scholarly journals Shark spiral intestines may operate as Tesla valves

2021 ◽  
Vol 288 (1955) ◽  
pp. 20211359
Author(s):  
Samantha C. Leigh ◽  
Adam P. Summers ◽  
Sarah L. Hoffmann ◽  
Donovan P. German
Keyword(s):  
Computational Models ◽  
Three Dimensional ◽  
Morphological Data ◽  
Spiral Intestine ◽  
Unidirectional Flow ◽  
Technological Advances ◽  
Functional Context ◽  
Tesla Valve ◽  
Anterior Direction ◽  
Diet Type

Looking to nature for inspiration has led to many diverse technological advances. The spiral valve intestine of sharks has provided the opportunity to observe the efficiency of different valve systems. It is supposed that the spiral intestine present in sharks, skates and rays slows the transit rate of digesta through the gut and provides increased surface area for the absorption of nutrients. In this investigation, we use a novel technique—creating three-dimensional reconstructions from CT scans of spiral intestines—to describe the morphology of the spiral intestine of at least one species from 22 different shark families. We discuss the morphological data in an evolutionary, dietary and functional context. The evolutionary analyses suggest that the columnar morphology is the ancestral form of the spiral intestine. Dietary analyses reveal no correlation between diet type and spiral intestine morphology. Flow rate was slowed significantly more when the two funnel-shaped spiral intestines were subjected to flow in the posterior to anterior direction, indicating their success at producing unidirectional flow, similar to a Tesla valve. These data are available to generate additional three-dimensional morphometrics, create computational models of the intestine, as well as to further explore the function of the gastrointestinal tract of sharks in structural and physiological contexts.

Scanning electron microscopy of freeze-fractured prescapular lymph node of caprine

1984 ◽  
Vol 42 ◽  
pp. 244-245
Author(s):  
O. Faroon ◽  
F. Al-Bagdadi ◽  
T. G. Snider ◽  
C. Titkemeyer
Keyword(s):  
Lymph Node ◽  
Lymph Nodes ◽  
Lymphatic System ◽  
Three Dimensional ◽  
Meat Products ◽  
The Body ◽  
Morphological Data ◽  
The World ◽  
Cellular Constituent ◽  
Scanning Electron

The lymphatic system is very important in the immunological activities of the body. Clinicians confirm the diagnosis of infectious diseases by palpating the involved cutaneous lymph node for changes in size, heat, and consistency. Clinical pathologists diagnose systemic diseases through biopsies of superficial lymph nodes. In many parts of the world the goat is considered as an important source of milk and meat products.The lymphatic system has been studied extensively. These studies lack precise information on the natural morphology of the lymph nodes and their vascular and cellular constituent. This is due to using improper technique for such studies. A few studies used the SEM, conducted by cutting the lymph node with a blade. The morphological data collected by this method are artificial and do not reflect the normal three dimensional surface of the examined area of the lymph node. SEM has been used to study the lymph vessels and lymph nodes of different animals. No information on the cutaneous lymph nodes of the goat has ever been collected using the scanning electron microscope.

scholarly journals Macroporous chitosan/methoxypoly(ethylene glycol) based cryosponges with unique morphology for tissue engineering applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pradeep Kumar ◽  
Viness Pillay ◽  
Yahya E. Choonara
Keyword(s):  
Tissue Engineering ◽  
Polymer Network ◽  
Three Dimensional ◽  
Hysteresis Loops ◽  
Interpenetrating Polymer Network ◽  
Morphological Data ◽  
Porous Scaffolds ◽  
Morphological Variations ◽  
Molecular Stability ◽  
The Matrix

AbstractThree-dimensional porous scaffolds are widely employed in tissue engineering and regenerative medicine for their ability to carry bioactives and cells; and for their platform properties to allow for bridging-the-gap within an injured tissue. This study describes the effect of various methoxypolyethylene glycol (mPEG) derivatives (mPEG (-OCH3 functionality), mPEG-aldehyde (mPEG-CHO) and mPEG-acetic acid (mPEG-COOH)) on the morphology and physical properties of chemically crosslinked, semi-interpenetrating polymer network (IPN), chitosan (CHT)/mPEG blend cryosponges. Physicochemical and molecular characterization revealed that the –CHO and –COOH functional groups in mPEG derivatives interacted with the –NH2 functionality of the chitosan chain. The distinguishing feature of the cryosponges was their unique morphological features such as fringe thread-, pebble-, curved quartz crystal-, crystal flower-; and canyon-like structures. The morphological data was well corroborated by the image processing data and physisorption curves corresponding to Type II isotherm with open hysteresis loops. Functionalization of mPEG had no evident influence on the macro-mechanical properties of the cryosponges but increased the matrix strength as determined by the rheomechanical analyses. The cryosponges were able to deliver bioactives (dexamethasone and curcumin) over 10 days, showed varied matrix degradation profiles, and supported neuronal cells on the matrix surface. In addition, in silico simulations confirmed the compatibility and molecular stability of the CHT/mPEG blend compositions. In conclusion, the study confirmed that significant morphological variations may be induced by minimal functionalization and crosslinking of biomaterials.

