Nikita S Dutta, Gerard Michael Carroll, Nathan R Neale, Sang-Don Han, Mowafak Al-Jassim, Katherine Jungjohann
Understanding structural and chemical evolution of battery materials during operation is critical to achieving safe, efficient, and long-lasting energy storage. Cryogenic electron microscopy (cryo-EM) has become a valuable tool in battery characterization, leveraging low temperatures to improve stability of sensitive materials under electron beam irradiation. However, typical cryo-EM sample preparations leave extended time between the electrochemical point of interest and ex situ freezing of samples, during which active structures may relax, degrade, or otherwise evolve. Here, we detail a method for operando freezing cryo-EM to preserve and characterize native electrode and interfacial structures that arise during battery cycling, based on an operando plunge freezer and cold sample removal process. We validate the method on multiple electrode materials and quantify and discuss the freezing rate achieved. Operando freezing cryo-EM can be used to directly visualize transient features that arise at active electrochemical interfaces, to enable deeper understanding of structural evolution and interfacial chemistry in batteries and other electrochemical systems.
{"title":"Operando Freezing Cryogenic Electron Microscopy of Active Battery Materials.","authors":"Nikita S Dutta, Gerard Michael Carroll, Nathan R Neale, Sang-Don Han, Mowafak Al-Jassim, Katherine Jungjohann","doi":"10.1093/mam/ozae097","DOIUrl":"https://doi.org/10.1093/mam/ozae097","url":null,"abstract":"<p><p>Understanding structural and chemical evolution of battery materials during operation is critical to achieving safe, efficient, and long-lasting energy storage. Cryogenic electron microscopy (cryo-EM) has become a valuable tool in battery characterization, leveraging low temperatures to improve stability of sensitive materials under electron beam irradiation. However, typical cryo-EM sample preparations leave extended time between the electrochemical point of interest and ex situ freezing of samples, during which active structures may relax, degrade, or otherwise evolve. Here, we detail a method for operando freezing cryo-EM to preserve and characterize native electrode and interfacial structures that arise during battery cycling, based on an operando plunge freezer and cold sample removal process. We validate the method on multiple electrode materials and quantify and discuss the freezing rate achieved. Operando freezing cryo-EM can be used to directly visualize transient features that arise at active electrochemical interfaces, to enable deeper understanding of structural evolution and interfacial chemistry in batteries and other electrochemical systems.</p>","PeriodicalId":18625,"journal":{"name":"Microscopy and Microanalysis","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142381264","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}
Robert Busch, Hsu-Chih Ni, Yu-Tsun Shao, Jian-Min Zuo
We report a large-angle rocking beam electron diffraction (LARBED) technique for electron diffraction analysis. Diffraction patterns are recorded in a scanning transmission electron microscope (STEM) using a direct electron detector with large dynamical range and fast readout. We use a nanobeam for diffraction and perform the beam double rocking by synchronizing the detector with the STEM scan coils for the recording. Using this approach, large-angle convergent beam electron diffraction (LACBED) patterns of different reflections are obtained simultaneously. By using a nanobeam, instead of a focused beam, the LARBED technique can be applied to beam-sensitive crystals as well as crystals with large unit cells. This paper describes the implementation of LARBED and evaluates the performance using silicon and gadolinium gallium garnet crystals as test samples. We demonstrate that our method provides an effective and robust way for recording LARBED patterns and paves the way for quantitative electron diffraction of large unit cell and beam-sensitive crystals.
