A matrix metalloproteinase-responsive hydrogel system controls angiogenic peptide release for repair of cerebral ischemia/reperfusion injury

Vascular endothelial growth factor and its mimic peptide KLTWQELYQLKYKGI(QK)are widely used as the most potent angiogenic factors for the treatment of multiple ischemic diseases.However,conventional topical drug delivery often results in a burst release of the drug,leading to transient retention(inefficacy)and undesirable diffusion(toxicity)in vivo.Therefore,a drug delivery system that responds to changes in the microenvironment of tissue regeneration and controls vascular endothelial growth factor release is crucial to improve the treatment of ischemic stroke.Matrix metalloproteinase-2(MMP-2)is gradually upregulated after cerebral ischemia.Herein,vascular endothelial growth factor mimic peptide QK was self-assembled with MMP-2-cleaved peptide PLGLAG(TIMP)and customizable peptide amphiphilic(PA)molecules to construct nanofiber hydrogel PA-TIMP-QK.PA-TIMP-QK was found to control the delivery of QK by MMP-2 upregulation after cerebral ischemia/reperfusion and had a similar biological activity with vascular endothelial growth factor in vitro.The results indicated that PA-TIMP-QK promoted neuronal survival,restored local blood circulation,reduced blood-brain barrier permeability,and restored motor function.These findings suggest that the self-assembling nanofiber hydrogel PA-TIMP-QK may provide an intelligent drug delivery system that responds to the microenvironment and promotes regeneration and repair after cerebral ischemia/reperfusion injury.

Passive activity enhances residual control ability in patients with complete spinal cord injury

Patients with complete spinal cord injury retain the potential for volitional muscle activity in muscles located below the spinal injury level.However,because of prolonged inactivity,initial attempts to activate these muscles may not effectively engage any of the remaining neurons in the descending pathway.A previous study unexpectedly found that a brief clinical round of passive activity significantly increased volitional muscle activation,as measured by surface electromyography.In this study,we further explored the effect of passive activity on surface electromyographic signals during volitional control tasks among individuals with complete spinal cord injury.Eleven patients with chronic complete thoracic spinal cord injury were recruited.Surface electromyography data from eight major leg muscles were acquired and compared before and after the passive activity protocol.The results indicated that the passive activity led to an increased number of activated volitional muscles and an increased frequency of activation.Although the cumulative root mean square of surface electromyography amplitude for volitional control of movement showed a slight increase after passive activity,the difference was not statistically significant.These findings suggest that brief passive activity may enhance the ability to initiate volitional muscle activity during surface electromyography tasks and underscore the potential of passive activity for improving residual motor control among patients with motor complete spinal cord injury.

Safety and effectiveness of electromyography-induced rehabilitation treatment after epidural electrical stimulation for spinal cord injury:study protocol for a prospective,randomized,controlled trial

Epidural electrical stimulation is a new treatment method for spinal cord injury(SCI).Its efficacy and safety have previously been reported.Rehabilitation treatment after epidural electrical stimulation is important to ensure and improve the postoperative efficacy of epidural electrical stimulation in patients with SCI.Considering that electromyography(EMG)-induced rehabilitation treatment can accurately match the muscle contraction of patients with SCI,we designed a study protocol for a prospective,randomized controlled trial.In this trial,on the premise of adjusting the spinal cord electrical stimulator to obtain the maximum EMG signal of the target muscle,patients with SCI receiving epidural electrical stimulation will undergo EMG-induced rehabilitation treatment.Recovery of muscle strength of key muscles,quality of life,safety and therapeutic effects will be monitored.Twenty patients with SCI who are scheduled to undergo epidural electrical stimulation in Shanghai Ruijin Rehabilitation Hospital will be randomly divided into two groups with 10 patients per group.The control group will receive conventional rehabilitation treatment.The EMG-induced rehabilitation group will receive EMG-induced rehabilitation treatment of the target muscles of the upper and lower limbs based on conventional rehabilitation treatment.After rehabilitation treatment,follow up for all patients will occur at 2 weeks and 1,3 and 6 months.The primary outcome measure of this trial will be evaluation of target muscle recovery using the Manual Muscle Testing grading scale.Secondary outcome measures will include modified Barthel Index scores,integrated EMG values,the visual analogue scale,Spinal Cord Independence Measure scores,and modified Ashworth scale scores.The safety indicator will be the incidence of adverse events.This trial will collect data regarding the therapeutic effects of EMG-induced rehabilitation in patients with SCI receiving epidural electrical stimulation for 6 months after rehabilitation treatment.Findings from this trial will help develop rehabilitation methods in patients with SCI after epidural electrical stimulation.This study protocol was approved by Ethics Committee of Shanghai Ruijin Rehabilitation Hospital(Approval No.RKIRB2022-12)on February 15,2022 and was registered with Chinese Clinical Trial Registry(registration number:ChiCTR2200061674;date:June 30,2022).Study protocol version:1.0.

