Submonolayer Quantum Dot Infrared Photodetector

A method has been developed for inserting submonolayer (SML) quantum dots (QDs) or SML QD stacks, instead of conventional Stranski-Krastanov (S-K) QDs, into the active region of intersubband photodetectors. A typical configuration would be InAs SML QDs embedded in thin layers of GaAs, surrounded by AlGaAs barriers. Here, the GaAs and the AlGaAs have nearly the same lattice constant, while InAs has a larger lattice constant. In QD infrared photodetector, the important quantization directions are in the plane perpendicular to the normal incidence radiation. In-plane quantization is what enables the absorption of normal incidence radiation. The height of the S-K QD controls the positions of the quantized energy levels, but is not critically important to the desired normal incidence absorption properties. The SML QD or SML QD stack configurations give more control of the structure grown, retains normal incidence absorption properties, and decreases the strain build-up to allow thicker active layers for higher quantum efficiency

Individualized therapies in colorectal cancer: KRAS as a marker for response to EGFR-targeted therapy

Individualized therapies that are tailored to a patient's genetic composition will be of tremendous value for treatment of cancer. Recently, Kirsten ras (KRAS) status has emerged as a predictor of response to epidermal growth factor receptor (EGFR) targeted therapies. In this article, we will discuss targeted therapies for colorectal cancers (CRC) based on EGFR signaling pathway and review published data about the potential usefulness of KRAS as a biological marker for response to these therapies. Results from relevant studies published since 2005 and unpublished results presented at national meetings were retrieved and summarized. These studies reflected response (or lack of response) to EGFR-targeted therapies in patients with metastatic CRC as a function of KRAS status. It has become clear that patients with colorectal cancer whose tumor has an activating mutation in KRAS do not respond to monoclonal antibody therapies targeting EGFR. It should now become a standard practice that any patients being considered for EGFR targeted therapies have their tumors tested for KRAS status and only those with wild-type KRAS being offered such therapies

Clinical significance of BRAF mutations in metastatic melanoma

Forty to eighty percent of melanoma tumors have activating mutations in BRAF although the clinical importance of these mutations is not clear. We previously reported an analysis of BRAF mutations in metastatic melanoma samples from 68 patients. In this study, we correlated patient baseline characteristics, prognostic factors, and/or clinical outcomes with the presence of BRAF mutations. No significant differences were observed in age, gender, location of primary melanoma, stage at the diagnosis, and depth of primary tumor between patients with and without BRAF mutations. Melanomas harboring BRAF mutations were more likely to metastasize to liver (P = 0.02) and to metastasize to multiple organs (P = 0.048). Neither time to progression to stage IV nor overall survival were associated with BRAF mutations. In conclusion, we observed no significant differences in clinical characteristics or outcomes between melanomas with or without BRAF mutations. Although there was an increased frequency of liver metastasis and tendency to metastasize to multiple organs in tumors with BRAF mutations, there was no detectable effect on survival. Future prospective studies should include analysis of whether BRAF mutations in melanoma tumors correlate with an increased tendency to metastasize to liver or to multiple organs

A resonant spin lifetime transistor

We present a device concept for a spintronictransistor based on the spin relaxation properties a two-dimensional electron gas(2DEG). The device design is very similar to that of the Datta and Das spin transistor. However, our proposed device works in the diffusive regime rather than in the ballistic regime. This eases lithographical and processing requirements. The switching action is achieved through the biasing of a gate contact, which controls the lifetime of spins injected into the 2DEG from a ferromagnetic emitter, thus allowing the traveling spins to be either aligned with a ferromagnetic collector or randomizing them before collection. The device configuration can easily be turned into a memory and a readout head for magnetically stored information

Neutral dinuclear copper(I)-NHC complexes : synthesis and application in the hydrosilylation of ketones

The authors gratefully acknowledge the Royal Society (University Research Fellowship to C.S.J.C.) for funding.The synthesis of a class of highly stable neutral dinuclear Cu(I)-NHC complexes using 1,2,4-triazole as a bridging ligand is described. Various NHCs were used to generate a library of [Cu(μ-trz)(NHC)]2, complexes. Interestingly, [Cu(μ-trz)(IPr)]2 was found to be highly active in the hydrosilylation of ketones, without the need for an external base or any other additive. A wide range of aryl and alkyl ketones, as well as sterically hindered ketones, was successfully reduced to alcohols using the lowest catalyst loading reported to date.PostprintPeer reviewe

Association of RENAL nephrometry score with outcomes of minimally invasive partial nephrectomy

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98294/1/iju3222.pd

The effect of Sailuotong (SLT) on neurocognitive and cardiovascular function in healthy adults: a randomised, double-blind, placebo controlled crossover pilot trial

Background: Sailuotong (SLT) is a standardised herbal medicine formula consisting of Panax ginseng, Ginkgo biloba, and Crocus sativus, and has been designed to enhance cognitive and cardiovascular function. Methods: Using a randomised, double-blind, placebo controlled crossover design, this pilot study assessed the effect of treatment for 1 week with SLT and placebo (1 week washout period) on neurocognitive and cardiovascular function in healthy adults. Sixteen adults completed a computerised neuropsychological test battery (Compass), and had their electroencephalographic (EEG) activity and cardiovascular system function assessed. Primary outcome measures were cognitive test scores and oddball task event-related potential (ERP) component amplitudes. Secondary outcome measures were resting EEG spectral band amplitudes, and cardiovascular parameters. Results: Treatment with SLT, compared to placebo, resulted in small improvements in working memory, a slight increase in auditory target (cf. nontarget) P3a amplitude, and a decrease in auditory N1 target (cf. nontarget) amplitude. There was no effect of SLT on EEG amplitude in delta, theta, alpha, or beta bands in both eyes open and eyes closed resting conditions, or on aortic and peripheral pulse pressure, and resting heartrate. Conclusions: Findings suggest that SLT has the potential to improve working memory performance in healthy adults; a larger sample size is needed to confirm this. Trial registration: Australia New Zealand Clinical Trials Registry Trial Registration Id: ACTRN12610000947000