Open fractures of the limbs in children and adolescents.

Open fracture is rare in children, raising dual issues of sepsis and mechanics. Here, we address certain practical questions regarding childhood open fracture. Should the recognized adult classifications be used in children? Two classifications exist for adults, without pediatric specificities; of these, we recommend Gustilo's, as being more precise in its description of severe grades. Is there any consensus on emergency prophylactic antibiotic therapy in children? The risks seem to be the same, and 24hours' prophylactic antibiotic therapy should be initiated as soon as possible, as in adults. What are the most recent guidelines on time to treatment, type of internal fixation and possible associated procedures in tibial fracture in children? Wound cleansing is indispensable. Treatment under anesthesia can be delayed up to 24hours in the absence of neurovascular complications on condition that antibiotic therapy is implemented immediately. In Gustilo grade I and II, or IIIA, external fixation is not systematic and non-operative treatment or intramedullary nailing is possible. In grades IIIB and IIIC, external fixation is the rule, although conversion is possible if indicated early enough. Do the particular cases of nail bed injury or lawn mower foot injury in children require specific management? Nail bed injury is not to be minimized and should be treated strictly. In case of serious accidents with garden equipment, initial wound care in surgery should be economic, but experienced practitioners should weigh the risk/benefit ratio between conservation and early amputation. LEVEL OF EVIDENCE: IV.

Composition Effect on the Formation of Oxide Phases by Thermal Decomposition of CuNiM(III) Layered Double Hydroxides with M(III) = Al, Fe.

The thermal decomposition processes of coprecipitated Cu-Ni-Al and Cu-Ni-Fe hydroxides and the formation of the mixed oxide phases were followed by thermogravimetry and derivative thermogravimetry analysis (TG - DTG) and in situ X-ray diffraction (XRD) in a temperature range from 25 to 800 °C. The as-prepared samples exhibited layered double hydroxide (LDH) with a rhombohedral structure for the Ni-richer Al- and Fe-bearing LDHs and a monoclinic structure for the CuAl LDH. Direct precipitation of CuO was also observed for the Cu-richest Fe-bearing samples. After the collapse of the LDHs, dehydration, dehydroxylation, and decarbonation occurred with an overlapping of these events to an extent, depending on the structure and composition, being more pronounced for the Fe-bearing rhombohedral LDHs and the monoclinic LDH. The Fe-bearing amorphous phases showed higher reactivity than the Al-bearing ones toward the crystallization of the mixed oxide phases. This reactivity was improved as the amount of embedded divalent cations increased. Moreover, the influence of copper was effective at a lower content than that of nickel.

Functional and radiological outcome of subtalar arthroereisis for flexible pes planovalgus in children: A retrospective analysis.

INTRODUCTION: Pediatric idiopathic pes planovalgus can correct itself with growth. Otherwise, in the event of functional impairment and after failed conservative treatment, surgery can be considered. Based on a multicenter retrospective study, we report the functional and radiographic results obtained after subtalar arthroereisis. HYPOTHESIS: We hypothesized that this surgery improves functional and radiological parameters in childhood. MATERIAL AND METHOD: Forty-eight medical records of children (78 feet) operated on between 2010 and 2019 were studied. Functional (FAOS score) and radiographic (Djian angle, calcaneal slope, lateral talocalcaneal divergence and calcaneus/M5 alignment, talonavicular coverage measurement, AP talocalcaneal divergence) results were studied. The analysis of these different criteria was carried out between the preoperative period and the last follow-up. RESULTS: The functional outcome was satisfactory with an average FAOS questionnaire score of 95.5 out of 100 total points. All the radiographic parameters studied were significantly improved (p<0.001). The average age at the time of surgery was 11.3 years (range: 7 to 16) with a mean follow-up of 35 months (range: 18 months to 84). Spontaneous screw expulsion and subtalar pain were the main complications found. DISCUSSION: The results obtained are consistent with those in the literature. The age at the time of the surgery is an essential factor to consider with the goal of optimal correction. CONCLUSION: This technique is reliable and effective in the short term. It can be offered as first-line therapy in the management of symptomatic pes planovalgus in children. The follow-up is short, which necessitates longer term studies of this population. The ideal age for surgery remains to be determined. LEVEL OF EVIDENCE: IV.

