Orthoplastic limb reconstruction using free fibula flap after trauma: Outcomes from a retrospective European multicenter study.

BACKGROUND: Free vascularized fibula flap represents the gold standard vascularized bone graft for the management of segmental long bone defects after traumatic injury. The current study represents the largest retrospective multicenter data collection on the use of free fibula flap (FFF) for extremities' orthoplastic reconstruction after trauma aiming to highlight current surgical practice and to set the basis for updating current surgical indications. METHODS: The study is designed as a retrospective analysis of prospectively collected data between 2009 and 2021 from six European University hospitals. Patients who underwent fibula flap reconstruction after acute traumatic injury (AF) or as a late reconstruction (LF) after post-traumatic non-union of upper or lower limb were included. Only extra-articular, diaphyseal fracture were included in the study. Surgical data were collected. Time to bone healing and complications were reported as clinical outcomes. RESULTS: Sixty-two patients were included in the study (27 in the AF group and 35 in the LF group). The average patients' age at the time of the traumatic event was 45.3 ± 2.9 years in the AF group and 41.1 ± 2.1 years in the LF group. Mean bone defect size was 7.7 ± 0.6 cm for upper limb and 11.2 ± 1.1 cm (p = .32) for lower limb. Bone healing was uneventful in 69% of treated patients, reaching 92% after complementary procedures. Bone healing time was 7.6 ± 1.2 months in the acute group and 9.6 ± 1.5 months in the late group. An overall complication rate of 30.6% was observed, with a higher percentage of late bone complications in the LF group (34%), mostly non-union cases. CONCLUSIONS: FFF reconstruction represents a reliable and definitive solution for long bone defects with bone healing reached in 92% cases with a 8.4 months of average bone healing time.

A Prato Tour on Carbon Nanotubes: Raman Insights.

The functionalisation of carbon nanotubes has been instrumental in broadening its application field, allowing especially its use in biological studies. Although numerous covalent and non-covalent functionalisation methods have been described, the characterisation of the final materials has always been an added challenge. Among the various techniques available, Raman spectroscopy is one of the most widely used to determine the covalent functionalisation of these species. However, Raman spectroscopy is not a quantitative technique, and no studies are reported comparing its performance when the same number of functional groups are added but using completely different reactions. In this work, we have experimentally and theoretically studied the functionalisation of carbon nanotubes using two of the most commonly used reactions: 1,3-dipolar cycloaddition of azomethylene ylides and diazonium-based radical addition. The number of groups introduced onto the tubes by these reactions has been determined by different characterisation techniques. The results of this study support the idea that data obtained by Raman spectra are only helpful for comparing functionalisations produced using the same type of reaction. However, they should be carefully analysed when comparing functionalisations produced using different reaction types.

Highly Functionalized SWCNTs with a Dopamine Derivative as a Support for Pd Nanoparticles: A Recyclable Catalyst for the Reduction of Nitro Compounds and the Heck Reaction.

Single-walled carbon nanotubes (SWCNTs) were functionalized with a dopamine derivative in which the amine group was converted to azide (dopamine azide). The direct reaction of SWCNTs and dopamine azide in o-dichlorobenzene at high temperature (160 °C) led to very highly functionalized CNTs (≈60 wt.%). Surprisingly, despite this high degree of functionalization, Raman spectroscopy detected a low disruption of the π-network of the carbonaceous support. This finding was justified by the rehybridization from sp3 to sp2 of the sidewall carbon atoms of CNTs involved in the functionalization process. Further characterization by means of different techniques such as X-ray photoelectron spectroscopy (XPS) analysis and transmission electron microscopy (TEM) allowed to shed some light on the chemical composition and morphology of the obtained material. Moreover, the estimation of the total content of phenolic units and their reducing potential after CNTs functionalization was also assessed using Folin and Ciocalteu and 2,2-diphenyl-1-picryl hydrazide (DPPH) assays. The functionalization of CNTs was exploited to immobilize palladium(II) species that were subsequently reduced with NaBH4 leading to the formation of Pd nanoparticles (NPs). The so obtained hybrid material was used as a recyclable heterogeneous catalyst for the reduction of nitro compounds and the Heck reaction.

