Severe Crush Research Articles

Carbon nanoarchitecture encapsulated highly dispersed ultrafine Ag particles composite anode for high-capacity desalination

The high capacity of silver (Ag) anodes positions them as a promising avenue for addressing pressing water purification challenges through capacitive deionization (CDI). However, it faces significant challenges such as severe volume expansion and particle crushing, leading to rapid electrochemical failure. Herein, hierarchical hybrid structures comprising highly dispersed ultrafine Ag anchored in carbon nanolayers were prepared using a temperature-mediated strategy. The coordination effect of organic precursors reduces the surface energy of Ag nanoparticles, effectively preventing aggregation during heat treatment. Carbon layer encapsulation synergized with particle size control effectively suppresses the absolute volumetric strain of the electrode in the electrochemical reaction, enhancing electrochemical stability. When used as a CDI anode, AgNC-500 demonstrated an excellent Cl- capturing capacity of 159.96 mg g-1 and a rate of 27.53 mg g−1 min−1. Furthermore, the capacity exhibited excellent stability with negligible degradation over 50 cycles. This study offers crucial insights for advancing the development of highly stable conversion electrodes.

Cardiovascular events in crush syndrome: on-site therapeutic strategies and pharmacological investigations.

Crush syndrome often occurs after severe crush injury caused by disasters or accidents, and is associated with high mortality and poor prognosis. Cardiovascular complications, such as cardiac arrest, hypovolemic shock, and hyperkalemia-related cardiac dysfunction, are the primary causes of on-site death in crush syndrome. Prehospital evaluation, together with timely and correct treatment, is of great benefit to crush syndrome patients, which is difficult in most cases due to limited conditions. Based on current data and studies, early fluid resuscitation remains the most important on-site treatment for crush syndrome. Novel solutions and drugs used in fluid resuscitation have been investigated for their effectiveness and benefits. Several drugs have proven effective for the prevention or treatment of cardiovascular complications in crush syndrome, such as hypovolemic shock, hyperkalemia-induced cardiac complications, myocardial ischemia/reperfusion injury, ventricular dysfunction, and coagulation disorder experimentally. Moreover, these drugs are beneficial for other complications of crush syndrome, such as renal dysfunction. In this review, we will summarize the existing on-site treatments for crush syndrome and discuss the potential pharmacological interventions for cardiovascular complications to provide clues for clinical therapy of crush syndrome.

Pediatric crush-related acute kidney injury and risk factors: asingle center experience.

Crush injury, the most important trauma complicationencountered in earthquake victims, occurs as a result of prolonged compression of muscle mass. Crush syndrome, resultingfrom crushinjury, and acute kidney injury (AKI) are the most common causes of in-hospital deaths after earthquakes. The aim of this study is to convey our experience afterthe devastating Turkey-Syria earthquake and to identify the risk factors of crush syndrome and crush-related AKI. Of the 1134 children admitted to the emergency department, 265 with crush injury were included the study. Demographic information, laboratory and clinical data of the patients were retrospectively analyzed. Mean age of the patientswas 10.3 ± 4.9years (134 femalesand131 males). The median time spent under the rubble was 20h. Crush syndrome developed in 135 (50.9%). Patients with crush syndrome were older and had higher body weight, respectively (p = 0.014, p = 0.044). Acute kidney injury was present in 157 (59.2%) patients. Thirty-two patients (12.1%) received kidney replacement therapy (KRT). The risk factors for the development of AKI Stage 3 were crush syndrome, abdominal trauma, and age. This disaster taught us the importance of establishing in advancea national emergency disaster plan. Older pediatric earthquake victims with multiple trauma and severe crush syndrome should be closely followed-up for development of AKI and, if necessary, started on dialysis. Timely access to medical care, early fluid resuscitation, and effective use of dialysis treatment are essential.

