scholarly journals Loss of CEP70 function affects acrosome biogenesis and flagella formation during spermiogenesis

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Qiang Liu ◽  
Qianying Guo ◽  
Wei Guo ◽  
Shi Song ◽  
Nan Wang ◽  
...  

AbstractThe spermatogenesis process is complex and delicate, and any error in a step may cause spermatogenesis arrest and even male infertility. According to our previous transcriptomic data, CEP70 is highly expressed throughout various stages of human spermatogenesis, especially during the meiosis and deformation stages. CEP70 is present in sperm tails and that it exists in centrosomes as revealed by human centrosome proteomics. However, the specific mechanism of this protein in spermatogenesis is still unknown. In this study, we found a heterozygous site of the same mutation on CEP70 through mutation screening of patients with clinical azoospermia. To further verify, we deleted CEP70 in mice and found that it caused abnormal spermatogenesis, leading to male sterility. We found that the knockout of CEP70 did not affect the prophase of meiosis I, but led to male germ-cell apoptosis and abnormal spermiogenesis. By transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analysis, we found that the deletion of CEP70 resulted in the abnormal formation of flagella and acrosomes during spermiogenesis. Tandem mass tag (TMT)-labeled quantitative proteomic analysis revealed that the absence of CEP70 led to a significant decrease in the proteins associated with the formation of the flagella, head, and acrosome of sperm, and the microtubule cytoskeleton. Taken together, our results show that CEP70 is essential for acrosome biogenesis and flagella formation during spermiogenesis.

Author(s):  
Hui Wang ◽  
Letian Wang ◽  
Shanyu Meng ◽  
Hanxue Lin ◽  
Melanie Correll ◽  
...  

The compatibility of graphene or graphene oxide with its dispersion medium (polymer) plays a critical role in the formation nanocomposite materials with significant property improvements. Environmentally friendly miniemulsion polymerization, which allows a formation of nanoencapsulation in an aqueous phase and high molecular weight polymer/composite production is one promising method. In this study, we screened a series of amphiphilic modifiers and found that the quaternary ammonium (ar-vinyl benzyl) trimethyl ammonium chloride (VBTAC) pending carbon double bonds could effectively modify the graphene oxide (GO) to be compatible with the organophilic monomer. After that, free radical miniemulsion polymerization could successfully synthesize stable latex of exfoliated poly (methyl methacrylate) (PMMA)/ GO nanocomposite. The final latex had an extended storage life and a relatively uniform particle size distribution. X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) analysis of this latex and its films indicated successful encapsulation of exfoliated nano-dimensional graphene oxide inside a polymer matrix.


2019 ◽  
Vol 113 (1) ◽  
pp. 511-517
Author(s):  
Masumeh Ziaee ◽  
Asgar Babamir-Satehi

Abstract Nanostructured silica can be used as a carrier of pesticides to enhance stability and controlled release of agrochemicals with an effective concentration on target pests. Silica nanoparticles (SNPs) were synthesized by sol–gel process and employed as a carrier of three different insecticides including deltamethrin, pyriproxyfen, and chlorpyrifos. The SNPs were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis and the insecticides-loaded in SNPs were characterized by transmission electron microscopy (TEM). The toxicity of insecticides alone and loaded in SNPs was evaluated against small and large larvae of Trogoderma granarium Everts on concrete surfaces. The immediate mortality was counted after 1, 3, and 7 d of exposure, and then surviving individuals were transferred to untreated surfaces for seven more days, with delayed mortality was recorded. Small larvae were more susceptible than large ones on all insecticide treatments. In addition, insecticides loaded in silica nanoparticles were more effective when compared with application of the insecticides alone. For immediate mortality, deltamethrin loaded in SNPs was the most efficient treatment causing 70.5% mortality on small and 55.5% mortality on large larvae after 7 d of exposure to the highest concentration. Pyriproxyfen loaded in SNPs caused low immediate mortality, but the mortality increased in delayed count indicated that the insecticide could control the larvae even after they have been removed from treated surfaces. It can be concluded that loading insecticides in SNPs could significantly increase their insecticidal efficiency, but this increase was compound-dependent.


