Managing daily surgery schedules in a teaching hospital: a mixed-integer optimization approach

Background: This study examined the daily surgical scheduling problem in a teaching hospital. This problem relates to the use of multiple operating rooms and different types of surgeons in a typical surgical day with deterministic operation durations (preincision, incision, and postincision times). Teaching hospitals play a key role in the health-care system; however, existing models assume that the duration of surgery is independent of the surgeon's skills. This problem has not been properly addressed in other studies. We analyze the case of a Spanish public hospital, in which continuous pressures and budgeting reductions entail the more efficient use of resources. Methods: To obtain an optimal solution for this problem, we developed a mixed-integer programming model and user-friendly interface that facilitate the scheduling of planned operations for the following surgical day. We also implemented a simulation model to assist the evaluation of different dispatching policies for surgeries and surgeons. The typical aspects we took into account were the type of surgeon, potential overtime, idling time of surgeons, and the use of operating rooms. Results: It is necessary to consider the expertise of a given surgeon when formulating a schedule: such skill can decrease the probability of delays that could affect subsequent surgeries or cause cancellation of the final surgery. We obtained optimal solutions for a set of given instances, which we obtained through surgical information related to acceptable times collected from a Spanish public hospital. Conclusions: We developed a computer-aided framework with a user-friendly interface for use by a surgical manager that presents a 3-D simulation of the problem. Additionally, we obtained an efficient formulation for this complex problem. However, the spread of this kind of operation research in Spanish public health hospitals will take a long time since there is a lack of knowledge of the beneficial techniques and possibilities that operational research can offer for the health-care system

Stability of class II malocclusion treatment with the austro repositioner followed by fixed appliances in brachyfacial patients

One of the goals of functional-appliance devices is to modify the vertical growth pattern, solving several kinds of malocclusion. This study aimed to evaluate Class II malocclusion treatment’s stability with Austro Repositioner, followed by fixed appliances, and assess its capacity to modify vertical dimensions in brachyfacial patients. A test group of 30 patients (16 boys and 14 girls, mean 11.9 years old) with Class II malocclusion due to mandibular retrognathism and brachyfacial pattern treated with Austro Repositioner and fixed appliance were compared to a matched untreated Class II control group of 30 patients (17 boys and 13 girls, mean age 11.7 years old). Lateral cephalograms were taken at T1 (initial records), T2 (end of treatment), and T3 (one year after treatment). Statistical comparisons were performed with a paired-sample t-test and two-sample t-tests. Significant improvements in the skeletal Class II relationship were observed in the treated group. The ANB angle decreased (4.75°), the SNB angle increased (3.92°), and the total mandibular length (Co-Pg) increased (8.18 mm) (p < 0.001). Vertical dimensions were also significantly modified, the FMA angle increased (3.94°), LAFH-distance increased (3.15 mm), and overbite decreased (3.35 mm). These changes remained stable one year after treatment. The Austro Repositioner was adequate for treating the skeletal Class II malocclusion resulting from the mandible retrusion in brachyfacial patients

ARREGLOS DE SIEMBRA Y FERTILIZACIÓN ORGÁNICA SOBRE EL CRECIMIENTO DEL CEDRO ROSADO DE LA INDIA (Acrocarpus fraxinifolius) EN UNA PLANTACIÓN DE DOS AÑOS EN LA COMARCA LAS MERCEDES, BOACO

La situación actual de algunos productores del país es crítica debido al avance de la frontera agrícola y a los bajos rendimientos de sus cultivos, que trae como consecuencia una deforestación indiscriminada de los recursos forestales. Como alternativa ante esta problemática surge el Cedro Rosado de la India (Acrocarpus fraxinifolius), una especie forestal que puede contribuir a la reforestación y al aprovechamiento sostenible de la explotación maderera. Por tanto, el presente estudio procura aportar información sobre esta especie al evaluar dos densidades de siembra (400 y 625 plantas por hectárea) y cuatro niveles de lombrihumus (0.5, 1.0, 1.5 y 2.0 kilogramos por planta) sobre el crecimiento de A. fraxinifolius de dos años de desarrollo. El estudio se desarrolló a partir de febrero del 2005 en la finca La Cañada, comarca Las Mercedes, departamento de Boaco. Las unidades experimentales muestreadas en los lotes con densidades de siembra establecidas fueron agrupadas en tres bloques y la fertilización fue aplicada en parcelas dentro de cada densidad de siembra, lo que correspondió a un arreglo de parcelas divididas, en las que se evaluaron las variables de crecimiento. Se realizó análisis de varianza (ANDEVA) tuvieron significación estadística en las densidades de siembra; pero sí en la fertilización. Se obtuvieron 7.224 m en altura de planta, 4.584 m en altura del fuste comercial, 0.11 m en el diámetro a la altura del pecho, 0.33 m en el perímetro a la altura del pecho, 35.09 unidades de ramas, 0.0085 m2 de área basal y 0.0422 m3 de volumen. Los factores estudiados resultaron ser independiente. Los mayores valores en variables se alcanzaron con las dosis de lombrihumus y densidad poblacional más alta. La densidad de 625 plantas por hectáreas y 1.5 y 2.0 kilogramos por planta superaron los 30 m3 de madera. Así mismo, el mayor beneficio costo se obtuvo con la densidad de 625 y 0.5 kilogramos de lombrihumus por planta, con una ganancia de 50.27 por cada dólar invertido

