Glucose Concentration In Solution Research Articles

Effect of Freezing Time and Shaking Speed on the Performance of Progressive Freeze Concentration via Vertical Finned Crystallizer

Performance of a newly developed freeze concentrator named Vertical Finned Crystallizer (VFC) in concentrated glucose solution was evaluated. The VFC was designed as an attempt to provide an efficient Progressive Freeze Concentration (PFC) system by providing larger heat transfer area for crystallization. Glucose solution at an initial concentration of 11°Brix was concentrated through the new PFC system. The performance of the crystallizer was analyzed in parallel with the effect of freezing time and shaking speed to the system efficiency, represented by effective partition constant (K) and solute recovery (Y). The results show that the efficiency of the system has significantly improved portrayed by the lowest K value obtained of 0.383 and the highest Y value obtained of 0.96 g glucose/g initial glucose at intermediate circulation time and shaking speed. Thus, the VFC is evidently proven to have a high potential to be integrated in a PFC process as an efficient concentration system. The results obtained offer some guidelines on how to produce an efficient PFC system through parameter setting.

Asymmetrical microring resonator based on whispering gallery modes for the detection of glucose concentration

The optical resonator based on whispering gallery modes (WGMs) was widely studied due to its application potential in many fields. The novel asymmetrical microring resonator was proposed and investigated numerically using finite-difference time-domain (FDTD) method in this paper. The asymmetry of the asymmetrical microring resonator structure was reflected in the material and the structure of the microring resonator. The Q factor of the proposed asymmetrical microring, which was a significant parameter to measure the performance of microresonators, was more than five times of conventional microring resonator while maintaining the same sensitivity. The simulation verified that the structure can be applied to the detection of glucose solution concentration. This provided the potential for high-performance microring resonator to integrate on chip-scale devices for biosensing.

Glucose solution concentration detection using TE011 microwave resonant cavity

ABSTRACTIn this paper, a glucose solution concentration measurement method is proposed based on microwave resonant cavity perturbation technique. The mathematical model of TE011 cylindrical resonator in terms of solution concentration is derived. The optimal geometry of cavity is determined by high frequency structure simulator. A brass cavity with a PVC capillary tube is produced in this study. A microwave measurement system consisting of resonator, waveguide and network analyzer is constructed to measure glucose concentrations from 70 to 150 mg/dl, using frequency range 7.539–7.546 GHz. Statistical results indicate that the resonant frequency of solution increases linearly as glucose concentration increases. Frequency shift slope (FSS) of experiment is in good accordance with the FSS of theoretical calculation, which shows the feasibility and accuracy of the method.

Pleural Coating by 50% Glucose Solution Reduces Postoperative Recurrence of Spontaneous Pneumothorax

Video-assisted thoracoscopic surgery is the standard procedure for treatment of spontaneous pneumothorax. However, postoperative recurrence is relatively common even if an absorbable covering sheet is used for reinforcement of the visceral pleura. Injection of a high concentration glucose solution to the thoracic cavity was recently reported to be effective in stopping postoperative air leakage or as a prophylactic procedure to prevent postoperative recurrence of spontaneous pneumothorax. Therefore, we used 50 mL of a 50% glucose solution for pleural coating (GPC) on an absorbable sheet intraoperatively to prevent postoperative recurrence of spontaneous pneumothorax. This is a retrospective study, and patient backgrounds are heterogeneous. We evaluated the feasibility of GPC using propensity scores to adjust for heterogeneity in their backgrounds. Between January 2010 and December 2017, 376 patients who underwent video-assisted thoracoscopic surgery, with or without GPC, were evaluated. The GPC group consisted of 106 patients, and the non-GPC group consisted of 270. We analyzed the factors preventing postoperative recurrence of spontaneous pneumothorax by univariate analysis and Cox regression analysis with or without propensity score matching. Univariate analysis revealed age of 25 or older, smoking habit, no history of an ipsilateral operation, and GPC were significant factors preventing postoperative recurrence. GPC significantly prevented postoperative recurrence as shown by Cox regression analysis with propensity score matching (hazard ratio, 0.15; p= 0.014) and the inverse-probability of treatment weighted method (hazard ratio, 0.23; p= 0.0038). Intraoperative GPC significantly reduced the postoperative recurrence rate of spontaneous pneumothorax.

