Freezing pre-treatment improves radio frequency explosion puffing (RFEP) quality by altering the cellular structure of purple sweet potato [Ipomoea batatas (L) Lam.].

Radio frequency explosion puffing (RFEP) is a novel oil-free puffing technique used to produce crispy textured and nutritious puffed snacks. This study aimed to investigate the effects of freezing at different temperatures (-20 °C, -40 °C, -80 °C) for14 h and freezing times (1 and 2 times) on the cellular structure of purple sweet potato and the quality of RFEP chips. The analysis of cell microstructure, conductivity, and rheology revealed that higher freezing temperatures and more freezing times resulted in increased damage to the cellular structure, leading to greater cell membrane permeability and decreased cell wall stiffness. However, excessive damage to cellular structure caused tissue structure to collapse. Compared with the control group (4 °C), the RFEP sample pre-frozen once at -40 °C had a 47.13 % increase in puffing ratio and a 61.93 % increase in crispness, while hardness decreased by 23.44 % (p < 0.05). There was no significant change in anthocyanin retention or color difference. X-ray microtomography demonstrated that the RFEP sample pre-frozen once at -40 °C exhibited a more homogeneous morphology and uniform pore distribution, resulting in the highest overall acceptability. In conclusion, freezing pre-treatment before RFEP can significantly enhance the puffing quality, making this an effective method for preparing oil-free puffing products for fruits and vegetables.

Risk of burns in pressure cooker usage: a comprehensive analysis of explosive injuries.

BACKGROUND: Despite the widespread use of pressure cookers for quick and efficient cooking, literature has insufficiently highlighted the potential dangers resulting from inappropriate handling. This study aims to provide a comprehensive overview of 32 patients who presented with pressure cooker burns, emphasizing the serious risks associated with their misuse. METHODS: Retrospective data were collected from patients admitted to Bagcilar Training and Research Hospital Burn Center between 2017 and 2020 with pressure cooker burns in Türkiye. Data encompassed patient characteristics, burn causes, locations, severities, treatments, and clinical outcomes. RESULTS: The study included 32 patients (29 female/3 male) with a mean age of 42.3 (8-83). Patients were categorized based on burn areas, revealing associated injuries such as ocular (34.3%) and ear injuries (6.25%). The average hospital stay was 10.5 days [2-37]. While five pressure cookers exploded due to product-related issues, 26 explosions resulted from user errors (15.6%/81.2%). Importantly, no mortality was observed among the patients. CONCLUSION: While pressure cookers facilitate rapid food preparation, this study underscores the severe risks arising from product or usage errors. This study emphasizes the need for more effective usage instructions and increased awareness about pressure cookers to prevent burn risks. We anticipate that educational programs focused on safe pressure cooker use could significantly reduce the incidence of serious injuries.

Research Application of Laser-induced Shock Wave for Studying Blast-induced Cochlear Injury.

The ear is the organ most susceptible to explosion overpressure, and cochlear injuries frequently occur after blast exposure. Blast exposure can lead to sensorineural hearing loss (SNHL), which is an irreversible hearing loss that negatively affects the quality of life. Detailed blast-induced cochlear pathologies, such as the loss of hair cells, spiral ganglion neurons, cochlear synapses, and disruption of stereocilia, have been previously documented. However, determining cochlear sensorineural deterioration after a blast injury is challenging because animals exposed to blast overpressure usually experience tympanic membrane perforation (TMP), which causes concurrent conductive hearing loss. To evaluate pure sensorineural cochlear dysfunction, we developed an experimental animal model of blast-induced cochlear injury using a laser-induced shock wave. This method avoids TMP and concomitant systemic injuries and reproduces the functional decline in the SNHL component in an energy-dependent manner after LISW exposure. This animal model could be a platform for elucidating the pathological mechanisms and exploring potential treatments for blast-induced cochlear dysfunction.

Impact of the economic crisis, COVID-19 and the Beirut explosion on ophthalmology training in Lebanon: an observational cohort survey-based study.

