Achilles Tendon and Athletes

Achilles tendon (AT) is the strongest human tendon. AT disorders are common among athletes. AT pathologies vary from tendinopathy to frank rupture. Diagnosis is made clinically. Imaging modalities are used adjunctively. Management of AT rupture in athletes is challenging to surgeons due to worldwide growing popularity of sports and potential social and financial impact of AT injury to an athlete. Hence, new surgical techniques aim at attaining quick recovery with good outcome, finding similar results with both open and percutaneous techniques when accompanying these with functional rehabilitation protocols. Non-operative strategies include shoe wear modification, physiotherapy and extracorporeal shock wave therapy. Surgical interventions vary based on the AT pathology nature and extent. Direct repair can work for small-sized defects. V-Y gastrocnemius advancement could approximate the tendon edges for repair within 2–8 cm original gap. Gastrocnemius turndown can bridge tendon loss > 8 cm. Autogenous, allogeneous or synthetic tendon grafts were used for AT reconstruction purposes. In AT tendinopathies with no tendon tissue loss, surgical procedures revolve around induction of tissue repair through lesion incision or debridement to full detachment followed by reattachment. Extra-precautions are exercised for prevention of AT disorders especially among susceptible athletes participating in sports involving excessive AT strain

ADSORPTION OF COPPER AND ZINC ON HALLOYSITE NANOTUBES MODIFIED BY POLYETHYLENE IMINE: KINETIC AND THERMODYNAMIC STUDIES

This work was supported by the Program 211 of the Government of the Russian Federation, RFBR grants 17-03-00641 and 18-29- 12129mk, the State Task from the Ministry of the Education and Science of the Russian Federation

Patient-specific Instrumentation Versus Standard Surgical Instruments in Primary Reverse Total Shoulder Arthroplasty: A Retrospective Comparative Clinical Study.

AimsPatient-specific instrumentation (PSI) in primary shoulder arthroplasty has been studied; results supported the positive impact of the PSI on the glenoid positioning. Nevertheless, no clinical outcomes have been reported. We compare the clinical outcomes of primary reverse total shoulder arthroplasty using PSI versus the standard methods.MethodsFifty-three patients with full records and a minimum of 24-months follow-up were reviewed, 35 patients received primary standard RSTA, and 18 patients received primary PSI RSTA. All patients were operated on in a single center. The median follow-up was 46 months (53 months in the standard group vs 39 months in the PSI group).ResultsThere was an overall significant post-operative improvement in the whole cohort (PConclusionIn this series, both groups achieved comparable good outcomes. PSI did not achieve significantly better clinical outcomes than Standard after primary RSTA. Yet comparison has some limitations. PSI did not negatively impact the waiting time or the surgical time

АНАЛИЗ СИСТЕМЫ Nb-Al И СИНТЕЗ ОДНОГО ИЗ ИНТЕРМЕТАЛЛИДОВ

Работа выполнена в рамках гранта РНФ (проект № 22-23-00322)

Chemical modifications of chitosan nano-based magnetic particles for enhanced uranyl sorption

International audienceThe grafting of diethylenetriamine (preferentially to the grafting of serine > cysteine > alanine) onto chitosan (immobilized on magnetic nano-based particles by combined polymer precipitation and hydrothermal treatment) allows synthesizing an efficient sorbent for uranyl at pH 4 (maximum sorption capacity close to 185 mg U g(-1)). Sorption isotherm (regardless of the sorbent) is fitted by the Langmuir equation, while uptake kinetics is well described by the pseudo-second order rate equation. The design of nano-based particles (10-50 nm) allows reducing the impact of resistance to intraparticle diffusion on uptake kinetics and the equilibrium contact time is close to 45-60 min. The super paramagnetic properties of the hybrid materials make their solid/liquid separation quite easy using an external magnetic field. Finally uranyl ions can be desorbed using acidic urea solution (0.5 M, pH >2) and the sorbents can be recycled for at least 5/6 cycles with a limited loss of sorption capacity (<9%)

