Microscopy Research and Technique最新文献

Nonlinear multimode imaging is a versatile tool to realize complex structural and compositional information of biological samples. In this study, we presented a novel integrated multimode nonlinear optical microscopy system by using an Er3 + -doped femtosecond fiber laser. The system could perform second harmonic generation (SHG), third harmonic generation (THG), and three-photon fluorescence (3PEF) imaging modes simultaneously. Using this imaging system, we detected signals from plant cell walls, as well as starch particles in potatoes, chloroplasts in leaves, and onion cells wall-to-membrane linkers: Hechtian strands. Visualizations of skin structures such as stratum corneum, epidermal intercellular structures, hair follicles, and collagen were also achieved by a spatial resolution of 1.67 μm for 3PEF, 1.5 μm for THG, and 2.67 μm for SHG modalities, respectively. After spatial resolution improved by changing a high N.A objective, the system could be used for a variety of biological applications, including in vivo label-free imaging of living animals and deep microscopic imaging.

We present the development of a custom-built structured illumination microscope (SIM) featuring a specially designed transmission diffraction grating. Employing the analog microfilming method, we fabricated transmission diffraction gratings suited to the specific requirements of our system. This robust and cost-effective method allows for the fabrication of diffraction gratings with customized constants, ensuring excellent transmission in both the visible and near-infrared spectra. Additionally, to assess the performance of our system, we measured the resolution in both epifluorescent and super-resolution imaging modalities by applying two independent methods: the conventional resolution measurement using fluorescent beads and the knife-edge technique applied on the MoS₂ monolayer flakes. Both methods confirmed enhancement in the resolution of SIM over the epifluorescent imaging modality. Furthermore, we have successfully demonstrated the capabilities of our microscope by imaging fluorescently labeled astrocytes, specifically targeting the vimentin filament protein within these cells. The super-resolution images reveal fine structures of the vimentin cytoskeleton that remain unresolved in the epifluorescent image.

To evaluate the SBS, DC, and rheological valuation of experimental 1 wt % Cur-loaded-HNPs orthodontic adhesive to bond bracket to enamel surface treated with PA; Nd: YAG, and Er: Cr, YSGG lasers. Two adhesives were prepared experimental adhesive (EA) and EA loaded with 1-wt % Cur-HNP. Surface characterization of Cur-loaded HNP was performed under SEM along with EDS. Specimens were prepared and conditioned with three different strategies PA-gel, Er,Cr:YSGG laser, Nd: YAG laser. Following pretreatment brackets were bonded, samples underwent artificial aging and two samples from each enamel pretreatment regime were assessed under SEM via BSE. SBS testing was achieved via UTM followed by failure analysis using ARI. Modified and unmodified adhesives underwent DC using FTIR and rheological valuation was performed. SBS and DC were assessed using ANOVA and post hoc multiple comparison tests. The highest SBS was seen in the enamel surface treated with PA. The lowest SBS was remarked in the enamel surface treated with Nd: YAG laser. Based on ARI it was noted that modified adhesive containing Cur-HNP exhibited the highest number of failures between 1 and 2. No significant difference was observed between both adhesives in terms of DC. Adhesive modified with 1% Cur-HNP increased viscosity with a decrease in fluidity. The use of Er,Cr:YSGG laser for enamel pretreatment before bracket placement showed potential as a substitute for conventional acid etching, especially when combined with an experimental orthodontic adhesive containing Cur-HNPs.

