The coaxial core/shell composite electrospun nanofibers consisting of relaxor ferroelectric P(VDF-TrFE-CTFE) and ferroelectric P(VDF-TrFE) polymers are successfully tailored towards superior structural, mechanical, and electrical properties over the individual polymers. The core/shell-TrFE/CTFE membrane discloses a more prominent mechanical anisotropy between the revolving direction (RD) and cross direction (CD) associated with a higher tensile modulus of 26.9 MPa and good strength-ductility balance, beneficial from a better degree of nanofiber alignment, the increased density, and C-F bonding. The interfacial coupling between the terpolymer P(VDF-TrFE-CTFE) and copolymer P(VDF-TrFE) is responsible for comparable full-frequency dielectric responses between the core/shell-TrFE/CTFE and pristine terpolymer. Moreover, an impressive piezoelectric coefficient up to 50.5 pm/V is achieved in the core/shell-TrFE/CTFE composite structure. Our findings corroborate the promising approach of coaxial electrospinning in efficiently tuning mechanical and electrical performances of the electrospun core/shell composite nanofiber membranes-based electroactive polymers (EAPs) actuators as artificial muscle implants. Electroactive polymers (EAPs) which change shape or size under applying an electrical stimulus are widely used for diverse applications of electromechanical devices in transducers, sensors, actuators, artificial muscles, smart skin, and soft robotics ,4,5,6,7.Among the various methods in producing the incorporation of different polymers, electrospinning has recently emerged as one of the most efficient and successful techniques due to its wide applications for fabrication of continuous fibers with diameters in a nanometer scale ,22,23,24In the present study, we utilized the coaxial electrospinning process to produce core/shell composite fibrous membranes, namely the core/shell-copolymer/terpolymer (core/shell-TrFE/CTFE) and core/shell terpolymer/copolymer (core/shell-CTFE/TrFE), in comparison with the pristine P(VDF-TrFE-CTFE) and P(VDF-TrFE) fabricated via the uniaxial electrospinning method. An intensive investigation of those four single and coaxial electrospun nanofibers was conducted in terms of their structural, mechanical, dielectric, and piezoelectric responses in order to evaluate the feasibility of coaxial composite fibrous membranes-based EAP actuators as artificial muscles.S is the fiber orientation order parameter and S is 1, while they are randomly oriented when the value of S is 0. The larger the value of S, the higher the degree of fiber orientation.irection ,47. The The fiber orientation order parameters were characterized to be 0.46, 0.25, 0.61, and 0.47 in the P(VDF-TrFE-CTFE), P(VDF-TrFE), core/shell-TrFE/CTFE, and core/shell-CTFE/TrFE films, respectively. Among the four types of electrospun nanofibers, the neat P(VDF-TrFE) nanofibers were more randomly oriented, while the coaxial core/shell-TrFE/CTFE nanofibers were better aligned. It can be noted that there was a negligible discrepancy in density between the neat P(VDF-TrFE) and P(VDF-TrFE-CTFE), while the densities of the coaxial core/shell-TrFE/CTFE and core/shell-CTFE/TrFE were 2 and 1.5 times greater than those of the pure membranes. Such a denser arrangement of nanofibers in the coaxial core/shell structures was presumably assigned to strong interactions between the copolymer and terpolymer layers.Since the electrospun fibrous membranes exhibited an obvious degree of nanofiber orientation, the tensile tests were performed in both the revolving direction (RD) and cross direction (CD) to examine the response of aligned nanofibers to anisotropic mechanical properties . The tenThe values of tensile modulus, tensile strength, and elongation determined from the S-S curves of the four eletrospun nanofiber sheets were presented in The tensile properties of the core/shell composite nanofibers were successfully tailored by the coaxial electrospinning technique. The coaxial core/shell-CTFE/TrFE revealed the mechanical tunability between those of the neat P(VDF-TrFE-CTFE) and P(VDF-TrFE) nanofibers. Meanwhile, the coaxial core/shell-TrFE/CTFE membrane disclosed superior mechanical performances of higher Young’s modulus of 26.9 MPa and a comparable tensile strength of 25.3 MPa in the RD, accompanied with an excellent ductility of 487.2% with little sacrifice of strength in the CD compared with the single electrospun fibrous membranes. Our results were in agreement with the previous reports that the core/shell composite nanofibers fabricated using the coaxial electrospinning process exhibited more salient mechanical properties over the neat materials ,43. It cThe mechanical response of the coaxial electrospun nanofibers is strongly governed by combined effects of the polymer material types in the core and shell, morphology and diameter distribution of nanofibers, degree of nanofiber alignment, density of electrospun membrane, chemical and physical interactions of the polymer chains, and defects or impurities . A highecE is the modulus of the composite, mE and fE are the moduli of the matrix and fibers, mV and fV are the volume fraction of the matrix and fibers, respectively.To study how the volume fraction of fibers affects the tensile moduli of the coaxial electrospun composite structures, the experimentally measured tensile moduli of the core/shell composite nanofibers were compared with the theoretically predicted moduli calculated from the two individual polymer components using the upper bound (Equation (2)) and the lower bound (Equation (3)) for the rule of mixtures . The low3 (1190 cm−1), T3G (848 cm−1), and TGTG (475 cm−1) [−1 was visible in the single electrospun nanofibers, however, that peak was significantly sharper in the coaxial composite structures, representing the C-F bond in the T3 conformation. Since the bonding energy of the C-F bond is stronger than that of the other bonds, the increased C-F bond was presumably ascribed to the enhancement in Young’s modulus and tensile strength of the coaxial electrospun films.To better understand the role of other possible reasons contributing to the mechanical response of four electrospun membranes, Fourier-transform infrared spectroscopy (FTIR) was conducted to investigate the chain conformation in the single and coaxial electrospun films. 75 cm−1) ,53. No e3, trans–gauche T3G, and short trans TGTG) in the single and coaxial electrospun films [i = 1, 2, 3, and A1, A2, and A3 are the integrated areas of T3, T3G, and TGTG chain conformations, respectively.In order to identify the variation in the reflection intensities of the three major chain conformations  and P(VDF-TrFE) sheets. With the increase of copolymer volume portion of 62.5% in the shell, the ratio of highly polar ferroelectric T3 reached the highest value, while that of polar relaxor ferroelectric T3G dropped to the lowest value, implying a more pronounced impact of copolymer-based shell in the enhanced FE phase accompanied with the reduced RFE phase in the coaxial core/shell-CTFE/TrFE composite structure. A negligible variation of nonpolar TGTG conformation was seen in the single and coaxial nanofibers.β reflection in the crystalline β phase along the CD and preferred (001)β and β crystallographic planes along the RD were obtained in the four electrospun sheets [β and β, while the copolymer P(VDF-TrFE) disclosed their distinct reflections.Since the electrospun films showed an anisotropic orientation of nanofibers, the wide-angle X-ray diffraction (WAXD) was employed to explore the preferred crystallographic texture orientation in the single/coaxial electrospun fibrous membranes. n sheets ,14. The β reflection in the RFE crystalline P(VDF-TrFE-CTFE) was located at 2θ = 9.9° in β reflections from the RFE and FE crystallines, implying a partial infiltration of copolymer with terpolymer chains. On the other hand, only the β reflection in the FE crystalline β phase from the copolymer was visible in the coaxial core/shell-CTFE/TrFE sheet, as shown in To acquire a further analysis in the evolution of crystallographic planes, the corresponding one-dimensional (1D) intensity profiles of the four electrospun sheets were shown in Xc) was defined according to the following equation:Ac and Aa are the integrated areas of the crystalline peaks and amorphous regions, respectively [To clarify the effect of coaxial electrospinning on the crystalline properties of the composite nanofibers, the degree of crystallinity and polar crystalline domain size were extensively examined. The degree of crystallinity , P(VDF-TrFE), core/shell-TrFE/CTFE, and core/shell-CTFE/TrFE, respectively. The pristine P(VDF-TrFE) showed better crystallinity than the pristine P(VDF-TrFE-CTFE). A higher degree of crystallinity in the coaxial composite nanofibers rather than in the pristine terpolymer was obtained.L) representing the RFE or FE domain size of the corresponding β crystallographic plane was calculated using the Scherrer equation:λ is the X-ray wavelength, B is the full width at half-maximum (FWHM), and θ is the angle of the diffraction peak.The crystallite size β-co in the pristine copolymer. The addition of the third monomer CTFE considered as a defect causes the break of a larger micrometer-sized FE into smaller nanometer-sized RFE crystal domains, thus decreasing the FE crystalline domain size and crystallinity of the copolymer P(VDF-TrFE) [The crystallite sizes of the 110,200)0,200β reDF-TrFE) . The corThe dielectric constant of the pure P(VDF-TrFE-CTFE) was obviously higher than that of the pure P(VDF-TrFE) over the whole frequency range due to the nanopolar regions of RFE in the terpolymer ,10,63. TThe dielectric response under a low electric field is not sufficient enough to reflect the overall polarization mechanism of electrospun nanofibers, therefore, it is of great need to measure the piezoelectric response under a high electric field. The local piezoelectric performance was conducted using piezoresponse force microscopy (PFM) . The ind33,eff), which was determined by comparison with the slope of the standard ZnO sample.The slope of piezoelectric amplitude response in the four electrospun nanofibers represents the effective piezoelectric constant  was 30.2 pm/V, twice higher than that of the pure P(VDF-TrFE) (14.6 pm/V), presumably attributed to the higher saturation polarization under a high electric field of the terpolymer [33,eff of the coaxial core/shell-CTFE/TrFE (15.4 pm/V) was slightly higher than that of the copolymer, while the d33,eff of the core/shell-TrFE/CTFE reached the highest value of 50.5 pm/V, due to the coexistence of RFE and FE crystalline domains associated with highly aligned dipole moments. Such a very outstanding d33,eff in the coaxial core/shell-TrFE/CTFE was very close to the previously reported d33,eff value of the annealed terpolymer (52 pC/N) [The slope and corresponding drpolymer . The d3352 pC/N) . TherefoIn general, the coaxial electrospun core/shell-TrFE/CTFE composite nanofiber membrane manifested superior mechanical properties over the pristine polymers, which was similarly obtained in other electrospun composite nanofibers ,43. FurtThe copolymer P(VDF-TrFE) (75/25 mol%) and terpolymer P(VDF-TrFE-CTFE) (61.7/30.4/7.9 mol%) powders were from Arkema Group . The polymer powder was dissolved in a cosolvent of DMAc  and MEK  with a ratio of 2:3, the mixture was then heated at 60 °C for 3–4 h using a magnetic stirring. The solutions of 13 wt% P(VDF-TrFE) and 13 wt% P(VDF-TrFE-CTFE) were obtained and cooled to room temperature. Four different kinds of electrospun nanofibers, namely, pristine P(VDF-TrFE), pristine P(VDF-TrFE-CTFE), and coaxial core/shell composite structures of CTFE/TrFE and TrFE/CTFE nanofibers were fabricated. The neat P(VDF-TrFE) and P(VDF-TrFE-CTFE) films were fabricated using uniaxial electrospinning, while the two various core/shell structures were produced using the coaxial electrospinning technique.The uniaxial and coaxial electrospinning processes were performed at 24 °C with a relative humidity of 55% using a self-made electrospinning machine. A 10 mL syringe pump and a 20 G stainless steel needle (inner diameter of 0.6 mm) filled with the blend solution were driven at a feeding rate of 1 mL/h in the uniaxial electrospinning process.The coaxial electrospinning process requires two concentrically detachable stainless steel needles, 20 G as outer and 26 G (inner diameter of 0.26 mm) as inner ones. The schematic illustration of coaxial electrospinning can be found elsewhere ,25,31,36The collector was a custom-made rotating cylindrical drum with a diameter of 18 cm and rotated at a speed of 800 rpm. A high DC voltage of 18 kV was applied between the positive electrode (connected to the needle) and negative electrode (connected to the collector) at a working distance of 18 cm.