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Background:Hallux limitus (HL) is a pathology of degenerative arthritis in the first metatarsophalangeal joint (MTJ) of the great toe. Chief complaints of HL include inflammation, edema, pain, and reduced flexibility. The onset of HL commonly occurs after one of the two most common surgical procedures for foot pathologies, a bunionectomy or a cheilectomy. The purpose of this study is to determine the efficacy of dynamic splinting in treating patients with postoperative hallux limitus, in a randomized, controlled trial.Methods:Fifty patients (ages 29 to 69) were enrolled after diagnosis of HL following surgery. The duration of this study was eight weeks, and all patients received nonsteroidal anti-inflammatory drugs, orthotics, and instructions for a home exercise program. Experimental patients were also treated with dynamic splinting for first MTJ extension (60 minutes, three times per day). The dependent variable was change in active range of motion (AROM). A repeated measures analysis of variance was used with independent variables of patient categories, surgical procedure (cheilectomy vs. bunionectomy) and duration since surgery.Results:There was a significant difference in change of AROM for experimental vs. control patients (P < 0.001, T = 4.224, N = 48); there was also a significant difference for patient treated within 2 months of surgery (P = 0.0221).Conclusions:Dynamic splinting was effective in reducing contracture of postoperative hallux limitus in this study; experimental patients gained a mean 250% improvement in AROM. This modality should be considered for standard of care in treating postoperative hallux limitus. (J Am Podiatr Med Assoc 101(4): 285–288, 2011)

The surface of Y2O3-stabilized ZrO2 (YSZ) is implanted with Cu and Mn in order to turn it into a mixed ionic electronic conductor (MIEC). Ar is implanted in order to examine the effect of damage only on the electrical properties. Mixed conductivity appears in the Cu- and Mn-implanted layers and is high enough to short-circuit the much thicker non-implanted YSZ layer, at T A relatively fast exchange of oxygen with YSZ is observed at temperatures as low as 215 °C through the implanted layer, where equilibrium is obtained, upon annealing, within ∼60 min.

Three radiation detectors based on polycrystalline diamond films with different thickness and resistivity, obtained by microwave chemical vapor deposition, were tested to assess their suitability for relative dosimetry of photon and electron beams supplied by clinical linear accelerators. All samples showed a linear response as a function of the absorbed dose. The sensitivity per unit of detector sensitive volume spanned between 7 and 43 nC Gy−1 mm−3 with an applied electric field of 40 kV/cm. The dose rate dependence was evaluated following the Fowler theory and D coefficient values between 0.95 and 1.00 were found for the three samples when polarized at 40 kV/cm. Percentage depth dose curves, output factors, and normalized dose profiles were determined for 6 and 10 MV photon beams and for 6 and 15 MeV electron beams. The results obtained with the diamond detectors were in good agreement with those obtained by reference detector measurements fall the data were within the experimental uncertainty of 1% s1sdg.

The authors review the ankle and pantalar fusion literature. The authors performed a retrospective review on 42 ankle and pantalar fusions, emphasizing the role of internal fixation. The Podiatry Institute technique for internal fixation of ankle fusions is described and experience with the technique is reviewed. Complications included delayed union and nonunion at the fusion site or the repaired fibular osteotomy site and tibial fractures at screw stress riser sites. Modifications to reduce these complications are discussed. Experience with internal fixation in ankle and pantalar fusions, both in this study and in current literature, has been positive.

Although the most prominent social psychological models of health behavior are expectancy based, little attention has been paid to the role of individuals' beliefs about physicians in the utilization and evaluation of health care. Three studies suggest that individuals' beliefs about whether physicians should adopt an authoritarian or egalitarian role in health care interactions are related to health care utilization, satisfaction, and compliance. In Study 1, we found that authoritarian role expectations were associated with more self-reported visits to medical professionals in a sample of college undergraduates. In Study 2, we examined a sample of elderly outpatients and found that authoritarian beliefs were associated with objective indicators of greater health care utilization. In Study 3, we had undergraduates with authoritarian or egalitarian role expectations read a vignette in which a physician displayed either an authoritarian or egalitarian communication style. Although all subjects reported grea...

