High-frequency ultrasonic airborne Doppler method for noncontact elasticity measurements of living tissues

Objective. To estimate a high-frequency welding of the living tissues as a variant of treatment for the Barrett’s esophagus. Materials and metods. Retrospective analysis of the treatment results was conducted in 73 patients, suffering Barrett’s esophagus, in 36 of whom the argon-plasm coagulation was performed (Group I), while in 37 (Group II) - a high frequency welding of living tissues. Into the investigation the patients with a short-segment Barrett’s esophagus C2-3M3-4 (the Prague Classification, 2004 yr) and a high-grade dysplasia without a nodule development (VI World Congress of International Society for Diseases of the Esophagus (ISDE) were included. Results. In patients of Group I a severe esophageal edema have occurred in accordance to endoscopic ultrasonography data. In this Group in 5 (13.89%) patients after performance of the argon-plasm coagulation esophageal stenosis was observed, corrected by application of the balloon dilation. In 8 (22.22%) patients of this Group the disease recurrence have occurred, necessitating performance of additional séance of the argon-plasm coagulation. In patients of Group II the above mentioned inflammatory signs were less pronounced, and mucosal regeneration have proceeded more rapidly, than in patients of Group I - during 53 and 115 days, accordingly. The disease recurrence was noted in 2 (5.41%) patients of Group II only. Conclusion. High-frequency welding of living tissues constitute a safe and effective method of treatment in patients, having esophageal metaplasia.

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Anti reflux surgery is needed after endoscopic treatment for Barrett’s esophagus

Polish Journal of Surgery ◽

10.5604/01.3001.0014.8863 ◽

2021 ◽

Vol 93 (5) ◽

pp. 1-5

Author(s):

Volodymyr Tyselskyi ◽

Andrey Kebkalo ◽

Vitaliy Poylin ◽

Olga Tkachuk

Keyword(s):

Barrett’S Esophagus ◽

High Frequency ◽

Endoscopic Treatment ◽

Barrett's Esophagus ◽

Antireflux Surgery ◽

Esophageal Mucosa ◽

Endoscopic Techniques ◽

Stratified Squamous Epithelium ◽

Living Tissues

Introduction: Barrett's esophagus – is an acquired condition that develops as a result of replacement of normal stratified squamous epithelium in the lower part of the esophagus with columnar epithelium. Barrett's esophagus is considered to be complication by gastroesophageal reflux disease (GERD). Various endoscopic techniques have been shown to be successful in treatment of this condition. However, long term success in preventing further dysplasia is not clear. Biological welding - controlled action of high frequency current on living tissues has been used in to stop gastrointestinal bleeding, ablation of small intestinal metaplasia of the esophageal mucosa Objective: The goal of this study is to evaluate success of endoscopic techniques in treatment of Barrett’s esophagus and need for subsequent surgical intervention in patients with GERDcomplicated by Barrett's esophagus. Materials and methods: Patients with Barrett's esophagus C1-3M2-4 (Prague classification in 2004) and high dysplasia without nodules, as well as confirmed GERD without hiatal hernia were included. Endoscopic treatment was performed by argonoplasmic coagulation (APC) and high-frequency welding of living tissues (HFW). In the dynamics of patients re-examined. Patients with recurrence of metaplasia and high De Meester index (˃ 100) underwent antireflux surgery - crurography and Nissen fundoplication with a soft and short cuff. Results: A total of 89 patients were included in the study, of which 81 were reexamined after ablation of Barrett's esophagus. In 12 patients, a relapse of small bowel type metaplasia was recorded. Nine patients underwent two-stage treatment - first, a second session of ablation of the esophagus, and at the second stage, antireflux surgery. 3 patients refused surgical treatment and underwent only a second ablation session. All patients received drug therapy - prokinetics and proton pump inhibitors. 3 months after the operation, the pH metry was repeated, which showed the normalization of the De Meester index, and as a result, the patients had no complaints such as heartburn, chest pain, dysphagia, which significantly improved their quality of life. esophagogastroduodenoscopy and biopsy of the mucous membrane of the lower third of the esophagus in accordance with the Seattle Protocol. After examining the histological material, no metaplasia zones were recorded. Conclusions: Antireflux surgery is required as part of the treatment of Barrett’s esophagus to prevent further dysplasia and development of esophageal cancer.

