Abstract
We propose a polarization-controlled ultrasmall single-photon emitter that combines a single photon source and an elliptical split ring (SR) type metamaterial element. Simulations using the ...finite difference time domain method showed that in elliptical metamaterial elements, the annular mode is suppressed and axial electric field oscillations occur preferentially, resulting in upward light emission from the photon source with controlled polarization. We fabricated prototype devices by focused ion beam lithography and PbS quantum dots. Evaluation of the optical properties of the devices revealed that the emission spectrum width was narrower and the emission lifetime was shorter than those of quantum dot ensemble, and that the polarization was controlled along the minor axis of ellipse. These suggested that the quantum dot emission and the metamaterial element resonated as expected. The combination of a single quantum dot and a single elliptical SR-type metamaterial element was shown to have the potential to operate as a polarization-controlled single-photon emitter.
•The quantitative trait loci for bull fertility are economically important.•The genomic region for bull conception rate was examined in Japanese Black bulls.•A homozygous genotype on Bos taurus ...autosome 5 is related to low bull fertility.•The AA genotype, a recessive risk allele, was identified at position 116 408 653.•The AA genotype of g.116408653G > A is a useful index for low-fertile bulls.
Over the years, there has been considerable variation in the bull conception rate (BCR) of Japanese Black cattle; moreover, several Japanese Black bulls with a low BCR of ≤10% have been identified. However, the alleles responsible for the low BCR are not determined yet. Therefore, in this study, we aimed to identify single-nucleotide polymorphisms (SNPs) for predicting low BCR. To this end, the genome of Japanese Black bulls was comprehensively examined by a genome-wide association study with whole-exome sequencing (WES), and the effect of the identified marker regions on BCR was determined. The WES analysis of six sub-fertile bulls with a BCR of ≤10% and 73 normal bulls with a BCR of ≥40% identified a homozygous genotype for low BCR in Bos taurus autosome 5 in the region between 116.2 and 117.9 Mb. The g.116408653G > A SNP in this region had the most significant effect on the BCR (P-value = 1.0 × 10−23), and the GG (55.4 ± 11.2%) and AG (54.4 ± 9.4%) genotypes in the SNP had a higher phenotype than the AA (9.5 ± 6.1%) genotype for the BCR. The mixed model analysis revealed that g.116408653G > A was related to approximately 43% of the total genetic variance. In conclusion, the AA genotype of g.116408653G > A is a useful index for identifying sub-fertile Japanese Black bulls. Some positive and negative effects of SNP on the BCR were presumed to identify the causative mutations, which can help evaluate bull fertility.
Local adaptation is important in evolutionary processes and speciation. We used multiple tests to identify several candidate genes that may be involved in local adaptation from 1026 loci in 14 ...natural populations of Cryptomeria japonica, the most economically important forestry tree in Japan. We also studied the relationships between genotypes and environmental variables to obtain information on the selective pressures acting on individual populations. Outlier loci were mapped onto a linkage map, and the positions of loci associated with specific environmental variables are considered. The outlier loci were not randomly distributed on the linkage map; linkage group 11 was identified as a genomic island of divergence. Three loci in this region were also associated with environmental variables such as mean annual temperature, daily maximum temperature, maximum snow depth, and so on. Outlier loci identified with high significance levels will be essential for conservation purposes and for future work on molecular breeding.
This paper presents an anthropomorphic robot hand, called the Gifu hand II, which has a thumb and four fingers, all the joints of which are driven by servomotors built into the fingers and the palm. ...The thumb has four joints with four-degrees-of-freedom (DOF), the other fingers have four joints with 3-DOF, and two axes of the joints near the palm cross orthogonally at one point, as is the case in the human hand. The Gifu hand II can be equipped with six-axes force sensor at each fingertip, and a developed distributed tactile sensor with 624 detecting points on its surface. The design concepts and specifications of the Gifu hand II, the basic characteristics of the tactile sensor, and the pressure distributions at the time of object grasping are described and discussed herein. Our results demonstrate that the Gifu hand II has a high potential to perform dexterous object manipulations like the human hand.
Dnmt3a and Dnmt3b, which are known as functional de novo methyltransferases, are responsible for creating genomic methylation patterns during mammalian development. Recently, we have shown that ...specific expression of Dnmt3b in epiblast, embryonic ectoderm, hematopoietic progenitor cells and spermatogonia cells is followed by Dnmt3a expression (Watanabe D, Suetake I, Tada T, Tajima S (2002) Stage- and cell-specific expression of Dnmt3a and Dnmt3b during embryogenesis. Mech Dev 118:187–190; Watanabe D, Suetake I, Tajima S, Hanaoka K (2004) Expression of Dnmt3b in mouse hematopoietic progenitor cells and spermatogonia at specific stages. Gene Expr Patterns 5:43–49). In this study, we analyzed the expression of mouse de novo methyltransferases during development of the nervous systems. In the embryonic olfactory epithelium (OE), Dnmt3b was specifically expressed in Mash1 positive globose basal cells (i.e. transiently amplifying neural progenitor cells), while Dnmt3a was expressed in immature olfactory receptor neurons. Dnmt3b-positive cells were rarely observed in the adult OE, but were increased in regenerating OE with intranasal ZnSO
4 administration. Dnmt3b was also detected in the E8.5 neural plate, E10.5 spinal cord and retina cells, while Dnmt3a was expressed in postmitotic young neurons. Furthermore, Dnmt3b was specifically expressed in ES cells, while Dnmt3a was transiently expressed during neural cell differentiation of ES cells. Dnmt3b is specifically expressed in progenitor cells during hematopoiesis, spermatogenesis and neurogenesis, suggesting an important role in the initial steps of progenitor cell differentiation. Dnmt3a is expressed in postmitotic young neurons following the Dnmt3b expression. Dnmt3a may be required for the establishment of tissue-specific methylation patterns of the genome. The coordinated expression of de novo methyltransferases from Dnmt3b to Dnmt3a suggests conserved mechanisms of de novo methylation of the genome and different functions for Dnmt3b and Dnmt3a during progenitor cell development.
