Nail-extraction device mismatch: an issue in developing countries intramedullary nail removal practice.

PURPOSE: Intramedullary nail is the gold standard in the management of long bone diaphyseal fractures of tibia and femur. The jig of these nails has corresponding extraction device whose pitch for nail coupling come in various sizes. This unlike plate and screws may be difficult to predict preoperatively and may pose a problem during removal. Difficulties in removal may arise due to the proliferation of nail brands especially in developing countries. The study aims to identify the incidence of extraction device mismatch among orthopaedic surgeons in Nigeria as well as the indications and complications associated with intramedullary nail removal. METHODS: A two-page questionnaire was administered to 87 orthopaedic surgeons attending the Annual General Meeting of the Nigerian Medical Association. The attitudes of the participants towards intramedullary nail were assessed. RESULTS: All participants agree to asymptomatic removal. Patients wish was the leading indication for asymptomatic removal among the participants. Sixty-one percent of the surgeons have had the need to remove a nail different from the brand in the hospital their practice. The commonest indication for symptomatic removal was infections. Forty-seven percent of the participant encountered nail extraction-device mismatch. CONCLUSIONS: The incidence of extraction device mismatch may portend a public health issue. There may be need for patient who had intra medullary nail insertion to be told their brand. We advocate for standardization of extraction device pitch for intramedullary nail.

3D printed spinning cup-shaped device for immunoaffinity solid-phase extraction of diclofenac in wastewaters.

This article reports current research efforts towards designing bespoke microscale extraction approaches exploiting the versatility of 3D printing for fast prototyping of novel geometries of sorptive devices. This is demonstrated via the so-called 3D printed spinning cup-based platform for immunoextraction of emerging contaminants using diclofenac as a model analyte. A new format of rotating cylindrical scaffold (containing a semispherical upper cavity) with enhanced coverage of biorecognition elements, and providing elevated enhancement factors with no need of eluate processing as compared with other microextraction stirring units is proposed. Two distinct synthetic routes capitalized upon modification of the acrylate surface of stereolithographic 3D printed parts with hexamethylenediamine or branched polyethyleneimine chemistries were assayed for covalent binding of monoclonal diclofenac antibody.Under the optimized experimental conditions, a LOD of 108 ng L-1 diclofenac, dynamic linear range of 0.4-1,500 µg L-1, and enrichment factors > 83 (for near-exhaustive extraction) were obtained using liquid chromatography coupled with UV-Vis detection. The feasibility of the antibody-laden device for handling of complex samples was demonstrated with the analysis of raw influent wastewaters with relative recoveries ranging from 102 to 109%. By exploiting stereolithographic 3D printing, up to 36 midget devices were fabricated in a single run with an estimated cost of mere 0.68 euros per 3D print and up to 16 €/device after the incorporation of the monoclonal antibody.

Preparation and application of a coated-fiber needle extraction device.

In this study, a needle-trap device with fibers coated with a molecularly imprinted polymer was developed for separation. A number of heat-resistant Zylon filaments were longitudinally packed into a glass capillary, followed by coating with a molecularly imprinted polymer. Then, the molecularly imprinted polymer coating was copolymerized and anchored onto the surface of the fibers. The bundle of synthetic fibers coated with the molecularly imprinted polymer was packed into a 21G stainless-steel needle and served as an extraction medium. The coated-fiber needle extraction device was used to extract volatile organic compounds from paints and gasoline effectively. Subsequently, the extracted volatile organic compounds were analyzed by gas chromatography. Calibration curves of gaseous benzene, toluene, ethylbenzene, and o-xylene in the concentration range of 1-250 µg/L were obtained to evaluate the method, acceptable linearity was attended with correlation coefficients above 0.998. The limit of detection of benzene, toluene, ethylbenzene, and o-xylene was 11-20 ng/L using the coated-fiber needle-trap device. The relative standard deviation of needle-to-needle repeatability was less than 8% with an extraction time of 20 min. The loss rates after storage for 3 and 7 days at room temperature were less than 30%.

Dynamic extraction of residual solvents from pharmaceutical formulations using a needle-type extraction device.

