Preparation and Electrochemical Properties of NiCo2 O4 Nanospinels Supported on Graphene Derivatives as Earth-Abundant Oxygen Bifunctional Catalysts.

This work reports on the facile synthesis and characterisation of a non-precious-metal bifunctional catalyst for oxygen reduction and evolution reactions (ORR and OER). A few-layer reduced graphene oxide-supported NiCo2 O4 catalyst is prepared using a rapid and easy two-step method of synthesis. It consists of the solvothermal poyl(vinylpyrrolidone)-assisted assembly of metal complexes onto few-layer graphene followed by a calcination step aiming at converting metal complexes into the spinel phase. Using this synthesis approach, the most active material demonstrates an outstanding activity towards the OER and ORR, making it one of the best bifunctional catalysts of these reactions ever reported. This composite catalyst exhibits improved bifunctional behaviour with a low reversibility criterion of 746 mV. The ORR process follows a four-electron pathway and the hydroxyl selectivity is higher than those with pure reduced graphene oxide or NiCo2 O4 materials, showing the synergistic effect between the two phases. Moreover, the high activity of this composite catalyst is confirmed by comparing its performance with those obtained on other cobaltite catalysts prepared using a different synthesis method, or those obtained using a different graphene-based support.

Palatal sclerotherapy for the treatment of intermittent dorsal displacement of the soft palate in 51 standardbred racehorses.

This retrospective study evaluated the efficacy and side effects of palatal sclerotherapy in standardbred racehorses suspected to have intermittent dorsal displacement of the soft palate (IDDSP). Fifty-one horses were treated with multiple endoscopically guided injections of 3% sodium tetradecyl sulfate in the soft palate. Two groups were identified: those that had respiratory noises during exercise (n = 27) and those that did not (n = 24). Treatment was well-tolerated. Furthermore, horses significantly reduced their racing times for the last 400 m compared with their times before treatment and even when their times were compared to the mean times for horses in the same race. In conclusion, palatal sclerotherapy appears to be a suitable alternative therapeutic option for horses suspected to have IDDSP.

Copper-enriched diamond-like carbon coatings promote regeneration at the bone-implant interface.

There have been several attempts to design innovative biomaterials as surface coatings to enhance the biological performance of biomedical implants. The objective of this study was to design multifunctional Cu/a-C:H thin coating depositing on the Ti-6Al-4V alloy (TC4) via magnetron sputtering in the presence of Ar and CH4 for applications in bone implants. Moreover, the impact of Cu amount and sp2/sp3 ratio on the interior stress, corrosion behavior, mechanical properties, and tribological performance and biocompatibility of the resulting biomaterial was discussed. X-ray photoelectron spectroscopy (XPS) revealed that the sp2/sp3 portion of the coating was enhanced for samples having higher Cu contents. The intensity of the interior stress of the Cu/a-C:H thin bio-films decreased by increase of Cu content as well as the sp2/sp3 ratio. By contrast, the values of Young's modulus, the H3/E2 ratio, and hardness exhibited no significant difference with enhancing Cu content and sp2/sp3 ratio. However, there was an optimum Cu content (36.8 wt.%) and sp2/sp3 ratio (4.7) that it is feasible to get Cu/a-C:H coating with higher hardness and tribological properties. Electrochemical impedance spectroscopy test results depicted significant improvement of Ti-6Al-4V alloy corrosion resistance by deposition of Cu/a-C:H thin coating at an optimum Ar/CH4 ratio. Furthermore, Cu/a-C:H thin coating with higher Cu contents showed better antibacterial properties and higher angiogenesis and osteogenesis activities. The coated samples inhibited the growth of bacteria as compared to the uncoated sample (p < 0.05). In addition, such coating composition can stimulate angiogenesis, osteogenesis and control host response, thereby increasing the success rate of implants. Moreover, Cu/a-C:H thin films encouraged development of blood vessels on the surface of titanium alloy when the density of grown blood vessels was increased with enhancing the Cu amount of the films. It is speculated that such coating can be a promising candidate for enhancing the osseointegration features.

