6 research outputs found
DRAC: Diabetic Retinopathy Analysis Challenge with Ultra-Wide Optical Coherence Tomography Angiography Images
Computer-assisted automatic analysis of diabetic retinopathy (DR) is of great
importance in reducing the risks of vision loss and even blindness. Ultra-wide
optical coherence tomography angiography (UW-OCTA) is a non-invasive and safe
imaging modality in DR diagnosis system, but there is a lack of publicly
available benchmarks for model development and evaluation. To promote further
research and scientific benchmarking for diabetic retinopathy analysis using
UW-OCTA images, we organized a challenge named "DRAC - Diabetic Retinopathy
Analysis Challenge" in conjunction with the 25th International Conference on
Medical Image Computing and Computer Assisted Intervention (MICCAI 2022). The
challenge consists of three tasks: segmentation of DR lesions, image quality
assessment and DR grading. The scientific community responded positively to the
challenge, with 11, 12, and 13 teams from geographically diverse institutes
submitting different solutions in these three tasks, respectively. This paper
presents a summary and analysis of the top-performing solutions and results for
each task of the challenge. The obtained results from top algorithms indicate
the importance of data augmentation, model architecture and ensemble of
networks in improving the performance of deep learning models. These findings
have the potential to enable new developments in diabetic retinopathy analysis.
The challenge remains open for post-challenge registrations and submissions for
benchmarking future methodology developments
Metasurface spectrometers beyond resolution-sensitivity constraints
Optical spectroscopy plays an essential role across scientific research and
industry for non-contact materials analysis1-3, increasingly through in-situ or
portable platforms4-6. However, when considering low-light-level applications,
conventional spectrometer designs necessitate a compromise between their
resolution and sensitivity7,8, especially as device and detector dimensions are
scaled down. Here, we report on a miniaturizable spectrometer platform where
light throughput onto the detector is instead enhanced as the resolution is
increased. This planar, CMOS-compatible platform is based around metasurface
encoders designed to exhibit photonic bound states in the continuum9, where
operational range can be altered or extended simply through adjusting geometric
parameters. This system can enhance photon collection efficiency by up to two
orders of magnitude versus conventional designs; we demonstrate this
sensitivity advantage through ultra-low-intensity fluorescent and astrophotonic
spectroscopy. This work represents a step forward for the practical utility of
spectrometers, affording a route to integrated, chip-based devices that
maintain high resolution and SNR without requiring prohibitively long
integration times
The Regulating Effect of CII-3 and Its Active Components from Periplaneta americana on M1/M2 Macrophage Polarization
CII-3 is the effective part of Periplaneta americana for application in oncotherapy. This study investigated its main chemical components for macrophage polarization regulation activity. Compounds were separated and purified, and their structures were elucidated based on NMR and HR-ESI-MS analyses. After inducing the M1 and M2 phenotype macrophages, CII-3 and testing components were added and co-incubated to evaluate their effects on the relevant markers of macrophages. Then, gradient concentrations of CII-3 and active monomers were further investigated for their effects on M2 macrophages. The effects were detected by RT-PCR, ELISA, flow cytometry, and immunofluorescence. Twelve compounds were identified from CII-3. CII-3 and pericanaside (5) had no obvious effect on M1 macrophages, while they significantly reduced the expression levels of M2 macrophage markers. Specifically, they significantly reduced the levels of TGF-β and IL-10 and the mRNA expression levels of ARG-1 and CD206 in the M2 phenotypes of RAW264.7 and Ana-1 macrophages. The conditioned medium of CII-3 and pericanaside (5) could inhibit the migration capacity of CT26.WT tumor cells. Macrophage M1/M2 polarization is a dynamic equilibrium, and the M2 phenotype, which can promote the growth of tumor cells, is relatively highly expressed in the tumor microenvironment. CII-3 and pericanaside could significantly reduce the phenotype of M2-type macrophages, indicating that the anti-tumor activity of CII-3 could be related to the inhibitory effect on M2 polarization, and pericanaside was one of the active components
