Computer-controlled Apparatus Research Articles

Evaluation of Neuroprotective Effects of Local Hypothermia in a Porcine Spinal Cord Injury Model

Abstract The goal of this study was to assess the therapeutic potential of a 5-hour local spinal cord (SC) hypothermia by 4 °C saline on preservation of SC tissue at the injury epicentre and 3 cranial and caudal 10 mm long SC segments in a porcine experimental model of spinal cord injury (SCI). The SCI was inflicted through L3 laminectomy by a metallic rod moved by a velocity of 30 mm.sec−1, and operated by a computer-controlled apparatus. A group of 15 female minipigs 5‒8-month-old weighing 28‒35 kg was randomly divided into 5 subgroups (each composed of 3 animals): 1) sham controls; 2) SCI by force 8N; 3) SCI by force 8N, 5-hour hypothermia; 4) SCI by force 15N; 5) SCI by force 15N, 5-hour hypothermia. After a 9-week survival period, the minipigs were in deep general anaesthesia transcardially perfused by 5000 ml of saline and fixed by 5000 ml 4 % neutral paraformaldehyde. White and grey SC matter damage was evaluated in specimens cut from the epicentre of injury as well as 3 cranial and 3 caudal 10 mm long SC blocks dyed according to Luxol fast blue (LFB) with cresyl violet (CV) protocol for light microscopic observations. The percentage of preserved SC white and grey matter was assessed in microphotographs and compared with data from sham controls (considered 100 %). The data were statistically evaluated by ANOVA test, the difference P ˂ 0.05 was considered significant. Results of the study suggest that 5-hour local cooling of the epicentre of SCI is well tolerated and facilitates the preservation of SC tissue integrity. Additional experimental and preclinical studies are necessary before introducing the method in practice.

The respiratory resistance sensitivity task: An automated method for quantifying respiratory interoception and metacognition

The ability to sense, monitor, and control respiration – e.g., respiratory interoception (henceforth, respiroception) is a core homeostatic ability. Beyond the regulation of gas exchange, enhanced awareness of respiratory sensations is directly related to psychiatric symptoms such as panic and anxiety. Indeed, chronic breathlessness (dyspnea) is associated with a fourfold increase in the risk of developing depression and anxiety, and the regulation of the breath is a key aspect of many mindfulness-based approaches to the treatment of mental illness. Physiologically speaking, the ability to accurately monitor respiratory sensations is important for optimizing cardiorespiratory function during athletic exertion, and can be a key indicator of illness. Given the important role of respiroception in mental and physical health, it is unsurprising that there is increased interest in the quantification of respiratory psychophysiology across different perceptual and metacognitive levels of the psychological hierarchy. Compared to other more popular modalities of interoception, such as in the cardiac domain, there are relatively few methods available for measuring aspects of respiroception. Existing inspiratory loading tasks are difficult to administer and frequently require expensive medical equipment, or offer poor granularity in their quantification of respiratory-related perceptual ability. To facilitate the study of respiroception, we here present a new, fully automated and computer-controlled apparatus and psychophysiological method, which can flexibly and easily measure respiratory-related interoceptive sensitivity, bias and metacognition, in as little as 30 min of testing, using easy to make 3D printable parts.

Experimental Measurement of Steady and Transient Liquid Coiling with High-Speed Video and Digital Image Processing

Liquid coiling occurs as a viscous fluid flows into a stagnant reservoir causing a localized accumulation of settling material, which coils into a stack as it accumulates. These coiling flows are broadly characterized into three primary coiling regimes of viscous, gravitational, or inertial coiling, based on the velocity of the falling fluid, the height of the fall, the radius of the fluid rope, the stack height, and the fluid properties including viscosity. A computer-controlled flow delivery apparatus was developed here to produce precisely controlled flow conditions to study steady and transitional coiling regimes with independently varied parameters. Data were recorded using high-speed digital video cameras and a purpose-built digital image processing routine to extract rope and stack dimensions as well as time-resolved coiling frequency. The precision of the setup and data analysis methods allowed a detailed study of the transition between gravitational and inertial flow regimes. The results show a smooth transition between the regimes, with no evidence of the inertial-gravitational regime. Unsteady coiling was able to be momentarily produced by applying a perturbation to the system, but the unstable regime quickly decayed to either the base inertial or gravitational regime.

