Broadband, millimeter-wave antireflection coatings for large-format, cryogenic aluminum oxide optics.

We present two prescriptions for broadband ($ {\sim} 77 - 252\;{\rm GHz} $), millimeter-wave antireflection coatings for cryogenic, sintered polycrystalline aluminum oxide optics: one for large-format (700 mm diameter) planar and plano-convex elements, the other for densely packed arrays of quasi-optical elements-in our case, 5 mm diameter half-spheres (called "lenslets"). The coatings comprise three layers of commercially available, polytetrafluoroethylene-based, dielectric sheet material. The lenslet coating is molded to fit the 150 mm diameter arrays directly, while the large-diameter lenses are coated using a tiled approach. We review the fabrication processes for both prescriptions, then discuss laboratory measurements of their transmittance and reflectance. In addition, we present the inferred refractive indices and loss tangents for the coating materials and the aluminum oxide substrate. We find that at 150 GHz and 300 K the large-format coating sample achieves $ (97 \pm 2)\% $ transmittance, and the lenslet coating sample achieves $ (94 \pm 3)\% $ transmittance.

kT-Scale interactions between supported lipid bilayers.

We use total internal reflection microscopy (TIRM) and confocal laser scanning microscopy (CSLM) to study supported lipid bilayer (SLB)-modified silica colloids with various SLB compositions (e.g., PEGylated vs. non-PEGylated) that control colloidal and bilayer stability. Measured and predicted potentials accurately capture stable configurations. For unstable conditions when SLBs adhere, fuse, or spread between surfaces, SLB structures are connected to effective potentials as well as time-dependent behavior. In all cases, directly measured and inferred interactions are well described by steric interactions between PEG brushes and van der Waals weakened by substrate roughness. Our findings quantify non-specific kT-scale interactions between SLB-modified colloids and surfaces, which enables the design of such systems for use in biomedical applications and studies of biomolecular interactions.

Noise performance of phase-insensitive multicasting in multi-stage parametric mixers.

Noise properties of large-count spectral multicasting in a phase-insensitive parametric mixer were investigated. Scalable multicasting was achieved using two-tone continuous-wave seeded mixers capable of generating more than 20 frequency non-degenerate copies. The mixer was constructed using a multistage architecture to simultaneously manage high Figure-of-Merit frequency generation and suppress noise generation. The performance was characterized by measuring the conversion efficiency and noise figure of all signal copies. Minimum noise figure of 8.09dB was measured. Experimental findings confirm that noise of the multicasted signal does not grow linearly with copy count and that it can be suppressed below this limit.

Detection of B-mode polarization in the cosmic microwave background with data from the South Pole Telescope.

Gravitational lensing of the cosmic microwave background generates a curl pattern in the observed polarization. This "B-mode" signal provides a measure of the projected mass distribution over the entire observable Universe and also acts as a contaminant for the measurement of primordial gravity-wave signals. In this Letter we present the first detection of gravitational lensing B modes, using first-season data from the polarization-sensitive receiver on the South Pole Telescope (SPTpol). We construct a template for the lensing B-mode signal by combining E-mode polarization measured by SPTpol with estimates of the lensing potential from a Herschel-SPIRE map of the cosmic infrared background. We compare this template to the B modes measured directly by SPTpol, finding a nonzero correlation at 7.7σ significance. The correlation has an amplitude and scale dependence consistent with theoretical expectations, is robust with respect to analysis choices, and constitutes the first measurement of a powerful cosmological observable.

Connecting Adaptive Perceptual Learning and Signal Detection Theory in Skin Cancer Screening.

