Concentration Ratio Research Articles

Drug-drug interactions between letermovir and tacrolimus in Japanese renal transplant recipients simulated using a physiologically based pharmacokinetic model.

Letermovir (LET) is a novel antiviral agent recently approved for cytomegalovirus (CMV) prophylaxis of renal transplant patients in Japan. However, its interactions with tacrolimus (TAC), an important immunosuppressant, remain ambiguous, warranting careful evaluation considering the unique genetic and physiological characteristics of Japanese patients. Therefore, in this study, we aimed to investigate the drug-drug interactions between LET and extended-release TAC (ER-TAC) in Japanese renal transplant patients via physiologically based pharmacokinetic (PBPK) modeling. We developed PBPK models for LET and TAC, including a new model for ER-TAC, using the Simcyp simulator. We also created a virtual Japanese post-transplant population by incorporating physiological parameters specific to Japanese patients, including CYP3A5 genotypes. Our model accurately predicted the pharmacokinetics of both immediate-release and ER-TAC co-administered with LET. In the Japanese population, LET significantly increased ER-TAC exposure, with the effect varying by CYP3A5 genotype. For CYP3A5*1 carrier, the area under the curve ratio ranged from 2.33 to 2.53, while for CYP3A5*3/*3 carriers, it ranged from 2.82 to 2.86. The maximum concentration ratio was approximately 1.50 across all groups. Our findings suggest reducing the ER-TAC dose by approximately 57-60% for CYP3A5*1 carrier and 65% for CYP3A5*3/*3 carriers when co-administered with LET for Japanese renal transplant patients. Moreover, the developed model incorporating population-specific factors, such as hematocrit values and CYP3A5 genotype frequencies, is a valuable tool to evaluate complex drug interactions and guide the dosing strategies for LET and TAC in Japanese patients. Overall, this study expands the application of PBPK modeling in transplant pharmacology, contributing to the development of effective immunosuppressive strategies for Japanese renal transplant patients.

Significant Improvement in Magnetorheological Performance by Controlling Micron Interspaces with High Permeability Submicron Particles.

The shear yield strength, sedimentation stability and zero-field viscosity of magnetorheological fluids (MRFs) are crucial for practical vibration damping applications, yet achieving a balanced combination of these performances remains challenging. Developing MRFs with excellent comprehensive performance is key to advancing smart vibration damping technologies further. Theoretically, incorporating a multiscale particle system and leveraging synergistic effects between their can somewhat enhance MRFs' performance. However, this approach often faces issues such as insignificant increases in shear yield strength and excessive rise in zero-field viscosity. In response, this study employs a DC arc plasma method to synthesize a high magnetic permeability, low coercivity submicron FeNi particles, and further develops a novel CIPs-FeNi bidisperse MRFs. The introduction of submicron FeNi particles not only significantly enhances the shear2019 yield strength of MRFs under low magnetic fields but also promotes improvements in sedimentation stability and redispersibility without excessively increasing viscosity. Comprehensive performance analysis is conducted to explore the optimal content ratio, and detailed mechanisms for the enhancement of performance are elucidated through analysis of parameters such as chain-like structure, magnetic flux density and friction coefficient. Most importantly, the superior comprehensive performance combined with straightforward fabrication methods significantly enhances the engineering applicability of the CIPs-FeNi bidisperse MRFs.

