Stroke Duration Research Articles

Numerical Simulations of Thermodynamic Processes in the Chamber of a Liquid Piston Compressor for Hydrogen Applications

This paper presents the results of numerical simulations examining the thermodynamic processes during hydraulic hydrogen compression, using COMSOL Multiphysics® 6.0. These simulations focus on the application of hydrogen compression systems, particularly in hydrogen refueling stations. The computational models employ the CFD and heat transfer modules, along with deforming mesh technology, to simulate gas compression and heat transfer dynamics. The superposition method was applied to simplify the analysis of hydrogen and liquid piston interactions within a stainless-steel chamber, accounting for heat exchange between the hydrogen, the oil (working fluid), and the cylinder walls. The study investigates the effects of varying compression stroke durations and initial hydrogen pressures, providing detailed insights into temperature distributions and energy consumption under different conditions. The results reveal that the upper region of the chamber experiences significant heating, highlighting the need for efficient cooling systems. Additionally, the simulations show that longer compression strokes reduce the power requirement for the liquid pump, offering potential for optimizing system design and reducing equipment costs. This study offers crucial data for enhancing the efficiency of hydraulic hydrogen compression systems, paving the way for improved energy consumption and thermal management in high-pressure applications.

A Preliminary Study on Effectiveness of Varying Dose of Paretic Upper Limb Training with Visual Deprivation in Poststroke Patients: A Randomised Clinical Tria

Introduction: Poststroke Upper Limb (UL) rehabilitation with visual deprivation has shown potential in enhancing motor recovery through neural plasticity. However, the optimal dosage remains unclear. Aim: To evaluate the effectiveness of varying doses of paretic UL training with visual deprivation in stroke patients. Materials and Methods: This single-centre, parallel-group, single-blinded, randomised clinical trial involved 36 stroke patients who were randomly distributed into three groups varying in treatment frequency: Group A (n=12) received two sessions per week, Group B (n=12) received three sessions per week, and Group C (n=12) received five sessions per week for four weeks. Each session lasted 40 minutes of visual deprivation training for the paretic UL. A trained physiotherapist, who was blinded to group allocation, conducted pre- and postevaluations. The Wolf Motor Function Test was the principal outcome measure. This study utilised Analysis of Variance (ANOVA) for between group comparisons and independent sample t-tests for within group pre-post comparisons, with a significance level of 5%. Results: Out of the 36 study participants, three dropouts were recorded by the completion of the study: one from Group A and two from Group B. The average age of participants was 54.75±8.06 years, and the duration of stroke was 10.08±4.35 months, with 69.4% experiencing left-sided involvement. All groups showed significant improvement. Group C exhibited the highest improvement in the Wolf Motor Function Test score, with an F value of 42.86 (p-value=0.001). Post-hoc analysis revealed a significant difference in motor score improvement in Group C, (p-value=0.001). Additionally, Group C demonstrated greater improvements in the Wolf Motor Functional Ability Score (WMFAS), with a mean improvement of 15.00±0.82 (F=158.00, p-value=0.001). Conclusion: Visual deprivation training with higher intensity (five sessions per week) was effective in improving UL motor function in poststroke patients, proving superior to lower intensity (two or three sessions per week). These results highlight the importance of frequent training. Future research with larger and more diverse stroke patient populations, as well as long-term follow-up studies, is needed to validate these findings.

The Association Between Urinary Incontinence With Pelvic Pain and Sensory-Motor Function in Older Women With Stroke.

The study aimed to investigate the association between urinary incontinence (UI) severity, pelvic pain, and sensory-motor function in older women with stroke. A cross-sectional prospective study was carried out with 102 older women individuals with stroke. Barthel Index (BI), Incontinence Impact Questionnaire Short Form (IIQ-7), Urogenital Distress Inventory (UDI-6), Pelvic Pain Impact Questionnaire (PPIQ), Somatosensory Amplification Scale (SASS), and Somatic Sensitivity Scale (SeSS) were used for clinical measurements. Partial correlational analyses with age, stroke duration, and BMI as covariates revealed a moderate positive correlation between SASS and IIQ-7 (r = 0.315, p < 0.001) and UDI-6 (r = 0.376, p < 0.001). On the other hand, there was a strong positive correlation between SASS and PPIQ (r = 0.522, p < 0.001). SeSS had a low positive correlation with IIQ-7 (r = 0.198, p < 0.05) and UDI-6 (r = 0.203, p < 0.05). In addition, there was a positive and moderate correlation between SeSS and PPIQ (r = 0.384, p < 0.001). Multivariate linear regression analysis revealed causality of SASS (R2 = 0.381, p < 0.001) and SeSS (R2 = 0.167, p < 0.001) with PPIQ. Increased abnormal sensory sensitivity is associated with increased pelvic pain levels in women with stroke. Clinicians should consider sensory abnormalities, especially pain, within the scope of UI in women with stroke. Our results provide preliminary essential data for sensory and pain awareness during pelvic rehabilitation in stroke patients.

