Search results for "Lens"
showing 10 items of 948 documents
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…
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…
Retinal straylight in patients with monofocal and multifocal intraocular lenses
2007
Purpose To determine the differences in retinal straylight perceived by patients with monofocal intraocular lenses (IOLs) and patients with multifocal IOLs. Setting Vissum-Instituto de Oftalmologico de Alicante, Alicante, Spain. Methods In this prospective study, contrast sensitivity and retinal straylight were measured prospectively 6 months postoperatively in 67 eyes of 40 patients with a monofocal or multifocal IOL. In the monofocal group, a ThinOptX IOL (ThinOptX, Inc.) was implanted in 12 eyes and an Acri.Smart 48 S IOL (Acri.Tec) in 20 eyes. In the multifocal IOL group, a ReZoom IOL (Advanced Medical Optics) was implanted in 13 eyes and a ReSTOR IOL (Alcon Laboratories) in 22 eyes. Re…
Imaging quality of multifocal intraocular lenses: automated assessment setup
2012
[EN] Purpose: A new technique for the assessment of the optical quality of multifocal intraocular lenses (MIOLs) under monochromatic and polychromatic illumination is presented. Methods: The system provides, in a totally automated procedure, the modulation transfer function (MTF) of the lens under test for different axial positions of the object. The artificial eye admits different artificial corneas, to optimise the axial resolution in the sampling of the MTF of the MIOL under test, and different pupils, to test the dependence of the optical performance of the MIOL on the eye pupil diameter. Results: The performance and sensitivity of the apparatus is tested with different commercial MIOLs…
Characterization of the biofilm mode of life in the spoilage yeast Brettanomyces bruxellensis
2022
The management of contamination by the spoilage yeast Brettanomyces bruxellensis is a real challenge for the wine industry. The biofilm mode of life, known to increase the resistance of micro-organisms and to allow their persistence in the environment, is a strategy that can be adopted by B. bruxellensis.In this thesis project, microscopic observations revealed the presence of matrix around the cells, an essential element in the definition of a biofilm. The study also revealed that different morphotypes are involved in the structure of the biofilm, in particular filaments forming a network. Chlamydospore-like elements, never described before in B. bruxellensis, were observed within the biof…
Endless forms. Evolutionary scenarios to unravel biodiversity
2020
In this monograph we set out to explore this complex relationship through a series of singular evolutionary scenarios. Some of these scenarios will shed light into phenomena that may at first glance appear inscrutable through the lens of evolution. Our aim is to illustrate the power harnessed by evolutionary biology to tackle some of the most pressing challenges we face as a species, from the diseases that threaten our survival to the recent anthropogenic changes that endanger the only planet we inhabit.
"Niepoprawny recydywista". Krajowy korespondent "Narodowca:" Adam Czekalski
2013
In 1958 the court in Toruń sentenced Adam Czekalski, the national correspondent of the daily Narodowiec published in Lens in France to 3 years of prison. Czekalski was probably the first person tried after October 1956 for maintaining contacts with an emigration magazine and publishing articles abroad. He was convicted for a similar “crime” some years earlier. Today he is unknown and nearly forgotten, despite being a person of strong character. Ailing, he died in prison, a month after being arrested. He was only 57.
Supplementary material 1 from: Di Gristina E, Domina G, Barone G (2021) The alien vascular flora of Stromboli and Vulcano (Aeolian Islands, Italy). I…
2021
Table with the species and subspecies of alien vascular plants present in the islands of Stromboli and Vulcano
Cilvēka biomedicīniskās uzlabošanas ētiskie un sociālie aspekti: Alens Bjūkanens un Nikolass Agars
2019
Darba mērķis ir noskaidrot, vai cilvēku biomedicīniskie uzlabojumi attaisno dažādas iespējami izrietošās sekas, tādējādi pamatojot piekrišanu uzlabojumu attīstīšanai vai arī noraidīšanu. Autoru Alena Bjūkanena un Nikolasa Agara darbi tiek izmantoti kā vadlīnijas, lai demonstrētu divus pretējus viedokļus, atbalstošu un kritizējošu, attiecībā pret cilvēku biomedicīniskajiem uzlabojumiem. Mērķa sasniegšanai tiek risināti trīs uzdevumi. Analizēt biomedicīnisko uzlabojumu specifiski jēdzienisko iedalījumu. Aplūkot aktuālas ētiskās problēmas un pievērsties jautājumam par cilvēka dabu. Kā arī noskaidrot, vai uzlabojumu attīstība ar tās izrietošajām sekām spētu labvēlīgi ietekmēt sabiedrību.
Wavelength tuning of femtosecond pulses generated in nonlinear crystals by using diffractive lenses
2010
We demonstrate that diffractive lenses (DLs) can be used as a simple method to tune the central wavelength of femtosecond pulses generated from second-order nonlinear optical processes in birefringent crystals. The wavelength tunability is achieved by changing the relative distance between the nonlinear crystal and the DL, which acts in a focusing configuration. Besides the many practical applications of the so-generated pulses, the proposed method might be extended to other wavelength ranges by demonstrated similar effects on other nonlinear processes, such as high-order harmonic generation.