Convolutional neural network assistance significantly improves dermatologists' diagnosis of cutaneous tumours using clinical images.

BACKGROUND: Convolutional neural networks (CNNs) have demonstrated expert-level performance in cutaneous tumour classification using clinical images, but most previous studies have focused on dermatologist-versus-CNN comparisons rather than their combination. The objective of our study was to evaluate the potential impact of CNN assistance on dermatologists for clinical image interpretation. METHODS: A multi-class CNN was trained and validated using a dataset of 25,773 clinical images comprising 10 categories of cutaneous tumours. The CNN's performance was tested on an independent dataset of 2107 images. A total of 400 images (40 per category) were randomly selected from the test dataset. A fully crossed, self-control, multi-reader multi-case (MRMC) study was conducted to compare the performance of 18 board-certified dermatologists (experience: 13/18 ≤ 10 years; 5/18＞10 years) in interpreting the 400 clinical images with or without CNN assistance. RESULTS: The CNN achieved an overall accuracy of 78.45% and kappa of 0.73 in the classification of 10 types of cutaneous tumours on 2107 images. CNN-assisted dermatologists achieved a higher accuracy (76.60% vs. 62.78%, P < 0.001) and kappa (0.74 vs. 0.59, P < 0.001) than unassisted dermatologists in interpreting the 400 clinical images. Dermatologists with less experience benefited more from CNN assistance. At the binary classification level (malignant or benign), the sensitivity (89.56% vs. 83.21%, P < 0.001) and specificity (87.90% vs. 80.92%, P < 0.001) of dermatologists with CNN assistance were also significantly improved than those without. CONCLUSIONS: CNN assistance improved dermatologist accuracy in interpreting cutaneous tumours and could further boost the acceptance of this new technique.

Selenium increases chlorogenic acid, chlorophyll and carotenoids of Lycium chinense leaves.

BACKGROUND: Leaves of Lycium chinense L. are widely used in traditional Chinese medicine and as functional food in China and south-east Asia. Polyphenols are important active compounds in leaves of L. chinense L, but their compositions are still not very clear. Selenium has been reported to increase some components of plants. In this study, the composition of polyphenols of L. chinense leaves were analysed, and the effects of selenium on the polyphenols and other components were studied. RESULTS: The main polyphenols were identified as rutin, chlorogenic acid, quercetin, kaempferol and apigenin-7-O-(6'-O-acetyl) glucose-rhamnose. Chlorogenic acid showed the highest average content of 78.36 g kg⁻¹. Rutin, quercetin and kaempferol were determined at low contents from 3.85 g kg⁻¹ to 7.08 g kg⁻¹. Correlation coefficients between selenium and chlorogenic acid, chlorophyll a, chlorophyll b and carotenoids were: R² = 0.963 (P = 0.002), 0.943 (P = 0.005), 0.957 (P = 0.003) and 0.943 (P = 0.005), respectively. Selenium (0.01-0.05 g kg⁻¹) significantly increased chlorogenic acid, chlorophyll and carotenoids by 200-400% and reduced rutin by 400-900%. CONCLUSION: L. chinense can be an alternative source of chlorogenic acid. Selenium significantly increased chlorogenic acid, chlorophyll a, chlorophyll b and carotenoids, hence increasing the medicinal value of L. chinense leaves. Rutin, quercetin, kaempferol and apigenin-7-O-(6'-O-acetyl) glucose-rhamnose proved to be not significantly influenced by selenium.

Mixing alternating copolymers containing fluorenyl groups with phospholipids to obtain Langmuir and Langmuir-Blodgett films.

The control of molecular architectures may be essential to optimize materials properties for producing luminescent devices from polymers, especially in the blue region of the spectrum. In this Article, we report on the fabrication of Langmuir-Blodgett (LB) films of polyfluorene copolymers mixed with the phospholipid dimyristoyl phosphatidic acid (DMPA). The copolymers poly(9,9-dioctylfluorene)-co-phenylene (copolymer 1) and poly(9,9-dioctylfluorene)-co-quaterphenylene) (copolymer 2) were synthesized via Suzuki reaction. Copolymer 1 could not form a monolayer on its own, but it yielded stable films when mixed with DMPA. In contrast, Langmuir monolayers could be formed from either the neat copolymer 2 or when mixed with DMPA. The surface pressure and surface potential measurements, in addition to Brewster angle microscopy, indicated that DMPA provided a suitable matrix for copolymer 1 to form a stable Langmuir film, amenable to transfer as LB films, while enhancing the ability of copolymer 2 to form LB films with enhanced emission, as indicated by fluorescence spectroscopy. Because a high emission was obtained with the mixed LB films and since the molecular-level interactions between the film components can be tuned by changing the experimental conditions to allow for further optimization, one may envisage applications of these films in optical devices such as organic light-emitting diodes (OLEDs).

Comparative investigations of genotoxic activity of five nitriles in the comet assay and the Ames test.

Two short-term assays, the modified Ames test and the comet assay, were carried out to evaluate the genotoxicity of five nitriles (acetonitrile, propionitrile, methacrylonitrile, butyronitrile, and benzonitrile). With the comet assay, all the nitriles studied were found to induce the genotoxicity in human lymphocytes and Hep G2 cells. Except for butyronitrile, the genotoxic potency in lymphocytes was more pronounced than that in Hep G2 cells, and the rank order of genotoxicity induced by these five nitriles in lymphocytes was different from that in Hep G2 cells, indicating that the pathways leading to genotoxicity in both types of cells were different. In the modified Ames test, no tested nitriles showed mutagenic activity on Salmonella typhimurium strain TA 98 and TA 100 with and without metabolic activation. Comparing the results obtained from both tests in this study, the comet assay seems to be more sensitive than the modified Ames test. Thus, the comet assay can be used to detect the genotoxicity of all nitriles.

Light emitting diodes containing Langmuir-Blodgett films of copolymer of a poly(p-phenylene-vinylene) derivative and poly(octaneoxide).

The properties of Langmuir and Langmuir-Blodgett (LB) films from a block copolymer with polyethylene oxide and phenylene-vinylene moieties are reported. The LB films were successfully transferred onto several types of substrates, with sufficient quality to allow for evaporation of a metallic electrode on top of the LB films to produce polymer light emitting diodes (PLEDs). The photoluminescence and electroluminescence spectra of the LB film and device were similar, featuring an emission at ca. 475 nm, from which we could infer that the emission mechanisms are essentially the same as in poly(p-phenylene) derivatives. Analogously to other PLEDs the current versus voltage characteristics of the LB-based device could be explained with the Arkhipov model according to which charge transport occurs among localized sites. The implications for nanotechnology of the level of control that may be achieved with LB devices will also be discussed.