bluuebunny/crossref_metadata_2025 huggingface dataset:
Leveraging Integrated Production Modeling and Digital Platforms to Maximize Liquid Yield and Reduce OPEX from Liquid-Rich Marcellus Reservoirs – A Field Study
Authors: Kumar Hemant , Bhinde Tej , Dias Edgar , Billiter Travis
Published: October 2020

This work describes the use of integrated production modeling (IPM), along with digital platforms, as reliable tools to increase liquid yield, reduce operational expenditures ($/BOE) and maximize the project's net present value (NPV) in the Appalachian Basin. The results of the work, as applied to a real field show that the liquid yield for the gas condensate produced fluids can be increased by 3-5%; compression energy and process heating requirements can be reduced significantly.

The condensate to gas ratio (CGR) in Marshall County, West Virginia (WV) changes rapidly from southeast to northwest. For example, on a single pad (8-10 wells) the CGR of the northwestern wells is ~40% higher than the CGR of southeastern wells. Moreover, the CGR decreases with production time. A fixed-pressure, two-stage separation process is suboptimal for this area. Calibrated physics-based models leveraged to an integration platform can significantly improve the facilities performance.

The facilities set up is as follows: the gas produced from a well is fed to a line heater followed by a surface choke. The fluid then enters a gas processing unit (GPU) separator. The separated fluids from each well's GPU in the well pad are processed at common facilities consisting of separation and compression. The processed gas is exported to a sales gas line and the liquids are transported separately.

A fully integrated model has been built for eight wells on a pad. The reservoir and well models were history matched and then integrated with the surface network and facilities (compressor, heater) using network modeling and integration platforms. Various scenarios were run to identify the optimal pressure setting for a given month. The optimization exercise yielded 5-10% additional natural gas Liquids (NGLs) on a pad by increasing the GPU pressures by 100-200 psi. The higher GPU pressures reduced the well choke pressure drop, thereby reducing the heating requirements by 50% as the Joule-Thomson cooling across the choke was minimized. The reduced cooling also minimized flow assurance risks due to hydrate formation and reduced inhibitor injection costs. Finally, the compression energy requirement was reduced via better management of the pressure staging.

The developed integrated models, combined with digital platforms, offer novel and versatile capabilities for efficiently operating an asset to maximize liquids and reduce operational expenditure (OPEX). The deployment of a physical model-based digital oil field will facilitate the validation of these models on a continuous basis. This in turn will allow changes to be made in the field to keep the system optimized as the characteristics of the producing fluids change with time.
Surfactant-Aided Low-Salinity Waterflooding for Low Temperature Carbonates
Authors: Shi Yue , Miller Chammi , Mohanty Kishore
Published: October 2020

Carbonate reservoirs tend to be oil-wet/mixed-wet and heterogeneous due to mineralogy and diagenesis. Some carbonate reservoirs are fractured especially dolomite formations. The objective of this study is to improve oil recovery in low-temperature dolomite reservoirs using low salinity and surfactant aided spontaneous imbibition. The low salinity brine composition was optimized using zeta potential, contact angle experiments, and wettability index calculations. Significant surface reactions on dolomite rocks were observed at the salinity of 2500 ppm. Thirty-seven surfactants were evaluated for wettability alterations using contact angles. Surfactants with lower IFT and lower contact angles were selected for spontaneous imbibition. In spontaneous imbibition experiments, some formulations produced a significant amount of oil compared to the control samples without any surfactants. Two cationic surfactants produced 41-53% of OOIP and an AOS anionic surfactant produced 39% of OOIP in a month. These experiments demonstrated that a combination of low water salinity and surfactants can make the originally oil-wet dolomite rocks more water-wet and improve oil recovery by imbibition at a low temperature of 35 °C.
Rise of Machines: Time to Change the Petroleum Engineering Curriculum
Authors: Samuel Robello
Published: October 2020

The model of "learn at school" and "do at work" is outdated and must keep up with the changing environment of the Industrial Revolution 4.0 (IR 4.0). The petroleum engineering curricula, therefore, must also change accordingly and this change is needed at a time the new generation of students entering the workforce is different from the generation leaving the workforce. It is time to examine the core curricula being taught at petroleum schools so that long-term sustainability can be established. The petroleum education has been modified very little in the past 30 years and needs to change in the post-Google era to cater to the tech-savvy minds of the modern student. Although developments in technology have positively responded to the needs of the industry in the past, its future advancement will include areas such as telemetry, sensors and data handling, and analytics. Thus, a new approach to engineering education, involving the fundamentals of engineering sciences that culminates in the development of experiential learning on cyber-physical systems, is important. The paper presents and lays out the urgent need for a new type of curriculum for petroleum engineering education that encompasses engineering, science, and technology.
Network Optimization Models at Greater Kuparuk Area Using Neural Networks and Genetic Algorithms
Authors: Murray Rodney L. , Hopkins Reese S. , Valentine Douglas K.
Published: October 2020

The Greater Kuparuk Area, located on the North Slope of Alaska, began production in 1981 and has produced over 2.5 billion barrels to date. The area contains six oil fields flowing into three central processing facilities with 47 drillsites and over 1,200 production and injection wells. The facilities are primarily gas constrained due to limits from the gas lift compressors, and secondarily water constrained due to injection pump capacity. An optimization program using the equal slope concept is currently in use for lift gas allocation. A previous attempt to more rigorously optimize the production system using commercial software resulted in better lift gas allocation, but computation time lead to the cessation of its use for daily optimization.