[Bone lengthening by motorized centromedullary nail]. / L'allongement osseux par clou centromédullaire motorisé magnétique.

Bone lengthening surgeries are difficult procedures for both the patient and the professional. Complications are common and pediatric orthopedists have been working to reduce them. The discovery of progressive bone lengthening was a first step in improving these procedures, followed by the advent of external fixators. More recently, internal lengthening systems have emerged as one of the greatest technological advances in these procedures. Bone lengthening with an electromagnetic nail, which is becoming increasingly popular, has drastically reduced the complications of these surgeries.

Stacking Versatility in Alkali-Mixed Honeycomb Layered NaKNi2TeO6.

The reaction between P2-type honeycomb layered oxides Na2Ni2TeO6 and K2Ni2TeO6 enables the formation of NaKNi2TeO6. The compound is characterized by X-ray diffraction and 23Na solid-state nuclear magnetic resonance spectroscopy, and the structure is discussed through density functional theory calculations. In addition to the honeycomb Ni/Te cationic ordering, NaKNi2TeO6 exhibits a unique example of alternation of sodium and potassium layers instead of a random alkali-mixed occupancy. Stacking fault simulations underline the impact of the successive position of the Ni/Te honeycomb layers and validate the presence of multiple stacking sequences within the powder material, in proportions that evolve with the synthesis conditions. In a broader context, this work contributes to a better understanding of the alkali-mixed layered compounds.

Alkali-Glass Behavior in Honeycomb-Type Layered Li3-xNaxNi2SbO6 Solid Solution.

Layered oxide compositions Li3-xNaxNi2SbO6 have been prepared by solid-state synthesis. A complete solid solution is evidenced and characterized by X-ray and neutron diffraction as well as 7Li and 23Na solid-state nuclear magnetic resonance spectroscopy. The transition-metal layer is characterized by the classic honeycomb Ni2+/Sb5+ ordering, whereas a more uncommon randomly mixed occupancy of lithium and sodium is evidenced within the alkali interslab space. In situ X-ray diffraction and density functional theory calculations show that this alkali disordered feature is entropically driven. Fast cooling then appears as a synthesis root to confine bidimensional alkali glass within crystalline layered oxides.

Correlations between physical and ultrasound findings in congenital clubfoot at birth.

BACKGROUND: At birth, clinical classifications are the only available tools for evaluating the severity of congenital clubfoot. Ultrasound provides an assessment of the anatomical abnormalities. The objective of this study was to assess correlations between physical and ultrasound findings at birth. HYPOTHESIS: Physical and ultrasonography provide different findings in congenital clubfoot and should therefore be used in conjunction. MATERIAL AND METHOD: One hundred and forty-five clubfeet in 108 patients born between 2006 and 2010 were included in a retrospective study. Clubfoot severity was classified using two methods, the modified Dimeglio classification based on physical findings and an ultrasound score based on the talo-navicular angle (TNA) and metaphyso-talo-calcaneal angle (MTCA). Each of these two methods distinguished three severity grades. Agreement between the two methods was assessed by computing the coefficient. RESULTS: The results confirmed the hypothesis by showing low agreement between the clinical and ultrasound classifications. The severity grades were identical with the two methods for only 83/145 (57%) feet. The coefficient was 0.086. DISCUSSION: The two ultrasound views used to measure the TNA and MTCA, respectively, added an assessment of the three main deformities that characterise congenital clubfoot (equinus, adduction of the forefoot, and adduction of the calcaneo-pedal unit). Ultrasonography complements the physical examination at birth. In the future, using both physical examination and ultrasound scanning to monitor babies with clubfoot may allow early treatment adjustments aimed at optimising the outcome. LEVEL OF EVIDENCE: IV, retrospective observational study.

