bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Inorganic-Crosslinked-Based Gelled Acid System for High-Temperature Applications
Authors: AlOtaibi Fares , Dahlan Mohammed , Khaldi Mohammed , AlGhamdi Abdulaziz , Al-Hulail Ibrahim
Published: February 2020

Hydrochloric (HCl) crosslinked gelled acid systems have been extensively used in acid fracturing and matrix acidizing to help achieve acid diversion during stimulation treatments. These systems also help control fluids leakoff and help retard the acid reaction to allow deeper acid penetration. Currently, many in-situ crosslinked gelled acid systems generally consist of polymers, an iron crosslinker, and a breaker agent, in addition to other additives. This paper discusses an alternative crosslinker that provides effective diversion with minimal residuals at temperatures up to 275°F.

A non-iron-based crosslinker has been developed for in-situ high-strength gelled acid systems that vary between 5 to 20 wt% HCl acid. The coreflooding experiments were effectively conducted for permeability ranges of up to 70 md. This system showed a stable fluid at downhole conditions, initially building viscosity between a pH range of 1.5 to 3.0. Then, as acid continues to further react with calcium carbonate and the pH becomes higher than 3, the crosslinked fluid begins to break down and the fluid viscosity decreases. Several experiments were conducted to assess the performance of this novel system. Additionally, corrosion tests were performed to evaluate the treatment fluid corrosion rate at a temperature of 275°F.

The testing results show that the evaluated gelled acid system is stable at temperatures up to 275°F. The system profile as a function of pH showed the ability to provide diversion during different stimulation treatments. Additionally, the coreflood results showed that the new gelled acid is capable of forming wormholes without any significant associated formation damage caused by the gel. The effect of corrosion inhibitors on this system at 300°F, along with other additives, was also investigated.
Manuscript Title: Paraffin/Asphaltene Cleaning Formulations-Lab Design and Case Studies
Authors: Stanciu Cornell , Fernandez Jorge M.
Published: February 2020

Paraffin and asphaltene issues are common throughout the Oilfield, from upstream to midstream and even to downstream, costing the industry billions of dollars every year. They range from near wellbore damage to flow restrictions in the tubulars or in the pipes used to transport the hydrocarbons from the production field to contamination of equipment or means of transportation (trucks, tankers, railcars, boats) and to formation of coke deposits in reactors at the processing facilities.

Mitigating the paraffin/asphaltene issues wherever they appear is of high importance to ensure high production/transportation rates. Given the variety of problems, the wide composition ranges of crudes as well as the many differences between reservoir characteristics in different locations the R&D efforts to find efficient solutions to these complex situations have to be very application specific. In this paper we will present a few examples of formulations that were designed by leveraging the in-house expertise in the area along with simple lab methods and techniques, such as design of experiments (DOE), crude chemical analysis, cold finger instrument analysis, optical microscopy, viscosity measurements, Hegman gauge surface cleaning, porous surface cleaning.

The results show how appropriate combinations of surfactants and solvents, specifically designed for each application, can help mitigating the complex issues posed by paraffin/asphaltene precipitation. The influence of various hydrophobes-in both the non-ionic and the anionic surfactants utilized- on the final performance of the designed formulations will be discussed.

Representative case studies will be emphasized to better illustrate the efficacy of the final products in the application space they were designed for. The solvents and surfactants used in these studies are viable alternatives to existing products on the market by offering better environmental profiles, increased efficiency at comparable or lower dosage, functional benefits over two or more applications or cost savings for the users.
Holistic Approach for a Successful Scale Squeeze Treatment Using Core Flood Data from Other Reservoir
Authors: Sundramoorthy Jega Divan , Ibrahim Mohamed Farouk , Nordin Nur Fauzan , Abd Rahim Mohd Adam , Wan Ismail Wan Akmal
Published: February 2020

This paper describes field experience of designing a successful scale squeeze program for an oil well. This was done utilizing an adsorption isotherm derived from a core flood data from other reservoir. Correlation and reliability of the adsorption isotherm with actual field flow back data after squeeze treatment for a period of 18-month are given. Moreover, utilizing the knowledge generated, a bespoke multilayer adsorption isotherm was optimized for a treated well for more efficient squeeze design for next treatment.

In order to achieve our objective, an adsorption isotherm from other reservoir core flood was first generated. With the knowledge not limited to current candidate well production rates, well properties, perforation height, number of zones and other essential parameters, a 18-month squeeze treatment program was designed. Water chemistry 18-month data was utilized to validate the scale squeeze design. An improved multilayer adsorption isotherm bespoke for this well was generated.

In conjunction with flow-back production data, a scheduled sampling program and water analysis utilizing Inductively Coupled Plasma (ICP) for post treatment Scale Inhibitor (SI) residuals data was collected to validate the adsorption isotherm derived from other reservoir. As predicted by the model for post treatment monitoring, the SI residual concentration; back calculated from SI chemistry utilized for the treatment are found to have an excellent correlation with the adsorption isotherm derived from a different reservoir. Hence, the 18-month squeeze design derived from a different reservoir was a great success. The slight difference between real flow back data and the adsorption isotherm generated from other reservoir become a benchmark to derive an improved adsorption isotherm to optimize the scale inhibition protection than the current treatment.

