bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compositional Changes in Athabasca Bitumen During Air Injection into Mature SAGD Chambers - Observations from 3-D Large Scale Experiments
Authors: Sequera-Dalton Belenitza M. , Aminfar Ehsan , Moore Robert G. , Mehta Sudarshan A. , Ursenbach Matthew G. 
Published: September 2020

Abstract
Air injection into mature SAGD chambers is a promising method to sustain steam chamber pressures while reducing steam-to-oil-ratios (SOR) and increasing oil production in SAGD late life. The feasibility of attaining and sustaining a high temperature combustion front when injecting air into a steam chamber has been recently demonstrated with a three-dimensional (3-D) large scale experiment. In order to effectively mobilize bitumen, bond scission reactions are required to occur between the injected oxygen and the bitumen. The highly effective combustion process is accompanied by thermal cracking reactions which often produce lighter oil fractions and coke. However, low temperature oxidation reactions or oxygen addition to the bitumen may occur if oxygen rates are not sufficient to sustain the combustion front which in turn could degrade the bitumen properties. This paper focuses on the compositional changes observed on Athabasca bitumen during air injection after SAGD in a 3-D large scale experiment. Changes in bitumen properties, as measured from produced and residual oil samples, such as density, viscosity, asphaltenes content and hydrocarbon cut point distribution are presented.
The well configuration in the 3-D experiment consisted of two well-pairs located near the bottom corners of the rectangular model. At the end of the SAGD period, air was injected into one of the injection wells while fluids were produced from both wells in the well-pair located on the other end of the model. Oil properties from produced liquid samples, captured from the upper and lower production wells during the test, as well as extracted oil from selected post-test core samples were analysed and correlated with time and their location in the 3-D model, respectively.
Fluid segregation and distinctive fluid properties were observed in the samples produced from the upper and lower producer wells. A significant portion of produced oil samples exhibited lower density, viscosity and asphaltenes content than the original bitumen indicating that oil upgrading took place during the test. Post-test core samples were analysed during the excavation or unpacking of the 3-D model and their weights, visual appearance and 3-D location were recorded. Properties of oil extracted from selected post-test core samples also indicated the presence of upgraded oil in the residual hydrocarbons. The asphaltenes content in selected residual oil samples remained similar to that of the original oil.
Significant amounts of upgraded oil produced during the 3-D experiments highlights the potential added benefits of air injection into mature SAGD chambers.
Theory and Implementation of an Approximate Physics Simulator for Heavy Oil Production Forecasting
Authors: Dehdari Vahid , Deutsch Clayton V. 
Published: September 2020

Abstract
Oil sand reservoirs play an important role in the economy of Canada due to their significant recoverable reserves. Due to the high viscosity of the oil in these reservoirs, conventional methods cannot be used for production. The steam-assisted gravity drainage (SAGD) method is an efficient way of producing oil from these reservoirs. Predicting oil production and steam injection rates is required for planning and managing a SAGD operation. This can be done by simulating the fluid flow with flow simulation codes, but this is very time consuming. The run time for a 3D heterogeneous model with one well pair can exceed 2 days. In this paper, a SAGD approximate simulator for predicting SAGD performance with 3D heterogeneous models of geologic properties is developed. This approximate simulator can handle different types of operating strategies. The approach is an approximate solution using a semi analytical model based on relevant theories including Butler's SAGD theory. The approximate simulator or proxy is much faster than the full simulator and it gives accurate estimated oil production and steam injection rates at different time steps. Theoretical and numerical research has been undertaken to develop the proxy, implement it in fast code, demonstrate the accuracy of prediction and apply to realistic examples. This proxy is used for other applications such as transferring uncertainty for reservoir realizations and well trajectory optimization.
A New Criterion for the Estimate of Impact of Lean Zones on the Performance of SAGD/SA-SAGD/EBRT Processes
Authors: Liu Zhihong , Khaledi Rahman , Farshidi Sara Forough , Wattenbarger Chick 
Published: September 2020

