bluuebunny/crossref_metadata_2025 huggingface dataset:
Digital Solutions Using Advanced Computational Techniques to Simulate Hole Cleaning
Authors: Deshpande Kedar , Celigueta Miguel Angel , LaTorre Salvador , Onate Eugenio , Naphade Pravin
Published: November 2019

Cuttings transport and hole-cleaning is a challenging issue associated with the efficiency of wellbore hydraulics and drilling operation. Traditional methods used to understand hole cleaning problems are based on field observations and extensive flow loop testing to formulate empirical correlations and mechanistic models. The focus of this study is to create digital twin utilizing advanced simulation techniques that provides better insight for cuttings transport and hole-cleaning. This study explores the use of Eulerian-Lagrangian based numerical techniques to estimate critical flow rate needed for efficient hole cleaning. Digital twin for the cuttings transport is formulated utilizing three dimensional Navier stokes equations employing combination of Eulerian and lagrangian approaches to model the drilling mud flow and cuttings interaction with the drilling mud, wellbore walls and between cuttings themselves. One of the important model to estimate the drag force on cuttings is modified for non-spherical cuttings shape coupled with non-newtonian Herschel Bulkley behavior of the drilling mud in this work. The influence of important parameters, such as fluid rheology, rotation of drill-string, and inclination of wellbore on the hole-cleaning process is investigated. Digital solutions are compared against the published data for Newtonian and non-Newtonian drilling fluids under different wellbore configurations. The advanced computational simulation involving novel drag force correlation and unique combination of numerical methods allowed to create digital twin for cuttings transport process accurately. The numerical strategy utilizing modified drag law showed a very good match with experimental results for straight vertical wellbore, the cuttings transport velocity estimated by digital solutions was within 5% difference of experimental results. Further upon validation, numerical results are successfully computed for drill -string rotation effects which clearly showed physics of cuttings transported efficiently with added energy due to rotation. The phenomenon of cuttings bed sliding in inclined and horizontal wellbores is also correctly simulated with the proposed drag law and numerical methods. The proposed methodology works without any issues with high concentration of cuttings and provides detailed insight into cuttings flow path and effect of various operational parameters on hole cleaning. Advanced computational simulations and modification of drag force law assisted in formulating digital twin that provided excellent insights in understanding effects of operational parameters for efficient hole cleaning.
Lesson Learned from Production Enhancement Pilot for Medium Oil Viscosity Formation in Minagish Oil Field Kuwait
Authors: AL-Rashidi Hamad , Jamsheer Abdullah , AL-Azmi Talal , Muhsain Batoul , Abu-Eida Abdullah , AL-Methen Badriya , Mousa Saad , AL-Harbi Faseil , Duncan Bruce , Safar Abdulaziz , AL-Azmi Waled , Desoky Waleed , AL-Sabah Fahad , AL-Yaseen Musaeb , AL-Hajri Mohsen , AL-Hajri Abdulrahman , AL-Mutwa Bandar , AL-Awadhi Hisham , Almeida Dwane , AL-Zanki Farooq
Published: November 2019

The strategy of the Kuwait Oil Company (KOC) is to implement key/emerging technologies at a country wide scale to meet future oil demand and production targets as planned in KPC 2040 strategy through overcome the field's challenges. KOC's Optimization strategy focuses on: Increased and optimize oil production from production optimizationsExtension of field life

Production interruption associated with pressure build up in reservoir, wellbore and flow lines have observed among many wells in West Kuwait fields perforated in Upper Burgan formation, which has a great impact on the company strategy. Tight emulsion phenomena is consider one the most challenging problems in West Kuwait wells due to the nature of asphaltenic crudes and high water cut production percentage. Traditional approaches to reduce high pressure and break the emulsion phase through injecting chemical near wellhead or in annuls is usually not successful in most cases and require large amount of chemical. Due to the complexity of this issue, a novel approach was used in this study to identify the main causes of oil production reduction and overcome the challenge to maximize oil production in West Kuwait fields.
Experimental Study of Fractured Carbonate Rock Model for Oil Recovery Evaluation
Authors: Bernardes de Almeida Sarah , Pereira André , Ruidiaz Eddy , Winter Alessandra , Vidal Vargas Janeth , Koroishi Erika , Vidal Trevisan Osvair , Valladares de Almeida Rafael
Published: November 2019

Objectives/Scope

The aim of this work is the experimental study of a fractured carbonate rock model for oil recovery evaluation. For this, a new experimental routine regarding petrophysical characterization was developed and validated. The evaluation of oil recovery was performed by mass balance. Also, the heterogeneity of the fractured rock model and the distribution of the saturations was calculated by X-ray computed tomography.

Methods, Procedures, Process

An induced fractured was created adding a longitudinal spacer (Lie, 2013) at a reservoir carbonate rock plug from a Brazilian pre-salt reservoir. Drainage process was performed by forced displacement using synthetic formation water and oil from the same reservoir rock. The model was aged at 63°C for 28 days. X-ray computerized tomography was used for porosity and fluid saturations calculations. The initial injection rate was 0.1 cm3/min. After reaching the saturation plateau, the rate was decreased to 0.05 cm3/min to evaluate possible incremental recovery.

