Fourier-method beam analysis for coherent vertical cavity surface emitting laser arrays.

Effective engineering and exploitation of coherently coupled vertical cavity surface emitting laser arrays will benefit from simple and fast characterization of the optical coupling and coherence. We propose a Fourier method of analyzing beam profiles as an alternative to the prior beam visibility analysis and show that the mode suppression ratio and phase between a pair of supermodes can be extracted. Our analysis enables fast quantitative determination of the array coherence and supermode characteristics.

A review of canakinumab and its therapeutic potential for non-small cell lung cancer.

Inflammation is essential for our innate and adaptive immunity, but chronic inflammation can also be detrimental, playing a role in tumor development and subversion of host immunity. A multitude of proteins and cytokines are involved in chronic inflammation; interleukin-1β, in particular, has been recognized as a critical pro-inflammatory cytokine that can trigger a cascade of inflammatory mediators, promoting angiogenesis, tumor invasiveness, and metastasis. The inhibition of interleukin-1β with the antibody canakinumab was recently highlighted in a large-scale trial studying the effects of the inflammatory modulating antibody in heart disease.

Deep learning using tumor HLA peptide mass spectrometry datasets improves neoantigen identification.

Neoantigens, which are expressed on tumor cells, are one of the main targets of an effective antitumor T-cell response. Cancer immunotherapies to target neoantigens are of growing interest and are in early human trials, but methods to identify neoantigens either require invasive or difficult-to-obtain clinical specimens, require the screening of hundreds to thousands of synthetic peptides or tandem minigenes, or are only relevant to specific human leukocyte antigen (HLA) alleles. We apply deep learning to a large (N = 74 patients) HLA peptide and genomic dataset from various human tumors to create a computational model of antigen presentation for neoantigen prediction.

Product review on the Anti-PD-L1 antibody atezolizumab.

Immunotherapy as a therapeutic strategy has seized the narrative throughout clinical oncology over the past few years. Once considered a niche treatment for rare cancers, immunotherapy has quickly emerged as the standard of care for many common cancer types. The remarkable rise is largely due to the development of novel checkpoint inhibitors, specifically, antibodies targeting PD-1 and PD-L1.

Nucleophilic (Radio)Fluorination of α-Diazocarbonyl Compounds Enabled by Copper-Catalyzed H-F Insertion.

The copper-catalyzed H-F insertion into α-diazocarbonyl compounds is described using potassium fluoride (KF) and hexafluoroisopropanol. Access to complex α-fluorocarbonyl derivatives is achieved under mild conditions, and the method is readily adapted to radiofluorination with [(18)F]KF. This late-stage strategy provides an attractive route to (18)F-labeled biomolecules.

Molecular and biogeochemical evidence for methane cycling beneath the western margin of the Greenland Ice Sheet.

Microbial processes that mineralize organic carbon and enhance solute production at the bed of polar ice sheets could be of a magnitude sufficient to affect global elemental cycles. To investigate the biogeochemistry of a polar subglacial microbial ecosystem, we analyzed water discharged during the summer of 2012 and 2013 from Russell Glacier, a land-terminating outlet glacier at the western margin of the Greenland Ice Sheet. The molecular data implied that the most abundant and active component of the subglacial microbial community at these marginal locations were bacteria within the order Methylococcales (59-100% of reverse transcribed (RT)-rRNA sequences).

Diversity and potential sources of microbiota associated with snow on western portions of the Greenland Ice Sheet.

Snow overlays the majority of the Greenland Ice Sheet (GrIS). However, there is very little information available on the microbiological assemblages that are associated with this vast and climate-sensitive landscape. In this study, the structure and diversity of snow microbial assemblages from two regions of the western GrIS ice margin were investigated through the sequencing of small subunit ribosomal RNA genes.

Substrate-directable electron transfer reactions. Dramatic rate enhancement in the chemoselective reduction of cyclic esters using SmI2-H2O: mechanism, scope, and synthetic utility.