In summary, parameters such as mineralogy study, porosity, permeability, crude properties and dynamic scale loop (DSL) study are the utmost important information to be analyzed prior using other reservoir core flood data as reference. As results shown, these are the best way to generate squeeze design with limited information had in hand.
Engineered Reservoir Drilling Fluid Help Maximize Production in Gulf of Mexico Deepwater Horizontal Well
Authors: Wallace Shawn , Beeson Jeremy , Dalton Ferrill , David Elliot , Henry Ivan
Published: February 2020

A major operator in the Gulf of Mexico (GOM) desired to increase oil production to meet growing energy demand. To meet this challenge, the operator explored an alternate completion design to mitigate reservoir damage observed in previous producing wells and collaborated with the fluids provider to design a solution to address this concern. The design and solution ultimately applied resulted in "negative skin" with production rates far exceeding historical field rates. Additionally, the operator realized significant cost savings with this change in completion approach by eliminating traditional steps.

The development field had its unique challenges with ongoing depletion, wellbore instability risks, and compartmentalization in the reservoir, making access to thinner oil reservoirs challenging to develop. The standard completion approach was to drill with a synthetic-based fluid, perforate the casing, and perform a frac-pack completion. Using technology from another region, the operator elected to change the traditional cased hole frac-pack approach to drilling horizontally through the reservoir, run production screens, and perform an open hole gravel pack completion. In the fluids design phase, the fluids provider performed hydraulics modeling and laboratory testing on multiple formulations, including brine compatibility with formation water; formation response testing; high-pressure/high-temperature (HPHT) rheology and fluid loss; static age testing for intervals of 16 hours, 3 days, and 5 days; and contamination testing with solids, synthetic-based mud, and cement.

This paper discusses the methodology used in the design phase required to engineer a reservoir friendly fluid to meet the challenges faced with this complex well.
Performance Comparison of Novel Chemical Agents for Mitigating Water-Blocking Problem in Tight Gas Sands
Authors: Huang Hai , Babadagli Tayfun , Chen Xin , Li Huazhou , Zhang Yanming
Published: February 2020

Water-blocking can be a serious problem, causing a low gas production rate after hydraulic fracturing; a result of the strong capillarity in the tight sandstone reservoir aggravating the spontaneous imbibition. Fortunately, chemicals added to the fracturing fluids can alter the surface properties and thus prevent or reduce the water-blocking issue. We designed a spontaneous imbibition experiment to explore the possibility of using novel chemicals to both mitigate the spontaneous imbibition of water into the tight gas cores and measure the surface tensions between the air and chemical solutions. A diverse group of chemical species has been experimentally examined in this study, including a cationic surfactant (C12TAB), two anionic surfactants (O242 and O342), an ionic liquid (BMMIM BF4), a high pH solution (NaBO2), two nanofluids (Al2O3 and SiO2), and a series of house-made deep eutectic solvents (DES3-7, 9, 11, and 14). Experimental results indicate that the anionic surfactants (O242 and O342) contribute to low surface tensions, but cannot ease the water-blocking issue due to yielding a more water-wet surface. The high pH solution (NaBO2), ionic liquid (BMMIM BF-4), and brine (NaCl) significantly decrease the volume of water imbibed to the tight sand core through wettability alteration, and the cationic surfactant (C12TAB) leads to both surface tension reduction and an oil-wet rock surface, helping to prevent water-blocking. The different types of DESs and nanofluids exhibit distinctly different effects on expelling gas from the tight sand cores through water imbibition. This preliminary research will be useful in both selecting and utilizing proper chemicals in fracturing fluids to mitigate water-blocking problems in tight gas sands.
A New-Intermediate Strength Proppant Additive to Combat Asphaltene Deposition for Delivering Long Term Flow Assurance
Authors: Bestaoui-Spurr Naima , DeBenedictis Frances , Usie Marty , Bhaduri Sumit
Published: February 2020

Conventional asphaltene inhibitor treatments prevent asphaltene deposition in the production string and near the wellbore. However, these liquid injection treatments provide little to no protection deep into the reservoir. A new proppant like slow release asphaltene additive that is mixed with the proppant provides the possibility for long term flow assurance without conductivity impairments. This substrate allows more chemical to be transferred bottomhole resulting in longer treatments.

Traditional and nontraditional screening methods were used to demonstrate the longevity of the intermediate strength proppant like slow release asphaltene additive. The additive release profile was evaluated in a mixture with proppant and using untreated crude oil. Long-term protection was then determined. Furthermore, the proppant like substrate was characterized for its proppant like characteristics using API standards. Conductivity studies, to ensure the additive did not affect the proppant pack negatively, and fracturing fluid compatibility were also performed.

