Classification of chemically modified red blood cells in microflow using machine learning video analysis.

We classify native and chemically modified red blood cells with an AI based video classifier. Using TensorFlow video analysis enables us to capture not only the morphology of the cell but also the trajectories of motion of individual red blood cells and their dynamics. We chemically modify cells in three different ways to model different pathological conditions and obtain classification accuracies for all three classification tasks of more than 90% between native and modified cells. Unlike standard cytometers that are based on immunophenotyping our microfluidic cytometer allows to rapidly categorize cells without any fluorescence labels simply by analysing the shape and flow of red blood cells.

Acoustic erythrocytometer for mechanically probing cell viscoelasticity.

We demonstrate an acoustic device to mechanically probe a population of red blood cells at the single cell level. The device operates by exciting a surface acoustic wave in a microfluidic channel creating a stationary acoustic wave field of nodes and antinodes. Erythrocytes are attracted to the nodes and are deformed. Using a stepwise increasing and periodically oscillating acoustic field we study the static and dynamic deformation of individual red blood cells one by one. We quantify the deformation by the Taylor deformation index D and relaxation times τ1 and τ2 that reveal both the viscous and elastic properties of the cells. The precision of the measurement allows us to distinguish between individual cells in the suspension and provides a quantitative viscoelastic fingerprint of the blood sample at single cell resolution. The method overcomes limitations of other techniques that provide averaged values and has the potential for high-throughput.

In training for a marathon: Runners and running-related injury prevention.

OBJECTIVE: To investigate which preventive measures runners use when preparing for a half- or full-marathon and whether the use of these measures at baseline and during the preparation-period differs between runners who sustained no/non-substantial running-related injuries (NSIRs) or substantial running-related injuries (SIRs). DESIGN: Prospective cohort study. SETTING: 16-week period before the Utrecht Marathon. PARTICIPANTS: Runners who subscribed for the half- or full-marathon. MAIN OUTCOME MEASURES: The occurrence of RRIs was registered every 2-weeks, using the Dutch version of the Oslo Sport Trauma Research Center (OSTRC) questionnaire on Health Problems. The OSTRC was used to differentiate between runners with SIRs (question 2/3 score>12) and NSIRs (question 2/3 score<13). The use of different preventive measures, was registered every 4-weeks. RESULTS: 51.6% of the runners reported at least one RRI in the 12-months prior to this study (history of RRIs). The SIRs with a history of RRIs more often asked for running shoe advice than NSIRs with a history of RRIs (67.9%vs43.4%, P < 0.05); 18.9% of the SIRs with a history of RRIs used supportive materials for knee and/or ankle versus 0% of NSIRs with a history of RRIs (P < 0.05). CONCLUSION: SIRs with a history of RRIs might be using their preventive measures for symptom reduction or secondary prevention.

Traveling surface acoustic wave (TSAW) microfluidic fluorescence activated cell sorter (µFACS).

We report a microfluidic fluorescence activated cell-sorting (µFACS) device that employs traveling surface acoustic waves (TSAW) to sort cells at rates comparable to conventional jet-in-air FACS machines, with high purity and viability. The device combines inertial flow focusing and sheath flow to align and evenly space cells, improving the sorting accuracy and screening rate. We sort with an interdigital transducer (IDT) whose tapered geometry allows precise positioning of the TSAW for optimal cell sorting. We sort three different cell lines at several kHz, at cell velocities exceeding one meter per second, while maintaining both sorting purity and cell viability at around 90% simultaneously.

Binary Colloidal Nanoparticle Concentration Gradients in a Centrifugal Field at High Concentration.

Binary colloidal nanoparticles have been found to form different types of crystalline phases at varied radial positions in a centrifugal field by Chen et al. ( ACS Nano 2015, 9, 6944-50). The variety of binary phase behaviors resulted from the two different nanoparticle concentration gradients, but to date, the gradients can only be empirically controlled. For the first time, we are able to measure, fit, and simulate binary hard-sphere colloidal nanoparticle concentration gradients at high particle concentrations up to 30 vol %, which enables tailor-made gradients in a centrifugal field. By this means, a continuous range of binary particle concentration ratios can be accessed in one single experiment to obtain an extended phase diagram. By dispersing two differently sized silica nanoparticles labeled with two different fluorescence dyes in a refractive index matching solvent, we can use a multi-wavelength analytical ultracentrifuge (MWL-AUC) to measure the individual concentration gradient for each particle size in sedimentation-diffusion equilibrium. The influence of the remaining slight turbidity at high concentration can be corrected using the MWL spectra from the AUC data. We also show that the experimental concentration gradients can be fitted using a noninteracting nonideal sedimentation model. By using these fitted parameters, we are able to simulate nanoparticle concentration gradients, which agreed with the subsequent experiments at a high concentration of 10 vol % and thus allowed for the simulation of binary concentration gradients of hard-sphere nanoparticles in preparative ultracentrifuges (PUCs). Finally we demonstrated that by simulating the concentration gradients in PUCs, a continuous and extended binary nanoparticle phase diagram can be obtained by simply studying the structure evolution along the centrifugal field for one single sample instead of a large number of experiments with discrete compositions as in conventional studies.