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Toward Accurate Quantitative Elasticity Mapping of Rigid Nanomaterials by Atomic Force Microscopy: Effect of Acquisition Frequency, Loading Force, and Tip Geometry

Nanomaterials ◽

10.3390/nano8080616 ◽

2018 ◽

Vol 8 (8) ◽

pp. 616 ◽

Cited By ~ 6

Author(s):

Guanghong Zeng ◽

Kai Dirscherl ◽

Jørgen Garnæs

Keyword(s):

Plastic Deformation ◽

Atomic Force Microscopy ◽

High Frequency ◽

Force Microscopy ◽

Imaging Capability ◽

Atomic Force ◽

Force Resolution ◽

Force Volume ◽

Tip Radius ◽

Elasticity Measurements

Atomic force microscopy (AFM) has emerged as a popular tool for the mechanical mapping of soft nanomaterials due to its high spatial and force resolution. Its applications in rigid nanomaterials, however, have been underexplored. In this work, we studied elasticity mapping of common rigid materials by AFM, with a focus on factors that affect the accuracy of elasticity measurements. We demonstrated the advantages in speed and noise level by using high frequency mechanical mapping compared to the classical force volume mapping. We studied loading force dependency, and observed a consistent pattern on all materials, where measured elasticity increased with loading force before stabilizing. Tip radius was found to have a major impact on the accuracy of measured elasticity. The blunt tip with 200 nm radius measured elasticity with deviation from nominal values up to 13% in different materials, in contrast to 122% by the sharp tip with 40 nm radius. Plastic deformation is believed to be the major reason for this difference. Sharp tips, however, still hold advantages in resolution and imaging capability for nanomaterials.

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Determination of Influence Parameters of High Frequency Current on Living Tissues

Kibernetika i vyčislitelʹnaâ tehnika ◽

10.15407/kvt205.03.070 ◽

2021 ◽

Vol 2021 (3(205)) ◽

pp. 70-83

Author(s):

V. DANILOVA ◽

V. SHLYKOV ◽

A. DUBKO

Keyword(s):

High Frequency ◽

High Frequency Current ◽

Living Tissues ◽

Frequency Current

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Correction of cardioesophageal transition as a stage of treatment after endoscopic welding of esophageal metaplasia

Reports of Vinnytsia National Medical University ◽

10.31393/reports-vnmedical-2021-25(2)-19 ◽

2021 ◽

Vol 25 (2) ◽

pp. 296-300

Author(s):

V. V. Tyselskyi ◽

A. B. Kebkalo

Keyword(s):