A systematic review and meta-analysis of complications associated with crushed cartilage in rhinoplasty

BackgroundCrushed cartilage grafts improve augmentation and contour irregularities in rhinoplasty; however, they are associated with complications including resorption, asymmetries, palpability, and need for revisionary surgery. MethodsA systematic review and meta-analysis using PRISMA guidelines was performed of all recorded history to November 2022 using the search query ("crush" or "crushed") AND cartilage AND rhinoplasty for the PubMed, World of Science, Embase, and Cochrane online registries. Data was collected on study information, patient demographics, surgical details and outcomes. Graft resorption and revision surgery were pooled in a random-effects model, and a subgroup analysis for different coverage of the cartilage and degree of crushing. ResultsThe initial search yielded 163 results with 11 studies included in final full text review. A total of 1,132 patients were analyzed with 456 (40.3%) females, mean age 48.0, and average follow-up of 24.9 months. Cartilage resorption rates were statistically higher in graft preparation with severe crushing (3.4%) compared to non-severe crushed (0.9%) (p=0.049). There was no significant difference in resorption rate for patients with covered cartilage graft (1.3%) compared to non-covered grafts (1.8%) (p=0.7). There were significantly more revision surgeries for severely crushed (17.9%) compared to non-severely crushed cartilage (3.5%) (p=0.003). ConclusionsSevere crushed cartilage grafting provides smooth contour and less palpability compared to other degrees of crushing but demonstrates significantly higher rate of resorption.

Morphological characteristics and reduction techniques of sagittal beak-like deformity of head-neck fragment in femoral intertrochanteric fractures

To summarize the morphological characteristics of sagittal beak-like deformity of head-neck fragment in femoral intertrochanteric fractures and to investigate the technical skills in fracture reduction. A clinical data of 31 patients with femoral intertrochanteric fractures between May 2021 and April 2023 was retrospectively analyzed. The fractures had sagittal beak-like deformity of head-neck fragment in all patients. There were 13 males and 18 females, with an average age of 76.2 years (range, 68-83 years). The time from injury to operation was 36-76 hours (mean, 51.2 hours). Fractures were classified as type A1.2 in 10 cases, type A1.3 in 11 cases, type A2.2 in 6 cases, and type A2.3 in 4 cases according to the AO/Orthopaedic Trauma Association (AO/OTA)-2018 classification; and as type A1.3 in 10 cases, type A2.1 in 11 cases, type A2.2 in 6 cases, type A2.3 in 2 cases, and type A2.4 in 2 cases according to a novel comprehensive classification for femoral intertrochanteric fractures proposed by the "Elderly Hip Fracture" Research Group of the Reparative and Reconstructive Surgery Committee of the Chinese Rehabilitation Medical Association. Based on preoperative X-ray films, CT scan and three-dimensional reconstruction, the fractures were classified into two types: type 1 (14 cases), with uncomplicated fracture morphology, severe bone interlocking and (or) soft tissue incarceration; type 2 (17 cases), with severe fracture crushing, obvious dissociation between bone blocks, and severe soft tissue hinge destruction. After the failure of the closed reduction, all patients underwent fracture reduction assisted with instrument via anterior minimal incision and proximal femoral nail antirotation nails internal fixation. The operation time, intraoperative fluoroscopy, intraoperative visible blood loss, length of hospital stay, and incidence of complications were recorded. The fracture reduction quality and stability score were assessed at immediate after operation under fluoroscopy. The fracture healing was evaluated and healing time was recorded by X-ray films. The pain visual analogue scale (VAS) score was performed at 48 hours after operation and Parker-Palmer activity score at 3 months after operation for function evaluation. The operation time was 39-58 minutes (mean, 46.3 minutes); fluoroscopy was performed 13-38 times (mean, 23.5 times) during operation; the intraoperative visible blood loss was 45-90 mL (mean, 65.3 mL). The fracture reduction quality and stability score were rated as good in 29 cases and acceptable in 2 cases. The pain VAS score was 2-6 (mean, 3.1) at 48 hours after operation. Eleven patients developed deep vein thrombosis of the lower limbs after operation. Patients were hospitalized for 6-10 days (mean, 7.3 days). All patients were followed up 5-8 months (mean, 6.5 months). All fractures healed at 3.5-8.0 months after operation (mean, 4.5 months). Parker-Palmer activity score at 3 months after operation was 9 in 28 cases and 6 in 3 cases. The femoral intertrochanteric fracture with sagittal beak-like deformity of head-neck fragment is difficult to manually reduce. The pin combined with cannulated screw insertion to the neck cortex can hold the fragment and assist fracture reduction, which is a simple and effective technique.

