A rat model of multicompartmental traumatic injury and hemorrhagic shock induces bone marrow dysfunction and profound anemia

Background:Severe trauma is associated with systemic inflammation and organ dysfunction.Preclinical rodent trauma models are the mainstay of postinjury research but have been criticized for not fully replicating severe human trauma.The aim of this study was to create a rat model of multicompartmental injury which recreates profound traumatic injury.Methods:Male Sprague-Dawley rats were subjected to unilateral lung contusion and hemorrhagic shock(LCHS),multicompartmental polytrauma(PT)(unilateral lung contusion,hemorrhagic shock,cecectomy,bifemoral pseudofracture),or na?ve controls.Weight,plasma toll-l ike receptor 4(TLR4),hemoglobin,spleen to body weight ratio,bone marrow(BM)erythroid progenitor(CFU-GEMM,BFU-E,and CFU-E)growth,plasma granulocyte colony-stimulating factor(G-CSF)and right lung histologic injury were assessed on day 7,with significance defined as p values<0.05(*).Results:Polytrauma resulted in markedly more profound inhibition of weight gain compared to LCHS(p=0.0002)along with elevated plasma TLR4(p<0.0001),lower hemoglobin(p<0.0001),and enlarged spleen to body weight ratios(p=0.004).Both LCHS and PT demonstrated suppression of CFU-E and BFU-E growth compared to naive(p<0.03,p<0.01).Plasma G-CSF was elevated in PT compared to both na?ve and LCHS(p<0.0001,p=0.02).LCHS and PT demonstrated significant histologic right lung injury with poor alveolar wall integrity and interstitial edema.Conclusions:Multicompartmental injury as described here establishes a reproducible model of multicompartmental injury with worsened anemia,splenic tissue enlargement,weight loss,and increased inflammatory activity compared to a less severe model.This may serve as a more effective model to recreate profound traumatic injury to replicate the human inflammatory response postinjury.

Shock index and its variants as predictors of mortality in severe traumatic brain injury

BACKGROUND The increase in severe traumatic brain injury(sTBI)incidence is a worldwide phenomenon,resulting in a heavy disease burden in the public health systems,specifically in emerging countries.The shock index(SI)is a physiological parameter that indicates cardiovascular status and has been used as a tool to assess the presence and severity of shock,which is increased in sTBI.Considering the high mortality of sTBI,scrutinizing the predictive potential of SI and its variants is vital.AIM To describe the predictive potential of SI and its variants in sTBI.METHODS This study included 71 patients(61 men and 10 women)divided into two groups:Survival(S;n=49)and Non-survival(NS;n=22).The responses of blood pressure and heart rate(HR)were collected at admission and 48 h after admission.The SI,reverse SI(rSI),rSI multiplied by the Glasgow Coma Score(rSIG),and Age multiplied SI(AgeSI)were calculated.Group comparisons included Shapiro-Wilk tests,and independent samples t-tests.For predictive analysis,logistic regression,receiver operator curves(ROC)curves,and area under the curve(AUC)measurements were performed.RESULTS No significant differences between groups were identified for SI,rSI,or rSIG.The AgeSI was significantly higher in NS patients at 48 h following admission(S:26.32±14.2,and NS:37.27±17.8;P=0.016).Both the logistic regression and the AUC following ROC curve analysis showed that only AgeSI at 48 h was capable of predicting sTBI outcomes.CONCLUSION Although an altered balance between HR and blood pressure can provide insights into the adequacy of oxygen delivery to tissues and the overall cardiac function,only the AgeSI was a viable outcome-predictive tool in sTBI,warranting future research in different cohorts.

