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The BioMedical Admissions Test (BMAT) has been used to select students for healthcare courses for 15 years. Recently, the candidature has included an increasing number of test takers who did not complete their schooling in the UK. In line with responsibilities to promote widening participation, a revision of the Section 2 Scientific Knowledge and Applications specification was conducted, to support the preparation of candidates from under-represented groups and international candidates. The process was guided by validity frameworks established in language testing research, with a particular focus on consequential validity and washback. Candidate surveys are reported to illustrate the focus on test preparation. Issues identified in the review demonstrate the impact of international test-takers' linguistic backgrounds and differences in teaching approaches, and possible interactions between these are discussed. It is recommended that admissions test developers make use of holistic frameworks of validity from other contexts to systematically interrogate a wide range of validity evidence relating to their tests.

Significant advances are being made in the incorporation of enzymes into functional materials, which leverage their inherent substrate specificity, efficient catalytic activity, and sustainable origin. These engineered "dead" materials, however, lack the incredible systems‐level control of enzyme activity that living organisms have evolved over millennia. This gap is now being bridged by the rapidly emerging field of engineered living materials (ELMs), which couples the tools of advanced synthetic biology with modern materials science. In this review, the impressive array of methodologies used to fabricate the extensive library of functional enzyme‐based dead materials is discussed, and the design strategies that facilitate their creation unpacked. The spectacular suite of natural and synthetic genetic and post‐translational control systems for enzymes in living organisms is then described. Finally, key recent examples of ELMs that utilize enzyme activity are reviewed, highlighting the central role of the living component in providing responsivity and adaptability to this new class of materials. [ABSTRACT FROM AUTHOR]

Respiratory syncytial virus (RSV) causes severe infections in infants, immunocompromised or elderly individuals resulting in annual epidemics of respiratory disease. Currently, limited clinical surveillance and the lack of predictable seasonal dynamics limit the public health response. Wastewater-based epidemiology (WBE) has recently been used globally as a key metric in determining prevalence of severe acute respiratory syndrome coronavirus 2 in the community, but its application to other respiratory viruses is limited. In this study, we present an integrated genomic WBE approach, applying reverse-transcription quantitative polymerase chain reaction and partial G-gene sequencing to track RSV levels and variants in the community. We report increasing detection of RSV in wastewater concomitant with increasing numbers of positive clinical cases. Analysis of wastewater-derived RSV sequences permitted identification of distinct circulating lineages within and between seasons. Altogether, our genomic WBE platform has the potential to complement ongoing global surveillance and aid the management of RSV by informing the timely deployment of pharmaceutical and nonpharmaceutical interventions. [ABSTRACT FROM AUTHOR]

The synthesis of a porous shape‐changing interpenetrating network (IPN) bioink for the fabrication of large‐scale (cm) reversibly thermosensitive structures is described. The poly(N‐isopropylacrylamide) (PNIPAm) IPN is generated in situ within an ionically crosslinked alginate hydrogel at room temperature and under aerobic conditions using a horseradish peroxidase (HRP)/glucose oxidase (GOx) bienzymatic initiation system. Mechanical testing assessment of the IPN hydrogels confirm mechanical reinforcement via covalent single network interdigitation. Furthermore, the thermosensitive bioink can be used to print biohybrid reactors containing genetically engineered phosphotriesterase‐expressing E. coli capable of hydrolyzing toxic organophosphorus compounds. Herein, increasing the bioink pore size using the contractile‐thermosensitive response of the IPN improves the temperature‐dependent theoretical mass‐transfer‐limited enzyme catalyzed reaction rate, providing a plausible route to externally regulated enzymatic catalysis within bioprinted structures. [ABSTRACT FROM AUTHOR]

Nanomaterial composition, morphology, and mechanical performance are critical parameters for tissue engineering. Within this rapidly expanding space, tubular nanomaterials (TNs), including carbon nanotubes (CNTs), titanium oxide nanotubes (TNTs), halloysite nanotubes (HNTs), silica nanotubes (SiNTs), and hydroxyapatite nanotubes (HANTs) have shown significant potential across a broad range of applications due to their high surface area, versatile surface chemistry, well-defined mechanical properties, excellent biocompatibility, and monodispersity. These include drug delivery vectors, imaging contrast agents, and scaffolds for bone tissue engineering. This review is centered on the recent developments in TN-based biomaterials for structural tissue engineering, with a strong focus on bone tissue regeneration. It includes a detailed literature review on TN-based orthopedic coatings for metallic implants and composite scaffolds to enhance in vivo bone regeneration. [ABSTRACT FROM AUTHOR]

