bluuebunny/crossref_metadata_2025_split huggingface dataset:
An investigation into the microstructural and mechanical properties of the ZrB2/SiC composites prepared by silicon infiltration
Authors: Nilforoushan Mohammad Reza , Kazemzadeh Parya , Babaei Behzad , Tayebi Morteza , Yaghoubi Mohammad 
Published: April 2021

Abstract
In this study, the synthesis of ZrB2/SiC composite was carried out via infiltration of silicon melt into a ZrSiO4/B4C preform, and the effect of different ratios of ZrSiO4/B4C and C/ZrSiO4 was investigated on phase and microstructural properties. For this purpose, stoichiometric ratios of raw materials and 10 wt% phenolic resin were used to induce the porosities in the preform. Then the powder mixture was milled and pressed. To perform pyrolysis reaction, it was placed in a vacuum-controlled atmosphere furnace with argon gas at 650 °C and then the Si infiltration process was performed at 1650 °C for 1 h. The hardness, density, and elastic modulus of the samples were measured. The optimum results were obtained for the composite sample with a ZrSiO4/B4C ratio of 4, which had a density of 5.28 g cm−3, elastic modulus of 423 GPa, and hardness of 33.28 GPa. Moreover, scanning electron microscopy and x-ray diffraction analyses confirmed a uniform distribution of ZrB2 and SiC phases and the absence of undesirable phases in the sample, respectively.
The effects of thermal deformation temperatures on microstructure and mechanical properties of TiBw/Ti60 composites synthesized by SPS
Authors: Zhang Yueting , Wang Bo , Zhang Haobiao , Li Yang 
Published: April 2021

Abstract
In this work, 1vol.%, 3vol.% and 5vol.% TiBw/Ti60 composites were fabricated by spark plasma sintering (SPS) at 1150 °C with Ti60 powder and B powder. Scanning electron microscopy (SEM) confirmed that micro-nano enhancement TiBw can be obtained by SPS and the network structure were formed in the 3vol.% TiBw/Ti60 composites. The tensile properties of composites with different volume fraction at 600 °C show that 3vol.% TiBw/Ti60 composites have optimum comprehensive mechanical properties. The microstructure of thermal deformation of the 3vol.% TiBw/Ti60 composites shows that the matrix grains recrystallized at 1050 °C and the grains were refined. The tensile strength and elongation of the composites increased at first and then decreased with the increase of thermal deformation temperature. Highest values for flexural strength (∼752 MPa) and elongation (∼7.03%) were attained at 1050 °C, respectively. The strengthening mechanism can be mainly attributed to the directional arrangement of reinforcements and the grain refinement of the matrix.
Influence of anthopometric variables on the mechanical properties of human rib cortical bone
Authors: Velázquez-Ameijide Juan , García-Vilana Silvia , Sánchez-Molina David , Martínez-González Eva , Llumà Jordi , Rebollo-Soria M Carmen , Arregui-Dalmases Carlos 
Published: April 2021

Abstract

Objective. The mechanical properties of ribs from a large number of post-mortem human subjects (PMHS) were analyzed to search for variation according to age, sex or BMI in the sample. A large sample of specimens from different donors (N = 64) with a very wide range of ages and anthropometric characteristics was tested. Methods. Uniaxial tensile tests were used for a sample of coupons machined from cortical bone tissue in order to isolate the purely mechanical properties from the geometrically influenced properties of the rib. Each coupon is about 25 mm long and has a thickness of about 0.5 mm. The mechanical properties measured for each specimen/coupon include YM, yield stress, ultimate stress (maximum failure stress), ultimate strain, and resilience (energy to fracture of SED). The study provides new methodological improvements in DIC techniques. Results. This study is notable for using an atypically large sample of number of PMHS. The size of the sample allowed the authors to determine that age has a significant effect on failure stress (p < 0.0001), yield stress (p = 0.0047), ultimate strain (p < 0.0001) and resilience (p < 0.0001) [numbers in parentheses represent the corresponding p − values]. Finally, there is a combined effect, so that for a given age, an increase of BMI leads to a decrease of the maximum strain (i.e. cortical bone is less stiff when both age and BMI are higher).
Tailoring the triboelectric output of poly-L-lactic acid nanotubes through control of polymer crystallinity
Authors: Margaronis Kalliope , Busolo Tommaso , Nair Malavika , Chalklen Thomas , Kar-Narayan Sohini 
Published: April 2021

