Initial spreading of low-viscosity drops on partially wetting surfaces

Liquid drops start spreading directly after brought into contact with a partial wetting substrate. Although this phenomenon involves a three-phase contact line, the spreading motion is very fast. We study the initial spreading dynamics of low-viscosity drops, using two complementary methods: Molecular Dynamics simulations and high-speed imaging. We access previously unexplored length- and time-scales, and provide a detailed picture on how the initial contact between the liquid drop and the solid is established. Both methods unambiguously point towards a spreading regime that is independent of wettability, with the contact radius growing as the square root of time

The influence of the reciprocal cable linkage in the advanced reciprocating gait orthosis on paraplegic gait performance

A wide variety of mechanical orthoses is available to provide ambulation to paraplegic patients. Evaluation of energy cost during walking in each of these devices has been acknowledged as an important topic in this field of research. In order to investigate the benefits of a ballistic swing on gait performance in the Advanced Reciprocating Gait Orthosis (ARGO) a study was conducted in which the ARGO was compared with an orthosis with freely swinging legs. This Non Reciprocally linked Orthosis (NRO) was obtained by removing the reciprocal linkage in the subjects' own ARGOs. Subsequently, flexion/extension limits were mounted to permit adjustment of stride length. Six male paraplegic subjects with lesions ranging from T4 to T12 were included in the study. A single case experimental design (B-A-B-A) was conducted in order to improve internal validity. Biomechanical and physiological parameters were assessed and the subjects' preference for either ARGO or NRO was determined.\ud \ud It was found that large inter-individual differences produced insufficient evidence in this study to draw general conclusions about difference in energy expenditure between both orthoses. However, individual analysis of the results showed a reduction of oxygen cost (range: 4%-14%) in the NRO in T9 and T12 lesions, while oxygen cost in subjects with T4 lesions increased markedly (22% and 40%). It is concluded that patients with low level lesions could benefit in terms of oxygen lost from removing the reciprocal cable linkage in the ARGO. However, only one subject preferred the NRO for walking, whereas none of the subject chose the NRO for use in daily living activities. Removal of the reciprocal cable linkage in the ARGO may not be desirable for these patients

The influence of frontal alignment in the advanced reciprocating gait orthosis on energy cost and crutch force requirements during paraplegic gait

Reduction of energy cost and upper body load during paraplegic walking is considered to be an important criterion in future developments of walking systems. A high energy cost limits the maximum walking distance in the current devices, whereas wrist and shoulder pathology can deteriorate because of the high upper body load. A change in alignment of the mechanical brace in the frontal plane, i.e. abduction, can contribute to a more efficient gait pattern with sufficient foot clearance with less pelvic lateral sway. A decrease in pelvic lateral sway after aligning in abduction results in a shift of the centre of mass to the swing leg crutch which may result in a decrease in required crutch force on stance side to maintain foot clearance. Five paraplegic subjects were provided with a standard Advanced Reciprocating Gait Orthosis (ARGO) and an ARGO aligned in 4 different degrees of abduction (0°, 3°, 6° and 9°). After determining an optimal abduction angle for each of the subjects, a cross over design was used to compare the ARGO with the individually optimised abducted orthosis. An abduction angle between 0° and 3° was chosen as optimal abduction angle. Subjects were not able to walk satisfactory with abduction angles 6° and 9°. A significant reduction in crutch peak force on stance side was found (approx. 12% , p < 0.01) in the abducted orthosis. Reduction in crutch force time integral (15%) as well as crutch peak force on swing side (5%) was not significant. No differences in oxygen uptake as well as oxygen cost was found. We concluded that an abduction angle between 0° and 3° is beneficial with respect to upper boHy load, whereas energy requirements did not change

Biomethanol from Glycerol

Medical bioinformatic

The influence of the reciprocal hip joint link in the advanced reciprocating gait orthosis on standing performance in paraplegia