Arthroscopic surgical approach and intra-articular anatomy of the equine suprapatellar pouch.

OBJECTIVE: To describe a direct arthroscopic approach to the suprapatellar pouch (SPP), its intra-articular anatomy, and report our clinical experience with SPP arthroscopy. STUDY DESIGN: (1) Experimental study and (2) retrospective clinical study. ANIMALS: (1) Cadaveric equine hind limbs (n=24; 14 horses) and (2) 5 horses. METHODS: Four femoropatellar joints (FPJ) were dissected or injected with latex to document surface landmarks and topographic anatomy. (1) Arthroscopic exploration of 20 SPP (10 equine cadavers) was performed and described, followed by dissection. (2) Medical records of horses that had FPJ arthroscopy were reviewed for cases where SPP portals were required. RESULTS: (1) The optimal arthroscopic portal was located approximately 10 cm lateral to the longitudinal patellar axis and 2 cm proximal to the patellar base in the intermuscular septum between the biceps femoris and vastus lateralis muscles. This approach allowed arthroscopic observation of the proximal aspect of the lateral and medial femoral trochlear ridges, the intertrochlear groove, the patellar base, and the synovial recess of the SPP. (2) Additional arthroscopic and instrument suprapatellar portals were used in 5 of 25 horses to complete lavage/debridement in osteochondritis dissecans (OCD) and septic arthritis. CONCLUSION: Suprapatellar arthroscopy improved arthroscopic observation of structures located proximally in the FPJ and facilitated surgical access to the SPP. CLINICAL RELEVANCE: SPP arthroscopy is a safe and complementary approach to traditional distal FPJ arthroscopy that could be helpful for inspection and removal of free fragments/debris/fibrin located in the SPP, for OCD lesions extending proximally, and fracture(s) involving the proximal aspect of the patella.

Palatal sclerotherapy: a potentially useful treatment of intermittent dorsal displacement of the soft palate in juvenile standardbred racehorses.

This study was aimed at evaluating the tolerability and the efficacy of palatal sclerotherapy in juvenile standardbred racehorses with easily audible "snoring-like" respiratory noises suspected to be the result of intermittent dorsal displacement of the soft palate. The palate of 8 horses was injected with sodium tetradecyl sulfate under videoendoscopic guidance. Palatal sclerotherapy resulted in resolution of the respiratory noise in 7 horses, improvement of performance in 6 horses, and mild side effects in only 3 horses. This preliminary study suggests that palatal sclerotherapy is a safe, repeatable, inexpensive, and promising technique that should be considered as an alternative to existing treatments of intermittent dorsal displacement of the soft palate.

Digestive enzyme concentrations and activities in healthy pancreatic tissue of horses.

OBJECTIVE: To measure concentrations and activities of major digestive enzymes in healthy equine pancreatic tissue. ANIMALS: 7 adult horses with normal pancreatic tissues. PROCEDURES: Small pieces of pancreatic tissue were collected immediately after euthanasia, immersed in liquid nitrogen, and maintained at -80 degrees C until analyzed. Concentrations and activities of amylase, lipase, chymotrypsin, trypsin, and elastase were determined by use of a microtiter technique. Relative pancreatic protein concentrations were determined by use of bovine serum albumin as the standard. Pancreatic DNA was extracted and con-centrations determined by use of the diphenylamine method with calf thymus DNA as the standard. RESULTS: The pancreatic cellular concentration of each enzyme, expressed as units per milligram of DNA, was consistent among horses. Cellular concentration of lipase (1,090.8 +/- 285.3 U/mg of DNA) was highest, followed by amylase (59.5 +/- 9.8 U/mg of DNA). Elastase, trypsin, and chymotrypsin were detected in small concentrations (1.9 +/- 0.6, 3.5 +/- 1.5, and 9.6 +/- 2.9 U/mg of DNA, respectively). Similar results were obtained for specific activities of the enzymes. CONCLUSIONS AND CLINICAL RELEVANCE: Results were unexpected because, under natural conditions, the predominant energy source for horses is carbohydrate. These results may indicate, in part, the reason horses seem to tolerate large amounts of fat added to their diet.

