Pushing Nonlinear Optical Oxides into the Mid-Infrared Spectral Region Beyond 10 pm: Design, Synthesis, and Characterization of La3SnGa5O14
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
Authors: Lan, Haichao; Liang, Fei; Jiang, Xingxing; Zhang, Cong; Yu, Haohai; Lin, Zheshuai; Zhang, Huaijin; Wang, Jiyang; Wu, Yicheng
Abstract
Mid-infrared (mid-IR) coherent light is crucial for several applications in science as well as daily life, and its development especially in powerful augmentation is constrained by the availability of nonlinear optical (NLO) materials. The development of useful mid-IR NLO materials is limited by the requirements of a wide mid-IR transparent window, high laser damaged threshold (LDT), and strong NLO effect. It is common knowledge that oxides are not suitable mid-IR NLO materials, as their IR absorption cutoff wavelengths are usually <6 mu m; however, their LDTs and NLO effects can be large. Herein, we focused on langasite oxides and built structure-composition-property maps that describe the NLO properties in these materials by combining computational property prediction and experimental characterization. Accordingly, rational molecular design was performed, a new member of the langasite family, La3SnGa5O14 (LGSn), was synthesized, and single crystals were grown. The produced material exhibits the widest transparent region (0.27-11.0 pm) among available oxides, the largest LDT (846 MW/cm(2)) among materials that are transparent to 10 pm, and the strongest SHG effect among langasites. The discovery of LGSn facilitates the application of oxides as NLO crystals in the mid-IR spectral region beyond 10 mu m. More generally, the developed strategy could be used to guide and accelerate the systematic discovery of functional materials through understanding the key structure composition -property relationships using the predictive power of computational tools.
Construction of retroviral vectors carrying human CD3 gamma cDNA and reconstitution of CD3 gamma expression and T cell receptor surface expression and function in a CD3 gamma-deficient mutant T cell line
HUMAN GENE THERAPY
Authors: Sun, JY; PachecoCastro, A; Borroto, A; Alarcon, B; AlvarezZapata, D; Regueiro, JR
Abstract
CD3 gamma, a subunit of the T cell receptor-CD3 (TCR/CD3) complex, helps to support surface TCR/CD3 expression and participates in signal transduction for gene induction after antigen recognition by T lymphocytes, and in TCR/CD3 down-modulation. Humans with primary immunodeficiencies caused by inherited mutations in the CD3 gamma gene or in the gene encoding CD3 epsilon, another subunit of TCR/CD3 complex, have been previously reported. To develop a gene therapy protocol for CD3-deficient patients, CD3 gamma cDNA was orientationally inserted into two retroviral vectors (LNCX and LXSN), which resulted in recombinant vectors LNCG and LGSN, respectively. Two vector producer cell lines Am12/LNCG and Am12/LGSN were established from packaging cells GP+envAm12. Their mean viral titers were 6.5 x 10(6) and 2.0 x 10(7) cfu/ml, respectively, as shown by an improved retroviral vector production and transduction method that increases titers around five-fold over conventional methods. The presence of helper virus in vector stocks was tested by marker rescue assay and found to be <1 cfu/ml. Southern blot analysis showed that multiple copies of the vectors were present in the genome of high-titer producers and that both vectors could transfer CD3 gamma cDNA into the genome of 3T3 cells. The vectors were used to correct in vitro a CD3 gamma-deficient Jurkat mutant cell line lacking TCR/CD3 expression and termed JGN (for Jurkat gamma negative). Both vectors increased TCR/CD3 expression in JGN (normally 2% using WT31 monoclonal antibody) to 34% and 37%, respectively, in G418-selected 3-week bulk cultures. Two clones from transduced JGN cells termed JGN/LNCG(13) and JGN/LNCG(15) with high TCR/CD3 expression (88% and 79%, respectively), were selected for further analyses. First, CD3 gamma protein reconstitution was demonstrated by immunoprecipitation. Second, interleukin-2 production after TCR/CD3 engagement and TCR/CD3 down-modulation in response to phorbol myristate acetate were shown to be comparable to wild-type Jurkat cells. We conclude that LNCG and LGSN may be useful for gene therapy purposes.