Feng Li, Hua Cui, Xiang‐Qin Lin

Luminescence • 2002

Abstract The electrogenerated chemiluminescence of Ru(bpy) 3 2+ /C 2 O 4 2− system on a pre‐polarized Au electrode was studied using a potential‐resolved electrochemiluminescence (PRECL) method. Two anodic ECL peaks were observed at 1.22 V (vs. SCE) (EP1), 1.41 V (vs. SCE) (EP2), respectively. The effects of the concentration of oxalate and Ru(bpy) 3 2+ , adsorbed sulphur, CO 2 , O 2 , pH of the solution and pretreatment of the Au electrode on the two PRECL peaks were examined. The surface state of the pre‐oxidized gold electrode was also studied using the X‐ray photoelectron spectroscopy (XPS) technique. Moreover, comparative studies on i–E and I–E curves were carried out and a possible mechanism involving both the catalytic and the direct electro‐oxidation pathways was proposed for the ECL of Ru(bpy) 3 2+ /C 2 O 4 2− system. EP1 is attributed to the Ru(bpy) 3 2/3+ reaction catalysed by C 2 O 4 2− to generate Ru(bpy) 3 2+* . EP2 is likely because C 2 O 4 2− was oxidized at the electrode to form CO 2 −· , followed by reaction with Ru(bpy) 3 3+ to generate Ru(bpy) 3 2+* . Copyright © 2002 John Wiley & Sons, Ltd.

Ola G. Hussein, Yasmin Rostom, Amr M. Mahmoud et al.

Current Analytical Chemistry • 2025

Background: Traditional analysis techniques usually involve separation and pre-treatment steps prior to analysis, resulting in time and solvent consumption. In contrast, a potentiometric ion selective electrode is a simple, environmentally friendly, and cost-effective technique that is used as an alternative analytical technique, utilizing the efficacy of potentiometric sensors used in stability research and quality control investigations. Methods: An innovative Antazoline selective membrane sensor was constructed and evaluated to detect Antazoline in its pure form, eye drop formulations, degradation products, and biological fluid. Sensor fabrication was achieved using potassium tetrakis borate and polyvinyl chloride polymeric matrix plasticized with 2-nitrophenyl octyl ether and using calix[8]arene (CX8) as an ionophore. A comparative potentiometric study was implemented using two sensors, one using an ionophore and the other lacking the ionophore. Results: Linear responses of Antazoline were obtained utilizing sensors 1 and 2 in concentration ranges of 1.0×10-2 to 1.0×10-7 mole/L and 1.0×10-2 to 1.0×10-6 mole/L, correspondingly. Nernstian slopes of 58.486 and 51.2 mV/decade over pH 8.0 were attainted using 1 and 2 sensors, respectively. Conclusion: The proposed method was applied to determine antazoline without any need for any pretreatment or separation steps in both formulated eye drops Trillerg® sterile ophthalmic solution and Otrivine- Antistin® Eye Drops as well as in rabbit aqueous humor and the presence of its degradation products. Estimation of the method's greenness was confirmed using several assessment tools.

Shumin Liu, Jia Chen, Jinpeng Sun

Frontiers in Computing and Intelligent Systems • 2023

According to the good conductivity and electrocatalytic activity of multi-walled carbon nanotubes (MWCNTs) and the hydrogel properties of polyvinyl alcohol (PVA), MWCNTs and PVA double-network porous hydrogels were designed. MWCNTs/ PVA conductive hydrogels were prepared by electrophoretic deposition (EPD) and freeze-thaw cyclic crosslinking process. The electrochemical performance and microstructure of MWCNTs/PVA electrode film showed that MWCNTs/PVA hydrogel electrode film has a highly hydrophilic porous conducting hydrogel network structure. Although MWCNTs/PVA hydrogel electrode film has no obvious catalytic activity on glucose in PBS solution. However, it has obvious catalytic activity on dopamine and ascorbic acid.

Abbas Hassan Oghli, Esmaeel Alipour, Mojtaba Asadzadeh

RSC Advances • 2015

We developed a simple and reliable sensor for the determination of methamphetamine without expensive and time-consuming pretreatments using PPGE.

Ivan Sekerka, Josef F Lechner

Journal of AOAC INTERNATIONAL • 1978

Abstract The chloride ion selective electrode is used for a rapid, simple, and reliable determination of chloride ion in biological materials (blood serum, urine, fish, and plant tissues), food products (milk, beef extract, nutrient broth and orange, tomato, and grapefruit juices), soils, and waste water (industrial and municipal). The method consists of treating the samples with perchloric acid (pH 1) and potassium peroxydisulfate and determining the chloride content either by a calibration curve or by known addition or analyte addition, using the chloride ion selective electrode. Such sample treatment eliminates most of the interferences occurring in the samples, including iodide, complexing and reducing compounds, and macromolecular and surface-active species. The method is suitable for a wide range of chloride concentration, e.g., 5010 ppm CI in nutrient broth and 4890 ppm in beef extract and as low as 12 and 80 ppm in soil extracts.

Letters in Applied NanoBioScience • 2024

The possibility of the electrochemical determination of poisonous mushroom toxins psilocin and coprine on CoO(OH)-modified electrode has been evaluated theoretically. The analysis of the correspondent mathematical model confirms the efficiency of the electrochemical sensor for detecting both mycotoxins in mushrooms and biological liquids for either investigation or diagnostic purposes. The linear dependence between the concentration of both of the analytes is established in a wide concentration range, providing an excellent analytical signal interpretation.

