Concentration Range Research Articles

Cu-Ag nanoparticles-dispersed and microchannel textured-laser induced graphene: A chemiresistive aptasensor for thrombin

Thrombin is a key enzyme of the clotting cascade, which can convert soluble fibrinogen to insoluble fibrin. A rapid and accurate sensor is required to give easy access to patients and healthy individuals to monitor their thrombin levels. In this study, a Cu and Ag bimetal nanoparticles (NPs)-dispersed and microchannel textured-laser induced graphene (Cu-Ag-LIG)-based chemiresistive aptasensor is developed. The sensor substrate was synthesized via the suspension polymerization of phenol and formaldehyde, with the in situ inclusion of the metal salts in the reaction mixture. Laser ablation converted the carbon containing polymeric groups to sp2 hybridized graphitic carbon and the metal salts to zero-valent metal NPs. Laser ablation was also used to create microchannels on the graphene surface to ensure the uniform distribution of the analyte. Ag NPs facilitated the binding of thrombin binding aptamer (TBA) via covalent bond, while Cu NPs provided structural support. The aptasensor showed a linear response over the 0.1–50 units/mL-thrombin concentration range. The sensor response was unaffected by common interfering biomolecules such as glucose, bovine serum albumin, urea, trypsin, and cholesterol. This study showcases the broader and often overlooked significance of chemiresistive sensors not only in healthcare but also across various scientific domains, offering avenues for transformative advancements in diagnostic technologies.

Impact of patient habitus and acquisition protocol on iodine quantification in dual-source photon-counting computed tomography.

Evaluation of iodine quantification accuracy with varying iterative reconstruction level, patient habitus, and acquisition mode on a first-generation dual-source photon-counting computed tomography (PCCT) system. A multi-energy CT phantom with and without its extension ring equipped with various iodine inserts (0.2 to 15.0mg/ml) was scanned over a range of radiation dose levels ( 0.5 to 15.0mGy) using two tube voltages (120, 140kVp) and two different source modes (single-, dual-source). To assess the agreement between nominal and measured iodine concentrations, iodine density maps at different iterative reconstruction levels were utilized to calculate root mean square error (RMSE) and generate Bland-Altman plots by grouping radiation dose levels (ultra-low: ; low: 1.5 to 5; medium: 5 to 15mGy) and iodine concentrations (low: ; high: 5 to 15mg/mL). Overall, quantification of iodine concentrations was accurate and reliable even at ultra-low radiation dose levels. RMSE ranged from 0.25 to 0.37, 0.20 to 0.38, and 0.25 to 0.37mg/ml for ultra-low, low, and medium radiation dose levels, respectively. Similarly, RMSE was stable at 0.31, 0.28, 0.33, and 0.30mg/ml for tube voltage and source mode combinations. Ultimately, the accuracy of iodine quantification was higher for the phantom without an extension ring (RMSE 0.21mg/mL) and did not vary across different levels of iterative reconstruction. The first-generation PCCT allows for accurate iodine quantification over a wide range of iodine concentrations and radiation dose levels. Stable accuracy across iterative reconstruction levels may allow further radiation exposure reductions without affecting quantitative results.

High-performance ammonia sensor based on cobalt porphyrin-polyaniline polymer

Aiming at the problems of low sensitivity, poor selectivity and poor stability of traditional ammonia (NH3) sensors, a novel preparation strategy for NH3 sensors was proposed in this study. The polymer material cobalt porphyrin-polyaniline (TAPPCo-PANI, TC-P) was prepared by adding TAPPCo during the polymerisation of aniline, and the TC-P NH3 sensor was constructed by drop-coating the TC-P on the PET-based interdigital electrode. The TC-P sensor was tested for NH3 sensing, and the results showed that it had a fast response time (108 s) to NH3, and the TC-P sensor response values showed a linear correlation in the range of NH3 concentrations between 50 and 500 ppm. In addition, the TC-P sensor has high sensitivity, strong selectivity and good stability. The addition of TAPPCo accelerates the electron transfer rate, which gives the sensor excellent gas-sensitive performance. Therefore, TC-P is expected to be a reliable NH3 sensor material.