Aspartic acid grafting on cellulose and chitosan for enhanced Nd(III) sorption

International audienceCellulose and chitosan have intrinsic sorption properties for Nd(III); however, their efficiency for metal recovery can be easily improved by a relatively simple chemical modification. The grating of aspartic acid via an intermediary chlorination step of the polysaccharides allows increasing sorption capacities due to the specific reactivity of carboxylate groups. The grafting process is confirmed by elemental analysis, FTIR spectrometry, while the physical properties of the derivatives are characterized by XRD (crystallinity) and TGA (thermogravimetric analysis). The sorption properties are carried out by investigating the effect of the pH, studying the uptake kinetics and evaluating the thermodynamics (sorption isotherms). The sorption properties of modified sorbents are systematically compared to the performance of raw materials. Sorption capacity is doubled after grafting aspartic acid onto biopolymer backbone. Sorption isotherms are described by the Freundlich and the Langmuir equation and maximum sorption capacities reach up to 77-80 mg Nd g(-1) at pH 5. The uptake kinetics are described by the pseudo-first order reaction rate and under selected experimental conditions the equilibrium is reached within 3 h of contact. The sorption is spontaneous, endothermic. Metal desorption can be successfully performed with 0.5 M nitric acid and the sorbents can be recycled for at least 4 sorption/desorption cycles without significant loss in sorption/desorption performances

Mesoporous Magnetic Cysteine Functionalized Chitosan Nanocomposite for Selective Uranyl Ions Sorption: Experimental, Structural Characterization, and Mechanistic Studies

Nuclear power facilities are being expanded to satisfy expanding worldwide energy demand. Thus, uranium recovery from secondary resources has become a hot topic in terms of environmental protection and nuclear fuel conservation. Herein, a mesoporous biosorbent of a hybrid magnetic&ndash;chitosan nanocomposite functionalized with cysteine (Cys) was synthesized via subsequent heterogeneous nucleation for selectively enhanced uranyl ion (UO22+) sorption. Various analytical tools were used to confirm the mesoporous nanocomposite structural characteristics and confirm the synthetic route. The characteristics of the synthesized nanocomposite were as follows: superparamagnetic with saturation magnetization (MS: 25.81 emu/g), a specific surface area (SBET: 42.56 m2/g) with a unipore mesoporous structure, an amine content of ~2.43 mmol N/g, and a density of ~17.19/nm2. The experimental results showed that the sorption was highly efficient: for the isotherm fitted by the Langmuir equation, the maximum capacity was about 0.575 mmol U/g at pH range 3.5&ndash;5.0, and Temperature (25 &plusmn; 1 &deg;C); further, there was excellent selectivity for UO22+, likely due to the chemical valent difference. The sorption process was fast (~50 min), simulated with the pseudo-second-order equation, and the sorption half-time (t1/2) was 3.86 min. The sophisticated spectroscopic studies (FTIR and XPS) revealed that the sorption mechanism was linked to complexation and ion exchange by interaction with S/N/O multiple functional groups. The sorption was exothermic, spontaneous, and governed by entropy change. Desorption and regeneration were carried out using an acidified urea solution (0.25 M) that was recycled for a minimum of six cycles, resulting in a sorption and desorption efficiency of over 91%. The as-synthesized nanocomposite&rsquo;s high stability, durability, and chemical resistivity were confirmed over multiple cycles using FTIR and leachability. Finally, the sorbent was efficiently tested for selective uranium sorption from multicomponent acidic simulated nuclear solution. Owing to such excellent performance, the Cys nanocomposite is greatly promising in the uranium recovery field

Grafting of arginine and glutamic acid onto cellulose for enhanced uranyl sorption

International audienceThe grafting of arginine and glutamic acid on cellulose (through an intermediary step of chlorination) allows improving uranyl sorption of the biopolymer. The sorbents (Arg-Cell and Glu-Cell) were characterized by elemental analysis, FTIR spectrometry, XRD, SEM-EDX analysis and TGA. The sorption efficiency increases with pH; this can be attributed to the deprotonation of carboxylic acid and amine groups and to the formation of polynuclear hydrolyzed uranyl species. Sorption isotherms (fitted by the Langmuir equation) show sorption capacities at saturation of the monolayer of 147 and 168 mg U g(-1) for Arg-Cell and Glu-Cell, respectively (compared to 78 mg U g(-1) for raw cellulose); maximum sorption capacities at equilibrium (experimental values) reach 138, 160 and 73.4 for Arg-Cell, Glu-Cell and cellulose, respectively. Uranyl sorption is endothermic and is spontaneous for amino acid derivatives of cellulose (contrary to exothermic for cellulose). Uptake kinetics for the different sorbents are fitted by the pseudo-second-order rate equation. Uranium can be desorbed using sulfuric acid solutions, and the sorbents can be recycled for a minimum of five cycles of sorption/desorption: the decrease in sorption capacities at the fifth cycle does not exceed 13%

