Optical properties of ZnO nanocrystals embedded in PMMA

We report in this work the preparation of thin films of ZnO nanocrystals synthesized and dispersed in polymethylmethacrylate using a easy route and deposited in class substrate by spin coating technique. Their structural and optical properties were investigated by X-ray, absorption and photoluminescence spectroscopy. The XRD patterns exhibit sharp peaks at $2\uptheta $ corresponding to the hexagonal (wurtzite) phase diffraction planes. The optically characterization, exhibit a wide absorption band in the range of the study and a large emission band with three peaks at 481.5, 531.09 and at 671.28 nm.The crystallites radius (R) was estimated by applying the effective mass approximation model and was about 1.8 nm. From measurements of second order susceptibilities using harmonic generation technique at $\lambda = 1,064\,\text{ nm }$ in picoseconds regime we deduced $\lambda _\mathrm{eff}^{<2>}$ equal to $5.95\times 10^{-10}$  m/V. Obtained $\lambda _\mathrm{eff}^{<2>}$ was four order of magnitude larger compared with ZnO bulk material (2.5 pm/V).     

Minimal affinizations as projective objects

We prove that the specialization to q=1$q=1$ of a Kirillov–Reshetikhin module for an untwisted quantum affine algebra of classical type is projective in a suitable category. This yields a uniform character formula for the Kirillov–Reshetikhin modules. We conjecture that these results hold for specializations of minimal affinization with some restriction on the corresponding highest weight. We discuss the connection with the conjecture of Nakai and Nakanishi on q$q$-characters of minimal affinizations. We establish this conjecture in some special cases. This also leads us to conjecture an alternating sum formula for Jacobi–Trudi determinants.     

Macdonald polynomials and BGG reciprocity for current algebras

We study the category $\mathcal I _{\mathrm{gr }}$ of graded representations with finite-dimensional graded pieces for the current algebra $\mathfrak{g }\otimes \mathbf{C }[t]$ where $\mathfrak{g }$ is a simple Lie algebra. This category has many similarities with the category $\mathcal O $ of modules for $\mathfrak{g }$ , and in this paper, we prove an analog of the famous BGG duality in the case of $\mathfrak{sl }_{n+1}$ .     

On Multigraded Generalizations of Kirillov–Reshetikhin Modules

We study the category of $\mathbb Z^\ell$ -graded modules with finite-dimensional graded pieces for certain $\mathbb Z^\ell_+$ -graded Lie algebras. We also consider certain Serre subcategories with finitely many isomorphism classes of simple objects. We construct projective resolutions for the simple modules in these categories and compute the Ext groups between simple modules. We show that the projective covers of the simple modules in these Serre subcategories can be regarded as multigraded generalizations of Kirillov–Reshetikhin modules and give a recursive formula for computing their graded characters.     

Antibody–Drug Conjugates: An Emerging Concept in Cancer Therapy

Traditional cancer chemotherapy is often accompanied by systemic toxicity to the patient. Monoclonal antibodies against antigens on cancer cells offer an alternative tumor‐selective treatment approach. However, most monoclonal antibodies are not sufficiently potent to be therapeutically active on their own. Antibody–drug conjugates (ADCs) use antibodies to deliver a potent cytotoxic compound selectively to tumor cells, thus improving the therapeutic index of chemotherapeutic agents. The recent approval of two ADCs, brentuximab vedotin and ado‐trastuzumab emtansine, for cancer treatment has spurred tremendous research interest in this field. This Review touches upon the early efforts in the field, and describes how the lessons learned from the first‐generation ADCs have led to improvements in every aspect of this technology, i.e., the antibody, the cytotoxic compound, and the linker connecting them, leading to the current successes. The design of ADCs currently in clinical development, and results from mechanistic studies and preclinical and clinical evaluation are discussed. Emerging technologies that seek to further advance this exciting area of research are also discussed.     

The Restricted Kirillov–Reshetikhin Modules for the Current and Twisted Current Algebras

We define a family of graded restricted modules for the polynomial current algebra associated to a simple Lie algebra. We study the graded character of these modules and show that they are the same as the graded characters of certain Demazure modules. In particular, we see that the specialized characters are the same as those of the Kirillov Reshetikhin modules for quantum affine algebras.VC was partially supported by the NSF grant DMS-0500751.     

Novel synthesis of tetrahydro-β-carbolines and tetrahydroisoquinolines via three-component reaction using hexagonally ordered mesoporous AlSBA-15 catalysts

Tryptamine, aryl aldehyde, and benzyl chloride undergo smooth coupling using well-ordered mesoporous AlSBA-15 catalyst with hexagonal porous structure in acetonitrile at 80 °C to furnish tetrahydrocarbolines in good yields with a high selectivity. This reaction also proceeds with homoveratrylamine to give the corresponding tetrahydroisoquinolines. A variety of aryl and heteroaryl aldehydes have also been used for producing tetrahydrocarbolines in high yields. This AlSBA-15-promoted Pictet-Spengler reaction provides a mild alternative to the traditional Brönsted or Lewis acids typically employed for the preparation of tetrahydrocarbolines and tetrahydroisoquinolines.