OBJECTIVES: The objective of the study is to investigate the effects of the COVID-19 pandemic, the economic crisis and the Beirut explosion on the training and work of ophthalmology residents and faculty in Lebanon. DESIGN: This is an observational cohort survey-based research conducted between January and December 2022. SETTING: The study targeted all ophthalmology residents and core faculty in Lebanon. PARTICIPANTS: A total of 52 participants, including 27 residents and 25 core faculty members, completed the survey. PRIMARY OUTCOME MEASURE: Primary outcomes comprised the subjectively reported effect of the three major external stressors on the training and well-being of ophthalmology trainees and educators in Lebanon. RESULTS: The study found that the majority of ophthalmology residents and core faculty members were significantly affected by the COVID-19 pandemic, Beirut explosion and the economic crisis in Lebanon. Significant percentage reported financial burden, decrease in outpatient and surgical load and educational activities. Furthermore, most participants reported higher levels of stress, anxiety and depression during the time of crises. CONCLUSIONS: This study emphasises the need to support healthcare professionals during times of crisis, as they are on the frontlines and can experience high levels of stress, anxiety and depression. By providing support and resources to healthcare professionals, they can better cope with the challenges they face and continue to provide essential care to their patients.

Modeling and simulation on spontaneous detonation of ammonium nitrate explosive induced by sulfide ores.

In this work, the characteristics of the exothermic reaction between ammonium nitrate and sulfide ores were explored using COMSOL Multiphysics. This reaction can cause an increase in temperature within the blast holes of sulfide mines and can potentially induce premature explosions of the explosives. Initially, simulations were conducted to observe temperature variations in blast holes before and after the loading of explosives. Then, the impact of blast hole diameter and initial temperature on the thermal environment was assessed. Subsequent analysis focused on the fluid field's dynamics, examining flow rate changes and the concentration of signature gases produced by the reaction. Additionally, the influence of blast hole diameter on these parameters was evaluated. The results show that the blast hole temperature is positively related to its diameter and initial temperature. When the diameter of the blast hole is 120 mm and 165 mm, a significant change in flow rate is observed, with a trend of being rapidly increased and then rapidly decreased. The production of NH3 is always found to be greater than that of the other two gases. As for NO and SO2, their production is characterized by an approximate ratio of 1:2. The numerical simulation results can provide important theoretical guidance for the spontaneous detonation of blast hole in sulfide mines.

History and investigation of the chemical odors and explosion in the University Avenue sanitary sewer.

During the summer of 2022, a fire and explosion occurred in a sanitary sewer tunnel adjacent to the University of Minnesota Twin Cities campus, propelling utility maintenance covers several meters into the air and jeopardizing the safety of the public and emergency responders. The investigation into the explosion highlighted the complex variables involved in the response to sanitary sewer events. This case study outlines current approaches and proposes recommendations for agencies to be better prepared to prevent, detect, and respond to sewer-related incidents in the future. Our recommendations include the following: (1) proactive use of remote volatile organic compound (VOC) and lower explosive limit (LEL) monitoring in sanitary sewer tunnels, especially downstream of waste discharge sites; (2) incident responders should have access to instruments that measure oxygen, LEL, VOC concentration, carbon monoxide, and hydrogen sulfide; (3) better characterization of the relationship between sewer pressurization, elevation profiles, and vapor movement; (4) verification processes for oil/water separators used by industrial facilities discharging into the sanitary sewer system; (5) installation of ventilated or anchored pressure relief utility maintenance covers where allowed by code; and (6) building maintenance protocols that include regular drain flushing to keep drain traps filled. These measures are recommended to protect infrastructure and the health and safety of the public and the responders.

Contribution of radioactive particles to the post-explosion exposure of atomic bomb survivors implied from their stable chromosome aberration rates.

Even today when nearly 80 years have passed after the atomic bomb (A-bomb) was dropped, there are still debates about the exact doses received by the A-bomb survivors. While initial airborne kerma radiation (or energy spectrum of emitted radiation) can be measured with sufficient accuracy to assess the radiation dose to A-bomb survivors, it is not easy to accurately assess the neutron dose including appropriate weighting of neutron absorbed dose. Particularly, possible post-explosion exposure due to the radioactive particles generated through neutron activation have been almost neglected so far, mainly because of a large uncertainty associated to the behavior of those particles. However, it has been supposed that contribution of such non-initial radiation exposure from the neutron-induced radioactive particles could be significant, according to the findings that the stable chromosomal aberration rates which indicate average whole-body radiation doses were found to be more than 30% higher for those exposed indoors than for those outdoors even at the same initial dose estimated for the Life Span Study. In this Mini Review article, the authors explain that such apparently controversial observations can be reasonably explained by assuming a higher production rate of neutron-induced radioactive particles in the indoor environment near the hypocenter.