Passive RFID integrated sensors based on ZnO/CuO/RGO and SnO2/CuS/RGO nanomaterials are used for CO2 and ethanol detection in fruit and vegetable storage and transportation

This article proposes and designs a passive RFID integrated dual parameter gas sensor that can respond to ethanol and carbon dioxide gases at room temperature. Firstly, nanocomposite sensitive materials were prepared by hydrothermal method, and their microstructure and elemental composition were analyzed through TEM, SEM, XRD, XPS and UPS characterization tests. The dual frequency gas sensing antenna was designed and optimized using HFSS software, and a high-precision engraving mechanism was used to prepare the sensor model. Finally, two different gas sensitive materials were deposited on the corresponding positions of the symmetric structure of the sensing antenna, and the different gas concentration changes were converted into amplitude and frequency changes at different frequency points of the sensing antenna. The test results showed that the sensor operates within the range of carbon dioxide concentration of 600ppm∼1600ppm, with an amplitude change of 10.3dB and a sensitivity of 0.009dB/ppm. The sensitivity of the sensor is 0.29MHz/ppm when operating stably within the ethanol concentration range of 200ppm∼2800ppm. Compared with traditional gas sensors, passive RFID dual parameter gas sensors have the advantages of selective response to carbon dioxide and ethanol gases in mixed gas environments, fast response speed, strong anti-interference to interfering gases, and strong temperature adaptability. It has a good application prospect transportation, agricultural greenhouses, and food testing.

Analysis of the CO2 + C2Cl4 mixture in high temperature heat pumps: Experimental thermal stability, liquid densities and cycle simulations

Transcritical heat pumps working with CO2-based mixtures with a low-volatility dopant are found to achieve good performances in thermally integrated heat pumps, especially when sensible heat sources and heat sinks are considered. This paper introduces in literature tetrachloroethylene, C2Cl4, as CO2-dopant for the mixture to be adopted as working fluid in high temperature heat pumps. To calibrate the thermodynamic model used in the cycle simulations, an experimental characterization on the mixture is proposed: liquid densities of the mixtures are measured, in a wide range of concentration, optimizing the binary interaction parameter of the Peng Robinson equation of state. Moreover, the thermal stability of pure C2Cl4 is experimentally evaluated, identifying the maximum allowable compressor outlet temperature between 200 °C and 250 °C, with a decomposition rate below 1 %/year if the fluid is kept at temperatures around 200 °C. Then, the potentialities of this very high temperature heat pump are assessed in spray dryer applications: a coefficient of performance around 3.38 is obtained for a conventional spray dryer plant, corresponding to 73 % of second law efficiency, considering an air flow heated from ambient temperature to 200 °C as the sink, while cooling the sensible heat source, available at 76 °C, below 30 °C. As term of comparison, the same system adopting propane, instead of the CO2 + C2Cl4 mixture, would achieve a coefficient of performance and second law efficiency of 2.94 and 64 %, respectively.

A novel label free electrochemical aptasensor based on poly(anthranilic acid-Co-aniline) for detection of miRNA-155, a cancer biomarker

Traditional electrochemical biosensors often rely on expensive materials like gold nanoparticles within their electrode structures. In contrast to existing methods, this research introduces a novel, groundbreaking, label-free aptasensor. This sensor comprises simple and inexpensive materials, making it accessible and budget-conscious. It boasts exceptional sensitivity, allowing for the identification of leukemia cancer biomarker (miRNA-155) in its early stages. The proposed aptasensor consisted of a copolymer of poly anthranilic acid and polyaniline on the graphite sheet, in which the receptor of miRNA-155 was self-assembled on the copolymer. The substrate of receptors has benefits, including high electrical conductivity, excellent stability, good biocompatibility, and simple synthesis. The important variables affecting the adequacy of the designed aptasensor were examined in the presence of [Fe(CN)6]3-/4- as a redox probe. The proposed aptasensor was successfully used in human blood plasma. Due to the ease of preparation, cost, and time effectiveness, the proposed aptasensor is promising for mass production. Finally, at optimum conditions, the sensor exhibited a linear response within a concentration range of 0.1nM to 1 aM with a detection limit of 1 aM.

