Brain-computer interface digital prescription for neurological disorders.

Neurological and psychiatric diseases can lead to motor, language, emotional disorder, and cognitive, hearing or visual impairment By decoding the intention of the brain in real time, the Brain-computer interface (BCI) can first assist in the diagnosis of diseases, and can also compensate for its damaged function by directly interacting with the environment; In addition, provide output signals in various forms, such as actual motion, tactile or visual feedback, to assist in rehabilitation training; Further intervention in brain disorders is achieved by close-looped neural modulation. In this article, we envision the future BCI digital prescription system for patients with different functional disorders and discuss the key contents in the prescription the brain signals, coding and decoding protocols and interaction paradigms, and assistive technology. Then, we discuss the details that need to be specially included in the digital prescription for different intervention technologies. The third part summarizes previous examples of intervention, focusing on how to select appropriate interaction paradigms for patients with different functional impairments. For the last part, we discussed the indicators and influencing factors in evaluating the therapeutic effect of BCI as intervention.

Uric acid mediated the relationship between obesity and hypertension in children and adolescents: A population­based cohort study.

BACKGROUND AND AIM: Obesity and hyperuricemia (HUA) often coexist and have been widely accepted as risk factors for hypertension, but the role of uric acid (UA) in the relationship between obesity and hypertension remains unknown in children and adolescents. METHODS AND RESULTS: A total of 7525 subjects aged 6-16 years were from the School-based Cardiovascular and Bone Health Promotion Program (SCVBH) at baseline (2017) and followed up in 2019. Multivariable logistic regression with interaction terms, cross-lagged panel analysis, and causal mediation model were applied to delineate the joint impact of obesity and HUA on hypertension, including the interaction effect, the temporal association, and the mediating effect of UA in the relationship between obesity and hypertension. There were 10.8 % of the participants with normotension at baseline developed hypertension after two years of follow-up. Cross-lagged panel analysis showed that the two-time point association was significant only from baseline BMI to follow-up UA (ß1 = 0.302, P < 0.001), but not from baseline UA to follow-up BMI (ß2 = 0.002, P = 0.745). Multivariable logistic regression showed that both obesity and HUA increased the risk of hypertension, but no interaction effect between HUA and obesity. The causal mediation analysis found that UA partially mediated the association between BMI and SBP (mediate proportion: 20.3 %, 95 % CI: 17.4-22.9 %) or DBP (mediate proportion: 11.9 %, 95 % CI: 3.9-18.2 %). The results were consistent in the analysis of systolic hypertension rather than diastolic hypertension. CONCLUSIONS: It is mediating effect that UA played in the progress from obesity to hypertension, particularly systolic hypertension in children and adolescents.

Prevalence of hypertension and its associations with body composition across Chinese and American children and adolescents.

BACKGROUND: The age of onset of hypertension (HTN) is decreasing, and obesity is a significant risk factor. The prevalence and racial disparities in pediatric HTN and the association between body composition and blood pressure are insufficiently studied. This study aimed to evaluate the prevalence of HTN in Chinese and American children and adolescents and to assess the relationship between various body composition indices and HTN. METHODS: Seven thousand, five hundred and seventy-three Chinese and 6239 American children and adolescents aged 8-18 years from the 2013-2015 China Child and Adolescent Cardiovascular Health study and the 2011-2018 National Health and Nutrition Examination Surveys were analyzed. Blood pressure and body composition (fat and muscle) were measured by trained staff. The crude prevalence and age-standardized prevalence rate (ASPR) of primary HTN and its subtypes [isolated systolic hypertension (ISH) and isolated diastolic hypertension (IDH)] were calculated based on 2017 American Academy of Pediatrics guidelines. Multivariable-adjusted linear regression coefficients and odds ratios (ORs) were calculated to assess the associations of body composition indicators with HTN, ISH and IDH. RESULTS: The ASPR of HTN was 18.5% in China (CN) and 4.6% in the United States (US), whereas the obesity prevalence was 7.4% and 18.6%, and the population attributable risk of HTN caused by overweight and obesity was higher in the US than in CN. Increased fat mass, muscle mass and body fat percentage mass were associated with a higher risk of HTN in both countries. The percent of muscle body mass had a protective effect on HTN and ISH in both countries [HTN (CN: OR = 0.83, 95% CI = 0.78-0.88; US: OR = 0.72, 95% CI = 0.64-0.81); ISH (CN: OR = 0.87, 95% CI = 0.80-0.94; US: OR = 0.71, 95% CI = 0.62-0.81)], and the protective effect was more common among children and adolescents with high levels of physical activity. CONCLUSIONS: The burden of HTN in Chinese children and adolescents was substantial and much greater than that in the US, and the contribution of obesity to HTN was higher in the US than in CN. Augmenting the proportion of muscle mass in body composition has a protective effect against HTN in both populations. Optimizing body composition positively influences blood pressure in children and adolescents, particularly those with high-level physical activity. Video abstract (MP4 149982 KB).

