Hasil untuk "Microscopy"

Odir Nunes de Oliveira-Filho, Naara Gabriela Monteiro, Fábio Roberto de Souza-Batista et al.

Abstract Osseointegration can be compromised by bone diseases such as osteoporosis, negatively affecting the quality of life in affected individuals. Rubus coreanus (RC) has shown potential in modulating bone metabolism. Thus, this study aimed to evaluate the impact of RC-functionalized implants on peri-implant bone healing in both healthy (SHAM) and ovariectomized (OVX) rats. The research included both in vitro and in vivo experiments. Initially, osteoblastic cell cultures were used to assess the response to functionalized discs, followed by an in vivo study with forty-eight female Wistar rats, randomly assigned to six groups: SHAM CONV, SHAM RC 200, SHAM RC 400, OVX CONV, OVX RC 200, and OVX RC 400, where CONV refers to a conventional titanium implant and 200 and 400 represent that implant coated with 200 µg and 400 µg of RC. SHAM groups underwent fictitious surgery, while OVX groups underwent ovariectomy. After 30 days, implants were placed in the tibial metaphysis, and the rats were euthanized at 28 days post-implantation. Results indicated that RC maintained cell viability without significantly altering bone microarchitecture. Immunohistochemical analysis revealed notable histological improvements and enhanced marker expression, particularly with the RC 200 surface. Ultrastructural analysis suggested that RC functionalization improves peri-implant bone healing, especially in healthy rats treated with RC 200. In conclusion, implant functionalization with RC, particularly RC 200 significantly enhances peri-implant bone healing, with the most pronounced effects observed in SHAM group.

Chloé Lefevre, Julia Mena-Gómez, Andrea Martin-Vacas et al.

The success of root canal treatment depends on the proper execution of each phase. However, the instrumentation and irrigation phase is especially important. During this phase, the interior of the root canal system must be removed to facilitate the next phase, obturation, achieving the most airtight seal possible, resulting in the success of the endodontic treatment. This study aimed to compare the chelating capacity and smear layer removal effectiveness of two irrigants—17% ethylenediaminetetraacetic acid (EDTA) and 9% hydroxyethylidene bisphosphonate (HEBP)—when activated using two different irrigant activation systems: sonic and ultrasonic. Additionally, the study assessed the relationship between these variables and the average diameter of dentinal tubules in the coronal, middle, and apical thirds of the root canal. A total of 105 single-rooted human teeth were decoronated and instrumented using a rotary system. Teeth were randomly assigned to four experimental groups based on the irrigant (EDTA or HEBP) and the activation method (sonic or ultrasonic). Final irrigation was performed with the corresponding protocol. Samples were analyzed using scanning electron microscopy (SEM). Smear layer removal was quantified using the Carvalho method, and dentinal tubule diameter was measured with image analysis software. Data were statistically analyzed using Kolmogorov–Smirnov and non-parametric tests, with a significance level set at α = 0.05. EDTA showed superior smear layer removal in the coronal and middle thirds, particularly when activated ultrasonically. In contrast, HEBP was more effective in the apical third, especially when used with sonic activation. There were no statistically significant differences in the overall tubule diameter between the two chelating agents; however, HEBP resulted in significantly larger tubule openings in the apical third. Activation systems played a critical role, with ultrasonic irrigation being more effective for EDTA and sonic irrigation favoring HEBP in specific canal regions. The combination of chelating agent and activation system influences both smear layer removal and dentinal tubule morphology. HEBP demonstrated promising results in the apical third with minimal structural damage, supporting its use as a viable alternative to EDTA in continuous chelation protocols.

Ana Sredojevic, Dragan Radivojevic, Steva M. Levic et al.

