Assessing the role of the biomaterial Aquavene in patient reactions to Landmark midline catheters

Generators of early cortical somatosensory evoked potentials (SEPs) still remain to be precisely localised. This gap in knowledge has often resulted in unclear and contrasting SEPs localisation in patients with focal hemispheric lesions. We recorded SEPs to median nerve stimulation in a patient with right frontal astrocytoma, using a 19-channel recording technique. After stimulation of the left median nerve, N20 amplitude was normal when recorded by the parietal electrode contralateral to the stimulation, while it was abnormally enhanced in traces obtained by the contralateral central electrode. The amplitude of the frontal P20 response was within normal limits. This finding suggests that two dipolar sources, tangential and radial to the scalp surface, respectively, contribute concomitantly to N20 generation. The possible location of the N20 radial source in area 3a is discussed. The P22 potential was also recorded with increased amplitude by the central electrode contralateral to the stimulation, while N30 amplitude was normal in frontal and central traces. We propose that the radial dipolar source of P22 response is independent from both N20 and N30 generators and can be located either in 3a or in area 4. This report illustrates the usefulness of multichannel recordings in diagnosing dysfunction of the sensorimotor cortex in focal cortical lesions.     

Washington State's late night retail worker crime protection regulation. Relationships with employer practices

Washington's late night retail worker crime protection regulation, enforced by the state Occupational Safety and Health Administration (OSHA) program, was intended to prevent injuries by deterring violent crimes. We investigated whether the regulation was associated with businesses' violence prevention activities. We surveyed 1,516 employers at high risk of robbery, including gas stations, groceries, hotels, restaurants, and taverns, in 1995 to determine whether they had violence prevention training programs for their employees (a requirement of the standard). Awareness of the regulation was low (4.4%). Employers covered by the regulation were more likely to have programs (Odds Ratio [OR] = 1.4), as were those aware of a regulation (OR = 3.4). State OSHA plan contact (an inspection or consultation) was also associated with having a program (OR = 1.9). Despite low awareness of the standard, results suggested that regulatory efforts to protect high-risk employees were associated with employers' robbery and crime prevention activities.     

Contingency ranking for bulk system reliability criteria

The use of outage data and models for multiple outages to examine the likelihood of various contingencies is addressed. The authors discuss sources of outage data, followed by an examination of line, generator, and transformer failures. The probabilities of various contingencies that planners examine were calculated, with consideration given to the likelihood of outages during abnormal cold winter weather. A contingency ranking table summarizes the results, showing which events are more or less likely. The rankings are the foundation for the Bonneville Power Administration deterministic planning criteria     

Optimum displacement for compound image generation in medical ultrasound

Incoherent averaging of measurements made at different look directions can be used to reduce speckle noise in medical ultrasound images. An analytic expression for the correlation between two measurements made at different spatial positions is derived. Using this expression, the optimum aperture displacement for efficient incoherent averaging (i.e. compounding) is computed and found to equal approximately one-half the aperture length.     

First- and second-harmonic radiations from a near-millimeter-wave gyromonotron

First- and second-harmonic radiations in frequency regions centered around 120 and 240 GHz, respectively, have been observed from a gyromonotron employing magnetic fields between 34 and 54 kG and a magnetron injection gun preducing a 30-kV, 1- to 2-A electron beam. Extensive redesign of the cavity, electron beam tunnel holders, and vacuum envelope resulted in greatly improved tube performance over that obtained previously. Nine first-harmonic modes and three second-harmonic modes were identified with specific TE cavity modes. These identifications were based on agreement between the measured frequency of a radiation and the calculated resonant frequency of a TE mode, and one or both of the following: (a) the agreement between the magnetic field at which the radiation occurred and that predicted by linear theory calculations of threshold current versus magnetic field for that mode; and (b) the similarity between the far-field antenna pattern measured with calibrated, waveguide-mounted detectors and that predicted for that mode. Output power was measured with a Scientech 362 Calorimeter and also estimated by integrating the far-field antenna patterns measured with the calibrated detectors. The power ranged from a fraction of a watt to 200 W for second-harmonic modes, and from tens of watts to 2 kW for first-harmonic modes.     