One of the objectives of Curriculum 2000 is to increase the breadth of the curriculum followed by 16-19 year olds. In this paper A level and AS uptake for the years 2001 and 2002 are considered. There was considerable diversity in the uptake of A levels, with nearly 21,000 different combinations of A levels being present in 2002 A level results. Although it is true that biology, chemistry and mathematics is the most common combination of A levels, only 2.2 per cent of candidates took this precise combination. There has been a decline in the percentage of candidates taking three science A levels. In 2002, when only A levels are considered, 35 per cent of candidates could be described as specialists, falling to 21 per cent when AS results are included. AS qualifications appear to have been successful in broadening the curriculum.

This article demonstrates the feasibility of making a partially buried micro gas chromatography ([micro]-GC) column with a rounded channel wall profile, which enables coaling the stationary phase more uniformly and shows better separation characteristics than a square deep reactive ion etched (DRIE) wall profile. A buried structure fabrication method was adapted to fabricate 34 cm long, 165 [micro]m wide, and 65 [micro]m deep partially buried microcolumns, which had a unique rounded microcolumn wall profile similar to that of a flattened circular tube. The separation characteristics were compared to that of a 34 cm long, 100 [micro]m x 100 [micro]m square DRIE microcolumn, which had a similar hydraulic diameter. Minimum height equivalent to a theoretical plate (HETP) and reduced HETP of 0.39 mm and 6.02, respectively, with a retention factor of 6.3 were obtained on the coated partially buried microcolumn compared to 0.66 mm and 6.73, respectively, on the coated square DRIE microcolumn with a similar retention factor. The partially buried microcolumn was found to perform closer to the theoretical approximation and this could be attributed to the uniform phase deposition in the partially buried microcolumn compared to the square DRIE microcolumn. A 10 component mix was separated on the partially buried microcolumn in 3.8 s with the maximum peak width at half-height equal to 0.2 s, while a similar mix separated at higher pressure and temperature conditions on the square DRIE microcolumn in 4.6 s. The rounded comers allowed depositing thinner stationary phase, which was reflected in the faster elution of n-C12 on the partially buried microcolumn compared to the square DRIE microcolumn. The better performance of the partially buried microcolumn may be attributed to either the rounded channel wall profile, the clean channel structures produced by the fabrication process, or the double-etched wall profile, which lowers the Taylor-Ads dispersion.

Microscale total analysis systems ([micro]TAS) allow high-throughput analyses by integrating multiple processes, parallelization, and automation. Here we combine unit operations of [micro]TAS to create a device that can perform multidimensional separations using a three-dimensional hybrid microfluidic/nanofluidic device composed of alternating layers of patterned poly(methyl methacrylate) and nanocapillary array membranes constructed from nuclear track-etched polycarbonate. Two consecutive electrophoretic separations are performed, the first being an achiral separation followed by a chiral separation of a selected analyte band. Separation conditions are optimized for a racemic mixture of fluorescein-isothiocynate-labeled amino acids, serine and aspartic acid, chosen because there are endogenous D-forms of these amino acids in animals. The chiral separation is implemented using micellar electrokinetic chromatography using [beta]-cyclodextrin as the chiral selector and sodium taurocholate as the micelle-forming agent. Analyte separation is monitored by dual-beam laser-induced fluorescence detection. After separation in the first electrophoretic channel, the preselected analyte is sampled by the second-stage separation using an automated collection sequence with a zero-crossing algorithm. The controlled fluidic environment inherent to the three-dimensional architecture enables a series of separations in varying fluidic environments and allows sample stacking via different background electrolyte pH conditions. The ability to interface sequential separations, selected analyte capture, and other fluidic manipulations in the third dimension significantly improves the functionality of multilayer microfluidic devices.

