Hip Arthroscopic Surgery for Femoroacetabular Impingement: A Prospective Analysis of the Relationship Between Surgeon Experience and Patient Outcomes.

Background:Hip arthroscopic surgery is a rapidly growing procedure, but it may be associated with a steep learning curve. Few studies have used patient-reported outcome (PRO) surveys to investigate the relationship between surgeon experience and patient outcomes after the arthroscopic treatment of femoroacetabular impingement (FAI). Hypothesis:Patients undergoing hip arthroscopic surgery for the treatment of FAI in the early stages of a surgeon's career will have significantly worse outcomes and longer procedure times compared with patients treated after the surgeon has gained experience. Study Design:Cohort study; Level of evidence, 2. Methods:Patients undergoing hip arthroscopic surgery for FAI and labral injuries were prospectively enrolled during a sports medicine fellowship-trained surgeon's first 15 months of practice. Patients were stratified into an early group, consisting of the first 30 consecutive cases performed by the surgeon, and a late group, consisting of the second 30 consecutive cases. Radiographic and physical examinations were performed preoperatively and postoperatively. PRO surveys, including the 12-item Short Form Health Survey (SF-12), the modified Harris Hip Score (mHHS), and the Hip disability and Osteoarthritis Outcome Score (HOOS), were administered preoperatively and at a minimum of 1 year postoperatively. Results:There was no difference between the early and late groups for patient age (37.2 ± 11.5 vs 35.3 ± 10.8 years, respectively; P = .489), body mass index (25.6 ± 4.0 vs 25.1 ± 4.5 kg/m2, respectively; P = .615), or sex (P = .465). There was a significantly increased procedure time (119.3 ± 21.0 vs 99.0 ± 28.6 minutes, respectively; P = .002) and traction time (72.7 ± 21.4 vs 59.0 ± 16.7 minutes, respectively; P = .007) in the early group compared with the late group. Mean postoperative PRO scores significantly improved in both groups compared with preoperative values for all surveys except for the SF-12 mental component summary. No differences were found in PRO score improvements or complication rates between the early and late groups. Conclusion:The total procedure time and traction time decrease after a surgeon's first 30 hip arthroscopic surgery cases for FAI and labral tears, but patient outcomes can similarly improve regardless of surgeon experience in the early part of his or her career

Use of Air Arthrograms to Aid in Joint Distraction During Hip Arthroscopic Surgery Decreases Postoperative Pain and Opioid Requirements.

BackgroundPositive-pressure air arthrography and venting of the hip capsule are techniques used to decrease the traction forces needed for joint distraction during hip arthroscopic surgery. Little is known about the effects that these techniques have on postoperative pain.HypothesisPositive-pressure air arthrography and venting during hip arthroscopic surgery will decrease patient-reported pain and narcotic requirements in the acute postoperative setting.Study designCohort study; Level of evidence, 3.MethodsA retrospective cohort analysis was conducted to analyze 35 patients who underwent positive-pressure air arthrography and venting to aid joint distraction during hip arthroscopic surgery versus a group with similar demographics, pathologies, and treatments who did not undergo air arthrography. Numeric pain rating scale (NPRS) scores and medication administration including narcotic and nonnarcotic analgesia in the postanesthesia care unit (PACU) were tracked and compared.ResultsThe maximum (7.17 vs 4.97, respectively), minimum (2.43 vs 1.09, respectively), and mean (5.15 vs 3.11, respectively) NPRS scores were all higher in the control group compared with the air arthrogram group (P < .001, P = .007, and P < .001, respectively). The administration of oral morphine equivalents (OMEs) during the PACU stay was significantly lower in the air arthrogram group, with a mean of 36.75 ± 11.37 OMEs, compared with 44.53 ± 16.06 OMEs in the control group (P = .023). There was no difference in postoperative nonopioid medications, such as ketorolac or acetaminophen, given between groups.ConclusionPatients undergoing hip arthroscopic surgery with air arthrography and venting used to aid distraction had significantly less postoperative pain and required a lower total dosage of opioids during their PACU stay when compared with patients who underwent hip arthroscopic surgery without air arthrography

Do Outcomes of Arthroscopic Subscapularis Tendon Repairs Depend on Rotator Cuff Fatty Infiltration?

