scholarly journals Morphological characterization of virus-like particles in coral reef sponges

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5625 ◽  
Author(s):  
Cecília Pascelli ◽  
Patrick W. Laffy ◽  
Marija Kupresanin ◽  
Timothy Ravasi ◽  
Nicole S. Webster
Keyword(s):  
Morphological Characterization ◽  
Marine Sponges ◽  
Microbial Consortia ◽  
Preparation Methods ◽  
Transmission Electron ◽  
Diverse Communities ◽  
Microbe Interactions ◽  
Microbial Symbionts ◽  
Host Complex

Marine sponges host complex microbial consortia that vary in their abundance, diversity and stability amongst host species. While our understanding of sponge-microbe interactions has dramatically increased over the past decade, little is known about how sponges and their microbial symbionts interact with viruses, the most abundant entities in the ocean. In this study, we employed three transmission electron microscopy (TEM) preparation methods to provide the first comprehensive morphological assessment of sponge-associated viruses. The combined approaches revealed 50 different morphologies of viral-like particles (VLPs) represented across the different sponge species. VLPs were visualized within sponge cells, within the sponge extracellular mesohyl matrix, on the sponge ectoderm and within sponge-associated microbes. Non-enveloped, non-tailed icosahedral VLPs were the most commonly observed morphotypes, although tailed bacteriophage, brick-shaped, geminate and filamentous VLPs were also detected. Visualization of sponge-associated viruses using TEM has confirmed that sponges harbor not only diverse communities of microorganisms but also diverse communities of viruses.

STRUCTURAL AND MORPHOLOGICAL CHARACTERIZATION OF GOLD NANOPARTICLES BY TEM AND DIGITAL CIS TECHNIQUE

2010 ◽  
Vol 09 (05) ◽  
pp. 399-406 ◽  
Author(s):  
A. A. EL-DALY
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Au Nanoparticles ◽  
Morphological Characterization ◽  
Particle Sizes ◽  
Rigid Surface ◽  
Gold Nanocrystals ◽  
Driving Mechanisms ◽  
Transmission Electron

In this paper, we report a convenient and informative procedure for detecting the morphology and surface structure of individual gold nanocrystals using digital Crystal Image Software (CIS) processing of transmission electron microscopy (TEM) image, which comprises coalescence phenomena of these nanoparticles. The results show that the internal structure of Au nanoparticles has a core of gold atoms arranged as a Marks decahedron, surrounded by additional gold–organic compound layers forming a rigid surface layer, and its outer layer comprises four staple motif bridge molecules that resemble handles, formed an unusual pattern. The obtained results improved our understanding of the basics of the coalescence phenomena such as the driving mechanisms acting at different particle sizes. However, these discrete natures of the nanoparticles will assist in the understanding of principles of nanocore assembly and opens a new window for nanoparticles chemistry.

Structural and Morphological Characterization of Ultrathin Films of an Asymmetric Polydiacetylene

1996 ◽  
Vol 440 ◽  
Author(s):  
H. C. Wang ◽  
D. W. Cheong ◽  
J. Kumar ◽  
C. Sung ◽  
S. K. Tripathy
Keyword(s):  
Second Harmonic ◽  
Morphological Characterization ◽  
Lb Films ◽  
Force Microscopy ◽  
Langmuir Blodgett ◽  
Glass Substrates ◽  
Atomic Force ◽  
Transmission Electron ◽  
Air Water Interface

AbstractA soluble, asymmetrically substituted polydiacetylene, poly(BPOD), has been reported to form stable monolayers at the air-water interface by the Langmuir-Blodgett (LB) technique [2]. Preformed polydiacetylene has been deposited onto hydrophobic substrates as multilayers to form second order nonlinear optical thin films. Second harmonic generation was found to increase with the number of layers. From previous atomic force microscopy (AFM) studies backbone orientation along the dipping direction with an interchain spacing of about 5 A° was indicated [2].The film morphology and preferential molecular orientation of these LB films are further investigated by transmission electron microscopy (TEM). A specifically tailored sample preparation method for the ultrathin LB films was used. Multilayer films were deposited on hydrophobic collodion covered glass substrates for this purpose. Electron diffraction was employed to study the crystalline organization of mono and multilayers of LB films as well as cast films.

scholarly journals A Novel Genotype and First Record of Trypanosoma lainsoni in Argentina

