Determination of optical properties of normal and adenomatous human colon tissues in vitro using integrating sphere techniques

AIM: The purpose of the present study is to compare the optical properties of normal human colon mucosa/submucosa and muscle layer/chorion, and adenomatous human colon mucosa/submucosa and muscle layer/chorion in vitro at 476.5, 488, 496.5, 514.5 and 532 nm. We believe these differences in optical properties should help differential diagnosis of human colon tissues by using optical methods.METHODS: In vitro optical properties were investigated for four kinds of tissues: normal human colon mucosa/submucosa and muscle layer/chorion, and adenomatous human colon mucosa/submucosa and muscle layer/chorion. Tissue samples were taken from 13 human colons (13 adenomatous, 13 normal). From the normal human colons a total of 26 tissue samples, with a mean thickness of 0.40 mm, were used (13 from mucosa/submucosa and 13 from muscle layer/chorion), and from the adenomatous human bladders a total of 26 tissue samples, with a mean thickness of 0.40 mm, were used (13 from mucosa/submucosa and 13 from muscle layer/chorion). The measurements were performed using a double-integratingsphere setup and the optical properties were assessed from these measurements using the adding-doubling method that was considered reliable.RESULTS: The results of measurement showed that there were significant differences in the absorption coefficients and scattering coefficients between normal and adenomatous human colon mucosa/submucosa at the same wavelength,and there were also significant differences in the two optical parameters between both colon muscle layer/chorion at the same wavelength. And there were large differences in the anisotropy factors between both colon mucosa/submucosa at the same wavelength, there were also large differences in the anisotropy factors between both colon muscle layer/chorion at the same wavelength.There were large differences in the value ranges of the absorption coefficients, scattering coefficients and anisotropy factors between both colon mucosa/submucosa,and there were also large differences in these value ranges between both colon muscle layer/chorion. There are the same orders of magnitude in the absorption coefficients for four kinds of colon tissues. The scattering coefficients of these tissues exceed the absorption coefficients by at least two orders of magnitude.CONCLUSION: There were large differences in the three optical parameters between normal and adenomatous human colon mucosa/submucosa at the same laser wavelength, and there were also large differences in these parameters between both colon muscle layer/chorion at the same laser wavelength. Large differences in optical parameters indicate that there were large differences in compositions and structures between both colon mucosa/submucosa, and between both colon muscle layer/chorion.Optical parameters for four kinds of colon tissues are wavelength dependent, and these differences would be useful and helpful in clinical applications of laser and tumors photodynamic therapy (PDT).

Calibration chain design based on integrating sphere transfer radiometer for SI-traceable on-orbit spectral radiometric calibration and its uncertainty analysis

In order to satisfy the requirement of SI-traceable on-orbit absolute radiation calibration transfer with high accuracy for satellite remote sensors,a transfer chain consisting of a fiber coupling monochromator（FBM） and an integrating sphere transfer radiometer（ISTR） was designed in this paper.Depending on the Sun,this chain based on detectors provides precise spectral radiometric calibration and measurement to spectrometers in the reflective solar band（RSB） covering 300–2500 nm with a spectral bandwidth of 0.5–6 nm.It shortens the traditional chain based on lamp source and reduces the calibration uncertainty from 5% to 0.5% by using the cryogenic radiometer in space as a radiometric benchmark and trap detectors as secondary standard.This paper also gives a detailed uncertainty budget with reasonable distribution of each impact factor,including the weak spectral signal measurement with uncertainty of 0.28%.According to the peculiar design and comprehensive uncertainty analysis,it illustrates that the spectral radiance measurement uncertainty of the ISTR system can reach to 0.48%.The result satisfies the requirements of SI-traceable on-orbit calibration and has wider significance for expanding the application of the remote sensing data with high-quality.

Dick Effect in the Integrating Sphere Cold Atom Clock

The Dick effect is an important factor limiting the frequency stability of sequentially-operating atomic frequency standards. Here we study the impact of the Dick effect in the integrating sphere cold atom clock （ISCAC）. To reduce the impact of the Dick effect, a 5 MHz local oscillator with ultra-low phase noise is selected and a new microwave synthesizer is built in-house. Consequently, the phase noise of microwave signal is optimized. The contribution of the Dick effect is reduced to 2.5× 10^-13τ-1/2 （3- is the integrating time）. The frequency stability of 4.6 × 10-13τ-1/2 is achieved. The development of this optimization can promote the space applications of the compact ISCA C.

