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InGaN quantum dots (QDs) deposited on SiNx nanomasks have been investigated by atomic force microscopy, photoluminescence (PL), and photoluminescence excitation (PLE) measurements. It was found that the size of QDs can be well controlled by SiNx nanomasks, enabling the manipulation of quantum confinement effect. The PL spectra of InGaN QDs contain several fine structures, and the main peaks can be attributed to families of QDs with different sizes. The emission arising from InGaN QDs and GaN buffer layer can be clearly distinguished based on PLE measurement, which can be used to improve the interpretation in the previous reports. Our study indicates that the quantum confined Stark effect due to piezoelectric field plays a very important role in the optical properties of InGaN QDs, which is very useful for the application of optoelectronic devices. [ABSTRACT FROM AUTHOR]

The realization of the potential of carbon nanotori as elements of nanoscale devices based on their recently predicted unusual properties requires a thorough understanding of contacting these nanostructures. We carried out a series of calculations of the electric conductance of carbon nanotori contacted by single-wall carbon nanotubes to shed light on the effects of the geometry as well as the chemistry of the contacts. The relaxed structures of the contacted nanotori were determined by an order-N nonorthogonal tight-binding molecular dynamics scheme. The conductance was calculated using the Landauer-Büttiker formula based on a π-orbital Hamiltonian. We found that the conductance of the contacted carbon nanotorus is very sensitive to the transparency (chemistry) of the contacts. We also found that the equivalence (chemistry as well as geometry) of the contacts plays an important role in the transport properties. For example, a difference in the right contact and left contact will diminish the constructive quantum interference of the transmission as compared to the situation when the two contacts are equivalent. This conclusion is general and is expected to be applicable for any metallic contacts to the contacted carbon nanotori. [ABSTRACT FROM AUTHOR]

Food legumes like mungbean (Vigna radiata var. radiata), black gram (Vigna mungo), and rice bean (Vigna umbellata) have potential to diversify diets and agro-ecosystems of the tropics. Access to genetic diversity and phenotypic data are key issues for crop improvement. Large germplasm collections like the one at the World Vegetable Center may be used in detecting trait relationships and to identify accessions of interest for breeding. The current study provides results of more than 30 years of field characterization, including 9 numeric and 15 categorical descriptors and more than 10,000 accessions or sub-accessions. Core collections were established in black gram and rice bean. A positive correlation was detected between yield components such as seed size and pod length, and between these yield components and less desirable traits such as plant height and late maturity. High within-accession diversity was identified in several of the accessions. [ABSTRACT FROM AUTHOR]

Zerodur is a glass ceramic that has zero thermal expansion coefficient. It has good optical transmission in the visible light range. The zero thermal expansion property of Zerodur makes it an important substrate material for precision optical applications such as astronomical telescope and EUVL (13 nm) lithography. In this work, we demonstrated the crack-free micromachining of Zerodur using visible laser-induced-backside-wet-etching (v-LIBWE). We used eutectic Indium Gallium alloy (In/Ga) as the light absorber for the v-LIBWE process. Spectra of the light emission during the ablation or etching were recorded and compared using the real-time monitoring method. Measuring the intensity of the characteristic emission peaks allow us to determine the etching threshold in a more efficient way. [ABSTRACT FROM AUTHOR]

