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Vibrational spectroscopic imaging and live cell video microscopy for studying differentiation of primary human alveolar epithelial cells
摘要： Alveolar type II(ATII) cells in the peripheral human lung spontaneously differentiate towards alveolar type I(ATI) cells, thus enabling air-blood barrier formation. Here, linear Raman and coherent anti-Stokes Raman scattering (CARS) microscopy are applied to study cell differentiation of freshly isolated ATII cells. The Raman spectra can successfully be correlated to gradual morphological and molecular changes during cell differentiation. Alveolar surfactant rich vesicles in ATII cells are identified based on phospholipid vibrations, while ATI-like cells are characterized by the absence of vesicular structures. Complementary, CARS microscopy allows for 3D visualization of lipid vesicles within ATII cells and their secretion, while hyperspectral CARS enables the distinction between cellular proteins and lipids according to their vibrational signatures. This study paves the path for further label-free investigations of lung cells and the role of the pulmonary surfactant, thus also providing a basis for rational development of future lung therapeutics.
关键词： confocal laser scanning microscopy,confocal Raman microscopy,pneumocyte type II differentiation,CARS microscopy,cell imaging
更新于2025-09-23 15:23:52
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Manipulating Living Systems by Light; 生命現象の光操作技術の創出;
摘要： Complex gene networks are essential for diverse biological phenomena, such as cellular programming, metabolism, homeostasis, memory formation, and circadian rhythm. To understand these biological phenomena, including diseases, and to utilize or modify them, approaches that enable optical control of the genome are required. We developed new tools for targeted gene manipulation based on optical control of the CRISPR-Cas9 system and Cre-loxP system. These tools could greatly facilitate understanding of a variety of gene functions and prove useful in biomedical applications. Genome engineering technology and optogenetics technology have emerged as different technologies from each other so far. Our studies merge these emerging research fields together.
关键词： optogenetics,photoswitching protein,cell differentiation,Cre-loxP system,genome editing,CRISPR-Cas9 system
更新于2025-09-23 15:22:29
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Enhancement of osteoblast activity on nanostructured NiTi/hydroxyapatite coatings on additive manufactured NiTi metal implants by nanosecond pulsed laser sintering
摘要： Background: The osteoinductive behaviors of nitinol (NiTi)-based metal implants for bone regeneration are largely dependent on their surface composition and topology. Continuous-mode laser sintering often results in complete melting of the materials and aggregation of particles, which lack control of heat transfer, as well as microstructural changes during sintering of the nanocomposite materials. Methods: In the current study, in situ direct laser deposition was used to additively manufacture three-dimensional NiTi structures from Ni and Ti powders. The mechanical property of NiTi has been shown to be similar to bone. Nanosecond pulsed laser sintering process was then utilized to generate a nanoporous composite surface with NiTi alloy and hydroxyapatite (HA) by ultrafast laser heating and cooling of Ni, Ti, and HA nanoparticles mixtures precoated on the 3D NiTi substrates; HA was added in order to improve the biocompatibility of the alloy. We then studied the underlying mechanism in the formation of NiTi/HA nanocomposite, and the synergistic effect of the sintered HA component and the nanoporous topology of the composite coating. In addition, we examined the activity of bone-forming osteoblasts on the NiTi/HA surfaces. For this, osteoblast cell morphology and various biomarkers were examined to evaluate cellular activity and function. Results: We found that the nanoscale porosity delivered by nanosecond pulsed laser sintering and the HA component positively contributed to osteoblast differentiation, as indicated by an increase in the expression of collagen and alkaline phosphatase, both of which are necessary for osteoblast mineralization. In addition, we observed topological complexities which appeared to boost the activity of osteoblasts, including an increase in actin cytoskeletal structures and adhesion structures. Conclusion: These findings demonstrate that the pulsed laser sintering method is an effective tool to generate biocompatible coatings in complex alloy-composite material systems with desired composition and topology. Our findings also provide a better understanding of the osteoinductive behavior of the sintered nanocomposite coatings for use in orthopedic and bone regeneration applications.