Interrelations With Forms of Corruption in the Political Sphere and Its Causal Conditions in Mongolia (the Final Part)

Corruption,which is a serious problem for us today,covers a wide range of social and political phenomena and processes,from the normal functioning of ordinary citizens to the forms and structures of political governance.In particular,the personality is determined by the way of life,the environment,and the needs of the family and social group,and then a political ideology is formed based on the multifaceted interests of social groups,which are expressed in complex social,economic,and political forms.Indicators of the extent to which social well-being is achieved in developing democracies raise questions about whether citizens are united in their views and actions,as well as how they participate and are interested in social and political activities.On the other hand,this is reflected in the differences in views and the level of trust in the government and other social institutions,and as an important tool for determining the development of the country.It is necessary to determine the level of social and political participation.This is the root cause of the problem.Because every democracy is very different,to understand how they affect human development,and to be a social person,people need to be able to provide a little economic security and an understanding of the issues at stake.This is the basis for building a transparent society based on the principles of zero tolerance for corruption,justice,equal participation,and equality.That is why in this subsection we explore the relationships between political parties,groups,political,business,and criminal groups in the form of political corruption,as well as the causes of political corruption in the political sphere.

DEVELOPMENT AND PRELIMINARY APPLICATION OF OBJECTIFYING SYSTEM FOR TCM COLOR INSPECTION

An objectifying system for color inspections of traditional Chinese medicine （CITCM） is developed. The entire system includes two parts ： The hardware and the software. The hardware is an image acquiring device under a standard lighting condition, and it mainly includes a xenon lamp with color temperature of 5 500 K as light source, an integrating sphere used for diffusing light and a high resolution CCD camera. The software is used for digital image processing, and the procedure is divided into three steps. Firstly the skin/non-skin classifi- cation is performed by utilizing the threshold in chrominance channels of the RGB color space. Secondly, the fa- cial features are localized by using the image segmentation and coordinates sorting. Finally, the facial special re- gion（SR） corresponding to five internal organs is achieved by utilizing masks designed to take advantage of mor- phology. Subsequently, the chromaticity is calculated. The system is tested by taking 83 samples of 30 young and 53 elderly people. The experiment shows that there is significant difference of all SRs between the young and the elderly, and the system has better performance for objectifying research of CITCM.

Different Optical Properties between Human Hepatocellular Carcinoma Tissues and Non-tumorous Hepatic Tissues In Vitro

There has been an ongoing search for clinically acceptable methods for the accurate,efficient and simple diagnosis and prognosis of hepatocellular carcinoma（HCC）.Optical spectroscopy is a technique with potential clinical applications to diagnose cancer diseases.The purpose of this study was to obtain the optical properties of HCC tissues and non-tumorous hepatic tissues and identify the difference between them.A total of 55 tissue samples（HCC tissue,n=38;non-tumorous hepatic tissue,n=17） were surgically resected from patients with HCC.The optical parameters were measured in 10-nm steps using single-integrating-sphere system in the wavelength range of 400 to 1800 nm.It was found that the optical properties and their differences varied with the wavelength for the HCC tissue and the non-tumorous hepatic tissue in the entire wavelength range of research.The absorption coefficient of the HCC tissue（1.48±0.99,1.46±0.88,0.86±0.61,2.15±0.53,0.54±0.10,0.79±0.15 mm-1） was significantly lower than that of the non-tumorous hepatic tissue（2.79±1.73,3.13±1.47,3.06±2.79,2.57±0.55,0.62±0.10,0.93±0.16 mm-1） at wavelengths of 400,410,450,1450,1660 and 1800 nm,respectively（P0.05）.The reduced scattering coefficient of HCC tissue（5.28±1.70,4.91±1.54,1.26±0.35 mm-1） and non-tumorous hepatic tissue（8.14±3.70,9.27±3.08,2.55±0.57 mm-1） was significantly different at 460,500 and 1800 nm respectively（P0.05）.These results show different pathologic liver tissues have different optical properties.It provides a better understanding of the relationship between optical parameters and physiological characteristics in human liver tissues.And it would be very useful for developing a non-invasive,real-time,simple and efficient way for medical management of HCC in the future.