−1.Electrospun nanofiber morphology was analyzed using the scanning electron microscope  operating at 15 KeV. The samples for SEM measurements were sputter-coated with platinum. The chain conformation in single and coaxial electrospun nanofibers was measured by Fourier-transform infrared spectroscopy (FTIR) using a Perkin Elmer spectrum 100 spectrometer in the frequency range of 400–4000 cmThe four electrospun membranes with the thickness in the range of 20–125 μm measured by the cross-sectional SEM were cut into dog-bone shaped specimens with a total length of 50 mm, a gauge length and width of 10 and 3 mm, respectively. The tensile test was conducted by a micro-stretching machine equipped with a 50 kg load cell at a stretch rate of 0.1 mm/min until failure. The specimens were strained in both the RD and CD, parallel and perpendicular to the alignment of nanofibers, respectively.The non-destructive wide-angle X-ray diffraction was implemented at the beamline (BL) 01C2, National Synchrotron Radiation Research Center (NSRRC), Taiwan. Diffraction patterns were recorded by a 2D detector to acquire the preferred orientation of crystallographic planes.The dielectric response as a function of frequency from 12 to 200 kHz was measured using a LCR-821 impedance analyzer at 1 V at room temperature. The effective piezoelectric constant was acquired using the PFM function in the Park XE7 atomic force microscope (AFM) coupled with a phase-locked amplifier.The effective tunability of structural, mechanical, dielectric, and piezoelectric properties of the core/shell composite nanofibers consisting of terpolymer P(VDF-TrFE-CTFE) and copolymer P(VDF-TrFE) was successfully attained via the coaxial electrospinning approach. The coaxial electrospun core/shell films revealed a better alignment and denser packing of nanofibers accompanied with stronger C-F bonding compared with the neat polymers. Such outstanding combined effects contributed to the significant enhancement in Young’s modulus coupled with a superior tensile strength and elongation to rupture, especially achieved in the core/shell-TrFE/CTFE. The coaxial core/shell-TrFE/CTFE composite nanofiber membrane exhibited more pronounced mechanical, dielectric, and piezoelectric performances, which enables potentially promising applications of EAP actuators as artificial muscles.


The reported LODs for sulfadiazine and sulfamethazine detection are consistent with requirements for trace-level monitoring by early warning diagnostic systems.Polyamic acid (PAA) nanofibers produced by using the electrospinning method were fully characterized in terms of morphology and spectroscopy. A PAA nanofiber–modified screen-printed carbon electrode was applied to the detection of selected sulfonamides by following an electroanalytical protocol. The polyamic acid (PAA) nanofibers were characterized using Fourier transform infrared (FTIR) spectroscopy to study the integrity of polyamic acid functional groups as nanofibers by comparing them to chemically synthesized polyamic acid. A scanning electron microscope (SEM) was used to confirm the morphology of the produced nanofibers and 3D arrangement at the electrode interface. The Brunauer–Emmett–Teller (BET) method was used to determine the surface area of the nanofibers. Atomic force microscopy (AFM) was used to study the porosity and surface roughness of the nanofibers. Electrochemical evaluation based on diffusion-controlled kinetics was applied to determine the number of electrons transferred in the system, the surface concentration of the deposited PAA thin film (2.14 × 10 Electrospinning is an efficient and highly scalable method used for preparation and production of a variety of nanostructured polymer materials. The process of electrospinning requires the application of controlled voltage to produce fibers from charged polymer solutions producing fibers with diameters ranging from micron to nanometer size . These pin situ at Au and glassy carbon electrode surfaces and functionalized in various ways to prepare very efficient electrochemical sensors (Polyamic acid (PAA) is a polyimide precursor polymer with amide and carboxylic functional groups. PAA is easy to synthesize and process due to its high solubility in aprotic solvents. PAA polymer thin films may easily be produced  sensors . While eElectrospinning of continuous fibers is improved by chemical cross-linkers, additives, and carrying polymers when spinning low–molecular weight polymers such as PAA . PolyvinThe reagents 4, 4-oxydianiline (97%), 1, 2, 4, 5-benzenetetracarboxylic anhydride (97%), acetonitrile (99%), N,N-dimethylacetamide (DMAc), dimethylformamide (DMF), trizma–hydrochloric acid (Tris–HCl), polyvinylpyrrolidone (MW. 130000 g/mol), sulfadiazine (99%), and sulfamethazine (99%) were all obtained from Sigma-Aldrich, South Africa. All chemicals were of analytical grade and used without further purification. Deionized (ultra-pure) water purified at a resistivity of 18.2 MΩ/cm. A Milli-QTM system (Millipore) was used for preparation of all aqueous solutions.Polyamic acid was synthesized from organic solvents, using 4, 4-oxydianiline and benzene 1,2,4,5-tetracarboxylic anhydride precursors, as previously described in the literature . A blendAn electrospinning instrument from IME technologies situated in the chemical engineering department (HySA) at the University of Cape Town was used to produce nanofibers. Fourier transform infrared spectroscopy was carried out using a PerkinElmer Spectrum 100 instrument. Thermal stability data for freestanding PAA nanofibers were obtained by using thermogravimetric analysis (TGA) Q500 V3.13 Build 261 in the temperature range of 10–475°C at a heating rate of 10°C/min in atmospheric nitrogen. The morphology studies were conducted on a Hitachi S3000N scanning electron microscope (SEM) and Zeiss Auriga high-resolution field emission gun (fegsem) scanning electron microscope (HRSEM) for samples deposited onto a carbon grid. Electrochemical deposition and evaluation were performed using a PalmSensPTrace 4.4 workstation . The electrodeposited thin films and electrospun nanofibers were prepared on screen-printed carbon electrodes from DropSens . Nitrogen sorption experiments were performed on a Micromeritics TrisStar II 3020 version 2.0 instrument. The surface area was calculated from the Brunauer–Emmett–Teller (BET) equation. The Nanosurf EasyScan2 was used with highly doped silicon material probing tips with a resistivity of 0.01–0.02 (from NANOSENSORS™). Atomic force microscopy (AFM) was used to study the average height distribution of the screen-printed electrodes modified with polyamic acid nanofibers.2) and auxiliary (carbon) and reference electrodes (Ag/AgCl). The SPCE was inserted into 3 ml electrolyte solution which was bubbled with argon gas to remove dissolved oxygen. The working electrode surface was activated by five scans using the cyclic voltammetry technique at 50 mV/s, prior to data collection in electrochemical characterization of material and evaluation of the selected analyte. These instrumental parameters were consistently applied to all electrochemical experiments.Scan rate–dependent cyclic voltammetry (CV) was used to evaluate the electrochemical integrity of the deposited PAA materials and, subsequently, its analytical response toward the quantification of a selection of sulfonamides. Scan rates ranged from 10 to 100 mV/s, with a potential window set between −1,000 and +1,000 mV vs. Ag/AgCl in a 0.1 M phosphate buffer (pH 7) electrolyte. The electrochemical determinations of sulfonamides were done in 0.1 M Tris–HCl (pH 8) using square wave voltammetry (SWV) at a scan rate of 50 mV/s, which was achieved by setting the frequency to 10 Hz and the step potential to 5 mV vs. Ag/AgCl. The electrochemical measurements were performed using the three-electrode screen-printed system cell, that is, working electrode , acetone, NMP, acetonitrile (ACN), tetrahydrofuran (THF), methanol, chloroform, diethyl ether, and tetrahydrofuran/methanol (1:1 ratio) at concentrations 1, 5, 10, and 20% wt. PAA. However, polyamic acid was found to be completely soluble in DMF and DMAc, which are high–boiling point aprotic solvents  see .Chemically synthesized PAA did not provide solutions in DMF and DMAc for spinning on its own. Low concentrations of PVP  were added to 12% by wt. PAA solutions using DMF and DMAc, respectively. Each of these solutions were tested in terms of the quality of nanofibers that could be produced under the optimized instrumental parameters. The optimal spinning solution was produced from 12% by wt. PAA and 3% by wt see . PVP dis−1 to 1,000 cm−1, from prepared potassium bromide (KBr) pellets. The FTIR spectra of the PAA nanofibers and chemically synthesized PAA were found to be in good agreement with literature reports  were assigned to the vibrational modes of carboxylic acid. A spike appearing at 3,049 cm−1 was assigned to the NH stretching vibration. The strong peak at around 1,239 cm−1 was indicative of the stretching vibrations of the ether group. The FTIR spectra confirmed the integrity of the PAA prepared as nanofibers from electrospinning, by comparison with literature reports as well as with the FTIR data obtained for the chemically synthesized PAA, also done in this work.The free-standing nanofibers were collected on aluminum foil. FTIR spectra  of PAA p reports . The absn = 4). Average layer thickness for electrodeposited PAA films was measured to be 17.63 ųm  and 26.54 µm . The increased layer thickness is due to the space trapped within the nanofiber networks, resulting in a highly porous material with enhanced surface area and robustness. Thus, electrospinning is able to produce intact, mechanically