A Review of Nurses’ Perceptions of Traumatic Haemorrhagic Shock Management in Emergency Nursing

Haemorrhagic shock (HS) is a subset of hypovolaemic shock in which there is minimal to massive loss of blood either internally or externally in trauma or injured patients. Data from the World Health Organization (WHO) affirm that injuries account for over 5 million fatalities globally every year, and by 2030, injury mortality is predicted to rise severely. Public health research typically uses the KAP models, which may be divided into three parts: acquiring accurate knowledge, forming an attitude, and adopting behavior, to analyze people’s health behaviors and explain changes in them. This review is about the nurses’ perspectives of the concept of Knowledge, Attitude, and Practice (KAP) Model of hemorrhagic shock in trauma patients and assesses clinical practice tools used by nurses to keep an eye on patients who have the condition. Nurses’ knowledge of indications of shock is either high or very high. The knowledge of nurses was related to their training before working in accident and emergency units. The nurses’ attitude is considered significant, commendable, appropriate, and pertinent to the provision of care for a patient experiencing hemorrhagic shock. And the nurse’s practice of early patient identification, prompt and continuous monitoring, control of the bleeding source, maintenance of hemostasis, and the correction of significant blood loss that can occur quickly to cause death, are the strengths of management. .

C-reactive Protein/Albumin Ratio as a Prognostic Indicator in Posttraumatic Shock and Outcome of Multiple Trauma Patients

Objective C-reactive protein(CRP)/albumin ratio(CAR)is a new inflammation-based index for predicting the prognosis of various diseases.The CAR determined on admission may help to predict the prognostic value of multiple trauma patients.Methods A total of 264 adult patients with severe multiple trauma were included for the present retrospective study,together with the collection of relevant clinical and laboratory data.CAR,CRP,albumin,shock index and ISS were incorporated into the prognostic model,and the receiver operating characteristic(ROC)curve was drawn.Then,the shock index for patients with different levels of CAR was analyzed.Finally,univariate and multivariate logistic regression analyses were performed to identify the independent risk factors for the 28-day mortality of multiple trauma patients.Results A total of 36 patients had poor survival outcomes,and the mortality rate reached 13.6%.Furthermore,after analyzing the shock index for patients with different levels of CAR,it was revealed that the shock index was significantly higher when CAR was≥4,when compared to CAR<2 and 2≤CAR<4,in multiple trauma patients.The multivariate logistic analysis helped to identify the independent association between the variables CAR(P=0.029)and shock index(P=0.019),and the 28-day mortality of multiple trauma patients.Conclusion CAR is higher in patients with severe multiple trauma.Furthermore,CAR serves as a risk factor for independently predicting the 28-day mortality of multiple trauma patients.The shock index was significantly higher when CAR was≥4 in multiple trauma patients.

Wearable Smart Sensor System for Medical Monitoring with an Assessment of the Level of Blood Loss and Pain Shock Because of Trauma or Injury

Blood loss in peacetime is mainly due to the normal menstrual cycle in women or diseases with surgical intervention. In wartime, blood loss in military personnel is a characteristic sign of a closed or open injury of the body during internal or external bleeding. Access to clinical care for wounded military personnel injured on the battlefield is limited and has long delays compared to patients in peacetime. Most of the deaths of wounded military personnel on the battlefield occur within the first hour after being wounded. The most common causes are delay in providing medical care, loss of time for diagnosis, delay in stabilization of pain shock and large blood loss. Some help in overcoming these problems is provided by the data in the individual capsule, which each soldier of the modern army possesses;however, data in an individual capsule is not sufficient to provide emergency medical care in field and hospital conditions. This paper considers a project for development of a smart real-time monitoring wearable system for blood loss and level of shock stress in wounded persons on the battlefield, which provides medical staff in field and hospital conditions with the necessary information to give timely medical care. Although the hospital will require additional information, the basic information about the victims will already be known before he enters the hospital. It is important to emphasize that the key term in this approach is monitoring. It is tracking, and not a one-time measurement of indicators, that is crucial in a valid definition of bleeding.

