Ordering of ruthenium cluster carbonyls in mesoporous silica

The anionic ruthenium cluster carbonylates [Ru6C(CO)16]2- or [H2Ru10(CO)25]2- interspersed with bis(triphenylphosphino)iminium counterions (PPN+) are incorporated from solution into the pores of MCM-41 mesoporous silica (3 nanometers in diameter), where they form tightly packed arrays. These arrays were shown by high-resolution transmission electron microscopy, Fourier transform optical diffraction, and computer simulations to be well ordered both along and perpendicular to the axis of the cylindrical pores. In their denuded state produced by gentle thermolysis, the cluster carbonylates yield nanoparticles of ruthenium that are less well ordered than their assimilated precursors but show good activity as hydrogenation catalysts for hexene and cyclooctene. In both their as-prepared and denuded states, these encapsulated clusters are likely to exhibit interesting electronic and other properties.     

Near extinction of a large, widely distributed fish

Are extinctions of marine vertebrates as rare and unlikely as current data indicate? Long-term research surveys on the continental shelf between the Grand Banks of Newfoundland and southern New England reveal that one of the largest skates in the northwest Atlantic, the barndoor skate (Raja laevis), is close to extinction. Forty-five years ago, research surveys on St. Pierre Bank (off southern Newfoundland) recorded barndoor skates in 10% of their tows; in the last 20 years, none has been caught, and this pattern of decline is similar throughout the range of the species.     

Spatial Variability of Turbulent Mixing in the Abyssal Ocean

Ocean microstructure data show that turbulent mixing in the deep Brazil Basin of the South Atlantic Ocean is weak at all depths above smooth abyssal plains and the South American Continental Rise. The diapycnal diffusivity there was estimated to be less than or approximately equal to 0.1 x 10(-4) meters squared per second. In contrast, mixing rates are large throughout the water column above the rough Mid-Atlantic Ridge, and the diffusivity deduced for the bottom-most 150 meters exceeds 5 x 10(-4) meters squared per second. Such patterns in vertical mixing imply that abyssal circulations have complex spatial structures that are linked to the underlying bathymetry.     

Efficacy and Toxicity of VAC Chemotherapy (Vincristine, Doxorubicin, and Cyclophosphamide) in Dogs with Hemangiosarcoma

Fifteen dogs with hemangiosarcoma were treated with a combination of vincristine, doxorubicin, and cyclophosphamide after incisional or excisional biopsy. The median survival for all fifteen dogs was 172 days (mean survival = 316 days). The median survival for those dogs with splenic hemangiosarcoma was 145 days (mean survival = 271 days) as compared with previously published median survival times in dogs with splenic hemangiosarcoma treated with surgery alone of 19 to 65 days. Toxicities included neutropenia (11/15), severe gastroenteritis (4/15), cardiotoxicity (3/15), and sepsis (2/15). The authors conclude that vincristine, doxorubicin, and cyclophosphamide chemotherapy may be an efficacious treatment modality in dogs with hemangiosarcoma and is associated with acceptable toxicity.     

Harbour seal (Phoca vitulina) abundance within the Firth of Tay and Eden Estuary,Scotland: recent trends and extrapolation to extinction

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Significant increases in pulping efficiency in C4H-F5H-transformed poplars: improved chemical savings and reduced environmental toxins

The gene encoding ferulate 5-hydroxylase (F5H) was overexpressed in poplar (Populus tremula x Populus alba) using the cinnamate-4-hydroxylase (C4H) promoter to drive expression specifically in cells involved in the lignin biosynthetic pathway and was shown to significantly alter the mole percentage of syringyl subunits in the lignin, as determined by thioacidolysis. Analysis of poplar transformed with a C4H-F5H construct demonstrated significant increases in chemical (kraft) pulping efficiency from greenhouse-grown trees. Compared to wild-type wood, decreases of 23 kappa units and increases of >20 ISO brightness units were observed in trees exhibiting high syringyl monomer concentrations. These changes were associated with no significant modification in total lignin content and no observed phenotypic differences. C4H-F5H-transformed trees could increase pulp throughputs at mills by >60% while concurrently decreasing chemicals employed during processing (chemical pulping and bleaching) and, consequently, the amount of deleterious byproducts released into the environment.     

Effect of bovine seminal plasma on bovine endometrial epithelial cells in culture

The purpose of this study was to investigate the effect of seminal plasma (SP) from bulls of known fertility on bovine endometrial epithelial cells (bEEC) in culture. The bEEC from passage 5, approximately 5.0–13 × 10⁵ cells per flask, were challenged with SP from bulls of high or low fertility (n = 3 and 2, respectively) or PBS (control), at 1% (75 μl) or 4% (300 μl) and were incubated for 72 hr (n = 13 per challenge). Total cell number and viability of bEEC after challenge with 1% SP from either high‐ or low‐fertility bulls (75H or 75L, respectively) did not differ from controls. In contrast, challenge with 4% of SP from high‐ or low‐fertility bulls (300H or 300L) negatively affected bEEC cell number and viability. Challenge with 300 L had a greater adverse effect than 300H. These results suggest that the negative effect of bovine SP on bEEC is both dose‐dependent and fertility‐dependent.