In Silico Investigation of Biomechanical Response of a Human Brain Subjected to Primary Blast.

The brain response to the explosion-induced primary blast waves is actively sought. Over the past decade, reasonable progress has been made in the fundamental understanding of blast traumatic brain injury (bTBI) using head surrogates and animal models. Yet, the current understanding of how blast waves interact with human is in nascent stages, primarily due to the lack of data in human. The biomechanical response in human is critically required to faithfully establish the connection to the aforementioned bTBI models. In this work, the biomechanical cascade of the brain under a primary blast has been elucidated using a detailed, full-body human model. The full-body model allowed us to holistically probe short- (<5 ms) and long-term (200 ms) brain responses. The full-body model has been extensively validated against impact loading in the past. We have further validated the head model against blast loading. We have also incorporated the structural anisotropy of the brain white matter. The blast wave transmission, and linear and rotational motion of the head were dominant pathways for the loading of the brain, and these loading paradigms generated distinct biomechanical fields within the brain. Blast transmission and linear motion of the head governed the volumetric response, whereas the rotational motion of the head governed the deviatoric response. Blast induced head rotation alone produced diffuse injury pattern in white matter fiber tracts. The biomechanical response under blast was comparable to the impact event. These insights will augment laboratory and clinical investigations of bTBI and help devise better blast mitigation strategies.

A systematic review of otologic injuries sustained in civilian terrorist explosions.

PURPOSE: Determine the prevalence of otological symptoms and tympanic membrane perforation, healing rates of tympanic membrane perforation with surgical and conservative management, and hearing function in civilian victims of terrorist explosions. METHODS: A systematic review was conducted with searches on Medline, Embase, EMCare and CINAHL for publications between the 1st January 1945 and 26th May 2023. Studies with quantitative data addressing our aims were included. This review is registered with PROSPERO: CRD42020166768. Among 2611 studies screened, 18 studies comprising prospective and retrospective cohort studies were included. RESULTS: The percentage of eardrums perforated in patients admitted to hospital, under ENT follow up and attending the emergency department is 69.0% (CI 55.5-80.5%), 38.7% (CI 19.0-63.0%, I2 0.715%) and 21.0% (CI 11.9-34.3%, I2 0.718%) respectively. Perforated eardrums heal spontaneously in 62.9% (CI 50.4-73.8%, I2 0.687%) of cases and in 88.8% (CI 75.9-96.3%, I2 0.500%) of cases after surgery. Common symptoms present within one month of bombings are tinnitus 84.7% (CI 70.0-92.9%, I2 0.506%), hearing loss 83.0% (CI 64.5-92.9%, I2 0.505%) and ear fullness 59.7% (CI 13.4-93.4%, I2 0.719). Symptomatic status between one and six months commonly include no symptoms 57.5% (CI 46.0-68.3%), hearing loss 35.4% (CI 21.8-51.8%, I2 0.673%) and tinnitus 15.6% (CI 4.9-40.0%, I2 0.500%). Within one month of bombings, the most common hearing abnormality is sensorineural hearing loss affecting 26.9% (CI 16.9-40.1%, I2 0.689%) of ears 43.5% (CI 33.4-54.2%, I2 0.500) of people. CONCLUSION: Tympanic membrane perforation, subjective hearing loss, tinnitus, ear fullness and sensorineural hearing loss are common sequelae of civilian terrorist explosions.

Fuzzy multi-criteria decision-making framework for controlling methane explosions in coal mines.