Successful salvage of upper extremity following severe crush injury associated with vascular compromise using a supra thin free anterolateral thigh flap

Traumatic injuries of the upper limbs can often result in serious and challenging wounds involving multiple compartments such as skin, bone, tendons and neurovascular structures. These type of injuries of the upper extremity pose several challenges to the plastic surgeon. The main difficulty is to provide a stable, long lasting and aesthetically acceptable coverage that enables joints excursion so that patient can return to work at the earliest. Here, we present a case of 45 years old gentlemen who sustained severe crush injury associated with avulsed radial and ulnar artery of left upper limb following road traffic accident. At presentation, there was no pin prick in his hand and hand was pale. At first surgery, hand was revascularized using a vein graft in radial artery and skin grafting was done over the forearm defect as a temporary cover. After 12 hours, when the viability of hand was reassured, the defect was covered with free supra thin anterolateral thigh (ALT) flap. Patient’s hand and flap both survived and he was discharged in a satisfactory condition.

Adenocarcinoma originating in the anterior mediastinum diagnosed by endobronchial ultrasound-guided transbronchial cryobiopsy: a case report

BackgroundEndobronchial ultrasound-guided transbronchial cryobiopsy (EBUS-cryobiopsy) is advantageous for collecting larger specimens with minimal crushing; however, it has not been widely used for mediastinal tumors.Case presentationA 73-year-old woman with a history of left breast cancer underwent surgery followed by radiotherapy. Computed tomography showed a mass in the anterior mediastinum that was in extensive contact with the sternum on the ventral side and partly with the trachea on the dorsal side. Two computed tomography-guided needle biopsies (CTNBs) were performed on the mass; however, a definitive diagnosis was not made because of severe crush artifacts. Subsequently, we performed EBUS-cryobiopsy and safely obtained sufficient specimen volume with minimal crushing. The histopathological diagnosis was adenocarcinoma, with immunobiological features distinct from those of previous breast cancers. Her overall diagnosis was a rare tumor originating in the anterior mediastinum.ConclusionsEBUS-cryobiopsy can be safely performed in narrow areas surrounded by major blood vessels, and the obtained specimens may be superior to CTNBs for histopathological diagnosis.

6 Şubat 2023 Kahramanmaraş’ta Yaşanan Büyük Deprem Sonrasında Kriz Yönetimi ve Ampütasyon Kararlarından Alınan Dersler

Background:Earthquakes of high magnitude and prolonged duration result in catastrophic events, causing significant human and material losses. Immediate medical interventions become crucial in the aftermath of such disasters to prevent long-term disabilities and fatalities. This study focuses on the challenges faced by a volunteer medical team in Kahramanmaras, Turkey, after two major earthquakes struck on February 6, 2023, affecting millions of people. Methods:A team of 35 experienced medical professionals, led by a cardiothoracic surgeon, was dispatched to the disaster site. The team's schedule, tasks, and logistical details were organized to optimize their response. The study outlines the methods employed by the team to assess and treat extremity traumas, including amputations, during the first-week post-earthquake. Results:The earthquake severely impacted local healthcare facilities, resulting in inadequate patient management, insufficient medical personnel, and logistical difficulties. The volunteer team worked tirelessly, performing surgeries and amputations and providing medical equipment. A total of 16 lower limb amputations and two upper limb amputations were performed due to severe extremity crush injuries. Discussion:The chaotic conditions post-earthquake revealed challenges in managing crush syndrome patients. The study discusses the decision-making process for amputations, fasciotomies, and patient transfers. Despite limited facilities, the team restored the hospital to full functionality within a few days. Conclusion:The study concludes that volunteer healthcare teams are crucial in disaster response. Effective organization, communication, and logistics are essential for optimal performance. Continuous training on disaster scenarios for volunteer teams is recommended. The importance of restoring healthcare facilities to routine operation after immediate crisis response is emphasized, as well as the need for comprehensive scientific data to understand the extent of the disaster's impact.