Bimorph material/structure designs for high sensitivity flexible surface acoustic wave temperature sensors.

A fundamental challenge for surface acoustic wave (SAW) temperature sensors is the detection of small temperature changes on non-planar, often curved, surfaces. In this work, we present a new design methodology for SAW devices based on flexible substrate and bimorph material/structures, which can maximize the temperature coefficient of frequency (TCF). We performed finite element analysis simulations and obtained theoretical TCF values for SAW sensors made of ZnO thin films (~5 µm thick) coated aluminum (Al) foil and Al plate substrates with thicknesses varied from 1 to 1600 µm. Based on the simulation results, SAW devices with selected Al foil or plate thicknesses were fabricated. The experimentally measured TCF values were in excellent agreements with the simulation results. A normalized wavelength parameter (e.g., the ratio between wavelength and sample thickness, λ/h) was applied to successfully describe changes in the TCF values, and the TCF readings of the ZnO/Al SAW devices showed dramatic increases when the normalized wavelength λ/h was larger than 1. Using this design approach, we obtained the highest reported TCF value of -760 ppm/K for a SAW device made of ZnO thin film coated on Al foils (50 µm thick), thereby enabling low cost temperature sensor applications to be realized on flexible substrates.

Enhanced surface acoustic wave cell sorting by 3D microfluidic-chip design.

We demonstrate an acoustic wave driven microfluidic cell sorter that combines advantages of multilayer device fabrication with planar surface acoustic wave excitation. We harness the strong vertical component of the refracted acoustic wave to enhance cell actuation by using an asymmetric flow field to increase cell deflection. Precise control of the 3-dimensional flow is realized by topographical structures implemented on the top of the microchannel. We experimentally quantify the effect of the structure dimensions and acoustic parameter. The design attains cell sorting rates and purities approaching those of state of the art fluorescence-activated cell sorters with all the advantages of microfluidic cell sorting.

Visualization of Surface Acoustic Waves in Thin Liquid Films.

We demonstrate that the propagation path of a surface acoustic wave (SAW), excited with an interdigitated transducer (IDT), can be visualized using a thin liquid film dispensed onto a lithium niobate (LiNbO3) substrate. The practical advantages of this visualization method are its rapid and simple implementation, with many potential applications including in characterising acoustic pumping within microfluidic channels. It also enables low-cost characterisation of IDT designs thereby allowing the determination of anisotropy and orientation of the piezoelectric substrate without the requirement for sophisticated and expensive equipment. Here, we show that the optical visibility of the sound path critically depends on the physical properties of the liquid film and identify heptane and methanol as most contrast rich solvents for visualization of SAW. We also provide a detailed theoretical description of this effect.

[Medical operations at the 2010 love parade in Duisburg]. / Medizinischer Einsatz bei der Loveparade 2010 in Duisburg.

On 24 July 2010 the love parade, a large scale open air concert was held in the city of Duisburg to which more than 500,000 guests were expected. During the course of the early evening a major tragic incident occurred in which 21 people were crushed to death and several hundred others were injured. In this article the preparation of the emergency and rescue services prior to the event is described and their operations entailing more than 1,600 staff members from all over Germany are illustrated. The article focuses on the mass casualty incident which took place in the tunnel in the early evening of that day.

Optical imaging of concealed brain activity using a gold mirror in honeybees.

Brain activity is inherently combinatorial and three-dimensional. Optical imaging techniques offer a suitable opportunity to record many activity foci simultaneously, but under conventional microscopy conditions, optical access is generally limited to the frontal part of the brain. Thus, even for cases in which optical recordings have delivered substantial data, our knowledge of deeper layers is deficient. Using the honeybee olfactory system as a test system, we report that by using a gold-sputtered cover slip as a minute mirror, it is possible to optically access and record from otherwise inaccessible brain areas. In insects, the first brain area to code for odors is the antennal lobe (comparable to the vertebrate olfactory bulb). Several previous studies have characterized glomerular odor response patterns of the frontal view, readily accessible when the head capsule of the bee is opened. However, until now, the back and the sides of the antennal lobe have remained utterly unexplored. This is particularly relevant because in the honeybee these two views coincide with two separate olfactory subsystems, related to two axonal tracts of second-order neurons: the lAPT and the mAPT. Combining wide-field microscopy, calcium imaging, and a minute mirror, we report the first glomerular odor responses from the side of the honeybee antennal lobe.

