Cell morphology, volume, and surface area determinations from multilevel contouring within HVEM micrographs of serial sections and whole-cell mounts

1987 ◽  
Vol 45 ◽  
pp. 588-589
Author(s):  
M. Marko ◽  
A. Leith ◽  
D. Parsons
Keyword(s):  
Surface Area ◽  
Electron Micrographs ◽  
Cell Morphology ◽  
Individual Variation ◽  
Serial Section ◽  
Stereo Pair ◽  
Complex Structures ◽  
Serial Sections ◽  
Surface Areas ◽  
Computer Based

The use of serial sections and computer-based 3-D reconstruction techniques affords an opportunity not only to visualize the shape and distribution of the structures being studied, but also to determine their volumes and surface areas. Up until now, this has been done using serial ultrathin sections.The serial-section approach differs from the stereo logical methods of Weibel in that it is based on the Information from a set of single, complete cells (or organelles) rather than on a random 2-dimensional sampling of a population of cells. Because of this, it can more easily provide absolute values of volume and surface area, especially for highly-complex structures. It also allows study of individual variation among the cells, and study of structures which occur only infrequently.We have developed a system for 3-D reconstruction of objects from stereo-pair electron micrographs of thick specimens.

Serial sections and stereoscopy-complementary approaches to three-dimensional reconstruction

1986 ◽  
Vol 44 ◽  
pp. 36-37 ◽  
Author(s):  
John C. Russ ◽  
Thomas M. Hare
Keyword(s):  
Surface Area ◽  
Serial Section ◽  
Three Dimensional ◽  
Color Images ◽  
Physical Models ◽  
Serial Sections ◽  
Transparent Material ◽  
Modern Computer ◽  
Computer Equipment ◽  
Dimensional Reconstruction

Modelling of three-dimensional structures, either for purposes of geometrical measurement (eg. volume, surface area) or as an aid to visualization, has traditionally been carried out by a variety of different methods. Biologists, who are usually able to conveniently cut sections through their specimens, often make use of serial sections for this purpose. The most common interpretation of serial section photos has been by printing micrographs on transparent material, aligning them, and stacking them up. Occasionally, physical models of lucite, wood, clay or styrofoam have been constructed using the prints as templates, and with the advent of modern computer equipment, some digitization of the sections and their subsequent viewing or plotting with any viewpoint and orientation has enabled researchers to better see the structures represented. There has even been limited use of stereoscopy, that is, producing plots or on-screen color images of the feature outlines from two different viewpoints which can be visually merged to produce the illusion of relief.

Water in sphere-type opal

1969 ◽  
Vol 37 (287) ◽  
pp. 357-361 ◽  
Author(s):  
J. B. Jones ◽  
E. R. Segnit
Keyword(s):  
Electron Microscopy ◽  
Surface Area ◽  
Electron Micrographs ◽  
Thermal Dehydration ◽  
Nitrogen Absorption ◽  
Surface Areas ◽  
Resolution Electron ◽  
Apparent Inconsistency

SummarySurface areas of ‘amorphous’-type opals measured by nitrogen-absorption techniques were not consistent either with the surface area of the spheres of about 2000 Å diameter observable by electron microscopy or with the thermal dehydration data. This apparent inconsistency can be explained in terms of a smaller particulate structure of the order of 100–200 Å shown by higher resolution electron micrographs. This structure also accounts for a marked shrinkage shown in dilatometer curves of this type of opal.

THREE DIMENSIONAL RECONSTRUCTION OF QUADRIVALENTS AND MAPPING OF TRANSLOCATION BREAKPOINTS OF THE MOUSE TRANSLOCATIONS T(2;8) 26H AND T(9;17)138Ca

1980 ◽  
Vol 22 (2) ◽  
pp. 261-270 ◽  
Author(s):  
Anthony H. C. Choi
Keyword(s):  
Electron Micrographs ◽  
Serial Section ◽  
Three Dimensional ◽  
Serial Sections ◽  
Three Dimensional Reconstruction ◽  
Reciprocal Translocations ◽  
Mammalian Oocyte ◽  
Dimensional Reconstruction ◽  
Translocation Breakpoints ◽  
Serial Section Reconstruction