The structure of underground coal mines is vulnerable to many mishaps because of the challenging conditions of production and the unique features of the earth. These incidents could cause significant financial and production losses for the mines in addition to worker injury, disability, or death. In coal mines, methane explosions are a frequent threat. Establishing a safe work environment requires managing these problems with an accident control method. The current study used the fuzzy TOPSIS and fuzzy AHP techniques for this aim. The framework was used to tackle the four-alternative problem of underground coal mine explosion control method selection. To identify potential risks of a methane explosion, a data gathering survey was conducted as part of the suggested hybrid methodology. The fuzzy AHP was used to compute the fuzzy weights of the hazards. "Improper ventilation system" is ranked highest out of the 34 sub-risk factors. The fuzzy TOPSIS was then utilized to rank the explosion control methods using the weights. To assess the viability of the study's conclusions, a sensitivity analysis was carried out. The findings indicate that "improving safety technology" and "financial investments" are the best ways to reduce such events. The results additionally indicate that the fuzzy TOPSIS approach in combination with the fuzzy AHP provides a helpful framework for dynamically assessing mine methane explosion accidents.

Impact of the 4th of August Beirut explosion mass casualty incident on a university hospital microbial Flora.

BACKGROUND: Following the Beirut explosion, our university hospital received at least 350 casualties. Subsequently, infection control standard practices were compromised. Concerns for Multi-Drug Resistant Organisms (MDROs) infections in injured patients and a resulting hospital outbreak were raised. The objectives of the study were to compare the rate of hospital growing MDROs 6 months before and 6 months after the Beirut explosion, to identify emerging microorganisms and to evaluate the change in surgical infection prevention practices. METHODS: This is a retrospective chart review of patients with hospital acquired infections (HAI) admitted to the hospital before and after the Beirut explosion. The study was conducted between February 4, 2020 and January 4, 2021. Excluded patients were those transferred from other hospitals and those with community acquired infections. The primary outcome was to identify the rate of growing MDROs post explosion. The secondary outcomes were identifying antibiotics used for surgical prophylaxis in patients requiring surgeries and patients diagnosed with a HAI. Therefore, patients were divided in three groups. Control group included patients admitted with explosion-related injuries on that same day. Patients admitted and between February 4 and August 4 and diagnosed with HAI were compared to those admitted post August 4 with explosion-related HAI and to patients diagnosed with non-explosion-related HAI between August 4 and January 4, 2021. An estimated rate of 18-22% MDRO was needed to achieve a statistical significance with 80% power and 0.05 α. Pearson Chi square test was used to analyze the primary outcome. RESULTS: A total of 82 patients with 150 cultures were included in this study. Data showed an increase in the rate of MDRO after the explosion with 37.1% of the cultures taken before the explosion and 53.1% after the explosion (p = 0.05). When comparing the types of HAI in both groups, culture sites were significantly different between pre- and post-explosion patients (p = 0.013). However, both groups had similar types of microbes (p = 0.996) with an increase in candida related infections. CONCLUSION: These findings confirmed that the Beirut explosion impact on antimicrobial resistance was similar to combat zone incidence, where an increase in MDROs rate such as Escherichia coli (E.Coli) and Stenotrophomonas maltophilia, in addition to the increase in candida related infections.

Analysis of characteristics and causes of gas explosion accidents: a historical review of coal mine accidents in China.

Objectives This study aimed to provide greater insight into the characteristics of severe and extraordinarily severe gas explosion accidents (SESGEAs). Methods. The study analyzed the accident characteristics and causes of SESGEAs. As an example, we conducted a specialized case analysis using the 24Model (fourth edition) on the recent Baoma coal mine gas explosion. Results. SESGEA data are characterized by greater volatility, with significant differences in the geographical distribution, temporal distribution and attributed characteristics of the accidents. From the accident analysis: chaotic ventilation management was the most serious accident cause of SESGEAs; unsafe acts related to ventilation operations accounted for 18.51% of all unsafe acts; coal miners lack professional safety knowledge and have a serious fluke mentality in mining work; enterprises have insufficient enforcement of safety procedure documents, and lack of attention to the allocation of underground human resources and safety training systems; and the importance of safety, the role of the safety department and satisfaction with safety facilities have become the most serious missing items of safety culture. Conclusion. This study can provide important data support and management basis to assist mine operators in developing more targeted accident prevention strategies.