Phase I Dose Volume Escalation of Rectally Administered PC-1005 to Assess Safety, Pharmacokinetics, and Antiviral Pharmacodynamics as a Multipurpose Prevention Technology (MTN-037)

Background: On demand, topical PrEP is desired by those preferring episodic, nonsystemic PrEP. PC-1005 gel (MIV-150, zinc, and carrageenan) exhibits in vitro antiviral HIV-1, human papillomavirus (HPV), and herpes simplex virus type 2 (HSV-2) activity, attractive for a multipurpose prevention technology candidate. We evaluated the safety, pharmacokinetics, and antiviral effect of rectally applied PC-1005. Methods: HIV-uninfected adults received a series of 3 rectal PC-1005 doses—4, 16, and 32 mL separated by 2-week washout periods. Following each dose, plasma, rectal fluid and tissue, and vaginal fluid were collected over 48 hours. Results: Thirteen adults enrolled; 12 completed all 3 doses. All 13 adverse events reported were grade 1 or 2; 5 were judged study drug related. Plasma MIV-150 peaked 1–2 h after dosing with a median peak concentrations range of 0.07–0.23 ng/mL and median half-life range of 4.9–7.4 hours across dose volumes; median concentrations were below assay quantitation limits (BLQ) 24 hours after dosing. Rectal tissue MIV-150 peaked 0.5–1 hours after dosing at 1.4 ng/g (ng/mL) (0.8, 1.9), 46.0 (30.7, 831.0), and 79.7 (11.9, 116.0), respectively, after each dose volume; median tissue concentrations were BLQ beyond 5 hours for all doses. All vaginal fluid samples were BLQ. Ex vivo antiviral assays showed 5 hours of antiviral HPV and HSV effects but no anti-HIV activity. Conclusions: MIV-150 rectal tissue concentrations were below the 100 ng/g target concentration and transient. Ex vivo assays demonstrated antiviral HSV and HPV effects but not against HIV. PC-1005 requires a more potent antiviral and longer-lasting formulation for further consideration as a multipurpose prevention technology candidate. Clinical Trials: NCT03408899.

Preparation, characterization, stability, and antioxidant of quercetin-loaded hyaluronic acid complexes via pH-induced co-assembly

The purpose of this study was to investigate the feasibility of constructing an oral delivery system for quercetin (QUT) using hyaluronic acid (HA) as the wall material. The findings revealed that when the mass ratio of QUT to HA was 1:10, the prepared QUT-HA complexes exhibited excellent stability (particle size of 802 nm, zeta potential of -36 mV) and QUT loading capacity (encapsulation efficiency of 79.77%, loading capacity of 89.65 mg/g). The characterization of QUT-HA complex confirmed the formation of hydrogen bond between QUT and HA, resulting in a homogeneously dispersed coral-like complex and leading to the transformation of QUT's crystal structure into an amorphous state. Environmental stability analysis demonstrated that the QUT-HA complex maintains good stability within an ionic concentration range of 0-500 mM, a pH range of 3-8, and at temperatures of 50-90°C. In vitro simulations of gastrointestinal digestion indicated that the QUT-HA complex aggregates during simulated gastric fluid digestion and dissociates following simulated intestinal fluid digestion, effectively enhancing the bioaccessibility of QUT. Antioxidant assays showed that the scavenging ability of QUT against DPPH and ABTS radicals was significantly improved by complex loading. Therefore, the QUT-HA complex developed in this study possesses a high QUT loading capacity, excellent processing and digestive stability, and can effectively enhance the bioaccessibility and antioxidant activity of QUT, making it a promising candidate for use as an oral nutritional supplement in the field of functional foods.

