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Magnetic nanoparticles (MNPs) are used extensively across numerous disciples, with applications including Magnetic Particle Imaging (MPI), targeted hyperthermia, deep brain stimulation, immunoassays, and thermometry. The assessment of MNPs, especially those being designed for MPI, is performed with magnetic particle spectrometers, relaxometers, loop tracers, or similar devices. Despite the many applications and the need for particle assessment, there are few consolidated resources for designing or building such a MNP assessment system. Here, we describe the design and performance of an open-source device capable of spectroscopy, relaxometry, and loop tracing. We show example measurements from the device and quantify the detection sensitivity by measuring a dilution series of Synomag-D 70 nm (from 0.5 mg Fe/ml to 7 ng Fe/ml) with a 10 mT drive field at 23.8 kHz. The device measures 260 pg Fe with SNR = 1 and 1.3 ng at SNR = 5 in spectroscopy mode in under one second of measurement time. The system has a dynamic range of 60 μg to 260 pg Fe without changing the hardware configuration. As an example application, we characterize Synomag-D's relaxation time constant for drive fields 2–18 mT and compare the magnetization responses of two commonly used MNPs. [ABSTRACT FROM AUTHOR]

Although the behavioral differences of firms that internationalize rapidly from birth (born globals) are well documented, the effects of early internationalization on new venture strategy remains largely unexplored. Using a large sample of nascent entrepreneurs, we explore the relationship between internationalization level and founder emphasis on four key dimensions of business strategy (i.e., price, product scope (i.e., niche/focus), differentiation, and innovation). Our finding of support for a non-linear (inverted-U) relationship between internationalization level and strategy suggests that strategy differences between born globals and domestic firms decrease at higher levels of intended internationalization. [ABSTRACT FROM AUTHOR]

The relationships between Corporate Social Responsibility (CSR) and consumer behaviors have been widely explored in the literature. From the consumer standpoint, it has been shown that individuals largely want to be socially responsible actors and that, more than ever, they consider the CSR aspects of products or services when contemplating purchasing decisions. We utilize data from 23,247 online auctions conducted before and during the COVID-19 pandemic to analyze in what way consumer preferences might be influenced by how the CSR characteristics of products are touted in their descriptions. We find that a greater CSR emphasis is positively associated with an increased prospect of an online auction item selling. Additionally, we find CSR is valued more by consumers during a period of economic hardship and social uncertainty (COVID-19). Finally, we find that profit-seeking behaviors by intermediary auction house brokers undermine the effect of CSR on consumer purchasing behavior. [ABSTRACT FROM AUTHOR]

Many factors may influence entrepreneurial persistence in various contexts. For example, scholars find that family business entrepreneurs are more persistent than other entrepreneurs. However, the reasons why they are more persistent are not as well known. Utilizing a conjoint experiment with 64 entrepreneurs and 376 decisions, this paper examines the influence of socioemotional wealth (SEW) on persistence decisions in a family business context. The results of the Hierarchical Linear Modelling show that the expected financial returns, expected non-financial benefits, expected switching costs, and probability of expected outcomes influence entrepreneurial persistence decisions. Further, family business entrepreneurs with higher levels of SEW focus more on non-financial benefits when facing alternative opportunities. This study also provided empirical evidence for different dimensions of SEW. The results show that the emotional attachment of family members and the renewal of family bonds to the firm are effective indicators, which provide a direct measurement of SEW. The findings of this study increase scholarly understanding of both entrepreneurial persistence literature founded in threshold theory and SEW literature. [ABSTRACT FROM AUTHOR]

The technological complexity of implantable arrhythmia management devices, specifically pacemakers and defibrillators, has increased dramatically since their introduction only a few decades ago. Patients with such devices are encountered much more frequently in hospitals and surgery centers, yet anesthesia provider knowledge of safe and proper management is often incomplete. Anesthesia textbooks and references may provide only short paragraphs on arrhythmia management devices that do not address important perioperative management strategies for this ever-growing patient population. It is no longer satisfactory to simply place a magnet over an implanted device during surgery and assume that this action protects the patient from harm due to electromagnetic interference from inappropriate device function. This AANA Journal course serves as a concise review of basic device function, the sources and effects of electromagnetic interference in the operative setting, and patient management recommendations from current literature. [ABSTRACT FROM AUTHOR]

An abstract of the article "Explaining Conflicts Among Stakeholders in Social Enterprises" by Jason D'Mello, Trayan Kushev and Shaunn Mattingly is presented.

Magnetic fields switching at kilohertz frequencies induce electric fields in the body that can cause peripheral nerve stimulation (PNS). Magnetically induced PNS, i.e. magnetostimulation, has been extensively studied below 10 kHz. It is widely characterized using a hyperbolic strength-duration curve (SDC), where the PNS thresholds monotonically decrease with frequency. The very few studies performed at higher frequencies found significant deviations from the hyperbolic SDC above ~ 25 kHz, however, those measurements are sparse and show large variability. We fill the gap in the data by measuring PNS in the head of 8 volunteers using a solenoidal coil at 16 frequencies between 200 Hz and 88.1 kHz. Contrary to the hyperbolic SDC, PNS thresholds did not decrease monotonically with frequency, but reached a minimum ~ 25 kHz. The thresholds then increased by 39% from 25 kHz to 88.1 kHz on average across subjects. Our measurements can be used for guidance and validation of neurodynamic models and to inform PNS limits of magnetic resonance imaging (MRI) gradient coils and magnetic particle imaging (MPI) systems. The observed deviation of the experimentally measured thresholds from the hyperbolic SDC calls for further study of the underlying biological mechanisms of magnetostimulation beyond 25 kHz., Competing Interests: Competing Interests Statement The author(s) declare no competing interests.

