Choosing the Optimal Tissue Expander Size: A Single Center Randomized Clinical Trial on Chinese Microtia Patients’ Normal Ears Using 3D Scanning

2022 ◽  
Author(s):  
Hefeng Sun ◽  
Pengfei Sun ◽  
Haiyue Jiang ◽  
Qinghua Yang ◽  
Tongtong Li ◽  
...  
Keyword(s):  
Surface Area ◽  
Tissue Expander ◽  
Tissue Expansion ◽  
3D Scanning ◽  
Chinese Patients ◽  
Single Center ◽  
Scatter Plot ◽  
Surface Areas ◽  
Expansion Technique ◽  
Length Width

Abstract The tissue expansion technique is the most suitable procedure for Chinese patients with microtia. However, it is difficult to determine whether the expanded flap is sufficient, and there are no clear or objective guidelines for determining the volume of the expander for different sizes of auricles. One hundred patients with unilateral microtia who visited our department in 2021 were randomly selected for auricular data collection using 3D scanning. The auricle length, width, projection, perimeter, and surface area were measured. Eight different volumes of expanders underwent CT and the surface areas of these expanders were measured. The surface areas of the auricles and expanders were compared and the correlation between them was explored. The average auricle parameters were calculated. The scatter plot showed a linear relationship between auricle length and auricle surface area (R2 = 0.9913), which demonstrated that the auricle area was approximately equal to the auricle length multiplied by 76.921. Additionally, the surface area of the expanders was measured and made into a table for selection against the surface area of the auricles. Using our equation, the auricle surface could be estimated by simply measuring the non-defective auricle length; therefore, the suitable volume of the expander could be determined.

scholarly journals Numerical Modeling of the Shape of Agricultural Products on the Example of Cucumber Fruits

2019 ◽  
Vol 11 (10) ◽  
pp. 2798 ◽  
Author(s):  
Andrzej Anders ◽  
Dariusz Choszcz ◽  
Piotr Markowski ◽  
Adam Józef Lipiński ◽  
Zdzisław Kaliniewicz ◽  
...  
Keyword(s):  
Surface Area ◽  
Numerical Models ◽  
3D Scanning ◽  
Agricultural Products ◽  
Model Combining ◽  
Mathematical Formulas ◽  
Electronic Caliper ◽  
Length Width ◽  
Different Diameters ◽  
Area And Volume

The aim of the study was to build numerical models of cucumbers cv. Śremski with the use of a 3D scanner and to analyze selected geometric parameters of cucumber fruits based on the developed models. The basic dimensions of cucumber fruits–length, width and thickness—were measured with an electronic caliper with an accuracy of d = 0.01 mm, and the surface area and volume of fruits were determined by 3D scanning. Cucumber fruits were scanned with an accuracy of d = 0.13 mm. Six models approximating the shape of cucumber fruits were developed with the use of six geometric figures and their combinations to calculate the surface area and volume of the analyzed agricultural products were identified. The surface area and volume of cucumber fruits calculated by 3D scanning and mathematical formulas were compared. The surface area calculated with the model combining two truncated cones and two hemispheres with different diameters, joined base-to-base, was characterized by the smallest relative error of 3%. Fruit volume should be determined with the use of mathematical formulas derived for a model composed of an ellipsoid and a spheroid. The proposed geometric models can be used in research and design.

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.

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 Repair Exposure of the Postauricular Tissue Expander Using the Modified Brent Method: A 7-Year Experience

2021 ◽  
pp. 014556132110079
Author(s):  
Tongyu Cao ◽  
Qingguo Zhang
Keyword(s):  
Soft Tissue ◽  
Skin Flap ◽  
Tissue Expander ◽  
Tissue Expansion ◽  
Ear Reconstruction ◽  
Lower Pole ◽  
Tension Free ◽  
Subsequent Exposure ◽  
Free Closure ◽  
Complicated Conditions

Objectives: Ear reconstruction is a challenging surgery for the complicated conditions in patients with microtia. The tissue expansion techniques were necessary and relatively safe for patients with insufficient soft tissue. However, complications such as necrosis of expanded flap and exposure of tissue expander limited the popularization of this method. This study described the use of modified Brent method to handle the exposure of the postauricular tissue expander. Methods: From January 2013 to December 2019, 27 ear reconstruction patients with trauma or necrosis on an expanded skin flap and subsequent exposure of tissue expander were treated with modified Brent method, which consisted of 3 stages: removal of the expander, tension-free closure of wound, and framework fabrication; elevation of reconstructed ear; lobule rotation; and minor modification. Results: Fifty-six percent of exposures occurred in the lower pole of the tissue expander. Exposure usually occurred 54.5 days after implantation. The majority of reconstructed ears had a satisfactory appearance and showed relatively stable outcomes. Only one case of cartilage exposure required revision surgery and was repaired by the temporoparietal fascia. Conclusion: With reasonable distribution of expanded flap, prolonged interval, and sutures under tension-free conditions, complications like the occurrence of trauma or necrosis-induced exposure of tissue expander can be repaired efficiently by a staging modified Brent method.

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.

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