Endorepellin downregulation promotes angiogenesis after experimental traumatic brain injury

Endorepellin plays a key role in the regulation of angiogenesis,but its effects on angiogenesis after traumatic brain injury are unclear.This study explored the effects of endorepellin on angiogenesis and neurobehavioral outcomes after traumatic brain injury in mice.Mice were randomly divided into four groups:sham,controlled cortical impact only,adeno-associated virus(AAV)-green fluorescent protein,and AAV-shEndorepellin-green fluorescent protein groups.In the controlled cortical impact model,the transduction of AAV-shEndorepellin-green fluorescent protein downregulated endorepellin while increasing the number of CD31+/Ki-67+proliferating endothelial cells and the functional microvessel density in mouse brain.These changes resulted in improved neurological function compared with controlled cortical impact mice.Western blotting revealed increased expression of vascular endothelial growth factor and angiopoietin-1 in mice treated with AAV-shEndorepellin-green fluorescent protein.Synchrotron radiation angiography showed that endorepellin downregulation promoted angiogenesis and increased cortical neovascularization,which may further improve neurobehavioral outcomes.Furthermore,an in vitro study showed that downregulation of endorepellin increased tube formation by human umbilical vein endothelial cells compared with a control.Mechanistic analysis found that endorepellin downregulation may mediate angiogenesis by activating vascular endothelial growth factor-and angiopoietin-1-related signaling pathways.

Edaravone-loaded poly(amino acid) nanogel inhibits ferroptosis for neuroprotection in cerebral ischemia injury

Neurological injury caused by ischemic stroke is a major cause of permanent disability and death. The currently available neuroprotective drugs fail to achieve desired therapeutic efficacy mainly due to short circulation half-life and poor blood−brain barrier (BBB) permeability. For that, an edaravone-loaded pH/glutathione (pH/GSH) dual-responsive poly(amino acid) nanogel (NG/EDA) was developed to improve the neuroprotection of EDA. The nanogel was triggered by acidic and EDA-induced high-level GSH microenvironments, which enabled the selective and sustained release of EDA at the site of ischemic injury. NG/EDA exhibited a uniform sub-spherical morphology with a mean hydrodynamic diameter of 112.3 ± 8.2 nm. NG/EDA efficiently accumulated at the cerebral ischemic injury site of permanent middle cerebral artery occlusion (pMCAO) mice, showing an efficient BBB crossing feature. Notably, NG/EDA with 50 µM EDA significantly increased neuron survival (29.3%) following oxygen and glucose deprivation by inhibiting ferroptosis. In addition, administering NG/EDA for 7 d significantly reduced infarct volume to 22.2% ± 7.2% and decreased neurobehavioral scores from 9.0 ± 0.6 to 2.0 ± 0.8. Such a pH/GSH dual-responsive nanoplatform might provide a unique and promising modality for neuroprotection in ischemic stroke and other central nervous system diseases.

