Search

Elektrokemijski senzori su zbog svoje jednostavnosti izrade i upotrebe u kontinuiranom razvoju već više od stoljeća te su brojnim modifikacijama dosegli brojna poboljšanja, što se posebno odnosi na povećanje osjetljivosti i selektivnosti, proširenje linearnog dinamičkog područja te sniženje granice dokazivanja analita. Spomenuta poboljšanja posljedica su noviteta u samoj izvedbi i izgledu elektrokemijskih senzora, kao i sve češće uporabe različitih nanomaterijala kao modifikatora. Među najčešće upotrebljavanim modifikatorima su upravo nanočestice metalnih oksida koje se u senzorima pojavljuju samostalno ili u kombinaciji s drugim materijalima. Posebno se ističe kombinacija nanočestica metalnih oksida i grafena ili (reduciranog) grafenova oksida. Navedena dva materijala sinergijski djeluju s obzirom na to da su grafenski slojevi zaduženi za bolju električnu vodljivost, a nanočestice metalnih oksida za sprječavanje njihove agregacije. Također, česta je i kombinacija s višeslojnim ili jednoslojnim ugljikovim nanocjevčicama te nanočesticama metala. Postoje radovi u kojima su kombinirane različite vrste nanočestica metalnih oksida, što je posebno istaknuto kod kombinacije Al2O3 i ZnO. Osim aluminijeva i cinkova oksida, u ovom radu je prikazan pregled literature upotrebljavanih nanočestica željezovih i bakrovih oksida u procesu modifikacije elektrokemijskih senzora. Uz to, prikazani su podatci o analitu, metode određivanja, linearno dinamičko područje senzora te granica dokazivanja analita. Očit je širok spektar vrsta analita čije je određivanje moguće ovakvim vrstama senzora kao i širok spektar elektroanalitičkih metoda koje su prilikom toga primjenjivane. Ipak, među metodama su najzastupljenije voltametrijske, dok je potenciometrijska metoda primjenjivana u svega nekoliko referencija.

Elektrokemijski senzori imaju sposobnost pretvorbe elektrokemijske reakcije koja se odvija između analita i elektrode u analitički koristan signal. Potenciometrijski senzori, ionsko-selektivne elektrode, kao važan član obitelji elektrokemijskih senzora, u središtu su brojnih istraživanja već gotovo cijelo stoljeće. Njihov stalni razvoj te kombinacija s razvojem drugih znanstvenih i tehnoloških područja osigurali su im širok spektar primjene. Svojstva ionsko-selektivnih elektroda kao što su jednostavnost metode, niska cijena, mala veličina senzora, kratko vrijeme očitavanja signala i pouzdanost učinila su ih vrijednim konkurentima među brojnim sofisticiranijim metodama za određivanje koncentracije analita u širokom spektru različitih realnih uzoraka bez ili uz minimalnu obradu uzorka. S obzirom na široku distribuciju i visoku važnost željezovih(III) kationa u ljudskom organizmu ali i okolišu, postoji visoka potreba za razvojem analitičkih alata za njihovo brzo i efikasno određivanje. U ovom je radu predstavljen niz literaturnih izvora koji obrađuju razvoj potenciometrijskih senzora upotrijebljenih za određivanje željezovih(III) kationa s naglaskom na znanstvene radove objavljene u posljednjem desetljeću. Iz spomenutih literaturnih izvora uspoređeni su aktivni centri senzora, linearno dinamičko područje, granica detekcije te promjene potencijala u ovisnosti o koncentraciji analita. Također, utvrđeno je kako su Fe3+ kationi uspješno određeni u brojnim realnim uzorcima poput farmaceutskih pripravaka, bioloških uzoraka, različitim uzorcima vode (pitkoj, otpadnoj, mineralnoj…), prehrambenim proizvodima poput zelenog i crnog čaja i dr. Upravo zbog širokog linearnog područja, niske granice detekcije te širokog spektra realnih uzoraka u kojima ih je moguće primijeniti ionsko-selektivne elektrode perspektivni su kandidati za zamjenu nekih sofisticiranijih metoda za određivanje željezovih(III) kationa.