Abstract
This paper proposes a new criterion to estimate the impact of lean zones on thermal or thermal-solvent processes, such as SAGD, SA-SAGD, or EBRT (Imperial Oil's "Enhanced Bitumen Recovery Technology"). The interface stability of the steam/solvent chamber in the lean zone is related to the competition of heat transfer in either conductive or convective forms. This competition is described by a non-dimensional number, the Rayleigh number in porous media, which can be calculated by the parameters of the lean zone thickness, water mobility, thermal diffusivity, and steam chamber temperature. When a system's Rayleigh number is larger than a critical value, the primary heat transfer mechanism in the lean zone will be convection, in which the interface becomes unstable and may cause significant loss of steam or solvent. Analytical solution to obtain the critical Rayleigh number was given in literature (Philip, 1982). For long axis horizontal cross sections, the critical Rayleigh number is estimated between 0.1 and 1. A significant number of simulation cases have been analyzed in a sensitivity study with CMOST (Computer assisted Matching, Optimization, and Sensitivity analysis Tool, Computer Modeling Group) to validate the above hypothesis. Monte Carlo simulation results have shown a strong correlation between the solvent recovery and the product of water mobility and lean zone thickness. This product is the essential part of the formula of modified Rayleigh number. Further calculation indicated that the critical Rayleigh number for the simulation models is between 0.1 ∼ 1 for SA-SAGD or SAGD and about 0.17 ∼ 0.32 for EBRT. Both are within the range given by the analytical solution. The critical Rayleigh number is introduced to the lean zone analysis for the first time. This physics-based criterion is able to give an answer to the estimate of performance impact of the lean zone for thermal and thermal-solvent gravity drainage processes. The Monte Carlo simulation confirmed the consistency between the numerical studies and the analytical solution.
Analytical and Numerical Modeling of In-Situ Reflux ISR for Optimizing Oil Sands Development
Authors: Mohammad Zeidani , Asghar Sadeghi Boogar , Zhangxing John Chen 
Published: September 2020

Abstract
In-Situ Reflex (ISR) is a novel solvent-based process that utilizes resistive electric heaters to vaporize solvent and recycle mobilized water downhole. ISR promises a significant reduction in greenhouse gases emissions through the elimination of steam generation and water handling facilities at the surface as well as effectively vaporizes the injected fluid along a wellbore. However, the economic viability of this process is highly dependent on the in-situ refluxing of the solvent which requires an in-depth understanding of the process and associated challenges numerically and analytically. In modeling the SAGD process, optimal operating conditions rely on a relatively constant temperature profile across the major portion of a steam chamber that leads to an excessive energy input requirement. However, ISR optimal operating conditions tend to exhibit different temperature profiles as a result of changing thermal recovery to a solvent diluting mechanism. As such, employing a SAGD analytical model results in misunderstanding the ISR fundamental thermodynamics and hindering further optimization of the process.
This paper is the first time that an unsteady-state semi-analytical model has been developed for predicting ISR performance and shared publicly. The developed model has been validated using numerical simulation data and is capable of properly predicting a temperature distribution in a steam-solvent gaseous chamber in the presence of a fixed source of heat in an injector. This model includes fixed heat sources in both injectors and producers to represent the resistive heater concept, capture the reflux concept, and evaluate the contribution of refluxed solvent to reducing the solvent usage. In addition, the model helps better understand the phase behavior and the effectiveness of various solvents in further analyzing and determining the optimum downhole operating conditions and improving the overall ISR performance and its economic viability.
The proposed model brings an insight into analytical modeling of the ISR process with the aim of increasing an understanding of the heat transfer mechanism, along with identifying the advantages and limitations of using the bottom-hole resistive heater technology. This will lead to a higher predictability of successful field implementation, lower upfront capital cost, higher energy efficiency, and environmentally sustainable development.
The Effect of Solvent based Nanofluid Flooding on Heavy Oil Recovery
Authors: Maaref Sepideh , Kantzas Apostolos , Bryant Steven L. 
Published: September 2020