Curcumin alleviates traumatic brain injury induced by gas explosion through modulating gut microbiota and suppressing the LPS/TLR4/MyD88/NF-κB pathway.

Gas explosions (GE) are a prevalent and widespread cause of traumatic brain injury (TBI) in coal miners. However, the impact and mechanism of curcumin on GE-induced TBI in rats remain unclear. In this study, we simulated GE-induced TBI in rats and administered curcumin orally at a dose of 100 mg/kg every other day for 7 days to modulate the gut microbiota in TBI rats. We employed 16S rRNA sequencing and LC-MS/MS metabolomic analysis to investigate changes in the intestinal flora and its metabolic profile. Additionally, we utilized ELISA, protein assays, and immunohistochemistry to assess neuroinflammatory signaling molecules for validation. In a rat TBI model, GE resulted in weight loss, pathological abnormalities, and cortical hemorrhage. Treatment with curcumin significantly mitigated histological abnormalities and microscopic mitochondrial structural changes in brain tissue. Furthermore, curcumin treatment markedly ameliorated GE-induced brain dysfunction by reducing the levels of several neuroinflammatory signaling molecules, including neuron-specific enolase, interleukin (IL)-1ß, IL-6, and cryptothermic protein 3. Notably, curcumin reshaped the gut microbiome by enhancing evenness, richness, and composition. Prevotella_9, Alloprevotella, Bacilli, Lactobacillales, Proteobacteria, and Gammaproteobacteria were identified as prominent members of the gut microbiota, increasing the linear discriminant analysis scores and specifically enhancing the abundance of bacteria involved in the nuclear factor (NF)-κB signaling pathway, such as Lachnospiraceae and Roseburia. Additionally, there were substantial alterations in serum metabolites associated with metabolic NF-κB signaling pathways in the model group. Curcumin administration reduced serum lipopolysaccharide levels and downregulated downstream Toll-like receptor (TLR)4/myeloid differentiation primary response 88 (MyD88)/NF-κB signaling. Furthermore, curcumin alleviated GE-induced TBI in rats by modulating the gut microbiota and its metabolites. Based on these protective effects, curcumin may exert its influence on the gut microbiota and the TLR4/MyD88/NF-κB signaling pathways to ameliorate GE-induced TBI.

Important role of turbulence on the distribution of particle radioactivity in the nuclear explosions.

The distribution of particle radioactivity is one of the most important source items of radioactive fallout prediction model for nuclear explosion. For radioactive particles with the diameter larger than 0.5 µm, the influence of turbulent coagulation cannot be ignored. However, few scholars have considered the role of turbulence in the study of the distribution of particle radioactivity. The General Dynamic Equation (GDE), which is solved using the Multi-Monte Carlo method, is used in this study to establish a new model of the distribution of particle radioactivity that takes the impact of turbulent coagulation into account. The results present that the surface and volume distributions of particle radioactivity are closer to those of the Defense Land Fallout Interpretative Code (DELFIC) model, and the relative error of the surface (volume) distribution reduces from 1.243 (0.687) to 0.945 (0.284) when compared to the previous model that simply takes Brownian coagulation into account. The geometric median diameter of total particle radioactivity increases as the solidification temperature increases and as the particle size range increases when considering the influence of various geological conditions. When considering the effects of turbulent coagulation, the differences in the particle radioactivity produced under different geological conditions are smaller than those only considering the Brownian coagulation. This study highlights the importance of turbulent coagulation on the distribution of particle radioactivity in the nuclear explosions.

Blunt force trauma and blast injuries to head and chest caused by a potent pyrotechnic device: a case report.

In times of peace and except for terrorist attacks, fatalities by explosions are rare. Fireworks have deadly potential, especially self-made or illegally acquired devices. The use of professional pyrotechnics by untrained persons poses a life-threatening hazard. We present a case of devastating blunt force and blast injuries to the head and chest of a young man. After ignition of a display shell (syn. a real shell or mortar shell) without the use of a launching pipe, the device hit the man's face, nearly simultaneously followed by the explosion of the burst charge. The autopsy revealed injuries to the face and forehead as well as extensive tissue structure damage and a massive contusion with a bloody edema of the lungs. Autopsy results are supplemented with CT imaging and 3D reconstruction of the fractured mid face, as well as histological and toxicological examinations. This case of a misused display shell demonstrates both its devastating destructive potential and the corresponding and rarely observed injury pattern.