关键词： metal implants,pulsed laser coating,biocompatibility,differentiation,bone regeneration,alkaline phosphatase,osteoinductive behavior
更新于2025-09-23 15:22:29
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White-light emissive upconversion nanoparticles for visual and colorimetric determination of the pesticide thiram
摘要： The authors describe the use of white-light emitting upconversion nanoparticles (WL-UCNPs) for visual detection of the pesticide thiram. The method is demonstrated to undergo a better discernable color change upon target binding. The WL-UCNPs are modified with the lead(II)-dithizone complex which acts as the energy acceptor and recognition unit. This leads to quenching of the blue (475 nm) and green (545 nm) emissions of the WL-UCNPs, while the red emission (650 nm) remains unaffected. Upon addition of thiram, the quenched emissions are recovered, with a linear signal increase in the range from 2 nM to 20 nM of thiram and a limit of detection of 0.26 nM. The nanoprobe was further integrated into a test paper for visual detection. The concentration-dependent color change that varies from red to cyan and bluish violet and then to white can be visually distinguished.
关键词： Lead-dithizone complex,Color-differentiation,Upconversional nanoprobe,Test paper,Energy transfer
更新于2025-09-23 15:22:29
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[IEEE 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Kyoto, Japan (2018.7.9-2018.7.13)] 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Experimental Definition of k-power of Pre-Exponential Voltage Factor for LAFE
摘要： In this work we used the possibilities of a comprehensive research methodology for LAFE. To determine the degree of the voltage in the pre-exponential factor, we used the IVC differentiation method and the method of minimization trend residue by variation Fowler-Nordheim coordinates. The method proved to be very sensitive to IVC bends and can serve as a characteristic for the homogeneity of LAFE arrays.
关键词： k-power,nanocomposite,field emission,carbon nanotubes,differentiation of current-voltage charateristics
更新于2025-09-23 15:21:21
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Modulation Properties of an Extended Cavity Diode Laser and Dynamic Mode Splitting
摘要： Low-dose CT (LDCT) images tend to be degraded by excessive mottle noise and steak artifacts. In this paper, we proposed a novel fractional-order differentiation model that can be applied to LDCT image processing as a post-processing technique. The anisotropic diffusion model (proposed by Perona and Malik, i.e., PM model) has good performance in flat regions, total variation (TV) model works better in edge preservation, and fractional-order differentiation models can mitigate block effect while preserving fine details and more structure. The proposed model is based on the weighted combinations of the fractional-order PM model and the fractional-order TV model, which maintains the advantages of PM model, TV model, and fractional-order differentiation models. Moreover, the local intensity variance was added to both weighted coefficient and diffusion coefficient of the proposed model to properly preserve edges and details. A variety of simulated phantom data, including the Shepp–Logan head phantom, the pelvis phantom, and the actual thoracic phantom, were used for experimental validation. The results of numerical simulation and clinical data experiments demonstrate that the proposed approach has a better performance in both noise suppression and detail preservation, when compared with several other existing methods.
关键词： edge and detail preservation,fractional-order differentiation model,Low-dose CT,image processing
更新于2025-09-23 15:21:01
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Bone quality assessment of osteogenic cell cultures by Raman microscopy
摘要： The use of autologous stem/progenitor cells represents a promising approach to the repair of craniofacial bone defects. The calvarium is recognized as a viable source of stem/progenitor cells that can be transplanted in vitro to form bone. However, it is unclear if bone formed in cell culture is similar in quality to that found in native bone. In this study, the quality of bone mineral formed in osteogenic cell cultures were compared against calvarial bone from postnatal mice. Given the spectroscopic resemblance that exists between cell and collagen spectra, the feasibility of extracting information on cell activity and bone matrix quality were also examined. Stem/progenitor cells isolated from fetal mouse calvaria were cultured onto fused‐quartz slides under osteogenic differentiation conditions for 28 days. At specific time intervals, slides were removed and analyzed by Raman microscopy and mineral staining techniques. We show that bone formed in culture at Day 28 resembled calvarial bone from 1‐day‐old postnatal mice with comparable mineralization, mineral crystallinity, and collagen crosslinks ratios. In contrast, bone formed at Day 28 contained a lower degree of ordered collagen fibrils compared with 1‐day‐old postnatal bone. Taken together, bone formed in osteogenic cell culture exhibited progressive matrix maturation and mineralization but could not fully replicate the high degree of collagen fibril order found in native bone.
