bluuebunny/crossref_metadata_2025 huggingface dataset:
Data-Driven Characterization of Shale Reservoirs Towards Facilitation of Production Performance Evaluation
Authors: Salahshoor Shadi
Published: April 2021

Leveraging publicly available data is a crucial stepfor decision making around investing in the development of any new unconventional asset.Published reports of production performance along with accurate petrophysical and geological characterization of the areashelp operators to evaluate the economics and risk profiles of the new opportunities. A data-driven workflow can facilitate this process and make it less biased by enabling the agnostic analysis of the data as the first step.

In this work, several machine learning algorithms are briefly explained and compared in terms of their application in the development of a production evaluation tool for a targetreservoir. Random forest, selected after evaluating several models, is deployed as a predictive model thatincorporates geological characterization and petrophysical data along with production metricsinto the production performance assessment workflow. Considering the influence of the completion design parameters on the well production performance, this workflow also facilitates evaluation of several completion strategies toimprove decision making around the best-performing completion size.

Data used in this study include petrophysical parameters collected from publicly available core data, completion and production metrics, and the geological characteristics of theNiobrara formation in the Powder River Basin. Historical periodic production data are used as indicators of the productivity in a certain area in the data-driven model. This model, after training and evaluation, is deployed to predict the productivity of non-producing regions within the area of interest to help with selecting the most prolific sections for drilling the future wells. Tornado plots are provided to demonstrate the key performance driversin each focused area.

A supervised fuzzy clustering model is also utilized to automate the rock quality analyses for identifying the "sweet spots" in a reservoir. The output of this model is a sweet-spot map that is generated through evaluating multiple reservoir rock properties spatially. This map assists with combining all different reservoir rock properties into a single exhibition that indicates the average "reservoir quality"of the formation in different areas.

Niobrara shale is used as a case study in this work to demonstrate how the proposed workflow is applied on a selected reservoir formation whit enough historical production data available.
Novel Application to Recognize a Breakdown Pressure Event on Time Series Frac Data Vs. an Artificial Intelligence Approach
Authors: Ramirez Alberto Jose , Iriarte Jessica Graciela
Published: April 2021

Breakdown pressure is the peak pressure attained when fluid is injected into a borehole until fracturing occurs. Hydraulic fracturing operations are conducted above the breakdown pressure, at which the rock formation fractures and allows fluids to flow inside. This value is essential to obtain formation stress measurements. The objective of this study is to automate the selection of breakdown pressure flags on time series fracture data using a novel algorithm in lieu of an artificial neural network.

This study is based on high-frequency treatment data collected from a cloud-based software. The comma separated (.csv) files include treating pressure (TP), slurry rate (SR), and bottomhole proppant concentration (BHPC) with defined start and end time flags. Using feature engineering, the model calculates the rate of change of treating pressure (dtp_1st) slurry rate (dsr_1st), and bottomhole proppant concentration (dbhpc_1st). An algorithm isolates the initial area of the treatment plot before proppant reaches the perforations, the slurry rate is constant, and the pressure increases. The first approach uses a neural network trained with 872 stages to isolate the breakdown pressure area. The expert rule-based approach finds the highest pressure spikes where SR is constant. Then, a refining function finds the maximum treating pressure value and returns its job time as the predicted breakdown pressure flag.

Due to the complexity of unconventional reservoirs, the treatment plots may show pressure changes while the slurry rate is constant multiple times during the same stage. The diverse behavior of the breakdown pressure inhibits an artificial neural network's ability to find one "consistent pattern" across the stage. The multiple patterns found through the stage makes it difficult to select an area to find the breakdown pressure value. Testing this complex model worked moderately well, but it made the computational time too high for deployment. On the other hand, the automation algorithm uses rules to find the breakdown pressure value with its location within the stage.

The breakdown flag model was validated with 102 stages and tested with 775 stages, returning the location and values corresponding to the highest pressure point. Results show that 86% of the predicted breakdown pressures are within 65 psi of manually picked values.

Breakdown pressure recognition automation is important because it saves time and allows engineers to focus on analytical tasks instead of repetitive data-structuring tasks. Automating this process brings consistency to the data across service providers and basins. In some cases, due to its ability to zoom-in, the algorithm recognized breakdown pressures with higher accuracy than subject matter experts. Comparing the results from two different approaches allowed us to conclude that similar or better results with lower running times can be achieved without using complex algorithms.
The State of the Art in Monitoring and Surveillance Technologies for IOR, EOR and CCUS Projects
Authors: Al-Qasim Abdulaziz S. , Kokal Sunil L. , Al-Ghamdi Muataz S.
Published: April 2021

Monitoring and surveillance (M&S) is one of the key requisites for assessing the effectiveness and success of any Improved Oil Recovery (IOR) or Enhanced Oil Recovery (EOR) project. These projects can include waterflooding, gas flooding, chemical injection, or any other types. It will help understand, track, monitor and predict the injectant plume migration, flow paths, and breakthrough times. The M&S helps in quantifying the performance of the IOR/EOR project objectives. It provides a good understanding of the remaining oil saturation (ROS) and its distribution in the reservoir during and after the flood.