Supported Poly(Ionic Liquid)-Heteropolyacid Based Materials for Heterogeneous Catalytic Fructose Dehydration in Aqueous Medium.

Two sets of four different supported catalyst materials were prepared. One set was obtained by polymerization of a bis-vinylimidazolium salt, which formed a poly(ionic liquid) coating on SiO2, TiO2, boron nitride BN, and carbon nitride C3N4. The other set was, instead, obtained by immobilizing Keggin heteropolyacid H3PW12O40 onto poly-imidazolium functionalized materials. All the catalysts, including the bare supports, were subjected to physical and chemical characterization by XRD, SEM, Specific Surface Area and pore size measurements, TGA, FTIR, and acidity-basicity measurements. The catalytic activity of the materials was tested versus the fructose dehydration in water solution at two different sugar initial concentrations (0.3 and 1 M). Tests lasted 3 h with an amount of catalyst of 2 g∙L−1. The presence of the poly-imidazolium on the surface of the supports increased the catalytic conversion of fructose to 5-hydroxymethylfurfural (the most abundant compound obtained) and was further improved by the contemporary presence of the heteropolyacid, at least for the highest initial fructose concentration. In the latter conditions, the highest yield of 5-hydroxymethylfurfural (>40%) was also obtained.

First Evidence of Tris(catecholato)silicate Formation from Hydrolysis of an Alkyl Bis(catecholato)silicate.

The hydrolysis of 3-ammoniumpropylbis(catecholato)silicate 1, giving two different silica-based materials containing different amounts of tris(catecholato)silicate, is reported. The latter species can be formed through an attack of catechol to the silicon atom in the pentacoordinate complex, in which the silicon-carbon bond is further activated toward electrophilic proton cleavage. The Knoevenagel reaction was used as a probe in order to test the availability of functional groups on the surface of such materials.

Prosthetic Replacement of the Scaphoid Proximal Pole: Should It Be the Future?

BACKGROUND: Scaphoid proximal pole fractures with avascular necrosis represent a complex surgical problem. Many reconstruction techniques are based on osteosynthesis with a vascularized or nonvascularized bone graft. These procedures do not allow early mobilization and therefore sometimes lead to unsatisfying functional results. In some cases, it is possible to perform a scaphoid hemiarthroplasty using a pyrocarbon implant (adaptive proximal scaphoid implant [APSI]) in place of the necrotic proximal pole, allowing an early mobilization and delaying palliative treatments such as 4-corner arthrodesis or proximal row carpectomy. METHODS: In this study, we reviewed all patients who had undergone a scaphoid hemiarthroplasty using APSI in our institutions from 1999 to 2017; the F.U. was performed through radiographic, clinical, and subjective (Disabilities of the Arm, Shoulder, and Hand) analysis. RESULTS: The performances of scaphoid proximal pole implants are encouraging; radiographic, clinical, and subjective outcomes were good, and the functional recovery proved to be fast and reliable over time. CONCLUSIONS: This study reports our experience in the use of APSI implants, which proved to be a good alternative to traditional techniques for treating avascular necrosis of the proximal pole, still allowing further surgical steps in case of clinical worsening over time (wrist osteoarthritis). These patients are usually young and present high functional demands. Our experience is promising, but we believe that further evaluation over time will be needed.

A Study on the Stability of Carbon Nanoforms-Polyimidazolium Network Hybrids in the Conversion of CO2 into Cyclic Carbonates: Increase in Catalytic Activity after Reuse.