Results, Observations, Conclusions

The developed methodology allowed the construction of a porous media with an induced fracture representative from a naturally fractured reservoir. The rock sample was cut lengthwise with a metal saw. A POM spacer was used to represent the fracture, and glass beads filled the fracture in order to give a representative porosity to the fractured rock model. The petrophysical properties of the matrix and the fracture were obtained during each step of the fractured rock model construction. The matrices porosities obtained were 8% and 14%, and the permeabilities 68 mD and 40 mD, respective to each semicylinder of the plug. The fracture porosity and permeability obtained were 1.6% and 146 Darcy, respectively. For the entire fractured rock model, the porosity was 12.5% and the permeability 5 Darcy. The approach to mimic a drainage method reached an initial water saturation of 57%. The recovery factor obtained by the seawater injection at a 0.1 cm3/min flow rate was 30%. An increase of 3% was obtained when the flow was decreased to 0.05 cm3/min. The CT scan measurement yields additional information such heterogeneity of the model through the porosity profile in the fracture, matrix, and the entire fractured rock model.

Novel/Additive Information

This work presents an innovative methodology to mimic a natural fractured reservoir model which provided a full routine for petrophysical properties evaluation of a physical model. Besides, computed tomography (CT) scans validated porosity values. Thus, a better understanding of the effects of the flow rate in oil recovery on fractured carbonates rocks and the potential of the model developed for this type of studies could be verified.
Online Valve Replacement using Tethered TECNOPLUG on ADNOC Onshore Main Oil Line
Authors: Balakrishna Menon Unnikrishnan , Chandran Jimesh , G Bowie Angus
Published: November 2019

ADNOC Onshore 24" Main Oil Spurline -1 transferring stabilized crude from Buhasa field (BUH) to MP (Mile Point)-21 hub had a defective 24" Gate Valve on the upstream side of Pig Receiver at MP-21.

The Objective was to replace the defective valve with a refurbished 24" Gate Valve with minimum production impact and without the need for depressurizing /draining the entire 35km section of 24" pipeline from BUH to MP-21.

A novel isolation technique using Tethered TECNOPLUG was identified and utilized for successful replacement of the defective upstream valve without causing any impact on the oil production.
LWD Resistivity Tool Response Modeling in High Angle and Horizontal Maximum Reservoir Contact Wells and its Significant Impact on Water Saturation Calculation: Case Study in a Giant Carbonate Field in Middle East
Authors: Yin Hezhu , Nicholis Mike , Al Teneiji Ahmed , Aboud Nawal , Salem Ahmed
Published: November 2019

Resistivity is one of the most important log that is required in water saturation (Sw) calculation, reservoir characterization, field assessment and hydrocarbon production. However, borehole environmental and borehole-to-bedding geometric effects on LWD propagation resistivity logs are inevitable. For instance, severe "polarization horn" responses from LWD propagation resistivity logs are commonly encounted in High-Angle & Horizontal (HAHZ) wells near bed boundaries with high resistivity contrast. These "polarization horns" in LWD propagation resistivity responses in HAHZ wells are not accurate resistivity profile, and consequently, impacts Sw calculation.

In this paper, an innovative LWD propagation resistivity Tool-Response-Modeling (TRM) workflow has been developed and applied to six typical Maximum Reservoir Contact (MRC) wells drilled in a giant carbonate field in Middle East. The inverted resistivity profiles along the well path result in more accurate resistivity and, hence, more accurate Sw calculations (as compared to capillary pressure- and core-based Sw calculations). Additionally, TRM results yield new insights on to both maintain the well in the target formation and reduce these "polarization horn" responses during geosteering operations. The case studies demonstrated that TRM and this workflow has an important and critical roles in accurate Sw calculation, formation evaluation and field assessment, and hydrocarbon production.
Neural Network Assisted Seismic Velocity Editing
Authors: Simha Srungeer , Goudswaard Jeroen , Devarakota Pandu , Somawanshi Prakalp
Published: November 2019

Normal Move-Out (NMO) velocity pick editing is the segregation of good and bad picks from an unsupervised auto-picking algorithm. As not all these picks are correct, manual velocity editing is required. This is time consuming, repetitive and typically requires a seismic expert for days to weeks. Automating it would require an algorithm that mimics the domain knowledge and expertise of a seismic processor; a deterministic approach would therefore likely fail. Alternatively, we propose a machine learning algorithm to identify valid time-velocity picks.

The proposed approach is a supervised classification approach which utilizes human interpreted velocity picks (1-5% of all picks) as training data. The algorithm learns to recognize the features of a valid velocity pick from metadata such as semblance energy, depth, areal location etc. and utilizes said understanding to segregate valid picks from invalid ones (multiples etc.) amongst the remaining velocity picks. The algorithm has been trained using synthetic NMO picks created by finite-difference forward modelling CMP data, including multiples, in the Marmousi model and auto-picking the move-out. The ground-truth NMO picks were created directly from the velocity model.

The trained classification neural network shows a very high > 97% accuracy on segregation of valid and invalid NMO velocity picks based on a 5% input data set. Further reduction of the training data set to 1% of velocity picks reduces test accuracy only by an additional 2 percentage points. Training and execution time of the neural network on a dataset of ~ 40000 velocity picks are also extremely fast (< 5 mins). Initial results on RMO picks also show a very similar performance characteristic.

