Leah Minc

In Vivo Biodistribution of Dendrimers and Dendrimer Nanocomposites — Implications for Cancer Imaging and Therapy

Our results indicate that the surface chemistry, composition, and 3-D structure of nanoparticles are critical in determining their in vivo biodistribution, and therefore the efficacy of nanodevice imaging and therapies. We demonstrate that gold/dendrimer nanocomposites in vivo, present biodistribution characteristics different from PAMAM dendrimers in a B16 mouse tumor model system. We review important chemical and biologic uses of these nanodevices and discuss the potential of nanocomposite devices to greatly improve cancer imaging and therapy, in particular radiation therapy. We also discuss major issues confronting the use of nanoparticles in the near future, with consideration of toxicity analysis and whether biodegradable devices are needed or even desirable.

Clay, Conflict, and Village Aggregation: Compositional Analyses of Pre-Classic Pottery from Taos, New México

As was the case throughout much of north-central New Mexico, the late twelfth and thirteenth centuries marked a period of rapid settlement pattern change in the Taos District as dispersed pithouse and small pueblo hamlets were replaced by tightly clustered pueblos and ultimately by the emergence of large aggregated villages. Here we consider the effects of this transition on the manner in which local potters procured raw clay for the production of black-on-white ceramics. Adopting the Rio Grande del Rancho drainage as our study area, we first outline the major clay sources within the drainage. We then report on neutron activation and petrographic analyses of both modern clays as well as archaeological ceramics from sites that span the settlement transition in question. These analyses suggest that settlement aggregation was accompanied by a noticeable reduction in the diversity and quality of clay sources used by local potters, most likely as a result of newly restricted procurement strategies associated with the formation of buffer zones between village aggregates. The paper concludes with a consideration of the implications of this trend with respect to the economic situation of early large villages in the area.

Field Survey and Geochemical Characterization of the Southern Armenian Obsidian Sources

Abstract In comparison with those of the west Mediterranean, the Aegean, and Anatolia, the numerous obsidian sources in the southern Caucasus have begun to receive archaeological attention only recently. The least research has been directed to the southernmost of these sources, in the province of Syunik in southern Armenia. These sources lie close to the border with Azerbaijan, in remote mountainous uplands reaching elevations above 3200 m and under snow for more than half the year. The flows around the volcanic domes at Bazenk, Satanakar, and Sevkar provide abundant, high-quality obsidian which, although geologically well documented, has been neither adequately characterized in terms of geochemical variability, nor assessed archaeologically with regard to its past utilization. Research at the Syunik obsidian sources has been undertaken since 2005 as one part of the Armenian-American Vorotan Project. The purpose of the fieldwork and analyses presented here was to characterize the flows by means of large-scale sampling for Instrumental Neutron Activation Analysis; to assess the distribution of the raw material, by both natural and cultural means; and to evaluate source preference and utilization in antiquity. Study has concentrated on the documentation and sampling of the sources, as well as secondary obsidian deposits along the Vorotan River, together with morphological, technological, and metrical analyses of the large obsidian assemblage collected in the course of survey and excavation by the project. Results indicate that the Bazenk and Satanakar sources have more than one geochemically-distinct flow, whereas all of the samples from the various Sevkar flows are indistinguishable. Analysis of artifacts from sites ranging in date from the late 5th to 1st millennium B.C. indicate an overwhelming preference for Sevkar obsidian. Heavy use of cobbles taken from the Vorotan River appears to have affected local lithic reduction strategies in significant ways.

Aluminum Content of Neonatal Parenteral Nutrition Solutions: Options for Reducing Aluminum Exposure.

Introduction: Calcium chloride (CaCl2) has been the only calcium additive available in the United States that has a low aluminum (Al) content. Calcium gluconate in glass vials (CaGluc-Gl) has a high Al content while calcium gluconate in plastic vials (CaGluc-Pl) has a low Al content. The purpose of this study was to measure Al concentrations in neonatal parenteral nutrition (PN) solutions prepared using various calcium additives. Methods: Samples of solutions compounded with CaCl2 or CaGluc-Gl and sodium phosphate (NaPhos) as well as CaGluc-Pl and sodium glycerophosphate (NaGP) with and without cysteine were analyzed for Al content. Samples of the cysteine and calcium gluconate additives were also sent for analysis. Results: Solutions containing CaCl2 and CaGlu-Pl had mean Al concentrations of 1.2–2.3 mcg/dL, while those with CaGlu-Gl had mean concentrations of 14.6–15.1 mcg/dL. Solutions made with NaGP were low in Al content. The measured Al content of 2 lots of the cysteine additive were 168 ± 23 mcg/L and 126 ± 5 mcg/L. The Al concentration equalled 2730 ± 20 mcg/L for the CaGlu-Gl additive and 310 ± 80 mcg/L for the CaGlu-Pl additive. Conclusion: The study indicates that solutions containing CaCl2 or CaGluc-Pl and NaPhos or NaGP are low in Al content. Using these options for calcium and phosphate additives can limit aluminum intake from neonatal PN to levels within the Food and Drug Administration guideline of ⩽5 mcg/kg/d.INTRODUCTION Calcium chloride (CaCl2 ) has been the only calcium additive available in the United States that has a low aluminum (Al) content. Calcium gluconate in glass vials (CaGluc-Gl) has a high Al content while calcium gluconate in plastic vials (CaGluc-Pl) has a low Al content. The purpose of this study was to measure Al concentrations in neonatal parenteral nutrition (PN) solutions prepared using various calcium additives. METHODS Samples of solutions compounded with CaCl2 or CaGluc-Gl and sodium phosphate (NaPhos) as well as CaGluc-Pl and sodium glycerophosphate (NaGP) with and without cysteine were analyzed for Al content. Samples of the cysteine and calcium gluconate additives were also sent for analysis. RESULTS Solutions containing CaCl2 and CaGlu-Pl had mean Al concentrations of 1.2-2.3 mcg/dL, while those with CaGlu-Gl had mean concentrations of 14.6-15.1 mcg/dL. Solutions made with NaGP were low in Al content. The measured Al content of 2 lots of the cysteine additive were 168 ± 23 mcg/L and 126 ± 5 mcg/L. The Al concentration equalled 2730 ± 20 mcg/L for the CaGlu-Gl additive and 310 ± 80 mcg/L for the CaGlu-Pl additive. CONCLUSION The study indicates that solutions containing CaCl2 or CaGluc-Pl and NaPhos or NaGP are low in Al content. Using these options for calcium and phosphate additives can limit aluminum intake from neonatal PN to levels within the Food and Drug Administration guideline of ≤5 mcg/kg/d.

NEUTRON ACTIVATION ANALYSIS

Neutron activation analysis has become a major analytical tool in the field of archaeology, providing sensitive trace-element analyses of artifacts and raw materials. Samples are first irradiated with the flood of neutrons generated by a nuclear reactor, creating radioactive isotopes of elements present. By monitoring the subsequent decay of these radioisotopes, it is possible to identify and precisely quantify the elements present in a broad range of artifact types. The technique is widely employed in provenance determination, where the artifact is linked to its geographic origin by matching its trace-element composition to that of raw material sources. Other applications include authentication, explorations of materials science and manufacturing technology, as well as investigations into diet and nutrition.