Extensive Necrotic Skin Lesions Due to Post-varicella Protein S Deficiency.

Postvaricella protein S deficiency is a rare and severe disease. We report a case of extensive necrotic skin lesions of acute onset 7 days after varicella in a 4-year-old girl. Protein S antigen and activity were <10%, and antiprotein S antibodies were detected. She was treated with anticoagulation, plasmapheresis and fresh frozen plasma. She survived but required leg amputation.

The Quest for Polysulfides in Lithium-Sulfur Battery Electrolytes: An Operando Confocal Raman Spectroscopy Study.

Confocal Raman spectra of a lithium-sulfur battery electrolyte are recorded operando in a depth-of-discharge resolved manner for an electrochemical cell with a realistic electrolyte/sulfur loading ratio. The evolution of various possible polysulfides is unambiguously identified by combining Raman spectroscopy data with DFT simulations.

Better cycling performances of bulk Sb in Na-ion batteries compared to Li-ion systems: an unexpected electrochemical mechanism.

Pure micrometric antimony can be successfully used as negative electrode material in Na-ion batteries, sustaining a capacity close to 600 mAh g(-1) at a high rate with a Coulombic efficiency of 99 over 160 cycles, an extremely high capacity compared to any other compound tested against both Li and Na. The reaction mechanism with Na does not simply go through the alloying mechanism observed for Li where the intermediate species are those expected from the phase diagram. In the case of Na, the intermediate phases are mostly amorphous and could not be precisely identified. Surprisingly, we evidenced that a competition takes place at the end of the discharge of the Sb/Na cell between the formation of the hexagonal and the cubic polymorphs of Na(3)Sb, the last being described in the literature as unstable at atmospheric pressure and only synthesized under high pressure (1-9 GPa). In addition, fluoroethylene carbonate added to the electrolyte combined with an appropriate electrode formulation based on carboxymethyl cellulose, carbon black, and vapor ground carbon fibers seems to be determinant in the excellent performances of this material.

Physico-chemical characterization of γ-amino n-butyric acid nanoparticles.

This work deals with the preparation and characterization of high-purity nanoparticles of γ-amino n-butyric acid (GABA) in order to enhance the efficiency of this drug. A sublimation procedure at low pressure was applied to GABA after improving the experimental parameters of this physical transformation. The elaboration of the molecule is solvent-free. The process does not change the chemical formula of the compound but modifies its physico-chemical characteristics. In this work, we present the experimental parameters for preparing monoclinic GABA nanoparticles. Their identification and physico-chemical properties were determined with a large number of investigations: Powder X-ray diffraction (PXRD), density and purity measurements, differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA), calorimetric measurements (ΔH(dissolution) and C(p)), thermally stimulated current (TSC), and electrochemical impedance.

Structural in situ study of the thermal behavior of manganese dioxide materials: toward selected electrode materials for supercapacitors.

The thermal behavior of a series of MnO2 materials was investigated toward MnO2 microstructures under inert atmospheres. The byproduct formed during MnO2 heat treatments from the room temperature to 800 °C were characterized by in situ X-ray diffraction analyses. It was found that annealing spinel and ramsdellite phases caused the formation of MnO2 pyrolusite at 200 °C, Mn2O3, at 400 °C, and then Mn3O4 at higher temperatures. In the case of cryptomelane and birnessite phases, the heating process resulted in the formation of K0.51Mn0.93O2 at 600 °C, while Mn3O4 was also formed and still present up to 800 °C. Heat-treating Ni-todorokite and OMS-5 up to about 450 °C led to the formation of NiMn2O4 and NaxMnO2, respectively, and again Mn3O4 at higher temperatures. All of these structural transformations were correlated to resulting weight losses of MnO2 powders, measured by thermogravimetric analyses, during the heating process. Cyclic voltammetry measurements were performed in the presence of 0.5 M K2SO4 aqueous solution for annealed cryptomelane, K0.51Mn0.93O2, and Mn3O4-based electrodes. It was found that MnO2 cryptomelane is electrochemically stable upon heating. The long-term charge/discharge voltammetric cycling revealed that the specific capacitance of Mn3O4-based electrode is significantly improved from 14 F·g(-1) (after 20 cycles) to 123 F·g(-1) (after 500 cycles).