The metadata for all valid picks spans a multi-dimensional feature space, from which the neural network constructs a non-linear selection criterion. A human can either manually QC each pick or perform attribute-based selection using only lower dimensional linear selection criteria. The robustness and speed of the neural network outperforms the manual editing while also reducing cycle time; the resulting velocity models will be superior, leading to improved signal processing and imaging results further in the processing sequence.

Automating velocity picking and editing has been a research objective for many years now, but only since the availability of modern computation and optimization algorithms can we properly deploy this to augment the high-quality modern velocity picking software and significantly decrease turn-around time by automating the picking and QC process.
Real-Time Monitoring of a Green Digital Oil Field in Abu Dhabi Offshore: It's Benefits and Challenges
Authors: Javid Khalid , Ettireddi Srinivas , Mokhtar Hafez Yahia , Hossni Ali Mohamed , Marin Centurion Pedro Ronaldo , Gonzalez Cerrada Luis Oscar , Mohamed Mohamed Sayed , Zahaf Kamel , Ibrahim Alhosani Khalil , Al Qamzi Abdulla Gharib
Published: November 2019

This Green Field was recently commissioned and it was put on production last year. It is a model Digital Oil Field having two artificial islands built to drill all its wells with smart completions like ICVs, ICDs and Permanent Downhole Gauges in all Oil & Gas Producer Wells. This paper will describe the benefits of real-time data utilization for better and most efficient Field/Wells Monitoring along with Better and quick decision-making. Flow tests are performed 2-3 times a week using Multi phase flow meter (MPFM) for each of its wells.

Smart and Innovative Dashboard have been created for best screening and grouping of wells as per predefined business rules and alerting Asset Engineers for any wells, which are close to violating any of the Reservoir Management Guidelines, and therefore timely decisions, are made to avoid those violations. Miscible Gas Injection was started from the early days of Field life. Gas Tracers are planned to be injected by the end of this year to achieve the successful and improved surveillance and understandingly Reservoirs and better plan the future wells locations and completion strategy.

All Field/well Shut Down duration opportunities are utilized for Pressure Build-up analysis for Oil Producer wells and therefore considerable cost of running Memory gauges and intervention operations is also saved.

Successful Digital Oil Field is a result of collaborative and multiple discipline Team Work. Lessons learned and recommendation for any new Digital Oil Field are also presented in the paper.

Innovative Dashboards have been created to for best screening of wells and alerting for any wells, which are close to violating any of the Reservoir Management Guidelines, and therefore timely decisions, are made to avoid those violations.

The standardized data repository is developed as data integration layer using OSI PI platform products to seamlessly merge real time data with manual data to create a single data reference architecture. This has been a powerful enhancement to ensure a single version of the truth.
Safety Events: Broadening the Base to Increase Learning from Everyday Work With a Look at Return
Authors: Inchingalo Florinda , Capobianco Matteo
Published: November 2019

The term "safety" has become widespread, but since it is a big idea, it may result hard to grasp.

In managing safety, the focus is often on accidents and incidents, however, serious events are infrequent and with them the occasions to learn. Learning focuses on everyday events can take place continuously rather than being a reaction to a single serious event.

The aim has been to raise awareness of all our people and to provide them with tangible measurements of safety in absence of incidents.

In this work it has been detailed a method to quantify monetary returns associated to the continuous identification, analysis and evaluation of risk and relevant controls, based on the fact that management is traditionally focused on financial goals and therefore more inclined to understand such sort of a language.

Thus, it has been considered what a return on investment looks like in safety for transport operations.

Based on evidences collected from our Business Units, a business case was developed where a disruption occurred in the operating activities due to some issues (i.e. downtime, return to base…) that could have been prevented by incurring a particular investment; in other few cases simulations were run based on missed opportunity costs.

Whilst in other domains this tool is quite easy to use, when incorporated into transport safety it becomes much more difficult because of the number of elements that may be affected. Any investment into safety should eventually reduce risk, whether through technology or process improvements with the consequence of reducing post-occurrence expenses.

The cost efficiency of safety management was also confirmed in more quantifiable terms through interviews with logistic managers responsible for decisions on transport management.

With such objective evidence, the budgeting allocation process will be supporting safety as a worthwhile investment, not only in general but also for specific safety measures.
A Novel Empirical Correlation to Predict the Dew Point Pressure using Intelligent Algorithms
Authors: Khan Mohammad Rasheed , Kalam Shams , Tariq Zeeshan , Abdulraheem Abdulazeez
Published: November 2019

Dew point is an important thermodynamic parameter for a gas condensate reservoir and has a very complicated nature due to its reliance on the composition of the mixture. For accurate prediction of this property, it is imperative to develop accurate models that are not computationally expensive. Currently, there exists various methodologies to estimate dew point pressure at various temperatures and hydrocarbon compositions. These methods include equation of states (EOS), analytical methods, and empirical correlations. These methods, however, have limitations in terms of accuracy or computational expense. This paper proposes a new empirical correlation to predict the dew point pressure for gas condensate reservoirs utilizing computational intelligence algorithms, namely Artificial Neural Networks (ANN), Functional Networks (FN), and Support Vector Machines (SVM).