Microwave-aided sensitive and eco-friendly HPTLC method for estimation of mirabegron using NBD-Cl as bio-sensing fluorescent probe by Integration of principal component Analysis, response surface modelling and white analytical chemistry approach

A large number of analytical methods have been used in in-vivo pharmacokinetic investigations and assays of mirabegron, which is used to treat overactive bladder. Because mirabegron does not give fluorescence, there is no known chromatographic method that uses this property in conjunction with environmentally safe solvents. In order to develop and assess analytical procedures that are precise, sensitive, environmentally friendly, economical, and easy to use, white analytical chemistry was recently presented. Hence, a microwave-aided HPTLC method with fluorescence detection was developed and applied for mirabegron quantification; this method is both sensitive and environmentally acceptable, and it makes use of NBD-Cl, a bio-sensing fluorescent-probe. The analytical-QbD approach, which includes chemometric and response-surface modeling concepts, was used to design this targeted chromatographic method. Critical method variables and performance parameters were identified and optimized using principal component analysis and Box-Behnken design. The targeted method was used to estimate mirabegron through the development of method operable design range navigation and control strategy. A mobile phase consisting of ethyl-acetate and ethanol (8.0 + 2.0, v/v) was used to develop the chromatogram of NBD-Cl derivatised-mirabegron into 8.0 mm bands on a TLC-plate that was supported with aluminum and precoated with silica-gel G60 F254. In a mirabegron concentration range of 50–250 ng/band, the suggested method exhibited linearity. Results showed that the suggested method has a recovery rate of 98 % to 102 %. When estimating mirabegron, the %RSD for the precision and robustness study was determined to be less than 2.0. The mirabegron %assay in the commercially available formulations was determined to be between 98 % and 102 % of the labelled claimed value. Mirabegron had a limit of detection of 10 pg/band and a limit of quantification of 50 pg/band. Marketed tablet formulations of mirabegron had a maximum plasma concentration of 71.58 ng/mL in rats. Using metrics from green analytical chemistry and the RGB model scoring system, we compared the whiteness and greenness profiles of the published and suggested methods. The suggested method was found to be sensitive, eco-friendly, quick, cost-effective, and easy to use for estimation of mirabegron.

Synchronization of extraction and chromatographic conditions of diverse physicochemical behavior of pseudoephedrine, loratadine and desloratadine for their simultaneous determination in human plasma: Application to pharmacokinetic study

A selective, sensitive, and rapid LC-MS/MS method has been developed, optimized, and validated for the simultaneous determination of pseudoephedrine (PSE), loratadine (LOR), and LOR active metabolite, desloratadine (DES) in K3EDTA human plasma. A simple liquid–liquid extraction method was adopted for extraction of the 3 analytes and their internal standards; chlorpheniramine (CLP), loratadine D4 (LOR-D4), and desloratadine D4 (DES-D4), respectively, giving consistent recovery results (78.38––88.23 %) using diethyl ether: dichloromethane (80:20, v/v) as the extraction solvent. The chromatographic separation was challenging due to the polarity differences between PES, which is more polar, and LOR and DES, which are less polar that affected their physicochemical properties including the retention of the drugs on C18 column. The separation was achieved using of isocratic elution of 20 mM ammonium formate and 2 mM trifluoracetic acid ammonium salt: acetonitrile containing 0.15 % formic acid (12:88, v/v) as a mobile phase pumped onto a Supelco Discovery® C18 (4.6 mm x 100 mm, 5 µm) at 35 °C with a flow rate of 0.8 mL/min. The use of trifluoracetic acid ammonium salt as an ion pair reagent in the selected mobile phase allowed good retention of the polar PSE on the used C18 column with a reasonable retention time. Positive Electrospray ionization was employed followed by detection using a tandem mass spectrometer in multiple reactions monitoring (MRM) mode. The sample analysis of this study was conducted in compliance with ICH guideline M10 on bioanalytical method validation and study sample analysis. The method was linear over the concentration range of (4–1200) ng/mL for PSE, (50–15000) pg/mL for both LOR, and DES. The developed method was accurate (91.14–110.30 %), precise (0.53–7.86 %), and was applied to study the pharmacokinetic profile of the cited drugs in the plasma of healthy human volunteers after single oral administration of the fixed-dose combination Claritin D® tablet, (240/10 mg) of PSE, and LOR, respectively.