, Siriwan Nantaphol

• 2016

In this dissertation, analytical method/devices based on electrochemical detection are described for determining the important compounds/biomarkers in pharmaceutical and medical diagnostic applications, which can be separated into five parts. In the first part, electrochemical method for N-acetyl-L-cysteine (NAC) detection in drug formulations was developed using boron doped diamond (BDD) sensor coupled with flow injection analysis (FIA) system. The proposed method offers a linear range of 0.5 − 50 µmol/L, a limit of detection (LOD) of 10 nM, excellent response precision, and high stability. In the second part, an electrochemical cholesterol sensor was developed using silver nanoparticles modified glassy carbon electrode (AgNPs/GCE). Hydrogen peroxide (H2O2) produced from the enzymatic reaction was monitored for indirect cholesterol quantification. AgNPs showed the catalytic activity of H2O2 reduction, with no observed interference from easily oxidizable species. The proposed method displayed wide linear range of 3.87 - 773.40 mg/dL with LOD of 0.99 mg/dL. In the third part, a selective non-enzymatic glucose sensor was successfully developed using bimetallic Pt/Au modified BDD electrode. Pt/Au nanocatalyts possess high electrocatalytic activity for glucose oxidation in physiological conditions. A linear range of 0.01 -7.5 mM and a LOD of 0.01 mM were obtained. In the fourth part, a silver nanoparticle-modified boron-doped diamond (AgNP/BDD) electrode coupled with paper-based analytical devices (PADs) was developed for cholesterol detection. Cholesterol and cholesterol oxidase (ChOx) were directly drop-casted onto the hydrophilic area of PAD followed by monitoring of H2O2 from the enzymatic reaction using chronoamperometry. A linear range and a LOD were obtained at 0.01 - 7 mM and 6.5 uM, respectively. In the final part, the disposable boron doped diamond paste electrodes (BDDPEs) for microfluidic paper-based analytical devices (µPADs) were developed and employed for two applications; the quantitative detection of norepinephrine (NE) and serotonin (5-hydroxytryptamine, 5-HT), and the anodic stripping voltammetry of heavy metals. In case of biological species, the electrochemical paper-based analytical device (ePAD) was capable of simultaneously detecting NE and 5-HT in concentration ranges of 2.5−100 µM and 0.5−7.5 µM, respectively. For heavy metal quantitation, a flow-through µPAD design using square-wave anodic stripping voltammetry (SWASV) to enhance the efficiency of metal deposition was presented, thereby improving the detection sensitivity compared to a static ePAD system. The results demonstrated that all proposed method/sensors provide high sensitivity, selectivity, low cost, and portability.

J. Plegaria, M. Yates, Sarah M. Glaven et al.

ACS Applied Bio Materials • 2019

Bacterial microcompartment (BMC) shells are modular, selectively permeable, nanoscale protein shells that self-assemble from hexagonal and pentagonal building blocks in vivo or in vitro. Natural and engineered BMC shells colocalize and concentrate catalysts and metabolites in their lumen, increasing reaction kinetics. Here, we describe the design and characterization of a shell protein (pseudohexameric/trimeric BMC-T1HO protein) engineered to coordinate a Cu ion in its pore. Several designs, each varying the position of an introduced coordinating histidine residue, were shown to maintain their trimeric oligomerization state upon Cu coordination via chemical denaturation experiments. We measured reversible redox activity from electrode-bound Cu-3His BMC-T1HO variants, with formal potential(s) that were dependent on the Cu coordination site within the discoidal shaped trimer (E°' = +208 to +265 mV vs SHE). These results represent important steps toward expanding the functionality (Cu coordination) and applicability (redox activity on an electrode surface) of engineered BMC reactor architectures.

Mary P. Chang

Oxford Medicine Online • 2016

Bacterial meningitis is a bacterial infection causing inflammation of the meninges, the lining around the brain and spinal cord. It is important for emergency physicians to recognize potential bacterial meningitis early. They are usually the providers that the patient will present to first. If the patient is critically ill and suspicion for meningitis is high, immediately give steroids followed by antibiotics and then pursue diagnostic workup. Lumbar puncture will aid in definitive diagnosis. If this procedure will be delayed and suspicion for bacterial meningitis is high, give dexamethasone followed by antibiotics, even in a currently stable patient. Meningitis is a treatable condition, and early intervention will have a great impact on reducing morbidity and mortality.

, Ha Thanh Dong

• 2015

Columnaris disease, a bacterial infection caused by Flavobacterium columnare, has been reported in various freshwater fish species worldwide. Disease outbreaks usually result in mass mortality of cultured fish and severe financial losses for aquaculture producers. In aquaculture system, where the fish naturally exposed to various potential pathogens, the reality of dead-loss due to dual or multiple infections is highly predictable and probably outweighs single infection. This study aims to investigate concurrent bacterial infections and pathogen characterization from columnaris diseased fish with emphasis on tilapia and striped catfish. From two outbreaks in Nile tilapia farms in Thailand where fish exhibiting external clinical signs of columnaris disease, each naturally diseased fish was found to be concurrently infected by 2 to 4 out of the 5 identified pathogens including F. columnare, Aeromonas veronii, Streptococcus agalactiae, Plesiomonas shigeloides and Vibrio cholera. Upon experimental challenge tests, fish exposed to A. veronii or F. columnare mimicked major internal and external clinical signs of naturally infected fish, respectively. This suggested that A. veronii and F. columnare are two main pathogens co-responsible for the dead-loss of the outbreak cases reported in the present study, whereas remaining pathogens might serve as opportunistic agents in the disease outbreaks. Similarly, natural co-infections of F. columnare and Edwardsiella ictaluri were first reported in the striped catfish exhibiting external clinical signs of columnaris disease. Co-infection challenge by both intraperitoneal and intramuscular routes successfully mimicked typical signs and histopathological manifestations of natural co-infections thus fulfilling Koch’s postulates. Genetic diversity of F. columnare revealed that isolates originated from tilapia and striped catfish were phylogenetically different based on 16S rRNA. It was also found that the majority of F. columnare isolates from Thailand belongs to Genomovar II and formed rhizoid morphotype on AOA medium. The virulence of two morphotypes (rhizoid and non-rhizoid colonies) of F. columnare from tilapia collection was determined in vivo. The typical rhizoid isolate (CUVET1214) was a highly virulent isolate whereas the non-rhizoid isolate (CUVET1201) was avirulent to red tilapia fry. Adherence and persistence of both F. columnare morphotypes to tilapia fry were determined by whole fish bacterial loads. The results suggested that an inability of the non-rhizoid morphotype to persist in tilapia fry may explain lack of virulence. Additionally, diversity of non-F. columnare bacteria associated with columnaris diseased fish was characterized and proven to be merely opportunistic bacteria in this study.

