Compression molding of biodegradable drug‐eluting implants for sustained release of metronidazole and doxycycline

The purpose of this report was to develop solvent‐free biodegradable drug‐eluting implants that provide sustained release of metronidazole and doxycycline. The drug‐eluting implants were prepared using the compression molding technique. To fabricate the implants, polylactide‐polyglycolide copolymers were premixed with metronidazole or doxycycline. The mixture was then compression molded and sintered to form implants of various sizes and geometries. An elution method and an HPLC assay were used to characterize the in vitro release rates of the antibiotics over a 28‐day period. A bacterial inhibition test was also carried out to determine the bioactivity of released antibiotics. The concentrations of both metronidazole and doxycycline were much greater than the minimum inhibitory concentration of Escherichia coli for up to 3 and 4 weeks, respectively, and the bioactivities of the antibiotics remained high after the fabrication process. Furthermore, the initial burst could be minimized and the release rate could be reduced by increasing the size of the implants and by adopting low drug to polymer ratios. By using this compression molding technique and appropriate processing parameters, we will be able to fabricate biodegradable implants of various types of antibacterial drugs for long‐term local deliveries. Eventually, biodegradable drug‐eluting implants may be used to treat various periodontal diseases. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Deletion of cell division cycle 2-like 1 gene locus on 1p36 in non-Hodgkin lymphoma

Our laboratories have documented a significantly high occurrence of chromosome 1p36 rearrangements in non-Hodgkin lymphoma (NHL). The cell division cycle 2-like 1(CDC2L1) (also known as TP58 or PITSLRE) gene, a protein kinase implicated in apoptotic signaling, is located at the very distal region of chromosome 1p36 and is likely to be disrupted by structural rearrangements involving 1p36. To determine the molecular consequences of the recurrent involvement of the 1p36 region, we examined metaphases containing 1p36 abnormalities from 31 specimens derived from 26 patients for the possible deletion of CDC2L1 by fluorescence in situ hybridization (FISH) using the TP58clk-1 DNA probe. Twenty-three cases exhibited the loss of CDC2L1 from the abnormal chromosome 1. In 2 of 26 cases, the gene locus was translocated to the partner chromosome, and in four specimens, all derived from one case, CDC2L1 was not deleted. This pilot investigation suggests that 1p36 rearrangements, and consequently the loss of the CDC2L1 gene locus, is important in NHL. This work also opens avenues for further molecular studies and prognostic correlations.     

Manipulating microstructure and mechanical properties of CuO doped 3Y-TZP nano-ceramics using spark-plasma sintering

Nano-powder composites of 3Y-TZP doped with 8 mol% CuO were processed by spark-plasma sintering (SPS). A 96% dense composite ceramic with an average grain size of 70 nm was obtained by applying the SPS process at 1100 °C and 100 MPa for 1 min. In contrast to normal, pressureless, sintering during SPS reactions between CuO and 3Y-TZP were suppressed, the CuO phase was reduced to metallic Cu, while the 3Y-TZP phase remained almost purely tetragonal. Annealing after SPS results in grain growth and tetragonal to monoclinic zirconia phase transformation. The grain size and monoclinic zirconia phase content are strongly dependent on the annealing temperature. By combining the processing techniques studied in this work, including traditional pressureless sintering, properties of the composite ceramic can be tuned via manipulation of microstructure. Tuning the mechanical properties of dense 8 mol% CuO doped 3Y-TZP composite ceramic by utilising different processing techniques is given as an example.     

Simple thinking on energy

It's good to see that the DTI has set up a streamlined ‘one stop shop’ to help offshore wind developers navigate through the maze of consents needed from the various licensing and regulatory bodies to get the necessary planning permissions for their bold new wind projects. But this seems the exception rather than the rule. As Dave Elliott, Open University argues, we are in danger of drowning in administrative complexity in the UK.     

Fundamentals of MRAM Technology

Developments in portable communication and computing systems are creating a growing demand for nonvolatile random access memory that is dense and fast. None of the existing solid-state memories can provide all the needed attributes in a single memory solution. Therefore, to achieve the required multiple functionality requirements, a number of different memories are being used while compromising performance and adding cost to the system. Magnetoresistive Random Access Memory (MRAM) has the potential to replace these memories in various systems with a single, universal memory solution. Key attributes of MRAM technology are nonvolatility and unlimited read and write endurance. In addition, MRAM can operate at high-speed and is expected to have competitive densities. In this paper we describe several fundamental technical and scientific aspects of MRAM with emphasis on recent accomplishments that enabled our successful demonstration of a 256 kbit memory chip.     