{"title":"Large-Angle Rocking Beam Electron Diffraction of Large Unit Cell Crystals Using Direct Electron Detector.","authors":"Robert Busch, Hsu-Chih Ni, Yu-Tsun Shao, Jian-Min Zuo","doi":"10.1093/mam/ozae088","DOIUrl":"https://doi.org/10.1093/mam/ozae088","url":null,"abstract":"<p><p>We report a large-angle rocking beam electron diffraction (LARBED) technique for electron diffraction analysis. Diffraction patterns are recorded in a scanning transmission electron microscope (STEM) using a direct electron detector with large dynamical range and fast readout. We use a nanobeam for diffraction and perform the beam double rocking by synchronizing the detector with the STEM scan coils for the recording. Using this approach, large-angle convergent beam electron diffraction (LACBED) patterns of different reflections are obtained simultaneously. By using a nanobeam, instead of a focused beam, the LARBED technique can be applied to beam-sensitive crystals as well as crystals with large unit cells. This paper describes the implementation of LARBED and evaluates the performance using silicon and gadolinium gallium garnet crystals as test samples. We demonstrate that our method provides an effective and robust way for recording LARBED patterns and paves the way for quantitative electron diffraction of large unit cell and beam-sensitive crystals.</p>","PeriodicalId":18625,"journal":{"name":"Microscopy and Microanalysis","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142365821","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}
Tom Stoops, Annick De Backer, Ivan Lobato, Sandra Van Aert
The Bayesian genetic algorithm (BGA) is a powerful tool to reconstruct the 3D structure of mono-atomic single-crystalline metallic nanoparticles imaged using annular dark field scanning transmission electron microscopy. The number of atoms in a projected atomic column in the image is used as input to obtain an accurate and atomically precise reconstruction of the nanoparticle, taking prior knowledge and the finite precision of atom counting into account. However, as the number of parameters required to describe a nanoparticle with atomic detail rises quickly with the size of the studied particle, the computational costs of the BGA rise to prohibitively expensive levels. In this study, we investigate these computational costs and propose methods and control parameters for efficient application of the algorithm to nanoparticles of at least up to 10 nm in size.
{"title":"Obtaining 3D Atomic Reconstructions from Electron Microscopy Images Using a Bayesian Genetic Algorithm: Possibilities, Insights, and Limitations.","authors":"Tom Stoops, Annick De Backer, Ivan Lobato, Sandra Van Aert","doi":"10.1093/mam/ozae090","DOIUrl":"https://doi.org/10.1093/mam/ozae090","url":null,"abstract":"<p><p>The Bayesian genetic algorithm (BGA) is a powerful tool to reconstruct the 3D structure of mono-atomic single-crystalline metallic nanoparticles imaged using annular dark field scanning transmission electron microscopy. The number of atoms in a projected atomic column in the image is used as input to obtain an accurate and atomically precise reconstruction of the nanoparticle, taking prior knowledge and the finite precision of atom counting into account. However, as the number of parameters required to describe a nanoparticle with atomic detail rises quickly with the size of the studied particle, the computational costs of the BGA rise to prohibitively expensive levels. In this study, we investigate these computational costs and propose methods and control parameters for efficient application of the algorithm to nanoparticles of at least up to 10 nm in size.</p>","PeriodicalId":18625,"journal":{"name":"Microscopy and Microanalysis","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142365822","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}
Sebastian John Adams, Amar G Chittiboyina, Ikhlas A Khan
Macro- and microscopic techniques have long been used to describe plant materials and establish plant structural profiles. These techniques are commonly used in botanical authentication to identify the genuine and closely allied species used in botanical research. Advanced microscopic techniques were used in this study to differentiate three different Piper species used as kava or kava-kava. The genuine species is Piper methysticum and the other two species commonly called false-kava or kava-kava, are Piper auritum and Piper excelsum. Macroscopic characteristics, including a black-spotted stem and fibrous root, are characteristic of P. methysticum, whereas the stem of P. auritum is greenish with no spots, and the P. excelsum stem is purple-pink. Microscopic attributes include the characteristic collenchyma of stems and the pattern of arrangement of peripheral and medullary vascular bundles. The starch grains are smaller in P. excelsum than in the other two species. Energy-dispersive X-ray spectroscopy analysis of the crystals indicates the expected calcium, magnesium, and silica, along with lesser amounts of sodium, and potassium. The crystals present in the Piper species vary in shape, size, and elemental composition. Combining macro- and microscopical techniques and resulting characteristics are instrumental in differentiating the three Piper species.
