1,471 research outputs found
Sustained Release Drug Delivery Devices
A method and device for treating a mammalian organism to obtain a desired local or systemic physiological or pharmacological effect is provided. The method includes administering a sustained release drug delivery system to a mammalian organism in need of such treatment at an area wherein release of an effective agent is desired and allowing the effective agent to pass through the device in a controlled manner. The device includes an inner core or reservoir comprising the effective agent; a first coating layer, which is essentially impermeable to the passage of the effective agent; and a second coating layer, which is permeable to the passage of the effective agent. The first coating layer covers at least a portion of the inner core; however, at least a small portion of the inner core is not coated with the first coating layer. The second coating layer essentially completely covers the first coating layer and the uncoated portion of the inner core
Microwave-assisted synthesis and electrochemical evaluation of VO2 (B) nanostructures
Understanding how intercalation materials change during electrochemical operation is paramount to optimizing their behaviour and function and in situ characterization methods allow us to observe these changes without sample destruction. Here we first report the improved intercalation properties of bronze phase vanadium dioxide VO2 (B) prepared by a microwave-assisted route which exhibits a larger electrochemical capacity (232 mAh g-1) compared with VO2 (B) prepared by a solvothermal route (197 mAh g-1). These electrochemical differences have also been followed using in situ X-ray absorption spectroscopy allowing us to follow oxidation state changes as they occur during battery operation
Fast microwave-assisted synthesis of Li-stuffed garnets and insights into Li diffusion from muon spin spectroscopy
Lithium-stuffed garnets attract huge attention due to their outstanding potential as solid-state electrolytes for lithium batteries. However, there exists a persistent challenge in the reliable synthesis of these complex functional oxides together with a lack of complete understanding of the lithium-ion diffusion mechanisms in these important materials. Addressing these issues is critical to realizing the application of garnet materials as electrolytes in all solid-state lithium-ion batteries. In this work, a cubic phase garnet of nominal composition Li6.5Al0.25La2.92Zr2O12 is synthesized through a microwave-assisted solid-state route for the first time, reducing considerably the reaction times and heating temperatures. Lithium-ion diffusion behavior is investigated by electrochemical impedance spectroscopy (EIS) and state-of-art muon spin relaxation (mSR) spectroscopy, displaying activation energies of 0.55 0.03 eV and 0.19 0.01 eV respectively. This difference arises from the high inter-grain resistance, which contributes to the total resistance in EIS measurements. In contrast, mSR acts as a local probe providing insights on the order of the lattice, giving an estimated value of 4.6210􀀀11 cm2s􀀀1 for the lithium diffusion coefficient. These results demonstrate the potential of this lithium-stuffed garnet as a solid-state electrolyte for all-solid state lithium-ion batteries, an area of growing interest in the energy storage community
Coastline responses to changing storm patterns
Author Posting. © American Geophysical Union, 2006. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 33 (2006): L18404, doi:10.1029/2006GL027445.Researchers and coastal managers are pondering how accelerated sea-level rise and possibly intensified storms will affect shorelines. These issues are most often investigated in a cross-shore profile framework, fostering the implicit assumption that coastline responses will be approximately uniform in the alongshore direction. However, experiments with a recently developed numerical model of coastline change on a large spatial domain suggest that the shoreline responses to climate change could be highly variable. As storm and wave climates change, large-scale coastline shapes are likely to shift—causing areas of greatly accelerated coastal erosion to alternate with areas of considerable shoreline accretion. On complex-shaped coastlines, including cuspate-cape and spit coastlines, the alongshore variation in shoreline retreat rates could be an order of magnitude higher than the baseline retreat rate expected from sea-level rise alone.The Andrew W. Mellon Foundation, the
National Science Foundation Biocomplexity Program, and the Duke
University Center on Global Change supported this work
T-LAK cell-originated protein kinase (TOPK): an emerging target for cancer-specific therapeutics