A comprehensive and advanced monitoring and surveillance (M&S) program has to be developed for any given IOR/EOR project. The best practices of any such M&S program should include conventional, advanced and emerging novel technologies for wellbore and inter-well measurements. These include advanced time-lapse pulsed neutron, resistivity, diffusion logs, and bore-hole gravity measurements, cross-well geophysical measurements, water and gas tracers, geochemical, compositional and soil gas analyses, and 4D seismic and surface gravity measurements.

The data obtained from the M&S program provide a better understanding of the reservoir dynamics and can be used to refine the reservoir simulation model and fine tune its parameters. This presentation reviews some proven best practices and draw examples from on-going projects and related novel technologies being deployed. We will then look at the new horizon for advanced M&S technologies.
State of the Art in Characterization of Frac Stage Geometry and Conductivity Using Pressure Leakoff
Authors: Ibrahim Mohamed Mohamed , Ozkan Erdal
Published: April 2021

Pressure-transient analysis (PTA) is widely used in the industry to estimate fracture half-length, height, and skin due to hydraulic fracturing as well as reservoir parameters. PTA studies focus on pressure data from long shut-in periods and diagnostic fracture injection tests (DFITs), while analyzing the pressure data recorded during the hydraulic fracture treatment has been overlooked. This paper details the state-of-the-art in applying pressure transient analysis to better estimate hydraulic fracture conductivity and dimensions and improve treatment designs stage by stage.

The initial portion of this paper describes the application of a novel and low-cost diagnostic method for post-fracture analysis. The bulk of the paper is dedicated to present case histories that illustrate the PTA of the recorded pressure data during treatment to obtain estimates of fracture dimensions and conductivity. The pressure recorded during each stage is processed to ensure the proper data quality and the pressure falloff at the end of the stage is filtered out. The pressure is then analyzed for multi-cluster, finite-conductivity fractures, to obtain the fracture half-length, conductivity, and leakoff.

Calculated parameters from each stage are compared to provide insights into the hydraulic fracture design and confirm the adequacy of the treatment design along the well. The results from stage leakoff pressure analysis are very valuable in confirming relative fracture conductivity and providing a qualitative measure of fracture length and height. The total stimulated reservoir area (SRA) calculated using the proposed method yields comparable values to SRA obtained from buildup analysis. The information provided is as valuable and comparable as that from direct near-wellbore diagnostics, such as radioactive traces, temperature logging, real-time micro-seismic monitoring, and production logging.

The paper proposes a novel, low-cost analytical PTA method for estimating fracture dimensions, skin, and leakoff coefficient. We illustrate – with several field cases – that conventional post-fracture techniques can be integrated with the stage by stage PTA analysis to provide not only a more consistent and systematic analysis but also a more accurate assessment of treatment effectiveness. The findings of this paper help improve the efficiency of multistage hydraulic fracturing stimulation of horizontal wells.
Adsorption of Anionic Surfactants in Sandstones: Impact of Sacrificial Agents
Authors: Koparal Gulcan Bahar , Sharma Himanshu , Liyanage Pathma J. , Panthi Krishna K. , Mohanty Kishore
Published: April 2021

High surfactant adsorption remains a bottleneck for a field-wide implementation of surfactant floods. Although alkali addition lowers surfactant adsorption, alkali also introduces many complexities. In our systematic study, we investigated a simple and cost effective method to lower surfactant adsorption in sandstones without adding unnecessary complexities. Static and dynamic surfactant adsorption studies were conducted to understand the role of sacrificial agent sodium polyacrylate (NaPA) on adsorption of anionic surfactants n outcrop and resevoir sandstone corefloods. The dynamic retention studies were conducted with and without the presence of crude oil. Surfactant phase behavior studies were first conducted to identify surfactant blends that showed ultralow interfacial tension (IFT) with two crude oils at reservoir temperature (40°C). Base case dynamic retention data, in the absence of crude oil, was obtained for these surfactant formulations at their respective optimum salinities. NaPA was then added to these surfactant formulations and similar adsorption tests were conducted. Finally, oil recovery SP corefloods were conducted for each surfactant formulations, with and without adding NaPA, and oil recovery data including the surfactant retention was compared.

Static adsorption of these surfactant formulations at their respective optimum salinities on crushed sandstone varied from 0.42-0.74 mg/g-rock. Their respective adsorptions lowered to 0.37-0.49 mg/g-rock on adding a small amount of NaPA. Surfactant retention in single-phase dynamic SP corefloods in the absence of crude oil in outcrop Berea cores was between 0.17 to 0.23 mg/g-rock. On adding a small amount of NaPA, the surfactant adsorption values lowered to 0.1 mg/g-rock. Oil recovery SP corefloods showed high oil recovery (~91% ROIP) and low surfactant retention (~0.1 mg/g-rock) on adding NaPA to the surfactant formulations.
Application and Exploration of Early In-Situ Combustion Huff-and-Puff Technology in a Deep Undisturbed Reservoir with Extra Heavy Oil
Authors: Xiaoyan Wang , Jian Zhao , Qingguo Yin , Bao Cao , Yang Zhang , Fengxiang Zhao , Lidong Zhang , Haiying Cheng , Xi Yan , Song He
Published: April 2021