Apples are the most widely consumed temperate fruit worldwide and are often stored for long-term to ensure year-round availability. However, maintaining fruit quality during storage and subsequent shelf-life remain a significant postharvest challenge. This study investigated the combined effects of the harvest stage, cold storage duration, and shelf-life on the physico-chemical properties of Granny Smith apples. Key quality attributes including texture, maturity indices, color, and starch degradation were evaluated using instrumental methods and Raman microscopy. Fruit quality was affected differently by individual factors and their interactions. Texture parameters showed varied sensitivity: the harvest stage affected several parameters, storage duration had the strongest overall impact, shelf-life influenced a moderate number of parameters, and some were affected by combined factor interactions. Maturity indices were significantly influenced by all factors individually and combined. Color parameters were consistently affected by harvest stage and storage, with shelf-life and interactions influencing fewer parameters. These findings emphasize the complex interplay of factors shaping apple quality after harvest. The study demonstrates the importance of timing harvest and tailoring postharvest handling to maintain apple quality. It also demonstrates the potential of combining traditional and advanced techniques for effective ripeness monitoring.

Shumin LI, Jinbiao GUO, Jinzhi YU et al.

In this investigation, the starch-Lycium barbarum complex (CS-LB) was fabricated using corn starch (CS) and Lycium barbarum (LB) through a high-speed shear method. The stability of the guest molecules was also explored. The influence of shear time, rotational speed, and LB to CS mass ratio on Lycium barbarum pigment (LP) content and its stability were investigated. The CS-LB was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). It was found that the content of LP in the product was 0.99±0.03 mg per gram when the shear time was 1.5 hours, the rotational speed was 12000 r/min, and the mass ratio of LB to CS was 3:1. The SEM results illustrated that the products had an agglomerated morphology. The XRD results showed that the crystal domain of starch particles was destroyed and transformed into amorphous structures due to the high-speed shear treatment, but the CS-LP crystalline structure changed into a V-type, which was promoted by the interaction between CS and active components of LB. The FT-IR results showed that the absorption peak at 3421 cm−1 shifted, indicating that CS and LB were bound through hydrogen bonds. The TGA results showed that the thermal stability of the product was also enhanced, with a mass retention rate of 36% at 600 ℃ for the composite. Thus, the CS-LB could be effectively fabricated by high-speed shear treatment. Additionally, it was found that the composite could effectively reduce the effects of temperature, oxygen, and light on the stability of guest molecules in stability experiments. The shelf-life of guest molecules was also extended, enabling them to perform their related functions better.

Yash Vishnoi, Alok Kumar Trivedi, M.K. Gupta et al.

In the present decades, nanocellulose has been very popular in the field of nanotechnology and is receiving much attention from researchers because of its advantageous physicochemical properties, high aspect ratio, and high specific strength and modulus. The available non-eco-friendly conventional methods for the extraction of nano-crystalline cellulose (NCC) use highly concentrated chemicals and are time-consuming as well. The present adopted cost-effective method for the extraction of nano-crystalline cellulose involves minimum usage of chemicals and is environmentally friendly and relatively fast compared to other conventional methods. The nano-crystalline cellulose from sisal (NCC–S) fibers were extracted by steam explosion-assisted mild concentrated chemical treatments followed by mechanical grinding. The Dynamic light scattering (DLS) and Transmission electron microscopy (TEM) characterization confirmed the size of extracted NCC-S. A high aspect ratio was observed as 19.23, which signifies it could be a promising reinforcing material in developing nanocomposites for advanced applications. An increase in crystallinity and the removal of amorphous materials for NCC-S were confirmed by X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) analysis, respectively. Antibacterial study shows that NCC-S did not show any antibacterial properties against E. coli and S. aureus. The calculated yield of extracted nanocellulose was about 50 %. The aerogel with a porosity of 95.1 % and a density of 0.075 g/cm3 was prepared by vacuum freeze-drying method using extracted nanocellulose and chitosan. The cross-linking network structure and thermal stability of the aerogel were also confirmed by FTIR and TGA analysis respectively.

Jinying Zhang, Yifan Shi, Yexiaotong Zhang et al.

