Dispersal distances from splash-cup plants depend on the cup's angle and contents.

Splash-cup plants disperse propagules via raindrops striking cup-shaped fruiting bodies. The seeds are ejected at velocities up to five times the impact speed of the raindrop and are dispersed up to 1 m from the parent plant. Here, we examine the effects of cup angles and the presence of seed mimics to understand the dynamics of this unique method of dispersal. Our findings demonstrate that: (i) cup angles that launched seeds the furthest ranged from approximately 30° to 50°, matching the range of angles seen in splash-cup plants. (ii) Seeds travel shorter distances than water droplets alone, and this distance depends on the number of seeds in the cup. (iii) Not all seeds are ejected from initially dry cups, leaving cups with some seeds and some water. (iv) Nearly all seeds are ejected from cups that contain both water and seeds, and those that are ejected travel significantly further than those from dry cups. These results confirm the possibility that the conical shape of splash cup plants may be adapted to maximize dispersal distance and benefit from multiple splash events. Our results also illustrate that future work on these plants should include seeds rather than water droplets alone.

Lower Extremity Hockey Puck Impaction Fractures in Professional Hockey Players: A Case Series and Review of the Literature.

Hockey is a contact sport notorious for injuries. The hockey puck is a projectile that can impart substantial energy when it impacts a player. Hockey puck impact is a frequent and underreported cause of injury. This case report describes the clinical course of 3 professional hockey players who sustained injuries to the lower leg and ankle from projectile hockey pucks. Each player sustained a unique injury with associated complications affecting return to play. We aim to bring attention to this injury mechanism that can cause significant morbidity among players.Levels of Evidence: IV.

A novel weight-drop closed head focal traumatic brain injury: A candidate to translational studies?

Traumatic brain injury (TBI) is a neurotrauma with a complex pathophysiology caused by an external mechanical force. This global public health problem is a leading cause of death and disability in young adults. In this scenario, many models were developed to try to simulate human TBI. The weight drop model allows the investigation of the pathophysiological cascades of TBI without surgical interference. In this protocol, a new closed-head weight-drop rat model consisting of a 48.5g weight projectile that free falls from 1.10m high onto the skull of the animals was built. We classify the present TBI model performed as moderately severe due to its mortality rate. Animals from TBI and Control (Sham) groups underwent weight for 7 days and temperature assessments within 1 hour after TBI and for 7 days. Results demonstrated that the TBI group showed less body weight gain in the days after the injury. Temperature oscillations within the first-hour post-injury and on the 3rd day after injury were observed. As the results of this study demonstrated similarity to human TBI vital parameters, this new adaptation of the Weight-drop model injury can be a suitable candidate for translational studies.•We developed a novel closed head focal traumatic brain injury using a projectile.•This TBI model does not require surgical intervention.•The validation of this method demonstrates that the vital parameters of the injured rats exhibit similarities with those of TBI patients.

Predicting projectile residual velocities using an advanced artificial neural network model.

In this research, we delve into the fascinating dynamics of projectiles and their interactions with materials, with a keen focus on residual velocity - the speed a projectile retains after striking a target. This parameter is pivotal, especially when considering the design of protective barriers in various environments. Traditional methods of gauging residual velocity have been cumbersome, resource-intensive, and occasionally inconsistent. To address these challenges, we introduce an innovative approach using an Artificial Neural Network (ANN) model through MATLAB R2021a. This computerized tool, trained on a rich dataset from prior research, can predict residual velocities by considering multiple factors, including the initial speed of the projectile, its material and shape, and the thickness of the target. This paper meticulously details the development, training, and validation of the ANN model, highlighting its superior accuracy when compared to traditional methods like the Recht-Ipson model. The developed ANN model demonstrated remarkable performance compared to the Recht-Ipson model. During training, it exhibited a Mean Absolute Percentage Error (MAPE) of 0.0259 and a Root Mean Squared Error (RMSE) of 1.5993. For validation, MAPE was 0.0295, and RMSE was 2.2056. In contrast, the Recht-Ipson model displayed higher errors, with MAPE and RMSE values of 0.2349 and 14.1791, respectively. Furthermore, we discuss the potential of the ANN model in predicting not just residual velocities but also absorbed energy, showcasing its versatility. The practical implications of our findings are vast. From designing safer infrastructures in urban settings to enhancing armour systems in military applications, the ANN model's predictions can be a cornerstone for innovation.

