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The size and shape of nanoparticles have a profound effect on the properties of nanocomposites. For instance, the lateral dimensions of graphene oxide (GO) platelets affect several properties, including their antibacterial and pharmacokinetic functions. However, the impact of lateral dimensions has been poorly studied in nanocomposites, and their effect on hydrogels is still unknown. The current study aims to determine the effect of GO lateral dimensions on the mechanical, rheological, thermal, and antibacterial properties of gelatin hydrogels. The hydrogels were fabricated via photopolymerization of methacrylated gelatin and GO derived from the oxidation of commercial graphene. The observations indicate that an increase in GO sheets improves the mechanical strength with an increase in compressive modulus and a low mechanical hysteresis (<10%). Furthermore, low mechanical energy is dissipated even after several deformation cycles. The nanocomposite hydrogels demonstrated bactericidal effects on two clinical strains with an extensively drug-resistant phenotype, primarily through contact. Additionally, an increment in lateral dimensions increased the bactericidal capacity of Gram-negative strains. Thus, the significant effect of the lateral dimensions of GO sheets on the properties of hydrogels is demonstrated.

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PURPOSE: This study investigated the association between chondrolabral damage and time to arthroscopic surgery for slipped capital femoral epiphysis (SCFE). METHODS: This was a descriptive retrospective study that enrolled patients with SCFE who underwent hip arthroscopy for femoral osteochondroplasty after SCFE fixation. SCFE type, time from SCFE symptom onset or slip fixation surgery to hip arthroscopy and intraarticular arthroscopic findings were recorded. Acetabular chondrolabral damage was evaluated according to the Konan and Outerbridge classification systems. Nested analysis of variance and the chi-squared test were used for statistical analyses. RESULTS: We analyzed 22 cases of SCFE in 17 patients (five bilateral). The mean age at the time of hip arthroscopy was 13.6 years-old (8-20), and mean time from SCFE fixation to arthroscopy was 25.1 months (3 weeks to 8 years). Labral frying was present in 20 cases, labral tears in 16 and acetabular chondral damage in 17. The most frequent lesion was type 3 (41%) (Konan classification). Two cases had a grade III and 1 had a grade II acetabular chondral lesion (Outerbridge classification). Positive associations were observed between time from SCFE to hip arthroscopy and hip intraarticular lesions evaluated using Konan (p = 0.004) and Outerbridge (p = 0.000) classification systems. There was no association between SCFE severity (chi-squared = 0.315), stability (chi-squared = 0.558) or temporality (chi-squared = 0.145) type and hip intraarticular lesions. CONCLUSION: A longer time from SCFE symptom onset and fixation to hip arthroscopy is associated with greater acetabular chondrolabral damage. LEVEL OF EVIDENCE: IV.

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Palladium N,N'-bis(3-allylsalicylidene)o-phenylenediamine complex (PdAS) immobilized onto mesoporous polymeric methyl acrylate (MA) based resins (PdAS(x)-MA, x = 1, 2, 5, or 10 wt.%) were successfully prepared as heterogeneous catalysts for the Heck reaction. The catalysts were synthesized via radical suspension polymerization using PdAS as a metal chelate monomer, divinylbenzene and MA as co-monomers. The effect of the PdAS(x) content on the physicochemical properties of the resins is also reported. The catalysts were characterized by using a range of analytical techniques. The large surface area (>580 m2·g-1) and thermal stability (up to 250 °C) of the PdAS(x)-MA materials allows their application as catalysts in the C-C coupling reaction between iodobenzene and MA in the presence of trimethylamine at 120 °C using DMF as the solvent. The PdAS(10)-MA catalyst exhibited the highest catalytic performance with no significant catalytic loss being observed after five reuses, thereby indicating excellent catalyst stability in the reaction medium.

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INTRODUCTION: Acetabular cartilage lesions are frequently found during hip arthroscopy. In the hip joint they mostly occur secondary to a mechanical overload resulting from a pre-existing deformity as hip dysplasia or femoroacetabular impingement (FAI). Lesions identified during arthroscopy can vary greatly from the earliest stages to the most advanced (full-thickness lesions). These lesions occur in the acetabulum in the early stages of joint damage. Microfractures are indicated in full-thickness chondral defects. Ideally, these lesions must be focal and contained. METHODS: The procedure begins debriding all the unstable chondral tissue of the lesion. The edges should have a net cut towards stable and healthy cartilage. It is recommended to make as many perforations as possible using arthroscopic awls. They should be ideally 4 mm deep and must have a vertical orientation to the surface. The suggested distance between perforations is of 3-4 mm. Once the treatment of the chondral lesion with the microfractures is complete, the labrum must be repaired. The repair of the labrum transforms in most of the cases the defect in a contained lesion containing better the clot in the lesion after the microfractures have been performed. It is also important to correct the bone deformity that has caused this lesion, which mostly corresponds to a "cam" deformity. CONCLUSION: Clinical studies confirm good short- and medium-term results in full-thickness chondral lesions treated with microfractures in the absence of osteoarthritis. However, it is difficult to determine if these results are only due to the microfractures, as this treatment is always complemented with several other factors and surgical procedures, such as labrum repair, correction of underlying bone deformity or change in postoperative activity of operated patients.