Mechanically Stimulated Osteoblast Cells Growth

The bones need to be built and then permanently restored to keep them functioning properly. Considering the multiple bone functions, their vitality is essential both to maintain the body and move it and to maintain its health and vigor. When most bones begin to age and have no vital function, the man also begins to age, lose water, minerals, electrolytes, energy, food. We can firmly affirm that healthy bones maintain an excellent health of the human body. All of the bones in the young have the role of deposit, water, electrolyte, minerals, energy, substances necessary for the growth and repair of human cells and organs, a part (red marrow) that permanently produces the vital blood for the organism with the three vital cell types: red (body oxygenation), white (which defends the body) and platelets (it clogs the blood when a wound appears). More recently, it is also known that the red marrow is responsible for the stem cells production, cells which are so necessary to the body because they can adapt to anywhere in the body in any organ, rapidly generating the various types of cells needed. In the bones of the young and most of the adult, all these functionalities appear, so that when an accident requires a human operation it is good to resort to mild and specialized interventions so that the bone in question can quickly recover all features. Otherwise, the body of that person has a major future health and integrity problem, as is the case with older people or those with serious bone diseases. The research develops and tests new hybrid biomimetic materials that work as mechanically stimulating “scaffolds” to promote early regeneration in implanted bone healing phases. A biomimetic nanostructured osteoconductive material coated apparatus is presented. Bioinspired approaches to materials and templated growth of hybrid networks using self-assembled hybrid organic-inorganic interfaces are finalized to extend the use of hybrids in the medical field. Combined in vivo, in vitro and computer-aided simulations have been carried out. Such multidisciplinary approach allowed us to explore many novel ideas in modeling, design and fabrication of new nanostructured biomaterials and scaffolds with enhanced functionality and improved interaction with OB cells. In vivo tests of Titanium screw implanted in rabbit, tibiae have shown that mechanical stimulation was induced by the presence of bioactive hybrid perimplantar scaffold resulting in a differentiation and development of mesenchymal tissues. In order to investigate the relationship between bone growth and applied mechanical loading (strain), a piezoelectrically driven cantilever and a computer-controlled apparatus for "in vitro" tests has been developed and presented.

Notch Signaling Participates in TGF-β-Induced SOST Expression Under Intermittent Compressive Stress.

Notch signaling is regulated by mechanical stimuli in various cell types. It has previously been reported that intermittent compressive stimuli enhanced sclerostin (SOST) expression in human periodontal ligament cells (hPDLs) by regulating transforming growth factor-β (TGF-β) expression. The aim of the present study was to determine the involvement of Notch signaling in the TGF-β-induced SOST expression in hPDLs. Cells were treated with intermittent compressive stress in a computer-controlled apparatus for 24 h. The mRNA and protein expression of the cells were determined by real-time polymerase chain reaction and Western blot analysis, respectively. In some experiments, the target signaling pathway was impeded by the addition of a TGF-β receptor kinase inhibitor (SB431542) or a γ-secretase inhibitor (DAPT). The results demonstrated that hPDLs under intermittent compressive stress exhibited significantly higher NOTCH2, NOTCH3, HES1, and HEY1 mRNA expression compared with control, indicating that mechanical stress induced Notch signaling. DAPT pretreatment markedly reduced the intermittent stress-induced SOST expression. The expression of NOTCH2, NOTCH3, HES1, and HEY1 mRNA under compressive stress was significantly reduced after pretreatment with SB431542, coinciding with a reduction in SOST expression. Recombinant human TGF-β1 enhanced SOST, Notch receptor, and target gene expression in hPDLs. Further, DAPT treatment attenuated rhTGF-β1-induced SOST expression. In summary, intermittent compressive stress regulates Notch receptor and target gene expression via the TGF-β signaling pathway. In addition, Notch signaling participates in TGF-β-induced SOST expression in hPDLs. J. Cell. Physiol. 232: 2221-2230, 2017. © 2016 Wiley Periodicals, Inc.