Roentgenoscopy of laser-induced projectile impact testing.

Laser-induced projectile impact testing (LIPIT) based on synchrotron imaging is proposed and validated. This emerging high-velocity, high-strain microscale dynamic loading technique offers a unique perspective on the strain and energy dissipation behavior of materials subjected to high-speed microscale single-particle impacts. When combined with synchrotron radiation imaging techniques, LIPIT allows for in situ observation of particle infiltration. Two validation experiments were carried out, demonstrating the potential of LIPIT in the roentgenoscopy of the dynamic properties of various materials. With a spatial resolution of 10 µm and a temporal resolution of 33.4 µs, the system was successfully realized at the Beijing Synchrotron Radiation Facility 3W1 beamline. This innovative approach opens up new avenues for studying the dynamic properties of materials in situ.

Biomechanics of insect flight stability and perturbation response.

Insects must fly in highly variable natural environments filled with gusts, vortices, and other transient aerodynamic phenomena that challenge flight stability. Furthermore, the aerodynamic forces that support insect flight are produced from rapidly oscillating wings of time-varying orientation and configuration. The instantaneous flight forces produced by these wings are large relative to the average forces supporting body weight. The magnitude of these forces and their time-varying direction add another challenge to flight stability, because even proportionally small asymmetries in timing or magnitude between the left and right wings may be sufficient to produce large changes in body orientation. However, these same large magnitude oscillating forces also offer an opportunity for unexpected flight stability through non-linear interactions between body orientation, body oscillation in response to time varying inertial and aerodynamic forces, and the oscillating wings themselves. Understanding the emergent stability properties of flying insects is a crucial step toward understanding the requirements for evolution of flapping flight and decoding the role of sensory feedback in flight control. Here we provide a brief review of insect flight stability, with some emphasis stability effects brought about by oscillating wings, and present some preliminary experimental data probing some aspects of flight stability in free-flying insects.

Traumatic penetrating head injury by crossbow projectiles: A case report and literature review.

Background: Low-energy penetrating head injuries caused by arrows are relatively uncommon. The objective of this report is to describe a case presentation and management of self-inflicted intracranial injury using a crossbow and to provide a relevant literature review. Case Report: A 31-year-old man with a previous psychiatric history sustained a self-inflicted injury using a crossbow that he bought from a department store. The patient arrived neurologically intact at the hospital, fully awake and oriented. He was not able to verbalize due to immobilization of the jaw as well as fixation of his tongue to his hard palate secondary to the position of the arrow. The trajectory of the object showed an entry point at the floor of the oral cavity and an exit through the calvarium just off the midline. The oral and nasal cavity, along with the palate and, the skull base of the anterior cranial fossa, and the left frontal lobe, were all breached. No vascular injury was identified clinically or in imaging. The arrow was surgically removed in the operating room after establishing an elective surgical airway. The floor of the mouth, tongue, and palate was repaired next. A planned delayed cerebrospinal fluid leak repair was performed. The patient made a substantial recovery and was discharged home in good functional status. A systematic literature search was done using Medline for cases with intracranial injuries related to crossbows to review and appraise the available literature. Conclusion: A thorough assessment in a multidisciplinary trauma center and the availability of a subspecialty care team, including neurosurgery and otolaryngology, are paramount in such cases. The vascular imaging should be done before and after any planned surgical intervention. Emergent and elective surgical airway management should be considered and made available throughout the stabilization and care of the acute injury. Surgical management should be planned to remove the object with adequate exposure to facilitate visualization, removal, and the possible need for further intervention, including anticipating aerodigestive and vascular injuries on removal. Finally, access to weapons and the relation to psychiatric illness should not be overlooked, as many reported cases are self-harming in nature.