Clinical Effects of Intensive Insulin Therapy Treating Traumatic Shock Combined with Multiple Organ Dysfunction Syndrome

The therapeutic effects of intensive insulin therapy in treatment of traumatic shock combined with multiple organ dysfunction syndrome （MODS） were investigated. A total of 114 patients with traumatic shock combined with MODS were randomly divided into two groups： control group （n=56） treated with conventional therapy, and intensive insulin therapy group （n=58） treated with conventional therapy plus continuous insulin pumping to control the blood glucose level at range of 4.4-6.1 mmol/L. White blood cells （WBC） counts, prothrombin time （PT）, serum creatinine （SCr）, alanine aminotransferase （ALT）, serum albumin and PaO2 were measured before and at the day 1, 3, 5, 7 and 14 after treatment. The incidence of gastrointestinal dysfunction, the incidence of MODS, hospital stay and the mortality were also observed and compared. After intensive insulin therapy, the WBC counts, SCr, ALT and PT were significantly reduced （P0.05）, but the level of serum albumin was significantly increased （P0.05） at the day 3, 5, 7 and 14. In the meantime, the PaO2 was significantly elevated at the day 3, 5 and 7 （P0.01） after intensive insulin therapy. The incidence of gastrointestinal dysfunction, the incidence of MODS, the length of hospital stay and the mortality were markedly decreased （P0.01）. The results suggest early treatment with intensive insulin therapy is effective for traumatic shock combined with MODS and can decrease the length of hospital stay and the mortality.

Hypopituitary syndrome with pituitary crisis in a patient with traumatic shock:A case report

BACKGROUND Shock is among the most common conditions that clinicians face in intensive care unit(ICU),of which hypovolemic shock is encountered most frequently;some patients instead suffer from neurogenic,cardiogenic,or infectious forms of shock.However,there are additional types of shock from unusual causes that are often undiagnosed.Here,we report the case of a patient who was initially misdiagnosed with hypovolemic shock,but exhibited persistent hypotension because of continuous fluid replacement and vasoactive drug administration,and was eventually diagnosed with hypopituitarism with crisis.CASE SUMMARY A 73-year-old Chinese man was admitted to the neurosurgery department following injury caused by a heavy object with symptoms of anemia and high fever.He was transferred to the ICU on the fourth day after hospitalization because of hypotension and unconsciousness.Blood analysis indicated that the patient was suffering from anemia and thrombocytopenia.Ultrasonography showed that there was no apparent abnormality in the cardiac structure but there was mild tricuspid regurgitation.Computed tomography revealed that there were signs of hemorrhage at the right basal ganglia;accordingly,hypovolemic shock,possibly septic shock,was initially considered.Even after routine treatment for shock,the hypotension remained severe.The patient was again thoroughly examined to investigate the underlying cause.The antishock therapy was supplemented with corticosteroids to counter potential hypopituitarism.The patient made a full recovery,and the blood pressure returned to normal.CONCLUSION A case of pituitary adenoma with multiple injuries was identified.Because of hypopituitarism,functionality of the corresponding endocrine system was restricted,with the most pronounced manifestation being unstable blood circulation requiring hormone replacement therapy.Such cases are relatively rare but may occur if multiple injuries are sustained.The present case represents a reference for the clinical treatment of patients with multiple injuries.

Correlation between heat shock protein 70 expression in the brain stem and sudden death after experimental traumatic brain injury

Objective:Theaimof thisstudywas to determinethepatternsof heat-shockprotein70(HSP 70 )biosynthesis followingtraumaticbraininjury,andobservetheeffectof HSP 70 inductionon thefunctionof thevitalcenterinthebrain stem.Methods:Ratmodelsof suddendeathresultedformtraumaticbraininjurywereproduced,andHSP 70 expressionin theratbrainstemwasdeterminedby immunohistochemistry,theinductionof HSP 70 mRNAdetectedby RT-PCR.Re -sults: Thelevelof HSP 70 mRNAwasprominentlyelevatedinthebrainstemas earlyas15minfollowingtheimpactin-jury,whileHSP 70 expressionwasonlyobserved3to6h aftertheinjury.Itwasalsoobservedthatthelevelsof HSP 70 mR-NAbutnottheproteinwereelevatedinthebrainstemof suddendeathrats.Conclusion:Thesynthesisof HSP 70 wassig-nificantlyenhancedinthebrainstemfollowingtraumaticinjury,andtheexpressionof HSP 70 is beneficialto eliminatethe stressagents,andto sustainthecellularproteinhomeostasis.Whentheinjurydisturbsthesynthesisof HSP 70 to disarmthe protectivemechanismof heat-shockproteins,dysfunctionof thevitalcenterinthebrainstem,andconsequentlydeathmay occur.Breachinthesynchronizationof HSP 70 mRNA-proteincanbeindicativeof fataldamageto thenervecells.

