5 research outputs found
Numerical Approach to Facial Palsy Using a Novel Registration Method with 3D Facial Landmark
Treatment of facial palsy is essential because neglecting this disorder can lead to serious sequelae and further damage. For an objective evaluation and consistent rehabilitation training program of facial palsy patients, a clinician’s evaluation must be simultaneously performed alongside quantitative evaluation. Recent research has evaluated facial palsy using 68 facial landmarks as features. However, facial palsy has numerous features, whereas existing studies use relatively few landmarks; moreover, they do not confirm the degree of improvement in the patient. In addition, as the face of a normal person is not perfectly symmetrical, it must be compared with previous images taken at a different time. Therefore, we introduce three methods to numerically approach measuring the degree of facial palsy after extracting 478 3D facial landmarks from 2D RGB images taken at different times. The proposed numerical approach performs registration to compare the same facial palsy patients at different times. We scale landmarks by performing scale matching before global registration. After scale matching, coarse registration is performed with global registration. Point-to-plane ICP is performed using the transformation matrix obtained from global registration as the initial matrix. After registration, the distance symmetry, angular symmetry, and amount of landmark movement are calculated for the left and right sides of the face. The degree of facial palsy at a certain point in time can be approached numerically and can be compared with the degree of palsy at other times. For the same facial expressions, the degree of facial palsy at different times can be measured through distance and angle symmetry. For different facial expressions, the simultaneous degree of facial palsy in the left and right sides can be compared through the amount of landmark movement. Through experiments, the proposed method was tested using the facial palsy patient database at different times. The experiments involved clinicians and confirmed that using the proposed numerical approach can help assess the progression of facial palsy
Immature dendritic cells navigate microscopic mazes to find tumor cells
Dendritic cells (DCs) are potent antigen-presenting cells with high sentinel ability to scan their neighborhood and to initiate an adaptive immune response. Whereas chemotactic migration of mature DCs (mDCs) towards lymph nodes is relatively well documented, the migratory behavior of immature DCs (imDCs) in tumor microenvironments is still poorly understood. Here, microfluidic systems of various geometries, including mazes, are used to investigate how the physical and chemical microenvironment influences the migration pattern of imDCs. Under proper degree of confinement, the imDCs are preferentially recruited towards cancer vs. normal cells, accompanied by increased cell speed and persistence. Furthermore, a systematic screen of cytokines, reveals that Gas6 is a major chemokine responsible for the chemotactic preference. These results and the accompanying theoretical model suggest that imDC migration in complex tissue environments is tuned by a proper balance between the strength of the chemical gradients and the degree of spatial confinement
Chemically Driven, Water-Soluble Composites of Carbon Nanotubes and Silver Nanoparticles as Stretchable Conductors
In the past decade, hybrid materials
for highly stretchable, conductive
electrodes have received tremendous attention in the fields of emerging
wearable electronic, optoelectronic, and sensing devices. Here, we
present a previously unrecognized aqueous route to producing stretchable
conductors composed of silver nanoparticles (AgNPs) and single-walled
carbon nanotubes (SWNTs) embedded in a polyurethane (PU) matrix, in
contrast to ones dispersed in toxic organic solvents reported to date.
The intact chemical interaction between one-dimensional SWNTs, for
endowing the capability of establishing conductive pathways even in
stretching conditions, and AgNPs, for enabling high conductivity of
the composites, is achieved in an aqueous medium with an anionic polyelectrolyte,
poly(acrylic acid), that undergoes pH-dependent conformational evolution.
With this aqueous approach, we demonstrate that AgNP–SWNT–PU
composites supported on PDMS substrates have the conductivities of
620 and 120 S cm<sup>–1</sup> in unstrained and 90% elongated
conditions, respectively, and display repeatable reversibility at
a strain of 60%