bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of Preoperative Opioid Use on Total Knee Arthroplasty Outcomes
Authors: Smith Savannah R. , Bido Jennifer , Collins Jamie E. , Yang Heidi , Katz Jeffrey N. , Losina Elena 
Published: May 2017

Background:
There is growing concern about the use of opioids prior to total knee arthroplasty (TKA), and research has suggested that preoperative opioid use may lead to worse pain outcomes following surgery. We evaluated the pain relief achieved by TKA in patients who had and those who had not used opioids use before the procedure.

Methods:
We augmented data from a prospective cohort study of TKA outcomes with opioid-use data abstracted from medical records. We collected patient-reported outcomes and demographic data before and 6 months after TKA. We used the Pain Catastrophizing Scale and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) to quantify the pain experiences of patients treated with TKA who had had a baseline score of ≥20 on the WOMAC pain scale (a 0 to 100-point scale, with 100 being the worst score), who provided follow-up data, and who had not had another surgical procedure within the 2 years prior to TKA. We built a propensity score for preoperative opioid use based on the Pain Catastrophizing Scale score, comorbidities, and baseline pain. We used a general linear model, adjusting for the propensity score and baseline pain, to compare the change in the WOMAC pain score 6 months after TKA between persons who had and those who had not used opioids before TKA.

Results:
The cohort included 156 patients with a mean age of 65.7 years (standard deviation [SD] = 8.2 years) and a mean body mass index (BMI) of 31.1 kg/m2 (SD = 6.1 kg/m2); 62.2% were female. Preoperatively, 36 patients (23%) had had at least 1 opioid prescription. The mean baseline WOMAC pain score was 43.0 points (SD = 12.8) for the group that had not used opioids before TKA and 46.9 points (SD = 15.7) for those who had used opioids (p = 0.12). The mean preoperative Pain Catastrophizing Scale score was greater among opioid users (15.5 compared with 10.7 points among non-users, p = 0.006). Adjusted analyses showed that the opioid group had a mean 6-month reduction in the WOMAC pain score of 27.0 points (95% confidence interval [CI] = 22.7 to 31.3) compared with 33.6 points (95% CI = 31.4 to 35.9) in the non-opioid group (p = 0.008).

Conclusions:
Patients who used opioids prior to TKA obtained less pain relief from the operation. Clinicians should consider limiting pre-TKA opioid prescriptions to optimize the benefits of TKA.

Level of Evidence:
Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
Pore-Network Connectivity and Permeability Assessment by Use of Nuclear Magnetic Resonance Log-Inject-Log Method
Authors: Cheng Kai , Heidari Zoya 
Published: May 2017

Summary
Nuclear-magnetic-resonance (NMR) logging is a well-established technology for estimating porosity, pore-size distribution, and permeability in conventional reservoirs. However, the uncertainty associated with these estimates can be significant in complex heterogeneous-carbonate reservoirs, such as those with variable pore size and pore-network connectivity. In such cases, distinguishing isolated-pore space is often impossible by use of well-log measurements and conventional well-log-interpretation methods, which makes permeability evaluation unreliable. This paper proposes a new application of the NMR log-inject-log method to improve assessment of permeability and to distinguish isolated pores from connected pores. We propose injecting manganese-bearing solution in the rock samples and simultaneously analyze NMR measurements before and after injection of the contrast solution. Injection of contrast agents enables eliminating the effect of isolated-pore space from the NMR T2 (spin-spin relaxation time) distribution, which is then used to improve permeability assessment.
To confirm the feasibility of the proposed method for field applications, we conduct NMR laboratory measurements in two carbonate-rock types. We inject manganese-bearing solution into rock samples by use of a coreflood experimental procedure and measure NMR T2 distributions before and after injection. We then estimate isolated porosity and interconnected porosity by taking into account the difference between the NMR T2 distributions acquired before and after the injection of the contrast solution. We introduce a method to calculate the geometric mean of the T2 distribution for interconnected pores, and also to obtain effective free-fluid volume and bound-fluid volume. Finally, we use the T2 distribution corrected for the effect of isolated pores in conventional NMR-based permeability models to improve permeability assessment. We cross validate the NMR-based permeability estimates against Klinkenberg permeability measured by an unsteady-state gas permeameter. The results confirm that the proposed method enables quantifying the isolated and connected pore volume (PV), and finally improves NMR-based permeability assessment. The new method provides estimates of permeability with up to 10% average error in eight carbonate-rock samples, which was a significant improvement compared with the average errors of up to 500% when T2 distribution is not corrected for the effect of isolated pores.
Enhancing Hydrocarbon Permeability After Hydraulic Fracturing: Laboratory Evaluations of Shut-Ins and Surfactant Additives
Authors: Liang Tianbo , Longoria Rafael A. , Lu Jun , Nguyen Quoc P. , DiCarlo David A. 
Published: May 2017