Combining perceptual learning techniques with adaptive learning algorithms has been shown to accelerate the development of expertise in medical and STEM learning domains (Kellman & Massey, 2013; Kellman, Jacoby, Massey & Krasne, 2022). Virtually all adaptive learning systems have relied on simple accuracy data that does not take into account response bias, a problem that may be especially consequential in multi-category perceptual classifications. We investigated whether adaptive perceptual learning in skin cancer screening can be enhanced by incorporating signal detection theory (SDT) methods that separate sensitivity from criterion. SDT-style concepts were used to alter sequencing, and separately to define mastery (category retirement). SDT retirement used a running d' estimate calculated from a recent window of trials based on hit and false alarm rates. Undergraduate participants used a Skin Cancer PALM (perceptual adaptive learning module) to learn classification of 10 cancerous and readily-confused non-cancerous skin lesion types. Four adaptive conditions varied either the type of adaptive sequencing (standard vs. SDT) or retirement criteria (standard vs. SDT). A non-adaptive control condition presented didactic instruction on dermatologic screening in video form, including images, classification schemes, and detailed explanations. All adaptive conditions robustly outperformed the non-adaptive control in both learning efficiency and fluency (large effect sizes). Between adaptive conditions, SDT retirement criteria produced greater learning efficiency than standard, accuracy-based mastery criteria at both immediate and delayed posttests (medium effect sizes). SDT sequencing and standard adaptive sequencing did not differ. SDT enhancements to adaptive perceptual learning procedures have potential to enhance learning efficiency.

Concentrated diffusing colloidal probes of Ca2+-dependent cadherin interactions.

We report video microscopy measurements and inverse simulation analyses of specific Ca(2+)-dependent interactions between N-cadherin fragments attached to supported lipid bilayer-coated silica colloids in quasi-2D concentrated configurations. Our results include characterization of the bilayer formation and fluidity and the attachment of active extracellular cadherin fragments on bilayers. Direct measurements of interaction potentials show nonspecific macromolecular repulsion between cadherin fragments in the absence of Ca(2+) and irreversible bilayer fusion via cadherin-mediated attraction at >100 µM Ca(2+). Analysis of Ca(2+)-dependent N-cadherin bond formation in quasi-2D concentrated configurations using inverse Monte Carlo and Brownian Dynamics simulations show measurable attraction starting at 0.1 µM Ca(2+), a concentration significantly below previously reported values.

Neuro-Ophthalmology in Emergency Medicine.

Understanding the anatomy and physiology of the eye, the orbit, and the central connections is key to understanding neuro-ophthalmologic emergencies. Anisocoria is an important sign that requires a systematic approach to avoid misdiagnosis of serious conditions, including carotid dissection (miosis) and aneurysmal third nerve palsy (mydriasis). Ptosis may be a sign of either Horner syndrome or third nerve palsy. An explanation should be pursued for diplopia since the differential diagnosis ranges from the trivial to life-threatening causes.

Gene therapy for radioprotection.

Radiation therapy is a critical component of cancer treatment with over half of patients receiving radiation during their treatment. Despite advances in image-guided therapy and dose fractionation, patients receiving radiation therapy are still at risk for side effects due to off-target radiation damage of normal tissues. To reduce normal tissue damage, researchers have sought radioprotectors, which are agents capable of protecting tissue against radiation by preventing radiation damage from occurring or by decreasing cell death in the presence of radiation damage. Although much early research focused on small-molecule radioprotectors, there has been a growing interest in gene therapy for radioprotection. The amenability of gene therapy vectors to targeting, as well as the flexibility of gene therapy to accomplish ablation or augmentation of biologically relevant genes, makes gene therapy an excellent strategy for radioprotection. Future improvements to vector targeting and delivery should greatly enhance radioprotection through gene therapy.

Reconfigurable multi-scale colloidal assembly on excluded volume patterns.

The ability to create multi-scale, periodic colloidal assemblies with unique properties is important to emerging applications. Dynamically manipulating colloidal structures via tunable kT-scale attraction can provide the opportunity to create particle-based nano- and microstructured materials that are reconfigurable. Here, we report a novel tactic to obtain reconfigurable, multi-scale, periodic colloidal assemblies by combining thermoresponsive depletant particles and patterned topographical features that, together, reversibly mediate local kT-scale depletion interactions. This method is demonstrated in optical microscopy experiments to produce colloidal microstructures that reconfigure between well-defined ordered structures and disordered fluid states as a function of temperature and pattern feature depth. These results are well described by Monte Carlo simulations using theoretical depletion potentials that include patterned excluded volume. Ultimately, the approach reported here can be extended to control the size, shape, orientation, and microstructure of colloidal assemblies on multiple lengths scales and on arbitrary pre-defined pattern templates.

