Microscopy Research and Technique最新文献

Sulfoxaflor (SFX) is an insecticide that is commonly used for the control of sap-feeding insects. Since SFX is extensively applied globally, it has been implicated in the substantial induction of environmental toxicity. Therefore, in this study, Allium cepa roots have been employed to elucidate the potential cytogenotoxic effects of SFX in non-target cells by examination of mitotic index (MI), chromosomal aberrations (CAs), and DNA damage. Physiological effects of SFX were evaluated by A. cepa root growth inhibition assay, while cytogenotoxic effects were assessed by A. cepa ana-telophase and comet assay. Moreover, DNA binding affinity and binding mode of SFX were examined using molecular docking simulations to shed light on the genotoxic mechanism of action. The half maximal effective concentration (EC₅₀) on the growth of A. cepa cells calculated for SFX was found as 500 mg/L. Moreover, dose- and time-dependent decrease in MI, increase in CAs (disturbed ana-telophase, chromosomal laggards, stickiness, and anaphase chromosome bridge) and DNA damage were observed by the exposure of A. cepa root tips to SFX after 24-, 48-, 72-, and 96-h treatment periods. A 6-bp double-stranded DNA structure containing two intercalation sites (PDB ID: 1Z3F) was used for docking studies. According to DNA docking results, SFX exhibited an energetically more favorable binding affinity with DNA (ΔG = -5.05 kcal/mol) compared with the experimental mutagen methyl methanesulfonate (MMS) (ΔG = -2.94 kcal/mol), and preferentially snugly fits into the minor groove of DNA possessing an intercalation gap, thus, providing valuable mechanistic data into the formation of chromosome aberrations and DNA fragmentation induced by this pesticide in A. cepa.

The development of deep learning algorithms has transformed medical image analysis, especially in brain tumor recognition. This research introduces a robust automatic microbrain tumor identification method utilizing the VGG16 deep learning model. Microscopy magnetic resonance imaging (MMRI) scans extract detailed features, providing multi-modal insights. VGG16, known for its depth and high performance, is utilized for this purpose. The study demonstrates the model's potential for precise and effective diagnosis by examining how well it can differentiate between areas of normal brain tissue and cancerous regions, leveraging both MRI and microscopy data. We describe in full the pre-processing actions taken to improve the quality of input data and maximize model efficiency. A carefully selected dataset, incorporating diverse tumor sizes and types from both microscopy and MRI sources, is used during the training phase to ensure representativeness. The proposed modified VGG19 model achieved 98.81% validation accuracy. Despite good accuracy, interpretation of the result still questionable. The proposed methodology integrates explainable AI (XAI) for brain tumor detection to interpret system decisions. The proposed study uses a gradient explainer to interpret classification results. Comparative statistical analysis highlights the effectiveness of the proposed explainer model over other XAI techniques.

The meniscus effect in cell culture vessels limits the observable areas with phase contrast microscopy. For meniscus effect compensation in microtiter plates (MTPs), we present a method using an LCD to replace the fixed condenser annulus, which enables adaptive annulus shifting based on image analysis. This approach led to an increase in phase contrast area by a factor of 8.3. Utilizing a standard phase contrast microscope, we substituted the static condenser annulus with a transparent LCD that displays an adaptive annulus, which can be repositioned to counteract meniscus-induced refraction across an entire MTP-24 well. We developed image analysis using Bertrand lens images to determine the misalignment between annulus center and phase ring, enabling the calculation of the required annulus shift. Experiments demonstrate the effectiveness of this image analysis technique. The detected shift was translated into new LCD settings through a linear regression model to ensure proper alignment for the following image. We proved that an algorithm based on background brightness yields a reliable metric for assessing phase contrast conditions within well-plates. The proposed approach substantially increased the phase contrast area in 24-well MTPs at 10× magnification from 5.0% with conventional microscopy to 41.9%, thereby restoring phase contrast conditions throughout the well, except near the edges.