The results show that the proppant like slow release asphaltene additive has no conductivity losses at increased loadings and can provide a cost effective long-term flow assurance solution and can be used in the same range than an intermediate strength (ISP) proppant. Significant numbers of Gulf of Mexico (GoM) wells experience closure stresses in the range for the ISP product, opening up the possibility of using this product in this stress regime. Presence of asphaltene inhibitor in the deepest part of the fracture allows release of the chemical and resulting in reduction of precipitates and lowered conductivity damage to plugging. Controlled release of the chemical from the ISP like substrate allows only a certain amount of chemical needed for inhibitor control, preserving the rest of the inhibitor for subsequent release. The incorporation of a delay mechanism in the slow release asphaltene additive will provide increased protection as the well ages. This method allows longer protection time and affords a more cost-effective treatment.
Mineral Solubility Measurement and Prediction Under High Pressure, High Temperature Reservoir Conditions
Authors: Goodwin Neil , May Mark , Wilson Sam , Graham Gordon
Published: February 2020

Being able to predict formation damage due to near-wellbore scale deposition relies on accurate scale prediction modelling. It is recognised that the relative paucity of HPHT solubility data can result in inaccurate predictions, as current models typically extrapolate from solubility data obtained on simple systems under more conventional conditions. This paper describes the generation of additional fundamental solubility data under HPHT conditions, and compares the obtained values with several existing models.

A purpose-built laboratory test rig capable of making mineral solubility measurements up to 250 °C and 25,000 psi has been used in this work. Experimental methodology has been developed using calcium sulphate to demonstrate that equilibrium conditions have been reached. In this work, barium sulphate solubility data has been generated at conditions up to 200 °C and 20,000 psi in the presence of calcium or magnesium ions, as it was recognised that available data for oilfield-representative brines under such conditions was limited. Scale prediction modelling has been conducted using a range of software widely used in the industry to assess the accuracy of the models in these circumstances.

Results for calcium sulphate solubility, obtained earlier, indicated the importance of validating the test methodology, not just for each mineral but also under the required temperature and pressure, to verify that equilibrium solubility conditions have been achieved. Barium sulphate solubility increases with the addition of other divalent cations, but the extent of the increase is at present not accurately predicted by existing scale prediction models. In some cases, the predicted barium sulphate solubility was up to three times greater than the experimentally determined value. It is apparent that there is considerable scope for improvement of scale prediction models under HPHT conditions, particularly in complex brines systems, and that further fundamental solubility data is required to facilitate this.

This paper provides additional data for mineral solubility under HPHT conditions with more complex brines, which are more representative of those produced in oilfields. The work demonstrates the limitations of existing scale prediction modelling software under HPHT conditions, particularly in the presence of significant concentrations of other divalent cations, and illustrates areas where additional data and model development are critical to enable more accurate modelling of scaling risk.
Unplugging Standalone Sand Control Screens with High-power Shock Waves: An Experimental Study
Authors: Habibi Ali , Fensky Charles , Perri Mike , Roostaei Morteza , Fattahpour Vahidoddin , Mahmoudi Mahdi , Ghalambor Ali , Sadrzadeh Mohtada , Zeng Hongbo
Published: February 2020

Previous studies showed that different parameters influence the plugging of completion tools. These parameters include (i) rock mineralogy, (ii) reservoir fluids properties, and (iii) type of completion tools. Although different methods have been used for unplugging these tools, there is still debate regarding performance of these methods on damage removal.

In this study, we assessed the performance of high-power shockwaves generated from an electro-hydraulic stimulation (EHS) tool on cleaning completion tools plugged during oil production. These devices were extracted from different wells in Canada, Europe, and the US. First, we evaluated the extent of cleaning for the plugged completion tools using an EHS tool at the lab-scale. We examined the slots/screens before and after the treatment to show the performance of the EHS tool. Next, we analyzed the mineral composition and morphology of the plugging materials removed after the treatment by conducting X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive X-Ray Spectroscopy (EDS) analyses. Finally, we reviewed the pulsing stimulation treatment results applied to several field case studies.

The results of unplugging sand control devices at the lab-scale showed that more than 50% of plugged slots/screens were cleaned after 45 pulses of shockwaves. The characterization results showed that the main plugging materials are calcite, silicate, and iron-based components (corrosion products). The results of field case studies showed an improved oil production rate after the pulsing stimulation treatment.

This paper provides a better understanding of the performance of shockwaves on damage removal from plugged completion tools. The results could provide a complementary tool for production engineers to select a proper method for treating the plugged tools.
A Novel Shifting Tool to Operate Formation Isolation Valves
Authors: Balasubramanian Ganesh
Published: February 2020

Subsurface barrier valves such as a formation isolation valves (FIVs) isolate the formation from the production bore after the first perforation and the lower completion has been installed. This enables installation of the upper completion and in some cases multiple perforation runs before the well starts producing. During this time, they protect the formation from fluid loss and pressures by acting as a bi-directional fluid barrier. In addition to reduced rig time, a key advantage of FIVs is reduced intervention costs. FIVs can be openend and closed multiple times as required, mechanically with an intervention tool such as a primary shifting tool (PST) (Fig. 1). The conveyance method for PSTs can be on coiled tubing, work string, perforating string, or wireline (using a tractor and stroker) to open and close FIVs. PSTs then must reliably engage and release from shifting profiles in the FIVs to operate the valve and release from the profile after successful valve actuation.