This paper reports on batch investigations utilizing activated carbon (AC) made from waste Styrofoam to adsorb aluminum (Al³⁺) from aqueous solutions. The AC morphology and structure were examined using Fourier-transform infrared spectroscopy, scanning electron microscopy, and surface area analysis. The factors affecting the performance of adsorption were thoroughly examined. Al³⁺ removal was found to be maximal, that is, 98.65% using 0.2 g of AC at 90 min in a solution of pH 5 maintained at 60°C. Using a flame-mode atomic absorption spectrophotometer (AAnalyst 700, PerkinElmer, USA), the quantity of Al³⁺ in the adsorption solution was measured. For the purpose of studying adsorption, the pseudo-first-order, pseudo-second-order, Langmuir, Freundlich, Temkin, Jovanovich, and Harkins-Jura isotherms were analyzed. The kinetic study shows that the adsorption of Al³⁺ onto Al³⁺ is controlled by pseudo-second-order kinetics. It was observed that among these models, the Langmuir model showed the most favorable fit for the equilibrium data on the removal of Al³⁺ onto AC, with a strong fit (R² = 0.995). The values of thermodynamic parameters such as entropy (ΔS°), Gibbs free energy (ΔG°), and enthalpy (ΔH°) show that the adsorption process is spontaneous and exothermic in nature. In Al³⁺ solutions with low concentrations, the AC exhibited a high adsorption rate. In addition, a check of the error function was performed. To find out if the AC could be utilized again after the adsorption procedure, desorption investigations were carried out. Due to its high adsorption capacity (> 98%) and porous structure, the prepared AC shows significant promise as an alternative adsorbent for Al³⁺. These findings demonstrate that the AC is both effective and efficient in removing Al³⁺ from wastewater.

Atomically resolved scanning tunneling microscope (STM) capable of in situ rotation in a narrow magnet bore has become a long-awaited but challenging technique in the field of strong correlation studies since it can introduce the orientation of the strong magnetic field as a control parameter. This article presents the design and functionality of a piezoelectrically driven rotatable STM (RSTM), operating within a 12 T cryogen-free magnet and achieving a base temperature below 1.8 K, along with spectroscopic capabilities. The system features a compact STM head unit that combines an inertia drive shaft with spring clamping onto the inner wall of a slender piezoelectric scanning tube (PST), enabling both stepper and scanner functionality while reducing the STM's size to 25.5 mm in length and 9 mm in diameter, facilitating rotation within the magnet bore. Another linear piezoelectric motor, driven by a PST, employs a mechanical linkage to convert linear into rotational motion, driving the STM head unit coaxially aligned with it. This mechanism enables STM accurate rotation, offering angle control from 0° to 90° with an ideal closed-loop accuracy of 0.11° per 0.01 V, as determined by a calibrated Hall sensor. Compact and suspended as a standalone unit at the tail of the sample probe, the RSTM is effectively shielded from external mechanical vibrations via secondary counterweight damping. To validate the device performance, the topographic images of graphite and NbSe₂ and their spectroscopy at various magnetic field orientations up to 12 T and temperatures below 1.8 K are obtained. The compact and vibration-resistant RSTM provides compatibility with ultra-high-field water-cooled magnets, facilitating investigations into multiangle magnetic field modulation studies for condensed matter physics.

In this study, in vitro grown Aloe vera L. tissues were used for AgNP synthesis. Adventitious root and callus tissues were grown in MS medium containing 1 mg/L IAA and 1 mg/L NAA. Using A. vera L. leaf, in vitro grown callus, and adventitious roots tissue extracts, AgNPs were synthesized. According to DLS analysis, PDI values and zeta potential values showed that AgNPs from adventitious root were more suitable in terms of size and surface charge. Characterization of adventitious root-derived AgNPs was performed by UV-Vis absorption spectrum, ICP/MS, SEM, FTIR, and XRD. According to HPLC results, catechin, gentisic acid, caffeic acid, coumaric acid, polydatin, coumarin, and ellagic acid were found in adventitious roots. Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC2 7853), MRSA (ATCC 33951) and Staphylococcus aureus (ATCC 6538) strains were used to determine the antibacterial and antibiofilm activity of AgNPs. The highest antibacterial activity was determined against P. aeruginosa. Lower concentrations of AgNPs caused changes in the structure of the biofilm formed by P. aeruginosa, which produced particularly strong biofilms, resulting in failure of biofilm maturation. Accordingly, AgNPs synthesized from Aloe vera L. adventitious roots had antibacterial and antibiofilm activity even at low concentrations against the tested bacterial strains.

