Funneling light through a subwavelength aperture with epsilon-near-zero materials.

We present a comprehensive study of enhanced light funneling through a subwavelength aperture with realistic (lossy) epsilon-near-zero (ENZ) materials. We realize experimentally an inclusion-free ENZ material layer operating at optical frequencies and characterize its performance. An analytical expression describing light funneling through several structures involving ENZ coupling layers is developed, validated with numerical solutions of Maxwell equations, and utilized to relate the performance of the ENZ coupling systems to their main limiting factor, material losses.

Geriatric rehabilitation: nursing interventions and outcomes focusing on urinary function and knowledge of medications.

This article describes the nursing interventions that focus on urinary function and medication knowledge of older adults in a geriatric rehabilitation program. The authors review the interventions needed to achieve bladder retraining and self-administration of medication and consider what predicts urinary function and knowledge of medication administration in older adults. The descriptive study included 251 consecutive patients who were admitted into a geriatric rehabilitation unit. An evaluation of urinary function was done on admission and based on patient need to (a) maintain urinary function, (b) decrease urinary incontinence, and (c) resolve urinary retention. All patients received routine medication teaching from admission to discharge during each daytime administration of medication. From admission to discharge, there was a decrease in incidences of urinary incontinence and urinary retention and an increase in knowledge of medication regimens. Although the study was descriptive, the findings suggested that nursing interventions in geriatric rehabilitation may decrease urinary incontinence and retention and improve knowledge of medication regimens in this population.

Proximal tibial osteotomy in patients who are fifty years old or less. A long-term follow-up study.

Proximal tibial valgus osteotomy was performed for unicompartmental osteoarthritis in forty-five patients (fifty-one knees). The average age of the patients was forty-one years (range, twenty-three to fifty years), and the average length of follow-up was ten years. At follow-up, 70 per cent (thirty-six knees) were rated as good or excellent and 30 per cent (fifteen knees) were rated as fair or poor. There was no clear correlation between the quality of the result and the radiographic evidence of the severity of the arthritis preoperatively, the age of the patient at osteotomy, or the length of follow-up. There was a correlation between an improved result and an increased angle of correction after osteotomy, but the values were not statistically significant. The most important factor influencing the quality of results was the over-all level of disease in the knee as reflected in the preoperative knee score. Deficiency of the anterior cruciate ligament at the time of the osteotomy did not prevent a good result. We believe that proximal tibial osteotomy for unicompartmental arthritis of the knee is a good and effective procedure for patients who are less than fifty years old and who have an active life-style, and that lasting results can be achieved if the procedure is done early in the course of the disease.

Reconstruction procedures for anterior cruciate ligament insufficiency: a computer analysis of clinical results.

A pre- and postoperative study of 205 patients who had surgical reconstruction of the anterior cruciate ligament (ACL) of the knee was evaluated with the use of a prototype computer program. An average followup of 4.1 years revealed a 27% improvement in subjective complaints and a 8% improvement in objective findings. The anterior drawer test was improved 25% and subluxation of the lateral tibial plateau (ALRI) was improved 118% correlating highly (P less than 0.001) with a good result. Seventy-four percent of patients had undergone medial meniscectomy, 58% lateral meniscectomy, and 41% had both menisci removed at followup after reconstruction. Ninety-two percent of the 121 patients responding to a final subjective complaint evaluation felt that their knee was significantly improved (average 6.1 years after reconstruction). The computer demonstrated a wide variation in the results of reconstruction within the intraarticular, extraarticular, and combined groups. The addition of associated procedures to the main reconstructive procedure significantly affected the results. This study reveals improvement of subjective complaints and objective findings after reconstructing the anterior cruciate ligament and proposes the use of computer analysis for specific evaluation of different procedures.

Wedge recession for treatment of recurrent luxation of the patella: a preliminary report.

Wedge recession is a method which utilizes the geometry of similar triangles to recess an articular wedge into the underlying bone. This concept has been applied to congenital luxating patellae in the dog. A trochlear wedge recession deepens the femoral trochlea and provides stability to the patella. Preliminary trials of the procedure in dogs produced excellent results.

Isolation of a replication-defective murine leukaemia virus from cultured AKR leukaemia cells.

Mice of the AKR strain are characterised by a high incidence of spontaneous thymic lymphomas. AKR chromosomes contain the genomes of ecotropic murine leukaemia virus (MuLV) at two loci, termed Akv-1 and Akv-2 (refs 2-6). Shortly after birth, the normal tissues of AKR mice begin to produce high levels of this XC-positive MuLV (ref. 7) (that is, one that forms XC plaques). A second class of MuLV, termed mink cell focus-inducing virus (MCF), is produced specifically by preleukaemic and leukaemic AKR thymocytes. Nowinski et al. have established a series of tissue culture lines from AKR leukaemias and reported that the resulting cell lines produce virus particles, but that these particles, surprisingly, do not give rise to XC plaques. We have analysed the virus particles produced by one of these cell lines, termed AKRSL2. We show here that, unlike most or all of the nonmalignant tissues in the AKR mouse, these cultured lymphoma cells produce very little non-defective ecotropic MuLV; however, they do produce replication-defective ecotropic MuLV.