Integration of bifunctional silver dendrite membranes with surface-enhanced Raman scattering for sensitive detection of polystyrene microplastics in aquatic environments

Microplastics (MPs) are emerging environmental pollutants that are present in aquatic environments and accumulate within the food chain, posing significant threats to human health. Over 8 million tons of MPs enter these ecosystems annually. However, existing rapid qualitative and quantitative analytical methods for trace MPs are limited, hindering comprehensive research on their impact in water environments. This study presents a novel composite membrane with both adsorption and filtration functions, integrated with surface enhanced-Raman scattering technology for detecting trace MPs in water. The silver dendrites, modified with n-hexanethiol and loaded onto filter paper, facilitate enhanced enrichment and simultaneous sensitive detection of MPs. The composite membrane exhibited excellent retention rates for standard polystyrene (PS) MPs of various sizes (200, 500, and 1000nm), achieving high enrichment efficiency. Sensitive detection was realized with a linear response in a concentration range of 0.01 to 0.5g/L, yielding optimal enhancement factors exceeding 2.92×103, enabling detection at μg/L levels. Recovery rates for PS in spiked environmental water samples ranged from 96.86% to 102.96%. This innovative method offers a promising approach for the rapid and sensitive detection of trace MPs in aquatic environments, contributing significantly to the assessment of MPs pollution.

Antiphytopathogenic Diphenyl Ethers from the Marine-derived Fungus Aspergillus sydowii

Background: Natural products from the marine-derived Aspergillus sp. have great potential in agricultural usage due to their broad biological activities. Objective: This study was designed to investigate the antiphytopathogenic compounds from marinederived fungus Aspergillus sydowii LW09. Methods: The compounds were isolated and purified by chromatography methods, and their structures were elucidated by analysis of the NMR and MS spectroscopic data as well as comparison with those of literature. All compounds were evaluated for antibacterial activities against phytopathogenic bacteria Pseudomonas syringae and Ralstonia solanacarum, along with spore germination inhibition of phytopathogenic fungi Fusarium oxysporum and Alternaria alternata. Results: Two diphenyl ethers violaceols I (1) and II (2), along with two alkaloids acremolin (3) and WIN 64821 (4) were isolated from the fermentation extracts of A. sydowii LW09. Compound 1 showed significant antibacterial activity against P. syringae and R. solanacarum with the same MIC values of 4 μg/mL, while compound 2 showed obvious antibacterial activity against P. syringae and R. solanacarum with MIC values of 2 and 1 μg/mL, respectively. Moreover, both 1 and 2 could inhibit the spore germination of F. oxysporum in the concentration range of 64–128 μg/mL. In addition, violaceol I (1) also inhibited the spore germination of A. alternata at 128 μg/mL. Conclusion: This study provided the potential antiphytopathogenic drug candidate for further studies.

Population pharmacokinetic analysis of sirolimus in Japanese pediatric and adult subjects receiving tablet or granule formulations