stable, and high–surface area nanofiber networks spun directly onto the working electrode surface of the commercial SPCE. The efficient control over the nanomaterial structure and deposition demonstrated here with the electrospinning of PAA is a major advantage in the design of highly reactive electrocatalysts for a wide range of applications.The high-resolution scanning electron microscope (HRSEM) provides electron backscattering images of the deposited spun nanofibers directly onto a screen-printed carbon electrode (SPCE). SEM images of the PAA nanofibers were identified as an entwined network of nanoscale dimension fibers . The diaf = f − f0) as a function of the X–Y variation in height without regulation in the z-direction (x–y direction without height regulation in the z-direction. The average height distribution of PAA nanofibers was measured as 6.02 µm.The atomic force microscopy (AFM) was used to obtain topographical images in the contact mode of PAA nanofibers , which rirection . A samplThe AFM provides a top-down force sensing measurement of depth. The HRSEM provides surface imaging of the nanofibers in a similar top-down approach but with actual surface feature data generated from backscattered electron imaging. The HRSEM identified the structural arrangement of the nanofibers on the electrode and showed a controlled mesh of nanofibers. The cross-sectional SEM imaging of these nanofibers provided a deep distribution profile of the nanofibers and the entrapped pores between them, showing clearly that the nanofibers have a very dense packing close to the electrode surface, becoming porous as we move away from the electrode surface. This supports the characterization of the deposited nanofibers as a 3D network at the electrode surface from which diffusional properties were assessed.2 measurements were used to study the surface structures of the freestanding polyamic acid (PAA) nanofibers. Based on the BET measurements [see 2/g, comparable to the surface area of synthesized carbon-based nanomaterials such as multi-walled carbon nanotubes with BET surface area ranging from nine up to 500 m2/g  was recorded at scan rates ranging from 10 to 100 mV/s. The redox behavior of PAA nanofibers observed from CV see  was char, in the CV data collected at PAA/SPCE using the following equation:1/2 is half maximum peak potential, R is the gas constant (8.314 j.mol.k−1), T represents the absolute temperature (298 of the gas system), n is the number of electrons, and F is the Faraday constant . The a/a redox chemistry was found to be a one-electron transfer process associated with the amine functionality of surface bound PAA/SPCE. The surface concentrations of physically adsorbed PAA nanofibers onto the SPCE was estimated from the plot of peak current vs potential at a scan of 50 mV/s , v is the scan rate (V/s), I* is the surface concentration (mol cm−2), and F, R, and T are the same as in −6 mol/cm2. The Randles–Sevcik plot (see e) of the screen-printed carbon–PAA nanofiber electrode. The diffusion coefficient (De) of the SPCE–PAA nanofiber electrode was calculated to be 9.43 × 10−7 cm−2/s. The values reported the literature for diffusion-controlled behavior of PAA thin film–coated electrode surfaces are 6.35 × 10−7 cm2/s , 7.10 × 10−6 cm2/s (electrodeposited onto a glassy carbon electrode using 20 cycles between −400 mV and +600 mV at a scan rate of 50 mV/s), and 5.25 × 10−6cm2 , respectively. The limit of detection (LOD) of sulfadiazine and sulfamethazine was based on the oxidation of the para -NH2 group observed at 0.78 V vs Ag/AgCl. The LOD was found to be 8.26 ± 2.07 ųM and 8.81 ± 3.06 μM, respectively. The PAA nanofiber–modified screen-printed electrodes showed good sensitivity toward sulfadiazine (0.05 ± 0.01 μA Lmol−1) and sulfamethazine (0.07 ± 0.02 µA μlmol−1), which we believe is due to the higher surface area and porosity of the nanofibers network enhancing the catalytic efficiency of the oxidation. However, the reproducibility of the repeated experiments for sulfamethazine was not as good as that for sulfadiazine. Sulfamethazine has methyl group substituents that may affect its alignment at the sensor interface and consequently impact reproducibility.The two peaks observed at −0.03 V vs. Ag/AgCl and 0.25 V vs. Ag/AgCl were attributed to the porous electrospun polymer material. The sulfadiazine  and sulfA comparison of the sensitivity of carbon-based nanomaterial electrodes toward sulfonamide detection showed that carbon nanotubes and PAA electrospun nanofibers outperformed nanoparticles, molecularly imprinted methods, and polymer blends used in the preparation of transducers for the detection of sulfonamides using the SWV method . The impThe solubility behavior of polymers is crucial in its application as thin film devices such as sensors, photovoltaic cells, and interpenetrating network actuators. We have shown that PAA could be uniformly dispersed in two key organic solvents at relatively high-concentration loading. Subsequently, the critical mass for efficient electrospinning of PAA could be achieved by minimal incorporation of a carrier polymer, which resulted in highly dispersed, uniform nanofibers which could be deposited directly onto the working electrode area of commercial SPCE as well as freestanding nanofibers. The carrier polymer (PVP) did not influence the redox electrochemistry of the PAA as evidenced by the pronounced electrochemical reporting signals obtained. Quantitative analysis of selected sulfonamides corroborated the implication of size and structure on the performance of nano-electrocatalysts. The freestanding PAA nanofibers have potential applications as robust portable electrodes in real-world sensor applications.


There were also significantly fewer episodes of ESI complicated with catheter-related blood stream infection (CRBSI) requiring the CTC removal . The REDS scale appears to be a simple, cost-effective tool reducing the frequency of the tunneled CTC exit site infection and associated bloodstream infections.Central tunneled catheter (CTC)-related infections are a leading cause of a catheter loss, thus being the source of significant morbidity and mortality. The study aims at evaluating the impact of the implementation of the innovative redness, edema, discharge and tenderness, symptoms (REDS) scale (devised by the authors) for the description of the tunnel condition on the frequency of infection in long-term catheter users. The same cohort of the 40 patients was observed for 4 years altogether: 2 years before and 2 years after REDS application. The results, as well as follow-up evaluation of participants, were compared. The 2-year cumulative incidence of the CTC exit site infection (ESI) dropped significantly (log-rank  Central tunneled catheter (CTC) is used in a large part of hemodialysis patients awaiting arteriovenous fistula maturation or as the only possible vascular access option when other ones have been exhausted and/or prevented by comorbidities. Improper use of CTC carries a risk of life-threatening catheter-related bloodstream infections (CRBSI), often complicated with metastatic abscesses, endocarditis, not infrequently with fatal consequence –5. RecenForty-eight patients were initially included in the study. For all of them, a tunneled CTC was the only possible vascular access option. During the observation period (from 2012 until the end of 2015), five patients died due to cardiovascular events and two more due to cancer disease. One patient was transferred to peritoneal dialysis because the possibility of a further CTC use had been exhausted. After 2015, further eight death cases occurred: five—due to cardiovascular causes, one—due to complicated cholecystitis, one—due to complicated diverticulitis, and one as a consequence of kidney cancer. Finally, the study group consisted of 40 patients hemodialyzed through CTC from January 2012 until December 2015. For those individuals, complete follow-up records of a period of 2 years before and 2 years after the REDS scale application were available. The database included characteristics of the patients, REDS scoring, actions taken, and the patients' follow-up evaluation, as shown in 0—normal exit site .1—exit site redness .2—exit site redness and edema .3—exit site redness and edema, and discharge or discharge only .4—exit site redness and edema, tenderness and discharge, and systemic symptoms .Systemic symptoms were defined as body temperature >38 or <36°C, chills, hypotonia with systolic blood pressure <90 mmHg, tachycardia >90/min, and unusual patient confusion. After exit site scoring with the REDS scale, the following actions were taken accordingly:REDS 0—no action was taken; the score was recorded.REDS 1—incident was recorded in the notes, and the staff was alerted to evaluate the CTC exit site on the following HD sessions.REDS 2—the incident was recorded in the notes, the senior staff/doctor was informed, and the patient was evaluated. Special alertness on the following HD sessions was called for.REDS 3—the incident was recorded in the notes, senior staff/doctors were informed, and the patient was evaluated; blood samples were collected for tests, exit site swabs, and blood cultures, both from CTC and peripherally, were taken. An oral or intravenous antibiotic empirical treatment was initiated for 3 weeks, in accordance with our hospital infectious disease control committee guidelines . The patient was evaluated using the REDS scale on every session, and the blood tests were repeated weekly. When REDS decreased to 2 and 1, the treatment was completed as planned. If the blood cultures were positive, the CTC, when possible, was removed, and a temporary catheter was inserted in a different location. When no alternative venous site was available, the CTC was exchanged for an acute line over-the-wire during antibiotic therapy, and then modified in relevance with the microbiologic tests results.REDS 4—the senior staff and the doctor were informed immediately; the exit site swab and blood samples were taken for cultures from the CTC and peripheral vein, as well as for blood tests. Empirical antibiotic was given . Afterwards, the catheter was removed when possible, and a temporary catheter was inserted in a different location. When no alternative sites could be found, the CTC was exchanged for an acute line over-the-wire. In case of an indication for urgent hemodialysis , the procedure was carried out through the infected CTC, and further actions were taken thereafter.Tunnel infection (TI) was diagnosed when pain, swelling, redness of skin along the CTC, as well as purulent discharge from the exit site were observed. The same actions were taken as in the REDS 4 score. CRBSI was suspected when systemic symptoms were present, confirmed by blood and culture tests, with or without REDS 3 to 4 or tunnel infection signs. However, in the case of the last option CTC, the patient was put on systemic empirical antibiotic, with blood cultures taken from the line and peripherally, at the beginning of the evaluation and 48 h later. In case of no response to treatment, the CTC was exchanged over-the-wire for a temporary line. The next exchange of the catheter was carried out after clinical improvement, with negative blood culture tests, and