Low light often leads to poor image visibility, which can easily affect the performance of computer vision algorithms. First, this paper proposes the absorption light scattering model (ALSM), which ...can be used to reasonably explain the absorbed light imaging process for low-light images. In addition, the absorbing light scattering image obtained via ALSM under a sufficient and uniform illumination can reproduce hidden outlines and details from the low-light image. Then, we identify that the minimum channel of ALSM obtained above exhibits high local similarity. This similarity can be constrained by superpixels, which effectively prevent the use of gradient operations at the edges so that the noise is not amplified quickly during enhancement. Finally, by analyzing the monotonicity between the scene reflection and the atmospheric light or transmittance in ALSM, a new low-light image enhancement method is identified. We replace atmospheric light with inverted atmospheric light to reduce the contribution of atmospheric light in the imaging results. Moreover, a soft jointed mean-standard-deviation (MSD) mechanism is proposed that directly acts on the patches represented by the superpixels. The MSD can obtain a smaller transmittance than that obtained by the minimum strategy, and it can be automatically adjusted according to the information of the image. The experiments on challenging low-light images are conducted to reveal the advantages of our method compared with other powerful techniques.
•Scattered Light Imaging (SLI) reveals individual nerve fiber directions in the brain.•The simple prototypic setup contains only a standard LED light source and a camera.•SLI reconstructs multiple ...crossing nerve fiber directions within each image pixel.•We measured various brain sections (rodent/monkey/human) with micrometer resolution.•We validated our results against simulated/measured scattering patterns and 3D-PLI.
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For developing a detailed network model of the brain based on image reconstructions, it is necessary to spatially resolve crossing nerve fibers. The accuracy hereby depends on many factors, including the spatial resolution of the imaging technique. 3D Polarized Light Imaging (3D-PLI) allows the three-dimensional reconstruction of nerve fiber tracts in whole brain sections with micrometer in-plane resolution, but leaves uncertainties in pixels containing crossing fibers. Here we introduce Scattered Light Imaging (SLI) to resolve the substructure of nerve fiber crossings. The measurement is performed on the same unstained histological brain sections as in 3D-PLI. By illuminating the brain sections from different angles and measuring the transmitted (scattered) light under normal incidence, light intensity profiles are obtained that are characteristic for the underlying brain tissue structure. We have developed a fully automated evaluation of the intensity profiles, allowing the user to extract various characteristics, like the individual directions of in-plane crossing nerve fibers, for each image pixel at once. We validate the reconstructed nerve fiber directions against results from previous simulation studies, scatterometry measurements, and fiber directions obtained from 3D-PLI. We demonstrate in different brain samples (human optic tracts, vervet monkey brain, rat brain) that the 2D fiber directions can be reliably reconstructed for up to three crossing nerve fiber bundles in each image pixel with an in-plane resolution of up to 6.5 μm. We show that SLI also yields reliable fiber directions in brain regions with low 3D-PLI signals coming from regions with a low density of myelinated nerve fibers or out-of-plane fibers. This makes Scattered Light Imaging a promising new imaging technique, providing crucial information about the organization of crossing nerve fibers in the brain.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Gold nanoflowers (GNFs) exhibit stronger light scattering ability than gold nanospheres (GNSs) with the same diameter, thereby contributing to enhancing the sensitivity of the scattering-based ...sensing method. However, the application of GNFs in biosensors based on dynamic light scattering (DLS) has not been yet reported. Herein, we describe for the first time an improved no-wash immunosensor based on dynamic light scattering for the detection of Escherichia coli O157:H7 (E. coli O157:H7) in milk using GNFs for sensitive signal transduction. To achieve this goal, a thiolated amphiphilic carboxyl ligand was introduced to modify the GNF surface and improve solution stability and antibody functionalization. Several key factors that affect the detection sensitivity of our developed GNF_DLS immunosensor were systematically investigated. Under the optimal conditions, our proposed GNF_DLS immunosensor provided an excellent linear detection for E. coli O157:H7 within the range from 6 × 100 to 6 × 104 colony-forming units (CFU)/mL, with a limit of detection of 2.7 CFU/mL. Combined with our previously reported two-step large-volume immunomagnetic separation (IMS) method, the designed GNF_DLS immunosensor can sensitively, selectively, and accurately detect the presence of E. coli O157:H7 in pasteurized milk. The potential of our GNF_DLS method for monitoring the presence of a single bacterial cell in 1 mL of sample solution was also demonstrated. Overall, the developed GNF_DLS immunosensor can be used for the rapid and high-sensitivity determination of pathogenic bacteria and can be extended for the ultrasensitive no-wash detection of other trace analytes.