Diverse Secondary Metabolites from the Coral-Derived Fungus Aspergillus hiratsukae SCSIO 5Bn1003
Three new metabolites, including a cyclic tetrapeptide asperhiratide (1), an ecdysteroid derivative asperhiratine (2), and a sesquiterpene lactone asperhiratone (3), were isolated and identified from the soft coral-derived fungus Aspergillus hiratsukae SCSIO 5Bn1003, together with 10 known compounds. Their structures were elucidated via spectroscopic analysis, X-ray diffraction analysis, and electronic circular dichroism calculations. In addition, the absolute configuration of 1 was determined by Marfey’s technique and an analysis of the acid hydrolysates using a chiral phase HPLC column. Among all the compounds, 6 and 8 showed medium cytotoxic activities against four tumor cell lines (SF-268, HepG-2, MCF-7, and A549), with IC50 values ranging from 31.03 ± 3.04 to 50.25 ± 0.54 µM. Meanwhile, they strongly inhibited α-glucosidase activities, with IC50 values of 35.73 ± 3.94 and 22.00 ± 2.45 µM, which were close to and even stronger than the positive control acarbose (IC50 = 32.92 ± 1.03 µM). Compounds 6–8 showed significant antibacterial activities against Bacillus subtilis, with MIC values of 10.26 ± 0.76 µM, 17.00 ± 1.25 µM, and 5.30 ± 0.29 µM, respectively. Compounds 9 and 12 exhibited potent radical scavenging activities against DPPH, with IC50 values of 12.23 ± 0.78 µM and 7.38 ± 1.16 µM. In addition, asperhiratide (1) was evaluated for anti-angiogenic activities in the in vivo zebrafish model, which showed a weak inhibitory effect on intersegmental vessel (ISV) formation
Synthesis of novel 18<i>β</i>-glycyrrhetinic acid sulfonate derivatives displaying significant anti-oomycete activity against <i>Phytophthora capsici</i>
Using 18β-glycyrrhetinic acid (GA) as the lead compound, fourteen GA sulphonate derivatives (3a–n) were prepared by modifying its C-3 OH group, and their structures were well confirmed by 1H NMR, 13C NMR, HRMS and melting points. Moreover, we screened the anti-oomycete activity of these compounds against Phytophthora capsici by using the mycelial growth rate method. Among the fourteen GA sulphonate derivatives evaluated, four compounds 3f, 3j, 3k and 3l exhibited more potent anti-oomycete activity than that of the positive control zoxamide (EC50 = 25.17 mg/L), and had the median effective concentration (EC50) values of 23.04, 16.16, 22.55, and 13.93 mg/L, respectively. Especially compound 3l showed the best anti-oomycete activity against P. capsici with EC50 value of 13.93 mg/L. Overall, the introduction of sulfonyloxy groups at the C-3 position of GA has a significant impact on its anti-oomycete activity, and the corresponding derivative activity varies significantly with different substituents R.</p
Metasurface spectrometers beyond resolution-sensitivity constraints
Optical spectroscopy plays an essential role across scientific research and industry for non-contact materials analysis1-3, increasingly through in-situ or portable platforms4-6. However, when considering low-light-level applications, conventional spectrometer designs necessitate a compromise between their resolution and sensitivity7,8, especially as device and detector dimensions are scaled down. Here, we report on a miniaturizable spectrometer platform where light throughput onto the detector is instead enhanced as the resolution is increased. This planar, CMOS-compatible platform is based around metasurface encoders designed to exhibit photonic bound states in the continuum9, where operational range can be altered or extended simply through adjusting geometric parameters. This system can enhance photon collection efficiency by up to two orders of magnitude versus conventional designs; we demonstrate this sensitivity advantage through ultra-low-intensity fluorescent and astrophotonic spectroscopy. This work represents a step forward for the practical utility of spectrometers, affording a route to integrated, chip-based devices that maintain high resolution and SNR without requiring prohibitively long integration times