Peter Atkins, Julio de Paula, James Keeler

Atkins’ Physical Chemistry • 2022

This chapter discusses electrode potentials. Each electrode can be considered to make a characteristic contribution to the overall cell potential. The standard potential of a couple is the potential of a cell in which the couple forms the right-hand electrode and the left-hand electrode is a standard hydrogen electrode, all species being present at unit activity. The electrochemical series lists the metallic elements in the order of their reducing power as measured by their standard potentials in aqueous solution: low reduces high. The chapter then explains how the difference of the cell potential from its standard value is used to measure the activity coefficient of ions in solution. Meanwhile, standard potentials are used to calculate the standard cell potential and then to calculate the equilibrium constant of the cell reaction.

A. C. Fisher

Electrode Dynamics • 1996

This chapter deals with the molecular identity of the species, particularly intermediates, that must be indirectly inferred. It discusses the employment of electrochemical studies in combination with spectroscopic measurements in order to provide more direct characterization. It also explains the additional information obtained from spectroelectrochemical measurements that open the door to the investigation of a wide range of complex surface and homogeneous processes occurring in electrochemical systems. The chapter highlights the structure characterization of the electrode surface, the identification of homogeneous phase molecules, and the study of species absorbed at the electrode/electrolyte interface. It cites the ideal characterization of electrode surfaces that requires information on atomic resolution.

Matthias Wessling

• 2020

Scale-up of flow-electrode capacitive deionization is hindered due to the reliance on thick brittle graphite current collectors. Inspired by developments of electrochemical technologies we present the use of flexible membrane electrode assemblies (MEA) to solve these limitations. We tested different carbon-fiber fabrics as current collectorsand laminated them successfully with ion-exchange membranes. The use of thinner ion-exchange membranes is now possible due to the reinforcement with the carbon fiber fabric.Desalination experiments reveal that a MEA setup can achieve salt transfer rates equal to standard setups. Hence, we deduce that charge percolation also acts outside the electric field. In a single point of contact, ionic and electric charges are exchanged at the carbon surface of the MEA. The use of thinner membranes leads to a reduced potential drop. Together with a more homogeneous electric field across the feed water section, this can compensate for the reduction of contact surface between flow electrode and current collector.

Gerasymchuk, Y., Adamenko, O., Lavrishchev, A. et al.

Mehanization and electrification of agricultural • 2019

Purpose. Get dependence to determine the mass of the chemical adsorbent which is contained on the rotating precipitating electrode of the electrotechnical means, taking into account the kinetics of the process of air purification of livestock buildings from harmful gases and bacterial contamination with the complex use of electrophysical and chemical methods of decontamination and air purification. Methods. Analysis of the influence of chemical adsorbent and crown discharge field on the efficiency of air purification of livestock buildings from harmful gases and bacterial contamination. Experimental researches for determination of basic parameters of a precipitating electrode of an electrotechnical means. Results. Scheme of the electrotechnical means with the complex using of electrophysical and chemical methods of purification and disinfection of recirculation air of ventilation emissions from ammonia, carbon dioxide, hydrogen sulfide and bacterial contamination. Polynomial dependence for determining the mass of a chemical adsorbent which is contained on a rotating depositing electrode. Conclusions. Complex using of the electrotechnical means for air purification from harmful gases and bacterial contamination of the recirculation air flow and the utilization heat of ventilation emissions with the implementation anti-icing protection heat exchange surface of the recuperative heat utilizers allows to reduce the level of air exchange and significantly reduce energy costs to provide regulatory airspace of livestock buildings in the cold season. On the disks of precipitating electrodes of an electrotechnical mean for cleaning and disinfection of recirculation air of ventilation emissions, it is necessary to fix a polymer mesh with an area of cellules of 16 mm2, and the frequency rotation of the discs to support within the range from 0.25 s-1 to 1 s-1. Keywords: microclimate, heat utilizer, recuperate, air purification, corona discharge, precipitating electrode.

Jiaqi Lin, Dongyang Wang, Hailing Xue et al.

Research Square • 2024

Abstract Non-invasive brain-computer interfaces (NI-BCIs) have garnered significant attention due to their safety and wide range of applications. However, developing non-invasive electroencephalogram (EEG) electrodes that are highly sensitive, comfortable to wear, and reusable has been challenging due to the limitations of conventional electrodes. Here, we introduce a simple method for fabricating semi-dry hydrogel EEG sensors with antibacterial properties, enabling long-term, repeatable acquisition of EEG. By utilizing N-acryloyl glycinamide and hydroxypropyltrimethyl ammonium chloride chitosan, we have prepared electrodes that not only possess good mechanical properties (compression modulus 65 kPa) and anti-fatigue properties but also exhibit superior antibacterial properties. These electrodes effectively inhibit the growth of both Gram-negative ( E. coli ) and Gram-positive ( S. epidermidis ) bacteria. Furthermore, the hydrogel maintains stable water retention properties, resulting in an average contact impedance of less than 400 Ω measured over 12 hours, and an ionic conductivity of 0.39 mS/cm. Cytotoxicity and skin irritation tests have confirmed the high biocompatibility of the hydrogel electrodes. In N170 event-related potential (ERP) tests conducted on human volunteers, we successfully captured the expected ERP signal waveform, comparable to that of traditional wet electrodes. Moreover, contact impedance on the scalps remained below 100 kΩ for 12 hours, while wet electrodes became unable to detect signals after 7–8 hours due to dehydration. In summary, our hydrogel electrodes are capable of detecting ERPs over extended periods in an easy-to-use manner with antibacterial properties. This reduces the risk of bacterial infections associated with prolonged reuse and expands the potential of NI-BCIs in daily life.

