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991.
Layer-structured regenerated silk fibroin (SF)/graphene oxide (GO) composite films were fabricated by a facile solution casting method. Fourier transform infrared spectroscopy, X-ray diffraction, and thermal gravity analysis confirmed the successful incorporation and uniform dispersion of graphene oxides in the SF matrix. To visualize GO's effect on the morphological evolution, atomic force microscopic images were recorded in real-time during the composite elongation to establish a correlation between microscopic structural characters and macroscopic mechanical properties. The result showed that the incorporation of graphene oxide into the SF matrix resulted in chain conformational transition, film surface flattening, and mechanical reinforcement. Surface roughness dramatically decreased from 65 to 10 nm, while tensile modulus increased substantially from 8.61 to 22.37 MPa by adding well-dispersed graphene oxide up to 1 wt% into the SF matrix. Through the real-time AFM observation under the horizontal stretching mode, the surface topography of original SF films varied from tori-spherical aggregations to rod-like ones resulting from GO's incorporation. In the meantime, SF's hydrophobicity was also increased, as manifested by contact angle increase from 30.81° to 45.09°. 相似文献
992.
This work was done to assess the role of precursors (agro and graphite) on performance of carbon nanoallotropes-biomacromolecules composite as drug delivery for controlling the release of niacin. In this respect graphene oxide and bagasse-based carbon oxide were synthesized and chelated with chitosan (Cs-GO and Cs-Co). These gel composites were characterized by many techniques [morphology, differential scanning calorimetry, Fourier-transform infrared spectroscopy, swelling, encapsulation efficiency (EE) and loading (L) % of niacin. Another series of experiments was carried out for studying the role of replacing part of carbon nanoallotrope by carboxymethyl cellulose (CMC) on performance of produced drug carries, these systems were coded as Cs-GO-CMC and Cs-Co-CMC. The data showed that, the Cs-GO gel composite provided maximum release of NA, at 5 h, for pH's simulated gastric and intestinal fluids; pH. 2.1 and pH 7.4 (1120 mg/L and 757 mg/L). The incorporation of CMC is not acceptable as it provided low drug release together with burst release of NA-drug, and consequently possible caused tissue irritation or toxicity in the human body. The Cs-GO and Cs-CO systems with relatively low drug loading were recommended for their better controllability system to NA release, which prolonging benefit of human with niacin. The NA release from all investigated gels followed Fickian and non-Fickian diffusion mechanisms. 相似文献
993.
Parul Singh Arun Rawat Bara Al-Jarrah Saras Saraswathi Hoda Gad Mamoun Elawad Khalid Hussain Mohammed A. Hendaus Wesam Al-Masri Rayaz A. Malik Souhaila Al Khodor Anthony K. Akobeng 《International journal of molecular sciences》2021,22(4)
Coeliac disease (CD) and Type 1 diabetes mellitus (T1DM) are immune-mediated diseases. Emerging evidence suggests that dysbiosis in the gut microbiome plays a role in the pathogenesis of both diseases and may also be associated with the development of neuropathy. The primary goal in this cross-sectional pilot study was to identify whether there are distinct gut microbiota alterations in children with CD (n = 19), T1DM (n = 18) and both CD and T1DM (n = 9) compared to healthy controls (n = 12). Our second goal was to explore the relationship between neuropathy (corneal nerve fiber damage) and the gut microbiome composition. Microbiota composition was determined by 16S rRNA gene sequencing. Corneal confocal microscopy was used to determine nerve fiber damage. There was a significant difference in the overall microbial diversity between the four groups with healthy controls having a greater microbial diversity as compared to the patients. The abundance of pathogenic proteobacteria Shigella and E. coli were significantly higher in CD patients. Differential abundance analysis showed that several bacterial amplicon sequence variants (ASVs) distinguished CD from T1DM. The tissue transglutaminase antibody correlated significantly with a decrease in gut microbial diversity. Furthermore, the Bacteroidetes phylum, specifically the genus Parabacteroides was significantly correlated with corneal nerve fiber loss in the subjects with neuropathic damage belonging to the diseased groups. We conclude that disease-specific gut microbial features traceable down to the ASV level distinguish children with CD from T1DM and specific gut microbial signatures may be associated with small fiber neuropathy. Further research on the mechanisms linking altered microbial diversity with neuropathy are warranted. 相似文献
994.
Ivan Kushkevych Blanka Hýov Monika Vít zov Simon K.-M. R. Rittmann 《International journal of molecular sciences》2021,22(8)
This paper is devoted to microscopic methods for the identification of sulfate-reducing bacteria (SRB). In this context, it describes various habitats, morphology and techniques used for the detection and identification of this very heterogeneous group of anaerobic microorganisms. SRB are present in almost every habitat on Earth, including freshwater and marine water, soils, sediments or animals. In the oil, water and gas industries, they can cause considerable economic losses due to their hydrogen sulfide production; in periodontal lesions and the colon of humans, they can cause health complications. Although the role of these bacteria in inflammatory bowel diseases is not entirely known yet, their presence is increased in patients and produced hydrogen sulfide has a cytotoxic effect. For these reasons, methods for the detection of these microorganisms were described. Apart from selected molecular techniques, including metagenomics, fluorescence microscopy was one of the applied methods. Especially fluorescence in situ hybridization (FISH) in various modifications was described. This method enables visual identification of SRB, determining their abundance and spatial distribution in environmental biofilms and gut samples. 相似文献
995.
996.
