276 research outputs found
Retinal nerve fiber layer thickness measurements in rats with spectral domain-optical coherence tomography.
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Meta-analysis of optical lowcoherence reflectometry versus partial coherence interferometry biometry
This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/A meta-analysis to compare ocular biometry measured by optical low-coherence reflectometry (Lenstar LS900; Haag Streit) and partial coherence interferometry (the IOLMaster optical biometer; Carl Zeiss Meditec). A systematic literature search was conducted for articles published up to August 6th 2015 in the Cochrane Library, PubMed, Medline, Embase, China Knowledge Resource Integrated Database and Wanfang Data. A total of 18 studies involving 1921 eyes were included. There were no statistically significant differences in axial length (mean difference [MD] 0 mm; 95% confidence interval (CI) −0.08 to 0.08 mm; p = 0.92), anterior chamber depth (MD 0.02 mm; 95% CI −0.07 to 0.10 mm; p = 0.67), flat keratometry (MD −0.05 D; 95% CI −0.16 to 0.06 D; p = 0.39), steep keratometry (MD −0.09 D; 95% CI −0.20 to 0.03 D; p = 0.13), and mean keratometry (MD −0.15 D; 95% CI −0.30 to 0.00 D; p = 0.05). The white to white distance showed a statistically significant difference (MD −0.14 mm; 95% CI −0.25 to −0.02 mm; p = 0.02). In conclusion, there was no difference in the comparison of AL, ACD and keratometry readings between the Lenstar and IOLMaster. However the WTW distance indicated a statistically significant difference between the two devices. Apart from the WTW distance, measurements for AL, ACD and keratometry readings may be used interchangeability with both devices
Integrated transcriptome analysis reveals miRNA-mRNA crosstalk in laryngeal squamous cell carcinoma.
Next generation sequencing (NGS) has proven to be a powerful tool in delineating myriads of molecular subtypes of cancer, as well as in revealing accumulation of genomic mutations throughout cancer progression. Whole genome microRNA (miRNA) and mRNA expression profiles were obtained from patients with laryngeal squamous cell carcinoma (LSCC) using deep sequencing technology, and were analyzed by utilizing integrative computational approaches. A large number of protein-coding and non-coding genes were detected to be differentially expressed, indicating a functional switch in LSCC cells. A total of 127 mutated genes were detected to be significantly associated with ectoderm and epidermis development. Eleven miRNAs were found to be differentially expressed, including a potential cancer suppressor miRNA, mir-34c, which was dramatically down-regulated. Integrated analysis of mRNA and miRNA transcriptomes further revealed correlated dynamics among 11 miRNAs and 138 targeted genes, forming a highly dynamical co-regulation network response to LSCC development
On the self-consistency of DFT-1/2
DFT-1/2 is an efficient band gap rectification method for density functional
theory (DFT) under local density approximation (LDA) or generalized gradient
approximation. It was suggested that non-self-consistent DFT-1/2 should be used
for highly ionic insulators like LiF, while self-consistent DFT-1/2 should
still be used for other compounds. Nevertheless, there is no quantitative
criterion prescribed for which implementation should work for an arbitrary
insulator, which leads to severe ambiguity in this method. In this work we
analyze the impact of self-consistency in DFT-1/2 and shell DFT-1/2
calculations in insulators or semiconductors with ionic bonds, covalent bonds
and intermediate cases, and show that self-consistency is required even for
highly ionic insulators for globally better electronic structure details. The
self-energy correction renders electrons more localized around the anions in
self-consistent LDA-1/2. The well-known delocalization error of LDA is
rectified, but with strong overcorrection due to the presence of additional
self-energy potential. However, in non-self-consistent LDA-1/2 calculations,
the electron wavefunctions indicate that such localization is much more severe
and beyond a reasonable range, because the strong Coulomb repulsion is not
counted in the Hamiltonian. Another common drawback of non-self-consistent
LDA-1/2 lies in that the ionicity of the bonding gets substantially enhanced,
and the band gap can be enormously high in mixed ionic-covalent compounds like
. The impact of LDA-1/2-induced stress is also discussed
comprehensively.Comment: 31 pages, 16 figure
Detection and Genetic Analysis of Porcine Bocavirus
Porcine Bocavirus (PBoV) has been reported to be associated with postweaning multisystemic wasting syndrome and pneumonia in pigs. In this study, a survey was conducted to evaluate the prevalence of PBoV in slaughter pigs, sick pigs, asymptomatic pigs and classical swine fever virus (CSFV) eradication plan herds in five provinces of China (Henan, Liaoning, Shandong, Hebei and Tianjin) by means of PCR targeting NS1 gene of PBoV. Among the total of 403 tissue samples, 11.41% were positive for PBoV. The positive rates of spleen (20.75%) and inguinal lymph node (27.18%) are higher than those of other organs. PCR products of twenty PBoV positive samples from slaughter pigs were sequenced for phylogenetic analysis. The result revealed that PBoV could be divided into 6 groups (PBoV-a~PBoV-f). All PBoV sequenced in this study belong to PBoV-a–PBoV-d with 90.1% to 99% nucleotide identities. Our results exhibited significant genetic diversity of PBoV and suggested a complex prevalence of PBoV in Chinese swine herds. Whether this diversity of PBoV has a significance to pig production or even public health remains to be further studied