Research on the difference of stroke characteristics and stroke effect between different stroke duration of table tennis players

This study aimed to explore the differences in joint kinematic characteristics and stroke effect between fast and slow strokes of table tennis players. Thirty-four table tennis players were randomly selected as participants for this experiment. A high-speed infrared motion capture system was used to collect kinematic data of the right-side upper and lower limb joints during strokes. Simultaneously, a high-speed camera was used to measure the stroke effect. According to the duration of a stroke, the stroke data were classified into two types: fast-stroke and slow-stroke using a two-step clustering algorithm. The duration of the three phases of fast-stroke was shorter, with faster ball speed and stronger spin. Compared with slow-stroke, fast-stroke exhibited shorter displacements in the three lower limb joints and faster linear velocities in the three upper limb joints. In addition, the motion angles of the knee and ankle joints were smaller, while the angles of the hip, shoulder, and elbow joints were larger, with higher angular velocities. Increasing the extension speed of the lower limbs, the flexion speed of the elbow joints, and the wrist movement speed can achieve fast strokes, enhancing ball speed and spin. Small and quick hip joint movement can effectively transfer energy to the upper limbs, increasing the movement speed of the elbow and wrist joints, thus improving the ball speed and spin of the stroke.

Brain-computer interfaces based on near-infrared spectroscopy and electroencephalography registration in post-stroke rehabilitation: a comparative study

Motor imagery training under the control of a brain-computer interface (BCI) facilitates motor recovery after stroke. The efficacy of BCI based on electroencephalography (EEG-BCI) has been confirmed by several meta-analyses, but a more convenient and noise-resistant method of near-infrared spectroscopy in the BCI circuit (NIRS-BCI) has been practically unexamined; comparisons of the two types of BCI have not been performed.Objective: to compare the control accuracy and clinical efficacy of NIRS-BCI and EEG-IMC in post-stroke rehabilitation.Material and methods. The NIRS-BCI group consisted of patients from an uncontrolled study (n=15; 9 men and 6 women; age – 59.0 [49.0; 70.0] years; stroke duration – 7.0 [2.0; 10.0] months; upper limb paresis – 47.0 [35.0; 54.0] points on the Fugl-Meyer Assessment for motor function evaluation of the upper limb – FM-UL). The EEG-IMC group was formed from the main group of the randomized controlled trial “iMove” (n=17; 13 men and 4 women; age – 53.0 [49.0; 70.0] years; stroke duration – 10.0 [6.0; 13.0] months; upper limb paresis – 33.0 [12.0; 53.0] points on the FM-UL). Patients participated in a comprehensive rehabilitation program supplemented by BCI-guided movement imagery training (average of 9 training sessions).Results. Median of average BCI control rates achieved by the patients was 46.4 [44.2; 60.4]% in the NIRS group and 40.0 [35.7; 45.1]% in the EEG group (p=0.004). For the NIRS-BCI group, the median of the maximum BCI control accuracy achieved was 66.2 [56.4; 73.7]%, for EEGBCI – 50.6 [43.0; 62.3]% (p=0.006). The proportion of patients who achieved a clinically significant improvement according ARAT and the proportion of patients who achieved a clinically significant improvement according FM-UL were comparable in both groups. The NIRS-BCI group showed greater improvement in motor function compared to the EEG-BCI group according to Action Research Arm Test (ARAT; an increase of 5.0 [4.0; 8.0] points compared to an increase of 1.0 [0.0; 3.0] points; p=0.008), but not according to FM-UL scale (an increase of 5.0 [1.0; 10.0] and 4.0 [2.0; 5.0] points, respectively; p=0.455).Conclusion. NIRS-BCI has an advantage in control accuracy and ease of use in clinical practice. Achieving higher control accuracy of BCI provides additional opportunities for the use of game feedback scenarios to increase patient motivation.

