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The effects of layer thickness and stiffness on multilayer bending actuator performance were investigated with an analytical mechanical model. Performance was evaluated in terms of curvature, blocked force, and work. Multilayer device designs corresponding to dielectric elastomer actuator, ionic polymer metal composite, and conjugated polymer structures were examined. Normalized plots of the performance metrics as functions of relative layer thickness and stiffness are presented that should allow initial, starting-point estimates for designs for particular applications. The results show that to achieve high curvature, layer thickness and stiffness may need to be set above or below particular bounds, or varied together, depending on the device configuration; often there is a broad plateau of combinations that work equally well. There is a conflict between achieving high bending and high force: the former requires the device to behave as much as possible like a simple bilayer with optimal ratios of thickness and modulus, while the latter requires thicker layers and shows little dependence on their moduli. Finally, to maximize work there are areas in the thickness-modulus plane that should be avoided, these areas varying with the configuration in sometimes surprising ways. [ABSTRACT FROM AUTHOR]

Whether a refugium, a transit area, or both, the Balkan Peninsula played a crucial role in the population dynamics of Europe during prehistory. However, the Balkans Peninsula is poorly represented in the European archaeological record. This article presents the newly discovered Middle Palaeolithic stone tool assemblage from the Uzun Mera site in the eastern Republic of Macedonia. Following fieldwork that included diverse methods in survey and excavation, as well as techno-economical and taphonomic assessment of the recovered stone tools, Uzun Mera is reported here as a typical Middle Palaeolithic assemblage that follows the pattern of a highly variable Balkan complex. The quality of the raw material reflects a highly selective approach, resulting in relatively low lithological variability where small blocks of raw material used for knapping are still present on site. These results contribute to better understanding the Palaeolithic of the Balkans and inform the population process in a region where little investigation has been previously conducted. [ABSTRACT FROM AUTHOR]

Brachytherapy delivers a targeted dose directly to the tumor while minimizing exposure to surrounding healthy tissue [1]. The precise placement of radioactive seeds ensures that radiation reaches the intended targets enhancing treatment efficacy [2]. A combination of low-field MRI and brachytherapy can improve the targeting accuracy of the treatment by providing more detailed anatomic data during seed placement. We present an innovative MRI-safe needle guidance system that is integrated with a single-sided, low-field Promaxo MRI system (Promaxo Inc., Oakland, California, United States) that can be used in needle and cannula placement during brachytherapy procedures. The needle guidance system we built has five degrees of freedom (DOF), is made of MRI-safe materials, is compact, and is actuated by pneumatic stepper motors. The needle guidance employs a spherical parallel mechanism to insert the needle from varied angles. After angulation, a translation screw is used to insert needles or cannulas at varying depths. A multi-modality prostate phantom model (Yezitronix Group Inc. Automation & Control Industries Inc.) that mimics the human prostate and its surrounding structures was used to evaluate the system's effectiveness in needle positioning. In a laboratory experiment, needle placement precision was confirmed by piercing the phantom along a vertical line spaced equally deep, and then comparing the achieved distances with the distance between air tracks in Computed Tomography (CT) scan images of the phantom (Figure 1). The experimental results reveal an absolute error (mean ± SD) of 0.75±0.73 mm on the vertical line and 0.24±0.14 mm in depth. These results demonstrate the potential for enhanced precision during brachytherapy procedures with the use of MRI-guided robotic manipulation, which in turn may improve patient outcomes. [ABSTRACT FROM AUTHOR]

In this paper the results of the geophysical investigation on the archeological site Isar-Marvinci are presented. The results show low changes in the magnetic field and the local gradient, as it is an archeological site where there are no buildings and structures built of baked bricks that cause larger magnetic changes in the magnetic field over 100 [nT] or more [nT]. Small anomalies of the magnetic gradient probably indicate graves that have been confirmed by illegal diggers, whose presence can be seen on the ground. [ABSTRACT FROM AUTHOR]

