Publications by authors named "Ioannis Ignatiadis"

Mercury pollution from natural and anthropogenic sources demands effective remediation. This study focuses on optimizing a chemical stabilization approach using sulfur-containing compounds to create stable mercury sulfide (HgS) and immobilize elemental mercury in polluted soils. We propose using xanthan gum biopolymer to enhance the in-situ delivery of sulfide microparticles, overcoming soil heterogeneities due to its non-Newtonian behavior.

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Ground surface analysis of CO emissions with δC determination is experimentally demonstrated to be a potential methodology to monitor, on line, the dynamics of petroleum-hydrocarbon biodegradation in soil aquifers, thanks to the improvement of the Isotopic Ratio Infra Red Spectroscopy technique. Biodegradation rate of remaining hydrocarbon substrates in groundwater can be quantified using basic application of the Rayleigh equations, by δC analysis released at ground surface above the pollution plume instead of usual approaches based on groundwater hydrocarbons δC analysis, when physical and chemical properties for the contaminated site meet appropriate conditions. The validation approach for that gasoline contaminated specific site is discussed and verified by comparison of first order attenuation rate constant determined from δC analysis emitted at ground surface and from δC analysis in ground water.

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Biosurfactants, surface-active agents produced by microorganisms, are increasingly studied for their potential use in soil remediation processes because they are more environmentally friendly than their chemically produced homologues. In this work, we report on the use of a crude biosurfactant produced by a bacterial consortium isolated from a PAHs-contaminated soil, compared with other (bio)surfactants (Tween80, Sodium dodecyl sulfate - SDS, rhamnolipids mix), to wash PAHs from a contaminated porous media. Assays were done using columns filled with sand or sand-clay mixtures (95:5) spiked with four model PAHs.

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Co/Fe-based layered double hydroxides (LDHs) are among the most promising materials for electrochemical applications, particularly in the development of energy storage devices, such as electrochemical capacitors. They have also been demonstrated to function as energy conversion catalysts in photoelectrochemical applications for CO2 conversion into valuable chemicals. Understanding the formation mechanisms of such compounds is therefore of prime interest for further controlling the chemical composition, structure, morphology, and/or reactivity of synthesized materials.

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Studying the electrogravimetric behavior of Mg/Fe-layered double hydroxide (LDH) nanoparticles with an electrochemical quartz crystal microbalance demonstrates its pseudocapacitance properties of mix cation and anion exchanger. The electrochemical control of the oxidation state of iron constituting the layered sheets allowed anion intercalation/deintercalation into the LDH interlayer space. Concomitantly, in agreement with the pH of zero point of net charge of the Mg/Fe-LDH, the interfacial pH increase via catalyzed hydrogen evolution reaction allows cation electroadsorption onto the external surfaces of the nanoplatelets.

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We report the case of a 40 year-old male with Staphylococcus aureus osteomyelitis of the proximal humerus after open reduction and internal fixation of a fracture from motor vehicle accident. Removal of the osteosynthesis, extensive debridement and intravenous antibiotics administration was done followed by external fixation stabilization and reconstruction with a combined pedicled flap using the serratus anterior reversed flap and the 6th rib. At the last follow-up, healing of the bone flap was observed; the patient experienced useful motion of his upper extremity without any evidence of recurrent infection.

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Biosurfactants are surface-active agents produced by microorganisms whose use in soil remediation processes is increasingly discussed as a more environmentally friendly alternative than chemically produced surfactants. In this work, we report the production of a biosurfactant by a bacterial community extracted from a polluted soil, mainly impacted by PAHs, in order to use it in a soil-washing process coupled with bioremediation. Nutrient balance was a critical parameter to optimize the production.

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Free flaps are the gold standard for reconstruction of the mandible, tongue and floor of the mouth. Free fibular flaps are the most preferable option for reconstruction of complex mandibular defects, as well as for tongue and mouth floor reconstruction, since they are harvested easily, present excellent sculptability and good functional outcomes. Alternative options for bone reconstruction include the fibular and iliac crest free flap, and for soft tissue reconstruction include the anterolateral thigh, the radial forearm free flap, and the nasolabial island flap.

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The degradation mechanism of the pollutant hexachloroethane (HCA) by a suspension of Pd-doped zerovalent iron microparticles (Pd-mZVI) in dissolved lactic acid polymers and oligomers (referred to as PLA) was investigated using gas chromatography and the indirect monitoring of iron corrosion by continuous measurements of pH, oxidation-reduction potential (ORP), and conductivity. The first experiments took place in the absence of HCA, to understand the evolution of the Pd-mZVI/PLA/HO system. This showed that the evolution of pH, ORP, and conductivity is related to changes in solution chemistry due to iron corrosion and that the system is initially cathodically controlled by H mass transport to Pd surfaces because of the presence of an extensive PLA layer.

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Microsurgery is a term used to describe the surgical techniques that require an operating microscope and the necessary specialized instrumentation, the three "Ms" of Microsurgery (microscope, microinstruments and microsutures). Over the years, the crucial factor that transformed the notion of microsurgery itself was the anastomosis of successively smaller blood vessels and nerves that have allowed transfer of tissue from one part of the body to another and re-attachment of severed parts. Currently, with obtained experience, microsurgical techniques are used by several surgical specialties such as general surgery, ophthalmology, orthopaedics, gynecology, otolaryngology, neurosurgery, oral and maxillofacial surgery, plastic surgery and more.

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Gunshot wounds and blast injuries constitute a major public health problem, as the increasing availability of firearms and explosives in conjunction with increasing violence in the city setting have brought this reality into civilian life. Extremities are most commonly involved; therefore, orthopedic surgeons should be trained to manage these types of injuries. Complete and accurate assessment of the injury itself is of great importance, as it will determine the severity and the risk of patients.