Difference of glucose and lipid metabolism abnormalities and body fat between the Chinese and USA teenagers.

Background: Comparing body fat and the effect of body fat on metabolic abnormalities in Chinese and USA teenagers may provide clues for the early prevention and control of cardiovascular disease (CVD). We aimed to compare the prevalence of glucose and lipid metabolism abnormalities, body fat amount and distribution, and the effect of body fat on glucose and lipid metabolism in Chinese and US teenagers. Methods: We included 5424 Chinese teenagers (48.5% male) from the China Child and Adolescent Cardiovascular Health (CCACH) study and 8704 USA teenagers (55.6% male) from the USA National Health and Nutrition Examination Survey (NHANES). Blood lipid, blood glucose, and body fat indicators were obtained using the same standardised measurements. Results: The prevalence of dyslipidaemia in Chinese teenagers was of those in the USA (hypercholesterolaemia = 3.5% vs 7.4%; high low-density lipoprotein cholesterol (LDL-C) = 3.6% vs 5.0%; low high-density lipoprotein cholesterol (HDL-C) = 9.9% vs 14.3%; hypertriglyceridaemia = 3.7% vs 10.1%) (P < 0.05). However, with the increase in body mass index (BMI), the prevalence of high LDL-C increased more in Chinese than in US teenagers, even exceeding them in the obese group (2.7% in non-overweight to 9.7% in overweight group in China, P < 0.05; 3.5% in non-overweight to 6.5% in the obese group in the USA, P < 0.05). The prevalence of impaired fasting glucose was higher in China than in the USA (28.0% vs 17.5%, P < 0.05). Besides, Chinese adolescents are more likely to accumulate fat in the abdomen, and the per-unit fat increase would bring a higher risk of dyslipidaemia in Chinese boys than in USA boys. Conclusions: Dyslipidaemia was more prevalent in US teenagers than in Chinese teenagers, but with the increase in BMI, the prevalence of high LDL-C increased more in Chinese than in US teenagers. Impaired fasting glucose (IFG) was significantly more prevalent in China than in the USA. The unfavoured body fat and higher risk of body fat on metabolic disorders in Chinese teenagers suggest that Chinese teenagers should pay more attention to the adverse effect of body fat on metabolic abnormalities.

Stiffness Optimal Modulation of a Variable Stiffness Energy Storage Hip Exoskeleton and Experiments on its Assistance Effect.

Lower limb energy storage assisted exoskeletons realize walking assistance by using the energy stored by elastic elements during walking. Such exoskeletons are characterized by a small volume, light weight and low price. However, energy storage assisted exoskeletons adopt fixed stiffness joints typically, which cannot adapt to changes of the wearer's height, weight, or walking speed. In this study, based on the analysis of the energy flow characteristics and stiffness change characteristics of lower limb joints during a human walking on flat ground, a novel variable stiffness energy storage assisted hip exoskeleton is designed, and a stiffness optimization modulation method is proposed to store most of the negative work done by the human hip joint when walking. Through the analysis of the surface electromyography signals of the rectus femoris and long head of the biceps femoris, it is found that the muscle fatigue of the rectus femoris is reduced by 8.5% under the optimal stiffness assistance condition, and the exoskeleton provides better assistance under the optimal stiffness assistance condition.