Achieving effective results using conventional thermal recovery technology is challenging in the deep undisturbed reservoir with extra-heavy oil in the LKQ oil field. Therefore, in this study, a novel approach based on in-situ combustion huff-and-puff technology is proposed. Through physical and numerical simulations of the reservoir, the oil recovery mechanism and key injection and production parameters of early-stage ultraheavy oil were investigated, and a series of key engineering supporting technologies were developed that were confirmed to be feasible via a pilot test. The results revealed that the ultraheavy oil in the LKQ oil field could achieve oxidation combustion under a high ignition temperature of greater than 450°C, where in-situ cracking and upgrading could occur, leading to greatly decreased viscosity of ultraheavy oil and significantly improved mobility. Moreover, it could achieve higher extra-heavy-oil production combined with the energy supplement of flue gas injection. The reasonable cycles of in-situ combustion huff and puff were five cycles, with the first cycle of gas injection of 300 000 m3 and the gas injection volume per cycle increasing in turn. It was predicted that the incremental oil production of a single well would be 500 t in one cycle. In addition, the supporting technologies were developed, such as a coiled-tubing electric ignition system, an integrated temperature and pressure monitoring system in coiled tubing, anticorrosion cementing and completion technology with high-temperature and high-pressure thermal recovery, and anticorrosion injection-production integrated lifting technology. The proposed method was applied to a pilot test in the YS3 well in the LKQ oil field. The high-pressure ignition was achieved in the 2200-m-deep well using the coiled-tubing electric igniter. The maximum temperature tolerance of the integrated monitoring system in coiled tubing reached up to 1200°C, which provided the functions of distributed temperature and multipoint pressure measurement in the entire wellbore. The combination of 13Cr-P110 casing and titanium alloy tubing effectively reduced the high-temperature and high-pressure oxygen corrosion of the wellbore. The successful field test of the comprehensive supporting engineering technologies presents a new approach for effective production in deep extra-heavy-oil reservoirs.
FOUR score versus GCS in patients with traumatic brain injury in the prehospital setting
Authors: Furman Matej Rubelli , Gorenjak Mario , Ravnik Janez
Published: April 2021

Background: In the last few decades, different coma scoring scales have been proposed. The purpose of this study is to compare two coma scales, the GCS (Glasgow Coma Scale) and the FOUR score (Full Outline of UnResponsiveness score), aiming to examine which scale is better for predicting outcome in traumatic brain injury (TBI) patients in the prehospital setting.Methods: We evaluated the GCS and FOUR scores in the prehospital setting at three different prehospital timepoints, and we reassessed the scores in surviving patients 24 hours, one month and three months after the injury. Then, we compared the outcomes.We used the χ² method, and based on the analysis with the best cut-off point for each model, we calculated the sensitivity, specificity and correct prediction of outcomes with four severity scores. The Youden index, Z score, McNemar's test and ROC curve were also assessed. P < 0.05 was considered statistically significant. Both scales were ranked with gain ratios.Results: We included 200 TBI patients who were treated in a prehospital setting by a prehospital specialized medical unit. In terms of the predictions of positive outcomes, our study showed the following:1. Twenty-four hours after the injury, the best cut-off points obtained were from the FOUR 1 and GCS 1 models.2. One month after the injury, the best cut-off points obtained were from the following models: FOUR 2 and GCS 3 as well as FOUR 3 and GCS 3.3. Three months after the injury, the best cut-off points obtained were from the following models: FOUR 2 and GCS 1, FOUR 3 and GCS 1, and GCS 1 and GCS 2.Conclusions: In our study, the results of our research confirm that there are no practical or clinical differences between the GCS and FOUR scores in terms of predicting morality outcomes 24 hours, one month, and three months after injury. No statistically significant differences were found in the Youden index or the area under the ROC curve 24 hours, one month or three months after the injury.
KIF15 Accelerated The Progression of Nasopharyngeal Carcinoma and Predict Poor Prognosis
Authors: Wang Yongli , Yang Yong , Qin Ying , Liu Fei , Shu Jingcheng , Li Bing , Huang Guangwu , Qu Shenhong
Published: April 2021

Background: Nasopharyngeal carcinoma (NPC) is a common tumor in head and neck and is prevailing in China. Although treatment methods continue to improve, the prognosis of advanced patients is still unsatisfactory. Kinesin family member 15 (KIF15) is a kind of protein, which regulates the process of cell mitosis and plays an important role in several types of human cancers. This study aims to investigate the role of KIF15 in NPC.Methods: First, the differential expression of KIF15 in NPC and para-carcinoma tissues was evaluated based on both data collected from Gene Expression Omnibus (GEO) database and immunohistochemical analysis on clinical specimens collected from in-house cohort. Next, cell lines C666-1 and CNE-2Z were selected for the construction of KIF15‑knockdown cell models. Then, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, wound healing, Transwell and clone formation assays were used to detect the proliferation, apoptosis, migration, invasion and colony formation of nasopharyngeal carcinoma cells in vitro. A mouse xenograft model was constructed for in vivo study. Furthermore, Human Apoptosis Antibody Array kit was used to screen possible targets of KIF15 in NPC. In the end, the potential molecular mechanisms underlying the effects of KIF15 was explored through western blot analysis.Results: The results showed that the expression of KIF15 in NPC tissues is higher than that in para-carcinoma tissues, and high levels of KIF15 expression are associated with low survival rates. In addition, knockdown of KIF15 inhibited cell proliferation, migration, invasion and colony formation ability, and promoted cell apoptosis. What’s more, in vivo xenograft experiments showed that down-regulation of KIF15 can inhibit NPC tumor growth. Moreover, the mechanism study demonstrated a variety of apoptosis-related proteins as well as PI3K/AKT and MAPK signaling pathways may be involved in KIF15-induced regulation of NPC.Conclusions: In short, we demonstrated that KIF15 is overexpressed and accelerated the progression of nasopharyngeal carcinoma. It can be used as a new prognostic indicator as well as a potential drug target for the treatment of NPC.
Process Monitoring in a Flexible Manufacturing Cell through Data Analytics and a Visualisation Tool
Authors: Arellano Giovanna Martinez , Nguyen ThuBa , Hinton Chris , Ratchev Svetan
Published: April 2021

