Purpose: Post-transplant frailty is a risk factor for poorer health-related quality of life, rehospitalization, and death.We aimed to evaluate the feasibility, safety, and efficacy of a remote mHealth-supported physical activity pilot intervention to treat frailty in lung transplant recipients following discharge from their index hospitalization.Methods: We screened lung transplant recipients for frailty at the time of discharge at the University of Pennsylvania and UC San Francisco.Frailty was defined as a Short Physical Performance Battery (SPPB) score ≤7 and pre-frail as 8-9 (range 0-12, higher scores reflect less frailty).The primary intervention modality was Aidcube, a customizable app-based platform for home-based pulmonary rehabilitation providing personalized exercise prescriptions, for 8 weeks post-discharge.The primary aims included tolerability, feasibility, and acceptability of use of the mHealth platform.Additional outcome measures were changes in SPPB score and in scores of physical activity and disability measured using the DASI and LT-VLA.Results: No adverse events were reported across the 18 study subjects throughout the 152 subject-week study time.Several themes emerged from weekly subject feedback.Subjects reported that the app was easy to use and that usability improved over time.Subjects also found that app use enhanced motivation to engage in post-transplant rehabilitation.Comments also highlighted the complexities of rehabilitation after lung transplant surgery, including level of functional decline, pain, tremor, and fatigue.At the end of the intervention, SPPB scores improved a median of 5 points (IQR 4, 7; p<0.0001) from a baseline of 4 (IQR 0, 7).Physical activity and patient-reported disability also improved.The DASI improved from 4.5 (IQR 0.0, 10.0) to 19.8 (IQR 15.2, 32.3)) (p=0.001) and LT-VLA score improved from 2 (IQR 1.2, 2.53) to 0.59 (IQR 0.14, 1.18) (p=0.001) at closeout.Conclusion: Utilization of a personalized, app-based rehabilitation platform with participant-specific exercise prescriptions was safe and well received by post-lung transplant recipients.Remote rehabilitation was associated with improvements in frailty, physical activity and disability.Future studies should further evaluate mHealth treatment modalities in larger-scale randomized trials of lung transplant recipients.

Purpose The fabrication and characterization of a hydrogel-based conductometric sensor have been carried out. The purpose of this research is to fabricate a small robust hydrogel-based conductometric sensor for real-time monitoring of pH in the physiological range. Design/methodology/approach A pH-responsive Chitosan/Gelatin composite hydrogel has been used for this purpose. This study reports and analyzes the sensing response obtained from four hydrogel compositions with varying Chitosan/Gelatin ratios. The pH-responsive nature of the hydrogel has been mapped out through volumetric and conductometric tests. An attempt has been made to correlate these characteristics with the physico-chemical nature of the hydrogel through scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction techniques. Findings The four hydrogel compositions differed on the basis of gel composition ratios; the conductometric analysis results prove that the sensor with the hydrogel composition (Chitosan 2 per cent, Gelatin 7 per cent, ratio 1:2) produces the best pH resolution in the pH range of 4 to 9. The sensing mechanisms and the differences obtained between individual sensor outputs have been discussed in detail. On the basis of this extensive in vitro assessment, it has been concluded that while key pendant functional groups contribute to pH-responsive characteristics of the hydrogel, the overall sensitivity of the sensors gel component to surrounding pH is also determined by the crystalline to amorphous ratio of the hydrogel composite, its interpenetrating cross-linked structure and the relative ratio of the hydrophilic to the pH-sensitive components. Practical implications The conductometric sensor results prove that the fabricated sensor with the shortlisted hydrogel composition shows good sensitivity in the physiological pH range (4 to 9) and it has the potential for use in point of care medical devices for diagnostic purposes. Originality/value This is the first reported version of the fabrication and testing and analysis/comparison of a hydrogel-based conductometric sensor based on this composition. The work is original and has not been replicated anywhere.

