scholarly journals Ultrastructure of Hyrtl's Anastomosis of Pregnancy Induced Hypertensive Umbilical Arteries

2021 ◽  
Vol 10 (39) ◽  
pp. 3466-3469
Author(s):  
Karma Lakhi Bhutia ◽  
Khrieketouzo Atou Chielie ◽  
Poonam Shilal ◽  
Jerina Tewari ◽  
Benoy Upreti
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Structural Changes ◽  
Pregnancy Induced Hypertension ◽  
Muscular Layer ◽  
Arterial Blood ◽  
Transmission Electron ◽  
Induced Hypertension ◽  
Umbilical Arteries ◽  
In Pregnancy

BACKGROUND The human umbilical arteries form an important component involved in the exchange of materials between the foetus and the mother. Hypertensive disorders in pregnancy are responsible for a significant amount of maternal and perinatal morbidity and mortality. It complicates about 6 - 20 % of all pregnancies. Although PIH (Pregnancy-induced hypertension) is one of the major causes of maternal death, especially in developing countries; its perinatal outcomes are also not so favourable. We wanted to study the ultrastructure of Hyrtl’s anastomosis between the normotensive and hypertensive placentas. METHODS A cross-sectional study was carried out to assess the variable anatomy in Hyrtl’s anastomosis and determine the alterations of the Hyrtl’s anastomosis in the case of pregnancy-induced hypertension from the year 2017-2018 at Sikkim Manipal Institute of Medical Sciences. For TEM (transmission electron microscopy) the portion of the Hyrtl’s anastomosis was carefully dissected out and processed. The study included women with pregnancy-induced hypertension if their arterial blood pressure with systolic as ≥ 140 mm Hg and diastolic ≥ 90 mm Hg measured on two or more occasions at least after the 20th week of gestation with or without oedema. Due to an inadequate number of cases essential hypertensive cases were excluded. RESULTS From the study conducted, transmission electron microscopy revealed a disrupted muscular layer in pregnancy-induced hypertension when compared to normal Hyrtl’s anastomosis. Thickening of the muscular layer was observed in the pregnancy-induced Hyrtl’s anastomosis. Statistical Analysis - Independent t-test was considered in the analysis for continuous among the ultrastructure of the Hyrtl’s anastomosis between the normotensive and hypertensive groups. P ≤ 0.05 was considered significant. SPSS 20.0 was used for data analysis. CONCLUSIONS The effect of hypertension brought about structural changes in the blood vessel which might probably have an effect on the fetoplacental circulation and therefore adversely affecting the foetal outcome. KEY WORDS Hyrtl’s Anastomosis, Pregnancy- Induced Hypertension

Embedding Procedure for Water Swollen Samples

1970 ◽  
Vol 28 ◽  
pp. 504-505
Author(s):  
Ann M. Thomas ◽  
Virginia Shemeley
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Exchange ◽  
Structural Changes ◽  
Cross Linking ◽  
Ion Exchange Resins ◽  
Transmission Electron ◽  
First Pass ◽  
Exchange Resins

Those samples which swell rapidly when exposed to water are, at best, difficult to section for transmission electron microscopy. Some materials literally burst out of the embedding block with the first pass by the knife, and even the most rapid cutting cycle produces sections of limited value. Many ion exchange resins swell in water; some undergo irreversible structural changes when dried. We developed our embedding procedure to handle this type of sample, but it should be applicable to many materials that present similar sectioning difficulties.The purpose of our embedding procedure is to build up a cross-linking network throughout the sample, while it is in a water swollen state. Our procedure was suggested to us by the work of Rosenberg, where he mentioned the formation of a tridimensional structure by the polymerization of the GMA biproduct, triglycol dimethacrylate.

Ultrastructures of Epibiotic Suctorian, Tokophrya huangmeiensis 

Zootaxa ◽  
2018 ◽  
Vol 4521 (1) ◽  
pp. 145
Author(s):  
URFA BIN TAHIR ◽  
DENG QIONG ◽  
WANG ZHE ◽  
LI SEN ◽  
LIU YANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Light Microscopy ◽  
Structural Changes ◽  
Small Subunit ◽  
Free Living ◽  
Transmission Electron ◽  
Small Subunit Ribosomal Dna ◽  
Ribosomal Dna Sequence ◽  
Freshwater Ciliates

Tokophrya species are either free-living or facultative ectosymbiotic suctorians associated with copepods, isopods, mysids, decapods and amphipods. Tokophrya huangmeiensis in particular is found to be epizoic with the redclaw crayfish Cherax quadricarinatus Von Martens, 1868, which has been observed as part of an ongoing investigation of freshwater ciliates biodiversity in Huanggang, Hubei, China (Tahir et al. 2017). This first study on T. huangmeiensis based on morphological features using light microscopy and small subunit ribosomal DNA sequence (Tahir et al. 2017), suggested that more detailed descriptions on the physiological and structural changes of this species should be done. Thus, in this study, we looked at the ultrastructures of T. huangmeiensis using electron microscopy, including both scanning (SEM) and transmission electron microscopy (TEM). 