Use of Negative Pressure Wound Therapy in the Management of Extreme Crush Abdominopelvic Injuries: An In-Depth Case Study and Literature Review

Background. Negative pressure wound therapy (NPWT) has significantly transformed wound care, particularly the management of complex injuries and unresponsive wounds. Crush injuries from road traffic accidents pose intricate challenges due to their severity, often requiring multimodal interventions. NPWT accelerates healing by stimulating tissue formation and reducing inflammation; however, its use necessitates careful patient selection and wound assessment for potential complications. Case Report. A 16-year-old male sustained catastrophic crush injuries involving extensive soft tissue damage, bone exposure, bowel perforation, and genitourinary trauma in a vehicular accident involving a farm vehicle run-over event. The patient received various interventions, including NPWT combined with tension sutures for wound management. The case highlights the multidisciplinary approach required to manage primary wounds and complications. NPWT facilitated granulation tissue formation, aiding wound closure without necessitating alternative methods such as skin grafting or flap coverage. Conclusion. This case underscores NPWT's effectiveness in the management of severe crush injuries. While successful wound closure was achieved, as of this writing postoperative-recovery challenges persist, emphasizing the importance of multidisciplinary care in long-term recovery. The case reaffirms NPWT as a valuable option in managing extensive injuries resulting from road traffic accidents.

Neo-Forearm Functional Reconstruction after Temporary Ectopic Hand Implantation for Salvage of Hand after Extensive Crush Injury to Forearm

Abstract Background Extensive crush injuries to forearm pose a unique problem where replantation of uninjured hands to the forearm is not immediately possible due to difficulties in delineating tissue necrosis. Ectopic hand implantation preserves the hand and allows replanting the hand back to the forearm stump, but the tissues preserved in the stump could be inadequate to provide good hand function. In these subsets of cases, forearm reconstruction with composite flaps may offer a better chance of getting good hand function. Methods We present a case of a 29-year-old male, a left-handed factory worker, with severe crushing of the left forearm by a hydraulic pressing machine with a relatively undamaged hand. A three-staged reconstruction was done with the recovery of the left hand after below elbow amputation and replanted to the left lower third of leg. Then a neo-forearm was reconstructed using a functioning free fibula, vastus lateralis muscle, and anterolateral thigh skin flap. Finally, the ectopically banked hand was returned to the reconstructed neo forearm. Results After 2 years follow-up, protective sensation and grip strength of 2 pounds had developed in the hand. The disabilities of arm, shoulder, and hand score was 21, and he was able to perform multiple tasks using the left hand independently and as an assistive hand. Conclusion The consensus on indications of ectopic banking is still open for debate. The addition of our ectopic replantation technique followed by neo-forearm reconstruction and replantation of the hand into the reconstructed neo-forearm, which is a novel concept, will broaden the horizon of reconstructive paradigm.

Injuries Due to Improvised Explosive Devices

Illegal possession of improvised explosive devices (IEDs) is not uncommon. In Sri Lanka, they are commonly used for hunting, protecting cultivation, etc. Further, they are also used to commit homicides. An IED called “Hakka Patas” is produced by the material available in firecrackers and causes pressure-sensitive blasts. Another IED “Ali Wedi”, a kind of larger firecracker, may cause accidental injuries. However, the injuries caused by “Hakka Patas” and “Ali Wedi” are not reported in the forensic literature.Case 1: A child received severe crush injuries of the foot following a “Hakka Patas” explosion while walking. The wound was grossly contaminated and on the second day, a below knee amputation was done. Case 2: A farmer received injuries to his right hand while he was throwing an “Ali Wedi”. Due to gross crush injuries, the right index finger was amputated.Strict rules and regulations should be implemented to control illegal, locally-made explosive devices to prevent morbidity and mortality. Forensic pathologists should be familiar with the atypical patterns of injuries produced by improvised explosive devices.

Numerical Study on Discrete Confinement of Circular RC Column Subjected to Eccentric Load

Background: The performance of concrete-filled steel-tube (CFST) columns under axial compression is excellent. However, the steel-tube wall's instability due to insufficient outward restraint from the concrete made the steel tube lose its lateral support, thereby making it more susceptible to buckling. Objective: This study aims to propose and investigate a confinement mechanism that can remove the possibility of buckling of the steel tube by introducing gaps and pre-tension to prevent tube detachment from concrete. The investigation was carried out using both experimental tests and numerical simulation. Methods: The proposed confinement mechanism consists of thin steel sheets with gaps between them and is pre-tensioned in a staggered scheme. The performance of the proposed confinement mechanism is evaluated through experimental tests and numerical simulations using an in-house 3D-NLFEA package. The observed behaviors are the axial stress-strain, strength index, initial confining pressure, and ductility. Results: Experimental works found that the primary failure mode in the compression zone of the strengthened column was due to lateral expansion of concrete which may be attributed to strain localization, longitudinal tensile cracking, and severe concrete crushing. On the other hand, at the tensile region, pure tensile forces occurred, followed by crack opening displacement at the outer tensile fiber region. With the proposed confinement mechanism, the extreme failure event can be reduced. The axial capacity and ductility of the strengthened column were enhanced. The numerical model presented the initial confining pressure by the pre-tensioned steel sheet (a clamping mechanism), which successfully increased the axial load capacity of the slender reinforced concrete (RC) column and reduced the possibility of cover spalling. Conclusion: The proposed confinement mechanism to strengthen an RC column was found to successfully enhance the load-carrying capacity and ductility of a slender circular reinforced concrete column.