the regression of the inflammation confirmed by the blood test. The nurses, as well as senior medical staff, were trained in the use of the REDS scale; appropriate materials were prepared, including posters and forms, which were attached to the patients' records. It was crucial, as the nursing staff was responsible for the CTC dressing change, exit site scoring and, when necessary, the sample collection. On the basis of that initial evaluation, the doctor was informed to take proper action. The results were analyzed monthly, and a complete report was prepared yearly from January 2014 until December 2018.In pre-REDS period, the exit site infection was defined, at the nursing staff's discretion, by the presence of redness, swelling, and discharge. In that case, blood samples and skin swabs were taken routinely and an empirical antibiotic was given. When discharge was absent, blood was tested and the beginning of treatment depended on the clinician's decision, i.e., when CRP and WBC were significantly elevated. The presence of discharge without the accompanying exit site skin changes was an indication for a swab, blood test, and empirical treatment based on the obtained results, and modified accordingly to microbiologic report. In the case of the appearance of systemic symptoms like fever, chills, hypotonia, tachycardia, and unusual confusion suggesting CRBSI—after other sources of infection were excluded —blood samples for culture and tests were obtained peripherally and from CTC, followed by empiric antibiotic administration, as mentioned above.All investigated procedures aimed at the treatment of complications threatening the vascular access for life-supporting hemodialysis. The CTC exit site REDS scale scoring was an improvement of the already existing vital signs recording and physical examination performed before every hemodialysis session. Due to this fact, an opinion from the Opole University Bioethics Committee was expressed that this type of observational study dictated by the clinical needs does not require authorization. Informed consent was obtained from all the individual patients before the procedure requiring catheter removal and reimplantation. Those procedures were conducted in accordance with the ethical standards of the Declaration of Helsinki from 1964 and its later amendments.n  and continuous variables as mean (SD). All the CTC-related infectious complication were presented as episode per 1,000 catheter-days , then a cumulative incidence of all episodes was calculated using the Kaplan-Meier survival analysis method, including 95% confidence interval. Log-rank Cox-Mantel test was used to compare cumulative incidence level between pre-REDS and REDS periods (based on 4-year data). Additionally, the Cox hazard ratio regression analysis models were used to identify the factors significantly impacting the incidence of infections. The analyses were carried out with the use of statistical software R .Nominal variables are presented as Patient group characteristics are presented in p < 0.001; p = 0.04, in pre-REDS and REDS time, respectively; p = 0.05; p = 0.5).After the REDS scale introduction, ESI  occurrence decreased to the rate of 0.26 and 0.47 episode/1,000 cd in 2014 and 2015, respectively, compared with 0.89 episode/1,000 cd in both 2012 and 2013, in pre-REDS time . From 20p = 0.05; Infections are the second leading cause of death among dialysis patients, and central venous catheter (CVC) use for hemodialysis (HD) is associated with the increased rates of infection, as compared with other types of vascular access –3. For tThe introduction of the formal evaluation of the tunneled catheter exit site before each dialysis session using the innovative REDS scale reduced significantly the frequency of the exit site infections and the associated catheter-related bloodstream infections in the long-term catheter carriers.The original contributions presented in the study are included in the article/Ethical review and approval was not required for the study on human participants in accordance with the local legislation and institutional requirements. The patients/participants provided their written informed consent to participate in this study.TP was an author of REDS scale, leading Interventional Nephrologist in the centre performing CTC insertion procedure and was responsible for study concept, data collection, analysis and manuscript preparation. ES was a Senior Renal Nurse leading dialysis unit nursing staff and was responsible for REDS scale introduction, quality monitoring and data collection. MK was the Department Director and was responsible for study concept, data analysis and manuscript preparation. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Antimicrobial resistance (AMR) has gained national and international attention. The design and launch of national policy on antimicrobial use and resistance and action plan marked a milestone in Ghana’s commitment to control AMR. These strategies are some outcomes of getting and sustaining AMR issues prominence on government’s agenda. Understanding the agenda setting processes, policy actors involved and policy change is important as this provides insights on how and why policy actors defined and framed AMR issues to sustain its prominence despite the changing priorities of government agenda.To examine the processes of setting and sustaining AMR issues on government agenda, the policy actors involved and resulting outcomes.A qualitative study was conducted and data collected through interviewing twenty-four respondents and reviewing technical working group meeting reports and health sector documents. Data was analysed drawing on Kingdon’s agenda setting framework.Members of a multisectoral technical working group (AMR platform) formed in 2011 constantly built consensus on AMR problem definition, solutions and actively engaged decision makers to mobilise support and interest. The AMR platform members sustained AMR attention and prominence on government’s agenda through the following multisectoral coordination mechanisms: (1) institutionalising AMR platform activities (2) gathering evidence, sharing findings, and supporting research (3) creating awareness and training (4) gaining and maintaining political support. The activities of the AMR platform contributed to three remarkable outcomes and these are (1) maintained network of AMR Champions, (2) design of a national policy on antimicrobial use and resistance in Ghana (1st edition) and national action plan (2017–2021), and (3) Ghana’s hosting of the second Global call to action on AMR.The AMR platform members as influencers concentrated their efforts to move and sustain AMR issues on government agenda. The identified multisectoral coordination mechanisms collectively contributed to agenda setting processes and policy change. The AMR platform engagements are ongoing and it is important the momentum is maintained. As multisectoral coordination and activities are vital especially for AMR ‘One Health’ approach, we hope this paper presents lessons for better understanding of how and why multisectoral groups influence national level agenda setting processes.The online version contains supplementary material available at 10.1186/s42522-021-00051-w. Antimicrobial resistance (AMR) is a public health threat of local, national and international concern , 2. GlobThe design and launch of the national AMR policy and the NAP marked a milestone in Ghana’s attempt to control AMR. These strategies are some of the outcomes of AMR prominence on government’s agenda and demonstrates its’ commitment. Locally, AMR has been researched, discussed, and prioritised at health care facilities level –11. Howethe collaborative efforts of multiple disciplines and sectors -working locally, nationally, and globally - to attain optimal health outcomes, recognizing the interconnection between people, animals, plants and our shared environment’ .Participants constituted a technical working group (the Ghana AMR platform) to create awareness and mobilise the support of health professionals, academia, media, and decision makers. Professional groups and institutions with influence and interest in and affected by AMR were proposed as potential AMR platform members  institutionalising AMR platform activities (2) gathering evidence, sharing findings and supporting research (3) awareness creation, training and advocacy and (4) gaining and maintaining political support.The AMR movement in Ghana started from the public health sector, basically the human health aspect of Antimicrobial resistance. Along the way, the animal health sector was added because we realized that significant use of antibiotics was coming from the livestock area. But with the advent of the ‘One Health’ concept: the tripartite- that is the FAO, OIE and WHO, decided to bring environment also on to the platform’ .‘The AMR platform activities were institutionalised when a governance structure comprising a management team and a secretariat was created by the MoH. The management team comprised of the chair, representatives from the WHO, KNUST, and head of the GNDP. The secretariat organized the AMR meetings and actively recruited new members and maintained existing membership by engaging them through regular meetings. Under the study period, the secretariat organised twenty-one 21) meetings  groupings  were formed and dissolved when the activities were completed (see supplementary Table 9 groupinhttp://ghndp.org/reactghana/ and http://ghndp.org/reactcso/) were developed and regularly updated by the secretariat.To support institutionalisation of AMR activities in Ghana, the MoH, Uppsala University and ReACT signed a contract in August 2012. As a result of this financial support, two coordinators were recruited for the engagement with CSOs and development of the national AMR policy respectively. Additionally, websites , Fleming funded and the Global AMR surveillance systems (GLASS).The AMR platform became a very important source of knowledge for health professionals because research findings were constantly shared and innovative ideas discussed.’ .‘Members regularly shared AMR decisions and activities undertaken in their individual organizations. Additionally, representatives updated members on the following projects: Antibiotic Drug use, Monitoring and Evaluation of Resistance (ADMER), Monitoring Antimicrobial Resistance in Hospital Laboratories (MARHLAB), Healthcare associated infection (HAI), Tricycle ‘People are interested in Ghana’s AMR activities setting the foundation for FAO support and the Fleming fund. This was not just an issue of FAO Ghana but the support came right from the headquarters. Ghana was selected as one of the seven countries offered financial support for AMR work and this is all because of the work done in Ghana’ .Research, training, and funding opportunities were also discussed and members encouraged to apply. Notable were the Fleming funding and fellowship, and the Structured Operational Research Training Initiative (SORT IT) research. On 15th February 2017, a team of the UK Fleming fund country grant mission briefed members on the aims and expectation of the Fleming Fund.One can say that the capacity of various CSOs has been enhanced because of the advocacy and training activities of the AMR platform. Now we are AMR champions and involved in research generating evidence as well as influencing policy’.