With the need of more responsive and resilient manufacturing processes for high value, customised products, Flexible Manufacturing Systems (FMS) remain a very relevant manufacturing approach. Due to their complexity, quality monitoring in these types of systems can be very difficult, particularly in those scenarios where the monitoring cannot be fully automated due to functional, safety and legal characteristics. In these scenarios, quality practitioners concentrate on monitoring the most critical processes and leaving out the inspection of those that are still meeting quality requirements but showing signs of future failure. In this paper we introduce a methodology and visualisation tool based on data analytics that allows the practitioner to anticipate out of control processes and take action. By identifying a reference model or best performing machine, and the occurring patterns in the quality data, the presented approach identifies the adjustable processes that are still in control, allowing the practitioner to decide if any changes in the machine's settings are needed (tool replacement, repositioning the axis, etc). An initial deployment of the tool at BMW Plant Hams Hall to monitor a focussed set of part types and features has shown a reduction in scrap of 97% throughout 2020 in relation to the monitored features compared to the previous year. This in the long run will reduce reaction time in following quality control procedure, reduce significant scrap costs and ultimately reduce the need for measurements and enable more output in terms of volume capacity.
Preparation and characterization of a novel polysialic acid/gelatin composite hydrogels cross-linked by Tannic acid to improve healing and nursing care of cesarean section dressing
Authors: Zhang Yan , Wang Chunjie , Wang Lijing , Hou Li
Published: April 2021

The infections and delayed wound healing after cesarean delivery is one of the most complicated issues in surgical medicinal field. In the present investigation, designed novel polysialic acid loaded gelatin (PSA-Gel) composite hydrogels cross-linked by tannic acid (TA) has been developed and used as a facile wound dressing to improve cesarean wound healing ability with prevent bactericidal infections. The cross-linking effect was predominant when the TA content was lower, resulting in the formation of a cross-linked network. An effective TA cross-linking effect on the PSA-Gel hydrogel matrix was achieved when the amount of TA was around 15 wt %. The morphology of as-fabricated hydrogels was characterized using scanning electron microscopy (SEM) with an average pore sizes of PSA-Gel, PSA-Gel-TA-5%, PSA-Gel-TA-10%, and PSA-Gel-TA-15% hydrogels were 95.4 ± 12.6 µm, 120.4 ± 8.2 µm, 165.3 ± 21.6 µm, and 270.2 ± 32.5 µm, respectively. The effects of hydrogels on the swelling ratio, in vitro degradation, and mechanical properties were systemically evaluated. The TA cross-linked PSA-Gel hydrogels display strong antimicrobial behavior against gram-positive (Staphylococcus aureus) gram-negative (Escherichia coli) bacteria strains. Moreover, PSA-Gel-TA hydrogels also displayed favorable cytotoxicity toward L929 fibroblast cell lines. Finally, the therapeutic and wound healing potential of the PSA-Gel-TA hydrogels has been studied in vivo using the excision wound model in rats. The results indicate that the PSA-Gel-TA hydrogels have a greater and significant effect on wound closure and increased the wound healing rate compared with native PSA-Gel hydrogels and untreated control group. The findings suggest that PSA-Gel-TA hydrogels are promising dressing materials for the treatment of wound healing.
Design of Master-slave velocity tracking Upper-limb Exoskeleton system and Feed-forward compensation control
Authors: Kong Dezhi , Wang Wendong , Shi Yikai
Published: April 2021

In this paper, we propose a design approach of mirror driving master-slave upper limb exoskeleton based on inertia measurement unit (IMU) system and ZigBee wireless network transmission system. By integrating two gyroscopes on the master side, we can conduct measurement of rotation velocity and acceleration signal and control over a larger range of motion (ROM) of the exoskeleton. The angular velocity information is transmitted to the controller on the paretic side through ZigBee wireless module. Applying the Lagrangian dynamic equation and Geometric projection method, the 3-axes angular velocity are converted into the reference angular velocity control signal of four joint motors of the rehabilitation upper limb exoskeleton. Moreover, a novel control scheme based on inertia moment and gravity moment feed-forward compensation is proposed. The simulation results demonstrate that the controller can enhance the performance according to the responding speed and stability. Experimental results show that the designed scheme of the mirror driving master-slave upper limb exoskeleton system is completely feasible and realizable.
Advanced Arc Plasma Synthesis of Biomorphic Silicon Carbide Using Charcoal and Silicon Dioxide in Air
Authors: Pak Alexander Ya , Larionov Kirill B , Korchagina Anastasia P , Yakich Tamara Yu. , Yankovsky Stanislav A , Gubin Vladimir E , Slyusarskiy Konstantin V , Gromov Alexander A
Published: April 2021

