D-glucose Solution Research Articles

Influence of Electrostatic Field on Optical Rotation of D-Glucose Solution: Experimental Research for Electric Field-Induced Biological Effect

At present, the effects of environmental electromagnetic irradiation on the metabolism of organisms have attracted extensive attention, but the mechanism is still not clear. D-glucose plays an important role in the metabolism of organisms. In this work, the change in the optical rotation of D-glucose solution under an electrostatic field is measured experimentally, so as to explain the mechanism of the electric field-induced biological effect. The experimental results show that the electrostatic field can alter the optical rotation of D-glucose solution at different temperatures. Under the different strengths of electrostatic field, the specific rotation of D-glucose solution increases at different temperatures; the maximum increase can reach 2.07%, but the effect of temperature and electric field strength on the rotation increment is nonlinear and very complex. Further, it turns out that the proportion of α-D-glucose in solution increases by up to 3.25% under the electrostatic field, while the proportion of β-D-glucose decreases by as much as 1.75%. The experimental study confirms that electrostatic field can change the proportion of two conformation molecules (α and β-D-glucose) in D-glucose solution, which can provide a novel explanation for the mechanism of the electric field-induced biological effect.

Facile modification method for the controlled synthesis of dumbbell-like gold nanoparticles (AuNDBs) for application in detecting glucose using the SERS method

Dumbbell-like nanoparticles, previously known for their excellent light absorption and dispersion, have diverse applications, especially in SERS. Herein, we have explored a fast and novel controlled synthesis approach to achieve a high formation of AuNDBs. Precise control of precursor amounts and seed addition order halted seed growth at the AuNDB formation stage, preventing further elongation into rod-like structures. The AuNDBs were functionalized with 4-mercaptobenzoic acid (4-MBA) to create SERS nanosubstrates and deposited on the glass slide through 3-mercaptopropyl (dimethoxy)methylsilane by the spin-coating technique. The detection of d-glucose was achieved by measuring the signal decrease of the 4-MBA Raman probe molecules on the nanosubstrates at different trace concentrations of the analyte. These novel SERS substrates have the potential to provide an enhancement factor (EF) of 2.41 × 107 and a limit of detection (LOD) as low as 1.17 nmol/L. The electromagnetic field distribution of AuNDBs with many arrangements surrounded by air and d-glucose solutions was also determined by using the finite-difference time-domain technique (FDTD). The FDTD results confirmed that d-glucose on the SERS substrates caused the local electromagnetic field to degrade, resulting in the degree of the Raman signal. Our findings suggest that dumbbell-shaped SERS substrates can effectively detect very low levels of glucose, making them ideal for designing novel anisotropic nanoparticle-functionalized surfaces with ease.

Tensiometric and Thermodynamic Study of Aliphatic and Aromatic Amine in Aqueous D-Glucose Solutions: A Comparative Study

The surface tensions of aqueous taurine (TAU) and tyramine (TYR) with D-glucose mixed solvents were elevated from 298.15 to 318.15 K by the KSV sigma 702 tensiometer. The purpose of the study was to elucidate comparative studies of the thermodynamic and transport aggregation properties of aliphatic and aromatic amine, i.e., taurine and tyramine, which provide information in pharmacology and biochemistry. The experimental data investigated by this study were utilized to evaluate various interfacial parameters, including surface pressure, surface excess concentration, and other thermodynamic parameters of surface assembly, which are discussed in terms of solute–solvent and solute–solute interactions. The surface tension data have been analyzed using the Gibbs adsorption isotherm. The results signify that the negative isotherm exhibited by the ionic solute, i.e., taurine, an aliphatic amine, is contrary to the positive isotherm of tyramine, a biogenic aromatic amine. Both the amines exhibit surface properties such as surfactant molecules, which is elucidated in terms of ionic–hydrophilic and hydrophobic–hydrophobic interactions. The positive entropy values state that the process of surface formation is favored by entropy gain as well as the enthalpy effect. The present system provides a better understanding of the intermolecular interactions, which are required for their usefulness in the field of nutrition, pharmacy, and the food industry.

SpectIR-fluidics: completely customizable microfluidic cartridges for high sensitivity on-chip infrared spectroscopy with point-of-application studies on bacterial biofilms.

