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The December 2011 release of a draft United States Food and Drug Administration (FDA) guidance concerning regulatory classification of pharmaceutical cocrystals of active pharmaceutical ingredients (APIs) addressed two matters of topical interest to the crystal engineering and pharmaceutical science communities: (1) a proposed definition of cocrystals; (2) a proposed classification of pharmaceutical cocrystals as dissociable “API-excipient” molecular complexes. The Indo–U.S. Bilateral Meeting sponsored by the Indo–U.S. Science and Technology Forum titled The Evolving Role of Solid State Chemistry in Pharmaceutical Sciencewas held in Manesar near Delhi, India, from February 2–4, 2012. A session of the meeting was devoted to discussion of the FDA guidance draft. The debate generated strong consensus on the need to define cocrystals more broadly and to classify them like salts. It was also concluded that the diversity of API crystal forms makes it difficult to classify solid forms into three categories that are mutually exclusive. This perspective summarizes the discussion in the Indo–U.S. Bilateral Meeting and includes contributions from researchers who were not participants in the meeting. [ABSTRACT FROM AUTHOR]

At the Montana State University Avalanche Research Site, instrumentation has been installed to measure temperatures, flow depth, and velocities during an avalanche. Five thermocouples have been installed along a 30-m section of the avalanche running surface. Temperature time histories were collected during several avalanches at the flow running surface. The flowing snow at the running surface did show a temperature increase as it progressed down the slope, but did not frequently approach the melt temperature. Snow samples were collected before the tests in the release zone and after the avalanches in the debris for microstructural comparison. A computed tomography (CT) X-ray scanner was used to obtain images of the microstructural details of the pretest and debris snow samples. Using the microstructural parameters from the CT images, the growth of the new bonds in the debris was analyzed using a vapor diffusion sintering model. New bonds were shown to grow rapidly at the expense of small high-energy structures that resulted from the avalanche. The analysis showed vapor movement and sintering of new bonds due to surface curvature differences may be a significant debris bonding mechanism in snow that does not approach melt temperatures during an avalanche. [Copyright &y& Elsevier]

Examines the timing and physical conditions of quartz growth in porphyry copper deposits in Butte, Montana. Texture of quartz; Analysis of the quartz-molybdenite vein formations; Role of pressure fluctuations in quartz formation.

Presents a study that determined whether vibrations with frequencies in the sonic to ultrasonic range have any effect on the crystallization of Virginia Highlands basalt from Mole Hill, Virginia. Comparison of plagioclase crystals; Determination of status of chemical equilibrium using electron microprobe analysis; Quantification of observed differences.

Examines the crustal growth in Southern Arizona. Application of uranium-lead analyses; Delineation of the suture zone between the Pinal tectonostratigraphic unit; Characteristics of the suture location.

Examination with scanning electron microscopy (SEM) and scanning force microscopy (SFM) revealed etch pits, layers and islands on dolomite crystal faces synthesized from calcite in Ca-Mg-Cl solutions at 200 °C and a wide variety of natural dolomites. Layers are broad, flat structures bounded by steps less than 100 nm high and greater than 1 μm wide. Islands are rounded topographic highs <20 nm high and <200 nm wide. The nanotopography of synthetic dolomite changed from islands throughout most of the reaction to layers at 100% dolomite. Island nanotopography formed on both Ca-rich and near-stoichiometric dolomite. Analyses of reaction products from dolomite synthesis indicates that there are no SFM-detectable products formed in <10 h. SEM-detectable products formed in 15 h. X-ray diffraction (XRD)-detectable products formed in ≈18 h, and the reaction went to completion in ≈40 h. Based on SFM analyses, the induction period for dolomitization in these experiments accounts for ≈20% of the total reaction time necessary to dolomitize CaCO3 completely under the experimental conditions used here. Island nano- topography is inferred to occur at higher degrees of supersaturation than layer nanotopography for three reasons. First, island nanotopography on synthetic calcite and gypsum forms at higher supersaturations than layer nanotopography. Secondly, island nanotopography formed in solutions with higher degrees of supersaturation with respect to dolomite. Thirdly, the greater surface roughness of a crystal face composed of islands compared with layers indicates that island surfaces have higher surface energy than layer surfaces. Therefore, the stability of island surfaces requires a higher degree of supersaturation. Because islands and layers form under a wide range of conditions, their presence provides broadly applicable criteria for evaluating relative degrees of supersaturation under which ancient dolomite formed. Comparison of synthetic dolomites with natural dolomites demonstrates (1) similar nanotopography on natural and synthetic dolomites and (2) both natural planar and non-planar dolomite may have island nanotopography. [ABSTRACT FROM AUTHOR]

An Indo−U.S. bilateral meeting on Pharmaceutical Cocrystals and Polymorphs was jointly sponsored by the Indo−U.S. Science and Technology Forum (IUSSTF) and the U.S. National Science Foundation. This workshop meeting was held in the historic Mysore city, located about 150 km from Bangalore, on February 8−10, 2009. The American and Indian delegations included editors of Crystal Growth & Design. [ABSTRACT FROM AUTHOR]

The article discusses the lack of crystal growing for use in physics measurements and condensed matter experiments in the U.S. Loren Pfeiffer, a technician at Bell Labs, was the only U.S. source of semiconductor crystals for experiments. Labs in Japan have created divisions for crystal growing. The U.S. Department of Energy (DOE) sponsored a workshop on crystal growth. A study by the U.S. National Academy of Sciences will evaluate national crystal growth.

Presents scientific research studies in the United States. Influence of the interaction between rod-like molecules on nematic liquid crystals; Crystallization of iron due to the cooling of the earth; Involvement of proteins in controlling the polarized distribution of actin filaments.

Discusses the developments in the field of nanotechnology in the United States. Research groups that sought to control the pattern of crystal growth on surfaces; Use of self-assembling monolayers of molecules with charged or polar functionalities by researchers at Harvard University; Molecular recognition between surface imprints and proteins explored by research teams from the University of Washington.

The article explores the first fifty years of integrated circuits technology in the U.S. It states that it was marked with the introduction of new concepts and advanced technologies that were developed for silicon crystal growth and several other industrial applications. The author states that it was not until 1983 that chemical mechanical polishing (CMP) developed into chemical mechanical planarization.

This article focuses on a paper published by researcher Iain McCulloch, a polymer chemist at Merck KGaA, and his colleagues in the journal "Nature Materials," about plastic-based transistors that can ferry electrical charges at nearly the same speed as amorphous silicon. The speed boost could finally help plastic electronics take advantage of their other selling points. Chief among these is their ease of fabrication. Unlike amorphous silicon, which must be grown in a vacuum chamber, plastics can be laid down from solution. That opens the door to patterning huge arrays of devices with what amounts to an ink-jet printer or other simple and cheap technologies. Plastic electronics researchers have been doing just that for over a decade. But when researchers first started laying down plastic conductors and semiconductors from solution in the early 1990s, the molecules in their films formed a jumble, like straw strewn on the ground. McCulloch and his colleagues at the Palo Alto Research Center in California and Stanford decided to remove some of the speed bumps by growing larger crystals. They started with regioregular polythiophenes and fused a pair of neighboring rings at regular intervals along the polymer backbone.

Discusses the development of a method to control the growth of crystals by graduate students of University of California in Berkeley. Use of two surface surfactants with similar non-polar pairs; Mechanics of making cadmium-selenium teardrops; Rods; Four-armed tetrapods.