The combined electrical and structural characterization of encapsulated HgCdTe annealed in a rapid thermal processor under different temperatures and times is presented. Hall effect measurements are used for the determination of the changes in carrier concentration and mobility produced during the annealing, while structural changes due to the thermal treatment are deduced from channelled proton-induced X-ray emission measurements. The results indicate that both the carrier concentration and mobility change homogeneously throughout the crystal, reaching equilibrium values that are only a function of the annealing temperature. The evolution towards equilibrium of each parameter can be fitted to exponential laws, the time constants being a function of the annealing temperature. However, the time required to reach the equilibrium mobility is always longer (by about ×3.5) than that needed to saturate the carrier concentration, for the same temperature. The crystallinity of the samples also shows a dependence on the annealing temperature. These changes are explained on the basis of generation and annihilation of mercury vacancies through the interaction with tellurium precipitates.

With medical training focused on medical knowledge and skills, the nurturing of humanistic care can suffer.We designed and conducted an outpatient rheumatology patient-partner exercise that integrates the assessment of student compassionate care into an outpatient clinical skills training exercise.Eleven third-year medical students were videotaped performing a medical history on a patient volunteer. Students, the preceptor and a fourth-year medical student independently observed the videotape, tagged segments demonstrating observed or missed compassionate care opportunities and completed a compassionate care questionnaire. Students also participated in a focus group. Ten patients completed a comparable questionnaire and provided feedback on student encounters.Students recognized and reflected on opportunities for compassionate care. The preceptor's feedback was reinforced. Students' ratings of their demonstrations of compassionate care were lower after reviewing videotapes, and were also lower than preceptor ratings. Patients were satisfied with the exercise and highlighted student professionalism.The exercise proved to be an effective format for promoting student reflection on and self-assessment of compassionate care. It demonstrated that nurturing compassionate care can be integrated into an outpatient clinical skills exercise.

The effects of ion-implantation on both polysiloxane and silicate spin-on-glass thin films were studied and are reported here. The authors have shown, using various analysis techniques, that the damage induced by the implantation drastically modified the film properties. A pronounced volume shrinkage was observed in polysiloxane films after the implantation and a respective increase in the effective refractive index of the oxide layer was measured. An infrared transmission study of the samples suggests that the ion-implanted samples have fewer carbon-based components and less hydrogen than the unimplanted samples. Similar measurements using silicate-type spin-on-glass films have shown only a slight variation of the thickness, the refractive index, and the infrared transmission spectrum. Both material types change their etching characteristics in wet reagents after ion-implantation. The etch rate in HF solutions of the spin-on SiO[sub 2] materials was lowered after the implant, and occasionally an inhibition period before any etching could be observed. Metal-isolator-silicon (MIS) capacitors with spin-on oxide additionally were tested before and after the implantation and the results are reported and discussed here. Stress characterization indicates that a lower overall internal stress exists in the ion-implanted films compared to the as-deposited layers. Based on the results presented, the authors concludemore » that the ion-implantation densifies the spin-on SiO[sub 2] film and reduces the carbon content in the layer. They suggest that these material modifications are related to the radiation damage induced by the implantation and to a reordering state of the atomic structure during the implantation process.« less

Resonant Raman scattering by longitudinal optical phonons has been used to study the effect of annealing in a hot Hg bath on 113In+ and 11B+ implanted Cd0.23Hg0.77Te. Up to the highest doses of 1×1013 cm−2 for In and 1×1014 cm−2 for B, respectively, Raman spectroscopy indicates a full recovery of the crystalline perfection for annealing temperatures around 320 °C and annealing times ≥10 min. This recovery is accompanied by an electrical activation of the implants. Control experiments have been carried out to prove that the electrical activity is not due to residual lattice damage and that the immersion in the Hg bath by itself has no effect on the Raman spectrum.

Ion-beam induced intermixing of quantum wells and superlattices is of use in the fabrication of low dimensional structures by spatially restricted ion implantation. The ultimate size of quantum lines or dots is determined by the spatial extent of the intermixing due to individual ion impacts and subsequent annealing. We show by photoluminescence measurements that complete intermixing of implanted and annealed GaAs/GaAlAs interfaces takes place at a very low dose (≈ 10 11 cm −2 ). This enables us to deduce intermixing radii, following annealing, of 20–30 nm for the affected area due to individual ion impacts. These radii are about one order of magnitude larger than the damage track prior to annealing. The exceptionally large radii found in the present work are attributed to defect assisted interdiffusion. The low doses for mixing also support the particle channeling explanation for ion induced mixing at depths in excess of the amorphous range.

