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Multi-parametric photoacoustic microscopy (PAM) has emerged as a promising new technique for high-resolution quantification of hemodynamics and oxygen metabolism in the mouse brain. In this work, we have extended the scope of multi-parametric PAM to longitudinal, cortex-wide, awake-brain imaging with the use of a long-lifetime (24 weeks), wide-field (5 × 7 mm2), light-weight (2 g), dual-transparency ( i.e., light and ultrasound) cranial window. Cerebrovascular responses to the window installation were examined in vivo, showing a complete recovery in 18 days. In the 22-week monitoring after the recovery, no dura thickening, skull regrowth, or changes in cerebrovascular structure and function were observed. The promise of this technique was demonstrated by monitoring vascular and metabolic responses of the awake mouse brain to ischemic stroke throughout the acute, subacute, and chronic stages. Side-by-side comparison of the responses in the ipsilateral (injury) and contralateral (control) cortices shows that despite an early recovery of cerebral blood flow and an increase in microvessel density, a long-lasting deficit in cerebral oxygen metabolism was observed throughout the chronic stage in the injured cortex, part of which proceeded to infarction. This longitudinal, functional-metabolic imaging technique opens new opportunities to study the chronic progression and therapeutic responses of neurovascular diseases.

Introduction The term “carotidynia” has been used to describe a symptom or a nosologic entity characterized by pain in the lateral neck region and over the carotid bifurcation. Recent advances in diagnostic imaging and the introduction of diagnostic criteria have led to the adoption of term “Transient perivascular inflammation of the carotid artery” (TIPIC) syndrome. Method A retrospective analysis of the Radiology Department’s database was performed to identify cases with the diagnosis of TIPIC syndrome. The purpose was to identify ultrasound images including B-mode technique, colour, power Doppler technique and contrast-enhanced ultrasound (CEUS). Findings In total, five patients with the diagnosis of TIPIC syndrome are presented in this review. TIPIC syndrome is a clinic-radiologic entity characterized by pain over the carotid area, a symptom referring to a wide differential diagnosis where imaging plays a crucial role for proper diagnosis and treatment. Characteristic imaging findings on conventional ultrasound and CEUS are presented in this review. Discussion TIPIC syndrome can be investigated with virtually any imaging modality. Ultrasound typically reveals perivascular infiltration and a hypoechoic intimal plaque, while no significant luminal narrowing is appreciated. Computed tomography angiography and magnetic resonance angiography also demonstrate these vascular wall changes primarily affecting the distal common carotid artery, the carotid bulb and possibly the internal carotid artery proximal part. Contrast enhancement is a very characteristic and constant finding of TIPIC lesions, suggestive of the inflammatory nature of the disease and can be appreciated on computed tomography angiography and magnetic resonance angiography. CEUS has been recently used and successfully observed contrast enhancement of the lesions, similar to computed tomography angiography and magnetic resonance angiography. Conclusion Ultrasound remains the first-line modality for the evaluation of TIPIC syndrome, capable of providing all the information needed, especially if supplemented with the administration of microbubbles so that the enhancement of lesions can be evaluated.

Electric power steering systems have been used to generate assist torque for driver comfort. This study makes use of the functionality of electric power steering systems for autonomous steering control without driver torque. A column-type electric power steering test bench, equipped with a brushless DC motor as an assist motor, and the Infineon TriCore AURIX TC 277 microcontroller was used in this study. Multi-parametric model predictive control is based on a model predictive control–based approach that employs a multi-parametric quadratic programming technique. This technique allows the reduction of the huge computational burden resulting from the online optimization in model predictive control. The proposed controller obtains an optimal input based on multi-parametric quadratic programming at each sampling time. The weighting matrix definition, which is the main task when designing the proposed controller, was analyzed. The experimental results of the step response of the steering wheel angle verified the tracking ability of the proposed controller for different ranges of the prediction horizon. Since the computational loads are directly related to functional safety, the results of this study support the use of the multi-parametric model predictive control scheme as an effective control method for autonomous steering control.

A novel post-processing methodology able to assess whole-body tumor heterogeneity in patients with metastatic disease is proposed. The method is demonstrated on paired pre- and post-treatment data sets obtained from an initial cohort of six patients with metastatic disease from primary prostate or ovarian cancers. Whole-body diffusion-weighted imaging and T1-weighted contrast-enhanced imaging data were acquired covering the chest, abdomen, and pelvis. Joint histograms of Apparent Diffusion Coefficient and Fractional Enhancement values were calculated within volumes of interest and were modeled as a Gaussian mixture of two classes. Probability maps and volumetric estimates of the magnetic resonance data-derived classes providing visualization of pre- and post-treatment data are shown in three patient examples. This technique provided spatially heterogeneous characterization of regions following treatment as defined by the combined analysis of apparent diffusion coefficient and fractional enhancement. A new whole-body magnetic resonance data analysis has been demonstrated enabling visualization of intra-patient response heterogeneity in patients with metastatic cancer. Changes in the parameters of each subpopulation derived from this technique (apparent diffusion coefficient and fractional enhancement) reflect changes in the tissue properties of each subpopulation following treatment. Furthermore, the volume change of each population can be quantified. Such techniques may be essential for personalized anti-cancer therapy where there is a need to detect early drug-resistance and monitor heterogeneous response.

