Is objective and accurate cognitive assessment across the menstrual cycle possible? A feasibility study

YesOBJECTIVES: Variation in plasma hormone levels influences the neurobiology of brain regions involved in cognition and emotion processing. Fluctuations in hormone levels across the menstrual cycle could therefore alter cognitive performance and wellbeing; reports have provided conflicting results, however. The aim of this study was to assess whether objective assessment of cognitive performance and self-reported wellbeing during the follicular and luteal phases of the menstrual cycle is feasible and investigate the possible reasons for variation in effects previously reported. METHODS: The Cambridge Neuropsychological Test Automated Battery and Edinburgh Postnatal Depression Scale were used to assess the cognitive performance and wellbeing of 12 women. Data were analysed by self-reported and hormone-estimated phases of the menstrual cycle. RESULTS: Recruitment to the study and assessment of cognition and wellbeing was without issue. Plasma hormone and peptide estimation showed substantial individual variation and suggests inaccuracy in self-reported menstrual phase estimation. CONCLUSION: Objective assessment of cognitive performance and self-assessed wellbeing across the menstrual cycle is feasible. Grouping data by hormonal profile rather by self-reported phase estimation may influence phase-mediated results. Future studies should use plasma hormone and peptide profiles to estimate cycle phase and group data for analyses

Mobility Experiments With Microrobots for Minimally Invasive Intraocular Surgery

Purpose.: To investigate microrobots as an assistive tool for minimally invasive intraocular surgery and to demonstrate mobility and controllability inside the living rabbit eye. / Methods.: A system for wireless magnetic control of untethered microrobots was developed. Mobility and controllability of a microrobot are examined in different media, specifically vitreous, balanced salt solution (BSS), and silicone oil. This is demonstrated through ex vivo and in vivo animal experiments. / Results.: The developed electromagnetic system enables precise control of magnetic microrobots over a workspace that covers the posterior eye segment. The system allows for rotation and translation of the microrobot in different media (vitreous, BSS, silicone oil) inside the eye. / Conclusions.: Intravitreal introduction of untethered mobile microrobots can enable sutureless and precise ophthalmic procedures. Ex vivo and in vivo experiments demonstrate that microrobots can be manipulated inside the eye. Potential applications are targeted drug delivery for maculopathies such as AMD, intravenous deployment of anticoagulation agents for retinal vein occlusion (RVO), and mechanical applications, such as manipulation of epiretinal membrane peeling (ERM). The technology has the potential to reduce the invasiveness of ophthalmic surgery and assist in the treatment of a variety of ophthalmic diseases

Growth and Labelling of Cell Wall Components of the Brown Alga Ectocarpus in Microfluidic Chips

Polydimethylsiloxane (PDMS) chips have proven to be suitable environments for the growth of several filamentous organisms. However, depending on the specimen, the number of investigations concerning their growth and cell differentiation is limited. In this work, we monitored the developmental pattern of the brown alga Ectocarpus inside PDMS lab-on-chips. Two main methods of inoculation of the lab-on-chip were tested, i.e., via the direct injection of spores into the chamber as well as through the insertion of sporophyte filaments. The resulting growth rate, growth trajectory, cell differentiation, and cell branching were monitored and quantified for 20 days inside 25 or 40 μm parallel channels under standard light and temperature conditions. With growth rates of 2.8 μm⋅h–1, normal growth trajectories and cell differentiation, as well as branching occurring inside the microfluidic environment, the main development steps were shown to be similar to those observed in non-constrained in vitro conditions. Additionally, the labelling of Ectocarpus cell wall polysaccharides using calcofluor for cellulose detection and immunolocalisation with monoclonal antibodies for alginates showed the expected patterns when compared to open space growth evaluated with either epifluorescence or confocal microscopy. Overall, this article describes the experimental conditions for observing and studying the basic unaltered processes of brown algal growth using microfluidic technology which provides the basis for future biochemical and biological researches.</jats:p

Bioassay-guided isolation and identification of antimicrobial compounds from thyme essential oil by means of overpressured layer chromatography, bioautography and GC-MS