Three different carbon nanoforms (CNFs), single-walled and multi-walled carbon nanotubes (SWCNTs, MWCNTs) and carbon nanohorns (CNHs), have been used as supports for the direct polymerization of variable amounts of a bis-vinylimidazolium salt. Transmission electron microscopy confirmed that all CNFs act as templates on the growth of the polymeric network, which perfectly covers the nanocarbons forming a cylindrical (SWCNTs, MWCNTs) or spherical (CNHs) coating. The stability of these hybrid materials was investigated in the conversion of CO2 into cyclic carbonate under high temperature and CO2 pressure. Compared with the homopolymerized monomer, nanotube-based materials display an improved catalytic activity. Beside the low catalytic loading (0.05-0.09 mol%) and the absence of Lewis acid co-catalysts, all the materials showed high TON values (up to 1154 for epichlorohydrin with SW-1:2). Interestingly, despite the loss of part of the polymeric coating for crumbling or peeling, the activity increases upon recycling of the materials, and this behaviour was ascribed to their change in morphology, which led to materials with higher surface areas and with more accessible catalytic sites. Transmission electron microscopy analysis, along with different experiments, have been carried out in order to elucidate these findings.

Bending Sensors Based on Thin Films of Semitransparent Bithiophene-Fulleropyrrolidine Bisadducts.

A novel bithiophene-fulleropyrrolidine bisadducts system (bis-Th2PC60 ) was synthesized and electropolymerized by chronoamperometry onto flexible ITO/PET substrates. The resulting semitransparent thin film was characterized by XPS, FT-IR, cyclic voltammetry and optical techniques, confirming the good outcome of the electropolymerization process. AFM investigations permitted to highlight an inherent disordered granular morphology, in which the grain-to-grain separation depends upon the application of bending. The electrical resistance of the thin film was characterized as a function of bending (in the range 0°-90°), showing promising responsivity to low bending angles (10°-30°). The ΔR/R0 variations turn out to be 8 %,16 % and 20 % for bending angles equal to 10°, 20° and 30°, respectively. This study represents a first step towards the understanding of piezoresistive properties in electropolymerized fullerenes-based thin films, opening up applications as bending sensor.

Salvage of advanced carpal collapse: proximal row carpectomy with pyrocarbon resurfacing of the capitate versus four-corner arthrodesis.

In this retrospective study we report on two comparable groups of patients with advanced carpal arthritis treated with either proximal row carpectomy combined with a pyrocarbon resurfacing of the capitate (31 patients) or a four-corner arthrodesis and dorsal plating (26 patients). Follow-up time was 46 months (24-118). Except for a modestly higher radial wrist deviation in the patients treated with four-corner arthrodesis, there were no significant differences in outcomes between the groups. Asymptomatic progression of osteoarthritis in the lunate fossa was observed in four cases in both groups. Two cases were converted to a total wrist arthrodesis in the pyrocarbon group compared with one case in the four-corner arthrodesis group. Although four-corner arthrodesis remains the reference standard in the treatment of wrist osteoarthritis with involvement of the midcarpal joint, proximal row carpectomy combined with pyrocarbon resurfacing of the capitate is an alternative option. It can even be used in selected cases with erosion of the lunate fossa.Level of evidence: III.

Tuneable Emission of Polyhedral Oligomeric Silsesquioxane Based Nanostructures that Self-Assemble in the Presence of Europium(III) Ions: Reversible trans-to-cis Isomerization.

Hybrid nanostructures with switchable and reversible "blue-red-green" emission were efficiently synthesized. These nanostructures comprise polyhedral oligomeric silsesquioxanes (POSS) that behave as a nanocage that can be functionalized with terpyridine-based organic ligands, which can be easily complexed with europium (III) ions. The complexes were characterized by UV-Vis and fluorescence spectroscopy and their stoichiometry was also confirmed by 1 H NMR spectroscopy. In the presence of the Eu(III) ions, the octafunctionalized nanocages self-assemble to form 3D architectures that display an intense red-emission, especially in the solid state. The presence of an alkenyl group bridging the inorganic core to the organic moiety was employed to tune the emission properties by trans-cis isomerization of the double bond. In the case of the octafunctionalized nanocages (O-POSS), this isomerization was monitored in the presence of Eu(III) cations and was accompanied by an evident colour change from blue (trans-O-POSS) to red (Eu@trans-O-POSS) and finally to green (cis-O-POSS) as consequence of the release of the metal cations. This behaviour, together with the easy dispersion of the dry powder and the possibility of coating as a film in presence of small amounts of solvent, makes the emissive solid promising for applications in materials science.