High-density lipoprotein functionality in cholesterol efflux in early childhood is related to the content ratio of triglyceride to cholesterol

Cholesterol efflux capacity (CEC), commonly measured as a useful risk marker of atherosclerotic cardiovascular disease, depends on high-density lipoprotein (HDL) functionality and its concentration. We defined the relative HDL functionality in cholesterol efflux, not influenced by HDL concentration, as the ratio of measured CEC to standardized CEC (stCEC) based on HDL-cholesterol (HDL-C) of each individual using the curve regression equation obtained from the correlation. HDL-C, CEC, and CEC/stCEC levels in the < 28-day-old participants (neonates) were significantly low compared to those of the ≥ 28-day-old participants, indicating that the low CEC levels in the neonates depend on not only lower HDL-C but also lower HDL functionality. The low level of CEC/stCEC was remarkable in neonates born at < 34 weeks of gestation and did not improved to the reference level (1.000) until the infantile period. The relatively low or high CEC/stCEC ratios in neonates and infants were associated with lower or higher HDL-TG and HDL-TG/HDL-C ratio, respectively. However, no apparent effect of HDL-TG and HDL-TG/HDL-C ratio on CEC/stCEC was observed in the ≥ 1-year-old participants, indicating that HDL functionality in cholesterol efflux could be associated with the various HDL particles with various lipid compositions, but not just with HDL-TG and HDL-TG/HDL-C ratio.

Kinetics of moisture exchange during convection drying of thin flat wet materials

The kinetics of convective drying of thin wet thermal insulation materials based on the relative drying rate and relative moisture contents has been studied. Processing of experimental data on drying of various wet materials has established that the relative drying rate is related to the relative moisture contents, which are the ratios of the current moisture content to its critical and initial values. Based on the functional dependence of the relative drying rate on the relative moisture contents using the processing of the experiment on drying of ceramics, felt, and asbestos, equations for calculating the drying time are obtained. The dependence of the relative drying rate on the ratio of the current moisture content to the critical one is given. Zonal methods for calculating the drying time are given, based on the drying rate curve. An expression for determining the drying coefficient is developed. Based on the analysis of experimental data on drying porous ceramics, sheet asbestos, and wool felt, graphs of the dependence of the relative drying rate on the ratio of the current moisture content to the initial one are constructed. Dependencies for determining the critical moisture content of the material are given. The considered method of processing experimental data allows obtaining all the main equations for calculating the kinetics of the drying process. A variant of estimating the drying time based on one experiment with a short time interval is given. A comparison of the calculated values according to the equations with the experiment is performed. The spread of the calculated values is in the range of experimental error. The formulas for calculating the drying time obtained without plotting the drying rate curve allow significantly reducing the time of processing the experimental data and can be applied to other materials.

The characteristics of V, Sc, Cr and Ni within the Cambrian terrigenous-carbonate deposits found in the Syuldyukar kimberlite field (Western Yakutia)

The investigation of the Syuldyukar kimberlite field, located within the Yakut diamond-bearing province, involved approximately 4,000 X-ray fluorescence (XFA) analyses and 150 inductively coupled plasma atomic emission spectroscopy (ICP AES) analyses on the host sedimentary rocks of the Upper Cambrian Holomolokha formation in proximity to the kimberlite bodies. The results indicated a disruption in the correlation ratios when compared to background concentrations, while subclark levels of vanadium (V), scandium (Sc), chromium (Cr), nickel (Ni), and other elements remained consistent. The elements were divided into three categories: typomorphic elements for kimberlites (Cr, Ni, Co), elements associated with carbonatites (barium (Ba), strontium (Sr), neodymium (Nd), zirconium (Zr)), and elements characteristic of basalts (V, Sc, zinc (Zn)). High positive correlation coefficients were established for the specified elements in the background concentrations. However, ICP analyses indicated significant decreases in the correlation between elements from different groups in the near-kimberlite space at the Syuldyukar site. X-ray diffraction (XRD) studies showed that in the compression areas, the correlation ratios of various elements were inconsistent when compared to the stretching areas. The analysis of the XRF and ICP data reveled that the average elemental concentrations in the background and near-tube space were nearly identical, except for some unusual hurricane values, with variations showing only slight changes. The positive correlation of several elements likely reflects background geological processes, including sedimentation in a marine basin and subsequent transformations such as hypergenesis, diagenesis, and catagenesis. The significant decrease in correlation coefficients, even with background concentrations remaining stable, is likely due to the redistribution of elements in the fluid resulting from phreatomagmatic explosions linked to the intrusion of kimberlites. Aqueous chloride fluids were observed to most actively redistribute elements in areas experiencing local tectonic compression. The identified changes in the correlation ratios of background elemental concentrations in sedimentary rocks containing kimberlite could act as a new indicator for locating hidden diamond-bearing kimberlites.

