scholarly journals Morphological Transformation between Flat and Tube Structures by Coordinated Motions of Soft Pneumatic Microactuators

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Satoshi Konishi ◽  
Fumitaka Oya
Keyword(s):  
Small Intestine ◽  
Biomedical Applications ◽  
Intestinal Tract ◽  
Three Dimensional ◽  
Higher Order ◽  
Peristaltic Motion ◽  
Morphological Transformation ◽  
Small Intestinal ◽  
Higher Order Functions ◽  
Tube Structure

Abstract Microactuators are the most distinctive and challenging microdevices among micro electromechanical systems (MEMS) relative to microsensors or electronic circuits. Soft and flexible microactuators have been achieved by introducing polymers as structural materials in addition to conventional materials. Expanding the application of MEMS to the biomedical field requires particular features, such as softness and small devices. It is important to address small and fragile biological objects while satisfying the demand for minimally invasive medicine. Both MEMS and biomedical applications require three-dimensional microstructures for higher-order functions. In general, microactuators are limited to simple motions such as bending. Our group has developed an openable artificial small intestinal tract system. An array of pneumatic balloon actuators (PBAs) transforms a flat structure into a tube structure representing the small intestine. Coordination of the bending motions of the PBAs enables the formation of a three-dimensional tube structure. Each PBA is 400 μm × 1800 μm × 100 μm. The diameter of the tube structure is 1 mm. Additional higher-order functions of the artificial small intestine, such as peristaltic motion, are currently of interest for us. This paper describes the morphological transformation of a soft microstructure and further potential possibilities of coordinated motions of soft microactuators.

scholarly journals Phosphopeptides and soluble calcium in the small intestine of rats given a casein diet

1980 ◽  
Vol 43 (3) ◽  
pp. 457-467 ◽  
Author(s):  
Yeon Sook Lee ◽  
T. Noguchi ◽  
H. Naito
Keyword(s):  
Small Intestine ◽  
Amino Acid ◽  
Intestinal Tract ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Casein Diet ◽  
Egg Albumin ◽  
Intestinal Contents ◽  
Soluble Calcium ◽  
Small Intestinal

1. Semi-synthetic diets containing 200 g protein/kg were meal-fed for 1.5 h to groups of rats. The contents of the whole small intestinal tract were collected and the amount of soluble calcium was determined.2. In the rats given 200 g casein/kg diet, formation of a fraction containing macrophosphopeptide in the small intestine was confirmed by gelfiltration of the intestinal contents on Sephadex G-25. However, this macrophosphopeptide fraction was not found when casein alone was fed.3. In the intestinal contents at 2.5 h after ingestion, the amounts of both soluble Ca and phosphorus were significantly higher in rats fed the casein diet than in those fed diets containing egg albumin, isolated soyabean protein or an amino acid mixture. However, the amount of insoluble Ca was least in rats fed the casein diet.

scholarly journals Microfluidic Device Using Mouse Small Intestinal Tissue for the Observation of Fluidic Behavior in the Lumen

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 692
Author(s):  
Satoru Kuriu ◽  
Naoyuki Yamamoto ◽  
Tadashi Ishida
Keyword(s):  
Small Intestine ◽  
Fluid Flow ◽  
Flow Field ◽  
Immune Responses ◽  
Microfluidic Device ◽  
Intestinal Tract ◽  
Gut Bacteria ◽  
Intestinal Tissue ◽  
Histological Techniques ◽  
Small Intestinal

The small intestine has the majority of a host’s immune cells, and it controls immune responses. Immune responses are induced by a gut bacteria sampling process in the small intestine. The mechanism of immune responses in the small intestine is studied by genomic or histological techniques after in vivo experiments. While the distribution of gut bacteria, which can be decided by the fluid flow field in the small intestinal tract, is important for immune responses, the fluid flow field has not been studied due to limits in experimental methods. Here, we propose a microfluidic device with chemically fixed small intestinal tissue as a channel. A fluid flow field in the small intestinal tract with villi was observed and analyzed by particle image velocimetry. After the experiment, the distribution of microparticles on the small intestinal tissue was histologically analyzed. The result suggests that the fluid flow field supports the settlement of microparticles on the villi.

A Higher-Order Theory for Plane Stress Conditions of Laminates Consisting of Isotropic Layers

1999 ◽  
Vol 66 (1) ◽  
pp. 95-100 ◽  
Author(s):  
X. J. Wu ◽  
S. M. Cheng
Keyword(s):  
Three Dimensional ◽  
Order Theory ◽  
Higher Order ◽  
Shear Stresses ◽  
Stress Equilibrium ◽  
Material Discontinuities ◽  
Interlaminar Shear ◽  
Higher Order Theory ◽  
Three Dimensional Elasticity ◽  
Higher Order Functions

In this paper, a higher-order theory is derived for laminates consisting of isotropic layers, on the basis of three-dimensional elasticity with displacements as higher-order functions of z in the thickness direction. The theory employs three stress potentials, Ψ (an Airy function), p (a harmonic function), and its conjugate q, to satisfy all conditions of stress equilibrium and compatibility. Interlaminar shear stresses, i.e., antiplane stresses, are shown to be present at the interfaces, especially near material discontinuities where gradients of in-plane stresses are usually high. For illustrating its practical application, the problem of a plate containing a hole patched with an intact plate is solved.

scholarly journals Presence and Germination of the Probiotic Bacillus subtilis DE111® in the Human Small Intestinal Tract: A Randomized, Crossover, Double-Blind, and Placebo-Controlled Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Joan Colom ◽  
Daniela Freitas ◽  
Annie Simon ◽  
Andre Brodkorb ◽  
Martin Buckley ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Small Intestine ◽  
Intestinal Tract ◽  
Probiotic Strain ◽  
Dry Weight ◽  
Controlled Study ◽  
Double Blind ◽  
Vegetative Cells ◽  
Final Time Point ◽  
Small Intestinal

