Nanomaterials Research at a Primarily Undergraduate Institution: Transforming Nanorods, Undergraduate Research Communities, and Infrastructure.

Undergraduate research transforms student's conceptions of themselves as scientists and encourages participation and retention in science, technology, engineering, and mathematics (STEM) fields. Many barriers exist to carrying out scientifically impactful undergraduate research in nanomaterials at primarily undergraduate institutions (PUIs). Here, we share several practices and design principles that demonstrate pathways to overcome these barriers. Design of modular research projects with low entry barriers is essential. Postsynthetic transformation of nanoparticles is a field that enables such design and has been used successfully to advance nanoscience research while being achievable within undergraduate laboratories. Relatively large, inclusive research communities can be supported through the creation of opportunities with peer- and near-peer mentoring. We also share emerging strategies for enabling routine undergraduate access to transmission electron microscopy, which is one of the most mainstream characterization techniques in nanoscience yet is frequently absent from the infrastructure at undergraduate-focused institutions.

Functional outcomes more than 5 years following acetabulum fracture.

OBJECTIVES: The purposes of this project were to evaluate functional outcomes more than 5 years after acetabulum fracture and to determine factors related to function. METHODS: This retrospective study consisted of 205 adult patients treated for acetabulum fracture who completed the Musculoskeletal Function Assessment (MFA) a minimum of 5 years following injury. The MFA includes survey of daily activities, gross and fine mobility, social and work function, sleeping, and mood. Higher scores indicate worse function. RESULTS: Two hundred five patients with 210 fractures, 69.3% of whom were male, with mean age of 45.7 and mean body mass index 30.1 were included after mean 128 months follow-up. Fracture patterns included OTA/AO 62A (37.1%), 62B (40.5%), or 62C (22.4%), and 80.0% were treated surgically. Late complications were noted in 35.2%, including posttraumatic arthrosis (PTA: 19.5%), osteonecrosis and/or heterotopic ossification. Mean MFA of all patients was 31.4, indicating substantial residual dysfunction. Worse MFA scores were associated with morbid obesity (body mass index >40: 42.3, P>.09), and current tobacco smoking history vs former smoker vs nonsmoker (45.2 vs 36.1 vs 23.0, P < .002). Patients with late complications had worse mean MFA scores (38.7 vs 27.7, P = .001); PTA was the most common late complication, occurring in 19.5%. CONCLUSIONS: More than 5 years following acetabulum fracture, substantial residual dysfunction was noted, as demonstrated by mean MFA. Worse outcomes were associated with late complications and tobacco smoking. While fracture pattern was not associated with outcome, those patients who had late complications, mostly PTA, had worse outcomes.

Low-Frequency Entrainment to Visual Motion Underlies Sign Language Comprehension.

When people listen to speech, neural activity tracks the entropy fluctuation in the acoustic envelope of the signal. This signal-based entrainment has been shown to be the basis of speech parsing and comprehension. In this electroencephalography (EEG) study, we compute sign language users' cortical tracking of changes in visual dynamics of the communicative signal in the time-direct videos of sign language, and their time-reversed counterparts, and assess the relative contribution of response frequencies between.2 and 12.4 Hz to comprehension using a machine learning approach to brain state classification. Lower frequencies of EEG response (.2-4 Hz) yield 100% classification accuracy, while information about cortical tracking of the visual envelope in higher frequencies is less informative. This suggests that signers rely on lower visual frequency data, such as envelope of visual signal, for sign language comprehension. In the context of real-time language processing, given the speed of comprehension responses, this suggests that fluent signers employ a predictive processing heuristic based on sign language knowledge.

Intermittent fasting 5:2 diet: What is the macronutrient and micronutrient intake and composition?