Hence design of the PST is critical for relaible FIV operation. In the event of an emergency where the shifting profile in the tool is unable to release from the engaging profile in the FIV, it is critical to have an emergency release feature inherent in the PST that can enable release of the tool yet not damage the FIV. A novel methodology was developed to design PSTs to enable emergency release if required, through controlled plastic deformation at loads below work string shear limitation. This methodology also avoids fracturing of PST components as free-hanging pieces could be caught in the wellbore while pulling out the tool from the well after emergency release.
Nanocellulose as a New Degradable Suspension Additive for High-Density Calcium Brines
Authors: Deville Jay P. , Rady Ayten , Zhou Hui
Published: February 2020

Calcium-based brines, principally calcium chloride and calcium bromide, find widespread use as completion fluids and base fluids for reservoir drill-in fluids (RDF). The high ionic strength of these brines, combined with the chemical compatibility issues inherent with divalent ions, such as calcium, makes identifying additives for developing functional fluids challenging. While additives, such as hydroxyethyl cellulose, can provide viscosity to calcium brines, imparting the suspension properties needed for the transport of solid bridging agents or drill cuttings can be particularly problematic in divalent brines. Even the widely used and potent suspension agent, xanthan gum, in addition to being difficult to degrade, suffers from gelation and precipitation under certain conditions in high-calcium environments. In this study, nanocellulose, which has previously shown promise as a suspension additive in freshwater and low-salinity brines, was evaluated in high-density brine fluids.

Extensive laboratory evaluation of the commercially sourced nanocellulose was conducted in sodium chloride, calcium chloride, and calcium bromide brines. Rheological determinations were made of simple systems containing only brine plus the novel additive, as well as fully formulated RDF containing the additive with sized calcium carbonate bridging solids, alkalinity, and filtration control additives. This data was compared before and after aging at various temperatures and was further compared to other biopolymers that are used today in divalent brines. Stability of the fluids and the capability of the formulated fluids to suspend solids were also examined. Fluid-loss control of full formulations was compared under API conditions. Single-phase return permeability studies were conducted.

While results in sodium brines were mixed, nanocellulose was shown to outperform existing biomaterials in calcium brines. Nanocellulose was shown to be readily hydrated in the challenging high-density divalent environment and provided superior suspension to currently used fluid components at similar concentrations. Rheological performance of nanocellulose was found to be synergistic with bridging solids. In one particularly interesting example, it was also shown to complement a synthetic polymer in a high-temperature calcium bromide application.

Nanocellulose provides superior rheological performance and reduced formation damage potential compared to conventional materials in difficult high-density calcium chloride and bromide brines. The improved rheological profile and enhanced thermal stability of fluids formulated with nanocellulose, combined with a greater diversity of removal options, can facilitate expansion of the utility of calcium-based brines in well construction and completion applications.
Application of New Technologies to GoM for a Successful Open Hole Gravel Pack
Authors: Rodrigues Kegan , Kevin Whaley , Lawrence Ramnath , Kerimov Natig , Henry Ivan , Brune Lehron , Spicer Jared , Nwafor Chidi , Gutierrez Carlos , Filbrandt Joseph
Published: February 2020

This paper highlights the new drilling and completion technologies used in the delivery of the company’s first successful horizontal open hole gravel pack (OHGP) in the deep-water Gulf of Mexico (GoM). The well was drilled and completed with well performance exceeding the planned objectives.

A new drilling fluid system was needed to address the high depletion, minimize formation damage, and manage the wellbore stability challenges associated with depleted horizontal drilling stress anisotropy. A brine-based system inclusive of a reservoir drill-in fluid (RDIF), solids free screen running pill, and displacement push pill, were qualified. Managed pressure drilling (MPD) was employed to manage the drilling of depleted sands, and managed pressure cementing (MPC) was used for cementing across narrow frac gradient (FG) windows, a new application for the company. New real time drilling surveillance was also applied to allow for trajectory optimization and maximining the open hole (OH) length.

For the completion, a new high temperature gravel pack (GP) carrier fluid was developed to meet the high reservoir temperature and pressure requirements. This GP fluid was also designed to break on surface using an optimized breaker system, allowing for full capture with zero discharge. The sandface completion system included a new to GoM shunted wire wrap screen (WWS), y-manifold, and new lower completion hardware including an anti-swab GP service tool. New completion open hole displacement and GP procedures, to include a new skid-based GP pumping technique, were also implemented successfully.
Medical career expectations of academically talented high school students: A nationwide cross-sectional study in China
Authors: Wu Hongbin , Pei Leisi , Li Shan , Jiang Cheng
Published: February 2020