• We observed excellent long-term disease control with SBRT and potential for prolonged survival particularly among patients with oligometastatic disease at the time of SBRT. • The 24-month cumulative incidence of local failure was 7.4% after SBRT for pulmonary sarcoma metastases. • We observed low rates of toxicity, including no grade 3 or greater toxicity. This cohort included patients with ultra-central lesions and multiple pulmonary metastases treated with SBRT simultaneously. • SBRT is an important treatment modality for patients with sarcoma pulmonary metastases, particularly patients who are unfit for surgery or have unresectable metastases. Stereotactic body radiation therapy (SBRT) is standard for patients with inoperable early-stage NSCLC. We hypothesized that SBRT for sarcoma pulmonary metastases would achieve high rates of local control with acceptable toxicity and that patients with oligometastatic disease may achieve prolonged survival following SBRT. This retrospective review included consecutive patients at our institution treated with SBRT for sarcoma pulmonary metastases. Cumulative incidence of local failure (LF) was estimated using a competing risks framework. We identified 66 patients treated to 95 pulmonary metastases with SBRT. The median follow-up from the time of SBRT was 36 months (95% CI 34 – 53 months). The cumulative incidence of LF at 12 and 24 months was 3.1% (95% CI 0.9 – 10.6%) and 7.4% (95% CI 4.0% - 13.9%), respectively. The 12- and 24-month overall survival was 74% (95% CI 64 – 86%) and 49% (38 – 63%), respectively. Oligometastatic disease, intrathoracic only disease, and performance status were associated with improved survival on univariable analysis. Three patients had grade 2 pneumonitis, and one patient had grade 2 esophagitis. No patients had ≥ grade 3+ toxicities. To the best of our knowledge, this is the largest series of patients treated with SBRT for pulmonary sarcoma metastases. We observed that SBRT offers an effective alternative to surgical resection with excellent local control and low proportions of toxicity. [ABSTRACT FROM AUTHOR]

Stereotactic body radiotherapy (SBRT) is standard for patients with inoperable early-stage NSCLC and is frequently utilized for pulmonary metastases with limited data. We hypothesized that SBRT for sarcoma pulmonary metastases would achieve high rates of local control with acceptable toxicity and that patients with oligometastatic disease may achieve prolonged survival following SBRT. This IRB-approved retrospective review included patients at our institution treated with SBRT for sarcoma pulmonary metastases. SBRT was delivered in 1 - 8 fractions at the discretion of the treating clinician. Patients were classified as oligometastatic if they had ≤ 3 sites of disease or progression at ≤ 3 sites of metastatic disease. Cumulative incidence of local failure (LF) was calculated using competing risks analysis and compared across groups using Grey's test. LF was defined as progression in the SBRT field on 2 consecutive follow-up scans with LF date backdated to the earliest scan showing progression. We also evaluated toxicity and overall survival from the time of SBRT. Overall survival (OS) was estimated using the Kaplan-Meier method and compared across groups using the Log rank test and Cox proportional hazards regression. Between 2011 and 2021, 69 patients with 101 sarcoma pulmonary metastases were treated with SBRT to a median dose of 48 Gy (range: 25 – 60 Gy) in 4 fractions (range: 1 – 8 fractions). The most common histologies were leiomyosarcoma (n = 20 patients), liposarcoma (n = 8 patients), and osteosarcoma (n = 7 patients). The median follow-up time from SBRT was 26.1 months (95% CI 20.9-34.4) and 19.8 months for patients alive at last follow-up. A total of 35 patients (51%) were oligometastatic. The cumulative incidence of LF at 12 and 24 months was 6% (95% CI 3% to 12%) and 11% (95% CI 6% to 19%), respectively. The cumulative incidence of LF was significantly lower for peripheral compared to central lesions (12-month LF 11.4% vs 0% and 24-month LF 20.7% vs 0%, p = 0.002). OS at 12 and 24 months was 76% (95% CI 66% to 87%) and 52% (95% CI 40% to 67%), respectively. On univariable analysis, OS was significantly higher for patients with oligometastatic disease (12-month OS 85% vs 66%, p < 0.001, HR [95% CI] 0.29 [0.14, 0.59]) and Karnofsky Performance Status ≥ 90 (12-month OS 83 vs 63%, p =.03, HR [95% CI] 0.48 [0.24, 0.93]) but not age, sex, or time between initial pathologic diagnosis and SBRT. Among patients with oligometastatic disease, the median time to next systemic therapy or last follow-up was 10.0 months (range: 1 to 44.4 months). Three patients (4.3%) had grade 2 pneumonitis, and one patient (1.4%) had grade 2 esophagitis. No patients had ≥ grade 3+ toxicity. To the best of our knowledge, this is the largest series of patients treated with SBRT for pulmonary sarcoma metastases. SBRT offers a safe alternative to surgical resection with excellent local control. Minimal toxicity was observed. Patients with oligometastatic disease had prolonged survival after SBRT. [ABSTRACT FROM AUTHOR]