The buildup of damage caused by In ion implantation (320 keV, 1012–1015 cm−2) in Hg1−xCdxTe (x=0.24) (MCT) and Hg1−xZnxTe (x=0.16) (MZT) is studied by means of Rutherford backscattering spectroscopy (RBS) channeling along the

The vibrational amplitudes of constituents atoms in Zn x Cd 1− x Te and Hg 1− x Cd x Te are deduced from combined proton-induced X-ray emission and Rutherford backscattering channeling measurements at various compositions and temperatures. For Zn x Cd 1− x Te the addition of small quantities of Zn ( x ≃ 0.1) to CdTe is found to produce a drastic (40%) decrease in the vibrational amplitudes, the Te atoms being more affected than the Cd. In Hg 1− x Cd x Te the Hg atoms are found to vibrate with amplitudes larger than the rest of the atoms for all compositions studied, while a minimum in the amplitudes is reached at x = 0.7 for all constituent atoms. Temperature dependent measurements reveal basic differences in the dynamical behavior of the CdTe based ternaries as compared to pure CdTe. Possible explanations for the above results are presented.

Annealing of Hg 1− x Cd x Te ( x = 0.21) by immersion in a hot Hg bath has been investigated with regard to the electrical properties of as-grown and ion implanted samples. The method was found to be comparable to other more complicated annealing techniques as for improving the electrical properties of HgCdTe deduced from Hall and differential Hall effect measurements. As-recrystallized p-type samples can be converted to good n-type following immersion for 50 h in the Hg bath at 260°C. This annealing, when performed at 250°C for just a few minutes, improves the mobility of undoped n-type samples up to 50%. Electrical activation of B implants in Hg 0.79 Cd 0.21 Te can be achieved following immersion for 8 min in the Hg at 320°C.

Layers of Ga0.25In0.75P were grown on InP by metalorganic molecular beam epitaxy and studied by ion channeling and asymmetric high-resolution x-ray diffraction. The angular difference between the substrate and the layer channeling angles agreed with the corresponding angular difference calculated from the x-ray results. Negligible relaxation was found in Ga0.25In0.75P layers up to a thickness of 50 nm. Thicker layers were found to be partially relaxed. In the channeling experiments an additional minimum in the substrate angular scan profile at an angle corresponding roughly to the layer’s minimum yield was found. This extra minimum was attributed to the steering effect at the strained GaInP/InP interface [S. Hashimoto, Y. Q. Feng, W M. Gibson, L. J. Schowalter, and B. D. Hunt, Nucl. Instrum. Methods B 13, 45 (1986)], and was confirmed by a comparison with the x-ray diffraction measurements.

Three radiation detectors based on polycrystalline diamond films with different thickness and resistivity, obtained by microwave chemical vapor deposition, were tested to assess their suitability for relative dosimetry of photon and electron beams supplied by clinical linear accelerators. All samples showed a linear response as a function of the absorbed dose. The sensitivity per unit of detector sensitive volume spanned between 7 and 43 nC Gy(-1) mm(-3) with an applied electric field of 40 kV/cm. The dose rate dependence was evaluated following the Fowler theory and delta coefficient values between 0.95 and 1.00 were found for the three samples when polarized at 40 kV/cm. Percentage depth dose curves, output factors, and normalized dose profiles were determined for 6 and 10 MV photon beams and for 6 and 15 MeV electron beams. The results obtained with the diamond detectors were in good agreement with those obtained by reference detector measurements [all the data were within the experimental uncertainty of 1% (1sigma)].

Publisher Summary This chapter discusses the doping diamond by ion-implantation. Ion-implantation has proven to be a most important technique for doping semiconductors toward the realization of electronic devices. Without ion-implantation, the advancement in the miniaturization of devices, mainly in Si, would be impossible. For the case of diamond, even though its use as a material for electron devices is promising because of the unique physical and chemical properties, its application in practical devices is still rather scarce. Among the difficulties encountered are problems related to doping diamond under well-defined spatial restrictions and to well controllable doping levels, for which ion-implantation doping is particularly suitable. Unfortunately, because of the very special properties of diamond (tight crystal, metastability of the sp3 vs. the sp2 bonding, high annealing temperatures, wide band gap) doping diamond by ion-implantation and correctly assessing the results is particularly complicated. The need to find a way of obtaining n-type conductivity in diamond by identifying a suitable dopant with a shallow enough donor level, and devising methods of incorporating it into the diamond crystal are still unsolved. Ion-implantation may offer unconventional ways of solving the above problem. In order to achieve this goal, theoretical predictions and guidance by computational methods are required.