Investigation on oxygen vacancy regulation mechanism of ZnO gas sensors under temperature modulation mode to distinguish alcohol homologue gases

Homologous gases are difficult to be detected due to their similar chemical properties, especially for metal oxide semiconductor gas sensors whose selectivity has always been a significant challenge. Dynamic temperature modulation method with periodically changing operating temperature was used to detect alcohol homologous gases. However, there are still problems with the deviceization of heating control circuits. In this paper, dynamic temperature modulated method which needs a simple heating circuit is used to distinguish alcohol homologous gases in combination with oxygen vacancy modulation of ZnO gas sensors. Ethyl alcohol, n-propyl alcohol, isopropyl alcohol and n-butyl alcohol were measured by ZnO gas sensors with different oxygen vacancies content ratios under rectangular wave with a voltage range of 2–6 V. It was found that the greatest difference among the response curves when the material calcined at 600°C which has the largest oxygen vacancies content ratio. Finally, the recognition of the four homologue gases measured by ZnO-600 sensor was achieved by dynamic time warping and the recognition accuracy is 99.33 %.

Predictive model for shear wave velocity of gravelly soil and its application to liquefaction triggering assessment

Several studies have established empirical correlations between shear wave velocity (Vs) and standard penetration test blow count (SPT-N) for engineering use. However, these empirical correlations cannot be applied to gravel-rich soils since the measured SPT-N is often inflated in gravel. Therefore, an empirical correlation of Vs for gravel is developed in this study using the Engineering Geological Database for the Taiwan Strong Motion Instrumentation Program. The Vs predictive model considers gravel content (GC) and coefficient of uniformity (Cu) in addition to effective vertical stress, void ratio, fines content, plasticity index, and overconsolidation ratio, which have been considered previously. The proposed model indicates that Vs increases with GC and Cu. Moreover, the Vs adjusted for GC can be used with existing Vs -based liquefaction triggering relationships to rationally define the boundary between liquefaction and non-liquefaction case histories with different GCs.

Effect of Co-exposure to Additional Substances on the Bioconcentration of Per(poly)fluoroalkyl Substances: A Meta-Analysis Based on Hydroponic Experimental Evidence.

A consensus has yet to emerge regarding the bioconcentration responses of per(poly)fluoroalkyl substances under co-exposure with other additional substances in aqueous environments. This study employed a meta-analysis to systematically investigate the aforementioned issues on the basis of 1,085 published datasets of indoor hydroponic simulation experiments. A hierarchical meta-analysis model with an embedded variance covariance matrix was constructed to eliminate the non-independence and shared controls of the data. Overall, the co-exposure resulted in a notable reduction in PFAS bioaccumulation (cumulative effect size, CES = - 0.4287, p < 0.05) and bioconcentration factor (R2 = 0.9507, k < 1, b < 0) in hydroponics. In particular, the inhibition of PFAS bioconcentration induced by dissolved organic matter (percentage form of the effect size, ESP = - 48.98%) was more pronounced than that induced by metal ions (ESP = - 35.54%), particulate matter (ESP = - 24.70%) and persistent organic pollutants (ESP = - 18.66%). A lower AS concentration and a lower concentration ratio of ASs to PFASs significantly promote PFAS bioaccumulation (p < 0.05). The bioaccumulation of PFASs with long chains or high fluoride contents tended to be exacerbated in the presence of ASs. Furthermore, the effect on PFAS bioaccumulation was also significantly dependent on the duration of co-exposure (p < 0.05). The findings of this study provide novel insights into the fate and bioconcentration of PFAS in aquatic environments under co-exposure conditions.

