Studying the membrane physiology of filamentous fungi is key to understanding their interactions with the environment and crucial for developing new therapeutic strategies for disease-causing pathogens. However, their plasma membrane has been inaccessible for a micron-sized patch-clamp pipette for pA current recordings due to the rigid chitinous cell wall. Here, we report the first femtosecond IR laser nanosurgery of the cell wall of the filamentous fungi, which enabled patch-clamp measurements on protoplasts released from hyphae.
View Article and Find Full Text PDFWe aimed to collect data on all paediatric patients who were diagnosed with type 1 diabetes mellitus (T1DM) between the years 2000 and 2019 in Serbia and estimate for the first time its prevalence. Also, the trends of diabetes ketoacidosis (DKA) occurrence at the time of diagnosis are monitored. We collected and retrospectively analysed the data of patients <19 years with newly diagnosed T1DM.
View Article and Find Full Text PDFACS Appl Mater Interfaces
August 2020
Surface plasmon resonance (SPR), a promising technology, is beneficial for various applications, such as photothermal conversion, solar cells, photocatalysts, and sensing. However, the SPR performance may be restricted by the 1D- or 2D-distributed hotspots. The bicontinuous interconnected gyroid-structured materials have emerged in light energy conversion due to a high density of 3D-distributed hotspots, ultrahigh light-matter interactions and large scattering cross-section.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2020
Solar steam generation is regarded as a perspective technology, due to its potentials in solar light absorption and photothermal conversion for seawater desalination and water purification. Although lots of steam generation systems have been reported to possess high conversion efficiencies recently, researches of simple, cost-effective, and sustainable materials still need to be done. Here, inspired by natural young sunflower heads' property increasing the temperature of dish-shaped flowers by tracking the sun, we used 3D-structured carbonized sunflower heads as an effective solar steam generator.
View Article and Find Full Text PDFModern document protection relies on the simultaneous combination of many optical features with micron and submicron structures, whose complexity is the main obstacle for unauthorized copying. In that sense, documents are best protected by the diffractive optical elements generated lithographically and mass-produced by embossing. The problem is that the resulting security elements are identical, facilitating mass-production of both original and counterfeited documents.
View Article and Find Full Text PDFWe present an experimental study on ultraslow propagation of matched optical pulses in nondegenerate four wave mixing (FWM) in hot potassium vapor. The main figures of merit, i.e.
View Article and Find Full Text PDFWe describe a new type of photonic material inspired by a Diachrysia chrysitis moth, whose nano-structured wings exhibit a prominent golden color. This is a layered photonic structure with a large refractive index contrast, whose alternating layers are rough at the nanoscale level. Theoretical analysis shows that the scattering and interference interact to enhance the local field within the layers and increase the absorption of the material, particularly in the UV-blue part of the spectrum.
View Article and Find Full Text PDFThermal cameras were constructed long ago, but working principles and complex technologies still limit their resolution, total number of pixels, and sensitivity. We address the problem of finding a new sensing mechanism surpassing existing limits of thermal radiation detection. Here we reveal the new mechanism on the butterfly wing, whose wing-scales act as pixels of an imaging array on a thermal detector.
View Article and Find Full Text PDFPurpose: Glioblastoma multiforme (GBM) is the most aggressive malignant tumor in the brain and no therapy can achieve full recovery/cure. The aim of this study was to identify which factors could improve the survival of operated patients, and to determine which kind of therapy was most successful.
Methods: The study was conducted at the Clinic for Neurosurgery in Nis, Clinical Centre Nis and the Oncology Institute, Clinical Center Nis.
The present study describes utilization of two photon excitation fluorescence (2PE) microscopy for visualization of the hemoglobin in human and porcine erythrocytes and their empty membranes (i.e., ghosts).
View Article and Find Full Text PDFHigh-finesse optical cavities placed under vacuum are foundational platforms in quantum information science with photons and atoms. We study the vacuum-induced degradation of high-finesse optical cavities with mirror coatings composed of SiO₂-Ta₂O₅ dielectric stacks, and present methods to protect these coatings and to recover their initial low loss levels. For separate coatings with reflectivities centered at 370 nm and 422 nm, a vacuum-induced continuous increase in optical loss occurs if the surface-layer coating is made of Ta₂O₅, while it does not occur if it is made of SiO₂.
View Article and Find Full Text PDFWe performed a study of the nonlinear optical properties of chemically purified chitin and insect cuticle using two-photon excited autofluorescence (TPEF) and second-harmonic generation (SHG) microscopy. Excitation spectrum, fluorescence time, polarization sensitivity, and bleaching speed were measured. We have found that the maximum autofluorescence signal requires an excitation wavelength below 850 nm.