Straightforward preparation of highly loaded MWCNT-polyamine hybrids and their application in catalysis.

Multiwalled carbon nanotubes (MWCNTs) were easily and efficiently functionalised with highly cross-linked polyamines. The radical polymerisation of two bis-vinylimidazolium salts in the presence of pristine MWCNTs and azobisisobutyronitrile (AIBN) as a radical initiator led to the formation of materials with a high functionalisation degree. The subsequent treatment with sodium borohydride gave rise to the reduction of imidazolium moieties with the concomitant formation of secondary and tertiary amino groups. The obtained materials were characterised by thermogravimetric analysis (TGA), elemental analysis, solid state 13C-NMR, Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), potentiometric titration, and temperature programmed desorption of carbon dioxide (CO2-TPD). One of the prepared materials was tested as a heterogeneous base catalyst in C-C bond forming reactions such as the Knoevenagel condensation and Henry reaction. Furthermore, two examples concerning a sequential one-pot approach involving two consecutive reactions, namely Knoevenagel and Michael reactions, were reported.

The surgical outcomes of radial artery forearm free-flap phalloplasty in transgender men: single-centre experience and systematic review of the current literature.

Radial artery forearm free-flap (RAFFF) phalloplasty is considered by most authors as the gold-standard technique for genital gender-affirming surgery (GGAS). RAFFF surgical complications have rarely been investigated, and the aim of this study and literature review is to analyse and focus on the surgical technique and its postoperative vascular complications. From May 2016 to January 2020, a consecutive series of 25 transgender men who underwent GGAS were enrolled in the present study. Age, BMI and smoking habits were recorded for all patients. Overall, vascular flap complications occurred in 20% of cases. Complete flap loss due to acute arterial thrombosis was recorded in a single case (4%). In 8% of cases, limited ventro-proximal arterial ischaemia was detected, while in the remaining 8% of cases, venous ventral ischaemia was reported. These results were compared with the current literature results. Indeed, from our analysis, the number of flap veins (<2) was the only predictive factor for vascular complications. In conclusion, RAFFF represents a reliable option for total phallic construction, leading to satisfactory results in terms of flap survival. To optimize the surgical outcomes, venous vascular drainage should be recommended.

Efficient Conversion of Carbon Dioxide by Imidazolium-Based Cross-Linked Nanostructures Containing Polyhedral Oligomeric Silsesquioxane (POSS) Building Blocks.

Polyhedral oligomeric silsesquioxanes (POSS) have been employed as molecular building blocks for the synthesis of imidazolium cross-linked networks, to be used as heterogeneous catalysts for the conversion of carbon dioxide into cyclic carbonates. Two hybrid materials with different nucleophilic species (bromide and iodide) have been prepared and characterized by means of elemental analysis, 13 C and 29 Si solid-state NMR spectroscopy, thermogravimetric analysis and IR spectroscopy. The solids were tested as the sole catalyst under metal- and solvent-free reaction conditions showing full selectivity toward the formation of cyclic carbonates. High turnover number (TON) and productivity values, up to 5502 and 1081 respectively for glycidol conversion at 100 °C and up to 4942 and 1122 for epichlorohydrin conversion at 150 °C after 3 h, were obtained. Such outstanding productivity values were ascribed to the optimal organic/inorganic (i. e., imidazolium moiety/POSS support) weight ratio. The recyclability of the materials was successfully verified for five consecutive runs allowing their consideration as promising candidates for continuous flow technologies.