We present a generalizable fabrication method for a new class of analytical devices that merges virtually any microfluidic design with high-sensitivity on-chip attenuated total reflection (ATR) sampling using any standard Fourier transform infrared (FTIR) spectrometer. Termed "spectIR-fluidics", a major design feature is the integration of a multi-groove silicon ATR crystal into a microfluidic device, compared with previous approaches in which the ATR surface served as a structural support for the entire device. This was accomplished by the design, fabrication, and aligned bonding of a highly engineered ATR sensing layer, which con```tains a seamlessly embedded ATR crystal on the channel side and an optical access port that matched the spectrometer light path characteristics at the device exterior. The refocused role of the ATR crystal as a dedicated analytical element, combined with optimized light coupling to the spectrometer, results in limits of detection as low as 540 nM for a D-glucose solution, arbitrarily complex channel features that are fully enclosed, and up to 18 world-to-chip connections. Three purpose-built spectIR-fluidic cartridges are used in a series of validation experiments followed by several point-of-application studies on biofilms from the gut microbiota of plastic-consuming insects using a small portable spectrometer.

Electrical properties of the sensory neuron and defense reactions of mollusc Lymnaea stagnalis at conditions of prolonged hyperglycemia

Hemolymph glucose level rise (from 0.12 (0.05; 0.18) to 4.10 (3.18; 6.08) mmol/L) modify the defensive behaviour of molluscs. This results in increase of the degree of animal’s body retracted into the shell and in reinforcement of weak defense reactions in response to tentacles’ tactile stimulation. No fluctuations in the tentacles length and the duration of the latent period of protraction were found. At experimental hyperglycemia (incubation of the isolated CNS preparation in 10 mmol/L D-glucose solution for 2 h), the basic electrical characteristics of FMRFamide-containing neuron RPaD1, involved in sensory stimuli detection and heart beat regulation in Lymnaea, were changed. Membrane depolarisation, accompanied by firing rate increase were observed, while current-voltage curve characteristics, as well as membrane resistance, capacity and time constant remains unchanged in comparison with control. An increase in rising and falling phases duration, undershoot amplitude were noted, while other parameters of the RPaD1 spike remained unchanged. Based on the revealed features of the action potential shape at hyperglycemia, it is assumed that these changes can be caused by the activation of the Na+-glucose co-transporter and ATP-sensitive K+-channels of the RPaD1 membrane. The action of glucose should be considered as a metabolic signal also in relation to non-feeding neurons in the mollusc brain.

Mn/carbon sphere catalyst for heterogeneous activation of peroxymonosulfate for methylen blue removal

One of the latest innovations in textile waste treatment is advanced oxidation processes (AOPs) methods using an oxidizing agent capable of producing sulfate radicals (SO4•). This study aims to determine the activity of the Mn/Carbon sphere catalyst in the oxidation process, reduce the dye content by using a combination of peroxymonosulfate (PMS) and Mn/Carbon sphere catalyst as an oxidizing agent, and determine the optimum conditions in the process of reducing dye levels in the water. A hydrothermal process carried out the catalyst synthesis process to produce black carbon from D-glucose solution, then impregnated with variations of 3% and 5% of Mn metal. The degradation of methylene blue (artificial waste) of 25mg/L (1:10 dilution) was carried out for 120 minutes with variations in the catalyst mass of 0.001, 0.002, 0.003, and 0.004g and the mass of PMS 0.01, 0.02, 0.03, and 0, 04g in 100ml sample. Mn/Carbon sphere catalyst was able to activate PMS and was able to degrade methylene blue by 88.16%. The optimum condition for reducing the methylene blue levels in the water is at a concentration of 1g/L PMS and a Mn/Carbon sphere catalyst (5% Mn metal) 0.5g/L with an efficiency of 88.16%.

