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In land geophysical exploration an impulsive or vibratory source, operating at the earth’s surface, is used to generate the seismic signal during the field acquisition. Comparisons of the manufacturer’s output specifications will often be a factor in selecting a seismic source for ‘good S/N’ (signal to noise ratio) in a particular survey area. For impulsive sources, such as dynamite, weight drop, and accelerated weight drop (AWD), the source specifications are given in energy units (Joules, foot-pounds) whereas vibroseis sources are rated in force units (Newtons, pounds-force). For either type of source, the manufacturer’s specifications are the output ‘power’ of the source mechanism and do not take into account any inefficiencies/losses in energy in the source mechanism or the interacting earth volume when generating the seismic signal. In this paper, I examine some of the factors that determine the transfer of energy from the source mechanism to the seismic signal and show, for AWD sources, the energy transfer during the impulse can be greatly improved by optimization of the source parameters. For vibrators, the energy transfer to the ground may be a better indicator of the propagating wave than the current WSGF estimates.

Concussions and mild traumatic brain injury (m-TBI) have been identified as a consequential public health concern because of their potential to cause considerable impairments in physical, cognitive, behavioral, and social functions. Given their prominent structural and functional roles in the brain, n-3 polyunsaturated fatty acids (PUFA) have been identified as a potentially viable prophylactic agent that may ameliorate the deleterious effects of m-TBI on brain function. The purpose of the present pilot study was to investigate the effect of n-3 PUFA on neurologic function using a weight drop injury (WDI) model. Fat-1 mice, capable of synthesizing n-3 PUFA endogenously from n-6 PUFA, and their wild-type (WT) counterparts, were subjected to a mild low-impact WDI on the closed cranium, and recovery was evaluated using the neurological severity score (NSS) to assess the motor and neurobehavioral outcomes. In comparison to the WT mice, the fat-1 mice had a significantly (p ≤ 0.05) lower NSS at all time points post-WDI, and significantly greater neurological restoration measured as the time to first movement. Overall, these findings demonstrate the protective effect of n-3 PUFA against mild brain injury.

BACKGROUND Modafinil has been proven to exert anti-inflammatory, anti-oxidative and neuroprotective effects on numerous neurological disorders. However, its effects after traumatic brain injury (TBI) has not been yet explore. This study aimed to explore if Modafinil can attenuate the neuroinflammatory phase of TBI and clarify the possible underlying mechanisms. METHODS A weight drop model was used to induce experimental TBI on 30 Wistar albino rats. The treatment group received Modafinil on the day of the trauma and the following 5 days. Garcia Test was used to assess for neurological status and histopathological examination along with biochemical analysis of NSE, S-100B, CASP3, and TBARS levels were performed. RESULTS Rats treated with Modafinil after the trauma had a statistically significant higher Garcia test score (p

The steam evaporator may shut holder where water or different liquids are warmed under tension and the steam discharged by the kettle is utilized for different warming applications. The fundamental contemplations in planning a kettle for a specific application are structure and warm investigation, structure for creation, physical measurements and cost. In this postulation, the progression of steam in the steam kettle (without diverters and with redirectors) is displayed utilizing the CREO parametric plan programming. The postulation will concentrate on warm and CFD examination with various info speeds (20, 30, 40 and 50 m/s). In this theory, CFD investigation decides the warmth move coefficient, the warmth move rate, the figure stream rate and the weight drop. Warm inspection to choose the temperature movement, the warmth stream for the two models of steam kettle without diverters and steam evaporator with redirectors. Discover which model is the best. 3D displaying in the parametric CREO programming and dissects acted in ANSYS.

This study describes a methodology that allows evaluating the behavior of a glass fibre reinforced polymer (GFRP) laminate impacted by a vertical weight drop, analyzing the damage that occurred inside. The purpose of the designers was, by means of characterization tests of the curing processes, evaluation of the cohesion of a particular laminate, application of vertical tests by weight drops and with the use of the readings of an accelerometer in a single direction, know the trend of how intralaminar breaks in the matrix and interlaminar breaks between layers occur. It is proposed to establish the behavior of the laminate before the tests by analyzing curing times, for after the tests by observations with penetrating fluorescent inks. This allows researchers to know the response of the laminate to the loads imposed on the applied structure. For the tests, prepreg material cured outside the autoclave in an oven was used and qualitative quantification of the damage by observing sections of the tested material infiltrated with penetrating fluorescent ink exposed to ultraviolet light.