Background:Rotator cuff fatty infiltration has been correlated with poorer radiographic and clinical outcomes in supraspinatus and infraspinatus tendon repairs, but this has not been well-studied in subscapularis tendon repairs. Purpose:To evaluate the influence of preoperative rotator cuff fatty infiltration on postoperative outcomes for patients undergoing arthroscopic subscapularis tendon repair. Study Design:Cohort study; Level of evidence, 3. Methods:Patients who underwent arthroscopic subscapularis repair between 2010 and 2016 were retrospectively identified, and demographic data and surgical findings were recorded. The extent of fatty infiltration was determined on preoperative magnetic resonance imaging by the Fuchs modification of the Goutallier classification. At the most recent follow-up, patients completed the Patient-Reported Outcomes Measurement Information System for Upper Extremity (PROMIS-UE) computer adaptive test and a postoperative visual analog scale for pain. The distribution of fatty infiltration was compared between patients undergoing subscapularis tendon repair versus subscapularis tendon repair combined with a posterior cuff repair. Outcomes were compared for patients using Goutallier grade 0-1 versus grade ≥2 changes in each rotator cuff muscle. Multivariate linear regression analysis was performed to evaluate the influence of muscle quality, as well as demographic factors, on PROMIS-UE scores. Significance was defined as P < .05. Results:There were 140 shoulders included (mean age, 61.8 years; 42.1% female; mean follow-up, 51.7 months). The prevalence of Goutallier grade 2 changes or higher was significantly greater in patients with multitendon repair relative to isolated subscapularis tendon repair. For the overall group of all patients undergoing subscapularis tendon repair, whether in isolation or as part of a multitendon repair, PROMIS-UE scores were significantly lower for patients with infraspinatus muscle grade 2 or higher Goutallier changes relative to grade 0 or 1. After adjustment for age, body mass index, patient sex, and fatty infiltration in other rotator cuff muscles, poor infraspinatus muscle quality remained the only significant predictor for lower PROMIS-UE scores. Conclusion:Patients undergoing arthroscopic subscapularis tendon repair with poor infraspinatus muscle quality had worse patient-reported outcomes. This was true whether subscapularis tendon repair was isolated or was performed in conjunction with supraspinatus and infraspinatus tendon repairs

A shared neural ensemble links distinct contextual memories encoded close in time.

Recent studies suggest that a shared neural ensemble may link distinct memories encoded close in time. According to the memory allocation hypothesis, learning triggers a temporary increase in neuronal excitability that biases the representation of a subsequent memory to the neuronal ensemble encoding the first memory, such that recall of one memory increases the likelihood of recalling the other memory. Here we show in mice that the overlap between the hippocampal CA1 ensembles activated by two distinct contexts acquired within a day is higher than when they are separated by a week. Several findings indicate that this overlap of neuronal ensembles links two contextual memories. First, fear paired with one context is transferred to a neutral context when the two contexts are acquired within a day but not across a week. Second, the first memory strengthens the second memory within a day but not across a week. Older mice, known to have lower CA1 excitability, do not show the overlap between ensembles, the transfer of fear between contexts, or the strengthening of the second memory. Finally, in aged mice, increasing cellular excitability and activating a common ensemble of CA1 neurons during two distinct context exposures rescued the deficit in linking memories. Taken together, these findings demonstrate that contextual memories encoded close in time are linked by directing storage into overlapping ensembles. Alteration of these processes by ageing could affect the temporal structure of memories, thus impairing efficient recall of related information

Microemulsions for colorectal cancer treatments: general considerations and formulation of methotrexate