Abstract
Triboelectric devices capable of harvesting ambient mechanical energy have attracted attention in recent years for powering biomedical devices. Typically, triboelectric energy harvesters rely on contact-generated charges between pairs of materials situated at opposite ends of the triboelectric series. However, very few biocompatible polymeric materials exist at the ‘tribopositive’ end of the triboelectric series. In order to further explore the use of triboelectric energy harvesting devices within the body, it is necessary to develop more biocompatible tribopositive materials and look into ways to improve their triboelectric performance in order to enhance the harvested power output of these devices. Poly-L-lactic acid (PLLA) is a tribopositive biocompatible polymer, frequently used in biomedical applications. Here, we present a way to improve the triboelectric output of nanostructured PLLA through fine control of its crystallinity via a customised template-assisted nanotube (NT) fabrication process. We find that PLLA NTs with higher values of crystallinity (∼41%) give rise to a threefold enhancement of the maximum triboelectric power output as compared to NTs of the same material and geometry but with lower crystallinity (∼13%). Our results thus pave the way for the production of a viable polymeric and biocompatible tribopositive material with improved power generation, for possible use in implantable triboelectric nanogenerators.
Intense terahertz pulses inhibit Ras signaling and other cancer-associated signaling pathways in human skin tissue models
Authors: Hough Cameron M , Purschke David N , Huang Chenxi , Titova Lyubov V , Kovalchuk Olga V , Warkentin Brad J , Hegmann Frank A 
Published: April 2021

Abstract
Terahertz (THz) radiation has shown unique advantages in biomedical applications for novel diagnostic technologies due to the high sensitivity to molecular structure and chemical concentration. However, emerging evidence shows that intense pulses of THz radiation can induce significant non-thermal biological effects that must be characterized. In human skin exposed to intense THz pulses, relatively large responses characterized by differential gene expression profiles are observed. These data are analyzed by signaling pathway perturbation analysis to predict phenotypic endpoints and dysregulatory effects on cancer-related processes. The activities of several important pathways that drive the initiation, development, and progression of many human cancers are predicted to be suppressed, and this effect is intensity-dependent. Some affected pathways are targets for current and emerging anti-cancer therapies. In particular, the activity of the Ras signaling and Calcium signaling pathways is predicted to be significantly inhibited. These results indicate the possibility of an additional therapeutic mechanism of intense THz pulses, due to the potential for targeted suppression of pro-mitotic activity in diseased tissue.
Advances in scientific literature mining for interpreting materials characterization
Authors: Park Gilchan , Pouchard Line 
Published: April 2021

Abstract
Using synchrotron light sources, such as the National Synchrotron Light Source II at Brookhaven National Laboratory, scientists in fields as diverse as physics, biology, and materials science, identify the atomic structure, chemical composition, or other important properties of varied specimens. x-ray spectroscopy from light sources is particularly valuable for materials research with vast information available about reference spectra in the scientific literature. However, as the technique is applicable to many science domains, searching for information about select x-ray spectroscopy spectra is impeded by the sheer number of publications. Moreover, useful information about the context of an experiment or figures presented in papers can be buried among the details, which takes time to assess. This work presents a scientific literature mining system that supports data acquisition, information extraction, and user interaction for referencing x-ray spectra identification and spectral interpretation. The goal is to provide efficient access to useful spectral data to researchers who may spend only a few days at a synchrotron light source. With this system, users browse a classification tree for papers arranged according to x-ray spectroscopic methods, chemical elements, and x-ray absorption spectroscopy edges. Relevant figures are extracted with sentences from the paper that explain them, known as ‘figure explanatory text.’ Notably, this system focuses on semantic aspects (logical analysis) to find figure explanatory text using deep contextualized word embeddings techniques and contains an interface to obtain labeled data from domain experts that is used to evaluate and improve the model.
Conical tessellations associated with Weyl chambers
Authors: Godland Thomas , Kabluchko Zakhar 
Published: April 2021

We consider

d
d

-dimensional random vectors

Y
1

,
…
,

Y
n

Y_1,\ldots ,Y_n

that satisfy a mild general position assumption a.s. The hyperplanes

(

Y
i

−

Y
j

)
⊥

(
1
≤
i
>
j
≤
n
)

\begin{align*} (Y_i-Y_j)^\perp \;\; (1\le i>j\le n) \end{align*}

generate a conical tessellation of the Euclidean

d
d

-space which is closely related to the Weyl chambers of type

A

n
−
1

A_{n-1}

. We determine the number of cones in this tessellation and show that it is a.s. constant. For a random cone chosen uniformly at random from this random tessellation, we compute expectations of several geometric functionals. These include the face numbers, as well as the conic intrinsic volumes and the conical quermassintegrals. Under the additional assumption of exchangeability on

Y
1

,
…
,

Y
n

Y_1,\ldots ,Y_n

, the same is done for the dual random cones which have the same distribution as the positive hull of

Y
1

−

Y
2

,
…
,

Y

n
−
1

−

Y
n

Y_1-Y_2,\ldots , Y_{n-1}-Y_n

conditioned on the event that this positive hull is not equal to

R

d

\mathbb R^d

. All these expectations turn out to be distribution-free.