1982 ◽  
Vol 60 (6) ◽  
pp. 825-837 ◽  
Author(s):  
Jane Robb ◽  
Alexandra Smith ◽  
Lloyd Busch

Plants that are infected with fungi of the species Verticillium frequently develop foliar disease symptoms which may include one or more of the following: flaccidity, drying, chlorosis leading to necrosis, vascular browning, epinasty, and leaf abscission. A number of ultrastructural and chemical alterations occur in the vascular tissues of such leaves: deposition of brown pigments, coating of xylem vessel walls with abnormal material (i.e., lipid-rich coatings or fibrillar coatings), plugging of xylem vessels with gums, gels or tyloses, degeneration of parenchyma cells, and accumulation of abnormal electron dense materials in primary and secondary cell walls. Different host–parasite combinations exhibit different leaf symptoms and different cytological alterations. The purpose of the present survey was to determine whether the extent of any of the possible vascular alterations in leaves could be correlated with the wilting tendency of the host.Chrysanthemums, snapdragons, eggplants, sunflowers, potatoes, sycamore maples and hedge maples were infected with V. dahliae; alfalfa and hops were infected with V. albo-atrum. When leaf symptoms were well advanced, samples were taken from the major lateral leaf veins and were prepared for light (LM) and transmission electron microscopy (TEM) or scanning electron microscopy (SEM). The various types of alterations in the vascular tissues were identified by a correlated LM–TEM method and (or) SEM analysis and for each sample vein the proportion of vessels affected by each type of alteration was calculated. Four leaf samples, each from different plants, were analysed for each host. The visual symptoms, including vascular browning, were estimated subjectively. The degree of leaf flaccidity was correlated positively with the proportion of lipid-coated vessels and inversely with the degree of vascular browning. No other correlations were observed.


2014 ◽  
Vol 625 ◽  
pp. 349-352
Author(s):  
Nor Hazwani Amir Hamzah ◽  
Sujan Chowdhury ◽  
Suriati Sufian ◽  
Abdul Aziz Omar ◽  
Abrar Inayat

Titania nanomaterial flower structure is synthesized through the ionothermal route and is used for the degradation of sulfan blue (SB) through the photo catalysis process. The ionic liquid used is 1-butyl-3-methypyridium dicyanamide ([Bmpm]DCN). The particle sizes and surface morphologies are characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Brunauer–Emmett–Teller (BET). Three types of titania have been compared for their degradation performance, namely commercial titania (TP), titania nanotube (TN), and titania flower (TF). The size of the particle is found to be approximately 33 nm from the FE–SEM analysis. The BET measures the highest surface area of 220 m2 g-1 and pore volume of 0.15 cm3 g-1 for the TF. The degradation of binary dye is more favorable in alkaline solution with pH 14 while varying the dosage of the commercial TiO2 from 0.025–0.2 g reveals an increase in the rate of degradation with optimum dosage is found to be 0.2 g. Results show that TF degradation rate is higher as compared to TP and TN.


1992 ◽  
Vol 260 ◽  
Author(s):  
K. L. Westra ◽  
D. J. Thomson

ABSTRACTAtomic Force microscopy, scanning electron microscopy, and transmission electron microscopy was used to study Al/Si/Cu films sputter deposited at 2 and 45 mTorr. AFM and SEM analysis shows the films to consist of columnar structures commonly seen in PVD deposited thin films, while the TEM analysis showed the films be polycrystalline. Comparing the columnar structures seen in the AFM and SEM study to the grains found in the TEM study, we conclude that the columns consist of single grains. Thus for these films AFM or SEM analysis can be used to determine the grain size. Finally, an AFM scan of a Al/Si/Cu deposited via was performed. The AFM image clearly shows the high resolution of the AFM, while it also illustrates the problems caused by the finite size of the AFM tip.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2617
Author(s):  
Inas A. Ahmed ◽  
Hala S. Hussein ◽  
Ahmed H. Ragab ◽  
Najla AlMasoud ◽  
Ayman A. Ghfar

In the present investigation, green nano-zerovalent copper (GnZVCu), activated carbon (AC), chitosan (CS) and alginate (ALG) nanocomposites were produced and used for the elimination of chromium (VI) from a polluted solution. The nanocomposites GnZVCu/AC-CS-alginate and AC-CS-alginate were prepared. Analysis and characterization were performed by the following techniques: X-ray diffraction, energy dispersive X-ray spectroscopy, scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. The SEM analysis revealed that the nanocomposites are extremely mesoporous, which leads to the greatest adsorption of Cr+6 (i.e., 97.5% and 95%) for GnZVCu/AC-CS-alginate and AC-CS-alginate, respectively. The adsorption efficiency was enhanced by coupling GnZVCu with AC-CS-alginate with a contact time of 40 min. The maximum elimination of Cr+6 with the two nanocomposites was achieved at pH 2. The isotherm model, Freundlich adsorption isotherm and kinetics model and P.S.O.R kinetic models were discovered to be better suited to describe the exclusion of Cr+6 by the nanocomposites. The results suggested that the synthesized nanocomposites are promising for the segregation of Cr+6 from polluted solutions, specially the GnZVCu/AC-CS-alginate nanocomposite.