A simple method is described for efficient isolation of compounds having an antibacterial effect. Two thyme (Thymus vulgaris) essential oils, obtained from the market, were chosen as prospective materials likely to feature several bioactive components when examined by thin layer chromatography coupled with direct bioautography as a screening method. The newly developed infusion overpressured layer chromatographic separation method coupled with direct bioautography assured that only the active components were isolated by means of overrun overpressured layer chromatography with online detection and fractionation. Each of the 5 collected fractions represented one of the five antimicrobial essential oil components designated at the screening. The purity and the activity of the fractions were confirmed with chromatography coupled various detection methods (UV, vanillin-sulphuric acid reagent, direct bioautography). The antibacterial components were identified with GC-MS as thymol, carvacrol, linalool, diethylphthalate, and alpha-terpineol. The oil component diethyl-phthalate is an artificial compound, used as plasticizer or detergent bases in the industry. Our results support that exploiting its flexibility and the possible hyphenations, overpressured layer chromatography is especially attractive for isolation of antimicrobial components from various matrixes

Uncovering the hidden costs of offshoring: The interplay of complexity, organizational design, and experience

This study investigates estimation errors due to hidden costs—the costs of implementation that are neglected in strategic decision-making processes—in the context of services offshoring. Based on data from the Offshoring Research Network, we find that decision makers are more likely to make cost-estimation errors given increasing configuration and task complexity in captive offshoring and offshore outsourcing, respectively. Moreover, we show that experience and a strong orientation toward organizational design in the offshoring strategy reduce the cost-estimation errors that follow from complexity. Our findings contribute to research on the effectiveness of sourcing and global strategies by stressing the importance of organizational design and experience in dealing with increasing complexity

Simulation-based analysis of micro-robots swimming at the center and near the wall of circular mini-channels

Swimming micro robots have great potential in biomedical applications such as targeted drug delivery, medical diagnosis, and destroying blood clots in arteries. Inspired by swimming micro organisms, micro robots can move in biofluids with helical tails attached to their bodies. In order to design and navigate micro robots, hydrodynamic characteristics of the flow field must be understood well. This work presents computational fluid dynamics (CFD) modeling and analysis of the flow due to the motion of micro robots that consist of magnetic heads and helical tails inside fluid-filled channels akin to bodily conduits; special emphasis is on the effects of the radial position of the robot. Time-averaged velocities, forces, torques, and efficiency of the micro robots placed in the channels are analyzed as functions of rotation frequency, helical pitch (wavelength) and helical radius (amplitude) of the tail. Results indicate that robots move faster and more efficiently near the wall than at the center of the channel. Forces acting on micro robots are asymmetrical due to the chirality of the robot’s tail and its motion. Moreover, robots placed near the wall have a different flow pattern around the head when compared to in-center and unbounded swimmers. According to simulation results, time-averaged for-ward velocity of the robot agrees well with the experimental values measured previously for a robot with almost the same dimensions

Resurrecting melancholia

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65798/1/j.1600-0447.2007.00958.x.pd

Fundamentals of Bowel Cancer for Biomedical Engineers

This is the final version. Available on open access from Springer via the DOI in this recordBowel cancer is a multifactorial disease arising from a combination of genetic predisposition and environmental factors. Detection of bowel cancer and its precursor lesions is predominantly performed by either visual inspection of the colonic mucosa during endoscopy or cross-sectional imaging. Most cases are diagnosed when the cancer is already at an advanced stage. These modalities are less reliable for detecting lesions at the earliest stages, when they are typically small or flat. Removal of lesions at the earliest possible stage reduces the risk of cancer death, which is largely due to a reduced risk of subsequent metastasis. In this review, we summarised the origin of bowel cancer and the mechanism of its metastasis. In particular, we reviewed a broad spectrum of literatures covering the biomechanics of bowel cancer and its measurement techniques that are pertinent to the successful development of a bowel cancer diagnostic device. We also reviewed existing bowel cancer diagnostic techniques that are available for clinical use. Finally, we outlined current clinical needs and highlighted the potential roles of medical robotics on early bowel cancer diagnosis.Engineering and Physical Sciences Research Council (EPSRC)China Scholarship Counci