The article discusses the efficiency of convolutional neural networks in solving the problem of face recognition of tennis players. The characteristics of training and accuracy on a test set for networks of various architectures are compared. Application of weight drop out methods and data augmentation to eliminate the effect of retraining is also considered. Finally, the transfer learning from other known networks is used. It is shown how, for initial data, it is possible to increase recognition accuracy by 25% compared to a typical convolutional neural network.

For evaluating the impact strength of dental materials, the Izod test or Charpy test has been used, but specimen preparation for these tests is difficult due to the adjustment of a notch on them. By contrast, a weight-drop impact test does not require notched specimens. Therefore, it might be possible to measure the impact strength more accurately than conventional methods. This study aimed to establish appropriate conditions for applying the weight-drop impact test on small specimens of acrylic resin. To determine the most reliable impact fracture energy of acrylic resins, different diameters and thicknesses of PMMA resin specimens, diameters and weights of the striker, and diameters of the supporting jig were compared. For all specimen thicknesses, when the striker diameter was 6&ndash, 10 mm, the impact fracture energy was constant when the inner diameter of the specimen-supporting jig was 8&ndash, 10 mm. In addition, the measured E50% value was mostly equal to the median value of the impact fracture energy. Thus, for the weight-drop impact test, this method was effective for material testing of small specimens, by clearly specifying the test conditions, such as the thickness of disc-shaped specimens, the diameter of the striker, and the inner diameter of the specimen-supporting jig.

Heat is the term distinct as the amount of energy transferred by the virtue of the temperature difference. The heat flows from the region of maximum temperature to minimum temperature by the different methods of heat conveyed. This paper focuses on the study of heat transfer in the heat exchanger which is a device used for transfer of thermal energy and consists of two or additional fluids or between surface of fluid and solid to solid particulates and a fluid at different temperature, thermal constant with and without outside heat and work communications. The parameters of heat transfer are analyzed in different types of heat exchangers. This examination explores the warmth move and the weight drop of cone helically curled cylinder heat exchanger utilizing Al2O3/water nanofluids. The Al2O3/water nanofluids at 0.2, 0.4, and 0.6% molecule volume fixations were set up with the expansion of surfactant by utilizing the two advance strategies. The experimental study of heat transfer in various heat exchangers is discussed.

Whilst detrimental effects of repeated sub-concussive impacts on neurophysiological and behavioral function are increasingly reported, the underlying mechanisms are largely unknown. Here, we report that repeated sub-concussion with a light weight drop (25 g) in wild-type PVG rats for 2 weeks does not induce detectable neuromotor dysfunction assessed by beamwalk and rotarod tests. However, after 12 weeks of repeated sub-concussion, the rats exhibited moderate neuromotor dysfunction. This is the first study to demonstrate development of neuromotor dysfunction following multiple long-term sub-concussive impacts in rats. The outcomes may offer significant opportunity for future studies to understand the mechanisms of sub-concussion-induced neuropsychological changes.

Traumatic brain injury (TBI) is a global scenario with high mortality and disability, which does not have an effectual and approved therapy till now. Bladder dysfunction is a major symptom after TBI, and this study deals with the alleviation of bladder function in TBI rats, with the aid of deep brain stimulations (DBS). TBI was induced by weight drop model (WDM) and standardized with the experimental subjects with variable heights for weight dropping. The rats survived after TBI were considered for bladder dysfunction observations. DBS with variable stimulation parameters like cystometric analysis and MRI studies were also performed. After experimental studies, TBI 2-m-height crash was determined as suitable parameter due to minimal mortality rate and significant reduction in the voiding efficiency from 67 to 28%, whereas DBS significantly reversed the value of voiding efficiency to 65–84%. MRI studies revealed the severity of TBI impact and DBS localization. The results showed profound therapeutic effect of PnO-DBS on voiding functions and bladder control on TBI rats.

Objective To evaluate the effects of electric cortical stimulation (ECS) and transcranial direct current stimulation (tDCS) on motor and cognitive function recovery and brain plasticity in focal traumatic brain injury (TBI) of rats model. Methods Forty rats were pre-trained to perform a single pellet reaching task (SPRT), rotarod test (RRT), and Y-maze test for 14 days, then a focal TBI was induced by a weight drop model on the motor cortex. All rats were randomly assigned to one of the three groups: anodal ECS (50 Hz and 194 μs) (ECS group), tDCS (0.1 mA, 50 Hz and 200 μs) (tDCS group), and no stimulation as a control group. Four-week stimulation, including rehabilitation, was started 3 days after the operation. SPRT, RRT, and Y-maze were measured from day 1 to day 28 after the TBI was induced. Histopathological and immunohistochemistry staining evaluations were performed at 4 weeks. Results SPRT was improved from day 7 to day 26 in ECS, and from day 8 to day 26 in tDCS compared to the control group (p