Non-Destructive High-Resolution Conductivity Mapping of Thin-Film Battery Electrodes

Accurately determining electronic conductivity of thin-film battery electrodes is not trivial, especially with the metallic current conductor still attached. A fast and reliable method would be of use for quality control and optimization purposes in battery manufacture, and would provide insight into the effects of changes in the fabrication process on the electrode structure. We report a four-line probe that has been used to make high-resolution maps of local electrode conductivity on the micron scale. A computer-controlled apparatus allows precise control of pressure on the sample and positioning of the probe. A significant part of the work was developing a novel hybrid numerical-analytical model to invert the experiment, allowing a separate determination of film conductivity and contact resistance at the current collector in real time on a desktop computer. We will discuss the amount of local conductivity variation within representative electrode films. This work was supported by the U.S. Department of Energy through the BMR program. Figure 1

The Effect of Formulation on the Bioactivity of Artemisia Preparations for Metabolic Syndrome

Botanicals have been used for thousands of years as therapeutic agents for many diseases and human conditions. “Metabolic syndrome” is currently defined as a condition whose major features consist of obesity, insulin resistance, development of Type 2 diabetes and accelerated cardiovascular disease and continues to grow at epidemic proportions. Our BRC (Botanical Research Center) focuses on botanicals that can be used for the prevention/treatment of metabolic syndrome. One of the primary research objectives of the BRC as a whole focuses on how the constituents of botanicals affect insulin signaling pathways and improve insulin resistance, the underlying metabolic dysregulation associated with metabolic syndrome. While select species of Artemisia are under current evaluation by the BRC, the extract of Artemisia dracunculus L. (PMI-5011) is the most characterized both in terms of its biological activity and its composition of 6 compounds identified as having antidiabetic activity. The bioavailability of active compounds from Artemisia were measured and related to the formulation of the vehicle in C57Bl6J mice. Comparable bioaccessibility (i.e. potential to be bioavailable) of the active compounds was measured using the TNO intestinal model (TIM), a dynamic multi-compartmental, computer-controlled apparatus that closely simulates all in vivo conditions of the upper GI tract of humans. A comparison of test preparations showed significant improvements in the bioaccessibility, bioavailability and bioactivity for specific formulations relative to the extract alone. These effects will have a profound influence on the effective human dose of Artemisia and must be considered when planning clinical studies.

ELF exposure system for live cell imaging

A programmable system has been developed for the study of both transient and persistent effects of extremely low frequency (ELF) magnetic field exposure of cell cultures. This high-precision exposure system enables experimental blinding and fully characterized exposure while simultaneously allowing live cell imaging. It is based on a live imaging cell around which two asymmetrical coils are wound in good thermal contact to a temperature-controlled water jacket, and is mounted on a microscope stage insert. The applied B-field uniformity of the active volume is better than 1.2% with an overall exposure uncertainty of less than 4.3% with very low transient field levels. The computer-controlled apparatus allows signal waveforms that are sinusoidal or composed of several harmonics, blind protocols, and monitoring of exposure and environmental conditions. B-fields up to 4 mT root mean square amplitude are possible with minimal temperature variation and no recognizable temperature differences between exposure and sham states. Sources of artifacts have been identified and quantified. There are no visible vibrations observable even at the highest magnifications and exposure levels.

Dependence of contact electrification on the magnitude of strain in polymeric materials

We present a new experimental approach to systematically study the effect of material strain on contact electrification. Thin sheets of latex rubber are variably strained by stretching over a hollow cylinder, analogous to a drum. The strained sheets are repeatedly contacted with another surface by a computer-controlled apparatus. The surface potential on the latex rubber is measured in real time by a non-contact electrostatic voltmeter. For unstrained latex rubber, we find that contact with polytetrafluoroethylene (PTFE) leads to a negative surface potential that progressively increases in magnitude to more negative values with increasing number of contacts. When the latex rubber is strained, contact with PTFE causes the surface potential of the latex rubber to shift to less negative values. At strains of more than ∼50%, the polarity of the surface potential is reversed, such that contact with PTFE causes the latex rubber to charge positively. These results indicate that contact electrification intimately depends on the degree of material strain, and may explain how spatial inhomogeneities of charge exist on contacted surfaces and why there is a lack of reproducibility in contact charging experiments.