Experimental electron density study of tetrakis-mu-(acetylsalicylate)dicopper(II): a polymeric structure with Cu...Cu short contacts.

The electron density, its topological features, and the electrostatic potential of tetrakis-mu-(acetylsalicylate)dicopper(II), Cu[C(9)H(7)O(4)](2), have been derived from an accurate high-resolution diffraction experiment at 100 K. This complex exhibits a polymeric structure involving one acetyl oxygen atom as a bridge in the solid state. Only van der Waals interactions between the polymeric chains are observed. The copper cation is octahedrally coordinated with five oxygen atoms of the aspirinate ligands and one adjacent Cu with short Cu...Cu contact distances in the range of 2.6054(1) A. The Cu-O bond lengths are equal to 1.96 A except the apical one which is 2.2183(7) A. The multipole refinements were carried out using the Hansen-Coppens model coded in the MOPRO computer program. Starting from the 3d(10)4s(1) copper electron configuration, the electron density analysis and Cu d-orbital populations reveal that the observed configuration is close to being [Ar]3d(9)4s(1). As expected from the ligand field theory, the most depopulated 3d-orbital is the d(x(2)-y(2)) (1.17 e) one with lobes pointing toward the carboxylic oxygen atoms. Conversely, the d(z(2)) is the most populated orbital for a z-axis directed along the Cu...Cu bond. The atomic charges were derived from a kappa-refinement and yielded a metal net charge of +1.20(3) e. Deficits of +0.72(6) and +0.59(7) e are obtained for the acetyl carbon atoms of the aspirinate ligands, those involved in the drug activity of aspirin. Comparisons are made to the results of our previous work on the zinc-aspirinate complex.

Childhood delayed septic arthritis of the knee caused by Serratia fonticola.

We report a first documented case of Serratia fonticola infection in a child with septic arthritis, after falling off his bicycle and an infection with hawthorn thorns. The aetiologic agent was found to be a S. fonticola strain which was first isolated from two synovial fluid samples, only after culture enrichment, with failure of DNA amplification. Accurate diagnostic was done, despite S. fonticola is often considered as an opportunistic pathogenic bacterium. Alone ciprofloxacin treatment was not sufficient to counteract the infection, which was eradicated only after surgical drainage performed twice successively, with secondary removal of a remaining thorn, and treatment with third generation cephalosporin combined with ciprofloxacin for another three months.

Topological features of both electron density and electrostatic potential in the bis(thiosemicarbazide)zinc(II) dinitrate complex.

The experimental electron density of the bis(thiosemicarbazide)zinc(II) dinitrate complex, [Zn(CH5N3S)2](NO3)2,was studied. The Hansen-Coppens multipole model was used to extract the electron density from high-resolution X-ray diffraction data collected at 100 K. Careful strategies were designed for the electron density refinements regarding the charge transfer between the anionic and the cationic parts of the complex. Particular attention was also paid to the treatment of the electron density of the zinc atom interacting with two thiosemicarbazide ligands in a tetrahedral coordination. Nevertheless, the filled 3d valence shell of Zn was found unperturbed, and only the 4s shell was engaged in the metal-ligand interaction. Topological properties of both electron density and electrostatic potential, including kinetic and potential energy densities, and atomic charges were reported to quantify a metal-ligand complex with particular Zn-S and Zn-N bonds and hydrogen-bonding features. Chemical activities were screened through the molecular surface on which the three-dimensional electrostatic potential function was projected. The experimental results were compared to those obtained from gas-phase quantum calculations, and a good agreement was reached between these two approaches. Finally, among other electrostatic potential critical points, the values at the maxima corresponding to the nuclear sites were used as indices of the hydrogen-bonding capacity of the thiosemicarbazide ligand.