Background Models of spinal cord injury (SCI) caused by weight-drop devices to cause contusion have been used extensively, and transient behavioral deficits after thoracic injury have been demonstrated. The severity of the injury caused by the device should be mild enough to allow recovery. Objective To determine whether our adapted weight-drop device with a small tip can effectively induce mild hemicontusion at the level of the fifth cervical vertebra. Methods We divided 15 adult male Sprague Dawley rats into groups of 5 for the following treatments: sham (SH, laminectomy only), mild (MSCI) or severe SCI (SSCI). Behavioral tests and histopathology were used before (day 1) and after the treatment on days 3, 7, 14, 21, 28, and 35 to assess the injury. Results Rats with SSCI showed a significant somatosensory deficit on days 3 and 7 compared with rats in the SH group, recovering by day 14. In a horizontal-ladder test of skilled locomotion, rats with SSCI showed a significant increase in error scores and percentage of total rungs used, and a decrease in the percentage of correct paw placement compared with rats in the SH group. There was greater recovery to normal paw placement by rats with MSCI than by rats with SSCI. These behavioral deficits were consistent with histopathology using hematoxylin and eosin counterstained Luxol fast blue, indicating the degree of injury and lesion area. Conclusions Mild hemicontusion caused by the adapted device can be used to evaluate SCI and provides a model with which to test the efficacy of translational therapies for SCI.

The growth of toddlers can be known if each month weighed. Weighing results are recorded in KMS, and between the KMS weight point of last month's weighing results and the month's weighing results are attributed to a line. Based on the results of preliminary study on 7 mothers found out the results of two primary school graduates, 2 mothers of junior high school, and 3 mothers of high school graduates. Then the mother was asked about the nutrition of toddlers aged 1-5 years and 4 mothers know but do not understand the whole while 3 mothers do not know at all about nutrition balita1-5 years, from 7 mother toddler 3 balitanya experience weight gain while 4 balita weight drop . This study aims to determine the relationship of mother's knowledge about the nutrition of children under five with weight growth of children under five. The design of this research is analytical method with Cross Sectional approach. With the total population of 61 respondents, the sample of the research is 31 respondents using sampling technique that is accidental sampling. Data collection was obtained by questionnaire and view of KMS. Data were analyzed using spearman rank. The result of the research shows that from 31 respondents, most of BB did not increase with 19 respondents (61,3%) and almost half of them were less knowledge with 14 respondents (45,2%). Statistical test using spearman rankdidapatkan ρ = 0.000 with significance level ρ

Object: The pathologies resulting from traumatic brain injury (TBI) have been thoroughly studied, but rarely have the effects of bleeding and coagulation in the early stage of TBI been considered. In this study, we investigated the effects of topical Surgiflo® application on brain injury in experimental TBI mice using S100β, MAP-2 and mNSS scores.Methods: TBI was induced by modified weight drop injury in male C57BL/6 mice. The mice were then randomly divided into (i) the sham group, (ii) TBI mice applied with saline (vehicle), and (iii) TBI mice applied with Surgiflo® in the same volume. Modified neurological severity scores (mNSS) were measured on days 0 (before surgery), 1, 3, 7, and 28 to evaluate neurologic functional deficits. At day 28, the mice were sacrificed, and the forebrains were sliced. The effects of Surgiflo® on microtubule-associated protein 2 and serum S100β protein were examined by immunohistochemistry and electro-chemiluminescence immunoassay.Results: Serum S100β protein levels ...

In order to guarantee the technical equipment of the weighing precipitation sensor and make its observation data more accurate, this paper takes the DSC3 load-type weighing precipitation sensor produced by Tianjin Huayun Tianyi Special Meteorological Detection Technology Co., Ltd. as an example, and according to its structure and working principle, puts forward to use the standard capacity, ball precision electronic analysis balance to control the flow and simulate different rain intensity to make the symmetrical weight drop, successfully avoiding the error caused by manual water injection. In this paper, discusses the field calibration method of the weighing precipitation sensor from the aspects of the selection of calibration equipment, the control and adjustment of precipitation intensity, and the problems that should be paid attention to in the field calibration. This paper also discusses the calibration of different water levels in the collection container. The results show that the calibration of the weighing type precipitation sensor is independent of the water level of the collection container, can be calibrated at any water level, and the error of different precipitation intensity is stable. The error after calibration can be used as the system error, which is more accurate and reliable than the tipping bucket type precipitation sensor.