Selective implantation of 140 keV Co ions into self-supporting diamond films converts the surface into a conductive region at which redox electron transfer and metal deposition have been accomplished. Simple masking allows precise definition of the area to be plated within the insulating diamond matrix. Formation and electrochemical characterization of a rotating disk electrode in this manner are demonstrated.

The intermixing of GaAs/AlGaAs quantum wells due to the passage of single energetic heavy ions (8 MeV Bi) is deduced from photoluminescence measurements after rapid thermal annealing (900 °C, 4 min). It is found that while the structural damage radius around an ion track due to pure kinematic mixing is very small (1.0–3.0 nm), thermal annealing increases this mixing radius by more than an order of magnitude (to ∼20 nm). This finding has important implications for ion‐beam definition of quantum dots or wires in quantum well structures. Our results also clarify the proposed explanation of particle channeling as the cause of ion induced mixing far in excess of the amorphous range.

Background Bullous pemphigoid (BP) and pemphigus vulgaris (PV) are autoimmune bullous skin diseases mediated by autoantibodies against adhesion molecules of the skin. Previous studies have identified autoreactive T cells in patients with BP and PV, which may be critical in providing B-cell help for autoantibody production. Objectives To evaluate the frequency of autoreactive T-helper (Th) 1 and Th2 cells in patients with BP (n = 7) or PV (n = 1) and in healthy controls (n = 11). Methods In an enzyme-linked immunospot (ELISPOT) assay, microtitre plates were coated with antihuman interleukin (IL)-5 IgG or antihuman interferon (IFN)-γ IgG prior to culturing human peripheral blood lymphocytes (PBL) with BP180 or desmoglein (Dsg) 3 proteins for 7 days. Cytokine-producing autoreactive T cells were visualized as spot-forming units. Results One BP patient with extensive blisters had 5·1 ± 1·5 (mean ± SD) BP180-reactive Th1 cells and 2·9 ± 1·5 Th2 cells per 105 PBL. In contrast, PBL from six BP patients in remission or on immunosuppressive therapy did not form IFN-γ- or IL-5-producing spots per ≤ 5 × 105 PBL. The patient with oral PV had 4·7 ± 2·4 Th1 cells and 3·0 ± 0·4 Th2 cells per 105 PBL and a vigorous PBL response to Dsg3. In addition, three of 10 controls had BP180-reactive Th1 (2·7–13·8 per 105 PBL) and Th2 (0·3–1·8 per 105 PBL) cells and one control had 9·0 ± 0·7 Th1 cells and 1·1 ± 0·8 Th2 cells per 105 PBL, with reactivity to Dsg3. ELISPOT reactivity correlated with 3H-thymidine incorporation in six of seven patients and controls with autoreactive T-cell responses. Conclusions The ELISPOT assay seems to be promising for the quantitative and qualitative analysis of autoreactive T-cell responses in BP and PV.

Very high sensitivity to low dose implantation damage has been achieved by a novel quantitative analysis of electron channeling patterns (ECPs). An algorithm, based on the statistical analysis of the two‐dimensional ECP pictures obtained from a scanning electron microscope, has been developed. The analysis yields a single number (the variance), analogous to the quantity χmin deduced from ion channeling measurements, which characterizes the surface crystallinity. Measurements performed on implanted silicon (point defects) and CdTe (extended defects) crystals show that electron channeling is approximately two orders of magnitude more sensitive to implantation damage than ion channeling. Changes in the ECP of Si and CdTe were observed after implantations with 200 keV Ar and 320 keV In ions at doses as low as 1×1012 cm−2 and 1×1013 cm−2, respectively. Moreover, electron channeling is capable of probing areas about four orders of magnitude smaller than commonly used ion channeling.

The transition from point defects, frozen‐in at low‐temperature ion implanted Hg1−xCdxTe (x=0.24), to extended defects has been monitored through ion channeling experiments in the temperature range 100–360 K. It is found that the transition exhibits time and temperature dependencies characteristic for diffusion processes with exceptionally low parameters. The extended defects formed by the agglomeration of frozen‐in point defects are found to roughly correspond in depth to the implant range, in contrast to defects directly created by room‐temperature implantation which extend much deeper into the crystal.