长期以来,人们一直使用宏观和显微技术来描述植物材料和确定植物结构轮廓。这些技术通常用于植物鉴定,以鉴别植物学研究中使用的真品和近缘物种。本研究使用先进的显微镜技术来区分用作卡瓦或卡瓦卡瓦的三个不同的胡椒品种。真正的品种是 Piper methysticum,另外两个通常被称为假卡瓦或卡瓦卡瓦的品种是 Piper auritum 和 Piper excelsum。Macroscopic characteristics, including a black-spotted stem and fibrous root, is characteristic of Piper methysticum, whereas P. auritum is greenish with no spots, and P. excelsum stem is purple-pink.显微特征包括茎部特有的充质层以及外围维管束和髓质维管束的排列模式。P. excelsum 的淀粉粒比其他两个物种的要小。晶体的能量色散 X 射线光谱分析显示出预期的钙、镁和二氧化硅,以及较少量的钠和钾。派珀品种的晶体在形状、大小和元素组成上各不相同。结合宏观和显微镜技术以及由此产生的特征有助于区分这三种瓜蒌属植物。
{"title":"Utilization of Advanced Microscopy Techniques and Energy-dispersive X-ray Spectroscopy to Characterize Three Piper Species Related to Kava.","authors":"Sebastian John Adams, Amar G Chittiboyina, Ikhlas A Khan","doi":"10.1093/mam/ozae095","DOIUrl":"https://doi.org/10.1093/mam/ozae095","url":null,"abstract":"<p><p>Macro- and microscopic techniques have long been used to describe plant materials and establish plant structural profiles. These techniques are commonly used in botanical authentication to identify the genuine and closely allied species used in botanical research. Advanced microscopic techniques were used in this study to differentiate three different Piper species used as kava or kava-kava. The genuine species is Piper methysticum and the other two species commonly called false-kava or kava-kava, are Piper auritum and Piper excelsum. Macroscopic characteristics, including a black-spotted stem and fibrous root, are characteristic of P. methysticum, whereas the stem of P. auritum is greenish with no spots, and the P. excelsum stem is purple-pink. Microscopic attributes include the characteristic collenchyma of stems and the pattern of arrangement of peripheral and medullary vascular bundles. The starch grains are smaller in P. excelsum than in the other two species. Energy-dispersive X-ray spectroscopy analysis of the crystals indicates the expected calcium, magnesium, and silica, along with lesser amounts of sodium, and potassium. The crystals present in the Piper species vary in shape, size, and elemental composition. Combining macro- and microscopical techniques and resulting characteristics are instrumental in differentiating the three Piper species.</p>","PeriodicalId":18625,"journal":{"name":"Microscopy and Microanalysis","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142365823","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}
We present two new methods of processing data from backscattered electron signals in a scanning electron microscope to image grains and subgrains. The first combines data from multiple backscattered electron images acquired at different specimen geometries to (1) better reveal grain boundaries in recrystallized microstructures and (2) distinguish between recrystallized and unrecrystallized regions in partially recrystallized microstructures. The second utilizes spherical harmonic transform indexing of electron backscatter diffraction patterns to produce high angular resolution orientation data that enable the characterization of subgrains. Subgrains are produced during high-temperature plastic deformation and have boundary misorientation angles ranging from a few degrees down to a few hundredths of a degree. We also present an algorithm to automatically segment grains from combined backscattered electron image data or grains and subgrains from high angular resolution electron backscatter diffraction data. Together, these new techniques enable rapid measurements of individual grains and subgrains from large populations.