Manuela Costanzo Elisabetta Esposito Maddalena Sguizzato Maria Assunta Lacavalla Markus Drechsler Giuseppe Valacchi Carlo Zancanaro Manuela Malatesta 《International journal of molecular sciences》2021,22(10)
In this pilot study, ethosomes and transethosomes were investigated as potential delivery systems for cholecalciferol (vitamin D3), whose deficiency has been correlated to many disorders such as dermatological diseases, systemic infections, cancer and sarcopenia. A formulative study on the influence of pharmaceutically acceptable ionic and non-ionic surfactants allowed the preparation of different transethosomes. In vitro cytotoxicity was evaluated in different cell types representative of epithelial, connective and muscle tissue. Then, the selected nanocarriers were further investigated at light and transmission electron microscopy to evaluate their uptake and intracellular fate. Both ethosomes and transethosomes proven to have physicochemical properties optimal for transdermal penetration and efficient vitamin D3 loading; moreover, nanocarriers were easily internalized by all cell types, although they followed distinct intracellular fates: ethosomes persisted for long times inside the cytoplasm, without inducing subcellular alteration, while transethosomes underwent rapid degradation giving rise to an intracellular accumulation of lipids. These basic results provide a solid scientific background to in vivo investigations aimed at exploring the efficacy of vitamin D3 transdermal administration in different experimental and pathological conditions. 相似文献
997.
Grgory Effantin Akiko Fujiwara Takeru Kawasaki Takashi Yamada Guy Schoehn 《International journal of molecular sciences》2021,22(20)
The ϕRSA1 bacteriophage has been isolated from Ralstonia solanacearum, a gram negative bacteria having a significant economic impact on many important crops. We solved the three-dimensional structure of the ϕRSA1 mature capsid to 3.9 Å resolution by cryo-electron microscopy. The capsid shell, that contains the 39 kbp of dsDNA genome, has an icosahedral symmetry characterized by an unusual triangulation number of T = 7, dextro. The ϕRSA1 capsid is composed solely of the polymerization of the major capsid protein, gp8, which exhibits the typical “Johnson” fold first characterized in E. coli bacteriophage HK97. As opposed to the latter, the ϕRSA1 mature capsid is not stabilized by covalent crosslinking between its subunits, nor by the addition of a decoration protein. We further describe the molecular interactions occurring between the subunits of the ϕRSA1 capsid and their relationships with the other known bacteriophages. 相似文献
998.
Carina A. Lämmle Adam Varady Thorsten G. Müller Dr. Caterina Sturtzel Michael Riepl Bettina Mathes Jenny Eichhorst Dr. Anje Sporbert Dr. Martin Lehmann Prof. Dr. Hans-Georg Kräusslich Dr. Martin Distel Dr. Johannes Broichhagen 《Chembiochem : a European journal of chemical biology》2021,22(3):548-556
Selective targeting of DNA by means of fluorescent labeling has become a mainstay in the life sciences. While genetic engineering serves as a powerful technique and allows the visualization of nucleic acid by using DNA-targeting fluorescent fusion proteins in a cell-type- and subcellular-specific manner, it relies on the introduction of foreign genes. On the other hand, DNA-binding small fluorescent molecules can be used without genetic engineering, but they are not spatially restricted. Herein, we report a photocaged version of the DNA dye Hoechst33342 (pcHoechst), which can be uncaged by using UV to blue light for the selective staining of chromosomal DNA in subnuclear regions of live cells. Expanding its application to a vertebrate model organism, we demonstrate uncaging in epithelial cells and short-term cell tracking in vivo in zebrafish. We envision pcHoechst as a valuable tool for targeting and interrogating DNA with precise spatiotemporal resolution in living cells and wild-type organisms. 相似文献
999.
Minsu Kang Jooyong Lee Sangyoon Ko Dr. Sang-Hee Shim 《Chembiochem : a European journal of chemical biology》2021,22(8):1396-1399
Expansion microscopy combined with single-molecule localization microscopy (ExSMLM) has a potential for approaching molecular resolution. However, ExSMLM faces multiple challenges such as loss of fluorophores and proteins during polymerization, digestion or denaturation, and an increase in linkage error arising from the distance between the fluorophore and the target molecule. Here, we introduce a trifunctional streptavidin to link the target, fluorophore and gel matrix via a biotinylizable peptide tag. The resultant ExSMLM images of vimentin filaments demonstrated high labeling efficiency and a minimal linkage error of ∼5 nm. Our ExSMLM provides a simple and practical means for fluorescence imaging with molecular resolution. 相似文献
1000.
Eiichi Hoshino Kazunari Maruta Yasunao Wada Kazuo Mori 《Journal of the American Oil Chemists' Society》1995,72(7):785-791
The interaction of highly purified alkaline protease fromBacillus sp. KSM-K16 with the horny cells of human skin contained in skin grime was directly visualized by electron microscopy. It
became clear that the protease first penetrates the horny cells and then adsorbs, mainly onto the internal structure of the
cells at the initial stage of hydrolysis, and directly hydrolyzes the keratin filaments, though the marginal band surrounding
them retains its original shape. Then, hydrolysate produced from the keratin filaments flows out of the cell, and early in
the hydrolysis process keratin filaments decrease and then disappear, leaving a marginal band, i.e., the cell turns to a hollow
state. As a result, the remaining marginal band loses support from inside the cell, thus promoting cleavage and dispersion.
Until this stage in the protease reaction, the remarkable liberation of hydrolysis products as water-soluble protein does
not occur. 相似文献