A new approach to the synthesis of nanosized powder CaO and its application as precursor for the synthesis of calcium borates

A procedure for the synthesis of calcium oxide has been developed, which consists in heat treatment of an aqueous solution of calcium acetate and d-glucose at 350 and then at 700 °C. The process parameters have been determined. It has been shown that when d-glucose is used and the reaction mixture is heat treated at 700 °C, highly dispersed calcium oxide with an average particle size of 77 nm is formed. CaO formed has been used as a precursor for the synthesis of priceite (Ca2(B5O7)(OH)5 · H2O) during hydrothermal treatment of CaO in an aqueous solution of boric acid. It has been found that the optimal conditions for the synthesis of monophase priceite under hydrothermal conditions include the temperature range of 170–200 °C and the heating time of 12 h. When heating priceite at 800 °C in air for 1 h, highly dispersed powder calcium bis(borate) Ca(BO2)2 has been isolated as the final product. It is shown that the use of synthesized powder CaO leads to the formation of fine-crystalline powders of calcium borates. Samples obtained at each stage of the proposed synthesis of highly dispersed calcium oxide and calcium borates, using the example of priceite and calcium bis(borate), have been studied by powder X-ray diffraction, SEM, TEM, BET, IR spectroscopy, and DTA.

Bioconversion study for xylitol and ethanol production by Debaryomyces hansenii: aeration, medium and substrate composition influence

Debaryomyces hansenii has been employed to study, initially, the influence of the oxygen availability on D-xylose to xylitol fermentation, as this parameter is considered as one of the most critical variables for this bio alcohol accumulation. Apart from the air supplied in the fermentation process through the stirring vortex (0.0 v/v/min), additional aeration rates (0.1–2.0 v/v/min) effects were discussed. Furthermore, a change in the fermentative medium composition as well as a comparative analysis of D. hansenii behavior with respect to fermentation of D-glucose and D-xylose mixtures solutions, with the aim of producing both xylitol and ethanol bioproducts, were performed. For these purposes, specific growth rates, biomass productivities, specific substrate-uptake rates, overall biomass yields, specific xylitol formation rates and overall xylitol yields values have been calculated, applying a differential method to the kinetic data. Aeration influence was clearly evinced since a faster D-xylose metabolism, for aeration values close to 1.0 v/v/min, was noted. This yeast exhibited a sequential substrate consumption, firstly D-glucose and then D-xylose. The maximum xylitol yield (0.32 kg kg– 1) was obtained for 0.5 v/v/min airflow, remarking a significant reduction of this parameter for both above and below the quoted air supply value.

Salting- in effect of deep eutectic solvents on the aqueous solutions of D-glucose by using isopiestic method

In this work, the salting-in effect of some deep eutectic solvents (DESs) based on choline chloride on the aqueous solutions of D-glucose using the vapor–liquid equilibrium (VLE) data were investigated. The water activity data were obtained precisely using an improved isopiestic method and correlated with Wilson, e-NRTL, and UNIQUAC models. Also, the Hansen solubility parameters were calculated to predict the selection of appropriate solvent system. The e-NRTL model was employed to calculate activity coefficient, and the Gibbs free energies of transfer of D-glucose from water to aqueous DES solutions. Isoactivity lines of water in all systems show a large positive deviation from the linear isopistical relation (Stokes-Robinson's Zdanovskii law), which is due to the salting-in effect. The results indicate that the salting-in effect is greater in the presence of glycerol based DES and show strong interactions between D-glucose and the DES and is favorable.

Multiphoton imaging of the effect of monosaccharide diffusion and formation of fluorescent advanced end products in porcine aorta.

Prolonged exposure of tissues to elevated blood sugar levels lead to the formation of advanced glycation end products (AGEs), thus contributing to diabetic complications. Since the vascular system is in immediate contact with blood, diabetic effects on aorta is a major health concern. However, the relative effect of the diffusion of sugar molecular through the vascular wall and the rate of AGE formation is not known. In this study, we aim to address this issue by incubating excised porcine aorta in D-glucose, D-galactose, and D-fructose solutions for different periods. The tissue specimens were then excised for multiphoton imaging of autofluorescence intensity profiles across the aorta wall. We found that for Days 4 to 48 incubation, autofluorescence is constant along the radial direction of the aorta sections, suggesting that monosaccharide diffusion is rapid in comparison to the rate of formation of fluorescent AGEs (fAGEs). Moreover, we found that in porcine aorta, the rate of fAGE formation of D-fructose and D-glucose are factors 2.08 and 1.14 that of D-galactose. Our results suggest that for prolonged exposure of the cardiovascular system to elevated monosaccharides 4 days or longer, damage to the aorta is uniform throughout the tissues.