Aims: The aim of this study is to report the implant survival and factors associated with revision of total elbow arthroplasty (TEA) using data from the Dutch national registry. Methods: All TEAs recorded in the Dutch national registry between 2014 and 2020 were included. The Kaplan-Meier method was used for survival analysis, and a logistic regression model was used to assess the factors associated with revision. Results: A total of 514 TEAs were included, of which 35 were revised. The five-year implant survival was 91%. Male sex, a higher BMI, and previous surgery to the same elbow showed a statistically significant association with revision (p < 0.036). Of the 35 revised implants, ten (29%) underwent a second revision. Conclusion: This study reports a five-year implant survival of TEA of 91%. Patient factors associated with revision are defined and can be used to optimize informed consent and shared decision-making. There was a high rate of secondary revisions. Cite this article: Bone Jt Open 2023;4(2):110–119.

Background: The reported complication rate after total elbow arthroplasty is high, and objective outcomes are not always predictive of satisfaction. This study aims to investigate the effect of a short-term complication on patient satisfaction and patient-reported outcome measures. Methods: We retrospectively included 126 patients who received a primary total elbow arthroplasty at our hospital between 2008 and 2018 and compared outcomes between patients with a complication and patients without complications occurring within 1 year using t-tests or Mann-Whitney U tests. P-values were corrected using the Benjamini-Hochberg procedure. Results: In total, 26 patients developed a complication (21%). At the 1-year follow-up, there were no significant differences between the groups. At the 3-year follow-up, patients with a complication had a lower median satisfaction score (8 vs. 10; P = .0288) and Oxford Elbow Score (27 vs. 43; P = .0048). At the 5-year follow-up, there were no differences between the groups. However, the number of patients who completed the 5-year follow-up is low (42 patients). Discussion: Complications occurred in 21% of patients undergoing total elbow arthroplasty and lead to a decrease in satisfaction and Oxford Elbow Score after 3 years.

Purpose: Objective and reliable force measurement is necessary to monitor the rehabilitation after triceps brachii pathology, injuries, and posterior approach–based surgery. It is unclear at which amount of extension the triceps is best tested and if comparison to the uninjured sided is reliable. This study aims to identify the most reliable elbow position at which elbow extension force is measured using a dynamometer. Furthermore, it aims to compare the extension strength of the dominant arm with that of the nondominant arm. Methods: Isometric elbow extension force of the dominant and nondominant arms of healthy subjects was measured. The measurements were taken in three sequences per arm in 0, 30, 60, 90, and 120 degrees of flexion. A subgroup repeated the measurements to analyze test–retest reliability using intraclass correlation. Results: We included a total of 176 volunteers. The repeated measures analysis of variance for within-subject effect showed the lowest variation coefficient at 30 degrees of flexion. Extension forces showed a mean difference of 3.2–6.9 N in advantage of the dominant arm, resulting in ratios from 1.05 to 1.09. Learning curve analysis showed that during the first session in dominant and nondominant arms, less forces were exerted. Conclusion: The most reliable isometric triceps brachii muscle strength measurement was at 30 degrees of flexion of the elbow. Considering the learning curve, a first tryout session for both arms is indicated. Then, a second measurement suffices as no further learning curve is observed.

As it was shown recently that nanostructures can exist in water-ethanol-citronellol tinctures, a deeper investigation of these media was performed using conductivity, UV-Vis and FT-IR spectroscopy techniques. Different regimes of conductivity, depending on the water content, an increase of the polarity of the polar pseudo-phase with increasing water content, and even the presence of free water molecules at higher water content are observed, just as in classical surfactant-based microemulsions. The percolation model, generally used to fit conductivity data in surfactant based microemulsion having a weak interfacial film, can be used to fit our conductivity data below a critical water content with a critical exponent typical of dynamic percolation. In presence of higher water contents, superior to , our conductivity data cannot be fitted neither with a static nor a dynamic percolation model. As in surfactant-based microemulsions, an increase of polarity of the microenvironment with increasing water content can be postulated using respectively the UV-Vis wavelength absorption band (λmax) of methyl orange and performing FT-IR spectra.