Substrate-directable reactions play a pivotal role in organic synthesis, but are uncommon in reactions proceeding via radical mechanisms. Herein, we provide experimental evidence showing dramatic rate acceleration in the Sm(II)-mediated reduction of cyclic esters that is enabled by transient chelation between a directing group and the lanthanide center. This process allows unprecedented chemoselectivity in the reduction of cyclic esters using SmI2-H2O and for the first time proceeds with a broad substrate scope.

Demonstration of enhanced side-mode suppression in metal-filled photonic crystal vertical cavity lasers.

Previously reported simulations have suggested that depositing thin layers of metal over the surface of a single-mode, etched air hole photonic crystal (PhC) vertical-cavity surface-emitting laser (VCSEL) could potentially improve the laser's side-mode suppression ratio by introducing additional losses to the higher-order modes. This work demonstrates the concept by presenting the results of a 30 nm thin film of Cr deposited on the surface of an implant-confined PhC VCSEL. Both experimental measurements and simulation results are in agreement showing that the single-mode operation is improved at the same injection current ratio relative to threshold.

Preparation and use of samarium diiodide (SmI(2)) in organic synthesis: the mechanistic role of HMPA and Ni(II) salts in the samarium Barbier reaction.

Although initially considered an esoteric reagent, SmI(2) has become a common tool for synthetic organic chemists. SmI(2) is generated through the addition of molecular iodine to samarium metal in THF.(1,2-3) It is a mild and selective single electron reductant and its versatility is a result of its ability to initiate a wide range of reductions including C-C bond-forming and cascade or sequential reactions.

Study on the coupling of acyclic esters with alkenes--the synthesis of 2-(2-hydroxyalkyl)cyclopropanols via cascade cyclization using allylsamarium bromide.

The radical cyclization between aliphatic acyclic esters and alkenes was achieved unprecedentedly in the presence of allylsamarium bromide with HMPA and H(2)O as additives. The cascade radical cyclization-ring-opening-anionic cyclization allowed facile and efficient access to 2-(2-hydroxyalkyl)cyclopropanols from readily available materials.

Effect of crown ethers on the ground and excited state reactivity of samarium diiodide in acetonitrile.

Electron transfer from the ground and excited states of Sm[15-crown-5](2)I(2) complex to a series of electron acceptors (benzaldehyde, acetophenone, benzophenone, nitrobenzene, benzyl bromide, benzyl chloride, 1-iodohexane, and 1,4-dinitrobenzene) was investigated in acetonitrile. Electron transfer from the ground state of the Sm(II)-crown system to aldehydes and ketones has a significant inner sphere component indicating that the oxophilic nature of Sm(II) prevails in the system even in the presence of bulky ligands such as 15-crown-5 ether. Activation parameters for the ground state electron transfer were determined, and the values were consistent with the proposed mechanistic models.

Unusual strategies for using indium gallium nitride grown on silicon (111) for solid-state lighting.

Properties that can now be achieved with advanced, blue indium gallium nitride light emitting diodes (LEDs) lead to their potential as replacements for existing infrastructure in general illumination, with important implications for efficient use of energy. Further advances in this technology will benefit from reexamination of the modes for incorporating this materials technology into lighting modules that manage light conversion, extraction, and distribution, in ways that minimize adverse thermal effects associated with operation, with packages that exploit the unique aspects of these light sources. We present here ideas in anisotropic etching, microscale device assembly/integration, and module configuration that address these challenges in unconventional ways.

Catalytic Ni(II) in reactions of SmI2: Sm(II)- or Ni(0)-based chemistry?

The addition of catalytic amounts of Ni(II) salts provide enhanced reactivity and selectivity in numerous reactions of SmI(2), but the mechanistic basis for their effect is unknown. We report spectroscopic and kinetic studies on the mechanistic role of catalytic Ni(II) in the samarium Barbier reaction. The mechanistic studies presented herein show that the samarium Barbier reaction containing catalytic amounts of Ni(II) salts is driven solely by the reduction of Ni(II) to Ni(0) in a rate-limiting step.

Uncovering the mechanistic role of HMPA in the samarium Barbier reaction.