This study developed a rapid screening method to determine residual solvents contained in a tablet formulation using a needle-type extraction device. For this, the tablet formulation was pulverized and the powdered sample was rapidly inserted into a pipette tip. After fixing the sample with quartz wool, the pipette tip was capped with a silicon septum. A needle-type extraction device packed with Carbopack X and a carbon molecular sieve was inserted into the pipette tip through the septum, and the gas sample was collected. During this gas sampling, pure N2 gas was introduced into the pipette tip. The extraction time for collecting 100 mL of the sample was approximately 10 min. After gas sampling, the extraction needle was connected to a gas-tight syringe and 0.5 mL of pure N2 gas (desorption gas) was collected. The extraction needle was then inserted into a heated gas chromatographic injection port. The extracted residual solvents were then thermally desorbed and determined using a gas chromatograph-flame ionization detector. The detector response is very low for carbon tetrachloride, although the proposed method showed sufficient sensitivity for five Class 1 compounds. Additionally, this study clearly indicated that the purge efficiency of residual solves with dynamic extraction is different between powdered pharmaceutical formulations.

A solid-liquid microextraction approach from a spot in an adsorbent layer of a chromatographic plate.

A new approach to extracting substances from a spot on a chromatographic plate for subsequent liquid chromatography-mass spectrometry analysis is described. This method involves extraction in a solid phase (an adsorbent layer of a chromatographic plate) - a liquid system using a simple device. For a single extraction of six selected coccidiostats from the adsorbent layer on the chromatographic plate with silica gel, 50 µL of methanol was used for 5 min. The data from the extraction experiments and liquid chromatography-mass spectrometry measurements demonstrated a good correlation between the ratio of the peak areas of the coccidiostats to the internal standard and the concentration of the substances in the range of two orders of magnitude. The coefficients of determination for the mentioned correlations range from 0.962 to 0.999. Moreover, the repeatability and reproducibility, expressed as the percentage values of relative standard deviation, do not exceed 7.5 % for any of the coccidiostats.

A novel surgical technique for removal of intramedullary nails when there is a failure of the proximal extraction device: Report of two cases and review of literature.

Diaphyseal fractures of the tibia is a common injury with an incidence of 16.9/100,000 population. Surgical treatment with intramedullary interlocking nail is the treatment of choice in closed diaphyseal tibial injuries. Removal of the nail is required in non-union, infected implant, implant failure or during exchange nailing procedure. Implant removal surgery presents some unique challenges to the Orthopaedic surgeons like broken nails, broken screws and failure of the extraction devices to engage with the threads of the nail due to stripping of the threads in the proximal part of the nail. Various techniques have been described by different authors to extract a broken distal piece of the nail. There are only a few articles described for the removal of an intramedullary nail when there is failure of the proximal extraction device. The failure of the proximal extraction device occurs due to the use of ill-fitting extraction bolts, cross threading and the presence of a very tight nail leading to stripping of the proximal threads. We describe a simple and novel technique with the use of the Stainless-Steel wire along with the extraction bolt when there is a failure of proximal extraction device for the extraction of cannulated or solid intramedullary nails.

Gold nanostructured membranes to concentrate low molecular weight thiols, a proof of concept study.

Thiols are very important molecules in the biomedical field involved for example in redox homeostasis. Their detection and quantification remain difficult due to their poor stability (oxidation) linked to their strong reactivity towards other thiols (by the formation of S-S bonds) or other interfering molecules in the medium. Cellulose membranes with immobilized gold nanoparticles (AuNP) were developed to capture and quantify thiols in simple and complex matrices. This device was first optimized and characterized in terms of nanostructuration and thiol adsorption. N-Acetylcysteine (NAC) and reduced glutathione (GSH), chosen as model molecules, were filtered through the device demonstrating a maximal adsorption capacity of 270 and 60 nmol respectively. In a second step, the adsorbed species were subjected to ligand exchange using a more reactive thiol, dithiothreitol. The results showed release rates of approximately 90% for NAC and GSH. Finally, the amount of endogenous GSH in rat plasma was determined without any pretreatment. For the first time to our knowledge, a nanostructured device for the capture, selective and sensitive quantification of thiols is proposed. This device is easy to handle and overcomes matrix effects. Moreover, the very large concentration factor induced by this technology will be a valuable asset to decrease the quantification limits of analytical methods.

Development of a novel centrifugal extraction device to collect the olfactory cleft mucus.