Overfat cutoffs and the optimal combination of body fat indices for detecting cardiometabolic risk among school-aged children.

OBJECTIVE: This study aimed to develop cutoffs and the optimal combination for body fat indices for screening cardiometabolic risk (CMR) among the pediatric population. METHODS: This cross-sectional study consisted of 8710 (50.3% boys) Chinese children aged 6 to 18 years. Body fat indices, including fat mass index (FMI), body fat percentage, trunk to leg fat ratio (TLR), and android to gynoid fat ratio, were derived from dual-energy x-ray absorptiometry scans. The area under the receiver operating characteristic curve was used to determine the best combination and optimal cutoffs of body fat indices to identify CMR. RESULTS: Compared with anthropometry-based obesity measures, i.e., BMI and waist circumference, the FMI + TLR combination presented statistically higher area under the receiver operating characteristic curve values for discriminating CMR and its clustering. The optimal overfat cutoffs of FMI and TLR were respectively determined at the 75th percentile in boys and at the 80th percentile of FMI and the 75th percentile of TLR in girls. Moreover, simplified thresholds derived from age-group-merged cutoffs showed similar performance as optimal cutoffs in detecting CMR. CONCLUSIONS: Both the optimal and simplified overfat cutoffs were provided for the Chinese pediatric population. The use of FMI and TLR together allows for adequate screening of CMR and its clustering.

Differences in air displacement plethysmography, bioelectrical impedance analysis and dual-energy X-ray absorptiometry for estimating body composition in Chinese children and adolescents.

AIM: This study aimed to compare body composition (BC) measurements obtained by three widely used BC measuring methods, air displacement plethysmography (ADP), bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA), in Chinese children and adolescents by sex and different BMI categories. METHODS: We used three BC measuring methods to evaluate healthy Chinese children and adolescents aged 5-17 years with BMI categories ranging from underweight to obese. Fat mass (FM, kg), fat mass percentage (FMP, %), fat-free mass (FFM, kg) and appendicular skeletal muscle mass (ASM, kg) were measured by DXA, BIA and ADP on the same day within 1 h. RESULTS: A total of 172 Chinese children and adolescents were included in this study. The agreements for FM, FFM and ASM estimated by the three methods were excellent or good at the population level (intraclass correlation coefficient > 0.850, P < 0.05). However, ADP or BIA estimated lower body fat content and higher FFM than DXA (P < 0.001 for all). Moreover, the precise estimates significantly varied across BMI categories. In addition, the limit of agreements was wide, and the differences might not be clinically acceptable at the individual level. CONCLUSIONS: Body fat and FFM obtained by the three commonly used methods were highly correlated, but systematically different and influenced by BMI. This study provided a basis for mutual reference of measurements between three widely used methods.

Stair-climbing wheelchair proven to maintain user's body stability based on AnyBody musculoskeletal model and finite element analysis.

The electric stair-climbing wheelchair is a beneficial mobile assistance device for older adults and disabled persons with poor walking ability, as it reduces the daily walking and climbing burden. In this paper, 11 older adults were tested when using a stair-climbing wheelchair in three environments: flat ground, slopes, and stairs. The kinematic and dynamic parameters of the lower limb joints were simulated by AnyBody 7.2 human model simulation software using Vicon 3D infrared motion capture, a 3D force table, and analyzed by ANSYS 19.2 Workbench. The joint force, joint moment, and muscle strength did not change significantly under the three environments when using the wheelchair. Through finite element analysis of the mechanical properties of the human body, when using the wheelchair, no significant differences in the overall stress distributions of the fifth lumbar spine, hip bone, or femur were found among the three environments, no significant differences in deformation and displacement were found, and the stress distribution was relatively stable. Therefore, the human body is stable enough to use the electric stair-climbing wheelchair in the three test environments, all of which will be commonly encountered in daily life.

