Composite reflective/absorptive IR-blocking filters embedded in metamaterial antireflection-coated silicon

Infrared (IR)-blocking filters are crucial for controlling the radiative loading on cryogenic systems and for optimizing the sensitivity of bolometric detectors in the far-IR. We present a new IR filter approach based on a combination of patterned frequency-selective structures on silicon and a thin (25-75 μm thick) absorptive composite based on powdered reststrahlen absorbing materials. For a 300 K blackbody, this combination reflects ∼50% of the incoming light and blocks >99.8% of the total power with negligible thermal gradients and excellent low-frequency transmission. This allows a reduction in the IR thermal loading to negligible levels in a single cold filter. These composite filters are fabricated on silicon substrates, which provide excellent thermal transport laterally through the filter and ensure that the entire area of the absorptive filter stays near the bath temperature. A metamaterial antireflection coating cut into these substrates reduces in-band reflections to below 1%, and the in-band absorption of the powder mix is below 1% for signal bands below 750 GHz. This type of filter can be directly incorporated into silicon refractive optical elements.

Optical properties of Ar ions irradiated nanocrystalline ZrC and ZrN thin films

Thin nanocrystalline ZrC and ZrN films (<400 nm), grown on (100) Si substrates at a substrate temperature of 500 °C by the pulsed laser deposition (PLD) technique, were irradiated by 800 keV Ar ion irradiation with fluences from 1 × 10¹⁴ at/cm² up to 2 × 10¹⁵ at/cm². Optical reflectance data, acquired from as-deposited and irradiated films, in the range of 500 - 50000 cm^-1 (0.06 - 6 eV), was used to assess the effect of irradiation on the optical and electronic properties. Both in ZrC and ZrN films we observed that irradiation affects the optical properties of the films mostly at low frequencies, which is dominated by the free carriers response. In both materials, we found a significant reduction in the free carriers scattering rate, i.e. possible increase in mobility, at higher irradiation flux. This is consistent with our previous findings that irradiation affects the crystallite size and the micro-strain, but it does not induce major structural changes.

A broadband micro-machined far-infrared absorber

The experimental investigation of a broadband far-infrared meta-material absorber is described. The observed absorptance is >0.95 from 1 to 20 THz (300-15 μm) over a temperature range spanning 5-300 K. The meta-material, realized from an array of tapers ≈100 μm in length, is largely insensitive to the detailed geometry of these elements and is cryogenically compatible with silicon-based micro-machined technologies. The electromagnetic response is in general agreement with a physically motivated transmission line model.

Optimization of the skin multiple analyte profile bioanalytical method for determination of skin biomarkers from D-Squame tape samples

BACKGROUND/PURPOSE

This work was performed to optimize extraction conditions for D-Squame tape skin samples for use in the skin multiple analyte profile (SkinMAP) method, a Linco Research Corporation bead-based assay for skin analytes. The experiments were designed to help identify sources of variability during extraction that may be amenable to further control.

METHODS

Two experimental designs were used to study factors influencing the extraction of skin samples from D-Squame tapes. Visually healthy skin samples were obtained from both female and male adult volar forearms. Factors studied in two experiments included: four surfactant (SDS) levels (0.02-0.2%), two buffer types [Citrate-phosphate buffered saline at pH 5.5, phosphate-buffered saline (PBS) at pH 7.4], two buffer volumes (1.0, 1.5 mL), two propylene glycol (PG) levels (0.1%, 1.0%), two extraction temperatures (7-10 degrees C, 22-30+ degrees C), two extraction times (30, 60 min), and location in sonication bath (two vectors). The response biomarkers were cortisol, fibronectin, human serum albumin, involucrin, keratin-6 and keratins 1, 10. Skin sampling sites were also evaluated as sources of variation.

RESULTS

There was no single set of extraction conditions in our experiments that maximized recovery of all the biomarkers. SDS level had the most consistently significant (P<0.05) and directional effects on biomarker recoveries. In general, higher SDS resulted in higher recovery of all biomarkers. There was less consistency and fewer significant results for the other extraction factors.