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In microsurgical nerve repair, the epineural sleeve technique can be used to bridge short nerve defects and to cover the coaptation site with the epineurium of the nerve stump. The epineurium serves as a mechanical aid to reduce gap size, and increase repair strength, effectively assisting nerve regeneration. This article presents a 32-year-old patient who experienced complete transection of the median nerve at the distal forearm, which was treated with the epineural sleeve graft reconstruction technique.

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We present an innovative electrochemical probe for the monitoring of pH, redox potential and conductivity in near-field rocks of deep geological radioactive waste repositories. The probe is composed of a monocrystalline antimony electrode for pH sensing, four AgCl/Ag-based reference or Cl selective electrodes, one Ag₂S/Ag-based reference or S selective electrode, as well as four platinum electrodes, a gold electrode and a glassy-carbon electrode for redox potential measurements. Galvanostatic electrochemistry impedance spectroscopy using AgCl/Ag-based and platinum electrodes measure conductivity.

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Here, we present a surface-enhanced Raman spectroscopy (SERS) nanosensor for environmental pollutants detection. This study was conducted on three polycyclic aromatic hydrocarbons (PAHs): benzo[a]pyrene (BaP), fluoranthene (FL), and naphthalene (NAP). SERS substrates were chemically functionalized using 4-dodecyl benzenediazonium-tetrafluoroborate and SERS analyses were conducted to detect the pollutants alone and in mixtures.

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A model was developed to describe how the 2:1 layer excess negative charge induced by the reduction of Fe(III) to Fe(II) by sodium dithionite buffered with citrate-bicarbonate is balanced and applied to nontronites. This model is based on new experimental data and extends structural interpretation introduced by a former model [36-38]. The 2:1 layer negative charge increase due to Fe(III) to Fe(II) reduction is balanced by an excess adsorption of cations in the clay interlayers and a specific sorption of H(+) from solution.

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So far, predictive models with individualized estimates of prognosis for patients with peripheral nerve injuries are lacking. Our group has previously shown the prognostic value of a standardized scoring system by examining the functional outcome after acute, sharp complete laceration and repair of median and/or ulnar nerves at various levels in the forearm. In the present study, we further explore the potential mathematical model in order to devise an effective prognostic scoring system.

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Improved tendon-to-tendon suturing techniques allow for consistent and immediate activation of transferred muscle after surgery. A pre-requisite for early training after tendon transfer surgery is sufficient mechanical integrity of the tendon-to-tendon attachment. This in vitro study compared the mechanisms and magnitudes of load-to-failure response of two different repair techniques (side-to-side running, n = 7) and weave sutures (n = 8) in sheep front foot tendons.

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Extrinsic chronic nerve compression induced by nonendothelium derived vascular tumors is a rare occurrence at the forearm level. We present a case of severe chronic compression of the radial sensory nerve (RSN) caused by an undiagnosed venous glomangioma. The tumor was excised with complete symptoms relief.

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The purpose of this study was to evaluate the effect of direct administration of nerve growth factor (NGF) into an epineural conduit across a short nerve gap (10 mm) in a rabbit sciatic nerve model. The animals were divided into two groups. In group 1, n = 6, a 10-mm defect was created in the sciatic nerve and bridged with an epineural flap.

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A comparison of outcomes based on a scoring system for assessments, described by Rosén and Lundborg, after sharp complete laceration of median and/or ulnar nerves at various levels in the forearm was carried out. There were 66 males (90.4%) and 7 females (9.

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Article Synopsis
  • The study examines long-term outcomes of 44 patients with post-traumatic bone defects treated using muscle-rib flaps from March 1997 to December 2007.
  • It involved various flap types: 21 serratus anterior-rib (SA-R), 10 latissimus dorsi-rib (LD-R), and 13 combined LD-SA-R flaps, applied to both upper (18 cases) and lower limbs (26 cases).
  • The procedures demonstrated a high immediate success rate of 95.4% and a primary bone union rate of 97.7%, supporting the efficacy of this method for addressing small to medium bone defects coupled with significant soft tissue issues.
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Plastic reconstruction for diabetic foot wounds must be approached carefully and follow sound micro-surgical principles as it relates to the anatomy of the designated flap chosen for coverage. First, the surgeon always needs to evaluate the local and general conditions of the presenting pathology and patient, respectively when considering a flap for reconstruction. The flap that is chosen is based on the vascularity, location, and size of the defect.

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The authors present their experience with the use of sural fasciocutaneous flaps for the treatment of various soft tissue defects in the lower limb. This paper is a review of these flaps carried out between 2003 and 2008. The series consists of 16 patients, 11 men and 5 women with an average age of 41 years (17-81) and with a follow-up period between 2 and 7 years.

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The treatment of 31 consecutive adult patients, ages 25-67 years with chronic draining osteomyelitis (12 cases) or infected pseudarthrosis (19 cases) by the Papineau technique was retrospectively reviewed. The initial injury was an open fracture in 24 patients and a closed fracture in 7 patients. In all cases an Ilizarov circular external fixation device was used for the stabilization of the fracture or for bone lengthening.

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Management of Achilles tendon and heel area defects is a common challenge for the reconstructive surgeon due to the lack of soft tissue availability in that region. In this article, we present our experience in covering these defects by using the distal perforator propeller flaps based on the posterior tibial artery. Perforator flaps are based on cutaneous, small diameter vessels that originate from a main pedicle and perforate the fascia or muscle to reach the skin.

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