Blue energy conversion utilizing smart ionic nanotransistors

The use of concentration gradients across nanofluidic membranes for energy generation presents a novel and sustainable approach to power production. This study investigates the impact of ion nanotransistor configurations on ion transport and energy generation. Two types of cylindrical symmetrical nanotransistors, PNP and NPN, were tested. Using the finite element method, the Poisson-Nernst-Planck and Navier-Stokes equations were solved to evaluate how the configuration of soft layers, concentration ratios, and charge density influence energy output. Results show that the NPN configuration consistently outperforms the PNP setup in energy production, with energy generation ranging from 40pW to 56pW, compared to 35pW to 43pW for the PNP structure, when soft layer charge density increase from 25mol/m3 to 100mol/m3. The superior performance of the NPN arrangement is attributed to its higher electrostatic potential and enhanced ion mobility. These findings underscore the potential of NPN nanotransistor configurations for optimizing energy generation as well as water desalination in nanofluidic systems.

Therapeutic Indices of Topical Antiseptics in Wound Care: A Systematic Review.

Chronic wounds place a heavy burden on healthcare systems and markedly reduce the ability of patients to engage in activities of daily living. One major factor contributing to impaired wound healing is bacterial bioburden. With the rise in antibiotic resistance and the slowdown in antibiotic development pipelines, alternative antimicrobial strategies are important. The objective of this systematic review is to determine the topical antiseptic therapeutic index values for bacterial species commonly isolated from chronic wounds. The therapeutic index is a ratio of the lowest concentration that causes mammalian cell cytotoxicity over the minimum bactericidal concentration. Higher values indicate greater safety and potential clinical benefit. A systematic literature search was performed in Medline and Embase, resulting in the inclusion of 37 articles that reported on the minimum bactericidal concentration in bacterial species commonly isolated from chronic wounds and their cytotoxicity concentrations in mammalian cells. The therapeutic indices for the topical antiseptics included in this study were generally low, with most ranging between 0.5-3.0. The highest therapeutic index values for Escherichia coli (5.49), Staphylococcus aureus (6.31) and Pseudomonas aeruginosa (8.81) were achieved by hypochlorous acid, whereas the highest therapeutic index values for methicillin resistant S aureus (12.1) was achieved by polyhexamethylenebiguanide. Antibiotic stewardship principles may need to be applied to topical antiseptics due to some isolated evidence of topical antiseptic resistance and cross-resistance to antibiotics. The choice of antiseptic should not be made solely based on therapeutic index values, but individualized to the patient, with consideration for the wound healing condition that may include covert infection.

Preparation of a Porous Spherical Adsorbent by Oil-In-Water-In-Oil Emulsion Polymerization for Phycocyanin Adsorption

ABSTRACT Phycocyanin is a protein with potential in food and medical applications. A porous spherical adsorbent was prepared by oil-in-water-in-oil emulsion polymerization. Oil and water phases containing surfactants and monomers, respectively, were emulsified, and the prepared emulsion was added to the oil phase to polymerize the porous spherical adsorbent. The concentration ratio of N,N-dimethylacrylamide and 2-dimethylaminoethylmethacrylate (DMAEMA) in the water phase was changed. The obtained spherical adsorbent had a size of about 150 μm and a water content of 90%, with macropores of several micrometers. Phycocyanin (20 kDa) of Nostoc commune was leached by the freeze and thaw method to prepare the solution. The adsorption data of the batch and column modes were evaluated by ordinary differential and partial differential equations, respectively, considering competitive adsorption, to obtain parameters of the mass transfer coefficient and saturated adsorption capacity. In the b\ sfer coefficient of phycocyanin decreased by about one-third, but the saturated adsorption capacity increased three-fold. In the continuous flow column, leached biomacromolecules other than phycocyanin had greater parameters of mass transfer and capacity. To prepare an adsorbent for the biomacromolecules, selective adsorption sites in the polymer matrix should be designed and prepared.