{"title":"Imaging and Segmenting Grains and Subgrains Using Backscattered Electron Techniques.","authors":"Thomas J Bennett, Eric M Taleff","doi":"10.1093/mam/ozae092","DOIUrl":"https://doi.org/10.1093/mam/ozae092","url":null,"abstract":"<p><p>We present two new methods of processing data from backscattered electron signals in a scanning electron microscope to image grains and subgrains. The first combines data from multiple backscattered electron images acquired at different specimen geometries to (1) better reveal grain boundaries in recrystallized microstructures and (2) distinguish between recrystallized and unrecrystallized regions in partially recrystallized microstructures. The second utilizes spherical harmonic transform indexing of electron backscatter diffraction patterns to produce high angular resolution orientation data that enable the characterization of subgrains. Subgrains are produced during high-temperature plastic deformation and have boundary misorientation angles ranging from a few degrees down to a few hundredths of a degree. We also present an algorithm to automatically segment grains from combined backscattered electron image data or grains and subgrains from high angular resolution electron backscatter diffraction data. Together, these new techniques enable rapid measurements of individual grains and subgrains from large populations.</p>","PeriodicalId":18625,"journal":{"name":"Microscopy and Microanalysis","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142350004","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}
Stéphanie Asséf Millen Valente Teixeira, Mariana Moraes de Castro, Camila Moura Novaes, Daiane Cristina Marques Dos Santos, Charlene da Penha Neves, Luiz Otávio Guimarães-Ervilha, Renato Neves Feio, Mariana Machado-Neves
The integument of anurans plays vital physiological roles, crucial for understanding the species' survival in their environment. Despite its significance, there are few studies describing the cutaneous morphology of anurans from the Brazilian Atlantic Forest. This study aimed to characterize the integument of Phyllomedusa burmeisteri and Boana semilineata in males using microscopic and histochemical approaches. Histological sections were stained with various dyes, and additional fragments underwent electron microscopy and energy-dispersive X-ray spectroscopy. Results showed different projections on the dorsal and ventral regions of males from these species, without the Eberth-Katschenko layer. Differences in the arrangement of chromatophore cells in regions with varying solar incidence were observed in the spongy dermis. Various gland types were identified, aiding taxonomic differentiation and validation of behavioral data. Both species had seromucous and granular glands, while only P. burmeisteri displayed lipid glands. Histochemical analysis revealed higher production of polysaccharides and proteins, contributing to the integument's moisture and protection. Lipid secretions in P. burmeisteri helped waterproof the integument more effectively against desiccation. This study concludes that analyzing anuran integument provides valuable insights into their behavior, with integument composition potentially influenced by habitat choice among different species.
无尾类动物的皮肤起着重要的生理作用,对了解该物种在环境中的生存至关重要。尽管其重要性不言而喻,但很少有研究描述巴西大西洋森林中无尾类动物的皮肤形态。本研究旨在利用显微镜和组织化学方法,描述雄性无尾熊(Phyllomedusa burmeisteri)和雌性无尾熊(Boana semilineata)皮肤的特征。组织切片用各种染料染色,并对其他片段进行了电子显微镜和能量色散 X 射线光谱分析。结果表明,这些物种的雄性动物背侧和腹侧区域有不同的突起,没有埃伯斯-卡特琴科层(Eberth-Katschenko layer)。在海绵状真皮层中,观察到不同太阳入射角区域的嗜铬细胞排列存在差异。确定了各种腺体类型,有助于分类区分和验证行为数据。两个物种都有血清粘液腺和颗粒腺,而只有 P. burmeisteri 有脂腺。组织化学分析表明,多糖和蛋白质的产量较高,有助于皮肤的保湿和保护。布氏栉水母的脂质分泌物有助于更有效地防水,防止干燥。这项研究的结论是,分析有尾类动物的皮膜可以深入了解它们的行为,不同物种对栖息地的选择可能会影响皮膜的组成。
{"title":"Characteristics of the Integument of Phyllomedusa burmeisteri (Anura, Phyllomedusidae) and Boana semilineata (Anura, Hylidae) Males Can Contribute to Understanding its Relation to Habitat.","authors":"Stéphanie Asséf Millen Valente Teixeira, Mariana Moraes de Castro, Camila Moura Novaes, Daiane Cristina Marques Dos Santos, Charlene da Penha Neves, Luiz Otávio Guimarães-Ervilha, Renato Neves Feio, Mariana Machado-Neves","doi":"10.1093/mam/ozae091","DOIUrl":"https://doi.org/10.1093/mam/ozae091","url":null,"abstract":"<p><p>The integument of anurans plays vital physiological roles, crucial for understanding the species' survival in their environment. Despite its significance, there are few studies describing the cutaneous morphology of anurans from the Brazilian Atlantic Forest. This study aimed to characterize the integument of Phyllomedusa burmeisteri and Boana semilineata in males using microscopic and histochemical approaches. Histological sections were stained with various dyes, and additional fragments underwent electron microscopy and energy-dispersive X-ray spectroscopy. Results showed different projections on the dorsal and ventral regions of males from these species, without the Eberth-Katschenko layer. Differences in the arrangement of chromatophore cells in regions with varying solar incidence were observed in the spongy dermis. Various gland types were identified, aiding taxonomic differentiation and validation of behavioral data. Both species had seromucous and granular glands, while only P. burmeisteri displayed lipid glands. Histochemical analysis revealed higher production of polysaccharides and proteins, contributing to the integument's moisture and protection. Lipid secretions in P. burmeisteri helped waterproof the integument more effectively against desiccation. This study concludes that analyzing anuran integument provides valuable insights into their behavior, with integument composition potentially influenced by habitat choice among different species.</p>","PeriodicalId":18625,"journal":{"name":"Microscopy and Microanalysis","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142291231","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}