‘Targeted’ or ‘biological’ cancer treatments rely on differential gene expression between normal tissue and cancer, and genetic changes that render tumour cells especially sensitive to the agent being applied. Problems exist with the application of many agents as a result of damage to local tissues, tumour evolution and treatment resistance, or through systemic toxicity. Hence, there is a therapeutic need to uncover specific clinical targets which enhance the efficacy of cancer treatment whilst minimising the risk to healthy tissues. T-LAK cell-originated protein kinase (TOPK) is a MAPKK-like kinase which plays a role in cell cycle regulation and mitotic progression. As a consequence, TOPK expression is minimal in differentiated cells, although its overexpression is a pathophysiological feature of many tumours. Hence, TOPK has garnered interest as a cancer-specific biomarker and biochemical target with the potential to enhance cancer therapy whilst causing minimal harm to normal tissues. Small molecule inhibitors of TOPK have produced encouraging results as a stand-alone treatment in vitro and in vivo, and are expected to advance into clinical trials in the near future. In this review, we present the current literature pertaining to TOPK as a potential clinical target and describe the progress made in uncovering its role in tumour development. Firstly, we describe the functional role of TOPK as a pro-oncogenic kinase, followed by a discussion of its potential as a target for the treatment of cancers with high-TOPK expression. Next, we provide an overview of the current preclinical progress in TOPK inhibitor discovery and development, with respect to future adaptation for clinical use
Phase Evolution and Li Diffusion in LATP Solid-State Electrolyte Synthesized via a Direct Heat-Cycling Method
Herein, the direct synthesis of phase-pure lithium aluminum titanium phosphate (Li_{1.3}Al_{0.3}Ti_{1.7}(PO_{4})_{3}, LATP) solid-electrolyte powder in 220 min and relatively low temperatures (850 °C) is achieved via a new (cyclic) fast heat treatment (c-FHT) route. The complex structural evolution highlights rate-limited lithium incorporation of intermediate metal phosphates formed prior to the final phase-pure LATP. The prepared LATP product powder displays similar bulk (2 × 10^{−10} cm^{2} s^{−1}) and local (3 × 10^{−10} cm^{2} s^{−1}) values for lithium diffusion coefficients (D_{Li}) characterized by electrochemical impedance spectroscopy and muon spin relaxation (μSR), respectively. The similarity between both D_{Li} values suggests excellent retention of inter- and intraparticle lithium diffusion, which is attributed to the absence of deleterious surface impurities such as AlPO4. A low-energy barrier (E_{a} = 73 meV) of lithium diffusion is also estimated from the μSR data
The Residential Mortgage (De)regulation–Innovation nexus
The stance of Australia’s central authorities with respect to residential mortgage innovation appears different from many of our international counterparts. In this article we provide an interpretation of this policy stance, concluding that signals are arguably a more prominent feature of Australia’s policy environment than many of our overseas counterparts. In addition we also observe that whilst there is a strong link between innovation and (de)regulation, a healthy degree of competition appears to be necessary if a wider-set of consumers are to have access to these innovations
Does innovation in residential mortgage products explain rising house prices? No.
Like many consumer products, household mortgages have experienced significant innovation in recent decades, with mortgages becoming cheaper, more accessible, and with more features. Many observers have expected that this would increase demand for houses, contributing to a rise in house prices. We investigate this relation, both in terms the extent and timing of innovation in residential mortgage products, and then we critically assess whether there is a link with Melbourne Metropolitan house prices (post 1980). Our conclusion is surprising: we find no apparent evidence of a relationship between residential mortgage innovation and house prices
The Residential Mortgage (De)regulation–Innovation nexus
The stance of Australia’s central authorities with respect to residential mortgage innovation appears different from many of our international counterparts. In this article we provide an interpretation of this policy stance, concluding that signals are arguably a more prominent feature of Australia’s policy environment than many of our overseas counterparts. In addition we also observe that whilst there is a strong link between innovation and (de)regulation, a healthy degree of competition appears to be necessary if a wider-set of consumers are to have access to these innovations
- …