Microscopy最新文献_第3页

TEM and STEM-EDS evaluation of metal nanoparticle encapsulation in GroEL/GroES complexes according to the reaction mechanism of chaperonin 根据伴侣蛋白的反应机理对GroEL/GroES复合物中金属纳米粒子包封的TEM和STEM-EDS评估

IF 1.8 4区工程技术

Microscopy Pub Date : 2021-06-01 DOI: 10.1093/jmicro/dfaa064

Hiromi Yoda;Ayumi Koike-Takeshita

{"title":"TEM and STEM-EDS evaluation of metal nanoparticle encapsulation in GroEL/GroES complexes according to the reaction mechanism of chaperonin","authors":"Hiromi Yoda;Ayumi Koike-Takeshita","doi":"10.1093/jmicro/dfaa064","DOIUrl":"10.1093/jmicro/dfaa064","url":null,"abstract":"Escherichia coli chaperonin GroEL, which is a large cylindrical protein complex comprising two heptameric rings with cavities of 4.5 nm each in the center, assists in intracellular protein folding with the aid of GroES and adenosine triphosphate (ATP). Here, we investigated the possibility that GroEL can also encapsulate metal nanoparticles (NPs) up to ∼5 nm in diameter into the cavities with the aid of GroES and ATP. The slow ATP-hydrolyzing GroEL\u0000<sup>D52A/D398A</sup>\u0000 mutant, which forms extremely stable complexes with GroES (half-time of ∼6 days), made it possible to analyze GroEL/GroES complexes containing metal NPs. Scanning transmission electron microscopy–energy-dispersive X-ray spectroscopy analysis proved distinctly that FePt NPs and Au NPs were encapsulated in the GroEL/GroES complexes. Dynamic light scattering measurements showed that the NPs in the GroEL/GroES complex were able to maintain their dispersibility in solution. We previously described that the incubation of GroEL and GroES in the presence of ATP·BeFx and adenosine diphosphate·BeFx resulted in the formation of symmetric football-shaped and asymmetric bullet-shaped complexes, respectively. Based on this knowledge, we successfully constructed the football-shaped complex in which two compartments were occupied by Pt or Au NPs (first compartment) and FePt NPs (second compartment). This study showed that metal NPs were sequentially encapsulated according to the GroEL reaction in a step-by-step manner. In light of these results, chaperonin can be used as a tool for handling nanomaterials.","PeriodicalId":18515,"journal":{"name":"Microscopy","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/jmicro/dfaa064","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38683554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Phase imaging dislocations using diffracted beam interferometry 用衍射束干涉法对位错进行相位成像

IF 1.8 4区工程技术

Microscopy Pub Date : 2021-06-01 DOI: 10.1093/jmicro/dfaa066

Rodney Herring

引用次数: 3

TEM observation of compacted DNA of Synechococcus elongatus PCC 7942 using DRAQ5 labeling with DAB photooxidation and osmium black DAB光氧化和锇黑DRAQ5标记细长聚球藻PCC 7942 DNA的透射电镜观察

IF 1.8 4区工程技术

Microscopy Pub Date : 2021-06-01 DOI: 10.1093/jmicro/dfaa058

Ilika Ghosh;Kimie Atsuzawa;Aoi Arai;Ryuzo Ohmukai;Yasuko Kaneko

引用次数: 1

Ultrastructural evidence for an unusual mode of ciliogenesis in mouse multiciliated epithelia 小鼠多纤毛上皮纤毛发生异常模式的超微结构证据

IF 1.8 4区工程技术

Microscopy Pub Date : 2021-06-01 DOI: 10.1093/jmicro/dfaa074

Keishi Narita;Sen Takeda

{"title":"Ultrastructural evidence for an unusual mode of ciliogenesis in mouse multiciliated epithelia","authors":"Keishi Narita;Sen Takeda","doi":"10.1093/jmicro/dfaa074","DOIUrl":"10.1093/jmicro/dfaa074","url":null,"abstract":"Multiciliogenesis is a cascading process for generating hundreds of motile cilia in single cells. In vertebrates, this process has been investigated in the ependyma of brain ventricles and the ciliated epithelia of the airway and oviduct. Although the early steps to amplify centrioles have been characterized in molecular detail, subsequent steps to establish multicilia have been relatively overlooked. Here, we focused on unusual cilia-related structures previously observed in wild-type mouse ependyma using transmission electron microscopy and analyzed their ultrastructural features and the frequency of their occurrence. In the ependyma, \u0000<tex>$sim$</tex>\u00005% of cilia existed as bundles; while the majority of the bundles were paired, bundles of more than three cilia were also found. Furthermore, apical protrusions harboring multiple sets of axonemes were occasionally observed (0–2 per section), suggesting an unusual mode of ciliogenesis. In trachea and oviduct epithelia, ciliary bundles were absent, but protrusions containing multiple axonemes were observed. At the base of such protrusions, certain axonemes were completely enwrapped by membranes, whereas others remained incompletely enwrapped. These data suggested that the late steps of multiciliogenesis might include a unique process underlying the development of cilia, which is distinct from the ciliogenesis of primary cilia.","PeriodicalId":18515,"journal":{"name":"Microscopy","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/jmicro/dfaa074","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38660318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Evaluation of depth of dislocation visibility in SEM electron channeling contrast imaging in Ti-6Al-4V alloy using serial sectioning method 用连续切片法评价Ti-6Al-4V合金SEM电子沟道对比成像中位错可见度的深度

IF 1.8 4区工程技术

Microscopy Pub Date : 2021-06-01 DOI: 10.1093/jmicro/dfaa060

Shigeto Yamasaki;Misaki Deguchi;Masatoshi Mitsuhara;Hideharu Nakashima;Yutaro Ota;Keiji Kubushiro