Photoacoustic imaging has emerged as a promising modality for medical imaging since its introduction. Photoacoustic microscopy (PAM), which is based on the photoacoustic effect, combines the advantages of both optical and acoustic imaging modalities. PAM facilitates high-sensitivity, high-resolution, non-contact, and non-invasive imaging by employing optical absorption as its primary contrast mechanism. The ability of PAM to specifically image parameters such as blood oxygenation and melanin content makes it a valuable addition to the suite of modern biomedical imaging techniques. This review aims to provide a comprehensive overview of the diverse technical approaches and methods employed by researchers to enhance the resolution of photoacoustic microscopy. Firstly, the fundamental principles of the photoacoustic effect and photoacoustic imaging will be presented. Subsequently, resolution enhancement methods for both acoustic-resolution photoacoustic microscopy (AR-PAM) and optical-resolution photoacoustic microscopy (OR-PAM) will be discussed independently. Finally, the aforementioned resolution enhancement methods for photoacoustic microscopy will be critically evaluated, and the current challenges and future prospects of this technology will be summarized.

Pawar Abhimanyu, Mungole Arvind, Naktode Kishor

Biosynthesis of metal nanoparticles presents a promising approach for their efficient and environmentally friendly production. In this study, CuO nanoparticles were successfully synthesized by using Rumex nepalensis Spreng. as a bio-reducing agent. The spectroscopic analysis confirmed the crystalline monoclinic structure of the synthesized CuO NPs, with particle sizes ranging from 21 to 97 nm. These biosynthesized CuO NPs exhibited notable antimicrobial activity against diverse microorganisms, suggesting their potential for antimicrobial applications. Moreover, the CuO NPs displayed significant antioxidant activity, demonstrated by their effective scavenging of 1,1-Diphenyl-2-picrylhydrazyl (DPPH) free radicals. This study highlights the straightforward, cost-effective, non-toxic, and robust nature of CuO NPs synthesis using Rumex nepalensis Spreng., offering insights into their potential applications in antimicrobial and antioxidant fields.

Armando G. Salinas, Jeong Oen Lee, Shana M. Augustin et al.

Abstract The development of genetically encoded dopamine sensors such as dLight has provided a new approach to measuring slow and fast dopamine dynamics both in brain slices and in vivo, possibly enabling dopamine measurements in areas like the dorsolateral striatum (DLS) where previously such recordings with fast-scan cyclic voltammetry (FSCV) were difficult. To test this, we first evaluated dLight photometry in mouse brain slices with simultaneous FSCV and found that both techniques yielded comparable results, but notable differences in responses to dopamine transporter inhibitors, including cocaine. We then used in vivo fiber photometry with dLight in mice to examine responses to cocaine in DLS. We also compared dopamine responses during Pavlovian conditioning across the striatum. We show that dopamine increases were readily detectable in DLS and describe transient dopamine kinetics, as well as slowly developing signals during conditioning. Overall, our findings indicate that dLight photometry is well suited to measuring dopamine dynamics in DLS.

Yongfeng Zhao, Ying Fan, Yan Zhang et al.

According to crystal engineering, the pharmaceutical intermediate m-nitrobenzoic acid (MNBA), which contains a carboxylic acid group, was selected as a coformer (CCF) for drug cocrystallization with famotidine (FMT), and a new stable FMT salt cocrystal was synthesized. The salt cocrystals were characterized by scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, infrared spectroscopy, powder X-ray diffraction and X-ray single crystal diffraction. A single crystal structure of FMT–MNBA (1:1) was successfully obtained, and then the solubility and permeability of the newly synthesized salt cocrystal were studied. The results showed that, compared with free FMT, the FMT from the FMT–MNBA cocrystal showed improved permeability. This study provides a synthetic method to improve the permeability of BCS III drugs, which will contribute to the development of low-permeability drugs.

Marcel Reith, Christoph Breuning, Martin Franke et al.

The development of process parameters for electron beam powder bed fusion (PBF-EB) is usually made with simple geometries and uniform scan lengths. The transfer to complex parts with various scan lengths can be achieved by adapting beam parameters such as beam power and scan speed. Under ideal conditions, this adaption results in a constant energy input into the powder bed despite of the local scan length. However, numerous PBF-EB machines show deviations from the ideal situation because the beam diameter is subject to significant changes if the beam power is changed. This study aims to demonstrate typical scaling issues when applying process parameters to scan lengths up to 45 mm using a fourth generation γ-TiAl alloy. Line energy, area energy, return time, and lateral velocity are kept constant during the additive manufacturing process by adjusting beam power and beam velocity to various scan lengths. Samples produced in this way are examined by light microscopy regarding lateral melt pool extension, melt pool depth, porosity, and microstructure. The process-induced aluminum evaporation is measured by electron probe microanalysis. The experiments reveal undesired changes in melt pool geometry, gas porosity, and aluminum evaporation by increasing the beam power. In detail, beam widening is identified as the reason for the change in melt pool dimensions and microstructure. This finding is supported by numerical calculations from a semi-analytic heat conduction model. This study demonstrates that in-depth knowledge of the electron beam diameter is required to thoroughly control the PBF-EB process, especially when scaling process parameters from simply shaped geometries to complex parts with various scan lengths.