The paper presents the results of experimental studies on the advanced synthesis method for a cubic phase of silicon carbide using charcoal and silicon dioxide as precursors. The charcoal used for the synthesis was obtained by steam pyrolysis of wood wastes (sawdust). It was found that the arc synthesis could be executed in air due to the protective CO and CO2 environment formation by charcoal oxidation. With an increase of the amount of supplied energy by direct current arc plasma synthesis, the products of two crystalline phases were formed: graphite and cubic phase of silicon carbide. The phase of silicon carbide was extracted from the synthesis product by its annealing in air at 850 °C. The resulting cubic SiC phase was characterized by an elementary cell parameter of 4.359 Å. According to the data of scanning electron microscopy, the morphology of crystals obtained is common for the biomorphic silicon carbide which was identified in the synthesis product. The ceramics synthesized by spark plasma sintering from the obtained material was characterized by a density of ~2.0 g/cm3.
Peer-led Theoretically Desinged HIV/AIDS Prevention Intervention Among Students: A Case Of Health Belief Model
Authors: Joorbonyan Hoda , Mohtasham Ghaffari , Sakineh Rakhshanderou
Published: April 2021

Background & Aim: HIV/AIDS is one of the most dangerous viruses known in the world. In addition, considering its fatality rate and high cost of care, it is a serious threat to the health and economy of social communities. Adolescents are one of the high-risk groups. One of the most effective ways to prevent this disease is to promote healthcare, raise awareness, and change health-related beliefs and attitudes. This study aims at determining the effect of peer education, based on the health belief model, on the preventative measures against AIDS adopted by girls. Methods & Materials: In this empirical-interventionist study two schools were randomly selected, one of which was considered as the intervention group and the other as the control group. The classes were also randomly selected and 80 students from each school took part in the project following the entry criterion. A questionnaire with acceptable validity and reliability was used to collect data. In this study a few bright students were chosen as peer educators after being trained. The intervention group received 4 sessions of 60-minute education through training, lectures, question and answer, and group discussion. The posttest was administered two months after the treatment. The data was fed into the SPSS 16. Finally, T-test, Chi-Square, and ANCOVA were employed to analyze the data. 2 Results: The average scores obtained from the intervention group and the control group were not significantly different in terms of awareness level, perceived susceptibility, perceived severity, perceived benefits, perceived barriers, perceived self-efficacy, behavioral intention, and pre-intervention behavior (P˃0.05). Two months after the intervention there was a significant increase in the average scores of all the variables in the experimental group (P>0.05). However, there was no significant change in the scores of the control group (P>0.05). Conclusion: Following a health belief model focusing on peer eduaction among high school girls, the intervention eduaction can affect awareness level, susceptibility, severity, benefits, perceived barriers, perceived self-efficacy, behavioral intention, and finally avoidance of high-risk behavior.
Effect of short-time irrigation with industrial poultry wastewater on young olive tree (Olea europaea L. cv. Chemlali) growth parameters and the chemical composition of leaves
Authors: Oueslati Amira , Montevecchi Giuseppe , Antonelli Andrea , Mansour Hedi Ben
Published: April 2021

The purpose of this study was to evaluate the short-term irrigation effect with industrial poultry wastewater on young olive trees (Olea europaea L. cv. Chemlali). Industrial poultry wastewater can be considered as a bio-fertilizer due to its richness in nutritive elements (SO42−, HCO3−, total nitrogen and K+). The physico-chemical analysis of wastewater showed a high concentration of TSS, COD, BOD, COT, NO3−, and conductivity. Measurements indicated that poultry wastewater enhanced plant growth, leaves dry matter, and ashes in comparison with tap water, as well as poultry wastewater diluted with tap water, however, a decrease in total soluble sugars (glucose and fructose) was detected in leaves. The determination of fatty acid profile of young olive trees leaves irrigated with poultry wastewater showed richness on saturated fatty acids in comparison with mono- and poly-unsaturated ones. In addition, oleic acid (C18:1) presented the lowest content in leaves of trees irrigated with poultry wastewater irrigation. According to those results, poultry wastewater lends itself to being a hydric alternative and at the same time a source of nutrients that can help fill the water deficit in semi-arid countries and avoid costly waste disposal for slaughterhouses.
Tau AD fragment aggregates proliferate through autocatalytic secondary nucleation
Authors: Camargo Diana Rodriguez , Sileikis Eimantas , Chia Sean , Axell Emil , Bernfur Katja , Cataldi Rodrigo , Cohen Samuel , Meisl Georg , Habchi Johnny , Knowles Tuomas , Vendruscolo Michele , Linse Sara
Published: April 2021