Objective: We evaluate the clinical feasibility of a portable, low-field magnetic resonance imaging (MRI) system for prostate cancer (PCa) biopsy., Methods: A retrospective analysis of men who underwent a 12-core systematic transrectal ultrasound-guided prostate biopsy (SB) and a low-field MRI guided transperineal targeted biopsy (MRI-TB). Comparison of the detection of clinically significant PCa (csPCa) (Gleason Grade [GG] ≥ 2) by SB and low field MRI-TB, stratified by Prostate Imaging Reporting & Data System (PI-RADS) score, prostate volume, and prostate serum antigen (PSA) was performed., Results: A total of 39 men underwent both the MRI-TB and SB biopsy. Median (interquartile range [IQR]) age was 69.0 (61.5-73) years, body mass index (BMI) was 28.9 kg/m 2 (25.3-34.3), prostate volume was 46.5 cc (32-72.7), and PSA was 9.5 ng/ml (5.5-13.2). The majority (64.4%) of patients had PI-RADS ≥ 4 lesions and 25% of lesions were anterior on pre-biopsy MRII. Cancer detection rate (CDR) was greatest when combining SB and MRI-TB (64.1%). MRI-TB detected 74.3% (29/39) cancers. Of which, 53.8% (21/39) were csPCa while SB detected 42.5% (17/39) csPCa (p = 0.21). In 32.5% (13/39) of cases, MRI-TB upstaged the final diagnosis, compared to 15% (6/39) of cases in which SB upstaged the final diagnosis (p = 0.11)., Conclusion: Low-field MRI-TB is clinically feasible. Although future studies on the accuracy of MRI-TB system are needed, the initial CDR is comparable to those seen with fusion-based prostate biopsies. A transperineal and targeted approach may be beneficial in patients with higher BMI and anterior lesions., (© 2023 Wiley Periodicals LLC.)

This paper describes the workflow of transperineal prostate biopsy (TBx) using the single-sided, low-field Promaxo MRI system (Promaxo Inc., Oakland, California, United States) operating at a field strength ranging between 58 and 74 millitesla (mT). Prostate cancer (PCa) is the leading cause of cancer-related death and the second most frequently diagnosed cancer in men. Systematic biopsy (SBx) with 12-14 cores is the preferred standard of care procedure. The blinded approach of SBx, however, results in several shortcomings, including high rates of false negatives and increased infection rates due to the transrectal approach. The evolution of clinical use and scientific research using different prostate biopsy modalities is discussed, including the potential for the Promaxo MRI system to mitigate logistical constraints often associated with standard magnetic resonance (MR)-guided biopsy through the utilization of an office-based, low-field MRI., Competing Interests: Promaxo Inc. has several patents associated with magnet design, function, clinical applications, and reconstruction algorithms. Poorvi Satya is a former employee and current consultant at Promaxo Inc. concurrently with her current status as a student at Columbia University, (Copyright © 2022, Satya et al.)