In this study, the morphological properties of pollen of 14 species from 9 different sections of the genus Astragalus L. (Fabaceae) distributed in Türkiye were examined, identified, and compared under light microscope (LM) and scanning electron microscope (SEM). Pollen grains of the studied taxa are radially symmetrical and isopolar. Pollen shapes were determined as prolate, subprolate, spheroidal, and prolate-spheroidal. The polar axis lengths of the pollen grains were determined to be between 24.5 and 34.4 μm, and the equatorial axis lengths were determined to be between 22.4 and 27.5 μm. The aperture type of pollen grains is mainly trizonacolporate, rarely trisyncolporate. Colpus are thin and long with acute ends. The shapes of the pores were determined as oblate, suboblate, or oblate-spheroidal. Colpus lengths were found to be between 18.2 and 28.8 μm, and widths were found to be between 2.7 and 7.1 μm. In the studied species, four types of ornamentation were determined according to the differences in the polar region and equatorial region. Type 1: perforate in polar and equatorial regions; Type 2: perforate in polar region, microreticulate in equatorial region; Type 3: microreticulate in polar and equatorial regions; Type 4: psilate-perforate in polar region, microreticulate in equatorial region. Principal component analysis (PCA) and unweighted pair group method using arithmetic average (UPGMA) analyses showed that morphological characters of pollen grains were effective in distinguishing species but could not contribute significantly to a distinction according to sections. Pollen size, colpus characteristics, and ornamentation were determined to be important characteristics that distinguish the studied taxa. This study contributes to Astragalus taxonomy and different sub-branches of palynology.

In this study, a catalyst with Ni-Mo combination was synthesized using the electric heating/reductive tempering method. Nickel (II) nitrate hexahydrate and ammonium molybdate were combined in a ratio of 1.1 in this approach. The mixture was milled into a fine powder. It was heated to 950°C to 1000°C in a seething hood. The disappearance of green shading and emission of brownish-yellow fumes indicated that the reaction was completed. XRD has been used to determine the crystallinity of the combined Ni-Mo amalgam, SEM was used to investigate the surface morphology of the orchestrated Ni-Mo compound, and inductively coupled plasma examinations were carried out to evaluate elemental percentage (%) of the integrated sample of Ni-Mo combination. In addition, an electrical impedance analysis of as-synthesized Ni-Mo alloy was conducted to estimate hydrogen production in an electrochemical reaction. The electrical impedance results indicate that the synthesized Ni-Mo catalyst exhibited an efficient charge-transfer kinetics with a low charge-transfer resistance (5.35 Ω). The onset potential value achieved was 18 mV with overpotential of -100 mV in IM KOH, possessing a turnover frequency of 0.91H₂ s^-1. These findings underscore Ni-Mo catalyst as a promising catalyst for hydrogen generation studies. The results of this study are anticipated to be of potential significant importance in providing a cost-effective approach towards the synthesis of Ni-bimetallic catalyst, which in the future can serve as a promising candidate for applications involving sustainable hydrogen generation. Additionally, the proposed method's study of its greenness using the Analytical Greenness Calculator (AGREE) can help advance the usage of renewable and environmentally friendly energy sources.

The Symplocaceae family comprises 406 species, all of which are classified within a single genus, Symplocos Jacq., which is distributed across multiple continents. In Brazil, this genus is predominantly found in the Atlantic Forest and Cerrado regions and is characterized by the presence of secondary metabolites, such as iridoids, terpenoids, and saponins with biological activities. Moreover, the literature research has unveiled the potential of this genus for antimicrobial, antitumor, and anti-HIV applications. This research conducted morphoanatomical, histochemical studies using light microscopy and scanning electron microscopy (SEM) analysis of the leaves and stems of Symplocos tetrandra (Mart.) Mart. Cross-sections and paradermal were performed. The investigation revealed the presence of prismatic calcium oxalate crystal in petiole and druses calcium oxalate crystals, in petiole and leaf blade. Paracytic stomata on the abaxial surface, lignified pith in the stem, which was detected with the phloroglucinol staining. Oil bodies, uniseriate epidermis, and a thin lipidic cuticle were confirmed with Sudan III. These findings suggest potential anatomical markers for taxonomic classification of the species. The data obtained in this study contributes for species identification, and the presence of metabolites can guide future pharmacological investigation with S. tetrandra.

Russula iqbalii sp. nov. was collected from the District Swat, Pakistan. This species was characterized by its purplish brown pileus having smooth to sulcate-striate margins, stipe smooth to fibrillose and smaller basidiospores with prominent warts, that are isolated to fused in long chains. Comparative morphology and molecular phylogeny based on nrDNA-ITS sequences revealed that it is distinct from previously known taxa in the genus and represents a new species in Russula subsection Maculatinae, section Russula, within the subgenus Russula.