A population pharmacokinetic (PopPK) analysis was conducted using data from 215 Japanese administered oral sirolimus (tablet and granule) including healthy subjects and patients with intractable vascular anomalies and other diseases. The analysis included neonates, infants, and adults, and identified covariates that influence sirolimus pharmacokinetics (PK). The final model was used to predict sirolimus trough concentrations for various dosing regimens and covariates of interest. The results showed that sirolimus trough concentrations were predicted to increase with higher levels of hemoglobin, and that the granule formulation had a 1.23-fold higher exposure than the tablet formulation. Coadministration of CYP3A4 inducers was found to decrease trough concentrations by 54%. The PK simulations showed that administration of the granule formulation at doses of 0.02, 0.04, 0.06, and 0.08 mg/kg/day in ages <3 months, 3 to <6 months, 6 to <12 months, and ≥1 year, respectively, resulted in >70% target attainment within the therapeutic trough concentration range (5-15 ng/mL). In conclusion, incorporation of time-varying covariates (body weight and age) into the PopPK model appropriately predicted sirolimus concentrations in Japanese subjects from infants to adult sub-populations. This PopPK model would therefore be able to provide a reference for clinical individualization of sirolimus dosing.

Construction of a N-CDs/AuNCs@ZIF-8-assisted ratiometric fluorescent nanosensor for glyphosate detection in edible and medicinal malt

Glyphosate (Gly) is a widely-used herbicide in food production, while, the residue of which due to the long-term and excessive overspray poses serious threats to public health. The development of reliable methods for its sensitive detection is of great urgency. In this study, a novel ratiometric fluorescent nanosensor by encapsulating N-doped carbon dots (N-CDs) and gold nanoclusters (AuNCs) in zeolitic imidazole framework-8 (ZIF-8) as the dual-emissive fluorescence probes at 410 and 650 nm, respectively, was constructed for Gly detection. Due to the adsorption property of ZIF-8, the N-CDs/AuNCs@ZIF-8 nanoprobes accumulated Cu2+ to quench the red fluorescence of AuNCs, and the blue fluorescence of N-CDs was stable. While thiocholine, a product of acetylthiocholine, hydrolyzed by acetylcholinesterase could coordinate with Cu2+, resulting in significant fluorescence recovery of AuNCs. This phenomenon was utilized for the quantitation of Gly, due to its inhibitory effect on acetylcholinesterase activity. By calculating the fluorescence intensity ratio (I650/I410), Gly in real sample could be accurately determined in a concentration range of 2–100 ng/mL with a limit of detection of 1.92 ng/mL because of the anti-interference and the self-correction ability of the two fluorescence signals. The N-CDs/AuNCs@ZIF-8 nanoprobes-assisted ratiometric fluorescent nanosensor exhibited unique merits of rapid construction, simple operation, high specificity, and good accuracy for Gly in edible and medicinal malt samples with recoveries of 93.7–108.2 %. This study presents a multiple tool for the versatile sensing of trace pesticides in more food matrices, which can be extended to a full range of environmental and food safety applications.

Ultrasensitive electrochemical detection of miDNA-21 in human serum based on synergistic signal amplification by conducting polymers and bimetallic nanoparticles

MicroRNA-21 (miRNA-21) is a class of small non-coding RNAs that play a crucial role in the regulation of post-transcriptional gene expression. By leveraging the principle of base complementary pairing, the detection of miRNA-21 can be achieved through its analogue, MicroDNA-21 (miDNA-21), which possesses an identical sequence. Utilizing screen-printed carbon electrodes (SPCE), a conducting polymer (polypyrrole, Ppy), and metal nanocomposites (gold-platinum nanoparticles, Au@Pt NPs) were sequentially electrodeposited to create an electrochemical biosensor for the detection of miDNA-21. This biosensor employed ferrocyanide/ferricyanide (Fe(CN)63−/4−) as the electrochemical signaling probe, and its structure was elucidated via field emission scanning electron microscopy (FESEM) and Energy Dispersive Spectrometer (EDS). Quantitative detection was facilitated through differential pulse voltammetry (DPV), yielding a concentration range and linear fitting equation of 10.00–7.00 × 10.00−14 mol/L: ΔI = 0.5143 lgc + 9.191, R2 = 0.9986. The limit of detection (LOD) was determined to be 2.90 × 10−15 mol/L, with a sensitivity of 9.42 μA/μmol/L·cm2. Subsequent performance assessments confirmed the sensor’s excellent selectivity, reproducibility, and stability. Evaluation using the standard addition method, with normal human serum as the matrix, yielded recoveries ranging from 98.97 % to 102.70 %, and relative standard deviation (RSD) values below 1.00 %. These results demonstrate the method’s viability for practical application in detecting miRNA in human serum.

