scholarly journals Toxicity study of new metal nanoparticles functionalized with fluorescein derivatives as novel image systems

2013 ◽  
Vol 19 (S4) ◽  
pp. 25-26 ◽  
Author(s):  
A. Fernandéz-Lodeiro ◽  
J. Fernandéz-Lodeiro ◽  
C. Nuñez ◽  
E. Oliveira ◽  
H.M. Santos ◽  
...  
Keyword(s):  
The Body ◽  
Limited Information ◽  
Glutathione S Transferase ◽  
Ag Nps ◽  
One Pot ◽  
Novel Treatments ◽  
Transmission Electron ◽  
Dying Cells ◽  
Gastro Intestinal Tract ◽  
In Cells

Nanoparticles in general (NPs) and/or nanomaterials offer remarkable opportunities in industrial production, daily consumables, medicine, biotechnology, electronics and numerous other important commercial and economical areas. Among all these areas, nanomedicine has opened novel treatments for problematic diseases such as viral, genetic, cancer, AIDS, etc. There is limited information available regarding translocation and distribution of NPs in the body and in the environment. Additionally, there is also need for more information on NPs toxicity. Recently has been demonstrated that physiological barriers such as pulmonary and gastro-intestinal tract are affected.The main objective of this work is to use functionalized metal NPs, as emissive agent markers, assess their internalization in cells and evaluate toxicity to cells.Using the emissive two probes synthesized in a one-pot reaction using fluoresceine as chromophore, several gold (Au), round shape, and silver (Ag) NPs (round and triangular shapes) were functionalized in organic media and water by Brust and Turkevish methodology, using tetraoctylammonium bromide (TOABr) as a common stabilizer and sodium borohydride as reducing agent. All has been characterized by UV-vis and emission spectroscopy, transmission electron microscopy (TEM) (Figure 1), and Light scattering. To study the route of internalization into the cell NP-complexes were injected intraperitoneally in fish (Carassius auratus). After 48 hour fish were sampled and sacrificed and liver and intestine processed for histology examination. Additional sub-samples were stored at – 80ºC for enzymatic analysis (glutathione-S-transferase and catalase). Blood was also collected from healthy non-injected fish, for leucocyte separation followed by incubation with the metal NPs and cell viability assays. The presence of emissive NPs in cells was examined by microscopy using a Leica microscope (ATC 2000) adapted for epifluorescence (EF).The microscopy analysis showed that apparently both metal NPs were internalized by leucocytes and intestine cells (Figure 2a and 2b) but apparently not by hepatocytes. However, it is still to clarify if NPs internalization occurred in dead or dying cells only, with more permeable membranes, or also in living cells. Another possibility relates to the detection limits and resolution of the microscope used: the fraction of NPs entering is too low and not detectable with this type of equipment. No significant fluorescence was detected in controls. Viability assays showed higher mortality rates in leucocytes incubated with triangular Ag NPs suggesting that the type of metal and shape have influence in cell toxicity. In general, enzymatic assays indicate low oxidative stress for cells. However, GST results show significant (p > 0.05) differences in livers from fish injected with round Ag NPs. With respect to catalase, significant differences (p > 0.05) were detected in livers from fish injected with round Au NPs. Although the presented results are preliminary they suggest that functionalized NPs are able to penetrate cell membranes. On the other hand, the observed toxicity can be attributed to differences in shape and type of metal NPs.The authors acknowledge the funding by Fundação para a Ciência e Tecnologia through grant PTDC/MAR/119068/2010 and through project no. PEst-C/EQB/LA0006/2011 granted to Requimte.

scholarly journals A Wild Fomes fomentarius for Biomediation of One Pot Synthesis of Titanium Oxide and Silver Nanoparticles for Antibacterial and Anticancer Application