Abstract
The objective of this study is to investigate the effect of solvent based nanofluid flooding followed by waterflooding on heavy oil recovery performance and sweep efficiency improvement in unconsolidated oil-wet porous media. The sweep efficiency improvement is correlated with in-situ emulsion generation during such displacement and is monitored with a CT scanner.
Partially hydrophobic silica NPs with proper interface affinity was firstly synthesized, and subsequently dispersed in toluene along with a surfactant to prepare the solvent based nanofluid. The solvent based nanofluid was then injected into an oil saturated sandpack at different slug sizes and further chased by brine to investigate the sweep efficiency improvement through possible emulsification. To investigate the beneficial effect of NPs, the aforementioned flooding was compared against conventional solvent flooding followed by waterflooding. The displacement patterns were monitored with a CT-scanner to assess the heavy oil recovery performance in the absence or presence of the solvent based nanofluid.
The fluid density profiles during solvent based NF flooding followed by waterflooding were extracted from CT-scan images and compared against conventional solvent flooding followed by waterflooding to assess potential sweep efficiency improvement. The results revealed an increase in sweep efficiency during solvent based NF flooding followed by waterflooding. This was related to the creation of in-situ emulsion at the water-diluted oil interface due to the presence of NPs and surfactant in diluted oil. Unlike conventional solvent flooding where post water created several fingers through porous media, the water phase in solvent based nanofluid flooding was able to displace all the lower resistance paths created by the solvent based nanofluid. Moreover, chase water was able to recover almost all of the solvent in solvent based NF flooding, which is essential for the process to be economically viable. In general, the presence of solvent based NF was found to be effective in re- distributing the preferential water flow paths in to a more uniform front, which suppressed the fingering in turn and resulted in later water breakthrough, better sweep efficiency, and higher oil recovery.
The proposed solvent based nanofluid flooding has not been tested so far as a heavy oil recovery technique. Unlike conventional solvent flooding which can suffer from high residual solvent to waterflooding, this technique revealed negligible residual solvent upon waterflooding. Moreover, it was found to be effective in sweep efficiency improvement and heavy oil recovery compared to conventional solvent flooding.
Factors Associated with Receipt of Mammogram among Caregivers: A Comparison with Non-Caregivers
Authors: Kim Soo Young , Guo Yuqi , Won Chorong , Lee Hee Yun 
Published: September 2020

Abstract
Background: caregiving responsibilities significantly impact females’ decisions on adhering to preventive mammography. The purpose of this study is to examine (1) the levels of mammogram receipt, (2) the role of caregiving factors on the receipt of mammogram in caregiving group, and (3) the role of cancer beliefs on mammogram screening in caregivers and non-caregivers.Methods: the 2017 Health Information National Trends Survey (HINTS) provides samples of 1228 women aged 40 to 75 years old for this secondary analysis. By using Andersen’s Behavioral Model of Health Services Use, a binomial logistic regression model was used to analyze associations between mammography and socioeconomic factors, caregiving factors, and cancer belief factors. Results: caregivers who provided more caregiving hours per week (OR=0.749, 95% CI=0.564-0.94) and caregivers who had the belief of rather not knowing the likelihood of getting cancer (OR=0.673, 95% CI=0.496-0.914) were less likely to use mammogram. However, caregivers who believed cancer is more common than heart disease (OR=1.490, 95% CI=1.302- 2.151) were more likely to use a mammogram. Non-caregivers who worried about getting cancer (OR=1.158, 95% CI=0.793-1.691) were more likely to use mammogram, but non-caregivers who had the belief of rather not know the likelihood of getting cancer (OR=0.825, 95% CI=0.713-0.955) were less likely to use mammogram.Conclusions: to support caregivers’ breast cancer prevention, caregiving-related policies based on caregiving hours should be developed. Particularly, effort to promote breast cancer screening education and care support among older primary caregivers will likely increase their adherence to preventive mammography uptake. The development of targeted cancer prevention interventions on specific cancer beliefs held by both groups are also urgently needed to promote mammography.
High-Throughput Sequencing Identification of Differentially Expressed microRNAs in Metastatic Ovarian Cancer with experimental validations
Authors: Gu Yang , Zhang Shulan 
Published: September 2020