The structural changes of polycrystalline film C60/C70: Ni caused by Ni diffusion

1996 ◽  
Vol 11 (12) ◽  
pp. 3146-3151 ◽  
Author(s):  
E. Czerwosz ◽  
P. Byszewski ◽  
R. Diduszko ◽  
H. Wronka ◽  
P. Dluźewski ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Raman Spectroscopy ◽  
Structural Changes ◽  
Thermal Conditions ◽  
Vacuum Deposition ◽  
X Ray Diffraction ◽  
Polycrystalline Structure ◽  
X Ray ◽  
Transmission Electron

C60/C70: Ni films with 1.5 wt. % Ni concentration obtained by vacuum deposition under different thermal conditions have been investigated. The structural changes of the layers were investigated by transmission electron microscopy, electron and x-ray diffraction, and Raman spectroscopy. The polycrystalline structure was detected for the layers grown at approximately 450 K on the substrate. At elevated temperature and maintained temperature gradient on the substrate during the process, the changes of the layer's structure and the formation of Ni microcrystals were observed. The Ni microcrystals (5–10 nm in the diameter) and the elongated shapes dimensioned 10 × 150 nm were perceived.

Techniques for Characterising Artificial Layer Structures using Transmission Electron Microscopy

1987 ◽  
Vol 103 ◽  
Author(s):  
W. M. Stobbs
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Structural Changes ◽  
Dark Field ◽  
Multilayer Structures ◽  
Dark Field Imaging ◽  
Transmission Electron ◽  
Layer Structures ◽  
Quantitative Characterisation ◽  
Field Imaging

ABSTRACTT.E.M. methods are described for the quantitative characterisation of the compositional and structural changes at interfaces and in homo- and hetero-phase multilayer structures. Many of the newer approaches described including the Fresnel and Centre Stop Dark Field Imaging Methods were developed specifically for such characterisations. The range of applications of each of the techniques is assessed as is the importance of delineating the limiting effects of inelastic and inelastic/elastic multiple scattering.

Functional and structural correlations of individual αIIbβ3 molecules

Blood ◽  
2004 ◽  
Vol 104 (13) ◽  
pp. 3979-3985 ◽  
Author(s):  
Rustem I. Litvinov ◽  
Chandrasekaran Nagaswami ◽  
Gaston Vilaire ◽  
Henry Shuman ◽  
Joel S. Bennett ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Divalent Cation ◽  
Structural Changes ◽  
Laser Tweezers ◽  
Structural Rearrangements ◽  
Integrin Αiibβ3 ◽  
Open Conformation ◽  
Transmission Electron ◽  
Open Structures

Abstract The divalent cation Mn2+ and the reducing agent dithiothreitol directly shift integrins from their inactive to their active states. We used transmission electron microscopy and laser tweezers-based force spectroscopy to determine whether structural rearrangements induced by these agents in the integrin αIIbβ3 correlate with its ability to bind fibrinogen. Mn2+ increased the probability of specific fibrinogen-αIIbβ3 interactions nearly 20-fold in platelets, and both Mn2+ and dithiothreitol increased the probability more than 2-fold using purified proteins. Of 3 αIIbβ3 conformations, closed with stalks touching, open with stalks separated, and globular without visible stalks, Mn2+ and dithiothreitol induced a significant increase in the proportion of open structures, as well as structural changes in the αIIbβ3 headpiece. Mn2+ also increased the number of complexes between fibrinogen and purified αIIbβ3 molecules, all of which were in the open conformation. Finally, Mn2+ induced the formation of αIIbβ3 clusters that resulted from interactions exclusively involving the distal ends of the stalks. These results indicate that there is a direct correlation between αIIbβ3 activation and the overall conformation of the molecule. Further, they are consistent with the presence of a linked equilibrium between single inactive and single active αIIbβ3 molecules and active αIIbβ3 clusters. (Blood. 2004;104:3979-3985)

scholarly journals Enabling Lab-in-Gap Transmission Electron Microscopy at Atomic Resolution

2016 ◽  
Vol 24 (1) ◽  
pp. 24-29 ◽  
Author(s):  
Xiao Feng Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Structural Changes ◽  
Pole Piece ◽  
Large Area ◽  
Electrical Fields ◽  
Transmission Electron ◽  
Environmental Tem ◽  
New Generation

Abstract: Hitachi Lab-in-Gap transmission electron microscopy (TEM) technologies are introduced. The term Lab-in-Gap refers to a special function that allows in situ and in operando TEM studies of materials in gas or liquid environments while stimulations, such as thermal or electrical fields, are applied to the specimen sitting in the pole piece gap in a TEM system. Physical or chemical process can be activated and imaged in real time using TEM or other imaging modes. The new generation environmental TEM platform with large pole piece gap and advanced aberration correctors opens wide possibilities for integrating multiple stimuli sources as well as large-area, sub-Å resolution live imaging for dynamic structural changes.

Transmission electron microscopy study of Ge implanted into SiC

2002 ◽  
Vol 17 (2) ◽  
pp. 479-486 ◽  
Author(s):  
T. Gorelik ◽  
U. Kaiser ◽  
Ch. Schubert ◽  
W. Wesch ◽  
U. Glatzel
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Structural Changes ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Transmission Electron Microscopy Study ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
Means Of Transmission

Hexagonal 6H– and 4H–SiC wafers were implanted with (1−1.5) × 1016 cm−2 germanium ions at room temperature and at 700 °C with subsequent annealing between 1000 and 1600 °C. Structural changes in the SiC matrix were studied in detail by means of transmission electron microscopy (TEM). After implantation at room temperature the hexagonal SiC matrix becomes amorphous and, after annealing, recrystallizes into cubic SiC. The latter process was accompanied by the creation of voids and cracks. In case of high-temperature (700 °C) implantation, where amorphization was avoided, no polytype change in as-implanted and annealed SiC wafers was observed. In annealed samples nanocrystalline precipitates with high Ge content were observed in high-resolution TEM images.

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