The objective of this work was to develop a fast, flexible optimization model that recommends well status, lift gas rates, and water injection rates. The model uses field data and data generated by the previous surface models to develop the hydraulic models as well as current facility conditions and constraints. The model contains four components. The first was a function that estimates producer and injector performance. The second is a function that gathers and interpolates well performance models with physics-based models. Third, the drillsite header pressures were estimated using a neural network. Finally, a genetic algorithm is used to search for the optimal well status, lift gas rate, and water injection rate for each well. Connections were made to databases to run the model using field conditions at any time over the last five years.

The hydraulic model for three phase flow utilizes a neural network, whereas a simpler linear based model is used for the water injection system. The hydraulic model was rigorously back tested using field data over a two-year period with weekly model retraining. Drillsite header pressures deviated 6 psi on average from actuals, which is on par with commercial software. The optimization converges in under 90 seconds in a single facility optimization run. The recommendations from the optimization program are expected to increase oil rate 1.5% in the existing system.

While production optimization using genetic algorithms and neural networks has been presented for over 20 years, there are not many, if any, known industry applications of optimizing the production and injection networks simultaneously using neural network models. The program was written in Python and deployed on cloud computing. The tool is used to calculate daily net oil benefit per well, prioritize shut-in wells when the facility is constrained, and optimize injection pumps and drillsite configurations. Additionally, the model is designed to accept new engineer-specified source wells to understand the impact of backout when developing new projects. Overall, the model has provided a platform for engineers to make optimization decisions in a complex, interdependent system.
Exploiting the Full Potential in Automated Drilling Control by Increased Data Exchange and Multi Disciplinary Collaboration
Authors: Gjerstad Kristian , Bergerud Ronny , Thorsen Stig Tore
Published: October 2020

The drive for cost efficient solutions in drilling has become stronger the last few years, and one of the approaches to this end is to increase the level of automation. Automation is multi-disciplinary task, and to really succeed, there is a need for collaboration between the different parties in the drilling industry. In this paper we discuss which underlaying technologies within instrumentation, control systems and communication technology that should be in place for a typical model-based automation and well protection software to work optimal. We elaborate on what is needed to take out the full potential of performance-enhancing functionalities in automated drilling control software. We highlight the gaps present today and how this affects the automation efforts as a whole. The discussion shows that there are some low-hanging fruits that can give significant cost reduction and improvements in automation and safety, while there are also some technology gaps that will take some time to fill and that require coordinated efforts between the vendors.
Significance of Incorporating Water-Wet Regions for Modeling Low Salinity Waterflood in Oil-Wet Carbonates
Authors: Sharma Himanshu , Mohanty Kishore
Published: October 2020

Recent studies have shown that low salinity waterflood can recover additional oil from oil-wet carbonate reservoirs by altering their wettability. Further studies have investigated key mechanisms for wettability alteration, such as, interaction of sulfate ions with organic acids, importance of divalent cations, role of oil acid/base content. The progress, however, has been limited in terms of modeling the wettability alteration process. A few recent studies have reported mechanistic models based on surface-complexation reactions. However, these models have their limitations when applied to oil-wet reservoirs because the injected brine is assumed to interact with the entire rock surface. In reality, the surface reactions occurs in the water-wet regions and the water-wet regions increase as a result of wettability alteration. In this study, a multiphase multicomponent finite-difference reservoir simulator was developed, incorporating the change in oil-wet/water-wet rock fractions, for modeling low salinity waterflood in carbonates. The wettability alteration process was modeled by incorporating key surface-complexation reactions. Single-phase and oil recovery coreflood simulations were performed in which modified brines, such as seawater and diluted seawater, were injected. The simulation results show that the extent of reactions of low salinity brines is much less when these reactions are assumed to take place only in the water-wet regions of oil-wet rocks. Single-phase simulation results agreed well with sulfate delay and dolomitization reactions observed experimentally. Oil recovery simulation results showed reasonable agreement with coreflood results of low salinity water injection reported in the literature. In these simulations, the water-wet rock fraction evolved as a result of wettability alteration on injecting diluted seawater. Simulating geochemical reactions only on the water-wet regions is critical for modeling low salinity waterfloods. In this study, we developed an improved model with this feature and found it to be effective for modeling low salinity waterfloods.
Enhancing Oil Recovery Using Aqueous Dispersions of Silicon Dioxide Nanoparticles: The Search for Nanoscale Wettability Alteration Mechanism
Authors: Afekare Dayo
Published: October 2020

Enhancing oil recovery using silica-based particles appears to be a promising technique. Yet, this method remains novel partly because it suffers from inadequate scientific understanding. In this study, a nanoscale investigation of silicon dioxide nanoparticles for EOR in tight oil rocks is performed using high-resolution force spectroscopy with a case study of Tuscaloosa Marine Shale (TMS).