Determination of NIR informative wavebands for transmission non-invasive blood glucose measurement using a Fourier transform spectrometer

Non-invasive blood glucose measurement using near infrared (NIR) spectroscopy relies on wavebands that provide reliable information about spectral absorption. In this study, we investigated wavebands which are informative for blood glucose in the NIR shortwave band (900∼1450 nm) and the first overtone band (1450∼1700 nm) through a specially designed NIR Fourier transform spectrometer (FTS), which featured a test fixture (where a sample or subject’s finger could be placed) and all-reflective optics, except for a Michelson structure. Different concentrations of glucose solution and seven volunteers who had undergone oral glucose tolerance tests (OGTT) were studied to acquire transmission spectra in the shortwave band and the first overtone band. Characteristic peaks of glucose absorption were identified from the spectra of glucose aqueous solution by second-order derivative processing. The wavebands linked to blood glucose were successfully estimated through spectra of the middle fingertip of OGTT participants by a simple linear regression and correlation coefficient. The light intensity difference showed that glucose absorption in the first overtone band was much more prominent than it was in the shortwave band. The results of the SLR model established from seven OGTTs in total on seven participants enabled a positive estimation of the glucose-linked wavelength. It is suggested that wavebands with prominent characteristic peaks, a high correlation coefficient between blood glucose and light intensity difference and a relatively low standard deviation of predicted values will be the most informative wavebands for transmission non-invasive blood glucose measurement methods. This work provides a guidance for waveband selection for the development of non-invasive NIR blood glucose measurement.

Fiber-Optic Biosensor to Detect pH and Glucose

In this paper, we propose fast, highly sensitive, and wide-dynamic-range fiber-optic probe-type biosensors to detect pH and glucose. The operation principle of the proposed biosensors is based on the Fabry-Perot interferometry technique. Three pH-sensitive dyes (methyl orange, methyl red, and thymol blue) and three solvatochromic dyes (Nile red, rhodamine-B, and 4-amino-N-methylphthalimide) were individually mixed with polymers to obtain five pHand three glucose-sensitive sensing membranes. These membranes were subsequently deposited on eight gold nanoparticles coated on fiber-optic probes to obtain five pH and three glucose fiber-optic probe sensors. To ascertain the effectiveness of the sensors, various concentrations of pH buffer solutions and glucose solutions were tested. The proposed fiber-optic pH and glucose probe sensors showed sensitivities of 1.95 nm/pH and 3.25 nm/mM, respectively, with high-sensing stability with the relative standard deviation about 2.5%. The proposed sensors offer a linear sensing ability over wide ranges of pH (2-12) and glucose (1 μM-1 M) with an R 2 value of approximately 0.996. The response and recovery times of the proposed sensors were approximately 8 and 9 s, respectively. Finally in this paper, we compared the performance of the proposed fiber-optic probe sensors with that of other pH and glucose sensors and determined that the proposed sensors achieve better sensing performance.

Utilization of data classification in the realization of a surface Plasmon resonance readout system using an FPGA controlled RGB LED light source

This paper presents the realization of a surface plasmon resonance (SPR) sensor readout system using a tricolor red, green, and blue light emitting diode light source. Time domain intensity modulation of each color channel is applied to interrogate three bands of interest in the SPR spectrum using a single photodiode detector. A low computing resource classification approach is used through the combination of k-nearest neighbor (kNN) and adapted clustering using representative. An optimized number of representatives is chosen in the validation process to reduce the required amount of data for the kNN classification. This scheme was used to classify the concentrations of different glucose solutions. The sensor readout system hardware is based on the use of a field programmable gate array and the glucose solution classification is developed and undertaken on a personal computer using the Python open source programming language.