Dynamics of change in the polytropic exponent in the expansion stroke of diesel

In the article is considered the problem of achieving the optimal duration of the working stroke of a diesel engine piston during the expansion process and obtaining the maximum efficiency coefficient (EC). For this purpose, a hypothesis was put forward about the pumping action of the piston on the flow of expanding gases during the power stroke of an diesel internal combustion engine (ICE) as the piston moves from upper dead point (UDP) to bottom dead point (BDP).At a certain moment of expansion, the rate of the flow of expanding gases turns out to be equal to the rate with which the same flow is slowed down by the moving piston.The equality of these rates leads to the formation of a flow break line and has a significant impact on the nature of the change in the polytropic exponent; the value of the exponent becomes equal to one: n = 1. This indicates that the optimum duration of the engine’s working stroke has been achieved and corresponds to the maximum power that can be removed during the diesel engine’s operating cycle. An experimental relation was obtained between the initial p1 and final p2 pressures in the cylinder during gas expansion with the gas flow rate and the rate of deceleration of this flow due to the pumping action of the piston. An equation for the continuity of gas flow has been compiled for the process of gas expansion in the cylinder of an ICE with closed gas exchange organs. Based on this equation, the numericalvalue of the acceleration of gravity in the cylinder of ICE is obtained: gф ≈ 8,7 м/с2 &lt; g, which confirms the pumping action of the piston. A theoretical (and graphical) dependence of the polytropic process exponent on the flow rate of expanding gases is obtained. The dependence allows to calculate the polytropic exponent and establish the gas relaxation period, indicating the achievement of the optimal duration of the piston stroke.

Prevalence of poststroke fatigue and its relationship with clinical characteristics among community-dwelling stroke survivors: A cross-sectional survey

Background and objectivePoststroke fatigue is widely overlooked due to a lack of awareness, definite cause, and cure. It is influenced by cultural variance in psychosocial factors and stroke epidemiology patterns across different countries. To date, the prevalence of poststroke fatigue has not been determined in the Indian setting. Hence our objective was to estimate the prevalence of fatigue among community-living late subacute and chronic stroke survivors. Additionally, we determined the association between poststroke fatigue and participants’ clinical and demographic data. MethodsA cross-sectional survey was conducted among first-time stroke survivors following discharge from two tertiary care hospitals. Medical records were screened and included if they met the criteria for age >18 years, able to follow a two-step command with no existing neurological or systemic conditions that would influence fatigue scores. Telephonic consent was obtained, and an interview was conducted to obtain the scores for fatigue, daytime sleepiness, depression, functional mobility, and disability. ResultsA total of 323 participants (mean age: 60.3 ± 12.6 years, mean stroke duration: 8.6 ± 4.4 months) completed the interview. Poststroke fatigue was reported in 11.8 % (n = 38) of the population. Occupational status (χ2 = 5.73), functional mobility (χ2 = 5.84), and disability scores (χ2 = 8.00) were significantly associated (p < 0.05) with fatigue scores. Individuals with disability exhibited five times (OR = 5.00, CI: 1.45–17.23, p = 0.01) higher odds of experiencing fatigue than those without disability. ConclusionOur study reported a relatively lower prevalence of fatigue among community-living late subacute and chronic stroke survivors. Implementing strategies to address these contributing factors could effectively ease fatigue in individuals recovering from stroke.

Enhancing underwater unmanned vehicle efficiency through asymmetric dynamics in manta-like swimming

This study explores the hydrodynamic performance of a National Advisory Committee for Aeronautics 0012 foil using computational fluid dynamics with the unsteady Reynolds-averaged Navier–Stokes (URANS) method and shear stress transport k-ω model to assess the impact of asymmetric motion parameters in manta-like swimming. The angles of attack during the mid-upstroke (αmu), mid-downstroke (αmd), and stroke duration (S) are varied to understand their effect. At low Strouhal numbers (StA = 0.2–0.35), a smaller αmd compensates for thrust loss at the start of the upstroke due to a greater αmu. At high Strouhal numbers (StA = 0.5), a greater αmd reduces negative thrust and compensates for the smaller thrust generated by a small αmu during the upstroke. Shorter stroke durations increase asymmetry, leading to more significant positive thrust peaks during the downstroke. If both the angle of attack and S are large, the slower downward speed extends negative thrust, reducing thrust peaks and lowering average thrust. A smaller stroke duration combined with a large angle of attack enhances efficiency due to a greater thrust-to-power ratio, highlighting the interplay between these parameters. A smaller S and greater αmd and StA maximize thrust and efficiency, suggesting aquatic organisms increase thrust while ensuring propulsion efficiency by using a large angle of attack and an asymmetric stroke duration. This study demonstrates how asymmetric parameters interact, providing insights into designing biomimetic underwater vehicles. The findings suggest that asymmetric dynamics enhance propulsion efficiency.