The dominant rock minerals in TMS were used as substrates and COOH-, C6H5-, and CH3- terminated probes were used to represent crude oil functional groups for atomic force microscope (AFM) experiments. Next, different concentrations of hydrophilic SiO2 nanoparticles dispersed in 1 wt% NaCl were prepared and used as nanofluids. Geologic substrates were immersed in fluid cells and AFM was used to characterize chemical probe/substrate adhesion forces and energies in respective solutions.

Atomic force microscope results showed that aqeous dispersions of silicon dioxide nanoparticles promote wettability towards a less oil-wet state at the nanoscale by overcoming the adhesion force and energy barrier to disrupt the oil-rock interface and create new nanofluid-rock and oil-rock interfaces. This is applicable to tight oil reservoirs containing predominantly organic and inorganic pores and polar and non-polar crude oil fractions such as TMS. Percentage changes in adhesion energy derived from AFM were in excellent agreement with existing classical theories. Through surface characterization, the irreversible adsorption of nanoparticles which is central to sustainable wetting effects was observed. Adhesion force and energy are resolved in multiple intermolecular interactions such as electrostatic – or electric double layer – repulsion, non-electrostatic interaction and structural interactions. This study throws new light on fundamental mechanisms of nanofluid EOR at the nanometer scale.
Graphene as a Surfactant Carrier: A Performance Study for Enhanced Oil Recovery Applications
Authors: Bardhan Anirudh
Published: October 2020

Graphene as surfactant carrier material for EOR/IOR is used. Its performance is evaluated through adsorption, desorption, interfacial tension and emulsification studies. Moreover, the kinetic and thermodynamic parameters are identified in order to understand the physicochemical behavior pertaining to its applicability in surfactant flooding. The surfactant carrier, graphene is acquired and its physicochemical behavior is characterized by X-Ray diffraction, Fourier transform infrared spectroscopy, surface area analysis, etc. The uptake capacity of the surfactant is investigated by adsorption and desorption studies at different subsurface conditions. The kinetics of the process are identified to understand the rate and order of the reaction, whereas thermodynamic behavior of the surfactant carrier is evaluated to find its Gibbs free energy, enthalpy, entropy, activation energy, etc. Further, a reduction in interfacial tension and stability of emulsion between crude oil and brine is inspected. The uptake capacity of the surfactant obtained from the adsorption and desorption study confirmed that adequate quantities of surfactant can be transported into the deep subsurface with minimal loss. This infers the requirement of surfactant in lesser quantity when compared to surfactants without any nanocarrier. Similarly, a reduction in interfacial tension and increase in emulsion stability is expected to be increased. Furthermore, graphene shows a remarkable change in hydrophobicity with a change in pH and salinity which indicates that the properties can be suitably tailored as per requirement, making it a good candidate for surfactant EOR/IOR. Also, the obtained thermodynamic data suggest endothermic and spontaneous adsorption behavior, which may be a favorable phenomenon when subjected to the higher subsurface temperature. Graphene as a surfactant carrier and its performance is investigated for the first time rendering it unique for EOR/IOR applicability studies.
Formation Integrity and Pore System Evaluation for Stimulated Sandstone Formation Using In-Situ Generated Acid Catalyzed by A Fused Chemical Reaction
Authors: Gomaa Ibrahim
Published: October 2020

This study aims at evaluating the mechanical integrity and the changes in the pore system of illitic sandstone formations being treated with HF acid generated in-situ and thermochemical fluids (TCF). Firstly, the acid-generating fluids were injected separately inside the core within a typical core flooding experiment. After that the core permeability, NMR porosity and rock static and dynamic parameters such as rock strength (UCS), dynamic Young's modulus, Poisson's ratio, shear modulus and bulk compressibility were evaluated before and after the treatment. Sand production prediction model was used to examine the potential of sand production problems for the cores treated with the in-situ generated acid (ISGA) and the TCF.

Treating Scioto cores with the ISGA only led to permeability enhancement with final to initial permeability ratio KfinalKinitial of 1.2. In addition, treating the same cores with acid generating fluids and thermochemicals resulted in higher permeability enhancement with KfinalKinitial of 485. This higher enhancement in the formation permeability was attributed to the creation of some microfractures as was proved using the NMR scans. There was a reduction of the cores' static and dynamic parameters after being treated with the ISGA. This reduction was even higher after treating the core with thermochemical fluids. However, the sand production prediction model stated that the reduction in rock mechanical parameters would not lead to sand production problems.
Analytical Solutions for Predicting Fracture Outlet Temperature of Produced Fluid from Enhanced Geothermal Systems with Different Well-Completion Configurations
Authors: Onay Mehmet Emin
Published: October 2020