The self-assembly of the protein tau into neurofibrillary tangles is one of the hallmarks of Alzheimer’s disease and related tauopathies. Still, the molecular mechanism of tau aggregation is largely unknown. This problem may be addressed by systematically obtaining reproducible in vitro kinetic measurements under quiescent conditions in the absence of triggering substances. Here, we implement this strategy by developing protocols for obtaining an ultra-pure tau fragment (residues 304-380 of tau441, tau AD fragment) and for performing spontaneous aggregation assays with reproducible kinetics under quiescent conditions. We are thus able to identify the mechanism of fibril formation of the tau AD fragment at physiological pH using fluorescence spectroscopy and mass spectrometry. We find that primary nucleation is slow, and that secondary processes dominate the aggregation process once the initial aggregates are formed. Moreover, our results further show that secondary nucleation of monomers on fibril surfaces dominate over fragmentation of fibrils. Using separate isotopes in monomers and fibrils, through mass spectroscopy measurements, we verify the isotope composition of the intermediate oligomeric species, which reveals that these small aggregates are generated from monomer through secondary nucleation. Our results provide a framework for understanding the processes leading to tau aggregation in disease, and for selecting possible tau forms as targets in the development of therapeutic interventions in Alzheimer’s disease.
Improved Naive Bayes Classification Algorithm for Traffic Risk Management
Authors: Hua Rui , hu songhua , Chen Hong , Zhao Xiuju
Published: April 2021

Naive Bayesian classification algorithm is widely used in big data analysis and other fields because of its simple and fast algorithm structure. Aiming at the shortcomings of naive Bayes classification algorithm, this paper uses feature weighting and Laplace calibration to improve it, and obtains the improved naive Bayes classification algorithm. Through numerical simulation, it is found that when the sample size is large, the accuracy of the improved naive Bayes classification algorithm is more than 99%, and it is very stable; when the sample attribute is less than 400 and the number of categories is less than 24, the accuracy of the improved naive Bayes classification algorithm is more than 95%. Through empirical research, it is found that the improved naive Bayes classification algorithm can greatly improve the correct rate of discrimination analysis from 49.5% to 92%. Through robustness analysis, the improved naive Bayes classification algorithm has higher accuracy.
Effects of Cell Aging on Proteomics and Post-translational Modifications of UMSCs
Authors: Wang Junyan , Zhao Keli , Chen Junhui , Chen Ling , Zhou Jinyu , Sun Qing , Li Yan
Published: April 2021

BackgroundMesenchymal stem cells (MSCs) are thought to be critical for successful regenerative medicine and immunosuppressive therapy. However, long term culturing of MSCs is known to impair cellular function and induces aging of MSCs.MethodsTo investigate the cellular mechanisms involved in the aging of MSC cultures, we analyzed human umbilical cord mesenchymal stem cells (hUMSCs) exposed to different culture conditions (glucose concentrations were 5.5 mM/25 mM/40mM) for 7/30 days using tandem mass tag (TMT) labeling quantitative proteomics, analyzing posttranslational protein modifications and applying bioinformatics methods. Differentially expressed proteins (DEPs) were clustered and functional annotated by Gene Ontology (GO) enrichment analysis. Pathway enrichment analysis was performed based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotation tool. To identify the changes in N-glycans properties during culturing of hMSCs for either 7 or 30 days under three different glucose concentration, we analyzed the mesenchymal stem cell glycome using a mass spectrometry-based N-glycan profiling method.ResultsHere, we found that the morphology of hUMSCs during a long-term culturing period changed significantly compared with 7 days conditions. More specifically, we fund that a total of 66 proteins (fold change >1.50 and P-value <0.05 as criteria) were differentially expressed in long term culture hUMSCs, with 49 proteins upregulated and 17 proteins downregulated. Our GO analysis showed that aging exerts a side effect onUMSCs by affecting variable molecular functions and biological processes, such as lysosome organization, exopeptidase activity, hydrolase activity, glycosaminoglycan binding and post-translational protein modification. KEGG analysis demonstrated that differential abundance proteins were significantly enriched in lysosomes, renin-angiotensin system, other glycan degradation and autophagy. The results of glycosylation analysis showed that cell N-glycans is associated with aging.ConclusionIn conclusion, our comprehensive analysis revealed that the difference in differentially expressed proteins and post-translational protein modification levels between aging group vs control, which could provide a possible basis for aging and cell quality control study.
Adsorbent Minimisation for Removal of Ibuprofen from Water in a Two-Stage Batch Process
Authors: Farzaneh Hajar , Saththasivam Jayaprakash , McKay Gordon , Parthasarathy Prakash
Published: April 2021

Pharmaceutical products in water, frequently referred to as personal pharmaceutical products, PCPPs are regarded as problematic emerging pollutants with the potential to cause damaging health and environmental impacts to several ecosystems. In this study, an acid activated carbon has been produced from waste date stones, the waste product obtained from the seedless date products manufacturing industry. This material has been used to remove the pharmaceutical compound ibuprofen from water with a high adsorption capacity of 126 mg ibuprofen per g waste date stone derived activated carbon. In order to optimise the use of the activated carbon, a design study has been performed to minimise the quantity of carbon needed using a two-stage batch adsorption system. Several variables have been inputted into the design model to test the model and compare the quantities of adsorbent required in the two-stage and the single stage systems under various conditions.
Why trees sleep? - explanations to diurnal branch movement
Authors: Junttila Samuli , Hölttä Teemu , Lindfors Lauri , Issaoui Aimad El , Vastaranta Mikko , Hyyppä Hannu , Puttonen Eetu
Published: April 2021

