Publications by authors named "Youmans A"

To benchmark the accuracy of the models and improve the predictive capability of future experiments, the National Ignition Facility requires measurements of the physical conditions inside inertial confinement fusion hohlraums. The ion temperature and bulk motion velocity of the gas-filled regions of the hohlraum can be obtained by replacing the helium tamping gas in the hohlraum with deuterium-tritium (DT) gas and measuring the Doppler broadening and Doppler shift of the neutron spectrum produced by nuclear reactions in the hohlraum. To understand the spatial distribution of the neutron production inside the hohlraum, we have developed a new penumbral neutron imager with a 12 mm diameter field of view using a simple tungsten alloy spindle.

View Article and Find Full Text PDF

On pulsed fusion experiments, the neutron time of flight (nToF) diagnostic provides critical information on the fusion neutron energy spectrum. This work presents an analysis technique that uses two collinear nToF detectors, potentially to measure nuclear bang time and directional flow velocities. Two collinear detectors may be sufficient to disambiguate the contributions of nuclear bang time and directional flow velocities to the first moment of the neutron energy spectrum, providing an independent measurement of nuclear bang time.

View Article and Find Full Text PDF

The sheared-flow-stabilized Z pinch concept has been studied extensively and is able to produce fusion-relevant plasma parameters along with neutron production over several microseconds. We present here elevated electron temperature results spatially and temporally coincident with the plasma neutron source. An optical Thomson scattering apparatus designed for the FuZE device measures temperatures in the range of 1-3 keV on the axis of the device, 20 cm downstream of the nose cone.

View Article and Find Full Text PDF

Sepsis in obstetric care is one of the leading causes of maternal death in the United States, with Black, Asian/Pacific Islander, and American Indian/Alaska Native obstetric patients experiencing sepsis at disproportionately higher rates. State maternal mortality review committees have determined that deaths are preventable much of the time and are caused by delays in recognition, treatment, and escalation of care. The "Sepsis in Obstetric Care" patient safety bundle provides guidance for health care teams to develop coordinated, multidisciplinary care for pregnant and postpartum people by preventing infection and recognizing and treating infection early to prevent progression to sepsis.

View Article and Find Full Text PDF

Nasogastric feeding tubes are commonly used in medical practice to provide nutritional support to patients who cannot take in an adequate amount of food orally. Although rare, nasogastric tubes errantly placed into the respiratory tract may cause serious complications, including death. We present an unusual autopsy case of a fatal hydrothorax that consisted of the enteric feeding solution following placement of a small-bore feeding tube into the left lung, despite no perforation of the tracheobronchial tree or esophagus.

View Article and Find Full Text PDF

The popularity of e-cigarettes (vaping) has been on the rise in recent years, but the adverse effects of vaping have been greatly unknown. In 2019, the use of vaping products has been linked to an outbreak of severe lung disease, some cases of which have progressed to death. One death attributed to vaping is presented with emphasis on the gross and histopathological findings from the autopsy.

View Article and Find Full Text PDF

Purpose: Similar to other molecularly targeted agents, temsirolimus, an inhibitor of mammalian target of rapamycin, has shown promising activity in advanced renal cell carcinoma. However, only a subset of patients appears to derive significant tumor responses. In an effort to identify potential predictors of response to temsirolimus, tumor samples from a subset of patients within a randomized phase II trial of temsirolimus in advanced renal cell carcinoma were studied.

View Article and Find Full Text PDF

The authors examined pathology from patients with renal cancer (RCC) treated with IL-2 to determine response rates for clear cell and variant RCC and to identify histologic features that predict response. Pathology specimens were reviewed by a single pathologist who was blinded to both the prior pathology interpretation and the therapeutic response. Findings were correlated with response to IL-2 therapy.

View Article and Find Full Text PDF

Purpose: Renal cancer response to interleukin 2 (IL-2) therapy and patient survival has been correlated with tumor histology and carbonic anhydrase IX (CAIX) expression. In an effort to confirm and expand these observations, we examined CAIX expression in pathology specimens from renal cancer patients who had previously received IL-2 therapy.

Experimental Design: Paraffin-embedded tissue sections of renal cancer were immunostained with the MN-75 monoclonal antibody to CAIX and expression levels were correlated with histologic findings and clinical outcome.