Viorica Muşat, Elena Emanuela Herbei, Elena Maria Anghel et al.

Bottom-up approaches in solutions enable the low-temperature preparation of hybrid thin films suitable for printable transparent and flexible electronic devices. We report the obtainment of new transparent PMMA/ZrO₂ nanostructured -building blocks (nBBs) hybrid thin films (61–75 nm) by a modified sol-gel method using zirconium ethoxide, Zr(OEt)₄, and 3-methacryloxypropyl trimethoxysilane (MPS) as a coupling agent and methylmethacrylate monomer (MMA). The effect of low-temperature and UV irradiation on the nBBs gel films is discussed. The thermal behaviors of the hybrid sols and as-deposed gel films were investigated by modulated thermogravimetric (mTG) and differential scanning calorimetry (DSC) analysis. The chemical structure of the resulted films was elucidated by X-ray photoelectron (XPS), infrared (IR) and Raman spectroscopies. Their morphology and crystalline structure were observed by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), and grazing incidence X-ray diffraction. The cured films show zirconia nanocrystallites of 2–4 nm in the hybrid matrix and different self-assembled structures for 160 °C or UV treatment; excellent dielectric behavior, with dielectric constant values within 6.7–17.9, depending on the Zr(OEt)₄:MMA molar ratio, were obtained.

Eleonora Olivotto, Manuela Minguzzi, Stefania D’Adamo et al.

Abstract IKKα and IKKβ are essential kinases for activating NF-κB transcription factors that regulate cellular differentiation and inflammation. By virtue of their small size, chemokines support the crosstalk between cartilage and other joint compartments and contribute to immune cell chemotaxis in osteoarthritis (OA). Here we employed shRNA retroviruses to stably and efficiently ablate the expression of each IKK in primary OA chondrocytes to determine their individual contributions for monocyte chemotaxis in response to chondrocyte conditioned media. Both IKKα and IKKβ KDs blunted both the monocyte chemotactic potential and the protein levels of CCL2/MCP-1, the chemokine with the highest concentration and the strongest association with monocyte chemotaxis. These findings were mirrored by gene expression analysis indicating that the lowest levels of CCL2/MCP-1 and other monocyte-active chemokines were in IKKαKD cells under both basal and IL-1β stimulated conditions. We find that in their response to IL-1β stimulation IKKαKD primary OA chondrocytes have reduced levels of phosphorylated NFkappaB p65pSer536 and H3pSer10. Confocal microscopy analysis revealed co-localized p65 and H3pSer10 nuclear signals in agreement with our findings that IKKαKD effectively blunts their basal level and IL-1β dependent increases. Our results suggest that IKKα could be a novel OA disease target.

Priyanka Singh, Santosh Pandit, VRSS Mokkapati et al.

The use of bacteria as nanofactories for the green synthesis of nanoparticles is considered a sustainable approach, owing to the stability, biocompatibility, high yields and facile synthesis of nanoparticles. The green synthesis provides the coating or capping of biomolecules on nanoparticles surface, which confer their biological activity. In this study, we report green synthesis of silver nanoparticles (AgNPs) by an environmental isolate; named as AgNPs1, which showed 100% 16S rRNA sequence similarity with <i>Solibacillus isronensis.</i> UV/visible analysis (UV/Vis), transmission electron microscopy (TEM), atomic force microscopy (AFM), dynamic light scattering (DLS), and Fourier-transform infrared spectroscopy (FTIR) were used to characterize the synthesized nanoparticles. The stable nature of nanoparticles was studied by thermogravimetric analysis (TGA) and inductively coupled plasma mass spectrometry (ICP-MS). Further, these nanoparticles were tested for biofilm inhibition against <i>Escherichia coli</i> and <i>Pseudomonas aeruginosa</i>. The AgNPs showed minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 3.12 µg/mL and 6.25 µg/mL for <i>E. coli</i>, and 1.56 µg/mL and 3.12 µg/mL for <i>P. aeruginosa</i>, respectively.