Cu(II) and Zn(II) metal ions’ sorption utilising halloysite nanotubes derivative

Designing and developing clay-based adsorbents with a strong preference for removing copper and zinc metal ions, reduced cost, eco-friendliness, and good recyclability is a good strategy for water remediation. Herein, halloysite nanotubes (HNT) were activated by (3- chloropropyl) trimethoxy silane (CPTM) as a linker for polyethyleneimine to give HN-PEI. The hybrid organic/inorganic sorbent HN-PEI was analysed by Fourier-transform infrared spectroscopy, CHN/O (elemental analysis), scanning electron microscopy, textural properties (via the Brunauer – Emmett – Teller technique), X-ray diffraction, and thermogravimetry coupled with differential scanning calorimetry. The HN-PEI’s textural properties show a reduced specific surface of 10.92 m2/g and pore size of 18.2 nm compared to its Pristine HNT (65.33 m2/g) and pore size (⁓10.1 nm), respectively with a dominant mesoporous structure. The selectivity and sorption characteristics of the Cu(II) and Zn(II) metal ions were exploited, while HN-PEI exhibited a remarkable improvement in terms of removing these ions from the aqueous media. At pH 4.5, the sorption capacities for Cu(II) were 2.8 mmol g−1 and for Zn(II) were 1.8 mmol g−1, with equilibrium reached within 120 and 150 min, respectively. There was an acceptable fitting of the pseudo-second-order and Langmuir equations, and the experimental data enabled mono-layer chemisorption reactions. The sorption was exothermic and spontaneous. The sorbent HN-PEI shows high durability over multiple cycles, and after 3 cycles, the sorption/desorption efficacy decreased by less than 6% using HCl (1 M) for Cu(II) and H2SO4 (1.5 M) for Zn(II). According to the bi-system solution sorption test, KSC(Cu(II)/Zn(II)) was ⁓2.0. Finally, HN-PEI had excellent selectivity and efficiency for Cu(II), Pb(II), and Zn(II) ions, especially for Cu(II).</p

Synthesis of polyaminophosphonic acid-functionalized poly(glycidyl methacrylate) for the efficient sorption of La(III) and Y(III)

International audienceAfter synthesis of parent PGMA micro-particles by dispersion polymerization method, diethylenetriamine (DETA) is grafted on the polymer (DETA-PGMA). In the last step, methylene phosphonic groups are grafted on DETA-PGMA by reaction of phosphonic acid groups onto amine functions in the presence of formaldehyde to produce polyaminophosphonic acid sorbent (PPA-PGMA). The sorbent is characterized by elemental analysis, FTIR spectrometry, XPS, XRD, TG-TDA and SEM-EDX analyses. The sorption properties of the material are tested for the sorption of La(III) and Y(III): the effect of pH on sorption performance is investigated before studying uptake kinetics, sorption isotherms (and thermodynamics), metal desorption and sorbent recycling. Maximum sorption capacities reach up to 0.79 mmol La g(-1) and 0.73 mmol Y g(-1) at pH 5 (optimum initial pH value). Sorption isotherms are characterized by a saturation plateau: the Langmuir equation fits well data. The sorption on micron-sized particles is fast and equilibrium is reached within 3-4 h: the kinetic profiles are modelled by the Crank equation (resistance to intraparticle diffusion) though the pseudo-first order rate equation fits well experimental data. Nitric acid (0.5 M) solutions can be used for metal recovery and the sorbent is re-used for at least 6 cycles of sorption and desorption with limited decrease in performance (less than 7%). The sorbent has a preference at pH 5 for La(III) vs. Y(III) but the selectivity coefficient is not high enough for potentiating the selective separation of the two metals