Gunshot and blast injuries of the extremities: a review of 45 cases.

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. High-risk injuries from missiles and injuries from explosions are associated with moderate or poor outcomes, major complications, and increased need for multiple surgical procedures. On the other hand, low-risk injuries frequently present optimal results and rather low morbidity. The role of microsurgery is essential, especially in the high- and very high-risk injuries, since complex and multiple reconstructions have to be performed, which include the utilization of free flaps, nerve grafts, and tendon transfers.

The history of microsurgery.

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. This article highlights the most important innovations and milestones in the history of microsurgery through the ages that allowed the inauguration and establishment of microsurgical techniques in the field of surgery.

A Multi-Parametric Device with Innovative Solid Electrodes for Long-Term Monitoring of pH, Redox-Potential and Conductivity in a Nuclear Waste Repository.

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 S2- 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. The use of such a multi-parameter probe provides redundant information, based as it is on the simultaneous behaviour under identical conditions of different electrodes of the same material, as well as on that of electrodes made of different materials. This identifies the changes in physical and chemical parameters in a solution, as well as the redox reactions controlling the measured potential, both in the solution and/or at the electrode/solution interface. Understanding the electrochemical behaviour of selected materials thus is a key point of our research, as provides the basis for constructing the abacuses needed for developing robust and reliable field sensors.

Diazonium Salt-Based Surface-Enhanced Raman Spectroscopy Nanosensor: Detection and Quantitation of Aromatic Hydrocarbons in Water Samples.

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. Compounds were first measured in water-methanol (9:1 volume ratio) samples. Investigation on solutions containing concentrations ranging from 10-6 g L-1 to 10-3 g L-1 provided data to plot calibration curves and to determine the performance of the sensor. The calculated limit of detection (LOD) was 0.026 mg L-1 (10-7 mol L-1) for BaP, 0.064 mg L-1 (3.2 × 10-7 mol L-1) for FL, and 3.94 mg L-1 (3.1 × 10-5 mol L-1) for NAP, respectively. The correlation between the calculated LOD values and the octanol-water partition coefficient (Kow) of the investigated PAHs suggests that the developed nanosensor is particularly suitable for detecting highly non-polar PAH compounds. Measurements conducted on a mixture of the three analytes (i) demonstrated the ability of the developed technology to detect and identify the three analytes in the mixture; (ii) provided the exact quantitation of pollutants in a mixture. Moreover, we optimized the surface regeneration step for the nanosensor.

Biopolymer-enhanced delivery of reactive sulfide reagents for in-situ mercury remediation of heterogeneous contaminated soils.

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. Stability tests indicated that increased biopolymer concentration enhances particle stability due to the viscous and shear-thinning behavior of the polymer solutions. Various combinations (12 solutions) of xanthan polymer, pyrite microparticles, and sulfide-containing reagents were tested in batch experiments. Pyrite microparticles slightly reduced the xanthan solution's viscosity while retaining its non-Newtonian character. All solutions effectively transformed liquid mercury droplets into cinnabar, demonstrating successful mercury stabilization. Notably, solutions containing PIAX and SIPX, xanthate organosulfur compounds, significantly reduced the dissolved concentration of elemental mercury. Column experiments demonstrated xanthan gum's superior performance for in-situ injection of pyrite microparticles and sulfide mixtures into the soil compared to conventional water injection. At a polymer concentration of 4 g/L, a stable displacement front and an 88 % recovery of the initially injected particle-suspension density were achieved. The combined effects of xanthate's floating behavior and xanthan gum's shear-thinning nature substantially enhanced the delivery of pyrite microparticles in porous media for soil mercury remediation. This combination reduced the aqueous elemental mercury concentration in artificially polluted sand by up to 97 %, particularly with the xanthate organosulfur compound, PIAX. Xanthate has a higher potential to react with elemental mercury to form cinnabar compared to sodium thiosulfate. Additionally, the pyrite microparticles, rendered hydrophobic in xanthate solutions, integrated into the mercury droplets, forming a black paste. This study introduces a promising approach for efficient elemental mercury stabilization in contaminated soils by integrating biopolymers, reactive soluble compounds, and pyrite microparticles for sustainable decontamination.

Prognostic scoring system for peripheral nerve repair in the upper extremity.