CONCLUSIONS

These data enable us to better manage SkinMAP studies and interpret their results. The use of 1.5 mL PBS containing 0.2% SDS and 0.5% PG with 30 min sonication at low (near 4 degrees C) temperature is optimal for the quantitation of a range of SkinMAP analytes. In order to protect researchers from obtaining inflated false positive rates, it is crucial to design such studies and analyze the data using appropriate statistical methodology, especially for those studies involving only a small number of subjects.

Recovery from coronary artery bypass surgery: age-related outcomes

As people age, their incidence of coronary heart disease increases. The majority of persons undergoing invasive procedures such as coronary artery bypass surgery are 65 and older. Because of population trends related to aging, it is projected that there will be exponential increases in the numbers of people requiring treatment for this health problem in the future. Changes in health care reimbursement have significantly decreased hospital length of stay, resulting in many patients completing their recovery either in a rehabilitation facility or at home. Patients with multiple preoperative comorbidities are at risk for postoperative complications. Older patients usually have more health problems after coronary artery bypass surgery because they have more risk factors prior to the procedure. It is not known whether there are differences in outcomes between comparatively older and younger patients when they are matched by risk classification. Information on the recovery of patients at home will enable nurses to meet their care needs prior to surgery and after discharge from the hospital.

Cardiac surgery's calculated risk

Nurses can evaluate preoperative risk and place cardiac surgery patients in four risk categories to predict patients' postoperative clinical and nursing resource needs.

Students' decisions to select HIV services for clinical experiences

The ever-growing numbers of persons living with HIV/AIDS emphasizes the need for highly trained healthcare professionals to care for this population. Understanding why nursing and medical students would choose HIV services for clinical rotations, and the impact of those clinical experiences on their future professional practice, is key to recruiting healthcare providers to care for this population.

Risk classification, clinical outcomes, and the use of nursing resources for cardiac surgery patients

Several studies have used risk classification models to examine the effect of preoperative risk factors on operative morbidity and mortality. However, previous research has not linked risk classification models to factors such as frequency of postoperative complications, length of intensive care unit stay, mortality, and the use of nursing resources. This article reports on significant differences in clinical outcomes and hours of nursing care by risk classifications.

Decreasing diagnostic blood loss for patients in critical care units

Several studies have investigated the problem of diagnostic blood loss for patients in critical care units. This research analysis categorizes these studies according to common themes, evaluates their methodologies, and synthesizes the findings. The author recommends research-based strategies that nurses can use to reduce patients' blood loss and the risk of complications such as nosocomial anemia.

From silencing the self to action: experiences of women living with HIV/AIDS

Feminist literature has demonstrated that women often maintain behaviors that support silencing of their voices. The critical issue is whether the silencing experience is (a) a destructive process of burying feelings and needs, (b) a protective strategy to preserve personal and professional relationships which they value, (c) a coping mechanism to divorce themselves from an androcentric/ethnocentric health care culture, or all of these. The transition from silence to action may be a process of reacting to a threat to self (i.e., HIV/AIDS diagnosis) where gender normative behaviors become irrelevant and self-advocacy becomes paramount for survival. Alternatively, the transition may be a conscious process of gaining insight into past behaviors that have been learned and culturally supported and making purposeful changes. Data for this study were extracted for secondary analysis from data from a larger study on experiences and needs of persons living with HIV/AIDS. Data were obtained from transcripts from three focus groups (N = 14 women) and six individual interviews. Women ranged in age from 21 to 55; 9 were European American, 7 were African American, and 4 were Latina American. Data were content analyzed and organized using four categories proposed by Jack (1991): (a) externalized self-perception, (b) care as self-sacrifice, (c) silencing the self, and (d) the divided self. Data supported that women with HIV/AIDS reported all four categories of silencing behaviors, particularly early in the HIV trajectory. For some women, an HIV/AIDS diagnosis ignited them to speak for themselves and to shape their own lives based on feelings and needs. For others, peer or professional support or both was the catalyst for the transition from silence to action. Findings suggest interventions that would assist women in judging themselves by internal versus external standards, putting their own needs before the perceived needs of others, expressing themselves toward action rather than avoidance, and feeling comfortable expressing anger.