‘AMR platform members advocated for AMR issues and participated in sensitization programmes to educate the general public and in July 2014 designed and aired an AMR documentary on national television (MultiTV). In addition, training programmes were organised and by October 2014 ninety-one (91) members of CSOs were trained. Community leaders including Queen Mothers and representatives from municipal health directorates in the Central and Western regions were sensitized on AMR. The guide used for the training titled ‘Fighting Antibiotic Resistance in Ghana: Manual for Training Civil Society Organisations’ was developed by the platform members and reviewed by two independent reviewers.‘We learnt from other country examples. We also had the opportunity to further discuss AMR in-country findings at a conference in Istanbul, Turkey. The AMR discussions were kept alive and translated into a national policy’ [Academia 15th May 2019].AMR platform members, also, participated in international meetings. For example, a seven-member delegation from the AMR platform and led by the deputy Minister of Health attended the 1st Global Forum on Antibiotic Resistance conference (3–5 October 2011) in New Delhi, India. The Minister made a presentation highlighting Ghana’s efforts and commitment towards tacking AMR. He was also signatory on a global ministerial communique to preserve the power of antibiotics for future generations. Thereafter, three members of the platform participated in a ReACT CSO project management and implementation meeting in Penang, Malaysia (17–18 February 2012) and a ReACT consultative meeting in Uppsala Sweden (21–22 February 2012). Additionally, two members represented the AMR platform at the ReACT CSO project workshop (November 2012) in Cuenca, Ecuador. The platform chair participated in the 67th and 68th World Health Assembly, the Dag Hammarskjöld Foundation forum in Sweden and ministerial forum in the Netherlands to share Ghana’s efforts to tackle AMR.E.coli study was disseminated at the health sector working group meeting.‘Presenting AMR issues at the health summit and health sector working group meeting were very important because these are the decision-making spaces where strategies are firmed up for the health sector plans and implementation’ .Throughout the study period, the AMR platform engaged with national politicians and key decision makers. The Ministers of Health were constantly briefed of the activities of the AMR platform. On 10th July 2014, the chair of the Parliamentary Select Committee on Health expressed his interest and governments’ commitment to tackle AMR issues after he was briefed on the efforts of the AMR platform. Members also briefed the National Development Planning Commission and contributed to the design of AMR indicators for the country’s long-term plan. Additionally, to demonstrate further support, the GHS Director General participated in the 29 June 2017 meeting. AMR platform members engaged the wider leadership of the health sector as they presented AMR problems and potential solutions at the Health Sector working meetings and the annual Health Summit. As a result, antimicrobial use and resistance was captured as policy strategy in the 2018 health sector Aide Memoire. On October 2, 2019 findings from Tricycle In August 2016, the members briefed the Chief Directors and Ministers of the Ministries of Fisheries, Agriculture, Environment Science Technology and Innovation on the design and different aspects of the AMR policy. During the October 2016 validation workshop for the NAP, the Deputy Minister of Food and Agriculture, and the Senior Policy Advisor to the Chief Veterinary Officer at the FAO Head Quarters, pledged their support to AMR activities in country.Over time, some global AMR actors participated in the AMR platform meetings. For instance, the ReACT global coordinator, global network focal person and a representative from the Africa office participated in AMR platform meetings on 10th May 2012, 11 July 2013 and 23 March 2015 respectively. Prof Otto Cars, founder of ReACT, also participated in the 21 November 2018 meeting to gain a first-hand experience about Ghana’s AMR platform and share knowledge.AMR platform members actions resulted in three remarkable outcomes: (1) maintained network of AMR Champions, (2) design and launch of a national policy on antimicrobial use and resistance in Ghana (1st edition) and its accompanying NAP (2017–2021) and (3) Ghana’s hosting of the second Global call to action on AMR.The AMR platform over time has become a space where decisions are taken. Also the membership increased and it keeps growing because people are showing interest and are passionate about AMR issue. We started with a few people-about 20 and now the platform has about 75 members ’ .‘One, a network of AMR champions formed and maintained as a result of the platform members regular communications of AMR problems, exchange of ideas, policy proposals, research findings and funding opportunities. This allowed for a pattern of collective actions among public and private actors in the fight against AMR.‘Ghana was the first country in Sub-Saharan Africa to launch its national AMR policy and action plan. So Ghana is seen as a leader when it comes to the issue of AMR and this is an output from the AMR platform activities.’.Two, a national policy designed to improve awareness of AMR through effective communication, education and training and strengthen existing knowledge base through surveillance and laboratory services. As well as reduce incidence of infection through infection prevention measures and ensure a balance between access and excess to preserve antimicrobials . Figure Ghana has put together a policy and is no longer confused as to what it wants to do concerning AMR. Ghana is very clear on its intentions on AMR and what interventions should be taken. And that is a huge achievement’ .‘The government of Ghana, Swedish International Development, the World Health Organization, the ADMER project, Ghana, and the Food and Agriculture Organization (FAO), Ghana office provided financial and technical support for the design of the AMR policy and NAP.Ghana has benefited so much since the AMR movement started. The Second Global call to Action conference was held in Ghana on the back of Ghana’s achievements towards curbing AMR menace. Even though we have chalked some success we need to sustain the discussions and consolidate the work done thus far’ .‘Three, the government of Ghana in partnership with the Inter-Agency Coordination Group on Antimicrobial Resistance organised the second call to action on AMR in Ghana in November 2018. The conference brought together diverse stakeholders.The case of AMR national level dialogue and activities illustrates the collective action by stakeholders (champions) in defining and framing AMR problems and solutions and building consensus to set and sustain AMR issues on government agendas. These champions were from diverse sectors, disciplines and jurisdictions with a common goal of highlighting the challenges of AMR and proposing potential solutions. The collective action of these stakeholders depicted the multisectoral approach of the AMR platform. Initially, stakeholders were mainly from the health sector and this gradually changed to include others from animal health, veterinary, husbandry, agriculture, aquaculture and environment were included in line with the ‘One Health’ approach. As a result, the framing of AMR problems and solutions moved beyond health and framed as a threat to all sectors including animal, human, plants and environment. The ‘One Health’ approach later adopted by the AMR platform reflected the Global Health Security Agenda AMR action package which promotes multisectoral engagement and collaboration .Members of the AMR platform from government ministries, research institutions, academia, professional bodies, CSOs and international agencies were actively involved, passionate and participated in discussions to move AMR issues onto government agenda, attract and maintain their interest and develop policies and national action plans for implementation. This is similar to previous works in some selected LMIC settings, where collective actions through multisectoral groups resulted in outcomes such as AMR national action plans and policies , 15, 27.The AMR platform activities thrived in an institutionalised venue managed by the AMR secretariat and management team (governance structure). This venue served as bureaucratic and public decision making space where decisions taken by members were acted upon by responsible organization and sector . GovernmAMR platform membership was open as members actively contributed to the development of the national AMR policy and the NAP. This is however not the case for other policy making venues within the Ghanaian setting. For example, policy decision making in the Parliament and within the health sector business meetings are restricted to individuals with the mandate to participate although the policies are of national interest , 30. TheThe AMR platform as a policy community floated ideas and solutions on strategies to improve AMR awareness, strengthen knowledge and evidence base, reduce incidence of infection, optimise the use of antimicrobial agents and develop an economic case for sustainable investments in new medicines, diagnostic tools and other interventions . These sThe policy change initiated by the AMR platform were driven by the definitions and framing of AMR problems and solutions, this was further advocated by politicians and decision makers. Policy change is complex and multifaceted, and as politicians and decision makers process evidence and solution disproportionately, they choose why and how to act and sustain AMR agenda . The polThis study has a number of limitations. There are potential recall biases as key informants addressed how and why national level AMR movement started and evolved. Additionally, decisions started in AMR platforms meeting reports were recorded as collective decisions masking the details of who said what and how it was received. To mitigate these challenges, we used varied data sources to reconstruct the AMR agenda setting processes and outcomes.These multisectoral coordination mechanisms: institutionalisation of AMR platform activities, gathering and sharing of evidence, awareness creation and advocacy and gaining, and maintaining political support collectively contributed to sustaining AMR issues on government agenda. The AMR platform activities and engagements are ongoing and it is important the momentum is maintained and intensified. As multisectoral coordination and activities are vital especially for AMR ‘One Health’ approach, we hope this study documents lessons that will improve understanding of justification and functioning of multisectoral groups in influencing national level agenda setting processes.Additional file 1. AMR Movement Semi- Structured Interview Guide.Additional file 2. Supplementary Table 1: AMR platform meeting dates and agenda (2011-2019).Additional file 3. Supplementary Table 2: Subgroupings names, objectives and setup dates.