Regulatory mechanisms,prophylaxis and treatment of vascular leakage following severe trauma and shock

Vascular leakage, or increased vascular permeability, is a common but important pathological process for various critical diseases, including severe trauma, shock, sepsis, and multiple organ dysfunction syndrome(MODS), and has become one of the most important causes of death for intensive care units(ICU) patients. Currently, although there has been some progress in knowledge of the pathogenesis of these vascular disorders, the detailed mechanisms remain unclear, and effective prophylaxis and treatment are still lacking. In this study, we aimed to provide a review of the literature regarding the regulatory mechanisms and prophylaxis as well as the treatment of vascular leakage in critical diseases such as severe trauma and shock, which could be beneficial for the overall clinical treatment of vascular leakage disorders.

Bedside diagnosis of hemoperitoneum by characteristics of fluid visualized on focused assessment with sonography in trauma exam in a patient in non-traumatic shock

Dear editor,Focused Assessment with Sonography in Trauma(FAST)enables clinicians to identify injury at the bedside in patients who are too unstable for computed tomography(CT).FAST is most commonly used for the evaluation of trauma,but is also essential to evaluate undifferentiated shock,as in the Rapid Ultrasound for Shock and Hypotension(RUSH)exam.[1]

Pelvic fractures in blunt trauma patients:A comparative study

BACKGROUND Pelvic fractures(PF)with concomitant injuries are on the rise due to an increase of high-energy trauma.Increase of the elderly population with age related comorbidities further complicates the management.Abdominal organ injuries are kindred with PF due to the proximity to pelvic bones.Presence of contrast blush(CB)on computed tomography in patients with PF is considered a sign of active bleeding,however,its clinical significance and association with outcomes is debatable.AIM To analyze polytrauma patients with PF with a focus on the geriatric population,co-injuries and the value of contrast blush.METHODS This retrospective cohort study included 558 patients with PF admitted to level 1 trauma center(01/2017-01/2023).Analyzed variables included:Age,sex,mechanism of injury(MOI),injury severity score(ISS),Glasgow coma scale(GCS),abbreviated injury scale(AIS),co-injuries,transfusion requirements,pelvic angiography,embolization,laparotomy,orthopedic pelvic surgery,intensive care unit and hospital lengths of stay,discharge disposition and mortality.The study compared geriatric and non-geriatric patients,patients with and without CB and abdominal co-injuries.Propensity score matching was implemented in comparison groups.RESULTS PF comprised 4%of all trauma admissions.89 patients had CB.286(52%)patients had concomitant injuries including 93(17%)patients with abdominal co-injuries.Geriatric patients compared to non-geriatric had more falls as MOI,lower ISS and AIS pelvis,higher GCS,less abdominal co-injuries,similar CB and angio-embolization rates,less orthopedic pelvic surgeries,shorter lengths of stay and higher mortality.After propensity matching,orthopedic pelvic surgery rates remained lower(8%vs 19%,P<0.001),hospital length of stay shorter,and mortality higher(13%vs 4%,P<0.001)in geriatric patients.Out of 89 patients with CB,45(51%)were embolized.After propensity matching,patients with CB compared to without CB had more pelvic angiography(71%vs 12%,P<0.001),higher embolization rates(64%vs 22%,P=0.02)and comparable mortality.CONCLUSION Half of the patients with PF had concomitant co-injuries,including abdominal co-injuries in 17%.Similarly injured geriatric patients had higher mortality.Half of the patients with CB required an embolization.

