Upper stage flight experiment (USFE) integral structure development effort

The Air Force Research Laboratory's Space Vehicle Directorate (AFRL/VS) has established a customer focused composite tankage development program that is targeted to existing and future aerospace applications. AFRL/VS is developing a wide range of tank concepts that include linerless cryogenic tankage, self-healing cryogenic tankage, hydrogen peroxide compatible tankage, volumetrically efficient toroidal (donut shaped) geometries, and more.

This paper will summarize the Upper Stage Flight Experiment (USFE) composite integral structure development effort. The integral structure refers to the stage skirt and the propellant tankage. These two parts are bonded together to form an integral structure. The USFE tank is the world's first composite, common-bulkhead, medium-pressure vessel designed to be Class 1 Compatible with high concentrations of hydrogen peroxide. Lightweight hydrogen peroxide compatible tankage development is becoming increasingly important to the international aerospace community because it provides considerable benefits. Peroxide can be stored unpressurized and is relatively non-toxic, which makes it safer to handle and store compared to oxidizers such as hydrazine. In addition to being a viable bi-propellant oxidizer, hydrogen peroxide can also serve as a monopropellant for an attitude control system (ACS). Peroxide is not cryogenic, therefore, it does not require an on-board cryocooler, which makes it easier to meet mass budgets and to mitigate technical risk. Storability and ease of handling make high concentration hydrogen peroxide an ideal propellant for reusable launch vehicle (RLV) responsive upper stage applications.     

L- and T-type calcium currents differ in finch and rat ventricular cardiomyocytes

We compared L-type Ca current (ICaL) and T-type Ca current (ICaT) in finch and rat myocytes, using whole-cell patch clamp techniques. Cell capacitance averaged 50 +/- 4 pF in finch (n = 25) v 145 +/- 8 pF in rat (n = 38) cells, P < 0.001. In cells bathed in 1 mM Cao at 22 degrees C, peak ICaL amplitude, during a voltage clamp step (10 mM EGTA in pipette) from -45 mV to -5 mV, averaged 10.5 +/- 0.3 pA/pF in finch v 6.9 +/- 0.6 pA/pF, P < 0.001 in rat cells. ICaL inactivation kinetics were faster in finch (4.6 +/- 0.3 ms) than in rat (13.4 +/- 1.3 ms) cells. P < 0.001. ICaT was not detectable in rat cells (2 mM bathing [Ca]); but in finch cells, a large ICaT which averaged 6.8 +/- 1.4 pA/pF was activated at -30 mV and was relatively insensitive to nitrendipine (0.1 microM). The distinctive features of ICaL and ICaT in finch cells may have a role in the ability of the finch to achieve a very rapid heart rate. They may also facilitate excitation-Ca2+ release coupling in finch ventricular cells which are devoid of T tubules and have relatively few junctions between the sarcolemma and the sarcoplasmic reticulum.     

NIOSH research initiatives to prevent back injuries to nursing assistants, aides, and orderlies in nursing homes

Over the past 100 years, advances in nutrition, modern medicine, public health, and a multitude of public health improvements have increased the life expectancy of U.S. residents. The fact that Americans are living longer has resulted in extensive growth in our elderly population and a rapid employment growth that delivered about 2 million new jobs between 1980 and 1989 in the health care workforce. The Bureau of Labor Statistics Injury and Illness Data for nursing homes rose from 10.7 to 18.6 injuries or illnesses per 100 full-time workers between 1980 and 1992. The injury and illness rates among nursing home workers are partly due to the physical stress of providing round-the-clock assistance with the basic activities of daily living, such as getting in and out of a bed or chair, as well as bathing and toileting. The National Institute for Occupational Safety and Health (NIOSH) is conducting a series of research studies to identify strategies to reduce the risk of musculoskeletal injuries to workers in nursing homes. NIOSH has funded two laboratory evaluations of resident transferring methods and one field study in an actual nursing home. The purpose of this paper is to describe the key findings from past NIOSH research initiatives and to present an overview of future research.     

Sialic acid-dependent recognition of laminin by Penicillium marneffei conidia

Immunofluorescence microscopy demonstrated that laminin bound to the surface of Penicillium marneffei conidia. Attachment of P. marneffei conidia in an adherence assay was inhibited by soluble laminin and anti-laminin antibody. N-Acetylneuraminic acid abolished adherence, indicating an interaction mediated by a sialic acid-specific lectin.     

Concussion history in elite male and female soccer players

BACKGROUND/AIMS: Recent studies in primary biliary cirrhosis have reported the detection of serum antibodies against Mycobacterium gordonae and of mycobacterial DNA in liver sections. The aim of this study was to investigate whether mycobacterial DNA is present in liver biopsy material in primary biliary cirrhosis. METHODS: Archival liver biopsy specimens from 11 patients with primary biliary cirrhosis (10 female, mean age 52 years) and 11 patients with autoimmune hepatitis (10 female, mean age 53 years) were identified. Positive control tissue comprised five archival lymph node specimens from patients with tuberculous lymphadenopathy, three of which had stained positive on ZN staining, and also a liver biopsy specimen from a patient with tuberculous hepatitis (ZN positive). Fixed sections were deparaffinised and DNA was extracted by mechanical disruption with glass beads. DNA was purified by use of diatoms and lysis in guanidinium thiocyanate in a technique previously validated for archival DNA. Primers were directed to amplify a partial 16S ribosomal RNA gene yielding the species-specific character for mycobacteria, and also to amplify the constitutively-expressed human gene GAPDH. RESULTS: The polymerase chain reaction was shown to be capable of detecting 1 fg of M. gordonae DNA in 'spiked' samples, equivalent to 1-5 bacterial cells. No mycobacterial DNA was detected in liver biopsy samples from either the primary biliary cirrhosis or autoimmune hepatitis groups. Of the tuberculous control sections, mycobacterial DNA was detected in four of five lymph nodes and the liver biopsy specimen. GAPDH amplification was detected in all tested samples from liver disease and tuberculous control samples. CONCLUSION: These data do not support a role for mycobacteria in the aetiology of primary biliary cirrhosis.