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. We retrospectively collected medical record data of 73 cases with a peripheral nerve injury in the upper extremity in order to estimate which patients would return to work, and what time was necessary to return to the pre-injury work. Postoperative assessment followed the protocol described by Rosén and Lundborg. We found that return to pre-injury work can be predicted with high sensitivity (100%) and specificity (95%) using the total numerical score of the Rosén and Lundborg protocol at the third follow-up interval (TS3) as well as the difference between the TS3 and the total score at second follow-up interval (TS2). In addition, the factors age and type of injured nerve (median, ulnar, or combined) can determine the time of return to work based on a mathematical model. This prognostic protocol can be a useful tool to provide information about the functional and social prospects of the patients with these types of injuries.

Quantification of biodegradation rate of hydrocarbons in a contaminated aquifer by CO2 δ13C monitoring at ground surface.

Ground surface analysis of CO2 emissions with δ13C 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 δ13CCO2 analysis released at ground surface above the pollution plume instead of usual approaches based on groundwater hydrocarbons δ13C 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 δ13CCO2 analysis emitted at ground surface and from δ13CTOLUENE analysis in ground water. A kinetic fractionation factor α of 0.9979 (or ε value of -2.1 ± 0.5‰) is estimated for the biodegradation of the most reactive hydrocarbon substrates (TEX). The treatment of this Rayleigh equations by linear regression of δ13CCO2 values along the predominant direction of groundwater flow leads to the following results and conclusions for that site: (i) first order biodegradation rate constants (and annual variation) are maximum after the activation of a Permeable Reactive Barrier (PRB) in May 2014: 0.92(+0.29-0.17) year-1, and during July and October: 0.46(+0.14-0.09) year-1 and minimum in mid-winter in February 2015: 0.17(+0.05-0.03) year-1, given by the estimation range for ε. These results are in the lower range with reported in literature for similar contaminated sites (1.6-18 year-1) considering natural attenuation under sulfate reducing conditions and (ii) the seasonal variation of the first order biodegradation rate constant is mainly correlated with the seasonal variation of the CO2 flux, where maximum values are in summers and minimum values in winters. Both seasonal variations are mainly due to the annual cycle of the natural biodegradation activity at the scale of the pollution plume, rather than the activation of the PRB. This work demonstrates that δ13CCO2 analysis released at ground surface from biodegradation of groundwater hydrocarbons could provide, under characterized and appropriate conditions, a non-intrusive (without soil samplings), fast, and low-cost online method to monitor and therefore to optimize soil remediation processes in real time. (Monitored Natural Attenuation or Enhanced Bioremediation).

Atypical venous glomangioma causing chronic compression of the radial sensory nerve in the forearm. A case report and review of the literature.

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. In the presence of severe nerve compression syndromes in young age, without predisposing comorbidities, atypical extrinsic compression due to vascular tumors should be considered.

Comprehension of the Route for the Synthesis of Co/Fe LDHs via the Method of Coprecipitation with Varying pH.

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. In this study, a combination of X-ray diffraction, vibrational and absorption spectroscopies, as well as physical and chemical analyses were used to provide deep insight into the coprecipitation formation mechanisms of Co/Fe-based LDHs under high supersaturation conditions. This procedure consists of adding an alkaline aqueous solution (2.80 M NaOH and 0.78 M Na2CO3) into a cationic solution (0.15 M CoII and 0.05 M FeIII) and varying the pH until the desired pH value is reached. Beginning at pH 2, pH increases induce precipitation of FeIII as ferrihydrite, which is the pristine reactional intermediate. From pH > 2, CoII sorption on ferrihydrite promotes a redox reaction between FeIII of ferrihydrite and the sorbed CoII. The crystallinity of the poorly crystalized ferrihydrite progressively decreases with increasing pH. The combination of such a phenomenon with the hydrolysis of both the sorbed CoIII and free CoII generates pristine hydroxylated FeII/CoIII LDHs at pH 7. Above pH 7, free CoII hydrolysis proceeds, which is responsible for the local dissolution of pristine LDHs and their reprecipitation and then 3D organization into CoII4FeII2CoIII2 LDHs. The progressive incorporation of CoII into the LDH structure is accountable for two phenomena: decreased coulombic attraction between the positive surface-charge sites and the interlayer anions and, concomitantly, the relative redox potential evolution of the redox species, such as when FeII is re-oxidized to FeIII, while CoIII is re-reduced to CoII, returning to a CoII6FeIII2 LDH. The nature of the interlamellar species (OH−, HCO3−, CO32− and NO3−) depends on their mobility and the speciation of anions in response to changing pH.

Polycyclic aromatic hydrocarbons remobilization from contaminated porous media by (bio)surfactants washing.