Lower Extremity Injury Risk Curve Development for a Human Body Model in the Underbody Blast Environment.

Computational human body models (HBMs) provide the ability to explore numerous candidate injury metrics ranging from local strain based criteria to global combined criteria such as the Tibia Index. Despite these efforts, there have been relatively few studies that focus on determining predicted injury risk from HBMs based on observed postmortem human subjects (PMHS) injury data. Additionally, HBMs provide an opportunity to construct risk curves using measures that are difficult or impossible to obtain experimentally. The Global Human Body Models Consortium (GHBMC) M50-O v 6.0 lower extremity was simulated in 181 different loading conditions based on previous PMHS tests in the underbody blast (UBB) environment and 43 different biomechanical metrics were output. The Brier Metric Score were used to determine the most appropriate metric for injury risk curve development. Using survival analysis, three different injury risk curves (IRC) were developed: "any injury," "calcaneus injury," and "tibia injury." For each injury risk curve, the top three metrics selected using the Brier Metric Score were tested for significant covariates including boot use and posture. The best performing metric for the "any injury," "calcaneus injury" and "tibia injury" cases were calcaneus strain, calcaneus force, and lower tibia force, respectively. For the six different injury risk curves where covariates were considered, the presence of the boot was found to be a significant covariate reducing injury risk in five out of six cases. Posture was significant for only one curve. The injury risk curves developed from this study can serve as a baseline for model injury prediction, personal protective equipment (PPE) evaluation, and can aid in larger scale testing and experimental protocols.

Blast-Induced Central Auditory Neurodegeneration Affects Tinnitus Development Regardless of Peripheral Cochlear Damage.

Blast exposure causes serious complications, the most common of which are ear-related symptoms such as hearing loss and tinnitus. The blast shock waves can cause neurodegeneration of the auditory pathway in the brainstem, as well as the cochlea, which is the primary receptor for hearing, leading to blast-induced tinnitus. However, it is still unclear which lesion is more dominant in triggering tinnitus, the peripheral cochlea or the brainstem lesion owing to the complex pathophysiology and the difficulty in objectively measuring tinnitus. Recently, gap detection tests have been developed and are potentially well-suited for determining the presence of tinnitus. In this study, we investigated whether the peripheral cochlea or the central nervous system has a dominant effect on the generation of tinnitus using a blast-exposed mouse model with or without earplugs, which prevent cochlear damage from a blast transmitted via the external auditory canal. The results showed that the earplug (+) group, in which the cochlea was neither physiologically nor histologically damaged, showed a similar extent of tinnitus behavior in a gap prepulse inhibition of acoustic startle reflex test as the earplug (-) group, in which the explosion caused a cochlear synaptic loss in the inner hair cells and demyelination of auditory neurons. In contrast, both excitatory synapses labeled with VGLUT-1 and inhibitory synapses labeled with GAD65 were reduced in the ventral cochlear nucleus, and demyelination in the medial nucleus of the trapezoid body was observed in both groups. These disruptions significantly correlated with the presence of tinnitus behavior regardless of cochlear damage. These results indicate that the lesion in the brainstem could be dominant to the cochlear lesion in the development of tinnitus following blast exposure.

Religious coping and levels of posttraumatic stress disorder symptomatology after the Beirut explosion.

