Effect of ionic liquid impurities on the synthesis of silver nanoparticles.

Imidazolium-based ionic liquids have been widely utilized as versatile solvents for metal nanoparticle synthesis; however, reactions to synthesize silver nanoparticles that are performed identically in different commercially obtained lots of 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM-BF(4)) give divergent results. This suggests that impurities in these nominally identical solvents play an important role in the resulting silver nanoparticle quality. To test the effect that impurities have on the quality of silver nanoparticles synthesized in BMIM-BF(4), silver nanoparticles were synthesized in carefully prepared and purified BMIM-BF(4) and compared against silver nanoparticles that were synthesized in the purified BMIM-BF(4) that had been spiked with trace amounts of water, chloride, and 1-methylimidazole. It was clearly demonstrated that trace amounts of these common ionic liquid impurities cause significant deviation in size and shape (creating polydisperse and irregularly shaped ensembles of both large and small particles), and also negatively impact the stabilization of the resulting silver nanoparticles.

Two-phase microfluidic droplet flows of ionic liquids for the synthesis of gold and silver nanoparticles.

Droplet-based microfluidic platforms have the potential to provide superior control over mixing as compared to traditional batch reactions. Ionic liquids have advantageous properties for metal nanoparticle synthesis as a result of their low interfacial tension and complexing ability; however, droplet formation of ionic liquids within microfluidic channels in a two-phase system has not yet been attained because of their complex interfacial properties and high viscosities. Here, breakup of an imidazolium-based ionic liquid into droplets in a simple two-phase system has for the first time been achieved and characterized by using a microchannel modified with a thin film fluoropolymer. This microfluidic/ionic liquid droplet system was used to produce small, spherical gold (4.28 ± 0.84 nm) and silver (3.73 ± 0.77 nm) nanoparticles.

Flow-focused synthesis of monodisperse gold nanoparticles using ionic liquids on a microfluidic platform.

A microfluidic device was used in tandem with an imidazolium-based ionic liquid to fabricate monodisperse gold nanoparticles (4.38 ± 0.53 nm) with excellent control over size and morphology.

Heterogeneous fullerene-supported osmium tetroxide catalyst for the cis-dihydroxylation of olefins.

We report on the activity of fullerene-supported OsO(4) catalysts in the achiral dihydroxylation of olefins using N-methylmorpholine N-oxide as co-oxidant. The fullerene-supported OsO(4) catalysts can selectively dihydroxylate olefins with conversions up to 95% after 48 h without leaching, and the catalysts can be recovered and recycled several times.

Motor proficiency relationships among siblings.

The purpose of this study was to examine motor proficiency relations of siblings. 23 sibling pairs ages 5 to 13 years were studied. Motor proficiency was assessed by the Bruininks-Oseretsky Test of Motor Proficiency-Short Form of 14 items, adjusting for Body Mass Index percentile, age, and sex. The association among siblings' overall motor proficiency was not statistically significant. When each of the 14 items in the test was examined separately, significant associations were found. Items positively associated among siblings included walking on a balance beam, tapping feet and making circles, and sorting shape cards. Copying a picture of overlapping pencils and making dots in circles were inversely related. The results indicate that siblings may share certain motor-skill components of balance, bilateral coordination, and upper limb speed or dexterity, but do not necessarily have the same global motor competence. Additional research is needed to explain relations in motor skills among siblings.

A phase I/II trial of 125I methylene blue for one-stage sentinel lymph node biopsy.

BACKGROUND: Sentinel lymph node biopsy can be associated with delays in operating room schedule and with significant pain during the preoperative Tc colloid injection. To avoid these problems, we developed a novel radiolabeled blue dye that can be injected intraoperatively. METHODS: We performed a phase I/II trial (IND#70627) of sterile pyrogen-free I-methylene blue to identify sentinel nodes in patients with breast cancer. Twelve women were studied. Two women each were given peritumoral or circumareolar injections of 100, 200, 300, 400, 500, or 1000 microCi of I methylene blue. RESULTS: Sentinel nodes were detected in 11 of 12 patients, with a low-dose 200 microCi patient being the single exception. The number of sentinel nodes detected per patient ranged from 0 to 3 (mean = 1.66 nodes/case). Radioactivity at the tumor injection site [counts per second (cps) averaged over 10 seconds] ranged from 3346 to 47,300 cps and was highly dose-dependent (r = 0.90, P = 0.0002). In contrast, the in vivo node counts ranged from 0 to 1228 cps, while ex vivo counts ranged from 0 to 1516 cps. The in vivo nodal counts were dose-dependent (r = 0.67, and P = 0.0231). Radiation was carefully monitored inside the operating room and in pathology. Even with the 1-mCi dose, the radioactive blue dye produced significantly lower personnel exposure than historically seen with Tc. CONCLUSIONS: This method eliminates the painful preoperative injections of Tc colloid, is performed by the surgeon in the operating room, is associated with lower radiation exposures for personnel, and avoids the delays caused by nonoperating room personnel. These observations warrant a more extensive trial of this method using the 1000-microCi dose of I methylene blue dye for sentinel lymph node biopsies.

Tamoxifen use in patients with ductal carcinoma in situ and T1a/b N0 invasive carcinoma.

BACKGROUND: The purpose of this study was to determine how often patients with ductal carcinoma in situ and T1a/b N0 cancer are offered and accept tamoxifen for secondary chemoprevention. STUDY DESIGN: A retrospective review of 284 patients with T1a/b N0 invasive cancer treated between February 1995 and December 2001 and 129 patients with DCIS treated after September 1998 was carried out. Patient and tumor characteristics associated with being offered and accepting tamoxifen were compared. RESULTS: Tamoxifen was offered to 67% of the invasive cancer patients and accepted by 76% (51% of the entire group). Hormone receptor status was the only significant predictor of being offered tamoxifen (p = 0.004). Older age (p = 0.04), Caucasian race (p = 0.01), and parity (p = 0.04) in premenopausal women were significant predictors of tamoxifen acceptance on univariate analysis. After the publication of the National Surgical Adjuvant Breast and Bowel Project P-1 trial, significantly more patients were offered tamoxifen (p = 0.02), but acceptance rates did not change. Tamoxifen was offered to 91% of the ductal carcinoma in situ patients and accepted by 73% (67% overall). Lumpectomy was associated with significantly higher rates of being offered (p = 0.02) and accepting tamoxifen (p = 0.002) on univariate analysis. CONCLUSIONS: Factors associated with tamoxifen risks and benefits correlate poorly with the use of the drug.