L-Citrulline ameliorates the attenuation of acetylcholine-induced vasodilation of retinal arterioles in diabetic rats

In our previous study, we found that the vasodilation of retinal arterioles induced by acetylcholine and BMS-191011, a large-conductance Ca2+-activated K+ (BKCa) channel opener, were diminished in diabetic rats. Currently, few agents ameliorate the impaired vasodilator responses of retinal blood vessels. Our recent finding that the intravenous infusion of L-citrulline dilated retinal arterioles, suggests that L-citrulline could be a potential therapeutic agent for circulatory disorders of the retina. In this study, we determined the effect of an oral L-citrulline treatment on impaired acetylcholine- and BMS-191011-induced vasodilation in the retinal arterioles of diabetic rats. To induce diabetes, rats were administered an intravenous dose of streptozotocin (65 mg/kg) and a 5% D-glucose solution as drinking water. The L-citrulline (2 g/kg/day) and L-arginine (2 g/kg/day) treatments commenced either 15 days before or just after the streptozotocin injection and continued throughout the experimental period. A 29-day treatment with L-citrulline, but not L-arginine, significantly ameliorated the impaired acetylcholine- and BMS-191011-induced retinal vasodilation in diabetic rats without affecting their plasma glucose levels. The 2-week L-citrulline treatment tended to ameliorate the dysfunction of the acetylcholine-induced retinal vasodilation in diabetic rats. In conclusion, these results showed that the retinal blood vessel dysfunction induced by diabetes mellitus could be prevented by the long-term administration of L-citrulline and suggest that the latter could play a potentially prophylactic role in diabetic retinopathy.

Agar/κ-carrageenan/montmorillonite nanocomposite hydrogels for wound dressing applications

In this study, agar/κ-carrageenan/montmorillonite (MMT) hydrogels were prepared to examine their usability as wound dressing materials and to see the effect of MMT amount on some properties of agar/κ-carrageenan hydrogel materials. Hydrogels were characterized by SEM-EDX, TEM and DSC analyses. By increasing the MMT content within hydrogel matrix from 0% to 5%, the decomposition temperature of the hydrogel material was increased from 256.6 °C to 262.1 °C. Swelling amount of hydrogels in d-glucose solution (2682%) was found to be much higher compared with other physiological solutions such as physiological saline solution (937%), synthetic urine solution (746%) and simulated wound fluid (563%). The release studies of analgesic lidocaine hydrochloride (LDC) and antibiotic chloramphenicol (CLP) drugs from hydrogel systems demonstrated that the release amount of LDC and CLP from hydrogels could be controlled by MMT amount within hydrogel matrix. The concentrations of drugs within hydrogel sample stored at 4 °C for 6 months did not exhibit a significant change. Hydrogel materials containing CLP exhibited good antibacterial activity against E. coli and S. aureus. Cytotoxicity test results indicated that hydrogels were biocompatible with MG-63 cells. The ultimate compressive stress of agar/κ-carrageenan hydrogel with LDC and CLP and agar/κ-carrageenan/MMT hydrogel including 5% MMT with LDC and CLP was measured as 38.30 kPa and 47.70 kPa, respectively. The experimental results revealed that prepared agar/κ-carrageenan and agar/κ-carrageenan/MMT hydrogels have great potential for wound care applications.

Highly integrated plasmonic sensor design for the simultaneous detection of multiple analytes

Herein, a highly integrated plasmonic sensor based on a multichannel metal-insulator-metal waveguide scheme for the simultaneous detection of multiple analytes is proposed. The numerical study is conducted via the finite element method based on commercially available software COMSOL. The sensor design is highly sensitive which can detect a minute change in the refractive index of the analyte. In this study, we have used the refractive index values of three different concentrations of ethanol and d-glucose solution to determine the sensor performance. It is observed that the device is highly sensitive as the operational wavelength lies in the deep shortwave infrared region. The numerically calculated sensitivity as high as 1948.67 nm/RIU is obtained for the cavity length of 325 nm which can be further improved by designing the device with large cavities. We believe that the proposed study is beneficial for the realization of the highly integrated plasmonic sensors for the lab-on-chip operations.