OBJECTIVE: To evaluate the effects of interleukin-6 (IL-6) and erythropoietin (EPO) in experimental acute spinal cord injury (SCI) in rats. METHODS: Using standardized equipment, namely, a New York University (NYU) Impactor, a SCI was produced in 50 Wistar rats using a 10-g weight drop from a 12.5-mm height. The rats were divided into the following 5 groups of 10 animals each: ‘‘Group EPO’’, treated with erythropoietin only; ‘‘Group EPO + IL-6’’, treated with both substances; ‘‘Group IL-6’’, receiving IL-6 administration only; ‘‘Group Placebo’’, receiving a placebo solution; and ‘‘Group Sham’’, submitted to an incomplete procedure (only laminectomy, without SCI). All drugs and the placebo solution were administered intraperitoneally for three weeks. The animals were followed up for 42 days. Functional motor recovery was monitored by the Basso, Beattie, and Bresnahan (BBB) scale on days 2, 7, 14, 21, 28, 35 and 42. Motor-evoked potential tests were performed on the 42nd day. Histological analysis was performed after euthanasia. RESULTS: The group receiving EPO exhibited superior functional motor results on the BBB scale. IL-6 administration alone was not superior to the placebo treatment, and the IL-6 combination with EPO yielded worse results than did EPO alone. CONCLUSIONS: Using EPO after acute SCI in rats yielded benefits in functional recovery. The combination of EPO and IL-6 showed benefits, but with inferior results compared to those of isolated EPO; moreover, isolated use of IL-6 resulted in no benefit.

Neurological dysfunctions are the most impactful and persistent consequences of traumatic brain injury (TBI). Indeed, previous reports suggest that an association between TBI and chronic pain syndromes, as well anxio-depressive behaviors, tends to be more common in patients with mild forms of TBI. At present, no effective treatment options are available for these symptoms. In the present study, we used a weight drop mild TBI mouse model to investigate the effect of a commercially available 10% Cannabidiol (CBD) oil on both the sensorial and neuropsychiatric dysfunctions associated with mild TBI through behavioral and biomolecular approaches. TBI mice developed chronic pain associated with anxious and aggressive behavior, followed by a late depressive-like behavior and impaired social interaction. Such behaviors were related with specific changes in neurotransmitters release at cortical levels. CBD oral treatment restored the behavioral alterations and partially normalized the cortical biochemical changes. In conclusion, our data show some of the brain modifications probably responsible for the behavioral phenotype associated with TBI and suggest the CBD as a pharmacological tool to improve neurological dysfunctions caused by the trauma.

To determine if chronic changes in mitochondrial function occur following a mild traumatic brain injury in young rats.Closed-head, weight drop model was used to cause mTBI by applying rotational forces to the brain without surgery. Behavioral battery was used to assess multiple dimensions of impairment across time. Analysis of brain tissue carried out at three-weeks post-injury represents a chronic time point to complement previous work examining acute time points.Twenty-three male and 22 female rats one month of age were divided equally into sham and mTBI groups with the latter undergoing the weight drop. Multiple behavioral tests in combination with energetic (oxygen consumption), molecular (immunoblotting), and imaging (electron microscopy) characterization of brain mitochondria were performed.Mitochondria isolated from sham juvenile female rats had higher basal oxygen consumption compared to juvenile male rats (514.875 ± 171.091 pmol/min vs. 267 ± 73.906 pmol/min, p 0.0001). Chronic sex-dependent differences were observed in females after mTBI in basal (514.875 ± 171.091 pmol/min vs. 600.688 ± 124.422 pmol/min, p = 0.0264) and maximal oxygen consumption (298.938 ± 119.964 pmol/min vs. 403.281 ± 112.922 pmol/min, p = 0.0001) and proton leak (59.46 ± 7.807 vs. 84.32 ± 5.80 pmol/min, p = 0.0001).The juvenile rat brain displays sex differences in mitochondrial function at (1) baseline and (2) in long-term outcomes after mTBI. These results offer new insight into a potential mechanism for persistent, individualized impairments following pediatric mTBI.

