22 research outputs found
Posterior pole asymmetry analysis and retinal nerve fibre layer thickness measurements in primary angle-closure suspect patients
Abstract Purpose To measure peripapillary retinal nerve fiber layer (RNFL) thickness and posterior pole retinal thickness in primary angle-closure suspects (PACS) by Spectral domain optical coherence tomography (SD-OCT) and to be compared with normal subjects. Methods Thirty five primary angle-closure suspect patients and thirty normal subjects were enrolled in this study. Peripapillary RNFL and posterior pole retinal thickness by posterior pole asymmetry analysis (PPAA) in SD-OCT were measured. Results No significant difference was found in both groups on age, sex distribution, refractive error, intraocular pressure (IOP) and axial length. The PACS group exhibited significantly thinner macular retinal thickness and larger asymmetry on posterior pole region compared with the control group. Yet no significant difference of peripapillary RNFL parameters was found between PACS group and normal control group. A negative correlation was observed between the total retinal thickness on posterior pole region and age when all the PACS participants were analyzed. Conclusions Posterior pole retinal thickness measurements obtained by Heidelberg Spectralis SD-OCT using PPAA showed significant thinner change in PACS group than healthy controls. Only age seemed to be an indicator in the occurrence of glaucomatous damage in PACS patients
Evaluation of peripapillary choroidal distribution in children by enhanced depth imaging optical coherence tomography
Abstract Background To evaluate the peripapillary choroidal thickness (PPCT) in Chinese children aged 6 to 12 years old and to analyze correlative factors. Methods PPCT was measured with enhanced depth imaging optical coherence tomography (EDI-OCT) in 154 children (76 myopes and 78 emmetropia) aged 6 to 12 years, with spherical equivalent refractive errors between + 0.50 and − 5.50 diopters(D). Peripapillary choroidal imaging was performed using circular scans of a diameter of 3.4 mm around the optic disc. PPCT and the corresponding peripapillary retinal thickness (PPRT) were measured by EDI-OCT at nine positions: I, inferior; IN, inferonasal; IT, inferotemporal; N, nasal; T, temporal; S, superior; SN, superonasal; ST, superotemporal, and the Fovea Centralis. Results The mean global PPCT was 165.80 ± 39.86 μm.The mean global PPRT was 101.47 ± 10.74 μm. The Inferior had the thinnest PPCT but the thickest PPRT (p < 0.001), while the Nasal had thickest PPCT but the thinnest PPRT (p < 0.001). Significant differences in RT between the myopic group and the emmetropic group were found at all positions except T, TS, S and the fovea. Myopic group had thinner choroidal thickness (CT) than that of emmetropic group at all measured positions. Choroidal thickness had negative relation with the corresponding retinal thickness, age and axial length. Conclusion The peripapillary choroid was thicker nasally and thinner inferiorly, while the peripapillary retina was thickest inferiorly and thinnest nasally. Myopic group had thinner PPCT. The axial length was found to be negatively correlated to PPCT
Vessel Density and Structural Measurements in Primary Angle-Closure Suspect Glaucoma Using Optical Coherence Tomography Angiography
Purpose. To measure the macular retinal vessel density (VD) and peripapillary retinal nerve fiber layer (RNFL) in primary angle-closure suspects (PACS) by Angio-OCT to be compared with normal subjects. Methods. Primary angle-closure suspect patients and normal subjects were enrolled in this study. The demographic and clinical characteristics of all subjects, such as RNFL thickness, retinal vessel density, and ocular perfusion pressure, were compared. Results. No significant difference was found in both groups on age, sex distribution, intraocular pressure (IOP), and retinal vessel density. The PACS group exhibited significantly thicker RNFL thickness compared with the control group. The deep vessel density was negatively associated with age (P=−0.034), while IOP had negative association with ACD (P=−0.019). OPP was independently associated with RNFL (B=0.334, P=0.038) in the PACS group. Conclusions. OCTA showed significant thicker change on RNFL in the PACS group. Only OPP was independently associated with RNFL in the PACS group
Axial Length and Ocular Development of Premature Infants without ROP
Purpose. To investigate the ocular parameters of premature infants without ROP at gestational age (GA) more than 28 weeks and their relationship with growth parameters. Methods. 76 preterm infants without ROP and 65 term infants were involved to undergo portable slit lamp, RetCam3, ultrasonic A-scan biometry, and cycloplegic streak examination at their 40 weeks’ postconceptional ages (PCA). Ocular parameters of infants’ right eye and growth parameters were used for analysis. Results. All the infants were examined at 40 weeks’ PCA. No significant difference was found between male and female in axial length of preterm infants (p = 0.993) and term infants (p=0.591). Significant differences were found in axial length (AL), anterior chamber depth (ACD), lens thickness (LT), and vitreous depth (VD) between preterm and term infants. No significant correlation was found between AL and spherical equivalent in preterm infants’ group. In preterm group, AL was significantly correlated with gestational age (GA), birth weight (BW), and head circumference (HC). Conclusions. Preterm infants had shorter AL, shallow ACD, thicker LT, and thinner VD compared to term infants. Refractive error in preterm infants at GA between 28 to 37 weeks was not related to axial length. Among all the growth parameters of preterm infants, GA, BW, and HC had effect on axial length
Multiscale voting mechanism for rice leaf disease recognition under natural field conditions.