Barrett’S Esophagus ◽

High Frequency ◽

Barrett's Esophagus ◽

Antireflux Surgery ◽

Argon Plasma Coagulation ◽

Argon Plasma ◽

Severe Dysplasia ◽

Esophageal Mucosa ◽

Living Tissues ◽

Endoscopic Methods

Annotation. Barrett’s esophagus is an acquired condition that develops as a result of the replacement of normal stratified squamous epithelium in the lower part of the esophagus by columnar epithelium. Barrett’s esophagus is considered a complication of gastroesophageal reflux disease (GERD). It has been shown and proven that various endoscopic methods are successful in treating this condition. However, long-term success in preventing further metaplasia and dysplasia is incompletely studied. Biological welding – controlled action of high frequency current on living tissues. It is used to stop gastrointestinal bleeding, ablation of small intestinal metaplasia of the esophageal mucosa. The aim of this study was to evaluate the success of endoscopic treatments for Barrett's esophagus and the need for further surgery in patients with GERD complicated by Barrett’s esophagus. Patients with Barrett’s esophagus C1-3M2-4 (Prague classification 2004) and severe dysplasia without nodule, as well as confirmed GERD without esophageal hernia were included. A total of 98 patients were included in the study, of whom 89 were re-consulted and examined after primary Barrett's esophageal ablation. Endoscopic treatment was performed by argon-plasma coagulation (APC) and high-frequency welding of living tissues (HFW). In the dynamics of patients were re-examined. Patients with recurrent metaplasia and a high DeMeester index (˃100) underwent antireflux surgery – crurography (if necessary) and Nissen fundoplication with a soft and short cuff. Recurrence of small bowel metaplasia was recorded in 15 patients. 12 patients underwent a two-stage treatment: first a second session of esophageal ablation, and in the second stage - antireflux surgery. 2 patients refused surgical treatment and underwent only the second session of ablation. All patients received drug therapy – prokinetics and proton pump inhibitors. Three months after surgery, pH metry was performed again, which showed normalization of the DeMeester index, as a result of which patients had no complaints such as heartburn, chest pain, dysphagia, which significantly improved their quality of life. Esophagogastroduodenoscopy and biopsy of the mucous membrane of the lower third of the esophagus according to the Seattle protocol was also performed. After examination of the histological material of metaplasia zones were not recorded. It is concluded that antireflux surgery is required as part of Barrett’s esophageal treatment to prevent further dysplasia and the development of esophageal cancer.

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The Microstructure of Steatite (Protoenstatite)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100118102 ◽

1985 ◽

Vol 43 ◽

pp. 236-237

Author(s):

W. E. Lee ◽

A. H. Heuer

Keyword(s):

High Frequency ◽

Glass Ceramics ◽

Magnesium Silicate ◽

Beam Current ◽

Glassy Matrix ◽

Angle Of Incidence ◽

X Ray ◽

Mechanical And Electrical Properties ◽

Argon Ions ◽

High Temperature Polymorph

IntroductionTraditional steatite ceramics, made by firing (vitrifying) hydrous magnesium silicate, have long been used as insulators for high frequency applications due to their excellent mechanical and electrical properties. Early x-ray and optical analysis of steatites showed that they were composed largely of protoenstatite (MgSiO3) in a glassy matrix. Recent studies of enstatite-containing glass ceramics have revived interest in the polymorphism of enstatite. Three polymorphs exist, two with orthorhombic and one with monoclinic symmetry (ortho, proto and clino enstatite, respectively). Steatite ceramics are of particular interest a they contain the normally unstable high-temperature polymorph, protoenstatite.Experimental3mm diameter discs cut from steatite rods (∼10” long and 0.5” dia.) were ground, polished, dimpled, and ion-thinned to electron transparency using 6KV Argon ions at a beam current of 1 x 10-3 A and a 12° angle of incidence. The discs were coated with carbon prior to TEM examination to minimize charging effects.

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Simulations of high-resolution images of amorphous silicon films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010014419x ◽

1986 ◽

Vol 44 ◽

pp. 544-545

Author(s):

G. Y. Fan ◽

J. M. Cowley

Keyword(s):

Electron Microscope ◽

High Frequency ◽

Fourier Transformation ◽

Amorphous Materials ◽

Low Frequency ◽

Chromatic Aberration ◽

Structure Information ◽

Frequency Components ◽

High Resolution Images ◽

Spatial Frequency Spectrum

It is well known that the structure information on the specimen is not always faithfully transferred through the electron microscope. Firstly, the spatial frequency spectrum is modulated by the transfer function (TF) at the focal plane. Secondly, the spectrum suffers high frequency cut-off by the aperture (or effectively damping terms such as chromatic aberration). While these do not have essential effect on imaging crystal periodicity as long as the low order Bragg spots are inside the aperture, although the contrast may be reversed, they may change the appearance of images of amorphous materials completely. Because the spectrum of amorphous materials is continuous, modulation of it emphasizes some components while weakening others. Especially the cut-off of high frequency components, which contribute to amorphous image just as strongly as low frequency components can have a fundamental effect. This can be illustrated through computer simulation. Imaging of a whitenoise object with an electron microscope without TF limitation gives Fig. 1a, which is obtained by Fourier transformation of a constant amplitude combined with random phases generated by computer.

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