Objective. Non-invasive functional brain imaging modalities are limited in number, each with its own complex trade-offs between sensitivity, spatial and temporal resolution, and the directness with which the measured signals reflect neuronal activation. Magnetic particle imaging (MPI) directly maps the cerebral blood volume (CBV), and its high sensitivity derives from the nonlinear magnetization of the superparamagnetic iron oxide nanoparticle (SPION) tracer confined to the blood pool. Our work evaluates functional MPI (fMPI) as a new hemodynamic functional imaging modality by mapping the CBV response in a rodent model where CBV is modulated by hypercapnic breathing manipulation. Approach. The rodent fMPI time-series data were acquired with a mechanically rotating field-free line MPI scanner capable of 5 s temporal resolution and 3 mm spatial resolution. The rat's CBV was modulated for 30 min with alternating 5 min hyper-/hypocapnic states, and processed using conventional fMRI tools. We compare our results to fMRI responses undergoing similar hypercapnia protocols found in the literature, and reinforce this comparison in a study of one rat with 9.4T BOLD fMRI using the identical protocol. Main results. The initial image in the time-series showed mean resting brain voxel SNR values, averaged across rats, of 99.9 following the first 10 mg kg -1 SPION injection and 134 following the second. The time-series fit a conventional General Linear Model with a 15%-40% CBV change and a peak pixel CNR between 12 and 29, 2-6× higher than found in fMRI. Significance. This work introduces a functional modality with high sensitivity, although currently limited spatial and temporal resolution. With future clinical-scale development, a large increase in sensitivity could supplement other modalities and help transition functional brain imaging from a neuroscience tool focusing on population averages to a clinically relevant modality capable of detecting differences in individual patients., (Creative Commons Attribution license.)

Background: Cognitive-communication impairments following acquired brain injury (ABI) can have devastating effects on a person's ability to participate in community, social, vocational, and academic preinjury roles and responsibilities. Guidelines for evidence-based practices are needed to assist speech-language pathologists (SLPs) and other rehabilitation specialists in the delivery of cognitive rehabilitation for the adult population., Purpose: The American Speech-Language-Hearing Association, in conjunction with a multidisciplinary panel of subject matter experts, developed this guideline to identify best practice recommendations for the delivery of cognitive rehabilitation to adults with cognitive dysfunction associated with ABI., Method: A multidisciplinary panel identified 19 critical questions to be addressed in the guideline. Literature published between 1980 and 2020 was identified based on a set of a priori inclusion/exclusion criteria, and main findings were pooled and organized into summary of findings tables. Following the principles of the Grading of Recommendations Assessment, Development and Evaluation Evidence to Decision Framework, the panel drafted recommendations, when appropriate, based on the findings, overall quality of the evidence, balance of benefits and harms, patient preferences, resource implications, and the feasibility and acceptability of cognitive rehabilitation., Recommendations: This guideline includes one overarching evidence-based recommendation that addresses the management of cognitive dysfunction following ABI and 11 subsequent recommendations focusing on cognitive rehabilitation treatment approaches, methods, and manner of delivery. In addition, this guideline includes an overarching consensus-based recommendation and seven additional consensus recommendations highlighting the role of the SLP in the screening, assessment, and treatment of adults with cognitive dysfunction associated with ABI. Future research considerations are also discussed.

Breast-conserving surgery (BCS) is a commonly utilized treatment for early stage breast cancers but has relatively high reexcision rates due to post-surgical identification of positive margins. A fast, specific, sensitive, easy-to-use tool for assessing margins intraoperatively could reduce the need for additional surgeries, and while many techniques have been explored, the clinical need is still unmet. We assess the potential of Magnetic Particle Imaging (MPI) for intraoperative margin assessment in BCS, using a passively or actively tumor-targeted iron oxide agent and two hardware devices: a hand-held Magnetic Particle detector for identifying residual tumor in the breast, and a small-bore MPI scanner for quickly imaging the tumor distribution in the excised specimen. Here, we present both hardware systems and demonstrate proof-of-concept detection and imaging of clinically relevant phantoms.

The technological complexity of implantable arrhythmia management devices, specifically pacemakers and defibrillators, has increased dramatically since their introduction only a few decades ago. Patients with such devices are encountered much more frequently in hospitals and surgery centers, yet anesthesia provider knowledge of safe and proper management is often incomplete. Anesthesia textbooks and references may provide only short paragraphs on arrhythmia management devices that do not address important perioperative management strategies for this ever-growing patient population. It is no longer satisfactory to simply place a magnet over an implanted device during surgery and assume that this action protects the patient from harm due to electromagnetic interference from inappropriate device function. This AANA Journal course serves as a concise review of basic device function, the sources and effects of electromagnetic interference in the operative setting, and patient management recommendations from current literature.

Dislocation fracture of the tarsometatarsal joint is a rare but devastating injury that presents a great challenge to the podiatric surgeon. A case of Lisfranc's dislocation is presented that was further complicated by the 7-month interval between injury and diagnosis. Because of this interval and the resultant degenerative change that ensued in the tarsometatarsal articulation, surgical arthrodesis of these joints was attempted with combined use of bone screws and Kirschner wire internal fixation. Results of surgery were excellent with anatomical realignment of Lisfranc's articulation and the return of all preinjury physical activities 8 months postoperatively.