Similarly, we consider the conical tessellation induced by the hyperplanes

(

Y
i

+

Y
j

)
⊥

(
1
≤
i
>
j
≤
n
)
,

(

Y
i

−

Y
j

)
⊥

(
1
≤
i
>
j
≤
n
)
,

Y
i
⊥

(
1
≤
i
≤
n
)
.

\begin{align*} (Y_i+Y_j)^\perp \;\; (1 \le i>j\le n),\quad (Y_i-Y_j)^\perp \;\; (1\le i>j\le n),\quad Y_i^\perp \;\; (1\le i\le n). \end{align*}

This tessellation is closely related to the Weyl chambers of type

B
n

B_n

. We compute the number of cones in this tessellation and the expectations of various geometric functionals for random cones drawn from this random tessellation.

The main ingredient in the proofs is a connection between the number of faces of the tessellation and the number of faces of the Weyl chambers of the corresponding type that are intersected non-trivially by a certain linear subspace in general position.
A System for Phenotype Harmonization in the National Heart, Lung, and Blood Institute Trans-Omics for Precision Medicine (TOPMed) Program
Authors: Stilp Adrienne M , Emery Leslie S , Broome Jai G , Buth Erin J , Khan Alyna T , Laurie Cecelia A , Wang Fei Fei , Wong Quenna , Chen Dongquan , D’Augustine Catherine M , Heard-Costa Nancy L , Hohensee Chancellor R , Johnson William Craig , Juarez Lucia D , Liu Jingmin , Mutalik Karen M , Raffield Laura M , Wiggins Kerri L , de Vries Paul S , Kelly Tanika N , Kooperberg Charles , Natarajan Pradeep , Peloso Gina M , Peyser Patricia A , Reiner Alex P , Arnett Donna K , Aslibekyan Stella , Barnes Kathleen C , Bielak Lawrence F , Bis Joshua C , Cade Brian E , Chen Ming-Huei , Correa Adolfo , Cupples L Adrienne , de Andrade Mariza , Ellinor Patrick T , Fornage Myriam , Franceschini Nora , Gan Weiniu , Ganesh Santhi K , Graffelman Jan , Grove Megan L , Guo Xiuqing , Hawley Nicola L , Hsu Wan-Ling , Jackson Rebecca D , Jaquish Cashell E , Johnson Andrew D , Kardia Sharon L R , Kelly Shannon , Lee Jiwon , Mathias Rasika A , McGarvey Stephen T , Mitchell Braxton D , Montasser May E , Morrison Alanna C , North Kari E , Nouraie Seyed Mehdi , Oelsner Elizabeth C , Pankratz Nathan , Rich Stephen S , Rotter Jerome I , Smith Jennifer A , Taylor Kent D , Vasan Ramachandran S , Weeks Daniel E , Weiss Scott T , Wilson Carla G , Yanek Lisa R , Psaty Bruce M , Heckbert Susan R , Laurie Cathy C 
Published: April 2021

AbstractGenotype-phenotype association studies often combine phenotype data from multiple studies to increase statistical power. Harmonization of the data usually requires substantial effort due to heterogeneity in phenotype definitions, study design, data collection procedures, and data-set organization. Here we describe a centralized system for phenotype harmonization that includes input from phenotype domain and study experts, quality control, documentation, reproducible results, and data-sharing mechanisms. This system was developed for the National Heart, Lung, and Blood Institute’s Trans-Omics for Precision Medicine (TOPMed) program, which is generating genomic and other -omics data for more than 80 studies with extensive phenotype data. To date, 63 phenotypes have been harmonized across thousands of participants (recruited in 1948–2012) from up to 17 studies per phenotype. Here we discuss challenges in this undertaking and how they were addressed. The harmonized phenotype data and associated documentation have been submitted to National Institutes of Health data repositories for controlled access by the scientific community. We also provide materials to facilitate future harmonization efforts by the community, which include 1) the software code used to generate the 63 harmonized phenotypes, enabling others to reproduce, modify, or extend these harmonizations to additional studies, and 2) the results of labeling thousands of phenotype variables with controlled vocabulary terms.
Trajectories of Blood Pressure Control a Year After Randomization and Incident Cardiovascular Outcomes in SPRINT
Authors: German Charles A , Elfassy Tali , Singleton Matthew J , Rodriguez Carlos J , Ambrosius Walter T , Yeboah Joseph 
Published: April 2021

Abstract

BACKGROUND
While studies have assessed the association between blood pressure trajectories and cardiovascular disease (CVD) outcomes using observational data, few have assessed these associations using clinical trial data. We sought to identify systolic blood pressure (SBP) trajectories and to determine if these trajectory patterns carry inherent CVD risk, irrespective of baseline blood pressure.

