520 research outputs found
Aa Unbalanced Feed Design for Wideband Phased Arrays
In this work, a planar phased array antenna was engineered with
ultra-wideband (UWB) performance that covers portions of the L-, S-, and
C-bands. The unit cell design contains a driven layer that is directly
connected to a single coaxial feed and a parasitic layer located above the
driven layer separated by free space. This design does not require a balun or
any vias between the antenna ground plane and the driven layer, resulting in a
simple antenna stack-up consisting of only planar layers, aside from the feed
structure. As a consequence, the complexity, and potentially sensitivity to
mechanical tolerances, is reduced. The simulated results of this unbalanced
phased array are discussed and experimentally validated.Comment: 6 pages, 5 figures, ITC/USA conferenc
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Understanding physicians’ behavior toward alerts about nephrotoxic medications in outpatients: a cross-sectional analysis
Background: Although most outpatients are relatively healthy, many have chronic renal insufficiency, and high override rates for suggestions on renal dosing have been observed. To better understand the override of renal dosing alerts in an outpatient setting, we conducted a study to evaluate which patients were more frequently prescribed contraindicated medications, to assess providers’ responses to suggestions, and to examine the drugs involved and the reasons for overrides. Methods: We obtained data on renal alert overrides and the coded reasons for overrides cited by providers at the time of prescription from outpatient clinics and ambulatory hospital-based practices at a large academic health care center over a period of 3 years, from January 2009 to December 2011. For detailed chart review, a group of 6 trained clinicians developed the appropriateness criteria with excellent inter-rater reliability (κ = 0.93). We stratified providers by override frequency and then drew samples from the high- and low-frequency groups. We measured the rate of total overrides, rate of appropriate overrides, medications overridden, and the reason(s) for override. Results: A total of 4120 renal alerts were triggered by 584 prescribers in the study period, among which 78.2% (3,221) were overridden. Almost half of the alerts were triggered by 40 providers and one-third was triggered by high-frequency overriders. The appropriateness rates were fairly similar, at 28.4% and 31.6% for high- and low-frequency overriders, respectively. Metformin, glyburide, hydrochlorothiazide, and nitrofurantoin were the most common drugs overridden. Physicians’ appropriateness rates were higher than the rates for nurse practitioners (32.9% vs. 22.1%). Physicians with low frequency override rates had higher levels of appropriateness for metformin than the high frequency overriders (P = 0.005). Conclusion: A small number of providers accounted for a large fraction of overrides, as was the case with a small number of drugs. These data suggest that a focused intervention targeting primarily these providers and medications has the potential to improve medication safety
Demography of Dialysis and Transplantation in Children in Europe, 1985: Report from the European Dialysis and Transplant Association Registry
At the end of 1985 there were 5482 patients known to the Registry who started renal replacement therapy (RRT) between the ages of 6 months and 15 years. Of these, approximately 25% had died, 30% were still aged less than 15 years, and the other 45% were older. The acceptance rate of new patients over the last 10 years has slowly but steadily increased; six new paediatric patients per million child population probably represents the likely needs of the near future. Hospital haemodialysis remained the main form of renal replacement therapy in new patients, while 3 years after start of RRT, transplantation became the most frequently used replacement therapy; CAPD appeared to be used mainly in children with a short waiting time for transplantation. Out of the 384 grafts reported in 1985, only 16% were from living related donors; among 321 cadaver grafts, 24% were second and only 3% were third grafts. Glomerulonephritis and pyelonephritis accounted for 50% of all primary renal diseases. During the last 5 years, the proportion with glomerulonephritis seems to have decreased slightly. Hyperkalaemia and fluid overload have still to be considered the main causes of death. Only in 17% of all cases was the cause of death reported as unknown or undetermine
Demography of Dialysis and Transplantation in Europe, 1984: Report from the European Dialysis and Transplant Association Registry
The demography of treatment of children by renal replacement therapy in Europe is presented based on returns of individual patient questionnaires to the EDTA Registry up until the close of 1984. Patient questionnaires for 1984 were completed by all centres which defined themselves as special paediatric units. A total of 4983 patients have been reported to the Registry up until 31 December 1984 as having commenced renal replacement therapy under the age of 15. Of these, 1570 were known to be alive on a defined form of treatment at the end of 1984 and still under the age of 15. The numbers of these patients kept alive by different forms of treatment in individual countries are presented. The stock of patients aged under 15 at the end of 1984 exceeded 30 per million child population in Belgium, France, Iceland and Luxembourg. The highest age specific acceptance rates for children onto renal replacement therapy during 1984 were noted in those aged between 10 and 14 at first treatment. Age specific acceptance rates for children varied greatly between individual countries, and 18 countries reported no new patients under the age of 5 during 1984. Transplant activity in paediatric patients during 1984 has been analysed and results on regrafting presented. Proportional distribution of primary renal diseases amongst children commencing therapy in 1984 is shown according to age at start of treatment. Haemolytic uraemic syndrome was reported as the cause of end-stage renal failure in 12.0% of children commencing treatment under the age of 5, and 12.3% of children between 5 and 9. Finally, information on cause of death in paediatric patients dying during 1984 is presented, and shows cardiovascular disease was the leading cause of mortalit
EDTA Registry Centre Survey, 1985: Report from the European Dialysis and Transplant Association Registry*
This paper summarises the information given on the 1985 EDTA Registry centre questionnaire which was returned by 82% of 1959 known dialysis and transplant units in 33 European countries. Trends in the use of different forms of renal replacement therapy are discussed, and attention drawn to the discrepancy between the EDTA centre and individual patient questionnaires as a source of demographic information on dialysis and transplantation. The results of special questions on dialyser re-use, dialysis equipment, AIDS, and hepatitis are presented, and information obtained from the special paediatric section of the centre questionnaire is also give
EDTA Registry Centre Survey, 1986: Report from the European Dialysis and Transplant Association Registry
This paper summarises the information given on the 1986 EDTA Registry centre questionnaire which was returned by 82% of the 2,065 known dialysis and transplant centres in 33 European countries. Information is given on the number of patients alive on haemodialysis according to the type of dialysis facilities available where the patient was receiving dialysis and the number of patients receiving special types of dialysis. The centre questionnaire also included questions on testing for HIV infection, serological evidence or symptoms of AIDS and the diagnosis of hepatitis B in patients and staff. The data given in response to these questions are presented together with data on the involvement of dietitians and social workers in the treatment of patients with end stage renal failure. Finally, information on transplant activity in Europe and the treatment policies of transplanting centres is provide
Kidney Transplantation in Primary Oxalosis: Data From the EDTA Registry
This paper reports the results of 98 first kidney transplantations in patients with oxalosis as the primary renal disease as recorded by the EDTA Registry. There were 79 patients who received a cadaveric (CAD) graft and 15 patients with a living related donor (LRD) graft; the type of donor was not recorded for four patients. Initial graft survival appeared to be better after LRD as compared to CAD grafts but at 3 years the poor survival was similar with 23% for LRD and 17% for CAD grafts. CAD graft survival did not differ between children and adults and was not affected by the waiting time on dialysis. A slight improvement was observed in grafts performed in the years 1983-1986 as compared to grafts performed in earlier years. The causes of failure reported were mainly rejection (33%) and recurrence of primary renal disease (31%). In view of the poor results related to recurrence of oxalosis in the graft, the potential ofcombined kidney and liver transplantation is discusse
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