Super-resolution (SR) microscopy is a cutting-edge method that can provide detailed structural information with high resolution. However, the thickness of the specimen has been a major limitation for SR methods, and large biological structures have posed a challenge. To overcome this, the key step is to optimise sample preparation to ensure optical homogeneity and clarity, which can enhance the capabilities of SR methods for the acquisition of thicker structures. Oocytes are the largest cells in the mammalian body and are crucial objects in reproductive biology. They are especially useful for studying membrane proteins. However, oocytes are extremely fragile and sensitive to mechanical manipulation and osmotic shocks, making sample preparation a critical and challenging step. We present an innovative, simple and sensitive approach to oocyte sample preparation for 3D STED acquisition. This involves alcohol dehydration and mounting into a high refractive index medium. This extended preparation procedure allowed us to successfully obtain a unique two-channel 3D STED SR image of an entire mouse oocyte. By optimising sample preparation, it is possible to overcome current limitations of SR methods and obtain high-resolution images of large biological structures, such as oocytes, in order to study fundamental biological processes. Lay Abstract: Super-resolution (SR) microscopy is a cutting-edge tool that allows scientists to view incredibly fine details in biological samples. However, it struggles with larger, thicker specimens, as they need to be optically clear and uniform for the best imaging results. In this study, we refined the sample preparation process to make it more suitable for SR microscopy. Our method includes carefully dehydrating biological samples with alcohol and then transferring them into a mounting medium that enhances optical clarity. This improved protocol enables high-resolution imaging of thick biological structures, which was previously challenging. By optimizing this preparation method, we hope to expand the use of SR microscopy for studying large biological samples, helping scientists better understand complex biological structures.
Ciele: Sledovat zmeny chirurgicky indukovaného astigmatizmu rohovky a stability umelej vnútroocnej šošovky (IOL) v case po operácii katarakty. Porovnat zamenitelnost meraní medzi automatickým keratorefraktometrom (AKRM) a biometrom. Materiál a metodika: Prospektívna observacná štúdia, v ktorej sme sledovali dané parametre na 25 ociach (25 pacientov) v prvom dni, prvom týždni, prvom a v tretom mesiaci po nekomplikovanej operácii katarakty. Ako nepriamy ukazovatel zmeny stability IOL sme použili astigmatizmus indukovaný IOL (rozdiel medzi refraktometriou a keratometriou). Na analýzu zhody medzi prístrojmi sme použili Blant-Altmanovú metódu. Výsledky: V horeuvedených casových bodoch klesal chirurgicky indukovaný astigmatizmus nasledovne: 0,65 D; 0,62 D; 0,60 D a 0,41 D (v prvom dni, týždni, mesiaci a tretom mesiaci). Astigmatizmus indukovaný zmenou polohy umelej vnútroocnej šošovky sa menil nasledovne: 0,88 D; 0,59 D; 0,44 D a 0,49 D. Zmeny v oboch parametroch boli štatisticky signikantné (p<0,05). Merania hodnoty astigmatizmu aj uhla astigmatizmu nevykazovali štatisticky signikantný rozdiel medzi prístrojmi (p>0,05). Záver: Chirurgicky indukovaný astigmatizmus aj astigmatizmu indukovaný IOL signikantne klesal v case (p < 0,05). Pokles chirurgicky indukovaného astigmatizmu rohovky bol najvýraznejší medzi prvým a tretím mesiacom po operácii. U astigmatizmu indukovaného IOL bol najväcší pokles do prvého mesiaca po operácii. Rozdiely v meraní medzi biometrom a AKRM boli štatisticky nesignikantné, avšak klinická zamenitelnost medzi danými metódami je otázna, obzvlášt u merania uhlu astigmatizmu.
Aims: To analyze changes in surgically induced corneal astigmatism and articial intraocular lens (IOL) stability over time following cataract surgery. To compare the interchangeability of measurements between an automatic keratorefractometer (AKRM) and a biometer. Material and methods: In this prospective observational study, the above-mentioned parameters were collected from 25 eyes (25 subjects) on the first day, first week, first and third month after uncomplicated cataract surgery. We used IOL-induced astigmatism (difference between refractometry and keratometry) as an indirect indicator of IOL stability change. We used the Blant-Altman method to analyze consistency between devices. Results: At the above time points, surgically induced astigmatism (SIA) decreased as follows: 0.65 D; 0.62 D; 0.60 D and 0.41 D (in the first day, week, month and third month respectively). Astigmatism induced by changes of the position of the IOL varied as follows: 0.88 D; 0.59 D; 0.44 D and 0.49 D. Changes in both parameters were statistically significant (p<0.05). Neither the measurements of the astigmatism value nor the astigmatism angle showed a statistically significant difference between the devices (p>0.05). Conclusion: Both surgically induced astigmatism and astigmatism induced by IOL decreased over time, in which both changes were statistically significant. The decrease in SIA was most pronounced between the first and third month after surgery. For IOL-induced astigmatism, the greatest decrease was within the first month after surgery. The differences in measurement between the biometer and AKRM were statistically insignificant, but the clinical interchangeability between the given methods is questionable, especially with regard to measurement of the astigmatism angle.