High sensitivity glucose detection at extremely low concentrations using a MoS2-based field-effect transistor.

In recent years, molybdenum disulfide (MoS2) based field-effect transistors (FETs) have attracted much attention because of the unique properties of MoS2 nano-materials as an ideal channel material. Using a MoS2 FET as a glucose solution biosensor has the advantages of high sensitivity and rapid response. This paper is concerned with the fabrication of a bilayer MoS2-based FET and the study of its application in the high sensitivity detection of an extremely low concentration glucose solution. It was found that the source-drain current (Ids) increases as the concentration of the glucose solution increases at the same gate voltage (Vgs) and drain voltage (Vds). The sensitivity of the biosensor as high as 260.75 mA mM−1 has been calculated and the detection limit of 300 nM was measured. The unknown concentration of a glucose solution was also detected using data based on the relationship between Ids and glucose solution concentration. In addition, many significant advantages of the biosensor were observed, such as short response time (<1 s), good stability, wide linear detection range (300 nM to 30 mM) and the micro-detection of glucose solutions. These unique properties make the bilayer MoS2-based FET a great potential candidate for next generation biosensors.

A large-area, wide-incident-angle, and polarization-independent plasmonic color filter for glucose sensing

We develop an effective method for glucose sensing by using a plasmonic color filter (PCF) integrated with a microfluidic chip. The morphology of PCF is composed of hybrid nanopillars fabricated with SiO2 and Au thin-films on silicon substrate. It exhibits angle-independence, polarization-independence and wafer-level fabrication, which are the most important factors for color filters for industrial applications. The shift of resonant wavelength is 56 nm with a stable bandwidth (∼30 nm) by varying concentration of glucose solution. The sensitivity is 157.61 nm/RIU and the corresponding figure-of-merit is 5.25. Such strategy can be exploited to further increase the detection and potentially enter the ultra-strong coupling regime in chemical solution sensors.

High sensitivity optical biosensor based on polymer materials and using the Vernier effect.

We demonstrate the fabrication of a Vernier effect SU8/PMATRIFE polymer optical biosensor with high homogeneous sensitivity using a standard photolithography process. The sensor is based on one micro-resonator embedded on each arm of a Mach-Zehnder interferometer. Measurements are based on the refractive index variation of the optical waveguide superstrate with different concentrations of glucose solutions. The sensitivity of the sensor has been measured as 17558 nm/RIU and the limit of detection has been estimated to 1.1.10-6 RIU.

Enzyme kinetics of cellulose hydrolysis of Miscanthus and oat hulls.

Experiments were done to model enzymatic hydrolysis of Miscanthus and oat hulls treated with dilute solutions of nitric acid and sodium hydroxide in direct and reverse sequences. The enzymatic hydrolysis kinetics of the substrates was studied at an initial solid loading from 30 to 120g/L. The effects of feedstock type and its pretreatment method on the initial hydrolysis rate and reducing sugar yield were evaluated. The fitting results by the developed models showed good agreement with the experimental data. These models designed for developing the production technology of concentrated glucose solutions can also be applied for glucose fermentation into ethanol. The initial solid loading of 60-90g/L provides the reducing sugar concentration of 40-80g/L necessary for ethanol synthesis. The kinetic model can also be applied to investigate enzymatic hydrolysis of other substrates (feedstock type, pretreatment method) under the similar conditions used herein, with adjusted empirical coefficient values.

Flow-through micro-capillary refractive index sensor based on T/R spectral shift monitoring.

We present a flow-through refractive index sensor for measuring the concentration of glucose solutions based on the application of rectangular glass micro-capillaries, with channel depth of 50 µm and 30 µm. A custom designed and 3D printed polymeric shell protects the tiny capillaries, ensuring an easier handling and interconnection with the macro-fluidic path. By illuminating the capillary with broadband radiation centered at λ~1.55 µm, both the transmitted (T) and reflected (R) optical spectrum from the capillary are detected with an optical spectrum analyzer, exploiting an all-fiber setup. Monitoring the spectral shift of the ratio T/R in response to increasing concentration of glucose solutions in water we have obtained sensitivities up to 530.9 nm/RIU and limit of detection in the range of 10-5-10-4 RIU. Experimental results are in agreement with the theoretically predicted principle of operation. After the demonstration of amplitude detection at a single wavelength, we finally discuss the impact of the capillary parameters on the sensitivity.