Summary
Fracturing-fluid loss into the formation can potentially damage hydrocarbon production in shale or other tight reservoirs. Well shut-ins are commonly used in the field to dissipate the lost water into the matrix near fracture faces. Borrowing from ideas in chemical enhanced oil recovery (CEOR), surfactants have potential to reduce the effect of fracturing-fluid loss on hydrocarbon permeability in the matrix. Unconventional tight reservoirs can differ significantly from one another, which could make the use of these techniques effective in some cases but not in others. We present an experimental investigation dependent on a coreflood sequence that simulates fluid invasion, flowback, and hydrocarbon production from hydraulically fractured reservoirs. We compare the benefits of shut-ins and reduction in interfacial tension (IFT) by surfactants for hydrocarbon permeability for different initial reservoir conditions (IRCs). From this work, we identify the mechanism responsible for the permeability reduction in the matrix, and we suggest criteria that can be used to optimize fracturing-fluid additives and/or manage flowback operations to enhance hydrocarbon production from unconventional tight reservoirs.
Mechanism of Liquid-Phase Adsorption and Desorption in Coalbed Methane Systems: A New Insight Into an Old Problem
Authors: Li Jing , Li Xiangfang , Shi Juntai , Zhang Hong , Wu Keliu , Chen Zhangxin 
Published: May 2017

Summary
Coalbed-methane (CBM) recovery is a process of desorption rather than adsorption. Traditional experimental studies of methane adsorption/desorption on dry or moist coal samples illustrate little hysteresis between adsorption and desorption isotherms. However, coal porosity is always occupied by water in actual conditions, and few researches focus on the gas sorption from water-saturated coals. In such conditions, there is an equilibrium between methane-molecule dissolution into pore water and adsorption on (or desorption from) pore surface, which indicates a typical liquid/solid sorption process rather than gas/solid sorption process.
This paper presents experiments with methane adsorption/desorption on coal samples saturated with water. To our surprise, the desorption amount changes slightly with different pressure drops, and the desorption ratio for each of our three sets of experiments is only 3.36, 4.98, and 4.21%, respectively. This dramatic result indicates that sorption from saturated aqueous solution presents significant hysteresis, which considerably differs from a gas-phase sorption case (e.g., sorption on dry or moist samples). On the basis of our theoretical analysis, this hysteresis is caused mainly by additional energy consumed by phase behavior (e.g., nucleation) and capillary resistance in a gas/water/solid system. Further, a unified model is established instead of the traditional Langmuir equation to describe the hysteresis phenomenon between adsorption and desorption from an aqueous environment.
Our present work demonstrates that pore water will play a significant role in resisting methane desorption, and the high water saturation in the CBM system will lead to extremely low recovery. Therefore, using the traditional sorption-isotherm curve to predict deliverability of a gas well may result in a large deviation in some cases.
Depositional Controls over the Lacustrine Source Rocks of the Cuyana Basin. An Approach to Model a Mechanical Cyclicity Through an Integrated Analysis of Sequence Stratigraphy, Petrophysics and Rock Properties
Authors: Barredo S. P. , Sosa Massaro A. , Fuenmayor E. , Abalos R. , Stinco L. P. , Abarzúa F. 
Published: May 2017