Effect of abdominal trauma on hemorrhagic shock-induced acute lung injury in rats

瞄准：在老鼠在出血性的导致吃惊的尖锐的肺损害上评估腹的损伤的效果。方法：五个组被分配(n = 8 ) 在学习。我作为控制组，被带的组作为出血性的吃惊组，组织 II 是的组 III 出血性的吃惊 + 剖腹术，是的组 IV 是的出血性的吃惊 + 脾切除术和组 V 脾切除术 + 网膜切除术 + 出血性的吃惊组。出血性的吃惊被拉血并且在 10 min 以内把吝啬的动脉压(地图) 归结为 40 毫米汞柱导致。在 1 h 的一个低血压患者时期以后，动物被复活。Bronchoalveolar 洗室年龄(BAL ) 被执行在复活 malondialdehyde (MDA ) 以后与 BAL 液体的 40 mL 从牙槽的空间恢复房间， L-gamma-glutamyl-L-cysteinyl-glycine (GSH ) 层次在浆液，红血球和肺织物被测量。结果：浆液，红血球，肺织物 MDA 和 GSH 层次显著地在出血性的吃惊组 II-V 被增加(P 【 0.05 ) 。在 BAL 液体的淋巴细胞， neutrophil 和牙槽的巨噬细胞计数显示了在控制和吃惊组之间的有效差量(P 【 0.05 ) 。结论：损伤的度增加出血性的导致吃惊的尖锐的肺损害。

Study on cumulative effects of biological craniocerebral trauma under repeated blast

Repeated blast impacts on personnel in explosive environments can exacerbate craniocerebral trauma.Most existing studies focus on the injury effects of a single blast,lacking in-depth analysis on the injury effects and cumulative effects of repeated blasts.Therefore,rats were used as the experimental samples to suffer from explosion blasts with different peak air overpressures(167 kPa~482 kPa)and varying number of repeated blasts.The cumulative effect of craniocerebral trauma was most pronounced for moderate repeated blast,showing approximately 95%increase of trauma severity with penta blast,and an approximately 85%increase of trauma severity with penta minor blast.The cumulative effect of craniocerebral trauma from severe,repeated blast has a smaller rate of change compared to the other two conditions.The severity of trauma from penta blast increased by approximately 69%compared to a single blast.Comprehensive physiological,pathological and biochemical analysis show that the degree of neurological trauma caused by repeated blasts is higher than that of single blasts,and the pathological trauma to brain tissue is more extensive and severe.The trauma degree remains unchanged after double blast,increases by one grade after triple or quadruple blast,and increases by two grades after penta blast.

Can albumin administration relieve lung injury in trauma/hemorrhagic shock?

AIM: To study the effect of albumin administration on lung injury in trauma/hemorrhagic shock (T/HS). METHODS: Sixty experimental animals were randomly divided into three groups: rats undergoing laparotomy without shock (T/SS); rats with T/HS and resuscitation with blood plus twice the volume of shed blood as Ringer’s lactate (RL), and rats with T/HS and resuscitation with blood plus additional 3 mL of 50 g/L human albumin. Expression of polymorphonuclear neutrophil (PMN) CD11b/CD18, intercellular adhesion molecule-1 (ICAM-1) of jugular vein blood and the severity of lung injuries [determined mainly by measuring activity of lung tissue myeloperoxidase (MPO) and lung injury score (LIS)] were measured after a 3-h recovery period. RESULTS: All three groups showed a significant difference in the expressions of CD11b/CD18, ICAM-1, and severity of lung injury. The expressions of CD11b/ CD18 in T/SS group, T/HS + RL group, T/HS + albumin group were 17.76% ± 2.11%, 31.25% ± 3.48%, 20.36% ± 3.21%, respectively (F = 6.25, P < 0.05). The expressions of ICAM-1 (U/mL) in T/SS group, T/ HS + RL group, T/HS + albumin group were 258.76 ± 98.23, 356.23 ± 65.6, 301.01 ± 63.21, respectively (F = 5.86, P < 0.05). The expressions of MPO (U/g) in T/SS group, T/HS + RL group, T/HS + albumin group were 2.53 ± 0.11, 4.63 ± 1.31, 4.26 ± 1.12, respectively (F = 6.26, P < 0.05). Moreover, LIS in T/HS + RL group, T/HS + albumin group was 2.62 ± 0.23, 1.25 ± 0.24, respectively. The expressions of CD11b/CD18, ICAM-1 and MPO in T/HS + RL group were significantly increased compared to T/SS group (P = 0.025, P = 0.036, P = 0.028,respectively). However, administration of 3 mL of 50 g/L albumin significantly down-regulated the expressions of CD11b/CD18, ICAM-1 and lung injury index (MPO and LIS) when compared with the T/HS + RL rats (P = 0.035, P = 0.046, P = 0.038, P = 0.012, respectively). CONCLUSION: The infusion of albumin during resuscitation period can protect lung from injury and decrease the expressions of CD11b/CD18, ICAM-1 in T/ HS rats.