Abstract Background To assess the results after elbow arthroplasty it is essential to gather patient-reported outcome measures (PROMs). However, the acquisition of PROMs poses a challenge because of potential low literacy, lengthiness and diversity of questionnaires, and questionnaire fatigue. Instead of a questionnaire, patient-reported outcomes can be collected using a single assessment numeric evaluation (SANE), the subjective elbow value (SEV). The aim of this pilot study is to assess the correlation between the SEV and conventionally used patient reported outcome measures (PROMs) after elbow arthroplasty. Materials and methods The SEV was added to our follow-up system in 2021, consisting of a scale from 0 to 10 in which the patients are asked to rate the overall functionality of their elbow, 0 corresponds to very poor functionality and 10 to a perfectly functional or healthy elbow. All patients who underwent elbow arthroplasty (total or radial head) and responded to the SEV question were retrospectively identified and included. The correlation between the SEV at the final follow-up and the Oxford Elbow Score (OES), and between the SEV and the Quick Disbailities of the Arm, Shoulder, and Hand (quickDASH) score was assessed using Pearson’s r. Results In total, 82 patients responded to the SEV question and were included in the study, with a median follow-up of 5 years [interquartile range (IQR) 3–7]. Of these patients, 17 (21%) underwent radial head arthroplasty and 65 (79%) total elbow arthroplasty. The Pearson’s r for the correlation between SEV and OES was 0.502 (p

We describe a new method using flow-injection analysis with spectro-photometric detection, suitable for the determination of N-acetyl-L-cysteine (NAC). The proposed method is appropriate for the determination of NAC in reaction with Pd2+ ions in the concentration range from 1.0 × 10−5 mol L−1 to 6.0 × 10−5 mol L−1. The detection limit NAC was 5.84 × 10−6 mol L−1 and the recorded relative standard deviation of the method is in the range from 1.67 to 4.11%. NAC and Pd2+ form complexes of Pd2+:NAC molar ratios of 1:1 and 1:2, depending on the ratio of their analytical concentrations. The cumulative conditional stability constant for the Pd(NAC)22+ complex is β12' = 2.69 × 109 L2 mol−2. The proposed method was compared with the classic spectrophotometric determination of NAC, using the same reagent, PdCl2, and had shown certain advantages: a) shorter analysis time; b) the use of smaller volumes of sample and reagents, which make the proposed method cheaper and faster for NAC determination in real samples without sample pretreatment.

Samples of white and red wines produced in two different wine-growing regions, coastal (Dalmatia) and continental (Hrvatsko zagorje) of Croatia, were analysed for biogenic amines content. Biogenic amines content was determined, and its concentration levels were associated with the geographical origin of the wine. Due to its high sensitivity, HPLC method with ultraviolet detector was used, including the derivatisation step with dansyl chloride. The method was applied to detect and quantify 11 biogenic amines in 48 red and white wines. It was found that both Dalmatian red and white wines are characterised by tryptamine (0.23–1.22 mg L−1), putrescine (0.41–7.5 mg L−1) and ethanolamine (2.87–24.32 mg L−1). White wines from the Hrvatsko zagorje region are characterised by content of isopentylamine (0.31–1.47 mg L−1), putrescine (0.27–1.49 mg L−1) and ethanolamine (3.80–17.96 mg L−1). In contrast to white wines from the Hrvatsko zagorje region, in the red wines, all biogenic amines except ethylamine, were found and equally presented.