Abstract
Integrating field and laboratory data is possible if there are strong geologic criteria to relate them. This challenge demands understanding rocks from the fabric and mineralogy up to the architectural elements of rock bodies at a basinal scale. The geological properties of rocks, being them clastic, chemical or biochemical, influence reservoir quality and hydrocarbon producibility, but continental mudrocks/siltstones (shales) are by far more complex because of their depositional nature and highly variable vertical and lateral sedimentary characteristics. Grain size variability and sedimentary structures are common in these rocks. From outcrops, well logs and the source rocks of the Cuyana Basin (Argentina) could be characterized as deposited in lacustrine environments under a strong tectonic and climatic influence. Silty sandstones, limestones, massive and laminated bituminous shales developed in underfilled and balanced to overfilled lakes. They display parallel/inclined/rippled laminations, coarsening/fining upwards patterns, nodules, scour surfaces and pedogenic features. Total organic content may reach 14 % and corresponds to macro and micro floral remains, freshwater invertebrates and kerogen types I and II. These lithofacies are vertically stacked in patterns that can be related to cycles with different mechanical properties. In outcrops and with the help of seismic lines third order depositional sequences representing basin variations in accommodation space were recognized as low accommodation (LAS) to high accommodation (HAS) sequences developed in each of the three rifting stages. Using detailed information about mineralogy and fossil content climate was characterized and fourth order parasequences could be characterized. Fifth order (bedset-rhythms) cycles were interpreted on the basis of outcrops and well logs. Inorganic (especially clays) and organic content, pedogenic fabric, burrows and microfracturing represent weakness planes and as they vary according to these cycles, it was possible to model a mechanical cyclicity along the whole lacustrine column and to analyze their depositional controls. This integrated study has provided relevant data for the understanding of the geological and mechanical properties that will contribute to the optimization of fracture programs.
Empirical PVT Correlations Applied for Colombian Crude Oils: A New Approach
Authors: Valle Tamayo G. A. , Romero Consuegra F. , Mendoza Vargas L. F. , Osorio Gonzalez D. A. 
Published: May 2017

Abstract
A new approach is proposed for adjusting models of empirical equations to predict PVT properties based on current operating conditions of Colombian fields. The results obtained with this new approach are compared with existing correlations.
Using PVT measurement properties from 51 Colombian fields distributed in eight producing oil basins (which represents more than 50% of total Colombian oil production), and through the application of multivariate statistical analysis and average relative error, a new approach was presented focused on two methodological criteria: i) PVT empirical correlations existing adjusted to the operating conditions of Colombian fields. ii) Proposal of empirical equations to estimate the bubble point pressure, oil volume factor and gas ratio in solution, of Colombians crudes.
The inaccuracy of the empirical correlations of the fluids properties contained in the literature, to implemented for Colombian crude is manifested. Correction factors to adjust the experimental data are proposed to reduce the relative error percentage of correlations. A new empirical equation for estimating PVT properties is presented, necessary to solve reservoir engineering and surface production operational problems; by multivariate analysis. The proposed models are compared with the traditional ones, through relative errors based on the PVT measurement acquired, with the aim of ranking them according to its uncertainty.
Through the correlations based on Colombian crudes presented hereby, PVT fluid properties are obtained exhibiting behaviors with a lower order error compared to currently implemented in the industry. This improvement in PVT calculation accuracy will be of invaluable support for simulations and designs applied in Colombian Oil industry.
Methodology for Fluid Contact Monitoring through Surface API Data
Authors: Paredes J. E. , Carbajal Á. , Izquierdo R. , Loyo I. , Perez R. , Perera-Perez L. M. , Larez C. J. 
Published: May 2017

Abstract
There are many methods and tools for estimating the current water/oil (WOC) or gas/oil contact (GOC) in the reservoir. PLT and RST logs can timely monitor the production of each phase in the well and estimate fluid contacts. Material balance or numerical simulation models allow to estimate or predict the depth fluids contacts. In all cases, these tools involve a large amount of human and financial resources and in most cases their accuracy depends on the time expend to calibrate them.
This work proposes a methodology to determine the current depth of the fluid contacts, using surface measurements of the specific gravity of oil (°API) in wells. The proposed methodology is based on the principle of the compositional variation of the fluid in the reservoir and its effect of the properties of the produced fluids. Two diagnostic plots are proposed: (1) for estimating the current depth of the fluids contact at well level and (2) for predicting water breakthrough time. Some real examples of wells showing the behavior outlined in this paper will be presented to support all presented theories. Finally the proposed methodology and diagnostic plots were applied to a reservoir with proven compositional gradient to validate the proposed work.
PPARs in Neurodegenerative and Neuroinflammatory Pathways
Authors: Benedetti E. , Cristiano L. , Antonosante A. , d'Angelo M. , d'Angelo B. , Selli S. , Castelli V. , Ippoliti R. , Giordano A. , Cimini A. 
Published: May 2017

Background:
PPARs are lipid sensors activated by dietary lipids or their metabolites, mainly
fatty acids and eicosanoids, that play critical roles in CNS biology, since brain has a very high lipid content
and has the higher energetic metabolism in the body.