Resurfacing Capitate Pyrocarbon Implant versus Proximal Row Carpectomy Alone: A Comparative Study to Evaluate the Role of Capitate Prosthetic Resurfacing in Advanced Carpal Collapse.

BACKGROUND: The Resurfacing Capitate Pyrocarbon Implant associated with proximal row carpectomy has been used to treat symptomatic advanced carpal collapse, widening the indications of proximal row carpectomy to patients with capitate head arthritis. The authors retrospectively compared their case series of implant versus carpectomy alone, analyzing whether prosthetic implant outcomes could be similar to those of proximal row carpectomy even with a higher stage of osteoarthritis. METHODS: Fifty-seven patients who underwent surgery for wrist osteoarthritis (minimum follow-up, 2 years) were selected retrospectively. Twenty-five patients (scapholunate advanced collapse/scaphoid nonunion advanced collapse stage III to IV and Kienböck disease stage IV) underwent proximal row carpectomy plus Resurfacing Capitate Pyrocarbon Implant (group A); 32 patients (scapholunate advanced collapse/scaphoid nonunion advanced collapse stage I to II and Kienböck disease stage III) underwent carpectomy alone (group B). Mean follow-up was 33 months. Patients were evaluated clinically and radiographically. Patient-Rated Wrist Evaluation and Disabilities of the Arm, Shoulder, and Hand questionnaire scores were assessed. RESULTS: Group A showed consistent pain relief (visual analogue scale score of 2), while preserving wrist mobility (flexion, 27 degrees; extension, 33 degrees) and grip strength (54 percent compared with the contralateral side). Average Disabilities of the Arm, Shoulder, and Hand questionnaire score was 20, and average Patient-Rated Wrist Evaluation score was 28. No statistically significant difference was observed between groups for all outcomes, except for better extension (p < 0.05) in group B. CONCLUSIONS: Even starting from a higher grade of osteoarthritis, Resurfacing Capitate Pyrocarbon Implant plus proximal row carpectomy showed satisfying results, compared with those obtained with just carpectomy. Data show that indications for proximal row carpectomy can be widened by using the implant, without worsening outcomes. The implant could be a useful alternative to more aggressive salvage procedures in case of capitate head and lunate fossa osteoarthritis involvement. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Supported Ionic Liquids: A Versatile and Useful Class of Materials.

Supported ionic liquids (SILs) represent a class of materials with peculiar properties and a huge potential regarding their possible applications in different fields of chemistry. Herein, we report our ongoing research about the use of SILs as support for organocatalysts, their role as catalysts themselves, and their application as support and stabilizers of palladium nanoparticles (PdNPs). The use of SILs based materials allowed achieving good results. Moreover, in some cases, after the functionalization of the catalytic species with an ion-tag moiety, a release and catch approach was employed in order to improve the catalytic activity and to facilitate the recovery of the hybrid system formed by the catalyst adsorbed onto SILs materials. All the reported examples demonstrate the versatility of such SILs materials, which can represent powerful tools able to exert a large number of functions.

Imidazolium-Functionalized Carbon Nanohorns for the Conversion of Carbon Dioxide: Unprecedented Increase of Catalytic Activity after Recycling.

Six new hybrid materials composed of carbon nanohorns (CNHs) and highly cross-linked imidazolium salts were easily synthesized using a one-step procedure based on the radical oligomerization of bis-vinylimidazolium salts (bVImiX) in the presence of pristine CNHs. The hybrid materials were characterized and employed as the sole catalysts for the conversion of carbon dioxide into cyclic carbonate by reaction with epoxides. The solids displayed excellent turnover number and productivity. Moreover, four catalysts were investigated in recycling experiments. Two catalysts containing an octyl linker between the imidazolium units and a bromide or an iodide anion showed no loss in activity after three cycles. The other two catalysts containing a p-xylyl linker and a bromide anion and different CNHs/bVImiX ratios showed an unprecedented increase of activity after recycling.

Advances in Organic and Organic-Inorganic Hybrid Polymeric Supports for Catalytic Applications.