The effect of reciprocally linking the hip hinges of a hip-knee-ankle-foot orthosis on standing performance was studied in a comparative trial of the Advanced Reciprocating Gait Orthosis (ARGO) and an ARGO in which the Bowden cable was removed (A_GO). Six male subjects with spinal cord injury (SCI) at T4 to T12 level participated in the study, which was conducted using a single case experimental design. Standing balance, the ability to handle balance disturbances (standing stability), and the performance of a functional hand task during standing were assessed in both orthosis configurations in the order A_GO-ARGO-A_GO-ARGO. No significant differences with respect to standing performance were found for the two orthosis configurations. However, the results indicate that the crutch force needed for maintaining balance during various tasks, especially for quiet standing with two crutches, may be much higher in the orthosis without Bowden cable. Therefore, it is very likely that the reciprocal hip joint link in the ARGO provides a substantial and clinically relevant reduction of upper body effort required for standing under functional conditions

Diet-induced gene expression of isolated pancreatic islets from a polygenic mouse model of the metabolic syndrome

AIMS/HYPOTHESIS: Numerous new genes have recently been identified in genome-wide association studies for type 2 diabetes. Most are highly expressed in beta cells and presumably play important roles in their function. However, these genes account for only a small proportion of total risk and there are likely to be additional candidate genes not detected by current methodology. We therefore investigated islets from the polygenic New Zealand mouse (NZL) model of diet-induced beta cell dysfunction to identify novel genes and pathways that may play a role in the pathogenesis of diabetes. METHODS: NZL mice were fed a diabetogenic high-fat diet (HF) or a diabetes-protective carbohydrate-free HF diet (CHF). Pancreatic islets were isolated by laser capture microdissection (LCM) and subjected to genome-wide transcriptome analyses. RESULTS: In the prediabetic state, 2,109 islet transcripts were differentially regulated (>1.5-fold) between HF and CHF diets. Of the genes identified, 39 (e.g. Cacna1d, Chd2, Clip2, Igf2bp2, Dach1, Tspan8) correlated with data from the Diabetes Genetics Initiative and Wellcome Trust Case Control Consortium genome-wide scans for type 2 diabetes, thus validating our approach. HF diet induced early changes in gene expression associated with increased cell-cycle progression, proliferation and differentiation of islet cells, and oxidative stress (e.g. Cdkn1b, Tmem27, Pax6, Cat, Prdx4 and Txnip). In addition, pathway analysis identified oxidative phosphorylation as the predominant gene-set that was significantly upregulated in response to the diabetogenic HF diet. CONCLUSIONS/INTERPRETATION: We demonstrated that LCM of pancreatic islet cells in combination with transcriptional profiling can be successfully used to identify novel candidate genes for diabetes. Our data strongly implicate glucose-induced oxidative stress in disease progression

Space-time analytics of human physiology for urban planning.

Recent advancements in mobile sensing and wearable technologies create new opportunities to improve our understanding of how people experience their environment. This understanding can inform urban design decisions. Currently, an important urban design issue is the adaptation of infrastructure to increasing cycle and e-bike use. Using data collected from 12 cyclists on a cycle highway between two municipalities in The Netherlands, we coupled location and wearable emotion data at a high spatiotemporal resolution to model and examine relationships between cyclists' emotional arousal (operationalized as skin conductance responses) and visual stimuli from the environment (operationalized as extent of visible land cover type). We specifically took a within-participants multilevel modeling approach to determine relationships between different types of viewable land cover area and emotional arousal, while controlling for speed, direction, distance to roads, and directional change. Surprisingly, our model suggests ride segments with views of larger natural, recreational, agricultural, and forested areas were more emotionally arousing for participants. Conversely, segments with views of larger developed areas were less arousing. The presented methodological framework, spatial-emotional analyses, and findings from multilevel modeling provide new opportunities for spatial, data-driven approaches to portable sensing and urban planning research. Furthermore, our findings have implications for design of infrastructure to optimize cycling experiences

Treatment of iron deficiency in patients scheduled for pancreatic surgery:implications for daily prehabilitation practice in pancreatic surgery