O H Tuovinen, D J Nicholas

Applied and Environmental Microbiology • 1977

A commercially available ion-selective electrode for nitrate was used to continuously monitor tetrathionate oxidation by Thiobacillus dentrificans. The electrode was much more sensitive to tetrathionate than to nitrate. The same electrode could also be used for the determination of trithionate.

Yunlong Liu, Panpan Liu, Mengjuan Li et al.

Research Square • 2025

Abstract A bacterial molecularly imprinted bipolar electrode (BPE) sensor combined with Au@metal-organic frame (Au@MOF) was developed for the E. coli O157:H7 detection. Firstly, dopamine (DA) was mixed with E. coli O157:H7 through an electropolymerization process to form polymer film on the BPE cathode. After bacteria removal, the bacterial molecularly imprinted polydopamine (PDA) film remained on the cathode, exhibiting high specificity for bacterial recognition and binding. Secondly, the E. coli O157:H7 aptamer was modified to the Au@MOF surface by Au-SH covalent bonds. Then, E. coli O157:H7 was present at the cathode, through the specific binding of aptamer to E. coli O157:H7, Au@MOF was assembled to the electrode surface. Finally, 3,3′,5,5′-tetramethylbenzidine/H2O2 (TMB/H2O2) solution was added to the cathode. The Au@MOF exhibited peroxidase-like activity and could catalyze the reduction reaction of TMB/H2O2 system. Due to the electrical neutrality principle of the BPE, the oxidation reaction of [Ru(bpy)3]2+/tripropylamine ([Ru(bpy)3]2+/TPA) system on the anode, generating a distinct Electrochemiluminescence (ECL) signal. The sensor detected E. coli O157:H7 within a concentration range of 1 to 106 CFU mL-1, with a detection limit of 1 CFU mL-1, demonstrating high selectivity and sensitivity. This BPE platform, integrating molecular imprinting and Au@MOF-assisted oxygen reduction, shows significant potential for bacteria detection in various applications.

Masaya Nohara, Yuhki Yui, Shuhei Sakamoto et al.

ECS Meeting Abstracts • 2016

Introduction Lithium air secondary batteries exhibit higher theoretical energy density than lithium ion batteries and are expected as next-generation secondary batteries. However, there remain technical challenges related to their poor cycle properties. Since the first report by K. M. Abraham et al. [1], various oxygen reduction/evolution catalyst [1-3] and electrolyte [1, 4] materials have been intensively investigated for air batteries to improve their electrochemical properties, such as their cyclability. However, there have only been a few studies on support materials for air electrodes, such as nanoporous gold [5]. We consider that one of the reasons for the poor cyclability is a decrease in the electrical contact of the air electrode during Li 2 O 2 deposition (discharge) and oxygen generation (charge), which results from large the volume change. The purpose of our work is to improve the cyclability by using a new air electrode structure and material. As an elastic support material for air electrodes, we focus on carbon fabricated from bacterial cellulose (BC), which has a continuous interconnected network of carbon. Such an elastic carbon support would prevent the large volume change of the air electrodes and improve the cycle performance. Here we report the preparation conditions for BC-derived carbon supports materials and the performance of lithium air secondary batteries incorporating them. Experimental A BC sheet (Fujicco Co., Ltd.) was frozen at -40 °C and then freeze-dried [6]. The freeze-dried BC sheet was carbonized in N 2 atmosphere at 600, 900, and 1200 °C to obtain BC-derived carbon. It was cut into a circle (diameter: 5 mm) to obtain the binder-free air electrode. The lithium air secondary battery consisted of the air electrode, a lithium metal sheet, and 1.0 mol/l lithium bis(trifluoromethanesulfonyl)amide (LiTFSA)/tetraethylen glycol dimethyl ether (TEGDME) as the positive electrode, negative electrode, and electrolyte solution, respectively. The battery was assembled with an ECC-Air Cell (EL-CELL GmbH). Electrochemical measurements were carried out under a galvanostatic condition of 0.1 mA/cm 2 in an O 2 atmosphere. The discharge and charge capacities were normalized by the weight of the BC-derived carbon (the air electrode). Results and discussion Figure 1 shows an SEM image of the BC-derived carbon prepared at 1200 °C. The continuous interconnected network of the carbon fibers with diameter of less than 10 nm can be seen in this image. These carbon fibers build a 3-D disordered macroporous framework. The BC-derived carbon prepared at 600 and 900 °C was confirmed to have morphologies similar to that at 1200 °C. Moreover, in a preliminary compression test, the BC-derived carbon showed a highly elastic compressibility and almost completely recovered its original volume after the compression was released. Figure 2 shows the first discharge/charge curves of the air batteries incorporating the BC-derived carbon prepared at 600, 900, and 1200 °C. The air batteries with the carbon prepared at 900 °C showed the largest discharge capacities of 8800 mAh/g and the average discharge voltage of 2.68 V. This is because it has the largest number of active sites among the carbons tested. The batteries incorporating BC-derived carbon prepared at 900 and 1200 °C showed almost the same charge capacities of about 8000 mAh/g. These charge properties have a tendency similar to the discharge properties even though the air electrodes have no catalysts. These results indicate that the BC-derived carbon can be used as support material for binder-free air electrodes. Figure 3 shows the correlation between the discharge capacities, D/G ratio, and carbonization temperature. In the Raman spectra of the carbon as shown in the inset, the peaks of D- and G-bands are derived from the edge-plane and basal-plane in the crystal structure of carbon, respectively. The D/G ratio was obtained from the results of wave analyses with the spectra in the inset. It correlates roughly with the discharge capacities as shown in Fig. 3. In particular, the battery incorporating the carbon prepared at 900 °C, which has the largest discharge capacity, has the highest D/G ratio. This indicates the importance of the number of carbon edge planes in relation to the discharge property, because the D/G ratio corresponds to a ratio of number of carbon edge planes to that of basal planes. These results indicate that the carbon edge planes would play an important role as active sites in the reaction mechanism with the air electrode. References [1] K. M. Abraham et al., J. Electrochem. Soc., 143 (1996) 1. [2] T. Ogasawara et al., J. Am. Chem. Soc., 128 (2006) 1390. [3] A. K. Thapa et al., Electrochem. Solid-State Lett., 13 (2010) A165. [4] N.-S. Choi et al., J. Power Sources, 225 (2013) 95. [5] Z. Peng et al., Science, 375 (2012) 563. [6] H. W. Liang et al., NPG Asia Materials, 4 (2012) e19. Figure 1