Mechanism and outcomes of recreational and sports-related open globe injuries.

OBJECTIVES: To describe the mechanisms and visual outcomes of recreational and sports-related open globe injuries (OGIs). METHODS: A retrospective case series of eyes experiencing OGI secondary to recreational and sports-related activities at Memorial Hermann Hospital - Texas Medical Center (MHH-TMC) from January 1st, 2010 through March 31st, 2015 was conducted. Exclusionary criteria included no documented ophthalmologic examination upon presentation and repairs performed by services other than ophthalmology. A two-tailed t-test and Fisher's exact test were utilized to assess for statistical significance (p < 0.05). RESULTS: A total of 20 eyes from 20 patients experiencing OGIs secondary to recreational and sports-related activities were included. Thirteen eyes (65 %) presented with OGIs from penetrating objects while seven eyes (35 %) had injuries from blunt injuries. Males comprised most of the total study group (17 of 20 patients), and zone 3 injuries were the most common location of OGI. While eyes with OGIs from blunt trauma underwent evisceration/enucleation procedures more frequently than OGIs from penetrating mechanisms (71% vs 23 %) (p = 0.10), the final visual outcomes were similarly poor between groups. Only three eyes in this series experienced an improvement from baseline VA; all three eyes had lacked initial findings consistent with severe injury. CONCLUSIONS: Recreational and sports related OGIs most commonly occur in zone 3 and in young males, regardless of injury type. OGIs due to both penetrating and blunt trauma mechanisms implicate poor functional outcomes, but the absence of certain presenting injury features may indicate possibility of eventual visual recovery.

Identification and quantification of projectile impact marks on bone: new experimental insights using osseous points.

Shifts in projectile technology potentially document human evolutionary milestones, such as adaptations for different environments and settlement dynamics. A relatively direct proxy for projectile technology is projectile impact marks (PIM) on archaeological bones. Increasing awareness and publication of experimental data sets have recently led to more identifications of PIM in various contexts, but diagnosing PIM from other types of bone-surface modifications, quantifying them, and inferring point size and material from the bone lesions need more substantiation. Here, we focus on PIM created by osseous projectiles, asking whether these could be effectively identified and separated from lithic-tipped weapons. We further discuss the basic question raised by recent PIM research in zooarchaeology: why PIM evidence is so rare in archaeofaunal assemblages (compared to other human-induced marks), even when they are explicitly sought. We present the experimental results of shooting two ungulate carcasses with bone and antler points, replicating those used in the early Upper Paleolithic of western Eurasia. Half of our hits resulted in PIM, confirming that this modification may have been originally abundant. However, we found that the probability of a skeletal element to be modified with PIM negatively correlates with its preservation potential, and that much of the produced bone damage would not be identifiable in a typical Paleolithic faunal assemblage. This quantification problem still leaves room for an insightful qualitative study of PIM. We complement previous research in presenting several diagnostic marks that retain preservation potential and may be used to suggest osseous, rather than lithic, projectile technology. Supplementary Information: The online version contains supplementary material available at 10.1007/s12520-024-01944-3.

Death in the high mountains: Evidence of interpersonal violence during Late Chalcolithic and Early Bronze Age at Roc de les Orenetes (Eastern Pyrenees, Spain).

OBJECTIVES: To test a hypothesis on interpersonal violence events during the transition between Chalcolithic and Bronze Age in the Eastern Pyrenees, to contextualize it in Western Europe during that period, and to assess if these marks can be differentiated from secondary funerary treatment. MATERIALS AND METHODS: Metric and non-metric methods were used to estimate the age-at-death and sex of the skeletal remains. Perimortem injuries were observed and analyzed with stereomicroscopy and confocal microscopy. RESULTS: Among the minimum of 51 individuals documented, at least six people showed evidence of perimortem trauma. All age groups and both sexes are represented in the skeletal sample, but those with violent injuries are predominantly males. Twenty-six bones had 49 injuries, 48 of which involved sharp force trauma on postcranial elements, and one example of blunt force trauma on a cranium. The wounds were mostly located on the upper extremities and ribs, anterior and posterior. Several antemortem lesions were also documented in the assemblage. DISCUSSION: The perimortem lesions, together with direct dating, suggest that more than one episode of interpersonal violence took place between the Late Chalcolithic and the Early Bronze Age in northeastern Spain. The features of the sharp force trauma indicate that different weapons were used, including sharp metal objects and lithic projectiles. The Roc de les Orenetes assemblage represents a scenario of recurrent lethal confrontation in a high mountain geographic context, representing the evidence of inferred interpersonal violence located at the highest altitude settings in the Pyrenees, at 1836 meters above sea level.