Infection control and prevention in burn victims:The role of nurses

Burn injury is a major public health concern,with an estimated 180,000 deaths each year associated with burn-related infections.The majority of these occur in low-and middle-income countries,and almost two-thirds occur in the World Health Organization African and South-East Asia Regions.There is a risk of an escalation of burn injury site infections if nurses who are directly involved in burn care do not develop a mechanism to mitigate this risk in the coming years.Hence,this study aims at explaining what burn injuries are and how nurses can prevent the occurrence of infection among burn victims.This review analyzed published studies using keywords such as burn injury,infection in burn patients,and nurses’involvement in infection prevention and control(IPC)on search engines such as PubMed,Science Direct,and Google Scholar.The literature was retrieved and reviewed for eligibility to capture just the variables indicated in this seminar objective;the date range chosen in the literature search was from 2015 to 2023.The study found that many patients die from burn injuries as a result of exposure to infection and most nurses are not adequately informed about infection control.The study also found that nurses’responsibilities include proper hand hygiene,wound care,the use of personal protective equipment,antibiotic medication,cleaning the patient’s surroundings,and preventing patient cross-contamination.Burn injuries pose a significant risk to patients,necessitating infection control and prevention.Therefore,nurses in burn units should be informed on IPC practices and also educate patients,families,and coworkers on their importance.

Pain management in acute musculoskeletal injury: Effect of opioid vs nonopioid medications

BACKGROUND The use of opioids for pain is linked to an increased risk of developing opioid use disorder,and has resulted in the emergence of the opioid crisis over the last few years.AIM The systematic review question is“How does the use of opioid medications in pain management,compared with non-opioid medications,affect pain intensity over the short,intermediate,and long-term in adults with acute traumatic pain?”.METHODS The protocol was prospectively registered on the International Prospective Re-gister of Systematic Reviews:CRD42021279639.Medline and Google Scholar were electronically searched for controlled peer-reviewed studies published in full,with the PICO framework:P:Adult patients with traumatic injuries,I:Opioid medications,C:Non-opioid medi-cations,O:A minimum clinically important difference(MCID)in pain.RESULTS After full-text screening,we included 14 studies in the qualitative synthesis.Of these 14 studies,12 were rando-mized clinical trials(RCTs)and 2 were pseudo-RCTs with a total of 2347 patients enrolled.There was heteroge-neity in both medication utilized and outcome in these studies;only two studies were homogeneous regarding the type of study conducted,the opioid used,its comparator,and the outcome explored.The MCID was evaluated in 8 studies,while in 6 studies,any measured pain reduction was considered as an outcome.In 11 cases,the setting of care was the Emergency Department;in 2 cases,care occurred out-of-hospital;and in one case,the setting was not well-specified.The included studies were found to have a low-moderate risk of bias.CONCLUSION Non-opioids can be considered an alternative to opioids for short-term pain management of acute musculoskeletal injury.Intravenous ketamine may cause more adverse events than other routes of administration.

Effect of Prone Position Ventilation in Patients with Severe Craniocerebral Injury Complicated with Pulmonary Infection

Objective:To investigate the effects of prone ventilation in patients with severe traumatic brain injury combined with pulmonary infection.Methods:A total of 100 patients with severe traumatic brain injury combined with pulmonary infection in the hospital were randomly divided into a prone ventilation group and a conventional ventilation group,with 50 patients in each group.The Glasgow Coma Scale(GCS)score,APACHE II score,sputum culture results,oxygenation indicators,and prognosis were compared between the two groups.Data were processed using SPSS 25.0 statistical software,and t-tests and chi-square tests were used to compare continuous and categorical variables,respectively.Results:The experimental group showed better oxygenation indicators,a lower positive rate of sputum cultures,and reduced intracranial pressure compared to the control group(all P<0.05).Multivariate Cox regression analysis indicated that GCS score,APACHE II score,and prone ventilation were independent risk factors affecting patient prognosis(all P<0.05).Conclusion:Prone ventilation can improve oxygenation,reduce the risk of pulmonary infection,and decrease intracranial pressure in patients with severe traumatic brain injury combined with pulmonary infection,thereby improving patient prognosis.GCS score and APACHE II score can serve as important indicators for prognostic evaluation.

ESTIMAING AMOUNT OF EXPLOSIVE FOR FRACTURE PLANE CONTROL BLASTING WITH NOTCHED BOREHOLES

With the development of fracture mechanics,the fracture plane control blasting with notched borcholes hascome into being.This technique is used to create a satisfactory presplit along the contour of an excavation inrock.However,the amount of explosive loaded in each hol usually is determined by trial and error.Because ofthis,two approaches estimating the amount of explosive for the blasting technique are suggested.