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. The crude biosurfactant showed less adsorption to the [sand] and the [sand + clay] columns compared to Tween 80, SDS and the rhamnolipid mix. The biosurfactant showed the second best capacity to remove PAHs from the columns (as dissolved and particulate phases), both from [sand] and [sand + clay], after SDS when applied at lower concentrations than the other sufactants. The effluent concentrations of phenanthrene (PHE), pyrene (PYR) and benzo[a]pyrene (BAP) increased in the presence of the crude biosurfactant. Compared to the control experiment using only water, the global PAHs washed mass (amount of PAHs removed from the columns) increased between 9 and 1000 times for PHE and BAP in the [sand] column, and between 55 and 6000 times respectively for PHE and BAP in the [sand + clay] columns. Moreover, in the [sand + clay] columns, leaching of a part of the clays was observed in the SDS and the biosurfactant injections assays. This clay leaching resulted in higher PAHs removal, due not to desorption but rather to particulate transport. In the context of washing PAH-contaminated soils in biopiles or subsurface remediation, our results could help in sizing the remediation approach using an environmental friendly biosurfactant, before a pump-and-treat process.

Nerve growth factor combined with an epineural conduit for bridging a short nerve gap (10 mm). A study in rabbits.

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. A dose of 1 µg of NGF was locally administered daily for the first 21 days. NGF administration was made inside the epineural flap using a silicone reservoir connected to a silicone tube. In group 2, n = 6, the 10-mm defect was bridged with a nerve graft. This group did not receive any further treatment. At 13 weeks, all animals, before euthanasia, underwent electromyography (EMG) studies and then specimen sent for histology morphometric analysis. NGF administration ensured a significantly increased average number of myelinated axons per µm(2) (P = 0.028) and promoted fiber maturation (P = 0.031) and better EMG results (P = 0.046 for latency P = 0.048 for amplitude), compared with the control group. Although nerve grafts remain the gold standard for peripheral nerve repair, NGF-treated epineural conduits represent a good alternative, particularly when an unfavorable environment for nerve grafts is present.

Long-term results after muscle-rib flap transfer for reconstruction of composite limb defects.

The authors present the long-term results in a series of 44 cases with post-traumatic bone defects solved with muscle-rib flaps, between March 1997 and December 2007. In these cases, we performed 21 serratus anterior-rib flaps (SA-R), 10 latissimus dorsi-rib flaps (LD-R), and 13 LD-SA-R. The flaps were used in upper limb in 18 cases and in lower limb in 26 cases. With an overall immediate success rate of 95.4% (42 of 44 cases) and a primary bone union rate of 97.7% (43 of 44 cases), and despite the few partisans of this method, we consider that this procedure still remains very usefully for small and medium bone defects accompanied by large soft tissue defects.

Repair of complete nerve lacerations at the forearm: an outcome study using Rosén-Lundborg protocol.

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 (9.6%), with a mean age of 31 years (range: 14-62 years). The patients were categorized into three groups according to the type of nerve injury. The median nerve was injured in 25 cases (group M, 34.3%), the ulnar in 27 (group U, 36.9%), and both the nerves in 21 (group MU, 28.8%). The demographic data of the patients and the mechanism of injury were recorded. We also examined the employment status at the time of the injury and we estimated the percentage of patients who returned to their work after trauma. In all cases, a primary epineural repair was performed. Concomitant injuries were repaired in the same setting. The mean period of time between injury and surgery was 5.3 hours (range: 2-120 hours). A rehabilitation protocol and a reeducation program were followed in all cases. The mean follow-up was 3 years (range: 2-6 years), with more distal injuries having a shorter follow-up period. The total score was 2.71 in group M (range: 0.79-2.99) and 2.63 in group U (range: 0.63-3), with no significant differences observed. There was a significant difference between these two groups and group MU (total score 2.03, range: 0.49-2.76, P = 0.02). Up to the last follow-up, 61 patients (83.5%) had returned to their previous work. The Rosén-Lundborg model can be a useful and simple tool for the evaluation of the functional outcome after nerve injury and repair temporally reflecting the processes of regeneration and reinnervation.

Tuning Redox State and Ionic Transfers of Mg/Fe-Layered Double Hydroxide Nanosheets by Electrochemical and Electrogravimetric Methods.

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.

Composite rib and serratus anterior pedicle transfer for reconstruction of an osteomyelitis of the humerus.

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.

Production of biosurfactant using the endemic bacterial community of a PAHs contaminated soil, and its potential use for PAHs remobilization.