Background: Academically talented high school students (ATHSSs), an exceptional cohort, are not well studied for their career expectations, especially for those with medical career expectation (MCE). Nowadays, the public perception of the medical profession is changing in China. The purpose of this study was to answer questions about ‘is medicine attractive for ATHSSs and ‘what factors affect medical career expectations (MCE) for ATHSSs’ in China. Methods: A total of 16,479 representative ATHSSs in senior three completed a questionnaire and four different academic tests. Frequency statistics showed the proportion of ATHSSs with MCE. Unpaired t-tests were performed to find out the differences in demographics, family background, and academic performance between students with and without MCE. The logit models analysis were applied to explore the potential factors that affected the MCE of this exceptional group of students. Results: ATHSSs with MCE accounted for 20.6% (ranking 7/18) of the respondents. They were more likely to be female, came from relatively poorer families, lived in a rural area, and performed significantly worse in all academic tests except for mathematics, compared with those without MCE. In addition, the results revealed that gender (β=-0.436, p<0.01), region of hometown (β=-103, p<0.1), mother’s years of schooling (β=-0.019, p<0.05), and father’s occupational status (β=-0.005, p<0.01) contributed significantly to the MCE of academically talented students. Better performance in mathematics affected the MCE of ATHSSs taking the liberal arts and science tests differently. Conclusions: We found the medical career is becoming unattractive to academically talented students and the medical career may be loosing their aura in China. Students who have medical career expectations are likely to be females and to have a weak family background. We discuss implications for medical education.
Prevalence and determinants of modern contraceptive utilization among rural lactating mothers: Findings from the primary health care project in two northwest Ethiopian districts
Authors: Derso Terefe , Biks Gashaw Andargie , Yitayal Mezgebu , Ayele Tadesse Awoke , Alemu Kassahun , Debalkie Getu , Fekadu Hailab , Dellie Endalkachew , Azale Telake , Misganaw Bisrat , Kebede Adane , Fetene Destaw , G/medhin Tsegaye , Atnafu Asmamaw
Published: February 2020

Background : Contraceptive utilization is a guarantee to avert unwanted pregnancies. In Ethiopia however, more than half of the rural women have shorter birth intervals. Consequently, 17% and 8% of the births have been either mistimed (wanted at later date) or unwanted, respectively. Therefore, this paper investigated modern contraceptive utilization and its predictors among rural lactating women. Methods : A community based-cross-sectional study was conducted from May 01 to June 29, 2019, in Dabat and Gondar zuria districts, northwest Ethiopia. Data from 603 lactating mother were collected through face to face interviews using a structured questionnaire. Bivariate and multivariate logistic regression analyses were done to identify the independent predictors of modern contraceptive utilization. Results : The overall prevalence of modern contraceptive (MC) utilization rate was 45.8% [95% CI: 38.01, 53.59]. The contraceptive method mix was dominated by Depo-Provera (39.8%) followed by implants (4.8%). The odds of utilization of contraceptive were 5.58 times higher among mothers of children with fully immunized [AOR=5.58, 95% CI: 3.45, 9.01] compared to mothers whose children were vaccinated partially or not at all. Mothers who received antenatal [AOR= 1.743, 95% CI: 1.13, 4.43] and postnatal care [AOR=2.02, 95%CI: 1.24, 2.91) were 1.74 and 2.02 folds more likely to utilize modern contraceptives than mothers who did not receive such care, respectively. Conclusion : The prevalence of modern contraceptive utilization in own study area was lower than the planed national target. In the region, child immunization service is one of the promising platforms for reaching lactating mothers with modern contraceptive utilization. Our findings suggest that antenatal and postnatal care visits are the other key determinants of modern contraceptive utilization. Thus, in low-resource settings like ours, the health system approaches to improved antenatal and, postnatal care and child immunization services should be intensified with more effective advice on modern contraceptive utilization to reduce unwanted pregnancies. Key words : Contraceptive utilization, Postnatal care, Child immunization
Shedding light: A phylotranscriptomic perspective illuminates the origin of photosymbiosis in marine bivalves
Authors: Li Jingchun , Lemer Sarah , Kirkendale Lisa , Bieler Rüdiger , Cavanaugh Colleen , Giribet Gonzalo
Published: February 2020

Background Photosymbiotic associations between metazoan hosts and photosynthetic dinoflagellates are crucial to the trophic and structural integrity of many marine ecosystems, including coral reefs. Although extensive efforts have been devoted to study the short-term ecological interactions between coral hosts and their symbionts, long-term evolutionary dynamics of photosymbiosis in many marine animals are not well understood. Within Bivalvia, the second largest class of mollusks, obligate photosymbiosis is found in two marine lineages: the giant clams (subfamily Tridacninae) and the heart cockles (subfamily Fraginae), both in the family Cardiidae. Morphologically, giant clams show relatively conservative shell forms whereas photosymbiotic fragines exhibit a diverse suite of anatomical adaptations including flattened shells, leafy mantle extensions, and lens-like microstructural structures. To date, the phylogenetic relationships between these two subfamilies remain poorly resolved, and it is unclear whether photosymbiosis in cardiids originated once or twice. Results In this study, we establish a backbone phylogeny for Cardiidae utilizing RNASeq-based transcriptomic data from Tridacninae, Fraginae, and other cardiids. A variety of phylogenomic approaches were used to infer the relationship between the two groups. Our analyses found conflicting gene signals and potential rapid divergence among the lineages. Overall, results support a sister group relationship between Tridacninae and Fraginae, which diverged during the Cretaceous. Although a sister group relationship is recovered, ancestral state reconstruction using maximum likelihood-based methods reveals two independent origins of photosymbiosis, one at the base of Tridacninae and the other within a symbiotic Fraginae clade. Conclusions The newly revealed common ancestry between Tridacninae and Fraginae brings a possibility that certain genetic, metabolic, and/or anatomical exadaptation existed in their last common ancestor, which promoted both lineages to independently establish photosymbiosis, possibly in response to the modern expansion of reef habitats.
Heat-Not-Burn Tobacco, Electronic Cigarettes, and Combustible Cigarette Use Among Japanese Adolescents: A Nationwide Population Survey 2017
Authors: Kuwabara Yuki , Kinjo Aya , Fujii Maya , Imamoto Aya , Osaki Yoneatsu , Jike Maki , Otsuka Yuichiro , Itani Osamu , Kaneita Yoshitaka , Minobe Ruriko , Maezato Hitoshi , Higuchi Susumu , Yoshimoto Hisashi , Kanda Hideyuki
Published: February 2020

