scholarly journals Physicochemical Properties of A New PEGylated Polybenzofulvene Brush for Drug Encapsulation

Pharmaceutics ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 444 ◽  
Author(s):  
Paolino ◽  
Reale ◽  
Razzano ◽  
Giuliani ◽  
Donati ◽  
...  
Keyword(s):  
Polymer Brush ◽  
Fluorescence Analysis ◽  
Side Chain ◽  
Spontaneous Polymerization ◽  
Pyrene Fluorescence ◽  
Drug Molecules ◽  
Transmission Electron ◽  
Physical Features ◽  
Microscopy Techniques

A new polymer brush was synthesized by spontaneous polymerization of benzofulvene macromonomer 6-MOEG-9-T-BF3k bearing a nona(ethylene glycol) side chain linked to the 3-phenylindene scaffold by means of a triazole heterocycle. The polymer structure was studied by SEC-MALS, NMR spectroscopy, and MALDI-TOF MS techniques, and the results supported the role of oligomeric initiatory species in the spontaneous polymerization of polybenzofulvene derivatives. The aggregation features of high molecular weight poly-6-MOEG-9-T-BF3k-FE were investigated by pyrene fluorescence analysis, dynamic light scattering studies, and transmission electron microscopy, which suggested a tendency towards the formation of spherical objects showing dimensions in the range of 20–200 nm. Moreover, poly-6-MOEG-9-T-BF3k-FE showed an interesting cytocompatibility in the whole concentration range tested that, besides its aggregation features, makes this polybenzofulvene brush a good polymer candidate for nanoencapsulation and delivery of drug molecules. Finally, the photo-physical features of poly-6-MOEG-9-T-BF3k-FE could allow the biodistribution of the resulting drug delivery systems to be monitored by fluorescence microscopy techniques.

Role of Electron Microscopy in Semiconductor Electronic Defects Analysis

1985 ◽  
Vol 46 ◽  
Author(s):  
P. M. Petroff
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Transmission Electron ◽  
Semiconductor Electronic ◽  
Scanning Transmission ◽  
Electronic Defect ◽  
Defects Analysis ◽  
Microscopy Techniques ◽  
Electronic Defects

AbstractA review of the Transmission Electron Microscopy and Scanning Transmission Electron Microscopy techniques used for electronic defect identification is presented. The structural, chemical and STEM based spectroscopy methods for electronic defect analysis are discussed along with selected examples.

Cephalic salivary gland ultrastructure of worker and queen eusocial bees (Hymenoptera, Apidae)

2009 ◽  
Vol 59 (3) ◽  
pp. 299-311 ◽  
Author(s):  
Carminda da Cruz-Landim ◽  
Silvana Beani Poiani
Keyword(s):  
Salivary Glands ◽  
Smooth Endoplasmic Reticulum ◽  
Secretory Cells ◽  
Apical Region ◽  
Transmission Electron ◽  
Basal Plasma ◽  
Eusocial Bees ◽  
Scaptotrigona Postica ◽  
Microscopy Techniques

AbstractEusocial bees present a pair of functional salivary glands in head, the cephalic salivary glands. These glands from workers and queens of two eusocial bee species, Apis mellifera and Scaptotrigona postica, were examined at different life stages using routine transmission electron microscopy techniques to correlate morphology and gland functions. Ultrastructural features of worker and queen glands ducts and secretory units were descriptively compared between species. The duct cells present basal plasma membrane invaginations reaching the apical region. Intercellular space and invaginations contain material of similar electron-density to the basal lamina, suggesting that substances might be directly absorbed from the hemolymph to the gland lumen. The secretory cells are rich in smooth endoplasmic reticulum, mitochondria, Golgi, and vesicles typical of lipid secretion. Secretory cells in S. postica become flattened with age in contrast to A. mellifera, where cells remained cuboidal. Mitochondria are associated with secretory vesicles and may become lipid deposits. A possible role of worker and queen secretion is discussed, taking changes in caste gland morphology and their function in the colony into account.

scholarly journals The Role of the Multi Buffer Layer Technique on the Structural Quality of GaN

2000 ◽  
Vol 5 (S1) ◽  
pp. 398-404 ◽  
Author(s):  
M. Benamara ◽  
Z. Liliental-Weber ◽  
J.H. Mazur ◽  
W. Swider ◽  
J. Washburn ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Buffer Layers ◽  
Structural Quality ◽  
Transmission Electron ◽  
Layer Technique ◽  
Growth Method ◽  
Microscopy Techniques ◽  
Edge Dislocations