Rice leaf disease (RLD) is one of the major factors that cause the decline in production, and the automatic recognition of such diseases under natural field conditions is of great significance for timely targeted rice management. Although many machine learning approaches have been proposed for RLD recognition, scale variation is still a challenging problem that affects prediction accuracy, especially in uncontrolled environments, such as natural fields. Also, the existing RLD data sets are collected in laboratory environments or with a constant scale, which cannot be used to develop the RLD classification algorithms under natural field conditions. To tackle these particular challenges, we propose a multiscale voting mechanism for RLD recognition under natural field conditions. First, data from 26 rice fields were collected to build a data set containing 6046 images of RLD. Afterwards, a feature pyramid was embedded into a mainstream classification architecture (EfficientNet) with a bottom-up and top-down pathway for feature fusion at different scales. To further reduce the inconsistency among multiscaled features, a multiscale voting strategy with regard to probability distribution was proposed to integrate the decisions from various scales. Each proposed module was carefully validated through an ablation study to demonstrate its effectiveness, and the proposed method was compared with a few state-of-the-art algorithms, including the Single Shot MultiBox Detector, Feature Pyramid Networks, Path Aggregation Network, and Bidirectional Feature Pyramid Network. Experimental results have shown that the classification accuracy of our model can reach 90.24%, which is 4.48% higher than that of the original EfficientNet-b0 model and 1.08% higher than that of existing multiscale networks. Finally, we exploit and demonstrate a visualized explanation for the boosted performance from the proposed model. As an extra outcome, our data set and codes are available at http://github.com/huanghsheng/multiscale-voting-mechanism to benefit the whole research community
Strong Near-Infrared Absorbing and Biocompatible CuS Nanoparticles for Rapid and Efficient Photothermal Ablation of Gram-Positive and -Negative Bacteria
<i>Staphylococcus aureus</i> (<i>S. aureus</i>) and <i>Escherichia coli</i> (<i>E. coli)</i> are the most
common infectious bacteria in our daily life, and seriously affect
human’s health. Because of the frequent and extensive use of
antibiotics, the microbial strains forming drug resistance have become
more and more difficult to deal with. Herein, we utilized bovine serum
albumin (BSA) as the template to synthesize uniform copper sulfide
(CuS) nanoparticles via a biomineralization method. The as-prepared
BSA-CuS nanocomposites showed good biocompatibility and strong near-infrared
absorbance performance and can be used as an efficient photothermal
conversion agent for pathogenic bacteria ablation with a 980 nm laser
at a low power density of 1.59 W/cm<sup>2</sup>. The cytotoxicity
of BSA-CuS nanocomposite was investigated using skin fibroblast cells
and displayed good biocompatibility. Furthermore, the antibacterial
tests indicated that BSA-CuS nanocomposite showed no antibacterial
activity without NIR irradiation. In contrast, they demonstrated satisfying
killing bacterial ability in the presence of NIR irradiation. Interestingly, <i>S. aureus</i> and <i>E. coli</i> showed various antibacterial
mechanisms, possibly because of the different architectures of bacterial
walls. Considering the low cost, easy preparation, excellent biocompatibility
and strong photothermal convention efficiency (24.68%), the BSA-CuS
nanocomposites combined with NIR irradiation will shed bright light
on the treatment of antibiotic-resistant pathogenic bacteria
CEPC Technical Design Report -- Accelerator
The Circular Electron Positron Collider (CEPC) is a large scientific project initiated and hosted by China, fostered through extensive collaboration with international partners. The complex comprises four accelerators: a 30 GeV Linac, a 1.1 GeV Damping Ring, a Booster capable of achieving energies up to 180 GeV, and a Collider operating at varying energy modes (Z, W, H, and ttbar). The Linac and Damping Ring are situated on the surface, while the Booster and Collider are housed in a 100 km circumference underground tunnel, strategically accommodating future expansion with provisions for a Super Proton Proton Collider (SPPC). The CEPC primarily serves as a Higgs factory. In its baseline design with synchrotron radiation (SR) power of 30 MW per beam, it can achieve a luminosity of 5e34 /cm^2/s^1, resulting in an integrated luminosity of 13 /ab for two interaction points over a decade, producing 2.6 million Higgs bosons. Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons, facilitating precise measurements of Higgs coupling at sub-percent levels, exceeding the precision expected from the HL-LHC by an order of magnitude. This Technical Design Report (TDR) follows the Preliminary Conceptual Design Report (Pre-CDR, 2015) and the Conceptual Design Report (CDR, 2018), comprehensively detailing the machine's layout and performance, physical design and analysis, technical systems design, R&D and prototyping efforts, and associated civil engineering aspects. Additionally, it includes a cost estimate and a preliminary construction timeline, establishing a framework for forthcoming engineering design phase and site selection procedures. Construction is anticipated to begin around 2027-2028, pending government approval, with an estimated duration of 8 years. The commencement of experiments could potentially initiate in the mid-2030s