Shilpa Gupta, Josh Bromley, Saveez Saffarian

Endosomal sorting complexes required for transport proteins (ESCRT) catalyze the fission of cellular membranes during budding of membrane away from the cytosol. Here we have used Total Internal Reflection Fluorescence (TIRF) microscopy to visualize the recruitment of ESCRTs specifically, ALIX, CHMP4b and VPS4 onto the budding HIV Gag virus-like particles (VLPs). We imaged the budding VLPs with 200 millisecond time resolution for 300 frames. Our data shows three phases for ESCRT dynamics: 1) recruitment in which subunits of ALIX, CHMP4b and VPS4 are recruited with constant proportions on the budding sites of HIV Gag virus like particles for nearly 10 seconds, followed by 2) disassembly of ALIX and CHMP4b while VPS4 signal remains constant for nearly 20 seconds followed by 3) disassembly of VPS4. We hypothesized that the disassembly observed in step 2 was catalyzed by VPS4 and powered by ATP hydrolysis. To test this hypothesis, we performed ATP depletion using (-) glucose medium, deoxyglucose and oligomycin. Imaging ATP depleted cells, we show that the disassembly of CHMP4b and ALIX observed in step 2 is ATP dependent. ATP depletion resulted in the recruitment of approximately 2-fold as many subunits of all ESCRTs. Resuming ATP production in cells, resulted in disassembly of the full ESCRT machinery which had been locked in place during ATP depletion. With some caveats, our experiments provide insight into the formation of the ESCRT machinery at the budding site of HIV during budding.

Rosana de Fátima Gonçalves, Kellen Cristina Mesquita Borges, Murillo Henrique de Matos Rodrigues et al.

<p class="orbitalabstract">Ag₂MoO₄/ZnO heterostructures were synthesized by a co-precipitation method in room temperature. XRD studies have showed the formation of the heterostructures containing wurtzite-type structure with hexagonal phase (ZnO) and spinel-type cubic structures (Ag₂MoO₄₎. The crystal morphologies and sizes were observed by field emission scanning electron microscopy (FE-SEM). The photocatalytic activities were evaluated by the degradation of rhodamine B (RhB) under ultraviolet light irradiation.</p><p class="orbitalabstract"> </p><p class="orbitalabstract">DOI: <a href="http://dx.doi.org/10.17807/orbital.v11i2.1364">http://dx.doi.org/10.17807/orbital.v11i2.1364</a></p><p class="orbitalabstract"> </p>

Tushar Sakpal, Asheesh Kumar, Zachary M. Aman et al.

Fossil fuels are dominant as an energy source, typically producing carbon dioxide (CO₂) and enhancing global climate change. The present work reports the application of low-cost tri-sodium phosphate (TSP) to capture CO₂ from model flue gas (CO₂ + N₂) mixture, in a batch mode and fixed-bed setup. It is observed that TSP has a high CO₂ capture capacity as well as high CO₂ selectivity. At ambient temperature, TSP shows a maximum CO₂ capture capacity of 198 mg CO₂/g of TSP. Furthermore, the CO₂ capture efficiency of TSP over a flue gas mixture was found to be more than 90%. Fresh and spent materials were characterized using powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and Fourier transformed infrared spectroscopy (FTIR). Preliminary experiments were also conducted to evaluate the performance of regenerated TSP. The spent TSP was regenerated using sodium hydroxide (NaOH) and its recyclability was tested for three consecutive cycles. A conceptual prototype for post-combustion CO₂ capture based on TSP material has also been discussed.

Lei Wang, Tingjun Ye, Lianfu Deng et al.