Study on seismic performance of prefabricated shear walls using non-contact lapping with steel fiber reinforced sulphoaluminate concrete connection

The study designed a prefabricated shear wall using non-contact lapping with steel fiber reinforced sulphoaluminate concrete connection, which had many advantages, such as early high-strength, convenient assembly, short construction period, low precision requirement and compact concrete. To investigate the seismic performance of prefabricated reinforced concrete shear wall (PRCSW), pseudo-static tests were conducted on the three PRCSWs with three lapping length of non-contact lapping steel bars (i.e. 100, 200, 300 mm) and one cast-in-place reinforced concrete shear wall (CRCSW). The results showed that the three PRCSWs did not occur the severe crushing of concrete. The crack distribution height of PRCSW could reach the similar height to the CRCSW as the lapping length increased to 300 mm. The shape of hysteresis loops presented anti-S-shape, which illustrated the PRCSWs occurred obvious slip deformation. In comparison with the CRCSW, the peak loads of the PRCSWs with lapping lengths of 100, 200, and 300 mm decreased 22.9%, 13.0% and 11.0%, while the corresponding displacements decreased 30.5%, 19.5%, and 12.4%. As the lapping length ranged in 100 mm–300 mm, the ductility factors of PRCSWs were larger than 3.2, which met the requirement of Chinese code GB50011-2010. The ductility factors of PRCSWs with lapping lengths of 100 and 200 mm decreased by 3.4% and 10.8% compared with CRCSW, but it increased by 10.6% for PRCSW with lapping length of 300 mm. The cumulative energy dissipation of PRCSW with lapping length of 300 mm was 50.9% higher than that of CRCSW. But it decreased by 22.6% and 12.2% for PRCSWs with lapping length of 100 mm and 200 mm. Thus, it could be summarized the bearing capacity, deformation capacity and energy dissipation of PRCSW could be improved by increasing the lapping length. Meanwhile, the PRCSWs could obtain acceptable seismic performance as the lapping length increased to 300 mm. The calculation method on the load bearing capacity was proposed, which had high accuracy by comparison the calculated and tested results of peak loads of PRCSWs.

Temporary hypothyroidism in severe crush syndrome: a potential novel entity.

Thyroid hormone synthesis is a complex process in the human body. Although the thyroid gland is essential for thyroid hormone synthesis, skeletal muscles also have crucial roles in thyroid hormone metabolism due to the deiodinase activities of the muscle cells. Hypothyroidism-related myopathy is a well-known entity. However, systemic effects of acute myopathies, such as rhabdomyolysis, on thyroid hormone metabolism have not to date been fully clarified. Fifty-three earthquake victims were evaluated retrospectively. We investigated the thyroid function tests (TFTs) among patients with creatine kinase (CK) levels higher than 10.000 U/L at admission. Fifteen patients had CK levels higher than 10.000 U/L and 12 of them had data of TFTs, including thyroid stimulating hormone (TSH), free T4 (FT4), and free T3 (FT3) during hospitalization. These patients were evaluated. TSH levels were increased in all seven patients who required HD due to severe crush syndrome. Decreased FT4 levels were detected in 71.4% of them. None of the five non-HD patients had increased TSH levels or reduced FT4 levels. During follow-up, all patients survived. Renal and thyroid functions were normalized during follow-up without thyroxin replacement in patients with no prior history of hypothyroidism. Moreover, TFTs were normalized in two patients with history of hypothyroidism under thyroxine treatment without dose adjustments. In severe forms of crush syndrome, temporary hypothyroidism might be seen. The exact mechanism underlying this entity is not well-known. Further clinical and experimental trials should be conducted to illuminate the mechanism of disrupted thyroid hormonogenesis in crush syndrome victims.