Pathogens ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 731
Author(s):  
Anahí G. Díaz ◽  
Paula G. Ragone ◽  
Fanny Rusman ◽  
Noelia Floridia-Yapur ◽  
Rubén M. Barquez ◽  
...  
Keyword(s):  
Host Range ◽  
First Record ◽  
Morphological Characterization ◽  
Pairwise Identity ◽  
Wild Mammals ◽  
Transmission Electron ◽  
Chaco Region ◽  
Veterinary Importance ◽  
First Time

Trypanosomes are a group of parasitic flagellates with medical and veterinary importance. Despite many species having been described in this genus, little is known about many of them. Here, we report a genetic and morphological characterization of trypanosomatids isolated from wild mammals from the Argentine Chaco region. Parasites were morphologically and ultrastructurally characterized by light microscopy and transmission electron microscopy. Additionally, 18s rRNA and gGAPDH genes were sequenced and analyzed using maximum likelihood and Bayesian inference. Morphological characterization showed clear characteristics associated with the Trypanosoma genus. The genetic characterization demonstrates that the studied isolates have identical sequences and a pairwise identity of 99% with Trypanosoma lainsoni, which belongs to the clade of lizards and snakes/rodents and marsupials. To date, this species had only been found in the Amazon region. Our finding represents the second report of T. lainsoni and the first record for the Chaco region. Furthermore, we ultrastructurally described for the first time the species. Finally, the host range of T. lainsoni was expanded (Leopardus geoffroyi, Carenivora, Felidae; and Calomys sp., Rodentia, Cricetidae), showing a wide host range for this species.

scholarly journals Preparation and Characterization of Natural Zeolite Modified with Iron Nanoparticles

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Alvaro Ruíz-Baltazar ◽  
Rodrigo Esparza ◽  
Maykel Gonzalez ◽  
Gerardo Rosas ◽  
Ramiro Pérez
Keyword(s):  
Kinetic Models ◽  
Iron Nanoparticles ◽  
Morphological Characterization ◽  
Adsorption Kinetic ◽  
X Ray Diffraction ◽  
Modified Zeolite ◽  
X Ray ◽  
Transmission Electron ◽  
Zeolite Modification

This study is aimed at investigating the structural and morphological characterization of natural and modified zeolite obtained from the state of Oaxaca (Mexico). Iron nanoparticles were used for the zeolite modification. The iron nanoparticles were loaded on the zeolite surface by homogeneous nucleation. Adsorption kinetic models of pseudo first and second order were surveyed. The characterization of pristine and modified zeolite was performed by Fourier transform infrared (FTIR), transmission electron microscopy (TEM), and X-ray diffraction (XRD). From the results, three main phases were identified: clinoptilolite, mordenite, and feldspar. We could also determine the adsorption capacity of the zeolites by means of adsorption kinetic models.

scholarly journals Morphological characterization of pre- and peri-implantation in vitro cultured, somatic cell nuclear transfer and in vivo derived ovine embryos

Reproduction ◽  
2005 ◽  
Vol 130 (5) ◽  
pp. 681-694 ◽  
Author(s):  
P Tveden-Nyborg ◽  
T T Peura ◽  
K M Hartwich ◽  
S K Walker ◽  
P Maddox-Hyttel
Keyword(s):  
Somatic Cell ◽  
Somatic Cell Nuclear Transfer ◽  
Nuclear Transfer ◽  
Morphological Characterization ◽  
Morphological Development ◽  
Embryonic Disc ◽  
Transmission Electron

The processes of cellular differentiation were studied in somatic cell nuclear transfer (SCNT), in vitro cultured (IVC) and in vivo developed (in vivo) ovine embryos on days 7, 9, 11, 13, 17 and 19. SCNT embryos were constructed from in vitro matured oocytes and granulosa cells, and IVC embryos were produced by in vitro culture of in vivo fertilized zygotes. Most SCNT and IVC embryos were transferred to recipients on day 6 while some remained in culture for day 7 processing. In vivo embryos were collected as zygotes, transferred to intermediate recipients and retransferred to final recipients on day 6. All embryos were processed for examination by light and transmission electron microscopy or immunohistochemical labelling for alpha-1-fetoprotein and vimentin. Overall, morphological development of in vivo embryos was superior to IVC and SCNT embryos. Day 7 and particularly day 9 IVC and SCNT embryos had impaired hypoblast development, some lacking identifiable inner cell masses. On day 11, only in vivo and IVC embryos had developed an embryonic disc, and gastrulation was evident in half of in vivo embryos and one IVC embryo. By day 13, all in vivo embryos had completed gastrulation whereas IVC and SCNT embryos remained retarded. On days 17 and 19, in vivo embryos had significantly more somites and a more developed allantois than IVC and SCNT embryos. We conclude that IVC and particularly SCNT procedures cause a retardation of embryo development and cell differentiation at days 7–19 of gestation.