Abstract
Background: Ovarian cancer (OC) is a common gynecological cancer and characterized by high metastatic potential. MicroRNAs (miRNAs, miRs) have the promise to be harnessed as prognostic and therapeutic biomarkers for OC. Herein, we sought to identify differentially expressed miRNAs and mRNAs in metastatic OC, and to validate them with functional experiments. Methods: Differentially expressed miRNAs and miRNAs were screened from six pairs of primary OC tissues and metastatic tissues using an miRStar™ Human Cancer Focus miRNA & Target mRNA PCR Array. Then, gene expression profiling results were verified by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot assays. The binding affinity between miR-7-5p and TGFβ2 was validated by dual-luciferase reporter assay. Expression of miR-7-5p and TGFβ2 was manipulated to assess their roles in malignant phenotypes of highly metastatic HO-8910PM cells. Results: MiRNA profiling and sequencing identified 12 miRNAs and 10 mRNAs that were differentially expressed in metastatic tissues. Gene ontology and Pathway analyses determined that 3 differentially expressed mRNAs (ITGB3, TGFβ2 and TNC) were related to OC metastasis. The results of RT-qPCR confirmed that the decrease of miR-7-5p was most significant in OC metastasis, while TGFβ2 was up-regulated in OC metastasis. Moreover, miR-7-5p targeted and negatively regulated TGFβ2. MiR-7-5p overexpression accelerated HO-8910PM cell viability and invasion, and TGFβ2 overexpression reversed the results. Meanwhile, simultaneous miR-7-5p and TGFβ2 overexpression rescued the cell activities. Conclusions: This study characterizes differentially expressed miRNAs and mRNAs in metastatic OC, where miR-7-5p and its downstream target were most closely associated with metastatic OC. Overexpression of miR-7-5p targets and inhibits TGFβ2 expression, thereby inhibiting the growth and metastasis of OC.
Can virtual reality improve traditional anatomy educational programmes?A mixed-methods study on the use of a 3D skull model
Authors: Chen Shi , Zhu Jiawei , Cheng Cheng , Pan Zhouxian , Liu Lingshan , Du Jianhua , Shen Xinhua , Shen Zhen , Zhu Huijuan , Liu Jihai , Yang Hua , Ma Chao , Pan Hui 
Published: September 2020

Abstract
Background: Realistic, portable, and scalable lectures, cadaveric models, 2D atlases and computer simulations are being combined more frequently for teaching anatomy, which result in major increases in user satisfaction. However, although digital simulations may be more portable, interesting, or motivating than traditional teaching tools, whether they are superior in terms of student learning remain unclear. This paper presents a study in which the educational effectiveness of a virtual reality (VR) skull model is compared with that of cadaveric skulls and atlases. The aim of this study was to compare the results of teaching with VR to results of teaching with traditional teaching methods by administering objective questionnaires and perception surveys. Methods: A mixed-methods study with 73 medical students was conducted with three different groups, namely, the VR group (N=25), cadaver group (N=25) and atlas group (N=23). Anatomical structures were taught through an introductory lecture and model-based learning. All students completed the pre- and post-intervention tests, which comprised a theory test and an identification test. The theory test consisted of 18 multiple-choice questions, and the identification test consisted of 25 fill-in-the-blank questions. Results: The participants in all three groups had significantly higher total scores on the post-intervention test than on the pre-intervention test; the post-intervention test score in the VR group was not statistically significantly higher than the post-intervention test score of the other groups (VR: 30 [IQR: 22-33.5], cadaver: 26 [IQR: 20-31.5], atlas: 28[IQR: 20-33]; p>0.05). The participants in the VR and cadaver groups provided more positive feedback on their learning models than the atlas group (VR: 26 [IQR: 19-30], cadaver: 25 [IQR: 19.5-29.5], atlas: 12 [IQR: 9-20]; p<0.001). Conclusions: The skull virtual learning resource (VLR) was equally efficient as the cadaver skull and atlas in teaching anatomy structures. Such a model can aid individuals in understanding complex anatomical structures with a higher level of motivation and tolerable adverse effects.
Public awareness and knowledge of factors associated with dementia in China
Authors: Zheng Yong-bo , Shi Le , Gong Yi-Miao , Wang Xiao-Xiao , Lu Qing-Dong , Que Jian-Yu , Khan Muhammad Zahid , Bao Yan-Ping , Lu Lin 
Published: September 2020