Successive growth of thick GaN layers separated by either LT-GaN or LT-AlN interlayers have been investigated by transmission electron microscopy techniques. One of the objectives of this growth method was to improve the quality of GaN layers by reducing the dislocation density at the intermediate buffer layers that act as barriers to dislocation propagation. While the use of LT-AlN results in the multiplication of dislocations in the subsequent GaN layers, the LT-GaN reduces dislocation density. Based upon Burgers vector analysis, the efficiency of the buffer layers for the propagation of the different type of dislocations is presented. LT-AlN layer favor the generation of edge dislocations, leading to a highly defective GaN layer. On the other hand, the use of LT-GaN as intermediate buffer layers appears as a promising method to obtain high quality GaN layer.

Synthesis of Responsive Polymer Brushes on Magnetic Nanoparticles

2013 ◽  
Vol 1453 ◽  
Author(s):  
Kamlesh J. Suthar ◽  
Joseph E. Mowat ◽  
Shankar Balasubramanian ◽  
Muralidhar K. Ghantasala ◽  
Derrick C. Mancini
Keyword(s):  
Magnetic Nanoparticles ◽  
Quantum Interference ◽  
Polymer Brushes ◽  
Magnetic Particles ◽  
Polymer Brush ◽  
Precipitation Method ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Co Precipitation ◽  
Microscopy Techniques

ABSTRACTWe report a simple synthesis technique to attached poly(N-isopropylacrylamide) on magnetic nanoparticles. Fe3O4 magnetic nanoparticles were prepared using co-precipitation method. Nearly monodisperse nanoparticles were separated by terminating surface of Fe3O4 with dopamine followed by careful centrifugation and decantation. NHS/EDC coupling chemistry was employed to attached the carboxylic acid terminated poly(N-isopropylacrylamide) to amine end of dopamine on surface of the magnetic particles. Analysis of the polymer brush layers was conducted using UV-Vis spectroscopy, ATR−FTIR, and Transmission electron microscopy techniques. The magnetic property was investigated using direct current superconducting quantum interference device (DC-SQUID) method.

scholarly journals The Role of the Multi Buffer Layer Technique on the Structural Quality of GaN

1999 ◽  
Vol 595 ◽  
Author(s):  
M. Benamara ◽  
Z. Liliental-Weber ◽  
J.H. Mazur ◽  
W. Swider ◽  
J. Washburn ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Buffer Layers ◽  
Structural Quality ◽  
Transmission Electron ◽  
Layer Technique ◽  
Growth Method ◽  
Microscopy Techniques ◽  
Edge Dislocations

AbstractSuccessive growth of thick GaN layers separated by either LT-GaN or LT-AlN interlayers have been investigated by transmission electron microscopy techniques. One of the objectives of this growth method was to improve the quality of GaN layers by reducing the dislocation density at the intermediate buffer layers that act as barriers to dislocation propagation. While the use of LT-AlN results in the multiplication of dislocations in the subsequent GaN layers, the LT-GaN reduces dislocation density. Based upon Burgers vector analysis, the efficiency of the buffer layers for the propagation of the different type of dislocations is presented. LT-AlN layer favor the generation of edge dislocations, leading to a highly defective GaN layer. On the other hand, the use of LT-GaN as intermediate buffer layers appears as a promising method to obtain high quality GaN layer.

On Future Directions in Pathology

1982 ◽  
Vol 40 ◽  
pp. 274-277
Author(s):  
Benjamin F. Trump ◽  
Irene K. Berezesky ◽  
Raymond T. Jones
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Clinical Pathology ◽  
Future Directions ◽  
Diagnostic Pathology ◽  
The Past ◽  
Transmission Electron ◽  
Organ Systems ◽  
The Many

The role of electron microscopy and associated techniques is assured in diagnostic pathology. At the present time, most of the progress has been made on tissues examined by transmission electron microscopy (TEM) and correlated with light microscopy (LM) and by cytochemistry using both plastic and paraffin-embedded materials. As mentioned elsewhere in this symposium, this has revolutionized many fields of pathology including diagnostic, anatomic and clinical pathology. It began with the kidney; however, it has now been extended to most other organ systems and to tumor diagnosis in general. The results of the past few years tend to indicate the future directions and needs of this expanding field. Now, in addition to routine EM, pathologists have access to the many newly developed methods and instruments mentioned below which should aid considerably not only in diagnostic pathology but in investigative pathology as well.