Three dimensional reconstruction from electron micrographs of serial sections reveals 18 synaptonemal complexes and a cross-shaped quadrivalent in the mouse pachytene oocytes of the heterozygous reciprocal translocations T(2;8)26H and T(9;17)138Ca. The unambiguous identification of translocation breakpoints on the quadrivalents has allowed the mapping of the translocation breakpoints on the chromosomes. The translocation breakpoints of T(2;8)26H are mapped at 73% and 45% from the telocentric centromeres of chromosomes 2 and 8, while those of T(9;17)138Ca are mapped at 41% and 45% from the telocentric centromeres of chromosomes 9 and 17 respectively. This report represents the first study of serial section reconstruction of a mammalian oocyte.

scholarly journals Tuning the hierarchical pore structure of graphene oxide through dual thermal activation for high-performance supercapacitor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jeongpil Kim ◽  
Jeong-Hyun Eum ◽  
Junhyeok Kang ◽  
Ohchan Kwon ◽  
Hansung Kim ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Pore Structure ◽  
Specific Capacitance ◽  
Surface Area ◽  
Thermal Annealing ◽  
High Performance ◽  
Annealing Process ◽  
Supercapacitor Electrode ◽  
Simple Method ◽  
Surface Areas

AbstractHerein, we introduce a simple method to prepare hierarchical graphene with a tunable pore structure by activating graphene oxide (GO) with a two-step thermal annealing process. First, GO was treated at 600 °C by rapid thermal annealing in air, followed by subsequent thermal annealing in N2. The prepared graphene powder comprised abundant slit nanopores and micropores, showing a large specific surface area of 653.2 m2/g with a microporous surface area of 367.2 m2/g under optimized conditions. The pore structure was easily tunable by controlling the oxidation degree of GO and by the second annealing process. When the graphene powder was used as the supercapacitor electrode, a specific capacitance of 372.1 F/g was achieved at 0.5 A/g in 1 M H2SO4 electrolyte, which is a significantly enhanced value compared to that obtained using activated carbon and commercial reduced GO. The performance of the supercapacitor was highly stable, showing 103.8% retention of specific capacitance after 10,000 cycles at 10 A/g. The influence of pore structure on the supercapacitor performance was systematically investigated by varying the ratio of micro- and external surface areas of graphene.

scholarly journals EXTIRPATION OF THE THYMUS IN THE GUINEA PIG

1917 ◽  
Vol 25 (1) ◽  
pp. 129-152 ◽  
Author(s):  
Edwards A. Park
Keyword(s):  
Guinea Pig ◽  
Serial Section ◽  
Guinea Pigs ◽  
Close Association ◽  
Main Lobe ◽  
Technical Error ◽  
Serial Sections ◽  
Pharyngeal Pouch ◽  
The Third ◽  
Third Pharyngeal Pouch

1. Accessory lobes of thymus, derived from the third pharyngeal pouch, occurring in close association with the parathyroids from the third pouch, were found in serial section of the cervical tissues of eleven out of fourteen guinea pigs, and probably would have been found in all fourteen but for a technical error. 2. It is probable, therefore, that accessory lobes of thymus having this situation and origin are usually, if not always, present in the guinea pig. 3. Additional accessory lobes of thymus belonging to, but at some distance from the main lobe were also present in several of the animals. 4. The discovery of these accessory lobes makes it certain that the guinea pig is unsuitable material for complete thymectomy, and probably complete extirpation of the thymus in this animal is rarely, if ever accomplished. 5. The extirpation experiments of previous investigators in the guinea pig must now be regarded as partial extirpations, and their results interpreted in that light. 6. Extirpation of the thymus in the guinea pig produced no changes in the writer's experiments. 7. The study of the serial sections of the cervical tissues of the guinea pig indicates that Ruben's statements regarding the parathyroid derived from the fourth pharyngeal pouch in the guinea pig are correct,—that it is much smaller than parathyroid III, may be rudimentary, and is sometimes absent at least on one side. 8. No accessory lobe of thymus was found accompanying the parathyroid from the fourth pouch, a finding also bearing out Ruben's statement that no thymus anlarge springs from the fourth pouch in the guinea pig.

The new face of large dams in the 21st century

2021 ◽  
Author(s):  
Atal Ahmadzai
Keyword(s):  
Surface Area ◽  
Aquatic Ecosystems ◽  
Energy Demand ◽  
Environmental Aspects ◽  
Water Insecurity ◽  
Surface Areas ◽  
Large Dams ◽  
Physical Attributes ◽  
Under Construction ◽  
Ecological Disturbances