Screening pretransplantation recipient sera for percent panel reactive antibodies (%PRA) by an anti-human globulin (AHG) assay may identify recipients who are at risk for graft rejection or development of posttransplantation coronary artery disease. However, the pretransplantation AHG-%PRA does not always correlate with the occurrence of graft rejection or coronary artery disease.We compared the predictive capacity of the AHG-%PRA with that of an enzyme-linked immunoassay (EIA)-based PRA assay that identifies immunoglobulin G bound to soluble human leukocyte antigen (sHLA) class I molecules from pooled platelets of 240 random donors (sHLA-EIA), and that of an EIA-based assay that detects immunoglobulin G anti-HLA class I antibodies bound to sHLA derived from individual HLA-typed cell cultures (PRA-STAT). The pretransplantation sera from 130 cardiac allograft recipients were comparatively tested and results evaluated.Although AHG-%PRA- and sHLA-EIA-determined PRA results were comparable, neither assay discriminated potential recipients at risk for rejection or coronary artery disease. However, cardiac allograft recipients with pretransplantation PRA-STAT sera10% were at risk for (1) graft rejection (77% vs 56%, p.05); (2) more rejections/recipient (1.9 vs 1.0, p.02); (3) graft rejection within 30 days (92% vs 38%, p.001); or (4) development of coronary artery disease (48% vs 23%, p.05) than recipients with pretransplantation PRA-STAT sera10%.PRA-STAT analysis of pretransplantation sera from potential cardiac allograft recipients may be more clinically informative about HLA alloimmunity and a better predictor of adverse clinical events than either AHG-%PRA- or sHLA-EIA-determined PRA.

Publisher Summary This chapter deals with ion-implanted quantum-well structures. In particular, the physical issues resulting from interdiffusion between the layers, intermixing phenomena, and channelling and disordering effects in heterostructures are addressed. The major growth area within semiconductor physics has been the study of layered structures, grown by molecular beam epitaxy (MBE), metal-organic chemical vapor deposition (MOCVD), or chemical beam epitaxy (CBE). These structures consist of semiconductor layers withthe interface geometry, doping level, and chemical composition defined with atomic-scale precision. Superlattices (SLs) and multiple quantum wells (QWs) are artificially structured materials made by interleaving layers of semiconductors with different electronic properties. In this way it is possible to control the electronic properties of the SL and QW by redesigning matter on a quantum mechanical scale. Furthermore, it has extremely important device applications in that it allows the design of semiconductors that do not exist in nature. In particular, it gives control over important material parameters such as the band gap (through confinement effects), the carrier concentration, the carrier mobility, and the carrier lifetime.

The clinical features of Lyme disease have been well documented since its description as a distinct clinical entity in 1975. A better understanding of the diversity of Borrelia strains and species that cause the disease as well as new insights into the immunology and pathogenesis of Lyme disease help explain some of the observed variations in clinical manifestations. The diagnosis of Lyme disease may be straightforward when patients in endemic areas present with typical clinical features; however, the diagnosis should be in doubt when the clinical picture is nonspecific or atypical, or a feasible exposure history cannot be obtained. Laboratory diagnosis is primarily based on serologic techniques, but interpretation of test results can be fraught with uncertainty. Treatment with appropriate antibiotics is successful in the majority of cases of Lyme disease. However, some patients may not respond, and in these cases multiple repeated courses are usually ineffective and unwarranted. More data are needed to determine the appropriate treatment of Lyme disease during pregnancy, and the appropriate management of ixodes tick bites. A suitable arthropod vector and a competent animal reservoir host are essential for perpetuating Lyme disease in a geographic location. The intricate ecologic forces at work are well understood in certain endemic areas but are poorly defined elsewhere, particularly where the disease is sporadic or its existence is in question. Prevention of Lyme disease is best achieved through education regarding avoidance of the tick vector. A vaccine using a recombinant form of the OspA protein of B. burgdorferi has been successful in animal models. Whether an effective human vaccine can be developed remains unknown.

In this and the following chapter, a review of implantation-induced modifications of the structure and properties of graphite (Sect. 6.1–Sect. 6.8) and graphite-related materials (Chap. 7) is presented. Chapters 8 and 9 present a similar review of ion-implantation studies in diamond and diamond-related materials. Due to the variety of bonding characteristics, crystalline structures and thermodynamic properties, the family of carbon-based materials exhibits a rich variety of implantation-related phenomena. The effects of implantation-induced damage, the subsequent annealing of this damage in these materials, and the incorporation of the implanted species in the host lattice are all discussed in the following sections. Particular attention is given to the disparities and commonalities in the behavior of these materials upon implantation, demonstrating the uniqueness of carbon as a host material for ion implantation.