Prevalence and correlates of post-stroke anxiety in Changde, China during 2023 following the lifting of COVID-19 restrictions.

Studies on post-stroke anxiety (PSA) following the lifting of COVID-19 restriction measures are currently lacking. We investigated the factors affecting PSA after full release of COVID-19 epidemic in China. Patients with stroke admitted to the First People's Hospital of Changde City from March 2023 to September 2023 participated in a questionnaire survey comprising a general demographic questionnaire, the Generalized Anxiety Scale-7. Additionally, data on the National Institutes of Health Stroke Scale, modified Rankin Scale, C-reactive protein (CRP), thyroid-stimulating hormone (TSH), homocysteine, TOAST classification, and the stroke site were collected, and the correlations between these indices and the mental health conditions of the patients were evaluated. Among 947 patients, the incidence of PSA was 14.57%.PSA was not linked to prior COVID-19 infection. This study found that Sleep duration (P=0.01), hyperlipidemia (P=0.01), migraine (P=0.02), and family history of stroke (P=0.01) were associated with PSA. Our study found that the prevalence of PSA was 14.57%. In addition, sleep duration, hyperlipidemia, migraine and family history of stroke were independent risk factors for PSA following the lifting of COVID-19 restrictions.

A Comparison of Paddle Forces between Whitewater and Flatwater Training in C1 Canoe Slalom.

Becoming an elite canoe slalom athlete requires thousands of hours of training, spread over many years. It is difficult to assess the correct balance between flatwater and whitewater training because differences in the paddle forces on these terrains are not known. The aim of this study was to describe paddle forces during canoe slalom training on flatwater and whitewater courses for the C1 canoe category. Paddle forces for twenty C1 canoe slalom athletes were quantified during all-out figure-of-eight tests on a flatwater course and during race simulations on a whitewater course. Paddle forces were measured using strain gauges embedded in the paddle shaft and quantified by their force, impulse, and stroke durations. The mean force during the pull phase of the paddle strokes was not significantly different between the flatwater and whitewater courses; however, the longer pull phase durations led to a greater pull phase impulse when paddling on the whitewater course. This study indicates that training for all-out runs on a whitewater course is more demanding for canoe slalom athletes than performing all-out trials on a flatwater figure-of-eight course. This evidence may help to develop effective training plans that are essential to reach the highest levels of the sport.

Sarcopenia, frailty prevalence, and related factors in patients with stroke: A cross-sectional analytical study from Turkey.

Sarcopenia and frailty may develop at varying rates depending on the metabolic, structural, and functional changes in the muscle structure after stroke. To evaluate the prevalence of sarcopenia and frailty in patients with stroke and affecting clinical parameters. This was a cross-sectional and analytical study. Twenty-six (49.1%) women and 27 men (50.9%) with stroke with an average age of 60.2 ± 10.3 (median = 62) years were included in the study. To evaluate physical performance, balance, and mobility, we used the 4-meter walk test (4-MWT), timed up and go test, chair sit and stand test, and the Berg Balance Scale (BBS). Sarcopenia was diagnosed according to the Asian Working Group for Sarcopenia 2019 criteria. The SARC-F scale was used for sarcopenia. The average stroke duration was 21.6 ± 18.2 months. Prefrailty was present in 14 (26.4%) patients, frailty was present in 34 (64.2%) patients, and two (3.8%) patients were normal. Sarcopenia was detected in 28 (52.8%) patients. According to handgrip strength, the prevalence of low muscle strength was 17% (n= 9). In the sarcopenic group, female sex (p= 0.005) was more frequent, 4-MWT was longer (p= 0.003), chair stand test results were lower (p< 0.001), the clinical frailty scale (CFS) was higher (p< 0.001), fall risk was higher compared with the BBS (p< 0.001), there was lower HG strength (p= 0.009), lower malnutrition scores (PNI, prognostic nutritional index, p< 0.001), and lower lymphocyte counts (p= 0.037). EAT-10 scores and dysphagia presence (p= 0.026), the presence of malnutrition (p< 0.021) and Nottingham Health Profile score (p< 0.001) were higher in the sarcopenic group. Sarcopenia and frailty frequently develop in patients with chronic stroke, with low lymphocyte counts, physical performance, muscle strength, and mobility and balance scores, and it is associated with poor prognostic factors including high disease severity, dysphagia, malnutrition, risk of falling, and poor quality of life.