Interference of unilateral lower limb amputation on motor imagery rhythm and remodeling of sensorimotor areas.

Purpose: The effect of sensorimotor stripping on neuroplasticity and motor imagery capacity is unknown, and the physiological mechanisms of post-amputation phantom limb pain (PLP) illness remain to be investigated. Materials and methods: In this study, an electroencephalogram (EEG)-based event-related (de)synchronization (ERD/ERS) analysis was conducted using a bilateral lower limb motor imagery (MI) paradigm. The differences in the execution of motor imagery tasks between left lower limb amputations and healthy controls were explored, and a correlation analysis was calculated between level of phantom limb pain and ERD/ERS. Results: The multiple frequency bands showed a significant ERD phenomenon when the healthy control group performed the motor imagery task, whereas amputees showed significant ERS phenomena in mu band. Phantom limb pain in amputees was negatively correlated with bilateral sensorimotor areas electrode powers. Conclusion: Sensorimotor abnormalities reduce neural activity in the sensorimotor cortex, while the motor imagination of the intact limb is diminished. In addition, phantom limb pain may lead to over-activation of sensorimotor areas, affecting bilateral sensorimotor area remodeling.

The associations of muscle mass with glucose and lipid metabolism are influenced by body fat accumulation in children and adolescents.

Objective: To evaluate the prevalence of hyperglycemia and dyslipidemia among different body composition and investigate the associations of body composition indicators, especially the muscle mass, with glucose and lipids metabolism in children and adolescents. Methods: This nationwide cross-sectional study included 8,905 children and adolescents aged 6 to 18 years. All participants underwent dual-energy x-ray absorptiometry and their blood-concentrated glucose and lipids (including TC, TG, LDL-C and HDL-c) were measured. Mixed model, hierarchical analysis, and piecewise regression were used to study the effect of body composition indicators, especially the muscle mass, on glucose and lipids metabolism. Results: The greatest prevalence of high total cholesterol (TC, 6.9% and 6.9%) and high triglyceride (22.3% and 6.6%) was found in both boys and girls with high muscle mass and high fat mass, and girls with high muscle mass and high fat mass also had the highest prevalence of hyperglycemia (7.1%). After fat stratification, higher muscle mass was associated with lower odds of hyperglycemia (OR = 0.62; 95%CI: 0.46,0.84; P = 0.002) and muscle mass was inversely associated with TC (ß = -0.07; 95%CI: -0.12,-0.03; P < 0.001) in boys with normal fat mass, but high muscle mass was not significantly associated with hyperglycemia and TC in high-fat-mass group (P = 0.368 and 0.372). Conclusions: The body composition phenotype of high muscle and high fat mass have the highest prevalence of dysglycemia and dyslipidemia. Higher muscle mass was associated with a lower risk of hyperglycemia and TC levels in individuals only with normal fat mass.

Differences in body composition measurements assessed by air displacement plethysmography and dual-energy X-ray absorptiometry in young and middle-aged adults.