Introduction. The elbow interposition arthroplasty is a very common procedure performed mainly on active young patients who need great functionality and for whom total joint replacement is contraindicated and arthrodesis is noncompliant. We are going to demonstrate a case of a 34-year-old male suffering from malunion of the distal humerus, elbow stiffness, and manifest signs of arthrosis of the dominant limb, treated with the IA Grika technique at a 5-year follow-up. Patients and Methods. The chosen criteria to evaluate the injured side and the uninjured side during the clinical and radiological follow-up were the objective function and related quality of life, measured by the Mayo Elbow Performance Score (MEPS), and postoperative complications. To assess flexion and supination forces and elbow muscular strength, a hydraulic dynamometer was used. Results. At a 5-year follow-up, the results were excellent as during the first year. Conclusions. The Grika technique is a valid and feasible option in the treatment of elbow injuries.

Microemulsions, which are thermodynamically stable and isotropic mixtures of water, oil, and surfactants, attract significant research interest due to their unique physicochemical properties and diverse industrial applications. Traditional surfactant-based microemulsions (SBMEs) stabilize the interface between two typically immiscible liquids, forming various microstructures such as oil-in-water (O/W) droplets, water-in-oil (W/O) droplets, and bicontinuous phases. However, the use of surfactants poses environmental concerns, cost implications, and potential toxicity. Consequently, there is increasing interest in developing surfactant-free microemulsions (SFMEs) that offer similar benefits without the drawbacks associated with surfactants. In this study, we explore the formation and characteristics of a new surfactant-free microemulsion in a ternary system comprising water, ethanol, and heptanol. Advanced techniques are employed to characterize the microstructures and stability of surfactant-free microemulsions. These include electrical conductivity measurements, surface tension analysis, dynamic light scattering (DLS), and Fourier transform infrared spectroscopy (FTIR). These methods have been extensively used in previous research on surfactant-free microemulsions (SFMEs) to reveal the properties and interactions within microemulsion systems. The area of interest is identified using these techniques, where silica nanoparticles are subsequently synthesized and then visualized using transmission electron microscopy (TEM).

Solvents prepared from natural terpenes (menthol and thymol), as H-bond acceptors, and a series of organic acids (chain lengths of 8, 10, and 14 C atoms), as H-bond donors, were characterized and tested as reaction media for liquid–liquid extraction purposes. Due to their high hydrophobicity, they seem to be promising alternatives to conventional (nonpolar and toxic) solvents, since they possess relatively less toxic, less volatile, and consequently, more environmentally friendly characteristics. Assuming that the equilibrium is established between solvent and analyte during a ligandless procedure, it can be concluded that those nonpolar solvents can efficiently extract nonpolar analytes from the aqueous environment. Previous investigations showed a wide range of applications, including their use as solvents in extractions of metal cations, small molecules, and bioactive compounds for food and pharmaceutical applications. In this work, hydrophobic solvents based on natural terpenes, which showed chemical stability and desirable physicochemical and thermal properties, were chosen as potential reaction media in the liquid–liquid extraction (LLE) procedure for Pb(II) removal from aqueous solutions. Low viscosities and high hydrophobicities of prepared solvents were confirmed as desirable properties for their application. Extraction parameters were optimized, and chosen solvents were applied. The results showed satisfactory extraction efficiencies in simple and fast procedures, followed by low solvent consumption. The best results (98%) were obtained by the thymol-based solvent, thymol–decanoic acid (Thy-DecA) 1:1, followed by L-menthol-based solvents: menthol–octanoic acid (Men-OctA) 1:1 with 97% and menthol–decanoic acid (Men-DecA) 1:1 with 94.3% efficiency.