PTEN knockout using retrogradely transported AAVs transiently restores locomotor abilities in both acute and chronic spinal cord injury

Restoring function in chronic stages of spinal cord injury (SCI) has often been met with failure or reduced efficacy when regenerative strategies are delayed past the acute or sub-acute stages of injury. Restoring function in the chronically injured spinal cord remains a critical challenge. We found that a single injection of retrogradely transported adeno-associated viruses (AAVrg) to knockout the phosphatase and tensin homolog protein (PTEN) in chronic SCI can effectively target both damaged and spared axons and transiently restore locomotor functions in near-complete injury models. AAVrg's were injected to deliver cre recombinase and/or a red fluorescent protein (RFP) under the human Synapsin 1 promoter (hSyn1) into the spinal cords of C57BL/6 PTENFloxΔ/Δ mice to knockout PTEN (PTEN-KO) in a severe thoracic SCI crush model at both acute and chronic time points. PTEN-KO improved locomotor abilities in both acute and chronic SCI conditions over a 9-week period. Regardless of whether treatment was initiated at the time of injury (acute), or three months after SCI (chronic), mice with limited hindlimb joint movement gained hindlimb weight support after treatment. Interestingly, functional improvements were not sustained beyond 9 weeks coincident with a loss of RFP reporter-gene expression and a near-complete loss of treatment-associated functional recovery by 6 months post-treatment. Treatment effects were also specific to severely injured mice; animals with weight support at the time of treatment lost function over a 6-month period. Retrograde tracing with Fluorogold revealed viable neurons throughout the motor cortex despite a loss of RFP expression at 9 weeks post-PTEN-KO. However, few Fluorogold labeled neurons were detected within the motor cortex at 6 months post-treatment. BDA labeling from the motor cortex revealed a dense corticospinal tract (CST) bundle in all groups except chronically treated PTEN-KO mice, indicating a potential long-term toxic effect of PTEN-KO to neurons in the motor cortex which was corroborated by a loss of β-tubulin III labeling above the lesion within spinal cords after PTEN-KO. PTEN-KO mice had significantly more β-tubulin III labeled axons within the lesion when treatment was delivered acutely, but not chronically post-SCI. In conclusion, we have found that using AAVrg's to knockout PTEN is an effective manipulation capable of restoring motor functions in chronic SCI and can enhance axon growth of currently unidentified axon populations when delivered acutely after injury. However, the long-term consequences of PTEN-KO on neuronal health and viability should be further explored.

Management of floating arm: a case report.

This study report a 59-year-old man with a rare humeral fracture and a severe crush injury of the forearm. There is a paucity of evidence regarding the management of concomitant floating arm and soft tissue injuries in the literature.The patient was managed by minimally invasive plate osteosynthesis (MIPO) and vacuum-assisted closure (VAC) followed by a split-thickness skin graft. The concurrent presence of the two pathologies exacerbated the patient's condition and made the management challenging. In this case, the authors have used the MIPO approach to fix both fractures with minimal soft tissue injury. To manage the prominent soft tissue injury, we applied the VAC device. VAC has the advantages of reducing edema, controlling bacterial growth, and promoting granulation tissue formation, leading to faster cellular turnover and healing. In patients with floating arm, especially with concomitant soft tissue damage, the MIPO approach is a safe, minimally invasive, and quick method with minimal bleeding.

Research into the Mechanism and Application of Liquid CO2 Phase-Transition Fracturing in a Coal Seam to Enhance Permeability

The geological structures of the coal fields in China are complex. With a continuous increase in the mining depth, the coal seams show the characteristics of high gas and low permeability, and the disaster potential for a coal and gas outburst intensifies in the process of coal mining. Gas drainage is one of the primary measures used to prevent and control gas disasters. Effectively improving the permeability of a coal seam requires urgent attention. Currently, the method of loose blasting is used in engineering to enhance the permeability of coal seams. However, the technology of loose blasting easily leads to the poor development of coal fractures or the severe crushing of coal, which will affect the gas drainage. Thus, this paper studied the technology of liquid CO2 phase-transition fracturing in a coal seam. COMSOL was used to determine the influence radius of the liquid carbon-dioxide phase-transition cracking, which was 13.4 m, and to design the scheme of the borehole. The field test was carried out in the 81,506th working face of the Baode Coal Mine. From the onsite-monitoring data, the results showed that the drainage effect increased by 293.9%, the gas-drainage concentration increased by 242.4%, the permeability coefficient of the coal seam increased by 3–7.75 times, and the permeability enhancement effect was good.