We report microfabrication of a millimeter-scale fuel cell with onboard fuel and a passive control mechanism. This unique power source has a total volume of 9 [micro]L (3 x 3 x 1 [mm.sup.3]), which makes it the smallest fully integrated fuel cell reported in the literature. The first generation of this device delivered an energy density of 254 W x h/L. The device uses a reaction between a metal hydride, LiA1[H.sub.4], and water vapor to generate hydrogen in a reactor. The generated hydrogen exits the reactor through a nanoporous silicon wall to reach a hybrid silicon/Nation membrane electrode assembly. A passive micro-fluidic control system regulates hydrogen generation through controlled delivery of water vapor to the metal hydride based on the reactor pressure. The development of this unique power source greatly benefits the portable electronics industry and enables future technologies that require significantly high energy density power sources such as cognitive arthropods ('thinking' insect-sized robots). This paper provides details of the device micro-fabrication processes, component integration, and performance analysis. [2008-0168] Index Terms--Fuel cell, hydrogen generation, metal hydride, microvalve, power source, power source for portable electronics.

This article demonstrates how to prepare microfabricated columns (microcolumns) for organophosphonate and organosulfur compound separation that rival the performance of commercial capillary columns. Approximately 16 500 theoretical plates were generated with a 3 m long OV-5-coated microcolumn with a 0.25 [micro]m phase thickness using helium as the carrier gas at 20 cm/s. Key to the advance was the development of deactivation procedures appropriate for silicon microcolumns with Pyrex tops. Active sites in a silicon-Pyrex microcolumn cause peak tailing and unwanted adsorption. Experimentally, we found that organosilicon hydride deactivation lowers adsorption activity in microcolumns more than silazane and silane treatments. But without further treatment, the phosphonate peaks continue to tail after the coating process. We found that heat treatment with pinacolyl methylphosphonic acid (PMP) eliminated the phosphonate peak tailing. In contrast, conventional resilylation employing N,O-bis(trimethylsilyl)acetamide, hexamethyldisilazane, and 1-(trimethylsilyl)imidazole does not eliminate peak tailing. Column activity tests show that the PMP treatment also improves the peaks for 2,6-dimethyl aniline, 1-octanol, and 1-decanol implying a decrease in the column's hydrogen bonding sites with the PMP treatment. FT-IR analysis shows that exposure to PMP forms a bond to the stationary phase that deactivates the active sites responsible for organophosphonate peak tailing.

This paper describes a new bidirectional highpressure gas electrostatic microvalve that opens and closes in 50 [micro]s or less. The microvalve consists of a valve-closing electrode, a flexible movable membrane, and a valve-opening electrode that is directly opposed to the valve-closing electrode. The membrane contains an embedded electrode, so the valve can zip closed when a potential is applied between the membrane and the valve-closing electrode. The valve-opening electrode allows the valve to open again in a rapid discontinuous motion, without requiring a large applied potential. A pressure-balance port is used to enhance the microvalve switching speed and to allow the valve to close against applied pressures greater than 8.3 atm (840 kPa). The gas conductance through the valve is 2.8 nl/Pa . s (17 sccm/atm), and the fluid leakage measured zero over the entire pressure range up to a burst pressure of 10.8 atm (1.1 MPa). Measurements show that the valve can open or close in 50 [micro]s or less for applied pressures up to 126 kPa. In an extended lifetime test, a sample microvalve has been opened and closed 47 million times before failure. [2007-0037] Index Terms--Electrostatic microvalve, high pressure, microsecond, touch-mode capacitance.

This paper demonstrates a chemical surface modification method for covalent attachment of various polymers by using silane-based 'click' chemistry on silica surfaces and within glass microchannels suitable for CE systems. Modified surfaces are characterized by contact angle measurements, X-ray photoelectron spectroscopy, and Fourier transform infrared-attenuated total reflection spectroscopy. Electroosmotic flow (EOF) measurements in modified and unmodified channels are provided. Spectroscopic and transport data show that various polymers can be covalently attached to glass surfaces with a measurable change in EOF.

Silicon-based fuel cells are under active development for chip-scale electrical power supply. One of the greatest challenges in micro-fuel-cell research is the development of a suitable proton conducting membrane material that is compatible with standard silicon microfabrication technology. In this paper, the use of nanoporous silicon as a novel proton conducting membrane material in a microscale fuel cell membrane electrode assembly (MEA) is demonstrated. The devices were fabricated by first creating 100-[micro]m-thick silicon windows in a standard silicon wafer, anodizing to create pores in the windows, and then painting catalyst layers and insulators into the porous structures. Using 5 M formic acid and 0.5 M sulfuric acid as the fuel, the fuel cell peak power density reached about 30 mW/[cm.sup.2] at current density level of about 120 mA/[cm.sup.2]. These results represent the successful integration of a new class of protimic conductor into a microfabricated silicon fuel cell. [1455] Index Terms--Micro fuel cells, porous silicon.

