AgCl-doped CdSe quantum dots with near-IR photoluminescence.

We report the synthesis of colloidal CdSe quantum dots doped with a novel Ag precursor: AgCl. The addition of AgCl causes dramatic changes in the morphology of synthesized nanocrystals from spherical nanoparticles to tetrapods and finally to large ellipsoidal nanoparticles. Ellipsoidal nanoparticles possess an intensive near-IR photoluminescence ranging up to 0.

Studies on the inhalation toxicology of two fiberglasses and amosite asbestos in the Syrian golden hamster. Part II. Results of chronic exposure.

Fiberglass (FG) is the largest category of man-made mineral fibers (MMVFs). Many types of FG are manufactured for specific uses building insulation, air handling, filtration, and sound absorption. In the United States, > 95% of FG produced is for building insulation.

Studies on the chronic toxicity (inhalation) of four types of refractory ceramic fiber in male Fischer 344 rats.

Abstract Refractory ceramic fibers (RCF) are man-made vitreous fibers used primarily in industrial high-temperature applications, especially for insulation of furnaces and kilns. Because of their increasing use and potential for human exposure, a chronic toxicity/carcinogenicity inhalation study was conducted in Fischer 344 (F344) rats. Five groups of 140 weanling male F344 rats were exposed via noseonly inhalation to either HEPA-filtered air (chamber controls) or 30 mg/m(3) (approximately 220 fibers/cm(3)) of three types [kaolin-based, high-purity, and aluminum zirconia silica (AZS)] of "size-selected" RCF fibers (approximately 1µ in diameter and approximately 20 um in length) and an "after-service" heat-treated (2400°F for 24 h) kaolin-based fiber for 6 h/day, 5 days/wk for 24 mo.

Multiple-dose chronic inhalation toxicity study of size-separated kaolin refractory ceramic fiber in male Fischer 344 rats.

Abstract Refractory ceramic fibers (RCF) are man-made vitreous fibers used primarily in industrial high-temperature applications, especially for insulation of furnaces and kilns. Because of their increasing use and potential for human exposure an in an effort to define the dose-response, as a follow up to a maximum tolerated dose [30 mg/m(3)] study in rats (Mast et al., 1995), a multiple dose chronic toxicity/carcinogenicity inhalation study was conducted in Fischer 344 (F344) rats.

Rewards for cancer control with use of biologic markers and end points.

The increasing availability of biologic markers and end points offers significant potential for improvement in cancer control. These tools are underutilized today, but it is clear that they can be major assets to pathologists, clinicians, epidemiologists, and ultimately to programs designed for preventive or therapeutic intervention in populations and individuals at high cancer risk.

Evaluation for compensation of asbestos-exposed individuals. II. Apportionment of risk for lung cancer and mesothelioma.

The incidence of lung cancer in the cigarette smoking population occupationally exposed to asbestos is inordinately high. A method for apportioning risk to these two agents has been developed. It utilizes degree of asbestos and smoking exposures; the time interval from onset and, where applicable, termination of both exposures; the time interval to diagnosis of lung cancer; and morphologic, physiologic, and radiological evidence of pulmonary fibrosis.

Evaluation for compensation of asbestos-exposed individuals. I. Detection and quantification of asbestos-related nonmalignant impairment.

An objective method for measuring nonmalignant respiratory impairment caused by inhaled asbestos has been devised. Three standard physiologic tests (the forced vital capacity [FVC], the forced expiratory volume in 1 s [FEV1], the single-breath diffusing capacity for carbon monoxide [DCO]) and the posteroanterior chest roentgenogram are utilized. The age-, height-, and sex-specific normal ranges of the FVC%, the DCO%, and the FEV1/FVC% have been used in the method.

Embryonal neoplasms in the opossum: a new model for solid tumors of infancy and childhood.

Opossums fed the chemical carcinogen ethyl nitrosourea early in postnatal life developed a variety of epithelial and mesenchymal embryonal neoplasms that were closely analogous, in morphology and biological behavior, to tumors of human infancy and childhood for which experimental models in laboratory animals are either imprecise or nonexistent. The embryonal tumors were found in association with, and occasionally at the same sites as, a limited number of malformations.

Mouse leukemia virus activation by chemical carcinogens.

The induction of lymphomas in C57BL mice by methylcholanthrene, urethan, or diethylnitrosamine was accompanied by the development of murine leukemia viral antigen in most of the lymphoid tumors. The cell-free transmission of lymphomas induced by methylcholanthrene and the development of antibody to murine leukemia virus prior to the detection of overt lymphoma in these mice suggest that unmasking of a latent leukemia virus is an indigenous actuating cause of the lymphomas.