OBJETIVOS: Estudiar nuevas evidencias de violencia interpersonal durante la transición entre el Calcolítico y la Edad del Bronce en los Pirineos Orientales, contextualizarlas en la Europa occidental durante ese periodo, y diferenciar estas marcas del tratamiento funerario secundario. MATERIALES Y MÉTODOS: Se han utilizado métodos métricos y no métricos para estimar la edad de muerte y sexo de los restos esqueléticos. Las heridas perimortem fueron observadas y analizadas con estereomicroscopio y microscopio confocal. RESULTADOS: Entre el mínimo de 51 individuos documentados en el yacimiento, al menos seis individuos mostraron evidencias de traumas perimortem. Todos los grupos de edad y ambos sexos están representados en el enterramiento, pero aquellos con heridas violentas son mayoritariamente masculinos. Veintiséis huesos tenían un total de 49 lesiones, 48 de ellos traumatismos cortantes en elementos postcraneales, y un traumatismo contundente en un cráneo. Las heridas estaban mayoritariamente localizadas en las extremidades superiores y costillas, tanto anterior como posterior. Varias lesiones antemortem fueron también documentadas en el conjunto. DISCUSIÓN: Las lesiones perimortem, junto a las dataciones directas, sugieren que se produjo más de un episodio de violencia interpersonal entre el Calcolítico Final y la Edad del Bronce Antiguo en el noreste de España. Las características de los traumatismos cortantes indican que se utilizaron diferentes armas, incluyendo objetos cortantes de metal y proyectiles líticos. El conjunto de Roc de les Orenetes representa un escenario de confrontaciones letales recurrentes en un contexto geográfico de alta montaña, representando la evidencia de violencia interpersonal localizada a mayor altitud de los Pirineos, a 1836 metros sobre el nivel del mar.

Transrectal ultrasound vector projectile imaging for time-resolved visualization of flow dynamics in the male urethra: A clinical pilot study.

BACKGROUND: Quantitative and comprehensive visualization of urinary flow dynamics in the urethra is crucial for investigating patient-specific mechanisms of lower urinary tract symptoms (LUTS). Although some methods can evaluate the global properties of the urethra, it is critical to assess the local information, such as the location of the responsible lesion and its interactions with urinary flow in relation to LUTS. This approach is vital for enhancing personalized and focal treatments. However, there is a lack of such diagnostic tools that can directly observe how the urethral shape and motion impact urinary flow in the urethra. PURPOSE: This study aimed to develop a novel transrectal ultrasound imaging modality based on the contrast-enhanced urodynamic vector projectile imaging (CE-UroVPI) framework and validate its clinical applicability for visualizing time-resolved flow dynamics in the urethra. METHODS: A new CE-UroVPI system was developed using a research-purpose ultrasound platform and a custom transrectal linear probe, and an imaging protocol for acquiring urodynamic echo data in male patients was designed. Thirty-four male patients with LUTS participated in this study. CE-UroVPI was performed to acquire ultrasound echo signals from the participant's urethra and urinary flow at various voiding phases (initiation, maintenance, and terminal). The ultrasound datasets were processed with custom software to visualize urinary flow dynamics and urethra tissue deformation. RESULTS: The transrectal CE-UroVPI system successfully visualized the time-resolved multidirectional urinary flow dynamics in the prostatic urethra during the initiation, maintenance, and terminal phases of voiding in 17 patients at a frame rate of 1250 fps. The maximum flow speed measured in this study was 2.5 m/s. In addition, when the urethra had an obstruction or an irregular partial deformation, the devised imaging modality visualized complex flow patterns, such as vortices and flow jets around the lesion. CONCLUSIONS: Our study findings demonstrate that the transrectal CE-UroVPI system developed in this study can effectively image fluid-structural interactions in the urethra. This new diagnostic technology has the potential to facilitate quantitative and precise assessments of urethral voiding functions and aid in the improvement of focal and effective treatments for patients with LUTS.