Green RP-HPLC method for simultaneous quantification of epigallocatechin-3-gallate and rosmarinic acid in lipid-based nanocarriers and biological fluids: Quality by Design-driven optimization and lean six sigma approach

This study presents the development and validation of a reverse-phase high-performance liquid chromatography (RP-HPLC) method for concurrent quantification of EGCG and RA in prepared lipid-based nanocarriers and biological fluids using a QbD approach, greenness assessment, and Six-Sigma methodology. Initially, variations in critical analytical attributes were identified using the Ishikawa fishbone diagram and Risk Priority Number scores. A Taguchi Orthogonal Array design was employed to screen the critical method parameters influencing method development. Systematic optimization of the RP-HPLC method was subsequently achieved using a Box-Behnken design, with the % organic phase, flow rate, and column temperature as the variables. The responses were retention time, tailing factor, and theoretical plates for both EGCG and RA. Chromatographic separation was accomplished with a methanol and 0.1% formic acid (60:40) isocratic flow system on a Phenomenex Luna C18 column (4.6 × 250 mm, 5 μm) at a 1 mL/min flow rate. The method was rigorously validated according to ICH guidelines. Linearity was observed over a concentration range of 2 to 10 µg/mL for both EGCG and RA, yielding correlation coefficients of 0.998 and 0.999, respectively. The LOD and LOQ were determined to be 0.51 µg/mL and 1.54 µg/mL for EGCG, and 0.35 µg/mL and 1.07 µg/mL for RA. Moreover, the %RSD for all validation parameters were consistently below 2%. Forced degradation studies were conducted under acidic, basic, oxidative, and photolytic conditions to elucidate potential degradation pathways and identify degradation products. The developed method was applied to estimate EGCG and RA in prepared lipid-based nanocarriers and biological fluids like blood plasma and urine. Recovery assays in lipid-based nanocarriers, plasma, and urine samples demonstrated excellent recoveries (96.2–102.1%). The method's greenness was assessed using various tools, and its accuracy was evaluated using Six Sigma methodology. Overall, the developed HPLC method offers a rapid, sensitive, and reliable approach for quantifying EGCG and RA, laying the groundwork for their further investigation as anticancer agents, alone and in combination therapies.

Insights into interspecies protein binding variability using clindamycin as an example

Abstract Background In the preclinical development of new drugs, animal models are often employed to predict their efficacy in humans, relying on translational pharmacokinetic/pharmacodynamic (PK/PD) studies. We performed in vitro experiments focusing on the comparison of plasma protein binding (PPB) and bacterial growth dynamics of clindamycin, a commonly used antimicrobial agent, across a range of drug concentrations and plasma environments. Methods Human, bovine and rat plasma were used for determining PPB of clindamycin at various antibiotic concentrations in buffer and media containing 20% to 70% plasma or pure plasma using ultrafiltration (UF) and equilibrium dialysis (ED). Also bacterial growth and time–kill assays were performed in Mueller–Hinton broth (MHB) containing various percentages of plasma. Results Protein binding of clindamycin correlated well between UF and ED. Notably, clindamycin exhibited substantially lower protein binding to rat plasma compared with human and bovine plasma. Staphylococcus aureus growth was significantly reduced in 70% human, bovine, and rat plasma after 4, 8 and 24 h compared with standard MHB. Time–kill data demonstrated that bacterial counts at both 20% and 70% plasmas were less when compared with MHB at drug concentrations lower than MIC after 4 and 8 h of incubation. For rat plasma, the difference was maintained over 24 h of incubation. Furthermore, a complete bacterial killing at 16 mg/L was observed after 24 h in 20% and 70% human and bovine plasma, but not for rat plasma. Conclusions Recognizing interspecies differences in PB might be essential for optimizing the translational relevance of preclinical studies.