Background
From among the global public health concerns, smoking remains one of the most crucial challenges. Especially for adolescents, the increase in the use of electronic cigarettes is controversial, as its use may lead to established smoking. In Japan, where a unique tobacco regulation system exists, the heat-not-burn tobacco market has been growing. However, the prevalence and association of combustible cigarettes and new tobacco-related products have not yet been closely investigated among Japanese adolescents. This study aimed to clarify the prevalence of smoking among adolescents, including new types of tobacco-related products, and to compare the characteristics of their users.
Methods
The 2017 Lifestyle Survey of Adolescents is a nationally-representative survey collected in Japan. From the national school directory, 98 junior high schools and 86 high schools were randomly sampled throughout Japan. The students completed an anonymous questionnaire at school. We calculated the prevalence of use for each type of tobacco product. Then, the use of a combination of products and the characteristics of different types of products were examined.
Results
In total, 64,152 students from 48 junior high schools and 55 high schools were included the analysis (school response rate = 56%, M age = 15.7 years, 53.9% boys). The age-adjusted rate of ever (current) use of electronic cigarettes was 2.1% (0.7%) in junior high school and 3.5% (1.0%) in high school; that of combustible cigarettes was 2.6% (0.6%) in junior high school and 5.1% (1.5%) in high school. The rate of heat-not-burn tobacco use was lower relative to other products: 1.1% (0.5%) in junior high school and 2.2% (0.9%) in high school. An examination of the combined use of the three products identified a high number of dual users. Comparisons between different types of users indicated different backgrounds for combustible cigarette users and new product users.
Conclusions
The prevalence of new tobacco-alternative products is growing in popularity among Japanese adolescents. Dual use is common, and many adolescents use new products only. Moreover, e-cigarettes might attract a broader range of groups to smoking. Continuous monitoring and research are needed to investigate their influence as a possible gateway to tobacco smoking.
Dimethyl itaconate inhibits TNF-α induced NF-κB signaling pathway in human epithelial cells
Authors: Zhang Yalei , Deng Xiaobing , Liang Hao , Guo Annan , Li Kenan , Liu Hongbo , Zhang Qi , Lai Luhua
Published: February 2020

Background:
Dimethyl itaconate (DMI), a membrane-permeable derivative of itaconate, was found to moderate IL-17-IκBζ-induced skin pathology including psoriasis in mouse experiments . TNF-α induced NF-κB pathway, which controls a variety of immune and inflammatory responses, was also proven to play a crucial role as mediator in psoriasis. However, whether DMI interacts with the TNF-α induced NF-κB pathway remains unclear.
Results:
Here we show that DMI inhibits TNF-α induced NF-κB transcriptional activities in dose-dependent manner in several human cell lines using dual luciferase assay and blocks the NF-κB nuclear entry. Moreover, DMI potently inhibits IKKβ dependent phosphorylation and degradation of IκBα in TNF-α induced activation of NF-κB pathway. We also demonstrate that DMI covalently binds to cysteine residue in IKKβ, a key regulator in NF-κB pathway, to suppress IKKβ activation and inhibit the canonical NF-κB pathway.
Conclusion
Our study presents a new mechanism for DMI as an anti-inflammatory agent that may have therapeutic potentials in treating NF-κB related human inflammatory diseases. Our results also suggest that itaconate produced by endogenous IRG1 may regulate NF-κB at post translation modification level, and the IRG1-itaconate-NF-κB axis could be targeted as a novel strategy for the treatment of IRG1-NF-κB mediated diseases.
CareConekta: study protocol for a randomized controlled trial of a mobile health intervention to improve engagement in postpartum HIV care in South Africa
Authors: Clouse Kate , Phillips Tamsin K , Camlin Carol , Noholoza Sandisiwe , Mogoba Phepo , Naidoo Julian , Langford Richard , Weiss Martin , Seebregts Christopher J. , Myer Landon
Published: February 2020