Purpose: Prostate cancer is the second most prevalent cancer in US men, with about 192,000 new cases and 33,000 deaths predicted for 2020. With only a 31% 5-year survival rate for patients with an initial diagnosis of stage-four prostate cancer, the necessity for early screening and diagnosis is clear. In this paper, we present navigation accuracy results for Promaxo's MR system intended to be used in a physician's office for image-guided transperineal prostate biopsy., Methods: The office-based low-field MR system was used to acquire images of prostate phantoms with needles inserted through a transperineal template. Coordinates of the estimated sample core locations in the office-based MR system were compared to ground truth needle coordinates identified in a 1.5T external reference scan. The error was measured as the distance between the planned target and the ground truth core center and as the shortest perpendicular distance between the planned target and the ground truth trajectory of the whole core., Results: The average error between the planned target and the ground truth core center was 2.57 ± 1.02 mm, [1.93-3.21] 95% CI. The average error between the planned target to the actual core segment was 2.05 ± 1.24 mm, [1.53-2.56] 95% CI., Conclusion: The average navigation errors were below the clinically significant threshold of 5 mm. The initial phantom results demonstrate the feasibility of the office-based system for prostate biopsy.

The principle of magnetic drug targeting, wherein therapy is attached to magnetically responsive carriers and magnetic fields are used to direct that therapy to disease locations, has been around for nearly two decades. Yet our ability to safely and effectively direct therapy to where it needs to go, for instance to deep tissue targets, remains limited. To date, magnetic targeting methods have not yet passed regulatory approval or reached clinical use. Below we outline key challenges to magnetic targeting, which include designing and selecting magnetic carriers for specific clinical indications, safely and effectively reaching targets behind tissue and anatomical barriers, real-time carrier imaging, and magnet design and control for deep and precise targeting. Addressing these challenges will require interactions across disciplines. Nanofabricators and chemists should work with biologists, mathematicians, and engineers to better understand how carriers move through live tissues and how to optimize carrier and magnet designs to better direct therapy to disease targets. Clinicians should be involved early on and throughout the whole process to ensure the methods that are being developed meet a compelling clinical need and will be practical in a clinical setting. Our hope is that highlighting these challenges will help researchers translate magnetic drug targeting from a novel concept to a clinically available treatment that can put therapy where it needs to go in human patients., (© 2014 Wiley Periodicals, Inc.)

In magnetic drug delivery, therapeutic magnetizable particles are typically injected into the blood stream and magnets are then used to concentrate them to disease locations. The behavior of such particles in-vivo is complex and is governed by blood convection, diffusion (in blood and in tissue), extravasation, and the applied magnetic fields. Using physical first-principles and a sophisticated vessel-membrane-tissue (VMT) numerical solver, we comprehensively analyze in detail the behavior of magnetic particles in blood vessels and surrounding tissue. For any blood vessel (of any size, depth, and blood velocity) and tissue properties, particle size and applied magnetic fields, we consider a Krogh tissue cylinder geometry and solve for the resulting spatial distribution of particles. We find that there are three prototypical behaviors (blood velocity dominated, magnetic force dominated, and boundary-layer formation) and that the type of behavior observed is uniquely determined by three non-dimensional numbers (the magnetic-Richardson number, mass Péclet number, and Renkin reduced diffusion coefficient). Plots and equations are provided to easily read out which behavior is found under which circumstances (Figures 5, 6, 7, and 8). We compare our results to previously published in-vitro and in-vivo magnetic drug delivery experiments. Not only do we find excellent agreement between our predictions and prior experimental observations, but we are also able to qualitatively and quantitatively explain behavior that was previously not understood.