This review is aimed at interpreting development and advantages of intravital imaging as an emerging invaluable methodology and summarizing related representative discoveries in bone physiologies and pathologies. It also indicates current limitations, further refinement, and extended application of intravital imaging in bone research. Further details can be found in the article by Yuhao Liu, Quan Yuan, and Shiwen Zhanget ( e201960075 ).
TP‐SAX microscopy images are shown in cyan, cyan hot, red, gray, and orange hot colors; TPFM images are in green color while the LSCM image is in magenta color. Our results show a spatial resolution enhancement for TP‐SAX (cyan image) even at 2.4 mm depth of a mouse brain in comparison with TPFM (green image) where scattering seriously degrades the PSF. Further details can be found in the article by Sandeep Chakraborty, Szu‐Yu Lee, Jye‐Chang Lee, Chen‐Tung Yen, and Chi‐Kuang Sun ( e201800136 ).
The tremendous enhancement factors possessed by surfaceenhanced Raman scattering (SERS), coupled with the flexibility of photonic crystal fibers (PCFs), pave the way to a new generation of ultrasensitive biosensors. This review article aims to provide the latest advancement in SERS‐based PCF sensors for various biochemical applications. Such a sensitive biosensor could be translated for the detection of biomarkers in body fluids for early diagnosis of diseases. Further details can be found in the article by U. S Dinish, Flavien Beffara, Georges Humbert, Jean‐Louis Auguste, and Malini Olivo ( e201900027 ).
A STED‐FLIM system is developed to observe the changes of fluorescence lifetime. The pictures show increased lifetime of fluorescent microspheres samples with laser illumination time in both confocal and STED imaging modes. Due to the saturation power of fluorophores is correlated with fluorescence lifetime, the lifetime increase is beneficial for the reduction of the saturation power, indicating the same imaging resolution can be achieved in a lower depletion power. Further details can be found in the article by Lu‐Wei Wang, Yue Chen, Wei Yan, et al. ( e201800315 ).
Monitoring the blood‐brain barrier (BBB) permeability plays a key role in assessing drug release with high resolution. In this work, with the help of optical clearing skull window, we not only realized non‐invasive BBB opening by photodynamic therapy, but also developed a method based on spectral‐imaging to in vivo dynamically monitor the changes in BBB permeability. Further details can be found in the article by Wei Feng, Chao Zhang, Tingting Yu, et al. ( e201800330 ).
Cover Image A large population (left) and various life history stages (right), e.g. seedling, one-leaf, three-leaved and flowering, of Trillium camschatcense. (cf. Ohara & Kawano, 2005, Plant Species Biology 20:75–82, DOI: 10.1111/j.1442-1984.2005.00126.x ) Photographed by Masashi Ohara, Tokachi, Hokkaido, Japan.
Spectra from microscopic tissue sections are strongly distorted by Mie‐type scattering and require correction by the ME‐EMSC algorithm. In the upper right, Mie extinction curves, which are simulated by the ME‐EMSC algorithm, are shown. Two measured spectra are shown in the foreground, a raw spectrum which contains Mie scattering, and the spectrum corrected by the ME‐EMSC algorithm. The cover figure was designed by Dr. Boris Zimmermann. Further details can be found in the article by Johanne H. Solheim, Evgeniy Gunko, Dennis Petersen, et al. ( e201800415 ).
Hyperspectral scanning laser optical tomography is developed to provide spectrally resolved volume data sets with high spectral resolution for large mesoscopic samples. It can be used to resolve largely overlapping fluorophores, as demonstrated by the 3D fluorescence hyperspectral reconstruction of a dual‐labelled mouse thymus gland sample and to distinguish between signals from autofluorescence of diseased and normal tissue without prior knowledge. Further details can be found in the article by Lingling Chen, Guiye Li, Li Tang, et al. ( e201800221 ).
Nuclear pore complex imaged at three different resolutions by confocal, expansion, and Ex‐STED microscopy, respectively. NUP become a ruler to measure the expansion process. Further details can be found in the article by Luca Pesce, Marco Cozzolino, Luca Lanzanò, Alberto Diaspro, and Paolo Bianchini ( e201900018 ).
This schematic depicts the classification of multiphoton images with different degrees of HCC differentiation using the VGG‐16 neural network. The convolution layer is further trained based on the original weights. The weights of the fully connected layers are initialized as a random number and the training is restarted to improve its classification accuracy. Further details can be found in the article by Hongxin Lin, Chao Wei, Guangxing Wang, et al. ( e201800435 ).