Alerted by increasing water insecurity and energy demand, countries, mainly in the Global South, are building dams of unprecedented magnitude. Hundreds of large dams (≥ 100 metres) have been constructed since 2000, with hundreds more under construction. Analyses of the physical attributes of these dams present a concerning image. While they create expansive reservoirs with large surface areas, they have inefficient surface area-to-volume ratios ('S2VR'). Their unprecedented size and the reservoirs’ expansive surface area, indicate severe environmental costs, mainly through ecological disturbances to the (riverine) aquatic ecosystems; and greenhouse gas emissions (GHG). Other ecological costs due to the larger S2VR include a high evaporation rate and compromised biodiversity of a wider area, both up- and downstream. The safety and environmental aspects of these large dams should be robustly scrutinised.

scholarly journals The Effects of Methane Storage Capacity Using Upgraded Activated Carbon by KOH

2018 ◽  
Vol 8 (9) ◽  
pp. 1596 ◽  
Author(s):  
Jung Park ◽  
Gi Lee ◽  
Sang Hwang ◽  
Ji Kim ◽  
Bum Hong ◽  
...  
Keyword(s):  
Surface Area ◽  
Storage Capacity ◽  
Activated Carbons ◽  
Chemical Activation ◽  
High Surface ◽  
Heat Of Adsorption ◽  
Low Grade ◽  
Surface Areas ◽  
Ch4 Adsorption ◽  
Ch4 Storage

In this study, a feasible experiment on adsorbed natural gas (ANG) was performed using activated carbons (ACs) with high surface areas. Upgraded ACs were prepared using chemical activation with potassium hydroxide, and were then applied as adsorbents for methane (CH4) storage. This study had three principal objectives: (i) upgrade ACs with high surface areas; (ii) evaluate the factors regulating CH4 adsorption capacity; and (iii) assess discharge conditions for the delivery of CH4. The results showed that upgraded ACs with surface areas of 3052 m2/g had the highest CH4 storage capacity (0.32 g-CH4/g-ACs at 3.5 MPa), which was over two times higher than the surface area and storage capacity of low-grade ACs (surface area = 1152 m2/g, 0.10 g-CH4/g-ACs). Among the factors such as surface area, packing density, and heat of adsorption in the ANG system, the heat of adsorption played an important role in controlling CH4 adsorption. The released heat also affected the CH4 storage and enhanced available applications. During the discharge of gas from the ANG system, the residual amount of CH4 increased as the temperature decreased. The amount of delivered gas was confirmed using different evacuation flow rates at 0.4 MPa, and the highest efficiency of delivery was 98% at 0.1 L/min. The results of this research strongly suggested that the heat of adsorption should be controlled by both recharging and discharging processes to prevent rapid temperature change in the adsorbent bed.

scholarly journals The Peroneus Brevis and Plantar Fascia Insertions Are Related to Proximal Fifth Metatarsal Fractures

2017 ◽  
Vol 2 (3) ◽  
pp. 2473011417S0001
Author(s):  
Ali Hosseini ◽  
Pim Van Dijk ◽  
Sofie Breuking ◽  
Bryan Vopat ◽  
Daniel Guss ◽  
...  
Keyword(s):  
Surface Area ◽  
Fracture Mechanism ◽  
Soft Tissues ◽  
Plantar Fascia ◽  
Dorsal Side ◽  
Fracture Zones ◽  
Surface Areas ◽  
Metatarsal Bones ◽  
Metatarsal Fractures ◽  
Peroneus Brevis

Category: Midfoot/Forefoot Introduction/Purpose: Proximal fifth metatarsal fractures (PFMF) are among the most common fractures in the foot and can be categorized into three fracture zones [1]. To investigate the fracture mechanism of PFMF in different zones, a better understanding of the anatomy of the bone and its surrounding soft tissues is required. Both the plantar fascia (PF) and the peroneus brevis (PB) tendon insertions are at the base of the fifth metatarsal, and may contribute to the pathophysiology of PFMF. However, the role of the PB and PF insertions in the pathogenesis of PFMF remains unclear. The purpose of this study was to accurately define the footprint of the PB and PF insertions of the base of the 5th metatarsal in relation to the different zones of PFMF. Methods: 21 cadaveric fifth metatarsal bones were harvested from cadaveric feet. All bones were freed of any remaining soft tissue adherence, except for the PB and the PF insertions. Three reference screws with a diameter of 1 mm were placed and secured on each bone with 2 screws distally and 1 screw proximally for registration. All bones were CT scanned to create a 3D bone reconstruction. Next, the insertions of the PB and PF and the reference screws of each bone were digitized and then mapped to its corresponding 3D bone model. In order to describe the three different fracture zones of the 5th metatarsal, an established coordinate system was made for each bone to simulate separate fracture zones (Figure a) based on Lawrence guideline [1]. The shape, location and surface areas of both insertions and their relation to the different fractures zones were determined (Figure b). Results: The insertion of the PB was oval shaped and located on the dorsal side of the base, with a mean surface area of 88.1 ± 46.4 mm2. The PF was oval shaped and situated around the tip of tuberosity, with a mean surface area of 150.7±53.5 mm2. The PB insertion was present in zone 1 fractures in 100% (21/21) of the 5th metatarsal models and 29% (6/21) of the models for zone 2 fractures. The PF insertion was involved in 100% (21/21) of the 5th metatarsal models for zone 1 fractures and 43% (9/21) of the models for zone 2 fractures. Conclusion: Results of this study demonstrate that the insertion of both the PB and PF are involved in all zone 1 PFMF and a significant percentage of zone 2 PFMF. The location of tendon insertions affect the forces exerted on the bone, which may indicate a relation of the insertions of both the PB and the PF with the fracture mechanism of many zone 1 and 2 PFMF. Moreover, in the treatment of these fractures, care should be taken to maintain or restore the anatomy of these insertions to maximize functional outcomes.