T. Dudding, C. Vaizey

Colorectal Disease • 2010

Abstract Objective In patients undergoing sacral nerve stimulation (SNS), a temporary percutaneous stimulation wire is often used to assess the clinical response to therapy prior to chronic stimulation. The aim of this study was to evaluate the incidence of bacterial colonization of screening wires and risk of clinical infection in patients undergoing prolonged temporary SNS screening. Method Data were collected prospectively on a consecutive series of patients undergoing temporary SNS for bowel dysfunction. Procedures were performed using a standardized percutaneous technique with a single shot of either co‐amoxyclav 1.2 g or cefuroxime 1.5 g given intravenously on induction. Adherent polyurethane dressings were applied to secure the wire. At the end of the screening period the wire and dressings were removed, the skin entry site was cleaned using an alcohol wipe and the wire removed via an aseptic technique. The distal tip of the wire was then cut and sent for culture. Results Thirteen wires were removed at a median of 21 (range 16–29) days following insertion. There were no signs of local or systemic infection. Seven of the thirteen wires (54%) were found to have deep bacterial colonization. The commonest organisms isolated were staphylococcus species. There was no correlation between the length of time the lead had been implanted and the incidence of bacterial colonization. Conclusion Bacterial colonization of the temporary stimulation wire is common but appears to be associated with a low risk of clinical infection. A single peri‐operative dose of antibiotics does not appear to prevent colonization.

Shumin Liu, Jia Chen, Jinpeng Sun

International Journal of Biology and Life Sciences • 2023

Using the natural nanomesh structure of bacterial cellulose (BC), the good conductivity of multi-walled carbon nanotubes (MWCNTs) and the good electrocatalytic activity of nano platinum (PtNPs), a three-way porous conductive hydrogel of PtNPs and BC was designed. The infiltrating and doping of MWCNTs on BC thin films was realized by ultrasonic assisted electrophoretic deposition process, which ensured the dual characteristics of ionic and electronic conduction of electrode films. The adsorption capacity of BC for chloroplatinic acid and the strong reductivity of sodium borohydride were also used to realize the high-load PtNPs recombination on MWCNTs/BC porous layered conductive hydrogel electrode films. By testing the electrochemical performance of PtNPs/MWCNTs/BC conductive hydrogel electrode film and characterization of microstructure, the electrode film not only has high electroactive area, low surface charge transfer resistance and good diffusion permeability and other electrochemical characteristics, but also shows high catalytic activity for glucose in PBS solution. The most important finding is that the electrode film can selectively catalyze glucose in oxygen-rich PBS solution. The porous layered structure of PtNPs/MWCNTs/BC electrode membrane and the high load dispersion of PtNPs are the reasons for the selective catalytic ability of PtNPs/MWCNTs/BC conductive hydrogel electrode membrane, which can be used for the implanted surface glucose fuel cell.

Hans‐Peter Schär, Oreste Ghisalba

Biotechnology and Bioengineering • 1985

Abstract A biosensor consisting of physically entrapped monomethyl sulfate (methyl sulfate) degrading bacterium, Hyphomicrobium MS 219 , and a combined glass electrode has been developed for the determination of methyl sulfate. The response of the bacterial electrode is linear between 2.5 × 10 −2 M and 6.3 × 10 −1 M methyl sulfate with an effective response to concentrations as low as 10 −3 M and as high as 1 M methyl sulfate. The probe has an average slope of 8 mV per concentration decade over the linear range. Response times vary from 5 min in the linear range to 30 min at the detection limit. The sensor has a lifetime of at least 1 week and shows high selectivity to methyl sulfate in the absence of other growth substrates.

H.-E. Jacob

Pathobiology • 1970

In bacterial cultures and buffer solutions the redoxpotential values depend on the condition of the electrode surface. This is shown by comparison of various pretreatments of the electrode. In order to obtain a fast response of the redoxpotential as a function of changes in oxygen pressure and to measure redox’ potential-values accurately, mechanical cleaning and polishing of the platinum electrode is recommended.

A. L. Yarin

Applied Physics Letters • 2007

In this letter, the origin of a force resulting in steady-state propagation of a spherical electrode in a leaky dielectric is explained and the force is calculated. The phenomenon of self-propagation begins from a perturbation in any direction resulting in the electrode motion in that direction. After that, the process sustains itself and a macroscopic electrode moves in the direction of the initial perturbation with a constant velocity U proportional to the potential difference ΔV applied to the system. Microscopic electrodes and bacterial flagellar motors should move with a velocity U∼(ΔV)2. The predicted velocities agree fairly well with the experimental data.

Chinnatad Sinprasertchok, Nuwong Chollacoop, Sumittra Charojrochkul et al.

