Plasma source ion-implantation (PSII) is a new ion-implantation technique which has been optimized for surface modification of materials such as metals, plastics, and ceramics. PSII departs radically from conventional implantation technology by circumventing the line-of-sight restriction inherent in conventional ion implantation. In PSII, targets to be implanted are placed directly in a plasma source and then pulse biased to a high negative potential. A plasma sheath forms around the target and ions bombard the entire target simultaneously. Preliminary experiments have demonstrated that PSII: (1) efficiently implants ions to concentrations and depths required for surface modification, (2) produces material with improved microhardness and wear properties, and (3) dramatically improves the life of manufacturing tools in actual industrial applications. For example, the tool life of M-2 pierce punches used to produce holes in mild steel plate has been increased by a factor of 80.
a b s t r a c tPurpose: To explore the relationships among length of contact lens (CL) wear, degree of corneal staining and severity of dryness symptoms, and to determine whether these relationships differ between Asians and non-Asians. Methods: Adapted soft CL wearers (n = 395; 180 Asian, 215 non-Asian) were required to discontinue CL wear for at least 24 h and report to the University of California, Berkeley Clinical Research Center (UCB-CRC). Fluorescein corneal staining was graded according to Brien Holden Vision Institute scales. Length of CL wear was reported by subjects and subjective dryness ratings were collected using the UCB-CRC Dry Eye Flow Chart (DEFC). Results: More Asian CL wearers exhibited corneal staining compared to non-Asians, and Asian CL wearers had a higher mean grade of corneal staining (p < 0.001), as well as a higher mean DEFC classification (p < 0.001). The difference between Asians and non-Asians in grades of corneal staining extent and depth were significant (p < 0.001). Among non-Asian CL wearers, dryness symptoms decreased with more years of CL wear and increased in the presence of corneal staining, which was not the case for Asian CL wearers. Conclusions: Asian soft CL wearers reported more severe dryness symptoms and demonstrated more severe corneal staining overall compared to non-Asians. Among non-Asians, dryness symptoms were less severe on average with increased years of CL wear and more severe in the presence of corneal staining. Dryness severity does not appear to be related to years of CL wear or corneal staining among Asians.
Our results are consistent with emmetropization being tuned to mid-spatial frequencies. They also imply that form deprivation is not a graded phenomenon.
Leucine-rich repeat kinase 2 (LRRK2) G2019S is a relatively common mutation, associated with 1-3% of Parkinson's disease (PD) cases worldwide. G2019S is hypothesized to increase LRRK2 kinase activity. Dopaminergic neurons derived from induced pluripotent stem cells of PD patients carrying LRRK2 G2019S are reported to have several phenotypes compared to wild type controls, including increased activated caspase-3 and reactive oxygen species (ROS), autophagy dysfunction, and simplification of neurites. The common marmoset is envisioned as a candidate nonhuman primate species for comprehensive modeling of genetic mutations. Here, we report our successful use of CRISPR/Cas9 with repair template-mediated homology directed repair to introduce the LRRK2 G2019S mutation, as well as a truncation of the LRRK2 kinase domain, into marmoset embryonic and induced pluripotent stem cells. We found that, similar to humans, marmoset LRRK2 G2019S resulted in elevated kinase activity. Phenotypic evaluation after dopaminergic differentiation demonstrated LRRK2 G2019S-mediated increased intracellular ROS, decreased neuronal viability, and reduced neurite complexity. Importantly, these phenotypes were not observed in clones with LRRK2 truncation. These results demonstrate the feasibility of inducing monogenic mutations in common marmosets and support the use of this species for generating a novel genetic-based model of PD that expresses physiological levels of LRRK2 G2019S.Leucine-rich repeat kinase 2 (LRRK2) G2019S is a relatively common cause of Parkinson's disease (PD) 1 . Located in the kinase domain of LRRK2, G2019S is hypothesized to slow transition of the kinase from active to inactive forms, thus effectively increasing Vmax of the enzyme by ~2 fold. This increased kinase activity has been identified as the basis of many PD-associated dysregulated intracellular mechanisms 2-7 . Relative to other common PD-associated gene mutations (e.g. SNCA, Parkin, PINK1, GBA), LRRK2 G2019S has a relatively high penetrance 1,8,9 . The prevalence, penetrance, and sequence conservation of this mutation makes it an excellent target for genetic modeling of PD in a nonhuman species.Because of its genetic similarity to the human genome and shorter lifespan compared to rhesus monkeys 10 , the common marmoset (Callithrix jacchus) has emerged as a candidate nonhuman primate species for modeling age-related disorders, including PD. Genetic approaches for modeling PD (or other diseases) in monkeys has been achieved by introducing the mutant gene using viral vector technologies, via direct intracerebral delivery or microinjection delivery in the oocyte 11,12 . In both cases, the mutant protein is over-expressed at supraphysiological levels. In addition, intracerebral delivery requires brain surgery, and its effects are limited to the target region, which contradicts the current understanding of neurodegeneration as a multisystem disease.Cj-iPSC parental wild type and LRRK2 G2019S clones were fixed and immunostained for the dopaminergic and neuronal markers...
Thin films of Bi 2 Te 3 and PbTe were produced by sputtering using targets of stoichiometric compounds. The compositions of these sputtered thin films were analyzed by the electron microprobe; the Bi2 Te 3 film showed nonstoichiometric compositions of Bi = 44.5 at. %, Te = 55.5 at. %, whereas the compositions ofPbTe films were stoichiometric. The morphology of these sputtered films was established to be polycrystalline by x-ray diffraction (XRD). XRD peaks of Biz Te 3 films revealed the existence of nonstoichiometric crystalline phases; PbTe films have a single cubic phase with (200) preferred orientation. X-ray photoelectron spectroscopy chemical state analysis on both Bi 2 Te 3 and PbTe films showed that Bi, Pb, and Te have one chemical state consistent with the valence state in the compounds. Room temperature carrier concentration and Hall mobility ofBiTe 1 film were measured to be 7.2 X 10 20 em --3 and 15 cm2/V-s respectively; the corresponding values of PbTe films are 5.6X 10 19 cm-3 and 38 cm 2 /V-s, respectively. Doping experiments on Bi2 Te 3 and PbTe films using a single target sputtering system are reported. Sputtered PbTe films doped with Sn have shown promising thermoelectric properties.
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