Effect of preoperative limited fluid resuscitation to the patients with traumatic shock

Objective:To investigate the effect of preoperative limited fluid resuscitation on the patients with traumatic shock.Methods:Eighty-nine patients with multiple injuries complicating with shock were treated in Changhai Hospital between January 2002 to October 2005 and were divided into 3 groups accord ing to the preoperative levels of systolic blood pressure(SBP).SBP of group A and group B were about 70 and 80 mmHg,respectively;and the SBP of group C was over 90 mmHg.Results:(1)There was no sig- nificant difference in age,gender,and injury severity score(ISS),initiated resuscitation time and initiated operation time among the 3 groups.Preoperatively,there was significant difference in the amount of fluid resuscitation and infused erythrocyte suspension among group A,B and C(1687±96 ml,2096±87 ml. 2976±93 ml,P<0.05;and 294±110ml,404±113 ml,7984±230ml,P<0.05).(2)The hemoglobin level in group C(94±45 g/L)was lower than that in group A(110±22 g/L)and group B(103±24 g/L)(P<0.05).However,there was no significant difference in the level of hemoglobin between group A and B.(3)There was no significant difference in the incidence of acute renal failure(ARF)among the 3 groups.The incidence of acute respiratory distress syndrome(ARDS)of group C(31.2%)was higher than that of group A(16.7%)and group B(18.2%)(P<0.05).The mortality of group C(34.4%)was higher than that of group A(12.5%)and group B(12.1%)(P<0.05).Conclusion:Preoperative limited resuscitation applied on patients with traumatic shock can reduce blood loss,incidence of ARDS and mor tality.

Albumin resuscitation protects against traumatic/hemorrhagic shock-induced lung apoptosis in rats

Objective: To determine the effects of albumin administration on lung injury and apoptosis in traumatic/hemorrhagic shock (T/HS) rats. Methods: Studies were performed on an in vivo model of spontaneously breathing rats with induced T/HS; the rats were subjected to femur fracture, ischemia for 30 min, and reperfusion for 20 min with Ringer's lactate solution (RS) or 5% (w/v) albumin (ALB), and the left lower lobes of the lungs were resected. Results: Albumin administered during reperfusion markedly attenuated injury of the lung and decreased the concentration of lactic acid and the number of in situ TdT-mediated dUTP nick-end labelling (TUNEL)-positive cells. Moreover, immunohistochemistry performed 24 h after reperfusion revealed increases in the level of nuclear factor κB (NF-κB), and phosphorylated p38 mitogen-activated protein kinase (MAPK) in the albumin-untreated group was down-regulated by albumin treatment when compared with the sham rats. Conclusion: Resuscitation with albumin attenuates tissue injury and inhibits T/HS-induced apoptosis in the lung via the p38 MAPK signal transduction pathway that functions to stimulate the activation of NF-κB.