[Abstract] Microemulsions combine the advantages of emulsions with those of nanocarriers, overcoming the stability problems of the former and providing facile scalable systems with compartments adequate for high drug loadings. Recently, microemulsions are gaining attention in the formulation of anticancer drugs not only for topical treatment, but also for systemic delivery as well as for the development of theranostic systems. The aim of this paper is two-fold. First, an updated review about general features, preparation, characterization and pharmaceutical applications, with a special focus on colorectal cancer, is provided. Second, a case study of formulation of methotrexate in microemulsions is presented. Various essential oils (menthol, trans-anethole, α-tocopherol) and surfactants (TPGS-l000, Maxemul 6112, Noigen RN-20) were investigated for the preparation of o/w microemulsions for the delivery of methotrexate, and the ability of methotrexate-loaded microemulsions to inhibit cancer cell growth was then evaluated. Disregarding the surfactants used, menthol and trans-anethole led to cytotoxic microemulsions, whereas α-tocopherol based-formulations induced cell proliferation. These findings highlight the role that the oily component may play in the efficacy and safety of the microemulsions.México. Consejo Nacional de Ciencia y Tecnologia; No. CB-2011/ 168472Ministerio de Economia y Competitividad; SAF2014-52632-RRed Gallega de Investigación sobre Cáncer Colorrectal; R2014/03

Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin

Resolved properties of a luminous "hinge clump" in the compact group of galaxies NGC\,6845

We study the properties of one of the most luminous hinge clumps, located on the compact group of galaxies NGC6845. Using IFS from GMOS/Gemini, complemented with archival MUSE data, we obtain oxygen abundances, ages, star formation rates, velocity fields and we also performed a single stellar populations modeling to understand the SFH of the hinge clump localized in NGC6845. We found that the hinge clump sits in a tail, having a SFR of 3.4$M_{\odot}yr^{-1}$, which is comparable with a few other extreme cases, e.g., the star clusters in the Antennae galaxy and other reported hinge clumps in the literature. In fact, this clump represents ~15\% of total SFR of NGC6845A. Large-scale modeling of the observed velocity field of NGC6845A rules out the scenario on which this hinge clump was a satellite galaxy. Indeed, its kinematics is compatible with the galactic disk of NGC6845A. Its abundance, mean value of 0.4Z$_{\odot}$, is also consistent with the metallicity gradient of the galaxy. Our analysis, suggest that the hinge clump is formed by multiple stellar populations instead of a single burst, thus having a large range of ages. We found that central clump is encompassed by a ring-like structure, suggesting that the ring-like structure represents a second-generation of star formation. In addition, the analysis of the diagnostic diagram indicates that this central region can also be being ionized by shock from stellar and supernovae winds. Finally, the derived SFR density $\Sigma=9.7M_{\odot}yr^{-1}kpc^{-2}$ of the central clump, place it in starburst regime, where gas inflows should provide gas to maintain the star formation. This work shows a resolved example of an extreme localized starburst in a compact group of galaxies.Comment: 13 pages, 11 figure

Análisis aerodinámico de perfiles con múltiples superficies para control y redirección de flujo

En este trabajo se presenta un modelo numérico inestacionario y no-lineal para el cómputo de las cargas aerodinámicas y el análisis del flujo alrededor de perfiles aerodinámicos con múltiples superficies de control distribuidas a lo largo del contorno. La acción de estos elementos de control intenta asemejarse a la de las plumas en las alas de las aves, las cuales redireccionan el flujo de aire entre ellas para lograr mayor control, estabilidad y maniobrabilidad. El interés en este tipo de perfiles con múltiples superficies actuadoras inspiradas en el vuelo natural es debido a su potencial aplicación en vehículos aéreos no-tripulados (UAVs) inteligentes con alas que cambian de forma y configuración (morphing-wings). El modelo aerodinámico desarrollado y presentado en este trabajo está basado en la versión bidimensional del método de red de vórtices no-lineal e inestacionario. El método de red de vórtices inestacionario permite estimar la generación y evolución espacio-temporal de las estelas vorticosas originadas en los bordes afilados de los sólidos inmersos, así como la interacción aerodinámica entre éstas y las superficies sólidas que encuentran en su recorrido. Finalmente, el método permite estimar las cargas aerodinámicas sobre todas las superficies sólidas. En este esfuerzo, se estudian diversos patrones de accionamiento de las superficies de control y se analizan las características del flujo generado y las cargas aerodinámicas resultantes a distintos ángulos de ataque del perfil. Se estudian, no sólo las características estacionarias de las configuraciones, sino también, las inestacionarias a través de la evolución de las estelas. En todos los casos las superficies de control poseen movimientos prescritos. Un tipo de actuación consiste en el movimiento de la superficie de control hasta que adquiere un ángulo determinado, el cual permanece fijo posteriormente. Otro tipo de actuación presentada a modo ilustrativo consiste en el movimiento periódico de las superficies. Esto último, como paso previo a la futura modelación del fenómeno de interacción fluido-estructura que resultaría si las articulaciones de las superficies móviles tuvieran rigidez no infinita como en los casos aquí presentados.Publicado en: Mecánica Computacional vol. XXXV, no. 26Facultad de Ingenierí