Cervical spine stenosis in chondrodysplasia punctata.

Chondrodysplasia punctata (CDP) is a rare skeletal dysplasia characterized by stippled epiphyses during infancy. The frequency is probably underdiagnosed because of the large heterogeneity in this group. Many genotypic variations exist. Although cervical instability is commonly seen in many skeletal dysplasias, cervical spine stenosis associated with CDP is very rare. We report a boy with phenotypic features of brachytelephalangic chondrodysplasia punctata (BCDP) who had severe cervical spine stenosis successfully corrected by vertebrectomies of C6 and C7 with a fibular strut graft. We discuss the significance of this association.

Electronic properties of 3,3'-dimethyl-5,5'-bis(1,2,4-triazine): towards design of supramolecular arrangements of N-heterocyclic Cu(I) complexes.

A new efficient and safe synthesis of 3,3'-dimethyl-5,5'-bis-(1,2,4-triazine) is presented. The electron-density distribution and electrostatic properties (charge, electrostatic potential) of this molecule were analyzed. These properties were derived from a high-resolution single-crystal X-ray diffraction experiment at 100 K and compared to the results obtained from ab initio DFT quantum-mechanical calculations. Comparisons of its electrostatic potential features and integrated atomic charges (quantum theory of atoms in molecules, QTAIM) have been made with those of related molecules such as bipyrimidine ligands. Two methods were used to derive integrated charges: one is based on the conventional analytical procedure and the second uses a steepest-ascent numerical algorithm. Excellent agreement was obtained between these two methods. Charges and electrostatic potential were used as predictive indices of metal chelation and discussed in the light of complexation abilities of the title compound and related molecules. The crystal structure of a Cu(I) complex of 3,3'-dimethyl-5,5'-bis(1,2,4-triazine) is reported here. In the solid state, this complex forms a three-dimensional multibranch network with open channels in which counterions and solvent molecules are located. This architecture involves both cis and trans isomers of the title compound.

Experimental/theoretical electrostatic properties of a styrylquinoline-type HIV-1 integrase inhibitor and its progenitors.

We have established that polyhydroxylated styrylquinolines are potent inhibitors of HIV-1 integrase (IN). Among them, we have identified (E)-8-hydroxy-2-[2-(4,5-dihydroxy-3-methoxyphenyl)-ethenyl]-7-quinolinecarboxylic acid (1) as a promising lead. Previous molecular dynamics simulations and docking procedures have shown that the inhibitory activity involves one or two metal cations (Mg2+), which are present in the vicinity of the active center of the enzyme. However, such methods are generally based on a force-field approach and still remain not as reliable as ab initio calculations with extended basis sets on the whole system. To go further in this area, the aim of the present study was to evaluate the predictive ability of the electron density and electrostatic properties in the structure-activity relationships of this class of HIV-1 antiviral drugs. The electron properties of the two chemical progenitors of 1 were derived from both high-resolution X-ray diffraction experiments and ab initio calculations. The twinning phenomenon and solvent disorder were observed during the crystal structure determination of 1. Molecule 1 exhibits a planar s-trans conformation, and a zwitterionic form in the crystalline state is obtained. This geometry was used for ab initio calculations, which were performed to characterize the electronic properties of 1. The electron densities, electrostatic potentials, and atomic charges of 1 and its progenitors are here compared and analyzed. The experimental and theoretical deformation density bond peaks are very comparable for the two progenitors. However, the experimental electrostatic potential is strongly affected by the crystal field and cannot straightforwardly be used as a predictive index. The weak difference in the theoretical electron densities between 1 and its progenitors reveals that each component of 1 conserves its intrinsic properties, an assumption reinforced by a 13C NMR study. This is also shown through an excellent correlation of the atomic charges for the common fragments. The electrostatic potential minima in zwitterionic and nonzwitterionic forms of 1 are discussed in relation with the localization of possible metal chelation sites.