The semen production traits of bulls from 2 major cattle breeds in Japan, Holstein and Japanese Black, were analyzed comprehensively using genome-wide markers. Weaker genetic correlations were ...observed between the 2 age groups (1 to 3 yr old and 4 to 6 yr old) regarding semen volume and sperm motility compared with those observed for sperm number and motility after freeze-thawing. The preselection of collected semen for freezing had a limited effect. Given the increasing importance of bull proofs at a young age because of genomic selection and the results from preliminary studies, we used a multiple-trait model that included motility after freeze-thawing with records collected at young ages. Based on variations in contemporary group effects, accounting for both seasonal and management factors, Holstein bulls may be more sensitive than Japanese Black bulls to seasonal environmental variations; however, the seasonal variations of contemporary group effects were smaller than those of overall contemporary group effects. The improvement of motilities, recorded immediately after collection and freeze-thawing, was observed in recent years; thus, good management and better freeze-thawing protocol may alleviate seasonal phenotypic differences. The detrimental effects of inbreeding were observed in all traits of both breeds; accordingly, the selection of candidate bulls with high inbreeding coefficients should be avoided per general recommendations. Semen production traits have never been considered for bull selection. However, negative genetic trends were observed. The magnitudes of the estimated h were comparable to those of other economically important traits. A single-step genomic BLUP will provide more accurate predictions of breeding values compared with BLUP; thus, marker genotype information is useful for estimating the genetic merits of bulls for semen production traits. The selection of these traits would improve sperm viability, a component related to breeding success, and alleviate negative genetic trends.
Size, shape, and surface properties of superparamagnetic iron oxide nanoparticles (SPIONs) can influence their interaction with biological systems, particularly the incorporation by tumor cells and ...consequently the biological activity and efficiency in biomedical applications. Several strategies have been used to evaluate cellular uptake of SPIONs. While qualitative methods are generally based on microscopy techniques, quantitative assays are carried out by techniques such as inductively coupled plasma-mass spectrometry and flow cytometry. However, inexpensive colorimetric methods based on equipments commonly found in chemistry and biochemistry laboratories are preferred for routine measurements. Nevertheless, colorimetric assays must be used judiciously, particularly when nanoparticles are involved, since their interaction with biological constituents tends to lead to quite underestimated results. Thus, herein described is a colorimetric protocol using 2,2′-bipyridine as chromogenic ligand, where each step was optimized and validated by total reflection X-ray fluorescence spectroscopy, realizing a highly reproducible and reliable method for determination of iron content in cells incubated with SPIONs. The limit of blank and limit of detection were determined to be as low as 0.076 and 0.143 μg Fe/mL, using sample volumes as small as 190 μL and a number of cells as low as 2.0 × 10
5
. Furthermore, three different types of surface-functionalized nanoparticles were incorporated in cells and evaluated through this protocol, enabling to monitor the additive effect of
o
-phosphorylethanolamine (PEA) and folic acid (FA) conjugation on iron oxide nanoparticles (SPION-PEA and SPION-PEA/FA), that enhanced the uptake by HeLa cells, respectively, by four and ten times when compared to SPIONs conjugated with nonbioactive molecules.
Graphical abstract
Colorimetric determination of superparamagnetic iron oxide nanoparticles (SPIONs) incorporated by cells.
Melanoma is a severe metastatic skin cancer with poor prognosis and no effective treatment. Therefore, novel therapeutic approaches using nanotechnology have been proposed to improve therapeutic ...effectiveness. Lipid-core nanocapsules (LNCs), prepared with poly(ε-caprolactone), capric/caprylic triglyceride, and sorbitan monostearate and stabilized by polysorbate 80, are efficient as drug delivery systems. Here, we investigated the effects of acetyleugenol-loaded LNC (AcE-LNC) on human SK-Mel-28 melanoma cells and its therapeutic efficacies on melanoma induced by B16F10 in C57B6 mice. LNC and AcE-LNC had z-average diameters and zeta potential close to 210 nm and -10.0 mV, respectively. CytoViva(®) microscopy images showed that LNC and AcE-LNC penetrated into SK-Mel-28 cells, and remained in the cytoplasm. AcE-LNC in vitro treatment (18-90×10(9) particles/mL; 1 hour) induced late apoptosis and necrosis; LNC and AcE-LNC (3-18×10(9) particles/mL; 48 hours) treatments reduced cell proliferation and delayed the cell cycle. Elevated levels of nitric oxide were found in supernatant of LNC and AcE-LNC, which were not dependent on nitric oxide synthase expressions. Daily intraperitoneal or oral treatment (days 3-10 after tumor injection) with LNC or AcE-LNC (1×10(12) particles/day), but not with AcE (50 mg/kg/day, same dose as AcE-LNC), reduced the volume of the tumor; nevertheless, intraperitoneal treatment caused toxicity. Oral LNC treatment was more efficient than AcE-LNC treatment. Moreover, oral treatment with nonencapsulated capric/caprylic triglyceride did not inhibit tumor development, implying that nanocapsule supramolecular structure is important to the therapeutic effects. Together, data herein presented highlight the relevance of the supramolecular structure of LNCs to toxicity on SK-Mel-28 cells and to the therapeutic efficacy on melanoma development in mice, conferring novel therapeutic mechanisms to LNC further than a drug delivery system.
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