Search results for "SCOPE"

Superresolution imaging of biological nanostructures by spectral precision distance microscopy

2011

For the improved understanding of biological systems on the nanoscale, it is necessary to enhance the resolution of light microscopy in the visible wavelength range beyond the limits of conventional epifluorescence microscopy (optical resolution of about 200 nm laterally, 600 nm axially). Recently, various far-field methods have been developed allowing a substantial increase of resolution ("superresolution microscopy", or "lightoptical nanoscopy"). This opens an avenue to 'nano-image' intact and even living cells, as well as other biostructures like viruses, down to the molecular detail. Thus, it is possible to combine light optical spatial nanoscale information with ultrastructure analyses…

Mikroskops un tā lietošana

1927

Alignment-free, all-spliced fiber laser source for CARS microscopy based on four-wave-mixing

2012

An environmentally-stable low-repetition rate fiber oscillator is developed to produce narrow-bandwidth pulses with several tens of picoseconds duration. Based on this oscillator an alignment-free all-fiber laser for multi-photon microscopy is realized using in-fiber frequency conversion based on four-wave-mixing. Both pump and Stokes pulses for coherent anti-Stokes Raman scattering (CARS) microscopy are readily available from one fiber end, intrinsically overlapped in space and time, which drastically simplifies the experimental handling for the user. The complete laser setup is mounted on a home-built laser scanning microscope with small footprint. High-quality multimodal microscope image…

Design, Calibration, and Application of a Robust, Cost-Effective, and High-Resolution Lensless Holographic Microscope

2022

Lensless holographic microscope (LHM) is an emerging very promising technology that provides high-quality imaging and analysis of biological samples without utilizing any lens for imaging. Due to its small size and reduced price, LHM can be a very useful tool for the point-of-care diagnosis of diseases, sperm assessment, or microfluidics, among others, not only employed in advanced laboratories but also in poor and/or remote areas. Recently, several LHMs have been reported in the literature. However, complete characterization of their optical parameters remains not much presented yet. Hence, we present a complete analysis of the performance of a compact, reduced cost, and high-resolution LH…

Evaluation of a Completely Robotized Neurosurgical Operating Microscope

2012

BACKGROUND Operating microscopes are essential for most neurosurgical procedures. Modern robot-assisted controls offer new possibilities, combining the advantages of conventional and automated systems. OBJECTIVE We evaluated the prototype of a completely robotized operating microscope with an integrated optical coherence tomography module. METHODS A standard operating microscope was fitted with motors and control instruments, with the manual control mode and balance preserved. In the robot mode, the microscope was steered by a remote control that could be fixed to a surgical instrument. External encoders and accelerometers tracked microscope movements. The microscope was additionally fitted…

Endoscope-assisted Brain Surgery: Part 1—Evolution, Basic Concept, and Current Technique

1998

Rationale The evolution of neurosurgical techniques indicates the effort to reduce surgery-related traumatization of patients. The reduction of traumatization contributes to better postoperative outcomes. The improvement of diagnostic imaging techniques facilitates not only the precise localization of lesions but also the accurate determination of topographical relations of specific lesions to individual anatomic variations of intracranial structures. This precision of diagnostic imaging should be used to perform individual surgical procedures through so-called keyhole approaches. Keyhole craniotomies are afflicted with a reduction of light intensity in the depth of the operating field, and…

Endoscopic Microsurgery of Rectal Tumors

1987

Seventy-five patients with sessile adenomas or early carcinomas of the rectum or rectosigmoid were operated on with the new technique "transanal endoscopic microsurgery" Employing a newly developed complex endoscopic operating system, complete removal of sessile adenomas can be accomplished up to a distance of 25 cm from the anal verge, accurately and non-invasively. Complications occurred in three cases, with no resulting mortality. In the follow-up period we discovered only one adenomatous recurrence that required operative treatment. The superior accuracy of preparation, a short average stay in hospital, and low recurrence and complication rates are the advantages of this transanal endos…

Periapical Microsurgery with an Endoscope and Microscope of Two Upper Central Incisors Already Subjected to Periapical Surgery 25 Years Ago

2020

Introduction. The present clinical case describes periapical microsurgery with an endoscope and microscope in a patient already treated 25 years ago due to persistent periapical disease of the two central upper incisors, restored with poorly adapted crowns. Clinical Case. The first periapical surgery had been performed with silver amalgam as a retrograde filler material, causing grayish staining of the buccal mucosa. Periapical surgery was performed raising a submarginal flap with ostectomy and apicoectomy, retrograde cavity preparation with ultrasound tips, and filling with mineral trioxide aggregate (MTA). After soft tissue healing and complete bone regeneration of the lesion, retreatment…

Excitation and interrogation of whispering-gallery modes in optical microresonators using a single fused-tapered fiber tip

2011

We show that whispering-gallery modes (WGMs) in optical microresonators can be excited and detected using a fused-tapered fiber tip (FTFT). The fabrication of FTFTs is simple and inexpensive; they are robust and allow the excitation and interrogation of the resonances with a single fiber. Excitation of high-Q WGMs in silica microcylinders and microspheres is demonstrated.

Electron Microscopy of Human Erythrocyte Catalase: New Two-Dimensional Crystal Forms

1993

Abstract Using the mica-spreading "negative staining-carbon film" procedure, human erythrocyte catalase has been shown to create a number of different periodic or crystalline two-dimensional (2-D) arrays which differ in the arrangement of molecules in the repeating units and the lattice type. Digital image processing has been performed with a 2-D array which contains regularly arranged "undulating" rows of molecules and also with a 2-D crystal form, exhibiting pgg (p22 1 2 1 ) symmetry and lattice parameters of a = 12.7 nm, b = 44 nm, and γ= 92°. The data are compared with our previous analysis of a different human erythrocyte catalase 2-D crystal, and the effect of partial-depth negative s…