The Chalk Group forms important hydrocarbon reservoirs offshore and water aquifers onshore Denmark. Within a day of fieldwork, a 450 m long reflection seismic profile was acquired onshore in an area in southeast Denmark, where the Chalk Group extends almost to the surface and is approximately 900 m thick. The main objective of the study was to image the complete Chalk Group in high resolution and to study the origin of reflectivity within the different chalk units. A 45 kg accelerated weight-drop source, in combination with dense receiver spacing using microelectromechanical sensors mounted on a streamer and 48 planted geophones, was used for data acquisition. The profile runs subparallel to the cliffs of Stevns, and the recorded signal reaches the base of the Chalk Group at approximately 600 ms. The fully cored 443 m-deep Stevns-1 borehole, which is located at the recorded seismic line, provides excellent control on lithologic and facies changes. Comparison with the borehole data demonstrates that our seismic data set provides a high-resolution image of the internal layering of the Chalk Group. We find that the internal reflection coefficients of the Chalk Group are, in general, small based on wireline-log data. However, the reflected amplitudes are just big enough to be recorded with the receiver setup used, even from the pure chalk beds of the Chalk Group. The reflectivity seen on the high-resolution seismic profile is influenced by occurrences of clay-enriched chalk layers. Flint bands consisting of numerous flint nodules are a characteristic of the uppermost part of the Chalk Group at Stevns. The flint nodules appear to produce significant scattering of the seismic signals, and flint-rich layers appear with diffuse internal reflectivity characteristics. Outcrop-scale mound structures in Danian and Upper Cretaceous outcrops are for the first time seismically resolved.

Experimental contusion spinal cord injury (SCI) is the most frequently used in vivo model to provide insight into the mechanisms of secondary injury. Many criteria have been utilized to control the severity of SCI, including the height of the weight drop, the magnitude of the force striking the spinal cord, and the degree of spinal cord tissue displacement. The tissue displacement method is the most reliable technique of producing experimental SCI after the target spine has been stabilized. We have described the creation of a contusion SCI model using the LISA that is versatile and may be adapted for use in mice, rats, and monkeys with minor adjustments in the mechanical settings. Reproducible and reliable contusion SCI may be produced using this method of tissue displacement that may be characterized by gradable behavioral and morphological assessment.

There has been growing awareness of the correlation between an episode of traumatic brain injury (TBI) and the development of Alzheimer’s disease (AD) later in life. It has been reported that TBI accelerated amyloid-β (Aβ) pathology and cognitive decline in the several lines of AD model mice. However, the short-term and long-term effects of TBI by the weight-drop method on amyloid-β pathology and cognitive performance are unclear in wild-type (WT) mice. Hence, we examined AD-related histopathological changes and cognitive impairment after TBI in wild-type C57BL6J mice. Five- to seven-month-old WT mice were subjected to either TBI by the weight-drop method or a sham treatment. Seven days after TBI, the WT mice exhibited significantly lower spatial learning than the sham-treated WT mice. However, 28 days after TBI, the cognitive impairment in the TBI-treated WT mice recovered. Correspondingly, while significant amyloid-β (Aβ) plaques and amyloid precursor protein (APP) accumulation were observed in the TBI-treated mouse hippocampus 7 days after TBI, the Aβ deposition was no longer apparent 28 days after TBI. Thus, TBI induced transient amyloid-β deposition and acute cognitive impairments in the WT mice. The present study suggests that the TBI could be a risk factor for acute cognitive impairment even when genetic and hereditary predispositions are not involved. The system might be useful for evaluating and developing a pharmacological treatment for the acute cognitive deficits.

Summary Distributed acoustic sensing (DAS) technology lately has undertaken significant developments and been recognised as a novel versatile approach for borehole seismic exploration. We conducted a series of acquisitions at the Curtin well site to evaluate the performance of several low power sources in conjunction with fibre optic cables as the receivers. We have tested the effectiveness of a small weight drop, a percussion rod and a parker using optical fibre cemented behind the casing as sensors. Results demonstrate that such inexpensive sources with minimal environmental impact are suitable for downhole seismic with DAS. This combination is highly applicable to the wide range of tasks in mining exploration, near-surface investigations and monitoring, cross-hole studies.