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. Best conditions for biosurfactant production were found to be 20 g/L of glucose, 2 g/L of NH4NO3, and 14.2 g/L of Na2HPO4, corresponding to a C/N/P molar ratio equal to 13/1/2. Purification of the produced biosurfactant by acidification and double extraction with dichloromethane as a solvent allowed measuring the Critical Micellar Concentration (CMC) as equal to 42 mg/L. The capacity of the purified biosurfactant to increase the apparent solubility of four reference PAHs (naphthalene, phenanthrene, pyrene and benzo[a]pyrene) was completed. The solubilisation ratios, in mg of PAH/g of biosurfactant for phenanthrene, pyrene and benzo[a]pyrene are 0.214, 0.1204 and 0.0068, respectively. Identification of the bacteria found in the colony producing the biosurfactant showed the presence of bacteria able to produce biosurfactant (Enterobacteriaceae, Pseudomonas), as well as, others able to degrade PAHs (Microbacterium, Pseudomonas, Rhodanobacteraceae).

Partial fasciectomy for Dupuytren's contractures.

One hundred ninety-six patients with Dupuytren's contractures were treated by partial fasciectomy and adequate postoperative rehabilitation. All patients had flexion contracture of the proximal interphalangeal joint of >20 degrees ; 93 patients had flexion contracture of the associated metacarpophalangeal joint of >30 degrees ; 143 patients had risk factors for Dupuytren's disease. Primary skin closure and splinting were done in all patients. Range of motion was begun by the 1st week. Splinting was discontinued by the 2nd week, followed by night-time splinting until the 8th week. The mean follow-up was 6.6 years (range, 2-9 years). At the latest examination, 72.5% of the patients had complete range of motion of the metacarpophalangeal and proximal interphalangeal joints; 20.2% had 5 degrees -10 degrees of extension deficit and 7.3% had recurrent contractures of >20 degrees at the proximal interphalangeal joint and were subjected to reoperation. Complications included digital neurovascular injury in 5%, complex regional pain syndrome in 10.1%, and wound-healing problems and superficial infections in 15.1%.

Elucidating the dechlorination mechanism of hexachloroethane by Pd-doped zerovalent iron microparticles in dissolved lactic acid polymers using chromatography and indirect monitoring of iron corrosion.

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/H2O 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. We then investigated the effects of Pd-mZVI particles, temperature, initial HCA concentration, and PLA content on the Pd-mZVI/PLA/HCA/H2O system, to obtain a better understanding of the degradation mechanism. In all cases, HCA dechlorination first requires the production of atomic hydrogen H*-involving the accumulation of tetrachloroethylene (PCE) as an intermediate-before its subsequent reduction to non-chlorinated C2 and C4 compounds. The ratio between Pd-mZVI dosage, initial HCA concentration, and PLA content affects the rate of H* generation as well as the rate-determining step of the process. A pseudo-first-order equation can be applied when Pd-mZVI dosage is much higher than the theoretical stoichiometry (600 mg for [HCA]0 = 5-20 mg L-1). Our results indicate that the HCA degradation mechanism includes mass transfer, sorption, surface reaction with H*, and desorption of the product.

Microsurgical reconstruction of complex oromandibular defects: An update.

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. The principles of the surgical approach include resection of the mandibular segment, intraoperative evaluation of the defect, and various surgical manipulations of the flap on site to reconstruct the defect. Advances in computerized preoperative planning have allowed virtual simulation of the defect and fabrication of an individualized stereolithic mandibular model. This short review discusses the current trends of bone and soft tissue flaps for complex oromandibular reconstructions aiming to present a comprehensive review that the readers would find interesting and informative.

Severe upper limb injuries with or without neurovascular compromise in children and adolescents--analysis of 32 cases.

The healing and regeneration capacity of the injured tissues in childhood, adolescence, and adult life differs significantly. As a result, the prognosis of compound injuries of the upper limb in different age groups varies; therefore, the decision making and management of these cases should be age-specific. This article presents a series of 32 patients aged 1.5-14 years, with compound injuries of the upper limb that have been treated in our hospital during the period of the last 6 years. Ten of the above cases involved major vascular lesions that required revascularization or replantation. The injuries were classified according to the SATT (Severity, Anatomy, Topography, Type) classification system. This study shows that the outcome of compound upper limb injuries is age-related, while the SATT classification system is a valuable tool in the decision making process. Further research should be undertaken to determine age group-specific indications for the management of compound upper limb injuries, based on the SATT classification system.