Magnetite nanoparticles (NPs) possess properties that make them suitable for a wide range of applications. In recent years, interest in the synthesis of magnetite NPs and their surface functionalization has increased significantly, especially regarding their application in biomedicine such as for controlled and targeted drug delivery. There are several conventional methods for preparing magnetite NPs, all of which mostly utilize Fe(iii) and Fe(ii) salt precursors. In this study, we present a microwave hydrothermal synthesis for the precipitation of magnetite NPs at temperatures of 200 °C for 20 min and 260 °C for 5 min, with only iron(iii) as a precursor utilizing chamomile flower extract as a stabilizing, capping, and reducing agent. Products were characterized using FTIR, PXRD, SEM, and magnetometry. Our analysis revealed significant differences in the properties of magnetite NPs prepared with this approach, and the conventional two-precursor hydrothermal microwave method (sample MagH). FTIR and PXRD analyses confirmed coated magnetite particles. The temperature and magnetic-field dependence of magnetization indicate their superparamagnetic behavior. Importantly, the results of our study show the noticeable cytotoxicity of coated magnetite NPs—toxic to carcinoma cells but harmless to healthy cells—further emphasizing the potential of these NPs for biomedical applications.

Plant extracts are increasingly being examined in the corrosion inhibition of metal and alloys in various environments due to their potent antioxidant properties. The use of Artemisia annua L. aqueous extract (AAE) as an aluminium alloy 5083 (ALA) corrosion inhibitor in artificial seawater (ASW) was investigated using electrochemical tests and spectroscopy tools, while the active biocompounds found in AAE were analyzed using high-performance liquid chromatography (HPLC). Electrochemical results showed that AAE acts as an anodic inhibitor through the physisorption (ΔG ≈ –16.33 kJ mol−1) of extract molecules on the ALA surface, thus reducing the active sites for the dissolution of the alloy in ASW. Fourier-transform infrared spectra confirmed that phenolic acids found in AAE formed the surface layer that protects ALA against the corrosive marine environment, while HPLC analysis confirmed that the main phytoconstituents of AAE were chlorogenic acid and caffeic acid. The inhibition action of phenolic acids and their derivatives found in the AAE was based on the physisorption of caffeic acid on the ALA surface, which improved physicochemical properties of the barrier film and/or conversion of Al3+ to elemental aluminium by phenolic acids as reducens, which slowed down the diffusion rate of Al3+ to or from the ALA surfaces. The protective effect of the surface layer formed in the presence of AAE against ASW was also confirmed by inductively coupled plasma–optical emission spectrometry (ICP-OES) whereby the measured concentration of Al ions after 1 h of immersion of ALA in the pure ASW was 15.30 μg L−1 cm−2, while after the addition of 1 g L−1 AAE, the concentration was 3.09 μg L−1 cm−2.

Microwave-assisted hydrothermal synthesis is a simple, reproducible, rapid, and effective method, and therefore, has attracted considerable interest among scientists in the field of synthesis not only of iron oxide but also of other metal oxides. This method has been used for the synthesis of iron oxide nanoparticles, hematite (α-Fe2O3), and goethite (α-FeOOH) in strongly alkaline media with iron(III) chloride (FeCl3) as precursor under microwave emission of 850 W. In this work, the effect on the size, shape, and composition of the final product was investigated by changing the conditions, such as shortening the synthesis time, increasing the synthesis temperature, and adding various substances to the synthesis pathway. Samples synthesized at 200 °C for 20 min by increasing the added percentage of polyethylene glycol (PEG), sodium dodecyl sulfate (SDS), rosemary essential oil and lavender essential oil promote goethite-to-hematite transformation, while N-guanylurea sulfate (NGS) and sage essential oil behave differently. The aforementioned substances added at 260 °C resulted in a decrease in particle size, but pure hematite was obtained, regardless of the type of the substances added or the decrease in synthesis time from 20 min to 5 min. Furthermore, the use of essential oils rather than surfactants in this study was presented as a novel, environmentally friendly method of iron oxide synthesis.