The degree of brain injury is the governing factor for the magnitude of the patient's psycho- and physiological deficits post-injury, and the associated long-term consequences. The present scaling method used to segregate the patients among mild, moderate and severe phases of traumatic brain injury (TBI) has major limitations; however, a more continuous stratification of TBI is still elusive. With the anticipation that differentiating molecular markers could be the backbone of a robust method to triage TBI, we used a modified closed-head injury (CHI) Marmarou model with two impact heights (IH). By definition, IH directly correlates with the impact force causing TBI. In our modified CHI model, the rat skull was fitted with a helmet to permit a diffuse axonal injury. With the frontal cortex as the focal point of injury, the adjacent brain regions (hippocampus, HC and cerebellum, CB) were susceptible to diffuse secondary shock injury. At 8 days post injury (po.i.), rats impacted by 120 cm IH (IH120) took a longer time to find an escape route in the Barnes maze as compared to those impacted by 100 cm IH (IH100). Using a time-resolved interrogation of the transcriptomic landscape of HC and CB tissues, we mined those genes that altered their regulations in correlation with the variable IHs. At 14 days po.i., when all rats demonstrated nearly normal visuomotor performance, the bio-functional analysis suggested an advanced healing mechanism in the HC of IH100 group. In contrast, the HC of IH120 group displayed a delayed healing with evidence of active cell death networks. Combining whole genome rat microarrays with behavioral analysis provided the insight of neuroprotective signals that could be the foundation of the next generation triage for TBI patients.

Post-traumatic epilepsy (PTE) is defined as the development of unprovoked seizures in a delayed fashion after traumatic brain injury (TBI). PTE lies at the intersection of two distinct fields of study, epilepsy and neurotrauma. TBI is associated with a myriad of both focal and diffuse anatomic injuries, and an ideal animal model of epilepsy after TBI must mimic the characteristics of human PTE. The three most commonly used models of TBI are lateral fluid percussion, controlled cortical injury, and weight drop. Much of what is known about PTE has resulted from use of these models. In this review, we describe the most commonly used animal models of TBI with special attention to their advantages and disadvantages with respect to their use as a model of PTE.

Study Design: Calf spine model study. Purpose: To describe a technique of creating thoracolumbar burst fractures in calf spine model by low weight drop weight. Overview of Literature: Burst fractures are one of the commonest types of thoracolumbar fractures and their treatment is controversial. Biomechanical studies aid in the decision of treatment of these fractures. A simple method of creation of burst fractures would help these biomechanical studies. Methods: Ten specimens of thoracolumbar spines harvested from 6–8 week old calves were weakened at the target vertebra by standardized osteotomy cuts. Burst fractures were created by dropping a 5-kg of weight from a height of 1.2 m using an in-house device. An accelerometer attached to the weight measured the acceleration at the point of impact. Results: Average weight and bone mineral density of the specimens was 390 g and 0.67 g/cm 2 , respectively. Computed tomography scan analysis of the fractures revealed McCormack grade 2 and grade 3 fractures in 5 and 3 specimens, respectively, Dennis type 2B in 4, type 2A burst fractures in 5 specimens and fracture dislocation in 1 specimen, AO type A3.1.1 in 4 specimens, type A3.2.2 in 4 and type A3.3.3 in 2 specimens. Vertical laminar split fracture was seen in 6 specimens. Average acceleration and energy at impact was 9.04 m/sec and 54.24 Nm, respectively. Conclusions: We describe a technique to create thoracolumbar burst fractures in calf spine by a drop weight method using a device that is simple to operate and easy to construct. The method is consistent and produces fractures similar to those occurring naturally, and can be considered as an alternative method for creating burst fractures in biomechanical studies.

Traumatic brain injury (TBI) is a leading cause of death and disability in individuals worldwide. Producing a clinically relevant TBI model in small-sized animals remains fairly challenging. For good screening of potential therapeutics, which are effective in the treatment of TBI, animal models of TBI should be established and standardized. In this study, we established mouse models of closed head injury using the Shohami weight-drop method with some modifications concerning cognitive deficiency assessment and provided a detailed description of the severe TBI animal model. We found that 250 g falling weight from 2 cm height produced severe closed head injury in C57BL/6 male mice. Cognitive disorders in mice with severe closed head injury could be detected using passive avoidance test on day 7 after injury. Findings from this study indicate that weight-drop injury animal models are suitable for further screening of brain neuroprotectants and potentially are similar to those seen in human TBI.

