Optical diffusion property of chicken tissue

2004 ◽  
Author(s):  
Patricia S. Schneider ◽  
Alex Flamholz ◽  
Peter K. Wong ◽  
David H. Lieberman ◽  
Tak D. Cheung ◽  
...  
Keyword(s):  
Diffusion Property ◽  
Chicken Tissue

scholarly journals Enhancement of Photoacoustic Signal Strength with Continuous Wave Optical Pre-Illumination: A Non-Invasive Technique

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1190
Author(s):  
Anjali Thomas ◽  
Souradip Paul ◽  
Joy Mitra ◽  
Mayanglambam Suheshkumar Singh
Keyword(s):  
Methylene Blue ◽  
Continuous Wave ◽  
Optical Power ◽  
Signal Strength ◽  
Optical Beam ◽  
Clinical Translation ◽  
Optical Absorption Coefficient ◽  
Invasive Technique ◽  
Light Sources ◽  
Chicken Tissue

Use of portable and affordable pulse light sources (light emitting diodes (LED) and laser diodes) for tissue illumination offers an opportunity to accelerate the clinical translation of photoacoustic imaging (PAI) technology. However, imaging depth in this case is limited because of low output (optical) power of these light sources. In this work, we developed a noninvasive technique for enhancing strength (amplitude) of photoacoustic (PA) signal. This is a photothermal-based technique in which a continuous wave (CW) optical beam, in addition to short-pulse ~ nsec laser beam, is employed to irradiate and, thus, raise the temperature of sample material selectively over a pre-specified region of interest (we call the process as pre-illumination). The increase in temperature, in turn enhances the PA-signal strength. Experiments were conducted in methylene blue, which is one of the commonly used contrast agents in laboratory research studies, to validate change in temperature and subsequent enhancement of PA-signal strength for the following cases: (1) concentration or optical absorption coefficient of sample, (2) optical power of CW-optical beam, and (3) time duration of pre-illumination. A theoretical hypothesis, being validated by numerical simulation, is presented. To validate the proposed technique for clinical and/or pre-clinical applications (diagnosis and treatments of cancer, pressure ulcers, and minimally invasive procedures including vascular access and fetal surgery), experiments were conducted in tissue-mimicking Agar phantom and ex-vivo animal tissue (chicken breast). Results demonstrate that pre-illumination significantly enhances PA-signal strength (up to ~70% (methylene blue), ~48% (Agar phantom), and ~40% (chicken tissue)). The proposed technique addresses one of the primary challenges in the clinical translation of LED-based PAI systems (more specifically, to obtain a detectable PA-signal from deep-seated tissue targets).

scholarly journals Chloride Diffusion Property of Hybrid Basalt–Polypropylene Fibre-Reinforced Concrete in a Chloride–Sulphate Composite Environment under Drying–Wetting Cycles

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1138
Author(s):  
Yang Luo ◽  
Ditao Niu ◽  
Li Su
Keyword(s):  
Reinforced Concrete ◽  
Coupling Effect ◽  
Early Stage ◽  
Polypropylene Fibre ◽  
Chloride Diffusion ◽  
Fibre Reinforcement ◽  
Fibre Reinforced Concrete ◽  
Basalt Fibre ◽  
Diffusion Property ◽  
Chloride Attack

The effect of fibre reinforcement on the chloride diffusion property of concrete is controversial, and the coupling effect of sulphate erosion and drying–wetting cycles in marine environments has been neglected in previous studies. In this study, the chloride diffusion property of hybrid basalt–polypropylene fibre-reinforced concrete subjected to a combined chloride–sulphate solution under drying–wetting cycles was investigated. The effects of basalt fibre (BF), polypropylene fibre (PF), and hybrid BP–PF on the chloride diffusion property were analysed. The results indicate that the presence of sulphate inhibits the diffusion of chloride at the early stage of erosion. However, at the late stage of erosion, sulphate does not only accelerate the diffusion of chloride by causing cracking of the concrete matrix but also leads to a decrease in the alkalinity of the pore solution, which further increases the risk of corrosion of the reinforcing steel. An appropriate amount of fibre can improve the chloride attack resistance of concrete at the early stage. With the increase in erosion time, the fibre effectively prevents the formation and development of sulphate erosion microcracks, thus reducing the adverse effects of sulphate on the resistance of concrete to chloride attack. The effects of sulphate and fibre on the chloride diffusion property were also elucidated in terms of changes in corrosion products, theoretical porosity, and the fibre-matrix interface transition zone.