Effect of acid oxidation treatment on adsorption properties of arc-discharge synthesized multiwall carbon nanotubes

The effect of nitric/sulfuric acid oxidation treatment on commercial arc-discharge multiwall carbon nanotubes was studied. Purification and structure modifications were assessed via Transmission Electron Microscopy and Thermogravimetric Analysis; while changes in adsorption properties were monitored by nitrogen and methane adsorption isotherms. After treatment, nitrogen isotherms present hysteresis loop and an increased BET surface area; while adsorption energies obtained from isosteric heat profiles revealed a marked decrease. We propose an explanation for these findings and use macroscopic experimental data to gain insight on acid oxidation effect on the material.Se estudió el efecto de la oxidación ácida por medio de mezclas sulfúrico/nítrico, de nanotubos comerciales de pared múltiple sintetizados por el método de la descarga de arco. Para evaluar el grado de pureza y las modificaciones estructurales se utilizaron las técnicas de Microscopía Electrónica de Transmisión y Termogravimetría; mientras que los cambios en las propiedades de adsorción fueron monitoreados por medio de la realización de isotermas a distintas temperaturas utilizando gases simples como Nitrógeno y Metano. Luego del tratamiento oxidativo, se observó la aparición de ciclos de histéresis en las isotermas al mismo tiempo que el área superficial según BET se incrementó. Por otro lado, los calores isostéricos obtenidos evidenciaron una disminución importante. Proponemos una explicación posible para estos hallazgos y hacemos uso de la información experimental obtenida para revelar detalles del mecanismo de oxidación de los Nanotubos.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasCentro de Química Inorgánic

Optimal Nitrogen Fertilization to Reach the Maximum Grain and Stover Yields of Maize (Zea mays L.): Tendency Modeling

Utilization of maize stover to the production of meat and milk and saving the grains for human consumption would be one strategy for the optimal usage of resources. Variance and tendency analyses were applied to find the optimal nitrogen (N) fertilization dose (0, 100, 145, 190, 240, and 290 kg/ha) for forage (F), stover (S), cob (C), and grain (G) yields, as well as the optimal grain-to-forage, cob-to-forage, and cob-to-stover ratios (G:F, C:F, and C:S, respectively). The study was performed in central Mexico (20.691389° N and −101.259722° W, 1740 m a.m.s.l.; Cwa (Köppen), 699 mm annual precipitation; alluvial soils). N-190 and N-240 improved the individual yields and ratios the most. Linear and quadratic models for CDM, GDM, and G:F ratio had coefficients of determination (R2) of 0.20–0.46 (p < 0.03). Cubic showed R2 = 0.30–0.72 (p < 0.02), and the best models were for CDM, GDM, and the G:F, C:F, and C:S DM ratios (R2 = 0.60–0.72; p < 0.0002). Neither SHB nor SDM negatively correlated with CDM or GDM (r = 0.23–0.48; p < 0.0001). Excess of N had negative effects on forage, stover, cobs, and grains yields, but optimal N fertilization increased the proportion of the G:F, C:F, and C:S ratios, as well as the SHB and SDM yields, without negative effects on grain production