Foundations of Advanced Neuroanatomy: Technical Guidelines for Specimen Preparation, Dissection, and 3D-Photodocumentation in a Surgical Anatomy Laboratory

2019 ◽  
Author(s):  
Luciano César PC Leonel ◽  
Lucas P. Carlstrom ◽  
Christopher S. Graffeo ◽  
Avital Perry ◽  
Carlos Diogenes Pinheiro-Neto ◽  
...  
Keyword(s):  
Oral Tradition ◽  
Dynamic Range ◽  
Tap Water ◽  
Three Dimensional ◽  
High Dynamic Range ◽  
Surgical Anatomy ◽  
Lessons Learned ◽  
Specimen Preparation ◽  
Technological Advances ◽  
Key Steps

Abstract Objective This study was aimed to provide a key update to the seminal works of Prof. Albert L. Rhoton Jr., MD, with particular attention to previously unpublished insights from the oral tradition of his fellows, recent technological advances including endoscopy, and high-dynamic range (HDR) photodocumentation, and, local improvements in technique, we have developed to optimize efficient neuroanatomic study. Methods Two formaldehyde-fixed cadaveric heads were injected with colored latex to demonstrate step-by-step specimen preparation for microscopic or endoscopic dissection. One formaldehyde-fixed brain was utilized to demonstrate optimal three-dimensional (3D) photodocumentation techniques. Results Key steps of specimen preparation include vessel cannulation and securing, serial tap water flushing, specimen drainage, vessel injection with optimized and color-augmented latex material, and storage in 70% ethanol. Optimizations for photodocumentation included the incorporation of dry black drop cloth and covering materials, an imaging-oriented approach to specimen positioning and illumination, and single-camera stereoscopic capture techniques, emphasizing the three-exposure-times-per-eye approach to generating images for HDR postprocessing. Recommended tools, materials, and technical nuances were emphasized throughout. Relative advantages and limitations of major 3D projection systems were comparatively assessed, with sensitivity to audience size and purpose specific recommendations. Conclusion We describe the first consolidated step-by-step approach to advanced neuroanatomy, including specimen preparation, dissection, and 3D photodocumentation, supplemented by previously unpublished insights from the Rhoton fellowship experience and lessons learned in our laboratories in the past years such that Prof. Rhoton's model can be realized, reproduced, and expanded upon in surgical neuroanatomy laboratories worldwide.

Three Dimensional Video Imaging for Endoscopic Sinus Surgery and Diagnosis

1995 ◽  
Vol 9 (4) ◽  
pp. 197-202 ◽  
Author(s):  
Anthony J. Reino ◽  
William Lawson ◽  
Baxter J. Garcia ◽  
Robert J. Greenstein
Keyword(s):  
Endoscopic Sinus Surgery ◽  
Three Dimensional ◽  
Small Diameter ◽  
Image Distortion ◽  
Sinus Surgery ◽  
Depth Of Field ◽  
Visual Fatigue ◽  
Video Imaging ◽  
Video Cameras ◽  
Technological Advances

Technological advances in video imaging over the last decade have resulted in remarkable additions to the armamentarium of instrumentation for the otolaryngologist. The use of video cameras and computer generated imaging in the operating room and office is invaluable for documentation and teaching purposes. Despite the obvious advantages of these systems, problems are evident, the most serious of which include image distortion and inability to judge depth of field. For more than 6 decades 3D imaging has been neither technically nor commercially successful. Reasons include alignment difficulties and image distortion. The result is “visual fatigue,” usually in about 15 minutes. At its extreme, this may be characterized by headache, nausea, and even vomiting. In this study, we employed the first 3D video imager to electronically manipulate a single video source to produce 3D images; therefore, neither alignment nor image distortions were produced. Of interest to the clinical surgeon, “visual fatigue” does not seem to occur; however, with prolonged procedures (greater than 2 hours) there exists the potential for physical intolerance for some individuals. This is the first unit that is compatible with any rigid or flexible videoendoscopic system and the small diameter endoscopes available for endoscopic sinus surgery. Moreover, prerecorded 2D tapes may be viewed in 3D on an existing VCR. The 3D image seems to provide enhanced anatomic awareness with less image distortion. We have found this system to be optically superior to the 2D video imagers currently available.