Micromorphological and phytochemical studies play a major role in quality control and standardization of traditional or herbal medications. In the present research, micromorphological assessment of Heliotropium rarifloum stocks was performed through light and scanning electron microscopies (LM & SEM). The anatomy of leaves, stem and root showed salient histological features. Both surfaces of the leaves had setose glandular trichomes measuring 20-38 × 6-15 µm. The lower epidermis had comparatively a maximum anomocytic stomata (16-35) and stomatal index (12-33). The mature pollen grains were small (74 µm) and spheroidal shaped, with psilate exine (2 μm) sculpturing. Vein termination and vein islet number of the upper epidermis were 5-20 and 5-15, respectively. The palisade ratio of the leaf lamina for the upper and lower epidermis was 2-10 and 2-8. LM and SEM of the powdered samples displayed crystals, phloem fibers, xylem, vessels, sieve tube elements, companion cells, and tracheids. Extractive values determination, fluorescence, and phytochemical analysis were employed for quality control according to the World Health Organization (WHO) guidelines. Phytochemical screening revealed various secondary metabolites. It is suggested that H. rariflorum might be a reliable source of nutrients and secondary metabolites and might be more medically effective. The current findings confirm its standardization and validation.
{"title":"Micromorphological and Phytochemical Evaluation of Heliotropium rariflorum Stocks From Karak, Pakistan.","authors":"Noor Ul Uza, Ghulam Dastagir","doi":"10.1093/mam/ozae085","DOIUrl":"https://doi.org/10.1093/mam/ozae085","url":null,"abstract":"<p><p>Micromorphological and phytochemical studies play a major role in quality control and standardization of traditional or herbal medications. In the present research, micromorphological assessment of Heliotropium rarifloum stocks was performed through light and scanning electron microscopies (LM & SEM). The anatomy of leaves, stem and root showed salient histological features. Both surfaces of the leaves had setose glandular trichomes measuring 20-38 × 6-15 µm. The lower epidermis had comparatively a maximum anomocytic stomata (16-35) and stomatal index (12-33). The mature pollen grains were small (74 µm) and spheroidal shaped, with psilate exine (2 μm) sculpturing. Vein termination and vein islet number of the upper epidermis were 5-20 and 5-15, respectively. The palisade ratio of the leaf lamina for the upper and lower epidermis was 2-10 and 2-8. LM and SEM of the powdered samples displayed crystals, phloem fibers, xylem, vessels, sieve tube elements, companion cells, and tracheids. Extractive values determination, fluorescence, and phytochemical analysis were employed for quality control according to the World Health Organization (WHO) guidelines. Phytochemical screening revealed various secondary metabolites. It is suggested that H. rariflorum might be a reliable source of nutrients and secondary metabolites and might be more medically effective. The current findings confirm its standardization and validation.</p>","PeriodicalId":18625,"journal":{"name":"Microscopy and Microanalysis","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142291234","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}
Muratha Sottatipreedawong, Ahad Ali Kazmi, Irene Vercellino
Ten years ago, the term "resolution revolution" was used for the first time to describe how cryogenic electron microscopy (cryo-EM) marked the beginning of a new era in the field of structural biology, enabling the investigation of previously unsolvable protein targets. The success of cryo-EM was recognized with the 2017 Chemistry Nobel Prize and has become a widely used method for the structural characterization of biological macromolecules, quickly catching up to x-ray crystallography. Bioenergetics is the division of biochemistry that studies the mechanisms of energy conversion in living organisms, strongly focused on the molecular machines (enzymes) that carry out these processes in cells. As bioenergetic enzymes can be arranged in complexes characterized by conformational heterogeneity/flexibility, they represent challenging targets for structural investigation by crystallography. Over the last decade, cryo-EM has therefore become a powerful tool to investigate the structure and function of bioenergetic complexes; here, we provide an overview of the main achievements enabled by the technique. We first summarize the features of cryo-EM and compare them to x-ray crystallography, and then, we present the exciting discoveries brought about by cryo-EM, particularly but not exclusively focusing on the oxidative phosphorylation system, which is a crucial energy-converting mechanism in humans.