Dynamics of red blood cells and vesicles in microchannels of oscillating width.

We have studied the dynamics of red blood cells and fluid lipid vesicles in hydrodynamic flow fields created by microchannels with periodically varying channel width. For red blood cells we find a transition from a regime with oscillating tilt angle and fixed shape to a regime with oscillating shape with increasing flow velocity. We have determined the crossover to occur at a critical ratio L(y)/v(m) ≈ 2.2 × 10⁻³ s with channel width L(y) and red blood cell velocity v(m). These oscillations are superposed by shape transitions from a discocyte to a slipper shape at low velocities and a slipper to parachute transition at high flow velocities.

[The social city and the elderly]. / Soziale Stadt und ältere Menschen.

Despite the importance of the idea of accommodation and the elderly, this group is currently not the main focus of the "Socially Integrative City" (Soziale Stadt) program. From the perspective of this important target group, housing and the living environment, local supply, mobility, health promotion, and the integration of immigrants are important fields of action that should be further considered. This requires, above all, involving the elderly in planning and implementation of projects and measures for integrated neighborhood development by intense activation and participation. In addition, local partnerships between government, social and health services, housing associations, business and local initiatives (clubs, self-help organizations) are prerequisite for successful development neighborhood.

Surface acoustic wave actuated cell sorting (SAWACS).

We describe a novel microfluidic cell sorter which operates in continuous flow at high sorting rates. The device is based on a surface acoustic wave cell-sorting scheme and combines many advantages of fluorescence activated cell sorting (FACS) and fluorescence activated droplet sorting (FADS) in microfluidic channels. It is fully integrated on a PDMS device, and allows fast electronic control of cell diversion. We direct cells by acoustic streaming excited by a surface acoustic wave which deflects the fluid independently of the contrast in material properties of deflected objects and the continuous phase; thus the device underlying principle works without additional enhancement of the sorting by prior labelling of the cells with responsive markers such as magnetic or polarizable beads. Single cells are sorted directly from bulk media at rates as fast as several kHz without prior encapsulation into liquid droplet compartments as in traditional FACS. We have successfully directed HaCaT cells (human keratinocytes), fibroblasts from mice and MV3 melanoma cells. The low shear forces of this sorting method ensure that cells survive after sorting.

PI3K/Akt: getting it right matters.

The Akt serine/threonine kinase (also called protein kinase B) has emerged as a critical signaling molecule within eukaryotic cells. Significant progress has been made in clarifying its regulation by upstream kinases and identifying downstream mechanisms that mediate its effects in cells and contribute to signaling specificity. Here, we provide an overview of present advances in the field regarding the function of Akt in physiological and pathological cell function within a more generalized framework of Akt signal transduction. An emphasis is placed on the involvement of Akt in human diseases ranging from cancer to metabolic dysfunction and mental disease.

Astrocyte elevated gene-1 activates cell survival pathways through PI3K-Akt signaling.

Astrocyte elevated gene-1 (AEG-1) displays oncogenic properties. Its expression is elevated in diverse neoplastic states and it cooperates with Ha-ras to promote cellular transformation. Overexpression of AEG-1 augments invasion and anchorage-independent growth of transformed cells, while AEG-1 siRNA inhibits Ha-ras-mediated colony formation, supporting a potential functional role in tumorigenesis. Additionally, oncogenic Ha-ras induces AEG-1 expression through the phosphatidylinositol 3-kinase (PI3K)-Akt signaling pathway. In the present study, we investigated whether AEG-1 could induce serum-independent cell growth, another property of oncogenes. Overexpression of AEG-1 inhibited serum starvation-induced apoptosis through activation of PI3K-Akt signaling, one of the effector pathways induced by activated Ras. AEG-1 also affected the phosphorylation state of Akt substrates that are implicated in apoptosis suppression, including glycogen synthase kinase 3beta, c-Myc, murine double minute 2, p53, p21/mda-6 and Bad. Additionally, AEG-1 blocked the activity of serum starvation-induced caspases. Taken together, these observations provide evidence that AEG-1 is an oncogene cooperating with Ha-ras as well as functioning as a downstream target gene of Ha-ras and may perform a central role in Ha-ras-mediated carcinogenesis. Activation of survival pathways may be one mechanism by which AEG-1 exerts its oncogenic properties.