Simultaneous Voltammetric Determination of Uric Acid, Xanthine, and Hypoxanthine Using CoFe2O4/Reduced Graphene Oxide-Modified Electrode

In the present paper, the synthesis of cobalt ferrite/reduced graphene oxide (Co2Fe2O4/rGO) composite and its use for the simultaneous determination of uric acid (UA), xanthine (XA), and hypoxanthine (HX) is demonstrated. Cobalt ferrite hollow spheres were synthesized by using the carbonaceous polysaccharide microspheres prepared from aD-glucose solution as templates, followed by calcination. The CoFe2O4/rGO composite was prepared with the ultrasound-assisted method. The obtained material was characterized by using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, EDX elemental mapping, and nitrogen adsorption/desorption isotherms. The electrochemical behavior of UA, XA, and HX on the CoFe2O4/rGO-modified electrode was studied with cyclic voltammetry and differential pulse voltammetry (DPV). The modified electrode exhibits excellent electrocatalytic activity towards the oxidation of the three compounds. The calibration curves for UA, XA, and HX were obtained over the range of 2.0–10.0 μM from DPV. The limits of detection for UA, XA, and HX are 0.767, 0.650, and 0.506 μM, respectively. The modified electrode was applied to the simultaneous detection of UA, XA, and HX in human urine, and the results are consistent with those obtained from the high-performance liquid chromatography technique.

Improvement of dual‐glucose sensor specificity for prosthetic vascular grafts based on a calibration scheme

Glucose monitoring is an important clinical procedure, especially for dialysis patients who need consistent monitoring of their glucose levels. Currently, the most extensively used method for glucose monitoring involves pricking the finger and sampling a small amount of blood. Given that this procedure is inconvenient and can cause pain and potential infection, there is demand for the development of alternative glucose sensing methods. This study introduces a methodology for improved glucose sensor specificity based on a calibration scheme. One microwave and one capacitive glucose sensor were designed and placed on a prosthetic vascular graft. Each sensor yielded a finite variation in the measured glucose concentrations based on its capacity to sense permittivity changes in aqueous D-glucose solutions. However, as blood components other than glucose—such as proteins, erythrocytes and haemoglobin—may affect the measurements, the authors also introduced a calibration scheme to adjust and calibrate each measurement to ensure accuracy. The measurement data yielded a maximum error of <7.33%. Based on these outcomes, the specificity of glucose monitoring in prosthetic vascular grafts is validated.

Tunable Nanoporous Anodic Alumina Photonic Crystals by Gaussian Pulse Anodization.

This study presents a Gaussian pulse anodization approach to generate nanoporous photonic crystals with highly tunable and controllable optical properties across the visible-NIR spectrum. Nanoporous anodic alumina Gaussian photonic crystals (NAA-GPCs) are fabricated in oxalic acid electrolyte by Gaussian pulse anodization, a novel form of pulse-like anodization. The effect of the Gaussian pulse width in the anodization profile on the optical properties of these photonic crystals is assessed by systematically varying this fabrication parameter from 5 to 60 s. The optical features of the characteristic photonic stopband (PSB) of NAA-GPCs-the position of the central wavelength, full width at half-maximum, and intensity-are found to be highly dependent on the Gaussian pulse width, the angle of incidence of incoming photons, and the nanopore diameter of NAA-GPCs. The effective medium of NAA-GPCs is assessed by monitoring spectral shifts in their characteristic PSB upon infiltration of their nanoporous structure with analytical solutions of d-glucose of varying concentration (0.0125-1 M). Experimental results are validated and mechanistically described by theoretical simulations, using the Looyenga-Landau-Lifshitz effective medium approximation model. Our findings demonstrate that Gaussian pulse anodization is an effective nanofabrication approach to producing highly sensitive NAA-based PC structures with versatile and tunable PSBs across the spectral regions. The findings provide new exiting opportunities to integrate these unique PC structures into photonic sensors and other platform materials for light-based technologies.

D-glucose weighted chemical exchange saturation transfer (glucoCEST)-based dynamic glucose enhanced (DGE) MRI at 3T: early experience in healthy volunteers and brain tumor patients.