BACKGROUND & OBJECTIVES: Dual-energy X-ray absorptiometry (DXA) and air displacement plethysmography (ADP) are two widely used methods for body composition analysis (BCA). However, little is known about the discrepancies in the results of BCA obtained from the two methods in Chinese population. This study aimed to compare the measurement differences between DXA and ADP in young and middle-aged Chinese adults, and to explore the influential factors of this difference. METHODS: A total of 186 healthy volunteers (51.1% males) who aged 18-56 years old with body mass index (BMI) of 15.9-35.9 kg/m2 were enrolled. Fat mass (FM), fat mass percentage (FMP), and fat-free mass (FFM) were analyzed by both DXA and ADP within 1 h. RESULTS: In general, all the BCA measures of DXA and ADP were highly correlated (intraclass correlation coefficient ICC>0.80, P < 0.001), while differences were found between the two methods (all P < 0.001). At the population level, greater body fat estimates (FM: 1.8 ± 3.1 kg in males and 2.2 ± 2.4 kg in females; FMP: 2.4 ± 4.2% in males and 3.1 ± 3.5% in females), whereas lower FFM (-0.2 ± 3.1 kg in males and -0.9 ± 2.4 kg in females) were found for DXA than ADP. Moreover, the average difference in FM and FMP as referred to ADP changed from positive in underweight group to negative in obesity group, and vice versa for FFM. At the individual level, the proportion of relative errors for FM and FMP within ±15% was less than 10% in underweight subjects and over 75% in those with obesity. For FFM, all underweight subjects had a relative error within 15%, and the proportion was 90.5% for obese males and 85.0% for obese females. CONCLUSION: BCA results by DXA and ADP were highly correlated, but the differences between the two methods were strongly influenced by BMI status at both population and individual levels. Caution should be especially taken when interchanging body fat results measured by the two methods in underweight and obese subjects.

Motor Imagery-Related Changes of Neural Oscillation in Unilateral Lower Limb Amputation.

An amputation is known to seriously affect patient quality of life. This study aimed to investigate changes in neural activity in amputees during the postoperative period using neural electrophysiological techniques. In total, 14 patients with left lower limb amputation and 18 healthy participants were included in our study. All participants were required to perform motor imagery paradigm tasks while electroencephalogram (EEG) data were recorded. Data analysis results indicated that the beta frequency band showed significantly decreased oscillatory activity in motor imaging-related brain regions such as the frontal lobe and the precentral and postcentral gyri in amputees. Furthermore, the functional independent component analysis (fICA) value of neural oscillation negatively correlated with the C4 electrode power value of the motor imagery task in amputees (p < 0.05). Therefore, changes in neural oscillations and beta frequency band in motor imagery regions may be related to brain remodeling in amputees.

Comparative proteomics and secretomics revealed virulence, and coresistance-related factors in non O1/O139 Vibrio cholerae recovered from 16 species of consumable aquatic animals.

Vibrio cholerae can cause pandemic cholera in humans. The bacterium resides in aquatic environments worldwide. Identification of risk factors of V. cholerae in aquatic products is imperative for assuming food safety. In this study, we determined virulence-associated genes, cross-resistance between antibiotics and heavy metals, and genome fingerprinting profiles of non O1/O139 V. cholerae isolates (n = 20) recovered from 16 species of consumable aquatic animals. Secretomes and proteomes of V. cholerae with distinct genotypes and phenotypes were obtained by using two-dimensional gel electrophoresis (2D-GE) and/or liquid chromatography-tandem mass spectrometry (LC-MS/MS) techniques. Comparative secretomic analysis revealed 4 common and 45 differential extracellular proteins among 20 V. cholerae strains, including 13 virulence- and 8 resistance-associated proteins. A total of 21,972 intracellular proteins were identified, and comparative proteomic analysis revealed 215 common and 913 differential intracellular proteins, including 22 virulence- and 8 resistance-associated proteins. Additionally, different secretomes and proteomes were observed between V. cholerae isolates of fish and shellfish origins. A number of novel proteins with unknown function and strain-specific proteins were also discovered in the V. cholerae isolates. SIGNIFICANCE: V. cholerae can cause pandemic cholera in humans. The bacterium is distributed in aquatic environments worldwide. Identification of risk factors of V. cholerae in aquatic products is imperative for assuming food safety. Non-O1/O139 V. cholerae has been reported to cause sporadic cholera-like diarrhea and bacteremia diseases, which indicates virulence factors rather than the major cholera toxin (CT) exist. This study for the first time investigated proteomes and secretomes of non-O1/O139 V. cholerae originating from aquatic animals. This resulted in the identification of a number of virulence and coresistance-related factors, as well as novel proteins and strain-specific proteins in V. cholerae isolates recovered from 16 species of consumable aquatic animals. These results fill gaps for better understanding of pathogenesis and resistance of V. cholerae, and also support the increasing need for novel diagnosis and vaccine targets against the leading waterborne pathogen worldwide.