The pH dependent conductance of the Chitosan/Gelatin and Hydroxy-Ethyl Methacrylate (HEMA)/ Gelatin hydrogel based systems was mapped out using a data acquisition system and several aspects of conductance characteristics namely accuracy, response time and sensitivity were compared and discussed. The material characteristics of these sensors were mapped out through FTIR. Specific accuracy tests were designed and conducted and both hydrogel based sensors have been found to give a reasonably predictable outcomes in the physiological pH range (4-10). Although Chitosan/Gelatin sensing systems have been explored with regards to conductivity, to the best of our knowledge, HEMA/Gelatin composite has not yet been explored in this respect. There are observable differences in the conductometric system analysis results of both hydrogels; it has been found that HEMA based hydrogels have a longer response time, but also offer abetter sensitivity as compared to Chitosan based conductometric hydrogels. This difference in response maybe attributed to the material based characteristics of the conductometric sensing system; the possible underlying mechanisms have also been discussed in this research. Our findings indicate that these conductometric composite hydrogels have the potential to be used in physiological applications; where varying response times are required, a hybrid sensor array comprising ofboth types of hydrogel sensors may be used; that can utilize the advantages of faster response time in case of Chitosan/Gelatin and better sensitivity in case of HEMA/ Gelatin sensors.

Porous polystyrene microspheres were produced by a process of nonsolvent induced phase separation (NIPS) from ternary polymer-solvent-nonsolvent (polystyrene-toluene-ethanol) systems and characterized by scanning electron microscopy (SEM) and small-angle X-ray scattering (SAXS) techniques. This study provides evidence for a link between the structural morphology of the porous polystyrene particles and the polystyrene concentration in the initial solutions. A reciprocal relationship between pore diameter and polymer concentration was observed for the systems with the polymer amount below the critical chain overlap concentration, C*. Above C*, this relationship breaks down. The reciprocal relationship between porosity and polymer concentration can be used to facilitate the fine control of the void size. We demonstrate that the observed reciprocal relationship between pore diameter and polymer concentration correlates well with the relative amount of nonsolvent present in the system at the onset of the phase separation process. The pore size can be reduced and, consequently, the pore surface area can be increased either by reducing the polymer concentration in the initial solution or by decreasing the polymer molecular weight in the sample composition.

Within Tissue Engineering one of the greatest challenges is providing cells in an engineered tissue with nutrients and oxygen via blood or serum. The process, otherwise known as perfusion, brings these vital supplies to within 100-200 microns of all cells by means of the vascular network. If perfusion is insufficient cells begin to die (necrosis) which effectively self-regulates cell growth to within 150-200 micron of a diffusive oxygen source and limits the useful thickness of cellularised tissue that can be engineered in vitro. A spectrum of research approaches ranging from cell-based therapies that attempt to induce spontaneous budding of capillary structures to scaffold based therapies that provide a spatial prevascular structure to guide the formation of the vascular network are currently being investigated. This contribution discusses the research that has been undertaken to indirectly fabricate prevascular scaffolds. Inkjet printing is used to make sacrificial three-dimensional microstructures that are initially employed in the production of the biomimetic 3D microfluidic devices. The process is complimented by the use of low temperature thermal phase change materials e.g. Hexadecane and Octadecane, as inks that enable structurally sound three-dimensional microstructures to be constructed, and then sacrificed without damage to the biocompatible materials (gelatin with a variety of cross linking mechanisms) used for the prevascular scaffold.

This article reports on a number of experiments that have been performed, which show that the resistance of silver lines formed in channels is lower than silver lines that have been formed on unstructured surfaces. Channels were formed either by being cut into polyimide (Kapton) using a laser or by hot embossing a polycarbonate blend (Bayfol). An ink jet printer was used to dispense silver-containing ink over the embossed channels, the laser cut channels and over unstructured Kapton and Bayfol to allow comparison. Two types of silver-containing ink were used, one was a nanoparticle (NP) ink and the other was a metallo-organic decomposition (MOD) ink. For the NP ink, a decrease in resistance was seen for the lines formed in hot embossed channels. For the MOD ink, the resistance decrease was seen for lines formed in both the embossed and the laser cut channels. (C) 2011 Society for Imaging Science and Technology [DOI: 10.2352/J.ImagingSci.Technol.2011.55.4.040302]