- MeSH
- Astigmatism * diagnosis etiology MeSH
- Cataract Extraction methods adverse effects MeSH
- Lens Implantation, Intraocular methods adverse effects MeSH
- Cataract MeSH
- Humans MeSH
- Lenses, Intraocular MeSH
- Artificial Lens Implant Migration MeSH
- Prospective Studies MeSH
- Refractometry methods MeSH
- Check Tag
- Humans MeSH
- Publication type
- Observational Study MeSH
Remote detection of hydrogen, without the utilization of electronic component or elevated temperature, is one of the hot topics in the hydrogen technology and safety. In this work, the design and realization of the optical fiber-based hydrogen sensor with unique characteristics are proposed. The proposed sensor is based on the gold-coated multimode fiber, providing the plasmon properties, decorated by the IRMOF-20 layer with high selectivity and affinity toward hydrogen. The IRMOF-20 layer was grown by a surface-assisted technique, and its formation and properties were studied using X-ray photoelectron spectroscopy, Raman, X-ray diffraction, and Brunauer-Emmett-Teller techniques. Simultaneous ellipsometry results indicate the apparent changes of the refractive index of the IRMOF-20 layer due to hydrogen sorption. As results, the presence of hydrogen led to the pronounced changes of plasmon band wavelength position as well as its intensity increase. The proposed hydrogen sensors were favorably distinguished by a high response/recovery rate, excellent selectivity toward the hydrogen, very low temperature dependency, functionality at room or lower temperature, insensitivity toward the humidity, and the presence of CO2, CO, or NO2. Additionally, the proposed hydrogen sensor showed good reversibility, reproducibility, and long-term stability.
Spectropolarimetry of intact plant leaves allows to probe the molecular architecture of vegetation photosynthesis in a non-invasive and non-destructive way and, as such, can offer a wealth of physiological information. In addition to the molecular signals due to the photosynthetic machinery, the cell structure and its arrangement within a leaf can create and modify polarization signals. Using Mueller matrix polarimetry with rotating retarder modulation, we have visualized spatial variations in polarization in transmission around the chlorophyll a absorbance band from 650 nm to 710 nm. We show linear and circular polarization measurements of maple leaves and cultivated maize leaves and discuss the corresponding Mueller matrices and the Mueller matrix decompositions, which show distinct features in diattenuation, polarizance, retardance and depolarization. Importantly, while normal leaf tissue shows a typical split signal with both a negative and a positive peak in the induced fractional circular polarization and circular dichroism, the signals close to the veins only display a negative band. The results are similar to the negative band as reported earlier for single macrodomains. We discuss the possible role of the chloroplast orientation around the veins as a cause of this phenomenon. Systematic artefacts are ruled out as three independent measurements by different instruments gave similar results. These results provide better insight into circular polarization measurements on whole leaves and options for vegetation remote sensing using circular polarization.
- MeSH
- Algorithms * MeSH
- Photosynthesis * MeSH
- Zea mays growth & development metabolism MeSH
- Plant Leaves growth & development metabolism MeSH
- Image Processing, Computer-Assisted methods MeSH
- Microscopy, Polarization methods MeSH
- Refractometry methods MeSH
- Light MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Keywords
- optická biometrie, keratometrie, ultrazvuková biometrie,
- MeSH
- Biometry * methods MeSH
- Diagnostic Techniques, Ophthalmological * MeSH
- Humans MeSH
- Lenses, Intraocular MeSH
- Refractometry methods MeSH
- Ultrasonography methods MeSH
- Check Tag
- Humans MeSH
- Publication type
- Review MeSH
Spektrofotometrická metoda a elektronový mikroskop byly užity pro určení distribuční funkce nanočástic Ag@Fe3O4 podle velikosti ak měření jejich komplexního refrakčního indexu. Částice byly syntetizovány jako složka magneticky kontrolovaných léčiv s antibakteriálními vlastnostmi. Byl navržen algoritmus zpracování výsledků pokusu ke změření velikostí nanočástic (1 až 100 nm).
The spectrophotometric method and the electron microscope have been used to determine the distribution function of Ag@Fe3O4 nanoparticles by sizes and to measure their complex refractive index. These particles have been synthesized as acomponent of magnetically controlled drugs with antibacterial properties. The algorithm of processing the results of the experiment has been designed to measure the sizes of nanoparticles (1–100 nm).
- Keywords
- vepřové sádlo - nejstabilnější, řepkový olej, oxidační produkty, polymerační produkty,
- MeSH
- Brassica napus * chemistry metabolism adverse effects MeSH
- Chromatography * methods utilization MeSH
- Helianthus * chemistry metabolism adverse effects MeSH
- Food Quality * MeSH
- Humans MeSH
- Fatty Acids, Unsaturated * MeSH
- Plant Oils * analysis chemistry metabolism adverse effects MeSH
- Oxidation-Reduction * MeSH
- Refractometry * methods standards utilization MeSH
- Sunflower Oil MeSH
- Statistics as Topic MeSH
- Tocopherols * analysis metabolism MeSH
- Triglycerides * analysis chemistry metabolism adverse effects MeSH
- Fats * analysis chemistry metabolism adverse effects MeSH
- Hot Temperature * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