A correlation of results measured by cyclic voltammogram and impedance spectroscopy in glucose oxidase based biocatalysts

A new biocatalyst consisting of glucose oxidase (GOx) and polyethylenimine (PEI) immobilized on carbon nanotube (CNT) (CNT/PEI/GOx) was developed, while cyclic voltammogram (CV) behaviors of several related catalysts including the CNT/PEI/GOx were analyzed in terms of charge transfer resistances (R ct s) obtained by measuring Nyquist plots using electrochemical impedance spectroscopy (EIS). A qualitative correlation between the flavin adenine dinucleotide (FAD) redox reactivity measured by the CV and R ct was established. As factors affecting both the FAD reactivity and R ct , concentrations of GOx, glucose, and phosphate buffer solution, electrolyte pH and ambient condition were considered and evaluations of the catalysts using the CV curves and Nyquist plots confirmed that a pattern in the FAD reactivity was closely linked to that in the R ct , implying that FAD reactivities of the catalysts are predicted by the measurements of their R ct s. Even regarding performance of the enzymatic biofeul cells (EBCs) using the reacted catalysts, a pattern of the R ct s is compatible with that in the maximum power densities (MPDs) of the EBCs.

High-sensitivity complex refractive index sensing based on Fano resonance in the subwavelength grating waveguide micro-ring resonator.

High-sensitivity complex refractive index sensing is proposed and experimentally demonstrated, favoring with sharp Fano resonance at 1550 nm wavelength based on subwavelength grating waveguide (SWG) micro-ring resonator. The micro-ring is composed by trapezoidal silicon pillars with subwavelength period to enhance the light-analyte overlap and get high quality factor as well. One straight SWG waveguide is side coupled with the micro-ring, which is specially designed to produce partial Fabry-Perot (FP) effect. Due to the interaction of resonant state of micro-ring and partial FP effect in straight waveguide, a sharp asymmetrical Fano resonance is formed at 1550 nm wavelength. Benefit from the large light-analyte overlap of the SWG waveguide structure and the sharp asymmetrical Fano resonance in spectrum, high theoretical sensitivities of 366 nm/RIU and 9700/RIU can be realized for the real part (n) and the imaginary part (κ) of refractive index respectively. We also experimentally demonstrate the sensing for glucose solution concentrations, and high experimental sensitivity of 363nm/RIU is obtained for n, and for κ the experimental results are also in well agreement with the simulation results.

Soil respiration and microbial biomass in multiple drying and rewetting cycles – Effect of glucose addition

Previous studies showed that the respiration flush upon rapid rewetting of dry soil decreases with increasing number of drying and rewetting (DRW) cycles which is thought to be due to various factors, for example, lower substrate availability or microbial biomass or changes in microbial community structure. To investigate if the reduction of respiration flush with increasing cycle number is due to lack of available substrate upon rewetting, incubation experiments with four DRW cycles were conducted where glucose solutions of different concentrations, low (50μgCg−1 soil), medium (250μgCg−1 soil) and high (500μgCg−1 soil) were added either in all four cycles or only in cycle 1, 2, 3 or 4 (the other cycles rewetted with water). Additional treatments included a constantly moist control (CM, 70% of maximum water-holding capacity) and DRW treatments with only RO water. When dry soil was rewetted only with RO water, the respiration flush upon rewetting was about twice as high in the first two cycles than in cycles 3 and 4. Soil microbial biomass C (MBC) one day after rewetting remained stable until cycle 3 after which it decreased by about 20%. In all glucose treatments, the glucose-induced increase in respiration rate was greater in earlier than later cycles, irrespective of whether glucose was added to one cycle only or in all cycles. But when expressed relative to CM, the respiration rate was greater in the last two cycles. Single glucose addition increased MBC only in the cycle in which it was added whereas repeated glucose addition increased MBC over time. Glucose addition and DRW increased the metabolic quotient, thus reduced C use efficiency. In treatments with glucose added in all four cycles, the metabolic quotient increased with DRW cycle number which indicates lower efficiency in later cycles. It is concluded that lower substrate availability can be one of the reasons for the decrease in respiration flush upon rewetting with cycle number.