Real-Time Attitude Estimation for Spinning Projectiles by Magnetometer Based on an Adaptive Extended Kalman Filter.

The attitude measurement system based on geomagnetic information offers advantages such as small space requirements, fast response times, excellent resistance to high-overload conditions, and cost-effectiveness. However, during the flight process of a high-mobility guided spinning projectile, calculating attitude based on geomagnetic information often leads to non-unique solutions. To address this challenge, this paper proposes the Adaptive Extended Kalman Filter (AEKF) attitude estimation algorithm, based on geomagnetic vector information. Based on the analysis of the short-term attitude motion characteristics of the projectile, the Kalman state system equation and the nonlinear observation equation are established, along with real-time correction of the yaw angle and adaptive updates of parameters. The effectiveness of the algorithm is verified by simulations and experiments, demonstrating its ability to eliminate the dual solution problem inherent in traditional Single-Epoch algorithms. It notably improves the accuracy of pitch and roll angle estimation while providing precise estimates of attitude angular rates. Furthermore, the algorithm effectively mitigates the impact of magnetic disturbances on attitude determination. The proposed method has many potential applications in attitude measurement and navigation using geomagnetic data.

Simulation and Experimental Verification of Magnetic Field Diffusion at the Launch Load during Electromagnetic Launch.

The unique magnetic field environment during electromagnetic launch imposes higher requirements on the design and protection of the internal electronic system within the launch load. This low-frequency, Tesla-level extreme magnetic field environment is fundamentally distinct from the Earth's geomagnetic field. The excessive change rate of magnetic flux can readily induce voltage within the circuit, thus disrupting the normal operation of intelligent microchips. Existing simulation methods primarily focus on the physical environments of rails and armatures, making it challenging to precisely compute the magnetic field environment at the load's location. In this paper, we propose a computational rail model based on the magneto-mechanical coupling model of a railgun. This model accounts for the dynamic current distribution during the launch process and simulates the magnetic flux density distribution at the load location. To validate the model's accuracy, three-axis magnetic sensors were placed in front of the armature, and the dynamic magnetic field distribution during the launch process was obtained using the projectile-borne-storage testing method. The results indicate that compared to the previous literature methods, the approach proposed in this paper achieves higher accuracy and is closer to experimental results, providing valuable support for the design and optimization of the launch load.

Application of lead isotope signature and likelihood ratio evaluation in a shooting incident investigation.

Bullet projectiles are often found in shooting crime scenes and can help identify the cartridges used in shooting events. The most conclusive way to link a fired projectile to a firearm is by identifying the unique markings of the barrel on the projectile or case. But in circumstances where the investigation of striation marks is impossible, lead isotope ratio signature analysis of projectile fragments can facilitate building the linkage of the suspect, the cartridge used and the victim. This work presents a shooting incident happened in a hunting field, where a hunting guide was shot to death. A tiny lead projectile fragment was collected from the victim's head. Pb isotope ratios measured by laser ablation multicollector inductively coupled plasma mass spectrometry (LA-MC-ICPMS) were used to make comparisons between the fragment and the shots seized from two suspects. Additionally, a reference dataset comprising 50 lead bullet projectiles from various manufacturers was characterized using LA-MC-ICPMS. The evaluation of the comparison was carried out by multivariate likelihood ratio (LR) computations based on the reference dataset. The lead isotope ratio and likelihood ratio evaluation methods helped infer the source of the fragment and were highly supportive in the shooting incident investigation.

Ballistic Behavior of Bioinspired Nacre-like Composites.

