Evidence for spindle apparatus in somatic nuclei

Evidence for spindle apparatus in somatic nucle

Ultrastructure of slime

Ultrastructure of slim

THORIUM BREEDER REACTOR EVALUATION. PART I. FUEL YIELD AND FUEL CYCLE COSTS IN FIVE THERMAL BREEDERS. APPENDICES

The performances of aqueous-homogeneous (AHBR), molten-salt (MSBR), liquid-bismuth (LBBR), gas-cooled graphite-moderated (GCBR), and deuterium- moderated gascooled (DGBR) breeder reactors were evaluated in respect to fuel yield, fuel cycle costs, and development status. A net electrical plant capability of 1000 Mwe was selected with continuous processing of fuel and fertile streams. The maximum annual fuel yields were 16, 7, 4, 4, and 4.5%/yr, respectively at a fuel cycle cost of 1.5 mills/kwhr. The minimum estimated fuel cycle costs were 0.9, 0.6, 1.0, 1.2, and 1.3 mills/kwhr at fuel yields of 7, 1, 1, 2, and 3%/yr. At a fuel yield of 4%/yr, the costs were 0.9, 0.9, 1.5, 1.5, and 1.3 mills/kwhr. Only the AHBR and the MSBR are capable of achieving fuel yields substantially in excess of 4%/yr, and therefore only these two can be listed with confidence as being able to satisfy the mdin criterion of the AEC long-range thorium breeder program i.e., a doubling time of 25 years or less. The development effort required to bring the various concepts to the stage where a prototype station could be designed was estimated to be least for the AHBR, somewhat more for the MSBR, and several times as much for the other systems. The AHBR was judged to rank first in regard to nuclear capability, fuel cycle potential, and status of development. (auth

Degradation, infection and heat effects on polypropylene mesh for pelvic implantation: what was known and when it was known

Many properties of polypropylene mesh that are causative in producing the complications that our patients are experiencing were published in the literature prior to the marketing of most currently used mesh configurations and mesh kits. These factors were not sufficiently taken into account prior to the sale of these products for use in patients. This report indicates when this information was available to both mesh kit manufacturers and the Food and Drug Administration

Defects in Chiral Columnar Phases: Tilt Grain Boundaries and Iterated Moire Maps

Biomolecules are often very long with a definite chirality. DNA, xanthan and poly-gamma-benzyl-glutamate (PBLG) can all form columnar crystalline phases. The chirality, however, competes with the tendency for crystalline order. For chiral polymers, there are two sorts of chirality: the first describes the usual cholesteric-like twist of the local director around a pitch axis, while the second favors the rotation of the local bond-orientational order and leads to a braiding of the polymers along an average direction. In the former case chirality can be manifested in a tilt grain boundary phase (TGB) analogous to the Renn-Lubensky phase of smectic-A liquid crystals. In the latter case we are led to a new "moire" state with twisted bond order. In the moire state polymers are simultaneously entangled, crystalline, and aligned, on average, in a common direction. In the moire state polymers are simultaneously entangled, crystalline, and aligned, on average, in a common direction. In this case the polymer trajectories in the plane perpendicular to their average direction are described by iterated moire maps of remarkable complexity, reminiscent of dynamical systems.Comment: plain TeX, (33 pages), 17 figures, some uufiled and included, the remaining available at ftp://ftp.sns.ias.edu/pub/kamien/ or by request to [email protected]

Sex differences in the impact of ozone on survival and alveolar macrophage function of mice after Klebsiella pneumoniae infection

<p>Abstract</p> <p>Background</p> <p>Sex differences have been described in a number of pulmonary diseases. However, the impact of ozone exposure followed by pneumonia infection on sex-related survival and macrophage function have not been reported. The purpose of this study was to determine whether ozone exposure differentially affects: 1) survival of male and female mice infected with <it>Klebsiella pneumoniae</it>, and 2) the phagocytic ability of macrophages from these mice.</p> <p>Methods</p> <p>Male and female C57BL/6 mice were exposed to O₃or to filtered air (FA) (control) and then infected intratracheally with <it>K. pneumoniae </it>bacteria. Survival was monitored over a 14-day period, and the ability of alveolar macrophages to phagocytize the pathogen <it>in vivo </it>was investigated after 1 h.</p> <p>Results</p> <p>1) Both male and female mice exposed to O₃are significantly more susceptible to <it>K. pneumoniae </it>infection than mice treated with FA; 2) although females appeared to be more resistant to <it>K. pneumoniae </it>than males, O₃exposure significantly increased the susceptibility of females to <it>K. pneumoniae </it>infection to a greater degree than males; 3) alveolar macrophages from O₃-exposed male and female mice have impaired phagocytic ability compared to macrophages from FA-exposed mice; and 4) the O₃-dependent reduction in phagocytic ability is greater in female mice.</p> <p>Conclusion</p> <p>O₃exposure reduces the ability of mice to survive <it>K. pneumoniae </it>infection and the reduced phagocytic ability of alveolar macrophages may be one of the contributing factors. Both events are significantly more pronounced in female mice following exposure to the environmental pollutant, ozone.</p

Protein kinase A-mediated CREB phosphorylation is an oxidant-induced survival pathway in alveolar type II cells

Oxidant stress plays a role in the pathogenesis of pulmonary diseases, including fibrotic lung disease and cancer. We previously found that hydrogen peroxide (H2O2) initiates an increase in Ca2+/cAMP-response element binding protein (CREB) phosphorylation in C10 alveolar type II cells that requires activation of extracellular regulated kinases 1/2 (ERK1/2). Here, we investigated the role of crosstalk between protein kinase A (PKA) and epidermal growth factor receptor (EGFR) in oxidant-induced signaling to ERK1/2 and CREB in C10 cells. Application of H2O2 increased nuclear accumulation of PKA, and inhibition of PKA with H89 reduced oxidant-mediated phosphorylation of both CREB and ERK1/2. Single cell measurements of cAMP and redox status, using a FRET-based biosensor and a redox-sensitive GFP, respectively, indicated that H2O2 increases production of cAMP that correlates with redox state. Inhibition of EGFR activity decreased both H2O2-induced CREB phosphorylation and translocation of PKA to the nucleus, suggesting that crosstalk between PKA and EGFR underlies the oxidant-induced CREB response. Furthermore, knockdown of CREB expression using siRNA led to a decrease in bcl-2 and an increase in oxidant-induced apoptosis. Together these data reveal a novel role for crosstalk between PKA, ERK1/2 and CREB that mediates cell survival during oxidant stress