The seeds of various plants were used as weights because their mass reputedly varies so little. Carob (Ceratonia siliqua), which has given its name to the carat, is particularly famous in this regard. But are carob seeds unusually constant in weight and, if not, how did the myth arise? The variability of seeds sampled from a collection of carob trees (CV=23%) was close to the average of 63 spec...

Since the discovery of C(60) fullerene, considerable efforts have been devoted to find other elements with similar hollow cage structures. However, search for hollow metallic cages with a diameter similar to that of C(60) fullerene has been elusive. We describe a procedure for the rational design of metallic cages by suitably choosing their size, composition, and charge state. A 22 karat nanogo...

s The purpose of this study was carried out by the embryotoxicity risk assessment of the dental alloys containing indium. We produced Ag-In alloy, Ag-Pd-Au-Cu alloy and gold alloy for porcelain bonding. For the extraction of these alloy components into the ES-D3 cell culture medium, each alloy was reduced to a powder using a diamond point and sterilized after rinsing. In order to facilitate the...

Gold alloys with Cu contents of 10 mass%, 20%, and 30% were used for morphological observation of porous surface structures after heating at 800 degrees C in air followed by pickling with acid solution. With increasing Cu content in the gold alloy, the internal oxidation zone became well-developed in the alloy matrix. The mechanism by which a porous structure was formed on the surface of a gold...

Low gold-content dental alloys nowadays represent viable alternatives to high nobility alloys. The casting techniques and equipment used for low-gold content alloys are similar to those used for conventional gold alloys. This, coupled with their acceptable properties, good clinical performance and lower cost, has lead to their widespread use. The alloy performance in the dental laboratory is an...

This study presents the results of a long-term clinical evaluation of conical crown-retained dentures fabricated using different technologies. Four different material connections between the outer and inner crowns were used: cast gold/cast gold, cast gold/electroforming, nonprecious alloy/electroforming, and titanium abutment/electroforming. Technical failures and retention values were assessed...

This study evaluated the influence of water storage conditions and the effect of metal priming agents on bond strength and durability of four luting agents joined to gold alloy. Disk specimens were cast from a gold alloy (Degudent U), and the surfaces were ground flat with abrasive paper. Three surface conditions employed were: unprimed, primed with Alloy Primer, and primed with Metaltite. Thre...

background and aim: an important criterion for success assessment of implant-supported prostheses is marginal fit. vertical and horizontal discrepancy can result in loosening of the prosthetic screw, crestal bone resorption, peri-implantitis and loss of osseointegration. despite careful attention to waxing, investing, and casting, marginal discrepancies are inevitable. the aim of this study was...

objective(s):   metal nanoparticles (nps) offer a wide variety of potential applications in pharmaceutical sciences due to the unique advances in nanotechnology research. in this work, bimetal ag-au alloy nps were prepared and their combinations with other antibiotics were tested against staphylococcus aureus.   materials and methods: firstly, ag-au alloy nps with au/ag molar ratio of 1:1 was f...