BACKGROUND: Measuring olfactory cleft mucus biomarkers provides critical insights into the pathogenesis of the olfactory dysfunction. OBJECTIVES: This study aimed to develop a novel centrifugal extraction device to collect the olfactory cleft mucus. MATERIAL AND METHODS: The olfactory cleft mucus was collected from 18 patients with chronic rhinosinusitis (CRS) and 10 healthy controls using polyvinyl alcohol (PVA) sponges. Both novel centrifugal extraction devices and traditional devices which consisted of a falcon tube and a syringe shaft were utilized. Levels of Galectin-10 were assessed using the enzyme-linked immunosorbent assay. The olfaction was evaluated with Sniffin' Sticks. RESULTS: The average extraction efficiency of recovered volume for novel centrifugal extraction devices and traditional devices was 85.44 and 79.15%, respectively. Galectin-10 levels of the olfactory cleft mucus in patients with CRS were significantly higher than that in controls when extracted through novel devices (p < .001). Furthermore, levels of Galectin-10 in patients with CRS significantly correlated with TDI score (p = .020, r = -0.546). There was no significant difference between novel and traditional devices regarding Galectin-10 levels in CRS (p = .966). CONCLUSIONS AND SIGNIFICANCE: The novel centrifugal extraction device with PVA sponges proved to be a feasible method to collect the olfactory cleft mucus.

Outcomes of second stage cesarean section following the use of a fetal head elevation device: A systematic review and meta-analysis.

OBJECTIVES: To explore maternal and perinatal outcomes of women undergoing full dilatation cesarean section (CS) who had compared to those who did not have application of fetal head elevation device (FHED). MATERIAL AND METHODS: Pubmed, Embase, Cinahl, Clinical Trial.Gov and Google Scholar databases were searched. Inclusion criteria were studies exploring maternal and perinatal outcomes in women having compared to those not having FHED at full dilatation CS. The outcomes explored were: hysterotomy to delivery time (sec), mean estimated blood loss (ml), blood loss > 1000 mL, need for blood transfusion, uterine incision extension, operative complications, need for re-operation, urinary retention, hospital re-admission, length of in hospital stay, Apgar score < 3 at 1 min, Apgar score < 7 at 5 min, neonatal arterial Ph, arterial pH < 7.1, admission to neonatal intensive care unit (NICU), neonatal sepsis, need for neonatal endotracheal intubation, neonatal death. Random effect head-to-head meta-analyses combining summary mean difference (MD), and odd ratio (OR) were used to analyze the data. RESULTS: Ten studies (1326 women) were included. The mean time from hysterotomy to delivery was lower in women having compared to those not having FHED (MD: -52.26 s, 95 % CI -55.2 to -34.94, p < 0.001). Women who had FHED had also a lower mean estimated blood loss (MD: -130.82 mL, 95 % CI -130.1 to -381.0; p < 0.001) and a shorter stay in the hospital (MD: -0.884 h, 95 % CI -1.07 to -0.70; p < 0.001) compared to controls. Pregnant women having FHED at full dilatation CS had a lower risk of uterine incision extension (OR: 0.50, 95 % CI 0.3 to 0.9; p = 0.02), need for blood transfusion (OR: 0.39, 95 % CI 0.2 to 0.7; p = 0.04) and operative complications (OR: 0.44, 95 % CI 0.2 to 0.9; p = 0.03) compared to controls, while there was no difference in the other maternal outcomes between the two groups. When exploring perinatal outcome, women who received FHED had higher mean arterial pH values (MD: 0.617, 95 % CI 0.43 to 0.88; p < 0.001) and a lower risk of neonatal sepsis (OR: 0.10, 95 % CI 0.01 to 0.99; p = 0.05) and admission to NICU (OR: 0.63, 95 % CI 0.5 to 0.9; p = 0.008) compared to controls. CONCLUSION: Application of FHED at full dilatation CS seems to be associated with improvement in some maternal and neonatal outcomes.

A micro-solid phase extraction device to prepare a molecularly imprinted porous monolith in a facile mode for fast protein separation.

A molecularly imprinted polymeric monolith was synthesized in an aqueous environment in 15 min via UV-irradiation. The imprinted monolith was composed of hydroxyethyl methacrylate as monomer, dimethyl amino ethyl methacrylate as functional monomer, methylene bisacrylamide and piperazine diacrylamide as crosslinkers and human serum albumin as template molecule. The synthesis took place in a PDMS-based device (2.5 cm long) yielding a micro-solid phase extraction column (3 × 5 mm) with two built-in fingertight connectors for an infusion pump and fraction collector. The imprinted monolith displayed the characteristic features of a porous polymeric monolith, had dimethyl amino ethyl methacrylate and human serum albumin as functional groups within the monolith and showed high permeability (0.51 × 10-13 m2). 85% of the imprinted cavities were readily available for rebinding of human serum albumin with an imprinting factor of 1.3. In comparison to a non-imprinted monolith, molecular imprinting increased human serum albumin adsorption by > 30%. Imprinted monolith displayed selectivity for human serum albumin over other competing proteins (human transferrin, ovalbumin and carbonic anhydrase) with similar or different isoelectric points and size. Human serum albumin was adsorbed (in dynamic mode) with > 98% selectivity from diluted human plasma using the imprinted monolith device. Device to device reproducibility and reusability of the device for 5 cycles showcase the imprinted monolith micro-device efficiency.