Laser speckle contrast imaging for monitoring of acutepancreatitis at ischemia-reperfusion injury of thepancreas in rats

The influence of ischemia-reperfusion(I/R)action on pancreatic blood flow(PBF)and the development of acute pancreatitis(AP)in laboratory rats is evaluated in vivo by using the laser speckle contrast imaging(LSCI).Additionally,the optical properties in norm and under condition of AP in rats were assessed using a modied integrating sphere spectrometer and inverse Monte Carlo(IMC)software.The results of the experimental study of microcirculation of the pancreas in 82 rats in the ischemic model are presented.The data obtained conrm the fact that local ischemia and changes in the blood°ow velocity of the main vessels cause and provoke acute pancreatitis.

A SIMPLE METHOD FOR PREDICTION OF THE REDUCED SCATTERING COEFFICIENT IN TISSUE-SIMULATING PHANTOMS

This paper proposes a method for predicting the reduced scattering coefficients of tissuesimulating phantoms or the desired amount of scatters for producing phantoms according to Mie scattering theory without measurements with other instruments.The concentration of the scatters TiO2 particles is determined according to Mie theory calculation and added to transparent host epoxy resin to produce phantoms with different reduced scattering coefficients.Black India Ink is added to alter the absorption coefficients of the phantoms.The reduced scattering coefficients of phantoms are measured with single integrating sphere system.The results show that the measurements are in direct proportion to the concentration of TiO2 and have identical with Mie theory calculation at multiple wavelengths.The method proposed can accurately determine the concentration of scatters in the phantoms to ensure the phantoms are qualified with desired reduced scattering coefficients at specified wavelength.This investigation should be possible to manufacture the phantom simply in reasonably accurate for evaluation of biomedical optical imaging systems.

Recalibration of working standard lamps

In the present work, recalibration of the National Institute for Standards （NIS, Egypt） working standard lamps from Osram Inc. and their associated expanded uncertainty budget were done. A set-up composed of an integrating sphere, a standard photometer and a group of five luminous flux standard lamps ranged from 25 to 200 W calibrated and traceable to the National Physical Laboratory （NPL, UK） is used to measure and recalibrate the total luminous flux for these five working standard lamps. After recalibration, NIS （Egypt） maintains the national scales for luminous flux in lumen.

A Dialectic Analysis of the Concept of Ecological Civilization

Ecological civilization has already evolved into a complex conceptual system. The mainstream idea holds that ecological civilization is an element of civilization, or a whole new social form, while other ideas view it as a philosophy of green development, a measure of green orientation, an outcome of the overall development of civilization. This paper, however, maintains that ecological civilization is another domain of civilization parallel with social civilization, and an integral whole made up of four elements of civilization. As a domain of civilization, ecological civilization is constant and systematic in content, limited in connotation, and holds a fundamental value. The five–sphere integrated plan(economic, political, cultural, social and ecological progress) will combine the construction of the four elements of civilization and push forward the construction of an ecological civilization.

Investigation of absorption and scattering characteristics of kiwifruit tissue using a single integrating sphere system

For a quantitative understanding of light interaction with fruit tissue, it is critical to obtain two fundamental parameters： the absorption coefficient and the scattering coefficient of the tissue. This study was to investigate the optical properties of kiwifruit tissue at the wavelength of 632.8 nm. The total reflectance and total transmittance of kiwifruit tissue from three parts （including the flesh part, the seed part, and the seed-base part） were measured using a single integrating sphere system. Based on the measured spectral signals, the absorption coefficient pa and the reduced scattering coefficient Ps＇ of kiwifruit tissue were calculated using the inverse adding-doubling （lAD） method. Phantoms made from Intralipid 20% and India ink as well as a Biomimic solid phantom were used for system validation The mean values of μa and μs＇ of different parts of the kiwifruit were 0.031-0.308 mm-1 and 0.120-0.946 mm-1, respectively. The results showed significant differences among the Pa and Ps＇ of the three parts of the kiwifruit. The results of this study confirmed the importance of studying the optical properties for a quantitative understanding of light interaction with fruit tissue. Further investigation of fruit optical properties will be extended to a broader spectral region and different kinds of fruits.