METHODS
SBP trajectories were identified using latent class group-based modeling among a cohort of Systolic Blood Pressure Intervention Trial (SPRINT) participants by incorporating SBP measures during the first 12 months of the trial postrandomization. Cox models were used to evaluate the association between SBP trajectory with CVD and all-cause mortality.

RESULTS
Four distinct SBP trajectories were identified: “low decline” (41%), “high decline” (6%), “low stable” (48%), and “high stable” (5%). Relative to the “low decline” group, the “low stable” group was associated with a 29% increased risk of CVD (hazard ratio [HR]: 1.29, 95% confidence interval [CI]: 1.06–1.57) and the “high stable” group was associated with a 76% increased risk of all-cause mortality (HR: 1.76, 95% CI: 1.15–2.68). Relative to the “low stable” group, the “high stable” group was associated with a 54% increased risk of all-cause mortality (HR: 1.54, 95% CI: 1.05–2.28).

CONCLUSIONS
Our results demonstrate that SBP trajectory patterns are associated with important cardiovascular outcomes, irrespective of baseline blood pressure, which may help better identify individuals at risk and assist with accurate adjudication of antihypertensive therapy to reduce future events.
Terminal Schwann cells at the human neuromuscular junction
Authors: Alhindi Abrar , Boehm Ines , Forsythe Rachael O , Miller Janice , Skipworth Richard J E , Simpson Hamish , Jones Ross A , Gillingwater Thomas H 
Published: April 2021

Abstract
Terminal Schwann cells are non-myelinating glial cells localized to the neuromuscular junction. They play an important role in regulating many aspects of neuromuscular junction form and function, in health and during disease. However, almost all previous studies of mammalian terminal Schwann cells have used rodent models. Despite a growing awareness of differences in the cellular and molecular anatomy of rodent and human neuromuscular junctions, it remains unclear as to whether these differences also extend to the terminal Schwann cells. Here, we have adapted immunohistochemical protocols to facilitate visualization and comparative morphometric analyses of terminal Schwann cells at the human and mouse neuromuscular junction. We labelled terminal Schwann cells in the peroneus brevis muscle in six adult mice and five humans with antibodies against S100 protein. All human neuromuscular junctions were associated with at least one terminal Schwann cell, consistent with findings from other species, with an average of ∼1.7 terminal Schwann cells per neuromuscular junction in both humans and mice. In contrast, human terminal Schwann cells were significantly smaller than those of mice (P ≤ 0.01), in keeping with differences in overall synaptic size. Human terminal Schwann cell cytoplasm extended significantly beyond the synaptic boundaries of the neuromuscular junction, whereas terminal Schwann cells in mice were largely restricted to the synapse. Moreover, there was a significant difference in the location of terminal Schwann cell nuclei (P ≤ 0.01), with human terminal Schwann cells having their nuclear compartment located beyond the perimeter of the synapse more than the mouse. Taken together, these findings demonstrate that terminal Schwann cells at the human neuromuscular junction have notable differences in their morphology and synaptic relationships compared to mice. These fundamental differences need to be considered when translating the findings of both neuromuscular junction biology and pathology from rodents to humans.
Mesenchymal stem cell-based therapy for burn wound healing
Authors: Wang Mingyao , Xu Xinxuan , Lei Xiongxin , Tan Jie , Xie Huiqi 
Published: April 2021