Pressure and Isothermal Compressibility of Asymmetric Complex Plasmas in the Poisson–Boltzmann Plus Hole Approximation

ABSTRACTWe consider a two‐component asymmetric complex plasma of finite‐size macroions with charges () and point oppositely charged microions with unit charges. System pressure is calculated within the framework of the Poisson–Boltzmann plus hole approximation by obtaining the Coulomb nonideal parts of interaction energy and Helmholtz free energy. It is shown that both the pressure and plasma isothermal compressibility are positive over the entire range of macroion concentrations. We compared pressure and isothermal compressibility in linearized approximations and in the Poisson–Boltzmann plus hole approximation where the nonlinear screening effect is taken into account and showed a significant difference for some macroions concentrations.

A High‐Efficiency System for Long‐Term Salinity‐Gradient Energy Harvesting and Simultaneous Solar Steam Generation

AbstractThe vast energy stored in the ocean, which receives an average solar power of ≈60 000 TW per year, surpasses human energy consumption by three orders of magnitude. Harnessing even a small fraction of it holds great promise in addressing global energy and water crises. Here, an integrated device that achieves unprecedented power density up to 1.1 W m−2 with excellent stability through a salinity concentration gradient induced by solar evaporation, while simultaneously producing clean water at a rate of 1.25 kg m−2 h−1 under one sun irradiation is presented. The remarkable electricity generation capability stems from the unique interlayer structure of polyaniline‐graphene oxide‐MnO2 (PANI@GO/MnO2) electrodes, enabling the recovery of electrochemical potentials from a wide range of ion salinity concentrations within the device and the additional Donnan potential generated by the anion‐exchange membrane. Furthermore, periodic flipping of the device effectively reactivates the electrodes and suppresses salt accumulation, enabling long‐term operation. Notably, a prototype device of 8 × 25 cm2 exhibits a short‐circuit current of 10 mA and an open‐circuit voltage of 10.2 V, as well as a clean water production rate of 24.8 g per hour. These findings shed light on the reliable technology for power and freshwater supply in marine environments.

Easy-to-Engineer Flexible Nanoelectrode Sensor from an Inexpensive Overhead Projector Sheet for Sweat Neuropeptide-Y Detection.

In this paper, we report an inexpensive and easy-to-engineer flexible nanobiosensor electrode platform by exploring a nonconductive overhead projector (OHP) sheet for sweat Neuropeptide-Y (NPY) detection, a potential biomarker for stress, cardiovascular regulation, appetite, etc. We converted a nonconductive OHP sheet into a conductive nanobiosensor electrode platform with a hybrid polymerization method, which consists of interfacial polymerization of pyrrole and a template-free electropolymerization technique to decorate the electrode platform with poly(EDOT-COOH-co-EDOT-EG3) nanotubes. The selection of poly(EDOT-COOH) features an easy conjugation of NPY antibody (NPY-Ab) through EDC/Sulfo-NHS coupling chemistry, while poly(EDOT-EG3) is best known to reduce nonspecific binding of biomolecules. The antibody conjugation on the polymer surface was characterized by a quartz crystal microbalance, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and chronoamperometry techniques. The OHP nanosensor platform exhibited the successful detection of NPY analyte through a chronoamperometry method in phosphate-buffered saline with a wide range of concentrations from 1 pg/mL to 1 μg/mL with a limit of detection of 0.68 pg/mL having good linearity (R2 = 0.9841). The sensor platform exhibited excellent stability, reproducibility, repeatability, and a shelf-life of 13 days. Furthermore, the sensor showed superior selectivity to a 100 pg/mL NPY analyte among other interfering compounds such as tumor necrosis factor α, cortisol, and Interleukin-6. The clinical practicality of the sensor was confirmed through the detection of 100 pg/mL NPY spiked artificial perspiration, highlighting the possibility of integrating the sensor platform to wearable healthcare applications.