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 622 ◽  
Author(s):  
Suriya Rehman ◽  
Romana Farooq ◽  
Rabindran Jermy ◽  
Sarah Mousa Asiri ◽  
Vijaya Ravinayagam ◽  
...  
Keyword(s):  
Titanium Oxide ◽  
Titanium Isopropoxide ◽  
Ag Nps ◽  
One Pot ◽  
Fomes Fomentarius ◽  
Transmission Electron ◽  
Silver Nps ◽  
Enzyme Combination ◽  
Antibacterial And Anticancer Activity ◽  
20 Nm

The present study offers an alternative method for green synthesis of the formation of two types of nanoparticles (NPs). These NPs, titanium oxide and silver NPs (TiO2 and Ag NPs, respectively), were obtained from the amalgamation of intracellular extract of a wild mushroom, Fomes fomentarius, with aqueous solutions of titanium isopropoxide and silver nitrate, respectively. F. fomentarius was identified phenotypically and by 18S ribosomal RNA gene sequencing (Gene accession no: MK635351). The biosynthesis of TiO2 and Ag NPs was studied and characterized by X-ray diffraction (XRD), diffuse reflectance UV-Visible spectroscopy (DR-UV), fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and transmission electron microscope (TEM). Success was achieved in obtaining NPs of differing sizes and shapes. The antibacterial and anticancer activity of the NPs was significant with morphological damage being caused by both, although Ag NPs (10–20 nm) were found to have profound effects on bacterial and cancer cells in comparison to TiO2 NPs (100–120 nm). These metal NPs, synthesized using wild mushrooms, hold a great potential in biomedicinedue to an effective enzyme combination, which permits them to modify different chemical compounds to less toxic forms, which is required for ecofriendly and safe biomaterials.

An Environmentally Friendly Nanocomposite Polypyrrole@Silver/Reduced Graphene Oxide With High Catalytic Activity for Bacteria and Antibiotics

2021 ◽  
Author(s):  
Chun Liu ◽  
Fangyan Chen ◽  
Yu-bin Tang ◽  
Peng-wei Huo
Keyword(s):  
Graphene Oxide ◽  
High Catalytic Activity ◽  
Ag Nps ◽  
One Pot ◽  
Antimicrobial Efficiency ◽  
Transmission Electron ◽  
Pyrrole Monomer ◽  
Catalytic Stability ◽  
The Stability ◽  
The One

Abstract In this study, PPy@Ag/rGO nanocomposites were successfully synthesized via the one-pot hydrothermal mothed using graphene oxide, pyrrole monomer and silver nitrate. The structures and morphologies of as-obtained PPy@Ag/rGO ternary nanocomposites were systematically investigated by scanning electron microscopy (SEM) and transmission electron microscope (TEM). It was found that the PPy@Ag NPs were well-distributed on the reduction graphene oxide nanoflakes. The minimum inhibitory concentration (MIC) demonstrated that the PPy@Ag/rGO had enhanced antimicrobial efficiency with Gram-negative (Escherichia coli) bacteria compared with that at the same concentration of silver. From liquid antibacterial cycle experiments, the addition of polypyrrole contributes to the stability of nanosilver and reducing the loss of nanosilver. After several cycles, the antibacterial rate of PPy@Ag/rGO nanomaterials can still be maintained above 90%. In addition, the photocatalytic degradation of tetracycline (TC) under visible light displayed that the composite had good photocatalytic activity and catalytic stability.