2021 ◽  
Vol 1 (1) ◽  
pp. 111-114
Author(s):  
Majid Farahmandjou ◽  
Parastoo Khalili

Background and Introduction: Metal oxides (MOs) have been extensively used in a large range of engineering and medical applications. Methods: FeCo nanoparticles (NPs) were successfully synthesized by the solgel method in the presence of a powerful reducing agent-sodium borohydride (NaBH4). The structure, morphology, and optical properties of NPs were analyzed by X-ray diffraction (XRD), field effect scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR) at room temperature. Results: The XRD spectrum showed the body center cubic (BCC) structure of the samples after heat treatment at 500 °C. The SEM analysis exhibited that the particle size of as-synthesized and annealed samples was approximately 40 nm and 22 nm, respectively. Conclusion: The TEM investigations showed the rod-shaped sample of annealed NPs. The optical studies of the FTIR analysis revealed the starching bound of Fe-Co at the frequencies of 673 cm-1, 598 cm-1, and 478 cm-1.


2011 ◽  
Vol 71-78 ◽  
pp. 1237-1241
Author(s):  
Ming Shan Yang ◽  
Lin Kai Li

The organic-inorganic complex nano-particles with core-shell structure were synthesized by in situ emulsion polymerization based on fresh slush pulp of calcium carbonate (CaCO3) nanoparticles and acrylate polymer in this paper. The dispersion and encapsulation of nanoparticles were investigated by transmission electron microscopy (TEM). Unplasticized poly(vinyl chloride)(UPVC) was modified by organic-inorganic complex nanoparticles and the effects of toughening and reinforcing were systematically studied. The results showed that the effects of the reinforcement and toughening of organic-inorganic complex nanoparticles on UPVC were very significant. Especially, scanning electron microscopy(SEM) analysis results indicated that large-fiber drawing and network morphologies coexisted in the system of UPVC by joint modification of nanoparticles with CPE.


1999 ◽  
Vol 5 (S2) ◽  
pp. 1288-1289
Author(s):  
J.P. McNeil ◽  
J.E. Carter ◽  
C.W. Boudreaux ◽  
F. McDonald ◽  
J.A. Tucker ◽  
...  

Spironolactone bodies (SB) were first described in 1963 by Janigan. These laminated, whorled structures are seen in cells of the adrenal zona glomerulosa in patients treated with the drug spironolactone. Spironolactone is an aldosterone antagonist. Hyperaldosteronism may result from excess production by the adrenal cortex. By both light microscopy and transmission electron microscopy (TEM), SB have a distinctive, laminated appearance. Kovacs, et al. observed that SB are composed of cellular constituents. To our knowledge, SB have not been analyzed using scanning electron microscopy (SEM) and electron probe microanalysis technology.An adrenal gland with a 1 cm cortical mass was removed from a 39 year old female and received in 10% buffered formalin. Histologic examination of the mass showed a monotonous population of cells recapitulating zona glomerulosa cells. Intracytoplasmic structures compatible with SB were identified. Portions of the adrenal gland were processed for TEM and SEM analysis.


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1439
Author(s):  
Anabel Díaz-Arca ◽  
Patricia Ros-Tárraga ◽  
María J. Martínez Tomé ◽  
Antonio H. De Aza ◽  
Luis Meseguer-Olmo ◽  
...  

Micro-/nano-structured scaffolds with a weight composition of 46.6% α-tricalcium phosphate (α-TCP)—53.4% silicocarnotite (SC) were synthesized by the polymer replica method. The scanning electron microscopy (SEM) analysis of the scaffolds and natural cancellous bone was performed for comparison purposes. Scaffolds were obtained at three cooling rates via the eutectoid temperature (50 °C/h, 16.5 °C/h, 5.5 °C/h), which allowed the surface nanostructure and mechanical strength to be controlled. Surface nanostructures were characterized by transmission electron microscopy (TEM) and Raman analysis. Both phases α-TCP and SC present in the scaffolds were well-identified, looked compact and dense, and had neither porosities nor cracks. The non-cytotoxic effect was evaluated in vitro by the proliferation ability of adult human mesenchymal stem cells (ah-MSCs) seeded on scaffold surfaces. There was no evidence for cytotoxicity and the number of cells increased with culture time. A dense cell-hydroxyapatite layer formed until 28 days. The SEM analysis suggested cell-mediated extracellular matrix formation. Finally, scaffolds were functionalized with the alkaline phosphatase enzyme (ALP) to achieve biological functionalization. The ALP was successfully grafted onto scaffolds, whose enzymatic activity was maintained. Scaffolds mimicked the micro-/nano-structure and chemical composition of natural cancellous bone by considering cell biology and biomolecule functionalization.


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