Human umbilical cord mesenchymal stem cells to treat spinal cord injury in the early chronic phase: study protocol for a prospective, multicenter, randomized, placebo-controlled, single-blinded clinical trial

Human umbilical cord mesenchymal stem cells(hUC-MSCs)support revascularization,inhibition of inflammation,regulation of apoptosis,and promotion of the release of beneficial factors.Thus,they are regarded as a promising candidate for the treatment of intractable spinal cord injury(SCI).Clinical studies on patients with early chronic SCI(from 2 months to 1 year post-injury),which is clinically common,are rare;therefore,we will conduct a prospective,multicenter,randomized,placebo-controlled,single-blinded clinical trial at the Third Affiliated Hospital of Sun Yat-sen University,West China Hospital of Sichuan University,and Shanghai East Hospital,Tongji University School of Medicine,China.The trial plans to recruit 66 early chronic SCI patients.Eligible patients will undergo randomization at a 2:1 ratio to two arms:the observation group and the control group.Subjects in the observation group will receive four intrathecal transplantations of stem cells,with a dosage of 1×106/kg,at one calendar month intervals.Subjects in the control group will receive intrathecal administrations of 10 mL sterile normal saline in place of the stem cell transplantations.Clinical safety will be assessed by the analysis of adverse events and laboratory tests.The American Spinal Injury Association(ASIA)total score will be the primary efficacy endpoint,and the secondary efficacy outcomes will be the following:ASIA impairment scale,International Association of Neural Restoration-Spinal Cord Injury Functional Rating Scale,muscle tension,electromyogram,cortical motor and cortical sensory evoked potentials,residual urine volume,magnetic resonance imaging–diffusion tensor imaging,T cell subtypes in serum,neurotrophic factors and inflammatory factors in both serum and cerebrospinal fluid.All evaluations will be performed at 1,3,6,and 12 months following the final intrathecal administration.During the entire study procedure,all adverse events will be reported as soon as they are noted.This trial is designed to evaluate the clinical safety and efficacy of subarachnoid transplantation of hUC-MSCs to treat early chronic SCI.Moreover,it will establish whether cytotherapy can ameliorate local hostile microenvironments,promote tracking fiber regeneration,and strengthen spinal conduction ability,thus improving overall motor,sensory,and micturition/defecation function in patients with early chronic SCI.This study was approved by the Stem Cell Research Ethics Committee of the Third Affiliated Hospital of Sun Yat-sen University,China(approval No.[2018]-02)on March 30,2018,and was registered with ClinicalTrials.gov(registration No.NCT03521323)on April 12,2018.The revised trial protocol(protocol version 4.0)was approved by the Stem Cell Research Ethics Committee of the Third Affiliated Hospital of Sun Yat-sen University,China(approval No.[2019]-10)on February 25,2019,and released on ClinicalTrials.gov on April 29,2019.

Acute histopathological responses and long-term behavioral outcomes in mice with graded controlled cortical impact injury

While animal models of controlled cortical impact often display short-term motor dysfunction after injury, histological examinations do not show severe cortical damage. Thus, this model requires further improvement. Mice were subjected to injury at three severities using a Pin-Point^(TM)-controlled cortical impact device to establish secondary brain injury mouse models. Twenty-four hours after injury, hematoxylin-eosin staining, Fluoro-Jade B histofluorescence, and immunohistochemistry were performed for brain slices. Compared to the uninjured side, we observed differences of histopathological findings, neuronal degeneration, and glial cell number in the CA2 and CA3 regions of the hippocampus on the injured side. The Morris water maze task and beam-walking test verified long-term(14–28 days) spatial learning/memory and motor balance. To conclude, the histopathological responses were positively correlated with the degree of damage,as were the long-term behavioral manifestations after controlled cortical impact. All animal procedures were approved by the Institutional Animal Care and Use Committee at Shanghai Jiao Tong University School of Medicine.