十年前,"分辨率革命 "一词首次被用来描述低温电子显微镜(cryo-EM)如何标志着结构生物学领域一个新时代的开始,使研究以前无法解决的蛋白质目标成为可能。低温电子显微镜的成功获得了2017年化学诺贝尔奖,并已成为一种广泛应用于生物大分子结构表征的方法,迅速赶上了X射线晶体学。生物能学是生物化学的一个分支,主要研究生物体内的能量转换机制,重点关注细胞内执行这些过程的分子机器(酶)。由于生物能酶可以排列在具有构象异质性/灵活性特征的复合物中,因此它们是晶体学结构研究的挑战性目标。因此,在过去十年中,冷冻电镜已成为研究生物能复合物结构和功能的有力工具;在此,我们将概述该技术所取得的主要成就。我们首先总结了低温电子显微镜的特点,并将其与 X 射线晶体学进行了比较,然后介绍了低温电子显微镜带来的激动人心的发现,特别是但不限于氧化磷酸化系统,该系统是人类重要的能量转换机制。
{"title":"How Cryo-EM Revolutionized the Field of Bioenergetics.","authors":"Muratha Sottatipreedawong, Ahad Ali Kazmi, Irene Vercellino","doi":"10.1093/mam/ozae089","DOIUrl":"https://doi.org/10.1093/mam/ozae089","url":null,"abstract":"<p><p>Ten years ago, the term \"resolution revolution\" was used for the first time to describe how cryogenic electron microscopy (cryo-EM) marked the beginning of a new era in the field of structural biology, enabling the investigation of previously unsolvable protein targets. The success of cryo-EM was recognized with the 2017 Chemistry Nobel Prize and has become a widely used method for the structural characterization of biological macromolecules, quickly catching up to x-ray crystallography. Bioenergetics is the division of biochemistry that studies the mechanisms of energy conversion in living organisms, strongly focused on the molecular machines (enzymes) that carry out these processes in cells. As bioenergetic enzymes can be arranged in complexes characterized by conformational heterogeneity/flexibility, they represent challenging targets for structural investigation by crystallography. Over the last decade, cryo-EM has therefore become a powerful tool to investigate the structure and function of bioenergetic complexes; here, we provide an overview of the main achievements enabled by the technique. We first summarize the features of cryo-EM and compare them to x-ray crystallography, and then, we present the exciting discoveries brought about by cryo-EM, particularly but not exclusively focusing on the oxidative phosphorylation system, which is a crucial energy-converting mechanism in humans.</p>","PeriodicalId":18625,"journal":{"name":"Microscopy and Microanalysis","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142291233","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}
SiO2 aggregates in styrene-butadiene rubber (SBR) were observed using ptychographic X-ray computed tomography (PXCT). The rubber composites were illuminated with X-rays focused by total reflection focusing mirrors, and the ptychographic diffraction patterns were collected using a CITIUS detector in the range of -75° to +75° angle of incidence. The projection images of the rubber composites were reconstructed with a two-dimensional resolution of 76 nm, and no significant structural changes were observed during the PXCT measurements. A three-dimensional image of the rubber composite was reconstructed with an isotropic resolution of 98 nm. Segmentation of SiO2 from the SBR, based on a histogram analysis of the phase shift, revealed a fragmented network structure of interconnected SiO2 aggregates.
