We report the development of a depth‐sensitive Raman spectroscopy system using the configuration of cone–shell excitation and cone detection. The system uses a 785 nm diode laser and three identical axicons for Raman excitation of the target sample in the form of a hollow conic section. The Raman scattered light from the sample, passed through the same (but solid) conic section, is collected for detection. Apart from its ability of probing larger depths (? few mm), an important attraction of the system is that the probing depths can be varied by simply varying the separation between axicons in the excitation arm. Furthermore, no adjustment is required in the sample arm, which is a significant advantage for noncontact, depth‐sensitive measurement. Evaluation of the performance of the developed setup on nonbiological phantom and biological tissue sample demonstrated its ability to recover Raman spectra of layers located at depths of ?2–3 mm beneath the surface.
Procedures for in vitro culturing of human primary keratinocytes from normal colon mucosa specimens have not been fully feasible, thus far. The protocol described herein allows primary keratinocytes from small tissue fragments of colorectal mucosa biopsies to grow in vitro. The procedure develops in three steps: (a) the enzymatic digestion of the tissue biopsy; (b) the use of cloning rings to purify primary keratinocyte colonies, (c) a defined keratinocyte medium to grow these cells in long-term culture. Our cultural method enables normal primary keratinocytes to be obtained by simple and rapid techniques. In our culture condition, primary keratinocytes express specific epithelial markers. Colorectal mucosa keratinocyte colonies require approximately 2 weeks to grow. Compared with previous approaches, our protocol provides a valuable model of study for human primary keratinocytes from normal colorectal (NCR) mucosa both at the cellular and molecular levels. It is well known, that different mutations occurring during the multistep process of carcinogenesis in the NCR mucosa, are strictly associated to the onset/progression of the colorectal carcinoma. On this ground, normal keratinocytes grown with our protocol, may represent an innovative tool to investigate the mechanisms that lead to colorectal carcinoma and other diseases. Our innovative procedure may allow to perform comparative investigations between normal and pathological colorectal cells.
Photodynamic inactivation of prions by disulfonated hydroxyaluminum phthalocyanine. Further details can be found in the article by Marie Kostelanska, Jaroslav Freisleben, Zdenka Backovska Hanusova, et al. ( e201800430 ).
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 ).
Cover Image The pollinators of Camellia pubipetala: sunbird Aethopyga christinae (left) and honeybee Apis cerana (right). Both pictures were taken by Sheng-feng Chai, at Longhushan, Jiangxi Province, China.
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 ).
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 ).
The nuclei of epithelial cells in stratified squamous epithelia have been reported to be either low scattering or high scattering. Using micro‐optical coherence tomography, we demonstrate that the nuclei are ‘low scattering’ in the core; those previously reported ‘high‐scattering’ signals are likely from the nucleocytoplasmic boundary. Further details can be found in the article by Si Chen, Xinyu Liu, Nanshuo Wang, et al. ( e201900073 ).
Front Cover: The cover image is based on the Research Article Transmembrane proteins—Different anchoring systems by Irena Roterman et al., https://doi.org/10.1002/prot.26646
To optimize the resection of gliomas during neurosurgery we present an imaging system capable of wide field fluorescence lifetime mapping with 11 mm field of view and 250 mm working distance. Based on a time of flight dual‐tap CMOS camera and a modulated laser at 405 nm we show unobserved quenching effects in tissue phantoms and demonstrate life‐time imaging on 5‐ALA labeled human ex vivo brain tumor samples. Further details can be found in the article by Mikael T. Erkkilä, Bianca Bauer, Nancy Hecker‐Denschlag, et al. ( e201800378 ).
A novel design of an SRS microscope exploiting spectral pulse shaping allows measurement of fingerprint to CH‐stretch SRS spectra without any modification of the optical setup. High spectral resolution over a broad vibrational range allows label‐free quantitative imaging of biological samples. An exemplary SRS broadband spectrum of lipid droplets in a liver cancer cell is shown in the picture. Further details can be found in the article by Sergey P. Laptenok, Vijayakumar P. Rajamanickam, Luca Genchi, et al. ( e201900028 ).
Fertile plants of Sargassum horneri with a lot of conspicuous, terete receptacles. Photo by Y. Homma, at Nezugaseki, Yamagata Prefecture in 17 June, 2018. See Watanabe et al. in this issue. Cover picture from: Article link here
Subaerial miroalgae form conspicuous biofilms on the bark surface of European beech trees (Fagus sylvatica) in temperate deciduous forests. ?tifterová and Neustupa investigated the variation in community structure of these covers on a small spatial scale. See ?tifterová and Neustupa in pages 299–311. Cover picture from: Article link here
The estimated life span of Halimeda from a new recruit to a fertile plant. See Mayakun and Prathep in this issue. Cover picture from: Article link here
An ultrafast time‐stretch imaging technique for edge detection is demonstrated. The edge detection based on the optical directional derivative is realized by using differential detection. Since the edge detection is implemented in the physical layer, the computation complexity in the back‐end digital signal processing is very low. The blood red cells and cancer cells can be easily identified by distinguishing the edges. Further details can be found in the article by Bo Dai, LuHe, Lulu Zheng, Yongfeng Fu et al. ( e201800044 ).
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 ).
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 ).