A19 キャビテーション処理されたグルコース水溶液の近赤外分光測定からの濃度回帰(口頭発表)

A19 キャビテーション処理されたグルコース水溶液の近赤外分光測定からの濃度回帰(口頭発表)

Study on the Application of Electric Field to Giant Vesicles Comprised of 1,2-Dilauroyl-Sn-Glycero-3-Phosphatidylcholine Using Optical Fluorescence Microscopy

The influence of alternating electric field (AC) in the structure and dynamics of giant unilamellar vesicles (GUVs) comprised of 1,2-dilauroyl-sn-glycero-3-phosphatidylcholine (DLPC) is reported. The investigations were conducted by using optical fluorescence microscopy as the method of analysis. The lipid membrane of the DLPC GUVs at the fluid phase can be deformed and they migrate towards the electrodes under AC electric field. Nevertheless, membrane disruption or vesicle fusion was never noticed. The addition of concentrated glucose solution influences the osmotic pressure of the system leading to the formation of filaments at the outer region of the GUVs. These long flexible cylinders do not retract spontaneously. However, the application of AC electric field (20 V/mm, 20 Hz) enables the filaments to be retracted back to the GUVs membrane at a calculated speed of 0.18 µm.s-1

A non-invasive photoacoustic and ultrasonic method for the measurement of glucose solution concentration

Diabetes mellitus (DM) is a chronic disease affecting nearly 400 million people worldwide. In order to manage the disease, patients need to monitor the blood glucose level by puncturing the finger several times a day, which is uncomfortable and inconvenient. We present here a potential non-invasive monitoring method based on the velocity of ultrasonic waves generated in glucose solution by the photoacoustic principal, which can recognize the glucose concentration down to 20mg/dL. In order to apply this method to warm bodies, we carefully designed the experiment and performed measurements from 30 °C to 50 °C to generate a set of calibration curves, which may be used by engineers to build devices. Most importantly, we have theoretically explained the relationship between the compressibility and the glucose concentration. Our results show that the compressibility of solution decreases with the glucose concentration, which clarified the controversy between theory and experiment results in the literature. The derived formula is generally validity, which can be used to nondestructively measure solution concentration for other types of solutions using photoacoustic principle.

Glucose solution determination based on liquid photoacoustic resonance.

Noninvasive blood glucose determination has received considerable attention in the past from both patients and scientists all over the world, and it is becoming increasingly important as a research focus. The two most difficult problems leading to no breakthrough in this area are sensitivity and specificity in determination. In order to obtain reliable measurement results of blood glucose levels, we propose a new liquid photoacoustic resonance theory that can significantly enhance the intensity of the signal and improve the sensitivity. This paper demonstrates the theory of liquid photoacoustic resonance, gives a rigorous mathematical expression, and analyzes the variation of the transducer output in the case of liquid photoacoustic resonance. A signal processing method is demonstrated at the same time under the liquid photoacoustic resonance condition. Meanwhile, the feasibility and validity are verified by experiments with different concentrations of glucose solution. The result shows that liquid photoacoustic resonance can strengthen the signal, and the resolution achieves 20 mg/dL. This method overcomes the issue of low sensitivity and the inaccurate detection in the nonresonant case, and gets accurate results. This result could provide a theoretical basis for realization of noninvasive measurement of blood glucose.

基于腐蚀光纤的温度及葡萄糖溶液浓度传感器

基于腐蚀光纤的温度及葡萄糖溶液浓度传感器