Background Spinal cord injury (SCI) may result in neuromotor, sensory, and autonomic function damages. Edema because of spinal cord trauma can reach serious dimensions. The aim of this study was to histologically evaluate the effects of duraplasty on neural tissues. Methods Twenty-eight Wistar rats were randomly divided into 4 experimental groups: group 1 received laminectomy without SCI (sham); group 2 received laminectomy and SCI with the weight drop method; group 3 received laminectomy, SCI, and duraplasty within the first 6–8 hours of SCI; and group 4 received laminectomy, SCI, and duraplasty after 24 hours of SCI. The neurologic functions of the rats were tested periodically. All animals were euthanized 28 days after the surgery. Histopathologic and immunohistochemical evaluations were performed, and Kruskal-Wallis tests were used for statistical comparison of data between the groups. Results There was no significant difference in the Tarlov examination scores from different time points between the groups. The number of neurons stained with nuclear factor kappa beta was higher in group 3 than groups 1 and 4. The number of neurons stained with terminal deoxynucleotidyl transferase dUTP nick-end labeling was higher in group 2 than group 3. Conclusions Decompressive laminectomy is a procedure frequently used in spinal trauma surgery. However, it is often unclear whether the decompression is fully adequate. Our results will aid the development of further studies regarding the reliability of duraplasty in the treatment of SCI.

BACKGROUND: Repetitive traumatic brain injury (RTBI) has gained much attention in this decade, especially in contact sports athletes and military personals. This injury is correlated with early neurodegenerative changes that are marked with the increased of tau protein. Turmeric extract (TE) is a well-known anti-inflammation and antioxidant that decreases tau protein expression in neurodegenerative disease. AIM: This study aimed to prove the effect of TE on tau protein level after RTBI. METHODS: Forty Sprague Dawley mice were divided into four groups, i.e. negative sham control group, the control group, and two treatment groups. A weight drop model was used by applying a 40-gram mass that was dropped from a 1-meter height onto the vertex of the head, with a total frequency of 12 times, divided into 4 days (day 0, 1, 3, and 7; 3 traumas on each day). TE was given to all treatment groups with 500 mg/kg BW doses once daily. The first treatment group had TE for seven days along the trauma. The second treatment group had pretreatment TE extract, given from seven days before first trauma and continued along the trauma protocol days. Tau protein level was measured on brain and serum using ELISA method. RESULTS: There was a significant reduction of tau protein level in both treatment groups compared to trauma group, either in serum or brain, but we also found significant differences regarding brain tau level between the treatment and pretreatment group. CONCLUSION: This study might provide evidence of with the role of pretreatment TE in RTBI.

Venous thromboembolism prophylaxis in the general trauma population is well established. However, risk of increased intracranial hemorrhage in traumatic brain injury (TBI) population is of concern. The aim for this study is to identify a reproducible model of mild traumatic brain injury (mTBI), evaluated by clinical and histological markers and test the hypothesis that enoxaparin increases the risk of spontaneous brain hemorrhage.40 male Sprague Dawley rats were randomly assigned to 5 groups: group 1 (sham) with no TBI along with 4 groups comparing mTBI with and without pharmacological intervention using enoxaparin at 24 h and 72 h respectively. Mild traumatic brain injury was induced using a weight drop apparatus, with a clinical endpoint of time to right (TTR), along with histological and spectrophotometer analysis for qualitative hemorrhage.There is a statistically significant difference between group 1 (sham) and all other groups with a mean longer time to right of 64 s (p = 0.005) in the mTBI groups. There was a statistically significant difference between group 1 (sham) and all other groups with an increase of 6 g/dL hemoglobin (p 0.001) in the mTBI groups with no difference in hemorrhage between groups that were treated with enoxaparin.The weight drop apparatus is a reproducible model for mTBI that has correlations with clinical and qualitative data. This model was able to produce clinical signs of concussion, as reflected by longer TTR and increased hemoglobin in the mTBI groups. Upon further analysis, there wasno increase in hemorrhage in the pharmacological intervention groups with enoxaparin.

Patient’s age affects the course of posttraumatic inflammation and recovery after TBI. The goal of the research was to identify the differences in neuroimmune deficiencies in young and old animals after experimental TBI. The research was carried out using male Wistar rats aged 3 and 18 months. Mild TBI was caused by weight drop TBI model. A group of animals was injected abdominally with 30 mkg/kg recombinant human interleukin-2 (Ronkoleukin, Biotech) daily for three days, starting 72 hours after TBI. The control group consisted of intact animals and rats who did not receive rIL-2 prior to TBI (n = 5 for both groups). The results obtained have shown that old animals after mild TBI had different testosterone and proliferative activity levels than the young ones; the injection of rIL-2 led to an increase in neurotrophic factors (testosterone and BDNF) without causing additional activation of lymphocytes.