Bone mineral density and its influencing factors in Chinese children with spinal muscular atrophy types 2 and 3.

BACKGROUND: Patients with spinal muscular atrophy (SMA) are at risk of decreased bone mineral density (BMD). The bone health status of Chinese patients with SMA has been poorly studied. We aimed to evaluate the BMD of children with SMA types 2 and 3 in mainland China and investigate its influencing factors. METHODS: Forty patients with a mean age of 5.5 years affected by SMA types 2 and 3 (n = 22 and n = 18, respectively) were enrolled between September 2017 and May 2019. Total body less head (TBLH) BMD, lumbar spine (LS) BMD, and body composition were measured using dual-energy X-ray absorptiometry (DXA). Serum bone metabolism markers and complete spinal radiographs were assessed. We utilized a linear regression model to explore the correlations between BMD and its related factors. RESULTS: A total of 67.5% (27/40) of patients were diagnosed with low BMD and 2.5% (1/40) were diagnosed with osteoporosis. The TBLH BMD and LS BMD Z-scores in children with SMA type 2 were significantly lower than those with SMA type 3. Both TBLH and LS BMD Z-scores tended to increase with the change of SMA subtypes from 2a-3b. Vitamin D insufficiency and deficiency were found in 37.5% (15/40) of the patients. Serum Ca, phosphorus (P), alkaline phosphatase (ALP) and parathormone (PTH) levels were normal. There were no significant differences among the four subtypes in terms of all the serum bone metabolism markers. Phenotype was significantly associated with TBLH BMD and LS BMD Z-scores, and serum PTH levels were significantly associated with TBLH BMD Z-scores. CONCLUSIONS: Low BMD and osteoporosis were highly prevalent in mainland Chinese children with SMA types 2 and 3. Phenotype and serum PTH level might be the influencing factors of BMD. Regular monitoring of BMD by DXA scan and taking active interventions aim to SMA children with different types are important.

Reference centiles for evaluating total body fat development and fat distribution by dual-energy x-ray absorptiometry among children and adolescents aged 3-18 years.

BACKGROUND & AIMS: The rise in the prevalence of childhood obesity has increased the demand for accurately evaluating body fatness in pediatric population. The aim of this study was to provide a series of sex- and age-specific body fat reference centiles for evaluating total body fat development and fat distribution in Chinese children and adolescents using dual-energy x-ray absorptiometry (DXA). METHODS: A nationwide sample of Chinese children and adolescents aged 3-18 years (n = 12,790) was drawn from a cross-sectional survey of the China Child and Adolescent Cardiovascular Health study (2013-2019). Fat measurements, including total fat mass index (FMI), total body fat percentage (BF%), regional FMI, trunk to leg (T/L) fat ratio and android to gynoid (A/G) fat ratio, were derived from whole body DXA scans. Sex- and age-specific centiles were estimated using the lambda-mu-sigma method and then compared with values derived from the US National Health and Nutrition Examination Survey (1999-2004) and Korean National Health and Nutrition Examination Survey (2008-2011). RESULTS: During early childhood, almost all body fat parameters decreased with age, except an increase in A/G ratio. After 7 years onward, drastic upward trends of total FMI and BF% were exhibited in boys till 10 years, followed by opposite downward trends during 11-14 years; while sustained increase of FMI was shown in girls across ages accompanied by relatively constant BF% levels. Meanwhile, steady increases were noticed for A/G ratio and T/L ratio, which were more pronounced in boys. In addition, the proposed body fat references were much lower than the US but similar to Koreans despite of subtle differences. CONCLUSIONS: This is the first study to present a set of DXA-based body fat reference for Chinese children and adolescents aged 3-18 years. The new reference provides clinicians and researchers a useful tool for assessing body fat development and distribution patterns throughout early childhood and adolescence.