Octamer and SPH motifs in the U1 enhancer cooperate to activate U1 RNA gene expression

1990 ◽  
Vol 10 (1) ◽  
pp. 341-352
Author(s):  
K A Roebuck ◽  
D P Szeto ◽  
K P Green ◽  
Q N Fan ◽  
W E Stumph
Keyword(s):  
Dna Sequence ◽  
Functional Activity ◽  
Stable Complex ◽  
Small Nuclear Rna ◽  
Base Pairs ◽  
Rna Transcription ◽  
Octamer Motif ◽  
Chicken Tissue ◽  
Nuclear Rna ◽  
Gc Box

The transcriptional enhancer of a chicken U1 small nuclear RNA gene has been shown to extend over approximately 50 base pairs of DNA sequence located 180 to 230 base pairs upstream of the U1 transcription initiation site. It is composed of multiple functional motifs, including a GC box, an octamer motif, and a novel SPH motif. The contributions of these three distinct sequence motifs to enhancer function were studied with an oocyte expression assay. Under noncompetitive conditions in oocytes, the SPH motif is capable of stimulating U1 RNA transcription in the absence of the other functional motifs, whereas the octamer motif by itself lacks this ability. However, to form a transcription complex that is stable to challenge by a second competing small nuclear RNA transcription unit, both the octamer and SPH motifs are required. The GC box, although required for full enhancer activity, is not essential for stable complex formation in oocytes. Site-directed mutagenesis was used to study the DNA sequence requirements of the SPH motif. Functional activity of the SPH motif is spread throughout a 24-base-pair region 3' of the octamer but is particularly dependent upon sequences near an SphI restriction site located at the center of the SPH motif. Using embryonic chicken tissue as a source material, we identified and partially purified a factor, termed SBF, that binds sequence specifically to the SPH motif of the U1 enhancer. The ability of this factor to recognize and bind to mutant enhancer DNA fragments in vitro correlates with the functional activity of the corresponding enhancer sequences in vivo.

Anisotropic Light Diffusion Property of Dentin

2013 ◽  
Vol 40 (2) ◽  
pp. 0204001
Author(s):  
陈庆光 Chen Qingguang ◽  
徐英 Xu Ying ◽  
朱海华 Zhu Haihua ◽  
林斌 Lin Bin ◽  
陈晖 Chen Hui
Keyword(s):  
Diffusion Property ◽  
Light Diffusion

Silicone Rubber: A New Diffusion Property Useful for General Anesthesia

1967 ◽  
Vol 40 (3) ◽  
pp. 928-931 ◽  
Author(s):  
Judah Folkman ◽  
David M. Long ◽  
Richard Rosenbaum
Keyword(s):  
Nitrous Oxide ◽  
General Anesthesia ◽  
Silicone Rubber ◽  
New Method ◽  
Diffusion Property ◽  
Rubber Tubing ◽  
Anesthetic Agents ◽  
Potential Applications

Abstract Ether, nitrous oxide, halothane, and cyclopropane diffuse through silicone rubber. General anesthesia can be produced in dogs by passing the vapors of any of these anesthetic agents through a coil of silicone rubber tubing, each end of which is placed in an artery and vein. Potential applications include a new method for general anesthesia and a simple accurate vaporizer for halothane.

Avidin and ovalbumin induction by progesterone in chicken oviduct detected by sensitive immunoenzymometric assays

1991 ◽  
Vol 130 (2) ◽  
pp. 191-197 ◽  
Author(s):  
T. Joensuu ◽  
P. Tuohimaa ◽  
P. Vilja
Keyword(s):  
Body Weight ◽  
Oestrogen Treatment ◽  
Low Concentrations ◽  
Coefficients Of Variation ◽  
Chicken Tissue ◽  
Chicken Oviduct ◽  
Biotin Binding ◽  
The Mean ◽  
Dose Dependent

ABSTRACT This study describes sensitive immunoenzymometric assays (IEMAs) for chicken avidin and ovalbumin, markers of cytodifferentiation and action of progesterone and oestrogen in the oviduct magnum mucosa. The determination range was 0·5–100 ng/ml and the detection limit 0·1 ng/ml in both IEMAs. The intra- and interassay coefficients of variation, measured from chicken tissue supernatants, averaged below 6 and 10% respectively. IEMAs correlated well with the radioimmunoassays for avidin and ovalbumin previously developed in our laboratory, and with the widely used [14C]biotin-binding method for avidin. Using an IEMA, we found avidin induction with low concentrations of progesterone in the differentiated oviduct of oestrogen-pretreated chicks. The induction has not been detected previously by less sensitive methods. Avidin was induced by all given doses of progesterone (0·2–200 mg/kg in vivo for 24 h after a short oestrogen treatment), the response being dose-dependent at doses of 0·2–20 mg progesterone/kg body weight, the maximum avidin production being about 70 μg/g tissue. Ovalbumin was induced at doses of 2–200 mg progesterone/kg body weight without variations in the responses, being about 35 mg/g. The mean content of avidin in the oviduct of laying hens was 58·1 μg/g, and of ovalbumin 74·9 mg/g. Minimal traces of avidin and ovalbumin were found in the oviduct after hatching (0·3 and 5 μg/g respectively); however, progesterone did not have an effect on this expression. Sensitivity, rapidity and practicability, together with non-radioactivity, are the main advantages of the present IEMAs for chicken avidin and ovalbumin. Journal of Endocrinology (1991) 130, 191–197

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