BACKGROUND: Preoperative anemia is a frequent complication in pancreatic surgical patients, and it adversely affects morbidity, mortality, and postoperative red blood cell (RBC) transfusion rates. Iron deficiency (ID) is often the underlying cause of anemia and constitutes a modifiable risk factor.METHODS: Single-center, longitudinal prospective cohort study conducted between May 2019 and August 2022 at the University Medical Center Groningen in the Netherlands. Patients scheduled for pancreatic surgery were referred to the outpatient prehabilitation clinic for preoperative optimization of patient-related risk factors. Patients were screened for anemia (&lt; 12.0 g/dL in women and &lt; 13.0 g/dL in men) and ID (either absolute [ferritin &lt; 30 µg/L] or functional [ferritin ≥ 30 µg/L + transferrin saturation &lt; 20% + C-reactive protein &gt; 5 mg/L]). Intravenous iron supplementation (IVIS) (1,000 mg ferric carboxymaltose) was administered to patients with ID at the discretion of the consulting internist. Pre- and postoperative hemoglobin (Hb) levels were assessed, and perioperative outcomes were compared between patients receiving IVIS (IVIS-group) or standard care (SC-group).RESULTS: From 164 screened patients, preoperative anemia was observed in 55 (33.5%) patients, and in 23 (41.8%) of these patients, ID was the underlying cause. In 21 patients, ID was present without concomitant anemia. Preoperative IVIS was administered to 25 patients, out of 44 patients with ID. Initial differences in mean Hb levels (g/dL) between the IVIS-group and SC-group at the outpatient clinic and one day prior to surgery (10.8 versus 13.2, p &lt; 0.001, and 11.8 versus 13.4, p &lt; 0.001, respectively) did not exist at discharge (10.6 versus 11.1, p = 0.13). Preoperative IVIS led to a significant increase in mean Hb levels (from 10.8 to 11.8, p = 0.03). Fewer SSI were observed in the IVIS-group (4% versus 25.9% in the SC-group, p = 0.02), which remained significant in multivariable regression analysis (OR 7.01 (1.68 - 49.75), p = 0.02).CONCLUSION: ID is prevalent in patients scheduled for pancreatic surgery and is amendable to preoperative correction. Preoperative IVIS increased Hb levels effectively and reduced postoperative SSI. Screening and correction of ID is an important element of preoperative care and should be a standard item in daily prehabilitation practice.</p

Alzheimer's disease pathology:pathways between central norepinephrine activity, memory, and neuropsychiatric symptoms

The locus coeruleus (LC) supplies norepinephrine to the brain, is one of the first sites of tau deposition in Alzheimer's disease (AD) and modulates a variety of behaviors and cognitive functions. Transgenic mouse models showed that norepinephrine dysregulation after LC lesions exacerbates inflammatory responses, blood-brain barrier leakage (BBB), and cognitive deficits. Here, we investigated relationships between central norepinephrine metabolism, tau and beta-amyloid (Aβ), inflammation, BBB-dysfunction, neuropsychiatric problems, and memory in-vivo in a memory clinic population (total n = 111, 60 subjective cognitive decline, 36 mild cognitively impaired, and 19 AD dementia). Cerebrospinal fluid (CSF) and blood samples were collected and analyzed for 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG), CSF/plasma albumin ratio (Q-alb), Aβ, phosphorylated tau, and interleukins. The verbal word learning task and the neuropsychiatric inventory assessed memory functioning and neuropsychiatric symptoms. Structural equation models tested the relationships between all fluid markers, cognition and behavior, corrected for age, education, sex, and clinical dementia rating score. Our results showed that neuropsychiatric symptoms show strong links to both MHPG and p-tau, whereas memory deficits are linked to MHPG via a combination of p-tau and inflammation-driven amyloidosis (30-35% indirect effect contribution). These results suggest that the LC-norepinephrine may be pivotal to understand links between AD pathology and behavioral and cognitive deficits in AD