A Review of Dynamic Wireless Power Transfer for In‐Motion Electric Vehicles
Dynamic wireless power transfer system (DWPT) in urban area ensures an uninterrupted power supply for electric vehicles (EVs), extending or even providing an infinite driving range with significantly reduced battery capacity. The underground power supply network also saves more space and hence is important in urban areas. It must be noted that the railways have become an indispensable form of public transportation to reduce pollution and traffic congestion. In recent years, there has been a consistent increase in the number of high‐speed railways in major cities of China, thereby improving accessibility. Wireless power transfer for train is safer and more robust when compared with conductive power transfer through pantograph mounted on the trains. Direct contact is subject to wear and tear; in particular, the average speed of modern trains has been increasing. When the pressure of pantograph is not sufficient, arcs, variations of the current, and even interruption in power supply may occur. This chapter provides a review of the latest research and development of dynamic wireless power transfer for urban EV and electric train (ET). The following key technology issues have been discussed: (1) power rails and pickups, (2) segmentations and power supply schemes, (3) circuit topologies and dynamic impedance matching, (4) control strategies, and (5) electromagnetic interference
A comprehensive comparison of central corneal thickness measurement
Author version made available in accordance with the publisher's policy.Purpose. To assess the repeatability and reproducibility of central corneal thickness (CCT) measurements by high-resolution rotating Scheimpflug imaging (Pentacam, Oculus) and Fourier-domain optical coherence tomography (RTvue-100, Optovue) after laser in situ keratomileusis (LASIK) and to compare the agreement with ultrasound pachymetry (USP).
Methods. Forty-seven eyes of 47 patients after LASIK were included in the study. The first examiner took two successive Pentacam and RTvue CCT measurements, and this was repeated once again by the second examiner to assess intraobserver and interobserver repeatability and reproducibility. After performing non-contact examinations, the corneas were measured by USP to compare the level of agreement among the three devices.
Results. All Pentacamcenter, Pentacamapex, Pentacamthinnest, and RTvue CCT measurements demonstrated high intraobserver repeatability, with respective precision (1.96 within-subject standard deviation) and intraclass correlation coefficients of 7.52, 7.43, 7.55, and 3.81 μm and 0.985, 0.986, 0.986, and 0.997; interobserver repeatability results were similar. All coefficients of variation were low: <1% for all measures. Compared with Pentacam and USP measurements, the RTvue measurement significantly underestimated CCT by a mean of 10.52 to 15.28 μm (p < 0.001) and 9.17 μm (p < 0.001), respectively. The agreement of USP with Pentacam and RTvue by Bland-Altman analysis spanned over 30 μm. The agreement of Pentacam with RTvue spanned approximate 20 μm.
Conclusions. Both Pentacam imaging and RTvue Fourier-domain optical coherence tomography provide reliable and interchangeable measurement of CCT in post-LASIK corneas. However, they cannot be considered to be clinically interchangeable with USP
Impact of Zr substitution on the electronic structure of ferroelectric hafnia
-based dielectrics are promising for nanoscale ferroelectric
applications, and the most favorable material within the family is
Zr-substituted hafnia, i.e., (HZO). The extent of Zr
substitution can be great, and x is commonly set to 0.5. However, the band gap
of is lower than , thus it is uncertain how
the Zr content should influence the electronic band structure of HZO. A reduced
band gap is detrimental to the cycling endurance as charge injection and
dielectric breakdown would become easier. Another issue is regarding the
comparison on the band gaps between /
superlattices and HZO solid-state solutions. In this work we systematically
investigated the electronic structures of ,
and HZO using self-energy corrected density functional theory. In particular,
the conduction band minimum of - is found to lie at an
ordinary k-point on the Brillouin zone border, not related to any interlines
between high-symmetry k-points. Moreover, the rule of HZO band gap variation
with respect to x has been extracted. The physical mechanisms for the
exponential reduction regime and linear decay regime have been revealed. The
band gaps of / ferroelectric superlattices are
investigated in a systematic manner, and the reason why the superlattice could
possess a band gap lower than that of is revealed through
comprehensive analysis.Comment: 23 pages, 9 figure
Highly efficient triazine/carbazole-based host material for green phosphorescent organic light-emitting diodes with low efficiency roll-off
Two novel triazin/carbazole-based host materials were designed and synthesized, which demonstrated outstanding EL performance with maximum CE, PE and EQE of 69.3 cd A−1, 54.2 lm W−1 and 21.9%, respectively.</p
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