The Relation of Vibrator Surface Area and Static Application Force to the Vibrator-to-Head Coupling

1968 ◽  
Vol 11 (4) ◽  
pp. 805-810 ◽  
Author(s):  
E. R. Nilo
Keyword(s):  
Young Adult ◽  
Surface Area ◽  
Unit Area ◽  
Bone Conduction ◽  
Pressure Force ◽  
Adult Men ◽  
Surface Areas ◽  
History Of ◽  
Preliminary Study ◽  
Bone Conduction Hearing

Twelve young adult men with normal hearing and no history of ear disease took part in our study of the relation of vibrator surface area and static application force to the vibrator-to-head coupling. For vibrator surface areas of 1.125, 2.25, and 4.5 cm 2 coupled to the forehead under static forces of 150, 300, and 600 gm, monaural thresholds of bone-conduction hearing were determined at frequencies 250, 500, 1000, and 2000 Hz. With surface area constant, threshold improvement was frequency dependent. It decreased with increasing frequency until at 2000 Hz it was minimal. In contrast to this, with force constant, the influence of surface area was observed to begin at 2000 Hz. Preliminary study suggests this influence would extend to 4000 Hz. In view of the respective influence of application force and surface area to bone-conduction hearing, equating vibrator-to-head coupling on the basis of pressure (force per unit area), when there are two or more vibrators, may not represent an adequate control.

scholarly journals Accurate Measurement of Surface Areas of Anatomical Structures Including Areas with an Irregular Relief: a Modern Solution to the Problem

2021 ◽  
Vol 9 (4) ◽  
pp. 90-95
Author(s):  
A. A. Воробьев ◽  
Yu. A. Makedonova ◽  
A. O. Solov'ev ◽  
D. Yu. D'yachenko ◽  
E. G. Bagrii ◽  
...  
Keyword(s):  
Surface Area ◽  
3D Model ◽  
Maxillofacial Surgery ◽  
Model Reconstruction ◽  
Maxillofacial Region ◽  
Anatomical Structures ◽  
Anatomical Region ◽  
Surface Areas ◽  
3D Model Reconstruction ◽  
Modern Solution

Relevance. The currently available methods for measuring anatomical areas with irregular relief do not claim to be accurate and easy to use.The aim of the study was to develop a method for measuring the surface area of an anatomical region (substructure) with an irregular relief.Material and methods. There was developed an option to measure the surface area of an anatomical region (substructure) with a complex relief in patients with pathology of the maxillofacial region and perineum using realistic 3D modeling.Results. The principle of the developed method is that, firstly, it is necessary to determine the patient's "zone of interest", where it is planned to measure the surface area; after that, digital photographs of the defined area are taken to obtain a sufficient number of images from the maximum number of available angles using a template with predefined dimensions for scaling. Then the obtained photographs are processed in the program for the 3D model reconstruction, and a realistic 3D model that correctly repeats the relief of the "zone of interest" and guarantees measurements of the surface area taking into account all its individual features is obtained. The method has been tested in obstetrics and gynecology, dentistry, maxillofacial surgery.Conclusion. This technique has been proved to be simple, accessible, fast, highly accurate in measuring the area of anatomical regions with complex relief. At the same time, the investigated object does not need fixation and prolonged immobility. A digital optical device is used contactless, the fact being significant in situations where it is necessary to comply with the rules of asepsis and antisepsis.

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