View Article and Find Full Text PDF

Myeloid suppressor cells with high arginase activity are found in tumors and spleen of mice with colon and lung cancer. These cells, described as macrophages or immature dendritic cells, deplete arginine and impair T cell proliferation and cytokine production. Although arginase activity has been described in cancer patients, it is thought to originate from tumor cells metabolizing arginine to ornithine needed to sustain rapid cell proliferation.

View Article and Find Full Text PDF

The effect of a number of metabolic inhibitors was determined on: (i) the production of cellular immunity to infection with Mycobacterium tuberculosis in mice by vaccination with mycobacterial ribonucleic acid (RNA), (Ii) the production of cellular immunity to infection with M. tuberculosis in mice with viable H37Ra cells, (iii) the induction of antibody formation to sheep erythrocytes, and (iv) the induction of delayed hypersensitivity in mice to purified protein derivative. The pattern of inhibition produced by metabolic inhibitors on cellular immunity to infection with M.

View Article and Find Full Text PDF

Mycobacterial ribonucleic acid preparations from H37Ra, an attenuated strain of Mycobacterium tuberculosis, provide their usual marked protection against M. tuberculosis challenge; however, they provided no protection against Mycobacterium leprae challenge. Suspensions of intact H37Ra were not effective against M.

View Article and Find Full Text PDF

Mycobacterial ribonucleic acid (RNA) and cell wall skeleton fraction isolated from H37Ra caused P-815 mastocytoma regression in DBA/2 mice provided the animals were presensitized with freshly harvested living H37Ra cells. In the absence of presensitization, only the RNA fraction inhibited. Cell wall skeleton fraction, under these conditions, stimulated tumor growth.

View Article and Find Full Text PDF

Our experimental data imply the following: (1) An RNA-rich fraction isolated from H37Ra, and intact H37Ra, are effective agents for suppression of tumor growth. (2) For suppression of two chemically-induced tumors with both RNA and H37Ra, direct contact with tumor is necessary. This may not be the case with other tumors in different strains of syngeneic mice.

View Article and Find Full Text PDF

Mice vaccinated with mycobacterial ribonucleic acid (RNA) produced a high immune response and did not develop delayed hypersensitivity to purified protein derivative (PPD), and rifampin had no effect on the immune response. Mice vaccinated with viable H37Ra cells produced a high immune response and did develop delayed hypersensitivity to PPD. Rifampin had no effect on this immune response, but reduced the footpad reactions to PPD.

View Article and Find Full Text PDF

The migration inhibition technique has been used to study delayed hypersensitivity in vitro by using peritoneal exudate cells and splenic lymphocytes from mice vaccinated with viable cells of the attenuated H37Ra strain of Mycobacterium tuberculosis and from mice vaccinated with ribonucleic acid (myc RNA) preparations obtained from viable mycobacterial cells of the same strain. Inhibition of macrophage migration was noted when purified protein derivative (PPD) or viable H37Ra cells were added to peritoneal exudate cells obtained from mice immunized with viable H37Ra cells and not from mice immunized with myc RNA. Splenic lymphocyte cultures were exposed to the same antigens in vitro.

View Article and Find Full Text PDF

The five polybasic amines, methylated bovine serum albumin (MBSA), protamine sulfate, neomycin sulfate, streptomycin sulfate, and diethylaminoethyl-dextran (DEAE-dextran), were examined to determine their effects on the immunogenic activity of mycobacterial ribonucleic acid (RNA) preparations, and whether they could substitute for Freund incomplete adjuvant (FIA) by protecting the mycobacterial RNA in vivo. These compounds were either emulsified in FIA or not emulsified in FIA. Different results were obtained when these compounds, complexed with mycobacterial RNA, were emulsified in FIA.

View Article and Find Full Text PDF

Data are presented which show that the syngeneic C57B1/6 mouse strain is far more susceptible to infection with Mycobacterium tuberculosis strain H37Rv than are the other allogeneic mouse strains used in this laboratory, particularly the Strong A and the CF-1 strains. Not only are the C57B1/6 mice more susceptible to tuberculous infection, but also they respond to infection more uniformly than do the allogeneic strains. C57B1/6 mice develop immunity to challenge with small infecting doses of the virulent H37Rv strain when they are vaccinated with viable cells of the attenuated H37Ra strain and with ribonucleic acid (RNA) preparations isolated from the H37Ra strain.

View Article and Find Full Text PDF