Weight drop style impact systems can be used as a tool to induce the acute spinal cord injury (SCI) in large animals. We introduce our cost-effective impact system for the SCI modeling without using an expensive high speed camera and a vision system. And the practical output signals obtained in porcine in-vivo experiments using our system have been analyzed to check the effects of surrounding bones, tissues, and bleedings over the impacting target position in the spinal cord. By analyzing the output signals, the abnormal impact results hindered by the surrounding structures could have been separated from the normally impacted ones.

Despite the enormity of the problem and the lack of new therapies, research in the pre-clinical arena specifically using pediatric traumatic brain injury (TBI) models is limited. In this review, some of the key models addressing both the age spectrum of pediatric TBI and its unique injury mechanisms will be highlighted. Four topics will be addressed, namely, (1) unique facets of the developing brain important to TBI model development, (2) a description of some of the most commonly used pre-clinical models of severe pediatric TBI including work in both rodents and large animals, (3) a description of the pediatric models of mild TBI and repetitive mild TBI that are relatively new, and finally (4) a discussion of challenges, gaps, and potential future directions to further advance work in pediatric TBI models. This narrative review on the topic of pediatric TBI models was based on review of PUBMED/Medline along with a synthesis of information on key factors in pre-clinical and clinical developmental brain injury that influence TBI modeling. In the contemporary literature, six types of models have been used in rats including weight drop, fluid percussion injury (FPI), impact acceleration, controlled cortical impact (CCI), mechanical shaking, and closed head modifications of CCI. In mice, studies are largely restricted to CCI. In large animals, FPI and rotational injury have been used in piglets and shake injury has also been used in lambs. Most of the studies have been in severe injury models, although more recently, studies have begun to explore mild and repetitive mild injuries to study concussion. Given the emerging importance of TBI in infants and children, the morbidity and mortality that is produced, along with its purported link to the development of chronic neurodegenerative diseases, studies in these models merit greater systematic investigations along with consortium-type approaches and long-term follow-up to translate new therapies to the bedside.

Traumatic brain injury (TBI) can produce life-long disabilities, including anxiety, cognitive, balance, and motor deficits. The experimental model of closed head TBI (cTBI) induced by weight drop/impact acceleration is known to produce hallmark TBI injuries. However, comprehensive long-term characterization of comorbidities induced by graded mild-to- mild/moderate intensities using this experimental cTBI model has not been reported. The present study used two intensities of weight drop (1.0 m and 1.25 m/450 g) to produce cTBI in a rat model to investigate initial and long-term disability of four comorbidities: anxiety, cognitive, vestibulomotor, and spinal reflex that related to spasticity. TBI and sham injuries were produced under general anesthesia. Time for righting recoveries post-TBI recorded to estimate duration of unconsciousness, revealed that the TBI mild/moderate group required a mean of 1 min 27 sec longer than the values observed for noninjured sham animals. Screening magnetic resonance imaging images revealed no anatomical changes, mid-line shifts, or hemorrhagic volumes. However, compared to sham injuries, significant long-term anxiety, cognitive, balance, and physiological changes in motor reflex related to spasticity were observed post-TBI for both TBI intensities. The longitudinal trajectory of anxiety and balance disabilities tested at 2, 4, 8, and 18 weeks revealed progressively worsening disabilities. In general, disability magnitudes were proportional to injury intensity for three of the four measures. A natural hypothesis would pose that all disabilities would increase incrementally relative to injury severity. Surprisingly, anxiety disability progressed over time to be greater in the mildest injury. Collectively, translational implications of these observations suggest that patients with mild TBI should be evaluated longitudinally at multiple time points, and that anxiety disorder could potentially have a particularly low threshold for appearance and progressively worsen post-injury.

Traumatic brain injury (TBI), induced by impact of an object with the head, is a major health problem worldwide. Rats are a well-established animal analogue for study of TBI and the weight-drop impact-acceleration (WDIA) method is a well-established model in rats for creating diffuse TBI, the most common form of TBI seen in humans. However, little is known of the biomechanics of the WDIA method and, to address this, we have developed a four-degrees-of-freedom multi-body mass-spring-damper model for the WDIA test in rats. An analytical expression of the maximum skull acceleration, one of the important head injury predictor, was derived and it shows that the maximum skull acceleration is proportional to the impact velocity but independent of the impactor mass. Furthermore, a dimensional analysis disclosed that the maximum force on the brain and maximum relative displacement between brain and skull are also linearly proportional to impact velocity. Additionally, the effects of the impactor mass were examined through a parametric study from the developed multi-body dynamics model. It was found that increasing impactor mass increased these two brain injury predictors.