The available data set comprises of dew-point pressure, temperature, component mole fractions (C7+, CH4, N2, CO2, and H2S). This data is divided into two parts to allow for the training and development of the new model and testing/validation phase. For ANN model the weights and bias as well as the neurons in the hidden layer are tuned to result in an optimized model. In the FN model, a number of learning algorithms were tested to reach to the optimum model to get accurate results. For SVM, three main parameters were explored to develop the intelligent model which includes epsilon, kernel parameters and ‘C’.

This study has resulted in the development of an empirical equation that is able to predict the dew point pressure accurately consuming the least amount of computation time. The proposed equation can be applied for a variable range of composition and temperature/ pressure conditions. This is done by incorporating the effect of composition through two equations for normal-boiling point condition as well as the critical-temperature of the mixture. Model accuracy has been validated through a comparative analysis incorporating actual experimental data from various gas-condensate reservoir samples. These data-set includes various published sources and the results of Wilson, Whitson, and EOS.

This work showcases the effectiveness of intelligent models in providing answers with the least amount of error. A comparative analysis for the various computational models is done to come up with a correlation proving accurate results for the dew point pressure. The proposed correlation can predict the output with relatively small errors.
Deterministic Pipe Network Modelling for Fractured Rocks
Authors: Jing Yu , Armstrong Ryan , Mostaghimi Peyman
Published: November 2019

The fracture network plays a critical role in controlling flow pathways in fractured rock. Thus, transmissibility study of fracture networks via different flow modelling methods is of importance. Compared with direct flow simulation, the pipe network model is an effective means of modelling fluid flow in fracture network due to its computational efficiency. However, the characterisation of the fracture network topology as well as the equivalent conductivity of the pipes are still challenging to credibly predict the permeability. Also, pipe network models are commonly constructed based on stochastic Discrete Fracture Network (DFN) models with more uncertainties, which also requires a number of stochastic DFN realisations to be created. In this paper, we develop a novel Pipe Network Modelling (PNM) framework for fractured media, where the PNM is constructed based on deterministic DFN models that are directly derived from micro-CT images. By comparing permeability values obtained from PNMs and results from micro-CT images and voxelised DFNs, we conclude that PNM modelling can effectively estimate the permeability of original fracture networks, while requiring significantly less computational cost. In addition to the advantage of computational efficiency, PNM is more preferable for the challenging multi-phase flow simulation.
Emerging pesticides responsible for suicide in rural Sri Lanka following the 2008-2014 pesticide bans
Authors: Weerasinghe Manjula , Pearson Melissa , Konradsen Flemming , Agampodi Suneth , Sumith J.A. , Jayamanne Shaluka , Senanayake S.M.H.M.K. , Rajapaksha Sandamali , Eddleston Michael
Published: November 2019

BackgroundSri Lanka has reduced its overall suicide rate by 70% over the last two decades through means restriction, through means restriction, through a series of government regulations and bans removing highly hazardous pesticides from agriculture. We aimed to identify the key pesticide(s) now responsible for suicides in rural Sri Lanka to provide data for further pesticide regulation.MethodsWe performed a secondary analysis of data collected prospectively during a cluster randomized controlled trial in the Anuradhapura district of Sri Lanka from 2011-16. The identity of pesticides responsible for suicides were sought from medical or judicial medical notes, coroners’ records, and the person’s family. Trend analysis was done using a regression analysis with curve estimation to identify relative importance of key pesticides. ResultsWe identified 337 suicidal deaths. Among them, the majority 193 (57.3%) were due to ingestion of pesticides while 82 (24.3%) were due to hanging. A specific pesticide was identified in 105 (54.4%) of the pesticide suicides. Ingestion of carbosulfan or profenofos was responsible for 59 (56.2%) of the suicides with a known pesticide and 17.5% of all suicides. The increasing trend of suicides due to carbosulfan and profenofos over time was statistically significant (R square 0.846, F 16.541, p 0.027). ConclusionIngestion of pesticides remains the most important means of suicides in rural Sri Lanka. The pesticides that were once responsible for most pesticide suicides have now been replaced by carbosulfan and profenofos. Their regulation and replacement in agriculture with less hazardous pesticides will further reduce the incidence of both pesticide and overall suicides in rural Sri Lanka.
Towards Developing a Model for the Evaluation of Hospital Disaster Resilience: A Systematic Review
Authors: Aliabadi Saeed Fallah , Ostadtaghizadeh Abbas , Ardalan Ali , Fatemi Farin , Khazaei Bijan , Mirjalili Mohammad Reza
Published: November 2019