Dynamic glucose enhanced (DGE) MRI has shown potential for imaging glucose delivery and blood-brain barrier permeability at fields of 7T and higher. Here, we evaluated issues involved with translating d-glucose weighted chemical exchange saturation transfer (glucoCEST) experiments to the clinical field strength of 3T. Exchange rates of the different hydroxyl proton pools and the field-dependent T2 relaxivity of water in d-glucose solution were used to simulate the water saturation spectra (Z-spectra) and DGE signal differences as a function of static field strength B0 , radiofrequency field strength B1 , and saturation time tsat . Multislice DGE experiments were performed at 3T on 5 healthy volunteers and 3 glioma patients. Simulations showed that DGE signal decreases with B0 , because of decreased contributions of glucoCEST and transverse relaxivity, as well as coalescence of the hydroxyl and water proton signals in the Z-spectrum. At 3T, because of this coalescence and increased interference of direct water saturation and magnetization transfer contrast, the DGE effect can be assessed over a broad range of saturation frequencies. Multislice DGE experiments were performed in vivo using a B1 of 1.6 µT and a tsat of 1 second, leading to a small glucoCEST DGE effect at an offset frequency of 2 ppm from the water resonance. Motion correction was essential to detect DGE effects reliably. Multislice glucoCEST-based DGE experiments can be performed at 3T with sufficient temporal resolution. However, the effects are small and prone to motion influence. Therefore, motion correction should be used when performing DGE experiments at clinical field strengths.

Compact Inner-Wall Grating Slot Microring Resonator for Label-Free Sensing.

In this paper, we present and analyze a compact inner-wall grating slot microring resonator (IG-SMRR) with the footprint of less than 13 μm × 13 μm on the silicon-on-insulator (SOI) platform for label-free sensing, which comprises a slot microring resonator (SMRR) and inner-wall grating (IG). Its detection range is significantly enhanced without the limitation of the free spectral region (FSR) owing to the combination of SMRR and IG. The IG-SMRR has an ultra-large quasi-FSR of 84.5 nm as the detection range, and enlarged factor is up to over 3 compared with the conventional SMRR. The concentration sensitivities of sodium chloride solutions and D-glucose solutions are 996.91 pm/% and 968.05 pm/%, respectively, and the corresponding refractive index (RI) sensitivities are 559.5 nm/RIU (refractive index unit) and 558.3 nm/RIU, respectively. The investigation on the combination of SMRR and IG is a valuable exploration of label-free sensing application for ultra-large detection range and ultra-high sensitivity in future.

A green and easy way for carbon microspheres synthesis impregnated with palladium for hexavalent chromium reduction

Hexavalent chromium is a toxic heavy metal widely spread due to industrial activities around the world. Therefore, to treat wastewaters with this hazardous metal, carbon microspheres were synthesized from a 1.4 mol/L D-glucose solution heated in a closed vessel at 180 °C for 24 h. This carbon material was already functionalized with acid sites which may act as anchor groups for different ions removal. With this hydrothermal and eco-friendly method, it was possible to prepare carbon microspheres with 262 m2/g of surface area, 15 μm of average particle size and a total acidity of 3.13 mmol/g. Activated carbon of 1400 m2/g was oxidized as well with HNO3 in order to compare its activity with carbon microspheres in Cr(VI) reduction. Finally, Pd was impregnated on both carbon materials to reduce Cr(VI) with formic acid as reducing agent. The composite with Pd impregnated on carbon microspheres resulted to be the best catalyst since it reduced Cr(VI) in 150 min.

Non-enzymatic D-glucose plasmonic optical fiber grating biosensor

Saccharide sensors represent a broad research area in the scope of sensing devices and their involvement in the medical diagnosis field is particularly relevant for cancer detection at early stage. In that context, we present a non-enzymatic optical fiber-based sensor that makes use of plasmon-assisted tilted fiber Bragg gratings (TFBGs) functionalized for D-glucose biosensing through polydopamine (PDA)-immobilized concanavalin A (Con A). Our probe allows a live and accurate monitoring of the PDA layer deposition leading improved surface biochemistry. The SPR shift observed was assessed to 3.83 ± 0.05 nm within 20 min for a 2 mg/mL dopamine solution. Tests performed in different D-Glucose solutions have revealed a limit of detection close to 10−7 M with the highest sensitivity in the 10−6 to 10−4 M range. This configuration has the capability to overcome the limitations of current enzyme-based solutions.