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PURPOSE: To report the interobserver and intraobserver reliability of 3 chondral damage classifications used to assess articular cartilage damage during hip arthroscopy. METHODS: A prospective multicenter study was performed during April and May 2013. Inclusion criteria were all patients who underwent hip arthroscopy for femoroacetabular impingement (FAI) and had evidence of chondral damage at the time of surgery. Intra-articular recordings were obtained during the operation in a standardized way. These recordings were obtained from 2 different hospitals in 2 countries by 3 different surgeons. Four fellowship-trained orthopaedic surgeons, with at least 2 years postfellowship experience in hip arthroscopy, independently analyzed the recordings 2 times in randomized order and 4 months apart. They classified the lesions according to the Outerbridge, Beck, and Haddad classifications of chondral damage. The values obtained were used for interobserver and intraobserver analysis. Percentage of agreement and weighted Cohen κ values were calculated. RESULTS: Absolute agreement between observers was present in 12.5% of the cases for the Outerbridge classification, in 20% of the cases for the Beck classification, and in 40% of the cases for the Haddad classification. For interobserver reliability, the average weighted Cohen κ values were 0.28 (95% confidence interval [CI], 0.16 to 0.39), 0.33 (95% CI, 0.24 to 0.41), and 0.47 (95% CI, 0.42 to 0.51) for the Outerbridge, Beck, and Haddad classification systems, respectively. For intraobserver reliability, the mean Cohen κ values were 0.62, 0.63, and 0.68 for the Outerbridge, Beck, and Haddad classification systems, respectively. CONCLUSIONS: In our series, the Haddad classification had the best interobserver reliability. There was no difference in the intraobserver reliability among the 3 classifications studied. LEVEL OF EVIDENCE: Level III, diagnostic study of nonconsecutive patients (without consistently applied reference gold standard).

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The use of hip arthroscopy, as a surgical technique, has increased significantly over the past ten years. The procedure has shown good and excellent results in symptom relief and function improvement for patients with femoro-acetabular impingement (FAI) and concurrent chondro-labral lesions. It is also a reliable method to correct the characteristic pathomorphologic alteration of FAI. However, surgical results are less successful among patients with advanced articular damage and secondary hip osteoarthritis. The aim of this article is to present some clinical and imagenological tools to discriminate the good candidates for arthroscopic FAI treatment from those who are not, due to extensive articular damage.

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PURPOSE: To determine the incidence of and factors that contribute to the development of hypothermia during hip arthroscopic surgery. METHODS: An analytic observational study was carried out in a cohort of 73 consecutive patients. All patients underwent hip arthroscopy for the treatment of femoroacetabular impingement. The patients' core temperature (esophageal) was measured throughout the surgery. Relevant information was collected on the patients (age, gender, body mass index, blood pressure) and on the procedure (volume and temperature of saline solution, pressure of fluid pump, surgery time, room temperature). The corresponding statistical analysis was performed with Stata 10.0 (StataCorp, College Station, TX), by use of a repeated-measures generalized estimating equations model. RESULTS: The patients' mean age was 33 years, and there were 39 female and 34 male patients. The mean body mass index was 23.9; systolic blood pressure, 97.5 mm Hg; and diastolic blood pressure, 52.2 mm Hg. The incidence of hypothermia below 35°C (95°F) was 2.7%. The multivariate statistical analysis of the results showed a direct relation between hypothermia and surgery time of more than 120 minutes (P < .001). There was an inverse relation between core body temperature and surgery time (P < .001), with a drop of 0.19°C/h (32.342°F/h). Of the patients, 68.22% had a decrease in temperature of more than 0.5°C (32.9°F) until the end of surgery. There was also a direct relation between core body temperature and saline solution temperature (P < .001), body mass index (P < .01), and diastolic blood pressure (P < .03). CONCLUSIONS: The incidence of hypothermia below 35°C (95°F) in patients who underwent hip arthroscopy for the treatment of femoroacetabular impingement is 2.7%. The factors that contribute toward the development of hypothermia during hip arthroscopic surgery are prolonged surgery time, low body mass index, low blood pressure during the procedure, and low temperature of the arthroscopic irrigation fluid.

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