Key Engineering Materials • 2017

Microbial extracellular electron transfer is a significant process in a microbial fuel cell (MFC). Owing to many potential losses in the electron transfer from microorganism to an electrode, a promotion of microbial attachment to electrode should be a productive solution to this difficulty of MFC. We also introduced here a prior colonization of microbes on electrode instead of a conventional immobilization which entirely occurred in a MFC reactor to expedite an attachment of microorganisms on the electrode surface. Coconut shell-based granular activated carbons (CGACs) used as one of the electrodes in the upflow bio-filter circuit microbial fuel cell were immersed in Lysogeny broth (LB) at pH 7 before an inoculation of anaerobic consortium from a wastewater treatment plant was performed. The immobilization was proceeded in an Erlenmeyer flask at 30°C with a shaking speed of 100 rpm throughout an experiment. CGACs taken from a collection of flasks were examined a surface with scanning electron microscopy (SEM). On the 3 rd day of immobilization, SEM images showed that a colonization was seen obviously in large pores on CGAC surface. There were quite plentiful possessions on a rough surface while smooth surface not supporting well at the beginning got worse in attraction of bacteria on day 9 of immobilization. An addition of fresh LB into immobilization solution was conducted to improve the microbial attachment to smooth surface of CGAC. At 9 days after inoculation, the consequence of fresh medium filling did obviously raise the number of bacteria on the plain surface as opposed to earlier experiment.

Leonard M. Tender

MRS Bulletin • 2011

Abstract

Michael Chen, Neha Mehta, Benjamin D. Kocar

ChemRxiv • 2020

Semi-conducting Fe oxide minerals, such as hematite, are well known to influence the fate of contaminants and nutrients in many environmental settings and influence microbial growth under suboxic to anoxic conditions through a myriad of different processes. Recent studies of Fe oxide reduction by Fe(II) have demonstrated that reduction of Fe at one surface can result in the release of Fe(II) different one. Termed Fe(II) catalyzed recrystallization, this phenomena is attributed to conduction of additional electrons through the mineral structure from the point of contact to another which occurs because of the minerals’ semi-conductivity. While it is well understood that Fe(II) plays a central role in redox cycling of elements, the environmental implications of Fe(II) catalyzed recrystallization need to be further explored. Here, we provide evidence that the Fe mineral conductivity underpinning Fe(II) catalyzed recrystallization can couple the reduction of Cr, a priority metal contaminant, with an electron source that is cannot directly affect Cr. This is shown for both an abiotic electron source, a potentiostat, as well as the metal reducing bacteria Shewanella Putrefaciens. The implications of this work show that semiconductive minerals may be links in subsurface electrical networks that physically distribute redox chemistry and suggests novel methods for remediating Cr contamination in groundwater.

Stanley E. Manahan

Applied Microbiology • 1969

A nitrate ion-selective electrode has been used to follow the kinetics of the reduction of nitrate by a bacillus isolated from the rumen of a sheep. The electrode system and the microbial culture were found to be quite compatible, although the formation of nitrite limits the utility and precision of the measurement. The formation of nitrite was followed simultaneously by a colorimetric method. Nitrate was converted quantitatively to nitrite. The rate of the reaction was found to increase to a plateau value, then drop abruptly when the nitrate was exhausted.

Karol Lang

Bio-Algorithms and Med-Systems • 2024

<b>Objective:</b> The in-vivo therapy guidance by imaging and dosimetry of proton irradiations, generically known as proton range verification, are some of the most underinvested aspects of radiation oncology. They trail behind other advances in radiation therapy due to the scarcity of sensitive instruments compounded by the lack of treatment protocols for precision monitoring of effects of beam radiation. This is despite that such measurements may dramatically enhance the treatment accuracy and lower the postradiation toxicity, thus improving the entire outcome of cancer therapy. <br><b>Methods:</b> In this contribution, we focus on the motivation of designing and building of an in-beam time-of-flight (ToF) positron-emission-tomography (PET) scanner with the depth-of-interaction (DoI) capability for high sensitivity and improved fidelity of imaging. A scanner could be augmented with a tungsten collimator that would enable prompt-gamma imaging (PGI) via single-photon emission computed tomography (SPECT) technique. <br><b>Results:</b> We present selected results of our pre-clinical experiments with a FLASH proton beam and discuss other related ideas towards improving and expanding the use of PET/PGI/SPECT detectors for proton therapy. A scanner provides an access to data during the spill and past the spill permitting to capture the beam interaction and kinetic monitoring of its effect thus allowing a thorough assessment of each irradiation.<br><b>Conclusions:</b> A novel scanner for multiple modalities can substantially improve the treatment precision of proton therapy leading to less toxic outcome of irradiations. Using it in the FLASH modality would additionally expand the patient reach of proton therapy.

Sergey Kukushkin, Dariko Balakhanov, Yury Zhurov

BIO Web of Conferences • 2024

These days the economic system of any scale faces a challenge not only to best meet the needs of consumers, but also to ensure their comfortable living conditions (especially agricultural), that is, preserve the environment and use natural resources wisely. Power generation enterprises make a significant contribution to the violation of the environmental situation. This is partly due to the alienation of territories that could be used for other human activities, as well as significant emissions into the atmosphere. A power generation enterprise, compared with organizations of other types of activity, is characterized by the method of generating electricity which implies not the impact on the material and raw materials and the production of economic benefits, but the conversion of natural energy into electrical energy. These models are of a general abstract nature and are more applicable to organizations producing tangible economic benefits, rather than the generation of electrical energy, which is the key economic benefit, though, conventionally tangible one. Existing microeconomic models do not show specifics of their functioning – the scale of the enterprise and the conditions for profit maximization. The economic models of a power generation enterprise, the specifics of its functioning and profit-making are presented in the article.