BACKGROUND & AIM: Intermittent fasting (IF) is a dietary intervention that has been investigated as an alternative weight-loss diet due to conventional approaches having poor long-term adherence. However, the macronutrient and micronutrient intake and composition of IF diets have been overlooked. The primary aim of this study was to describe the macronutrient and micronutrient intake of individuals following the 5:2 intermittent fasting diet (IF 5:2). METHODS: Thirty eight overweight and obese participants were included from two previous studies of IF 5:2. The participants selected included 27 males and 11 females, with and without Type 2 Diabetes. The dietary intervention, IF 5:2, consisted of two days per week fasting, either consecutive or non-consecutive, and five days per week of habitual intake. Prospectively completed 4-day estimated food records were used to assess macronutrient and micronutrient intake at baseline and week six. The 4-day records were weighted to give a mean daily intake during IF 5:2. RESULTS: During IF 5:2 the median (25th, 75th quartile) daily macronutrient composition was 22 (19, 24)% from protein, 33 (29, 37)% from fat and 39 (36, 43)% from carbohydrates. The intake (g/d) of carbohydrates and fibre decreased significantly from baseline to week six (p < 0.001) as well as on fasting days compared to non-fasting days (p < 0.001). The intake of calcium, zinc, magnesium and potassium were lower than recommended guidelines. Sodium intake exceeded the suggested daily target. On fasting days, the percent of total energy from protein significantly increased from 21% to 25% (p = 0.02). Despite intake being unrestricted on non-fasting days the energy intake decreased by week six when compared with baseline. CONCLUSION: The composition of IF 5:2 was a high protein, moderate fat, low carbohydrate diet with a low fibre intake. Some micronutrients have lower than recommended intake. However, overall IF 5:2 is a safe acceptable weight-loss diet strategy.

Nerve Injury With Acetabulum Fractures: Incidence and Factors Affecting Recovery.

OBJECTIVES: To determine factors associated with nerve injury after acetabulum fracture and to evaluate recovery and outcomes. DESIGN: Retrospective cohort study. SETTING: Level 1 trauma center. PATIENTS AND PARTICIPANTS: Nine hundred seventy-five skeletally mature patients with acetabulum fracture. INTERVENTION: Operative and nonoperative management. MAIN OUTCOME MEASUREMENTS: Nerve injuries, categorized as traumatic or iatrogenic, recovery (none, partial, or complete), and patient-reported functional outcomes with the Musculoskeletal Function Assessment (n = 353, 36.2%). RESULTS: Thirty-two patients (3.3%) experienced nerve injury with 24 (78%) resulting from trauma and 23 with an associated posterior hip dislocation. Eight injuries (25%) were iatrogenic. Thirty-one (97%) occurred in patients with operative fractures (n = 738). The most common fracture pattern associated with nerve injury was transverse posterior wall (31% of injuries). Obesity was more common in patients with nerve injuries (59% vs. 30% in those without nerve injury (P = 0.001), but was not related to age or sex. Sixty-five percent of sciatic nerve injuries were to the common peroneal division only, while none were isolated to the tibial division. All iatrogenic injuries occurred after the ilioinguinal approach (P < 0.001). Overall, 50% experienced partial nerve recovery and 22% had complete recovery. However, 24% of patients with sciatic or common peroneal injuries had no recovery. Thirty-three percent of tobacco smokers experienced no recovery (vs. 26% of nonsmokers). Average Musculoskeletal Function Assessment scores for patients with nerve injuries was 32, similar to those without (33). CONCLUSIONS: Posterior acetabulum fracture dislocations are associated with traumatic nerve injury, although 25% of nerve injuries were iatrogenic. Nerve injuries are more common in obese patients. More than one-quarter of patients had no recorded nerve recovery. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Flow-Pattern Details in an Aneurysm Model Using High-Speed 1000-Frames-per-Second Angiography.

Traditional digital subtraction angiography provides rather limited evaluation of contrast flow dynamics when studying and treating intracranial brain aneurysms. A 1000-frames-per-second photon-counting x-ray detector was used to image detailed iodine-contrast flow patterns in an internal carotid artery aneurysm of a 3D-printed vascular phantom. High-speed imaging revealed differences in vortex and inflow patterns with and without a Pipeline Embolization Device flow diverter in more detail and clarity than could be seen in standard pulsed angiography. Improved temporal imaging has the potential to impact the outcomes of endovascular interventions by allowing clinicians to better understand and act on flow dynamics in real-time.

High-Definition Zoom Mode, a High-Resolution X-Ray Microscope for Neurointerventional Treatment Procedures: A Blinded-Rater Clinical-Utility Study.

BACKGROUND AND PURPOSE: Quality of visualization of treatment devices during critical stages of endovascular interventions, can directly impact their safety and efficacy. Our aim was to compare the visualization of neurointerventional procedures and treatment devices using a 194-µm pixel flat panel detector mode and a 76-µm pixel complementary metal oxide semiconductor detector mode (high definition) of a new-generation x-ray detector system using a blinded-rater study. MATERIALS AND METHODS: Deployment of flow-diversion devices for the treatment of internal carotid artery aneurysms was performed under flat panel detector and high-definition-mode image guidance in a neurointerventional phantom simulating patient cranium and tissue attenuation, embedded with 3D-printed intracranial vascular models, each with an aneurysm in the ICA segment. Image-sequence pairs of device deployments for each detector mode, under similar exposure and FOV conditions, were evaluated by 2 blinded experienced neurointerventionalists who independently selected their preferred image on the basis of visualization of anatomic features, image noise, and treatment device. They rated their selection as either similar, better, much better, or substantially better than the other choice. Inter- and intrarater agreement was calculated and categorized as poor, moderate, and good. RESULTS: Both raters demonstrating good inter- and intrarater agreement selected high-definition-mode images with a frequency of at least 95% each and, on average, rated the high-definition images as much better than flat panel detector images with a frequency of 73% from a total of 60 image pairs. CONCLUSIONS: Due to their higher resolution, high-definition-mode images are sharper and visually preferred compared with the flat panel detector images. The improved imaging provided by the high-definition mode can potentially provide an advantage during neurointerventional procedures.