Myelotomy promotes locomotor recovery in rats subjected to spinal cord injury： a meta-analysis of six randomized controlled trials

OBJECTIVE： To investigate the effects of myelotomy on locomotor recovery in rats subjected to spinal cord injury. DATA SOURCES： Electronic databases including Pub Med, Science Citation Index, Cochrane Library, China National Knowledge Infrastructure, Chinese Journals Full-text Database, China Biology Medicine disc, and Wanfang Database were searched to retrieve related studies published before September 2017. The Me SH terms（the Medical Subject Headings） such as ＂myelotomy＂, ＂spinal cord injuries＂, ＂rats＂, ＂randomized controlled trial＂ and all related entry terms were searched. DATA SELECTION： Randomized controlled trials using myelotomy for the treatment of acute spinal cord injury in rats were included. Basso, Beattie, and Bresnahan scores were adopted as the evaluation method. Rev Man Software（version 5.3） was used for data processing. The χ^2 and I^2 tests were used to assess heterogeneity. Using a random-effects model, a subgroup analysis was conducted to analyze the source of the heterogeneity. OUTCOME MEASURES： Basso, Beattie, and Bresnahan scores were observed 1–6 weeks after spinal cord injury.RESULTS： Six animal trials were included, using a total of 143 lab rats. The included trials were divided into two subgroups by injury degrees（moderate or severe）. The pooled results showed that, 1–6 weeks after spinal cord injury, the overall Basso, Beattie, and Bresnahan score was significantly higher in the myelotomy group than in the contusion group（weighted mean difference（WMD） = 0.60; 95% confidence interval（CI）： 0.23–0.97; P = 0.001; WMD = 2.10; 95% CI： 1.56–2.64; P 〈 0.001; WMD = 2.65; 95% CI： 1.73–3.57; P 〈 0.001; WMD = 1.66; 95% CI： 0.80–2.52; P 〈 0.001; WMD = 2.09; 95% CI： 0.92–3.26, P 〈 0.001; WMD = 2.25; 95% CI： 1.06–3.44, P 〈 0.001）. The overall heterogeneity was high（I^2 = 85%; I^2 = 95%; I^2 = 94%; I^2 = 88%; I^2 = 91%; I^2 = 89%）. The results in the moderate injury subgroup showed that Basso, Beattie, and Bresnahan scores were significantly higher in the myelotomy group than in the contusion group（WMD = 0.91, 95% CI： 0.52–1.3, P 〈 0.001; WMD = 2.10; 95% CI： 1.56–2.64, P 〈 0.001; WMD = 2.65; 95% CI： 1.73–3.57, P 〈 0.001; WMD = 2.50, 95% CI： 1.72–3.28, P 〈 0.001; WMD = 3.29, 95% CI： 2.21–4.38, P 〈 0.001; WMD = 3.27; 95% CI： 2.31–4.23, P 〈 0.001）. The relevant heterogeneity was low. However, there were no significant differences in Basso, Beattie, and Bresnahan scores between the myelotomy and contusion groups in the severe injury subgroup at 2 and 3 weeks after the injury（P = 0.75; P = 0.92）. CONCLUSION： To date, this is the first attempt to summarize the potential effect of myelotomy on locomotor recovery in rats with spinal cord injury. Our findings conclude that myelotomy promotes locomotor recovery in rats with spinal cord injury, especially in those with moderate injury.

Impaired motor control after sport-related concussion could increase risk for musculoskeletal injury:Implications for clinical management and rehabilitation

This review presents a conceptual framework and supporting evidence that links impaired motor control after sport-related concussion(SRC)to increased risk for musculoskeletal injury.Multiple studies have found that athletes who are post-SRC have higher risk for musculoskeletal injury compared to their counterparts.A small body of research suggests that impairments in motor control are associated with musculoskeletal injury risk.Motor control involves the perception and processing of sensory information and subsequent coordination of motor output within the central nervous system to perform a motor task.Motor control is inclusive of motor planning and motor learning.If sensory information is not accurately perceived or there is interference with sensory information processing and cognition,motor function will be altered,and an athlete may become vulnerable to injury during sport participation.Athletes with SRC show neuroanatomic and neurophysiological changes relevant to motor control even after meeting return to sport criteria,including a normal neurological examination,resolution of symptoms,and return to baseline function on traditional concussion testing.In conjunction,altered motor function is demonstrated after SRC in muscle activation and force production,movement patterns,balance/postural stability,and motor task performance,especially performance of a motor task paired with a cognitive task(i.e.,dual-task condition).The clinical implications of this conceptual framework include a need to intentionally address motor control impairments after SRC to mitigate musculoskeletal injury risk and to monitor motor control as the athlete progresses through the return to sport continuum.