Comparison of Bilateral Versus Unilateral 5 Hz or 1 Hz Repetitive Transcranial Magnetic Stimulation in Subacute Stroke: Assessment of Motor Function in a Randomized Controlled Study.

Repetitive transcranial magnetic stimulation (rTMS) can enhance brain plasticity after stroke. At low frequencies, rTMS has an inhibitory effect, whereas at high frequencies, it has an excitatory effect. Combining both frequencies in bilateral stimulation is a new rTMS protocol under investigation, especially in the subacute stage. Fifty-five patients with subacute stroke were divided into four groups according to the rTMS protocol delivered: bilateral, inhibitory, excitatory, and control groups. All groups received concomitant task-oriented physiotherapy. Pretreatment to posttreatment assessment was performed twice, immediately after sessions and 1 month later. Volitional motor control was evaluated by Fugl-Meyer and Wolf motor function tests, and for spasticity, the Ashworth scale was used. All groups showed significant improvement. Bilateral, inhibitory, and excitatory groups showed same efficacy, but the bilateral protocol was superior in spasticity. No correlations were found between improvement and stroke duration and site except for spasticity. Bilateral rTMS shows a comparable effect to inhibitory and excitatory rTMS in improving motor disability in subacute stroke. However, it is superior for spasticity.

The incidence of lower extremity amputation and its associated risk factors in patients with diabetic foot ulcers: A meta-analysis.

This study analysed the incidence of lower extremity amputation and its associated risk factors in patients with diabetic foot ulcers. This study systematically searched both Chinese and English databases, including CNKI, Wanfang, VIP, PubMed, EMBASE and Web of Science, to identify cohort studies related to lower extremity amputation and associated risk factors in patients with diabetic foot ulcers up to October 2023. The patients were stratified based on whether they underwent lower extremity amputation, and relevant data, including basic information, patient characteristics, complications, comorbidities and pertinent laboratory test data, were extracted from the included studies. The literature quality assessment in this study utilized the Newcastle-Ottawa Scale to screen for high-quality literature, resulting in the inclusion of 16 cohort studies, all of which were of at least moderate quality. Meta-analysis of outcome indicators was conducted using the Stata 14.0 software. The results indicate that the overall amputation rate of lower extremities in patients with diabetic foot ulcers is 31% (0.25, 0.38). Among the 16 variables evaluated, gender (male), smoking history, body mass index (BMI), hypertension, cardiovascular disease, kidney disease, white blood cell count, haemoglobin and albumin levels were found to be correlated with the occurrence of lower extremity amputation in patients with diabetic foot ulcers. However, no significant correlation was observed between age, diabetes type, duration of diabetes, stroke, glycosylated haemoglobin, creatinine and total cholesterol levels and lower extremity amputation in patients with diabetic foot ulcers. This meta-analysis indicates that the overall amputation rate in patients with diabetic foot ulcers is 31%. Factors such as gender (male), smoking history, high BMI, hypertension, cardiovascular disease, kidney disease, white blood cell count, haemoglobin and albumin levels are identified as significant risk factors for lower extremity amputation in diabetic foot ulcer patients. These findings suggest that attention should be focused on these risk factors in patients with diabetic foot ulcers to reduce the risk of lower extremity amputation. Therefore, preventive and intervention measures targeting these risk factors are of significant importance in clinical practice. (Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/, identifier [CRD42024497538]).