Trauma to the solid abdominal organs:The missed dark box of colonoscopy

Colonoscopy is an integral part of the lower bowel care and is generally considered a potentially safe diagnostic and therapeutic procedure performed as a daycare outpatient procedure.Colonoscopy is associated with different complications that are not limited to adverse events related to the bowel preparation solutions used,the sedatives used,but to the procedure related as well including bleeding and perforation.Injuries to the extra-luminal abdominal organs during colonoscopy are uncommon,however,serious complications related to the procedure have been reported infrequently in the literature.Life threatening injuries to the spleen,liver,pancreas,mesentery,and urinary bladder have been reported as early as in mid-1970s.These injuries should not be overlooked by clinicians and endoscopists.Steadily increasing abdominal pain,abdominal distension,and hemodynamic instability in absence of rectal bleeding should raise the possibility of severe organ injury.Splenic and hepatic injury following colonoscopy are usually serious and may be life threatening.Although conservative management may help,yet they usually need interventional radiology or surgical intervention.Acute pancreatitis following colonoscopy is usually mild and is mostly managed conservatively.The mechanism of abdominal organ injuries during colonoscopy is not fully understood,however many risk factors have been identified,which can be classified as-organ related,procedure related,and local abdominal factors.Difficult colonoscopy and prior intra-abdominal adhesions are probably the most relevant risk factors for these injuries.Left lateral position,avoidance of looping and excessive force during the procedure would probably reduce the risk of such injuries.

Strong shock propagation for the finite-source circular blast in a confined domain

The circular explosion wave produced by the abrupt discharge of gas from a high-temperature heat source serves as a crucial model for addressing explosion phenomena in compressible flow.The reflection of the primary shock and its propagation within a confined domain are studied both theoretically and numerically in this research.Under the assumption of strong shock,the scaling law governing propagation of the main shock is proposed.The dimensionless frequency of reflected shock propagation is associated with the confined distance.The numerical simulation for the circular explosion problem in a confined domain is performed for validation.Under the influence of confinement,the principal shock wave systematically undergoes reflection within the domain until it weakens,leading to the non-monotonic attenuation of kinetic energy in the explosion fireball and periodic oscillations of the fireball volume with a certain frequency.The simulation results indicate that the frequency of kinetic energy attenuation and the volume oscillation of the explosive fireball align consistently with the scaling law.

Cranial ultrasound in perioperative period of acute severe traumatic brain injury

Objective To observe the value of cranial ultrasound for perioperative patients with acute severe traumatic brain injury(sTBI).Methods Data of 55 sTBI patients who underwent craniotomy were retrospectively analyzed.The patients were divided into observation group(n=15)and control group(n=40)according to received perioperative cranial ultrasound or not.The general data and surgical data were compared between groups,and ultrasonic data of observation group were analyzed.Results The proportions of good prognosis 1 and 6 months after operation in observation group were both higher than those in control group,while the incidence of cerebral infarction in observation group was lower than that in control group(all P<0.05).No significant difference of general data nor other surgical data was found between groups(all P>0.05).Acute encephalocele occurred in 1 case in observation group during operation,and cranial ultrasound accurately showed the contralateral secondary epidural hematoma.Increased intracranial pressure in different degrees were found in all 15 cases(15/15,100%)in observation group after operation with transcranial color coded Doppler(TCCD)or transcranial Doppler(TCD),while cerebral vascular spasm was observed in 5 cases(5/15,33.33%),among them 4 cases(4/5,80.00%)were diagnosed cerebral infarction based on CT examination.Conclusion Cranial ultrasound could be used to evaluate changes of sTBI in perioperative period and guide adjusting treatment strategy in time,being valuable for reducing risk of postoperative cerebral infarction and improving prognosis.

Experimental and numerical study on protective effect of RC blast wall against air shock wave

Prototype experiments were carried out on the explosion-proof performance of the RC blast wall.The mass of TNT detonated in the experiments is 5 kg and 20 kg respectively.The shock wave overpressure was tested in different regions.The above experiments were numerically simulated,and the simulated shock wave overpressure waveforms were compared with that tested and given by CONWEP program.The results show that the numerically simulated waveform is slightly different from the test waveform,but similar to CONWEP waveform.Through dimensional analysis and numerical simulation under different working conditions,the equation for the attenuation rate of the diffraction overpressure behind the blast wall was obtained.According to the corresponding standards,the degree of casualties and the damage degree of the brick concrete building at a certain distance behind the wall can be determined when parameters are set.The above results can provide a reference for the design and construction of the reinforced concrete blast wall.