Anentome helena , is a convenient and reliable experimental system to study feeding of a generalist predator on multiple food types which exhibits well-pronounced specialisation of foraging individuals. Using A. helena we experimentally test: (i) how relative prey abundances in the environment affect the feeding patterns, (ii) whether the feeding patterns are consistent over the duration of the experimental period, and (iii) compare the feeding niche breadth of individuals to that of the laboratory population. By offering four different prey snail species, at a range of relative abundances, we show that there are consistent patterns in feeding. Importantly, the consumption of each prey was independent of the relative abundance at which they were present. Individual predators showed selectivity to a particular prey, i.e. the population of assassin snails seems to be formed of individuals that specialise on different prey. Our findings would contribute to the recent revision and the ongoing debate on the classification of predator species into generalists and specialists.Quantifying feeding behaviour of generalist predators at the population and individual levels is crucial for understanding the structure and functioning of food webs. Individual predator/consumer feeding niches can be significantly narrower than that of the population across animal taxa. In such species, the population of a generalist predator becomes essentially an ensemble of specialist individuals and this often highly affects the dynamics of the prey-predator interactions. Currently, few experimental systems exist that are both easily technically manipulated in a lab and are reliable to accurately assess effects of individual specialisation within generalist predators. Here we argue that a freshwater predaceous snail,  Foraging ecology explores how consumer resource uptake is shaped by the biotic and abiotic environment. The knowledge of foraging behaviour of generalist predators is crucial for understanding the functioning of food webs, community dynamics and explaining ecosystem biodiversity –3. WhileNucella emarginata [Clarias gariepinus) was correlated with individual differences in growth [Pyrenestes ostrinus [Perca fluviatilis) niche breath, and thus levels of specialisation, varies with habitat [Generalist predators are those that feed on a range of prey species. However, some obstacles still exist in exploring and understanding the foraging behaviour of generalist predators. First, the perception of resources by a predator can differ from human definitions. Biologically separate species could be treated as a similar resource, or members of the same species could be seen as different . If diffarginata . Third, arginata . Indeed,arginata . This caarginata , 13. Forn growth . In red n growth . Furthern growth  and a trostrinus . We can ostrinus , and theostrinus . Finallyostrinus , for ins habitat .Anentome helena as a convenient system to further explore foraging patterns of a generalist predator feeding on multiple resources, and the potential for individual feeding niche separation.Apart from some well-studied systems , 21, 22,A. helena (von dem Busch in [Clea helena) is a fresh water snail [A. helena is native to many areas in Southeast Asia, and recently range expansion has been reported, showing its invasive potential [Busch in , Nassarier snail , 28. It er snail , 30. It er snail . For thier snail , as a sper snail . A. heleotential . SurprisA. helena to test a number of hypotheses. First, we test how prey relative abundances affect feeding electivity of A. helena snails. Second, we test whether any patterns in electivity of prey are consistent over time. Third, we compare diet breadth of individual A. helena to that of the laboratory population. Finally, based on these results we evaluate the suitability of A. helena as a system to study predator-prey interactions, specifically regarding the niche breadth of individual predators. We expect that individuals exhibit a consistent, but narrower feeding niche than the population as a whole. This will result in stable differences in feeding electivity.In this paper we use All snails stocks (predator and prey) were obtained from a local aquarium shop (Leicester Aquatics). In experiments predators and prey from a mixture of first and second (lab bred) generation snails were used. Snails used in the experiment were never used for breeding afterwards.A. helena assassin snails (A. helena to bury themselves [n snails  were houemselves  and was emselves . All snaA. helena in each tank were fed by placing a cube of frozen blood worms (Chironomidae) at the bottom of the stock tank. A. helena snails readily consumed this and were fed on blood worms for at least three weeks before the start of the experimental trials. This was done to remove any pre-existing behavioural adaptation (e.g. more efficient handling), as well as to prevent the development of a preference for one prey species. Preferences can develop over time in some predaceous snails [During the pre-experimental period, s snails , 35.A. helena in its natural habitat, little is known about the diet in the wild. We therefore picked prey species that are common in the aquarium trade and originating from Southeast Asia; Ramshorn snails (Planorbella sp.), Malaysian Trumpet snails (Melanoides tuberculata), Pond snails (Lymnaea sp.), and Quilted melania snails , instead of sand, was added to the bottom to serve as a biological filter. A small amount of washed, crushed sea shells was added, to stabilise pH and calcium availability for growing snails. Aeration was supplied through air stones and snails were fed on a mixture of lettuce, and commercial fish food . Prey selection by predators can be based on nutrient compositions of prey diet [Prey snail species were maintained in a similar way to rey diet , 37, so −2, which falls within the range of densities in the natural habitat [For feeding experiments, four large tanks 60 x 40 x 40 cm) were subdivided with dividers into 10 (2 rows of 5) compartments each. Each compartment measured ∼11 by 19 cm and was filled with 6 cm of water . Circa 1.5 cm of depth (250 mL) of white, fine (ø 5–7 mm) crystalline gravel was added to each compartment to allow for natural burrowing behaviour of snails . With 8  habitat , 39. Wat x 40 cm A. helena snails were used to investigate the background prey mortality. It was also checked that all prey species were consumed, i.e. that all prey species were recognised as such, and whether there were any differences in total consumption between treatments as this could have implications for the electivity. To standardise hunger levels between A. helena snails, they were starved between 3 and 7 days before trials [Five different experimental treatments were carried out. Each treatment used 8 prey individuals out of the four prey species. Initial trials were carried out with equal relative prey abundances . Later, four different prey relative abundance treatments were tested in haphazard order (details on starting dates available in the data set); 1:2:1:4 (n = 31), 1:3:2:2 (n = 10), 2:1:4:1 (n = 12), and 4:2:1:1 (n = 17). Not all treatments could be run simultaneously, because of availability of prey snails and space constraints. Different numbers of replicates for the different treatments were obtained due to prey snail availability. A single treatment was tested in a tank at the same time. During most trials, one or two control treatments with the same relative abundances of prey snails, but without e trials . For praA. helena snail was tested for 14 consecutive days. For one chosen treatment (1:2:1:4), we ran trials for 28 days, to monitor potential shifts in feeding behaviour over the duration of the experimental period. The consumption by each A. helena snail was recorded every 24 hours by counting empty shells of prey snails. Then, all prey snails and empty shells were removed and replaced with new prey snails at the same starting relative abundances. Live prey were returned to holding tanks and fed. These prey snails could then be used again in the same trial (i.e. the same treatment with the same A. helena snails), in compliance with the 3R’s  used in the experiment. This amounted to small (10–15%) differences in length within species. All predators were offered a similar range of prey sizes to make food abundance as equal as possible. Preliminary experiments had shown that this leads to a steady feeding rate, whilst minimising the consumption of more than one prey by a single A. helena snail in a day and consequently affecting prey relative abundances in a given compartment. At the end of each trial all prey and predators were removed and not used again.Feeding by each  Refine’ ). All prglmmTMB [multicomp [anova function [Anova [DHARMa package [ggplot2 [png [reshape2 [purrr [dplyr [All calculations and statistical analyses were carried out in R  using R-glmmTMB . Compariulticomp  with a Tfunction . The Ano[Anova  function package . The out package ). Figure[ggplot2 , and pngot2 [png . For datreshape2 , purrr [2 [purrr  and dplyr [dplyr  were alsA. helena snails that fed at least 3 times during the two week experimental period were included in the analyses. The total consumption per A. helena was compared between treatments to test for the effect of treatment on willingness to feed. Consumption was compared using GLMM’s. Throughout the analyses Poisson and Conway-Maxwell-Poisson error distributions were used, based on appropriateness and model fit.Only A. helena snail the Manly-Chesson α electivity index was calculated for each prey species each day [ri is the proportion of prey item i consumed by the predator and pi is the proportion (relative abundance) of the same prey type in the treatment. Although it is hard to statistically show absolute prey preferences using this index [For the overall preference of each each day , 57, accis index , it is pis index , 59.A. helena snail, the electivity index for each experimental day on which it fed was calculated and averaged over all feeding days . When sin [nnet . Within als . If in als . If. IfA. heW [i) against the population, is suitable for discrete consumption, and its statistical properties are known [Wi values and significance were calculated using the RInSp package [Diet breath of individual predators was compared to that of the population using Petraitis’ index W . This inre known , 62. Thi package .χ2 = 1.824, P = 0.610), removal of the random effect did not affect model fit . The model had a good fit to the data  over 121 experimental days . A total of 778 prey snails were predated upon over 1485 experimental days . The baGLMMCOM − Poisson;χ2 = 16.319, df = 4, P = 0.003; A. helena snails consumed more prey in the 2:1:4:1 treatment compared to the 1:3:2:2  and 2:2:2:2  treatment. The model with the best fit included ‘experimental day’ as random effect , besides the other random effects for predator individual  and position in the experimental tank . Note that in 308 cases all individuals of one available prey species were consumed, but only in 31 (≈10%) of those cases another prey was eaten. In the latter A. helena may have been ‘forced’ to consume a non-preferred prey species.After removal of snails that fed less than three times (n = 9), total consumption over the two week period of individual predators (feeding success) did vary significantly between treatments . So the final model included predator ID and compartment nested within tank as random effects. There were overall differences in the consumption of the prey species . Ramshorn snails were more consumed than the other species and Trumpet snails less consumed (In the 1:2:1:4 (Quilted melania snails most abundant) treatment adding experimental day did not improve model fit . Here, Ramshorn snails were more consumed than the other species, but there were no further differences between the consumption of the different prey types  treatment the GLMM with the best fit also included experimental day as a random effect . Ramshorn snails again were the most likely prey to be consumed, closely followed by Quilted melania snails (In the 2:1:4:1 (Pond snails most abundant) treatment, no additional random effects were included in the best model . Again, Ramshorn were more likely to be consumed than the other prey species, and between the other species there were no differences . Here, there were significant differences in consumption again . Trumpet snails were consumed less than any other prey species and Pond snails were consumed less than Ramshorn snails (In the 4:2:1:1 (Ramshorn snails most abundant) treatment, the best model did not include any additional random effects  and Trumpet the least and negatively selected against (Manly-Chesson α: 0.01–0.14).Overall, prey species appeared to be consumed by z < 1.573, P > 0.116; A. helena at this life stage.For the extended trials we found that overall, there were no differences between weeks in preference , and the total consumption . There were no differences between treatments . We found that 94 out 97 A. helena snails had ≥50% of a particular prey in their diet (A. helena snail (from 4 to 14).We explored the individual feeding preference of each ironment . The proeir diet . MoreoveP-values (42 − 76%) associated with the calculated Petraitis’ Wi values were smaller than 0.05 and indicated that the diet breadth of an individual was narrower than that of the population  to A. helena. In coyotes, on the other hand, individual diets seem highly similar (mean W = 0.8), even between different social groups [A. helena individual specialisation showed a wide range of values  that feeding of individual predators was consistent over time. We further showed (iii) that most individual predators had a narrow feeding niche, whereas at the level of population, prey selectivity is less pronounced. Based on the above findings we conclude that (iv) A. helena can be a promising system to study relationships between individual and population diet niche breadth. Our results highlight apparent challenges in defining a generalist predator species depending on organisation level: individual or that of the whole population.To conclude, in this study, we found (i) that regardless of prey relative abundance feeding of S1 Figα (±95% CI) of each prey type in each treatment (a-e) based on feeding without depletion. The prey abundance in a particular treatment is indicated in the label of each panel . In the case where the confidence interval overlaps with the dashed line (expected feeding under random prey selection) there is no selective feeding on a prey species.Mean (PNG)Click here for additional data file.S1 TableNote that the number of replicates differs per treatment, the number of replicates per treatment can be found in (CSV)Click here for additional data file.