In the last decade, many communities in Australia have faced prolonged drought periods. Water authorities have responded with various demand and supply measures ranging from water conservation and water restrictions to seawater desalination. Most of the above measures are associated with some environmental, economic and/or social impacts. These measures can also affect the key objectives of water utilities such as providing a reliable supply of low cost, high quality water while maintaining the environmental health. Some of the above objectives tend to be mutually conflicting, highlighting that decisions associated with key operations and system planning must be based on an assessment of such multiple objectives.For many water authorities, the multi-objective decisions on key operations and system planning need to be made considering uncertainties in future streamflow conditions. For water supply systems that have the capacity to store large volumes of water, this may require the consideration of potential streamflow conditions over many future years. In addition, the decisions may also involve trading-off short-term operations such as greater use of higher-cost water sources with longer-term solutions to supply-demand balance. The latter may include a range of demand management or supply augmentation measures. The complexity of making the above decisions calls for a multi-objective optimisation approach that considers key operation decisions and supply-demand balance decisions over temporal and spatial scales ranging from long-term strategic decisions down to more detailed annual system operation planning. Despite this clear need, optimisation tools are not widely available or used in the water industry. In contrast, simulation modelling tools, such as REALM, have been widely used by many water authorities in Australia to assist with system planning and operations. REALM simulates the water allocation within a system in accordance with user-defined operating rules, but does not optimise the system operations over time.The integration of new supplies and the need to consider multiple objectives in water system planning and operations prompted Melbourne Water to engage water system optimisation specialists Optimatics to develop a decision support system, Optimizer WSS, for water supply system optimisation. Optimizer WSS employs a Multi-Objective Genetic Algorithm (MOGA) optimisation which in turn uses Melbourne Water's existing REALM simulation model to efficiently assess the consequences of millions of combinations of alternative decisions on key operations and the long-term supply-demand balance for a range of potential future hydrological scenarios. The optimisation identifies superior solutions termed 'Pareto-Optimal solutions' considering the range of water supply objectives. The Pareto-Optimal solutions enable Melbourne Water and its stakeholders to select the most suitable solution by optimally balancing one or more water supply objectives against the others, through a Multi-Criteria Decision Analysis (MCDA) considering an array of additional assessment criteria as well. The complex issue of streamflow uncertainty is addressed through a streamflow-scenario based optimisation followed by testing of optimal solutions for their robustness under different streamflow scenarios. The whole process is built on a high level of stakeholder engagement.Initial tests of Optimizer WSS comprising MOGA, MCDA and Solution Presentation components have shown the potential of the tool, as part of a suite of tools, to support decisions on water system planning and operations. The paper presents the Optimizer WSS modelling process, the multi-objective model formulation used for testing, and the initial test results under a hypothetical streamflow and demand scenario.

Large, single-grain Y–Ba–Cu–O (YBCO) was fabricated via the infiltration of Ba–Cu–O liquid into a precursor body composed of solid, porous Y2BaCuO5 (Y-211) and observed to trap a magnetic field of 0.15 T at 77 K. In this process a NdBCO seed crystal was used to promote heterogeneous nucleation, which allows the fabrication of single-grain YBCO containing a uniform and very fine distribution of Y-211 inclusions in the YBa2Cu3O7−δ(Y-123) matrix without the addition of Pt. These superior microstructural features and significant field trapping ability compared with samples processed by conventional top-seeded melt growth suggest this technique could be a practical alternative for processing large, single-grain superconductors for engineering applications.

This paper reports upon the design of electromagnetic vibration-driven energy generators using a variational formulation to derive the equation of motion of such generators, thereby gaining insight into the device physics. Using this approach, the characteristics of the generator are analytically studied, a newly developed optimization theory of the generator is derived, and a guide for the sizing process is described. A fabricated prototype of an electromagnetic vibration harvester is presented. For the fabrication of the prototype, printed circuit board materials and PMMA have been used to lower the cost and to achieve lightweight device. Analytical and experimental results are presented and compared. The fabricated harvester weighs 7 g, delivers 315 μW at optimum excitation parameters at room temperature, and has a mechanical damping ratio of 0.0186. Experimental and analytical results show good agreement with the newly developed optimization theory. An analytical expression of the optimum load resistance is also developed and validated with experimental results, which show the frequency dependence of the optimum load resistance. It is also demonstrated that the optimization process needs two iterations if the mechanical damping ratio is unknown at the start of development and that the coil parameters represent the degree of freedom of the designer.