View Article and Find Full Text PDFIntroduction: Cervical epidural hematoma is a rare phenomenon in children. MRI scan of the cervical spine is the method of choice in establishing diagnosis and a quick evacuation of hematoma and de- compression.
Case Outline: We present a case of 11-year-old boy whose lower extremities were paralysed after a trivial injury of the cervical spine which he sustained while playing.
We present a field-programmable gate array (FPGA) based device that simultaneously generates two arbitrary analog voltage signals with the maximum sample rate of 1.25 MHz and acquires two analog voltage signals with the maximum sample rate of 2.5 MHz.
View Article and Find Full Text PDFIntroduction: This paper deals with a treating method of trigeminal neuralgia classified so far as idiopathic neuralgias and treated conservatively. The study was aimed at proving the compression of peripheral branches of N. trigeminus in those patients by vascular elements of A.
View Article and Find Full Text PDFWe report on a simple, compact, and robust 780 nm distributed Bragg reflector laser with subkilohertz intrinsic linewidth. An external cavity with optical path length of 3.6 m, implemented with an optical fiber, reduces the laser frequency noise by several orders of magnitude.
View Article and Find Full Text PDFBackground And Objective: Laser phototherapy could be potentially used for cancer treatment, but the mechanisms of laser-induced cell death are not completely understood. Autophagy is the process in which the damaged cellular proteins and organelles are engulfed by and destroyed in acidified multiple-membrane vesicles. The aim of the present study was to investigate the role of autophagy in laser-induced tumor cell death in vitro.
View Article and Find Full Text PDFWe present the Hanle EIT resonances obtained from the various segments of the Gaussian laser beam cross-section, selected by moving the small aperture (placed in front of the detector) radially along the laser beam. Significant differences in the Hanle lineshapes are observed depending on whether the central or outer parts of the Gaussian laser beam are detected. The line narrowing and two counter-sign peaks occur at outer, less intense parts of the beam.
View Article and Find Full Text PDFWe analyze a mechanism of direct laser writing of microlenses. We find that thermal effects and photochemical reactions are responsible for microlens formation on a sensitized gelatin layer. An infrared camera was used to assess the temperature distribution during the microlens formation, while the diffraction pattern produced by the microlens itself was used to estimate optical properties.
View Article and Find Full Text PDFWe study experimentally the creeping penetration of guest (percolating) grains through densely packed granular media in two dimensions. The evolution of the system of the guest grains during the penetration is studied by image analysis. To quantify the changes in the internal structure of the packing, we use Voronoï tessellation and a certain shape factor which is a clear indicator of the presence of different underlying substructures (domains).
View Article and Find Full Text PDFUsing the (2)S(1/2)F(g) = 2 --> (2)P(3/2)F(e) = 3 transition in (87)Rb vapor at room temperature, we study effect of the laser light polarization on the electromagnetically induced absorption (EIA). This work extends the recent study of the behavior of the EIA as a function of the laser ellipticity (Brazhnikov et. al.
View Article and Find Full Text PDFAmplitude and linewidts of the Hanle EIA, obtained from transmission of the laser locked to closed F(g) ? F(e) = F(g) +1 transitions in (85)Rb and(87)Rb, have maximum values at few mW/cm2. Amplitude of the EIA reaches steady value different from zero for higher laser intensities, even for laser intensities of 40 mW/cm(2). Theoretical model of EIA, for the same atomic system as in the experiment, show that the laser intensity, at which maximum of amplitudes and widths occur, depends on the laser detuning.
View Article and Find Full Text PDFIntroduction: Sideropenic anemia is one of the most common nutritional disorders in the world. The children are at higher risk of iron deficiency than adults due to their rapid growth during infancy and relatively higher requirements of iron.
Objective: The objective of our study was to investigate the prevalence of sideropenic anemia in pre-school children and relevant risk factors.
We have experimentally studied electromagnetically induced transparency (EIT) and absorption (EIA) in hot 85Rb atomic vapor using probe and coupling light with comparable power levels. We have shown that strong-probe EIT has different linewidth and appears in fewer configurations than does usual, weak probe EIT. In V-scheme, where optical pumping and saturation are dominant mechanisms, narrow EIT is possible only when a probe is tuned to a closed transition.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
January 2005
We investigate optical emission from low-current discharges in He at very high electric field to gas density ratios E/N between parallel plate electrodes. We also determine the electrical breakdown and the voltage-current behavior at low currents. The E/N are 300 Td to 9 kTd (1 Td = 10(-21) V m2) at pressures times electrode separations p(0)d from 3 to 0.
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