A 24-GHz 3.9-dB NF low-noise amplifier using 0.18 /spl mu/m CMOS technology

A 24-GHz low-noise amplifier (LNA) was designed and fabricated in a standard 0.18-/spl mu/m CMOS technology. The LNA chip achieves a peak gain of 13.1 dB at 24 GHz and a minimum noise figure of 3.9 dB at 24.3 GHz. The supply voltage and supply current are 1 V and 14 mA, respectively. To the author's knowledge, this LNA demonstrates the lowest noise figure among the reported LNAs in standard CMOS processes above 20 GHz.     

Accelerated wear testing with a microfabricated surface to evaluate the lubrication ability of biomolecules on polyethylene

Wear of ultrahigh‐molecular‐weight polyethylene (UHMWPE) and wear‐particle‐induced osteolysis and bone resorption are the major factors causing the failure of total joint replacements. It is feasible to improve the lubrication and reduce the wear of artificial joints. We need further understanding of the lubrication mechanism of the synovial fluid. The objective of this study is to evaluate the lubricating ability of three major components in the synovial fluid: albumin, globulin, and phospholipids. An accelerated wear testing procedure in which UHMWPE is rubbed against a microfabricated surface with controlled asperities has been developed to evaluate the lubrication behavior. An analysis of the wear particle dimensions and wear amount of the tests has provided insights for comparing their lubrication performance. It is concluded that the presence of biomolecules at the articulating interface may reduce friction. A higher concentration of a biological lubricant leads to a decrease in the wear particle width. In addition, in combination with the wear results and mechanical analysis, the roles of individual biomolecules contributing to friction and wear at the articulating interface are discussed. These results can help us to identify the role of the biomolecules in the boundary lubrication of artificial joints, and further development of lubricating additives for artificial joints may be feasible. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Familial ring (19) chromosome mosaicism: case report and review

Ring (19) chromosomal mosaicism has been identified in a 14-month-old girl referred for cytogenetic evaluation due to microcephaly and developmental delay with autistic-like mannerisms. An analysis of her peripheral blood lymphocytes showed a 46,XX,r(19) cell line in 119/121 of cells examined. Of the two remaining cells, one had a normal female chromosome complement and the other showed loss of one of the chromosome 19 homologs. Further analysis by fluorescence in situ hybridization using an all human telomere probe showed the presence of a single hybridization signal on the r(19) chromosome. Subsequent cytogenetic characterization of cells derived from the patient's phenotypically normal mother also demonstrated the presence of a ring 19 chromosome in 4/100 cells. The remaining cells had a normal female chromosome complement. These findings represent the first reported case of familial ring 19 mosaicism. The cytogenetic and clinical findings in these two individuals are discussed in relation to six previously reported cases of de novo ring chromosome 19 mosaicism.     

Imaging evaluation of artificial nipples during bottle feeding

OBJECTIVE: To report a case of probable famotidine-induced mixed hepatocellular jaundice. CASE SUMMARY: A 55-year-old man presented with a one-month history of mid-epigastric pain. Initial physical examination and laboratory studies, including liver enzyme concentration tests, were unrevealing. A diagnosis of gastritis was made and ranitidine was prescribed. Following one week of therapy, the patient's symptoms had not improved and therapy was changed to famotidine and sucralfate. Approximately one week later the patient presented with jaundice. Liver enzyme concentrations were elevated and the patient was hospitalized for further evaluation. Five days following discontinuation of famotidine, liver enzyme concentrations were normal and jaundice had resolved. Further tests did not reveal any pathologic etiology. DISCUSSION: Hepatic changes have occurred in patients receiving histamine2-antagonists; ranitidine and cimetidine have been cited most frequently. In general, the elevations are mild, transient, and return to baseline with continued therapy. This is one of the first case reports of probable famotidine-induced mixed hepatocellular jaundice. CONCLUSIONS: There was a temporal relationship between the patient's signs and symptoms and initiation of famotidine. No identifiable factors contributed to the elevated liver enzyme concentrations and jaundice.     

Estimation and hypothesis testing of treatment effects in animal reproductive toxicology studies

Healy (1) and Dempster et al. (8) proposed statistical methods to evaluate the treatment effects in animal reproductive toxicology research. Both methods assume homogeneous variance for the dams and the pups, respectively, in all the treatment groups. In this paper, via mixed effect modeling, we propose a method to estimate the treatment effects allowing heterogeneous variances for the dams and the pups, respectively, in different treatment groups. Covariates will also be included in the model. A procedure to test the fixed effects is also discussed. An example from an animal reproductive toxicological study is used to illustrate the procedures.     

Feasibility of adding a personal communications network to anexisting fixed-service microwave system

This paper examines the feasibility of adding a personal communication network (PCN) to a frequency band which is already allocated to fixed-service microwave systems. To achieve this goal, spread spectrum techniques are used to spread narrowband PCN signals into wideband. The forward and reverse link performance of PCN users under the influence of the microwave system and the influence of PCN users on the microwave system are both examined. It is proven that spectrum sharing between the PCN network and microwave systems is indeed feasible. Although our analysis is done based upon the consideration of only one microwave system, it can be easily extended to allow the appearance of two or more microwave systems     

Percutaneous balloon pericardiotomy for patients with recurrent pericardial effusion: using a novel double-balloon technique with one long and one short balloon

Percutaneous balloon pericardiotomy is effective and less invasive for the treatment of recurrent pericardial effusion. This study suggests that the double-balloon method with 1 longer and 1 shorter balloon is the procedure of choice for percutaneous balloon pericardiotomy.     

Multicluster,mobile, multimedia radio network

A multi-cluster, multi-hop packet radio network architecture for wireless adaptive mobile information systems is presented. The proposed network supports multimedia traffic and relies on both time division and code division access schemes. This radio network is not supported by a wired infrastructure as conventional cellular systems are. Thus, it can be instantly deployed in areas with no infrastructure at all. By using a distributed clustering algorithm, nodes are organized into clusters. The clusterheads act as local coordinators to resolve channel scheduling, perform power measurement/control, maintain time division frame synchronization, and enhance the spatial reuse of time slots and codes. Moreover, to guarantee bandwidth for real time traffic, the architecture supports virtual circuits and allocates bandwidth to circuits at call setup time. The network is scalable to large numbers of nodes, and can handle mobility. Simulation experiments evaluate the performance of the proposed scheme in static and mobile environments.This work was supported by the U.S. Department of Justice/Federal Bureau of Investigation, ARPA/CSTO under Contract J-FBI-93-112 Computer Aided Design of High Performance Wireless Networked Systems.