Treatment with implants in patients with diabetes. A 7-year comparative study

Introducción. La implantología oral puede constituir una modalidad terapéutica en el tratamiento prostodóncico de los pacientes con compromiso médico. El estudio muestra la evaluación del tratamiento con implantes en pacientes con diabetes comparados con pacientes sin diabetes. Métodos. 48 pacientes edéntulos totales (24 pacientes diabéticos y 24 no diabéticos) fueron tratados con 96 implan- tes con superficie arenada y grabada Galimplant ® en la mandíbula para su rehabilitación prostodóncica con sobre- dentaduras mandibulares. 2 implantes fueron insertados en cada paciente. Los implantes fueron cargados funcional- mente tras un periodo de tiempo de 6 semanas con retenedores de fricción. Los hallazgos clínicos (implantológicos y prostodóncicos) se han seguido durante 7 años. Resultados. Los resultados indican una supervivencia de los implantes del 95,8%. Durante el periodo de seguimeinto clínico se perdieron 4 implantes (dos implantes en cada grupo). La pérdida de hueso marginal media fué de 0,7 mm en ambos grupos. El 100% de los pacientes fueron tratados mediante una sobredentadura implantorretenida con anclajes de fricción. En 14 pacientes se realizaron cambios en los componentes plásticos de los ataches. El seguimiento clínico medio fue de 82,5 meses (60-102 meses). Conclusiones. Los resultados del presente estudio indican que el tratamiento con implantes dentales en pacientes diabéticos es una terapéutica exitosa sin diferencias entre los pacientes diabéticos y no diabéticos. PALABRAS CLAVE: Implantes dentales, pacientes geriátricos, diabetes mellitus, sobredentaduras, oseo- integración, implantología oral.Introduction. Implant dentistry can to constitute a therapeutic modality in the prosthodontic treatment of medically compromised patients. This study reports the evaluation of treatment with implants in patients with diabetes compared with patients without diabetes. Methods. 48 edentulous patients (24 diabetic patients and 24 non-diabetic patients) were treated with 96 Galimplant ® sand-blasted and acid-etched surface implants for prosthodontic rehabilitation with mandibular overdentures. Two implants were inserted in each patient. Implants were loaded after a healing free-loading period between 6 weeks with locator attaches. Clinical findings (implant and prosthodontics) were followed during at 7 years. Results. Clinical results indicate a survival rate of implants of 95.8% in both groups. Four implant was lost during the follow-up period (two implants in each group). Media marginal bone loss was 0.7 mm in both groups. 100% of patients were treated with overdentures retained with 2 implants with locator attaches. Changes in plastic components of attaches were reported in 14 patients. The media follow-up was of 82.5 months (60-102 months). Conclusions. Clinical results of this study indicate that treatment with dental implants in diabetic patients is a successful implant treatment without differences with nondiabetic patients

Comparison between Sandblasted Acid-Etched and Oxidized Titanium Dental Implants: In Vivo Study

The surface modifications of titanium dental implants play important roles in the enhancement of osseointegration. The objective of the present study was to test two different implant surface treatments on a rabbit model to investigate the osseointegration. The tested surfaces were: a) acid-etched surface with sandblasting treatment (SA) and b) an oxidized implant surface (OS). The roughness was measured by an interferometeric microscope with white light and the residual stress of the surfaces was measured with X-ray residual stress Bragg–Bentano diffraction. Six New Zealand white rabbits were used for the in vivo study. Implants with the two different surfaces (SA and OS) were inserted in the femoral bone. After 12 weeks of implantation, histological and histomorphometric analyses of the blocks containing the implants and the surrounding bone were performed. All the implants were correctly implanted and no signs of infection were observed. SA and OS surfaces were both surrounded by newly formed trabeculae. Histomorphometric analysis revealed that the bone–implant contact % (BIC) was higher around the SA implants (53.49 ± 8.46) than around the OS implants (50.94 ± 16.42), although there were no significant statistical differences among them. Both implant surfaces (SA and OS) demonstrated a good bone response with significant amounts of newly formed bone along the implant surface after 12 weeks of implantation. These results confirmed the importance of the topography and physico–chemical properties of dental implants in the osseointegration.The authors are grateful to the Spanish Government and European Union FEDER by the concession of the project RTI2018-098075-B-C22S

Reconstructing depositional environments through cave interior facies: The case of Galería Complex (Sierra de Atapuerca, Spain)

