Temperature Dynamics in Rat Brains Exposed to Near-Field Waveguide Outputs at 2.8 GHz.

Biological effects in the microwave band of the radiofrequency (RF) spectrum are thermally mediated. For acute high-power microwave exposures, these effects will depend on transient time-temperature histories within the tissue. In this article, we summarize the transient temperature response of rats exposed to RF energy emanating from an open-ended rectangular waveguide. These exposures produced specific absorption rates of approximately 36 and 203 W/kg in the whole body and brain, respectively. We then use the experimentally measured thermal data to infer the baseline perfusion rate in the brain and modify a custom thermal modeling tool based upon these findings. Finally, we compare multi-physics simulations of rat brain temperature against empirical measurements in both live and euthanized subjects and find close agreement between model and experimentation. This research revealed that baseline brain perfusion rates in rat subjects could be larger than previously assumed in the RF thermal modeling literature, and plays a significant role in the transient thermal response to high-power microwave exposures. © 2021 Bioelectromagnetics Society.

Implementation of an adult code sepsis protocol and its impact on SEP-1 core measure perfect score attainment in the ED.

INTRODUCTION: Timely management of sepsis has become an urgent concern among most hospitals. Institutions have been searching for unique ways to increase the quality of care and timely adherence to proven therapies. The objective of this study was to determine the impact of an Adult Code Sepsis Protocol on the rate of SEP-1 perfect score attainment (PSA) among patients who presented to the emergency department (ED) with severe sepsis or septic shock, as defined by the Centers for Medicare and Medicaid Services (CMS). METHODS: This was a retrospective, observational cohort study in a 35-bed tertiary care hospital ED from December 2016 to February 2018. Adults (≥18 years of age) who met the CMS-case definition of severe sepsis or septic shock presenting to the ED either prior to or after implementation of an Adult Code Sepsis Protocol were included. RESULTS: The primary outcome of SEP-1 PSA, which was abstracted in an all-or-none fashion, increased from 30.7% to 71.3% (p < 0.001). Inpatient mortality was reduced from 4% to 0% (p = 0.011) after protocol implementation. Protocol initiation also resulted in a significant reduction in both time to initiation of appropriate, empiric and effective antimicrobial therapy, based on culture results by 48 and 111 min, respectively (p < 0.001). There were no significant differences in other secondary outcomes including ICU length-of-stay, readmission, or economic outcome measures. CONCLUSIONS: The addition of an Adult Code Sepsis Protocol in the ED significantly increased the rate of SEP-1 PSA, reduced inpatient mortality, and improved the time to initiation of effective antimicrobial therapy.

A pilot study of nintedanib in molecularly selected patients with advanced non-small cell lung cancer.

Background: Nintedanib is a small molecule tyrosine kinase inhibitor (TKI) targeting vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), and fibroblast growth factor receptor (FGFR). The purpose of the study was to evaluate the response rate for patients with advanced non-small cell lung cancer (NSCLC) with mutations in TP53, VEGFR1-3, PDGFR-A, PDGFR-B, and FGFR1-3 treated with nintedanib as part of an open-label, single-arm pilot study. Methods: Patients with advanced NSCLC previously treated with platinum-doublet chemotherapy with the above mutations were enrolled. Exclusion criteria included necrotic tumors with invasion of blood vessels, history of recent thromboembolic events, increased risk of bleeding or thrombosis, myocardial infarction, and weight loss >10% within past 6 months. Nintedanib was administered at a dose of 200 mg orally twice daily until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) by Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. Secondary endpoints included progression-free survival (PFS) and correlating outcomes with specific mutations. This study was registered with ClinicalTrials.gov, number NCT02299141. Results: Between 2015 and 2019, 20 patients were enrolled with a median age was 66 years, 15 (75%) were females, 15 (75%) had adenocarcinoma, and 17 patients had a TP53 mutation (85%). Seventeen (85%) had received prior immunotherapy and 11 (55%) had received at least three prior lines of systemic therapy. The ORR was 15% with three partial responses (PR), while 12 patients had stable disease (SD), with disease control rate (DCR) consisting of a PR and SD greater than or equal to 16 weeks of 65% (n=13). Median PFS was 4.3 months [95% confidence interval (CI): 1.8-7.9] and median overall survival (OS) was 11.3 months (95% CI: 3.5-44.2). Three patients experienced prolonged clinical benefit from nintedanib, remaining on treatment for over 1 year and all three had a TP53 mutation and received prior immunotherapy. The most common adverse events of any grade included nausea (80%), fatigue (70%), diarrhea (60%), and anorexia (60%). Conclusions: In this pilot study in heavily pretreated and molecularly selected patients with metastatic NSCLC, nintedanib showed modest activity.