Background: South Africa is home to the world’s largest antiretroviral therapy program but sustaining engagement along the HIV care continuum has proven challenging in the country and throughout the wider region. Population mobility is common in South Africa, but important research gaps exist describing this mobility and its impact on engagement in HIV care. Postpartum women and their infants in South Africa are known to be at high risk of dropping out of HIV care after delivery and are frequently mobile.
Methods: In 2017, we developed a beta version of a smartphone application (app) – CareConekta – that detects a user’s smartphone location to allow for prospective characterization of mobility. Now we will adapt and test CareConekta to conduct essential formative work on mobility and evaluate an intervention – the CareConekta app plus text notifications and phone calls and/or WhatsApp messages – to facilitate engagement in HIV care during times of mobility. During the three-year project period, our first objective is to evaluate the feasibility, acceptability, and initial efficacy of using CareConekta as an intervention to improve engagement in HIV care. Our second objective is to characterize mobility among South African women during the peripartum period and its impact on engagement in HIV care. We will enroll 200 eligible pregnant women living with HIV and receiving care at the Gugulethu Midwife Obstetric Unit in Cape Town, South Africa.
Discussion: This work will provide critical information about mobility during the peripartum period and the impact on engagement in HIV care. Simultaneously, we will pilot test an intervention to improve engagement with rigorously-assessed outcomes. If successful, CareConekta offers tremendous potential as a research and service tool that can be adapted and evaluated in multiple geographic regions, study contexts, and patient populations.
Trial registration: ClinicalTrials.gov NCT03836625; registered February 8, 2019.
Tracking Implementation Strategies in the Randomized Rollout of a Veterans Affairs National Opioid Risk Management Initiative
Authors: Rogal Shari S. , Chinman Matthew , Gellad Walid F , Mor Maria K , Zhang Hongwei , McCarthy Sharon A. , Mauro Genna T. , Hale Jennifer A. , Lewis Eleanor T. , Oliva Elizabeth , Trafton Jodie A. , Yakovchenko Vera , Gordon Adam J. , Hausmann Leslie R.M.
Published: February 2020

Background In 2018, the Department of Veterans Affairs (VA) issued Notice 2018-08 requiring facilities to complete ‘case reviews’ for Veterans identified in the Stratification Tool for Opioid Risk Mitigation (STORM) dashboard as high risk for adverse prescription opioid-related outcomes. Half of facilities were randomly assigned to a Notice version including additional oversight. We evaluated implementation strategies used, whether strategies differed by randomization arm, and which strategies were associated with case review completion rates. Methods Facility points of contact completed a survey assessing their facility’s use of 68 implementation strategies based on the Expert Recommendations for Implementing Change taxonomy. We collected respondent demographic information, facility-level characteristics, and case review completion rates (percentage of high-risk patients who received a case review). We used Kruskal-Wallis tests and negative binomial regression to assess strategy use and factors associated with case reviews. Results Contacts at 89 of 140 facilities completed the survey (64%) and reported using a median of 23 (IQR: 16-31) strategies. The median case review completion rate was 71% (IQR: 48%-95%). Neither the number or types of strategies nor completion rates differed by randomization arm. The most common strategies were: using the STORM dashboard (97%); working with local opinion leaders (80%); and recruiting local partners (80%). Characteristics associated with case review completion rates included respondents being < 35 years old (incidence rate ratio, IRR:1.35, 95%CI: 1.09-1.67) and having <5 years in their primary role (IRR:1.23; 95%CI: 1.01-1.51), and facilities having more prior academic detailing around pain and opioid safety (IRR:1.40, 95%CI: 1.12-1.75). Controlling for these characteristics, implementation strategies associated with higher completion rates included: 1) monitoring and adjusting practices (adjusted IRR, (AIRR): 1.40, 95%CI: 1.11-1.77), 2) identifying adaptations while maintaining core components (AIRR: 1.28, 95%CI: 1.03-1.60), 3) conducting initial training (AIRR: 1.16, 95%CI: 1.02-1.50), and 4) regularly sharing lessons learned (AIRR: 1.32, 95%CI: 1.09-1.59). Conclusions In this national evaluation of strategies used to implement case reviews of patients at high risk of opioid-related adverse events, point of contact age and tenure in current role, prior pain-related academic detailing at the facility, and four specific implementation strategies were associated with case review completion rates, while randomization to additional centralized oversight was not.
Is Primary Chemoradiation A Better Treatment? A Retrospective Study of Early Stage Node-positive Cervical Cancer.
Authors: Zhang Nan , Zheng Hong
Published: February 2020