Methods:
In neurodegenerative diseases in addition to metabolic impairment, also neuroinflammation is
observed and PPARs are also closely linked to inflammatory processes. Several studies have revealed a
complicated relationship between the innate immune response and tissue metabolism.

Results:
In the brain, during pathological conditions, an alteration in metabolic status occurs, particularly
involving glucose utilization and production, a condition which is generally related to metabolic changes.

Conclusion:
Taking into account the high expression of PPARs in the brain, this review will focus on the
role of these transcription factors in CNS diseases.
Successful Treatment of Painful Synchondrosis of Bipartite Patella after Direct Trauma by Operative Fixation: A Series of Six Cases
Authors: Radha Sarkhell , Shenouda Michael , Konan Sujith , Lavelle Jonathon , Church Samuel 
Published: May 2017

Introduction:
The patella is the largest sesamoid bone in the body and may have one (77%) or multiple (23%) ossification centres. Patellar and patellofemoral joint abnormalities are a common cause of anterior knee pain but symptomatic bipartite patella is an uncommon problem.

Case Series:
We report a series of six cases of painful synchondrosis in bipartite patellae, all in keen athletes following a direct blow to the anterior aspect of the knee. A complete rupture of the synchondrosis with evidence of retropatellar chondral separation was seen on MRI scan in all cases. Successful surgical fixation was undertaken with complete resolution of symptoms in all patients at an average of three months post-operatively.

Conclusion:
Painful synchondrosis of a bipartite patella in young and active individuals following direct trauma is a relatively rare cause of anterior knee pain, but may be associated with significant morbidity. In cases refractory to non-operative management, successful symptomatic treatment can be achieved by operative fixation.
Результати застосування pентгенендоваскулярного гемостазу бронхіальних артерій у хворих із легеневими кровотечами
Authors: Ponomariova Ye.V. 
Published: May 2017

Актуальність. Питання лікування легеневих кровотеч із застосуванням ендоваскулярного гемостазу бронхіальних артерій у хворих із легеневими кровотечами залишаються предметом активного обговорення і великої кількості публікацій у медицині. Це ускладнення спостерігається в 7–14 % хворих із різними захворюваннями легенів, які надходять у торакальне відділення. Мета дослідження — вивчення ефективності та доцільності використання рентгенендоваскулярних методів лікування у хворих із легеневими кровотечами. Матеріали та методи. За період 2012–2016 рр. у ДУ «Інститут загальної та невідкладної хірургії імені В.Т. Зайцева НАМНУ» рентгенендоваскулярна емболізація бронхіальних артерій виконана 27 хворим із легеневими кровотечами. Вік хворих становив від 29 до 67 років, із них жінок було 17, чоловіків — 10. Значної різниці між чоловіками і жінками не виявлено. Рентгенендоваскулярну емболізацію бронхіальних артерій виконували з використанням ангіографічного комплексу на апараті Tridoros Optimatic 1000 фірми Siemens (Німеччина) і Integris Allura 12 C фірми Phillips (Голландія). Результати. У результаті комплексного обстеження хворих із легеневими кровотечами встановлено, що у 12 хворих (44,4 %) легенева кровотеча обумовлена хронічним обструктивним бронхітом, у 7 (25,9 %) було хронічне обструктивне захворювання легень, у 5 (18,5 %) хворих була виявлена бронхоектатична хвороба, у 2 (7,4 %) — негоспітальна пневмонія, у 1 (3,7 %) хворого — центральний рак легені. Високу ефективність застосування рентгенендоваскулярної оклюзії при легеневих кровотечах різної етіології відзначили більшість авторів. Рецидив кровотечі у віддаленому періоді після рентгенендоваскулярної оклюзії виник у 2 (6 %) неоперабельних хворих із центральним раком легені. Висновки. Ендоваскулярна оклюзія має високу ефективність у вирішенні проблеми зупинки легеневих кровотеч, дозволяє: уточнити діагноз з огляду на наявність специфічних ангіографічних ознак злоякісного ураження; провести ефективний ендоваскулярний гемостаз; виграти час для стабілізації пацієнта з метою планового оперативного лікування.
Patentes mexicanas del Distrito Federal: caracterización por delegación y área tecnológica (2009-2012)
Authors: Meza Rodríguez Nevid Israel , Millán Quintero Gabriela , Pérez Angón Miguel Ángel 
Published: May 2017