Enhanced Geothermal Systems (EGS) are those in which advanced drilling and fracturing technologies are required to extract heat energy from the earth's crust in areas where higher heat flow than average and natural permeability and/or fluid content are lacking. In order to make an EGS project successful, extensive studies should be conducted, especially for the purposes of evaluating and predicting future thermal performance of subsurface system. The main objective of this study is to present novel analytical models and their analytical solutions for predicting the temperature and heat recovery behaviors of four different hydraulically fractured well configurations of EGS created in a hot dry rock formation. The configurations considered are a single-vertical-planar fracture intersecting a horizontal-well doublet system orienting in a horizontal plane, multi-vertical-planar fractures intersecting a horizontal-well doublet system orienting in horizontal plane, a single-vertical-planar fracture intersecting a horizontal-well doublet system orienting in a vertical plane, and multi-vertical planar fractures intersecting a horizontal-well doublet system orienting in a vertical plane. In developing these analytical solutions, basic concepts of conservation of heat due to convection and conduction have been applied. The partial differential equations describing and coupling convective heat transfer in hydraulically fractured wells with conductive heat transfer in the matrix system, which is assumed to be homogenous, for each well completion type were solved subject to the appropriate initial, interface and outer boundary conditions by using the method of Laplace transformation and inverted numerically by using the Stehfest inversion algorithm (Stehfest, 1970). The solutions presented in this study treat hydraulic fractures as porous media. The analytical solutions derived were validated by using the existing solutions available in the literature for the single-fracture and multiple-fractures intersecting a horizontal-well doublet system, given by Arpaci et al. (1966) and Gringarten et al. (1975) who both treat hydraulic fractures 100% porous, respectively. The solutions developed for each of the well completion type were used to perform parametric studies to investigate the effect of parameters on temperature of produced fluid and in return on feasibility of a given EGS completion. Main conclusions obtained from the extensive parametric studies are: Geothermal gradient has substantial effect on fracture outlet temperature of the produced fluid in EGS models having vertical flow in fractures especially for low injection volumetric flow rates, hydraulic fracture porosity has substantial effect on determining intrinsic velocity of fluid within pores of fracture, and in EGS models having vertical flow, downward flow case is observed to have better performance in terms of heat recovery factor than upward flow case of the same model.
Development of a Tracer Analysis System Using Dye Tracers
Authors: Seif Hemed Thraiye
Published: October 2020

The scope of this project involves finding a passive dye tracer that will improve the efficiency of tracer analysis for lab and field applications. The idea is to develop an "expert system" to obtain tracer concentration based on the colour change of outlet samples, i.e. a computer-based visual analysis method, aimed at circumventing complicated analysis methods which require spectrometers or chromatographs. This method shall correlate the mixture colour to component concentration. Primary considerations for selecting a proper component are: dye and its analysis procedure should be cost-effective, dye component should be benign, it should not interact with the rock and fluid, and it should be environmentally friendly. With this method, lab and field tracer applications can be simplified, and tracer concentration curves can be obtained immediately after collecting the samples.
Patient and health system factors associated with pretreatment loss to follow up among patients diagnosed with tuberculosis using Xpert® MTB/RIF testing in Uganda 
Authors: Zawedde-Muyanja Stella , Katamba Achilles , Cattamanchi Adithya , Castelnuovo Barbara , Manabe Yukari C
Published: October 2020

Background: In 2018, Uganda only 65% of incident cases of tuberculosis were started on treatment. Pretreatment loss to follow up is an important contributor to suboptimal treatment coverage. We aimed to describe the patient and health facility-level characteristics associated with pretreatment loss to follow up among patients diagnosed with pulmonary tuberculosis at public health facilities in Uganda. Methods: At ten public health facilities, laboratory register data was used to identify patients aged 15 years who had a positive Xpert®MTB/RIF test. Initiation on TB treatment was ascertained using the clinical register. Factors associated with not being initiated on TB treatment within two weeks of diagnosis were examined using a multilevel logistic regression model accounting for clustering by health facility. Results:From January to June 2018, 510 patients (61.2% male and 31.5% HIV co-infected) were diagnosed with tuberculosis. One hundred (19.6%) were not initiated on TB treatment within two weeks of diagnosis. Not having a phone number recorded in the clinic registers (aOR 7.93, 95%CI 3.93-13.05); being HIV-infected (aOR 1.83; 95% CI: 1.09-3.26) and receiving care from a high volume health facility performing more than 12 Xpert tests per day (aOR 4.37, 95%CI 1.69-11.29) and were significantly associated with pretreatment loss to follow up. Conclusion: In public health facilities in Uganda, we found a high rate of pretreatment loss to follow up especially among TBHIV co-infected patients diagnosed at high volume health facilities. Interventions to improve the efficiency of Xpert® MTB/RIF testing, including monitoring of the TB care cascade should be developed and implemented.
Inhibitory effects of iron depletion plus eribulin on the breast cancer microenvironment
Authors: Goto Wataru , Kashiwagi Shinichiro , Asano Yuka , Takada Koji , Morisaki Tamami , Takahashi Katsuyuki , Fujita Hisakazu , Shibutani Masatsune , Amano Ryosuke , Takashima Tsutomu , Tomita Shuhei , Hirakawa Kosei , Ohira Masaichi
Published: October 2020