Cruciate ligament stents in reconstruction of the unstable knee. A preliminary report.

Cruciate ligament stents have been developed to severe as internal splints which provide excellent temporary stability while allowing full range of motion of the knee during postreconstruction rehabilitation. Forty-three patients with disabling chronic knee instability were treated at one center using similar reconstruction techniques with either the anterior or posterior cruciate stent. When both cruciate ligaments were absent, only the posterior was used. All stents are intended only as temporary internal splints and all patients were advised that the structures were expected to break eventually. Followup of 15 patients with anterior cruciate stents revealed only 50% satisfactory overall results. Overall results were satisfactory in 80% of 20 patients with posterior cruciate stents. Longer implant survival is needed, and this must be accomplished by building more flexibility into the stent core and by improving surgical technique with more precise instrumentation.

Rescue and transmission of a replication-defective variant of moloney murine leukemia virus.

We have described a clone of mouse cells, termed "8A," which appears to be infected with a replication-defective variant of Moloney murine leukemia virus (MuLV) (Rein et al., J. Virol. 25:146-156, 1978). Clone 8A cells release virus particles which do not form plaques in the standard XC test. However, approximately 10(2) particles per ml of clone 8A supernatant do form plaques in a modified XC test (the "complementation plaque assay"), in which the assay cells are coinfected with the XC-negative, nondefective amphotropic MuLV as well as the test virus. Superinfection of clone 8A cells themselves with amphotropic MuLV results in the production of approximately 10(5), rather than approximately 10(2), particles per ml which register in the complementation plaque assay. This increase is due to the rescue of replication-defective ecotropic MuLV from clone 8A cells by amphotropic MuLV since (i) this ecotropic MuLV can only form XC plaques in cells which are coinfected with amphotropic MuLV; and (ii) it is possible to transmit this defective variant, rescued from superinfected clone 8A cells, to a fresh clone of normal mouse cells. The time course of production of the rescued MuLV particles by superinfected clone 8A cells is virtually identical to that of rescue from these cells of murine sarcoma virus. Amphotropic MuLV superinfection of "NP-N" cells, which contain a "non-plaque-forming" variant of N-tropic MuLV (Hopkins and Jolicoeur, J. Virol. 16:991-999, 1975), also increases the titer of particles registering in the complementation plaque assay; thus, NP-N cells, like clone 8A cells, contain a rescuable defective variant of ecotropic MuLV.

The patellar compression syndrome: surgical treatment by lateral retinacular release.

Patellar compression syndrome may be a manifestation of contraction of the lateral retinacular structures which consists largely of the lateral patellofemoral ligament producing a tethering action on the patella. This may produce parapatellar pain, particularly in activities requiring repetitive knee flexion. Minor patellofemoral incongruencies with pain, grating, and functional limitation may be found on examination but the patient does not demonstrate the problems of instability of marked congenital abnormalities often seen with other patellar problems. Forty patients underwent a simple release of the lateral retinaculum to decompress the patella in the patellofemoral groove. Follow-up was obtained in 31 patients at an average of 18.3 months after surgery. Twenty-four knees which had severe preoperative pain were converted to 6 with no pain, 4 with mild pain, 11 with moderate pain and 3 whose pain remained unchanged after surgery. Twenty knees with moderate preoperative pain were changed to 4 with no pain, 11 with mild pain and 4 whose pain remained unchanged. Thirty-seven of the 45 knees had lessening of the pain after the operation and 10 patients returned to unrestricted atheletic activities.

Clinical test for anterolateral rotary instability of the knee.

A simplified test for anterolateral rotary subluxation of the knee is largely based on the concepts described by Galway and McIntosh although performed in a different manner. The examiner places the right hand gently on the lateral side of the knee with the thumb overlying the posterior aspect of the fibula and the index finger palpating the anterolateral aspect of the joint line to determine the the tibiofemoral relationship. The left hand embraces the lateral side of the distal end of the femur with the thumb over the posterior aspect of the lateral femoral condyle. With equal pressure on the lateral femoral condyle and fibular head the knee is pushed gently forward into flexion. When anterointernal tibial luxation is present, a reduction phenomenon is felt as the knee passes into the 25 to 40 degree flexion range. This may occur as a sudden palpable and occasionally audible repositioning which is responsible for such terminology as a "pivot shift" or "jerk sign." We have experienced many instances where the reduction phenomenon is more subtle and is determined by palpation alone. The pathologic mechanics are determined by observations at surgery in 45 patients with a positive test. This test has improved our diagnositc ability and is easly taught to those unfamiliar with knee joint disorders.

Immunological studies on the envelope component of Venezuelan equine encephalomyelitis virus.

Treatment of purified Venezuelan equine encephalomyelitis virus with the nonionic detergent Triton X-100 permitted spearation of the envelope from the core component. The isolated envelope was a noninfectious immunogen which reacted in hemagglutination, hemagglutination inhibition, complement fixation, and neutralization serological reactions.