for BRVO improved cystoid macular oedema, which was correlated to improved stereopsis, although not to the control level. The TNO score at baseline was associated with VR-QOL in patients with BRVO.
Responsiveness and meaningful change thresholds of the Living with Pulmonary Fibrosis (L-PF) questionnaire Dyspnoea and Cough scores in patients with progressive fibrosing interstitial lung diseases
Authors: Swigris Jeffrey J , Bushnell Donald M , Rohr Klaus , Mueller Heiko , Baldwin Michael , Inoue Yoshikazu
Published: March 2022

Background

The Living with Pulmonary Fibrosis (L-PF) questionnaire assesses symptoms and quality of life in patients with fibrosing interstitial lung diseases (ILDs). Its Dyspnoea and Cough domains, whose items’ responses are based on a 24-hour recall, have scores ranging from 0 to 100, with higher scores indicating greater symptom severity. We evaluated the ability of these domain scores to detect change and estimated their meaningful change thresholds in patients with progressive fibrosing ILDs.

Methods

The INBUILD trial enrolled subjects with progressive fibrosing ILDs other than idiopathic pulmonary fibrosis. The L-PF questionnaire was completed at baseline and week 52. The responsiveness of the Dyspnoea and Cough scores was evaluated by comparing changes in these scores with 52-week changes in three anchors: forced vital capacity % predicted and two self-reported items, one for global physical health and one for global quality of life. We used a triangulation approach including anchor-based and distribution-based methods to estimate meaningful change thresholds.

Results

The analyses included 542 subjects with an L-PF Dyspnoea score at baseline and week 52, and 538 subjects with an L-PF Cough score at baseline and week 52. The L-PF Dyspnoea and Cough scores were responsive to change over 52 weeks. Triangulation of anchor-based and distribution-based estimates resulted in meaningful change thresholds of 6 to 7 points for the L-PF Dyspnoea score and 4 to 5 points for the L-PF Cough score to differentiate subjects who were stable or improved from those who deteriorated.

Conclusion

These analyses support the responsiveness, one aspect of validity, of the L-PF Dyspnoea and Cough domains scores as measures of symptom severity in patients with progressive fibrosing ILDs. Estimates for meaningful change thresholds in these domain scores may be of value in interpreting the effects of interventions in these patients.

Trial registration number

NCT02999178.