关键词： Raman microscopy,osteogenic differentiation,tissue engineering,stem cells,bone quality
更新于2025-09-23 15:21:01
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Irradiation with blue light-emitting diode enhances osteogenic differentiation of stem cells from the apical papilla
摘要： This study aimed to evaluate the effects of low-energy blue LED irradiation on the osteogenic differentiation of stem cells from the apical papilla (SCAPs). SCAPs were derived from human tooth root tips and were irradiated with 0 (control group), 1 J/cm2, 2 J/cm2, 3 J/cm2, or 4 J/cm2 blue light in osteogenic induction medium. Cell proliferation was analyzed using the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. Osteogenic differentiation activity was evaluated by monitoring alkaline phosphatase (ALP), alizarin red staining, and real-time polymerase chain reaction (RT-PCR). The results of the MTT assay indicated that SCAPs in the LED groups exhibited a lower proliferation rate than those in the control group, and there were statistically differences between the 2 J/cm2, 3 J/cm2, and 4 J/cm2 groups and the control group (P < 0.05). The results of the ALP and alizarin red analyses showed that blue LED promoted osteogenic differentiation of the SCAPs. And 4 J/cm2 blue light upregulates the expression levels of the osteogenic/dentinogenic genes ALP, dentin sialophosphoprotein (DSPP), dentin matrix protein-1 (DMP-1), and osteocalcin (OCN) in SCAPs. Our results confirmed that low-energy blue LED at 1 J/cm2, 2 J/cm2, 3 J/cm2, and 4 J/cm2 could inhibit the proliferation of SCAPs and promotes osteogenic differentiation of SCAPs. Further in vitro studies are required to explore the mechanisms of the effects by low-energy blue LED.
关键词： Stem cells from apical papilla,Mesenchymal stem cells,Proliferation,Osteogenic differentiation,LED
更新于2025-09-23 15:19:57
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[IEEE 2019 19th International Workshop on Junction Technology (IWJT) - Kyoto, Japan (2019.6.6-2019.6.7)] 2019 19th International Workshop on Junction Technology (IWJT) - Aspects of Highly-channeled MeV Implants of Dopants in Si(100)
摘要： Low-dose CT (LDCT) images tend to be degraded by excessive mottle noise and steak artifacts. In this paper, we proposed a novel fractional-order differentiation model that can be applied to LDCT image processing as a post-processing technique. The anisotropic diffusion model (proposed by Perona and Malik, i.e., PM model) has good performance in flat regions, total variation (TV) model works better in edge preservation, and fractional-order differentiation models can mitigate block effect while preserving fine details and more structure. The proposed model is based on the weighted combinations of the fractional-order PM model and the fractional-order TV model, which maintains the advantages of PM model, TV model, and fractional-order differentiation models. Moreover, the local intensity variance was added to both weighted coefficient and diffusion coefficient of the proposed model to properly preserve edges and details. A variety of simulated phantom data, including the Shepp–Logan head phantom, the pelvis phantom, and the actual thoracic phantom, were used for experimental validation. The results of numerical simulation and clinical data experiments demonstrate that the proposed approach has a better performance in both noise suppression and detail preservation, when compared with several other existing methods.
关键词： image processing,edge and detail preservation,fractional-order differentiation model,Low-dose CT
更新于2025-09-23 15:19:57
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Pipeline Leak Detection Technology Based on Distributed Optical Fiber Acoustic Sensing System
摘要： Low-dose CT (LDCT) images tend to be degraded by excessive mottle noise and steak artifacts. In this paper, we proposed a novel fractional-order differentiation model that can be applied to LDCT image processing as a post-processing technique. The anisotropic diffusion model (proposed by Perona and Malik, i.e., PM model) has good performance in flat regions, total variation (TV) model works better in edge preservation, and fractional-order differentiation models can mitigate block effect while preserving fine details and more structure. The proposed model is based on the weighted combinations of the fractional-order PM model and the fractional-order TV model, which maintains the advantages of PM model, TV model, and fractional-order differentiation models. Moreover, the local intensity variance was added to both weighted coefficient and diffusion coefficient of the proposed model to properly preserve edges and details. A variety of simulated phantom data, including the Shepp–Logan head phantom, the pelvis phantom, and the actual thoracic phantom, were used for experimental validation. The results of numerical simulation and clinical data experiments demonstrate that the proposed approach has a better performance in both noise suppression and detail preservation, when compared with several other existing methods.
关键词： image processing,edge and detail preservation,fractional-order differentiation model,Low-dose CT
更新于2025-09-23 15:19:57