Background: Hospitals play a vital role in disaster stricken regions. The resilient hospitals will be able to provide essential services to affected people and it can mitigate the risk of injuries during and after disasters. This study aimed to obtain the indicators required for the evaluation of hospital resilience. Methods: This systematic review was conducted in 2018. Through this systematic review, international electronic databases were investigated for the research studies published in English. The exclusion and inclusion criteria were determined to extract the hospital resilience indicators. These indicators will be used in order to develop a model to keep the system performance at an acceptable level during disasters. Results: Out of 1794 research studies published until September 2018, 89 articles and guidelines with full text were surveyed. Thirty-two articles and guidelines were then selected and analyzed to collect the indicators related to hospital disaster resilience (HDR). The domains and the indicators were extracted from these selected research studies. The authors collected and categorized them into three domains and twenty seven subdomains. The three domains included constructive, infrastructural, and administrative resilience. The relevant indicators were designed for each subdomain to assess HDR. Conclusion : Since diverse indicators affect hospital resilience, other studies should be conducted to propose some models or tools to quantify the hospital resilience in different countries and scopes with an all hazards approach. Key words : Disaster; Hospital; Resilience; Structural and Non-structural Systems; Indicators
Susceptibility of BAFF-var allele carriers to severe SLE with occurrence of lupus nephritis
Authors: Friebus-Kardash Justa , Trendelenburg Marten , Eisenberger Ute , Ribi Camillo , Chizzolini Carlo , Huynh-Do Uyen , Lang Karl Sebastian , Wilde Benjamin , Kribben Andreas , Witzke Oliver , Dolff Sebastian , Hardt Cornelia
Published: November 2019

Background: Dysregulation of the B-cell activating factor (BAFF) system is involved in the pathogenesis of systemic lupus erythematosus (SLE). Increased serum concentrations of BAFF are related to lupus nephritis and disease activity among SLE patients. Recently, a variant of the BAFF-encoding gene, BAFF-var, was identified to be associated with autoimmune diseases, in particular SLE, and to promote the production of soluble BAFF. The present study aimed to assess the prevalence of BAFF-var in a cohort of 195 SLE patients and to analyze the association of the BAFF-var genotype (TNSF13B) with various manifestations of SLE. Methods: A cohort of 195 SLE patients from Central Europe, including 153 patients from the Swiss SLE Cohort Study and 42 patients from the University Hospital Essen, Germany, underwent genotyping for detection of BAFF-var allele. Results: Of the 195 patients, 18 (9.2%) tested positive for BAFF-var variant according to the minor allele frequency of 4.6%. The presence of BAFF-var was associated with the occurrence of lupus nephritis (p=0.038) (p=0.03 and p=0.003). Among various organ manifestations of SLE, the presence of BAFF-var was associated with the occurrence of lupus nephritis (p=0.038; odds ratio [OR], 2.4; 95% confidence interval [CI], 0.89-6.34) and renal activity markers such as proteinuria and hematuria (p=0.03; OR, 2.4; 95% CI, 0.9-6.4 for proteinuria; p=0.003; OR, 3.9; 95% CI, 1.43-10.76 for hematuria). SLE patients carrying the BAFF-var allele exhibited increased disease activity at study entry, as determined by the physician's global assessment (PGA: p=0.002; OR, 4.8; 95% CI, 1.54-14.93) and the SLE Disease Activity Index (p=0.012; OR, 3.5; 95% CI, 1.12-11.18). Consistent with that, the percentage of patients treated with immunosuppressive agents at study entry was higher among those carrying the BAFF-var allele than among those tested negative for BAFF-var (p=0.006; OR, 3.7; 95% CI, 1.27-10.84). Conclusions: Our results indicate an association between the BAFF-var genotype and increased severity of SLE. Determining the BAFF-var status of SLE patients may improve the risk stratification of patients for whom the development of lupus nephritis is more likely and thus may be helpful in the follow-up care and treatment of SLE patients.
Prediction of perioperative outcome after hepatic resection for pediatric patients
Authors: Liu Jianxia , Zhang Yunfei , Zhu Hai , Qiu Lin , guo chunbao
Published: November 2019

Background Hepatic resection is associated with significant risk of morbidity and mortality. Optimising the surgical techniques and perioperative management may improve in operative morbidity and mortality. However, perioperative variables involved in the improvement for postoperative outcomes in pediatric hepatectomy have not been defined.Methods We retrospectively reviewed 156 consecutive pediatric patients who underwent hepatectomy at our center (an academic tertiary care hospital) between 2006 and 2016. Baseline demographic variables, intraoperative variables, complications, and hospital stay were explored. The patients were further investigated using univariate and multivariate analysis for the factors involved in the postoperative outcomes.Results Of the conditions requiring resections, malignant and benign liver diseases accounted for 47.4% (74/156) and 52.6% (82/156), respectively. The overall hospital mortality was 1.9% (3/156) and the overall postoperative complication rate was 44.2% (69/156). Anatomical resections were performed in 128 patients (82.1%), including 14(9.0%) extended hepatectomies. Eighty percent of patients had three or more segments resected. The median operative time was 167.7 (65-600) minutes and median estimated blood loss was 320.1(10-1600) mL. On multivariate analysis, the estimated blood loss (EBL) (mL) (OR, 2.19; 95CI, 1.18-3.13; p=0.016), extent of hepatectomy (OR, 1.81; 95CI, 1.06-2.69; p=0.001) and pringle maneuver (OR, 1.38; 95CI, 1.02-1.88; p=0.038) were the independent predictors of postoperative complications.Conclusions Extent of hepatectomy and estimated blood loss are largely responsible for the perioperative complications. with the surgical devices and management amelioration, like pringle maneuver, the treatment planning may be optimize in pediatric liver resection.
Biomedical Science Knowledge Contributes to the Development of Adaptive Expertise and Formation of a Professional Identity: An Applied Thematic Analysis of Medical Students' Essays
Authors: Dickinson Bonny Lynn , Gibson Kristine , VanDerKolk Kristi , Greene Jeffrey , Rosu Claudia A , Navedo Deborah D , Porter-Stransky Kirsten A , Graves Lisa E
Published: November 2019