OBJECTIVE: Religious coping has implications for the development of psychopathology in the aftermath of traumatic events. This study explored the relationship between religious coping (positive and negative) and posttraumatic stress disorder (PTSD) symptomology among survivors of a large industrial explosion that devastated parts of Beirut in August of 2020. METHOD: Three months after the disaster, 996 residents of Beirut and Lebanon completed validated measures of religious coping (RCOPE) and PTSD symptomatology (Impact of Events Scale-Revised) in either English or Arabic. The majority of participants were young adults aged between 18 and 25 years. RESULTS: Results indicated that higher levels of negative religious coping were a significant predictor of higher levels of PTSD symptomatology and were associated with a two-fold risk of meeting the criteria for probable PTSD. Other significant predictors included female gender, being a resident of Beirut at the time of the explosion, having personally sustained an injury, or knowing a person injured in the explosion. Effects sizes ranged from .34 to .68. CONCLUSIONS: Higher scores on measures of negative religious coping were associated with higher levels of PTSD symptomatology. However, negative religious coping may be better construed as a set of religious-based appraisals of event causality and may represent a form of peritraumatic appraisal in the wake of traumatic events. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Evaluating Pelvis Response During Simulated Underbody Blast Loading.

In recent conflicts, blast injury from landmines and improvised explosive devices (IEDs) has been the main mechanism of wounding and death. When a landmine or IED detonates under a vehicle (an under-body blast), the seat acceleration rapidly transmits a high load to the pelvis of the occupants, resulting in torso and pelvic injury. Pelvic fractures have high mortality rates, yet their injury mechanism has been poorly researched. Three (3) fresh-frozen male pelvic specimens were tested under axial impact loading. The pelvis was impacted mounted upside down by dropping a 12 kg mass at target impact velocities ranging from 1 to 8.6 m/s with time to peak velocity ranging from 3.8 to 5.8 ms. Resulting fractures were broadly categorized as involving a bilateral pubis rami fracture, a bilateral ischium fracture, and sacroiliac joint disruption. The study provides insights into the type and severity of pelvic injury that may occur over a range of under-body blast (UBB)-relevant loading profiles.

A comparison of fracture response in female and male lumbar spine in simulated under body blast component tests.

Underbody blasts (UBB) from mines and improvised explosive devices in military combat can cause debilitating spine injuries to vehicle mounted soldiers. Due to the exclusion of females in combat roles in prior US Department of Defense policy, UBB exposure and injury have predominantly affected male soldiers. Recent policy changes have opened many combat roles to women serving in the US Military (Carter, 2015) and have increased the need to understand the injury potential for female Warfighters. The goal of this study was to investigate the fracture response of adult female lumbar spines compared to adult male spines in UBB relevant loading to identify potential differences in either fracture mechanism or force. Results are presented for 15 simulated UBB spine compression tests using three small female (SF), five large female (LF), and seven mid-sized male (MM) post-mortem human subjects (PMHS). These PMHS groups align to 5th- and 75th-percentile female and 50th-percentile males, based on height and weight from the 2012 Anthropometric Survey of U.S. Army Personnel (Gordon et al., 2014). Both small females and large females (similar in size to the males) were included to assess the role of size and/or sex in the response. Tests were conducted at Virginia Tech on a cam-driven linear compression rig, which included a 6-axis load cell and ram accelerometer to evaluate the fracture. Fracture was visualized through high-speed x-ray video. All female and male spines exhibited similar fracture initiation at the end plates and progression through the vertebral body. The resulting severe compression and burst fractures were representative of reported theatre injuries (Freedman et al., 2014). Mean axial fracture forces were -4182 ± 940 N (SF), -6225 ± 1180 N (LF), -5459 ± 1472 N (All Females) and -7993 ± 2445 N (MM). The SF group was found to have statistically significant differences in mean fracture force compared to both LF and MM groups, while no significant difference was found between LF and MM groups, although the mean force at initial fracture was lower for the LF group. The All-Females group Fz mean was significantly different from the MM group. These data suggest that the significant difference in weight between the SF and LF groups, did have an influence on the Fz outcome, when controlling for sex. Conversely, controlling for size in the LF and MM comparison, sex did influence the mean Fz, but was not statistically significant. Groups with combined sex and size differences, however, did show significant differences in mean Fz. Further study is warranted to understand whether sex or size has a larger effect on fracture force. Mean ram displacement (spine compression) values at fracture initiation were -6.0 ± 5.3 mm (SF), -4.4 ± 0.8 mm (LF), -5.0 ± 3.0 mm (All Females), -6.2 ± 4.5 mm (MM). Spine compression did not seem to be largely influenced by either sex or size, and none of the groups was found to have significant differences in mean displacement values.