Printed electronics represent an emerging area of research that promises large markets due to the ability to bypass traditional expensive and inflexible silicon-based electronics to fabricate a variety of devices on flexible substrates using high-throughput printing approaches. This article presents a summary of work to date in the field of printed electronics and the materials chemistry involved. In particular, the focus is upon the use of metal-and metal oxide-containing inks in the preparation of contacts and interconnects. The review discusses the challenges associated with processing these types of inks and ways to successfully obtain the desired features.

We present the building of a custom made inkjet printer platform, and show its versatility for different applications. Inkjet printheads produce droplets of ink with a diameter of <50 mu m, and can thereby accurately produce small structures. The ink can contain many different materials in the form of nanoparticles or in solution. By selection of the ink and choosing the optimal printing conditions, unique two and three dimensional structures could be fabricated. The system was designed in a highly modular way, so that it can be adapted to a large variety of different applications. The core elements of the system are microcontrollers that handle the timing and control the sensors and actuators. Four different applications are described to demonstrate the versatility of the system.

This article presents a review of the current status of the use of inkjet technology with protein-related applications. It includes a brief history of inkjet printing, discusses the advantages of employing the technology with proteins, using a number of selected applications as illustration, and concludes with a view of future research directions.

Introduction We present a parallel low-cost MR receiver array for microfluidic analysis. The platform is based on a standard printed circuit board (PCB) process and a laser cut PMMA. Each PCB holds four glass capillaries. Each capillary has a solenoidal pick-up coil wrapped around it. The coil forms part of a resonant tuning and matching circuit, which is connected to a channel of the MRI spectrometer via co-axial cable. The PMMA layer holds the capillaries in position and simplifies the microfluidic connection to the capillaries. By using a rapid prototyping laser cutter the setup is easily adjusted to different capillary diameters. The resonant circuits are tuned to 400 MHz for use in a Bruker 9.4 T Scanner in which first measurements were made. Modular capillary holder The array holder is a three layer substrate stack. Its lowest layer is an MR-compatible mechanically robust PCB, that also provides all electrical connections. On top is a 2 mm PMMA frame which is attached to the PCB using a sticky semitransparent 150 μm thick 3M foil. The PMMA aligns the capillaries w.r.t. the PCB (and hence to the B0-field of the MR-scanner) and eases the fluidic connection to the capillaries. One area of the PCB is used to connect the coils electrically. The second area contains the other electrical parts of the resonance circuit and the cable connector to the scanner. The PCB has space for four capillary setups.The PCBs are stacked vertically to form an array that is theoretically limited by the number of available measurement channels. The platform is used in receive mode in the 9.4 T scanner, and hence needs to fit into the 72 mm bore of the transmit coil, thereby currently limiting the stack to three layers or 12 channels as shown in Figure 1. The PMMA is micromachined with a rapid prototyping infrared laser. This approach allows an adaption of the system to different types of capillaries and coils. The PMMA layer has an opening at each end of the capillary forming a vial. The capillary is fixed in the holder using thermally setting glue. The glue also seals the vials. A liquid that is inserted into a vial is held there by surface tension forces, and additionally is sucked into the capillary. An initial version of this device using highly precise MEMS techniques, consisting of SU8 on a gold track carrying wafer was reported [1]. The new approach is not only considerably cheaper but also allows rapid reconfiguration due to the laser process. Through heating the thermosetting glue, the capillaries are easily replaced and allows reuse of the PCBs. Tuning and matching circuit Rotating transverse magnetisation from nuclear spins of the fluid creates an induction voltage in an electric conductor in the vicinity. For this purpose a solenoidal coil that is part of a resonant circuit is intimately wound around the capillary to pick up the MR signal of the fluid ́s spins. The resonant circuit that filters the signal consists of the coil and additionally of three capacitors, which are used to tune to a resonance frequency of 400 MHz and to match the circuit to the 50 Ω of the scanner cable. Being solenoids, the coils do not significantly couple to each other. Solenoidal wire coils The setup is designed to take different types of receiver coils. Coils of type 1 are made of a manually wound copper wire. For this approach the inductances of the coils varies from coil to coil. Having tuning and matching capabilities for each coil this can be compensated for. Figure 2 shows the frequency response of the wire coils. The Q-factor is around ~42, the coils should therefore have good receiving properties.