A Computer-Controlled Apparatus for the Characterization of Mechanical and Viscoelastic Properties of Tissue-Engineered Vascular Constructs

Tissue-engineered blood vessels can be partly characterized by analyzing their mechanical properties using burst pressure testing, compliance measurement, creep and cyclic testing. Studying these parameters provides information on the capability of a fabrication method to produce tissue-engineered blood vessels (TEBV) and allow for the optimization of their resistance and viscoelastic properties. This study presents the design and fabrication of an apparatus allowing accurate and reliable measurements of the mechanical properties of tissue-engineered vascular constructs. A computer-controlled system was designed to monitor pressure and diameter variations of vascular constructs submitted to hydrostatic loading. The system was programmed to control the motorized portion of the setup and allow simultaneous data acquisition, analysis and real-time display. Data acquisition cards allow for synchronous monitoring of pressure and diameter of the constructs through a pressure transducer and a CCD camera. Image analysis and pressure data computation resulted in compliance, creep and dynamic characterization of the tested tissues. This experimental setup succeeded in measuring the burst pressure, compliance, creep and cyclic behavior of tissue-engineered vascular media (TEVM), adventitia (TEVA) and a combination of a media and an adventitia (TEVMA) reconstructed by the self-assembly method. Our apparatus has proven to be a precise and reliable tool for the characterization of the mechanical properties of vascular constructs.

A computer-controlled apparatus for micrometric drop deposition at liquid surfaces

A low-cost, automated apparatus has been used to perform micrometric deposition of small pendant drops onto a quiet liquid surface. The approach of the drop to the surface is obtained by means of discrete, micron-scale translations in order to achieve deposition at adiabatically zero velocity. This process is not only widely used in scientific investigations in fluid mechanics and thermal sciences but also in engineering and biomedical applications. The apparatus has been designed to produce accurate deposition onto the surface and minimize the vibrations induced in the drop by the movement of the capillary tip. Calibration tests of the apparatus have shown that a descent of the drop by discrete translational steps of approximately 5.6 microm and duration of 150-200 ms is sufficient to minimize its penetration depth into the liquid when it touches the surface layer and reduce to a level of noise the vibrations transmitted to it by the translation of the dispenser. Different settings of the experimental setup can be easily implemented for use in a variety of other applications, including deposition onto solid surfaces, surface tension measurements of pendant drops, and wire bonding in microelectronics.

A calorimetric system based on the LKB 10700-1 flow microcalorimeter

An electrically calibrated and computer-controlled apparatus based on the LKB 10700-1 flow microcalorimeter was set up and tested by determining the enthalpies of dilution of aqueous solutions of sucrose and HCl at 298.15 K. The obtained results are in good agreement with the corresponding reference values recommended in the literature. The quality of the calorimetric signal in terms of noise, linearity and baseline drift, and the instrument time constant were analyzed. Also investigated were the influences of the flow rate and of the viscosity of the calorimetric liquid on the position of the baseline. The new calibration system enables powers ∼25 times smaller than those possible with the original one to be released inside the calorimetric cells. Electrical calibrations carried out with water as the sole calorimetric liquid indicated that the precision of the calibration constant, ε, quickly improved from ∼9% to ∼0.4% with the increase of the input power, P, from ∼2 µW to ∼50 µW, and stabilized at ∼0.1% for P ⩾ 100 µW. The calibration constant was also found to linearly increase with the flow rate of the calorimetric liquid and to vary by less than 1% over a period of eight months under similar experimental conditions. Finally a new experimental procedure for heat of dilution measurements, which combines calibration and experiment in a single run, was evaluated. This method allows a significant economy in experiment time with apparently no accuracy loss relative to the conventional procedure recommended in the literature.

Computer-controlled air-conditioning experimental apparatus

A portable experimental setup for demonstrating air-conditioning processes was designed, developed and constructed by a multidisciplinary capstone senior design team. This experimental apparatus is currently being used to demonstrate to undergraduate students air-conditioning processes such as cooling, heating, and humidification. The level of cooling, heating, or humidification is being monitored and controlled using a PC-based control system which consists of LabVIEW and data acquisition unit. This article provides details about the integration of the electrical/electronic component and the control system. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 458–468, 2010; View this article online at wileyonlinelibrary.com; DOI 10.1002/cae.20185

The virtual haptic display: A device for exploring 2-D virtual shapes in the tactile modality