Effect of essential fatty acid depletion on tissue phospholipid fatty acids in spontaneously hypertensive and normotensive rats

Weanling male spontaneously hypertensive (SHR) and normotensive (WKY) rats were maintained on a fat-free semisynthetic diet and killed at various intervals. The effects of fat-depletion on the appearance of essential fatty acid (EFA) deficiency symptoms, the progressive changes of major fatty acids in plasma, liver, heart, and kidney phospholipids (PL), and in skin total lipids were compared between these two strains. After five weeks on the diet, the slower growth and the appearance of EFA deficiency symptoms became evident in SHR. In general, fat-depletion reduced the levels of n−6 fatty acids, whereas it increased those of 20∶3n−9. However, the fat-depletion induced reduction of 18∶2n−6 in heart PL and 20∶4n−6 in kidney, while the elevation of 20∶3n−9 in plasma, heart, and kidney PL were greater in WKY than in SHR. As a result, the elevation of biochemical EFA deficiency index—20∶3n−9/20∶4n−6 ratio—was greater in WKY than in SHR. In comparison with WKY, the concentrations of liver triacylglycerols and the weights of adipose tissues in SHR were reduced to a greater extent, indicating an active catabolism of triacylglycerols in SHR. This study suggests that the earlier appearance of morphological symptoms of EFA deficiency in SHR was not associated with the reducing n−6 EFA levels or with an elevation of triene/tetraene ratio, but possibly to a reduced supply of n−6 EFA for skin prostaglandin synthesis.     

Ethnography,ethnomethodology and the problem of generalisation in design

This paper discusses the relationship between sociological theory and method, ethnomethodology and design. It argues that social science theoretical and methodological interests cannot form a basis for interdisciplinarity. Much of the argument about the relevance of ethnography for design, and more specifically about ethnomethodological enquiry, has been cast firstly as problems of method and secondly in terms of the problem of generalisation. We argue that in both instances the problem is miscast. Drawing on the arguments of Wittgenstein and Winch, we suggest that forms of generalisation are to be found in ethnomethodological enquiry and that they may be useful in design-related enquiry. We further suggest, however, that they are not the forms to be found in explanatory social science.     

Implementing a bespoke supply chain management system to deliver tangible benefits

Companies often focus efforts to improve business efficiencies on internal systems and significant benefits can be achieved by so doing. However, the magnitude of the realised benefit is restricted if only processes within the organisation are targeted for improvement. This paper describes the implementation of a bespoke web-based supply chain management system/online collaboration system. The main drivers behind the development of the system were late deliveries from the supplier and also sporadic and inaccurate delivery schedule information from the supplier. The implementation approach is discussed along with the problems that were encountered en route and the measures that were undertaken to ensure that implementation was successful. The importance of metrics is stressed, as these are essential if any improvements are to be quantified. The metrics enable justification of such projects in financial terms which is compounded by the ‘soft’ benefits that result from the use of such systems.     

Delayed internal capsule infarctions following radiofrequency pallidotomy. Report of three cases

The authors report on a series of patients with idiopathic Parkinson's disease (IPD) who underwent stereotactic radiofrequency (RF) pallidotomies, three of whom suffered delayed postoperative strokes. These three belonged to a group consisting of 42 patients with medically intractable IPD in whom 50 pallidotomies were performed. All three patients had significant previous vascular disease and were in a high-risk group for cerebral infarction. A postoperative magnetic resonance (MR) image was obtained immediately after the pallidotomy was performed to document the placement of the RF lesion and to rule out any hematoma. The delayed strokes occurred on postoperative Days 10, 51, and 117 in patients with previous vascular disease (Group 1, 11 patients). No strokes occurred in the group with the vascular disease risk factor (Group 2, 11 patients) or in the group with no risk factors for vascular disease (Group 3, 20 patients). This observation is statistically significant (p < 0.05). The T2-weighted MR images showed the lesions as high-intensity signals extending to the posterior limb of the internal capsule ipsilateral to the pallidotomy site. The poststroke T1-weighted images obtained in two patients showed persistent contrast enhancement of the RF lesion and no enhancement around the stroke lesion. Clinically and radiographically, these discrete new lesions represent delayed infarctions, suggesting that RF lesioning can induce delayed injury in adjacent tissue. Patients with previously identified vasculopathy may be at risk for delayed capsular infarction following RF pallidotomy.