Gantry rotational motion-induced blur in cone-beam computed tomography.

As neuro-endovascular image-guided interventions (EIGIs) make use of higher resolution detectors, gantry rotational motion-induced blur becomes more noticeable in acquired projections as well as reconstructed images by reducing the visibility of vascular and device features whose visualization could be critical in the treatment of vascular pathology. Motion-induced blur in projections views is a function of an object's position in the field-of-view (FOV), gantry rotational speed, and frame capture or exposure time. In this work different frame rates were used to investigate the effects of blurring from individual projections on the reconstructed image. To test the effects of these parameters on reconstructed images, a regular pattern phantom of small objects was simulated and projection views were generated at various different frame rates for a given simulated rotational velocity. The reconstruction was made using a linear interpolation of filtered backprojections. Images reconstructed from lower frame rates showed significant blurring in the azimuthal direction, increasingly worse towards the periphery of the image. However, those reconstructed from higher frame rates showed significantly less blur throughout the entire FOV. While lower frame rates could be used with slower gantry speeds this would increase the risk of voluntary or involuntary patient motion contributing to blur over the entire FOV. A high frame rate used with high gantry speeds could reliable provide images without gantry-motion blur while reducing the risk of patient-motion blur. Frame rates exceeding 2000 fps available with photon counting detectors such as the X-counter Actaeon1 are available.

Evaluation of a new photon-counting imaging detector (PCD) with various acquisition modes.

The prospect of improved low noise, high speed, and dual-energy imaging that may be associated with the use of photon-counting imaging detectors (PCD) has motivated this evaluation of a newly upgraded version of a prototype PCD. The XCounter Actaeon was evaluated in its four acquisition modes each based upon varying signal processing firmware including a mode with charge sharing correction that enables neighboring pixels that share the energy from one incident x-ray photon detection to be counted only once at the proper summed energy in the pixel with the largest charge deposition. Since this PCD is a CdTe-based direct detector with 100 µm pixels, such charge sharing for typical medical x-ray energy photons may occur frequently and must be corrected to achieve more accurate counts. This charge sharing correction is achieved with an Anti-Coincidence Circuit (ACC) which prevents double pixel counting from one event as well as prevents counting from either event if they are below a preset threshold. Various physical parameters of the PCD were evaluated including linearity, sensitivity, pulse pile-up effects, dark noise, spatial resolution, noise power spectrum, and detective quantum efficiency.

Initial investigations of a special high-definition (Hi-Def) zoom capability in a new detector system for neuro-interventional procedures.

Real-time visualization of fine details ranging to 100 um or less in neuro-vascular imaging guided interventions is important. A separate high-resolution detector mounted on a standard flat panel detector (FPD) was previously reported. This device had to be rotated mechanically into position over the FPD for high resolution imaging. Now, the new detector reported here has a high definition (Hi-Def) zoom capability along with the FPD built into one unified housing. The new detector enables rapid switching, by the operator between Hi-Def and FPD modes. Standard physical metrics comparing the new Hi-Def modes with those of the FPD are reported, demonstrating improved imaging resolution and noise capability at patient doses similar to those used for the FPD. Semi-quantitative subjective studies involving qualitative clinician feedback on images of interventional devices such as a Pipeline Embolization Device (PED) acquired in both Hi-Def and FPD modes are presented. The PED is deployed in a patient specific 3D printed neuro-vascular phantom embedded inside realistic bone and with tissue attenuating material. Field-of-view (FOV), exposure and magnification were kept constant for FPD and Hi-Def modes. Static image comparisons of the same view of the PED within the phantom were rated by expert interventionalists who chose from the following ratings: Similar, Better, or Superior. Generally, the Hi-Def zoomed images were much preferred over the FPD, indicating the potential to improve endovascular procedures and hence outcomes using such a Hi-Def feature.