The current study provides the first ultrastructural observations on the intraerythrocytic stages of so-called Haemogregarina damiettae and their cytopathological effects on the infected erythrocytes (IEs) in addition to the recording of new morphometric data. The intraerythrocytic stages are attributed to the immature forms or trophozoites (Ts), and mature gamonts (Gs). Ts are typically bowling-bottle shaped with nucleus (TN) occupying its globose part, while Gs are typically banana- shaped. Ts measure 9.60-13.77 (12.53 ± 0.95) × 3.29-5.72 (4.18 ± 0.52) μm, however, Gs measure 14.05-16.13 (15.15 ± 0.60) × 3.38-4.74 (4.06 ± 0.32). Parasite shape index, nuclear/body, and nuclear/cytoplasmic ratio are calculated for both Ts and Gs. Moreover, shape index, nuclear/erythrocytic ratio, nuclear/cytoplasmic ratio are determined for both uninfected erythrocytes (UIEs) and IEs. At ultrastructural level, the parasite exhibited numerous unique features such as the presence of unsutured covering capsule (Ca), intracytoplasmic membraneous structures (ICM), and electron-dense connecting structures (CS) between the degradable cytoplasmic mass (DC) of IEs and parasite itself which are postulated to perform a feeding function. The cytopathological effects on IEs include erythrocytic shape distortion, hypertrophy, dehemoglobinization, as well as nucleus size and shape changes. Erythrocytic karyolysis is confirmed by light and electron microscopy. In addition, all IEs showed characteristics two lateral polar projections or flape-like extensions (FE) supported by microtubules-like structures. Moreover, parasitophorous vacuole membrane (PVM) form in most cases a thick internal lining (IL) of homogenous electron-lucent materials at parasite-facing side and knob-like thickenings (K) of electron-dense materials on erythrocytic cytoplasm-facing side.

Liver cancer is prevalent with the third highest mortality rate globally. The biomechanical properties of cancer cells play a crucial role in their proliferation and differentiation. Studying the morphological and mechanical properties of individual living cells can be helpful for early diagnosis of cancers. Herein, atomic force microscopy (AFM) was used to investigate the effects of Phellinus linteus on hepatocyte cells (HL-7702) and hepatocellular carcinoma cells (SMCC-7721) in terms of morphological and mechanical changes at the nanoscale. The water extract of Phellinus linteus (PLWE) resulted in increased height and surface roughness of SMCC-7721 cells. Also, the PLWE-treated showed that the average adhesion decreased by 1.69 nN and the average Young's modulus increased by 0.379 kPa. Additionally, the SMCC-7721 cells treated with PLWE showed clearly reduced activity compared with HL-7702 cells. This study suggested that Phellinus Linteus could be a potential candidate for selective anti-cancer therapy, providing a new avenue for the treatment of hepatocellular carcinoma.

This study investigates the pollen morphology of 13 taxa of Turkish Gentiana using a statistical approach, contributing to their taxonomy. The aim is to elucidate the palynological characteristics of the taxa and to reveal their contributions to the systematic understanding of the genus Gentiana. The pollen grains are monad, radially symmetrical, isopolar, and tricolporate. The shapes of pollen grains are mostly oblate-spheroidal, occasionally subprolate, and rarely spheroidal. The polar axis ranges from 27.92 to 35.80 μm, the equatorial axis 25.33 to 35.42 μm. The ornamentation type is mostly observed as striate-perforate; however, striate-reticulate, striate, rugulate, reticulate, and rugulate-perforate types have also been observed. The result of numerical analyzes showed that Turkish Gentiana were divided into three groups. The results of PCA analysis, correlated with 84.2% ratio, showed that pollen characters grouped into three principal component. According to PCA analysis, the pollen characters to be used for cluster analysis were determined. Equatorial axis, Clt, Plg, pore diameter, mesocolpium, and apocolpium of the measured pollens are in the first principal component (explains 53.4%). Polar axis, Clg, p/e of the pollen characters are in the second principal component (explains 20.4%). Exine, intine, and Clg/Clt are in the third principal component (explains 10.4%). In conclusion, ornamentation type, polar axis, Clg, Clt, pore diameter, intine, exine, and mesocolpium have been identified as significant and distinguishing characters in taxonomy. Our results support the close relationship among some taxa (i.e., G. gelida and G. boissieri, G. verna subspecies, G. pyrenaica, and G. aquatica).