Chris Vermillion

Volume 3: Nonlinear Estimation and Control; Optimization and Optimal Control; Piezoelectric Actuation and Nanoscale Control; Robotics and Manipulators; Sensing; System Identification (Estimation for Automotive Applications, Modeling, Therapeutic Control in Bio-Systems); Variable Structure/Sliding-Mode Control; Vehicles and Human Robotics; Vehicle Dynamics and Control; Vehicle Path Planning and Collision Avoidance; Vibrational and Mechanical Systems; Wind Energy Systems and Control • 2013

This paper presents a control strategy that combines altitude and crosswind motion control for tethered wind energy systems with airborne turbines and generators. The proposed algorithm adjusts altitude and induces an appropriate level of crosswind motion to present the system with an apparent wind speed that most closely meets, but does not exceed, the rated wind speed of the on-board turbine(s), thereby tracking the turbine’s optimal power point. The adjustment of both altitude and motion control, along with the reduction in crosswind motion and altitude when the rated wind speed is exceeded, differentiates the proposed control architecture from other strategies proposed in the literature. Initial control laws and simulation results are presented for the Altaeros lighter-than-air wind energy system.

M. H. Ansari, Karthik Yerrapragada, M. Amin Karami

Volume 2: Modeling, Simulation and Control; Bio-Inspired Smart Materials and Systems; Energy Harvesting • 2016

When there is a two to one internal resonance ratio between the natural frequencies of the pitch motion and the roll motion of a ship, a nonlinear energy transfer occurs between the modes. If the ship is excited near the pitch natural frequency and at a large enough excitation amplitude, the pitch mode transfers energy to the roll mode. We use this interesting phenomenon to develop a wave power device for off-shore purposes. In this paper, we experimentally show that we can use a horizontal pendulum and use the quadratic nonlinear coupling between the pitch and the roll mode to get full rotation of the pendulum inside the ship. A rotating pendulum will generate orders of magnitude more power than a locally oscillating one when connected to a DC generator. This article measures the angle of the pendulum at the pitch frequency excitation of the ship to experimentally confirm the expected theoretical results on this phenomenon.

Mario L. Ferrari, Marco De Campo, Loredana Magistri

Volume 3: Coal, Biomass, and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration; Organic Rankine Cycle Power Systems • 2018

This paper presents a steady-state model of an innovative turbocharged solid oxide fuel cell system fed by biofuel. The aim of this plant layout is the development of a reduced-cost solution, which involves the pressurization carried out with a mass production machine such as a turbocharger (instead of a microturbine). The turbocharger pressurizes the solid oxide fuel cell to increase the performance. Following the experimental results to choose the suitable machine and for validating the turbocharger model, this tool was implemented to model the whole plant. It was used to calculate the operational conditions and to define the coupling aspects between the turbocharger, the recuperator and the solid oxide fuel cell system (comprising a fuel cell stack, an air preheater, a reformer, an off-gas burner and an anodic ejector). The model permitted the component characterization and supported the design of an emulator test rig based on the coupling of a turbocharger and a pressure vessel. This facility was designed to conduct the experimental tests at system level on the matching between the machine and the fuel cell, especially for the dynamic and the control system aspects. To emulate the fuel cell, the rig was based on a specially designed pressure vessel equipped with a burner and inert ceramic materials. Moreover, the facility was designed to produce the turbine inlet conditions in terms of mass flow, temperature, pressure and gas composition (similitude conditions can be evaluated).

Mykola Vasylenko, Olha Baranova

Electronics and Control Systems • 2024

Alternative energy sources allows to replace traditional fossil fuels and firewood. However the most widely used wind and solar power plants can not provide constant power generation due to multiple factors that makes necessary to develop new types of power sources and to to improve efficiency of already existing ones. One of such energy sources are bio gas-fueled power plants which allow to combine the power generation and organic waste disposal functions. Efficiency and quality of bio gas production in such facilities can be significantly increased by using different catalysts such as biochar. A brief analysis of biochar production usage perspectives was held which showed that it can be used in different applications and can significantly increase efficiency of different technological processes. The influence of biochar on the biogas production processes was studied. The structure of bio gas-fueled heat and power plant with local bio gas generation was proposed.

Gustave Ronteix, Andrey Aristov, Valentin Bonnet et al.

bioRxiv (Cold Spring Harbor Laboratory) • 2022

Microscopy techniques and image segmentation algorithms have improved dramatically this decade, leading to an ever increasing amount of biological images and a greater reliance on imaging to investigate biological questions. This has created a need for methods to extract the relevant information on the behaviors of cells and their interactions, while reducing the amount of computing power required to organize this information. This task can be performed by using a network representation in which the cells and their properties are encoded in the nodes, while the neighborhood interactions are encoded by the links. Here, we introduce Griottes, an open-source tool to build the “network twin” of 2D and 3D tissues from segmented microscopy images. We show how the library can provide a wide range of biologically relevant metrics on individual cells and their neighborhoods, with the objective of providing multi-scale biological insights. The library’s capacities are demonstrated on different image and data types. This library is provided as an open-source tool that can be integrated into common image analysis workflows to increase their capacities.

J. Lv, Xin Zhang, Nana Li et al.

RSC Advances • 2015

Metal nanoparticles (MNPs) can be used as a kind of new photodynamic therapy (PDT) agent because singlet oxygen (1O2) can be generated through directly sensitizing MNPs. Gold nanorods, gold nanoshells and gold nanoechinus were confirmed to be efficient PDT agents in vivo. However, the major excitation spectra of 1O2 from all of them are not in the optical biological window (650–900 nm). Herein, gold bipyramids (GBPs) with tunable absorption wavelength were prepared and used to explore 1O2 generation capability. 1O2 can be generated when GBPs were excited by continuous-wave light within a wide range of wavelengths (660–975 nm). The highest 1O2 generation capabilities were obtained when they were excited at the wavelength of the absorption peak, which was quite different from those of other gold nanomaterials. It was also found that 1O2 can be generated efficiently by a laser of very low power density (200 mW cm−2). The capability of GBPs for PDT has been demonstrated through the destruction of cancer cells. The synergistic effect of PDT and photothermal therapy for the destruction of cancer cells was also demonstrated.