Quasi-static/dynamic energy absorption characteristics and micromechanical behavior of Al/Ep cast metal braided tubular structures

As a low-density, high-strength material with high energy release potential, Al/Ep cast metal braided tubes have a wide range of application prospects in the combatant shell, which is one of the most important means to realize the integrated destructive effect of kill and blast. In this paper, Al/Ep composites with mass ratios of 3:7, 4:6 and 5:5 were prepared, and the intrinsic model of Al/Ep was established by studying its quasi-static and dynamic mechanical properties. The Al/Ep cast three-dimensional braided metal skeletons were used to obtain the required cast braided tubes with different mass ratios, and the destruction behaviors of the tubes under axial and radial compressive loads were analyzed by a combination of experimental and numerical simulations. The results show that the addition of Al particles can significantly improve the elastic-plastic properties of Al/Ep composites, and the energy storage and absorption capacities are positively correlated with the ratio of the relative contents of Al powder. When the mass ratio of Al powder to epoxy resin is 5:5, the energy absorption of Al/Ep composites is 23.16 MJ/m3, which is optimal among similar specimens and much higher than that of pure epoxy resin materials (the energy absorption of epoxy resin is 9.63 MJ/m3). The strength of binary resin matrix composites is improved, and the intrinsic models of three kinds of different mass ratios of Al/Ep composites are obtained. The intrinsic models of various Al/Ep cast braided tubes with crushing force efficiency CFE, energy absorption capacity, and specific energy absorption SEA decreased with the ratio of mass occupied by the braided filaments.

B-298 Quantitation and Abundance of Xylazine and Xylazine Metabolites in Human Urine by LC-MS/MS

Abstract Background The most common cause of drug overdose fatality in the US involves synthetic opioids such as fentanyl. Recently the Director of the White House Office of National Drug Control Policy designated fentanyl associated with xylazine as an emerging threat to the US, and a national response plan will include xylazine testing. Xylazine, a clonidine analog is not FDA-approved for use in humans but has been increasingly detected in unregulated illicit drugs supplies. Our understanding of xylazine detection, metabolism, and clinical impact on patients, however, is limited. The objectives of this study are to develop a liquid chromatography tandem mass spectrometry (LC-MS/MS) method to investigate the presence and abundance of xylazine metabolites in remnant urine samples submitted for clinical testing. Methods Remnant urine samples were identified when tested positive for xylazine during routine clinical LC-MS/MS testing. All experiments were performed using an Acquity HPLC coupled to a Waters TQS-micro triple quadrupole mass spectrometer. Urines were diluted with xylazine-D6 internal standard, hydrolyzed using β-glucuronidase and separated on a 100mm x 2.1mm, 2.6μm Kinetex C18 column (Phenomenex) with a 4 minute step gradient from 2% to 98% mobile phase B (0.1% formic acid and 2mM ammonium acetate in A: water; B: methanol) with a flow rate of 400 μl/min at 50°C. Xylazine and 4-OH-xylazine were detected in positive mode using multiple reaction monitoring, with transitions optimized from standards (Cayman Chemical and/or Sigma Aldrich), resulting in the following transitions: xylazine: 221&amp;gt;90, 221&amp;gt;164; 4-OH xylazine: 237&amp;gt;90, 237&amp;gt;137. Xylazine and 4-OH-xylazine were quantified using calibration curves prepared from 1 - 5,000 ng/mL in negative urine. Product ion scanning (PIS) was used to detect four additional xylazine metabolites, based on spectral matching to previously published full scan high resolution product ion spectra. The highest abundance fragment ions and identified retention times from PIS experiments were used to perform targeted detection for sulfone-xylazine (253&amp;gt;181, 253&amp;gt;147), oxo-xylazine (235&amp;gt;122, 235&amp;gt;114), OH-sulfone-xylazine (269&amp;gt;197, 269&amp;gt;163), and OH-oxo-xylazine (251&amp;gt;197, 251&amp;gt;148). Results Xylazine was detected at &amp;gt;=1 ng/mL in 38% (54/138) of fentanyl positive urines. A subset (n= 362) of urines that screened positive for opiates, amphetamines, or cocaine metabolite, were also tested but xylazine was detected in only 1 urine that did not contain fentanyl.Xylazine concentrations quantified in 61 remnant urines ranged from &amp;lt;1 to &amp;gt;5,000 ng/mL. 4-OH-xylazine concentrations ranged from &amp;lt;1 to 509 ng/mL. We observed five previously reported xylazine metabolites: 4-OH-xylazine, oxo-xylazine, sulfone-xylazine, OH-oxo-xylazine, OH-sulfone-xylazine. The mean concentration ratio of 4-OH-xylazine-to-xylazine was 0.11. The mean peak area ratios (metabolite-to-xylazine) for sulfone-xylazine, OH-oxo-xylazine, OH-sulfone-xylazine, and oxo-xylazine were 3.5, 3.8, 2.1, and &amp;lt;0.1, respectively. The proposed sulfone-xylazine and OH-oxo-xylazine metabolites were observed to have the most abundant signal of all detected metabolites, although there is currently no commercially available standard to facilitate quantification. Conclusions Xylazine and 4-OH-xylazine were quantitated in 61 patient urines. Four additional xylazine metabolites were observed and relative abundance to xylazine was estimated using peak areas. Future studies include quantitation of xylazine and xylazine metabolites in plasma and association of xylazine detection with clinical presentation and patient outcomes.

