451 research outputs found
Multidifferential study of identified charged hadron distributions in -tagged jets in proton-proton collisions at 13 TeV
Jet fragmentation functions are measured for the first time in proton-proton
collisions for charged pions, kaons, and protons within jets recoiling against
a boson. The charged-hadron distributions are studied longitudinally and
transversely to the jet direction for jets with transverse momentum 20 GeV and in the pseudorapidity range . The
data sample was collected with the LHCb experiment at a center-of-mass energy
of 13 TeV, corresponding to an integrated luminosity of 1.64 fb. Triple
differential distributions as a function of the hadron longitudinal momentum
fraction, hadron transverse momentum, and jet transverse momentum are also
measured for the first time. This helps constrain transverse-momentum-dependent
fragmentation functions. Differences in the shapes and magnitudes of the
measured distributions for the different hadron species provide insights into
the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any
supplementary material and additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb
public pages
Study of the decay
The decay is studied
in proton-proton collisions at a center-of-mass energy of TeV
using data corresponding to an integrated luminosity of 5
collected by the LHCb experiment. In the system, the
state observed at the BaBar and Belle experiments is
resolved into two narrower states, and ,
whose masses and widths are measured to be where the first uncertainties are statistical and the second
systematic. The results are consistent with a previous LHCb measurement using a
prompt sample. Evidence of a new
state is found with a local significance of , whose mass and width
are measured to be and , respectively. In addition, evidence of a new decay mode
is found with a significance of
. The relative branching fraction of with respect to the
decay is measured to be , where the first
uncertainty is statistical, the second systematic and the third originates from
the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb
public pages
Measurement of the ratios of branching fractions and
The ratios of branching fractions
and are measured, assuming isospin symmetry, using a
sample of proton-proton collision data corresponding to 3.0 fb of
integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The
tau lepton is identified in the decay mode
. The measured values are
and
, where the first uncertainty is
statistical and the second is systematic. The correlation between these
measurements is . Results are consistent with the current average
of these quantities and are at a combined 1.9 standard deviations from the
predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb
public pages
Large expert-curated database for benchmarking document similarity detection in biomedical literature search
Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
Vers’O: a support device to promote hydration for elderly people
International audienceIn 2003, a heat wave produced many casualties and allowed us to become aware this part of the population is sensible about dehydration. Some recommendations do exist, but only as advice, involving education of persons and caregivers. Unless the actual water intake is evaluated these recommendations are bound to be inefficient. This article introduces our concept of device to help to manage our real needs, but also instill a new way to hydrate ourselves
ECM protein nanofibers and nanostructures engineered using surface-initiated assembly.
<p>The extracellular matrix (ECM) in tissues is synthesized and assembled by cells to form a 3D fibrillar, protein network with tightly regulated fiber diameter, composition and organization. In addition to providing structural support, the physical and chemical properties of the ECM play an important role in multiple cellular processes including adhesion, differentiation, and apoptosis. In vivo, the ECM is assembled by exposing cryptic self-assembly (fibrillogenesis) sites within proteins. This process varies for different proteins, but fibronectin (FN) fibrillogenesis is well-characterized and serves as a model system for cell-mediated ECM assembly. Specifically, cells use integrin receptors on the cell membrane to bind FN dimers and actomyosin-generated contractile forces to unfold and expose binding sites for assembly into insoluble fibers. This receptor-mediated process enables cells to assemble and organize the ECM from the cellular to tissue scales. Here, we present a method termed surface-initiated assembly (SIA), which recapitulates cell-mediated matrix assembly using protein-surface interactions to unfold ECM proteins and assemble them into insoluble fibers. First, ECM proteins are adsorbed onto a hydrophobic polydimethylsiloxane (PDMS) surface where they partially denature (unfold) and expose cryptic binding domains. The unfolded proteins are then transferred in well-defined micro- and nanopatterns through microcontact printing onto a thermally responsive poly(N-isopropylacrylamide) (PIPAAm) surface. Thermally-triggered dissolution of the PIPAAm leads to final assembly and release of insoluble ECM protein nanofibers and nanostructures with well-defined geometries. Complex architectures are possible by engineering defined patterns on the PDMS stamps used for microcontact printing. In addition to FN, the SIA process can be used with laminin, fibrinogen and collagens type I and IV to create multi-component ECM nanostructures. Thus, SIA can be used to engineer ECM protein-based materials with precise control over the protein composition, fiber geometry and scaffold architecture in order to recapitulate the structure and composition of the ECM in vivo.</p
Nano- and Microstructured ECM and Biomimetic Scaffolds for Cardiac Tissue Engineering
<p>This chapter provides an overview of the heart and the biomimetic approaches used to engineer cardiac muscle tissue. It first describes the unique structure and function of cardiac muscle (myocardium), discusses how this dictates scaffold design, and then defines the benchmarks used to evaluate the performance of engineered cardiac tissue. Next, the chapter presents the different techniques researchers have developed to fabricate tissue-engineered cardiac scaffolds that mimic extracellular matrix (ECM) cues observed in the heart. For each case, the relevant physical, mechanical and/or chemical properties and the particular advantages and limitations of the approach, are discussed. Finally, the chapter discusses the persistent challenges to engineering functional cardiac tissue and the future directions of the field. Nano- and microfabrication techniques for cardiac tissue engineering enable the formation of scaffolds with anisotropic structure on the same scale as fibers in the native cardiac ECM.</p
Maintaining good relationships in clinical setting : the bonus DOMUS project
The DOMUS laboratory has recently participated in the construction of a brand new residence for persons with Traumatic Brain Injury (TBI). This building which comprises six apartments, and four bedrooms is equipped with the latest smart home technology (sensors, effectors, etc.). It is a living lab where prototype software, algorithms and technologies can be deployed for long term evaluation. One of the challenges that we have to face in a living lab setting is the maintaining of the good relationships with both the professionals and the residents. In that regard, the DOMUS team worked toward implementing simple technological services that would rapidly and directly enhance social participation and the quality of life of the residents. The goal is also to motivate them into taking part of the various research projects and to establish a trust relationship. In this paper, we present the Bonus DOMUS, a project that was created toward these aims. It enables the residents to have customized alarms and motivational messages
Nanofiber Biomaterials
<p>Since its inception, the field of tissue engineering has sought to rebuild the complexity of normal tissues by seeding cells onto scaffolds to support the formation of new tissue. Recently, nanofibers have gained increasing attention because these biomaterials have unique properties and are able to interface with cells at the same scale as native extracellular matrix fibrils. New fabrication technologies provide novel ways to control the nanoscale structure and properties of biomaterials, which is advantageous in the engineering of tissues for in vitro study and in vivo applications in regenerative medicine. This chapter explores the properties of nanofiber biomaterials (diameters <500 nm) and examines the specific advantages relative to other scaffold materials. This includes nanofibers from biopolymers as well as synthetic polymers, with consideration of relative advantages and disadvantages. A range of fabrication strategies is discussed that span from fiber spinning techniques, to phase separation in bulk, to directed and self-assembly. Insight is provided as to how synthetic polymers and biopolymers are used to make these nanofibers and the specific molecular structures that impart the unique mechanical, electrical, chemical, and biological properties. Analysis of these nanofiber biomaterialsrequires characterization techniques that are able to probe at the nanometer, micrometer, and macroscales. Examples are provided using optical microscopy, electron microscopy, scanning probe microscopy, mechanical characterization, and as sessment of biocompatibility and biodegradation.Finally, nanofiber biomaterials have wide applications in tissue engineering; here we focus on representative examples in cardiac, musculoskeletal, ophthalmic, and neural tissue engineering.</p
- …