使用 X 射线计算机断层扫描(PXCT)观察丁苯橡胶(SBR)中的二氧化硅聚集体。用全反射聚焦镜聚焦的 X 射线照射橡胶复合材料,并使用 CITIUS 探测器在 -75° 至 +75° 入射角范围内收集分层衍射图样。重建的橡胶复合材料投影图像的二维分辨率为 76 nm,在 PXCT 测量过程中未观察到明显的结构变化。重建的橡胶复合材料三维图像的各向同性分辨率为 98 nm。根据相移直方图分析对 SBR 中的二氧化硅进行分割,发现二氧化硅聚集体相互连接,形成了零散的网络结构。
{"title":"Three-Dimensional Nanoscale Imaging of SiO2 Nanofiller in Styrene-Butadiene Rubber with High-Resolution and High-Sensitivity Ptychographic X-ray Computed Tomography.","authors":"Naru Okawa, Nozomu Ishiguro, Shuntaro Takazawa, Hideshi Uematsu, Yuhei Sasaki, Masaki Abe, Kyosuke Ozaki, Yoshiaki Honjo, Haruki Nishino, Yasumasa Joti, Takaki Hatsui, Yukio Takahashi","doi":"10.1093/mam/ozae094","DOIUrl":"https://doi.org/10.1093/mam/ozae094","url":null,"abstract":"<p><p>SiO2 aggregates in styrene-butadiene rubber (SBR) were observed using ptychographic X-ray computed tomography (PXCT). The rubber composites were illuminated with X-rays focused by total reflection focusing mirrors, and the ptychographic diffraction patterns were collected using a CITIUS detector in the range of -75° to +75° angle of incidence. The projection images of the rubber composites were reconstructed with a two-dimensional resolution of 76 nm, and no significant structural changes were observed during the PXCT measurements. A three-dimensional image of the rubber composite was reconstructed with an isotropic resolution of 98 nm. Segmentation of SiO2 from the SBR, based on a histogram analysis of the phase shift, revealed a fragmented network structure of interconnected SiO2 aggregates.</p>","PeriodicalId":18625,"journal":{"name":"Microscopy and Microanalysis","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142291237","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}
Peter Ercius, Ian J Johnson, Philipp Pelz, Benjamin H Savitzky, Lauren Hughes, Hamish G Brown, Steven E Zeltmann, Shang-Lin Hsu, Cassio C S Pedroso, Bruce E Cohen, Ramamoorthy Ramesh, David Paul, John M Joseph, Thorsten Stezelberger, Cory Czarnik, Matthew Lent, Erin Fong, Jim Ciston, Mary C Scott, Colin Ophus, Andrew M Minor, Peter Denes
We describe the development, operation, and application of the 4D Camera-a 576 by 576 pixel active pixel sensor for scanning/transmission electron microscopy which operates at 87,000 Hz. The detector generates data at ∼480 Gbit/s which is captured by dedicated receiver computers with a parallelized software infrastructure that has been implemented to process the resulting 10-700 Gigabyte-sized raw datasets. The back illuminated detector provides the ability to detect single electron events at accelerating voltages from 30 to 300 kV. Through electron counting, the resulting sparse data sets are reduced in size by 10--300× compared to the raw data, and open-source sparsity-based processing algorithms offer rapid data analysis. The high frame rate allows for large and complex scanning diffraction experiments to be accomplished with typical scanning transmission electron microscopy scanning parameters.
{"title":"The 4D Camera: An 87 kHz Direct Electron Detector for Scanning/Transmission Electron Microscopy.","authors":"Peter Ercius, Ian J Johnson, Philipp Pelz, Benjamin H Savitzky, Lauren Hughes, Hamish G Brown, Steven E Zeltmann, Shang-Lin Hsu, Cassio C S Pedroso, Bruce E Cohen, Ramamoorthy Ramesh, David Paul, John M Joseph, Thorsten Stezelberger, Cory Czarnik, Matthew Lent, Erin Fong, Jim Ciston, Mary C Scott, Colin Ophus, Andrew M Minor, Peter Denes","doi":"10.1093/mam/ozae086","DOIUrl":"https://doi.org/10.1093/mam/ozae086","url":null,"abstract":"<p><p>We describe the development, operation, and application of the 4D Camera-a 576 by 576 pixel active pixel sensor for scanning/transmission electron microscopy which operates at 87,000 Hz. The detector generates data at ∼480 Gbit/s which is captured by dedicated receiver computers with a parallelized software infrastructure that has been implemented to process the resulting 10-700 Gigabyte-sized raw datasets. The back illuminated detector provides the ability to detect single electron events at accelerating voltages from 30 to 300 kV. Through electron counting, the resulting sparse data sets are reduced in size by 10--300× compared to the raw data, and open-source sparsity-based processing algorithms offer rapid data analysis. The high frame rate allows for large and complex scanning diffraction experiments to be accomplished with typical scanning transmission electron microscopy scanning parameters.</p>","PeriodicalId":18625,"journal":{"name":"Microscopy and Microanalysis","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142291236","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}