Safety control for powder compaction of initiating explosive device

Powder compaction is one of the most crucial processes in initiating explosive device manufacturing. The quality of powder compaction may influence the performances of product directly. Traditional powder compaction mainly makes use of manual gravitational spiral loading machine or lever loading machine. Potential accident by the strike in powder compaction of initiating explosive device could risk life, property and the environment. To prevent this risk, automatic control system and control strategy can be used to guarantee no strike in pressing process. The scope of this paper is to analyze and review the control strategy for powder compact and discuss the experimental results for the application of the proposed strategy.

Distance Control and Positive Security for Intrinsic Equipment Working in Explosive Potential Atmospheres

In this paper, intrinsic safety and positive security distance control for an up/down elevator which extracts the materials from an underground coal mine is approached. For a better understanding of intrinsic safety and positive security, the first part of the paper describes the potential risk the workers are facing while working in dangerous environments like coal mining with “grisou” atmospheres and what the conditions of an unfortunate event to take place are. We presented the diagram and working principle for intrinsic safety equipment used in potential explosive areas based on which we modeled and simulated the intrinsic and positive security distance control in order to get a software solution for it. We created an algorithm and simulated the process in Matlab Simulink. The simulation results done in Matlab Simulink were then entered into a Moeller PLC using a ladder-type programming language. For protection against explosive atmospheres, the PLC is inserted into a metal housing with intrinsic protection and Positive Security.

Selection of suitable internal controls for gene expression normalization in rats with spinal cord injury

There is a lack of systematic research on the expression of internal control genes used for gene expression normalization in real-time reverse transcription polymerase chain reaction in spinal cord injury research.In this study,we used rat models of spinal cord hemisection to analyze the expression stability of 13 commonly applied reference genes:Actb,Ankrd27,CypA,Gapdh,Hprt1,Mrpl10,Pgk1,Rictor,Rn18s,Tbp,Ubc,Ubxn11,and Ywhaz.Our results show that the expression of Ankrd27,Ubc,and Tbp were stable after spinal cord injury,while Actb was the most unstable internal control gene.Ankrd27,Ubc,Tbp,and Actb were consequently used to investigate the effects of internal control genes with differing stabilities on the normalization of target gene expression.Target gene expression levels and changes over time were similar when Ankrd27,Ubc,and Tbp were used as internal controls but different when Actb was used as an internal control.We recommend that Ankrd27,Ubc,and Tbp are used as internal control genes for real-time reverse transcription polymerase chain reaction in spinal cord injury research.This study was approved by the Administration Committee of Experimental Animals,Jiangsu Province,China(approval No.20180304-008)on March 4,2018.

Pterostilbene Ameliorates Glycemic Control,Dyslipidemia and Liver Injury in Type 2 Diabetes Rats

Type 2 diabetes mellitus(T2DM)is typified by the increment of chronic blood glucose levels that is caused by an absolute and/or a relative deficiency of insulin,accounts for 90%of diabetes and causes a range of complications[1].