Serial Application of Meshed Collagen-chondroitin Silicone Bilayer Matrix to Obtain Full Coverage over Bone and Tendon in Challenging Situations and Medically Compromised Patients: A Small Case Series

Introduction. Soft tissue defects in medically compromised patients present significant challenges to the reconstructive surgeon, particularly when vital structures are exposed. This case series reports clinical outcomes of 5 adult patients with challenging medical problems whose wounds were managed using a meshed collagen-chondroitin silicone bilayer matrix to obtain coverage over bone and tendon. Materials and Methods. Patient 1 had significant degloving of the scalp. Patient 2, who had a giant neglected tumor, had a defect comprising the entire occipital skull. Patients 3 and 4 had necrotizing infection in a lower extremity open wound and a pretibial wound (patient 3). Patient 5 sustained a severe crush injury of his forearm and had a large open wound. All the wounds had exposed structures. Results. The incorporation rate of the dermal matrix in the wound bed was 100% in patients 1 and 5, 75% in patient 2, and 90% in patients 3 and 4. Patients 2 and 4 received a second application of dermal matrix to obtain full coverage of the wounds. Each patient achieved stable soft tissue coverage and successful reconstruction. Conclusions. These 5 cases highlight the capacity and capability of this dermal matrix to allow coverage over exposed bone and tendon, as well as the clinical utility of the serial application of this matrix.

Multi-Segmental Osteocutaneous Free Fibula Flap for Three-Dimensional Post-Traumatic Thumb and Wrist Reconstruction

Thumb reconstruction following a traumatic injury challenge depends on the extent of the injury. Ideally, reconstruction should restore thumb length and position and retain thumb stability, mobility, and strength, while preserving sensation and aesthetics. Achieving these outcomes can be especially challenging in severe cases of soft tissue and bony loss. The authors present a case of a 20-year-old right-hand dominant female involved in a motor vehicle accident who sustained severe crush injuries and burns to her right hand. Her injuries included soft tissue and bony defects extending from the thumb to the distal radius, namely avulsion of the thumb and significant loss of the distal radial and carpal column, resulting in severe wrist instability. We employed a three-segment vascularized osteocutaneous fibula flap to reconstruct the thumb and wrist to restore bony construct, carpal support, and soft tissue coverage. Thumb motion could not be achieved, but this technique offered a sensate, functional post for opposition and the appearance of an anatomic hand. Because of this surgery, the patient was enabled to graduate from college and pursue full-time employment. The authors hope that this report will add to the fund of knowledge and surgeon armamentarium for similar devastating injuries demanding thumb and wrist reconstruction.

Experimental and analytical study of square tubed concrete-encased cross-shaped steel (TCCS) columns under axial compression

This paper presents an experimental and analytical study on square tubed concrete-encased cross-shaped steel (TCCS) columns under axial compression. The effect of test variables covering the steel section types (Type B and L), steel tube thicknesses (2.75, 5.00 and 7.50 mm) and external CFRP layers (0, 1, 2 and 4) on the mechanical behavior of the specimens were investigated. The test results show that obvious local buckling of the flange is mainly observed in the specimens embedded with Type B steel section with a larger width-thickness ratio and severe concrete crushing is also detected in the corresponding position. The constraint provided by the flange of the Type B steel section in suppressing the lateral deformation of inner concrete is weaker than that of the Type L section, leading to the inferior behavior of load capacity, ductility, and energy absorption, whereas the impact of steel section type becomes less significant to the dilation behavior of TCCS columns with sufficient confinement provided by the external tube. Furthermore, the confinement mechanism of steel section confined concrete is interpreted based on the buckling theory, and the stress–strain model of confined concrete in TCCS columns is proposed by considering the dual confinement from external tube and steel section. Finally, an analytical model is developed to predict the load–strain relationship of TCCS columns according to the section analysis method. By comparing the predictions with the experiments in this paper and several existing literature, it can be found that the proposed analytical model possesses satisfactory accuracy and applicability.