Background
Intensive study of the biomedical sciences remains a core component of undergraduate medical education with medical students often completing up to two years of biomedical science training prior to entering clerkships. While it is generally accepted that biomedical science knowledge is essential for clinical practice because it forms the basis of clinical reasoning and decision-making, whether medical students perceive an expanded role for their biomedical science knowledge remains to be examined.

Methods
We conducted an applied thematic analysis to explore how medical students in the first clerkship year perceived the relevance of biomedical science knowledge to clinical medicine during this pivotal time as they begin their transition from students to physicians. To identify previously unidentified perspectives and insights, we asked students to write brief essays in response to the prompt: How is biomedical science knowledge relevant to clinical medicine?

Results
Applied thematic analysis of students’ essays revealed ten codes from which four themes emerged. The analysis revealed novel perspectives previously unidentified by survey studies and focus groups. Specifically, students perceived their biomedical science knowledge as contributory to the development of adaptive expertise and professional identity formation, both viewed as essential developmental milestones for medical students.

Conclusions
The results of this study suggest that biomedical science knowledge contributes to medical students’ acquisition of adaptive expertise and their development of a professional identity. These findings have important implications in the setting of accelerated medical school programs in which training in the biomedical sciences are compressed or truncated. Thus, the contextual factors of the learning environment, including both explicit and tacit elements of the formal, informal, and hidden curriculum, that enable biomedical science knowledge to contribute to these developmental processes need to be identified and studied so that they are leveraged rather than lost during curricular reform.
Effect of Diabetes Mellitus on short-term prognosis of 227 pyogenic liver abscess patients after hospitalization
Authors: Du Zhaoqing , Zhou Xinchen , Zhao Junzhou , Bi Jianbin , Ren Yifan , Zhang Jia , Lin Yuxin , Wu Zheng , lV Yi , Zhang XuFeng , Wu Rongqian
Published: November 2019

Background: Pyogenic liver abscess (PLA) is an inflammatory disease with increasing incidence. When it occurs with diabetes mellitus (DM), risk of recurrence and the mortality may increase. However, the effect of DM on short-term prognosis of PLA patients after hospitalization remained unknown.Methods: 227 PLA patients who received treatment at the First Affiliated Hospital of Xi’an Jiaotong University from January 2011 to January 2018 were retrospectively enrolled. They were divided into two groups as DM group (n=61) and Non-DM group (n=166). In the DM group, HbA1C level <7% was considered to be good-control of glycaemia (n=23). The clinical characteristics and overall short-term survivals were analyzed.Results: The proportion of PLA patients with DM was 26.87%. In the DM group, there was a higher incidence of hypertension and Candida spp. infection. Conservative administration and percutaneous drainage were mainly used in patients with good- (60.87%) and poor-control (60.53%) of glycaemia, respectively. During follow-up, 24 (10.57%) died due to uncontrolled systemic infections and other serious complications. Compared with PLA patients without DM, patients in the DM group had significantly increased 6-month mortality rate after discharge (Log-Rank test, P =0.021). Poor-control of glycaemia did not reduce the six-month survival, while the recurrence rate of PLA within three months showed an almost 3-fold increase (13.16% vs. 4.35%). Further multivariate analyses found that DM was the only independent risk factor for the PLA six-month survival (odd ratio [OR]: 0.097, 95% confidence interval [CI]: 0.018-0.526, P =0.007). However, the blood glucose level had no significant effect on the short-term survival of PLA patients with DM (Log-Rank test, P =0.218).Conclusions: In PLA patients, DM aggravated short-term mortality and blood glucose levels should be well controlled.
The Persistence of Child and Adolescence Mental Healthcare: Results from Registry Data
Authors: Dijk Hermien , Freriks Roel , Alessie Rob , Mierau Jochen
Published: November 2019