In order to understand better the processes involved in the perception of shape through touch, someelement of control is required over the nature of the shape presented to the hand and the presentation timing. To that end, we have developed a cost-effective, computer-controlled apparatus for presenting haptic stimuli using active touch, known as a virtual haptic display (VHD). The operational principle behind this device is that it translates black and white visual images into topographic, 2-D taxel (tactile pixel) arrays, along the same principle using in Braille letters. These taxels are either elevated or depressed at any one time representing white and black pixel colors of the visual image, respectively. To feel the taxels, the participant places their fingers onto a carriage which can be moved over the surface of the device to reveal a virtual shape. We conducted two experiments and the results show that untrained participants are able to recognize different, simple and complex, shapes using this apparatus. The VHD apparatus is therefore ideal at presenting 2-Dshapes through touch alone. Moreover,this device and its supporting software can also be used for presenting computer-controlled stimuli in cross-modal experiments.

Automated apparatus for dynamic mechanical analysis using the piezoelectric ultrasonic composite oscillator technique

Computer-controlled apparatus for the measurements of dynamic Young's modulus and internal friction as functions of temperature, using the piezoelectric ultrasonic composite oscillator technique (PUCOT), has been designed and demonstrated. The versatility of the apparatus and its resonance tracking techniques have been proven by detecting subtle structural phase transformations within the Ca1−xSrxTiO3 perovskite system as well as dramatic changes accompanying the martensitic transformation in a Au–Cd shape-memory alloy. The simplicity of the PUCOT technique allows a system such as this to be constructed easily and with low cost.

Histone H2A.z Is Essential for Cardiac Myocyte Hypertrophy but Opposed by Silent Information Regulator 2α

In this study we have shown that the histone variant H2A.z is up-regulated during cardiac hypertrophy. Upon its knock-down with RNA interference, hypertrophy and the underlying increase in growth-related genes, protein synthesis, and cell size were down-regulated. During attempts to understand the mode of regulation of H2A.z, we found that overexpression of silent information regulator 2alpha (Sir2alpha) specifically induced down-regulation of H2A.z via NAD-dependent activity. This effect was reversed by the proteasome inhibitor epoxomicin, suggesting a Sir2alpha-mediated ubiquitin/proteasome-dependent mechanism for degradation of H2A.z. An increase in Sir2alpha also resulted in a dose-dependent reduction of the response to hypertrophic stimuli, whereas its inhibition resulted in enhanced hypertrophy and apoptosis. We have shown that Sir2alpha directly deacetylates H2A.z. Mutagenesis proved that lysines 4, 7, 11, and 13 do not play a role in the stability of H2A.z, whereas Lys-15 was indispensable. Meanwhile, Lys-115 and conserved, ubiquitinatable Lys-121 are critical for Sir2alpha-mediated degradation. Fusion of the C terminus of H2A.z (amino acids 115-127) to H2A.x or green fluorescence protein conferred Sir2alpha-inducible degradation to the former protein only. Because H2A.x and H2A.z have conserved N-tails, this implied that both the C and N termini are critical for mediating the effect of Sir2alpha. In short, the results suggest that H2A.z is required for cardiac hypertrophy, where its stability and the extent of cell growth and apoptosis are moderated by Sir2alpha. We also propose that Sir2alpha is involved in deacetylation of H2A.z, which results in ubiquitination of Lys-115 and Lys-121 and its degradation via a ubiquitin/proteasome-dependent pathway.

Dynamics of Oropharyngeal Aerosol Transport and Deposition With the Realistic Flow Pattern

Aerosol flow and deposition in the model of human oropharynx was studied theoretically and experimentally for two realistic inspiratory patterns. The three-dimensional (3D) airflow structure in the sample geometry was solved with the computational fluid dynamics (CFD) code (Fluent), used to calculate dynamic distribution of particle deposition (0.3–10 μm). Experiments were done for the same flow conditions using the silicone-rubber cast with the matching geometry. Nonsteady breathing flows were reproduced with the computer-controlled artificial lung apparatus. Results of computations show that particles smaller than 3 μm easily pass the oropharynx during inspiration, while particles with a size close to 10 μm are substantially deposited, preferentially in the region of the naso-pharyngeal bend. For particles in the submicrometer size range, the spatial and temporal deposition pattern is more complicated, and strongly depends on breathing dynamics. The experiments confirmed that the mass median diameter (MMD) of the aerosol that penetrates the oropharynx and flows to the tracheobronchial tree is reduced. Measured total mass efficiency of deposition of the tested aerosol was in the range of 35–60%, depending on the breathing pattern. These findings are consistent with the CFD results. The methods and the preliminary results enable a more realistic analysis of dynamic effects during the flow of inhaled particles through the complex geometry of the oropharynx. Such analysis is needed for estimation of toxic potential of aerosols, related to their local deposition in different parts of the respiratory tract.

