In this work, we reported a phenanthroline-based tetradentate ligand with hard-soft donors combined in the same molecule, N,N'-diethyl-N,N'-ditolyl-2,9-diamide-1,10-phenanthroline (Et-Tol-DAPhen), for the group separation of actinides over lanthanides. The synthesis and solvent extraction as well as complexation behaviors of the ligand with actinides and lanthanides are studied experimentally and theoretically. The ligand exhibits excellent extraction ability and high selectivity toward hexavalent, tetravalent, and trivalent actinides over lanthanides in highly acidic solution. The chemical stoichiometry of Th(IV) and U(VI) complexes with Et-Tol-DAPhen is determined to be 1:1 using X-ray crystallography. The stability constants of some typical actinide and lanthanide complexes of Et-Tol-DAPhen are also determined in methanol by UV-vis spectrometry. Density functional theory (DFT) calculations reveal that the An-N bonds of the Et-Tol-DAPhen complexes have more covalent characters than the corresponding Eu-N bonds, which may in turn lead to the selectivity of Et-Tol-DAPhen toward actinides. This ligand possesses merits of both alkylamide and 2,9-bis-(5,6-dialkyl-1,2,4-triazin-3-yl)-1,10-phenanthroline (R-BTPhen) extractants for efficient actinide extraction and the selectivity toward minor actinides over lanthanides and hence renders huge potential opportunities in high-level liquid waste (HLLW) partitioning.

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The domestic pig has been widely used as an important large animal model. Precise and efficient genetic modification in pig provides a great promise in biomedical research. Recently, clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated (Cas) system has been successfully used to produce many gene-targeted animals. However, these animals have been generated by co-injection of Cas9 mRNA and single-guide RNA (sgRNA) into one-cell stage embryos, which mostly resulted in mosaicism of the modification. One or two rounds of further breeding should be performed to obtain homozygotes with identical genotype and phenotype. To address this issue, gene-targeted somatic cells can be used as donor for somatic cell nuclear transfer (SCNT) to produce gene-targeted animals with single and identical mutations. In this study, we applied Cas9/sgRNAs to effectively direct gene editing in porcine fetal fibroblasts and then mutant cell colonies were used as donor to generate homozygous gene-targeted pigs through single round of SCNT. As a result, we successfully obtained 15 tyrosinase (TYR) biallelic mutant pigs and 20 PARK2 and PINK1 double-gene knockout (KO) pigs. They were all homozygous and no off-target mutagenesis was detected by comprehensive analysis. TYR (-/-) pigs showed typical albinism and the expression of parkin and PINK1 were depleted in PARK2 (-/-)/PINK1 (-/-) pigs. The results demonstrated that single- or double-gene targeted pigs can be effectively achieved by using the CRISPR/Cas9 system combined with SCNT without mosaic mutation and detectable off-target effects. This gene-editing system provides an efficient, rapid, and less costly manner to generate genetically modified pigs or other large animals.

Huntington's disease (HD) is characterized by preferential loss of the medium spiny neurons in the striatum. Using CRISPR/Cas9 and somatic nuclear transfer technology, we established a knockin (KI) pig model of HD that endogenously expresses full-length mutant huntingtin (HTT). By breeding this HD pig model, we have successfully obtained F1 and F2 generation KI pigs. Characterization of founder and F1 KI pigs shows consistent movement, behavioral abnormalities, and early death, which are germline transmittable. More importantly, brains of HD KI pig display striking and selective degeneration of striatal medium spiny neurons. Thus, using a large animal model of HD, we demonstrate for the first time that overt and selective neurodegeneration seen in HD patients can be recapitulated by endogenously expressed mutant proteins in large mammals, a finding that also underscores the importance of using large mammals to investigate the pathogenesis of neurodegenerative diseases and their therapeutics.

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Exposure to nanoparticles has presented potential risks to human cardiorespiratory systems. Pulmonary retention and extrapulmonary redistribution of inhaled nanoparticles have been considered to be important contributing factors of cardiorespiratory diseases. In the present work, 22-nm (59)Fe(2)O(3) nanoparticles (radioactive isotope (59)Fe-labeled ferric oxide nanoparticles) were intratracheally instilled into the male Sprague-Dawley rats at a dose of 4 mg/rat. Extrapulmonary distribution of (59)Fe(2)O(3) in organs and its metabolism in lung, blood, urine, and feces were measured for 50 days of exposure. Phagocytosis and clearance of agglomerated nano-Fe(2)O(3) by monocytes/macrophages were observed by histopathology and inductively coupled plasma-mass spectrometry examination. Our results showed intratracheal-instilled nano-(59)Fe(2)O(3) could pass through the alveolar-capillary barrier into systemic circulation within 10 min that consisted with one-compartment kinetic model. The nano-(59)Fe(2)O(3) in the lung was distributed to organs rich in mononuclear phagocytes, including liver, spleen, kidney and testicle. The plasma elimination half-life of nano-(59)Fe(2)O(3) was 22.8 days and the lung clearance rate was 3.06 microg/day, indicating the systemic accumulation and lung retention had occurred. The deposited nano-Fe(2)O(3) in interstitial lung was probably contributed by the particles escaping from alveolar macrophages phagocytosis and macrophages clearance function overloading. Our results suggest that the effect of Fe(2)O(3) nanoparticles exposure, even at low concentration, should be assessed because of the potential lung and systemic cumulative toxicity of the nanoparticles.