Dilation of the superior sagittal sinus detected in rat model of mild traumatic brain injury using 1 T magnetic resonance imaging.

Introduction: Mild traumatic brain injury (mTBI) is a common injury that can lead to temporary and, in some cases, life-long disability. Magnetic resonance imaging (MRI) is widely used to diagnose and study brain injuries and diseases, yet mTBI remains notoriously difficult to detect in structural MRI. mTBI is thought to be caused by microstructural or physiological changes in the function of the brain that cannot be adequately captured in structural imaging of the gray and white matter. However, structural MRIs may be useful in detecting significant changes in the cerebral vascular system (e.g., the blood-brain barrier (BBB), major blood vessels, and sinuses) and the ventricular system, and these changes may even be detectable in images taken by low magnetic field strength MRI scanners (<1.5T). Methods: In this study, we induced a model of mTBI in the anesthetized rat animal model using a commonly used linear acceleration drop-weight technique. Using a 1T MRI scanner, the brain of the rat was imaged, without and with contrast, before and after mTBI on post-injury days 1, 2, 7, and 14 (i.e., P1, P2, P7, and P14). Results: Voxel-based analyses of MRIs showed time-dependent, statistically significant T2-weighted signal hypointensities in the superior sagittal sinus (SSS) and hyperintensities of the gadolinium-enhanced T1-weighted signal in the superior subarachnoid space (SA) and blood vessels near the dorsal third ventricle. These results showed a widening, or vasodilation, of the SSS on P1 and of the SA on P1-2 on the dorsal surface of the cortex near the site of the drop-weight impact. The results also showed vasodilation of vasculature near the dorsal third ventricle and basal forebrain on P1-7. Discussion: Vasodilation of the SSS and SA near the site of impact could be explained by the direct mechanical injury resulting in local changes in tissue function, oxygenation, inflammation, and blood flow dynamics. Our results agreed with literature and show that the 1T MRI scanner performs at a level comparable to higher field strength scanners for this type of research.

Noninvasive Techniques for the Determination of Burn Severity in Real Time.

Visual diagnosis of second-degree burns has proven inadequate for determining the appropriate treatment regimen. Although multiple noninvasive imaging techniques have shown promise for providing information about burn wound severity, the ideal technology to aid burn wound excision would provide real-time readouts. Herein, the authors examine a high-resolution infrared (IR) camera (thermography) and a multiprobe adapter system (MPAS-6; transepidermal evaporative water loss, colorimetry) to assess their usefulness in predicting burn severity. Contact burn wounds of increasing severity were created in a porcine model. Wounds were assessed for 4 days with an IR camera and MPAS-6. In addition, each day, the burn wounds were biopsied for histological analysis to determine burn depth for correlation with noninvasive measures. Surface temperatures decreased with increasing burn severity, which was associated with increasing transepidermal evaporative water loss. Melanin content correlated with the depth of collagen coagulation and was bimodal, with superficial and full-thickness burns having higher values than deep partial thickness wounds. Erythema content was highest in superficial burns and negatively correlated with necrosis (high-mobility group box protein 1 expression). Importantly, surface temperature taken on every single day after injury was predictive of all histologically determined measurements of burn depth (ie, collagen coagulation, apoptosis, necrosis, vascular occlusion). The results indicate that IR imaging and skin quality probes can be used to support the diagnosis of burn severity. Most importantly, IR measurements gave insight into both the zone of coagulation and the zone of stasis on every postburn day studied.

How can a postgraduate professional education and development course benefit general practitioners?: a qualitative study.

PURPOSE: The rationale for 'professional education and development' (PED) courses is to support general practitioners, enabling them to access a range of theoretical and practical skills within a supportive schema. It aims to identify whether and how a regional PED course has had a beneficial impact upon participants. METHODS: The study comprised a qualitative investigation of participants' assessed coursework portfolios. The content of each portfolio gives individual accounts of the impact of the course on personal and practice development. Permission to access extant portfolios was obtained from 16 recent alumni of the course. The anonymous written material was analysed by the research team for recurring discourses and themes using a thematic framework analysis. RESULTS: Seven major thematic categories were extrapolated from the data: leadership, resilience, quality improvement, change management, development of new services, educational expertise, and patient safety. In each category, we found evidence that the course enabled development of practitioners by enhancing knowledge and skills which had a positive impact upon their self-perceived effectiveness and motivation. CONCLUSION: Extended specialty training is on the horizon but such courses may still serve a valuable purpose for current trainees and the existing general practitioners workforce which will be responsible for leading the shift towards community-based service delivery.