The presence of HMPA is critical for the selective coupling of alkyl halides and ketones by SmI2. Although previous rate studies have shown that HMPA dramatically accelerates the reduction of alkyl halides over ketones, the basis of this rate acceleration is unknown. In this communication, we report experimental and computational evidence that demonstrate that the selectivity observed in the samarium Barbier reaction is in part a result of activation of the alkyl halide bond by HMPA.

Stochastic coupled mode theory for partially coherent laser arrays.

Partially coherent, transversely coupled laser arrays are investigated within a stochastic coupled mode formalism. Predictions of the coherence or correlation functions in both the spectral and time domains are made. It is demonstrated that the coherence properties of the system in both domains are strongly dependent on the number and intensity of coupled modes.

Printed assemblies of inorganic light-emitting diodes for deformable and semitransparent displays.

We have developed methods for creating microscale inorganic light-emitting diodes (LEDs) and for assembling and interconnecting them into unusual display and lighting systems. The LEDs use specialized epitaxial semiconductor layers that allow delineation and release of large collections of ultrathin devices. Diverse shapes are possible, with dimensions from micrometers to millimeters, in either flat or "wavy" configurations.

Partial coherence in coupled photonic crystal vertical cavity laser arrays.

A classical, stochastic, coupled-oscillator model for the emergence of partial coherence in arrays of vertical cavity surface emitting lasers is presented. The spectra of the uncoupled lasers determine the second order coherence properties of the coupled system. Predictions of the resultant radiation and interference patterns are verified experimentally.

Optical properties of photonic crystal heterostructure cavity lasers.

We design, fabricate, and test photonic crystal heterostructure cavity lasers in the InP material system. A heterostructure cavity is formed by interfacing two different photonic crystals such that a dispersion maximum of the inner lattice lies within the band gap of the surrounding lattice. Feedback to slow light modes of the central region results in a lower threshold and single mode operation.

Two-dimensional integration of a vertical-cavity surface-emitting laser and photodetectors for position sensing.

Noncontact long-range position sensing is desirable for a number of applications. We have designed and fabricated a monolithically integrated vertical-cavity surface-emitting laser (VCSEL) and p-type/intrinsic/n-type (PIN) photodetectors for optical position sensing. Calculations using the reflection from a periodic metallic corrugation as a position gauge indicate resolution in the submicron regime.

Optical AND/OR gates based on monolithically integrated vertical cavity laser with depleted optical thyristor structure.

Latching optical switches and optical logic gates with AND and OR functionality are demonstrated for the first time by the monolithic integration of a vertical cavity lasers with depleted optical thyristor structure. The thyristors have a low threshold current of 0.65 mA and a high on/off contrast ratio of more than 50 dB.

Automatic detection and notification of "wrong patient-wrong location'' errors in the operating room.

When procedures and processes to assure patient location based on human performance do not work as expected, patients are brought incrementally closer to a possible "wrong patient-wrong procedure'' error. We developed a system for automated patient location monitoring and management. Real-time data from an active infrared/radio frequency identification tracking system provides patient location data that are robust and can be compared with an "expected process'' model to automatically flag wrong-location events as soon as they occur.

Effects of a high-selenium yeast supplement on celecoxib plasma levels: a randomized phase II trial.

A combination of celecoxib and selenium was used in a randomized double-blind Phase II trial as a preliminary study to a multicenter Phase III colorectal cancer chemoprevention trial using these two agents together. The purpose of this trial was to determine whether high-selenium baker's yeast [(Saccharomyces cerevisiae) 200 microg once daily] in combination with celecoxib (400 mg once daily) altered the steady-state plasma concentration of celecoxib or produced clinically significant toxicities. Seventy-three healthy subjects (ages 40-75 years) were recruited to the 6-week study from the general local population and were randomized to either the celecoxib plus selenized baker's yeast group or the celecoxib plus placebo group after a 2-week run in period of celecoxib only.

Couples relapse prevention sessions after behavioral marital therapy for male alcoholics: outcomes during the three years after starting treatment.

Objective: This article provides a complete report of outcome data from a study of behavioral marital therapy (BMT) with and without additional couples relapse prevention (RP) sessions. (See J. Stud.