Study on Retinal Ganglion Cell Apoptosis after Explosive Injury of Eyeballs in Rabbits

Purpose: To explore the pathological changes of retinal ganglion cell apoptosis and its relation to the value of glutamate concentration in vitreous body after explosive injury of eyeballs in the rabbits.Method: Similar explosive injury models of eyeballs in 10 adult grey rabbits were made.The rabbits were killed on scheduled time. The retinal tissues of studied eyes and control eyes were obtained for the pathological examination with TUNEL method respectively.The value of glutamate in vitreum of injured eyes was measured and was compared with that of contralateral eyes. Statistical comparison analysis on the experiment data was performed.Result: The value of glutamate in vitreum of injured eyes was significantly higher than that of contralateral eyes in all rabbits in the study. A lot of TUNEL positive cells were observed in the injured eyes. It suggested that apoptosis of the retinal ganglion cells took place.Conclusion: We speculate that apoptosis of the retinal ganglion cells is perhaps among the causes resulting in damage of visual function after explosive injury of eyeballs and that the increasing of the value of glutamate in vitreum possibly associated with apoptosis of the retinal ganglion cells.

Effect of Seawater Soaking on Explosive Cornea Injury

Objective: To observe the changes in corneal tissue after explosive corneal injury and the effect of seawater soaking on the healing of cornea after explosive injury with the help ofoptical microscope. Methods: Make 10 similar explosive injury models of rabbit′s eyeball using 10 adult greyrabbits. For each rabbit, both eyes are artificially injured through explosion; its right eye is the comparison eye and after the injury the left eye is soaked in seawater for 30 minutes.Conduct slit lamp examinations, fluorescein dyeing, and ultrasonic cornea thickness metering on the corneas at intervals, that is, before the injury, 1 , 2, 3, 4, 5, 7, 9, 12, 15days after the injury respectively. Examine the corneas under the optical microscope andmake comparisons.Results: The corneal thickness of the experiment eye becomes apparently thicker than thatof the comparison eye after the injury. The corneal clouding of the former apparentlyaggravates compared with the latter. The healing of corneal epithelium in the injured eye isslower compared with that in the comparison eye. Comparative examination under the opticalmicroscope shows: after the injury, the corneal tissue of the experiment eye changesdistinctly, its healing is delayed and the vascularization degree becomes high in cornealstroma.Conclusion: Scars and vascularization of various degrees will appear in corneal stroma afterexplosive injuries. Seawater soaking will have bad effects on the healing of the corneainjured in explosions.

Characteristics of traumatic brain injury models:from macroscopic blood flow changes to microscopic mitochondrial changes

Controlled cortical impingement is a widely accepted method to induce traumatic brain injury to establish a traumatic brain injury animal model.A strike depth of 1 mm at a certain speed is recommended for a moderate brain injury and a depth of>2 mm is used to induce severe brain injury.However,the different effects and underlying mechanisms of these two model types have not been proven.This study investigated the changes in cerebral blood flow,differences in the degree of cortical damage,and differences in motor function under different injury parameters of 1 and 2 mm at injury speeds of 3,4,and 5 m/s.We also explored the functional changes and mitochondrial damage between the 1 and 2 mm groups in the acute(7 days)and chronic phases(30 days).The results showed that the cerebral blood flow in the injured area of the 1 mm group was significantly increased,and swelling and bulging of brain tissue,increased vascular permeability,and large-scale exudation occurred.In the 2 mm group,the main pathological changes were decreased cerebral blood flow,brain tissue loss,and cerebral vasospasm occlusion in the injured area.Substantial motor and cognitive impairments were found on day 7 after injury in the 2 mm group;at 30 days after injury,the motor function of the 2 mm group mice recovered significantly while cognitive impairment persisted.Transcriptome sequencing showed that compared with the 1 mm group,the 2 mm group expressed more ferroptosis-related genes.Morphological changes of mitochondria in the two groups on days 7 and 30 using transmission electron microscopy revealed that on day 7,the mitochondria in both groups shrank and the vacuoles became larger;on day 30,the mitochondria in the 1 mm group became larger,and the vacuoles in the 2 mm group remained enlarged.By analyzing the proportion of mitochondrial subgroups in different groups,we found that the model mice had different patterns of mitochondrial composition at different time periods,suggesting that the difference in the degree of damage among traumatic brain injury groups may reflect the mitochondrial changes.Taken together,differences in mitochondrial morphology and function between the 1 and 2 mm groups provide a new direction for the accurate classification of traumatic brain injury.Our results provide reliable data support and evaluation methods for promoting the establishment of standard mouse controlled cortical impingement model guidelines.