Dopamine is used to treat patients with shock in intensive care units (ICU) throughout the world, despite recent evidence against its use. The aim of this study was to identify the latest practice of dopamine use in Japan and also to explore the consequences of dopamine use in a large Asian population.The Japanese Intensive Care PAtient Database (JIPAD), the largest intensive care database in Japan, was utilized. Inclusion criteria included: 1) age 18 years or older, 2) admitted to the ICU for reasons other than procedures, 3) ICU length of stay of 24 h or more, and 4) treatment with either dopamine or noradrenaline within 24 h of admission. The primary outcome was in-hospital mortality. Multivariable regression analysis was performed, followed by a propensity score-matched analysis.N = 28) and infrequent users (N = 28). Patients receiving dopamine had more cardiovascular diagnosis codes , more post-elective surgery status (60% vs. 31%), and lower APACHE III scores compared to patients given noradrenaline alone . Multivariable analysis showed an odds ratio for in-hospital mortality of 0.86 [95% CI: 0.71–1.04] in the dopamine ≤ 5 μg/kg/min group, 1.46 [95% CI: 1.18–1.82] in the 5–15 μg/kg/min group, and 3.30 [95% CI: 1.19–9.19] in the > 15 μg/kg/min group. In a 1:1 propensity score matching for dopamine use as a vasopressor (570 pairs), both in-hospital mortality and ICU mortality were significantly higher in the dopamine group compared to no dopamine group , as well as ICU length of stay .Of the 132,354 case records, 14,594 records from 56 facilities were included in this analysis. Dopamine was administered to 4,653 patients and noradrenaline to 11,844. There was no statistically significant difference in facility characteristics between frequent dopamine users (Dopamine is still widely used in Japan. The results of this study suggest detrimental effects of dopamine use specifically at a high dose.Trial registration Retrospectively registered upon approval of the Institutional Review Board and the administration office of JIPAD.The online version contains supplementary material available at 10.1186/s13054-022-03960-y. Since Goldberg et al. reported that administration of dopamine to patients with end-stage congestive heart failure resulted in increased cardiac output and sodium diuresis , dopaminSince 2012, following an epoch-making SOAP II study in 2010 and a subsequent meta-analysis, the Surviving Sepsis Campaign Guidelines continued to recommend noradrenaline as the drug of choice and recommend dopamine “only in highly selected patients   and mostGiven the risks associated with dopamine administration discussed elsewhere, there is an urgent need to evaluate the current situation of dopamine use so that appropriate measures can be taken. In addition, it would also be important to explore the consequences of dopamine use in a large Asian population, which is never reported in the past. This retrospective analysis of the largest database of critically ill patients in Japan was conducted to identify current patterns of dopamine use and also to explore the consequences of dopamine use in this population.This study was approved by the Institutional Board Review at our institution as well as the administration office of the Japanese Intensive Care Case Database (JIPAD) . JIPAD iInclusion criteria included: 1) age 18 years or older, 2) admitted to the ICU for reasons other than procedures, e.g., central line insertion, 3) ICU length of stay of equal to or more than 24 hours, and 4) use of either dopamine or noradrenaline during the first 24 hours of ICU stay. Patients fulfilling all the above criteria were included for analysis. The exclusion criterion was the presence of missing data required for multivariable analysis.N = 28) and dopamine-infrequently using facilities (N = 28) based on the percentage of patients treated with dopamine with a cut-off at the median value. Stacked bar plots for facilities were made for all patients to visualize the proportion of patients treated with dopamine only, dopamine + noradrenaline, and noradrenaline only. The primary outcome was in-hospital mortality. The secondary outcomes were death at the time of ICU discharge, ICU length of stay, hospital length of stay, and duration of the first episode of mechanical ventilation.Participating facilities were classified into two groups: dopamine-frequently using facilities , days before ICU admission after hospital admission, cardiac arrest leading to that ICU admission, activation of Rapid Response Team / Medical Emergency Team leading to that ICU admission, date / time of ICU admission / discharge, the reason for ICU admission  admission through the emergency room, 3) ICU admission following elective surgery, 4) admission following urgent surgery, and 5) other), diagnosis text, diagnosis code, Glasgow Coma Scale, the maximum serum lactate level during the first 24 hours of ICU admission, maximum / minimum laboratory values during the first 24 hours after ICU admission, the maximum value of serum bilirubin, and minimum value of platelet count, urine output during the first 24 hours after ICU admission, acute kidney injury / mechanical ventilation during the first 24 hours after ICU admission, APACHE III, SAPS II score, SOFA score, use of dopamine / dobutamine / adrenaline / noradrenaline during the first 24 hours of ICU admission, date / time of initiation and discontinuation of mechanical ventilation, ICU discharge outcome, hospital discharge outcome , and readmission to the ICU. Other data elements are presented in Additional file Continuous variables were presented with a mean (± standard deviation) and median (interquartile range) as appropriate. Categorical variables were reported with a number (%). For a two-group comparison, statistical significance was tested with an t-test for the continuous variables and a Chi-square test for the categorical variables. For a three-group comparison, a one-way ANOVA test was conducted for the continuous baseline variables and the Kruskal–Wallis test was conducted for the categorical variables. The baseline characteristics of patients were presented in a three-group comparison of dopamine, dopamine + noradrenaline, and noradrenaline in one table, while a two-group comparison of dopamine  vs noradrenaline was also conducted for an easier interpretation.A univariable logistic regression and subsequent multivariable logistic regression analysis with a generalized estimating equation were conducted to assess the effect of dopamine use on the primary outcome utilizing “gee” package in R, accounting for differences in practice among the facilities. The primary predictor variable was a categorical variable representing 1) dopamine only, 2) dopamine and noradrenaline, and 3) noradrenaline only. The variables used for an adjustment in the multivariable analysis consisted of: age, gender , comorbidities, days before ICU after hospital admission, cardiopulmonary resuscitation, the reason for ICU admission (others as reference), diagnosis code, APACHE III, the maximum lactate level at baseline, mechanical ventilation at baseline, AKI at baseline, dobutamine use, and adrenaline use. In the generalized estimating equation models, the dopamine variable was treated as a categorical value with four levels including:1) no use, 2) equal to or less than 5 μg/kg/min, 3) more than 5 but equal to or less than 15 μg/kg/min, and 4) greater than 15 μg/kg/min. The predictor variables in the model were selected by the study team based on their clinical importance, especially when the variables were previously reported to predict outcomes in critically ill patients including postoperative state , admissiTo examine the specific effect of dopamine on the primary and the secondary outcomes, a propensity score-matched analysis was conducted with “Matching” package in R. To account only for the situations where dopamine was used as a vasopressor, not as an inotrope, only patients who received a vasopressor-equivalent dose of dopamine were attempted to be included. Due to unavailability of the exact dose of catecholamines for each patient due to the data entry format in JIPAD, patients in the medium and high dopamine dose categories (5–15 μg/kg/min and > 15 μg/kg/min) were included in the propensity score matching. The propensity scores for dopamine administration were calculated for study patients using a logistic regression model with the generalized estimating equation. The variables used to calculate propensity scores for treatment with dopamine are presented in the Additional file To explore the effects of dopamine on the outcomes of patients with cardiovascular disease or infection, pre-planned subgroup analyses for the propensity-matched cohorts were conducted using data from patients with a newly assigned, dichotomized primary disease code of 1) cardiovascular, 2) infection, or 3) other (neither 1 nor 2).p-value of 0.05  was considered statistically significant. All statistical analyses were conducted with R version 4.0.2 .A Figure The characteristics of the participating 56 facilities are presented in Additional file p < 0.01). Cardiovascular diagnosis codes were more prevalent in the dopamine group than the noradrenaline only group. Infection diagnosis codes were more prevalent in the noradrenaline only group than the dopamine group . The highest APACHE III and SAPS II during the first 24 hours were higher in the noradrenaline only group than the dopamine group . Baseline vital signs and laboratory data are presented separately in Additional file In total, 132,354 patient records dated from 2015 to 2020 were available, with 14,594 included in this analysis  0.39 (95%CI: 0.31–0.51) for dopamine ≤ 5 μg/kg/min, OR 1.39 (95%CI: 1.11–1.73) for dopamine > 5 and ≤ 15 μg/kg/min, and OR 4.87 95%CI: 2.85–8.34) for dopamine > 15 μg/kg/min (no use as reference). The results of multivariable logistic analysis with the generalized estimating equation are shown in Table .85–8.34 . The primary and secondary outcomes in these two groups are presented in Table A propensity-matched analysis was conducted on the data after the inclusion process. The area under the receiver operating characteristic curve of the final model to predict the dopamine treatment was 0.73 [95%CI: 0.71–0.75]. In total, 570 pairs were made upon a 1:1 propensity score matching. The baseline characteristics of the pairs are presented in Table These results showed that dopamine is widely used in ICUs in Japan, most commonly for patients with cardiovascular diseases. There were no significant differences in hospital characteristics between dopamine frequent-using facilities compared with infrequent-using facilities. Importantly, a dopamine dose > 5 μg/kg/min was associated with a higher probability of in-hospital mortality in a dose-dependent manner in multivariable analysis. The propensity score-matched analysis excluding those who received ≤ 5 μg/kg/min showed a significantly higher risk of death at ICU discharge or hospital discharge with dopamine use as a vasopressor. Furthermore, this analysis also showed a longer ICU stay by almost two days and a longer duration of the first mechanical ventilation by one day in the dopamine group. While a subgroup analysis showed no difference in the primary outcome associated with dopamine use in any disease categories, a significantly longer ICU stay and the duration of the first mechanical ventilation were noted with dopamine use among the patients with cardiovascular diseases.As stated in the Surviving Sepsis Campaign Guidelines 2016, the literature on the treatment of shock after 2010—when the landmark Sepsis Occurrence in Acutely Ill Patients (SOAP) II trial was published—does not support dopamine use in treating patients with shock in general , 12, 31.practice. The odds ratio for the hospital mortality for the low dose dopamine in the current study was lower than those for higher dose groups in the multivariable analysis  used likely as an inotrope at a low dose (less than 5 μg/kg/min), which suggests the prevailing notion of the renal-protective effects of dopamine among physicians as of 2018–2019. While low-dose dopamine was initially expected to induce natriuresis in patients with end-stage congestive heart failure through vasodilation, the benefits of low-dose dopamine on patient outcomes were subsequently refuted in many studies. The landmark randomized controlled trial conducted by the Australian and New Zealand Intensive Care Society  , 35, 36.This is the largest study that assessed dopamine use and its consequences in ICUs from a single Asian country, utilizing the largest domestic critical care registry (JIPAD) in Japan. However, there are certain limitations to the present study, other than the usual limitations implicit in a retrospective study. First, patients with missing data needed for multivariable models were excluded, which might introduce selection bias. Specifically, albumin, platelet, and bilirubin variables had many missing values, leading to exclusion of these variables from the multivariable models. Second, there were no data regarding tachycardia or cardiac arrhythmias, unlike previous studies which used arrhythmias as an outcome. The available heart rate data were maximum and minimum heart rate only during the first 24 hours, which were presented as baseline data. Third, the context in which dopamine was used might not be appropriately reflected in the diagnosis code. Specifically, post-operative cardiogenic shock and post-operative vasodilatory shock were difficult to differentiate from the diagnosis codes only. Due to this problem, the specific indication for dopamine use was unclear, expecting either a renal-protective effect, vasopressor effect, or both. Fourth, the exact doses and duration of each catecholamine were not available—which might be one of the common but significant limitations of any databases requiring manual data entry. Any catecholamine requirement outside of the first 24 h window was thus not perceived in the current study. It should also be noted that the patient population in the present study seemed to be less acutely ill when compared to previous cohorts such those as in the SOAP  or SOAP To the best of our knowledge, this is the largest study to describe dopamine use in patients in the intensive care unit after the SOAP II trial, utilizing a domestic database administered by the Japanese Society of Intensive Care Medicine. Dopamine was found to be used widely as of 2018–2019, most notably in patients after cardiac surgery and at a low dose. Dopamine use was associated with poor clinical outcomes in patients in this study, similar to the results of previous studies, supporting the need to change clinical practice for the use of dopamine.Additional file 1. Supplementary data. Data elements in the original data set (other than noted in the manuscript). Variables included in the generalized estimating equation model for propensity score. Supplemental Table 1. Baseline characteristics of hospitals stratified by frequency of dopamine use. Supplemental Table 2. Baseline vital signs and lab values, stratified by dopamine and noradrenaline use. Supplemental Table 3. The baseline vital signs and lab values of propensity-matched groups for dopamine use.