Relative oxygen extraction fraction (rOEF) is a fundamental indicator of cerebral metabolic function. An easily applicable method for magnetic resonance imaging (MRI) based rOEF mapping is the multi-parametric quantitative blood oxygenation level dependent (mq-BOLD) approach with separate acquisitions of transverse relaxation times [Formula: see text] and T2 and dynamic susceptibility contrast (DSC) based relative cerebral blood volume (rCBV). Given that transverse relaxation and rCBV in white matter (WM) strongly depend on nerve fiber orientation, mq-BOLD derived rOEF is expected to be affected as well. To investigate fiber orientation related rOEF artefacts, we present a methodological study characterizing anisotropy effects of WM as measured by diffusion tensor imaging (DTI) on mq-BOLD in 30 healthy volunteers. Using a 3T clinical MRI-scanner, we performed a comprehensive correlation of all parameters ([Formula: see text], T2, [Formula: see text], rCBV, rOEF, where [Formula: see text]=1/[Formula: see text]–1/T2) with DTI-derived fiber orientation towards the main magnetic field (B0). Our results confirm strong dependencies of transverse relaxation and rCBV on the nerve fiber orientation towards B0, with anisotropy-driven variations up to 37%. Comparably weak orientation-dependent variations of mq-BOLD derived rOEF (3.8%) demonstrate partially counteracting influences of [Formula: see text] and rCBV effects, possibly suggesting applicability of rOEF as an oxygenation sensitive biomarker. However, unresolved issues warrant caution when applying mq-BOLD to WM.

Multi-walled carbon nanotubes with excellent electrical properties and high aspect ratios can reduce the high field strength required to kill cancer cells in vitro with nanosecond pulsed electric fields. For the first time, this article systematically and comprehensively evaluates the effects of various parameters of nanosecond pulsed electric fields combined with multi-walled carbon nanotubes on cell viability. The effects of field strength, E (2-10 kV/cm); pulse width, τ (100-500 ns); and pulse number, N (5-260) on the viability of A375 human skin cancer cells in the presence of multi-walled carbon nanotubes are studied using the Cell Counting Kit 8 assay. Based on a logistic model, the relationship between cell viability and various parameters is obtained using 1-dimensional nonlinear fitting. The results show a sigmoid-type variation in cell viability with field strength, pulse width, or pulse number. Multivariate scaling analysis shows that the relationship between cell viability and the pulse energy density σE2 τN can be described as a sigmoid type. The introduction of multi-walled carbon nanotubes does not affect the above rules but significantly enhances the killing effect of nanosecond pulsed electric fields, which could effectively improve the electrical safety of nanosecond pulsed electric fields for the treatment of tumors.

In this paper, passive and active control methods are applied to reduce the torsional vibration of a nonlinear dynamical system. This system is subjected to multi parametric excitation forces and modeled by the coupled nonlinear differential equations. This leads to two degrees of freedom and three degrees of freedom when the torsional absorber is connected to the system. A multiple scale perturbation technique is applied to obtain an approximate solution and investigate the response of the system. The stability and the steady-state response of the system near the simultaneous sub-harmonic and internal resonances are studied and discussed using the frequency response function method. The numerical solution and chaotic response of the nonlinear dynamical system for different parameters are also studied. The simulation results are achieved using MATLAB 7.0 programs.

Due to rapid urbanization of developing cities, the planners have a major challenge in designing climate responsive built environment for modern urban dwellers. In order to maintain a good built environmental quality, the various key design parameters of existing built form would need to be reviewed and analyzed to seek appropriate improvement. The present paper highlights the case study of a test room model in an educational campus. The experimentation was carried out in composite climatic zone of Nagpur in India. The desired built environment parameters viz., indoor light intensity, temperature and humidity was recorded and analyzed during experiments under controlled conditions of room openings. A functional index model was developed by this study using the multi-parametric regression analysis of the results. The qualitative assessment of the aforesaid parameters in terms of indoor comfort in the built environment was carried out. The developed mathematical index model for various functional parameters over the given geographic location can suitably be used by the designers for evaluating and enhancing the indoor comfort of a built environment suitable for the climate of Nagpur, India.