Hanwen Liu, Yi Chen, ZiHang Zeng et al.

2023 International Joint Conference on Neural Networks (IJCNN) • 2023

Spiking Neural Networks (SNNs), known as the third generation of the neural network, are famous for their biological plausibility and brain-like characteristics. Recent efforts further demonstrate the potential of SNNs in high-speed inference by designing accelerators with the parallelism of temporal or spatial dimensions. However, with the limitation of hardware resources, the accelerator designs must utilize off-chip memory to store many intermediate data, which leads to both high power consumption and long latency. In this paper, we focus on the data flow between layers to improve arithmetic efficiency. Based on the spike discrete property, we design a convolution-pooling(CONVP) unit that fuses the processing of the convolutional layer and pooling layer to reduce latency and resource utilization. Furthermore, for the fully-connected layer, we apply intra-output parallelism and inter-output parallelism to accelerate network inference. We demonstrate the effectiveness of our proposed hardware architecture by implementing different SNN models with the different datasets on a Zynq XA7Z020 FPGA. The experiments show that our accelerator can achieve about x28 inference speed up with a competitive power compared with FPGA implementation on MNIST dataset and a x15 inference speed up with low power compared with ASIC design on DVSGesture dataset.

Jeechan Yoon, Bolim You, Yuna Kim et al.

ACS Applied Materials & Interfaces • 2023

While neuromorphic computing can define a new era for next-generation computing architecture, the introduction of an efficient synaptic transistor for neuromorphic edge computing still remains a challenge. Here, we envision an atomically thin 2D Te synaptic device capable of achieving a desirable neuromorphic edge computing design. The hydrothermally grown 2D Te nanosheet synaptic transistor apparently mimicked the biological synaptic nature, exhibiting 100 effective multilevel states, a low power consumption of ∼110 fJ, excellent linearity, and short-/long-term plasticity. Furthermore, the 2D Te synaptic device achieved reconfigurable MNIST recognition accuracy characteristics of 88.2%, even after harmful detergent environment infection. We believe that this work serves as a guide for developing futuristic neuromorphic edge computing.

Aldo Moscardini, S. Di Pietro, G. Signore et al.

Scientific Reports • 2020

Biological samples are mainly composed of elements with a low atomic number which show a relatively low electron scattering power. For Transmission Electron Microscopy analysis, biological samples are generally embedded in resins, which allow thin sectioning of the specimen. Embedding resins are also composed by light atoms, thus the contrast difference between the biological sample and the surrounding resin is minimal. Due to that reason in the last decades, several staining solutions and approaches, performed with heavy metal salts, have been developed with the purpose of enhancing both the intrinsic sample contrast and the differences between the sample and resin. The best staining was achieved with the uranyl acetate (UA) solution, which has been the election method for the study of morphology in biological samples. More recently several alternatives for UA have been proposed to get rid of its radiogenic issues, but to date none of these solutions has achieved efficiencies comparable to UA. In this work, we propose a different staining solution (X Solution or X SOL), characterized by lanthanide polyoxometalates (LnPOMs) as heavy atoms source, which could be used alternatively to UA in negative staining (NS), in en bloc staining, and post sectioning staining (PSS) of biological samples. Furthermore, we show an extensive chemical characterization of the LnPOM species present in the solution and the detailed work for its final formulation, which brought remarkable results, and even better performances than UA.

M. R. Edwards, J. Mikhailova

Scientific Reports • 2020

Ultrashort pulsed lasers provide uniquely detailed access to the ultrafast dynamics of physical, chemical, and biological systems, but only a handful of wavelengths are directly produced by solid-state lasers, necessitating efficient high-power frequency conversion. Relativistic plasma mirrors generate broadband power-law spectra, that may span the gap between petawatt-class infrared laser facilities and x-ray free-electron lasers; despite substantial theoretical work the ultimate efficiency of this relativistic high-order-harmonic generation remains unclear. We show that the coherent radiation emitted by plasma mirrors follows a power-law distribution of energy over frequency with an exponent that, even in the ultrarelativistic limit, strongly depends on the ratio of laser intensity to plasma density and exceeds the frequently quoted value of −8/3 over a wide range of parameters. The coherent synchrotron emission model, when adequately corrected for the finite width of emitting electron bunches, is not just valid for p-polarized light and thin foil targets, but generally describes relativistic harmonic generation, including at normal incidence and with finite-gradient plasmas. Our numerical results support the ω−4/3 scaling of the synchrotron emission model as a limiting efficiency of the process under most conditions. The highest frequencies that can be generated with this scaling are usually restricted by the width of the emitting electron bunch rather than the Lorentz factor of the fastest electrons. The theoretical scaling relations developed here suggest, for example, that with a 20-PW 800-nm driving laser, 1 TW/harmonic can be produced for 1-keV photons.

Ashutosh K. Giri, Sabha Raj Arya, Rakesh Maurya et al.

IET Renewable Power Generation • 2020

In this study, a control algorithm based on non‐linear adaptive second‐order Volterra filter (NLVF) is utilised to operate the voltage‐source converter (VSC). The main role of VSC is to supply compensating current to improve the power quality in wind‐based off‐grid distributed power generation system. This off‐grid system consists of three‐phase induction generator, VSC and non‐linear loads. The proposed control algorithm is adaptive as well as non‐linear in nature. The characteristic of Volterra series is exploited to generate the reference source current for VSC operation. The NLVF estimates the active and reactive weights of fundamental load current for reference current generation. It mitigates the power quality problems created by disturbances in non‐linear load or wind oscillations on off‐grid system. The solution of power quality problems such as the presence of harmonics in supply current, load unbalance and reactive power compensation is obtained. Nevertheless, voltage and frequency control are also achieved. The VSC is used as a shunt compensator in the system. The entire off‐grid system is designed and validated through the laboratory prototype development. The objective of the system is achieved and the steady state and dynamic performance is found satisfactory.