Background: Previous studies on the persistence of child and adolescent mental healthcare do not consider the role of time-invariant individual characteristics. Estimating persistence of healthcare using standard linear models yields biased estimates due to unobserved heterogeneity and the autoregressive structure of the model. This study provides estimates of the persistence of child and adolescent mental healthcare taking these statistical issues into account. Methods: We use registry data of more than 80,000 Dutch children and adolescents between 2000 and 2012 from the Psychiatric Case Registry Northern Netherlands (PCR-NN). In order to account for autocorrelation due to the presence of a lagged dependent variable and to distinguish between persistence caused by time-invariant individual characteristics and a direct care effect we use Arellano-Bond estimation. In further analyses we assess the robustness of our results to policy reforms, different definitions of care and diagnosis decomposition. Results: All estimation results for the direct care effect (true state-dependence) show a positive coefficient smaller than unity with a main effect of 0.215 ( p < 0.01), which indicates that the process is stable. Persistence of care is found to be 0.065 ( p < 0:05) higher for females. Additionally, the role of time-invariant characteristics in the persistence of care appears to be large. Further analyses indicate that (1) policy reforms only slightly affected persistence of care, (2) results are robust to different definitions of care and (3) persistence of care does not differ significantly across subgroups. Conclusions: The results indicate that a substantial part of persistence is due to time-invariant individuals characteristics. Additionally, we find that in the absence of further shocks a sudden increase of 10 care contacts in the present year is associated with approximately 3 additional care contacts at some point in the future. This result provides essential information about the necessity of budget increases for future years in the case of exogenous increases in healthcare use.
Identification of major depressive disorder disease-related genes and functional pathways based on system dynamic changes of network connectivity
Authors: Geng Ruijie , Huang Xiao
Published: November 2019

Objective : Major depressive disorder (MDD) is a neurologic disorder, involving complex abnormal biological functions and the neural network. In this study, we aimed to compare different network connectivity of pathological changes of brain tissues under different conditions, and dynamic analyze the biological pathways and genes significantly associated with disease progression, and further to predict potential drug targets.
Methods : Datasets of mRNA expression profiles of samples of postmortem anterior cingulate cortex (ACC) and prefrontal cortex (PFC) from patients with MDD were downloaded from GEO database. We used a method based on system network analysis. Correlation networks based on co-expression were constructed. Topological properties of the networks were analyzed and compared.
Results : Our results showed that the lesions of brain tissues in MDD patients were not synchronized and alterations of biological functions were not consistent either. ACC showed a greater degree of abnormality as compared to PFC suggesting a higher correlation with disease progression. We consequently analyzed the signaling pathways enriched by DEGs and further cross talk genes that bridge the multiple pathways were also identified. Through construction of the pathway-gene complex network, the genes and signaling pathways with top10 degrees were extracted, which are more likely to be the potential novel therapeutic targets. We also mined the drugbank database for the top10 cross talk genes to explore their drugable target potential. The results suggested that CACNA1A, PTDSS2 and CD19 differentially expressed in both ACC and PFC may correlate with depression progression or other cerebral nerve system related diseases, are more likely to become the new drug targets.
Conclusion : Co-expression network and tissue comparing analysis are capable to identify MDD disease related signaling pathways and cross talk genes with potential to be novel drug targets.
Exploring factors of diagnostic delay for patients with bipolar disorder: A population-based cohort study
Authors: Lublóy Ágnes , Lilla Keresztúri Judit , Németh Attila , Mihalicza Péter
Published: November 2019

Background Bipolar disorder if untreated, has severe consequences: widespread role impairment, higher health care costs, mortality and morbidity. Although effective treatment is available, the delay in diagnosis might be as long as 10-15 years. In this study we aim at documenting the length of the diagnostic delay in Hungary and identifying factors associated with it.Methods Kaplan-Meier survival analysis and Cox proportional hazards model was employed to examine factors associated with the time to diagnosis of bipolar disorder measured from the date of the first presentation to any specialist mental healthcare institution. We investigated three types of factors associated with delays to diagnosis: demographic characteristics, clinical predictors and patient pathways. Administrative data was retrieved from specialist care; the population-based cohort includes 8,935 patients from Hungary.Results In the sample, diagnostic delay was 6.46 years on average. The mean age of patients at the time of the first bipolar diagnosis was 43.59 years. 11.85% of patients were diagnosed with bipolar disorder without any delay, and slightly more than one third of the patients (35.10%) were never hospitalized with mental health problems. 88.80% of the patients contacted psychiatric care for the first time in outpatient settings, while 11% in inpatient care. Diagnostic delay was shorter, if patients were diagnosed with bipolar disorder by non-specialist mental health professionals before. In contrast, diagnoses of many psychiatric disorders received after the first contact were coupled with delayed bipolar diagnosis. We found empirical evidence that in both outpatient and inpatient care prior diagnoses of schizophrenia, unipolar depression without psychotic symptoms, and several disorders of adult personality were associated with increased diagnostic delay. Patient pathways played an important role as well: the hazard of delayed diagnosis increased if patients consulted mental healthcare specialists in outpatient care first or they were hospitalized.Conclusions We systematically described and analysed the diagnosis of bipolar patients in Hungary controlling for possible confounders. Our focus was more on clinical variables as opposed to factors controllable by policy-makers. To formulate policy-relevant recommendations, a more detailed analysis of care pathways and continuity is needed.
Non-interventional retrospective study to evaluate menstrual bleeding profiles, tolerability and quality of life of women using the new vaginal ring Ornibel® delivering etonogestrel 0.120 mg and ethinylestradiol (EE) 0.015 mg per day
Authors: REGIDOR PEDRO ANTONIO , Sailer Manuela , Colli Enrico , Calvo Enrique , Palacios Santiago , Roemer Thomas
Published: November 2019

