Skeletal muscle myosin heavy chain synthesis in type 1 diabetes

Although insulin's anticatabolic effect on protein metabolism in type 1 diabetes has been clearly shown to be related to the inhibition of protein breakdown, insulin's effect on muscle protein synthesis remains controversial. Cross-limb studies and measurements of synthesis rates of mixed muscle protein have yielded conflicting results. These measurements represent the mean synthesis of several muscle proteins and may miss changes in the synthesis rates of individual muscle proteins. We measured the fractional synthesis rates of myosin heavy chain (MHC), the principal muscle contractile protein, and mixed muscle protein (MMP) in six type 1 diabetic patients during insulin deprivation and insulin treatment. Comparisons were made with six healthy control subjects. Muscle biopsies were taken at 2 h and 8 h during a primed continuous infusion of L-[1-13C]leucine. MHC was purified by a preparative continuous elution gel electrophoresis, and fractional synthesis rates were calculated. We found that in type 1 diabetic subjects, the fractional synthesis rates of MHC and MMP during insulin treatment are similar to those of control subjects. Acute insulin deprivation did not affect either the synthesis rate or the ratio of MHC to MMP in type 1 diabetic subjects. In the postabsorptive state, acute insulin deprivation has no effect on MHC or MMP synthesis in type 1 diabetic patients.     

Design-to-testing: a low-power, 1.25 GHz,single-bit single-loop continuous-time $$\Delta \Sigma$$ modulator with 15 MHz bandwidth and 60 dB dynamic range

Continuous-time Delta-Sigma (CT-\(\Delta \Sigma\)) analog-to-digital converters have been extensively investigated for their use in wireless receivers to achieve conversion bandwidths >15 MHz and higher resolution of 10–14 bits. This paper presents the complete design-to-testing tutorial of a state-of-the-art high-speed single-bit CT-\(\Delta \Sigma\) architecture and its circuit design details in 0.13 μm CMOS technology node sampling at 1.25 GS/s. The designed modulator achieves higher dynamic range of 60 dB in a wide conversion bandwidth of 15 MHz and consumes only 3.5 mW. The proposed modulator achieves a Figure of Merit of 154 fJ/level.     

A 1 GS/s, 31 MHz BW, 76.3 dB dynamic range, 34 mW CT-\Updelta\Upsigma ADC with 1.5 cycle quantizer delay and improved STF

A 1 GS/s continuous-time delta-sigma modulator (CT- $\Updelta\Upsigma$ M) with 31 MHz bandwidth, 76.3 dB dynamic range and 72.5 dB peak-SNDR is reported in a 0.13 μm CMOS technology. The design employs an excess loop delay (ELD) of more than one clock cycle for achieving higher sampling rate. The ELD is compensated using a fast-loop formed around the last integrator by using a sample-and-hold. Further, the effect of this ELD compensation scheme on the signal transfer function (STF) of a feedforward CT- $\Updelta\Upsigma$ architecture has been analyzed and reported. In this work, an improved STF is achieved by using a combination of feed-forward, feed-back and feed-in paths and power consumption is reduced by eliminating the adder opamp. This CT- $\Updelta\Upsigma$ M has a conversion bandwidth of 31 MHz and consumes 34 mW from the 1.2 V power supply. The relevant design trade-offs have been investigated and presented along with simulation results.     

Isolation of myosin heavy chain from small skeletal muscle samples by preparative continuous elution gel electrophoresis: application to measurement of synthesis rate in human and animal tissue

We studied seven patients aged 14 to 40 years who received living-related kidney transplants and had allograft survivals of 26 to 29 years. The blood urea and creatinine were either within normal limits or marginally elevated. Histopathologic examination showed only mild mesangial expansion, interstitial fibrosis, and arteriosclerosis. Immunoperoxidase staining with anti-HLA antibodies or in situ hybridization with a Y chromosome probe showed persistence of donor tubular epithelium and vascular endothelium within the graft. Recipient-derived glomerular cells were seen in one case, and interstitial lymphocytic infiltrates were seen in all cases. A review of the clinicopathologic data available for these cases indicated that both central and peripheral immunologic mechanisms contributed to the maintenance of prolonged graft survival. This extended survival was independent of six antigen matching, down-regulation of donor HLA antigen expression, and ingrowth of host epithelium/endothelium into the allograft.     