In this paper, the ballistic performance of a multilayered composite inspired by the structural characteristics of nacre is numerically investigated using finite element (FE) simulations. Nacre is a natural composite material found in the shells of some marine mollusks, which has remarkable toughness due to its hierarchical layered structure. The bioinspired nacre-like composites investigated here were made of five wavy aluminum alloy 7075-T651 (AA7075) layers composed of ~1.1-mm thick square tablets bonded together with toughened epoxy resin. Two composite configurations with continuous layers (either wavy or flat) were also studied. The ballistic performance of the composite plates was compared to that of a bulk monolithic AA7075 plate. The ballistic impact was simulated in the 300-600 m/s range using two types of spherical projectiles, i.e., rigid and elastoplastic. The results showed that the nacre plate exhibited improved ballistic performance compared to the bulk plate and the plates with continuous layers. The structural design of the nacre plate improved the ballistic performance by producing a more ductile failure and enabling localized energy absorption via the plastic deformation of the tablets and the globalized energy dissipation due to interface debonding and friction. All the plate configurations exhibited a better ballistic performance when impacted by an elastoplastic projectile compared to a rigid one, which is explained by the projectile plastic deformation absorbing some of the impact energy and the enlarged contact area between the projectile and the plates producing more energy absorption by the plates.

Airbag-related penetrating injuries: A case series from a level 1 trauma center.

Background: Airbags have significantly reduced the morbidity and mortality associated with trauma following motor vehicle crashes. However, airbags can also be associated with unusual and complex patterns of injuries which could be fatal in some cases. Methods: We collected data and described a series of six cases of penetrating injuries related to airbag deployment that were treated at the Hamad Trauma Center (HTC) of Hamad Medical Corporation which is the only level 1 trauma center in the country. Results: The penetrating injuries were caused by a metal fragment from the inflator component of the airbag which acted as a projectile and was associated with two fatalities. Four of the victims were involved in head on collisions. Most injuries were directly attributable to the airbag projectile, and they occurred in vehicles that were 9 years or more since manufacture. Conclusion: This case series would help the trauma healthcare providers to better understand the airbag-related injuries which influence the management approach for road traffic injuries associated with penetrating trauma. Also, it would bring attention to injury prevention teams as well as state and industrial authorities to reevaluate safety standards in vehicles. Sharing this information with local authorities who govern product safety standards and recalls is essential to ensure that more safety actions are taken to prevent further airbag deployment injuries.

A High-Functional-Density Integrated Inertial Switch for Super-Quick Initiation and Reliable Self-Destruction of a Small-Caliber Projectile Fuze.

With the aim of achieving the combat technical requirements of super-quick (SQ) initiation and reliable self-destruction (SD) of a small-caliber projectile fuze, this paper describes a high-functional-density integrated (HFDI) inertial switch based on the "ON-OFF" state transition (i.e., almost no terminal ballistic motion). The reliable state switching of the HFDI inertial switch is studied via elastic-plastic mechanics and verified via both simulations and experiments. The theoretical and simulation results indicate that the designed switch can achieve the "OFF-ON" state transition in the internal ballistic system, and the switch can achieve the "ON-OFF" state transition in the simulated terminal ballistic system within 8 µs or complete the "ON-OFF" state transition as the rotary speed sharply decreases. The experimental results based on the anti-target method show the switch achieves the "ON-OFF" state transition on the µs scale, which is consistent with the simulation results. Compared with the switches currently used in small-caliber projectile fuzes, the HFDI inertial switch integrates more functions and reduces the height by about 44%.

Effects of Processing Method and Parameters on the Wall Thickness of Gas-Projectile-Assisted Injection Molding Pipes.