Optimizing Sugarcane Clonal Propagation In Vitro by Using Calcium Ammonium Nitrate and Ammonium Sulfate.

To replace explosive nitrate-based chemicals in MS medium, this study developed a new, safer, and more cost-effective method using fertilizer-grade calcium ammonium nitrate and ammonium sulfate. This approach replaces ammonium nitrate and potassium nitrate, ensuring both safety and cost efficiency for sugarcane propagation. Six local sugarcane varieties-Zhongtang1 (ZT1), Zhongtang3 (ZT3), Zhongtang6 (ZT6), Guitang42 (GT42), Guitang44 (GT44), and Guiliu 07150 (GT07150)-were used. In the control group (Ck), nitrate ions (NO3-) were 39.28 mM, and ammonium ions (NH4+) were 20.49 mM, with a 2:1 ratio. In the treatment groups, the concentrations of nitrate ions (NO3-) and ammonium ions (NH4+) included treatment 1 (19.69 mM NO3- and 10.3 mM NH4+), treatment 2 (29.54 mM and 15.44 mM), treatment 3 (39.38 mM and 20.59 mM), treatment 4 (49.225 mM and 25.74 mM), treatment 5 (59.07 mM and 30.89 mM), and treatment 6 (68.915 mM and 36.03 mM), respectively, all with the same 2:1 ratio. Fifty bottles per treatment, with three replicates, were used for each sugarcane plantlets treatment. After five subcultures, the optimal ratio was determined by assessing morphological and physiological parameters, nitrogen levels, and SOD enzyme activity. The results indicated that treatment 3 (39.38 mM and 20.59 mM) and treatment 4 (49.225 mM and 25.74 mM) had the best morphological and physiological indicators. The optimal doses of calcium ammonium nitrate and ammonium sulfate were found in treatments 3 and 4, as well as in the control, with no significant difference among them. However, treatment 3, due to its lower dose, was more cost effective. To improve cost efficiency in practical production, it is recommended to use the lower concentration ratio of treatment 3 for plant tissue culture plantlets.