Otoconia formation in the chick embryo

1983 ◽  
Vol 41 ◽  
pp. 572-573
Author(s):  
C.D. Fermin ◽  
M. Igarashi
Keyword(s):  
Chick Embryo ◽  
Inner Ear ◽  
Gallus Domesticus ◽  
The Body ◽  
Abnormal Behavior ◽  
Intensive Study ◽  
Basic Fuchsin ◽  
Gestational Period ◽  
Sensory Epithelia ◽  
Transmission Electron

Otoconia are microscopic geometric structures that cover the sensory epithelia of the utricle and saccule (gravitational receptors) of mammals, and the lagena macula of birds. The importance of otoconia for maintanance of the body balance is evidenced by the abnormal behavior of species with genetic defects of otolith. Although a few reports have dealt with otoconia formation, some basic questions remain unanswered. The chick embryo is desirable for studying otoconial formation because its inner ear structures are easily accessible, and its gestational period is short (21 days of incubation).The results described here are part of an intensive study intended to examine the morphogenesis of the otoconia in the chick embryo (Gallus- domesticus) inner ear. We used chick embryos from the 4th day of incubation until hatching, and examined the specimens with light (LM) and transmission electron microscopy (TEM). The embryos were decapitated, and fixed by immersion with 3% cold glutaraldehyde. The ears and their parts were dissected out under the microscope; no decalcification was used. For LM, the ears were embedded in JB-4 plastic, cut serially at 5 micra and stained with 0.2% toluidine blue and 0.1% basic fuchsin in 25% alcohol.

Absence of temporal ordering of apoptotic features in heat-shock treated leukemia and lymphoma cell lines

1996 ◽  
Vol 54 ◽  
pp. 758-759
Author(s):  
D. W. Fairbain ◽  
M.D. Standing ◽  
K.L. O'Neill
Keyword(s):  
Heat Shock ◽  
Cell Lines ◽  
Chromatin Condensation ◽  
Membrane Integrity ◽  
Resistant Cell ◽  
Membrane Blebbing ◽  
Late Loss ◽  
Induced Apoptosis ◽  
Dying Cells ◽  
In Cells

Apoptosis is a genetically defined response to physiological stimuli that results in cellular suicide. Features common to apoptotic cells include chromatin condensation, oligonucleosomal DNA fragmentation, membrane blebbing, nuclear destruction, and late loss of ability to exclude vital dyes. These characteristics contrast markedly from pathological necrosis, in which membrane integrity loss is demonstrated early, and other features of apoptosis, which allow a non-inflammatory removal of dead and dying cells, are absent. Using heat shock-induced apoptosis as a model for examining stress response in cells, we undertook to categorize a variety of human leukemias and lymphomas with regard to their response to heat shock. We were also interested in determining whether a common temporal order was followed in cells dying by apoptosis. In addition, based on our previous results, we investigated whether increasing heat load resulted in increased apoptosis, with particular interest in relatively resistant cell lines, or whether the mode of death changed from apoptosis to necrosis.

Images and Applications of Ion Explosion Spike Pits

1990 ◽  
Vol 48 (1) ◽  
pp. 584-585
Author(s):  
P. Fraundorf ◽  
J. Tentschert
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Bulk Material ◽  
Coulomb Repulsion ◽  
The Body ◽  
Atomic Scale ◽  
Early Solar System ◽  
Transmission Electron ◽  
Nuclear Particle ◽  
Particle Tracks

Since the discovery of their etchability in the early 1960‘s, nuclear particle tracks in insulators have had a diverse and exciting history of application to problems ranging from the selective filtration of cancer cells from blood to the detection of 244Pu in the early solar system. Their usefulness stems from the fact that they are comprised of a very thin (e.g. 20-40Å) damage core which etches more rapidly than does the bulk material. In fact, because in many insulators tracks are subject to radiolysis damage (beam annealing) in the transmission electron microscope, the body of knowledge concerning etched tracks far outweighs that associated with latent (unetched) tracks in the transmission electron microscope.With the development of scanned probe microscopies with lateral resolutions on the near atomic scale, a closer look at the structure of unetched nuclear particle tracks, particularly at their point of interface with solid surfaces, is now warranted and we think possible. The ion explosion spike model of track formation, described loosely, suggests that a burst of ionization along the path of a charged particle in an insulator creates an electrostatically unstable array of adjacent ions which eject one another by Coulomb repulsion from substitutional into interstitial sites. Regardless of the mechanism, the ejection process which acts to displace atoms along the track core seems likely to operate at track entry and exit surfaces, with the added feature of mass loss at those surfaces as well. In other words, we predict pits whose size is comparable to the track core width.