PCR-ELISA for the early diagnosis of invasive pulmonary aspergillus infection in neutropenic patients

This paper outlines criteria which allow the clinician to identify endodontically treated teeth that can be restored with a high level of predictability. The intent of the article is not to preclude the restoration of teeth that do not meet these criteria; it is to provide a science-based approach for identifying those teeth with a high probability of long-term success upon restoration. For an endodontically treated tooth not requiring a post, the requirements are for biologic width + ferrule length, (i.e. 4.5 mm of supra-bony solid tooth--dentin a minimum of 1 mm thick after preparation). A tooth requiring a post needs, in addition, enough root length to allow a 4 mm apical seal and a post length--apical to the crown margin, equal to the length of the crown. It is essential to assess the functional loads to which the restored tooth would be subjected. Teeth that are endodontically treated, or are likely to be in future, should be avoided as abutments supporting precision attachment RPDs, distal extension RPDs or cantilever FPDs.     

Evaluation of ferritic stainless steel for use as metal interconnects for solid oxide fuel cells

Interconnect development for planar solid oxide fuel cells is considered a vital technical area requiring focused research to meet the performance and cost goals. A commercial ferritic stainless steel composition for oxidation resistance properties was investigated by measuring the weight gain due to air exposure at fuel cell operating temperature. A surface treatment process was found to produce a dense, adherent scale and to reduce the oxide scale growth rate significantly. A process was also identified for coating the surface of the alloy to reduce the in-plane resistance and potentially to inhibit chromium oxide evaporation. The combination of treatments provided a very low resistance through the scale. The resistance measured was as low as 10 mΩ-cm² air. The resistance value was stable over several thermal cycles. The treated samples were exposed to a variety of atmospheres that were relevant in fuel cell operation to evaluate changes in scale morphology. Analysis of the scale after such exposure showed the presence of a stable composition. When exposed to a dual atmosphere (air and hydrogen on opposite sides of the metal sheet), however, the scale composition contained a mixture of phases. Additional process modifications are planned to reduce the effect of dual-atmosphere exposure. This paper was presented at the Fuel Cells: Materials, Processing, and Manufacturing Technologies Symposium sponsored by the Energy/Utilities Industrial Sector & Ground Transportation Industrial Sector and the Specialty Materials Critical Technologies Sector at the ASM International Materials Solutions Conference, October 13–15, 2003, in Pittsburgh, PA. The symposium was organized by P. Singh, Pacific Northwest National Laboratory. S.C. Deevi, Philip Morris USA, T. Armstrong, Oak Ridge National Laboratory, and T. Dubois, U.S. Army CECOM.     

Selection and surface treatment of alloys in solid oxide fuel cell systems

Cost and performance considerations determine the selection of various component materials in a solid oxide fuel cell power system. While the use of commercial alloys provides an opportunity for cost reduction, the requirements of different components vary widely. The interconnect materials must provide low electrical resistance while isolating the oxidizing and reducing gases. The air preheat and heat-exchanger components face high-temperature oxidizing conditions, while the fuel feed and reformer sections encounter highly reducing atmospheres that may contain varying levels of sulfur and CO, and thus are prone to sulfidation and metal dusting. Thus, each of the components requires both a judicious selection of the alloy composition and appropriate surface treatments. Coating processes were developed for two classes of alloy materials for potential use as interconnects and fuel feed hardware or process piping. This paper was presented at the ASM Materials Solutions Conference & Show held October 18–21, 2004 in Columbus, OH.     

Colloidal processing of sol-sprayed ceramic particulate composites

Sol-gel based preparative procedures are capable of reducing the problems of particle size distribution, purity and homogeneity of the phases in ceramic particulate composites. However, the tendency for agglomeration of these powders creates serious problems for processing to shapes. The present work is a critical study of the preparation of 10% ceria-alumina composite particulates, by a mixed sol-spray technique followed by pressure filtration for final consolidation. The powder was also compacted by ceramic uniaxial dry pressing for comparison purposes. The details of powder preparation, powder characteristics, filtration conditions, compaction and sintering behaviour and the final sintered microstructural features of the compacts have been studied and evaluated.