Modelling П-Shaped Concentrating Optics for Lcpv Solar Cells Using Fresnel Lens

Abstract Most concentrating optics do not show good performance at higher incidence angles and have low acceptance angles and, therefore, they require a high-accuracy solar tracking system, which is costly. In this study, by detailed investigation of optics of the proposed П-shaped concentrating optics, it was found that system remained high in terms of optical efficiency and its concentration ratio at certain higher incidence angles. During the work, ray path through the concentrating optics, width of the light spot at different incidence angles were calculated. Optical efficiency, geometrical concentration ratio, concentration ratio at different incidence angles were found by the results of COMSOL Multiphysics calculations. It was found that the system had a high optical efficiency of approximately 95% and its concentration ratio of 3x-5x was at the range of ±0-20 degrees of incidence angle, and it could reduce the work of a solar tracking system. As well, an increase in the optical efficiency could be seen from 0 to 5 degrees of the incidence angle and an increase in the concentration ratio could be seen from 0 to 12 degrees of the incidence angle in terms of the reflective mirrors which helped redirect the rays to the solar cells. Optical systems with such a high incidence angle could reduce the performance of the solar tracker system, and it reduced the overall cost and energy consumption of the LCPV.

Enhancing thermoelectric generation: Integrating passive radiative cooling and concentrated solar heating with consideration of parasitic heat conduction

Thermoelectric generators (TEGs) integrated with solar energy and radiative cooling offer a promising approach for generating power. Concentrated solar energy enhances generation by increasing the solar flux density. However, the relationship between thermoelectric generation and concentration ratio remains not well understood. In this study, the finite element method is employed to investigate the temperature difference across TEGs and the change in generation performance with varying concentration ratios. The results show that due to the mismatch among cooling, heating, and parasitic heat conduction powers, the optimal power generation does not occur at the maximum concentration ratio. As the concentration ratio increases, the temperature difference across the single TEG and its output power initially increase and then decrease. To further improve the power generation performance at high concentration ratios, this study introduces TEG stacking strategy to enhance waste heat recovery by increasing thermal resistance. Outdoor experiments with self-made solar absorptive coating and radiative cooling coating validate this approach, achieving a temperature difference of 64.17 °C and a power density of 135.57 W m−2 by stacking three TEGs, outperforming a single TEG by over three times. This study offers a potential method to continuously power remote off-grid communities and low-power devices.

CRDS‐based measurement of CO/CO2 concentration ratios for assessing transformer insulation aging

AbstractA gas analyzer has been developed using cavity ring‐down spectroscopy (CRDS) technology, designed to simultaneously measure the concentrations of CO2 and CO. These gases are critical indicators of transformer insulation degradation. The analyzer covers a CO2 concentration range from a few ppm to several thousand ppm and can measure CO/CO2 concentration ratios from 0.076 to 0.8. The selected absorption lines for CO and CO2 are centered at 6337.99 and 6338.59 cm−1, respectively. The two candidate lines are proximate to each other and nonoverlapping. The experimental results indicate that the system accurately fits the measured and calculated signals, enabling concentration measurements at the ppm level. This confirms its ability to measure the gas concentrations and ratios critical for assessing the condition of transformer insulation. This CRDS‐based system offers a reliable and sensitive method for early detection of potential transformer faults.

Comparative study of Maillard reaction and blending between soybean protein isolate and soluble soybean polysaccharide: Physicochemical, structure and functional properties

Soybean protein isolate-soluble soybean polysaccharide (SPI-SSPS) complexes and mixtures with varying SPI/SSPS concentration ratios (1: 1, 2:1, 4:1, 8:1) were prepared by Maillard reaction and blending, respectively, and their physicochemical, structure, and functional properties were compared studied. The physical stability of SPI-SSPS complex, which consisted of CN and CS bonds, was better than that of the SPI/SSPS mixture with electrostatic interactions and hydrogen bonds, and both were superior SPI alone. The complex with SPI/SSPS concentration ratio of 8:1 had the highest grafting degree (33.25 %) and a more ordered structure, making its solubility and emulsifying property lower than the SPI/SSPS mixture; however, the physical and thermal stability of the SPI-SSPS complex was higher than that of the SPI and SPI/SSPS mixture. In particular, the SPI-SSPS complex with a high grafting degree showed a higher thermal denaturation temperature (194.06 °C). This study aimed to provide effective modification methods to utilize soybean processing by-products by modifying soybean protein isolate with soluble soybean polysaccharide.