Epidemiologic observations of operating room infections resulting from variations in ventilation and temperature.

Over a period of years the ventilation system of a community hospital progressively deteriorated until it no longer met regulatory guidelines. The hospital, a publicly funded military facility, requested funding to repair the ventilation system, but funds were not forthcoming because of budget austerity. When an increase in infections was documented, high-risk operations were curtailed and funding was expedited. With the new improved ventilation system the operating rooms once again met regulatory guidelines and infections returned to baseline rates. Throughout the period infections remained below recognized national levels.

Hemoglobin E and glucose-6-phosphate deficiency in the Khmer Air Force (Cambodia).

This study was designed to investigate the use of primaquine in malaria control in the Khmer Republic (Cambodia). Blood was drawn from 106 male Khmer Air Force troops for analysis of hemoglobin E and glucose-6-phosphate (G-6-PD) deficiency. A test group of 15 men with G-6-PD deficiency and a group of 31 normal controls were given 15 mg of primaquine each morning for 14 days. The patients were followed for hemoglobinuria and changes in hematocrit. Primaquine induced a significant, but not a dangerous, hemolysis in G-6pD-deficient Khmer troops. The G-6-PD deficiency seen in Khmer Air Force subjects was G-6-PD Mahidol. Statistically, G-6-PD Mahidol was linked to hemoglobin E.

Hepatitis B prevention strategies: a benefit-cost analysis of immune serum globulin, hepatitis B immune globulin, and hepatitis B vaccine in the military.

The new hepatitis B vaccine is an effective method of preventing hepatitis B infection. However, its expense could contribute greatly to health care costs, with little marginal benefit if it is used indiscriminately. This study analyzes the relative risk of hepatitis among various health care workers to determine the relative merits of a vaccine strategy. It was found that the average cost of a hepatitis B vaccine in health care facilities is greatly reduced the closer the worker is to a dialysis unit. This might justify not using the vaccine at all in health care workers at facilities without dialysis. Analyzing the marginal cost of immune serum globulin (ISG) versus hepatitis B immune globulin (HBIG) and hepatitis B vaccine in a needle-stick protocol, it was determined that the increased protection provided by HBIG and hepatitis B vaccine comes at a cost that would be considered prohibitive by many prudent decision-makers. A separate analysis of the use of hepatitis B vaccine versus ISG in troops assigned to Korea found that most decision-makers might think the cost of hepatitis B vaccine prohibitive, with the benefits mostly speculative and unproved. Data are not available that would allow a benefit-cost analysis of hepatitis B vaccine in most dental personnel.(ABSTRACT TRUNCATED AT 250 WORDS)

Screening for gestational diabetes: an analysis of health benefits and costs.

The current recommendation to screen all pregnant mothers for diabetes at 28 weeks of gestation is examined using known epidemiological evidence in a cost-benefit analysis. The available data indicate that the potential decrease in the perinatal mortality rate would be the most cost-efficient potential health outcome of a gestational diabetes screening policy. A decrease in macrosomia and cesarean sections would be additional potential benefits, but at a cost so great that it is not an important factor in making a decision to screen for gestational diabetes. Since it is unlikely that a study can be done that would ethically demonstrate the effectiveness of universal screening in decreasing the perinatal mortality rate, further research should perhaps focus on decreasing the cost of screening, as the available data do not clearly demonstrate a favorable cost-benefit ratio in universal screening for gestational diabetes.

Collaborative community research consortium: a model for HIV prevention.