An efficient approach to converting three-dimensional image data into highly accurate computational models

2008 ◽  
Vol 366 (1878) ◽  
pp. 3155-3173 ◽  
Author(s):  
P.G Young ◽  
T.B.H Beresford-West ◽  
S.R.L Coward ◽  
B Notarberardino ◽  
B Walker ◽  
...  
Keyword(s):  
Mesh Generation ◽  
Computational Models ◽  
Three Dimensional ◽  
Image Data ◽  
Model Material ◽  
Imaging Data ◽  
Material Inhomogeneity ◽  
Dimensional Image ◽  
Wide Range ◽  
Impact Modelling

Image-based meshing is opening up exciting new possibilities for the application of computational continuum mechanics methods (finite-element and computational fluid dynamics) to a wide range of biomechanical and biomedical problems that were previously intractable owing to the difficulty in obtaining suitably realistic models. Innovative surface and volume mesh generation techniques have recently been developed, which convert three-dimensional imaging data, as obtained from magnetic resonance imaging, computed tomography, micro-CT and ultrasound, for example, directly into meshes suitable for use in physics-based simulations. These techniques have several key advantages, including the ability to robustly generate meshes for topologies of arbitrary complexity (such as bioscaffolds or composite micro-architectures) and with any number of constituent materials (multi-part modelling), providing meshes in which the geometric accuracy of mesh domains is only dependent on the image accuracy (image-based accuracy) and the ability for certain problems to model material inhomogeneity by assigning the properties based on image signal strength. Commonly used mesh generation techniques will be compared with the proposed enhanced volumetric marching cubes (EVoMaCs) approach and some issues specific to simulations based on three-dimensional image data will be discussed. A number of case studies will be presented to illustrate how these techniques can be used effectively across a wide range of problems from characterization of micro-scaffolds through to head impact modelling.

scholarly journals 3D Laparoscopic Monitors

2014 ◽  
Vol 5 ◽  
pp. MEI.S13342
Author(s):  
Francesca Destro ◽  
Noemi Cantone ◽  
Mario Lima
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Invasive Surgery ◽  
Three Dimensional ◽  
Short Paper ◽  
High Definition ◽  
Recent Introduction ◽  
Technological Advances ◽  
New Surgery

Minimally invasive surgery (MIS) is a relatively new surgery comprising various procedures performed with special miniaturized instruments and imaging reproduction systems. Technological advances have made MIS an efficient, safe, and applicable tool for pediatric surgeons with unquestionable advantages. The recent introduction of three-dimensional (3D) high definition systems has been advocated in order to overcome some of the problems related to standard MIS visual limitations. This short paper recapitulates the necessity to minimize MIS visualization limitations and reports the characteristics of new laparoscopic 3D systems.

scholarly journals Tooth-size discrepancy: A comparison between manual and digital methods

2014 ◽  
Vol 19 (4) ◽  
pp. 107-113 ◽  
Author(s):  
Gabriele Dória Cabral Correia ◽  
Fernando Antonio Lima Habib ◽  
Carlos Jorge Vogel
Keyword(s):  
Three Dimensional ◽  
Diagnostic Tools ◽  
Tooth Size ◽  
Digital Models ◽  
Linear Measurements ◽  
Length Discrepancy ◽  
Technological Advances ◽  
Size Discrepancy ◽  
Digital Methods ◽  
Plaster Models

INTRODUCTION: Technological advances in Dentistry have emerged primarily in the area of diagnostic tools. One example is the 3D scanner, which can transform plaster models into three-dimensional digital models. OBJECTIVE: This study aimed to assess the reliability of tooth size-arch length discrepancy analysis measurements performed on three-dimensional digital models, and compare these measurements with those obtained from plaster models. MATERIAL AND METHODS: To this end, plaster models of lower dental arches and their corresponding three-dimensional digital models acquired with a 3Shape R700T scanner were used. All of them had lower permanent dentition. Four different tooth size-arch length discrepancy calculations were performed on each model, two of which by manual methods using calipers and brass wire, and two by digital methods using linear measurements and parabolas. RESULTS: Data were statistically assessed using Friedman test and no statistically significant differences were found between the two methods (P > 0.05), except for values found by the linear digital method which revealed a slight, non-significant statistical difference. CONCLUSIONS: Based on the results, it is reasonable to assert that any of these resources used by orthodontists to clinically assess tooth size-arch length discrepancy can be considered reliable.