The quantity of herbicides adsorbed using BS1000 was greater than that using either BS or medicinal-grade carbon. Additionally, the adsorption quantity increased with the increase in contact time and initial concentration of herbicide. Therefore, BS1000 is a potential resource for the removal of herbicides. Moreover, BS and BS1000 exhibited the capacity for herbicide adsorption in simulated intestinal fluid.Raw and calcined basil seeds  were evaluated for their ability to remove herbicides such as paraquat and diquat. The physicochemical properties of BS and BS1000 were determined and the effects of contact time and initial concentration on paraquat and diquat adsorption were assessed. After calcination treatment, the number of pores in BS increased, and the specific surface area was increased from 0.265 to 86.902 m •Calcined basil seed (BS1000) showed the adsorption capability of herbicides.•Binding energy of carbon onto BS1000 surface increased after adsorption.•Herbicides were removed using BS1000 from simulated intestinal fluid. Basil seed, Paraquat, Diquat, Adsorption In particular, Goal 7 (Affordable and clean energy) and Goal 12 (Responsible consumption and production) aim to develop useful recycling technologies for reducing wastes globally . Increas50) values of paraquat and diquat were reported in the concentration of 150 mg kg−1 and 231 mg kg−1, respectively  is a common and well-known herb  and diquat dibromide monohydrate standard (C12H12Br2N2•H2O) were purchased from FUJIFILM Wako Pure Chemical Co., Japan. The commercial product (7% diquat dibromide +5% paraquat dichloride) was obtained from Syngenta Co., Ltd., Japan. Concentrations of paraquat and diquat were measured using previously reported methods (Raw basil seed (BS) and medicinal carbon (MC) were obtained from Thai Cereal World Co., Ltd. (Thailand) and Nichi-Iko Pharm. Co., Ltd. (Japan), respectively. Calcined BS at 1000 °C (BS1000) was prepared by the carbonization of BS . Paraqua methods . MoreoveC min−1. The sample surface characteristics such as specific surface area and pore volume were measured using a specific surface area analyzer , based on nitrogen adsorption/desorption at liquid nitrogen temperature. In addition, the surface functional groups and the pH point of zero charge (pHpzc) were determined using the method reported by The physicochemical characteristics of the prepared tested samples were determined using the following methods. The morphology of the tested samples were determined using a scanning electron microscope , with 5 μm of a beam diameter and 15 kV of voltage. The thermogravimetric-differential thermal analysis was conducted using a thermal gravimetric differential thermal analyzer  under atmospheric air, with a temperature elevation rate of 10 °2.2−1 of paraquat or 70 mg L−1 of diquat solution in the volume of 50 mL, and then shaken at 100 rpm and 25 °C for 24 h. After adsorption, the tested samples were separated from a reaction mixture using a 0.45 μm membrane filter. The obtained filtrate was quantified and calculated for pesticides adsorbed, which comparable between before and after adsorption. In addition, the same experiment was repeated using a binary solution system (50 mg L−1 paraquat and 70 mg L−1 diquat).The removal of each pesticide using BS, BS1000, and MC was evaluated. Briefly, 0.05 g of each adsorbent was mixed with either 50 mg L2.3−1 of paraquat or 70 mg L−1 of diquat solution in the volume of 50 mL, and then shaken at 100 rpm and 25 °C for 0.5, 1, 1.5, 2, 3, 4, 5, 6, 20, and 24 h. Subsequently, to evaluate the effect of concentration, 0.05 g of each tested adsorbent and 50 mL of either paraquat or diquat solution were mixed at different initial concentrations, and then shaken at 100 rpm and 25 °C for 24 h. The quantity of each pesticide adsorbed was calculated using the method described in Section Initially, to evaluate the effect of contact time, 0.05 g of each tested adsorbent was mixed with either 50 mg L2.4th Japanese Pharmacopoeia (−1 paraquat (or 70 mg L−1 diquat) in simulated intestinal fluid were mixed, and then shaken at 100 rpm and 25 °C for 24 h. The quantity of each pesticide adsorbed was calculated based on the method described in Section First, simulated intestinal fluid was prepared for the disintegration test using the method reported in The 17acopoeia . This te33.12 g−1 on specific surface area of BS1000 was higher than that of BS (0.265 m2 g−1), and the concentration of surface functional groups of BS1000 (0.193 mmol g−1) was lower than that of BS (0.655 mmol g−1). These results are consistent with those mentioned earlier. In comparison, the specific surface area of MC was significantly greater than that of either BS or BS1000. However, the numbers of micropores were comparable to those of BS and BS1000 under the current conditions. The pH point of zero charge (pHpzc) is pH value at which the surface charge components become equal to zero under given conditions  was similar to or greater than that using other reported adsorbents (7.5–30 mg g−1). In addition, the adsorption capability of diquat using BS1000 was also greater than that using other reported adsorbents (except for OMWCNT and pristine g–CN–0.3). Therefore, BS1000 would be a potential candidate agent for the removal of herbicides such as paraquat and diquat from aqueous media.The comparison of paraquat and diquat adsorption capability of tested bio-adsorbent including BS, BS1000, and other reported adsorbents is shown in To elucidate the one of the adsorption mechanisms of paraquat and diquat using BS and BS1000, the elemental distribution and binding energy on the surface of each BS and BS1000 before and after adsorption were evaluated in this study as exhibited in Figures 3.3To elucidate the effect of contact time, the changes in adsorption capability of herbicides with contact time using BS and BS1000 were evaluated . It was qe (mg g−1) is the quantity of adsorbed herbicides at equilibrium, qt (mg g−1) is the quantity adsorbed at time t, k1 (h−1) is the overall constant in the pseudo-first-order model, and k2 (g mg−1 h−1) is the pseudo-second-order adsorption constant.The pseudo-first-order equation , qmax is the maximum quantity of herbicides adsorbed (mg g−1), and Ce is the equilibrium concentration (mg L−1). The removal capacity and strength of removal are KF and 1/n, respectively. Additionally, KL is the Langmuir isotherm constant (binding energy) (L mg−1).The adsorption isotherm models are represented through mathematical expression . The relqmax value in BS1000 was greater than that in BS for each herbicide. These trends were consistent with the adsorption isotherm data presented in n value is 0.1–0.5, the adsorption of herbicides occurs easily; in contrast, when 1/n values are above 2, adsorption of herbicides is difficult. In this study, the 1/n value ranged from 0.1 to 0.7, indicating that the removal of paraquat and diquat using BS and BS1000 is useful  derived from herbicides was detected at approximately 280 eV after adsorption. These results aid in the elucidation of likely adsorption mechanisms, and the use of basil seed waste biomass as a potential resource for the removal of herbicides in an Yugo Uematsu: Performed the experiments; Analyzed and interpreted the data; Contributed reagents, materials, analysis tools or data; Wrote the paper.Fumihiko Ogata: Conceived and designed the experiments; Analyzed and interpreted the data; Contributed reagents, materials, analysis tools or data; Wrote the paper.Noriaki Nagai, Chalermpong Saenjum & Takehiro Nakmura: Performed the experiments; Contributed reagents, materials, analysis tools or data.Naohito Kawasaki: Conceived and designed the experiments; Contributed reagents, materials, analysis tools or data.This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.Data included in article/supplementary material/referenced in article.The authors declare no conflict of interest.No additional information is available for this paper.