Considering the vast cultural and traditional heritage of the use of aromatic herbs and wildflowers for the treatment of light medical conditions in the Balkans, a comparison of the antioxidant capacity of wildflowers extracts from Herzegovina was studied using both cyclic voltammetry and spectrophotometry. The cyclic voltammograms taken in the potential range between 0 V and 800 mV and scan rate of 100 mV s−1 were used for the quantification of the electrochemical properties of polyphenols present in four aqueous plant extracts. Antioxidant capacity expressed as mmoL of gallic acid equivalents per gram of dried weight of the sample (mmoL GAE g−1 dw) was deduced from the area below the major anodic peaks (Q400 pH 6.0, Q500 pH 4.7, Q600 pH 3.6). The results of electrochemical measurements suggest that the major contributors of antioxidant properties of examined plants are polyphenolic compounds that contain ortho-dihydroxy-phenol or gallate groups. Using Ferric reducing-antioxidant power (FRAP) and 2,2′-azino-bis spectrophotometric methods (3-ethylbenzthiazoline-6-sulphonic acid) radical cation-scavenging activity (ABTS) additionally determined antioxidant capacity. The FRAP results ranged from 2.9702–9.9418 mmoL Fe/g dw, while the results for ABTS assays expressed as Trolox equivalents (TE) ranged from 14.1842–42.6217 mmoL TE/g dw. The Folin–Ciocalteu procedure was applied to determine the total phenolics content (TP). The TP content expressed as Gallic acid equivalents (GAE) ranged from 6.0343–9.472 mmoL GAE/g dw. The measurements of total flavonoid (TF) and total condensed tannin (TT) contents were also performed to obtain a broader polyphenolic profile of tested plant materials. Origanum vulgare L. scored the highest on each test, with the exception of TT content, followed by the Mentha × piperita L., Artemisia annua L., and Artemisia absinthium L., respectively. The highest TT content, expressed as mg of (−)catechin equivalents per gram of dried weight of sample (mg CE/g dw), was achieved with A. absinthium extract (119.230 mg CE/g dw) followed by O. vulgare (90.384 mg CE/g dw), A. annua (86.538 mg CE/g dw) and M. piperita (69.231 mg CE/g dw), respectively. In addition, a very good correlation between electrochemical and spectroscopic methods was achieved.

Micellar systems are colloids with significant properties for pharmaceutical and food applications. They can be used to formulate thermodynamically stable mixtures to solubilize hydrophobic food-related substances. Furthermore, micellar formation is a complex process in which a variety of intermolecular interactions determine the course of formation and most important are the hydrophobic and hydrophilic interactions between surfactant–solvent and solvent–solvent. Glycols are organic compounds that belong to the group of alcohols. Among them, propane-1,2-diol (PG) is a substance commonly used as a food additive or ingredient in many cosmetic and hygiene products. The nature of the additive influences the micellar structure and properties of sodium dodecyl sulfate (SDS). When increasing the mass fraction of propane-1,2-diol in binary mixtures, the c.m.c. values decrease because propane-1,2-diol is a polar solvent, which gives it the ability to form hydrogen bonds, decreasing the cohesivity of water and reducing the dielectric constant of the aqueous phase. The values of ΔGm0 are negative in all mixed solvents according to the reduction in solvophobic interactions and increase in electrostatic interaction. With the rising concentration of cosolvent, the equilibrium between cosolvent in bulk solution and in the formed micelles is on the side of micelles, leading to the formation of micelles at a lower concentration with a small change in micellar size. According to the 1H NMR, with the addition of propylene glycol, there is a slight shift of SDS peaks towards lower ppm regions in comparison to the D2O peak. The shift is more evident with the increase in the amount of added propane-1,2-diol in comparison to the NMR spectra of pure SDS. Addition of propane-1,2-diol causes the upfield shift of the protons associated with hydrophilic groups, causing the shielding effect. This signifies that the alcohol is linked with the polar head groups of SDS due to its proximity to the SDS molecules.

