Search

A micro-pulse detonation engine (μPDE) was designed and installed to a direct-connect scramjet combustor of Pusan National University (PNU-DCSC). The active excitation on the scramjet combustor was experimentally studied using the μPDE operating at frequencies of 10–20 Hz. A vitiation air heater (VAH) was used to supply high-enthalpy vitiated air to the isolator and the scramjet combustor at a Mach number of 2.0, with a total temperature of 1600 K and a total pressure of 1.68 MPa. The exit of μPDE was located at the center of the cavity of the scramjet combustor. Active excitation was performed at equivalence ratios of 0.111 and 0.163, and characteristics were analyzed through Schlieren recording and bottom wall pressure measurement. As a result, when the detonation emitted from the μPDE entered the scramjet combustor, it instantly formed a shock train and moved forward within the scramjet combustor. The flame instantaneously changed from the cavity shear layer flame to the cavity flame. Through bottom wall pressure measurement, it was also observed that active excitation resulted in a significant pressure increase near the cavity compared to when active excitation was not performed. This revealed combustion characteristics, indicating improved combustion efficiency from the pressure increase in the scramjet combustor. [ABSTRACT FROM AUTHOR]

A 6‐month‐old intact female mixed‐breed kitten presented with severe exophthalmos of the left eye. Periocular lesions, including subconjunctival haemorrhage, third eyelid protrusion, and left eyelid oedema, were detected in the absence of globe retropulsion. The left intraocular pressure was increased, and ocular ultrasonography revealed ipsilateral retrobulbar fluid. Coagulation panels were markedly prolonged and severe anaemia was detected. Ultrasound‐guided retrobulbar centesis performed to decrease intraocular pressure yielded blood. Based on the history and clinical findings, anticoagulant rodenticide intoxication was suspected. Treatment included partial tarsorrhaphy and the administration of topical antibiotics, artificial tears, and vitamin K1. Fresh whole blood and fresh frozen plasma were transfused for supportive therapy. Coagulation parameters improved after 7 days of hospitalisation. The periocular lesions resolved within 14 days, despite persistent optic nerve damage and blindness. This case report raises the possibility that anticoagulant rodenticide toxicity may result in retrobulbar haemorrhage in the absence of other typical cavitary bleeding. Although uncommon, anticoagulant rodenticide toxicity should be considered in cats with retrobulbar haemorrhage. [ABSTRACT FROM AUTHOR]

Substantial endeavors are dedicated to advance the electrochemical performance of Ni‐rich Li[Ni1−x−yCoxMny]O2 (NCM) and Li[Ni1−x−yCoxAly]O2 (NCA) cathode, with a particular focus on doping, aimed at addressing cycling durability and thermal stability of the cathodes. Mn is widely considered an attractive dopant because of its abundance and considerably lower cost than other dopant candidates. However, despite the long history of research, the role of Mn doping remains poorly understood, confined to the historical level, and associated with crystal structural and chemical aspects. Herein, the role of Mn doping beyond its classical role is redefined, particularly in terms of cathode microstructure. Introducing excess Mn during calcination significantly engineers the nano‐ and micro‐level structural features of the peripheral grains of the Li[Ni0.910Co0.079Al0.011]O2 cathode. The microstructural modification achieved by doping with 4 mol% Mn significantly improves the electrochemical cycling performance of the cathode, extending the capacity retention up to 76.5% after 1000 cycles under fast charging conditions (3 C and 45 °C). Hence, by providing an alternative approach to redesign the structural features of the cathode, Mn doping offers a significant step toward the sustainable development of high‐performance Ni‐rich Li[Ni1−x−y−zCoxMnyAlz]O2 (NCMA) cathodes for next‐generation lithium‐ion batteries. [ABSTRACT FROM AUTHOR]

