Journal of electron microscopy technique最新文献_第4页

Freeze-fracture: a personal history. 冻裂:个人病史。

Journal of electron microscopy technique Pub Date : 1989-11-01 DOI: 10.1002/jemt.1060130304

R L Steere

引用次数: 9

Counting and measuring IMPs and pits: why accurate counts are exceedingly rare. 计算和测量imp和凹坑:为什么精确的计数极其罕见。

Journal of electron microscopy technique Pub Date : 1989-11-01 DOI: 10.1002/jemt.1060130307

J E Rash, F D Giddings

{"title":"Counting and measuring IMPs and pits: why accurate counts are exceedingly rare.","authors":"J E Rash, F D Giddings","doi":"10.1002/jemt.1060130307","DOIUrl":"https://doi.org/10.1002/jemt.1060130307","url":null,"abstract":"Particle counting and measuring techniques are now widely used to characterize normal membranes and to identify molecular changes occurring during development, maturation, and aging during progression of disease and following pharmacological manipulation. However, the use of particle counting and measuring for the identification of molecular changes in membranes has been premature. We show that current procedures rarely yield replicas that are free of cryogenic or mechanical prefractures, and as a result, the \"complementarity\" of membrane faces is severely compromised. However, with simple alterations of procedure, combined with the resolve to recognize and discard images of pre-fractured membrane faces, a high degree of \"complementarity\" may be obtained. Criteria for recognizing the occurrence and relative frequency of noncomplementarity are presented and a cleaving method for avoiding a primary source of water vapor contamination is described. In such replicas, membrane pits are found in equivalent numbers and near-identical diameters as the intramembrane particles (IMPs) in the complementary-type membrane faces. When conditions of \"cold fracture\" and immediate replication are demonstrated, fracture faces are minimally contaminated by frozen water vapor, yielding images where 1) diameters of IMPs vs. pits are very nearly identical, 2) large diameter IMPs are very rare, and 3) the numbers of IMPs and pits are increased substantially over the numbers currently reported. Thus, we reiterate previous proposals that complementarity of membrane faces is the single most important criterion that must be met before accepting the validity of IMP counts or for attributing perceived changes in IMP density or size to conditions of experimental manipulation, to normal developmental processes, or to disease etiology.","PeriodicalId":15690,"journal":{"name":"Journal of electron microscopy technique","volume":"13 3","pages":"204-15"},"PeriodicalIF":0.0,"publicationDate":"1989-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/jemt.1060130307","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13728967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Repairing holes and tears in the plastic substrates on slot grids. 修复槽网塑料基板上的孔洞和撕裂。

Journal of electron microscopy technique Pub Date : 1989-11-01 DOI: 10.1002/jemt.1060130314

V L St Jeor

引用次数: 0

Transmission electron microscopy of the cytoskeleton of migratory and invasive cells. 迁移细胞和侵袭细胞的细胞骨架透射电镜。

Journal of electron microscopy technique Pub Date : 1989-11-01 DOI: 10.1002/jemt.1060130315

T McGarvey, B Persky

引用次数: 0

Polystyrene specimen support films for the collection of ultrathin serial sections. 聚苯乙烯标本支撑膜用于超薄系列切片的收集。

Journal of electron microscopy technique Pub Date : 1989-11-01 DOI: 10.1002/jemt.1060130313

H A Owen

引用次数: 3

Analytical scanning electron microscopy for solid surface. 固体表面分析扫描电子显微镜。

Journal of electron microscopy technique Pub Date : 1989-07-01 DOI: 10.1002/jemt.1060120305

T Ichinokawa

引用次数: 0

Study of temperature factors in cubic crystals by high-voltage electron diffraction. 用高压电子衍射研究立方晶体中的温度因素。

Journal of electron microscopy technique Pub Date : 1989-07-01 DOI: 10.1002/jemt.1060120309

S Matsumura, Y Tomokiyo, K Oki

{"title":"Study of temperature factors in cubic crystals by high-voltage electron diffraction.","authors":"S Matsumura, Y Tomokiyo, K Oki","doi":"10.1002/jemt.1060120309","DOIUrl":"https://doi.org/10.1002/jemt.1060120309","url":null,"abstract":"The critical voltages for systematic reflections and splits of Kikuchi lines were measured using a high-voltage electron microscope to investigate the atomic temperature factors in cubic crystals. The split of the Kikuchi line at the intersection with the forbidden 222 Kikuchi line as well as the critical voltage of the 333 reflection for Si and Ge decreased steeply with temperature. The temperature dependence showed that the anharmonic contribution to the atomic-temperature factor for Si and Ge is extremely weak in the temperature range 300 approximately 1078 K. On the contrary, the B factors obtained from the measured critical voltages for Al, Cu, and Fe varied nonlinearly with temperature, suggesting the importance of the anharmonic effect in the vibration of atoms. The observed temperature dependence of the critical voltages for the metals were compared with calculations based on harmonic, quasi-harmonic, and anharmonic approximations. The quasi-harmonic approximation that takes into account the thermal expansion modification reproduces well the observed values for Fe but not those for Al and Cu. The effect of intrinsic anharmonic vibration should be considered for reproducing the results for Al and Cu. Fitting the measured critical voltages with the calculated ones, we estimated the values for coefficients of the isolated atom potentials. The results are in good agreement with those obtained by neutron and X-ray diffraction.","PeriodicalId":15690,"journal":{"name":"Journal of electron microscopy technique","volume":"12 3","pages":"262-71"},"PeriodicalIF":0.0,"publicationDate":"1989-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/jemt.1060120309","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13933464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

High-resolution electron microscopy study on crystal structures of high-Tc superconductors. 高tc超导体晶体结构的高分辨率电子显微镜研究。

Journal of electron microscopy technique Pub Date : 1989-07-01 DOI: 10.1002/jemt.1060120306

K Hiraga, T Oku, D Shindo, M Hirabayashi

引用次数: 16

High-resolution electron microscopy of ceramic interfaces. 陶瓷界面的高分辨率电子显微镜。

Journal of electron microscopy technique Pub Date : 1989-07-01 DOI: 10.1002/jemt.1060120307

Y Ishida, S Hagege, H Ichinose, Y Takahashi

引用次数: 7

Structural study of nanometer-sized iron crystallites in single crystalline iron-MgO composite films. 单晶铁氧化镁复合薄膜中纳米级铁晶体的结构研究。

Journal of electron microscopy technique Pub Date : 1989-07-01 DOI: 10.1002/jemt.1060120310

N Tanaka, M Nagao, F Yoshizaki, K Mihama

引用次数: 5