scholarly journals Cone-Beam Three-Dimensional Dental Volumetric Tomography in Dental Practice

2017 ◽  
Vol 7 (3) ◽  
pp. 62 ◽  
Author(s):  
Suzan Cangul ◽  
Ozkan Adiguzel
Keyword(s):  
Soft Tissues ◽  
Low Cost ◽  
Three Dimensional ◽  
Cone Beam ◽  
Imaging Method ◽  
Dental Practice ◽  
3 Dimensional ◽  
Scanning Time ◽  
Technological Advances ◽  
Native Speakers Of English

Imaging methods are of great importance for diagnosis and treatment in dentistry. With technological advances, great progress has been made in these methods. Over time, 3-dimensional (3-D) imaging has replaced 2-dimensional, thereby providing examination of objects in all directions. Of these methods, which play an important role in the clinical evaluation of patients, cone-beam computed tomography (CBCT) is the newest and most advanced imaging method. This method will revolutionize dental in comparison with conventional CT, it has several advantages, including a shorter scanning time, low radiation dose, low cost and the acquisition of high-resolution images. With 3-D imaging technology, this method has introduced the possibility of applying several procedures from diagnosis in the maxillofacial region to operative and surgical procedures. Although very clear results are not obtained from the imaging of soft tissues, the most important advantage of this technology is the capability of imaging hard and soft tissues together.   How to cite this article: Cangul S, Adiguzel O. Cone-Beam Three-Dimensional Dental Volumetric Tomography in Dental Practice. Int Dent Res 2017;7:62-70.  Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Two rhombomeres are altered in Hoxa-1 mutant mice

Development ◽  
1993 ◽  
Vol 119 (2) ◽  
pp. 319-338 ◽  
Author(s):  
M. Mark ◽  
T. Lufkin ◽  
J.L. Vonesch ◽  
E. Ruberte ◽  
J.C. Olivo ◽  
...  
Keyword(s):  
Neural Crest ◽  
Motor Neurons ◽  
Cranial Nerves ◽  
Three Dimensional ◽  
Neural Crest Cell ◽  
Mutant Mice ◽  
Morphological Data ◽  
Vagus Nerves ◽  
Membranous Labyrinth ◽  
Free Region

This study provides a detailed description of the anatomical defects in the Hoxa-1−/− mutant mice previously generated in our laboratory (T. Lufkin, A. Dierich, M. LeMeur, M. Mark and P. Chambon, 1991; Cell 66, 1105–1119). Three-dimensional reconstructions of the Hoxa-1−/− rhombencephalon reveals that it bears only five rhombomeric structures (ie. morphological segments) instead of the normal seven. The first three of these rhombomeres appear normal as judged from the distribution pattern of CRABPI transcripts in the neurectoderm and from the histological analysis of the cranial nerve components derived from these structures. In contrast, the neural-crest-cell-free region normally located opposite rhombomere 5 is lacking in Hoxa-1−/− embryos, and motor neurons of the facial and abducens nerves, which normally differentiate within rhombomeres 4, 5 and 6, are missing in Hoxa-1−/− fetuses. These morphological data, combined with the determination of the molecular positional identities of the rhombomeres 4 and 5 (P. Dolle, T. Lufkin, R. Krumlauf, M. Mark, D. Duboule and P. Chambon, 1993; Proc. Natl. Acad. Sci. USA, in press), suggest that rhombomere 4 is markedly reduced, whereas rhombomere 5 is almost absent. Thus, the remnants of rhombomeres 4 and 5 appear to be fused caudally with rhombomere 6 to form a single fourth rhombomeric structure. Moreover, the migration of neural crest cells contributing to the glossopharyngeal and vagus nerves occurs in a more rostral position, resulting in abnormalities of these cranial nerves, which were visualized by whole-mount anti-neurofilament immunostaining. The mutual relationship along the rostrocaudal axis between the otic pit and the neuroepithelial site of int-2 protein secretion (a putative otogenic cue) is not significantly changed in Hoxa-1−/− embryos. However, the abnormal relationship between the rhombencephalon and the epithelial inner ear may account for the aplasia and faulty differentiation of the membranous labyrinth, the disruption of the cartilaginous otic capsule and the disorganisation of some middle ear structures. This phenotype is compared with that of the Hoxa-1−/− mutants generated by O. Chisaka, T. S. Musci and M. R. Capecchi, 1992 (Nature 335, 516–520) and with that of the mice homozygous for the kreisler mutation.

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