Introduction We present for the first time the results of a self-resonant MR receiver coil, manufactured on a flexible Kapton foil, with the metal lines pattern by inkjet printing. The conductive tracks of the coil were produced using a colloidal silver ink. The supporting capacitors in the inductive loop have also been produced by inkjet printing. An MRI image sequence was taken using a Bruker BioSpec scanner at 9.4 T. The results of the measurement were comparable to a standard receiver coil. Inkjet printing can therefore be considered as a feasible approach in the rapid and low cost production of receiver coils. Preliminary steps and supporting components In a commercial PCB technique, copper is selectively removed from a completely covered substrate. Inkjet printing works the other way round, in that it is an additive technique. The conductive material is deposited only where it is desired. The proof of principle of inkjet printing RF components was done by Redinger et al, who produced components for RF-ID Tags/circuits at 13.5 MHz [1]. In order to achieve the goal, an inkjet printable version of all the electrical components of the receiver circuit had to be found and analysed [2]. A receiver circuit is a resonance circuit. The resonant circuit is based on the resistance R [Ω], the inductance L [H] and capacitance C [F] of the loop. Test series for each component have been inkjet printed and characterised. The components showed a fairly linear scaling behaviour with regard to size (L and C) and to layer thickness (R) [3]. Printing the circuit and the measurement The targeted scanner has 9.4 T field, the coil needed therefore to be optimized for 400 MHz. The coil was 25 mm by 25 mm, and the track width was 1mm Fig. 1. As the coil had a circumference of ~100 mm, two capacitors were inserted into the coil, homogenising the field distribution and reducing wave effects. These two capacitors were implemented, by inkjet printing the tracks of the coil piecewise on both sides of the substrate (Fig. 2) using a Dimatix Material Printer (DMP 2800, FujiFilm Dimatix). The substrate had a thickness of 50 μm. By printing the parts of the track on opposing surfaces of the thin substrates, they formed two capacitors that uses Kapton/Polyimide as the dielectric (εr=3.6), see Fig. 1. The silver ink (SunTronic U5603, SunJet, Bath , UK) needed to be dried and the silver particles to be sintered together, again the Kapton (200HN 50 μm, Krempel Group) proved to be ideal because it can sustain the temperature of 300°C which was used to thoroughly cure the silver track. The values of the capacitors can easily be calculated since they result from pure geometrical properties; they scale with the overlapping area of the tracks (4 mm2 = 2.6 pF) [2]. The Kapton foil with the coil-capacitor arrangement is connected to a small circuit which matches the setup to the 50 Ω wave resistance and allows retuning around 400MHz Fig. 4. The tuning capacitors can be set between 5 – 13 pF and the matching capacitor between 2 – 8 pF. The tuning was done using a network analyser (Agilent 5071C). The Bode diagram of the tuned and matched circuit is shown in Fig. 3. The circuit was connected to a Bruker BioSpec 94/21 Magnet at 9.4T (Bruker BioSpin GmbH Germany). Gradient echo images of a silicone oil phantom were taken. Fig. 5 shows the resultant images, the coil showed behaviour comparable to commercial coils. Conclusions and outlook Inkjet printing was used for the first time to produce and test an MRI receiver coil. The advantage of this fabrication process is that it allows the direct creation of coils. The process produces the structures rapidly and has a geometrical accuracy which is better than 100 μm. It can, therefore, speed up the iterative process of finding optimized coil shapes. Also inkjet printing is not limited to planar substrates, since it can be easily adapted to produce non-planar structures.

A piezoelectric drop-on-demand ink-jet printer has been used to build three-dimensional structures by direct deposition of alumina ink containing submicron ceramic particles suspended in an alkane wax. Inks containing up to 40 % v/v alumina were used to produce cubes in which support structures were made from paraffin wax. The fabrication process consists of the sequential deposition of layers of the ceramic suspension by the ink-jet printer. This organic vehicle was removed by capillary action in a powder bed followed by pyrolysis before sintering the alumina product. Ink-jet deposition results in the formation of a solid structure after droplet impact and solidification. The distribution of alumina in the solid deposit has been studied and correlated with measurements of shrinkage during the dewaxing and sintering stages. A slight anisotropy is observed in that shrinkage in the z axis is greater than for the in-plane directions.