The genus Wittmackia has 44 species distributed in two centers of diversity: the Brazilian clade and the Caribbean clade. The Brazilian clade includes 29 species, with geographic distribution concentrated in the Northeast of Brazil. This study reports the morphology, ultrastructure, pollen viability and stigma receptivity by different microscopy techniques of 23 species of the genus Wittmackia endemic to Brazil and occurring in Atlantic Forest areas. Pollen morphology was evaluated by scanning electron microscopy and light microscopy by the weak lactic acetolysis method. Histochemical tests were performed with Alexander's solution and fluorescein diacetate. For in vitro germination of pollen grains, two culture media were evaluated. Stigma receptivity was evaluated with hydrogen peroxide and α-naphthyl acetate. The Wittmackia genus presented biporate pollen grains, monads to tetrads, with oblate, suboblate or oblate-spheroidal shape, circular or elliptical scope, and heteropolar or sub-isopolar morphology. The stigmas are of the conduplicate-spiral type, with differences in color and size. In both histochemical tests, high viability was observed, mainly at anthesis, coinciding with in vitro germination. The species presented high enzymatic activity during receptivity, with a very strong positive response, mainly at anthesis. Studies of pollen morphology and viability provide important information for the conservation and genetic improvement of Wittmackia species, also assisting in the taxonomy of the genus and the reproductive success of future controlled crosses.

The Cardueae with about 74 genera and 2500 species is one of the largest tribes of the family Asteraceae. The taxonomy of the Cardueae is complicated and unresolved, as it contains the largest and most diverse genera. The main distribution centers of the Cardueae are in the eastern and western Mediterranean, the western Irano-Turanian region, central Asia, and North Africa. Using pollen morphology can be a useful tool for the identification and delimitation of Cardueae taxa. Therefore, the current study aims to describe the pollen types of tribe Cardueae based on pollen features. Furthermore, the study addresses the relationships among the genera and species based on palynological features as well as species delimitation based on pollen morphology. Pollen morphology of 39 species of Cardueae distributed in 28 genera was examined by scanning electron microscopy. In the present study, statistical analyses and various clustering and ordination methods were provided for palynological data. Based on these results, the members of nine subtribes of Cardueae showed overlap in palynological data. This extreme heterogeneity of relationships among the taxa of tribe Cardueae could be attributed to the large number of taxa and their high morphological diversity. However, suitable palynological features were distinguished for taxonomic differentiation among the species of Cardueae, including pollen shape, size, polar axis to equatorial diameter ratio [P/E], exine sculpture, and spine size. Consequently, six pollen types were identified in the studied taxa of Cardueae.

Nanomaterials have been gaining interest due to their remarkable properties at the nanoscale. The surface area of particles becomes high at the nanoscale because of this virtue, they have been used in a bundle of applications like electronics, biomedical, agriculture, wastewater treatment, semiconductor industry, cosmetics, drug delivery, paints, and so forth. The morphology (size and shape) of nanomaterials plays an important role because each application requires the appropriate morphology for better performance. Generally, there are a few microscopic techniques used to characterize nanomaterial morphology, AFM (atomic force microscopy), TEM (transmission electron microscopy), SEM (scanning electron microscopy), and others. In this review, the principles, operations, advantages, and limitations of these microscopic techniques for nanomaterial morphology characterization have been briefly discussed. The existing difficulties and path forward for the development of these techniques have also been highlighted.

Root-knot nematodes Meloidogyne incognita are sedentary endoparasites with a broad host range which includes economically important medicinal plant species including Turmeric. Turmeric (Curcuma longa) is an important medicinal and aromatic plant (MAPs) grown at Baruasagar town in Jhansi district where root-knot nematodes are a major threat in production fields. The invasion of M. incognita causes serious morphological abnormalities like stunted growth and yellowness of leaves above the ground and the formation of galls at the rhizospheric root, below the ground. The infected root samples of C. longa were collected from three different agro-ecosystem zones of Baruasagar town of Jhansi and processed for optical microscopic investigation. For ascertaining the histopathological modifications, the galled roots were collected and the egg masses were picked from them for culture. The giant cells observed with thicker irregular cell walls and possessed dense cytoplasmic contents with multiple nuclei.