The influence of patient motivation on the motor function restoration during stroke recovery. Preliminary results of a clinical study

BACKGROUND: Acute cerebrovascular accidents lead to disability. The most important task is the rehabilitation and adaptation of these patients to society. Impaired motivation reduces the effectiveness of rehabilitation measures. AIMS: To assess the motivation of patients during stroke recovery; identify relationships between the level of motivation, duration and type of stroke, and cognitive and demographic indicators; and determine the influence of the patient’s initial level of motivation on the effectiveness of the rehabilitation. MATERIALS AND METHODS: This prospective study analyzed 36 patients with hemiparesis in the early and late recovery period of stroke. All patients were assessed according to the international classification of functioning, disability, and health; functional independence scale; Rivermead mobility index; degree of paresis according to the Medical Research Committee scale; level of spasticity according to the Ashford scale; risk of falls assessment according to the Morse scale; assessment of function of the upper and lower extremities using the Fugl–Meyer test; and balance assessment using the Berg scale. RESULTS: A significant positive correlation was found between the patient’s motivation and cognitive indicators: the integral level of the BTLD (r=0.653; p=0) and the integral indicator of the Mini-Mental State Examination (r=0.536; p=0.001). No convincing evidence supports the connection between the motivation level and indicators as such sex, age, body mass index, time since stroke, stroke type and location, pain level, functional independence level, and motor impairment. Although a trend toward greater positive changes in functional recovery of the arm, leg, balance, and overall independence was observed, no significant difference was found between groups. CONCLUSION: A significant relationship was found between motivation and cognitive functions, which can serve as predictors of the motivation level of patients when planning rehabilitation activities. A trend toward positive changes in functional recovery of the arm, leg, balance, and overall independence was found in patients with high motivation levels.

Amide proton transfer MRI at 9.4 T for differentiating tissue acidosis in a rodent model ofischemic stroke.

Differentiating ischemic brain damage is critical for decision making in acute stroke treatment for better outcomes. We examined the sensitivity of amide proton transfer (APT) MRI, a pH-weighted imaging technique, to achieve this differentiation. In a rat stroke model, the ischemic core, oligemia, and the infarct-growth region (IGR) were identified by tracking the progression of the lesions. APT MRI signals were measured alongside ADC, T1, and T2 maps to evaluate their sensitivity in distinguishing ischemic tissues. Additionally, stroke under hyperglycemic conditions was studied. The APT signal in the IGR decreased by about 10% shortly after stroke onset, and further decreased to 35% at 5 h, indicating a progression from mild to severe acidosis as the lesion evolved into infarction. Although ADC, T1, and T2 contrasts can only detect significant differences between the IGR and oligemia for a portion of the stroke duration, APT contrast consistently differentiates between them at all time points. However, the contrast to variation ratio at 1 h is only about 20% of the contrast to variation ratio between the core and normal tissues, indicating limited sensitivity. In the ischemic core, the APT signal decreases to about 45% and 33% of normal tissue level at 1 h for the normoglycemic and hyperglycemic groups, respectively, confirming more severe acidosis under hyperglycemia. The sensitivity of APT MRI is high in detecting severe acidosis of the ischemic core but is much lower in detecting mild acidosis, which may affect the accuracy of differentiation between the IGR and oligemia.

Optimal propulsion efficiency for NACA0012 foils with asymmetries in motion: A hybrid approach using the Taguchi method and artificial neural networks

This study uses the Taguchi method and artificial neural networks to optimize the thrust and propulsion efficiency of a NACA0012 foil, examining variables like downstroke duration (S = 0.3–0.5), angle of attack during downstroke and upstroke (αmd, αmu = 20°–50°), and Strouhal number (St = 0.2–0.5). Analysis shows that the St greatly affects thrust, while the αmu is pivotal for propulsion efficiency. Thrust is optimized by using a shorter S of 0.3, a greater αmd of 50° and a larger St of 0.45–0.5 and efficiency is optimized by using symmetric S of 0.5, a smaller αmd, αmu of 20° and a lower St of 0.35–0.39. Force and flow field analysis shows that certain combinations optimize thrust by mitigating negative thrust in the early downstroke, though they increase power consumption, lowering overall efficiency. Configurations balancing stroke duration and minimizing the angle of attack enhance efficiency by decreasing power demand for steady thrust. Wake structure analysis reveals that optimal efficiency involves generating reverse Kármán vortex streets, while optimizing thrust leads to a more chaotic wake. This study advances fluid dynamics in propulsion systems and aids in designing more efficient, adaptable underwater vehicles by identifying the key balance between thrust optimization and propulsion efficiency.

Investigating the Relationship Between Clinical Characteristics, Mental Health, and Vascular Function in Minor Ischemic Stroke or Transient Ischemic Attack Patients.

