Three-photon-excited upconversion luminescence of niobium ions doped silicate glass by a femtosecond laser irradiation

We report on the bluish green upconversion luminescence of niobium ions doped silicate glass by a femtosecond laser irradiation. The dependence of the fluorescence intensity on the pump power density of laser indicates that the conversion of infrared irradiation to visible emission is dominated by three-photon excitation process. We suggest that the charge transfer from O-2-to Nb5+ can efficiently contribute to the bluish green emission. The results indicate that transition metal ions without d electrons play an important role in fields of optics when embedded into silicate glass matrix. (C) 2008 Optical Society of America.

Self-adaptive optical systems for long-distance flying optics

The focusing characteristics of long-distance flying optics were studied systemically for TEMmn Gaussian beams. The results show that the ABCD law of parameter q can be extended to Gaussian modes of any order when waist radius w in the imaginary part of parameter q is replaced by Rayleigh range Z(R) of a certain resonator in the equation. The difference between the real focal length and the geometric focal length, defined as Delta f, was calculated for laser applications. A novel self-adaptive optical system was demonstrated for precisely controlling the focusing characteristics of long-distance flying optics, Theoretical analyses and experimental results were consistent. (c) 2006 Optical Society of America.

Diffraction at 8-keV x-rays of Bragg-Fresnel optics

The basic elements of Bragg-Fresnel multilayer optics are multilayer gratings. In this paper, the fabrication process for the simplest Bragg-Fresnel multilayer optics is given; the diffraction measurements at 8-keV x rays of multilayer gratings are presented; and the measurement results in the diffraction spectrum are analyzed and discussed in detail. (C) 1996 Society of Photo-Optical Instrumentation Engineers.

Chromosome painting between human and lorisiform prosimians: Evidence for the HSA 7/16 Synteny in the primate ancestral karyotype

Multidirectional chromosome painting with probes derived from flow-sorted chromosomes of humans (Homo sapiens, HSA, 2n = 46) and galagos (Galago moholi, GMO, 2n = 38) allowed us to map evolutionarily conserved chromosomal segments among humans, galagos, a

B2 肾上腺素受体多肽16 位基因型与夜间哮喘表现型的关系

目的　探讨B2 肾上腺素受体(B2AR) 16、27 位基因多态性与夜间哮喘表现型的关系。方法　以最大呼 气流速(PEFR ) 为标准, 将49 例哮喘患者分为夜间哮喘组(25 例) 和非夜间哮喘组(24 例)。用PCR 产物直接测序确 定B2AR 16、27 位基因型分布, 以及分析两个位点各种基因型与两组病例PEFR、第一秒用力呼气量(FEV 1) 以及用药 情况之间的关系。结果　以PEFR 为标准, 夜间哮喘组PEFR 在夜间平均下降33. 6% , 非夜间哮喘组下降7. 0% , 二 者差异显著(P < 0. 001)。夜间哮喘组和非夜间哮喘组(白天) 基础FEV 1 分别为73. 7 % 和85. 8 % , 也具有显著性差 异(P < 0. 001)。Gly16 的等位基因频率在夜间哮喘组56. 0% 明显较非夜间哮喘组22. 9% 高(P < 0. 05) , Gly16 集中 分布于夜间哮喘组。27 位点的多态性在两组间无显著性差异。结论　B2AR Gly16 基因型与夜间哮喘可能有关系。

mtDNA Data Indicate a Single Origin for Dogs South of Yangtze River, Less Than 16,300 Years Ago, from Numerous Wolves

There is no generally accepted picture of where, when, and how the domestic dog originated. Previous studies of mitochondrial DNA (mtDNA) have failed to establish the time and precise place of origin because of lack of phylogenetic resolution in the so fa

Interaction between human interleukin-16 and CD4 receptor of HIV-1

AIM: To study the interaction between human interleukin-16 (IL-16) and the receptor CD4 (T-lymphocyte differentiation antigen) of human immunodeficiency virus type 1 (HIV-1). METHODS: Two structurally con served regions (SCRs) of human IL-16 were built by the SYBYL/Biopolymer module using the corresponding transmembrane (TM) domain of human interleukin-1 (HIL-4) and HIL-2 as the templates. The coordinates for amino-terminal residue sequence, carboxyl-terminal residue sequences, and cytoplasm loops were generated using Biopolymer's LOOP SEARCH algorithm. RESULTS: HIL-16 first formed a homodimer, then contacted with CD4 dimer further forming a dimeric complex. Subsequently, the dimeric complex constructed the tetrameric complex by two disulfide bridges between the cysteines of HIL-16 (Cys31-Cys31). CONCLUSION: The interaction model is useful to propose the action mechanism of HIL-16 and is beneficial for rational designing of novel anti-HIV drugs.

Cloning and analysis of 16 Rab genes from macronuclear DNA of Euplotes octocarinatus

Rab proteins belong to the largest family of the Ras superfamily of small GTPase that play an important role in intracellular vesicular traffic. So far, almost 60 members of Rab family have been identified in mammalian cells. To further study the diversity and function of Rab protein in evolution, unicellular protozoa ciliates, Euplotes octocarinatus, were used in this study, Rab genes were screened by PCR method from macronuclear DNA of E. octocarinatus. Sixteen Rab genes were obtained. They share 87.6 - 99.5% identities. Highly conserved GTP-binding domains were found. There are some hot regions that diverse sharply in these genes as well.