Gas-Projectile-Assisted Injection Molding (G-PAIM) is a new injection molding process derived from the Gas-Assisted Injection Molding (GAIM) process by introducing a projectile to it. In this study, the short-shot method and the overflow method of both the G-PAIM and GAIM processes were experimentally compared and investigated in terms of the wall thickness of the pipes and its uniformity. The results showed that the wall thickness of the G-PAIM molded pipe was thinner and more uniform than that of the GAIM molded pipe, and the wall thickness of the pipe molded by the Gas-Projectile-Assisted Injection Molding Overflow (G-PAIM-O) process was the most uniform. For the G-PAIM-O process, the influence of processing parameters, including melt temperature, gas injection delay time, gas injection pressure, melt injection pressure and mold temperature, on the wall thickness and uniformity of the G-PAIM-O pipes were studied via the single-factor experimental method. It was found that the effects of gas injection delay time and gas injection pressure on the wall thickness of the G-PAIM-O pipes were relatively significant. The wall thickness of the pipes increased with the increase in gas injection delay time and decreased with the increase in gas injection pressure. The melt temperature, melt injection pressure and mold temperature had little effect on the wall thickness of the G-PAIM-O pipes. In general, the wall thickness uniformity of the G-PAIM-O pipes was slightly affected by these processing parameters.

A Projectile Concussive Impact Model Produces Neuroinflammation in Both Mild and Moderate-Severe Traumatic Brain Injury.

Traumatic brain injury (TBI) is a major cause of death and disability and is experienced by nearly 3 million people annually as a result of falls, vehicular accidents, or from being struck by or against an object. While TBIs can range in severity, the majority of injuries are considered to be mild. However, TBI of any severity has the potential to have long-lasting neurological effects, including headaches, cognitive/memory impairments, mood dysfunction, and fatigue as a result of neural damage and neuroinflammation. Here, we modified a projectile concussive impact (PCI) model of TBI to deliver a closed-head impact with variable severity dependent on the material of the ball-bearing projectile. Adult male Sprague Dawley rats were evaluated for neurobehavioral, neuroinflammatory, and neural damage endpoints both acutely and longer-term (up to 72 h) post-TBI following impact with either an aluminum or stainless-steel projectile. Animals that received TBI using the stainless-steel projectile exhibited outcomes strongly correlated to moderate-severe TBI, such as prolonged unconsciousness, impaired neurobehavior, increased risk for hematoma and death, as well as significant neuronal degeneration and neuroinflammation throughout the cortex, hippocampus, thalamus, and cerebellum. In contrast, rats that received TBI with the aluminum projectile exhibited characteristics more congruous with mild TBI, such as a trend for longer periods of unconsciousness in the absence of neurobehavioral deficits, a lack of neurodegeneration, and mild neuroinflammation. Moreover, alignment of cytokine mRNA expression from the cortex of these rats with a computational model of neuron-glia interaction found that the moderate-severe TBI produced by the stainless-steel projectile strongly associated with the neuroinflammatory state, while the mild TBI existed in a state between normal and inflammatory neuron-glia interactions. Thus, these modified PCI protocols are capable of producing TBIs that model the clinical and experimental manifestations associated with both moderate-severe and mild TBI producing relevant models for the evaluation of the potential underlying roles of neuroinflammation and other chronic pathophysiology in the long-term outcomes associated with TBI.

Wandering projectile, a rare cause of acute urinary retention.

BACKGROUND: Urethral obstruction due to retained projectile migrating into the genitourinary system has rarely been reported. The literature describes two main methods of retained projectile removal from the genitourinary system: (1) spontaneous expulsion during voiding and (2) manual extraction due to urethral obstruction causing acute urinary retention. CLINICAL PRESENTATION: We present a case in which a 23-year-old man presented with acute urinary retention four days after suffering a gunshot wound to the right distal posterolateral thigh. A retained projectile eroded through the posterior wall (slightly to the right) of the bulbar urethra at the bulb, migrated through the urethra, and eventually became lodged in the external urethral meatus, causing obstruction and acute urinary retention. Subsequently, the foreign body was removed with manual extraction along with gentle external pressure under sedation and the patient was discharged with a 16 Fr transurethral catheter in situ to be kept for 1 week and removed after a week. CONCLUSION: The absences of signs do not always effectively rule out urethral or bladder injury. Urethral foreign bodies are not commonly encountered when they do the entry is usually the urethral meatus. However, the treating physician must that other mechanisms also exist especially in those with bullet injury to flank, abdomen, pelvis and even the distal thigh like our case.