The combined use of mathematical modeling and Auger depth profiling to study and quantify the oxidation of Ta films over a wide range of temperatures. The thermal oxidation of tantalum films is studied using direct measurements of species concentration by means of Auger depth profiling.

Integrating multiple analytical processes into microfluidic devices is an important research area required for a variety of microchip-based analyses. A microfluidic system is described that achieves preparative separations by intelligent fraction collection of attomole quantities of sample. The device consists of a main microfluidic channel used to perform electrophoresis, which is interconnected at 90[degrees] to two vertically displaced channels via a nanocapillary array membrane. The membrane interconnect contains nanometer-diameter pores that provide fluidic communication between the channels. Sample injection and analyte collection are controlled by application of an electrical bias between the microfluidic channels across the nanocapillary array. After the separation, the automated transfer of the FITC-labeled Arg, Gln, and Gly bands occurs; a fluorescence detector located at the separation/collection channel interconnect is used to generate a triggering signal that initiates suitable voltages to allow near-quantitative transfer of analyte from the separation channel to the second fluidic layer. The ability to achieve such sample manipulations from mass-limited samples enables a variety of postseparation processing events.

The extension of microfluidic devices to include three-dimensional fluidic networks allows complex fluidic and chemical manipulations but requires innovative methods to interface fluidic layers. Externally controllable interconnects, employing nuclear track-etched polycarbonate membranes containing nanometer-diameter capillaries, are described that produce hybrid three-dimensional fluidic architectures. Controllable nanofluidic transfer is achieved by controlling applied bias, polarity, and density of the immobile nanopore surface charge and the impedance of the nanocapillary array relative to the microfluidic channels. Analyte transport between vertically separated microchannels has three stable transfer levels, corresponding to zero, reverse, and forward bias. The transfer can even depend on the properties of the analyte being transferred such as the molecular size, illustrating the flexible character of the analyte transfer. In a specific analysis implementation, nanochannel array gating is applied to capillary electrophoresis separations, allowing selected separated components to be isolated for further manipulation, thereby opening the way for preparative separations at attomole analyte mass levels.

A design for a high temperature, HV insulator is presented. This design exploits the temperature dependent thermal and electrical properties of alumina and a unique structural insulator design to increase the high voltage hold-off characteristics of the insulator, reduce thermal flux through the insulator, and alleviate stresses caused by mismatch between insulator and electrode thermal expansion coefficients. The designed insulators insulate graphite electrodes at temperatures approaching 1000[degrees]C and potentials up to 50 kV. In this paper, the general methodology of designing these insulators is explored, and some limited performance data is presented. Index Terms--High voltage, high temperature, insulation, vacuum, design, cylindrical insulator.

Monte Carlo methods are often applied to the calculation of the apparent emissivities of blackbody cavities. However, for cavities with complex as well as some commonly encountered geometries, the emission Monte Carlo method experiences problems of convergence. The emission and absorption Monte Carlo methods are compared on the basis of ease of implementation and convergence speed when applied to blackbody sources. A new method to determine solution convergence compatible with both methods is developed, and the convergence speeds of the two methods are compared through the application of both methods to a right-circular cylinder cavity. It is shown that the absorption method converges faster and is easier to implement than the emission method when applied to most blackbody and lower emissivity cavities. OCIS codes: 000.4430, 120.4570, 230.6080, 300.2140.

The correlation between stress measurements and the derivation of P*, a stress powerlike quantity derived from measurements of transient stress-wave propagation, in solids subjected to high-power laser ablation was investigated. The effects of laser intensity, energy, beam size and target thickness were also examined. The results, which were obtained from laser-aluminum interactions, indicated the role of laser intensity, energy coupling and individual stress components on the value of P*.

This phenomenological inquiry sought to understand the impact that the alignment of a leader's espoused and practiced values has on an employee's organizational identification. The theoretical construct that undergirded this study was the social identity approach (SIA), which is composed of social identity theory (SIT) and self-categorization theory (SCT). We used a qualitative phenomenological inquiry to explore the lived experience of followers and revealed how they responded to the alignment/misalignment of their leaders' espoused and practiced values. We interviewed 10 participants from a multinational bank, with participants split equally between the staff in Ghana and Nigeria. The findings of this study helped explain the impact the alignment of leaders' values has on employees' organizational identification. [ABSTRACT FROM AUTHOR]