Reaching a few 10-15 long-term stability of integrating sphere cold atom clock

We present the long-term stability of the integrating sphere cold atom clock（ISCAC） and analyze its systematic limitations. The relative frequency instability of 2.6 × 10-15 is reached for an averaging time of 2 ×105 s. The second-order Zeeman effect and the cavity pulling effect in ISCAC, which would induce the frequency drift from the clock transition, are analyzed. The analytical and experimental results indicate that the cavity pulling effect is the main contribution to the long-term frequency instability of the ISCAC. Further technical improvements to the microwave cavity are also discussed.

Development of an integrating sphere calibration method for Cimel sunphotometers in China aerosol remote sensing network

Based on the integrating sphere traced from the National Institute of Standards and Technology （NIST, USA）, a sphere calibration method and protocol for the China aerosol remote sensing network （CARSNET） Cimel sun photometer was established. Four CE318 sun photometers were verified using the proposed cal- ibration method and operational protocol. The calibration results showed that the instrument coefficients differed by less than 3% for visible （-5% for infrared） wavelengths from the original ones stated by Cimel Electronique. In situ validation experiment data showed that radiances at ±6° measured by sun collimator （aureole） were consistent with those measured by sky collimator （sky）, under both almucantar （ALMUC） and principal plane （PPLAN） scenarios. Differences at all wavelengths were less than 1%, indicating that the method and protocol are suitable for CARSNET field sun photometer calibration, and would benefit improvement of data quality and accuracy of network observations.

Effect of light beam on measurements of reflectance and transmittance of turbid media with integrating sphere： Monte Carlo simulation

Integrating sphere technique is widely used to measure the total reflectance and transmittance of turbid sample, but the unavoidable light loss induces some measuring error. It has never been reported whether the error depends on the shape and size of light beam. In this paper, a convolution for computing the responses to rectangular incident light beam based on the Monte Carlo method was presented. The effects of light beam shape and size, and optical properties of sample on the measurements were addressed. The results show that the light loss with rectangular incident light beam is larger than that with circular one with the same area. The more the area of light beam, the more the light loss. And the light loss induced by the optical properties of sample is much more significant than that by the shape and size of the incident light beam.

Effect of purification,dehydration,and coagulation processes on the optical parameters of biological tissues

In this study,the effects of purification,dehydration,and coagulation processes on the absorption and reduced scattering coefficients of chicken liver tissues have been investigated by using a single integrating sphere system.The purification process performed on the tissue samples to remove blood residue has been found to cause a slight change in the optical parameters.Although the dehydration process brings about an increase in the absorption coefficient due to the water loss,no direct relationship has been observed between the reduced scattering coefficient and the dehydration level of the tissue.In addition,it has been observed that there was a relatively small increase in the absorption coefficient and a significant increase in the reduced scattering coefficient after the coagulation process.Therefore,it can be said that the optical penetration depth decreased significantly after dehydration and coagulation processes unlike blood purification.Moreover,fluence rate distributions inside the fresh,blood purified,dehydrated,and coagulated tissue models have been investigated by using the Monte Carlo modeling of photon transport in multilayered tissues simulation code.

Adjustable contrast optical target device for test of acquisition of photoelectric theodolite

A new device used to detect the low contrast target acquisition of photoelectric theodolite is designed and its reliability is experimentally demonstrated.The adjustable contrast optical target device,which can simulate the sky background luminance and a low contrast target,is established.It utilizes a big integrating sphere and a small one to simulate the luminance of the background and target respectively.Importantly,by controlling the luminous flux of the two integrating spheres,the targets and background radiance can be continuously adjustable under the condition of constant color temperature.Thus,the contrast can be controlled continuously in the range of 0%-90% and its stability is better than 1%.The biggest background luminance exceeds 60 W m-2str-1 in the spectral range of 400-800 nm.