Up to date, little is known about the repair mode of microdamage in osteonal cortical bone resulting from bone screw implantation. In this study, self-tapping titanium cortical bone screws were inserted into the tibial diaphyses of 24 adult male rabbits. The animals were sacrificed at 1 day, 2 weeks, 1 month and 2 months after surgery. Histomorphometric measurement and confocal microscopy were performed on basic fuchsin stained bone sections to examine the morphological characteristics of microdamage, bone resorption activity and spatial relationship between microdamage and bone resorption. Diffuse and linear cracks were coexisted in peri-screw bone. Intracortical bone resorption was significantly increased 2 weeks after screw installation and reach to the maximum at 1 month. There was no significant difference in bone resorption between 1-month and 2-months groups. Microdamage was significantly decreased within 1 month after surgery. Bone resorption was predisposed to occur in the region of <100 µm from the bone-screw interface, where had extensive diffuse damage mixed with linear cracks. Different patterns of resorption cavities appeared in peri-screw bone. These data suggest that 1) the complex microdamage composed of diffuse damage and linear cracks is a strong stimulator for initiating targeted bone remodeling; 2) bone resorption activities taking place on the surfaces of differently oriented Haversian and Volkmann canals work in a team for the repair of extensive microdamage; 3) targeted bone remodeling is a short-term reaction to microdamage and thereby it may not be able to remove all microdamage resulting from bone screw insertion.

Maryam Mansourirad, Mehdi Razzaghi Kashani, Seyed Mohammad Mousavi

Nowadays, due to environmental concerns, there has been great attention to recycling and reclaiming of tires. Different methods have been used for reclaiming or desulfurization of rubber. One of these methods, in which desulfurization of rubber happens with no damage to the polymer structure, is desulfurization by biological microorganisms. In this research the application and performance of thermophilic and sulfur oxidizing bacteria, Acidianus brierleyi for this purpose was investigated. Ground tire rubber was detoxified with organic solvents, and the optimum conditions for growing microorganisms in the existence of rubber powder in the shaker flasks were determined. In order to accelerate the process, the suitable conditions for growth of bacteria and desulfurization in the bioreactor were adopted. Fourier transfer infrared spectroscopy and scanning electron microscopy were employed to characterize desulfurization of bio-treated powder from bioreactor. The results indicated that morphological changes on powder surface and reduction of sulfur bonds have occurred. Samples from bioreactors, with and without bacteria and also untreated rubber powder were compounded with virgin styrene butadiene rubber. Tensile and dynamic properties were investigated using uni-direction tensile test and dynamic-mechanical-thermal analysis, respectively. Although some differences in dynamic-mechanical-thermal properties of samples pointed to stronger interaction between rubber matrix and treated rubber powder, no significant improvements in the mechanical properties of vulcanizates containing A.brierleyi-treated powder were observed. Low concentration of sulfur in rubber vulcanizates, chemical bonds of sulfur, and low efficiency of A. brierleyi in breaking sulfur bonds and reclaiming rubber were considered as the reasons for low efficiency of this treatment process.

Joy I. Odimegwu, Olukemi Odukoya, Ritesh K. Yadav et al.

Dioscorea species is a very important food and drug plant. The tubers of the plant are extensively used in food and drug purposes owing to the presence of steroidal constituent’s diosgenin in the tubers. In the present study, we report for the first time that the leaves of Dioscorea composita and Dioscorea floribunda grown under the field conditions exhibited the presence of multicellular oil glands on the epidermal layers of the plants using stereomicroscopy (SM) and scanning electron microscopy (SEM). Essential oil was also isolated from the otherwise not useful herbage of the plant, and gas chromatographic-mass spectroscopy analysis revealed confirmation of the essential oil constituents. Out of the 76 compounds detected in D. floribunda and 37 from D. composita essential oil, major terpenoids which are detected and reported for Dioscorea leaf essential oil are α-terpinene, nerolidol, citronellyl acetate, farnesol, elemol, α-farnesene, valerenyl acetate, and so forth. Elemol was detected as the major constituent of both the Dioscorea species occupying 41% and 22% of D. Floribunda and D. composita essential oils, respectively. In this paper, we report for the first time Dioscorea as a possible novel bioresource for the essential oil besides its well-known importance for yielding diosgenin.