Upper extremity musculoskeletal disorders at a pulp and paper mill

A small cross-sectional study of upper extremity disorders was conducted in two departments of a pulp and paper mill. The objective of the study was to determine the prevalence of upper extremity disorders and identify any associated work place risk factors in long cycle jobs with multiple tasks of varying duration. Physical exams and health status interviews were conducted on 23 employees (77%) in the paper machine department and on 17 employees (59%) of the power and recovery department. All participants completed questionnaires on physical and psychosocial job characteristics. There was a statistically significant difference in hand and wrist disorders between the two departments at the p < 0.05 level (34.8% in the power and recovery department, and 5.9% in the paper machine area). Multiple logistic regression models showed a significant relationship between the use of a steel lance and shoulder disorders. Elbow arthritis was also associated with lance usage. There was evidence that the job analysis was not able to fully describe the risk factors present in the paper machine department. Biomechanical exposures existing prior to the time of the study may not have been adequately characterized. An important aspect of this study is that the jobs studied were not typical repetitive jobs that are commonly studied.     

Maximizing Capacity Usage and Selection of Optimal Antennas to Improve Spectrum Efficiency in Massive MIMO Technology

The performance of Massive MIMO can be enhanced by utilizing a large number of antennas than used and signifying its enormous capabilities in upgrading spectral efficiency. Antenna Selection is a low-priced complexity that decreases the number of radiofrequency chains with the contemplation of augmenting channel capacity. In this paper, an Augment Antenna Selection algorithm based on maximum flow minimum cut theorem is proposed which captures the optimal antennas based on the aggregate capacity of the possible antenna combinations. The first step in this algorithm proposes a subset of antennas to compute the augment paths and the second step selection considers the remaining capacity present in antennas to compute the maximum flow in a network. Thus, this algorithm that selects optimal antennas with better channel conditions aims at improving spectrum and energy efficiency. Simulation results show the outage capacity and the performance of BER with 64*64 and 128*128 Massive MIMO versus SNR has been analyzed.

     

Improving the gastrointestinal safety of NSAIDs: the development of misoprostol--from hypothesis to clinical practice

Arthritis is a major source of disability for the American population. It results in significant morbidity for the millions of patients affected and costs billions of dollars yearly for diagnosis and management. Nonsteroidal antiinflammatory drugs (NSAIDs) are the principal therapy for the majority of arthritis patients. It has been estimated that more than 15 million people with arthritis take these drugs daily. This use is predicted to increase greatly not only as a result of an aging population, with the consequent increase in the prevalence of arthritis, but also because NSAIDs may prove to have a role in decreasing colonic neoplasia and in reducing the likelihood of conditions such as Alzheimer's disease. It is therefore increasingly important to understand the nature of the side effects associated with these agents as well as ways of decreasing or preventing their occurrence. NSAIDs inhibit the enzymes cyclooxygenase-1 and cyclooxygenase-2. This reduces the synthesis of prostaglandins and therefore decreases joint inflammation, but it may also lead to the development of gastric and duodenal ulcers. For this reason, exogenous prostaglandins have been studied for their potential role in preventing NSAID-associated ulcers and ulcer complications. This paper reviews the development of the prostaglandin E1 analog misoprostol, the theory behind its use as a mucosal protective agent, and the results of studies in animals as well as in normal volunteers and patients with arthritis. Ultimately, a study was performed to evaluate whether misoprostol reduces the incidence of serious ulcer complications in patients taking NSAIDs. It is an interesting story, which promises to be of increasing importance as NSAID use expands to new indications while concern remains about their associated complications, especially those related to the gastrointestinal tract.     

A prospective experience with selective cholangiography

A prospective study of patients with symptomatic cholelithiasis was undertaken to determine the effectiveness of identifying clinically significant choledocholithiasis with selective cholangiography. Between 1991 and 1995, 262 patients presented to the senior author (K.W.M.) with acute or chronic cholecystitis. Sixteen patients had a preoperative endoscopic retrograde cholangiopancreatography (ERCP) for an elevated alkaline phosphatase or total bilirubin greater than twice the normal value or an ultrasound finding suspecting choledocholithiasis. Ten of the ERCP patients had choledocholithiasis, with eight patients having successful clearance by ERCP. Ninety other patients had intraoperative cholangiography for abnormal serum liver biochemistries, a history of jaundice or pancreatitis, or a dilated common bile duct (CBD) (>6 mm) on ultrasound. Fourteen of the intraoperative cholangiography patients and the two remaining ERCP patients had choledocholithiasis requiring CBD exploration for clearance of their stones. There were no false-positive cholangiograms, and there were no bile duct injuries in this series. With 100 per cent follow-up of at least 2 years, only one patient required ERCP clearance of a retained CBD stone 13 months after cholecystectomy. The positive predictive value and the negative predictive value for the selective cholangiography criteria are 23 per cent and 99 per cent, respectively. In conclusion, clinically significant choledocholithiasis can be found effectively with selective cholangiography. Also, utilizing selective cholangiography reduces the number of routine cholangiograms by 60 per cent.