Botulinum toxin A (BONT/A) injections play a central role in the treatment of upper limb spasticity in stroke patients. We proposed structured stretching exercises to enhance the effect of post-stroke spasticity relief of the upper limbs following BONT/A injections. A total of 43 patients who had a stroke with grade 2 spasticity or higher on the Modified Ashworth Scale (MAS) in their upper-limb muscles were randomly assigned to the intervention (n = 21) or control group (n = 22). The former received structured stretching exercises after their BONT/A injections for 20 min, 5 days per week, for 6 months at a hospital, while the others conducted self-stretching exercises at home. The outcome measures were assessed before the intervention (T0) and after three (T1) and six months (T2). Significantly greater improvements in the MAS scores of the elbows, wrists, and fingers were found in the intervention group's patients at T1 and T2. The behavioral outcome measures, including shoulder pain, activities of daily living, and quality of life, and our electrophysiological studies also showed a significantly higher enhancement in this patient group. In conclusion, the structured stretching exercises plus BONT/A injections for six months showed a superior effect in relieving post-stroke upper-limb spasticity compared to self-stretching exercises. [ABSTRACT FROM AUTHOR]

Background and Objectives: Cervical radiculopathy (CR) manifests as pain and sensorimotor disturbances in the upper extremities, often resulting from nerve root compression due to intervertebral disc herniation, degenerative changes, or trauma. While conservative treatments are initially preferred, persistent or severe cases may require surgical intervention. Ultrasound-guided selective nerve root block (SNRB) has emerged as a promising intervention for alleviating symptoms and potentially obviating the need for surgery. This study evaluates the therapeutic efficacy of ultrasound-guided SNRB in managing chronic CR, aiming to determine its potential in symptom relief and delaying or avoiding surgical procedures. Materials and Methods: A retrospective analysis was conducted on 720 outpatients treated for CR between October 2019 and March 2022. After excluding patients with traumatic CR, previous surgeries, malignancies, progressive neurological symptoms requiring immediate surgery, or inadequate conservative treatment, 92 patients who had experienced cervical radicular pain for more than three months and had failed to improve after more than six weeks of conservative treatment with VAS scores ≥ 5 were included. The patients underwent single or multiple ultrasound-guided SNRB procedures, involving the injection of dexamethasone and lidocaine under real-time ultrasound guidance. Symptom severity was assessed at the baseline, and at 4, 8, and 12 weeks post-procedure using the Visual Analog Scale (VAS). The data collected included age, sex, presence of neck and/or radicular pain, physical examination findings, recurrence of symptoms, improvement in symptoms, and whether surgical intervention was ultimately required. Statistical analyses were performed to identify the factors associated with symptom improvement or recurrence. Results: Significant symptom improvement was observed in 69 (75.0%) participants post-SNRB, with 55 (79.7%) showing improvement at 4 weeks, 11 (15.9%) at 8 weeks, and 3 (4.4%) at 12 weeks. Symptom recurrence, defined by an increase in VAS score accompanied by a pain flare lasting at least 24 h after a pain-free interval of at least one month, was noted in 48 (52.2%) patients. The presence of combined neck and radicular pain was a significant predictor of recurrence (p = 0.008). No significant associations were found between symptom relief and factors such as age, gender, initial pain severity, or MRI findings. Conclusions: Ultrasound-guided SNRB effectively manages chronic CR, providing substantial symptom relief and potentially reducing the need for surgical intervention. This technique offers a promising conservative treatment option, especially given its real-time visualization advantages and minimal radiation exposure. [ABSTRACT FROM AUTHOR]

The reaction characteristics of the SO2 oxidation catalyst by the catalyst preparation method were analyzed by investigating the catalyst properties on the TiO2 support using a vanadium-alkali (K) compound containing the catalyst. The slurry mix method and the dry ball milling method were used for the production of the catalyst. In this process, the difference in interaction between the active material (V) and the support (TiO2) has been confirmed. Especially, the high proportion of non-stoichiometric species of the initial catalyst reflects the high interaction between vanadium and TiO2. Therefore, an increase in non-stoichiometric species such as V4+ indicates an increase in the interaction between TiO2 and V2O5. In particular, the interaction between the support-active material improves the transfer of SO2 adsorbed on the support TiO2 to the active material (V2O5). Therefore, it induces the production of a high proportion of the active substance (VVO)2O(SO4)44− and consequently increases the SO2 oxidation performance. [ABSTRACT FROM AUTHOR]