Physiological processes cause movements of tree stems and branches that follow a circadian rhythm, but there is a lack of quantitative understanding of the cause-and-effect relationships. We investigated the diurnal movement of tree branches using time-series of terrestrial laser scanning measurements coupled with measurements of environmental drivers and tree water status. Our results showed that diurnal movement of branches was largely explained by leaf water status. This conclusion was supported by the significantly lower overnight branch movement in leaf-off than leaf-on conditions. Our findings conclude that alteration in leaf water status causes systematic branch movements following a diurnal rhythm. Due to lower atmospheric water demand during the nighttime, tree branches settle down analogously to sleep as the amount of water in leaves is increasing. The results indicate that quantified movement of tree branches could help us to further monitor and understand the water relations of tree communities.
Referral Patterns To Pediatric Pulmonology For Asthma-Like Symptoms
Authors: Prynn Tory A. , Garland Gretchen , Mirea Lucia , Drewek Rupali
Published: April 2021

Background: The decision to refer a sick child to a pediatric specialist is important for health care quality, however access to specialty care is worsening. Referrals from primary to specialty care are a critical first step in coordinating specialty care, but there are often shortcomings in the appropriateness, clarity, and completeness of referrals. This study aimed to characterize referrals for asthma-like symptoms to a pediatric pulmonology clinic, evaluate consult interventions, and identify opportunities for improving access. Methods: A retrospective chart review examined patients ages 5-18 years, referred to the pulmonology clinic at Phoenix Children’s Hospital between July 2016 and July 2019. Descriptive statistics summarized demographics, prior asthma diagnosis, ICS use and compliance, reason for referral and intervention during consult. An appropriate referral was defined as prior asthma and ICS Step 3. Results: The total 171 study subjects had mean (standard deviation) age of 9.4 (3.8) years, with 100 (58%) males, and prior asthma diagnosis in 105 (61%). The most common reason for pulmonology referral was asthma in 90 (53%) patients, of which 70 (78% of 90) had prior asthma. Among 105 patients with asthma, 79 (76%) had a history of ICS, with 33 (42% of 79) patients reporting spacer compliance issues. The rate of appropriate referrals was 0.11 (95% confidence interval: 0.06-0.16). During the pulmonology consult, nearly half 10 (53%) of 19 patients appropriately referred received an ICS step up. Among 151 inappropriate referrals, ICS was initiated for 91 (60%) and increased for 45 (30%). Education was provided to all patients during pulmonology consult. Conclusions: Mild-to-moderate asthma can be effectively treated by primary care providers (PCPs) with implementation of ICS, thus prioritizing healthcare resource utilization by enabling the pulmonologist to see higher acuity patients sooner. Further study is warranted to identify strategies and tools for PCPs to optimize asthma management.
Pulmonary Sequestration With Fungus Infection Presenting as Highly Elevated Carcinoembryonic Antigen
Authors: luo Wei , Hu Tong-chen , luo lincheng , Li Ya-lun
Published: April 2021

Background: Pulmonary sequestration (PS) associated with massive hemoptysis, hemothorax, and elevated tumor markers or even diagnosed with lung malignancy has been reported many times. But all these clinical features have never been reported in the patient diagnosed with PS without malignant disease.Case presentation: A 45-year-old man with PS presented with massive hemoptysis, hemothorax, extremely elevated carcinoembryonic antigen (CEA) in the pleural effusion, was initially misdiagnosed with advanced lung carcinoma, and was finally diagnosed with PS with Aspergillus infection.Conclusions: PS is rarely concurrent with lung cancer; most of the time, it is easily misdiagnosed as a malignancy, especially when presenting with a fungal infection, which could remarkably elevate CEA in the pleural effusion.
Identification of genetic sequence variations associated with the pathogenesis of X-linked hyper-IgM syndrome
Authors: Wang Wang , Ding Jun-Li , Zhu Yu-Lin , Huo Shao-Hu , Fang Lu-Lu , Jin Teng-Chuan , Shen Bing , Ding Sheng-Gang
Published: April 2021

Background: X-Linked Hyper-IgM Syndrome (X-HIGM) is a rare genetic primary immunodeficiency disease caused by mutations of the CD40 ligand gene (CD40LG). It is characterized by normal or elevated levels of IgM and markedly decreased serum IgG, IgA, and IgE levels. Patients with this syndrome are often prone to infections. Environmental and genetic (especially genetic mutation) factors may play an important role in etiology, development, and pathogenesis of X-HIGM. Methods: DNA from a male child diagnosed as having X-HIGM and DNA from his healthy mother were used for whole-exome (next-generation) sequencing and targeted gene sequencing. The results were analyzed using Exome Aggregation Consortium data and the Genome Aggregation Database and were further validated using Sanger sequencing. Results: Next-generation sequencing results indicated that the CD40LG gene in the child had a p.R203I variant. In addition, his mother was a carrier, suggesting that the child’s p.R203I homozygous mutation was inherited from his mother. The functional prediction scores from SIFT, MetaSVM, and FATHMM software indicated that this genetic variant may be harmful. Conclusions: Single variations in many exons of the CD40LG gene can lead to X-HIGM. Although the pathogenicity of the variant identified in the present study has not been previously reported, prediction software found that it would be harmful. Thus, CD40LG may be related to this genetic disease. Despite these limitations, our findings provided insight into X-HIGM pathogenesis and suggested a potential target for therapeutic drug development.
Applying Hybrid Equal Channel Angular Pressing (HECAP) to pure copper using optimized Exp.-ECAP die
Authors: Öğüt Serkan , Kaya Hasan , Kentli Aykut , UÇAR Mehmet
Published: April 2021