Fin Level Defect Isolation Inside a FinFET Using Electron Beam Alteration of Current Flow

2017 ◽  
Author(s):  
H.J. Ryu ◽  
A.B. Shah ◽  
Y. Wang ◽  
W.-H. Chuang ◽  
T. Tong
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Focused Ion Beam ◽  
Current Flow ◽  
Ion Beam ◽  
The Body ◽  
Complete Understanding ◽  
Root Cause ◽  
Transmission Electron ◽  
Defect Isolation

Abstract When failure analysis is performed on a circuit composed of FinFETs, the degree of defect isolation, in some cases, requires isolation to the fin level inside the problematic FinFET for complete understanding of root cause. This work shows successful application of electron beam alteration of current flow combined with nanoprobing for precise isolation of a defect down to fin level. To understand the mechanism of the leakage, transmission electron microscopy (TEM) slice was made along the leaky drain contact (perpendicular to fin direction) by focused ion beam thinning and lift-out. TEM image shows contact and fin. Stacking fault was found in the body of the silicon fin highlighted by the technique described in this paper.

scholarly journals Reproductive biology, embryonic development and matrotrophy in the phylactolaemate bryozoan Plumatella casmiana

2021 ◽  
Author(s):  
Julian Bibermair ◽  
Andrew N. Ostrovsky ◽  
Andreas Wanninger ◽  
Thomas Schwaha
Keyword(s):  
Embryonic Development ◽  
Embryo Sac ◽  
The Body ◽  
Transcellular Transport ◽  
Cell Contacts ◽  
Transmission Electron ◽  
Distal Side ◽  
Early Embryos ◽  
Mesoderm Formation ◽  
Cytoplasmic Processes

AbstractBryozoa is a phylum of aquatic, colonial suspension-feeders within the Lophotrochozoa. In the Phylactolaemata embryonic development occurs in an internal brood sac on the body wall accompanied by extraembryonic nutrition. Owing to previous contradictive descriptions, many aspects of their sexual reproduction require restudy. Consequently, this study analyses embryogenesis of the freshwater bryozoan Plumatella casmiana by serial sections, 3D reconstruction and transmission electron microscopy. Early embryos cleave and soon develop into blastulae with a small central cavity. The mesoderm forms by delamination starting from the distal side towards the proximal end. In later embryos two polypides form on the posterior side that ultimately will be covered by a ciliated mantle in the larva. Embryos increase in size during development and form temporary cell contacts to the embryo sac. Mesodermal cells of the embryo sac show signs of transcellular transport indicating that embryos are nourished by transferring nutrients from the maternal coelom towards the brood cavity. This study clarifies several details such as mesoderm formation and the onset of bud development. Embryos are connected to their respective embryo sacs by a variety of temporary cytoplasmic processes formed by both tissues during embryogenesis, including a ‘placental’ ring zone. Although ultrastructural data of these cell contacts are not entirely conclusive about their function, we suggest that embryos absorb nutrients via the entire surface. The close opposition of embryos to the embryo sac implies placentation as matrotrophic mode in phylactolaemate bryozoans, with embryo sacs acting as placental analogues.

scholarly journals Zinc Oxide and Silver Nanoparticle Effects on Intestinal Bacteria

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2489
Author(s):  
Ami Yoo ◽  
Mengshi Lin ◽  
Azlin Mustapha
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Morphological Changes ◽  
Intestinal Bacteria ◽  
Bacterial Cells ◽  
Ag Nps ◽  
Zno Nps ◽  
Bifidobacterium Animalis ◽  
Transmission Electron