Spore-based probiotics offer important advantages over other probiotics as they can survive the harsh gastric conditions of the stomach and bile salts in the small intestine, ultimately germinating in the digestive tract. A novel clinical trial in 11 ileostomy participants was conducted to directly investigate the presence and germination of the probiotic strain Bacillus subtilis DE111® in the small intestine. Three hours following ingestion of DE111®, B. subtilis spores (6.4 × 104 ± 1.3 × 105 CFU/g effluent dry weight) and vegetative cells (4.7 × 104 ± 1.1 × 105 CFU/g effluent dry weight) began to appear in the ileum effluent. Six hours after ingestion, spore concentration increased to 9.7 × 107 ± 8.1 × 107 CFU/g and remained constant to the final time point of 8 h. Vegetative cells reached a concentration of 7.3 × 107 ± 1.4 × 108 CFU/g at 7 h following ingestion. These results reveal orally ingested B. subtilis DE111® spores are able to remain viable during transit through the stomach and germinate in the small intestine of humans within 3 h of ingestion.

Applications of Scanning Microscopy in Biomedical Research

1968 ◽  
Vol 26 ◽  
pp. 354-355
Author(s):  
T. L. Hayes
Keyword(s):  
Information Content ◽  
Biomedical Research ◽  
Biomedical Applications ◽  
Three Dimensional ◽  
Dental Enamel ◽  
Resolving Power ◽  
Whole Mount ◽  
Two Parameters ◽  
Content Information ◽  
Sectioned Tissue

Biomedical applications of the scanning electron microscope (SEM) have increased in number quite rapidly over the last several years. Studies have been made of cells, whole mount tissue, sectioned tissue, particles, human chromosomes, microorganisms, dental enamel and skeletal material. Many of the advantages of using this instrument for such investigations come from its ability to produce images that are high in information content. Information about the chemical make-up of the specimen, its electrical properties and its three dimensional architecture all may be represented in such images. Since the biological system is distinctive in its chemistry and often spatially scaled to the resolving power of the SEM, these images are particularly useful in biomedical research.In any form of microscopy there are two parameters that together determine the usefulness of the image. One parameter is the size of the volume being studied or resolving power of the instrument and the other is the amount of information about this volume that is displayed in the image. Both parameters are important in describing the performance of a microscope. The light microscope image, for example, is rich in information content (chemical, spatial, living specimen, etc.) but is very limited in resolving power.

scholarly journals Comparative Study of Silk Fibroin-Based Hydrogels and Their Potential as Material for 3-Dimensional (3D) Printing

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3887
Author(s):  
Watcharapong Pudkon ◽  
Chavee Laomeephol ◽  
Siriporn Damrongsakkul ◽  
Sorada Kanokpanont ◽  
Juthamas Ratanavaraporn
Keyword(s):  
3D Printing ◽  
Silk Fibroin ◽  
Biomedical Applications ◽  
Mechanical Stability ◽  
Three Dimensional ◽  
Structure Stability ◽  
3 Dimensional ◽  
Critical Technology ◽  
Box Structure ◽  
High Degree

Three-dimensional (3D) printing is regarded as a critical technology in material engineering for biomedical applications. From a previous report, silk fibroin (SF) has been used as a biomaterial for tissue engineering due to its biocompatibility, biodegradability, non-toxicity and robust mechanical properties which provide a potential as material for 3D-printing. In this study, SF-based hydrogels with different formulations and SF concentrations (1–3%wt) were prepared by natural gelation (SF/self-gelled), sodium tetradecyl sulfate-induced (SF/STS) and dimyristoyl glycerophosphorylglycerol-induced (SF/DMPG). From the results, 2%wt SF-based (2SF) hydrogels showed suitable properties for extrusion, such as storage modulus, shear-thinning behavior and degree of structure recovery. The 4-layer box structure of all 2SF-based hydrogel formulations could be printed without structural collapse. In addition, the mechanical stability of printed structures after three-step post-treatment was investigated. The printed structure of 2SF/STS and 2SF/DMPG hydrogels exhibited high stability with high degree of structure recovery as 70.4% and 53.7%, respectively, compared to 2SF/self-gelled construct as 38.9%. The 2SF/STS and 2SF/DMPG hydrogels showed a great potential to use as material for 3D-printing due to its rheological properties, printability and structure stability.

Application of a dynamic mechanistic model of small intestinal starch digestion in the dairy cow

2002 ◽  
Vol 2002 ◽  
pp. 104-104
Author(s):  
J. A. N. Mills ◽  
E. Kebreab ◽  
L. A. Crompton ◽  
J. Dijkstra ◽  
J. France
Keyword(s):  
Experimental Data ◽  
Small Intestine ◽  
Dairy Cow ◽  
Energy Recovery ◽  
Mechanistic Model ◽  
Biological Knowledge ◽  
Dietary Energy ◽  
Starch Digestion ◽  
High Contribution ◽  
Small Intestinal

The high contribution of postruminal starch digestion (>50%) to total tract starch digestion on certain energy dense diets (Mills et al. 1999) demands that limitations to small intestinal starch digestion are identified. Therefore, a dynamic mechanistic model of the small intestine was constructed and evaluated against published experimental data for abomasal carbohydrate infusions in the dairy cow. The mechanistic structure of the model allowed the current biological knowledge to be integrated into a system capable of identifying restrictions to dietary energy recovery from postruminal starch delivery.

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