Background: Iron is required for the proliferation of cancer cells, and its depletion suppresses tumor growth. Eribulin mesylate (eribulin), a non-taxane microtubule inhibitor, disrupts the tumor microenvironment via vascular remodeling and obstruction of the epithelial-mesenchymal transition (EMT). Herein, we investigated the effects of the iron chelator on tumor-related properties of breast cancer cells and the effects of iron chelator plus eribulin on tumor growth in vivo.Methods: Two triple-negative breast cancer (TNBC) cell lines, MDA-MB-231 and BT-549, and one hormone-receptor positive breast cancer cell line, MCF-7, were used in our study. Cell proliferation, cell migration, cell cycle position, and gene expression were analyzed via MTT assays, wound-healing assays, flow cytometry, and quantitative real-time-polymerase chain reaction, respectively. For the in vivo experiments, mice with breast cancer xenografts were treated with the inhibitors, alone or together, and tumor volume was determined.Results: Iron chelator inhibited breast cancer cell proliferation and decreased the proportion of S-phase cells. Conversely, it induced hypoxia, angiogenesis, EMT, and immune checkpoints, as determined by quantifying the expression of marker mRNAs in MDA-MB-231 and MCF-7 cells. Eribulin suppressed the expression of the hypoxia and EMT related marker mRNAs in the presence of iron chelator. Iron chelator plus eribulin inhibited tumor growth in vivo to a greater extent than did either inhibitor alone.Conclusions: Although iron chelator induces oncogenic events (hypoxia, angiogenesis, EMT, and immune checkpoints), it may be an effective treatment for breast cancer when administered in combination with eribulin.
Relationship between formulaic breast volume and risk of breast cancer based on linear measurements
Authors: Li Xiaoxia , Zhou Chunlan , Wu Yanni , Chen Xiaohong
Published: October 2020

Background: Whether breast volume is a risk factor for breast cancer is controversial. This study aimed to evaluate whether a significant association between breast volume and risk of breast cancer, based on linear measurements,was present by applying propensity score matching (PSM).Methods: The study was designed as a hospital-based case-control study. Between March 2018 and May 2019, 208 cases and 340 controls were retrospectively reviewed. Information on menarche, smoking, feeding mode, oral contraceptives, reproductive history and family history was obtained through a structured questionnaire. Breast volume was calculated using a formula based on linear measurements of breast parameters. Cox regression and PSM were used to estimate odds ratios and 95% confidence intervals for breast cancer using risk factors adjusted for potential confounders.Results: There was a significant difference in breast volume between the two groups before propensity score matching(P = 0.014) . Binary logistic regression showed that the risk of breast cancer was slightly higher in the case group with larger breast volumes than in the control group（P = 0.009, OR = 1.002， 95%CI：1.000~1.003). However, there was no significant statistical difference between the two groups using an independent sample Mann-Whitney U test (P = 0.438) or conditional logistic regression (P = 0.446).Conclusions: After PSM for potential confounding factors, there is no significant difference in breast volume estimated by BREAST-V formula between the case group and the control group. The risk of breast cancer may not be related to breast volume in Chinese women.
Psychosocial Support Interventions for Improved Adherence and Retention in ART care for Young People Living with HIV (10-24 years): A Scoping Review
Authors: Okonji Emeka Francis , Mukumbang Ferdinand C. , Orth Zaida , Vickerman-Delport Shelley A. , Wyk Brian Van
Published: October 2020

Background: Mental health disorders such as high levels of anxiety, isolation, depression and suicide ideation reported among young people living with HIV (10-24 years; YPLWH) contribute significantly to poor medication adherence and retention in care. While there is evidence supporting the role of psychosocial support interventions in promoting adherence and retention in antiretroviral treatment (ART) among adults living with HIV, there is little evidence on the role of psychosocial support on medication adherence among YPLWH . This scoping review was designed to identify and classify the types and effects of psychosocial support interventions designed to improve adherence and retention in ART among adolescents and young people living with HIV globally.Method: We searched six electronic databases (i.e., Scopus, Pubmed and EBSCOHost (Academic Search Premier, CINAHL, Psycarticles and Medline). Six relevant articles published between 2011 and 2019 met our inclusion criteria. We extracted information relevant to the nature and outcomes of the reported interventions using thematic content analysis informed by the Population, Intervention, comparison, outcome, and time (PICOT) framework.Results: Four distinctive treatment modalities that focused on improving ART adherence and retention in care were identified: individual counselling, support groups, family-centered services, and treatment supporters.Conclusion: There is a dearth of psychosocial support interventions to improve adherence and retention in ART amongst adolescents and young adults living with HIV. Future research and programming should seek to address psychosocial support interventions or approaches specifically designed to address the needs of adolescents and young adults living with HIV.PROSPERO: Registration CRD42018105057
Onodera’s prognostic nutritional index is a strong prognostic indicator for patients with hepatocellular carcinoma after initial hepatectomy, especially patients with preserved liver function
Authors: Tanemura Akihiro , Mizuno Shugo , Hayasaki Aoi , Gyoten Kazuyuki , Fujii Takehiro , Iizawa Yusuke , Kato Hiroyuki , Murata Yasuhiro , Kuriyama Naohisa , Kishiwada Masashi , Sakurai Hiroyuki , Isaji Shuji
Published: October 2020