scholarly journals Sponge–Microbe Interactions on Coral Reefs: Multiple Evolutionary Solutions to a Complex Environment

2021 ◽  
Vol 8 ◽  
Author(s):  
Christopher J. Freeman ◽  
Cole G. Easson ◽  
Cara L. Fiore ◽  
Robert W. Thacker
Keyword(s):  
Coral Reefs ◽  
Marine Sponges ◽  
Future Research ◽  
Ecological Niches ◽  
Trade Offs ◽  
Contemporary Work ◽  
Microbe Interactions ◽  
Microbial Symbionts ◽  
Host Sponge ◽  
Nutritional Benefits

Marine sponges have been successful in their expansion across diverse ecological niches around the globe. Pioneering work attributed this success to both a well-developed aquiferous system that allowed for efficient filter feeding on suspended organic matter and the presence of microbial symbionts that can supplement host heterotrophic feeding with photosynthate or dissolved organic carbon. We now know that sponge-microbe interactions are host-specific, highly nuanced, and provide diverse nutritional benefits to the host sponge. Despite these advances in the field, many current hypotheses pertaining to the evolution of these interactions are overly generalized; these over-simplifications limit our understanding of the evolutionary processes shaping these symbioses and how they contribute to the ecological success of sponges on modern coral reefs. To highlight the current state of knowledge in this field, we start with seminal papers and review how contemporary work using higher resolution techniques has both complemented and challenged their early hypotheses. We outline different schools of thought by discussing evidence of symbiont contribution to both host ecological divergence and convergence, nutritional specificity and plasticity, and allopatric and sympatric speciation. Based on this synthesis, we conclude that the evolutionary pressures shaping these interactions are complex, with influences from both external (nutrient limitation and competition) and internal (fitness trade-offs and evolutionary constraints) factors. We outline recent controversies pertaining to these evolutionary pressures and place our current understanding of these interactions into a broader ecological and evolutionary framework. Finally, we propose areas for future research that we believe will lead to important new developments in the field.

scholarly journals Adsorption of Cellulase on Wrinkled Silica Nanoparticles with Enhanced Inter-Wrinkle Distance

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1799
Author(s):  
Aniello Costantini ◽  
Virginia Venezia ◽  
Giulio Pota ◽  
Aurelio Bifulco ◽  
Valeria Califano ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Morphological Characterization ◽  
Operational Stability ◽  
Successful Outcome ◽  
Glucose Yield ◽  
Transmission Electron ◽  
Ft Ir ◽  
Immobilized Cellulase

Mesoporous silica materials offer a unique opportunity for enzyme immobilization thanks to their properties, such as tuneable pore size, large surface area and easy functionalization. However, a significant enhancement of cellulase enzyme activity entrapped inside the silica pores still represents a challenge. In this work, we immobilized cellulase by adsorption on wrinkled silica nanoparticles (WSNs), obtaining an active and stable biocatalyst. We used pentanol as co-solvent to synthesize WSNs with enhanced inter-wrinkle distance in order to improve cellulase hosting. The physical-chemical and morphological characterization of WSNs and cellulase/WSNs was performed by thermogravimetric (TG), Fourier transform infrared (FT-IR), and transmission electron microscopy (TEM) analyses. The obtained results showed that this matrix generates a favourable microenvironment for hosting cellulase. The results of the catalytic assays and operational stability confirmed the key role of size, morphology and distribution of the pores in the successful outcome of the cellulase immobilization process. The immobilization procedure used allowed preserving most of the secondary structure of the enzyme and, consequently, its catalytic activity. Moreover, the same value of glucose yield was observed for five consecutive runs, showing a high operational stability of the biocatalyst.

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