Transmission Electron Microscopy studies of texture of Cr underlayer of magnetic recording hard disk

1991 ◽  
Vol 49 ◽  
pp. 580-581
Author(s):  
L. Tang ◽  
G. Thomas ◽  
M. R. Khan ◽  
S. L. Duan
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Magnetic Recording ◽  
Magnetic Thin Films ◽  
Magnetic Films ◽  
Substrate Bias ◽  
Epitaxial Relationship ◽  
Transmission Electron

Cr thin films are often used as underlayers for Co alloy magnetic thin films, such as Co1, CoNi2, and CoNiCr3, for high density longitudinal magnetic recording. It is belived that the role of the Cr underlayer is to control the growth and texture of the Co alloy magnetic thin films, and, then, to increase the in plane coercivity of the films. Although many epitaxial relationship between the Cr underlayer and the magnetic films, such as ﹛1010﹜Co/ {110﹜Cr4, ﹛2110﹜Co/ ﹛001﹜Cr5, ﹛0002﹜Co/﹛110﹜Cr6, have been suggested and appear to be related to the Cr thickness, the texture of the Cr underlayer itself is still not understood very well. In this study, the texture of a 2000 Å thick Cr underlayer on Nip/Al substrate for thin films of (Co75Ni25)1-xTix dc-sputtered with - 200 V substrate bias is investigated by electron microscopy.

Transmission Electron Microscopy of Evaporated Perylene Thin Films

1990 ◽  
Vol 48 (2) ◽  
pp. 336-337
Author(s):  
C. Ewins ◽  
J.R. Fryer
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Molecular Electronics ◽  
High Vacuum ◽  
Amorphous Layer ◽  
Electric Heater ◽  
Transmission Electron ◽  
Polycyclic Aromatic

The preparation of thin films of organic molecules is currently receiving much attention because of the need to produce good quality thin films for molecular electronics. We have produced thin films of the polycyclic aromatic, perylene C10H12 by evaporation under high vacuum onto a potassium chloride (KCl) substrate. The role of substrate temperature in determining the morphology and crystallography of the films was then investigated by transmission electron microscopy (TEM).The substrate studied was the (001) face of a freshly cleaved crystal of KCl. The temperature of the KCl was controlled by an electric heater or a cold finger. The KCl was heated to 200°C under a vacuum of 10-6 torr and allowed to cool to the desired temperature. The perylene was then evaporated over a period of one minute from a molybdenum boat at a distance of 10cm from the KCl. The perylene thin film was then backed with an amorphous layer of carbon and floated onto copper microscope grids.

Fine structure and possible functions of the hermaphrodite duct of some pulmonate snails (Mollusca: Gastropoda)

1990 ◽  
Vol 48 (3) ◽  
pp. 68-69
Author(s):  
Alan N. Hodgson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Seminal Vesicle ◽  
Reproductive Biology ◽  
Light Microscope ◽  
Light Microscope Level ◽  
Transmission Electron ◽  
Standard Techniques

The hermaphrodite duct of pulmonate snails connects the ovotestis to the fertilization pouch. The duct is typically divided into three zones; aproximal duct which leaves the ovotestis, the middle duct (seminal vesicle) and the distal ovotestis duct. The seminal vesicle forms the major portion of the duct and is thought to store sperm prior to copulation. In addition the duct may also play a role in sperm maturation and degredation. Although the structure of the seminal vesicle has been described for a number of snails at the light microscope level there appear to be only two descriptions of the ultrastructure of this tissue. Clearly if the role of the hermaphrodite duct in the reproductive biology of pulmonatesis to be understood, knowledge of its fine structure is required.Hermaphrodite ducts, both containing and lacking sperm, of species of the terrestrial pulmonate genera Sphincterochila, Levantina, and Helix and the marine pulmonate genus Siphonaria were prepared for transmission electron microscopy by standard techniques.

THE SOIL PATTERN AND TRENDS IN WEST COAST AGRICULTURE SINCE 1964

1981 ◽  
pp. 19-28 ◽  
Author(s):  
D.B. Wright
Keyword(s):  
West Coast ◽  
Land Development ◽  
Dairy Production ◽  
Waste Land ◽  
Development Costs ◽  
Coastal Soils ◽  
Physical Features ◽  
Soil Pattern ◽  
Great Scope

The physical features, climate and soils of the West Coast are described. Expansion since 1964 of dairy production, sheep and beef cattle numbers, and areas of improved grassland are highlighted, as is the role of the Crown in land development and settlement. While isolation and distance, development costs, river problems, and farmer attitude and knowledge are considered limitations, great scope exists for increased production by the adoption, of more intensive techniques, including horticulture on the best coastal soils, and by development of waste land.

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