Impact of risk classification on nursing resource utilization, postoperative length of stay, and hospital costs for cardiac surgical patients

Outcomes after cardiac surgery are a concern for patients, health care providers, and insurers. Because of the current economic climate, there is a demand for positive outcomes and an evaluation of negative results. The results of this study showed significant differences in nursing resource utilization, postoperative length of stay, and hospital costs by risk classification group. Risk classification models could serve as a template for staffing patterns and reimbursement based on patients' clinical profiles.

Factors influencing selected lengths of ICU stay for coronary artery bypass patients

This study examines factors influencing the length of intensive care unit stay for patients after coronary artery bypass surgery. Profiles of patients with selected lengths of ICU stay were identified for Group 1 (< or =1 day) and Group 2 (> or =2 days). Medical records of 175 patients who had undergone this procedure at an urban teaching hospital were reviewed. Patients who had a 1-day ICU length of stay were younger (mean=62.39, SD=10.88) and had comorbidities such as hypertension. Those patients with an ICU length of stay 2 days or longer were older (mean=68.18, SD=11.84) and had preoperative comorbidities such as congestive heart failure, chronic obstructive pulmonary disease, ejection fraction <50%, and need for an intra-aortic balloon pump. Atrial dysrhythmias, low cardiac output syndrome, renal insufficiency, and respiratory insufficiency were the postoperative complications associated with a prolonged ICU length of stay. Knowledge of the factors influencing selected lengths of ICU stay will enable nurses to choose patients for critical pathways and to anticipate postoperative problems in high-risk patients.

Diminution of T cells with gamma delta receptor in the peripheral blood of allergic asthmatic individuals

BACKGROUND

T cells are shown to regulate allergy and asthma. They are heterogeneous by virtue of surface receptor subtypes (alpha beta and gamma delta receptors), however, their pathophysiological roles in asthma are unclear.

OBJECTIVE AND METHODS

The present study employed flow cytometric analysis to compare the size of T-cell subsets and eosinophils present in the peripheral blood of healthy, allergic and allergic asthmatic individuals.

RESULTS

Current results demonstrated that the percentages of gamma delta T cells declined from 4.1% in healthy to 3.2% in the allergic subjects and to a significantly lower (P = 0.01) 2.4% in allergic asthmatics. The absolute numbers of circulating gamma delta T cells also were diminished in a similar fashion such that healthy individuals had a significantly higher mean cell count (91.8 x 10(3)/mL) than did allergic asthmatics (47.8 x 10(3)/mL) (P = 0.0266). In contrast, alpha beta T cells were comparable in the healthy, allergic, and allergic asthmatic populations (65.3%, 65.8% and 69.4%, respectively); the differences were not statistically significant. On a populational basis, the proportion of individuals having both gamma delta T cells < or = 4.1% and eosinophils > or = 2.1% was the lowest in the healthy population (30.8%), but was elevated in the allergic group (85.7%) as well as in the allergic asthmatic group (86.6%). However, on an individual basis, those who had reduced gamma delta T cells did not have consistently higher eosinophil counts or IgE level.

CONCLUSION

It was concluded that no significant correlation existed between the levels between gamma delta T cells and eosinophils or between gamma delta T cells and IgE present in the peripheral blood. This report, for the first time, documents that allergic asthmatics have reduced gamma delta T cells with reciprocally elevated eosinophil numbers in their peripheral circulation. However, it does not indicate that the reduction of gamma delta T cells directly correlates with the predominance of eosinophils of IgE levels in the diseased populations. The pathophysiological role of gamma delta T cells in allergic diseases awaits further exploration.