Toe grip strength has recently been suggested to play an essential role in maintaining balance and postural stability for ambulatory function in older populations. This study aimed to investigate its association with improving gait function three months after onset in patients with subacute stroke. This longitudinal cohort study included 98 first-ever stroke patients (67 ± 9 years, 56% female) within one month from the onset who could not ambulate independently. Functional outcome indicators, including toe grip strength, hand grip strength, knee extensor strength, Fugl-Meyer Assessment of Lower Extremity (FMA_LE), and the Postural Assessment Scale for Stroke (PASS), were assessed before and three months after the intervention. We analyzed the correlation between participants' gait function using a 10-meter walk test time and various functional indicators. Then, multiple linear regression analysis was used to investigate whether toe grip strength was related to the improvement of gait function. Correlation analysis revealed a significant positive correlation between the 10MWT time and toe grip strength ratio (affected/unaffected side), with a moderate effect size (r = −0.61, p <0.001). Multiple regression analysis with covariates showed a significant relationship between 10MWT time and toe grip strength ratio (β = −0.113, p < 0.001), FMA_LE (β = −1.315, p = 0.004), PASS (β = −3.275, p <0.001), and age (β = −0.159, p = 0.004). In conclusion, toe grip strength was an essential factor associated with ambulatory function improvement in subacute stroke patients three months after onset. Additional toe grip muscle strengthening rehabilitation treatment can be expected to help improve the ambulatory function of subacute stroke patients in the future. [ABSTRACT FROM AUTHOR]

Background: It may be challenging for practitioners to secure vascular access in animals, especially in a state of shock. Aim: This study aimed to evaluate the clinical relevance of commercial 16‐gauge intravenous (IV) catheter stylet vs. 15‐gauge intraosseous (IO) vascular access in emergencies. Methods: Six healthy dogs were used in this study. After general anaesthesia, IO catheterisation was performed on both trochanteric fossae of the femurs using a commercial 16‐gauge IV catheter stylet and EZIO 15‐gauge IO needle. The pressures were measured by manual, gravity and mechanical infusion for 5 min each. Additionally, insertion time and success rate were recorded. Results: In hand infusion, mean pressure of a 16‐gauge IO (605.06 ± 49.13 mmHg) was statistically lower than that of a 15‐gauge EZIO IO catheterisation (718.84 ± 93.09 mmHg). In gravity infusion, there was no significant difference in pressure during injection between the 16‐gauge IV catheter (52.23 ± 14.48 mmHg) and 15‐gauge EZIO IO catheterisation (50.68 ± 11.89 mmHg). In mechanical infusion, mean pressure of the 15‐gauge EZIO IO catheterisation (128.25 ± 50.16 mmHg) was lower than that of the 16‐gauge IV catheter (152.56 ± 67.23 mmHg). The insertion times of a 16‐gauge IV catheter and 15‐gauge EZIO IO catheterisation were 16.79 ± 0.92 and 11.65 ± 1.70 s, respectively. The success rates of the insertion were similar between both groups. Conclusion: This study shows that IO catheterisation with a commercial IV catheter stylet can be an alternative method of IO catheterisation in an emergency, especially for rapid vascular access. [ABSTRACT FROM AUTHOR]

This article examines the power imbalance associated with core-periphery structure in disaster response networks, drawing on resource dependence, institutional, and network theories. By employing Borgatti and Everett's (1999) algorithm and Bayesian logistic mixed-effects models to analyse data on collaborative ties among organizations that responded to the 2015 epidemic in South Korea, the authors found that a network with a small core emerged during the public health crisis. The ability for organizations to not only provide but also attract resources and the professional and governmental positions that they had held in the disaster management system were associated with the core-periphery structure. [ABSTRACT FROM AUTHOR]