Over the past decade, there has been extensive research exploring the relationship between vascular health and mental well-being, encompassing aspects such as mood and cognition. However, there is a notable gap in research focusing on the mental and vascular conditions of minor ischemic stroke or transient ischemic attack (TIA) patients, particularly within the Thai population. To investigate the clinical characteristics and mental issues related to vascular functions in patients who have experienced a minor ischemic stroke or TIA. This study, approved by the Buriram Hospital Ethics Committee (IRB: BR0033.102.1/8), adhered to the guidelines of the Helsinki Declaration and obtained informed consent from all participants. A prospective cross-sectional study was conducted at Buriram Hospital, a government regional hospital located in Buriram province, Thailand, involving twenty-three participants diagnosed with minor ischemic stroke or TIA. Measurements included clinical characteristics, Hospital Anxiety and Depression Scale-part Anxiety (HADS-A), Hospital Anxiety and Depression Scale-part Depression (HADS-D), mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), flow-mediated dilation (FMD), and brachial-ankle pulse wave velocity (baPWV). Linear regression analysis was employed to investigate the factors associated with vascular function (FMD and baPWV). The factor related to FMD was HADS-D (β = -0.5, 95% CI -0.33 to -0.04). Factors associated with baPWV included age (β = 0.51, 95% CI 5.05 to 39.50) and the duration of minor ischemic stroke or TIA (β = 0.48, 95% CI 25.41 to 290.99). FMD shows a connection with depressive symptoms in patients with minor ischemic stroke or TIA. Therefore, it is important to detect and provide appropriate treatment for depressive symptoms in these patients, as it may lead to improvements in vascular function and better cerebrovascular outcomes.

Effect of Cross-Sectional Designs of Different Ni-Ti Files on Shaping Ability After Repeated Usage in Simulated Root Canals.

Background and Objective: The study aimed was to compare the effect of cross-sectional designs of five rotary systems (One Curve, 2Shape, K3-i File, E3 Azure, Neolix), on the shaping ability of the files in simulated resin blocks under controlled conditions with five repeated use. The shaping ability of the files includes the following variables: (1) Longitudinal sectional area difference, (2) Canal wall surface area difference, (3) Canal volume difference, (4) SMI (structure material index) difference, (5) Cross-sectional area difference. Methods: Five rotary file systems: (1) One Curve, (2) 2Shape, (3) K3-i File, (4) E3 Azure, (5) Neolix, were tested in simulated J-shaped root canal resin blocks with a 45˚ angle of curvature. 10 files from each system, each one of the 10 files were used to prepare 5 resin blocks, named R1-R2-R3-R4-R5. All the used files from the 5 systems had tip size 25 diameter, and taper (6%), and length (25 mm). The first 4 rotary systems were used with a fixed speed (350 rpm), and fixed torque (3 Ncm), except for the fifth system which was used with a speed of (500 rpm), and torque (4 Ncm), Following the manufactural recommendation of each system. All the 250 resin blocks were prepared for Glide Path with manual reamers size 10, and 15, with a fixed working length 16 mm, then all the 250 samples were prepared with a Proglider rotary file from Dentsply (size 16 taper 3%), then finally were prepared with Edge Files (USA), with size 20 and taper 6%, reaching to the step of master preparation with the selected files of the 5 systems. Using a customized device for preparation to ensure fixed vertical force and to exclude any lateral force, preparation was done with EDTA solution as irrigation, with a fixed no. of 4 strokes for the first 5 systems and 9 strokes for the Neolix, the time was controlled by using a Metronome, each stroke duration was 6 seconds. Results: In the first, second, third, and fourth variables a statistically non-significant difference (P &gt; 0.05) was found between One curve and 2Shape, a statistically significant difference (P &lt; 0.05) was found between One Curve, K3-i File, E3 Azure, and Neolix. About the fifth variable which is the Cross-sectional area difference: the study compared the difference between the cross-section area of the canal at the point D8, comparing the cross-section area before and after preparation using ANOVA test and Post hoc test, a statistically significant difference (P &lt; 0.05) was found between the Neolix and (2shape, K3 i-File, and E3 Azure). Conclusion: The cross-sectional design of the endodontic rotary instrument had an obvious effect on the shaping ability of the system. Keywords: Cross-sectional design, Shaping ability, Nickle Titanium rotary files (One Curve, 2Shape, K3-i File, E3 Azure, Neolix).