Infrared attenuated total reflection spectroscopy is an emerging label‐free method for analyzing the degree of damage in cartilage samples. In the present study, sheep menisci have been characterized after meniscectomy via the variances of relevant biomolecules at the incision surface. Further details can be found in the article by Angela I. López‐Lorente et al. ( e201800429 ).
Sub‐picosecond light pulses are used to launch high‐frequency ultrasound in cells. The dual detection of acoustic echoes and of the time‐domain Brillouin scattering allows mapping remotely and in a single run experiment the cell adhesion, thickness, storage modulus and mass density, all with micron resolution. The dual picosecond opto‐acoustic microscope is demonstrated with the multiple imaging of a mitotic macrophage‐like cell. This novel modality is compatible with simultaneous fluorescence imaging. Further details can be found in the article by Liwang Liu, Laurent Plawinski, Marie‐Christine Durrieu, Bertrand Audoin ( e201900045 ).
A new quantitative phase imaging (QPI) modality, coined multi‐ATOM, can now capture and process enormous amount of quantitative phase single‐cell images (>700,000 cells) at a ultrahigh throughput without compromising sub‐cellular resolution. It could empower label‐free single‐cell analysis where large‐scale and cost‐effective screening is necessary. Further details can be found in the article by Kelvin C. M. Lee, Andy K. S. Lau, Anson H. L. Tang, et al. ( e201800479 ).
Laser tweezers Raman spectroscopy as a label‐free and non‐invasive technology was employed to examine the colon cancer cells with single base mutation in KRAS gene segment for the first time. As a result of the comparison, a high correct classification was achieved. Our preliminary results showed that the LTRS system has a great potential for further applications in the rapid and label‐free detection of circulating tumor cells in liquid biopsy. Further details can be found in the article by Mengmeng Liu, Xiujie Liu, Zufang Huang, et al. ( e201800332 ).
Thrombosis monitoring in vivo in small animals is of great value in basic research. The aim of this study is to utilize OCT to monitor thrombosis progression in femoral vein of mice from various measurement criteria, and to validate its use in evaluation the efficacy of the antithrombotic drug. The proved capability of obtaining thrombodynamics information in mice model provide valuable use in preclinical studies for anti‐thrombotic drugs development research. Further details can be found in the article by Yao Yu, Menghan Yu, Jian Liu, et al. ( e201900105 ).
A fast polarization‐resolved second harmonic generation microscope is implemented to map collagen orientation in thick and deforming tissues during mechanical assays. This system is based on line‐to‐line switching of the laser polarization using an electro‐optical modulator and works in epi‐detection geometry. After proper calibration, it successfully highlights the collagen dynamic alignment along the traction direction in ex vivo murine skin dermis. Further details can be found in the article by Guillaume Ducourthial, Jean‐Sébastien Affagard, Margaux Schmeltz, et al. ( e201800336 ).
Label‐free optical projection tomography technique makes it possible for quantitative whole mouse embryo imaging without any exogenous contrast agent. Further details can be found in the article by Sungbea Ban, Nam Hyun Cho, Eunjung Min, et al. ( e201800481 ).
There is a clinical need in the treatment of atrial fibrillation by radiofrequency ablation to provide lesion set validation. The integration of optical fibers into radiofrequency ablation catheters can address this issue. Thermally‐induced, dynamic changes in tissue diffuse reflectance are measured through transcatheter near‐infrared spectroscopy. A regression model based on spectral features is proposed and utilized to validate the presence of thermal injury, measure lesion depth, and assess gaps. Further details can be found in the article by Rajinder P. Singh‐Moon, Xinwen Yao, Vivek Iyer, et al. ( e201800144 ).
In this work, intravital multiphoton microscopy was used to image and quantify hepatobiliary metabolism of 6‐carboxyfluorescein diacetate in the recovery of acetaminophen‐overdose mice. It was found that the excretion of the probe molecule was time‐dependent and hepatobiliary metabolism is higher in recovered mice, suggesting that newly regenerated hepatocytes have higher metabolic capabilities. This approach may be further developed applied to studying drug‐induced hepatotoxicity in vivo. Further details can be found in the article by Feng‐Chieh Li, Sheng‐Lin Lee, Hung‐Ming Lin, et al. ( e201800296 ).
A large‐depth‐of‐field full‐field optical angiography (LD‐FFOA) method is developed to expand the depth‐of‐field (DOF). The contrast pyramid fusion algorithm is used to fuse 10 FFOA images at different focus depth. Cover images of mouse ear shows LD‐FFOA image has higher contrast and more detailed features. The LD‐FFOA method solves the defocused problem caused by the limited DOF of lens, the curved surface and uneven thickness of the sample. Further details can be found in the article by Mingyi Wang, Nanshou Wu, Hongheng Huang, et al. ( e201800329 ).