Perturbed Angular Correlation (PAC) and Hall measurements were used to investigate the stability of the passivating Cd-H complex in GaAs after low energy H implantation (150 eV, 1014 cm−2) at 300 K. From the observed Cd-H pair formation and reduction of hole concentration it is deduced that about 10 % of the implanted H atoms form pairs with the Cd atoms. The influence of the dopant depth profile on the apparent stability in zero bias isochronal annealing experiments is reported. After H loading a reduction of carrier mobility is observed, which is stable up to about 400 K. The formation of Cd-H pairs after low energy H implantation into InP was studied by PAC. By measuring the fraction of pairs in an isochronal annealing experiment, the stability of the pairs is deduced yielding a dissociation energy of ED = 1.8 (1) eV.

Carbon materials are unique in many ways. One distinction relates to the various allotropic forms these materials can assume. Under ambient conditions, the graphite phase with strong in-plane trigonal bonding is the stable phase, as indicated by the phase diagram of Fig. 2.1 [2.1, 2]. Under the application of high pressure and high temperature (which are somewhat reduced when catalyst particles like iron or nickel are used), transformation to the diamond structure takes place. Once the pressure is released, diamond remains essentially stable under ambient conditions although, in principle, it will very slowly transform to the thermodynamical stable form of solid carbon which is graphite. However, when exposed to various perturbations, diamond will transform back to the equilibrium graphite phase. In this phase, the structure is highly anisotropic, exhibiting, for example, metallic behavior in the basal(ab) plane and poor electrical conductivity along the c-axis [2.3]. In contrast, diamond is an isotropic cubic wide gap semiconductor [2.4]. In terms of mechanical properties, graphite is the stiffest material in nature (has the highest in-plane elastic modulus), while diamond is the hardest (least deformable) material. Of all materials, diamond along with graphite (in-plane) exhibit the highest thermal conductivity and the highest melting point [2.5]. Diamond also has the highest atomic density of any solid (Table 2.1).

Although ion beam techniques provide the most powerful methods for characterizing ion-implanted carbon-based materials, a number of other techniques have also yielded important characterization information. In this chapter we briefly review the most important of these techniques, indicating how they are used specifically for the characterization of graphite, diamond and related materials.

Two families of man-made materials which are closely related to diamond have been developed recently, and the ion-induced effects relevant to these are mentioned here. The first, which was already grown ~20 years ago [9.1], are amorphous-hydrogenated carbon (a—C:H) (or, as sometimes called, diamondlike carbon, DLC) films and the second are the recently-developed man-made thin diamond films. Both of these are grown in the form of thin coatings from a plasma which contains a mixture of carbon and hydrogen ions. In the following, ion implantation studies in DLC are briefly reviewed. As for implantation effects in diamond films, hardly any data exist on these, probably because of the novelty of the material. However, from the available data [9.2] it seems that diamond films respond to ion implantation exactly like diamond single crystals do, at least as reflected in ion-induced changes in the electrical conductivity and in the Raman spectra.

A variety of experimental techniques have been used to characterize the implantation-induced modifications to the target material, as well as the associated lattice damage. In this chapter, some background is provided on the most important characterization techniques based on ion beam analysis (IBA).

The effects that energy deposition by ions, electrons and photons have on the structure and properties of Diamond-Like Carbon (amorphous hydrogenated carbon) films are reviewed. In all cases the treated films turn electrically conductive and optically opaque; nevertheless it is shown that different physical processes are responsible for the observed changes for the different modes of energy deposition. Results obtained by a variety of experimental techniques which probe the structural and compositional changes are described. Models which fit the experimental data on hydrogen loss and on changes in electrical and optical properties as a result of ion irradiation are proposed.

The proposed purchase of Chicago's Michael Reese Hospital and Medical Center by Humana Inc., is hailed as one of the first such takeovers driven by the value of an HMO plan rather than the value of the parent hospital. The author discusses the proposed $50 to $70 million Reese purchase and its impact on the market.

Diabetic lower extremity infections, frequently polymicrobial, are at times fascinating though frustrating for the practitioner to treat. The classical triad of neuropathy, infection, and angiopathy is the hallmark of diabetic foot pathology. One of the main forms demonstrating the severe long-term neuropathic disease is called osteoarthropathy or Charcot joint. This is usually relatively painless, always progressive, and frequently destructive. It generally attacks the midtarsal joint and eventually changes the entire architecture of the foot, causing the so-called "rocker bottom" foot type. We present a case of a severely destructive Charcot foot that caused a large synovial cyst because of its vast underlying osseous pathology. The morbidity and mortality of these infections can be minimized by understanding the unique challenges these individuals offer the practitioner.