Background Several inflammation-based scores are used to assess the surgical outcomes of hepatocellular carcinoma (HCC). The aim of the present study was to elucidate the prognostic value of the prognostic nutritional index (PNI) in HCC patients who underwent hepatectomy with special attention to preoperative liver functional reserve. Methods Preoperative demographic and tumor-related factors were analyzed in 189 patients with HCC undergoing initial hepatectomy from August 2005 to May 2016 to identify significant prognostic factors. Results Multivariate analysis for overall survival (OS) revealed that female gender (p=0.005), tumor size (p<0.001) and PNI (p=0.001) were independent prognostic factors. Compared to the High PNI group (PNI ≥37, n=172), the Low PNI group (PNI <37, n=17) had impaired liver function and significantly poorer OS (13% vs. 67% in 5-year OS, p=0.001) and recurrence-free survival (RFS) (8 vs. 25 months in median PFS time, p=0.002). In the subgroup of patients with a preserved liver function of LHL15 ≥0.9, PNI was also independent prognostic factor, and OS (21% vs. 70% in 5-year OS, p=0.008) and RFS (8 vs. 28 months in median PFS time, p=0.018) were significantly poorer in the Low PNI group than the High PNI group. Conclusions PNI was an independent prognostic factor for HCC patients who underwent hepatectomy. Patients with PNI lower than 37 were at high risk for early recurrence and poor patient survival, especially in the patients with preserved liver function of LHL ≥0.9.
Factors Influencing Cancer Genetic Somatic Mutation Test Ordering By Cancer Physicians
Authors: Demeshko Anastassia , Pennisi David J. , Narayan Sushil , Gray Stacy W. , Brown Matthew A. , McInerney-Leo Aideen M.
Published: October 2020

Background: Clinical whole exome sequencing was introduced in an Australian centre in 2017, as an alternative to Sanger sequencing. We aimed to identify predictors of cancer physicians’ somatic mutation test ordering behaviour. Methods: A validated instrument assessed somatic mutation test ordering, genomic confidence, perceived utility of tumour molecular profiling, and percent of patients eligible for targeted therapy. A cash incentive was included in 189/244 questionnaires which were mailed to all Queensland cancer specialists in November 2018. Results: 110 participated (response rate 45%); 54.7% oncologists, and the remainder were surgeons, haematologists and pulmonologists. Oncologists were more likely to respond (p=0.008), and cash incentive improved the response rate (p<0.001). 67/102 (65.7%) of physicians ordered ≥5 somatic mutation tests annually. Oncologists saw 86.75 unique patients monthly and ordered 2.33 somatic mutation tests (2.2%). An average of 51/110 (46.1%) reported having little/no genomic confidence. Logistic regression identified two significant predictors of somatic mutation test ordering: being an oncologist (OR 3.557, CI 1.338-9.456; p=0.011) and having greater confidence in interpreting somatic results (OR 5.926, CI 2.230-15.74; p<0.0001). Conclusions: Consistent with previous studies, the majority of cancer physicians ordered somatic mutation tests. However, the percentage of patients on whom tests were ordered was low. Almost half respondents reported low genomic confidence. Somatic mutation test ordering was higher amongst oncologists and those with increased confidence in interpreting somatic variants. It is unclear whether genomically confident individuals ordered more tests or whether ordering more tests increased genomic confidence. Educational interventions could improve confidence and enhance test ordering behaviour.
Evaluation of NaCl and MgCl2 heat exchange fluids in a deep binary geothermal system in a sedimentary halite formation
Authors: Moore Kayla R , Holländer Hartmut M.
Published: October 2020

Halite formations are attractive geothermal reservoirs due to their high heat conductivity, resulting in higher temperatures than other formations at similar depths. However, halite formations are highly reactive with undersaturated water. An understanding of the geochemical reactions that occur within halite-saturated formation waters can inform decision making regarding well construction, prevention of well clogging, formation dissolution, and thermal short-circuiting. Batch reaction and numerical 3-D flow and equilibrium reactive transport modeling were used to characterize the produced NaCl-brine in a well targeting a halite-saturated formation. The potential for inhibition of precipitation and dissolution using an MgCl 2 -brine and NaCl+MgCl 2 -brine were also investigated. Within the injection well, with heating from 70 to 120°C, the solubility of halite decreases resulting in the potential dissolution of 0.479 mol kg -1 at the formation. Cooling from 120 to 100°C in the production well results in precipitation of 0.196 mol kg -1 halite as well as anhydrite, brucite, carnallite, goergeyite, gypsum, halite, kieserite and polyhalite. Introduction of MgCl 2 , resulting in a common Cl - ion, into the heat exchange brine resulted in a decreased potential for dissolution by 0.290 mol kg -1 as the heat exchange fluid entered the formation and within the formation itself, as well as decreased precipitation within the production well, compared to the NaCl-brine. The halite solubility was altered by changes in pressure up to 0.045 mol kg -1 . This indicates that designing and monitoring the composition of heat exchange fluids in highly saline environments is an important component in geothermal project design.
Design, Development and Deployment of a Web-Based Interoperable Registry for Inherited Retinal Dystrophies in Portugal – the IRD-PT
Authors: Marques João Pedro , Carvalho Ana Luísa , Henriques José , Murta Joaquim Neto , Saraiva Jorge , Silva Rufino
Published: October 2020

BACKGROUND
The development of multicenter patient registries promotes the generation of scientific knowledge by using real-world data. A country-wide, web-based registry for inherited retinal dystrophies (IRDs) empowers patients and community organizations, while supporting formal partnerships with investigators and stakeholders in the global aim to develop high-value, high-utility research. We aim to describe the design, development and deployment of a country-wide, web-based, user-friendly and interoperable registry for IRDs – the IRD-PT.