El objetivo de este trabajo es estudiar la dinámica de las patentes otorgadas en México a residentes mexicanos ubicados en el Distrito Federal. Se entiende en este trabajo que las patentes dan muestra de la capacidad inventiva y son un elemento que impulsa las actividades de innovación en las empresas. El estudio se realiza como un aporte al desarrollo de políticas públicas encaminadas a la protección intelectual y a la innovación. Se encuentra que el Distrito Federal concentra casi la mitad de las patentes otorgadas a residentes mexicanos; las patentes corresponden a un nivel de intensidad tecnológica media-alta y tienen una dinámica de crecimiento constante durante el periodo estudiado.
Devenires de la autoridad en la escuela
Authors: Pedranzani Beatriz , Martín Marisol , Díaz Carlos , Espeleta Alejandro 
Published: May 2017

El presente trabajo da cuenta de una experiencia de intervención en una escuela secundaria de la ciudad de Villa Mercedes, San Luis, a través de la realización de un taller de reflexión sobre la autoridad docente. El taller se desarrolló con docentes de 6.to año con el objetivo de crear condiciones para pensar colectivamente las prácticas profesionales en relación a la autoridad, valiéndonos del espacio grupal como espacio intermediario. Permitió recuperar la dimensión subjetiva a partir de la indagación en una instancia individual y colectiva que favoreció pensar y pensarse en el "entre" de un dispositivo grupal, que posibilitó nominar el malestar y asimismo auguró la posibilidad de construir nuevas significaciones en relación al tema de la autoridad, mediante el desarrollo del pensamiento crítico, la autonomía de opinión y de criterio, como así también la fuerza creadora de esos miembros del grupo para abrirse a la creatividad y el devenir.
Lo singular del empleo de los cirujanos dentistas
Authors: González Pérez Cándido 
Published: May 2017

Este trabajo es producto de una investigación que en su primera parte se basó en una metodología cuantitativa al aplicar una encuesta a la totalidad de estudiantes de primer ingreso de la carrera de cirujano dentista, en la segunda en una cualitativa donde se entrevistó a los egresados de dos generaciones y a un empleador que ofreció información desde su perspectiva como investigador, docente, funcionario y patrón. Se contrastan los resultados con dos teorías antagónicas entre sí donde una privilegia el actuar del individuo para basar sus sustentos, y la otra le otorga el papel determinante a la sociedad donde el seno familiar es definitorio para que los estudiantes accedan al éxito escolar y laboral. Una de las características de este escrito es que la totalidad de la información presentada fue extraída de primera mano.
Thermal, mechanical and hydrodynamic analysis to optimize the design of molten salt central receivers of solar tower power plants.
Authors: M. R. Rodríguez-Sanchez  , M. Venegas-Bernal  , C. Marugán-Cruz  , C. Marugán-Cruz  , D. Santana  
Published: May 2017

One of the main problems of the molten-salt solar power tower plants is the reliability and lifetime estimation of central-receivers. The receiver must withstand high working temperatures, molten salt corrosion and important solar-flux transient thermal processes that lead to thermal stresses and fatigue. A thermal, mechanical and hydrodynamic analysis of the receiver has been carried out assuming constant temperature at each cell used in the simulations, but assuming axial and circumferential variation temperature in the whole perimeter of the receiver. The optimal design of this kind of receivers has been found varying the number of panels and the external diameter of the tubes. It has been obtained that the maximum film temperature and thermal stress follows a different evolution than the pressure drop, therefore it is necessary to make a compromise between them. The optimal receiver design must reduce the wall and film temperatures and the thermal stresses, assure the correct operation and prolong the lifetime of the receivers. In addition, the chosen design must have the highest thermal efficiency, reducing the number of heliostat and therefore the initial capital investment cost of the solar plant will be lower.