Delivery of imiquimod to intestinal lymph nodes following oral administration

Intestinal lymph nodes are involved in the progression of colorectal cancer (CRC). Tumours suppress the activation of dendritic cells (DCs) in draining lymph nodes, diminishing anti-cancer immune response. Imiquimod (IMQ) facilitates DCs activation via toll-like receptor 7, suggesting that targeted delivery of IMQ to intestinal lymph nodes can improve the treatment of CRC. This study aims to enhance the delivery of IMQ to intestinal lymph nodes by a highly lipophilic prodrug approach. Amide prodrugs were synthesised by conjugating IMQ with saturated and unsaturated medium- to long-chain fatty acids. Their potential for intestinal lymphatic transport was assessed by their affinity to chylomicrons and solubility in long-chain triglycerides. Further selection of prodrug candidates was determined by resistance to enzymatic hydrolysis in intestinal lumen and release of IMQ in the lymphatics using fasting state simulated intestinal fluid supplemented with esterases, brush border enzyme vesicles and plasma. Key pharmacokinetic parameters and biodistribution in rats were assessed for the most promising compounds, prodrugs 5 and 8. The plasma concentration–time profile of IMQ following oral administration of the prodrugs was less erratic in comparison to the administration of unmodified IMQ. The lymph-to-plasma ratios of IMQ concentration increased 1.9- and 1.7-fold using prodrugs 5 and 8 in comparison to administration of unmodified IMQ, respectively. Importantly, the average concentration of IMQ in mesenteric lymph nodes (MLN) was 11.2- and 7.6-fold higher than in plasma following the administration of prodrugs 5 and 8, respectively. Additionally, the non-specific wide distribution of IMQ into various organs and tissues was reduced with prodrugs. This work suggests that the highly lipophilic prodrug approach can efficiently deliver IMQ to intestinal lymphatics. In addition, this study demonstrates the feasibility of an amide prodrug approach for intestinal lymphatic targeting.

Theoretical and experimental studies on the electrochemical behavior of steel in HCl solution in the presence of two bio-inhibitor mixtures

In this new study, the inhibitory effectiveness of two bio-inhibitor mixtures has been studied on the corrosion characteristics of carbon steel in an HCl environment. The inhibitors were derived from a plant seed (quinoa seed-QS) and an insect extract (Oestrus ovis larvae-OOL). The total inhibitor concentration was a variable factor even the ratio of bio-inhibitor concentration was a fixed parameter. The electrochemical behavior of steel substrate was investigated through the Tafel polarization and electrochemical impedance spectroscopy measurements. Fourier transform infrared spectroscopy and field emission scanning electron microscopy were performed to identify bonds and analyze the morphology of the corroded surface of the steel. Additionally, molecular dynamics (MD) simulation and quantum calculations were applied to investigate the inhibitory influence of utilized bio-inhibitors. The experimental results indicated that the corrosion resistance decreased to 85 % when the optimum total concentration of the bio-inhibitor was 1 g L−1. The Langmuir model was used to illustrate the adsorption mechanism on the steel surface when physical adsorption occurred. Quantum chemical calculations revealed that the QS-inhibitor adsorbed more effectively onto the metal surface than the OOLE-inhibitor, due in part to a lower energy gap and higher HOMO energy. MD simulation and Monte Carlo calculations further confirmed that the QS-inhibitor was adsorbed on the Fe (110) surface with higher adsorption energy than the OOLE-inhibitor.