Platinum sulfated zirconia catalysts. Fate of chlorine during activation

The gases evolved during activation of a sulfated zirconia prepared by impregnation with chloroplatinic acid have been followed using mass spectrometry and infrared spectrometry. When the sample is heated in either helium or in air, the halogen is lost from the catalyst as HCl and Cl2. Heating the sample in hydrogen results in the loss of the halogen as HCl, and only traces as Cl2. The loss of halogen occurs over a wide temperature range (200-900°C). The data are consistent with the chloroplatinic acid being converted by loss of halide with the formation of Pt⁰. This revised version was published online in July 2006 with corrections to the Cover Date.     

Flavonoid composition of lemon-yellow sorghum genotypes

Flavonoid composition of lemon-yellow sorghums grown in two locations in Texas, USA was evaluated and compared with that of white and red sorghums using high performance liquid chromatography (HPLC-PDA). Sorghums from Lubbock were brighter in colour and had minimal weathering compared to those from College Station. Sorghums with red/purple secondary plant colour had the highest levels of 3-deoxyanthocyanidins (8–187 μg/g) and their levels were highest in grains from College Station (39–187 μg/g). Pericarp colour did not have any effect on 3-deoxyanthocyanidin levels (p > 0.05). The tan plant lemon-yellow sorghum Tx2953 had the highest levels of flavones (268–362 μg/g). Among the genotypes, lemon-yellow sorghums had the highest levels of flavanones (134–1780 μg/g), which are located in the pericarp and their levels were increased in the grains with a bright yellow pericarp and minimal weathering. The high flavanone levels in lemon-yellow sorghums makes this sorghum genotype a good source of those compounds.     

Recent developments in controlling the architecture for property optimization in Al-based materials

In Al materials the evolution of new material architectures involves new processing techniques to refine and control critical length scales in the structure. New casting technology is changing the capability of clad products; high shear processes are being developed to produce ultra-fine grained alloys and new composite materials providing property enhancements not available in conventional alloys.     

In situ polymerization of polyamide 66 nanocomposites utilizing interfacial polycondensation. II. Sodium montmorillonite nanocomposites

Interfacial polycondensation (IPC) is used to generate polyamide 66 (PA66) nanocomposite using sodium montmorillonite (NaMMT), which offers better thermal stability than organically modified montmorillonite. Several approaches are used to obtain different levels of dispersion for studying the factors affecting dispersion of NaMMT layered‐silicates. These approaches include dispersing NaMMT in either aqueous media or in a compatible nonaqueous medium. Moreover, clay slurry was added to the reaction media separately or in combination with the aqueous hexamethylenediamine solution, which includes either excess amine or sodium carbonate as the by‐product scavenger, in order to study the effect of sequencing on the dispersion of NaMMT. Several characterization techniques including dynamic mechanical analysis, wide angle X‐ray diffraction, and transmission electron microscopy are used to examine the structure and relate it to the mechanical properties of the nanocomposites. Results show that in situ polymerization techniques predominantly give rise to hybrid exfoliated–intercalated NaMMT structure. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

Hero/heroine modeling for Puerto Rican adolescents: A preventive mental health intervention.

Culturally sensitive treatments of the special mental health needs of high-risk Puerto Rican adolescents are lacking. The hero/heroine intervention was based on adult Puerto Rican role models to foster ethnic identity, self-concept, and adaptive coping behavior. 90 nonclinical Puerto Rican 8th and 9th graders were screened for presenting behavior problems in school and randomly assigned to an intervention and a control group. After 19 sessions, the intervention significantly increased adolescents' ethnic identity and self-concept and reduced anxiety. Treatment outcomes varied as a function of grade level, sex, and household composition. Self-concept was negatively affected among girls from intact families. The study supports the effectiveness of the culturally sensitive modality as a preventive mental health intervention for high-risk Puerto Rican adolescents, especially from single-parent families. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Computerised biofeedback games: a new method for teaching stress management and its use in irritable bowel syndrome

OBJECTIVE: To examine the characteristics of foreign-born people with tuberculosis (TB) in Southern Florida, their contribution to the total number of TB cases, and available data on their HIV status as well as to determine the number of cases detected by the overseas medical screening of immigrants and refugees. METHODS: The authors reviewed TB cases reported by Broward, Dade, and Palm Beach counties in 1995. Case records were matched against the CDC Division of Quarantine database of immigrants and refugees suspected to have TB at the time of visa application overseas. RESULTS: Nearly half (49%) of TB cases in the three counties were among people born outside the United States--34% in Broward County, 58% in Dade County, and 40% in Palm Beach County. A high percentage (26%) were co-infected with HIV. Of those with known date of arrival, 68% had been in the United States for five or more years. Only three cases had been identified by overseas immigrant screening. CONCLUSIONS: A low percentage of TB cases in foreign-born people were identified through the overseas screening system. Controlling TB in South Florida will require efforts targeted toward high risk populations, including people with HIV infection.     

Tubulin Photoaffinity Labeling with Biotin‐Tagged Derivatives of Potent Diketopiperazine Antimicrotubule Agents

NPI‐2358 ( 1 ) is a potent antimicrotubule agent that was developed from a natural diketopiperazine, phenylahistin, which is currently in Phase I clinical trials as an anticancer drug. To understand the precise recognition mechanism of tubulin by this agent, we focused on its potent derivative, KPU‐244 ( 2 ), which has been modified with a photoreactive benzophenone structure, and biotin‐tagged KPU‐244 derivatives ( 3 and 4 ), which were designed and synthesized for tubulin photoaffinity labeling. Introduction of the biotin structure at the p′‐position of the benzophenone ring in 2 exhibited reduced, but significant biological activities with tubulin binding, tubulin depolymerization and cytotoxicity in comparison to the parent KPU‐244. Therefore, tubulin photoaffinity labeling studies of biotin‐derivatives 3 and 4 were performed by using Western blotting analysis after photoirradiation with 365 nm UV light. The results indicated that tubulin was covalently labeled by these biotin‐tagged photoprobes. The labeling of compound 4 was competitively inhibited by the addition of diketopiperazine 1 or colchicine, and weakly inhibited by the addition of vinblastine. The results suggest that photoaffinity probe 4 specifically recognizes tubulin at the same binding site as anticancer drug candidate 1 , and this leads to the disruption of microtubules. Probe 4 serves well as a useful chemical probe for potent antimicrotubule diketopiperazines, much like phenylahistin, and it also competes for the colchicine‐binding site.     

Oxidative Instability of Fuels: Nickel Catalyzed Reactions

The reactions that lead to long-term storage instability of fuels are not fully understood. Various reports in the literature link particular fuels with specific reactions, usually oxidation or free radical processes. Trace quantities of metals are present in all processed fuels. The metal source can be naturally occurring or present from fuel handling. The usual case is to look at the reaction of the metal or metal ion with molecular oxygen or other active oxygen species such as hydroperoxides. This article reports on the reaction of a nitrogen heterocycle, indole. We propose a mechanism that shows that catalytic amounts of nickel can produce compounds of higher molecular weight and increased polarity.