Equal channel angular pressing (ECAP), expansion equal channel angular pressing (Exp.-ECAP) and hybrid equal channel angular pressing (HECAP) processes were applied to pure copper specimens within this study. Before the ECAP and HECAP processes, an Exp.-ECAP mold with optimum geometric parameters was produced to be used in these processes. The samples, on which ECAP, Exp.-ECAP and HECAP processes were applied, were subjected to microstructure analysis and mechanical tests, and the effects of these processes were examined. The results obtained showed that the Exp.-ECAP process gave better results in grain refinement and mechanical properties, and the Exp.-ECAP passes applied after the ECAP process within the scope of the HECAP process provided a more homogeneous distribution for grain size and hardness.
The importance of comorbidity in the presence of low culture positivity in a education and research hospital in Istanbul
Authors: Filik Armagan , Gungel Hulya , OGREDEN Tulin
Published: April 2021

The authors have requested that this preprint be removed from Research Square.
Combination of gene set signatures correlates with response to nivolumab in platinum-resistant ovarian cancer
Authors: Murakami Ryusuke , Hamanishi Junzo , Brown J. B. , Abiko Kaoru , Yamanoi Koji , Taki Mana , Hosoe Yuko , Yamaguchi Ken , Baba Tsukasa , Matsumura Noriomi , Konishi Ikuo , Mandai Masaki
Published: April 2021

Background Based on our previous phase II clinical trial of anti-programmed death-1 (PD-1) antibody nivolumab for platinum-resistant ovarian cancer (n=19, UMIN000005714), we aimed to identify the therapeutic response biomarkers to nivolumab in ovarian cancer. Methods Tumor gene expressions were evaluated by proliferative, mesenchymal, differentiated, and immunoreactive gene signatures derived from high-grade serous carcinomas in The Cancer Genome Atlas and a signature established prior to ovarian clear cell carcinoma. Gene sets were scored using the single-sample gene set enrichment analysis, and resulting scores were used to assess the correlation between each gene set and the clinical response to nivolumab therapy. Statistical analyses were performed to identify pathways differentially expressed by either the complete response (CR) or progressive disease (PD) groups. Results The clear cell gene signature significantly had higher score in the CR group, and the proliferative gene signature had significantly higher score in the PD group where nivolumab was not effective (respective p-values 0.005 and 0.026). Combinations of gene signatures improved correlation with response, where a projection of immunoreactive, proliferative, and clear cell signatures differentiated clinical response. Conclusion Ovarian cancer-specific gene signature and related pathway scores provide a preliminary indicator for ovarian cancer prior to receiving anti-PD-1 antibody therapy.
Influence of Natural Climate Variability on Extreme Wave Power over Indo-Pacific Ocean Assessed using ERA5
Authors: Kumar Prashant , Kaur Sukhwinder , Weller Evan , Young Ian R.
Published: April 2021

In recent decades, wave power (WP) energy from the ocean is one of the cleanest renewable energy sources associated with oceanic warming. In Indo-Pacific Ocean, the WP is significantly influenced by natural climate variabilities, such as El Niño Southern Oscillation (ENSO), Indian Ocean Dipole (IOD) and Pacific Decadal Oscillation (PDO). In this study, the impact of major climate variability modes on seasonal extreme WP is examined over the period 1979–2019 using ERA5 reanalysis data and the non-stationary generalized extreme value analysis is applied to estimate the climatic extremes. Independent ENSO influence after removing the IOD trends (ENSO|IOD) on WP are evident over the eastern and central Pacific during December–February (DJF) and March–May (MAM), respectively, which subsequently shifts towards the western Pacific in June–August (JJA) and September–November (SON). The ENSO|PDO impact on WP exhibits similar yet weaker intensity year round compared to ENSO. Extreme WP responses due to the IOD|ENSO include widespread decreases over the tropical and eastern Indian Ocean (IO), with localized increases only over the South China and Philippine (SCP) seas and Bay of Bengal (BOB) during JJA, and the Arabian Sea during SON. Lastly, for the PDO|ENSO, the significant increases in WP are mostly confined to the Pacific, and most prominent in the North Pacific. Composite analysis of different phase combinations of PDO (IOD) with El Niño (La Niña) reveals stronger (weaker) influences year-round. The response patterns in significant wave height (SWH), peak wave period (PWP), sea surface temperatures (SST), and sea level pressure (SLP) helps to explain the seasonal variations in WP.