The application of nanoparticles (NPs) for food safety is increasingly being explored. Zinc oxide (ZnO) and silver (Ag) NPs are inorganic chemicals with antimicrobial and bioactive characteristics and have been widely used in the food industry. However, not much is known about the behavior of these NPs upon ingestion and whether they inhibit natural gut microflora. The objective of this study was to investigate the effects of ZnO and Ag NPs on the intestinal bacteria, namely Escherichia coli, Lactobacillus acidophilus, and Bifidobacterium animalis. Cells were inoculated into tryptic soy broth or Lactobacilli MRS broth containing 1% of NP-free solution, 0, 12, 16, 20 mM of ZnO NPs or 0, 1.8, 2.7, 4.6 mM Ag NPs, and incubated at 37 °C for 24 h. The presence and characterization of the NPs on bacterial cells were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS). Membrane leakage and cell viability were assessed using a UV-visible spectrophotometer and confocal electron microscope, respectively. Numbers of treated cells were within 1 log CFU/mL less than those of the controls for up to 12 h of incubation. Cellular morphological changes were observed, but many cells remained in normal shapes. Only a small amount of internal cellular contents was leaked due to the NP treatments, and more live than dead cells were observed after exposure to the NPs. Based on these results, we conclude that ZnO and Ag NPs have mild inhibitory effects on intestinal bacteria.

Vitamin D and sleep duration: Is there a bidirectional relationship?

2020 ◽  
Vol 41 (4) ◽  
Author(s):  
Maryam Mosavat ◽  
Aisling Smyth ◽  
Diana Arabiat ◽  
Lisa Whitehead
Keyword(s):  
Vitamin D ◽  
Sleep Duration ◽  
Vitamin D Supplementation ◽  
The Body ◽  
Bone Homeostasis ◽  
Limited Information ◽  
Physiological Processes ◽  
Vitamin D Levels ◽  
Bidirectional Relationship ◽  
Sleep Length

AbstractVitamin D contributes to numerous physiological processes within the body but primarily calcium and bone homeostasis. Emerging evidence highlights a novel role for vitamin D in maintaining and regulating optimal sleep. Sleep is a known regulator of bone health, highlighting the interconnectedness between vitamin D concentrations, sleep duration and bone metabolism. It is possible that the relationship between sleep length and vitamin D is bidirectional, with vitamin D playing a role in sleep health and conversely, sleep affecting vitamin D levels. Nevertheless, limited information on the direction of the interaction is available, and much remains to be learned concerning the complex relationship between insufficient sleep duration and vitamin D deficiency. Given the potential to implement interventions to improve sleep and vitamin D supplementation, understanding this relationship further could represent a novel way to support and improve health.

scholarly journals Epithelial Protein Lost in Neoplasm, EPLIN, the Cellular and Molecular Prospects in Cancers

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1038
Author(s):  
Jianyuan Zeng ◽  
Wen G. Jiang ◽  
Andrew J. Sanders
Keyword(s):  
The Body ◽  
Early Years ◽  
Actin Binding ◽  
Cell Cycle Gene ◽  
Lim Domain ◽  
The Past ◽  
Concise Review ◽  
Cancerous Cell ◽  
Cytoskeletal Dynamics ◽  
In Cells

Epithelial Protein Lost In Neoplasm (EPLIN), also known as LIMA1 (LIM Domain And Actin Binding 1), was first discovered as a protein differentially expressed in normal and cancerous cell lines. It is now known to be key to the progression and metastasis of certain solid tumours. Despite a slow pace in understanding the biological role in cells and body systems, as well as its clinical implications in the early years since its discovery, recent years have witnessed a rapid progress in understanding the mechanisms of this protein in cells, diseases and indeed the body. EPLIN has drawn more attention over the past few years with its roles expanding from cell migration and cytoskeletal dynamics, to cell cycle, gene regulation, angiogenesis/lymphangiogenesis and lipid metabolism. This concise review summarises and discusses the recent progress in understanding EPLIN in biological processes and its implications in cancer.

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