Background.
Cervical cancer is the second most frequently diagnosed cancer and the third leading cause of cancer death for women in developing countries. Radical hysterectomy with bilateral pelvic lymph node dissection is usually preferred for patients of stage IB1-IIA2. Currently, image examinations have certain limitations in diagnose of lymph node metastasis and their detection accuracies are not satisfactory. Only the pathological examination after removal of the suspected metastatic lymph nodes during surgery can conclusively identify the presence of metastasis. If there is a positive result of lymphatic metastasis, there is no clear guideline whether to complete a radical surgery, or to only conduct a systematic lymphadenectomy, followed with adjuvant Concurrent Chemoradiotherapy (CCRT). This retrospective study aimed to compare the efficacy and safety of the two treatment modalities.
Methods.
49 stage IB1-IIA2 cervical cancer patients with lymphatic metastasis confirmed by systemic pelvic and para-aortic lymph node dissection from 2007 to 2018 were reviewed. The patients were treated with either primary chemoradiation or radical hysterectomy followed by adjuvant chemoradiation after lymphadenectomy. Survival states and adverse events of the two treatments were compared.
Results.
Median follow-up time was 45 (range 11-119 months) months. In non-radical surgery group, 1 patient (1/15, 6.7%) relapsed and died, while in radical surgery group, 7 patients (7/27, 25.9%) relapsed and 5 (5/27, 18.5%) died. Significant difference was found in the mean progression-free survival between the two groups, which was 69(95%CI 49.118-88.882) months in non-radical surgery group and 44(95%CI 35.857-52.143) months in radical surgery group (p＜0.01). There was significant difference in three-year progression-free survival(86%vs.71%, p＜0.01). Grade 3-4 toxicity was comparable between the two groups (26.7% vs. 25.9%, p=0.958).
Conclusion.
For stage IB1-IIA2 cervical cancer patients with positive lymph node, primary chemoradiation after pelvic and para-aortic lymphadenectomy seems to have better survival outcomes compared with radical hysterectomy by laparoscopy plus chemoradiation in the retrospective study with limited cases. Evidence from a randomized controlled study is in need to confirm the optimal treatment for early stage node-positive cervical cancer.
Intrinsic Patient Factors Predictive of Inpatient Rehabilitation Facility Discharge Following Primary Total Knee Arthroplasty: A Systematic Review and Meta-Analysis.
Authors: Sattler Larissa Nicole , Hing Wayne Anthony , Rathbone Evelyne , Vertullo Christopher John
Published: February 2020

Background Total Knee Arthroplasty (TKA) reduces pain and improves function in those suffering from severe osteoarthritis. A significant cost of TKA is post-acute care, however, current evidence suggests that discharge to an Inpatient Rehabilitation Facility (IRF) has inferior outcomes to home discharge, with no greater benefit in physical function. Only individual studies have investigated TKA patient characteristics predictive of discharge destination, therefore, the aim is to systematically review the literature and meta-analyse intrinsic patient factors predictive of IRF discharge. If predictive factors are known, then early discharge planning and intervention strategies could be implemented. Methods Databases PubMed, CINAHL, Embase, Cochrane, and Pedro were searched up to October 2019 for articles investigating pre-operative intrinsic patient factors predictive of IRF discharge. For assessing the methodological quality of included studies, the Quality In Prognosis Studies (QUIPS) tool was used. Statistical analysis and graphical reporting were conducted in R statistical software. To assess the effect of predictors of discharge destination, odds ratios with the corresponding 95%CI were extracted from the results of univariate and multivariable analyses. Results A total of 9 articles published between 2011 to 2018 with 218,151 TKA patients were included. Of the 13 intrinsic patient factors reported, 6 met the criteria for synthesised review: age, obesity, comorbidity, gender, SF-12/VR-12 survey, and smoking. Due to the heterogeneity of statistical analysis and reporting 2 variables could undergo meta-analysis, gender and smoking. Female gender increased the likelihood of IRF discharge by 1.78 (OR=1.78; 95%CI=1.43–2.20; I2=33.3%), however, the relationship between smoking status and discharge destination was less certain (OR=0.80; 95%CI=0.42–1.50; I2=68.5%). Conclusion Female gender was shown to be predictive of IRF discharge after total knee arthroplasty. There was also a trend for those of older age, increased comorbidity or the severely obese to have an increased likelihood of IRF discharge. This systematic review and meta-analysis suggests that the heterogeneity of existing literature is inadequate to develop a predictive model for intrinsic patient factors associated with IRF discharge. Further, high quality studies of prospective design on predictive factors are warranted, to enable early discharge planning and optimise resource consumption on post-acute care following TKA.
Temporal Dynamics of the Human Microbiome
Authors: Kenney Toby , Gao Junqiu , Gu Hong
Published: February 2020

Background There has been a lot of research about the role of the microbiome in various processes. The research has focused almost exclusively on the structure of the microbiome at a single time-point. There have been several studies that measure the microbiome from a particular environment over time. However, even in these studies, little has been done to study the temporal dynamics of the microbiome. In this paper, we begin to rectify this situation. We analyse a widely studied microbial data set that contains a time series of the microbiome from four body sites on two healthy individuals. We choose a data set based on healthy individuals because we are interested in the baseline temporal dynamics of the microbiome. Results For this analysis, we focus on the temporal dynamics of individual genera, ignoring the interactions. We use simple stochastic differential equation models to assess the following three questions. (1) Does the microbiome exhibit temporal continuity? (2) Does the microbiome have a stable state? (3) To better understand the temporal dynamics, how frequently should data be sampled in future studies? We find that a simple Ornstein-Uhlenbeck model which incorporates both temporal continuity and reversion to a stable state fits the data for all genera better than a Brownian motion model that contains only temporal continuity. The Ornstein-Uhlenbeck model also fits the data better than modelling separate time points as independent. Under the Ornstein-Uhlenbeck model, we calculate the variance of the estimated mean reversion rate (the speed with which each genus returns to its stable state). Based on this calculation, we are able to determine the optimal sample schemes for studying temporal dynamics. Conclusions There is evidence of temporal continuity for at least some genera; there is clear evidence of a stable state; and the optimal sampling frequency for studying temporal dynamics is in the range of one sample every 0.8–3.2 days.