RESULTS
The IRD-PT is a clinical/genetic research registry included in the retina.pt platform (http://www.retina.com.pt), which was developed by the Portuguese Retina Study Group. The retina.pt platform collects data on individuals diagnosed with retinal diseases, from several sites across Portugal, with over 1800 participants and over 30,000 consultations to date. The IRD-PT module interacts with the retina.pt core system which provides a range of basic functions for patient data management, while the IRD-PT module allows data capture for the specific purpose of IRDs. All IRDs are coded accordingly to the International Statistical Classification of Diseases and Related Health Problems (ICD) 9, ICD 10, ICD 11, and Orphanet Rare Disease Ontology (ORPHA codes) to make the IRD-PT interoperable with other IRD registries across the world. Furthermore, the genes are coded according to the Ontology of Genes and Genomes and Online Mendelian Inheritance in Man, whereas signs and symptoms are coded according to the Human Phenotype Ontology. The IRD-PT module pre-launched at Centro Hospitalar e Universitário de Coimbra , the largest reference center for IRDs in Portugal. As of April 1 st 2020, finalized data from 537 participants were available for this preliminary analysis.

CONCLUSIONS
In the specific field of rare diseases, the use of registries increases research accessibility for individuals, while providing clinicians/investigators with a coherent data ecosystem necessary to boost research. Appropriate design and implementation of patient registries enables rapid decision making and ongoing data mining, ultimately leading to improved patient outcomes. We have described here the principles behind the design, development and deployment of a web-based, user-friendly and interoperable software tool aimed to generate important knowledge and collect high-quality data on the epidemiology, genomic landscape and natural history of IRDs in Portugal.
Enset-Based land use land cover change detection and its impact on soil erosion in Meki river watershed, Western Lake Ziway Sub-Basin, Central Rift Valley of Ethiopia
Authors: Woldesenbet Alemu Beyene , Wudmatas Sebsebe Demisew , Denboba Mekuria Argaw , Gebremariam Azage Gebreyohannes
Published: October 2020

Background Water erosion, upland degradation and deforestation are key environmental problems in Meki river watershed. . The study assessed the land use land cover change (LULCC) over the last 30 years, examined the contribution of the indigenous Enset-Based land use system (EBLUS) which was not studied so far in reducing soil erosion and preventing Lake Ziway from sedimentation. Based on the outcomes, the research recommended appropriate management interventions based on priority mapped to sustainably manage the watershed. GPS based Ground truth data sampling and collection, Geo-statistical interpolation and RUSLE model were applied for soil erosion modeling. The LULCC detection and analysis was conducted to generate the spatial inputs using ERDAS Imagine 2014. Result Meki river watershed has 2110.4 km² of area which is dominantly covered by cultivated land use system (41.5%), Enset-Based land use system (EBLUS)(10.65%), Bush and Chat land use system (25.6%), Forest and plantations land use system (14.14%), built up (7.4%) and water bodies (0.75%). Severity class of High to severe range (18-125tha -1 yr -1 ) recorded in the sub-watersheds irrespective of the land use systems and facing sever degradation problem that increase in soil loss in all land use systems from 1987 to 2017. The average soil loss of 30.5tha -1 yr-1 and 31.905tha-1yr-1 verified from Enset growing zones and non-Enset growing zones of the watershed respectively. Conclusion Enset-Based land use system (EBLUS) saves significant amount of soil despite the steepness of the slopes of the Enset growing zones of the watershed. Hence, expansion of EBLUS can contribute in sustaining Lake Ziway by reducing soil loss rate and sedimentation problem for ecological sustainability of the watershed. Therefore, separate land use policy and awareness creation are mandatory for such EBLUS expansion, integrated watershed management and conservation of the natural environment in the watershed.
Nutritional status of school children living in Northern part of Sri Lanka
Authors: Sathiadas Gitanjali , Annieston A , Arunath V , Kasthuri T , Wickramasinghe V P
Published: October 2020