Hydrogen absorption in Ti–Zr–Ni quasicrystals and 1/1 approximants

Ti/Zr-based quasicrystals and their approximants draw attention as new candidate materials for hydrogen storage applications based on recent discoveries that they absorb a large amount of hydrogen, reversibly, at low temperatures and pressures. In fact, Ti 45Zr 38Ni 17 quasicrystals take hydrogen to a maximum value of hydrogen to host metal atom ratio (H/M) of nearly 2. To evaluate their technical usefulness and to probe the local structure of the quasicrystals, pressure–composition isotherms ( p – c – T) were measured above 250 ° C using a computer-controlled apparatus. In the Ti–Zr–Ni quasicrystal, the p – c – T curves do not exhibit a clear pressure plateau. Instead, the equilibrium vapor pressure remains low ( < 5 Torr) below H / M ≈ 1 and increases sharply for increasing H/M. In the Ti–Zr–Ni 1/1 approximant phase, which is a large unit cell bcc structure ( a = 13.13 Å), the p – c – T measurements show similar curves with a hint of pressure plateau consistent with a structural similarity between the phases. The quasicrystals desorb most of the absorbed hydrogen above 600 ° C for 2 h in dynamical vacuum without phase transformation, and they do not become powder, even after a few absorption–desorption cycles. Interestingly, a small amount of Pd inhibits the growth of the (Ti,Zr)H x hydride phase during hydrogenation.

Preparation of Self-Organized Mesoscale Polymer Patterns on a Solid Substrate: Continuous Pattern Formation from a Receding Meniscus

Regular polymer patterns are formed from casting a dilute polymer solution on a solid substrate. Dissipative structures, e.g., convection patterns, fingering instabilities, and so on, are formed in the evaporation process of casting polymer films. Controlled production and manufacturing of patterned polymer films can be achieved when the evaporating solution edge, especially the meniscus region on the casting substrate, is formed under controlled casting conditions. In this report, we describe a computer-controlled apparatus which has two precisely manipulated sliding glass plates. A narrow, thin liquid film of polymer solution with a receding meniscus is continuously supplied from a small gap between two glass plates (one sliding and the other stationary), and a patterned polymer film is subsequently formed on the stationary substrate from the evaporating solution edge. Several types of polymer patterns from various polymers are reproducibly prepared by changing preparation conditions such as sliding speed and polymer concentration.

The Ai project: historical and ecological contexts.

This paper aims to review a long-term research project exploring the chimpanzee mind within historical and ecological contexts. The Ai project began in 1978 and was directly inspired by preceding ape-language studies conducted in Western countries. However, in contrast with the latter, it has focused on the perceptual and cognitive capabilities of chimpanzees rather than communicative skills between humans and chimpanzees. In the original setting, a single chimpanzee faced a computer-controlled apparatus and performed various kinds of matching-to-sample discrimination tasks. Questions regarding the chimpanzee mind can be traced back to Wolfgang Koehler's work in the early part of the 20th century. Yet, Japan has its unique natural and cultural background: it is home to an indigenous primate species, the Japanese snow monkey. This fact has contributed to the emergence of two previous projects in the wild led by the late Kinji Imanishi and his students. First, the Koshima monkey project began in 1948 and became famous for its discovery of the cultural propagation of sweet-potato washing behavior. Second, pioneering work in Africa, starting in 1958, aimed to study great apes in their natural habitat. Thanks to the influence of these intellectual ancestors, the present author also undertook the field study of chimpanzees in the wild, focusing on tool manufacture and use. This work has demonstrated the importance of social and ecological perspectives even for the study of the mind. Combining experimental approaches with a field setting, the Ai project continues to explore cognition and behavior in chimpanzees, while its focus has shifted from the study of a single subject toward that of the community as a whole.