Background: To assess the menstrual cycle profile, tolerability, quality of life and sexual wellbeing in women using the vaginal contraceptive ring Ornibel®. Method: Non-interventional, retrospective, multi-center study on 103 women between 18 and 45 years old that used Ornibel® for at least 6 months. Menstrual cycle characteristics, vaginal infections and quality of life parameters were analyzed. Change in menstrual bleeding profiles and menstrual bleeding associated pain were assessed via visual analogue scales (VAS). Results: Menstrual flow and dysmenorrhea reduced significantly. The VAS score reductions were 16 and 22,5 points respectively (p < 0.001). No differences were observed between women that changed from another contraceptive method to the vaginal ring. The percentage of women without unscheduled bleedings or spotting increased from 79% to 88%. The percentage of women with unscheduled bleeding or spotting significantly decreased from 21% to 12%. Women rated the ring as very comfortable or comfortable (97%) as well as easy to insert (91%). The continuation of the usage of the ring and a recommendation for the ring were significantly associated with these two parameters. Conclusions: Ornibel® improved the menstrual cycle profile, reduced dysmenorrhea and shows a very high adherence to the use. Clinical trial register: DRKS-ID: DRKS00014982
MicroRNA-99a promotes cell proliferation, migration and invasion in gastric cancer by modulating c-Src
Authors: Pan Yue , Chen Weixing , Yuan Xin , Lu Hongpeng , Xu Lei , Li Peifei
Published: November 2019

Background: Recent studies have shown that microRNA-99a(miR-99a)plays a key role in the development of virious malignancies; however, its relationship with gastric cancer remains unclear. In this study, we investigated the functions and potential mechanisms of miR-99a in gastric cancer. Methods: Real-time qRT-PCR was used to assess the expression levels of miR-99a in gastric cancer tissue samples and cell lines compared to their matched adjacent normal tissues and a normal gastric mucosa epithelial cell line, respectively. SGC-7901 cells were transfected with miR-99a mimics and negative controls to determine the effects of miR-99a overexpression on cell proliferation, cell cycle transition, migration and invasion of gastric cancer cells in vitro . The role of miR-99a in endogenous c-Src expression in gastric cancer cells was also investigated by qRT-PCR and Western blotting. Results: Our results showed a significant increase in miR-99a expression in both gastric cancer tissues and cells compared to normal tissues and cells. Overexpression of miR-99a significantly promoted the cell proliferation, migration and invasion of gastric cancer cells compared to normal cells, with a concurrent increase in the S+G2 phases of the cell cycle. Further investigations found that miR-99a overexpression led to significant upregulation of endogenous c-Src. Conclusion: Taken together, our findings suggest that miR-99a may act as a tumour promoter in the pathogenesis of gastric cancer by indirectly modulating c-Src expression.
Tuberculosis treatment results in Western Iran over the past 13 years
Authors: Soofi Moslem , moradi atefeh , Riyahi Parisa , Rezaei Sholeh , Shakiba Ebrahim , Moradinazar Mehdi
Published: November 2019

Introduction Tuberculosis is one of Iran's most significant infectious diseases, which with the advent of new and chronic diseases, is still known as the most threatening disease of human community. The goal of this research was to assess the result of TB treatment in western Iran (province of Kermanshah) and its associated factors during 2005 to 2017.Method In this cross-sectional study, all patients who had tuberculosis from 2005 to the end of 2017 were evaluated. Treatment outcomes were categorized into four domains of “treatment completion," “death," “treatment failure," and “recoveries" based on national guidelines, and factors affecting outcome were identified using univariate and multivariate logistic regression.Results Tuberculosis incidence was 15.21 in males and 14.32 in females per 100,000 individuals. The therapy result was almost uniform during the years investigated. 32.2% had extra pulmonary TB; 58.7% completed treatment; 9.9% died, and 4.1% had treatment failure. After controlling for key factors, the odds of completion of therapy in females were 1.1 (1.0-1.3) times greater than in males, and therapy failure and mortality caused by tuberculosis were also smaller in females than in males 0.6(0.4-0.8) and 0.5(0.3-0.7) respectively). HIV was the greatest variable in the prevalence of tuberculosis with 9.5 (5.8–16.8) times greater chances of death in HIV-positive people than those without HIV.Conclusion Given the high prevalence of pulmonary tuberculosis and public health concerns, early screening and infection diagnosis, education and protective measures are suggested to prevent tuberculosis patients.
Impact of invasive species on the density and body size of an insular endemic lizard (Trachylepis atlantica)
Authors: Gasparotto Vinícius Peron de Oliveira , Micheletti Tatiane , Mangini Paulo Rogério , Dias Ricardo Augusto
Published: November 2019

BackgroundInvasive species have been responsible for the extinction of several species around the world. The Noronha skink is an endemic lizard from the Fernando de Noronha archipelago, Brazil, that has been suffering from habitat changes and the introduction of invasive species. ResultsTwo methods were used to estimate the density of the Noronha skink. The density on the main island was 0.167 ± 0.090 individuals/m²; that on the secondary islands was 0.357 ± 0.170 individuals/m²; and that on the entire archipelago was 0.184 ± 0.109 individuals/m². Moreover, the morphometric parameters of the Noronha skink were compared between the main island and secondary islands. The values of all parameters were higher on the secondary islands. ConclusionThe occurrence of invasive species on the main island seems to be a determining factor in the density and body size of the Noronha skink.