Background Nutritional status is an important indicator for measuring quality of life in children. A region that is recovering from war will face many problems related to nutrition. Very few studies have addressed the nutritional problems in school-going children.. This study was undertaken to identify the prevalence of nutritional status of school children from Northern Sri Lanka and associated socio-demographic factors Methods A community based cross-sectional study was carried out using multistage stratified proportionate cluster among healthy children attending schools in the Northern part of the country . Height and weight were measured and the Body Mass Index (BMI) was calculated [weight (kg)/Height (m) ²]. BMI-for-age z-score (BAZ) and Height for age Z (HAZ) scores were determined and WHO growth references were used to categorise the nutritional status of the children. Correlation between various nutritional problems with Maternal education and household income was assessed. Results A total of 1012 children were recruited, and the mean age and standard deviation were 11.12±1.77yrs. Girls in the age ranges of 9-14 were heavier and taller when compared to the boys compatible to the pubertal growth spurt. Stunting based on the height for age was seen in 10.9% of boys and 11.8% of girls. Wasting based on BMI for age WHO standard (WHO 2007) was seen in 30.6% of boys and 29.1% of the girls. The prevalence of overweight was 11% and Obesity was 6.3% of the population. Obesity was predominantly seen in boys (4.2%) and it was significantly higher when compared to the girls (2.1%) (p <0.001). Older boys (>10 years) were significantly affected more than the younger ones (p <0.01). The prevalence of wasting, stunting, overweight and obesity had significant variations in different educational zones comparable with the geographical areas. Maternal Education and Family income had a significant impact on the prevalence of stunting and obesity. (p<0.001). Conclusion Findings suggest that stunting, wasting, overweight and obesity are prevalent among 6-16-year-old leading to concerns in public health. The nutritional status significantly vary according to the geographical location maternal education and the household income .
CompLement C5 Antibodies for decreasing brain injury after aneurysmal Subarachnoid Haemorrhage (CLASH): study protocol for a randomized controlled phase II clinical trial
Authors: Koopman Inez , Rinkel Gabriel J.E. , Vergouwen Mervyn D.I.
Published: October 2020

Background The inflammatory response after aneurysmal subarachnoid haemorrhage (aSAH) has been associated with early brain injury, delayed cerebral ischemia, poor functional outcome, and case-fatality. In experimental SAH studies, complement C5 antibodies administered shortly after SAH reduced brain injury with approximately 40%. Complement component C5 may be a new therapeutic target to reduce brain injury and hereby improve outcome after aSAH. We aim to investigate the pharmacodynamic efficacy and safety of eculizumab (complement C5 antibody) in patients with aSAH.

Methods A randomized, controlled, open-label, phase II clinical trial with blinded outcome assessment. Eculizumab (1200 mg) is administered intravenously <12 hours, on day 3 and on day 7 after ictus. Patients in the intervention group receive prophylactic antibiotics for 4 weeks, and those with a central line or an external ventricular shunt and a positive fungal or yeast culture also receive prophylactic antifungal therapy for 4 weeks. The primary outcome is C5a concentration in cerebrospinal fluid (CSF) on day 3 after ictus. Secondary outcomes include the occurrence of adverse events, inflammatory parameters in blood and CSF, cerebral infarction on magnetic resonance imaging, and clinical- and cognitive outcomes. We aim to evaluate 26 patients with CSF assessments, 13 in the intervention group and 13 in the comparator group. To compensate for early case-fatality and inability to obtain CSF, we will include 20 patients per group.

Discussion The CLASH trial is the first trial to investigate the pharmacodynamic efficacy and safety of eculizumab in the early phase after aSAH.

Trial registration Netherlands Trial Register: NTR6752, https://www.trialregister.nl/trial/6579. Registered on 27 October 2017. European Clinical Trials Database: EudraCT 2017-004307-51.
Molecular detection of Rickettsia in fleas from micromammals in Chile
Authors: Salas Lucila Moreno , Carniglia Mario Espinoza , Schmeisser Nicol Lizama , Fuentes Luis Gonzalo Torres , Fuente María Carolina Silva de la , Lareschi Marcela , Acuña Daniel González
Published: October 2020

Background: Rickettsial diseases are considered important in public health due to their dispersal capacity determined by the particular characteristics of their reservoirs and/or vectors. Among the latter, fleas play an important role, since the vast majority of species parasitize wild and invasive rodents, so their detection is relevant to be able to monitor potential emerging diseases. The aim of this study was to detect, characterize, and compare Rickettsia spp. from the fleas of micromammals in areas with different human population densities in Chile. Methods: The presence of Rickettsia spp. was evaluated by standard polymerase chain reaction (PCR) and sequencing in 1315 fleas collected from 1512 micromammals in 29 locations, with different human population densities in Chile. A generalized linear model (GLM) was used to identify the variables that may explain Rickettsia prevalence in fleas. Results: DNA of Rickettsia spp. was identified in 13.2% (174 of 1315) of fleas tested. Fifteen flea species were found to be Rickettsia-positive. The prevalence of Rickettsia spp. was higher in winter, semi-arid region and natural areas, and the infection levels in fleas varied between species of flea. The prevalence of Rickettsia among flea species ranged between 0–35.1%. Areas of lower human density showed the highest prevalence of Rickettsia. The phylogenetic tree showed two well-differentiated clades with Rickettsia bellii positioned as basal in one clade. The second clade was subdivided into two subclades of species related to Rickettsia of the spotted fever group. Conclusions: To our knowledge, this is the first report of the occurrence and molecular characterization of Rickettsia spp. in 15 flea species of micromammals in Chile. In this study, fleas were detected carrying Rickettsia DNA with zoonotic potential, mainly in villages and natural areas of Chile. Considering that there are differences in the prevalence of Rickettsia in fleas associated with different factors, more investigations are needed to further understand the ecology of Rickettsia in fleas and their implications for human health.