Abstract
Background: Dementia is a global public health priority. Many modifiable factors have been shown to influence the development of dementia, but these factors are not adequately known by the general public. This study aimed to assess public awareness of the factors that are associated with dementia in China.Methods: A cross-sectional study was conducted from May to October 2019 using an Internet-based questionnaire. Data on basic sociodemographic characteristics were collected, and the knowledge of risk and protective factors for dementia was investigated. Logistic regression analysis was performed to compare levels of the knowledge of factors associated with dementia across populations with different demographic characteristics.Results: Data from 3,338 respondents were analyzed. The percentages of participants who accurately identified the risk factors of dementia were follows: 84.24% for negative affect, 65.07% for alcohol use, 56.68% for smoking, 48.74% for hypertension, and 42.66% for diabetes. The percentages of participants who accurately identified the protective factors for dementia were follows: 90.00% for exercise, 84.69% for social activity, 80.92% for intelligence games, 74.45% for reading, and 6.14% for antihypertensive or hypolipidemic drugs. The majority of Chinese people correctly recognized the role of lifestyle factors in the development of dementia but not medical factors. The levels of knowledge of the factors associated with dementia were significantly distinct across populations with different characteristics. The following sociodemographic characteristics were associated with more comprehensive knowledge of dementia risk and protective factors: women, young age, high education levels, nonmanual jobs, and contact with patients with dementia.Conclusions: Public awareness and knowledge of risk and protective factors for dementia in China are still insufficient. More efforts are needed to publicize information to reduce the risk of dementia.
JARID1B promotes colorectal cancer proliferation and Wnt/β-catenin signaling via decreasing CDX2 level
Authors: Huang Da , Xiao Fan , Hao Haibin , Hua Fuzhou , Luo Zhenzhong , Huang Zhaoxia , Li Qing , Chen Sha , Cheng Xiuzhi , Zhang Xinyue , Fang Weilan , Hu Xiaoyun , Liu Fanrong 
Published: September 2020

Abstract
Background: Jumonji AT-rich interactive domain 1B(JARID1B) has been shown to be upregulated in many human cancers and plays a critical role in the development of cancers cells. Nevertheless, its functional role in colorectal cancer (CRC) progression is not fully understood.Methods: Herein, JARID1B expression levels were detected in clinical CRC samples by western blotting and qRT-PCR. DLD-1 cells with JARID1B knockdown or overexpression by stably transfected plasmids were used in vitro and in vivo study. Colony formation, 5-ethynyl-20-deoxyuridine (EdU) and Real Time Cellular Analysis(RTCA) assays were used to detect cell proliferation and growth. Transcriptome and CHIP assays were used to examine the molecular biology changes and molecular interaction in these cells. Nude mice was utilized to study the correlation of JARID1B and tumor growth in vivo.Results: Here, we first observed that JARID1B was significantly upregulated in CRC tissue compared to adjacent normal tissues. In CRC patients, JARID1B high expression was positively relation with poor overall survival. Multivariate analyses revealed that high JARID1B expression was an independent predictive marker for the poor prognosis of CRC. In addition, we found that JARID1B promoted CRC cells proliferation by Wnt/β-catenin signaling pathway. Further studies demonstrated CDX2 as a downstream target of JARID1B, and our data demonstrated that CDX2 is crucial for JARID1B -mediated Wnt/β-catenin signaling pathway. Mechanistically, we demonstrated that JARID1B regulated CDX2 expression through demethylation of H3K4me3.Conclusions: CDX2 inhibited by JARID1B-derived H3K4me3 methylation promoted cells proliferation of CRC via Wnt/β-catenin signaling pathway. Therefore, our studies provided a novel insight into the role of JARID1B in CRC cells proliferation and potential new molecular target for treating CRC.