引用次数: 0

Photobleaching reduction in modulated super-resolution microscopy 调制超分辨率显微镜中的光漂白减少

IF 1.8 4区工程技术

Microscopy Pub Date : 2021-06-01 DOI: 10.1093/jmicro/dfaa062

Jafar H Ghithan;Jennifer M Noel;Thomas J Roussel;Maureen A McCall;Bruce W Alphenaar;Sergio B Mendes

{"title":"Photobleaching reduction in modulated super-resolution microscopy","authors":"Jafar H Ghithan;Jennifer M Noel;Thomas J Roussel;Maureen A McCall;Bruce W Alphenaar;Sergio B Mendes","doi":"10.1093/jmicro/dfaa062","DOIUrl":"10.1093/jmicro/dfaa062","url":null,"abstract":"Important breakthroughs in far-field imaging techniques have been made since the first demonstrations of stimulated emission depletion (STED) microscopy. To date, the most straightforward and widespread deployment of STED microscopy has used continuous wave (CW) laser beams for both the excitation and depletion of fluorescence emission. A major drawback of the CW STED imaging technique has been photobleaching effects due to the high optical power needed in the depletion beam to reach sub-diffraction resolution. To overcome this hurdle, we have applied a synchronous detection approach based on modulating the excitation laser beam, while keeping the depletion beam at CW operation, and frequency filtering the collected signal with a lock-in amplifier to record solely the super-resolved fluorescence emission. We demonstrate here that such approach allows an important reduction in the optical power of both laser beams that leads to measurable decreases in photobleaching effects in STED microscopy. We report super-resolution images with relatively low powers for both the excitation and depletion beams. In addition, typical unwanted scattering effects and background signal generated from the depletion beam, which invariably arises from mismatches in refractive index in the material composing the sample, are largely reduced by using the modulated STED approach. The capability of acquiring super-resolution images with relatively low power is quite relevant for studying a variety of samples, but particularly important for biological species as exemplified in this work.","PeriodicalId":18515,"journal":{"name":"Microscopy","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/jmicro/dfaa062","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38496307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Denoising of series electron holograms using tensor decomposition 用张量分解对串联电子全息图进行去噪

IF 1.8 4区工程技术

Microscopy Pub Date : 2021-06-01 DOI: 10.1093/jmicro/dfaa057

Yuki Nomura;Kazuo Yamamoto;Satoshi Anada;Tsukasa Hirayama;Emiko Igaki;Koh Saitoh

引用次数: 4

Effect of nitrogen-containing bisphosphonates on osteoclasts and osteoclastogenesis: an ultrastructural study 含氮双磷酸盐对破骨细胞和破骨细胞生成的影响：超微结构研究

IF 1.8 4区工程技术

Microscopy Pub Date : 2021-06-01 DOI: 10.1093/jmicro/dfaa073

Yoshitoki Takagi;Satoshi Inoue;Kaoru Fujikawa;Miwako Matsuki-Fukushima;Mitsuori Mayahara;Kayo Matsuyama;Yasuo Endo;Masanori Nakamura

{"title":"Effect of nitrogen-containing bisphosphonates on osteoclasts and osteoclastogenesis: an ultrastructural study","authors":"Yoshitoki Takagi;Satoshi Inoue;Kaoru Fujikawa;Miwako Matsuki-Fukushima;Mitsuori Mayahara;Kayo Matsuyama;Yasuo Endo;Masanori Nakamura","doi":"10.1093/jmicro/dfaa073","DOIUrl":"10.1093/jmicro/dfaa073","url":null,"abstract":"We have previously indicated that a single injection of alendronate, one of the nitrogen-containing bisphosphonates (NBPs), affects murine hematopoietic processes, such as the shift of erythropoiesis from bone marrow (BM) to spleen, disappearance of BM-resident macrophages, the increase of granulopoiesis in BM and an increase in the number of osteoclasts. NBPs induce apoptosis and the formation of giant osteoclasts in vitro and/or in patients undergoing long-term NBP treatment. Therefore, the time-kinetic effect of NBPs on osteoclasts needs to be clarified. In this study, we examined the effect of alendronate on mouse osteoclasts and osteoclastogenesis. One day after the treatment, osteoclasts lost the clear zone and ruffled borders, and the cell size decreased. After 2 days, the cytoplasm of osteoclasts became electron dense and the nuclei became pyknotic. Some of the cells had fragmented nuclei. After 4 days, osteoclasts had euchromatic nuclei attached to the bone surface. Osteoclasts had no clear zones or ruffled borders. After 7 days, osteoclasts formed giant osteoclasts via the fusion of multinuclear and mononuclear osteoclasts. These results indicate that NBPs affect osteoclasts and osteoclastogenesis via two different mechanisms.","PeriodicalId":18515,"journal":{"name":"Microscopy","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/jmicro/dfaa073","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38675525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Performance of a silicon-on-insulator direct electron detector in a low-voltage transmission electron microscope 低压透射电子显微镜中绝缘体上硅直接电子探测器的性能

IF 1.8 4区工程技术

Microscopy Pub Date : 2021-06-01 DOI: 10.1093/jmicro/dfaa072

Takafumi Ishida;Akira Shinozaki;Makoto Kuwahara;Toshinobu Miyoshi;Koh Saitoh;Yasuo Arai

引用次数: 1

Introduction to EBSD: Current Issues in Data Presentation. EBSD简介:数据表示中的当前问题。

IF 1.8 4区工程技术

Microscopy Pub Date : 2021-05-01 DOI: 10.2172/1870763

JosephTan Michael

引用次数: 0