Analyzing the content of outcome measures in clinical trials on irritable bowel syndrome using the international classification of functioning, disability and health as a reference.

BACKGROUND: Patients with irritable bowel syndrome (IBS) report a significant impact of their symptoms on functional health. In outcome assessment of clinical studies on IBS, however, functional aspects other than gastrointestinal symptoms seem to be disregarded to a great extent. AIM: To analyze the content of outcome measures used in clinical IBS trials. METHODS: A systematic review was performed in terms of a quantitative content analysis using the International Classification of Functioning, Disability and Health (ICF) as a coding scheme. Outcome measures were selected from all randomized controlled trials on IBS published in PubMed from the beginning to April 2002. From the outcome measures pre-specified text passages, so-called coding units, were extracted and linked to the ICF. A coding unit had to describe a single health aspect or an internal or external factor with an impact on health. If the outcome measure was a test the goal of the test was semantically implicated. Only second-level ICF categories contained in the outcome assessment of at least 10 % of the studies were considered. All steps of the review were performed by three independent raters. RESULTS: 99 studies were included. Single items were used as outcome measures in 88, clinical and paraclinical tests in 42 and questionnaires in 24 studies. Ninety percent of the coding units (n = 2271) could be linked to the ICF. ICF categories describing gastrointestinal symptoms were considered in the outcome assessment of 37 to 85 studies depending on the type of content compared to extra-gastrointestinal symptoms in 10 to 22 studies. Health information of ICF components other than "body functions" was scarcely included. Clear secular trends for individual ICF categories could not be found. Only a single IBS-specific questionnaire considered health information other than gastrointestinal symptoms. DISCUSSION AND CONCLUSION: Outcome assessment of clinical IBS studies is mainly based on gastrointestinal symptoms. The assessment of other health aspects like comorbid psychological symptoms or social consequences of the disease seems to be similarly important and should be considered in future trials. This would also facilitate the understanding of IBS as a biopsychosocial health condition, both in matters of aetiology and consequences.

The AKT kinase is activated in multiple myeloma tumor cells.

Immunohistochemistry (IHC) was performed on archived bone marrow (BM) with a phosphospecific anti-AKT antibody. IHC on 26 BM biopsies from patients with multiple myeloma (MM) demonstrated phospho-AKT staining of malignant plasma cells in a cell membrane-specific pattern, whereas nonmalignant hematopoietic cells did not stain. Preabsorption of the antibody with phosphorylated AKT peptide, but not nonphosphorylated peptide, abrogated staining. Frequency of plasma cell staining in BMs of patients with stage I or smoldering MM was significantly less than that of stage III MM marrows. Plasma cells in 10 patients with monoclonal gammopathy of undetermined significance were not stained by the antibody. To investigate the significance of AKT activation, 2 cell lines initiated from cultures of primary MM cells were also studied. Both demonstrated constitutive AKT activation. Interruption of AKT activation and activity, achieved by either exposure to wortmannin or by ectopic expression of a dominant negative AKT mutant, resulted in inhibition of MM cell growth in vitro. These results indicate that activation of the AKT kinase is a characteristic of MM cells and suggest that AKT activity is important for MM cell expansion.

Raf-MEK-Erk cascade in anoikis is controlled by Rac1 and Cdc42 via Akt.

Signals from the extracellular matrix are essential for the survival of many cell types. Dominant-negative mutants of two members of Rho family GTPases, Rac1 and Cdc42, mimic the loss of anchorage in primary mouse fibroblasts and are potent inducers of apoptosis. This pathway of cell death requires the activation of both the p53 tumor suppressor and the extracellular signal-regulated mitogen-activated protein kinases (Erks). Here we characterize the proapoptotic Erk signal and show that it differs from the classically observed survival-promoting one by the intensity of the kinase activation. The disappearance of the GTP-bound forms of Rac1 and Cdc42 gives rise to proapoptotic, moderate activation of the Raf-MEK-Erk cascade via a signaling pathway involving the kinases phosphatidlyinositol 3-kinase and Akt. Moreover, concomitant activation of p53 and inhibition of Akt are both necessary and sufficient to signal anoikis in primary fibroblasts. Our data demonstrate that the GTPases of the Rho family control three major components of cellular signal transduction, namely, p53, Akt, and Erks, which collaborate in the induction of apoptosis due to the loss of anchorage.