Statistical and cross-sectional analysis of factors effecting the prevalence of pressure ulcer in hospital admitted stroke patients

Every year, millions of people around the world are disabled by stroke, it is well recognized that complications aftera stroke extend hospital stays and pressure ulcers, a stroke consequence, which can be prevented by educating the caregiver. The primary focus of this research is not only to investigate the prevalence of pressure ulcers (PU) among stroke patients, but this study also introduced a variety of factors which influence the formation of PU, such as restricted mobility, gender, duration of stroke, hypertension, diabetes, hygiene, type of mattress, malnutrition, awareness, etc. In addition, this research provides a comparative and statistical analysis, a cause of the catastrophic disabilities influenced by a variety of factors. Moreover, the proposed research also provides a room for the pertinent treatment of stroke patient to curtail the formation of pressure ulcer. In this research, a total of 120 stroke patients were initially included to monitor the frequency of pressure ulcers at incipient stage. Out of the total patients, the number of patients with ischemic stroke were 78.5 % while 8.3 % were of haemorrhagic type. In the results, the demographic characteristics and the factors which influence the formation of PU of the patients were examined with their cross-sectional impact on each other through comparative and statistical analysis. It was discovered that among all the stroke patients, 8.3 % were found with a PUs and the most frequent localization was sacrum and no new PU was observed for the participants under the observation.

Left ventricular unloading during venoarterial extracorporeal membrane oxygenation implantation: benefits or complications?

Abstract Funding Acknowledgements None. Introduction Peripheral venoarterial extracorporeal membrane oxygenation (VA ECMO) is a therapeutic option for refractory cardiogenic shock (CS). However, the retrograde flow increases afterload, leading to pulmonary edema, blood stasis in the left ventricle (LV) and formation of thrombi. Several strategies try to reduce LV pressure, including the percutaneous transvalvular microaxial pump (p-MCS) and intra-aortic balloon pump (IABP). However, these interventions are associated to complications, such as limb ischemia, embolism, bleeding and hemolysis. Purpose This study aims to investigate whether simultaneous LV unloading at ECMO implant yields clinical benefits or complications compared to ECMO implantat alone. Methods Consecutive patients (pts) with CS requiring peripheral VA ECMO from January 2020 to August 2023 were prospectively included, comparing the group that received LV unloading through IABP or p-MCS to the group that received ECMO only. Standard statistical methods were used. Results A total of 38 pts required VA ECMO. 18 of them received LV unloading since cannulation (8 with IABP and 10 with p-MCS). In the group without initial LV-unloading (20), 3 pts required IABP and 1 p-MCS during support and 1 was changed to VAV ECMO. Change to axillar configuration was perfomed in 1 pts in the unloaded group and in 2 in the only-ECMO group. A higher prevalence of SCAI E (72.2%) was observed in the unloaded-ECMO, compared to the only-ECMO, where SCAI D was more prevalent (60%) (p=0.024). In the LV unloaded group, acute myocardial infarction (AMI) was the leading cause of CS, while myocarditis was the predominant one in the other group (p=0.01). The simultaneous support had a higher rate of intubation (94.4% vs 50% p=0.004) and more acute pulmonary edema (44.4% vs 10% p=0.027). In the ECMO-only 2 pts required intubation during support and LV stasis was observed in 1, whereas no cases were reported in the LV-unloaded group (p=0.036). The mean PaO2/FiO2 during support were higher in the not unloaded group (284.54 vs 200.50 mmHg p=0.036), necessitating lower FiO2 levels (40.89 vs 61.47% p=0.003). In terms of complications, we included the 4 patients from the ECMO-only group who eventually required LV unloading in the unloaded-ECMO. There were no significant differences in the duration of support, in-hospital mortality, stroke, embolism, systemic and local bleeding, or hemolysis. Conclusions Pts with ECMO and LV unloading since cannulation debuted with more severe CS, more AMI as the underlying cause, higher rates of acute pulmonary edema, and intubation. Despite these challenges, they did not experience worse outcomes in terms of in-hospital mortality or ischemic and hemorrhagic events. Notably, 4 patients initially managed with ECMO eventually required subsequent LV unloading. Consequently, the simultaneous implantation of ECMO and a LV unloading device appears to be a reasonable alternative for select patients with a higher risk profile.