In this review, the most recent advances (2014-2016) on the synthesis of new polymer-supported catalysts are reported, focusing the attention on the synthetic strategies developed for their preparation. The polymer-supported catalysts examined will be organic-based polymers and organic-inorganic hybrids and will include, among others, polystyrenes, poly-ionic liquids, chiral ionic polymers, dendrimers, carbon nanotubes, as well as silica and halloysite-based catalysts. Selected examples will show the synthesis and application in the field of organocatalysis and metal-based catalysis both for non-asymmetric and asymmetric transformations.

Single-Walled Carbon Nanotube-Polyamidoamine Dendrimer Hybrids for Heterogeneous Catalysis.

We report the synthesis and catalytic properties of single-walled carbon nanotube-polyamidoamine dendrimers hybrids (SWCNT-PAMAM), prepared via a convergent strategy. The direct reaction of cystamine-based PAMAM dendrimers (generations 2.5 and 3.0) with pristine SWCNTs in refluxing toluene, followed by immobilization and reduction of [PdCl4](2-), led to the formation of highly dispersed small palladium nanoparticles homogeneously confined throughout the nanotube length. One of these functional materials proved to be an efficient catalyst in Suzuki and Heck reactions, able to promote the above processes down to 0.002 mol % showing a turnover number (TON) of 48 000 and a turnover frequency (TOF) of 566 000 h(-1). In addition, the hybrid material could be recovered and recycled for up to 6 times. No leaching of the metal has been detected during the Suzuki coupling. Additional experiments carried out on the spent catalyst permitted to suggest that a "release and catch" mechanism is operative in both reactions, although during Heck reaction small catalytically active soluble Pd species are also present.

Highly Loaded Multi-Walled Carbon Nanotubes Non-Covalently Modified with a Bis-Imidazolium Salt and their Use as Catalyst Supports.

The surfaces of multi-walled carbon nanotubes (MWCNTs) were non-covalently modified using two bis-imidazolium dibromide derivatives having phenyl or pyrene groups. Due to the presence of the two pyrene groups the bis(pyren-1-ylmethylimidazolium) dibromide derivative was immobilised at a loading of about 15-16 wt %, whereas only <3 wt % of the phenyl derivative was immobilised. The presence of the two imidazolium cations helped the immobilisation of tetrachloropalladate ions after exchange with bromide ions. Tetrachloropalladate was used as pre-catalyst in several Suzuki-Miyaura carbon-carbon cross-coupling reactions in water or water/ethanol at 50 °C in only 0.1 mol % and compared with the non-supported pre-catalyst. The MWCNT-supported material was used in five consecutive cycles of the Suzuki-Miyaura reaction. Recycling using phenylboronic acid and 4-bromobenzaldehyde in water/ethanol was achieved with only a minor loss in activity. HRTEM images clearly showed the presence of the bis(pyren-1-ylmethylimidazolium) derivative on the sidewalls of MWCNTs.

Fullerene-ionic-liquid conjugates: a new class of hybrid materials with unprecedented properties.

A modular approach has been followed for the synthesis of a series of fullerene-ionic-liquid (IL) hybrids in which the number of IL moieties (two or twelve), anion, and cation have been varied. The combination of C60 and IL give rise to new unique properties in the conjugates such as solubility in water, which was higher than 800 mg mL(-1) in several cases. In addition, one of the C60 -IL hybrids has been employed for the immobilization of palladium nanoparticles through ion exchange followed by reduction with sodium borohydride. Surprisingly, during the reduction several carbon nanostructures were formed that comprised nano-onions and nanocages with few-layer graphene sidewalls, which have been characterized by means of thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy/energy-dispersive X-ray analysis (SEM-EDAX), and high-resolution transmission electron microscopy (HRTEM). Finally, the material thus obtained was successfully applied as catalyst in Suzuki and Mizoroki-Heck reactions in a concentration of just 0.2 mol %. In the former process it was recyclable for five runs with no loss in activity.