Effects of calcified cartilage on healing of chondral defects treated with microfracture in horses.

BACKGROUND: Microfracture of full-thickness articular defects has been shown to significantly enhance the amount of repair tissue. However, there is a suggestion that leaving calcified cartilage inhibits this repair response. HYPOTHESIS: Removal of the calcified cartilage with retention of subchondral bone enhances the amount of attachment of the repair tissue compared with retention of the calcified cartilage layer. STUDY DESIGN: Controlled laboratory study. METHODS: There were 1-cm(2) articular cartilage defects made in 12 skeletally mature horses on the axial weightbearing portion of both medial femoral condyles. Using a custom measuring device and direct arthroscopic observation of the subchondral bone beneath the calcified cartilage layer, the authors removed the calcified cartilage from 1 defect of each horse. The repair was assessed with arthroscopy, clinical examination, radiographic and magnetic resonance imaging examinations, biopsy at 4 months, gross and histopathologic examinations at 12 months, as well as mRNA and immunohistochemical evaluations. RESULTS: Removal of calcified cartilage with retention of the subchondral bone plate increased the overall repair tissue as assessed by arthroscopic (4 months) and gross evaluation (12 months). An increase in the level of the subchondral bone was also observed with removal of the calcified cartilage layer. The clinical pain, radiographic examinations, magnetic resonance imaging evaluations, histologic character, matrix proteins, or mRNA expression do not appear to differ based on level of defect debridement. CLINICAL RELEVANCE: Removal of the calcified cartilage layer appears to provide optimal amount and attachment of repair tissue. Therefore, close arthroscopic visualization is recommended for debridement of clinical lesions to ensure removal of the calcified cartilage layer.

Surgical management of a ureteral defect with ureterorrhaphy and of ureteritis with ureteroneocystostomy in a foal.

A 2-day-old male foal developed uroperitoneum. Initial exploration of the abdomen via ventral midline celiotomy failed to localize the source of uroperitoneum. Bilateral nephropyelocentesis and antegrade urography were performed, and a defect in the right ureter and stenosis of the left ureter were identified. With the foal in dorsal recumbency in the Trendelenburg position, ureterorrhaphy was performed on the right ureter. After ureterorrhaphy, a ureteral catheter was maintained as a stent. The stenotic left ureter was transected, and ureteroneocystostomy was performed using a drop-in mucosal apposition technique. The ureteral catheter was removed 26 days after surgery. Histopathologic findings suggested that ureteritis of unknown origin was a possible initiating factor for stenosis of the left ureter. The drop-in technique for ureteroneocystostomy may be used successfully for ureteral transposition in horses. Ureterorrhaphy combined with the use of a ureteral stent may be used to repair ureteral defects in foals.

IL-1ra/IGF-1 gene therapy modulates repair of microfractured chondral defects.

Repair of cartilage defects involves sequential participation of specific hormones and growth factors with potential impairment by inflammatory cytokines. We explored an in vivo gene therapy treatment to supply adenoviral vectors carrying the genes of interleukin-1 receptor antagonist protein (IL-1ra) and insulinlike growth factor-1 (IGF-1), hoping to enhance repair of full-thickness equine chondral defects treated with microfracture. We asked whether our treatment could (1) increase proteoglycan and Type II collagen content in the repair tissue, (2) improve the macroscopic and histomorphometric aspect of the repair tissue, and (3) induce prolonged and increased IL-1ra and IGF-1 production in treated joints. Twelve horses had full-thickness chondral defects created in their carpus and stifle followed by microfracture. Joints were injected with either equine IL-1ra/IGF-1 adenoviral preparation or Gey's balanced salt solution. Sixteen weeks later, defect healing was evaluated macroscopically, histologically, histochemically, and biochemically. Production of IL-1ra and IGF-1 was measured by enzyme-linked immunosorbent assay and radioimmunoassay. We found increased proteoglycan content in treated defects along with augmented Type II collagen associated with substantial transgene expression of IL-1ra during the first 3 weeks. These data suggest in vivo gene therapy can improve biologic processes associated with chondral defect repair.