In 1991, the Center for AIDS Prevention Studies (CAPS) at the University of California, San Francisco, set out to develop a model of community collaborative research that would bring the skills of science to the service of HIV prevention and the knowledge of service providers into the domain of research. Essential elements of the model were training for community-based organizations (CBOs) in research protocol writing, partnership between CBOs and CAPS researchers, program research funding, support to implement studies and analyze results, and a program manager to oversee the effort and foster the relationships between CBOs and researchers. In this article, the authors describe the CAPS model of consortium-based community collaborative research. They also introduce a set of papers, written by researchers and service providers, that describes collaborative research projects conducted by research institutions and CBOs and illustrates how collaboration can change both HIV prevention research and service.

Medical group adoption of Internet services.

Physician leaders and office-based practicing physicians in medium and large practice organizations were surveyed regarding their use of administrative and clinical systems enabled by the Internet. More than 85% of medical groups reported using one or more Internet-enabled services and 35 reported use of more than five Internet-enabled services, including both business and clinical applications. Physician leaders and practicing physicians identified six Internet-enabled services as "essential" for the future success of their practice and indicated that reduced administrative costs, faster payments, and improved quality of care are the most important benefits derived from Internet-enabled applications. Ninety-six percent of survey respondents estimated that Internet-enabled technologies will have a significant, positive impact on the practice of medicine in general and will improve the quality of care before 2003. The lack of industrywide standards for health information and the inability of current computer systems to exchange information across health care delivery networks were cited as the most important barriers to the adoption of Internet-enabled applications by physicians. Respondents believed that action by the Health Care Financing Administration (HCFA) or major health plans to require participating physicians to use the Internet for administrative services will be needed to bring about rapid migration to Internet-enabled services.

Retinal detachment following congenital cataract surgery.

It is hoped that the results of surgery for retinal detachment after surgery for congenital cataract, when discission and aspiration or phacoemulsification under the microscope are used, will approach the present reattachment rate that has been achieved with improved examination, instrumentation, and surgical technique in cases of senile retinal detachment. Further studies of the role of retinal pathology as lattice degeneration, vitreous pathology, and the place for prophylactic cryotherapy all must be reevaluated. In summary, the low incidence of retinal detachment following the extraction of congenital cataracts as seen in major retinal referral centers suggests that the risks of detachment are not as high as previously reported, that the cure rate approaches that of senile aphakic detachment; therefore early operative intervention to prevent amblyopia, nystagmus, and strabismus is indicated.

Sutures, incisions, and anastomoses.

The properties of different types of suture material are reviewed, with particular reference to the complications which may result from their use. The aetiology, prevention, diagnosis, and treatment of wound dehiscence are discussed. The factors which are believed to be important in performing successful bowel anastomosis are considered.

Comparison of early and late closure of transverse loop colostomies.

A retrospective study was made from the records of 100 consecutive patients who had closure of a temporary transverse colostomy at Addenbrooke's Hospital, Cambridge, between 1969 and 1982. Thirtyeight colostomies were closed early, approximately 2 weeks after the initial bowel resection and during the same hospital admission. The closure technique in the majority of cases involved resecting the bowel ends and performing a single layer anastomosis with interrupted Supramid. Statistically there was no difference in overall or individual complications, such as faecal fistulae and wound infections, in the early compared with the late colostomy closure group. The length of stay in hospital after closure was almost identical in both groups. This is true despite a higher proportion of operations in the early closure group being performed by less experienced surgeons. Early closure of a temporary colostomy is a relatively safe procedure and has obvious advantages for rehabilitation.

The functional result of pelvic ileal reservoir in 10 patients with familial adenomatous polyposis.

Ten patients with familial adenomatous polyposis (FAP) were treated by total colectomy, mucosal protectomy and ileoanal anastomosis with a pelvic ileal reservoir. The functional results were assessed by means of a patient questionnaire and suggested that this operation may represent the ideal treatment for the condition, irradicating disease-bearing mucosa, avoiding an ileostomy and providing acceptable function.