Altered cortical activity in patients with lower limb amputation based on EEG microstate.

Previous studies have revealed significant changes in electroencephalogram (EEG) microstates in neuropsychiatric diseases, including schizophrenia, depression, and dementia. To explore the resting-state EEG microstate with amputation, we collected the EEG datasets from 15 patients with lower limb amputation and 20 healthy controls. Then, we analyzed the parameters of four classical EEG microstates (A-D) between the two groups. Specifically, the parameters were statistically analyzed, including duration, occurrence rate, time coverage, and transition rate. According to the results, the duration of microstate C (t = 2.95, p = 0.005) in the lower limb amputation group was significantly smaller compared with the control group, while the occurrence rate of microstate B (t = -2.22, p = 0.03) and D (t = -3.35, p = 0.002) were significantly larger in the lower limb amputation group. In addition, the transition rate of microstate differed significantly in AC, CA, DB between the two groups. Our results implied: (1) amputation has changed the resting-state EEG microstate; (2) EEG microstate analysis can be an approach to explore the alteration of cortical function.

Executive Control, Alerting, Updating, and Falls in Cognitively Healthy Older Adults.

BACKGROUND: Cognitive impairment represents a risk factor for falls in older adults. However, cognition is a complex construct comprising several functional domains. The relationship between specific cognitive domain and falls in cognitively healthy older adults is unclear. OBJECTIVES: This study aims to investigate the relationship between falls, attention, and executive function in older adults while considering the three components of attention (alerting, orienting, and executive control) and three components of executive function (updating, inhibition, and shifting). METHODS: Cognitively healthy older adults were recruited (n = 60 for fallers and n = 100 for non-fallers). The participants were assessed on the Attention Network Test (alerting, orienting, and executive control), running memory test (updating), Stroop test (inhibition), and digit switching test (shifting). Confounder-adjusted logistic models were used to examine the associations between falls and specific cognitive functions in cognitively healthy older adults. RESULTS: The results showed that falls were associated with alerting, executive control, and updating. These associations were not attenuated when adjusting for a series of covariates such as age, gender, education, balance, general health, and emotional status. CONCLUSIONS: The results suggest that among cognitively healthy older adults, falls are related to three specific cognitive functions: alerting, executive control, and updating. Disentangling the mechanism and contribution of cognitive deficits in fall risk may provide insights for the development of prevention and rehabilitation strategies for falls in older adults.

Study of helical flow inducers with different thread pitches and diameters in vena cava.

Pulmonary embolism is a severe, potentially life-threatening condition. Inferior vena cava filters have been used to prevent recurrent pulmonary embolisms. However, the build-up of thrombosis in vena cava filters after deployment presents a severe problem to patients. Previous studies proposed that filters with helical flow are beneficial and capable of alleviating this problem. In this study, the hemodynamic performances of four typical helical flow inducers in the vena cava are determined using computational fluid dynamics simulations (steady-state and pulsatile flow) and compared. Pilot in vitro experiments were also conducted. The simulation results demonstrate that large-diameter inducers produce helical flow. Among inducers with identical diameter, those with a smaller thread pitch are more likely to induce increased helical flow. We also observed that the small thread pitch inducers can yield higher shear rates. Furthermore, a large diameter, small thread pitch helical flow inducer increases the time-averaged wall shear stress and reduces the oscillating shear index and relative residence time on the vessel wall in the vicinity of the helical flow inducer. In vitro experiments also verify that large diameter inducers generate a helical flow. A notable observation of this study is that the diameter is the key parameter that affects the induction of a helical flow. This study will likely provide important guidance for the design of interventional treatments and the deployment of filters associated with helical flow in the vena cava.