Robotic-assisted dynamic large drop microextraction.

By proper design of an innovative extraction device, a lab-made multipurpose autosampler was exploited in the automated performance of the dynamic large drops based microextraction. The pluses of this new analytical strategy were demonstrated in the determination of sulfonamides and fluoroquinolones in surface water samples, by direct immersion single drop microextraction (SDME) and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analysis. Operational autosampler features and critical experimental factors influencing SDME, including the extraction mode (static or dynamic), extraction, stirring rate, salt addition, drop size, number of cycles and drop exposition time, were comprehensively investigated using both univariate and multivariate optimization. The lab-made autosampler allowed to performance challenging dynamic and static large drop based SDMEs in an automated and effortless way and with minimal requirements of hardware and software. Large stable drops provided high surface area, enhancing the phase ratio and in consequence increasing the analytes uptake. The best extraction efficiencies were obtained as a result of the synergic interaction between the use of large drops and the automated dynamic mode of extraction. The developed method proved to be a reliable, sensitive, and robust analytical tool, with intraday RSDs ranging between 4.0 and 7.6% (n = 6), and interday RSDs between 4.8 and 9.3% (n = 6), and, LOD and LOQ in the range of 15-50 and 35-100 ng L-1, respectively.

Determination of very volatile organic compounds in water samples by purge and trap analysis with a needle-type extraction device.

Very volatile organic compounds (VVOCs), such as methanol, acetaldehyde, ethanol, acetone, acetonitrile, and dichloromethane, were extracted from water samples using a needle-type extraction device based on purge and trap analysis. The extracted analytes could then be determined by gas chromatography-mass spectrometry. By introducing carbon molecular sieves as the extraction medium, aqueous VVOCs could be successfully extracted using the extraction needle. The limit of quantification for methanol, acetaldehyde, ethanol, acetone, acetonitrile, and dichloromethane were 75, 75, 7.5, 0.5, 10 and 0.5 µg/L, respectively. This newly developed method was also successfully applied to the determination of VVOCs in commercial samples, such as fruit juice.

Green aspects, developments and perspectives of liquid phase microextraction techniques.

Determination of analytes at trace levels in complex samples (e.g. biological or contaminated water or soils) are often required for the environmental assessment and monitoring as well as for scientific research in the field of environmental pollution. A limited number of analytical techniques are sensitive enough for the direct determination of trace components in samples and, because of that, a preliminary step of the analyte isolation/enrichment prior to analysis is required in many cases. In this work the newest trends and innovations in liquid phase microextraction, like: single-drop microextraction (SDME), hollow fiber liquid-phase microextraction (HF-LPME), and dispersive liquid-liquid microextraction (DLLME) have been discussed, including their critical evaluation and possible application in analytical practice. The described modifications of extraction techniques deal with system miniaturization and/or automation, the use of ultrasound and physical agitation, and electrochemical methods. Particular attention was given to pro-ecological aspects therefore the possible use of novel, non-toxic extracting agents, inter alia, ionic liquids, coacervates, surfactant solutions and reverse micelles in the liquid phase microextraction techniques has been evaluated in depth. Also, new methodological solutions and the related instruments and devices for the efficient liquid phase micoextraction of analytes, which have found application at the stage of procedure prior to chromatographic determination, are presented.

Needle-type extraction device for the purge and trap analysis of 23 volatile organic compounds in tap water.

We developed a rapid determination technique for trace volatile organic compounds (VOCs) in tap water by introducing a novel needle-type extraction device coupled to a purge-and-trap method. To extract a wide range of VOCs, a new extraction needle containing particles of divinylbenzene and activated carbon was developed in this study. During the active sampling of the headspace gas in a glass vial by the extraction needle, pure N2 gas was used for purging the aqueous sample. After the optimization of several experimental parameters, such as the addition of the salt and conditions of dry purging and desorption, the extraction performance of the device and method was evaluated for 23 VOCs that are typically found in tap water samples. The quantification limits of the method were 0.6 µg/L for 1,1-dichloroethylene and less than 0.5 µg/L for other VOCs, with good repeatability being confirmed for all the target compounds. Taking advantage of the excellent recovery of VOCs, the determination of VOCs in real tap water samples was carried out successfully. Because the developed method does not require sample heating and/or cryogenic focusing, simple and rapid analyses can be performed along with satisfactory sensitivity for typical tap water samples.