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IJS, KILJ, NUK, PNG, UL, UM, UPUK
We established an experimental apparatus by combining polarized light scattering and angle-resolved light scattering measurement technology to rapidly identify the shape of an individual aerosol ...particle. The experimental data of scattered light of Oleic acid, rod-shaped Silicon dioxide, and other particles with typical shape characteristics were analyzed statistically. To better study the relationship between the shape of particles and the properties of scattered light, the partial least squares discriminant analysis (PLS-DA) method was used to analyze the scattered light of aerosol samples based on the size screening of particles, and the shape recognition and classification method of the individual aerosol particle was established based on the analysis of the spectral data after nonlinear processing and grouping by particle size with the area under the receiver operating characteristic curve (AUC) as reference. The experimental results show that the proposed classification method has a good discrimination ability for spherical, rod-shaped, and other non-spherical particles, which can provide more information for atmospheric aerosol measurement, and has application value for traceability and exposure hazard assessment of aerosol particles.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
An improved HPLC–ELSD method has been developed for the analysis of the lipid classes of buttermilk and milk from different species, focused in the phospholipids fraction without a prior ...fractionation step and in a single run. The total lipid profile analysis showed the major and minor lipid compounds as cholesterol esters, triacylglycerides, cholesterol, diacylglycerides, free fatty acids, monoacylglycerides, and also the polar compounds as glucosylceramide, lactosylceramide, phosphatidyl-ethanolamine, phosphatidylinositol, phosphatidylserine, phosphatidylcholine, sphingomyelin and lysophosphatidylcholine. The identification and quantification of the different compounds, using calibration curves made with individual standards and the low coefficients of variation obtained in the inter- and intra-assays showed the suitability of the developed method. In this study, we optimized and validated a quantitative HPLC–ELSD method at a concentration level suitable for routine analysis of the major lipid classes in milk and dairy products.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Myosin from bighead carp (Aristichthys nobilis) as a main type of fish protein possesses a good emulsifying ability. However, whether bighead carp myosin (BCM) could construct stable Pickering ...emulsions is still unclear. Therefore, myosin particles and Pickering emulsions stabilized by bighead carp myosin (BCMPEs) were analyzed. The surface structure of BCM particles at 0.6 mol/L NaCl treatment was uniform and compact with a contact angle of 86.4 ± 2.7°, exhibiting the potential ability to construct O/W Pickering emulsions. The size and flocculation index (FI) of BCMPEs decreased with the increase in BCM concentrations of 1%–4% (w/v). Reversely, the size of BCMPEs increased with the increase in oil-water ratios. BCM particles could uniformly distribute at the oil-water interface to stabilize BCMPEs at a BCM concentration of 4% (w/v) and an oil-water ratio of 6:4 (v/v). This study could help explore fish proteins to construct Pickering emulsions for the deep processing of fish products.
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•BCM particles at 0.6 mol/L NaCl exhibited the potential to construct Pickering emulsions.•BCM particles uniformly distributed at the oil-water interface of Pickering emulsions.•BCMPEs exhibited good stability at a BCM concentration of 4% (w/v) and an oil-water ratio of 6:4 (v/v).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Reentrant phenomenon of BSA coexistence of monovalent cation Na+.•Scattering measurements result phase diagrams of BSA aqueous solution for dissolve/sedimentation/reentrant region.•Coexistence of ...Na+, sedimentation region was narrower but attractive force inter BSA became stronger.
In an aqueous solution, certain charged proteins, which can be seen as macroions, often undergo reentrant condensation in the presence of salt. These macroions aggregate upon adding salt at a specific concentration, and further addition of salt leads to the dissociation of the aggregates. For bovine serum albumin (BSA), it has found that the reentrant phenomenon is caused by YCl3 Zhang et al. 2008. Fujihara and Akiyama have theoretically predicted that the attractive interaction between like-charged macroions induced by coexisting multivalent ions such as Y3+ is weakened by the addition of monovalent ions such as Na+ Fujihara et al.2014. In this paper, the impact of Na+ on the reentrant condensation of BSA in aqueous media is investigated by static light scattering (SLS) measurements. The phase diagram for the reentrant condensation of BSA reveals that the sedimentation range becomes narrow when Na+ is co-added, indicating that the coexistence of monovalent ions suppresses the attractive interaction between BSA induced by Y3+.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Streptococcus pneumoniae
is a highly invasive bacterial pathogen that can cause a range of illnesses. Pneumococcal capsular polysaccharides (CPS) are the main virulence factors that causes invasive ...pneumococcal disease (IPD). Pneumococcal CPS serotype 7F along with a few other serotypes is more invasive and likely to cause IPD. Therefore, 7F is a target for pneumococcal vaccine development, and is included in the two recently approved multi-valent pneumococcal conjugated vaccines, i.e. VAXNEUVANCE and PREVNAR 20.
To support process and development of our 15-valent pneumococcal conjugated vaccine (PCV15), chromatographic methods have been developed for 7F polysaccharide and conjugate characterization. A size-exclusion chromatography (SEC) method with UV, light scattering and refractive index detections was employed for concentration, size and conformation analysis. A reversed-phase ultra-performance liquid chromatography (RP-UPLC) method was used for analysis of conjugate monosaccharide composition and degree of conjugation. The collective information obtained by these chromatographic analysis provided insights into the pneumococcal conjugate and conjugation process.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Cell identification and analysis play a crucial role in many biology- and health-related applications. The internal and surface structures of a cell are complex and many of the features are ...sub-micron in scale. Well-resolved images of these features cannot be obtained using optical microscopy. Previous studies have reported that the single-cell angular laser-light scattering patterns (ALSP) can be used for label-free cell identification and analysis. The ALSP can be affected by cell properties and the wavelength of the probing laser. Two cell properties, cell surface roughness and the number of mitochondria, are investigated in this study. The effects of probing laser wavelengths (blue, green, and red) and the directions of scattered light collection (forward, side, and backward) are studied to determine the optimum conditions for distinguishing the two cell properties. Machine learning (ML) analysis has been applied to ALSP obtained from numerical simulations. The results of ML analysis show that the backward scattering is the best direction for characterizing the surface roughness, while the forward scattering is the best direction for differentiating the number of mitochondria. The laser light having red or green wavelength is found to perform better than that having the blue wavelength in differentiating the surface roughness and the number of mitochondria. This study provides important insights into the effects of probing laser wavelength on gaining information about cells from their ALSP. This article is protected by copyright. All rights reserved.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
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