The advantages of microwave technology over conventionally conducted experiments are numerous. Some of them are reduction in reaction time, a higher degree of process control, repeatability, and work safety. Microwave synthesis routes require a complete description of the experimental details, instrumentation, and design program of a microwave oven used in the experiments. In this work, microwave-assisted hydrothermal synthesis of hematite (α-Fe2O3) particles from 0.1 M FeCl3 solution in highly alkaline media with heating in a microwave oven at continuous microwave emission of 800 W at 150 °C, 200 °C, and 250 °C for 20 min are presented. Also, the influence of the percentage of the addition of a cationic surfactant, cetyltrimethylammonium bromide (CTAB) on the composition, size, and shape of the final product was investigated. The samples precipitated at 150 °C formed a final product consisting of goethite (α-FeOOH) and hematite particles in contrast to the those precipitated at 200 °C and 250 °C where pure hematite phase was obtained. In these synthesis routes, the CTAB caused to slow down the rate of the goethite-to-hematite transformation process at temperatures at 200 °C but did not affect the transformation at 250 °C.

A new modified ion-selective electrode with membranes of LaF3 single crystals with different internal contacts (solid steel or electrolyte) and with FexOy nanoparticles as loading was developed. The best response characteristic with linear potential change was found in the fluoride concentration range from 10−1 to 3.98 × 10−7 M. The detection limit for the electrolyte contact was determined at 7.41 × 10−8 M with a regression coefficient of 0.9932, while the regression coefficient for the solid contact was 0.9969. The potential change per concentration decade ranged from 50.3 to 62.4 mV, depending on whether the contact was solid or electrolytic. The prepared modified electrode has a long lifetime, as well as the possibility of application in different positions (solid contact), and it can also be used for the determination of iron ions. The electrode characterization was performed with scanning electron microscopy and elemental analysis with the technique of electron-dispersive X-ray spectroscopy.

Direct potentiometric method for determination of penicillamine in pharmaceuticals by using commercial copper ISE is described. Proposed method is very inexpensive, simple and reasonably fast method for determination of Pen in acetic buffer, pH = 4 without pretreatment of pharmaceuticals. Determination is based on the reaction between Pen and Cu2+ from electrode membrane. Described method has linear response range for Pen from 2×10−6 to 1×10−2 mol L−1 with limit of detection of 1.1×10−6 mol L−1. Found concentrations of Pen are in very good agreement with declared ones with standard deviation values in range 4.00−4.50 %.

Coenzyme A (CoA or CoASH) is one of the most important biologically active compounds, and for this reason a reliable, fast and simple determination of CoASH is needed. Here we are described a simple and fast way of determinating CoASH using potentiometric flow-injection analysis and spectrophotometric kinetic determination. The described methods are suitable for use over a wide concentration range (1 × 10-6–1 × 10-4 M) of CoASH.

Aim: To evaluate the effect of introducing a structured online follow-up system on the response rate., Methods: Since June 2015 we have set up an electronic follow-up system for prosthesis in orthopedic patients. This system allows prospective data gathering using both online and paper questionnaires. In the past all patients received questionnaires on paper. This study includes only patients who received elbow arthroplasty. Response rates before and after introduction of the online database were compared. After the implementation, completeness of the questionnaires was compared between paper and digital versions. For both comparisons Fisher's Exact tests were used., Results: A total of 233 patients were included in the study. With the introduction of this online follow-up system, the overall response rate increased from 49.8% to 91.6% ( P < 0.01). The response rate of 92.0% in the paper group was comparable to 90.7% in the online group ( P > 0.05). Paper questionnaires had a completeness of 54.4%, which was lower compared to the online questionnaires where we reached full completeness ( P < 0.01). Furthermore, non-responders proved to be younger with a mean age of 52 years compared to a mean age 62 years of responders ( P < 0.05)., Conclusion: The use of a structured online follow-up system increased the response rate. Moreover, online questionnaires are more complete than paper questionnaires., Competing Interests: Conflict-of-interest statement: The authors, their immediate families, and any research foundation with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article.