A Strategy for Responding to the Training Needs of Nursing Staff in a New Cardiac/Neurosurgical ICU and Telemetry Unit

The decision of the Brigham and Women's Hospital (BWH) to expand its capacity to care for acute cardiac surgical and neurosurgical patients resulted in the need for an education and training program for a large group of nursing staff. In such situations, where an existing service is being expanded or a new service initiated, nursing education departments must quickly devise simple and cost-effective mechanisms to promote the competency of nursing staff. Nurse educators, staff nurses, nurse managers, and clinical nurse specialists all play a role in planning and implementing the relevant education and evaluation program. BWH chose to recruit temporary special projects staff nurses to address these increased educational needs.

Electrical stimulation for dermal wound healing

The investigations of biologic actions (in vitro, animal, and human) demonstrated several effects that help explain why electrical stimulation works. Based on the latest scientific understanding of the wound healing process, one would expect that a therapy that decreases edema, debrides necrotic tissue, attracts neutrophils and macrophages, stimulates receptor sites for growth factors, stimulates growth of fibroblasts and granulation tissue, increases blood flow, stimulates neurite growth, induces epidermal cell migration, prevents postischemic oxygen radical-mediated damage, inhibits bacteria, and reduces numbers of mast cells ought to be beneficial for wound healing. Numerous human and animal efficacy studies confirm that electrical stimulation of the proper charge, density, and total energy causes dramatically improved healing of dermal wounds. As of this writing, no devices have yet been approved by the FDA for use in wound healing, although several devices approved for other indications are being used for this purpose. One device (the Staodyn Dermapulse) has undergone controlled animal and human testing, and an application requesting approval for treating dermal ulcers has been submitted to FDA. Taken together, the efficacy studies and the "mechanism of action" studies provide compelling, scientific evidence that electrical stimulation is safe and effective for promoting the healing of dermal wounds.

Immunoprotein deposition in the cornea

A 63-year old woman had bilateral, multi-level corneal deposits distributed as fine, discrete crystals and in dense, deep geographic patches. She had a long history of sero-positive rheumatoid arthritis. Autopsy revealed an unsuspected lymphoproliferative disorder and immune-complex disease. Histologic examination of the eyes revealed eosinophilic, PAS-positive, noncollagenous deposits in the cornea at all levels and also in the ciliary processes, pars plana, and choroid. Stains for gold, amyloid, and acid mucopolysaccharides were negative. Immunoperoxidase stains were positive for IgG most strongly, and also for IgA, kappa and lambda light chains. Transmission electron microscopy showed needle-like electron-dense extracellular particles which we presume are immunoglobulins.

Sexual adjustment after lower extremity amputation

Sexual adjustment following lower extremity amputation was evaluated by interviewing 60 adults with recent amputations, 39 men and 21 women, after they had become independent in ambulation with a prosthesis. Among the men, 77% reported a substantial decrease in the frequency of sexual intercourse following amputation, while only 38% of the women reported a decrease. The decreased frequency was greater for nonmarried men than for married men, greater for men with above-knee amputations than for men with below-knee amputations, and greater for male amputee patients in whom phantom phenomena persisted compared to those in whom phantom phenomena no longer existed. The decreased frequency of intercourse for male amputee patients was unrelated to the patient's age, education, and etiology of amputation. There was no significant change in other aspects of sexual activity, including oral-genital relations, masturbation, homosexuality, and extramarital relations.

Voice terminal may offer opportunities for employment to the disabled

A rapidly growing information industry based on the combined technologies of the digital computer and telecommunications offers unique opportunities for employment of the physically handicapped. In the studies reported here, the use of voice control was investigated as an alternative to mechanical control for two quadriplegic clients too severely disabled to successfully operate a typewriter keyboard. Using a recently developed voice terminal, the clients were able to type finished copy and program a remotely located computer entirely by voice control. The voice terminal is presently in production. An evaluation of the vocational potential of the voice terminal is currently being conducted by the Rehabilitation Services Administration, DHEW.