This work showed that cave sediments are useful for geomorphologic studies and for reconstructing depositional environments. While the cave entrance facies have been extensively studied for their relationship with the fossil and archaeological record, the cave interior facies have received much less attention, although they can provide much information on the geomorphological evolution of the karst. This work presents the stratigraphic and sedimentological study of a section >6 m thick and 10 m long of cave interior sediments of Galería Complex (Sierra de Atapuerca, Spain). Galería Complex is a cavity infill of the Sierra de Atapuerca (Spain), composed of three sections filled by at least 30 m of Pleistocene sediments. This sequence is divided into 5 lithostratigraphic units named from bottom to top: GI – GV. GI unit is 19 m thick of interior facies in the base of the Galería Complex, divided into two sub-unit, GIa and GIb, by the Matuyama-Bruhnes paleomagnetic boundary. GI unit shows an issue with the chronology since has uncoherent between TT-OSL and ESR/U-series and paleomagnetism dates. This work has been done by combining field observation with laboratory sedimentary analysis to characterize the texture and structure of the sediments. Based on these studies, 12 layers and 9 sedimentary facies have been identified. The facies associations indicate a clear separation between GIa and GIb sub-units. GIa sub-unit is dominated by epiphreatic conditions and represents continuous relativity sedimentation during the Early Pleistocene; meanwhile, GIb shows important erosion events and facies with reworked materials that indicate vadose conditions during the Middle Pleistocene. This environmental change is related to the geomorphological evolution of the Arlanzón River. In addition, soft-sediment deformation structures have been described, including faults and low-angle folds...Funding for open access charge: Universidad de Málaga / CBU

Impact of HIV infection on sustained virological response to treatment against hepatitis C virus with pegylated interferon plus ribavirin

[Abstract] It is commonly accepted that human immunodeficiency (HIV) coinfection negatively impacts on the rates of sustained virological response (SVR) to therapy with pegylated interferon plus ribavirin (PR). However, this hypothesis is derived from comparing different studies. The aim of this study was to determine the impact of HIV coinfection on SVR to PR in one single population. In a multicentric, prospective study conducted between 2000 and 2013, all previously naïve hepatitis C virus (HCV)-infected patients who started PR in five Spanish hospitals were analyzed. SVR was evaluated 24 weeks after the scheduled end of therapy. Of the 1046 patients included in this study, 413 (39 %) were coinfected with HIV. Three hundred and forty-one (54 %) HCV-monoinfected versus 174 (42 %) HIV/HCV-coinfected patients achieved SVR (p < 0.001). The corresponding figures for undetectable HCV RNA at treatment week 4 were 86/181 (47 %) versus 59/197 (30 %), p < 0.001. SVR was observed in 149 (69 %) HCV genotype 2/3-monoinfected subjects versus 91 (68 %) HIV/HCV genotype 2/3-coinfected subjects (p = 0.785). In the HCV genotype 1/4-infected population, 188 (46 %) monoinfected patients versus 82 (30 %) with HIV coinfection (p < 0.001) achieved SVR. In this subgroup, absence of HIV coinfection was independently associated with higher SVR [adjusted odds ratio (95 % confidence interval): 2.127 (1.135–3.988); p = 0.019] in a multivariate analysis adjusted for age, sex, baseline HCV RNA load, IL28B genotype, fibrosis stage, and type of pegylated interferon. HIV coinfection impacts on the rates of SVR to PR only in HCV genotype 1/4-infected patients, while it has no effect on SVR in the HCV genotype 2/3-infected subpopulation.Instituto de Salud Carlos III; ISCIII-RETIC RD06/006Instituto de Salud Carlos III; ISCIII-RETIC RD12/0017Andalucía. Junta; PI-0492/2012Andalucía. Junta; AC-0095-201

Evolutionary dynamics at the tumor edge reveal metabolic imaging biomarkers

Human cancers are biologically and morphologically heterogeneous. A variety of clonal populations emerge within these neoplasms and their interaction leads to complex spatiotemporal dynamics during tumor growth. We studied the reshaping of metabolic activity in human cancers by means of continuous and discrete mathematical models and matched the results to positron emission tomography (PET) imaging data. Our models revealed that the location of increasingly active proliferative cellular spots progressively drifted from the center of the tumor to the periphery, as a result of the competition between gradually more aggressive phenotypes. This computational finding led to the development of a metric, normalized distance from F-18-fluorodeoxyglucose (F-18-FDG) hotspot to centroid (NHOC), based on the separation from the location of the activity (proliferation) hotspot to the tumor centroid. The NHOC metric can be computed for patients using F-18-FDG PET-computed tomography (PET/CT) images where the voxel of maximum uptake (standardized uptake value [SUV]max) is taken as the activity hotspot. Two datasets of F-18-FDG PET/CT images were collected, one from 61 breast cancer patients and another from 161 non-small-cell lung cancer patients. In both cohorts, survival analyses were carried out for the NHOC and for other classical PET/CT-based biomarkers, finding that the former had a high prognostic value, outperforming the latter. In summary, our work offers additional insights into the evolutionary mechanisms behind tumor progression, provides a different PET/CT-based biomarker, and reveals that an activity hotspot closer to the tumor periphery is associated to a worst patient outcome