Abstract
Burns, with their high incidence and mortality rates, have a devastating effect on patients. There are still huge challenges in the management of burns. Mesenchymal stem cells (MSCs), which have multidirectional differentiation potential, have aroused interest in exploring the capacity for treating different intractable diseases due to their strong proliferation, tissue repair, immune tolerance and paracrine abilities, among other features. Currently, several animal studies have shown that MSCs play various roles and have beneficial effects in promoting wound healing, inhibiting burn inflammation and preventing the formation of pathological scars during burn healing process. The substances MSCs secrete can act on peripheral cells and promote burn repair. According to preclinical research, MSC-based treatments can effectively improve burn wound healing and reduce pain. However, due to the small number of patients and the lack of controls, treatment plans and evaluation criteria vary widely, thus limiting the value of these clinical studies. Therefore, to better evaluate the safety and effectiveness of MSC-based burn treatments, standardization of the application scheme and evaluation criteria of MSC therapy in burn treatment is required in the future. In addition, the combination of MSC pretreatment and dressing materials are also conducive to improving the therapeutic effect of MSCs on burns. In this article, we review current animal research and clinical trials based on the use of stem cell therapy for treating burns and discuss the main challenges and coping strategies facing future clinical applications.
Extensive Cortical Connectivity of the Human Hippocampal Memory System: Beyond the “What” and “Where” Dual Stream Model
Authors: Huang Chu-Chung , Rolls Edmund T , Hsu Chih-Chin Heather , Feng Jianfeng , Lin Ching-Po 
Published: April 2021

AbstractThe human hippocampus is involved in forming new memories: damage impairs memory. The dual stream model suggests that object “what” representations from ventral stream temporal cortex project to the hippocampus via the perirhinal and then lateral entorhinal cortex, and spatial “where” representations from the dorsal parietal stream via the parahippocampal gyrus and then medial entorhinal cortex. The hippocampus can then associate these inputs to form episodic memories of what happened where. Diffusion tractography was used to reveal the direct connections of hippocampal system areas in humans. This provides evidence that the human hippocampus has extensive direct cortical connections, with connections that bypass the entorhinal cortex to connect with the perirhinal and parahippocampal cortex, with the temporal pole, with the posterior and retrosplenial cingulate cortex, and even with early sensory cortical areas. The connections are less hierarchical and segregated than in the dual stream model. This provides a foundation for a conceptualization for how the hippocampal memory system connects with the cerebral cortex and operates in humans. One implication is that prehippocampal cortical areas such as the parahippocampal TF and TH subregions and perirhinal cortices may implement specialized computations that can benefit from inputs from the dorsal and ventral streams.
Five-year outcome in 18 010 patients from the German Aortic Valve Registry
Authors: Beyersdorf Friedhelm , Bauer Timm , Freemantle Nick , Walther Thomas , Frerker Christian , Herrmann Eva , Bleiziffer Sabine , Möllmann Helge , Landwehr Sandra , Ensminger Stephan , Bekeredjian Raffi , Cremer Jochen , Kuck Karl Heinz , Fujita Buntaro , Gummert Jan , Müller Lisa , Beckmann Andreas , Hamm Christian W ,   for the GARY Executive Board
Published: April 2021

Abstract

OBJECTIVES
To determine the 5-year outcome in patients treated by isolated transcatheter aortic valve implantation (TAVI) or surgical aortic valve replacement (sAVR)—a prospective observational cohort study.

METHODS
A total of 18 010 patients were included (n = 8942 TAVI and n = 9068 sAVR) in the German Aortic Valve Registry (GARY) who were treated in 2011 and 2012 at 92 sites in central Germany. Eligible patients with TAVI and sAVR were matched using propensity scores in a nearest-neighbour approach. Patients with repeat procedures or unequivocal indication for one treatment option (e.g. frailty) were excluded (n = 4785 for TAVI and n = 2 for sAVR). This led to 13 223 patients (4157 TAVI and 9066 sAVR) as an unmatched subcohort. The main outcome measure was the 5-year all-cause mortality.

RESULTS
TAVI patients were significantly older (80.9 ± 6.1 vs 68.5 ± 11.1 years, P &lt; 0.001), had a higher Society of Thoracic Surgeons (STS) score (6.3 ± 4.9 vs 2.6 ± 3.0, P &lt; 0.001) and a higher 5-year all-cause mortality (49.8% vs 16.5%, P &lt; 0.0001). There was no major difference in in-hospital stroke, in-hospital myocardial infarction, or temporary and chronic dialysis. In the propensity score-matched group (n = 3640), there were 763 deaths (41.9%) among 1820 TAVI patients compared with 552 (30.3%) among 1820 treated with sAVR during the 5-year follow-up (hazard ratio 1.51, 95% confidence interval 1.35–1.68; P &lt; 0.0001). New pacemaker implantation was performed in 448 patients (24.6%) after TAVI and in 201 (11.0%) after sAVR (P &lt; 0.0001).

CONCLUSIONS
The 5-year follow-up data show that TAVI patients were significantly older and had a higher STS score than sAVR patients. After propensity score matching, TAVI with early-generation prosthesis was associated with significantly higher 5-year all-cause mortality than sAVR.