Objective: To compare the blood flow around the optic disc and related factors in patients with acute and chronic non-arteritic anterior ischemic optic neuropathy (NAION) and healthy volunteers with small disc cups under the same anatomical structure. Methods: This was a prospective case-control study. NAION patients with unilateral onset and healthy volunteers of the same phase were included in the study conducted at the Department of Ophthalmology of Peking Union Medical College Hospital between February 2017 and September 2018. Patients with a course of ≤ 3 months were categorized in the acute phase of NAION, and those with a course of >3 months were in the chronic phase of NAION. Healthy volunteers were in the control group. All subjects underwent the examination of best corrected visual acuity converted to logarithm of the minimum angle of resolution (LogMAR), measurement of non-contact intraocular pressure, slit lamp examination, small pupil fundus examination, and axial measurement. Optical coherence tomography was used to measure the thickness of retinal nerve fiber layers (RNFL) and retinal ganglion cell complex (GCC). Optical coherence tomography angiography was used to measure the vessel density around the optic disc. NAION patients underwent the visual field examination. Analysis of variance, non-parametric Mann-Whitney U test and Spearman coefficient was used for statistical analysis. Results: This study included 16 patients with acute phase of NAION, aged (57±9) years, 6 males and 10 females. There were 17 patients with chronic disease, aged (56±10) years, 7 males and 10 females. There were 15 healthy controls, aged (57±10) years old, 6 males and 9 females. There were no significant differences in age and gender between the groups (both P> 0.05). The RNFL and the GCC in the NAION chronic phase group were significantly thinner than those in the acute phase group [(78±38) μm vs. (191±99) μm, (75±19) μm vs. (98±28) μm; t= 4.389, 2.758; both P< 0.05]. The cup/disc area ratio, cup/disc vertical diameter ratio and cup/disc horizontal diameter ratio in the chronic phase group were larger than those in the acute phase group [0.18 (0.11, 0.31) vs. 0.05 (0.01, 0.18), 0.45 (0.39, 0.56) vs. 0.22 (0.11, 0.41), 0.39 (0.28, 0.54) vs. 0.20 (0.07, 0.42)], and the difference was statistically significant ( U =212.000, 208.000, 205.000; all P< 0.05). Compared with the optic disc vessel density in the control group (53%±6%), there was a significant decrease in the acute phase group and the chronic phase group (45%±7%, 41%±8%; t= 3.705, 4.940; both P< 0.01). The blood vessel density in the nasal inferior of the chronic phase group was significantly lower than that in the acute phase group (36%±8% vs. 42%±7%, P= 0.039), other sections didn't have significant difference (all P> 0.05). There were tortuous capillaries in 8/16 of the acute phase cases, with a low blood flow density and visual field defect in relative positions. Correlation analysis showed that the whole density and peripapillary density in the NAION patients were negatively correlated with LogMAR, mean visual field defect, cup/disc area ratio, focal loss of volume of GCC and general loss of volume of GCC ( r= -0.510, -0.733, -0.372, -0.532, -0.648; all P< 0.01), but positively correlated with GCC and RNFL thickness ( r= 0.604, 0.508; both P< 0.01). Conclusions: The optic disc vessel density in the acute phase and chronic phase of NAION is significantly reduced. The vessel density in the nasal area of the chronic phase is significantly reduced compared with the acute phase. The vessel density is correlated with visual acuity, visual field defect, disc indexes, thickness of RNFL and GCC. (Chin J Ophthalmol, 2019, 55: 677-686) .

Objective: To explore the correlation between the vessel density and the structure and visual function in patients with non-arteritic anterior ischemic optic neuropathy (NAION) in different stages. Methods: This case-control study included 25 NAION patients (28 eyes)of Peking Union Medical College Hospital from November 2017 to May 2018 and 25 healthy controls(HC) (25 eyes) of matched age and gender. General eye examination, visual field examination, and optical coherence tomography angiography were performed to obtain data of blood flow in the macular area and structure such as ganglion cell complex (GCC) and gross loss of volume (GLV), and focal loss of volume (FLV). All affected eyes were divided into the acute group (≤3 weeks), sub-acute group (4 to 12 weeks), and chronic group (>12 weeks) in line with the course of the disease. The group and regional analyses were made to carry out overall differences of blood flows and structures and the correlations with visual function. Results: There were 25 NAION patients with 28 eyes, 16 males and 9 females, aged (55±9) years. The acute group included 8 patients (8 eyes), and the sub-acute group included 10 patients (10 eyes), while the chronic group comprised 7 patients (10 eyes). The overall macular superficial vessel density of patients with NAION was significantly reduced compared with the HC(42.03%±5.70% vs .49.01%±3.34%, t= -5.546, P< 0.01), but the deep vessel density was not significantly reduced ( P> 0.05). The superficial vessel density of the acute group, sub-acute group, and chronic group was significantly decreased(47.41%±3.51% vs . 41.68%±3.09% vs .38.06%±5.93%, all P< 0.05). The GCC thickness in patients with NAION were significantly lower than the HC [(88.5±18.2) μm vs . (102.9±5.4)μm, P< 0.05]. The GLV and FLV in patients with NAION were significantly higher than the HC (12.733%±11.216% vs . 0.941%±0.852%, 6.295%±4.291% vs . 0.596%±0.460%, both P< 0.05). There was a correlation between the macular superficial vessel density and GCC thickness ( r= 0.606, P= 0.001), FLV( r= -0.552, P= 0.002), GLV ( r=- 0.685, P= 0.000) and mean sensitivity ( r= 0.493, P= 0.023). Conclusion: Compared with healthy controls, the macular superficial vessel density in NAION patients decreas along with the course of the disease, and its correlation with structural and visual function is revealed. (Chin J Ophthalmol, 2019, 55:195-202) .